bluuebunny/crossref_metadata_2025 huggingface dataset:
A fragmentation study of podophyllotoxin and its 4′‐demethyl‐4β‐substituted derivatives by electrospray ionization ion‐trap time‐of‐flight tandem mass spectrometry
Authors: Li Qianrong , Yan Guoquan , Ge Tiefei
Published: July 2007

High‐resolution electrospray ionization multistage tandem mass spectrometry (MS1–9) was used to determine the accurate masses and the fragmentation pathways of protonated podophyllotoxin (1) and its corresponding 4′‐demethyl‐4β‐substituted derivatives (2–4). The protonated molecules, [M + H]+, of all the four compounds were observed in the conventional single‐stage mass spectra. Two fragmentation pathways, that appear to be characteristic of the four compounds, are proposed on the basis of their multistage tandem mass spectrometric data. The characteristic elimination, from the precursor protonated ions, of the neutral groups 4‐R1H, 1‐ArH, CO, CH2O and C4H4O2, in which R is located on C‐4, is the common elimination, and the product ions at m/z 267, 239, 229, 181, 173, 153, 143 and 115 are the common diagnostic masses. The elimination of the R1 group substituent located on the C‐4 position of compounds 1–4 has a significant influence on the fragmentation pathway obtained in the conventional single‐stage mass spectra. A large R1 group would be unfavorable for this elimination, unless the collision energy is raised. Apart from the common fragmentations obtained for the protonated molecules 1–4, significant additional product ions were detected in the various multistage tandem mass spectrometric analyses, particularly in the case of the product ions derived initially from the phenolic hydroxyl group of 2–4, which are different from those of 1. Based on these additional formed product ions, several additional fragmentation pathways for 1 or 2–4 are also presented. Copyright © 2007 John Wiley & Sons, Ltd.
Variation of GaAs surface charge under an electron beam: effect on cathodoluminescence signal
Authors: Nouiri A. , Elateche Z. , Aouati R. , Belabed N.
Published: July 2007

This work is a self‐consistent calculation model of the GaAs surface charge under electronic bombardment. The surface charge due to surface defects can be influenced by the electron–hole pair generated at the surface zone (in the depletion region). Numerical results show that the donor states charge decreases under the cathodic excitation, but when the surface states are of acceptor type, the surface charge increases with increasing excitation levels (increasing of beam current). In the case of donor states, the cathodoluminescence (CL) intensity increases when the energy level Et, associated with the surface density Nt, is near the conduction band Ec. In the case of acceptor states, the same behavior of CL intensity has been observed when Et is near the valance band Ev. In all cases, the CL intensity decreases when Et moves to the middle of the band gap. According to this calculation, it is clear that the variation of surface charge must be taken into account in all surface analysis techniques based on electron beams. Copyright © 2007 John Wiley & Sons, Ltd.
Development of drift design model for high‐rise buildings subjected to lateral and vertical loads
Authors: Park Hyo Seon , Seo Ji Hyun , Kwon Yun Han
Published: July 2007

Recent developments of resizing algorithms based on displacement participation factor have had a significant impact on drift design of high‐rise buildings. However, most drift design methods based on resizing algorithms have considered only lateral load and overlooked the effect of the vertical load in the calculation of member displacement participation factors. Therefore, in this paper, the practical drift design method of high‐rise buildings is presented in the form of a resizing algorithm by developing product integral modules required for the calculation of displacement participation factors with the consideration of both lateral and vertical loads. The effect of vertical load on the drift design model based on member displacement participation factors is investigated in detail using the verifying example of a 20‐story building structure. The drift design method in combination with the strength design module is then applied to the drift design of a 60‐story high‐rise building structure. Copyright © 2007 John Wiley & Sons, Ltd.
Seismic response of semi‐active friction‐damped reinforced concrete structures with self‐variable stiffness
Authors: Iskhakov I. , Ribakov Y.
Published: July 2007

The influence of structural self‐variable stiffness and semi‐active friction dampers on the behavior of reinforced concrete (RC) buildings during strong earthquakes is discussed. A fully braced six‐story beamless RC frame is analyzed. The effect of concrete braces (with only constructive reinforcement) as a self‐variable mechanism is studied. It is shown that up to a certain limit the frame itself controls its behavior by adapting its dynamic characteristics in the real time of the earthquake. This self‐adaptation is achieved by autonomous disengagement of the braces under tension and their further nonlinear action under compression. The system has several levels of seismic adaptation, and it selects one of them for enhanced response to the given earthquake. However, when the limit is reached, further self‐adaptation of the frame becomes impossible. The occurrence of an earthquake of higher magnitude can then lead to disengagement of the concrete braces under compression, intensifying structural damage and even causing collapse. The use of semi‐active controlled friction dampers is proposed as a means of preventing the collapse of braces under compression, thereby enabling structures to withstand earthquakes. The forces in the friction dampers are regulated according to an optimal control algorithm. Modulation of the friction level in real time during the earthquake yields additional improvement of structural seismic behavior and obviates the need for retrofitting. Copyright © 2007 John Wiley & Sons, Ltd.
Computation of story drifts considering panel zone deformations for multistory steel moment frames with welded flange plate connections
Authors: Hsiao J. Kent , Schultz William , Petersen Troy , Vaicik Stephen
Published: July 2007

The 2003 International Building Code (IBC) requires that the contribution of panel zone deformations to overall story drifts be included in the mathematical model of the physical steel moment‐resisting frame systems. A finite‐element model can accurately take the panel zone deformations into consideration for the computation of story drifts, yet the preparation of the model is usually very time consuming. A line‐element model significantly simplifies the frame analysis, yet it cannot address the issue of panel zone deformations. These two types of models are statistically evaluated in this paper for steel moment frames with welded flange plate (WFP) connections. A total of 16 beam–column combinations are evaluated for each type of model. The elastic story drift of each beam–column combination is then obtained from each type of model. Finally, adjustment factors are developed to correct the story drifts that are computed using the line‐element models for the frames with WFP connections. Copyright © 2007 John Wiley & Sons, Ltd.
Drift design model for high‐rise buildings based on resizing algorithm with a weight control factor
Authors: Seo Ji Hyun , Song Weon‐Keun , Kwon Yun Han , Hong Kappyo , Park Hyo Seon
Published: July 2007

It is well known that the weight of the structural system for a high‐rise building to resist lateral loads increases in nonlinear fashion with increase in building height and slenderness ratio. For a given building height or slenderness ratio, the weight of the structural system for a high‐rise building subjected to lateral loads depends on the degree of stiffness of the building structure. Therefore, at the final stage of the structural design process, it has been a challenge to structural engineers to improve the efficiency of a structural system by either minimizing the weight of a structure for a given limit on lateral displacement or maximizing the degree of stiffness for a given weight of a structure. In this paper, a resizing design method that can minimize the magnitudes of lateral displacement and inter‐story drift of a high‐rise building with respect to structural weights is presented. Based on the proposed design method, the relation between the structural weight and the magnitude of lateral displacement is investigated using two examples, including a 60‐story high‐rise building. Copyright © 2007 John Wiley & Sons, Ltd.
Slit‐connected coupling beams for tunnel‐form building structures
Authors: Yuksel S. Bahadir
Published: July 2007

Openings to provide functional use in shear walls of tunnel‐form buildings result in coupled shear walls and coupling beams. These beams are deep compared to their clear span above the door openings; however, their thickness is less than 250mm. Moreover, they are subjected to high shear forces under lateral loads. Dimensional constraints make their design against high shear forces difficult when code‐specified reinforcement configurations are applied. In this paper, slits at each end of coupling beams are proposed to decrease the shear stiffness and shear forces of these deep coupling beams. The structural behavior of coupled shear walls with slit‐connected coupling beams (SCCBs) is investigated by performing two‐dimensional static and dynamic analyses. Stiffness terms of SCCBs are obtained as a result of extensive finite element simulations. Based on the parametric study conducted, an equivalent prismatic beam model representing SCCBs is proposed. Thereby, coupled shear walls having SCCBs can be analyzed by the equivalent frame method using the equivalent prismatic beam model. Copyright © 2007 John Wiley & Sons, Ltd.
Integrated aerodynamic load determination and stiffness design optimization of tall buildings
Authors: Chan C. M. , Chui J. K. L. , Huang M. F.
Published: July 2007

Modern tall steel buildings are wind sensitive and are prone to dynamic serviceability problems. Although wind tunnel techniques have emerged as valuable tools in providing reliable prediction of the wind‐induced loads and effects on tall buildings, current design practice normally considers the wind tunnel‐derived loads as constant static design loads. Such practice does not take into account the change in wind‐induced structural loads while the dynamic properties of a building are modified during the design synthesis process. This paper presents a computer‐based technique that couples together an aerodynamic wind tunnel load analysis routine and an element stiffness optimization method to minimize the cost of tall steel buildings subject to the lateral drift design criteria, while allowing for instantaneous prediction and updating of wind loads during the design synthesis process. Results of a full‐scale steel building framework with the same geometric shape of the Commonwealth Advisory Aeronautical Research Council (CAARC) standard building indicate that not only is the proposed technique able to produce the cost‐effective element stiffness distribution of the structure satisfying the serviceability wind drift design criteria, but a potential benefit of reducing the design wind loads can also be achieved by the stiffness optimization method. Copyright © 2007 John Wiley & Sons, Ltd.
Characterization of osteoporotic bone structures by bidimensional images through x‐ray microfluorescence with synchrotron radiation
Authors: Lima Inayá , Anjos Marcelino J. , Fleiuss Maria Lucia F. , Rosenthal Doris , Lopes Ricardo T.
Published: July 2007

The objective of this study was to characterize the bone structures of the femoral head and the cortical and trabecular regions, using two‐dimensional images produced by x‐ray microfluorescence, which supplies information about the superficial distribution of minerals. The measurements were performed in the standard geometry with 45 incidence, and excitation with a white beam and an optical capillary with 20 µm diameter collimation in the x‐ray fluorescence (XRF) beam line at the Synchrotron Light National Laboratory (Campinas, Brazil). The results show that both the concentration and the distribution of the minerals vary significantly among the groups, mostly in relation to the element calcium, depending on the location and bone site. Copyright © 2007 John Wiley & Sons, Ltd.
Phenotypic variation in fruit and seed characteristics of buffalo gourd
Authors: Scheerens J. C. , Bemis W. P. , Dreher M. L. , Berry J. W.
Published: July 2007

Eighty‐five accessions of Buffalo gourd,Cucurbita foetidissima HBK., were assayed for variation in seven fruit and seed characteristics: fruit diameter (−x = 65 mm); seed weight per 100 seeds (−x = 3.8 g); seed weight per fruit (−x = 8.4 g); seed number per fruit (−x = 225); percentage embryo in seed (−x = 67.3%); percent crude fat of whole seed (−x = 32.9%); and percent crude protein of defatted embryo (−x = 69.5%). The variation in amino acid distribution (12) accessions) and in oil composition (15 accessions) was obtained. Relationships among traits were explored. Agronomic improvement through breeding was also discussed.
Reactions of lipids in corn with ammonia
Authors: Black L. T. , Spencer G. F. , Brekke O. L.
Published: July 2007

Ammonia has recently been employed in experimental tests for the treatment of corn to inactivate aflatoxin, to control molds, and as a preservative during ambient‐air drying of freshly harvested high‐moisture corn. When these various ammonia treatments are properly applied, no adverse effects have been found on any of the constituents of whole corn. However, in the work being reported when 0.1% or more ammonia was in contact with corn in the presence of air for more than a few days, irreversible changes occurred in the polyunsaturated lipids that were proportionate to the ammonia concentrations. The extent of the changes were dependent upon: (a) air‐to‐corn ratio, (b) ammonia concentration, (c) temperature, (d) corn moisture, and (e) time. The changes were characterized by a reduction in unsaturation of the lipid, by incorporation of nitrogen into the lipids, and by a consequent increase in lipid polarity. The change in polarity of these altered lipids rendered them unextractable with the usual fat solvents. Air (oxygen) and an initiating mechanism that occurs naturally in corn were required for the lipid‐ammonia interaction to occur. This interaction involved only the polyunsaturated fatty acid moieties and formed a class of nitrogenous derivatives. Corn may be treated with ammonia for purposes of detoxification or preservation for long periods with no detectable adverse effects on the lipid composition, as long as headspace air is kept low during ammoniation. This may be accomplished in any of the following ways: (a) by ammonia ting the corn with a very limited headspace, (b) by ammoniating corn in a sealed bin and displacing the air in the headspace with ammonia gas, and (c) by replacing the headspace air with an inexpensive, inert gas such as nitrogen.
An investigation of the basic conditions for tocopherol determination in vegetable oils and fats by differential pulse polarography
Authors: Podlaha O. , Eriksson Å. , Toregård B.
Published: July 2007

The polarographic behavior of α‐, γ‐, and δ‐tocopherols was studied according to the proposed official IUPAC method for tocopherol determination in vegetable oils and fats. Each of the tocopherols had a different polarographic response; however, the tocotrienols had the same half‐wave potentials and probably also the same polarographic response as the corresponding tocopherols. Additives previously investigated plus several others were examined for possible interference. The results by polarography and a new high performance liquid chromatography (HPLC) method were compared. The analysis by t‐test at 99% significance level showed no differences for the determinations of α‐tocopherol, but the results for three of the γ‐tocopherol results were less consistent under the same conditions. The results for the determination of δ‐tocopherol were below the detection limit for polarography and could not be statistically evaluated. The polarographic method investigated was found to be uncomplicated and therefore suitable for routine work. However, when using the method, one has to take into account possible interference by additives and the limitations due to the lack of separation of β‐ from γ‐tocopherol and/or the interference of tocotrienols with the corresponding tocopherol peaks. From this aspect the HPLC method gives better resolution.
Preparation and selective hydrolysis of acetal esters
Authors: Adlof R. O. , Neff W. E. , Emken E. A. , Pryde E. H.
Published: July 2007

Abstract and Summary

Medium chain length aldehydic acids and esters (C8‐C13) were synthesized by ozonolysis of readily available cyclic and straight chain alkenoate esters followed by rearrangement or reduction of the ozonide. The acetal esters, prepared by reaction of the aldehydic acids with CH3OH‐HC1, were characterized by gas liquid chromatography, proton magnetic resonance, carbon magnetic resonance, thin layer chromatography, and infrared analysis. Selective hydrolysis of the acetal esters to aldehyde esters was conveniently accomplished with H2O‐HC1‐CH3CN to give 95% or higher yields in less than 30 min. Development of this simple and effective hydrolysis procedure allows these medium chain length esters to be safely stored as their acetal esters, which retards their oxidation, trimerization, and decomposition.
Measurement of emulsion stability by pulsed nuclear magnetic resonance (NMR)
Authors: Trumbetas J. F. , Fioriti J. A. , Sims R. J.
Published: July 2007

Abstract and Summary

The stability of emulsions can be measured rapidly and accurately using pulsed nuclear magnetic resonance (NMR).
Specific gravities of rapeseed and canbra oils
Authors: Ackman R. G. , Eaton C. A.
Published: July 2007

Abstract and Summary

New varieties of rapeseed oils grown in Canada have bess than 1% erucic (cis‐13‐docosenoic) acid and also a reduction in cis‐11‐eicosenoic acid. The replacement of these acids with C18 acids increased the specific gravity (25 C/25 C) from 0.9123 for an oil with 23.1% erucic acid to 0.9171 for an oil with 0.7% erucic acid. Soybean oil data are presented for comparison.
A quality control procedure for the gas liquid chromatographic evaluation of the flavor quality of vegetable oils
Authors: Waltking Arthur E. , Zmachinski Helen
Published: July 2007

Abstract and Summary

An objective procedure which is relatively simple and rapid is under study for the determination of the flavor quality of vegetable oils. This procedure utilizes the direct injection of an oil sample to which has been added an internal standard, into a packed precolumn of a gas Chromatograph. The volatiles are swept from the precolumn through a 10% SE‐30 column under operating parameters which permit complete elution of all volatiles and internal standard within 20 min. Some 1 5 to 20 samples can be evaluated in one day before it is necessary to replace any part of the foot‐long precolumn. Evaluations have been made by the gas liquid Chromatographic (GLC) procedure and by a flavor panel of oil samples subjected to a variety of storage conditions. Generally, differences in the GLC pattern are reflected in the flavor panel results.
Lipid‐Derived flavors of legume protein products
Authors: Sessa David J. , Rackis Joseph J.
Published: July 2007

Abstract and Summary

Legumes contain unsaturated lipids that are susceptible to oxidative deterioration. Enzymic and non‐enzymic deterioration of these lipids results in the development of off‐flavors. The primary objective of this review is to summarize what is currently known about lipid‐derived flavors of soybeans and underblanched pea seeds(Pisum sativum). Identifying the numerous volatile compounds arising from breakdown of lipid hydroperoxides coupled with organoleptic evaluation defines the flavor problem. Major contributors to the green‐beaniness of soybeans were found to be 3‐cis‐hexenal, 2‐pentyl furan, and ethyl vinyl ketone. Oxidized phosphatidylchohnes cause some of the bitter taste. The interaction of lipid breakdown products with proteins, carbohydrates, and other constituents can affect flavor characteristics and also increase the problems of their removal from soy protein products. To prepare bland products, it will be necessary to develop processes that effectively remove bound flavor components and prevent formation of derived flavors. Solvent systems based on alcohol have been used to extract flavor principles from soybeans; aqueous alcohol treatment of the intact seed or blanching with hot water or steam inhibits formation of off‐flavors in peas and soybeans. A new approach involving infusion of antioxidants into the intact seed to control lipid deterioration during processing and storage is proposed to minimize flavor formation without subsequent undesirable changes in protein which occur with alcohol treatments.
Application of tracer techniques to studies on autoxidation reactions
Authors: Khan N. A.
Published: July 2007

The tracers containing deuterium, carbon isotopes, and heavy oxygen that may be applied to the studies on autoxidation reactions are described. The autoxidation of the deuterated compounds formed by replacing hydrogen atoms on the double bond has given concrete experimental evidence for the following phenomena of autoxidation reaction: a) initial attack of oxygen at the double bond and the inherent induction period, b) the propagation of autoxidation by attack on the methylenic group, alpha to the double bond during the steady state, c) the presence of resonance in the free radicals formed and consequent shifting of the double bond, and d) the location of the hydrogen atoms contributing to the formation of the major portion of the water.

These investigations have led to the elucidation of some aspects of the mechanism of decomposition of peroxides and consequent formation of hydroxyl radicals, which attack the substrates at certain preferential points giving rise to water. They also provide the mechanisms of cleavage and formation of the volatile products.

Our experiments have also established four different and distinct stages of autoxidation. Water formation in autoxidation is shown to be the outcome of the primary decomposition of peroxides, mainly hydroperoxides, and the formation of the organic volatile products to be that of the secondary decomposition at a later stage. These processes have been correlated to the bond strengths of the different atoms in the substrates and the resulting products. The advantages and disadvantages of the application of these tracer techniques to autoxidation reactions in general are also discussed.
The glyceride structure of natural fats. I. A technique for the quantitative determination of glyceride types in natural fats
Authors: Kartha A. R. S.
Published: July 2007

The acetone‐permanganate oxidation method for determination of GS3 has been shown to be unreliable because some hydrolysis of the azelaoglycerides occurs, the products of which are determined as GS3. The presence of excess acetic acid throughout the oxidation corrects this defect. GS2A can be precipitated quantitatively as the magnesium salt. Although it is contaminated with GSA2, its proportion can be calculated and from this the proportion of GS2U in the sample can be found.

The remainder of the precipitate is GSA2; its weight, when added to that found in the filtrates, gives the total GSA2. From this, the percentage of GSU2 in the sample can be derived. The GS3 is determined separately, and the content of GU3 can be estimated by difference.
Pancreatic and Duodenal Invasion in Distal Bile Duct Cancer: Paradox in the Tumor Classification of the American Joint Committee on Cancer
Authors: Ebata Tomoki , Nagino Masato , Nishio Hideki , Igami Tsuyoshi , Yokoyama Yukihiro , Nimura Yuji
Published: July 2007

Background

Distal bile duct cancer often invades the pancreas and/or duodenum. Invasion of the pancreas is defined as a T3 and that of the duodenum as a T4 tumor in the T classification of the American Joint Committee on Cancer (AJCC). The aim of this study was to assess whether this T classification is rational from the viewpoint of prognostic power.

Method

Ninety‐five patients with distal bile duct cancer were retrospectively analyzed according to the current T classification of the AJCC.

Results

The main determinant of pT3 (n = 32) and pT4 (n = 30) was pancreatic and duodenal invasion, respectively, and the survival rates for patients with pT3 and pT4 are similar (p = 0.595). Duodenal invasion was present in 39% of the patients with pancreatic invasion, whereas pancreatic invasion was observed in 86% of those with duodenal invasion. The survival for patients with pancreatic invasion was not significantly different (p = 0.283) whether or not there was concomitant duodenal invasion (n = 19 and n = 37, respectively). Multivariate analysis identified venous invasion, distant metastasis, histologic grade, and pancreatic invasion as independent prognostic factors.

Conclusion

Although duodenal invasion usually occurs after pancreatic invasion, it is not a significant prognostic factor while pancreatic invasion is. The current T classification should be revised since it expresses tumor extension but does not reflect a survival in distal bile duct cancer.
Degeneracy in Candecomp/Parafac and Indscal Explained For Several Three-Sliced Arrays With A Two-Valued Typical Rank
Authors: Stegeman Alwin
Published: July 2007

The Candecomp/Parafac (CP) method decomposes a three-way array into a prespecified number R of rank-1 arrays, by minimizing the sum of squares of the residual array. The practical use of CP is sometimes complicated by the occurrence of so-called degenerate sequences of solutions, in which several rank-1 arrays become highly correlated in all three modes and some elements of the rank-1 arrays become arbitrarily large. We consider the real-valued CP decomposition of all known three-sliced arrays, i.e., of size p× q × 3, with a two-valued typical rank. These are the 5 × 3 × 3 and 8 × 4 × 3 arrays, and the 3 × 3 × 4 and 3 × 3 × 5 arrays with symmetric 3 × 3 slices. In the latter two cases, CP is equivalent to the Indscal model. For a typical rank of {m, m+1}, we consider the CP decomposition with R=m of an array of rank m+1. We show that (in most cases) the CP objective function does not have a minimum but an infimum. Moreover, any sequence of feasible CP solutions in which the objective value approaches the infimum will become degenerate. We use the tools developed in Stegeman (2006), who considers p × p × 2 arrays, and present a framework of analysis which is of use to the future study of CP degeneracy related to a two-valued typical rank. Moreover, our examples show that CP uniqueness is not necessary for degenerate solutions to occur.
Physical Therapy and Complementary and Alternative Medicine: An Educational Tool for Enhancing Integration
Authors: Kearney Gina , Cioppa-Mosca JeMe , Peterson Margaret G. E. , MacKenzie C. Ronald
Published: July 2007

In an outpatient rehabilitation setting, both patients’ use and therapists’ knowledge of complementary and alternative medicine (CAM) varies widely. Based on this observation and a recognition of CAM as an emerging practice area for rehabilitation professionals, it was felt that a thorough and consistent approach to the education and orientation of physical therapists to the world of CAM and integrative care was needed. This special interest paper will describe one center's approach, development, and use of a unique and comprehensive training manual designed to provide both a structured and standardized approach for educating physical therapists about CAM and related therapeutic modalities. This innovative teaching tool allows for multiple methods of content delivery within a multidisciplinary format and can be used for those who practice currently or desire to practice in an integrative care environment.
Clinical relevance of short‐term day‐time breathing disorders in chronic heart failure patients
Authors: La Rovere Maria Teresa , Pinna Gian Domenico , Maestri Roberto , Robbi Elena , Mortara Andrea , Fanfulla Francesco , Febo Oreste , Sleight Peter
Published: July 2007

Background:

Periodic Breathing (PB, waxing and waning of tidal volume in which hyperventilation alternates with periods of apnoea or hypopnoea), is common during sleep and wakefulness in patients with Heart Failure (HF) and may increase mortality.

Aim:

To assess the effect of short‐term, day‐time PB on prognosis, in HF patients.

Methods:

We prospectively studied 380 consecutive HF referrals who had a 10 min, supine day‐time respiratory recording. We related PB (adjusted for known predictors) to total cardiac mortality, during a median follow‐up of 41 months.

Results:

Day‐time PB occurred in 145/380 patients who had more severe HF and more compromised left ventricular function (p<0.005). Survival curves began to separate after 10 months and diverged steadily over the next 4 years with a cumulative risk of 41% (PB) vs 26% (No‐PB), p<0.002. PB was independently predictive of increased cardiac mortality when entered into a clinical prognostic model (including NYHA Class, LVEF, LVEDD, Systolic Arterial Pressure, beta‐blocker treatment, peak VO2 and blood urea) with a RR: 1.8, 95% CI 1.20–2.81.

Conclusion:

In advanced HF the presence of PB during a short day‐time recording adds to known predictors of cardiac mortality. This may have practical implications for trials of HF therapy.
An arachidonic acid generation/export system involved in the regulation of cholesterol transport in mitochondria of steroidogenic cells
Authors: Duarte Alejandra , Castillo Ana Fernanda , Castilla Rocío , Maloberti Paula , Paz Cristina , Podestá Ernesto J. , Cornejo Maciel Fabiana
Published: July 2007

Recent studies demonstrated the importance of the mitochondrial ATP in the regulation of a novel long‐chain fatty acid generation/export system in mitochondria of diabetic rat heart. In steroidogenic systems, mitochondrial ATP and intramitochondrial arachidonic acid (AA) generation are important for steroidogenesis. Here, we report that mitochondrial ATP is necessary for the generation and export of AA, steroid production and steroidogenic acute regulatory protein induction supported by cyclic 3′–5′‐adenosine monophosphate in steroidogenic cells. These results demonstrate that ATP depletion affects AA export and provide new evidence of the existence of the fatty acid generation and export system involved in mitochondrial cholesterol transport.
Identification of genes encoding microbial glucuronoyl esterases
Authors: Li Xin-Liang , Špániková Silvia , de Vries Ronald P. , Biely Peter
Published: July 2007

One type of covalent linkages connecting lignin and hemicellulose in plant cell walls is the ester linkage between 4‐O‐methyl‐d‐glucuronic acid of glucuronoxylan and lignin alcohols. An enzyme that could hydrolyze such linkages, named glucuronoyl esterase, occurs in the cellulolytic system of the wood‐rotting fungus Schizophyllum commune. Here we report partial amino acid sequences of the enzyme and the results of subsequent search for homologous genes in sequenced genomes. The homologous genes of unknown functions were found in genomes of several filamentous fungi and one bacterium. The gene corresponding to the cip2 gene of Hypocrea jecorina (Trichoderma reesei), known to be up‐regulated under conditions of induction of cellulolytic and hemicellulolytic enzymes, was over‐expressed in H. jecorina. The product of the cip2 gene was purified to homogeneity and shown to exhibit glucuronoyl esterase activity.
Parametric instabilities of circularly polarized small-amplitude Alfvén waves in Hall plasmas
Authors: RUDERMAN MICHAEL S. , CAILLOL PHILIPPE
Published: July 2007

We study the stability of circularly polarized Alfvén waves (pump waves) in Hall plasmas. First we re-derive the dispersion equation governing the pump wave stability without making anad hocassumption about the dependences of perturbations on time and the spatial variable. Then we study the stability of pump waves with small non-dimensional amplitudea(a≪ 1) analytically, restricting our analysis tob< 1, wherebis the ratio of the sound and Alfvén speed. Our main results are the following. The stability properties of right-hand polarized waves are qualitatively the same as in ideal MHD. For any values ofband the dispersion parameter τ they are subject to decay instability that occurs for wave numbers from a band with width of ordera. The instability increment is also of ordera. The left-hand polarized waves can be subject, in general, to three different types of instabilities. The first type is the modulational instability. It only occurs whenbis smaller than a limiting value that depends on τ. Only perturbations with wave numbers smaller than a limiting value of orderaare unstable. The instability increment is proportional toa2. The second type is the decay instability. It has the same properties as in the case of right-hand polarized waves; however, it occurs only whenb< 1 τ. The third type is the beat instability. It occurs for any values ofband τ, and only perturbations with the wave numbers from a narrow band with the width of ordera2are unstable. The increment of this instability is proportional toa2, except for τ close to τcwhen it is proportional toa, where τcis a function ofb.
‘HOW HARD AN ENTERPRISE IT IS’: AUTHORIAL SELF-FASHIONING IN JOHN DOWLAND’S PRINTED BOOKS
Authors: Gibson Kirsten
Published: July 2007

The naming of John Dowland as ‘Author’ on the title page of his publication The First Booke of Songes or Ayres (1597) suggests a proprietary relationship between the composer and his work. This proprietary relationship is, perhaps, reinforced with the alignment of Dowland’s intellectual activities as ‘author’ with the notions of ‘composition’ and ‘invention’ in the same passage. All three terms could be used by the late sixteenth century to refer to notions of creativity, individual intellectual labour or origination. While many early examples of the use of ‘author’ refer specifically to God or Christ as creator, such as Chaucer’s declaration that ‘The auctour of matrimonye is Christ’, by the sixteenth century it was increasingly used to refer to an individual originator of intellectual or artistic creation closer to the modern sense of the word. Its sixteenth-century usage is, for instance, reflected in the title ‘A tretys, excerpte of diverse labores of auctores’, or as in a reference in 1509 to ‘The noble actor plinius’. Likewise, ‘invent’ or ‘inventor’ could be used to refer to the process of individual intellectual creation, exemplified by its use in 1576 ‘Your brain or your wit, and your pen, the one to invent and devise, the other to write’, while ‘compose’ could mean to make, to compose in words, ‘to write as author’ or, more specifically, to write music.
A RIDDLE AND A SONG: PLAYING WITH SIGNS IN A FOURTEENTH-CENTURY BALLADE
Authors: Lefferts Peter M.
Published: July 2007

In a rich and learned article, Lawrence Gushee explored the tabula monochordi of Magister Nicolaus de Luduno. The tabula, which was copied into a music theory manuscript of c. 1400 of southern Italian provenance (Rome/St. Paul), consists of three associated parts. The first and third I shall call, following Gushee, the tabula figurarum (an elaborate musical example) and the tabula numerorum (an extremely elaborate table of corresponding information). Between them lies the enigmatic text of a six-stanza musical puzzle poem, ‘Ut pateat evidenter’, with which Gushee wrestled inconclusively. A concordance to the poem unknown to Gushee in an English music theory manuscript of about the same age (Bodley 842) associates these cryptic verses with a polyphonic chanson, a two-voice ballade that has never been published. The ballade is a sophisticated demonstration piece for tonal and mensural behaviours, and I believe that this song is the original complement and key to the poem’s meaning. It also offers a significant new point of entry into the complicated world of Anglo-French tonal theory as it developed in treatises and compositions of the fourteenth century.
Transient effects in oilfield cementing flows: Qualitative behaviour
Authors: MOYERS-GONZÁLEZ M. A. , FRIGAARD I. A. , SCHERZER O. , TSAI T.-P.
Published: July 2007

We present an unsteady Hele–Shaw model of the fluid–fluid displacements that take place during primary cementing of an oil well, focusing on the case where one Herschel–Bulkley fluid displaces another along a long uniform section of the annulus. Such unsteady models consist of an advection equation for a fluid concentration field coupled to a third-order non-linear PDE (Partial differential equation) for the stream function, with a free boundary at the boundary of regions of stagnant fluid. These models, although complex, are necessary for the study of interfacial instability and the effects of flow pulsation, and remain considerably simpler and more efficient than computationally solving three-dimensional Navier–Stokes type models. Using methods from gradient flows, we demonstrate that our unsteady evolution equation for the stream function has a unique solution. The solution is continuous with respect to variations in the model physical data and will decay exponentially to a steady-state distribution if the data do not change with time. In the event that density differences between the fluids are small and that the fluids have a yield stress, then if the flow rate is decreased suddenly to zero, the stream function (hence velocity) decays to zero in a finite time. We verify these decay properties, using a numerical solution. We then use the numerical solution to study the effects of pulsating the flow rate on a typical displacement.
Respiratory infection in congenital cardiac disease. Hospitalizations in young children in Spain during 2004 and 2005: the CIVIC Epidemiologic Study
Authors: Medrano Constancio , Garcia-Guereta Luis , Grueso Josefina , Insa Beatriz , Ballesteros Fernando , Casaldaliga Jaume , Cuenca Victorio , Escudero Fuensanta , Garcia de la Calzada Lola , Luis Maite , Luque Manuel , Mendoza Alberto , Prada Fredy , del Mar Rodríguez Maria , Suarez Pedro , Quero Concepción , Guilera Magda
Published: July 2007

Objectives

To evaluate the rate of hospitalization for acute respiratory tract infection in children less than 24 months with haemodynamically significant congenital cardiac disease, and to describe associated risk factors, preventive measures, aetiology, and clinical course.

Materials and methods

We followed 760 subjects from October 2004 through April 2005 in an epidemiological, multicentric, observational, follow-up, prospective study involving 53 Spanish hospitals.

Results

Of our cohort, 79 patients (10.4%, 95% CI: 8.2%–12.6%) required a total of 105 admissions to hospital related to respiratory infections. The incidence rate was 21.4 new admissions per 1000 patients-months. Significant associated risk factors for hospitalization included, with odds ratios and 95% confidence intervals shown in parentheses: 22q11 deletion (8.2, 2.5–26.3), weight below the 10th centile (5.2, 1.6–17.4), previous respiratory disease (4.5, 2.3–8.6), incomplete immunoprophylaxis against respiratory syncytial virus (2.2, 1.2–3.9), trisomy 21 (2.1, 1.1–4.2), cardiopulmonary bypass (2.0, 1.1–3.4), and siblings aged less than 11 years old (1.7, 1.1–2.9). Bronchiolitis (51.4%), upper respiratory tract infections (25.7%), and pneumonia (20%) were the main diagnoses. An infectious agent was found in 37 cases (35.2%): respiratory syncytial virus in 25,Streptococcus pneumoniaein 5, and Haemophilus influenzae in 4. The odds ratio for hospitalization due to infection by the respiratory syncytial virus increases by 3.05 (95% CI: 2.14 to 4.35) in patients with incomplete prophylaxis. The median length of hospitalization was 7 days. In 18 patients (17.1%), the clinical course of respiratory infection was complicated and 2 died.

Conclusions

Hospital admissions for respiratory infection in young children with haemodynamically significant congenital cardiac disease are mainly associated with non-cardiac conditions, which may be genetic, malnutrition, or respiratory, and to cardiopulmonary bypass. Respiratory syncytial virus was the most commonly identified infectious agent. Incomplete immunoprophylaxis against the virus increased the risk of hospitalization.
Hydrological sensitivity of the Adour‐Garonne river basin to climate change
Authors: Caballero Yvan , Voirin‐Morel Sophie , Habets Florence , Noilhan Joël , LeMoigne Patrick , Lehenaff Alain , Boone Aaron
Published: July 2007

Output atmospheric fields from seven global climate models (GCMs) were extracted over a domain covering the Adour‐Garonne basin in southwestern France in order to calculate precipitation and temperature anomalies for the decade 2050–2060 relative to the present climate. These anomalies showed a general trend of increasing precipitation in wintertime and decreasing precipitation in summertime, together with an increase in the annual average temperature of approximately 2°C. The anomalies were used to create seven modified climate‐forcing data sets, which were then used to drive the SAFRAN‐ISBA‐MODCOU (SIM) hydrometeorological modeling system. The river discharge simulated by the SIM model under each modified climate for the 2050–2060 decade was compared to the discharge simulated for the 1985–1995 reference decade. The results show a slight decrease in the low river flow, on the order of 11% ± 8% on average for all of the climate‐forcing data sets and the hydrometric stations. However, there was a significant impact on the snowpack in terms of reduced snow cover depth and duration. These changes provoked a discharge decrease in the spring and a large increase in winter due to the additional liquid precipitation. Considering the large range in climate conditions of the period studied, it appears that the hydrological sensitivity of the river basin is greater when applying the same climate modification to a wet year as opposed to a dry year. Finally, a transient climate forcing covering the 1985–2095 period provokes a general tendency to decrease the river discharge for all seasons.
Understanding dynamic of biogeochemical properties in the northern Adriatic Sea by using self‐organizing maps and k‐means clustering
Authors: Solidoro Cosimo , Bandelj Vinko , Barbieri Pierluigi , Cossarini Gianpiero , Fonda Umani Serena
Published: July 2007

The dynamic of biogeochemical properties in a coastal area of the northern Adriatic Sea (Gulf of Trieste) is analyzed through (1) identification of a small number of water typology classes and classification of samples, obtained by means of a novel multivariate classification procedure based on a combination of Artificial Neural Networks (ANN) and “traditional” clusterization algorithms, (2) interpretation of each class based on biogeochemical properties and ecological phenomena likely to occur in the water body, and (3) discussion of time evolution and spatial distribution of water classes which summarized and provided indications on the system's space and time evolution. Basing itself on a multivariate comparison, the Self‐Organizing Map (SOM) grouped 1292 samples collected in a 3‐year‐long monitoring program in 187 sets and identified a representative synthetic sample for each group. These groups were further classified in seven clusters, which identified the water typology. The complexity of the space and time coevolution of 12 variables was so reduced to variation of one categorical variable. Results included an objectively derived typology of water masses and their typical temporal succession, a spatial dividing based on biogeochemical processes, a conceptual scheme of biogeochemistry in the Gulf. Results clearly indicated the importance of river input in triggering plankton blooms and pointed out that trophodynamics followed current paradigms of marine ecosystem functioning, with shifts from conditions dominated by classical food chain to situations in which most of the energy flowed through the autotrophic and heterotrophic parts of the microbial food web.
Nutrients dynamics in the southern Bay of Biscay (1993–2003): Winter supply, stoichiometry, long‐term trends, and their effects on the phytoplankton community
Authors: Llope Marcos , Anadón Ricardo , Sostres Jorge Á. , Viesca Leticia
Published: July 2007

The southern Bay of Biscay is a very active region in terms of hydrography due to the interannual variations of its Central Waters, the recurrence of mesoscale features such as slope currents and upwellings, and the freshwater discharges from land. This highly dynamic physical environment influences to a great extent the biogeochemical cycles of nutrients beyond the seasonal cycle typical of middle latitudes. By using a monthly time series (1993–2003) of nitrate, nitrite, phosphate, and silicate consisting of three stations placed along a cross‐shelf transect, we assess the role of the physical forcing on nutrient seasonal and interannual dynamics within the upper 200 m, as well as the interactions with the biological component. The seasonal cycles of all nutrients and the stoichiometric balances (N:P and Si:N) are characterized along this coastal‐oceanic gradient. The year‐to‐year variations in the extent of the winter replenishment are analyzed in relation to the background Central Waters and presence/absence of the Iberian Poleward Current. In the long term we report decreasing linear trends of nitrate, nitrite, and silicate as well as an uncoupled nonlinear variation (i.e., cyclical) for all nutrients. Furthermore, we investigate the effect of this complex long‐term forcing on the phytoplankton: the linear trends are probably related to a decreasing primary production rate, while the nonlinear forcing may be responsible for controlling the community structure of phytoplankton.
Hyperspectral reflectance mapping of cinder cones at the summit of Mauna Kea and implications for equivalent observations on Mars
Authors: Guinness Edward A. , Arvidson Raymond E. , Jolliff Bradley L. , Seelos Kim D. , Seelos Frank P. , Ming Douglas W. , Morris Richard V. , Graff Trevor G.
Published: July 2007

Atmospherically corrected, hyperspectral reflectance data (0.4 to 2.5 μm) derived from the Airborne Visible Infrared Imaging Spectrometer (AVIRIS), validated with field‐based traverses and laboratory analyses, were used to map the distribution of ferric oxide, sulfate, and phyllosilicate minerals exposed on fresh and altered cones on the summit of Mauna Kea Volcano, Hawaii. Spectra from 0.4 to 1.1 μm exhibit charge‐transfer and electronic transition features related to hematite, nanophase iron oxide, and possibly jarosite, whereas spectra from 2.0 to 2.5 μm are characterized by cation‐OH features related to kaolinite, montmorillonite, and saponite. Unaltered cones exhibit concentric zoning of iron oxide signatures with crystalline hematite located near the summits and nanophase iron oxide signatures found at the base of cones and on flow surfaces. Altered cones (Puu Poliahu and Puu Waiau) have exposures of three phyllosilicate and possible jarosite units. In some cases there is zoning with a core of saponite surrounded by montmorillonite. Kaolinite is only found in two exposures on Puu Poliahu with one exposure coinciding with a possible jarosite unit. The relatively small spatial scale associated with alteration zones seen on Mauna Kea demonstrates the importance of obtaining high spatial resolution hyperspectral observations of Mars.