No abstract

A test under laboratory conditions was performed to typify and model the vertical movement of a nematicide (DiTera) applied at concentrations of 400, 700, and 1000 mg L -1 via drip irrigation to a sandy loam class soil confined in tanks of 1 m 3. Vacuum extractometers were set up in the tank at different depths to obtain samples of soil solution starting 10 cm away from the drip emitter. HPLC was used to measure the nematicide concentration in the soil solution. Later HYDRUS 1D was used to model the vertical nematicide concentration considering homogeneous soil. Soil hydraulic parameters were obtained from laboratory experiments whereas the dispersion length was obtained by inverse estimation matching measured and modeled data. Laboratory results showed no significant differences in vertical nematicide (distribution considered a fraction of the initial concentration), having a higher concentration at the surface and decreasing gradually with the depth. The predictive model was able to describe te nematicide behavior of the nematicide according to controlled test, obtaining a R 2 of 0.97, a RMSE of 67.41 mg L -1 , a RRMSE of 13.33% and a Nash of 0.92. These results confirm the proposed model;however, further studies on this issue are needed, considering different scenarios in laboratory conditions and thus scaling it up to field conditions.

Opuntia ficus-indica is a versatile crop that is resilient to drought, making it perfect for semiarid to arid zones. However, the lack of knowledge associated with its benefits and the lack of simple crop growth simulation models to determine its potential development, among others, has prevented its expansion. Transpiration-use efficiency (w) has been used to evaluate crop performance under different water supplies; however, the lack of consistency in w values under different environmental conditions has impeded its use as a transferable parameter. To overcome this problem, w is estimated through the normalized water-use efficiency (kDa) and the vapor pressure deficit (Da) as w = kDa Da-1, where kDa is a crop-dependent parameter. Therefore, the goals of this research were (i) to determine w and kDa in young plants of Opuntia ficus-indica and (ii) to compare the obtained parameters with values from other species. The w and kDa results were 18.57 (g kg-1) and 6.48 (g kPa kg-1), respectively. Here, w was more than two to six times the value for traditional cereals (maize, rice, wheat), while kDa was larger than that of most C3 crops and fell in the range for C4 and CAM crops. This is the first study that explicitly determines kDa for Opuntia ficus-indica; hence, more research should be carried out on its estimation, including under different agroclimatic conditions and in later stages of development. As a first approximation, the parameters obtained here can be used as a simple model to estimate yield projections of Opuntia ficus-indica.

Nowadays, people can access a wide range of applications and services for mobile device users. Among them, location-based services (LBS), where the application needs the user’s position to provide the service. Some examples of these applications are Uber and Waze. Nevertheless, the repetitive use of an LBS can reveal confidential user information; thus, behavior patterns—such as daily routes—could be deduced by some dishonest LBS. Furthermore, a query’s keywords could provide information about a user’s health status or future position when it inquires about hospitals or hotels. Therefore, an adversary can use this information for unethical purposes, and users need mechanisms that protect their privacy. At present, several approaches separately tackle location privacy, location security, and query privacy. To the best of our knowledge, no previous work deals with all these mentioned aspects simultaneously especially when users demand continuous protection when moving and accessing an LBS. This paper proposes two batch techniques to provide location privacy, location safety, and query privacy in an environment that considers a continuous LBS. These techniques apply l -diversity (query privacy) in a context that contemplates query semantics, as well as a diverse set of users’ paths. Extensive experimentation shows that both techniques are cost-effective and scalable solutions that offer unified location privacy, query privacy, and location safety protection for many mobile users.

Con la reintegración del protagonismo de las mujeres en procesos fisiológicos resurgió la idea del parto en domicilio. Objetivo. Describir los resultados obstétricos y perinatales del parto planificado en domicilio asistido por matronas de la Asociación Maternas Chile A.G., entre los años 2015-2021 en Chile. Material y Método. Estudio cuantitativo, observacional, transversal. Resultados. La población estudiada fue de 847 mujeres; 742 tuvieron un parto en casa atendido por profesional matrona. Un 49,12% de las mujeres terminó con un periné indemne y un 8,54% tuvo complicaciones posparto, de ellas, un 2,13% debieron ser trasladadas a un centro asistencial. Los motivos de traslado más frecuentes no tuvieron relación estadística significativa con la edad materna ni paridad. Un 6,2% de los recién nacidos tuvieron un diagnóstico adicional. Conclusiones. Los resultados de este estudio concuerdan con estudios internacionales que indican baja incidencia en morbi-mortalidad de los partos domiciliarios. Sin embargo, se hace imprescindible la instauración de políticas públicas y protocolos que establezcan directrices para esta atención y la necesidad de coordinación directa con la red asistencial, con el fin de favorecer los resultados maternos-fetales.