bluuebunny/crossref_metadata_2025 huggingface dataset:
Globba chekiangensis sp. nov. (Zingiberaceae) from the Zhejiang and Jiangxi provinces, China
Authors: Li G. Y. , Chen Z. H. , Xia G. H.
Published: March 2009

Globba chekiangensis from the Zhejiang and Jiangxi provinces in east China is described, illustrated and compared with its nearest allies, G. emeiensis and G. racemosa.
Muscari vuralii sp. nov. (Liliaceae/Hyacinthaceae) from south Anatolia, Turkey
Authors: Doğu Süleyman , Bağcı Yavuz
Published: March 2009

Muscari vuralii Y. Bağcı & Doğu sp. nov. (Liliaceae/Hyacinthaceae) from the Karaman (C4 Karaman–Turkey) is described and illustrated. It is closely related to M. coeleste Fomin and M. macbeathianum Kit Tan. Diagnostic morphological characters are discussed and a key to related Muscari species in Turkey is given. The geographical distribution of the new species is mapped. Notes are also presented on its ecology, biogeography and conservation status.
Lectotypification of two Musa sections (Musaceae)
Authors: Häkkinen Markku
Published: March 2009

The present work is part of a continuing study to revise the old names in Musa and aims to clarify the taxonomy in the sections Rhodoclamys and Callimusa. Lectotypes are designated here for Musa sect. Callimusa and M. sect. Rhodochlamys. These sections were first erected without the indication of a type species.
System Identification and Robust Controller Design Using Genetic Algorithms for Flexible Space Structures
Authors: Schoen Marco P. , Hoover Randy C. , Chinvorarat Sinchai , Schoen Gerhard M.
Published: March 2009

This paper is concerned with the problem of identifying and controlling flexible structures. The structures used exhibit some of the characteristics found in large flexible space structures (LFSSs). Identifying LFSS are problematic in the sense that the modes are of low frequency, lightly damped, and often closely spaced. The proposed identification algorithm utilizes modal contribution coefficients to monitor the data collection. The algorithm is composed of a two-step process, where the input signal for the second step is recomputed based on knowledge gained about the system to be identified. In addition, two different intelligent robust controllers are proposed. In the first controller, optimization is concerned with performance criteria such as rise time, overshoot, control energy, and a robustness measure among others. Optimization is achieved by using an elitism based genetic algorithm (GA). The second controller uses a nested GA resulting in an intelligent linear quadratic regulator/linear quadratic Gaussian (LQR/LQG) controller design. The GAs in this controller are used to find the minimum distance to uncontrollability of a given system and to maximize that minimum distance by finding the optimal coefficients in the weighting matrices of the LQR/LQG controller. The proposed algorithms and controllers are tested numerically and experimentally on a model structure. The results show the effectiveness of the proposed two-step identification algorithm as well as the utilization of GAs applied to the problem of designing optimal robust controllers.
Development of a Fast Operation Algorithm of a Small-Scale Fuel Cell System With Solar Reforming
Authors: Obara Shin’ya , Tanno Itaru
Published: March 2009

The small-scale bioethanol steam reforming system (FBSR), using sunlight applied to a heat source, is a very clean method, which can supply fuel to a fuel cell. However, it is difficult to analyze the operation planning of this system with high precision. If such an analytical algorithm is developed, the optimum operation of this system will be realized by the command of the control device. However, the difficulty of weather forecasts, such as solar radiation and outside-air-temperature, to date has made it difficult to achieve rapid and highly precise results and to analyze the system operation. In this paper, an algorithm, which analyzes the operation planning of the FBSR on arbitrary days, is developed using the neural network. The weather pattern for the past 1 year is input into this algorithm, and the operation planning of the FBSR, based on the same weather pattern, is given as a training signal. In this paper, the operation results of the system obtained via genetic algorithm (GA) were used as the training signal for the neural network. Operation planning (the amount of hydrogen production and the amount of exhaust heat storage) of the system on arbitrary days could be obtained rapidly by ensuring that input data (the weather and energy-demand patterns) are channeled into the learned neural network following this study. Moreover, in order to investigate the accuracy of the operational analysis via the proposed algorithm, it is compared with the analysis result of operation planning using the GA.
Discrete Fourier Transform Based Iterative Learning Control Design for Linear Plants With Experimental Verification
Authors: Freeman C. T. , Lewin P. L. , Rogers E. , Owens D. H. , Hatonen J. J.
Published: March 2009

This paper considers the design of linear iterative learning control algorithms using the discrete Fourier transform of the measured impulse response of the system or plant under consideration. It is shown that this approach leads to a transparent design method whose performance is then experimentally benchmarked on an electromechanical system. The extension of this approach to the case when there is uncertainty associated with the systems under consideration is also addressed in both algorithm development and experimental benchmarking terms. The robustness results here have the applications oriented benefit of allowing the designer to manipulate the convergence and robustness properties of the algorithm in a straightforward manner.
Motion Planning and Tracking for Tip Displacement and Deflection
Angle for Flexible Beams
Authors: Siranosian Antranik A. , Krstic Miroslav , Smyshlyaev Andrey , Bement Matt
Published: March 2009

Explicit motion-planning reference solutions are presented for flexible beams with Kelvin–Voigt (KV) damping. The goal is to generate periodic reference signals for the displacement and deflection angle at the free-end of the beam using only actuation at the base. The explicit deflection angle reference solution is found as a result of writing the shear beam model in a strict-feedback form. Special “partial differential equation (PDE) backstepping” transformations relate the strict-feedback model to a “target system,” governed by an exponentially stable wave equation with KV damping, whose displacement reference solution is relatively easy to find. The explicit beam displacement reference solution is found using the target system solution and an inverse backstepping transformation. The explicit reference solutions for the wave equation and shear beam with KV damping are novel results. State-feedback tracking boundary controllers are found by extending previous PDE backstepping stabilization results. Application of the shear beam results to the more complicated Timoshenko beam is discussed.
Characterization and Attenuation of Sandwiched Deadband Problem Using Describing Function Analysis and Application to Electrohydraulic Systems Controlled by Closed-Center Valves
Authors: Liu Song , Yao Bin
Published: March 2009

Unlike input deadband, the sandwiched deadband between actuator and plant dynamics is very difficult to be explicitly compensated for due to the proceeding actuator dynamics whose effect may not be negligible. The paper presents a practical way to overcome the design conservativeness of existing methods in dealing with sandwiched deadband. Specifically, a describing function based nonlinear analysis method is proposed to characterize the effect of the sandwiched deadband on the stability and performance of the overall closed-loop system. The analysis results can be used to determine the highest closed-loop bandwidth that can be achieved without inducing residual limit cycles and instability. Optimal controller parameters can then be found to maximize the achievable closed-loop control performance. The technique is applied to an electrohydraulic system controlled by closed-center valves and a nonlinear feedback controller. Simulation results showed severe oscillations as the feedback control gains are increased to the predicted threshold values. Comparative experimental results also showed the effectiveness of the proposed method in reducing the conservativeness of traditional design and the improved closed-loop control performance in implementation.
An Approach for Actuation Specification and Synthesis of Dynamic Systems
Authors: Connolly Thomas J. , Longoria Raul G.
Published: March 2009

Refinement or improvement of a dynamic system to meet a frequency response specification can benefit from the option to use passive or active compensation, or a combination of both. The process becomes more effective when supplemented with methods derived from classical network theory to synthesize candidate designs for actuators and their control systems. The synthesis procedure presented here provides an explicit way to formulate system topologies that employ passive and active elements to achieve a desired targeted performance specification, i.e., frequency response. Active elements are used to represent elements that are not physically realizable, such as negative impedances and elements that have ill-defined connectivity. A working premise is that these elements indicate the need for actuation technology. Coupled with a topological description of the system, the synthesis procedure provides a systematic approach that offers design solutions not previously conceived of through insight or experience. These “first draft” designs can be improved upon by later utilizing complementary approaches, such as optimization methods, as dictated by detailed system requirements and operating regimes. The flexibility of this synthesis approach allows the consideration of design restrictions unrelated to frequency response, but critical nonetheless in assessing the viability of candidate designs. Further, the procedure does not require assumption of a particular control/compensation architecture at the outset; this renders novel architectures that depart from traditional architectures such as proportional integral, propotional-integral-derivative, etc. The procedure is couched within a simulation basis, so that extension to state-space simulation and thus growth of the system and inclusion of more complex and nonlinear representations become possible. The concept of a virtual state space is introduced, which is integral to the development of controller architectures and associated parameters. It is found that customized passive/active compensation systems can be derived using a bond graph approach, making this approach more easily applicable to multi-energetic systems. Examples are used to demonstrate the approach, including a case study of an electromechanical vehicle suspension, from which an experimental model is derived to illustrate the synthesis procedure. Comparison of results between these examples illustrate the practical utility of the synthesis procedure. In particular, simulations reveal that increasing the number of realized passive elements for a particular system does not necessarily minimize actuator energy consumption. Detailed analysis of synthesis results show that certain design candidates feature active devices that work against either passive elements or other active devices within the system.
High-Level Genetic Diversity but No Population Structure Inferred from Nuclear and Mitochondrial Markers of the Peritrichous CiliateCarchesium polypinumin the Grand River Basin (North America)
Authors: Gentekaki E. , Lynn D. H.
Published: March 2009

Studies that assess intraspecific genetic variation in ciliates are few and quite recent. Consequently, knowledge of the subject and understanding of the processes that underlie it are limited. We sought to assess the degree of intraspecific genetic variation inCarchesium polypinum(Ciliophora: Peritrichia), a cosmopolitan, freshwater ciliate. We isolated colonies ofC. polypinumfrom locations in the Grand River basin in Southwestern Ontario, Canada. We then used the nuclear markers—ITS1, ITS2, and the hypervariable regions of the large subunit rRNA—and an 819-bp fragment of the mitochondrial cytochromecoxidase I gene (cox-1) to investigate the intraspecific genetic variation ofC. polypinumand the degree of resolution of the above-mentioned markers at the population level. We also sought to determine whether the organism demonstrated any population structure that mapped onto the geography of the region. Our study shows that there is a high degree of genetic diversity at the isolate level, revealed by the mitochondrial markers but not the nuclear markers. Furthermore, our results indicate thatC. polypinumis likely not a single morphospecies as previously thought.
Differential Responses of Nitrate Reducer Community Size, Structure, and Activity to Tillage Systems
Authors: Chèneby D. , Brauman A. , Rabary B. , Philippot L.
Published: March 2009

The main objective of this study was to determine how the size, structure, and activity of the nitrate reducer community were affected by adoption of a conservative tillage system as an alternative to conventional tillage. The experimental field, established in Madagascar in 1991, consists of plots subjected to conventional tillage or direct-seeding mulch-based cropping systems (DM), both amended with three different fertilization regimes. Comparisons of size, structure, and activity of the nitrate reducer community in samples collected from the top layer in 2005 and 2006 revealed that all characteristics of this functional community were affected by the tillage system, with increased nitrate reduction activity and numbers of nitrate reducers under DM. Nitrate reduction activity was also stimulated by combined organic and mineral fertilization but not by organic fertilization alone. In contrast, both negative and positive effects of combined organic and mineral fertilization on the size of the nitrate reducer community were observed. The size of the nitrate reducer community was a significant predictor of the nitrate reduction rates except in one treatment, which highlighted the inherent complexities in understanding the relationships the between size, diversity, and structure of functional microbial communities along environmental gradients.
RNA Interference-Mediated Silencing of Ornithine Decarboxylase and Spermidine Synthase Genes in
Trypanosoma brucei
Provides Insight into Regulation of Polyamine Biosynthesis
Authors: Xiao Yanjing , McCloskey Diane E. , Phillips Margaret A.
Published: March 2009

Polyamine biosynthesis is a drug target for the treatment of African sleeping sickness; however, mechanisms regulating the pathway in
Trypanosoma brucei
are not well understood. Recently, we showed that RNA interference (RNAi)-mediated gene silencing or the inhibition of
S
-adenosylmethionine decarboxylase (AdoMetDC) led to the upregulation of the AdoMetDC activator, prozyme, and ornithine decarboxylase (ODC) proteins. To determine if this regulatory response is specific to AdoMetDC, we studied the effects of the RNAi-induced silencing of the spermidine synthase (SpdSyn) and ODC genes in bloodstream form
T. brucei
. The knockdown of either gene product led to the depletion of the polyamine and trypanothione pools and to cell death. Decarboxylated AdoMet levels were elevated, while AdoMet was not affected. There was no significant effect on the protein levels of other polyamine pathway enzymes. The treatment of parasites with the ODC inhibitor α-difluoromethylornithine gave similar results to those observed for ODC knockdown. Thus, the cellular response to the loss of AdoMetDC activity is distinctive, suggesting that AdoMetDC activity controls the expression levels of the other spermidine biosynthetic enzymes. RNAi-mediated cell death occurred more rapidly for ODC than for SpdSyn. Further, the ODC RNAi cells were rescued by putrescine, but not spermidine, suggesting that the depletion of both putrescine and spermidine is more detrimental than the depletion of spermidine alone. This finding may contribute to the effectiveness of ODC as a target for the treatment of African sleeping sickness, thus providing important insight into the mechanism of action of a key antitrypanosomal agent.
Structure and Complexity of a Bacterial Transcriptome
Authors: Passalacqua Karla D. , Varadarajan Anjana , Ondov Brian D. , Okou David T. , Zwick Michael E. , Bergman Nicholas H.
Published: March 2009

Although gene expression has been studied in bacteria for decades, many aspects of the bacterial transcriptome remain poorly understood. Transcript structure, operon linkages, and information on absolute abundance all provide valuable insights into gene function and regulation, but none has ever been determined on a genome-wide scale for any bacterium. Indeed, these aspects of the prokaryotic transcriptome have been explored on a large scale in only a few instances, and consequently little is known about the absolute composition of the mRNA population within a bacterial cell. Here we report the use of a high-throughput sequencing-based approach in assembling the first comprehensive, single-nucleotide resolution view of a bacterial transcriptome. We sampled the
Bacillus anthracis
transcriptome under a variety of growth conditions and showed that the data provide an accurate and high-resolution map of transcript start sites and operon structure throughout the genome. Further, the sequence data identified previously nonannotated regions with significant transcriptional activity and enhanced the accuracy of existing genome annotations. Finally, our data provide estimates of absolute transcript abundance and suggest that there is significant transcriptional heterogeneity within a clonal, synchronized bacterial population. Overall, our results offer an unprecedented view of gene expression and regulation in a bacterial cell.
Structure of 2:1 cobalt(III) complexes derived from arylazocitrazinic acid
Authors: Kořínková Jaroslava , Lyčka Antonín , Cee Aleš , Nádvorník Milan , Jirásko Robert , Hrdina Radim
Published: March 2009

1H, 13C NMR and MS spectra of the 2:1 cobalt(III) complexes, the azo coupling products of 2-aminophenol or 2-aminobenzoic acid with the citrazinic acid, were measured and analysed. It was found that the cobalt atom is six-coordinated being bound to two oxygens (one from primary and one from secondary component) and the nitrogen of 2-aminophenol or 2-aminobenzoic acid. Molar magnetic susceptibility data proved the presence of Co(III). Diazotisation of 2-aminophenol or 2-aminobenzoic acid and subsequent coupling reaction with citrazinic acid and complexation of the formed azo product proceeded on standard way.
Epoxyeicosanoids as mediators of neurogenic vasodilation in cerebral vessels
Authors: Iliff Jeffrey J. , Wang Ruikang , Zeldin Darryl C. , Alkayed Nabil J.
Published: March 2009

Epoxyeicosatrienoic acids (EETs) are potent vasodilators produced from arachidonic acid by cytochrome P-450 (CYP) epoxygenases and metabolized to vicinal diols by soluble epoxide hydrolase (sEH). In the brain, EETs are produced by astrocytes and the vascular endothelium and are involved in the control of cerebral blood flow (CBF). Recent evidence, however, suggests that epoxygenases and sEH are present in perivascular vasodilator nerve fibers innervating the cerebral surface vasculature. In the present study, we tested the hypothesis that EETs are nerve-derived relaxing factors in the cerebral circulation. We first traced these fibers by retrograde labeling in the rat to trigeminal ganglia (TG) and sphenopalatine ganglia (SPG). We then examined the expression of CYP epoxygenases and sEH in these ganglia. RT-PCR and Western blot analysis identified CYP2J3 and CYP2J4 epoxygenase isoforms and sEH in both TG and SPG, and immunofluorescence double labeling identified CYP2J and sEH immunoreactivity in neuronal cell bodies of both ganglia. To evaluate the functional role of EETs in neurogenic vasodilation, we elicited cortical hyperemia by electrically stimulating efferent cerebral perivascular nerve fibers and by chemically stimulating oral trigeminal fibers with capsaicin. Cortical blood flow responses were monitored by laser-Doppler flowmetry. Local administration to the cortical surface of the putative EET antagonist 14,15-epoxyeicosa-5( Z)-enoic acid (30 μmol/l) attenuated CBF responses to electrical and chemical stimulation. These results suggest that EETs are produced by perivascular nerves and play a role in neurogenic vasodilation of the cerebral vasculature. The findings have important implications to such clinical conditions as migraine, vasospasm after subarachnoid hemorrhage, and stroke.
Isolation of murine lung endothelial cells
Authors: Fehrenbach Melane L. , Cao Gaoyuan , Williams James T. , Finklestein Jeffrey M. , DeLisser Horace M.
Published: March 2009

Several protocols for the isolation of endothelial cells (ECs) from murine lung have been described in the literature. We, however, encountered a number of problems while using these procedures that prevented us from consistently or reliably obtaining pure populations of ECs from the lungs of mice. By incorporating specific elements from previously published protocols, as well as adding some novel features, we developed a new strategy for isolating ECs from murine lung. In this approach, a suspension of lung cells is initially prepared from the lungs of 7- to 14-day-old mouse pups using procedures that prevent intravascular clotting and leukocyte activation, minimize mechanical trauma to the lung tissue, and limit exposure to the digesting enzymes. The resulting cell suspension is cultured for 2–3 days, trypsinized to produce a suspension of single cells, and then subjected to fluorescence-activated cell sorting using an anti-ICAM-2 antibody. The sorted cells are then plated and split 1:2 at each passage to maintain a high density of the cells. Using this approach, we have been able to isolate pure populations of ECs that were sustainable for extended periods in culture without the emergence of fibroblast overgrowth or the development of senescence. We believe the success of this approach will provide opportunities to take advantage of the large and growing number of knockout and transgenic mouse lines to investigate the endothelial-specific roles of targeted molecules in the pulmonary vasculature.
Lung environment determines unique phenotype of alveolar macrophages
Authors: Guth Amanda M. , Janssen William J. , Bosio Catharine M. , Crouch Erika C. , Henson Peter M. , Dow Steven W.
Published: March 2009

Alveolar macrophages (AM) are the most abundant antigen-presenting cells in the lungs, and they play a critical role in regulating pulmonary immune responses to inhaled pathogens and to allergens. However, compared with macrophages in other body sites, AM have an unusual phenotype that, in many respects, resembles the phenotype of dendritic cells (DC). Therefore, to more fully define the unique nature of AM, we compared the phenotype and function of AM with the phenotype and function of resident peritoneal lavage-derived macrophages (PLM). We found striking phenotypic differences between AM and PLM, particularly with regard to CD11c expression, and we also observed that AM had a significantly better antigen-presenting capability than PLM. Therefore, we investigated the role of the local airway environment in generation of the unusual phenotype of AM. We carried out cell transfer experiments to compare macrophage differentiation in the airways with that in the peritoneal cavity. We observed significant upregulation of CD11c expression on bone marrow macrophages and peritoneal macrophages when they were adoptively transferred into the airways. In contrast, CD11c expression was not upregulated after cell transfer into the peritoneal cavity, whereas CD11b expression was significantly increased. In vitro, culture of bone marrow-adherent cells with surfactant protein D (SP-D) or granulocyte/macrophage colony-stimulating factor (GM-CSF) induced significant upregulation of CD11c expression, and in vivo GM-CSF concentrations were significantly higher in bronchoalveolar than in peritoneal lavage fluid. Finally, GM-CSF−/−mice failed to develop CD11c+AM, but CD11c+AM were present in SP-D−/−mice. However, macrophages from GM-CSF−/−bone marrow could upregulate CD11c expression when transferred to the airways of wild-type mice. These results suggest that the airway environment promotes development of macrophages with unique DC-like characteristics and that this unusual phenotype is determined, to a large degree, by locally high concentrations of GM-CSF and, possibly, SP-D.
Neural Correlates of Human Body Perception
Authors: Aleong Rosanne , Paus Tomáš
Published: March 2009

The objective of this study was to investigate potential sex differences in the neural response to human bodies using fMRI carried out in healthy young adults. We presented human bodies in a block-design experiment to identify body-responsive regions of the brain, namely, extrastriate body area (EBA) and fusiform body area (FBA). In a separate event-related “adaptation” experiment, carried out in the same group of subjects, we presented sets of four human bodies of varying body size and shape. Varying levels of body morphing were introduced to assess the degree of morphing required for adaptation release. Analysis of BOLD signal in the block-design experiment revealed significant Sex × Hemisphere interactions in the EBA and the FBA responses to human bodies. Only women showed greater BOLD response to bodies in the right hemisphere compared with the left hemisphere for both EBA and FBA. The BOLD response in right EBA was higher in women compared with men. In the adaptation experiment, greater right versus left hemisphere response for EBA and FBA was also identified among women but not men. These findings are particularly novel in that they address potential sex differences in the lateralization of EBA and FBA responses to human body images. Although previous studies have found some degree of right hemisphere dominance in body perception, our results suggest that such a functional lateralization may differ between men and women.
On the Temporal Relation of Top–Down and Bottom–Up Mechanisms during Guidance of Attention
Authors: Wykowska Agnieszka , Schubö Anna
Published: March 2009

Two mechanisms are said to be responsible for guiding focal attention in visual selection: bottom–up, saliency-driven capture and top–down control. These mechanisms were examined with a paradigm that combined a visual search task with postdisplay probe detection. Two SOAs between the search display and probe onsets were introduced to investigate how attention was allocated to particular items at different points in time. The dynamic interplay between bottom–up and top–down mechanisms was investigated with ERP methodology. ERPs locked to the search displays showed that top–down control needed time to develop. N2pc indicated allocation of attention to the target item and not to the irrelevant singleton. ERPs locked to probes revealed modulations in the P1 component reflecting top–down control of focal attention at the long SOA. Early bottom–up effects were observed in the error rates at the short SOA. Taken together, the present results show that the top–down mechanism takes time to guide focal attention to the relevant target item and that it is potent enough to limit bottom–up attentional capture.
Brain Structures Involved in Visual Search in the Presence and Absence of Color Singletons
Authors: Talsma Durk , Coe Brian , Munoz Douglas P. , Theeuwes Jan
Published: March 2009

It is still debated to what degree top–down and bottom–up driven attentional control processes are subserved by shared or by separate mechanisms. Interactions between these attentional control forms were investigated using a rapid event-related fMRI design, using an attentional search task. Following a prestimulus mask, target stimuli (consisting of a letter C or a mirror image of the C, enclosed in a diamond outline) were presented either at one unique location among three nontarget items (consisting of a random letter, enclosed in a circle outline; 50% probability), or at all four possible target locations (also 50% probability). On half the trials, irrelevant color singletons were presented, consisting of a color change of one of the four prestimulus masks, just prior to target appearance. Participants were required to search for a target letter inside the diamond and report its orientation. Results indicate that, in addition to a common network of parietal areas, medial frontal cortex is uniquely involved in top–down orienting, whereas bottom–up control is mainly subserved by a network of occipital and parietal areas. Additionally, we found that participants who were better able to suppress orienting to the color singleton showed middle frontal gyrus activation, and that the degree of top–down control correlated with insular activity. We conclude that, in addition to a common set of parietal areas, separate brain areas are involved in top–down and bottom–up driven attentional control, and that frontal areas play a role in the suppression of attentional capture by an irrelevant color singleton.
Bursaphelenchus tokyoensis n. sp. (Nematoda: Parasitaphelenchinae) isolated from dead wood of the Japanese red pine, Pinus densiflora Sieb. & Zucc., in Japan
Authors: Kanzaki Natsumi , Aikawa Takuya , Giblin-Davis Robin
Published: March 2009

Bursaphelenchus tokyoensis n. sp. is described and figured from a dead Japanese red pine, Pinus densiflora. Despite several attempts, the new species was not successfully cultured and so individuals isolated from the original dead log were used as type specimens. The new species has a body length of ca 710 μm (male) and 770 μm (female), medium values of ratio a (ca 32-38 for males and ca 29-41 for females), b ratio of ca 10-12 (male) and 11-14 (female), c ratio of ca 24-29 (male) and 30-41 (female), c′ ratio of ca 2.3 (male) and ca 2.0 (female), ca 11-14 μm long stylet, four lines in the lateral field, relatively small (ca 14-16 μm), smoothly arcuate spicule lacking clear condylus, rostrum and cucullus, seven male caudal papillae and short and broad female tail with variable-shaped terminus. The new species is typologically close to B. idius but can be distinguished by male caudal papillae arrangement, female tail length and number of lateral lines. Inferred trees based upon molecular phylogenetic analysis of near full length (ca 1.6 kb) small subunit and ca 0.7 kb of the D2/D3 expansion segment of the large subunit of ribosomal DNA placed B. tokyoensis n. sp. closest to the xylophilus- and africanus-groups. However, the new species is distinguished from members of these groups by its characteristic spicule morphology and relative molecular phylogenetic placement.
Distribution and population structure of two bacterial-feeding nematode genera in ice-free areas in East Antarctica
Authors: Boström Sven , Sohlenius Björn
Published: March 2009

Very dense populations of nematodes of the genera Plectus and Panagrolaimus were found in moss cushions and in ornithogenic soils in a number of localities on mountain outcrops (nunataks) penetrating the ice sheet and in a coastal oasis in East Antarctica. These high abundances permitted analysis of the structure of populations from various sites. Patterns of distribution and size-class composition in nematode populations from the Basen nunatak, and from scattered samples taken in a larger area including several nunataks and one coastal oasis in Dronning Maud Land, were investigated. It is suggested that the composition of developmental stages and structure of the nematode populations are influenced by environmental conditions such as food supply, temperature and maybe predation or competition from coexisting populations of tardigrades, protozoans and rotifers. The results indicated that the population dynamics were not synchronised among the sites. In several populations the animals appeared well fed with a high frequency of gravid females. In the more extreme localities, in particular, the proportion of adults was very high, and in these sites the recruitment to the populations appeared to be rather low as indicated by the low proportion of juveniles. The structure of the nematode populations seemed little influenced by various combinations of co-occurring tardigrades or rotifers. There were some differences in population structure between nematode populations from different nunataks which could possibly be caused by genetic variability due to long periods of isolation.
Differential susceptibility of entomopathogenic nematodes to nematophagous fungi from Florida citrus orchards
Authors: Bright Diane , El-Borai Fahiem , Stuart Robin , Graham James , Cubero Jaime , Duncan Larry
Published: March 2009

Laboratory experiments were conducted to study the effects of various trapping and endoparasitic nematophagous fungi (NF) isolated from Florida citrus orchards on five entomopathogenic nematode (EPN) species that show various distributions across Florida's citrus industry. Four trapping NF (Arthrobotrys oligospora, A. dactyloides, A. musiformis and Gamsylella gephyropaga) and two endoparasitic NF (Catenaria sp. and Myzocytium sp.) were tested against Steinernema diaprepesi (Sd), S. glaseri (Sg), S. riobrave (Sr), Heterorhabditis zealandica (Hz) and H. indica (Hi). Fungi were added to soil microcosms either as a pure culture on agar plugs (trapping NF) or as fungal-colonised nematodes (endoparasitic NF) on agar plugs, concurrently with 2000 EPN of a given species. After 7 or 14 days exposure, nematodes were recovered from the soil using Baermann funnels. The recovery of all EPN species was reduced between 56-92% by G. gephyropaga. Neither Sd or Sg were affected by any species of Arthrobotrys, whereas A. musiformis reduced recovery of all other EPN and A. oligospora reduced numbers of all other species except Hi. Both endoparasitic NF reduced the recovery of all EPN except Hi by at least 82%. The data are consistent with the hypothesis that NF may play a role in regulating regional patterns of abundance and diversity of EPN species in Florida, which in turn regulate the abundance of a major citrus pest, the Diaprepes root weevil, Diaprepes abbreviatus.
Bernardius lineatus gen. n., sp. n. (Enoplida: Enchelidiidae), a remarkable nematode with ornamented cuticle from a Brazilian tropical sandy beach
Authors: da Fonsêca-Genevois Veronica , Venekey Virág , Decraemer Wilfrida , Smol Nic
Published: March 2009

Bernardius lineatus gen. n., sp. n. is described from a sandy beach at Tamandaré Bay, Brazil. It possesses the main characteristics of the family Enchelidiidae (Nematoda: Enoplida), but is unique by the presence of a body cuticle ornamented with longitudinal ridges formed by small rods, an entirely different character to all other members of the order Enoplida. The new genus is also characterised by a long, subdivided, buccal cavity with two subventral teeth and numerous denticles and the arrangement of the anterior sensilla in two crowns, the anterior crown being papilliform and the posterior crown consisting of six external labial and four cephalic sensilla, setiform. The relationships of the genera within the Enchelidiidae are discussed and an emended family diagnosis provided.
Application of a Subfilter-Scale Flux Model over the Ocean Using OHATS Field Data
Authors: Kelly Mark , Wyngaard John C. , Sullivan Peter P.
Published: March 2009

Simple rate equation models for subfilter-scale scalar and momentum fluxes have previously been developed for application in the so-called “terra incognita” of atmospheric simulations, where the model resolution is comparable to the scale of turbulence. The models performed well over land, but only the scalar flux model appeared to perform adequately over the ocean. Analysis of data from the Ocean Horizontal Array Turbulence Study (OHATS) reveals a need to account for the moving ocean–air interface in the subfilter stress model. The authors develop simple parameterizations for the effect of surface-induced pressure fluctuations on the subfilter stress, leading to good predictions of subfilter momentum flux both over land and in OHATS.
Circulation and Transport in the Western Boundary Currents at Cape Farewell, Greenland
Authors: Holliday N. P. , Bacon S. , Allen J. , McDonagh E. L.
Published: March 2009

The circulation and volume transports in the western boundary currents around Cape Farewell, Greenland, are derived from full-depth hydrographic and velocity measurements from August–September 2005. The western boundary currents from surface to seafloor transport 40.5 ± 8.1 Sv (Sv ≡ 106 m3 s−1) southward in the Irminger Sea, and 53.8 ± 10.8 Sv northward in the Labrador Sea. The Deep Western Boundary Current (DWBC, defined as water with potential density greater than 27.80 kg m−3) transports 12.3 ± 2.5 Sv southward in the Irminger Sea. The deep water transport is reduced south of Cape Farewell, where it changes flow direction from southward to northward (the south corner). At a section over the Eirik Ridge, a bathymetric feature extending southwest of Cape Farewell, the DWBC transports 8.7 ± 1.7 Sv westward. The reduction in transport at the south corner is associated with decreased velocities within the deepest layers and the volumetric loss of the most saline deep water types. The observations suggest that the paths of the shallow and deep western boundary currents diverge at the south corner. Downstream in the eastern Labrador Sea the deep water transport is increased to 19.7 ± 3.9 Sv northward, with the addition of recirculating denser deep waters. The representativeness of the results from the semisynoptic survey is discussed with reference to companion current meter measurements of the DWBC.
Mean Dynamic Topography of the Ocean Derived from Satellite and Drifting Buoy Data Using Three Different Techniques*
Authors: Maximenko Nikolai , Niiler Peter , Centurioni Luca , Rio Marie-Helene , Melnichenko Oleg , Chambers Don , Zlotnicki Victor , Galperin Boris
Published: March 2009

Presented here are three mean dynamic topography maps derived with different methodologies. The first method combines sea level observed by the high-accuracy satellite radar altimetry with the geoid model of the Gravity Recovery and Climate Experiment (GRACE), which has recently measured the earth’s gravity with unprecedented spatial resolution and accuracy. The second one synthesizes near-surface velocities from a network of ocean drifters, hydrographic profiles, and ocean winds sorted according to the horizontal scales. In the third method, these global datasets are used in the context of the ocean surface momentum balance. The second and third methods are used to improve accuracy of the dynamic topography on fine space scales poorly resolved in the first method. When they are used to compute a multiyear time-mean global ocean surface circulation on a 0.5° horizontal resolution, both contain very similar, new small-scale midocean current patterns. In particular, extensions of western boundary currents appear narrow and strong despite temporal variability and exhibit persistent meanders and multiple branching. Also, the locations of the velocity concentrations in the Antarctic Circumpolar Current become well defined. Ageostrophic velocities reveal convergent zones in each subtropical basin. These maps present a new context in which to view the continued ocean monitoring with in situ instruments and satellites.
Experiments of Hurricane Initialization with Airborne Doppler Radar Data for the Advanced Research Hurricane WRF (AHW) Model
Authors: Xiao Qingnong , Zhang Xiaoyan , Davis Christopher , Tuttle John , Holland Greg , Fitzpatrick Patrick J.
Published: March 2009

Initialization of the hurricane vortex in weather prediction models is vital to intensity forecasts out to at least 48 h. Airborne Doppler radar (ADR) data have sufficiently high horizontal and vertical resolution to resolve the hurricane vortex and its imbedded structures but have not been extensively used in hurricane initialization. Using the Weather Research and Forecasting (WRF) three-dimensional variational data assimilation (3DVAR) system, the ADR data are assimilated to recover the hurricane vortex dynamic and thermodynamic structures at the WRF model initial time. The impact of the ADR data on three hurricanes, Jeanne (2004), Katrina (2005) and Rita (2005), are examined during their rapid intensification and subsequent weakening periods before landfall.

With the ADR wind data assimilated, the three-dimensional winds in the hurricane vortex become stronger and the maximum 10-m winds agree better with independent estimates from best-track data than without ADR data assimilation. Through the multivariate incremental structure in WRF 3DVAR analysis, the central sea level pressures (CSLPs) for the three hurricanes are lower in response to the stronger vortex at initialization. The size and inner-core structure of each vortex are adjusted closer to observations of these attributes. Addition of reflectivity data in assimilation produces cloud water and rainwater analyses in the initial vortex. The temperature and moisture are also better represented in the hurricane initialization.

Forty-eight-hour forecasts are conducted to evaluate the impact of ADR data using the Advanced Research Hurricane WRF (AHW), a derivative of the Advanced Research WRF (ARW) model. Assimilation of ADR data improves the hurricane-intensity forecasts. Vortex asymmetries, size, and rainbands are also simulated better. Hurricane initialization with ADR data is quite promising toward reducing intensity forecast errors at modest computational expense.
Formation of the Convective Lines off the Mountainous Coast of Southeastern Taiwan: A Case Study of 3 January 2004
Authors: Yu Cheng-Ku , Hsieh Ying-Hsun
Published: March 2009

Convective lines frequently occurring off the mountainous coast of southeastern Taiwan under weakly synoptically forced weather conditions are one of the most well-known mesoscale phenomena in Taiwan. These lines usually develop close to the coast but frequently can also be observed well offshore. While nearshore lines are better understood, the formative processes of the offshore lines remain unclear. The main objective of this study is to use various available observations (e.g., Doppler radar, surface and sounding observations, QuikSCAT, and NCEP data) collected over southeastern Taiwan to investigate a specially chosen case on 3 January 2004, in an attempt to identify possible mechanisms leading to the formation of the offshore lines. The studied line was formed ∼50–60 km away from the southeastern coast of Taiwan and oriented south-southwest to north-northeast and approximately parallel to the coast. Detailed analyses of the event indicated that the formation of the line did not appear directly relevant to coastal land/sea breezes or offshore flow. Instead, orographic forcing was observed to play a crucial role in the initiation of the line. Particularly, an orographically forced northerly flow due to upstream blocking was evident to the west of the line. The convergence generated as the prevailing northeasterly onshore flow encountered the nearshore blocked flow was found to be an important low-level forcing conducive to the initiation of moist convection associated with the line. In addition, the persistence of the coastally blocked flow and the degree of ambient convective available potential energy (CAPE) were also shown to be closely related to the maintenance and overall intensity of the observed line’s convection. The orographically induced convective forcing identified in this study is distinctly different from the conceptual model of line formation proposed by previous studies of the nearshore lines. It is thus strongly suggested that multiple mechanisms may exist upstream of coastal mountains in southeastern Taiwan, which act to initiate the lines with diverse formative locations relative to the coastline.
Cluster Analysis of Cloud Properties over the Southern European Mediterranean Area in Observations and a Model
Authors: Chéruy Frédérique , Aires Filipe
Published: March 2009

This paper demonstrates how satellite observations of the cloudiness over a complex area such as the European Mediterranean area can be classified into distinct cloud regimes by application of a K-means clustering algorithm to pixel-level cloud properties. The study contrasts with previous approaches in the fact that the clustering is done on the cloud physical properties at the pixel level and not on statistics of these properties over a coarser grid. A method to choose the number of clusters is described. “Shallow cumulus,” “stratocumulus,” and “frontal” clusters are robustly identified, and associated environmental properties are described. The approach helps to refine the diagnosis of errors in model simulations. In addition to isolated classical errors of climate models (lack of midlevel clouds, overestimation of the cloud optical thickness, and underestimation of the stratocumulus) and a dramatic underestimation of the shallow cumulus clouds over land, an underestimation of the boundary layer depth is detected for some regimes as well as an incorrect stratification for the shallow cumulus. The clustering on the individual cloud properties classifies them in a much more homogeneous way than the clustering on the statistics of the cloud properties; the use of individual cloud properties at the pixel level produced by climate models activating simulators combined with subgrid-scale sampling procedures may be considered as an alternative to the use of the statistical products for the evaluation of models. The approach can also be applied to a high-resolution regional climate model.
Spiritual-based Leadership in Business
Authors: Pruzan Peter
Published: March 2009

A new global leadership paradigm is gradually emerging, spiritual-based leadership. The article context-ualizes this development within a framework of scientific and economic rationality. In contrast to these, a spiritual approach to leadership is presented as integrating a leader's inner perspective on the purpose of life and leadership such that this inner perspective is the foundation for decisions and actions in the outer world of business. Empirical research is presented, based on interviews with 31 top leaders from 15 countries in six continents. It demonstrates that leaders can obtain happiness, respect, peace of mind and success, while at the same time serving the needs of all those affected by their leadership when they lead from a spiritual basis. It also indicates that spirituality can serve as the foundation for leadership that considers ethics, social responsibility and concern for the environment not just as instruments to protect corporate reputation and income generation but as fundamental principles and values in their own right.