A strong ethical culture is the key to any organization’s long-term success. The purpose of this research was to investigate the link between an organization’s ethical culture and its effect on ...workers’ well-being, as well as to test the construct validity of the Corporate Virtue Scale (CEV). In South Africa’s Buffalo Municipality, 277 managers from different government agencies made up the sample. The eight-factor CEV scale was validated through a confirmatory factor analysis. Employees’ stress and emotional exhaustion were linked to their views on the prevalence of an ethical culture in public agencies. The results of this study show that an organization’s ethical culture significantly affects its employees’ quality of life on the job. The CEV scale was found to have construct validity, proving its reliability and validity in practice. The government is urged to prioritize the streamlining of regulations and processes that foster an ethical culture in public institutions.
Koi sleepy disease (KSD) of koi and farmed and wild carp receives considerable attention especially due to the economic significance of carp farming. Since the 1950s, the cultivation and breeding of ...carp species have been intensively incorporated into aquacultural food production and international fish trade. Thereby driving the spread of carp diseases to several localities. Nearly a half-century has passed since the 1974 discovery and isolation in Japan of KSD's causative agent, carp edema virus (CEV). Infections caused by CEV continue to emerge increasingly in carp populations around the globe with variation in disease occurrence respective to the host environment. CEV has been categorized in the family poxviridae and distinct genogroups of viral mutations are molecularly identified from virus isolates in different localities. Scientific knowledge about this virus, however, remains inadequate relative to the needs of researchers in aquatic health. The current review draws an attention to the nature of CEV as a non-classified poxvirus and its interaction with host and environment based upon the existing literature and the author's views.
•CEV infections continue to emerge increasingly in carp populations around the globe•Multiple and distinct genogroups of viral mutations have been molecularly identified•Massive carp breeding and culture for international trade contribute to KSD spread•The knowledge gap in CEV understanding impedes serious progress for disease control•The theme of this review has potential prospective application in CEV study
A poxvirus named carp edema virus (CEV), is the causative agent of carp edema virus disease (CEVD), which is an emerging disease of global concern that may cause high rates of morbidity and mortality ...in ornamental koi and common carp and. Common carp (Cyprinus carpio) is the most important fish species for warm‐water aquaculture in Serbia. CEVD was first time detected in Serbia in 2017. During 2017-2020 period, increasing number of CEVD outbreaks in carp farms is reported. Carp were collected from farms in different regions of Serbia from 2017 to 2020. The fish were sampled for disease diagnosis because they exhibited lethargy and anorexia, which eventually led to mortality. Mortality started with clinical signs of hypoxia while fish swam slowly without escaping reactions. The gills were pale and covered with a thick mucus layer. In advanced cases, the lesions in the gills turned into a necrotizing form. A moderate to high amount of opportunistic freshwater bacteria were isolated from gills of diseased fish. By performing real-time PCR, CEV was detected in 38 samples of diseased carps from 21 carp farms. These outbreaks further confirm the spread of CEVD and the need for practitioners to be vigilant for outbreaks of this disease. To prevent further spreading of the disease, it is very important to introduce CEV testing before fish movement. To avoid further transmission of the virus to common carp populations in Serbia, testing of CEV should become part of fish disease surveillance programs. Fish health service should be aware of the presence of CEV in Serbia which may result in high losses in carp aquaculture. Action should be taken also to prevent transmission of CEV to carp populations in open waters.
•Closed-form formula for conditional moments of generalized NLD-CEV process.•Closed-form formulas for conditional and unconditional moments of a nonlinear drift CEV process are presented in ...simplified form.•Well-known instances deduced by the nonlinear drift CEV process are the Cox-Ingersoll-Ross and inverse Feller processes or 3/2-stochastic volatility model.•Sufficient conditions of existence and uniqueness of a positive pathwise strong solution for time-dependent parameter functions are provided.
This paper studied a generalized case of the constant elasticity of variance diffusion (CEV) process whereas the drift term is substantially nonlinear in the short rate. Well-known instances deduced by this process are the extended Cox–Ingersoll–Ross (ECIR) process and the extended inverse Feller (EIF) process or 3/2-stochastic volatility model (SVM). We found particular sufficient conditions of existence and uniqueness of a positive pathwise strong solution for time-dependent parameter functions, and obtained closed-form formulas for conditional moments based on Feynman–Kac theorem. The accuracy and validity of the formulas were further investigated based on Monte Carlo simulations.
In this paper, we study the degenerate parabolic equations of the formut=ai′j′ui′j′+2xn1+δ2ai′nui′n+xn1+δannunn+bi′ui′+xn1+δ2bnun+cu+f derived from the Constant Elasticity of Variance model in ...mathematical finance. Under certain smoothness conditions on coefficients and forcing term, the smoothness of solution for these problems is proved. Since the solution cannot be considered smooth with standard differentiability, we introduced a suitable weighted norm that makes the solution smooth. Using the weighted norm, we define the weighted Hölder space Csk,2+α and establish Schauder theory for Csk,2+α regularity.
Carp edema virus (CEV) is a poxvirus associated with outbreaks of clinical disease that may lead to high mortality in both koi and common carp populations, potentially causing severe economic losses ...for carp aquaculture and the global koi trade. Therefore, the establishment of a sensitive and specific assay for detection of CEV is an essential requirement for the prevention of further spread of this emerging viral disease. In this study, a novel droplet-digital PCR (ddPCR) assay, targeting the p4a gene of CEV was developed. The assay exhibits good linearity, repeatability and reproducibility. Linearity was maintained at extremely low concentrations of CEV nucleic acid templates. The detection limit of ddPCR was 2.2 ± 0.26 copies of CEV DNA per reaction (n = 8), which represents a greater sensitivity than the quantitative PCR (qPCR) assay. Specificity analysis showed that the ddPCR assay for CEV had no cross-reactivity with other important aquatic pathogens. In clinical diagnosis of 151 koi and common-carp samples, 58 and 45 tested positively by ddPCR and qPCR assays, respectively. The overall agreement between the two assays was 91.39% (138/151). Linear regression analysis demonstrated a significant correlation between ddPCR and qPCR results with an R2 value of 0.9627. Our findings indicate that the ddPCR assay could provide a robust diagnostic tool for the sensitive detection of CEV, even in samples with a low viral load.
•A novel ddPCR assay targeting the p4a gene was developed for sensitive and specific detection of the CEV virus.•The assay displayed good sensitivity, specificity, within experimental repeatability and across experimental reproducibility.•The ddPCR assay provides a robust diagnostic tool for sensitive detection and accurate quantitation of CEV DNA, even in samples with low viral load.
The sub-fractional CEV model Araneda, Axel A.; Bertschinger, Nils
Physica A,
07/2021, Volume:
573
Journal Article
Peer reviewed
Open access
The sub-fractional Brownian motion (sfBm) is a stochastic process, characterized by non-stationarity in their increments and long-range dependence, considered as an intermediate step between the ...standard Brownian motion (Bm) and the fractional Brownian motion (fBm). The mixed process, a linear combination between a Bm and an independent sfBm, called mixed sub-fractional Brownian motion (msfBm), keeps the features of the sfBm adding the semi-martingale property for H>3∕4, is a suitable candidate to use in price fluctuation modeling, in particular for option pricing. In this note, we arrive at the European Call price under the Constant Elasticity of Variance (CEV) model driven by a mixed sub-fractional Brownian motion. Empirical tests show the capacity of the proposed model to capture the temporal structure of option prices across different maturities.
Carp edema virus (CEV), a member of the family Poxviridae, is the etiologic agent of carp edema virus disease, also known as the koi sleepy disease (KSD). The disease is important across the world ...because it increases mortality rates in common carp and koi carp. From autumn 2020 to spring 2021, gills and internal organs were collected from suspected common carps cultured in twenty Iranian farms in Khuzestan, Gilan, and Mazandaran provinces. The presence of CEV was confirmed by molecular diagnosis. PCR was performed using specific primers to amplify the p4a gene, and positive samples were subsequently sequenced. Phylogenetic analysis assigned them to CEV genogroup I, and they shared high nucleotide sequence similarity with CEVs from Italy, Hungary, Iraq, Poland, the United States, and the Czech Republic. The results confirmed the presence of CEV in Iranian freshwater aquaculture after five years of observing clinical symptoms strongly reminiscent of CEV disease. The results also warned of the spread of the virus throughout the continent and point to the need to implement restrictions on the fish trade. Further studies are needed to determine the full-genome sequences of circulating viruses in order to provide insights into the epidemiology of fish viruses in Iran and the region.
•The first report of carp edema virus (CEV) in Iran.•Phylogenetic analysis indicated that Iranians strain has a genetic relationship with CEVs detected in Europe, USA, and Iraq.•Phylogenetic analysis showed that the Iranian CEVs were classified into genogroup I.
In this paper, we study a double obstacle problem in partial differential equation that arises in an optimization problem in finance. Precisely, we consider the double obstacle problem which is ...related to the optimal investment problem with proportional transaction costs of an investor with the logarithmic utility in finite time under the constant elasticity of variance (CEV) model.
First, we construct a solution of the double obstacle problem and prove the monotonicity of its free boundaries. From the solution to the double obstacle problem, we construct the solution of the optimization problem. Hence, our result regarding monotonicity indicates the optimal strategy for the optimization problem.
CEV model equipped with the long-memory Fallah, Somayeh; Mehrdoust, Farshid
Journal of computational and applied mathematics,
June 2021, 2021-06-00, Volume:
389
Journal Article
Peer reviewed
In this paper, we define the mixed fractional Constant Elasticity of Variance (CEV) process exploiting a transfer equation. This transformation enables us to shift non-linearity from the volatility ...coefficient into the drift one and accordingly, the problem can be more easily studied. We confirm the existence of a unique positive solution to the transfer equation and verify the conditions under which the probability that, on any fixed finite interval, the mixed fractional CEV process does not hit zero tends to 1 (by some simulation, we illustrate more). Next, some parameters of the process are estimated and finally, we examine the ability of this process to model a financial market.
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