New Instrumentation to Accurately Measure the Forward and Backward Scattering Coefficients

The scattering of light is an inherent property of natural bodies of water. As such, they play a crucial role in the study and characterization of natural water. Every optical measurement done in water must take this property into account. The scattering behavior of natural body is a direct consequence of its constituents, including organic and inorganic matter, suspended and dissolved particulates and an air bubbles. In specific, these constituents have characteristic scattering coefficients. A new optical instrument has been developed to independently determine the total scattering and backscattering coefficient of natural bodies of water. The measurement is performed by the collecting a sample of the scattered light over a large angular range, such that it introduces a sin θ weight factor onto the detected volume scattering function of the medium. In other words, the instrument proposed consists of a total scatting coefficient (b) meter and a backscattering coefficient (bb) meter. These meters measured the exact value of b and bb, while not making any assumptions of the scatterers. The measurement principle behind the instrument consists of perfectly calibrated cavity, whose signal output is proportional to the sin of incoming light, scattered light from a light source (532 nm laser). The placement of the meters' aperture is perpendicular to the direction of the laser beam. In other words, at its heart, a highly accurate cosine collector with integrating properties is described. We present the mathematical description, design and development of each meter, along with calibration methods and results of the prototype test. In short, the backscattering coefficient meter consists of placing a 1.5 mm wide, curved aperture in a 19 mm diameter channel. The instrument's laser beam is centered about the channel and the scattered light enters the bb meter through the aperture, yielding and output signal. This signal can be expressed as a direct function of bb. The bb meter is the first instrument of its kind to make a direct measurement of bb. The total scattering coefficient meter consists of placing a 1 cm wide, curved aperture in a 4 mm diameter channel, also centered about a laser beam. The distance of the light source from the center of the meter's aperture defines the angular resolution of the b measurement

Biofertilizantes: alternativa biotecnológica para los agroecosistemas

The increase in the world population has generated a greater demand in food production. Therefore, agriculture has become one of its most representative sectors while providing balance to the economic system, given its contribution to world GDP through the generation of different agricultural products. However, the development of extensive production practices, which are aimed at improving productivity, has promoted the excessive use of chemical supplies, and caused environmental problems such as eutrophication of water sources, soil acidification, decrease in biodiversity or greenhouse gas emissions. Therefore, providing food security without affecting environmental sustainability is our greatest challenge. The development of sustainable agriculture requires reducing the use of agrochemicals and their replacement by more ecological, efficient, and economical products or processes. In this context, the use of biofertilizers has been promoted considering the dynamics and importance of soil microbial communities, as well as their beneficial and cooperative functions in agricultural productivity. This article presents a review of the use of fertilizers, environmental pollution in agroecosystems, biofertilizers and the properties of some microorganisms that serve as the basis for their manufacture (nitrogen fixers and phosphate solubilizers), as well as the general steps of their production process, in such a way that the knowledge of this biotechnology for agroecosystem management is promoted. Today, changes aimed at improving sustainability are taking place with respect to agricultural practices and food production. For this reason, the study of processes such as molecular nitrogen fixation and phosphate solubilization is the basis for improving the quality of biological inputs.El aumento poblacional ha creado una mayor demanda en la producción de alimentos en el ámbito mundial, por lo cual la agricultura es uno de los sectores más representativos, al tiempo que proporciona equilibrio al sistema económico dado su aporte al pib mundial por la generación de diferentes productos agrícolas. Sin embargo, el desarrollo de prácticas productivas extensivas en busca de mejorar la productividad ha promovido la utilización excesiva de insumos químicos y causado problemas ambientales como eutrofización de fuentes hídricas, acidificación del suelo, disminución de biodiversidad o emisión de gases de efecto invernadero. Por ello, el gran desafío es proporcionar seguridad alimentaria sin afectar la sostenibilidad ambiental. El desarrollo de agricultura sostenible requiere reducción del uso de agroquímicos y reemplazo por productos o procesos más ecológicos, eficientes y económicos; contexto en el que se ha promovido el uso de biofertilizantes teniendo en cuenta la dinámica e importancia de las comunidades microbianas del suelo, así como sus funciones benéficas y cooperativas en la productividad agrícola. Este artículo presenta una revisión acerca del uso de fertilizantes, la contaminación ambiental en agroecosistemas, los biofertilizantes y las propiedades de algunos microorganismos que sirven como base para su fabricación (fijadores de nitrógeno y solubilizadores de fosfato), al igual que los pasos generales del proceso de producción, de tal forma que se promueva el conocimiento de esta biotecnología para manejo de agroecosistemas. Hoy se están produciendo cambios respecto a las prácticas agrícolas y la producción de alimentos en busca de la sostenibilidad; por tal motivo, el estudio de procesos como fijación de nitrógeno molecular y solubilización de fosfatos constituye una base para mejorar la calidad de los insumos biológicos

Estudio preliminar de variables químicas en suelos con procesos de revegetalización en el municipio de Villa de Leyva (Boyacá, Colombia)

The present study was carried out withthe objective of analyzing the organic mattercontent (OM), pH, cation exchange capacity (CEC)and electrical conductivity (EC), in soils located inthe village Ritoque Alto of the municipality of Villade Leyva (Boyacá-Colombia) where processes ofrevegetation have been advanced. Some chemicalcharacteristics of the soil were studied to be ableto evaluate in the future if the revegetalizationprocess has had any effect on them, andwhether it can be considered as an alternative ofmanagement and restoration of degraded areas.For this, six samples were carried out in a sitewhere previous processes of revegetation withfour native plant, for restoration purposes (and theproposed variables were quantified. There weresignificant statistical differences (p‰¤0.05) in theOM and EC parameters. The results indicate thatthe evaluated soil has a very high OM content,very strongly acidic pH, CEC within normal limits,and a low EC, which suggests the need to applysome type of amendment in such a way that thesoil can recover certain chemical properties, andwith this to positively affect the process of recoveryadvanced in the area.El proyecto de investigación que origina este artículo tiene como objetivo analizar el contenido de materia orgánica (MO), pH, capacidad de intercambio catiónico (CIC) y conductividad eléctrica (CE) en suelos ubicados en la vereda Ritoque Alto del municipio de Villa de Leyva (Boyacá-Colombia), en donde se adelantan procesos de revegetalización. De igual manera, se estudian algunas características químicas del suelo para evaluar a futuro el efecto del procesode revegetalización y poder considerar una alternativa de manejo y restauración de áreas degradadas. Para ello se realizan seis muestreos en un predio donde se adelantan procesos previos de revegetalización con cuatro especies vegetales nativas con fines de restauración (y se cuantifican las variables propuestas. Además, se presentan diferencias estadísticas significativas (p‰¤0,05) en los parámetros MO y CE. Los resultados indican que el suelo evaluado presenta un contenido muy alto de MO, pH muy fuertemente ácido, CIC dentro de los límites normales y una baja CE, lo que sugiere la necesidad de aplicar algún tipo de enmienda de tal forma que el suelo pueda recuperar ciertas propiedades químicas e incidir positivamente sobre el proceso de recuperación adelantado en la zona

Microorganismos funcionales en suelos con y sin revegetalización en el municipio de Villa de Leyva, Boyacá

Ecological restoration initiatives that include revegetation techniques are complex processes that can be affected by many biotic and abiotic variables. Among the latter, populations of microorganisms play a fundamental role in the release of nutrients and therefore in the establishment of plant species in the areas to be restored. The study sought to evaluate the density of microbial communities related to the nutrient cycles of carbon, phosphorus and nitrogen known as functional groups present in a revegetated soil and another zone without intervention in the municipality of Villa de Leyva. Methods used in this evaluation were standard plate counts using selective culture media,  also a correlation analysis were also performed between groups to evidence possible ecological interactions. In general populations of all functional groups of microorganisms are present in the two zones evaluated. Only significant differences were found for counts of phosphate solubilizing bacteria and proteolytic microorganism populations (p≤0.05). Some statistically significant correlations were found between some microbial groups that could indicate processes of cometabolism and competition among microbial populations of the soil, which favors the ecological balance of the same.Las iniciativas en restauración ecológica que incluyen técnicas de revegetalización son procesos complejos que pueden ser afectados por muchas variables bióticas y abióticas. Dentro de estas últimas, las poblaciones de microorganismos juegan un rol fundamental en la liberación de nutrientes y, por tanto, en el establecimiento de especies vegetales en las áreas a restaurar. El estudio buscó evaluar la densidad de las comunidades microbianas relacionadas con los ciclos de nutrientes del carbono, fósforo y nitrógeno conocidas como grupos funcionales presentes en un suelo revegetalizado y otro sin revegetalizar en el municipio de Vila de Leyva. Los métodos empleados en esta evaluación fueron: recuento en placa estándar utilizando medios de cultivo selectivos y análisis de correlación entre grupos para evidenciar posibles interacciones de tipo ecológico. En general, las poblaciones de todos los grupos funcionales de microorganismos están presentes en las dos zonas evaluadas. Solo se encontraron diferencias significativas para los recuentos de las bacterias solubilizadoras de fosfato y las poblaciones de microorganismos proteolíticos (p≤0,05). Se encontraron algunas correlaciones estadísticamente significativas entre unos grupos microbianos que podrían indicar procesos de cometabolismo y competencia entre poblaciones microbianas del suelo, los cuales favorecen el equilibrio ecológico del mismo

Surgical Management of Indeterminate Thyroid Nodules across Different World Regions: Results from a Retrospective Multicentric (the MAIN-NODE) Study

Indeterminate thyroid nodules (ITNs) are characterized by an expected malignancy ranging from 5% to 30%, with most patients undergoing a diagnostic, rather than therapeutic, operation. The aim of our study was to compare the approach to ITNs across different regions of the world. In this retrospective, multicentric, international study, according to the WHO classification, we identified the South East Asian Region (SEAR), the Americas Region (AMR), the Eastern Mediterranean Region (EMR), the Europe Region (EUR), and the Western Pacific Region (WPR). One high-volume thyroid centre was included for each region. Demographic, preoperative, and pathologic data were compared among the different regions. Overall, 5737 patients from five high-volume thyroid centres were included in this study. We found that the proportion of ITNs over the global activity for thyroid disease was higher in the EUR (37.6%) than in the other regions (21.1-23.6%). In the EMR, the patients were significantly younger (with a mean of 43.1 years) than in the other regions (range, 48.8-57.4 years). The proportion of lobectomy was significantly higher in the WPR, where 83.2% (114/137) of patients received this treatment, than in the other regions, where lobectomies were performed in 44.1-58.1% of patients. The pathological diagnosis of malignancy was significantly higher in the SEAR centre, being over 60%, than in centres of the other regions, where it ranged from 26.3% to 41.3%. The occurrence of lymph node metastases was higher in the WPR (27.8%), AMR (26.9%), and EMR (20%) centres than in the EUR and SEAR centres, where it was lower than 10%. In summary, we found in our study different approaches and outcomes in the diagnosis and treatment of ITNs among countries. Overall, almost 60% of patients with ITNs who underwent surgery actually presented a benign disease, potentially undergoing an unnecessary operation

Ultrasensitive detection of waste products in water using fluorescence emission cavity-enhanced spectroscopy

Clean water is paramount to human health. In this article, we present a technique for detection of trace amounts of human or animal waste products in water using fluorescence emission cavity-enhanced spectroscopy. The detection of femtomolar concentrations of urobilin, a metabolic byproduct of heme metabolism that is excreted in both human and animal waste in water, was achieved through the use of an integrating cavity. This technique could allow for real-time assessment of water quality without the need for expensive laboratory equipment

The Risk of Malignant Degeneration of Müllerian Derivatives in PMDS: A Review of the Literature

Persistent Müllerian Duct Syndrome (PMDS) is a rare autosomal recessive disorder of sex development characterized by the presence of fallopian tubes, uterus and upper one-third of the vagina in individuals with XY genotype and normal male phenotype. The main complications of PMDS are infertility and the rare risk of malignant degeneration of both testicular and Müllerian derivatives. We report the case of a 49-year-old man who, during repair of an incisional hernia, was incidentally found to have a uterine-like structure posterior to the bladder. In the past at the age of 18 months, he had undergone bilateral orchidopexies for bilateral cryptorchidism. The intraoperative decision was to preserve the uterine-like structure and make a more accurate diagnosis postoperatively. Evaluation revealed an XY chromosome and imaging consistent with PMDS. The patient was informed about the risk of neoplastic transformation of the residual Müller ducts and was offered surgical treatment, which he declined. Subsequent follow-up imaging studies, including testicular and pelvic ultrasound, were negative for findings suggestive of malignant testicular and Mullerian derivative degeneration. A review of the international literature showed that, when a decision is taken to remove the Mullerian derivatives, laparoscopy and especially robotic surgery allow for the successful removal of Müllerian derivatives. Whenever the removal of these structures is not possible or the patient refuses to undergo surgery, it is necessary to inform the patient of the need for adequate follow-up. Patients should undergo regular pelvic imaging examination and MRI might be a better method for that purpose

Evolving trends in the management of acute appendicitis during COVID-19 waves. The ACIE appy II study

Background: In 2020, ACIE Appy study showed that COVID-19 pandemic heavily affected the management of patients with acute appendicitis (AA) worldwide, with an increased rate of non-operative management (NOM) strategies and a trend toward open surgery due to concern of virus transmission by laparoscopy and controversial recommendations on this issue. The aim of this study was to survey again the same group of surgeons to assess if any difference in management attitudes of AA had occurred in the later stages of the outbreak. Methods: From August 15 to September 30, 2021, an online questionnaire was sent to all 709 participants of the ACIE Appy study. The questionnaire included questions on personal protective equipment (PPE), local policies and screening for SARS-CoV-2 infection, NOM, surgical approach and disease presentations in 2021. The results were compared with the results from the previous study. Results: A total of 476 answers were collected (response rate 67.1%). Screening policies were significatively improved with most patients screened regardless of symptoms (89.5% vs. 37.4%) with PCR and antigenic test as the preferred test (74.1% vs. 26.3%). More patients tested positive before surgery and commercial systems were the preferred ones to filter smoke plumes during laparoscopy. Laparoscopic appendicectomy was the first option in the treatment of AA, with a declined use of NOM. Conclusion: Management of AA has improved in the last waves of pandemic. Increased evidence regarding SARS-COV-2 infection along with a timely healthcare systems response has been translated into tailored attitudes and a better care for patients with AA worldwide

Functional microorganisms in soil with and without revegetation in the municipality of Villa de Leyva-Boyaca

Las iniciativas en restauración ecológica que incluyen técnicas de revegetalización son procesos complejos que pueden ser afectados por muchas variables bióticas y abióticas. Dentro de estas últimas, las poblaciones de microorganismos juegan un rol fundamental en la liberación de nutrientes y, por tanto, en el establecimiento de especies vegetales en las áreas a restaurar. El estudio buscó evaluar la densidad de las comunidades microbianas relacionadas con los ciclos de nutrientes del carbono, fósforo y nitrógeno conocidas como grupos funcionales presentes en un suelo revegetalizado y otro sin revegetalizar en el municipio de Vila de Leyva. Los métodos empleados en esta evaluación fueron: recuento en placa estándar utilizando medios de cultivo selectivos y análisis de correlación entre grupos para evidenciar posibles interacciones de tipo ecológico. En general, las poblaciones de todos los grupos funcionales de microorganismos están presentes en las dos zonas evaluadas. Solo se encontraron diferencias significativas para los recuentos de las bacterias solubilizadoras de fosfato y las poblaciones de microorganismos proteolíticos (p≤0,05). Se encontraron algunas correlaciones estadísticamente significativas entre unos grupos microbianos que podrían indicar procesos de cometabolismo y competencia entre poblaciones microbianas del suelo, los cuales favorecen el equilibrio ecológico del mismo.Ecological restoration initiatives that include revegetation techniques are complex processes that can be affected by many biotic and abiotic variables. Among the latter, populations of microorganisms play a fundamental role in the release of nutrients and therefore in the establishment of plant species in the areas to be restored. The study sought to evaluate the density of microbial communities related to the nutrient cycles of carbon, phosphorus and nitrogen known as functional groups present in a revegetated soil and another zone without intervention in the municipality of Villa de Leyva. Methods used in this evaluation were standard plate counts using selective culture media,  also a correlation analysis were also performed between groups to evidence possible ecological interactions. In general populations of all functional groups of microorganisms are present in the two zones evaluated. Only significant differences were found for counts of phosphate solubilizing bacteria and proteolytic microorganism populations (p≤0.05). Some statistically significant correlations were found between some microbial groups that could indicate processes of cometabolism and competition among microbial populations of the soil, which favors the ecological balance of the same