Search

Polychlorinated Biphenyls (PCBs) are persistent organic pollutants and have been associated with abnormal liver enzymes and suspected non-alcoholic fatty liver disease (NAFLD), obesity, and the metabolic syndrome in epidemiological studies. In epidemiological surveys of human PCB exposure, PCB 153 has the highest serum levels among PCB congeners. To determine the hepatic effects of PCB 153 in mice, C57BL/6J mice were fed either a control diet (CD) or a high fat diet (HFD) for 12 weeks, with or without PCB 153 co-exposure. The metabolite extracts from mouse livers were analyzed using linear trap quadruple - Fourier transform ion cyclotron resonance mass spectrometer (LTQ-FTICR MS) via direct infusion nano-electrospray ionization (DI-nESI) mass spectrometry. The metabolomics analysis indicated no difference in the metabolic profile between mice fed the control diet with PCB 153 exposure (CD+PCB 153) and mice fed the control diet (CD) without PCB 153 exposure. However, compared with CD group, levels of 10 metabolites were increased and 15 metabolites were reduced in mice fed HFD. Moreover, compared to CD+PCB 153 group, the abundances of 6 metabolites were increased and 18 metabolites were decreased in the mice fed high fat diet with PCB 153 exposure (HFD+PCB 153). Compared with HFD group, the abundances of 2 metabolites were increased and of 12 metabolites were reduced in HFD+PCB 153 group. These observations agree with the histological results and indicate that the metabolic effects of PCB 153 were highly dependent on macronutrient interactions with HFD. Antioxidant depletion is likely to be an important consequence of this interaction, as this metabolic disturbance has previously been implicated in obesity and NAFLD.

Aim Shifts in diet composition, abundance or distribution of native predators can occur as a result of exotic prey introductions. We examined effects of non-native earthworms and anthropogenic landscape disturbance on habitat selection by the American robin (Turdus migratorius), a generalist predator, at landscape and local levels. We also investigated whether robins could act as vectors of spread for earthworm cocoons (egg cases). Location Boreal forest of Alberta, Canada. Methods We conducted robin and earthworm surveys at campgrounds, well pads, roads, pipelines, seismic lines and forest interiors across northern Alberta. At a subset of paired locations that had similar habitats and anthropogenic disturbance levels, we sampled both robins and earthworms. Results Both groups were most likely to occur at campgrounds, well pads and roads. Furthermore, robins were more likely to occur at locations where earthworms were present in our paired local-level surveys. This correlation between robin and earthworm distributions could be due to robins acting as a vector for earthworm spread, rather than robins’ use of earthworms as prey. However, in tests using captive robins, earthworm cocoons did not survive digestion. Main conclusions Robin and earthworm distributions were correlated, likely due to robins’ use of earthworms as prey. These results suggest exotic prey can strongly influence native predators at both landscape and local levels, with shifts in native predator distributions occurring as a result of spatial variability in exotic prey distributions. Although the impacts of ecosystem engineering by earthworms have been previously demonstrated, our study provides evidence that effects of earthworms can also cascade upwards via trophic interactions.

The effects of speech task (conversation versus conversation-repetition) and deep brain stimulation (DBS) on intelligibility in Parkinson’s disease were examined. Speech samples in the two production modes (tasks) were matched by having subjects repeat their own utterance types previously obtained during spontaneously produced conversational speech. Intelligibility measures from listeners were augmented by difficulty ratings. Linguistic context in the experimental protocol was manipulated using the results of a written pre-test and segregation of auditory stimuli by difficulty and length. Comparisons of task and DBS state revealed significant effects of task, DBS, and stimulus length on intelligibility measures of speech. Difficulty ratings tracked accuracy measures. Overall repetition was more intelligible than conversation, especially for shorter stimuli, demonstrating that task demands and spoken context had strong effects on motor speech competence. The adverse effects of DBS on speech intelligibility were observed on conversational but not repeated speech. These results demonstrate a facilitative role of external models provided by repetition in motor speech performance, and a mildly disruptive role of DBS on internally modeled conversational speech.

Exotic earthworms are entering previously uninhabited soils of boreal forests, their invasion largely facilitated through human activities. As ecosystem engineers, earthworms are capable of causing dramatic changes in above- and belowground forest composition, but whether they have the same effects in all forests remains unclear. Forest compositional changes caused by earthworms may be mediated by interactions between earthworms and mycorrhizal fungi. Specifically, tree seedling growth may be altered by the presence of exotic earthworms and their subsequent impact on mycorrhizal fungi. In this study, we investigate the effects of exotic earthworms on ectomycorrhizal colonization and seedling growth of the conifer Picea glauca (white spruce) in gray luvisolic soils from the Boreal Plains. Anecic Lumbricus terrestris and epigeic Dendrobaena octaedra earthworms were added to mesocosms each containing a white spruce seedling in a greenhouse experiment. Impacts on the composition of ectomycorrhizal f...

As Arabidopsis matures it becomes resistant to virulent Pseudomonas syringae pv. tomato (Pst), a defense response known as Age-Related Resistance (ARR). The contribution of two NAC transcription factors (ANAC055 and ANAC092) and jasmonic acid/ethylene (JA/ET) signaling to ARR was examined by comparing Pst growth in wild-type plants, nac mutants, an ANAC092-overexpressing line, lox2, and ein2-1. PDF1.2 expression and anac055anac092 double mutant analysis suggests that ANAC055 and ANAC092 play non-redundant roles in ARR. Additionally, ANAC092 contributes to the initiation of flowering in short day-grown plants. ANAC055 and ANAC092 expression was reduced in partially ARR-defective ein2-1 suggesting that regulation of ANAC055 and ANAC092 by EIN2 contributes to ARR.

Background Several factors contribute to the complexity of pharmacotherapeutic regimens, like the total number of medications to be taken, the number of dosage units to take at a time, dosage frequency, as well as specific directions concerning the administration. The Medication Regimen Complexity Index (MRCI) is a validated instrument developed in English for the measurement of the complexity of a given pharmacotherapeutic regimen. Objectives Translation of the MRCI into German and evaluation of the translated instrument (MRCI-D) in order to make it more easily accessible for use in German practice and research. Methods The process of validation included the translation of the English version to German, back-translation into English, comparison of the back-translated and the original versions, pre-tests, and pilot-testing of the German version by three raters using 20 medication regimens for inpatients. The subsequent psychometric evaluation included the calculation of inter-rater and test–retest reliability, as well as the assessment of convergent validity. Results The number of medications correlated highly and statistically significantly with the MRCI-D score (0.91, P

Posttraumatic cerebral sinus thrombosis is an uncommon disease in children that is rarely seen in the setting of a closed head injury. We report a 6-year-old boy who developed cerebral sinus thrombosis after an apparent minor head injury. The clinical presentation, neuroimaging findings, and treatment strategies are discussed. Serial neurological evaluation and close observation are important, and the decision for anticoagulation should be carefully considered with hematological consultants. Language: en

Many remote islands are degraded as a result of deforestation and browsing of vegetation by introduced goats. Goat eradication is therefore a focus for island restoration, but there are few long-term records of change on islands after eradications. In 1946, three permanent plots were established immediately after goats were eradicated from Great Island (Manawa Tawhi), 60 km from northern New Zealand, and provide a 57-year record of change across a sequence of forest succession. Since 1946, the native and non-native bird communities that disperse 75% of the woody flora have increased from six to eight species and bird-dispersed woody plants in plots have increased from 7 to 11 species. After 1946, palatable trees were recruited in the plots. Unpalatable understorey sedges, present when goats were abundant, have persisted and may impede tree seedling establishment. Of the bird-dispersed woody plant species, 41% occur in the plots compared with 67% of the non-bird-dispersed species. Large-seeded species were unable to germinate away from parents until native pigeons Hemiphaga novaeseelandiae were present during the last decade. Forest succession is a consequence of interactions between the legacy of goat grazing and current disperser communities. Survival of seed-limited rare plants is not guaranteed in these circumstances. Although non-native goats no longer influence succession directly, non-native birds have been and remain important components of the disperser community. Our study supports the view that a whole-ecosystem understanding of the interactions between native and non-native species is needed to predict the consequences of eradications on islands worldwide.

A reappraisal of the conservation status of the indigenous New Zealand vascular plant flora is presented using the 2008 version of the threat classification system developed for the New Zealand Department of Conservation. The list comprises 897 taxa (38% of New Zealand's total indigenous vascular flora) in the following categories: Extinct—6 taxa, Threatened—180 taxa (comprising 91 Nationally Critical taxa, 45 Nationally Endangered, and 44 Nationally Vulnerable), At Risk—651 taxa (comprising 83 Declining, 6 Recovering, 20 Relict, and 542 Naturally Uncommon taxa), 25 taxa listed as either Vagrant (12) or Coloniser (13), and 35 as Data Deficient. A further 171 plants are listed as taxonom ically indeterminate, being those which might warrant further conservation attention once their taxonomic status is clarified. Forty‐four recognised taxa and 26 plants rated as taxonomically indeterminate, and previously considered to be threatened and/or uncommon, are removed from this updated listing. A brief an...

Summary 1 Roads are an important conduit for the spread of invasive species. Road age is a key factor that could influence the susceptibility of roads to invasion as older roads are typically subject to higher cumulative levels of human disturbance and propagule pressure than younger roads. We investigated the effects of road age on the spread of non-native earthworms, which act as ecosystem engineers. 2 We sampled earthworms and habitat variables at 98 roads in the boreal forest of Alberta, Canada, to determine the influence of road age on non-native earthworm occurrence at the landscape level. The extent and rate of local spread were also assessed at seven sites adjacent to old and young roads. Generalized estimating equations and zero-inflated negative binomial regression were used to analyze landscape- and local-level results, respectively. We used our models to create maps that predict the current and potential future extent of earthworms in north-eastern Alberta. 3 Probability of earthworm occurrence and extent of spread increased as road age increased. Areas closer to agriculture and towards the south and west of our study area were also significantly more likely to be invaded by earthworms. 4 Our spread model indicated that approximately 9% of the boreal forest of north-eastern Alberta is likely invaded by earthworms currently. This is projected to increase to 49% of suitable forest habitat over the next 50 years as human development intensifies in this region. 5 Synthesis and applications. Although the effects of roads and linear features are commonly investigated in relation to native species, our results emphasize the importance of considering the impacts of linear feature creation on the spread of invasive species. We demonstrate that road age in particular can be an important factor affecting the spread of invasive species. In the boreal forest, reducing the number of roads being constructed, restricting traffic, and reclaiming temporary roads will be critical to reduce the future extent of earthworm invasions.

Many Anglicans have begun to see the institutions of the Anglican Communion as something of a ‘tortoise’, either because of their halting journey towards gay and lesbian inclusion, or because of the way in which they have only slowly moved towards a clear rejection of such an ‘innovation’. How does the Anglican Communion actually operate in the face of such developments? This article argues that the Instruments of Communion have adopted an ordered approach to the Communion's life – working through legitimate structures both at provincial and Communion level. It sets out some of the main channels through which the Communion has been working – the Windsor Process and the proposal for an Anglican Covenant – and argues in favour of such an ordered approach to life.

Systemic acquired resistance (SAR) is a plant defense response that provides long-lasting, broad-spectrum pathogen resistance to uninfected systemic leaves following an initial localized infection. In Arabidopsis (Arabidopsis thaliana), local infection with virulent or avirulent strains of Pseudomonas syringae pv tomato generates long-distance SAR signals that travel from locally infected to distant leaves through the phloem to establish SAR. In this study, a proteomics approach was used to identify proteins that accumulate in phloem exudates in response to the induction of SAR. To accomplish this, phloem exudates collected from mock-inoculated or SAR-induced leaves of wild-type Columbia-0 plants were subjected to label-free quantitative liquid chromatography-tandem mass spectrometry proteomics. Comparing mock- and SAR-induced phloem exudate proteomes, 16 proteins were enriched in phloem exudates collected from SAR-induced plants, while 46 proteins were suppressed. SAR-related proteins THIOREDOXIN h3, ACYL-COENZYME A-BINDING PROTEIN6, and PATHOGENESIS-RELATED1 were enriched in phloem exudates of SAR-induced plants, demonstrating the strength of this approach and suggesting a role for these proteins in the phloem during SAR. To identify novel components of SAR, transfer DNA mutants of differentially abundant phloem proteins were assayed for SAR competence. This analysis identified a number of new proteins (m-type thioredoxins, major latex protein-like protein, ULTRAVIOLET-B RESISTANCE8 photoreceptor) that contribute to the SAR response. The Arabidopsis SAR phloem proteome is a valuable resource for understanding SAR long-distance signaling and the dynamic nature of the phloem during plant-pathogen interactions.

The starch molecular structure and physicochemical properties of two medium-grain rice cultivars from Arkansas (Bengal, Medark) and from California (M202, M204) were determined and compared when they were grown in their respective locations and grown together in Arkansas to better understand the impacts of genetics and environment on starch characteristics. Both M202 and M204 contained significantly higher amylose contents (13.2-15.3%) compared with the Arkansas cultivars (11.6-12.4%). Starch from the Arkansas rice cultivars exhibited higher pasting and gelatinization temperatures and higher enthalpy values. Rice amylopectin from the California cultivars consisted of a smaller proportion of intermediate chains (DP 13-24), and had a lower molecular weight and a smaller radius of gyration. When the four cultivars were grown together in Arkansas, the ranges for amylose content narrowed (10.6-12.4%), their differences in thermal and pasting properties became smaller, and the molecular characteristics of amylose and amylopectin changed for all four cultivars. This study demonstrated that genetics, location, and crop year all contributed to variations in rice starch fine structure and physicochemical properties.

Recreational and industrial development is rapidly expanding in the boreal forest of western Canada. Concerns exist that such activity is facilitating the introduction and spread of non-native species such as exotic earthworms. The mechanisms by which earthworms are introduced and spread in forested systems are not well understood. Given the poor intrinsic dispersal abilities of earthworms, we propose 4 major introduction mechanisms: 1) abandonment of worms brought as fishing bait; 2) dispersal via vehicles; 3) dispersal via vertebrate predators; or 4) dispersal via waterways. To test these hypotheses, we sampled earthworms in forest stands near boat launches, roads, seismic lines, forest interiors, and remote shorelines of lakes in the boreal forest of northern Alberta, Canada. Boat launches and roads had a significantly higher probability of earthworm occurrence (54% of plots occupied) compared with the other locations (13% of plots occupied). Species commonly used as fishing bait occurred more...

In the life of the Anglican Communion today, an approach which expresses ‘ardour’, a response to the Gospel which tends towards freedom from institutional restraint, is favoured over an approach of ‘order’, which sees the regulation of the life of the church as itself a witness to the ordered will of God. There is both an ‘ardour of the left’, which seeks to loosen the restrictions of canon law to allow a greater ‘inclusiveness’, and an ‘ardour of the right’, which is prepared to override traditional understandings of jurisdiction in the defence of ‘orthodoxy’. The First Epistle to Clement bears witness to an ancient tradition of respect for order in the life of the church. The ‘Windsor Lambeth Process’ in the Anglican Communion – as developed by the Primates' Meeting at Dromantine in 2006, and affirmed at their meeting in 2007 at Dar es Salaam – furthers just such an ordered approach to the life of the Communion, by its requests to the North American Churches through due process, by the development of mechanisms to address questions of alternative episcopal oversight, by the Listening Process to address the moral questions under debate, and by the process to draft and adopt an Anglican Covenant. These initiatives are all intended to strengthen ‘the bonds of affection’, and to secure the future of the Anglican Communion as an international family of Churches.

Regulation of the rat glutathione S-transferase A2 (GSTA2) gene by glucocorticoids is biphasic in its concentration dependence to glucocorticoids, with concentrations of 10-100 nM repressing gene activity (GR-dependent), and concentrations above 1 microM increasing transactivation (PXR-dependent) in adult rat hepatocytes or transient transfection assays. Over-expression of either C/EBP alpha or beta negatively regulates basal and inducible expression of a 1.65 Kb GSTA2 luciferase reporter, and synergizes the response to glucocorticoids (GC). C/EBP responsive elements have been identified in the GSTA2 5'-flanking sequence, associated with the palindrominic Glucocorticoid Responsive Element (GRE), the Ah receptor response elements, and the antioxidant response element. In reporters lacking the palindromic GRE, negative regulation by GC is observed only when C/EBP alpha is co-expressed. Co-transfection of C/EBP alpha/beta induced gene expression of the GSTA2 XRE reporter, but negatively regulated the GSTA2 ARE-reporter. In contrast, the ARE from the rat NAD(P)H quinone oxidoreductase gene was induced by co-transfection of C/EBPs, but was still negatively regulated by GC. PXR-induction of the GSTA2 reporter was partially ablated by co-transfection of C/EBP alpha and enhanced by co-transfection of C/EBPbeta. We conclude that C/EBP alpha and beta are involved in GC-dependent repression of GSTA2 gene expression and ARE sequences that bind C/EBPs appears to be critical for these responses.

Nuclear receptors are transcription factors which sense changing environmental or hormonal signals and effect transcriptional changes to regulate core life functions including growth, development, and reproduction. To support this function, following ligand-activation by xenobiotics, members of subfamily 1 nuclear receptors (NR1s) may heterodimerize with the retinoid X receptor (RXR) to regulate transcription of genes involved in energy and xenobiotic metabolism and inflammation. Several of these receptors including the peroxisome proliferator-activated receptors (PPARs), the pregnane and xenobiotic receptor (PXR), the constitutive androstane receptor (CAR), the liver X receptor (LXR) and the farnesoid X receptor (FXR) are key regulators of the gut:liver:adipose axis and serve to coordinate metabolic responses across organ systems between the fed and fasting states. Non-alcoholic fatty liver disease (NAFLD) is the most common liver disease and may progress to cirrhosis and even hepatocellular carcinoma. NAFLD is associated with inappropriate nuclear receptor function and perturbations along the gut:liver:adipose axis including obesity, increased intestinal permeability with systemic inflammation, abnormal hepatic lipid metabolism, and insulin resistance. Environmental chemicals may compound the problem by directly interacting with nuclear receptors leading to metabolic confusion and the inability to differentiate fed from fasting conditions. This review focuses on the impact of nuclear receptors in the pathogenesis and treatment of NAFLD. Clinical trials including PIVENS and FLINT demonstrate that nuclear receptor targeted therapies may lead to the paradoxical dissociation of steatosis, inflammation, fibrosis, insulin resistance, dyslipidemia and obesity. Novel strategies currently under development (including tissue-specific ligands and dual receptor agonists) may be required to separate the beneficial effects of nuclear receptor activation from unwanted metabolic side effects. The impact of nuclear receptor crosstalk in NAFLD is likely to be profound, but requires further elucidation. This article is part of a Special Issue entitled: Xenobiotic nuclear receptors: New Tricks for An Old Dog, edited by Dr. Wen Xie.

Polychlorinated biphenyls (PCBs) are environmental pollutants associated with non-alcoholic-steatohepatitis (NASH), diabetes, and obesity. We previously demonstrated that the PCB mixture, Aroclor 1260, induced steatohepatitis and activated nuclear receptors in a diet-induced obesity mouse model. This study aims to evaluate PCB interactions with the pregnane-xenobiotic receptor (Pxr: Nr1i2) and constitutive androstane receptor (Car: Nr1i3) in NASH. Wild type C57Bl/6 (WT), Pxr(-/-) and Car(-/-) mice were fed the high fat diet (42% milk fat) and exposed to a single dose of Aroclor 1260 (20 mg/kg) in this 12-week study. Metabolic phenotyping and analysis of serum, liver, and adipose was performed. Steatohepatitis was pathologically similar in all Aroclor-exposed groups, while Pxr(-/-) mice displayed higher basal pro-inflammatory cytokine levels. Pxr repressed Car expression as evident by increased basal Car/Cyp2b10 expression in Pxr(-/-) mice. Both Pxr(-/-) and Car(-/-) mice showed decreased basal respiratory exchange rate (RER) consistent with preferential lipid metabolism. Aroclor increased RER and carbohydrate metabolism, associated with increased light cycle activity in both knockouts, and decreased food consumption in the Car(-/-) mice. Aroclor exposure improved insulin sensitivity in WT mice but not glucose tolerance. The Aroclor-exposed, Pxr(-/-) mice displayed increased gluconeogenic gene expression. Lipid-oxidative gene expression was higher in WT and Pxr(-/-) mice although RER was not changed, suggesting PCB-mediated mitochondrial dysfunction. Therefore, Pxr and Car regulated inflammation, behavior, and energy metabolism in PCB-mediated NASH. Future studies should address the 'off-target' effects of PCBs in steatohepatitis.

Systemic acquired resistance (SAR) is a plant defense response in which an initial localized infection affords enhanced pathogen resistance to distant, uninfected leaves. SAR requires efficient long-distance signaling between the infected leaf, where SAR signals are generated, and the distant uninfected leaves that receive them. A growing body of evidence indicates that the lipid transfer protein DIR1 (Defective in Induced Resistance) is an important mediator of long-distance SAR signaling. In a recent publication, we investigated if cell-to-cell movement through plasmodesmata is required for long-distance movement of DIR1 during SAR. We determined that overexpression of Plasmodesmata-Located Proteins (PDLP1 and 5) negatively impacted long-distance DIR1 movement and SAR competence, suggesting that movement through plasmodesmata contributes to long-distance signal movement during SAR.

The purpose of this chapter is to provide insight into which human cytochromes P450 (CYPs) may be involved in metabolism of chemical carcinogens and anticancer drugs. A historical overview of this field and the development of literature using relevant animal models and expressed human CYPs have provided information about which specific CYPs may be involved in carcinogen metabolism. Definition of the biochemical properties of CYP activity came from several groups who studied the reaction stoichiometry of butter yellow and benzo[α]pyrene, including their role in induction of these enzyme systems. This chapter will list as much as is known about the human CYPs involved in carcinogen and anticancer drug metabolism, as well as summarize studies with rodent CYPs. A review of three major classes of anticancer drugs and their metabolism in humans is covered for cyclophosphamide, procarbazine, and anthracycline antibiotics, cancer chemotherapeutic compounds extensively metabolized by CYPs. The emerging information about human CYP gene polymorphisms as well as other enzymes involved in foreign compound metabolism provides considerable information about how these genetic variants affect carcinogen and anticancer drug metabolism. With information available from individual's genomic sequences, consideration of populations who may be at risk due to environmental exposure to carcinogens or how to optimize their cancer therapy regimens to enhance efficacy of the anticancer drugs appears to be an important field of study to benefit individuals in the future.

The phytohormone salicylic acid (SA) plays an important role in several disease resistance responses. During the Age-Related Resistance (ARR) response that occurs in mature Arabidopsis responding to Pseudomonas syringae pv tomato (Pst), SA accumulates in the intercellular space where it may act as an antimicrobial agent. Recently we measured intracellular and intercellular SA levels in young, ARR-incompetent plants responding to virulent and avirulent strains of Pst to determine if intercellular SA accumulation is a component of additional defense responses to Pst. In young plants virulent Pst suppressed both intra- and intercellular SA accumulation in a coronatine-dependent manner. In contrast, high levels of intra- and intercellular SA accumulated in response to avirulent Pst. Our results support the idea that SA accumulation in the intercellular space is an important component of multiple defense responses. Future research will include understanding how mature plants counteract the effects of coronatine during the ARR response.

The conventional corn wet-milling process requires a long steeping time and has environmental and health concerns from the use of SO2. A recently proposed two-stage enzymatic milling procedure with the first stage of water soaking and coarse grinding of corn and the second stage of incubating with enzymes has been shown to reduce the soaking time and possibly eliminate the need for SO2 addition. This current work explored the applications of protease and high-intensity ultrasound in the second stage of the two-stage enzymatic milling for corn starch isolation to further shorten the process time without use SO2. of The starch yield from sonication alone was 55.2–67.8% (starch db) as compared with 53.4% of the water-only control with stirring for 1 hr and 71.1% of the conventional control with SO2 and lactic acid steeping for 48 hr. Protease digestion alone for 2 hr was not effective (45.8–63.9% yield) in isolating corn starch, but the starch recovery was increased to 61.2–76.1% when protease was c...

The atomic processes underlying cyclic fatigue was investigated in a metallic glass using molecular-dynamics simulations. A simple four component Lennard–Jones model was used to characterize the behavior of the free volume during deformation. The deformation behavior observed was typical of that seen experimentally, involving both elastic and plastic strains, load history dependence and strain rate sensitivity. Changes in free volume and excess strain were monitored during deformation to demonstrate how the stress state affects the distribution of free volume and how regions with excess free volume preferentially deform. Simulation results indicated that free volume levels were increased and localized during deformation, a process that was greatly accelerated under cyclic loading conditions. The results are used to rationalize the poor fatigue properties commonly reported for metallic glasses.

Documentation is made of the discovery of the Poor Knights spleenwort, (Asplenium pauperequitum) in a sample of vascular plant specimens collected from The Forty Fours. These islands are the easternmost outlier of the Chatham Islands archipelago. Hitherto this fern had been believed endemic to the Poor Knights Islands and Mokohinau Islands of the Hauraki Gulf, off eastern Northland, North Island, New Zealand. Frond and spore morphology together with chloroplast DNA sequences were used to confirm its identity. Whether this fern disjunction of some 1245 km is the result of vicariance or longdistance dispersal is discussed and long‐distance dispersal of fern spores or whole sporangia is considered most likely.

As plants mature it has been observed that some become more resistant to normally virulent pathogens. The ability to manifest the Age-Related Resistance (ARR) response in Arabidopsis to Pseudomonas syringae pathovars tomato ( Pst) coincided with the transition to flowering in plants both delayed and accelerated in the transition to flowering. ARR was also associated with a change in PR-1 gene expression, such that young plants expressed PR-1 abundantly at 3 days post inoculation (dpi) while mature plants expressed much less. The Arabidopsis ARR response requires SA accumulation via isochorismate synthase ( ICS1 ) [24] . ICS1 was expressed one dpi with virulent and avirulent Pst in both young and mature plants. The ARR response was also effective versus avirulent Pst providing an additional 4-fold limitation in bacterial growth. Arabidopsis ARR was found to be ineffective against two necrotrophs, Erwinia carotovora subspecies carotovora (bacterium) and Botrytis cinerea (fungus) and one obligate biotroph, Erysiphe cichoracearum (fungus). However, mature wild type, SA-deficient sid2 and NahG plants supported little growth of the obligate biotrophic oomycete, Peronospora parasitica . Therefore ARR to P. parasitica appears to be SA-independent, however the level of ARR resistance was somewhat reduced in these mutants in some experiments. Thus, there may be numerous defence pathways that contribute to adult plant resistance in Arabidopsis.

Eight U.S. long-grain rice cultivars were studied for chemical compositions, physicochemical properties, and leaching characteristics in relation to hardness and stickiness of rice flour paste and cooked rice. There were differences in the chemical composition of rice kernels among the eight rice cultivars, including crude protein (6.6–9.3%), crude fat (0.18–0.51%), and apparent amylose content by iodine colorimetry (19.6–27.0%). Differences were also observed in gelatinization temperatures and enthalpies, pasting temperatures and viscosities, leached/insoluble amylose, soluble solids, and hardness and stickiness of rice flour pastes and cooked rice kernels. The quantity and molecular size distribution of the leached starch molecules varied greatly among the samples. Protein and crude lipid contents negatively correlated with hardness of rice flour paste and cooked rice, but positively correlated with stickiness. Apparent amylose content correlated with gel properties but not cooked rice texture,...

A total of 75 taxa (including 1 hybrid) are reported as new to the flora of the Norfolk Island group, in the south‐west Pacific Ocean. Of these 1 is endemic (Achyranthes margaretarum), and 10 (2 pteridophytes, 8 anthophytes) taxa are considered indigenous and appear to represent either new natural long‐distance colonisations of Norfolk Island group from Australia and New Zealand or are new identifications of indigenous taxa either treated under other indigenous names or as naturalised in the Norfolk Flora. The remaining 64 taxa are considered naturalisations from resident gardens, or recent arrivals via human traffic from Australia or New Zealand. Aside from these records we discuss and update information on a further 27 taxa either covered by the last Norfolk Island flora treatment, or noted in subsequent works. A new species, Geranium gardneri, is described and treated as indigenous to Australia and naturalised in Norfolk I. and New Zealand. Nephrolepis flexuosa is reinstated for the non‐tubero...

The Arabidopsis proline-rich extensin-like receptor kinase (PERK) family consists of 15 predicted receptor kinases. A comprehensive expression analysis was undertaken to identify overlapping and unique expression patterns within this family relative to their phylogeny. Three different approaches were used to study AtPERK gene family expression, and included analyses of the EST, MPSS and NASCArrays databases as well as experimental RNA blot analyses. Some of the AtPERK members were identified as tissue-specific genes while others were more broadly expressed. While in some cases there was a good association between these different expression patterns and the position of the AtPERK members in the kinase phylogeny, in other cases divergence of expression patterns was seen. The PERK expression data identified by the bioinformatics and experimental approaches were found generally to show similar trends and supported the use of data from large-scale expression studies for obtaining preliminary expression data. Thus, the bioinformatics survey for ESTs and microarrays is a powerful comprehensive approach for obtaining a genome-wide view of genes in a multigene family.

Evolution in the genus Pratia (Campanulaceae) has been studied using a variety of techniques. The distribution of chromosome races in P. angulata has been plotted and results suggest that although they generally occupy different geographic areas there are large areas of overlap. No consistent morphological differences were found between these chromosome races. The existence of hybrids between P. angulata and P. perpusilla with 1 1x and 13x chromosome numbers has been established using genomic in situ hybridization (GISH), and random amplified polymorphic DNA (RAPD) analysis suggests several independent origins for these hybrids. Artificial hybridization studies showed a high degree of compatibility in almost all the combinations that were attempted. DNA sequences derived from both the nuclear genome (internal transcribed spacer of the rDNA locus, ITS) and chloroplast genomes (trnL intron and trnL‐trnF spacer) were used to construct phylogenies. Colensoaphysaloides has been shown to be distinct fr...

New Zealand has as many naturalized plant species as natives, and the invasion has yet to slow. The current composition and distribution of the naturalized flora are dominated by the time since species introduction and by human factors such as population density, at spatial scales from region to neighborhood. Additional index words: Eradication, introduction effort, invasive plant, propagule pressure, weed. Abbreviations: NZ, New Zealand; SE, standard error of the mean.

As Arabidopsis plants mature, they develop age-related resistance (ARR) to virulent Pseudomonas syringae. As for other defense responses, salicylic acid (SA) accumulation is required for ARR [Kus JV, Zaton K, Sarkar R, Cameron RK. Age-related resistance in Arabidopsis is a developmentally regulated defense response to P. syringae. Plant Cell 2002;14:479–90]. SA levels in the intercellular space increased during ARR and correlated in some experiments with anti-bacterial activity detection in intercellular washing fluids. Growth of Pseudomonas in culture was inhibited by 1 mM SA, providing support for an anti-microbial role for SA during ARR. Application of SA to the intercellular space rescued the ARR-defective mutant sid2, but not the SA-hydrolyzing transgenic line, NahG. The protection afforded by SA application in sid2 was observed only while SA levels remained elevated in the intercellular space. Destruction of SA in the intercellular space, by salicylate hydroxylase application, reduced the ARR response in wild type plants. These results strongly suggest that SA accumulation in the intercellular space is critical for manifestation of ARR.

The results of over thirty separate excavations and watching briefs along the line of the Antonine Wall are presented. The alignment and character of the frontier works and fort defences were clarified in several places. New information was obtained regarding a possible enclosure on the north side of the Wall near Auchendavy. Material includes

Activation of plant defences following recognition of pathogen attack involves complex reiterative signal networks with extensive signal amplification and cross-talk. The results of two approaches that have been taken to analyse signalling in plant-microbe interactions are discussed here. Activation tagging with T-DNA harbouring multiple 35S enhancer elements was employed as a gain-of-function approach to dissect signalling related to bacterial pathogen resistance in Arabidopsis thaliana. From a screen of approximately 5000 activation tagged lines, one line was identified as harbouring a T-DNA leading to over-expression of an apoplastic aspartic protease (CDR-1), that resulted in resistance to normally virulent Pseudomonas syringae. The second approach was to screen for loss-of-function mutants in T-DNA tagged populations. From a screen of 11 000 lines, one line, defective in induced resistance-1 (dir-1) lost resistance to normally avirulent P. syringae. Models for action of the products of the CDR-1 and DIR-1 genes suggest involvement of peptide and lipid signals in systemic disease resistance responses in A. thaliana.

Treatment of rats with peroxisome proliferators is known to affect gene expression, including suppression of CYP2C11. The current study examined the mechanism of negative regulation of CYP2C11, comparing the effects of a classic peroxisome proliferator, nafenopin, with those of the steroid dehydroepiandrosterone (DHEA). In vivo dose-response experiments for DHEA were carried out with rats. Only the highest dose of DHEA in the diet (0.45%), a dose previously shown to produce peroxisome proliferation, caused suppression of CYP2C11 expression. Lower doses of DHEA (0.012 to 0.20% in diet) had little effect on CYP2C11 expression. In HepG2 cells, negative regulation of a CYP2C11 reporter gene by nafenopin required coexpression of PPARalpha, whereas negative regulation by DHEA did not. Deletion analysis revealed that the responsive region for both DHEA and nafenopin was between -108 and -60 relative to the transcription start site. Mutations in several putative transcription factor binding sites in the 5'-flanking region of CYP2C11 were produced. A mutation at -121 bp significantly diminished basal expression of CYP2C11 but did not affect negative regulation by DHEA or nafenopin. A mutation at -75 bp had only a small effect on basal expression but completely abolished negative regulation by DHEA and nafenopin. Gel shift experiments indicated that PPARalpha/RXRalpha heterodimers do not bind DNA in this region. Therefore, the sequence at -75 bp of CYP2C11 is necessary for negative regulation by both DHEA and nafenopin. However, the upstream events leading to suppression at this site must differ for DHEA and nafenopin.

In Arabidopsis, much of what we know about the phytohormone salicylic acid (SA) and its role in plant defense comes from experiments using young plants. We are interested in understanding why young plants are susceptible to virulent strains of Pseudomonas syringae, while mature plants exhibit a robust defense response known as Age-Related Resistance (ARR). SA-mediated signaling is important for defense in young plants, however, ARR occurs independently of the defense regulators NPR1 and WHY1. Furthermore, intercellular SA accumulation is an important component of ARR, and intercellular washing fluids from ARR-competent plants exhibit antibacterial activity, suggesting that SA acts as an antimicrobial agent in the intercellular space. Young plants accumulate both intracellular and intercellular SA during PAMP- and Effector-Triggered Immunity, however, virulent P. syringae promotes susceptibility by suppressing SA accumulation using the phytotoxin coronatine. Here we outline the hypothesis that mature, ARR-competent Arabidopsis alleviates coronatine-mediated suppression of SA accumulation. We also explore the role of SA in other mature-plant processes such as flowering and senescence, and discuss their potential impact on ARR.

Olearia crebra is described as a new species. It is distinguished from other New Zealand species of Olearia by a set of characters including large leaves and the capitula having numerous involucral bracts, florets, and ray florets. O. crebra is restricted to montane parts of Waima Forest, western Northland, where it occurs on Hauturu, Te Raupua, Mt Misery, and upper Whirinaki Valley. As the populations of O. crebra are small and localised, and because there is a continuing need to manage browsing mammals in Waima Forest, it is listed as a Nationally Endangered species.

Aim To examine patterns of hybridization and genotype mixing within the genus Coprosma J.R.Forst. & G.Forst. (Rubiaceae). Location New Zealand Methods Nucleotide sequence was determined for the internal transcribed spacer (ITS) and external transcribed spacer (ETS) regions of nuclear ribosomal DNA for fifty individuals from thirty-six taxa within the New Zealand component of the genus Coprosma. Results Mixed sequences were found to be widespread in Coprosma. Direct sequencing of ITS polymerase chain reaction (PCR) products from seven polyploid taxa showed evidence of sequence mixtures. Cloning and sequencing of individual PCR products from two polyploids confirmed the presence of multiple templates, one of which corresponded to that of a diploid. Intra-individual heterogeneity was also seen in a hybrid diploid taxon, with the mixed nucleotides corresponding to those of the parental lineages. Finally the ITS sequences of twenty-two diploid taxa showed that eleven contained intra-individual heterogeneity. Conclusions We conclude that the widespread occurrence of sequence mixtures in Coprosma results from of frequent hybridization. We also conclude that concerted evolution of the ITS and ETS regions is depressed. We propose that these characteristics evolved as a mechanism to maintain high levels of heterogeneity and suggest that this is adaptive for Coprosma in climatically unstable and physically complex New Zealand landscapes. These landscapes have been subjected to repeated oscillations between stadial and interstadial environments during the Pleistocene.