Dry Heat Research Articles

Effect of dry heat and heat moisture treatments on physicochemical and functional properties of finger millet flour and effect of their substitution on characteristics of prepared bread

Effect of dry heat and heat moisture treatments on physicochemical and functional properties of finger millet flour and effect of their substitution on characteristics of prepared bread

Parameter optimization of hot dry rock heat extraction based on discrete element crack network model

Hot-dry-rock (HDR) has long been considered a potential exploitable energy source due to its high energy content, cleanliness, and abundant reserves. However, HDR typically resides in ultra-deep strata with high temperatures and pressures, which makes its extraction a highly complex thermal-hydrological-mechanical (THM) coupling. In this paper, the THM coupling relationship in the geothermal extraction is clarified. It establishes a dynamic porosity and permeability model and creates a pair-well geothermal extraction model. The investigation focuses on understanding the influence of the pressure difference between pair-wells, number of cracks, and injection temperature on the heat extraction temperature, permeability ratio, geothermal reservoir reduction rate, and heat extraction temperature. The research findings indicate the following: (1) Increasing the inter-well pressure difference from 2 to 10 MPa reduces the extraction temperature from 155 to 138 °C. However, the thermal reservoir permeability ratio increases from 1.07 to 1.35. Consequently, the extraction efficiency rises from 6.2 to 12.4 MW. (2) The number of cracks from 200 to 400 led to a decrease in extraction temperature from 160 to 115 °C. However, the thermal reservoir permeability ratio increases from 1.12 to 1.35. In the first 8 years of extraction, the thermal pumping power of 400 cracks exceeded 200 cracks, but later this trend reversed. (3) Elevating the injection temperature from 20 to 60 °C increases the extraction temperature from 142 to 158 °C while reducing the permeability ratio from 1.28 to 1.20. Consequently, the extraction power decreases from 8 to 6 MW. (4) The inter-well pressure difference has the greatest impact on the decrease in extraction temperature, whereas the number of cracks has the greatest impact on the increase in permeability ratio. Injection temperature has the most significant impact on extraction power. This study reveals that increasing the pressure difference between wells, increasing the number of cracks, and lowering the injection fluid temperature will enhance geothermal extraction power. These findings provide valuable insights for geothermal development.

Reconstruction of the historic time course of blood-borne virus contamination of clotting factor concentrates, 1974-1992.

Factor VIII and IX clotting factor concentrates manufactured from pooled plasma have been identified as potent sources of virus infection in persons with hemophilia (PWHs) in the 1970s and 1980s. To investigate the range and diversity of viruses over this period, we analysed 24 clotting factor concentrates for several blood-borne viruses. Nucleic acid was extracted from 14 commercially produced clotting factors and 10 from nonremunerated donors, preserved in lyophilized form (expiry dates: 1974-1992). Clotting factors were tested by commercial and in-house quantitative PCRs for blood-borne viruses hepatitis A, B, C and E viruses (HAV, HBV, HCV, HEV), HIV- types 1/2, parvoviruses B19V and PARV4, and human pegiviruses types 1 and 2 (HPgV-1,-2). HCV and HPgV-1 were the most frequently detected viruses (both 14/24 tested) primarily in commercial clotting factors, with frequently extremely high viral loads in the late 1970s-1985 and a diverse range of HCV genotypes. Detection frequencies sharply declined following introduction of virus inactivation. HIV-1, HBV, and HAV were less frequently detected (3/24, 1/24, and 1/24 respectively); none were positive for HEV. Contrastingly, B19V and PARV4 were detected throughout the study period, even after introduction of dry heat treatment, consistent with ongoing documented transmission to PWHs into the early 1990s. While hemophilia treatment is now largely based on recombinant factor VIII/IX in the UK and elsewhere, the comprehensive screen of historical plasma-derived clotting factors reveals extensive exposure of PWHs to blood-borne viruses throughout 1970s-early 1990s, and the epidemiological and manufacturing parameters that influenced clotting factor contamination.

Comparing the impact of various sterilization methods on the cyclic fatigue resistance, bending strength, and torsional fatigue properties of NiTi rotary files

This study aimed to evaluate the influence of various sterilization techniques on the cyclic fatigue resistance, bending strength, and torsional fatigue resistance of Tornado Blue and Race Evo rotary endodontic file systems. Both the file systems underwent a series of 15 cycles of sterilization according to the following study groups: control group (G1; i.e., without treatment), chemical sterilization with 5.25% sodium hypochlorite (G2), dry heat sterilization (G3), glass beads sterilization (G4), and steam autoclaving (G5). Each group consisted of 8 samples (n = 8/group). Statistical analysis was performed using a two-way ANOVA and Tukey’s tests (p ≤ 0.05). Mean values for the number of cycles between both files were 1291 ± 52.79 rpm and 2095 ± 52.91 rpm for Tornado Blue and Race Evo, respectively. The torsional fatigue resistance was 8.00 ± 0.85 NCF and 10.70 ± 0.85 NCF and the bending strength was 486.94 ± 20.97 gf and 564.17 ± 20.97 gf for Tornado Blue and Race Evo, respectively. The results showed no significant difference in the mechanical properties followed by different sterilization protocols. However, a significant difference was observed in tested properties between the two file systems (p ≤ 0.05). The outcome is reassuring for clinicians that the essential process of routine sterilization at clinics seems safe with regards to mechanical integrity of the endodontic files.

Measurement of microclimates in a warming world: problems and solutions.

As the world warms, it will be tempting to relate the biological responses of terrestrial animals to air temperature. But air temperature typically plays a lesser role in the heat exchange of those animals than does radiant heat. Under radiant load, animals can gain heat even when body surface temperature exceeds air temperature. However, animals can buffer the impacts of radiant heat exposure: burrows and other refuges may block solar radiant heat fully, but trees and agricultural shelters provide only partial relief. For animals that can do so effectively, evaporative cooling will be used to dissipate body heat. Evaporative cooling is dependent directly on the water vapour pressure difference between the body surface and immediate surroundings, but only indirectly on relative humidity. High relative humidity at high air temperature implies a high water vapour pressure, but evaporation into air with 100% relative humidity is not impossible. Evaporation is enhanced by wind, but the wind speed reported by meteorological services is not that experienced by animals; instead, the wind, air temperature, humidity and radiation experienced is that of the animal's microclimate. In this Commentary, we discuss how microclimate should be quantified to ensure accurate assessment of an animal's thermal environment. We propose that the microclimate metric of dry heat load to which the biological responses of animals should be related is black-globe temperature measured on or near the animal, and not air temperature. Finally, when analysing those responses, the metric of humidity should be water vapour pressure, not relative humidity.

Melospiza melodia (Song Sparrow) bill size is primarily shaped by thermoregulation on the California Channel Islands

ABSTRACT Inferring the environmental selection pressures responsible for phenotypic variation is a challenge in adaptation studies as traits often have multiple functions and are shaped by complex selection regimes. We provide indirect evidence that morphology of the multifunctional avian bill is primarily shaped by climate and thermoregulatory ability in Melospiza melodia (Song Sparrow) on the California Channel Islands. Our research builds on a study in M. melodia museum specimens that demonstrated a positive correlation between bill surface area and maximum temperature, suggesting a greater demand for dry heat dissipation in hotter, xeric environments. We sampled contemporary sparrow populations across 3 climatically distinct islands to test the hypotheses that bill morphology is influenced by habitat differences with functional consequences for foraging efficiency and is related to maximum temperature and, consequently, important for thermoregulation. Measurements of >500 live individuals indicated a significant, positive relationship between maximum temperature and bill surface area when correcting for body size. In contrast, maximum bite force, seed extraction time, and vegetation on breeding territories (a proxy for food resources) were not significantly associated with bill dimensions. While we cannot exclude the influence of foraging ability and diet on bill morphology, our results are consistent with the hypothesis that variation in M. melodia need for thermoregulatory capacity across the northern Channel Islands selects for divergence in bill surface area.

Development and validation of stability indicating HPTLC method for simultaneous estimation of Dapagliflozin and Linagliptin

For the treatment of Type 2 Diabetes Mellitus, Dapagliflozin selectively inhibits the sodium-glucose co-transporter-2, while Linagliptin competitively and reversibly inhibits dipeptidyl peptidase-4 in a fixed dose combination (1:1). Dapagliflozin and Linagliptin estimation in bulk and tablet formulation was accomplished by the development and validation of a precise and accurate HPTLC method. The procedure used Toluene: Chloroform: Methanol: Triethylamine (7:2:1:0.2 v/v/v) as the mobile phase and HPTLC aluminum plates pre-coated with silica gel 60 F254 as the stationary phase used. Dapagliflozin and Linagliptin were determined to have Rf values of 0.23 and 0.40 correspondingly. At 224 nm, densitometric analysis was performed in the absorbance mode. For Dapagliflozin and Linagliptin 200–1200 ng/band were the linear ranges in which the procedure produced results. Forced degradation studies were performed on both Dapagliflozin and Linagliptin active pharmaceutical ingredients like acid hydrolysis, base hydrolysis, chemical oxidation, dry heat and photodegradation studies. Dapagliflozin and Linagliptin are susceptible to acid hydrolysis, base hydrolysis, chemical oxidation while both the chemical substances are stable to dry heat and photolytic studies.

Challenges Faced by Parents of Pediatric Burn Survivors: A Thematic Analysis

Background: Burn injuries compromise the integrity of skin, its appendages, and underlying tissues due to exposure to various agents including dry and moist heat, corrosive substances, and high voltage electric currents. Particularly in the pediatric population, these injuries not only affect the children but also significantly impact the lives and health of their parents. Objective: This study aimed to explore the multifaceted challenges faced by parents of pediatric burn survivors at the Burn and Plastic Surgery Center in Hayatabad KPK Peshawar. Methods: Employing a qualitative case study design, this research involved 10 participants selected via purposive sampling. Data collection was conducted through face-to-face in-depth interviews using a semi-structured interview guide. All interviews were audio-recorded, with non-verbal cues and expressions meticulously documented. Thematic analysis was utilized to derive codes, categories, and subsequently, themes from the data. Results: Analysis revealed five major themes reflecting the challenges encountered by parents: socio-economic difficulties, psychological distress, physiological and physical health issues, spiritual anxiety with altered religious activities, and domestic violence and abuse. Specifically, 70% of participants experienced significant disruptions in their daily lives and interactions, while 100% reported financial hardships directly affecting their ability to manage the health care needs of their children. Conclusion: The study underscores the extensive challenges that parents of pediatric burn survivors face, highlighting the necessity for healthcare professionals to adopt a holistic approach in treating burnt children while concurrently addressing parental difficulties. Effective identification and management of these challenges are crucial to improving health outcomes for both the children and their parents.

Distribution of Traditional Chinese Medicine syndromes in diabetic kidney disease chronic kidney disease 1-5: a correlation study.

To analyze the distribution of Traditional Chinese medicine (TCM) syndromes in patients with diabetic kidney disease (DKD) and its related factors. We enrolled 435 patients with DKD, who were not undergoing dialysis, admitted to the Department of Nephrology, First Medical Center, Chinese PLA General Hospital from April 2020 to August 2021. Analysis of their TCM syndromes and related factors was carried out. The 435 patients included 109, 117, 86, and 123 chronic kidney disease (CKD) 1-2, CKD3, CKD4, and CKD5 cases, respectively. With the progression of CKD1-5, the proportion of Yin deficiency and dry heat syndrome, and that of Qi and Yin deficiency syndrome showed a downward trend, whereas the proportion of spleen-kidney Yang deficiency, blood deficiency, blood stasis, water stagnation, and phlegm turbidity syndromes showed an upward trend; the differences were statistically significant (P < 0.05). Multivariate logistic regression analysis showed that Yin deficiency and dry heat syndrome was positively correlated with hemoglobin [odds ratio (OR) = 1.022, P = 0.005], albumin (OR = 1.058, P = 0.006), and estimated glomerular filtration rate (eGFR) (OR = 1.020, P < 0.001) but negatively correlated with male sex (OR = 0.277, P = 0.004). Qi and Yin deficiency syndrome was positively correlated with albumin (OR = 1.056, P < 0.001) and eGFR (OR = 1.008, P = 0.022) but negatively correlated with age (OR = 0.977, P = 0.023). Liver-kidney Yin deficiency syndrome was positively correlated with age (OR = 1.028, P = 0.021) and glycosylated hemoglobin (OR = 1.223, P = 0.007) but negatively correlated with total cholesterol (OR = 0.792, P = 0.006). Spleen-kidney Yang deficiency syndrome was negatively correlated with hemoglobin (OR = 0.977, P < 0.001), albumin (OR = 0.891, P < 0.001), and eGFR (OR = 0.978, P < 0.001) but positively correlated with high density lipoprotein (OR = 3.376, P = 0.001). With CKD1-5 progression, TCM syndromes changed from Yin deficiency and dry heat syndrome to syndrome of deficiency of both Qi and Yin, liver-kidney Yin, and spleen-kidney Yang deficiency syndromes. TCM syndromes were correlated with laboratory test results.

Effects of repeated and continuous dry heat treatments on the physicochemical, structural, and in vitro digestion properties of chickpea starch

The study investigated the impacts of repeated (RDH) and continuous dry heat (CDH) treatments on the physicochemical, structural, and in vitro digestion properties of chickpea starch. The results of SEM and CLSM showed that more fissures and holes appeared on the surface of granules as the treated time of CDH and the circles of RDH increased, both of which made the starch sample much easier to break down by digestive enzymes. Moreover, the fissures and holes of starch granules treated by CDH were more obvious than those of RDH. The XRD and FT-IR results suggested that the crystal type remained C-type, and the relative crystallinity and R1047/1022 of the chickpea starch decreased after dry heat treatments. In addition, a marked decline in the pasting viscosity and gelatinization temperature of chickpea starches was found with dry heat treatments. Moreover, the increased enzyme accessibility of starch was fitted as suggested by the increased RDS content and digestion rate. This study provided basic data for the rational design of chickpea starch-based foods with nutritional functions.

The Potency of Maillard Conjugates Containing Whey Protein as Natural Emulsifier.

There is a continued need for the advancement of natural emulsifiers to replace synthetic emulsifiers, driven by human health concerns. This study is aimed at producing protein-polysaccharide conjugates through the Maillard reaction and at evaluating its ability as an emulsifier based on its emulsifying properties. The proteins used in this study were bovine milk whey protein and soy protein isolates, while the polysaccharides were maltodextrin and pectin. The protein-polysaccharide conjugation used a Maillard reaction under dry heating conditions. The protein and polysaccharide mass ratios were 1 : 2 and 1 : 3. The results showed that the types of proteins and polysaccharides and their mass affect the surface tension of the conjugate products. Whey protein-pectin conjugates with a mass ratio of 1 : 2 and a concentration of 1% had the lowest surface tension at 43.77 dyne/cm2. This conjugate sample also showed the highest emulsifying index at 27.20 m2/g. The conjugate powder containing pectin as a polysaccharide showed better emulsifying activity than that of those containing maltodextrin. However, the smallest droplet size of the emulsion (256.5 nm) resulted from the emulsification process using whey protein-maltodextrin conjugates as an emulsifier. The FTIR and gel electrophoresis (SDS-PAGE) analysis confirmed the conjugation formation. In general, protein-polysaccharide conjugates containing whey protein could potentially act as a natural emulsifier for food.

Stability indicating for Quality Control Assessment of three antidiabetic molecules using HPLC technique: Stability Assessment of three antidiabetic molecules

Diabetes mellitus responds better to co-formulated tablet dosages of dapagliflozin (DFZN), metformin (MFMN), and vildagliptin (VDGN). For the purpose of studying stability and quantifying DFZN, VDGN, and MFMN in bulk forms and in dosage forms, an efficient and fast HPLC method of analysis is currently developed. The mobile phase featured 80:20 (v/v) 0.2 M, pH 3.0, ammonium acetate buffer and acetonitrile mixed together and Luna's HPLC C-18 column, named Phenyl hexyl, was utilised for DFZN, VDGN, and MFMN separation and its quantification. The PDA type detector operating at 235 nm wavelength was deployed. The “International Conference on Harmonisation” recommendations were strictly adhered throughout the validation process. A strong linear association between response and quantity in the range of 2.5–15 µg/ml (DFZN), 25–150 µg/ml (VDGN), and 125–750 µg/ml (MFMN) is supported by the regression information for the DFZN, VDGN, and MFMN calibration plots. The precision, selectivity, accuracy, sensitivity, ruggedness and robustness were satisfactory for the method. The tablet sample of DFZN, VDGN, and MFMN was subjected to acid, water, base, sodium bisulfite, light, dry heat and peroxide degradations. Significant differences in retention times were observed between the well-resolved peaks of the degradants and the primary peaks (DFZN, VDGN, and MFMN). Thus, the assay might be characterised as stability indicating. The contents of DFZN, VDGN, and MFMN in dosage forms were assessed precisely and accurately by currently developed HPLC technique. This technique may be applied to ensure the quality of formulation doses for DFZN, VDGN, and MFMN contents.

The effects of dry heat and steam on germination of dry and imbibed seeds of the invasive garden lupine (Lupinus polyphyllus Lindl.)

Abstract Regularly mown road verges are an important habitat for conservation of grassland vegetation. Disturbance and movement of seed-contaminated soil during road construction and maintenance makes road verges susceptible to the establishment of invasive alien plants such as garden lupine (Lupinus polyphyllus Lindl.). To combat spread of L. polyphyllus via seeds, we tested methods for seed destruction using heat. This study aimed at developing heat eradication methods for dry and imbibed L. polyphyllus seeds applying dry heat (88, 93, 98, 103 C at 1, 3, 5, 10 min) in a laboratory, steam (85, 90, 95 C at 3, 5, 10 min) in a test-box steaming device and (97 C at 10-17 min; dry seeds only) in a stationary soil-steaming machine (S30). In order to speed up water absorption and post-treatment germination, the imbibed seeds were manually scarified before the heat treatment and the dry seeds afterwards. Additionally, germination of two different age seed batches was tested applying dry heat (88, 98 C at 3, 5 min). The results showed that steam treatments inhibited seed germination more than dry heat in both dry and imbibed seeds. Germination dropped to &lt; 5% when steamed at ≥ 90 C or dry-heated at &gt; 100 C. Seed germination decreased with higher temperatures and longer exposure times. Imbibed seeds exhibited lower germination compared to dry seeds for dry and steam heat. Approximately 0.5% of dry seeds germinated when steamed using S30. 2022-collected seeds were less sensitive to dry heat than seeds from 2020. In conclusion, hot steam is more effective in reducing L. polyphyllus seed germination than dry heat. Thus, to successfully eradicate L. polyphyllus seeds in soil masses, we recommend steaming them at 97 C for at least 10 minutes.

Mesonet-Based Climatology Of Severe Convective Winds in West Texas

Multiple studies have investigated the occurrence of severe convective winds and have increased our understanding of the forces driving severe winds and their spatial and temporal patterns. Some of the data used in studies have come from airport stations maintained by the National Weather Service. Their standardization across the United States makes them ideal for research, but they are limited in their distribution. This study aims to create a climatology of severe convective winds in West Texas using a mesoscale network (“mesonet”). Like their ASOS (Automated Surface Observing System) counterparts, these stations are standardized and well maintained. This study provides a 15-year climatology of severe convective wind gusts measured by the West Texas Mesonet (WTM). After extracting and manually verifying the measured gusts from over 30 WTM stations, both spatial and temporal distributions are presented. While temporal patterns in the gust distribution generally matched previous research, the high spatial resolution of the mesonet elucidated differences across a regional escarpment known as the Caprock. Comparison with regional AWOS / ASOS stations also revealed potential effects of a larger urban area. In addition to gust data, thermodynamic characteristics and rainfall accumulations associated with each gust were also investigated. In doing so, a substantial contribution from dry thunderstorm outflow winds and heat bursts to the production of regional severe wind was documented.

Effects of dry-heat treatment on amylose content, hydration, structural and pasting properties of Kodo flour for application in breakfast cereal

Effects of dry-heat treatment on amylose content, hydration, structural and pasting properties of Kodo flour for application in breakfast cereal

Recent advances, challenges and functional applications of protein glycosylation modification in food industry

SummaryProtein glycosylation modification is an effective way to enhance the functional properties of natural proteins. This study aims to explore the preparation of glycosylation products (PPCs) through the Maillard reaction or enzymatic glycosylation using transglutaminase. The study discusses the advantages and disadvantages of preparing PPCs using dry heat, wet heat, and enzymatic glycosylation, as well as factors influencing the glycosylation process. Compared to natural proteins, PPCs demonstrate superior functional properties, including solubility, viscosity, emulsifying ability, gelling ability, thermal stability, antioxidant activity, and antibacterial activity. With improved functional performance, PPCs have broad application prospects as raw materials in food processing. For example, PPCs can be used as antioxidants, emulsifiers, gelling agents, and carriers for various bioactive molecules in the food industry. In the pharmaceutical field, PPCs are expected to serve as contrast agents and dressings. Furthermore, the application of PPCs in food processing should also consider specific processing requirements to achieve the intended enhancement of glycosylated protein functionality.

Assessment of performance and sustainability of waste heat dryer coupled with air conditioner unit during drying of banana slices

The present work presents the effective application of waste heat rejected from window air conditioning (AC) in a waste heat dryer (WHD) for drying plantain banana slices. The comparison between drying with the waste heat dryer coupled with an AC unit (ACWHD) and a natural convective indirect solar dryer (SD) reveals significant differences in drying kinetics, supply air conditions, and thermodynamic performance. The drying kinetics of banana slices obtained with ACWHD and SD were validated by revisiting the concepts of dryer performance index (DPI) and generalized drying curve. The temperature of the hot air supplied to the drying chamber in ACWHD was 48 °C while the relative humidity of the supply air was below 30 %. The thermodynamic performance assessment revealed that the exergetic efficiency was about 45 % and 16 % for ACWHD and SD respectively. The results of exergy based sustainable index and environment impact factor indicated the potential application of the waste heat of residual air from AC units for drying applications. Thus, the results of the present study imply that this novel idea has appreciable potential for commercialization with large-scale central air conditioning units in commercial complexes and industries where the magnitude of heat rejection will be multi-fold.

Role of Resistant Starch in Food and Healthcare Industry: A Review

Starches are complex polysaccharides which are notorious to create glucose load in diet. But the advancements in the fields of food chemistry have come up with a fact that there are some starches which can release glucose in controlled manner. They are known as resistant starches. They are basically four types depending upon sources of origin: Type I physical inaccessible starch (RS1), Type II that inhibit the action of enzymes (RS2), Type III retrograded starch (RS3) and Type IV chemically modified starch (RS4). Resistant Starches now a days are used in many sectors of food industry. It has unique physical and chemical properties such as high viscosity, formation of gel and water-binding capacity that make it valuable new food product development. This has enhanced its usage in food industries. The bland flavour and transparency in colour of RS with low water holding property is making them a good encapsulating medium in microencapsulation of probiotics. They are known to have low glycemic index and good impact on bowel health by acting as prebiotic to the gut microflora. Their demand in the food industry is arisen to the extent that normal starches are retrograded to convert them to RS. Impact of dry and wet heat methods of cooking on content of resistant starches in several food products have been established by many studies.

Skin Wetting Attenuates the Thermal Strain of Older Adults Exposed to Very Hot and Dry Heat with Accompanying Activities of Daily Living

Heat waves cause more deaths and hospitalizations in the elderly relative to any other age group. Indoor cooling with an air conditioner is an effective strategy to prevent the deleterious health effects of heat. However, air conditioning may not be available to some due to limited access, rising energy costs, power outages, and/or industry/government-imposed rolling blackouts. Thus, there is a clear need to identify non-air conditioning dependent cooling strategies to attenuate excessive elevations in body temperature and associated physiological strain in the elderly during heat wave conditions. Purpose: We tested the hypothesis that supplemental skin wetting via water spray attenuates elevations in core temperature and the accompanying physiological strain in older adults exposed to very hot and dry heat with accompanying activities of daily living. Methods: In a randomized order, 10 older adults (4 Females/6 Males; 74 ± 5 years) were exposed to 3-hours of ambient heating, replicating peak environmental conditions during the 2018 Los Angeles heat wave (47 ºC, 15% relative humidity), with (water spray) or without (control) skin-wetting via tap temperature water (~40 g applied every 10-minutes). To simulate heat generation associated with activities of daily living, participants performed six 5-minute periods of light exercise (~3 METS; metabolic heat production: 2.93 ± 0.42 W/kg in control and 2.95 ± 0.44 W/kg in water spray) dispersed throughout the heat exposure. To maintain euhydration, participants consumed 3 mL/kg/hr of tap-temperature water. We assessed core and skin temperatures, heart rate, whole-body sweat rate, and forearm blood flow (as a surrogate of changes in skin blood flow). We compared data between control and water spray trials using one-tailed paired t-tests. Results: When compared to control, water spray reduced the increase in core temperature by 0.33 ± 0.43 °C (p=0.020), ending skin temperature by 1.83 ± 0.73 °C (p&lt;0.001), and ending heart rate by 6 ± 9 bpm (p=0.033). Whole-body sweat rate was 2.12 ± 1.08 g/min lower with water spray compared to control (p&lt;0.001). However, the increase in forearm blood flow was not different between control (154 ± 74 mL/min) and water spray (149 ± 93 mL/min) trials (p=0.400). Conclusion: These preliminary data show that supplemental skin-wetting via water spray attenuates the thermal (core and skin temperature) and associated physiological strain (heart rate and fluid-loss) of older adults exposed to extreme heat with accompanying activities of daily living. The downstream impact of this reduced thermal strain on cardiac and renal stress should be examined, as these are two of the main causes of heat-related morbidity and mortality. Supported by NIH R01AG069005 (CGC) and AHA 23POST1023065 (ZJM). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Re‐examining the effect of heat and water stress on agricultural output growth: How is Sub‐Saharan Africa different?

AbstractWe examine the impact of climate driven heat and water stress on aggregate crop production growth, paying particular attention to the Sub‐Saharan Africa (SSA) region as opposed to studies with a global or Non SSA focus. Using gridded data on temperature and precipitation, which is crop weighted and averaged to the national level, we generate measures of stressors that capture average temperature and precipitation shocks, and extreme punctuated events like dry spells and heat waves for 38 countries in Sub Saharan Africa between 1979 and 2016. We find in general that compared to estimates with a global or non SSA focus, the detrimental effect of increased annual temperature has been overstated, while the damage caused by shorter‐term extremes like dry spells and heat waves has been understated. This implies that region specific analysis is key in developing a more comprehensive understanding of climate change. Such analyses are pivotal for climate policy development allowing for more spatially efficient allocation of limited financial resources, and greater accuracy in estimating adaptation effects.