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We aimed to assess the potential of the characterization of association among weed species as a tool to understand weed occurrence for further supporting long-term management programs. After a sequence of summer crops, which included irrigated rice and sorghum, the experimental area was submitted to subsoiling, limestone was applied, and ryegrass was planted in the winter season. Six months later, an ACCase-inhibitor herbicide was used to select only non-grassweed species. Field survey was carried out on 100 quadrats with 0.5-m width that were randomly sampled. Plant species were organized in 2 × 2 contingency tables. The results of the calculated chi-squares were compared to the respective tables, and results were presented as a paired chi-square matrix. The species–area curve was also obtained. The relative occurrence of species was determined by its frequency and presented as a wordcloud. The network analysis was obtained by using the Fruchterman–Reingold layout. The hypothesis of plant association aiming survival in arable fields was validated. The methodology of plant association based on the chi-square test was applicable to arable fields, where weed species (usually competitor plant types) occur in clusters. From a practical point of view, preference should be given to herbicides that are efficient on most species within a given cluster.
To determine the ability of a novel responder mental health self-triage system to predict post-traumatic stress disorder (PTSD) in emergency medical responders after a disaster.
Participants in this study responded to Typhoon Haiyan, which struck the Philippines in November 2013. They completed the Psychological Simple Triage and Rapid Treatment (PsySTART) responder triage tool, the PTSD Checklist (PCL-5) and the Patient Health Questionnaire-8 (PHQ-8) shortly after responding to this disaster. The relationships between these 3 tools were compared to determine the association between different risk exposures while providing disaster medical care and subsequent levels of PTSD or depression.
The total number of PsySTART responder risk factors was closely related to PCL-5 scores ≥38, the threshold for clinical PTSD. Several of the PsySTART risk factors were predictive of clinical levels of PTSD as measured by the PCL-5 in this sample of deployed emergency medical responders.
The presence of a critical number and type of PsySTART responder self-triage risk factors predicted clinical levels of PTSD and subclinical depression in this sample of emergency medical workers. The ability to identify these disorders early can help categorize an at-risk subset for further timely “stepped care” interventions with the goals of both mitigating the long-term consequences and maximizing the return to resilience. (Disaster Med Public Health Preparedness. 2018;12:19–22)
We report on a target system supporting automated positioning of nano-targets with a precision resolution of
in three dimensions. It relies on a confocal distance sensor and a microscope. The system has been commissioned to position nanometer targets with 1 Hz repetition rate. Integrating our prototype into the table-top ATLAS 300 TW-laser system at the Laboratory for Extreme Photonics in Garching, we demonstrate the operation of a 0.5 Hz laser-driven proton source with a shot-to-shot variation of the maximum energy about 27% for a level of confidence of 0.95. The reason of laser shooting experiments operated at 0.5 Hz rather than 1 Hz is because the synchronization between the nano-foil target positioning system and the laser trigger needs to improve.
Experiments have shown that the ion energy obtained by laser–ion acceleration can be optimized by choosing either the appropriate pulse duration or the appropriate target thickness. We demonstrate that this behavior can be described either by the target normal sheath acceleration model of Schreiber et al. or by the radiation pressure acceleration model of Bulanov and coworkers. The starting point of our considerations is that the essential property of a laser system for ion acceleration is its pulse energy and not its intensity. Maybe surprisingly we show that higher ion energies can be reached with reduced intensities.
Surface-induced aromatic stabilization (SIAS), a recently proposed mechanism leading to a formation of charge-transfer (CT) states at organic/metal (O/M) interfaces [G. Heimel, et al., Nat. Chem.5, 187 (2013)], was investigated for an aromatic hydrocarbon, diindenoperylene (DIP), by means of synchrotron radiation-based ultraviolet photoelectron spectroscopy (UPS). By employing DIP and noble metal substrates (Ag and Cu), we confirmed the formation of CT states, indicating that an inclusion of a specific functional group with a hetero-atom within adsorbate molecules as suggested before is not necessarily required for the formation of CT states mediated by the SIAS. With a comparison of the mother and analogue molecules, perylene and PTCDA, we discuss the structural requirement for the realization of the SIAS.
We present near-infrared integral field observations of the super star cluster in the amorphous galaxy NGC1705. Data have been collected with SINFONI mounted on the VLT. Adaptive optics was used under good seeing conditions. Mosaics of the cluster and its immediate surrounding have been constructed. The cluster is not spatially resolved. Its radius is smaller than 2.85 ± 0.50pc. The K-band spectrum of the cluster is dominated by strong CO absorption bandheads. It is typical of a Galactic K 4–5 supergiant. Its age is estimated to be 12 ± 6Myr. The large error bar is rooted in the uncertainties of the input physics and ingredients of different evolutionary models.
The carnitine palmitoyltransferase (CPT) enzyme system facilitates the transport of long-chain fatty acids into mitochondria to provide substrates for β-oxidation. We performed an analysis including three coding SNP in the muscle isoform of the CPT1b gene (rs3213445, rs2269383 and rs470117) and one coding SNP in the CPT2 gene (rs1799821) to find associations with traits of the metabolic syndrome (MetS). Male participants (n 755) from the Metabolic Intervention Cohort Kiel were genotyped and phenotyped for features of the MetS. Participants underwent a glucose tolerance test and a postprandial assessment of metabolic variables after a standardised mixed meal. Carriers of the rare CPT1b 66V (rs3213445) allele had significantly higher γ-glutamyl transpeptidase (GGT), glutamic oxaloacetic transaminase (GOT) and glutamic pyruvate transaminase (GPT) activities (P< 0·0001, P= 0·03 and P= 0·048, respectively) and a higher fatty liver index (FLI, P= 0·026). Fasting and postprandial TAG (P= 0·007 and P= 0·009, respectively) and fasting glucose (P= 0·012) were significantly higher in 66V-allele carriers. The insulin sensitivity index determined after a glucose load was lower in those subjects (P= 0·005). Total cholesterol (P= 0·051) and LDL-cholesterol (P= 0·062) tended to be higher in 66V-allele carriers when compared with I66I homozygotes. Homozygosity of the rare K531E allele presented with lower GGT and GOT activities (P= 0·011 and P= 0·027, respectively). E531E homozygotes tended to have lower GPT and FLI (P= 0·078 and P= 0·052, respectively). CPT2 V368I (rs1799821) genotypic groups did not differ in the investigated anthropometric and metabolic parameters. The present results confirm the association of CPT1b coding polymorphisms with the MetS, with a deleterious effect of the CPT1b I66V and a protective impact of the CPT1b K531E SNP, whereas haplotype analysis indicates a relevance of the E531K polymorphism only.
We performed temperature-dependent studies on pentacene thin film transistors (TFTs) with and without encapsulation. The capping layer is realized either by a sputtering layer of aluminum oxide (AlOx.) or, alternatively, by a polymeric layer of poly-para-xylylene (PPX). A field-effect can be demonstrated for both capping materials up to temperatures of about 140 – 170 °C, which is about 50 °C above the desorption point of uncapped pentacene thin films on SiO2 substrates. Complementary studies by thermal desorption spectroscopy and temperature dependent x-ray diffraction show that the organic layer remains crystalline on the substrate far above the electrical breakdown temperature of the encapsulated device.
A photochromic effect is observed in WO3-based electrochromic devices with an ion-conducting polymer as electrolyte. Upon exposure to sun light, the electrochromic cells become blue. This is due to a change of color of the WO3 electrode. The photoeffect on this layer is due to a simultaneous insertion reaction (reduction) of the WO3 material and a photooxidation of water contained in the polymer. It is reversible and therefore not destructive for the complete device. The study of the transmittance and rest potential as a function of the time of exposure to light shows that a steady state is reached in c.a. 10 hours. The addition of U.V.-cut filters changes the reached steady-state, indicating that the photochromic effect is dependent upon the structure of the WO3 material.
even manganese dioxide (MD) forms including natural ramsdellite, β-MnO2 and samples with structures intermediate between these two types, have been analyzed interms of chemical and structural disorder. XRD and IR spectra show that natural ramsdellite contains groutellite, MnO1.5(OH)0.5. The OH absorption band in the 3400cm-1 region is sharp for groutellite, less intense on CMD spectrum, andsuperimposed to a broad and diffuse absorption ranging from 3600 to 2000cm-1 in most γ-MnO2's. The OH groups are associated with Mn+3 defects, while the broad and diffuse absorption band can be assigned to protons in empty MnO6 octahedra, and so related to instable manganese oxydation state between Mn3+ and Mn4+.
A potentiostatic study in IM and 7M KOH shows that the stoichiometric oxides, ramsdelliteand β-MnO2, are not reduced, while CMD and EMD are reversibly reduced by H+/-einsertion. In 7M KOH, a reversible reduction occurs for both CMDs and EMDs until -0.2 V, while a heterogeneous mechanism destroys the structure at lower potential (70% capacity loss after 3 redox cycles). Only ramsdellite and β-MnO2 can be cycled reversibly below -0.37 V, but the drained capacity is very low for β-MnO2.
The presence of Mn3+ and Mn4+ vacancies associated to structural disorderin synthetic MDs increases their reduction potential and completely modifies the chemicalproperties. This mixed valence state seems to be at the origin of the reduction properties by proton insertion in protonic electrolytes.
Molecular layer-by-layer build-up on a variety of substrates is demonstrated for doped polyaniline (PAn) alternating with non-ionic water soluble polymers. The adsorption is enabled by the strong interchain interactions with PAn, such as hydrogen bonding. Multilayer build-up has been demonstrated with four distinctly different non-ionic water soluble polymers: poly(vinyl pyrrolidone) (PVP), poly(vinyl alcohol) (PVA), poly(acrylamide) (PAAm), and poly(ethylene oxide) (PEO). Thus, non-ionic water soluble polymers containing a wide variety of functional groups such as amide, hydroxyl or ether groups can be used to successfully fabricate multilayer thin films with polyaniline. FTIR spectroscopy measurements show the PAn to be hydrogen bonded in these multilayer films. Conductivities for multilayer films are on the order of 1-4 S/cm for films doped with methane sulfonic acid. Conductivities on the order of 0.1 S/cm can be achieved for a single mixed layer self-assembled from a mixed solution of PAn/PVP or PAn/PAAm.
Spinel phases Li-Mn-C with Li/Mn ratios between 0.35 and 0.8 were synthesized. The relationships between composition, manganese valence, vacancy fraction and electrochemical capacity are described using a new composition-valence phase diagram. Electrochemical performances in lithium batteries are compared. The best materials showed constant capacit> 140 Ah/kg in the range 3.5/2 V in liquid electrolyte batteries up to 20 cycles, without the usual capacity drop observed in stoichiometric LiMn204.
The progress of dynamically disordered hopping (DDH) in modelling charge transport in polymer electrolytes is reviewed. The DDH model successfully describes many of the salient features of polymer electrolytes, most notably, the frequency and temperature dependence of the conductivity. Furthermore, analyses and simulations based on the DDH model provide rich mechanistic information. The general picture of charge transport that emerges from the DDH model is one in which two classes of charge carriers exist in thermal equilibrium:quasi-free and bound. The quasi-free carriers dominate the conductivity response and diffuse freely over short distances (≈1Å) with longer range diffusion requiringlocal segmental motions, renewal in the language of DDH, of the polymer solvent. The bound carriers, which are likely polymer solvated ion clusters, are immobile on the time-scale of renewal and contribute relatively little to the conductivity.
Several examples of dissolution-recrystallization processes at the nickel hydroxide electrode are reviewed. Some of them are very well known and have been studied for a few yearsin the case of Ni/Cd cells. The cycling of the ∝-type nickel hydroxide leads to the ∝→β transformation through dissolution of the a phase in the electrolyte (KOH) and recrystallization of the β phase from the solution. Further cycling of the resulting βex ∝phase causes an ageing effect which occursvia the solution (Oswald ripening). More recently, a strong ripening phenomenon has been observed by studying the behavior of nickel hydroxides cycling in Ni/H2 cells. By simulating the ageing of charged and discharged materials under hydrogen pressure inKOH media, it has been shown that in the absence of voltage, hydrogen cannot be responsible for the strong ripening effect. Synergetic effects between hydrogen and voltage have to be considered.
The 2D lithiated manganese oxide with Rancieite-type structure (lithium phyllomanganate), synthesized via a soft chemistry route (T≤60ºC) is hydrated at room temperature and can be dehydrated progressively by a thermal treatment. This compound and a series of samples obtained after annealing at different temperatures were characterized and studied for their electrochemical lithium intercalation properties. They are poorly crystallized, with however the advantage of a manganese oxidation state very close to 4, a mustto get high specific capacity. Their chemical characterization was achieved after gathering results obtained from complementary techniques such as AAS, redox titration, TGA and XPS measurements. Special care was taken for the chemical characterization of electrode compositions effectively used in the electrochemical cells.
Electrochemical lithium intercalation was systematically studied for the series of samples, when starting in charge or in discharge after assembly of the Li battery. The electrochemical behavior is discussed in relation with the manganese average oxidation state and the interlayer water content. Materials of the series showing the larger specific capacities were further examined on the application point of view, for their reversibility, cyclability and high rate capability upon Li intercalation.
This work shows that the anhydrous material which is obtained at 300ºC, with the composition Li0.42MnIII0.20MnIV0.8002.11, is a promising rechargeable layered manganese dioxide material.
The formation of lithium inserted W18O49 phases has been studied byelectrochemical methods. When lithium is inserted, several single phases LixW18O49 are observed in the range 0 ≤ x ≤ 40 between 3 and 1 V. Nevertheless the reaction is reversible only for x ≤ 22. Chemical reactions of W18O49 with different quantities of n-butyllithium have been carried out to isolate and characterize some of these phases. For Li17W18O49, this is ˜1:1 Li/W ratio, electron diffraction experiments clearly indicate that lithium produces a periodicity change, doubling the a, b and c cell parameters. On the other hand, when sodium is inserted in W18O49 two single phase regions NaxW18O49 are observed within the range 0 ≤ x ≤ 1.2 between 3 and 0.5 V.