Impact of Gear Choice on Open Access Fisheries: A Study on Fishery Regimes

The regulation of gears constitutes a fisheries management strategy primarily aimed at preserving immature fish. This approach circumvents the politically sensitive and difficult-to-enforce direct restrictions on entry and catches that characterize many developing contexts. However, existing recommendations often oversimplify socioeconomic dimensions and assume complete government control over gear selection. This oversimplification overlooks crucial effects resulting from the fishers’ agency. To address this gap, our study highlights the implications of fishing gear selection in the outcomes of a fishery. We propose that the choice of fishing gear, i.e., the ability of fishers to select for different fish sizes, has significant direct implications for management due to the distinct fishery regimes it leads to. A swift transition between two states characterizes these regimes: one with high output value and a significant proportion of fishers targeting large fish, and the other with low output value and a predominant number of fishers aiming for small fish. These regimes emerge in response to contextual variables such as prices and economic activity and are not a product of government intervention. Policy management operates on top of these regimes, taking advantage of or hampered by them depending on the context. Our findings are derived from an agent-based model replicating the general conditions on the Nile Perch Fishery in Lake Victoria and accurately simulating its age-structured fish stock. This allows for dynamic shifts driven by gear choices that target different fish sizes

Fully decoupled current control and energy balancing of the Modular Multilevel Matrix Converter

The Modular Multilevel Matrix Converter (M3C) is a Modular Multilevel Converter topology which is suitable for high power low speed drive applications. This paper presents a fully decoupled current control which allows an independent input, output and internal balancing current control. To equalize the energy stored in the nine converter arms, an energy and balancing control is presented which includes average, horizontal, vertical and diagonal balancing control loops. Simulation results are used to verify the function of the M3C together with an induction motor drive system. Additionally, the proper function of the recently constructed arm PCB working as single phase multilevel STATCOM is presented. This PCB will be used for each arm in the laboratory prototype of the M3C in the near future

Overload Capability of the Modular Multilevel Matrix Converter for Feeding High Torque Low Speed Drives

In drive systems, the semiconductors of conventional converters must be dimensioned for the maximum torque. This results in a converter oversizing even for short time overload requirements near standstill, e.g. for mills in the mining industry. In contrast, the Modular Multilevel Matrix Converter (M3C) is characterized by the ability to share the installed switching power between the input and output side. Hence an overload capability up to 200% of the nominal value can be reached at low speeds without additional efforts. This paper explains how the overload capability is used and analyzes the overload torque limits in the whole speed range

Expression pattern of matrix metalloproteinases in human gynecological cancer cell lines

Background: Matrix metalloproteinases (MMPs) are involved in the degradation of protein components of the extracellular matrix and thus play an important role in tumor invasion and metastasis. Their expression is related to the progression of gynecological cancers (e.g. endometrial, cervical or ovarian carcinoma). In this study we investigated the expression pattern of the 23 MMPs, currently known in humans, in different gynecological cancer cell lines. Methods: In total, cell lines from three endometrium carcinomas (Ishikawa, HEC-1-A, AN3 CA), three cervical carcinomas (HeLa, Caski, SiHa), three chorioncarcinomas (JEG, JAR, BeWo), two ovarian cancers (BG-1, OAW-42) and one teratocarcinoma (PA-1) were examined. The expression of MMPs was analyzed by RT-PCR, Western blot and gelatin zymography. Results: We demonstrated that the cell lines examined can constitutively express a wide variety of MMPs on mRNA and protein level. While MMP-2, -11, -14 and -24 were widely expressed, no expression was seen for MMP-12, -16, -20, -25, -26, -27 in any of the cell lines. A broad range of 16 MMPs could be found in the PA1 cells and thus this cell line could be used as a positive control for general MMP experiments. While the three cervical cancer cell lines expressed 10-14 different MMPs, the median expression in endometrial and choriocarcinoma cells was 7 different enzymes. The two investigated ovarian cancer cell lines showed a distinctive difference in the number of expressed MMPs (2 vs. 10). Conclusions: Ishikawa, Caski, OAW-42 and BeWo cell lines could be the best choice for all future experiments on MMP regulation and their role in endometrial, cervical, ovarian or choriocarcinoma development, whereas the teratocarcinoma cell line PA1 could be used as a positive control for general MMP experiments

Anomaly Detections for Manufacturing Systems Based on Sensor Data—Insights into Two Challenging Real-World Production Settings

To build, run, and maintain reliable manufacturing machines, the condition of their components has to be continuously monitored. When following a fine-grained monitoring of these machines, challenges emerge pertaining to the (1) feeding procedure of large amounts of sensor data to downstream processing components and the (2) meaningful analysis of the produced data. Regarding the latter aspect, manifold purposes are addressed by practitioners and researchers. Two analyses of real-world datasets that were generated in production settings are discussed in this paper. More specifically, the analyses had the goals (1) to detect sensor data anomalies for further analyses of a pharma packaging scenario and (2) to predict unfavorable temperature values of a 3D printing machine environment. Based on the results of the analyses, it will be shown that a proper management of machines and their components in industrial manufacturing environments can be efficiently supported by the detection of anomalies. The latter shall help to support the technical evangelists of the production companies more properly

Optimization of the passive components of the Modular Multilevel Matrix Converter for Drive Applications

The Modular Multilevel Matrix Converter (M3C) is a new topology which extends the Modular Multilevel Converter (M2C) family for converters to low speed drive applications. The energy pulsation and therefore the amount of the installed capacitance is very important for the design of such a converter. This paper presents a method to estimate the required amount of capacitance for a given application. Additionally, the design of a newly proposed coupled z-winding arm inductor is explained. It is verified that the use of this inductor allows considerable savings of core and coil material

Novel DC-AC Converter Topology for Multilevel Battery Energy Storage Systems

This paper presents a novel DC-AC converter circuit, especially for the application in multilevel battery energy storage systems (BESS), see fig. 1c. A drawback of the commonly used cascaded H-bridge is that the RMS values of the battery currents can reach multiples of the mean DC battery currents. Additional DC-DC converters in the cells can reduce the AC components of the battery currents, but cause additional semiconductor losses and require large inductors. The circuit presented in this paper reduces these AC contents with less semiconductor losses and smaller inductors than standard DC-DC converters connected to H-bridges

Benefits of Operating Doubly Fed Induction Generators by Modular Multilevel Matrix Converters

The benefits of supplying the rotor circuit of a Doubly Fed Induction Generator (DFIG) by the Modular Multilevel Matrix Converter (M3C) are presented. The M3C allows higher rotor voltages, lower rotor currents and a higher redundancy compared to existing solutions. Filters are dispensable due to the generated multilevel voltages. In case of a line voltage drop the M3C arm voltages can be used to generate temporarily higher rotor voltages which may help to control the rotor currents during faults

Convergent evolution of pregnancy-specific glycoproteins in human and horse

Pregnancy-specific glycoproteins (PSGs) are members of the carcinoembryonic antigen cell adhesion molecule (CEACAM) family that are secreted by trophoblast cells. PSGs may modulate immune, angiogenic and platelet responses during pregnancy. Until now, PSGs are only found in species that have a highly invasive (hemochorial) placentation including humans, mice and rats. Surprisingly, analyzing the CEACAM gene family of the horse, which has a non-invasive epitheliochorial placenta, with the exception of the transient endometrial cups, we identified equine CEACAM family members that seem to be related to PSGs of rodents and primates. We identified seven genes that encode secreted PSG-like CEACAMs. Phylogenetic analyses indicate that they evolved independently from an equine CEACAM1-like ancestor rather than from a common PSG-like ancestor with rodents and primates. Significantly, expression of PSG-like genes (CEACAM44, CEACAM48, CEACAM49 and CEACAM55) was found in non-invasive as well as invasive trophoblast cells such as purified chorionic girdle cells and endometrial cup cells. Chorionic girdle cells are highly invasive trophoblast cells that invade the endometrium of the mare where they form endometrial cups and are in close contact with maternal immune cells. Therefore, the microenvironment of invasive equine trophoblast cells has striking similarities to the microenvironment of trophoblast cells in hemochorial placentas, suggesting that equine PSG-like CEACAMs and rodent and primate PSGs have undergone convergent evolution. This is supported by our finding that equine PSG-like CEACAM49 exhibits similar activity to certain rodent and human PSGs in a functional assay of platelet–fibrinogen binding. Our results have implications for understanding the evolution of PSGs and their functions in maternal–fetal interactions

The Search as Learning Spaceship: Toward a Comprehensive Model of Psychological and Technological Facets of Search as Learning

Using a Web search engine is one of today’s most frequent activities. Exploratory search activities which are carried out in order to gain knowledge are conceptualized and denoted as Search as Learning (SAL). In this paper, we introduce a novel framework model which incorporates the perspective of both psychology and computer science to describe the search as learning process by reviewing recent literature. The main entities of the model are the learner who is surrounded by a specific learning context, the interface that mediates between the learner and the information environment, the information retrieval (IR) backend which manages the processes between the interface and the set of Web resources, that is, the collective Web knowledge represented in resources of different modalities. At first, we provide an overview of the current state of the art with regard to the five main entities of our model, before we outline areas of future research to improve our understanding of search as learning processes