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Topic Review
Verrucomicrobia
Verrucomicrobia is a phylum of Gram-negative bacteria that contains only a few described species. The species identified have been isolated from fresh water, marine and soil environments and human faeces. A number of as-yet uncultivated species have been identified in association with eukaryotic hosts including extrusive explosive ectosymbionts of protists and endosymbionts of nematodes residing in their gametes. Verrucomicrobia are abundant within the environment, though relatively inactive. This phylum is considered to have two sister phyla: Chlamydiae and Lentisphaerae within the PVC group. The Verrucomicrobia phylum can be distinguished from neighbouring phyla within the PVC group by the presence of several conserved signature indels (CSIs). These CSIs represent unique, synapomorphic characteristics that suggest common ancestry within Verrucomicrobia and an independent lineage amidst other bacteria. CSIs have also been found that are shared by Verrucomicrobia and Chlamydiae exclusively of all other bacteria. These CSIs provide evidence that Chlamydiae is the closest relative to Verrucomicrobia, and that they are more closely related to one another than to the Planctomycetales. Verrucomicrobia might belong in the clade Planctobacteria in the larger clade Gracilicutes. In 2008, the whole genome of Methylacidiphilum infernorum (2.3 Mbp) was published. On the single circular chromosome, 2473 predicted proteins were found, 731 of which had no detectable homologs. These analyses also revealed many possible homologies with Proteobacteria.
  • 974
  • 21 Oct 2022
Biography
Veronica Vaida
Veronica Vaida (born 3 August 1950) is a Romanian-American Chemist and Professor at the University of Colorado Boulder. She is an expert in environmental chemistry and aerosols. Vaida was born in Bucharest.[1][2] Her parents were from Transylvania and met after World War II.[1] Her mother survived a Auschwitz concentration camp and her father was a political prisoner.[1] She attended a Hungar
  • 497
  • 30 Dec 2022
Topic Review
Vermicomposting on Greenhouse Gas Emission
The implementation of cutting-edge agricultural practices provides tools and techniques to drive climate-smart agriculture, reduce carbon emissions, and lower the carbon footprint. The alteration of climate conditions due to human activities poses a serious threat to the global agricultural systems. Greenhouse gas emissions (GHG) from organic waste management need urgent attention to optimize conventional composting strategies for organic wastes.
  • 1.2K
  • 21 Sep 2022
Topic Review
Vermicompost and Its Derivatives against Phytopathogenic Fungi
Vermicompost, a natural product obtained after decomposition of organic matter by the activity of earthworms, contribute to valuable bioavailable nutrients and use full microbes to increase soil fertility. The application of vermicompost in agriculture has resulted in remarkable improvements in crop yield as well as in crop health and nutritive qualities; it increases the soil mineral content, which enhances the survival of valuable microbes.
  • 631
  • 19 Apr 2022
Topic Review
Verbascum, Scrophulariaceae
Verbascum species (common mullein) have been widely used in Spanish folk medicine to treat pathologies related to the musculature, skeleton, and circulatory, digestive, and respiratory systems, as well as to treat infectious diseases and organ-sense illnesses.
  • 608
  • 24 Aug 2021
Biography
Vera Kistiakowsky
Vera Kistiakowsky (born 1928) is an United States research physicist, teacher, and arms control activist.[1] She is professor emerita at Massachusetts Institute of Technology in the physics department and Laboratory for Nuclear Science, and is an activist for women's participation in the sciences. Dr. Kistiakowsky is an expert in experimental particle physics and observational astrophysics.[2] S
  • 338
  • 15 Nov 2022
Topic Review
Ventx Family and Its Functional Similarities with Nanog
The Ventx family is one of the subfamilies of the ANTP (antennapedia) superfamily and belongs to the NK-like (NKL) subclass. Ventx is a homeobox transcription factor and has a DNA-interacting domain that is evolutionarily conserved throughout vertebrates. It has been extensively studied in Xenopus, zebrafish, and humans. The Ventx family contains transcriptional repressors widely involved in embryonic development and tumorigenesis in vertebrates. Several studies have documented that the Ventx family inhibited dorsal mesodermal formation, neural induction, and head formation in Xenopus and zebrafish. Moreover, Ventx2.2 showed functional similarities to Nanog and Barx1, leading to pluripotency and neural-crest migration in vertebrates. Among them, Ventx protein is an orthologue of the Ventx family in humans. Studies have demonstrated that human Ventx was strongly associated with myeloid-cell differentiation and acute myeloid leukemia. 
  • 465
  • 09 Mar 2022
Topic Review
Ventricular Fibrillation
A perennial task is to prevent the occurrence and/or recurrence of most frequent or life-threatening cardiac arrhythmias such as atrial fibrillation (AF) and ventricular fibrillation (VF). VF may be lethal in cases without an implantable cardioverter defibrillator or with failure of this device. Incidences of AF, even the asymptomatic ones, jeopardize the patient’s life due to its complication, notably the high risk of embolic stroke. Therefore, there has been a growing interest in subclinical AF screening and searching for novel electrophysiological and molecular markers. Considering the worldwide increase in cases of thyroid dysfunction and diseases, including thyroid carcinoma, we aimed to explore the implication of thyroid hormones in pro-arrhythmic signaling in the pathophysiological setting. The present review provides updated information about the impact of altered thyroid status on both the occurrence and recurrence of cardiac arrhythmias, predominantly AF. Moreover, it emphasizes the importance of both thyroid status monitoring and AF screening in the general population, as well as in patients with thyroid dysfunction and malignancies. Real-world data on early AF identification in relation to thyroid function are scarce. Even though symptomatic AF is rare in patients with thyroid malignancies, who are under thyroid suppressive therapy, clinicians should be aware of potential interaction with asymptomatic AF. It may prevent adverse consequences and improve the quality of life. This issue may be challenging for an updated registry of AF in clinical practice. Thyroid hormones should be considered a biomarker for cardiac arrhythmias screening and their tailored management because of their multifaceted cellular actions.
  • 711
  • 28 Oct 2020
Topic Review
Ventilation Systems in Wetland Plant Species
Ventilation systems rely on a passive molecular diffusion process, on pressurized gas flow, or Venturi-induced convection. 
  • 316
  • 06 Jul 2022
Topic Review
Venous Minus Arterial Carbon Dioxide Gradients in Monitoring
According to Fick’s principle, the total uptake of (or release of) a substance by tissues is the product of blood flow and the difference between the arterial and the venous concentration of the substance. Therefore, the mixed or central venous minus arterial CO2 content difference depends on cardiac output (CO). Assuming a linear relationship between CO2 content and partial pressure, central or mixed venous minus arterial PCO2 differences (Pcv-aCO2 and Pmv-aCO2) are directly related to CO. Nevertheless, this relationship is affected by alterations in the CO2Hb dissociation curve induced by metabolic acidosis, hemodilution, the Haldane effect, and changes in CO2 production (VCO2). In addition, Pcv-aCO2 and Pmv-aCO2 are not interchangeable. Despite these confounders, CO is a main determinant of Pcv-aCO2. Since in a study performed in septic shock patients, Pmv-aCO2 was correlated with changes in sublingual microcirculation but not with those in CO, it has been proposed as a monitor for microcirculation. The respiratory quotient (RQ)—RQ = VCO2/O2 consumption—sharply increases in anaerobic situations induced by exercise or critical reductions in O2 transport. This results from anaerobic VCO2 secondary to bicarbonate buffering of anaerobically generated protons. The measurement of RQ requires expired gas analysis by a metabolic cart, which is not usually available. Thus, some studies have suggested that the ratio of Pcv-aCO2 to arterial minus central venous O2 content (Pcv-aCO2/Ca-cvO2) might be a surrogate for RQ and tissue oxygenation. 
  • 233
  • 14 Jul 2023
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