Postnatal development of thermoregulation in the semiaquatic muskrat (Ondatra zibethicus)

1999 ◽  
Vol 77 (10) ◽  
pp. 1521-1529 ◽  
Author(s):  
Robert A MacArthur ◽  
Murray M Humphries
Keyword(s):  
Rapid Development ◽  
Developmental Changes ◽  
Morphological Development ◽  
Body Temperatures ◽  
Ondatra Zibethicus ◽  
Thermoregulatory Behavior ◽  
Adult Body ◽  
Rate Of Oxygen Consumption ◽  
Microtine Rodent ◽  
The Mean

Developmental changes in thermoregulatory ability were followed in 1- to 34-d-old muskrats (Ondatra zibethicus) tested individually and in groups composed of 5 littermates. During their first 10-11 d of life, 20- to 60-g nestlings displayed limited thermogenic ability and could not maintain a stable body temperatures (Tb) during 2 h exposure to an air temperature (Ta) of 10 or 25°C. At 25°C, a Ta approximating nest temperatures in the field, nestlings were homeothermic at ca. 10-11 d of age, when they were fully furred, capable of limited swimming, and within 1-2 d of opening their eyes. The onset of thermoregulation occurred at a body mass (60 g) that was considerably less than predicted on the basis of adult body size. Huddling with littermates reduced the cooling of 20- to 60-g young at a Ta of 10°C, but did not advance the age (mass) at which they became effective homeotherms. Huddling by 20- to 60-g nestlings raised the mean Tb, leading to a substantive (64%) gain in the rate of oxygen consumption (Vo2). Conversely, in older nestlings that were close to or fully homeothermic, huddling with littermates consistently lowered Vo2, the greatest metabolic saving (38%) being realized by 17- to 21-d-old (100-140 g) young. We suggest that the rapid development of thermoregulation may be linked to the semiaquatic habit of muskrats, and that thermoregulatory behavior contributes importantly to the growth and morphological development of this prolific microtine rodent.

Ocular surface temperature differences in glaucoma

2021 ◽  
pp. 112067212110237
Author(s):  
Ari Leshno ◽  
Ori Stern ◽  
Yaniv Barkana ◽  
Noa Kapelushnik ◽  
Reut Singer ◽  
...  
Keyword(s):  
Surface Temperature ◽  
Thermal Imaging ◽  
Ocular Surface ◽  
Open Angle Glaucoma ◽  
Tissue Temperature ◽  
Body Temperatures ◽  
Current Thinking ◽  
Imaging Camera ◽  
The Mean ◽  
The Difference

Purpose: Accumulating evidence suggests that neuroinflammation and immune response are part of the sequence of pathological events leading to optic nerve damage in glaucoma. Changes in tissue temperature due to inflammation can be measured by thermographic imaging. We investigated the ocular surface temperature (OST) profile of glaucomatous eyes to better understand the pathophysiology of these conditions. Methods: Subjects diagnosed with glaucoma (primary open angle glaucoma [POAG] or pseudo exfoliation glaucoma [PXFG]) treated at the Sam Rothberg Glaucoma Center (11/2019–11/2020.) were recruited. Healthy subjects with no ocular disease served as controls. The Therm-App thermal imaging camera was used for OST acquisition. Room and body temperatures were recorded, and the mean temperatures of the medial cantus, lateral cantus, and cornea were calculated with image processing software. Results: Thermographic images were obtained from 52 subjects (52 eyes: 25 POAG and 27 PXFG) and 66 controls (66 eyes). Eyes with glaucoma had a significantly higher OST compared to controls (mean 0.9 ± 0.3°C, p < 0.005). The difference between the two groups remained significant after adjustment for age, sex, intraocular pressure (IOP) and room and body temperatures. Lens status and topical IOP-lowering medication did not significantly affect OST. A subgroup analysis revealed that the OST was higher among eyes with POAG compared to eyes with PXFG, but not significantly. Conclusions: Differences in the OST between glaucomatous and normal eyes strengthens current thinking that inflammation affects the pathophysiology of glaucoma. Longitudinal studies are warranted to establish the prognostic value of thermographic evaluations in these patients.

Phenological development and seasonal distribution of the rutherglen bug, Nnysius vinitor Bergroth (Hemiptera: Lygaeidae), on various hosts in Victoria, south-eastern Australia

1988 ◽  
Vol 78 (4) ◽  
pp. 673-682 ◽  
Author(s):  
Garrick McDonald ◽  
A. Mark Smith
Keyword(s):  
Rapid Development ◽  
Early Spring ◽  
Common Source ◽  
Body Temperatures ◽  
Ambient Temperatures ◽  
Polygonum Aviculare ◽  
Developmental Thresholds ◽  
Eastern Australia ◽  
Weed Hosts ◽  
Maximum Temperatures

AbstractPopulations of Nysius vinitor Bergroth were studied from 1979 to 1982 in two weed hosts, Arctotheca calendula and Polygonum aviculare, and eight irrigated sunflower crops in a summer cropping area of northern Victoria, Australia. The spring generation began with the adults colonizing flowering A.calendula plants in September and concluded with the rapid development of late stage nymphs and an exodus of adults from these plants from mid-November to December. Gradual invasion of sunflowers occurred mostly in late December and reached a peak at flowering, after which nymphs appeared. P. aviculare attracted adults from February and hosted a number of overlapping generations until winter. The weed sustained diminishing numbers of adults through the winter, except in 1982, when a further generation produced an early spring peak. Immigrant populations were regarded as a common source of adults for initiating the spring and summer generations. The rate of development of N. vinitor in spring was more rapid than that predicted by phenological simulation based on ambient temperatures and laboratory-derived day-degree estimates. This was attributed to increased body temperatures through absorption of solar radiation, and the simulation model was adjusted by increasing daily minimum and maximum temperatures by 1·3 and 5·5°C for young and older instars, respectively. This suggested that older nymphs have lower developmental thresholds or are better able to optimize body temperatures.

The Ontogeny of Ultrasonic Vocalization in Microtus Montanus

Behaviour ◽  
1977 ◽  
Vol 60 (1-2) ◽  
pp. 115-121 ◽  
Author(s):  
V.J. De Ghett
Keyword(s):  
Short Duration ◽  
Maternal Care ◽  
Ultrasonic Vocalization ◽  
Ultrasonic Vocalizations ◽  
Developmental Changes ◽  
Maternal Behaviour ◽  
Postnatal Ontogeny ◽  
Microtus Montanus ◽  
Early Peak ◽  
The Mean

AbstractDevelopmental changes in parameters of ultrasound production were investigated in M. montanus young. The rate of ultrasonic vocalization reached a peak on Day 2 of postnatal ontogeny and declined to zero on Day 15. A similar developmental pattern has been found in several other rodent species. However, the comparatively early peak rate is indicative of a degree of ontogenic precociousness. Other developmental changes, both behavioural and morphological, tend to confirm that M. montanus young are relatively precocious. The duration of ultrasonic vocalizations did not show a significant change across early development. The mean duration for each vocalization sampled was 22.92 msec. The distribution of these vocalizations showed that a considerable number of vocalizations were of very short duration (<30 msec). The developmental changes in the percentage of young emitting ultrasounds began to decline following Day 8 and reached zero percent on Day 15. This decline in the percentage of young vocalizing corresponded to changes in maternal behaviour. Both the rate of ultrasonic vocalization and the percentage of young vocalizing were significantly correlated with the age of the young. Being correlated with age, these parameters of ultrasound production have the possibility of having great communicative value for the purposes of maternal care.

Evaluation of Prenatal Transportation Stress on the Number of Pituitary Corticotrophs in Mature Brahman Cows

2021 ◽  
Vol 99 (Supplement_2) ◽  
pp. 24-25
Author(s):  
Victoria Kamilar ◽  
Sarah West ◽  
Brittni P Littlejohn ◽  
Charles R Long ◽  
David G Riley ◽  
...  
Keyword(s):  
Fetal Programming ◽  
Anterior Pituitary ◽  
Adrenocorticotropic Hormone ◽  
Developmental Changes ◽  
Control Group ◽  
Midsagittal Plane ◽  
Gland Weight ◽  
Group Control ◽  
The Mean ◽  
Transportation Stress

Abstract Prenatal transportation stress (PNS) results in calves that are more temperamental and have greater circulating concentrations of cortisol compared to control calves. The objective of this experiment was to evaluate whether PNS alters the number of pituitary corticotrophs in mature Brahman cows. We hypothesized that the increased circulating cortisol concentrations previously characterized in this bovine model is associated with developmental changes in the anterior pituitary leading to an increased number of corticotrophs. Pregnant Brahman cows (n = 48) were transported in trailers for 2-hour periods at 60±5, 80±5, 100±5, 120±5, and 140±5 days of gestation. Non-transported pregnant cows (n = 48) were designated as the Control group. Control and PNS offspring heifers were managed together under the same environmental conditions. At approximately 5 yr of age, randomly selected non-pregnant cows (Control, n = 8; PNS, n = 6) were humanely harvested and the whole pituitaries were collected. Pituitaries were weighed, fixed in paraformaldehyde, serially dehydrated with graded ethanol, embedded in paraffin blocks, and cut into 5-μm sections. Immunohistochemistry was performed to detect cells expressing adrenocorticotropic hormone (ACTH) as a marker for corticotrophs. Three comparable sections from the midsagittal plane from each animal were processed using an ovine ACTH-specific antibody (Dr. A.F. Parlow, NIDDK). Five fields of view were analyzed per section (15 fields per animal). Anterior pituitary gland weight did not differ (P &gt; 0.10) between groups (Control = 2.11 ± 0.12 g; PNS = 2.10 ± 0.15 g). The mean number of ACTH-positive cells between control (531±56 cells/section) and PNS cows (477±49 cells/section) also did not differ (P &gt; 0.10). In conclusion, the number of pituitary corticotrophs in mature Brahman cows was not affected by prenatal transportation stress and is likely not a mechanism mediating the increased circulating cortisol concentrations seen in this bovine model of fetal programming.

The Swimming of Nymphon Gracile (Pycnogonida): The Energetics of Swimming at Constant Depth

1977 ◽  
Vol 71 (1) ◽  
pp. 205-211
Author(s):  
ELFED MORGAN
Keyword(s):  
Oxygen Consumption ◽  
Metabolic Rate ◽  
Tidal Cycle ◽  
Active Phase ◽  
Constant Depth ◽  
Total Carbohydrate ◽  
Drag Forces ◽  
Rate Of Oxygen Consumption ◽  
The Mean ◽  
Tide Period

1. The mechanical power required by Nymphon for swimming at constant depth has been calculated from drag forces acting on the legs. For an adult male this was found to be 3.4 W kg. Only about 60% of this is used to support the animal's weight in water. 2. The metabolic rate fluctuates spontaneously over a tidal cycle, being greatest during the ebb-tide period. The mean rate of oxygen consumption during the animals least active phase was found to be about 0.1 μlO2 mg−1 h−1. 3. The total carbohydrate and lipid immediately available for combustion have been estimated at 4.64 and 16 μg/mg wet wt respectively. These quantities should be adequate for about 42 h periodic swimming in an adult Nymphon.

scholarly journals Early development and allometric growth in Nannacara anomala Regan, 1905 (Perciformes: Cichlidae) under laboratory conditions

2014 ◽  
Vol 12 (3) ◽  
pp. 659-665 ◽  
Author(s):  
Krzysztof Kupren ◽  
Maja Prusińska ◽  
Daniel Żarski ◽  
Sławomir Krejszeff ◽  
Dariusz Kucharczyk
Keyword(s):  
Early Development ◽  
Morphological Development ◽  
Allometric Growth ◽  
Laboratory Conditions ◽  
Total Length ◽  
Larvae And Juveniles ◽  
The Mean ◽  
Accelerated Growth

Morphological development and allometric growth of laboratory reared Nannacara anomala were studied from hatching to the loss of larval characters and beginning of squamation (18 days post-hatching) at 26°C. The mean total length (TL) of larvae and juveniles increased from 3.74 mm at hatching to 9.60 mm at metamorphosis. Morphogenesis and differentiation were most intense during the first week of development. During this period (TL interval = 3.74 - 4.84 mm) there was an evident priority to enhance the feeding and swimming capabilities by promoting accelerated growth in the head and tail regions. Following this period, there was a major decrease in growth coefficients, indicating a change in growth priorities. Observations on the early development of Nannacara anomala confirmed the basic uniformity development of a substrate brooding cichlid.

A study of growth changes in the mandible from deciduous to permanent dentition

2004 ◽  
Vol 27 (2) ◽  
pp. 137-142 ◽  
Author(s):  
Hung-Huey Tsai
Keyword(s):  
Cross Sectional Study ◽  
Permanent Dentition ◽  
Developmental Changes ◽  
Sectional Study ◽  
Cross Sectional ◽  
Mean Values ◽  
Males And Females ◽  
The Mean ◽  
Growth Changes ◽  
Ramus Height

This cross-sectional study investigated mandibular developmental changes in untreated normal Taiwanese from the deciduous to permanent dentition. Differences in the mean values for ramus height and body length between males and females were statistically significant after eruption of the permanent second molars. SNB angles significantly increased and gonial and L1-MP angles significantly decreased from deciduous to permanent dentition in both sexes. The SN-MP angle in females significantly decreased and ramus inclination in males significantly increased from the early mixed to permanent dentition.

INCONCLUSIONS OF STUDIES, MOSTLY OF PREMATURE INFANTS

PEDIATRICS ◽  
1951 ◽  
Vol 8 (2) ◽  
pp. 163-176
Author(s):  
HARRY H. GORDON
Keyword(s):  
Premature Infants ◽  
Dietary Factors ◽  
Body Temperatures ◽  
Acid Base Balance ◽  
Acid Base ◽  
Term Infants ◽  
Know How ◽  
Rate Of Oxygen Consumption ◽  
Base Balance ◽  
Phenol Ring

We do not know whether or how the rate of oxygen consumption by the cells of premature infants differs from that of full term infants. We do not know the clinical significance of subnormal body temperatures in premature infants. We do not know how much immature renal function and how much handicaps in intracellular defenses contribute to [See CHART 4, CHART 5 in Source PDF] the tendency of premature infants to develop disorders of water and acid-base balance. We do not know the nature of the deviation in ability of premature infants to absorb fat. We do not know how ascorbic acid and other dietary factors promote breaking open of the phenol ring of tyrosine or phenylalanine. We do not know what constitutes "immunity" to malaria. This is a doleful summary; it is a consolation to note the epigram of Rabbi Tarfon, written almost 1,900 years ago: "It is not for thee to complete the work, but neither art thou free to desist from it."

The roles of acidosis and lactate in the behavioral hypothermia of exhausted lizards

1999 ◽  
Vol 202 (3) ◽  
pp. 325-331
Author(s):  
E.L. Wagner ◽  
D.A. Scholnick ◽  
T.T. Gleeson
Keyword(s):  
Blood Lactate ◽  
Thermal Gradient ◽  
Elevated Blood ◽  
Body Temperatures ◽  
Exhausting Exercise ◽  
A Value ◽  
Arterial Ph ◽  
Injection Control ◽  
The Mean ◽  
Lactate Levels

We conducted this study to determine whether two of the physiological changes associated with non-sustainable exercise, elevated blood lactate levels and decreased arterial pH, contribute to the behavioral hypothermia exhibited by exhausted lizards. Dipsosaurus dorsalis were placed in a thermal gradient and their body temperatures were recorded from 08:00 to 14:00 h. At 14:00 h, animals were subjected to different experimental regimens. In the exercise (E) regimen, animals at 40 degrees C were forced to exercise maximally for 5 min on a treadmill. In the lactate (L) regimen, animals were infused with 11.5 ml kg-1 of 250–500 mmol l-1 sodium lactate. In the osmolarity control (O) regimen, animals were injected with 11.5 ml kg-1 of 500 mmol l-1 NaCl, and in the injection control (I) regimen, animals were injected with 11.5 ml kg-1 of 150 mmol l-1 NaCl. In the hypercapnia (H) regimen, the thermal gradient was flushed with a gas mixture containing 10 % CO2, 21 % O2 and 69 % N2, a treatment that lowers the arterial pH of D. dorsalis to a value comparable with that imposed by exhaustive exercise. A group of control (C) animals was left undisturbed in the thermal gradient for 24 h. Animals in all experimental groups were returned to the thermal gradient, and their cloacal temperatures were monitored until 08:00 h the following morning. The mean cloacal temperature of E animals underwent a significant decrease of 4–7 degrees C, relative to control animals, which persisted for 7 h. The mean cloacal temperatures of animals subjected to 2 h of regimen H also decreased by 3.5-9 degrees C and remained depressed for 12 h following the beginning of the treatment. L, O and I animals did not undergo a significant change in body temperature following treatment, and their mean body temperatures did not differ from those of C animals at any time during the experiment. The results of this study suggest that the metabolic acidosis, but not the elevated blood lactate level, that follows exhausting exercise might play a role in the behavioral hypothermia that follows exhausting exercise in D. dorsalis.

scholarly journals High-Speed Railway Clearance Intrusion Detection with Improved SSD Network

2019 ◽  
Vol 9 (15) ◽  
pp. 2981 ◽  
Author(s):  
Baoqing Guo ◽  
Jiafeng Shi ◽  
Liqiang Zhu ◽  
Zujun Yu
Keyword(s):  
Intrusion Detection ◽  
High Speed ◽  
Rapid Development ◽  
Single Shot ◽  
L1 Norm ◽  
Low Level ◽  
Model Size ◽  
Public Dataset ◽  
The Mean ◽  
High Level

With the rapid development of high-speed railways, any objects intruding railway clearance will do great threat to railway operations. Accurate and effective intrusion detection is very important. An original Single Shot multibox Detector (SSD) can be used to detect intruding objects except small ones. In this paper, high-level features are deconvolved to low-level and fused with original low-level features to enhance their semantic information. By this way, the mean average precision (mAP) of the improved SSD algorithm is increased. In order to decrease the parameters of the improved SSD network, the L1 norm of convolution kernel is used to prune the network. Under this criterion, both the model size and calculation load are greatly reduced within the permitted precision loss. Experiments show that the mAP of our method on PASCAL VOC public dataset and our railway datasets have increased by 2.52% and 4.74% respectively, when compared to the original SSD. With our method, the elapsed time of each frame is only 31 ms on GeForce GTX1060.

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