scholarly journals Ultrastructure of ovarian follicular epithelium of the Amazonian fish Pseudotylosurus microps (Teleostei: Belonidae): morphological and histochemical characterization of the intercellular deposits

2001 ◽  
Vol 61 (1) ◽  
pp. 133-140 ◽  
Author(s):  
C. CRUZ-LANDIM ◽  
M. A. CRUZ-HÖFLING
Keyword(s):  
Chemical Nature ◽  
Early Growth ◽  
Follicular Epithelium ◽  
Intercellular Spaces ◽  
Amazonian Fish ◽  
Primary Oocyte ◽  
And Function ◽  
Histochemical Characterization

The present paper reports the presence of great quantities of electrondense intercellular material in the follicular epithelium of P. microps. The material apparently is uptaken from circulation and enter the follicle through the intercellular spaces accumulating in the epithelial median-apical intercellular spaces and in perioocytic space. The accumulation starts in the early growth of the primary oocyte and proceed until vitellogenesis. The possible chemical nature and function of the deposits are discussed.

Functional characterization of human brown adipose tissue metabolism

2020 ◽  
Vol 477 (7) ◽  
pp. 1261-1286 ◽  
Author(s):  
Marie Anne Richard ◽  
Hannah Pallubinsky ◽  
Denis P. Blondin
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Functional Characterization ◽  
Human Infants ◽  
Positron Emission ◽  
Brown Adipose ◽  
Treatment Of Obesity ◽  
And Function

Brown adipose tissue (BAT) has long been described according to its histological features as a multilocular, lipid-containing tissue, light brown in color, that is also responsive to the cold and found especially in hibernating mammals and human infants. Its presence in both hibernators and human infants, combined with its function as a heat-generating organ, raised many questions about its role in humans. Early characterizations of the tissue in humans focused on its progressive atrophy with age and its apparent importance for cold-exposed workers. However, the use of positron emission tomography (PET) with the glucose tracer [18F]fluorodeoxyglucose ([18F]FDG) made it possible to begin characterizing the possible function of BAT in adult humans, and whether it could play a role in the prevention or treatment of obesity and type 2 diabetes (T2D). This review focuses on the in vivo functional characterization of human BAT, the methodological approaches applied to examine these features and addresses critical gaps that remain in moving the field forward. Specifically, we describe the anatomical and biomolecular features of human BAT, the modalities and applications of non-invasive tools such as PET and magnetic resonance imaging coupled with spectroscopy (MRI/MRS) to study BAT morphology and function in vivo, and finally describe the functional characteristics of human BAT that have only been possible through the development and application of such tools.

Parasite defense mechanisms in bees: behavior, immunity, antimicrobials, and symbionts

2019 ◽  
Vol 4 (1) ◽  
pp. 59-76 ◽  
Author(s):  
Alison E. Fowler ◽  
Rebecca E. Irwin ◽  
Lynn S. Adler
Keyword(s):  
Defense Mechanisms ◽  
Poor Quality ◽  
Future Research ◽  
Immune Priming ◽  
Social Bees ◽  
Bee Health ◽  
Landscape Scales ◽  
And Function ◽  
Solitary Species

Parasites are linked to the decline of some bee populations; thus, understanding defense mechanisms has important implications for bee health. Recent advances have improved our understanding of factors mediating bee health ranging from molecular to landscape scales, but often as disparate literatures. Here, we bring together these fields and summarize our current understanding of bee defense mechanisms including immunity, immunization, and transgenerational immune priming in social and solitary species. Additionally, the characterization of microbial diversity and function in some bee taxa has shed light on the importance of microbes for bee health, but we lack information that links microbial communities to parasite infection in most bee species. Studies are beginning to identify how bee defense mechanisms are affected by stressors such as poor-quality diets and pesticides, but further research on this topic is needed. We discuss how integrating research on host traits, microbial partners, and nutrition, as well as improving our knowledge base on wild and semi-social bees, will help inform future research, conservation efforts, and management.

Gaunilo Parodies Anselm

2014 ◽  
Vol 17 (1) ◽  
pp. 45-71
Author(s):  
Geo Siegwart
Keyword(s):  
Detailed Comparison ◽  
The Third ◽  
Common Structure ◽  
Logical Reconstruction ◽  
Points Of View ◽  
And Function

The main objective is an interpretation of the island parody, in particular a logical reconstruction of the parodying argument that stays close to the text. The parodied reasoning is identified as the proof in the second chapter of the Proslogion, more specifically, this proof as it is represented by Gaunilo in the first chapter of his Liber pro insipiente. The second task is a detailed comparison between parodied and parodying argument as well as an account of their common structure. The third objective is a tentative characterization of the nature and function of parodies of arguments. It seems that parodying does not add new pertinent points of view to the usual criticism of an argument.

Preparation and Characterization of β-glucosidase Films for Stabilization and Handling in Dry Configurations

2020 ◽  
Vol 21 (8) ◽  
pp. 741-747
Author(s):  
Liguang Zhang ◽  
Yanan Shen ◽  
Wenjing Lu ◽  
Lengqiu Guo ◽  
Min Xiang ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Protein Function ◽  
Protein Stabilization ◽  
Functional Protein ◽  
Elongation At Break ◽  
Gelatin Films ◽  
The Stability ◽  
And Function ◽  
General Method

Background: Although the stability of proteins is of significance to maintain protein function for therapeutical applications, this remains a challenge. Herein, a general method of preserving protein stability and function was developed using gelatin films. Method: Enzymes immobilized onto films composed of gelatin and Ethylene Glycol (EG) were developed to study their ability to stabilize proteins. As a model functional protein, β-glucosidase was selected. The tensile properties, microstructure, and crystallization behavior of the gelatin films were assessed. Result: Our results indicated that film configurations can preserve the activity of β-glucosidase under rigorous conditions (75% relative humidity and 37°C for 47 days). In both control films and films containing 1.8 % β-glucosidase, tensile strength increased with increased EG content, whilst the elongation at break increased initially, then decreased over time. The presence of β-glucosidase had a negligible influence on tensile strength and elongation at break. Scanning electron-microscopy (SEM) revealed that with increasing EG content or decreasing enzyme concentrations, a denser microstructure was observed. Conclusion: In conclusion, the dry film is a promising candidate to maintain protein stabilization and handling. The configuration is convenient and cheap, and thus applicable to protein storage and transportation processes in the future.

Molecular characterization of SARS-CoV-2

2020 ◽  
Vol 20 ◽  
Author(s):  
Miribane Dërmaku-Sopjani ◽  
Mentor Sopjani
Keyword(s):  
Public Health ◽  
Drug Targets ◽  
Virus Genome ◽  
Health Crisis ◽  
Public Health Crisis ◽  
Therapeutic Drugs ◽  
New Public Health ◽  
New Public ◽  
And Function

Abstract:: The coronavirus disease 2019 (COVID-19) is currently a new public health crisis threatening the world. This pandemic disease is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The virus has been reported to be originated in bats and by yet unknown intermediary animals were transmitted to humans in China 2019. The SARSCoV- 2 spreads faster than its two ancestors the SARS-CoV and Middle East respiratory syndrome coronavirus (MERSCoV) but has reduced fatality. At present, the SARS-CoV-2 has caused about a 1.16 million of deaths with more than 43.4 million confirmed cases worldwide, resulting in a serious threat to public health globally with yet uncertain impact. The disease is transmitted by inhalation or direct contact with an infected person. The incubation period ranges from 1 to 14 days. COVID-19 is accompanied by various symptoms, including cough, fatigue. In most people the disease is mild, but in some other people, such as in elderly and people with chronic diseases, it may progress from pneumonia to a multi-organ dysfunction. Many people are reported asymptomatic. The virus genome is sequenced, but new variants are reported. Numerous biochemical aspects of its structure and function are revealed. To date, no clinically approved vaccines and/or specific therapeutic drugs are available to prevent or treat the COVID-19. However, there are reported intensive researches on the SARSCoV- 2 to potentially identify vaccines and/or drug targets, which may help to overcome the disease. In this review, we discuss recent advances in understanding the molecular structure of SARS-CoV-2 and its biochemical characteristics.

kangaroo, a Mobile Element From Volvox carteri, Is a Member of a Newly Recognized Third Class of Retrotransposons

Genetics ◽  
2002 ◽  
Vol 162 (4) ◽  
pp. 1617-1630
Author(s):  
Leonard Duncan ◽  
Kristine Bouckaert ◽  
Fay Yeh ◽  
David L Kirk
Keyword(s):  
Genomic Structure ◽  
Mobile Element ◽  
Direct Repeat ◽  
Structural Features ◽  
Volvox Carteri ◽  
Developmentally Regulated ◽  
Closed Circle ◽  
Integration Mechanisms ◽  
And Function

Abstract Retrotransposons play an important role in the evolution of genomic structure and function. Here we report on the characterization of a novel retrotransposon called kangaroo from the multicellular green alga, Volvox carteri. kangaroo elements are highly mobile and their expression is developmentally regulated. They probably integrate via double-stranded, closed-circle DNA intermediates through the action of an encoded recombinase related to the λ-site-specific integrase. Phylogenetic analysis indicates that kangaroo elements are closely related to other unorthodox retrotransposons including PAT (from a nematode), DIRS-1 (from Dictyostelium), and DrDIRS1 (from zebrafish). PAT and kangaroo both contain split direct repeat (SDR) termini, and here we show that DIRS-1 and DrDIRS1 elements contain terminal features structurally related to SDRs. Thus, these mobile elements appear to define a third class of retrotransposons (the DIRS1 group) that are unified by common structural features, genes, and integration mechanisms, all of which differ from those of LTR and conventional non-LTR retrotransposons.

Characterization of diacylglycerol acyltransferase 2 from Idesia polycarpa and function analysis

2021 ◽  
Vol 234 ◽  
pp. 105023
Author(s):  
Ruishen Fan ◽  
Gui Cai ◽  
Xuanyuan Zhou ◽  
Yuxin Qiao ◽  
Jiabao Wang ◽  
...  
Keyword(s):  
Function Analysis ◽  
Diacylglycerol Acyltransferase ◽  
And Function
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