Morphological and Molecular Identification of Ulva spp. (Ulvophyceae; Chlorophyta) from Algarrobo Bay, Chile: Understanding the Composition of Green Tides.

Green algae blooms of the genus Ulva are occurring globally and are primarily attributed to anthropogenic factors. At Los Tubos beach in Algarrobo Bay along the central Chilean coast, there have been blooms of these algae that persist almost year-round over the past 20 years, leading to environmental, economic, and social issues that affect the local government and communities. The objective of this study was to characterize the species that form these green tides based on a combination of ecological, morpho-anatomical, and molecular information. For this purpose, seasonal surveys of beached algal fronds were conducted between 2021 and 2022. Subsequently, the sampled algae were analyzed morphologically and phylogenetically using the molecular markers ITS1 and tufA, allowing for the identification of at least five taxa. Of these five taxa, three (U. stenophylloides, U. uncialis, U. australis) have laminar, foliose, and distromatic morphology, while the other two (U. compressa, U. aragoensis) have tubular, filamentous, and monostromatic fronds. Intertidal surveys showed that U. stenophylloides showed the highest relative coverage throughout the seasons and all intertidal levels, followed by U. uncialis. Therefore, we can establish that the green tides on the coast of Algarrobo in Chile are multispecific, with differences in relative abundance during different seasons and across the intertidal zone, opening opportunities for diverse future studies, ranging from ecology to algal biotechnology.

Expansion of marine pollution along the coast: Negative effects on kelps and contamination transference to benthic herbivores?

Heavy metals and polycyclic aromatic hydrocarbons (PAHs) are ubiquitous contaminants that frequently co-occur in coastal environments. These contaminants can have negative impacts on the health and stability of marine and coastal ecosystems, affecting both the organisms themselves and the humans who consume them. A coastal industrial park in central Chile, housing a coal thermal power plant and other industrial activities, contributes to such pollution of coastal waters; however, neither the spatial alongshore distribution of heavy metals and PAHs, nor an assessment of their ecological effects on the biota have been systematically documented to date. In this paper, we present evidence regarding the direct negative effect of contamination by heavy metals and PAHs on the early life stages of kelps-being extremely harmful to their population persistence near highly polluted sites-as well as the indirect effects of their transference through the food web to higher trophic levels, leading to negative consequences for the feeding intake, growth, fertility, and larval development of marine herbivores that consume the contaminated seaweed. Likewise, the dispersion of contaminants by ocean currents can exacerbate the effects of pollution, having an adverse influence on marine ecosystem health even at sites far from the pollution source. Therefore, it is necessary to investigate the distribution patterns and extent of pollution along the coast to understand the impact of heavy metals and PAHs pollution on seaweed populations and the food web. It is considered critical for the development of effective environmental policies and regulations to protect these ecosystems and the people who depend on them.

Heavy Metal Depuration Steps for Gracilaria chilensis in Outdoor Culture Systems.

Seaweed aquaculture is affected by natural and anthropogenic stressors, which put the biomass productivity of the cultures at risk. Seaweed biomass for commercial purposes, principally in pharmaceutical and/or nutraceutical applications, needs to be free of pollutants; therefore, controlled cultures have relevance in regulating the quality of biomass. The aim of this work was to demonstrate the successful utilization of controlled outdoor cultures to remove excess heavy metal accumulation in Gracilaria chilensis, an important commercial seaweed farming model. Specifically, we designed a simple and operational heavy metal depuration protocol, utilizing seawater and tap water removal, which permitted the concentration reduction of 10 heavy metals, including As, Cu, and Cd but not Zn, from the biomass at 7 days of culture. The percentage of depuration of the heavy metals ranged from 32 to 92% at 7 days, which was maintained throughout 21 days of culture. During the culture period, the monitored physicochemical parameters (temperature, salinity, and dissolved oxygen, among others) remained stable, with an increase in the daily growth rate (DGR% d-1) of the biomass recorded after 14 days of culture. Consequently, the experimental setup was successful for heavy metal depuration, which highlights the importance of controlled outdoor cultures as important tools of sustainability.

Transfer of Pollutants from Macrocystis pyrifera to Tetrapygus niger in a Highly Impacted Coastal Zone of Chile.

PAHs and heavy metals are characteristic pollutants in urbanized coastal areas, especially those with industrial activity. Given this context and the ability of Macrocystis pyrifera to drift when detached and provide trophic subsidy in coastal systems, we analyzed the potential transfer of pollutants to the herbivore Tetrapygus niger, through diet, in an industrialized coastal zone in Central Chile (Caleta Horcón) and characterized the impacted zone using diverse polluted ecotoxicological indices. For this purpose, a culture experiment was conducted where M. pyrifera individuals from Algarrobo (control site) were cultivated in Caleta Horcón and then used as food for T. niger. The contents of both PAHs and heavy metal contents were subsequently determined in algal tissue and sea urchin gonads as well as in the seawater. The results show that algae cultivated in Caleta Horcón had higher concentrations of naphthalene (NAF) compared to those from a low industrial impact zone (Algarrobo) (2.5 and 1.8 mg kg-1, respectively). The concentrations of Cu, As, and Cd were higher in Caleta Horcón than in Algarrobo in both M. pyrifera and T. niger. For all metals, including Pb, higher concentrations were present in T. niger than in M. pyrifera (between 5 and 798 times higher). Additionally, as indicated by the toxicological indices MPI (0.00804) and PLI (10.89), Caleta Horcón is highly contaminated with metals compared to Algarrobo (0.0006 and 0.015, respectively). Finally, the bioconcentration factor (BCF) and trophic transfer factor (TTF) values were greater than one in most cases, with values in Caleta Horcón exceeding those in Algarrobo by one or two orders of magnitude. This study provides evidence that Caleta Horcón is a highly impacted zone (HIZ) compared to Algarrobo, in addition to evidence that the biomagnification of certain pollutants, including the possible responses to contaminants, are apparently not exclusively transferred to T. niger through diet.

Negative Consequences on the Growth, Morphometry, and Community Structure of the Kelp Macrocystis pyrifera (Phaeophyceae, Ochrophyta) by a Short Pollution Pulse of Heavy Metals and PAHs.

The study of pollution effects in the marine environment has become important in recent decades, and the exposure to simultaneous pollutants has become especially relevant. Indeed, the study of key organisms, such as ecosystem engineers, can show a broader view of the effects of pollutants. In this context, we evaluate in situ the effects of a short (7-day) pollution pulse of combined solutions of heavy metals and polycyclic aromatic hydrocarbons (PAHs) (Cu + PAHs, Cd + PAHs, Cu + Cd, and Cu + Cd + PAHs) on the development and morphological features of Macrocystis pyrifera sporophytes over a period of 90 days. Additionally, we determined the effects on the community structure associated with this kelp. This study evidenced a smaller number of blades and a decreased size of blades and holdfasts, as well as the death of individuals exposed to a secondary mix of metals (Cu + Cd) and a tertiary mix of pollutants (Cu + Cd + PAHs). Regarding the effects on the accompanying fauna, low richness and diversity were registered. M. pyrifera grazers, according to the mixture of pollutants, were either absent or diminished. These results show that the pulse of contamination in the early stages of M. pyrifera negatively affects its development and morphometry, as well as its role as an ecosystem engineer, due to a negative alteration in the species composition.

Ingestion of contaminated kelps by the herbivore Tetrapygus niger: Negative effects on food intake, growth, fertility, and early development.

Macrocystis pyrifera reaches distant areas after detachment, accumulate heavy metals, and serve as trophic subsidy. In this context, effects on both adults and larvae of Tetrapygus niger fed with polluted kelps were determined by assessing growth, fertility, and early larval development. Results revealed that sea urchins fed with polluted kelps from highly impacted zone (HIZ) showed a lower growth (3.6% gained weight) and gamete release (358 cells mL-1) than those fed with non-impacted kelps (NIZ) (19.3% and 945 cells mL-1). The HIZ treatment showed a developmental delay in comparison to NIZ, accounted mainly by the abundance of malformed 2-arm pluteus larvae (10-15%) during most of the culture. Malformed 4-arm pluteus larvae showed a constant increase, reaching 37% at the end of the culture. Thus, the pollutants ingested by sea urchins can be transferred to their offspring and cause negative effects in their early development, categorizing M. pyrifera as a pollutant carrier.

Integrating Cyber-Physical Systems in a Component-Based Approach for Smart Homes.

Integration of different cyber-physical systems involves a development process that takes into account some solutions for intercommunicating and interoperating heterogeneous devices. Each device can be managed as a thing within the Internet-of-Things concept by using web technologies. In addition, a “thing” can be managed as an encapsulated component by applying component-based software engineering principles. Based on this context, we propose a solution for integrating heterogeneous systems using a specific component-based technology. Specifically, we focus on enabling the connection of different types of subsystems present in smart home solutions. This technology enables interoperability by applying a homogeneous component representation that provides communication features through web sockets, and by implementing gateways in proprietary network connections. Furthermore, our solution eases the extension of these systems by means of abstract representations of the architectures and devices that form part of them. The approach is validated through an example scenario with different subsystems of a smart home solution.

Tracking Lithium Ions via Widefield Fluorescence Microscopy for Battery Diagnostics.

Direct tracking of lithium ions with time and spatial resolution can provide an important diagnostic tool for understanding mechanisms in lithium ion batteries. A fluorescent indicator of lithium ions, 2-(2-hydroxyphenyl)naphthoxazole, was synthesized and used for real-time tracking of lithium ions via widefield fluorescence microscopy. The fluorophore can be excited with visible light and was shown to enable quantitative determination of the lithium ion diffusion constant in a microfluidic model system for a plasticized polymer electrolyte lithium battery. The use of widefield fluorescence microscopy for in situ tracking of lithium ions in batteries is discussed.

Probing Heterogeneity and Bonding at Silica Surfaces through Single-Molecule Investigation of Base-Mediated Linkage Failure.

The nature of silica surfaces is relevant to many chemical systems, including heterogeneous catalysis and chromatographies utilizing functionalized-silica stationary phases. Surface linkages must be robust to achieve wide and reliable applicability. However, silyl ether-silica support linkages are known to be susceptible to detachment when exposed to basic conditions. We use single-molecule spectroscopy to examine the rate of surface linkage failure upon exposure to base at a variety of deposition conditions. Kinetic analysis elucidates the role of thermal annealing and addition of blocking layers in increasing stability. Critically, it was found that successful surface modification strategies alter the rate at which base molecules approach the silica surface as opposed to reducing surface linkage reactivity. Our results also demonstrate that the innate structural diversity of the silica surface is likely the cause of observed heterogeneity in surface-linkage disruption kinetics.

Single-Molecule Investigation of Initiation Dynamics of an Organometallic Catalyst.

The action of molecular catalysts comprises multiple microscopic kinetic steps whose nature is of central importance in determining catalyst activity and selectivity. Single-molecule microscopy enables the direct examination of these steps, including elucidation of molecule-to-molecule variability. Such molecular diversity is particularly important for the behavior of molecular catalysts supported at surfaces. We present the first combined investigation of the initiation dynamics of an operational palladium cross-coupling catalyst at the bulk and single-molecule levels, including under turnover conditions. Base-initiated kinetics reveal highly heterogeneous behavior indicative of diverse catalyst population. Unexpectedly, this distribution becomes more heterogeneous at increasing base concentration. We model this behavior with a two-step saturation mechanism and identify specific microscopic steps where chemical variability must exist in order to yield observed behavior. Critically, we reveal how structural diversity at a surface translates into heterogeneity in catalyst behavior, while demonstrating how single-molecule experiments can contribute to understanding of molecular catalysts.

OntoTrader: an ontological Web trading agent approach for environmental information retrieval.

Modern Web-based Information Systems (WIS) are becoming increasingly necessary to provide support for users who are in different places with different types of information, by facilitating their access to the information, decision making, workgroups, and so forth. Design of these systems requires the use of standardized methods and techniques that enable a common vocabulary to be defined to represent the underlying knowledge. Thus, mediation elements such as traders enrich the interoperability of web components in open distributed systems. These traders must operate with other third-party traders and/or agents in the system, which must also use a common vocabulary for communication between them. This paper presents the OntoTrader architecture, an Ontological Web Trading agent based on the OMG ODP trading standard. It also presents the ontology needed by some system agents to communicate with the trading agent and the behavioral framework for the SOLERES OntoTrader agent, an Environmental Management Information System (EMIS). This framework implements a "Query-Searching/Recovering-Response" information retrieval model using a trading service, SPARQL notation, and the JADE platform. The paper also presents reflection, delegation and, federation mediation models and describes formalization, an experimental testing environment in three scenarios, and a tool which allows our proposal to be evaluated and validated.

Low birthweight in Mexico: a systematic review.

There is abundant literature on the birth outcomes of women of Mexican origin living in the United States, but in most cases it does not refer to data available in Mexico. We conducted a systematic review of available data regarding low birthweight (LBW) rates in Mexico. We searched official online Mexican administrative data bases and four literature databases: OVID (Global Health), EMBASE, PubMed, and Bireme. The following inclusion criteria were used: (1) study is in English, Spanish, or Portuguese; (2) study presents data regarding LBW or birthweight distribution in Mexico; (3) study defines LBW as either < or ≤2,500 g; (4) study population includes newborn children; and, (5) LBW was a primary interest of the study. Because altitude influences birthweight, it was taken into account when comparing regions. Birth certificate data showed LBW rates of 8.2% in 2008 and 8.5% in 2009 among live births with known birthweights. In 2009, high altitude (≥2,000 m) federal entities (states and Mexico City) had LBW rates higher than the median (>7.9%). States at low altitudes (<50 m) had LBW rates lower than the median, with the exception of Yucatán state. The systematic literature review identified 22 hospital-based studies and three household interview surveys that met our inclusion criteria. The hospital-based LBW rates were relatively similar to the birth certificate data and slightly lower than survey data. Data on LBW rates are available in Mexico. They should be analyzed further and used for comparative studies.

Global Networking of Cancer and NCD professionals using internet technologies: the Supercourse and mHealth applications.

Cancer is a leading cause of death around the world. Education is at the core of cancer prevention activities, especially programs targeting empowering existing public health workforce. In the past 10 years, researchers at the University of Pittsburgh have been building the Global Health Network Supercourse project, a library of over 4500 online lectures and a network of nearly 50000 public health professionals in 174 countries. As of November, 2010, the overall number of Supercourse participants from Asia exceeds 7000 participants. The Supercourse network has been investigating methods for Internet based recruitment of cancer prevention professionals in order to network cancer experts locally and globally, including the use of mHealth technologies for cancer research education and for NCD registries. Supercourse is a tool that can offer a solution to the challenges of information sharing, especially in the field of NCDs and cancer. In this paper, we highlight the need for the development of Cancer Supercourse with Satellite in Asia and encourage faculty members from Asia to join the network.

Mother-to-child transmission of Chagas' disease in North America: why don't we do more?

OBJECTIVES: Mothers with Chagas' disease can transmit Trypanosoma cruzi to their fetuses, who often become carriers of the infection and are then at risk of developing severe cardiac disease later in the course of their lives. If identified early enough after birth, the infected newborns can be treated and cured. Our objective was to review the data available in Canada, Mexico, and the United States and to discuss the need for prevention programs. METHODS: We reviewed the literature and estimated the number of seropositive mothers and newborns infected by T. cruzi. RESULTS: We estimate that about 40,000 pregnant women and 2,000 newborns are likely to be infected by T. cruzi in North America. We have not identified any ongoing prevention programs. CONCLUSIONS: Mother-to-child transmission of T. cruzi has all the characteristics required to be a public health priority, as it is relatively frequent, severe, identifiable, and treatable. In reality, it is a neglected disease and a missed opportunity. It is urgent to better understand the epidemiology of mother-to-child transmission of T. cruzi in North America and to develop effective prevention programs.

Antiamoebic chemoprophylaxis using quinfamide in children: a comparative study.

This study sought to examine whether the administration of quinfamide at 3- or 6-month intervals diminished the frequency of Entamoeba histolytica cysts in stool samples compared to controls. The prospective, longitudinal, randomized, single-blind study examined children from six primary schools in Celaya and Neutla, Guanajuato. Of the 1,524 students in these schools, we selected participants for the study as follows: Children were included in the study if their parents agreed in writing to the study and if the children demonstrated evidence of E. histolytica cysts after a parasitoscopic analysis by concentration (PSC) in three samples over consecutive days using Faust"s method. Those included in the study received a single 4.3-g/kg dose of quinfamide, and we performed PSC on days 5, 6, and 7 following dose administration to examine whether quinfamide had affected the presence of the cysts. The study participants who tested negative for cysts were divided into three groups: Group 1 had 102 patients who underwent quinfamide treatment and three CPS analyses after the 12 months of the study; Group 2 had 98 subjects who underwent the quinfamide treatment and three CPS analyses at months 3, 6, 9, and 12 after their entrance into the study; and Group 3 had 102 patients, who underwent the quinfamide treatment and series of three CPS analyses at months 6 and 12 of the study. All participants received the dose of quinfamide after providing stool samples and after a clinical gastrointestinal history was obtained. Further clinical gastrointestinal data were collected 5 days after the quintamide dose was administered. We used EpiInfo 6.0 for statistical analysis, calculating c2 and p values for the clinical data and the CPS data after the 12 months concluded. Of the initial samples of 1,524 subjects, 308 (20.2%) had Entamoebic cysts. Of these, six were further eliminated because they did not meet the inclusion requirements. At the conclusion of the study, Group 1 presented with 37.6% of subjects still testing positive for cysts; of Group 2, 12.5% tested positive; and in Group 3, 23.5% of participants tested positive for cysts (chi2 = 16.8; df = 2; p = 0.0002). For comparisons of groups 1 and 2 and 1 and 3, p < 0.05; for the comparison of groups 2 and 3, p > 0.05. We conclude that antiamoebic chemoprophylaxis can be a choice for control of amoebic infection where personal hygiene and food consumption habits are not improving.