A single species of plant predicts territory occupancy in a population of Peruvian Plantcutters

2020 ◽  
Vol 91 (4) ◽  
pp. 331-345
Author(s):  
Sergio Nolazco ◽  
Amalia M. Sánchez
Keyword(s):  
Single Species ◽  
Territory Occupancy

In vitro assembly of 2-D crystals from partially purified EA1 protein secreted by Bacillus anthracis strain Delta Sterne-1

1994 ◽  
Vol 52 ◽  
pp. 276-277
Author(s):  
Mary Beth Downs ◽  
Wilson Ribot ◽  
Joseph W. Farchaus
Keyword(s):  
Cell Wall ◽  
Molecular Sieves ◽  
Cell Envelope ◽  
Single Species ◽  
Supporting Cell ◽  
Surface Layers ◽  
Rabbit Igg ◽  
In Vitro Assembly ◽  
Covalently Linked

Many bacteria possess surface layers (S-layers) that consist of a two-dimensional protein lattice external to the cell envelope. These S-layer arrays are usually composed of a single species of protein or glycoprotein and are not covalently linked to the underlying cell wall. When removed from the cell, S-layer proteins often reassemble into a lattice identical to that found on the cell, even without supporting cell wall fragments. S-layers exist at the interface between the cell and its environment and probably serve as molecular sieves that exclude destructive macromolecules while allowing passage of small nutrients and secreted proteins. Some S-layers are refractory to ingestion by macrophages and, generally, bacteria are more virulent when S-layers are present.When grown in rich medium under aerobic conditions, B. anthracis strain Delta Sterne-1 secretes large amounts of a proteinaceous extractable antigen 1 (EA1) into the growth medium. Immunocytochemistry with rabbit polyclonal anti-EAl antibody made against the secreted protein and gold-conjugated goat anti-rabbit IgG showed that EAI was localized at the cell surface (fig 1), which suggests its role as an S-layer protein.

Relationship between total plasma homocysteine and the risk of aneurysms – a meta-analysis

VASA ◽  
2020 ◽  
pp. 1-6
Author(s):  
Hanji Zhang ◽  
Dexin Yin ◽  
Yue Zhao ◽  
Yezhou Li ◽  
Dejiang Yao ◽  
...  
Keyword(s):  
Large Scale ◽  
Meta Analysis ◽  
Single Species ◽  
Total Plasma ◽  
Control Groups ◽  
Randomized Controlled ◽  
Randomized Controlled Studies ◽  
The Difference ◽  
The Relationship ◽  
Healthy Participants

Summary: Our meta-analysis focused on the relationship between homocysteine (Hcy) level and the incidence of aneurysms and looked at the relationship between smoking, hypertension and aneurysms. A systematic literature search of Pubmed, Web of Science, and Embase databases (up to March 31, 2020) resulted in the identification of 19 studies, including 2,629 aneurysm patients and 6,497 healthy participants. Combined analysis of the included studies showed that number of smoking, hypertension and hyperhomocysteinemia (HHcy) in aneurysm patients was higher than that in the control groups, and the total plasma Hcy level in aneurysm patients was also higher. These findings suggest that smoking, hypertension and HHcy may be risk factors for the development and progression of aneurysms. Although the heterogeneity of meta-analysis was significant, it was found that the heterogeneity might come from the difference between race and disease species through subgroup analysis. Large-scale randomized controlled studies of single species and single disease species are needed in the future to supplement the accuracy of the results.

A STUDY ON ICHTHYO-DIVERSITY OF MUNTJIBPUR POND OF ALLAHABAD (U.P.) INDIA

2017 ◽  
Vol 23 (1) ◽  
Author(s):  
ASHOK KUMAR VERMA
Keyword(s):  
Single Species ◽  
Single Genus ◽  
One Year

An attempt was made to find the ichthyo-diversity of Muntjibpur pond of Allahabad. Systematic surveys were conducted during a period of one year. A total of 13 species of fishes belonging to 12 genera, 8 families and 5 orders were identified. Siluriformes order is represented by 5 genera and 5 species while Cypriniformes order by 4 genera and 5 species. Each of the orders Clupeiformes, Osteoglossiformes and Ophiocephaliformes is represented by single genus and single species.

Fine-scale taxonomic and temporal variability in the energy density of invertebrate prey of juvenile Chinook salmon Oncorhynchus tshawytscha

2020 ◽  
Vol 655 ◽  
pp. 185-198
Author(s):  
J Weil ◽  
WDP Duguid ◽  
F Juanes
Keyword(s):  
Energy Density ◽  
Chinook Salmon ◽  
Temporal Variability ◽  
Energy Content ◽  
Single Point ◽  
Single Species ◽  
Fine Scale ◽  
Temporal Differences ◽  
Juvenile Chinook Salmon ◽  
Juvenile Chinook

Variation in the energy content of prey can drive the diet choice, growth and ultimate survival of consumers. In Pacific salmon species, obtaining sufficient energy for rapid growth during early marine residence is hypothesized to reduce the risk of size-selective mortality. In order to determine the energetic benefit of feeding choices for individuals, accurate estimates of energy density (ED) across prey groups are required. Frequently, a single species is assumed to be representative of a larger taxonomic group or related species. Further, single-point estimates are often assumed to be representative of a group across seasons, despite temporal variability. To test the validity of these practices, we sampled zooplankton prey of juvenile Chinook salmon to investigate fine-scale taxonomic and temporal differences in ED. Using a recently developed model to estimate the ED of organisms using percent ash-free dry weight, we compared energy content of several groups that are typically grouped together in growth studies. Decapod megalopae were more energy rich than zoeae and showed family-level variability in ED. Amphipods showed significant species-level variability in ED. Temporal differences were observed, but patterns were not consistent among groups. Bioenergetic model simulations showed that growth rate of juvenile Chinook salmon was almost identical when prey ED values were calculated on a fine scale or on a taxon-averaged coarse scale. However, single-species representative calculations of prey ED yielded highly variable output in growth depending on the representative species used. These results suggest that the latter approach may yield significantly biased results.

POTENTIAL PRODUCTIVITY ADAPTIVE AGROPHUTOCENOZIS ON SLOPING LANDS OF THE STEPPE TRANS-URALS

2020 ◽  
Author(s):  
R.А. Idrisov ◽  
Keyword(s):  
Protein C ◽  
Nutritional Value ◽  
Energy Content ◽  
Single Species ◽  
Exchange Energy ◽  
Metabolic Energy ◽  
Potential Productivity ◽  
Maximum Productivity ◽  
Sloping Lands ◽  
Natural Herb

The correct construction of agrophytocenoses on the slopes of the steppe trans-Urals helped to create maximum productivity. In the arid climate, the most productive were the double mixtures of alfalfa with brittle sitnik, wheatgrass is syd, providing an average of 41.6 and 40.2 quintals per hectare (c/ha) of hay, 32.1 and 31.0 GJ/ha OE (exchange energy per hectare), 4.5 and 4.3 quintals per hectare of boiled protein (c/ha) over 5 years. Single-species steppe ecotypes, brittle sieve and wheatgrass sieve in productivity slightly gave way to double components, providing respectively hay- 32.2 and 37.2 cents per hectare, exchange energy 22.2 and 25.7 GJ/ha, digested protein 1.93 and 2.53 c/ha. The enrichment of agrophytocense by the legume component allowed to increase the metabolic energy content to the level of 32.1 and 31.0-GJ/ha, digested protein to 4.5 and 4.3 quintals per hectare, which is 14 times the nutritional value of the metabolic energy, the digested protein is 10 times higher than the natural herb.

BOTANICAL COMPOSITION AND PRODUCTIVITY OF PERENNIAL GRASSES AGROPHYTOCENOSES WITH TETRAPLOID MEADOW CLOVER

1970 ◽  
pp. 59-62
Author(s):  
N. I. Kasatkina ◽  
Zh. S. Nelyubina
Keyword(s):  
Dry Weight ◽  
Single Species ◽  
Lotus Corniculatus ◽  
Specific Weight ◽  
Biological Properties ◽  
Phleum Pratense ◽  
Perennial Grasses ◽  
High Yield ◽  
Botanical Composition ◽  
The Third

The biological properties of plants, their mutual relations under different growth conditions and at different periods of their life, must be known for obtaining highly productive agrophytocenoses with participation of a meadow clover (Trifolium pratense L.). Botanical composition and fodder productivity of perennial grasses in agrocenoses with participation of meadow tetraploid clover Kudesnik were studied in 2014-2017. It was revealed that in the first and second years of use the agrophytocenosis, the yield of green mass was formed due to meadow tetraploid clover, the share of its participation in the first mowing was at level of 71-87% and 64-97% respectively. Specific weight of clover in multispecies agrocenoses considerably decreased by the third year of use: in the first mowing up to 32-68%, in the second - up to 8-52%. At the same time, the percentage of long-term herbaceous grasses increased: meadow timothy (Phleum pratense L.) - up to 34-54%, eastern galega (Galéga orientális Lam.) - up to 33%, changeable alfalfa (Medicago x varia Martyn) - up to 22-54%, lotus corniculatus (Lotus corniculatus L.) - up to 14-19%. The proportion of weed admixture in single-species clover planting was 12%, in agrocenoses - 2-14%. The grass mixtures clover + timothy and clover + alfalfa + timothy were less infested by weeds. High yield of dry weight of single-species sowing of meadow tetraploid clover was obtained in the first two years of use - 7.8 and 6.5 tons / ha, respectively. By the third year of use, the productivity of clover has decreased to 2.9 t / ha. On average, for three years of use, the highest yield (6.2-6.3 t / ha) was formed by agrocenoses meadow tetraploid clover + meadow timothy and meadow tetraploid clover + changeable alfalfa + meadow timothy.

Syntaxonomic changes in the plant cover of meadow steppe in the «Mikhailovskaya Tselina» reserve (Sumy Region, Ukraine)

2006 ◽  
pp. 43-57 ◽  
Author(s):  
H. N. Lysenko ◽  
I. A. Korotchenko
Keyword(s):  
Nature Reserve ◽  
Plant Cover ◽  
Ecological Factors ◽  
Single Species ◽  
Meadow Steppe ◽  
Total Species

Changes in the set of syntaxa have been traced for the plant cover of the «Mikhaylovskaya Tselina» meadow-steppe (an isolated part of the Ukrainian Steppe Nature Reserve, Sumy Region, Ukraine) with the help of the Braun-Blanquet approach. The area vegetation syntaxa prodromus includes 2 classes, 2 rders, 3 alliances, 9 associations, and 6 subasso­ciations, 2 of the latter described anew. The plant cover is highly dynamic and undergoes expressed meso­phytization, especially within the area where strict protection has been maintained since 1961. Amplitudes of the principal ecological factors and also peculiarities of their shift under exogenic regulation are determined with the help of the method of synecological phyto­indication (i. e. not single species but total species sets of communities serve as indicators). The essential transformations of the reserve meadow steppes are probably caused by the «insular» character of the reserve, its small size, also by the poorness of the set of natural grazers and hence the inadequacy of regulation by means of mowing.

Use of Biomonitoring to Control Toxics in the United States

1988 ◽  
Vol 20 (10) ◽  
pp. 101-108 ◽  
Author(s):  
Nelson A. Thomas
Keyword(s):  
Water Quality ◽  
Chronic Toxicity ◽  
National Policy ◽  
Single Species ◽  
Field Studies ◽  
The United States ◽  
Toxicity Tests ◽  
Toxic Pollutants ◽  
Receiving Waters ◽  
Biological Field

A biomonitoring program has been developed in support of the National Policy for the Development of Water Quality-Based Permit Limitations for Toxic Pollutants. The program focuses on the use of laboratory toxicity tests on aquatic plants and animals to predict ecosystem impact caused by toxic pollutants. Both acute and chronic toxicity tests were developed to test effluents and ambient waters. Laboratory and biological field studies were conducted at nine sites. Single species laboratory toxicity tests were found to be good predictors of impacts on the ecosystem when two or more species were used. Biomonitoring can be undertaken either on effluents and/or on the receiving waters. In that toxicity related to seeps, leachates and storm sewers has often been found upstream from dischargers, it is beneficial to conduct both effluent and ambient biomonitoring.

Regeneration dynamics in an alluvial dense ash (Fraxinus excelsior L.) stand

2001 ◽  
Vol 66 ◽  
Author(s):  
M. Tabari ◽  
N. Lust ◽  
L. Nachtergale
Keyword(s):  
Alluvial Soil ◽  
Single Species ◽  
Fraxinus Excelsior ◽  
Growth Stages ◽  
Acer Pseudoplatanus ◽  
Development Stages ◽  
Regeneration Dynamics ◽  
Broadleaved Tree Species ◽  
Succession Process ◽  
Broadleaved Tree

Broadleaves  regeneration dynamics and the succession mechanism were studied within  a    transect of 14 m x 56 m in a dense 80-year-old ash stand situated on an  alluvial soil. For this    purpose, abundance and height of all naturally regenerated species at  different development    stages were analyzed and their distribution over the juvenile and older  growth stages    determined.    The study reveals that from the main broadleaved tree species, Quercus robur and Fagus    sylvatica regeneration scarcely occur at any  growth stages. No Fraxinus excelsior regeneration,    except 1 unit, taller than sapling (1.5-4 m) can be found on this soil  type. On the contrary, Acer    pseudoplatanus represents different development  stages (seedling, sapling, thicket, small pole    and large pole) and in stand patches where an understorey is practically  lacking, its    regeneration is well developed. Results generally show that at the juvenile  and older growth    stages Acer proceeds Fraxinus and regeneration is largely  dominated by the invasive Acer. It is    expected that this succession process will continue and that Acer will overcome in the    overstorey and even gradually form an almost single-species dominating  stage. Direct    interventions are unavoidable in order to regulate the primary mixture  patterns.

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