To send 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 sending content to .
To send content items to your Kindle, first ensure firstname.lastname@example.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 sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent 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.
Sedentary behaviour is potentially a modifiable risk factor for depression and anxiety disorders, but findings have been inconsistent.
To assess associations of sedentary behavior with depression and anxiety symptoms and estimate the impact of replacing daily time spent in sedentary behaviors with sleep, light, or moderate-to-vigorous physical activity, using novel compositional data analysis methods.
Prospective cohort study in with 60,235 UK Biobank participants (mean age: 56; 56% female). Exposure was baseline daily movement behaviours (accelerometer-assessed sedentary behaviour, physical activity, and self-reported total sleep). Outcomes were depression and anxiety symptoms (Patient Health Questionnaire-9 and Generalised Anxiety Disorders-7) at follow up.
Replacing 60 minutes of sedentary behaviour with light activity, moderate-to-vigorous activity, and sleep was associated with lower depression symptom scores by 1·3% (95%CI, 0·4%-2·1%), 12·5% (95%CI, 11·4%-13·5%), and 7·6% (95%CI, 6·9%-8·4%), and lower odds of depression by 0·95 (95%CI, 0·94-0·96), 0·75 (95%CI, 0·74-0·76), and 0·90 (95%CI, 0·90-0·91) at follow-up. Replacing 60 minutes of sedentary behaviour with moderate-to-vigorous activity and sleep was associated with lower anxiety symptom scores by 6·6% (95%CI, 5·5%-7·6%) and 4·5% (95%CI, 3·7%-5·2%), and lower odds of meeting the threshold for an anxiety disorder by 0·90 (95%CI, 0·89-0·90) and 0·97 (95%CI, 0·96-0·97) at follow-up. However, replacing 60 minutes of sedentary behaviour with light activity was associated with higher anxiety symptom scores by 4·5% (95%CI, 3·7%-5·3%) and higher odds of an anxiety disorder by 1·07 (95%CI, 1·06-1·08).
Sedentary behaviour is a risk factor for increased depression and anxiety symptoms in adults, but different replacement activities differentially influence mental health.
We summarize some of the past year's most important findings within climate change-related research. New research has improved our understanding of Earth's sensitivity to carbon dioxide, finds that permafrost thaw could release more carbon emissions than expected and that the uptake of carbon in tropical ecosystems is weakening. Adverse impacts on human society include increasing water shortages and impacts on mental health. Options for solutions emerge from rethinking economic models, rights-based litigation, strengthened governance systems and a new social contract. The disruption caused by COVID-19 could be seized as an opportunity for positive change, directing economic stimulus towards sustainable investments.
A synthesis is made of ten fields within climate science where there have been significant advances since mid-2019, through an expert elicitation process with broad disciplinary scope. Findings include: (1) a better understanding of equilibrium climate sensitivity; (2) abrupt thaw as an accelerator of carbon release from permafrost; (3) changes to global and regional land carbon sinks; (4) impacts of climate change on water crises, including equity perspectives; (5) adverse effects on mental health from climate change; (6) immediate effects on climate of the COVID-19 pandemic and requirements for recovery packages to deliver on the Paris Agreement; (7) suggested long-term changes to governance and a social contract to address climate change, learning from the current pandemic, (8) updated positive cost–benefit ratio and new perspectives on the potential for green growth in the short- and long-term perspective; (9) urban electrification as a strategy to move towards low-carbon energy systems and (10) rights-based litigation as an increasingly important method to address climate change, with recent clarifications on the legal standing and representation of future generations.
Social media summary
Stronger permafrost thaw, COVID-19 effects and growing mental health impacts among highlights of latest climate science.
Sedentary behaviour is potentially a modifiable risk factor for anxiety disorders, a major source of global disability that typically starts during adolescence. This is the first prospective study of associations between repeated, device-based measures of sedentary behaviour and anxiety symptoms in adolescents.
A UK cohort with 4257 adolescents aged 12 at baseline (56% female). Main exposures were sedentary behaviour and physical activity measured using accelerometers for 7-days at ages 12, 14, and 16. Primary outcome was anxiety symptom scores at age 18 from a Clinical Interview Schedule-Revised. We used adjusted negative binomial regression and iso-temporal substitution methods to analyse the data.
We found a positive association between sedentary behaviour at ages 12, 14, and 16, with anxiety symptoms at age 18, independent of total physical activity volume. Theoretically replacing an hour of daily sedentary behaviour for light activity at ages 12, 14, and 16, was associated with lower anxiety symptoms by age 18 by 15.9% (95% CI 8.7–22.4), 12.1% (95% CI 3.4–20.1), and 14.7% (95% CI 4–24.2), respectively. Whereas, theoretically replacing an hour of sedentary behaviour with moderate-to-vigorous physical activity was not associated with differences in anxiety symptoms. These results were robust to a series of sensitivity analyses.
Sedentary behaviour is a possible risk factor for increasing anxiety symptoms during adolescence, independent of total physical activity volume. Instead of focusing on moderate-to-vigorous activity, replacing daily sedentary behaviour with light activity during adolescence could be a more suitable method of reducing future anxiety symptoms.
While fetal alcohol spectrum disorder (FASD) has primarily been thought of as a neurodevelopmental condition, research is beginning to highlight its ‘whole-body’ implications. Accordingly, the current study sought to provide a snapshot of potential health issues. Caregivers of children (median age of 12 years) with an FASD diagnosis were invited to participate in an online survey. Information relating to sample demographics, FASD status of the child and health outcomes were collected. The prevalence of health conditions reported in the FASD sample was compared against national prevalence data. Multiple linear regression utilising a stepwise approach was used to investigate potential predictors of the number of diagnosed health conditions. Survey data were from an international cohort (n = 197), with the majority of respondents based in Australia (40.2%) or the United States (27.7%). The most commonly reported diagnosed health conditions were eye conditions (44.7%), asthma (34.5%), heart conditions (34.0%) and skin conditions (27.4%). Binomial testing indicated the proportion of children diagnosed with these disorders was generally higher in the current FASD population, compared to national prevalence data. Indicators of metabolic dysfunction including diabetes and obesity were not significantly different compared to national prevalence data. Age of FASD diagnosis, existence of comorbid mental health conditions and the primary caregiver being in paid work were identified as being associated with the prevalence of diagnosed health conditions. Overall, the study has provided an up-to-date snapshot of health problems reported in a sample of children with FASD, confirming their increased risk of adverse health outcomes.
Changed spatial configurations at sowing have been investigated as a strategy to minimize interspecific competition and improve the establishment and persistence of multi-species plantings in pastures, but the impact of this practice on the soil microbiome has received almost no previous research attention. Differences in populations of bacteria and fungi in the surface 10 cm of soil in the third year following pasture establishment were quantified using quantitative polymerase chain reaction and terminal restriction fragment length polymorphism methods. Populations were compared on, and between, drill rows sown to either the perennial grass phalaris (Phalaris aquatica L.), perennial legume lucerne (alfalfa; Medicago sativa L.) or the annual legume subterranean clover (Trifolium subterraneum L.). Results showed that soil microbial abundance and diversity were related to plant distribution across the field at the time of sampling and to soil chemical parameters including total carbon (C), mineral nitrogen (N), pH, and available phosphorus (P), potassium (K) and sulfur (S). Despite the 27-month lag since sowing, pasture species remained concentrated around the original drill row with very little colonization of the inter-row area. The abundance and diversity of bacterial and fungal populations were consistently greater under drill rows associated with higher total C concentrations in the surface soil compared with the inter-row areas. Our results showed that the pH and available nutrients were similar between the subterranean clover drill row and the inter-row, suggesting that soil microbial populations were not impacted directly by these soil fertility parameters, but rather were related to the presence or absence of plants. The abundance of bacteria and fungi were numerically lower under phalaris rows compared to rows sown to legumes. The richness and diversity of fungal populations were lowest between rows where lucerne was planted. Possible explanations for this observation include a lower C:N ratio of lucerne roots and/or a lack of fibrous roots at the soil surface compared to the other species, illustrating the influence of contrasting plant types on the soil microflora community. This study highlights the enduring legacy of the drill row on the spatial distribution of plants well into the pasture phase of a cropping rotation and discusses the opportunity to enhance the microbiome of cropping soils on a large scale during the pasture phase by increasing plant distribution across the landscape.
Increasing evidence indicates that gut microbiota may influence colorectal cancer risk. Diet, particularly fibre intake, may modify gut microbiota composition, which may affect cancer risk. We investigated the relationship between dietary fibre intake and gut microbiota in adults. Using 16S rRNA gene sequencing, we assessed gut microbiota in faecal samples from 151 adults in two independent study populations: National Cancer Institute (NCI), n 75, and New York University (NYU), n 76. We calculated energy-adjusted fibre intake based on FFQ. For each study population with adjustment for age, sex, race, BMI and smoking, we evaluated the relationship between fibre intake and gut microbiota community composition and taxon abundance. Total fibre intake was significantly associated with overall microbial community composition in NYU (P=0·008) but not in NCI (P=0·81). In a meta-analysis of both study populations, higher fibre intake tended to be associated with genera of class Clostridia, including higher abundance of SMB53 (fold change (FC)=1·04, P=0·04), Lachnospira (FC=1·03, P=0·05) and Faecalibacterium (FC=1·03, P=0·06), and lower abundance of Actinomyces (FC=0·95, P=0·002), Odoribacter (FC=0·95, P=0·03) and Oscillospira (FC=0·96, P=0·06). A species-level meta-analysis showed that higher fibre intake was marginally associated with greater abundance of Faecalibacterium prausnitzii (FC=1·03, P=0·07) and lower abundance of Eubacterium dolichum (FC=0·96, P=0·04) and Bacteroides uniformis (FC=0·97, P=0·05). Thus, dietary fibre intake may impact gut microbiota composition, particularly class Clostridia, and may favour putatively beneficial bacteria such as F. prausnitzii. These findings warrant further understanding of diet–microbiota relationships for future development of colorectal cancer prevention strategies.
Introduction: In 2016, the Emergency Department (ED) Return Visit Quality Program (RVQP) was developed to promote a culture of quality in Ontario EDs, by mandating large-volume EDs to audit charts of patients who had a return visit leading to hospital admission (RV). This program provides an opportunity to identify possible adverse events (AEs) and quality issues, which can then be addressed to improve patient care. Methods: The RVQP requires EDs to audit a set number of 72-hour RVs for potential AEs/quality issues, as well as all 7-day RVs for one of three key paired sentinel diagnoses (acute myocardial infarction, subarachnoid hemorrhage, and pediatric sepsis). Submitted audits and their AEs/quality issues were analyzed by a team of emergency physicians with quality improvement (QI) expertise, and qualitative metrics were derived. Using the general inductive method, we conducted a qualitative analysis with Health Quality Ontario (HQO), and HQO completed an independent analysis of the submitted narrative reports. Our objective is to report on the qualitative and quantitative metrics of the program, and to explore emerging themes from the AEs/quality issues identified. Results: There were 36,304 72-hour RVs flagged, which represent 0.99% of all 3,672,708 ED visits in the province of Ontario for the 86 EDs participating in the first year of the program. Overall, 2,584 audits were conducted. For the audits involving all-cause 72-hour RVs, 571 (24%) of cases had AEs/quality issues identified. Of the 219 audits involving sentinel diagnoses, 107 (49%) audits identified AEs/quality issues. The qualitative analysis revealed 11 themes, which were classified into three groups : issues related to patient characteristics or actions (elder care, patient risk profile, left without being seen); issues related to actions or processes of the ED team (physician cognitive lapses, handover/communication, high risk medications, documentation, radiology, vital signs); and healthcare system issues (imaging/test availability, discharge planning). Over one hundred local QI projects were completed or planned as a result of the audits performed. Conclusion: The RVQP promotes a culture of quality by highlighting potential AEs and quality themes that can then be targeted to increase patient safety and quality of care in Ontario EDs. Numerous QI projects were undertaken in the first year of the program, and future efforts will monitor the completion and success of these. The program can be easily adapted in other jurisdictions.
A study was conducted to evaluate the response of glyphosate- and dicamba-tolerant (GDT) soybean and weed control from cover crop different termination intervals before and after soybean planting. Cover crop biomass was highest when terminated at planting, decreased with the 7- and 14-d preplant (DPP) and day-after-planting (DAP) timings, and again at the 14 DPP and DAP timings. Glyphosate+dicamba provided total control of cover crops by 21 DAP. Cover crop termination timing did not influence soybean population or yield. Palmer amaranth control at the 21 and 28 d after termination (DAT) was 97% to 99%. Differences in Palmer amaranth control were not detected among herbicide programs or termination intervals at the end of season rating, and all treatments provided ≥97% control. Although differences in Palmer amaranth control were not apparent at the end of the season, the delay in cover crop affected the number of days until 10-cm Palmer amaranth was present. When utilizing a wheat+hairy vetch cover crop in DGT soybeans, producers should delay cover crop termination until 11 to 14 DPP and make at least one POST application of glyphosate+dicamba+an additional herbicide mode of action (MOA) to maximize Palmer amaranth control and soybean yields.
Bipolar disorder and schizophrenia are associated with increased mortality relative to the general population. There is an international emphasis on decreasing this excess mortality.
To determine whether the mortality gap between individuals with bipolar disorder and schizophrenia and the general population has decreased.
A nationally representative cohort study using primary care electronic health records from 2000 to 2014, comparing all patients diagnosed with bipolar disorder or schizophrenia and the general population. The primary outcome was all-cause mortality.
Individuals with bipolar disorder and schizophrenia had elevated mortality (adjusted hazard ratio (HR) = 1.79, 95% CI 1.67–1.88 and 2.08, 95% CI 1.98–2.19 respectively). Adjusted HRs for bipolar disorder increased by 0.14/year (95% CI 0.10–0.19) from 2006 to 2014. The adjusted HRs for schizophrenia increased gradually from 2004 to 2010 (0.11/year, 95% CI 0.04–0.17) and rapidly after 2010 (0.34/year, 95% CI 0.18–0.49).
The mortality gap between individuals with bipolar disorder and schizophrenia, and the general population is widening.
Higher carbohydrate intake, glycaemic index (GI), and glycaemic load (GL) are hypothesised to increase cancer risk through metabolic dysregulation of the glucose-insulin axis and adiposity-related mechanisms, but epidemiological evidence is inconsistent. This prospective cohort study investigates carbohydrate quantity and quality in relation to risk of adiposity-related cancers, which represent the most commonly diagnosed preventable cancers in the USA. In exploratory analyses, associations with three site-specific cancers: breast, prostate and colorectal cancers were also examined. The study sample consisted of 3184 adults from the Framingham Offspring cohort. Dietary data were collected in 1991–1995 using a FFQ along with lifestyle and medical information. From 1991 to 2013, 565 incident adiposity-related cancers, including 124 breast, 157 prostate and sixty-eight colorectal cancers, were identified. Cox proportional hazards models were used to evaluate the role of carbohydrate nutrition in cancer risk. GI and GL were not associated with risk of adiposity-related cancers or any of the site-specific cancers. Total carbohydrate intake was not associated with risk of adiposity-related cancers combined or prostate and colorectal cancers. However, carbohydrate consumption in the highest v. lowest quintile was associated with 41 % lower breast cancer risk (hazard ratio (HR) 0·59; 95 % CI 0·36, 0·97). High-, medium- and low-GI foods were not associated with risk of adiposity-related cancers or prostate and colorectal cancers. In exploratory analyses, low-GI foods, were associated with 49 % lower breast cancer risk (HR 0·51; 95 % CI 0·32, 0·83). In this cohort of Caucasian American adults, associations between carbohydrate nutrition and cancer varied by cancer site. Healthier low-GI carbohydrate foods may prevent adiposity-related cancers among women, but these findings require confirmation in a larger sample.
Introduction: Routine auditing of charts of patients with an emergency department (ED) return visit (RV) resulting in hospital admission can uncover quality and safety gaps in care. This feedback can be helpful to clinicians, administrators, and leaders working to improve clinical outcomes, increase patient satisfaction, and promote high-value care. Health Quality Ontario (HQO) has been tasked by Ontario’s Ministry of Health and Long-Term Care (MOHLTC) to manage the newly created ED RV Quality Program (RVQP), which mandates EDs participating in the Pay-for-Results (P4R) program to audit a minimum of 25-50 RVs/year. The goal of the first-ever ED-specific province-wide Quality Improvement (QI) initiative of this kind is to promote a culture of QI that will lead to improved patient care. Methods: Participating hospitals receive quarterly confidential reports from Access to Care (ATC) that show their and other hospitals’ rates of RVs, as well as identifying information for patients meeting RV inclusion criteria at their ED (within 72 hrs of index visit, or within 7 days with specific diagnoses). HQO has partnered with QI experts and ED physician-leaders to develop various guidance materials. These materials have been disseminated through various media. Hospitals are conducting audits to identify underlying quality issues, take steps to address the underlying causes, and submit reports to HQO. A taskforce will then analyze clinical observations, summarize key findings and lessons learned, and share improvements at a provincial level through an annual report. Results: Since its launch in April 2016, 73 P4R and 16 voluntarily enrolled non-P4R hospitals (which collectively receive approximately 90% of ED visits in the province) are participating in the RVQP. ED leaders have engaged their hospital’s leadership to leverage interest and resources to improve patient care in the ED. To date, hospitals have conducted thousands of audits and have identified quality and safety gaps to address, which will be analyzed in February 2017 for reporting shortly thereafter. These will inform QI endeavours locally and provincially, and be the largest source of such data ever created in Ontario. Conclusion: The ED RVQP aims to create a culture of continuous QI in the Ontario health care system, which provides care to over 13.8 million people. Other jurisdictions can replicate this model to promote high-quality care.
Introduction: Analyzing the charts of patients who have a return visit to an emergency department (ED) requiring hospital admission (termed ‘RV’) is an efficient way to identify adverse events (AEs). Investigating these AEs can inform efforts to improve the quality of care provided. The ED RV Quality Program (RVQP) is a new initiative supported by Ontario’s Ministry of Health and Long-Term Care and managed by Health Quality Ontario. It aims to promote a culture of continuous quality improvement through routine audit/investigation of RVs. Methods: The provincial program is mandatory for high-volume EDs and requires auditing of some 72-hour RVs and all 7-day RVs involving ‘sentinel diagnoses’ (subarachnoid hemorrhage [SAH], acute myocardial infarction [AMI], or pediatric sepsis [PS]). A standardized audit template is followed that includes assessment of the type/severity and underlying causes of AEs, and potential actions for improvement. Results: 73 high-volume EDs and 16 smaller EDs (collectively receiving 90% of all ED visits in Ontario) are participating in the program. Nine months’ data have been released to date, comprising 33,956 RVs (1.05% of 3,235,751 ED visits). Of these, 233 RVs (0.69%) were for a sentinel diagnosis (SAH=11, AMI=191, PS=31). The most common presenting complaint on the index visit was abdominal pain (18%). The most common discharge diagnosis following RV admission was acute appendicitis (3.8%). Conclusion: The ED RVQP aims to improve the quality of care provided in Ontario’s EDs by requiring hospitals to conduct audits of RVs and plan actions for improvement when quality gaps are identified. Participating hospitals have completed hundreds of audits to date.
Persistent pain is common and inadequately treated in cancer patients. Behavioral pain interventions are a recommended part of multimodal pain treatments, but they are underused in clinical care due to barriers such as a lack of the resources needed to deliver them in person and difficulties coordinating their use with clinical care. Pain coping skills training (PCST) is an evidence-based behavioral pain intervention traditionally delivered in person. Delivering this training via the web would increase access to it by addressing barriers that currently limit its use. We conducted a patient pilot study of an 8-week web-based PCST program to determine the acceptability of this approach to patients and the program features needed to meet their needs. Focus groups with healthcare providers identified strategies for coordinating the use of web-based PCST in clinical care.
Participants included 7 adults with bone pain due to multiple myeloma or metastasized breast or prostate cancer and 12 healthcare providers (4 physicians and 8 advanced practice providers) who treat cancer-related bone pain. Patients completed web-based PCST at home and then took part in an in-depth qualitative interview. Providers attended focus groups led by a trained moderator. Qualitative analyses identified themes in the patient and provider data.
Patients reported strongly favorable responses to web-based PCST and described emotional and physical benefits. They offered suggestions for adapting the approach to better fit their needs and to overcome barriers to completion. Focus groups indicated a need to familiarize healthcare providers with PCST and to address concerns about overburdening patients. Providers would recommend the program to patients they felt could benefit. They suggested applying a broad definition of cancer pain and having various types of providers help coordinate program its use with clinical care.
Significance of results:
Web-based PCST was acceptable to patients and providers. Our findings suggest that patients could benefit from this approach, especially if patient and provider barriers are addressed.
Congenital or early life infection with Toxoplasma gondii has been implicated in schizophrenia aetiology. Childhood cat ownership has been hypothesized as an intermediary marker of T. gondii infection and, by proxy, as a risk factor for later psychosis. Evidence supporting this hypothesis is, however, limited.
We used birth cohort data from the Avon Longitudinal Study of Parents and Children (ALSPAC) to investigate whether cat ownership in pregnancy and childhood (ages 4 and 10 years) was associated with psychotic experiences (PEs) in early (age 13, N = 6705) and late (age 18, N = 4676) adolescence, rated from semi-structured interviews. We used logistic regression to examine associations between cat ownership and PEs, adjusting for several sociodemographic and socioeconomic factors, household characteristics and dog ownership. Missing data were handled via multiple imputation.
Cat ownership during pregnancy was not associated with PEs at age 13 years [adjusted odds ratio (OR) 1.15, 95% confidence interval (CI) 0.97–1.35] or 18 years (OR 1.08, 95% CI 0.86–1.35). Initial univariable evidence that cat ownership at ages 4 and 10 years was associated with PEs at age 13 years did not persist after multivariable adjustment (4 years: OR 1.18, 95% CI 0.94–1.48; 10 years: OR 1.12, 95% CI 0.92–1.36). There was no evidence that childhood cat ownership was associated with PEs at age 18 years.
While pregnant women should continue to avoid handling soiled cat litter, given possible T. gondii exposure, our study strongly indicates that cat ownership in pregnancy or early childhood does not confer an increased risk of later adolescent PEs.
During a mass gathering, some participants may receive health care for injuries or illnesses that occur during the event. In-event first responders provide initial assessment and management at the event. However, when further definitive care is required, municipal ambulance services provide additional assessment, treatment, and transport of participants to acute care settings, such as hospitals. The impact on both ambulance services and hospitals from mass-gathering events is the focus of this literature review.
This literature review aimed to develop an understanding of the impact of mass gatherings on local health services, specifically pertaining to in-event and external health services.
This research used a systematic literature review methodology. Electronic databases were searched to find articles related to the aim of the review. Articles focused on mass-gathering health, provision of in-event health services, ambulance service transportation, and hospital utilization.
Twenty-four studies were identified for inclusion in this review. These studies were all case-study-based and retrospective in design. The majority of studies (n=23) provided details of in-event first responder services. There was variation noted in reporting of the number and type of in-event health professional services at mass gatherings. All articles reported that patients were transported to hospital by the ambulance service. Only nine articles reported on patients presenting to hospital. However, details pertaining to the impact on ambulance and hospital services were not reported.
There is minimal research focusing on the impact of mass gatherings on in-event and external health services, such as ambulance services and hospitals. A recommendation for future mass-gathering research and evaluation is to link patient-level data from in-event mass gatherings to external health services. This type of study design would provide information regarding the impact on health services from a mass gathering to more accurately inform future health planning for mass gatherings across the health care continuum.
RanseJ, HuttonA, KeeneT, LensonS, LutherM, BostN, JohnstonANB, CrillyJ, CannonM, JonesN, HayesC, BurkeB. Health Service Impact from Mass Gatherings: A Systematic Literature Review. Prehosp Disaster Med. 2017;32(1):71–77.
We studied neuroinflammation in individuals with late-life, depression, as a
risk factor for dementia, using [11C]PK11195 positron emission
tomography (PET). Five older participants with major depression and 13
controls underwent PET and multimodal 3T magnetic resonance imaging (MRI),
with blood taken to measure C-reactive protein (CRP). We found significantly
higher CRP levels in those with late-life depression and raised
[11C]PK11195 binding compared with controls in brain regions
associated with depression, including subgenual anterior cingulate cortex,
and significant hippocampal subfield atrophy in cornu ammonis 1 and
subiculum. Our findings suggest neuroinflammation requires further
investigation in late-life depression, both as a possible aetiological
factor and a potential therapeutic target.
Cover crops are suites of non-marketable plants grown to improve soil tilth and reduce erosion. Despite these agronomic benefits, the use of cover crops is often limited because they do not provide a direct source of revenue for producers. Integrating livestock to graze cover crops could provide both an expeditious method for cover crop termination and an alternative source of revenue. However, there has been little research on the agronomic impacts of grazing for cover crop termination, especially in horticultural market-gardens. We conducted a 3-year study comparing the effects of sheep grazing to terminate a four species cover crop (buckwheat, sweetclover, peas and beets) with those of mowing on soil quality indicators, cover crop termination efficacy, and subsequent cash-crop yields. In addition, we tested the nutritional quality of the cover crop as forage. Compared with mowing, sheep grazing did not affect soil chemistry, temperature or moisture. Our study demonstrates that sheep grazing removed more cover crop biomass than mowing at termination. The assessment of nutritional indices suggests that the four-species cover crop mixture could provide high-quality forage with a potential value of US$144.00–481.80 ha−1 of direct revenue as a grazing lease. Cash-crop yields did not differ between previously grazed and previously mowed plots in the subsequent growing season. We conclude that integrating sheep grazing into market vegetable garden operations could make cover crops more economically viable without having adverse effects on subsequent cash crops.
A field experiment was established to test the impact on crop yield, total productivity and biological di-nitrogen (N2) fixation of a self-regenerating annual legume, subterranean clover (Trifolium subterraneum L.), grown in mixtures with experimental perennial wheat lines. Legume content was altered in one intermediate wheatgrass (Thinopyrum intermedium (Host) Barkworth & Dewey) and two wheat (Triticum aestivum L.) × wheatgrass (Th. spp.) hybrid-based stands by sowing the legume in the same drill row as the perennial crop, or in every second or third row, spatially separated from the perennial crop. The hybrid perennial crops were more vigorous than intermediate wheatgrass in year 1, competing strongly and reducing legume biomass over the 2 yr period leading to reduced inputs of fixed nitrogen (N). However, both hybrid crops declined to negligible levels following the first summer with only the intermediate wheatgrass persisting in adequate densities in year 2. Spatially separating the perennial crop from the legume in alternate drill rows increased legume biomass by 32–128% and clover regeneration by 31–195%, and reduced weed incursion by up to 47% compared with where it was sown in mixed rows. However, spatial separation more than halved grain yields in year 2 compared with where the perennial crop was grown in every drill row. This likely reflected changed competition dynamics where the modified spatial configurations at sowing limited the perennial crops’ access to resources. When estimates of the total inputs of fixed N from the clover (5–165 kg N ha−1 in year 2) were compared with the amounts of N removed in grain by the different perennial wheat treatments (10–55 kg N ha−1 in year 1), it appears feasible that a companion legume could fix sufficient N to maintain the N balance of a cropping system producing 1.5–2.0 t grain ha−1 each year. The inclusion of a legume increased total above-ground biomass by up to 142%, particularly in year 2, but this did not translate into increased grain yields. It seems unlikely that a self-regenerating annual legume will be able to effectively coexist among a dense perennial wheat canopy where both species are sown in the same drill row. Further research is required to develop strategies to channel more of the additional resources apparently accessed by the companion legume into grain production.