Can Shrews Avoid Competition When Hutchinson's Ecological Rule Is Disobeyed?

It is established that Hutchinson's ratio of the weights and sizes of the body and foraging organs in similar species is not fully obeyed in shrew species of the genus Sorex. Similarity in the centroid size of the mandible was observed in the large species S. isodon and S. araneus. Differences in the shape of the mandible, which is intensely used in foraging, were detected between the species by geometric morphometrics. Interspecific differences were found in mandibular indices, which reflect trophic specialization and functional features of the mandibles. Shrews can therefore avoid competition even when Hutchinson's rule is violated. The avoidance is due to a transformation and specialization of the mandible and changes in prey capture methods and diet, rather than to changes in size. Hutchinson's ecological rule is thus not mandatory, but is only one of the conditions for reducing competition between closely related species.

Lifespans of Fur Color Morphs in Polymorphic Populations of the Mole Vole and the Hypothesis of Adaptive Polymorphism.

Different lifespans were for the first time demonstrated for three (brown, bicolor, and black) fur color morphs in ten mole vole populations of the Volga, Ural, and Trans-Ural regions. With the longest lifespan of 5 years in the species, morphs that numerically dominate in a population can live 1-4 years longer than accompanying morphs. Spearman's correlation coefficient between the longest lifespan of the morphs and their proportion in the population was Rsp = 0.81 (p < 0.0001). A number of morphological and functional features were identified in the color morphs. The findings are of general biological significance, confirming the hypothesis of adaptive polymorphism. Evolutionary and ecological mechanisms whereby selective advantages develop in morphs (as probable ecomorphs) are possible to evaluate using the morphs as a natural model of the initial step of sympatric form development in different parts of the range.

Analysis of Geographical Variability of Morphogenetic Trajectories Using the Mole Vole (Ellobius talpinus Pall.) as an Example.

ABSTTRACT: -Using the methods of geometric morphometrics, we have revealed the phenomenon of geographical variability of morphogenetic trajectories when doing side-by-side comparisons of mandibular shapes in individuals of different ages from three southern Trans-Ural populations of the mole vole (Ellobius talpinus Pall.) in the common morphospace.

Morphogenetic Effects of Resettlement of Mole Voles (Ellobius talpinus Pall., 1770) from the Southern Population to the Northern Boundary of the Species Range.

Geometric morphometry has been used to reveal transformations of mandible morphogenesis in the offspring of mole voles resettled to the northern part of the species range from a southern population. The transformations were new compared to both the original (southern) and the aboriginal (northern) populations. A significant increase in the intragroup morphological disparity estimated by the mean nearest neighbor distance (MNND) in the resettled animals compared to both aboriginal populations is an indirect indication of an increased developmental instability in the resettled animals exposed to new climatic conditions.

[Pathophysiological and clinical aspects of using L-arginine in cardiology and angiology]. / Patofiziologicheskie i klinicheskie aspekty primeneniia L-arginina v kardiologii i angiologii.

Presented herein is a review of scientific publications dedicated to studying the pharmacodynamics of L-arginine and possibilities of its clinical application. Interest to L-arginine is associated, first of all, with its role as a precursor in endogenous synthesis of nitric oxide (NO), playing an important role in regulation of the functional state of the vascular wall. According to numerous studies, oral and parenteral administration of L-arginine restores endothelial production of NO in such diseases as atherosclerosis, hypertension, type 2 diabetes mellitus, obliterating diseases of arteries of lower extremities. The NO-mediated effect of L-arginine manifests itself in increasing the capability of vessels to dilatation, decreasing blood platelet aggregation, and inhibiting proliferation of smooth muscle cells of vessels. The effect is most pronounced in patients presenting with hypercholesterolaemia and initially decreased reactivity of the blood channel. The mostly pronounced NO-mediated effect of L-arginine is observed in parenteral route of its administration. Prolonged administration of L-arginine slows down progression of atherosclerosis.

Morphological diversity of mole vole mono- and polymorphic populations: Does Chernov's "compensation principle" work within a population?

The ecological "compensation principle" enunciated by Yu.I. Chernov, who suggested a higher level of compensatory diversity in communities depleted in composition, proved to be also applicable to a single population, as demonstrated in a model rodent species, mole vole with mono- and polymorphic coat color, using the methods of geometric morphometrics. The mandible shape diversity was significantly increased in the monomorphic as compared to polymorphic populations, in which the division of foraging activities between animals of different morphs led to a suppression of general morphological diversity.

[INFLUENCE OF ANGIOPROTECTOR DRUGS ON THE EFFICACY OF CYTOSTATIC THERAPY (EXPERIMENTAL STUDY)].

The influence of angioprotector and endothelium-protector drugs pentoxifylline and unifuzol as components of supportive therapy on the efficacy of combined cytostatic treatment has been experimentally studied. It is established that pentoxifylline and unifuzol do not affect the antitumor and antimetastatic activity of doxorubicin and cyclophosphan with respect to Pliss lymphosarcoma and Walker 256 carcinosarcoma, and in some cases even potentiate the effect of cytostatic therapy.

P388 leukemia in CDF1 mice as the test system for studies of tumor-associated neoangiogenesis and hypercoagulation.

Blood levels of vascular endothelial growth factor, the main marker of angiogenesis activity, and coagulation hemostasis were studied in CDF1 mice with transplanted P-388 lymphocytic leukemia. Blood levels of vascular endothelial growth factor increased by 168% in mice with tumors. The animals developed the hypercoagulation syndrome manifesting in shorter activated partial thromboplastin time and prothrombin time and development of hyperfibrinogenemia.

[HER2-positive breast cancer: standard and double targeted therapy].

Neoadjuvant systemic therapy is frequently used option for the systemic treatment for breast cancer. Inclusion in the regimen of targeted drugs as trastuzumab (Herceptin) and pertuzumab significantly improves outcomes in HER2-positive breast cancer patients. A certain part of HER2-positive patients can be cured by using only targeted drugs without chemotherapy.

[The role of nanotechnology in creating novel antitumor agents].

Nanobiotechnology, defined as an arm of a nano-system is a rapidly developing area of medicine. Nanomaterials ranging from 1 to 1000 nm in size offer unique advantages of interaction with biological systems on the molecular level. Nanobiotechnologies can be used in definition, diagnosis and treatment of cancer thus leading to the new development of a new discipline--nanooncology. The potential of nanoparticles to be used in in-vivo tumor visualization, biomolecular profiling of tumor growth factors and targeted drug delivery is being studied. These methods stemming from nanotechnology may soon find a broad application in oncology.

[Phenogenetic variability and population meronomy].

In accordance with M.A. Shishkin's epigenetic evolutionary theory and S.V. Meyen's concept of meron, N.P. Krenke's "phenogenetic variability" can be considered as a realization of developmentally determined laws of possible transformations of particular characters (morphogenetic realization of meron). It includes two components: deterministic (organizing) one and stochastic (random) one. Organizing includes (epigenetic variability) represents a canalized component of morphogenesis determined by creode structure and arrangement of epigenetic thresholds, which alows to speak about morphogenetic rule of meronomic transformations. Random (realized) variability corresponds with stochastic component of morphogenesis, which makes it possible a spontaneous shifting of available developmental programs and selection of alternative subcreodes. Concepts of "population epigenetic landscape", "population ontogenesis" and "population meronomy" are introduced. Population ontogenesis (PO) can be considered as a peculiar deformation of species developmental program common to all individuals in particular population. This deformation is historically adjusted to concrete environmental conditions by natural selection. PO reflects general set of potential developmental patterns in concrete population, and it should be peculiar and unique one in respect to the whole species. It may be assumed that each individual contains information about invariant population epigenetic landscape (PEL), and thereby discrete individual phenotypes represent a probabilistic copy of general population epigenetic pattern. Analysis of bilateral structures among members of the same generation permits to visualize the principal pattern of PEL. Epigenetic thresholds and constructional bans constrain probable morphogenetic transformations and creates PEL, which is a general rule-cliché that formats total disparity of character states and theirs stochastic manifestation in taxonomic units, populations and individuals. Based on Waddington's ideas of creode, S.V. Meyen introduced concepts of intracreode and extracreode. Population meronomy allows to characterize peculiarities of extracreode of a population or a taxonomic unit while studying intracreodes as intraindividual variability by means of phenetical analysis (reductional stage) and phenogenetic synthesis (compositional stage). In this case we estimate not individual variability (plasticity) proper but generalized population or taxonomic epigenetic diversity of intracreode, which in actually becomes an extracreode. Population-meronomic analysis of bilateral compositions of antimere structure elements allows to construct a natural system of structure transformations and thereby to visualize meronomic diversity and transformation paths of meron.

[The characteristics of the latent periods of movements in cats during the differentiation of tonal and amplitude-modulated signals with changes in the modulation from high frequencies to low]. / Kharakteristika latentnykh periodov dvizhenii u koshek v protsesse differentsirovaniia tonal'nogo i amplitudno-modulirovannykh signalov pri izmenenii moduliatsii ot vysokikh chastot k nizkim.

The latent periods of the forepaw movements of cats were studied in the course of differentiation task performance. Pure tones and amplitude-modulated stimuli had to be differentiated. It was found out that the mean latency of motor responses to pure tones was significantly higher than that of responses to modulated signals. The latencies to the applied stimuli did not differ in the simple task (without differentiation). The latencies were influenced not only by the absolute values of modulation frequency but also by the frequency shift in successive experiments. Lowering modulation frequency decreased the latency. This effect was especially expressed around the values of 205-207 and 33-34 Hz.

[Characteristics of borderline modulation frequencies in the differentiation of tonal and amplitude-modulated stimuli following the removal of the inferior colliculus in rats]. / Kharakteristika granichnykh chastot moduliatsii pri differentsirovanii tonal'nogo i amplitudno-modulirovannykh stimulov posle udaleniia zadnego dvukholmiia u krys.

Elaboration of differentiation between sound stimuli was carried out in 15 laboratory rats. After bilateral ablations of auditory inferior colliculi the border frequency of stimulus amplitude modulation was determined for all rats when they still could differentiate between tonal and amplitude-modulated stimuli. Decrease in frequency of modulation by 2 Hz and more from the border frequency caused a complete loss of ability to differentiate. In all rats bilateral inferior colliculi ablations completely disturbed differentiation between tonal and amplitude-modulated signals with modulation frequency below 183-191 Hz (the range of border frequencies). The surgery however did not affect differentiation between tonal and amplitude-modulated signals with the modulation frequencies above 183-191 Hz. The data suggest that the functions of completion of coding of amplitude-modulated stimuli in the auditory system is strictly linked with definite structures.

[Comparison of the stability of morphometric and nonmetric skeletal characteristics of inbred mice with regard to environmental exposure in prenatal development]. / Sravnenie ustoichivosti morfometricheskikh i nemetricheskikh kharakteristik skeleta lineinykh myshei k sredovym vozdeistviiam v prenatal'nom razvitii.

The influence of some environmental factors on size and shape of mandible in BALB/cJLacSto inbred mice was studied during prenatal development by multivariate morphometric methods. The factors under study were: introduction of methylthiouracil into the diet of pregnant females; injections of pregnant females with adrenocorticotropic or parathyroid hormones; keeping the females at low temperatures (two regimes). It was established that the changes of mandible shape caused by the changes of conditions of prenatal development did not achieve the level of differences between strains, and mouse strain identification was possible under various conditions of animal's keeping. It has been shown by comparison of these results with preceding data that the nonmetric skeletal traits were more stable to the influence of the same factors than morphometric ones. This gives us the foundations to consider the method of evaluation of phenetic distances between natural groups of animals for the set of non-metric threshold skeletal traits more suitable for detection of genetical differentiation of wild populations.

[Paradoxical phenomenon of an increase in smooth muscle tonus of the cardiac arteries as affected by the combined action of vasoconstrictors]. / Paradoksal'nyi fenomen povysheniia tonusa gladkikh myshts arteri i serdtsa pri kombinirovannom deistvii vazokonstriktorov.

Removal of any component out of a set of biologically active substances augmented the coronary arteries smooth muscle tone. The phenomenon is discussed in respect to participation of intracellular regulatory mechanisms.

[Role of the geniculate body in performing conditioned reflexes to amplitude-modulated stimuli in the rat]. / Rol' medial'nogo kolenchatogo tela v realizatsii uslovnykh refleksov na amplitudno-modulirovannye stimuly u krys.

In 13 laboratory rats with bilateral auditory cortex ablation, the border frequency of amplitude-modulation still allowing differentiation between tonal and amplitude-modulated stimuli, did not change after bilateral section of the brachii of the posterior colliculi. Bilateral auditory cortex ablation and section of the brachii drastically disturbed this differentiation when the modulation frequencies were higher than 27-31 Hz. The data suggest that the completion of coding of amplitude-modulated stimuli does not take place at the level of the medial geniculate body, and that border frequencies defined after auditory cortex ablation are linked with the frontier posterior colliculi--thalamo-cortical system.

[Characteristics of the areas of synchronization of the neuronal responses of the inferior colliculi in greater horseshoe bats to the presentation of amplitude-modulated stimuli]. / Kharakteristika oblastei sinkhronizatsii otvetov neironov zadnikh kholmov podkovosnykh letuchikh myshei na pred''iavlenie amplitudno-modulirovannykh stimulov.

Response areas of synchronized discharges measured at different values of modulation rates were studied in inferior colliculus of bats (Rhinolophus ferrumequinum). Single neurons showed a variety of synchronized response areas to sinusoidally amplitude-modulated stimuli (thresholds of synchronized discharge plotted versus modulation rates, carrier frequency and modulation depth are constant). All neurons showed best modulation frequency where minimal thresholds could be obtained. Synchronized response areas measured in collicular units were sharply or widely tuned, some showed upper thresholds, tuning curves were symmetrical or asymmetrical. The data suggest that response features of studied units prove to be well suited for processing echoes produced by wing beats of flying insects.