Synapse-type-specific competitive Hebbian learning forms functional recurrent networks.

Cortical networks exhibit complex stimulus-response patterns that are based on specific recurrent interactions between neurons. For example, the balance between excitatory and inhibitory currents has been identified as a central component of cortical computations. However, it remains unclear how the required synaptic connectivity can emerge in developing circuits where synapses between excitatory and inhibitory neurons are simultaneously plastic. Using theory and modeling, we propose that a wide range of cortical response properties can arise from a single plasticity paradigm that acts simultaneously at all excitatory and inhibitory connections-Hebbian learning that is stabilized by the synapse-type-specific competition for a limited supply of synaptic resources. In plastic recurrent circuits, this competition enables the formation and decorrelation of inhibition-balanced receptive fields. Networks develop an assembly structure with stronger synaptic connections between similarly tuned excitatory and inhibitory neurons and exhibit response normalization and orientation-specific center-surround suppression, reflecting the stimulus statistics during training. These results demonstrate how neurons can self-organize into functional networks and suggest an essential role for synapse-type-specific competitive learning in the development of cortical circuits.

Intraoperative complications of robotic-assisted extended totally extraperitoneal (eTEP) ventral hernia retromuscular repairs with mesh: a systematic literature review and narrative synthesis.

Minimally invasive extended totally extraperitoneal (eTEP) technique is revolutionising ventral hernia repairs. Robotic-assisted eTEP has been gaining popularity due to better visual clarity and greater dexterity provided by the robotic systems, compared to laparoscopy. Despite growing number of papers being published each year, so far, no study has explored intraoperative complications in robotic-assisted eTEP. The aim was to perform a systematic literature review on the incidence of intraoperative complications in robotic-assisted eTEP ventral hernia repairs. The study protocol was preregistered with PROSPERO, registration number CRD42023450072. Twelve categories of intraoperative complications were defined by the authors. A search of PubMed and Embase was conducted on 16/08/2023, for articles pertaining to robotic-assisted eTEP operations in ventral hernias in adults. Articles were critically appraised and data were extracted using predefined extraction templates. No data were suitable for statistical analysis and a narrative synthesis was performed instead. Ten studies fulfilled the inclusion criteria, of which four studies reported intraoperative complications. Of the 12 categories of intraoperative complications, only 5 were reported. Three studies encountered adherent bowel inside the hernia sac. One reported linea alba injury with subsequent anterior layer dehiscence. There was one case of unrecognised intraoperative retromuscular bleeding and one case of insufflation injury with subcutaneous emphysema. There is a paucity of literature on the incidence of intraoperative complications in robotic-assisted eTEP ventral hernia repairs. Available studies suggest complication rates are low. More robust studies using prospective data from hernia registries are required before further conclusions can be drawn.

Texture and Color Enhancement Imaging Improves Colonic Adenoma Detection: A Multicenter Randomized Controlled Trial.

The global burden of colorectal cancer is expected to increase more than 60% by 2030; however, compelling evidence now shows that the implementation of population screening programs in developed countries has led to a substantial reduction in incidence and mortality.1,2 Despite this, patients continue to develop preventable colorectal cancers, in part because of high rates of interval colon cancer diagnosed after screening or surveillance colonoscopies.3.

The UCLA Cosmochemistry Database.

The UCLA Cosmochemistry Database was initiated as part of a data-rescue and -storage project aimed at archiving a variety of cosmochemical data acquired at University of California, Los Angeles (UCLA). The data collection includes elemental compositions of extraterrestrial materials analyzed by UCLA cosmochemists over the last five decades. The analytical techniques include atomic absorption spectrometry (AAS) and neutron activation analysis (NAA) at UCLA. The data collection is stored on the Astromaterials Data System (Astromat). We provide both interactive tables and downloadable datasheets for users to access all data. The UCLA Cosmochemistry Database archives cosmochemical data that are essential tools for increasing our understanding of the nature and origin of extraterrestrial materials. Future studies can reference the data collection in the examination, analysis, and classification of newly acquired extraterrestrial samples.

The Role of Artificial Intelligence in Colorectal Cancer Screening: Lesion Detection and Lesion Characterization.

Colorectal cancer remains a leading cause of cancer-related morbidity and mortality worldwide, despite the widespread uptake of population surveillance strategies. This is in part due to the persistent development of 'interval colorectal cancers', where patients develop colorectal cancer despite appropriate surveillance intervals, implying pre-malignant polyps were not resected at a prior colonoscopy. Multiple techniques have been developed to improve the sensitivity and accuracy of lesion detection and characterisation in an effort to improve the efficacy of colorectal cancer screening, thereby reducing the incidence of interval colorectal cancers. This article presents a comprehensive review of the transformative role of artificial intelligence (AI), which has recently emerged as one such solution for improving the quality of screening and surveillance colonoscopy. Firstly, AI-driven algorithms demonstrate remarkable potential in addressing the challenge of overlooked polyps, particularly polyp subtypes infamous for escaping human detection because of their inconspicuous appearance. Secondly, AI empowers gastroenterologists without exhaustive training in advanced mucosal imaging to characterise polyps with accuracy similar to that of expert interventionalists, reducing the dependence on pathologic evaluation and guiding appropriate resection techniques or referrals for more complex resections. AI in colonoscopy holds the potential to advance the detection and characterisation of polyps, addressing current limitations and improving patient outcomes. The integration of AI technologies into routine colonoscopy represents a promising step towards more effective colorectal cancer screening and prevention.

Igneous meteorites suggest Aluminium-26 heterogeneity in the early Solar Nebula.

The short-lived radionuclide aluminium-26 (26Al) isotope is a major heat source for early planetary melting. The aluminium-26 - magnesium-26 (26Al-26Mg) decay system also serves as a high-resolution relative chronometer. In both cases, however, it is critical to establish whether 26Al was homogeneously or heterogeneously distributed throughout the solar nebula. Here we report a precise lead-207 - lead-206 (207Pb-206Pb) isotopic age of 4565.56 ± 0.12 million years (Ma) for the andesitic achondrite Erg Chech 002. Our analysis, in conjunction with published 26Al-26Mg data, reveals that the initial 26Al/27Al in the source material of this achondrite was notably higher than in various other well-preserved and precisely dated achondrites. Here we demonstrate that the current data clearly indicate spatial heterogeneity of 26Al by a factor of 3-4 in the precursor molecular cloud or the protoplanetary disk of the Solar System, likely associated with the late infall of stellar materials with freshly synthesized radionuclides.

Well-hidden methanogenesis in deep, organic-rich sediments of Guaymas Basin.

Deep marine sediments (>1mbsf) harbor ~26% of microbial biomass and are the largest reservoir of methane on Earth. Yet, the deep subsurface biosphere and controls on its contribution to methane production remain underexplored. Here, we use a multidisciplinary approach to examine methanogenesis in sediments (down to 295 mbsf) from sites with varying degrees of thermal alteration (none, past, current) at Guaymas Basin (Gulf of California) for the first time. Traditional (13C/12C and D/H) and multiply substituted (13CH3D and 12CH2D2) methane isotope measurements reveal significant proportions of microbial methane at all sites, with the largest signal at the site with past alteration. With depth, relative microbial methane decreases at differing rates between sites. Gibbs energy calculations confirm methanogenesis is exergonic in Guaymas sediments, with methylotrophic pathways consistently yielding more energy than the canonical hydrogenotrophic and acetoclastic pathways. Yet, metagenomic sequencing and cultivation attempts indicate that methanogens are present in low abundance. We find only one methyl-coenzyme M (mcrA) sequence within the entire sequencing dataset. Also, we identify a wide diversity of methyltransferases (mtaB, mttB), but only a few sequences phylogenetically cluster with methylotrophic methanogens. Our results suggest that the microbial methane in the Guaymas subsurface was produced over geologic time by relatively small methanogen populations, which have been variably influenced by thermal sediment alteration. Higher resolution metagenomic sampling may clarify the modern methanogen community. This study highlights the importance of using a multidisciplinary approach to capture microbial influences in dynamic, deep subsurface settings like Guaymas Basin.

Significance of intra-operative cholangiogram and its application in suspected duodenal injuries - Case report.

INTRODUCTION AND IMPORTANCE: Intraoperative cholangiogram has always been a critical procedure that allows identification of biliary anatomy, thereby reducing the risks of bile duct injuries. CASE PRESENTATION: We present a unique case where the intraoperative cholangiogram highlighted a suspected duodenal injury. CLINICAL DISCUSSION: This case discusses the intraoperative steps taken to ensure there was no injury, highlight the importance of cholangiogram interpretation as a skill for all surgeons. CONCLUSION: Intraoperative cholangiogram is a crucial procedure to highlight both biliary and non-biliary anatomy and can be used to identify duodenal injuries as was assessed in our case.

Earth shaped by primordial H2 atmospheres.

Earth's water, intrinsic oxidation state and metal core density are fundamental chemical features of our planet. Studies of exoplanets provide a useful context for elucidating the source of these chemical traits. Planet formation and evolution models demonstrate that rocky exoplanets commonly formed with hydrogen-rich envelopes that were lost over time1. These findings suggest that Earth may also have formed from bodies with hydrogen-rich primary atmospheres. Here we use a self-consistent thermodynamic model to show that Earth's water, core density and overall oxidation state can all be sourced to equilibrium between hydrogen-rich primary atmospheres and underlying magma oceans in its progenitor planetary embryos. Water is produced from dry starting materials resembling enstatite chondrites as oxygen from magma oceans reacts with hydrogen. Hydrogen derived from the atmosphere enters the magma ocean and eventually the metal core at equilibrium, causing metal density deficits matching that of Earth. Oxidation of the silicate rocks from solar-like to Earth-like oxygen fugacities also ensues as silicon, along with hydrogen and oxygen, alloys with iron in the cores. Reaction with hydrogen atmospheres and metal-silicate equilibrium thus provides a simple explanation for fundamental features of Earth's geochemistry that is consistent with rocky planet formation across the Galaxy.

SLAC microresonator RF (SMuRF) electronics: A tone-tracking readout system for superconducting microwave resonator arrays.

We describe the newest generation of the SLAC Microresonator RF (SMuRF) electronics, a warm digital control and readout system for microwave-frequency resonator-based cryogenic detector and multiplexer systems, such as microwave superconducting quantum interference device multiplexers (µmux) or microwave kinetic inductance detectors. Ultra-sensitive measurements in particle physics and astronomy increasingly rely on large arrays of cryogenic sensors, which in turn necessitate highly multiplexed readout and accompanying room-temperature electronics. Microwave-frequency resonators are a popular tool for cryogenic multiplexing, with the potential to multiplex thousands of detector channels on one readout line. The SMuRF system provides the capability for reading out up to 3328 channels across a 4-8 GHz bandwidth. Notably, the SMuRF system is unique in its implementation of a closed-loop tone-tracking algorithm that minimizes RF power transmitted to the cold amplifier, substantially relaxing system linearity requirements and effective noise from intermodulation products. Here, we present a description of the hardware, firmware, and software systems of the SMuRF electronics, comparing achieved performance with science-driven design requirements. In particular, we focus on the case of large-channel-count, low-bandwidth applications, but the system has been easily reconfigured for high-bandwidth applications. The system described here has been successfully deployed in lab settings and field sites around the world and is baselined for use on upcoming large-scale observatories.

Anti-tumour necrosis factor-induced skin rashes in inflammatory bowel disease: a systematic review and evidence-based management algorithm.

BACKGROUND: Anti-tumour necrosis factor alpha (anti-TNF) agents are a highly effective treatment for inflammatory bowel disease (IBD). Skin lesions, including psoriasiform, eczematous and lupoid eruptions, may paradoxically result from anti-TNF use and cause significant morbidity leading to discontinuation of therapy. There are no consensus guidelines on the management of these lesions. AIMS: This systematic review considers the existing evidence regarding cutaneous complications of anti-TNF therapy in IBD and the development of an algorithm for management. METHODS: A systematic review was performed by searching Medline (Pubmed) and Embase for articles published from inception to January 2021. The following search terms were used 'anti-tumour necrosis factor alpha', 'infliximab', 'adalimumab', 'certolizumab', 'golimumab', 'inflammatory bowel disease', 'Crohn disease', 'Ulcerative colitis', 'psoriasis', 'psoriasiform', 'dermatitis', 'lupus', 'skin lesion' and 'skin rash'. Reference lists of relevant studies were reviewed to identify additional suitable studies. RESULTS: Thirty-four studies were included in the review. Eczema can generally be managed with topical agents and the anti-TNF can be continued, while the development of lupus requires immediate cessation of the anti-TNF and consideration of alternative immunomodulators. Management of psoriasis and psoriasiform lesions may follow a step-wise algorithm where topical treatments will be trialled in less severe cases, with recourse to an alternative anti-TNF or a switch to an alternative class of biological agent. CONCLUSION: Assessment of anti-TNF skin lesions should be performed in conjunction with a dermatologist and rheumatologist in complex cases. High-quality prospective studies are needed to clarify the validity of these algorithms in the future.

Samples returned from the asteroid Ryugu are similar to Ivuna-type carbonaceous meteorites.

Carbonaceous meteorites are thought to be fragments of C-type (carbonaceous) asteroids. Samples of the C-type asteroid (162173) Ryugu were retrieved by the Hayabusa2 spacecraft. We measured the mineralogy and bulk chemical and isotopic compositions of Ryugu samples. The samples are mainly composed of materials similar to those of carbonaceous chondrite meteorites, particularly the CI (Ivuna-type) group. The samples consist predominantly of minerals formed in aqueous fluid on a parent planetesimal. The primary minerals were altered by fluids at a temperature of 37° ± 10°C, about [Formula: see text] million (statistical) or [Formula: see text] million (systematic) years after the formation of the first solids in the Solar System. After aqueous alteration, the Ryugu samples were likely never heated above ~100°C. The samples have a chemical composition that more closely resembles that of the Sun's photosphere than other natural samples do.

Poor engagement and adherence predict neoplasia in inflammatory bowel disease: a case-control study.

BACKGROUND: Colorectal adenocarcinoma is an important and preventable complication of inflammatory bowel disease (IBD). A previous case series suggested mental health issues and poor engagement in care as novel risk factors. AIMS: To confirm the role of patient engagement in care in the development of neoplasia using a case-control methodology. METHODS: Patients in a single referral centre from 2007 to 2017 with colorectal adenocarcinoma, high-grade dysplasia or multifocal low-grade dysplasia were included as neoplasia cases. Each case was assigned up to three matched controls (matched for age, gender, underlying disease, IBD type and phenotype and disease duration). Novel and known risk factors were compared between groups. RESULTS: Thirty-two cases with 88 matched controls were included. Patients with neoplasia were more likely to have poor adherence to, or engagement with, care (odds ratio (OR) 4.79). They were also more likely to have chronic use of opioids (OR 3.86) and long-term prednisolone (OR 2.97). Of note, no difference was found in measures of socioeconomic disadvantage, reflecting equitable access to healthcare in the public institution where the care was studied. As previously shown, patients with neoplasia had multiple markers of increased cumulative burden of inflammation, including more IBD-related hospital admissions, elevated inflammatory markers and severe inflammation at colonoscopy. CONCLUSIONS: This study confirms poor adherence or engagement with care as a new risk factor for colorectal adenocarcinoma in patients with IBD; identifying a vulnerable group whom clinicians should endeavour to engage in order to avoid this catastrophic complication.

Modified Zenker's peroral endoscopic myotomy: a novel technique to improve access and depth of muscular dissection.

Video 1The modified Zenker's peroral endoscopic myotomy technique to treat a large Zenker's diverticulum.

Predictors of interhospital transfer delays in acute surgical patient deaths in Australia: a retrospective study.

BACKGROUND: Interhospital transfers in Australia facilitate access to acute surgical services, however transfer delays can occur. The aims of this study were to examine Australian mortality audit data on acute surgical patients who were transferred after presenting with a surgical emergency, and to identify modifiable predictors of transfer delay. METHODS: Surgical admissions between 1 January 2001 and 18 August 2020 were retrospectively extracted from the Australian and New Zealand Audit of Surgical Mortality database. Relevant factors and themes of interest were collated. Results were presented as odds ratios (OR) and 95% confidence intervals (CI), with statistical significance defined as P <0.05. RESULTS: After exclusion, a final 8270 cases were analysed. Non-modifiable predictors identified were female gender (OR 1.34, 95% CI 1.05-1.70, P = 0.0184), comorbidities (OR 1.50, 95% CI 1.40-161, P <0.0001) and major non-trauma non-vascular specialty (OR 1.54 to 7.77, depending on specialty, P < 0.05). Modifiable predictors were inadequate clinical assessment (OR 49.48, 95% CI 32.91-74.38, P <0.0001), poor communication (OR 6.62, 95% CI 3.70-11.85, P <0.0001) and multiple transfers (OR 6.30, OR 95% 4.31-9.21, P <0.0001). Age, lack of bed and after-hours transfer did not predict transfer delays. Metropolitan transfers was protective against transfer delays (OR 0.64, 95% CI 0.47-0.86, P = 0.0035). CONCLUSION: In the view of the receiving surgeon or assessor, all transfer delays potentially contributed to patient deaths, and may have been preventable. Strategies directed at modifiable factors could minimize delays. Increased surgical services in non-metropolitan regions could reduce need for transfer. Prospective data is required to examine if the same predictors are observed in surgical patients who survive.

Factors influencing interhospital transfer delays in emergency general surgery: a systematic review and narrative synthesis.

BACKGROUND: Emergency general surgery is an emerging public health issue globally, with substantial healthcare burden. Interhospital transfer of critically unwell surgical patients has been the mainstay of bridging gaps in surgical coverage in regional and rural locations, despite evidence of greater morbidity and mortality. Delays in transfer invariably occurs and compounds the situation. Our aim was to examine the factors influencing interhospital transfer delays in emergency general surgical patients. METHODS: A systematic search of PubMED and EmBase, was performed by two researchers from 2020 to 23rd Feb 2021, for English articles related to interhospital transfer delays in emergency general surgical patients, with an age of >16. Articles were critically appraised and data were extracted into a pre-specified data extraction form. No data was suitable for statistical analysis and a narrative synthesis was performed instead. RESULTS: Six relevant articles were identified from the search. All studies were retrospective cohort studies with moderate to high risk of bias. Lack of consultant surgeon input, after hours transfer, need for intensive care bed and poor transfer documentation may have a role in interhospital transfer delays. Patients with public health insurance, multiple comorbidities and non-emergency medical conditions experience longer transfer request time and may be at risk of precipitating interhospital transfer delays. Transfer delays are seen in transfers over longer distances. CONCLUSION: There is a paucity of knowledge on what and how factors influence interhospital transfer delays in emergency general surgical patients. Well-designed prospective cohort studies are required to bridge this knowledge gap.

Pathophysiology of Dysphagia in Eosinophilic Esophagitis: Causes, Consequences, and Management.

Eosinophilic esophagitis (EoE) is a leading cause of food bolus impaction in children and adults. The mechanism of dysphagia in EoE, particularly non-obstructive dysphagia, remains incompletely understood. While fibrostenotic processes appear to be critical in the development of dysphagia, somatosensory dysfunction and dysmotility also contribute. This review considers potential mechanisms of dysphagia and evaluates the utility of current and future treatment strategies in this context.

Mucosal imaging in colon polyps: New advances and what the future may hold.

An expanding range of advanced mucosal imaging technologies have been developed with the goal of improving the detection and characterization of lesions in the gastrointestinal tract. Many technologies have targeted colorectal neoplasia given the potential for intervention prior to the development of invasive cancer in the setting of widespread surveillance programs. Improvement in adenoma detection reduces miss rates and prevents interval cancer development. Advanced imaging technologies aim to enhance detection without significantly increasing procedural time. Accurate polyp characterisation guides resection techniques for larger polyps, as well as providing the platform for the "resect and discard" and "do not resect" strategies for small and diminutive polyps. This review aims to collate and summarise the evidence regarding these technologies to guide colonoscopic practice in both interventional and non-interventional endoscopists.

Endoscopic diagnosis and treatment of gastric dysplasia and early cancer: Current evidence and what the future may hold.

Gastric cancer accounts for a significant proportion of worldwide cancer-related morbidity and mortality. The well documented precancerous cascade provides an opportunity for clinicians to detect and treat gastric cancers at an endoscopically curable stage. In high prevalence regions such as Japan and Korea, this has led to the implementation of population screening programs. However, guidelines remain ambiguous in lower prevalence regions. In recent years, there have been many advances in the endoscopic diagnosis and treatment of early gastric cancer and precancerous lesions. More advanced endoscopic imaging has led to improved detection and characterization of gastric lesions as well as superior accuracy for delineation of margins prior to resection. In addition, promising early data on artificial intelligence in gastroscopy suggests a future role for this technology in maximizing the yield of advanced endoscopic imaging. Data on endoscopic resection (ER) are particularly robust in Japan and Korea, with high rates of curative ER and markedly reduced procedural morbidity. However, there is a shortage of data in other regions to support the applicability of protocols from these high prevalence countries. Future advances in endoscopic therapeutics will likely lead to further expansion of the current indications for ER, as both technology and proceduralist expertise continue to grow.