97 research outputs found
Influencia de la fertilización en el crecimiento de radicchio "Rosso di Chioggia" cultivado en dos ambientes diferentes
Este trabajo evalúa la influencia de la
fertilización en radicchio tipo "Rosso de Chioggia"
(precocidad media) sobre algunos Ãndices de
crecimiento. Se realizaron ensayos durante dos
campañas en Rovigo (Italia) y una en Mendoza
(Argentina), aplicándose dosis crecientes de
NPK, identificadas como N0P0K0, N1P1K1,
N2P2K2, en Mendoza y en Rovigo, además,
N3P2K2. Durante el cultivo se calcularon
Ãndices de crecimiento como: relative growth
rate (RGR), net assimilation rate (NAR), leaf
area ratio (LAR), specific leaf area (SLA), leaf
weigh ratio (LWR), crop growth ratio (CGR), leaf
area index (LAI) and leaf area duration (LAD).
En Mendoza, el CGR estuvo fuertemente
influenciado por NAR desde el trasplante hasta
alcanzar 776 grados dÃas (GDD); desde 1052 a
1653 GDD el CGR fue afectado por el LAI el cual
aumentó marcadamente debido a las condiciones
ambientales favorables. Entre los 1052 y 1653
GDD el incremento del LAI determinó una
reducción en la eficiencia fotosintética. En Rovigo,
la tendencia de los Ãndices fue disÃmil en los
dos años, encontrándose respuestas diferentes
en LAR y en SLA. En el segundo año, el CGR
siempre arrojó valores más altos, mientras que
NAR no difirió en ninguno de los años. En la
segunda mitad del ciclo, CGR estuvo fuertemente
asociado a una menor eficiencia fotosintética,
debido a la formación de la cabeza. Valores
elevados de LAI indicaron una extensión del ciclo,
retrasando la formación de la cabeza. Las plantas
alcanzaron la madurez comercial con LWR entre
0,35 - 0,40 g g-1. En ambos ambientes, no se
observó claramente el efecto de la fertilización
sobre los Ãndices; si bien las dosis más altas
mostraron mayor actividad de crecimiento en las
etapas tempranas.This study evaluated the influence
of fertilization on some growth indexes in
radicchio "Rosso di Chioggia". The trial was
conducted in Rovigo (Italy) for two years and in
Mendoza (Argentina) for one year. Increasing
doses of macronutrients were considered,
identified as N0P0K0, N1P1K1, N2P2K2
and, only in Rovigo, N3P2K2. Some indexes
related to growth analysis: relative growth rate
(RGR), net assimilation rate (NAR), leaf area
ratio (LAR), specific leaf area (SLA), leaf weigh
ratio (LWR), crop growth ratio (CGR), leaf
area index (LAI) and leaf area duration (LAD)
were calculated during the growing cycle. At
Mendoza CGR was strongly influenced by
NAR from transplant until 776 growth degree
days (GDD). After that moment, CGR was
affected by LAI that increased markedly due
to favourable environmental conditions. From
1052 to 1653 GDD the high increase of LAI
determined a reduction in photosynthetic
efficiency. At Rovigo the trends in index values
showed differences between the two years
considered, especially in LAR and SLA. In the
second year CGR had always higher values;
mainly due to higher LAI values, since NAR did
not differ significantly during the years. In the
second half of the growing cycle, CGR was
instead strongly linked to a contraction of
photosynthetic effectiveness, due to head
formation. High LAI values showed a growing
cycle extension to the detriment of early head
formation. It was also observed that when
LWR is around 0.35 - 0.40 g g-1, the plant
reaches marketable maturation and is ready
to be harvested. In both environments, no
clear effects of fertilization were observed
on the growth indexes. In any case highly
fertilized plants showed higher growing
activity especially at the beginning of the
growing cycle.Fil: Filippini, MarÃa Flavia.
Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Departamento de IngenierÃa AgrÃcolaFil: Nicoletto, Carlo.
Università degli Studi di Padova (Italia). Dipartimento Territorio e Sistemi Agro-ForestaliFil: Sambo, Paolo.
Università degli Studi di Padova (Italia). Dipartimento Territorio e Sistemi Agro-ForestaliFil: Cavagnaro, Juan Bruno.
Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Departamento de Ciencias BiológicasFil: Pimpini, Ferdinando.
Università degli Studi di Padova (Italia). Dipartimento Territorio e Sistemi Agro-Forestal
Unexplained falls are frequent in patients with fall-related injury admitted to Orthopaedic wards: the UFO Study (Unexplained Falls in Older patients)
To evaluate the incidence of unexplained falls in elderly patients affected by fall-related fractures admitted to orthopaedic wards, we recruited 246 consecutive patients older than 65 (mean age 82 \ub1 7 years, range 65-101). Falls were defined "accidental" (fall explained by a definite accidental cause), "medical" (fall caused directly by a specific medical disease), "dementia-related" (fall in patients affected by moderate-severe dementia), and "unexplained" (nonaccidental falls, not related to a clear medical or drug-induced cause or with no apparent cause). According to the anamnestic features of the event, older patients had a lower tendency to remember the fall. Patients with accidental fall remember more often the event. Unexplained falls were frequent in both groups of age. Accidental falls were more frequent in younger patients, while dementia-related falls were more common in the older ones. Patients with unexplained falls showed a higher number of depressive symptoms. In a multivariate analysis a higher GDS and syncopal spells were independent predictors of unexplained falls. In conclusion, more than one third of all falls in patients hospitalized in orthopaedic wards were unexplained, particularly in patients with depressive symptoms and syncopal spells. The identification of fall causes must be evaluated in older patients with a fall-related injury
Evaluation of the SAR distribution in the human head for cellular phones used in a partially closed environment
The purpose of this paper is to calculate the specific absorption rate (SAR) distribution in a human head exposed to the electromagnetic field emitted from a handheld cellular phone operating in the 900 MHz range in a partially closed environment. The environment could be, for example, the interior of a car, a condition of exposure which is largely diffused nowadays. The presence of reflecting surfaces near the phone modifies the current distribution on, and the emitting properties of, the phone antenna. Therefore, the distribution of the absorbed power inside the head is different from that absorbed in the free space exposure condition. The finite-difference time-domain (FDTD) method has been used to evaluate the SAR in a realistic anatomically based model of the human head for different antenna-handset configurations and for different antenna-head distances. The environmental effects have been simulated through partially or totally reflecting walls located in various positions with reference to the phone. It is found that the presence of a horizontal reflecting wall over the head decreases the SAR values in the part of the head directly exposed to the phone antenna, while it increases the SAR values in the part not directly exposed. On the contrary, the presence of a vertical wall, located in proximity of the phone and parallel to it, raises the SAR values everywhere into the hea
Assessment of the potential risk for humans exposed to millimeter-wave wireless LANs: the power absorbed in the eye
This paper deals with the interaction between a millimeter-wavelength plane wave and the human eye. The study has been conducted utilizing the finite difference time domain (FDTD) numerical technique, and an accurate eye model obtained through photographic images of the human head. A partly automatic procedure has been developed to obtain the FDTD-compatible eye model. The dielectric properties of the human tissues at millimeter wavelengths have been extrapolated from experimental data available at lower frequencies and by using Debye’s dispersion equation. The power distribution in the exposed eye has been calculated in both conditions of closed and open eye, and the results have been compared with the limits settled by some of the most recognized safety standards for human exposure
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