99 research outputs found
Comment on 'Geoengineering with seagrasses: Is credit due where credit is given?'
Over the past decade scientists around the world have sought to estimate the capacity of seagrass meadows to sequester carbon, and thereby understand their role in climate change mitigation. The number of studies reporting on seagrass carbon accumulation rates is still limited, but growing scientific evidence supports the hypothesis that seagrasses have been efficiently locking away CO2 for decades to millennia (e.g. Macreadie et al 2014, Mateo et al 1997, Serrano et al 2012). Johannessen and Macdonald (2016), however, challenge the role of seagrasses as carbon traps, claiming that gains in carbon storage by seagrasses may be \u27illusionary\u27 and that \u27their contribution to the global burial of carbon has not yet been established\u27. The authors warn that misunderstandings of how sediments receive, process and store carbon have led to an overestimation of carbon burial by seagrasses. Here we would like to clarify some of the questions raised by Johannessen and Macdonald (2016), with the aim to promote discussion within the scientific community about the evidence for carbon sequestration by seagrasses with a view to awarding carbon credits
Fatores associados à subestimação do status do peso da criança pelos pais
Objective: The aim of this study was to examine the prevalence of parental misperception of child weight status, and identify socioeconomic, anthropometric, behavioral and dietary factors associated with underestimation. Method: Cross-sectional study. Data was collected in 14 Brazilian private schools. Parents of children aged 2-8 years (n= 976) completed a self-reported questionnaire assessing their perception of their child's weight status, and sociodemographic, anthropometric, behavioral and dietary information. To measure the agreement between parental perception about child weight status and actual child weight status, the Kappa coefficient was estimated, and to investigate associations between parental underestimation and independent variables, chi-squared tests were performed, followed by multiple logistic regression, considering p <= 0.05 for statistical significance. Results: Overall, 48.05% of the parents incorrectly classified their child's weight. Specifically, 45.08% underestimated their child's weight status, with just 3% of parents overestimating. Children with higher body mass index (OR = 2.03p< 0.001) and boys (OR = 1.70p < 0.001) were more likely to have their weight status underestimated by parents. Conclusion: Since awareness of weight problems is essential for prevention and treatment, clinical practitioners should help parents at high risk of misperception to correctly evaluate their child's weight status. (C) 2017 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda.Objetivo: Analisar a prevalência de percepção errônea dos pais sobre o status do peso infantil e identificar fatores socioeconômicos, antropométricos, comportamentais e dietéticos associados à subestimação. Método: Trata-se de um estudo transversal. Os dados foram coletados em 14 escolas particulares brasileiras. Pais de crianças de dois a oito anos de idade (n = 976) preencheram um questionário autoaplicável sobre sua percepção do estado nutricional do seu filho e informações sociodemográficas, antropométricas, comportamentais e dietéticas. Para medir o grau de concordância entre a percepção dos pais do peso do filho e o peso real do filho, estimamos o coeficiente Kappa e investigamos as associações entre subestimação do pai e variáveis independentes, calculamos o qui-quadrado seguido do modelo de regressão logística múltipla considerando p≤0,05 para significância estatística. Resultados: Em geral, 48,05% dos pais classificaram incorretamente o peso de seus filhos; particularmente, 45,08% subestimaram o peso do seu filho e apenas 3% subestimaram o peso infantil. A regressão logística demonstrou que as crianças com maior índice de massa corporal (OR = 2,03; p < 0,001) e os meninos (OR = 1,70; p < 0,001) tinham maior probabilidade de ter seu peso subestimado pelos pais. Conclusão: Médicos clínicos devem concentrar suas intervenções nessas crianças para ajudar os pais a avaliar corretamente o seu peso. A consciência dos pais sobre um problema de peso em crianças é essencial para a prevenção e tratamento da obesidade infantil e estilos de vida saudáveis.CAPESNational Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (OD)Office of the Director, National Institutes of Health (OD)Conselho Nacional de Pesquisa (CNPq)Univ Fed Sao Paulo UNIFESP, Dept Pediat, Disciplina Nutrol, Sao Paulo, SP, BrazilUniv Sao Paulo, Fac Saude Publ, Dept Epidemiol, Sao Paulo, SP, BrazilJohns Hopkins Univ, Sch Med, Dept Psychiat & Behav Sci, Div Child & Adolescent Psychiat, Baltimore, MD 21205 USAUniv Fed Sao Paulo UNIFESP, Dept Pediat, Disciplina Nutrol, Sao Paulo, SP, BrazilNIDDK: R00DK088360NICHD/OH: U54HD070725NIH/OH: U54HD070725Web of Scienc
Carbon sequestration by Australian tidal marshes
Australia's tidal marshes have suffered significant losses but their recently recognised importance in CO2 sequestration is creating opportunities for their protection and restoration. We compiled all available data on soil organic carbon (OC) storage in Australia's tidal marshes (323 cores). OC stocks in the surface 1 m averaged 165.41 (SE 6.96) Mg OC ha-1 (range 14-963 Mg OC ha-1). The mean OC accumulation rate was 0.55 ± 0.02 Mg OC ha-1 yr -1. Geomorphology was the most important predictor of OC stocks, with fluvial sites having twice the stock of OC as seaward sites. Australia's 1.4 million hectares of tidal marshes contain an estimated 212 million tonnes of OC in the surface 1 m, with a potential CO2 -equivalent value of USD28.02 million per annum. This study provides the most comprehensive estimates of tidal marsh blue carbon in Australia, and illustrates their importance in climate change mitigation and adaptation, acting as CO2 sinks and buffering the impacts of rising sea level. We outline potential further development of carbon offset schemes to restore the sequestration capacity and other ecosystem services provided by Australia tidal marshes
Coordination of opposing sex-specific and core muscle groups regulates male tail posture during Caenorhabditis elegans male mating behavior
Background
To survive and reproduce, animals must be able to modify their motor behavior in response to changes in the environment. We studied a complex behavior of Caenorhabditis elegans, male mating behavior, which provided a model for understanding motor behaviors at the genetic, molecular as well as circuit level. C. elegans male mating behavior consists of a series of six sub-steps: response to contact, backing, turning, vulva location, spicule insertion, and sperm transfer. The male tail contains most of the sensory structures required for mating, in addition to the copulatory structures, and thus to carry out the steps of mating behavior, the male must keep his tail in contact with the hermaphrodite. However, because the hermaphrodite does not play an active role in mating and continues moving, the male must modify his tail posture to maintain contact. We provide a better understanding of the molecular and neuro-muscular pathways that regulate male tail posture during mating.
Results
Genetic and laser ablation analysis, in conjunction with behavioral assays were used to determine neurotransmitters, receptors, neurons and muscles required for the regulation of male tail posture. We showed that proper male tail posture is maintained by the coordinated activity of opposing muscle groups that curl the tail ventrally and dorsally. Specifically, acetylcholine regulates both ventral and dorsal curling of the male tail, partially through anthelmintic levamisole-sensitive, nicotinic receptor subunits. Male-specific muscles are required for acetylcholine-driven ventral curling of the male tail but dorsal curling requires the dorsal body wall muscles shared by males and hermaphrodites. Gamma-aminobutyric acid activity is required for both dorsal and ventral acetylcholine-induced curling of the male tail and an inhibitory gamma-aminobutyric acid receptor, UNC-49, prevents over-curling of the male tail during mating, suggesting that cross-inhibition of muscle groups helps maintain proper tail posture.
Conclusion
Our results demonstrated that coordination of opposing sex-specific and core muscle groups, through the activity of multiple neurotransmitters, is required for regulation of male tail posture during mating. We have provided a simple model for regulation of male tail posture that provides a foundation for studies of how genes, molecular pathways, and neural circuits contribute to sensory regulation of this motor behavior
The Staphylococcus aureus cell division protein, DivIC, interacts with the cell wall and controls its biosynthesis
Bacterial cell division is a complex, dynamic process that requires multiple protein components to orchestrate its progression. Many division proteins are highly conserved across bacterial species alluding to a common, basic mechanism. Central to division is a transmembrane trimeric complex involving DivIB, DivIC and FtsL in Gram-positives. Here, we show a distinct, essential role for DivIC in division and survival of Staphylococcus aureus. DivIC spatially regulates peptidoglycan synthesis, and consequently cell wall architecture, by influencing the recruitment to the division septum of the major peptidoglycan synthetases PBP2 and FtsW. Both the function of DivIC and its recruitment to the division site depend on its extracellular domain, which interacts with the cell wall via binding to wall teichoic acids. DivIC facilitates the spatial and temporal coordination of peptidoglycan synthesis with the developing architecture of the septum during cell division. A better understanding of the cell division mechanisms in S. aureus and other pathogenic microorganisms can provide possibilities for the development of new, more effective treatments for bacterial infections
Exploiting Pan Influenza A and Pan Influenza B Pseudotype Libraries for Efficient Vaccine Antigen Selection.
We developed an influenza hemagglutinin (HA) pseudotype library encompassing Influenza A subtypes HA1-18 and Influenza B subtypes (both lineages) to be employed in influenza pseudotype microneutralization (pMN) assays. The pMN is highly sensitive and specific for detecting virus-specific neutralizing antibodies against influenza viruses and can be used to assess antibody functionality in vitro. Here we show the production of these viral HA pseudotypes and their employment as substitutes for wildtype viruses in influenza neutralization assays. We demonstrate their utility in detecting serum responses to vaccination with the ability to evaluate cross-subtype neutralizing responses elicited by specific vaccinating antigens. Our findings may inform further preclinical studies involving immunization dosing regimens in mice and may help in the creation and selection of better antigens for vaccine design. These HA pseudotypes can be harnessed to meet strategic objectives that contribute to the strengthening of global influenza surveillance, expansion of seasonal influenza prevention and control policies, and strengthening pandemic preparedness and response
Clinically Applicable Segmentation of Head and Neck Anatomy for Radiotherapy: Deep Learning Algorithm Development and Validation Study
BACKGROUND: Over half a million individuals are diagnosed with head and neck cancer each year globally. Radiotherapy is an important curative treatment for this disease, but it requires manual time to delineate radiosensitive organs at risk. This planning process can delay treatment while also introducing interoperator variability, resulting in downstream radiation dose differences. Although auto-segmentation algorithms offer a potentially time-saving solution, the challenges in defining, quantifying, and achieving expert performance remain. OBJECTIVE: Adopting a deep learning approach, we aim to demonstrate a 3D U-Net architecture that achieves expert-level performance in delineating 21 distinct head and neck organs at risk commonly segmented in clinical practice. METHODS: The model was trained on a data set of 663 deidentified computed tomography scans acquired in routine clinical practice and with both segmentations taken from clinical practice and segmentations created by experienced radiographers as part of this research, all in accordance with consensus organ at risk definitions. RESULTS: We demonstrated the model's clinical applicability by assessing its performance on a test set of 21 computed tomography scans from clinical practice, each with 21 organs at risk segmented by 2 independent experts. We also introduced surface Dice similarity coefficient, a new metric for the comparison of organ delineation, to quantify the deviation between organ at risk surface contours rather than volumes, better reflecting the clinical task of correcting errors in automated organ segmentations. The model's generalizability was then demonstrated on 2 distinct open-source data sets, reflecting different centers and countries to model training. CONCLUSIONS: Deep learning is an effective and clinically applicable technique for the segmentation of the head and neck anatomy for radiotherapy. With appropriate validation studies and regulatory approvals, this system could improve the efficiency, consistency, and safety of radiotherapy pathways
Bilobalide modulates serotonin-controlled behaviors in the nematode Caenorhabditis elegans
<p>Abstract</p> <p>Background</p> <p>Dysfunctions in the serotonergic system have been implicated in several neurological disorders such as depression. Elderly individuals who have been diagnosed with clinical depression show elevated cases of neurodegenerative diseases. This has led to suggestions that modulating the serotonin (5-HT) system could provide an alternative method to current therapies for alleviating these pathologies. The neuroprotective effects of bilobalide <it>in vitro </it>have been documented. We aim to determine whether bilobalide affects the 5-HT system in the nematode <it>C. elegans</it>. The wild type worms, as well as well-characterized 5-HT mutants, were fed with bilobalide in a range of concentrations, and several 5-HT controlled behaviors were tested.</p> <p>Results</p> <p>We observed that bilobalide significantly inhibited 5-HT-controlled egg-laying behavior in a dose-dependent manner, which was blocked in the 5-HT receptor mutants (<it>ser-4, mod-1</it>), but not in the 5-HT transporter (<it>mod-5</it>) or synthesis (<it>tph-1</it>) mutants. Bilobalide also potentiated a 5-HT-controlled, experience-dependent locomotory behavior, termed the enhanced slowing response in the wild type animals. However, this effect was fully blocked in 5-HT receptor <it>mod-1 </it>and dopamine defective <it>cat-2 </it>mutants, but only partially blocked in <it>ser-4 </it>mutants. We also demonstrated that acetylcholine transmission was inhibited in a transgenic <it>C. elegans </it>strain that constitutively expresses Aβ, and bilobalide did not significantly affect this inhibition.</p> <p>Conclusion</p> <p>These results suggest that bilobalide may modulate specific 5-HT receptor subtypes, which involves interplay with dopamine transmission. Additional studies for the function of bilobalide in neurotransmitter systems could aid in our understanding of its neuroprotective properties.</p
Exploiting Pan Influenza A and Pan Influenza B pseudotype libraries for efficient vaccine antigen selection
We developed an influenza hemagglutinin (HA) pseudotype library encompassing Influenza A subtypes HA1-18 and Influenza B subtypes (both lineages) to be employed in influenza
pseudotype microneutralization (pMN) assays. The pMN is highly sensitive and specific for detecting
virus-specific neutralizing antibodies against influenza viruses and can be used to assess antibody
functionality in vitro. Here we show the production of these viral HA pseudotypes and their employment as substitutes for wildtype viruses in influenza neutralization assays. We demonstrate
their utility in detecting serum responses to vaccination with the ability to evaluate cross-subtype
neutralizing responses elicited by specific vaccinating antigens. Our findings may inform further
preclinical studies involving immunization dosing regimens in mice and may help in the creation
and selection of better antigens for vaccine design. These HA pseudotypes can be harnessed to meet
strategic objectives that contribute to the strengthening of global influenza surveillance, expansion
of seasonal influenza prevention and control policies, and strengthening pandemic preparedness
and response.Bill and Melinda Gates Foundation: Grand Challenges Universal Influenza Vaccines Award;
UK Research and Innovation (UKRI);
EC FETopen (Virofight, Grant 899619);
Department of Science and Technology of South Africa;
UK Department for the Environment, Food and Rural Affairs (Defra);
Scottish and Welsh governments.http://www.mdpi.com/journal/vaccinespm2022Veterinary Tropical Disease
Climate drives the geography of marine consumption by changing predator communities
Este artículo contiene 7 páginas, 3 figuras, 1 tabla.The global distribution of primary production and consumption by
humans (fisheries) is well-documented, but we have no map linking
the central ecological process of consumption within food
webs to temperature and other ecological drivers. Using standardized
assays that span 105° of latitude on four continents, we show
that rates of bait consumption by generalist predators in shallow
marine ecosystems are tightly linked to both temperature and the
composition of consumer assemblages. Unexpectedly, rates of
consumption peaked at midlatitudes (25 to 35°) in both Northern
and Southern Hemispheres across both seagrass and unvegetated
sediment habitats. This pattern contrasts with terrestrial systems,
where biotic interactions reportedly weaken away from the equator,
but it parallels an emerging pattern of a subtropical peak in
marine biodiversity. The higher consumption at midlatitudes was
closely related to the type of consumers present, which explained
rates of consumption better than consumer density, biomass, species
diversity, or habitat. Indeed, the apparent effect of temperature
on consumption was mostly driven by temperature-associated turnover
in consumer community composition. Our findings reinforce
the key influence of climate warming on altered species composition
and highlight its implications for the functioning of Earth’s
ecosystems.We acknowledge funding from the Smithsonian
Institution and the Tula Foundation.Peer reviewe
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