Seasonal Temperature Fluctuations Research Articles

Multiple Lines of Evidence for Estimating NSZD Rates Overlying a Shallow LNAPL Source Zone

AbstractQuantitative methods of monitoring natural source zone depletion (NSZD) via biodegradation of petroleum hydrocarbons (PHC) are required to investigate source zone longevity and guide long‐term management of PHC impacted sites. Vadose zone NSZD processes can be monitored using analysis of surficial CO2 effluxes, soil‐gas gradients, and thermal gradients. This study describes an applied research and development program conducted at a former refinery site over a 4‐year period (2015 to 2019) on quantitative technologies for evaluation of NSZD of PHC light nonaqueous phase liquid (LNAPL) present within a shallow soil zone. A multiyear study using discrete CO2 efflux measurements from dynamic closed chambers was compared with estimates obtained using static traps and continuous monitoring using forced diffusion (FD) technology. Thermistor strings along a transect were used to monitor hourly thermal gradients and assess NSZD rates using the temperature gradient method. Discrete soil‐gas data were used to quantify the vertical oxygen gradient to estimate NSZD rates using the concentration gradient method (CGM). Results of discrete and continuous monitoring methods provide estimates of monthly NSZD rates that range seasonally from 80 to 1300 US gal/acre/year using radiocarbon corrected CO2 efflux method for decane (C10H22) equivalent, 120 to 1600 US gal/acre/year using CGM (for wet to dry conditions) and 400 to 2000 US gal/acre/year using the temperature gradient method. Both seasonal temperature and precipitation fluctuations contribute to variability in rates. Continuous methods are shown to provide for improved resolution of temporal variability and seasonal estimates, although discrete methods provide for improved spatial quantification.

Remote Geotechnical Monitoring of a Buried Oil Pipeline

Extensive but remote oil and gas fields in Canada and Russia require extremely long pipelines. Global warming and local anthropogenic effects drive the deepening of seasonal thawing of cryolithozone soils and enhance pathological processes such as frost heave, thermokarst, and thermal erosion. These processes lead to a reduction in the subgrade capacity of the soils, causing changes in the spatial position of the pipelines, consequently increasing the number of accidents. Oil operators are compelled to monitor the daily temperatures of unevenly heated soils along pipeline routes. However, they are confronted with the problem of separating anthropogenic heat losses from seasonal temperature fluctuations. To highlight heat losses, we propose a short-term prediction approach to a transformed multidimensional dataset. First, we define the temperature intervals according to the classification of permafrost to generate additional features that sharpen seasonal and permafrost conditions, as well as the timing of temperature measurement. Furthermore, linear and nonlinear uncorrelated features are extracted and scaled. The second step consists of selecting a training sample, learning, and adjusting the additive regression model. Forecasts are then made from the test sample to assess the accuracy of the model. The forecasting procedure is provided by the three-component model named Prophet. Prophet fits linear and nonlinear functions to define the trend component and Fourier series to define the seasonal component; the third component, responsible for the abnormal days (when the heating regime is changed for some reason), could be defined by an analyst. Preliminary statistical analysis shows that the subsurface frozen soils containing the oil pipeline are mostly unstable, especially in the autumn season. Based upon the values of the error metrics, it is determined that the most accurate forecast is obtained on a three-month uniform time grid.

A nonlinear model for resolving the temperature bias of branched glycerol dialkyl glycerol tetraether (brGDGT) temperature proxies

Branched glycerol dialkyl glycerol tetraethers (brGDGTs) are a class of ubiquitous, bacteria-derived lipid biomarkers in terrestrial and aquatic environments. Many studies have demonstrated the potential for brGDGTs as paelotemperature proxies, but the observed seasonal bias in brGDGT-inferred temperatures still remains poorly understood, particularly for Arctic or seasonally dry climates. Here we introduce a new physical framework for understanding variations in the methylation index of branched tetraethers (MBT) by explicitly modeling the production and preservation of brGDGTs for a bacterial population with an exponential rate dependence on temperature. The dependence of MBT ratios on temperature is predicted to be nonlinear, and thus has a different form from other empirically defined MBT models. We apply the model to understanding how the methylation index depends on not only the mean annual air temperature (MAAT) but also how it depends on the amplitude of the seasonal temperature cycle and the phase and amplitude of the soil moisture content. We performed mesocosm growth experiments using natural lake waters that confirm that the model correctly accounts for lower brGDGT production rates during cold seasonal temperatures. Comparing the new model predictions with global compilations of MBT’5Me and MBT’ data, we determine a new calibration of best fitting set of model coefficients that more accurately account for the expected physical constraints on MBT-type data. Our new results account naturally for the expected saturation of MBT’5Me and MBT’ at low and high temperatures, a bias of up to 5–7 °C in MAAT for high seasonal temperature fluctuations, and an additional bias of up to 1–3 °C in MAAT for strongly seasonal soil moisture fluctuations. Taken together, the 3 effects explain differences of up to 15 °C in inferred MAAT compared with traditional empirical models for MBT’5Me and MBT’ and results in improved mean squared errors for both. At MAAT above 18 °C, MBT’ temperature errors are lower than those of MBT’5Me, suggesting MBT’ may still be a useful proxy in some situations despite its added complexity. While we apply the framework only to global MBT’5Me and MBT’ proxy data, the physical framework can be adapted to other types of paleoproxies and may therefore be more widely applicable. Preliminary application of our model to the Pliocene North Sea Hank Core yields ∼1 °C cooler temperatures than a previous calibration and application to 130 kyr-long Chinese Loess Plateau records yields ∼4 °C warmer glacial and glacial stadial temperatures compared to previous calibration.

A novel artificial neural network model for forecasting electricity demand enhanced with population-weighted temperature mean and the unemployment rate

Precise electricity demand forecasting has principal significance in the energy production planning of the developing countries. Especially during the last decade, numerous recent methods have been utilized to predict the forthcoming electricity demand in different time resolutions accurately. This contribution presents a novel approach, which improves the forecasting of Turkey’s electricity demand in monthly time resolution. An artificial neural network model has been proposed with appropriate input features. Yearly-based gross demand shows approximately linear increment due to population increase and economic growth, while monthly-based gross demand indicates an oscillation due to the effect of seasonal temperature fluctuations. However, there is no clear linear relation between electricity demand and temperature; for the ideal case, it is the V-shaped curve around balance point temperature. Since temperature levels in each region of the country demonstrate a high variance even in the same time period, weighted average temperature point was calculated with respect to the population weights of the selected regions of Turkey. In order to fit a function for monthly oscillations, a linear function according to weighted average temperature point was created. Unemployment data was added to the training data set as an indicator of economic fluctuations. The mean absolute percentage errors of the model were calculated for training, validation, and testing as 3.77 %, 2.02 %, and 1.95 % respectively.

Radiative Cooling and Solar Heating Janus Films for Personal Thermal Management

Hot and cold seasonal temperature fluctuations pose a serious public health threat. Radiative thermal management has been shown to be an effective method for personal thermal management. However, the currently available materials cannot maintain human thermal comfort against the hot and cold seasonal temperature fluctuations, such as heating in cold weather or cooling in hot weather. Here, a Janus film that integrates the two opposite requirements of heating and cooling into one functional dual-mode film is fabricated. In cooling mode, the Al backing and embedded silicon dioxide (SiO2) microparticle can achieve a high solar reflectivity (∼0.85) and high IR emissivity (∼0.95) to induce a temperature drop of ∼2 °C. In contrast, the embedded carbon nanotubes (CNTs) can improve solar absorption (∼0.95) and induce a temperature increase of ∼7 °C. Owing to its radiative cooling and solar heating capability and compatibility with large-scale production, this Janus film is promising to bring new insights into the design of the next-generation functional textiles.

Major niche transitions in Pooideae correlate with variation in photoperiodic flowering and evolution of CCT domain genes.

The external cues that trigger timely flowering vary greatly across tropical and temperate plant taxa, the latter relying on predictable seasonal fluctuations in temperature and photoperiod. In the grass family (Poaceae) for example, species of the subfamily Pooideae have become specialists of the northern temperate hemisphere, generating the hypothesis that their progenitor evolved a flowering response to long days from a short-day or day-neutral ancestor. Sampling across the Pooideae, we found support for this hypothesis, and identified several secondary shifts to day-neutral flowering and one to short-day flowering in a tropical highland clade. To explain the proximate mechanisms for the secondary transition back to short-day-regulated flowering, we investigated the expression of CCT domain genes, some of which are known to repress flowering in cereal grasses under specific photoperiods. We found a shift in CONSTANS 1 and CONSTANS 9 expression that coincides with the derived short-day photoperiodism of our exemplar species Nassella pubiflora. This sets up the testable hypothesis that trans- or cis-regulatory elements of these CCT domain genes were the targets of selection for major niche shifts in Pooideae grasses.

Seasonal variations of diatoms in a low-latitude mountain lake: a case study from Douhu lake-Southeast China

In the scientific literature on diatom ecology whether temperature drives changes in diatom assemblage directly or indirectly remains a subject of debate. In order to clarify the relationship between temperature and diatom assemblage composition, we focused on a region with significant seasonal changes but without a freezing period. From March 2016 to March 2018, sediment trap samples were collected monthly to monitor the seasonal succession of diatoms in Douhu Lake, in subtropical southeast China. The results show that in 2016 the variations in abundance of Aulacoseira granulata and Aulacoseira ambigua followed an obvious seasonal pattern, corresponding to the seasonal variation in water and air temperature. In 2016, the thermophilic taxon A. granulata was dominant in the warm season, and in the cold season its abundance declined, while that of A. ambigua, a taxon better adapted to cooler conditions, increased relatively. In 2017, however, there was no such typical seasonal variation. In the cold season of 2017, A. granulata did not decline and there was no significant increase in the cold-preferring A. ambigua. This was related to the large drop in the lake level associated with human activity (substantial water extraction) that occurred during the winter of 2017, which disturbed the natural seasonal fluctuation in water temperature. Thus, in 2017, while air temperature followed the regular seasonal cycle, lake water temperature did not decrease significantly in winter, which allowed A. granulata to maintain a relatively high abundance in the cold season. From these results and an extensive survey of the literature, we conclude that water temperature, more than the seasonal succession, directly drives the fluctuation in abundance of these two Aulacoseira species.

Monitoring of Seasonal Variations in Ground Temperature

The paper considers the problem of monitoring seasonal changes in soil temperature in northern and mountainous areas in the light of ongoing climate changes. To study seasonal changes in soil temperature, a model site of the Moscow State University Meteorological Observatory was used with the ability to monitor air temperature, snow cover thickness, and ground freezing temperature and depth, which was a prototype of a system for monitoring the state of permafrost soils used in the Arctic and mountain territories. The paper presents the results of monitoring seasonal changes in soil temperature based on the results of numerical modeling of the penetration of seasonal fluctuations in soil temperature in 2014-2017 in MATLAB environment at the model site of the MSU Meteorological Observatory. The results of numerical simulation of the penetration of seasonal temperature fluctuations in the ground at the MSU meteorological site in 2014-2017 in the MATLAB environment are in good agreement with the thermometry data and, therefore, the developed calculation scheme shows fairly good simulation results. This makes it possible to use the calculation scheme to assess the thermal state of frozen soils and assess the stability of foundations and buildings and linear structures located on them in the conditions of the North and mountainous territories. Therefore, the presented methodology can serve as a good help for monitoring and preventing the destruction of the studied structures in the conditions of climate warming.

Effectiveness of two wastewater disinfection strategies for the removal of fecal indicator bacteria, bacteriophage, and enteric viral pathogens concentrated using dead-end hollow fiber ultrafiltration (D-HFUF)

Primary influent and final effluent samples were collected from wastewater treatment plants using either chlorination or ultraviolet (UV) disinfection biweekly for one year. Paired measurements were determined for fecal indicator bacteria (Escherichia coli and enterococci), cultivated bacteriophages (somatic, F+, and CB-390 coliphage and GB-124 Bacteroides phage), human-associated viral markers (human polyomavirus [HPyV] and crAssphage), enteric pathogens (adenovirus, noroviruses genogroups I and II) as well as total infectious enteric virus. To increase the probability of detecting low concentration targets, both primary (10L) and final effluent wastewater samples (40-100 L) were concentrated using a dead-end hollow-fiber ultrafilter (D-HFUF). Despite seasonal temperature fluctuations, concentration shifts of FIB, bacteriophages, human-associated viruses, and viral pathogens measured in primary influent samples were minimal, while levels of infectious enteric virus were significantly higher in the spring and fall (P range: 0.0003–0.0409). FIB levels measured in primary influents were 1–2 log10 higher than bacteriophage, human-associated viral markers (except crAssphage) and viral pathogens measured. FIB displayed the greatest sensitivity to chlorine disinfection, while crAssphage, adenoviruses and infectious enteric viruses were significantly less sensitive (P ≤ 0.0096). During UV treatment, bacteriophages F+ and GB-124 were the most resistant of the culturable viruses measured (P ≤ 0.001), while crAssphage were the most resistant (P ≤ 0.0124) overall. When UV lamps were inactive, infectious enteric viruses were significantly more resilient to upstream treatment processes than all other targets measured (P ≤ 0.0257). Similar to infectious enteric viruses and adenoviruses; GB-124, F+, and crAssphages displayed the highest resistance to UV irradiation, signaling a potential applicability as pathogen surrogates in these systems. The use of D-HFUF enhanced the ability to estimate removal of viruses through wastewater treatment, with the expectation that future applications of this method will be used to better elucidate viral behavior within these systems.

A wMel Wolbachia variant in Aedes aegypti from field-collected Drosophila melanogaster with increased phenotypic stability under heat stress.

SummaryMosquito‐borne diseases remain a major cause of morbidity and mortality. Population replacement strategies involving the wMel strain of Wolbachia are being used widely to control mosquito‐borne diseases. However, these strategies may be influenced by temperature because wMel is vulnerable to heat. wMel infections in Drosophila melanogaster are genetically diverse, but few transinfections of wMel variants have been generated in Aedes aegypti. Here, we successfully transferred a wMel variant (termed wMelM) originating from a field‐collected D. melanogaster into Ae. aegypti. The new wMelM variant (clade I) is genetically distinct from the original wMel transinfection (clade III), and there are no genomic differences between wMelM in its original and transinfected host. We compared wMelM with wMel in its effects on host fitness, temperature tolerance, Wolbachia density, vector competence, cytoplasmic incompatibility and maternal transmission under heat stress in a controlled background. wMelM showed a higher heat tolerance than wMel, likely due to higher overall densities within the mosquito. Both wMel variants had minimal host fitness costs, complete cytoplasmic incompatibility and maternal transmission, and dengue virus blocking under laboratory conditions. Our results highlight phenotypic differences between Wolbachia variants and wMelM shows potential as an alternative strain in areas with strong seasonal temperature fluctuations.

УСТРОЙСТВО ЗАЩИТЫ КРОВЕЛЬНЫХ ПОКРЫТИЙ ЭКСПЛУАТИРУЕМЫХ ЗДАНИЙ ДЛЯ ЮЖНЫХ КЛИМАТИЧЕСКИХ РЕГИОНОВ

The article considers constructive and technological solutions for the protection of roofing coverings of operated buildings in conditions of high natural and climatic temperature effects. Their use contributes to the creation of comfortable living conditions in the premises of the upper floors, both in summer and winter. During a long period of operation, there is a problem of maintaining the physical and mechanical characteristics of building envelopes in accordance with the established design requirements. Their changes can be caused by seasonal temperature fluctuations that occur, which entails a change in the parameters of the microclimate in the room. The device of protective structural and technological elements and measures prevents the violation of the conditions for normal operation of the premises of the upper floors of buildings.

Nitrogen removal performance of anammox immobilized fillers in response to seasonal temperature variations and different operating modes: Substrate utilization and microbial community analysis

Four anaerobic ammonium oxidation (anammox) immobilized filler reactors (R1: 33 °C-normal, R2: seasonal temperature-normal, R3: seasonal temperature-feast, R4: seasonal temperature-starvation) were established to study the response of anammox immobilized fillers to seasonal temperature changes and different operating modes. The results showed that the anammox immobilized filler could better adapt to the seasonal temperature drop and maintain the activity potential by adjusting the hydraulic retention time (HRT). During the temperature rise phase, R2 activity increased rapidly with the highest nitrogen removal rate reaching 1.26 kgN·(m3·d)−1, which was equivalent to control sample R1 (1.33 kgN·(m3·d)−1). However, feasting and famine conditions severely impaired anammox performance and changed stoichiometric ratios; feasting, in particular, significantly lowered the nitrogen removal potential of R3. The specific anammox activity of R2, R3 and R4 was 92.2%, 52.6% and 67.9%, respectively, that of R1, respectively, where the accumulation of functional bacteria was the reason for the higher activity of R2. Degradation kinetics and NO2−-N inhibition curves showed that R3 was less sensitive to high concentrations of NH4+–N, while R4 responded earlier to low concentrations of NH4+–N, and the reduction of IC50 at low temperature was the reason for the inhibition of R3 activity. Furthermore, seasonal temperature fluctuations had little effect on the microbial community structure but had a considerable impact on bacteria abundance. The anammox functional bacteria Candidatus Kuenenia was found to be the dominant genus in R1-R4; however, the relative abundance of most bacteria, including anammox bacteria, decreased in R3, while the proportion of fermentation bacteria and denitrifying bacteria increased in R4. These findings highlight the necessity of rational regulation of HRT for the adaptation of anammox immobilized fillers to seasonal temperature changes, which could enhance our understanding of the synergistic effect of seasonal temperature changes and different operating modes on nitrogen removal.

Plant Species Turnover on Forest Gaps after Natural Disturbances in the Dinaric Fir Beech Forests (Omphalodo-Fagetum sylvaticae)

We studied species turnover and changes of ecological conditions and plant strategies on forest gaps created by natural disturbances (sleet, windthrow). We studied five forest gaps and a control plot within in the Dinaric silver fir-beech forest in the southern part of Slovenia. Forest gaps varied in age and size. The total number of recorded species in gaps was 184, with the highest number (106) at the largest forest gap and with the 58 species at the control locality in a juvenile beech forest. Forest gaps were predominantly colonised mostly by species of understory, forest margins, and forest clearings. The species presented in all forest gaps are representatives of the understory of beech forests. Species colonising forest gaps prefer habitats with more sunlight, medium wet to dry soil, and are tolerant to high daily and seasonal temperature fluctuations. In gaps, the community of plant species has a competitive strategy, which is also complemented with a stress-tolerator strategy. We determined that a forest gap represents a significant habitat patch, especially for those plant species which were not present there before.

Combining horizontal evacuated tubes with booster mirror reflector to achieve seasonal reverse output: Technical and experimental investigation

Owing to seasonal fluctuations in solar radiation resources and ambient air temperature, stationary solar collectors have higher output in summer and lower output in winter. However, seasonal heating demand and hot water usage follows an opposite pattern, resulting in insufficient heating in winter and the risk of overheating in summer, reducing the feasibility of solar thermal technology. In this study, a new configuration that combines horizontal evacuated tubes with a mirror reflector was developed to achieve seasonal reverse performance: high performance in winter and low performance in summer. In contrast to conventional collectors, the collector plane of this new module was inversely inclined, pointing to the solar altitude angle on the summer solstice. Together with the bottom mirror reflector, the normal vector of the composed aperture plane was designed to point to the solar altitude angle on the winter solstice. Through experimental and numerical studies, we found that the standardized thermal efficiency of the new module on the winter solstice was comparatively high because it can be regarded as a concentrating collector with a concentration ratio of 0.77. On the summer solstice, the thermal efficiency was extremely reduced due to 100% self-shading of the collector plane. Based on the idea of overcoming the seasonal instability of renewable resources, this designed solar module is expected to enhance the competitiveness of solar heating technology, especially in the decentralized clean heating market.

Influence of Seasonal Temperature Variations on Electromagnetic Characteristics of Frozen Soils by the Degree of Thawing and Freezing

Seasonal temperature fluctuations in frozen soils cause changes in their ice content which are accompanied by resistivity changes and electromagnetic emission. This study examines the periodic seasonal variation in apparent resistivity of permafrost soils based on field measurements of the surface impedance in the 100–1000 kHz frequency range. The characteristic changes in soil temperature and apparent resistivity associated with particular time periods are presented. The data show that the apparent resistivity values are consistent with the degree of soil freezing. Rapid freezing or thawing of the active layer causes electromagnetic emission in frozen soils. These features can be used to monitor and predict changes in permafrost conditionsunder climatic or anthropogenic impacts.

Influence of temperature on anammox reaction and microbial diversity in a bio-carriers reactor under mainstream conditions

The hypersensitive with seasonal temperature fluctuation of anaerobic ammonium-oxidizing bacteria has usually limited the actual implementation of the anammox process. Thus far, temperature influences on anammox reaction and microbial consortium structure under mainstream conditions was not thoroughly studied. In this study, hydrazine dehydrogenase (HDH) activity and specific activity of anammox bacteria were studied in a 10 L bench scale Continuous Anammox Bio-carrier Reactor (CABR) at nitrogen loading rates of 0.2–0.4 kg N/m3 ⋅ d and a temperature range from 18 °C to 35 °C. At 35 °C, CABR achieved nitrogen removal efficiency above 94% and the nitrogen removal rate of 0.25–0.3 kg N/m3 ⋅ d. When the temperature decreased to 18 °C, the nitrogen removal efficiency and nitrogen removal rate reduced 62.2% and 0.1 kg N/m3 ⋅ d, respectively due to 3.5-folds reduced HDH activity. At 10 °C, specific activity of anammox bacteria declined to 0.02 g N/gVSS ⋅ d, which was 1/7 of that at 35 °C. Anammox reaction could recover when temperature increased to 23 °C with NRE of 85%. It revealed that temperature directly impacted HDH activity was a key parameter influencing anammox metabolism. Activation energy (Ea) calculated for specific activity of anammox bacteria at 10–18 °C and 10–35 °C were approximately 120 kJ/mol and 57 kJ/mol, respectively. Also, 16S rDNA sequencing results revealed that C. Jettenia well adapted to temperature-varying conditions, which implied the CABR could be a favorable process for anammox applications with seasonal temperature change in sub-tropical and tropical climate regions.

Intensified paraglacial slope failures due to accelerating downwasting of a temperate glacier in Mt. Gongga, southeastern Tibetan Plateau

Abstract. Topographic development via paraglacial slope failure (PSF) represents a complex interplay between geological structure, climate, and glacial denudation. Southeastern Tibet has experienced amongst the highest rates of ice mass loss in High Mountain Asia in recent decades, but few studies have focused on the implications of this mass loss on the stability of paraglacial slopes. We used repeat satellite- and unpiloted aerial vehicle (UAV)-derived imagery between 1990 and 2020 as the basis for mapping PSFs from slopes adjacent to Hailuogou Glacier (HLG), a 5 km long monsoon temperate valley glacier in the Mt. Gongga region. We observed recent lowering of the glacier tongue surface at rates of up to 0.88 m a−1 in the period 2000 to 2016, whilst overall paraglacial bare ground area (PBGA) on glacier-adjacent slopes increased from 0.31 ± 0.27 km2 in 1990 to 1.38 ± 0.06 km2 in 2020. Decadal PBGA expansion rates were ∼ 0.01 km2 a−1, 0.02 km2 a−1, and 0.08 km2 in the periods 1990–2000, 2000–2011, and 2011–2020 respectively, indicating an increasing rate of expansion of PBGA. Three types of PSFs, including rockfalls, sediment-mantled slope slides, and headward gully erosion, were mapped, with a total area of 0.75 ± 0.03 km2 in 2020. South-facing valley slopes (true left of the glacier) exhibited more destabilization (56 % of the total PSF area) than north-facing (true right) valley slopes (44 % of the total PSF area). Deformation of sediment-mantled moraine slopes (mean 1.65–2.63 ± 0.04 cm d−1) and an increase in erosion activity in ice-marginal tributary valleys caused by a drop in local base level (gully headward erosion rates are 0.76–3.39 cm d−1) have occurred in tandem with recent glacier downwasting. We also observe deformation of glacier ice, possibly driven by destabilization of lateral moraine, as has been reported in other deglaciating mountain glacier catchments. The formation, evolution, and future trajectory of PSFs at HLG (as well as other monsoon-dominated deglaciating mountain areas) are related to glacial history, including recent rapid downwasting leading to the exposure of steep, unstable bedrock and moraine slopes, and climatic conditions that promote slope instability, such as very high seasonal precipitation and seasonal temperature fluctuations that are conducive to freeze–thaw and ice segregation processes.

The Response of Tomato Fruit Cuticle Membranes Against Heat and Light.

Two important biophysical properties, the thermal and UV-Vis screening capacity, of isolated tomato fruit cuticle membranes (CM) have been studied by differential scanning calorimetry (DSC) and UV-Vis spectrometry, respectively. A first order melting, corresponding to waxes, and a second order glass transition (Tg) thermal events have been observed. The glass transition was less defined and displaced toward higher temperatures along the fruit ripening. In immature and mature green fruits, the CM was always in the viscous and more fluid state but, in ripe fruits, daily and seasonal temperature fluctuations may cause the transition between the glassy and viscous states altering the mass transfer between the epidermal plant cells and the environment. CM dewaxing reduced the Tg value, as derived from the role of waxes as fillers. Tg reduction was more intense after polysaccharide removal due to their highly interwoven distribution within the cutin matrix that restricts the chain mobility. Such effect was amplified by the presence of phenolic compounds in ripe cuticle membranes. The structural rigidity induced by phenolics in tomato CMs was directly reflected in their mechanical elastic modulus. The heat capacity (Cprev) of cuticle membranes was found to depend on the developmental stage of the fruits and was higher in immature and green stages. The average Cprev value was above the one of air, which confers heat regulation capacity to CM. Cuticle membranes screened the UV-B light by 99% irrespectively the developmental stage of the fruit. As intra and epicuticular waxes contributed very little to the UV screening, this protection capacity is attributed to the absorption by cinnamic acid derivatives. However, the blocking capacity toward UV-A is mainly due to the CM thickness increment during growth and to the absorption by flavone chalconaringenin accumulated during ripening. The build-up of phenolic compounds was found to be an efficient mechanism to regulate both the thermal and UV screening properties of cuticle membranes.

Calculation of temperature waves in kurums

The article indicates the relevance of the study of heat transfer processes in kurums. Boundary value problems of vertical temperature change in kurums and in the underlying rock base are solved, when the temperature on the surface of kurums changes according to a given periodic law, which simulates daily and seasonal temperature fluctuations. The cases when the rock base is a heat-conducting medium and permafrost are considered. Some regularities of temperature propagation along the depth are revealed.

Seasonal effects on locomotor and feeding rhythms in indoor cats

Different synchronizers can modify daily rhythms during an annual cycle. Nevertheless, the fluctuation of these external factors is often ignored in studies on cat locomotor activity and feeding rhythms, thereby focusing on one single season. To fill this gap, the activity and feeding rhythms of six cats living in a research cattery, receiving natural daylight, were monitored during 3 weeks for each season. Although under minimal influence of seasonal fluctuations in ambient temperature and humidity, the cats showed maxima in daily covered distance during spring and autumn, and minima during winter. The activity and feeding rhythms followed 24-hour periodicity during all seasons and bimodality was detected, with decreased covered distance and food intake around midnight and midday. These daily rhythm troughs were robust and stable across seasons, whereas the inter-seasonal differences in activity level resided in the timing of daily peaks. However, the daily eating pattern was less affected by seasonal variations. Human interactions systematically enhanced locomotor activity and food consumption at the same time for each season, whereas spontaneous peaks of feeding and activity rose during the twilight times according to the season, confirming the crepuscular nature of the species. Human presence and attention seem responsible for more diurnal patterns in the studied cats. This study demonstrates that natural seasonal daylight fluctuations modulate the locomotor and feeding rhythms of indoor cats.