bluuebunny/crossref_metadata_2025 huggingface dataset:
Syntheses and structures of sulfilimine, sulfone diimine, and sulfoximine derivatives of a monocyclic thiophene, 3,4‐di‐tert‐butylthiophene
Authors: Nakayama Juzo , Otani Takashi , Sugihara Yoshiaki , Sano Yuki , Ishii Akihiko , Sakamoto Akira
Published: September 2002

The reaction of 3,4‐di‐tert‐butylthiophene (6a) with N‐[(p‐tolylsulfonyl)imino]‐phenyliodinane (TsN=IPh) in the presence of Cu(MeCN)4PF6 in MeCN at room temperature provided 3,4‐di‐tert‐butyl‐1‐[(p‐tolylsulfonyl)imino]‐1,1‐dihydrothiophene (3b),3,4‐di‐tert‐butyl‐1,1‐bis[(p‐tolylsulfonyl)imino]‐1,1‐dihydrothiophene (5a), and 1‐(p‐tolylsulfonyl)‐3,4‐di‐tert‐butylpyrrole (7a) as the principal products. The use of 20 molar amounts of 6a gave 3b in an increased yield of 61%. Treatment of 3,4‐di‐tert‐butylthiophene 1‐oxide (1a) with (CF3CO)2O or (CF3SO2)2O, followed by reactions with RSO2NH2, ROC(=O)NH2, or RCONH2, furnished a series of S‐imino derivatives (3b,c,e–h) of 6a, which carry an electron‐withdrawing substituent on the imino nitrogen atom. Treatment of the S‐imino derivative 3f (substituent on the nitrogen atom = COBu) with CF3CO2H gave an aminosulfonium salt (13), whose deprotonation led to the parent N‐unsubstituted 1‐imide derivative (3n). Treatment of 2,4‐di‐tert‐butylthiophene 1‐oxide (1b) with TsN=IPh in the presence of Cu(MeCN)4PF6 in MeCN at room temperature provided 2,4‐di‐tert‐butyl‐1‐[(p‐toluenesulfonyl)imino]‐1,1‐dihydrothiophene 1‐oxide (4e) in 81% yield. Hydrolysis of 4e by concentrated H2SO4 at room temperature furnished 2,4‐di‐tert‐butyl‐1‐imino‐1,1‐dihydrothiophene 1‐oxide (4f) in 89% yield. A pair of enantiomers of 4f were separated by high‐performance liquid chromatography (HPLC) on a chiral column, and their absolute configurations were determined by an X‐ray crystallographic analysis. Structures of sulfilimine, sulfone diimine, and sulfoximine derivatives of monocyclic thiophenes, obtained in these ways, are discussed based on spectroscopies (IR and 1H and 13C NMR) and X‐ray crystallographic analyses. © 2001 John Wiley & Sons, Inc. Heteroatom Chem 12:333–348, 2001
Reinvestigation on the halogenation of 1,1,2,3,4,5‐hexaphenylstannole
Authors: Saito Masaichi , Haga Ryuta , Yoshioka Michikazu
Published: September 2002

Halogenation of 1,1,2,3,4,5‐hexaphenylstannole was reinvestigated. Reaction of the stannole with 2 equiv. of bromine gave 1‐bromo‐4‐dibromophenylstannyl‐1,2,3,4‐tetraphenyl‐1,3‐butadiene. Reaction of the stannole with iodine gave similar results. Reaction of the stannole with 1 equiv. of bromine or iodine afforded 1‐halo‐4‐halodiphenylstannyl‐1,2,3,4‐tetraphenyl‐1,3‐butadiene, resulting from halogenation with the cleavage of the bond between tin and vinyl carbon. © 2001 John Wiley & Sons, Inc. Heteroatom Chem 12:349–353, 2001
New construction of p‐tolylsulfonyl‐substituted naphthalenes by thermal and photochemical cyclization of 1‐aryl‐4‐(methylthio)‐2‐(p‐tolylsulfonyl)‐1,3‐butadienes
Authors: Matsumoto Shoji , Takahashi Shinjiro , Ogura Katsuyuki
Published: September 2002

Transformation of 4‐(methylthio)‐1‐phenyl‐2‐(p‐tolylsulfonyl)‐1,3‐butadiene 1a was found to give 2‐(p‐tolylsulfonyl)naphthalene 3a either by the action of I2 in refluxing acetonitrile or by irradiation with a high‐pressure Hg lamp. An electron‐withdrawing group (p‐F or p‐CO2Me) on the phenyl ring retarded the thermal reaction, but the corresponding naphthalene derivative was efficiently produced by the photolysis in the presence of I2. The substituent effect of an electron‐donating methoxyl group is also reported. © 2001 John Wiley & Sons, Inc. Heteroatom Chem 12:385–391, 2001
Preparation and 31P NMR study of some low‐coordinated organophosphorus compounds bearing the 2,4‐di‐t‐butyl‐6‐isopropylphenyl group
Authors: Toyota Kozo , Matsushita Yoshiaki , Shinohara Naoyuki , Yoshifuji Masaaki
Published: September 2002

2‐Bromo‐1,5‐di‐t‐butyl‐3‐isopropyl‐benzene was prepared and converted to the 2,4‐di‐t‐butyl‐6‐isopropylphenyl‐substituted phosphonous dichloride, primary phosphine, diphosphenes, and dithioxophosphorane. The 31P NMR chemical shifts of these compounds are close to those of 2,4‐di‐t‐butyl‐6‐methylphenyl substituted congeners. © 2001 John Wiley & Sons, Inc. Heteroatom Chem 12:418–423, 2001
Preparation and reactions of water stable hypervalent 10‐Sn‐5 allyl ate complexes
Authors: Kojima Satoshi , Kondoh Fumihiro , Kawakami Jun‐ya , Yamamoto Yohsuke , Akiba Kin‐ya
Published: September 2002

Hypervalent 10‐Sn‐5 allyl and crotyl tin ate complexes bearing Martin ligands were prepared and found to be surprisingly stable in water. These compounds were found to react with aldehydes in the presence of weak Lewis acids such as LiBr to give the corresponding homoallyl alcohols. Product analysis of the reaction of the crotyl compounds indicated that the reaction occurred via a cyclic transition state unlike an acyclic transition state operative for widely utilized allyltrialkyltin reagents that are of ordinary valency. © 2001 John Wiley & Sons, Inc. Heteroatom Chem 12:425–430, 2001
The performance of sample selection estimators to control for attrition bias
Authors: Grasdal Astrid
Published: September 2002

Sample attrition is a potential source of selection bias in experimental, as well as non‐experimental programme evaluation. For labour market outcomes, such as employment status and earnings, missing data problems caused by attrition can be circumvented by the collection of follow‐up data from administrative registers. For most non‐labour market outcomes, however, investigators must rely on participants' willingness to co‐operate in keeping detailed follow‐up records and statistical correction procedures to identify and adjust for attrition bias. This paper combines survey and register data from a Norwegian randomized field trial to evaluate the performance of parametric and semi‐parametric sample selection estimators commonly used to correct for attrition bias. The considered estimators work well in terms of producing point estimates of treatment effects close to the experimental benchmark estimates. Results are sensitive to exclusion restrictions. The analysis also demonstrates an inherent paradox in the ‘common support’ approach, which prescribes exclusion from the analysis of observations outside of common support for the selection probability. The more important treatment status is as a determinant of attrition, the larger is the proportion of treated with support for the selection probability outside the range, for which comparison with untreated counterparts is possible. Copyright © 2001 John Wiley & Sons, Ltd.
Neuroleptic malignant syndrome with olanzapine associated with severe hypernatremia
Authors: Arnaout M. Samir , Antun Fouad P. , Ashkar Khalil
Published: September 2002

A 30‐year‐old white man with schizophrenia developed anorexia and nausea, and was admitted to hospital for confusion and delirium. He was on olanzapine, 10 days prior to admission. On admission, typical neuroleptic malignant syndrome (NMS) developed with elevated body temperature (39.7°C), obtundation, tremor, rigidity, diaphoresis, fluctuating pupillary diameter, tachycardia, labile hypertension, elevated serum creatine kinase and severe hypernatremia (190 meq/l). Olanzepine was stopped few days after admission to the hospital and the NMS manifestations resolved by hospital day 12. The patient had all of the major manifestations of NMS. There was no other likely explanation for his illness. This is the first case reported in which NMS was associated with olanzapine and extremely elevated levels of serum sodium. Copyright © 2001 John Wiley & Sons, Ltd.
Influence of reservoirs on solute transport: a regional‐scale approach
Authors: Kelly Valerie J.
Published: September 2002

Regional transport of water and dissolved constituents through heavily regulated river systems is influenced by the presence of reservoirs. Analysis of seasonal patterns in solute fluxes for salinity and nutrients indicates that in‐reservoir processes within large storage reservoirs in the Rio Grande and Colorado basins (southwestern USA) are superimposed over the underlying watershed processes that predominate in relatively unregulated stream reaches. Connectivity of the aquatic system with the landscape is apparently disrupted by processes within the reservoir systems; these processes result in large changes in characteristics for solute transport that persist downstream in the absence of significant inputs. Additionally, reservoir processes may be linked for upstream/downstream reservoirs that are located relatively close in a series. In contrast, the regional effect of in‐reservoir processes is negligible for solute transport through run‐of‐river reservoirs in the lower Columbia River (northwestern USA). Published in 2001 by John Wiley & Sons, Ltd.
A conceptual model of preferential flow systems in forested hillslopes: evidence of self‐organization
Authors: Sidle Roy C. , Noguchi Shoji , Tsuboyama Yoshio , Laursen Karin
Published: September 2002

Preferential flow paths are known to be important conduits of subsurface stormflow in forest hillslopes. Earlier research on preferential flow paths focused on vertical transport; however, lateral transport is also evident in steep forested slopes underlain by bedrock or till. Macropores consisting of decayed and live roots, subsurface erosion, surface bedrock fractures, and animal burrows form the basis of a ‘backbone’ for lateral preferential flow in such sites. Evidence from field studies in Japan indicates that although individual macropore segments are generally <0·5 m in length, they have a tendency to self‐organize into larger preferential flow systems as sites become wetter. Staining tests show clear evidence of interconnected macropore flow segments, including: flow within decayed root channels and subsurface erosion cavities; flow in small depressions of the bedrock substrate; fracture flow in weathered bedrock; exchange between macropores and mesopores; and flow at the organic horizon–mineral soil interface and in buried pockets of organic material and loose soil. Here we develop a three‐dimensional model for preferential flow systems based on distributed attributes of macropores and potential connecting nodes (e.g. zones of loose soil and buried organic matter). We postulate that the spatially variable and non‐linear preferential flow response observed at our Japan field site, as well as at other sites, is attributed to discrete segments of macropores connecting at various nodes within the regolith. Each node is activated by local soil water conditions and is influenced strongly by soil depth, permeability, pore size, organic matter distribution, surface and substrate topography, and possibly momentum dissipation. This study represents the first attempt to characterize the spatially distributed nature of preferential flow paths at the hillslope scale and presents strong evidence that these networks exhibit complex system behaviour. Copyright © 2001 John Wiley & Sons, Ltd.
Hydrobiogeochemistry of forest ecosystems in Japan: major themes and research issues
Authors: Ohte Nobuhito , Tokuchi Naoko , Shibata Hideaki , Tsujimura Maki , Tanaka Tadashi , Mitchell Myron J.
Published: September 2002

Hydrobiogeochemical information on forested watersheds in the Japanese archipelago is reviewed to qualitatively summarize the major factors affecting the hydrology and biogeochemistry of this region. Major features that distinguish Japanese forest watersheds from those of north central Europe and the northeast United States generally include higher temperature, greater precipitation and steeper topography. There have been three major themes in hydrobiogeochemistry research on Japanese forest ecosystems: (1) investigations of nutrient cycles with particular emphasis on the establishment and maintenance of forest ecosystems; (2) evaluations of streamwater chemistry as an output from the forest ecosystem; and (3) hydrological studies using biogeochemical tracers. High precipitation inputs during the growing season affect the seasonality of the streamwater NO3− concentration, resulting in different temporal patterns than those generally found in north central Europe and the northeast United States. The high alkalinity and pH of Japanese surface waters is due to the rapid weathering of relatively young soils that are generated by steep hillslopes. Warm temperatures and elevated soil moisture enhance high rates of mineral weathering. Hydrological studies using biogeochemical tracers have shown that the steep topography contributes to the highly heterogeneous movement of water within Japanese catchments. Copyright © 2001 John Wiley & Sons, Ltd.
Evaluation of a reproductive toxicity assay using Xenopus laevis: boric acid, cadmium and ethylene glycol monomethyl ether
Authors: Fort Douglas J. , Stover Enos L. , Bantle John A. , Dumont James N. , Finch Robert A.
Published: September 2002

Cadmium (Cd), boric acid (BA) and ethylene glycol monomethyl ether (EGME) were evaluated for reproductive and developmental toxicity in Xenopus laevis. Eight reproductively mature adult male and eight superovulated female Xenopus laevis were exposed to at least five separate sublethal concentrations of each material via the culture water for a period of 30 days. Four respective pairs were mated and the offspring evaluated for developmental effects; an evaluation of reproductive status was performed on the remaining four specimens. Ovary pathology, oocyte count, oocyte maturity and maturation capacity (germinal vesicle breakdown, GVBD) and necrosis were evaluated in the female, whereas testis pathology, sperm count, dysmorphology and motility were studied in the male. Based on this assessment, each test material exerted reproductive toxicity in Xenopus laevis, but with varying potencies. Adult female exposure to Cd and EGME particularly, and to a lesser extent to BA, resulted in transgenerational toxicity to the developing progeny. Further, this model appears to be a useful tool in the initial assessment and prioritization of potential reproductive toxicants for further testing. Copyright © 2001 John Wiley & Sons, Ltd.
Comparison of the biomechanics and histology of two soft‐tissue fixators composed of bioabsorbable copolymers
Authors: Powers Dennis L. , Sonawala Mehul , Woolf Shane K. , An Yuehuei H. , Hawkins Richard , Pietrzak William S.
Published: September 2002

The purpose of this study was to assess the dynamic in vitro and in vivo characteristics of two different bioabsorbable copolymer soft‐tissue fixation devices and to determine their efficacy in reattaching soft tissue to bone. Suretac® fixators (Smith & Nephew/Acufex MicroSurgical Inc., Northwood, MA), made of polyglyconate (2:1 glycolic acid:trimethylene carbonate), and Pop Rivets® (Arthrotek, Warsaw, IN), made of LactoSorb® (82% poly L‐lactic acid, 18% polyglycolic acid), were anchored into synthetic bone, and their pull‐out strengths were evaluated. The devices were also evaluated with the use of an in vivo goat model in which the medial collateral ligament (MCL) was elevated from the tibia and directly reattached. In the in vitro biomechanical study, the Suretac® fixators had negligible strength remaining by four weeks, whereas the Pop Rivets® retained 50% of their strength at 4 weeks, 20% at 8 weeks, and negligible strength at 12 weeks. The in vivo strength of MCL repairs affected by each implant was not statistically different at any of the time points. Histologically, both implants were absorbed by 52 weeks, and there was no appreciable adverse tissue response. In conclusion, both copolymer fixators were found to be biocompatible. The Pop Rivet® fixators demonstrated in vivo performance comparable to the Suretac® fixators, although the Pop Rivets® retained strength longer in vitro. Our results suggest that both devices provide adequate strength of fixation before degrading to allow the healing soft tissues to reach or surpass their native strength. © 2001 John Wiley & Sons, Inc. J Biomed Mater Res (Appl Biomater) 58: 486–495, 2001
Epigallocatechin gallate protects U937 cells against nitric oxide‐induced cell cycle arrest and apoptosis
Authors: Kelly Melissa R. , Geigerman Cissy M. , Loo George
Published: September 2002

Ingesting phenolic phytochemicals in many plant products may promote health, but the effects of phenolic phytochemicals at the cellular level have not been fully examined. Thus, it was determined if the tea phenolic phytochemical, epigallocatechin gallate (EGCG), protects U937 human pro‐monocytic cells against the nitrogen free radical, nitric oxide (•NO). Cells were incubated for 4–6 h with 500 μM S‐nitrosoglutathione (GSNO), which generates •NO, but this did not induce single‐strand breaks in DNA. Nevertheless, 82 ± 4% of GSNO‐treated cells, compared to only 39 ± 1% of untreated cells, were arrested in the G1‐phase of the cell cycle. However, dosing the GSNO‐treated cells with 9, 14, or 18 μg/ml of EGCG resulted in only 74 ± 8%, 66 ± 1%, and 43 ± 3% of the cells, respectively, in the G1‐phase. Exposing cells to GSNO also resulted in the emergence of a sub‐G1 apoptotic cell population numbering 14 ± 3%, but only 5 ± 2%, 5 ± 1%, and 2 ± 0% upon dosing of the GSNO‐treated cells with 9, 14, and 18 μg/ml of EGCG, respectively. Furthermore, exposing cells to GSNO resulted in greater cell surface binding of annexin V‐FITC, but binding was 41–89% lower in GSNO‐treated cells dosed with EGCG. Collectively, these data suggest that •NO or downstream products induced cell cycle arrest and apoptosis that was not due to single‐strand breaks in DNA, and that EGCG scavenged cytotoxic •NO or downstream products, thus reducing the number of cells in a state of cell cycle arrest or apoptosis. J. Cell. Biochem. 81: 647–658, 2001. © 2001 Wiley‐Liss, Inc.
Evaluation of a knowledge‐based potential of mean force for scoring docked protein–ligand complexes
Authors: Nobeli Irene , Mitchell John B. O. , Alex Alexander , Thornton Janet M.
Published: September 2002

The Biomolecular Ligand Energy Evaluation Protocol (BLEEP) is a knowledge‐based potential derived from high‐resolution X‐ray structures of protein–ligand complexes. The performance of this potential in ranking the hypothetical structures resulting from a docking study has been evaluated using fifteen protein–ligand complexes from the Protein Data Bank. In the majority of complexes BLEEP was successful in identifying the native (experimental) binding mode or an alternative of low rms deviation (from the native) as the lowest in energy. Overall BLEEP is slightly better than the DOCK energy function in discriminating native‐like modes. Even when alternative binding modes rank lower than the native structure, a reasonable energy is assigned to the latter. Breaking down the BLEEP scores into the atom–atom contributions reveals that this type of potential is grossly dominated by longer range interactions (>5 Å), which makes it relatively insensitive to small local variations in the binding site. However, despite this limitation, the lack, at present, of accurate protein–ligand potentials means that BLEEP is a promising approach to improve the filtering of structures resulting from docking programs. Moreover, BLEEP should improve with the continuously increasing number of complexes available in the PDB. © 2001 John Wiley & Sons, Inc. J Comput Chem 22: 673–688, 2001
Reassociation of fragments using multicentered multipolar expansions: peptide junction treatments to investigate electrostatic properties of proteins
Authors: Dardenne L. E. , Werneck A. S. , Oliveira Neto M. , Bisch P. M.
Published: September 2002

We report an analysis of three schemes for fragment reassociation using multicentered multipolar expansions derived from ab initio quantum wave functions at the Hartree–Fock/6‐31G* LCAO level, two of them involving single‐bond partitioning in the peptide bond region, and the third one using a partially overlapping procedure based on a methodology proposed by Vigné‐Maeder21 (OME—overlap of multipolar expansions—reassociation method). The effects of different peptide junction treatments in the derivation of molecular electrostatic potentials and molecular electric fields of three peptide sequences are discussed. The results show that the OME reassociation method gives a better and a more homogeneous description of both the potential and the electric field than the other two treatments. We conclude that the OME method is the most indicated for studies involving electrostatic properties of proteins. Our results also indicate that the use of multicentered multipolar expansions coupled to the OME treatment is the best choice in protein studies including solvent effects using, for example, a continuum boundary method to solve the linearized Poisson–Boltzmann equation. © 2001 John Wiley & Sons, Inc. J Comput Chem 22: 689–701, 2001
Porosity and surface characteristics of activated carbons produced from waste tyre rubber
Authors: Miguel Guillermo San , Fowler Geoffrey D , Dall'Orso Marco , Sollars Christopher J
Published: September 2002

Waste tyre rubber has proven to be a suitable precursor for the production of high quality activated carbons. The performance of these carbons in commercial applications such as water treatment or gas purification is highly dependent on their surface characteristics. This paper presents an in‐depth investigation on how production conditions may affect the yield and characteristics of activated carbons produced from tyre rubber. For this purpose, three tyre rubbers of different particle sizes were consecutively pyrolysed and then activated in a steam atmosphere at 925 °C using a laboratory‐scale rotary furnace. Activation was conducted at different intervals over 80–640 min to achieve different degrees of carbon burn‐off. The resulting carbons were analysed for their elemental composition, ash content and nitrogen gas adsorption characteristics. The BET and t‐plot models were used to investigate various aspects of their porosity and surface area characteristics. SEM analyses were also conducted for visual examination of the carbon surface. Results show that pyrolytic chars, essentially mesoporous materials, developed a very narrow microporosity during the initial stages of the activation process (up to 15–25 wt% burn‐off). Further activation resulted in the progressive enlargement of the average micropore width and a gradual development of the mesoporous structure. Total micropore volumes and BET surface areas increased continuously with the degree of activation to reach values up to 0.498 cm3g−1 and 1070 m2g−1 respectively, while external surface areas developed more rapidly at degrees of activation above 45 wt% burn‐off. Results presented in this work also illustrate that carbons produced from powdered rubber developed a narrower and more extensive porosity, both in the micropore and mesopore range, than those produced from rubber of a larger particle size.

© 2001 Society of Chemical Industry
Hydrolysis of carboxymethylcellulose with mixtures of cellulase and β‐1,4‐glucosidase
Authors: Bravo V , Páez M P , El‐Hadj M Aoulad , Reyes A , García A I
Published: September 2002

We studied the hydrolysis of carboxymethylcellulose at 50 °C and pH 4.9 with a commercial preparation of cellulase (Celluclast) supplemented with a commercial β‐1,4‐glucosidase product (Novozym). The initial concentration of carboxymethylcellulose was varied between 2 and 12.5 kg m−3 for assays with Celluclast and two Novozym/Celluclast ratios (0.5 and 1). We determined the conversion to glucose and the overall conversion in terms of glucose equivalent. Conversion to glucose turned out to be directly proportional to the product of experimental time multiplied by the concentration of Celluclast and the constant of proportionality increased concomitantly with the concentration of Novozym. Overall conversion remained unaffected by the concentration of Novozym.

© 2001 Society of Chemical Industry
Urachal remnants in asymptomatic children: Gray‐scale and color Doppler sonographic findings
Authors: Özbek Süha Süreyya , Pourbagher Mir Ali , Pourbagher Ayşin
Published: September 2002

Purpose

We undertook this study to evaluate the frequency of visualization and the sonographic appearances of urachal remnants (URs) in asymptomatic children.

Methods

One hundred eighty‐two children without any urachus‐related symptoms underwent sonography of the prevesical region and urinary bladder with high‐frequency transducers.

Results

A UR was visualized in 180 (99%) of the children. The URs had a mean length ± standard deviation of 13 ± 5 mm. Most of the URs were ovoid, and most demonstrated a moderate protrusion into the bladder cavity. The URs with a central echogenic area were larger than those without central echogenicity. In 36 (61%) of the 59 URs that were evaluated with color Doppler sonography, vascular signals were demonstrated within the lesion. The URs with internal vascular signals were significantly larger than those without internal vascular signals.

Conclusions

The gray‐scale and color Doppler sonographic characteristics of URs seem to be related to their size and their degree of involution rather than to the age of the child. We think that URs are present in almost all children. URs should be considered normal findings if they are asymptomatic and their length is not significantly greater than 22.5 mm, the 95th percentile in our study. © 2001 John Wiley & Sons, Inc. J Clin Ultrasound 29:218–222, 2001.
Crayfish freshwater adaptation starts in eggs: Ontogeny of osmoregulation in embryos of Astacus leptodactylus
Authors: Susanto Gregorius N. , Charmantier Guy
Published: September 2002

Osmoregulation was studied throughout the embryonic development of Astacus leptodactylus. Egg‐carrying females were held in freshwater (FW) and in three dilute seawater media (200, 400, 600 mosm kg–1, 6.8, 13.6, 20.4‰ salinity). In FW, changes in peri‐embryonic fluid (PEF) and (when available) embryonic hemolymph osmolality were followed from newly‐laid eggs to hatching (for an embryonic eye index, EI, of 430–450 μm) and in first‐stage juveniles. The PEF and/or hemolymph osmolality remained stable at about 360–380 mosm kg–1 from early to late (EI 410 μm) embryos; it decreased prior to hatching (EI 420 μm) and in newly‐hatched juveniles, down to 290 mosm kg–1. Artificial opening and removal of the egg membranes, followed by direct exposure to FW, demonstrated that the ability to hyper‐osmoregulate, and consequently to survive, in FW appears in embryos with EI ≥ 410 μm, i.e., only a few hours or days before hatching. Following a transfer to the dilute seawater media, the PEF/hemolymph osmolality increased slowly over 18–20 days and became isosmotic with the external media at 13.6 and 20.4‰. The embryos died at EI 380–395 μm in these media, and only at 6.8‰ was the development completed until successful hatch. These results demonstrate that (1) the embryos become able to osmoregulate in FW shortly before hatching, (2) the embryos are osmo‐protected in the eggs during their development, (3) embryonic development and hatching are possible up to a salinity of 7‰. These results are discussed in relation to freshwater adaptation of crayfish. J. Exp. Zool. 289:433–440, 2001. © 2001 Wiley‐Liss, Inc.
Disrupting the transforming activity of shrimp ras(Q61K) by deleting the CAAX box at the C‐terminus
Authors: Huang Chein‐Fuang , Chen Chau‐Huei , Chuang Nin‐Nin
Published: September 2002

BALB/3T3 cells were transformed by transfection with DNA encoding the mutated ras(Q61K) from shrimp Penaeus japonicus. Ras transcription and protein levels had increased significantly in the cells transfected with the S‐ras plasmid, compared to cells transfected with a control plasmid pcDNA3.1. The bacterially expressed GTP‐locked S‐Ras(Q61K) is successfully prenylated by rat protein geranylgeranyltransferase I (PGGTase I) and then polymerized with tubulin, in agreement with findings for GTP‐locked mammalian KB‐Ras(Q61K) in vitro. Shrimp protein farnesyltransferase (PFTase) of shrimp did not prenylate the GTP‐locked shrimp S‐Ras(Q61K) (Lin and Chuang. 1998. J Exp Zool 281:565–573), whereas rat PFTase efficiently catalyzed the farnesylation of GTP‐locked S‐Ras(Q61K). To investigate the effect of geranylgeranylation on cellular transformation, we generated S‐ras(Q61K) mutants with deletion of the CAAX box [S‐ras(Q61K)‐caax] or replacement of the CAAX box [S‐ras(Q61K)Kcaax] or replacement of the arginine‐rich domain [S‐ras(Q61K)K‐Lys] with corresponding sequences from rat KB‐ras(Q61K). BALB/3T3 cells transfected with DNA encoding S‐ras(Q61K), S‐ras(Q61K)KCAAX, S‐ras(Q61K)K‐Lys were transformed successfully, but S‐ras(Q61K)‐CAAX was defective in its ability to transform. Thus, prenylation at CAAX is required for transformation. Either the geranylgeranylated or the farnesylated S‐Ras(Q61K) was endowed with abilities to transform. The arginine‐rich region in S‐Ras or the lysine‐rich clusters from the rat KB‐Ras appear not essential for activity to transform. J. Exp. Zool. 289:441–448, 2001. © 2001 Wiley‐Liss, Inc.
Effects of photoperiod on pituitary gonadotropin levels in masu salmon
Authors: Amano Masafumi , Ikuta Kazumasa , Kitamura Shoji , Aida Katsumi
Published: September 2002

We examined the effects of photoperiod on pituitary levels of two types of gonadotropin (GTH), GTH I and GTH II, in masu salmon Oncorhynchus masou to study their mechanism of synthesis. In Experiment 1, the effects of long or short photoperiod combined with castration were examined using 8‐month‐old precocious males. Castration was carried out in early August and then the fish were reared under a short (8L16D) or long (16L8D) photoperiod for 60 days. In Experiment 2, the effects of photoperiod combined with testosterone treatment were examined using 12‐month‐old immature females. Silastic tubes containing testosterone (500 μg /fish) or vehicle were implanted intra‐peritoneally in early October. Fish were reared under 16L8D for 60 days, and then half of the fish were transferred to 8L16D, while the remaining fish were kept under 16L8D until Day 90. In Experiment 1, GTH I contents were higher under 16L8D than under 8L16D in the castrated group on Day 30. Moreover, GTH I contents were higher in the castrated group than the control group under 16L8D on Day 30. GTH II contents increased with testicular maturation in the control groups, whereas they remained at low levels in the castrated groups regardless of photoperiodic treatment. In Experiment 2, GTH I contents did not change remarkably in all the groups, while GTH II contents were remarkably increased by testosterone treatment regardless of photoperiodic treatment. These results indicate that the synthesis of GTH I and GTH II are differently regulated by photoperiod and testosterone in masu salmon. J. Exp. Zool. 289:449–455, 2001. © 2001 Wiley‐Liss, Inc.
Tenant characteristics and the choice of tenurial contracts in rural India
Authors: Chaudhuri Ananish , Maitra Pushkar
Published: September 2002

Existing theoretical models of land tenancy predict that more experienced workers will be offered tenancy contracts while the less experienced ones will be offered wage contracts. Using data from three Indian villages we map from the set of agent and plot‐level characteristics to the set of contracts offered on each plot. We find that tenants are older than wage labourers. In the set of tenants, older workers tend to be cash renters. Copyright © 2001 John Wiley & Sons, Ltd.
Genetic use restriction technologies and the diffusion of yield gains to developing countries
Authors: Goeschl Timo , Swanson Timothy
Published: September 2002

The focus of this paper is the analysis of genetic use restriction technologies (GURTs) from the perspective of the diffusion of crop improvements to developing countries. One of the possible consequences of genetic use restriction technologies is a distinct downward shift in the growth trajectories of agricultural productivity in developing countries by restricting the flow of innovations to which these countries have had access in the past. In this case, developing countries are likely to face cumulative losses in agricultural productivity growth as a result of widespread adoption of GURTs by crop innovators. This paper presents the results of a study on hybrid crops, a precursor technology, to establish the negative effect of use restriction technologies on diffusion and discusses the implications of widespread use of GURTs for developing countries. Copyright © 2000 John Wiley & Sons, Ltd.
Rotation of middle ear ossicles during cetacean development
Authors: Kinkel M.D. , Thewissen J.G.M. , Oelschläger H.A.
Published: September 2002

Cetacean middle ears are unique among mammals in that they have an elongated tympanic membrane, a greatly reduced manubrium mallei, and an incudal crus longum that is shorter than the crus breve. Elongation of the tympanic membrane and reduction of the manubrium is thought to be related to an evolutionary rotation of the incus and malleus out of the plane of the tympanic membrane. We examined if rotation also occurs during ontogeny by comparing the middle ears of two species of dolphins (Delphinus delphis, Stenella attenuata) at different stages of development. We observed that: the incus has the body and crural proportions as in terrestrial mammals early in development; the incudomallear complex rotates approximately 90° following ossification; the tympanic membrane is not elongated until relatively late in development. Therefore, some of the unique characteristics of the cetacean middle ear develop as modifications of an initially terrestrial‐like morphology. J. Morphol. 249:126–131, 2001. © 2001 Wiley‐Liss, Inc.
Optical biosensor investigation of interactions of biomembrane and water‐soluble cytochromes P450 and their redox partners with covalently immobilized phosphatidylethanolamine layers
Authors: Ivanov Y. D. , Kanaeva I. P. , Gnedenko O. V. , Pozdnev V. F. , Shumyantseva V. V. , Samenkova N. F. , Kuznetsova G. P. , Tereza A. M. , Schmid R. D. , Archakov A. I.
Published: September 2002

A phospholipid‐containing biochip was created by covalently immobilizing phospholipids on the optical biosensor's aminosilane cuvette and employed to monitor the interactions of the membrane and water‐soluble proteins in cytochrome P450‐containing monooxygenase systems with planary layers of dilauroylphosphatidylethanolamine (DLPE) and distearoylphosphatidylethanolamine (DSPE), differing in acyl chain length. It was shown that the full‐length membrane proteins—cytochrome P4502B4 (d‐2B4), cytochrome b5 (d‐b5) and NADPH‐cytochrome P450 reductase (d‐Fp)—readily incorporated into the phospholipids. The incorporation was largely due to hydrophobic interactions of membranous protein fragments with the phospholipid layer. However, electrostatic forces were also but not always involved in the incorporation process. They promoted d‐Fp incorporation but had no effect on d‐b5 incorporation. In low ionic strength buffer, no incorporation of these two proteins into the DSPE lipid layer was observable. Incorporation of d‐b5 into the DLPE layer was abruptly increased at temperatures exceeding phospholipid phase transition point. Incorporation of d‐2B4 was dependent on its aggregation state and decreased with increasing protein aggregability. Water‐soluble proteins either would not interact with the phospholipid layer (adrenodoxin) or would bind to the layer at the cost of only electrostatic (albumin) or both electrostatic and hydrophobic (P450cam) interactions. Copyright © 2001 John Wiley & Sons, Ltd.

Abbreviations used:

Ad

adrenodoxin

AS

aminosilane surface of biosensor cuvette

2B4 and b5

cytochromes 2B4 and b5

d‐ and t‐

full‐length and truncated forms of proteins

DLPE

1,2‐dilauroylphosphatidylethanolamine (C12:0)

DSPE

1,2‐distearoylphosphatidylethanolamine (C18:0)

EDC

1‐ethyl‐3‐(3‐dimethylaminopropyl) carbodiimide

Fp

NADPH‐cytochrome P450 reductase

K (Na)P

K(Na)‐phosphate buffer

KP/E

K‐phosphate buffer with 0.25 g/l Emulgen 913

NHS

N‐hydroxysuccinimide

P450cam

cytochrome P450cam

PBS/T

potassium/Tween buffer
Pathogenicity of mumps virus in the marmoset
Authors: Saika Shizuko , Kidokoro Minoru , Ohkawa Tokitada , Aoki Atuko , Suzuki Kazuyoshi
Published: September 2002

The neurovirulence of two mumps virus strains was compared using marmosets. Marmosets were inoculated intravenously with the wild‐type mumps virus Odate strain, resulting in evident meningitis in 1 of 3 marmosets at each of the weeks 3, 4, and 5 postinoculation, representing a total of 3 out of 9 marmosets. Nephritis, parotitis, pancreatitis, and tonsillitis were manifest in addition to central nervous system (CNS) sequelae. On the other hand, the Jeryl Lynn vaccine strain did not induce histopathological changes in the CNS and multiplication of the Jeryl Lynn strain was distinctly lower compared to that of the Odate strain in the marmoset. This is the first report to describe the induction of meningitis in non‐human primates after peripheral inoculation of a wild‐type mumps virus, presenting findings useful for the elucidation of the mechanism of infection and pathology of mumps virus in the CNS. The distinction observed between the Odate and Jeryl Lynn strains suggests the applicability of the marmoset model for the evaluation of any neurovirulence potential of vaccine strains. J. Med. Virol. 66:115–122, 2002. © 2002 Wiley‐Liss, Inc.
The spatial and temporal behaviour of the lower stratospheric temperature over the Southern Hemisphere: the MSU view. Part I: data, methodology and temporal behaviour
Authors: Compagnucci Rosa H. , Salles M. Alejandra , Canziani Pablo O.
Published: September 2002

The lower stratosphere monthly temperature anomalies over the Southern Hemisphere derived from soundings made by the Microwave Sounding Unit (MSU) between 1979 and 1997 are analysed. Specifically MSU channel 4 temperature retrievals are considered. Principal component (PC) analysis with the S‐mode approach is used in order to isolate grid points that covary in a similar manner and to determine the main features of their temporal behaviour. The first six PCs explain 81.3% of the variance and represent the different time variability patterns observed over the Southern Hemisphere for the ten area clusters determined by the method. The most important feature is common to all the PC score pattern–time series and corresponds to a negative linear trend present in almost all the Southern Hemisphere except over New Zealand and surrounding areas. The negative trend is largest over Antarctica. The remaining features of the temporal variability are different for each PC score and therefore for each cluster region over the Southern Hemisphere. The first PC score pattern shows the impact of the Chichón and Mt Pinatubo eruptions that each produced a 2‐year warming over the tropical and sub‐tropical lower stratosphere. This variability is orthogonal with the behaviour present over Antarctica. There are different anomalies between 1987 (El Niño) and 1988 (La Niña). This second PC does not show any evidence whatsoever of the volcanic eruptions. The semi‐annual wave is present in the anomaly recurrence at mid to high latitudes. Over very low latitudes, close to the Equator, the Quasi‐Biennial Oscillation (QBO) band of frequency is also present. Copyright © 2001 Royal Meteorological Society
Climate variability in Malawi, part 1: dry summers, statistical associations and predictability
Authors: Jury M. R. , Mwafulirwa N. D.
Published: September 2002

Climate variability and predictability over tropical southern Africa is studied using a Malawi summer rainfall index. Thermodynamic and circulation patterns are examined and statistical associations are analysed. Links with El Niño–southern oscillation (ENSO) and quasi‐biennial oscillation (QBO) phase are significant and consistent with those found for southern Africa. Correlations are mapped with respect to the Malawi rainfall index, and the regional expression of ENSO emerges quite clearly. Negative r values for sea‐surface temperature (SST) in the west Indian Ocean contrast with positive r values in the east Atlantic and Agulhas region. The thermodynamic pattern ‘anchors’ a standing Rossby wave, comprised of northwest–southeast‐oriented centres of action across the Mozambique Channel and southern Africa, and east of Madagascar to East Africa. A meandering of the sub‐tropical jet stream is an expression of the standing Rossby wave, leading to vertical motions over southern Africa. The pattern develops at least one season in advance, and predictive indices are extracted in the July–September season for use in a multivariate model to predict the Malawi summer rainfall. The three‐area SST index, formulated to capture the ENSO‐modulated Rossby wave pattern, is the most influential predictor, followed by air pressure over the east Indian Ocean and the stratospheric zonal wind anomaly (QBO). Skilful results are found, with a 55% hindcast fit and two‐thirds of tercile categories correctly forecast in independent tests. Copyright © 2002 Royal Meteorological Society.
Dynamics and glass transition of a starburst polymer from its low‐wavenumber Raman spectrum: neat poly(propylene imine) DAB‐dendr‐(CN)64
Authors: Rothschild Walter G. , Perrot Michel , Cavagnat Raymond M.
Published: September 2002

We obtained experimental correlation times, in the range 11–27 ps and at temperatures between 333 and 123 K, from the low‐wavenumber VH‐Raman spectra of starburst polymer poly(propylene imine) DAB‐dendr‐(CN)64 in its neat state which, we propose, quantify the deformational mobility of the entire system's propylene— N < [ethylene— CN]2 links of its branching pattern. An activation plot of the correlation times extrapolates to a crossover value of Tc≈225 K, which we assign as ‘spectral signature’ of the system's known, thermodynamic glass transition temperature TG = 233 K. Copyright © 2001 John Wiley & Sons, Ltd.
SERS study of some novel metal complexes derived from D‐glucosamine
Authors: Ye Yong , Hu Jiming , Zeng Yun'e
Published: September 2002

Copper(II), nickel(II), cobalt(III) and iron(III) complexes of D‐glucosamine, and their complexes with α‐glycine were synthesized. The eight novel metal complexes were characterized by means of IR, electronic absorption and 1H NMR spectroscopy. The surface‐enhanced Raman scattering (SERS) spectra of these complexes were studied and by comparison of the spectra information on the SER active sites and adsorption orientation of these complexes was obtained. Copyright © 2001 John Wiley & Sons, Ltd.
A SERS probe for adenyl residues available for intermolecular interactions. Part II—Reactive adenyl sites in highly diluted DNA
Authors: Grajcar Lydie , Huteau Valérie , Huynh‐Dinh Tam , Baron Marie‐Hélène
Published: September 2002

Surface‐enhanced Raman spectroscopy (SERS) with an (Ag)n+ substrate detects picomoles of adenyl residues (Ayl) in a mildly salted aqueous medium (10−2 M NaCl). Chloride binding to Ayl enhances the Ayl affinity for silver. The SER spectral profile provides information on Ayl orientation. If silver plasmons are closely related, Ayl SERS intensities depend on the extent of the adsorption. This allows us to compare Ayl availability in poly(dA), d(CCA AAA ACC) and d(GCC GAC CCG), in the corresponding double strands or in the self‐complementary d(CGA TCG) oligomer. Single‐strand self‐association constrains Ayl reactivity but less than duplex arrangements. Ayl reactivity is notably amplified in A tracts. In highly diluted poly(dA)–poly(dT) mixtures Ayl adsorption is available along flexible bulges. In the d(GCC GAC CCG).d(CGG GC GGC) duplex, where a thymidine is missing, Ayl is not more accessible than in the canonical duplex. Mg2+–nucleic acid complexation has a dual activity on the nucleic bases. At specific Mg2+ to nucleotide ratios, C6N/N7 Ayl sides are hidden in Mg2+ cross‐bridged structures involving homologous or complementary strands. Alternatively, below these ratios a 1 : 1 Mg2+–phosphate interaction enhances Ayl but also thymyl and cytosyl interactions with the electron‐depleted sites. Exploring salt effects and concentration dependences on nucleic base reactivity is crucial to predict elementary conditions for topological recognition in ‘living’ DNA, especially when temporarily unpaired or coiled in hairpins. Copyright © 2001 John Wiley & Sons, Ltd.
Glucose, fructose and sucrose content in broccoli, white cabbage and Portuguese cabbage grown in early and late seasons
Authors: Rosa Eduardo , David Manuela , Gomes Maria H
Published: September 2002

Consumption of Portuguese cabbage and white cabbage is very high in Portugal, but diets including broccoli have been highly recommended owing to recognition of the health‐protective effects of secondary plant metabolites. Broccoli production is generally concentrated in the summer/winter season, but the demand for a fresh product throughout the year requires production in other seasons. Sugars might affect flavour and the acceptance of broccoli by consumers. This study reports the free fructose, glucose and sucrose content in primary and secondary inflorescences of 11 cultivars of broccoli, one white cabbage and four Portuguese cabbages grown in early (March–July) and late (August–January) seasons in the northern region of Portugal. On average the results show that the total free sugar content in the broccoli cultivars, except for cv Marathon, is significantly (P < 0.05) lower than in the other cabbages. Fructose was the major sugar in the three types of Brassica, representing between 48.8 and 56.9% of the total sugar content in broccoli cvs Marathon and Senshi respectively and between 48.7% (cv Mirandela) and 53.8% (cv Murciana) in the other cabbages. Glucose was the second major sugar, while sucrose represented a maximum of 20.5% in broccoli cv Shogun and 11.1% in cv Murciana. The growing season influenced the free sugar content, with generally higher levels in the spring/summer than in the summer/winter season in broccoli, while an opposite tendency was noted in the other Brassica species. In broccoli the sugar levels in the primary inflorescences were generally lower than in the secondary inflorescences, except for sucrose.

© 2001 Society of Chemical Industry
Optimisation of enzymatic esterification of soybean oil deodoriser distillate
Authors: Facioli Nara Lúcia , Barrera‐Arellano Daniel
Published: September 2002

The enzymatic esterification of free fatty acids from soybean oil deodoriser distillate with ethanol, catalysed by immobilised fungal lipase, was studied. The extent of conversion of free fatty acids to ethyl esters was optimised using a response surface methodology obtained through a second‐order factorial experimental design. The variables studied were reaction temperature (30–70 °C), enzyme concentration (7–23%) and ethanol/free fatty acid molar ratio (0.3–3.7:1). The optimal reaction conditions achieved were temperature from 46.4 to 53.6 °C, enzyme concentration from 13.6 to 16.5% and ethanol/free fatty acid molar ratio from 1.7 to 2.3:1, with conversions above 88%. No significant tocopherol losses were observed during the process. In conclusion, enzymatic fatty acid esterification was shown to be a technically viable process.

© 2001 Society of Chemical Industry
An empirical approach to study the occurrence of ion exchange in the ionic micellar‐mediated semi‐ionic reactions: Kinetics of the rate of reaction of piperidine with ionized phenyl salicylate in the presence of cationic micelles
Authors: Khan M. Niyaz , Ismail Emaran
Published: September 2002

Pseudo‐first‐order rate constants (kobs)—obtained for the cleavage of ionized phenyl salicylate (PS−) at constant [NaOH], [MeCN], [CTAZ]T (total concentration of cetyltrimethylammonium chloride and bromide), [Pip]T (total concentration of piperidine), and varying concentrations of sodium cinnamate, acetate, and butanoate ([NaX])—follow the relationship: kobs = (k0 + θ K[NaX])/(1 + K[NaX]), where θ and K are empirical parameters. The values of θ are almost independent of [CTAZ]T, while K values decrease with the increase in [CTAZ]T within its range 0.006–0.020 M. The values of θ and K are explained in terms of pseudophase model of micelle coupled with an empirical relationship: KS = KS0/(1 + ΨX/S [NaX]), where KS is the CTAZ micellar binding constant of PS− in the presence of NaX. © 2001 John Wiley & Sons, Inc. Int J Chem Kinet 33: 288–294, 2001