Seston supply to sea scallops (Placopecten magellanicus) in suspended culture

2001 ◽  
Vol 58 (2) ◽  
pp. 241-253 ◽  
Author(s):  
C A Pilditch ◽  
J Grant ◽  
K R Bryan

The filtration activity of dense aggregations of bivalves can locally reduce the concentration of seston, potentially limiting production. Under these conditions, the currents that supply seston cannot offset ingestion by the bivalves and the carrying capacity is exceeded. We conducted a field and modelling study to examine factors affecting seston supply to a culture of suspended sea scallops (Placopecten magellanicus) in Whitehaven Harbour, Nova Scotia. Even though seston flux to the scallops was reduced by 40% due to the attenuation of flow by culture gear, a reduction in seston concentration was not observed. The field data were then used to parameterize a quasi two-dimensional advection-diffusion model that quantified the relationship between the tidally driven seston supply and consumption by scallops. The model predicted a minimal reduction in seston concentration (<5%) within the lease (80 × 50 m), consistent with field observations. However, expanding the lease to occupy the area available for cultivation (1000 × 250 m) reduced the seston concentration in the centre of the lease by 20-50%, potentially limiting growth. Modelling results emphasized that by altering the lease geometry (lease width to length ratio), the supply of seston can be optimized.

2021 ◽  
pp. 99-106
Author(s):  
A. A. Sin’kevich ◽  
◽  
M. L. Toropova ◽  
Yu. P. Mikhailovskii ◽  
V. B. Popov ◽  
...  

The analysis of field observations of thunderclouds in India is provided. The characteristics of the cloud collection obtained from the radar and lightning detection network in the area of the city of Aurangabad (the Maharashtra province, India) are considered. The maximum radar reflectivity of thunderstorm cells, the volume of the supercooled part above the 0C isotherm, the intensity and flow of precipitation, and the frequency of electric discharges are obtained. It is shown that the frequency of electric discharges is associated with some radar parameters of thunderclouds, and this relationship depends on the stage of cloud development. Comparative field data for other regions are given.


2020 ◽  
Vol 16 (5) ◽  
pp. 935-945
Author(s):  
I.A. Zaikova

Subject. The working time of workers at any stage of economic development is a value reflecting the level of labor productivity. Any progress in productivity contributes to changes in the volume of labor costs and the number of employed. Depending on the relationship between the total volume of labor costs and the number of employed, the duration of working time per one worker may change (it may increase, decrease, or remain unchanged). Objectives. The study aims to confirm the importance of such a macroeconomic indicator as the number of employed in varying working hours. Methods. The study rests on the comparative analysis of countries with developed economies based on some indicators like dynamics of the working time fund, dynamics of the number of employed, average number of hours worked during the year per employee, etc. The analyzed timespan is 25 years (from 1991 to 2016). Results. The comparative analysis revealed that in the non-production sphere and the economy as a whole the macroeconomic determinants correlate so that the length of working time per worker reduces. When considering the analysis results for the manufacturing sector, no single trend was identified. Conclusions. One of the key factors affecting the change in working hours is the number of employed. The relationship between the working time fund and the number of employed directly determines the dynamics of working time per worker.


Author(s):  
Miyoung Lee ◽  
Yeon-Suk Kim ◽  
Mi-Kyoung Lee

Prenatal depression is an important factor in predicting postpartum depression. Most studies have assessed factors affecting prenatal depression by focusing on pregnant wives. However, the emotional and psychological aspects of both expectant parents need to be considered. Therefore, the purpose of this study was to examine the effect of spouse-related stress in expectant couples on prenatal depression and investigate the mediating effects of marital intimacy on this relationship. A total of 120 expectant couples from two cities in Korea at more than 15 weeks of completed pregnancy participated in the study. Using a structured questionnaire, we assessed the general characteristics of the participants, spouse-related stress, prenatal depression, and marital intimacy. The results revealed that four actor effects and one partner effect were significant. Marital intimacy and prenatal depression among expectant parents were affected by spouse-related stress. Moreover, spouse-related stress in the husbands completely mediated marital intimacy in pregnant wives, demonstrating partner effects on prenatal depression in pregnant wives. Therefore, it was observed that paternal factors affect prenatal depression in pregnant wives. This warrants the inclusion of husbands in marital interventions and strategies to improve marital intimacy in pregnant wives.


Energies ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2972
Author(s):  
Zhili Zuo ◽  
Jinhua Cheng ◽  
Haixiang Guo ◽  
Yonglin Li

Based on resource carrying capacity, this study used the revised theory of relative resource carrying capacity (RRCC) and introduced an innovative concept of relative fossil energy carrying capacity (RFECC), which evaluates the degree of fossil energy sustainability based on the relationship between economy, population, and environment. This study took China and the United States as the study objects, took the whole country as the reference area, and calculated the RFECC of population, economic, and environmental resources from 2000 to 2018. Therefore, based on the comparative analysis, the following conclusions were drawn: (i) there is a big difference in the RFECC between China and the United States, which is manifested in the inverted U-shaped trend in China and the U-shaped trend in the United States; (ii) the relative fossil energy carrying states in China and the United States are different, mainly reflected in the economy and environment; (iii) the gap in RFECC between China and the United States has gradually widened; in general, China’s economic RFECC is better than that of the United States, while environmental RFECC and population RFECC in the United States is better than that of China; and (iv) coal and oil should be used as a breakthrough point for the sustainable fossil energy and sustainable development for China and the United States, respectively.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yufang Xiang ◽  
Yuanyuan Zheng ◽  
Shaobo Liu ◽  
Gang Liu ◽  
Zhi Li ◽  
...  

AbstractWestern blotting (WB) is one of the most widely used techniques to identify proteins as well as post translational modifications of proteins. The selection of electroblotted membrane is one of the key factors affecting the detection sensitivity of the protein which is transferred from gel to membrane in WB. The most common used membranes are polyvinylidene fluoride (PVDF) and nitrocellulose (NC) membranes. Which membrane of these two is more suitable for WB has not been reported so far. Here, by incubating proteins which were transferred to PVDF or NC membranes with a series of antibodies and different types of lectins, we investigated the relationship between the binding ability of these two membranes to proteins or glycoproteins and the molecular weight of the target protein. The antibody re-probed ability of the two membranes was also explored. Moreover, we verified the above results by directly incubating proteins having different molecular weights onto PVDF or NC membranes. Bound proteins were stained with direct blue-71, and the staining intensity was quantitated by scanning and densitometry.


Diagnostics ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1286
Author(s):  
Junya Sato ◽  
Kazunari Nakahara ◽  
Yosuke Michikawa ◽  
Ryo Morita ◽  
Keigo Suetani ◽  
...  

Endoscopic transpapillary gallbladder drainage (ETGBD) for acute cholecystitis is challenging. We evaluated the influence of pre-procedural imaging and cystic duct cholangiography on ETGBD. Patients who underwent ETGBD for acute cholecystitis were retrospectively examined. The rate of gallbladder contrast on cholangiography, the accuracy of cystic duct direction and location by computed tomography (CT) and magnetic resonance cholangiopancreatography (MRCP), and the relationship between pre-procedural imaging and the technical success of ETGBD were investigated. A total of 145 patients were enrolled in this study. Gallbladder contrast on cholangiography was observed in 29 patients. The accuracy of cystic duct direction and location (proximal or distal, right or left, and cranial or caudal) by CT were, respectively, 79%, 60%, and 58% by CT and 68%, 55%, and 58% by MRCP. Patients showing gallbladder contrast on cholangiography underwent ETGBD with a significantly shorter procedure time and a lower rate of cystic duct injury. No other factors affecting procedure time, technical success, and cystic duct injury were identified. Pre-procedural evaluation of cystic duct direction and location by CT or MRCP was difficult in patients with acute cholecystitis. Patients who showed gallbladder contrast on cholangiography showed a shorter procedure time and a lower rate of cystic duct injury.


1979 ◽  
Vol 182 (2) ◽  
pp. 455-464 ◽  
Author(s):  
E J Harris ◽  
M Al-Shaikhaly ◽  
H Baum

Respiring rat heart mitochondria were loaded with Ca2+ and then treated with Ruthenium Red. The factors affecting the subsequent Ca2+-efflux were studied. Addition of rotenone or antimycin led to a decline of efflux except at pH values above 7.2, provided the load was less than about 80 nmol per mg of protein. Oligomycin reversed the effect of the respiratory inhibitors. Independently of respiration, efflux was stimulated by the uncoupler trifluoromethyltetrachlorbenzimadazole, by mersalyl and by thyroid hormones. The stimulated efflux could be diminished by ADP, with Mg2+ as cofactor if efflux was rapid. With respiration in progress, efflux could be stimulated by N-ethylmaleimide and 5,5′-dithiobis-(2-nitrobenzoate). The effects of mersalyl and of thyroid hormones could be diminished with dithiothreitol. In the absence of stimulating agents, the Ca2+ efflux was proportional to the load up to some critical amount, this critical amount was decreased by the agents. Thyroxine and mersalyl caused not only loss of Ca2+, but also simultaneous, but not necessarily proportional, loss of internal adenine nucleotides. Both efflux rates were kept at a low value by bongkrekic acid added before the stimulating agent. It is concluded that Ca2+ efflux is a measure of a permeability controlled by the binding of ADP (an Mg2+) to the inner membrane, and that this in turn depends on the maintenance of certain thiol gropus in a reduced form by a reaction that uses NADH and ATP and the energy-linked transhydrogenase.


2020 ◽  
pp. 017084062091095
Author(s):  
Jesper Edman ◽  
Alex Makarevich

We examine the effect of status entrenchment on the adoption of new norm-deviant organizational practices. Identifying organizational age and status mobility as factors affecting entrenchment, we extend the middle-status conformity theory by explicating how entrenchment moderates the relationship between status and adoption. Using original data from the Japanese loan syndication market, we show that young and new-in-status banks have a lower propensity to follow status-based adoption behavior than actors entrenched in the same status positions. We discuss implication of these results for the understanding of new practice adoption and organizational status effects.


2017 ◽  
Vol 9 ◽  
pp. 184797901771262 ◽  
Author(s):  
Ahmad Adnan Al-Tit

Numerous studies have been conducted to explore the individual effects of organizational culture (OC) and supply chain management (SCM) practices on organizational performance (OP) in different settings. The aim of this study is to investigate the impact of OC and SCM on OP. The sample of the study consisted of 93 manufacturing firms in Jordan. Data were collected from employees and managers from different divisions using a reliable and valid measurement instrument. The findings confirm that both OC and SCM practices significantly predict OP. The current study is significant in reliably testing the relationship between SCM practices and OP; however, it is necessary to consider cultural assumptions, values and beliefs as the impact of OC on OP is greater than the impact of SCM practices. Based on the results, future studies should consider the moderating and mediating role of OC on the relationship between SCM practices and OP.


1989 ◽  
Vol 67 (2) ◽  
pp. 589-593 ◽  
Author(s):  
F. Buscot

In the upper Rhine forests, ascocarps of Morchella rotunda (Pers.) Boudier and Mitrophora semilibera (DC.) Lév. develop at the expense of preexisting subterranean mycelial structures (connective mycelium and mycelial muffs) associated with higher plants. Field data correlate the initial extent of springtime reheating of soil with ascocarp maturation and suggest that mycelial muffs may be storage and resistance structures formed as early as the summer preceding the spring fruiting. This suggests morels are biennial.


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