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The sexual pattern and sexual development of the leopard grouper, Mycteroperca rosacea, were investigated from 483 specimens collected from the Gulf of California, Mexico. Histological and population data indicated a gonochoric sexual pattern. Some juveniles passed through an immature bisexual phase of gonadal development, but no evidence of post-maturational sex change was found. The immature bisexual phase is believed to be associated only with male development. The size distribution and size at sexual maturity were similar for both males and females. In accordance with predictions of the size-advantage model, the gonochoric sexual pattern of M. rosacea is likely influenced by its group-spawning mating system.
Brad E. ErismanEmail:
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In 2001 Carijoa riisei, an octocoral native to the tropical Western Atlantic, was discovered overgrowing black corals in the Au’au Channel in Hawaii. In this paper data from a 2001 survey are reanalyzed and combined with new data from 2003 and 2004 to assess the ecological impact in greater detail. C. riisei differentially affected reproductively mature black coral colonies with maximum impact between 80 and 105 m. The pattern of C. riisei overgrowth on black corals and C. riisei on the substrata appears to be bounded by high irradiance in shallow water and cold temperature in deep water. Evidence suggests that the C. riisei settlement on black corals is facilitated by other epifauna. Once established, C. riisei spreads vegetatively and smothers the coral. The success of the C. riisei invasion appears to be unaided by anthropogenic disturbance and is at least partially attributable to Hawaii’s depauperate shallow-water (<100 m) octocoral fauna.
Richard W. GriggEmail:
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5.
The insect-pathogenic fungus Ophiocordyceps sinensis (better known as Cordyceps sinensis) is harvested over much of the Himalayan plateau as a highly prized remedy in traditional Oriental medicine. Over the past 10 years its financial value has increased dramatically, with collectors paid as much as US $12,500 kg−1 for top-quality material. This is causing significant distortion to local economies, and there is widespread concern that the current rate of collection is unsustainable. This paper introduces the fungus and its insect hosts, documents some of the biological and social constraints to achieving sustainability, describes the socioeconomic climate within which harvest and sale occurs in Bhutan, and details the measures put in place by the Royal Government of Bhutan to promote wise management of this valuable natural resource.
Paul F. CannonEmail:
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Sub-Antarctic Marion Island has had a permanent research station for 50 years and the islands Wandering Albatrosses have been intensively studied for 20 years. The reactions of breeding birds to approaches by a human on foot were recorded. Three response variables were calculated: intensity of vocal reaction (IVR), intensity of non-vocal reaction (INR) and overall response index (ORI). At 5 m from the nest, twice as many birds stood and/or vocalised as at 15 m. Nearest neighbour distance, age and gender did not explain individual variability of responses. Study colony birds had higher IVR scores than non-study colony birds; birds at colonies closest to the station had the highest ORI scores. A better breeding record was associated with lower IVR and ORI scores, but a causative relationship remains to be demonstrated. A minimum viewing distance of 25 m is recommended for breeding Wandering Albatrosses.
Marienne S. de VilliersEmail: Fax: +27-21-6503434
John CooperEmail:
Peter G. RyanEmail:
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8.
Predictive performance modelling of parallel component compositions   总被引:1,自引:0,他引:1  
Large-scale scientific computing applications frequently make use of closely-coupled distributed parallel components. The performance of such applications is therefore dependent on the component parts and their interaction at run-time. This paper describes a methodology for predictive performance modelling and evaluation of parallel applications composed of multiple interacting components. In this paper, the fundamental steps and required operations involved in the modelling and evaluation process are identified—including component decomposition, component model combination, M×N communication modelling, dataflow analysis and overall performance evaluation. A case study is presented to illustrate the modelling process and the methodology is verified through experimental analysis.
Stephen A. JarvisEmail:
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9.
Methanogens growing on C-1 substrates synthesize 2-carbon acetyl groups in the form of acetyl-CoA for carbon assimilation using the multienzyme complex acetyl-CoA decarbonylase/synthase (ACDS) which contains five different subunits encoded within an operon. In species growing on acetate ACDS also functions to cleave the acetate C-C bond for energy production by methanogenesis. A number of species of Methanosarcina that are capable of growth on either C-1 compounds or acetate contain two separate ACDS operons, and questions have been raised about whether or not these operons play separate roles in acetate synthesis and cleavage. Methanosarcina thermophila genomic DNA was analyzed for the presence of two ACDS operons by PCR amplifications with different primer pairs, restriction enzyme analyses, DNA sequencing and Southern blot analyses. A single ACDS operon was identified and characterized, with no evidence for more than one. MALDI mass spectrometric analyses were carried out on ACDS preparations from methanol- and acetate-grown cells. Peptide fragmentation patterns showed that the same ACDS subunits were present regardless of growth conditions. The evidence indicates that a single form of ACDS is used both for acetate cleavage during growth on acetate and for acetate synthesis during growth on C-1 substrates. Electronic Supplementary Material  Supplementary material is available for this article at
David A. Grahame (Corresponding author)Email:
Edward DeMoll (Corresponding author)Email:
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10.
The reaction of N-demethylation plays an important role in the degradation of some alkaloids in a number of organisms. This review presents how our understanding of the N-demethylation of nicotine in plants has been improved through studies in cell cultures of Nicotiana plumbaginifolia and N. glutinosa using a variety of isotopic techniques. The overall aim is to understand how metabolism recycles the alkaloid skeleton, both in terms of the metabolic route(s) exploited and the reaction mechanisms of the enzymes involved. The former has been approached using high-resolution 2-dimensional NMR and GC-MS methods; the latter by determining kinetic isotope effects and modelling the potential reaction steps. It appears that the mechanism for nicotine demethylation in plants is similar to but has significant differences from that described for mammals and Pseudomonas bacteria. These differences are discussed.
Richard J. RobinsEmail:
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11.
A key point in the analysis of dynamical models of biological systems is to handle systems of relatively high dimensions. In the present paper we propose a method to hierarchically organize a certain type of piecewise affine (PWA) differential systems. This specific class of systems has been extensively studied for the past few years, as it provides a good framework to model gene regulatory networks. The method, shown on several examples, allows a qualitative analysis of the asymptotic behavior of a PWA system, decomposing it into several smaller subsystems. This technique, based on the well-known strongly connected components decomposition, is not new. However, its adaptation to the non-smooth PWA differential equations turns out to be quite relevant because of the strong discrete structure underlying these equations. Its biological relevance is shown on a 7-dimensional PWA system modeling the gene network responsible for the carbon starvation response in Escherichia coli.
Laurent Tournier (Corresponding author)Email:
Jean-Luc GouzéEmail:
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12.
We tested the pathogenicity of 18 Metarhizium anisopliae (Metschn.) Sorokin isolates and 22 Beauveria bassiana (Balsamo) Vuillemin isolates against Alphitobius diaperinus (Panzer) (Coleoptera: Tenebrionidae) larvae and adults. The efficacy of the most virulent isolate—M. anisopliae K—was evaluated in containers with a concrete bottom covered with wood shavings, under simulated poultry house conditions. Application of conidia of this isolate to the shavings or directly to the concrete bottom reduced the yield of larvae in 8–15 time compared with the control. In another test, the mortality of mature larvae placed on previously inoculated shavings or bottom reached 80–90% within 14 days, compared with 14% in the control. The residual activity of conidia kept at 28°C retained its initial level during 14 days post-inoculation, but declined after three weeks. Based on our data M. anisopliae has considerable potential for the control of A. diaperinus.
Michael SamishEmail: Email:
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13.
We examined the influence of crop management (crop density, nitrogen fertilization level) and landscape parameters [areal proportion of oilseed rape (OSR), Brassica napus L. var. oleifera Metzg. (Brassicaceae), and proportions, lengths and distances of various non-crop habitats] on the parasitism of stem weevils (Ceutorhynchus spp.; Coleoptera: Curculionidae) and pollen beetles (Meligethes spp.; Coleoptera: Nitidulidae) by parasitic wasps (Hymenoptera: Ichneumonidae). Larvae of host insects were sampled in 29 winter OSR fields located in landscapes ranging from structurally simple to complex. Spatial scales of landscape effects were considered at eight radii (250–2,000 m) centered in the studied OSR fields. Stem weevil parasitism was unaffected by crop management variables but negatively related to roadside strip length at radius 250 m and grassy fallow area at a radius of 500 m. Pollen beetle parasitism was positively related to the crop density and to lengths of roadside strips and hedges within a radius of 250 m. Thousand kernel mass of OSR was positively related to pollen beetle parasitism but unrelated to stem weevil parasitism.
Johann G. ZallerEmail:
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14.
The recent contribution by Jarmila Kukalová-Peck on Hennigian phylogenetics and hexapod limb evolution is critically evaluated.
Michael S. Engel (Corresponding author)Email:
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15.
Mycena aphanes and Mycena exilis, belonging to section Filipedes and section Polyadelphia, are proposed as new species. They are described and illustrated and compared to other species in the two sections. Mycena aphanes is a strikingly characteristic Mycena with fulvous or yellowish brown colours of both pileus and stipe. Mycena exilis is characterized by its occurrence on fallen Salix leaves, a pale brown pileus, occasionally with a pale pink tinge, narrowly adnate lamellae, four-spored basidia, and the presence of clamp connections.
Gro GuldenEmail:
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16.
Aglaia bourdillonii is a plant narrowly endemic to the southern portion of the Western Ghats (WG), in peninsular India. To understand its ecological and geographic distribution, we used ecological niche modeling (ENM) based on detailed distributional information recently gathered, in relation to detailed climatic data sets. The ENMs successfully reconstructed key features of the species’ geographic distribution, focusing almost entirely on the southern WG. Much of the species’ distributional potential is already under protection, but our analysis allows identification of key zones for additional protection, all of which are adjacent to existing protected areas. ENM provides a useful tool for understanding the natural history of such rare and endangered species.
M. Irfan-UllahEmail: Email:
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17.
The maintenance of exceptionally high numbers of folk varieties by the Piaroa people of the Venezuelan Amazon is considered. We cataloged 113 manioc folk varieties, their nomenclature, use and relevant characters, revealing significant insights into the role of manioc in Piaroa social life. Through a qualitative investigation of the cultivation, processing and symbolic significance of manioc (Manihot esculenta) in two Piaroa regions over a period of 18 years, we have found that such agrobiodiversity can only be fully explained by a combination of multiple factors, including pragmatic and ecological considerations, the subtle and complex diversity of Piaroa manioc preparations and a variety of sociocultural factors, such as manioc’s role as a mediator of social relationships and as a marker of cultural and social heritage.
Stanford ZentEmail:
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18.
Levoglucosan, cellulosic pyrolysate, is converted to glucose-6-phosphate by a specific levoglucosan kinase in fungi. A novel cDNA of levoglucosan kinase gene (lgk) from yeast Lipomyces starkeyi YZ-215 was isolated by RACE method. The 1,445 bp cDNA fragment (lgk) harbouring the kinase gene exhibited one open reading frame (ORF) composed of 1,317 bp flanked by a 14 bp 5′-UTR and a 114 bp 3′-UTR, including a 25 bp poly(A) tail. The ORF encoded a 439 amino acid polypeptide with a 48.4 kDa predicted molecular mass. Analysis of amino sequence revealed that the kinase belonged to the bacterial anhydro-N-acetylmuramic acid kinase (AnmK) family, and kinase-like proteins existed in some fungi, especially in filamentous fungi such as Aspergillus. The kinase gene was transformed into Escherichia coli BL21 (DE3), recombinant E. coli could grow in M9 minimal medium with levoglucosan as a sole carbon source when induced by IPTG. In addition, the recombinant kinase was overexpressed, purified and characterized. The kinase was stable at pH 7–10 and showed maximum activity at 30°C and pH 9.0 as natural kinase, but presented higher thermostability. Kinetic constants (apparent K m values) for LG and ATP were 105.3 ± 12.5 and 0.20 ± 0.02 mM, respectively. Furthermore, the kinase showed substrate specificity for LG. This novel levoglucosan kinase gene would be useful in constructing recombinant microbial strains for the efficient bioconversion of cellulosic pyrolysate to ethanol.
Zhisheng YuEmail:
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The presence of several types of allelochemicals has been reported from Ajuga, a Labiatae genus comprising more than 40 species of wide distribution in extratropical regions of both hemispheres. The genus is of great medicinal and economic importance and among the biological properties of the secondary metabolites, the antifeedant activity against pest insects appears to be related to the presence of neo-clerodane type diterpenes. This review focuses on the isolation and structural elucidation of this type of compounds from Ajuga species and the hemisynthetic compounds of closely related structure obtained. The reported biological activity of crude extracts and isolated diterpenes will be briefly commented.
Josep CollEmail:
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