sequence of events
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Author(s):  
Fabai Wu ◽  
Daan R. Speth ◽  
Alon Philosof ◽  
Antoine Crémière ◽  
Aditi Narayanan ◽  
...  

AbstractEukaryotic genomes are known to have garnered innovations from both archaeal and bacterial domains but the sequence of events that led to the complex gene repertoire of eukaryotes is largely unresolved. Here, through the enrichment of hydrothermal vent microorganisms, we recovered two circularized genomes of Heimdallarchaeum species that belong to an Asgard archaea clade phylogenetically closest to eukaryotes. These genomes reveal diverse mobile elements, including an integrative viral genome that bidirectionally replicates in a circular form and aloposons, transposons that encode the 5,000 amino acid-sized proteins Otus and Ephialtes. Heimdallaechaeal mobile elements have garnered various genes from bacteria and bacteriophages, likely playing a role in shuffling functions across domains. The number of archaea- and bacteria-related genes follow strikingly different scaling laws in Asgard archaea, exhibiting a genome size-dependent ratio and a functional division resembling the bacteria- and archaea-derived gene repertoire across eukaryotes. Bacterial gene import has thus likely been a continuous process unaltered by eukaryogenesis and scaled up through genome expansion. Our data further highlight the importance of viewing eukaryogenesis in a pan-Asgard context, which led to the proposal of a conceptual framework, that is, the Heimdall nucleation–decentralized innovation–hierarchical import model that accounts for the emergence of eukaryotic complexity.


2022 ◽  
Vol 10 (2) ◽  
pp. 01-06
Author(s):  
Frank Mayer

Bacteria possess an EF-Tu-based cytoskeleton.This article presents a short review. A number of questions which are not discussed in the former publications can be asked, such as: all bacteria possess a ribosomal protein synthesis system and, hence, also EF-Tu. EF-Tu is produced in an amount that is higher than the need for a function as translation elogation factor in ribsomal protein synthesis. This article tries to answer the question regarding the surplus of EF-Tu: formation of a "cell-wide web" by self-assembly as a feafure that stabilizes cell integrity. An additional question can be asked: what is the origin of this bacterial cytoskeleton? This article contains a speculation on this topic. A third question regards the'ntteructjon of ribosomes in the process of protemsynthesis: does the EF-Tu protein move to the ribosome, or does the ribosome move to the EF-Tu intergated in a fibril of the bacterial cytoskeleton? The former publication depicts electron micrographs which show colocalizatton of botth entities. EF-Tu is an example for aprotein with two independent functions: participation in the ribosomal protein synthesis as a kanslation elongation factor, and component of a bacterial cytoskeleton. This situation can open up a discussion ofthe sequence of events and states of early cells during evolution.


Development ◽  
2022 ◽  
Vol 149 (1) ◽  
Author(s):  
Silvan Spiri ◽  
Simon Berger ◽  
Louisa Mereu ◽  
Andrew DeMello ◽  
Alex Hajnal

ABSTRACT During Caenorhabditis elegans vulval development, the uterine anchor cell (AC) first secretes an epidermal growth factor (EGF) to specify the vulval cell fates and then invades the underlying vulval epithelium. By doing so, the AC establishes direct contact with the invaginating primary vulF cells and attaches the developing uterus to the vulva. The signals involved and the exact sequence of events joining these two organs are not fully understood. Using a conditional let-23 EGF receptor (EGFR) allele along with novel microfluidic short- and long-term imaging methods, we discovered a specific function of the EGFR in the AC during vulval lumen morphogenesis. Tissue-specific inactivation of let-23 in the AC resulted in imprecise alignment of the AC with the primary vulval cells, delayed AC invasion and disorganized adherens junctions at the contact site forming between the AC and the dorsal vulF toroid. We propose that EGFR signaling, activated by a reciprocal EGF cue from the primary vulval cells, positions the AC at the vulval midline, guides it during invasion and assembles a cytoskeletal scaffold organizing the adherens junctions that connect the developing uterus to the dorsal vulF toroid. Thus, EGFR signaling in the AC ensures the precise alignment of the two developing organs.


2022 ◽  
Vol 962 (1) ◽  
pp. 012054
Author(s):  
A V Kurguzova ◽  
M V Morozov

Abstract The history of the the discovery of world’s largest Ni-Cu-PGM deposits of Norilsk-Talnakh is revised. The 1866 prospecting and geographic expedition of Innokenty Lopatin and Friedrich Schmidt, studied the lowest Yenissei territories, and collected information and mineralogical samples (chalcopyrite from ‘copper slates’) proving by this the presence of a copper ore deposit in the Norilsk mountains. The deposit was developed by at least two adits since 1865 and was managed by brothers Pyotr and Cyprian Sotnikov from the settlement of Dudino (now Dudinka). This information was documented in the diaries by I. Lopatin and was reported by F. Schmidt in transactions of the Saint Petersburg Academy of Sciences. After the ‘re-discovery’ of the deposit in the 20th century the followers have ignored, omitted and incorrectly cited the information published by Friedrich Schmidt in 1869 and 1872, as well as its republishing made by Vladimir Obrutchev in 1917. The real sequence of events resulting in the discovery of Norilsk deposits has to be rewritten. In memoriam of Sergey Gorbunov (1952–2021), archaeologist, traveler, Sakhalin history specialist


2021 ◽  
Vol 14 (4) ◽  
pp. 1841-1862
Author(s):  
Sally A El Awdan ◽  
Gihan F. Asaad

Liver fibrosis is considered: “a pathological repairing process in liver injuries leading to extracellular cell matrix (ECM) accumulation evidencing chronic liver diseases”. Chronic viral hepatitis, alcohol consumption, autoimmune diseases as well as non-alcoholic steatohepatitis are from the main causes of liver fibrosis (Lee et al., 2015; Mieli-Vergani et al., 2018). Hepatic stellate cells (HSCs) exist in the sinus space next to the hepatic epithelial cells as well as endothelial cells (Yin et al., 2013). Normally, HSCs are quiescent and mainly participate in fat storage and in the metabolism of vitamin A. HSCs are produced during liver injury and then transformed into myofibroblasts. The activated HSCs resulted in a sequence of events considered as marks fibrosis. The activation of HSCs mostly express alpha smooth muscle actin (α-SMA). Moreover, ECM is synthesized and secreted by HSCs that affects markedly the structure and function of the liver tissue leading to fibrosis (Tsuchida et al., 2017; Han et al., 2020). Hence, activated HSCs are attracting attention as potential targets in liver fibrosis. Many signaling molecules are involved in HSCs activation first and foremost, platelet-derived growth factor (PDGF) and transforming growth factor-beta (TGF-β) (Tsuchida et al., 2017; Wang et al., 2020c) as interfering the PDGF or TGF-β signaling pathways is a growing field for liver fibrosis treatment.


Author(s):  
RICARDO SIMÃO ◽  
FRANCISCO ROSENDO ◽  
LUCAS WARDIL

The role of luck on individual success is hard to be investigated empirically. Simplified mathematical models are often used to shed light on the subtle relations between success and luck. Recently, a simple model called “Talent versus Luck” showed that the most successful individual in a population can be just an average talented individual that is subjected to a very fortunate sequence of events. Here, we modify the framework of the TvL model such that in our model the individuals’ success is modelled as an ensemble of one-dimensional random walks. Our model reproduces the original TvL results and, due to the mathematical simplicity, it shows clearly that the original conclusions of the TvL model are the consequence of two factors: first, the normal distribution of talents with low standard deviation, which creates a large number of average talented individuals; second, the low number of steps considered, which allows the observation of large fluctuations. We also show that the results strongly depend on the relative frequency of good and bad luck events, which defines a critical value for the talent: in the long run, the individuals with high talent end up very successful and those with low talent end up ruined. Last, we considered two variations to illustrate applications of the ensemble of random walks model.


2021 ◽  
pp. 1-21
Author(s):  
Manish Arora ◽  
Paul Curtin ◽  
Austen Curtin ◽  
Christine Austin ◽  
Alessandro Giuliani

Chapter 1 outlines the axioms of the biodynamic interface conjecture, each of which are detailed in subsequent chapters. It is shown that in order to properly identify and characterize any dynamic system, it is necessary to identify more than a few isolated “things” making up the pattern. Rather, one must know the sequence of events and the organization of the system in order to understand and recognize its function in both space and time. In essence, Environmental Biodynamics seeks to understand how the environment and human physiology interact through a focus on functional interfaces; specifically the focus is on the patterns that emerge in the integration of the environment into human physiology rather than on isolated “snapshots” taken in passing.


Author(s):  
Lech Giemza

The author of this article makes a comparative interpretation of Tadeusz Różewicz’s novella Piwo [Beer] and its film adaptation directed by Stanisław Różewicz. Among other things, the researcher asks the question: to what extent do the differences between the film material and the text material – in this particular case – stem from the specificity of the film language and its autonomy in relation to literature? He believes that this can be explained by the fact that the action of the film takes place only in the station’s waiting room; the movement between the inn and the station, undoubtedly justified in the case of the original text, would be for the viewer something illegible and disturbing to the sequence of events. The multilevel linguistic code forcing symbolic readings, so important in Różewicz’s prose, seems, however, not to be translatable (at least not in its entirety) into the language of the image, which enforces a number of other artistic solutions. It seems that the film work here speaks the language of symbols on a different level. 


Medicina ◽  
2021 ◽  
Vol 58 (1) ◽  
pp. 8
Author(s):  
María Cecilia Castro ◽  
Hernán Gonzalo Villagarcía ◽  
Carolina Lisi Román ◽  
Bárbara Maiztegui ◽  
Luis Emilio Flores ◽  
...  

Background and Objectives: The work was aimed to determine the chronological sequence of events triggered by a fructose-rich diet (FRD) (10% w/v in the drinking water) in normal rats. Material and Methods: Serum parameters, liver and islet markers of metabolism, inflammation and oxidative stress were determined weekly for 21 days. Results: At the end of the first week, rats fed with a FRD showed an early increase in circulating triglycerides, fat liver deposit, and enzymatic activity of liver glucokinase and glucose-6-phosphate dehydrogenase (G6P-DH). After two weeks of such a diet, liver glucose-6-phosphatase (G6Pase) activity and liver oxidative stress markers were significantly increased. Liver sterol regulatory element-binding protein 1c (SREBP1c) mRNA also increased in the second week while their target genes fatty acid synthase (FAS) and glycerol-3-phosphate dehydrogenase (GPAT) enhanced their expression at the third week. Liver and pancreatic inflammation markers also enhanced their gene expression in the last week of treatment. Whereas both control and FRD rats remained normoglycemic throughout the entire period of treatment, blood insulin levels were significantly higher in FRD animals at the third week, thereby evidencing an insulin-resistant state (higher HOMA-IR, HOMA-B and HIS indexes). Pancreatic islets isolated from rats fed with a FRD for 3 weeks also increased glucose-induced insulin secretion (8.3 and 16.7 mM). Conclusions: FRD induces asynchronous changes involving early hypertriglyceridemia together with intrahepatic lipid deposit and metabolic disturbances from week one, followed by enhanced liver oxidative stress, liver and pancreas inflammation, pancreatic β-cell dysfunction, and peripheral insulin-resistance registered at the third week. Knowledge of time-course adaptation mechanisms involved in our rat model could be helpful in developing appropriate strategies to prevent the progression from prediabetes to Type 2 diabetes (T2D) triggered by unhealthy diets.


Author(s):  
Giacomo Ranzani

The article scrutinises Cae­sar’s De bello Gallico narrative through offering an exhaustive analysis of one of the most relevant narrative strategies the Cae­sarian storytelling relies on: the artful representation of Cae­sar’s intervention in battle. The paper firstly illustrates how the accounts of Cae­sar’s activities during the combat are always depicted, across the seven books, as the turning point of a difficult situation for the Romans. Moreover, the article clarifies that these scenes share not only the exceptional results achieved by the commander, but also significant similarities on the diegetic, stylistic and rhetorical level. On this basis, the article argues that such analogies are part of a narrative strategy operating whenever the text describes Cae­sar’s action in a combat. A stylistic and rhetorical investigation on four exemplary cases is undertaken (Gall. 2.15-28, 3.14-15, 6.8 and 7.87); these passages are representative of the De bello Gallico general trend in depicting the author’s efforts during a struggle. The enquiry reveals that the Latin text always presents a comparable sequence of events preceding and following the account of Cae­sar’s accomplishments in battle and that similar lexicon and rhetorical figures are employed to support Cae­sar’s self-presentation as infallible commander.


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