Present and future global distributions of the marine Cyanobacteria Prochlorococcus and Synechococcus.

The Cyanobacteria Prochlorococcus and Synechococcus account for a substantial fraction of marine primary production. Here, we present quantitative niche models for these lineages that assess present and future global abundances and distributions. These niche models are the result of neural network, nonparametric, and parametric analyses, and they rely on >35,000 discrete observations from all major ocean regions. The models assess cell abundance based on temperature and photosynthetically active radiation, but the individual responses to these environmental variables differ for each lineage. The models estimate global biogeographic patterns and seasonal variability of cell abundance, with maxima in the warm oligotrophic gyres of the Indian and the western Pacific Oceans and minima at higher latitudes. The annual mean global abundances of Prochlorococcus and Synechococcus are 2.9 ± 0.1 × 10(27) and 7.0 ± 0.3 × 10(26) cells, respectively. Using projections of sea surface temperature as a result of increased concentration of greenhouse gases at the end of the 21st century, our niche models projected increases in cell numbers of 29% and 14% for Prochlorococcus and Synechococcus, respectively. The changes are geographically uneven but include an increase in area. Thus, our global niche models suggest that oceanic microbial communities will experience complex changes as a result of projected future climate conditions. Because of the high abundances and contributions to primary production of Prochlorococcus and Synechococcus, these changes may have large impacts on ocean ecosystems and biogeochemical cycles.

Confirmatory Factor Analysis of Comorbidity between Depression and Aggression in a Child-Adolescent Community Sample: Nosological, Prognosis and Etiological Implications.

Comorbidity between depression and aggression in the child-adolescent population remains a controversial phenomenon. To our knowledge, no longitudinal study using structural equation modeling (SEM) has confirmed whether the relationship between depression and aggression is due to the fact that they share internalizing and externalizing supraordinal factors at the level of the syndrome or is due to the fact that they share common characteristics in relation to an underlying factor at the level of symptoms. We examined longitudinal comorbid relationships in a community sample (N = 251) at three waves ages from 10 to 13 years. The SEM showed that longitudinally, the comorbidity between depression and aggression is due to the fact that they share characteristics of the same underlying factor at the symptom level. These results have implications for the classification, diagnosis, and treatment of comorbidity between depression and aggression in a child-adolescent population.

Análisis longitudinal de la comorbilidad entre depresión y agresión: Cronicidad y severidad en sujetos de 11 a 13 años / Longitudinal analysis of comorbidity between depression and aggression: Chronicity and severity in individuals 11 to 13 years

La comorbilidad entre depresión y agresión infanto-adolescente ha sido contrastada básicamente a un nivel estadístico. Sin embargo, pocos estudios han comprobado de manera longitudinal otra de las premisas fundamentales que permite establecer la comorbilidad: la sinergia, es decir, la acción conjunta de dos o más trastornos que se traduce en una severidad y cronicidad superior a las generadas por la suma de los efectos individuales. Mediante un diseño longitudinal a lo largo de 3 años se examinó la severidad y cronicidad de un grupo de sujetos comórbidos depresivos - agresivos. Se analizaron los niveles de depresión y agresión, así como el papel del sexo en estas relaciones. La evaluación se realizó a través de autoinformes en una muestra de 525 sujetos de edades comprendidas entre los 11 y 13 años. La muestra fue aleatoriamente seleccionada de diferentes colegios de la Comunidad de Madrid (España). Los resultados muestran que la depresión y agresión se relacionan de manera estadísticamente significativa. Los sujetos comórbidos exhiben una cronicidad de mayor duración en las respuestas agresivas que en las depresivas. La severidad en los sujetos comórbidos es mayor en las respuestas agresivas de tipo total y verbal, así como en las depresivas. El sexo no ejerce ningún efecto significativo. Se concluye que los datos indican la importancia de explorar la comorbilidad con diferentes tipos de agresión, especialmente la verbal, y en diferentes grupos de edad. Se discute la necesidad de atender a los síntomas subyacentes al trastorno principal en afectados de larga duración, ya que a la expresión de uno de los trastornos puede subyacer la cronicidad asociada a la comorbilidad con importantes repercusiones para su diagnóstico y tratamiento.

The comorbidity between depression and aggression in children and adolescents is an issue that has sparked controversy as its existence has important implications for the validity of the classification systems, for the establishment of explanatory models, the design of new treatments as well as in the final outcome which the comorbid person presents in these in comparison with conventional treatments. In addition, the prevalence rates in depressive-aggressive comorbidity are significant, oscillating between 7.97 and 10.91%. Therefore, the study of comorbidity becomes necessary and the lack of studies focusing on the subject comes as a surprise. Perhaps one of the main problems concerning the research of comorbidity lies in the fact that most of the studies do not validate the clinical criteria that focuses on the principle of synergy, as Clark and Watson had established in Tripartite model, since doing so would require longitudinal studies measuring the effects of a commorbid disorder in contrast to those where there is no comorbidity to be found. In addition to clinical judgment, the Tripartite model demands a further statistic indicating the existence of a significant correlation between those synergistic disorders, which is the one on which most studies have been focusing. This type of results, based solely on clinical judgment, mainly through cross-sectional studies, has not allowed to implement another type of results, as suggested by the Tripartite model, that would have helped to establish clinical and diagnostic criteria through dimensional self-assessment tools which are closer to a reality in child and adolescent assessment where comorbidity is rather the rule than the exception. Therefore, that kind of study, using a longitudinal design over a period of three years, will help expand those cross-sectional ones, which will allow for examining whether there is a significant association, as well as a synergy that attests to the existence of an aggressive-depressive comorbidity on both, statistical and clinical level. In order to do so this study examined the severity and chronicity of a group of comorbid depressive-aggressive persons. In addition, the levels of depression and aggression and the role of sex within these relationships were analyzed. The sample, randomly selected from different schools in the Community of Madrid (Spain), comprised 525 individuals ranging from 11 to 13 years old, 58.9% female, the family structure was mostly biparental (92%) and the vast majority belonged to a middle class environment (85%). Depression and aggression were assessed through specific types of self-report questionnaires for children and adolescents, both in their Spanish version. The results support the statistical basis, since depression and aggression exhibit a significant positive and moderate association ranging between .11 and .24, in which the fact that the found association was higher within verbal aggression than in the physical one among all ages with the exception of the group of subjects to testing aged 12 needs to be stressed. With regards to the clinical criteria, the results provide partial support, as comorbid subjects exhibit a longer duration in chronic aggressive symptoms than those other groups affected only by depression or aggression, while they are similar to those of merely depressive subjects in the symptoms indicating a depression. Regarding severity, comorbid subjects show a higher level within the field of totally and verbally aggressive symptoms, as well as in the depressive ones which makes their physical aggression comparable to the one found in the test group of total aggression, hence, the data partially support the clinical standard. The tested person's sex, however, is of no significant meaning for the outcome. In conclusion, the data indicates the importance of exploring the comorbidity of different types of aggression, particularly the verbal one, and within different age groups. The need for addressing the underlying primary disorder symptoms in long-term affected patients is discussed, since chronic comorbidity may underlie the expression of one of the disorders and entail important implications for diagnosis and treatment.