Arctic sea ice has declined and become thinner and younger (more seasonal) during the last decade. One consequence of this is that the surface energy budget of the Arctic Ocean is changing. While the ...role of surface albedo has been studied intensively, it is still widely unknown how much light penetrates through sea ice into the upper ocean, affecting sea‐ice mass balance, ecosystems, and geochemical processes. Here we present the first large‐scale under‐ice light measurements, operating spectral radiometers on a remotely operated vehicle (ROV) under Arctic sea ice in summer. This data set is used to produce an Arctic‐wide map of light distribution under summer sea ice. Our results show that transmittance through first‐year ice (FYI, 0.11) was almost three times larger than through multi‐year ice (MYI, 0.04), and that this is mostly caused by the larger melt‐pond coverage of FYI (42 vs. 23%). Also energy absorption was 50% larger in FYI than in MYI. Thus, a continuation of the observed sea‐ice changes will increase the amount of light penetrating into the Arctic Ocean, enhancing sea‐ice melt and affecting sea‐ice and upper‐ocean ecosystems.
Key Points
Light penetration into the ocean will increase in a changing Arctic
Transmittance through first‐year ice is 3x larger than through multi‐year ice
Energy absorption is 50% larger in first‐year ice than in multi‐year ice
In the context of quantifying Arctic ice-volume decrease at global scale, the CryoSat-2 satellite was launched in 2010 and is equipped with the Ku band synthetic aperture radar altimeter SIRAL ...(Synthetic Aperture Interferometric Radar Altimeter), which we use to derive sea-ice freeboard defined as the height of the ice surface above the sea level. Accurate CryoSat-2 range measurements over open water and the ice surface of the order of centimetres are necessary to achieve the required accuracy of the freeboard-to-thickness conversion. Besides uncertainties of the actual sea-surface height and limited knowledge of ice and snow properties, the composition of radar backscatter and therefore the interpretation of radar echoes is crucial. This has consequences in the selection of retracker algorithms which are used to track the main scattering horizon and assign a range estimate to each CryoSat-2 measurement. In this study we apply a retracker algorithm with thresholds of 40, 50 and 80% of the first maximum of radar echo power, spanning the range of values used in the current literature. By using the selected retrackers and additionally results from airborne validation measurements, we evaluate the uncertainties of sea-ice freeboard and higher-level products that arise from the choice of the retracker threshold only, independent of the uncertainties related to snow and ice properties. Our study shows that the choice of retracker thresholds does have a significant impact on magnitudes of estimates of sea-ice freeboard and thickness, but that the spatial distributions of these parameters are less affected. Specifically we find mean radar freeboard values of 0.121 m (0.265 m) for the 40% threshold, 0.086 m (0.203 m) for the 50% threshold and 0.024 m (0.092 m) for the 80% threshold, considering first-year ice (multiyear ice) in March 2013. We show that the main source of freeboard and thickness uncertainty results from the choice of the retracker and the unknown penetration of the radar pulse into the snow layer in conjunction with surface roughness effects. These uncertainties can cause a freeboard bias of roughly 0.06–0.12 m. Furthermore we obtain a significant rise of 0.02–0.15 m of freeboard from March 2013 to November 2013 in the area for multiyear sea ice north of Greenland and Canada. Since this is unlikely, it gives rise to the assumption that applying different retracker thresholds depending on seasonal properties of the snow load is necessary in the future.
Abstract
The objective of the current study was to investigate the associations between lifetime classic psychedelic use and cardiometabolic diseases. Using data from the National Survey on Drug Use ...and Health (2005–2014), the present study examined the associations between lifetime classic psychedelic use and two types of cardiometabolic disease: heart disease and diabetes. Respondents who reported having tried a classic psychedelic at least once in their lifetime had lower odds of heart disease in the past year (adjusted odds ratio (aOR) = 0.77 (0.65–0.92), p = .006) and lower odds of diabetes in the past year (adjusted odds ratio (aOR) = 0.88 (0.78–0.99), p = .036). Classic psychedelic use might be beneficial for cardiometabolic health, but more research is needed to investigate potential causal pathways of classic psychedelics on cardiometabolic diseases.
This review assesses the abuse potential of medically-administered psilocybin, following the structure of the 8 factors of the US Controlled Substances Act (CSA). Research suggests the potential ...safety and efficacy of psilocybin in treating cancer-related psychiatric distress and substance use disorders, setting the occasion for this review. A more extensive assessment of abuse potential according to an 8-factor analysis would eventually be required to guide appropriate schedule placement.
Psilocybin, like other 5-HT2A agonist classic psychedelics, has limited reinforcing effects, supporting marginal, transient non-human self-administration. Nonetheless, mushrooms with variable psilocybin content are used illicitly, with a few lifetime use occasions being normative among users. Potential harms include dangerous behavior in unprepared, unsupervised users, and exacerbation of mental illness in those with or predisposed to psychotic disorders. However, scope of use and associated harms are low compared to prototypical abused drugs, and the medical model addresses these concerns with dose control, patient screening, preparation and follow-up, and session supervision in a medical facility.
(1) psilocybin has an abuse potential appropriate for CSA scheduling if approved as medicine; (2) psilocybin can provide therapeutic benefits that may support the development of an approvable New Drug Application (NDA) but further studies are required which this review describes; (3) adverse effects of medical psilocybin are manageable when administered according to risk management approaches; and (4) although further study is required, this review suggests that placement in Schedule IV may be appropriate if a psilocybin-containing medicine is approved.
This article is part of the Special Issue entitled ‘Psychedelics: New Doors, Altered Perceptions’.
•Psilocybin mushrooms have been used for millennia for spiritual and medical purposes.•Animal and human studies indicate low abuse and no physical dependence potential.•Major national surveys indicate low rates of abuse, treatment-seeking and harm.•Psilocybin may provide therapeutic benefits supporting its development as a new drug.•Analysis supports the scheduling of psilocybin no more restrictively than Schedule IV.
Confirming abstinence during smoking cessation clinical trials is critical for determining treatment effectiveness. Several biological methods exist for verifying abstinence (e.g., exhaled carbon ...monoxide CO, cotinine), and while cotinine provides a longer window of detection, it is not easily used in trials involving nicotine replacement therapy. The Society for Research on Nicotine and Tobacco's Subcommittee on Biochemical Verification cite 8-10 parts per million (ppm) for CO as a viable cutoff to determine abstinence; however, recent literature suggests this cutoff is likely too high and may overestimate the efficacy of treatment.
This study examined the relationship between CO and cotinine in a sample of 662 individuals participating in a smoking cessation clinical trial. A receiver operating characteristics curve was calculated to determine the percentage of false positives and false negatives at given CO levels when using cotinine as confirmation of abstinence. Differences were also examined across race and gender.
A CO cutoff of 3 ppm (97.1% correct classification) most accurately distinguished smokers from nonsmokers. This same cutoff was accurate for both racial and gender groups. The standard cutoffs of 8 ppm (14.0% misclassification of smokers as abstainers) and 10 ppm (20.6% misclassification of smokers as abstainers) produced very high false-negative rates and inaccurately identified a large part of the sample as being abstinent when their cotinine test identified them as still smoking.
It is recommended that researchers and clinicians adopt a more stringent CO cutoff in the range of 3-4 ppm when complete abstinence from smoking is the goal.
Hypertension is the primary risk factor for cardiovascular disease that constitutes a serious worldwide health concern and a significant healthcare burden. As the majority of hypertension has an ...unknown etiology, considerable research efforts in both experimental models and human cohorts has focused on the premise that alterations in the fetal and perinatal environment are key factors in the development of hypertension in children and adults. The exact mechanisms of how fetal programming events increase the risk of hypertension and cardiovascular disease are not fully elaborated; however, the focus on alterations in the biochemical components and functional aspects of the renin-angiotensin (Ang) system (RAS) has predominated, particularly activation of the Ang-converting enzyme (ACE)-Ang II-Ang type 1 receptor (AT
R) axis. The emerging view of alternative pathways within the RAS that may functionally antagonize the Ang II axis raise the possibility that programming events also target the non-classical components of the RAS as an additional mechanism contributing to the development and progression of hypertension. In the current review, we evaluate the potential role of the ACE2-Ang-(1-7)-Mas receptor (MasR) axis of the RAS in fetal programming events and cardiovascular and renal dysfunction. Specifically, the review examines the impact of fetal programming on the Ang-(1-7) axis within the circulation, kidney, and brain such that the loss of Ang-(1-7) expression or tone, contributes to the chronic dysregulation of blood pressure (BP) and cardiometabolic disease in the offspring, as well as the influence of sex on potential programming of this pathway.
Abstract As a proposed mediator between stigma-related stressors and negative mental health outcomes, HIV-related shame has been predictive of increased rates of substance use and difficulties ...adhering to antiretroviral treatment among people with HIV. These downstream manifestations have ultimately impeded progress toward national goals to End the HIV Epidemic , in part due to limited success of conventional psychotherapies in addressing HIV-related shame. In a pilot clinical trial (N = 12), receipt of psilocybin-assisted group therapy was associated with a large pre-post decrease in HIV-related shame as measured by the HIV and Abuse Related Shame Inventory, with a median (IQR) change of − 5.5 (− 6.5, − 3.5) points from baseline to 3-months follow-up ( Z = − 2.6, p = 0.009, r = − 0.75). A paradoxical exacerbation of sexual abuse-related shame experienced by two participants following receipt of psilocybin raises critical questions regarding the use of psilocybin therapy among patients with trauma. These preliminary findings carry potential significance for the future of HIV care.
Cervical cancer treatment and care services have remained largely centralized in Zimbabwe thereby entrenching inequities to access amongst patients. The objective of this study was to investigate the ...determinants of access to treatment and care among women with cervical cancer in Harare, Zimbabwe.
A sequential explanatory mixed methods design was used. In phase 1, three surveys (namely community, patient and health worker) were conducted with sample sizes of 143, 134 and 78 participants respectively. Validated structured questionnaires programmed in Android tablet with SurveytoGo software were used for data collection during the surveys. Univariate, bivariate and multivariate logistic regression analyzes were conducted using STATA® version 14 to generate descriptive statistics and identify determinants of access to cervical cancer treatment and care. In phase 2, 16 in-depth interviews, 20 key informant interviews and 6 focus groups were conducted to explain quantitative data. Participants were purposively selected and saturation principle was used to guide sample sizes. Manually generated thematic codes were processed in Dedoose software to produce final outputs for qualitative study.
Knowledge of causes (p = 0.046), perceptions of adequacy of specialists (p < 0.001), locus of control (p = 0.009), service satisfaction (p = 0.022) and walking as a means of reaching nearest health facilities (p < 0.001) were associated with treatment or perceptions of access by healthy women. Perceptions of access to treatment amongst health workers were associated with their basic training institution (p = 0.046), health service quality perceptions (p = 0.035) and electricity supply status in their respective health facilities (p = 0.036).Qualitative findings revealed health system, societal and individual factors as barriers to accessing treatment and palliative care.
There are numerous prevailing multi-dimensional barriers to accessing cervical cancer treatment and palliative care in a low -income setting. The findings of this study revealed that heath system and societal factors were more important than individual level factors. Multi-sectoral approaches are recommended to address all the multifaceted barriers in order to improve cervical cancer treatment and palliative care access for better outcomes in resource-limited contexts.
Previous studies have investigated challenging, difficult, or distressing classic psychedelic experiences, but little is known about the prevalence and associations of such experiences. Using ...nationally representative data of the US adult population (N = 2822), this study examined the prevalence and associations of challenging, difficult, or distressing experiences using classic psychedelics, in a subsample of respondents who reported lifetime classic psychedelic use (n = 613). Of the 613 respondents who reported lifetime classic psychedelic use, the majority of them (59.1 %) had never had a challenging, difficult, or distressing experience using a classic psychedelic, but 8.9 % of respondents reported functional impairment that lasted longer than one day as a result of such experiences. Notably, 2.6 % reported seeking medical, psychiatric, or psychological assistance in the days or weeks following their most challenging, difficult, or distressing classic psychedelic experience. In covariate-adjusted regression models, co-use of lithium, co-use of other mood stabilizers, and six set and setting variables (no preparation, disagreeable physical environment, negative mindset, no psychological support, dose was too large, major life event prior to experience) were associated with the degree of difficulty; and co-use of lithium, co-use of other mood stabilizers, and three set and setting variables (negative mindset, no psychological support, major life event prior to experience) were associated with overall risk of harm. In summary, this study provides insight into the prevalence and associations of challenging, difficult, or distressing classic psychedelic experiences. The findings broadly correspond with findings from previous studies and can inform harm reduction efforts and future experimental research designs.
•Study on the prevalence and associations of challenging, difficult, or distressing classic psychedelic experiences.•Self-reported co-use of certain medications (e.g., lithium) was associated with degree of difficulty and risk of harm.•Various set and setting variables (e.g., no psychological support) were associated with degree of difficulty and risk of harm.
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