Miracle-dz/UniFAR-FTUs huggingface dataset:
The relationship between seed size and abundance in plant communities: model predictions and observed patterns

Recent studies have suggested that seed size and plant abundance in communities are associated. However, inconsistent patterns have emerged from these studies, with varying mechanisms proposed to explain emergent relationships. We employ a theoretical framework, based on key theory lineages of vegetation dynamics and species coexistence, to examine relationships between species abundance and seed size. From these theory lineages, we identified four models and their predictions: the Seed size/number trade-off model (SSNTM), the Succession model (SM), the Spatial competition model (SCM), and the Lottery model (LM). We then explored empirical evidence from ten diverse plant communities for seed size and abundance patterns, and related these patterns to model predictions. The SSNTM predicts a negative correlation between seed size and abundance. The SM predicts either a negative, positive or no correlation dependent on time since disturbance, while the SCM and LM make no predictions for a relationship between seed size and abundance. We found no evidence for consistent relationships between seed size and abundance across the ten communities. There were no consistent differences in seed size and abundance relationships between communities dominated by annuals compared to perennials. In three of the ten communities a significant positive seed size and abundance correlation emerged, which falsified the SSNTM as an important determinant of abundance structure in these communities. For sites in coastal woodland, the relationships between seed size and abundance were consistent with the predictions of the SM (although generally not significant), with fire being the disturbance. We suggest that the significant positive seed size and abundance correlations found may be driven by the association between large seeds and large growth forms, as large growth forms tend to be dominant. It seems likely that patterns of seed size and abundance in communities are determined by a complex interaction between environmental factors and correlations of plant attributes that determine a species’ strategy.
Reproductive biology in diploid Anthericum ramosum and tetraploid A. liliago (Anthericaceae)

Polyploidy is often thought to be associated with asexual reproduction, self-compatibility and self-pollination. Polyploids are also often regarded as being less sensitive than diploids to the negative effects of inbreeding. The reproductive biology of two lilioid species, the diploid Anthericum ramosum and the tetraploid A. liliago, was compared in a series of greenhouse and field experiments. Pollination experiments were carried out to study agamospermy (seed set without fertilization), self-compatibility and early inbreeding depression for both species. Tetraploid A. liliago showed no greater ability to self-pollinate than diploid A. ramosum and neither of the species showed agamospermy. Both species were self-compatible, but levels of fruit and seed set were lower after self-fertilization than after cross-fertilization in A. ramosum (P<0.001). No reduction in fecundity after self-fertilization was observed in A. liliago. Fruit set in natural populations of A. ramosum increased significantly (P<0.001) after emasculation (which excluded the possibility of autodeposition of pollen within flowers). In contrast, emasculation of flowers reduced the fruit set within natural populations of A. liliago (P<0.05). The reproductive biology of diploid A. ramosum and tetraploid A. liliago is discussed in the context of polyploidization and the reduced fruit and seed set after self-fertilization in A. ramosum is discussed in terms of early inbreeding depression.
Development of a low input system for growing wheat (Triticum vulgare) in a permanent understorey of white clover (Trifolium repens)

In three field experiments carried out during 1989-91, a permanent sward of pure white clover (Trifolium repens) was established to provide a source of N for winter or spring wheat crops (Triticum vulgare) directly drilled into the legume. Spring-sown wheat failed to compete with the clover, but wheat sown in the autumn established successfully. N fertiliser was applied to all three experiments at rates of 0, 50 and 100 kg N ha -1 and measurements of grain and whole-crop silage yields were made. Yields were low for all treatments, probably because of the dry conditions prevailing and the low soil N status of the site used
Linking ecological and hydromorphological data: approaches, challenges and future prospects for riverine science

1. Research linking river ecology and hydromorphology is driven by concerns about hydromorphological pressures (e.g. abstraction, land-use change) and legislative (e.g. EU Water Framework Directive) or management needs (e.g. climate-change adaptation). Unfortunately, much of the science is still weak or qualitative (cf. links between ecology and water quality). 2. Rapid progress is required, but financial resources are limited. In response, research opportunities using existing ecological and hydromorphological data and survey methods need to be explored further. 3. There are challenges inherent in using existing data, which are often collected for different purposes, and this paper highlights aspects of spatial scale, temporal coverage, sampling biases, data quality and mining, and the problems faced when using pre-defined sets of variables. 4. While the prospects for exploiting existing data are mixed, distinct strengths arise from extensive geographic coverage, the ability to improve the evidence base rapidly and at low cost, and the generation of testable hypotheses. 5. Current survey methods usually record biological or hydromorphic patterns, or inventories of features (cf. physical processes, or ecosystem functions or services). Their greatest use is likely to be in extending current spatially extensive biological or water chemistry monitoring to more integrated ‘eco-hydromorphic’ monitoring. 6. With further methodological development, there is real scope for illuminating several aspects of riverine ecology, including the direct ecological and physical consequences of modifying river systems; revealing indirect sensitivity to other pressures, such as climate change; offering a more holistic picture of the distribution of pressures on river ecosystems; and developing hydromorphology as a unifying theme in river studies. However, such developments require funding commitments from research sponsors. Copyright © 2010 John Wiley & Sons, Ltd.
Monitoring the Small and Slimy — Protected Areas Should Be Monitoring Native and Non-Native Slugs (Mollusca: Gastropoda)

ABSTRACT: Although slugs (Mollusca: Gastropoda) are known to be important generalist herbivores, fungivores, and detrivores in a variety of ecosystems, little is known about their abundance and diversity in protected areas. Likewise, the presence of non-native slug species and their impacts on invaded ecosystems have also not been well documented. In this study, the abundance and diversity of native and non-native slugs was investigated in a sensitive protected area comprised of a recently burned black spruce (Picea mariana) - lichen (Cladonia) woodland in Terra Nova National Park, Newfoundland, Canada. To estimate the diversity and abundance of slugs, pitfall traps were established in areas of high-burn intensity, including sites within and at the edge of the burn, low-burn intensity, and a non-burned reference. Of the nine slug taxa known from Newfoundland, five were captured within burned sites; of those five taxa, only one, Deroceras laeve, is native. Almost 90% of captures were of non-native taxa; dominant slug taxa were the introduced Arion subfuscus aggregate (agg.) and A. hortensis agg. The majority of captures occurred at the edge of the burn, and least in the high-intensity open sites. Given that non-native species can dominate the slug fauna in naturally disturbed areas, it is recommended that monitoring for these non-native invasive species and their impact on native vegetation be implemented within protected areas. The invasive nature of non-native slugs and their pivotal role in influencing bio-diversity and plant regeneration suggests that these invertebrates are key elements within a monitoring framework of protected areas.
Pollen types in the Amaranthaceae. Morphology and evolutionary significance

The Amaranthaceae is a family within the order Caryophyllales and comprises approx. 800 species in about 70 genera. A representative selection of 130 species from 67 genera was studied. The pollen was found to be generally pantoporate. High resolution scanning electron microscopy and additional light microscopy revealed many new characters of the apertures, in particular of the ektexinous bodies on the aperture membrane, of the exine microsculpture, of the wall ultrastructure, and information on pollenkitt. The subsequent analysis of the resulting large data set led to the recognition of 17 well defined pollen types. The taxonomic distribution of pollen characters in the Amaranthaceae indicates that pollen morphology is informative at different taxonomic levels. Certain pollen characters can be used to circumscribe genera or groups of genera, and often also to distinguish species. Unique within the angiosperms are the hook‐shaped, stellately arranged ektexinous bodies covering the pore membranes in pollen.
25. The Distribution of Brunner's Glands in the Duodenum of Mammals

Summary. It will be seen that, among the animals examined, there is much diversity in the manner of entry of the pancreatic and bile ducts (see PL I.). There may be a common duct, as in the monkey, sheep, rat, and mouse, or two ducts entering side by side, as in the cat. The bile and pancreatic ducts may be separated by a considerable length of gut, as in the pig, rabbit, and cow, in which case the bile duct is always the higher of the two. An accessory pancreatic duct may be present; this may enter above the common duct, as in man and the stoat, or between the bile and pancreatic ducts, as in the dog and the guinea-pig. With regard to Brunner's glands, these observations on the whole support Villemin's contention that the glands cease where the pancreatic duct enters, whether singly or in common with the bile duct, though small variations about this level are found. In the pig and the guinea-pig, however, the glands extend half a metre or more beyond this level, though the gland mass at the beginning of the duodenum is unusually large in the pig. The Carnivores examined all possess a short compact gland mass, just reaching or falling short of the common duct; but in the dog the mass fails to reach even the bile duct entry. I wish to thank Sir Charles Sherrington and the late Professor Georges Dreyer for facilities accorded me in their departments, Professor Florey and Dr. H. E. Harding, of Sheffield, for the human material, and Colonel Hamerton, C.M. G. , D.S. O. , for animal material from the Zoological Gardens. I also wish to thank Mr. W. Chesterman and Mr. T. Marsland for much help in section-cutting and staining.
EXPERIMENTAL ALLERGIC ENCEPHALITIS

The encephalitogenic determinant of brain protein, a nonapeptide having the amino acid sequence Phe-Ser-Trp-Gly-Ala-Glu-Gly-Gln-Lys, has been characterized and synthesized. In a previous study, analogues of this encephalitogenic peptide were synthesized and some were shown to be encephalitogenic while others were not. Guinea pigs were immunized with encephalitogenic peptides having amino acid sequences different from that in the native protein. These guinea pigs did not show cellular immunity in vivo (skin reactivity) or in vitro (lymphocyte stimulation or macrophage migration inhibition) to the encephalitogenic brain protein (EP) although they did show cellular immunity to the immunizing antigenic peptide. Guinea pigs immunized with an encephalitogenic peptide having the same amino acid sequence as the brain protein, or with a nonencephalitogenic peptide having the same amino acid sequence as the native protein but lacking the terminal lysine, did develop cellular immunity to the EP. Animals immunized with EP showed cellular immunity to this protein, but not to the encephalitogenic peptides. Animals immunized with nonencephalitogenic protein (NEP), prepared by altering the tryptophan residue of EP, did not develop disease but did show cellular immunity in vitro and in vivo to the EP. Animals protected from disease by immunization with NEP similarly showed cellular immunity to EP. Thus, the results suggest a dissociation between cellular immunity to EP and the production of experimental allergic encephalitis (EAE). Animals immunized with the encephalitogenic peptides develop EAE, but do not show cellular immunity to EP, and animals immunized with NEP show cellular immunity to EP but do not develop EAE. A fresh approach to the examination of the pathogenesis of EAE is now possible through the use of these well-characterized antigens.
PHOTORECEPTOR STRUCTURES

The eyes of three eye mutants of Drosophila melanogaster were fixed and thin sections studied for its structural detail in the electron microscope. Each ommatidium was found to have seven retinula cells with an equal number of rhabdomeres (visual units). The rhabdomeres average 1.2 µ in diameter and 60 µ in length. Each rhabdomere consists of osmium-fixed dense bands averaging 120 A in thickness, and with less dense interspaces 200 to 400 A. There is an average of 23 dense bands or 46 interfaces per micron within the rhabdomere. The rhabdomere as we have presented it is a single structure of packed rods or tubes. The "fine structure" within the rhabdomere is similar to that observed by electron microscopy for the retinula of the house fly, and to the retinal rods of the vertebrate eye, and to the chloroplasts of plant cells in a variety of animal and plant photoreceptor structures. In addition, the radial arrangements within the ommatidium of radially unsymmetrical units, the rhabdomeres, is probably related to the analysis of polarized light in the insect eye.
Contribution of Root Respiration to Total Soil Respiration in a Leymus chinensis (Trin.) Tzvel. Grassland of Northeast China

The loss of carbon through root respiration is an important component of grassland carbon budgets. However, few data are available concerning the contribution of root respiration to total soil respiration in grasslands in China. We investigated seasonal variations of soil respiration rate, root biomass, microbial biomass C and organic C content of the soil in a semi-arid Leymus chinensis (Trin.) Tzvel. grassland of northeast China during the 2002 growing season (from May to September). The linear regression relationship between soil respiration rate and root biomass was used to determine the contribution of root respiration to total soil respiration. Soil respiration rate ranged from 2.5 to 11.9 g C/m2 per d with the maximum in late June and minimum in September. The microbial biomass C and organic C content of the soil ranged from 0.3 to 1.5 g C/m2 and from 29 to 34 g C/kg respectively. Root biomass had two peaks, in early June (1.80 kg/m2) and mid-August (1.73 kg/m2). Root respiration rate peaked in mid-August (6.26 g C/m2 per d), whereas microbial respiration rate peaked in late June (7.43 g C/m2 per d). We estimated that the contribution of root respiration to total soil respiration during the growing season ranged from 38% to 76%. (Managing editor: Ya-Qin Han)
Kinetics of cadmium accumulation in periphyton under freshwater conditions

The aim of the present study was to investigate the kinetics of cadmium (Cd) accumulation (total and intracellular) in periphyton under freshwater conditions in a short‐term microcosm experiment. Periphyton was precolonized in artificial flow‐through channels supplied with natural freshwater and then exposed for 26.4 h to nominal Cd concentrations of 5 and 20 nM added to natural freshwater. Labile Cd in water determined with diffusion gradient in thin films was 60 to 69% of total dissolved Cd in the exposure channels and 11% in the control channel. Intracellular Cd concentrations in periphyton increased rapidly and linearly during the first 71 min. Initial intracellular uptake rates were 0.05 and 0.18 nmol of Cd/g of dry weight × min in the 5 nM and 20 nM exposures, respectively. The subsequent intracellular uptake was slower, approaching steady state at the end of Cd exposure. Uptake kinetics of Cd was slower when compared to experiments with planktonic algal cultures, probably due to diffusion limitations. Intracellular Cd uptake during the entire exposure was modeled with a nonlinear, one‐compartment model from which uptake and clearance rate constants, as well as bioconcentration factors, were obtained. The release of Cd from periphyton after the end of Cd exposure was slow when compared to the initial uptake rates.
New promises for manipulation of kynurenine pathway in cancer and neurological diseases

Background: The kynurenine pathway (KP), the primary route of tryptophan degradation in mammalian cells, consists of a cascade of enzymatic reactions eventually leading to NAD+ formation. Many metabolites along the route have biological activities, especially in the nervous and immune systems. Objective/methods: This review focuses on three therapeutic areas, tumor immunoediting, schizophrenia, and Huntington's disease, apparently disconnected but linked by preliminary proof-of-concept of KP involvement. The potential embedded in drug discovery programs aimed at the identification of selective inhibitors with optimized pharmacodynamic and pharmacokinetic properties for human studies is discussed. Results/conclusions: Recent advances have shifted the attention on the kynurenine pathway from a scientific curiosity to a clinically relevant collection of targets. A relatively large number of ligands able to interfere with individual enzymes of the pathway have been made available, but none have so far proceeded into advanced clinical studies.
First record of Chickpea chlorotic dwarf virus (CpCDV) affecting faba bean (Vicia faba) crops in Egypt

A field visit was conducted in March 2002 to identify viruses infecting the faba bean ( Vicia faba ) crop in four governorates (Fayoum, Beni Suef, El-Nobareia and Bihera) in Egypt. A total of 71 faba bean samples with symptoms of viral infection (leaf rolling, yellowing and mosaic) were collected. These were tested at the Virology Laboratory of ICARDA, Syria, for seven viruses using the tissue-blot immunoassay procedure (Makkouk & Comeau, 1994). Specific rabbit polyclonal antisera were used to test for Chickpea chlorotic dwarf virus (CpCDV, genus Mastrevirus , family Geminiviridae ; provided by H. J. Vetten, BBA, Braunschweig, Germany); for Broad bean stain virus (BBSV, genus Comovirus , family Comoviridae ); for Bean yellow mosaic virus (BYMV, genus Potyvirus , family Potyviridae ) and for Pea seed borne mosaic virus (PSbMV, genus Potyvirus , family Potyviridae ). In addition, three specific monoclonal antibodies were used to detect Faba bean necrotic yellows virus (FBNYV, genus Nanovirus , family Nanoviridae ) (Franz et al ., 1996); Bean leaf roll virus (BLRV, family Luteoviridae ) (4B10; Katul, 1992) and Beet western yellows virus (BWYV, genus Polerovirus , family Luteoviridae ) (ATCC PVAS-647; American Type Culture Collection, Manassas, VA, USA). Serological tests showed that BYMV, an aphid-transmitted and seedborne virus that was identified in 89% of samples tested, was the most common virus. In most of the fields surveyed, BYMV symptoms were noted to occur at high levels (80–100% infection). PSbMV was detected in nine samples (one from Fayoum and eight from Beni Suef); FBNYV was detected in 11 samples (all from Beni Suef). CpCDV, a leafhopper-transmitted virus, was, by contrast, detected in only two samples collected from the El-Nobareia governorate showing leaf rolling, yellowing and stunting. BWYV, BLRV and BBSV were not detected in any of the samples tested. In Egypt, FBNYV, BYMV and PSbMV have previously been reported in faba bean (Makkouk et al ., 1994), but this is the first record of CpCDV affecting faba bean in Egypt. CpCDV is the only member of the Geminivirus that is reported to naturally infect faba bean.
Underestimation of rotifer abundance a much greater problem than previously appreciated

Although rotifers are important components of aquatic food webs and suitable sampling methods have been described and tested in the peer‐reviewed literature, they are frequently overlooked or quantified with improper methods (e.g., mesh sizes ≥ 63 µm) in freshwater ecology studies. As a result, we believe that the role of rotifers in aquatic food webs and ecosystem processes remains underappreciated, and this conceptual shortfall is exacerbated by the continued use of improper sampling methodology.We examined density and biomass estimates of metazoan zooplankton in the Upper Mississippi and Missouri rivers from two sampling methods. The macrozooplankton method was designed to target cladocerans, adult and juvenile copepods, by filtering 180 L water through a 63‐µm mesh. The microzooplankton method was designed to target rotifers and copepod nauplii by filtering 18 L water through a 20‐µm mesh. The macrozooplankton method underestimated the density and biomass of common rotifers by two to three orders of magnitude, a far greater amount of error than reported in previous studies. This bias in density estimates for rotifers decreased with increasing mean length of rotifers. The microzooplankton method proved to be ineffective for quantifying cladoceran species richness or cladoceran density at the species level. We urge aquatic ecologists to match their sampling methodology with the specific goals of their study. An accurate understanding of the role of rotifers in freshwater ecosystems will only be possible when the use of appropriate methodology becomes the rule rather than the exception.
Modalités, contraintes et efficacité de la sélection sur descendances de plein-frères chez la vigne (Vitis vinifera L.)

HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L’archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d’enseignement et de recherche français ou étrangers, des laboratoires publics ou privés. Modalités, contraintes et efficacité de la sélection sur descendances de plein-frères chez la vigne (Vitis vinifera L.) Pierre-Louis Lefort, André Bronner
Clostridium coccoides, a New Species from the Feces of Mice

Clostridium coccoides sp. nov. is described on the basis of 12 strains isolated from a number of fecal specimens from mice fed a high-lactose diet. The isolates are obligately anaerobic, gram-positive, sporeforming, nonmotile, coccobacillary to rod-shaped cells which occur singly, in pairs, and sometimes in chains. They differ from other clostridia principally in morphology; the nearly spherical form of the cells, particularly on agar media, is rather distinctive. The guanine plus cytosine (G+C) contents of the deoxyribonucleic acids of the new strains are 43 to 45 mol%, values similar to those of clostridia with high G+C contents, such as Clostridium sphenoides, C. oroticum, C. indolis, C. innocuum, C. barkeri, and C. nexile; however, C. coccoides can be clearly differentiated from these organisms by numerous biochemical characteristics and/or fermentation products. The type strain of C. coccoides is CLC-1 (= ATCC 29236 = NCTC 11035).