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Nevin Manimala Statistics

Noise-Generating and Imaging Mechanism Inspired Implicit Regularization Learning Network for Low Dose CT Reconstrution

IEEE Trans Med Imaging. 2023 Dec 25;PP. doi: 10.1109/TMI.2023.3347258. Online ahead of print.

ABSTRACT

Low-dose computed tomography (LDCT) helps to reduce radiation risks in CT scanning while maintaining image quality, which involves a consistent pursuit of lower incident rays and higher reconstruction performance. Although deep learning approaches have achieved encouraging success in LDCT reconstruction, most of them treat the task as a general inverse problem in either the image domain or the dual (sinogram and image) domains. Such frameworks have not considered the original noise generation of the projection data and suffer from limited performance improvement for the LDCT task. In this paper, we propose a novel reconstruction model based on noise-generating and imaging mechanism in full-domain, which fully considers the statistical properties of intrinsic noises in LDCT and prior information in sinogram and image domains. To solve the model, we propose an optimization algorithm based on the proximal gradient technique. Specifically, we derive the approximate solutions of the integer programming problem on the projection data theoretically. Instead of hand-crafting the sinogram and image regularizers, we propose to unroll the optimization algorithm to be a deep network. The network implicitly learns the proximal operators of sinogram and image regularizers with two deep neural networks, providing a more interpretable and effective reconstruction procedure. Numerical results demonstrate our proposed method improvements of > 2.9 dB in peak signal to noise ratio, > 1.4% promotion in structural similarity metric, and > 9 HU decrements in root mean square error over current state-of-the-art LDCT methods.

PMID:38145543 | DOI:10.1109/TMI.2023.3347258

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Nevin Manimala Statistics

A Survey on Progressive Visualization

IEEE Trans Vis Comput Graph. 2023 Dec 25;PP. doi: 10.1109/TVCG.2023.3346641. Online ahead of print.

ABSTRACT

Currently, growing data sources and long-running algorithms impede user attention and interaction with visual analytics applications. Progressive visualization (PV) and visual analytics (PVA) alleviate this problem by allowing immediate feedback and interaction with large datasets and complex computations, avoiding waiting for complete results by using partial results improving with time. Yet, creating a progressive visualization requires more effort than a regular visualization but also opens up new possibilities, such as steering the computations towards more relevant parts of the data, thus saving computational resources. However, there is currently no comprehensive overview of the design space for progressive visualization systems. We surveyed the related work of PV and derived a new taxonomy for progressive visualizations by systematically categorizing all PV publications that included visualizations with progressive features. Progressive visualizations can be categorized by well-known visualization taxonomies, but we also found that progressive visualizations can be distinguished by the way they manage their data processing, data domain, and visual update. Furthermore, we identified key properties such as uncertainty, steering, visual stability, and real-time processing that are significantly different with progressive applications. We also collected evaluation methodologies reported by the publications and conclude with statistical findings, research gaps, and open challenges. A continuously updated visual browser of the survey data is available at visualsurvey.net/pva.

PMID:38145517 | DOI:10.1109/TVCG.2023.3346641

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Nevin Manimala Statistics

Evaluating the Impact of an App-Delivered Mindfulness Meditation Program to Reduce Stress and Anxiety During Pregnancy: Pilot Longitudinal Study

JMIR Pediatr Parent. 2023 Dec 25;6:e53933. doi: 10.2196/53933.

ABSTRACT

BACKGROUND: Stress and anxiety during pregnancy are extremely prevalent and are associated with numerous poor outcomes, among the most serious of which are increased rates of preterm birth and low birth weight infants. Research supports that while in-person mindfulness training is effective in reducing pregnancy stress and anxiety, there are barriers limiting accessibility.

OBJECTIVE: The aim of this paper is to determine if mindfulness meditation training with the Headspace app is effective for stress and anxiety reduction during pregnancy.

METHODS: A longitudinal, single-arm trial was implemented with 20 pregnant women who were instructed to practice meditation via the Headspace app twice per day during the month-long trial. Validated scales were used to measure participant’s levels of stress and anxiety pre- and postintervention. Physiological measures reflective of stress (heart rate variability and sleep) were collected via the Oura Ring.

RESULTS: Statistically significant reductions were found in self-reported levels of stress (P=.005), anxiety (P=.01), and pregnancy anxiety (P<.0001). Hierarchical linear modeling revealed a statistically significant reduction in the physiological data reflective of stress in 1 of 6 heart rate variability metrics, the low-frequency power band, which decreased by 13% (P=.006). A total of 65% of study participants (n=13) reported their sleep improved during the trial, and 95% (n=19) stated that learning mindfulness helped with other aspects of their lives. Participant retention was 100%, with 65% of participants (n=13) completing about two-thirds of the intervention, and 50% of participants (n=10) completing ≥95%.

CONCLUSIONS: This study found evidence to support the Headspace app as an effective intervention to aid in stress and anxiety reduction during pregnancy.

PMID:38145479 | DOI:10.2196/53933

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Nevin Manimala Statistics

Effects of healthy aging and mnemonic strategies on verbal memory performance across the adult lifespan: Mediating role of posterior hippocampus

Hippocampus. 2023 Dec 25. doi: 10.1002/hipo.23592. Online ahead of print.

ABSTRACT

In this study, we aimed to understand the contributions of hippocampal anteroposterior subregions (head, body, tail) and subfields (cornu ammonis 1-3 [CA1-3], dentate gyrus [DG], and subiculum [Sub]) and encoding strategies to the age-related verbal memory decline. Healthy participants were administered the California Verbal Learning Test-II to evaluate verbal memory performance and encoding strategies and underwent 4.7 T magnetic resonance imaging brain scan with subsequent hippocampal subregions and subfields manual segmentation. While total hippocampal volume was not associated with verbal memory performance, we found the volumes of the posterior hippocampus (body) and Sub showed significant effects on verbal memory performance. Additionally, the age-related volume decline in hippocampal body volume contributed to lower use of semantic clustering, resulting in lower verbal memory performance. The effect of Sub on verbal memory was statistically independent of encoding strategies. While total CA1-3 and DG volumes did not show direct or indirect effects on verbal memory, exploratory analyses with DG and CA1-3 volumes within the hippocampal body subregion suggested an indirect effect of age-related volumetric reduction on verbal memory performance through semantic clustering. As semantic clustering is sensitive to age-related hippocampal volumetric decline but not to the direct effect of age, further investigation of mechanisms supporting semantic clustering can have implications for early detection of cognitive impairments and decline.

PMID:38145465 | DOI:10.1002/hipo.23592

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Nevin Manimala Statistics

Health care services for older people in COVID-19 pandemic times – A Nordic comparison

Scand J Prim Health Care. 2023 Dec 25:1-11. doi: 10.1080/02813432.2023.2296119. Online ahead of print.

ABSTRACT

OBJECTIVE: To explore the Nordic municipal health and care services’ ability to promote principal goals within care for older people during the COVID-19 pandemic.

DESIGN AND SETTING: Two surveys were conducted among managers of municipal health care services for older people in Denmark, Finland, Norway and Sweden; the first around 6 months into the pandemic (survey 1), and the second around 12 months later (survey 2). Data were analysed through descriptive statistics, and multiple regression (OLS).

SUBJECTS: 1470 (survey 1, 2020) and 745 (survey 2, 2021) managers. 32% in home care, 51% in nursing homes, 17% combined.

RESULTS: In all countries the pandemic seems to have had more negative impact on eldercare services’ ability to promote an active and social life, than on the ability to promote or enhance older people’s mental and physical health. The regression analysis indicates that different factors influence the ability to promote these goals. Managers within nursing homes reported reduced ability to promote mental and physical health and an active social life to a significantly lower degree than managers of home care. The effect of three prevention strategies (lock down, testing, and/or organisational change), were explored. Organisational change (reorganize staff and practice, restrict use of substitutes) tended to impact the units’ ability to promote a social life in a positive direction, while lock down (areas, buffets etc) tended to impact both the ability to promote mental/physical health and a social life in a negative direction.

CONCLUSION: Measures that can improve opportunities for an active and social life during a pandemic should have high priority, particularily within home care.

PMID:38145400 | DOI:10.1080/02813432.2023.2296119

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Nevin Manimala Statistics

Intrafemoral Injection of Human Hematopoietic Stem and Progenitor Cells into Immunocompromised Mice

J Vis Exp. 2023 Dec 8;(202). doi: 10.3791/66315.

ABSTRACT

Hematopoietic stem cells (HSCs) are defined by their lifelong ability to produce all blood cell types. This is operationally tested by transplanting cell populations containing HSCs into syngeneic or immunocompromised mice. The size and multilineage composition of the graft is then measured over time, usually by flow cytometry. Classically, a population containing HSCs is injected into the circulation of the animal, after which the HSCs home to the bone marrow, where they lodge and begin blood production. Alternatively, HSCs and/or progenitor cells (HSPCs) can be placed directly in the bone marrow cavity. This paper describes a protocol for intrafemoral injection of human HSPCs into immunodeficient mice. In short, preconditioned mice are anesthetized, and a small hole is drilled through the knee into the femur using a needle. Using a smaller insulin needle, cells are then injected directly into the same conduit created by the first needle. This method of transplantation can be applied in varied experimental designs, using either mouse or human cells as donor cells. It has been most widely used for xenotransplantation, because in this context, it is thought to provide improved engraftment over intravenous injections, therefore improving statistical power and reducing the number of mice to be used.

PMID:38145377 | DOI:10.3791/66315

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Nevin Manimala Statistics

The ability to inhibit impulses is related to social behavior in long-tailed macaques

Am J Primatol. 2023 Dec 25:e23587. doi: 10.1002/ajp.23587. Online ahead of print.

ABSTRACT

Performance in cognitive tasks has been linked to differences in species’ social organization, yet to understand its function its relationship to within-species variation in behavior should also be explored. One important cognitive capacity, the ability to inhibit impulses, is typically better in egalitarian than despotic primate species and in primate species with strong fission-fusion dynamics. A different line of research indicates that a high ability to inhibit impulses is related to less aggressive behavior and more socio-positive behavior. However, within species the relationship between performance on cognitive inhibition tasks and variation in social behavior remains to be explored. Here we investigate how performance in a typical inhibition task in cognitive research is related to aggressive and socio-positive behavior in despotic long-tailed macaques. Twenty individuals living in two naturalistic mixed-sex groups were tested with the Plexiglass Hole Task. Aggressive behavior and three types of socio-positive behavior (neutral/friendly approaches, socio-positive signaling, and grooming others) among group members were measured. Individuals differed in their ability to inhibit impulses. Individuals that were not good at inhibiting impulses showed higher rates of aggressive behavior, but also more socio-positive signals, whereas inhibition was not related to neutral/friendly approaches and grooming. These results confirm the positive link between impulsiveness and aggression. In addition, the results indicate that some social-positive behavior may be enhanced when inhibition is limited. In this species, benefits potentially derived from aggression and socio-positive signals match a low ability to inhibit impulses, suggesting that a low ability to inhibit impulses may actually be advantageous. To understand differences between species in cognitive skills, understanding the benefits of variation in a cognitive capacity within a species is crucial.

PMID:38145328 | DOI:10.1002/ajp.23587

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Nevin Manimala Statistics

Hepatocellular carcinoma in cirrhotic versus non-cirrhotic liver: Treatment and survival differences in a nationwide cohort

Scand J Surg. 2023 Dec 25:14574969231220179. doi: 10.1177/14574969231220179. Online ahead of print.

ABSTRACT

BACKGROUND AND AIMS: Numerous studies have reported superior outcome for patients with hepatocellular carcinoma (HCC) in non-cirrhotic compared to cirrhotic livers. This cohort study aims to describe the clinical presentation, disease course, treatment approaches, and survival differences in a population-based setting.

METHODS: Data on patients diagnosed with HCC in Sweden between 2008 and 2018 were identified and extracted from the Swedish Liver registry (SweLiv). Descriptive and survival statistics were applied.

RESULTS: Among the 4259 identified patients, 34% had HCC in a non-cirrhotic liver. Cirrhotic patients presented at a younger age (median = 64 vs 74 years, p < 0.001) and with a poorer performance status (Eastern Cooperative Oncology Group (ECOG) = 0-1: 64% vs 69%, p = 0.024). Underlying liver disease was more prevalent among cirrhotic patients (81% vs 19%, p < 0.001). Tumors in non-cirrhotic livers were diagnosed at a more advanced stage (T3-T4: 46% vs 31%) and more frequently with metastatic disease at diagnosis (22% vs 10%, p < 0.001). Tumors were significantly larger in non-cirrhotic livers (median size of largest tumor 7.5 cm) compared to cirrhotic livers (3.5 cm) (p < 0.001). Curative interventions were more commonly intended (45% vs 37%, p < 0.001) and performed (40% vs 31%, p < 0.001) in the cirrhotic vs non-cirrhotic patients. Median survival was 19 months (95% confidence interval (CI) = 18-21 months), in patients with cirrhosis as compared to 13 months in non-cirrhotic patients (95% CI = 11-15) (p < 0.001). In the multivariable Cox regression model, cirrhosis was not an independent predictor of survival, neither among curatively nor palliatively treated patients.

CONCLUSION: These population-based data show that patients with HCC in a cirrhotic liver receive curative treatment to a greater extent and benefit from superior survival compared to those with HCC in a non-cirrhotic liver. The differences in survival are more attributable to patient and tumor characteristics rather than the cirrhotic status itself.

CLINICAL TRIAL REGISTRATION: not applicable. Patient confidentially: not applicable.

PMID:38145321 | DOI:10.1177/14574969231220179

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Nevin Manimala Statistics

Assessing the Benefits and Risks of Amantadine for Irritability and Aggression after Traumatic Brain Injury

PM R. 2023 Dec 25. doi: 10.1002/pmrj.13122. Online ahead of print.

ABSTRACT

OBJECTIVE: To quantify the benefits versus harms of amantadine in the treatment of irritability and aggression following traumatic brain injury.

METHODS: Secondary outcome data from a randomized controlled multi-site trial of amantadine 100 mg twice daily were used to calculate Number-Needed-To-Treat (NNT). Given prior findings of positive clinician-perceived effects and low incidence of adverse events, we hypothesized low Number-Needed-To-Treat for Benefit (NNTB; high benefit) and high Number-Needed-To-Treat for Harm (NNTH; low risk) based on the clinician ratings, supporting the use of amantadine in clinical practice. Specifically, NNTB values were calculated using number of individuals with improvement on the Clinician Global Impressions-Global Improvement scale (GI). NNTB values were computed using number of individuals with worsening on the GI and experiencing serious and any adverse events.

RESULTS: Based on clinician ratings, on average for every 6 patients treated with amantadine rather than placebo, 1 extra patient would be expected to improve (NNTB=6.4; 95% CI: [3.3, 76.8]). More participants in the placebo group worsened than in the amantadine group, but the result was not statistically significant (NNTH=-92.4; 95% CI: [NNTB -32.9 to -infinity to NNTH -19.2]). The amantadine and placebo groups did not differ on the numbers of adverse events experienced during the trial.

CONCLUSION: Clinician ratings suggest modest benefit of amantadine 100mg twice daily with low risk to appropriately selected patients with adequate renal clearance. Thus, amantadine should be considered a treatment option for the experienced brain injury clinician. These data may support treatment decisions when a pharmaceutical agent is being considered to control irritability/aggression. This article is protected by copyright. All rights reserved.

PMID:38145314 | DOI:10.1002/pmrj.13122

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Nevin Manimala Statistics

Depressive symptoms in the entire spectrum of cognitive ageing in Greece: evidence from the Hellenic Longitudinal Investigation of Aging and Diet (HELIAD)

Int J Psychiatry Clin Pract. 2023 Dec 25:1-8. doi: 10.1080/13651501.2023.2296889. Online ahead of print.

ABSTRACT

OBJECTIVES: To study (i) the prevalence of mild and moderate-to-severe depressive symptoms in the entire spectrum of cognitive ageing in Greece and (ii) the relationship between these symptoms and demographic and clinical data.

METHODS: The study was based on the randomly selected cohort of the Hellenic Longitudinal Investigation of Aging and Diet (HELIAD). Depressive symptoms were assessed with the 15-item version of the Geriatric Depression Scale. Participants also received a comprehensive neuropsychological assessment, while the clinical diagnoses of dementia and mild cognitive impairment were established according to international diagnostic criteria. Statistical analyses relied on comparison tests and a logistic (proportional odds) ordinal regression model.

RESULTS: Depressive symptoms were detected in 19.5% of the 1936 study participants, while 11.3% of both people with MCI and dementia had moderate-to-severe depressive symptoms. The regression model revealed that older adults with more severe depressive symptoms were more likely female, cognitively impaired, less educated, were treated with psychotropic medication and lived in Attica versus Thessaly.

CONCLUSIONS: Since depressive symptoms were detected in almost one in five older adults, healthcare professionals in Greece should safeguard the timely detection and effective treatment of such symptoms and the post-diagnostic care of older adults with depression.Key pointsDepressive symptoms are present in approximately 20% of older adults.More than 10% of older individuals with dementia or mild cognitive impairment report moderate-to-severe depressive symptoms.Female sex, lower education, lower cognitive performance, living in urban areas and treatment with psychotropic medication pertain to more severe depressive symptoms in ageing.Timely detection and effective treatment of depressive symptoms are crucial in the clinical practice of the care of older adults.Further research is needed in order to elucidate the complex relationship between depressive symptoms and cognitive impairment in ageing.

PMID:38145312 | DOI:10.1080/13651501.2023.2296889