bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Anionic Polyamidoamine Dendrimers on the Crystallization of Calcium Carbonate by Delayed Addition Method
Authors: Keum Dong-Ki , Naka Kensuke , Chujo Yoshiki 
Published: August 2003

Abstract
We examined the crystallization of CaCO3 by changing the time of addition of the G1.5 and G3.5 poly(amidoamine) dendrimers to a calcium carbonate solution after incubation for several minutes (1, 3, 20, or 60 min) at 30 °C. Based on the fact that the crystal phase obtained in the absence of the dendrimer was calcite, the dendrimers effectively stabilized the most unstable vaterite particles, even delaying the addition time of the dendrimer for 60 min. As the delayed addition time of the G1.5 dendrimer increased from 0 to 60 min, the particle size increased from 1.2 ± 0.5 to 4.7 ± 0.7 μm. As the generation number of the dendrimer increased from G1.5 to G3.5, the particle size of the spherical vaterite decreased under the same condition. The present results suggest that the anionic PAMAM dendrimers effectively modified the metastable vaterite surface and inhibited the further growth of vaterite particles by changing the addition time.
Photochromic and Fluorescent Properties of a Diarylethene Dimer
Authors: Yagi Kyoko , Irie Masahiro 
Published: August 2003

Abstract
A diarylethene dimer connected with a diyne 1 (O–O) was synthesized. Upon irradiation with 350-nm light the colorless hexane solution of 1 (O–O) changed to a dark-blue solution, in which absorption maximum was observed at 574 nm. The color is due to the formation of the isomer having one closed-ring form 1 (O–C). 1 (O–C) emitted red fluorescence at 720 nm and the intensity reversibly changed along with the photochromic reaction.
Very Fast Enantioseparation in High-performance Liquid Chromatography Using Cellulose Tris(3,5-dimethylphenylcarbamate) Coated on Monolithic Silica Support
Authors: Chankvetadze Bezhan , Yamamoto Chiyo , Okamoto Yoshio 
Published: August 2003

Abstract
The combination of the high chiral recognition ability of cellulose tris(3,5-dimethylphenylcarbamate) (CDMPC) with the favorable dynamic properties of a silica-based monolithic chromatographic support allowed the baseline enantioseparation of 2,2,2-trifluoro-1-(9-anthryl)ethanol with the retention times of 7.2 and 18.5 s for the first and second eluted enantiomers, respectively. The separation was accomplished in 30 s which may be the shortest time in which baseline HPLC enantioseparations have been reported.
Construction and Photocurrent of Light-harvesting Polypeptides/Zinc Bacteriochlorophyll a Complex in Lipid Bilayers
Authors: Nagata Morio , Yoshimura Yoshimi , Inagaki Junichi , Suemori Yoshiharu , Iida Kouji , Ohtsuka Toshiaki , Nango Mamoru 
Published: August 2003

Abstract
Light-harvesting (LH) 1-type complexes consisting of LH polypeptides and zinc bacteriochlorophyll a (Zn–BChla) were stably assembled in DMPC lipid bilayers on an electrode at room temperature. Photoinduced electronic currents of which action spectra revealed two peaks corresponding to the Qy absorption bands of Zn–BChla complex due to the presence of LH1-type complex were observed.
Microporous Rhodium(II) 4,4′,4″,4″′-(21H,23H-porphine-5,10,15,20-tetrayl)tetrakisbenzoate. Synthesis, Nitrogen Adsorption Properties, and Catalytic Performance for Hydrogenation of Olefin
Authors: Sato Tomohiko , Mori Wasuke , Nozaki Kato Chika , Ohmura Tetsushi , Sato Tsubasa , Yokoyama Kayoko , Takamizawa Satoshi , Naito Shuichi 
Published: August 2003

Abstract
A novel microporous rhodium(II) coordination polymer, [Rh2(H2TCPP)] (1) (H2TCPP = 4,4′,4″,4″′-(21H,23H-porphine-5,10,15,20-tetrayl)tetrakis benzoic acid) was synthesized. The complex 1 showed high porosity of the micropores of 7.3 Å. The amount of nitrogen adsorbed by 1 was 2.87 mole per mole of Rh, which is about three times that of rhodium(II) fumarate and rhodium(II) terephthalate. Complex 1 also showed high turnover frequencies for the hydrogenation of ethylene and propene at ca. 200 K.
Polyfunctional fused heterocyclic compounds via indene‐1,3‐diones
Authors: Hassaneen Hamdi M. , Abdallah, Tayseer A. , Abdelhadi Hyam A. , Hassaneen, Huwaida M. E. , Pagni Richard M. 
Published: September 2003

Abstract2‐Dimethylaminomethylene‐ and 2‐ethoxymethylene‐1,3‐indendione 1a,b react with 6‐amino‐2‐thioxopyrimidin‐4(3H)‐one 2 in boiling acetic acid to give 2‐thioxo‐1,3‐dihydroindeno[3,2‐d]pyrimidino[4,5‐b]pyridine‐4,9‐dione (4). The latter compound reacts with hydrazonoyl chlorides 5a–c to afford products 12a–c. Formamidine 15 reacts with indene‐1,3‐dione in boiling ethanol to give acyclic compound 16, which cyclizes to 12a in boiling glacial acetic acid. Also, enaminone 1a reacts with heterocyclic amines 17a–e in boiling ethanol, affording the corresponding substitution products 18a–c, respectively. The latter products 18a–c cyclize in glacial acetic acid to give 19a–c, respectively. The structures of the newly synthesized compounds are established on the basis of chemical and spectroscopic evidence. © 2003 Wiley Periodicals, Inc. Heteroatom Chem 14:491–497, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10166
Chelate polymers. III. New polyazomethines of 5,5′‐methylene‐bissalicylaldehyde with siloxane diamines and their divalent metal complexes
Authors: Cazacu Maria , Marcu Mihai , Vlad Angelica , Tóth András , Racles Carmen 
Published: September 2003

AbstractNovel polymeric azomethines of 5,5′‐methylene‐bissalicylaldehyde with two siloxane diamines {H2N(CH2)3(CH3)2SiO[(CH3)2SiO]mSi(CH3)2(CH2)3NH2, where m = 0 or 6.5} were obtained. Their structures were confirmed by elemental and spectral [IR, ultraviolet–visible (UV–vis), and 1H NMR] analysis. The obtained polyazomethines were converted into the chelates of some divalent metals (copper, cobalt, and nickel). The resulting complexes were characterized by electronic and IR spectral measurements, elemental analysis, and thermal studies. From IR and UV–vis studies, the phenolic oxygen and imine nitrogen of the ligand were found to be the coordination sites. The thermogravimetric data indicated that the chelates were less stable than the corresponding ligands and that the thermostability depended on the siloxane segment length and the nature of the metal. Both the macromolecular ligands and the parts of the resultant chelates were soluble in common organic solvents, such as CHCl3, CH2Cl2, dimethylformamide, and dimethyl sulfoxide. The surface compositions of the ligands and some chelates were examined by X‐ray photoelectron spectroscopy. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 3169–3179, 2003
Regulation of D‐amino acid oxidase expression in the yeast Rhodotorula gracilis
Authors: Molla Gianluca , Motteran Laura , Piubelli Luciano , Pilone Mirella S. , Pollegioni Loredano 
Published: September 2003

AbstractRhodotorula gracilis is a oleaginous yeast which utilizes D‐amino acids as a source of carbon and/or nitrogen. D‐amino acid oxidase (DAAO), which converts D‐amino acids in the corresponding α‐keto acids and ammonia, is the first enzyme involved in the catabolism of D‐amino acids. DAAO activity is induced by the presence of D‐alanine, but the presence of the L‐isomer prevents induction by inhibiting the transport of D‐alanine into cells. To understand how DAAO expression is regulated, R. gracilis cells were grown on media containing different nitrogen and/or carbon sources. As a general rule, the level of DAAO mRNA reached a maximum after 15 h growth and preceded by ∼6 h the maximum level of DAAO activity. The inducer D‐alanine acts by increasing the rate of DAAO mRNA transcription: the increase in DAAO expression is due essentially to de novo synthesis. The presence of a supplemental carbon source (e.g. succinate or glucose) does not repress DAAO expression. Ammonium sulphate appears to have a negative effect on DAAO mRNA translation and on the expression of DAAO activity: DAAO is only partially active when the yeast is grown in the presence of D‐alanine and ammonium sulphate. The best expression of DAAO activity was obtained by growing the cells for 12 h at 30 °C in the presence of glucose and D‐alanine using cells pre‐cultured for 10 h on glucose and L‐alanine (0.99 U/mg protein, corresponding to ∼1.0% total proteins in the crude extract). Under these growth conditions a six‐fold increase in DAAO production was achieved. Copyright © 2003 John Wiley & Sons, Ltd.
The impact of controlled breeding on milk production in pastoral goats in northern Kenya: an application of polynomial growth curve fitting
Authors: HARY I. 
Published: August 2003

The paper investigates the effect of controlled seasonal breeding on milk production in a herd of Small East African (SEA) goats. Polynomial growth curve models were fitted to both daily and cumulative milk yield data obtained from an experiment conducted over a period of 4 years (1984–88) under simulated pastoral herd management in Isiolo District, northern Kenya. The experimental treatment consisted of six different mating seasons per year, which were replicated three times over the course of the experiment.Milk yields in the first 2 weeks of lactation were negatively affected (<400 g/day) when kidding took place between June and September, whereas maximum initial yields of about 450 to 550 g/day were achieved at the onset and during the long rainy season. Multiple peaks in milk yield curves were observed when a rainy season occurred after about the first half of the lactation period. In terms of total amount of milk produced until 28 weeks of lactation, the production system could benefit from the introduction of a restricted breeding management allowing does to be bred in the period from June to November, with total milk yields being estimated at approximately 60 kg of milk. Maximum milk production until weaning can be expected to be achieved by does mated between October and January (between 46 and 48 kg of milk). The present experiment has revealed that mating just prior to or during the long rainy season leads to low milk yields until weaning and significantly increases the incidence of early kid deaths.It is concluded that evaluating milk production in goat herds exposed to strong seasonal changes in forage supply is perhaps best carried out in terms of cumulative milk yields, instead of average daily yields, which are subject to large fluctuations. Furthermore, under these conditions fitting polynomial growth curves to longitudinal milk yield data using the general linear mixed model appears to be more appropriate than the estimation of non-linear algebraic lactation curves.
Dietary effects on the composition of pig slurry and on the plant utilization of pig slurry nitrogen
Authors: SØRENSEN P. , FERNÁNDEZ J. A. 
Published: August 2003

The composition of animal manure is influenced by the diet fed. Efforts are made to decrease nitrogen emission from pig production by optimizing diet composition. This normally results in a lower proportion of N excreted in urine relative to faeces, and may also influence the turnover and utilization of manure N after field application. The effects of pig feed composition on the excretion of urinary and faecal N, on the dynamics of manure N in soil and on the potential utilization of manure N in the field was studied. Growing pigs and sows were fed 12 different diets with variable contents of fibre and protein (with or without synthetic amino acids). Slurries consisting of a mixture of faeces and urine were stored according to common agricultural practice in Northern Europe. The plant availability of N in the resultant slurries originating from animals fed known diets was tested in small field plots with barley, under conditions with minimal N losses. Separate plots were fertilized with increasing amounts of mineral N. Nitrogen uptake in barley was determined and the utilization of slurry N was compared with that of mineral fertilizer N. The net release of mineral N and C from the slurries in soil was also measured in a parallel incubation study.The mineral fertilizer equivalent of pig slurry N was 72–100% and significantly influenced by feed fibre composition, but not significantly influenced by the protein content. There was a significant positive correlation between enzyme-digestible organic matter in the pig diet (measurement used for feed evaluation) and the plant availability of pig slurry N (R2=0·90). The ammonium content of stored pig slurry could not be used for prediction of the N availability since the net mineralization of pig slurry N was variable, but there was a significant negative correlation between the pig slurry C/N ratio and the plant availability of slurry N (R2=0·86).Increased dietary concentration of fermentable structural carbohydrates (e.g. by including sugar beet pulp in the diet) reduces the excretion of N in urine without affecting the availability of slurry total N, whereas an increased concentration of dietary fibre with a low fermentability (straw) results in less urinary N, but also a lower plant availability of slurry N.
Influences of cultivar, cultivation year and fertilizer rate on amount of protein groups and amount and size distribution of mono- and polymeric proteins in wheat
Authors: JOHANSSON E. , PRIETO-LINDE M. L. , SVENSSON G. , JÖNSSON J. Ö. 
Published: August 2003

Influences of cultivar and environment, i.e. cultivation year and fertilizer rate, on amount of protein groups and amount and size distribution of mono- and polymeric proteins, were investigated in four sets of wheat (Triticum aestivum L.). The cultivars were chosen in order to obtain a high range of variation in protein concentration and gluten strength. Environmental influences on protein concentration and gluten strength were investigated, as well as relations between variation in protein concentration and gluten strength and variation in protein groups and amount and size distribution of mono- and polymeric proteins.The results showed that cultivar and environmental influences giving rise to variation in protein concentration also gave rise to variation in most of the investigated protein components. Protein concentration was significantly positively correlated to the total amounts of glutenins and gliadins and amounts of most mono- and polymeric proteins. However, the correlation with the amount of gliadins and sodium dodecyl sulphate (SDS)-soluble mono- and polymeric proteins were often higher than the correlation to the glutenins and the SDS-insoluble mono- and polymeric proteins. Cultivar influences giving rise to variation in gluten strength were found to influence the relation between SDS-soluble and -insoluble polymeric proteins, leading to a significant positive correlation between the gluten strength and the percentage of total unextractable polymeric protein (TUPP) in the total polymeric protein and large unextractable polymeric protein (LUPP) in the total large polymeric protein. Environmental variation in gluten strength was found to be significantly positively correlated to SDS-insoluble proteins and negatively correlated to SDS-soluble proteins. This also led to a significant positive correlation with the percentage of LUPP and/or TUPP.
Environmental correlates of geographical variation in skull and mandible shape of the punaré rat Thrichomys apereoides (Rodentia: Echimyidae)
Authors: Monteiro Leandro R. , Duarte Luiza C. , dos Reis Sérgio F. 
Published: August 2003

AbstractThe pattern of correlations between geographic–environmental variables and geometric shape descriptors for the skull and mandible of Thrichomys apereoides was studied by recently developed combinations of geometry and multivariate statistical techniques. Environmental variables were obtained for each locality: altitude, mean temperature, rainfall, human population density, and vegetation type. The three views of the skull (dorsal, lateral and ventral) and the mandible were significantly associated with a latitudinal environmental gradient along the diagonal of open areas (caatinga and cerrado) throughout the range sampled. The populations from xeric environments presented relatively larger coronoid processes, larger jugals and wider snouts (related to the activity of jaw closing muscles). A correlation of patterns of shape variation from data sets of different skull views showed that lateral skull shape is the most informative view. Further studies are necessary to separate completely the contribution of genetic and environmental components to skull and mandible shape divergence among populations of T. apereoides.
Differential osmoregulatory capabilities of common spiny mice (Acomys cahirinus) from adjacent microhabitats
Authors: Shanas Uri , Afik Daniel , Scantlebury Michael , Haim Abraham 
Published: August 2003

AbstractThe osmoregulatory function of common spiny mice Acomys cahirinus living on opposite slopes of the lower Nahal Oren (‘Evolution Canyon’) on mount Carmel, Israel, was investigated by increasing the salinity of the water source whilst maintaining a high‐protein diet. The southern‐facing slope (SFS) of this canyon differs from the northern‐facing slope (NFS) as it receives considerably more solar radiation and consequently forms a more xeric, sparsely vegetated habitat. During the summer, mice living on the two opposite slopes significantly differed in their urine osmolality, which also increased significantly as dietary salinity increased. Offspring of wild‐captured mice, born in captivity, and examined during the winter, continued to show a difference in osmoregulatory function depending on the slope of origin. However, they differed from wild‐captured mice, as they did not respond to the increase in dietary salinity by increasing the concentration of their urine, but rather by increasing the volume of urine produced. This study shows that A. cahirinus occupying different microhabitats may exhibit differences in their ability to concentrate urine and thus in their ability to withstand xeric conditions. We suggest that they may also differ genetically, as offspring from the NFS and SFS retain physiological differences, but further studies will be needed to confirm this hypothesis.
Response of territorial males to the threat of sneaking in the three‐spined stickleback (Gasterosteus aculeatus): a field study
Authors: Le Comber Steven C. , Faulkes Chris G. , Formosinho Joana , Smith Carl 
Published: August 2003

AbstractAlternative mating tactics are found in many species, and may have important implications for population genetics and speciation. The existence of such alternative mating tactics is well‐documented in the three‐spined stickleback Gasterosteus aculeatus, and sneaking and egg‐stealing may occur in a significant proportion of matings under natural conditions. Sneaking can impose high costs on territorial males, both in terms of reduced reproductive output and caring for unrelated offspring. We ask whether territorial males adjust their behaviour in response to the risk of sneaking. In a field study of three‐spined sticklebacks on the Isle of Arran, Scotland, territorial males were presented with glass bottles containing either a male, a female or neither, to address whether territorial males were more aggressive to other males in the presence of a female, and whether territorial males courted females less in the presence of another male. Behavioural observations showed that territorial males did not behave more aggressively towards rival males in the presence of a female, but did reduce their rate of courtship towards females in the presence of rival males. We conclude that territorial males adopt behavioural strategies that may reduce their risk of reproductive parasitism.
An experimental assessment of invertebrate/vertebrate predation: the interaction between wolf spiders (Gladicosa pulchra) and terrestrial salamanders (Ambystoma maculatum)
Authors: Rubbo Michael J. , Townsend Victor R. , Smyers Scott D. , Jaeger Robert G. 
Published: August 2003

AbstractA series of laboratory experiments were conducted to determine if adult wolf spiders Gladicosa pulchra were capable of acting as predators of juvenile spotted salamanders Ambystoma maculatum. Spiders preyed upon salamanders in two of 20 trials and attacked salamanders in five trials. As attacks did not always kill salamanders, multiple attacks per trial were possible. A total of 11 attacks was observed: two complete attacks, and nine incomplete attacks. Attacks were considered complete if the spider inserted its chelicerae into the salamander and incomplete if the spider did not. In response to complete attacks, the salamander would flip onto its back. Salamanders occasionally responded to incomplete attacks by continuously raising and lowering their heads. To our knowledge, this behaviour is undescribed in this group of salamanders. An additional experiment investigated the influence of increased levels of salamander movement on this interaction. In this experiment, spiders preyed upon salamanders in one of eight trials and attacked salamanders in six trials (28 total attacks: four complete attacks, 24 incomplete attacks). The results of this study indicate that wolf spiders can prey upon juvenile spotted salamanders, and that the ecological relationship between wolf spiders and amphibians may be quite complex.
Structure and variability of bat social calls: implications for specificity and individual recognition
Authors: Pfalzer Guido , Kusch Jürgen 
Published: August 2003

AbstractCommunication sounds or ‘social calls’ of 16 European bat species (Chiroptera, Vespertilionidae) were recorded at a range of roost and foraging sites. A comparative analysis of more than 5400 individual calls for general structures and for inter‐ as well as intraspecific variability resulted in 50 types of calls, which differed by their specific structure and by the calling species. These types could be grouped into four different general types of calls, according to the kind and complexity of their structure, independent of the calling species. Distinct types of calls seem to have similar functions in different bat species. One general type may be used predominantly in female–infant interactions as an isolation or direction call, which serves as mutual recognition. This type of social call was also used in ‘tandem flights’ of pairs of bats, which might increase individual knowledge of roost sites and foraging success. A second type was used in mate attraction, and a further one in an aggressive context. The fourth one was used by hindered or distressed bats. The group of ‘aggressive’ calls is least variable, but the complex mating calls and isolation calls are very diverse. Species‐specific sound structures were identified, which allowed a computational species distinction. The measured inter‐individual variability of social calls should be significant for their functions in individual recognition. So, beyond common features concerning the frequency structure of bat social calls, interspecific differences, as well as the intraspecific variability of details of sonagraphic parameters, should elucidate the specific functions of the calls.