170 research outputs found

    Effects of radio-frequency fields on bacterial cell membranes and nematode temperature-sensitive mutants

    Get PDF
    Membrane-related bioeffects have been reported in response to both radio-frequency (RF) and extremely low-frequency (ELF) electromagnetic fields (EMFs), particularly in neural cells. We have tested whether RF fields might cause inner membrane leakage in ML35 E. coli cells, which express β-galactosidase (lacZ) constitutively, but lack the lacY permease required for substrate entry. The activity of lacZ (indicating substrate leakage through the inner cell membrane) was increased only slightly by RF exposure (1 GHz, 0.5 W) over 45 min. Since lacZ activity showed no further increase with a longer exposure time of 90 min, this suggests that membrane permeability per se is not significantly affected by RF fields, and that slight heating (≤ 0.1°C) could account for this small difference. Temperature-sensitive (ts) mutants of the nematode, Caenorhabditis elegans, are wild-type at 15°C but develop the mutant phenotype at 25°C; an intermediate temperature of 21°C results in a reproducible mixture of both phenotypes. For two ts mutants affecting transmembrane receptors (TRA-2 and GLP-1), RF exposure for 24 h during the thermocritical phase strongly shifts the phenotype mix at 21°C towards the mutant end of the spectrum. For ts mutants affecting nuclear proteins, such phenotype shifts appear smaller (PHA-1) or non-significant (LIN-39), apparently confirming suggestions that RF power is dissipated mainly in the plasma membrane of cells. However, these phenotype shifts are no longer seen when microwave treatment is applied at 21°C in a modified exposure apparatus that minimises the temperature difference between sham and exposed conditions. Like other biological effects attributed to microwaves in the C. elegans system, phenotype shifts in ts mutants appear to be an artefact caused by very slight heating

    El Hombre en La Obra de Federico Garcia Lorca

    Get PDF

    Activities of Daily Living and Categorization Skills of Elderly with Cognitive Deficit: A Preliminary Study

    Get PDF
    Cognitive dysfunction affects the performance of Activities of Daily Living (ADL) and the quality of life of people with these deficits and their caregivers. To the knowledge of the authors, to date, there are few studies that focus on knowing the relationship between personal autonomy and deductive reasoning and/or categorization skills, which are necessary for the performance of the ADL. The aim of this study was to explore the relationships between ADL and categorization skills in older people. The study included 51 participants: 31 patients with cognitive impairment and 20 without cognitive impairment. Two tests were administered to assess cognitive functions: (1) the Montreal Cognitive Assessment (MoCA); and (2) the digital version of Riska Object Classification test (ROC-d). In addition, the Routine Tasks Inventory-2 (RTI-2) was applied to determine the level of independence in activities of daily living. People with cognitive impairment performed poorly in categorization tasks with unstructured information (p = 0.006). Also, the results found a high correlation between cognitive functioning and the performance of ADLs (Physical ADL: r = 0.798; p < 0.001; Instrumental ADL: r = 0.740; p < 0.001), a moderate correlation between Physical ADLs and categorization skills (unstructured ROC-d: r = 0.547; p < 0.001; structured ROC-d: r = 0.586; p < 0.001) and Instrumental ADLs and categorization skills in older people (unstructured ROC-d: r = 0.510; p < 0.001; structured ROC-d: r = 0.463; p < 0.001). The ROC-d allows the assessment of categorization skills to be quick and easy, facilitating the assessment process by OT, as well as the accuracy of the data obtained.Ministerio de Ciencia, Innovación y Universidades (Spain) RTI2018-099942-B-100Junta de Comunidades de Castilla-La Mancha SBPLY/17/180501/00049

    Relación de flexo-extensores de rodilla en la prevención de lesiones de muslo

    Get PDF
    Prevenir lesiones implica una correcta identificación y entendimiento de los factores que originaron dicha lesión
    • …
    corecore