Description: Article describing the how the original vanadium sample was misanalysed and identified as chromium. Includes tourist information regarding Paris, France.

Description: In this article, the authors study a two-state symmetric noise, with a given waiting time distribution ψ(τ), and focus their attention on the connection between the four-time and two-time correlation functions. The transition of ψ(τ) from the exponential to the nonexponential condition yields the breakdown of the usual factorization condition of high-order correlation functions, as well as the birth of aging effects. The authors discuss the subtle connections between these two properties and establish the condition that the Liouville-like approach has to satisfy in order to produce a correct description of the resulting diffusion process.

Description: This article discusses using GIS technology to identify areas of tuberculosis transmission and incidence. Background: Currently in the U.S. it is recommended that tuberculosis screening and treatment programs be targeted at high-risk populations. While a strategy of targeted testing and treatment of persons most likely to develop tuberculosis is attractive, it is uncertain how best to accomplish this goal. In this study the authors seek to identify geographical areas where on-going tuberculosis transmission is occurring by linking Geographic Information Systems (GIS) technology with molecular surveillance. Methods: This cross-sectional analysis was performed on data collected on persons newly diagnosed with culture positive tuberculosis at the Tarrant County Health Department (TCHD) between January 1, 1993 and December 31, 2000. Clinical isolates were molecularly characterized using IS6 110-based RFLP analysis and spoligotyping methods to identify patients infected with the same strain. Residential addresses at the time of diagnosis of tuberculosis were geocoded and mapped according to strain characterization. Generalized estimating equations (GEE) analysis models were used to identify risk factors involved in clustering. Results: Evaluation of the spatial distribution of cases within zip-code boundaries identified distinct areas of geographical distribution of same strain disease. The authors identified these geographical areas as having increased ...

Description: This article discusses aging rejuvenation with fractional derivatives. Abstract: We discuss a dynamic procedure that makes a fractional derivatives emerge in the time asymptotic limit of non-Poisson processes. We find that two-state fluctuations, with an inverse power-law distribution of waiting times, finite first moment, and divergent second moment, namely, with the power index μ in the interval 2<μ<3, yield a generalized master equation equivalent to the sum of an ordinary Markov contribution and a fractional derivative term. We show that the order of the fractional derivative depends on the age of the process under study. If the system is infinitely old, the order of the fractional derivative, o, is given by o=3-μ. A brand new system is characterized by the degree o=μ-2. If the system is prepared at time -tₐ<0 and the observation begins at time t=0, we derive the following scenario. For times 0<t«tₐ the system is satisfactorily described by the fractional derivative with o=3-μ. Upon time increase the system undergoes a rejuvenation process that in the time limit t⪢tₐ yields o=μ-2. The intermediate time regime is probably incompatible with a picture based on fractional derivatives, or, at least, with a mono-order fractional derivative.

Description: This article discusses graft transmission of a floral stimulant derived from CONSTANS. Abstract: Photoperiod in plants is perceived by leaves and in many species influences the transition to reproductive growth through long-distance signaling. CONSTANS (CO) is implicated as a mediator between photoperiod perception and the transition to flowering in Arabidopsis. To test the role of CO in long-distance signaling, CO was expressed from a promoter specific to the companion cells of the smallest veins of mature leaves. This expression in tissues at the inception of the phloem translocation stream was sufficient to accelerate flowering at the apical meristem under noninductive (short-day) conditions. Grafts that conjoined the vegetative stems of plants with different flower-timing phenotypes demonstrated that minor-vein expression of CO is able to substitute for photoperiod in generating a mobile flowering signal. The authors' results suggest that a CO-derived signal(s), or possibly CO itself, fits the definition of the hypothetical flowering stimulant, florigen.