Species-specific responses of tree saplings to herbivory in contrasting light environments: An experimental approach

Ecoscience ◽  
2010 ◽  
Vol 17 (2) ◽  
pp. 156-165 ◽  
Author(s):  
Elena Baraza ◽  
Regino Zamora ◽  
José A. Hódar
Keyword(s):  
Experimental Approach ◽  
Species Specific

Development of a species-specific fractionation equation for Arctic charr (Salvelinus alpinus (L.)): an experimental approach

Hydrobiologia ◽  
2010 ◽  
Vol 650 (1) ◽  
pp. 67-77 ◽  
Author(s):  
Jane A. Godiksen ◽  
Martin-A. Svenning ◽  
J. Brian Dempson ◽  
Maare Marttila ◽  
Andrea Storm-Suke ◽  
...  
Keyword(s):  
Experimental Approach ◽  
Salvelinus Alpinus ◽  
Arctic Charr ◽  
Species Specific ◽  
Fractionation Equation

5-Methylcytosine-Rich Heterochromatin in Reptiles

2019 ◽  
Vol 157 (1-2) ◽  
pp. 53-64 ◽  
Author(s):  
Michael Schmid ◽  
Claus Steinlein ◽  
Alina M. Reiter ◽  
Michail Rovatsos ◽  
Marie Altmanová ◽  
...  
Keyword(s):  
Indirect Immunofluorescence ◽  
Sex Chromosomes ◽  
Dna Sequences ◽  
Experimental Approach ◽  
Constitutive Heterochromatin ◽  
Banding Patterns ◽  
Turtle Species ◽  
C Banding ◽  
Species Specific ◽  
Chromosome Regions

An experimental approach using monoclonal anti-5-methylcytosine antibodies and indirect immunofluorescence was elaborated for detecting 5-methylcytosine-rich chromosome regions in reptilian chromosomes. This technique was applied to conventionally prepared mitotic metaphases of 2 turtle species and 12 squamate species from 8 families. The hypermethylation patterns were compared with C-banding patterns obtained by conventional banding techniques. The hypermethylated DNA sequences are species-specific and are located in constitutive heterochromatin. They are highly reproducible and often found in centromeric, pericentromeric, and interstitial positions of the chromosomes. Heterochromatic regions in differentiated sex chromosomes are particularly hypermethylated.

scholarly journals Segregation into separate rouleaux of erythrocytes from different species. Evidence against the agglomerin hypothesis of rouleaux formation

1983 ◽  
Vol 214 (1) ◽  
pp. 257-260 ◽  
Author(s):  
D R Forsdyke ◽  
P M Ford
Keyword(s):  
Fluorescence Microscopy ◽  
Specific Surface ◽  
Experimental Approach ◽  
Fluorescein Isothiocyanate ◽  
Additional Species ◽  
Rouleau Formation ◽  
Species Specific ◽  
Rouleaux Formation

Erythrocytes from one species were labelled with fluorescein isothiocyanate and mixed with unlabelled erythrocytes from another species. Albumin polymers were added to generate rouleaux. The species of origin of erythrocytes in rouleaux was determined by fluorescence microscopy. Erythrocytes from different species segregated into independent rouleaux. However, fluorescent and non-fluorescent erythrocytes from one individual were mixed randomly in rouleaux. These results confirm, using a novel experimental approach, previous observations of Sewchand & Canham [(1976) Can. J. Physiol. Pharmacol. 54, 437-442]. Since rouleaugenic agents are not species-specific, under the ‘agglomerin’ hypothesis of rouleau formation they would be expected to form bridges between cells from different species. It follows that either the agglomerin hypothesis is incorrect, or additional species-specific surface components are involved in the aggregation of agglomerin-cross-bridged cells.

scholarly journals Molecular basis for the evolution of species-specific hemoglobin capture by pathogenic Staphylococcus

2018 ◽  
Author(s):  
Jacob E. Choby ◽  
Hanna B. Buechi ◽  
Allison J. Farrand ◽  
Eric P. Skaar ◽  
Matthew F. Barber
Keyword(s):  
Molecular Basis ◽  
Pathogenic Bacteria ◽  
Experimental Approach ◽  
Invasive Disease ◽  
Globin Genes ◽  
Host Proteins ◽  
Adaptive Mutations ◽  
Species Specific ◽  
Binding Interfaces ◽  
Hemoglobin Evolution

ABSTRACTMetals are a limiting resource for pathogenic bacteria and must be scavenged from host proteins. Hemoglobin provides the most abundant source of iron in the human body and is required by several pathogens to cause invasive disease. However, the consequences of hemoglobin evolution for bacterial nutrient acquisition remain unclear. Here we show that the α- and β-globin genes exhibit strikingly parallel signatures of adaptive evolution across simian primates. Rapidly evolving sites in hemoglobin correspond to binding interfaces of IsdB, a bacterial hemoglobin receptor encoded by pathogenic Staphylococcus aureus. Using an evolution-guided experimental approach, we demonstrate that divergence between primates and staphylococcal isolates governs hemoglobin recognition and bacterial growth. Reintroducing putative adaptive mutations in α- or β-globin proteins is sufficient to impair S. aureus binding, providing a mechanism for the evolution of disease resistance. These findings suggest that bacterial hemoprotein capture has driven repeated evolutionary conflicts with hemoglobin during primate descent.

Experimental Determination of the Effective Resolution Limit in Thick Specimens at High Voltages

1975 ◽  
Vol 33 ◽  
pp. 664-665
Author(s):  
Mircea Fotino
Keyword(s):  
Experimental Approach ◽  
Chromatic Aberration ◽  
Resolving Power ◽  
Biological Research ◽  
Specimen Thickness ◽  
Resolution Limit ◽  
High Voltage Electron Microscopy ◽  
Voltage Electron ◽  
Resolution Level

The use of thick specimens (0.5 μm to 5.0 μm or more) is one of the most resourceful applications of high-voltage electron microscopy in biological research. However, the energy loss experienced by the electron beam in the specimen results in chromatic aberration and thus in a deterioration of the effective resolving power. This sets a limit to the maximum usable specimen thickness when investigating structures requiring a certain resolution level.An experimental approach is here described in which the deterioration of the resolving power as a function of specimen thickness is determined. In a manner similar to the Rayleigh criterion in which two image points are considered resolved at the resolution limit when their profiles overlap such that the minimum of one coincides with the maximum of the other, the resolution attainable in thick sections can be measured by the distance from minimum to maximum (or, equivalently, from 10% to 90% maximum) of the broadened profile of a well-defined step-like object placed on the specimen.

Electron Microscopy in the Study of Natural Phytoplankton Assemblages

1985 ◽  
Vol 43 ◽  
pp. 620-623
Author(s):  
Linda Sicko-Goad
Keyword(s):  
Electron Microscopy ◽  
Aquatic Environment ◽  
Size Range ◽  
Physical Parameters ◽  
Specific Information ◽  
Phytoplankton Assemblages ◽  
Phytoplankton Productivity ◽  
Ecosystem Effects ◽  
Time Of Year ◽  
Species Specific

Although the use of electron microscopy and its varied methodologies is not usually associated with ecological studies, the types of species specific information that can be generated by these techniques are often quite useful in predicting long-term ecosystem effects. The utility of these techniques is especially apparent when one considers both the size range of particles found in the aquatic environment and the complexity of the phytoplankton assemblages.The size range and character of organisms found in the aquatic environment are dependent upon a variety of physical parameters that include sampling depth, location, and time of year. In the winter months, all the Laurentian Great Lakes are uniformly mixed and homothermous in the range of 1.1 to 1.7°C. During this time phytoplankton productivity is quite low.

64: Rapid, Species-Specific Detection of Uropathogens from Clinical Urine Specimens Using an Electrochemical Microsensor Array

2005 ◽  
Vol 173 (4S) ◽  
pp. 18-18
Author(s):  
Joseph C. Liao ◽  
Mitra Mastali ◽  
David A. Haake ◽  
Bernard M. Churchill
Keyword(s):  
Specific Detection ◽  
Species Specific ◽  
Urine Specimens

Malfunctional Reorganization in the Developing Limbo-Prefrontal System in Animals: Implications for Human Psychoses?

2001 ◽  
Vol 12 (1) ◽  
pp. 8-14
Author(s):  
Gertraud Teuchert-Noodt ◽  
Ralf R. Dawirs
Keyword(s):  
Prefrontal Cortex ◽  
Mental Disorders ◽  
Dentate Gyrus ◽  
Cognitive Functions ◽  
Experimental Approach ◽  
Regulatory Mechanisms ◽  
Hippocampal Dentate Gyrus ◽  
Non Invasive ◽  
Invasive Method ◽  
Activity Dependent

Abstract: Neuroplasticity research in connection with mental disorders has recently bridged the gap between basic neurobiology and applied neuropsychology. A non-invasive method in the gerbil (Meriones unguiculus) - the restricted versus enriched breading and the systemically applied single methamphetamine dose - offers an experimental approach to investigate psychoses. Acts of intervening affirm an activity dependent malfunctional reorganization in the prefrontal cortex and in the hippocampal dentate gyrus and reveal the dopamine position as being critical for the disruption of interactions between the areas concerned. From the extent of plasticity effects the probability and risk of psycho-cognitive development may be derived. Advance may be expected from insights into regulatory mechanisms of neurogenesis in the hippocampal dentate gyrus which is obviously to meet the necessary requirements to promote psycho-cognitive functions/malfunctions via the limbo-prefrontal circuit.

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