A computer program for the geographic distribution of fluvial mollusks of medical interest in Cuba

The need to know the distribution of mollusks considered to play an important medical role in Cuba through a geographic representation motivated us to develop a software capable of acting as a system for the retrieval of geographic information in which the requested data would be presented in maps. The system has been called DMIM and it is a useful tool for malacological studies, and assessment and planning of programs for the control of intermediate host mollusks, as well as for teaching purposes.     

The Chloroplast of Chlamydomonas reinhardtii as a Testbed for Engineering Nitrogen Fixation into Plants

Eukaryotic organisms such as plants are unable to utilise nitrogen gas (N₂) directly as a source of this essential element and are dependent either on its biological conversion to ammonium by diazotrophic prokaryotes, or its supply as chemically synthesised nitrate fertiliser. The idea of genetically engineering crops with the capacity to fix N₂ by introduction of the bacterial nitrogenase enzyme has long been discussed. However, the expression of an active nitrogenase must overcome several major challenges: the coordinated expression of multiple genes to assemble an enzyme complex containing several different metal cluster co-factors; the supply of sufficient ATP and reductant to the enzyme; the enzyme’s sensitivity to oxygen; and the intracellular accumulation of ammonium. The chloroplast of plant cells represents an attractive location for nitrogenase expression, but engineering the organelle’s genome is not yet feasible in most crop species. However, the unicellular green alga Chlamydomonas reinhardtii represents a simple model for photosynthetic eukaryotes with a genetically tractable chloroplast. In this review, we discuss the main advantages, and limitations, of this microalga as a testbed for producing such a complex multi-subunit enzyme. Furthermore, we suggest that a minimal set of six transgenes are necessary for chloroplast-localised synthesis of an ‘Fe-only’ nitrogenase, and from this set we demonstrate the stable expression and accumulation of the homocitrate synthase, NifV, under aerobic conditions. Arguably, further studies in C. reinhardtii aimed at testing expression and function of the full gene set would provide the groundwork for a concerted future effort to create nitrogen-fixing crops.     

Effect of high-dose nicotine patch on the characteristics of lapse episodes.

Objective: Nicotine patch improves treatment outcomes, but lapses are still common. To understand the process of relapse on patch, we investigated differences in the antecedents (withdrawal, setting, triggers) of lapse episodes experienced on high-dose (35 mg) nicotine patches versus placebo. Design: Participants were smokers who lapsed during a randomized, double-blind trial of active patches (n = 100) versus placebo (n = 85). Participants used electronic diaries to monitor their smoking, affect, and activities in real time for 5 weeks during their cessation attempt. Results: We analyzed 490 lapse episodes (active: 266; placebo: 224). Lapses on nicotine patch were characterized by significantly lower positive affect and higher negative affect than placebo lapses. Participants treated with high-dose patch were also significantly more likely to lapse in situations involving little or no craving. Situational antecedents of lapses on patch resembled those on placebo. Conclusion: The results suggest that treatment with patch may set a higher threshold for affective stimuli to provoke lapses, but does not change the proximal cues that trigger lapses. This suggests that behavioral relapse-prevention strategies developed for unmedicated smokers should also apply to those treated with nicotine patch. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

N,7,7‐Tricyanoquinomethanimine (TCQMI) Based Organic Magnetic Materials

The synthesis and characterization of a new family of magnetic materials based on the electron accepting cyanocarbon N,7,7‐tricyanoquinomethanimine, TCQMI, its radical anion [TCQMI], and its σ‐dimer, σ‐[TCQMI]₂^2?, are reported. [Fe^IIICp*₂][TCQMI] (where Cp* is pentamethylcyclopentadienide) forms parallel chains of alternating [TCQMI]^?? and [FeCp*₂]^?+ and magnetically orders at 3.4 K as a weak ferromagnet. M[TCQMI]₂?zCH₂Cl₂ (M = V, Fe) are amorphous solids with [TCQMI]^?? coordinated to metal centers through the nitrile groups. The Fe compound magnetically orders as a weak ferromagnet at ≈4 K, whereas the V compound shows no evidence of magnetic ordering. {[Mn^IIITPP]⁺}₂[TCQMI]₂^2? (TPP = tetraphenylporphyrin) results from the reaction of TCQMI with Mn^IITPP(py) due to the formation of the [TCQMI]₂^2? σ‐dimer in situ, and is a weak ferromagnet below 3.7 K. The lack of magnetic ordering in V[TCQMI]₂?zCH₂Cl₂ is not currently understood, and is in strong contrast to V[TCNE]₂?zCH₂Cl₂, which magnetically orders above room temperature.     

Tobacco withdrawal in women and menstrual cycle phase.

Because negative mood is a characteristic of both tobacco withdrawal and menstrual discomfort, withdrawal may vary by menstrual cycle phase. Tobacco withdrawal, mood, and menstrual discomfort were assessed in premenopausal women who quit smoking during either the follicular (Days 1–14 postmenstrual onset; n?=?41) or luteal (Day 15 or longer postmenstrual onset; n?=?37) phase of the menstrual cycle and maintained biochemically verified smoking abstinence during the postquit week. Women quitting during the luteal phase reported significantly greater increases in tobacco withdrawal and self-reported depressive symptoms than women quitting during the follicular phase. These results indicate that selecting a quit-smoking day early in the follicular phase may attenuate withdrawal and negative affect in premenopausal female smokers. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Doppelwaagebalkenbrücke – Vorschlag für einen innovativen Klappbrückentyp

Double balance beam bridge – Prposal of a new type of bascule bridge. So far, balance beam bridges have been build as single span bridge. Due to the articulation of the balance beam, this system takes the permanent loads only. If, instead, the rotation of the balance beam is blocked by a second bearing, the staying system participates also in taking the live loads. This allows to build balance beam bridges with two flaps and thereby double their span range.     

Proportional Sampling in Life Length Studies

In studying electron tube life, measuring the life of a tube in service in a system whose age is T amounts to lifelength proportional sampling. The problems of estimating mean life from such data are considered for finite T and for “equilibrium” (large T). Several variations on the straight-forward life-biased sampling plan which are avilable to the experimenter are mentioned and conditions are found under which these other sampling schemes would be better than the life-proportional scheme. Particular attention is paid to the gamma and Weibull families of distributions. Other applications of these results are discussed.     

Indoor levels of volatile organic compounds at Florentine museum environments in Italy

Indoor Air Quality monitoring in cultural institutions is of particular concern to protect these places and the cultural heritage content. An indoor monitoring campaign was performed in three museums in Florence (Italy) to determine the occurrence and levels of volatile organic compounds (VOCs). VOCs of interest included BTEX (benzene, toluene, ethylbenzene, xylenes), terpenes, aldehydes, organic acids, and cyclic volatile methyl siloxanes (cVMS). The most abundant VOCs in all samples analyzed were BTEX, which were strictly related to the traffic source, followed by siloxanes and terpenes. Among BTEX, toluene was always the most abundant followed by xylenes, ethylbenzene, and benzene. cVMS in exhibition rooms with the presence of visitors showed higher values compared to samples collected when the museums were closed. Terpenes showed not only the influence of vegetation-biogenic sources surrounding a museum but could also be related to the wood used for the construction of showcases and furniture and the use of cleaning products. Data obtained also showed the presence of organic acids and aldehydes whose source can be traced back to exhibits themselves and wood-based furniture. Assessing the levels of organic acids in museums is important because, over time, it can cause deterioration of the artifacts.     

Signal and noise transfer in spatiotemporal quantum-based imaging systems

Fourier-based transfer theory is extended into the temporal domain to describe both spatial and temporal noise processes in quantum-based medical imaging systems. Lag is represented as a temporal scatter in which the release of image quanta is delayed according to a probability density function. Expressions describing transfer of the spatiotemporal Wiener noise power spectrum through quantum gain and scatter processes are derived. Lag introduces noise correlations in the temporal domain in proportion to the correlated noise component only. The effect of lag is therefore dependent on both spatial and temporal physical processes. A simple model of a fluoroscopic system shows that image noise is reduced by a factor that is similar to Wagner's information bandwidth integral, which depends on the temporal modulation transfer function.