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Author(s):  
YENNI PUSPITA TANJUNG ◽  
ANDI IKA JULIANTI ◽  
IRNI ISNAYANTI ◽  
AGUSTIN R.

Objective: The aim of this study was to obtain a peel off gel facial mask preparation from Arabica coffee fruit peel extract that meets the requirements and to determine the antioxidant activity of Arabica coffee fruit peel extract and peel off gel facial mask preparation from coffee fruit peel extract Methods: In this study, three formulations of peel off gel facial mask were made with 3 variations in the concentration of coffee fruit peel extract, namely F1 (1%), F2 (2%), and F3 (3%). Furthermore, the preparation was evaluated for 28 d of storage at room temperature (25-30 °C) and cold temperature (8 °C) which included organoleptic, pH, spreading ability, homogeneity, viscosity, dry time, and antioxidant activity. Results: The results of the evaluation showed that F1, F2, and F3 met the requirements which included organoleptic, pH, spreading ability, homogeneity, viscosity, and dry time. The antioxidant activity of the coffee fruit peel extract was very strong (IC50 17.36 µg/ml). The antioxidant activity in the peel off gel facial mask sample of formula F1 (IC50 75.63 µg/ml) and formula F2 (IC50 50.71 µg/ml) was strong, and for formula F3 was very strong (IC50 21.44 µg/ml). Conclusion: All formulas met the evaluation requirements, arabica coffee fruit peel extract and peel of gel facial mask preparation (F3) have very strong antioxidant activity.


2021 ◽  
Author(s):  
Petra Hafker ◽  
Lily M Thompson ◽  
Dylan Parry ◽  
Jonathan A Walter ◽  
Kristine L Grayson

As the global climate changes, high and low temperature extremes can drive changes in species distributions. Across the range of a species, thermal tolerance can experience plasticity and may undergo selection, shaping resilience to temperature stress. In this study, we measured variation in the lower thermal tolerance of early instar larvae of an invasive forest insect, Lymantria dispar dispar L. (Lepidoptera: Erebidae), using populations sourced from the climatically diverse invasion of the Eastern United States. In two chill coma recovery experiments, we recorded recovery time following a period of exposure to a non-lethal cold temperature. A third experiment quantified growth responses after chill coma recovery to evaluate sublethal effects. Our results indicate that cold tolerance is linked to regional climate, with individuals from cold climate populations recovering faster from chill coma. While this geographic gradient is seen in many species, detecting this pattern is notable for an introduced species founded from a single point-source introduction. We demonstrate that the cold temperatures used in our experiments occur in nature from cold snaps after spring hatching, but negative impacts to growth and survival appear low. We expect that population differences in cold temperature performance manifest more from differences in temperature-dependent growth than acute exposure. Evaluating intraspecific variation in cold tolerance increases our understanding of the role of climatic gradients on the physiology of an invasive species, and contributes to tools for predicting further expansion.


Author(s):  
Mateusz Muszyński-Huhajło ◽  
Krzysztof Ratkiewicz ◽  
Kamil Janiak ◽  
Stanisław Miodoński ◽  
Anna Jurga ◽  
...  

Author(s):  
Jingke Du ◽  
Zihao He ◽  
Junqi Cui ◽  
Hanjun Li ◽  
Mingming Xu ◽  
...  

Emerging evidence indicates that bone mass is regulated by systemic energy balance. Temperature variations have profound effects on energy metabolism in animals, which will affect bone remodeling. But the mechanism remains unclear. 2-month-old C57BL/6J male mice were exposed to cold (4°C) and normal (23°C) temperatures for 28 days and the effects of cold exposure on bone mass was investigated. Micro-computed tomography results showed that bone volume fraction was significantly reduced after 14 days of exposure to cold temperature, and it was recovered after 28 days. Ploton silver staining and immunohistochemical results further revealed that exposure to cold decreased canalicular length, number of E11-and MMP13-positive osteocytes after 14 days, but they returned to the baseline levels after 28 days, different from the normal temperature control group. In addition, change of Caspase-3 indicated that exposure to cold temperature augmented apoptosis of osteocytes. In vitro results confirmed the positive effect of brown adipocytes on osteocyte‘s dendrites and E11 expression. In conclusion, our findings indicate that cold exposure can influence bone mass in a time-dependent manner, with bone mass decreasing and recovering at 2 and 4 weeks respectively. The change of bone mass may be caused by the apoptosis osteocytes. Brown adipocyte tissue could influence bone remodeling through affecting osteocyte.


2021 ◽  
Author(s):  
Allan Norico ◽  
Rommel Estores

Abstract Temperature dependent failures are some of the most challenging cases that will be encountered by the analyst. Soft Defect Localization (SDL) is a technique used to analyze such temperature-dependent, ‘soft defect’ failures [1]. There are many literatures that discuss this technique and its different applications [2-7]. Dynamic Analysis by Laser Stimulation (DALS) is one of the known SDL implementations [8-11]. However, there are cases where the failure is occurring at a temperature where the laser alone is not sufficient to effectively induce a change of device behavior. In these situations, the analyst needs to think out of the box by understanding how the device will react to external conditions and to make necessary adjustments in DALS settings. This paper will discuss three cases that presents different challenges such as performing DALS analysis where the failing temperature is too high for the laser to induce a change of behavior from ambient temperature, cold temperature failure, complex triggering (Serial Peripheral Interface, SPI), and using an internal signal as input for DALS analysis. The approach used for a successful DALS analysis of each case will be discussed in detail.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jing Shang ◽  
Liang Zhang ◽  
Xinyu Li ◽  
Shuping Zhang

Abstract Background In high latitude grassland habitats, altricial nestlings hatching in open-cup nests early in the breeding season must cope with cold temperature challenges. Thyroid hormones (triiodothyronine, T3 and thyroxine, T4) and corticosterone play a crucial role in avian thermoregulation response to cold. Investigating the endocrine response of altricial nestlings to temperature variation is important for understanding the adaptive mechanisms of individual variation in the timing of breeding in birds. Methods We compared nest temperature, ambient temperature, body temperature, plasma T3, T4 and corticosterone levels in Asian Short-toed Lark (Alaudala cheleensis) nestlings hatching in the early-, middle-, and late-stages of the breeding season in Hulunbuir grassland, northeast China. Results Mean nest temperature in the early-, middle- and late-stage groups was − 1.85, 3.81 and 10.23 °C, respectively, for the 3-day-old nestlings, and 6.83, 10.41 and 11.81 °C, respectively, for the 6-day-old nestlings. The nest temperature significantly correlated with body temperature, plasma T3, T4 and corticosterone concentrations of nestlings. Body temperature of 3-day-old nestlings in the early and middle groups was significantly lower than that of the late group, but there was no significant difference between the nestlings in the early and middle groups. The T4 and T3 concentrations and the ratio of T3/T4 of both 3- and 6-day-old nestlings in the early-stage group were significantly higher compared to the middle and late groups. The corticosterone levels of 3-day-old nestlings were significantly higher in the early-stage group compared to the middle- and late-stage groups. Conclusion Nestlings hatching early responded to cold temperature by increasing thyroid hormones and corticosterone levels even in the early days of post hatching development when the endothermy has not been established. These hormones may play a physiological role in neonatal nestlings coping with cold temperature challenges.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Anissa Souissi ◽  
Jiang-Shiou Hwang ◽  
Sami Souissi

AbstractCopepod females invest a quantity of resources in their reproduction. Depending on several biotic and abiotic factors and their evolutionary history a trade-off can be commonly observed between producing a large number of smaller offspring or a small number of larger offspring. In this study, a multi-generational approach was applied to determine whether a trade-off between clutch size and egg size existed in the copepod Eurytemora affinis under different controlled conditions of temperature and salinity. This protocol was based on the follow-up of reproductive (Clutch Size ‘CS’, Egg Diameter ‘ED’) and morphological (Prosome Length ‘PL’) traits during several generations. Copepods were acclimated to cold (7 °C) and warm (20 °C) temperatures, and then their reproductive output was tested at the higher temperature of 24 °C. CS and ED were positively correlated to PL, so as a first step linear regressions between each reproductive trait and female PL were performed. The residuals from the regression lines of CS and ED with PL were calculated to remove the effect of female size. When the normalized data (residuals) of CS and ED plotted together a negative relationship between egg size and egg number revealed the existence of a trade-off. Copepod populations initially acclimated to cold temperature are commonly characterized by relatively smaller CS and larger ED. Conversely, warm temperature adapted females produced relatively larger CS and smaller ED. After transfer to a temperature of 24 °C, the ED did not change but the CS showed high variability indicating stressful conditions and no trade-off was observed. These observations suggest that E. affinis is able to modulate its reproduction depending on the encountered temperature. It seems that this copepod species can shift between a K- and an r-strategy in response to colder or warmer conditions. In a late winter-early spring like cold temperature, copepod females seem to invest more on offspring quality by producing relatively larger eggs. This ecological strategy ensures a high recruitment of the spring generation that is responsible for the strength of the maximum population size usually observed in late spring-early summer (May–June). To the contrary, at summer-like temperature, where the population density decreases significantly in the Seine estuary, copepod females seem to switch from K to r strategy by favoring offspring number compared to offspring size. Finally, the use of a higher temperature of 24 °C seems to disrupt the observed reproductive trade-off even after several generations. These results suggest that a switching between K- or r-strategy of E. affinis depends highly on temperature effects. The effect of salinity increase during a summer-like temperature of 20 °C as well as after transfer to 24 °C decreased PL and CS but the ED did not change significantly.


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