Laboratory Temperature Research Articles

Utilizing Environmentally and Recycled Materials to Formulate Drilling Mud

It is important to pay attention to environmental regulations while preparing drilling mud because it has become aspects that must be taken into consideration both now and in the future. It is essential to use sustainable and environmentally friendly materials at every stage of the oil and gas industry if possible in order to ensure high standards of sustainable practices. Oil that has been used to prepare oil base mud have bad impact on soil and human at the same time. The using of flaxseed oil instead of gas oil to preparing emulsion is done in this paper. The results were encouraging, and showed the possibility of using flaxseed oil for preparing ecological emulsion. The efficacy of walnut shell powder as an emulsifying agent has been tested as a surface tension reducer and the possibility of using it to increase the stability of an oil emulsion either in reverse or direct at high temperatures (400°F). This research includes measurements of filtration, stability and rheological properties of oil emulsion under laboratory and high temperature. Sample C showed high stability less than 3% because it is a direct emulsion composed of 10% flaxseed oil and crushed walnut shells, which acted as an excellent emulsifying agent because it was composed of cellulose with a percentage of more than 40%. Sample E gave the highest viscosity values, and the reason for this is that it is a reverse emulsion consisting of 60% flax oil with a high viscosity, as it reached more than 70 centipoises at 400 degrees Fahrenheit.

Autonomous Planetary Liquid Sampler (APLS) for In Situ Sample Acquisition and Handling from Liquid Environments.

Many natural and artificial liquid environments, such as rivers, oceans, lakes, water storage tanks, aquariums, and urban water distribution systems, are difficult to access. As a result, technology is needed to enable autonomous liquid sampling to monitor water quality and ecosystems. Existing in situ sample acquisition and handling systems for liquid environments are currently limited to a single use and are semi-autonomous, relying on an operator. Liquid sampling systems should be robust and light and withstand long-term operation in remote locations. The system components involved in liquid sampling should be sterilisable to ensure reusability. Here, we introduce a prototype of a liquid sampler that can be used in various liquid environments and may be valuable for the scientific characterisation of different natural, remote, and planetary settings. The Autonomous Planetary Liquid Sampler (APLS) is equipped with pre-programmed, fully autonomous extraction, cleaning, and sterilisation functionalities. It can operate in temperatures between -10 °C and 60 °C and pressure of up to 0.24 MPa (~24 m depth below mean sea level on Earth). As part of the control experiment, we demonstrate its safe and robust autonomous operation in a laboratory environment using a liquid media with Bacillus subtilis. A typical sampling procedure required 28 s to extract 250 mL of liquid, 5 s to fill the MilliQ water, 25 s for circulation within the system for cleaning and disposal, and 200 s to raise the system temperature from ~30 °C ambient laboratory temperature to 150 °C. The temperature is then maintained for another 3.2 h to sterilise the critical parts, allowing a setup reset for a new experiment. In the future, the liquid sampler will be combined with various existing analytical instruments to characterise the liquid solution and enable the autonomous, systematic monitoring of liquid environments on Earth.

In vitro anthelmintic activity of hydroethanolic extract of Artemisia herba aba and Juniperus phoenicea on abomasal Teladorsagia circumcincta of sheep.

The present study aimed to evaluate the in vitro anthelmintic activity of Juniperus phoenicea and Artemisia herba-alba against abomasal nematodes collected from naturally infected sheep. The anthelmintic activities of the extracts were assessed using egg hatch inhibition (EHIA) and adult motility assays (AMA) against Teladorsagia circumcincta. The parasites were stored in phosphate-buffered saline (PBS) until the in vitro assessment began. The leaf powders of J. phoenicea and A. herba-alba were extracted using the maceration procedure. Briefly, the leaf powders were mixed with a sufficient quantity of 99% ethanol and distilled water (80%/20%). The extracts were dissolved in a 3% dimethyl sulfoxide (DMSO) solution to improve water solubility. The hydroethanolic extracts were tested at concentrations of 1.562, 3.125, 6.25, 12.5, and 25 mg/ml. Adult motile worms were individually subjected to each treatment at laboratory temperature. The PBS and albendazole (25 mg/ml) were prepared and used as negative and positive controls, respectively. The test was repeated five times for each concentration. The results showed that both plant extracts exhibited anthelmintic effects. A. herba-alba extract at 25 mg/ml inhibited the motility of all T. circumcincta adult worms within 1 hour of administration, while J. phoenicea extract caused 100% mortality of adult worms after 4 hours at the same concentration. Neither of the extracts, at 1.562 mg/ml, had any inhibitory effect on motility. At 25 mg/ml, the A. herba-alba (98.67%) and J. phoenicea (96.24%) showed high activity with an inhibitory effect on hatchability compared to the other tested concentrations. The findings of the present study showed that hydroethanolic extracts of A. herba-alba and J. phoenicea leaves had in vitro anthelmintic activity on eggs and adult T. circumcincta of sheep.

The evaluation of the effects of different curing methods on concrete

This research explores the impact of various curing methods on the water absorption and compressive strength of concrete. To evaluate these properties, 45 cubes of mix ratio 1:2:4 were tested under different curing methods namely water ponding, sand, polythene sheet coverage, sawdust and water sprinkling. All the cubes were cured at an average laboratory temperature. Water absorption, compressive strength and SEM-EDX tests were conducted on the concrete cubes after curing for 7, 14 and 28 days. The study found that the water absorption and compressive strength values at 7, 14, and 28 curing days ranged from 1.53 to -1.12% and 21.30 to 31.40 N/mm2, respectively and varied depending on the curing method used. All the cementitious compositions of the concrete cubes of all the curing methods showed an increase with the increase in curing age and ranged between 0.01 and 81.67, while their SEM images revealed heterogeneous microstructures consisting of aggregates, cement paste, and voids.Sand and sawdust curing produced the highest and lowest compressive strength values, respectively. Based on these findings, sand curing was identified as the most favourablemethod. Further investigation should be carried out.

Theory and Measurement of Heat Transport in Solids: How Rigidity and Spectral Properties Govern Behavior.

Models of heat transport in solids, being based on idealized elastic collisions of gas molecules, are flawed because heat and mass diffuse independently in solids but together in gas. To better understand heat transfer, an analytical, theoretical approach is combined with data from laser flash analysis, which is the most accurate method available. Dimensional analysis of Fourier's heat equation shows that thermal diffusivity (D) depends on length-scale, which has been confirmed experimentally for metallic, semiconducting, and electrically insulating solids. A radiative diffusion model reproduces measured thermal conductivity (K = DρcP = D × density × specific heat) for thick solids from ~0 to >1200 K using idealized spectra represented by 2-4 parameters. Heat diffusion at laboratory temperatures (conduction) proceeds by absorption and re-emission of infrared light, which explains why heat flows into, through, and out of a material. Because heat added to matter performs work, thermal expansivity is proportional to ρcP/Young's modulus (i.e., rigidity or strength), which is confirmed experimentally over wide temperature ranges. Greater uptake of applied heat (e.g., cP generally increasing with T or at certain phase transitions) reduces the amount of heat that can flow through the solid, but because K = DρcP, the rate (D) must decrease to compensate. Laser flash analysis data confirm this proposal. Transport properties thus depend on heat uptake, which is controlled by the interaction of light with the material under the conditions of interest. This new finding supports a radiative diffusion mechanism for heat transport and explains behavior from ~0 K to above melting.

Characteristics of 2N4416 Si JFETs for radiation spectrometer charge sensitive preamplifiers

The input transistors (JFETs) of feedback resistor-less charge sensitive preamplifiers (CSPs), for photon and charged particle counting radiation spectrometers, that use semiconductors as their detectors, are operated in an unusual forward biased mode; consequently, manufacturer datasheets cannot necessarily be relied upon, as they do not specify the characteristics of the JFETs when they are operated with the gate-to-source junction forward biased. This experimental study, in which 165 2N4416 and 2N4416A NJ26 silicon junction field effect transistors (JFETs) were electrically characterised at ambient laboratory temperature, focused on the JFETs’ performances in the context of their use as input transistors of feedback resistor-less charge sensitive preamplifiers (CSPs). The experimental study found evidence which supports much of the common practice of the skilled CSP designer but which had not been documented with results in the open literature until now. This includes, inter alia, that: the 2N4416 performs better than the 2N4416A; not all transistors even of the same type have comparable performance when operated in forward bias mode; only a small proportion of 2N4416 and 2N4416A transistors are of desirable performance characteristics for CSPs; and, individual screening of each candidate JFET is required if an optimally performing CSP is to be produced – even when using JFETs of the same type from the same batch. The methodology and analysis documented here will also be useful to researchers developing new wide bandgap semiconductor JFETs for high temperature tolerant and radiation-hard CSPs.

Study on temperature regulation capability of asphalt mixture modified by dual phase change material used in ultra-thin overlay

ABSTRACT A dual-phase change material (DPCM) containing polyethylene glycol (PEG) 400/expanded graphite (EG) and PEG1500/EG with both high and low-temperature regulation capacities was prepared. It was added as an additive to the NovaChip-Type C asphalt mixtures. Laboratory and field temperature regulation tests were designed. The images taken by SEM showed that PEG was fully adsorbed by EG and the structure of DPCM was stable. The test results showed the DPCM has good durability in the cyclic phase change process. The modified asphalt binders with different DPCM content showed different heat storage capacity. The results of temperature regulation tests showed that the addition of DPCM effectively reduced the temperature change rate of asphalt mixtures. With 1.88% DPCM, the extremum of high temperature of asphalt mixtures reduced by 2.3°C while the extremum of low temperature increased by 2.0°C. In terms of road performance, the cracking resistance at low temperature of asphalt mixtures gradually improved with the increase of DPCM content. Meanwhile, the rutting resistance at high temperature and water damage resistance still met the requirements of the specification. The DPCM had a good effect on restraining the occurrence of road diseases caused by temperature and prolonging the service life of the road.

Biology of the parasitoid Melittobia sosui Dahms, 1984 (Hymenoptera: Eulophidae) with details on its ecology, development, and reproduction in Vietnam

Summary In this study, we determined the total developmental time of Melittobia sosui Dahms from the egg to the emergence of imagoes being 12.7–30 days for males and 14.7–34.6 days for macropterous females. Its developmental time depended on the laboratory temperature and humidity. Based on tests of the developmental time through 23 months from 2019 to 2021 and field-collected data, it is concluded that Melittobia sosui is active throughout year except for its pupal diapause lasting 2–3 weeks during the winter. The average life cycle was 23 ± 7.5 days. Males did not feed after emerging and lived from 6.5 to 8.2 days. Females feeding on host hemolymph had a life span from 29.2 to 42.2 days depending on the room temperature and humidity. The number of offspring produced depended on the host quality and varied from 65.6 to 145.4 individuals per foundress. Related to host weights, Melittobia sosui held an offspring clutch size of about 2.6 individuals per mg of Chalybion malignum (Kohl) and about 1.6 individuals per mg of Chalybion bengalense (Dahlbom) and of Sceliphron madraspatanum kohli Sickmann (three, Sphecidae). Regardless of the laboratory temperature and relative humidity, but depending on the host quality (different hosts), the sex ratio varied from 0.96 to 0.98, the average female-dimorphism ratio was 0.99 ± 0.01 and the mean developmental mortality rate of pupa was 0.92 ± 1.78%. Our findings provide a better understanding of the biology and ecology of Melittobia sosui and contribute to devising suitable control measures for the species.

Tapinarof and its structure-activity relationship for redox chemistry and phototoxicity on human skin keratinocytes

Tapinarof (3,5-dihydroxy-4-isopropylstilbene) is a therapeutic agent used in the treatment of psoriasis (VTAMA®). In this study, we examined the redox behaviour, (photo)stability, (photo)toxicity and (bio)transformation of tapinarof in the context of a structure-activity relationship study. Selected derivatives of the structurally related tapinarof were investigated, namely resveratrol, pterostilbene, pinosylvin and its methyl ether. Tapinarof undergoes electrochemical oxidation in a neutral aqueous medium at a potential of around +0.5 V (vs. Ag|AgCl|3M KCl). The anodic reaction of this substance is a proton-dependent irreversible and adsorption-driven process. The pKa value of tapinarof corresponds to 9.19 or 9.93, based on empirical and QM calculation approach, respectively. The oxidation potentials of tapinarof and its analogues correlate well with their HOMO (highest occupied molecular orbital) energy level. The ability to scavenge the DPPH radical decreased in the order trolox ≥ resveratrol > pterostilbene > tapinarof > pinosylvin ≫ pinosylvin methyl ether. It was also confirmed that tapinarof, being a moderate electron donor, is able to scavenge the ABTS radical and inhibit lipid peroxidation. The 4′-OH group plays a pivotal role in antioxidant action of stilbenols. During the stability studies, it was shown that tapinarof is subject to spontaneous degradation under aqueous conditions, and its degradation is accelerated at elevated temperatures and after exposure to UVA (315–399 nm) radiation. In aqueous media at pH 7.4, we observed an ∼50 % degradation of tapinarof after 48 h at laboratory temperature. The main UVA photodegradation processes include dihydroxylation and hydration. In conclusion, the phototoxic effect of tapinarof on a human keratinocytes cell line (HaCaT) was evaluated. Tapinarof exhibited a clear phototoxic effect, similar to phototoxic standard chlorpromazine. The IC50 values of the cytotoxicity and phototoxic effects of tapinarof correspond to 27.6 and 3.7 μM, respectively. The main HaCaT biotransformation products of tapinarof are sulfates and glucuronides.

Study of the behaviour of recycled and traditional fibres in cement composite at extreme temperatures

The use of fibres in concrete is one of the methods to increase the resistance of concrete to high temperatures. A wide range of different types of fibres are currently available. However, as part of the global trend to reduce the environmental impact of the construction industry, the use of new types of recycled fibres is also being proposed. In this work, the behaviour of selected fibre types in cement composite mortar at different loading temperatures was investigated. The fibres used were industrially produced polypropylene fibres, recycled fibres from PET bottles and two types of cellulose fibres of which one type is produced by recycling wastepaper. Fibres were added to the cement composites in percentages ranging from 0, 0.3, 0.6, 0.75, 0.9–1.2 %. The properties of the cement composites, such as flexural and compressive strength, were tested at different fibres percentages at laboratory temperatures of 200, 400, 600 and 800 °C. For all types of fibres used, the workability of the fresh mixture was found to be decreased. Comparable strength results to the reference mixture were obtained when recycled polypropylene and cellulose fibres were used. Based on the results obtained, the most effective fibres dosage was determined to be 0.6 %. The most positive tensile flexural and compressive strength results after a thermal loading of 800 °C were obtained with recycled cellulose fibres compared to the reference mixture without fibres. It was evaluated by microscopic observation that the cellulose fibres are present in the composite even at temperatures around 400 °C, while the polymer fibres are completely burnt out. The research confirmed the clear benefits of using recycled fibres instead of conventionally used polymer fibres.

Incandescent Lamp from Black Body Perspective

The incandescent lamp from black body perspective was investigated using commercial lamps of various watts. The major component of the incandescent lamp is the tungsten filament. The resistance of the tungsten filament was measured using a digital multimeter at an initial laboratory temperature. Light produced from lamp was separated into visible colours by an equilateral triangular glass prism. Deduced resistances were used to obtain equivalent temperatures by power-law parameterization. The Wien’s displacement law was used to estimate Peak wavelengths at different temperatures. The diameter of the tungsten was measured after dissecting the lamp, and this was used to determine its cross-sectional area. Both Wien’s displacement law and Stefan-Boltzmann expressions were applied in determining the filament’s spectral emissive power (SEP) in comparison with that of the visible spectrum. Planck’s graph of intensity using peak wavelength of tungsten filament as reference was juxtaposed with the intensity of visible spectrum using OriginPro 2016 SR0 b9.3.226. The maximum temperature attained was 2852.87 K with (SEP) of 1478955.24 Wm-2 for the 200W lamp. For the 100W lamp, the (SEP) obtained was 749347.9078 Wm-2 at 2489.14 K. Both temperatures, and even as low as 1250 K, were in agreement with Wien’s displacement law. The percentage estimation of visible spectrum in the radiation was about fourteen percent (14 %) while the rest was infra red radiation. This low visible light produced may be as a result of the non-ideal black body nature of the tungsten filament; and so, the incandescent lamp may be considered a quasi-black body.

Spectrophotometrically derived seawater CO2‐system assessments: Parameter calculations using pH do not require measurements at standard temperatures

AbstractThe temperature range of Earth's open‐ocean waters is roughly 0–30°C, yet our understanding of the seawater carbon dioxide (CO2) system is largely derived from analyses conducted within a narrow temperature range (e.g., laboratory temperature of 20°C or 25°C). Herein, we address two aspects of open‐ocean CO2‐system measurements and modeling: (1) a highly precise spectrophotometric technique is used to determine bicarbonate dissociation constants (K2) in seawater at temperatures as low as 3°C and (2) a cruise dataset uniquely including total scale pH measurements at two temperatures is used for CO2‐system internal consistency comparisons at 12°C and 25°C. Our pK2 parameterization (where pK = −log K) is applicable for broad ranges of salinity (20 ≤ SP ≤ 40) and temperature (3°C ≤ t ≤ 35°C). Our CO2‐system internal consistency evaluation (comparison of measured and calculated CO2‐system parameters) utilized data obtained during NOAA's 2021 West Coast Ocean Acidification Cruise: total alkalinity (TA), total dissolved inorganic carbon (DIC), pH measured at 25°C, and pH measured at 12°C (n = 265). Results demonstrate that, relative to calculations utilizing the TA, DIC pair, agreement between measured and calculated parameters is improved when either TA or DIC is paired with pH measurements at either temperature. Calculations of CO2 fugacity (fCO2) and aragonite saturation state (Ωar) using pH measurements made at 25°C or 12°C (paired with either TA or DIC) are statistically indistinguishable. Results also suggest that the temperature dependence of current CO2‐system dissociation constants need further refinement.

Systematic Characterization of Cow Manure Biochar and Its Effect on Salicornia herbacea L. Growth

This study investigated the potential of biochar as a sustainable material for waste utilization and carbon sequestration in soil. Biochar was prepared from cow manure (CM) and applied to the soil. Biochar was processed by subjecting CM to various temperature ranges (400 [CMB400], 550 [CMB550], and 700 °C [CMB700]) under nitrogen gas (allowed to flow to restrict oxygen), with residence time set to 3 h. The characteristics of the biochar produced at each temperature were analyzed. The experiment was conducted for approximately 15 weeks with the laboratory temperature maintained between 24 and 26 °C. The growth rate of plants was obtained by measuring their length weekly, starting 4 weeks after crop establishment. CMB550 exhibited the highest specific surface area (117.57 m2 g−1) and well-distributed pore size; therefore, it was mixed with the soil at a specific ratio and put in pots for the planting of Salicornia herbacea L. (glasswort) in the laboratory. The results demonstrated that adding biochar to soil increased plant growth and that the biochar could store organic carbon. In addition, an investigation of heavy metals demonstrated that samples with biochar had lower heavy metal concentrations in glasswort than those without because of the potential of biochar to adsorb heavy metals. By interacting with heavy metal ions in soil solution, the reactive sites and functional groups on the surface of biochar immobilize them and lessen their potentially detrimental effects on plant growth. Overall, biochar has the potential to be a valuable resource for waste management and environmental improvement.

Daily temperature fluctuation interacts with the mean temperature to increase the toxicity of a pyrethroid insecticide in a moth

Climate change complicates ecotoxicology studies because species responses to pesticides depend on temperature. Classically illustrated by the effect of constant laboratory temperatures, a recent review revealed that the toxicity of pesticides is also often increased by daily temperature fluctuations. Here, we investigated the combined effects of daily temperature fluctuation and mean temperature on the toxicity of two insecticides in the moth Spodoptera littoralis. Our study tested the toxicity of chlorpyrifos and deltamethrin on larvae of six experimental groups that crossed three treatments of daily temperature fluctuations (0, 5 or 10 °C) and two treatments of mean temperatures (25 or 33 °C). We showed that daily temperature fluctuation increased larval mortality induced by chlorpyrifos and deltamethrin. However, the response differed between the organophosphorus insecticide chlorpyrifos and the pyrethroid insecticide deltamethrin. The increase in chlorpyrifos toxicity by daily temperature fluctuation did not differ between mean temperatures of 25 and 33 °C. Remarkably, the increase in deltamethrin toxicity by daily temperature fluctuation was dependent on the crossed effects of the amplitude of daily fluctuation and mean temperature. This increase in deltamethrin toxicity occurred with a daily fluctuation of only 5 °C for larvae reared at 25 °C and a daily fluctuation of 10 °C in larvae reared at 33 °C. To confidently quantify the responses of insecticide toxicity to temperature, future ecotoxicology studies will have to evaluate the generality of the interaction between the effects of daily temperature fluctuation and mean temperature.

Modeling of an Integrated Traction Motor Protection System

Purpose. The article is devoted to the creation of traction motor protection by modern methods and means based on a programmable logic controller (PLC). Methodology. To simulate motor fault monitoring in laboratory conditions, magnetic field and temperature sensors were installed on a small powerful induction motor, and then the data obtained from the sensors in normal and overloaded motor modes were analyzed. Based on the research, protection methods were developed. Findings. Previously used simple motor protection systems based on components such as timers, contactors, electromagnetic switches, voltage and current transformers were slow and inaccurate, and had low sensitivity. However, the production of PLCs and their application in this industry has eliminated these problems. The intensive operation of motors as the main executive equipment requires the creation of modern automated protection systems to ensure their reliable and stable operation. Originality. The paper improves the method of protection of traction motors based on the use of programmable logic controllers. In addition to the voltage and current parameters, the proposed method involves monitoring the magnetic field. It also provides for the possibility of adjusting the protection response time. As a result, in the event of overload, short circuit, and other non-standard situations, the improved method provides the system with the ability to make more accurate and reliable decisions. Practical value. The TIA Portal software package has modeled a traction motor protection system by temperature and current and considered its practical application. To make such systems more effective, in the future, comprehensive protection systems based on the diagnostic state of the traction motor can be developed. In addition, an effective system can be created by providing SCADA control of the engines of several vehicles simultaneously.

Compressive and Split Tensile Strengths of Steel Fiber Reinforced Concrete Exposed to Temperature

Compressive and split tensile strengths of steel fiber reinforced concrete (SFRC) subjected to temperature (20, 100, 200, 400 and 600 oC) were experimentally investigated in this study. Four different volume percentages (0, 0.25, 0.5 and 0.75% by volume of concrete) of steel fibers were used. Concrete specimens were cured in water for 28 days and then allowed to dry for three days at laboratory temperature before subjected to heat for 2 hours in an electric furnace. After the completion of heating period, specimens were cooled down for 1 day at laboratory conditions and then tested for determining their compressive and split tensile strengths as well as ultrasonic pulse velocity (UPV). The relation between concrete strengths and temperature for steel fiber reinforced concrete (SFRC) were also discussed. The test results show that the compressive and split tensile strengths of steel fiber reinforced concrete are less affected by temperature as compared to those of control concrete (without fiber). The results of statistical analysis show a good linear relation between: 1) Compressive strength and temperature; 2) Split tensile strength and temperature for SFRC.

Spectrophotometric Determination of Remdesivir Using the Ion Pair Complex Method Using through Alizarin Red S Dye

The research included the development of a simple and practical spectroscopic method for the estimation of remdesivir (RDV) by the ion-pair method, which is based on the interaction of RDV with Alizarin Red S (ARS) at laboratory temperature. Using water as a medium for the reaction, a product Red in color was formed, with a linear relation ranging from 1 to 25 ?g/ml. It gave the highest absorption at wavelength 524 nm, and the complex completed its reaction after an hour, as the value of the sample was a relative standard deviation of no more than 1%, the recovery rate is 100.2429%, and high sensitivity to low concentrations, where she was the values of limit of detection, limit of quantitation were 0.0198, 0.0602 ?g/ml, respectively, detection limit of 0.0139 ?g/mL, and a quantitation limit of 0.0422 ?g/mL. The molar absorptivity is 51340.668 L/mol/cm, and Sandell?s sensitivity value is 0.0117 ?g.cm-2. The recovery values ranged from 99.3088% to 100.5184%, with a relative standard deviation not exceeding 0.7886% for RDV. The method was successfully applied for the estimation of pharmaceutical preparations using both direct and standard addition methods.. KEYWORDS :Alizarin red S, Ion pair, Remdesivir, Spectrophotometric estimation.

Insulin at the intersection of thermoregulation and glucose homeostasis

Mammals are protected from changes in environmental temperature by altering energetic processes that modify heat production. Insulin is the dominant stimulus of glucose uptake and metabolism, which are fundamental for thermogenic processes. The purpose of this work was to determine the interaction of ambient temperature induced changes in energy expenditure (EE) on the insulin sensitivity of glucose fluxes. Short-term and adaptive responses to thermoneutral temperature (TN, ∼28 °C) and room (laboratory) temperature (RT, ∼22 °C) were studied in mice. This range of temperature does not cause detectable changes in circulating catecholamines or shivering and postabsorptive glucose homeostasis is maintained. We tested the hypothesis that a decrease in EE that occurs with TN causes insulin resistance and that this reduction in insulin action and EE is reversed upon short term (<12h) transition to RT. Insulin-stimulated glucose disposal (Rd) and tissue-specific glucose metabolic index were assessed combining isotopic tracers with hyperinsulinemic-euglycemic clamps. EE and insulin-stimulated Rd are both decreased (∼50%) in TN-adapted vs RT-adapted mice. When RT-adapted mice are switched to TN, EE rapidly decreases and Rd is reduced by ∼50%. TN-adapted mice switched to RT exhibit a rapid increase in EE, but whole-body insulin-stimulated Rd remains at the low rates of TN-adapted mice. In contrast, whole body glycolytic flux rose with EE. This higher EE occurs without increasing glucose uptake from the blood, but rather by diverting glucose from glucose storage to glycolysis. In addition to adaptations in insulin action, ‘insulin-independent’ glucose uptake in brown fat is exquisitely sensitive to thermoregulation. These results show that insulin action adjusts to non-stressful changes in ambient temperature to contribute to the support of body temperature homeostasis without compromising glucose homeostasis.

Phenology and impact of abiotic factors with a temporal lag on the abundance of common crab spider, Xysticus cristatus (Clerck, 1757) (Araneae: Thomisidae) in the agroecosystems of Kashmir

ABSTRACT Xysticus cristatus is a Palearctic species, very abundant in the north-western Himalayas having a temperate climate. It is one of the predominant species in the agroecosystems of Kashmir. For a period of two years, we conducted a study on the population of Xysticus cristatus inhabiting the agroecosystems of Kashmir. A phenological study was conducted under field and laboratory conditions and temperature, rainfall, and humidity were monitored as indicators of population size. The spiders appear to have an annual reproductive cycle and a spring–summer stenochronous phenological pattern. Adult spiders emerge in spring, recruitment of spiders occurs in summer, they undergo overwintering in the immature stage and all stages of development show sequential phenological maxima. Under laboratory conditions, almost all spiders took VII instars to develop, and considerable variations were observed among all the instars. The abundance of Xysticus cristatus did not show any correlation with climatic variables at time 0, although there was a correlation with temporal lag. The best-adjusted correlation was found with a 3 month time lag, indicating that species require time to respond to changes in the environment.

Evaluation of the effects of lyophilization and post-reconstitution stability of plasma samples containing PT, APTT, and Fibrinogen parameters

Objective: To evaluate the effects of lyophilization and post-reconstitution stability of plasma samples containing PT (Prothrombin Time), aPTT (activated Partial Thromboplastin Time), and fibrinogen parameters. Research method: Experimental study was conducted on lyophilized plasma samples containing PT, aPTT, and fibrinogen parameters. The homogeneity of sample set before and after lyophilization was evaluated, then the stability of the sample set was assessed in variable time and temperature reservation conditions by Paired–samples t–test. Results: Plasma samples containing 3 parameters PT, aPTT and fibrinogen were not significantly affected by the lyophilization process, shown through repeated measurements with p-value of 0.912, 0.699 and 0.334 respectively. Lyophilized plasma samples after reconstitution are stored at -20°C to achieve stability for 8 weeks, at 2 - 8°C stable for 24 hours, at laboratory temperature stable for 8 hours with all PT, aPTT, and fibrinogen parameters. Conclusion: The freeze-drying process does not change the values of PT, aPTT, fibrinogen parameters in plasma samples, so it can be applied to produce coagulation proficiency testing samples by lyophilization. The reconstituted sample is stable in different time and reservation conditions, met the requierment of reservation condition of reconstituted sample. Key words: Lyophilization, reconstitution, PT, aPTT, fibrinogen.