Ultrasound tomography enhancement by signal feature extraction with modular machine learning method.

Robust and reliable diagnostic methods are desired in various types of industries. This article presents a novel approach to object detection in industrial or general ultrasound tomography. The key idea is to analyze the time-dependent ultrasonic signal recorded by three independent transducers of an experimental system. It focuses on finding common or related characteristics of these signals using custom-designed deep neural network models. In principle, models use convolution layers to extract common features of signals, which are passed to dense layers responsible for predicting the number of objects or their locations and sizes. Predicting the number and properties of objects are characterized by a high value of the coefficient of determination R2 = 99.8% and R2 = 98.4%, respectively. The proposed solution can result in a reliable and low-cost method of object detection for various industry sectors.

The economic geographies of mergers and acquisitions (M&As).

Mergers and acquisitions (M&As) are on the rise. Interlocking processes of globalization and financialization have increased their attractiveness and incentivized an upward spiral of M&A activity in recent years. This rise is profoundly spatial, as M&As reshape the geographies of production, consumption and finance, while aggravating uneven power-geometries through the concentration of corporate control. Despite this growth and inherent spatiality, economic geography research into M&As has waned. The aim this article is to demonstrate the value of M&As to economic geographers and highlight avenues for future research. This is achieved by explaining how qualitative and quantitative research into the motivations, outcomes and geographies of M&A activity can provide fresh empirical and conceptual insights surrounding wider geographical debates.

Application of Machine Learning Algorithms to the Discretization Problem in Wearable Electrical Tomography Imaging for Bladder Tracking.

The article presents the implementation of artificial intelligence algorithms for the problem of discretization in Electrical Impedance Tomography (EIT) adapted for urinary tract monitoring. The primary objective of discretization is to create a finite element mesh (FEM) classifier that will separate the inclusion elements from the background. In general, the classifier is designed to detect the area of elements belonging to an inclusion revealing the shape of that object. We show the adaptation of supervised learning methods such as logistic regression, decision trees, linear and quadratic discriminant analysis to the problem of tracking the urinary bladder using EIT. Our study focuses on developing and comparing various algorithms for discretization, which perfectly supplement methods for an inverse problem. The innovation of the presented solutions lies in the originally adapted algorithms for EIT allowing for the tracking of the bladder. We claim that a robust measurement solution with sensors and statistical methods can track the placement and shape change of the bladder, leading to effective information about the studied object. This article also shows the developed device, its functions and working principle. The development of such a device and accompanying information technology came about in response to particularly strong market demand for modern technical solutions for urinary tract rehabilitation.

Modified Triple-Tuned Bandpass Filter with Two Concurrently Tuned Transmission Zeros.

In this paper, a modified triple-tuned microstrip bandpass filter is presented. The filter consists of inductively cross-coupled resonators tuned with varactors. The application of the additional source-load couplings together with resonator branch swapping results in two transmission zeros tuned concurrently with operating frequency. These transmission zeros placed on both sides of the passband significantly increase slope steepness in transition bands. The example filter tuned from 0.36 to 0.78 GHz and controlled by a single voltage was manufactured and validated by measurements. It has a constant fractional bandwidth of 11%, low in-band insertion loss ranging from 1.8 to 2.5 dB, and out-of-band attenuation up to 5 GHz without parasitic passbands. The obtained filter parameters made it useful for preselector networks.

Financial information, physical proximity and COVID: The experience of Asian sell-side equity research analysts.

The need for physical proximity and face-to-face communication in financial information flows is contested. But the movement restrictions imposed across Asia during the COVID-19 pandemic, together with the elevated information needs as financial markets became stressed, provided the unique circumstances for a natural experiment to test the extent to which physical interaction is important in the origination and distribution of financial information. Drawing upon 70 interviews undertaken across Asia during 2021, primarily with sell-side analysts who act as information intermediaries in the financial ecosystem, this article provides evidence that physical proximity and face-to-face communication remains highly valued, particularly when accessing information embedded in informal local networks and originated through reciprocal client relationships. Analysts physically restricted from contacts at corporates and within their associated operating environments, reported a degradation of knowledge, especially versus more proximate competitors. The enforced physical separation also weakened previously strong social and reciprocal relationships with clients, even those co-located in the same city. Although these trends may be gradual and incremental rather than dramatic, they are persistent and self-reinforcing, and demonstrate the continued benefits of proximity and face-to-face interaction, with longer-term implications for financial geographies.

Luxembourg and Ireland in global financial networks: Analysing the changing structure of European investment funds.

Using a unique database on investment funds and the conceptual framework of global financial networks, this paper examines the spatial structure of the European investment fund industry, with particular focus on Luxembourg and Ireland. Grounded in financial and economic geography, the paper shows how these countries became the leading investment fund domiciles through a mixture of structural factors and agency enabling a fast and flexible implementation of the European Directive on the Undertakings for the Collective Investment in Transferable Securities (UCITS) of 1985, and the cultivation of the investment fund industry ever since. In the process, Luxembourg and Ireland have built on and developed their functions as offshore jurisdictions and international financial centres, both sustained by their governments and regulatory agencies. The analysis of the functional structure of investment funds and their networked geography reveals the increasingly dominant position of London as the investment management centre for the industry, and the increasing concentration of control by large asset management firms. Stripped to its basics, the geography of European investment fund networks is about large, mainly US, asset management firms, creating and managing funds in Luxembourg and Ireland, and investing money through London. As such, the rise of European investment funds can be seen as an example of European financial integration through Americanisation. The Luxembourg and Irish investment fund industry are connected mainly through London and New York, and thus function as satellites of the NY-LON axis, rather than a Luxembourg-Dublin axis in international finance. Overall, the paper demonstrates that studying this seemingly arcane industry, and the role of two small countries in it, reveals much about the nature of financial globalisation.

Critiquing Construct Validity in World City Network Research: Moving from Office Location Networks to Inter-Organizational Projects in the Modeling of Intercity Business Flows.

The interlocking world city network model and other office location approaches (OLAs) have become the most widely used empirical models of the world city network (WCN). Despite numerous methodological improvements, they continue to rely on a legacy of using data on office locations of firms to indirectly estimate intercity business flows. To advance the dialogue about how to improve on existing empirical models of the WCN, we examine the content, construct and structural validity of OLAs. We analyze the link between the theoretical construct of intercity business flows and network projections obtained from office location data and uncover evidence that calls into question the validity of OLAs as empirical models of the WCN. In the spirit of no deconstruction without reconstruction, we then develop an alternative empirical model of the WCN, based on directly observable relational ties among APS firms, which are formed through co-production of complex services. We call this the inter-organizational project approach (IOPA). We argue for IOPA's construct validity as an empirical model of the WCN and offer empirical evidence for its structural validity. We demonstrate it using a global sample of 161,114 investment bank syndicates in the 2000-2015 period.

On the Design of Dual-Polarised Linear Antenna Arrays with Enhanced Port-to-Port Isolation.

The paper describes the process of designing a dual-polarised linear antenna array with enhanced port-to-port isolation, with the example of a four-element array with isolation better than 60 dB for the U-NII 5.15-5.925 GHz band. As a single antenna, dual-polarised electromagnetically coupled microstrip antennas were used with port-to-port isolation not exceeding 25 dB. A significant improvement in the isolation of the array was achieved thanks to the application of a dedicated feeding network. On the basis of theoretical analysis, a mathematical model describing port-to-port isolation was developed. Circuit and full-wave simulations were carried out to show the influence of electromagnetic couplings between antennas and/or the microstrip lines of the feeding network and the selection of phase shifters/power dividers on the isolation. The fabricated prototype is characterised by a gain of about 14 dBi, polarisation purity of at least -27 dB within the main lobe and close to expectations isolation better than 57 dB within the whole operational band.

COVID-19 and Finance: Market Developments So Far and Potential Impacts on the Financial Sector and Centres.

This paper offers an informed commentary on the actual and potential impacts of the pandemic on financial markets, sector and centres, grounded in literature on financial centres, the state-finance nexus, and trends affecting the landscape of finance since the global financial crisis. We expect a slowdown in new financial regulation, continued firm-level consolidation, and a continued rise of business services related to finance. The application of new financial technologies is likely to accelerate, affecting retail banking in particular, but will not necessarily be led by FinTech firms. Local and regional financial centres are likely to face larger challenges than leading international centres. As the panic and partial recovery in financial markets in March and April 2020 highlighted the significance of the international monetary hierarchy, with the US$ in the lead, a radical shift of financial power to Asia seems unlikely.

High-frequency torsional Alfvén waves as an energy source for coronal heating.

The existence of the Sun's hot atmosphere and the solar wind acceleration continues to be an outstanding problem in solar-astrophysics. Although magnetohydrodynamic (MHD) modes and dissipation of magnetic energy contribute to heating and the mass cycle of the solar atmosphere, yet direct evidence of such processes often generates debate. Ground-based 1-m Swedish Solar Telescope (SST)/CRISP, Hα 6562.8 Å observations reveal, for the first time, the ubiquitous presence of high frequency (~12-42 mHz) torsional motions in thin spicular-type structures in the chromosphere. We detect numerous oscillating flux tubes on 10 June 2014 between 07:17 UT to 08:08 UT in a quiet-Sun field-of-view of 60" × 60" (1" = 725 km). Stringent numerical model shows that these observations resemble torsional Alfvén waves associated with high frequency drivers which contain a huge amount of energy (~105 W m-2) in the chromosphere. Even after partial reflection from the transition region, a significant amount of energy (~103 W m-2) is transferred onto the overlying corona. We find that oscillating tubes serve as substantial sources of Alfvén wave generation that provide sufficient Poynting flux not only to heat the corona but also to originate the supersonic solar wind.

Thyroid dysfunction during severe ovarian hyperstimulation syndrome. A case report.

Thyroid disorders, both in women who wish to conceive and in gravidas, has become a topic of much interest to numerous researchers. Ovarian hyperstimulation syndrome (OHSS) is a potentially life-threatening condition among women undergoing controlled ovarian hyperstimulation (COH). We present a case of thyroid dysfunction in severe OHSS in a patient diagnosed with subclinical hypothyroidism before COH. The dose of L-thyroxine (L-T4) was increased before the procedure in order to reach TSH levels below 2.5 mU/L, and from day 1 of the stimulation the dose of L-T4 was increased by 33%. The patient remained clinically and biochemically euthyroid until day 8 after the embriotransfer (ET). Then, the woman developed severe OHSS, with fluid in the pleural and peritoneal cavity and laboratory evidence of severe OHSS. Laboratory thyroid function tests revealed overt hypothyroidism. L-T4 dose was not increased due to serious clinical condition of the patient. Iodine supplementation was initiated instead. After the symptoms subsided, a period of clinical and laboratory euthyroid state was observed, followed by gestational hyperthyroidism. The L-T4 dose was reduced and iodine supplementation was temporarily ceased. The thyroid function stabilized, while maintaining the L-T4 and iodine supplementation, at 20 weeks of gestation. The patient gave birth by a caesarean section at 37 weeks of gestation and returned to the pre-pregnancy dose of L-T4. To the best of our knowledge, this has been the first report about a patient with thyroid dysfunction in severe OHSS in the Polish literature. On the basis of the presented case and a review of the literature on thyroid dysfunction in women undergoing COH and OHSS, we conclude that clinical signs and biochemical parameters need to be taken into consideration while making therapeutic decision in women with thyroid dysfunction in the course of OHSS. Also, further studies are necessary to elucidate the matter.

[Heterotopic pregnancy after in vitro fertilization]. / Przypadek ciqzy heterotopowej po zaplodnieniu pozaustrojowym.

In our paper we described a rare case of heterotopic pregnancy after in vitro fertilization (IVF-ET). Heterotopic pregnancy (coexistence of intrauterine and ectopic pregnancy) appears in 1 per 30 thousand cases of natural pregnancies and in 1% of pregnancies after IVF. The pregnancy was obtained after ICSI and transfer of 2 embryos. The pregnancy was confirmed by HCG serum presence--13 days after ET. On day 39 after IVF procedure, the patient was admitted to the hospital because of abdominal pain. At admission, ultrasound examination confirmed an 8 week intrauterine pregnancy and enlarged polycystic ovaries. After 3-day-long observation, patient status worsened and laparoscopy procedure was performed. The ectopic pregnancy was confirmed during operation and the ovum was removed a long with fallopian tube. Ultrasound examination on the 6th day after operation confirmed single intrauterine viable fetus. in order to diagnose the possible complications, women undergoing IVF procedure should be carefully observed by IVF performing physicians.

[Twin pregnancy with single fetal death due to triploidy--a case report]. / Ciaza blizniacza z obumarlym wewnatrzmacicznie plodem z triploidia.

The incidence of multiple pregnancies is associated with the increased risk in maternal and fetal complications. Intrauterine death of one twin in the second trimester is a rare obstetric complication. Authors report a case of a twin pregnancy with triploidy of one fetus and no chromosomal anomaly of the other twin in a dichorionic diamniotic twin pregnancy. Amniocentesis at 16th weeks disclosed triploidy of this fetus who died afterwards at 20th week of gestation. The pregnancy was continued with special care of the mother and the alive fetus. The second twin was successfully delivered by cesarean section in the 41st week of pregnancy due to the intrauterine fetal distress.