Erratic Occurrence Research Articles

Finding and identifying platinum group elements in the Eastman layered mafic intrusion

Platinum group elements (PGEs) are commonly hosted by base metal sulfides (BMSs, e.g. chalcopyrite or pentlandite) or platinum group minerals (PGMs). PGE-bearing phases are generally small, ranging from tens of nanometres to a few micrometres. In addition, PGEs can be hosted in PGMs, either intimately associated with BMSs or spatially separated. This poses a difficulty in their detection and analysis, and leads to uncertainty in identification of their mineral hosts. Their erratic occurrence introduces a substantial nugget effect in bulk rock assays, used to evaluate deposit economics on a larger scale. Knowledge of PGE hosts has a direct influence on resource management and extraction efficiency, making the understanding of mineral distribution important for processing. The Eastman Ultramafic Intrusion is a layered mafic–ultramafic intrusive complex in the Eastern Kimberley of Western Australia. Samples from Cu–Co–Ni–PGE exploration drilling at Eastman were bulk-assayed and found to contain up to 2.39 ppm PGEs. The rocks have been strongly altered and no longer represent their primary magmatic mineral assemblage and textures. To better understand the Eastman PGE mineralogy, we applied a multi-method approach of quantitative analytical electron microscopy, 3D scanning and in situ mass spectrometry. We find that Pt is primarily hosted in sperrylite, whereas Pd is mainly associated with kotulskite, pseudomertieite, testibiopalladite, sudburyite and michenerite. Additionally, minor Pt and Pd occur in solid solution within cobaltite, as well as Rh-rich cobaltite (hollingworthite). Spatially, PGMs and cobaltite are mostly clustered on a millimetric scale, and BMSs on a micrometric scale.

Bumble bee microbiota shows temporal succession and increase of lactic acid bacteria when exposed to outdoor environments.

The large earth bumble bee (Bombus terrestris) maintains a social core gut-microbiota, similar as known from the honey bee, which plays an important role for host health and resistance. Experiments under laboratory conditions with commercial hives are limited to vertically transmitted microbes and neglect influences of environmental factors or external acquisition of microbes. Various environmental and landscape-level factors may have an impact on the gut-microbiota of pollinating insects, with consequences for pollinator health and fitness in agroecosystems. Still, it is not fully clear whether access to different flower diversities will have a significant influence on the bumble bee microbiota. Here, we tested in a semi-field experiment if the bumble bee microbiota changes over time when exposed to different flower diversities within outdoor flight cages. We used commercial hives to distinguish between vertically and horizontally transmitted bacteria, respectively from the nest environment or the exposed outside environment. The sequential sampling of foraging workers over a period of 35 days indicated a temporal progression of the bumble bee microbiota when placed outside. The microbiota increased in diversity and changed in composition and variability over time. We observed a major increase in relative abundance of the families Lactobacillaceae, Bifidobacteriaceae and Weeksellaceae. In contrast, major core-taxa like Snodgrassella and Gilliamella declined in their relative abundance over time. The genus Lactobacillus showed a high diversity and strain specific turnover, so that only specific ASVs showed an increase over time, while others had a more erratic occurrence pattern. Exposure to different flower diversities had no significant influence on the progression of the bumble bee microbiota. The bumble bee microbiota showed a dynamic temporal succession with distinct compositional changes and diversification over time when placed outdoor. The exposure of bumble bees to environmental conditions, or environmental microbes, increases dissimilarity and changes the gut-community composition. This shows the importance of environmental influences on the temporal dynamic and progression of the bumble bee microbiota.

Surgical phase and instrument recognition: how to identify appropriate dataset splits

PurposeMachine learning approaches can only be reliably evaluated if training, validation, and test data splits are representative and not affected by the absence of classes. Surgical workflow and instrument recognition are two tasks that are complicated in this manner, because of heavy data imbalances resulting from different length of phases and their potential erratic occurrences. Furthermore, sub-properties like instrument (co-)occurrence are usually not particularly considered when defining the split.MethodsWe present a publicly available data visualization tool that enables interactive exploration of dataset partitions for surgical phase and instrument recognition. The application focuses on the visualization of the occurrence of phases, phase transitions, instruments, and instrument combinations across sets. Particularly, it facilitates assessment of dataset splits, especially regarding identification of sub-optimal dataset splits.ResultsWe performed analysis of the datasets Cholec80, CATARACTS, CaDIS, M2CAI-workflow, and M2CAI-tool using the proposed application. We were able to uncover phase transitions, individual instruments, and combinations of surgical instruments that were not represented in one of the sets. Addressing these issues, we identify possible improvements in the splits using our tool. A user study with ten participants demonstrated that the participants were able to successfully solve a selection of data exploration tasks.ConclusionIn highly unbalanced class distributions, special care should be taken with respect to the selection of an appropriate dataset split because it can greatly influence the assessments of machine learning approaches. Our interactive tool allows for determination of better splits to improve current practices in the field. The live application is available at https://cardio-ai.github.io/endovis-ml/.

Isoetin 2′-O-α-l-arabinopyranoside-5′-O-β-d-glucopyranoside

Isoetin derivatives are a rare class of flavonoids with a rather erratic occurrence across the plant kingdom. The Cichorieae tribe of the Asteraceae family has proven to be a rich source and a centre of chemical diversity of this class of compounds. Here, we describe the chromatographic isolation and mainly NMR-based structure elucidation of a previously undescribed isoetin derivative from Leontodon hispidus L. (Asteraceae, Cichorieae). The chemophenetic relevance is discussed briefly.

Scoping Food Security at Barabardiya Municipality

The article investigates the state of food security of Barabardiya urban municipality, Bardiya. Food security is difficult to assess, with erratic occurrence rates and patterns. Policies should address the behavioral issues that influence our dining decisions. Sociology is particularly well-suited to tackling food security since it is multidisciplinary in nature and encompasses many interdisciplinary ideas in addition to social and economic factors. The research in this study was evaluated using data gathered for my PhD dissertation. The main search engines for finding pertinent data are Google Scholars, JSTOR, Z-library, Research Gate, and the Central Bureau of Statistics of Nepal. From a total of 5981 families, 361 homes were randomly selected for thestudy.89.47 percent of the 361 respondents claimed they did not eat any less than they thought they ought to. Nearly all respondents (96.12%) responded "No," suggesting they were not required to forgo a meal. 63.43 percent of those surveyed claimed that their household never ran out of food. Nearly 93, 4% of those surveyed reported being hungry yet going without food. 96.7 percent of individuals surveyed claimed they went without food for the entire day. According to the investigation’s results, Bardiya has a decent level of food security.

Factors Determining Small-Scale Farmers’ Adoption of Climate Adaptation Methods in Jubek State, South Sudan

Agricultural production in South Sudan has experienced climate variability, the erratic occurrence of climate phenomena affects land use through frequent drought and flooding hence needs climate adaptations. There is less information about factors determining farmers adopting climate change adaptations in South Sudan. Therefore, the current research aimed at exploring factors that influence the adaptation measures taken by farmers for Jubek State in South Sudan. The study adopted a stratified sampling method to identify areas and respondents that questionnaires were administered for data collection and there were 395 farmers who were sampled systematically during the research study. The data collected were entered and coded, then statistically analysed using a logistic regression model to analyse determinants to adopting climate adaptations. The study found that gender, marital status, code of employment, size of the household, and size of the farm were significantly influencing adoption of climate changes adaptations (p< 0.05). The farmers practice of farming activities in respect to the adaptation methods used had a probability of increasing the number of climate adoption for higher crop yield. It was concluded that prescribed policies need to incorporate socio-economic factors to provide valuable and efficient climate adaptation methods

Pilot Review Study on the Importance of Treated Agro-Industrial Wastewater to Reuse for Irrigating Agriculture

The main purpose this review study is to present fundamentals of wastewater conservation and treatment method amid at using it for irrigating agriculture in a manner understandable to those most concerned with such knowledge and also to provide the wastewater users with an insight into the many ways in which they are dependent on soil and water for survival. In most parts of Ethiopia, the water needed for crop production is provided mainly by rainfall. These days; however, the effectiveness and sufficiency of rain fall, even in high rainfall receiving areas, is interrupted by its erratic occurrence, uneven distribution, poor soil and water managements. There is also scarcity of water during dry seasons. To achieve this, integrated participation and coordinated efforts of the different institutions is highly considered. After introducing provisions and expressions of wastewater use, this study highlights their global drivers and significance using examples from various parts of the developing world. It is useful in the discussion to differentiate between unplanned use of wastewater resultant from deprived sanitation, and planned use which tries to address matters such as economic or physical water scarcity. Both types of wastewater use can have significant socio-economic benefits but also institutional challenges and risks which require various management approaches. Based on the laboratory test results and the field experimental research activities conducted on cereal crops like wheat and barley as well as the pulse crops of the field pea and Faba bean crops which planted in the agro-industrial wastewater of Asella Malt Factory have performed very well at 25%, 50% and 75% of fresh water and wastewater dilutions in favor of their intensive growth rate performance of the seeds. There is a need for the consequent study to apply the principles of wastewater management and treatment method to use it for irrigating agriculture. The author links wastewater and health to the establishment and implementation of effective, affordable and efficient options for risk reduction. Under the conditions applied in this study, the reuse of treated agro-industrial wastewater for irrigation can be considered an effective way to cope with agricultural water shortage in the Mediterranean area. We can expect the entire information quantified in this paper will influence further applied multidisciplinary research on wastewater use related risk and its alleviation.

Evolution and Features of Dust Devil‐Like Vortices in Turbulent Rayleigh‐Bénard Convection—A Numerical Study Using Direct Numerical Simulation

AbstractDust devils are convective vortices with a vertical axis of rotation that are made visible by entrained soil particles. These soil particles contribute to the atmospheric aerosol input, influencing the Earth radiation budget. Quantifying this contribution requires reliable information about the statistics of dust devils, their formation process, and how they are maintained. In the past, this information was mainly derived from field experiments and large‐eddy simulations (LESs). Field experiments suffer from the erratic occurrence of dust devils and the limited area that can be monitored reliably. In LESs, dust devils cannot be resolved completely, especially close to the ground. Additionally, they are affected by numerical features of surface boundary conditions, as well as subgrid‐scale models in an unknown way. To mitigate these limitations, we employ direct numerical simulations (DNSs) to improve our understanding of dust devils. We comprehensively investigate the statistics and structure of dust devils for Rayleigh numbers up to 1011using DNS of Rayleigh‐Bénard convection between two plates for the first time. We find that dust devil‐like structures occur in DNS with Rayleigh numbers much lower than in the atmosphere (≥107). These results support previous DNS studies in which vortices with vertical axes were observed but not further investigated. The dust devil statistics strongly depend on the Rayleigh number and velocity boundary conditions, but depend little on the aspect ratio of the model domain. Simulated dust devils show very similar properties to convective vortices analyzed in LESs of the atmospheric boundary layer.

A review of the status, distribution and ecology of Friedmann's Lark Mirafra pulpa, including its habitat associations

Friedmann's Lark Mirafra pulpa is a poorly known species endemic to East African savannas, and classified as Data Deficient by BirdLife International. In light of our limited knowledge, I reviewed the species' ecology, status and distribution, finding no more than 51 dated records (or discrete periods of occurrence) in a search of the literature and internet databases. However, the restriction of these records to two distinctive regions of the Chyulu and Nyambeni foothills suggests that Friedmann's Lark may be closely tied to pockets of ash-based soil associated with geologically recent volcanic formations. These gritty, white-coloured soils are characterised by slower drainage in contrast to the region's otherwise widely occurring red soils, and retain year-round the dense grass cover apparently preferred by M. pulpa. It is therefore likely to be the distribution of these ash-based soils and associated dense grassland that determines the distribution of Friedmann's Lark. Based on this hypothesis, and the species' well-known erratic occurrence, its year-round area of occupancy may amount to no more than 20% of its overall extent of occurrence, amounting to c.5,000 km2, potentially qualifying Friedmann's Lark as Near Threatened under IUCN criteria.

Groundwater potential evaluation in the basement complex terrain of Ekiti East Local Government Area, Southwestern Nigeria

Availability of groundwater often constitutes a problem in basement terrain because of its erratic occurrence. Incessant failures of boreholes have been reported in Ekiti East Local Government Area (EELGA), Southwestern Nigeria warranting evaluating its groundwater potential using a multi-criteria model that involved geology, resistivity and thickness (GRT) model of the aquifers across the study area. Thirty-five (35) locations were occupied using vertical electrical sounding (VES) technique employing the Schlumberger electrode array. The VES data were interpreted quantitatively by partial curve matching and 1-D computer iteration to facilitate siting of appropriate boreholes locations. The geophysical survey revealed twelve (12) types of resistivity curve: KH ($$\rho 1 \rho 3 \rho 3>\rho 4 \rho 3>\rho 4>\rho 5)$$, QH ($$\rho 1>\rho 2>\rho 3 \rho 3>\rho 4)$$, HKQ ($$\rho 1>\rho 2 \rho 4>\rho 5)$$, AK (ρ1 ρ4), HA ($$\rho 1>\rho 2 \rho 3 \rho 2 \rho 2>\rho 3 \rho 2 \rho 4<\rho 5)$$. The four-layer curve types observed within the area accounted for 57% of the curve types, while the five-layer types were 43%. The maps of aquifer layer resistivity and aquifer layer thickness were generated and synthesized with the geology of the study area in producing the GRT model groundwater potential map. The groundwater potential map revealed the northern part of the study area as an area with high groundwater potential, while the southern part was characterized as low groundwater potential terrain. EELGA is categorized into low, medium and high groundwater potential zones with the northern part more favorable for siting of boreholes. The groundwater potential map will serve as an exploration guide in addition to its usefulness in groundwater sustainability development.

Enhancement of Small-Scale Runoff Harvesting Ponds in East Africa

Ethiopia is one of the sub-Saharan African countries that is suffering from a recurring drought due to erratic rainfall occurrence both in amount and distribution. The livelihood of the largest portion of the people is dependent on rain-fed agriculture. Thus, crop failure is widely encountered by the peasants of the region because of the erratic nature of the rain and recurrent drought. As a result, millions of people depend upon relief assistance every year. It is therefore, necessary to detach the agricultural sector from its dependency on this seasonally fluctuating rainfall occurrence to supplement crop failure and feed the ever-increasing population of the country. This calls for harnessing runoff that occurs during wet seasons using water harvesting facilities and later use it in safeguarding crop failure through supplementary irrigation. Although harnessing runoff is not uncommon in Ethiopia, one of the major problems in this effort is the problem of excessive seepage losses and bank stability. This research work evaluates the methods that reduce seepage losses from ponds using locally available treatment materials. The treatment materials used were compacting the pond, lining the pond with termite mound and soil-straw mixture. These treatment methods resulted in reducing seepage losses and protected slope failure. soil-straw mixed and termite mound lined ponds contained water up to 47 and 43 days, respectively. This contrasts with the untreated (control) pond which contained water only for about 5 days. These methods are low-cost as local materials are used in the treatment and can be used in areas where seepage and bank stabilities are a problem. Moreover, this work is expected to pave the way for further research in the area. Keywords: level-drop, pond, termite mound, treatment methods, water tightness DOI : 10.7176/JNSR/9-16-01 Publication date : August 31 st 2019

Tills y otros depósitos relacionados con la dinámica glaciar en la Sierra do Xistral: Interpretación de litofacies y reconstrucción paleoglaciar

Los aparatos glaciares que se desarrollaron el a Sierra do Xistral originaron un modelado glaciar poco marcado pero evidente. Se ha descrito la presencia de crestas morrénicas, planas fluvioglaciares, bloques erráticos y kames. La presencia de afloramientos en los que se puedan estudiar depósitos de origen glaciar es relativamente escasa, pero esto no impide que se presenten buenos ejemplos. En el presente trabajo discuten tipos de tills, tanto subglaciares como supraglaciares así como depósitos fluvioglaciares y torrenciales. Su interpretación es un elemento importante a la hora de comprender la dinámica glaciar en este sector. El método de trabajo es el habitual es este tipo de estudio, que comprende una valoración de visu de los distintos afloramientos y su integración en el contexto geomorfológico local.

The new Fast Beam Condition Monitor using poly-crystalline diamond sensors for luminosity measurement at CMS

Abstract The Fast Beam Condition Monitor (BCM1F) is used in CMS to measure beam induced background and precision luminosity. The system in its current implementation was first installed in 2014, equipped with single-crystalline (sCVD) diamond sensors. After some radiation damage, erratic occurrence of HV instabilities required lowering of the operational HV and the system became inefficient, resulting in unstable measurements. The system was replaced in 2017 with poly-crystalline (pCVD) diamond sensors and silicon (Si) sensors. Both new sensor types show significantly better operational stability. The luminosity performance of pCVD and Si based luminosity measurement is discussed.

Estimated volume of water in shallow wells of Ekiti State, Southwestern Nigeria: implications on groundwater sustainability

Volumes of water in shallow wells of Ekiti State Southwestern Nigeria was estimated during the rainy and dry seasons of 2017 to categorize the area into different groundwater potential zones and to scrutinize it for groundwater sustainability and development. Locations of the wells were measured using etrex 12 Channel GPS while dip meter was employed for the water levels and depths of wells. The volume of water in a well was estimated employing V = πr2h (r and h are radius and water column of well, respectively). The wells in the area have low water storage (av. 6.91m3 and 2.70m3 in rainy and dry seasons, respectively). The study area had sufficient quantity of water in the rainy season to meet domestic, agricultural, and industrial requirements as deficiency was met from rainfall replenishment. Groundwater potential evaluation revealed that majority of the study area fell into very poor to poor water categories. Groundwater sustainability and development in the study area is a herculean task due to uncoordinated sitting of wells, low storage of water in the aquifers, and erratic occurrence of the groundwater. Hygiene education should be intensified in the area to forestall the risks post by the principal elements of fecal oral disease transmission.

Occurrence of ice-rafted erratics and the petrology of the KR1 seamount trail from the Australian–Antarctic Ridge

ABSTRACTA multi-disciplinary study of the KR1 segment of the Australian–Antarctic Ridge has been conducted since 2011. We present geochemical and age dating results for samples dredged from three sites on the KR1 seamount trail. The majority of the samples are alkaline ocean island basalts with subdominant enriched tholeiites. The samples from the DG05 bathymetric depression include ice-rafted erratics from Antarctica, which consist of gabbro, diabase, various granitoids, volcanic rocks such as trachyte and rhyolite and deformed or undeformed sedimentary rocks. The main provenance of glacial erratics is considered to be the Ross Sea region. However, Carboniferous to Cretaceous ages of erratics indicate that some of these may originate from the western regions of West Antarctica. Based on the size and topography of the volcanic features and geochemical characteristics of the alkaline ocean island basalts (La/SmN = 2.62–3.88; Tb/YbN = 1.54–2.67) and the enriched tholeiites, the KR1 seamount trail is interpreted to be a submarine hotspot chain that is the product of alkaline volcanic eruption and seafloor spreading.

Polychaete Community of a Marine Protected Area along the West Coast of India-Prior and Post the Tropical Cyclone, Phyan.

Tropical cyclones are extreme random meteorological events that can have profound implications to coastal biodiversities. Given that the frequency, intensity and duration of these events are poised to increase due to the global climate change, understanding the ecological impacts of such erratic occurrences becomes imperative to devise better management strategies. The eventful passage of the tropical cyclone, Phyan, along the northwestern coast of India in November 2009, coupled with the availability of historical data presented a rare opportunity to elucidate the consequences on the polychaete assemblages of the Malvan Marine Sanctuary and their subsequent recovery. This was achieved by comparison of the pre- and post-Phyan seasonal data from four different sites in and around the Sanctuary. MDS analyses and polychaete community parameters suggested conspicuous cyclone related effects on the polychaete community characteristics in the three outer stations off Malvan, whereas the relatively protected bay station remained more or less unscathed. Impacts, attributable to the cyclone apart from seasonal variations, included changes in polychaete composition, reductions in total polychaete density, species diversity, evenness and functional groups. Dominance of the opportunistic polychaete, Paraprionospiopatiens was all pervasive just after Phyan, resulting in poor diversity and evenness values. In the outer stations, diverse feeding modes present prior to the cyclone were replaced by microphagous feeders post the disturbance. However, the study also observed complete recovery as substantiated by the improvement inpolychaete density, diversity indices and re-instatement of multiple feeding guilds in affected areas. This resilience of the coastal waters off Malvan is attributed to its marine protected status, implying that reduced human interference aided rapid revival of damaged ecosystems.

Behaviour of spinel-forming DVM using crucible induction furnaces. A case study on material failure

This article contributes to the understanding of the sintering behaviour of spinel forming dry vibrating mixes (DVM) that are in common use in crucible induction furnaces (CIF) for metallurgic treatment. At present, an unwanted sintering of the DVM as far as to the cold face is reported from the industry. For safety reasons it is indispensable that an unaffected layer is remaining at the cold face of the lining. If not, the material becomes brittle and the risk of crack formation gets unacceptable. The access of liquid melt to the induction coil may cause severe accidents that destroy the furnace which bears the risk of industrial injury.Systematic research on breakout materials by means of SEM-supported microtextural and microanalytical investigations come to the result that a sintering occurs already in areas of the lining where the prevailing temperature could not have exceeded 300°C. Furthermore, it can be carved out that the sintering at the cold face is caused by the formation of spinel. This result is in contradiction to the generally accepted opinion that the spinel formation is kinetically hampered at temperatures lower than 900°C and should not occur. The increased MgO:Al2O3 ratios of the newly formed spinels indicate lower crystallization temperatures. The gradual transformation starts with marginal dissolution of the magnesia grains at the cold face and progrades with the development of skeleton structures of matrix spinels.The spinel formation is favoured of different components as chemical additives, a reduced atmosphere, hydration, and a momentary overheating. However, it is suspected that water and short-term overheating, respectively, play the key role since other known major agents as untypical oxides, and in particular fluorides and chlorides can be excluded by their erratic occurrence. We identified water as a primary unwanted additive which left typical microstructures in magnesia grains of the studied lining breakouts.

Mortality in the Ocean-With Lessons from Hydrothermal Vents off Kueishan Tao, Ne-Taiwan

There is evidence of plankton mortality and extinction at various temporal and spatial scales induced by man-made pollution, or by natural causes (ageing, competition, predation, diseases, natural pollution). If mortalities take place at large scale they might become of environmental concern and may impact other biotic compartments including fisheries substantially. Such mortalities are a consistent phenomenon at time scales from geological mass extinctions to regularly occurring HABs, that appear to be increasing on a global basis. Several mass mortalities might have escaped our notice for their patchy and erratic occurrences. This also holds for mortalities caused by hydrothermal vents (HVs) that cover possibly more than 1.5% of the ocean floor. We studied zooplankton diversity, abundance and distribution patterns above shallow water hydrothermal vents at Kueishan Tao (Turtle Island), off the northeast coast of Taiwan (West Pacific). The HVs at this side provide an opportunity for the study of mortality, community and population effects of HV effluents with ecophysiological investigations that are otherwise difficult to perform at the more common HV environment, the deep sea. We found evidence for a bottle-neck situation for plankton above vent sites since holoplankton was generally deadly affected when immersed directly in vent plumes. Here we used copepods from HV sites for ecotoxicological testing in mesocosm field experiments.

Tafocenoses da Formação Pimenteira, Devoniano da Bacia do Parnaíba, Piauí: Mapeamento, Inventário e Relevância Patrimonial

During fieldwork conducted in the last ten years along the eastern border of the Parnaiba Basin in the State of Piaui, the continuous destruction of fossiliferous outcrops of the Pimenteira Formation has been observed and is clearly a matter of concern. In the current resumption of studies on this formation, the compilation of extensive inventories, covering all fossil groups, as well as the geological context, is a necessary means of protecting the geological heritage. The purpose of the present study is to establish the composition and mode of occurrence of the taphocoenoses and to evaluate the relative importance of the formation's numerous fossiliferous sites, thus contributing to their conservation. The inventory incorporates unpublished data obtained since 2005, information available in the literature, unpublished dissertations and theses, field notebooks, photographs from different periods, and records of Pimenteira Formation samples deposited in the scientific collections of various museums and universities. Since the pioneering work of Caster (1948), the taphocoenoses of the Pimenteira Formation have been characterized as of erratic occurrence and hosted mainly by sandstones. These initial interpretations have undergone significant changes following the 2009 excursion, which revealed new fossiliferous horizons and sites with an array of differing lithologies (siltstones, sandstones, and conglomerates). Based on this inventory, we consider the following to be the most significant outcrops: Morro Branco de Kegel; Rio Sambito; Morro do Cemiterio; BR-316/km 318; Itainopolis; Riachao; Sao Joao Vermelho; and PI-466/km 12. These sites are the most frequently mentioned in the literature and some have particular historical value and also considerable diversity of taphocoenoses that provide data about the depositional environment, genesis, and age of the fossiliferous deposits. Furthermore, the fossils are better preserved and record more comprehensively the faunal and floral variations of the Devonian seas and adjacent fluvio-deltaic environments.

Characterization of virulent gene locus in the genome of Fusarium spp. causing wilt disease of Psidium guajava L. in India

Wilt of Psidium guajava L., incited by Fusarium oxysporum f. sp. psidii and Fusarium solani is a serious soil borne disease of guava in India. Forty-two isolates, each of F. oxysporum f. sp. psidii (Fop) and F. solani (Fs), collected from different agro climatic zones of India showing pathogenicity were subjected to estimate their virulence factor in terms of analysis using virulent gene-related microsatellite loci. The erratic spread and occurrence of guava wilt in different areas may be due to variable aggressiveness or virulence of different pathogenic isolates in the soil. Out of 10 virulent gene locus related microsatellite markers ofFusarium spp., only six marker viz. Xyl, KHS1, PelA1, PG6/7, CHS1/2 and FMK1/MAPK1 were successfully amplified. This indicates that all the tested Fusarium sp. isolates of guava are having virulence gene in their genome. Microsatellite marker for virulence factor genes of Xyl loci was amplified in both Fop and Fs isolates. Product size of 281 bps was exactly amplified with a single banding pattern in all the isolates of Fop and Fs. It has been observed that other five microsatellite marker for virulence factor genes such as KHS1, PelA1, PG6/7, CHS1/2 and FMK1/MAPK1 were amplified with specific band pattern. PG6/7, CHS1/2 and FMK1/MAPK1 were only amplified in Fop isolates with a product size of 765 bps, 1566 bps; 1010 bps and 1244 bps. PelA1 and KHS1were amplified only in Fs isolates with the product size of 586 bps; 1359 bps, respectively. The results indicate that virulence factor genes are in response to produce wilt disease like symptoms in guava plants and also having pathogenic gene-related locus.