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Testing the heterotic string with the axion-photon coupling
Get PDFThe discovery of an axion-like particle above the QCD line would rule out Grand Unified Theories, including the perturbative heterotic string with the Standard Model embedded in a single E8 factor or SO(32). In this work we study a possible loophole to this observation, given by compactifications of the E8 × E8 heterotic string with a non-standard embedding of the Standard Model into the 10-dimensional gauge group. If electromagnetism is embedded into both E8 factors, axions can couple to photons via the anomaly without coupling to QCD. We obtain upper bounds to the coupling-to-mass ratio gaγ/ma for these axion-like particles as a function of the supersymmetry breaking scale and the unified gauge coupling. To be compatible with the measured gauge couplings and the weak mixing angle sin2θw at low-energies, phenomenologically viable models with non-standard U(1)Y embedding require sizeable one-loop threshold corrections from string states and/or charged matter at intermediate energy scales. We study how these effects modify the tree-level upper bounds to gaγ/ma and show that, in the perturbative regime, they reduce the leading order estimates. Axion-like particles far above the QCD line are only possible in certain models where perturbation theory is lost. The main conclusion is that the discovery of an axion violating the bounds found in this work would be incompatible with large classes of otherwise phenomenologically viable string models, including the perturbative heterotic SO(32) and E8 × E8 string, the type-I string, and certain heterotic M-theories. The role of small gauge instantons and worldsheet instantons in making some of the axion-like particles heavy and cosmologically relevant is briefly discussed
Endemic and invisible: Visceral Leishmaniasis a One Health imperative in the Somali’s fragile health landscape
Get PDFVisceral Leishmaniasis (VL) remains one of the most neglected public-health challenges in the Horn of Africa. This editorial highlights the ecological, social, and political determinants driving VL persistence across the Somali Peninsula, including Somalia, the Somali Region of Ethiopia, and northeastern Kenya. It synthesises evidence on vector ecology, diagnostic and treatment gaps, and the humanitarian dimensions of disease vulnerability, arguing for a One Health, primary-care-anchored approach to prevention and control. The paper calls for renewed national commitment, regional coordination, and donor alignment to integrate VL into health-system-strengthening and universal health coverage agendas in fragile settings
Determining the best discriminatory physical functioning outcome measurement instrument for psoriatic arthritis trials: a meta-epidemiological study
Get PDFObjectives: To empirically compare the discriminant capacities of three outcome measurement instruments for assessment of physical functioning for psoriatic arthritis (PsA): HAQ-DI, SF36-PF and SF36-PCS.Methods: We applied a network meta-analysis technique in a sample of randomized trials (RCTs) for PsA. For randomized comparison, we calculated net effect size estimates for each outcome measurement instrument using standardized mean differences (SMDs); positive values indicated a beneficial effect of the intervention compared to the control groups. We analyzed the differences between outcome measurement instruments at the trial level by applying a multiple-treatment meta-analysis to compare the SMDs within and across randomized comparisons for each outcome measurement instrument.Results: From 42 articles (31 RCTs), 57, 18, and 18 randomized comparisons enabled a direct comparison between HAQ-DI and SF36-PCS (difference in SMDs: 0.057, 95% confidence interval, CI: 0.003 to 0.110), SF36-PF and SF36- PCS (difference in SMDs: 0.101, 95% CI: 0.018 to 0.184); and HAQ-DI and SF36-PF (difference in SMDs: -0.059, 95% CI: -0.142 to 0.024), respectively. The network meta-analysis technique confirmed that both HAQ-DI and SF36-PF were more responsive to change than SF36-PCS, with differences between SMDs of 0.057 (95% CI: 0.003 to 0.110) and 0.109 (95% CI: 0.032 to 0.185), respectively. No difference in discriminatory capacity between HAQ-DI and SF36-PF was noted.Conclusions: HAQ-DI and SF-36-PF were equally responsive to change and superior to SF36-PCS in PsA RCTs. We illustrated a new method for quantitative comparison of the performance of different outcome measurement instruments for a particular domain.Systematic review registration number: Registered on PROSPERO: CRD4201912955
Moving from a ‘zone of inaction’ to a ‘zone of possibility’: how teachers can improve climate change education policy in India
Get PDFThe climate crisis presents itself as one of the biggest challenges of our time. Resulting in the large-scale loss of livelihoods, destruction of homes and schools, and a significant loss of lives; the effects of this crisis are particularly pronounced in India and demand urgent and immediate attention. There is a growing need for climate adaptation and climate change education (CCE) that empowers its children to face and combat the dire effects of the climate crisis. In recent years, India has introduced two significant educational policies: the National Educational Policy (NEP, 2020) and the National Curriculum Framework (NCF, 2023) that address CCE and outline processes for its effective implementation, positioning teachers as central actors responsible for the effective implementation of CCE.The current research on the interplay between teacher agency and CCE in India is limited. The existing literature portrays teachers as facing multiple structural and systemic challenges and being often held responsible for the declining educational quality in India. Additionally, the inclusion of teacher voice and involvement in policy design and review is limited. The combination of these challenges results in a situation where teachers could potentially be positioned in what could be conceptualised as a ‘zone of inaction’ in relation to implementing CCE policy in India.Through semi-structured interviews, this study critically explores teachers’ perceptions of CCE, their beliefs on its importance, and their exercise of agency in actively engaging with these policies to facilitate the efficient and sustainable implementation of CCE in India. It employs a constructivist and epistemic justice lens to investigate what adaptations to these policies, in their opinion, would be impactful. The findings reveal that while teachers encounter multiple systemic and structural barriers, they are also actively involved in implementing CCE in their respective contexts and offer practical recommendations to strengthen CCE policy in India.Building on these findings, the study argues that it is possible to shift from a ‘zone of inaction’ to a ‘zone of possibility’ in CCE by strengthening teachers’ agency, incorporating their recommendations in policy, and actively involving teachers in policy design and review. At the heart of this study lies the understanding that involving teachers actively in the policy development process and acknowledging their agency as pivotal to policy success makes educational policies considerably more effective
What public reason liberals do and do not need to say about epistemology
Get PDFAn important question regarding public reason liberalism is how much (if anything) it needs to say about epistemology. This paper presents an answer to this question, arguing that the theory does not require reasonable citizens to hold any particular epistemological commitments (contra David Enoch’s important critique), but does need to offer an epistemological explanation for the fact of reasonable disagreement. However, that explanation can be sufficiently minimal to be compatible with a wide range of fuller epistemological views. Further, the paper argues that this account of the place of epistemology within public reason liberalism mirrors the theory’s structure with respect to moral justification, and indeed its approach to various other philosophical domains
Open-world object counting in videos
No full textWe introduce a new task of open-world object counting in videos: given a text description, or an image example, that specifies the target object, the objective is to enumerate all the unique instances of the target objects in the video. This task is especially challenging in crowded scenes with occlusions and objects of similar appearance, where avoiding double counting and identifying reappearances is crucial. To this end, we make the following contributions: we introduce a model, COUNTVID, for this task. It leverages an imagebased counting model, and a promptable video segmentation and tracking model, to enable automated open-world object counting across video frames. To evaluate its performance, we introduce VIDEOCOUNT, a new dataset for this novel task built from the TAO and MOT20 tracking datasets, as well as from videos of penguins and metal alloy crystallization captured by x-rays. Using this dataset, we demonstrate that COUNTVID provides accurate object counts, and significantly outperforms strong baselines
Crystal-facet-directed all vacuum-deposited perovskite solar cells
Get PDFVacuum-based deposition is a scalable, solvent-free industrial method ideal for uniform coatings on complex substrates. However, all vacuum-deposited perovskite solar cells fabricated by thermal evaporation trail solution-processed counterparts in efficiency and stability due to film quality challenges, necessitating advancement and improved understanding. Here, we report a co-evaporation route for 1.67-eV wide-bandgap perovskites by introducing a PbCl2 co-source to optimize film quality. We promote perovskite formation with pronounced (100) “face-up” orientation and deliver a certified all vacuum-deposited solar cell with 18.35% efficiency (19.3% in the lab) for 0.25-cm2 devices (18.5% for 1-cm2 cells). These cells retain 80% of peak efficiency after 1,080 hours under the ISOS-L-2 protocol. Leveraging operando hyperspectral imaging, we provide spatiotemporal spectral insight into halide segregation and trap-mediated recombination, correlating microscopic luminescence features with macroscopic device performance while distinguishing radiative from non-ideal recombination channels. We further demonstrate 27.2%-efficient 1-cm2 evaporated perovskite-on-silicon tandems and outdoor stability of all vacuum-deposited tandems in Italy, retaining ~80% initial performance after 8 months
Identification of anterodorsal thalamic head direction cell types and their role in spatial disorientation
No full textHead direction signalling is fundamental for spatial orientation and navigation. The anterodorsal nucleus of the thalamus (ADn) contains a high density of head direction (HD) cells. This hub of HD cells is acting as a neural compass. The first part of the thesis tests this dogma and defines the diversity of ADn HD cells based on the combination of neurochemical identity, firing patterns, and connectivity. Using in vivo extracellular recordings and juxtacellular labelling, I observed HD cells exhibiting different response profiles to light pulses, sound, and movement, whereas others remained unresponsive. I identified a mediolateral gradient of calretinin-expressing (CR+) ADn cells, with CR+ HD cells having narrower tuning widths, lower peak and maximal firing rates compared to CR- cells. By examining the connectivity of ADn HD cells, I identified 3 projection patterns: type I cells followed the ‘typical’ route via the thalamic reticular nucleus (TRN) and dorsomedial striatum (DMS) to enter the cingulum bundle; type II cells formed additional collaterals in the DMS; and type III cells avoided the TRN and had descending axons. These data suggest that ADn HD cells formed of distinct cell types. Given the crucial role of the ADn in spatial navigation and its early vulnerability to pathological forms of tau – a hallmark of Alzheimer’s disease and ageing – the second part of the thesis addresses how tau pathology in the HD network promotes spatial disorientation. I virally expressed human mutant tau in the mouse ADn (HD-tau mice) and observed phosphorylated and oligomeric forms of tau in ADn somata and axon terminals. During initial spatial learning in the Morris water maze, HD-tau mice exhibited increased looping behaviour, indicative of spatial disorientation. Furthermore, I found that ADn cells from HD-tau mice had reduced directionality and altered burst firing. These findings provide evidence that pathological human tau alters HD signalling, leading to impairments in spatial orientation. Overall, this thesis demonstrates the existence of a diverse anterodorsal thalamic head direction neuronal population and their dysfunction promotes spatial disorientation
Evaluating the impact of structured reporting for post-operative ultrasound on management and survival in liver transplant patients
No full textLiver transplantation has the potential for life saving results in patients with end-stage liver disease. Transplantation is however a complex procedure that requires early post-surgical monitoring with ultrasound (US) to improve the chances of success. The communication of US results before and after the introduction of a structured reporting template was assessed to determine if the change in reporting practices impacted on the management patients and their survival following liver transplant. 125 patients from before and 112 patients from after the introduction of the template were analysed. The changes in frequency of reporting of key components of the liver US, the use of computed tomography (CT) within 30 days, re-operation within 30 days and survival were assessed using logistic regression for binary outcomes and Kaplan-Meier and Cox regression for time-to-event analyses. After the introduction of structured reporting, there were increases in the communication of the presence or absence of ascites, portal vein flow direction and patency of the splenic vein. There were also increases in the use of CT, OR 2.2 (95% CI 1.3-3.8) and in the likelihood of CT detecting a vascular abnormality, OR 1.05 (95% CI 1.01 to 1.09). The likelihood of re-operation also increased, OR 2.2 (95% CI 1.1 to 4.7). No difference was found in early survival before and after the US template introduction (Barlow p-value = 0.077), but the longer-term survival of the post template group was lower (Log rank p-value = 0.007 and Taron-Ware p-value = 0.027). These results show that structured reporting affects key components of US report communication and that there are changes in further imaging and surgical management decisions and to long-term survival that could be related to the communication changes. Careful consideration should therefore be given to the composition of any structured reporting templates before implementatio
Deep learning‐based ecological analysis of camera trap images is impacted by training data quality and quantity
Get PDFLarge image collections generated from camera traps offer valuable insights into species richness, occupancy, and activity patterns, significantly aiding biodiversity monitoring. However, the manual processing of these data sets is time‐consuming, hindering analytical processes. To address this, deep neural networks have been widely adopted to automate image labelling, but the impact of classification error on key ecological metrics remains unclear. Here, we analyze data from camera trap collections in an African savannah (82,300 labelled images, 47 species) and an Asian sub‐tropical dry forest (40,308 labelled images, 29 species) to compare ecological metrics derived from expert‐generated species identifications with those generated by deep‐learning classification models. We specifically assess the impact of deep‐ learning model architecture, the proportion of label noise in the training data, and the size of the training data set on three key ecological metrics: species richness, occupancy, and activity patterns. We found that predictions of species richness derived from deep neural networks closely match those calculated from expert labels and remained resilient to up to 10% noise in the training data set (mis‐labelled images) and a 50% reduction in the training data set size. We found that our choice of deep‐learning model architecture (ResNet vs. ConvNext‐T) or depth (ResNet18, 50, 101) did not impact predicted ecological metrics. In contrast, species‐specific metrics were more sensitive; less common and visually similar species were disproportionately affected by a reduction in deep neural network accuracy, with consequences for occupancy and diel activity pattern estimates. To ensure the reliability of their findings, practitioners should prioritize creating large, clean training sets and account for class imbalance across species over exploring numerous deep‐learning model architectures