SciCombinator

Discover the most talked about and latest scientific content & concepts.

709

Psilocybin with psychological support is showing promise as a treatment model in psychiatry but its therapeutic mechanisms are poorly understood. Here, cerebral blood flow (CBF) and blood oxygen-level dependent (BOLD) resting-state functional connectivity (RSFC) were measured with functional magnetic resonance imaging (fMRI) before and after treatment with psilocybin (serotonin agonist) for treatment-resistant depression (TRD). Quality pre and post treatment fMRI data were collected from 16 of 19 patients. Decreased depressive symptoms were observed in all 19 patients at 1-week post-treatment and 47% met criteria for response at 5 weeks. Whole-brain analyses revealed post-treatment decreases in CBF in the temporal cortex, including the amygdala. Decreased amygdala CBF correlated with reduced depressive symptoms. Focusing on a priori selected circuitry for RSFC analyses, increased RSFC was observed within the default-mode network (DMN) post-treatment. Increased ventromedial prefrontal cortex-bilateral inferior lateral parietal cortex RSFC was predictive of treatment response at 5-weeks, as was decreased parahippocampal-prefrontal cortex RSFC. These data fill an important knowledge gap regarding the post-treatment brain effects of psilocybin, and are the first in depressed patients. The post-treatment brain changes are different to previously observed acute effects of psilocybin and other ‘psychedelics’ yet were related to clinical outcomes. A ‘reset’ therapeutic mechanism is proposed.

Concepts: Brain, Magnetic resonance imaging, Cerebral cortex, Cerebrum, Hippocampus, Serotonin, Schizophrenia, Major depressive disorder

701

Dogs may be beneficial in reducing cardiovascular risk in their owners by providing social support and motivation for physical activity. We aimed to investigate the association of dog ownership with incident cardiovascular disease (CVD) and death in a register-based prospective nation-wide cohort (n = 3,432,153) with up to 12 years of follow-up. Self-reported health and lifestyle habits were available for 34,202 participants in the Swedish Twin Register. Time-to-event analyses with time-updated covariates were used to calculate hazard ratios (HR) with 95% confidence intervals (CI). In single- and multiple-person households, dog ownership (13.1%) was associated with lower risk of death, HR 0.67 (95% CI, 0.65-0.69) and 0.89 (0.87-0.91), respectively; and CVD death, HR 0.64 (0.59-0.70), and 0.85 (0.81-0.90), respectively. In single-person households, dog ownership was inversely associated with cardiovascular outcomes (HR composite CVD 0.92, 95% CI, 0.89-0.94). Ownership of hunting breed dogs was associated with lowest risk of CVD. Further analysis in the Twin Register could not replicate the reduced risk of CVD or death but also gave no indication of confounding by disability, comorbidities or lifestyle factors. In conclusion, dog ownership appears to be associated with lower risk of CVD in single-person households and lower mortality in the general population.

Concepts: Epidemiology, Disease, Demography, Blood vessel, Cardiovascular disease, Actuarial science, Physical exercise, Dog breed

699

Despite partial success, communication has remained impossible for persons suffering from complete motor paralysis but intact cognitive and emotional processing, a state called complete locked-in state (CLIS). Based on a motor learning theoretical context and on the failure of neuroelectric brain-computer interface (BCI) communication attempts in CLIS, we here report BCI communication using functional near-infrared spectroscopy (fNIRS) and an implicit attentional processing procedure. Four patients suffering from advanced amyotrophic lateral sclerosis (ALS)-two of them in permanent CLIS and two entering the CLIS without reliable means of communication-learned to answer personal questions with known answers and open questions all requiring a “yes” or “no” thought using frontocentral oxygenation changes measured with fNIRS. Three patients completed more than 46 sessions spread over several weeks, and one patient (patient W) completed 20 sessions. Online fNIRS classification of personal questions with known answers and open questions using linear support vector machine (SVM) resulted in an above-chance-level correct response rate over 70%. Electroencephalographic oscillations and electrooculographic signals did not exceed the chance-level threshold for correct communication despite occasional differences between the physiological signals representing a “yes” or “no” response. However, electroencephalogram (EEG) changes in the theta-frequency band correlated with inferior communication performance, probably because of decreased vigilance and attention. If replicated with ALS patients in CLIS, these positive results could indicate the first step towards abolition of complete locked-in states, at least for ALS.

Concepts: Neuroscience, Amyotrophic lateral sclerosis, Electroencephalography, Evoked potential, Electromyography, Answer, Support vector machine, Neurofeedback

686

The built environment (BE) and in particular kitchen environments harbor a remarkable microbial diversity, including pathogens. We analyzed the bacterial microbiome of used kitchen sponges by 454-pyrosequencing of 16S rRNA genes and fluorescence in situ hybridization coupled with confocal laser scanning microscopy (FISH-CLSM). Pyrosequencing showed a relative dominance of Gammaproteobacteria within the sponge microbiota. Five of the ten most abundant OTUs were closely related to risk group 2 (RG2) species, previously detected in the BE and kitchen microbiome. Regular cleaning of sponges, indicated by their users, significantly affected the microbiome structure. Two of the ten dominant OTUs, closely related to the RG2-species Chryseobacterium hominis and Moraxella osloensis, showed significantly greater proportions in regularly sanitized sponges, thereby questioning such sanitation methods in a long term perspective. FISH-CLSM showed an ubiquitous distribution of bacteria within the sponge tissue, concentrating in internal cavities and on sponge surfaces, where biofilm-like structures occurred. Image analysis showed local densities of up to 5.4 * 10(10) cells per cm(3), and confirmed the dominance of Gammaproteobacteria. Our study stresses and visualizes the role of kitchen sponges as microbiological hot spots in the BE, with the capability to collect and spread bacteria with a probable pathogenic potential.

Concepts: Photosynthesis, Archaea, Bacteria, Microbiology, Ribosomal RNA, Pathogen, 16S ribosomal RNA, Microorganism

685

Despite significant advances in the fabrication of bioengineered scaffolds for tissue engineering, delivery of nutrients in complex engineered human tissues remains a challenge. By taking advantage of the similarities in the vascular structure of plant and animal tissues, we developed decellularized plant tissue as a prevascularized scaffold for tissue engineering applications. Perfusion-based decellularization was modified for different plant species, providing different geometries of scaffolding. After decellularization, plant scaffolds remained patent and able to transport microparticles. Plant scaffolds were recellularized with human endothelial cells that colonized the inner surfaces of plant vasculature. Human mesenchymal stem cells and human pluripotent stem cell derived cardiomyocytes adhered to the outer surfaces of plant scaffolds. Cardiomyocytes demonstrated contractile function and calcium handling capabilities over the course of 21 days. These data demonstrate the potential of decellularized plants as scaffolds for tissue engineering, which could ultimately provide a cost-efficient, “green” technology for regenerating large volume vascularized tissue mass.

Concepts: Stem cell, Plant, Mesenchymal stem cell, Bone marrow, Stem cells, Cell biology, Induced pluripotent stem cell, Pluripotency

681

In just over half a century plastic products have revolutionized human society and have infiltrated terrestrial and marine environments in every corner of the globe. The hazard plastic debris poses to biodiversity is well established, but mitigation and planning are often hampered by a lack of quantitative data on accumulation patterns. Here we document the amount of debris and rate of accumulation on Henderson Island, a remote, uninhabited island in the South Pacific. The density of debris was the highest reported anywhere in the world, up to 671.6 items/m(2) (mean ± SD: 239.4 ± 347.3 items/m(2)) on the surface of the beaches. Approximately 68% of debris (up to 4,496.9 pieces/m(2)) on the beach was buried <10 cm in the sediment. An estimated 37.7 million debris items weighing a total of 17.6 tons are currently present on Henderson, with up to 26.8 new items/m accumulating daily. Rarely visited by humans, Henderson Island and other remote islands may be sinks for some of the world's increasing volume of waste.

Concepts: Earth, World, Pacific Ocean, Beach, Island, Archipelago, Artificial island, Desert island

671

 To determine whether patient outcomes differ between general internists who graduated from a medical school outside the United States and those who graduated from a US medical school.

Concepts: Pathology, United States, Physician, Neurology, High school, Pediatrics, Medical school, Internal medicine

643

Objectives To investigate whether outcomes of patients who were admitted to hospital differ between those treated by younger and older physicians.Design Observational study.Setting US acute care hospitals.Participants 20% random sample of Medicare fee-for-service beneficiaries aged ≥65 admitted to hospital with a medical condition in 2011-14 and treated by hospitalist physicians to whom they were assigned based on scheduled work shifts. To assess the generalizability of findings, analyses also included patients treated by general internists including both hospitalists and non-hospitalists.Main outcome measures 30 day mortality and readmissions and costs of care. Results 736 537 admissions managed by 18 854 hospitalist physicians (median age 41) were included. Patients' characteristics were similar across physician ages. After adjustment for characteristics of patients and physicians and hospital fixed effects (effectively comparing physicians within the same hospital), patients' adjusted 30 day mortality rates were 10.8% for physicians aged <40 (95% confidence interval 10.7% to 10.9%), 11.1% for physicians aged 40-49 (11.0% to 11.3%), 11.3% for physicians aged 50-59 (11.1% to 11.5%), and 12.1% for physicians aged ≥60 (11.6% to 12.5%). Among physicians with a high volume of patients, however, there was no association between physician age and patient mortality. Readmissions did not vary with physician age, while costs of care were slightly higher among older physicians. Similar patterns were observed among general internists and in several sensitivity analyses.Conclusions Within the same hospital, patients treated by older physicians had higher mortality than patients cared for by younger physicians, except those physicians treating high volumes of patients.

Concepts: Medicine, Death, Patient, Hospital, Physician, Doctor-patient relationship, Internal medicine, Residency

626

A central aim of the “lighting revolution” (the transition to solid-state lighting technology) is decreased energy consumption. This could be undermined by a rebound effect of increased use in response to lowered cost of light. We use the first-ever calibrated satellite radiometer designed for night lights to show that from 2012 to 2016, Earth’s artificially lit outdoor area grew by 2.2% per year, with a total radiance growth of 1.8% per year. Continuously lit areas brightened at a rate of 2.2% per year. Large differences in national growth rates were observed, with lighting remaining stable or decreasing in only a few countries. These data are not consistent with global scale energy reductions but rather indicate increased light pollution, with corresponding negative consequences for flora, fauna, and human well-being.

Concepts: Light, Sun, Mass, Probability theory, Lighting, Light pollution, Order theory, Energy conservation

614

Recent climate change on the Antarctic Peninsula is well documented [1-5], with warming, alongside increases in precipitation, wind strength, and melt season length [1, 6, 7], driving environmental change [8, 9]. However, meteorological records mostly began in the 1950s, and paleoenvironmental datasets that provide a longer-term context to recent climate change are limited in number and often from single sites [7] and/or discontinuous in time [10, 11]. Here we use moss bank cores from a 600-km transect from Green Island (65.3°S) to Elephant Island (61.1°S) as paleoclimate archives sensitive to regional temperature change, moderated by water availability and surface microclimate [12, 13]. Mosses grow slowly, but cold temperatures minimize decomposition, facilitating multi-proxy analysis of preserved peat [14]. Carbon isotope discrimination (Δ(13)C) in cellulose indicates the favorability of conditions for photosynthesis [15]. Testate amoebae are representative heterotrophs in peatlands [16-18], so their populations are an indicator of microbial productivity [14]. Moss growth and mass accumulation rates represent the balance between growth and decomposition [19]. Analyzing these proxies in five cores at three sites over 150 years reveals increased biological activity over the past ca. 50 years, in response to climate change. We identified significant changepoints in all sites and proxies, suggesting fundamental and widespread changes in the terrestrial biosphere. The regional sensitivity of moss growth to past temperature rises suggests that terrestrial ecosystems will alter rapidly under future warming, leading to major changes in the biology and landscape of this iconic region-an Antarctic greening to parallel well-established observations in the Arctic [20].

Concepts: Plant, Climate, Weather, Temperature, Antarctica, Cold, Peat, Moss