Miracle-dz/UniFAR-FTUs huggingface dataset:
Temporal and spatial distribution of the dinoflagellate Ceratium hirundinella O. F. Muller within a small productive lake

Summary The growth of Ceratium hirundinella in Esthwaite Water, a small productive lake, was investigated during 1975; the horizontal distribution of the alga was studied on four occasions over a 3-week period. Measurements of lake temperature, oxygen concentration, and vertical stratification of Ceratium at close intervals of depth, were also made. Lake population estimates from large samples at many stations were compared with small samples at the regular sampling station. On two occasions the means of these samples were significantly different (P<0·01). On one date, the estimate of Ceratium abundance in the lake from the large sample at many stations was more than twice the value obtained from the sample collected at the regular sampling station. The population of Ceratium was contagiously distributed in all the large samples. On 3 days the horizontal distribution showed an increase in Ceratium numbers towards the windward shore of the lake. Very large accumulations of Ceratium were found in the metalimnion, just above the anaerobic hypolimnion, during late afternoon. Possible mechanisms of horizontal pattern development are considered, based on the measurements of the vertical distribution of Ceratium, and meteorological factors. The ecological consequences for Ceratium of vertical and horizontal movements, and its spatial distribution in the lake, are discussed.
Atmospheric CO2 fluxes in a highly polluted estuary (the Scheldt)

Dissolved CO 2 concentration and exchange with the atmosphere were investigated simultaneously in the Scheldt estuary. CO 2 partial pressures as high as 5,700 μatm, corresponding to oversaturation with respect to the atmosphere of 1,600%, were observed in the upper estuary. The corresponding atmospheric CO 2 fluxes reached values of up to 1.2 mol m -2 d -1 . The estimated flux for the entire estuary amounts to 600 t of C d- ' for a river discharge of < 1 X 10 6 m 3 d -1 .
Sex and the single mustard : population density and pollinator behavior effects on seed-set

The local density of a plant population can influence both the number of pollinators attracted and the behavior (and thus pollination efficiency) of those that are. I present the results of a field experiment performed on Brassica kaber, a self—incompatible annual crucifer, designed to test for the existence of density effects in pollination and to separate the two major component effects: reductions in the quantity and in the quality of pollinator services. B. kaber plants were grown in fan—shaped density arrays in six floral backgrounds chosen to manipulate pollinator foraging behavior. Pollinators visiting focal plants behaved as generalists in backgrounds of the similar—flowered Brassica hirta, behaved as floral specialists where no alternative floral resources were provided (three treatments), and displayed a mixture of behaviors in two background plantings where dissimilar flowers were available. Pollinator visitation rates to focal B. kaber plants declined sharply at low density in all backgrounds except the similar flower (B. hirta) treatment. Widely spaced plants displayed significantly reduced seed—set in all backgrounds studied. The most dramatic density effects occurred where pollinators were induced to behave as generalists, suggesting that density—related declines in pollinator quality are more important than parallel declines in the quantity of visits.
Pathogen impacts on plant communities: unifying theory, concepts, and empirical work

Pathogens, like other consumers, mediate the outcome of competitive interactions between their host species. Ongoing efforts to integrate pathogens into plant community ecology could be accelerated by greater conceptual unification. Research on plant pathogens has mainly focused on a variety of disparate mechanisms—the Janzen-Connell hypothesis, plant–soil feedbacks, competition–defense trade-offs, escape of invasive plants from their enemies, and epidemic-driven community shifts—with limited recognition of how these mechanisms fit into the broader context of plant coexistence. Here, I extend an emerging theoretical framework for understanding species coexistence to include various pathogen impacts on plant communities. Pathogens can promote coexistence by regulating relative abundance or by reducing the disparities between species in fitness that make coexistence more difficult. Conversely, pathogens may undermine coexistence by creating positive feedbacks or by increasing between-species fitness differe.
Variability of intra‐ and interspecific competitions of bamboo stump mosquito larvae over small and large spatial scales

We carried out field experiments to examine the variability of interspecific competition of mosquito larvae among microcosms in a bamboo grove (small spatial scale) and between bamboo groves at two sites, with single and multiple mosquito species (large spatial scale). Four types of microcosms that differed in capacity and litter input were set. In the hillside bamboo grove, where multiple species occurred, succession of the predominant species from Aedes albopictus to Tripteroides bambusa was observed in control microcosms from which no mosquito larvae were removed. Weekly removal of competitive species resulted in increased pupation of A. albopictus and adult body weight under both rich and poor resource conditions. In the late period of the experiments, the effect of competitor removal on pupation of A. albopictus was greater in deep containers that never dried than in shallow containers that were dried in the laboratory. The number of eggs showed a slight difference between competitor-excluded and deep control microcosms. These results indicate that interspecific competition limits pupation of A. albopictus more strongly in deep containers than in shallow and drought-prone containers. Compared with the hillside site, the larval density of A. albopictus attained a higher density in the bamboo grove in the plain where no competitive species occurred, due to a higher oviposition rate. Lower rate of pupation and lower adult weight at the plain site than at the hillside site indicated that resource limitation was more severe at the plain site. Populations of A. albopictus at hillside and plain sites appeared to suffer from strong inter- and intraspecific competition, respectively. At the hillside site, the intensity of interspecific competition appeared to increase later in the breeding season, with a high larval density of T. bambusa. In contrast, at the plain site, intensity of intraspecific competition appeared to be reduced later in the breeding season with decreasing larval density of A. albopictus.
Preliminary investigation on the phytoplankton contribution to the mussel diet on the basis of fatty acids analysis

The composition of fatty acids was studied in the mussels collected in the Mar Grande of Taranto (northern Ionian Sea) during the four seasons. Micro-, nano- and picophytoplankton abundance, biomass and composition have been also evaluated. Fatty acids compositions were investigated for lipid biomarkers to establish the contribution of phytoplankton to the mussel diet. Saturated (SAFA) and monounsaturated fatty acids (MUFA) were the most abundant components, followed by polyunsaturated fatty acids (PUFA). The seasonal variations in the SAFAs, MUFAs and PUFAs were not significantly different during the whole study period (ANOVA, P < 0.05). The most abundant identified FAs were 16:0 (27.51–33.80% of total FAs), 14:1 (3.35–9.91% of total FAs), 18:1n9 (2.92–8.87%), 16:1 n7 (4.53– 7.61%) and 24:1n9 (0.43–8.84%). The most important PUFAs were 22:2 (2.35–3.48% of total FAs) and also 18:2n-6 (1.66–2.61%). PUFAs were characterized by low percentages of n3 and n6 FAs. Analysis of specific FA markers for diatoms (16:1n7, 20:5n3), phytoflagellates and dinoflagellates (16:0, 18:4n3) showed a negligible contribution of phytoplankton to the mussel diet.
Rapid soil development after windthrow disturbance in pristine forests

Summary I We examined how rapidly soils can change during secondary succession by observing soil development on 350-year chronosequences in three pristine forest ecosystems in south-east Alaska. 2 Soil surfaces, created by different windthrow events of known or estimated age, were examined within each of three forest stands (0.5-2.0 ha plots; i.e. a within-stand chronosequence method). Soil surfaces are more likely to have developed under common climate and vegetation conditions within stands than in the spatially separated ecosystems used in traditional chronosequence studies. 3 We observed rates of change that were higher than those previously reported for secondary succession, and were similar to those described for primary succession. Well-developed spodic and albic (podzol) horizons with characteristic C, Fe, and Al signatures were found in soil surfaces less than 150 years old. Carbon accumulated linearly at 21 g m -2 year -1 ; mineral P and N became increasingly immobilized in the spodic horizon as time passed. We found no trend toward an equilibrium in C or N accumulation over the 350-year chronosequences in any of the three stands examined. 4 These rapid changes in soil and a shift in rooting from mineral to organic horizons appeared likely to reduce productive capacity of the soil during a single generation of trees. Windthrow or disturbances that mimic windthrow may be required at intervals of about 200-400 years to maintain soil productive capacity in these ecosystems.
Exogenous ABA as a Modulator of the Response of Sorghum to High Salinity

Treatment of Sorghum bicolor (L.) Moench, cv. 610, with abscisic acid (ABA) during the first week of salinization with 150 mol m"3 NaCl induced enhancement of growth and accelerated adaptation to high salinity (300 mol m ~3 NaCl). Adaptation is defined as the development of the ability of the plant to survive, grow, and set seeds upon exposure to a NaCl concentration which is lethal for the unadapted plant. In the absence of ABA the saline pretreatment requires 20 d for the development of adaptation (Amzallag et al., 1990); with ABA treatment the same result is achieved within approximately one week. The exposure of the plants to non-lethal salinity (150 mol m-3 NaCl) apparently triggers a transient sensitivity to ABA lasting for about 8 to 10 d following the beginning of salinization. This period coincides with an increase in leaf PEP carboxylase activity which seems to occur faster if the plants are treated with ABA. Exogenous ABA-induced enhancement of growth and control of shoot Na + concentration, occur at a lower ABA concentration («10 mmol m~3) than the induction of adaptation to salinity which occurs at «40 mmol irT3 or above. The lowered shoot Na+ concentration which is induced by a low ABA concentration is not sufficient to induce survival of the plants in high salinity (300 mol m'3 NaCl).
Mycoplasma elephantis sp. nov., a new species from elephants

Organisms with the typical characteristics of mycoplasmas were isolated from the genital tracts of female elephants. The results of growth inhibition tests, metabolic inhibition tests, indirect immunofluorescence tests, and immunobinding assays showed that the isolated mycoplasmas were identical and distinct from previously described Mycoplasma, Entomoplasma, Mesoplasma, and Acholeplasma species. These organisms represent a new species, for which the name Mycoplasma elephantis is proposed. M. elephantis ferments glucose, fructose, maltose, mannose, and sucrose, produces films and spots, does not hydrolyze arginine, esculin, and urea, does not reduce methylene blue, tetrazolium chloride, and potassium tellurite, does not possess phosphatase activity, and reduces resazurin. It lyses avian, ovine, and guinea pig erythrocytes. It does not adsorb erythrocytes. Cholesterol or serum is required for growth. The optimum growth temperature is 37°C. The G+C content of the DNA is 24.0 mol%. The type strain of M. elephantis is E42 (= ATCC 51980).
EVALUATION OF ANTAGONISTIC ACTIVITY OF SOIL BACTERIA AGAINST PLANT PATHOGENIC FUNGI

The purpose of this research was to evaluate antagonistic activity of some bacteria isolated from soil. Bacteria are able to synthesise a wide range of secondary metabolites with fungicidal capabilities. The antagonistic potential of five soil bacterial strains (E. coli, Baccillus fortis, B. faragiris, Pseudomonas fluorescens and P. malophilia) was assessed in vitro against Alternaia alternate, A. citri, Aspergillus aculatus, A. japonicus, Dreshlera biseptata. The result indicated that tested bacterial species exhibited varying degree of antagonistic potential against all pathogenic fungi. Pseudomonas malophilia showed maximum inhibitory potential against all tested fungi with reduction of up to 60% in fungal colony diameter. Results also showed that Pseudomonas fluorescens and Bacillus fortis exhibited almost similar biocontrol potential against three pathogenic fungi viz. Aspergillus aculatus, A. japonicus and Dreshlera biseptata. On other hand, Escherichia coli showed least effective biocontrol prospective against A. citri, Aspergillus aculatus and Dreshlera biseptata, where it reduced the fungal growth from 5 to 12 %. Results indicated that tested bacterial species can be used as promising biocontrol agent.
Characterization of Grateloupia lanceola (Halymeniales, Rhodophyta), an obscure foliose Grateloupia from the Iberian Peninsula, based on morphology, comparative sequence analysis and mycosporine-like amino acid composition

Foliose Grateloupia species are among the most commonly reported introduced species of red algae in European waters. Unequivocal identification at species level, however, has proven exceedingly difficult owing to a relatively low number of clear-cut diagnostic characters and considerable morphological plasticity. Because of their morphological similarity many of these species were placed in synonymy by subsequent generations of phycologists. In the present paper we demonstrate that Gratelopia lanceola, a native European species, is distinct from G. turuturu, a western Pacific alga introduced in European waters. These conclusions are based on comparative gene sequences (rbcL and LSU rDNA) as well as morphology and mycosporine-like amino acid (MAA) signatures. Even though support was largely lacking from rbcL and the combined analysis, G. lanceola was clearly separated from G. turuturu as well as other foliose species. These data, together with earlier accounts on genuine G. doryphora and G. schizophylla, indicate that foliose Grateloupia species display a clear geographic structuring, which has only become obscured by the recent introduction of morphologically similar species (pseudo-cryptic species) along Atlantic coasts and in the Mediterranean Sea. Grateloupia lanceola also showed a different MAA composition when compared with G. turuturu, regardless of spatial-temporal influences. The concentrations were about 3 mg g−1 DW and about 5 mg g−1 DW in G. turuturu and G. lanceola, respectively. The main MAA in Grateloupia lanceola was porphyra-334, which represented almost 100% of these compounds. Only some traces (<1%) of shinorine and palythine were found in this species. On the other hand, the dominant MAA in G. turuturu was shinorine, which represented approximately 92% of the total MAA content; palythine contributed about 7.5% while traces of asterina-330 were also found.
Phylogeny, evolutionary history and taxonomy of the Mustelidae based on sequences of the cytochrome b gene and a complex repetitive flanking region

The Mustelidae is a diverse family of carnivores which includes weasels, polecats, mink, tayra, martens, otters, badgers and, according to some authors, skunks. Evolutionary relationships within the family are under debate at a number of different taxonomic levels, and incongruencies between molecular and morphological results are important. We analysed a total of 241 cytochrome b (cyt b) gene sequences and 33 sequences of a complex repetitive flanking region from 33 different species to compile an extensive molecular phylogeny for the Mustelidae. We analysed these sequences and constructed phylogenetic trees using Bayesian and neighbor‐joining methods that are evaluated to propose changes to the taxonomy of the family. The peripheral position of skunks in phylogenetic trees based on both loci suggests that they should be considered a separate family, Mephitidae. The subfamily Melinae is the basal group within the Mustelidae and trees based on the cyt b gene suggest that the American badger, Taxidea taxus, should be considered a separate monotypic subfamily, Taxidiinae. Otters classified within the genera Lutra, Amblonyx and Aonyx are grouped within the same clade in cyt b and combined partial cyt b and flanking region trees and show reduced levels of inter specific divergence, suggesting that they could be classified together under a single genus, Lutra. The Bayesian tree based on combined data from both loci supports the idea that subfamily Mustelinae is paraphyletic, as otters (subfamily Lutrinae) are included in this subfamily. Low levels of genetic divergence among European polecat, Mustela putorius, steppe polecat, Mustela eversmannii, and European mink, Mustela lutreola, suggest that these species could be considered subspecies within a single species, Mustela putorius. Our results are consistent with a rapid diversification of mustelid lineages in six different radiation episodes identified since the Early Eocene, the oldest events being the separation of subfamilies and the split of marten (Martes, Gulo) and weasel (Mustela) lineages in the Early Middle Miocene. The separation of New World from Old World lineages and the split of the remaining genera are estimated to have occurred in Late Miocene. The most recent events have been the differentiation of species within genera and this probably occurred in four radiation episodes at the end of Late Miocene, Early Pliocene, Late Pliocene and Pleistocene epochs.
Effects of sex and population density on dispersal and spatial genetic structure in brush mice

Abstract Natal dispersal, the process of moving between the natal site and the site of 1st reproduction, affects a variety of ecological and evolutionary processes. Multiple factors have been suggested to influence patterns of natal dispersal in vertebrates; sex and population density are 2 of the most frequently invoked. In mammals, males are typically expected to disperse farther or more frequently than females. In contrast, theoretical predictions about the effect of population density are less clear, and support exists for both positive and negative density-dependent dispersal. Here, I investigate the influences of sex and population density on dispersal distances and spatial genetic structure (SGS) in the brush mouse (Peromyscus boylii), using both intensive field surveys and spatial genetic autocorrelation methods. Neither density nor sex affected dispersal distances. I did detect increased genetic structure in females compared to males, a pattern consistent with male-biased dispersal. However, processes other than dispersal can generate SGS, and I suggest that in addition to sex-biased dispersal, these results also could reflect gene dispersal via mating excursions. No clear effect of population density on either dispersal distance or SGS emerged. These results highlight the importance of using multiple methodologies to investigate dispersal. Resumen Dispersión natal, el proceso de traslado entre el sitio de nacimiento y el sitio de la primera reproducción, afecta una variedad de procesos ecológicos y evolutivos. Se han sugerido múltiples factores que pueden influenciar los patrones de dispersión natal en vertebrados; el sexo y la densidad de la población son los 2 factores más frecuentemente invocados. En los mamíferos, típicamente se espera que los machos se dispersen más lejos y más frecuentemente que las hembras. En contraste, las predicciones teóricas acerca del efecto de la densidad poblacional no son tan claras, y existe apoyo para ambas formas de dispersión dependiente de la densidad, positiva y negativa. Aquí, investigo la influencia del sexo y la densidad poblacional en las distancias de dispersión y la estructura genética espacial en el ratón de maleza (Peromyscus boylii), usando estudios de campo intensivos y métodos de auto correlación genética. Ni la densidad ni el sexo afectaron la distancia de dispersión. Detecté una elevada estructura genética de las hembras comparada con la de los machos, un patrón consistente con la expectación típica de la dispersión masculina. Sin embargo, procesos diferentes a la dispersión pueden generar estructura genética espacial, y yo sugiero que además a la dispersión sesgada por sexo, los resultados también pueden reflejar dispersión de genes a través de excursiones de apareamiento. No se apreciaron efectos de la densidad poblacional en la distancia de dispersión o en la estructura genética espacial. Estos resultados demuestran la importancia del uso de múltiples métodos para investigación la dispersión.
Conversion of immunity to suppression by in vivo administration of I-A subregion-specific antibodies

The in vivo administration of antibodies specific for gene products of the I-A subregion represents an immunologically specific approach to the manipulation of Ly-1+ T cell responses to antigen. This has been demonstrated previously by the capacity of anti-I-A antibody treatment to abrogate T cell-mediated delayed-type hypersensitivity (DTH) responses to syngeneic tumor antigen, hapten, and non-H-2 histocompatibility antigens. Evidence obtained in these studies suggested that the primary action of antibody was related to its ability to interfere with macrophage-T cell interactions during antigen presentation, consistent with the demonstration that similar antibodies inhibit T cell binding to antigen-pulsed macrophages in vitro. Results presented in this report provide evidence for an additional consequence of in vivo antibody administration that may be secondary to any direct effects on I-A-restricted antigen presentation. Thus, animals treated with I-A subregion-specific antibodies also develop a population of antigen-specific suppressor T cells (Ts) capable of inhibiting recipient Ly-1+ T cell responses to tumor antigen. The induction of suppression appeared to be an essential component of the total biological activity of these antibodies, because elimination of Ts precursors by cyclophosphamide also abrogated the antibody-mediated inhibition of DTH responsiveness. These results are discussed with respect to the possible mechanisms of Ts activation by anti-I-A antibody administration, and the general applicability of this approach as a means of clinical immunotherapy to limit inappropriate T cell responses in human disease.
Mass Production of Conidia of Penicillium frequentans , a Biocontrol Agent Against Brown Rot of Stone Fruits

Conidial production of Penicillium frequentans , a biocontrol agent of the fungal pathogen Monilinia laxa , was tested in liquid and solid-state fermentation. Conidial production of P. frequentans in solid-state fermentation was higher than in liquid-state fermentation. Solidstate fermentation was made in specially designed plastic bags (VALMIC ® ) containing peat:vermiculite (1:1 w/w). Addition of nutrients to the peat:vermiculite increased conidial production of P. frequentans , especially when lentil meal was added. The number of conidia obtained in this solid-state fermentation was maintained in the range of 10 8 -10 9 conidia g -1 from 5 to 120 days after inoculation. Germinability of these conidia was > 90% until 90 days of incubation and declined at 120 days. Optimal initial moisture content in the substrate was 30-40% (v/w). At lower moisture contents, significant reductions in conidial production and germinability were observed, particularly at 10% (v/w). Conidial production was similar when the substrate was inoculated with 10 5 , 10 6 or 10 7 conidia g -1 dry substrate. Fresh conidia produced by solid-state fermentation reduced the incidence of brown rot on plums by 75%.