CCCTC-binding factor: to loop or to bridge

Eukaryotic genomes have complex spatial organization in the nucleus. The factors and the mechanisms involved in this organization remain an enigma. Among the many proteins implicated in such a role, the ubiquitous Zn-finger protein CTCF stands out. Here we summarize the evidence placing CTCF in the enviable position of a master organizer of the genome. CTCF can form loops in cis, and can bridge sequences located on different chromosomes in trans. The thousands of CTCF binding sites, identified in recent genome-wide localization studies, and their distribution along the genome further support a crucial role of CTCF as a chromatin organizer. Received 10 October 2008; received after revision 11 December 2008; accepted 16 December 2008     

Fine ways to fail to secure local realism

Since he proved his theorem in 1982, Fine has been challenging the traditional interpretation of the experimental violation of the Bell Inequalities (BI). A natural interpretation of Fine's theorem is that it provides us with an alternative set of assumptions on which to place blame for the failure of the BI, and opens to a new interpretation of the violation of the BI. Fine has a stronger interpretation for his theorem. He claims that his result undermines the traditional interpretation in terms of local realism. The aim of this paper is to understand and to assess Fine's claim. We distinguish three different strategies that Fine uses in order to support his view. We show that none of these strategies is successful. Fine fails to prove that local realism is not at stake in the violation of the BI by quantum phenomena.     

An attempt to produce antibodies to oxytocin and vasopressin

Zusammenfassung Mit einem Oxytocin-Albumin-Konjugat bzw. mit einem Lysin-Vasopressin-Albumin-Konjugat konnten bei Kaninchen spezifische Antikörper hervorgerufen werden. Die gegen Oxytocin-Albumin-Konjugat gerichteten Antikörper scheinen auch einen gewissen inaktivierenden Effekt auf genuines Oxytocin zu haben.     

Metal binding to myosin and to myosin DTNB-light chain

Summary The effects of various divalent cations, Ca²⁺, Mg²⁺ and Mn²⁺ on the intrinsic fluorescence of heavy meromyosin (HMM) and myosin 5,5-dithio-bis-(2-nitrobenzoate) DTNB-light chain of rabbit striated muscle, are compared. At pH 6.4, the fluorescence change induced by the metal ions is present only in the isolated light chain and disappears in HMM, thus indicating an interaction between the heavy and light chains with respect to the binding of the metal ions. Whereas Mg²⁺ binds more strongly than Ca²⁺ to myosin, this order is reversed in the case of the DTNB-light chain.     

Mesencephalic reticular responses to natural and to repeated sensory stimuli

Résumé L'activité des neurones de la formation réticulaire mésencéphalique du chat est modifiée par l'effet de stimuli physiologiques, quelque fois très complexes: la convergence hétéro-sensorielle est très évidente et les champs récepteurs ont différentes étendues et distributions. Soumises à de hautes fréquences de stimulation, les cellules présentent une réactivité limitée. Au fur et à mesure que la stimulation est répétée, les réponses diminuent et, finalement, disparaissent; cette diminution de réactivité est souvent spécifique de la stimulation utilisée.     

How to think about analogical inferences: A reply to Norton

In this paper, I raise some worries with John D. Norton's application of his material theory of induction to the study of analogical inferences. Skeptical that these worries can be properly addressed, I propose a principle to guide the philosophical research on analogical inferences and argue for its usefulness.     

Feeding response of adultTribolium to carbohydrates in relation to their utilisation

Zusammenfassung Die Fütterungsreaktionen beim erwachsenenTribolium castaneum (Herbst.) zeigen, dass keine der verschiedenen Kohlenhydrate das Fressen besonders anregt. Der Nährwert dieser Kohlenhydrate nimmt in folgender Reihenfolge ab: Stärke und Maltose; Glukose, Melibiose und Milchzucker; Rohrzucker, Fruchtzucker, Melezitose, Raffinose und Cellobiose.     

Block to pseudopregnancy in mice caused by exposure to male urine

Zusammenfassung Mäuseweibchen, die durch Paarung mit vasektomierten Männchen scheinträchtig gemacht worden waren, wurden dem Urin von Männchen eines anderen Stammes ausgesetzt. Dadurch wurde die Pseudogravidität unterbrochen. Diese Beobachtung gleicht der Unterbrechung der Trächtigkeit frisch begatteter Weibchen durch den Urin fremdstämmiger Männchen und bestätigt auch die Beschleunigung des Eintritts des Östrus durch die Gegenwart der Männchen.