A fast low-power optical memory based on coupled micro-ring lasers

The increasing speed of fibre-optic-based telecommunications has focused attention on high-speed optical processing of digital information. Complex optical processing requires a high-density, high-speed, low-power optical memory that can be integrated with planar semiconductor technology for buffering of decisions and telecommunication data. Recently, ring lasers with extremely small size and low operating power have been made, and we demonstrate here a memory element constructed by interconnecting these microscopic lasers. Our device occupies an area of 18 x 40 microm2 on an InP/InGaAsP photonic integrated circuit, and switches within 20 ps with 5.5 fJ optical switching energy. Simulations show that the element has the potential for much smaller dimensions and switching times. Large numbers of such memory elements can be densely integrated and interconnected on a photonic integrated circuit: fast digital optical information processing systems employing large-scale integration should now be viable.     

Body weight and organ sizes in warmth-adapted and in cold-adapted,hibernating golden hamsters

Zusammenfassung Von Dezember bis März wurden bei Goldhamstern im Winterschlaf und gleichzeitig bei wachen Kontrolltieren, die bei Zimmertemperatur gehalten wurden, Veränderungen von Organgewichten untersucht. Eine signifikante Zunahme des Gewichtes wurde bei Leber, Nieren, Herz, Pankreas, braunem Fettgewebe, Milz, Nebennieren und Nebennierenrinde der. Winterschläfer gefunden. Bei Körpergewicht, Haut, Testes, Femora und Nebennierenmark waren keine Unterschiede zwischen beiden Tiergruppen festzustellen.     

Occurrence of hibernation in the golden hamster,Mesocricetus auratus waterhouse

Résumé Une hypothèse est présentée pour expliquer la variabilité en durée de la période préléthargique au cours de l'année. La période préléthargique pouvait être approximée à trois mois. Dès novembre, le Hamster développe une prédisposition, résultant dans un raccourcissement de la période préléthargique. En février, la prédisposition pour le sommeil hivernal est au maximum, mais ensuite elle est perdue.     

Genome analysis of the platypus reveals unique signatures of evolution

We present a draft genome sequence of the platypus, Ornithorhynchus anatinus. This monotreme exhibits a fascinating combination of reptilian and mammalian characters. For example, platypuses have a coat of fur adapted to an aquatic lifestyle; platypus females lactate, yet lay eggs; and males are equipped with venom similar to that of reptiles. Analysis of the first monotreme genome aligned these features with genetic innovations. We find that reptile and platypus venom proteins have been co-opted independently from the same gene families; milk protein genes are conserved despite platypuses laying eggs; and immune gene family expansions are directly related to platypus biology. Expansions of protein, non-protein-coding RNA and microRNA families, as well as repeat elements, are identified. Sequencing of this genome now provides a valuable resource for deep mammalian comparative analyses, as well as for monotreme biology and conservation.     

The Light Green Cells ofLymnaea: A neuroendocrine model system for stimulus-induced expression of multiple peptide genes in a single cell type

We review recent experiments showing that the cerebral neuroendocrine Light Green Cells (LGCs) of the freshwater snail,Lymnaea stagnalis, express a family of distinct though related molluscan insulin-related peptide (MIP) genes. The LGCs are involved in the regulation of a wide range of interrelated life processes associated with growth, (energy) metabolism and reproduction. We consider the mechanism of generation of diversity among MIPs, and present evidence that conditions with distinct effects on growth, metabolism and reproduction also can induce distinct patterns of expression of the MIP and schistosomin genes. The stimulus-dependent expression of multiple neuropeptide genes enormously increases the adaptive potential of a peptidergic neuron. We suggest that this contributes significantly to the information-handling capacity of the brain.     

Immunological tests for LH and FSH in urine.

The addition of 100 g/l NaCl and 200 mg/l nitrofurantoin to 24-h urine samples destined for determination of LH and FSH with haemagglutination tests, proved to be an adequate preservative in comparison to chilling.     

The Light Green Cells of Lymnaea: a neuroendocrine model system for stimulus-induced expression of multiple peptide genes in a single cell type.

We review recent experiments showing that the cerebral neuroendocrine Light Green Cells (LGCs) of the freshwater snail, Lymnaea stagnalis, express a family of distinct though related molluscan insulin-related peptide (MIP) genes. The LGCs are involved in the regulation of a wide range of interrelated life processes associated with growth, (energy) metabolism and reproduction. We consider the mechanism of generation of diversity among MIPs, and present evidence that conditions with distinct effects on growth, metabolism and reproduction also can induce distinct patterns of expression of the MIP and schistosomin genes. The stimulus-dependent expression of multiple neuropeptide genes enormously increases the adaptive potential of a peptidergic neuron. We suggest that this contributes significantly to the information-handling capacity of the brain.