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1.
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.
相似文献
Gro GuldenEmail: |
2.
Brad E. Erisman Jorge A. Rosales-Casián Philip A. Hastings 《Environmental Biology of Fishes》2008,82(1):23-33
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.
相似文献
Brad E. ErismanEmail: |
3.
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.
相似文献
Josep CollEmail: |
4.
Richard J. Robins Roland Molinié Renata A. Kwiecień Piotr Paneth Jacques Lebreton Trixie A. Bartholomeusz Albrecht Roscher Birgit Dräger Anna-Carolin Meier François Mesnard 《Phytochemistry Reviews》2007,6(1):51-63
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.
相似文献
Richard J. RobinsEmail: |
5.
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.
相似文献
Stephen A. JarvisEmail: |
6.
7.
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
相似文献
David A. Grahame (Corresponding author)Email: |
Edward DeMoll (Corresponding author)Email: |
8.
Ewa Puchalska Barbara Czajkowska Magorzata Kiekiewicz 《Acta Physiologiae Plantarum》2008,30(2):225-232
Our investigations suggest that the usually observed avoidance by O. ununguis of current year’s twigs of P. glauca ‘Conica’ as a place for feeding and development may be connected with their morphological and anatomical structure as well
their biochemical composition. Needles of the current year’s twigs were covered with a thicker layer of wax and formed more
extensive epidermis cell walls, in comparison with needles of 1-year-old twigs. Young needles also showed lower concentration
of reducing sugars and soluble proteins, which might additionally reduce their nutritional suitability for mite development.
Differences were also found between the 1-year-old growth and current growth in contribution of essential oils and a range
of other compounds. Further analyses of the effect of these compounds on mite behavior may provide additional explanation
of the feeding preferences of the mite.
相似文献
Barbara CzajkowskaEmail: |
9.
Paul F. Cannon Nigel L. Hywel-Jones Norbert Maczey Lungten Norbu Tshitila Tashi Samdup Phurba Lhendup 《Biodiversity and Conservation》2009,18(9):2263-2281
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.
相似文献
Paul F. CannonEmail: |
10.
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.
相似文献
Michael SamishEmail: Email: |
11.
Lucien N’Guessan Kouassi Katsuo Tsuda Chie Goto Shigeyuki Mukawa Yositaka Sakamaki Masayuki Nakamura 《BioControl》2009,54(4):537-548
We compared the infectivity of two nucleopolyhedroviruses (NPVs), MyseNPV G isolated from Mythimna separata (Walker) (Lepidoptera: Noctuidae) and SpltNPV S isolated from Spodoptera litura (Fabricius) (Lepidoptera: Noctuidae). MyseNPV G was more pathogenic against M. separata than against S. litura. Although SpltNPV S was more pathogenic than MyseNPV G against S. litura, it did not infect M. separata. Restriction endonuclease (REN) analysis of viral genomic DNA revealed that the two NPVs have quite different REN profiles.
Based on nucleotide sequences of the coding regions of polyhedrin, lef-8 and lef-9, SpltNPV S was closely related to other SpltNPV isolates, whereas MyseNPV G appeared to belong to the Mamestra NPV group, and was distinct from a Chinese isolate of Leucania (=Mythimna) separata NPV. The potential of MyseNPV G and SpltNPV S to control pest insects is discussed.
相似文献
Katsuo Tsuda (Corresponding author)Email: |
12.
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.
相似文献
Richard W. GriggEmail: |
13.
The interconnection network is one of the key architectural components in any parallel computer. The distribution of the traffic
injected into the network is among the factors that greatly influences network performance. The uniform traffic pattern has
been adopted in many existing network performance evaluation studies due to the tractability of the resulting analytical modelling
approach. However, many real applications exhibit non-uniform traffic patterns such as hot-spot traffic. K-ary n-cubes have been the mostly widely used in the implementation of practical parallel systems. Extensive research studies have
been conducted on the performance modelling and evaluation of these networks. Nonetheless, most of these studies have been
confined to uniform traffic distributions and have been based on software simulation. The present paper proposes a new stochastic
model to predict message latency in k-ary
n-cubes with deterministic routing in the presence of hot-spot traffic. The model has been validated through simulation experiments
and has shown a close agreement with simulation results.
相似文献
Geyong MinEmail: |
14.
Sarah Southwold-Llewellyn 《Human ecology: an interdisciplinary journal》2006,34(5):637-653
Devolution of natural resource management is a widely claimed aim in policy discourse. The Government of Pakistan is undertaking devolution of Provincial Government, including the Provincial Forest Departments. In historical and current practice, forest management has been devolved to local, community-based jirgas. Jirgas achieve some of the aims claimed by devolution which often fail in community-based management organizations. They represent the interests of different asset-based groups and ensure use rights of all for subsistence. However, the internal logic on which they work is based on different principles than those envisaged by policymakers. A case study of Pukhtun agropastoralists in the Malakand Division, North-West Frontier Province, Pakistan, illustrates the jirga's role in forest management and questions some of the assumptions on which community-based management is founded.
相似文献
Sarah Southwold-LlewellynEmail: |
15.
Chi-Li Yu Daniel Ferraro S. Ramaswamy Mark H. Schmitz Wayne F. Schaefer David T. Gibson 《Environmental Biology of Fishes》2008,82(1):51-58
A blue protein present in the mucus coating blue forms of walleye, Sander vitreus, was purified to homogeneity by a combination of ion exchange and hydrophobic interaction chromatography. The purified protein
has a molecular mass of 87,850 and is a homotetramer with a subunit molecular mass of 21,836. Solutions of the protein are
deep blue in color and show absorbance maxima at 383 and 633 nm, respectively. Acetone treatment of the protein releases a
blue chromophore with the spectral characteristics of biliverdin IXα. The results suggest that the blue protein is a new biliprotein
that we have termed Sandercyanin. The function of Sandercyanin is unknown, but limited amino acid sequence analysis suggests
it is a lipocalin that may be involved in the transport of heme degradation products.
相似文献
David T. GibsonEmail: |
16.
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.
相似文献
Stanford ZentEmail: |
17.
M. Irfan-Ullah Giriraj Amarnath M. S. R. Murthy A. Townsend Peterson 《Biodiversity and Conservation》2007,16(6):1917-1925
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.
相似文献
M. Irfan-UllahEmail: Email: |
18.
Jonathan J. Goin Thomas H. Williams Christopher J. Donohoe 《Environmental Biology of Fishes》2008,82(3):207-213
Vertebral counts in fishes are set early in development by a complex interaction of genetic and environmental factors. Recently,
R. M. McDowall showed that vertebral counts can differ between diadromous and non-diadromous galaxiids, and suggested similar
life history-based variation might also occur in the closely related Salmonidae. We examined variation in vertebral counts
of juvenile rainbow trout, Oncorhynchus mykiss, from within a single large basin where anadromous and non-anadromous forms co-occur. Juveniles were collected at 29 sites
within the Klamath River basin using a nested sampling design. Mean vertebral counts varied among regions, among complexes
within regions, and among sites within complexes. Regression showed that mean vertebral counts decreased with increasing distance
from the ocean. This decrease could not be explained by differences in temperature within the basin during early development.
However, the decrease is consistent with the expectation that non-anadromous forms have fewer vertebrae and are more common
at sites distant from the ocean, and suggests that further study of the relationship between vertebral counts and life history
form in O. mykiss is warranted.
相似文献
Thomas H. WilliamsEmail: |
19.
David Michael Drew Geoffrey M. Downes Valerie Grzeskowiak Thimagren Naidoo 《Trees - Structure and Function》2009,23(3):585-595
Understanding daily stem size variation is important as the net increment of a forest stand is ultimately determined by the
accumulation of daily increment events. In this study, measurements of stem size at high spatial and temporal resolution were
made using two commercial hybrid Eucalyptus clones [E. grandis × urophylla (GU) and E. grandis × camaldulensis (GC)] over a period of more than 3.5 years in order to better understand how daily stem growth is effected by variations
in environmental conditions. It was evident that GU had fewer days on which net growth occurred than GC. However, when growth
did occur, GU grew for longer each day and at a higher rate than GC. Thus, it still had an overall larger net stem increment
during the study period. The GU clone had a markedly intermittent pattern of growth, such that growth essentially ceased under
drought conditions, but responded rapidly when water became available. This confirms other findings that E. grandis × urophylla is more susceptible to drought stress than E. grandis × camaldulensis, but emphasizes that a strategy of “rapid response” when environmental conditions become temporarily non-limiting is a good
one in terms of net increment at sites such as in this study.
相似文献
David Michael DrewEmail: |
20.
We surveyed slender lorises (Loris lydekkerianus) in Karnataka, south India intermittently during November 2001–July 2004 and estimated their relative abundance via direct sightings. Two subspecies, Loris lydekkerianus lydekkerianus and L. l. malabaricus, with different morphological traits, occur in the eastern drier region and the western wet region of the state, respectively. The distribution of Loris lydekkerianus lydekkerianus is patchy in a small region in the southeast, which contradicts earlier reports of its abundance throughout the state. Loris lydekkerianus malabaricus occurs throughout the Western Ghats as a contiguous population. The encounter rates of Loris lydekkerianus lydekkerianus and L. l. malabaricus are 0.41 individuals/km and 0.21 individuals/km, respectively. Whereas several forest tracts in the distributional range of Loris lydekkerianus malabaricus are protected areas, no such area exists in the distributional range of L. l. lydekkerianus. Loris lydekkerianus faces serious challenges of conservation because it largely occurs in commercial plantations, which can be relatively unstable habitats as harvesting can take place at any time.
相似文献
Mewa SinghEmail: |