Changes In Environmental Temperature Research Articles

A Standardized Protocol for Measuring Bioelectrical Impedance in Green Turtles (Chelonia mydas).

AbstractBioelectrical impedance analysis (BIA) is gaining popularity in wildlife studies as a portable technology for immediate and nondestructive predictions of body composition components, such as fat-free and fat masses. Successful application of BIA for field-based research requires the identification and control of potential sources of error, as well as the creation of and adherence to a standardized protocol for measurement. The aim of our study was to determine sources of error and to provide a standardization protocol to improve measurement precision of BIA on juvenile green turtles (Chelonia mydas; ). We assessed the effects of altered environmental temperature (20°C-30°C), postprandial state (2-72 h), and time out of the water (2 h) on five impedance parameters (resistance at infinite frequency [Rinf], resistance at zero frequency [R0], resistance at 50 kHz [R50], phase angle at 50 kHz [PhA50], and intracellular resistance [Ri]) using a bioimpedance spectroscopy device. Technical reproducibility of measurements and interanimal variability were also assessed. We found an inverse exponential relationship between change in environmental temperature and impedance parameters Rinf, R0, and R50. Postprandial state significantly increased Rinf and Ri 72 h after feeding. BIA measurements were reproducible within individual juvenile green turtles at temperatures from 20°C to 30°C. Significant variation in impedance values was found between animals at all temperatures, sampling times, and postprandial states, but the relative differences (%) were small in magnitude. Our study suggests that measurement precision is improved by measuring animals at consistent environmental temperatures close to their preferred thermal range. We propose a standardized protocol of measurement conditions to facilitate laboratory and field use of BIA for body composition assessment studies in turtles.

Modeling of nonuniform thermal deformation and high thermal stability design method for precision instruments

Structural deformations caused by environmental temperature changes are the main reason affecting the accuracy of high-precision instruments. A model of nonuniform thermal deformation is established. In addition, a new high thermal stability design method based on the developed model is proposed in this paper. The mechanism of nonuniform thermal deformation is investigated based on the principle of molecular dynamics. A mathematical model of nonuniform thermal deformation is established through the Large-scale Atomic/Molecular Massively Parallel Simulator. The proposed design method is applied to a laser collimation system. Stability contrast experiments for the original as well as the optimized laser collimation systems are also carried out. The stability of the optimized laser collimation systems is improved by approximately 60% with a temperature change of 10 °C. The experimental results indicate that the established model of nonuniform thermal deformation and the high thermal stability design method are effective and inexpensive, and can be applied to improve the thermal stability of other precision instruments.

Urban evolution of thermal physiology in a range-expanding, mycophagous fruit fly, Drosophila tripunctata

Abstract In Drosophila spp., their often high number of annual generations, large population sizes and large amounts of standing genetic variation should predispose them to undergo contemporary adaptation to climatic warming. However, a number of laboratory experimental evolution studies in this group of organisms suggest strong limits on the rate and magnitude of contemporary thermal adaptation. Here, we explore this discrepancy by examining the potential for rapid evolutionary divergence between wild populations of Drosophila tripunctata Loew, 1862 from rural and urban sites. We performed a multi-generation common garden study and found evidence for the evolution of higher heat tolerance (critical thermal maximum) in flies from urban populations. We also detected evolutionary divergence in cold resistance (chill coma recovery time), with diminished cold resistance in flies from urban populations, although the effect was weaker than the shift in heat tolerance. Our study provides evidence of contemporary urban thermal adaptation, although the magnitude of phenotypic change lagged the magnitude of environmental temperature change across the urbanization gradient, suggesting potential limits on the evolution of urban thermal physiology.

Influence of ambient temperature on personnel thermal comfort and working efficiency under isolation condition of underground engineering

When attacked by weapons of mass destruction, underground engineering will operate under isolation condition, which results in the increase of temperature, humidity, and CO2 concentration. At present, there are few studies on personnel thermal comfort and working efficiency in underground engineering, especially under isolation condition. To improve the personnel thermal comfort and working efficiency under such condition, the influence of environmental temperature changes on human thermal comfort and working efficiency was investigated through a combination of subjective and objective methods. A subjective questionnaire and working efficiency test were conducted on the subjects in the artificial climate chamber, and synchronously monitored electrocardiography (ECG), electroencephalography (EEG), and other physiological parameters of the subjects were recorded, when isolation condition was achieved in the artificial climate chamber. The results show that: (1) the human neutral temperature is 24.2 °C, and thermal comfort zone is [23 °C, 25.5 °C] for isolation condition; (2) the high working efficiency area is [27.3 °C, 28.8 °C] for isolation condition; (3) the average of the TSV corresponding to the highest working efficiency point is 1.3 under isolation condition; (4) from the correlation analysis of working efficiency and personnel physiological indicators, personnel EEG index and task performance are significantly related, and the ECG index and task performance are not relevant for subjects performing brain work under isolation conditions.

Uncovering adaptive mechanisms and resilience among older adults: A qualitative study on the mental health impacts of temperature variations.

Variable environmental temperature changes have affected different population groups; however, limited empirical studies in nursing have focused on older adults. One of the most pressing issues of today is climate change, where nurses should explore and advance their roles. This study aimed to explore and describe the experience of older adults with temperature variations as a consequence of climate change and its impact on mental health. Descriptive phenomenological approach was used in this study. Purposeful sampling was used in selecting key informants, while individual telephone interviews and videoconferencing platforms using a semi-structured interview guide were used as the data gathering method to gather key informants' accounts of their experiences. Prior to data collection, authors bracket their preconceived beliefs and values regarding the phenomenon at hand. Colaizzi's seven-step method of data analysis combined with the use of qualitative data analysis software was used to develop the themes and sub-themes. Eleven key informants aged 60-77 participated in this study. Sixty significant statements on temperature variations and mental health were extracted, while forty-one meanings were formulated from the significant statements. Important meanings were grouped into a cluster of themes which built the three major themes and seven sub-themes. The major themes are Theme 1: Active recollection and recognition of their experience; Theme 2: Symptoms of physical, social, mental, and cognitive aspects transformation; and Theme 3: Establishing adaptive mechanisms. The themes reflect a mental or cognitive process of recognizing and understanding their experiences, experiencing their impacts, developing adaptive mechanisms, and showing characteristics of resilience. The themes and sub-themes developed in this study showed that despite their vulnerability, older adults were able to implement adaptive mechanisms and showed signs of resiliency. Temperature variations brought limitations or adjustments to the physical, social, mental, and cognitive aspects of the key informants. Further studies should be conducted in other population groups and various geographical locations to identify sources of adaptive mechanisms and resilience to temperature variations and climate change among older adults. The findings should be used in developing health programs and crafting policies.

The effect of environmental temperature on bee activity at strawberry farms

AbstractThe response of bees to changing environmental temperatures has implications for pollination in natural and agricultural systems, with rising average temperatures and increased environmental stochasticity predicted to cause pollinator population declines. A growing body of evidence for the role of native bees in crop pollination suggests that understanding the temperatures at which bees are active is important for maintaining agricultural productivity under climate change. This study used two methods to sample bees at strawberry farms in south‐eastern Australia, matching activity observations with microclimate temperature to understand how temperature impacts bee activity. Apart from Apis mellifera (introduced), two native bees were identified, Lasioglossum spp. and Exoneura robusta. Apis mellifera was the most abundant species across all environmental temperatures, and E. robusta the least. Visual and sweep‐netting survey results found activity temperature range was broader for A. mellifera (16.21–41.05°C) than Lasioglossum (16.49–38.91°C) and E. robusta (26–38.82°C). The results suggest that activity temperature varies among bee species, with potential implications for community composition and plant pollination under climate change.

Ionic coordination strengthening of temperature-driven gradient hydrogel actuators with rapid responsiveness

Emerging applications of stimuli-responsive hydrogels as soft actuators and robotics have attracted great attention, but they face challenges in practical applications due to their poor mechanical properties, low driving force, and low actuation speed. Herein, we presented tough hydrogel actuators composed of a copolymer of N-isopropylacrylamide (NIPAM) and 3-sulfopropyl methacrylate potassium salt (SPA) monomers, and tunicate cellulose nanocrystals (TCNCs). The negatively charged TCNCs as nanofillers were gradient arranged by a direct current electric field (DC-EF) via electrophoresis. After in situ polymerization, TCNCs gradient distributed across the thickness of hydrogel, resulting in the formation of gradient crosslinking density of networks. Hydrogel actuators with high strength were obtained via Zr4+/−SO3- ionic coordination, whose tensile strength was about 200 times of hydrogel without ionic coordination. These hydrogel actuators exhibited rapid bending velocity, excellent stability, and good cycling performance in response to temperature. Importantly, these hydrogel actuators could be designed as soft robots to lift and transport objects by changing environment temperature. This work provided a facile yet efficient strategy to fabricate soft actuators with high strength and rapid responsiveness.

Development of a Novel Thermal Mannequin System for Thermal Comfort Measurements

Giving comfort to the wearer without feeling physiologically and psychologically by the wearer, assuming the role of thermoregulation system against environmental temperature changes, and making them psychologically happy with their appearance and attitude characteristics makes it easier to adapt to the environment in which they live. Since all these functions of garments are generally defined as ‘clothing comfort' and aim to increase the living standards of people, the studies carried out to measure clothing comfort in the most realistic way are of great importance both academically and sectorial. In this study, it is planned to carry out the thermal mannequin system that can act to objectively evaluate together with the important parameters of thermal, humidity and pressure comfort, which are the most important criteria in determining the clothing choice of consumers, that can provide measurement in different ambient conditions, and that allows instantaneous measurements of temperature, humidity and pressure. Within this plan, a practical mannequin system has been designed for thermal, humidity and pressure comfort measurements and will allow measuring and evaluating many features at the same time. The thermal mannequin system will be produced with practical and reconfigurable 3D printing technology, which allows re-production, unlike the thermal mannequin mechanisms in the literature.

Circadian Oscillations in the Murine Preoptic Area Are Reset by Temperature, but Not Light.

Mammals maintain their internal body temperature within a physiologically optimal range. This involves the regulation of core body temperature in response to changing environmental temperatures and a natural circadian oscillation of internal temperatures. The preoptic area (POA) of the hypothalamus coordinates body temperature by responding to both external temperature cues and internal brain temperature. Here we describe an autonomous circadian clock system in the murine ventromedial POA (VMPO) in close proximity to cells which express the atypical violet-light sensitive opsin, Opn5. We analyzed the light-sensitivity and thermal-sensitivity of the VMPO circadian clocks ex vivo. The phase of the VMPO circadian oscillations was not influenced by light. However, the VMPO clocks were reset by temperature changes within the physiological internal temperature range. This thermal-sensitivity of the VMPO circadian clock did not require functional Opn5 expression or a functional circadian clock within the Opn5-expressing cells. The presence of temperature-sensitive circadian clocks in the VMPO provides an advancement in the understanding of mechanisms involved in the dynamic regulation of core body temperature.

An Energy-Based Damage Diagnosis Under Changing Environmental Temperature for Online SHM

Structural health monitoring (SHM) for early diagnosis of damage in structures has become vital in improving the structural integrity and safety of the structure and thereby providing a smooth operation for most of the important in-service civil structures such as buildings and bridges. SHM also contributes to the substantial reduction in the maintenance cost of the structure. During serious structural failures, SHM can safeguard human life through an early warning system. This paper presents an output-only model-free technique by extracting damage features from the energy profiles derived from measured time-history responses. The proposed algorithm is organized into two phases i.e. the learning phase and the monitoring phase. While the learning phase can optionally be executed offline, the monitoring phase can preferably be online. The damage feature is extracted by carrying out a fractal dimension analysis of the continuous waveform of energy associated with the jolt (i.e. rate of change of acceleration) evaluated from the acceleration responses of the structure. A novel damage index is proposed, to localize the damage, using the damage features extracted from the fractal dimension, while handling operational and environmental variability (EoV). The proposed algorithm is evaluated through numerical simulations on a typical span of 220[Formula: see text]m RCC bridge across river Amaravathi in Tamil Nadu, India and also a 20-story frame structure. Experimental investigations are also carried out by testing a laboratory-scale 10-story frame structure and also an RCC bridge model of a 7.7[Formula: see text]m span to evaluate the practical amenability of the proposed algorithm. The experimental and numerical studies carried out in this paper, suggest that the proposed energy-based diagnostic technique can effectively localize the damage even in the presence of confounding factors like EoV. Conclusively, the proposed diagnostic technique can be an effective tool for online SHM, as it is model-free with less tedious computations and can perform well even in the presence of noise.

Temporal variation in climatic factors influences phenotypic diversity of Trochulus land snails

Organisms with limited dispersal capabilities should show phenotypic plasticity in situ to keep pace with environmental changes. Therefore, to study the influence of environmental variation on the phenotypic diversity, we chose land snails, Trochulus hispidus and T. sericeus, characterized by high population variability. We performed long-term field studies as well as laboratory and common garden experiments, which revealed that temporal environmental changes generate visible variation in shell size and shape of these snails. Many shell measurements of T. hispidus varied significantly with temperature and humidity in individual years. According to this, the first generation of T. hispidus, bred in controlled laboratory conditions, became significantly different in higher spire and narrower umbilicus from its wild parents. Interestingly, offspring produced by this generation and transplanted to wild conditions returned to the ‘wild’ flat and wide-umbilicated shell shape. Moreover, initially different species T. hispidus and T. sericeus transferred into common environment conditions revealed rapid and convergent shell modifications within one generation. Such morphological flexibility and high genetic variation can be evolutionarily favored, when the environment is heterogeneous in time. The impact of climate change on the shell morphometry can lead to incorrect taxonomic classification or delimitation of artificial taxa in land snails. These findings have also important implications in the context of changing climate and environment.

Demonstration of a ZnO-Nanowire-Based Nanograting Temperature Sensor

In this study, we experimentally demonstrate a miniature fiber thermometer based on tip-integrated ZnO-nanowire-nanograting. The sensor has a diameter less than 1 µm and the length of the Bragg grating is sub-10 µm. The ZnO-nanowire-nanograting is sensitive to the environmental temperature change. Thus, the intensity of the light whose wavelength is in the rising or falling region of the nanograting spectrum will vary with the shift in wavelength due to change in temperature. Taking one wavelength (655 nm) in the rise linear region of the nanograting spectrum, a sensitivity of 0.066 nW/°C in the air is achieved experimentally. The proposed temperature sensor has the superiorities of compactness, stableness, and easy fabrication compared to regular fiber grating sensors, offering great potential for detecting inside minimal volume environments.

Effects of acute temperature change on California moray prey manipulation and transport behavior

California moray eels, Gymnothorax mordax, are benthic predatory residents of southern California kelp forest ecosystems. California morays around Catalina Island move vertically through the water column to feed, exposing them to a wide range of temperatures. For a predatory fish, morays have a relatively large prey handling repertoire that enable them to manipulate their prey before swallowing. Prey manipulation behaviors include shaking, spinning, knotting, and ramming prey against other objects. Morays also have observable transport mechanics where they protract and retract their pharyngeal jaws to swallow prey. We examined prey manipulation and transport behaviors at four temperature treatments that simulated the range of environmental temperatures morays encounter in the wild. We hypothesized that higher temperatures will increase the prevalence, duration, and rate of whole body prey manipulation behaviors and decrease the duration of prey transport time. Previous temperature studies focused on fishes occupying intermediate trophic levels. Therefore, understanding how acute temperature affects feeding behavior of the California moray eel, an abundant predatory fish, is especially important, as changes in environmental temperature may have disproportionate effects in their marine community. Five morays were acutely exposed to 15, 18, 21, 24 °C temperatures and their subsequent feeding behaviors were filmed and quantified. Individuals were offered the same relative prey mass (15 %) in relation to their body mass throughout the study. We compared the number of times each prey manipulation behavior occurred, the mean time morays employed each behavior, and the rate (number of times per second) each behavior was performed across different temperatures. Our data demonstrates that absolute time spent knotting varies significantly across temperature. Knotting, often used to remove pieces from larger prey, was most frequent at 21 and 24 °C. The average duration of knotting also increased with temperature. The rates of prey manipulation behaviors did not vary significantly with temperature. Finally, transport behavior did not vary across treatments. Our study shows that knotting behavior in the California moray is responsive to environmental temperatures and that morays may be able to manipulate larger prey in warmer waters. These behavioral data may have important implications for predator-prey relationships under dynamic and future ocean conditions.

The response of tropical cyclone intensity to changes in environmental temperature

Abstract. Theory indicates that tropical cyclone (TC) intensity should respond to environmental temperature changes near the surface and in the TC outflow layer. While the sensitivity of TC intensity to sea surface temperature is well understood, less is known about the role of upper-level stratification. In this paper, we combine historical data analysis and idealised modelling to explore the extent to which historical low-level warming and upper-level stratification can explain observed trends in the TC intensity distribution. Observations and modelling agree that historical global environmental temperature changes coincide with higher lifetime maximum intensities. Observations suggest the response depends on the TC intensity itself. Hurricane-strength storms have intensified at twice the rate of weaker storms per unit surface and upper-tropospheric warming, and we find faster warming of low-level temperatures in hurricane environments than the tropical mean. Idealised simulations respond in the expected sense to various imposed changes in the near-surface temperature and upper-level stratification representing present-day and end-of-century thermal profiles and agree with TCs operating as heat engines. Removing upper-tropospheric warming or stratospheric cooling from end-of-century experiments results in much smaller changes in potential intensity or realised intensity than between present day and the end of the century. A larger proportional change in thermodynamic disequilibrium compared to thermodynamic efficiency in our simulations suggests that disequilibrium, not efficiency, is responsible for much of the intensity increase from present day to the end of the century. The limited change in efficiency is attributable to nearly constant outflow temperature in the simulated TCs among the experiments. Observed sensitivities are generally larger than modelled sensitivities, suggesting that observed TC intensity change responds to a combination of the temperature change and other environmental factors.

Interferometric radius of curvature measurements: an environmental error treatment.

Interferometric determination of sphere radii is a well known technique. To keep accuracy high and uncertainties low, a precisely controlled environment is usually necessary. Environmental changes in temperature lead to time dependent drift in important measurement parameters and to disturbed results. We present a method to minimize time dependent drift to the first order. With this method, it is either possible to reduce the uncertainties further, or to relax environmental conditions and still be able to accomplish high precision measurements. We discuss two typical measurement configurations, the associated benefits and drawbacks and some relevant error sources.

High-performance, additively-manufactured atomic spectroscopy apparatus for portable quantum technologies.

We demonstrate a miniaturised and highly robust system for performing Doppler-free spectroscopy on thermal atomic vapour for three frequencies as required for cold atom-based quantum technologies. The application of additive manufacturing techniques, together with efficient use of optical components, produce a compact, stable optical system, with a volume of 0.089 L and a weight of 120 g. The device occupies less than a tenth of the volume of, and is considerably lower cost than, conventional spectroscopic systems, but also offers excellent stability against environmental disturbances. We characterise the response of the system to changes in environmental temperature between 7 and 35 ∘C and exposure to vibrations between 0 - 2000 Hz, finding that the system can reliably perform spectroscopic measurements despite substantial vibrational noise and temperature changes. Our results show that 3D-printed optical systems are an excellent solution for portable quantum technologies.

The Effect of Temperature and Nutrient on Developmental Biology and Physiology of Stored-Product Species of Coleoptera

Insect pests of stored crops damage agricultural products in the fields or warehouses and cause crop loss. For this reason, it is of great importance to protect the products in warehouses after harvest. Many chemical control methods are being researched to prevent the damage they cause to the stored product. As the negative effects of these chemicals used in recent years on the environment and living things have been understood, different methods have been started to be developed. Because insects adapt to the environment very quickly, they develop more resistance to the chemicals used over time. For this reason, the biology and physiology of insects should be well known in the fight against insects. The better the biology and physiology of an insect are known, the more new methods can be developed in the integrated control methods of this insect. Insects are poikilothermic organisms. In other words, since they are organisms dependent on changes in environmental temperatures, temperature is very important in their development. Another factor affecting the biology and physiology of insects is nutrient. Temperature and food together can limit insect developmental stages. While high temperatures prolong the developmental stages, it can have the opposite effect in the adult period. Or insects feeding on poor quality nutrient can affect egg and adult size or cuticle development, as seen in some beetles. In this review study, the effects of temperature and nutrient on the biology and physiology of storage product pest Coleopters were evaluated.

Field test and numerical simulation of the thermal insulation effect of concrete pouring block surface based on DTS

The change in environmental temperature, especially a sharp decline of air temperature, is the critical factor for cracking damage to concrete arch dam structures. In this study, the field test and numerical calculation of the insulation effect of concrete pouring block surface were performed to prevent thermal cracks in concrete arch dams. In the field test, the temperature data of concrete at different depths measured by a distributed temperature sensing (DTS) system were analysed. The results showed that the temperature of concrete at different depths from the surface was significantly positively correlated with air temperature, and the influence depth was within 50 cm from the top surface of pouring block. During numerical simulation, the differences in surface insulation measures in insulation materials, insulation thickness, insulation time, and insulation space position were simulated and compared, considering the influence of the concrete insulation layer and cooling water. The numerical solutions showed that: (1) When the insulation material changed from 2 cm polyethylene insulation layer to 5 cm polystyrene insulation layer, the surface stress of concrete decreases from 0.86Mpa to 0.59Mpa; the insulation time was advanced to before the temperature drop, the surface stress from 0.86Mpa to 0.25Mpa; and the change of insulation position, the tensile stress of the top surface of pouring block was almost unchanged. (2) In this temperature drop, the surface insulation measure was recommended: the insulation material and thickness was the 5 cm polystyrene insulation layer, the insulation time is before the temperature drop, and the insulation position is the top surface, transverse joint surface and upstream and downstream surface of the pouring block.

Estimations of the elastic moduli of concrete at different temperatures and humidities by mesomechanics methods

Changes of environmental temperature and humidity affect the elastic modulus of concrete, which makes the vibration-based bridge health monitoring method unreliable. This research studied the effects of environmental temperature and moisture content on the effective elastic modulus of concrete by the mesomechanics methods. In meso level, for the two components of concrete, pores and micro cracks, effects of water in them on the effective elastic modulus at different temperatures were studied separately. Then estimations of the effective elastic moduli at different temperatures and moisture contents were proposed. To verify this, the calculated effective elastic moduli were compared with the experimental values. Finally, the mechanism of the variations of the effective elastic moduli with temperature was revealed. The proposed estimations of the effective elastic modulus can offer a simple and reliable approach to obtain the accurate elastic modulus of concrete based on the environmental temperature and concrete moisture content, which can eliminate their effects in bridge health monitoring.

Temperature modulating the peroxidase-mimic activity of poly(N-isopropyl acrylamide) protected gold nanoparticles for colorimetric detection of glutathione

More recently, loading polymer-ligand onto the surface of gold nanoparticles (AuNPs) as nanozymes has gained considerable attention. However, the efficient modulation of the nanozymes catalytic capability depending on external stimuli remains challenging. Herein, utilizing the thermo-responsive poly(N-isopropyl acrylamide) (PNIPAM) as a stabilizer and a reducing agent to make PNIPAM@AuNPs, we reported a straightforward and efficient protocol for modulating the peroxidase-mimic catalytic capability of PNIPAM@AuNPs in oxidation of 3,3′,5,5′-tetramethyl benzidine (TMB)–H2O2 system by change of environmental temperature. More hydroxylradicals yielded and surface confinement effect induced by the coiled PNIPAM chains at high temperature could further significantly boost the nanozymes catalytic capability. In the presence of glutathione, the generation of oxidized TMB was inhibited and the absorption intensity of the reaction system decreased at 650 nm. The color-fadingproperty provided a highly selective assay for visualized and quantitative test of glutathione ranging 1.0 ～ 17.0 μM (R2 = 0.993), the limit of detection was 0.8 μM. Moreover, the proposed method exhibited a promising application in analysis of rat serum glutathione following an intravenous injection. The strategy supplies a facile guideline for preparation of stimuli-responsive polymer@AuNPs with improved peroxidase-mimic catalytic activity toward application in real living bio-systems.