Morphological Differentiation, Yield, and Cutting Time of Lolium multiflorum L. under Acid Soil Conditions in Highlands.

Livestock production in the basins of the northern macro-region of Peru has as its primary source pastures of Lolium multiflorum L. 'Cajamarquino ecotype' (ryegrass CE) in monoculture, or in association with white clover Ladino variety, for feeding. The objective of this research work was the morphological characterisation, yield evaluation, and cutting time evaluation of two local genotypes (LM-58 and LM-43) of Lolium multiflorum L. in six locations. An ANOVA was performed to compare fixed effects and interaction. It was determined that the LM-58 genotype is intermediate, growing semi-erect, with a dark green colouring and 0.8 cm broadleaf, and can reach an average stem length of 46 cm, up to 1.6 cm. day-1, achieving fourth-leaf growth at 28 days under appropriate management conditions. Despite the differentiated characteristics, according to BLASTn evaluation, the ITS1 sequences showed a greater than 99.9% similar identification to Lolium multiflorum L., characterising it as such. It was determined that the LM-58 genotype outperforms LM-43, achieving a forage yield of 4.49 Mg. ha-1, a seed production of 259.23 kg. ha-1, and an average of 13.48% crude protein (CP). The best biomass yield (49.10 Mg. ha-1.yr-1) is reached at 60 days; however, at 30 days, there is a high level of CP (14.84%) and there are no differences in the annual protein production at the cutting age of 60 and 45 days. With the results of the present study, LM-58 from a selection and crossbreeding of 680 ryegrass EC accessions emerges as an elite genotype adapted to the conditions of the northern high Andean zone of Peru.

Bacteriemia asociada a catéteres venosos centrales no tunelizados en niños en hemodiálisis crónica / Bacteremia associated with non-tunneled central venous catheters in children undergoing chronic hemodialysis

Introducción. La infección asociada a catéter venoso central (CVC) es la principal complicación que presentan los pacientes en hemodiálisis en los que se usa este tipo de acceso. Objetivo. Estimar la incidencia de bacteriemia asociada a CVC no tunelizado, analizar la frecuencia de agentes causales y explorar factores de riesgo asociados en niños en hemodiálisis. Población y métodos. Estudio retrospectivo realizado en niños en hemodiálisis por CVC no tunelizado entre el 1 junio de 2015 y el 30 de junio de 2019. Para evaluar factores de riesgo predictores de bacteriemia asociada a CVC, se realizó regresión logística. Los factores de riesgo independiente se expresaron con odds ratio con sus respectivos intervalos de confianza del 95 %. Se consideró estadísticamente significativo un valor de p <0,05. Resultados. En este estudio se incluyeron 121 CVC no tunelizados. La incidencia de bacteriemia fue de 3,15 por 1000 días de catéter. El microorganismo aislado con mayor frecuencia fue Staphylococcus epidermidis (16 casos, 51,5 %). La infección previa del catéter fue el único factor de riesgo independiente encontrado para el desarrollo de bacteriemia asociada a CVC no tunelizado (OR: 2,84; IC95%: 1,017,96; p = 0,04). Conclusiones. El uso prolongado de los CVC no tunelizados para hemodiálisis crónica se asoció con una incidencia baja de bacteriemia. Los gérmenes grampositivos predominaron como agentes causales. La presencia de infección previa del CVC aumentó en casi 3 veces el riesgo de bacteriemia asociada a CVC en nuestra población pediátrica en hemodiálisis.

Introduction. Central venous catheter (CVC)-related infection is the main complication observed in patients undergoing hemodialysis with this type of venous access. Objective. To estimate the incidence of non-tunneled CVC-related bacteremia, analyze the frequency ofcausative agents, and explore associated risk factors in children undergoing hemodialysis. Population and methods. Retrospective study in children receiving hemodialysis via a non-tunneled CVC between June 1 st, 2015 and June 30 th, 2019. A logistic regression was carried out to assess risk factors that were predictors of CVC-related bacteremia. Independent risk factors were described as odds ratios with their corresponding 95% confidence interval (CI). A value of p < 0.05 was considered statistically significant. Results. A total of 121 non-tunneled CVCs were included in this study. The incidence of bacteremia was 3.15 per 1000 catheter-days. The most commonly isolated microorganism was Staphylococcus epidermidis(16 cases, 51.5%). Prior catheter infection was the only independent risk factor for the development of bacteremia associated with non-tunneled CVC (OR: 2.84, 95% CI: 1.01­7.96, p = 0.04). Conclusions. Prolonged use of non-tunneled CVCs for chronic hemodialysis was associated with a low incidence of bacteremia. Gram-positive microorganisms prevailed among causative agents. A prior CVC infection almost trebled the risk for CVC-related bacteremia in our pediatric population receiving hemodialysis.

Bacteremia associated with non-tunneled central venous catheters in children undergoing chronic hemodialysis. / Bacteriemia asociada a catéteres venosos centrales no tunelizados en niños en hemodiálisis crónica.

Introduction. Central venous catheter (CVC)-related infection is the main complication observed in patients undergoing hemodialysis with this type of venous access. Objective. To estimate the incidence of non-tunneled CVC-related bacteremia, analyze the frequency of causative agents, and explore associated risk factors in children undergoing hemodialysis. Population and methods. Retrospective study in children receiving hemodialysis via a non-tunneled CVC between June 1st, 2015 and June 30th, 2019. A logistic regression was carried out to assess risk factors that were predictors of CVC-related bacteremia. Independent risk factors were described as odds ratios with their corresponding 95% confidence interval (CI). A value of p < 0.05 was considered statistically significant. Results. A total of 121 non-tunneled CVCs were included in this study. The incidence of bacteremia was 3.15 per 1000 catheter-days. The most commonly isolated microorganism was Staphylococcus epidermidis (16 cases, 51.5%). Prior catheter infection was the only independent risk factor for the development of bacteremia associated with non-tunneled CVC (OR: 2.84, 95% CI: 1.01-7.96, p = 0.04). Conclusions. Prolonged use of non-tunneled CVCs for chronic hemodialysis was associated with a low incidence of bacteremia. Gram-positive microorganisms prevailed among causative agents. A prior CVC infection almost trebled the risk for CVC-related bacteremia in our pediatric population receiving hemodialysis.

Introducción. La infección asociada a catéter venoso central (CVC) es la principal complicación que presentan los pacientes en hemodiálisis en los que se usa este tipo de acceso. Objetivo. Estimar la incidencia de bacteriemia asociada a CVC no tunelizado, analizar la frecuencia de agentes causales y explorar factores de riesgo asociados en niños en hemodiálisis. Población y métodos. Estudio retrospectivo realizado en niños en hemodiálisis por CVC no tunelizado entre el 1 junio de 2015 y el 30 de junio de 2019. Para evaluar factores de riesgo predictores de bacteriemia asociada a CVC, se realizó regresión logística. Los factores de riesgo independiente se expresaron con odds ratio con sus respectivos intervalos de confianza del 95 %. Se consideró estadísticamente significativo un valor de p <0,05. Resultados. En este estudio se incluyeron 121 CVC no tunelizados. La incidencia de bacteriemia fue de 3,15 por 1000 días de catéter. El microorganismo aislado con mayor frecuencia fue Staphylococcus epidermidis (16 casos, 51,5 %). La infección previa del catéter fue el único factor de riesgo independiente encontrado para el desarrollo de bacteriemia asociada a CVC no tunelizado (OR: 2,84; IC95%: 1,017,96; p =0,04). Conclusiones. El uso prolongado de los CVC no tunelizados para hemodiálisis crónica se asoció con una incidencia baja de bacteriemia. Los gérmenes grampositivos predominaron como agentes causales. La presencia de infección previa del CVC aumentó en casi 3 veces el riesgo de bacteriemia asociada a CVC en nuestra población pediátrica en hemodiálisis.

Characterization of Dengue Virus 4 Cases in Paraguay, 2019-2020.

In 2019-2020, dengue virus (DENV) type 4 emerged to cause the largest DENV outbreak in Paraguay's history. This study sought to characterize dengue relative to other acute illness cases and use phylogenetic analysis to understand the outbreak's origin. Individuals with an acute illness (≤7 days) were enrolled and tested for DENV nonstructural protein 1 (NS1) and viral RNA by real-time RT-PCR. Near-complete genome sequences were obtained from 62 DENV-4 positive samples. From January 2019 to March 2020, 799 participants were enrolled: 253 dengue (14 severe dengue, 5.5%) and 546 other acute illness cases. DENV-4 was detected in 238 dengue cases (94.1%). NS1 detection by rapid test was 52.5% sensitive (53/101) and 96.5% specific (387/401) for dengue compared to rRT-PCR. DENV-4 sequences were grouped into two clades within genotype II. No clustering was observed based on dengue severity, location, or date. Sequences obtained here were most closely related to 2018 DENV-4 sequences from Paraguay, followed by a 2013 sequence from southern Brazil. DENV-4 can result in large outbreaks, including severe cases, and is poorly detected with available rapid diagnostics. Outbreak strains seem to have been circulating in Paraguay and Brazil prior to 2018, highlighting the importance of sustained DENV genomic surveillance.

Bathymetric origin shapes the physiological responses of Pterygophora californica (Laminariales, Phaeophyceae) to deep marine heatwaves.

Kelp communities are experiencing exacerbated heat-related impacts from more intense, frequent, and deeper marine heatwaves (MHWs), imperiling the long-term survival of kelp forests in the climate change scenario. The occurrence of deep thermal anomalies is of critical importance, as elevated temperatures can impact kelp populations across their entire bathymetric range. This study evaluates the impact of MHWs on mature sporophytes of Pterygophora californica (walking kelp) from the bathymetric extremes (8-10 vs. 25-27 m) of a population situated in Baja California (Mexico). The location is near the southernmost point of the species's broad distribution (from Alaska to Mexico). The study investigated the ecophysiological responses (e.g., photobiology, nitrate uptake, oxidative stress) and growth of adult sporophytes through a two-phase experiment: warming simulating a MHW and a post-MHW phase without warming. Generally, the effects of warming differed depending on the bathymetric origin of the sporophytes. The MHW facilitated essential metabolic functions of deep-water sporophytes, including photosynthesis, and promoted their growth. In contrast, shallow-water sporophytes displayed metabolic stress, reduced growth, and oxidative damage. Upon the cessation of warming, certain responses, such as a decline in nitrate uptake and net productivity, became evident in shallow-water sporophytes, implying a delay in heat-stress response. This indicates that variation in temperatures can result in more prominent effects than warming alone. The greater heat tolerance of sporophytes in deeper waters shows convincing evidence that deep portions of P. californica populations have the potential to serve as refuges from the harmful impacts of MHWs on shallow reefs.

Automatic Detection of Dyspnea in Real Human-Robot Interaction Scenarios.

A respiratory distress estimation technique for telephony previously proposed by the authors is adapted and evaluated in real static and dynamic HRI scenarios. The system is evaluated with a telephone dataset re-recorded using the robotic platform designed and implemented for this study. In addition, the original telephone training data are modified using an environmental model that incorporates natural robot-generated and external noise sources and reverberant effects using room impulse responses (RIRs). The results indicate that the average accuracy and AUC are just 0.4% less than those obtained with matched training/testing conditions with simulated data. Quite surprisingly, there is not much difference in accuracy and AUC between static and dynamic HRI conditions. Moreover, the beamforming methods delay-and-sum and MVDR lead to average improvement in accuracy and AUC equal to 8% and 2%, respectively, when applied to training and testing data. Regarding the complementarity of time-dependent and time-independent features, the combination of both types of classifiers provides the best joint accuracy and AUC score.

Increased suicide rates in Mexico City during the COVID-19 pandemic outbreak: An analysis spanning from 2016 to 2021.

Objective: Coronavirus disease 2019 (COVID-19) has impacted mental health worldwide, and suicide can be a serious outcome of this. Thus, suicide characteristics were examined before and during the COVID-19 pandemic in Mexico City. Methods: This is a retrospective study including all Mexico City residents who had a coroner's record with a cause of death of intentional self-harm (ICD-10) from January 2016 to December 2021. Results: From 2016 to 2021, 3636 people committed suicide, of which 2869 were males (78.9%) and 767 females (21.1%). From 2016 to 2019 the suicide rate remained constant (∼6 per 100000) and dramatically increased in 2020 (10.45 per 100,000), to return to the levels of the previous year in 2021 (6.95 per 100000). The suicide rate in 2020 specifically increased from January to June (COVID-19 outbreak) in all age groups. Moreover, every year young people (15-24 years) have the maximum suicide rate and depression was the main suicide etiology. Conclusion: The COVID-19 pandemic outbreak increased the suicide rate, regardless of age, but suicide prevalence was higher in males and young people, regardless of the COVID-19 pandemic. These findings confirm that suicide is a complex and multifactorial problem and will allow the establishment of new guidelines for prevention and care strategies.

The Experience of Testing for Coronavirus Disease (COVID-19) at a Single Diagnostic Center in Paraguay before the Introduction of Vaccination.

Soon after the declaration of the COVID-19 pandemic, the Institute for Health Sciences Research (IICS) of the National University of Asunción, Paraguay became a testing laboratory (COVID-Lab) for SARS-CoV-2. The COVID-Lab testing performance was assessed from 1 April 2020 to 12 May 2021. The effect of the pandemic on the IICS and how the COVID-Lab contributed to the academic and research activities of the institute were also assessed. IICS researchers and staff adjusted their work schedules to support the COVID-Lab. Of the 13,082 nasopharyngeal/oropharyngeal swabs processed, 2704 (20.7%) tested positive for SARS-CoV-2 by RT-PCR. Of the individuals testing positive, 55.4% were female and 48.3% were aged 21-40 years. Challenges faced by the COVID-Lab were unstable reagent access and insufficient staff; shifting obligations regarding research, academic instruction, and grantsmanship; and the continuous demands from the public for information on COVID-19. The IICS provided essential testing and reported on the progress of the pandemic. IICS researchers gained better laboratory equipment and expertise in molecular SARS-CoV-2 testing but struggled to manage their conflicting educational and additional research obligations during the pandemic, which affected their productivity. Therefore, policies protecting the time and resources of the faculty and staff engaged in pandemic-related work or research are necessary components of healthcare emergency preparedness.

Dyspnea Severity Assessment Based on Vocalization Behavior with Deep Learning on the Telephone.

In this paper, a system to assess dyspnea with the mMRC scale, on the phone, via deep learning, is proposed. The method is based on modeling the spontaneous behavior of subjects while pronouncing controlled phonetization. These vocalizations were designed, or chosen, to deal with the stationary noise suppression of cellular handsets, to provoke different rates of exhaled air, and to stimulate different levels of fluency. Time-independent and time-dependent engineered features were proposed and selected, and a k-fold scheme with double validation was adopted to select the models with the greatest potential for generalization. Moreover, score fusion methods were also investigated to optimize the complementarity of the controlled phonetizations and features that were engineered and selected. The results reported here were obtained from 104 participants, where 34 corresponded to healthy individuals and 70 were patients with respiratory conditions. The subjects' vocalizations were recorded with a telephone call (i.e., with an IVR server). The system provided an accuracy of 59% (i.e., estimating the correct mMRC), a root mean square error equal to 0.98, false positive rate of 6%, false negative rate of 11%, and an area under the ROC curve equal to 0.97. Finally, a prototype was developed and implemented, with an ASR-based automatic segmentation scheme, to estimate dyspnea on line.

Detection of neutralizing antibodies against flaviviruses in free-ranging birds, Paraguay (2016-2018).

Saint Louis encephalitis virus (SLEV), West Nile virus (WNV) and Ilheus virus (ILHV) are flaviviruses maintained by enzootic transmission networks between mosquitoes and birds. They have been detected in South America, with no records for Paraguay. We detected the presence of neutralizing antibodies for SLEV, WNV and ILHV in free-ranging birds collected in Paraguay (2016-2018). Four positive samples were detected in resident birds: one SLEV (rufous-bellied thrush), one WNV (barred antshrike) and two ILHV (white-tipped dove and shiny cowbird). These results bring new information about enzootic activity of flaviviruses in Paraguay.

Distribution of human papillomavirus genotypes by severity of cervical lesions in HPV screened positive women from the ESTAMPA study in Latin America.

The proportion of HPV16 and 18-associated cervical cancer (CC) appears rather constant worldwide (≥70%), but the relative importance of the other HR-HPV differs slightly by geographical region. Here, we studied the HPV genotype distribution of HPV positive Latin American (LA) women by histological grade, in a sub-cohort from the ESTAMPA study; we also explored the association of age-specific HPV genotypes in severe lesions. Cervical samples from 1,252 participants (854 ≤CIN1, 121 CIN2, 194 CIN3 and 83 CC) were genotyped by two PCRs-Reverse Blotting Hybridization strategies: i) Broad-Spectrum General Primers 5+/6+ and ii) PGMY9/11 PCRs. HPV16 was the most frequently found genotype in all histological grades, and increased with the severity of lesions from 14.5% in ≤ CIN1, 19.8% in CIN2, 51.5% in CIN3 to 65.1% in CC (p < 0.001). For the remaining HR-HPVs their frequency in CC did not increase when compared to less severe categories. The nonavalent vaccine HR-types ranked at the top in CC, the dominant ones being HPV16 and HPV45. HR-HPV single infection occurs, respectively, in 57.1% and 57.0% of ≤CIN1 and CIN2, increasing to 72.2% and 91.6% in CIN3 and CC (p<0.001). No association between age and HPV type was observed in CC, although the risk of HPV16 infection in CIN3 cases increased with age. Results confirm the relevance of HPV16 in the whole clinical spectrum, with a strong rise of its proportion in CIN3 and cancer. This information will be relevant in evaluating the impact of HPV vaccination, as a baseline against which to compare genotype changes in HPV type-specific distribution as vaccinated women participate in screening in LA region. Likewise, these data may help select the best HPV testing system for HPV-based efficient, affordable, and sustainable screening programmes.

Effects of eccentric, concentric and eccentric/concentric training on muscle function and mass, functional performance, cardiometabolic health, quality of life and molecular adaptations of skeletal muscle in COPD patients: a multicentre randomised trial.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is the third cause of death worldwide. COPD is characterised by dyspnoea, limited exercise tolerance, and muscle dysfunction. Muscle dysfunction has been linked to dysregulation between muscle protein synthesis, myogenesis and degradation mechanisms. Conventional concentric cycling has been shown to improve several clinical outcomes and reduce muscle wasting in COPD patients. Eccentric cycling is a less explored exercise modality that allows higher training workloads imposing lower cardio-metabolic demand during exercise, which has shown to induce greater muscle mass and strength gains after training. Interestingly, the combination of eccentric and concentric cycling training has scarcely been explored. The molecular adaptations of skeletal muscle after exercise interventions in COPD have shown equivocal results. The mechanisms of muscle wasting in COPD and whether it can be reversed by exercise training are unclear. Therefore, this study aims two-fold: (1) to compare the effects of 12 weeks of eccentric (ECC), concentric (CONC), and combined eccentric/concentric (ECC/CONC) cycling training on muscle mass and function, cardiometabolic health, physical activity levels and quality of life in severe COPD patients; and (2) to examine the molecular adaptations regulating muscle growth after training, and whether they occur similarly in specific muscle fibres (i.e., I, IIa and IIx). METHODS: Study 1 will compare the effects of 12 weeks of CONC, ECC, versus ECC/CONC training on muscle mass and function, cardiometabolic health, levels of physical activity and quality of life of severe COPD patients using a multicentre randomised trial. Study 2 will investigate the effects of these training modalities on the molecular adaptations regulating muscle protein synthesis, myogenesis and muscle degradation in a subgroup of patients from Study 1. Changes in muscle fibres morphology, protein content, genes, and microRNA expression involved in skeletal muscle growth will be analysed in specific fibre-type pools. DISCUSSION: We aim to demonstrate that a combination of eccentric and concentric exercise could maximise the improvements in clinical outcomes and may be ideal for COPD patients. We also expect to unravel the molecular mechanisms underpinning muscle mass regulation after training in severe COPD patients. TRIAL REGISTRY: Deutshches Register Klinischer Studien; Trial registration: DRKS00027331; Date of registration: 12 January 2022. https://www.drks.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00027331 .

SARS-CoV-2 Variants in Paraguay: Detection and Surveillance with an Economical and Scalable Molecular Protocol.

SARS-CoV-2 variant detection relies on resource-intensive whole-genome sequencing methods. We sought to develop a scalable protocol for variant detection and surveillance in Paraguay, pairing rRT-PCR for spike mutations with Nanopore sequencing. A total of 201 acute-phase nasopharyngeal samples were included. Samples were positive for the SARS-CoV-2 N2 target and tested with the Spike SNP assay to detect mutations associated with the following variants: alpha (501Y), beta/gamma (417variant/484K/501Y), delta (452R/478K), and lambda (452Q/490S). Spike SNP calls were confirmed using amplicon (Sanger) sequencing and whole-genome (Nanopore) sequencing on a subset of samples with confirmed variant lineages. Samples had a mean N2 Ct of 20.8 (SD 5.6); 198/201 samples (98.5%) tested positive in the Spike SNP assay. The most common genotype was 417variant/484K/501Y, detected in 102/198 samples (51.5%), which was consistent with the P.1 lineage (gamma variant) in Paraguay. No mutations (K417 only) were found in 64/198 (32.3%), and K417/484K was identified in 22/198 (11.1%), consistent with P.2 (zeta). Seven samples (3.5%) tested positive for 452R without 478K, and one sample with genotype K417/501Y was confirmed as B.1.1.7 (alpha). The results were confirmed using Sanger sequencing in 181/181 samples, and variant calls were consistent with Nanopore sequencing in 29/29 samples. The Spike SNP assay could improve population-level surveillance for mutations associated with SARS-CoV-2 variants and inform the judicious use of sequencing resources.

Exacerbación de las inequidades educativas en tiempos de Covid-19.

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How to stay together? Habitat use by three sympatric sharks in the western coast of Baja California Sur, Mexico.

Sharks are top predators and play an important role in the regulation of marine ecosystems at lower trophic position. Mustelus californicus, Sphyrna zygaena, and Isurus oxyrinchus prove to be important fishery resources along the western coast of Baja California Sur and cohabit the same coastal areas, probably sharing resources. However, our knowledge about ecological dynamics of multiple species coexisting and sharing similar habitat resources is still limited, particularly for predators such as sharks. Therefore, this study focuses on the analysis of trophic ecology of the sharks species, using carbon (13C) and nitrogen (15N) stable isotope values in muscle tissues coupled with trace element concentration (Hg, Se, and Cd) in muscle and hepatic tissues of sharks. The values of δ13C (M. californicus -17.3 ± 1.1‰, S. zygaena -17.9 ± 0.5‰, and I. oxyrinchus -18.3 ± 0.3‰) and δ15N (M. californicus 18.2 ± 1.1‰, S. zygaena 18.4 ± 0.9‰, and I. oxyrinchus 17.8 ± 1.1‰) indicated that these species feed in the Gulf of Ulloa all throughout the year, and for extended periods with similar habitat use and trophic niche. The above-mentioned statement is also a conclusion supported by the significant correlation between isotopic and trace element concentrations in the muscular tissues in all studied species. Thus, the results of the present study emphasize the habitat and niche characteristics of three sympatric sharks off the coast of Baja California Sur, Mexico.

Mercury, selenium and cadmium in juvenile blue (Prionace glauca) and smooth hammerhead (Sphyrna zygaena) sharks from the Northwest Mexican Pacific coast.

Cadmium, selenium, and mercury concentrations were measured in muscle and liver of juvenile blue (Prionace glauca) and smooth hammerhead (Sphyrna zygaena) sharks caught on the west coast of Baja California Sur, Mexico, to evaluate the human health risk associated with its consumption. Cd and Hg were lower than the maximum allowable limit for human consumption established by the Mexican government (Hg = 1.0 µg g-1 and Cd = 0.50 µg g-1). Interspecific differences in trace elements accumulation denoted diet variations and physiological requirements of each shark species. Calculated biomagnification factor (BMF) values confirmed a prey-predator trophic transfer of elements. Not significant results of Selenium health benefit Index value (P. glauca = -0.46; S. zygaena = -0.02) signify no potential risks for human health. However, calculated Hazard Index values displayed possible health hazards to the children who consume blue shark meat regularly. The local population is advised regarding the ingestion rates of shark.

Ecophysiological responses and self-protective canopy effects of surfgrass (Phyllospadix torreyi) in the intertidal.

Intertidal seagrasses are subjected to desiccation and direct solar radiation during low tides. It is assumed that the canopy structure can self-protect the underlying shoots during these events, although there is no evidence on a physiological basis. The physiological responses of the surfgrass Phyllospadix torreyi were examined when emerged during low tide, on i) shoots overlaying the canopy, and ii) shoots sheltered within the canopy. Leaf water potential and water content decreased in external leaves after emersion, and the higher concentration of organic osmolytes reflected osmoregulation. Additionally, these shoots also exhibited a drastic reduction in carbohydrates after re-immersion, likely from cellular damage. Lipid peroxidation and antioxidant activity increments were also detected, while photosynthetic efficiency strongly diminished from direct exposure to solar radiation. Conversely, the sheltered shoots did not dehydrate and solely accumulated some oxidative stress, likely resulting from the warming of the canopy. In conclusion, the leaf canopy structure buffers physiological stress in the sheltered shoots, thus acting as a self-protective mechanism to cope with emersion.

Revisiting the dengue epidemic of 2011 in Paraguay: molecular epidemiology of dengue virus in the Asuncion metropolitan area.

BACKGROUND: Dengue is one of the most important re-emerging viral diseases and the most common human arthropod-borne viral infection worldwide. Any of the four Dengue virus serotypes (DENV-1 to 4) can cause asymptomatic infections or clinical manifestations that range in severity from a mild, self-limited illness, to a severe disease characterized by a shock syndrome that can lead to death. Paraguay suffers periodic epidemic outbreaks of dengue since 1988 when the DENV-1 was introduced in the country. Epidemics caused by all four serotypes have been reported and the country. Although dengue is endemic in Paraguay, few studies have described the molecular epidemiology of DENV in the country, which is important to understand the local and global spread, as well as the evolution of this pathogen. METHODS: This was a cross-sectional study of a convenience sample. Suspected dengue patients of any age were recruited from the Emergency Laboratory of the Central Hospital of the Institute of Social Welfare, Asuncion, Paraguay, from February to June of 2011. A DENV antigen test was used to confirm the infection. The protein E gene sequences of isolated viruses were sequenced for phylogenetic analysis. RESULTS: Dengue was confirmed in 55.1% of the participants (n = 98/178). The most frequent clinical findings were fever, headache, and myalgia. Identity analyses of the protein E gene sequence of 56 viruses isolated showed the circulation of DENV-1 (n = 45) and DENV-2 (n = 11) in the Asuncion metropolitan area in 2011. Molecular epidemiology analyses suggest that DENV-1 was introduced into Paraguay from Argentina, while the DENV-2 from Brazil, replacing previous virus lineages. CONCLUSIONS: We have analyzed the molecular epidemiology of DENV-1 and DENV-2 isolated in Paraguay in 2011. We found strong evidence that DENV-1 was introduced into Paraguay from Argentina, while the DENV-2 from Brazil, replacing previous virus lineages. Molecular epidemiology studies are of great interest to analyze the dynamic of DENV spread, which are useful for early implementation of containment measures to reduce the risk of explosive epidemics caused by this virus.