scholarly journals Regional Differences in Cuticular Permeability in the Desert Cicada Diceroprocta Apache: Implications for Evaporative Cooling

1989 ◽  
Vol 141 (1) ◽  
pp. 219-230 ◽  
Author(s):  
NEIL F. HADLEY ◽  
ERIC C. TOOLSON ◽  
MICHAEL C. QUINLAN
Keyword(s):  
Body Temperature ◽  
Water Loss ◽  
Temperature Increase ◽  
Regional Differences ◽  
Water Flux ◽  
Dorsal Surface ◽  
Male And Female ◽  
Cuticular Permeability ◽  
Higher Temperature

The cuticular permeability of the desert cicada Diceroprocta apache was measured in vivo from three regions of the dorsal surface: (1) the midline of the thorax (= dorsal thorax), a region that contains large pores (7–8 μm in diameter) located in a central tract; (2) the lateral thorax, a region in which large pores are absent, and (3) the midline of the abdomen, a region in which large pores are uniformly distributed over the surface. Transcuticular water flux rates were similar for all three areas at 27.0°C; however, at 41.5°C rates increased sharply for the dorsal thorax and abdomen, with tracings showing numerous irregular peaks that represent cycles of water extrusion. Transcuticular water flux for the lateral thorax, in contrast, was relatively unaffected by the temperature increase and the tracings remained relatively flat. Death of the animal at the higher temperature resulted in a significant decrease in water loss rates and a loss of the cycling pattern in both the dorsal thorax and abdomen, whereas water loss through the lateral thorax did not change. The active extrusion of water begins at 39.2-39.3°Cin both male and female cicadas. Our findings confirm that the large pores are the routes by which water reaches the surface and that the temperature at which this active extrusion of water begins corresponds to the point where cicadas must seek milder microclimates to prevent body temperature from reaching lethal levels.

scholarly journals A vapor exposure method for delivering heroin alters nociception, body temperature and spontaneous activity in female and male rats

2020 ◽  
Author(s):  
Arnold Gutierrez ◽  
Kevin M. Creehan ◽  
Michael A. Taffe
Keyword(s):  
Body Temperature ◽  
Spontaneous Activity ◽  
Female Rats ◽  
Male Rats ◽  
Sprague Dawley ◽  
Exposure System ◽  
Male And Female ◽  
Male And Female Rats ◽  
Sprague Dawley Rats

AbstractBackgroundThe ongoing crisis related to non-medical use of opioids makes it of continued importance to understand the risk factors for opioid addiction, the behavioral and neurobiological consequences of opioid exposure and to seek potential avenues for therapy. Pre-clinical rodent models have been critical to advancing understanding of opioid consequences for decades, but have been mostly limited to drug delivery by injection or by oral dosing. Inhalation, a significant route for many human users, has not been as well-established.MethodWe adapted an e-cigarette based exposure system, previously shown efficacious for delivery of other drugs to rats, to deliver heroin vapor. Effects in vivo were assessed in male and female Sprague-Dawley rats using a warm-water assay for anti-nociception and an implanted radiotelemetry system for evaluating changes in body temperature and spontaneous activity rate.ResultsInhalation of vapor created by heroin 100 mg/mL in the propylene glycol (PG) vehicle significantly slowed tail-withdrawal from a 52°C water bath, bi-phasically altered activity, and increased temperature in male and female rats. Inhalation of heroin 50 mg/mL for 15 minutes produced significant effects, as the lower bound on efficacy, whereas inhalation of heroin 100 mg/mL for 30 minutes produced robust effects across all endpoints and groups.ConclusionsThis work shows that e-cigarette devices deliver psychoactive doses of heroin to rats, using concentrations of ∼50-100 mg/mL and inhalation durations of 15-30 minutes. This technique may be useful to assess the health consequences of inhaled heroin and other opioid drugs.

scholarly journals Evaporative Cooling in the Desert Cicada: Thermal Efficiency and Water*sol;Metabolic Costs

1991 ◽  
Vol 159 (1) ◽  
pp. 269-283
Author(s):  
NEIL F. HADLEY ◽  
MICHAEL C. QUINLAN ◽  
MICHAEL L. KENNEDY
Keyword(s):  
Body Temperature ◽  
Gas Exchange ◽  
Water Loss ◽  
Thermal Efficiency ◽  
Evaporative Cooling ◽  
Water Flux ◽  
Simultaneous Measurements ◽  
Metabolic Costs ◽  
Hydration State

Using plant xylem water for evaporative cooling, the desert cicada Diceroprocta apache can maintain a body temperature as much as 5°C below ambient (Ta=42°C). Simultaneous measurements of water loss and gas exchange for cicadas feeding on perfused twigs show substantial increases in transpiration at temperatures at which evaporative cooling begins (between 37 and 38°C), but only modest increases in Vo2 and Vco2. The extent and duration of evaporative cooling depend on the cicada's hydration state and the rate of water flux from cuticular pores located on the surface of the thorax and abdomen.

scholarly journals Cortical neurons exhibit diverse myelination patterns that scale between mouse brain regions and regenerate after demyelination

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Cody L. Call ◽  
Dwight E. Bergles
Keyword(s):  
Cortical Neurons ◽  
Regional Differences ◽  
Brain Regions ◽  
Axon Diameter ◽  
Neuronal Identity ◽  
Cortical Areas ◽  
Myelin Sheaths ◽  
Parvalbumin Interneurons ◽  
Selection Of

ABSTRACTAxons in the cerebral cortex show a broad range of myelin coverage. Oligodendrocytes establish this pattern by selecting a cohort of axons for myelination; however, the distribution of myelin on distinct neurons and extent of internode replacement after demyelination remain to be defined. Here we show that myelination patterns of seven distinct neuron subtypes in somatosensory cortex are influenced by both axon diameter and neuronal identity. Preference for myelination of parvalbumin interneurons was preserved between cortical areas with varying myelin density, suggesting that regional differences in myelin abundance arises through local control of oligodendrogenesis. By imaging loss and regeneration of myelin sheaths in vivo we show that myelin distribution on individual axons was altered but overall myelin content on distinct neuron subtypes was restored. Our findings suggest that local changes in myelination are tolerated, allowing regenerated oligodendrocytes to restore myelin content on distinct neurons through opportunistic selection of axons.

scholarly journals In vivo synaptic density relates to glucose metabolism at rest in healthy subjects, but is strongly modulated by regional differences

2021 ◽  
pp. 0271678X2098150
Author(s):  
June van Aalst ◽  
Jenny Ceccarini ◽  
Stefan Sunaert ◽  
Patrick Dupont ◽  
Michel Koole ◽  
...  
Keyword(s):  
Glucose Metabolism ◽  
Medial Temporal Lobe ◽  
Regional Differences ◽  
Specific Binding ◽  
Aerobic Glycolysis ◽  
Glucose Consumption ◽  
Brain Regions ◽  
Synaptic Density ◽  
Energy Demands

Preclinical and postmortem studies have suggested that regional synaptic density and glucose consumption (CMRGlc) are strongly related. However, the relation between synaptic density and cerebral glucose metabolism in the human brain has not directly been assessed in vivo. Using [11C]UCB-J binding to synaptic vesicle glycoprotein 2 A (SV2A) as indicator for synaptic density and [18F]FDG for measuring cerebral glucose consumption, we studied twenty healthy female subjects (age 29.6 ± 9.9 yrs) who underwent a single-day dual-tracer protocol (GE Signa PET-MR). Global measures of absolute and relative CMRGlc and specific binding of [11C]UCB-J were indeed highly significantly correlated ( r > 0.47, p < 0.001). However, regional differences in relative [18F]FDG and [11C]UCB-J uptake were observed, with up to 19% higher [11C]UCB-J uptake in the medial temporal lobe (MTL) and up to 17% higher glucose metabolism in frontal and motor-related areas and thalamus. This pattern has a considerable overlap with the brain regions showing different levels of aerobic glycolysis. Regionally varying energy demands of inhibitory and excitatory synapses at rest may also contribute to this difference. Being unaffected by astroglial and/or microglial energy demands, changes in synaptic density in the MTL may therefore be more sensitive to early detection of pathological conditions compared to changes in glucose metabolism.

scholarly journals Pyrolysis and Oxidation of PAN in Dry Air. Thermoanalytical Methods

1970 ◽  
Vol 17 (1) ◽  
pp. 38-42
Author(s):  
Anna BIEDUNKIEWICZ ◽  
Pawel FIGIEL ◽  
Marta SABARA
Keyword(s):  
Temperature Increase ◽  
Heating Rates ◽  
Linear Change ◽  
Dry Air ◽  
Isothermal Conditions ◽  
Gaseous Products ◽  
Heterogeneous Processes ◽  
Temperature Ranges ◽  
Higher Temperature ◽  
Kinetics Of

The results of investigations on pyrolysis and oxidation of pure polyacrylonitrile (PAN) and its mixture with N,N-dimethylformamide (DMF) under non-isothermal conditions at linear change of samples temperature in time are presented. In each case process proceeded in different way. During pyrolysis of pure PAN the material containing mainly the product after PAN cyclization was obtained, while pyrolysis of PAN+DMF mixture gave the product after cyclization and stabilization. Under conditions of measurements, in both temperature ranges, series of gaseous products were formed.For the PAN-DMF system measurements at different samples heating rates were performed. The obtained results were in accordance with the kinetics of heterogeneous processes theory. The process rates in stages increased along with the temperature increase, and TG, DTG and HF function curves were shifted into higher temperature range. This means that the process of pyrolysis and oxidation of PAN in dry air can be carried out in a controlled way.http://dx.doi.org/10.5755/j01.ms.17.1.246

scholarly journals Monitoring Transepidermal Water Loss and Skin Wettedness Factor with Battery-Free NFC Sensor

Sensors ◽  
2020 ◽  
Vol 20 (19) ◽  
pp. 5549
Author(s):  
Syed Muhammad Ali ◽  
Wan-Young Chung
Keyword(s):  
Water Loss ◽  
Near Field ◽  
Experimental Tests ◽  
Transepidermal Water Loss ◽  
Comfort Level ◽  
Skin Wettedness ◽  
Moisture Content Level ◽  
Indoor And Outdoor Environments ◽  
Skin Moisture

The transepidermal water loss (TEWL) and the skin wettedness factor (SWF) are considered parts of a key perspective related to skincare. The former is used to determine the loss of water content from the stratum corneum (SC), while the latter is used to determine the human skin comfort level. Herein, we developed two novel approaches: (1) determination of the TEWL and the SWF based on a battery-free humidity sensor, and (2) the design of a battery-free smart skincare sensor device tag that can harvest energy from a near field communication (NFC)-enabled smartphone, making it a battery-free design approach. The designed skincare device tag has a diameter of 2.6 cm and could harvest energy (~3 V) from the NFC-enabled smartphone. A series of experimental tests involving the participation of eight and six subjects were conducted in vivo for the indoor and outdoor environments, respectively. During the experimental analysis, the skin moisture content level was measured at different times of the day using an android smartphone. The TEWL and SWF values were calculated based on these sensor readings. For the TEWL case: if the skin moisture is high, the TEWL is high, and if the skin moisture is low, the TEWL is low, ensuring that the skin moisture and the TEWL follow the same trend. Our smart skincare device is enclosed in a 3D flexible design print, and it is battery-free with an android application interface that is more convenient to carry outside than other commercially available battery-based devices.

scholarly journals Towards In Vivo Monitoring of Ions Accumulation in Trees: Response of an in Planta Organic Electrochemical Transistor Based Sensor to Water Flux Density, Light and Vapor Pressure Deficit Variation

2021 ◽  
Vol 11 (11) ◽  
pp. 4729
Author(s):  
Davide Amato ◽  
Giuseppe Montanaro ◽  
Filippo Vurro ◽  
Nicola Coppedé ◽  
Nunzio Briglia ◽  
...  
Keyword(s):  
Vapor Pressure ◽  
Flux Density ◽  
Precision Agriculture ◽  
Vapor Pressure Deficit ◽  
Accumulation Rate ◽  
Xylem Sap ◽  
Water Flux ◽  
Electrochemical Transistor ◽  
Olive Trees

Research on organic electrochemical transistor (OECT) based sensors to monitor in vivo plant traits such as xylem sap concentration is attracting attention for their potential application in precision agriculture. Fabrication and electronic aspects of OECT have been the subject of extensive research while its characterization within the plant water relation context deserves further efforts. This study tested the hypothesis that the response (R) of an OECT (bioristor) implanted in the trunk of olive trees is inversely proportional to the water flux density flowing through the plant (Jw). This study also examined the influence on R of vapor pressure deficit (VPD) as coupled/uncoupled with light. R was hourly recorded in potted olive trees for a 10-day period concomitantly with Jw (weight loss method). A subgroup of trees was bagged in order to reduce VPD and in turn Jw, and other trees were located in a walk-in chamber where VPD and light were independently managed. R was tightly sensitive to diurnal oscillation of Jw and at negligible values of Jw (late afternoon and night) R increased. The bioristor was not sensitive to the VPD per se unless a light source was coupled to trigger Jw. This study preliminarily examined the suitability of bioristor to estimate the mean daily nutrients accumulation rate (Ca, K) in leaves comparing chemical and sensor-based procedures showing a good agreement between them opening new perspective towards the application of OECT sensor in precision agricultural cropping systems.

Temperature gradients in vivo influence maturing male and female gametes in mammals: evidence from the cow

2017 ◽  
Vol 29 (12) ◽  
pp. 2301 ◽  
Author(s):  
R. H. F. Hunter ◽  
F. López-Gatius ◽  
O. López-Albors
Keyword(s):  
Follicular Fluid ◽  
Open Surgery ◽  
Temperature Gradients ◽  
Fluid Temperature ◽  
Preovulatory Follicle ◽  
Male And Female ◽  
Direct Measurements ◽  
Final Maturation ◽  
Preovulatory Follicles

Since 1980 several reports have indicated that temperatures vary between preovulatory follicles and other ovarian tissues in rabbit, cow, pig and human. However, these observations did not achieve prominence; they were regarded as artefacts due to the use of anaesthetics and open surgery (laparotomy). Recently, without resorting to anaesthesia or surgery, direct measurements of temperature in preovulatory follicles have been performed in the cow by means of a thermistor probe introduced into the antrum under ultrasonic guidance. Such follicles revealed a mean antral (follicular fluid) temperature 0.74°C and 1.54°C cooler than uterine surface and rectal temperatures respectively in ovulating cows, whereas no such temperature differences were detected in non-ovulating cows. Cows are predominantly monovular and preovulatory follicles attain a diameter of 15–22 mm or more. These features and the timescale of response to the preovulatory gonadotrophin surge make them a valuable model for the human preovulatory follicle. Temperature gradients are interpreted primarily in a context of final maturation of gametes immediately before the onset of fertilisation. Preovulatory follicular temperature in women could be assessed by a comparable approach and might become a valuable selection guide for oocyte viability.

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