bluuebunny/crossref_metadata_2025_split huggingface dataset:
Endosymbiotic origins of sex
Authors: Bazinet Christopher 
Published: April 2004

AbstractUnderstanding how complex sexual reproduction arose, and why sexual organisms have been more successful than otherwise similar asexual organisms, is a longstanding problem in evolutionary biology. Within this problem, the potential role of endosymbionts or intracellular pathogens in mediating primitive genetic transfers is a continuing theme. In recent years, several remarkable activities of mitochondria have been observed in the germline cells of complex eukaryotes, and it has been found that bacterial endosymbionts related to mitochondria are capable of manipulating diverse aspects of metazoan gametogenesis. An attempt is made here to rationalize these observations with an endosymbiotic model for the evolutionary origins of sex. It is hypothesized that the contemporary life cycle of germline cells has descended from the life cycle of the endosymbiotic ancestor of the mitochondrion. Through an actin‐based motility that drove it from one cell to another, the rickettsial ancestor of mitochondria may have functioned as a primitive transducing particle, the evolutionary progenitor of sperm. BioEssays 26:558–566, 2004. © 2004 Wiley Periodicals, Inc.
Insulator dynamics and the setting of chromatin domains
Authors: Fourel Geneviève , Magdinier Frédérique , Gilson Éric 
Published: April 2004

AbstractThe early discovery of cis‐regulatory elements able to promote transcription of genes over large distances led to the postulate that elements, termed insulators, should also exist that would limit the action of enhancers, LCRs and silencers to defined domains. Such insulators were indeed found during the past fifteen years in a wide range of organisms, from yeast to humans. Recent advances point to an important role of transcription factors in insulator activity and demonstrate that the operational observation of an insulator effect relies on a delicate balance between the “efficiency” of the insulator and that of the element to be counteracted. In addition, genuine insulator elements now appear less common than initially envisaged, and they are only found at loci displaying a high density of coding or regulatory information. Where this is not the case, chromatin domains of opposing properties are thought to confront each other at “fuzzy” boundaries. In this article, we propose models for both fixed and fuzzy boundaries that incorporate probabilistic and dynamic parameters. BioEssays 26:523–532, 2004. © 2004 Wiley Periodicals, Inc.
Left and right in the amphibian world: which way to develop and where to turn?
Authors: Malashichev Yegor B. , Wassersug Richard J. 
Published: April 2004

AbstractThe last decade has seen a dramatic increase in studies on the development, function and evolution of asymmetries in vertebrates, including amphibians. Here we discuss current knowledge of behavioral and anatomical asymmetries in amphibians. Behavioral laterality in the response of both adult and larval anurans to presumed predators and competitors is strong and may be related, respectively, to laterality in the telencephalon of adults and the Mauthner neurons of tadpoles. These behavior lateralities, however, do not seem to correlate with visceral asymmetries in the same animals. We briefly compare what is known about the evolution and development of asymmetry in the structure and function of amphibians with what is known about asymmetries in other chordate and non‐chordate groups. Available data suggest that the majority of asymmetries in amphibians fall into two independent groups: (1) related to situs viscerum and (2) of a neurobehavioral nature. We find little evidence linking these two groups, which implies different developmental regulatory pathways and independent evolutionary histories for visceral and telencephalic lateralizations. Studies of animals other than standard model species are essential to test hypotheses about the evolution of laterality in amphibians and other chordates. BioEssays 26:512–522, 2004. © 2004 Wiley Periodicals, Inc.
Bioprocess design and economic analysis for the commercial production of environmentally friendly bioinsecticides from Bacillus thuringiensis HD‐1 kurstaki
Authors: Rowe Gerald E. , Margaritis Argyrios 
Published: April 2004

AbstractA production process for B. thuringiensis (Bt) bioinsecticides was designed in detail, including alternative batch, low‐density fed‐batch (LDFB), and high‐density fed‐batch (HDFB) fermentation configurations. Capital and operating costs, as well as profitability based on simple rate of return, were performed using a purpose‐written FORTRAN program, explicitly analyzing production of a water‐based flowable product used in forestry applications.The total capital cost was $18 million (Canadian dollars) for a stand‐alone plant with base‐scale capacity of 3 × l07 billion international units (BIU)/year . Raw material costs amounted to $1.5 million yearly, of which approximately half was for formulation ingredients. Per‐unit production cost rose sharply for scales of less than 1 × 107 BIU/year, but was little affected by scale above 3 × 107 BIU/year. Product cost was much lower at all scales for a LDFB as opposed to batch fermentation process, but HDFB gave relatively little additional cost benefit. Profitability analysis performed by co‐varying scale and selling price showed that break‐even occurred at a price of $0.45/BIU for a batch process at base scale, while with LDFB fermentation the same production volume sold at $0.35/BIU gave a 12% rate of return. Since the assumed base scale would represent 8‐15% of current world Bt bioinsecticide production, based on value or volume, it was concluded that profitability would require some or all of the following elements: targeting higher‐value markets such as disease vector control, in addition to forestry; a potentially lower plant capacity (although at least 1 × 107 BIU/year;) and coproduction of other large‐volume microbial products to absorb capacity and match bioinsecticide output to market demand. © 2004 Wiley Periodicals, Inc.
The Photoisomerization Mechanism of Azobenzene: A Semiclassical Simulation of Nonadiabatic Dynamics
Authors: Ciminelli Cosimo , Granucci Giovanni , Persico Maurizio 
Published: April 2004

AbstractWe have simulated the photoisomerization dynamics of azobenzene, taking into account internal conversion and geometrical relaxation processes, by means of a semiclassical surface hopping approach. Both n→π* and π→π* excitations and both cis→trans and trans→cis conversions have been considered. We show that in all cases the torsion around the NN double bond is the preferred mechanism. The quantum yields measured are correctly reproduced and the observed differences are explained as a result of the competition between the inertia of the torsional motion and the premature deactivation of the excited state. Recent time‐resolved spectroscopic experiments are interpreted in the light of the simulated dynamics.
Cyclofunctionalization of Unsaturated Alcohols, Phenols, Acids, and Sulfonamides with 1‐Benzenesulfinyl Piperidine and Trifluoromethanesulfonic Anhydride.
Authors: Crich David , Surve Bhushan , Sannigrahi Mousumi 
Published: April 2004

AbstractFor Abstract see ChemInform Abstract in Full Text.
Enantioselective Lewis Acid Catalyzed Mukaiyama—Michael Reactions of Acyclic Enones. Catalysis by allo‐Threonine‐Derived Oxazaborolidinones.
Authors: Wang Xiaowei , Adachi Shinya , Iwai Hiroyoshi , Takatsuki Hiroshi , Fujita Katsuhiro , Kubo Mikako , Oku Akira , Harada Toshiro 
Published: April 2004

AbstractFor Abstract see ChemInform Abstract in Full Text.
Conversion of Alcohols, Thiols, Carboxylic Acids, Trimethylsilyl Ethers, and Carboxylates to Thiocyanates with Triphenylphosphine/Diethylazodicarboxylate/NH4SCN.
Authors: Iranpoor Nasser , Firouzabadi Habib , Akhlaghinia Batool , Azadi Roya 
Published: April 2004

AbstractFor Abstract see ChemInform Abstract in Full Text.
Facial Selectivity of the Ireland—Claisen Rearrangement of Allylic Esters of 2‐Methyl and 2‐Methoxycyclopentanecarboxylic Acids.
Authors: Gilbert John C. , Yin Jiandong , Fakhreddine Fatima H. , Karpinski Matthew L. 
Published: April 2004

AbstractFor Abstract see ChemInform Abstract in Full Text.
Zirconium‐Mediated Coupling Reactions of Amines and Enol or Allyl Ethers: Synthesis of Allyl‐ and Homoallylamines.
Authors: Barluenga Jose , Rodriguez Felix , Alvarez‐Rodrigo Lucia , Zapico Jose M. , Fananas Francisco J. 
Published: April 2004

AbstractFor Abstract see ChemInform Abstract in Full Text.
A Novel Preparation of 3‐Hydroxy‐3H‐indole‐3‐ethanamines and ‐3H‐indole‐3‐acetamides Having Either a 4‐Morpholinyl or 1‐Pyrrolidinyl Group at the 2‐Position.
Authors: Hayashi Toshikatsu , Nakai Yu‐ya , Yamada Fumio , Somei Masanori 
Published: April 2004

AbstractFor Abstract see ChemInform Abstract in Full Text.
Formal Asymmetric 1,3‐Dipolar Cycloaddition of Azomethine Ylides to (S)‐2‐p‐Tolylsulfinyl‐2‐cyclopentenone.
Authors: Ruano Jose Luis Garcia , Tito Amelia , Peromingo M. Teresa 
Published: April 2004

AbstractFor Abstract see ChemInform Abstract in Full Text.
Use of Cyclobutyl Derivatives as Intermediates in the Synthesis of 1,2a,3,8b‐Tetrahydro‐2H‐cyclobuta[c]chromenes.
Authors: Bernard Angela M. , Floris Costantino , Frongia Angelo , Piras Pier P. , Secci Francesco 
Published: April 2004

AbstractFor Abstract see ChemInform Abstract in Full Text.
Synthesis of 1,2,5,6‐/1,2,3,6‐Tetrahydropyridinyl‐tetrahydrocyclopentaisoxazole Derivatives.
Authors: Ahn Mija , Park Jung Mee , Lee Ihl‐Young Choi , Jung Myung Hee 
Published: April 2004

AbstractFor Abstract see ChemInform Abstract in Full Text.
Synthesis of Substituted Quinolines by Iron‐Catalyzed Coupling Reactions Between Chloroenynes and Grignard Reagents.
Authors: Seck Matar , Franck Xavier , Hocquemiller Reynald , Figadere Bruno , Peyrat Jean‐Francois , Provot Olivier , Brion Jean‐Daniel , Alami Mouad 
Published: April 2004

AbstractFor Abstract see ChemInform Abstract in Full Text.
Synthesis of Pyridazine Derivatives Through the Unexpected Intermediate 5‐Amino‐4‐cyano‐2,3‐dihydro‐furan‐2,3‐disulfonic Acid Disodium Salt.
Authors: Cacciari Barbara , Spalluto Giampiero , Ferretti Valeria 
Published: April 2004

AbstractFor Abstract see ChemInform Abstract in Full Text.
Condensed Pyridopyrimidines. Part 6. Synthesis of Novel Pyrano[3′,4′:6,7]pyrido[2,3‐d]pyrimidines.
Authors: Oganisyan A. Sh. , Noravyan A. S. , Grigoryan M. Zh. 
Published: April 2004

AbstractFor Abstract see ChemInform Abstract in Full Text.
Alternative Synthesis and Novel Oxidizing Ability of 6,9‐Disubstituted Cyclohepta[b]pyrimido[5,4‐d]pyrrole‐8(6H),10(9H)‐dione Derivatives.
Authors: Naya Shin‐ichi , Iida Yusuke , Nitta Makoto 
Published: April 2004

AbstractFor Abstract see ChemInform Abstract in Full Text.
Heterogeneous Reactions Affecting Chlorine Activation in the Troposphere
Authors: Gershenzon M. Yu. , Grigorieva V. M. , Il'in S. D. , Remorov R. G. , Shestakov D. V. , Zelenov V. V. , Aparina E. A. , Gershenzon Yu. M. 
Published: April 2004

AbstractFor Abstract see ChemInform Abstract in Full Text.
Preparation of microcapsules of W/O/W emulsions containing a polysaccharide in the outer aqueous phase by spray‐drying
Authors: Adachi Shuji , Imaoka Hanaho , Ashida Hiroko , Maeda Hirokazu , Matsuno Ryuichi 
Published: April 2004

AbstractA water‐in‐oil‐in‐water (W/O/W) multiple emulsion containing a hydrophilic substance, 1,3,6,8‐pyrenetetrasulfonic acid tetrasodium salt (PTSA), and a wall material in its inner and outer aqueous phases, respectively, was prepared by a two‐step emulsification using a rotor/stator homogenizer, and was further homogenized with a high‐pressure homogenizer. Maltodextrin or gum arabic were used as wall materials, and olive oil was used as the oily phase. The high encapsulation efficiency for PTSA (>0.9) was realized. The emulsion was spray‐dried to produce microcapsules of W/O/W type. The efficiencies of the microcapsules prepared with maltodextrin and gum arabic were 0.82 and 0.67, respectively. Stability of the microcapsules was examined at 37 °C and 12%, 33% and 75% relative humidity. Microcapsules prepared with maltodextrin were more stable than those prepared with gum arabic.
Studies on rancidity inhibition in frozen horse mackerel (Trachurus trachurus) by citric and ascorbic acids
Authors: Aubourg Santiago P. , Pérez‐Alonso Francisco , Gallardo José M. 
Published: April 2004

AbstractThis study is aimed to investigate the effect of aqueous solutions of citric acid (CA) and ascorbic acid (AA) on the lipid stability of horse mackerel (Trachurus trachurus) fillets and whole fish during frozen storage (up to 6 and 9 months, respectively) by means of a soaking pretreatment. Best oxidation inhibition results on fish fillets were obtained when employing a 0.5% CA solution. Lower (p<0.05) peroxide (month 3), thiobarbituric acid‐reactive substance (months 1 and 3) and fluorescent compound formation (month 6) values were obtained from CA‐treated fish fillets than from the untreated (blank control) and water‐treated (water control) fish fillets. In the case of whole fish, soaking pretreatment with a mixture consisting of 0.5% CA and 0.5% AA showed the best results in inhibiting oxidation, as lower (p<0.05) peroxide formation was observed at 6 and 9 months of frozen storage compared to the untreated or water‐soaked counterparts. Advantages of both acids (CA and AA) are discussed, and further studies based on the positive role of a CA‐AA mixture will be carried out to extend the shelf life of medium‐ and high‐fat content fish species during frozen storage.
Ultrastructural aspects of gonadal morphogenesis in Bufo bufo (Amphibia Anura) 1. sex differentiation
Authors: Falconi Rosanna , Dalpiaz Davide , Zaccanti Francesco 
Published: April 2004

AbstractThe morphogenesis of gonads in Bufo bufo tadpoles was studied, and ultrastructural differences between sexes were identified. All specimens analyzed initially developed gonads made up of a peripheral fertile layer (cortex) surrounding a small primary cavity. Subsequently a central layer of somatic cells (medulla) developed. Both layers were separated by two uninterrupted basal laminae between which a vestige of the primary cavity persisted. During female differentiation, the peripheral layer continued to be the fertile layer. In males, the central layer blended into the peripheral layer and the basal laminae disappeared. The somatic cells of the central layer came into direct contact with the germ cells; this did not occur in females. Testicular differentiation continued with the migration of germ cells towards the center of the gonad. The somatic elements surrounding the germ cells appeared to play an active role in their transfer to the center of the gonad. The peripheral layer shrank and became sterile. Two basal laminae then re‐formed to separate the fertile central layer from the peripheral sterile one. Germ cells have always been thought to perform a passive role in sex differentiation in amphibians. Following the generally accepted “symmetric model”, the mechanism of gonad development is symmetrical, with cortical somatic cells determining ovarian differentiation and medullary somatic cells determining testicular differentiation. In contrast, we found that sex differentiation follows an “asymmetric” pattern in which germ cells tend primarily toward a female differentiation and male differentiation depends on a secondary interaction between germ cells and medullary somatic cells. J. Exp. Zool. 301A:378‐388, 2004. © 2004 Wiley‐Liss, Inc.
In vivo mapping of spontaneous mammary tumors in transgenic mice using MRI and ultrasonography
Authors: Galiè Mirco , D'Onofrio Mirko , Calderan Laura , Nicolato Elena , Amici Augusto , Crescimanno Caterina , Marzola Pasquina , Sbarbati Andrea 
Published: April 2004

AbstractPurposeTo compare T1‐ or T2‐weighted magnetic resonance imaging (MRI) and ultrasonography (US) as tools for in vivo mapping of different tissue components in spontaneous tumors of transgenic mice.Materials and MethodsHuman‐like mammary adenocarcinomas from FVB/neuT transgenic mice were analyzed by T2‐weighted and T1‐weighted MRI at 4.7 Tesla and US and then, after excision, were paraffin‐embedded for histologic analysis. The histologic samples were prepared taking care to obtain sections that spatially matched the MRI and US images as precisely as possible.ResultsUS can obtain basic information such as the size of developing tumors in experimental animals and can identify necrotic areas. T2‐weighted MRI, especially if compared to T1‐weighted MRI and/or US, allows advanced analysis of morphologic aspects, with high resolution in the differentiation of details of necrotic areas such as coagulation, liquefaction, biphasic splitting of cysts, and fibrotic and lipidic infiltration.ConclusionOf the three methods, T2‐weighted MRI provides the most information about the anatomy of tumors. However, when distinctions between the different types of necrosis are not needed, US analysis is to be preferred for its practicality. J. Magn. Reson. Imaging 2004;19:570–579. © 2004 Wiley‐Liss, Inc.
Noise reduction in MR angiography with nonlinear anisotropic filtering
Authors: Du Jiang , Fain Sean B. , Gu Tianliang , Grist Thomas M. , Mistretta Charles A. 
Published: April 2004

AbstractPurposeTo evaluate three‐dimensional nonlinear anisotropic filtering in suppressing image noise in high spatial resolution magnetic resonance angiograms (MRA) acquired with hybrid undersampled projection reconstruction and phase contrast vastly undersampled isotropic projection reconstruction (PC‐VIPR).Materials and MethodsThree‐dimensional nonlinear anisotropic filtering was quantitatively analyzed and evaluated through the measurement of contrast to noise ratio (CNR) in PC‐VIPR images and contrast enhanced peripheral MRA images. To filter MRA images with ultra‐high spatial resolution and poor CNR, a spatial frequency dependent nonlinear anisotropic filtering algorithm was proposed that uses two‐step processing to filter the whole spatial frequency data.ResultsThree‐dimensional nonlinear anisotropic filtering was shown to be effective in suppressing noise and improving CNR in MRA with isotropic spatial resolution. Higher CNR was achieved using spatial frequency dependent nonlinear anisotropic filtering. A typical CNR gain of between 50–100% was shown in our studies.ConclusionThree‐dimensional nonlinear anisotropic filtering significantly improved CNR in MRA images with isotropic spatial resolution. Spatial frequency dependent nonlinear anisotropic filtering further improved CNR for MRA images with ultra‐high spatial resolution and low CNR. J. Magn. Reson. Imaging 2004;19:632–639. © 2004 Wiley‐Liss, Inc.
Pheochromocytoma with posthemorrhagic cystic degeneration: Magnetic resonance imaging findings
Authors: Goshima Satoshi , Kanematsu Masayuki , Kondo Hiroshi , Yokoyama Ryujiro , Hoshi Hiroaki , Moriyama Noriyuki 
Published: April 2004

AbstractWe describe in vivo and in vitro magnetic resonance imaging (MRI) findings of a pheochromocytoma with posthemorrhagic cystic degeneration in a 74‐year‐old man. The in vivo MR images showed the mass as an area of homogeneous moderate hyperintensity with a central area of intense hyperintensity outlined by a thin hypointense rim on a T2‐weighted image. The in vitro MR images showed a hyperintense rim around the central cystic area consistent with hemorrhage on T1‐weighted gradient‐echo images with short echo times (1.6 and 4.2 msec) and more distinctly revealed the blurring effect due to susceptibility of hemosiderin on those with long echo times (6 and 8 msec). Hemosiderin deposition caused by intraparenchymal hemorrhage in the pheochromocytoma can be appreciated on spoiled gradient‐echo images with different echo times, which is ordinarily included in the MRI protocol as phase‐shift imaging. J. Magn. Reson. Imaging 2004;19:640–644. © 2004 Wiley‐Liss, Inc.
1H metabolite relaxation times at 3.0 tesla: Measurements of T1 and T2 values in normal brain and determination of regional differences in transverse relaxation
Authors: Träber Frank , Block Wolfgang , Lamerichs Rolf , Gieseke Jürgen , Schild Hans H. 
Published: April 2004

AbstractPurposeTo measure 1H relaxation times of cerebral metabolites at 3 T and to investigate regional variations within the brain.Materials and MethodsInvestigations were performed on a 3.0‐T clinical whole‐body magnetic resonance (MR) system. T2 relaxation times of N‐acetyl aspartate (NAA), total creatine (tCr), and choline compounds (Cho) were measured in six brain regions of 42 healthy subjects. T1 relaxation times of these metabolites and of myo‐inositol (Ins) were determined in occipital white matter (WM), the frontal lobe, and the motor cortex of 10 subjects.ResultsT2 values of all metabolites were markedly reduced with respect to 1.5 T in all investigated regions. T2 of NAA was significantly (P < 0.001) shorter in the motor cortex (247 ± 13 msec) than in occipital WM (301 ± 18 msec). T2 of the tCr methyl resonance showed a corresponding yet less pronounced decrease (162 ± 16 msec vs. 178 ± 9 msec, P = 0.021). Even lower T2 values for all metabolites were measured in the basal ganglia. Metabolite T1 relaxation times at 3.0 T were not significantly different from the values at 1.5 T.ConclusionTransverse relaxation times of the investigated cerebral metabolites exhibit an inverse proportionality to magnetic field strength, and especially T2 of NAA shows distinct regional variations at 3 T. These can be attributed to differences in relative WM/gray matter (GM) contents and to local paramagnetism. J. Magn. Reson. Imaging 2004;19:537–545. © 2004 Wiley‐Liss, Inc.
Shape optimization of multi‐band antennas using the coupling between microgenetic algorithms and TLM method
Authors: Chu H. S. , Dubard J. L. , Staraj R. 
Published: April 2004

AbstractThis paper presents a new combination between transmission line matrix method (TLM) and microgenetic algorithm (µGA). This coupling is used to design patch shapes of microstrip and planar inverted—F antennas (PIFA) for broad‐band or multi‐band applications. Measured results of the µGA/TLM optimized designs show good agreement with TLM simulation. Copyright © 2004 John Wiley & Sons, Ltd.
Finite‐volume time‐domain (FVTD) modelling of a broadband double‐ridged horn antenna
Authors: Baumann Dirk , Fumeaux Christophe , Leuchtmann Pascal , Vahldieck Rüdiger 
Published: April 2004

AbstractThis paper demonstrates the suitability of the finite‐volume time‐domain (FVTD) method to analyse electromagnetic ‘real‐world’ problems. As a challenging example, a 1–18 GHz broadband double‐ridged horn antenna is chosen. The horn antenna consists of non‐orthogonal and curved parts and a small coaxial feeding that is modelled in detail. The simulation results of the far‐field patterns, the return loss and the gain are successfully compared to measurements. They show that the FVTD method—using an inhomogeneous tetrahedral mesh—is very well suited for simulating complex structures. Copyright © 2004 John Wiley & Sons, Ltd.
Culturally tuned emotional intelligence: an effective change management tool?
Authors: Herkenhoff Linda 
Published: April 2004

Abstract

This article is concerned with the potential influence of culture in managing emotions both in others and in ourselves, within a change management framework.
It is proposed that reframing emotional intelligence (EI) in terms of culture may support leaders when effecting change within their organizations.
For well over a decade anthropologists have suggested that cultures have conventions and norms that influence the management of emotions.
Cultural values create a commonality among members in how they interpret and subsequently respond to emotional issues.
A tripartite definition of cultural values, based on national, organizational and professional cultures, provides a framework for exploring several EI case study examples. These practical examples demonstrate how organizations have effected change by stepping outside of their immediate and obvious framework to examine the issues in a ‘culturally tuned’ manner.

Copyright © 2004 John Wiley & Sons, Ltd.