New perspectives on the ecology of tree structure and tree communities through terrestrial laser scanning

Terrestrial laser scanning (TLS) opens up the possibility of describing the three-dimensional structures of trees in natural environments with unprecedented detail and accuracy. It is already being extensively applied to describe how ecosystem biomass and structure vary between sites, but can also facilitate major advances in developing and testing mechanistic theories of tree form and forest structure, thereby enabling us to understand why trees and forests have the biomass and three-dimensional structure they do. Here we focus on the ecological challenges and benefits of understanding tree form, and highlight some advances related to capturing and describing tree shape that are becoming possible with the advent of TLS. We present examples of ongoing work that applies, or could potentially apply, new TLS measurements to better understand the constraints on optimization of tree form. Theories of resource distribution networks, such as metabolic scaling theory, can be tested and further refined. TLS can also provide new approaches to the scaling of woody surface area and crown area, and thereby better quantify the metabolism of trees. Finally, we demonstrate how we can develop a more mechanistic understanding of the effects of avoidance of wind risk on tree form and maximum size. Over the next few years, TLS promises to deliver both major empirical and conceptual advances in the quantitative understanding of trees and tree-dominated ecosystems, leading to advances in understanding the ecology of why trees and ecosystems look and grow the way they do

New models of health and social care for people in later life: mapping of innovation in services in two regions of the United Kingdom using a mixed method approach

\ua9 The Author(s) 2024.Background: Innovation for reforming health and social care is high on the policy agenda in the United Kingdom in response to the growing needs of an ageing population. However, information about new innovations of care being implemented is sparse. Methods: We mapped innovations for people in later life in two regions, North East England and South East Scotland. Data collection included discussions with stakeholders (n = 51), semi-structured interviews (n = 14) and website searches that focused on technology, evaluation and health inequalities. We analysed qualitative data using framework and thematic analyses. Quantitative data were analysed descriptively. Results: One hundred eleven innovations were identified across the two regions. Interviewees reported a wide range of technologies that had been rapidly introduced during the COVID-19 pandemic and many remained in use. Digital exclusion of certain groups of older people was an ongoing concern. Innovations fell into two groups; system-level ones that aimed to alleviate systems pressures such as preventing hospital (re)admissions, and patient-level ones which sought to enhance health and wellbeing directly. Interviewees were aware of the importance of health inequalities but lacked data to monitor the impact of innovations on these, and evaluation was challenging due to lack of time, training, and support. Quantitative findings revealed that two thirds of innovations (n = 74, 67%) primarily focused on the system level, whilst a third (n = 37, 33%) primarily focused on the patient-level. Overall, over half (n = 65, 59%) of innovations involved technologies although relatively few (n = 12, 11%) utilised advanced technologies. Very few (n = 16, 14%) focused on reducing health inequalities, and only a minority of innovations (n = 43, 39%) had undergone evaluation (most of which were conducted by the service providers themselves). Conclusions: We found a wide range of innovative care services being developed for people in later life, yet alignment with key policy priorities, such as addressing health inequalities, was limited. There was a strong focus on technology, with little consideration for the potential to widen the health inequality gap. The absence of robust evaluation was also a concern as most innovations were implemented without support to monitor effectiveness and/or without plans for sustainability and spread

Early Life Socioeconomic Circumstance and Late Life Brain Hyperintensities : A Population Based Cohort Study

Funding: Image acquisition and image analysis for this study was funded by the Alzheimer's Research Trust (now Alzheimer's Research UK). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Acknowledgments The authors would like to thank the participants of the Aberdeen 1936 Birth Cohort (ABC36), without whom this research would not have been possible.Peer reviewedPublisher PD

Maximum (prior) brain size, not atrophy, correlates with cognition in community-dwelling older people: a cross-sectional neuroimaging study

<p>Abstract</p> <p>Background</p> <p>Brain size is associated with cognitive ability in adulthood (correlation ~ .3), but few studies have investigated the relationship in normal ageing, particularly beyond age 75 years. With age both brain size and fluid-type intelligence decline, and regional atrophy is often suggested as causing decline in specific cognitive abilities. However, an association between brain size and intelligence may be due to the persistence of this relationship from earlier life.</p> <p>Methods</p> <p>We recruited 107 community-dwelling volunteers (29% male) aged 75–81 years for cognitive testing and neuroimaging. We used principal components analysis to derived a 'general cognitive factor' (g) from tests of fluid-type ability. Using semi-automated analysis, we measured whole brain volume, intracranial area (ICA) (an estimate of maximal brain volume), and volume of frontal and temporal lobes, amygdalo-hippocampal complex, and ventricles. Brain atrophy was estimated by correcting WBV for ICA.</p> <p>Results</p> <p>Whole brain volume (WBV) correlated with general cognitive ability (g) (r = .21, P < .05). Statistically significant associations between brain areas and specific cognitive abilities became non-significant when corrected for maximal brain volume (estimated using ICA), i.e. there were no statistically significant associations between atrophy and cognitive ability. The association between WBV and g was largely attenuated (from .21 to .03: i.e. attenuating the variance by 98%) by correcting for ICA. ICA accounted for 6.2% of the variance in g in old age, whereas atrophy accounted for < 1%.</p> <p>Conclusion</p> <p>The association between brain regions and specific cognitive abilities in community dwelling people of older age is due to the life-long association between whole brain size and general cognitive ability, rather than atrophy of specific regions. Researchers and clinicians should therefore be cautious of interpreting global or regional brain atrophy on neuroimaging as contributing to cognitive status in older age without taking into account prior mental ability and brain size.</p

CT and Clinical Predictors of Fatigue at One Month after Stroke

Background: Fatigue is a common and distressing consequence of stroke, and the aetiology of post-stroke fatigue (PSF) is poorly understood. It is unclear whether chronic brain changes [cerebral atrophy and white matter lesions (WML)], stroke lesion location or certain clinical features are related to its development. The aim of this study was to identify, in patients with acute stroke, whether features in different brain regions on routine CT imaging or routinely collected clinical features predicted PSF at 1 month. Methods: In total, 107 patients (62% male) with acute ischaemic or haemorrhagic stroke were assessed for fatigue (Fatigue Assessment Scale), anxiety and depression (Hospital Anxiety and Depression Scale) at 1 month. Admission brain CT was rated using a structured scoring system for (i) severity of atrophy and (ii) severity of WML in different regions of the brain, and (iii) site of acute and previous vascular lesions. Results: Cerebral atrophy of mild or greater severity was present in 84 patients (77.5%) and WML of mild or greater severity was present in 54 patients (50.5%) in at least one of the evaluated brain regions. There was no association between PSF and severity of atrophy or WML, or presence of acute or previous vascular lesions. We used the Oxfordshire Community Stroke Project (OCSP) classification to explore the possible influence of lesion location because a minority of the patients (37.4%) had visible acute lesions. Fatigue scores were higher in patients with clinically diagnosed posterior strokes (p = 0.046), in females (p = 0.05) and in those with higher depression and anxiety scores (&#x03C1; = 0.52; p 2 = 0.254). Stroke subtype (according to the OCSP classification) was marginally predictive (β = 0.17; p = 0.05) and sex was not statistically significant (β = 0.15; p = 0.08). Conclusions: Features on routine post-stroke CT do not appear to associate with fatigue at 1 month. However, clinically diagnosed posterior strokes as well as female gender, anxiety and depression may be linked with fatigue. Therefore, clinical vigilance rather than CT features should be used to predict fatigue early after stroke. Further research is needed in this area to establish whether biological mechanisms underlie the development of PSF

Extreme genetic fragility of the HIV-1 capsid

Genetic robustness, or fragility, is defined as the ability, or lack thereof, of a biological entity to maintain function in the face of mutations. Viruses that replicate via RNA intermediates exhibit high mutation rates, and robustness should be particularly advantageous to them. The capsid (CA) domain of the HIV-1 Gag protein is under strong pressure to conserve functional roles in viral assembly, maturation, uncoating, and nuclear import. However, CA is also under strong immunological pressure to diversify. Therefore, it would be particularly advantageous for CA to evolve genetic robustness. To measure the genetic robustness of HIV-1 CA, we generated a library of single amino acid substitution mutants, encompassing almost half the residues in CA. Strikingly, we found HIV-1 CA to be the most genetically fragile protein that has been analyzed using such an approach, with 70% of mutations yielding replication-defective viruses. Although CA participates in several steps in HIV-1 replication, analysis of conditionally (temperature sensitive) and constitutively non-viable mutants revealed that the biological basis for its genetic fragility was primarily the need to coordinate the accurate and efficient assembly of mature virions. All mutations that exist in naturally occurring HIV-1 subtype B populations at a frequency &gt;3%, and were also present in the mutant library, had fitness levels that were &gt;40% of WT. However, a substantial fraction of mutations with high fitness did not occur in natural populations, suggesting another form of selection pressure limiting variation in vivo. Additionally, known protective CTL epitopes occurred preferentially in domains of the HIV-1 CA that were even more genetically fragile than HIV-1 CA as a whole. The extreme genetic fragility of HIV-1 CA may be one reason why cell-mediated immune responses to Gag correlate with better prognosis in HIV-1 infection, and suggests that CA is a good target for therapy and vaccination strategies

Nutritional risk in hospitalized patients: impact of nutritional status on serum prealbumin

OBJECTIVE: Poor recognition and monitoring of nutritional status is the most important cause of malnutrition in hospitalized patients. The aim of this study was to assess the nutritional status of a group of patients and compare the results with their serum prealbumin levels. METHODS: Ninety-seven patients admitted consecutively to the hospital were enrolled in the study. The risk of malnutrition was assessed according to anthropometric data and the Subjective Global Assessment and Nutrition Risk Screening 2002 tools. The nutritional statuses of the patients were compared with their age, gender, body mass index, medical history, weight loss and routine biochemical analyses, including prealbumin and length of hospital stay. RESULTS: According to the Nutrition Risk Screening 2002, 57% of the patients were malnourished or at risk of malnutrition, correlating well with the Subjective Global Assessment (pOBJETIVO: Falha no reconhecimento e acompanhamento do estado nutricional é a razão mais importante da desnutrição em pacientes hospitalizados. Este estudo objetivou avaliar o estado nutricional dos pacientes e comparar os resultados com os níveis séricos de pré-albumina. MÉTODOS: Foram incluídos 97 pacientes no estudo, internados consecutivamente. O risco de desnutrição foi avaliado de acordo com dados antropométricos e com a Avaliação Subjetiva Global e Triagem de Risco Nutricional 2002. Os estados nutricionais dos pacientes foram comparados com suas idades, sexo, índice de massa corporal, histórico médico, perda de peso e análises bioquímicas, incluindo pré-albumina e tempo de permanência hospitalar. RESULTADOS: De acordo com o Triagem de Risco Nutricional 2002, 57% dos pacientes estavam desnutridos ou em risco de desnutrição, apresentando boa correlação com o Avaliação Subjetiva Global (p<0,001, r=0,700). A análise multivariada mostrou correlações positivas entre desnutrição e idade, perda de peso, malignidade e proteína reativa-C (p=0,046, p=0,001, p=0,04 e p=0,002). Um escore ³3 no Triagem de Risco Nutricional 2002 foi associado à internação prolongada (p<0,001). Houve correlação entre pré-albumina sérica e o estado nutricional, independente do número de doenças crônicas e biomarcadores de inflamação (p=0,01). A sensibilidade, especificidade, valor preditivo positivo, valor preditivo negativo e valor diagnóstico da pré-albumina na avaliação do risco de desnutrição foram de 94%, 32%, 0,67, 0,78 e 69, respectivamente. Após sete dias de suporte nutricional, o risco de desnutrição caiu em 12% (p<0,001) e os níveis séricos de pré-albumina aumentaram em 20% (p=0,003). CONCLUSÃO: Ao invés de refletir o estado nutricional global do paciente, níveis séricos baixos de séricos de pré-albumina podem ser vistos como um sinal de maior risco de desnutrição, exigindo uma avaliação nutricional mais extensa. A análise sérica de pré-albumina pode ser usada para o monitoramento de pacientes recebendo suporte nutricional

The tropical managed forests observatory: a research network addressing the future of tropical logged forests.

While attention on logging in the tropics has been increasing, studies on the long-term effects of silviculture on forest dynamics and ecology remain scare and spatially limited. Indeed, most of our knowledge on tropical forests arises from studies carried out in undisturbed tropical forests. This biasis problematic given that logged and disturbed tropical forests are now covering a larger area thantheso-alled primary forests. A new network of permanent sample plots in logged forests, the Tropical managed Forests Observatory (TmFO), aims to ?ll this gap by providing unprecedented opportunities to examine long-term data on the resilience of logged tropical forests at regional and global scales. TmFO currently includes 24 experimental sites distributed across three tropical regions, with a total of 490 permanent plots and 921 ha of forest inventories