Warm-blooded Organisms Research Articles

To What Extent Is Water Responsible for the Maintenance of the Life for Warm-Blooded Organisms?

In this work, attention is mainly focused on those properties of water which are essentially changed in the physiological temperature range of warm-blooded organisms. Studying in detail the half-width of the diffusion peak in the quasi-elastic incoherent neutron scattering, the behavior of the entropy and the kinematic shear viscosity, it is shown that the character of the translational and rotational thermal motions in water radically change near TH ~ 315 K, which can be interpreted as the temperature of the smeared dynamic phase transition. These results for bulk pure water are completed by the analysis of the isothermic compressibility and the NMR-spectra for water-glycerol solutions. It was noted that the non-monotone temperature dependence of the isothermic compressibility (βT) takes also place for the water-glycerol solutions until the concentration of glycerol does not exceed 30 mol%. At that, the minimum of βT shifts at left when the concentration increases. All these facts give us some reasons to assume that the properties of the intracellular and extracellular fluids are close to ones for pure water. Namely therefore, we suppose that the upper temperature limit for the life of warm-blooded organisms [TD = (315 ± 3) K] is tightly connected with the temperature of the dynamic phase transition in water. This supposition is equivalent to the assertion that the denaturation of proteins at T ≥ TH is mainly provoked by the rebuilding of the H-bond network in the intracellular and extracellular fluids, which takes place at T ≥ TH. A question why the heavy water cannot be a matrix for the intracellular and extracellular fluids is considered. The lower physiological pH limit for the life of warm-blooded organisms is discussed.

Fecundity selection predicts Bergmann's rule in syngnathid fishes

The study of latitudinal increases in organismal body size (Bergmann's rule) predates even Darwin's evolutionary theory. While research has long concentrated on identifying general evolutionary explanations for this phenomenon, recent work suggests that different factors operating on local evolutionary timescales may be the cause of this widespread trend. Bergmann's rule explains body size variation in a diversity of warm-blooded organisms and there is increasing evidence that Bergmann's rule is also widespread in ectotherms. Bergmann's rule acts differentially in species of the Syngnathidae, a family of teleost fishes noted for extreme adaptations for male parental care. While variation in body size of polygamous Syngnathus pipefish is consistent with Bergmann's rule, body size is uncorrelated with latitude in monogamous Hippocampus seahorses. A study of populations of Syngnathus leptorhynchus along a natural latitudinal and thermal gradient indicates that increases in body size with latitude maintain the potential reproductive rate of males despite significant decreases in ambient temperatures. Polygyny is necessary in order to maximize male reproductive success in S. leptorhynchus, suggesting a possible a link between fecundity selection and Bergmann's rule in this species.

Biological and physicochemical properties of Yersinia pseudotuberculosis cultures carrying the Yersinia pestis fra operon

The biological and physicochemical properties of cultures of two isogenic recombinant variants of Y. pseudotuberculosis were studied. The cell genomes of the studied cultures differed only with respect to the presence or absence of the fra operon responsible for capsule formation in Y. pestis. The expression of the above-mentioned trait is amplified by an increase in the cultivation temperature of microbial biomass and stimulates a decrease in the viability and adaptation potential of bacteria in vitro. In a warm-blooded host organism, the capsule-forming recombinant variant is characterized by greater residual pathogenicity and immunogenicity to the experimental plague strains of laboratory animals as compared to the reference variant cells. These differences can be attributed to the more increased colonizing ability of the capsule-forming microbes caused by the resistance of the host cells to phagocytosis.

Thermodynamics of Adsorption of Imidacloprid at Constant Charge Hydrophobic Surfaces: Physicochemical Aspects of Bioenvironmental Activity

Adsorption of the insecticide 1-(6-chloro-3-pyridylmethyl)-N-nitroimidazolidin-2-ylideneamine (Imidacloprid) on the hanging mercury drop electrode (HMDE) surface was studied by temperature-dependent stripping voltammetry (TD-SV). At near physiological pH, under reducing conditions, the Gibbs free energy of adsorption, DeltaGADS, shows two distinct temperature-dependent regimes. (a) At 0 degrees < T < 10 degrees C a temperature-independent mechanism occurs with a constant DeltaGADS = -40.5 kJ/mol, resulting in strong chemisorption at high surface coverage. For T < 10 degrees C a considerable enthalpy gain is estimated, and this represents the driving force for the adsorption of Imidacloprid onto the electrode surface. (b) At T > 10 degrees C a temperature-dependent mechanism is operative with DeltaGADS/DeltaT = -91.4 J/K mol, resulting in a rapid weakening of adsorption and low surface coverage. On the basis of the present findings we suggest that the strong chemisorption at T < 10 degrees C at physiological pH under reducing conditions is related to the high specific insecticide activity of Imidacloprid in cool-blooded insects as contrasted to its low efficiency in warm-blooded organisms.

The role of the H-bond network in the creation of the life-giving properties of water

This work is devoted to the study of the properties of water in the physiological temperature range for warm-blooded organisms. Special attention is paid to the nature of thermal motion in bulk water. Through the analysis of data from incoherent neutron scattering in water, it is shown that the crystal-like thermal motion in water takes place only in its supercooled and normal states, the temperature of which does not exceed T H = (310 ± 5) K. A quite similar temperature, T ν = (308 ± 5) K, is also characteristic of the temperature dependence of the kinematic shear viscosity of water. It is shown that the average number of H-bonds per molecule near T H is about 2.1–2.3 because the spatially ordered H-bond network in bulk water becomes unstable. The interpretation of T H as the temperature of the dynamic phase transition from the crystal-like to argon-like character of thermal motion is discussed in detail. It is assumed that the nature of thermal motion in the “cellular water solution” changes analogously at temperatures close to T H. As a result, the problem of protein and DNA denaturation and the death of living organisms is connected with the dynamic phase transition in intracellular water.

The power of size: A meta-analysis reveals consistency of allometric regressions

The recent revival of body size relationships in ecology has boosted our understanding of ecosystems. Here, a simple model, based on energy equivalency, integrates rate, age, density and area parameters that are important in ecological modelling. Allometric relationships for quantities as diverse as ingestion, mortality, age at maturity, maximum density, territory size of different species groups and trophic levels are derived from production and some ecological transfer efficiencies. The theory is supported by a meta-analysis of 230 allometric regressions derived from over 100 publications. The relationships are shown to be mutually consistent and fit into the model. Rate constants generally decrease with organism mass at an exponent of −1/4. Age and density parameters increase in the same direction following a slope of 1/4. Differences between plants, invertebrates, cold-blooded vertebrates and warm-blooded vertebrates are reflected in the intercepts and can be anticipated from temperature, trophic position and evolutionary history. Cold-blooded species have lower rate constants but reach higher ages and densities than equally sized warm-blooded organisms. Intercepts of body size distributions tend to decrease with trophic position, at a level that is predicted by ecological efficiencies. Area parameters, such as the territory size and geographic range, tend to decrease with species size, but slopes and intercepts were often different from the expected value. Occasionally, outliers were also noted for rate, time or density parameters. With the model at hand, such deviations can be easily identified and subjected to more extensive empirical and theoretical research. With these restrictions, specific issues can now be addressed by a framework that complies with extensive information on related parameters.

Isochores Exhibit Evidence of Genes Interacting With the Large-Scale Genomic Environment

The genomes of mammals and birds can be partitioned into megabase-long regions, termed isochores, with consistently high, or low, average C + G content. Isochores with high CG contain a mixture of CG-rich and AT-rich genes, while high-AT isochores contain predominantly AT-rich genes. The two gene populations in the high-CG isochores are functionally distinguishable by statistical analysis of their gene ontology categories. However, the aggregate of the two populations in CG isochores is not statistically distinct from AT-rich genes in AT isochores. Genes tend to be located at local extrema of composition within the isochores, indicating that the CG-enriching mechanism acted differently when near to genes. On the other hand, maximum-likelihood reconstruction of molecular phylogenetic trees shows that branch lengths (evolutionary distances) for third codon positions in CG-rich genes are not substantially larger than those for AT-rich genes. In the context of neutral mutation theory this argues against any strong positive selection. Disparate features of isochores might be explained by a model in which about half of all genes functionally require AT richness, while, in warm-blooded organisms, about half the genome (in large coherent blocks) acquired a strong bias for mutations to CG. Using mutations in CG-rich genes as convenient indicators, we show that approximately 20% of amino acids in proteins are broadly substitutable, without regard to chemical similarity.

Antifungal effect of Australian tea tree oil on Malassezia pachydermatis isolated from canines suffering from cutaneous skin disease.

The lipophilic yeast Malassezia pachydermatis is part of the normal skin flora of most warm-blooded organisms. In a number of surveys it could be demonstrated that this yeast species might be involved in different skin diseases like seborrhoeic dermatitis, especially in dogs and cats. In order to look for an alternative therapeutic agent to the commonly used antimycotic and antiseptic synthetic substances the in vitro activity of Australian tea tree oil, the essential oil of Melaleuca alternifolia, against several strains of Malassezia pachydermatis was examined. All tested strains showed remarkably high susceptibility to tea tree oil. With these results the excellent antibacterial activity of tea tree oil is extended to a new group of fungal pathogens colonizing mainly mammals' skin. During the last ten years there was an increasing popularity of tea tree oil containing human health care products. The presented data open up new horizons for this essential oil as a promising alternative agent for topical use in veterinary medicine as well.

Ingestion rate and body size in phagotrophic organisms

A general functional relationship between body weight (10−11 to 108 g) and ingestion rate has been found to exist throughout the protistan and metazoan kingdoms. Results, based on a mathematical interpretation of standardized, quantitative data, indicate that ingestion rate is a log–log linear function (i.e., power function) of body weight (I = a W0.829 for cold-blooded forms and I = a W0.778 for warm-blooded forms, where I = ingestion rate and W = body weight). The slopes of the cold-blooded and warm-blooded regression lines are not significantly different from each other (i.e., they are parallel). This allows one to use the difference between the respective curves to estimate the weight-specific cost of warm-bloodedness. Such an analysis of the data indicates that a warm-blooded organism must ingest about ten times more food per unit body weight than cold-blooded forms. This functional relationship may be a manifestation of the physiological constraints placed on organisms by surface area to volume ratio phenomena, related to absorptive surfaces, mouth areas, and body volumes. The present analysis suggests that flexibility in functional design is limited by physical phenomena which affect phenotypic plasticity.

Larvicidal Efficiency of Some Inorganic Compounds and Plant Extracts against the House Fly

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Organ Function and Form Perception*

The Rorschach records of two groups, each consisting of 60 patients, were compared. One group, designated as V group, was picked for the common feature of arterial hypertension. The other group, designated as L group, was composed of 30 cases of chronic arthritis and 30 cases of parkinsonism. The two groups showed specific preferences for certain types of responses which made it possible to distinguish between an L type and a V type of response. The critical responses could be subsumed under 4 general categories. In all 120 patients the number of responses of their own type exceeded the number of responses of the other type in at least 2 categories. The 4 categories and the differences between the two groups are as follows: 1. Vertical axis— (a) Location—Patients of the L group had a much greater tendency to center one-half or more than one-half of their responses in the axis than the V group. (b) Form—Patients of the V group saw the axial part as an opening about 5 times more often than the L group. (c) Content—Warm-blooded organisms and dynamic emphasis centered in the axis were observed more often in the L group than in the V group. The V group saw more anatomical structures, ritualistic objects, and water and fire than the L group. 2. Kinesthetic responses—Goal-directed activities were indicated more often by the L patients, while actions determined by convention or by efforts to maintain a certain position were indicated more often by the V patients. 3. Integration and disintegration—The tendency toward integration of the inkblots into a comprehensive interpretation was more pronounced in the L group, while the tendency toward disintegration was more pronounced in the V group. 4. Animals—Eagles and pigs were most frequently seen by the L group, while cows, sheep and beasts of prey were most frequently seen in the V group. The psychological interpretation of the findings suggested that arthritic and parkinsonian patients are dominated by an urge for individualistic, independent action. Obstacles are liable to provoke aggressiveness in excess of the chances for success. Patients suffering from arterial hypertension have a tendency toward dependent relationships in form of identification with their social environment. Action is determined by material needs and by social standards. Obstacles easily provoke conflicts between dependent and aggressive impulses, resulting in restriction of the range of action and of perception. Specific correlations between organ dominance, disease liability and form of perception were discussed. They gave added insight into the physiological basis of the Rorschach method, and of physiognomical understanding. The discovery of two gestalt tendencies associated with individualistic and with collectivistic personality types suggested the possibility of making current personality and aptitude tests more reliable, and the possibility of further extending the use of the Rorschach method.