Rapid diversification of grey mangroves (Avicennia marina) driven by geographic isolation and extreme environmental conditions in the Arabian Peninsula.

Biological systems occurring in ecologically heterogeneous and spatially discontinuous habitats provide an ideal opportunity to investigate the relative roles of neutral and selective factors in driving lineage diversification. The grey mangroves (Avicennia marina) of Arabia occur at the northern edge of the species' range and are subject to variable, often extreme, environmental conditions, as well as historic large fluctuations in habitat availability and connectivity resulting from Quaternary glacial cycles. Here, we analyse fully sequenced genomes sampled from 19 locations across the Red Sea, the Arabian Sea and the Persian/Arabian Gulf (PAG) to reconstruct the evolutionary history of the species in the region and to identify adaptive mechanisms of lineage diversification. Population structure and phylogenetic analyses revealed marked genetic structure correlating with geographic distance and highly supported clades among and within the seas surrounding the Arabian Peninsula. Demographic modelling showed times of divergence consistent with recent periods of geographic isolation and low marine connectivity during glaciations, suggesting the presence of (cryptic) glacial refugia in the Red Sea and the PAG. Significant migration was detected within the Red Sea and the PAG, and across the Strait of Hormuz to the Arabian Sea, suggesting gene flow upon secondary contact among populations. Genetic-environment association analyses revealed high levels of adaptive divergence and detected signs of multi-loci local adaptation driven by temperature extremes and hypersalinity. These results support a process of rapid diversification resulting from the combined effects of historical factors and ecological selection and reveal mangrove peripheral environments as relevant drivers of lineage diversity.

Reinforcement of Acrylamide Hydrogels with Cellulose Nanocrystals Using Gamma Radiation for Antibiotic Drug Delivery.

In this paper, we report the synthesis of acrylamide hydrogels (net-AAm) reinforced with cellulose nanocrystals (CNCs) using gamma radiation, a powerful tool to obtain crosslinked polymers without the use of chemical initiators and crosslinking agents. Some slight changes in the chemical structure and crystallinity of CNCs took place during gamma irradiation without affecting the nanofiller function. In fact, cellulose nanocrystals had a notable influence over the swelling and mechanical properties on the reinforced hydrogels (net-AAm/CNC), obtaining more rigid material since the Young compression modulus increased from 11 kPa for unreinforced net-AAm to 30 kPa for net-AAm/CNC (4% w/w). Moreover, the studies of retention and release of ciprofloxacin (Cx), a quinolone antibiotic drug, showed that reinforced hydrogels were able to load large amounts of ciprofloxacin (1.2-2.8 mg g-1) but they distributed 100% of the drug very quickly (<100 min). Despite this, they exhibited better mechanical properties than the control sample, allowing their handling, and could be used as wound dressings of first response because they can absorb the exudate and at the same time deliver an antibiotic drug directly over the injury.

Potential role of seaweeds in climate change mitigation.

Seaweed (macroalgae) has attracted attention globally given its potential for climate change mitigation. A topical and contentious question is: Can seaweeds' contribution to climate change mitigation be enhanced at globally meaningful scales? Here, we provide an overview of the pressing research needs surrounding the potential role of seaweed in climate change mitigation and current scientific consensus via eight key research challenges. There are four categories where seaweed has been suggested to be used for climate change mitigation: 1) protecting and restoring wild seaweed forests with potential climate change mitigation co-benefits; 2) expanding sustainable nearshore seaweed aquaculture with potential climate change mitigation co-benefits; 3) offsetting industrial CO2 emissions using seaweed products for emission abatement; and 4) sinking seaweed into the deep sea to sequester CO2. Uncertainties remain about quantification of the net impact of carbon export from seaweed restoration and seaweed farming sites on atmospheric CO2. Evidence suggests that nearshore seaweed farming contributes to carbon storage in sediments below farm sites, but how scalable is this process? Products from seaweed aquaculture, such as the livestock methane-reducing seaweed Asparagopsis or low carbon food resources show promise for climate change mitigation, yet the carbon footprint and emission abatement potential remains unquantified for most seaweed products. Similarly, purposely cultivating then sinking seaweed biomass in the open ocean raises ecological concerns and the climate change mitigation potential of this concept is poorly constrained. Improving the tracing of seaweed carbon export to ocean sinks is a critical step in seaweed carbon accounting. Despite carbon accounting uncertainties, seaweed provides many other ecosystem services that justify conservation and restoration and the uptake of seaweed aquaculture will contribute to the United Nations Sustainable Development Goals. However, we caution that verified seaweed carbon accounting and associated sustainability thresholds are needed before large-scale investment into climate change mitigation from seaweed projects.

Binary Graft of Poly(N-vinylcaprolactam) and Poly(acrylic acid) onto Chitosan Hydrogels Using Ionizing Radiation for the Retention and Controlled Release of Therapeutic Compounds.

In this study, we carried out the synthesis of a thermo- and pH-sensitive binary graft, based on N-vinylcaprolactam (NVCL) and pH sensitive acrylic acid (AAc) monomers, onto chitosan gels (net-CS) by ionizing radiation. Pre-oxidative irradiation and direct methods were examined, and materials obtained were characterized by FTIR-ATR, thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and swelling tests (equilibrium swelling time, critical pH, and temperature). The best synthesis radiation method was the direct method, which resulted in the maximum grafting percentages (~40%) at low doses (10-12 kGy). The main goal of this study was the comparison of the swelling behavior and physicochemical properties of net-CS with those of the binary system (net-CS)-g-NVCL/AAc with the optimum grafting percentage (~30%). This produced a material that showed an upper critical solution temperature (UCST) of 33.5 °C and a critical pH value of 3.8, indicating the system is more hydrophilic at higher temperatures and low pH values. Load and release studies were carried out using diclofenac. The grafted system (32%) was able to load 19.3 mg g-1 of diclofenac and release about 95% within 200 min, in comparison to net-CS, which only released 80% during the same period. When the grafted system was protonated before diclofenac loading, it loaded 27.6 mg g-1. However, the drug was strongly retained in the material by electrostatic interactions and only released about 20%.

A high-quality genome assembly and annotation of the gray mangrove, Avicennia marina.

The gray mangrove [Avicennia marina (Forsk.) Vierh.] is the most widely distributed mangrove species, ranging throughout the Indo-West Pacific. It presents remarkable levels of geographic variation both in phenotypic traits and habitat, often occupying extreme environments at the edges of its distribution. However, subspecific evolutionary relationships and adaptive mechanisms remain understudied, especially across populations of the West Indian Ocean. High-quality genomic resources accounting for such variability are also sparse. Here we report the first chromosome-level assembly of the genome of A. marina. We used a previously release draft assembly and proximity ligation libraries Chicago and Dovetail HiC for scaffolding, producing a 456,526,188-bp long genome. The largest 32 scaffolds (22.4-10.5 Mb) accounted for 98% of the genome assembly, with the remaining 2% distributed among much shorter 3,759 scaffolds (62.4-1 kb). We annotated 45,032 protein-coding genes using tissue-specific RNA-seq data in combination with de novo gene prediction, from which 34,442 were associated to GO terms. Genome assembly and annotated set of genes yield a 96.7% and 95.1% completeness score, respectively, when compared with the eudicots BUSCO dataset. Furthermore, an FST survey based on resequencing data successfully identified a set of candidate genes potentially involved in local adaptation and revealed patterns of adaptive variability correlating with a temperature gradient in Arabian mangrove populations. Our A. marina genomic assembly provides a highly valuable resource for genome evolution analysis, as well as for identifying functional genes involved in adaptive processes and speciation.

Perception that Mothers and / or Guardians of Overweight or Obese Preschool Children Have of a Text Messaging Program to Support Behaviour Change in their Children.

In most childhood obesity preventive programs, parents are targeted as they are key in achieving lifestyle behavior change in their children. Because their participation is generally low, new technologies, such as text messaging, are being tested to assess if their participation increases. The objective of this study was to determine the perception that mothers of overweight/ obese preschool children have of a textmessaging program developed to support their children's lifestyle behavior change. Text messages were sent to 60 mothers twice a week for 12 weeks; 58 of them said they received all of them. During the process mothers were contacted twice regarding their opinion on all aspects related to the messages. At follow-up, we determined perception by in depth interviews administered to participants. Results show that text messaging implemented in a personalized manner was considered successful in regards to providing useful information to support their children's behavior change.

Translational Molecular Ecology in practice: Linking DNA-based methods to actionable marine environmental management.

Molecular-based approaches can provide timely biodiversity assessments, showing an immense potential to facilitate decision-making in marine environmental management. However, the uptake of molecular data into environmental policy remains minimal. Here, we showcase a selection of local to global scale studies applying molecular-based methodologies for environmental management at various stages of implementation. Drawing upon lessons learned from these case-studies, we provide a roadmap to facilitate applications of DNA-based methods to marine policies and to overcome the existing challenges. The main impediment identified is the need for standardized protocols to guarantee data comparison across spatial and temporal scales. Adoption of Translational Molecular Ecology - the sustained collaboration between molecular ecologists and stakeholders, will enhance consensus with regards to the objectives, methods, and outcomes of environmental management projects. Establishing a sustained dialogue among stakeholders is key to accelerating the adoption of molecular-based approaches for marine monitoring and assessment.

A DNA mini-barcode for marine macrophytes.

Studies focusing on marine macrophyte metabarcoding from environmental samples are scarce, due to the lack of a universal barcode for these taxa, and to their poor representation in DNA databases. Here, we searched for a short barcode able to identify marine macrophytes from tissue samples; then, we created a DNA reference library which was used to identify macrophytes in eDNA from coastal sediments. Barcoding of seagrasses, mangroves and marine macroalgae (Chlorophyta, Rhodophyta and Phaeophyceae) was tested using 18 primer pairs from six barcoding genes: the plant barcodes rbcL, matK and trnL, plus the genes ITS2, COI and 18S. The 18S gene showed the highest universality among marine macrophytes, amplifying 95%-100% of samples; amplification performance of the other barcodes was limited. Taxonomy was assigned using a phylogeny-based approach to create an 18S DNA reference library. Macrophyte tissue sequences were accurately identified within their phyla (88%), order (76%), genus (71%) and species (23%). Nevertheless, out of 86 macrophytes tested, only 48% and 15% had a reference sequence at genus and at species level, respectively. Identification at these levels can be improved by more inclusive reference libraries. Using the 18S mini-barcode and the reference library, we recovered eDNA from 21 marine macrophytes in sediments, demonstrating the barcode's ability to trace primary producers that contribute to blue carbon. We expect this barcode to also be useful for other ecological questions, such as tracing macro primary producers in marine food webs.

Academically Oriented Activity Breaks for First-Grade Chilean Students: Development and Pilot Testing Effectiveness.

We developed and pilot tested the effectiveness of a physically active academic program, Active Breaks (AB), whose objective is to increase school time moderate/vigorous physical activity (MVPA) among first graders, through daily 15-minute bouts of MVPA, at the beginning of the first lesson. Initially, 240 cards including one game each were developed and tested in first-grade students from 16 schools in Santiago. Trained observers and school teachers assessed the time, ease, and feasibility of implementation for each card. Barriers and facilitators to implementation were obtained from semistructured interviews to 14 teachers (out of 16). In eight schools (n = 556 students), we compared school time MVPA (with accelerometers) at baseline and follow-up, using test of proportions. One-hundred and twenty cards (games) complied with all aspects. AB were implemented 50% of the time with a duration of 14 minutes (SD = 5). More than 90% of the time, teachers felt competent to conduct AB, and children understood the instructions and enjoyed the activity. The main facilitators included teachers liking physical activity and considering it important, support of principal and school staff, and conducting AB inside the classroom. Barriers included teacher's workload and having to conduct AB during the first lesson. During the 4-month period of implementation, MVPA increased by 1.5 and 1.2 percentage points in boys and girls, respectively. The set of 120 cards is easy and feasible to implement. Moreover, preliminary results suggest they could be effective in increasing MVPA during school time, although studies with longer follow-ups are needed to assess the validity of these findings.

Perception of humanized childbirth in patients in the puerperium period. / Percepción del parto humanizado en pacientes en periodo de puerperio.

BACKGROUND: The patient's perception of humanized childbirth care is important to identify and avoid data suggestive of obstetric violence, which is all conduct, action or omission, performed by health personnel that affect the body and the reproductive processes of women, expressed in dehumanized treatment. OBJECTIVE: To know the level of perception of humanized childbirth in patients in the postpartum period in the OB-Gyn Service at the Hospital General de Zona No. 1 from the Instituto Mexicano del Seguro Social. MATERIAL AND METHODS: Observational study in 190 patients in the immediate puerperium. Demographic variables were measured and the level of perception of humanized delivery was analyzed (inadequate: 18-32 points; regular: 35-53 points; adequate: 54-72 points). Descriptive statistics and association measures were used. Informed written consent of the participants was signed and authorized with the registration number R-2018-301-020. RESULTS: The overall perception of humanized delivery was inadequate in 56.8%, regular in 34.7% and adequate in 8.4%. CONCLUSION: The perception of humanized childbirth in patients who are in immediate postpartum in our hospital is inappropriate, since they were not provided with the appropriate guidance, information on pain management, choosing a position of labor, and having the possibility that a companion is present during the process.

INTRODUCCIÓN: La percepción de las pacientes sobre la atención del parto humanizado es importante para identificar y evitar datos que sugieran violencia obstétrica, que es toda conducta, acción u omisión realizada por personal de la salud que afecte el cuerpo y los procesos reproductivos de las mujeres, expresada en un trato deshumanizado. OBJETIVO: Conocer el nivel de percepción de parto humanizado en las pacientes en periodo de puerperio en el servicio de ginecoobstetricia del Hospital General de Zona No. 1 del Instituto Mexicano del Seguro Social. MATERIAL Y MÉTODOS: Estudio observacional en 190 pacientes en -puerperio inmediato. Se midieron variables demográficas y se -analizó el nivel de percepción de parto humanizado (inadecuado: 18-32 puntos; regular: 35-53; adecuado: 54-72). Se utilizaron estadística descriptiva y medidas de asociación. Se recabó el consentimiento informado por escrito de las participantes y fue autorizado con el número de registro R-2018-301-020. RESULTADOS: La percepción global de parto humanizado fue inadecuada en el 56.8%, regular en el 34.7% y adecuada en el 8.4%. CONCLUSIÓN: La percepción de parto humanizado en las pacientes que están en puerperio inmediato en nuestro hospital es inadecuada, ya que no se les proporcionaron la orientación adecuada, la información sobre el manejo del dolor, la elección de la posición del trabajo de parto ni la posibilidad de que un acompañante estuviera presente durante el proceso.

Department of Veterans Affairs Consensus: Preradiation dental treatment guidelines for patients with head and neck cancer.

Few protocols have been published for the dental management of patients with head and neck cancer to prevent complications from head and neck radiation therapy. Radiation therapy not only affects the tumor cells targeted, but also the dentition, bone, salivary gland, and oral soft tissue structures. A comprehensive dental evaluation prior to head and neck radiation therapy can help prevent many complications. The following clinical guidelines were established by a workgroup of oral health providers within the Department of Veterans Affairs. This workgroup focused on developing a set of recommendations regarding dental care prior to the initiation of head and neck radiation therapy based on the best clinical evidence and expert consensus. A systematic algorithm was developed for the evaluation including pre-exam data gathering, examination, education, and treatment, followed by maintenance and postradiation dental follow-up. This document is evidence-based, patient-centered, consistent with accepted practices of care and safety, and in accordance with applicable statutes and regulations.

Eficacia de las etiquetas de advertencia en las cajetillas de cigarrillo

[RESUMEN]. Objetivo. Establecer la capacidad que tienen las etiquetas de advertencia con el tamaño mínimo exigido por la Organización Mundial de la Salud para capturar la atención en fumadores y no fumadores. Métodos. En el estudio se incluyeron 30 fumadores y 30 no fumadores, quienes realizaron una prueba de detección del punto (dot-probe) en la cual observaron, de manera simultánea, imágenes de cajetillas de cigarrillo divididas en dos: la parte superior contenía la marca de los cigarrillos y la parte inferior contenía la etiqueta de advertencia. Durante la tarea, se registró la actividad cerebral a través de los potenciales relacionados a eventos del tipo potencial negativo que ocurre aproximadamente a los 200 ms en la zona posterior contralateral al estímulo (N2pc) y negatividad contralateral posterior sostenida (SPCN, por sus siglas en inglés), los cuales son indicadores de atención temprana y sostenida. Resultados. En ambos grupos se encontró mayor amplitud de los potenciales N2pc y SPCN hacia la porción de la cajetilla que contiene la marca de cigarrillos. Sin embargo, el tiempo de reacción fue menor ante la etiqueta de advertencia en la tarea dot-probe. Conclusiones. Los resultados sugieren que, al inicio, la atención se dirige hacia la marca de los cigarrillos y luego hacia la etiqueta de advertencia. La incapacidad de las etiquetas de advertencia para capturar la atención en las primeras fases disminuye su eficacia, sobre todo en fumadores. Se sugiere aumentar el tamaño de las etiquetas de advertencia para favorecer un incremento en la respuesta de atención.

[ABSTRACT]. Objective. To determine the ability of cigarette-pack warning labels, of the minimum size required by the World Health Organization, to capture the attention of smokers and nonsmokers. Methods. In this study, 30 smokers and 30 nonsmokers completed a dot-probe task in which they simultaneously observed images of cigarette packs split in two: the top contained the cigarette brand and the bottom contained the warning label. During the task, brain activity was recorded through two event-related potentials of the negative-polarity type––the potential that occurs in the posterior-contralateral zone approximately 200 ms after a stimulus (N2pc) and the sustained posterior contralateral negativity (SPCN) response––which are indicators of early and sustained attention. Results. In both groups, a greater amplitude of N2pc and SPCN potentials was found for the part of the pack containing the cigarette brand. However, during the dot-probe task, reaction times were shorter for the warning label. Conclusions. These results suggest that, initially, attention is focused on the cigarette brand, and only then on the warning label. The inability of warning labels to capture early-phase attention decreases their effectiveness, especially in smokers. We suggest that warning labels be enlarged to facilitate increased attention response.

[RESUMO]. Objetivo. Determinar a capacidade das tarjas de advertência com o tamanho mínimo exigido pela Organização Mundial da Saúde (OMS) de atrair a atenção de fumantes e não fumantes. Métodos. A amostra do estudo consistiu de 30 fumantes e 30 não fumantes que foram testados com uma tarefa de sondagem (dot-probe task) em que tiveram de observar simultaneamente imagens de um maço de cigarro dividido ao meio: a parte superior continha a marca do cigarro e a parte inferior continha a tarja de advertência. Durante o teste, foi registrada a atividade cerebral com a análise de potenciais evocados relacionados a eventos do tipo potencial negativo que ocorre em cerca de 200 ms na área posterior contralateral ao estímulo (N2pc) e da ocorrência de negatividade contralateral posterior sustentada (SPCN, em inglês), que são indicadores de atenção mais rápida e sustentada. Resultados. Em ambos os grupos de participantes foi observada maior amplitude dos potenciais N2pc e SPCN na parte do maço que continha a marca. Porém, o tempo de reação na tarefa de sondagem foi menor diante da tarja de advertência. Conclusões. Os resultados deste estudo sugerem que, ao início, a atenção é dirigida à marca do cigarro e depois à tarja de advertência. A incapacidade da tarja de advertência de atrair a atenção nas primeiras fases diminui sua eficácia, sobretudo entre os fumantes. Recomenda-se aumentar o tamanho das tarjas de advertência para estimular um incremento na resposta de atenção.

[Effectiveness of cigarette-pack warning labels in capturing the attention of smokers and nonsmokersEficácia das tarjas de advertência em maços de cigarro para atrair a atenção de fumantes e não fumantes]. / Eficacia de las etiquetas de advertencia en las cajetillas de cigarrillo.

OBJECTIVE: To determine the ability of cigarette-pack warning labels, of the minimum size required by the World Health Organization, to capture the attention of smokers and nonsmokers. METHODS: In this study, 30 smokers and 30 nonsmokers completed a dot-probe task in which they simultaneously observed images of cigarette packs split in two: the top contained the cigarette brand and the bottom contained the warning label. During the task, brain activity was recorded through two event-related potentials of the negative-polarity type--the potential that occurs in the posterior-contralateral zone approximately 200 ms after a stimulus (N2pc) and the sustained posterior contralateral negativity (SPCN) response--which are indicators of early and sustained attention. RESULTS: In both groups, a greater amplitude of N2pc and SPCN potentials was found for the part of the pack containing the cigarette brand. However, during the dot-probe task, reaction times were shorter for the warning label. CONCLUSIONS: These results suggest that, initially, attention is focused on the cigarette brand, and only then on the warning label. The inability of warning labels to capture early-phase attention decreases their effectiveness, especially in smokers. We suggest that warning labels be enlarged to facilitate increased attention response.

OBJETIVO: Determinar a capacidade das tarjas de advertência com o tamanho mínimo exigido pela Organização Mundial da Saúde (OMS) de atrair a atenção de fumantes e não fumantes. MÉTODOS: A amostra do estudo consistiu de 30 fumantes e 30 não fumantes que foram testados com uma tarefa de sondagem (dot-probe task) em que tiveram de observar simultaneamente imagens de um maço de cigarro dividido ao meio: a parte superior continha a marca do cigarro e a parte inferior continha a tarja de advertência. Durante o teste, foi registrada a atividade cerebral com a análise de potenciais evocados relacionados a eventos do tipo potencial negativo que ocorre em cerca de 200 ms na área posterior contralateral ao estímulo (N2pc) e da ocorrência de negatividade contralateral posterior sustentada (SPCN, em inglês), que são indicadores de atenção mais rápida e sustentada. RESULTADOS: Em ambos os grupos de participantes foi observada maior amplitude dos potenciais N2pc e SPCN na parte do maço que continha a marca. Porém, o tempo de reação na tarefa de sondagem foi menor diante da tarja de advertência. CONCLUSÕES: Os resultados deste estudo sugerem que, ao início, a atenção é dirigida à marca do cigarro e depois à tarja de advertência. A incapacidade da tarja de advertência de atrair a atenção nas primeiras fases diminui sua eficácia, sobretudo entre os fumantes. Recomenda-se aumentar o tamanho das tarjas de advertência para estimular um incremento na resposta de atenção.

Modeling of a C-end rule peptide adsorbed onto gold nanoparticles.

The RPAR peptide, a prototype C-end Rule (CendR) sequence that binds to neuropilin-1 (NRP-1), has potential therapeutic uses as internalization trigger in anticancer nanodevices. Recently, the functionalization of gold nanoparticles with CendR peptides has been proved to be a successful strategy to target the NRP-1 receptor in prostate cancer cells. In this work, we investigate the influence of two gold surface facets, (100) and (111), on the conformational preferences of RPAR using molecular dynamics simulations. Both clustering and conformational analyses revealed that the peptide backbone becomes very rigid upon adsorption onto gold, which is a very fast and favored process, the only flexibility being attributed to the side chains of the two Arg residues. Thus, the different components of RPAR tend to adopt an elongated shape, which is characterized by the pseudo-extended conformation of both the backbone and the Arg side chains. This conformation is very different from the already known bioactive conformation, indicating that RPAR is drastically affected by the substrate. Interestingly, the preferred conformations of the peptide adsorbed onto gold facets are not stabilized by salt bridges and/or specific intramolecular hydrogen bonds, which represent an important difference with respect to the conformations found in other environments (e.g. the peptide in solution and interacting with NRP-1 receptor). However, the conformational changes induced by the substrate are not detrimental for the use of gold nanoparticles as appropriate vehicles for the transport and targeted delivery of the RPAR. Thus, once their high affinity for the NRP-1 receptor induces the targeted delivery of the elongated peptide molecules from the gold nanoparticles, the lack of intramolecular interactions facilitates their evolution towards the bioactive conformation, increasing the therapeutic efficacy of the peptide.

Eficacia de las etiquetas de advertencia en las cajetillas de cigarrillo / Effectiveness of cigarette-pack warning labels in capturing the attention of smokers and nonsmokers / Eficácia das tarjas de advertência em maços de cigarro para atrair a atenção de fumantes e não fumantes

RESUMEN Objetivo Establecer la capacidad que tienen las etiquetas de advertencia con el tamaño mínimo exigido por la Organización Mundial de la Salud para capturar la atención en fumadores y no fumadores. Métodos En el estudio se incluyeron 30 fumadores y 30 no fumadores, quienes realizaron una prueba de detección del punto (dot-probe) en la cual observaron, de manera simultánea, imágenes de cajetillas de cigarrillo divididas en dos: la parte superior contenía la marca de los cigarrillos y la parte inferior contenía la etiqueta de advertencia. Durante la tarea, se registró la actividad cerebral a través de los potenciales relacionados a eventos del tipo potencial negativo que ocurre aproximadamente a los 200 ms en la zona posterior contralateral al estímulo (N2pc) y negatividad contralateral posterior sostenida (SPCN, por sus siglas en inglés), los cuales son indicadores de atención temprana y sostenida. Resultados En ambos grupos se encontró mayor amplitud de los potenciales N2pc y SPCN hacia la porción de la cajetilla que contiene la marca de cigarrillos. Sin embargo, el tiempo de reacción fue menor ante la etiqueta de advertencia en la tarea dot-probe. Conclusiones Los resultados sugieren que, al inicio, la atención se dirige hacia la marca de los cigarrillos y luego hacia la etiqueta de advertencia. La incapacidad de las etiquetas de advertencia para capturar la atención en las primeras fases disminuye su eficacia, sobre todo en fumadores. Se sugiere aumentar el tamaño de las etiquetas de advertencia para favorecer un incremento en la respuesta de atención.

ABSTRACT Objective To determine the ability of cigarette-pack warning labels, of the minimum size required by the World Health Organization, to capture the attention of smokers and nonsmokers. Methods In this study, 30 smokers and 30 nonsmokers completed a dot-probe task in which they simultaneously observed images of cigarette packs split in two: the top contained the cigarette brand and the bottom contained the warning label. During the task, brain activity was recorded through two event-related potentials of the negative-polarity type--the potential that occurs in the posterior-contralateral zone approximately 200 ms after a stimulus (N2pc) and the sustained posterior contralateral negativity (SPCN) response--which are indicators of early and sustained attention. Results In both groups, a greater amplitude of N2pc and SPCN potentials was found for the part of the pack containing the cigarette brand. However, during the dot-probe task, reaction times were shorter for the warning label. Conclusions These results suggest that, initially, attention is focused on the cigarette brand, and only then on the warning label. The inability of warning labels to capture early-phase attention decreases their effectiveness, especially in smokers. We suggest that warning labels be enlarged to facilitate increased attention response.

RESUMO Objetivo Determinar a capacidade das tarjas de advertência com o tamanho mínimo exigido pela Organização Mundial da Saúde (OMS) de atrair a atenção de fumantes e não fumantes. Métodos A amostra do estudo consistiu de 30 fumantes e 30 não fumantes que foram testados com uma tarefa de sondagem (dot-probe task) em que tiveram de observar simultaneamente imagens de um maço de cigarro dividido ao meio: a parte superior continha a marca do cigarro e a parte inferior continha a tarja de advertência. Durante o teste, foi registrada a atividade cerebral com a análise de potenciais evocados relacionados a eventos do tipo potencial negativo que ocorre em cerca de 200 ms na área posterior contralateral ao estímulo (N2pc) e da ocorrência de negatividade contralateral posterior sustentada (SPCN, em inglês), que são indicadores de atenção mais rápida e sustentada. Resultados Em ambos os grupos de participantes foi observada maior amplitude dos potenciais N2pc e SPCN na parte do maço que continha a marca. Porém, o tempo de reação na tarefa de sondagem foi menor diante da tarja de advertência. Conclusões Os resultados deste estudo sugerem que, ao início, a atenção é dirigida à marca do cigarro e depois à tarja de advertência. A incapacidade da tarja de advertência de atrair a atenção nas primeiras fases diminui sua eficácia, sobretudo entre os fumantes. Recomenda-se aumentar o tamanho das tarjas de advertência para estimular um incremento na resposta de atenção.

Feasibility of Multiplane-Transmit Beamforming for Real-Time Volumetric Cardiac Imaging: A Simulation Study.

Today's 3-D cardiac ultrasound imaging systems suffer from relatively low spatial and temporal resolution, limiting their applicability in daily clinical practice. To address this problem, 3-D diverging wave imaging with spatial coherent compounding (DWC) as well as 3-D multiline-transmit (MLT) imaging have recently been proposed. Currently, the former improves the temporal resolution significantly at the expense of image quality and the risk of introducing motion artifacts, whereas the latter only provides a moderate gain in volume rate but mostly preserves quality. In this paper, a new technique for real-time volumetric cardiac imaging is proposed by combining the strengths of both approaches. Hereto, multiple planar (i.e., 2-D) diverging waves are simultaneously transmitted in order to scan the 3-D volume, i.e., multiplane transmit (MPT) beamforming. The performance of a 3MPT imaging system was contrasted to that of a 3-D DWC system and that of a 3-D MLT system by computer simulations during both static and moving conditions of the target structures while operating at similar volume rate. It was demonstrated that for stationary targets, the 3MPT imaging system was competitive with both the 3-D DWC and 3-D MLT systems in terms of spatial resolution and sidelobe levels (i.e., image quality). However, for moving targets, the image quality quickly deteriorated for the 3-D DWC systems while it remained stable for the 3MPT system while operating at twice the volume rate of the 3-D-MLT system. The proposed MPT beamforming approach was thus demonstrated to be feasible and competitive to state-of-the-art methodologies.

Radiation grafting of N-vinylcaprolactam onto nano and macrogels of chitosan: Synthesis and characterization.

The aim of this study was to synthesize chitosan hydrogels, in macro- and nano-size, grafted with N-vinylcaprolactam (NVCL) using gamma radiation, and evaluate their potential application as a drug delivery system, using 5-fluorouracil (5-FU) as a model drug. The effect of dose and monomer concentration in the grafting process was studied, and the materials were characterized by FTIR, TGA, DLS, SEM and AFM. Higher grafting percentages were observed for the nanogels system. Although both the grafted macro- and nanogels, (net-CS)-g-NVCL, showed a response to pH (4.75) and temperature (31-33°C), the nanogels showed a better swelling response to both stimuli because of their higher surface area. Both systems were able to load 5-FU in small amounts (2-3.5mgg-1) and the release was sustained for more than 12h, showing that the modified macro and nanogels can be a potential alternative for the administration of drugs.

A Comparison of the Performance of Different Multiline Transmit Setups for Fast Volumetric Cardiac Ultrasound.

It was previously demonstrated in 2-D echocardiography that a proper multiline transmit (MLT) implementation can be used to increase frame rate while preserving image quality. Initial findings for extending MLT to 3-D showed that it might address the low spatiotemporal resolution of current volumetric ultrasound systems. However, to date, it remains unclear how much transmit/receive parallelization would be possible using a 3-D MLT system. Therefore, the aim of this paper was to contrast different MLT setups for 3-D imaging by computer simulation in order to determine an optimal tradeoff between the amount of parallelization of an MLT system and the corresponding signal-to-noise ratio of the resulting images. Hereto, the image quality of several MLT setups was estimated by quantifying their crosstalk energy level. The results showed that for the tested setups, 4MLT broad beams and 9MLT narrow beams with Tukey ( α = 0.5 ) apodization in transmit and receive give the highest frame rate gain while maintaining an acceptable interbeam interference level. Moreover, although 16MLT narrow beams with Tukey/Tukey ( α = 0.5 ) apodization did show more pronounced interbeam interference, its gain in frame rate might outweigh its predicted loss in image quality. As such both 9MLT and 16MLT narrow beams were tested experimentally. For both systems, four receive lines were reconstructed from each transmit beam. The contrast-to-noise ratio of these imaging strategies was quantified and compared with the image quality obtained with line-by-line scanning. Despite some expected loss in image quality, the resulting images of the parallelized systems were very competitive to the benchmark, while speeding up the acquisition process by a factor of 36 and 64, respectively.

Acoustic output of multi-line transmit beamforming for fast cardiac imaging: a simulation study.

Achieving higher frame rates in cardiac ultrasound could unveil short-lived myocardial events and lead to new insights on cardiac function. Multi-line transmit (MLT) beamforming (i.e., simultaneously transmitting multiple focused beams) is a potential approach to achieve this. However, two challenges come with it: first, it leads to cross-talk between the MLT beams, appearing as imaging artifacts, and second, it presents acoustic summation in the near field, where multiple MLT beams overlap. Although several studies have focused on the former, no studies have looked into the implications of the latter on acoustic safety. In this paper, the acoustic field of 4-MLT was simulated and compared with single-line transmit (SLT). The findings suggest that standard MLT does present potential concerns. Compared with SLT, it shows a 2-fold increase in mechanical index (MI) (from 1.0 to 2.3), a 6-fold increase in spatial-peak pulse-average intensity (I(sppa)) (from 99 to 576 W∙cm(-2)) and a 12-fold increase in spatial-peak temporalaverage intensity (I(spta)) (from 119 to 1407 mW∙cm(-2)). Subsequently, modifications of the transmit pulse and delay line of MLT were studied. These modifications allowed for a change in the spatio-temporal distribution of the acoustic output, thereby significantly decreasing the safety indices (MI = 1.2, I(sppa) = 92 W∙cm(-2) and I(spta) = 366 mW∙cm(-2)). Accordingly, they help mitigate the concerns around MLT, reducing potential tradeoffs between acoustic safety and image quality.