Establishment of an animal–bacterial association: Recruiting symbiotic vibrios from the environment

While most animal–bacterial symbioses are reestablished each successive generation, the mechanisms by which the host and its potential microbial partners ensure tissue colonization remain largely undescribed. We used the model association between the squid Euprymna scolopes and Vibrio fischeri to examine this process. This light organ symbiosis is initiated when V. fischeri cells present in the surrounding seawater enter pores on the surface of the nascent organ and colonize deep epithelia-lined crypts. We discovered that when newly hatched squid were experimentally exposed to natural seawater, the animals responded by secreting a viscous material from the pores of the organ. Animals maintained in filtered seawater produced no secretions unless Gram-negative bacteria, either living or dead, were reintroduced. The viscous material bound only lectins that are specific for either N-acetylneuraminic acid or N-acetylgalactosamine, suggesting that it was composed of a mucus-containing matrix. Complex ciliated fields on the surface of the organ produced water currents that focused the matrix into a mass that was tethered to, and suspended above, the light organ pores. When V. fischeri cells were introduced into the seawater surrounding the squid, the bacteria were drawn into its fluid-filled body cavity during ventilation and were captured in the matrix. After residing as an aggregate for several hours, the symbionts migrated into the pores and colonized the crypt epithelia. This mode of infection may be an example of a widespread strategy by which aquatic hosts increase the likelihood of successful colonization by rarely encountered symbionts.

Ablation of suprachiasmatic nucleus alters timing of hibernation in ground squirrels.

Hibernation patterns were monitored continuously for 2.5 years in female squirrels that were neurologically intact or in which the hypothalamic suprachiasmatic nucleus (SCN) was completely ablated (SCNx). The number of hibernation bouts in SCNx squirrels increased by 159%, total hibernation time increased by 58%, and periodic arousals from hibernation were 47% longer in SCNx than in control squirrels; the duration of individual torpor bouts was 2 days shorter and far more variable in SCNx than in control animals. Some SCNx squirrels cycled through bouts of torpor continuously for nearly 2 years. The SCN appears to be part of the mechanism that controls the duration of the hibernation season and the temporal structure of individual torpor bouts.

Zubiri y Ellacuría: fundamentos filosóficos para una teoría estructural y una praxeología crítica de las relaciones internacionales

La hipótesis de partida de esta tesis es que la teoría de las Relaciones Internacionales (RRII) se encuentra ante un problema de carácter filosófico que impide su adecuada fundamentación. El objeto mismo de la teoría de las RRII ha sido foco de numerosas disputas a lo largo y ancho de los debates con que la disciplina ha explicado sus diversos posicionamientos y enfoques. De igual manera, diferentes aproximaciones metodológicas han ido evolucionando al albur de los avances que la Filosofía de la Ciencia venía incorporando. Así, los diversos puntos de vista han tratado de adaptarse a las novedades de carácter epistemológico que incorporaba la Teoría de la Ciencia en forma de nuevos paradigmas y programas de investigación sin detenerse lo suficiente en revisar los postulados sustanciales sobre los que partió y se desarrollaron las distintas teorizaciones. Con demasiada frecuencia, los conceptos que guiaron los esfuerzos de la revisión de dichos postulados fueron utilizados de forma superficial, tratando con ello más bien de sustentar las teorías pre-configuradas que de realizar una aproximación reflexiva a la realidad sobre la que se pretendía teorizar, lo que ha evidenciado una insuficiencia conceptual de la teoría de las RRII para hacer frente a la realidad (Ashley 1984; Bohman 2009; Cox y Schechter 2002; Jackson 2008; Lapid 2003; Monteiro y Ruby 2009; Walker 1993)...

A Qualitative Study on Successful African American Marriages on How They Create and Repair Attachment Injuries Using Emotional Skillfulness.

The purpose of this phenomenological study was to describe the meanings that Ossie Davis and Ruby Dee Davis attribute to how they have adapted to their marriage and overcame conflict over the years. A purposive sample of this well-known African American married couple, who self-identified as being in a long-term, successful marriage, was used. The subjects of study were married for 56 years. An analysis using Colaizzi's (1978) method revealed 2 themes, with 13 and 2 subthemes respectively. The themes that emerged from the analysis of the formulated meanings were: (1) secrets to a successful marriage; and (2) sources of conflict in marriage. Secrets to a successful marriage included 13 subthemes: (a) egalitarian roles; (b) commitment; (c) forgiveness; (d) communication; (e) love; (f) honesty; (g) understanding the struggles of Black males and females; (h) friendship; (i) religion/ support from God; (j) compromise; (k) beliefs that marriage is a process; (l) emotional availability of spouse; and (m) feelings of security. In addition, the theme sources of conflict in marriage had two subthemes: (a) different decision making styles; and (b) experiences of abandonment. These findings provided insight from this couple's perspective on the secrets to a successful marriage and the ways in which they managed to make their marriage work, in light of the unique challenges that face African American marriages.

L’effet de l'interleukine-17 sur la survie et la glucocorticorésistance du neutrophile équin

Les glucocorticoïdes sont les médicaments les plus efficaces pour le contrôle de l'obstruction respiratoire chez les chevaux atteints du souffle, et de l'asthme humain. Toutefois, les neutrophiles persistent dans les voies respiratoires suite à ce traitement. Nous avons précédemment rapporté que les neutrophiles sanguins humains et équins sont sensibles à l'action des glucocorticoïdes. Comme elle contribue à l'insensibilité des cellules épithéliales pulmonaires humaines aux glucocorticoïdes, nous avons émis l'hypothèse que l'IL-17 a un effet similaire sur les neutrophiles et qu’elle contribue à leur persistance dans les voies respiratoires asthmatiques. Objectifs : Évaluer 1. L’expression des deux sous-unités du récepteur de l’IL-17 (l'IL-17RA/IL-17RC) chez les neutrophiles équins hautement purifiés. 2. Si l'IL-17 active directement les neutrophiles et si cette réponse est sensible à l'action des glucocorticoïdes. 3. L'effet de l'IL-17 sur la viabilité et l'apoptose des neutrophiles. Résultats: 1. Les neutrophiles expriment l’IL-17RA/IL-17RC aux niveaux translationnel et protéique. 2. L’IL-17 induit une activation sélective des neutrophiles (surrégulation de l’IL-8), qui n’est pas atténuée par dexaméthasone et 3. l’IL-17 augmente la viabilité des neutrophiles stimulés (LPS) par une diminution de l'apoptose. Nos résultats indiquent que l'IL-17 active directement le neutrophile équin, et que l’augmentation de l’IL-8 (puissant chimioatractant des neutrophiles) qui en résulte n’est pas contrôlée par la dexaméthasone. L'IL-17 pourrait aussi contribuer à la persistance de neutrophiles dans les voies respiratoires chez les chevaux atteints du souffle, en diminuant l'apoptose.

A report on the three-dee, three-phase 20-inch cyclotron /

Unclassified Physics Distribution.

P. F. C. Mary Brown, a WAC musical revue.

Libretto and production hints, condensed score, piano-conductor score and parts.

Treaty between the United States of America and the western bands of Shoshonee Indians.

"Concluded at Ruby valley, in the territory of Nevada."

Burma gazetteer.

Some gazetteers issued in two parts : [A], descriptive ; B, statistical tables.

Blue and Gray: Georgetown University and the Civil War.

Mode of access: Internet.

The Holy Thorn Reliquary, back

Metalwork, French, 14C; 1 ft. 1/64 in.x 5 29/32 in.x 2 3/4 in.; thorn, ruby, sapphire, gold, rock crystal, pearls, sapphires, enamel

The Holy Thorn Reliquary, open: detail

Metalwork, French, 14C; thorn, ruby, sapphire, gold, rock crystal, pearls, sapphires, enamel

The Holy Thorn Reliquary, front

Metalwork, French, 14C; 1 ft. 1/64 in.x 5 29/32 in.; thorn, ruby, sapphire, gold, rock crystal, pearls, sapphires, enamel

An inaugural address : delivered at Mercersburg, Pa. at the annual commecncement of Marshall College, September 26th, 1838 /

Mode of access: Internet.