Plant reproduction research in Latin America: Toward sustainable agriculture in a changing environment.

Food production and food security depend on the ability of crops to cope with anthropogenic climate change and successfully produce seed. To guarantee food production well into the future, contemporary plant scientists in Latin America must carry out research on how plants respond to environmental stressors such as temperature, drought, and salinity. This review shows the opportunities to apply these results locally and abroad and points to the gaps that still exist in terms of reproductive processes with the purpose to better link research with translational work in plant breeding and biotechnology. Suggestions are put forth to address these gaps creatively in the face of chronic low investment in science with a focus on applicability.

Evidence of scale-free clusters of vegetation in tropical rainforests.

Tropical rainforests exhibit a rich repertoire of spatial patterns emerging from the intricate relationship between the microscopic interaction between species. In particular, the distribution of vegetation clusters can shed much light on the underlying process that regulates the ecosystem. Analyzing the distribution of vegetation clusters at different resolution scales, we show the first robust evidence of scale-invariant clusters of vegetation, suggesting the coexistence of multiple intertwined scales in the collective dynamics of tropical rainforests. We use field data and computational simulations to confirm our hypothesis, proposing a predictor that could be particularly interesting to monitor the ecological resilience of the world's "green lungs."

Early Cretaceous lepidosaur (sphenodontian?) burrows.

Scarce fossil tetrapod burrows have been recorded in Cretaceous rocks, which is probably linked to the dominant equable climates that existed for most of this period. The occurrence of Cretaceous tetrapod burrows from Patagonia (Chubut Province, Argentina) dated between 118 and 115 million years ago, gives insights into their paleoecology and paleoenvironment. The rocks containing the tetrapod burrows are of pyroclastic origin and represent eolian dunes and ash-fall deposits, some reworked by fluvial currents and others showing soil development. Fossil burrow casts preserved in a paleosol are composed by a ramp with a slightly curved or straight path in plan-view and lacking bifurcation, a rounded termination with no enlargement, showing a reniform cross-section, and are assigned to the ichnospecies Reniformichnus katikatii. The strongly flattened cross-sectional shape of the burrow casts and comparison with modern lizard burrows suggest that the producers were lepidosaurs (body mass = 50-323 g). Among Cretaceous fossorial lepidosaurs from Patagonia, the best candidate is an eilenodontine sphenodontian. Sphenodontians burrowed in the fossil soils where also arthropods, earthworms and shrubby plants thrived. The rare occurrence of tetrapod burrows in Cretaceous rocks is linked to stressing conditions related to frequent arrival of volcanic ash and a semiarid seasonal climate.

Polineuropatía por amiloidosis por transtiretina de inicio tardío. Caso clínico / Late-onset hereditary transthyretin amyloidosis with polyneuropathy. Report of one case

Hereditary transthyretin amyloidosis is a multisystemic autosomal dominant genetic disorder characterized by progressive distal sensory-motor polyneuropathy or restrictive cardiomyopathy, secondary to amyloid deposits. Its pathogenesis lies in the TTR gene mutation, and the Val50Met mutation is the most frequent. Patients have significant differences in the onset and severity of clinical presentation according to their country of origin. The diagnosis of this pathology is complex, even more in countries where it is not considered endemic. However, early suspicion and management are essential to improve survival and avoid unnecessary diagnostic and therapeutic strategies. We report a 69-year-old woman who presented a sensory-motor polyneuropathy, predominantly sensory, associated with distal neuropathic pain and bilateral vitritis. The history of her Italian father with polyneuropathy of unspecified etiology stood out. A vitreous biopsy identified amyloid substance deposits (congo red positive). These were also confirmed on a superficial peroneal nerve biopsy. During the etiological study of her polyneuropathy, an increased Kappa/Lambda index of 2.55 mg/L stood out. Therefore, light chain amyloidosis was suspected, and chemotherapy treatment was indicated without favorable response. After 10 years of progressive neurological and ophthalmological involvement, a genetic study confirmed the first case of late-onset hereditary transthyretin amyloidosis Val50Met with polyneuropathy in Chile.

Advances and Perspectives for Polyploidy Breeding in Orchids.

The orchid market is a dynamic horticultural business in which novelty and beauty command high prices. The two main interests are the development of flowers, from the miniature to the large and showy, and their fragrance. Overall organ size might be modified by doubling the chromosome number, which can be accomplished by careful study of meiotic chromosome disjunction in hybrids or species. Meiosis is the process in which diploid (2n) pollen mother cells recombine their DNA sequences and then undergo two rounds of division to give rise to four haploid (n) cells. Thus, by interfering in chromosome segregation, one can induce the development of diploid recombinant cells, called unreduced gametes. These unreduced gametes may be used for breeding polyploid progenies with enhanced fertility and large flower size. This review provides an overview of developments in orchid polyploidy breeding placed in the large context of meiotic chromosome segregation in the model plants Arabidopsis thaliana and Brassica napus to facilitate molecular translational research and horticultural innovation.

Effects of the economic recession on suicide mortality in Brazil: interrupted time series analysis.

OBJECTIVES: to analyze trends in suicide rates in Brazil in the period before and after the start of the economic recession. METHODS: interrupted time series research using national suicide data recorded in the period between 2012 and 2017 with socioeconomic subgroups analyses. Quasi-Poisson regression model was employed to analyze trends in seasonally adjusted data. RESULTS: there was an abrupt increase in the risk of suicide after economic recession in the population with less education (12.5%; RR = 1.125; 95%CI: 1.027; 1.232) and in the South Region (17.7%; 1.044; 1.328). After an abrupt reduction, there was a progressive increase in risk for the black and brown population and for those with higher education. In most other population strata, there was a progressive increase in the risk of suicide. CONCLUSIONS: the Brazilian economic recession caused different effects on suicide rates, considering social strata, which requires health strategies and policies that are sensitive to the most vulnerable populations.

The broad edge of synchronization: Griffiths effects and collective phenomena in brain networks.

Many of the amazing functional capabilities of the brain are collective properties stemming from the interactions of large sets of individual neurons. In particular, the most salient collective phenomena in brain activity are oscillations, which require the synchronous activation of many neurons. Here, we analyse parsimonious dynamical models of neural synchronization running on top of synthetic networks that capture essential aspects of the actual brain anatomical connectivity such as a hierarchical-modular and core-periphery structure. These models reveal the emergence of complex collective states with intermediate and flexible levels of synchronization, halfway in the synchronous-asynchronous spectrum. These states are best described as broad Griffiths-like phases, i.e. an extension of standard critical points that emerge in structurally heterogeneous systems. We analyse different routes (bifurcations) to synchronization and stress the relevance of 'hybrid-type transitions' to generate rich dynamical patterns. Overall, our results illustrate the complex interplay between structure and dynamics, underlining key aspects leading to rich collective states needed to sustain brain functionality. This article is part of the theme issue 'Emergent phenomena in complex physical and socio-technical systems: from cells to societies'.

Marginal speed confinement resolves the conflict between correlation and control in collective behaviour.

Speed fluctuations of individual birds in natural flocks are moderate, due to the aerodynamic and biomechanical constraints of flight. Yet the spatial correlations of such fluctuations are scale-free, namely they have a range as wide as the entire group, a property linked to the capacity of the system to collectively respond to external perturbations. Scale-free correlations and moderate fluctuations set conflicting constraints on the mechanism controlling the speed of each agent, as the factors boosting correlation amplify fluctuations, and vice versa. Here, using a statistical field theory approach, we suggest that a marginal speed confinement that ignores small deviations from the natural reference value while ferociously suppressing larger speed fluctuations, is able to reconcile scale-free correlations with biologically acceptable group's speed. We validate our theoretical predictions by comparing them with field experimental data on starling flocks with group sizes spanning an unprecedented interval of over two orders of magnitude.

[Late-onset hereditary transthyretin amyloidosis with polyneuropathy. Report of one case]. / Polineuropatía por amiloidosis por transtiretina de inicio tardío. Caso clínico.

Hereditary transthyretin amyloidosis is a multisystemic autosomal dominant genetic disorder characterized by progressive distal sensory-motor polyneuropathy or restrictive cardiomyopathy, secondary to amyloid deposits. Its pathogenesis lies in the TTR gene mutation, and the Val50Met mutation is the most frequent. Patients have significant differences in the onset and severity of clinical presentation according to their country of origin. The diagnosis of this pathology is complex, even more in countries where it is not considered endemic. However, early suspicion and management are essential to improve survival and avoid unnecessary diagnostic and therapeutic strategies. We report a 69-year-old woman who presented a sensory-motor polyneuropathy, predominantly sensory, associated with distal neuropathic pain and bilateral vitritis. The history of her Italian father with polyneuropathy of unspecified etiology stood out. A vitreous biopsy identified amyloid substance deposits (congo red positive). These were also confirmed on a superficial peroneal nerve biopsy. During the etiological study of her polyneuropathy, an increased Kappa/Lambda index of 2.55 mg/L stood out. Therefore, light chain amyloidosis was suspected, and chemotherapy treatment was indicated without favorable response. After 10 years of progressive neurological and ophthalmological involvement, a genetic study confirmed the first case of late-onset hereditary transthyretin amyloidosis Val50Met with polyneuropathy in Chile.

Effects of the economic recession on suicide mortality in Brazil: interrupted time series analysis / Efectos de la recesión económica en la mortalidad por suicidio en Brasil: análisis de series de tiempo interrumpido / Efeitos da recessão econômica na mortalidade por suicídio no Brasil: análise com séries temporais interrompidas

ABSTRACT Objectives: to analyze trends in suicide rates in Brazil in the period before and after the start of the economic recession. Methods: interrupted time series research using national suicide data recorded in the period between 2012 and 2017 with socioeconomic subgroups analyses. Quasi-Poisson regression model was employed to analyze trends in seasonally adjusted data. Results: there was an abrupt increase in the risk of suicide after economic recession in the population with less education (12.5%; RR = 1.125; 95%CI: 1.027; 1.232) and in the South Region (17.7%; 1.044; 1.328). After an abrupt reduction, there was a progressive increase in risk for the black and brown population and for those with higher education. In most other population strata, there was a progressive increase in the risk of suicide. Conclusions: the Brazilian economic recession caused different effects on suicide rates, considering social strata, which requires health strategies and policies that are sensitive to the most vulnerable populations.

RESUMEN Objetivos: analizar tendencias de tasas de suicidio en Brasil, antes y después del inicio de la recesión económica. Métodos: estudio de series de tiempo interrumpido utilizando datos nacionales de suicidio registrados entre 2012 y 2017 con análisis por subgrupos socioeconómicos. Modelo de regresión quasi-Poisson empleado para analizar tendencias de datos ajustados estacionalmente. Resultados: observado aumento abrupto en el riesgo de suicidio pos recesión económica en la población con menor escolaridad (12,5%; RR = 1,125; IC95%:1,027; 1,232) y en la Región Sur (17,7%; 1,044; 1,328). Pos reducción abrupta, ocurrió aumento progresivo en el riesgo para la población de negros y pardos y de mayor escolaridad. En la mayoría de los demás estratos poblacionales, verificado aumento progresivo en el riesgo de suicidio. Conclusiones: la recesión económica brasileña produzco efectos diferentes en las tasas de suicidio, considerando los estratos sociales, lo que demanda estrategias de salud y políticas sensibles a poblaciones más vulnerables.

RESUMO Objetivos: analisar as tendências nas taxas de suicídio no Brasil, no período antes e depois do início da recessão econômica. Métodos: estudo de séries temporais interrompidas utilizando dados nacionais de suicídio registrados no período entre 2012 e 2017 com análises por subgrupos socioeconômicos. Modelo de regressão quasi-Poisson foi empregado para analisar as tendências dos dados ajustados sazonalmente. Resultados: observou-se aumento abrupto no risco de suicídio após recessão econômica na população com menor escolaridade (12,5%; RR = 1,125; IC95%:1,027; 1,232) e na Região Sul (17,7%; 1,044; 1,328). Após redução abrupta, ocorreu aumento progressivo no risco para a população de pretos e pardos e na de maior escolaridade. Na maioria dos demais estratos populacionais, verificou-se aumento progressivo no risco de suicídio. Conclusões: a recessão econômica brasileira produziu efeitos diferentes nas taxas de suicídio, considerando os estratos sociais, o que demanda estratégias de saúde e políticas sensíveis às populações mais vulneráveis.

Emergent spatial patterns of coexistence in species-rich plant communities.

Statistical physics has proved essential to analyze multiagent environments. Motivated by the empirical observation of various nonequilibrium features in Barro Colorado and other ecological systems, we analyze a plant-species abundance model of neutral competition, presenting analytical evidence of scale-invariant plant clusters and nontrivial emergent modular correlations. Such first theoretical confirmation of a scale-invariant region, based on percolation processes, reproduces the key features in natural rainforest ecosystems and can confer the most stable equilibrium for ecosystems with vast biodiversity.

Geographical Variability in Mortality in Urban Areas: A Joint Analysis of 16 Causes of Death.

The geographical distribution of mortality has frequently been studied. Nevertheless, those studies often consider isolated causes of death. In this work, we aim to study the geographical distribution of mortality in urban areas, in particular, in 26 Spanish cities. We perform an overall study of 16 causes of death, considering that their geographical patterns could be dependent and estimating the dependence between the causes of death. We study the deaths in these 26 cities during the period 1996-2015 at the census tract level. A multivariate disease mapping model is used in order to solve the potential small area estimation problems that these data could show. We find that most of the geographical patterns found show positive correlations. This suggests the existence of a transversal geographical pattern, common to most causes of deaths, which determines those patterns to a higher/lower extent depending on each disease. The causes of death that exhibit that underlying pattern in a more prominent manner are chronic obstructive pulmonary disease (COPD), lung cancer, and cirrhosis for men and cardiovascular diseases and dementias for women. Such findings are quite consistent for most of the cities in the study. The high positive correlation found between geographical patterns reflects the existence of both high and low-risk areas in urban settings, in general terms for nearly all the causes of death. Moreover, the high-risk areas found often coincide with neighborhoods known for their high deprivation. Our results suggest that dependence among causes of death is a key aspect to be taken into account when mapping mortality, at least in urban contexts.

The Role of Structural Maintenance of Chromosomes Complexes in Meiosis and Genome Maintenance: Translating Biomedical and Model Plant Research Into Crop Breeding Opportunities.

Cohesin is a multi-unit protein complex from the structural maintenance of chromosomes (SMC) family, required for holding sister chromatids together during mitosis and meiosis. In yeast, the cohesin complex entraps sister DNAs within tripartite rings created by pairwise interactions between the central ring units SMC1 and SMC3 and subunits such as the α-kleisin SCC1 (REC8/SYN1 in meiosis). The complex is an indispensable regulator of meiotic recombination in eukaryotes. In Arabidopsis and maize, the SMC1/SMC3 heterodimer is a key determinant of meiosis. In Arabidopsis, several kleisin proteins are also essential: SYN1/REC8 is meiosis-specific and is essential for double-strand break repair, whereas AtSCC2 is a subunit of the cohesin SCC2/SCC4 loading complex that is important for synapsis and segregation. Other important meiotic subunits are the cohesin EXTRA SPINDLE POLES (AESP1) separase, the acetylase ESTABLISHMENT OF COHESION 1/CHROMOSOME TRANSMISSION FIDELITY 7 (ECO1/CTF7), the cohesion release factor WINGS APART-LIKE PROTEIN 1 (WAPL) in Arabidopsis (AtWAPL1/AtWAPL2), and the WAPL antagonist AtSWITCH1/DYAD (AtSWI1). Other important complexes are the SMC5/SMC6 complex, which is required for homologous DNA recombination during the S-phase and for proper meiotic synapsis, and the condensin complexes, featuring SMC2/SMC4 that regulate proper clustering of rDNA arrays during interphase. Meiotic recombination is the key to enrich desirable traits in commercial plant breeding. In this review, I highlight critical advances in understanding plant chromatid cohesion in the model plant Arabidopsis and crop plants and suggest how manipulation of crossover formation during meiosis, somatic DNA repair and chromosome folding may facilitate transmission of desirable alleles, tolerance to radiation, and enhanced transcription of alleles that regulate sexual development. I hope that these findings highlight opportunities for crop breeding.

Fanconi anemia ortholog FANCM regulates meiotic crossover distribution in plants.

Meiotic recombination increases genetic diversity and manipulation of its frequency and distribution holds great promise in crop breeding. In Arabidopsis thaliana, FANCM (a homolog of mammalian Fanconi anemia complementation group M) suppresses recombination and its function seems conserved in other species including the rosids Brassica spp. and pea (Pisum sativum), and the monocot rice (Oryza sativa). To examine the role of FANCM during meiotic recombination in lettuce (Lactuca sativa, an asterid), we characterized the function of lettuce LsFANCM and found that it can functionally substitute for AtFANCM in transgenic Arabidopsis plants. Moreover, three independent CRISPR/Cas9-edited lettuce Lsfancm mutants showed reduced pollen viability and seed setting. Unexpectedly, analyses of chromosome behavior revealed that 77.8% of Lsfancm meiocytes exhibited univalents. The normal formation of double-strand breaks in DNA and the discontinuous assembly of synaptonemal complex in Lsfancm mutants supports the hypothesis that LsFANCM might be dispensable for the initiation of meiotic recombination but required for normal synapsis. Furthermore, the frequency of lettuce HEI10 (Human Enhancer of Invasion 10) foci, a marker for Class-I crossovers (COs), was similar between wild-type (WT) and Lsfancm. Strikingly, the distribution of LsHEI10 foci and chiasmata in Lsfancm meiotic chromosomes was markedly different from the WT. A similar alteration in the distribution of Class-I COs was also observed in the Arabidopsis Atfancm mutant. Taken together, these results demonstrate that FANCM is important for shaping the distribution of meiotic Class-I COs in plants, and reveal an evolutionarily divergent role for FANCM in meiotic bivalent formation between Arabidopsis and lettuce.

[Association between neighborhood walkability and mortality due to different causes in Andalusia (Spain)]. / Asociación entre la caminabilidad del barrio de residencia y la mortalidad por distintas causas en Andalucía.

OBJECTIVE: To describe the association between the Neighborhood Walkability and mortality. METHOD: Ecological study of small areas. The standardized mortality ratios (SMR) and the Walk Score© were calculated in each census tract. These values were compared with parametric and nonparametric tests. RESULTS: For men, in the case of ischemic diseases, the means of the SMR for the categories with the highest walkability and the least were 1.03 and 0.85 (p <0.01), and in chronic obstructive pulmonary disease (COPD) were 1,009 and 1.20 (p <0.01). In women, the means of the SMR for diabetes were 0.97 and 1.2 (p <0.01), for ischemic diseases were 1.01 and 1.12 (p <0.01), for cerebrovascular diseases were 1.007 and 1.18 (p <0.01), for COPD were 1.01 and 1.49 (p <0.01) and for all causes were 1.006 and 1.08 (p <0.01) CONCLUSIONS: Behavior about walking in the activities of daily life is different between sexes. Living in walkable neighborhoods is a protective factor for women.

[Predictive models of the COVID-19 epidemic in Spain with Gompertz curves]. / Modelos predictivos de la epidemia de COVID-19 en España con curvas de Gompertz.

During the international health crisis caused by the COVID-19 pandemic, it is necessary not only to know the data on infections, deaths and the occupation of hospital beds, but also to make predictions that help health authorities in the management of the crisis. The present work aims to describe the methodology used to develop predictive models of infections and deaths for the COVID-19 epidemic in Spain, based on Gompertz curves. The methodology is applied to the country as a whole and to each of its Autonomous Communities. Based on the official data available on the date of this work, and through the models described, we estimate a total of around 240.000 infected and 25.000 deaths at the end of the epidemic. At a national level, we forecast the end of the epidemic between June and July 2020.

Effect of the Financial Crisis on Socioeconomic Inequalities in Mortality in Small Areas in Seven Spanish Cities.

BACKGROUND: The aim of this study was to analyze the trend in socioeconomic inequalities in mortality in small areas due to several specific causes before (2001-2004, 2005-2008) and during (2009-2012) the economic crisis in seven Spanish cities. METHODS: This ecological study of trends, with census tracts as the areas of analysis, was based on three periods. Several causes of death were studied. A socioeconomic deprivation index was calculated for each census tract. For each small area, we estimated standardized mortality ratios, and controlled for their variability using Bayesian models (sSMR). We also estimated the relative risk of mortality according to deprivation in the different cities, periods, and sexes. RESULTS: In general, a similar geographical pattern was found for the socioeconomic deprivation index and sSMR. For men, there was an association in all cities between the deprivation index and all-cause mortality that remained stable over the three periods. For women, there was an association in Barcelona, Granada, and Sevilla between the deprivation index and all-cause mortality in the third period. Patterns by causes of death were more heterogeneous. CONCLUSIONS: After the start of the financial crisis, socioeconomic inequalities in total mortality in small areas of Spanish cities remained stable in most cities, although several causes of death showed a different pattern.

Analysis of Meiosis in Nonmodel Tropical Plants: The Case of Carica papaya Linn.

To develop plants that are more tolerant to drought, marginal soil fertility, and diseases and that satisfy demands for high yield, new cultivars of the tropical fruit papaya (Carica papaya L.) are needed. Nonetheless, in many cases, these traits are available in only wild relatives found throughout Latin America. Understanding meiotic progression may facilitate the introgression of desirable traits into commercial cultivars that maintain high fertility. In this protocol, we describe a practical and simple method to effectively isolate male meiocytes in order to document the behavior of papaya meiotic chromosomes.