THE STUDY OF HOMOGENEOUS AND HETEROGENEOUS SENSITIZED CRYSTALS OF CADMIUM SULFIDE. PART IV. FEATURES OF THE REVERSE PHOTOEXCITATION METHOD

For the first time, a reverse method of studying the spectral distribution curves of the photocurrent was applied, which allows to separate the contribution of equilibrium and non-equilibrium carriers. This publication is a continuation of the reviews [1-3]. In order to preserve the generality of the work, the numbering of sections is selected to be general. Numbers of formulas and figures are presented in sections. References to literature in each review are given individually. Cadmium sulfide crystals are used in our research as a convenient model material. The results obtained on them and the constructed models are also applied to other semiconductor substances.

K-means clustering of zebrafish embryos images acquired with AOTF-based hyperspectral microscope

Model organism studies are widely implemented in biomedical research fields. Zebrafish is a common and convenient model organism. To provide in vivo investigation of living zebrafish the non-invasive imaging methods are implemented. Hyperspectral imaging utilizing acousto-optic tunable filters is a perspective modality for zebrafish embryos and larvae automated observation. In this paper, the hyperspectral microscope based on the acousto-optical tunable filter is described. Using the hyperspectral image arrays obtained with the described setup, the K-means clustering algorithm is tested. The results obtained for different number of clusters are presented and discussed.

Optical Sensitivity of Camera-Like Eyes to White Light

Gastropod mollusks are convenient model organisms for studying the functioning of the visual system. The purpose of this work is to estimate the value of the optical sensitivity to white light for the camera-like eyes of gastropod mollusks and humans and analyze its effect on the spatial resolving power in two regions of the retina: in the center—for single photoreceptors of the first/second type in a mollusk and single cones in humans—and in the periphery—for single photoreceptors of the first/second type in a mollusk, as well as for single rods/cones and their groups, subject to spatial summation in humans. The methods of histology, light and transmission electron microscopy, morphometry, calculations and methods of statistical analysis are used in the work. In a mollusk, with a fixed pupil area, the value of the optical sensitivity of the eye to white light in the center of the retina for single photoreceptors of the first/second type is 0.5/0.006 μm2·sr and in the periphery of the retina, 0.9/0.009 μm2·sr. In humans, at the minimum and maximum pupil area, respectively, the value of the optical sensitivity of the eye to white light in the center of the retina (foveola) for single cones varies from 0.00053 to 0.028 μm2·sr, and in the periphery of the retina (far periphery) for single rods from 0.011 to 0.575 μm2·sr, for single cones from 0.025 to 1.319 μm2·sr, for the groups of rods from 3859 to 204,094 μm2·sr and for the groups of cones from 2.5 to 131 μm2·sr. The value of the optical sensitivity of the eyes to white light for single photoreceptors of the first/second type in both regions of the retina in a mollusk, as well as for single cones in the center and groups of rods/cones in the periphery of the retina in humans, corresponds to the ambient light conditions during periods of activity and does not affect the spatial resolving power.

The Central Importance of E. coli and λ‎ Phage in the New Molecular Biology

This chapter considers two of the most important legacies of the Lederbergs’ pioneering work: the discoveries of the model organisms that would dominate molecular biology, E. coli and λ‎ bacteriophage. The Lederbergs’ introduction of E. coli as a convenient model organism shifted the direction of molecular genetics. Barbara McClintock’s discovery of jumping genes remained unappreciated for decades, until the field of molecular biology caught up to validate her transposable elements in bacteria. The discovery of restriction enzymes—the molecular scissors for precisely cutting DNA at specific sites, a prerequisite for genetic recombination techniques—emphasized the versatility of bacteriophage λ‎ as a powerful experimental tool. The discovery of specialized transduction by Larry Morse and Esther Lederberg hinted at the mechanisms of “host restriction.” Werner Arber and Daisy Dussoix discovered restriction endonucleases by building upon Esther Lederberg’s research with λ‎ phage and the differences between E. coli B and K-12.

DECISION MAKING UNDER LINGUISTIC UNCERTAINTY CONDITIONS ON BASE OF GENERALIZED FUZZY NUMBERS

This article is devoted to the problem of decision making under linguistic uncertainty. The effective method for modelling linguistic uncertainty is the fuzzy set theory. There are several types of fuzzy number types proposed by L. Zadeh: fuzzy type-1, fuzzy type-2, Z-numbers. Chen proposed concept of generalized fuzzy numbers. Generalized trapezoidal fuzzy numbers (GTFN) one of effective approach which can be used for modeling linguistic uncertainty. GFTN very convenient model which allow take in account second order uncertainty. GFTN are formalized and major operations are described as practical problem is considered group decision making for supplier selection. In this case the criteria assessments are expressed by experts in linguistic form. Group decision making model is presented as 2 step aggregation procedure, in first step is aggregated value of alternative by expert, in second step by criteria. Numerical example with four criteria and three alternatives are presented and solved.

COVID-19 Pandemisi ile Mücadele: COVID-19 Olgusu ve Hemşirelik Yönetimi

Millions of people lost their lives due to the Coronavirus (SARS-Cov-2) epidemic that started in China and spread rapidly all over the world. One of the most important problems in combating the disease was the loss of time in early diagnosis of infections and the ineffectiveness of the quarantine screen due to the incubation period of the disease, which can last up to fourteen days. This process poses a high risk to healthcare professionals and especially nurses, who are the first to come into contact with infected people. Currently, there is no definitive treatment for Covid-19. The only proven form of management is isolation and supportive care. Therefore, nurses, who are involved in every level of patient care, have an important role in combating this epidemic. Being a new emerging disease condition for the whole world, there has been created a huge gap regarding how the nursing care of patients with Covid-19 in hospitals will be. The aim of this article is to implement nursing interventions according to Gordon's Functional Health Patterns Model of a patient diagnosed with Covid-19, to highlight the important points that should be taken into consideration during their care, and to guide the nurses working in the field. Data were collected by face-to-face interviewing with the patient, and care was planned, applied and evaluated according to the model. The model of Functional Health Patterns can be used as an easy and convenient model for determining health care requirements and implementing nursing interventions for patient with a positive diagnosis of Covid-19.

Genome Reorganization during Erythroid Differentiation

Hematopoiesis is a convenient model to study how chromatin dynamics plays a decisive role in regulation of cell fate. During erythropoiesis a population of stem and progenitor cells becomes increasingly lineage restricted, giving rise to terminally differentiated progeny. The concerted action of transcription factors and epigenetic modifiers leads to a silencing of the multipotent transcriptome and activation of the transcriptional program that controls terminal differentiation. This article reviews some aspects of the biology of red blood cells production with the focus on the extensive chromatin reorganization during differentiation.

213 A Novel, Cost-Effective and Convenient Model for Simulating Facial Wound Repair

Introduction We describe the use of a novel synthetic simulation pad for learning complex facial wound management including local flaps. The simulation pad is a cost effective and convenient model of facial wounds. We have compared the use of animal tissue to the simulation pad in the context of a workshop for surgical trainees and collected feedback from delegates. Methods Feedback was collected from 14 of 16 attending delegates. Results It was clear from feedback that animal tissue is not an ideal model of facial wounds with 71% of delegates stating that they did not consider it to be high-fidelity. The synthetic pad was rated more favourably with 100% of delegates reporting that it was a valuable exercise and well designed for local flaps. Conclusions It is imperative that training opportunities are high quality and useful to clinical practice. Techniques learnt in the context of a course or workshop are more valuable where targeted practice may occur following learning. The use of a synthetic pad is more amenable to continued practice where it may be taken home following a workshop. Feedback from this event suggests a well-designed synthetic pad is more useful than animal tissue in learning local flaps.

Public-good driven release of heterogeneous resources leads to genotypic diversification of an isogenic yeast population in melibiose.

Adaptive diversification of an isogenic population, and its molecular basis has been a subject of a number of studies in the last few years. Microbial populations offer a relatively convenient model system to study this question. In this context, an isogenic population of bacteria (E. coli, B. subtilis, and Pseudomonas) has been shown to lead to genetic diversification in the population, when propagated for a number of generations. This diversification is known to occur when the individuals in the population have access to two or more resources/environments, which are separated either temporally or spatially. Here, we report adaptive diversification in an isogenic population of yeast, S. cerevisiae, when propagated in an environment containing melibiose as the carbon source. The diversification is driven due to a public good, enzyme α-galactosidase, leading to hydrolysis of melibiose into two distinct resources, glucose and galactose. The diversification is driven by a mutations at a single locus, in the GAL3 gene in the GAL/MEL regulon in the yeast.

The plasticity of lifespan in social insects

One of the central questions of ageing research is why lifespans of organisms differ so tremendously among related taxa and, even more surprising, among members of the same species. Social insects provide a particularly pronounced example for this. Here, we review previously published information on lifespan plasticity in social insects and provide new data on worker lifespan in the ant Cardiocondyla obscurior , which because of its relatively short lifespan is a convenient model to study ageing. We show that individual lifespan may vary within species with several reproductive and social traits, such as egg-laying rate, queen number, task, colony size and colony composition. For example, in Cardiocondyla , highly fecund queens live longer than reproductively less active queens, and workers tend to live longer when transferred into a novel social environment or, as we show with new data, into small colonies. We hypothesize that this plasticity of lifespan serves to maximize the reproductive output of the colony as a whole and thus the inclusive fitness of all individuals. The underlying mechanisms that link the social environment or reproductive status with lifespan are currently unresolved. Several studies in honeybees and ants indicate an involvement of nutrient-sensing pathways, but the details appear to differ among species. This article is part of the theme issue ‘Ageing and sociality: why, when and how does sociality change ageing patterns?'