Monthly Temperature Variation Research Articles

Shark critical life stage vulnerability to monthly temperature variations under climate change

In a 10-month experimental study, we assessed the combined impact of warming and acidification on critical life stages of small-spotted catshark (Scyliorhinus canicula). Using recently developed frameworks, we disentangled individual and group responses to two climate scenarios projected for 2100 (SSP2-4.5: Middle of the road and SSP5-8.5: Fossil-fueled Development). Seasonal temperature fluctuations revealed the acute vulnerability of embryos to summer temperatures, with hatching success ranging from 82% for the control and SSP2-4.5 treatments to only 11% for the SSP5-8.5 treatment. The death of embryos was preceded by distinct individual growth trajectories between the treatments, and also revealed inter-individual variations within treatments. Embryos with the lowest hatching success had lower yolk consumption rates, and growth rates associated with a lower energy assimilation, and almost all of them failed to transition to internal gills. Within 6 months after hatching, no additional mortality was observed due to cooler temperatures.

Thermoregulatory function and sexual dimorphism of the throat sack in Helmeted Guineafowl (Numida meleagris) across Africa

The responses of ground-dwelling birds to heat and cold stress encompass a variety of behavioural, physiological and even morphological mechanisms. However, the role of glabrous skin in this respect has been marginally addressed so far. The Helmeted Guineafowl (Numida meleagris) is a landfowl distributed across Sub-Saharan Africa with eight traditionally recognised extant subspecies. Among the most prominent morphological traits underlying intraspecific variability are size and pigmentation of the bare throat skin (or sack), which might be related to the different habitats and environmental conditions across its wide range. In order to explore the Helmeted Guineafowl range-wide sack variation and pigmentation in relation to thermoregulation and sexual signalling, we collected morphometric and environmental information for N. m. coronata integrating field data with the inspection of photographic material encompassing seven subspecies and environmental information from their habitats. Field data evidenced that sack size was significantly correlated with ambient temperature, thus pointing to a likely involvement of the throat sack in thermoregulation. When the pictorial data from all subspecies were pooled, sack size correlated negatively with biomass, rainfall and humidity, while a positive correlation was found with annual solar irradiation. Sack size correlated positively with monthly temperature variation among the blue-throated subspecies from southern Africa as opposed to the black-throated subspecies ranging north to Zambia and Mozambique. Still, in this latter group the sack was often larger during winter months, possibly to maximise solar radiation absorbance. Noteworthy, sack size was related to sex dimorphism in two subspecies. Sack morphology and colour in the Helmeted Guineafowl likely modulate body temperature by evaporative cooling or heating upon needs, but in some subspecies it is also seemingly related to sexual signalling. Additional studies are needed to fully understand the multifunctionality of this important morphological feature in this species.

Correlation of Ambient Temperature With Feedlot Cattle Morbidity and Mortality in the Texas Panhandle.

Anecdotal data would suggest that weather patterns influence beef cattle health in feedyards, and cattle producers often associate the seasonality of some illnesses with changes in environmental temperatures. However, to our knowledge, there is little information from large-scale feeding operations and precision weather stations that establishes a link or lack thereof between weather patterns and cattle health. Additionally, we are unaware of any studies correlating other weather parameters with animal health data. Therefore, the objective of this study was to test for associations between monthly temperature variation and animal morbidity/mortality in feedlots in the Texas Panhandle. Weather data was collected from a Texas Tech University Mesonet weather station in close proximity to 19 beef cattle feedyards in the Texas Panhandle. Additionally, near real-time morbidity and mortality data was collected from those yards from 2015 to 2018. These data document a seasonal pattern relative to cattle morbidity and mortality with most health events occurring from November to January. This pattern is differentiated when comparing morbidity and mortality by listed causation (e.g., respiratory, digestive, other), and the majority of deaths over the entire time course were attributed to respiratory disease. Most cattle morbidity was documented in the winter months, most of which were classified as respiratory disorders. Additionally, an increase in health events was observed as the population of the feedyard increased. However, the overall effects of ambient temperature on cattle health were minimal and the two may not be causally linked. The initial overview of the relationships documented in this manuscript may warrant further stratification and exploration.

Detection of temperature variability and trends in the lower troposphere over Delhi: A study of joint influence of ENSO and Land use/ Land cover during 1980–2015

A study of radiosonde observations for temperature at 850 hPa over Delhi for a period of 35 years was conducted. The influence of atmospheric oscillations and geophysical events like El Niño‐Southern Oscillation (ENSO) on tropospheric temperature variability showed indicative trends for changing urban climate in Delhi. The inter‐annual variation in surface temperature and its relationship with land use changes and land cover changes (LULCC) was also examined. LULCC and urban expansion into peripheral areas of Delhi (towards the West, North, North‐West and South) at the cost of agricultural and wasteland was found to be extensive. The upper range of the surface temperature has shifted by ~6°C. The post‐monsoon and winter months from November to February have experienced a considerable increase in the average temperature in the period examined. The monsoon months from June to September have undergone cooling of ~0.5°C–1°C at 850 hPa. An inverse relationship exists between the Southern Oscillation Index (SOI) and the monthly averaged temperature. The temperature of the atmosphere over Delhi at 850 hPa has increased only marginally (~ 0.3°C) for the time period 1980–2015. Bi‐modal peaks were the most peculiar features observed in mean monthly temperature variation during 2000–2009.

Temporal Trends and Temperature-Related Incidence of Electrical Storm: The TEMPEST Study (Temperature-Related Incidence of Electrical Storm).

The occurrence of ventricular tachyarrhythmias seems to follow circadian, daily, and seasonal distributions. Our aim is to identify potential temporal patterns of electrical storm (ES), in which a cluster of ventricular tachycardias or ventricular fibrillation, negatively affects short- and long-term survival. The TEMPEST study (Circannual Pattern and Temperature-Related Incidence of Electrical Storm) is a patient-level, pooled analysis of previously published data sets. Study selection criteria included diagnosis of ES, absence of acute coronary syndrome as the arrhythmic trigger, and ≥10 patients included. At the end of the selection and collection processes, 5 centers had the data set from their article pooled into the present registry. Temperature data and sunrise and sunset hours were retrieved from Weather Underground, the largest weather database available online. Total sample included 246 patients presenting with ES (221 men; age: 65±9 years). Each ES episode included a median of 7 ventricular tachycardia/ventricular fibrillation episodes. Fifty-nine percent of patients experienced ES during daytime hours (P<0.001). The prevalence of ES was significantly higher during workdays, with Saturdays and Sundays registering the lowest rates of ES (10.4% and 7.2%, respectively, versus 16.5% daily mean from Monday to Friday; P<0.001). ES occurrence was significantly associated with increased monthly temperature range when compared with the month before (P=0.003). ES incidence is not homogenous over time but seems to have a clustered pattern, with a higher incidence during daytime hours and working days. ES is associated with an increase in monthly temperature variation. https://www.crd.york.ac.uk. Unique identifier: CRD42013003744.

Exploring the universal ecological responses to climate change in a univoltine butterfly.

Animals with distinct life stages are often exposed to different temperatures during each stage. Thus, how temperature affects these life stages should be considered for broadly understanding the ecological consequences of climate warming on such species. For example, temperature variation during particular life stages may affect respective change in body size, phenology and geographic range, which have been identified as the "universal" ecological responses to climate change. While each of these responses has been separately documented across a number of species, it is not known whether each response occurs together within a species. The influence of temperature during particular life stages may help explain each of these ecological responses to climate change. Our goal was to determine if monthly temperature variation during particular life stages of a butterfly species can predict respective changes in body size and phenology. We also refer to the literature to assess if temperature variability during the adult stage influences range change over time. Using historical museum collections paired with monthly temperature records, we show that changes in body size and phenology of the univoltine butterfly, Hesperia comma, are partly dependent upon temporal variation in summer temperatures during key stages of their life cycle. June temperatures, which are likely to affect growth rate of the final larval instar, are important for predicting adult body size (for males only; showing a positive relationship with temperature). July temperatures, which are likely to influence the pupal stage, are important for predicting the timing of adult emergence (showing a negative relationship with temperature). Previous studies show that August temperatures, which act on the adult stage, are linked to range change. Our study highlights the importance of considering temperature variation during each life stage over historic time-scales for understanding intraspecific response to climate change. Range edge studies of ectothermic species that have annual life cycles, long time-series occurrence data, and associated temperature records (ideally at monthly resolutions) could be useful model systems for intraspecific tests of the universal ecological responses to climate change and for exploring interactive effects.

Effects of temperature and gonadal growth on the lysozyme level of immune tissues in the male and female Caspian kutum (Rutilus frisii kutum )

Lysozyme levels in the head kidney, spleen and liver tissues of the male and female Caspian kutum (Rutilus frisii kutum) were measured under monthly temperature variations and gonadal growth. The lysozyme content in all tissues of the male and female of the Caspian kutum showed almost a significant decreasing trend from October to March, coinciding with the lowest sea surface temperature and afterwards, it increased in April and May. In vitellogenic stage of the ovarian growth, the lysozyme level decreased in all three tissues and then increased significantly in the spawning stage. Over testicular growth, lysozyme level showed no remarkable variations from the early maturing to developed stages but increased in the spermiation stage. The regularity of lysozyme level in both sexes of the Caspian kutum was liver>spleen>head kidney. The effectiveness ratio (partial Eta2) of temperature and gonadal growth in the lysozyme variations showed that temperature factor was more highlight than gonadal growth. In conclusion, the liver similar to the kidney and spleen plays an essential role against pathogen as an organ of lysozyme producing in the Caspian kutum. In addition, the female lysozyme level was higher than the male in all studied tissues.

Investigation on Hourly and Monthly Thermal Comfort in the Humid Tropics of Malaysia

Investigations on hourly and monthly indoor neutral temperature variations in the humid tropics are limited in literature. In Malaysia, the variation of hourly outdoor mean temperature is slightly higher than the monthly mean temperature. Consequently, this leads to the hypothesis that the variation of hourly neutral temperatures might be higher than the monthly neutral temperatures. Understanding the impact of hourly and monthly temperature variation on thermal comfort will certainly provide the design direction of future indoor environments. In this study, extensive measurements from residential buildings were used to investigate the observed variation. Linear regression and Griffiths methods were explored for analyzing the results. There was almost no variation on hourly and monthly neutral temperatures within the range under study. Further research is highly recommended due to the limited data collection and the limitations of the employed methods. It is highly advised to further investigate the hourly temperature variation on thermal comfort during nighttime and early morning. This is for an accurate interpretation of the results.

Carbon emission associated with respiration and calcification of nine gastropod species from the intertidal rocky shore of Western Europe

Intertidal rocky shores are characterized by vertical zonation that results from the interplay between environmental conditions, organism physiology, and species interactions. Metabolism of intertidal organisms is highly variable between species and it changes with vertical position along the intertidal gradient. The present study aimed to quantify the carbon metabolism of nine intertidal rocky shore gastropods, in order to clarify their respective roles in carbon production during emersion and immersion. The influences of monthly temperature variation and tidal level were tested for each species. Analyses were performed in the laboratory using the infrared gas analyzer method for measuring aerial respiration rates, and the dissolved inorganic carbon and total alkalinity technique for measuring aquatic respiration rate and calcification. Hourly carbon fluxes were calculated for the mean annual temperature of 13 °C measured in both air and underwater in the study area. Respiration rates were similar for emersion (8–25 μmol CO2 g AFDW−1 h−1) and immersion (10–23 μmol DIC g AFDW−1 h−1). For all species, underwater respiration fluxes were more influenced by monthly temperature variation than by air fluxes, probably as an adaptation to the rapid changes occurring during emersion. Calcification was an important factor influencing annual carbon fluxes for all studied species; every species showed different calcification rates according to its size and position on the intertidal zone. Annual carbon emissions were calculated using the mean immersion/emersion time of each species. Intertidal gastropod carbon emission was primarily influenced by body biomass and their vertical position within the intertidal zone.

Local adaptation and evolutionary potential along a temperature gradient in the fungal pathogen Rhynchosporium commune

To predict the response of plant pathogens to climate warming, data are needed on current thermal adaptation, the pathogen's evolutionary potential, and the link between them. We conducted a common garden experiment using isolates of the fungal pathogen Rhynchosporium commune from nine barley populations representing climatically diverse locations. Clonal replicates of 126 genetically distinct isolates were assessed for their growth rate at 12°C, 18°C, and 22°C. Populations originating from climates with higher monthly temperature variation had higher growth rate at all three temperatures compared with populations from climates with less temperature fluctuation. Population differentiation in growth rate (QST) was significantly higher at 22°C than population differentiation for neutral microsatellite loci (GST), consistent with local adaptation for growth at higher temperatures. At 18°C, we found evidence for stabilizing selection for growth rate as QST was significantly lower than GST. Heritability of growth rate under the three temperatures was substantial in all populations (0.58–0.76). Genetic variation was lower in populations with higher growth rate at the three temperatures and evolvability increased under heat stress in seven of nine populations. Our findings imply that the distribution of this pathogen is unlikely to be genetically limited under climate warming, due to its high genetic variation and plasticity for thermal tolerance.

Reconstructing temporal patterns of snow avalanches at Lago del Desierto,southern Patagonian Andes

Snow avalanches recurrently cause substantial damage to infrastructure and losses in human lives in mountainous environments around the world. Densely populated regions have suffered more intensely the destructive forces of avalanches; however, settlers of these regions have developed tools to mitigate avalanche risk, including avalanche hazard maps. To design detailed hazard maps, accurate information on avalanche runout and frequency is necessary. In areas where avalanches are mostly undocumented, like in the Andes, dendrochronological methods become a valuable tool for reconstructing spatio-temporal avalanche patterns. At Lago del Desierto (southern Patagonian Andes, Argentina), trees from nine avalanche tracks were sampled. Nothofagus pumilio, a winter deciduous broad-leaved tree, was sampled in all cases. Avalanche activity is recognized based on the presence of scars, changes in stem eccentricity, reaction wood and abrupt growth changes. A rating system was used to define the relative importance of each tree-ring indicator in the reconstructed chronology of events. According to this chronology, widespread avalanche activity on the slope was found for the years 1918, 1930, 1931, 1971, 1995 and 1998. Superposed Epoch Analysis indicated that total monthly precipitation during the three snowiest months from May to October of 1971, 1995 and 1998 (years for which climatic data exists for validation) was significantly greater than for years without large avalanche activity. In contrast, no significant correlations were found between monthly temperature variations and years with large avalanche activity on the slope. Atmospheric circulation patterns associated with years of major avalanche activity show features typically observed during the cold phase of the El Niño–Southern Oscillation cycle, i.e. La Niña. For those cases, results also show an increase in the westerlies across the South Pacific and southern South America, resulting in both higher precipitation and stronger winds over the study area that favor snow avalanche episodes. We point out the need of a more systematic sampling strategy in order to reconstruct spatial avalanche patterns in the southern Andes, which are a complement of temporal patterns to design hazard maps.

Evaluating the impact of task demands and block resolution on the effectiveness of pixel-based visualization

Pixel-based visualization is a popular method of conveying large amounts of numerical data graphically. Application scenarios include business and finance, bioinformatics and remote sensing. In this work, we examined how the usability of such visual representations varied across different tasks and block resolutions. The main stimuli consisted of temporal pixel-based visualization with a white-red color map, simulating monthly temperature variation over a six-year period. In the first study, we included 5 separate tasks to exert different perceptual loads. We found that performance varied considerably as a function of task, ranging from 75% correct in low-load tasks to below 40% in high-load tasks. There was a small but consistent effect of resolution, with the uniform patch improving performance by around 6% relative to higher block resolution. In the second user study, we focused on a high-load task for evaluating month-to-month changes across different regions of the temperature range. We tested both CIE L*u*v* and RGB color spaces. We found that the nature of the change-evaluation errors related directly to the distance between the compared regions in the mapped color space. We were able to reduce such errors by using multiple color bands for the same data range. In a final study, we examined more fully the influence of block resolution on performance, and found block resolution had a limited impact on the effectiveness of pixel-based visualization.

Seasonal Variation in Hemoglobin A1c: Is It the Same in Both Hemispheres?

There are several reports from locations in the northern hemisphere of seasonal variation in hemoglobin A1c (HbA1c) levels with higher values noted in the cooler months. The variation has been attributed to holiday seasons, temperature differences, and changes in diet. This article describes the seasonal variation in both hemispheres and in a country on the equator with minimal temperature variation. The mean and median HbA1c by month was calculated for a maximum of 2 years for HbA1c data from the different locations: Edmonton and Calgary, Canada; Singapore; Melbourne, Australia; and Marshfield, Wisconsin. The mean monthly temperature for each location was found from available meteorological information. In both northern and southern hemispheres, the HbA1c was higher in cooler months and lower in the warmer months. In Singapore, where there is minimal temperature variation, there is also minimal variation in HbA1c values over the year. The difference in HbA1c over a year appears to be related to the difference in temperature. Hemoglobin A1c is higher in cooler months and lower in the warmer months in both hemispheres. In a country with minimal monthly temperature variation, there is only minimal variation in HbA1c values through the year. In all locations, the mean and median HbA1c declined over the study period, possibly due to better glycemic control of patients with diabetes or an increase in use of HbA1c as a screening test for diabetes or a combination of both.

Epistaxis: Are temperature and seasonal variations true factors in incidence?

To investigate the previously documented inverse association between ambient temperature and presentation rates for patients with epistaxis and seasonal variation of emergency presentation rates for patients with epistaxis. A retrospective analysis of all consecutive emergency patients with epistaxis presenting to hospital from the community over a five-year period, 1997-2002 (1830 days), including those who required admission to hospital with epistaxis over the same period. Patients in whom there was a clear aetiology for the epistaxis (traumatic, recurrent, iatrogenic, coagulopathic and hypertensive) were excluded. A tertiary referral centre in south-west London serving a population in excess of 2.8 million. A retrospective analysis of all patients presenting or admitted to St George's Hospital with epistaxis over a five-year period. Daily ambient temperature readings from London Heathrow airport were recorded for the same period. Presentations were correlated with monthly temperature variations and the month itself. Statistical analysis with Pearson's correlation coefficient was performed. 1373 patients with epistaxis presented to our department, of whom 386 (28.1 per cent) were admitted to hospital. No correlation is seen between ambient temperature and presentation rate for patients with epistaxis. No seasonal preponderance is noted for presentation rate (Pearson r = 0.160, p = 0.221) in this series. To our knowledge, this is the largest study to date examining ambient temperature association and epistaxis, and the first to investigate presentation rate in place of admission rate. We feel that the exclusion of all patients with epistaxis not admitted to hospital introduces a bias. In this series, there is no correlation between ambient temperature, seasonal preponderance, presentation rate or admission rate for patients with epistaxis. This is contrary to previously reported findings. We do not support the view that there is a relationship between epistaxis and temperature or seasonal variation. This contradicts the current belief that incidence of epistaxis displays seasonality, and has implications for the allocation of resources for healthcare provision within ENT departments.

Impact of global warming on the growing cycles of three forage systems in upland areas of southeastern France

The simulations supplied by a combination of a global climate model and a weather generator allowed the creation of two climate scenarios including an increase and/or monthly variations in temperature for the 2070-2100 horizon, which were compared with two currently available series (1961-1990 and 1990-2000). Three forage systems applied in upland areas of southern France were simulated using the STICS model (silage maize, perennial alfalfa and grasses) and the outputs were introduced into a digital elevation model. We noted changes in precocity which allowed the sowing of silage maize varieties with longer crop cycles at lower altitudes and an enlargement of the crop zone above 700-800 m. When introducing monthly temperature variations, we observed major frost damage which decreased maize yields. As for gramineous and alfalfa grasslands, we obtained a lengthening in the growing period with earlier first cut dates and sometimes the possibility of a supplementary cut.

Fatigue-Transfer Functions: How Do They Compare?

The primary objective of this work was to investigate which of several fatigue-transfer functions predict the failure of mixtures and expected fatigue life most accurately. A second objective was to study existing fatigue models and how they relate to mixture volumetrics. This work was done by employing layered elastic analysis to obtain stresses and strains in the pavement under monthly temperature variations. The calculated tensile strains were then used in the fatigue-transfer functions to predict the fatigue life of the pavement. The mix and distress data were obtained from the WesTrack project. In general, all fatigue-model predictions were poor to fair; even the locally calibrated models (WesTrack) yielded at best 57% accuracy in predicting failing or surviving mixtures. The Strategic Highway Research Program (SHRP) model predicted failures with 72% accuracy; the Asphalt Institute model, 39%; Medani and Molenaar's model, 31%; and the Shell models, 28% accuracy. The SHRP and Asphalt Institute models used suggested field shift factors (FSFs). The fatigue models studied were originally developed for predicting crack initiation in the laboratory. In using these models to predict fatigue life in actual pavements, crack propagation is usually addressed through an empirically determined FSF. An attempt was made to calibrate and recalibrate the fatigue-transfer models using the WesTrack data. This analysis indicates that there is a trade-off in predicting failing or surviving mixtures correctly and the accuracy of the predicting fatigue life compared with the applied traffic loading. Because the nonfailed mixtures were trafficked with only 5 million traffic repetitions, the error associated with the fatigue-life predictions was unknown. Therefore, the overall improvement of the model accuracy through this calibration process cannot be assessed. For several reasons, this study recommends using the Asphalt Institute fatigue-transfer equation in layered elastic analysis to evaluate the fatigue-cracking potential of asphalt mixtures.

Societies and Academies

LONDON. Royal Society, Feb. 23.—Sir Leonard Rogers: The yearly variations in plague in India in relation to climate: Forecasting epidemics. The seasonal incidence of plague in India depends on monthly variations in mean temperature and humidity, expressed as saturation deficiency, as pointed out by St. John Brooks. Mean monthly temperature variations in hot weather and monsoon periods influence subsequent plague, through high temperatures reducing, and low ones favouring, its prevalence. Saturation deficiency in cold weather as well as in the hot season influences plague incidence, through high saturation deficiency, indicating low relative humidity, reducing prevalence of plague, and vice versa. The great yearly variations in plague can nearly all be explained by the influence of these climatic factors. In the three northern areas, Punjab, United Provinces, and Bihar, four of the six climatic factors become evident before the annual increase of plague from December onwards, and thus allow the more important yearly increases and decreases to be forecast, as a rule. This is also the case to a large extent in Central Provinces. In Deccan, with early increase of plague during monsoon months, forecasts are of less value.