Unusual adult-onset cardiac rhabdomyomas in tuberous sclerosis complex: a case report.

Background: Tuberous sclerosis complex is a genetic neurocutaneous autosomal dominant syndrome, characterized by the development of multiple benign tumors (hamartomas) affecting various systems. Heart-benign tumors that result from the complex are called cardiac rhabdomyomas. Unlike hamartomas that occur in other organs, cardiac rhabdomyomas are most prevalent in infants and very young children with tuberous sclerosis complex. We present a case of a young adult with tuberous sclerosis who had an unusually late diagnosis of cardiac rhabdomyomas. Case report: A 22-year-old male patient of Afro-descendant, diagnosed with tuberous sclerosis complex in childhood, presented with refractory epilepsy and was treated only with lacosamide. The patient came to medical consultation due to a recent history of episodic, persistent chest pain in the sternal region, associated with physical effort. Echocardiography revealed a non-dilated left ventricle, with several rounded masses of high echogenicity without pedicles at the apical level, the largest measuring 14 × 11 mm, consistent with cardiac rhabdomyomas. Conclusion: Cardiac rhabdomyomas rarely develop in adulthood for individuals with tuberous sclerosis. These late-onset cases can exhibit various symptoms, from simple to complex presentations. Regular clinical checkups are essential for adults with tuberous sclerosis complex.

Factors associated with hepatitis B virus infection in indigenous communities of Colombia / Factores asociados con la infección por el virus de la hepatitis B en comunidades indígenas de Colombia.

Introduction. Colombia is home to 2 million indigenous people who live in conditions of poverty and with health deficiencies, making them vulnerable to contracting hepatitis B (HBV). Amazonas has a high virus prevalence, and there are barriers to accessing vaccination; thus, part of the population is susceptible to infection. Objective. To identify factors associated with HBV in Colombian indigenous people. Materials and Methods. A case-control study of people over 18 years from four departments of Colombia. Cases were identified through the national hepatitis B notification registry (2015-2022). Controls were selected and matched to cases (2:1) by age, sex, ethnicity, and department. Sociodemographic characteristics, factors associated with contact with body fluids, cultural practices, and vaccination history were identified by means of a survey. The ethics committee of the Universidad de Antioquia approved the project. Results. Seventy five cases and 150 controls from 13 ethnic groups were surveyed. Amazonas contributed 49% of participants, 83% were women, and the median age of cases was 30 years (IQ range: 27-37). The associated factors were a family history of hepatitis B [adjusted OR: 2.61 (95% CI: 1.09-6.27)] and, in women, the number of pregnancies [adjusted OR: 1.61 (95% CI 1.02- 2.54)]. The vaccination history showed a protective effect, but the association was not significant. Conclusion. Aspects associated with family life and unprotected sexual relations seem to be responsible for the potential transmission of the virus. It was not possible to identify associated cultural practices. Innovative and differential strategies are required for indigenous people to achieve a reduction of HBV.

Introducción. Colombia alberga dos millones de indígenas, que viven en condiciones de pobreza y tienen deficiencias en salud, por lo cual están expuestos a contraer infecciones virales como la hepatitis B. El departamento del Amazonas presenta una gran prevalencia del virus y barreras para acceder a la vacunación; por esto, parte de la población es propensa a la infección. Objetivo. Identificar factores asociados con la infección por el virus de la hepatitis B en indígenas colombianos. Materiales y métodos. Se llevó a cabo un estudio de casos y controles en mayores de 18 años de cuatro departamentos del país. Los casos se identificaron mediante el registro nacional de notificación de hepatitis B (2015-2022). Los controles seleccionados de manera concurrente fueron pareados con los casos por edad, sexo, etnia y departamento. En una encuesta se consignaron las características sociodemográficas, los factores asociados con el contacto con sangre y fluidos, las prácticas socioculturales y los antecedentes de vacunación. El proyecto fue aprobado por Comité de Ética de la Universidad de Antioquia. Resultados. Participaron 75 casos y 150 controles de 13 grupos étnicos. El departamento del Amazonas aportó el 49 % de los participantes (83 % mujeres) con una mediana de edad de 30 años (RIC = 27-37). Los factores asociados con una mayor probabilidad de contraer la infección fueron el antecedente de algún familiar infectado con el virus de la hepatitis B (OR ajustado = 2,61) (IC95%: 1,09-6,27) y número de embarazos en mujeres, (OR ajustado = 1,61) (IC95%: 1,02-2,54). La vacunación mostró un efecto protector sin asociación significativa. Conclusión. Los aspectos asociados con la convivencia familiar y el número de embarazos contribuyen a una potencial transmisión vertical y horizontal del virus. No se identificaron prácticas culturales asociadas. Se requieren estrategias novedosas y diferenciales para reducir la transmisión del virus de la hepatitis B en poblaciones indígenas.

Suppurative Thyroiditis: Coinfection by Nocardia spp. and Mycobacterium tuberculosis in an Immunocompromised Patient.

Suppurative thyroiditis is a rare entity with a low incidence in thyroid diseases, manifesting with pain, fever, dysphagia, and dysphonia. Its infrequency is explained by the thyroid gland's resistance to infections due to its encapsulated position, high blood flow, bactericidal action of iodine, and extensive lymphatic network. We present the first report in the literature of a 72-year-old woman with a history of inflammatory myopathy and immunosuppression diagnosed with suppurative thyroiditis co-infected with Nocardia spp. and Mycobacterium tuberculosis. This entity requires a high clinical suspicion, and fine-needle aspiration biopsy (FNAB) is preferred as the diagnostic method for microbiological sampling. Although rare, it carries high morbidity and mortality if not suspected in time.

Immobilised Inulinase from Aspergillus niger for Fructose Syrup Production: An Optimisation Model.

Fructose is a carbohydrate with essential applications in the food industry, mainly due to its high sweetness and low cost. The present investigation focused on optimising fructose production from commercial inulin using the enzymatic immobilisation method and applying the response surface methodology in a 12-run central composite design. The independent variables evaluated were the pH (-) and temperature (°C). The substrate consisted of a commercial inulin solution at a concentration of 1 g/L, while the catalyst consisted of the enzyme inulinase from Aspergillus niger (EC 232-802-3), immobilised in 2% m/v sodium alginate. A stirred vessel reactor was used for 90 min at 120 rpm, and quantification of reducing sugars was determined using DNS colorimetric and UV-Vis spectrophotometric methods at a 540 nm wavelength. After applying the response surface methodology, it was determined that the catalytic activity using the immobilisation method allows for a maximum total productivity of 16.4 mg/h under pH and temperature of 3.9 and 37 °C, respectively, with an efficiency of 96.4%. The immobilised enzymes' reusability and stability compared to free enzymes were evaluated, obtaining activity up to the fifth reuse cycle and showing significant advantages over the free catalyst.

Sonocatalytic Activity of Porous Carbonaceous Materials for the Selective Oxidation of 4-Hydroxy-3,5-dimethoxybenzyl Alcohol.

Selective oxidation, which is crucial in diverse chemical industries, transforms harmful chemicals into valuable compounds. Heterogeneous sonocatalysis, an emerging sustainable approach, urges in-depth exploration. In this work, we investigated N-doped or non-doped carbonaceous materials as alternatives to scarce, economically sensitive metal-based catalysts. Having synthesized diverse carbons using a hard-template technique, we subjected them to sonication at frequencies of 22, 100, 500, and 800 kHz with a 50% amplitude. Sonochemical reaction catalytic tests considerably increased the catalytic activity of C-meso (non-doped mesoporous carbon material). The scavenger test showed a radical formation when this catalyst was used. N-doped carbons did not show adequate and consistent sonoactivity for the selective oxidation of 4-Hydroxy-3,5 dimethoxybenzyl alcohol in comparison with control conditions without sonication, which might be associated with an acid-base interaction between the catalysts and the substrate and sonoactivity prohibition by piridinic nitrogen in N-doped catalysts.

Case report: Identification of a novel variant p.Gly215Arg in the CHN1 gene causing Moebius syndrome.

Background: Moebius Syndrome (MBS) is a rare congenital neurological disorder characterized by paralysis of facial nerves, impairment of ocular abduction and other variable abnormalities. MBS has been attributed to both environmental and genetic factors as potential causes. Until now only two genes, PLXND1 and REV3L have been identified to cause MBS. Results: We present a 9-year-old male clinically diagnosed with MBS, presenting facial palsy, altered ocular mobility, microglossia, dental anomalies and congenital torticollis. Radiologically, he lacks both abducens nerves and shows altered symmetry of both facial and vestibulocochlear nerves. Whole-exome sequence identified a de novo missense variant c.643G>A; p.Gly215Arg in CHN1, encoding the α2-chimaerin protein. The p.Gly215Arg variant is located in the C1 domain of CHN1 where other pathogenic gain of function variants have been reported. Bioinformatic analysis and molecular structural modelling predict a deleterious effect of the missense variant on the protein function. Conclusion: Our findings support that pathogenic variants in the CHN1 gene may be responsible for different cranial congenital dysinnervation syndromes, including Moebius and Duane retraction syndromes. We propose to include CHN1 in the genetic diagnoses of MBS.

Role of TBX20 Truncating Variants in Dilated Cardiomyopathy and Left Ventricular Noncompaction.

BACKGROUND: Less than 40% of patients with dilated cardiomyopathy (DCM) have a pathogenic/likely pathogenic genetic variant identified. TBX20 has been linked to congenital heart defects; although an association with left ventricular noncompaction (LVNC) and DCM has been proposed, it is still considered a gene with limited evidence for these phenotypes. This study sought to investigate the association between the TBX20 truncating variant (TBX20tv) and DCM/LVNC. METHODS: TBX20 was sequenced by next-generation sequencing in 7463 unrelated probands with a diagnosis of DCM or LVNC, 22 773 probands of an internal comparison group (hypertrophic cardiomyopathy, channelopathies, or aortic diseases), and 124 098 external controls (individuals from the gnomAD database). Enrichment of TBX20tv in DCM/LVNC was calculated, cosegregation was determined in selected families, and clinical characteristics and outcomes were analyzed in carriers. RESULTS: TBX20tv was enriched in DCM/LVNC (24/7463; 0.32%) compared with internal (1/22 773; 0.004%) and external comparison groups (4/124 098; 0.003%), with odds ratios of 73.23 (95% CI, 9.90-541.45; P<0.0001) and 99.76 (95% CI, 34.60-287.62; P<0.0001), respectively. TBX20tv was cosegregated with DCM/LVNC phenotype in 21 families for a combined logarythm of the odds score of 4.53 (strong linkage). Among 57 individuals with TBX20tv (49.1% men; mean age, 35.9±20.8 years), 41 (71.9%) exhibited DCM/LVNC, of whom 14 (34.1%) had also congenital heart defects. After a median follow-up of 6.9 (95% CI, 25-75:3.6-14.5) years, 9.7% of patients with DCM/LVNC had end-stage heart failure events and 4.8% experienced malignant ventricular arrhythmias. CONCLUSIONS: TBX20tv is associated with DCM/LVNC; congenital heart defect is also present in around one-third of cases. TBX20tv-associated DCM/LVNC is characterized by a nonaggressive phenotype, with a low incidence of major cardiovascular events. TBX20 should be considered a definitive gene for DCM and LVNC and routinely included in genetic testing panels for these phenotypes.

Molecular epidemiology of pneumococcal carriage in children from Seville, following implementation of the PCV13 immunization program in Andalusia, Spain.

INTRODUCTION: The 13-valent pneumococcal conjugate vaccine (PCV13) universal vaccination programme was introduced in December 2016 in Andalusia. METHODS: A cross-sectional study was conducted on the molecular epidemiology of pneumococcal nasopharyngeal colonization. A total of 397 healthy children were recruited from primary healthcare centres in Seville for the periods 1/4/2018 to 28/2/2020 and 1/11/2021 to 28/2/2022 (PCV13 period). Data from a previous carriage study conducted among healthy and sick children from 1/01/2006 to 30/06/2008 (PCV7 period), were used for comparison of serotype/genotype distributions and antibiotic resistance rates. RESULTS: Overall, 76 (19%) children were colonized with S. pneumoniae during the PCV13 period and there were information available from 154 isolates collected during the PCV7 period. Colonization with PCV13 serotypes declined significantly in the PCV13 period compared with historical controls (11% vs 38%, p = 0.0001), being serotypes 19F (8%), 3 (1%) and 6B (1%) the only circulating vaccine types. Serotypes 15B/C and 11A were the most frequently identified non-PCV13 serotypes during the PCV13 period (14% and 11%, respectively); the later one increased significantly between time periods (p = 0.04). Serotype 11A was exclusively associated in the PCV13 period with ampicillin-resistant variants of the Spain9V-ST156 clone (ST6521 and genetically related ST14698), not detected in the preceding period. CONCLUSIONS: There was a residual circulation of vaccine types following PCV13 introduction, apart from serotype 19F. Serotype 11A increased between PCV13 and PCV7 periods due to emergence and clonal expansion of ampicillin-resistant genotype ST6521.

Rasgos funcionales de frutos con importancia particular para los dispersores de semillas en el bosque seco tropical

Introducción: La frugivoría es un proceso ecológico determinante para la estructuración y regeneración de los bosques. En los trópicos, donde la diversidad de plantas y animales frugívoros es alta, las relaciones interespecíficas son complejas y requieren estudio. Objetivo: Identificar las especies de plantas ecológicamente importantes en dos redes de interacción, y el papel de los rasgos funcionales de los frutos en esas interacciones en un bosque seco. Métodos: Recolectamos 10 frutos por planta de 10 plantas de cada especie de interés en un bosque seco colombiano, calculamos el índice de importancia de las plantas a partir de la relevancia de aves y mamíferos frugívoros en la estructura de las redes. Esta relevancia se relaciona directamente con el potencial del animal como dispersor efectivo de semillas. Utilizamos modelos lineales generalizados para estimar el tamaño, color, estrato, y tipo de pulpa, en el índice. Resultados: Las plantas más importantes son especies de los géneros Miconia, Ficus, Cecropia, Bursera, Casearia y Trichilia, también identificadas como recursos importantes para los frugívoros de los trópicos en otros estudios. Las plantas con frutos carnosos, rojos y de menor tamaño son los mejores para dispersores de semillas. El índice de importancia de las plantas tiene alta variación; esto sugiere que un conjunto de especies frugívoras beneficiadas por cada especie de planta tiene una contribución diferenciada en procesos ecológicos derivados de la dispersión de semillas. Conclusiones: Programas de restauración para este tipo de bosque tropical seco debería incluir una variedad de plantas, incluyendo especies con frutos pequeños, rojos y carnosos.

Introduction: Frugivory is a pivotal ecological process for the structure and regeneration of forests. In the tropics, where the diversity of plants and frugivorous animals is high, interspecific relationships in the interaction networks are complex and need study. Objective: To identify ecologically important plant species in two interaction networks, and the role of functional fruit traits in those interactions in a dry forest. Methods: We collected 10 fruits per plant from 10 plants of each species of interest in a Colombian dry forest, we calculated the Plant Importance Index based on the bird and mammal frugivores relevance for network structure. This relevance is directly related to the animal's potential as effective seed dispersers. We used generalized linear models to estimate the effect of fruit size, color, stratum, and type of pulp, on the index. Results: The most important plants are species of the genera Miconia, Ficus, Cecropia, Bursera, Casearia and Trichilia, also identified as important resources for tropical frugivores in other studies. Plants with small, red, and fleshy fruits are the best for seed dispersers. The plant importance index has a high variation; this suggests that the set of frugivore species benefited by each plant species has a differential contribution to the ecological processes derived from seed dispersal. Conclusions: Restoration programs for this kind of tropical dry forest should include a variety of plants, including species with small, red, and fleshy fruits.

Lefort I Osteotomy With and Without Osteogenic Distraction in Cleft Lip and Palate Patients: Experience at Hospital Universitario Infantil De San José.

INTRODUCTION: Cleft lip and cleft palate (CLP) are congenital diseases that lead to several secondary craniofacial anomalies, such as hypoplasia of the middle third of the face, which can be treated with different surgical techniques to help improve functional and esthetic alterations associated with the maxilla. This article reports the results of patients managed with LeFort I osteotomy in the same craniofacial surgery center for 10 years. OBJECTIVE: To determine the postoperative results regarding recurrence rates, malocclusion, and speech status after surgical treatment, in patients with retrusion of the midface with CLP, who underwent LeFort I osteotomy with or without osteogenic distraction (OD). METHODS: A descriptive cohort study was performed at the Hospital Infantil Universitario de San José in Bogotá, Colombia, between 2010 and 2020, evaluating 38 patients with CLP who met the inclusion criteria, all managed by LeFort I osteotomy with and without OD. The authors reported the sociodemographic information, as well as data related to speech before and after surgery, recurrence, complications, and cephalometric characteristics. The recurrence of the patients was described at 6 and 12 months after the surgical procedure. RESULTS: A total of 43 patients met the inclusion criteria, of which 20 patients were managed with conventional LeFort I osteotomy, and 23 with LeFort I osteotomy with OD; 5 patients were excluded due to lack of data in the medical records, with a final sample of 38 patients. The distribution based on sex was: 57.8% men and 42.1% women. Regarding laterality, we have 7 patients with right CLP (18.42%), 11 patients with left CLP (28.9%), and 20 patients with bilateral CLP (52.63%), 100% of patients with a class III bite in Angle's classification. In group 1 (OD), 55% of the patients did not present changes in speech before surgery, 30% presented improvement in speech, and 15% worsened it. In group 2 (conventional advancement), 66% of the patients did not present changes in speech, 5.5% presented improvement, and 27.7% presented worsening of speech based on the preoperative condition, with a clinical recurrence at 6 months of 15% for group 1 and of 33% for group 2, and at 1 year of 20% for group 1 and 16% for group 2. CONCLUSIONS: Osteogenic distraction is a safe method that can be applied in patients with CLP depending on the clinical characteristics. According to what is described in the literature, those patients who require advancement of up to 6 mm treated without OD have obtained good results, showing esthetic improvement by increasing the projection of the middle third of the face, without worsening of velopharyngeal insufficiency and achieving an adequate occlusal class (Angle I) in the immediate postoperative period or after the postoperative orthodontic management. However, in patients who require advances ≥7 mm, it is clear that OD is the best option, given its association with a lower recurrence rate, minimal changes in the speech, achieving occlusion edge-to-edge at the end of the distraction or Angle's class I, which is corroborated by the results obtained in this study.

Cancer Stem Cells and Androgen Receptor Signaling: Partners in Disease Progression.

Cancer stem cells exhibit self-renewal, tumorigenesis, and a high differentiation potential. These cells have been detected in every type of cancer, and different signaling pathways can regulate their maintenance and proliferation. Androgen receptor signaling plays a relevant role in the pathophysiology of prostate cancer, promoting cell growth and differentiation processes. However, in the case of prostate cancer stem cells, the androgen receptor negatively regulates their maintenance and self-renewal. On the other hand, there is evidence that androgen receptor activity positively regulates the generation of cancer stem cells in other types of neoplasia, such as breast cancer or glioblastoma. Thus, the androgen receptor role in cancer stem cells depends on the cellular context. We aimed to analyze androgen receptor signaling in the maintenance and self-renewal of different types of cancer stem cells and its action on the expression of transcription factors and surface markers associated with stemness.

Widespread shifts in body size within populations and assemblages.

Biotic responses to global change include directional shifts in organismal traits. Body size, an integrative trait that determines demographic rates and ecosystem functions, is thought to be shrinking in the Anthropocene. Here, we assessed the prevalence of body size change in six taxon groups across 5025 assemblage time series spanning 1960 to 2020. Using the Price equation to partition this change into within-species body size versus compositional changes, we detected prevailing decreases in body size through time driven primarily by fish, with more variable patterns in other taxa. We found that change in assemblage composition contributes more to body size changes than within-species trends, but both components show substantial variation in magnitude and direction. The biomass of assemblages remains quite stable as decreases in body size trade off with increases in abundance.

Same process, different patterns: pervasive effect of evolutionary time on species richness in freshwater fishes.

Tropical lands harbour the highest number of species, resulting in the ubiquitous latitudinal diversity gradient (LDG). However, exceptions to this pattern have been observed in some taxa, explained by the interaction between the evolutionary histories and environmental factors that constrain species' physiological and ecological requirements. Here, we applied a deconstruction approach to map the detailed species richness patterns of Actinopterygian freshwater fishes at the class and order levels and to disentangle their drivers using geographical ranges and a phylogeny, comprising 77% (12 557) of all described species. We jointly evaluated seven evolutionary and ecological hypotheses posited to explain the LDG: diversification rate, time for speciation, species-area relationship, environmental heterogeneity, energy, temperature seasonality and past temperature stability. We found distinct diversity gradients across orders, including expected, bimodal and inverse LDGs. Despite these differences, the positive effect of evolutionary time explained patterns for all orders, where species-rich regions are inhabited by older species compared to species-poor regions. Overall, the LDG of each order has been shaped by a unique combination of factors, highlighting the importance of performing a joint evaluation of evolutionary, historical and ecological factors at different taxonomic levels to reach a comprehensive understanding on the causes driving global species richness patterns.

Droplet-on-chip electro-spectroscopy detects the ultra-short relaxation time of a dilute polymer solution.

We report an electrode-embedded on-chip platform technology for the precise determination of ultra-short (of the order of a few nanoseconds) relaxation times of dilute polymer solutions, by deploying time-alternating electrical voltages. Our methodology delves into the sensitive dependence of the contact line dynamics of a droplet of the polymer solution atop a hydrophobic interface in response to the actuation voltage, resulting in a non-trivial interplay between the time-evolving electrical, capillary, and viscous forces. This culminates into a time-decaying dynamic response that mimics the features of a damped oscillator having its 'stiffness' mapped with the polymeric content of the droplet. The observed electro-spreading characteristics of the droplet are thus shown to correlate explicitly with the relaxation time of the polymer solution, drawing analogies with a damped electro-mechanical oscillator. By corroborating well with the reported values of the relaxation times as obtained from more elaborate and sophisticated laboratory set-ups. Our findings provide perspectives for a unique and simple approach towards electrically-modulated on-chip-spectroscopy for deriving ultra-short relaxation times of a broad class of viscoelastic fluids that could not be realized thus far.

Electrowetting-Induced Coalescence of Sessile Droplets in Viscous Medium.

Manipulating the coalescence of microdroplets has recently gained enormous attention in digital microfluidics and biological and chemical industries. Here, coalescence between two sessile droplets is induced by spreading them due to electrowetting. The electrocoalescence dynamics is investigated for a wide range of operating parameters such as electrowetting number, Ohnesorge number, driving frequency, and drop to surrounding medium viscosity ratio. Here, the characteristic time scale from the classical lubrication theory is modified with an additional driving and resisting force due to the electrostatic pressure force and liquid-liquid viscous dissipation, respectively. With the revised characteristic time scale, a universal bridge growth is shown between the two merging droplets following a 1/3 power law during early coalescence followed by a long-range linear variation. To ensure precise control on droplet coalescence, a geometric analysis is also performed to define the initial separation distance.

High Performance of a Dominant/X-Linked Gene Panel in Patients with Neurodevelopmental Disorders.

Neurodevelopmental disorders (NDDs) affect 2-5% of the population and approximately 50% of cases are due to genetic factors. Since de novo pathogenic variants account for the majority of cases, a gene panel including 460 dominant and X-linked genes was designed and applied to 398 patients affected by intellectual disability (ID)/global developmental delay (GDD) and/or autism (ASD). Pathogenic variants were identified in 83 different genes showing the high genetic heterogeneity of NDDs. A molecular diagnosis was established in 28.6% of patients after high-depth sequencing and stringent variant filtering. Compared to other available gene panel solutions for NDD molecular diagnosis, our panel has a higher diagnostic yield for both ID/GDD and ASD. As reported previously, a significantly higher diagnostic yield was observed: (i) in patients affected by ID/GDD compared to those affected only by ASD, and (ii) in females despite the higher proportion of males among our patients. No differences in diagnostic rates were found between patients affected by different levels of ID severity. Interestingly, patients harboring pathogenic variants presented different phenotypic features, suggesting that deep phenotypic profiling may help in predicting the presence of a pathogenic variant. Despite the high performance of our panel, whole exome-sequencing (WES) approaches may represent a more robust solution. For this reason, we propose the list of genes included in our customized gene panel and the variant filtering procedure presented here as a first-tier approach for the molecular diagnosis of NDDs in WES studies.

Optimal distribution of the fundamental non-efficient load current terms between the energy gateways connected in grid-tied microgrids.

Main objective of this paper is the optimal distribution of the fundamental non-efficient load current terms between the inverters -Energy Gateways (EGs)- connected in grid-tied microgrids (MGs). The main feature of the presented approach is the use of the EGs as controlled current sources that can compensate fundamental non-efficient load current terms in addition to the generation of fundamental positive-sequence active current, avoiding the use of shunt active power filters. The approach relies on the so-called System of Constant References (SoCR) that is based on the symmetrical components decomposition and dq0 transformation. SoCR procedure decouples efficient and non-efficient components of the instantaneous load currents, transforming all of them into six constant references. The optimization algorithm uses a new approach for the calculation of the peak currents in each phase, avoiding non-convex problems when determining the currents of the EGs considering their operating limits. A medium-power size MG that includes photovoltaic and wind generators, as well as, a battery energy storage system is considered to evaluate the capabilities of the proposal. There were evaluated four scenarios: baseline, balanced distribution, proportional distribution, and optimal distribution. All scenarios, except optimal distribution scenario, surpass the current limits for the EGs connected. The results highlight the benefits of using the EGs as active agents in MG efficient operation and demonstrate how the optimization approach achieves the goal of maintaining the generation capabilities of EGs at the same time that compensates the non-efficient current terms demanded by the load.

Rehabilitation of eroded trails and gullies on quartzite rock outcrops with native species in a high-altitude grassland.

The quartzite rock outcrops and the native vegetation of grasslands located at the Serra da Calçada Mountain in Minas Gerais State (Brazil) have been severely degraded by extreme sports activities such as motocross and off-road vehicles, greatly damaging the abundant headwaters. The main consequences thereof were hilly and gully erosion processes with soil loss and the deviation of the water from its original paths. However, currently, there is no report of successful restoration efforts in severely eroded outcrops in Brazilian high-altitude grasslands (campo rupestre). Through the Universal Soil Loss Equation (USLE), we found a high general erosion rate in the study site (669.91 t·ha-1·year-1), and the specific soil loss provoked by off-road vehicles on trails was significantly greater (49 m3 per 100 m2) than that caused by mountain bikes and trekking (5.8 m3 per 100 m2). We performed the physical reconstruction of eroded outcrops and surface water flow paths by allocating locally available quartzite rocks. These rocks were inoculated with different species of bryophytes and planted with native species under two treatments: un-inoculated and inoculated with arbuscular mycorrhizal fungi (AMF) spores of the Rhizophagus irregularis species. After 2 years, the bryophyte communities showed a similar pattern to the preserved site, and the AMF inoculation favoured plant establishment of most species, especially of the Asteraceae, Cyperaceae, Fabaceae, Malpighiaceae, Orchidaceae and Poaceae families. The AMF also improved the soil fertility, highlighting soil P, SOM, CEC, NH4+-N as well as soil water content and water retention capacity. Poaceae family species showed an outstanding occupation, which was considered a functional indicator of rehabilitation success, functioning as a "hydraulic carpet" for water exportation, conduction and drainage across the outcrops. This study provides an eco-technology to restore severely eroded outcrops over headwaters using native species in the Brazilian high-altitude grasslands.

Scale of population synchrony confirms macroecological estimates of minimum viable range size.

Global ecosystems are facing a deepening biodiversity crisis, necessitating robust approaches to quantifying species extinction risk. The lower limit of the macroecological relationship between species range and body size has long been hypothesized as an estimate of the relationship between the minimum viable range size (MVRS) needed for species persistence and the organismal traits that affect space and resource requirements. Here, we perform the first explicit test of this assumption by confronting the MVRS predicted by the range-body size relationship with an independent estimate based on the scale of synchrony in abundance among spatially separated populations of riverine fish. We provide clear evidence of a positive relationship between the scale of synchrony and species body size, and strong support for the MVRS set by the lower limit of the range-body size macroecological relationship. This MVRS may help prioritize first evaluations for unassessed or data-deficient taxa in global conservation assessments.