In theoretical and experimental approaches to the study of sperm competition, it is often assumed that ejaculates always contain enough sperm of good quality and that they are successfully transferred and used for fertilization. However, this view neglects the potential effects of infertility and sperm limitation. Permanent or temporal male infertility due to male sterility, insemination failures, or failures to fertilize the ova implies that some males do not achieve sperm representation in the female reproductive tract after mating. A review of the literature suggests that rates of nonsperm representation may be high; values for the proportion of infertile matings across 30 insect species vary between 0% and 63%, with the median being 22%. I simulated P2 (the proportion of offspring fathered by the second male to copulate with a female in a double-mating trial) distributions under a mechanism of random sperm mixing when sample sizes and rates of male infertility varied. The results show that nonsperm representation can be responsible for high intraspecific variance in sperm precedence patterns and that it can generate misleading interpretations about the mechanism of sperm competition. Nonsperm representation might be a common obstacle in the studies of sperm competition and postcopulatory female choice.

Castor bean pollen is an allergen which causes respiratory (mainly nasal) symptoms.

The Southern Wide-field Gamma-ray Observatory (SWGO) project aims to build an array of air-shower detectors in the Southern hemisphere. Intensive site search activities are ongoing. We developed an Autonomous Environmental and Scientific SWGO Site Characterization Instrument (AEROSITE) to measure environmental characteristics of the proposed sites and deployed four of them in Argentina, Bolivia, Chile and Peru. The instruments are located at very high altitudes of more than 4500 m.a.s.l. We completed an intensive cross-calibration campaign to validate the performance and sensitivity of all AEROSITEs in 2020 and installed the instruments at the sites between October 2021 and April 2022. The instruments are gathering important data without any major issues. At some candidate sites, non-SWGO environmental monitoring systems are also available. In this case, the AEROSITE serves as a cross-calibration instrument to allow a possible extension of the data points to the past using the available data sources. On the other hand, the AEROSITE data are important for designing the SWGO detectors using the real conditions at the sites such as temperatures, wind, electric field and seismic activity.

Presentación de casos clínicos RESUMENLa dermatitis o eccema numular es una patología poco frecuente en pediatría. El cuadro se caracteriza por un inicio con diminutas pápulas y vesículas eritematovioláceas que confluyen en placas exudativas de forma circular y evolucionan a placas eccematosas o liquenificadas de forma discoide o anular. Aparecen, predominantemente, en superficies extensoras de las extremidades, aunque pueden encontrarse en el tronco, las manos o los pies. El diagnóstico es clínico; solo en casos con mala evolución pueden ser necesarias pruebas complementarias. La base del tratamiento son los corticoides tópicos y, si se encuentra un desencadenante infeccioso, el tratamiento de la causa. Su evolución suele ser crónica o recidivante. Se presentan dos casos clínicos en población pediátrica con la finalidad de difundir entre los pediatras su conocimiento y manejo. Palabras clave: dermatitis numular, eccema numular. ABSTRACTNummular eczema or dermatitis is an uncommon paediatric pathology. It is presented as red-purplish small papules and vesicles that join to form exudative circular patches and then to eczematous or lichenified patches with discoid shape. The lesions appear predominantly on the extensor surface of extremities, although they can appear in trunk, hands or feet. This pathology has a clinical diagnosis; only few cases require complementary test. The topical corticosteroids are the mainstay of the treatment, and the causal treatment whether an infectious trigger is found. The patients have chronic or recurrent evolution. We report two cases in children with the aim of spreading knowledge among pediatricians. "moneda" en latín, y se refiere a la forma que adoptan las lesiones. A continuación, se detallan dos casos clínicos. CASOS CLÍNICOS Caso 1Niña de 4 años sana, correctamente vacunada, con dermatitis atópica como único antecedente de interés, sin infecciones respiratorias ni gastrointestinales los días previos, que consultó por placas circulares de aspecto eritematocostroso c o n d i s p o s i c i ó n b i l a t e r a l y s i m é t r i c a e intensamente pruriginosas situadas, sobre todo, en las extremidades y, en menor cuantía, en el tronco (Figura 1). Presentaba eritema por dermatitis atópica en la región púbica.Se inició un tratamiento con amoxicilinaclavulánico oral (50 mg/kg/día en tres dosis) y mupirocina tópica (3 aplicaciones/día) por sospecha de sobreinfección bacteriana, así como medidas higiénicas (fundamentalmente, evitar el contacto con irritantes) e hidroxicina oral (1,5 mg/ kg/día en tres dosis) para el prurito. No se obtuvo mejoría a la semana de evolución, por lo que se cambió a prednicarbato tópico (1 aplicación/ día). Persistió la mala evolución al cabo de una semana del inicio de su aplicación y se derivó a consulta con Dermatología Infantil, que confirmó el diagnóstico y se inició el tratamiento con prednisona oral (1 mg/kg/día en 1 dosis), a pesar de no ser un tratamiento habitual y debido a la intensa interferencia del prurito de este caso con el sueño y con la v...

No abstract