bluuebunny/crossref_metadata_2025_split huggingface dataset:
The influence of body size, breeding experience and environmental variability on egg size in the northern fulmar (Fulmarus glacialis)
Authors: Michel Pascale , Ollason Janet C. , Grosbois Vladimir , Thompson Paul M. 
Published: December 2003

AbstractProcellariform seabirds provide a good model for studies of the causes and consequences of variability in avian egg size, because females can only adjust reproductive investment by breeding intermittently, or by altering the size of their single egg. Maternal characteristics such as age, breeding experience and body size, as well as environmental variability, can influence egg size, but the effect of these factors has rarely been assessed simultaneously in the same study. Previous studies in Scotland have shown that the egg size of northern fulmars Fulmarus glacialis increased in relation to breeding experience. At this colony the influence of breeding experience, body size and inter‐annual variability upon egg size was tested simultaneously. Data collected over seven breeding seasons between 1975 and 2002 showed that egg size varied significantly both between years and in relation to the length of the breeding experience of females, but that female body size explained most variation in egg size. Inter‐annual variability in egg size was not related to the winter North Atlantic Oscillation, which had recently been shown to influence other measures of reproductive success at this colony. Larger eggs also seem to be more likely to produce successful fledglings. These findings are discussed in relation to the relative contribution of egg quality and parental quality on increased reproductive success.
Communal nesting in the usually solitary marsupial, Phascogale tapoatafa
Authors: Rhind Susan G. 
Published: December 2003

AbstractThe marsupial brushtailed phascogale Phascogale tapoatafa is a solitary, hollow‐dependent, arboreal insectivore that occurs at low densities in open forests and woodlands of Australia. Data gathered from nest box surveys (4 years), and from radio‐tracking phascogales to nest sites (3 years) in south‐western Australia confirm solitary nesting after dispersal. However, in the winter of a single year, nest box surveys in one study area showed that 56% of individuals were nest sharing. On a neighbouring site, 81 group nests were also recorded among 18 radio‐collared individuals. In both areas, groups comprised two to four individuals of any age/sex combination. The same phascogales tended to nest together and in a number of different sites. Nest sharing between females was restricted to territory boundaries and continued after the annual die‐off of the males. Nest sharing coincided with prolonged drought conditions and in this year mature phascogales were significantly smaller than normal, i.e. males 25% less in weight, females 12% less. Communal nesting seemed to be a response to thermoregulatory difficulties posed by the three interrelated factors of low body mass, declining temperatures and declining food availability. Nest sharing in this species appeared to be a behavioural indicator of an energetics crisis, there was a population decline during the drought period and a population crash in the following year.
Host fidelity of a symbiotic porcellanid crab: the importance of host characteristics
Authors: Thiel Martin , Zander Anke , Valdivia Nelson , Baeza Juan A. , Rueffler Claus 
Published: December 2003

AbstractThe social behaviour of symbiotic organisms is influenced by the density and distribution pattern of hosts. Herein we examined the host‐use behaviour of the anemone‐dwelling crab Allopetrolisthes spinifrons (Porcellanidae) in which adults usually live as solitary individuals on their hosts. Adults of this crab use two different sea anemone species, one intermediate‐sized species that can be found at relatively high densities in the intertidal zone and another large one that occurs at significantly lower densities in the shallow subtidal zone along exposed rocky shores of the south‐east Pacific. Mark–recapture experiments demonstrated that crabs in subtidal waters (low abundance of hosts) remained for long time periods on the same hosts while crabs in the intertidal environment (high abundance of hosts) frequently changed hosts. There were no differences in host fidelity between male and female crabs. In an immigration experiment in the intertidal zone, significantly more juveniles immigrated than had been present originally, indicating that host‐use behaviour is age dependent. The sex ratio between resident and immigrated individuals did not change. In an additional experiment hosts were planted at two different densities (high and low) both in the shallow subtidal and the intertidal zone to test whether host fidelity of crabs depends on distance between hosts. At the subtidal site, about half the crabs remained on their sea anemones for 14 days while at the intertidal site most crabs disappeared within 1 day in both density treatments. At both sites crabs were seen changing hosts in high density treatments, but no such events could be witnessed at low densities of hosts. Although the results are not fully conclusive, they suggest that host movements are affected by host densities. This relationship may be mediated by host (anemone species, size, distance) and site‐specific (predation pressure, exposure time) factors. In general, the present study indicates that host characteristics influence host fidelity of symbiotic organisms and thereby, their social behaviour.
The functional morphology of Bentholyonsia teramachii (Bivalvia: Lyonsiellidae): clues to the origin of predation in the deep water Anomalodesmata
Authors: Morton Brian 
Published: December 2003

Abstract Bentholyonsia teramachii has hitherto been described from Japan, but a conspecific specimen is herein recorded from Western Australian shelf waters at a depth of ∼100 m. Hitherto placed in the Lyonsiidae, B. teramachii is herein relocated in the Lyonsiellidae, alongside a second genus –Lyonsiella. Features of the anatomy of Bentholyonsiateramachii, including highly sensory siphons, reduced ctenidia unable to collect and transport particulate food, non‐sorting labial palps, and a simplified Type II stomach and muscular gut all suggest that the species is a predator like Lyonsiella formosa. Other features of the anatomy, such as pallial taenioid muscles, radial mantle glands, and the structure of the ctenidia all point to a link between B. teramachii and the Lyonsiellidae and thus with the Verticordiidae and Parilimyidae and, therefore, with some of the oldest anomalodesmatans, the Pholadomyidae. In the possession by B. teramachii of a unique pair of antero‐dorsal suspensory muscles, the link with fossil pholadomyoideans is reinforced. Bentholyonsia thus represents another genus of predatory bivalve, not only expanding our view of the prevalence of this feeding mode in the deep sea by this class but also helping us show how it evolved, in anatomical terms, from a suspension‐ (or deposit‐) feeding ancestor.
Sperm competition in Odonata (Insecta): the evolution of female sperm storage and rivals' sperm displacement
Authors: Córdoba‐Aguilar A. , Uhía E. , Rivera A. Cordero 
Published: December 2003

AbstractOdonates (dragonflies) are well known for the ability of the males to displace sperm stored in the female's sperm‐storage organs during copulation. By this means, copulating males are able to increase their fertilization success. This ability has been used as an example to illustrate a conflict of interests between the sexes in which males have evolved sperm‐displacement mechanisms whilst females have presumably evolved means to avoid sperm displacement. The present review has four aims: (1) to describe the copulatory mechanisms used during sperm displacement; (2) to analyse the causes of sperm usage patterns; (3) to discuss this information using current hypotheses on conflict between the sexes; and (4) to illuminate topics for further research. Four copulatory mechanisms are described: sperm removal (physical withdrawal of stored sperm), sperm repositioning (‘pushing’ of rival sperm to sites where its use will be least likely), female sensory stimulation to induce sperm ejection, and sperm flushing (displacement of sperm using the copulating male's sperm). Sperm‐precedence studies in Odonata are scarce and their values vary considerably between species. In those species in which sperm displacement is incomplete, the last copulating male obtains a high but variable short‐term fertilization success which decreases with time. Some male and female factors affecting sperm precedence patterns are mentioned: (1) male variation in genital morphology; (2) duration of copulation influenced by the male (the longer the copulation, the more stored sperm displaced); (3) adaptations of the sperm‐storage organs that allow the female to manipulate the sperm she has received (i.e. avoiding sperm displacement, re‐distributing sperm masses, favouring sperm located in certain sites and ejecting sperm after copulation). We suggest that male and female odonates have co‐evolved at the level of genital function with the control of stored sperm as the focus of the conflict. The benefits for males in this co‐evolution lie in maximizing their fertilization success. However, it is not clear what females obtain from storing sperm and making it unreachable during sperm displacement. Two hypothetical benefits that females may obtain for which some evidence has been gathered are genetic diversity and viability genes. It is finally suggested that odonates can become excellent subjects of study for testing current ideas related to sexual conflict and speciation processes through sexual selection.
A New HPLC‐ELSD Method To Quantify Indican in Polygonum tinctorium L. and To Evaluate β‐Glucosidase Hydrolysis of Indican for Indigo Production
Authors: Angelini Luciana G. , Campeol Elisabetta , Tozzi Sabrina , Gilbert Kerry G. , Cooke David T. , John Philip 
Published: December 2003

AbstractA method to quantify the indigo precursor indican (indoxyl‐β‐d‐glucoside) in Polygonum tinctoriumL. has been developed. Plant material was extracted in deionized water, and indican was identified and quantified using high performance liquid chromatography (HPLC) coupled to an evaporative light scattering detector (ELSD). Results confirmed that with this method it is possible to measure indican content in a short time, obtaining reliable and reproducible data. Using this method, leaf indican content was quantified every 15 days during the growing season (from May to October) in P. tinctorium crops grown in a field experiment in Central Italy. Results showed that indican increased along the growing season until flowering and was positively affected by photosynthetic active radiation (PAR). Indican is naturally hydrolyzed by native β‐glucosidase to indoxyl and glucose, the indoxyl yielding indigo. The activity of two enzymes, sweet almond β‐glucosidase and Novarom G preparation, were compared with P. tinctorium native β‐glucosidase to evaluate indigo production. Results showed that the ability to promote indigo formation increased as follows: almond β‐glucosidase ≤ Novarom G.
Application of Magnetic Agarose Support in Liquid Magnetically Stabilized Fluidized Bed for Protein Adsorption
Authors: Tong Xiao‐Dong , Sun Yan 
Published: December 2003

AbstractA novel magnetic agarose support (MAS) was fabricated for application in a liquid magnetically stabilized fluidized bed (MSFB). It was produced by water‐in‐oil emulsification method using a mixture of agarose solution and nanometer‐sized superparamagnetic Fe3O4 particles as the aqueous phase. The MAS showed good superparamagnetic responsiveness in a magnetic field. A reactive triazine dye, Cibacron blue 3GA (CB), was coupled to the gel to prepare a CB‐modified magnetic agarose support (CB‐MAS) for protein adsorption. Lysozyme was used as a model protein to test the adsorption equilibrium and kinetic behavior of the CB‐MAS. The dependence of bed expansion in the MSFB with a transverse magnetic field on liquid velocity and magnetic field intensity was investigated. Liquid‐phase dispersion behavior in the MSFB was examined by measurements of residence time distributions and compared with that obtained in packed and expanded beds. Dynamic lysozyme adsorption in the MSFB was also compared with those in packed and expanded beds. The dynamic binding capacity at 10% breakthrough was estimated at 55.8 mg/mL in the MSFB, higher than that in the expanded bed (31.1 mg/mL) at a liquid velocity of 45 cm/h. The results indicate that the CB‐MAS is promising for use in liquid MSFB for protein adsorption.
Monte Carlo Simulation of LNCaP Human Prostate Cancer Cell Aggregation in Liquid‐Overlay Culture
Authors: Song Hong , O/Connor Kim C. , Lacks Daniel J. , Enmon Richard M. , Jain Shamik K. 
Published: December 2003

AbstractNeoplastic cells self‐assemble in liquid‐overlay cultures into multicellular spheroids that resemble micrometastases and avascular regions of larger tumors. A Monte Carlo simulation based on Meakinapos;s cluster‐cluster aggregation model resolved the physical mechanisms by which LNCaP human prostate cancer cells aggregate in this environment. The best‐fit solution suggests that LNCaP cells aggregate with an adhesion probability of 0.5% when they migrate within a radius of influence between cell centers of 180 μm, 10 times the cell diameter. The sweeping radius of influence is indicative of cell tethering and/or chemotaxis and results in an intrinsic rate of self‐aggregation that increases from k11 = 1.5 h‐1 for single cells to k1010 = 17.5 h‐1 for 10‐mers. Similar rates are predicted by Smoluchowskiapos;s collision theory (1), suggesting that they are inherent properties of LNCaP liquid‐overlay culture. Aggregates form more compact structures in culture than during simulation as measured by the fractal dimension: DF = 1.74 ± 0.04 for 10‐mers in culture vs DF = 1.25 ± 0.10 for simulated 10‐mers. Additional restructuring would further extend the radius of influence and diminish adhesion. Applications of this work include the production of highly viable spheroids for drug testing and basic oncological research.
Evaluation of Ion Exchange Resins for Removal of Inhibitory Compounds from Corn Stover Hydrolyzate for Xylitol Fermentation
Authors: de Mancilha Ismael Maciel , Karim M. Nazmul 
Published: December 2003

AbstractThe use of dilute acids to catalyze the hydrolysis of hemicellulose to its sugar constituents is well‐known and effective. However, a major problem associated with this pretreatment is the poor fermentability of the produced hydrolyzate as a result of the presence of the microorganismapos;s inhibitory compounds. In the present work, seven ion‐exchange resins were tested in order to detoxify corn stover hydrolyzate. Regarding xylose recovery, it was observed that more than 92% recovery was feasible. Furfural removal varied from 53.% to 99.%, and hydroxymethylfurfural (HMF) removal was effective between 37% and 100%. Acetic acid was totally removed by Purolite A 103 S resin. Corn stover hydrolyzate (CSH) treated with Purolite A 103 S, and Finex CS 14 GC resins, was tested as substrate for xylitol production using a yeast, Candida mogii. Product yields, Yp/s, of 0.41 and 0.37 g/g and cellular yields, Yx/s, of 0.24 and 0.13 g/g, respectively, were obtained using the two types of resin‐treated hydrolyzates.
Geranium Leaf Assisted Biosynthesis of Silver Nanoparticles
Authors: Shankar S. Shiv , Ahmad Absar , Sastry Murali 
Published: December 2003

AbstractDevelopment of biologically inspired experimental processes for the synthesis of nanoparticles is evolving into an important branch of nanotechnology. In this paper, we report on the use of Geranium (Pelargonium graveolens) leaf extract in the extracellular synthesis of silver nanoparticles. On treating aqueous silver nitrate solution with geranium leaf extract, rapid reduction of the silver ions is observed leading to the formation of highly stable, crystalline silver nanoparticles in solution. Transmission electron microscopy analysis of the silver particles indicated that they ranged in size from 16 to 40 nm and were assembled in solution into quasilinear superstructures. The rate of reduction of the silver ions by the geranium leaf extract is faster than that observed by us in an earlier study using a fungus, Fusarium oxysporum, thus highlighting the possibility that nanoparticle biosynthesis methodologies will achieve rates of synthesis comparable to those of chemical methods. This study also represents an important advance in the use of plants over microorganisms in the biosynthesis of metal nanoparticles.
Development of a Segmented Model for a Continuous Electrophoretic Moving Bed Enantiomer Separation
Authors: Thome Brian M. , Ivory Cornelius F. 
Published: December 2003

AbstractWith the recent demonstration of a continuous electrophoretic “moving bed” enantiomer separation at mg/h throughputs, interest has now turned to scaling up the process for use as a benchtop pharmaceutical production tool. To scale the method, a steady‐state mathematical model was developed that predicts the process response to changes in input feed rate and counterflow or “moving bed” velocities. The vortex‐stabilized apparatus used for the separation was modeled using four regions based on the different hydrodynamic flows in each section. Concentration profiles were then derived on the basis of the properties of the Piperoxan‐sulfated β‐cyclodextrin system being studied. The effects of different regional flow rates on the concentration profiles were evaluated and used to predict the maximum processing rate and the hydrodynamic profiles required for a separation. Although the model was able to qualitatively predict the shapes of the concentration profiles and show where the theoretical limits of operation existed, it was not able to quantitatively match the data from actual enantiomer separations to better than 50% accuracy. This is believed to be due to the simplifying assumptions involved, namely, the neglect of electric field variations and the lack of a competitive binding isotherm in the analysis. Although the model cannot accurately predict concentrations from a separation, it provides a good theoretical framework for analyzing how the process responds to changes in counterflow rate, feed rate, and the properties of the molecules being separated.
Continuous d‐Tagatose Production by Immobilized Thermostable l‐Arabinose Isomerase in a Packed‐Bed Bioreactor
Authors: Ryu Se‐Ah , Kim Chang Sup , Kim Hye‐Jung , Baek Dae Heoun , Oh Deok‐Kun 
Published: December 2003

Abstractd‐Tagatose was continuously produced using thermostable l‐arabinose isomerase immobilized in alginate with d‐galactose solution in a packed‐bed bioreactor. Bead size, L/D (length/diameter) of reactor, dilution rate, total loaded enzyme amount, and substrate concentration were found to be optimal at 0.8 mm, 520/7 mm, 0.375 h‐1, 5.65 units, and 300 g/L, respectively. Under these conditions, the bioreactor produced about 145 g/L tagatose with an average productivity of 54 g tagatose/L·h and an average conversion yield of 48% (w/w). Operational stability of the immobilized enzyme was demonstrated, with a tagatose production half‐life of 24 days.
Enzymatic Synthesis of 3′‐Hydroxyacetaminophen Catalyzed by Tyrosinase
Authors: Valero Edelmira , Lozano M. Isabel , Varón Ramón , García‐Carmona Francisco 
Published: December 2003

Abstract3′‐Hydroxyacetaminophen, a catechol metabolite of N‐acetyl‐p‐aminophenol (acetaminophen) and N‐acetyl‐m‐aminophenol (a structural analogue of acetaminophen and considered as a possible alternative because it is not hepatotoxic), is enzymatically synthesized for the first time using mushroom tyrosinase. Although reported to be weakly hepatotoxic in vivo, this catechol derivative of acetaminophen is not commercially available. This compound was obtained from its monophenolic precursor, acetaminophen, using the enzyme tyrosinase in the presence of an excess of ascorbic acid, thus reducing back the o‐quinone product of catalytic activity to the catechol acetaminophen derivative. A mathematical model of the system is proposed, which is also applicable to the tyrosinase‐mediated synthesis of any o‐diphenolic compound from its corresponding monophenol. This synthesis procedure is continuous, easy to perform and control, and adaptable to a bioreactor with the immobilized enzyme for industrial purposes in a nonpolluting way.
Electrophysiological and Morphological Characterization of Rat Embryonic Motoneurons in a Defined System
Authors: Das Mainak , Molnar Peter , Devaraj Halagowder , Poeta Matthew , Hickman James J. 
Published: December 2003

AbstractIn an attempt to integrate biological components with silicon‐based devices and systems, artificial silane surfaces have been successfully used to grow motoneurons in a defined environment. In this study we characterized the morphology and electrophysiology of purified rat embryonic (E14) motoneurons grown on a self‐assembled monolayer (SAM) of N‐1[3‐(trimethoxysilyl)propyl]diethylenetriamine (DETA) versus that on ornithine/laminin surfaces in serum‐free media. On DETA motoneurons were flat and grew more processes, whereas on ornithine/laminin they tended to aggregate. The membrane time constant, a characteristic associated with electrotonic compactness, was significantly longer for motoneurons grown on DETA. Other electrophysiological parameters were similar for the motoneurons on the different surfaces. This is the first study where purified ventral horn motoneurons were cultured in a completely defined (nonbiological surface, serum‐free) environment.
Improving the Industrial Production of 6‐APA: Enzymatic Hydrolysis of Penicillin G in the Presence of Organic Solvents
Authors: Abian Olga , Mateo César , Fernández‐Lorente Gloria , Guisán José M. , Fernández‐Lafuente Roberto 
Published: December 2003

AbstractThe hydrolysis of penicillin G in the presence of an organic solvent, used with the purpose of extracting it from the culture medium, may greatly simplify the industrial preparation of 6‐APA. However, under these conditions, PGA immobilized onto Eupergit displays very low stability (half‐life of 5 h in butanone‐saturated water) and a significant degree of inhibition by the organic solvent (30%). The negative effect of the organic solvent strongly depended on the type of solvent utilized: water saturated with butanone (around 28% v/v) had a much more pronounced negative effect than that of methylisobutyl ketone (MIBK) (solubility in water was only 2%). These problems were sorted out by using a new penicillin G acylase derivative designed to work in the presence of organic solvents (with each enzyme molecule surrounded by an hydrophilic artificial environment) and a suitable organic solvent (MIBK). Using such solvent, this derivative kept its activity unaltered for 1 week at 32 °C. Moreover, the enzyme activity was hardly inhibited by the presence of the organic solvent. In this way, the new enzyme derivative thus prepared enables simplification of the industrial hydrolysis of penicillin G.