Search Results (11)

The purpose of this study is to determine the current state of angler knowledge, opinions, awareness, and use of catch-and-release (C&R) best practices and to identify the main socio-economic factors that determine attitudes and willingness to use C&R among Polish anglers. Knowledge of this issue contributes to more effective management of fisheries and fish stocks. The research was conducted through an online survey form using a technique called CAWI (Computer-Assisted Web Interview). The questionnaire used consisted of 25 questions, including basic socio-economic questions, questions about seniority, frequency, location and method of fishing, and specific factual questions related to knowledge and practices regarding C&R. A total of 1574 respondents participated in the survey. The majority of respondents were male (97.5%). The survey showed that Polish anglers are overwhelmingly willing to practice C&R: 48.8% of respondents always and 44.0% often voluntarily release the fish they catch. Statistical analysis revealed a significant relationship between the use of this practice and the age of the angler (r = 0.46; p = 0.0001). Anglers under the age of 55 were the most likely to use C&R (p = 0.0097). The majority of respondents believe that C&R is important for improving fish stocks, but their knowledge and practices in this area have serious shortcomings. Inadequate knowledge of issues such as barotrauma or safe hook types, as well as inappropriate practices such as photographing and unhooking fish, can negatively affect their survival and ultimately the status of living water resources and ecosystem quality. These shortcomings may be due to inadequate education of anglers and fishery managers. Full article

Geoffroea decorticans (Gill. ex Hook. & Arn) Burk. is a native tree of the dry areas of Northwestern and Central Argentina. Its seeds are considered waste material. The flour of seeds was analyzed as a source of nutritional and bioactive compounds. It has a low carbohydrate content, containing about 9% protein and between 10 and 14% fat. Approximately 82–84% of the fatty acids were unsaturated (oleic and linoleic acids). A high polyphenol and dietary fiber content was detected. Flavonoids and condensed tannins were the dominant phenolics. Polyphenol-enriched extracts were obtained from seed flour. The HPLC–ESI-MS/MS analysis of these concentrated extracts allowed for the identification of six compounds including C-glycosyl flavones (vitexin and isovitexin), type A procyanidins (dimer and trimer), and epicatequin gallate. Polyphenolic extracts showed antioxidant capacity and were able to inhibit enzymes (α-glucosidase and α-amylase) related to carbohydrate metabolism and (lipoxygenase) pro-inflammatory enzymes and were not toxic. Flour and polyphenolic extract from chañar seeds could be considered as new alternative ingredients for the formulation of functional foods, nutraceuticals, or food supplements. The use of the seed flour in addition to the pulp of the fruit along with the rest of the plant would encourage the propagation of this species resistant to extreme arid environments for commercial and conservation purposes to boost the regional economies of vulnerable areas of South America. Full article

This study aimed to comparatively evaluate the biomechanical behaviors of three types of dental implant restorations: a screw-and-cement-retained prosthetic system (SCRP); a cementless screw-retained prosthetic system (SRP); and a novel screwless hook-retained prosthetic system (HRP). Three-dimensional finite element analysis (FEA) was used to evaluate biomechanical behavior. A comparative study of three dental implant prostheses was performed under two loading conditions: a vertical load of 100 N and an oblique load of 100 N at an angle of 30°. Under both loading conditions, the maximum von Mises stress values in the dental implant using the HRP system were lower (21.33 MPa) than those of the SCRP system (32.91 MPa), and the stress distribution of the implant prosthetic components tended to be more favorable than that of the SCRP system. Thus, the results show that the performance of the HRP system was comparable to that of a conventional SRP system under the same conditions. Regarding stress distribution, the novel screwless HRP system presents a viable alternative implant prosthodontic system to the conventional SCRP system. Full article

Over 10% of patients undergoing aortic endograft implantation experience endoleaks within a few years. In the case of type 1a endoleaks, a crack forms between the aorta and the prosthesis collar, allowing blood to pass. This blood fills the aneurysmal sac and can lead to its rupture. None of the strategies, such as prostheses with barbs and hooks or ad hoc pharmacological therapies, can prevent the phenomenon. An alternative approach is to reduce diameter oscillations due to pulsating pressure to improve the endoprosthesis adhesion to the internal vessel walls during the initial post-implantation phases. To reach this objective, we propose to use a passive intra-aortic balloon pump (PIABP) inserted and then maintained inside the vessel immediately after the surgical procedure. We tested our hypothesis in a mechanical mock of the cardiovascular system. A silicon aorta with physiological behavior was created for this purpose. The PIABP was inflated to increasing pressures between systolic and diastolic values (120/80 mmHg). For each aorta and each condition, the variations in aortic diameter between systole and diastole, and the pressure variations, were measured. For the normal aorta, with a PIABP pressure of 110 mmHg, the variations in diameter were reduced by 38%. Assuming an endoprosthesis with a diameter of 30 mm (oversized by 5% compared to the diastolic diameter), the time the oscillations are higher than 30 mm is also reduced by 36%. The results are positive and suggest the usefulness of a biomechanical approach to the problem of type 1a endoleaks. Further in silico and clinical trials are necessary to validate the method. Full article

The use of ferronickel slag powder (FNSP) as a cementitious additional material has been supported by numerous reports. FNSP concrete has the same shortcomings as ordinary concrete, including low hardness. In this study, in order to make FNSP concrete more durable, end-hooked type steel fibers were incorporated. To understand how various elements affect the mechanical properties of steel fibers, an experiment was carried out on the mechanical properties of steel FNSP concrete (SFNSPC). FNSP’s principal ingredients, with a particle size distribution ranging from 0.5 to 100 μm and a sheet-like powder shape, are CaO, SiO₂, Al₂O₃, MgO, and others, according to tests conducted on the material’s microstructure and composition. Then, eighteen mix proportions were developed, comprising six distinct FNSP replacement rate types and three distinct steel fiber content types. Crucial metrics were evaluated and analyzed, including the relationship among the toughness, tensile strength, and compressive strength as well as slump, splitting tensile strength, compressive strength, and uniaxial compressive stress–strain curve of SFNSPC. The results showed that the slump of SFNSPC under different FNSP replacement rates decreased with increasing steel fiber volume. Steel fibers have a small but positive effect on SFNSPC’s compressive strength; nonetheless, as FNSP replacement rates increased, SFNSPC’s slump gradually decreased, though not by much. These results show that FNSP is a viable alternative cementitious material in terms of strength. Specifically, the splitting tensile strength of SFNSPC improves with an increase in steel fiber content, and the pace at which SFNSPC strength drops with an increase in the FNSP replacement rate. With varying mix proportions, the stress–strain curve trend of SFNSPC remains mostly constant, and steel fibers improve the compressive toughness of SFNSPC. After adding 0.5% and 1.0% steel fibers, the toughness index of concrete with different FNSP replacement rates increased by 8–30% and 12–43%, respectively. Full article

The fish hook is a commonly known tool used in recreational fishing, which is one of the forms of active, specialised tourism. As a component of a fishing rod, the hook is intended to be anchored into the mouth of a fish and hold the fish on the end of the line while landing it. However, in the context of the protection of living aquatic resources and Catch-and-Release (C&R) fishing, its role and significance are becoming broader. In addition to the impact of the hook type on fishing efficiency, including the Catch Per Unit Effort (CPUE), the importance of hook selection in terms of minimising the resulting damage to the tissues of caught and released fish is increasing. It appears that alternative hook types, such as barbless hooks and circle hooks, are safer for fish in the aforementioned context while not significantly reducing fishing efficiency. This review study is aimed at describing the design, types, and role of the fish hook in modern C&R angling, including the impact of the hook type on both fishing efficiency and the safety and welfare of released fish, which translates into the status and protection of living aquatic resources. The issues presented in the study highlight a number of related technical, biological and social factors that are specific to inland angling in particular. Such a holistic perspective can be used to support the effective management of recreational fishing, which, as one of the most popular human activities when in contact with water, has a very significant impact on the state of the environment and, thus, on the possibility of tourism development. Full article

In recent times, many different types of systems have been based on fractional derivatives. Thanks to this type of derivatives, it is possible to model certain phenomena in a more precise and desirable way. This article presents a system consisting of a two-dimensional fractional differential equation with the Riemann–Liouville derivative with a numerical algorithm for its solution. The presented algorithm uses the alternating direction implicit method (ADIM). Further, the algorithm for solving the inverse problem consisting of the determination of unknown parameters of the model is also described. For this purpose, the objective function was minimized using the ant algorithm and the Hooke–Jeeves method. Inverse problems with fractional derivatives are important in many engineering applications, such as modeling the phenomenon of anomalous diffusion, designing electrical circuits with a supercapacitor, and application of fractional-order control theory. This paper presents a numerical example illustrating the effectiveness and accuracy of the described methods. The introduction of the example made possible a comparison of the methods of searching for the minimum of the objective function. The presented algorithms can be used as a tool for parameter training in artificial neural networks. Full article

Electrical stimulation can be used to modulate activity within the nervous system in one of two modes: (1) Activation, where activity is added to the neural signalling pathways, or (2) Block, where activity in the nerve is reduced or eliminated. In principle, electrical nerve conduction block has many attractive properties compared to pharmaceutical or surgical interventions. These include reversibility, localization, and tunability for nerve caliber and type. However, methods to effect electrical nerve block are relatively new. Some methods can have associated drawbacks, such as the need for large currents, the production of irreversible chemical byproducts, and onset responses. These can lead to irreversible nerve damage or undesirable neural responses. In the present study we describe a novel low frequency alternating current blocking waveform (LFACb) and measure its efficacy to reversibly block the bradycardic effect elicited by vagal stimulation in anaesthetised rat model. The waveform is a sinusoidal, zero mean(charge balanced), current waveform presented at 1 Hz to bipolar electrodes. Standard pulse stimulation was delivered through Pt-Black coated PtIr bipolar hook electrodes to evoke bradycardia. The conditioning LFAC waveform was presented either through a set of CorTec^® bipolar cuff electrodes with Amplicoat^® coated Pt contacts, or a second set of Pt Black coated PtIr hook electrodes. The conditioning electrodes were placed caudal to the pulse stimulation hook electrodes. Block of bradycardic effect was assessed by quantifying changes in heart rate during the stimulation stages of LFAC alone, LFAC-and-vagal, and vagal alone. The LFAC achieved $86.2\pm 11.1\%$ and $84.3\pm 4.6\%$ block using hook (N = 7) and cuff (N = 5) electrodes, respectively, at current levels less than 110 µA_p (current to peak). The potential across the LFAC delivering electrodes were continuously monitored to verify that the blocking effect was immediately reversed upon discontinuing the LFAC. Thus, LFACb produced a high degree of nerve block at current levels comparable to pulse stimulation amplitudes to activate nerves, resulting in a measurable functional change of a biomarker in the mammalian nervous system. Full article

New developments in upper limb prostheses are based almost exclusively on myoelectric technology, which prioritizes the needs and infrastructure of developed countries. However, 80% of people with disabilities living in developing countries cannot afford these devices. The main needs of users in developing countries were identified through the I-Corps program, to select the ideal prosthesis type and generate a list of design requirements to improve prosthetic performance. A body-powered hook was developed through a four-stage process: conceptual design, detailed design, design for manufacturing, and manufacturing. The result was the lightweight body-powered hook with a voluntary open mechanism; it weighed 100 g and was manufactured on carbon fiber enriched with nanomaterials to provide hydrophobic and antibacterial properties. Furthermore, this prosthesis contains a novel continuous force regulation system, which allows a constant griping force from 0 to 30 N, providing the user with proprioceptive force to enable accurate and quick-responsive control. Due to its high functionality, robustness and comfort, the upper limb prosthesis developed in this study is an appropriate alternative for most users, regardless of their economic condition or the infrastructure of their country. Full article

Geodetic measurements are commonly used in displacement analysis to determine the absolute values of displacements of points of interest. In order to properly determine the displacement values, it is necessary to correctly identify a subgroup of mutually stable points constituting a reference system. The complexity of this task depends on the spatial size of the network, the timespan of measurements and geological conditions affecting the type of changes in the location of points. As a consequence of the abovementioned factors, the task of stable identification in a longer timespan for a subgroup of points may produce equivocal results. In particular, it is likely that alternative subgroups of reference points meeting the mutual stability criteria will be selected, sometimes without common reference points. The proposed method of reference system identification utilises optimisation algorithms. Two such algorithms were tested, i.e., simulated annealing (SA) and Hooke-Jeeves (HJ) method. Two numerical examples were used to test the proposed method. Although in the first example both methods delivered a positive result, the second example showed the superiority of the SA method over the HJ. The proposed method can be considered a tool supporting the person analysing and making calculations in reaching the ultimate decision on reference points. Full article

In analyzing the woman-centered communal healing ceremony in Toni Cade Bambara’s The Salt Eaters, this article considers how these types of womb-like spaces allow female protagonists to access ancestral and spiritual histories that assist them in navigating physical illnesses and mental health crises. It employs Bell Hooks’ Sisters of the Yam: Black Women and Self-Recovery alongside Arthur Kleinman’s definition of illness as social and transactional to demonstrate that the recognition of illness, and the actualization of wellness, necessitates collective and communal efforts informed by spiritual and cultural modes of knowledge, including alternative healing practices and ancestral mediation. Full article