Attraction and repulsion of mobile wild organisms to finfish and shellfish aquaculture: a review

Knowledge of aquaculture–environment interactions is essential for the development of a sustainable aquaculture industry and efficient marine spatial planning. The effects of fish and shellfish farming on sessile wild populations, particularly infauna, have been studied intensively. Mobile fauna, including crustaceans, fish, birds and marine mammals, also interact with aquaculture operations, but the interactions are more complex and these animals may be attracted to (attraction) or show an aversion to (repulsion) farm operations with various degrees of effects. This review outlines the main mechanisms and effects of attraction and repulsion of wild animals to/from marine finfish cage and bivalve aquaculture, with a focus on effects on fisheries-related species. Effects considered in this review include those related to the provision of physical structure (farm infrastructure acting as fish aggregating devices (FADs) or artificial reefs (ARs), the provision of food (e.g. farmed animals, waste feed and faeces, fouling organisms associated with farm structures) and some farm activities (e.g. boating, cleaning). The reviews show that the distribution of mobile organisms associated with farming structures varies over various spatial (vertical and horizontal) and temporal scales (season, feeding time, day/night period). Attraction/repulsion mechanisms have a variety of direct and indirect effects on wild organisms at the level of individuals and populations and may have implication for the management of fisheries species and the ecosystem in the context of marine spatial planning. This review revealed considerable uncertainties regarding the long-term and ecosystem-wide consequences of these interactions. The use of modelling may help better understand consequences, but long-term studies are necessary to better elucidate effects

The Impact of Error-Management Climate, Error Type and Error Originator on Auditors’ Reporting Errors Discovered on Audit Work Papers

We examine factors affecting the auditor’s willingness to report their own or their peers’ self-discovered errors in working papers subsequent to detailed working paper review. Prior research has shown that errors in working papers are detected in the review process; however, such detection rates only rarely exceed 50% of the seeded errors. Hence, measures that encourage auditors to be alert to their own (or their peers’) potential errors any time they revisit the audit working papers may be valuable in detecting such residual errors and potentially correcting them before damage occurs to the audit firm or its client. We hypothesize that three factors affect the auditor’s willingness to report post detailed review discovered errors: the local office error-management climate (open versus blame), the type of error (mechanical versus conceptual) and who committed the error (the individual who committed the error (self) or a peer). Local office error-management climate is said to be open and supportive where errors and mistakes are accepted as part of everyday life as long as they are learned from and not repeated. In alternative, a blame error-management climate focuses on a “get it right the first time” culture where mistakes are not tolerated and blame gets attached to those admitting to or found committing such errors. We find that error-management climate has a significant overall effect on auditor willingness to report errors, as does who committed the error originally. We find both predicted and unpredicted significant interactions among the three factors that qualify these observed significant main effects. We discuss implications for audit practice and further research

Multiple dimensions of health locus of control in a representative population sample: ordinal factor analysis and cross-validation of an existing three and a new four factor model

<p>Abstract</p> <p>Background</p> <p>Based on the general approach of locus of control, health locus of control (HLOC) concerns control-beliefs due to illness, sickness and health. HLOC research results provide an improved understanding of health related behaviour and patients' compliance in medical care. HLOC research distinguishes between beliefs due to Internality, Externality powerful Others (POs) and Externality Chance. However, evidences for differentiating the POs dimension were found. Previous factor analyses used selected and predominantly clinical samples, while non-clinical studies are rare. The present study is the first analysis of the HLOC structure based on a large representative general population sample providing important information for non-clinical research and public health care.</p> <p>Methods</p> <p>The standardised German questionnaire which assesses HLOC was used in a representative adult general population sample for a region in Northern Germany (N = 4,075). Data analyses used ordinal factor analyses in LISREL and Mplus. Alternative theory-driven models with one to four latent variables were compared using confirmatory factor analysis. Fit indices, chi-square difference tests, residuals and factor loadings were considered for model comparison. Exploratory factor analysis was used for further model development. Results were cross-validated splitting the total sample randomly and using the cross-validation index.</p> <p>Results</p> <p>A model with four latent variables (Internality, Formal Help, Informal Help and Chance) best represented the HLOC construct (three-dimensional model: normed chi-square = 9.55; RMSEA = 0.066; CFI = 0.931; SRMR = 0.075; four-dimensional model: normed chi-square = 8.65; RMSEA = 0.062; CFI = 0.940; SRMR = 0.071; chi-square difference test: p < 0.001). After excluding one item, the superiority of the four- over the three-dimensional HLOC construct became very obvious (three-dimensional model: normed chi-square = 7.74; RMSEA = 0.059; CFI = 0.950; SRMR = 0.079; four-dimensional model: normed chi-square = 5.75; RMSEA = 0.049; CFI = 0.965; SRMR = 0.065; chi-square difference test: p < 0.001). Results were confirmed by cross-validation. Results based on our large community sample indicated that western general populations separate health-related control-beliefs concerning formal and informal assistance.</p> <p>Conclusions</p> <p>Future non-clinical HLOC studies in western cultures should consider four dimensions of HLOC: Internality, Formal Help, Informal Help and Chance. However, the standardised German instrument needs modification. Therefore, confirmation of our results may be useful. Future research should compare HLOC structure between clinical and non-clinical samples as well as cross-culturally.</p

Anelastic and Viscoelastic Behaviour of Amorphous Zr65Cu17.5Ni10Al7.5 in the Range of the Glass Transition

Reversible (anelasticity) and the irreversible (viscosity) relaxations in the amorphous alloy Zr65Cu17.5Ni10Al7.5 have been investigated by means of creep and mechanic after-effect measurements of the shear strain, which were performed in an inverted torsion pendulum. For the evaluation of the measurements a new relaxation model is proposed which takes into account that in the range of the glass-transition temperature Tg the local atomic arrangement is steadely changing. By introducing a finite mean life time τ of local structure units we are able to trace the origin of the anelasticity and the viscosity to the same atomic relaxation processes. The temperature dependence of the viscosity η measured between 560 K and 668 K shows a jump in the activation energy at Tg = 606 K from 2.1 eV below Tg to 5.6 eV above Tg

Recent Progress in the Theory of Bordoni-Type Relaxation Processes

While it is well established by experiment that the relaxation processes in face-centred cubic metals discovered by P. G. Bordoni as well as related phenomena are due to the thermally activated formation of kink pairs on dislocation lines, the quantitative aspects of the theory as developed since Bordoni's discovery still reveal gaps or even inconsistencies. The paper reports on recent progress in solving the open problems. An improved formula has been derived for the mean number of (thermal as well as geometrical) kinks on dislocation segments of length L under the action of a homogeneous applied shear stress. It is shown how the change-over in the temperature dependence of the number of kink pairs, nkp, from the low-temperature exp(-2Hk/kT) law to the high temperature exp(-Hk/kT) law depends on L, on the number of geometrical kinds ng, and on the applied stress. Hk is the formation energy of an isolated kink. The mean dislocation velocity, which is the essential quantity determining the relaxation time, shows a similar temperature dependence. The dependence of the relaxation time and strength of the relaxation process by kink-pair generation on internal stresses is discussed in some detail

Diatomic Hydrogen-Metal Complexes in Dilute Palladium-Rare Earth Alloys

The internal friction of hydrogen-doped dilute Pd100-xREx alloys (RE = Gd, Ce) (x = 1 ...9) shows three maxima in the temperature range between 10 K and 300 K. These maxima are interpreted as Zener peak of hydrogen in the β-phase (Ha = 0.11 eV), Snoek-Köster peak (Ha = 0.18 eV) and reorientation peak of diatomic H-RE complexes. The relaxation strength of the latter peak is independent of the RE concentration and depends linearly on the hydrogen content. A value of |λ1-λ2| = 0.036 for the elastic anisotropy of the H-RE complexes is obtained. In alloys with RE = Gd this peak saturates when the hydrogen content is comparable with the RE concentration, whereas in the case of RE = Ce saturation at much lower hydrogen contents is observed. The activation enthalpy Ha of the H-RE reorientation varies with the RE as well as with the H concentration and lies between 0.18 eV and 0.26 eV. The activation enthalpy and the width of the peak increase with increasing RE content. Increasing the H content leads to a decrease of Ha. These features of the reorientation of diatomic H-RE complexes are discussed in terms of a distribution of site enthalpies caused by elastic long-range interaction between a H-RE complex and further RE atoms in its vicinity

Dislocation Relaxation Processes due to Kink Migration

The interpretation of the Bordoni relaxation and of related relaxation phenomena in terms of the thermally activated, stress-assisted formation of kink pairs on dislocation lines is well established on assuming that the migration of kinks along dislocation lines is described by a high kink mobility µk. This assumption, however, is not valid if the activation enthalpy for kink migration, Hm, is comparable with or even larger than the formation enthalpy of kink pairs or if even when small compared with the formation energy of kinks, Hm is larger than the lowest thermal energies accessible in internal friction experiments. In those cases not only migration but also annihilation and trapping of thermal kink pairs may produce internal friction peaks. The difference-differential equations governing the thermal kink pairs evolution along dislocation lines under the action of a homogeneous applied shear stress are set up and their time-dependent solutions characterized by a set of relaxation times. It is shown how to obtain, from these solutions, the internal friction spectrum under conditions that are experimentally realized. Quantitative descriptions of geometrical kink migration and kink pair evolution are compared with selected experimental results