Corticosterone mediates the condition-dependent component of melanin-based coloration

The handicap principle of sexual selection theory states that colourful phenotypic traits signal aspects of individual quality because only individuals in prime condition can afford to produce and bear conspicuous traits. Melanin-based pigments participate in the elaboration of many secondary sexual characters and, given their role in sexual selection, melanin-based coloration may therefore honestly reject individual quality. Although the expression of melanism is usually under genetic control, in some species it is condition dependent. However, the underlying physiological mechanism is yet unknown. Based on the negative feedback link between corticosterone and melanogenesis ( melanocortins, tyrosinase) in response to stressful environmental factors, we hypothesize that corticosterone mediates the condition-dependent component of melanism. This hypothesis predicts that stressful factors induce a rise in circulating corticosterone which inhibits the secretion of melanocortins and tyrosinase and in turn melanin production. We tested this prediction by manipulating the level of corticosterone at the time of melanin production in nestling barn owls, Tyto alba, a species showing heritable variation in the degree of phaeomelanism from reddish-brown to white. The finding that corticosterone-implanted nestlings produced feathers with less phaeomelanic coloration than placebo-implanted nestlings is consistent with the hypothesis that the environment-mediated reduction in the degree of melanism is, at least in part, caused by a rise in corticosterone. In species in which the expression of melanin-based coloration is condition dependent, we now need a test showing that individuals with less corticosterone and more melanin-based signals are individuals in better condition.

Enfermedades que afectan a la imagen corporal

Hoy en día la apariencia física juega un papel muy importante en nuestra sociedad, siendo considerado por muchos como un instrumento básico para alcanzar el éxito social y laboral. Sin embargo, el concepto de imagen corporal, a veces confundido con el de apariencia física, es un término que significa el sentimiento que cada persona tiene en relación a su propio cuerpo. Por ello, cualquier alteración en esta imagen influye en la autoestima de las personas comportando un gran impacto psicológico y emocional y colocando a la persona en una situación de crisis con una alta vulnerabilidad psicológica. Entre las diversas causas que pueden ocasionar dicha alteración, destacan la cirugía, las incapacidades y un amplio abanico de enfermedades degenerativas. Si bien todas tienen su importancia, en el siguiente trabajo se han querido destacar aquellas enfermedades consideradas como “raras” debido a su baja prevalencia y por tanto, con gran desconocimiento por parte de la sociedad. Además, otra de las características de estas enfermedades es que más que alterar el aspecto físico, lo que se produce es una separación entre el cuerpo y la mente, provocando sentimientos de gran incertidumbre debido al desconocimiento acerca de cuál será el siguiente aspecto de su vida que se verá cambiado debido a su enfermedad. De todas ellas, es la esclerosis lateral amiotrófica o ELA la escogida como motivo principal de estudio; es una enfermedad neurodegenerativa minoritaria, poco conocida, de causa desconocida y que actualmente no tiene cura por lo que genera a los pacientes y a las familias sentimientos de soledad, desamparo y exclusión social y económica. La enfermedad evoluciona rápidamente provocando parálisis generalizada y afectando por tanto, a la movilidad, al habla, la deglución, la respiración y al grado de dependencia; por lo tanto, el paciente necesitará un cuidador las 24 horas del día. Por el contrario, los sentidos y la capacidad cognitiva no se ven afectados de modo que el paciente es consciente en todo momento de la evolución de su enfermedad y de la pérdida progresiva de sus funciones.

Condition of the State of Iowa, 2010

A transcript of the Condition of the State of Iowa speech by Governor Chet Culver delivered at the State Capitol on January 12, 2010.

The Annual Condition of Education Report, 2007

The Annual Condition of Education Report includes an expanded Background Demographics section. This section contains information on population, economic, and social data, providing a comparison between Iowa, other states, and the Nation. Geographic Information System (GIS) maps are presented to allow the reader to easily compare between two or more geographies. In some instances, trends are also reported. Information displayed in this section was obtained from a variety of sources and is noted on each table or figure. In all areas, the most recent data available were used.

The Annual Condition of Education Report, 2008

The Annual Condition of Education Report includes an expanded Background Demographics section. This section contains information on population, economic, and social data, providing a comparison between Iowa, other states, and the Nation. Geographic Information System (GIS) maps are presented to allow the reader to easily compare between two or more geographies. In some instances, trends are also reported. Information displayed in this section was obtained from a variety of sources and is noted on each table or figure. In all areas, the most recent data available were used.

The Annual Condition of Education Report, 2009

The Annual Condition of Education Report includes an expanded Background Demographics section. This section contains information on population, economic, and social data, providing a comparison between Iowa, other states, and the Nation. Geographic Information System (GIS) maps are presented to allow the reader to easily compare between two or more geographies. In some instances, trends are also reported. Information displayed in this section was obtained from a variety of sources and is noted on each table or figure. In all areas, the most recent data available were used.

To say or not to say: a qualitative study on the disclosure of their condition by human immunodeficiency virus-positive adolescents.

PURPOSE: Human immunodeficiency virus (HIV)-positive adolescents face a number of challenges in dealing with their disease, treatment, and developmental tasks. This qualitative study describes some of the reasons why, and the extent to which, adolescents may or may not disclose their condition to others. METHODS: A semistructured interview lasting 40-110 minutes was conducted with each of 29 adolescents 12-20 years old, 22 female and seven male) living in Switzerland. Interviews were tape recorded and transcribed verbatim. The analysis of the content of interviews allowed us to identify salient topics (e.g., disclosure), which were then explored in detail. RESULTS: Of 29 participants, eight had not disclosed their condition to anyone outside the family, 19 had disclosed it to good friends, and 16 had disclosed it to some teachers. Four participants had engaged in public disclosure, and six of 10 sexually active teenagers disclosed their status to their partners. The attitudes toward disclosure among younger adolescents were mostly related to those of the parents, particularly the mother. Older adolescents, engaged in their search for autonomy, tended to decide independently what to say and to whom. Although foster/adoptive parents would often encourage disclosure, biological parents, especially HIV-positive mothers, insisted on not disclosing the adolescent's status for fear of stigma. CONCLUSION: The health care team should systematically address the issue of disclosure with the adolescent and his family (or foster parents), the aim being to balance the right of the adolescent and that adolescent's family to maintain privacy against the concerns of sexual partners, as well as the adolescent's interest in divulging HIV status to relatives, school staff, and friends.

Governor Culver’s 2008 Condition of the State Address, January 15, 2008

Speech by Governor Culver.