Novelty,coherence, and Mendeleev’s periodic table

Predictivism is the view that successful predictions of “novel” evidence carry more confirmational weight than accommodations of already known evidence. Novelty, in this context, has traditionally been conceived of as temporal novelty. However temporal predictivism has been criticized for lacking a rationale: why should the time order of theory and evidence matter? Instead, it has been proposed, novelty should be construed in terms of use-novelty, according to which evidence is novel if it was not used in the construction of a theory. Only if evidence is use-novel can it fully support the theory entailing it. As I point out in this paper, the writings of the most influential proponent of use-novelty contain a weaker and a stronger version of use-novelty. However both versions, I argue, are problematic. With regard to the appraisal of Mendeleev’ periodic table, the most contentious historical case in the predictivism debate, I argue that temporal predictivism is indeed supported, although in ways not previously appreciated. On the basis of this case, I argue for a form of so-called symptomatic predictivism according to which temporally novel predictions carry more confirmational weight only insofar as they reveal the theory’s presumed coherence of facts as real.     

Physiology: does gut hormone PYY3-36 decrease food intake in rodents?

Batterham et al. report that the gut peptide hormone PYY3-36 decreases food intake and body-weight gain in rodents, a discovery that has been heralded as potentially offering a new therapy for obesity. However, we have been unable to replicate their results. Although the reasons for this discrepancy remain undetermined, an effective anti-obesity drug ultimately must produce its effects across a range of situations. The fact that the findings of Batterham et al. cannot easily be replicated calls into question the potential value of an anti-obesity approach that is based on administration of PYY3-36.     

Purification of 2-deoxy-2-dansylamido-D-glucose by affinity chromatography on a lectin-loaded agarose column

Summary A method is demonstrated to purify 2-substituted derivatives of glucose and sterically related sugars by affinity chromatography on Con A-sepharose. The method seems to be of rather general applicability.     

Spontaneous mutants ofStaphylococcus aureus PS 80

Zusammenfassung Eine Reihe von Mutanten mit verschiedenen Phenotypen wurde nach einfähriger Lagerung desStaphylococcus aureus PS 80 isoliert. Sie untersucheiden sich in mehreren Merkmalen vom Wildtyp. Aus der Tetracyklin-empfindlichen population der PS-80-Zellen wurden Tetracyklin-resistente Mutanten selektiert, die gleichzeitig resistent gegen Streptomycin, Chloramfenikol, Erythromycin, Cephaloridin, Lincomycin und Spiramycin sind.     

Comparison of the effects of β-palmitoyl lysolecithin and cardiac glycosides in two mammalian tissues

Zusammenfassung 1957 sind vonHajdu et al. Versuche veröffentlicht worden, wonach sich aus verschiedenen Geweben eine Substanz mit Herzglykosid-ähnlicher Wirkung auf Kaltblüterherzen extrahieren lässt, welche als -Palmitoyl-lysolecithin interpretiert wurde. In unseren Versuchen wurde aus Hefe Dipalmitoleyl-lecithin isoliert und daraus durch enzymatische Abspaltung der -ständigen Fettsäure und anschliessende katalytische Hydrierung reines, hämolytisch wirksames -Palmitoyl-lysolecithin hergestellt. Diese Verbindung zeigte jedoch keine den Effekten der Herzglykoside verwandte Wirkung am isolierten Meerschweinchenventrikel sowie an menschlichen Erythrocyten.     

Tunable ion-photon entanglement in an optical cavity

Proposed quantum networks require both a quantum interface between light and matter and the coherent control of quantum states. A quantum interface can be realized by entangling the state of a single photon with the state of an atomic or solid-state quantum memory, as demonstrated in recent experiments with trapped ions, neutral atoms, atomic ensembles and nitrogen-vacancy spins. The entangling interaction couples an initial quantum memory state to two possible light-matter states, and the atomic level structure of the memory determines the available coupling paths. In previous work, the transition parameters of these paths determined the phase and amplitude of the final entangled state, unless the memory was initially prepared in a superposition state (a step that requires coherent control). Here we report fully tunable entanglement between a single (40)Ca(+) ion and the polarization state of a single photon within an optical resonator. Our method, based on a bichromatic, cavity-mediated Raman transition, allows us to select two coupling paths and adjust their relative phase and amplitude. The cavity setting enables intrinsically deterministic, high-fidelity generation of any two-qubit entangled state. This approach is applicable to a broad range of candidate systems and thus is a promising method for distributing information within quantum networks.     

Role of Nef in primate lentiviral immunopathogenesis

More than a decade ago it was established that intact nef genes are critical for efficient viral persistence and greatly accelerate disease progression in SIVmac-infected rhesus macaques and in HIV-1-infected humans. Subsequent studies established a striking number of Nef functions that evidently contribute to the maintenance of high viral loads associated with the development of immunodeficiency in the 'evolutionary-recent' human and the experimental macaque hosts. Recent data show that many Nef activities are conserved across different lineages of HIV and SIV. However, some differences also exist. For example, Nef alleles from most SIVs that do not cause disease in their natural monkey hosts, but not those of HIV-1 and its simian precursors, down-modulate TCR-CD3 to suppress T cell activation and programmed death. This evolutionary loss of a specific Nef function may contribute to the high virulence of HIV-1 in humans.