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Digital health app data reveals an effect of ovarian hormones on long covid and myalgic encephalomyelitis symptoms
No full textThe UKRI Strategic Priorities Fund Greenhouse Gas Removal Demonstrators (GGR-D) Programme: an overview of key research insights and cross-cutting lessons
No full textIntensity control of few-cycle laser pulses
No full textControlling the intensity of few-cycle laser pulses—often with fine and continuous tunability—is essential for
applications ranging from strong-field physics and attosecond science to ultrafast spectroscopy, nonlinear optics, and precision material processing. Yet this remains challenging due to their octave-spanning bandwidth and high sensitivity to dispersion. Conventional polarization-based methods typically rely on ultrabroadband optics, which are complex and costly. We demonstrate a robust and broadly applicable approach that enables precise intensity control while avoiding these demanding optical requirements. Applied to an ∼800 nm laser, the method allows pulse energy tuning over a factor of ∼25 while maintaining a sub-6 fs pulse duration after post compression in an argon-filled hollow fiber and chirped mirror system. Validation through high-harmonic generation in krypton reveals clear intensity-dependent harmonic yields across 30−190 TW/cm². This work provides a practical and effective route to stable, tunable few-cycle pulses for both experimental and applied settings
Longitudinal association of infant and early childhood body mass index with childhood and adolescent mental health: a Mendelian randomization study
No full textNo need for explanations: LLMs can implicitly learn from mistakes in-context
No full textShowing incorrect answers to Large Language Models (LLMs) is a popular strategy to improve their performance in reasoning-intensive tasks. It is widely assumed that, in order to be helpful, the incorrect answers must be accompanied by comprehensive rationales, explicitly detailing where the mistakes are and how to correct them. However, in this work we present a counterintuitive finding: we observe that LLMs perform *better* in math reasoning tasks when these rationales are eliminated from the context and models are left to infer on their own what makes an incorrect answer flawed. This approach also substantially outperforms chain-of-thought prompting in our evaluations. These results are consistent across LLMs of different sizes and varying reasoning abilities. To gain an understanding of *why* LLMs learn from mistakes more effectively without explicit corrective rationales, we perform a thorough analysis, investigating changes in context length and answer diversity between different prompting strategies, and their effect on performance. We also examine evidence of overfitting to the in-context rationales when these are provided, and study the extent to which LLMs are able to autonomously infer high-quality corrective rationales given only incorrect answers as input. We find evidence that, while incorrect answers are more beneficial for LLM learning than additional diverse *correct* answers, explicit corrective rationales over-constrain the model, thus limiting those benefits
Squeezing shorts through social media platforms
No full textIn January 2021, a group of stocks listed on US stock exchanges experienced sudden price increases, which – coupled with high short interest – led to short squeezes. We find that discussions on social media fueled the association between retail trading and subsequent stock returns. Options market activity and securities lending constraints also played a central role. Using unique data from social media platforms we provide a comprehensive account of these short squeezes. We find that they significantly impeded market quality for the stocks at issue and their competitors. Thus, the interplay between social media and retail traders may have adverse consequences for market quality and efficiency
Drugs targeting the NO-sGC-cGMP pathway in the treatment of patients with COPD-associated pulmonary hypertension: a systematic review
No full textBackground: Pulmonary hypertension (PH) due to chronic obstructive pulmonary disease (COPD) is categorized as group 3 PH and is associated with increased mortality and morbidity. Currently, there are no approved therapies for those who have PH secondary to COPD due to conflicting evidence. Therefore, this systematic review aims to summarize the current evidence on the effectiveness of drugs targeting the nitric oxide (NO)-soluble guanylate cyclase (sGC)-cyclic guanosine monophosphate (cGMP) pathway on clinical outcomes among patients with COPD-associated PH.
Methods: We conducted a comprehensive search of electronic databases, including Embase, Medline, Cochrane, and Scopus, from inception to 1 February 2024. Studies investigating the efficacy of drugs targeting the NO-sGC-cGMP pathway on clinical outcomes in patients with COPD-associated PH were included. Exclusion criteria encompassed case reports, systematic reviews, review articles, conference abstracts with no full text, non-full-text articles, non-English manuscripts, opinion articles, and book chapters. Two distinct Cochrane risk-of-bias tools designed for randomized and non-randomized clinical trials were used to evaluate the risk of bias within the selected studies for inclusion.
Results: Fourteen studies, comprising a total of 567 adult patients diagnosed with PH secondary to COPD, met the inclusion criteria and were included in this systematic review. Among these, nine studies reported significant improvements in clinical parameters related to pulmonary hemodynamics. Improvement in exercise capacity was observed in four out of seven studies. Three studies evaluated dyspnea severity and quality of life following treatment with agents targeting the NO-sGC-cGMP pathway. Of these, three demonstrated improvement in dyspnea severity while two reported enhancements in health-related quality of life. Substantial heterogeneity was evident regarding the potential of pharmacological agents targeting the NO-sGC-cGMP pathway to enhance gas exchange, lung function, and arterial oxygenation in COPD patients with concurrent PH.
Conclusion: The short-term use of oral drugs targeting the NO-sGC-cGMP pathway, particularly sildenafil, demonstrates promising potential for enhancing pulmonary hemodynamics, exercise capacity, dyspnea severity, and health-related quality of life but not lung function and oxygenation status in adult patients with COPD-associated PH. Further double-blind, randomized, placebo-controlled trials are needed to assess the therapeutic benefits of agents targeting the NO-sGC-cGMP pathway, particularly inhaled therapies for managing PH due to COPD.
Systematic Review Registration: https://www.crd.york.ac.uk/prospero/#recordDetails, CRD42023453503
Hothouse hydrology: evolving river dynamics in the Eocene Montllobat and Castissent formations, southern Pyrenees
No full textRivers are highly sensitive to climate and tectonic change, and understanding how fluvial systems respond to greenhouse climates in dynamic tectono-geomorphic settings is vital to projecting imminent landscape change in the face of global warming. We look to the southern Pyrenean Tremp-Graus basin during the Early Eocene Climatic Optimum (EECO), analogous to future anthropogenic climate scenarios. We focus on the fluvial deposits of the Montllobat and Castissent Formations, deposited during the early Pyrenean orogeny. This succession records a significant shift in geomorphology involving a 20 km progradation of the shoreline and its feeder rivers in < 0.8 Myrs. Using field-based quantitative palaeohydrology, we reconstruct the evolving morphometry and hydrodynamics of ancient river systems in a foreland basin. The transition from the Montllobat Formation into the Castissent Formation at c. 50.5 Ma is associated with a sharp change in palaeohydraulics: a statistically significant reduction in cross-set height, a 40% increase in water discharge, and a 15% increase in total sediment flux. This intensification in hydrological regime implies a clear climate driver and is compounded with a switch in interpreted fluvial planform morphology from anastomosing to a dominantly braided planform at the onset of the Castissent interval and a 1.4-fold increase in channel slope. We suggest the transient hydrological signature of the Castissent Formation was driven by Ypresian hyperthermal events superimposed on a levelling-off in the global cooling trend at the end of the EECO and an increase in tectonic uplift rates at c. 50 Ma. This analysis holistically reconstructs the dynamics of ancient rivers in the Eocene Hothouse, and in conjunction with isotope and exhumation records, reveals the potential to extract complex tectono-climatic signals from fluvial stratigraphy
Mechanical and micro-CT study of frost-heave in silty sands
No full textSoil freezing occurs naturally in cold regions where it affects many aspects of geotechnical practice and infrastructure. Moreover, artificial ground freezing can be used to stabilize sandy and silty soils prior sampling, but also as stabilization measure in tunnelling and open excavations. This paper reports a laboratory-based study on the frost-heave response of four silty sand soils from the Øysand Norwegian geotechnical test site. The combined effects of fines content and vertical effective stresses were investigated in a one-dimensional cell with parallel micro-computed tomography to assess the impact of a freeze-thaw cycle. As expected, the higher the fines content the higher the expansion noted on freezing and increasing the vertical effective stress reduced or eliminated frost-heave, the stress levels required to supress heave increasing with fines content. Additionally, micro-CT image analysis added important further insights and shows that freezing may disturb the soil fabric, even when the resulting global strains are too small to measure by conventional means (using an LVDT). The experiments provided crucial evidence regarding the circumstances under which ground freezing could be an effective aid to low-disturbance sampling in silty sands and provides useful information for other geocryological engineering applications in such strata