Crowd synchrony and quorum sensing in delay-coupled lasers

Crowd synchrony and quorum sensing arise when a large number of dynamical elements communicate with each other via a common information pool. Previous evidence in different fields, including chemistry, biology and civil engineering, has shown that this type of coupling leads to synchronization, when coupling is instantaneous and the number of coupled elements is large enough. Here we consider a situation in which the transmission of information between the system components and the coupling pool is not instantaneous. To that end, we model a system of semiconductor lasers optically coupled to a central laser with a delay. Our results show that, even though the lasers are non-identical due to their distinct optical frequencies, zero-lag synchronization arises. By changing a system parameter, we can switch between two different types of synchronization transition. The dependence of the transition with respect to the delay-coupling parameters is studied.Comment: 4 pages, 4 figure

ASSESSMENT OF URINARY HYDROXYPYRIDINIUM CROSS-LINKS MEASUREMENT IN OSTEOARTHRITIS

The aim of this study is to re-evaluate urinary collagen cross-links, previously proposed as markers of osteoarthritis (OA). The urinary excretion of collagen cross-links, pyridinoline (PYD) and deoxypyridinoline (DPD), was measured using high-performance liquid chromatography (HPLC) in 114 patients with OA, 19 patients with rheumatoid arthritis (RA) and 40 healthy subjects. An increase in PYD and DPD, expressed per millimole of creatinine, was confirmed in RA. However, PYD and DPD in patients with hip OA, knee OA and polyOA were similar, and did not differ from controls. In patients with radiographic end-stage OA, PYD and DPD were significantly higher than in patients with an early OA, but not significantly higher than in controls. The PYD/DPD ratio did not vary with the OA stage. Thus, urinary collagen cross-links are not elevated in OA, but could reflect bone sclerosis and/or erosion in late O

Cellular proliferation rate and insulin-like growth factor binding protein (IGFBP)-2 and IGFBP-3 and estradiol receptor alpha expression in the mammary gland of dairy heifers naturally infected with gastrointestinal nematodes during development

Mammary ductal morphogenesis during prepuberty occurs mainly in response to insulin-like growth factor-1 (IGF-1) and estradiol stimulation. Dairy heifers infected with gastrointestinal nematodes have reduced IGF-1 levels, accompanied by reduced growth rate, delayed puberty onset, and lower parenchyma-stroma relationship in their mammary glands. Immunohistochemical studies were undertaken to determine variations in cell division rate, IGF-1 system components, and estradiol receptors (ESR) during peripubertal development in the mammary glands of antiparasitic-treated and untreated Holstein heifers naturally infected with gastrointestinal nematodes. Mammary biopsies were taken at 20, 30, 40, and 70 wk of age. Proliferating cell nuclear antigen immunolabeling, evident in nuclei, tended to be higher in the parenchyma of the glands from treated heifers than in those from untreated. Insulin-like growth factor binding proteins (IGFBP) type 2 and type 3 immunolabeling was cytoplasmic and was evident in stroma and parenchyma. The IGFBP2-labeled area was lower in treated than in untreated heifers. In the treated group, a maximal expression of this protein was seen at 40 wk of age, whereas in the untreated group the labeling remained constant. No differences were observed for IGFBP3 between treatment groups or during development. Immunolabeling for α ESR (ESR1) was evident in parenchymal nuclei and was higher in treated than in untreated heifers. In the treated group, ESR1 peaked at 30 wk of age and then decreased. These results demonstrate that the parasite burden in young heifers negatively influence mammary gland development, affecting cell division rate and parameters related to estradiol and IGF-1 signaling in the gland.Escuela de Agricultura y Ganadería "María Cruz y Manuel L. Inchausti

Cellular proliferation rate and insulin-like growth factor binding protein (IGFBP)-2 and IGFBP-3 and estradiol receptor alpha expression in the mammary gland of dairy heifers naturally infected with gastrointestinal nematodes during development

Mammary ductal morphogenesis during prepuberty occurs mainly in response to insulin-like growth factor-1 (IGF-1) and estradiol stimulation. Dairy heifers infected with gastrointestinal nematodes have reduced IGF-1 levels, accompanied by reduced growth rate, delayed puberty onset, and lower parenchyma-stroma relationship in their mammary glands. Immunohistochemical studies were undertaken to determine variations in cell division rate, IGF-1 system components, and estradiol receptors (ESR) during peripubertal development in the mammary glands of antiparasitic-treated and untreated Holstein heifers naturally infected with gastrointestinal nematodes. Mammary biopsies were taken at 20, 30, 40, and 70 wk of age. Proliferating cell nuclear antigen immunolabeling, evident in nuclei, tended to be higher in the parenchyma of the glands from treated heifers than in those from untreated. Insulin-like growth factor binding proteins (IGFBP) type 2 and type 3 immunolabeling was cytoplasmic and was evident in stroma and parenchyma. The IGFBP2-labeled area was lower in treated than in untreated heifers. In the treated group, a maximal expression of this protein was seen at 40 wk of age, whereas in the untreated group the labeling remained constant. No differences were observed for IGFBP3 between treatment groups or during development. Immunolabeling for α ESR (ESR1) was evident in parenchymal nuclei and was higher in treated than in untreated heifers. In the treated group, ESR1 peaked at 30 wk of age and then decreased. These results demonstrate that the parasite burden in young heifers negatively influence mammary gland development, affecting cell division rate and parameters related to estradiol and IGF-1 signaling in the gland.Escuela de Agricultura y Ganadería "María Cruz y Manuel L. Inchausti

Aplicación de la inmunohistoquímica como herramienta de estudio complementaria para la identificación de componentes del parénquima y estroma mamario.

En la práctica docente, durante la observación microscópica de cortes histológicos coloreados con hematoxilina-eosina (H-E), no es posible la identificación y localización específica de diferentes componentes estructurales de los tejidos. La inmunohistoquímica (IHQ) es una herramienta que está disponible en numerosos laboratorios de histología y podría utilizarse para complementar las actividades docentes. Esta técnica, mediante la utilización de anticuerpos específicos, permite la localización de antígenos en células o tejidos in situ. El objetivo del trabajo fue aplicar la técnica de IHQ como herramienta de estudio complementaria a la coloración de H-E, para identificar componentes del parénquima y estroma de la glándula mamaria bovina. Se obtuvieron muestras de tejido mamario a partir de ubres sanas a los 14 días de involución. Se realizó IHQ indirecta utilizando anticuerpos primarios específicos para identificar: citoqueratinas (AE1/2), vimentina (V9), colágeno I, α-actina del músculo liso (SMA), células endoteliales (CD31), monocitos/macrófagos (CD14) y neutrófilos (CH138). Además, se utilizó anti PCNA para evaluar proliferación celular. El citoplasma de las células epiteliales que revisten alvéolos y conductos expresaron intensamente citoqueratinas AE1/2. Los fibroblastos del tejido conectivo (TC) expresaron marcación positiva con anti V9. En el TC interalveolar e interlobulillar se identificaron fibras de colágeno tipo I. Se observó reacción positiva intensa para CD31 en el citoplasma de las células endoteliales que revisten los vasos sanguíneos. Las células mioepiteliales que rodean alvéolos y conductos y las células musculares de los vasos sanguíneos reaccionaron intensamente con anti-SMA. Se lograron identificar y localizar monocito-macrófagos y neutrófilos. Se identificaron núcleos de células epiteliales y estromales en diferentes fases del ciclo celular. Se concluye que la aplicación de la IHQ en tejido mamario permitió identificar y localizar en forma específica diferentes componentes estructurales del estroma y parénquima, resultando de utilidad para complementar el estudio de la glándula mamaria bovina durante las actividades prácticas con los alumnos

Cellular proliferation rate and insulin-like growth factor binding protein (IGFBP)-2 and IGFBP-3 and estradiol receptor alpha expression in the mammary gland of dairy heifers naturally infected with gastrointestinal nematodes during development

Mammary ductal morphogenesis during prepuberty occurs mainly in response to insulin-like growth factor-1 (IGF-1) and estradiol stimulation. Dairy heifers infected with gastrointestinal nematodes have reduced IGF-1 levels, accompanied by reduced growth rate, delayed puberty onset, and lower parenchyma-stroma relationship in their mammary glands. Immunohistochemical studies were undertaken to determine variations in cell division rate, IGF-1 system components, and estradiol receptors (ESR) during peripubertal development in the mammary glands of antiparasitic-treated and untreated Holstein heifers naturally infected with gastrointestinal nematodes. Mammary biopsies were taken at 20, 30, 40, and 70 wk of age. Proliferating cell nuclear antigen immunolabeling, evident in nuclei, tended to be higher in the parenchyma of the glands from treated heifers than in those from untreated. Insulin-like growth factor binding proteins (IGFBP) type 2 and type 3 immunolabeling was cytoplasmic and was evident in stroma and parenchyma. The IGFBP2-labeled area was lower in treated than in untreated heifers. In the treated group, a maximal expression of this protein was seen at 40 wk of age, whereas in the untreated group the labeling remained constant. No differences were observed for IGFBP3 between treatment groups or during development. Immunolabeling for α ESR (ESR1) was evident in parenchymal nuclei and was higher in treated than in untreated heifers. In the treated group, ESR1 peaked at 30 wk of age and then decreased. These results demonstrate that the parasite burden in young heifers negatively influence mammary gland development, affecting cell division rate and parameters related to estradiol and IGF-1 signaling in the gland.Escuela de Agricultura y Ganadería "María Cruz y Manuel L. Inchausti

RFLP diversity and relationships among traditional European maize populations

DOI:10.1007/s00122-002-0903-7International audienc