Effect of nest microclimate temperatures on metabolic rates of small carpenter bees, Ceratina calcarata (Hymenoptera: Apidae)

2020 ◽  
Vol 152 (6) ◽  
pp. 772-782
Author(s):  
Miriam H. Richards ◽  
Andrea Cardama Garate ◽  
Mary Shehata ◽  
Derrick Groom ◽  
Glenn J. Tattersall ◽  
...  

AbstractSmall carpenter bees (Ceratina calcarata Robertson) (Hymenoptera: Apidae) build their nests in both sunny and shady sites, so maternal decisions about nest sites influence the thermal environment experienced by juveniles throughout development. A previous study demonstrated that when larvae and pupae were raised in the laboratory at room temperature, those from sunny nests developed more slowly than those from shady nests. This suggested that bees developing in sunny nests slowed their metabolism or that bees developing in shady nests increased their metabolism. To test this hypothesis, we performed a field experiment in which bees nested in full sun, full shade, or semi-shade. We brought larvae and pupae into the laboratory to be raised to adulthood at room temperature and measured their metabolic rates (VCO2) at 10 °C, 25 °C, and 40 °C. As expected, bees had higher VCO2 at higher test temperatures, but significant interaction also occurred between test temperature and field treatment, such that bees from sunny nests exhibited higher metabolic rates at 40 °C. Because small carpenter bees frequently nest in full sun, adaptation to high nest temperatures may involve activation of thermal protection mechanisms at the cost of slower development.

2021 ◽  
Vol 2 (2) ◽  
pp. 325-334
Author(s):  
Neda Javadi ◽  
Hamed Khodadadi Tirkolaei ◽  
Nasser Hamdan ◽  
Edward Kavazanjian

The stability (longevity of activity) of three crude urease extracts was evaluated in a laboratory study as part of an effort to reduce the cost of urease for applications that do not require high purity enzyme. A low-cost, stable source of urease will greatly facilitate engineering applications of urease such as biocementation of soil. Inexpensive crude extracts of urease have been shown to be effective at hydrolyzing urea for carbonate precipitation. However, some studies have suggested that the activity of a crude extract may decrease with time, limiting the potential for its mass production for commercial applications. The stability of crude urease extracts shown to be effective for biocementation was studied. The crude extracts were obtained from jack beans via a simple extraction process, stored at room temperature and at 4 ℃, and periodically tested to evaluate their stability. To facilitate storage and transportation of the extracted enzyme, the longevity of the enzyme following freeze drying (lyophilization) to reduce the crude extract to a powder and subsequent re-hydration into an aqueous solution was evaluated. In an attempt to improve the shelf life of the lyophilized extract, dextran and sucrose were added during lyophilization. The stability of purified commercial urease following rehydration was also investigated. Results of the laboratory tests showed that the lyophilized crude extract maintained its activity during storage more effectively than either the crude extract solution or the rehydrated commercial urease. While incorporating 2% dextran (w/v) prior to lyophilization of the crude extract increased the overall enzymatic activity, it did not enhance the stability of the urease during storage.


2021 ◽  
Vol 108 (March) ◽  
pp. 1-5
Author(s):  
Kanchana N ◽  
◽  
Veeranan Arun Giridhari V ◽  
Vijayalakshmi R ◽  
◽  
...  

The present study aimed to developwhey-based herbal beverages and to evalautetheir physical, chemical, and sensory properties. The pH, titrable acidity (% lactic acid) and total soluble solids (⁰Brix) of whey used for the development of whey based herbal drinks were found to be 5.21, 0.23 and 6.4 respectively. The proximate composition of whey such as lactose (g/100g), protein (g/100g) and fat (g/100g) were 4.28, 0.28 and 0.13, respectively. The whey (65%), sugar (11%), H1 - brahmi extract (3%), H2 - mint extract (2%) and H3 - jaljeera powder (0.15%) were standardized for the formulation of whey-based herbal drinks. Among the three variations, whey-based jaljeera drink (H3) scored the highest sensory acceptability. The pH, titrable acidity (% citric acid), total soluble solids (⁰Brix), lactose (g/100g), protein (g/100g), fat (g/100g), total reducing sugar (g/100g), total sugar (g/100g), calcium (mg/100g), ascorbic acid (mg/100g) and total phenol (mgGAE/100g) of whey-jaljeera drink (H3) were 5.24, 0.21, 12.0, 2.78, 0.46, 0.30, 3.43, 14.43, 55.27, 0.12 and 14.26, respectively. The sensory attributes retention was high in glass (P2) compared to PET (P1). The sensory attributes were gradually decreased during the storage of room temperature (R1) than refrigerated temperature (R2). The cost of the formulated whey brahmi drink, whey mint drink, and whey jaljeera drinks were Rs.18.33/250ml, Rs.20.20/250ml and Rs.14.75/250ml, respectively. The study concluded that nutritionally rich whey-based herbal drinks can be recommended to all group of people.


1992 ◽  
Vol 165 (1) ◽  
pp. 181-194 ◽  
Author(s):  
M. A. Castellini ◽  
G. L. Kooyman ◽  
P. J. Ponganis

The metabolic rates of freely diving Weddell seals were measured using modern methods of on-line computer analysis coupled to oxygen consumption instrumentation. Oxygen consumption values were collected during sleep, resting periods while awake and during diving periods with the seals breathing at the surface of the water in an experimental sea-ice hole in Antarctica. Oxygen consumption during diving was not elevated over resting values but was statistically about 1.5 times greater than sleeping values. The metabolic rate of diving declined with increasing dive duration, but there was no significant difference between resting rates and rates in dives lasting up to 82 min. Swimming speed, measured with a microprocessor velocity recorder, was constant in each animal. Calculations of the aerobic dive limit of these seals were made from the oxygen consumption values and demonstrated that most dives were within this theoretical limit. The results indicate that the cost of diving is remarkably low in Weddell seals relative to other diving mammals and birds.


2020 ◽  
Vol 158 (5) ◽  
pp. 431-437
Author(s):  
Michael Kam ◽  
Shaher El-Meccawi ◽  
Arieh Brosh ◽  
A. Allan Degen

AbstractSheep are grazers and goats are intermediate feeders. By employing O2 consumption and heart rate measurements, resting metabolic rate (RMR) and field metabolic rate (FMR) were determined in four male fat-tailed Awassi sheep (44.0 ± 3.94) and four male Baladi goats (35.5 ± 5.42 kg) that were co-grazing natural pasture in the Negev Desert. There were 67.7 ± 3.75 g DM/m2 of herbaceous vegetation biomass, which was rapidly becoming senescent and more fibrous. We hypothesized that FMR of these desert-adapted ruminants would be relatively low when compared to other sheep and goat breeds, as animals in arid areas tend to have low metabolic rates. Both sheep (n = 6) and goats (n = 6) foraged 71% of the allotted 11 h free-pasture period; however, sheep grazed more than goats (P < 0.001); whereas goats browsed more than sheep (P < 0.001). RMR was higher (P = 0.007) in sheep than in goats (529 ± 23.5 v. 474 ± 25.4 kJ/kg0.75 BW/d), but FMR did not differ between species (618 ± 55.7 v. 613 ± 115.2 kJ/kg0.75 BW/d). In addition, the cost of activities, as a proportion of FMR, did not differ between sheep and goats; FMR increased by 89 kJ/kg0.75 BW/d or 17% in sheep and by 138 kJ/kg0.75 BW/d or 29% in goats. In comparing FMRs of sheep and goats in this study with these species in other studies, differences were inconsistent and, therefore, our hypothesis was not supported.


2018 ◽  
Vol 196 ◽  
pp. 04078
Author(s):  
Elena Malyavina ◽  
Anastasya Frolova

A large number of factors influence the economically feasible heat transfer resistance of the building enclosing structures. First of all, it is the cost of insulation and heat for the building heating in the cold season. As shown by studies, it is not enough for air-conditioned buildings. The result depends on the mode of the building operation in time and the heat load on the heating and cooling systems. Therefore, in addition to these significant factors of economic feasibility of the thermal protection level, there are the cost of electricity for the production of cold for cooling the building, the cost of the building heating and cooling systems and the cost of connection to power supply networks. The got result is important to convey to the professional community in a clear and compact form. In the present work the buildings of administrative and office purpose are considered, the working day of which lasts from 9-00 to 18-00 hours with different specific heat supply from 0 to 80 W/m2 on the estimated area during working hours. Generalization of the research results is made on the basis of specific heat protection characteristics of the building, which is a product of the overall heat transfer coefficient of the building and the compactness coefficient. The total heat transfer coefficient of the building characterizes the heat losses and the heat inflows to the building through the enclosing structures, and the compactness coefficient can serve as an indicator of the surface area of the building, which is covered with insulation. For these buildings provision has been made for identification of the areas of the total discounted cost combination for all of the above components and the specific heat protection characteristics of the building relating to the feasibility of the specified level of the thermal protection.


2019 ◽  
Vol 29 (6) ◽  
pp. 775-782
Author(s):  
Masanari Ukai ◽  
Tatsuo Nobe

In this study, the authors evaluated clothing insulation and changes in the metabolic rate of individuals in an office environment to determine thermal comfort. Clothing was evaluated using a questionnaire completed by 1306 workers in nine offices. The metabolic rates of 86 workers in three offices were measured using a physical activity meter. The distribution of the temperature at which a person in the room perceived a neutral thermal sensation was then calculated from the determined metabolic rates and clothing insulation values. The results demonstrate a noticeable difference between the average and most frequent values during the summer. Moreover, the required temperature distribution is not normal; rather, it is broad and skewed to the low-temperature side. Therefore, even if a thermally uniform environment is provided at the average required temperature by preventing temporal and spatial variations in the thermal environment, complaints of an unacceptably hot thermal environment are more likely to occur than complaints of an excessively cold thermal environment.


2019 ◽  
Vol 111 ◽  
pp. 06035
Author(s):  
Sihwan Lee

While air conditioner is running, opening doors and windows is a great way to reduce operating efficiency and undermine the air conditioning system’s ability to bring the indoor to a comfortable temperature. The purpose of this study is to evaluate the heat loss and thermal environment through the door open while air conditioner running. To achieve this goal, using full-scale measurement with the commercial store during the cooling period, the infiltration rate, thermal environment and energy consumption of air conditioners with door opened and door closed state were measured. The measured results show that the infiltration rate at the door opened state was increased by about 21.3 times compared to the door closed state. When the set temperature of the air conditioner was 24 °C, the room temperature in the opening gate cooling was measured to be about 5 °C higher than the closing gate cooling. However, the energy consumption was measured approximately 12 kWh/day and there was no difference with door state. This means that the energy consumption is not increased if the indoor air temperature would not reach the set point temperature of air conditioner.


2018 ◽  
Vol 28 (4) ◽  
pp. 454-469 ◽  
Author(s):  
Wonyoung Yang ◽  
Myung-Jun Kim ◽  
Hyeun Jun Moon

This study investigates effects of room air temperature and background noise on the perception of floor impact noises in a room. Floor impact noises were recorded in apartment buildings and were presented in an indoor climate chamber with background noise for subjective evaluation. Thirty-two participants were subjected to all combinations of three thermal conditions (20%C, 25%C, 30%C and relative humidity 50%), four background noise types (Babble, Fan, Traffic and Water), three background noise levels (35 dBA, 40 dBA and 45 dBA) and four floor impact noises (Man Jumping, Children Running, Man Running and Chair Scraping). After a 1-h thermal adaptation period for each thermal condition, the participants were asked to evaluate their thermal and acoustic perceptions. Statistically significant effects were found for the room air temperature and background noise level on the perception of the floor impact noises. Noisiness, loudness and complaints of floor impact noise increased with increasing room temperature and background noise level. Annoyance of floor impact noise showed a peak in acceptable thermal environment for general comfort. Room air temperature was a dominant non-auditory factor contributing to floor impact noise annoyance, while the floor impact noise level influenced the floor impact noise loudness and the floor impact noisiness was almost equally affected by the room temperature, background noise level and floor impact noise level. Further investigation is needed to fully understand the combined perception of floor impact noise under various indoor environmental conditions.


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