Shannon entropy of brain functional complex networks under the influence of the psychedelic Ayahuasca

The entropic brain hypothesis holds that the key facts concerning psychedelics are partially explained in terms of increased entropy of the brain's functional connectivity. Ayahuasca is a psychedelic beverage of Amazonian indigenous origin with legal status in Brazil in religious and scientific settings. In this context, we use tools and concepts from the theory of complex networks to analyze resting state fMRI data of the brains of human subjects under two distinct conditions: (i) under ordinary waking state and (ii) in an altered state of consciousness induced by ingestion of Ayahuasca. We report an increase in the Shannon entropy of the degree distribution of the networks subsequent to Ayahuasca ingestion. We also find increased local and decreased global network integration. Our results are broadly consistent with the entropic brain hypothesis. Finally, we discuss our findings in the context of descriptions of "mind-expansion" frequently seen in self-reports of users of psychedelic drugs.Comment: 27 pages, 6 figure

Avaliação da fertilidade dos solos e adubação utilizada em algumas lavouras de soja.

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Calagem para soja recomendacao para o Estado do Parana.

Natureza da acidez do solo; Acidez do solo e sua neutralizacao; Resultados e recomendacoes tecnicas.bitstream/item/35343/1/1984-Comunicado-Tecnico.n.28.Calagem-21x28-OK.pd

Adubacao fosfatada e potassica em cultura de soja no Estado do Parana.

No periodo de 1974 a 1977, foram conduzidos varios experimentos de adubacao com a cultura da soja [Glycine max (L.) Merrill], no Estado do Parana, visando: a) estudar o efeito de niveis de adubacao fosfatada e potassica aplicadas no sulco de semeadura; b) determinar classes de resposta da soja em funcao dos teores de fosforo e potassio do solo, indicados pelo metodo de Mehlich. Os resultados evidenciaram: a) melhor resposta a adubacao fosfatada em solos de cultivo recente do que nos de cultivo antigo com a sucesso trigo-soja; comprova-se, assim, a capacidade da soja em aproveitar o fosforo residual de culturas anteriores; b) a adubacao potassica nao promoveu aumentos expressivos na producao de soja. Para os solos com baixos teores de P residual foram estabele-cidas as seguintes faixas de disponibilidade do nutriente, indicadas pelo metodo de Mehlich: muito baixo (inferior a 1,5 ppm), baixo (1,5 - 3,0 ppm), medio (3,0 - 6,5 ppm) e alto (superior 6,5 ppm); o metodo de analise empregado foi ineficiente para a avaliacao da disponibilidade de P residual

Community pharmacies and pharmacists in Brazil: A missed opportunity

The Brazilian National Health System (BR-NHS) is one of the largest public health systems in the world. In 2019 Brazil had 114,352 community pharmacies (76.8% private owned), that represent the first point of access to healthcare in Brazil due to their wide distribution. Unfortunately, from the government's point of view, the main expected activity of private and public community pharmacies is related to dispensing medicines and other health products. Public community pharmacies can be part of a healthcare center or be in a separate location, sometimes without the presence of a pharmacist. Pharmacists working in these separated locations do not have access to patients’ medical records, and they have difficulty in accessing other members of the patient care team. Pharmacists working in public pharmacies located in healthcare centers may have access to patients’ medical records, but pharmacy activities are frequently under other professional’s supervision (e.g., nurses). Private pharmacies are usually open 24/7 with the presence of a pharmacist for 8 hours on business days. Private community pharmacies have a very limited integration in the BR-NHS and pharmacists are the third largest healthcare workforce in Brazil with more than 221,000 registered in the Brazilian Federal Pharmacist Association [CFF - Conselho Federal de Farmácia]. A University degree in pharmacy is the only requirement to entry into the profession, without any proficiency exam for maintenance or career progression. The Brazilian pharmacist's annual income is ranked as the 2nd better-paid profession with an annual average income of € 5502.37 (in 2020). Description of clinical activities for pharmacies by the CFF increased in the recent years, however there is still a long way to effectively implement them into practice

Cultivars to face climate change effects on crops and weeds: a review

International audienceAbstractClimate change is caused by the release of greenhouse gases in the atmosphere. Climate change will impact many activities, but its effects on agricultural production could be acute. Estimates of annual damages in agriculture due to temperature increase or extended periods of drought will be more costly than damages in other activities. Yield losses are caused both by direct effects of climate change on crops and by indirect effects such as increased inputs in crop production for weed control. One possible solution to counteract the effects of climate change is to seek crop cultivars that are adapted to highly variable, extreme climatic conditions and pest changes. Here we review the effects of climate change on crop cultivars and weeds. Biomass increase will augment marketable yield by 8–70 % for C3 cereals, by 20–144 % for cash and vegetable crops, and by 6–35 % for flowers. Such positive effects could however be reduced by decreasing water and nutrient availability. Rising temperature will decrease yields of temperature-sensitive crops such as maize, soybean, wheat, and cotton or specialty crops such as almonds, grapes, berries, citrus, or stone fruits. Rice, which is expected to yield better under increased CO2, will suffer serious yield losses under high temperatures. Drought stress should decrease the production of tomato, soybean, maize, and cotton. Nevertheless, reviews on C4 photosynthesis response to water stress in interaction with CO2 concentration reveal that elevated CO2 concentration lessens the deleterious effect of drought on plant productivity. C3 weeds respond more strongly than C4 types to CO2 increases through biomass and leaf area increases. The positive response of C3 crops to elevated CO2 may make C4 weeds less competitive for C3 crops, whereas C3 weeds in C4 or C3 crops could become a problem, particularly in tropical regions. Temperature increases will mainly affect the distribution of weeds, particularly C4 type, by expanding their geographical range. This will enhance further yield losses and will affect weed management systems negatively. In addition, the expansion of invasive weed species such as itchgrass, cogongrass, and witchweed facilitated by temperature increases will increase the cost for their control. Under water or nutrient shortage scenarios, an r-strategist with characteristics in the order S-C-R, such as Palmer amaranth, large crabgrass, johnsongrass, and spurges, will most probably prevail. Selection of cultivars that secure high yields under climate change but also by competing weeds is of major importance. Traits related with (a) increased root/shoot ratio, (b) vernalization periods, (c) maturity, (d) regulation of node formation and/or internode distance, (e) harvest index variations, and (f) allelopathy merit further investigation. The cumulative effects of selecting a suitable stress tolerator-competitor cultivar will be reflected in reductions of environmental pollution, lower production costs, and sustainable food production

Modulation of serum brain-derived neurotrophic factor by a single dose of ayahuasca : observation from a randomized controlled trial

Serotonergic psychedelics are emerging as potential antidepressant therapeutic tools, as suggested in a recent randomized controlled trial with ayahuasca for treatment-resistant depression. Preclinical and clinical studies have suggested that serum brain-derived neurotrophic factor (BDNF) levels increase after treatment with serotoninergic antidepressants, but the exact role of BDNF as a biomarker for diagnostic and treatment of major depression is still poorly understood. Here we investigated serum BDNF levels in healthy controls (N = 45) and patients with treatment-resistant depression (N = 28) before (baseline) and 48 h after (D2) a single dose of ayahuasca or placebo. In our sample, baseline serum BDNF levels did not predict major depression and the clinical characteristics of the patients did not predict their BDNF levels. However, at baseline, serum cortisol was a predictor of serum BDNF levels, where lower levels of serum BDNF were detected in a subgroup of subjects with hypocortisolemia. Moreover, at baseline we found a negative correlation between BDNF and serum cortisol in volunteers with eucortisolemia. After treatment (D2) we observed higher BDNF levels in both patients and controls that ingested ayahuasca (N = 35) when compared to placebo (N = 34). Furthermore, at D2 just patients treated with ayahuasca (N = 14), and not with placebo (N = 14), presented a significant negative correlation between serum BDNF levels and depressive symptoms. This is the first double-blind randomized placebo-controlled clinical trial that explored the modulation of BDNF in response to a psychedelic in patients with depression. The results suggest a potential link between the observed antidepressant effects of ayahuasca and changes in serum BDNF, which contributes to the emerging view of using psychedelics as an antidepressant. This trial is registered at http://clinicaltrials.gov (NCT02914769)

Changes in cortisol but not in brain-derived neurotrophic factor modulate the association between sleep disturbances and major depression

Sleep disturbance is a symptom consistently found in major depression and is associated with a longer course of illness, reduced response to treatment, increased risk of relapse and recurrence. Chronic insomnia has been associated with changes in cortisol and serum brain-derived neurotrophic factor (BDNF) levels, which in turn are also changed in major depression. Here, we evaluated the relationship between sleep quality, salivary cortisol awakening response (CAR), and serum BDNF levels in patients with sleep disturbance and treatment-resistant major depression (n = 18), and in a control group of healthy subjects with good (n = 21) and poor (n = 18) sleep quality. We observed that the patients had the lowest CAR and sleep duration of all three groups and a higher latency to sleep than the healthy volunteers with a good sleep profile. Besides, low CAR was correlated with more severe depressive symptoms and worse sleep quality. There was no difference in serum BDNF levels between groups with distinct sleep quality. Taken together, our results showed a relationship between changes in CAR and in sleep quality in patients with treatment-resistant depression, which were correlated with the severity of disease, suggesting that cortisol could be a physiological link between sleep disturbance and major depression

Pathophysiology of major depression by clinical stages

The comprehension of the pathophysiology of the major depressive disorder (MDD) is essential to the strengthening of precision psychiatry. In order to determine the relationship between the pathophysiology of the MDD and its clinical progression, analyzed by severity of the depressive symptoms and sleep quality, we conducted a study assessing different peripheral molecular biomarkers, including the levels of plasma C-reactive protein (CRP), serum mature brain-derived neurotrophic factor (mBDNF), serum cortisol (SC), and salivary cortisol awakening response (CAR), of patients with MDD (n = 58) and a control group of healthy volunteers (n = 62). Patients with the first episode of MDD (n = 30) had significantly higher levels of CAR and SC than controls (n = 32) and similar levels of mBDNF of controls. Patients with treatment-resistant depression (TRD, n = 28) presented significantly lower levels of SC and CAR, and higher levels of mBDNF and CRP than controls (n = 30). An increased severity of depressive symptoms and worse sleep quality were correlated with levels low of SC and CAR, and with high levels of mBDNF. These results point out a strong relationship between the stages clinical of MDD and changes in a range of relevant biological markers. This can assist in the development of precision psychiatry and future research on the biological tests for depression