TRIMETHYLGUANOSINE SYNTHASE1 mutations decanalize female germline development in Arabidopsis.

Here, we report the characterization of a plant RNA methyltransferase, orthologous to yeast trimethylguanosine synthase1 (Tgs1p) and whose downregulation was associated with apomixis in Paspalum grasses. Using phylogenetic analyses and yeast complementation, we determined that land plant genomes all encode a conserved, specific TGS1 protein. Next, we studied the role of TGS1 in female reproduction using reporter lines and loss-of-function mutants in Arabidopsis thaliana. pAtTGS1:AtTGS1 reporters showed a dynamic expression pattern. They were highly active in the placenta and ovule primordia at emergence but, subsequently, showed weak signals in the nucellus. Although expressed throughout gametophyte development, activity became restricted to the female gamete and was also detected after fertilization during embryogenesis. TGS1 depletion altered the specification of the precursor cells that give rise to the female gametophytic generation and to the sporophyte, resulting in the formation of a functional aposporous-like lineage. Our results indicate that TGS1 participates in the mechanisms restricting cell fate acquisition to a single cell at critical transitions throughout the female reproductive lineage and, thus, expand our current knowledge of the mechanisms governing female reproductive fate in plants.

ORIGIN OF RECOGNITION COMPLEX 3 controls the development of maternal excess endosperm in the Paspalum simplex agamic complex (Poaceae).

Pseudogamous apomixis in Paspalum simplex generates seeds with embryos genetically identical to the mother plant and endosperms deviating from the canonical 2(maternal):1(paternal) parental genome contribution into a maternal excess 4m:1p genome ratio. In P. simplex, the gene homologous to that coding for subunit 3 of the ORIGIN OF RECOGNITION COMPLEX (PsORC3) exists in three isogenic forms: PsORC3a is apomixis specific and constitutively expressed in developing endosperm whereas PsORCb and PsORCc are up-regulated in sexual endosperms and silenced in apomictic ones. This raises the question of how the different arrangement and expression profiles of these three ORC3 isogenes are linked to seed development in interploidy crosses generating maternal excess endosperms. We demonstrate that down-regulation of PsORC3b in sexual tetraploid plants is sufficient to restore seed fertility in interploidy 4n×2n crosses and, in turn, its expression level at the transition from proliferating to endoreduplication endosperm developmental stages dictates the fate of these seeds. Furthermore, we show that only when being maternally inherited can PsORC3c up-regulate PsORC3b. Our findings lay the basis for an innovative route-based on ORC3 manipulation-to introgress the apomictic trait into sexual crops and overcome the fertilization barriers in interploidy crosses.

Immune response and oxidative stress of shrimp Litopenaeus vannamei at different moon phases.

Moon phases influence the molting process of shrimp, which affect other physiological processes as immune response. This study analyzed some parameters of immune response: total hemocytes counts (THC), hemolymph clotting time and superoxide anion (O2-) production, total protein concentration, superoxide dismutase activity, and the presence of Vibrio spp. in Litopenaeus vannamei at different moon phases. The highest percentage of organisms in intermolt stage was observed in the first quarter moon phase (95%). The highest THC was observed at new moon phase, which was significantly different (p < 0.05) than that observed at the third quarter phase. Hemolymph clotting time and CFU values of Vibrio spp. showed no significant difference (p > 0.05) between different moon phases. The higher (p < 0.05) mean O2- production value (0.400 ± 0.168 nmol min-1 mL-1) was determined in hepatopancreas at new moon phase. No relationship was observed between O2- and SOD activity, indicating that this antioxidant response was enough to counteract the influence of oxidative stress in L. vannamei at different moon phases.

Escala Abreviada de Personalidad y Acontecimientos Vitales para la detección de los intentos de suicidio / Short Personality and Life Event scale for detection of suicide attempters

Objetivo. Desarrollar una escala breve y fiable para identificar a las personas en riesgo de conducta suicida. Método. Diseño: estudio de caso-control. Muestra y centro: 182 individuos (61 personas que intentaron suicidarse, 57 controles psiquiátricos y 64 controles sanos) con una edad de 18 años o más, admitidos en la Unidad de Urgencias del Hospital Universitario Puerta de Hierro de Madrid, España. Mediciones: todos los participantes rellenaron un formulario que incluía sus características sociodemográficas y clínicas, y la Escala de Personalidad y Acontecimientos Vitales (27 cuestiones). Para evaluar los diagnósticos del Eje I, a todos los pacientes psiquiátricos (incluyendo a las personas que intentaron suicidarse) se les realizó la Entrevista Neuropsiquiátrica Internacional. Análisis estadístico: se aplicó estadística descriptiva para los factores sociodemográficos. Además, se aplicaron las pruebas de independencia de χ2 para evaluar las diferencias de las variables sociodemográficas y clínicas, y de la Escala de Personalidad y Acontecimientos Vitales entre grupos. Se llevó a cabo una regresión lineal escalonada con selección de variable retrospectiva para elaborar la escala abreviada de Personalidad y Acontecimientos Vitales (S-PLE). A fin de evaluar la precisión se realizó un análisis de ROC. Se evaluó la fiabilidad interna utilizando la α de Cronbach, y la fiabilidad externa mediante un procedimiento de prueba-reprueba. Resultados. La escala S-PLE, que se compone únicamente de 6 cuestiones, reflejó un buen desempeño al discriminar los controles sanos, los controles psiquiátricos y los intentos de suicidio en una muestra independiente. Por ejemplo, la escala S-PLE discriminó a las personas que intentaron suicidarse y a las que no lo hicieron en el pasado, con una sensibilidad del 80% y una especificidad del 75%. El área bajo la curva ROC fue del 88%. Un análisis factorial extrajo solamente un factor, lo que revela la dimensión única de la escala S-PLE. Además, la escala S-PLE aporta valores de fiabilidad interna y externa que se incluyen dentro de los rangos débil (prueba-reprueba: 0,55) y aceptable (α de Cronbach: 0,65). El tiempo de realización es de alrededor de un minuto. Conclusiones. La escala S-PLE es un instrumento útil y preciso para calcular el riesgo de conducta suicida en centros asistenciales donde escasea el tiempo (AU)

Objective. To develop a brief and reliable psychometric scale to identify individuals at risk for suicidal behaviour. Method. Design: Case-control study. Sample and setting: 182 individuals (61 suicide attempters, 57 psychiatric controls, and 64 psychiatrically healthy controls) aged 18 or older, admitted to the Emergency Department at Puerta de Hierro University Hospital in Madrid, Spain. Measures: All participants completed a form including their socio-demographic and clinical characteristics, and the Personality and Life Events scale (27 items). To assess Axis I diagnoses, all psychiatric patients (including suicide attempters) were administered the Mini International Neuropsychiatric Interview. Statistical analysis: Descriptive statistics were computed for the socio-demographic factors. Additionally, χ2 independence tests were applied to evaluate differences in socio-demographic and clinical variables, and the Personality and Life Events scale between groups. A stepwise linear regression with backward variable selection was conducted to build the Short Personality Life Event (S-PLE) scale. In order to evaluate the accuracy, a ROC analysis was conducted. The internal reliability was assessed using Cronbach's α, and the external reliability was evaluated using a test-retest procedure. Results. The S-PLE scale, composed of just 6 items, showed good performance in discriminating between medical controls, psychiatric controls and suicide attempters in an independent sample. For instance, the S-PLE scale discriminated between past suicide and past non-suicide attempters with sensitivity of 80% and specificity of 75%. The area under the ROC curve was 88%. A factor analysis extracted only one factor, revealing a single dimension of the S-PLE scale. Furthermore, the S-PLE scale provides values of internal and external reliability between poor (test-retest: 0.55) and acceptable (Cronbach's α: 0.65) ranges. Administration time is about one minute. Conclusions. The S-PLE scale is a useful and accurate instrument for estimating the risk of suicidal behaviour in settings where the time is scarce (AU)

Short Personality and Life Event scale for detection of suicide attempters.

OBJECTIVE: To develop a brief and reliable psychometric scale to identify individuals at risk for suicidal behaviour. DESIGN: Case-control study. SAMPLE AND SETTING: 182 individuals (61 suicide attempters, 57 psychiatric controls, and 64 psychiatrically healthy controls) aged 18 or older, admitted to the Emergency Department at Puerta de Hierro University Hospital in Madrid, Spain. MEASURES: All participants completed a form including their socio-demographic and clinical characteristics, and the Personality and Life Events scale (27 items). To assess Axis I diagnoses, all psychiatric patients (including suicide attempters) were administered the Mini International Neuropsychiatric Interview. STATISTICAL ANALYSIS: Descriptive statistics were computed for the socio-demographic factors. Additionally, χ(2) independence tests were applied to evaluate differences in socio-demographic and clinical variables, and the Personality and Life Events scale between groups. A stepwise linear regression with backward variable selection was conducted to build the Short Personality Life Event (S-PLE) scale. In order to evaluate the accuracy, a ROC analysis was conducted. The internal reliability was assessed using Cronbach's α, and the external reliability was evaluated using a test-retest procedure. RESULTS: The S-PLE scale, composed of just 6 items, showed good performance in discriminating between medical controls, psychiatric controls and suicide attempters in an independent sample. For instance, the S-PLE scale discriminated between past suicide and past non-suicide attempters with sensitivity of 80% and specificity of 75%. The area under the ROC curve was 88%. A factor analysis extracted only one factor, revealing a single dimension of the S-PLE scale. Furthermore, the S-PLE scale provides values of internal and external reliability between poor (test-retest: 0.55) and acceptable (Cronbach's α: 0.65) ranges. Administration time is about one minute. CONCLUSIONS: The S-PLE scale is a useful and accurate instrument for estimating the risk of suicidal behaviour in settings where the time is scarce.

Are major repeater patients addicted to suicidal behavior?

The literature provides support for the hypothesis that some major repeaters (individuals with >=5 lifetime suicide attempts) are addicted to suicidal behavior (SB). This study explores whether major repeaters are addicted to SB or not using 7 criteria: tolerance (Criterion 1), withdrawal (Criterion 2), loss of control (Criterion 3), problems in quitting/cutting down (Criterion 4), much time spent using (Criterion 5), substantial reduction in activities (Criterion 6), and adverse physiological/physical consequences (Criterion 7). Total dependence on SB was indicated by the presence of 3 or more of the 7 criteria in the last 12 months. This cross-sectional study at Puerta de Hierro University Hospital (Madrid, Spain) recruited 118 suicide attempters including 8 major repeaters (7%, 8/118), who were all females. The association between each SB addiction criterion, physiological dependence and total dependence with major repeater status was tested for significance and for effect size with odds ratios (ORs) and their 95% confidence intervals. As hypothesized, major repeaters met significantly higher frequency of criteria for total dependence on SB, OR=62.9 (6.4-615). A backward stepwise logistic regression model was used to provide an OR between major repeater status and total dependence status corrected by confounding variables. Age, panic disorder without agoraphobia, borderline personality disorder, history of psychiatric inpatient admission, and total dependence on SB were introduced as independent variables with major repeater status as the dependent variable. The model selected total dependence and age as the remaining significant variables in the last step. Accordingly, major repeaters appear to be addicted to SB.

Are major repeater patients addicted to suicidal behavior? / ¿Están los grandes repetidores adictos a los comportamientos suicidas?

The literature provides support for the hypothesis that some major repeaters (individuals with ≥5 lifetime suicide attempts) are addicted to suicidal behavior (SB). This study explores whether major repeaters are addicted to SB or not using 7 criteria: tolerance (Criterion 1), withdrawal (Criterion 2), loss of control (Criterion 3), problems in quitting/cutting down (Criterion 4), much time spent using (Criterion 5), substantial reduction in activities (Criterion 6), and adverse physiological/physical consequences (Criterion 7). Total dependence on SB was indicated by the presence of 3 or more of the 7 criteria in the last 12 months. This cross-sectional study at Puerta de Hierro University Hospital (Madrid, Spain) recruited 118 suicide attempters including 8 major repeaters (7%, 8/118), who were all females. The association between each SB addiction criterion, physiological dependence and total dependence with major repeater status was tested for significance and for effect size with odds ratios (ORs) and their 95% confidence intervals. As hypothesized, major repeaters met significantly higher frequency of criteria for total dependence on SB, OR=62.9 (6.4-615). A backward stepwise logistic regression model was used to provide an OR between major repeater status and total dependence status corrected by confounding variables. Age, panic disorder without agoraphobia, borderline personality disorder, history of psychiatric inpatient admission, and total dependence on SB were introduced as independent variables with major repeater status as the dependent variable. The model selected total dependence and age as the remaining significant variables in the last step. Accordingly, major repeaters appear to be addicted to SB

La escasa literatura existente sugiere que los «grandes repetidores» (individuos con 5 intentos de suicidio a lo largo de la vida) pueden ser considerados «adictos» a los comportamientos suicidas. Este estudio explora si los grandes repetidores sufren una adicción a los comportamientos suicidas usando 7 criterios: tolerancia (Criterio 1), abstinencia (Criterio 2), pérdida de control (Criterio 3), problemas para dejar de tener o disminuir esos comportamientos (Criterio 4), uso de tiempo excesivo (Criterio 5), reducción importante de actividades (Criterio 6), y consecuencias físicas adversas (Criterio 7). La dependencia total a los comportamientos suicidas era diagnosticada si el sujeto cumplía 3 o más de los 7 criterios en los últimos 12 meses. Se trata de un estudio transversal realizado íntegramente en el Hospital Universitario Puerta de Hierro (Madrid, Spain) , donde fueron reclutados 118 individuos que se presentaron en los servicios de urgencia por un intento de suicidio, incluyendo 8 grandes repetidores (7%, 8/118), siendo todos ellos mujeres. Se estimó si había asociaciones estadísticamente significativas y el tamaño del efecto con la razón de oportunidades y los intervalos de confianza (95%)entre cada uno de los criterios de adicción a los comportamientos suicidas, la dependencia fisiológica, y la dependencia total. Nuestra hipótesis se verificó, ya que los grandes repetidores presentaron con mayor frecuencia criterios para la dependencia a las conductas suicidas, OR=62.9 (6.4-615). Usamos un modelo de regresión logística para estamiar el riesgo de la asociación entre ser un gran repetidor y la dependencia total corregido por diferentes variables. La edad, el trastorno de pánico sin agorafobia, el trastorno de personalidad límite, la historia de ingresos previos en unidad de hospitalización psiquiátrica, y la dependencia total a los comportamientos suicidas fueron introducidos como variables independientes y la categoría de grandes repetidores como variable dependiente. El modelo final seleccionó la dependencia total y la edad como las variables estadísticamente significativas en el último paso. En conclusión, nuestro estudio sugiere que los grandes repetidores podrían ser individuos adictos a los comportamientos suicidas