bluuebunny/crossref_metadata_2025 huggingface dataset:
Genetic Engineering of the Biosynthesis of Glycinebetaine Enhances Photosynthesis against High Temperature Stress in Transgenic Tobacco Plants
Authors: Yang Xinghong , Liang Zheng , Lu Congming
Published: July 2005

Genetically engineered tobacco (Nicotiana tabacum) with the ability to synthesis glycinebetaine was established by introducing the BADH gene for betaine aldehyde dehydrogenase from spinach (Spinacia oleracea). The genetic engineering enabled the plants to accumulate glycinebetaine mainly in chloroplasts and resulted in enhanced tolerance to high temperature stress during growth of young seedlings. Moreover, CO2 assimilation of transgenic plants was significantly more tolerant to high temperatures than that of wild-type plants. The analyses of chlorophyll fluorescence and the activation of Rubisco indicated that the enhancement of photosynthesis to high temperatures was not related to the function of photosystem II but to the Rubisco activase-mediated activation of Rubisco. Western-blotting analyses showed that high temperature stress led to the association of Rubisco activase with the thylakoid membranes from the stroma fractions. However, such an association was much more pronounced in wild-type plants than in transgenic plants. The results in this study suggest that under high temperature stress, glycinebetaine maintains the activation of Rubisco by preventing the sequestration of Rubisco activase to the thylakoid membranes from the soluble stroma fractions and thus enhances the tolerance of CO2 assimilation to high temperature stress. The results seem to suggest that engineering of the biosynthesis of glycinebetaine by transformation with the BADH gene might be an effective method for enhancing high temperature tolerance of plants.
Ethylene Inhibits Abscisic Acid-Induced Stomatal Closure in Arabidopsis
Authors: Tanaka Yoko , Sano Toshio , Tamaoki Masanori , Nakajima Nobuyoshi , Kondo Noriaki , Hasezawa Seiichiro
Published: July 2005

To examine the cross talk between the abscisic acid (ABA) and ethylene signal transduction pathways, signaling events during ABA-induced stomatal closure were examined in Arabidopsis (Arabidopsis thaliana) wild-type plants, in an ethylene-overproducing mutant (eto1-1), and in two ethylene-insensitive mutants (etr1-1 and ein3-1). Using isolated epidermal peels, stomata of wild-type plants were found to close within a few minutes in response to ABA, whereas stomata of the eto1-1 mutant showed a similar but less sensitive ABA response. In addition, ABA-induced stomatal closure could be inhibited by application of ethylene or the ethylene precursor 1-aminocyclopropane-1-carboxylic acid (ACC). In contrast, stomata of the etr1-1 and ein3-1 mutants were able to close in response to concomitant ABA and ACC application, although to a lesser extent than in wild-type plants. Moreover, expression of the ABA-induced gene RAB18 was reduced following ACC application. These results indicate that ethylene delays stomatal closure by inhibiting the ABA signaling pathway. The same inhibitive effects of ethylene on stomatal closure were observed in ABA-irrigated plants and the plants in drought condition. Furthermore, upon drought stress, the rate of transpiration was greater in eto1-1 and wild-type plants exposed to ethylene than in untreated wild-type control plants, indicating that the inhibitive effects of ethylene on ABA-induced stomatal closure were also observed in planta.
Light Enables a Very High Efficiency of Carbon Storage in Developing Embryos of Rapeseed
Authors: Goffman Fernando D. , Alonso Ana P. , Schwender Jörg , Shachar-Hill Yair , Ohlrogge John B.
Published: July 2005

The conversion of photosynthate to seed storage reserves is crucial to plant fitness and agricultural production, yet quantitative information about the efficiency of this process is lacking. To measure metabolic efficiency in developing seeds, rapeseed (Brassica napus) embryos were cultured in media in which all carbon sources were [U-14C]-labeled and their conversion into CO2, oil, protein, and other biomass was determined. The conversion efficiency of the supplied carbon into seed storage reserves was very high. When provided with 0, 50, or 150 μmol m−2 s−1 light, the proportion of carbon taken up by embryos that was recovered in biomass was 60% to 64%, 77% to 86%, and 85% to 95%, respectively. Light not only improved the efficiency of carbon storage, but also increased the growth rate, the proportion of 14C recovered in oil relative to protein, and the fixation of external 14CO2 into biomass. Embryos grown at 50 μmol m−2 s−1 in the presence of 5 μm 1,1-dimethyl-3-(3,4-dichlorophenyl) urea (an inhibitor of photosystem II) were reduced in total biomass and oil synthesis by 3.2-fold and 2.8-fold, respectively, to the levels observed in the dark. To explore if the reduced growth and carbon conversion efficiency in dark were related to oxygen supplied by photosystem II, embryos and siliques were cultured with increased oxygen. The carbon conversion efficiency of embryos remained unchanged when oxygen levels were increased 3-fold. Increasing the O2 levels surrounding siliques from 21% to 60% did not increase oil synthesis rates either at 1,000 μmol m−2 s−1 or in the dark. We conclude that light increases the growth, efficiency of carbon storage, and oil synthesis in developing rapeseed embryos primarily by providing reductant and/or ATP.
Functional Analysis of the Pyrimidine de Novo Synthesis Pathway in Solanaceous Species
Authors: Schröder Michael , Giermann Norbert , Zrenner Rita
Published: July 2005

Pyrimidines are particularly important in dividing tissues as building blocks for nucleic acids, but they are equally important for many biochemical processes, including sucrose and cell wall polysaccharide metabolism. In recent years, the molecular organization of nucleotide biosynthesis in plants has been analyzed. Here, we present a functional analysis of the pyrimidine de novo synthesis pathway. Each step in the pathway was investigated using transgenic plants with reduced expression of the corresponding gene to identify controlling steps and gain insights into the phenotypic and metabolic consequences. Inhibition of expression of 80% based on steady-state mRNA level did not lead to visible phenotypes. Stepwise reduction of protein abundance of Asp transcarbamoylase or dihydro orotase resulted in a corresponding inhibition of growth. This was not accompanied by pleiotropic effects or by changes in the developmental program. A more detailed metabolite analysis revealed slightly different responses in roots and shoots of plants with decreased abundance of proteins involved in pyrimidine de novo synthesis. Whereas in leaves the nucleotide and amino acid levels were changed only in the very strong inhibited plants, the roots show a transient increase of these metabolites in intermediate plants followed by a decrease in the strong inhibited plants. Growth analysis revealed that elongation rates and number of organs per plant were reduced, without large changes in the average cell size. It is concluded that reduced pyrimidine de novo synthesis is compensated for by reduction in growth rates, and the remaining nucleotide pools are sufficient for running basic metabolic processes.
Characterization of Vacuolar Transport of the Endogenous Alkaloid Berberine in Coptis japonica
Authors: Otani Mihoko , Shitan Nobukazu , Sakai Kyoko , Martinoia Enrico , Sato Fumihiko , Yazaki Kazufumi
Published: July 2005

Alkaloids comprise one of the largest groups of plant secondary metabolites. Many of them exhibit strong biological activities, and, in most cases, they are accumulated in the central vacuole of alkaloid-producing plants after synthesis. However, the mechanisms involved in alkaloid transport across the tonoplast are only poorly understood. In this study, we analyzed the vacuolar transport mechanism of an isoquinoline alkaloid, berberine, which is produced and accumulated in the vacuole of cultured cells of Coptis japonica. The characterization of berberine transport using intact vacuoles and a tonoplast vesicle system showed that berberine uptake was stimulated by Mg/ATP, as well as GTP, CTP, UTP, and Mg/pyrophosphate. Berberine uptake was strongly inhibited by NH4+ and bafilomycin A1, while vanadate, which is commonly used to inhibit ATP-binding cassette transporters, had only a slight effect, which suggests the presence of a typical secondary transport mechanism. This is contrary to the situation in the plasma membrane of this plant cell, where the ATP-binding cassette transporter is involved in berberine transport. Model experiments with liposomes demonstrated that an ion-trap mechanism was hardly implicated in berberine transport. Further studies suggested that berberine was transported across the tonoplast via an H+/berberine antiporter, which has a Km value of 43.7 μm for berberine. Competition experiments using various berberine analogs, as well as other classes of alkaloids, revealed that this transporter is fairly specific, but not exclusive, for berberine.
The Evolutionarily Conserved TOUGH Protein Is Required for Proper Development ofArabidopsis thaliana
Authors: Calderon-Villalobos Luz I.A. , Kuhnle Carola , Dohmann Esther M.N. , Li Hanbing , Bevan Mike , Schwechheimer Claus
Published: July 2005

In this study, we characterize the evolutionarily conserved TOUGH (TGH) protein as a novel regulator required for Arabidopsis thaliana development. We initially identified TGH as a yeast two-hybrid system interactor of the transcription initiation factor TATA-box binding protein 2. TGH has apparent orthologs in all eukaryotic model organisms with the exception of the budding yeast Saccharomyces cerevisiae. TGH contains domains with strong similarity to G-patch and SWAP domains, protein domains that are characteristic of RNA binding and processing proteins. Furthermore, TGH colocalizes with the splicing regulator SRp34 to subnuclear particles. We therefore propose that TGH plays a role in RNA binding or processing. Arabidopsis tgh mutants display developmental defects, including reduced plant height, polycotyly, and reduced vascularization. We found TGH expression to be increased in the amp1-1 mutant, which is similar to tgh mutants with respect to polycotyly and defects in vascular development. Interestingly, we observed a strong genetic interaction between TGH and AMP1 in that tgh-1 amp1-1 double mutants are extremely dwarfed and severely affected in plant development in general and vascular development in particular when compared with the single mutants.
Phytochrome Control of theArabidopsisTranscriptome Anticipates Seedling Exposure to Light
Authors: Mazzella María Agustina , Arana María Verónica , Staneloni Roberto J. , Perelman Susana , Rodriguez Batiller María J. , Muschietti Jorge , Cerdán Pablo D. , Chen Kunhua , Sánchez Rodolfo A. , Zhu Tong , Chory Joanne , Casal Jorge J.
Published: July 2005

Phytochromes mediate a profound developmental shift when dark-grown seedlings are exposed to light. Here, we show that a subset of genes is upregulated in phytochrome B (phyB) mutants even before dark-grown Arabidopsis thaliana seedlings are exposed to light. Most of these genes bear the RY cis motif, which is a binding site of the transcription factor ABSCISIC ACID INSENSITIVE3 (ABI3), and the phyB mutation also enhances ABI3 expression. These changes in transcriptome have physiological consequences, because seedlings of the abi3 mutant showed enhanced responses to pulses of far-red light, whereas ABI3 overexpressers exhibited the opposite pattern. Seedlings of the wild type derived from seeds germinated in full darkness showed enhanced expression of genes bearing the RY cis motif and reduced responses to far-red light. We propose that, via changes in ABI3 expression, light, perceived mainly by phyB in the seed, generates a downstream transdevelopmental phase signal that preconditions the seedling to its most likely environment.
‘Best Practice’ Options for the Legal Recognition of Customary Tenure
Authors: Fitzpatrick Daniel
Published: July 2005

Is there a ‘best practice’ model for the legal recognition of customary tenure? If not, is it possible to identify the circumstances in which a particular model would be most appropriate? This article considers these questions in the light of economic theories of property rights, particularly as illustrated by the World Bank's 2003 land policy report. While these theories have their flaws, the underlying concept of tenure security allows a typological framework for developing legal responses to customary tenure. In particular, this article suggests that the nature and degree of State legal intervention in a customary land system should be determined by reference to the nature and causes of any tenure insecurity. This hypothesis is discussed by reference to a wide variety of legal examples from Africa, Papua New Guinea and the South Pacific. The objective is not to suggest that law determines resource governance outcomes in pluralist normative environments, but to improve the quality of legal interventions in order to assist customary groups to negotiate better forms of tenure security and access to resources.
Establishing Development Orthodoxy: Negotiating Masculinities in the Water Sector
Authors: Laurie Nina
Published: July 2005

Despite important work in development studies on the ‘male bias in the development process’, it is generally recognized that gender and development analyses have been slow to engage with masculinities. Focusing attention on the nexus between identity and globalizing development discourses, this article explores the relationship between masculinities and development through an analysis of the gendering of water paradigms. By analysing the example of the recent Cochabamba water wars in Bolivia, and placing them in historical context, the author explores how gendered representations and language are used to downplay and upgrade particular understandings of modernity as they relate to water management, and examines the mechanisms through which specific gendered identities become associated with the most successful versions of ‘modern’ development.
Signalling, Inequality and the Social Structure
Authors: Ferrer Ana M.
Published: July 2005

This paper proposes a theory of endogenous transmission of social status through signalling in the labour market. A signalling game is analysed, in which education, acting as a signalling good, determines one's position in society. The economy's degree of inequality is shown to be a determinant of whether a society is ‘aristocratic’, where high income is the source of social standing, or ‘meritocratic’, bestowing status on high ability. Each social structure shows a different balance between production efficiency and social factors such as equality or mobility.
ON WEIGHTING AND CONGRUENCE
Authors: Allard Marc W. , Carpenter James M.
Published: July 2005

Abstract —A priori differential weighting of molecular characters is a common methodological practice in molecular phylogenetics and evolution. This has been a largely subjective exercise with few criteria for deciding which characters to down‐weight and how much to do so. A priori differential weighting is conducted to remove heterogeneity from the data sets and to improve the congruence among the informative, and usually more conservative characters. Herein, we test whether congruence is improved with a priori differential weighting by using the incongruence length difference test on a linked genetic data set consisting of 14 mammalian taxa and the 13 protein coding genes of the mitochondrial genome. Weighting by omitting the third codon position did not improve congruence with respect to the equally weighted data, while weighting transversions did improve the congruence between the 13 protein coding genes. Nonetheless, the most parsimonious tree found from transversion weighting did not differ from one using all of the data equally weighted.
Exploring Component Stability Using Life‐Stage Concordance In Sabethine Mosquitoes (Diptera: Culicidae)
Authors: Judd Darlene D.
Published: July 2005

Abstract —Morphological characters from sabethine mosquitoes were coded from larvae, pupae and adults, and life‐stage partitions were evaluated to determine the contribution of each to the topology of a combined cladogram. Initial tests failed to find congruence between characters partitioned by life stage. However, when components from the combined analysis were tested using reduced taxon sets, a high degree of concordance between partitions was observed. A procedure for assessing individual life‐stage contribution is employed, in which exhaustive searches are used to explore all possible arrangements for each of the selected components. Seven of the 10 components examined were able to recover the combined topology with a reduced taxon set. Congruent arrangements of taxa were typically observed for two or more life stages, although partitioned data were less resolved and frequently included aberrant topologies (those not supported by other partitioned or combined reduced taxon tree sets). In addition, none of the partitioned data sets gave robust results for all tests, suggesting that studies which emphasize character data from single life stages may support misleading arrangements of taxa. One component on the combined cladogram was not supported by any of the life‐stage partitions when analysed separately. These results are complementary to “total evidence” approach, and demonstrate that partitions of data are useful for examining suits of characters which may cause some components of the “total
Punctuated Equilibrium or Gradualism in the Lizard Genus Sceloporus? Lost in Plesiograms and a Forest of Trees
Authors: Murphy Robert W. , Lovejoy Nathan R.
Published: July 2005

Abstract
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Conclusions about the rates of evolution among a group of organisms are only are only as sound as the phylogeny upon which the conclusions are based. We re‐evaluated the rates of allozyme evolution amoung lizards of the speciose genus Sceloporus. The initial evaluation was suspect because a modification of the invalid, presence or absence method of data coding was employed in genealogical estimation. We recoded the allozyme data using the locus as the character and observed that the previous best explanation of the data fell within a forest of an estimated 107 trees. Further explorations into the invalidity of the independent alleles model of data coding attributed much, but not all, of the shape of the extremely unlikely, independent alleles tree to the parallel loss of plesiotypic alleles, and not the acquistion of novel alleles resulting from mutations. When the data were more appropriately evaluated using mutation coding, there was no unequivocal evidence for a punctuated equilibrium tempo of evolutionary change.
The Science of Phylogenetic Systematics: Explanation, Prediction, and Test
Authors: Kluge Arnold G.
Published: July 2005

When the concept of homology is operationalized with synapomorphy and tested with character congruence, homology and homoplasy are treated as a complement relation, a and not‐a, respectively. This leaves homoplasy to be defined nominally, something like operational ‘error’ in the inference of homology. In choosing the most severely tested and least disconfirmed cladogram, those errors are minimized, and the power of that cladogram to explain synapomorphies, as inherited from the same common ancestral condition, is correspondingly maximized. Tests of predictions of homoplasy can lead to the elimination of those kinds of error. The complementary relationship between homology and homoplasy is considered one of reciprocal clarification, not epistemological dependence.
Strongest Evidence Revisited
Authors: Salisbury Benjamin A.
Published: July 2005

In response to comments by J. S. Farris (2000, Cladistics 16, 403–410) on the strongest evidence (SE) approach to phylogenetic analysis, I examine the concepts on which it is founded and reevaluate its merits. SE's null model of signal absence in characters is not treated as background knowledge, but as a reference point for evaluating a data set's phylogenetic signal in a tree‐specific manner. In simulation tests, the SE methods perform reasonably well; although parsimony is generally more accurate and less biased than SE, SE is distinctly more accurate in some circumstances. Simulations further indicate that jackknifing is often beneficial in both SE and parsimony analyses. Iterative fixation of splits shows promise as an auxiliary procedure for SE and other methods that weight according to apparent homoplasy.
The Phylogeny of the Gasterosteidae: Combining Behavioral and Morphological Data Sets
Authors: McLennan Deborah A. , Mattern Michelle Y.
Published: July 2005

Genealogical relationships among the five genera of stickleback (Gasterosteidae: Smegmomorpha) fishes were reconstructed based upon 47 behavioral and 89 morphological characters. Phylogenetic systematic analysis of the combined data set produced a single MPT (consistency index of 82.54%) structured (Spinachia(Apeltes‐((Pungitius+Culaea)(Gasterosteus aculeatus+G. wheatlandi)))). When analyzed separately, both behavioral and morphological data sets produced the same tree topology, although the consistency index (excluding uninformative characters) was higher for the behavioral (90.70%) than for the morphological (68.13%) characters. This total evidence analysis provides a highly robust estimate of phylogeny for the sticklebacks and reiterates the importance of discarding a priori biases about behavioral evolution when selecting characters for phylogenetic analysis.
Extrapolating Cladistic Biogeography: A Brief Comment on van Velleret al.(1999, 2000, 2001)
Authors: Ebach Malte C.
Published: July 2005

Cladistic biogeography aims to find congruence (common patterns among area relationships) among taxon‐area cladograms. Not all areagrams are congruent, and ambiguity needs to be either reduced or resolved in order for a common biogeographic pattern to emerge. Recent papers by van Velleret al.(1999,Cladistics15, 393–406; van Velleret al.2000,Cladistics16, 319–345; van Velleret al.2001,Cladistics) suggest that ambiguity is the result of isolation mechanisms other than vicariance. That is, identifying such mechanisms in a monophyletic group or areagram and by combining two or more areagrams using assumptions 0, 1, or 2 may result in common patterns. Under such a hypothesis van Velleret al.(1999, 2000, 2001) suggest that ambiguity is congruent and removal of it decreases explanatory power. Assumption 0 differs in all other approaches as it resolves ambiguity usingtaxonand notarea relationships, contrary to the aims of cladistic biogeography.
Assessing Modes of Speciation: Range Asymmetry and Biogeographical Congruence
Authors: Green Marc D. , van Veller Marco G.P. , Brooks Daniel R.
Published: July 2005

Lynch [1989,in“Speciation and Its Consequences” (D. Otte and J. A. Endler, Eds.), pp. 527–553, Sinauer, Sunderland, MA, proposed a methodology for assessing the frequency of occurrence of various modes of initiating species formation, using a combination of phylogenetic relationships and relative size of geographic ranges for sister species and sister groups. Historical biogeography provides an alternative criterion for assessing modes of species formation. Species whose distributions conform to a general (replicated in multiple clades) pattern of area relationships are deemed to be the result of vicariance (including microvicariance) regardless of the details of current geographic range. Species exhibiting unique biogeographic distributions are the result of peripheral isolates speciation and postspeciation dispersal. Lineage duplications indicate sympatric speciation. An empirical assessment of this alternative approach was performed using the most recent phylogenetic trees and geographical distribution data on the Mesoamerican poeciliid fish comprising the generaXiphophorusandHeterandria. The single area cladogram produced by secondary Brooks Parsimony Analysis indicates 3 vicariant events (accounting for seven extant species and the common ancestor of the northern swordtails, which are not further analyzed) and at least 13 episodes of peripheral isolates speciation. Two of the 10 areas considered in previous analyses are vicariant areas of endemism, 1 is historically unique due to a single episode of peripheral isolates speciation, and the remaining 7 have reticulated histories of speciation. The results corroborate inferences of speciation modes made by Lynch for the same data.
Fishery‐specific differences in the size selectivity and catch of diamond‐ and square‐mesh codends in two Australian penaeid seines
Authors: MACBETH W. G. , BROADHURST M. K. , MILLAR R. B.
Published: July 2005

Abstract  The selectivities and catch compositions of conventional 30‐mm diamond‐mesh codends and a new square‐mesh design made from 20‐mm mesh hung on the bar for river and lagoon penaeid seines in south‐eastern Australia were compared. The square‐mesh design significantly improved the selectivities of the river seine for school prawns, Metapenaeus macleayi (Haswell), and the lagoon seine for greasyback prawns, Metapenaeus bennettae (Racek & Dall), by increasing their carapace length at 50% probability of retention (L50) and by decreasing between‐haul variability in selectivity. The presence of weed reduced the L50 for greasyback prawns caught in the conventional diamond‐mesh codend during the lagoon‐seine experiment. The differences among codend performances are discussed in terms of the differing methods of operation and composition of catches between the seines. These differences highlight the need to develop and manage modifications to improve the selectivity of fishing gears on a fishery‐specific basis.
Estimating the pattern of synchrony in fluctuating populations
Authors: ENGEN STEINAR , LANDE RUSSELL , SÆTHER BERNT‐ERIK , BREGNBALLE THOMAS
Published: July 2005

A central question in population ecology is how to estimate the effects of common environmental noise, e.g. due to large‐scale climate patterns, on the synchrony in population fluctuations over large distances. We show how the environmental variance can be split into components generated by several environmental variables and how these can be estimated from time‐series observations.

With a set of time‐series observations from different locations not necessarily covering the same time span, it is shown how the spatial autocorrelation of the residual variance component, not explained by the covariates and corrected for demographic stochasticity, can be estimated using classical multinormal theory.

Some previous results on spatial scaling in continuous linearized models on log scale are extended to also provide the scaling for the residuals. This is shown to be close to the spatial scaling of the autocorrelation in the environmental noise and only weakly affected by migration.

The logistic model of local population dynamics with the NAO index as the only covariate is fitted to 22 populations of the Continental great cormorant Phalacrorax carbo sinensis. The spatial scale of the environmental noise is estimated to be about 155 km. The NAO index alone accounts for about 10% of the total environmental variance and nearly all of the regional environmental variance (long‐distance environmental autocorrelation).
Torpor patterns of hibernating eastern chipmunks Tamias striatus vary in response to the size and fatty acid composition of food hoards
Authors: MUNRO DANIEL , THOMAS DONALD W. , HUMPHRIES MURRAY M.
Published: July 2005

Many endotherms employ torpor during periods of resource scarcity, but this state of substantially reduced body temperature and metabolism appears to impose significant physiological costs. Accordingly, individuals can be expected to vary the expression of torpor according to the size of their energy reserves.

Although dietary polyunsaturated fatty acids (PUFAs) are important for maintaining the fluidity of membrane phospholipids and depot fats at low body temperatures, they are also prone to autoxidation, which can result in significant somatic damage. Dietary PUFA may thus influence the depth and duration of torpor during hibernation.

We evaluated the hypothesis that both an increase in the size of the burrow food hoard and an elevation of its PUFA composition can cause chipmunks to reduce their use of torpor both by reducing the time spent torpid and by maintaining higher body temperature during torpor.

We provided individual chipmunks with equicaloric natural‐PUFA and high‐PUFA supplements 10 days prior to autumn immergence. We measured seven parameters that characterize the depth and duration of torpor used by hibernating chipmunks using temperature‐sensitive data loggers mounted on neck collars. We compared torpor patterns for the natural‐PUFA, high‐PUFA and control groups at a study site in southern Quebec, Canada. We also compared control animals from Quebec with unsupplemented controls from a more southerly site in Pennsylvania, USA characterized by higher food availability and less severe winters.

Chipmunks provided with natural‐PUFA supplements spent less than half as much time in torpor as control animals at the same study site, and when in torpor they exhibited skin temperatures almost twice as high as controls. Chipmunks provided with high‐PUFA supplements significantly reduced the depth and duration of torpor bouts compared with animals provided with natural‐PUFA supplements. The torpor patterns of unsupplemented chipmunks at the southern site approximated those of natural‐PUFA chipmunks at the main study site.

Our results provide clear evidence that chipmunks adjust the depth and duration of torpor expression according to both the size and the composition of their energy reserves. Furthermore, both the extent and the nutritional form of environmental energy availability are important determinants of the cost and benefits of torpor expression by free‐ranging endotherms.
Comparative changes in adult vs. juvenile survival affecting population trends of African ungulates
Authors: OWEN‐SMITH NORMAN , MASON DARRYL R.
Published: July 2005

Among large mammalian herbivores, juvenile survival tends to vary widely and may thus have a greater influence on population dynamics than the relatively constant survival rates typical of adults. However, previous studies yielding stage‐specific survival rates have been mostly on temperate zone ungulates and in environments lacking large predators.

Annual censuses coupled with assessments of population structure enabled annual survival rates to be estimated for the juvenile, yearling and adult segments of nine ungulate species in South Africa's Kruger National Park. Four of these populations persisted at high abundance after initial increases (zebra, wildebeest, impala and giraffe), while five showed progressive declines during the latter part of the study period (kudu, waterbuck, warthog, sable antelope and tsessebe).

The magnitude of the reduction in adult survival between periods showing contrasting population trends was similar to or greater than the corresponding change in juvenile survival for five of the nine species. Accordingly alterations in population phase, from increasing to stable or stable to declining, were brought about mostly through reduced survival within the adult segment. Elevated predation risk may have been responsible.

Estimates were derived of the relative survival rates of juveniles, yearlings and adult segments associated with zero population growth, and the survival differential between adult males and females, for all nine species. Stage‐specific survival rates appeared dependent on body mass, but with some anomalies. The sex difference in adult survival showed no obvious relation with sexual size dimorphism.

For large mammalian herbivores, assessments of relative elasticities of stage‐specific survival rates on population growth are problematic for several reasons. Sensitivity to corresponding increments in either survival or mortality rates provides a better basis for ecological or adaptive interpretation. Survival rates of adults seem to vary more over multiyear periods compared with mainly annual fluctuations in juvenile survival. More studies are needed on tropical species and in environments retaining large predators to support generalizations about factors influencing ungulate life‐history patterns.
Pharmacokinetics of levofloxacin after single intravenous and repeat oral administration to cats
Authors: ALBARELLOS G. A. , AMBROS L. A. , LANDONI M. F.
Published: July 2005

The pharmacokinetic properties of the fluoroquinolone levofloxacin, were investigated in five cats after single intravenous and repeat oral administration at a daily dose of 10 mg/kg. Levofloxacin serum concentration was analyzed by microbiological assay using Klebsiella pneumoniae ATCC 10031 as test microorganism. Serum levofloxacin disposition after intravenous and oral dosing was best fitted to a bicompartmental and a monocompartmental open models with first‐order elimination, respectively. After intravenous administration, distribution was rapid (t1/2(d) 0.26 ± 0.18 h) and wide as reflected by the steady‐state volume of distribution of 1.75 ± 0.42 L/kg. Drug elimination was slow with a total body clearance of 0.14 ± 0.04 L/h·kg and a t1/2 for this process of 9.31 ± 1.63 h. The mean residence time was of 12.99 ± 2.12 h. After repeat oral administration, absorption half‐life was of 0.18 ± 0.12 h and Tmax of 1.62 ± 0.84 h. The bioavailability was high (86.27 ± 43.73%) with a peak plasma concentration at the steady state of 4.70 ± 0.91 μg/mL. Drug accumulation was not significant after four oral administrations. Estimated efficacy predictors for levofloxacin after either intravenous or oral administration indicate a good profile against bacteria with a MIC value below of 0.5 μg/mL. However, for microorganisms with MIC values of 1 μg/mL it would be efficacious only when administered intravenously.
Lack of mitochondrial DNA divergence between chromosome races of the common shrew, Sorex araneus, in Sweden. Implications for interpreting chromosomal evolution and colonization history
Authors: ANDERSSON ANNA‐CARIN , ALSTRÖM‐RAPAPORT CECILIA , FREDGA KARL
Published: July 2005

The common shrew, Sorex araneus, has one of the most variable karyotypes among mammals, displaying numerous chromosome races throughout its distribution. The six chromosome races present in Sweden can be categorized in two different karyotypic groups, the west and north European karyotypic groups (western and northern). Three races belonging to the western group are considered to have arisen through whole arm reciprocal translocations (WARTs). Race formation through this process requires a bottleneck event. In the present study we sequenced a part of the mitochondrial DNA (mtDNA) genome to investigate molecular differences between the chromosome races in Sweden. We found no mtDNA differentiation between the mainland chromosome races or the karyotypic groups. Genetic variation is as large between populations within a race as between populations among the races or karyotypic groups, suggesting that the karyotypic groups might have originated in a common glacial refugium. The noticeable exception is the Öland race, which shows higher mtDNA diversity compared to the other Swedish races, indicating a divergent origin difficult to explain. Mitochondrial DNA variation in Sweden suggests that most haplotypes arose in situ and that the populations has undergone a rapid size expansion. Altogether, the mtDNA data are in agreement with the WART hypothesis, which still holds as the most plausible variant of karyotype evolution for three of the chromosome races of the common shrew in Sweden.
Fighting an enemy within: cytoplasmic inhibitors of bacterial cysteine proteases
Authors: Potempa Jan , Golonka Ewa , Filipek Renata , Shaw Lindsey N.
Published: July 2005

The genes encoding secreted, broad‐spectrum activity cysteine proteases of Staphylococcus spp. (staphopains) and Streptococcus pyogenes (streptopain, SpeB) are genetically linked to genes encoding cytoplasmic inhibitors. While staphopain inhibitors have lipocalin‐like folds, streptopain is inhibited by a protein bearing the scaffold of the enzyme profragment. Bioinformatic analysis of other prokaryotic genomes has revealed that two more species may utilize this same genetic arrangement to control streptopain‐like proteases with lipocalin‐like inhibitors, while three other species may employ a C‐terminally located domain that resembles the profragment. This apparently represents a novel system that bacteria use to control the intracellular activity of their proteases.
Slow Export of Photoassimilate from Stay‐green Leaves during Late Grain‐Filling Stage in Hybrid Winter Wheat (Triticum aestivum L.)
Authors: Gong Y.‐H. , Zhang J. , Gao J.‐F. , Lu J.‐Y. , Wang J.‐R.
Published: July 2005

Hybrid winter wheat (cv. XN901) shows a strong hybrid vigor in terms of yield potential and its leaves and stems stay green when its kernels reach maturity. Much of its pre‐stored carbon reserve is left unused in its stems and leaves. In this study, photosynthesis and translocation of carbon assimilates of the hybrid wheat were investigated at its late grain‐filling stage. Feeding labelled 14CO2 to flag leaves of XN901 showed that its export to grains was much slower than that of an ordinary cultivar (Shaan 229) that is currently used in production. Within 24 h of labelling, Shaan 229 and XN901 exported 59 % and 40 %, respectively, of the 14C from their flag leaves. At the sink side, 52.1 % of the fed 14C in Shaan 229 was exported to its grains within the first 24 h while XN901 deposited only 15.8 % of the fed 14C in the grains at the same period. Photosynthetic rates and chlorophyll contents in the flag leaves declined much more slowly in XN901 than in Shaan 229 during the late grain‐filling stage. Hybrid wheat XN901 also had a longer grain‐filling period (6 days longer), higher grain yield (15 % more), but lower harvest index (19 % less) than Shaan 229. Its grain‐filling rate was lower but declined more slowly at the late grain‐filling stage than that of Shaan 229. Results indicate that the strong hybrid vigour of XN901 leads to an unfavourably delayed senescence which results in the much unused carbon reserve in its straws. Raising harvest index should be the key aim to materialize its yield potential.
The Occurrence of Phytoplasmas in Apple Trees Showing Branch Twisting
Authors: Fránová J.
Published: July 2005

Apple trees showing malformation of branches were found at different locations in the Czech Republic. Ultrathin sections of tissues from diseased trees showed the presence of pleomorphic bodies resembling phytoplasma. Nested‐polymerase chain reaction (PCR) assays with primers amplifying16S–23S ribosomal RNA (rRNA) sequences specific for phytoplasma and the subsequent restriction fragment length polymorphism (RFLP) analyses allowed to classify the detected phytoplasmas in the aster yellows group, subgroup 16SrI‐C in 12 trees, single (11 plants) or mixed with phytoplasma belonging to subgroup 16SrI‐B (1 plant). Phytoplasma of apple proliferation group (16SrX‐A subgroup) were identified in cv. Matčino. Apple tree cv. Přeštické růžové was infected by phytoplasma of the 16SrX‐A and 16SrI‐B subgroups. No phytoplasmas were detected in asymptomatic apple trees.
AFLP Analysis of Trichoderma spp. from India Compared with Sequence and Morphological‐based Diagnostics
Authors: Buhariwalla H. K. , Srilakshmi P. , Kannan S. , Kanchi R. S. , Chandra S. , Satyaprasad K. , Waliyar F. , Thakur R. P. , Crouch J. H.
Published: July 2005

Trichoderma species offer considerable potential for controlling aflatoxin contamination in groundnut and other crops. Initial classification of 48 Trichoderma isolates, derived from four different groundnut cultivation sites in India was based on alignment of 28S rDNA sequences to GenBank sequences of ex‐type strains. This was found to be substantially more reliable than our routine morphological characterization, but did not provide a comprehensive diagnostic solution, as unique single nucleotide polymorphism (SNP) haplotypes could not be identified for all species. However, all the Trichoderma isolates could be readily distinguished by amplified fragment length polymorphism (AFLP) analysis, based on six primer pair combinations, which generated 234 polymorphic bands. In addition, individual AFLP bands were identified which differentiate closely related species. Similarly, AFLP bands were identified that correlated with different types of antagonism to Aspergillus flavus. The implications of these results for the development of simple polymerase chain reaction (PCR)‐based diagnostic assays for antagonistic isolates of Trichoderma is discussed.
A Simple Method of Mass Inoculation of Rice Effective for Both Pathovars ofXanthomonas oryzae, and the Construction of Comparable Sets of Host cDNA Libraries Spanning Early Stages of Bacterial Leaf Blight and Bacterial Leaf Streak
Authors: Niño‐Liu D. O. , Darnielle L. , Bogdanove A. J.
Published: July 2005

Xanthomonas oryzaepv.oryzae(Xoo) andX. oryzaepv.oryzicola(Xoc) are important bacterial pathogens of rice (Oryza sativa). Despite being very closely related, they infect in different ways and cause distinct diseases. Xoo invades the xylem to cause bacterial blight, whereas Xoc colonizes the leaf mesophyll to cause bacterial leaf streak. As the modes of infection of these two pathogens are different, traditional methods of inoculation effective for Xoo are not effective for Xoc and vice versa. We discovered that dipping plants in bacterial suspension is an effective inoculation method both for Xoo and Xoc and can be used to achieve uniform and synchronized infection of multiple plants. Using this method, comparable sets of rice Gateway®cDNA libraries spanning five time points in the early stages of bacterial blight and bacterial leaf streak were constructed. Prepared under identical conditions, the libraries are ideal for probing differential rice transcription during development of the diseases. Furthermore, by capturing transcripts expressed in response to these unique sources of biotic stress, the libraries are likely to contain cDNA clones not available elsewhere.
On the Effects of a Chronic Deoxynivalenol Intoxication on Performance, Haematological and Serum Parameters of Pigs when Diets are Offered Either for Ad Libitum Consumption or Fed Restrictively
Authors: Goyarts T. , Dänicke S. , Rothkötter H.‐J. , Spilke J. , Tiemann U. , Schollenberger M.
Published: July 2005

Wheat infected naturally with Fusarium, contaminated mainly with deoxynivalenol (DON) (16.6 mg DON/kg), was added to a total constant wheat content of 400 g/kg diet. To distinguish between differences in feed intake and specific effects of the DON contaminated diet, control and DON contaminated feed was administered for 11 weeks under ad libitum and restrictive feeding conditions to 48 pigs of both sexes, which were randomly divided into four groups (n = 12 per group). Feed intake was 2.90 kg/day, live weight gain 987 g/day and feed to gain ratio 2.77 kg/kg for the ad libitum fed control group. The group fed DON contaminated wheat ad libitum significantly consumed 15% less feed and gained 13% less live weight, while the feed to gain ratio was unaffected. Moreover, it was concluded that the lower growth performance by DON contaminated feed resulted mainly from the lower voluntary feed intake, because there were no differences in live weight gain between the groups with the restrictive feeding regimen. On the contrary, metabolizable energy, nitrogen retention digestibility of organic matter, crude protein, crude fat and crude fibre were significantly increased by 3, 10, 3, 6, 9 and 20% in the DON group respectively. Animals fed DON contaminated diets needed more time to consume the restrictive ration than the control group. For example in the first hour after feeding 85% of the control pigs had consumed all feed, but only 39% of the DON group had. There were only few differences in haematological and serum parameters, which were characterized by a high variation between individuals. DON and IgA concentrations in serum were significantly influenced by DON exposure.
The Effects of Probiotic and Mannanoligosaccharide on some Haematological and Immunological Parameters in Turkeys
Authors: ÇEti̇n N. , Güçlü B. K. , ÇEti̇n E.
Published: July 2005

The study was conducted to investigate the effects of mannanoligosaccharide (MOS) and probiotic supplementation on haematological and immunological parameters in turkeys. A total of 72, 15‐day‐oldwhite hybrid converter turkey poults were used in this study. Poults were assigned into three groups, each group consisted of six poults and the trial was repeated four times. The control group was fed a basal diet without supplemented probiotic and MOS, and treatment groups were fed either 1 g/kg MOS or probiotic added diets. At the end of the 15‐week treatment period, samples of blood were collected to determine immunological and haematological values. The comparison among the groups showed that both the probiotic and MOS supplementation resulted in significant increases (P < 0.05) in the serum IgG and IgM levels, and significant decreases (P < 0.05) in the peripheral blood T lymphocyte percentage compared with those of the control group. Mean serum IgG level (7.06 g/l) was significantly higher (P < 0.05) in poults supplemented with probiotic compared with MOS (6.76 g/l). It was observed that the probiotic supplementation caused statistically significant increases (P < 0.05) in the erythrocyte count, haemoglobin concentration and haematocrit values, but MOS supplementation did not have a significant effect (P > 0.05) on these parameters. Total leucocyte and differential leucocyte counts were not affected by dietary MOS and probiotic supplementation. These results show that MOS or probiotic may elevate IgG and IgM levels in turkey. The MOS and probiotic that enhance immunoglobulin levels will have a more positive effect on growth performance, production and turkeys’ ability to resist disease.
World Assumptions as a measure of meaning in rural road crash victims
Authors: Jeavons Sue , Godber Tim
Published: July 2005

Objective:  To explore the effect of experiencing a road crash on aspects of psychological meaning.

Design:  A 12‐month repeated measures prospective design was used.

Setting:  Data were collected from admissions to a hospital in central Victoria.

Subjects:  Seventy‐two injured road crash victims took part in the study.

Main outcome measures:  Three measures of psychological trauma and the World Assumptions Scale.

Results:  World Assumptions Scale scores did not change significantly over the year, despite improvements in other trauma scores.

Conclusion:  This study does shed some light on the psychological effects of road trauma, but further research is needed to create more sophisticated measures.