Retroductive Theorizing: A Contribution of Critical Realism to Mixed Methods Research

Mixed methods studies in social sciences are predominantly employed to explore broad, complex, and multifaceted issues and to evaluate policies and interventions. The integration of qualitative and quantitative methods in social sciences most often follows the Peircean pragmatic approach—abductive hypothesis formation followed by deductive and inductive testing/confirmation—with limited theorizing properties. This paper contributes to the field of mixed methods research in social sciences by explicating a two-way interaction process between mixed methods data and [social] theory in a pluralistic inferencing approach espoused by critical realism—retroductive theorizing. The paper further illustrates how through retroductive theorizing, critical realism offers a more epistemologically and ontologically grounded alternative for integrating qualitative and quantitative methods compared to pragmatism.

Cardiovascular disease

This chapter describes the anaesthetic management of the patient with cardiovascular disease. The topics include ischaemic heart disease (including perioperative myocardial infarction and percutaneous coronary intervention), valvular heart disease (incuding prosthetic valves), congenital heart disease, cardiomyopathy, pericardial disease, the patient with a transplanted heart, narrow complex arrhythmias, broad complex arrhythmias and heart block. For each topic, pre-operative investigation and optimisation, treatment, and anaesthetic management are described including peri-operative management of pre-existing arrhythmias (such as atrial fibrillation), and the patient with an implanted pacemaker or defibrillator.

Interesting presentation of a broad complex tachycardia during the head up tilt table test

Broad complex tachycardia (BCT) during head up tilt test (HUTT) is infrequent. Electrophysiology Study (EPS) plays an important part in further differentiation of BCT. We present a case of BCT during HUTT in a patient presenting with presyncope which later on EPS with 3D mapping was diagnosed as ventricular tachycardia. This case highlights the unusual occurrence of BCT during HUTT, the differential diagnosis of BCT and the utility of EPS to reliably identify the type and origin of BCT.

SPOP and CUL3 Modulate the Sonic Hedgehog Signal Response Through Controlled Degradation of GLI Family Transcription Factors

The speckle-type POZ protein (SPOP) functions as a guardian of genome integrity and controls transcriptional regulation by functioning as a substrate adaptor for CUL3/RING-type E3 ubiquitin ligase complexes. SPOP-containing CUL3 complexes target a myriad of DNA-binding proteins involved in DNA repair and gene expression, and as such, are essential modulators of cellular homeostasis. GLI transcription factors are effectors of the Hedgehog (HH) pathway, a key driver of tissue morphogenesis and post-developmental homeostasis that is commonly corrupted in cancer. CUL3-SPOP activity regulates amplitude and duration of HH transcriptional responses by controlling stability of GLI family members. SPOP and GLI co-enrich in phase separated nuclear droplets that are thought to serve as hot spots for CUL3-mediated GLI ubiquitination and degradation. A similar framework exists in Drosophila, in which the Hedgehog-induced MATH (meprin and traf homology) and BTB (bric à brac, tramtrack, broad complex) domain containing protein (HIB) targets the GLI ortholog Cubitus interruptus (Ci) for Cul3-directed proteolysis. Despite this functional conservation, the molecular mechanisms by which HIB and SPOP contribute to Drosophila and vertebrate HH signaling differ. In this mini-review we highlight similarities between the two systems and discuss evolutionary divergence in GLI/Ci targeting that informs our understanding of how the GLI transcriptional code is controlled by SPOP and CUL3 in health and disease.

Drosophila architectural protein CTCF is not essential for fly survival and is able to function independently of CP190

CTCF is the most likely ancestor of proteins that contain large clusters of C2H2 zinc finger domains (C2H2) and is conserved among most bilateral organisms. In mammals, CTCF functions as the main architectural protein involved in the organization of topology-associated domains (TADs). In vertebrates and Drosophila, CTCF is involved in the regulation of homeotic genes. Previously, null mutations in the dCTCF gene were found to result in death during the stage of pharate adults, which failed to eclose from their pupal case. Here, we obtained several new null dCTCF mutations and found that the complete inactivation of dCTCF appears to be limited to phenotypic manifestations of the Abd-B gene and fertility of adult flies. Many modifiers that are not associated with an independent phenotypic manifestation can significantly enhance the expressivity of the null dCTCF mutations, indicating that other architectural proteins are able to functionally compensate for dCTCF inactivation in Drosophila. We also mapped the 715-735 aa region of dCTCF as being essential for the interaction with the BTB (Broad-Complex, Tramtrack, and Bric a brac) and microtubule-targeting (M) domains of the CP190 protein, which binds to many architectural proteins. However, the mutational analysis showed that the interaction with CP190 was not essential for the functional activity of dCTCF in vivo.

Telecommunication Law

Telecommunication law is a broad complex of legal rules, the aim of which is to regulate telecommunication services—the conveyance of signals by means of telecommunication networks; it also covers satellite and space research services. The utmost purpose of these norms is to enable an interference-free transmission of signals, both on a domestic and an international scale. Telecommunication law is composed of three levels of regulations: international, regional, and domestic. The international regulation is performed traditionally by states organized in the International Telecommunication Union on the basis of the ITU Constitution, Convention, and Radio Regulations; trade aspects of telecommunications are regulated by the World Trade Organization. There are several regional cooperation structures dealing with telecommunications; the telecommunication framework of the European Union can serve as an example of a highly harmonized regional regulation based on the Electronic Communication Code. Domestic telecommunication laws are adopted by sovereign states; however, the international rules and regional regulations influence their content and structure. These legal mechanisms are very useful regulatory frameworks that guarantee that telecommunication signals are conveyed to their consumers without administrative and factual obstacles. They have functioned for decades on a pragmatic basis driven mostly by technical and economic needs.

Acute life-threatening hyperkalaemia in a patient with giant hydronephrosis: a case report

A 52-year-old man with a history of urolithiasis presents to the emergency department with a sudden, sharp, continuous right flank colicky pain. Laboratory workup demonstrates acute kidney injury with a mild hyperkalaemia. During the observation period, the patient develops an atypical broad complex sinus bradycardia and eventually short asystolic periods. This was caused by a severe therapy-resistant hyperkalaemia, wherefore emergency haemodialysis was necessary. Radiographic results showed a giant hydronephrosis with a blowout of the right kidney and an obstructing calculi of 21 mm in the distal ureter. We will discuss the mechanism of reversed intraperitoneal dialysis causing the refractory hyperkalaemia and the need of close ECG monitoring in patients where kidney blowout is considered.