Effects of weather and parasitic insects on behavior and group dynamics of caribou of the Delta Herd, Alaska

1997 ◽  
Vol 75 (10) ◽  
pp. 1659-1670 ◽  
Author(s):  
Frank M. Mörschel ◽  
David R. Klein
Keyword(s):  
High Temperature ◽  
Ambient Temperature ◽  
Group Dynamics ◽  
Rangifer Tarandus ◽  
High Ambient Temperature ◽  
Alaska Range ◽  
North Central ◽  
Insect Abundance ◽  
Rates Of Change ◽  
The North

The influence of weather and parasitic insects on the behavior and group dynamics of caribou (Rangifer tarandus) of the Delta Herd in the north-central Alaska Range was investigated. Data on weather, insect abundance, and caribou behavior were collected during summer in 1994 and 1995. High ambient temperature had the greatest influence on activity budgets and rates of change in activity of caribou. In the insect season, rates of activity changes and standing increased and feeding decreased with high temperature. Rates of activity changes and moving increased and feeding decreased with high temperature, even in the absence of insects. Caribou decreased feeding and increased standing in the presence of oestrid flies, and increased the rate of activity changes in the presence of mosquitoes and oestrid flies. Weather, especially high temperature, and parasitic insects, particularly oestrid flies, affected caribou mainly by decreasing foraging opportunities and increasing energy-expending activities.

X-Ray and Optical Data for a Rare Earth–Poor Eudialyte from the North–Central Alaska Range

1990 ◽  
Vol 5 (2) ◽  
pp. 89-92 ◽  
Author(s):  
Neil E. Johnson ◽  
Mickey E. Gunter ◽  
Diana N. Solie ◽  
Charles R. Knowles
Keyword(s):  
Rare Earth ◽  
Powder Diffraction ◽  
Weight Percent ◽  
Optical Data ◽  
Alaska Range ◽  
North Central ◽  
X Ray ◽  
The North ◽  
Cell Dimensions ◽  
Unit Cell Dimensions

AbstractPowder X-ray and optical data have been recorded for a sample of exceptionally rare earth-poor eudialyte (Na12(Ca, REE)6(Fe2+,Mn,Mg)3Zr3(Zr,Nb)x[Si9O27−y(OH)y]2[Si3O9]2(C1,F)z, with x = 0. 1–0.9, y = 1–3 and z = 0.7–1.4) from a pegmatitic vein associated with the peralkaline Windy Fork granite in the north–central Alaska range. The eudialyte is uniaxial positive with ω= 1.6062(2), ε= 1.6138 (3) and microprobe analyses indicate that the sum of REE + Yis less than 0.1 weight percent. Refined unit cell dimensions are: a = 14.2572(4), c = 30.1338(27), Dx= 2.67, F30= 128 (0.006, 42), M20= 76. An indexed powder diffraction pattern is given.

scholarly journals VIL1, a Polycomb-associated protein, modulates high ambient temperature response via H3K27me3 and H2A.Z in Arabidopsis thaliana

2020 ◽  
Author(s):  
Yogendra Bordiya ◽  
Junghyun Kim ◽  
Yanpeng Xi ◽  
Dong-Hwan Kim ◽  
Youngjae Pyo ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
High Temperature ◽  
Ambient Temperature ◽  
Epigenetic Regulation ◽  
Temperature Response ◽  
High Ambient Temperature ◽  
Rna Seq ◽  
Wild Type ◽  
Phd Finger ◽  
Finger Protein

AbstractAdapting to the everchanging environment is key to a successful life for an organism. Eukaryotes reprogram their transcriptome in order to adapt to an unfavorable environment. To achieve this reprogramming, plants and animals employ multiple responses including epigenetic regulation. In the search for mutations compromised in high ambient temperature response, we found that VIL1, a PHD finger protein displays aberrant development at high temperature. RNA-seq analysis shows that vil1 fails to downregulate heat suppressed genes. H2A.Z ChIP-seq showed that unlike wild type, vil1 fails to evict H2A.Z from heat responsive genes. We also found that vil1 suppresses constitutive thermo-morphogenic phenotype of arp6. Supporting this phenotype, RNA-seq analysis revealed that constitutive heat responsive transcriptome of arp6 reverted back to the wild-type levels in arp6vil1. This observation suggests an antagonistic relationship between VIL1 and ARP6. We found that this antagonism can be explained in part by interaction between H3K27me3 and H2A.Z.

Foetal stunting in sheep: 2. The effects of high ambient temperature during gestation on wool follicle development in the foetal lamb

1976 ◽  
Vol 86 (3) ◽  
pp. 581-585 ◽  
Author(s):  
G. A. Cartwright ◽  
C. J. Thwaites
Keyword(s):  
High Temperature ◽  
Ambient Temperature ◽  
Feed Intake ◽  
High Ambient Temperature ◽  
Follicle Development ◽  
Apparent Effect ◽  
New Born ◽  
Wool Growth ◽  
Wool Follicle ◽  
Foetal Lamb

SummaryHotroom treatment of ewes during the last two-thirds of gestation resulted in the birth of lambs which were significantly lighter than lambs born to nutritionallydeprived ewes. Neither high temperature nor undernutrition had significant effect on the density of either primary or immature secondary wool follicles, but the total number of mature secondary follicles tended to decline in the lambs from unheated ewes as the level of nutrition declined, and was significantly reduced by a further 30 % in the hotroom group.In a second experiment, heated and unheated ewes fed to appetite were compared with unheated ewes pair-fed to the hotroom level of feed intake. High temperature had no apparent effect on maternal wool growth, but did reduce total wool follicle number in new-born lambs by approximately 50%. This effect was most marked with respect to mature secondary follicles (only 18% of unheated mean), less so in immature secondaries (56% of unheated mean), and barely discernible amongst primary follicles (93% of unheated mean). None of the differences in follicle numbers between the two unheated groups was significant.The results suggest that the effects of high temperature on wool follicle development in the sheep foetus are akin to those of extreme undernutrition.

Bats in riverine forests and woodlands: a latitudinal transect in southern Africa

1996 ◽  
Vol 74 (2) ◽  
pp. 312-322 ◽  
Author(s):  
I. L. Rautenbach ◽  
M. J. Whiting ◽  
M. B. Fenton
Keyword(s):  
Activity Patterns ◽  
Species Abundance ◽  
North Central ◽  
Insect Abundance ◽  
Bat Activity ◽  
The North ◽  
Latitudinal Transect ◽  
Riverine Habitats ◽  
Dry Woodland ◽  
Bat Diversity

Using captures in mist nets and monitoring echolocation calls, we quantified bat distribution and activity and measured insect abundance as numbers of insects attracted to black lights at 15-min intervals. These data were collected simultaneously at pairs of sites in riverine and dry woodland savannah along a transect of ca. 350 km from north to south in the Kruger National Park, South Africa. The sites were situated in the north, central, and south of the park and data were collected in January 1993. Our study involved 18 sites, three pairs each in the areas of the Luvuvhu, Letaba, and Sabie rivers. Half of the sites were in riverine woodland, the others in dry woodland. No statistical association exists between bat captures and either bat activity or insect abundance. Bat activity, however, was related significantly to insect abundance. Although bats were significantly more abundant (captures) in riverine habitats than in dry woodland savannah, comparisons of bat diversity and evenness (rarefaction curves, species abundance curves, and Whittaker plots) showed no differences between these habitats. The data neither demonstrate a decline in bat diversity away from the equator nor suggest specific bat communities associated with riverine habitats. The data do demonstrate the important influence of insects on the activity patterns of insectivorous bats.

scholarly journals Effects of High Ambient Temperature and Bypass Protein Supplementation on Performance of Crossbred Lambs

2019 ◽  
Vol 2 (1) ◽  
pp. 78
Author(s):  
Dahlanuddin Dahlanuddin ◽  
C.J. Thwaites ◽  
J.V. Nolan
Keyword(s):  
Weight Gain ◽  
High Temperature ◽  
Ambient Temperature ◽  
Cottonseed Meal ◽  
Dry Matter ◽  
Control Diet ◽  
Live Weight ◽  
High Ambient Temperature ◽  
Dry Matter Intake ◽  
Ad Libitum

The objective of this experiment was to study the effect of dietary supplementation with a source ofbypass protein (cottonseed meal, CSM) on the performance of growing crossbred wethers fed lowdigestibility roughage at high ambient temperature. Sixteen unshorn Border Leicester x Merino lambsaged 6 months and weighing 24.90.37 kg were allocated into a 2x2 factorial design (2 diets and 2ambient temperatures). Each group was fed either wheaten chaff + 2% urea ad libitum or wheaten chaff +1% urea ad libitum + 100g/d cottonseed meal. The results show that respiration rate and rectal temperaturewere significantly affected by ambient temperature (P<0.01), but not by diet. Total dry matter intake wassignificantly higher (P<0.01) at lower temperature than at high temperature, and significantly higher(P=0.04) on the supplemented diet than on the control diet. Water intake tended (P=0.06) to be higher onthe CSM+ diet than on the control diet, and was significantly at greater (P<0.01) high ambient temperaturethan at low temperature. The concentration of NH3-N in the rumen fluid (ranged from 310±17 to 413±20mg N/L) did not differ significantly either between diets or ambient temperatures. Blood plasma ureanitrogen concentration was significantly higher in sheep on the control diet than in those on thesupplemented diet, and at low than high temperature. The organic matter digestibility was not significantlyaffected by temperature and diet. The rate of live weight gain was significantly (P<0.01) reduced by highambient temperature and the interaction between diet and temperature was significant (P<0.01). At lowtemperature, lambs on the supplemented diet grew significantly faster than those on the control diet, butnot at high temperature. In conclusion, high ambient temperature increases respiration rate, rectaltemperature and water intake but reduces dry matter intake and live weight gain. Supplementation with100 g/d of cottonseed meal could not outweigh the depressing effects of constant high ambienttemperature and humidity imposed in this experiment.

scholarly journals A Step Toward High Temperature Intelligent Power Modules Using 1.5kV SiC-BJT

2010 ◽  
Vol 645-648 ◽  
pp. 1155-1158 ◽  
Author(s):  
Dominique Tournier ◽  
Pascal Bevilacqua ◽  
Pierre Brosselard ◽  
Dominique Planson
Keyword(s):  
High Temperature ◽  
Ambient Temperature ◽  
Preliminary Analysis ◽  
High Efficiency ◽  
High Ambient Temperature ◽  
Large Power ◽  
Turn On ◽  
Power Modules ◽  
Functional Blocks ◽  
Looking Back

Looking back to the development of inverters using SiC switches, it appears that SiC devices do not behave like their silicon counterparts. Their ability to operate at high temperature makes them attractive. Developing drivers suitable for 200 °C operation is not straightforward. In a perspective of high integration and large power density, it is wise to consider a monolithic integration of the driver parts for the sake of reliability. Silicon is not suitable for high ambient temperature; silicon-oninsulator offers better performances and presents industrial perspectives. The paper focuses on a SiC BJT driver: it processes logical orders from outside, drives adequately the BJT to turn it either on or off, monitors the turn-off and turn-on state of the device, and acts accordingly to prevent failure. SiC BJT imposes specific performances different from the well known ones of SiC JFET or MOSFET. The paper addresses a preliminary analysis of a SOI driver, anticipating the behavior of SiC-BJT and the change in behavior at high temperature. A discret driver has been designed and fabricated. Elementary functional blocks have been validated, and a BJT converter successfully operated at high temperature with high efficiency ( = 88%).

Loss of potential young in the ewe due to high ambient temperature

1961 ◽  
Vol 16 (2) ◽  
pp. 253-256 ◽  
Author(s):  
C. W. Alliston ◽  
Gene E. Egli ◽  
L. C. Ulberg
Keyword(s):  
High Temperature ◽  
Embryonic Development ◽  
Ambient Temperature ◽  
Reproductive Performance ◽  
Fertilization Rate ◽  
High Ambient Temperature ◽  
Summer Temperatures ◽  
Higher Temperature

Embryonic development and other measures of reproductive performance were compared for 3 years in sheep maintained at 65°F, at prevailing summer temperatures, and at a constant, high temperature (92°F). The concentration and motility of the sperm and the fertility of the semen from control rams declined during periods of high temperature. Fertilization rate was lowered when rams were exposed to high prevailing atmospheric temperatures or ewes to a constant high temperature. A higher percentage of morphologically abnormal ova was recovered from ewes subjected to the higher temperatures. The stages of embryonic development indicated that, in ewes at the higher temperature, a loss of potential young occurs by a cessation of development during cleavage. Submitted on May 6, 1960

The energy and protein metabolism of pigs growing at a high ambient temperature

1973 ◽  
Vol 16 (2) ◽  
pp. 117-133 ◽  
Author(s):  
C. W. Holmes
Keyword(s):  
High Temperature ◽  
Ambient Temperature ◽  
Nitrogen Retention ◽  
Live Weight ◽  
High Ambient Temperature ◽  
Fat Percentage ◽  
Protein Retention ◽  
Temperature Heat ◽  
Low Levels ◽  
Urinary Nitrogen

SUMMARY1. The experiment was designed to investigate the effect of growth at a high ambient temperature, 33–35°C, on the protein and energy metabolism of pigs, compared with 25°C. The high temperature caused an increase in rectal temperature of 1·4° to 1·7°C. The animals were given two low levels of feeding while growing between 25 and 70 kg live weight; energy and nitrogen retention were measured periodically.2. The apparent digestibilities of the dietary dry matter and energy were decreased and urinary nitrogen losses were increased at the high temperature. Heat production was increased at the high temperature, by between 2% and 10%, the effect becoming more pronounced during the course of the experiment. Retention of energy and nitrogen was reduced at the high temperature.3. The net efficiency of utilization of metabolized energy above maintenance was between 63% and 67%, and was not significantly affected by live weight or temperature. The results suggested that maintenance requirement was increased at the high temperature.4. Analyses of sample joints indicated that the high temperature caused an increase in fat percentage only at the higher level of feeding; this result agreed with fat and protein retention calculated from the balances.

Canyon Creek: A Late Pleistocene Vertebrate Locality in Interior Alaska

1981 ◽  
Vol 16 (2) ◽  
pp. 167-180 ◽  
Author(s):  
Florence R. Weber ◽  
Thomas D. Hamilton ◽  
David M. Hopkins ◽  
Charles A. Repenning ◽  
Herbert Haas
Keyword(s):  
Late Holocene ◽  
Mammuthus Primigenius ◽  
Alaska Range ◽  
North Central ◽  
The North ◽  
Subsequent Period ◽  
Eolian Sand ◽  
Wild Ass ◽  
Fossil Bones ◽  
Woolly Mammoth

AbstractThe Canyon Creek vertebrate-fossil locality is an extensive road cut near Fairbanks that exposes sediments that range in age from early Wisconsin to late Holocene. Tanana River gravel at the base of the section evidently formed during the Delta Glaciation of the north-central Alaska Range. Younger layers and lenses of fluvial sand are interbedded with arkosic gravel from Canyon Creek that contains tephra as well as fossil bones of an interstadial fauna about 40,000 years old. Solifluction deposits containing ventifacts, wedge casts, and rodent burrows formed during a subsequent period of periglacial activity that took place during the maximum phase of Donnelly Glaciation about 25,000–17,000 years ago. Overlying sheets of eolian sand are separated by a 9500-year-old paleosol that may correlate with a phase of early Holocene spruce expansion through central Alaska. The Pleistocene fauna from Canyon Creek consists of rodents (indicated by burrows), Mammuthus primigenius (woolly mammoth), Equus lambei (Yukon wild ass), Camelops hesternus (western camel), Bison sp. cf. B. crassicornis (large-horned bison), Ovis sp. cf.O. dalli (mountain sheep), Canis sp. cf. C. lupus (wolf), Lepus sp. cf. L. othus or L. arcticus (tundra hare), and Rangifer sp. (caribou). This assemblage suggests an open landscape in which trees and tall shrubs were either absent or confined to sheltered and moist sites. Camelops evidently was present in eastern Beringia during the middle Wisconsin interstadial interval but may have disappeared during the following glacial episode. The stratigraphic section at Canyon Creek appears to demonstrate that the Delta Glaciation of the north-central Alaska Range is at least in part of early Wisconsin age and was separated from the succeeding Donnelly Glaciation by an interstadial rather than interglacial episode.

Sign in / Sign up

Export Citation Format

Share Document