Using Knowledge-Guided Machine Learning To Assess Patterns of Areal Change in Waterbodies across the Contiguous United States.

Lake and reservoir surface areas are an important proxy for freshwater availability. Advancements in machine learning (ML) techniques and increased accessibility of remote sensing data products have enabled the analysis of waterbody surface area dynamics on broad spatial scales. However, interpreting the ML results remains a challenge. While ML provides important tools for identifying patterns, the resultant models do not include mechanisms. Thus, the "black-box" nature of ML techniques often lacks ecological meaning. Using ML, we characterized temporal patterns in lake and reservoir surface area change from 1984 to 2016 for 103,930 waterbodies in the contiguous United States. We then employed knowledge-guided machine learning (KGML) to classify all waterbodies into seven ecologically interpretable groups representing distinct patterns of surface area change over time. Many waterbodies were classified as having "no change" (43%), whereas the remaining 57% of waterbodies fell into other groups representing both linear and nonlinear patterns. This analysis demonstrates the potential of KGML not only for identifying ecologically relevant patterns of change across time but also for unraveling complex processes that underpin those changes.

Global increase in methane production under future warming of lake bottom waters.

Lakes are significant emitters of methane to the atmosphere, and thus are important components of the global methane budget. Methane is typically produced in lake sediments, with the rate of methane production being strongly temperature dependent. Local and regional studies highlight the risk of increasing methane production under future climate change, but a global estimate is not currently available. Here, we project changes in global lake bottom temperatures and sediment methane production rates from 1901 to 2099. By the end of the 21st century, lake bottom temperatures are projected to increase globally, by an average of 0.86-2.60°C under Representative Concentration Pathways (RCPs) 2.6-8.5, with greater warming projected at lower latitudes. This future warming of bottom waters will likely result in an increase in methane production rates of 13%-40% by the end of the century, with many low-latitude lakes experiencing an increase of up to 17 times the historical (1970-1999) global average under RCP 8.5. The projected increase in methane production will likely lead to higher emissions from lakes, although the exact magnitude of the emission increase requires more detailed regional studies.

Phenological shifts in lake stratification under climate change.

One of the most important physical characteristics driving lifecycle events in lakes is stratification. Already subtle variations in the timing of stratification onset and break-up (phenology) are known to have major ecological effects, mainly by determining the availability of light, nutrients, carbon and oxygen to organisms. Despite its ecological importance, historic and future global changes in stratification phenology are unknown. Here, we used a lake-climate model ensemble and long-term observational data, to investigate changes in lake stratification phenology across the Northern Hemisphere from 1901 to 2099. Under the high-greenhouse-gas-emission scenario, stratification will begin 22.0 ± 7.0 days earlier and end 11.3 ± 4.7 days later by the end of this century. It is very likely that this 33.3 ± 11.7 day prolongation in stratification will accelerate lake deoxygenation with subsequent effects on nutrient mineralization and phosphorus release from lake sediments. Further misalignment of lifecycle events, with possible irreversible changes for lake ecosystems, is also likely.

How glycobiology can help us treat and beat the COVID-19 pandemic.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged during the last months of 2019, spreading throughout the world as a highly transmissible infectious illness designated as COVID-19. Vaccines have now appeared, but the challenges in producing sufficient material and distributing them around the world means that effective treatments to limit infection and improve recovery are still urgently needed. This review focuses on the relevance of different glycobiological molecules that could potentially serve as or inspire therapeutic tools during SARS-CoV-2 infection. As such, we highlight the glycobiology of the SARS-CoV-2 infection process, where glycans on viral proteins and on host glycosaminoglycans have critical roles in efficient infection. We also take notice of the glycan-binding proteins involved in the infective capacity of virus and in human defense. In addition, we critically evaluate the glycobiological contribution of candidate drugs for COVID-19 therapy such as glycans for vaccines, anti-glycan antibodies, recombinant lectins, lectin inhibitors, glycosidase inhibitors, polysaccharides, and numerous glycosides, emphasizing some opportunities to repurpose FDA-approved drugs. For the next-generation drugs suggested here, biotechnological engineering of new probes to block the SARS-CoV-2 infection might be based on the essential glycobiological insight on glycosyltransferases, glycans, glycan-binding proteins, and glycosidases related to this pathology.

Evaluation of mental health and occupational stress in Mexican medical residents / Evaluación de la salud mental y el estrés laboral en médicos residentes mexicanos

Abstract Introduction Since mental health disorders are an emerging problem in medical residents, its detection and attention must be a priority. Objetive To compare the frequency of psychopathology in residents according to sociodemographic and clinical characteristics. Method We conducted a cross-sectional study evaluating the presence of psychopathology, as well as sociodemographic and clinical characteristics in 644 residents through online questionnaires. Results Among participants, 55.7% reported a psychiatric disorder at some point and 29.2% a current one; only 41.5% were under treatment. Additionally, 8.1% had attempted suicide, of which 32.4% attempted it during residency. We found that 6.5% of women and 3.3% of men presented "risk of psychopathology," with a higher percentage of men presenting "severe psychopathology." Individuals with "risk of psychopathology" presented significantly higher scores on all of the questionnaires, compared to those with "absence of psychopathology." Discussion and conclusion Residents with occupational stress also presented higher risks of psychopathology, suicide, and substance use. Being under psychiatric treatment significantly improved the scores on the different scales. Because residency is a period that may increase the probability of suffering psychopathology, interventions should be aimed at reducing occupational stress and bringing specialized care.

Resumen Introducción Dado que los trastornos de salud mental son un problema emergente en los médicos residentes, su detección y atención deben ser una prioridad. Objetivo Comparar la frecuencia de psicopatología en médicos residentes de acuerdo con las características clínicas y sociodemográficas. Método Realizamos un estudio transversal donde evaluamos la presencia de psicopatología, así como características clínicas y sociodemográficas en 644 médicos residentes por medio de cuestionarios en línea. Resultados Entre los participantes, el 55.7% reportó haber tenido un trastorno psiquiátrico en algún momento de su vida y el 29.2% al momento del estudio, de los cuales solo el 41.5% estaba bajo tratamiento psiquiátrico. Asimismo, el 8.1% había intentado suicidarse a lo largo de su vida y el 32.4% lo intentó durante la residencia. Encontramos que el 6.5% de las mujeres y el 3.3% de los hombres presentaban "riesgo de psicopatología", y un mayor porcentaje de hombres presentaron "psicopatología grave". Las personas con "riesgo de psicopatología" contaron con puntuaciones significativamente más altas en todos los cuestionarios, en comparación con los individuos con "ausencia de psicopatología". Discusión y conclusión Los residentes con estrés laboral también presentaron mayor riesgo de psicopatología, suicidio y uso de sustancias. Estar bajo tratamiento psiquiátrico mejoró significativamente los puntajes en las diferentes escalas. Debido a que la residencia es un período que puede aumentar la probabilidad de sufrir psicopatología, las intervenciones deben estar dirigidas a reducir el estrés ocupacional y brindar atención especializada.

Core 1 O-N-acetylgalactosamine (O-GalNAc) glycosylation in the human cell nucleus.

Glycosylation is a very frequent post-translational modification in proteins, and the initiation of O-N-acetylgalactosamine (O-GalNAc) glycosylation has been recently described on relevant nuclear proteins. Here we evaluated the nuclear incorporation of a second sugar residue in the biosynthesis pathway of O-GalNAc glycans to yield the terminal core 1 glycan (C1G, Galß3GalNAcαSer/Thr). Using confocal microscopy, enzymatic assay, affinity chromatography, and mass spectrometry, we analyzed intact cells, purified nuclei and soluble nucleoplasms to identify the essential factors for C1G biosynthesis in the cell nucleus. The enzyme C1GalT1 responsible for C1G synthesis was detected inside the nucleus, while catalytic activity of C1Gal-transferase was present in nucleoplasm and purified nuclei. In addition, C1G were detected in the nucleus inside of intact cells, and nuclear proteins exposing C1G were also identified. These evidences represent the first demonstration of core 1 O-GalNAc glycosylation of proteins in the human cell nucleus. These findings reveal a novel post-translational modification on nuclear proteins, with relevant repercussion in epigenetic and chemical biology areas.

Caracterização da prática do aleitamento materno em crianças menores de 2 anos atendidas em creches públicas e filantrópicas no município de São Paulo, SP / Characterization of breastfeeding practice in children less than 2 years old enrolled at public and philanthropic day care centers in São Paulo, SP

Objetivo: Caracterizar a situação de aleitamento materno em crianças menores de 24 meses frequentadoras de creches públicas e filantrópicas. Métodos: Estudo transversal de 211 lactentes matriculados em creches selecionadas segundo o número de crianças e educadores, a ausência de intervenção de educação em saúde anterior, a segurança na execução da pesquisa, a existência de berçários e o atendimento sómente de famílias de baixa renda. Os dados foram obtidos através de questionários realizados com os pais das crianças. Para digitação e análise dos dados, foi utilizados o programa EpiInfo 6.0. Para avaliar a associação entre as variáveis sociodemograficas e a prática do aleitamento materno, utilizou-se o qui-quadrado e o teste exato de Fischer. O nível de significância considerado foi 5 por cento. Resultados: Neste estudo, 6,2 por cento das crianças nunca receberam leite materno. A duração mediana do aleitamento materno foi 120 dias. Das varíaveis analisadas, observou-se que o tipo de parto (cesárea; p=0,047) e a não realização do alojamento conjunto ( p=0,016) forma fatores preditores para o insucesso do aleitamento materno. Os motivos mais alegados pelas mães para interromper a amamentação foram: rejeição da criança, o leite secou e volta ao trabalho. Conclusão: Os fatores influenciadores da prática do aleitamento materno em crianças frequentadoras de creches alertam para a necessidade de mais ações de promoção, proteção e incentivo a esta prática, que dever iniciada a partir do pré-natal