Groundnut rosette disease management

Groundnuts are a key crop in eastern Uganda, grown for both food and income. The major factor limiting production is groundnut rosette disease, a virus disease transmitted by aphids. This project built on previous CPP epidemiological research in Malawi which identified new sources of resistance to aphids and to rosette disease. Screening methodologies were developed to enhance the efficiency of groundnut improvement programmes. Working closely with researchers, agricultural extension agents, NGOs and farmers, the project’s ultimate aim was to to develop sustainable management strategies for groundnut rosette disease, based primarily on the use of improved groundnut varieties with durable resistance to pests and diseases. The availability of new, short-duration, disease-resistant groundnut varieties will assist a substantial number of smallholder farmers to increase their incom

Power Allocation for Uniform Illumination with Stochastic LED Arrays

Light has traditionally been used for making objects visibl e to the naked eye. Lately, there has been tremendous interest in using it for free space communication [1]. This has simultaneously been accompanied by significant interest in light emitting diodes (LEDs) that have been replacing conventional light sources in almo st all applications [2–4]. Fair amount of existing literature has focused on achieving unif orm irradiance over a planar surface [5–8], beginning with the problem of finding the opti mal LED geometry at the light source to achieve uniform irradiance [9]. This was don e by using the irradiance distributions at the closest points on the incident surface . The case of LEDs using a freeform lens with a large view angle has been considered in [ 10]. More literature on similar themes is available in [11,12]

A comparative evaluation : oral leukoplakia surgical management using diode laser, CO2 laser, and cryosurgery

The comparatively evaluate the three surgical treatment modalities namely cryosurgery, diode and CO2 laser surgery in terms of healing outcomes on the day of surgery, first and second week post operatively and recurrence at the end of 18 months was assessed. Thirty selected patients were divided randomly into three groups. Each group comprising of ten patients were subjected to one of the three modalities of treatment namely cryosurgery, diode laser or CO2 laser surgery for ablation of OL. Obtained data was analyzed using mainly using Chi-square and Anova tests. Study showed statistical significant differences (p > 0.05) for evaluation parameters like pain, edema and scar. The parameters like infection, recurrence, bleeding showed no statistical significance. Pain was significantly higher in CO2 laser surgery group as compared with diode laser group. There was no recurrence observed at the end of the 6 months follow up period in all the three study groups. Observations from the study highlights that all three surgical modalities used in this study were effective for treatment of OL, and the overall summation of the results of the study showed that laser therapy (CO2 and Diode) seems to offer better clinically significant results than cryotherapy

GOVERNING HUMAN-ELEPHANT CONFLICT: A CRITICAL INSTITUTIONAL APPROACH TO DECOLONIZING CONSERVATION IN THE CHOBE ENCLAVE OF BOTSWANA

Within the largest population of African savanna elephants (Loxodonta africana) on the continent, Botswana’s Chobe Enclave is a group of agricultural communities bounded by protected areas and an international border. Human-elephant conflict (HEC) is a major concern for both Enclave residents and conservation practitioners. This research asked how institutional arrangements shape the governance of HEC in the Chobe Enclave. Previous research has shown that technical solutions to HEC must be complemented by integrating governance across local, national, and international levels to make elephant conservation and management more inclusive of people who live alongside elephants. This research employed a Critical Institutional approach and in-depth interviews with Enclave residents and conservation practitioners to explore how institutional arrangements shaped HEC governance. People in the Chobe Enclave experience HEC, not only because of increasing human and elephant populations, but also as the result of historic policies dating to the colonial era. As a result, Enclave residents experience both the impacts of elephants and conflict with conservation practitioners over the implementation of HEC reduction strategies. These results suggest that conservation practitioners should move from conservation interventions based in communities to those that are led by communities. This research recommends a series of strategies to restore HEC governance to people in the Chobe Enclave

Enzymology of L-proline synthesis

The accumulation of free L-proline in leaves as a response to water deficit is well documented. Accumulation is caused by stress enhanced-de novo proline synthesis from glutamic acid. Three enzymes, gamma-glutamyl kinase (GK, EC 2.7.2.11), gamma-glutamyl phosphate reductase (GPR, EC 1.2.1.41), and pyrroline-5-carboxylate reductase (PCR, EC 1.5.1.2) catalyze the pathway in other organisms;A continuous assay for GK was developed. A crude preparation from etiolated shoots of Vigna radiata L. was capable of synthesizing pyrroline-5-carboxylate (P5C) from glutamic acid. Attempts to purify GPR activity yielded P5C dehydrogenase activity that was not phosphate-dependent. PCR was the only enzyme whose activity could be measured;Protoplasts were made from leaves of Pisum sativum L., lysed, and fractionated on a Percoll gradient. PCR activity was found in chloroplasts. PCR activity from pea chloroplasts and etiolated pea shoots was compared. PCR activity from both extracts is stimulated at least twofold by 100 mM KCl and 10 mM MgCl[subscript]2. The pH profiles of PCR activity from both extracts reveal two separate pH optima at 6.5 and 7.5. PCR activity from etiolated pea shoots was 100-fold greater than that from pea chloroplasts. Three nonionic detergents (NP-40, CHAPS, and CHAPSO) doubled the yield of PCR activity from pea chloroplasts;PCR was partially purified from pea leaf chloroplasts and from etiolated pea shoots. PCR activity from chloroplasts exhibited a preference for NADPH. PCR activity from etiolated shoots had a higher K[subscript] m for NADH than for NADPH. The V[subscript] max was also greater with NADH than with NADPH. PCR activity from etiolated shoots was inhibited by 50 mM proline, 2 mM azetidine-2-carboxylate, and 2 mM thiazolidine-4-carboxylate. The molecular mass of native PCR was greater than 100 kd. The pI of native PCR was 7.8. Participation of PCR in the regulation of metabolism during stress is indicated

Grapevine leafroll-associated virus 3.

Grapevine leafroll disease (GLD) is one of the most important grapevine viral diseases affecting grapevines worldwide. The impact on vine health, crop yield, and quality is difficult to assess due to a high number of variables, but significant economic losses are consistently reported over the lifespan of a vineyard if intervention strategies are not implemented. Several viruses from the family Closteroviridae are associated with GLD. However, Grapevine leafroll-associated virus 3 (GLRaV-3), the type species for the genus Ampelovirus, is regarded as the most important causative agent. Here we provide a general overview on various aspects of GLRaV-3, with an emphasis on the latest advances in the characterization of the genome. The full genome of several isolates have recently been sequenced and annotated, revealing the existence of several genetic variants. The classification of these variants, based on their genome sequence, will be discussed and a guideline is presented to facilitate future comparative studies. The characterization of sgRNAs produced during the infection cycle of GLRaV-3 has given some insight into the replication strategy and the putative functionality of the ORFs. The latest nucleotide sequence based molecular diagnostic techniques were shown to be more sensitive than conventional serological assays and although ELISA is not as sensitive it remains valuable for high-throughput screening and complementary to molecular diagnostics. The application of next-generation sequencing is proving to be a valuable tool to study the complexity of viral infection as well as plant pathogen interaction. Next-generation sequencing data can provide information regarding disease complexes, variants of viral species, and abundance of particular viruses. This information can be used to develop more accurate diagnostic assays. Reliable virus screening in support of robust grapevine certification programs remains the cornerstone of GLD management

Resistive switching in ferroelectric polycrystalline Yttrium Manganese Oxide thin films

A memristor is a two-terminal device which exhibits a hysteresis loop in the current-voltage characteristics. Resistive switching refers to reversible non-volatile change in state of the resistance. There exists a wide range of materials which show resistive switching i.e, phase change materials are used in today’s technology which are a main component of the resistive random access memory. In actual research, mostly metal oxides are investigated regarding their resistive switching which is based on migration of anions and cations. Additionally, in hexagonal manganites, h-RMnO3 (R = Y, In, Sc, Ho,...,Lu), the multiferroic properties and nano-sized conducting domain walls introduce further interesting aspects in this material class which may contribute to additional features in resistive switching. This dissertation investigates the resistive switching in yttrium manganite thin film (Y1Mn1O3, Y0.95Mn1.05O3, Y1Mn0.99Ti0.01O3 and Y0.94Mn1.05Ti0.01O3) based metal-insulator-metal structures with different top electrodes (Au or Al) and bottom electrodes (Pt or Pt/Ti or Pt/Cr) in 2-point DC probe measurements. Yttrium manganite thin films have been deposited by pulsed laser deposition on metal coated SiO2/Si substrates. Electrical characterization of yttrium manganite thin films in a metal-insulator-metal structure exhibit electroforming-free unipolar resistive switching. High voltages and currents are required for SET (V_ ) and RESET (I_ ), respectively. The observed resistive switching is assigned to the formation (low resistance state) and rupture (high resistance state) of conductive, metallic-like filaments induced by a thermo-chemical phenomena. Observed unipolar RS is classified as the thermo-chemical memory (TCM) resistive switching phenomena related to the locally increased temperature. The stability of conductive filaments leads to good retention of the programmed states with large memory window (OFF to ON resistance in the order of 10^4 - 10^6, depends on electrodes, electrode size and composition of yttrium manganite thin films). The endurance or number of loading cycles of the resistive switching devices are improved and is in the order of 10^3 for Y1Mn1O3 and Y0.95Mn1.05O3 composition with Al-top electrodes and Pt-bottom electrode. The maximum number of loading cycles is observed for an applied negative bias, a preferential negative polarity for switching the yttrium manganite thin film devices with Au or Al top electrodes and Pt or Pt/Ti bottom electrodes. Whereas, yttrium manganite thin film devices with Pt/Cr-bottom electrode and Al-top electrodes a preferential positive bias is required for switching the devices. Temperature-dependent measurements of yttrium manganite thin films deposited on Pt/SiO2/Si show semiconducting and metallic-like conduction in high resistance state and low resistance state, respectively. The activation energy () extracted in the ohmic region for hopping of holes localized at Mn4+ is in the range of 0.36 eV - 0.43 eV. Scanning electron microscopy in secondary electron emission mode with an in-lens detector and a small acceleration voltage of 1.0 kV is used to characterize the ferroelectric charged domain network formation in polycrystalline hexagonal yttrium manganite thin film. The observed bright regions correspond to local polarization vector with upward polarization components (+P ) and dark regions to local polarization vector with downward polarization components (-P ). A dense domain network is observed for Mn-rich samples (Y0.95Mn1.05O3 and Y0.94Mn1.05Ti0.01O3) in comparison to Y1Mn1O3 and Y1Mn0.99Ti0.01O3 with smaller grains show isolated charged domains. The observed dependency of different compositions to the charged domain density network in yttrium manganite thin films may influenced by different factors: stoichiometry gradient, oxygen, dopant concentration and the resulting grain structure.Ein Memristor ist ein Bauelement, welches eine Hysterese beim Vermessen seiner IU-Kennlinie aufweist. Dieses als „Widerstandsschalten“ bezeichnete Phänomen beruht auf der nichtflüchtigen Veränderung des Widerstandes. Es existiert eine breite Auswahl an Materialien, welche Widerstandsschalten zeigen, z.B. sind Phasenwechselmaterialien die Hauptkomponenten in aktuellen RRAMs. Aktuelle werden hauptsächlich Metalloxide untersucht, welche durch Migration von Anionen und Kationen Widerstandsschalten hervorrufen. Weitere Materialien wie hexagonale Manganoxidverbindungen RMnO3 (R = Y, In, Sc, Ho,...,Lu), besitzen zusätzliche multiferroische Eigenschaften, bei denen geladene Domänengrenzen weitere interessante Aspekte in dieser Materialklasse einführen und das Widerstandsschalten beeinflussen können. Die vorliegende Dissertation untersucht das Widerstandsschalten in Yttriummanganoxid-Dünnfilmen mit unterschiedlichen Kompositionen und unterschiedlichen Elektrodenmaterialien. Y1Mn1O3, Y0.95Mn1.05O3, Y1Mn0.99Ti0.01O3 und Y0.94Mn1.05Ti0.01O3, wurden mittels gepulster Laserdeposition auf metallisierte Si/SiO2 Substrate abgeschieden. Die elektrische Charakterisierung von Yttriummanganoxid-Dünnfilmen in einer Metall-Isolator-Metall Sandwichstruktur weist auf elektroformierungsfreies, unipolares Widerstandsschalten hin. Das beobachtete Widerstandsschalten wird auf die Formierung (niederohmiger Zustand) und Zerstörung (hochohmiger Zustand) des leitfähigen, metallischen Filaments (geladenen Domänengrenzen oder auch Vortices), verursacht durch thermisch-chemische Vorgänge, zurückgeführt. Die geladenen Domänengrenzen und/oder Vortices in Yttriummanganoxid-Dünnfilmen beeinflussen unter Umständen als nanoskalige Objekte die Formierung der leitfähigen Filamente. Die Stabilität der leitfähigen Filamente führt zu einer guten Langzeitspeicherung der programmierten Zustände, welche auch ein sehr großes Speicherfenster (Widerstandsverhältnis zwischen Aus/An-Zustand von 10^5) aufweisen. Die großen Widerstandsverhältnisse sind z.B. für die Herstellung von Auswahlschaltern (selektoren) in Crossbar-Strukturen notwendig, um die möglicherweise auftretenden Kriechströme in Crossbar-Strukturen zu unterdrücken, welche sonst Lesefehler der adressierten Zellen hervorrufen würden. Die Wiederbeschreibbarkeit ist in der Größenordnung von ca. 10^3, abhängig von der chemischen Zusammensetzung des Yttriummanganoxide-Dünnfilmes und vom verwendeten Elektrodenmaterial. Resultate der Charakterisierung mittels Rasterelektronenmikroskopie im Sekundärelektronenmodus mit einer kleinen Beschleunigungsspannung von 1.0 kV weisen auf geladene ferroelektrische Domänen in polykristallinem hexagonalen YMnO3 Dünnfilmen hin. Deswegen muß der Einfluss von geladenen Domänengrenzen und multiferroischen Vortices auf das beobachtete Widerstandsschalten in hexagonalem YMnO3 berücksichtigt werden

Transcriptional Changes Underlying Elemental Stoichiometry Shifts in a Marine Heterotrophic Bacterium

Marine bacteria drive the biogeochemical processing of oceanic dissolved organic carbon (DOC), a 750-Tg C reservoir that is a critical component of the global C cycle. Catabolism of DOC is thought to be regulated by the biomass composition of heterotrophic bacteria, as cells maintain a C:N:P ratio of ∼50:10:1 during DOC processing. Yet a complicating factor in stoichiometry-based analyses is that bacteria can change the C:N:P ratio of their biomass in response to resource composition. We investigated the physiological mechanisms of resource-driven shifts in biomass stoichiometry in continuous cultures of the marine heterotrophic bacterium Ruegeria pomeroyi (a member of the Roseobacter clade) under four element limitation regimes (C, N, P, and S). Microarray analysis indicated that the bacterium scavenged for alternate sources of the scarce element when cells were C-, N-, or P-limited; reworked the ratios of biomolecules when C- and P- limited; and exerted tighter control over import/export and cytoplasmic pools when N-limited. Under S limitation, a scenario not existing naturally for surface ocean microbes, stress responses dominated transcriptional changes. Resource-driven changes in C:N ratios of up to 2.5-fold and in C:P ratios of up to sixfold were measured in R. pomeroyi biomass. These changes were best explained if the C and P content of the cells was flexible in the face of shifting resources but N content was not, achieved through the net balance of different transcriptional strategies. The cellular-level metabolic trade-offs that govern biomass stoichiometry in R. pomeroyi may have implications for global carbon cycling if extendable to other heterotrophic bacteria. Strong homeostatic responses to N limitation by marine bacteria would intensify competition with autotrophs. Modification of cellular inventories in C- and P-limited heterotrophs would vary the elemental ratio of particulate organic matter sequestered in the deep ocean

ENERGY EFFICIENT INTRUSION DETECTION FOR NFV CLOUD INFRASTRUCTURES USING MACHINE LEARNING TECHNOLOGY

Recent times have seen a steady shift of technology from traditional software models to the cloud.Widespread deployments of Network Function Virtualization (NFV) technology will replace many physical appliances in telecommunication networks with software executed on cloud platforms. Setting compute servers continuously to high-performance operating modes is a common NFV approach for achieving predictable operations. Intrusion detection systems are one of the most suitable security solutions for protecting cloud based environments. The Dynamic Voltage-Frequency Scaling (DVFS) technology available in Intel processors is a known option for adapting the power consumption to the workload, but it is not optimized for network traffic processing workloads. This paper proposes energy efficient intrusion detection for NFV Cloud infrastructures using Machine learning technology. Attack presence is confirmed by performing Machine learning technique with belief propagation. Performance measures such as Detection Rate and Accuracy are used to evaluate the performance of the approach. From results obtained accuracy is 94.11% and achieved detection rate as 70 sec. transmission rate of proposed method is better than compared to setting the maximum frequency or using the ondemand governor