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Evidence for intermittent coupling of intramyocardial small, engineered heart tissues acutely implanted into rabbit myocardium
Get PDFAims:
Electrical integration of human-induced pluripotent stem-cell-derived cardiomyocyte (hiPSC-CM)-based tissue with the host myocardium is a requirement of successful regeneration therapy. This study was designed to identify electrical coupling in the acute phase (1–2 h) post-grafting using an ex vivo model.
Methods and results:
Small, engineered heart tissues (mini-EHTs), consisting of ∼50 000 hiPSC-CMs on a hydrogel (spontaneous rate 0.34 ± 0.05 Hz), were loaded with Cal520-AM. EHTs were implanted sub-epicardially into a Langendorff-perfused rabbit heart after blebbistatin treatment. For up to 100 min, a continuous pseudo-electrocardiogram was recorded during sinus rhythm (rate 2.0–3.5 Hz). At 25 min intervals, EHT calcium transients (CaTs) were recorded for 10–20 s (no contraction group). To study the influence of mechanical activity, blebbistatin was washed off after implantation (contraction recovery group). Periodic entrainment of EHTs with the myocardium was detected less often (P = 0.011) in the no contraction group (1/9 hearts) than in the contraction recovery group (5/6 hearts). The average coupling delay (QRS-CaT) and the difference in consecutive delays (Δdelay) were 89 ± 50 and 10 ± 3 ms, respectively (n = 12 traces; N = 6 hearts). Coupling ratios (QRS:CaT) varied from 2:1 to 4:1. These coupling parameters were not significantly different in the two experimental groups. Modelling of hiPSC-CM tissue separated by a 25 μm saline gap from the myocardium demonstrated field-effect coupling with similarly variable activation delays. Importantly, coupling failed with a gap of 100 μm.
Conclusion:
EHT entrainment is possible immediately after grafting and has features compatible with field-effect coupling. Sensitivity to the gap dimensions may explain why entrainment is more common in actively contracting myocardium
Marketing of unhealthy brands during the 2018 Fédération Internationale de Football Association (FIFA) World Cup UK broadcasts – a frequency analysis
No full textNo abstract available
Measurement of the CKM angle γ in B± → DK*(892)± decays
Get PDFMeasurements of CP observables and the CKM angle γ are performed in
B± → DK∗
(892)± decays, where D represents a superposition of D0 and D¯0
states, using the LHCb dataset collected during Run 1 (2011–2012) and Run 2 (2015–2018). A
study of this channel is presented with the D meson reconstructed in two-body final states
K±π
∓, K+K− and π
+π
−; four-body final states K±π
∓π
±π
∓ and π
+π
−π
+π
−; and three-body final states K0
S
π
+π
− and K0
SK+K−. This analysis includes the first observation of
the suppressed B± → [π
±K∓]DK∗± and B± → [π
±K∓π
±π
∓]DK∗± decays. The combined
result gives γ = (63 ± 13)◦
Integration of global lipidomics and gonad histological analysis via multivariate chemometrics and machine learning: identification of potential lipid markers of ovarian development in the blue mussel (Mytilus edulis)
Get PDFBackground/Objectives: Gonad histological analysis (GHA) is the traditional method for assessing the gonad maturation status of blue mussels (Mytilus edulis). GHA has some operational disadvantages, such as limited processing outputs, subjectivity in the assessment of transitional stages of gonadal maturation and the need for experienced and trained operators. Lipids could become important indicators of gonadal maturation as they cover many essential functions during such processes in mussels. In this work, blue mussel ovary (BMO) ultrastructure is integrated with liquid chromatography coupled with mass spectrometry (LC-MS) lipidomics fingerprinting to identify suitable markers for ovarian maturation through the application of chemometrics and machine learning approaches. Methods: BMOs are classified here as ripe or non-ripe by means of GHA and the gamete volume fraction (GVF). Receiving operating characteristic (ROC) curves were used to classify the results of the different statistics according to their area under the curve (AUC), and the functional role of important lipids was assessed by lipid ontology enrichment (LiOn) analysis. Results: This approach allowed for the selection of a panel of 35 lipid molecules (AUC > 0.8) that can distinguish non-ripe from ripe BMOs. Ceramide phosphoethanolamine (CerPE) 40:2 was the molecule with the highest classification ability (AUC 0.905), whereas glycerophosphoserine (PS) was the class mostly changing between the two groups. LiOn analysis indicated significant differences in the functional roles of these lipids, highlighting enrichment terms associated with membrane lipids, lysosomes and highly unsaturated triglycerides (TGs) in non-ripe ovaries, whereas terms associated with storage lipids and low-saturated TG characterised ripe BMOs
Climate Change Reporting: What Do We Know About Its Determinants and Capital Market Consequences?
Get PDFDecoloniality and nonviolence as a pedagogy of hope: Chilean pre-service teachers and their reconceptualisation of inclusive classrooms
Get PDFThis chapter explores how Chilean teachers’ initial assumptions about inclusiveness were shaped by narratives from the Global North that narrowly framed inclusiveness as a method addressing disability or specific learning needs. Their concepts of violence and nonviolence were similarly limited, focusing only on direct violence and pacifism, respectively, without recognising structural and cultural dimensions. Through regular engagement with decolonial perspectives on nonviolence, participants experienced a paradigm shift, coming to understand nonviolence as an active, relational practice that fosters empathy, community, and collaboration. This shift inspired new hope and optimism, positioning nonviolence as a sustainable, human-centred path to inclusiveness that emphasises shared human experiences over socially constructed identity differences
A systematic review of the use of human body donor models for postgraduate laparoscopic surgical training
Get PDFWhile laparoscopy has become the gold standard for many abdominal surgical procedures, it has a steeper learning curve compared to an open surgical approach. Body donor (cadaveric) models (BDM) present a high-fidelity model for laparoscopic surgical training. There are a variety of models available from fresh-frozen models to soft-embalmed models using multiple proprietary preparation solutions. There remains uncertainty surrounding the models’ relative strengths and weaknesses. This study aims to evaluate the different body donor models used in postgraduate laparoscopic surgical training. A systematic search was conducted across Medline, Embase, ClinicalTrials.gov, and Cochrane to identify articles relevant to postgraduate laparoscopic training using HBD following the PRISMA guidelines. A narrative review themed on HBD feasibility, validity, and educational utility in laparoscopic surgical training. PROSPERO Registration: NIHR CRD42023437230. Fifty-five studies were included. BDM in general were perceived as authentic and of high educational value. Soft embalmed models (e.g., Thiel®, Genelyn®, modified Larssen®), were reported to be feasible and possess high face validity despite embalming and had advantages over fresh frozen body donors (FFBDs), including reusability, cost-effectiveness, and better odor satisfaction. Comparative studies reported a preference of human body donor models over other simulation methods due to its high fidelity. Body donor models including soft embalmed models provide high-fidelity laparoscopic training environments well perceived by trainees regardless of preservation or tissue fixation. Significant research gaps remain; head-to-head comparative studies between the different models remain sparse as well as data on non-educational aspects such as formal cost-utility analysis and ecological impact
Pedestals or portals? Representations of museums and museum learning in and through children's literature
No full textThis chapter explores how museums and museum learning are represented in and through children's literature, past and present, with a view to considering how such texts can reflect, extend and, perhaps, distort current ways of being and doing at the forefront of museum education. We begin by highlighting some key tensions within the field of museum education, such as perceived and felt barriers to museum engagement for children and families (and also including carers and educators) that can lead to an “Othering” of the museum experience, and diverging views on “what counts” as cultural or museum learning. We provide an introductory overview to texts for children that positions them as complex, ideological tools that can project the hopes, beliefs and values of the adults who, after all, write them for children. We also consider the potential of children's texts about museums to function as mirrors, windows and doors: as mirrors (Bishop, 1990), by reflecting (or not) aspects of their lives; as windows, by providing a way to glimpse into new worlds; and as doorways, by offering portals into new worlds and different cultures. We then explore a range of children's texts that feature representations of museums, as well as examples of how characters are shown to behave, interact and respond when in museums. Through our analysis, we will ask who is seen visiting and exploring museums in such texts. Who are museums shown to be for? What role do the child characters play in these books? Taking a broadly chronological approach, we consider how pedagogic approaches in museum education can be traced in and through children's literature, moving from the idea of museums as “quintessentially adult places” where adult language and adult authority prevail (Butler, 2006: 50) towards more inclusive, active, child-centred spaces that seek to prioritise and celebrate aspects of everyday and “ordinary” culture (Williams, 1958/2014. We extend the analysis to incorporate examples of children's texts produced by museums and heritage organisations in association with their collections and we consider the ways that museums represent themselves in the texts they have commissioned for children and families. In this way, we position texts for children as representations of possibility within museums, and consider how they may induct younger readers into particular ways of engaging with museums, as well as the significance of this
Investigation of Coxiella burnetii distribution in a Scottish dairy cattle herd with history of stillbirths
Get PDFBackground: Coxiella burnetii is a bacterial pathogen that can cause abortion and reproductive disease in livestock. In the UK, C. burnetii affects many
dairy cattle herds, although the infection dynamics are poorly understood.
Our study was performed to investigate infection patterns within a dairy cattle herd in Scotland that had experienced stillbirths attributed to C. burnetii
infection.
Methods: Different management groups within the affected herd were
sampled. Serology and qPCR testing of vaginal swabs were performed to
investigate infection status. Regression analyses were performed to evaluate associations between diagnostic results and variables describing calving
status and farm site.
Results: C. burnetii infection was detected in all management groups within
the herd. The highest seroprevalence was detected in pre-calving heifers
(78.6%) and the highest bacterial loads were detected in post-calving animals.
Limitations: These data represent a sample from one farm and testing for
a single pathogen shedding route, which limits the generalizability of our
findings.
Conclusions: C. burnetii infection is widespread within this affected herd.
Marked differences were observed between the management groups, which
may be explained by variables including pregnancy stage or environmental
factors. Further work is needed to understand the implications of these results
for the wider UK dairy sector
Erysipelothrix in Cook Inlet, Alaska, USA: an emerging bacterial pathogen of the endangered Cook Inlet beluga whale
Get PDFErysipelothrix is a genus of opportunistic bacteria of humans and animals. In 2019, a marked increase in infections by the zoonotic bacterium Erysipelothrix in Cook Inlet (Alaska, USA) beluga whales Delphinapterus leucas (CIBs) was detected through routine surveillance. A retrospective study was performed using archival records from 1998 to the present; archived samples from 2006 to the present; colleague interviews; and a literature review. Erysipelothrix was detected in 18 of 63 (28.6%) CIBs necropsied between 2006 and 2023, and when present after 2017, it was the primary cause of death. Erysipelothrix was rarely detected in other species of wildlife, domestic animals or in the environment in and around Cook Inlet during the same period. Sequencing of isolates demonstrated several different lineages, negating the possibility of infection from a common source or single strain. The lack of documented previous occurrence of Erysipelothrix in or near Cook Inlet indicates that this is likely an emerging phenomenon
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