Membrane Bioelectric Properties: a Biophysical approaches to cell physiology- A study revision

The contributions of Biophysics scientists measuring aspects of the membrane electricity have been so well thought of that multiple prizes have been given out in this field. The field has generated quantitative findings based on the Goldman field equation and the Nernst equation that provide understanding into the importance of sodium and potassium in cell signaling. The graded and action potentials that bring information in the interior the cell and all over the body are central in the considerations of the brain and the activities of muscle. This work covers the biophysics essential of these process.

Detection of Brucellosis in Blood of Cows in Some Farms of Khartoum State

Brucellosis is an infectious disease that affect human as well as animals. The disease is caused by exposure to a bacterial species belong to the genus Brucella. Brucellosis has wide distribution in sub-Saharan African countries, including Sudan in which the diagnosis remains a great challenge and basically depend on serology. The present study was carried out on five dairy cattle farms allegedly free from brucellosis, but with sporadic cases of abortion. As well-known Sudan has a many dairy industries with peri‑urban dairy establishments which built in order to improve milk availability to rural communities. The aim of this study is to estimate the prevalence of brucellosis in Sudan, using samples submitted to collect from different farms. Five farms were tested with Rose Bengal Test (RBT) and Enzyme-linked Immune-absorbent Assay (ELISA). Parallel testing was used to determine whether a farm was to be considered positive or not. The result showed that out of 70 cow’s Blood samples examine 22 (31.4%) had positive RBPT results while the rest (68.6%) had Negative RBPT results. Of the Five farms which were examined the positive cows were observed in only 2 farms. The results show the need to carry out surveillance of brucellosis in cattle in Sudan to understand the spatial distribution of the disease in the country. These surveillance could reduce the risk of Brucellosis spreading and consequently improvement will take place in the quality of livestock and their dairy product which consumed by the human in those areas.

Why the mechanisms of biological evolution are still not revealed?

Since the days of Darwin, it is generally accepted that biological evolution rests on three pillars: variability, inheritance and selection. It is believed that main sources of variability, mechanisms of inheritance and forms of natural selection have been clarified. Nevertheless, for more than 150 years since the publication of “Origin of Species” no consensus as to the mechanisms of evolution emerged. It is highly likely that the main obstacle in elucidating the mechanisms of evolution is the incompleteness of our knowledge regarding the sources of biological variability. The following sources of variability are universally recognized: gene mutations, gene recombination during meiosis and gene duplication. However, the role of the non-genic part of the genome, which makes up the vast majority of DNA in eukaryotes, remains unclear. For example, in human chromosomes, about 98% of DNA is represented by non-coding nucleotide sequences (ncDNAs). Although no one excludes their possible role in evolution, nevertheless, studies aimed at elucidating the participation of the non-genic part of the genome in variability, inheritance and selection are extremely small. The possible role of ncDNAs in the origin of biological variability in the eukaryotic genome and their evolution is discussed.

The origin of the human karyotype: its uniqueness, causes and effects

As is known, the diploid number of human chromosomes is 46, while in other higher primates, such as chimpanzees and gorillas, this number is 48. It has been established that a decrease in the number of chromosomes by two in humans is a result of the fusion of two autosomes into one chromosome in his karyotype ancestors. However, why such changes in chromosomes occurred among the highest primates in humans, their uniqueness, causes and consequences have not yet become the subject of special studies. We believe that the transition from 48 to 46 chromosomes, as well as changes in the composition, localization and amount of chromosomal heterochromatin regions in the karyotype of the ancestors of modern man turned out to be crucial in his formation as a biological species with all the ensuing consequences.

Evolution Without Genes: A Review

Evolution is a proven scientific fact. However, its mechanism is unknown. Modern Synthesis, the generally accepted theory of evolution is centered on species formation and population dynamics. According to Modern Synthesis, genes are considered the material basis of evolution. This circumstance is considered as the main obstacle in elucidating the mechanisms of evolution. It is proposed that any scientific hypothesis trying to explain the evolution of eukaryotes should meet the following requirement: all important evolutionary changes (nucleosomes, mitotic chromosomes, chromosome bands, cell nucleus, eukaryotic cells, sex, species, multicellular and homeothermic organisms, including modern humans) should occur based on one component of the genome. As is known, the genome of eukaryotic organisms consists of two components: euchromatin (coding DNA) and heterochromatin (noncoding DNA). A hypothesis is proposed that the evolution of eukaryotes occurred on the basis of a non-coding part of the genome. Therefore, with the advent of eukaryotic organisms, the material basis of evolution has evolved and noncoding DNAs have begun to play a leading role.

Advancements of transcriptome imputation and related transcriptome-wide association studies

Despite the progresses of genome-wide association studies (GWASs) in revealing genetic mechanisms of human complex traits, the basis through which most identified risk variants function are highly unknown and need further investigations as well as discoveries. Recent advancements of transcriptome predictions put the transcriptome-wide association studies (TWASs) forward into a new era. TWAS through imputed transcriptomes could discover more gene-trait associations and relevant joint-tissue TWAS via eQTL analysis provide insights into furthering elucidations about gene-level association studies in difficult-to-acquire tissues. This mini-review goes over the recent advancements of gene expression imputations as well as the gene-trait association studies, which highlight the importance of genetically regulated expression (GReX) in this area.

Cell thermoregulation and origin of homeothermic animals

Temperature has a fundamental influence in all chemical and biochemical reactions. It influences reaction rates, equilibrium amounts, viscosity, solubility, molecular arrangements and numeric other parameters. Temperature is important for all physiological processes. Maintaining the relative constancy of the internal temperature (temperature homeostasis) is a necessary condition for normal life. Some living beings maintain temperature homeostasis in the body due to external sources of energy (poikilothermy), others due to the energy of food consumption (homeothermy). However, it is unknown the origin of homeothermic organisms. Despite the fundamental similarity of the mechanisms of the central organ-based physiological thermoregulation, even among the higher vertebrates exists poikilothermy and homeothermy animals. It is assumed that homeothermy is not the result of the evolution of physiological mechanisms of thermoregulation. Homeothermy is the result of the evolution of non-coding DNAs in the genome, some of which formed the so-called chromosomal heterochromatin regions (HRs). Chromosomal HRs constitutes the material basis of cell thermoregulation, which is responsible for the removal of excess thermal energy from the nucleus into the cytoplasm. Homeothermic organisms, unlike poikilotherms capable of faster and more efficient leveling of temperature difference between the nucleus and the cytoplasm with all the ensuing consequences.

Mycobacterial polymerases: A possible drug target for TB treatment

Mycobacterium tuberculosis causes a deadly disease called Tuberculosis (TB). It enters in a healthy person through respiration and ultimately reaches into lung epithelial cells, where it attacks on lung macrophages to replicate in it and increase its population. For replication process, polymerase activity is essential. There are some compounds which inhibit polymerase activity or denature polymerase enzyme such as Humic acid, Heparin, Urea, Organic compounds, Phenolic compounds etc. In this manuscript, we are trying to show importance of M. tuberculosis pathogenesis by using polymerase activity that may be therapeutic drug target for TB.

Sex determination and Y chromosome constitutive heterochromatin

In many animals, including us, the genetic sex is determined at fertilization by sex chromosomes. Seemingly, the sex determination (SD) in human and animals is determined by the amount of constitutive heterochromatin on Y chromosome via cell thermoregulation. It is assumed the medulla and cortex tissue cells in the undifferentiated embryonic gonads (UEG) differ in vulnerability to the increase of the intracellular temperature. If the amount of the Y chromosome constitutive heterochromatin is enough for efficient elimination of heat difference between the nucleus and cytoplasm in rapidly growing UEG cells the medulla tissue survives. Otherwise it doomed to degeneration and a cortex tissue will remain in the UEG. Regardless of whether our assumption is true or not, it remains an open question why on Y chromosome there is a large constitutive heterochromatin block? What is its biological meaning? Does it relate to sex determination, sex differentiation and development of secondary sexual characteristics? If so, what is its mechanism: chemical or physical? There is no scientifically sound answer to these questions.