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Natural volcanic glasses are well represented in the geologic record, and typically contain near‐ideal single‐domain particles required for standard Thellier‐type absolute paleointensity experiments. Young (<∼50–100 ka) glasses have been demonstrated to reliably record Earth's magnetic field. However, it is unclear how the magnetic mineralogy and magnetization might change with age as the metastable glass structure relaxes. Here, we attempt to systematically address issues surrounding glass relaxation and devitrification. We subjected a set of natural basaltic and rhyolitic glasses to controlled annealing experiments at temperatures between 200°C and 400°C and assessed how the magnetic properties and glass structure (as assessed by the glass transition temperature, Tg) change over time. We compare the results to bulk magnetic properties and Tg for a suite of volcanic glasses spanning over seven orders of magnitude in age. Annealed samples show an increase in isothermal remanent magnetization acquisition, a decrease in coercivity, and basaltic samples show an increase in unblocking temperatures. The results are consistent with a coarsening of pre‐existing magnetic particles rather than precipitation of new oxides. The natural data are more difficult to interpret, but trends in average parameters are consistent with a coarsening of magnetic particles in some—but not all—samples with age, and this appears to be accompanied by a reduction in Tg. While the annealing experiments take place under many different thermodynamic conditions compared to naturally aged samples, we suggest caution when using geologically older glasses for paleointensity analyses.

Determining the age of the geomagnetic field is of paramount importance for understanding the evolution of the planet because the field shields the atmosphere from erosion by the solar wind. The absence or presence of the geomagnetic field also provides a unique gauge of early core conditions. Evidence for a geomagnetic field 4.2 billion-year (Gy) old, just a few hundred million years after the lunar-forming giant impact, has come from paleomagnetic analyses of zircons of the Jack Hills (Western Australia). Herein, we provide new paleomagnetic and electron microscope analyses that attest to the presence of a primary magnetic remanence carried by magnetite in these zircons and new geochemical data indicating that select Hadean zircons have escaped magnetic resetting since their formation. New paleointensity and Pb-Pb radiometric age data from additional zircons meeting robust selection criteria provide further evidence for the fidelity of the magnetic record and suggest a period of high geomagnetic field strength at 4.1 to 4.0 billion years ago (Ga) that may represent efficient convection related to chemical precipitation in Earth’s Hadean liquid iron core.

Young natural volcanic glasses have been successfully used to recover Earth’s geomagnetic field intensity (paleointensity). However, the magnetic stability and reliability of volcanic glass as a paleomagnetic recorder over geologic time is unclear. Paleointensity estimates may be influenced by natural processes that alter magnetic mineralogy. Previous results from paleointensity and rock magnetic experiments suggest that post-emplacement hydrothermal alteration can alter the magnetic remanence and can possibly cause paleointensity experiments to fail. Low-temperature hydration and natural relaxation of the glass structure over time may also adversely impact paleointensity results. In this study, rhyolitic and basaltic glass specimens underwent artificial aging and artificial hydration treatments to observe how the magnetic mineralogy and resulting magnetic properties are affected. The fresh rhyolitic glass contained pseudo-single-domain to multidomain low-Ti titanomagnetite, and basaltic glass contained single-domain and superparamagnetic grains of medium to low-Ti titanomagnetite. Artificial aging took place by heating in air at 200–400 °C under anhydrous conditions for up to 240 days. Hydration was induced at 200 MPa pressure with elevated temperatures of 300 °C and 450 °C at different time intervals. Before and after aging or hydration, samples underwent experimental procedures to assess the impact of the aging or hydration treatments on magnetic mineralogy and behavior during paleointensity experiments. Aged samples were subject to a modified Thellier-Thellier paleointensity experiment, isothermal remanent magnetization (IRM) acquisition experiments, hysteresis and first order reversal curve (FORC) experiments, and thermal demagnetization of a three-component IRM. Hydrated samples were subject to hysteresis and FORC experiments, and IRM acquisition experiments. IRM acquisition experiments on artificially aged samples showed increases in saturation IRM and a decrease in coercivity in both rhyolitic and basaltic glass specimens. These trends in magnetic properties are believed to have arisen from a growth of existing grains within the basaltic and rhyolitic glasses. Paleointensity experiments showed that with increased aging temperature, basaltic glasses experience more alteration during paleointensity laboratory reheating experiments. This is not seen in rhyolitic glasses. Hydration experiments resulted in inconsistent changes in coercivity and magnetization over treatment. Changes in coercivity and magnetization in basaltic glasses were much greater than rhyolitic glasses. These changes may be explained by magnetic grain growth, loss of material, select dissolution of the finest magnetic grains, and possible oxidation in basaltic glass samples based on IRM experiments. Hydration rims appeared prominently in nearly all hydrated samples, with some rhyolitic glasses experiencing a hydrated interior while only one basaltic sample showed hydration within the interior. While young volcanic glass could be used as a good paleomagnetic recorder, results of this study suggest that older material might pose several problems. Older material could be hydrated, rehydrated, or have a change in the glass structure that results in a change in the magnetic mineral assemblage and therefore incorrect paleointensity and paleomagnetic data. It is recommended that the glass properties and hydration states of older glasses should be further studied before carrying out paleomagnetic studies.

In England, psychological therapies provided in primary care are recommended as first-line treatment for people living with mild-to-moderate dementia experiencing depression or anxiety. It is known that people living with dementia experience more barriers to accessing therapy than people without dementia, but such inequalities in terms of rates of access to primary care services are yet to be characterised. In this retrospective, observational study of linked electronic healthcare records, the national database of the National Health Service (NHS) Talking Therapies for anxiety and depression programme was used to compare pathways to accessing therapy between 6623 people living with dementia and 4 825 489 without dementia between 2012 and 2019. Outcomes included access to an assessment, to therapy and reasons for discharge. Primary analyses used a propensity-score matched cohort to compare outcomes. Exact matching was used for the NHS service entity. The prevalence of dementia in the study cohort was lower than the prevalence of dementia in a representative population, based on an estimation of prevalence in people with mild-to-moderate age over 35 (0.23% in our study vs 3.82% in previous research). Compared to people without dementia, people living with dementia were less likely to access an assessment (odds ratio [OR] = 0.60; 95% confidence interval [CI]: 0.55-0.65), to subsequently receive therapy (OR = 0.67; 95% CI: 0.61-0.73) and more likely to be discharged because services were deemed not suitable before having an assessment (relative rate ratio [RRR] = 4.90; 95% CI: 4.20-5.72) and starting therapy (RRR = 2.74; 95% CI: 2.24-3.35). Female gender, social deprivation, Asian ethnicity and less common dementia subtypes (such as frontotemporal dementia) were also associated with poorer access rates and a higher likelihood of services being deemed not suitable. Involvement of care partners in the referral process was associated with better access rates. Pathways to accessing primary care psychological therapy services must be made more accessible for people living with dementia. Better access could be achieved by increasing referrer awareness and training for staff within services to promote access for people living with dementia (especially for groups under-represented in services), better understanding how to involve care partners in the process, as well as when specialist support might be more suited in secondary care. More granularity in the medical coding of rarer dementia diagnoses in electronic health records would also allow for better statistically powered research for these groups.

Background Psychological therapies are recommended for people living with dementia who experience depression or anxiety. However, people living with dementia often experience specific barriers to accessing services providing such interventions, notably due to the stigma associated with dementia. This study sought to understand pathways to entering and receiving treatment after referral to primary care psychological therapy services for people living with, versus without dementia. Method Linked national data from England from over 4 million individuals referred to NHS Talking Therapies for anxiety and depression (NHS TTad) services were used to identify 6623 people living with dementia referred to these services between 2012 19. We compared rates of access and entry into treatment between people living with dementia and a propensity score matched cohort of people without a diagnosis of dementia, adjusting for a range of socio‐demographic (age, gender, ethnicity) and therapy factors (e.g waiting times). Result We found that once people living with dementia were referred to NHS TTad, they were less likely to access services (ie actually receive an assessment) [AdjOR = 0.61 (0.56; 0.67) p<.0001]. Once assessed, they were also less likely to receive treatment [AdjOR = 0.68 (0.62;0.75, p<.0001] than people with no diagnosis of dementia. Services were twice as likely to be deemed “not suitable” (based on discharge codes recorded by clinicians) for people living with dementia [AdjRRR = 1.97 (1.68; 2.30) p<.0001]. were similar between typical (e.g., memory‐led Alzheimer’s disease) dementias, and atypical dementias (e.g. frontotemporal dementia). Conclusion This study highlights inequalities in access to psychological therapies for people living with dementia. There is a need to make services more accessible to improve the rate of treatment initiation for people living with dementia that are referred and assessed for psychological therapies.

Background Prior research has highlighted that people living with dementia experiencing depression or anxiety can benefit from psychological therapies delivered in primary care. Yet, studies have mainly focused on common dementia types, leaving a gap in evidence for more atypical dementias, and especially those that are not memory‐led. This evaluation is crucial, given the unique challenges posed by these subtypes, such as syndrome‐specific symptoms of changes in personality or visual processing. This study assesses the effectiveness of psychological therapies provided in primary care settings for individuals with atypical dementia subtypes. Method Linked national data from over 2 million individuals in the UK who received a course of therapy in NHS Talking Therapies for Anxiety and Depression services were used to identify 523 individuals with atypical dementias who attended therapy between 2012 and 2019. We compared their depression and anxiety outcomes to a cohort of individuals with no diagnosis of dementia. Result People with atypical dementia had similar outcomes compared to people with typical dementia [Reliable improvement from depression and anxiety symptoms: AdjOR 1.08 (0.86; 1.36) p = 0.4850], but their therapy outcomes were poorer when compared to the matched cohort without dementia [Reliable improvement: AdjOR 0.70 (0.53; 0.91) p = 0.0150]. Conclusion People with atypical dementia who experience depression or anxiety may benefit from psychological therapies provided in primary care. Their outcomes are poorer than those of people who do not have dementia. These results suggest a need to increase access to psychological therapies for people with atypical dementia and offer interventions that are better tailored to their specific experiences.

INTRODUCTION People with dementia may benefit from psychological therapies for depression or anxiety, but evidence of their effectiveness in atypical dementia is limited. METHODS Using electronic health‐care records of > 2 million people who attended psychological therapy services in England between 2012 and 2019, we examined pre–post therapy symptom changes and compared therapy outcomes among 523 people with atypical dementia, a matched cohort without dementia, and 1157 people with typical dementia. RESULTS People with atypical dementia experienced reductions in depression (Cohen d = −0.92 [−1.05 to −0.79]) and anxiety (d = −0.85 [−0.98 to −0.73]) symptoms. They had similar odds of improvement than people with typical dementia (odds ratio [OR] = 1.07, 95% confidence interval [CI]: 0.85 to 1.34), but lower odds than people living without dementia (OR = 0.70, 95% CI: 0.53 to 0.91). Reasons for discharge were similar between all groups. DISCUSSION People with atypical dementia may benefit from primary care psychological therapies, but further research is needed to explore necessary adaptations. Highlights Talking therapies for depression and anxiety may be beneficial for people with atypical dementia. Being younger and having a lower socioeconomic background are associated with poorer outcomes. Receiving more treatment sessions and shorter waiting times are associated with better outcomes.