Relative contributions of connexins 40 and 43 to atrial impulse propagation in synthetic strands of neonatal and fetal murine cardiomyocytes

Atrial tissue expresses both connexin 40 (Cx40) and 43 (Cx43) proteins. To assess the relative roles of Cx40 and Cx43 in atrial electrical propagation, we synthesized cultured strands of atrial myocytes derived from mice with genetic deficiency in Cx40 or Cx43 expression and measured propagation velocity (PV) by high-resolution optical mapping of voltage-sensitive dye fluorescence. The amount of Cx40 and/or Cx43 in gap junctions was measured by immunohistochemistry and total or sarcolemmal Cx43 or Cx40 protein by immunoblotting. Progressive genetic reduction in Cx43 expression decreased PV from 34+/-6 cm/sec in Cx43(+/+) to 30+/-8 cm/sec in Cx43(+/-) and 19+/-11 cm/sec in Cx43(-/-) cultures. Concomitantly, the cell area occupied by Cx40 immunosignal in gap junctions decreased from 2.0+/-1.6% in Cx43(+/+) to 1.7+/-0.5% in Cx43(+/-) and 1.0+/-0.2% in Cx43(-/-) strands. In contrast, progressive genetic reduction in Cx40 expression increased PV from 30+/-2 cm/sec in Cx40(+/+) to 40+/-7 cm/sec in Cx40(+/-) and 45+/-10 cm/sec in Cx40(-/-) cultures. Concomitantly, the cell area occupied by Cx43 immunosignal in gap junctions increased from 1.2+/-0.9% in Cx40(+/+) to 2.8+/-1.4% in Cx40(+/-) and 3.1+/-0.6% in Cx40(-/-) cultures. In accordance with the immunostaining results, immunoblots of the Triton X-100-insoluble fraction revealed an increase of Cx43 in gap junctions in extracts from Cx40-ablated atria, whereas total cellular Cx43 remained unchanged. Our results suggest that the relative abundance of Cx43 and Cx40 is an important determinant of atrial impulse propagation in neonatal hearts, whereby dominance of Cx40 decreases and dominance of Cx43 increases local propagation velocity.

Formation of heteromeric gap junction channels by connexins 40 and 43 in vascular smooth muscle cells

Connexin (Cx) 43 and Cx40 are coexpressed in several tissues, including cardiac atrial and ventricular myocytes and vascular smooth muscle. It has been shown that these Cxs form homomeric/homotypic channels with distinct permeability and gating properties but do not form functional homomeric/heterotypic channels. If these Cxs were to form heteromeric channels, they could display functional properties not well predicted by the homomeric forms. We assessed this possibility by using A7r5 cells, an embryonic rat aortic smooth muscle cell line that coexpresses Cxs 43 and 40. Connexons (hemichannels), which were isolated from these cells by density centrifugation and immunoprecipitated with antibody against Cx43, contained Cx40. Similarly, antibody against Cx40 coimmunoprecipitated Cx43 from the same connexon fraction but only Cx40 from Cx (monomer) fractions. These results indicate that heteromeric connexons are formed by these Cxs in the A7r5 cells. The gap junction channels formed in the A7r5 cells display many unitary conductances distinct from homomeric/homotypic Cx43 or Cx40 channels. Voltage-dependent gating parameters in the A7r5 cells are also quite variable compared with cells that express only Cx40 or Cx43. These data indicate that Cxs 43 and 40 form functional heteromeric channels with unique gating and conductance properties.

Factors that influence Information Systems decisions and outcomes: A summary of key themes from four case studies" (2006). ACIS 2006 Proceedings. Paper 43.

This paper reports a summary of key findings from an examination of Information Systems decision making in four organisations. The study focused on what factors influenced decision makers during the critical preimplementation phase of Information Systems projects when systems were evaluated, selected and acquired. Using data gathered from interviews and organisational documentation, a critical hermeneutic analysis was performed in order to build an understanding of how informational and contextual influences acted on decision makers. Eight broad themes of factors were identified as having influence on decision makers and outcomes.

Clergy Sexual Abuse Litigation: Survivors Seeking Justice By Jennifer M. Balboni (Boulder: First Forum Press, 2011, 180pp. £43.77)

Balboni identifies her interest as being the processes of official disclosure and the path taken to civil litigation by survivors of child sexual abuse by Roman Catholic Clergy. The empirical data, on which this work is based, come in the form of in-depth face-to-face interviews with 22 survivors of clergy sexual abuse who have pursued litigation and 13 of their advocates. Balboni provides a space for survivors’ accounts of the ‘why’ behind their decision making and the impact of civil litigation on their lives to be heard, discussed and contextualized with both clarity and sensitivity. She acknowledges the breadth and depth of survivor responses, and the perspectives of their legal advocates, employing defiance theory, symbolic interaction and other points of analysis, to capture the journey of survivors towards litigation and beyond. Balboni’s work is deeply poignant in its recognition of survivors’ voices, the complex transformative capacity of litigation, the effects of community forming amongst survivors and the complex nature of ‘empowerment’ obtained by survivors through civil litigation. Acknowledging that, for many survivors, litigation becomes a means of identity change and truth telling, Balboni admits that ‘these survivors helped me understand that litigation is more about voice than monetary settlement’ (p. 149). This work is not deeply analytical or theoretically rich but privileges the voices of survivors and their advocates with sufficient frameworks to contextualize and explain participants’ perspectives and experiences.

The antigen 43 structure reveals a molecular velcro-like mechanism of autotransporter-mediated bacterial clumping

Aggregation and biofilm formation are critical mechanisms for bacterial resistance to host immune factors and antibiotics. Autotransporter (AT) proteins, which represent the largest group of outer-membrane and secreted proteins in Gram-negative bacteria, contribute significantly to these phenotypes. Despite their abundance and role in bacterial pathogenesis, most AT proteins have not been structurally characterized, and there is a paucity of detailed information with regard to their mode of action. Here we report the structure–function relationships of Antigen 43 (Ag43a), a prototypic self-associating AT protein from uropathogenic Escherichia coli. The functional domain of Ag43a displays a twisted L-shaped β-helical structure firmly stabilized by a 3D hydrogen-bonded scaffold. Notably, the distinctive Ag43a L shape facilitates self-association and cell aggregation. Combining all our data, we define a molecular “Velcro-like” mechanism of AT-mediated bacterial clumping, which can be tailored to fit different bacterial lifestyles such as the formation of biofilms.

Effects of dietary phosphorus and calcium-to-phosphorus ratio on calcium and bone metabolism in healthy 20- to 43-year-old Finnish women

Dietary habits have changed during the past decades towards an increasing consumption of processed foods, which has notably increased not only total dietary phosphorus (P) intake, but also intake of P from phosphate additives. While the intake of calcium (Ca) in many Western countries remains below recommended levels (800 mg/d), the usual daily P intake in a typical Western diet exceeds by 2- to 3-fold the dietary guidelines (600 mg/d). The effects of high P intake in healthy humans have been investigated seldom. In this thesis healthy 20- to 43-year-old women were studied. In the first controlled study (n = 14), we examined the effects of P doses, and in a cross-sectional study (n = 147) the associations of habitual P intakes with Ca and bone metabolism. In this same cross-sectional study, we also investigated whether differences exist between dietary P originating from natural P sources and phosphate additives. The second controlled study (n = 12) investigated whether by increasing the Ca intake, the effects of a high P intake could be reduced. The associations of habitual dietary calcium-to-phosphorus ratios (Ca:P ratio) with Ca and bone metabolism were determined in a cross-sectional study design (n = 147). In the controlled study, the oral intake of P doses (495, 745, 1245 and 1995 mg/d) with a low Ca intake (250 mg/d) increased serum parathyroid hormone (S-PTH) concentration in a dose-dependent manner. In addition, the highest P dose decreased serum ionized calcium (S-iCa) concentration and bone formation and increased bone resorption. In the second controlled study with a dietary P intake of 1850 mg/d, by increasing the Ca intake from 480 mg/d to 1080 mg/d and then to 1680 mg/d, the S-PTH concentration decreased, the S-iCa concentration increased and bone resorption decreased dose-dependently. However, not even the highest Ca intake could counteract the effect of high dietary P on bone formation, as indicated by unchanged bone formation activity. In the cross-sectional studies, a higher habitual dietary P intake (>1650 mg/d) was associated with lower S-iCa and higher S-PTH concentrations. The consumption of phosphate additive-containing foods was associated with a higher S-PTH concentration. Moreover, habitual low dietary Ca:P ratios (≤0.50, molar ratio) were associated with higher S-PTH concentrations and 24-h urinary Ca excretions, suggesting that low dietary Ca:P ratios may interfere with homeostasis of Ca metabolism and increase bone resorption. In summary, excessive dietary P intake in healthy Finnish women seems to be detrimental to Ca and bone metabolism, especially when dietary Ca intake is low. The results indicate that by increasing dietary Ca intake to the recommended level, the negative effects of high P intake could be diminished, but not totally prevented. These findings imply that phosphate additives may be more harmful than natural P. Thus, reduction of an excessively high dietary P intake is also beneficial for healthy individuals.

Letras, 2000-2001, nº 42-43 (número completo)

Contenido: Garcilaso de la Vega: 1501?-2001 -- El concepto de "transformación" y sus aplicaciones al análisis de la poesía de Garcilaso / Sofía M. Carrizo Rueda – Algunas observaciones, a principios de un nuevo milenio, en torno a las comedias de Calderón de la Barca / Lilia E. Ferrario de Orduna – Palomeque, don Quijote, Cervantes: tres lectores de Cirongilio de Tracia de Bernardo de Vargas / Javier Roberto González – Cervantes: riesgo del vivir, azar y Providencia. Una lectura en clave bíblica y patrística / Teresa Herráiz de Tresca –La justicia divina o el orlo Amoris en el Amadis de Gaula / Silivia C. Lastra Paz -- Catálogo descriptivo de libros de caballerías castellanos, XIV. Otro Palmerín de Olivia recuperado: Sevilla, Jácome Cromberger, 1547 (Con algunas reflexiones sobre el arte de editar textos impresos) / José Manuel Lucía Megías – La defensa de la poesía en el Perú colonial: El Discurso en Loor de la Poesía / Graciela Maturo – Sobre la evolución de -nn-, -nw- y -w- interiores intervocálicos en la onomástica geográfica del Amadís de Gaula / Aquilino Suárez Pallasá – Reforma y Contrarreforma en las artes plásticas / Carmen Balzer – Tomás Moro y el Humanismo cristiano / Inés de Cassagne – Algunos poetas latinos del Humanismo / Raúl Lavalle – Reseñas bibliográficas

Estudio preliminar de las causas de pérdidas de viabilidad en la semilla de sorgo T-43 Sorghum bicolor (Linn) Moench

Este trabajo se realizó en dos investigativas La primera estuvo orientada en determinar si el tamaño de la semilla de sorgo T-43, tenía influencia en la viabilidad, lo cual se comprobó a nivel de campo y laboratorio, donde los porcentajes diferencias en ambos porcentajes. Cabe hacer mención que los datos obtenidos no son concluyentes, por carecer de repeticiones suficientes, pero si presentan tendencias en favor de la semilla clasificada con tamiz 10, el cual mostró los mayores porcentajes de germinación: de ello podemos deducir que la semilla para uso en la siembra se debe clasificar por tamaño. La segunda fase consisto en cosechar en tres épocas diferentes (tres diferentes humedades de semilla), los que se secaron al sol a 13 porciento de humedad, almacenándose en dos ambientes diferentes (cuarto frió, ambiente natural), los resultados no fueron concluyentes, ya que no se obtuvieron diferencias significativas en lo que se refiere a los ambientes de almacenamiento y los momentos de recolecta; por lo que la pérdida de viabilidad observada se atribuyen a otros factores no controlados en el curso de este trabajo. Por otra parte, la semilla se sorgo T-43, muestra su más alto porcentaje de germinación 90,80,y 85 a los 100 días , con rangos de temperatura y humedad relativa de 25-27ªC y 60-65 por ciento respectivamente, esto para los momentos de recolecta 27.70 y 19.37% de humedad.

Reproducción de Esquela de la Misa de Requiem conmemorativa del 43º Aniversario del fallecimiento del Fundador del Nacionalismo Vasco, Sabino de Arana y Goiri.

Fecha: 25-11-1944 (>1970 reproducción) / Unidad de instalación: Carpeta 25 - Expediente 23-6 / Nº de pág.: 1 (mecanografiada)

Day 3 at Networkshop 43 podcast transcript

Text transcription of interviews at day 3 of Networkshop 43

Front pages with contents of No. 43, 1986

Front cover. Contents. (PDF contains 2 pages)

Back pages of No. 43, 1986

Back cover. Map of Galápagos. Galapagos Penguin, Photo by G.T. Corley Smith.

The presence in the Marche of Sericostoma siculum McL. (Insecta-Trichoptera). Translation from: Boll.Soc.eustachiana 43(2), 47-50, 1950]

The caddisfly (Trichoptera) Sericostoma siculum was found in the Marche region in Italy. The article summarises biology and ecology of the caddisfly, focusing on the larvae stage.