14 research outputs found
Mejoras en el diseño agronómico de la instalación de riego dirigidas al aumento de la productividad técnica y económica del agua en limonero temprano
El objetivo del trabajo fue incrementar la productividad en limonero temprano mediante mejoras en el diseño agronómico de la red de riego. El ensayo se llevó a cabo en una parcela experimental en Torre Pacheco (Murcia), en árboles adultos de limonero ‘Fino 49’ injertados sobre Citrus macrophylla Wester. Se han evaluado dos diseños del sistema de riego: diseño convencional (2L), con dos tuberías portagoteros (6 goteros árbol-1); y un diseño con mayor superficie mojada (3L), con tres tuberías (9 goteros árbol-1). Partiendo de los resultados agronómicos, se ha realizado un análisis económico comparativo entre dos diseños del sistema de riego. El diseño 3L fue el más productivo técnica y económicamente. El Producto Bruto Económico (PBE) fue un 14% superior en el diseño 3L respecto al 2L; el Producto Bruto Técnico (PBT) lo fue en un 6,2%. Este resultado se debe a dos motivos: por un lado y en mayor medida, al incremento en la proporción de limón de primer corte del diseño 3L y, por otro lado, a la disminución de limón derivado a la industria. El Margen Bruto (MB) sigue la misma pauta que el Producto Bruto (PB), ya que los costes diferenciales (CD) son de poca envergadura. El precio ponderado del kg de limón medio (PBE/PBT) es de 0,367 € kg-1 y 0,341 € kg-1, en 3L y 2L, respectivamente, y supone un ingreso de 2.631 € extras por hectárea y año a favor del sistema 3L. Por último, resaltar que el diseño 3L destaca principalmente por ser es más productivo económicamente, en relación al agua aplicada (€ m-3)
Aplicación de la oxifertirrigación para optimizar los recursos hídricos en cítricos, basado en la aplicación de peróxido de hidrógeno en el agua de riego
En este trabajo se estudia la respuesta fisiológica y agronómica de la aplicación de la
oxifertirrigación química, basada en la aplicación de peróxido de hidrógeno como fuente de
oxígeno a nivel radicular en cítricos. El ensayo tuvo lugar durante dos campañas (2018-2019
y 2019-2020) en árboles adultos de mandarino híbrido ‘Ortanique’ ubicados en una parcela
experimental del IMIDA en Torre Pacheco (Murcia). Se establecieron dos tratamientos, un
tratamiento ‘Control’ (0 ppm de H2O2) y otro identificado como ‘OXI’ (50-100 ppm de H2O2
durante todo el ciclo de cultivo). Ambos tratamientos recibieron la misma cantidad de agua y
de fertilizante. El H2O2 se aplicó de forma continua con una bomba dosificadora a la red de
riego. Los resultados más destacados mostraron que el estado hídrico de los árboles del
tratamiento ‘OXI’ fue muy similar al control. Respecto a los parámetros de intercambio
gaseoso, la aplicación de H2O2 estimuló una mayor apertura estomática en el mes de
septiembre de ambas campañas. Sin embargo, las ligeras alteraciones fisiológicas no han
supuesto cambios sustanciales en la biometría de la planta. En la segunda campaña, la
aplicación de H2O2 en el riego favoreció la acumulación de N, K y Fe en hoja, lo que permitiría
reducir la dosis de fertilizante. La respuesta productiva y la eficiencia en el uso del agua no
presentaron una clara mejora a la aplicación de H2O2 en el agua de riego. Los mayores niveles
de N en el tratamiento ‘OXI’ afectaron negativamente a la calidad del fruto, reduciendo el
porcentaje de zumo y aumentando el porcentaje de corteza. En cambio, la aplicación de H2O2
disminuyó el índice de madurez de la fruta, lo que resulta interesante de cara a retrasar la
recolección en variedades tardías
Riego de un cultivo de citricos con agua marina desalinizada. resultados preliminares en suelo y planta
La escasez de agua y la creciente presión sobre los recursos hídricos en las regiones
semiáridas ha extendido la utilización para el riego de recursos hídricos no convencionales,
como el agua marina desalinizada (AMD). Debido a su composición en Cl-, Na+ y B3+, el riego
con AMD podría causar problemas agronómicos y afectar al suelo y a los cultivos a medio y
largo plazo. En este estudio, se regó una parcela de mandarinos durante 20 meses con (i)
agua proporcionada por la Comunidad de Regantes del Campo de Cartagena (CR), (ii) agua
marina desalinizada (AMD) y (iii) mezcla de agua 50% CR y 50% AMD (AM). Se evaluó el
efecto sobre la dinámica y acumulación de los iones tóxicos Cl-, Na+ y B3+ en el suelo y en la
planta. La [B3+] del agua AMD fue superior a la de CR, acumulándose en el suelo, con una
concentración un 25% superior a la encontrada con CR al final del ensayo. La [B3+] en la capa
superficial del suelo se correlacionó con la [B3+] en el agua y con la [B3+] en la hoja. Aunque
tras 20 meses los árboles regados con AMD tuvieron una [B3+] foliar un 25% superior a la de
árboles regados con CR, no presentaron síntomas de toxicidad. Las [Cl-] y [Na+] del agua
fueron similares en los tres tipos de agua, superando los umbrales a partir de los cuales
pueden producir toxicidad en cítricos. Las concentraciones de Cl- y Na+ en hoja permanecieron
por debajo del umbral de toxicidad establecido para cítricos. Los resultados obtenidos son
preliminares ya que este estudio debería extenderse durante un periodo más largo para
obtener datos más concluyentes acerca de los efectos a largo plazo de la utilización de AMD
tanto en el suelo como en la planta
The V471A polymorphism in autophagy-related gene ATG7 modifies age at onset specifically in Italian Huntington disease patients
The cause of Huntington disease (HD) is a polyglutamine repeat expansion of more than 36 units in the huntingtin protein, which is inversely correlated with the age at onset of the disease. However, additional genetic factors are believed to modify the course and the age at onset of HD. Recently, we identified the V471A polymorphism in the autophagy-related gene ATG7, a key component of the autophagy pathway that plays an important role in HD pathogenesis, to be associated with the age at onset in a large group of European Huntington disease patients. To confirm this association in a second independent patient cohort, we analysed the ATG7 V471A polymorphism in additional 1,464 European HD patients of the “REGISTRY” cohort from the European Huntington Disease Network (EHDN). In the entire REGISTRY cohort we could not confirm a modifying effect of the ATG7 V471A polymorphism. However, analysing a modifying effect of ATG7 in these REGISTRY patients and in patients of our previous HD cohort according to their ethnic origin, we identified a significant effect of the ATG7 V471A polymorphism on the HD age at onset only in the Italian population (327 patients). In these Italian patients, the polymorphism is associated with a 6-years earlier disease onset and thus seems to have an aggravating effect. We could specify the role of ATG7 as a genetic modifier for HD particularly in the Italian population. This result affirms the modifying influence of the autophagic pathway on the course of HD, but also suggests population-specific modifying mechanisms in HD pathogenesis
Clinical manifestations of intermediate allele carriers in Huntington disease
Objective: There is controversy about the clinical consequences of intermediate alleles (IAs) in Huntington disease (HD). The main objective of this study was to establish the clinical manifestations of IA carriers for a prospective, international, European HD registry. Methods: We assessed a cohort of participants at risk with <36 CAG repeats of the huntingtin (HTT) gene. Outcome measures were the Unified Huntington's Disease Rating Scale (UHDRS) motor, cognitive, and behavior domains, Total Functional Capacity (TFC), and quality of life (Short Form-36 [SF-36]). This cohort was subdivided into IA carriers (27-35 CAG) and controls (<27 CAG) and younger vs older participants. IA carriers and controls were compared for sociodemographic, environmental, and outcome measures. We used regression analysis to estimate the association of age and CAG repeats on the UHDRS scores. Results: Of 12,190 participants, 657 (5.38%) with <36 CAG repeats were identified: 76 IA carriers (11.56%) and 581 controls (88.44%). After correcting for multiple comparisons, at baseline, we found no significant differences between IA carriers and controls for total UHDRS motor, SF-36, behavioral, cognitive, or TFC scores. However, older participants with IAs had higher chorea scores compared to controls (p 0.001). Linear regression analysis showed that aging was the most contributing factor to increased UHDRS motor scores (p 0.002). On the other hand, 1-year follow-up data analysis showed IA carriers had greater cognitive decline compared to controls (p 0.002). Conclusions: Although aging worsened the UHDRS scores independently of the genetic status, IAs might confer a late-onset abnormal motor and cognitive phenotype. These results might have important implications for genetic counseling. ClinicalTrials.gov identifier: NCT01590589
Suicidal ideation in a European Huntington's disease population
BACKGROUND: Previous studies indicate increased prevalences of suicidal ideation,
suicide attempts, and completed suicide in Huntington's disease (HD) compared
with the general population. This study investigates correlates and predictors of
suicidal ideation in HD.
METHODS: The study cohort consisted of 2106 HD mutation carriers, all
participating in the REGISTRY study of the European Huntington's Disease Network.
Of the 1937 participants without suicidal ideation at baseline, 945 had one or
more follow-up measurements. Participants were assessed for suicidal ideation by
the behavioural subscale of the Unified Huntington's Disease Rating Scale
(UHDRS). Correlates of suicidal ideation were analyzed using logistic regression
analysis and predictors were analyzed using Cox regression analysis.
RESULTS: At baseline, 169 (8.0%) mutation carriers endorsed suicidal ideation.
Disease duration (odds ratio [OR]=0.96; 95% confidence interval [CI]: 0.9-1.0),
anxiety (OR=2.14; 95%CI: 1.4-3.3), aggression (OR=2.41; 95%CI: 1.5-3.8), a
previous suicide attempt (OR=3.95; 95%CI: 2.4-6.6), and a depressed mood
(OR=13.71; 95%CI: 6.7-28.0) were independently correlated to suicidal ideation at
baseline. The 4-year cumulative incidence of suicidal ideation was 9.9%.
Longitudinally, the presence of a depressed mood (hazard ratio [HR]=2.05; 95%CI:
1.1-4.0) and use of benzodiazepines (HR=2.44; 95%CI: 1.2-5.0) at baseline were
independent predictors of incident suicidal ideation, whereas a previous suicide
attempt was not predictive.
LIMITATIONS: As suicidal ideation was assessed by only one item, and participants
were a selection of all HD mutation carriers, the prevalence of suicidal ideation
was likely underestimated.
CONCLUSIONS: Suicidal ideation in HD frequently occurs. Assessment of suicidal
ideation is a priority in mutation carriers with a depressed mood and in those
using benzodiazepines
Clinical and genetic characteristics of late-onset Huntington's disease
Background: The frequency of late-onset Huntington's disease (>59 years) is assumed to be low and the clinical course milder. However, previous literature on late-onset disease is scarce and inconclusive. Objective: Our aim is to study clinical characteristics of late-onset compared to common-onset HD patients in a large cohort of HD patients from the Registry database. Methods: Participants with late- and common-onset (30\u201350 years)were compared for first clinical symptoms, disease progression, CAG repeat size and family history. Participants with a missing CAG repeat size, a repeat size of 6435 or a UHDRS motor score of 645 were excluded. Results: Of 6007 eligible participants, 687 had late-onset (11.4%) and 3216 (53.5%) common-onset HD. Late-onset (n = 577) had significantly more gait and balance problems as first symptom compared to common-onset (n = 2408) (P <.001). Overall motor and cognitive performance (P <.001) were worse, however only disease motor progression was slower (coefficient, 120.58; SE 0.16; P <.001) compared to the common-onset group. Repeat size was significantly lower in the late-onset (n = 40.8; SD 1.6) compared to common-onset (n = 44.4; SD 2.8) (P <.001). Fewer late-onset patients (n = 451) had a positive family history compared to common-onset (n = 2940) (P <.001). Conclusions: Late-onset patients present more frequently with gait and balance problems as first symptom, and disease progression is not milder compared to common-onset HD patients apart from motor progression. The family history is likely to be negative, which might make diagnosing HD more difficult in this population. However, the balance and gait problems might be helpful in diagnosing HD in elderly patients
Suicidal ideation in a European Huntington's disease population
Previous studies indicate increased prevalences of suicidal ideation,
suicide attempts, and completed suicide in Huntington's disease (HD) compared
with the general population. This study investigates correlates and predictors of
suicidal ideation in HD.
METHODS: The study cohort consisted of 2106 HD mutation carriers, all
participating in the REGISTRY study of the European Huntington's Disease Network.
Of the 1937 participants without suicidal ideation at baseline, 945 had one or
more follow-up measurements. Participants were assessed for suicidal ideation by
the behavioural subscale of the Unified Huntington's Disease Rating Scale
(UHDRS). Correlates of suicidal ideation were analyzed using logistic regression
analysis and predictors were analyzed using Cox regression analysis.
RESULTS: At baseline, 169 (8.0%) mutation carriers endorsed suicidal ideation.
Disease duration (odds ratio [OR]=0.96; 95% confidence interval [CI]: 0.9-1.0),
anxiety (OR=2.14; 95%CI: 1.4-3.3), aggression (OR=2.41; 95%CI: 1.5-3.8), a
previous suicide attempt (OR=3.95; 95%CI: 2.4-6.6), and a depressed mood
(OR=13.71; 95%CI: 6.7-28.0) were independently correlated to suicidal ideation at
baseline. The 4-year cumulative incidence of suicidal ideation was 9.9%.
Longitudinally, the presence of a depressed mood (hazard ratio [HR]=2.05; 95%CI:
1.1-4.0) and use of benzodiazepines (HR=2.44; 95%CI: 1.2-5.0) at baseline were
independent predictors of incident suicidal ideation, whereas a previous suicide
attempt was not predictive.
LIMITATIONS: As suicidal ideation was assessed by only one item, and participants
were a selection of all HD mutation carriers, the prevalence of suicidal ideation
was likely underestimated.
CONCLUSIONS: Suicidal ideation in HD frequently occurs. Assessment of suicidal
ideation is a priority in mutation carriers with a depressed mood and in those
using benzodiazepines