Combined Effects Of Cold Research Articles

Combined effects of cold and acid on dual-species biofilms of Pseudomonas fluorescens and Listeria monocytogenes under simulated chilled beef processing conditions

Interactions across bacterial species boundaries are usually influenced by environmental stresses, yet little has been evaluated regarding multifactorial stresses on the fate of dual-species biofilm formation in food industry. In this study, the processing conditions of chilled beef were established as a combination of cold and acid stresses (4 °C and pH 5.4), with pH 7.0 or 25 °C serving as the controls, to investigate the interaction of dual-species biofilm between Pseudomonas fluorescens and Listeria monocytogenes. Dual-species biofilms significantly increased biofilm formation at 72 h under the condition of 25°C-pH7.0 and 25°C-pH5.4 (P < 0.05). Compared with mono-species biofilms, the cell numbers of L. monocytogenes in dual-species biofilms were lower at 25 °C (P < 0.05), however, the adherent cells of L. monocytogenes was higher in dual-species biofilms at 4 °C (P < 0.05). Furthermore, the amount of extracellular polysaccharides and proteins secreted by single P. fluorescens biofilms at 4 °C was more than three times than those at 25 °C. The surface-enhanced Raman spectroscopy further profiled the variability of extracellular polymeric substances (EPS) composition. Additionally, RT-qPCR results revealed an upregulation of biofilm-related and genes in co-culture species. It provides valuable insights into the strategies for removing mixed biofilms under diverse stressful conditions in practical food processing.

Combined effect of cold with heart pathology in old

Death due to hypothermia is because of exposure to cold temperature, usually during winter season and at high altitudes. Hypothermia occurs when the core body temperature drops below 35°C. Diagnosing hypothermia as the cause of death is very challenging in forensic medicine as the post-mortem findings are not consistent for all hypothermia cases. Therefore, history of the case and investigation of circumstances of the death, crime scene along with a meticulous post-mortem examination is very important in diagnosing cause of death as due to hypothermia. Paradoxical undressing and hide and die syndrome can sometime make the crime scene very suspicious. Hypothermia mainly affects homeless individuals, drug-dependent individuals and those of extreme ends of the age spectrum but can occur in any age group. Hypothermia is relatively rare in places like India with temperate climates as compared to places with colder climate. Hence, there is lack of knowledge about such a condition among both the medical professionals and the common people. Here we report a case of hypothermia in an 82 year old male who was found dead, half naked during the cold winter season and when stomach was opened, Wischnewsky spots were observed on the mucosa.

Temperature and Light-Quality-Dependent Regulation of Freezing Tolerance in Barley.

It is established that, besides the cold, incident light also has a crucial role in the cold acclimation process. To elucidate the interaction between these two external hardening factors, barley plantlets were grown under different light conditions with low, normal, and high light intensities at 5 and 15 °C. The expression of the HvCBF14 gene and two well-characterized members of the C-repeat binding factor (CBF)-regulon HvCOR14b and HvDHN5 were studied. In general, the expression level of the studied genes was several fold higher at 5 °C than that at 15 °C independently of the applied light intensity or the spectra. The complementary far-red (FR) illumination induced the expression of HvCBF14 and also its target gene HvCOR14b at both temperatures. However, this supplementation did not affect significantly the expression of HvDHN5. To test the physiological effects of these changes in environmental conditions, freezing tests were also performed. In all the cases, we found that the reduced R:FR ratio increased the frost tolerance of barley at every incident light intensity. These results show that the combined effects of cold, light intensity, and the modification of the R:FR light ratio can greatly influence the gene expression pattern of the plants, which can result in increased plant frost tolerance.

Cardiovascular responses to cold and submaximal exercise in patients with coronary artery disease.

Regular year-round exercise is recommended for patients with coronary artery disease (CAD). However, the combined effects of cold and moderate sustained exercise, both known to increase cardiac workload, on cardiovascular responses are not known. We tested the hypothesis that cardiac workload is increased, and evidence of ischemia would be observed during exercise in the cold in patients with CAD. Sixteen men (59.3 ± 7.0 yr, means ± SD) with stable CAD each underwent 4, 30 min exposures in a randomized order: seated rest and moderate-intensity exercise [walking, 60%-70% of max heart rate (HR)] performed at +22°C and -15°C. Systolic brachial blood pressure (SBP), HR, electrocardiogram (ECG), and skin temperatures were recorded throughout the intervention. Rate pressure product (RPP) and ECG parameters were obtained. The combined effects of cold and submaximal exercise were additive for SBP and RPP and synergistic for HR when compared with rest in a neutral environment. RPP (mmHg·beats/min) was 17% higher during exercise in the cold (18,080 ± 3540) compared with neutral (15,490 ± 2,940) conditions ( P = 0.001). Only a few ST depressions were detected during exercise but without an effect of ambient temperature. The corrected QT interval increased while exercising in the cold compared with neutral temperature ( P = 0.023). Recovery of postexercise blood pressure was similar regardless of temperature. Whole body exposure to cold during submaximal exercise results in higher cardiac workload compared with a neutral environment. Despite the higher RPP, no signs of myocardial ischemia or abnormal ECG responses were observed. The results of this study are useful for planning year-round exercise-based rehabilitation programs for stable CAD patients.

Influence of Glacier Melting and River Discharges on the Nutrient Distribution and DIC Recycling in the Southern Chilean Patagonia

AbstractThe Chilean Patagonia constitutes one of the most important and extensive fjord systems worldwide, therefore can be used as a natural laboratory to elucidate the pathway of both organic and inorganic matter in the receiving environment. In this study we use data collected during an intensive oceanographic cruise along the Magellan Strait into the Almirantazgo Fjord in southern Patagonia to evaluate how different sources of dissolved inorganic carbon (DIC) and recycling may impact particulate organic carbon (POC) δ13C and influence the nutrients and carbonate system spatial distribution. The carbonate system presented large spatial heterogeneity. The lowest total alkalinity and DIC were associated to freshwater dilution observed near melting glaciers. The δ13CDIC analysis suggests that most DIC in the upper 50 m depth was not derived from terrestrial organic matter remineralization. 13C‐depleted riverine and ice‐melting DIC influence the DIC pool along the study area, but due to that DIC concentration from rivers and glaciers is relatively low, atmospheric carbon contribution or biological processes seem to be more relevant. Intense undersaturation of CO2 was observed in high chlorophyll waters. Respired DIC coming from the bottom waters seems to be almost insignificant for the inorganic carbon pool and therefore do not impact significantly the stable carbon isotopic composition of dissolved organic carbon and POC in the upper 50 m depth. Considering the combined effect of cold and low alkalinity waters due to ice melting, our results highlight the importance of these processes in determining corrosive waters for CaCO3 and local acidification processes associated to calving glacier in fjord ecosystems.

The Combined Effect of Cold and Moisture on Manual Performance.

The combined effect of cold and moisture led to the largest performance decrements except when intrinsic object properties helped with grasp maintenance. The independent effects of cold and moisture on manual performance were comparable. Application Tools and equipment for use in the cold ocean environment should be designed to minimize the effects of cold and moisture on manual performance by including object properties that enhance grasp maintenance and minimize the fine-dexterity requirements.

GW25-e0842 Alteration in right heart function upon high-altitude exposure and its roles in Acute mountain sickness

People who rapidly ascend to the high altitude above 3 000 m or a higher altitude than residence without adaptation will not acclimatize to high altitude in the combined effect of cold, physical overloading labour and hypobaric hypoxia that reduce tolerance hypoxia environment. Most of maladaptive

The combined effect of cold and light intensity stress on some morphological and physiological parameters in two soybean (Glycine max L.) cultivars

In order to evaluate the response of two soybean cultivars (032 and BP) to cold stress [control (28°C) and cold stress (5°C)] at two light intensity levels [normal light (8000 lux) or low light (2000 lux) intensity], an experiment was done in a factorial arrangement based on completely randomized design with three replicates under greenhouse conditions. The results clearly showed that leaf number and chlorophyll a and ab contents in soybean seedlings have a tendency to decrease (31, 17 and 14 %, respectively) by cold stress while stem diameter markedly increased (up to 15) as compared to those grown under control conditions. Cold stress reduced nodes number, plant height and chlorophyll content (SPAD value) in two light intensities, however, this effect is more noticeable at low light intensity for nod numbers (31%) and plant height (56%) and at high light intensity for SPAD value (21%). Cold stress also significantly suppressed plant height in both cultivars (52% in 032 and 47% in BP). Where light intensity increased from 2000 to 8000 lux, 032 plants exhibited slightly increase in stem diameter and chlorophyll b while BP plants exhibited 9 and 21% decrease , respectively. In conclusion, cold stress in either 2000 or 8000 lux could adversely affect morphological parameters of soybean plants, however, the rate of damage increased at low light intensity.

Effects of temperature and photoperiod on glucose, glycerol and glycogen concentrations in &lt;i&gt;Helix pomatia&lt;/i&gt; Linnaeus, 1758 in spring and autumn

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Hydration effects on cognitive performance during military tasks in temperate and cold environments

Body water deficits or hypohydration (HYP) may degrade cognitive performance during heat exposure and perhaps temperate conditions. Cold exposure often induces HYP, but the combined effects of cold and HYP on cognitive performance are unknown. This study investigated whether HYP degrades cognitive performance during cold exposure and if physical exercise could mitigate any cold-induced performance decline. On four occasions, eight volunteers completed one hour of militarily-relevant cognitive testing: 30 min of simulated sentry duty/marksmanship, 20 min of a visual vigilance task, a self-report workload assessment, and a mood questionnaire. Testing was conducted in a cold (2 °C) or temperate (20 °C) environment before and after cycle ergometer (60 min at 60% of VO 2peak) exercise. Each trial was preceded by 3 h of passive heat stress (45 °C) in the early morning with (euhydration, EUH) or without (hypohydration, HYP; 3% body mass) fluid replacement followed by prolonged recovery. HYP did not alter any cognitive, psychomotor, or self-report parameter in either environment before or after exercise. Cold exposure increased ( p < 0.05) target detection latency in the sentry duty task, adversely affected mood and workload ratings, but had no impact on any other cognitive or psychomotor measure. After completing the exercise bout, there were modest improvements in friend–foe discrimination and total response latency in the sentry duty task, but not on any other performance measures. Moderate HYP had no effect on cognitive and psychomotor performance in either environment, cold exposure produced equivocal effects, and aerobic exercise improved some aspects of military task performance.

Adrenergic responses to cognitive activity in a cold environment

Adrenergic responses during physical stress such as cold exposure have been reported to differ from those responses observed during cognitive activity. Both the separate and the combined effects of cold and cognitive activity on catecholamine activity were examined in six male subjects. Alterations in plasma epinephrine and norepinephrine showed different patterns as a function of exposure to a 4 degrees C cold environment, a cognitive performance assessment battery (PAB), and the two conditions combined. Plasma epinephrine was not altered by exposure to cold and only slightly increased by PAB performance when given at 23 degrees C. However, epinephrine was substantially elevated by exposure to combined cold and PAB. Heart rate changes paralleled observed changes in epinephrine. Norepinephrine release was predominantly increased by cold exposure and was not altered by PAB performance.

Combined effect of cold H+ and He+ ions on the proton cyclotron electromagnetic instability

Observations aboard GEOS 1 and 2 show a correlation between generation of strong ion‐cyclotron ULF waves below the proton gyrofrequency and an increase in the cold He+ ion concentration. The amplification process due to one cold species seems to be well understood and has been thoroughly discussed. Nevertheless, the amplification process when two cold species are present has not been so far properly studied. The GEOS experiments have also shown a close association between the occurrence of ion‐cyclotron ULF waves and the presence of thermal He+ ions in the equatorial region of the magnetosphere (Young et al., 1979). Thus we study here the combined effect of cold H+ and He+ ions on the proton cyclotron electromagnetic instability.

COMBINED EFFECT OF COLD AND ALCOHOL ON HEAT BALANCE IN MAN.

The combined effect of alcohol and cold on the heat balance of human subjects was studied by measuring heat production, deep body temperature, and skin surface temperature during an 8-hr night. Moderate doses of alcohol had no deteriorative effect on heat balance during prolonged mild cold exposure. The only noticeable effect of alcohol under these conditions is a hypnotic effect giving the subjects more comfort and sleep. If the cold stress becomes severe, some risk is involved by consuming alcohol, as an insufficient metabolic compensation was observed in one subject resulting in a greater drop of the rectal temperature than when the same subject rested nonintoxicated under the same environmental conditions. cold and alcohol Submitted on January 14, 1963