Development of a synthetic phantom for the selection of optimal scanning parameters in CAD-CT colonography

The aim of this paper is to present the development of a synthetic phantom that can be used for the selection of optimal scanning parameters in computed tomography (CT) colonography. In this paper we attempt to evaluate the influence of the main scanning parameters including slice thickness, reconstruction interval, field of view, table speed and radiation dose on the overall performance of a computer aided detection (CAD)–CTC system. From these parameters the radiation dose received a special attention, as the major problem associated with CTC is the patient exposure to significant levels of ionising radiation. To examine the influence of the scanning parameters we performed 51 CT scans where the spread of scanning parameters was divided into seven different protocols. A large number of experimental tests were performed and the results analysed. The results show that automatic polyp detection is feasible even in cases when the CAD–CTC system was applied to low dose CT data acquired with the following protocol: 13 mAs/rotation with collimation of 1.5 mm × 16 mm, slice thickness of 3.0 mm, reconstruction interval of 1.5 mm, table speed of 30 mm per rotation. The CT phantom data acquired using this protocol was analysed by an automated CAD–CTC system and the experimental results indicate that our system identified all clinically significant polyps (i.e. larger than 5 mm)

Essential versus accessory aspects of cell death: recommendations of the NCCD 2015

Cells exposed to extreme physicochemical or mechanical stimuli die in an uncontrollable manner, as a result of their immediate structural breakdown. Such an unavoidable variant of cellular demise is generally referred to as ‘accidental cell death’ (ACD). In most settings, however, cell death is initiated by a genetically encoded apparatus, correlating with the fact that its course can be altered by pharmacologic or genetic interventions. ‘Regulated cell death’ (RCD) can occur as part of physiologic programs or can be activated once adaptive responses to perturbations of the extracellular or intracellular microenvironment fail. The biochemical phenomena that accompany RCD may be harnessed to classify it into a few subtypes, which often (but not always) exhibit stereotyped morphologic features. Nonetheless, efficiently inhibiting the processes that are commonly thought to cause RCD, such as the activation of executioner caspases in the course of apoptosis, does not exert true cytoprotective effects in the mammalian system, but simply alters the kinetics of cellular demise as it shifts its morphologic and biochemical correlates. Conversely, bona fide cytoprotection can be achieved by inhibiting the transduction of lethal signals in the early phases of the process, when adaptive responses are still operational. Thus, the mechanisms that truly execute RCD may be less understood, less inhibitable and perhaps more homogeneous than previously thought. Here, the Nomenclature Committee on Cell Death formulates a set of recommendations to help scientists and researchers to discriminate between essential and accessory aspects of cell death

A hydraulically driven colonoscope

BACKGROUND: Conventional colonoscopy requires a high degree of operator skill and is often painful for the patient. We present a preliminary feasibility study of an alternative approach where a self-propelled colonoscope is hydraulically driven through the colon. METHODS: A hydraulic colonoscope which could be controlled manually or automatically was developed and assessed in a test bed modelled on the anatomy of the human colon. A conventional colonoscope was used by an experienced colonoscopist in the same test bed for comparison. Pressures and forces on the colon were measured during the test. RESULTS: The hydraulic colonoscope was able to successfully advance through the test bed in a comparable time to the conventional colonoscope. The hydraulic colonoscope reduces measured loads on artificial mesenteries, but increases intraluminal pressure compared to the colonoscope. Both manual and automatically controlled modes were able to successfully advance the hydraulic colonoscope through the colon. However, the automatic controller mode required lower pressures than manual control, but took longer to reach the caecum. CONCLUSIONS: The hydraulic colonoscope appears to be a viable device for further development as forces and pressures observed during use are comparable to those used in current clinical practice

A systematic review evaluating the psychometric properties of measures of social inclusion

Introduction: Improving social inclusion opportunities for population health has been identified as a priority area for international policy. There is a need to comprehensively examine and evaluate the quality of psychometric properties of measures of social inclusion that are used to guide social policy and outcomes. Objective: To conduct a systematic review of the literature on all current measures of social inclusion for any population group, to evaluate the quality of the psychometric properties of identified measures, and to evaluate if they capture the construct of social inclusion. Methods: A systematic search was performed using five electronic databases: CINAHL, PsycINFO, Embase, ERIC and Pubmed and grey literature were sourced to identify measures of social inclusion. The psychometric properties of the social inclusion measures were evaluated against the COSMIN taxonomy of measurement properties using pre-set psychometric criteria. Results: Of the 109 measures identified, twenty-five measures, involving twenty-five studies and one manual met the inclusion criteria. The overall quality of the reviewed measures was variable, with the Social and Community Opportunities Profile-Short, Social Connectedness Scale and the Social Inclusion Scale demonstrating the strongest evidence for sound psychometric quality. The most common domain included in the measures was connectedness (21), followed by participation (19); the domain of citizenship was covered by the least number of measures (10). No single instrument measured all aspects within the three domains of social inclusion. Of the measures with sound psychometric evidence, the Social and Community Opportunities Profile-Short captured the construct of social inclusion best. Conclusions: The overall quality of the psychometric properties demonstrate that the current suite of available instruments for the measurement of social inclusion are promising but need further refinement. There is a need for a universal working definition of social inclusion as an overarching construct for ongoing research in the area of the psychometric properties of social inclusion instruments

Molecular mechanisms of cell death: recommendations of the Nomenclature Committee on Cell Death 2018.

Over the past decade, the Nomenclature Committee on Cell Death (NCCD) has formulated guidelines for the definition and interpretation of cell death from morphological, biochemical, and functional perspectives. Since the field continues to expand and novel mechanisms that orchestrate multiple cell death pathways are unveiled, we propose an updated classification of cell death subroutines focusing on mechanistic and essential (as opposed to correlative and dispensable) aspects of the process. As we provide molecularly oriented definitions of terms including intrinsic apoptosis, extrinsic apoptosis, mitochondrial permeability transition (MPT)-driven necrosis, necroptosis, ferroptosis, pyroptosis, parthanatos, entotic cell death, NETotic cell death, lysosome-dependent cell death, autophagy-dependent cell death, immunogenic cell death, cellular senescence, and mitotic catastrophe, we discuss the utility of neologisms that refer to highly specialized instances of these processes. The mission of the NCCD is to provide a widely accepted nomenclature on cell death in support of the continued development of the field

Business models innovation in investment banks: A resilience perspective

© 2020, The Author(s). Firms frequently change their business models in order to respond to internal and external challenges. This study aims to explore how investments banks adjust their business models in response to internal and external challenges. Based on a qualitative data from ten major investment banks operating in the largest financial market in the Middle East, we show that investment banks can achieve resilience by adjusting their business models through continuous activity changes in response to internal and external challenges. Specifically, investment banks adjust their business models through deploying alternative combinations of activities from a broad repertoire of activities. Within the same bank, divisions that respond to external challenges tend to sustain their performance, whereas resilient divisions that respond to both internal and external challenges tend to bounce back or achieve substantial increase in performance levels. This study contributes to the literature by proposing resilience as an alternative approach to business model innovation and by providing insight into how firms adjust their business models by altering specific activities in response to both internal and external challenges

Influence of macroporous gold support and its functionalization on lactate oxidase-based biosensors response

A general bioanalytical platform for biosensor applications was developed based on three-dimensional ordered macroporous (3DOM) gold film modified electrodes using lactate oxidase (LOx) as a case study, within the framework of developing approaches of broad applicability. The electrode was electrochemically fabricated with an inverted opal template, making the surface area of the 3DOM gold electrode up to 18 times higher than that of bare flat gold electrodes. These new electrochemical transducers were characterized by using Field Emission Scanning Electron Microscopy (FE-SEM), Atomic Force Microscopy (AFM) and the X-ray diffraction (XRD). The biosensor was developed by immobilization of lactate oxidase (LOx), on a 3DOM gold electrode modified with a self-assembled monolayer of dithiobis-N-succinimidyl propionate (DTSP). The resulting lactate oxidase biosensor was characterized by electrochemical impedance spectroscopy (EIS). The 3DOM gold electrode not only provides a good biocompatible microenvironment but also promotes the increase of conductivity and stability. Thus, the developed lactate oxidase bioanalytical platforms showed higher mediated bioelectrocatalytic activity compared to others previously described based on polycrystalline gold transducers. The response to varying lactate concentrations has been obtained in the presence of hydroxymethylferrocene as redox mediator in solution. Under these conditions, the bioanalytical platform response for DTSP covalently bound enzyme was improved with respect to that obtained in absence of DTS

Direct Electrochemistry and Environmental Sensing of Rice Hemoglobin Immobilized at Graphite Electrodes

Non-symbiotic hemoglobin from rice (Oryza sativa L.), OsHb-1, with its rather hexacoordinated than pentacoordinated heme and high affinity for oxygen, may have a particular role in O2 and environmental sensing. Here, the 21 kDa monomeric OsHb-1 was electrochemically studied at graphite electrodes and further probed in analysis of environmental species such as hydrogen peroxide, cyanide, and superoxide. Redox potential of the OsHb-1 heme iron was found to be -136 mV vs. SCE, at pH 6.5, while the rate constant ks for the heterogeneous electron transfer (ET) between graphite and OsHb-1 immobilised in the Nafion membrane at the carbon nanotubes-modified electrodes was below 0.2 s-1. Despite sluggish ET, OsHb-1 efficiently, with current densities exceeding 2 mA cm-2 at ¿0.3 V, electrocatalyzed reduction of O2 starting from the potentials of OsHb-1¿s heme. The bioelectrocatalytic reduction of O2 was inhibited by CN- thus enabling its sensitive, 100 pM analysis. Peroxidase-like activity of OsHb-1 and the reaction of superoxide anion with the heme iron of OsHb-1, in de-oxygenated solutions, were studied and analysed in terms of OsHb-1 reactivity. The results obtained indicate OsHb-1 is a sensitive tool for environmental biosensing and toxicity screeningThe work was supported by the Danish Council for Independent Research, Natural Sciences (FNU), Project Number 11-107176, and by the Spanish Ministry of Economy and Competitiveness (Grant No. AGL2010-16167).Peer Reviewe

Harmonizing Diversity: Tuning Anthropological Research to Complexity

The contributions in this issue of Social Science Computer Review represent a range of computational approaches to theoretical and disciplinary specializations in anthropology that reflect on and expand the future orientation and practice of the formal and comparative agenda in the context of an increasing emphasis on complexity in anthropology as a discipline. Themes covered in this issue include kinship, funerary burials, urban legends, eye tracking and looking at mode influences on online data collection. A common theme throughout the papers is examining the relationship between global emergent processes and structures and the local individual contributions to this emergence, and how the local and global contexts influence each other. We argue that unless complexity is addressed more overtly by leveraging computational approaches to data collection, analysis and theory building, anthropology and social science more generally face an existential challenge if they are to continue to pursue extended field research exercise, intersubjective productions, deep personal involvement, interaction with materiality and engagement with people whilst generating research outcomes of relevance to the world beyond the narrow confines of specialist journals and conferences