1,068 research outputs found
Remote sensing of cloud base charge
Layer clouds are abundant in the Earth's atmosphere. Such clouds do not
become sufficiently strongly charged to generate lightning, but they show weak
charging along the upper and lower cloud boundaries where there is a
conductivity transition. Cloud edge charging has recently been observed using
balloon-carried electrometers. Measurement of cloud boundary charging without
balloons is shown to be possible here for low altitude (<1km) charged cloud
bases, through combining their effect on the surface electric field with laser
time of flight cloud base height measurements, and the application of simple
electrostatic models.Comment: Proceedings of the Electrostatics Society of America conference,
Ottawa, June 201
An Investigation of Prekindergarten Teachersâ Read Aloud Choices
The value of childrenâs literature as a tool for promoting literacy, improving content knowledge, and increasing print motivation is evident. Empirical evidence relating to the types of books early childhood teachers read aloud and the reasons for their choices, however, does not exist. The purpose of this descriptive study was to provide current, in-depth documentation of the read-aloud book choices of prekindergarten teachers (n=151) in a nationally recognized, state-wide program regarding the variables of genre, publication date, and diversity along with the teachersâ rationale for selecting the books. Responses to two open-ended questions inspired by Yopp and Yopp (2006) were analyzed thematically and compared with research-based recommendations for best practices. Books read aloud were quite homogenous, including mostly recently published examples of contemporary realistic fiction or folklore with almost no multicultural or award-winning books present. The findings highlight the importance of increasing early childhood teachersâ knowledge of childrenâs literature and the implications of book choice on childrenâs development and learning
Miniaturized atmospheric ionization detector
A small scintillator-based detector for atmospheric ionization measurements
has been developed, partly in response to a need for better ionization data in
the weather-forming regions of the atmosphere and partly with the intention of
producing a commercially available device. The device can measure both the
count rate and energy of atmospheric ionizing radiation. Here we report results
of a test flight over the UK in December 2017 where the detector was flown with
two Geiger counters on a meteorological radiosonde. The count rate profile with
height was consistent both with the Geigers and with previous work. The energy
of incoming ionizing radiation increased substantially with altitude.Comment: Proc 18th Conference on Atmospheric Electricity, Nara, Japan, June
201
Lord Kelvinâs atmospheric electricity measurements
Lord Kelvin (William Thomson) made important contributions to the study of atmospheric elec-
tricity during a brief but productive period from 1859â1861. By 1859 Kelvin had recognised the need for
âincessant recordingâ of atmospheric electrical parameters, and responded by inventing both the water dropper
equaliser for measuring the atmospheric potential gradient (PG), and photographic data logging. The water
dropper equaliser was widely adopted internationally and is still in use today. Following theoretical consid-
erations of electric field distortion by local topography, Kelvin developed a portable electrometer, using it to
investigate the PG on the Scottish island of Arran. During these environmental measurements, Kelvin may
have unwittingly detected atmospheric PG changes during solar activity in August
/
September 1859 associated
with the âCarrington eventâ, which is interesting in the context of his later statements that solar magnetic influ-
ence on the Earth was impossible. Kelvinâs atmospheric electricity work presents an early representative study
in quantitative environmental physics, through the application of mathematical principles to an environmental
problem, the design and construction of bespoke instrumentation for real world measurements and recognising
the limitations of the original theoretical view revealed by experimental wor
Learning strategies and its relation with school performance in the formation of Civil Engineers: FES AragĂłn, UNAM Case
El propĂłsito de este trabajo consiste en determinar si las Estrategias de Aprendizaje (EA)
influyen en el Rendimiento AcadĂŠmico (RA) de los alumnos de noveno semestre de la
carrera de IngenierĂa Civil de la Facultad de Estudios Superiores (FES) AragĂłn de la
Universidad Nacional AutĂłnoma de MĂŠxico (UNAM); en este caso, hablamos de una
poblaciĂłn de 34 estudiantes a quienes se le aplicĂł el Cuestionario de EvaluaciĂłn de las
Estrategias de Aprendizaje de los Estudiantes Universitarios (CEVEAPEU) que fue
elaborado por Bernardo Gallardo, JesĂşs M. SuĂĄrez-RodrĂguez y Cruz PĂŠrez PĂŠrez en el
aĂąo 2009, con el objetivo de presentar un instrumento mĂĄs completo para evaluar el uso de
Estrategias de Aprendizajes por parte de los estudiantes universitarios. EstĂĄ conformado
por dos escalas, seis sub-escalas, veinticinco estrategias y ochenta y ocho Ătems con
respuesta: muy en desacuerdo, en desacuerdo, indeciso, de acuerdo, muy de acuerdo.
Asimismo, para dicha poblaciĂłn, se indagĂł cuĂĄl fue su Rendimiento AcadĂŠmico, reflejado
en su promedio general de calificaciones obtenido hasta el octavo semestre cursado de la
licenciatura; el rango de estos fue de 6.91 a 9.14The purpose of this paper is to determine if the Learning Strategies (EA) influence
academic performance (RA) of de students of the ninth semester of engineering, the study
superior faculty (FES) Aragon, about of Mexico National University (UNAM). In the case
speak about of o the 34 population of stdents to whom it was applied test Evaluation
Questionnaire of Learning Strategies for University Students (CEVEAPEU), to write for
Bernardo Gallardo, Jesus M. Suarez-Rodriguez and Cruz Perez Perez in the year of 2009,
With the aim of presenting a more complete instrument to evaluate the use of Learning
Strategies by university students. It is made up of two scales, six sub scales, twenty-five
strategies and eighty-eight items with response, Very disagree, disagree, undecided, all
rigth, strongly agree. Also, for this population, It is investigated what was its Academic
Performance, reflected in its general average of qualifications, obtained until the eighth
semester of the degree; The range of these was of 6.91 to 9.1
Activation of Nrf2-Regulated Glutathione Pathway Genes by Ischemic Preconditioning
Prophylactic pharmacological activation of astrocytic gene expression driven by the transcription factor Nrf2 boosts antioxidant defences and protects against neuronal loss in ischemia and other disease models. However, the role of Nrf2 in mediating endogenous neuroprotective responses is less clear. We recently showed that Nrf2 is activated by mild oxidative stress in both rodent and human astrocytes. Moreover, brief exposure to ischemic conditions was found to activate Nrf2 both in vivo and in vitro, and this was found to contribute to neuroprotective ischemic preconditioning. Here we show that transient ischemic conditions in vitro and in vivo cause an increase in the expression of Nrf2 target genes associated with the glutathione pathway, including those involved in glutathione biosynthesis and cystine uptake. Taken together, these studies indicate that astrocytic Nrf2 may represent an important mediator of endogenous neuroprotective preconditioning pathways
Deficiency of Nrf2 exacerbates white matter damage and microglia/macrophage levels in a mouse model of vascular cognitive impairment
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