scholarly journals Positive Effects of Fast Growth on Locomotor Performance in Pelagic Fish Juveniles: In Contrast to Existing Evidence

Author(s):  
Masahiro Nakamura ◽  
Michio Yoneda ◽  
Taizo Morioka ◽  
Akinori Takasuka ◽  
Nozomi Nishiumi

Abstract Many laboratory experiments on aquatic vertebrates that inhabit closed water or coastal areas have highlighted negative effects of fast growth on swimming performance. Nonetheless, field studies on pelagic fishes have provided evidence of survival advantages of faster growing individuals. To reconcile this contradiction, we examined the relationship between growth rate and swimming performance as a continuous function for juveniles of chub mackerel (scomber japonicus) using 3D tracking analysis. For experiments, 20, 24, 27 and 30 days-post-hatch individuals within the size range of 14.5–25.3 mm were used. We found that the growth–swimming (burst speed) relationship in chub mackerel was substantially positive and it was suggested to be supported by morphological traits such as muscle area, which also positively correlated with growth rate. This finding is consistent with field observations showing selective survival of fast-growing individuals of this species, reconciling the current contradiction between laboratory experiments and field observations. Growth was suggested to trade off with swimming performance, as reported in many previous studies, when it was extremely fast. Therefore, a dome-shaped quadratic curve described the relationship between growth rate and burst speed better than a linear or generalized linear model. These results, obtained from the rarely tested offshore species, strongly suggests the importance of experimental verification using animals that inhabit various types of habitats in understanding the principles underlying the evolution of growth–locomotor relationship.

1995 ◽  
Vol 73 (11) ◽  
pp. 2165-2167 ◽  
Author(s):  
Alan S. Kolok ◽  
James T. Oris

The objective of this study was to test the hypothesis that the specific growth rate of male fathead minnows (Pimephales promelas) was positively correlated with swimming performance. Subadult fish were allowed to grow into adults over a period of 31 – 55 days, after which the critical swimming speed of each fish was determined. Variation in critical swimming speed was substantial (greater than 50%), and a significant positive correlation was found between number of growing days and critical swimming speed, whereas a significant negative correlation was found between specific growth rate and critical swimming speed. A multiple regression using specific growth rate and number of growing days explained over 47% of the variation in swimming performance. Fathead minnows that grow fast are poor swimmers, suggesting a trade-off between swimming performance and specific growth rate in this species.


2020 ◽  
Vol 90 (5) ◽  
pp. 485-492
Author(s):  
Snježana Kužir ◽  
◽  
Krešimir Drašner ◽  
Krešimir Matanović ◽  
Lucija Bastiančić ◽  
...  

The relationship between growth rate and ossification is not consistent among fish. In some species, fast-growing individuals ossify earlier, while in other species, a trade-off between growth rate and ossification exists. This research was conducted to test the hypothesis about the existence of a trade-off mechanism in common carp offspring. For this purpose, specimens from two groups of common carp offspring (96 in total) with different growth rates were sampled at multiple time points between 5 and 29 days post-hatching. The standard length was measured and presented in correlation with the days post-hatching. To evaluate the skeletal system development, whole specimens were fixed in 10% neutral buffered formalin and stained for bone and cartilage. Particular emphasis was placed on the onset of ossification in the clearly visible bones of the head, vertebral column, and fins. According to our findings, larger, fast-growing specimens ossify earlier. The hypothesis on the existence of a trade-off between fast growth and the onset of ossification in common carp was not confirmed in our study.


2021 ◽  
Vol 13 (15) ◽  
pp. 8123
Author(s):  
Delei Yang ◽  
Jun Zhu ◽  
Qingbin Cui ◽  
Qinghua He ◽  
Xian Zheng

Megaproject citizenship behavior (MCB) has been confirmed to a play vital role on megaproject performance. Although current research has argued that institution elements have had an impact on MCB diffusion, limited studies have empirically investigated the distinct effectiveness of various institution elements on driving MCB’s widespread diffusion in construction megaprojects. Based on institution theory, this study proposes a theoretical model comprising institutional elements (i.e., normative and mimetic isomorphism), owner’s support, relationship-based trust, and their effect or impact on MCB’s diffusion. Based on 171 industrial questionnaires collected from managers of contractors and designers in megaprojects. Partial least squares structural equation modeling (PLS-SEM) was used to validate the established model. The results indicated that both normative and mimetic isomorphism have positive effects on facilitating MCB diffusion, and owner’s support has shown partial mediation in promoting MCB diffusion through normative isomorphism, as well as full mediation in the promoting of MCB diffusion through mimetic isomorphism. Meanwhile, relationship-based trust exerts a positive moderating effect on the relationship between mimetic isomorphism and MCB. This study extends current literature on driving MCB diffusion from the perspective of institutional theory, contributing by providing four implications for megaprojects managers to “buy in” more extensive MCB.


2006 ◽  
Vol 25 (4) ◽  
pp. 227-236
Author(s):  
Li-Fen Liao

Sharing knowledge and firm innovation are the crucial ways to sustain competitive advantage. This study builds a nested model to test the relationship between learning organization, knowledge-sharing behavior, and firm innovation. Data gathered from 254 employees were used to examine the relationship of the learning organization to employees' knowledge-sharing behavior and firm innovation. The results indicate that open-mindedness, shared vision and trust have positive effects on both knowledge-sharing behavior and firm innovation. While commitment to learning does not shows significant relationship on knowledge-sharing behavior and firm innovation. Communication has significance on firm innovation but not significance on knowledge-sharing behavior.


2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Toru Shirahata ◽  
Hideaki Sato ◽  
Sanehiro Yogi ◽  
Kaiji Inoue ◽  
Mamoru Niitsu ◽  
...  

Abstract Background Physical inactivity due to cachexia and muscle wasting is well recognized as a sign of poor prognosis in chronic obstructive pulmonary disease (COPD). However, there have been no reports on the relationship between trunk muscle measurements and energy expenditure parameters, such as the total energy expenditure (TEE) and physical activity level (PAL), in COPD. In this study, we investigated the associations of computed tomography (CT)-derived muscle area and density measurements with clinical parameters, including TEE and PAL, in patients with or at risk for COPD, and examined whether these muscle measurements serve as an indicator of TEE and PAL. Methods The study population consisted of 36 male patients with (n = 28, stage 1–4) and at risk for (n = 8) COPD aged over 50 years. TEE was measured by the doubly labeled water method, and PAL was calculated as the TEE/basal metabolic rate estimated by the indirect method. The cross-sectional areas and densities of the pectoralis muscles, rectus abdominis muscles, and erector spinae muscles were measured. We evaluated the relationship between these muscle measurements and clinical outcomes, including body composition, lung function, muscle strength, TEE, and PAL. Results All the muscle areas were significantly associated with TEE, severity of emphysema, and body composition indices such as body mass index, fat-free mass, and trunk muscle mass. All trunk muscle densities were correlated with PAL. The product of the rectus abdominis muscle area and density showed the highest association with TEE (r = 0.732) and PAL (r = 0.578). Several trunk muscle measurements showed significant correlations with maximal inspiratory and expiratory pressures, indicating their roles in respiration. Conclusions CT-derived measurements for trunk muscles are helpful in evaluating physical status and function in patients with or at risk for COPD. Particularly, trunk muscle evaluation may be a useful marker reflecting TEE and PAL.


Author(s):  
Robin Björkas ◽  
Mariah Larsson

AbstractSex dolls are a complex phenomenon with several diverse possible emotional, sexual and therapeutic uses. They can be part of a broad variety of sexual practices, and also function as a sexual aid. However, the media discourse on sex dolls first and foremost concerns how we perceive the relationship between intimacy and technology. A critical discourse analysis of the Swedish media discourse on sex dolls reveals six themes which dominate the discourse: (a) the definition of what a human being is; (b) a discourse on the (technological and existential) future; (c) a social effort; (d) a loveless phenomenon; (e) men’s violence against women; and (f) pedophilia. Accordingly, this discourse is very conservative and normative in its view of sexuality, technology, and humanity. Overall, the dominant themes do not provide any space for positive effects of technology on human sexuality, and if they do, it is usually as a substitute for something else.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ching-Yao Lai ◽  
Laura A. Stevens ◽  
Danielle L. Chase ◽  
Timothy T. Creyts ◽  
Mark D. Behn ◽  
...  

AbstractSurface meltwater reaching the base of the Greenland Ice Sheet transits through drainage networks, modulating the flow of the ice sheet. Dye and gas-tracing studies conducted in the western margin sector of the ice sheet have directly observed drainage efficiency to evolve seasonally along the drainage pathway. However, the local evolution of drainage systems further inland, where ice thicknesses exceed 1000 m, remains largely unknown. Here, we infer drainage system transmissivity based on surface uplift relaxation following rapid lake drainage events. Combining field observations of five lake drainage events with a mathematical model and laboratory experiments, we show that the surface uplift decreases exponentially with time, as the water in the blister formed beneath the drained lake permeates through the subglacial drainage system. This deflation obeys a universal relaxation law with a timescale that reveals hydraulic transmissivity and indicates a two-order-of-magnitude increase in subglacial transmissivity (from 0.8 ± 0.3 $${\rm{m}}{{\rm{m}}}^{3}$$ m m 3 to 215 ± 90.2 $${\rm{m}}{{\rm{m}}}^{3}$$ m m 3 ) as the melt season progresses, suggesting significant changes in basal hydrology beneath the lakes driven by seasonal meltwater input.


2011 ◽  
Vol 56 (No. 5) ◽  
pp. 242-249 ◽  
Author(s):  
Z. Ledvinka ◽  
L. Zita ◽  
M. Hubený ◽  
E. Tůmová ◽  
M. Tyller ◽  
...  

We assessed the influence of the particular genotype, age of layers, feather growth-rate gene, and their mutual interactions on selected indicators of eggshell quality in six groups of hens of the laying type Dominant. The following genotypes were examined in the experiment: Barred Plymouth Rock, Dominant BPR 951 (K) strain, slow-feathering; Barred Plymouth Rock, Dominant BPR 901 (k) strain, fast-feathering; Blue Plymouth Rock, Dominant BLPR 954 (K) strain, slow-feathering; Blue Plymouth Rock, Dominant BLPR 894 (k) strain, fast-feathering; crossbreds of the above strains in the F<sub>1</sub> generation Dominant D 107 blue (K), slow-feathering and Dominant D 107 blue (k), fast-feathering. The layers were fed a feed mixture NP1 (16.64 % CP) from the 20<sup>th</sup> week of age and a feed mixture NP2 (15.02% CP) from the 42<sup>nd</sup> week. Husbandry conditions met the regular requirements of laying hens. Egg production and live weight of hens were monitored for the duration of the experiment (12 months). Eggshell quality was examined at the layers' age of 27, 35 and 56 weeks. The average hen-day egg production for the duration of the experiment (12 months) was not significantly influenced by the particular genotype or the feather growth-rate gene. The varying representation of the feather growth-rate gene significantly (P &le; 0.001) influenced the live weight; similarly, the relationship between the genotype and the representation of K/k alleles was significant. The average egg weight was influenced statistically significantly (P &le; 0.001) by the age of hens, their genotype (P &le; 0.05), feather growth-rate gene (P &le; 0.001), and the relationship between the age and genotype (P &le; 0.001). The age of hens, genotype, and the interaction of these two factors affected the egg shape index, as did the incidence of the feather growth-rate gene within the population (with a statistical significance of P &le; 0.001). The age, genotype and the feather growth-rate gene incidence within the population also significantly affected the eggshell quality indicators. In the eggshell to egg ratio, eggshell thickness and strength, an interaction was determined between the age of hens and their particular genotype. The eggshell colour was also significantly (P &le; 0.001) affected by hens' age, genotype (P &le; 0.001), as well as by the feather growth-rate gene (P &le; 0.001). No significant interaction between the age and the genotype was found for this indicator.


2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
Yuling Sun ◽  
Zehua Liu ◽  
Hui Yang

Although many studies have suggested that the relationship between different supply chain members significantly affects agricultural product quality, suppliers’ perceptions of fairness, which greatly influence their decisions on building the relationship quality, are often overlooked. Particularly, the empirical evidence to investigate the impacts of suppliers’ fairness on the relationship quality and the factors that affect the suppliers’ fairness is missing, and therefore this knowledge gap needs to be filled by new research. Herein, we conducted a survey of 450 agricultural product suppliers and systemically analyzed the impact of antecedents on fairness perception and the impact of fairness perception on relationship quality. In addition, we developed a structural equation model and found that information sharing and price satisfaction had significantly positive effects on procedural fairness and distributive fairness, respectively. Furthermore, our studies demonstrated that procedural fairness is more important in improving the relationship quality than distributive fairness. However, supplier dependence is another important impact factor, and it greatly decreases the positive effects of suppliers’ fairness on relationship quality. In summary, the study results provide several managerial implications and extend our understanding of the importance of suppliers’ fairness in the relationship quality, which involves product development with respect to the supplier’s performance.


2015 ◽  
Vol 115 (1) ◽  
pp. 88-106 ◽  
Author(s):  
Shuchih Ernest Chang ◽  
Anne Yenching Liu ◽  
Sungmin Lin

Purpose – The purpose of this paper is to evaluate privacy boundaries and explores employees’ reactions in employee monitoring. Design/methodology/approach – The research used the metaphor of boundary turbulence in the Communication Privacy Management (CPM) theory to demonstrate the psychological effect on employees. The model comprised organizational culture, CPM, trust, and employee performance in employee monitoring to further investigated the influence exerted by organizational culture and how employees viewed their trust within the organization when implementing employee monitoring. Variables were measured empirically by administrating questionnaires to full-time employees in organizations that currently practice employee monitoring. Findings – The findings showed that a control-oriented organizational culture raised communication privacy turbulence in CPM. The communication privacy turbulence in CPM mostly had negative effects on trust in employee monitoring policy, but not on trust in employee monitoring members. Both trust in employee monitoring policy and trust in employee monitoring members had positive effects on employee commitment and compliance to employee monitoring. Research limitations/implications – This research applied the CPM theory in workplace privacy to explore the relationship between employees’ privacy and trust. The results provide insights of why employees feel psychological resistance when they are forced to accept the practice of employee monitoring. In addition, this study explored the relationship between CPM and trust, and offer support and verification to prior studies. Practical implications – For practitioners, the findings help organizations to improve the performance of their employees and to design a more effective environment for employee monitoring. Originality/value – A research model was proposed to study the impacts of CPM on employee monitoring, after a broad survey on related researches. The validated model and its corresponding study results can be referenced by organization managers and decision makers to make favorable tactics for achieving their goals of implementing employee monitoring.


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