bluuebunny/crossref_metadata_2025 huggingface dataset:
Patterns of Dormancy and Florogenesis in Herbaceous Perennial Plants: Environmental and Internal Regulation
Authors: Kamenetsky Rina
Published: October 2009

Plant evolution in climatic areas with marked seasonal changes has led to species adaptation to periods of high and low temperatures and drought and to significant changes in their morphological structure and annual developmental cycles. One characteristic of these adaptations is the state of dormancy, in which the plants do not exhibit any visible external growth. This paper reviews dormancy and florogenesis as main components of the survival strategies of perennial herbaceous plants. Summer dormancy protects plants from negative effects of water deficit and high temperatures on vegetative and reproductive organs, and forces plant species to schedule their active development in more favorable seasons. Mechanisms of summer survival vary among species and provide different modes of adaptation to harsh environments. The interrelationship between florogenesis and dormancy is most probably controlled in meristems, where the survival strategy of the plant, including vegetative growth, flowering, drought tolerance, and formation of storage organs, is determined. Mechanisms by which summer dormancy confers summer drought survival warrant further investigation for improving agronomic and environmental traits of perennial plants.
Identification and Measurement of Summer Dormancy in Temperate Perennial Grasses
Authors: Norton Mark R. , Volaire F. , Lelièvre F. , Fukai S.
Published: October 2009

There is an apparent increase in frequency of prolonged droughts in regions with Mediterranean climates. This has rekindled interest in the summer dormancy trait for improving drought resistance of temperate perennial pasture grasses. In orchardgrass (Dactylis glomerata L.), tall fescue [Lolium arundinaceum (Schreb.) Darbysh.], and phalaris (Phalaris aquatica L.), identification of the three common drought resistance traits of vascular plants, dehydration avoidance (or delay), dehydration tolerance, and summer dormancy, is often confused. Summer dormancy, the least common of these traits, is found in cool‐season grasses from semiarid and arid Mediterranean climates and provides an enhanced level of drought resistance. It is best measured in field‐grown plants previously exposed to low winter temperatures and short photoperiods. Those perennial grasses not exhibiting summer dormancy survive drought by avoiding and/or tolerating dehydration and express this as a response to water deficit irrespective of the season. Here we review three summer water‐supply environments, full irrigation, midsummer storm, and summer drought, for their precision and repeatability in measuring dormancy. Full irrigation and midsummer storm can be recommended, but measurement of dormancy under prolonged drought caused inconsistencies.
Stress Tolerance and Persistence of Perennial Grasses: The Role of the Summer Dormancy Trait in Temperate Australia
Authors: Nie Zhongnan , Norton M. R.
Published: October 2009

The significantly lower annual rainfall experienced in Australia over the past decade together with projections of long‐term climate change has placed increased emphasis on the use of pasture plants with superior tolerance to environmental stress, particularly drought, to ensure persistence for the grazing industries. Summer dormancy is one of the more important traits that grasses have to adapt to environments where there is little, variable, or no summer rainfall. In this article, the role that the summer dormancy trait has played in enhancing the survival of temperate perennial grasses in Australia is reviewed with special reference to orchardgrass (cocksfoot; Dactylis glomerata L.) and tall fescue [Lolium arundinaceum (Schreb.) Darbysh.]. The performance of cultivars and populations with this trait is assessed in comparison to germplasm without the trait. Other major factors such as the contribution of rooting depth to stress tolerance and their possible relationship with summer dormancy are documented and evaluated. Current knowledge of the physiological basis by which summer dormancy improves survival of summer drought is also summarized.
Breeding and Use of Summer‐Dormant Grasses in Southern Australia, with Special Reference to Phalaris
Authors: Culvenor Richard A.
Published: October 2009

The adaptation of introduced perennial grasses in southern Australia expanded with the discovery of the Mediterranean grass phalaris (Phalaris aquatica L.) as a valuable pasture species, and the introduction of Mediterranean ecotypes of orchardgrass (Dactylis glomerata L.), and tall fescue [Lolium arundinaceum (Schreb.) Darbysh.] displaying summer dormancy. In contrast, native grasses of agricultural importance appear to have little or no endogenous summer dormancy. A brief history of cultivar development from Mediterranean germplasm is presented. Recent developments include cultivars based on summer‐dormant subsp. hispanica orchardgrass and the release of Mediterranean‐type cultivars of tall fescue. Phalaris depends on a deep root system and summer dormancy for its summer survival. Cultivars based on more summer‐dormant Moroccan ecotypes have been developed for drier environments. Work to improve phalaris for hotter, summer‐dominant rainfall areas is being extended to enhance the range of perennials for the cropping zone. In addition to ecotype evaluation, breeders should employ recurrent selection in cultivars and populations such as those developed recently for low‐ to medium‐rainfall areas in orchardgrass and tall fescue.
Summer Dormancy in Australian Perennial Grasses: Historical Background, a Simulation Study, and Current Research
Authors: Clark Steve , Harris Carol
Published: October 2009

The need for summer‐dormant, perennial, temperate grass cultivars in Australia has increased since European‐style agriculture arrived and began to push further inland into the drier pastoral zones. Early attempts to breed cultivars for marginal environments resulted in a few notable successes, but many failures resulted due to poor marketing, a lack of understanding of the environment, and economic downturns. A new spur to summer‐dormant cultivar development is climate change with predictions of lower and more erratic rainfall and higher temperatures. This paper discusses briefly the history of temperate perennial grass breeding as it relates to summer‐dormant cultivar development. Two case studies are presented. Simulations of higher input summer‐dormant grass pastures vs. unimproved annual grass pastures are examined for long‐term production and profitability under current and predicted climate scenarios. The current orchardgrass (syn. cocksfoot, Dactylis glomerata L.) and tall fescue [Lolium arundinaceum (Schreb.) Darbysh. = Schedonorus arundinaceus (Schreb.) Dumort.] breeding and commercialization programs are described.
Modeling Tiller Density, Growth, and Yield of Mediterranean Perennial Grasslands with STICS
Authors: Ruget Françoise , Satger Sylvain , Volaire Florence , Lelièvre François
Published: October 2009

A generic crop model (STICS) was adapted (STICS–Grassland) to model growth, yield, and environmental impacts of grasslands in France. It is a semimechanistic model combining equations of physiological processes and mathematical relationships between processes in a daily time step. The Information et Suivi Objectif des Prairies (ISOP; Grassland Information and Objective Survey) application was developed to estimate and map the real‐time status of grass growth and forage production in the 200 forage regions of France, to help decision makers anticipate forage availability in case of severe deficits. Initially, the model could not simulate long, severe droughts typical of Mediterranean regions when plant and tiller densities are significantly reduced. A tiller density module models the dynamics of tiller death during droughts. Since STICS is based on the concept of a mean plant (tiller) covering the whole field, variability was introduced through a γ law distribution of transpiration deficit by tiller, a threshold value imposing desiccation, and death to tillers reaching this level. Its second part generates incomplete or total recovery of tiller density through new tillering in the next wet season. Species and contrasting groups of cultivars within species can be characterized with a limited number of parameters.
Current and Potential Development of Perennial Grasses in Rainfed Mediterranean Farming Systems
Authors: Lelièvre François , Volaire Florence
Published: October 2009

Past and recent development of perennial grasses in the rainfed Euro‐Mediterranean region is reviewed concerning climatic constraints and main types of farming systems. The few Mediterranean cultivars that are registered and available are used for livestock production and cover crops only in subtemperate areas. These cultivars are adapted where annual rainfall exceeds 500 mm and accumulated water deficit from May to September is <800 mm. For the future, grass–legume mixtures need to be developed to meet the contrasting situations of livestock production and environmental use, with both functions contributing to farm income through the market and from public subsidies. Concern for environmental uses of perennial grasses raises interest in new germplasm that could accelerate cultivar breeding and seed production. Research programs should ensure a diversification of available germplasm in the principal forage species for phenology, drought tolerance, summer dormancy levels, and dehydration tolerance.
Summer Dormancy in Orchardgrass: Evaluation and Characterization through Ecophysiological and Genetic Studies
Authors: Shaimi Naima , Kallida Rajae , Volaire Florence , Faiz Chaouki Al
Published: October 2009

Climatic change manifested by increasing summer drought necessitates the development of drought‐tolerant forage grass cultivars. Summer dormancy is a major trait conferring drought survival and autumn recovery of perennial grasses in Mediterranean areas. Moroccan ecotypes of orchardgrass (Dactylis glomerata L.) expressed 67% greater degree of summer dormancy than tested cultivars except the highly dormant ‘Kasbah.’ Furthermore, summer dormancy was highly correlated with perenniality (r = 0.63, P < 0.01). However, summer dormancy was associated with low productivity. A breeding program was started to develop productive orchardgrass cultivars with high summer dormancy. Hybrids between high‐ and low‐dormancy cultivars produced offspring with combinations of enhanced dormancy and biomass production indicating potential for breaking the negative dormancy‐yield association. For example, Kasbah (dormant) × ‘Medly’ (summer‐active) hybrids were 57% more dormant than Medly and 32% higher yielding than Kasbah. Genetic analysis of heritability and molecular markers will provide more information on the genetic control of summer dormancy. Results of crosses between contrasting populations of orchardgrass indicate potential for combining the desirable traits of summer dormancy and high annual herbage yield into an eventual cultivar.
Breeding Summer‐Dormant Grasses for the United States
Authors: Hopkins A. A. , Bhamidimarri S.
Published: October 2009

Summer dormancy can lead to increased drought tolerance and persistence in cool‐season grasses. Here we describe efforts to develop summer‐dormant cultivars in the United States. Summer‐dormant grasses are generally well adapted to the Southern Plains but have poor persistence as well as low productivity east and north of this region because of limited winter hardiness and other factors. This limited geographic adaptation is thought to be due to germplasm background rather than the summer dormancy trait. Depending on the target environment, improved cultivars could be developed by selecting within existing summer‐dormant material or by crossing the trait into adaptive germplasm. Difficulties in phenotyping summer dormancy, and in some instances fertility barriers across germplasm sources, will need to be overcome to utilize the latter approach.
Fitting Germplasm Types of Tall Fescue and Orchardgrass to Different Cropping Environments of the Mediterranean Region
Authors: Pecetti L. , Annicchiarico P. , Porqueddu C. , Khedim A. , Abdelguerfi A.
Published: October 2009

Understanding of adaptation targets, selection environments, genetic resources, and plant types is required in breeding tall fescue [Lolium arundinaceum (Schreb.) S.J. Darbysh.] and orchardgrass (Dactylis glomerata L.) for Mediterranean environments prone to drought stress. Fourth‐year forage yield of seven orchardgrass and five fescue cultivars grown in Algeria and Sardinia revealed (i) crossover cultivar × location interaction in orchardgrass, with dormant germplasm performing best in the drier Algerian site, and nondormant Mediterranean material performing best in Sardinia; and (ii) the advantage of tall fescue over orchardgrass in both sites. Yield of Algerian populations of orchardgrass and tall fescue grown in Algeria was generally lower than the best control (‘Flecha’ tall fescue). Other studies in Italy showed (i) the possibility to select orchardgrass from Mediterranean germplasm that combines summer survival under moderate stress with response to summer rain events; (ii) the nil effect in a Mediterranean site, and the slightly positive effect in a subcontinental climate site of endophyte infection on tall fescue survival; and (iii) the adaptation of Mediterranean and Continental fescue germplasm to their respective climatic areas.
Bioenergy II: Acid Diphosphates as Catalysts for the Production of Methyl and Ethyl Esters from Vegetable Oils
Authors: Marciniuk Letícia Ledo , Garcia Camila Martins , Muterle Roberto Bineli , Schuchardt Ulf
Published: October 2009

Acidic lanthanum and aluminum diphosphates were prepared and characterized (surface area, XRD, FT-IR, 31P-NMR and 27Al-NMR). These materials were used as catalyst for the esterification of oleic acid and transesterification of soybean oil. Under optimized conditions the methyl and ethyl ester yields were above 95%. Although the catalysts are recyclable, they slowly lost their catalytic activities, due to leaching of the phosphate.
Removal of Malachite Green from Aqueous Solutions by Perlite
Authors: Govindasamy Vijayakumar , Sahadevan Renganathan , Subramanian Sivanesan , Mahendradas Dharmendira Kumar
Published: October 2009

Perlite was utilized as an adsorbent for the removal of malachite green from their aqueous solution. The effects of the initial dye concentration, contact time, adsorbent dose, pH, and temperature were studied for the adsorption of malachite green in batch mode. The dye adsorption equilibrium was rapidly attained after 40 min of contact time. Adsorbent was characterized by FTIR, XRD and SEM. The Langmuir and Freundlich isotherm described the adsorption data over the concentration range (20  100 mg/L). The rate parameters of the intra particle diffusion were calculated and compared to identify the adsorption mechanisms. The thermodynamic parameters such as entropy change, enthalpy change, and energy of adsorption were calculated to know the nature of adsorption. The negative values of energy of adsorption and the positive values of enthalpy change suggested that the adsorption process is spontaneous and exothermic. Kinetic studies showed that the adsorption process obeyed the pseudo first-order kinetic model.
Temperature Effect on Hydrogen Production from Reactions between Ethanol and Steam in the Presence of Pd-Ru/Nb2O5-TiO2 Catalyst
Authors: Alonso Christian G. , Furtado Andréia C. , Cantão Mauricio P. , dos Santos Onélia A. A. , Fernandes-Machado Nadia Regina C
Published: October 2009

Temperature effect on the performance of Pd-Ru/Nb2O5-TiO2 (PRNT) catalyst on hydrogen production from reactions between ethanol and steam was evaluated. Parallel reactions occurred in all conditions studied according to what was observed by the presence of H2, CO2, CH4, CO, C2H4, C2H6, C2H4O and (C2H5)2O. While at 300 °C the process seems to be dominated by ethanol dehydrogenation and decomposition, at 375 °C dehydration it seems to compete for active sites with ethanol dehydrogenation and decomposition reactions. At 450 °C there is a dehydration reaction to ethane, basically competing at the same level with ethanol dehydrogenation decomposition reactions. Hydrogen production on PRNT catalyst is maximized at 300 °C.
Comment on Edlin and Jaffee: From Banking Crisis to Currency Crisis
Authors: Thornton John
Published: October 2009

A tax on excess reserves would worsen the banking crisis and could lead to a run on the dollar, according to John Thornton.
The Use of Earnings Capitalization in the Valuation of Growing Firms
Authors: Lippitt Jeffrey W , Lewis Eric E , Burress Joanne
Published: October 2009

This paper presents two new models for valuing closely held businesses that are experiencing growth. These models supplement the existing growth model and incorporate alternate assumptions regarding the character of future growth.
Forecasting the Periodic Net Discount Rate with Genetic Programming
Authors: Wagner Neal F , Thompson Mark A
Published: October 2009

This paper examines the periodic net discount rate using genetic programming (GP) techniques to build better short-term forecasts. Standard GP techniques require human judgment as to which data window to use, which may be problematic due to structural breaks and persistence (or long memory) in the net discount rate. We use a recently developed extension of GP to overcome this problem. While our results show no significant out-of-sample forecast improvement relative to the linear alternative or random walk model over the full sample, they do provide evidence as to the stochastic nature of the net discount rate considering the AR(3) model yielded lower forecasting errors in the post-1982 sample.
Modeling Catalytic Combustion of Methane During the Warm-Up Period of the Converter
Authors: Chauhan Sanchita , Kumar Deepak , Srivastava V. K.
Published: October 2009

Modeling for hydrocarbon methane was carried out during the warm-up period. A one-dimensional model based on its catalytic combustion reaction was formed. The mass and energy balance equations derived for the gas and the solid phase are a set of partial differential equations. All these equations are solved using Backward Implicit Scheme. The variation of gas concentration, temperature and solid temperature along the length of the converter during the warm-up period was analysed. Also, the effects on time while changing various parameterslike inlet gas temperature, catalyst loading, surface area, and converter lengthfor methane conversion, were studied.
Heat Transfer and Fluid Flow Analysis of Power Transformer's Cooling System Using CFD Approach
Authors: Nabati Hamid , Mahmoudi Jafar , Ehteram Ali
Published: October 2009

This paper presents the results of numerical modeling of temperature distribution and flow pattern in a block radiator used in power transformer cooling system. Each block radiator consists of eighteen plane radiators which are parallel together and a typical power transformer (like a 30MVA) has 6 radiator blocks in each side which means it has 12 blocks totally. The numerical study using fluent software has been conducted to find the explanation of low cooling efficiency in this especial power transformer currently used in industry. Our main desire is the study of relation between radiator block characteristics and cooling behavior of system which can be used for its optimization in the future studies. The results indicate that recirculation occurs whenever pressure increase at the end of a radiator block that consequently prevents the enough oil flow through the last radiator of block. Experimental data taken from company and technical data extracted from transformer documents have been used for model calibration and results verification.
Resource Specialization and Economic Performance: A Canadian Case Study, 1970–2005
Authors: Keay Ian
Published: October 2009

The main objective of this paper is to identify the channels through which specialization in resource-intensive production had an impact on the performance of the aggregate Canadian economy over the 1970–2005 period. As a whole, the Canadian resource sector appears to have been making substantial direct and indirect contributions to aggregate economic performance since 1970, and we can find little evidence of strong or consistent crowding-out effects. There are, however, some important caveats. In particular, the significance of the resource sector's contributions was strongly influenced by the key role played by the energy extraction industries.
An Analysis of Effective Marginal Tax Rates in Quebec
Authors: Duclos Jean-Yves , Fortin Bernard , Fournier Andrée-Anne
Published: October 2009

This article draws a portrait of effective marginal tax rates (EMTRs) on labour income in Quebec. It aims to improve the understanding of the impact of tax policy on the behaviour of economic agents. Using an accounting microsimulation model that reproduces the system of taxes and transfers in 2002 in Quebec, we measure the EMTRs that result from the interaction of the mechanisms of income taxation and redistribution. Moreover, we evaluate the distribution of EMTRs in the population. The analysis of EMTRs shows, inter alia, that family policy, whose assistance is targeted toward low-income families, generates high levels of EMTRs ascribable to the generally fast reduction of transfers as income increases. More than a quarter of heads of single-parent households face an EMTR that can reach, and even exceed, 80 percent. As for two-parent families, they mostly face EMTRs of around 50 percent. We show the importance of accounting for EMTR heterogeneity, both with respect to types of families and levels of incomes, as well as evaluating the variability of EMTRs in the population.
The Current Status of the Publishing Industry in China
Authors: Sun Ji , Yang Yang , Mao Meng
Published: October 2009

This article retrospectively analyzes the current situation of the development of China's publishing industry and illustrates the scale, structure, new publication patterns, and characteristics of this industry. The results reveal that the continuous development of China's publishing industry is manifested in the solid growth of traditional publishing and the rapid growth of non-paper-based publications. Digital and network technologies have become the critical foundations of the publishing industry, facilitating the expansion of the traditional publishing industry and the renewal of traditional productivity. Moreover, the dominance of books giving way to a more diversified publishing pattern. An industry chain primarily based on provinces is under construction, and the leading publishers are beginning to orient toward industrial development. The basic formation of a dual-capital system, funded both federally and privately, has accelerated the process of publishing socialization. In contrast to the previous system under the planned economy, this new system is demarcated into missions for information dissemination and the pursuit of profit, a fundamental change known as the “dichotomy pattern” that powerfully promotes the prosperity and advancement of China's publishing industry.
The role of resources and architecture in modeling floral variability for the monoecious amphicarpic Emex spinosa (Polygonaceae)
Authors: Ortiz Pedro L. , Berjano Regina , Talavera María , Arista Montserrat
Published: October 2009

Determining the sources of floral variation is crucial to the understanding of floral evolution. Architectural effects and phenotypic plasticity in development can play an important role in intraplant floral variation, giving rise to gender dimorphism or sexual specialization. Amphicarpic plants have another source of floral variation that could also be influenced by positional effects. We studied the effects of resource availability and architecture in intraplant floral variability in two ecotypes of the amphicarpic Emex spinosa. Male flowers were smaller than females, irrespective of position or resource availability. Emex spinosa shows gender dimorphism not influenced by positional effects. Flower size differences among positions were mainly due to architecture, because the effects of resources on flower size were minimal. Architectural effects caused a decrease in female flower size from ground to apical positions but an increase in most male traits that resulted in sexual specialization at the end of flowering. In general, the ecotypes were similarly affected by resources or architecture. Differences between subterranean and aerial female flowers seem also to be a consequence of architecture. Our results contribute to the evidence that resource limitation is an overestimated effect and that architectural effects must be considered in studies of floral or fruit variation.
Reproductive short‐shoots of Ginkgo biloba: A quantitative analysis of the disposition of axillary structures
Authors: Christianson Michael L. , Jernstedt Judith A.
Published: October 2009

Ginkgo biloba, the only living representative in an otherwise extinct clade, is of pivotal importance to understanding seed plant phylogeny. Although G. biloba and its fossil relatives have been studied for over two centuries, there are both gaps and contradictions in the information available. We present data documenting the distributions of strobili and consider what an understanding of the disposition of strobili along short‐shoots in Ginkgo adds to knowledge of the evolution of reproductive structures in seed plants in general. The megasporangiate strobili are found at and around the boundary between bracts and foliage leaves, while the expanse of microsporangiate strobili centers on the fifth bract back from that boundary. Quantitative analysis of the locations of the strobili along the short‐shoot finds that increases in numbers of strobili are the result of recruitment of adjacent axils into morphogenetic activity. Gaps in the series of strobili are exceedingly rare. Further, while increased numbers of megasporangiate strobili arise from the symmetrical addition of axils into the fertile zone, increased numbers of microsporangiate strobili arise from a distinctly asymmetrical, basipetally biased, addition of axillary positions. This accurate morphological framework should orient molecular genetic studies that probe gymnosperm development itself or that consider gymnosperms as the proximate sources of gene expression redeployed in the origin of the angiosperm flower.
Kin recognition: Competition and cooperation in Impatiens (Balsaminaceae)
Authors: Murphy Guillermo P. , Dudley Susan A.
Published: October 2009

The ability to recognize kin is an important element in social behavior and can lead to the evolution of altruism. Recently, it has been shown that plants are capable of kin recognition through root interactions. Here we tested for kin recognition in a North American species of Impatiens that has a high opportunity of growing with kin and responds strongly to aboveground competition. We measured how the plants responded to the aboveground light quality cues of competition and to the presence of root neighbors and determined whether the responses depended on whether the neighbors were siblings or strangers. The study families were identified by DNA sequencing as members of the same species, provisionally identified as Impatiens pallida (hereafter I. cf. pallida). We found that I. cf. pallida plants were capable of kin recognition, but only in the presence of another plant's roots. Several traits responded to relatedness in shared pots, including increased leaf to root allocation with strangers and increased stem elongation and branchiness in response to kin, potentially indicating both increased competition toward strangers and reduced interference (cooperation) toward kin. Impatiens cf. pallida responded to both competition cues simultaneously, with the responses to the aboveground competition cue dependent on the presence of the belowground competition cue.
Fragment quality and matrix affect epiphytic performance in a Mediterranean forest landscape
Authors: Belinchón Rocío , Martínez Isabel , Otálora Mónica A. G. , Aragón Gregorio , Dimas Jesús , Escudero Adrián
Published: October 2009

Destruction and fragmentation of habitats represent one of the most important threats for biodiversity. Here, we examined the effects of fragmentation in Mediterranean forests on the epiphytic lichen Lobaria pulmonaria (Lobariaceae). We tested the hypothesis that not only the level of fragmentation affects L. pulmonaria populations, but also the quality of the habitat and the nature of the surrounding matrix affect them. The presence and abundance of the lichen was recorded on 2039 trees in a total of 31 stands. We recorded habitat quality and landscape variables at three hierarchical levels: tree, plot, and patch. We found that L. pulmonaria tends to occur in trees with larger diameters in two types of surveyed forests. In Quercus pyrenaica patches, the mean diameter of colonized trees was smaller, suggesting the importance of bark roughness. Factors affecting the presence and cover of the lichen in each type of forest were different. There was a strong positive influence of distance from a river in beech forests, whereas proximity to forest edge positively affected in oak forests. The influence of the surrounding matrix was also an important factor explaining the epiphytic lichen abundance.
The maintenance of mixed mating by cleistogamy in the perennial violet Viola septemloba (Violaceae)
Authors: Winn Alice A. , Moriuchi Ken S.
Published: October 2009

The production of both potentially outcrossed (chasmogamous) and obligately self‐fertilized (cleistogamous) flowers presents a clear exception to the prediction that the only evolutionarily stable mating systems are complete selfing and complete outcrossing. Although cleistogamy has evolved repeatedly, the reason for its stability is not known for any species. We tested the hypothesis that the production of cleistogamous and chasmogamous flowers by a perennial violet constitutes adaptive phenotypic plasticity. We manipulated the season of flowering for each flower type and determined fruit set and the germination percentage of seeds produced by cleistogamous and chasmogamous flowers to test the hypothesis that adaptive plastic response to seasonal environmental variation makes mixed mating stable. Cleistogamous flowers had greater fruit set in all seasons and produced seeds with germination percentages as great as or greater than those from chasmogamous flowers. The consistent advantage of cleistogamous flowers is clearly not consistent with a role of adaptive plastic response to seasonal variation. The biomass cost of seed production by chasmogamous flowers was nearly three times that for cleistogamous flowers. Explaining why chasmogamous flower have not been eliminated by natural selection requires that this difference be balanced by an advantage to chasmogamous flowers that has not yet been identified.
Mycorrhizal diversity in Apostasia (Orchidaceae) indicates the origin and evolution of orchid mycorrhiza
Authors: Yukawa Tomohisa , Ogura‐Tsujita Yuki , Shefferson Richard P. , Yokoyama Jun
Published: October 2009

We demonstrated that “orchid mycorrhiza,” a specialized mycorrhizal type, appeared in the common ancestor of the largest plant family Orchidaceae and that the fungal partner shifted from Glomeromycota to a particular clade of Basidiomycota in association with this character evolution. Several unique mycorrhizal characteristics may have contributed to the diversification of the family. However, the origin of orchid mycorrhiza and the diversity of mycobionts across orchid lineages still remain obscure. In this study, we investigated the mycorrhizae of five Apostasia taxa, members of the earliest‐diverging clade of Orchidaceae. The results of molecular identification using nrDNA ITS and LSU regions showed that Apostasia mycorrhizal fungi belong to families Botryobasidiaceae and Ceratobasidiaceae, which fall within the order Cantharellales of Basidiomycota. Most major clades in Orchidaceae also form mycorrhizae with members of Cantharellales, while the sister group and other closely related groups to Orchidaceae (i.e., Asparagales except for orchids and the “commelinid” families) ubiquitously form symbioses with Glomeromycota to form arbuscular mycorrhizae. This pattern of symbiosis indicates that a major shift in fungal partner occurred in the common ancestor of the Orchidaceae.
Authoring Systems Delivering Reusable Learning Objects
Authors: Schreurs Jeanne , Dalle Rik , Sammour George Nicola
Published: October 2009

A three layer e-learning course development model has been defined based on a conceptual model of learning content object. It starts by decomposing the learning content into small chunks which are initially placed in a hierarchic structure of units and blocks. The raw content components, being the atomic learning objects (ALO), were linked to the blocks and are structured in the database. We set forward a dynamic generation of LO's using re-usable e-learning raw materials or ALOâ??s

In that view we need a LO authoring/ assembling system fitting the requirements of interoperability and reusability and starting from selecting the raw learning content from the learning materials content database. In practice authoring systems are used to develop e-learning courses. The company EDUWEST has developed an authoring system that is database based and will be SCORM compliant in the near future.
Mobile Game Development for Multiple Devices in Education
Authors: Lavin-Mera Pablo , Torrente Javier , Moreno-Ger Pablo , Vallejo Pinto Jose Angel , Fernández-Manjón Baltasar
Published: October 2009

Mobile learning and educational gaming are two trends that are rapidly having an increasing impact in Technology-Enhanced Learning. However, both approaches present significant technological challenges. Mobile technologies are very diverse and the market pressure pushes the continuous development of new technologies and features. On the other hand, game-based learning needs to deal with enormous development costs and the problem of allowing instructors and experts to actively participate in the game development process. Moreover, there are numerous situations where bringing both approaches together could be very useful, but this combination magnifies the technological barriers previously described. In this work we present , an authoring environment for educational adventure games that supports the production of both desktop and mobile games. This framework provides a graphical environment that allows instructors to create their own educational games with a low cost. Then, the games can be exported to multiple formats, including support for diverse types of mobile platforms. This is achieved through a modular semi-automated exportation process, which is based on mobile device profiles.
Applying Multimedia and Virtual Reality for Learning Environments
Authors: Sampaio Paulo Nazareno Maia , De Freitas Roberto Ivo C. , Cardoso Gonçalo Nuno P.
Published: October 2009

Most of the tools and languages for modeling Virtual Reality environments, such as VRML, X3D, Java3D, etc. do not provide means of describing the synchronized presentation of multimedia content inside these environments. Multimedia has demonstrated its capabilities of motivating users and capturing their attention, which are important characteristics when we want to provide a higher degree of immersion and learning capabilities inside Virtual Reality applications. This paper presents a robust and generic solution for the integrated presentation of different kinds of media objects inside virtual environments based on the Graphical Engine OGRE and how this solution can be applied broadly for providing customizable multimedia and virtual learning environments.
Towards a Standardized e-Assessment System: Motivations, Challenges and First Findings
Authors: AL-Smadi Mohammad , Gütl Christian , Helic Denis
Published: October 2009

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Authoring for Adaptive Web-Based Learning Systems: A Case Study
Authors: Obeidat Hala , Meccawy Maram , Blanchfield Peter
Published: October 2009

Adaptive Educational Hypermedia aims to provide tailored and personalised learning experiences to different students. However, one of its limitations which have resulted in its poor adoption by the e-learning community is the complexity of its authoring process. This paper tries to address this issue in order to push those adaptive systems forward. First, it presents an authoring aid for an existing adaptive system. Lessons learned from this case study are then used to provide a high-level design specification for an authoring tool with an accessible interface to ordinary teachers with limited IT-skills.
Virtual City as a Place for Educational and Social Activities
Authors: Fominykh Mikhail , Prasolova-Førland Ekaterina , Morozov Mikhail , Gerasimov Alexey
Published: October 2009

In recent years, virtual worlds have become increasingly popular in education and social life. Using a â??cityâ?? metaphor, we are developing a 3D virtual world enriched with social and educational tools. This virtual world allows performing a number of activities, such as exploring the city, learning and communicating with its citizens, building a social network. In this paper we report the results of case studies we have performed to explore usersâ?? activities and behavior in a virtual city context. Our goal was to investigate how such a city can facilitate learning and socializing, also in a cross-cultural context. Based on the empirical results, we derive a list of recommendations for a virtual city as a place for social and educational activities.
Magnetic resonance imaging in central nervous system tuberculosis
Authors: Trivedi Richa , Saksena Sona , Gupta Rakesh K
Published: October 2009

Tuberculosis (TB) in any form is a devastating disease, which in its most severe form involves the central nervous system (CNS), with a high mortality and morbidity. Early diagnosis of CNS TB is necessary for appropriate treatment to reduce this morbidity and mortality. Routine diagnostic techniques involve culture and immunological tests of the tissue and biofluids, which are time-consuming and may delay definitive management. Noninvasive imaging modalities such as computed tomography (CT) scan and magnetic resonance imaging (MRI) are routinely used in the diagnosis of neurotuberculosis, with MRI offering greater inherent sensitivity and specificity than CT scan. In addition to conventional MRI imaging, magnetization transfer imaging, diffusion imaging, and proton magnetic resonance spectroscopy techniques are also being evaluated for better tissue characterization in CNS TB. The current article reviews the role of various MRI techniques in the diagnosis and management of CNS TB.
How to improve your breast cancer program: Standardized reporting using the new American College of Radiology Breast Imaging-Reporting and Data System
Authors: Ojeda-Fournier Haydee , Nguyen Judy Q
Published: October 2009

In the USA, the use of the American College of Radiology Breast Imaging-Reporting and Data System (ACR BI-RADS) has served not only as a quality assurance tool and guide to standardizing breast imaging reports but has also improved communication between referring physicians, researchers, and patients. In fact, in the USA, the Mammography Quality Standards Act of 1997 requires that all mammograms be assigned a BI-RADS category based on the finding of most concern. In this manuscript, we aim to review the recommendations provided in the 4 th edition of the ACR BI-RADS for mammography, USG, and MRI. We also review the major controversies surrounding the use of ACR BI-RADS .
Pictorial essay: Mammography of the male breast
Authors: Popli Manju Bala , Popli V , Bahl P , Solanki Y
Published: October 2009

Mammography is an imaging modality that is widely perceived to be of use only in women for the detection and diagnosis of breast pathologies. Here, we present a pictorial essay on the mammographic spectrum of male breast pathologies.
Evaluation of breast calcifications
Authors: Nalawade Yojana V
Published: October 2009

Various patterns of calcifications occur in the breast; some benign, some malignant. A knowledge of these patterns on mammography helps in accurate interpretation and management.
Role of diffusion MRI in characterizing benign and malignant breast lesions
Authors: Palle Lalitha , Reddy Balaji
Published: October 2009

Aims: The aim of this study was to evaluate the role of MRI based diffusion-weighted imaging (DWI) and the apparent diffusion coefficient (ADC) for characterizing breast lesions in Indian patients. Materials and Methods : This prospective analysis was performed between October 2006 and June 2008. It includes 200 patients between the ages of 16 and 80 years with solid breast lesions greater than 1 cm in diameter. Of these 200 patients, 80 underwent breast MRI with contrast and DWI. One hundred and twenty patients had only DWI as they had come only for sonomammography. A total of 280 lesions were detected. ADC values were calculated for all the lesions and the highest and lowest values of ADC for benign and malignant lesions were identified. Finally, we compared our findings with those of previous studies. Results : Two hundred and eight lesions were categorized as benign and 72 lesions were categorized as malignant based on the ADC values. Based on previous data, lesions with ADC values from 1.3 to 1.5 mm 2 /s were considered benign where as lesions with ADC values ranging between 0.85 and1.1 mm 2 /s were considered malignant. Two lesions whose ADC values were in the benign range were proven to be malignant tumors after surgery. This method of using ADC values for the detection of malignant lesions showed a sensitivity of 97.22% and a specificity of 100%. The positive predictive value was 100%. Conclusion : DWI is a useful technique for characterizing breast tumors, especially for lesions that cannot be adequately characterized by ultrasonography and routine magnetic resonance imaging.
Case Report: CSF pseudocyst in the breast
Authors: Dayananda L , Karthik GA , Santhosh Kumar DG ,   Yameen
Published: October 2009

A cerebrospinal fluid (CSF) pseudocyst can rarely occur in the breast. It usually results from damage to a ventriculoperitoneal (VP) shunt during a mammogram or augmentation breast surgery. If fluid collection is seen in close proximity to the VP shunt, it should raise the suspicion of a CSF pseudocyst.
Case Report: CT diagnosis of thymic remnant cyst/thymopharyngeal duct cyst
Authors: Daga Bipin V , Chaudhary VA , Dhamangaokar VB
Published: October 2009

A 4-year-old boy presented with history of left anterolateral neck swelling since birth. He was clinically diagnosed to have a branchial cleft cyst. A CT scan revealed findings suggestive of a thymic remnant cyst. The lesion was excised and the diagnosis was confirmed by histopathology.
Reinke′s edema
Authors: Jain Sanjay , Varma Ravi , Hazarika Biswajyoti , Pradhan Sultan , Momin Asif
Published: October 2009

A unique imaging dilemma is presented where vocal fold thickening due to Reinke′s edema mimicked tumor invasion of the vocal cords in a known case of thyroid malignancy.
Case Report: Carotid-cavernous fistula due to aneurysmal rupture in a case of aortoaortitis with bilateral giant internal carotid artery aneurysms
Authors: Sharma Sandeep , Kumar Subhash , Nanda Arvind , Moses Edmond
Published: October 2009

Takayasu aortoarteritis (TA) rarely affects the nervous system, but when it does, it usually manifests as cerebral ischemia or stroke. These strokes have mainly been attributed to stenotic extracranial vessels. Stenoses of intracranial vessels, although rare in TA, can occur due to either embolization into the vessel or because of the vasculitic process itself. Intracranial aneurysms are very rare in patients with TA. Bilateral cavernous internal carotid artery (ICA) aneurysms are rarer. They have been reported following radiation therapy and in association with fibromuscular dysplasia and juvenile Paget disease. Bilateral mycotic intracavernous aneurysms also occur. Bilateral giant cavernous ICA aneurysms with carotid-cavernous fistula (CCF) consequent to rupture into the cavernous sinus in a case of TA are extremely unusual. We report a case that fulfilled both American College of Rheumatology and European League against Rheumatology criteria for TA. The patient had bilateral cavernous sinus giant aneurysms and CCF because the right-sided aneurysm had ruptured and was leaking into the cavernous sinus.
Case Report: Anteromedial temporosphenoidal encephalocele with a clinically silent lateral bony defect in the greater wing of the sphenoid
Authors: Pandey Anoop Kumar
Published: October 2009

Anteromedial temporosphenoidal encephalocele is the least common type of temporal encephalocele. It commonly presents with spontaneous cerebrospinal fluid rhinorrhea in adults. This article presents the CT cisternography and MRI findings of one such case, which also had an associated clinically silent defect in the greater wing of the sphenoid on the same side.
Case Report: Cerebrotendinous xanthomatosis
Authors: Karandikar Amit A , Pushparajan S , Unni Madhavan N , Srinivas R
Published: October 2009

Cerebrotendinous xanthomatosis is a rare genetic disorder. We present and discuss the clinical, radiological, and histopathologic findings in a 36-year-old woman who had juvenile cataract, childhood diarrhea, mental retardation, cerebellar ataxia, and bilateral Achilles tendon xanthomas. She was thoroughly investigated radiologically and biopsy confirmed the diagnosis of xanthomas.
ERP Implementations and their Impact Upon Management Accountants
Authors: Sangster Alan , A. Leech Stewart , Grabski Severin
Published: October 2009

This paper considers the impact of ERP implementations upon the role of management accountants, upon management accounting in general, and upon business processes. It does so in the context of the perceived success of the ERP implementation. A postal questionnaire was circulated to almost 700 management accountants working in large UK-based organisations. It finds that under successful ERP implementations, management accountants have time for other, less mundane activities and their role becomes more enriching. In contrast, when the implementation is unsuccessful, the role of the management accountant increases: the ERP system deficiencies require increased activity on their part without any noticeable reduction in the tasks they traditionally perform.
Cultural Influences on Adoption of Project Management: a Qualitative Study in Consulting and IT Development Companies
Authors: Ferreira da Rocha Neto Carlos , Leal Jamil George , Reis Lobo de Vasconcelos Maria Celeste
Published: October 2009

If the Project Management is analyzed from the point of view of new combinations that include already known techniques with a generic approach to manage projects, its biggest contribution to the organizations is found. However, the question that is raised is: how to make these management approaches generally applicable in all types, forms or origins of organizations? This paper presents, through a multiple case study, an analysis of the cultural influence, in the adoption of the Management Project in consulting and IT development companies. Based on the semi-structured interviews, its possible to note that the organizational culture, whether from the point of view of senior management or in the domain of several groups that are formed within organizations, sets limits and adjustments which are necessary for the adoption of Project Management that effectively contribute to organizational competitiveness.