We use cookies to distinguish you from other users and to provide you with a better experience on our websites. Close this message to accept cookies or find out how to manage your cookie settings.
To save content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about saving content to .
To save content items to your Kindle, first ensure no-reply@cambridge.org
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Exposure to environmentally transmitted parasites should increase with population density due to accumulation of infective parasites in space. However, resource competition also increases with density, lowering immunity and increasing susceptibility, offering an alternative pathway for density-dependent infection. To test the relationships between these two processes and parasitism, we examined associations between host density, resource availability, immunity, and counts of 3 common helminth parasites using a long-term study of red deer. We found evidence that immunity increased with resource availability while parasite counts declined with immunity. We also found that greater density correlated with reduced resource availability, and while density was positively associated with both strongyle and tissue worm burdens, resource availability was independently and negatively associated with the same burdens. Our results support separate roles of density-dependent exposure and susceptibility in driving infection, providing evidence that resource competition is an important driver of infection, exacerbating effects of density-dependent increases in exposure.
Background: Treatment-resistant obsessive compulsive disorder (trOCD) is a condition characterized by intrusive thoughts (obsessions) and uncontrollable behaviours (compulsions) unresponsive to conventional therapies. Lesioning both anterior limbs of the internal capsule is effective in ablating the circuitry underlying trOCD pathophysiology. The newest capsulotomy method is MR-guided focused ultrasound (MRgFUS). Here we measured neural networks changes of trOCD patients after MRgFUS capsulotomy using resting state functional MRI (rs-fMRI). Methods: Yale-Brown Obsessive-Compulsive Scale (YBOCS) scores and rs-fMRI data were collected in 6 trOCD patients preoperatively, postoperatively at 3-months and 1-year, along with rs-fMRI from 6 age and sex-matched controls. Independent component analysis, dual regression using the FMRIB software library, and node-node approaches were used with the CONN Toolbox. We also performed a systematic review of existing studies about trOCD resting state networks. Results: TrOCD patients demonstrated significant improvement 1-year postoperatively (mean YBOCS reduction of 41 ± 7%). Dual regression analysis 3-months postoperatively showed significantly greater sensorimotor network signal in controls compared to trOCD groups. Node-node analysis in trOCD found connectivity changed in networks associated with the cortico-striato-thalamo-cortico loop, particularly the salience and limbic networks at 1-year postoperatively. Conclusions: TrOCD patients who underwent MRgFUS capsulotomy demonstrated differences in sensorimotor and cortico-striatal connectivity and significant clinical improvement postoperatively.
Bipolar depression remains difficult to treat, and people often experience ongoing residual symptoms, decreased functioning and impaired quality of life. Adjunctive therapies targeting novel pathways can provide wider treatment options and improve clinical outcomes. Garcinia mangostana Linn. (mangosteen) pericarp has serotonogenic, antioxidant anti-inflammatory and neurogenic properties of relevance to the mechanisms of bipolar depression.
Aims
The current 28-week randomised, multisite, double-blind, placebo-controlled trial investigated mangosteen pericarp extract as an adjunct to treatment-as-usual for treatment of bipolar depression.
Method
This trial was prospectively registered on the Australia New Zealand Clinical Trials Registry (no. ACTRN12616000028404). Participants aged 18 years and older with a diagnosis of bipolar I or II and with at least moderate depressive symptoms were eligible for the study. A total of 1016 participants were initially approached or volunteered for the study, of whom 712 did not progress to screening, with an additional 152 screened out. Seventy participants were randomly allocated to mangosteen and 82 to a placebo control. Fifty participants in the mangosteen and 64 participants in the placebo condition completed the treatment period and were analysed.
Results
Results indicated limited support for the primary hypothesis of superior depression symptom reduction following 24 weeks of treatment. Although overall changes in depressive symptoms did not substantially differ between conditions over the course of the trial, we observed significantly greater improvements for the mangosteen condition at 24 weeks, compared with baseline, for mood symptoms, clinical impressions of bipolar severity and social functioning compared with controls. These differences were attenuated at week 28 post-discontinuation assessment.
Conclusions
Adjunctive mangosteen pericarp treatment appeared to have limited efficacy in mood and functional symptoms associated with bipolar disorder, but not with manic symptoms or quality of life, suggesting a novel therapeutic approach that should be verified by replication.
Recent changes to US research funding are having far-reaching consequences that imperil the integrity of science and the provision of care to vulnerable populations. Resisting these changes, the BJPsych Portfolio reaffirms its commitment to publishing mental science and advancing psychiatric knowledge that improves the mental health of one and all.
A key step toward understanding psychiatric disorders that disproportionately impact female mental health is delineating the emergence of sex-specific patterns of brain organisation at the critical transition from childhood to adolescence. Prior work suggests that individual differences in the spatial organisation of functional brain networks across the cortex are associated with psychopathology and differ systematically by sex.
Aims
We aimed to evaluate the impact of sex on the spatial organisation of person-specific functional brain networks.
Method
We leveraged person-specific atlases of functional brain networks, defined using non-negative matrix factorisation, in a sample of n = 6437 youths from the Adolescent Brain Cognitive Development Study. Across independent discovery and replication samples, we used generalised additive models to uncover associations between sex and the spatial layout (topography) of personalised functional networks (PFNs). We also trained support vector machines to classify participants’ sex from multivariate patterns of PFN topography.
Results
Sex differences in PFN topography were greatest in association networks including the frontoparietal, ventral attention and default mode networks. Machine learning models trained on participants’ PFNs were able to classify participant sex with high accuracy.
Conclusions
Sex differences in PFN topography are robust, and replicate across large-scale samples of youth. These results suggest a potential contributor to the female-biased risk in depressive and anxiety disorders that emerge at the transition from childhood to adolescence.
The stars of the Milky Way carry the chemical history of our Galaxy in their atmospheres as they journey through its vast expanse. Like barcodes, we can extract the chemical fingerprints of stars from high-resolution spectroscopy. The fourth data release (DR4) of the Galactic Archaeology with HERMES (GALAH) Survey, based on a decade of observations, provides the chemical abundances of up to 32 elements for 917 588 stars that also have exquisite astrometric data from the Gaia satellite. For the first time, these elements include life-essential nitrogen to complement carbon, and oxygen as well as more measurements of rare-earth elements critical to modern-life electronics, offering unparalleled insights into the chemical composition of the Milky Way. For this release, we use neural networks to simultaneously fit stellar parameters and abundances across the whole wavelength range, leveraging synthetic grids computed with Spectroscopy Made Easy. These grids account for atomic line formation in non-local thermodynamic equilibrium for 14 elements. In a two-iteration process, we first fit stellar labels to all 1 085 520 spectra, then co-add repeated observations and refine these labels using astrometric data from Gaia and 2MASS photometry, improving the accuracy and precision of stellar parameters and abundances. Our validation thoroughly assesses the reliability of spectroscopic measurements and highlights key caveats. GALAH DR4 represents yet another milestone in Galactic archaeology, combining detailed chemical compositions from multiple nucleosynthetic channels with kinematic information and age estimates. The resulting dataset, covering nearly a million stars, opens new avenues for understanding not only the chemical and dynamical history of the Milky Way but also the broader questions of the origin of elements and the evolution of planets, stars, and galaxies.
Posttraumatic stress disorder (PTSD) has been associated with advanced epigenetic age cross-sectionally, but the association between these variables over time is unclear. This study conducted meta-analyses to test whether new-onset PTSD diagnosis and changes in PTSD symptom severity over time were associated with changes in two metrics of epigenetic aging over two time points.
Methods
We conducted meta-analyses of the association between change in PTSD diagnosis and symptom severity and change in epigenetic age acceleration/deceleration (age-adjusted DNA methylation age residuals as per the Horvath and GrimAge metrics) using data from 7 military and civilian cohorts participating in the Psychiatric Genomics Consortium PTSD Epigenetics Workgroup (total N = 1,367).
Results
Meta-analysis revealed that the interaction between Time 1 (T1) Horvath age residuals and new-onset PTSD over time was significantly associated with Horvath age residuals at T2 (meta β = 0.16, meta p = 0.02, p-adj = 0.03). The interaction between T1 Horvath age residuals and changes in PTSD symptom severity over time was significantly related to Horvath age residuals at T2 (meta β = 0.24, meta p = 0.05). No associations were observed for GrimAge residuals.
Conclusions
Results indicated that individuals who developed new-onset PTSD or showed increased PTSD symptom severity over time evidenced greater epigenetic age acceleration at follow-up than would be expected based on baseline age acceleration. This suggests that PTSD may accelerate biological aging over time and highlights the need for intervention studies to determine if PTSD treatment has a beneficial effect on the aging methylome.
Objectives/Goals: We describe the prevalence of individuals with household exposure to SARS-CoV-2, who subsequently report symptoms consistent with COVID-19, while having PCR results persistently negative for SARS-CoV-2 (S[+]/P[-]). We assess whether paired serology can assist in identifying the true infection status of such individuals. Methods/Study Population: In a multicenter household transmission study, index patients with SARS-CoV-2 were identified and enrolled together with their household contacts within 1 week of index’s illness onset. For 10 consecutive days, enrolled individuals provided daily symptom diaries and nasal specimens for polymerase chain reaction (PCR). Contacts were categorized into 4 groups based on presence of symptoms (S[+/-]) and PCR positivity (P[+/-]). Acute and convalescent blood specimens from these individuals (30 days apart) were subjected to quantitative serologic analysis for SARS-CoV-2 anti-nucleocapsid, spike, and receptor-binding domain antibodies. The antibody change in S[+]/P[-] individuals was assessed by thresholds derived from receiver operating characteristic (ROC) analysis of S[+]/P[+] (infected) versusS[-]/P[-] (uninfected). Results/Anticipated Results: Among 1,433 contacts, 67% had ≥1 SARS-CoV-2 PCR[+] result, while 33% remained PCR[-]. Among the latter, 55% (n = 263) reported symptoms for at least 1 day, most commonly congestion (63%), fatigue (63%), headache (62%), cough (59%), and sore throat (50%). A history of both previous infection and vaccination was present in 37% of S[+]/P[-] individuals, 38% of S[-]/P[-], and 21% of S[+]/P[+] (P<0.05). Vaccination alone was present in 37%, 41%, and 52%, respectively. ROC analyses of paired serologic testing of S[+]/P[+] (n = 354) vs. S[-]/P[-] (n = 103) individuals found anti-nucleocapsid data had the highest area under the curve (0.87). Based on the 30-day antibody change, 6.9% of S[+]/P[-] individuals demonstrated an increased convalescent antibody signal, although a similar seroresponse in 7.8% of the S[-]/P[-] group was observed. Discussion/Significance of Impact: Reporting respiratory symptoms was common among household contacts with persistent PCR[-] results. Paired serology analyses found similar seroresponses between S[+]/P[-] and S[-]/P[-] individuals. The symptomatic-but-PCR-negative phenomenon, while frequent, is unlikely attributable to true SARS-CoV-2 infections that go missed by PCR.
Antibiotic stewardship programs (ASPs) target hospitalized children, but most do not routinely review antibiotic prescriptions at discharge, despite 30% of discharged children receiving additional antibiotics. Our objective is to describe discharge antibiotic prescribing in children hospitalized for uncomplicated community-acquired pneumonia (CAP), skin/soft tissue infection (SSTI), and urinary tract infection (UTI).
Design:
Retrospective cohort study.
Setting:
Four academic children’s hospitals with established ASPs.
Patients:
ICD-10 codes identified 3,847 encounters for children <18 years admitted from January 1, 2021 to December 31, 2021 and prescribed antibiotics at discharge for uncomplicated CAP, SSTI, or UTI. After excluding children with medical complexity and encounters with concomitant infections, >7 days hospital stay, or intensive care unit stay, 1,206 encounters were included.
Methods:
Primary outcomes were the percentage of subjects prescribed optimal (1) total (inpatient plus outpatient) duration of therapy (DOT) and (2) antibiotic choice based on current national guidelines and available evidence.
Results:
Of 226 encounters for CAP, 417 for UTI, and 563 for SSTI, the median age was 4 years, 52% were female, and the median DOT was 9 days (8 for CAP, 10 for UTI, and 9 for SSTI). Antibiotic choice was optimal for 77%, and DOT was optimal for 26%. Only 20% of antibiotic courses included both optimal DOT and antibiotic choice.
Conclusions:
At 4 children’s hospitals with established ASPs, 80% of discharge antibiotic courses for CAP, UTI, and SSTI were suboptimal either by choice of antibiotic or DOT. Discharge antibiotic prescribing represents an opportunity to improve antibiotic use in children.
We investigate whether compensation consultants recommend excessive pay to earn repeat business by studying consultant changes. Our results show consultants’ interests are aligned with shareholders’ to appropriately pay the CEO. Boards dismiss consultants making large pay recommendation errors, particularly positive ones. However, powerful or poorly monitored CEOs interfere with such disciplinary turnover, weakening the relation. Peer groups are more likely to change with new consultant appointments. New consultants are less likely to include highly paid executives in the compensation peer group and CEO pay falls following the change. Directors earn higher votes in annual elections when they replace compensation advisors.
We consider pricing of a specialised critical illness and life insurance contract for breast cancer (BC) risk. We compare (a) an industry-based Markov model with (b) a recently developed semi-Markov model, which accounts for unobserved BC cases and progression through clinical stages of BC, and (c) an alternative Markov model derived from (b). All models are calibrated using population data in England and data from the medical literature. We show that the semi-Markov model aligns best with empirical evidence. We then consider net premiums of specialized life insurance products under various scenarios of cancer diagnosis and treatment. The results show strong dependence on the time spent with diagnosed or undiagnosed pre-metastatic BC. This proves to be significant for refining cancer survival estimates and accurately estimating related age dependence by cancer stage. In contrast, the industry-based model, by overlooking this critical factor, is more sensitive to the model assumptions, underscoring its limitations in cancer estimates.
Despite the central role that patient and community engagement plays in translational science and health equity research, there remain significant institutional barriers for researchers and their community partners to engage in this work meaningfully and sustainably. The goal of this paper is to describe the process and outcomes of Engage for Equity PLUS at Stanford School of Medicine, which was aimed at understanding and addressing institutional barriers and facilitators for community-engaged research (CEnR).
Methods:
A Stanford champion team of four faculty and two community partners worked with the University of New Mexico team to conduct two workshops (n = 26), focus groups (n = 2), interviews with leaders (n = 4), and an Institutional Multi-Stakeholder Survey (n = 35). These data were employed for action planning to identify strategies to build institutional support for CEnR.
Results:
Findings revealed several key institutional barriers to CEnR, such as the need to modify organizational policies and practices to expedite and simplify CEnR administration, silos in collaboration, and the need for capacity building. Facilitators included several offices devoted to and engaging in innovative CEnR efforts. Based on these findings, action planning resulted in three priorities: 1) Addressing IRB barriers, 2) Addressing barriers in post-award policies and procedures, and 3) Increasing training in CEnR within Stanford and for community partners.
Conclusions:
Addressing institutional barriers is critical for Academic Medical Centers and their partners to meaningfully and sustainably engage in CEnR. The Engage for Equity PLUS process offers a roadmap for Academic Medical Centers with translational science and health equity goals.
Research participants” feedback about their participation experiences offers critical insights for improving programs. A shared Empowering the Participant Voice (EPV) infrastructure enabled a multiorganization collaborative to collect, analyze, and act on participants’ feedback using validated participant-centered measures.
Methods:
A consortium of academic research organizations with Clinical and Translational Science Awards (CTSA) programs administered the Research Participant Perception Survey (RPPS) to active or recent research participants. Local response data also aggregated into a Consortium database, facilitating analysis of feedback overall and for subgroups.
Results:
From February 2022 to June 2024, participating organizations sent surveys to 28,096 participants and received 5045 responses (18%). Respondents were 60% female, 80% White, 13% Black, 2% Asian, and 6% Latino/x. Most respondents (85–95%) felt respected and listened to by study staff; 68% gave their overall experience the top rating. Only 60% felt fully prepared by the consent process. Consent, feeling valued, language assistance, age, study demands, and other factors were significantly associated with overall experience ratings. 63% of participants said that receiving a summary of the study results would be very important to joining a future study. Intersite scores differed significantly for some measures; initiatives piloted in response to local findings raised experience scores.
Conclusion:
RPPS results from 5045 participants from seven CTSAs provide a valuable evidence base for evaluating participants’ research experiences and using participant feedback to improve research programs. Analyses revealed opportunities for improving research practices. Sites piloting local change initiatives based on RPPS findings demonstrated measurable positive impact.
Anhedonia, a multidimensional domain including the reduced ability to experience pleasure, is a core diagnostic symptom of major depressive disorder (MDD) and a common residual symptom. In patients with MDD, anhedonia has been associated with poor treatment outcomes, suicide and reduced functioning and quality of life. This post-hoc analysis of data from a phase 3 trial (NCT03738215) evaluated the efficacy of adjunctive cariprazine (CAR) treatment on anhedonia symptoms in patients with MDD.
Methods
Patients with MDD and inadequate response to ongoing antidepressant therapy (ADT) were randomized to CAR 1.5 mg/d + ADT, CAR 3 mg/d + ADT, or placebo + ADT for 6 weeks of double-blind treatment. Post hoc analyses evaluated the change from baseline to Week 6 in Montgomery–Åsberg Depression Rating Scale (MADRS) total score, MADRS anhedonia subscale score (items: 1 [apparent sadness], 2 [reported sadness], 6 [concentration difficulties], 7 [lassitude], and 8 [inability to feel]), and MADRS anhedonia item 8 in the overall modified intent-to-treat (mITT) population and in subgroups of patients with baseline MADRS anhedonia item 8 score of ≥4 or baseline anhedonia subscale score of ≥18. Least square (LS) mean change from baseline to Week 6 was analyzed using a mixed-effects model for repeated measures.
Results
There were 751 patients in the mITT population (CAR + ADT: 1.5 mg/d=250, 3 mg/d=252; placebo + ADT=249). At baseline, 508 (67.6%) patients had MADRS anhedonia item 8 scores ≥4, and 584 (77.8%) had MADRS anhedonia subscale scores ≥18. In the overall mITT population, LS mean change from baseline to Week 6 in anhedonia subscale score was significantly greater for CAR 1.5 mg/d + ADT (-8.4) and CAR 3 mg/d + ADT (-7.9) than for placebo + ADT (-6.8; both P<.05). The LS mean change from baseline in MADRS individual item 8 was also significantly greater for CAR 1.5 mg/d + ADT (-1.7) vs placebo + ADT (-1.3; P=.0085). In both subgroups of patients with baseline anhedonia, CAR 1.5 mg/d + ADT was associated with significantly greater reduction in MADRS total score, MADRS anhedonia subscale score, and MADRS item 8 score compared with placebo + ADT (all P<.05). In the CAR 3 mg/d + ADT group, significantly greater reductions vs placebo + ADT were observed for MADRS total score and MADRS anhedonia subscale score in the subgroup of patients with baseline anhedonia subscale scores ≥18 (both P<.05).
Importance
Adjunctive treatment with CAR was associated with a reduction in symptoms of anhedonia relative to adjunctive placebo in patients with MDD and inadequate response to ADT alone. In subgroups of patients with moderate-to-severe anhedonia at baseline, CAR + ADT demonstrated greater improvements than placebo + ADT in overall depressive symptoms and symptoms of anhedonia. These results suggest that adjunctive CAR treatment may be effective for improving symptoms of anhedonia in patients with MDD who have symptoms of anhedonia.
Inappropriate diagnosis and treatment of urinary tract infections (UTIs) contribute to antibiotic overuse. The Inappropriate Diagnosis of UTI (ID-UTI) measure uses a standard definition of asymptomatic bacteriuria (ASB) and was validated in large hospitals. Critical access hospitals (CAHs) have different resources which may make ASB stewardship challenging. To address this inequity, we adapted the ID-UTI metric for use in CAHs and assessed the adapted measure’s feasibility, validity, and reliability.
Design:
Retrospective observational study
Participants:
10 CAHs
Methods:
From October 2022 to July 2023, CAHs submitted clinical information for adults admitted or discharged from the emergency department who received antibiotics for a positive urine culture. Feasibility of case submission was assessed as the number of CAHs achieving the goal of 59 cases. Validity (sensitivity/specificity) and reliability of the ID-UTI definition were assessed by dual-physician review of a random sample of submitted cases.
Results:
Among 10 CAHs able to participate throughout the study period, only 40% (4/10) submitted >59 cases (goal); an additional 3 submitted >35 cases (secondary goal). Per the ID-UTI metric, 28% (16/58) of cases were ASB. Compared to physician review, the ID-UTI metric had 100% specificity (ie all cases called ASB were ASB on clinical review) but poor sensitivity (48.5%; ie did not identify all ASB cases). Measure reliability was high (93% [54/58] agreement).
Conclusions:
Similar to measure performance in non-CAHs, the ID-UTI measure had high reliability and specificity—all cases identified as ASB were considered ASB—but poor sensitivity. Though feasible for a subset of CAHs, barriers remain.
In response to the COVID-19 pandemic, we rapidly implemented a plasma coordination center, within two months, to support transfusion for two outpatient randomized controlled trials. The center design was based on an investigational drug services model and a Food and Drug Administration-compliant database to manage blood product inventory and trial safety.
Methods:
A core investigational team adapted a cloud-based platform to randomize patient assignments and track inventory distribution of control plasma and high-titer COVID-19 convalescent plasma of different blood groups from 29 donor collection centers directly to blood banks serving 26 transfusion sites.
Results:
We performed 1,351 transfusions in 16 months. The transparency of the digital inventory at each site was critical to facilitate qualification, randomization, and overnight shipments of blood group-compatible plasma for transfusions into trial participants. While inventory challenges were heightened with COVID-19 convalescent plasma, the cloud-based system, and the flexible approach of the plasma coordination center staff across the blood bank network enabled decentralized procurement and distribution of investigational products to maintain inventory thresholds and overcome local supply chain restraints at the sites.
Conclusion:
The rapid creation of a plasma coordination center for outpatient transfusions is infrequent in the academic setting. Distributing more than 3,100 plasma units to blood banks charged with managing investigational inventory across the U.S. in a decentralized manner posed operational and regulatory challenges while providing opportunities for the plasma coordination center to contribute to research of global importance. This program can serve as a template in subsequent public health emergencies.
Asymptomatic bacteriuria (ASB) treatment is a common form of antibiotic overuse and diagnostic error. Antibiotic stewardship using the inappropriate diagnosis of urinary tract infection (ID-UTI) measure has reduced ASB treatment in diverse hospitals. However, critical access hospitals (CAHs) have differing resources that could impede stewardship. We aimed to determine if stewardship including the ID-UTI measure could reduce ASB treatment in CAHs.
Methods:
From October 2022 to July 2023, ten CAHs participated in an Intensive Quality Improvement Cohort (IQIC) program including 3 interventions to reduce ASB treatment: 1) learning labs (ie, didactics with shared learning), 2) mentoring, and 3) data-driven performance reports including hospital peer comparison based on the ID-UTI measure. To assess effectiveness of the IQIC program, change in the ID-UTI measure (ie, percentage of patients treated for a UTI who had ASB) was compared to two non-equivalent control outcomes (antibiotic duration and unjustified fluoroquinolone use).
Results:
Ten CAHs abstracted a total of 608 positive urine culture cases. Over the cohort period, the percentage of patients treated for a UTI who had ASB declined (aOR per month = 0.935, 95% CI: 0.873, 1.001, P = 0.055) from 28.4% (range across hospitals, 0%-63%) in the first to 18.6% (range, 0%-33%) in the final month. In contrast, antibiotic duration and unjustified fluoroquinolone use were unchanged (P = 0.768 and 0.567, respectively).
Conclusions:
The IQIC intervention, including learning labs, mentoring, and performance reports using the ID-UTI measure, was associated with a non-significant decrease in treatment of ASB, while control outcomes (duration and unjustified fluoroquinolone use) did not change.
Bioturbation can increase time averaging by downward and upward movements of young and old shells within the entire mixed layer and by accelerating the burial of shells into a sequestration zone (SZ), allowing them to bypass the uppermost taphonomically active zone (TAZ). However, bioturbation can increase shell disintegration concurrently, neutralizing the positive effects of mixing on time averaging. Bioirrigation by oxygenated pore-water promotes carbonate dissolution in the TAZ, and biomixing itself can mill shells weakened by dissolution or microbial maceration, and/or expose them to damage at the sediment–water interface. Here, we fit transition rate matrices to bivalve age–frequency distributions from four sediment cores from the southern California middle shelf (50–75 m) to assess the competing effects of bioturbation on disintegration and time averaging, exploiting a strong gradient in rates of sediment accumulation and bioturbation created by historic wastewater pollution. We find that disintegration covaries positively with mixing at all four sites, in accord with the scenario where bioturbation ultimately fuels carbonate disintegration. Both mixing and disintegration rates decline abruptly at the base of the 20- to 40-cm-thick, age-homogenized surface mixed layer at the three well-bioturbated sites, despite different rates of sediment accumulation. In contrast, mixing and disintegration rates are very low in the upper 25 cm at an effluent site with legacy sediment toxicity, despite recolonization by bioirrigating lucinid bivalves. Assemblages that formed during maximum wastewater emissions vary strongly in time averaging, with millennial scales at the low-sediment accumulation non-effluent sites, a centennial scale at the effluent site where sediment accumulation was high but bioturbation recovered quickly, and a decadal scale at the second high-sedimentation effluent site where bioturbation remained low for decades. Thus, even though disintegration rates covary positively with mixing rates, reducing postmortem shell survival, bioturbation has the net effect of increasing the time averaging of skeletal remains on this warm-temperate siliciclastic shelf.
Contact binaries challenge contemporary stellar astrophysics with respect to their incidence, structure, and evolution. We explore these issues through a detailed study of two bright examples: S Ant and $\varepsilon$ CrA, that permit high-resolution spectroscopy at a relatively good S/N ratio. The availability of high-quality photometry, including data from the TESS satellite as well as Gaia parallaxes, allows us to apply the Russell paradigm to produce reliable up-to-date information on the physical properties of these binaries. As a result, models of their interactive evolution, such as the thermal relaxation oscillator scenario, can be examined. Mass transfer between the components is clearly evidenced, but the variability of the O’Connell effect over relatively short-time scales points to irregularities in the mass transfer or accretion processes. Our findings indicate that S Ant may evolve into an R CMa type Algol, while the low mass ratio of $\varepsilon$ CrA suggests a likely merger of its components in the not-too-distant future.
The incidence of cognitive decline is rising, leading to increased attention on the preventive role of healthy foods on brain function. Previous reviews including primarily observational studies suggested that dietary proteins may improve cognitive performance, but evidence from individual randomised controlled trials (RCT) is less consistent. Therefore, this systematic review examined the long-term effects of dietary proteins from RCT, considering both their amount and type, on cognitive performance (psychomotor speed and attention, executive function, memory and global cognition). Alterations in cerebral blood flow (CBF) – a validated brain vascular function marker – were also considered. A total of 4747 studies were identified through a systematic search, resulting in twenty-three included papers reporting effects on cognitive performance (n = 23) and CBF (n = 3). Improvements were observed in three out of the nine studies that evaluated psychomotor speed which compared a dietary protein intervention with a non-protein or lower-protein control. Of the six beneficial observations on working memory (n = 12), declarative memory (n = 10) and visuospatial memory (n = 10), five were nut interventions from three different trials. Limited studies focusing on global cognition suggested that specific target populations, namely subacute stroke or dementia, may benefit more than healthy individuals from increased dietary protein intake. From the three studies involving CBF, improvements in regional blood flow were associated with most cognitive performance outcomes. The comparative effects of different protein types warrant further investigation. Overall, this review encourages additional research into protein-rich foods or supplements which could potentially prevent or mitigate cognitive decline.