RESUMO

The global demand for agricultural commodities has driven extensive land conversion to agriculture in Brazil, especially in the MATOPIBA region. This area encompasses the Rio Grande Basin, a major tributary of the São Francisco Basin that is known for expanding intensive irrigated agriculture and hydropower generation. However, recent data reveal declining precipitation and aquifer recharge, potentially exacerbating ongoing water and land conflicts. This study investigates the long-term sustainability of agricultural expansion amid the worsening water scarcity using a system dynamics model. Findings suggest that rising costs and decreasing profits due to irrigation water shortages may hinder the expansion of irrigated land. By 2040, the irrigation demand may remain partly unmet, while downstream flow and baseflow could decrease. Additionally, agricultural expansion will significantly raise energy demand, posing a developmental challenge. We suggest that ensuring the sustainability of the Rio Grande Basin depends on improved water management and exploring alternative energy sources to address existing constraints.

RESUMO

The distribution of a species reflects its ecological adaptability and evolutionary history, which is shaped by the environment and represents a dynamic area subject to anthropogenic environmental change. We used the MaxEnt algorithm to construct ecological niche models for four thrush species within the Turdus genus; T. amaurochalinus, T. chiguanco, T. falcklandii and T. rufiventris. These models were used to predict the potential geographic distributions of these species that are expanding their ranges in South America. Using occurrence records, we estimated currently occupied areas for each species. We also identified suitable habitats and projected possible areas to be colonized by the four species at continental scale. Temperature annual range had the highest influence for T. falcklandii, while human modification was the main variable explaining the distribution of the other three species. The potential distribution area ranged from 2.5 million km2 for T. falcklandii to nearly seven million km2 for T. amaurochalinus. Large proportions of suitable area remain unoccupied by all four species, being 50% for T. amaurochalinus and T. rufiventris, and about 70% for T. chiguanco and T. falcklandii. Anthropogenic disturbances, such as habitat loss and ecosystem transformation, lead to non-random species extinction and biotic homogenization, highlighting the importance of predictive models as valuable tools for informing mitigation policies and conservation strategies. Thrushes are progressively expanding their ranges, and the colonization of new habitats could bring new challenges.

Assuntos

RESUMO

The genetic diversity found in natural populations is the result of the evolutionary forces in response to historical and contemporary factors. The environmental characteristics and geological history of Mexico promoted the evolution and diversification of plant species, including wild relatives of crops such as the wild pumpkins (Cucurbita). Wild pumpkin species are found in a variety of habitats, evidencing their capability to adapt to different environments. Despite the potential value of wild Cucurbita as a genetic reservoir for crops, there is a lack of studies on their genetic diversity. Cucurbita radicans is an endangered species threatened by habitat destruction leading to low densities in small and isolated populations. Here, we analyze Genotype by Sequencing genomic data of the wild pumpkin C. radicans to evaluate the influence of factors like isolation, demographic history, and the environment shaping the amount and distribution of its genetic variation. We analyzed 91 individuals from 14 localities along its reported distribution. We obtained 5,107 SNPs and found medium-high levels of genetic diversity and genetic structure distributed in four main geographic areas with different environmental conditions. Moreover, we found signals of demographic growth related to historical climatic shifts. Outlier loci analysis showed significant association with the environment, principally with precipitation variables. Also, the outlier loci displayed differential changes in their frequencies in response to future global climate change scenarios. Using the results of genetic structure, outlier loci and multivariate analyses of the environmental conditions, we propose priority localities for conservation that encompass most of the genetic diversity of C. radicans.

Assuntos

RESUMO

The reuse of by-products has become increasingly important as a means of minimising the consumption of natural resources and reducing waste disposal. This study examines the potential reuse of steel slag for soil stabilisation, with benefits such as conserving natural resources and mitigating the greenhouse gas emissions associated with the production of conventional stabilising agents. It focuses on evaluating the effect of pozzolanic reactions on the strength and stiffness of both loess silt and silt-bentonite mixtures. The experimental tests included the physical characterisation of granular materials, reactivity tests of the pozzolanicity of soil mixtures, compaction tests, unconfined compression tests, and hydraulic conductivity tests. The impact of the curing period was also analysed to quantify the effects of natural cementation and the development of hydrogels within soil pores on the compacted soil properties. The findings suggest that adding steel slag can significantly increase the strength and the stiffness of compacted loess silts by over 300% and 500%, respectively, after 56 days of curing, substantially reducing the hydraulic conductivity of granular materials, such as the tested silt, as hydrogels partially occupy the pores available for liquid flow. It should be noted that the chemical reactions during hydrogel formation may hinder the free expansion of clay mixtures and release Ca2+ ions, thereby counteracting the expected reduction in hydraulic conductivity when bentonite is added to compacted earthen barriers.

RESUMO

La deficiencia transversal del maxilar es una anomalía dentomaxilar capaz de producir problemas funcionales en la oclusión, respiración y estéticos. Su presentación clínica tradicional es la mordida cruzada posterior y una alteración en la relación transversal intermaxilar, la cual impide la correcta erupción de las piezas dentarias. Su manejo corresponde a la expansión rápida del maxilar, la cual puede ser asistida mediante mini-implantes (MARPE), cirugía (SARPE) o una combinación de ambas técnicas (MISMARPE). El objetivo del presente artículo es presentar un contraste entre las técnicas empleadas en la expansión rápida del maxilar, para simplificar la toma de decisiones clínicas. Se elaboró una revisión narrativa en las bases de datos PubMed, Scopus y Epistemonikos contemplando revisiones sistemáticas, metaanálisis, ensayos clínicos aleatorizados y estudios observacionales publicados entre el año 2013 a 2023. Un total de 23 artículos fueron incluidos, los cuales cumplían con los criterios de inclusión y exclusión establecidos. El manejo clínico de la deficiencia transversal del maxilar frecuentemente requiere un abordaje interdisciplinario combinando un enfoque ortopédico y quirúrgico. Según lo encontrado en la actual revisión, tanto el MARPE, SARPE y MISMARPE reportan indicaciones y limitaciones, así como complicaciones asociadas, sin embargo, serían efectivas en la resolución de deficiencias transversales. Se recomienda al clínico considerar dicha información de acuerdo a las necesidades particulares de cada caso clínico, así como profundizar y prolongar el estudio de nuevas técnicas para analizar su estabilidad a largo plazo en comparación a las otras corrientes terapéuticas.

The transverse deficiency of the maxilla is a dentomaxillary anomaly capable of producing functional problems in occlusion, respiration and esthetics. Its traditional clinical presentation is dental crowding, which obstructs the correct eruption of the teeth. Its management corresponds to rapid maxillary expansion, which can be assisted by means of mini-implants (MARPE), surgery (SARPE) or a combination of both techniques (MISMARPE). The objective of this article is to present a contrast between the techniques used in rapid maxillary expansion to simplify clinical decision making. A narrative review was performed in PubMed, Scopus and Epistemonikos databases, including systematic reviews, meta-analyses, randomized clinical trials and observational studies published between 2013 and 2023. A total of 23 articles were included, which met the established inclusion and exclusion criteria. The clinical management of transverse deficiency of the maxilla frequently requires an interdisciplinary management, combining an orthopedic and surgical approach. As found in the current review, all techniques; MARPE, SARPE and MISMARPE, report indications and limitations, as well as associated complications. It is recommended to deepen and prolong the study of new techniques in order to analyze their long-term stability in comparison to other therapeutic currents.

RESUMO

OBJECTIVES: To synthesise the dentoalveolar, periodontal and skeletal changes that occur when using maxillary expansion techniques assisted by temporary anchorage devices compared to conventional protocols. METHODS: Five databases and grey literature were consulted, up to December 2023, focusing on intervention designs and excluding other type of studies. The quality assessment was conducted by using the adaptation for orthodontics of the CONSORT statement, the guidelines for reporting non-randomised studies, the RoB-2 tool, and the ROBINS-I tool. A descriptive summary and meta-analysis using RevMan 5.4 were performed. RESULTS: Nine clinical trials were included (n=377 patients, mean age 13.2±0.6) with a diagnosis of transverse maxillary deficiency. The analysed studies showed qualitative dentoalveolar and periodontal changes after expansion, which were greater on the maxillary first premolars in tooth-borne appliances. Meta-analyses for some effects were included from two studies (n=64); patients who used tooth-borne appliances had greater effects of buccal intercoronal width between the premolars with statistically significant differences (Std Mean difference 2.34; 95% CI: 0.04-4.65 p=0.05). Conversely, those patients who used bone-borne or hybrid appliances had greater effects of buccal intercoronal width between molars with statistically significant differences (Std Mean difference -0.64; 95% CI: -1.38-0.10; p=0.09). CONCLUSIONS: According to the studies analysed, all measurements increased in the intervention groups after expansion. Quantitative analyses show different findings at dentoalveolar level when tooth-borne, bone-borne or hybrid appliances are considered. Nevertheless, the results should be taken with caution due to the heterogeneity of the studies. The protocol was registered at PROSPERO (CRD42021283170), with no funding to report.

Assuntos

RESUMO

BACKGROUND AND AIMS: Pleistocene climatic oscillations, characterized by arid (interglacial) and pluvial (glacial) phases, have profoundly impacted the floras of Mediterranean climates. Our study investigates the hypothesis that these climatic extremes have promoted phases of range expansion and contraction in the Eriosyce sect. Neoporteria, resulting in pronounced genetic structuring and restricted gene flow. METHODS: Utilizing nuclear microsatellite markers, we genotyped 251 individuals across 18 populations, encompassing all 14 species and one subspecies within the Eriosyce sect. Neoporteria. Additionally, Species Distribution Models (SDMs) were employed to reconstruct past (Last Interglacial, Last Glacial Maximum, Mid-Holocene) and current potential distribution patterns, aiming to delineate the climatic influences on species' range dynamics. KEY RESULTS: The gene flow analysis disclosed disparate levels of genetic interchange among species, with marked restrictions observed between entities that are geographically or ecologically separated. Notably, E. subgibbosa from Hualpen emerged as genetically distinct, warranting its exclusion for clearer genetic clustering into north, central, and south clusters. The SDMs corroborated these findings, showing marked range expansions during warmer periods and contractions during colder times, indicating significant shifts in distribution patterns in response to climatic changes. CONCLUSIONS: Our findings emphasize the critical role of Pleistocene climatic fluctuations in driving the dynamic patterns of range expansions and contractions that have led to geographic isolation and speciation within the Eriosyce sect. Neoporteria. Even in the face of ongoing gene flow, these climate-driven processes have played a pivotal role in sculpting the species' genetic architecture and diversity. This study elucidates the complex interplay between climatic variability and evolutionary dynamics among Mediterranean cacti in central Chile, highlighting the necessity of considering historical climatic millenial oscillations in conservation and evolutionary biology studies.

RESUMO

Landscapes are consistently under pressure from human-induced ecological change, often resulting in shifting species distributions. For some species, changing the geographical breadth of their niche space results in matching range shifts to regions other than those in which they are formally found. In this study, we employ a population genomics approach to assess potential conservation issues arising from purported range expansions into the south Texas Brush Country of two sister species of ducks: mottled (Anas fulvigula) and Mexican (Anas diazi) ducks. Specifically, despite being non-migratory, both species are increasingly being recorded outside their formal ranges, with the northeastward and westward expansions of Mexican and mottled ducks, respectively, perhaps resulting in secondary contact today. We assessed genetic ancestry using thousands of autosomal loci across the ranges of both species, as well as sampled Mexican- and mottled-like ducks from across overlapping regions of south Texas. First, we confirm that both species are indeed expanding their ranges, with genetically pure Western Gulf Coast mottled ducks confirmed as far west as La Salle county, Texas, while Mexican ducks recorded across Texas counties near the USA-Mexico border. Importantly, the first confirmed Mexican × mottled duck hybrids were found in between these regions, which likely represents a recently established contact zone that is, on average, ~100 km wide. We posit that climate- and land use-associated changes, including coastal habitat degradation coupled with increases in artificial habitats in the interior regions of Texas, are facilitating these range expansions. Consequently, continued monitoring of this recent contact event can serve to understand species' responses in the Anthropocene, but it can also be used to revise operational survey areas for mottled ducks.

Assuntos

RESUMO

The Vaupés River stands out as one of the few within the Amazon basin due to its numerous rapids. These riverine fast-flowing sections not only provide habitat to highly specialized fishes but also function as natural barriers hindering the movement of fish along its course. During a fish-collecting expedition in the lower Vaupés River basin in Colombia, 95 species were registered belonging to 30 families and seven orders. Despite recent inventories in the region, our comprehensive sampling efforts particularly focused on the rapids and associated rheophilic fauna, allowing us to contribute the first records of four fish species in Colombia (Mylopluslucienae Andrade, Ota, Bastos & Jégu, 2016, Tometesmakue Jégu, Santos & Jégu, 2002, also first record of the genus, Leptodoraspraelongus (Myers & Weitzman, 1956), and Eigenmanniamatintapereira Peixoto, Dutra & Wosiacki, 2015) and six presumably undescribed species (i.e., Jupiaba sp., Moenkhausia sp., Phenacogaster sp., Bunocephalus sp., Hemiancistrus sp., and Archolaemus sp.). In this study, a commented list of the ichthyofauna of these environments is presented, as well as a photographic catalog of fish species integrated into the CaVFish Project - Colombia.

RESUMO

OBJECTIVE: This retrospective study aims to assess the three-dimensional dentoskeletal effects and median palatal suture opening pattern in patients undergoing modified surgically assisted maxillary rapid expansion (SARME) without pterygoid plate detachment. METHODS: Twenty-eight patients submitted to modified SARME between 2009 and 2016 were retrospectively evaluated through cone-beam computed tomography (CBCT). Dental and skeletal measurements were taken at three different operative periods (before the expansion - T0; at the end of the activation of the Hyrax device - T1; and six months after the immobilization of the device - T2). Statistical analyses, including ANOVA and Pearson's correlation coefficient, were performed using SPSS software. RESULTS: SARME demonstrated significant transverse maxillary expansion (with an average of 6.05 mm) with a greater impact in the anterior region. Dental measurements, including canine and molar distances, exhibited significant changes over the operative periods. Bone measurements (ANS and PNS) presented small but significant alterations, including a slight inferior displacement of ANS during device activation. The nasal floor width increased, followed by a width reduction after immobilization. The median palatal suture predominantly exhibited a Type II (V-shaped) opening. CONCLUSION: The modified SARME presented a transversal direction increase and a super-lower skeletal displacement, with the anterior region being more affected than the posterior region. There was no change in the anteroposterior direction of the maxilla. Additionally, there was an increase in the linear dental measurements and a decrease in the angular measurement, with a positive correlation between the amount of posterior bone expansion and molar expansion as a result of the treatment in the analyzed period.

Assuntos