Winter frost feathers on a conservatory roof following a cold night

Weather ◽  
2020 ◽  
Vol 75 (1) ◽  
Keyword(s):  
1987 ◽  
Vol 253 (1) ◽  
pp. R39-R45 ◽  
Author(s):  
S. Oufara ◽  
H. Barre ◽  
J. L. Rouanet ◽  
J. Chatonnet

To explain tolerance of heat and cold in gerbils (Gerbillus campestris) in their natural environment, a comparative study was made of thermoregulatory reactions in these animals and white mice (Mus musculus) of the same body mass exposed for 2-3 h to ambient temperatures (Ta) ranging from -23 to 40 degrees C. Metabolic rate (MR), evaporative heat loss (EHL), colonic temperature (Tb), and electromyographic activity (EMG) were measured. Nonshivering thermogenesis (NST) was also evaluated from the increase in MR after norepinephrine injection. In gerbils, tolerance of cold was higher than in mice; there was no fall in Tb in cold-acclimated (CA) and control (TN) gerbils after 3 h of exposure at -20 and -10 degrees C Ta, respectively; peak MR (PMR) reached five to six times resting MR (RMR) in gerbils and four to five times in mice. In gerbils, RMR was 35% below that of mice. In TN gerbils, EHL did not increase before 38 degrees C Ta; EHL increased at 26 degrees C in mice. In both animals, cold acclimation increased cold tolerance, PMR, RMR, and NST. Low RMR, high Tb, and mainly burrowing habits preserve gerbils from overheating and save water in hot and arid environments, and a conspicuous tolerance of cold allows them to live and forage in the wild during the cold night.


2010 ◽  
Vol 56 (197) ◽  
pp. 384-394 ◽  
Author(s):  
Natalya Reznichenko ◽  
Tim Davies ◽  
James Shulmeister ◽  
Mauri McSaveney

AbstractHere we report a laboratory study of the effects of debris thickness, diurnally cyclic radiation and rainfall on melt rates beneath rock-avalanche debris and sand (representing typical highly permeable supraglacial debris). Under continuous, steady-state radiation, sand cover >50 mm thick delays the onset of ice-surface melting by >12 hours, but subsequent melting matches melt rates of a bare ice surface. Only when diurnal cycles of radiation are imposed does the debris reduce the longterm rate of ice melt beneath it. This is because debris >50 mm thick never reaches a steady-state heat flux, and heat acquired during the light part of the cycle is partially dissipated to the atmosphere during the nocturnal part of the cycle, thereby continuously reducing total heat flux to the ice surface underneath. The thicker the debris, the greater this effect. Rain advects heat from high-permeability supraglacial debris to the ice surface, thereby increasing ablation where thin, highly porous material covers the ice. In contrast, low-permeability rock-avalanche material slows water percolation, and heat transfer through the debris can cease when interstitial water freezes during the cold/night part of the cycle. This frozen interstitial water blocks heat advection to the ice–debris contact during the warm/day part of the cycle, thereby reducing overall ablation. The presence of metre-deep rock-avalanche debris over much of the ablation zone of a glacier can significantly affect the mass balance, and thus the motion, of a glacier. The length and thermal intensity of the diurnal cycle are important controls on ablation, and thus both geographical location and altitude significantly affect the impact of debris on glacial melting rates; the effect of debris cover is magnified at high altitude and in lower latitudes.


1990 ◽  
Vol 70 (1) ◽  
pp. 363-368
Author(s):  
SERGE GAGNON ◽  
BLANCHE DANSEREAU

To achieve more rapid adaptation of plants grown under a constant cold night temperature regime, rooted poinsettia (Euphorbia pulcherrima Willd ex. Klotzsch ’Annette Hegg Dark Red’) cuttings were given one of several cold pretreatments (TPF): either 17/13 °C or 13 °C for 5, 10, or 15 d. The influence of these TPF treatments was compared with that of control plants where the night temperature was 17 °C. There was no significant difference for the number of days to the first visible flower buds and to anthesis, for the number of flowering stems and bracts formed, for leaf area and aerial dry weight. However, the TPF treatment of 17/13 °C given for 15 d caused a significant increase in bract area, and of average flower head diameter compared to those plants given a TPF treatment of 13 °C for the same length of time.Key words: Euphorbia pulcherrima, night temperature, split night temperature, pretreatment


2021 ◽  
Vol 257 ◽  
pp. 03007
Author(s):  
Li Xirong ◽  
Yang Dong ◽  
Yi Wei

Using the daily temperature data from meteorological stations in Yunnan province and Guizhou province and Guizhou province from 2000 to 2019, NCEP/NCAR re-analyzed the data on a daily basis, and analyzed the temporal and spatial characteristics of extreme temperature events in the study area. Research shows that the extreme temperature in Yunnan province and Guizhou province region is warming; the extreme temperature index is different in spatial tendency, and all have abrupt changes; the maximum monthly maximum temperature and the heat persistence index will continue to increase in the future, the number of cold night days and the cold persistence index are on a strong and continuous decreasing trend.


2021 ◽  
Vol 9 ◽  
Author(s):  
Enrique Doblas-Miranda

All the animals living below our feet are not still. They can move (to a lot of places because the soil is a 3D space) and to change (for example, from a cocoon to an active state). Therefore, the same soil below a given piece of field may not contain the same living communities in winter as in summer, or even during a sunny day compared to a cold night. For example, research on soil beetle larvae showed seasonal vertical movements, as the larvae searched for better living conditions. Moreover, the soil varies a lot during its formation, and consequently its inhabitants also change. In the case of oribatids, a minuscule but diverse group of soil mites, scientists observed changes in the community over dozen to hundreds of years! Many studies showed a basic but powerful principle: ecosystems are not still photographs, but instead are constantly changing environments.


2020 ◽  
Author(s):  
Misganaw Genet Mola ◽  
Yibelu Yitayih Hailie ◽  
Hailu Birhanie Terefe ◽  
Reta Yeshambel Kessete

Abstract Background: There is an ancient history that human beings are familiar with use of animals and plants for food, cloth, medicine, etc. In Ethiopia, many ethnic communities which are dispersed all over the country has been totally dependent on local traditional medicinal system for their health care. Thus, the aim of this study was to take an ethnozoological field survey among different ethnic groups that live in South Achefer district. In order to document the ethno zoological information about animal and their parts/ products prevalent among the people in South Achefer district, a study was carried out from September, 2019 to January, 2020.Methods: Data was collected through questionnaire, focus group discussion and semi-structured questionnaire with 64 purposively selected respondents. Result: Ethnozoological data was recorded local name of the animals, animal products used, mode of preparation and administration Based on the ethno zoological survey, a total of 30 animal species were used in 42 different medicinal purposes including cold, night blindness, cough, paralysis and rheumatism and for other religious/and spiritual purposes. Based on the ethno zoological survey, 11 mammals, 7 birds, 4 reptile, 5 arthropods, 2 fish, 1 annelids are used in traditional zootherauptics in the study area. Furthermore, the milk of goat used to relieved cough has the highest FL (92%) and elephant teeth has the lowest FL (22%) used to treat bad spirit.Discussion: The results showed that ethno zoological practices have been an important alternative medicinal practice for the people residing in the study area. So, there is an urgent need to properly document to keep a record of the ethno zoological knowledge of the area. It is hoped that this information will be useful for further research in the field of ethno zoology, ethno pharmacology and conservation point of view.


PEDIATRICS ◽  
1989 ◽  
Vol 84 (4) ◽  
pp. 716-716
Author(s):  
T. E. C.

A commonly held view of mid-nineteenth century physicians, especially in New England, was that young schoolgirls should not be worked too hard and too long at their studies. The editorial below from a highly-respected medical journal is evidence of this unwarranted belief. Every effort in the school now is to cultivate their minds at the expense of their bodies. They consequently have a sickly life, if perchance it is not cut off in early girlhood; they make poor mothers, are unable to nurse their children in many instances with a tendency to some of the most distressing complaints, and disease is propagated to their children. Much of this arises from the popular mistake that young misses must study algebra, chemistry, scientific botany, Latin, and perhaps Greek and Hebrew, by the time they are fifteen, in order to become ladies. They have no frolicking girlhood—because it is plebeian to romp out of doors with freedom, as nature intended in order to strengthen and perfect their delicate organization. A knowledge of domestic economy is decidely vulgar, and belongs to poor kitchen girls, whose red cheeks, round arms, splendid busts and fine health are perfectly contemptible. There is a kind of imagined gentility in always being under the care of a doctor, and jaunting through the country in pursuit of air, water, or expensive medical advice. Physicians deplore this wretched system, without being able to awaken public sentiment to its destructive character. Teachers are also aware of it, and exert themselves at times to counteract the evils which their every-day lessons exert on the frail, delicate pupils under their charge; but, alas, the poison and antidote are taken at once, and they exhibit the effects of their bad treatment, aided by silk hose in January, thin shoes, the impure atmosphere of crowded rooms and cold night air. Parents are the persons to blame and not the instructors of their children. Young girls are put to school too early and worked too hard and too long at their studies. More active play and fewer books, pudding-making in the place of algebraical equations, with a free exercise of their feet, which were actually designed for walking, would produce a race of women in our midst, such as cannot now be found, in regard to figure, capacity and beauty. What father has the moral courage to set the example, by allowing his daughters to become the angelic creatures they were designed to be, buoyant with spirit, vigor and health, fit companions of man, and the glory of an advanced civilization? Let them gambol in the open air, and, when indoors, act out the governing instincts of their nature in manufacturing rag dolls, till by means of bodily health and vigor, a foundation is laid for intellectual pursuits, and then and not before, may they with safety begin to be exercised in abstract, educational studies.


2021 ◽  
Vol 13 (1) ◽  
pp. 378
Author(s):  
Denisa Valachova ◽  
Andrea Badurova ◽  
Iveta Skotnicova

Lightweight timber-based structures are an increasingly common part of envelopes of new buildings due to increasing requirements for their energy performance. In addition, due to the fact that wood is a sustainable material, it can be assumed that the share of these structures in civil engineering will continue to increase. The subject of this article is the thermal analysis of timber-based lightweight structures under winter conditions to expand information about thermal processes in these structures. This article deals with the lightweight timber-based external wall structures with a ventilated facade and a double-skin roof structure. Experimental temperature measurements inside the structures and ventilated air gaps are used to perform the thermal analysis. By comparing experimental and theoretical data obtained by performing numerical simulation, it was shown that for achieving an ideal match of numerical simulations and measured physical properties it is necessary to take into account not only external temperatures affecting these structures, but also other factors such as solar radiation and heat emission into the cold night sky. In the case of the external walls with ventilated facade, the benefit of a ventilated air gap has been demonstrated in relation to smaller temperature fluctuations that affect the structures.


2012 ◽  
Vol 12 (5) ◽  
pp. 1671-1691 ◽  
Author(s):  
C. Andrade ◽  
S. M. Leite ◽  
J. A. Santos

Abstract. As temperature extremes have a deep impact on environment, hydrology, agriculture, society and economy, the analysis of the mechanisms underlying their occurrence, including their relationships with the large-scale atmospheric circulation, is particularly pertinent and is discussed here for Europe and in the period 1961–2010 (50 yr). For this aim, a canonical correlation analysis, coupled with a principal component analysis (BPCCA), is applied between the monthly mean sea level pressure fields, defined within a large Euro-Atlantic sector, and the monthly occurrences of two temperature extreme indices (TN10p – cold nights and TX90p – warm days) in Europe. Each co-variability mode represents a large-scale forcing on the occurrence of temperature extremes. North Atlantic Oscillation-like patterns and strong anomalies in the atmospheric flow westwards of the British Isles are leading couplings between large-scale atmospheric circulation and winter, spring and autumn occurrences of both cold nights and warm days in Europe. Although summer couplings depict lower coherence between warm and cold events, important atmospheric anomalies are key driving mechanisms. For a better characterization of the extremes, the main features of the statistical distributions of the absolute minima (TNN) and maxima (TXX) are also examined for each season. Furthermore, statistically significant downward (upward) trends are detected in the cold night (warm day) occurrences over the period 1961–2010 throughout Europe, particularly in summer, which is in clear agreement with the overall warming.


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