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For the first time, the International Symposium on Fungal Stress was joined by the XIII International Fungal Biology Conference. The International Symposium on Fungal Stress (ISFUS), always held in Brazil, is now in its fourth edition, as an event of recognized quality in the international community of mycological research. The event held in São José dos Campos, SP, Brazil, in September 2022, featured 33 renowned speakers from 12 countries, including: Austria, Brazil, France, Germany, Ghana, Hungary, México, Pakistan, Spain, Slovenia, USA, and UK. In addition to the scientific contribution of the event in bringing together national and international researchers and their work in a strategic area, it helps maintain and strengthen international cooperation for scientific development in Brazil.

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The present study examines the notion that polarized exocytosis in the tips of growing hyphae creates an excess of plasma membrane and thus the need for its removal by endocytosis. To measure endocytosis experimentally, we developed a photobleaching (FRAP) procedure to count endocytic events in hyphae of Neurospora crassa carrying a fluorescent tag on the actin-binding protein fimbrin (FIM-1-GFP). Given 40 nm as the average diameter of endocytic vesicles, we calculated that about 12.5% of the plasma membrane discharged in the apex becomes endocytosed in the subapex. According to our calculations, the GFP-tagged hyphae of N. crassa, measured under the constrained conditions of confocal microscopic examination, needed about 8800 vesicles/min to extend their plasma membrane or about 9800/min, if we include predicted demands for cell wall growth and extracellular secretion. Our findings support the notion that exocytosis and endocytosis operate in tandem with the latter serving as a compensatory process to remove any excess of plasma membrane generated by the intense exocytosis in the hyphal tips. Presumably, this tandem arrangement evolved to support the hallmark features of fungi namely rapid cell extension and abundant secretion of hydrolytic enzymes.

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Hyphae of the Ascomycota are tubular cells compartmentalized by perforated septa, whose central pore allows the flow of organelles and cytoplasm. While in plants and yeast septation leads to cell separation, in filamentous fungi the formation of crosswalls appears to have an architectural role, limits the extent of mechanical damage thus maintaining hyphal integrity, and also is of fundamental importance as part of cell differentiation. The increasing number of available fungal genome sequences, knockout mutants, versatile tools for protein tagging, and the continuous improvement of fluorescence microscopes have allowed scientists to analyze living cells and reveal the molecular and cellular basis of septation with unprecedented detail. This review summarizes the recent advances in septum ontogenesis in Neurospora crassa. A "septal actomyosin tangle" is the first indication of impending septation. It assembles prior to any visible evidence of plasma membrane inward growth, which occurs concomitantly with the formation and constriction of a contractile actomyosin ring and synthesis of the septum wall. One of the key questions in septum biogenesis is how the septation machinery is assembled to construct a centripetally growing crosswall. Most of the machinery utilized in apical cell wall growth can be expected at septation sites to ensure an organized arrival and supply of vesicles leading to the formation of a septum. Yet, the intrinsically different architecture of the septum may require a different organization and regulation of the wall-synthesizing machinery.

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Objetivo. Se propone el cálculo de los años acumulados de vida productiva potencial perdidos (AAVPPP) para complementar la evaluación de las pérdidas por accidentes de trabajo. Material y métodos. A partir de los datos obtenidos del Departamento General de Medicina del Trabajo de la Gerencia Médica de Petróleos Mexicanos, se analizaron 8 638 accidentes de trabajo dictaminados entre el 1 de enero de 1990 y el 30 de junio de 1993. Las variables independientes consideradas fueron: sexo, edad, sitio y tipo de lesión, nivel de ingresos, y situación laboral; la variable dependiente fue el porcentaje de incapacidad permanente. A partir del indicador propuesto se calcularon los AAVPPP. Resultados. El 19.5 por ciento de los accidentados quedó con algún grado de secuela; el total de AAVPPP fue de 5 611, con un promedio por caso de 3.2 años; de las variables analizadas el sexo masculino, los niveles de ingreso más bajos, la situación contractual transitoria y las lesiones en mano y muñeca fueron las que más AAVPPP aportaron. Se observaron diferencias al comparar la jerarquización de algunas variables independientes en función de diversos criterios con el de AAVPPP. Conclusiones. Este indicador es aplicable en el área operativa de seguridad e higiene; complementa la información de indicadores similares y se considera útil para la planeación de programas y la evaluación de riesgos de trabajo

There are different indicators to give priority to health problems within the area of occupational health; we propose the calculation of accummulated years of potential productive life lost (AYPPLL) to estimate the loss of material and human resources due to work accidents. Material and methods. A total of 8 638 work accidents were analized using this method. Independent variables were: sex, age, place and type of accident, subject's income and work conditions. The dependent variable was permanent disability. Results. Subjects who had some kind of permanent damage were 19.5%; the total number of AYPPLL was 5 611, with an average of 3.2 YPPLL per accident. Variables associated with the highest AYPPLL were the socio-demographic variables, male sex, lowest income levels, temporary work contracts and injuries of the hand and wrist. Conclusions. The AYPPLL method was found to be a valuable indicator of the safety and hygiene of the worksite and a useful tool for planning and evaluating work accident programs.

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