Search results for "fat"
showing 10 items of 4644 documents
Mammalian Epidermis: A Compendium of Lipid Functionality
2022
Mammalian epidermis is a striking example of the role of lipids in tissue biology. In this stratified epithelium, highly specialized structures are formed that leverage the hydrophobic properties of lipids to form an impermeable barrier and protect the humid internal environment of the body from the dry outside. This is achieved through tightly regulated lipid synthesis that generates the molecular species unique to the tissue. Beyond their fundamental structural role, lipids are involved in the active protection of the body from external insults. Lipid species present on the surface of the body possess antimicrobial activity and directly contribute to shaping the commensal microbiota. Lipi…
CLA, “new nutrients”?
2005
International audience; Conjugated linoleic acid (CLA) refers to a class of positional and geometric dienoic isomers of linoleic acid. Chronic dietary supplementation with commercial isomeric mixtures sold as dietary supplements leads to a drop in fat mass in various species. The t10,c12-CLA isomer is responsible for this antiobesity effect.The reduction of fat mass is especially dramatic in the mouse, in which it is associated with a severe hyperinsulinemia, an insulin resistance and a massive liver steatosis. The origin of these adverse side effects and the putative chronology of events leading to CLA-mediated lipoatrophic syndrome are presented and discussed in this review. In Human, the…
Increasing temperature and productivity change biomass, trophic pyramids and community‐level omega‐3 fatty acid content in subarctic lake food webs
2021
Climate change in the Arctic is outpacing the global average and land-use is intensifying due to exploitation of previously inaccessible or unprofitable natural resources. A comprehensive understanding of how the joint effects of changing climate and productivity modify lake food web structure, biomass, trophic pyramid shape and abundance of physiologically essential biomolecules (omega-3 fatty acids) in the biotic community is lacking. We conducted a space-for-time study in 20 subarctic lakes spanning a climatic (+3.2 degrees C and precipitation: +30%) and chemical (dissolved organic carbon: +10 mg/L, total phosphorus: +45 mu g/L and total nitrogen: +1,000 mu g/L) gradient to test how temp…
Increasing concentration of polyunsaturated fatty acids in browning boreal lakes is driven by nuisance algaGonyostomum
2020
Elevated concentrations of dissolved organic carbon (DOC) promote browning of lakes, which alters the physicochemical properties of water and ecosystem functioning. However, browning‐induced changes in basal production of polyunsaturated fatty acids from the n‐3 and n‐6 families (n‐3 and n‐6 PUFA) in lakes are not fully understood. The concentrations of PUFA, which are micronutrients required to maintain growth and reproduction of consumers, have been suggested to either rise or decline in seston as a response to lake browning. Elevated DOC concentrations may also promote bacterial biomass and production and thus potentially increase the concentration of bacterial fatty acids (BAFA) in sest…
Dark matters : contrasting responses of stream biofilm to browning and loss of riparian shading
2022
Concentrations of terrestrial-derived dissolved organic carbon (DOC) in freshwater ecosystems have increased consistently, causing freshwater browning. The mechanisms behind browning are complex, but in forestry-intensive regions browning is accelerated by land drainage. Forestry actions in streamside riparian forests alter canopy shading, which together with browning is expected to exert a complex and largely unpredictable control over key ecosystem functions. We conducted a stream mesocosm experiment with three levels of browning (ambient vs. moderate vs. high, with 2.7 and 5.5-fold increase, respectively, in absorbance) crossed with two levels of riparian shading (70% light reduction vs.…
Coupling of iron and dissolved organic matter in lakes–selective retention of different size fractions
2023
AbstractIncreasing concentration of iron (Fe) is observed in many boreal lakes, such as for the present study in Oslo Østmark, SE-Norway (1983–2018). As Fe-regulating processes are complex and dynamic, the link between mobilizing and retention processes is still not well understood. A seasonal study (2017–2018) from two headwaters, with medium and high dissolved organic matter (DOM) concentrations, showed that the loading of Fe to the lakes was highly dependent on flow conditions. Significantly higher values of Fe were related to autumn and winter periods with high runoff of highly colored and aromatic DOM compared to a severe drought period with minimum Fe values in the lakes. Compared to …
Metabolic plasticity of mixotrophic algae is key for their persistence in browning environments
2022
Light availability is the main regulator of primary production, shaping photosynthetic communities and their production of ecologically important biomolecules. In freshwater ecosystems, increasing dissolved organic carbon concentrations, commonly known as browning, leads to lower light availability and the proliferation of mixotrophic phytoplankton. Here, a mixotrophic algal species (Cryptomonas sp.) was grown under five increasing dissolved organic carbon concentrations to uncover the plastic responses behind the success of mixotrophs in browning environments and their effect in the availability of nutritionally important biomolecules. In addition to the browning treatments, phototrophic, …
Coffee Restores Expression of lncRNAs Involved in Steatosis and Fibrosis in a Mouse Model of NAFLD
2021
Background and aim: Coffee intake exerts protective effects against non-alcoholic fatty liver disease (NAFLD), although without fully cleared mechanisms. In this study we aimed to assess whether coffee consumption may influence the expression of long non-coding RNAs (lncRNAs) in the liver. Methods: C57BL/6J mice were fed a 12-week standard diet (SD), high-fat diet (HFD) or HFD plus decaffeinated coffee solution (HFD + coffee). Expression of specific lncRNAs involved in NAFLD was analyzed by real-time PCR. For the most differentially expressed lncRNAs, the analysis was also extended to their mRNA targets. Results: Decaffeinated coffee intake reduced body weight gain, prevented NAFLD, lowered…
Mikołaj Rej o Fortunie Łudarce i Zwodnicy oraz o "świeckiej krotochwili"
2018
Tematem artykułu jest problematyka związana z zagadnieniem Fortuny w twórczości Mikołaja Reja. Motyw ten w literaturze i sztuce przybierał rozmaite kształty i konwencje. Fortuna w utworach Reja raz jawiła się jako bogini, kiedy indziej jako demon. Pisarz chętnie też sięgał po konwencję teatru świata, sceny cyrkowej, będącej domeną bogini Circe, turniejów czy pola walki. Jednak źródłem tych wszystkich metafor okazały się złożone relacje łączące plan Opatrzności z porządkiem natury, które dotyczyły uprzywilejowanego miejsca człowieka we wszechświecie. Dychotomiczność ludzkiej natury widoczna w rozróżnieniu na los i fortunę znalazła w twórczości Reja, wspartej na gruncie humanizmu chrześcijańs…
Conrad's "Gaspar Ruiz" and Turgenev's "King Lear of the Steppes"
2018
Joseph Conrad nie krył swojej irytacji po przeczytaniu recenzji Roberta Lynda opublikowanej 10 sierpnia 1908 w „Daily News”, która była próba ukazania osobliwych podobieństw pomiędzy Gasparem Ruizem Conrada i Stepowym Królem Lirem Turgieniewa. Chociaż jest możliwe wskazanie pewnych podobieństw między głównymi bohaterami obu utworów, nie ma podstaw, aby stwierdził, że Conrad, pisząc Gaspara Ruiza, inspirował się Stepowym Królem Lirem Turgieniewa. Tak jak złudne są próby przyporządkowania Conrada do jednej tradycji literackiej, tak samo nie można interpretować tekstów Conrada w jednym kontekście. Można założyć, że chociaż bohaterowie Turgieniewa i Conrada często są świadomi czyhającego na nic…