Applications of luminescence techniques to the study of the lunar surface

Optical fluorescence spectra of rock-forming minerals for identifying mineral grains found on lunar surfac

Differential Reaction of Hosts, Gene Characterization and Management of Huanglongbing Using Chemical Treatments

Citrus is an important crop worldwide and the total production of citrus was about 105.4 million tons in 2006. Unfortunately many diseases have been threatening citrus. The disorder of citrus described as Huanglongbing (HLB) which is known as citrus greening disease is caused by the fastidious phloem limited bacterium in the genus Candidatus Liberibacter and caused severe damage on citrus in more than forty countries including Malaysia. Although HLB has been detected in citrus in Malaysia, there have been few reported studies in the country. Study on screening the local and non-local Citrus species in Malaysia would be useful to select the best rootstocks and interstocks against the HLB causing greening disease in Citrus species. There is also very little information on seed transmission of HLB disease,pathogen movement and the good agriculture practices there can control and reduce greening disease severity of citrus. Seeds were collected from infected trees and germinated in a screenhouse condition. New leaves were collected two months after germination for detection of the HLB using conventional PCR. HLB was not detected in the seed and HLB is not a seed borne disease. The healthy Citrus reticulata (Limau madu) seedlings were used to detect the HLB pathogen movement. They were inoculated using grafting method and the HLB movement evaluated using PCR test after two months. HLB can reach to the roots system twenty six weeks after inoculation. This means that resistant or tolerant rootstocks maybe effective to control or to reduce the severity of HLB because rootstocks provide the root system for the scion. Screening of eighteen Citrus species for susceptibility to HLB was carried out through grafting. C. reticulata that showed typical symptoms of HLB was identified and confirmed by PCR test and used as a source of inoculums. Infected Citrus species showed low total biomass, plant heightand stem diameter when compared to non-inoculated Citrus species. The C.reticulata, C. sinensis, and C. microcarpa showed lowest total biomass, plant height and stem diameter. HLB was detected on 15 species by PCR test, and the species were categorized into three groups; severe group from 58 to 80% severity, includes C. reticulata, C. sinensis, C. reshni (cleopatra), moderate group from 41 to 50% severity, includes Furtunella spp. (Kasturi Chini), C. macrophylla, C. microcarpa (Kasturi), mild group from 17 to 25% severity, includes C.medica, C. aurantifolia (Limau nipis), Citrus sp. (Limau naga), C. jambhiri and three Citrus sp. (Sr.No. 12,15 and 16). HLB was detected in C. aurantium and C. aurantifolia by conventional PCR test (16% PCR test and without symptoms). Effects of rootstocks and interstocks against HLB disease were studied. The tolerant and resistant species were chosen for rootstocks and interstocks and evaluated using conventional and nested PCR. HLB symptom was not observed when C. grandis used as a rootstock and C. hystrix used as an interstock and vice versa with C. reticulata as the scion. In this combination, dry matter, plant height and stem diameter also were significantly increased compared to combination with C.aurantium and C. aurantifolia. High percentage of disease severity was measured in combination between C. aurantum rootstock and C. aurantifolia interstock. Ca. Liberibacter asiaticus was detected in all combinations using nested PCR. Effects of chemical treatments on HLB infected C. reticulata orchard were conducted in Kuala Terengganu. The results showed a significant difference among the treatments. Fruit quantity and quality were significantly increased on treatments T4 (antibiotic + GA3), T7 (antibiotic + GA3 + foliar fertilizer) and T5 (antibiotic + foliar fertilizer) compared to fruit quantity and quality of T8 (control). Total thickness of cell wall also were significantly increased on T4, T7, T5 and T6 (GA3 + foliar fertilizer) compared to T8 (control), T3 (foliar fertilizer), T2 (GA3) and T1 (antibiotic). HLB bacteria were successfully detected using nested-PCR on all treatments. Spherical and rod shape of Ca. Liberibacter asiaticus bacteria were detected in sieve tube cells of phloem. Cross section of sieve tube showed abundant bacteria on the cells and it damaged cell wall and middle lamella. A new strain of HLB was successfully obtained and registered (GU133055) in NCBI gene bank as new strain of HLB from C. reticulata in Terengganu,Malaysia

Developments in quantitative luminescence techniques

Developments in quantitative luminescence technique

Huanglongbing detection, gene sequencing and cell wall thickness modification in infected Citrus reticulata after chemical treatments.

Huanglongbing (HLB), also known as the citrus greening disease, is a destructive disease that has affected citrus plants in more than 40 countries worldwide. HLB is very difficult to control when the vector is spread in the citriculture areas. As presently there is no effective treatment for the citrus plants infected by the HLB disease, this study investigates chemical treatments using GA3, an antibiotic (Oxi-tetracycline), a foliar fertilizer and a combination of these chemicals to stimulate resistance to HLB in citrus plants. It employs a RCBD design with three replications. Aqueous solutions of the treatments were prepared and sprayed on whole trees and a small dose of antibiotic was injected into the trunks of the trees. Conventional PCR was not able to detect HLB bacteria in T7 but it was detected in all treatments using second conventional PCR. A comparison of the mean thickness of treated plants showed that thick cell walls were found in T4 and T7. A new strain of HLB was identified and registered in the NCBI gene bank database (GU133055) from Terengganu

X-ray absorption branching ratio in actinides: LDA+DMFT approach

To investigate the x-ray absorption (XAS) branching ratio from the core 4d to valence 5f states, we set up a theoretical framework by using a combination of density functional theory in the local density approximation and Dynamical Mean Field Theory (LDA+DMFT), and apply it to several actinides. The results of the LDA+DMFT reduces to the band limit for itinerant systems and to the atomic limit for localized f electrons, meaning a spectrum of 5f itinerancy can be investigated. Our results provides a consistent and unified view of the XAS branching ratio for all elemental actinides, and is in good overall agreement with experiments.Comment: 6 pages, 4 figure

Control of saltwater intrusion by aquifer storage and recovery

This is the final version of the article. Available from the publisher via the DOI in this record.Published Online 18th August 2016This paper presents the results obtained from the application of aquifer storage and recovery (ASR) technique to control seawater intrusion (SWI) in coastal aquifers. The study is based on the numerical modelling experiments performed using the SUTRA (Saturated–Unsaturated TRAnsport) finite-element code on the Wadi Ham aquifer in the UAE. A three-dimensional numerical model of this aquifer is developed and calibrated based on the available hydrogeological data in real scale. A significant amount of SWI has been calculated for the year 2015 due to the high rates of pumping from the available local well fields. To study the future responses of the aquifer to different control actions, the transient responses of SWI are simulated over a 10-year planning horizon. The proposed management measure (ASR) is implemented in repeated cycles of artificial recharge, storage and recovery using an additional set of wells defined in the model. The results show that ASR is a reliable method in controlling SWI in coastal aquifer systems besides its conventional role in subsurface water banking.The authors acknowledge their gratitude to the British Council, UK, for providing funding (project code: SH-04509) to support this research

BMI1 and TWIST1 Downregulated mRNA Expression in Basal Cell Carcinoma

Background: BMI1, TWIST1 and SNAI2/SLUG have been implicated in aggressive behavior of squamous cell carcinoma (SCC) and melanoma and BMI1 expression could identify subtypes of Merkel cell carcinoma (MCC). However, BMI1, TWIST1 and SNAI2 expression levels in basal cell carcinomas (BCCs) have not been elucidated. We hypothesized BCC could be a good model system to decipher mechanisms which inhibit processes that drive tumor metastasis. The aim of this study was to examine the mRNA expression level of BMI1, TWIST1, and SNAI2 in BCCs. Materials and Methods: Thirty-five fresh non-metastatic BCC tissue samples and seven fresh normal skin tissue samples were evaluated by real-time RT-PCR. Results: BMI1 and TWIST1 demonstrated marked down-regulation (p< 0.00l, p= 0.00l respectively), but SNAI2 showed no significant change (p=0.12). Conclusions: Previous literature has clearly demonstrated a positive association between BMI1 and TWIST1 expression and metastatic BCC, aggressive SCC and melanoma. Here, we demonstrated a negative association between BMI1 and TWIST1 mRNA expression level and BCC

Effective swimming strategies in low Reynolds number flows

The optimal strategy for a microscopic swimmer to migrate across a linear shear flow is discussed. The two cases, in which the swimmer is located at large distance, and in the proximity of a solid wall, are taken into account. It is shown that migration can be achieved by means of a combination of sailing through the flow and swimming, where the swimming strokes are induced by the external flow without need of internal energy sources or external drives. The structural dynamics required for the swimmer to move in the desired direction is discussed and two simple models, based respectively on the presence of an elastic structure, and on an orientation dependent friction, to control the deformations induced by the external flow, are analyzed. In all cases, the deformation sequence is a generalization of the tank-treading motion regimes observed in vesicles in shear flows. Analytic expressions for the migration velocity as a function of the deformation pattern and amplitude are provided. The effects of thermal fluctuations on propulsion have been discussed and the possibility that noise be exploited to overcome the limitations imposed on the microswimmer by the scallop theorem have been discussed.Comment: 14 pages, 5 figure

Power network and smart grids analysis from a graph theoretic perspective

The growing size and complexity of power systems has given raise to the use of complex network theory in their modelling, analysis, and synthesis. Though most of the previous studies in this area have focused on distributed control through well established protocols like synchronization and consensus, recently, a few fundamental concepts from graph theory have also been applied, for example in symmetry-based cluster synchronization. Among the existing notions of graph theory, graph symmetry is the focus of this proposal. However, there are other development around some concepts from complex network theory such as graph clustering in the study. In spite of the widespread applications of symmetry concepts in many real world complex networks, one can rarely find an article exploiting the symmetry in power systems. In addition, no study has been conducted in analysing controllability and robustness for a power network employing graph symmetry. It has been verified that graph symmetry promotes robustness but impedes controllability. A largely absent work, even in other fields outside power systems, is the simultaneous investigation of the symmetry effect on controllability and robustness. The thesis can be divided into two section. The first section, including Chapters 2-3, establishes the major theoretical development around the applications of graph symmetry in power networks. A few important topics in power systems and smart grids such as controllability and robustness are addressed using the symmetry concept. These topics are directed toward solving specific problems in complex power networks. The controllability analysis will lead to new algorithms elaborating current controllability benchmarks such as the maximum matching and the minimum dominant set. The resulting algorithms will optimize the number of required driver nodes indicated as FACTS devices in power networks. The second topic, robustness, will be tackled by the symmetry analysis of the network to investigate three aspects of network robustness: robustness of controllability, disturbance decoupling, and fault tolerance against failure in a network element. In the second section, including Chapters 4-8, in addition to theoretical development, a few novel applications are proposed for the theoretical development proposed in both sections one and two. In Chapter 4, an application for the proposed approaches is introduced and developed. The placement of flexible AC transmission systems (FACTS) is investigated where the cybersecurity of the associated data exchange under the wide area power networks is also considered. A new notion of security, i.e. moderated-k-symmetry, is introduced to leverage on the symmetry characteristics of the network to obscure the network data from the adversary perspective. In chapters 5-8, the use of graph theory, and in particular, graph symmetry and centrality, are adapted for the complex network of charging stations. In Chapter 5, the placement and sizing of charging stations (CSs) of the network of electric vehicles are addressed by proposing a novel complex network model of the charging stations. The problems of placement and sizing are then reformulated in a control framework and the impact of symmetry on the number and locations of charging stations is also investigated. These results are developed in Chapters 6-7 to robust placement and sizing of charging stations for the Tesla network of Sydney where the problem of extending the capacity having a set of pre-existing CSs are addressed. The role of centrality in placement of CSs is investigated in Chapter 8. Finally, concluding remarks and future works are presented in Chapter 9

Assessment van Kinderen en jongeren: noodzaak om de blik te verruimen

Het onderwijs wordt geconfrnteerd met het dilemma om deprstaties en rendement van leerlingen te verhogen en anderzids ook iets te doen voor een groelend aantal uitvallers of onderpresteerders. Het Daffodil.project is een Europees Comenius- project is een Europees Comenius_multilateral samenwerkingsproject met partners uit 7 landen (Belgie, Hongarije, Zweden,Portugal, Noorwegen, Roemenie en de Britse Maagdeneilanden)met als doel een model te ontwikkelen dat bruikbaar is om het functioneren van kinderen met een probleem beter in kaart te brege