Positive Feedback Keeps Duration of Mitosis Temporally Insulated from Upstream Cell-Cycle Events

Cell division is characterized by a sequence of events by which a cell gives rise to two daughter cells. Quantitative measurements of cell-cycle dynamics in single cells showed that despite variability in G1-, S-, and G2 phases, duration of mitosis is short and remarkably constant. Surprisingly, there is no correlation between cell-cycle length and mitotic duration, suggesting that mitosis is temporally insulated from variability in earlier cell-cycle phases. By combining live cell imaging and computational modeling, we showed that positive feedback is the molecular mechanism underlying the temporal insulation of mitosis. Perturbing positive feedback gave rise to a sluggish, variable entry and progression through mitosis and uncoupled duration of mitosis from variability in cell cycle length. We show that positive feedback is important to keep mitosis short, constant, and temporally insulated and anticipate it might be a commonly used regulatory strategy to create modularity in other biological systems

Frontiers of molecular biology of cancer

Cancer is rooted in genetic background, with the expression of oncogenesis playing a pivotal role in the early stages of tumor formation. Acquired mutations in somatic cells primarily contribute to the development of most common cancers, while specific germline mutations are responsible for rare hereditary cancer syndromes. Within the realm of cancer-associated genes, oncogenes undergo activation, exhibiting phenotypic dominance, whereas tumor suppressor genes experience inactivation, displaying phenotypic recessiveness. The ongoing effort to improve our knowledge about molecular mechanisms involves defining pathways influencing cancer therapy. Technological advancements have made it possible to identify genes integral to cancer development and have significantly contributed to the growing success of precision medicine in oncology, with targeted therapies directed against tumors and components of the tumor microenvironment. This Special Issue, titled “Molecular Biology of Cancer—Implications for Diagnosis and Treatment”, comprises a total of eight contributions. These include five original articles and three reviews, offering fresh insights into cancer biology, molecular genetics, and innovative therapeutic approaches

Workplace Happiness and influencing factors: A review of literature

Abstract Research shows that people who are happy at work perform better and productive than those who are not. The concept of happiness is associated with individual’s subjective well-being. Workplace happiness is decisive for improving productivity in any organization. Happy people are productive people while those who are not may not pay full attention to any assignment. It is allied with positive constructs such as pleasure, satisfaction and well-being. The present paper is about in-depth search for influencing factors on workplace happiness based on the review of literature. It is clearly evident that positive work engagement, work environment. Income, freedom and work-life balance plays a major role in workplace happiness

Institutional histories, seasonal floodplains (mares), and livelihood impacts of fish stocking in the Inner Niger River Delta of Mali

The Community-based Fish Culture in Seasonal Floodplains and Irrigation Systems (CBFC) project is a five year research project supported by the Challenge Program on Water and Food (CPWF), with the aim of increasing productivity of seasonally occurring water bodies through aquaculture. The project has been implemented in Bangladesh, Cambodia, China, Mali and Vietnam, where technical and institutional options for community based aquaculture have been tested. The project began in 2005 and was completed in March 2010. The seasonally flooded depressions in the Inner Niger Delta (known as mares) represent a critical fishery resource for the inhabitants of the village of Komio, and at present, access is open to all residents. A proposal to build stocked fish enclosures in the main village mare presents potential benefits and risks. On one hand, overall productivity in the mare could be significantly increased, providing important sources of protein and cash during the annual drought period, when few livelihood activities can be performed and when village livelihoods are at their most vulnerable. Enhanced productivity in mares may also decrease local household pressures for seasonal labor migration. On the other hand, a resulting increase in the value of these mares may encourage elite capture of project benefits or rentseeking by certain village leaders of the landowning Marka ethnic group. Using qualitative interviews and focus group discussions, the study provides evidence of how local institutional and leadership capacity for equitable common property resource management have evolved since the introduction of irrigated farming systems (known as PΘrimΦtres IrriguΘs Villageois or PIVs) in the 1990s.Fishing rights, River fisheries, Livelihoods

Uncovering distinct protein-network topologies in heterogeneous cell populations

Background: Cell biology research is fundamentally limited by the number of intracellular components, particularly proteins, that can be co-measured in the same cell. Therefore, cell-to-cell heterogeneity in unmeasured proteins can lead to completely different observed relations between the same measured proteins. Attempts to infer such relations in a heterogeneous cell population can yield uninformative average relations if only one underlying biochemical network is assumed. To address this, we developed a method that recursively couples an iterative unmixing process with a Bayesian analysis of each unmixed subpopulation. Results: Our approach enables to identify the number of distinct cell subpopulations, unmix their corresponding observations and resolve the network structure of each subpopulation. Using simulations of the MAPK pathway upon EGF and NGF stimulations we assess the performance of the method. We demonstrate that the presented method can identify better than clustering approaches the number of subpopulations within a mixture of observations, thus resolving correctly the statistical relations between the proteins. Conclusions: Coupling the unmixing of multiplexed observations with the inference of statistical relations between the measured parameters is essential for the success of both of these processes. Here we present a conceptual and algorithmic solution to achieve such coupling and hence to analyze data obtained from a natural mixture of cell populations. As the technologies and necessity for multiplexed measurements are rising in the systems biology era, this work addresses an important current challenge in the analysis of the derived data.Fil: Wieczorek, Jakob. Universitat Dortmund; AlemaniaFil: Malik Sheriff, Rahuman S.. Institut Max Planck fur Molekulare Physiologie; Alemania. Imperial College London; Reino Unido. European Bioinformatics Institute. European Molecular Biology Laboratory; Reino UnidoFil: Fermin, Yessica. Universitat Dortmund; AlemaniaFil: Grecco, Hernan Edgardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; Argentina. Institut Max Planck fur Molekulare Physiologie; AlemaniaFil: Zamir, Eli. Institut Max Planck fur Molekulare Physiologie; AlemaniaFil: Ickstadt, Katja. Universitat Dortmund; Alemani

SPERMATOZOA- AN UNIQUE REPRESENTATION OF OXYGENANTIOXIDANT PARADOX

Infertility has become a common occurrence in males. Oxidant stress has become one of the most common causes of infertility. X-irradiation, or exposure to environmental toxicants and the physical conditions of varicocele and cryptorchidism have been demonstrated to increase testicular oxidative stress. The resultant oxidant stress may lead to an increase in germ cell apoptosis and subsequent hypospermatogenesis. This may result in changes in the dynamics of testicular microvascular blood flow, endocrine signaling, and germ cell apoptosis. Oxidative stress, therefore, becomes a major and the most probable finding associated with male infertility. This raises a possibility of application of antioxidant therapy that could help alleviate the reduced spermatogenesis

ISOLATION AND CHARACTERIZATION OF ACTINOMYCETES FROM SOIL OF AD-DAWADMI, SAUDI ARABIA AND SCREENING THEIR ANTIBACTERIAL ACTIVITIES

Objective: To isolate and characterize novel actinomycetes and to evaluate their antibacterial activity against drug-resistant pathogenic bacteriaMethods: In the present study, 19 soil samples were collected from different localities of Ad-Dawadmi, Saudi Arabia. Actinomycetes were isolated from these samples using serial dilution and plating method on Actinomycetes isolation agar supplemented with nalidixic acid and actidione to inhibit bacteria and fungi. Crude extracts of potential actinomycetes were produced by submerged fermentation. The antimicrobial activity of crude extracts of actinomycetes was tested against different bacteria using the agar well diffusion method. Characterization of the isolates was done by morphological, physiological and biochemical methods.Results: A total of 9 (47%) isolates of actinomycetes were isolated from 19 different soil samples tested. Among them, 4 (44%) isolates confirmed as Streptomyces sp. showed potential antimicrobial activity against one or more test organisms. Crude extracts were made from these 4 actinomycetes isolates(DOM1, DOM3, DP3, DP4)and tested for their antibacterial activities against 4 different clinical bacterial strains (Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Enterococcus). Crude extract from DP3 isolate showed highest antibacterial activity against all the four test organisms (28 mm, 21 mm, 20 mm and 18 mm) respectively and DP4 showed lowest antibacterial activity against all the four test organisms (14 mm, 12 mm, 0 mm, 6 mm) respectively. The highest zone of inhibition was shown by DP3 against Staphylococcus aureus (28 mm) and Escherichia coli was resistant for DP4. Most of the Inhibition zones produced by crude extracts showed significant differences when compared with control, tested against test organisms (P<0.05). Inhibition zones produced by DP3 and DOM1 against Staphylococcus aureus were 28 mm and 23 mm, respectively which were strong active when compared with control Ciprofloxacin (18 mm).Conclusion: Further studies for purification of bioactive metabolites and molecular characterization analysis of isolated Streptomyces sp. are in progress which would be helpful in discovering novel compounds of commercial value

The future cost of cancer in South Africa: An interdisciplinary cost management strategy

The exponential rise in cancer costs in South Africa (SA) was illustrated in a recent Sunday Times article entitled ‘The cost of cancer can be a debt sentence’.[1] Our minister of health talks of a ‘war’ against the high costs of cancer drugs, and epidemiologists project a sharply rising incidence. Eminent international medical journals, such as The Lancet, underline the fact that cancer cost is a growing international problem that confronts even the richest countries. Indeed, the question may be posed: if richer countries in the world are battling to cover the costs of cancer, what is the prognosis for SA