bluuebunny/crossref_metadata_2025_split huggingface dataset:
4‐Hydroxyacetophenone monooxygenase from Pseudomonas fluorescens ACB
Authors: Kamerbeek Nanne M. , Moonen Mariëlle J. H. , van der Ven Jos G. M. , van Berkel Willem J. H. , Fraaije Marco W. , Janssen Dick B. 
Published: March 2003

A novel flavoprotein that catalyses the NADPH‐dependent oxidation of 4‐hydroxyacetophenone to 4‐hydroxyphenyl acetate, was purified to homogeneity from Pseudomonas fluorescens ACB. Characterization of the purified enzyme showed that 4‐hydroxyacetophenone monooxygenase (HAPMO) is a homodimer of ≈ 140 kDa with each subunit containing a noncovalently bound FAD molecule. HAPMO displays a tight coupling between NADPH oxidation and substrate oxygenation. Besides 4‐hydroxyacetophenone a wide range of other acetophenones are readily converted via a Baeyer–Villiger rearrangement reaction into the corresponding phenyl acetates. The P. fluorescens HAPMO gene (hapE) was characterized. It encoded a 640 amino‐acid protein with a deduced mass of 71 884 Da. Except for an N‐terminal extension of ≈ 135 residues, the sequence of HAPMO shares significant similarity with two known types of Baeyer–Villiger monooxygenases: cyclohexanone monooxygenase (27–33% sequence identity) and steroid monooxygenase (33% sequence identity). The HAPMO sequence contains several sequence motifs indicative for the presence of two Rossman fold domains involved in FAD and NADPH binding. The functional role of a recently identified flavoprotein sequence motif (ATG) was explored by site‐directed mutagenesis. Replacement of the strictly conserved glycine (G490) resulted in a dramatic effect on catalysis. From a kinetic analysis of the G490A mutant it is concluded that the observed sequence motif serves a structural function which is of importance for NADPH binding.
BJ46a, a snake venom metalloproteinase inhibitor
Authors: Valente Richard H. , Dragulev Bojan , Perales Jonas , Fox Jay W. , Domont Gilberto B. 
Published: March 2003

Fractionation of the serum of the venomous snake Bothrops jararaca with (NH4)2SO4, followed by phenyl‐Sepharose and C4‐reversed phase chromatographies, resulted in the isolation of the anti‐hemorrhagic factor BJ46a. BJ46a is a potent inhibitor of the SVMPs atrolysin C (class P‐I) and jararhagin (P‐III) proteolytic activities and B. jararaca venom hemorrhagic activity. The single‐chain, acidic (pI 4.55) glycoprotein has a molecular mass of 46 101 atomic mass units determined by MALDI‐TOF MS and 79 kDa by gel filtration and dynamic laser light scattering, suggesting a homodimeric structure. mRNA was isolated from the liver of one specimen and transcribed into cDNA. The cDNA pool was amplified by PCR, cloned into a specific vector and used to transform competent cells. Clones containing the complete coding sequence for BJ46a were isolated. The deduced protein sequence was in complete agreement with peptide sequences obtained by Edman degradation. BJ46a is a 322‐amino‐acid protein containing four putative N‐glycosylation sites. It is homologous to the proteinase inhibitor HSF (member of the fetuin family, cystatin superfamily) isolated from the serum of the snake Trimeresurus flavoviridis, having 85% sequence identity. This is the first report of a complete cDNA sequence for an endogenous inhibitor of snake venom metalloproteinases (SVMPs). The sequence reveals that the only proteolytic processing required to obtain the mature protein is the cleavage of the signal peptide. Gel filtration analyses of the inhibitory complexes indicate that inhibition occurs by formation of a noncovalent complex between BJ46a and the proteinases at their metalloproteinase domains. Furthermore, the data shows that the stoichiometry involved in this interaction is of one inhibitor monomer to two enzyme molecules, suggesting an interesting mechanism of metalloproteinase inhibition.
Genetic and biochemical characterization of a short‐chain alcohol dehydrogenase from the hyperthermophilic archaeon Pyrococcus furiosus
Authors: van der Oost John , Voorhorst Wilfried G. B. , Kengen Servé W. M. , Geerling Ans C. M. , Wittenhorst Vincent , Gueguen Yannick , de Vos Willem M. 
Published: March 2003

The gene encoding a short‐chain alcohol dehydrogenase, AdhA, has been identified in the hyperthermophilic archaeon Pyrococcus furiosus, as part of an operon that encodes two glycosyl hydrolases, the β‐glucosidase CelB and the endoglucanase LamA. The adhA gene was functionally expressed in Escherichia coli, and AdhA was subsequently purified to homogeneity. The quaternary structure of AdhA is a dimer of identical 26‐kDa subunits. AdhA is an NADPH‐dependent oxidoreductase that converts alcohols to the corresponding aldehydes/ketones and vice versa, with a rather broad substrate specificity. Maximal specific activities were observed with 2‐pentanol (46 U·mg−1) and pyruvaldehyde (32 U·mg−1) in the oxidative and reductive reaction, respectively. AdhA has an optimal activity at 90 °C, at which temperature it has a half life of 22.5 h. The expression of the adhA gene in P. furiosus was demonstrated by activity measurements and immunoblot analysis of cell extracts. A role of this novel type of archaeal alcohol dehydrogenase in carbohydrate fermentation is discussed.
Characterization of a new brain‐specific isoform of the EWS oncoprotein
Authors: Melot Thomas , Dauphinot Luce , Sévenet Nicolas , Radvanyi François , Delattre Olivier 
Published: March 2003

EWS and related TAFII68 and TLS/FUS genes are fused with different genes encoding transcription factors in various human cancers. The products of these genes have the ability to bind RNA and have been shown to be part of splicing and transcription complexes. We show that the EWS, TAFII68 and TLS/FUS proteins are expressed to various levels in all adult murine tissues. We characterize a new isoform of EWS that is specifically expressed in the central nervous system, in both mice and humans. It is shown to be related to a splice variant which includes a new 18‐bp exon, termed 4′, between exon 4 and 5. The detection of this isoform in spontaneously differentiating SH‐SY5Y neuroblastoma cells and in nerve growth factor‐induced PC12 cells further links this isoform to neural differentiation. RT‐PCR experiments indicate that the level of expression of the brain‐specific EWS isoform is stable during brain development whereas that of the ubiquitous EWS isoform decreases during this period. The two isoforms show a parallel decrease in expression after birth. The 4′ exon is not detected in tumour‐specific EWS fusion transcripts, suggesting that its presence may impair their oncogenic properties. Interestingly, sequences of the 4′ exon and flanking regions show remarkable similarities to that of the neural‐specific c‐src exon, suggesting common mechanisms for the alternative splicing of these exons. The phylogenetic conservation and relationship to neural differentiation strongly suggests an important functional role for this exon.
Effects of UV‐B Radiation on Anti‐predator Behavior in Three Species of Amphibians
Authors: Kats Lee B. , Kiesecker Joseph M. , Chivers Douglas P. , Blaustein Andrew R. 
Published: March 2003

AbstractUltraviolet radiation has been suggested as a possible contributing cause of amphibian declines around the world. Both laboratory and field studies have demonstrated that exposure to ultraviolet radiation can lead to increased mortality of developing amphibians. Virtually no studies have examined the sub‐lethal effects of ultraviolet on amphibian behavior. In this study, we examine the anti‐predator behavior of three species of amphibians after short‐term exposure to ultraviolet‐B radiation. Toad (Bufo boreas) juveniles that had been exposed to ultraviolet radiation did not respond to chemical extracts from conspecifics and heterospecifics as much as juveniles that had not been exposed. Both newt larvae (Taricha granulosa) that had been exposed to ultraviolet radiation and those that had not been exposed responded to chemical cues from conspecific predators by increasing the amount of time spent in shelter. Frog tadpoles (Rana cascadae) that had been exposed to ultraviolet radiation did not reduce their movement in response to chemical cues from predators as much as tadpoles that had not been exposed. These results indicate that ultraviolet exposure may have important sub‐lethal effects in amphibians that could adversely effect their fitness.
Burrow Use and the Influence of Ectoparasites in Brants' Whistling RatParotomys brantsii
Authors: Roper T. J. , Jackson T. P. , Conradt L. , Bennett N. C. 
Published: March 2003

AbstractIn Brants' whistling rat,Parotomys brantsii, single animals inhabit unusually complex burrow systems containing several nest chambers. We investigated burrow use and examined the effect of ectoparasites on choice of alternative nest chambers by radiotelemetrically monitoring the nocturnal sleeping locations of individual whistling rats, before and after treating them to remove ectoparasites. Prior to treatment, animals used several different nest chambers within a single burrow, moving from one chamber to another every 1.6 d on average, and most individuals also slept in more than one burrow. Anti‐parasite treatment reduced the rate at which animals switched from one nest chamber to another within a burrow. Screening of a separate sample of animals for ectoparasites revealed that they were infested with fleas, mainlyXenopsylla eridos. We suggest that by switching periodically from one nest chamber to another, whistling rats reduce the rate at which ectoparasites, especially fleas, accumulate.
Behaviour is not Reliably Inferred from End‐Product Structure in Caddisflies
Authors: Stuart Alison E. , Currie Douglas C. 
Published: March 2003

AbstractMany animals engage in elaborate behavioural sequences in order to build structures. The ‘end‐products’ (e.g., nests of birds, cases of caddisflies) of these behaviours have occasionally been used either to infer details of building behaviour or to infer that structures similar in appearance are constructed by similar behavioural sequences. However, behavioural information can be extrapolated from end‐products only if there is congruence between the end‐product structure and the animal's movements. Case building behaviour was studied in caddisflies (Trichoptera) to examine the relationship between end‐products and behaviour. We found examples of taxa that built similar structures using different behavioural patterns, and taxa that built different structures using similar behaviours, regardless of whether these taxa were closely or distantly related. These findings question the reliability of behavioural inferences based solely on details of their associated end‐products and suggest that end‐product structure should be removed from the definition of animal behaviour.
Proximate Determinants of Reproductive Skew in Polygyne Colonies of the AntFormica fusca
Authors: Hannonen Minttumaaria , Sundström Liselotte 
Published: March 2003

AbstractUnderstanding the determinants of reproductive skew (the partitioning of reproduction among co‐breeding individuals) is one of the major questions in social evolution. In ants, multiple‐queen nests are common and reproductive skew among queens has been shown to vary tremendously both within and between species. Proximate determinants of skew may be related to both queen and worker behaviour. Queens may attempt to change their reproductive share through dominance interactions, egg eating and by changing individual fecundity. Conversely, workers are in a position to regulate the reproductive output of queens when rearing the brood. This paper investigates queen behaviour at the onset of egg laying and the effect of queen fecundity and worker behaviour on brood development and reproductive shares of multiple queens in the antFormica fusca. The study was conducted in two‐queen laboratory colonies where the queens produced only worker offspring. The results show that in this species reproductive apportionment among queens is not based on dominance behaviour and aggression, but rather on differences in queen fecundity. We also show that, although the queen fecundity at the onset of brood rearing is a good indicator of her final reproductive output, changes in brood composition occur during brood development. Our results highlight the importance of queen fecundity as a major determinant of her reproductive success. They furthermore suggest that in highly derived polygyne species, such as theFormicaants, direct interactions as a means for gaining reproductive dominance have lost their importance.
Testing Functional Hypotheses for the Behavior of Resident Pine Voles,Microtus pinetorum, Toward Non‐Residents
Authors: Back Shasta R. , Beeler Lisa A. , Schaefer Robert L. , Solomon Nancy G. 
Published: March 2003

AbstractMembers of a social group should attempt to maximize their fitness by maintaining an optimal group composition. Allowing an immigrant into the group may be beneficial or costly depending on the characteristics of the immigrant as well as the composition of the group. Therefore, we examined behavioral interactions between pine voles to test three functional hypotheses proposed to explain behavior of residents toward non‐residents: the resource defense, mate defense, and benefit of extra‐pair copulation hypotheses. To test these, we examined the effects of age, sexual experience and sex of non‐residents as well as the effects of sex of residents on the behavior of residents. Neither male nor female residents showed affiliative behavior toward non‐residents. Residents were more aggressive toward non‐residents than vice versa. The frequency of same‐sex aggression was greater than opposite‐sex aggression for male residents and this aggression was directed at adult male non‐residents to a greater degree than at subadult males. Resident males were least aggressive toward adult females. We found no differences in the behavior of females toward subadults, sexually naive adult non‐residents or sexually experienced adult non‐residents. Females also displayed similar amounts of aggression toward male and female non‐residents. Therefore, for males, aggression may function in defense of a mate while for females, aggression functions in resource defense. For both sexes, aggression is likely to play a role in the regulation of group composition.
Behavioral Analysis of Social Effects on the Problem‐Solving Ability in the House Mouse
Authors: Valsecchi Paola , Bosellini Ilaria , Sabatini Francesca , Mainardi Marisa , Fiorito Graziano 
Published: March 2003

AbstractThe effects of the social context on the problem‐solving ability in the house mouse was evaluated by means of a puzzle box containing food, which could be opened by rotating a revolving door. The aim of the study was to clarify which mechanisms of social learning promote the acquisition of this complex motor skill. Young mice were exposed to the puzzle box in the presence of (i) demonstrators opening of the puzzle box; (ii) adults unable to open the puzzle box; and (iii) adults confined in one part of the cage and not manipulating the puzzle box. Results of the detailed analysis of the sequence of behaviors showed that (i) young mice successful in opening the puzzle box did not copy the sequence of actions performed by demonstrators; and (ii) the presence of adult conspecifics in proximity of the problem apparatus increased the rate of success of young mice. Results suggest that trial‐and‐error learning, social exposure and stimulus enhancement all play a role in the acquisition of the opening ability.
Variation of RAMS markers within the intersterility groups of Heterobasidion annosum in Europe
Authors: Vainio E. J. , Hantula J. 
Published: March 2003

SummaryRandom amplified microsatellite (RAMS) markers were used for the analysis of genetic variation within and among the intersterility groups of Heterobasidion annosum. Isolates from seven European countries were used, and the analysis of 77 markers revealed banding patterns with several markers unique to intersterility (IS) groups S, P and F. The highest number of polymorphic markers and the lowest number of fixed markers was observed within IS group P. In addition, a low level of geographic differentiation was observed within IS groups S and P by amova analysis.
Simultaneous analyses of chromosomes in root meristems and of the biochemical status of needle tissues of three different clones of Norway spruce trees challenged with moderate ozone levels
Authors: Wonisch A. , Muller M. , Tausz M. , Soja G. , Grill D. 
Published: March 2003

SummaryBiochemical effects of both low and high ozone impact in long‐term and short‐term experiments are well investigated and documented; however, short‐term treatments with moderate ozone levels have revealed divergent information concerning the biochemistry of needle tissues. Damage to the meristems of spruce trees have been found for several ozone treatments, in the form of an enhanced number of chromosomal aberrations, which appeared to be persistent for up to 2 years after the ozone challenge. One of the main aims of the present study was to determine whether a moderate ozone concentration is able to induce damage in needle biochemistry and/or only in the genetic material of root meristems. In the experiment three different clones of Norway spruce trees (Picea abies) were challenged with moderate ozone concentrations (up to 80 nl/l) for 11 weeks in greenhouses. Simultaneous investigations of root tip meristematic cells and the biochemical status of needle tissues regarding antioxidants and pigments were performed at two different sampling times: directly after the ozone treatment and 1 year later. Ozone effects in needles were absent both at the end of the fumigation and also after 1 year, but different clonal behaviour was found. Effect of ozone on chromosomal aberration rates in root tip meristems were observed and also the types of persisting chromosomal aberrations changed within the time course and within the different clones.
Cultural characteristics and pathogenicity of Melanconium juglandinum
Authors: Belisario A. 
Published: March 2003

SummaryCultural characteristics and pathogenicity of Melanconium juglandinum, the agent of the black pustular dieback of Juglans spp. in Europe were investigated. Melanconium juglandinum was consistently isolated from diseased twigs and branches of Persian (English) walnut trees (Juglans regia) in Central Italian Apennine valleys. In growth and conidia germination tests, the fungus was shown to be active within a broad range of temperatures (5–30°C), with the optimum being between 20 and 30°C. Monthly artificial inoculations performed over a period of 2 years with mycelial plugs on 2‐year‐old seedlings of Persian (English) walnut developed symptoms within 15 days with maximum canker length occurring when inoculation was carried out between June and August. Koch's postulates were fulfilled and M. juglandinum was proved to be a virulent pathogen.
Genetic variability of the ‘bark canker resistance’ character in several natural provenances of Cupressus sempervirens
Authors: Santini A. , Donardo V. 
Published: March 2003

SummarySeveral Aegean (Greece) and Anatolian (Turkey) cypress provenances were studied for resistance variability to bark canker, a disease caused by the fungal pathogen Seiridium cardinale. The investigation also examined whether the low disease rate within the natural area of cypress was due to genetic or geographic‐climatic reasons. Results demonstrated strong variability for the ‘bark canker resistance’ character, in particular for trees within families. As trees from the provenances studied were not found to have genetic superiority for bark canker resistance, the above‐mentioned low disease rate could be due to geographic‐climatic barriers that inhibit the development of the fungus or its ability to infect the host. Several half‐sib progenies exhibited high resistance, suggesting that this character is totally inherited through the maternal line. Should this finding be confirmed by further research, it would facilitate the task of genetic improvement for resistance, allowing progenies of resistant trees to be obtained.
The aggressiveness of Sphaeropsis sapinea on Austrian pine varies with isolate group and site of infection
Authors: Blodgett J. T. , Bonello P. 
Published: March 2003

SummaryThe aggressiveness of the A and B isolate groups (morphotypes) of Sphaeropsis sapinea on shoot tips and lower stems of Austrian pine (Pinus nigra) was compared. The distinct differences in aggressiveness between the two S. sapinea groups, previously reported for other conifers, are confirmed for Austrian pine. However, the relative aggressiveness of the B group isolate varied by site of infection. Although the B group isolate of S. sapinea was not aggressive on shoot tips of Austrian pine, it was aggressive on stems of this host.
Differences in composition of endophytic mycobiota in twigs and leaves of healthy and declining Quercus species in Italy
Authors: Ragazzi A. , Moricca S. , Capretti P. , Dellavalle I. , Turco E. 
Published: March 2003

SummaryThe composition of the endophytic fungal assemblages in Quercus cerris, Q. pubescens and Q. robur, three oak species most susceptible to decline, was investigated in Fagarè (Padova), Ulignano (Pisa), and Radda in Chianti (Firenze). The endophytic assemblages were studied as a function of health status of the whole tree and of twigs and leaves. The effect of station altitude was tested on Q. cerris. Samples were gathered from healthy and declining trees. In April (bud opening time) 20 twigs and 10 leaves were collected from each tree. Fungi were isolated from twig segments and leaf portions. A total of 23 fungal genera with 27 different species were isolated, in addition to a few sterile mycelia. Eleven species were found to be common to all three oak species, while other species were found only on one oak species, suggesting host specificity. Among the fungal species isolated, some were known to be pathogenic (Apiognomonia quercina, Colpoma quercinum, Diplodia mutila, Phomopsis quercina). The colonization frequency (CF) of pathogenic species varied between 0.9% for A. quercina in Q. cerris and 60.2% for P. quercina in Q. robur. Analysis of variance showed a statistically significant difference among the oak species tested. The CF was higher in declining trees in comparison with healthy trees, and also in twigs vs. leaves. The CF was found to be higher for Q. cerris trees growing at sea level as compared with those situated at an elevation of 350–400 m. In stands where, on account of particular ecological conditions, pathogenic behaviour is displayed simultaneously by more than one endophytic fungal species, trees accentuate their decline.
Stress and adaptation: Preparation for successful retirement
Authors: Lo Ruth , Brown Ron 
Published: March 2003

ABSTRACTRetirement from work can present a significant adjustment challenge for the older population financially, socially and emotionally. Retirement has been identified as a significantly stressful event. Work provides both a structured activity within a regular time frame and a sense of purpose and daily meaning. Energy is channelled into intellectual, creative, and/or physical tasks that offer a sense of satisfaction when they are completed. The planning for retirement is associated with successful adaptation. A realization of the potential and rewards of retirement will also facilitate this adaptation.
Suicide prevention: A public health approach
Authors: Cantor Christopher H. , Baume Pierre J. M. 
Published: March 2003

ABSTRACTThis article proposes a model for developing a national or regional suicide prevention strategy. Suicide is examined from the perspectives of stress, coping behaviours, lethality and multiple causation. Public health concepts of primary, secondary and tertiary prevention are applied to suicide with minor modifications. This exercise facilitates clarity with respect to planning strategies. Conceptual clarity may improve prospects for success but ultimately evaluation will elucidate the outcome.