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Principles of Medicine in Africa combines clinical medicine with a rich understanding of the major environmental and cultural influences on health and disease, providing comprehensive guidance for anyone intending to practise medicine in Africa. Presenting disease in the context of family and culture, the effects of inequality and problems of limited resources are addressed. The authors have a wealth of experience in front line healthcare in Africa and provide practical, evidence-based management guidelines for all the common and less common conditions likely to be encountered. This fifth edition has been thoroughly updated to incorporate the latest research findings and management guidelines and there has been much greater involvement of African physicians in the writing and editorial process. The chapters on cancer and non-communicable diseases have been expanded and new chapters have been added on digital health, critical care in a resource-limited setting, antimicrobial resistance, COVID-19 and other emerging infectious diseases.
The complexity of movement disorders poses challenges for clinical management and research. Functional imaging with PET or SPECT allows in-vivo assessment of the molecular underpinnings of movement disorders, and biomarkers can aid clinical decision making and understanding of pathophysiology, or determine patient eligibility and endpoints in clinical trials. Imaging targets traditionally include functional processes at the molecular level, typically neurotransmitter systems or brain metabolism, and more recently abnormal protein accumulation, a pathologic hallmark of neurodegenerative diseases. Functional neuroimaging provides complementary information to structural neuroimaging (e.g. anatomic MRI), as molecular/functional changes can present in the absence of, prior to, or alongside structural brain changes. Movement disorder specialists should be aware of the indications, advantages and limitations of molecular functional imaging. An overview is given of functional molecular imaging in movement disorders, covering methodologic background information, typical molecular changes in common movement disorders, and emerging topics with potential for greater future importance.
Humans are characterised as cooperative breeders, as not only the parents but also other members of the social group take part in raising offspring. The individuals who invest most in childrearing are usually the more closely related individuals. However, most studies have concentrated on close kin and the effects of more distant kin remain unknown. Here, we investigated the associations of child mortality (<5 years, n = 32,000 children) with the presence of 36 different types of relatives, divided by lineage and sex, in a historical Finnish population. We found that the presence and greater number of several paternal relatives were associated with an increase in child mortality and many of these associations were seen among the wealthiest families, due to inheritance practices and shared resources. The presence of the maternal grandmother was associated with a decrease in child mortality and the most among poorer families, who probably needed the grandmother’s contribution more than the wealthy. Our results bring new insights into the importance of kin and suggest that relatives can provide support or other resources but also compete for limited resources and care. The results give a broader perspective of human family life and increase understanding of the evolution of cooperative breeding.
Accurate diagnosis of bipolar disorder (BPD) is difficult in clinical practice, with an average delay between symptom onset and diagnosis of about 7 years. A depressive episode often precedes the first manic episode, making it difficult to distinguish BPD from unipolar major depressive disorder (MDD).
Aims
We use genome-wide association analyses (GWAS) to identify differential genetic factors and to develop predictors based on polygenic risk scores (PRS) that may aid early differential diagnosis.
Method
Based on individual genotypes from case–control cohorts of BPD and MDD shared through the Psychiatric Genomics Consortium, we compile case–case–control cohorts, applying a careful quality control procedure. In a resulting cohort of 51 149 individuals (15 532 BPD patients, 12 920 MDD patients and 22 697 controls), we perform a variety of GWAS and PRS analyses.
Results
Although our GWAS is not well powered to identify genome-wide significant loci, we find significant chip heritability and demonstrate the ability of the resulting PRS to distinguish BPD from MDD, including BPD cases with depressive onset (BPD-D). We replicate our PRS findings in an independent Danish cohort (iPSYCH 2015, N = 25 966). We observe strong genetic correlation between our case–case GWAS and that of case–control BPD.
Conclusions
We find that MDD and BPD, including BPD-D are genetically distinct. Our findings support that controls, MDD and BPD patients primarily lie on a continuum of genetic risk. Future studies with larger and richer samples will likely yield a better understanding of these findings and enable the development of better genetic predictors distinguishing BPD and, importantly, BPD-D from MDD.
The incidence of facial palsy has been rising worldwide, with recent evidence emerging of links to COVID-19 infection. To date, guidance on cost-effective treatments is limited to medication (prednisolone). In terms of physical therapy, neuromuscular retraining (NMR) to restore balanced facial function has been most widely evaluated, but not in terms of cost effectiveness. The added value of telerehabilitation is unknown.
Methods
A multistage technology assessment was conducted, which included the following:
• a national survey of current therapy pathways in the UK and patients’ and clinicians’ views on the benefits and challenges of telerehabilitation;
• a systematic review of clinical effectiveness trials evaluating facial NMR therapy;
• calculation of long-term morbidity costs (national economic burden) based on incidence, patient recovery profiles, health-related quality of life, and national facial palsy treatment costs (valuation of clinical improvements in monetary terms was provided by a national Delphi panel); and
• evaluation of the cost effectiveness of telerehabilitation (remote monitoring wearables) added to current face-to-face NMR delivery.
Results
Nationally, approximately five percent of patients with facial palsy (17% of unresolved cases) are referred for facial NMR. The long-term economic burden associated with unresolved cases is estimated to range from GBP351 (EUR417) to GBP584 (EUR692) million, indicating substantial savings if long-term recovery can be improved. Medical treatment costs are GBP86.34 (EUR102) million per annual cohort, and physical and psychological therapy costs are GBP643,292 (EUR762,561). Economic modeling showed that telerehabilitation was cost effective, producing a health gain and a cost-saving of GBP468 (EUR555) per patient. If scaled to the national level for all patients who do not recover fully, an annual saving of GBP3.075 (EUR3.65) million is possible.
Conclusions
Economic modeling indicates that NMR could improve patient outcomes and reduce costs. The national survey demonstrated that access to NMR therapy services is limited, so introduction of telerehabilitation could improve access for currently underserved populations. Future clinical trials need to incorporate economic evaluations to help inform decision-making.
Understanding post-stroke spasticity (PSS) treatment in everyday clinical practice may guide improvements in patient care.
Methods:
This was a retrospective cohort study that used population-level administrative data. Adults (aged ≥18 years) who initiated PSS treatment (defined by the first PSS clinic visit, focal botulinum toxin injection, or anti-spasticity medication dispensation [baclofen, dantrolene and tizanidine] with none of these treatments occurring during the 2 years before the stroke) were identified between 2012 and 2019 in Alberta, Canada. Spasticity treatment use, time to treatment start and type of prescribing/treating physician were measured. Descriptive statistics were performed.
Results:
Within the cohort (n = 1,079), the most common PSS treatment was oral baclofen (initial treatment: 60.9%; received on/after the initial treatment date up to March 31, 2020: 69.0%), largely prescribed by primary care physicians (77.6%) and started a median of 348 (IQR 741) days after the stroke. Focal botulinum toxin (23.3%; 37.7%) was largely prescribed by physiatrists (72.2%) and started 311 (IQR 446) days after the stroke; spasticity clinic visits (18.6%; 23.8%) were also common.
Conclusions:
We found evidence of gaps in provision of spasticity management in persons with PSS including overuse of systemic oral baclofen (that has common adverse side effects and lacks evidence of effectiveness in PSS) and potential underuse of focal botulinum toxin injections. Further investigation and strategies should be pursued to improve alignment of PSS treatment with guideline recommendations that in turn will support better outcomes for those with PSS.
Ruth Glacier is situated in the Central Alaska Range, with the Don Sheldon Amphitheater comprising much of its broad accumulation area, directly adjacent to North America's tallest mountain, Denali. From there it funnels through the ‘Great Gorge,’ flanked by steep valley walls reaching over 1500 m. We combine airborne and ground-based radar measurements of ice thickness with satellite-derived surface velocities to constrain ice flux above and below the gorge, and employ a mass conservation approach to estimate the glacier's thickness within the gorge. We measure ice thickness in the amphitheater to reach 950 m, and estimate centerline thickness in the gorge to range from 610 to 960 m. Our estimates are up to two times greater than those suggested by global models, and allow us to confirm that the Great Gorge rivals Hells Canyon as the deepest gorge in North America. We found that the geometry of the gorge prevents radar measurements of ice thickness there since returns from the subglacial valley walls would precede and potentially occlude nadir bed returns. The same may be true of other unmapped mountain glaciers; however, thickness may be determined using appropriately located flux gates where radar sounding is feasible, combined with mass conservation methods.
We aimed to (1) report updated estimates of direct healthcare costs for people living with MS (pwMS), (2) contrast costs to a control population and (3) explore differences between disability levels among pwMS.
Methods:
Administrative data were used to identify adult pwMS (MS cohort) and without (control cohort) in Alberta, Canada; disability level (based on the Expanded Disability Status Scale) among pwMS was estimated. One- and two-part generalized linear models with gamma distribution were used to estimate the incremental direct healthcare cost (2021 $CDN) of MS during a 1-year observation period.
Results:
Adjusting for confounders, the total healthcare cost ratio was higher in the MS cohort (n = 13,089) versus control (n = 150,080) (5.24 [95% CI: 5.08, 5.41]) with a predicted incremental cost of $15,016 (95% CI: $14,497, $15,535) per person-year. Among the MS cohort, total predicted direct healthcare costs were higher with greater disability, $14,430 (95% CI: $13,980, $14,880) to $58,697 ($51,514, $65,879) per person-year in mild and severe disability, respectively. The primary health resource cost component shifted from disease-modifying therapies in mild disability to supportive care in moderate and severe disability.
Conclusion:
Adult pwMS had greater direct healthcare costs than those without. Extrapolating to the population level (where 14,485 adult pwMS were identified in the study), it is estimated that $218 million per year in healthcare costs may be attributable to MS in Alberta. The significantly larger economic impact associated with greater disability underscores the importance of preventing or delaying disease progression and functional impairment in MS.
Diagnostic criteria for major depressive disorder allow for heterogeneous symptom profiles but genetic analysis of major depressive symptoms has the potential to identify clinical and etiological subtypes. There are several challenges to integrating symptom data from genetically informative cohorts, such as sample size differences between clinical and community cohorts and various patterns of missing data.
Methods
We conducted genome-wide association studies of major depressive symptoms in three cohorts that were enriched for participants with a diagnosis of depression (Psychiatric Genomics Consortium, Australian Genetics of Depression Study, Generation Scotland) and three community cohorts who were not recruited on the basis of diagnosis (Avon Longitudinal Study of Parents and Children, Estonian Biobank, and UK Biobank). We fit a series of confirmatory factor models with factors that accounted for how symptom data was sampled and then compared alternative models with different symptom factors.
Results
The best fitting model had a distinct factor for Appetite/Weight symptoms and an additional measurement factor that accounted for the skip-structure in community cohorts (use of Depression and Anhedonia as gating symptoms).
Conclusion
The results show the importance of assessing the directionality of symptoms (such as hypersomnia versus insomnia) and of accounting for study and measurement design when meta-analyzing genetic association data.
GX is a code designed to solve the nonlinear gyrokinetic system for low-frequency turbulence in magnetized plasmas, particularly tokamaks and stellarators. In GX, our primary motivation and target is a fast gyrokinetic solver that can be used for fusion reactor design and optimization along with wide-ranging physics exploration. This has led to several code and algorithm design decisions, specifically chosen to prioritize time to solution. First, we have used a discretization algorithm that is pseudospectral in the entire phase space, including a Laguerre–Hermite pseudospectral formulation of velocity space, which allows for smooth interpolation between coarse gyrofluid-like resolutions and finer conventional gyrokinetic resolutions and efficient evaluation of a model collision operator. Additionally, we have built GX to natively target graphics processors (GPUs), which are among the fastest computational platforms available today. Finally, we have taken advantage of the reactor-relevant limit of small $\rho _*$ by using the radially local flux-tube approach. In this paper we present details about the gyrokinetic system and the numerical algorithms used in GX to solve the system. We then present several numerical benchmarks against established gyrokinetic codes in both tokamak and stellarator magnetic geometries to verify that GX correctly simulates gyrokinetic turbulence in the small $\rho _*$ limit. Moreover, we show that the convergence properties of the Laguerre–Hermite spectral velocity formulation are quite favourable for nonlinear problems of interest. Coupled with GPU acceleration, which we also investigate with scaling studies, this enables GX to be able to produce useful turbulence simulations in minutes on one (or a few) GPUs and higher fidelity results in a few hours using several GPUs. GX is open-source software that is ready for fusion reactor design studies.
Rift propagation, rather than basal melt, drives the destabilization and disintegration of the Thwaites Eastern Ice Shelf. Since 2016, rifts have episodically advanced throughout the central ice-shelf area, with rapid propagation events occurring during austral spring. The ice shelf's speed has increased by ~70% during this period, transitioning from a rate of 1.65 m d−1 in 2019 to 2.85 m d−1 by early 2023 in the central area. The increase in longitudinal strain rates near the grounding zone has led to full-thickness rifts and melange-filled gaps since 2020. A recent sea-ice break out has accelerated retreat at the western calving front, effectively separating the ice shelf from what remained of its northwestern pinning point. Meanwhile, a distributed set of phase-sensitive radar measurements indicates that the basal melting rate is generally small, likely due to a widespread robust ocean stratification beneath the ice–ocean interface that suppresses basal melt despite the presence of substantial oceanic heat at depth. These observations in combination with damage modeling show that, while ocean forcing is responsible for triggering the current West Antarctic ice retreat, the Thwaites Eastern Ice Shelf is experiencing dynamic feedbacks over decadal timescales that are driving ice-shelf disintegration, now independent of basal melt.
Major depressive disorder (MDD) is the leading cause of disability globally, with moderate heritability and well-established socio-environmental risk factors. Genetic studies have been mostly restricted to European settings, with polygenic scores (PGS) demonstrating low portability across diverse global populations.
Methods
This study examines genetic architecture, polygenic prediction, and socio-environmental correlates of MDD in a family-based sample of 10 032 individuals from Nepal with array genotyping data. We used genome-based restricted maximum likelihood to estimate heritability, applied S-LDXR to estimate the cross-ancestry genetic correlation between Nepalese and European samples, and modeled PGS trained on a GWAS meta-analysis of European and East Asian ancestry samples.
Results
We estimated the narrow-sense heritability of lifetime MDD in Nepal to be 0.26 (95% CI 0.18–0.34, p = 8.5 × 10−6). Our analysis was underpowered to estimate the cross-ancestry genetic correlation (rg = 0.26, 95% CI −0.29 to 0.81). MDD risk was associated with higher age (beta = 0.071, 95% CI 0.06–0.08), female sex (beta = 0.160, 95% CI 0.15–0.17), and childhood exposure to potentially traumatic events (beta = 0.050, 95% CI 0.03–0.07), while neither the depression PGS (beta = 0.004, 95% CI −0.004 to 0.01) or its interaction with childhood trauma (beta = 0.007, 95% CI −0.01 to 0.03) were strongly associated with MDD.
Conclusions
Estimates of lifetime MDD heritability in this Nepalese sample were similar to previous European ancestry samples, but PGS trained on European data did not predict MDD in this sample. This may be due to differences in ancestry-linked causal variants, differences in depression phenotyping between the training and target data, or setting-specific environmental factors that modulate genetic effects. Additional research among under-represented global populations will ensure equitable translation of genomic findings.
A suite of granodiorite samples was collected by dredging from depths of about 1000 m from the walls of Carmel and Monterey submarine canyons, Monterey Bay, California. One surface of each of the various granodiorite slabs was weathered and encrusted with marine organisms. The weathering is maximum at the surface and penetrates to a depth of about 20 cm and selectively alters the feldspars to clay. Potassium feldspars are most severely altered. Mineral selective attack, shallow depth of weathering, restriction of biological growth to weathered surfaces, and regional geological setting are interpreted to mean that the samples were broken from bedrock and that this granodiorite probably weathered in the marine environment.
Authigenic clays formed as a result of the submarine weathering of the granodiorite are kaolinite, K-mica, montmorillonite, and halloysite.
These data suggest that the assemblage K-mica, montmorillonite, and kaolinite have a phase join that may lie on or close to the composition of sea water. Furthermore, kaolinite may be unstable in sea water and gradually break up to form halloysite tubes. The possible influence of biologie agents is suggested in the formation of marine halloysite.
Changing practice patterns caused by the pandemic have created an urgent need for guidance in prescribing stimulants using telepsychiatry for attention-deficit hyperactivity disorder (ADHD). A notable spike in the prescribing of stimulants accompanied the suspension of the Ryan Haight Act, allowing the prescribing of stimulants without a face-to-face meeting. Competing forces both for and against prescribing ADHD stimulants by telepsychiatry have emerged, requiring guidelines to balance these factors. On the one hand, factors weighing in favor of increasing the availability of treatment for ADHD via telepsychiatry include enhanced access to care, reduction in the large number of untreated cases, and prevention of the known adverse outcomes of untreated ADHD. On the other hand, factors in favor of limiting telepsychiatry for ADHD include mitigating the possibility of exploiting telepsychiatry for profit or for misuse, abuse, and diversion of stimulants. This Expert Consensus Group has developed numerous specific guidelines and advocates for some flexibility in allowing telepsychiatry evaluations and treatment without an in-person evaluation to continue. These guidelines also recognize the need to give greater scrutiny to certain subpopulations, such as young adults without a prior diagnosis or treatment of ADHD who request immediate-release stimulants, which should increase the suspicion of possible medication diversion, misuse, or abuse. In such cases, nonstimulants, controlled-release stimulants, or psychosocial interventions should be prioritized. We encourage the use of outside informants to support the history, the use of rating scales, and having access to a hybrid model of both in-person and remote treatment.
This article introduces a Human-centred Engineering Design (HcED) practice, which values human aspects. This practice engages deeply into (1) human geometry and motion for specific tasks, (2) product and manufacturing complexities through rapid prototyping, and (3) the broader human task context. This cross-disciplinary method combines ergonomics, AM, sensor applications, and multiple design practices. The framework provides concrete tasks to drive innovative designs in engineering. The study, grounded in design research case studies, led to five new Paralympic Rowing world records.