bluuebunny/crossref_metadata_2025 huggingface dataset:
ANTI‐APOPTOTIC EFFECT OF HEAT SHOCK PROTEIN 90 ON HYPOXIA‐MEDIATED CARDIOMYOCYTE DAMAGE IS MEDIATED VIA THE PHOSPHATIDYLINOSITOL 3‐KINASE/AKT PATHWAY
Authors: Wang Wei , Peng Yizhi , Wang Yuanyuan , Zhao Xiaohui , Yuan Zhiqiang
Published: March 2009

Hypoxia‐induced cardiomyocyte apoptosis contributes significantly to cardiac dysfunction following trauma, shock and burn injury. There is evidence that heat shock protein (HSP) 90 is anti‐apoptotic in cardiomyocytes subjected to a variety of apoptotic stimuli. Because HSP90 acts as an upstream regulator of the serine/threonine protein kinase Akt survival pathway during cellular stress, we hypothesized that HSP90 exerts a cardioprotetive effect via the phosphatidylinositol 3‐kinase (PI3‐K)/Akt pathway.

Neonatal rat cardiomyocytes were subjected to normoxia or hypoxia in the absence or presence of the HSP90 inhibitor geldanamycin (1 µg/mL). Cardiomyocyte apoptosis was assessed by release of lactate dehydrogenase (LDH), terminal deoxyribonucleotidyl transferase‐mediated dUTP–digoxigenin nick end‐labelling (TUNEL) staining and caspase 3 activity. Expression of HSP90, Akt, Bad and cytochrome c release was determined by western blot analysis.

Following exposure of cells to hypoxia, HSP90 was markedly elevated in a time‐dependent manner, reaching a peak at 6 h (eightfold increase). Geldanamycin significantly increased hypoxia‐induced release of LDH by 114%, the percentage of apoptotic cardiomyocytes by 102% and caspase 3 activity by 78%. Pretreatment of cells with geldanamycin also suppressed phosphorylation of both Akt and its downstream target Bad, but promoted the mitochondrial release of cytochrome c.

In conclusion, HSP90 activity is enhanced in cardiomyocytes following hypoxic insult. The anti‐apoptotic effect of HSP90 on cardiomyocytes subjected to hypoxia is mediated, at least in part, by the PI3‐K/Akt pathway.
EFFECTS OF SODIUM FERULATE ON HUMAN OSTEOARTHRITIC CHONDROCYTES AND OSTEOARTHRITIS IN RATS
Authors: Shang Liang , Qin Jun , Chen Liao‐Bin , Liu Bao‐Xin , Jacques Magdalou , Wang Hui
Published: March 2009

Oxidation, inflammation and apoptosis are involved in the aetiology and pathology of osteoarthritis (OA). Sodium ferulate (SF) has been demonstrated to have anti‐oxidant, anti‐inflammatory and anti‐apoptotic actions in cardiovascular, hepatic and diabetic disorders. These findings suggest that SF may have beneficial effects on OA. Therefore, present study investigated the effects of SF in an in vivo rat OA model, as well as in vitro in human OA chondrocytes.

Rats were divided into the following groups: (i) an untreated control group; (ii) papain‐induced OA; (iii) OA rats treated with 0.1 or 0.5% SF; and (iv) normal rats injected with 0.5% SF intra‐articularly. Human chondrocytes from OA patients were cultured before being stimulated with 2 ng/mL interleukin‐1β and subsequently treated with SF (125, 250 and 500 µmol/L). The effects of SF were evaluated both in vivo and in vitro.

In OA rats, SF treatment dose‐dependently reversed pathological changes in OA cartilage, decreased BAX‐immunopositive chondrocytes and increased Bcl‐2‐immunopositive chondrocytes. Both in vivo and in vitro analyses demonstrated a significant decrease in matrix metalloproteinase‐1 and an increase in tissue‐specific inhibitor of metalloproteinase‐1. In vitro, SF enhanced chondrocyte proliferation and decreased nitric oxide production and apoptosis.

The results demonstrate that SF dose‐dependently suppresses pathological processes in both in vitro and in vivo OA models. Thus, SF could be a therapeutic strategy for the treatment of OA.
EPIGALLOCATECHIN‐3‐GALLATE ATTENUATES CARDIAC HYPERTROPHY IN HYPERTENSIVE RATS IN PART BY MODULATION OF MITOGEN‐ACTIVATED PROTEIN KINASE SIGNALS
Authors: Chen Dan‐Dan , Dong Yu‐Gang , Liu Dan , He Jian‐Gui
Published: March 2009

It has been demonstrated that epigallocatechin‐3‐gallate (EGCG) inhibits cardiac hypertrophy through its antihypertensive and anti‐oxidant effects. However, the underlying molecular mechanism is not clear.

In the present study, we tested the hypothesis that EGCG attenuates transaortic abdominal aortic constriction (TAC)‐induced ventricular hypertrophy by regulating mitogen‐activated protein kinase (MAPK) signal pathways in hypertensive rats. Four groups of rats were used: (i) a sham‐operated control group; (ii) an EGCG‐treated (50 mg/kg per day, i.p., for 21 days) sham‐operated group; (iii) a TAC group; and (iv) an EGCG‐treated TAC group. Histological analysis of whole hearts and biochemical analyses of left ventricular (LV) tissue were used to investigate the effects of EGCG.

The results showed that the LV myocyte diameter and the expression of atrial natriuretic peptide, brain natriuretic peptide and β‐myocardial heavy chain were significantly decreased in the EGCG‐treated (50 mg/kg per day, i.p.) TAC group. Levels of reactive oxygen species and malondialdehyde in the lV were significantly reduced by EGCG in the TAC group. Total superoxide dismutase, catalase and glutathione peroxidase activities were decreased in the TAC group, and this decrease was significantly restored by EGCG treatment. Phosphorylation of extracellular signal‐regulated kinase 2, p38 and c‐Jun N‐terminal kinase 1 was significantly reversed in the LV of EGCG‐treated TAC rats (40%, 53% and 52%vs TAC, respectively), accompanied by significant inhibition of nuclear factor‐κB and activator protein‐1. Transaortic abdominal aortic constriction significantly upregulated LV expression of matrix metalloproteinase‐9 from 32 ± 6 to 100 ± 12% and this increase was inhibited by EGCG treatment (from 100 ± 12 to 50 ± 15%). In addition, TAC decreased mitochondrial DNA copy number and the activity of respiratory chain complexes I (from 100 ± 7 to 68 ± 5%), III (from 100 ± 4 to 2 ± 5%) and IV (from 766 ± 2 to 100 ± 5%); this decrease was reversed by EGCG treatment to levels seen in sham‐operated rats.

In conclusion, EGCG attenuates TAC‐induced ventricular hypertrophy in hypertensive rats in part by suppression of anti‐oxidant enzymes and regulation of MAPK signals.
Contrasting demographics of tropical savanna and temperate forest eucalypts provide insight into how savannas and forests function. A case study using Corymbia clarksoniana from north‐eastern Australia
Authors: WILLIAMS PAUL R.
Published: March 2009

Eucalypts (Eucalyptus spp. and Corymbia spp.) dominate many communities across Australia, including frequently burnt tropical savannas and temperate forests, which receive less frequent but more intense fires. Understanding the demographic characteristics that allow related trees to persist in tropical savannas and temperate forest ecosystems can provide insight into how savannas and forests function, including grass–tree coexistence. This study reviews differences in critical stages in the life cycle of savanna and temperate forest eucalypts, especially in relation to fire. It adds to the limited data on tropical eucalypts, by evaluating the effect of fire regimes on the population biology of Corymbia clarksoniana, a tree that dominates some tropical savannas of north‐eastern Australia. Corymbia clarksoniana displays similar demographic characteristics to other tropical savanna species, except that seedling emergence is enhanced when seed falls onto recently burnt ground during a high rainfall period. In contrast to many temperate forest eucalypts, tropical savanna eucalypts lack canopy‐stored seed banks; time annual seed fall to coincide with the onset of predictable wet season rain; have very rare seedling emergence events, including a lack of mass germination after each fire; possess an abundant sapling bank; and every tropical eucalypt species has the ability to maintain canopy structure by epicormically resprouting after all but the most intense fires. The combination of poor seedling recruitment strategies, coupled with characteristics allowing long‐term persistence of established plants, indicate tropical savanna eucalypts function through the persistence niche rather than the regeneration niche. The high rainfall‐promoted seedling emergence of C. clarksoniana and the reduction of seedling survival and sapling growth by fire, support the predictions that grass–tree coexistence in savannas is governed by rainfall limiting tree seedling recruitment and regular fires limiting the growth of juvenile trees to the canopy.
Habitat selection by the swamp wallaby (Wallabia bicolor) in relation to diel period, food and shelter
Authors: DI STEFANO JULIAN , YORK ALAN , SWAN MATTHEW , GREENFIELD ANDREW , COULSON GRAEME
Published: March 2009

Patterns of resource selection by animals may be influenced by sex, and often change over a 24‐h period. We used a dry sclerophyll landscape managed for commercial timber production to investigate the effects of sex and diel period on habitat selection by the swamp wallaby (Wallabia bicolor). We predicted that selection would be (i) affected by both sex and diel period; and (ii) positively related to lateral cover during the day, but to food resources at night. Non‐metric multidimentional scaling indicated that some of the available habitats differed markedly with respect to visibility (an indicator of lateral cover), fern cover, forb cover, wallaby density and a forage quality index, providing the basis for non‐random habitat selection. At the landscape scale, wallabies showed strong selection for 5‐year‐old regenerating sites, selected against 10‐year‐old regenerating sites and unharvested forest, and avoided recently harvested (3–10 months post‐harvest) sites completely. At the scale of individual home ranges, a pooled male and female sample demonstrated selection for unharvested forest over recently harvested sites during both diurnal and nocturnal periods. A separate analysis showed that both sex and diel period influenced the selection of 5‐ and 10‐year‐old sites and the surrounding unharvested forest. Using a novel approach, we demonstrated that diurnal habitat selection by both sexes was negatively correlated with visibility, representing stronger selection for areas with more lateral cover. Nocturnal selection by females was positively correlated with values of a forage quality index, but this was not the case for males. We hypothesise that the observed patterns of selection were driven by the need to find food and avoid predators, but were also affected by the different reproductive strategies of males and females. Our results demonstrate the importance of incorporating factors such as sex and diel period into analyses of habitat selection.
Impacts of hive honeybees on Tasmanian leatherwood Eucryphia lucida Labill. (Eucryphiaceae)
Authors: MALLICK STEPHEN A. , DRIESSEN MICHAEL M.
Published: March 2009

Despite honeybees (Apis mellifera L.) occurring as a feral and commercially managed species in many parts of Australia, the effects of honeybees on native Australian ecosystems are poorly understood. We examined the impacts of honeybee apiaries on Tasmanian Leatherwood Eucryphia lucida Labill. (Eucryphiaceae) by comparing commercial apiary sites with control sites >2 km from the nearest apiary. Feral honeybees were common at control sites (73% of honeybees feral) but were scarce at apiary sites (2%), and hive honeybees appeared to be competitively displacing feral honeybees near apiaries. Visit rates by native insects appeared to be un‐affected by the increased numbers of hive honeybees near apiaries. Standing crops of nectar sugar were significantly depressed at apiary sites. Pollen was rapidly removed from flowers at apiary sites resulting in full separation of the male and female flower‐phases (flowers completely dichogamous). In contrast, at control sites, pollen tended to remain in flowers into the female phase (flowers partially dichogamous). There was no difference in the total number of pollen grains deposited on stigmas or in percentage seed set among apiary and control sites. However, fruit set was elevated at apiary sites, possibly owing to reduced autonomous (within‐flower) selfing. Our study indicated that honeybees significantly reduce floral resources (nectar and pollen) around apiaries, although any competitive effects on native insects may have been obscured by large variation in the abundance of native insects among experimental sites.
Impact of storm‐burning on Melaleuca viridiflora invasion of grasslands and grassy woodlands on Cape York Peninsula, Australia
Authors: CROWLEY GABRIEL , GARNETT STEPHEN , SHEPHARD SUSAN
Published: March 2009

This paper examines invasion of grasslands on Cape York Peninsula, Australia, by Melaleuca viridiflora and other woody species, and the role of storm‐burning (lighting fires after the first wet season rains) in their maintenance. Trends in disturbance features, fuel characteristics, ground layer composition, and woody plants dynamics under combinations of withholding fire and storm‐burning over a 3‐year period were measured on 19 plots in three landscape settings. Population dynamics of M. viridiflora are described in detail and 20‐year population projections based on transition matrices under different fire regimes generated. Numerous M. viridiflora suckers occurred within the grass layer, increasing each year regardless of fire regime, and were rapidly recruited to the canopy in the absence of fire. Storm‐burning had little impact on fuel, ground layer or woody plant composition, but maintained open vegetation structure by substantially reducing recruitment of M. viridiflora suckers to the sapling layer, and by reducing the above‐grass‐layer abundance of several other invasive woody species. Population projections indicated that withholding fire for 20 years could cause a sevenfold increase of M. viridiflora density on Ti‐tree flats, and that annual to triennial storm‐burning should be effective at maintaining a stable open vegetation structure. These findings argue against vegetation thickening being an inevitable consequence of climate change. We conclude that a fire regime that includes regular storm‐burning can be effective for maintaining grasslands and grassy woodlands being invaded by M. viridiflora.
Impacts of the invasive Argentine ant on native ants and other invertebrates in coastal scrub in south‐eastern Australia
Authors: ROWLES ALEXEI D. , O'DOWD DENNIS J.
Published: March 2009

Invasive ants threaten native biodiversity and ecosystem function worldwide. Although their principal direct impact is usually the displacement of native ants, they may also affect other invertebrates. The Argentine ant, Linepithema humile (Dolichoderinae), one of the most widespread invasive ant species, has invaded native habitat where it abuts peri‐urban development in coastal Victoria in south‐eastern Australia. Here we infer impacts of the Argentine ant on native ants and other litter and ground‐dwelling invertebrates by comparing their abundance and taxonomic composition in coastal scrub forest either invaded or uninvaded by the Argentine ant. Species composition of native ants at bait stations and extracted from litter differed significantly between Argentine ant‐invaded and uninvaded sites and this was consistent across years. Argentine ants had a strong effect on epigeic ants, which were either displaced or reduced in abundance. The native ant Rhytidoponera victoriae (Ponerinae), numerically dominant at uninvaded sites, was completely absent from sites invaded by the Argentine ant. However, small hypogeic ants, including Solenopsis sp. (Myrmicinae) and Heteroponera imbellis (Heteroponerinae), were little affected. Linepithema humile had no detectable effect upon the abundance and richness of other litter invertebrates. However, invertebrate group composition differed significantly between invaded and uninvaded sites, owing to the varied response of several influential groups (e.g. Collembola and Acarina). Floristics, habitat structure and measured environmental factors did not differ significantly between sites either invaded or uninvaded by Argentine ants, supporting the contention that differences in native ant abundance and species composition are related to invasion. Changes in the native ant community wrought by Argentine ant invasion have important implications for invertebrate communities in southern Australia and may affect key processes, including seed dispersal.
Gut passage effect of the introduced red‐whiskered bulbul (Pycnonotus jocosus) on germination of invasive plant species in Mauritius
Authors: LINNEBJERG JANNIE F. , HANSEN DENNIS M. , OLESEN JENS M.
Published: March 2009

In Mauritius, many of the worst invasive plant species have fleshy fruits and rely on animals for dispersal. The introduced red‐whiskered bulbul (Pycnonotus jocosus) feeds on many fleshy‐fruited species, and often moves from invaded and degraded habitats into higher quality native forests, thus potentially acting as a mediator of continued plant invasion into these areas. Furthermore, gut passage may influence seed germination. To investigate this, we fed fleshy fruits of two invasive plant species, Ligustrum robustum and Clidemia hirta, to red‐whiskered bulbuls. Gut passage times of seeds were recorded. Gut‐passed seeds were sown and their germination rate and germination success compared with that of hand‐cleaned seeds, as well as that of seeds in whole fruits. Gut passage and hand‐cleaning had significant positive effects on germination of both species. Gut‐passed seeds of both C. hirta and L. robustum germinated faster than hand‐cleaned seeds. However, for L. robustum, this was only true when compared with hand‐cleaned seeds with intact endocarp; when compared with hand‐cleaned seeds without endocarp, there was no difference. For overall germination success, there was a positive effect of gut passage for C. hirta, but not for L. robustum. For both C. hirta and L. robustum, no seeds in intact fruits geminated, suggesting that removal of pulp is essential for germination. Our results suggest that, first, the initial invasion of native forests in Mauritius may not have happened so rapidly without efficient avian seed dispersers like the red‐whiskered bulbul. Second, the bulbul is likely to be a major factor in the continued re‐invasion of C. hirta and L. robustum into weeded and restored conservation management areas.
Changes in body condition and body size affect breeding and recruitment in fluctuating house mouse populations in south‐eastern Australia
Authors: MUTZE GREGORY J.
Published: March 2009

Changes in body condition and body size in field populations of house mice, Mus domesticus, were examined to investigate why mouse populations do not increase rapidly in some years when favourable environmental and demographic conditions indicate they might. Mice had repeated seasonal patterns each year in breeding, growth rates and body condition that reflected the seasonal availability of food, but mean levels for each parameter varied among years. In most years mice lost body condition during summer, breeding declined and population growth slowed. Rapid population growth occurred when body condition was generally high and was maintained throughout summer. Female mice with large body length were more likely to breed than smaller mice, at all times, but changes in body condition accounted for most of the variability in female breeding activity between years and between habitats, and for the seasonal changes in the importance of body length. During rapid population growth, the recruitment rate of juveniles relative to the number of breeding females was 150–300% higher than in other years but adult survival rates were not higher. The data indicate that the ability of mice to maintain body condition, particularly when subject to moisture stress in summer, affects the proportion of females breeding, the number of juveniles weaned and their body condition at weaning, and is promoted by foraging conditions that favour maintenance of juvenile body condition after weaning. These factors, in turn, greatly affect juvenile recruitment rates and eventual population density of mice. Low juvenile survival is suggested as a reason that numbers of house mice in southern Australian cereal‐growing areas do not increase rapidly in some years when other parameters are favourable. Similar processes are likely to play a role in regulating other rodent populations.
Seed morphological traits and genotypic diversity of weedy rice (Oryza sativa f. spontanea) populations found in the Thai Hom Mali rice fields of north‐eastern Thailand
Authors: PRATHEPHA PREECHA
Published: March 2009

Weedy rice (Oryza sativa f. spontanea) is a problematic weed in the Thai Hom Mali rice production areas of Thung Kula Ronghai in north‐eastern Thailand. There is a great need to initiate studies of weedy rice populations in order to perform basic studies to learn about the seed morphology and genetic diversity. The aims of this study were to determine the seed morphological traits and amylose content and to evaluate the genetic variation, based on the polymorphisms of nuclear and chloroplast DNA, of weedy rice. The seeds and flag leaves were collected from a total of 125 weedy rice plants at six rice fields in the region. For the samples, four morphological traits, the amylose content, and the chloroplast identity (ID) sequence and microsatellite genotypes at the waxy locus were determined. The weedy rice that was collected from the Thung Kula Ronghai region varied considerably in its amylose content and both the seed morphology and genotypes. Some of the weedy rice shared the common microsatellite alleles and chloroplast ID sequence with Thai Hom Mali and wild rice, Oryza rufipogon, indicating that the weedy rice in this region might originate from the introgression between cultivated rice and O. rufipogon, which often takes place in nature, mostly in a one‐way process from cultivated rice to O. rufipogon.
Effects of ferrous iron (Fe) on the germination and root elongation of paddy rice and weeds
Authors: NOZOE TAKUHITO , TACHIBANA MASAAKI , UCHINO AKIRA , YOKOGAMI NARIFUMI
Published: March 2009

Laboratory experiments were conducted to analyze the iron (Fe) tolerance of paddy weeds and rice varieties (Oryza sativa) for germination and root elongation. Under a waterlogged soil condition, the Fe(II) content in a soil solution increased with an increase in the ratio of rice straw to the soil. In the presence of 0.9% (w/w) straw to soil, which corresponds approximately to 8 t of straw applied to an area of 1 ha × 10 cm depth in the field, ∼80 mg L−1 of Fe(II) was produced in the soil solution. Based on this result, the seeds of rice and the weeds were incubated in a solution with <100 mg L−1 of Fe(II). The presence of 100 mg L−1 of Fe(II) suppressed the germination of Echinochloa crus‐galli var. crus‐galli, Cyperus serotinus, Cyperus difformis, and Monochoria korsakowii. However, it had no effect on the germination of Echinochloa oryzicola, Schoenoplectus juncoides (= Scirpus juncoides var. ohwianus), and Monochoria vaginalis. This level of Fe tolerance was the same as that of rice. These findings suggest that E. oryzicola, S. juncoides, and M. vaginalis can grow under more severe conditions than E. crus‐galli, C. serotinus, C. difformis, and M. korsakowii. In relation to seminal root elongation, the order of tolerance of Fe toxicity was O. sativa cv. Dunghan Shali > O. sativa cv. Hoshinoyume > E. oryzicola > M. vaginalis > S. juncoides. Thus, the results show that the tolerance of rice is greater than that of E. oryzicola, which had a comparatively strong tolerance among the weeds examined, and also that there are differences in tolerance among the rice varieties. These findings suggest that the difference in Fe tolerance is involved in weed control systems when organic materials are applied. If this difference is an important factor in the weed control system, Fe‐tolerant rice varieties, like cv. D. Shali, could facilitate weed control systems due to their higher Fe tolerance ability.
Selective growth suppression of five annual plant species by chalcone and naringenin correlates with the total amount of 4‐coumarate: coenzyme A ligase
Authors: YUN MIN‐SOO , CHEN WEIJUN , DENG FAN , YOGO YASUHIRO
Published: March 2009

The 4‐coumarate: coenzyme A ligase (4CL) is one of the key enzymes in the biosynthesis of lignin monomers. It has been demonstrated that the 4CL is a new potential target site for developing effective plant growth inhibitors. Although previous studies demonstrate that chalcone and naringenin differentially suppress the growth of several annual plant species, we show here that the compounds can inhibit the 4CL enzyme activity in the plants. The enzyme was extracted and partially purified from the leaf tissues of two tolerant plants (wheat and soybean) and three susceptible plants (tomato, barnyard grass, and common chickweed). A maximal 29‐fold purification of the enzyme, with a yield of 32% (tomato), was achieved by a six‐step procedure, including anion‐exchange column chromatography. Naringenin strongly inhibited the 4CL specific activity in wheat, soybean and barnyard grass, whereas chalcone showed the highest inhibitory effect in common chickweed. A good correlation was observed between the level of growth suppression by the compounds and the total 4CL amount in the plants. These results suggest that the inhibitor treatment at the same concentration could not inactivate the entire 4CL enzyme produced in the tolerant plants. Taken together, these results highlight the possibility of the 4CL as a new action site of growth suppression.
Germination, emergence, and dormancy of Mimosa pudica
Authors: CHAUHAN BHAGIRATH S. , JOHNSON DAVID E.
Published: March 2009

Mimosa pudica (common sensitive plant) is a problematic weed in many crops in tropical countries. Eight experiments were conducted to determine the effects of light, seed scarification, temperature, salt and osmotic stress, pH, burial depth, and rice residue on the germination, seedling emergence, and dormancy of M. pudica seeds. Scarification released the seeds from dormancy and stimulated germination, though the germination of the scarified seeds was not influenced by light. The scarification results indicate that a hard seed coat is the primary mechanism that restricts germination. The germination increased markedly with the exposure to high temperature “pretreatment” (e.g. 150°C), which was achieved by placing non‐scarified seeds in an oven for 5 min followed by incubation at 35/25°C day/night temperatures for 14 days. The germination of the scarified seeds was tolerant of salt and osmotic stress, as some seeds germinated even at 250 mmol L−1 NaCl (23%) and at an osmotic potential of −0.8 MPa (5%). The germination of the scarified seeds was >74% over a pH range of 5–10. The seedling emergence of the scarified seeds was 73–88% at depths of 0–2 cm and it gradually decreased with an increasing depth, with no seedling emergence at the 8 cm depth. The rice residue applied to the soil surface at rates of ≤6 t ha−1 did not influence the seedling emergence and dry weight. The information gained from this study identifies some of the factors that facilitate M. pudica becoming a widespread weed in the humid tropics and might help in developing components of integrated weed management practises to control this weed.
Control of the invasive liana, Hiptage benghalensis
Authors: VITELLI JOSEPH S. , MADIGAN BARBARA A. , VAN HAAREN PETER E. , SETTER STEPHEN , LOGAN PETER
Published: March 2009

The liana, hiptage (Hiptage benghalensis), is currently invading the wet tropics of northern Queensland and remnant bushland in south‐eastern Queensland, Australia. Trials using seven herbicides and three application methods (foliar, basal bark, and cut stump) were undertaken at a site in north Queensland (158 700 hiptage plants ha−1). The foliar‐applied herbicides were only effective in controlling the hiptage seedlings. Of the foliar herbicides trialed, dicamba, fluroxypyr, and triclopyr/picloram controlled >75% of the treated seedlings. On the larger plants, the cut stump applications were more effective than the basal bark treatments. Kills of >95% were obtained when the plants were cut close to ground level (5 cm) and treated with herbicides that were mixed with diesel (fluroxypyr and triclopyr/picloram), with water (glyphosate), or were applied neat (picloram). The costings for the cut stump treatment of a hiptage infestation (85 000 plants ha−1), excluding labor, would be $A14 324 ha−1 using picloram and $A5294 ha−1 and $A2676 ha−1, respectively, using glyphosate and fluroxypyr. Foliar application using dicamba for seedling control would cost $A1830 ha−1. The costs range from 2–17 cents per plant depending on the treatment. A lack of hiptage seeds below the soil surface, a high germinability (>98%) of the viable seeds, a low viability (0%) of 2 year old, laboratory‐stored fruit, and a seedling density of 0.1 seedlings m−2 12 months after a control program indicate that hiptage might have a short‐term seed bank. Protracted recolonization from the seed bank would therefore be unlikely after established seed‐producing plants have been controlled.
Growth, nitrogen fixation, and nutrient uptake of hairy vetch as a cover crop in a subtropical region
Authors: ANUGROHO FAJRI , KITOU MAKOTO , NAGUMO FUJIO , KINJO KAZUTOSHI , TOKASHIKI YOSHIHIRO
Published: March 2009

Hairy vetch (Vicia villosa), as a winter cover crop, can be used to suppress weeds in subtropical regions, as well as temperate regions. Information on the potential biomass growth of hairy vetch for weed control and nutrient accumulation is not available in subtropical regions. Hairy vetch was sown in November 2004, and October, November, and December 2005. The wide‐ranging cultivation period of hairy vetch indicated that it could be used in various cropping systems. It showed a higher biomass and nutrient accumulation when grown in subtropical Okinawa, Japan. Moreover, the biomass, and fixed carbon and magnesium (Mg) uptake in the above‐ground parts of hairy vetch were found to be the highest in late May, with the highest nitrogen (N), potassium, and calcium uptake in mid‐April and phosphorus (P) uptake in late March. Meanwhile, in the underground parts of the plant, they were highest in early May, except for the P and Mg uptake, which were highest in mid‐April. According to the sowing date, the biomass and nutrient uptake of hairy vetch that was harvested in February were higher when sown in October. Similarly, when harvested in March, the biomass and nutrient uptake were higher when sown in October or November. In April, they were higher when sown in November or December. Hairy vetch has the potential to effectively suppress weeds in the winter and the spring seasons related to its sufficient biomass during the growing seasons. However, both the sowing and harvesting times of hairy vetch should be considered with reference to the cropping system; the subsequent crop will be sown to meet the N requirement.
Assessment of the differential response of weeds to soil solarization by two methods
Authors: EL‐KEBLAWY ALI , AL‐HAMADI FATIMA
Published: March 2009

The efficacy of solarization in weed control under field conditions of the United Arab Emirates was evaluated by two methods: on‐farm weed assessment and a seed germination test. In the on‐farm weed assessment method, the weed frequency, density, and dry weight were compared in the solarized and non‐solarized plots that were cultivated with cabbage. Prior to solarization, the soil was artificially infested with the seeds of 10 weeds. Generally, the densities of seven species and dry weights of five species were significantly lower in the solarized plots as compared to the control. Launea mucronata, Capsella bursa‐pastoris, and Echinochloa colona were very sensitive to solarization, as they did not appear in the solarized plots. However, Portulaca oleracea and Melilotus indica were not significantly affected by soil solarization. In the second method, the germination was assessed for the seeds of four weedy species buried at three depths for different durations of solarization. The results confirmed the great sensitivity of L. mucronata and C. bursa‐pastoris seeds to solarization, as all had not germinated after 15 days of solarization, even at the 15 cm depth. The seeds of E. colona, however, were less sensitive after 15 days of solarization, especially at 7.5 cm and 15 cm, respectively. The seed germination method confirmed the resistance of the P. oleracea seeds to solarization. The results emphasized the importance of the germination test to provide accurate predictions about the spatial and temporal changes of the soil seed bank in solarized farms. This would help to determine the optimal duration of solarization in each farm, depending on the kind of weeds infesting the farm.
Surround suppression sharpens orientation tuning in the cat primary visual cortex
Authors: Okamoto Masahiro , Naito Tomoyuki , Sadakane Osamu , Osaki Hironobu , Sato Hiromichi
Published: March 2009

In the primary visual cortex (V1), the response of a neuron to stimulation of its classical receptive field (CRF) is suppressed by concurrent stimulation of the extraclassical receptive field (ECRF), a phenomenon termed ‘surround suppression’. It is also known that the orientation tuning of V1 neurons becomes sharper as the size of the stimulus increases beyond the CRF. However, there have been few quantitative investigations of the relationship between sharpening of orientation tuning and surround suppression. We examined this relationship in 73 V1 neurons recorded from anesthetized and paralysed cats using sinusoidal grating patches as stimuli. We found that sharpening of orientation tuning was significantly correlated with the strength of surround suppression for large stimuli that cover both CRF and ECRF. Furthermore, simulation analysis using a variety of tuning widths and most suppressive orientation of orientation‐tuned surround suppression demonstrated that broadly orientation‐tuned surround suppression sharpens orientation tuning for large gratings without shift in optimal orientation. Our findings suggest that one of the functional roles of surround suppression in V1 is enhancement of orientation discrimination for large and uniformly patterned objects.
Preference judgements involve a network of structures within frontal, cingulate and insula cortices
Authors: Chaudhry Amir M. , Parkinson John A. , Hinton Elanor C. , Owen Adrian M. , Roberts Angela C.
Published: March 2009

Environmental stimuli constantly compete for human attention and in many cases decisions are made based on the affective meaning they convey. Although the network of structures involved in processing affective value has been well described, the specific contribution of these structures to the process by which affective value guides decision making is less well understood and is the focus of the present study. Thus, subjects read descriptions of individually tailored holidays, varying in incentive value and then made preference judgements, cognitive judgements or no decision. Choices made from an affective perspective, compared with those made from a cognitive perspective, activated a region of the anterior insula/operculum and also the anterior cingulate cortex. Furthermore, activity in perigenual, anterior cingulate cortex was correlated with subjective ratings of incentive value. In contrast, medial orbitofrontal cortex (OFC) and a region of posterior ventrolateral prefrontal cortex (PFC), bordering on the insula, were found to be more active when affective stimuli guided response selection than when no selection was made. However, only the activity in the ventrolateral PFC was specific to response selection based on affective compared with cognitive judgements. It is proposed that the necessary introspection required to make subjective preference judgements is provided by the insula and cingulate cortices, while the medial OFC and posterior ventrolateral PFC/insula cortices contribute to stimulus evaluation and motivational aspects of response selection, respectively.
Deficient responses from the lateral geniculate nucleus in humans with amblyopia
Authors: Hess Robert F. , Thompson Benjamin , Gole Glen , Mullen Kathy T.
Published: March 2009

Amblyopia or lazy eye is the most common cause of uniocular blindness in adults. It is caused by a disruption to normal visual development as a consequence of unmatched inputs from the two eyes in early life, arising from a turned eye (strabismus), unequal refractive error (anisometropia) or form deprivation (e.g. cataract). Animal models based on extracellular recordings in anesthetized animals suggest that the earliest site of the anomaly in the primate visual pathway is the primary visual cortex (corresponding to the striate cortex, cytoarchitectonic area 17 and area V1), which is where inputs from the two eyes are first combined in an excitatory fashion, whereas more distal and monocular processing structures such as the retina and lateral geniculate nucleus (LGN) are normal. Using high‐field functional magnetic resonance imaging in a group of human adults with amblyopia, we demonstrate that functional deficits are first observable at a thalamic level, that of the LGN. Our results suggest the need to re‐evaluate the current models of amblyopia that are based on the assumption of a purely cortical dysfunction, as well as the role for the LGN in visual development.
Microbial biodiversity of thermophilic communities in hot mineral soils of Tramway Ridge, Mount Erebus, Antarctica
Authors: Soo Rochelle M. , Wood Susanna A. , Grzymski Joseph J. , McDonald Ian R. , Cary S. Craig
Published: March 2009

Tramway Ridge, located near the summit of Mount Erebus in Antarctica, is probably the most remote geothermal soil habitat on Earth. Steam fumaroles maintain moist, hot soil environments creating extreme local physicochemical differentials. In this study a culture‐independent approach combining automated rRNA intergenic spacer analysis (ARISA) and a 16S rRNA gene library was used to characterize soil microbial (Bacterial and Archaeal) diversity along intense physicochemical gradients. Statistical analysis of ARISA data showed a clear delineation between bacterial community structure at sites close to fumaroles and all other sites. Temperature and pH were identified as the primary drivers of this demarcation. A clone library constructed from a high‐temperature site led to the identification of 18 novel bacterial operational taxonomic units (OTUs). All 16S rRNA gene sequences were deep branching and distantly (85–93%) related to other environmental clones. Five of the signatures branched with an unknown group between candidate division OP10 and Chloroflexi. Within this clade, sequence similarity was low, suggesting it contains several yet‐to‐be described bacterial groups. Five archaeal OTUs were obtained and exhibited high levels of sequence similarity (95–97%) with Crenarchaeota sourced from deep‐subsurface environments on two distant continents. The novel bacterial assemblage coupled with the unique archaeal affinities reinvigorates the hypotheses that Tramway Ridge organisms are relics of archaic microbial lineages specifically adapted to survive in this harsh environment and that this site may provide a portal to the deep‐subsurface biosphere.
Impact of Collimonas bacteria on community composition of soil fungi
Authors: Höppener‐Ogawa Sachie , Leveau Johan H. J. , Hundscheid Maria P. J. , Van Veen Johannes A. , De Boer Wietse
Published: March 2009

The genus Collimonas consists of soil bacteria that have the potential to grow at the expense of living fungal hyphae. However, the consequences of this mycophagous ability for soil fungi are unknown. Here we report on the development of fungal communities after introduction of collimonads in a soil that had a low abundance of indigenous collimonads. Development of fungal communities was stimulated by addition of cellulose or by introducing plants (Plantago lanceolata). Community composition of total fungi in soil and rhizosphere and of arbuscular mycorrhizal fungi in roots was examined by PCR‐DGGE. The introduction of collimonads altered the composition of all fungal communities studied but had no effects on fungal biomass increase, cellulose degrading activity or plant performance. The most likely explanation for these results is that differences in sensitivity of fungal species to the presence of collimonads result in competitive replacement of species. The lab and greenhouse experiments were complemented with a field experiment. Mesh bags containing sterile sand with or without collimonads were buried in an ex‐arable field and a forest. The presence of collimonads had an effect on the composition of fungi invading these bags in the ex‐arable site but not in the forest site.
Mapping field‐scale spatial patterns of size and activity of the denitrifier community
Authors: Philippot Laurent , Čuhel Jiri , Saby Nicolas P.A. , Chèneby Dominique , Chroňáková Alicia , Bru David , Arrouays Dominique , Martin‐Laurent Fabrice , Šimek Miloslav
Published: March 2009

There is ample evidence that microbial processes can exhibit large variations in activity on a field scale. However, very little is known about the spatial distribution of the microbial communities mediating these processes. Here we used geostatistical modelling to explore spatial patterns of size and activity of the denitrifying community, a functional guild involved in N‐cycling, in a grassland field subjected to different cattle grazing regimes. We observed a non‐random distribution pattern of the size of the denitrifier community estimated by quantification of the denitrification genes copy numbers with a macro‐scale spatial dependence (6–16 m) and mapped the distribution of this functional guild in the field. The spatial patterns of soil properties, which were strongly affected by presence of cattle, imposed significant control on potential denitrification activity, potential N2O production and relative abundance of some denitrification genes but not on the size of the denitrifier community. Absolute abundance of most denitrification genes was not correlated with the distribution patterns of potential denitrification activity or potential N2O production. However, the relative abundance of bacteria possessing thenosZgene encoding the N2O reductase in the total bacterial community was a strong predictor of the N2O/(N2 + N2O) ratio, which provides evidence for a relationship between bacterial community composition based on the relative abundance of denitrifiers in the total bacterial community and ecosystem processes. More generally, the presented geostatistical approach allows integrated mapping of microbial communities, and hence can facilitate our understanding of relationships between the ecology of microbial communities and microbial processes along environmental gradients.
eGOVERNMENT AND THE TRANSFORMATION AGENDA
Authors: FOLEY PAUL , ALFONSO XIMENA
Published: March 2009

Government policy‐making emphasis worldwide is moving increasingly to how ICT can be used to achieve efficiency savings (Gershon 2004) or to transform activities (Cabinet Office; Transformational Government 2005). The role of ICT in achieving efficiency benefits or supporting transformational change is almost universally accepted by policy‐makers, despite the fact that little robust evidence exists.

eGovernment evaluation methodologies are reviewed and evidence is provided in this paper to demonstrate that transformational eGovernment projects produce greater benefits than other types of initiatives. The level of benefits for different groups of beneficiaries is examined. A key factor determining benefits and impact of any project is the number of users of the service and/or the frequency of use of a system.
GOVERNINGWITHOUTGOVERNMENT? THE PRIVATE GOVERNANCE OF FOREST CERTIFICATION IN SWEDEN
Authors: HYSING ERIK
Published: March 2009

The role and capacity of the state are changing. Some researchers argue that the state is transforming, strategically adapting to new circumstances, while others see a development of governing arrangements that are autonomous from the state, governing ‘without’ government. This article assesses the governing without government thesis through the case of forest certification introduced in Sweden in the late 1990s. This is a case of private governance, the governing capacity of which is based on voluntary self‐regulation rather than government authority, seemingly a prime example of governing without government. The results show that government nonetheless is involved with forest certification through governance‐oriented modes of governing: enabling and influencing the arrangements. Thus, what appeared to be a prime example of governing ‘without’ government is better understood as governing ‘with’ government.
Industrial Diversity, Trade Patterns, and Productivity Convergence
Authors: Stehrer Robert , Woerz Julia
Published: March 2009

Recent developments in economic integration show rather diverse patterns of integration in the world economy. Some countries remain predominantly in the low‐tech industries whereas other countries succeed in becoming competitive in high‐tech industries as well. The authors postulate that a country positioning itself at the lower end of the spectrum of high‐tech industries is more favorable to its long‐term development than aiming at the upper end of low‐tech industries. They argue that countries which specialize in the lower end of the medium–high‐tech activities are rewarded by faster productivity increases also in the upper end of the high‐tech industries. In contrast, early specialization in medium–low‐tech branches yields positive spillovers, mainly in the low‐tech sector, which is not conducive to increasing activity in high‐tech industries. The authors sketch a theoretical outline of this idea and present econometric results, including four aggregate manufacturing branches across 37 countries.
Auditory processing in developmental dyslexia: An exploratory study of an auditory and visual matching training program with Swedish children with developmental dyslexia
Authors: TÖRMÄNEN MINNA R. K. , TAKALA MARJATTA
Published: March 2009

This study examined whether training using a nonverbal auditory‐visual matching task had a remedial effect on reading skills in developmental dyslexia. The pretest/post‐test design was used with Swedish children (N= 41), between the ages of 7 and 12. Training comprised twice‐weekly sessions of 15 minutes, over eight weeks. There was an improvement in auditory‐visual matching during the training period. There were also improvements in some reading test scores, especially in reading nonsense words and in reading speed. These improvements in tasks which are thought to rely on phonological processing suggest that such reading difficulties in dyslexia may stem in part from more basic perceptual difficulties, including those required to manage the visual and auditory components of the decoding task. The utility of the concept of auditory structuring is discussed in relation to auditory and phonological processing skills when a child learns to read.
Women's well‐being: The role of individual differences
Authors: DIJKSTRA PIETERNEL , BARELDS DICK P. H.
Published: March 2009

The present study examined the relationship between physical and psychological well‐being, personality characteristics and demographic variables related to motherhood, work and marital status in a sample of 3,723 Dutch women. Analysis revealed several interesting relationships. First, whereas neuroticism was negatively related to both physical and psychological well‐being, extraversion was positively related to well‐being. Second, a clear positive relationship emerged between work participation and both types of well‐being. Results are discussed in terms of the vulnerability stress model.