scholarly journals Transcriptome Profiles of the Liver in Two Cold-Exposed Sheep Breeds Revealed Different Mechanisms and Candidate Genes for Thermogenesis

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Dan Jiao ◽  
Kaixi Ji ◽  
Wenqiang Wang ◽  
Hu Liu ◽  
Jianwei Zhou ◽  
...  
Keyword(s):  
Candidate Genes ◽  
Heat Production ◽  
Theoretical Foundation ◽  
Nonshivering Thermogenesis ◽  
Ewe Lambs ◽  
Air Temperatures ◽  
Liver Transcriptome ◽  
The Difference ◽  
Shivering Thermogenesis

Cold-induced thermogenesis plays an important role in the survival of lambs exposed to low air temperatures. The liver produces and mediates heat production in mammals; however, to date, little is known about the role of liver genes in cold-induced thermogenesis in lambs. In this study, the difference in the liver transcriptome between Altay and Hu ewe lambs was compared. Because of different backgrounds of the two breeds, we hypothesized that the transcriptome profiles of the liver would differ between breeds when exposed to cold. Cold-exposed Altay lambs activated 8 candidate genes (ACTA1, MYH1, MYH2, MYL1, MYL2, TNNC1, TNNC2, and TNNT3) involved in muscle shivering thermogenesis; 3 candidate genes (ATP2A1, SLN, and CKM) involved in muscle nonshivering thermogenesis related to the Ca2+ signal and creatine cycle; and 6 candidate genes (PFKM, ALDOC, PGAM2, ENO2, ENO3, and ENO4) involved in enhancing liver metabolism. In contrast, the liver may not act as the main tissue for thermogenesis in cold-exposed Hu lambs. We concluded that Altay lambs rely on liver-mediated shivering and nonshivering thermogenesis by muscle tissue to a greater extent than Hu lambs. Results from this study could provide a theoretical foundation for the breeding and production of cold-resistant lambs.

scholarly journals On the role of subsurface heat conduction in glacier energy-balance modelling

2009 ◽  
Vol 50 (50) ◽  
pp. 16-24 ◽  
Author(s):  
Francesca Pellicciotti ◽  
Marco Carenzo ◽  
Jakob Helbing ◽  
Stefan Rimkus ◽  
Paolo Burlando
Keyword(s):  
Heat Conduction ◽  
Energy Balance ◽  
Shortwave Radiation ◽  
Balance Model ◽  
Glacier Surface ◽  
Central Chile ◽  
Air Temperatures ◽  
Weather Stations ◽  
The Difference

AbstractWe discuss the inclusion of the subsurface heat-conduction flux into the calculation of the energy balance and ablation at the glacier–atmosphere interface. Data from automatic weather stations are used to force an energy-balance model at several locations on alpine glaciers and at one site in the dry Andes of central Chile. The heat-conduction flux is computed using a two-layer scheme, assuming that 36% of the net shortwave radiation is absorbed by the surface layer and that the rest penetrates into the snowpack. We compare simulations conducted with and without subsurface heat flux. Results show that assuming a surface temperature of zero degrees leads to a larger overestimation of melt at the sites in the accumulation area (10.4–13.3%) than in the ablation area (0.5–2.8%), due to lower air temperatures and the presence of snow. The difference between simulations with and without heat conduction is also high at the beginning and end of the ablation season (up to 29% for the first 15 days of the season), when air temperatures are lower and snow covers the glacier surface, while they are of little importance during periods of sustained melt at all the locations investigated.

SEASONAL CHANGES IN THE PHYSIOLOGICAL RESPONSE OF MAN TO AN ACUTE COLD STRESS

1967 ◽  
Vol 45 (1) ◽  
pp. 13-27 ◽  
Author(s):  
F. Girling
Keyword(s):  
Cold Stress ◽  
Heat Production ◽  
Cold Exposure ◽  
Seasonal Changes ◽  
Human Subjects ◽  
Minute Ventilation ◽  
Acute Cold Exposure ◽  
Air Temperatures ◽  
The Individual ◽  
Shivering Thermogenesis

Eight male human subjects, resting supine, and wearing swim trunks only, were exposed to an ambient temperature of 8.5 °C for 1 hour in the first week of each month from February 1964 to January 1965 inclusive. Skin, rectal, and air temperatures were measured with thermistor probes. Percentage oxygen in expired air and minute ventilation were measured, and heat production was calculated by Weir's method. Electrical activity from the muscles of all four limbs was measured to determine shivering response. Control values of resting respiration and heat production were obtained under comfortably warm conditions and showed marked seasonal variation, with minimum values in spring and maximum values in later summer. In the response to acute cold exposure, marked seasonal changes were found also which were superimposed on the seasonal changes in control values. The response to cold exposure indicated maximum acclimatization to cold in the spring and minimum in later summer. These results are discussed in terms of three modes of response to the cold stress: (i) insulative cooling, (ii) shivering thermogenesis, and (iii) nonshivering thermogenesis. The degree of acclimatization and temperature of exposure may determine the individual mode of response.

Shivering and nonshivering thermogenic responses of cold-exposed rats to hypothalamic warming

1975 ◽  
Vol 228 (5) ◽  
pp. 1519-1524 ◽  
Author(s):  
CA Fuller ◽  
BA Horwitz ◽  
JM Horowitz
Keyword(s):  
Oxygen Consumption ◽  
Heat Production ◽  
Neural Control ◽  
Nonshivering Thermogenesis ◽  
Neural Controllers ◽  
Rate Of Oxygen Consumption ◽  
Exposed Animal ◽  
Unanesthetized Animals ◽  
Shivering Thermogenesis ◽  
Rule Out

The concurrent neural control of two thermoregulatory responses, shivering thermogenesis (ST) and nonshivering thermogenesis (NST), was investigated in chronically implanted cold-exposed rats. The effects of heating the preoptic/anterior hypothalamus (POAH) on shivering and on the rate of oxygen consumption (Vo2) were measured in these unanesthetized animals. With ambient temperature maintained constant (at some value between 10 and 16 degrees C), warming the hypothalamus 2-3 degrees C resulted in a significant decrease in Vo2 (Psmaller than 0.001) and an increase in shivering (Psmaller than .01), these responses being reversed on cessation of hypothalamic warming. These results are consistent with the proposal that, in the cold-exposed animal, elevated POAH temperatures directly inhibit NST even though shivering may increase (possibly as a compensation for the decrease in nonshivering heat production). They also rule out the possibility that, in the rat, signals from cutaneous and hypothalamic thermoreceptors are integrated in an indentical manner by the neural controllers for ST and NST.

The role of differential phase contrast in electron microscopy

1978 ◽  
Vol 36 (1) ◽  
pp. 176-177
Author(s):  
E.M. Waddell ◽  
J.N. Chapman ◽  
R.P. Ferrier
Keyword(s):  
Phase Contrast ◽  
Practical Method ◽  
Position Vector ◽  
Differential Phase ◽  
Pure Phase ◽  
Differential Phase Contrast ◽  
The Difference ◽  
Image Position ◽  
First Moment

Dekkers and de Lang (1977) have discussed a practical method of realising differential phase contrast in a STEM. The method involves taking the difference signal from two semi-circular detectors placed symmetrically about the optic axis and subtending the same angle (2α) at the specimen as that of the cone of illumination. Such a system, or an obvious generalisation of it, namely a quadrant detector, has the characteristic of responding to the gradient of the phase of the specimen transmittance. In this paper we shall compare the performance of this type of system with that of a first moment detector (Waddell et al.1977).For a first moment detector the response function R(k) is of the form R(k) = ck where c is a constant, k is a position vector in the detector plane and the vector nature of R(k)indicates that two signals are produced. This type of system would produce an image signal given bywhere the specimen transmittance is given by a (r) exp (iϕ (r), r is a position vector in object space, ro the position of the probe, ⊛ represents a convolution integral and it has been assumed that we have a coherent probe, with a complex disturbance of the form b(r-ro) exp (iζ (r-ro)). Thus the image signal for a pure phase object imaged in a STEM using a first moment detector is b2 ⊛ ▽ø. Note that this puts no restrictions on the magnitude of the variation of the phase function, but does assume an infinite detector.

On the Role of Transferrin in 67Ga Uptake by Tumor Cells

1988 ◽  
Vol 27 (04) ◽  
pp. 151-153
Author(s):  
P. Thouvenot ◽  
F. Brunotte ◽  
J. Robert ◽  
L. J. Anghileri
Keyword(s):  
Specific Binding ◽  
Subcellular Fractionation ◽  
Animal Blood ◽  
Tumor Bearing ◽  
Cell Structures ◽  
The Difference ◽  
Sarcoma Cells ◽  
In Vitro Uptake

In vitro uptake of 67Ga-citrate and 59Fe-citrate by DS sarcoma cells in the presence of tumor-bearing animal blood plasma showed a dramatic inhibition of both 67Ga and 59Fe uptakes: about ii/io of 67Ga and 1/5o of the 59Fe are taken up by the cells. Subcellular fractionation appears to indicate no specific binding to cell structures, and the difference of binding seems to be related to the transferrin chelation and transmembrane transport differences

REFLECTION COEFFICIENT OF AN ELECTROMAGNETIC WAVE IN CONDUCTIVE MEDIA

2018 ◽  
pp. 100-106
Author(s):  
M. S. Sudakova ◽  
M. L. Vladov ◽  
M. R. Sadurtdinov
Keyword(s):  
Reflection Coefficient ◽  
Ground Penetrating Radar ◽  
Electromagnetic Waves ◽  
Water Contamination ◽  
Survey Design ◽  
Direct And Inverse Problems ◽  
The Difference ◽  
Ground Penetrating ◽  
Ideal Dielectric

Within the ground penetrating radar bandwidth the medium is considered to be an ideal dielectric, which is not always true. Electromagnetic waves reflection coefficient conductivity dependence showed a significant role of the difference in conductivity in reflection strength. It was confirmed by physical modeling. Conductivity of geological media should be taken into account when solving direct and inverse problems, survey design planning, etc. Ground penetrating radar can be used to solve the problem of mapping of halocline or determine water contamination.

Speculative Realism and Science Fiction

2017 ◽  
Author(s):  
Brian Willems
Keyword(s):  
Science Fiction ◽  
Identity Formation ◽  
Cormac Mccarthy ◽  
Doris Lessing ◽  
Speculative Realism ◽  
Neil Gaiman ◽  
The World ◽  
The Difference ◽  
Quentin Meillassoux

A human-centred approach to the environment is leading to ecological collapse. One of the ways that speculative realism challenges anthropomorphism is by taking non-human things to be as valid objects of investivation as humans, allowing a more responsible and truthful view of the world to take place. Brian Willems uses a range of science fiction literature that questions anthropomorphism both to develop and challenge this philosophical position. He looks at how nonsense and sense exist together in science fiction, the way in which language is not a guarantee of personhood, the role of vision in relation to identity formation, the difference between metamorphosis and modulation, representations of non-human deaths and the function of plasticity within the Anthropocene. Willems considers the works of Cormac McCarthy, Paolo Bacigalupi, Neil Gaiman, China Miéville, Doris Lessing and Kim Stanley Robinson are considered alongside some of the main figures of speculative materialism including Graham Harman, Quentin Meillassoux and Jane Bennett.

On the Use of Quantum Thermal Bath in Unimolecular Fragmentation Simulations

2019 ◽  
Author(s):  
Riccardo Spezia ◽  
Hichem Dammak
Keyword(s):  
Degrees Of Freedom ◽  
Molecular Simulations ◽  
Zero Point ◽  
Thermal Bath ◽  
Unimolecular Dissociation ◽  
Point Energy ◽  
Rotational Degrees Of Freedom ◽  
The Difference ◽  
Nuclear Effects

<div> <div> <div> <p>In the present work we have investigated the possibility of using the Quantum Thermal Bath (QTB) method in molecular simulations of unimolecular dissociation processes. Notably, QTB is aimed in introducing quantum nuclear effects with a com- putational time which is basically the same as in newtonian simulations. At this end we have considered the model fragmentation of CH4 for which an analytical function is present in the literature. Moreover, based on the same model a microcanonical algorithm which monitor zero-point energy of products, and eventually modifies tra- jectories, was recently proposed. We have thus compared classical and quantum rate constant with these different models. QTB seems to correctly reproduce some quantum features, in particular the difference between classical and quantum activation energies, making it a promising method to study unimolecular fragmentation of much complex systems with molecular simulations. The role of QTB thermostat on rotational degrees of freedom is also analyzed and discussed. </p> </div> </div> </div>

«Имперский синдром»: концепция османского халифата на Ближнем Востоке и в Южной Азии (первая четверть XX в.)

2019 ◽  
Author(s):  
S.A. Kirillina ◽  
A.L. Safronova ◽  
V.V. Orlov
Keyword(s):  
Middle East ◽  
South Asia ◽  
South Asian ◽  
Political Role ◽  
The Social ◽  
The Difference ◽  
Aspect Interaction ◽  
Muhammad Rashid Rida ◽  
Political Actions

Аннотация В статье изучены общие и специфические черты идейных воззрений, пропагандистской риторики и политических действий представителей халифатистского движения на Ближнем Востоке и в Южной Азии. В ретроспективном ключе прослеживается эволюция представлений о сущности и необходимости возрождения института халифата в трудах исламских идеологов, реформаторов и политиков Джамал ад-Дина ал-Афгани, Абд ар-Рахмана ал-Кавакиби, Мухаммада Рашида Риды, Абул Калама Азада. Внимание авторов сосредоточено на общественно-политических дискуссиях 2030-х годов XX столетия, а также на повестке дня халифатистских конгрессов и конференций этого периода. На них вырабатывались первые представления современников о пост-османском формате мусульманского единства и идейно-политической роли будущего халифата. Авторы демонстрируют различие между моделями реакции мусульман Ближнего Востока и Южной Азии на упразднение османского халифата республиканским руководством Турции. Установлена многоаспектная взаимосвязь между халифатистскими ценностями, проосманскими настроениями и формами самоотождествления, которые сложились в арабских и южноазиатских обществах. Отдельно намечено соотношение между подъемом халифатистских настроений и радикализацией антиколониальных действий мусульман Индостана.Abstract The article deals with analysis of common and specific features of ideas, propaganda, rhetoric and political actions taken by representatives of the movement for defense of the Caliphate in the Middle East and South Asia. The retrospection showing the transformation of conception of the Caliphate and the necessity of its revival in the works of eminent ideologists and politicians of the Muslim world Jamal al-Din al-Afghani, Abd al-Rahman al-Kawakibi, Muhammad Rashid Rida and Abul Kalam Azad, is also given in the article. The authors also focus on the social and political discussions of the 1920s 1930s, as well as on the agenda of Caliphatist congresses and conferences of this period. They helped to elaborate the early representations of post-Ottoman pattern of the Muslim unity and the ideological and political role of the future Caliphate. The authors demonstrate the difference between the forms of reaction of Muslims in the Middle East and South Asia to the repudiation of the Caliphate by the Republican leaders of Turkey. The article establishes a multi-aspect interaction between the Caliphatist values and forms of self-identification, emerged in Arab and South Asian societies. The correlation between the rise of Caliphatist attitudes and radicalization of anti-colonial actions of South Asian Muslims is also outlined.

Seasonal trends in the stable isotopic composition of snow and meltwater runoff in a subarctic catchment at Okstindan, Norway

2004 ◽  
Vol 35 (2) ◽  
pp. 119-137 ◽  
Author(s):  
S.D. Gurney ◽  
D.S.L. Lawrence
Keyword(s):  
Isotopic Composition ◽  
Mean Value ◽  
Mean Values ◽  
Stable Isotopic Composition ◽  
Meltwater Runoff ◽  
Stable Isotopic ◽  
The Mean ◽  
The Difference ◽  
Δ18o And Δd

Seasonal variations in the stable isotopic composition of snow and meltwater were investigated in a sub-arctic, mountainous, but non-glacial, catchment at Okstindan in northern Norway based on analyses of δ18O and δD. Samples were collected during four field periods (August 1998; April 1999; June 1999 and August 1999) at three sites lying on an altitudinal transect (740–970 m a.s.l.). Snowpack data display an increase in the mean values of δ18O (increasing from a mean value of −13.51 to −11.49‰ between April and August), as well as a decrease in variability through the melt period. Comparison with a regional meteoric water line indicates that the slope of the δ18O–δD line for the snowpacks decreases over the same period, dropping from 7.49 to approximately 6.2.This change points to the role of evaporation in snowpack ablation and is confirmed by the vertical profile of deuterium excess. Snowpack seepage data, although limited, also suggest reduced values of δD, as might be associated with local evaporation during meltwater generation. In general, meltwaters were depleted in δ18O relative to the source snowpack at the peak of the melt (June), but later in the year (August) the difference between the two was not statistically significant. The diurnal pattern of isotopic composition indicates that the most depleted meltwaters coincide with the peak in temperature and, hence, meltwater production.

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