General concepts in meteorology and dynamics

The aim of this chapter is to give a general overview of the atmospheric circulation, highlighting the main concepts that are important for a basic understanding of meteorology and atmospheric dynamics relevant to atmospheric data assimilation.

Nitrogen fertilizer and seed rate effects on Hagberg failing number of hybrid wheats and their parents are associated with alpha-amylase activity, grain cavity size and dormancy

Field experiments were carried out to assess the effects of nitrogen fertilization and seed rate on the Hagberg falling number (HFN) of commercial wheat hybrids and their parents. Applying nitrogen (200 kg N ha(-1)) increased HFN in two successive years. The HFN of the hybrid Hyno Esta was lower than either of its parents (Estica and Audace), particularly when nitrogen was not applied. Treatment effects on HFN were negatively associated with a-amylase activity. Phadebas grain blotting suggested two populations of grains with different types of a-amylase activity: Estica appeared to have a high proportion of grains with low levels of late maturity endosperm a-amylase activity (LMEA); Audace had a few grains showing high levels of germination amylase; and the hybrid, Hyno Esta, combined the sources from both parents to show heterosis for a-amylase activity. Applying nitrogen reduced both apparent LMEA and germination amylase. The effects on LMEA were associated with the size and disruption of the grain cavity, which was greater in Hyno Esta and Estica and in zero-nitrogen treatments. External grain morphology failed to explain much of the variation in LMEA and cavity size, but there was a close negative correlation between cavity size and protein content. Applying nitrogen increased post-harvest dormancy of the grain. Dormancy was greatest in Estica and least in Audace. It is proposed that effects of seed rate, genotype and nitrogen fertilizer on HFN are mediated through factors affecting the size and disruption of the grain cavity and therefore LMEA, and through factors affecting dormancy and therefore germination amylase. (c) 2004 Society of Chemical Industry.

Decision-making in a phase II clinical trial: a new approach combining Bayesian and frequentist concepts

The aim of a phase H clinical trial is to decide whether or not to develop an experimental therapy further through phase III clinical evaluation. In this paper, we present a Bayesian approach to the phase H trial, although we assume that subsequent phase III clinical trials will hat,e standard frequentist analyses. The decision whether to conduct the phase III trial is based on the posterior predictive probability of a significant result being obtained. This fusion of Bayesian and frequentist techniques accepts the current paradigm for expressing objective evidence of therapeutic value, while optimizing the form of the phase II investigation that leads to it. By using prior information, we can assess whether a phase II study is needed at all, and how much or what sort of evidence is required. The proposed approach is illustrated by the design of a phase II clinical trial of a multi-drug resistance modulator used in combination with standard chemotherapy in the treatment of metastatic breast cancer. Copyright (c) 2005 John Wiley & Sons, Ltd.

Infection of hybrid primula seeds by Botrytis cinerea and latent disease spread through the plants

Botrytis cinerea occurred commonly on cultivated Primula ×polyantha seed. The fungus was mostly on the outside of the seed but sometimes was present within the seed. The fungus frequently caused disease at maturity in plants grown from the seed, demonstrated by growing plants in a filtered airflow, isolated from other possible sources of infection. Young, commercially produced P. ×polyantha plants frequently had symptomless B. cinerea infections spread throughout the plants for up to 3 months, with symptoms appearing only at flowering. Single genetic individuals of B. cinerea, as determined by DNA fingerprinting, often were dispersed widely throughout an apparently healthy plant. Plants could, however, contain more than one isolate.

Poly[(2,2 '-bipyridine-kappa N-2,N ')-(mu(2)-dihydrogen phosphato-kappa O-2 : O ')-(mu(2)-hydrogen phosphato-kappa O-2 : O ')-aluminium(III)], Al(2,2 '/bipy)-(HPO4)(H2PO4), a layered inorganic - organic hybrid material

The title compound, [Al(HPO4)(H2PO4)(C10H8N2)]n, consists of AlO4N2 octahedra vertex-linked to H2PO4 and HPO4 tetrahedra to form layers based on a (4,12)- net. The layers stack in an AAA fashion, held in place by pi-pi interactions between 2,2 '-bipyridine molecules coordinated to Al atoms in adjacent layers.

Solution self-assembly of hybrid block copolymers containing poly(ethylene glycol) and amphiphilic beta-strand peptide sequences

The self-assembly in aqueous solution of hybrid block copolymers consisting of amphiphilic β-strand peptide sequences flanked by one or two PEG chains was investigated by means of circular dichroism spectroscopy, small-angle X-ray scattering, and transmission electron microscopy. In comparison with the native peptide sequence, it was found that the peptide secondary structure was stabilized against pH variation in the di-and tri-block copolymers with PEG. Small-angle X-ray scattering indicated the presence of fibrillar structures, the dimensions of which are comparable to the estimated width of a β-strand (with terminal PEG chains in the case of the copolymers). Transmission electron microscopy on selectively stained and dried specimens shows directly the presence of fibrils. It is proposed that these fibrils result from the hierarchical self-assembly of peptide β-strands into helical tapes, which then stack into fibrils.

Pervaporation dehydration of isopropyl alcohol with NaY zeolite incorvorated hybrid membranes

With a solution technique, NaY zeolite incorporated, tetraethylorthosilicate-crosslinked poly(vinyl alcohol) membranes were prepared. The resulting membranes were tested for their ability to separate isopropyl alcohol/water mixtures by pervaporation in the temperature range of 30-50 degrees C. The effects of the zeolite content and feed composition on the pervaporation performance of the membranes were investigated. The experimental results demonstrated that both flux and selectivity increased simultaneously with increasing zeolite content in the membranes. This was explained on the basis of the enhancement of hydrophilicity, selective adsorption, and establishment of a molecular sieving action attributed to the creation of pores in the membrane matrix. The membrane containing 15 mass % zeolite exhibited the highest separation selectivity of 3991 with a flux of 5.39 X 10(-2) kg/m(2) h with 10 mass % water in the feed at 30 degrees C. The total flux and flux of water were close to each other for almost all the studied membranes, and this suggested that the membranes could be used effectively to break the azeotropic point of water/isopropyl alcohol mixtures to remove a small amount of water from isopropyl alcohol. From the temperature-dependent diffusion and permeation values, the Arrhenius activation parameters were estimated. The activation energy values obtained for water were significantly lower than those for isopropyl alcohol, and this suggested that the developed membranes had a higher separation efficiency for water/isopropyl alcohol systems. The activation energy values for total permeation and water permeation were found to be almost the same for all the membranes, and this signified that coupled transport was minimal because of the highly selective nature of the membranes. Positive heat of sorption values were observed in all the membranes, and this suggested that Henry's mode of sorption was predominant. (c) 2008 Wiley Periodicals, lnc.