Fruit Rot of Durian Caused by Phytophthora palmivora

A severe fruit rot of durzan fruits in Bentong and Raub in Pahang; Dengkil in Selangor; Muar and Kluang in Johore was found to be caused by a Phytophthora sp. Besides fruits, isolates of the pathogen were also capable of infecting roots, stem and leaves of durian. The isolates were identified as Phytophthora palmivora, cross-inducing (heterothallic) and of the A 1 mating type, producing spores when paired with a standard A2 mating type of P. palmivora and another A2 isolate from cocoa but not with an A 1 mating type of P.parasitica

Conflicts in Knowledge Management: Vistiting the Hidden Partner

As knowledge gains a reputation for being a critical resource in the information-intensive economy, organizations have doubled their efforts in trying to extract value from knowledge management policies. One particular aspect of knowledge management, which has gone unnoticed in academic research, is the presence of conflicts in knowledge activities. By adopting a conflict perspective of knowledge activities, this study arrives at a two-dimensional framework that defines knowledge conflicts in terms of its type and nature. Central to this paper is the fundamental idea that conflicts form an integral part of knowledge management and depending on how they are managed; conflicts may be formidable partners or dangerous adversaries in the corporate quest for knowledge-derived competitiveness

Alternative explanation for the relaxor ferroelectric behavior in FeTiNbO6 rutile ceramics: The influence of electrode contacts

The radio-frequency permittivity-temperature profiles of acceptor-donor codoped TiO2-based rutiles commonly produce higher than expected values (>103 at 300 K) often with conflicting interpretations. A combination of dielectric spectroscopy (DS) and impedance spectroscopy (IS) with different electrode materials is used to reinvestigate the electrical properties of Fe3+-Nb5+-doped rutile in the form of FeTiNbO6 ceramics that show permittivity-temperature characteristics that are consistent with relaxor ferroelectrics (RFE). IS results reveal semiconducting grains with an activation energy of ∼0.16eV, and relative permittivity of similar magnitude and temperature dependence to undoped TiO2(<250). Reducing the work function of the electrode material by replacing Au with InGa has a dramatic effect on the IS and DS data. We propose the apparent RFE behavior observed by DS and previously attributed to the formation of nanoclustering of the cations is an extrinsic effect primarily associated with the development of Schottky barriers between the semiconducting ceramics and Au contacts

The new chiral ligand 3-ethoxy-4-E(1R,2SS)-(2-hydroxy-1,2-diphenylethyl)amino -3-cyclobutene-1 ,2-dione

The asymmetric unit of C20H19NO4 contains two molecules with slightly different conformations, In the crystal,the molecules are linked by O-H ... O and N-H ... O hydrogen bonds [O ... O 2.764 (3) and 2.811 (3) Angstrom; N ... O 2.907 (3) and 3.968 (3) Angstrom] to form a two-dimensional network

The effect of layer number and substrate on the stability of graphene under MeV proton beam irradiation

The use of graphene electronics in space will depend on the radiation hardness of graphene. The damage threshold of graphene samples, subjected to 2 MeV proton irradiation, was found to increase with layer number and also when the graphene layer was supported by a substrate. The thermal properties of graphene as a function of the number of layers or as influenced by the substrate argue against a thermal model for the production of damage by the ion beam. We propose a model of intense electronically-stimulated surface desorption of the atoms as the most likely process for this damage mechanism.Comment: 20 pages, 5 figure

Kondo effect in coupled quantum dots: a Non-crossing approximation study

The out-of-equilibrium transport properties of a double quantum dot system in the Kondo regime are studied theoretically by means of a two-impurity Anderson Hamiltonian with inter-impurity hopping. The Hamiltonian, formulated in slave-boson language, is solved by means of a generalization of the non-crossing approximation (NCA) to the present problem. We provide benchmark calculations of the predictions of the NCA for the linear and nonlinear transport properties of coupled quantum dots in the Kondo regime. We give a series of predictions that can be observed experimentally in linear and nonlinear transport measurements through coupled quantum dots. Importantly, it is demonstrated that measurements of the differential conductance ${\cal G}=dI/dV$, for the appropriate values of voltages and inter-dot tunneling couplings, can give a direct observation of the coherent superposition between the many-body Kondo states of each dot. This coherence can be also detected in the linear transport through the system: the curve linear conductance vs temperature is non-monotonic, with a maximum at a temperature $T^*$ characterizing quantum coherence between both Kondo states.Comment: 20 pages, 17 figure

Simulation of dimensionality effects in thermal transport

The discovery of nanostructures and the development of growth and fabrication techniques of one- and two-dimensional materials provide the possibility to probe experimentally heat transport in low-dimensional systems. Nevertheless measuring the thermal conductivity of these systems is extremely challenging and subject to large uncertainties, thus hindering the chance for a direct comparison between experiments and statistical physics models. Atomistic simulations of realistic nanostructures provide the ideal bridge between abstract models and experiments. After briefly introducing the state of the art of heat transport measurement in nanostructures, and numerical techniques to simulate realistic systems at atomistic level, we review the contribution of lattice dynamics and molecular dynamics simulation to understanding nanoscale thermal transport in systems with reduced dimensionality. We focus on the effect of dimensionality in determining the phononic properties of carbon and semiconducting nanostructures, specifically considering the cases of carbon nanotubes, graphene and of silicon nanowires and ultra-thin membranes, underlying analogies and differences with abstract lattice models.Comment: 30 pages, 21 figures. Review paper, to appear in the Springer Lecture Notes in Physics volume "Thermal transport in low dimensions: from statistical physics to nanoscale heat transfer" (S. Lepri ed.

Reversal of cardiac damage in patients with symptomatic severe aortic stenosis following transcatheter aortic valve implantation: An echocardiographic study

Background: Severe aortic stenosis (AS) results in cardiac damages, such as left ventricular hypertrophy, left atrial enlargement, pulmonary pressure elevation and in advanced stage, right ventricular damage. Généreux and colleagues proposed a staging classification based on these extra-valvular damages in 2017, with increasing stage representing more cardiac damage. While regression of these cardiac damages is expected following aortic valve replacement, the reversal of cardiac damage based on this staging system has not been described. Purpose: This study aimed to describe and stage the changes in cardiac structure and function at 6 months and 1 year after transcatheter aortic valve implantation (TAVI) in patients with symptomatic severe AS. Methods: This was a retrospective, single center, longitudinal observational study. Echocardiographic data of patients who underwent TAVI were retrieved and analysed. Results: From May 2018 to Feb 2021, 31 patients underwent TAVI. 5 patients were excluded due to death <6 months post-procedure (n=2) and incomplete echocardiographic data (n=3). The mean age of the remaining 26 patients was 70.9±9.4 years, 57.7% were male, and 34.6% bicuspid aortic valve. After TAVI, transvalvular aortic mean pressure gradient reduced from 45.2±14.5 mmHg to 8.0±5.4 mmHg (p<0.001), and aortic valve area increased from 0.57±0.21 cm2 to 1.75±0.68 cm2 (p<0.001). At baseline, 6-month and 1-year, the left ventricular mass index (LVMi) were 183.4±60.7g/m2, 150.8±55.3 g/m2 and 126.8±42.1 g/m2 (p<0.001) respectively; left-atrial volume index (LAVI) were 60.4±22.8 ml/m2 , 51.7±23.8ml/m2, and 48.1±23.6ml/m2 (p=0.009) respectively; left ventricular ejection fraction (LVEF) were 52.3±25.4%, 64.2±29.3%, and 62.4±12.1% (p=0.005) respectively. Based on the proposed cardiac damage staging for AS, at baseline 38% of patients were stage 1, 65.4% stage 2, 7.7% stage 3 and 23.1% stage 4. At 1 year, 8.3% were stage 0, 29.2% stage 1, 58.3% stage 2, and 4.2% stage 4. 12 patients (46%) showed improvement in cardiac damage staging, and the other 14 (54%) remained in the same stage. Conclusion: In patients with symptomatic severe AS, there were overall significant regression in LVMi and LAVI, and improvement in LVEF at 1 year after TAVI. However, improvement in cardiac damage staging was observed in only 46% of patients