THE EFFECT OF THE STM TIP ON SI(100) RECONSTRUCTED SURFACES

We present a theoretical study of the effects of the STM tip on the geometry of Si(100) reconstructed surfaces. The energy barrier to switching between different reconstructions is also discussed. We use a molecular dynamics method and self-consistent forces to simulate the time-dependent behaviour of the surface atoms. The molecular orbital calculations are performed at the CNDO level using a cluster model. Our results indicate significant differences for positively and negatively biased tips. The thermally induced rocking of surface dimers is inhibited by the application of a positive bias to the tip and it is promoted by a negative bias. These bias-dependent effects may offer a plausible explanation for the bias dependence of STM images of this surface

EFFECTS OF THE STM TIP ON ADSORBATE IMAGE

Scanning tunnelling microscopy provides atomic scale information about surface topography and electronic structure. However, the way the tip affects the STM image cannot always be neglected. We present a theoretical study of the effect of the non-uniform electric field of the tip on STM image of adsorbed molecules using Bardeen's approach. Self-consistent geometry optimization and wave-function calculations have been carried out within the CNDO approximation in a cluster model. Our results indicate significant effects. Thus for adsorbed CO on metal, the molecules reorient because of the tip, and the image is changed qualitatively as well as quantitatively. This may explain the lack of observation of CO at low coverage by STM. Our results also suggest the STM might be used for molecular modification

Control of Pain and Dyspnea in Patients with Oncologic Disease in Acute Care: Non-Pharmacological Intervention

Objective: To identify non-pharmacological strategies in the control of pain and dyspnea, in patient with oncological disease, in acute care. Methodology: Question in PI[C]O format was used and search at EBSCO (MEDLINE with Full TEXT; CINAHL, Plus with Full Text; British Nursing Index) retrospectively from 2009 to 2015. We included also guidelines by reference entities: Oncology Nursing Society (2011) National Comprehensive Cancer Network and Cancer Care Ontario, resulting in a total of 15 articles. Results: The gold standard for an adequate symptom control is a systematized assessment. Non-pharmacological measures: psycho-emotional support, hypnosis, counseling/training/ instruction, therapeutic adherence, music therapy, massage, relaxation techniques, telephone support, functional and respiratory reeducation increase health gains. Conclusion: The control of oncologic pain and dyspnea require a comprehensive and multimodal approach

Molecular basis of FIR-mediated c-myc transcriptional control

The far upstream element (FUSE) regulatory system promotes a peak in the concentration of c-Myc during cell cycle. First, the FBP transcriptional activator binds to the FUSE DNA element upstream of the c-myc promoter. Then, FBP recruits its specific repressor (FIR), which acts as an on/off transcriptional switch. Here we describe the molecular basis of FIR recruitment, showing that the tandem RNA recognition motifs of FIR provide a platform for independent FUSE DNA and FBP protein binding and explaining the structural basis of the reversibility of the FBP-FIR interaction. We also show that the physical coupling between FBP and FIR is modulated by a flexible linker positioned sequentially to the recruiting element. Our data explain how the FUSE system precisely regulates c-myc transcription and suggest that a small change in FBP-FIR affinity leads to a substantial effect on c-Myc concentration.MRC Grant-in-aid U11757455

(Micro)evolutionary changes and the evolutionary potential of bird migration

Seasonal migration is the yearly long-distance movement of individuals between their breeding and wintering grounds. Individuals from nearly every animal group exhibit this behavior, but probably the most iconic migration is carried out by birds, from the classic V-shape formation of geese on migration to the amazing nonstop long-distance flights undertaken by Arctic Terns Sterna paradisaea. In this chapter, we discuss how seasonal migration has shaped the field of evolution. First, this behavior is known to turn on and off quite rapidly, but controversy remains concerning where this behavior first evolved geographically and whether the ancestral state was sedentary or migratory (Fig. 7.1d, e). We review recent work using new analytical techniques to provide insight into this topic. Second, it is widely accepted that there is a large genetic basis to this trait, especially in groups like songbirds that migrate alone and at night precluding any opportunity for learning. Key hypotheses on this topic include shared genetic variation used by different populations to migrate and only few genes being involved in its control. We summarize recent work using new techniques for both phenotype and genotype characterization to evaluate and challenge these hypotheses. Finally, one topic that has received less attention is the role these differences in migratory phenotype could play in the process of speciation. Specifically, many populations breed next to one another but take drastically different routes on migration (Fig. 7.2). This difference could play an important role in reducing gene flow between populations, but our inability to track most birds on migration has so far precluded evaluations of this hypothesis. The advent of new tracking techniques means we can track many more birds with increasing accuracy on migration, and this work has provided important insight into migration's role in speciation that we will review here

Water from abandoned mines as a heat source: practical experiences of open- and closed-loop strategies, United Kingdom

Pilot heat pump systems have been installed at two former collieries in Yorkshire/Derbyshire, England, to extract heat from mine water. The installations represent three fundamental configurations of heat exchanger. At Caphouse Colliery, mine water is pumped through a heat exchanger coupled to a heat pump and then discharged to waste (an open-loop heat exchange system). The system performs with high thermal efficiency, but the drawbacks are: (1) it can only be operated when mine water is being actively pumped from the colliery shaft for the purposes of regional water-level management, and (2) the fact that the water is partially oxygenated means that iron oxyhydroxide precipitation occurs, necessitating regular removal of filters for cleaning. At Markham Colliery, near Bolsover, a small amount of mine water is pumped from depth in a flooded shaft, circulated through a heat exchanger coupled to a heat pump and then returned to the same mine shaft at a slightly different depth (a standing column arrangement). This system’s fundamental thermal efficiency is negatively impacted by the electrical power required to run the shaft submersible pump, but clogging issues are not significant. In the third system, at Caphouse, a heat exchanger is submerged in a mine water treatment pond (a closed-loop system). This can be run at any time, irrespective of mine pumping regime, and being a closed-loop system, is not susceptible to clogging issues

Small molecule sensitization to TRAIL is mediated via nuclear localization, phosphorylation and inhibition of chaperone activity of Hsp27

10.1038/cddis.2013.413Cell Death and Disease410

Monoubiquitination of syntaxin 3 leads to retrieval from the basolateral plasma membrane and facilitates cargo recruitment to exosomes

Syntaxin 3 (Stx3), a SNARE protein located and functioning at the apical plasma membrane of epithelial cells, is required for epithelial polarity. A fraction of Stx3 is localized to late endosomes/lysosomes, although how it traffics there and its function in these organelles is unknown. Here we report that Stx3 undergoes monoubiquitination in a conserved polybasic domain. Stx3 present at the basolateral—but not the apical—plasma membrane is rapidly endocytosed, targeted to endosomes, internalized into intraluminal vesicles (ILVs), and excreted in exosomes. A nonubiquitinatable mutant of Stx3 (Stx3-5R) fails to enter this pathway and leads to the inability of the apical exosomal cargo protein GPRC5B to enter the ILV/exosomal pathway. This suggests that ubiquitination of Stx3 leads to removal from the basolateral membrane to achieve apical polarity, that Stx3 plays a role in the recruitment of cargo to exosomes, and that the Stx3-5R mutant acts as a dominant-negative inhibitor. Human cytomegalovirus (HCMV) acquires its membrane in an intracellular compartment and we show that Stx3-5R strongly reduces the number of excreted infectious viral particles. Altogether these results suggest that Stx3 functions in the transport of specific proteins to apical exosomes and that HCMV exploits this pathway for virion excretion

Mineralization of sheep manure and its influence on lettuce production

Diversos resíduos orgânicos são utilizados na agricultura sem o adequado conhecimento da sua dinâmica de mineralização. Avaliou-se a mineralização de esterco de ovinos e sua influência na produção de alface. Utilizou-se o delineamento experimental de blocos ao acaso com três repetições. Foram utilizadas 25 t ha-1 como dose de esterco para cada um dos seguintes tratamentos: 1) esterco de ovinos que se alimentaram de feno de mandioca (PAM); 2) esterco de ovinos que se alimentaram de subproduto de ervilha (ERV); 3) esterco de ovinos que se alimentaram de feno de capim coast-cross (FCC); 4) esterco de ovinos que se alimentaram de subproduto de saccharina (SAC) e 5) solo sem aplicação de esterco (testemunha). Foi determinada semanalmente a respiração basal do solo, utilizada como indicador de mineralização da matéria orgânica. A massa fresca de alface foi avaliada como medida de produção. Os tratamentos ERV, FCC e SAC apresentaram ganhos de massa fresca na ordem de 68, 65 e 62% em relação à testemunha e de 43, 39 e 33% em relação ao PAM, respectivamente. A produção menor promovida pelo PAM, em relação às demais, pode ser explicada pela forma de mineralização da matéria orgânica que apresentou elevada respiração microbiana cinco dias após o transplantio, com acentuado declínio, nas medições subseqüentes, ao longo do ciclo da cultura. Os demais tratamentos apresentaram mineralização sincronizada com conseqüente aumento na produção de massa fresca. ____________________________________________________________________________________________________________ ABSTRACTSeveral organic wastes are used in agriculture with no precise knowledge about the mineralization dynamics of these materials. In this study the sheep manure mineralization and its influence on the lettuce production was evaluated. A randomized block design with three replications was used. Five treatments were studied using 25 t ha-1 as dose of manure: 1) sheep manure obtained from animals fed with cassava straw (PAM); 2) sheep manure obtained from animals fed with residue of pea crop (ERV); 3) sheep manure obtained from animals fed with Coast-Cross hay (FCC), 4) sheep manure obtained from animals fed with saccharin residue (SAC) and 5) soil without application of manure (control). Weekly the basal respiration was determined and used as an indicator of organic matter mineralization. Lettuce fresh mass was evaluated as a measure of production. Treatments ERV, FCC and SAC showed superior weight gains of 68, 65 and 62% compared to the control and 43, 39 and 33% compared to MAP, respectively. Lower production promoted by the MAP in relation to the other treatments can be explained by organic matter mineralization that showed a high microbial respiration five days after transplanting, with marked decline in subsequent measurements during the crop cycle. The other systems showed mineralization synchronized with the production increase of lettuce fresh mass

Search for direct pair production of the top squark in all-hadronic final states in proton-proton collisions at s√=8 TeV with the ATLAS detector

The results of a search for direct pair production of the scalar partner to the top quark using an integrated luminosity of 20.1fb−1 of proton–proton collision data at √s = 8 TeV recorded with the ATLAS detector at the LHC are reported. The top squark is assumed to decay via t˜→tχ˜01 or t˜→ bχ˜±1 →bW(∗)χ˜01 , where χ˜01 (χ˜±1 ) denotes the lightest neutralino (chargino) in supersymmetric models. The search targets a fully-hadronic final state in events with four or more jets and large missing transverse momentum. No significant excess over the Standard Model background prediction is observed, and exclusion limits are reported in terms of the top squark and neutralino masses and as a function of the branching fraction of t˜ → tχ˜01 . For a branching fraction of 100%, top squark masses in the range 270–645 GeV are excluded for χ˜01 masses below 30 GeV. For a branching fraction of 50% to either t˜ → tχ˜01 or t˜ → bχ˜±1 , and assuming the χ˜±1 mass to be twice the χ˜01 mass, top squark masses in the range 250–550 GeV are excluded for χ˜01 masses below 60 GeV