178 research outputs found
Biochemical Characterization, Antifungal Activity, and Relative Gene Expression of Two <i>Mentha</i> Essential Oils Controlling <i>Fusarium oxysporum</i>, the Causal Agent of <i>Lycopersicon esculentum</i> Root Rot
No full textTomato (Lycopersicon esculentum Mill.) is important food in daily human diets. Root rot disease by Fusarium oxysporum caused huge losses in tomato quality and yield annually. The extensive use of synthetic and chemical fungicides has environmental risks and health problems. Recent studies have pointed out the use of medicinal plant essential oils (EOs) and extracts for controlling fungal diseases. In the current research, Mentha spicata and Mentha longifolia EOs were used in different concentrations to control F. oxysporum. Many active compounds are present in these two EOs such as: thymol, adapic acid, menthol and menthyl acetate. These compounds possess antifungal effect through malformation and degradation of the fungal cell wall. The relative expression levels of distinctly upregulated defense-related WRKY genes (WRKY1, WRKY4, WRKY33 and WRKY53) in seedling root were evaluated as a plant-specific transcription factor (TF) group in different response pathways of abiotic stress. Results showed significant expression levels of WRKY, WRKY53, WRKY33, WRKY1 and WRKY4 genes. An upregulation was observed in defense-related genes such as chitinase and defensin in roots by application EOs under pathogen condition. In conclusion, M. spicata and M. longifolia EOs can be used effectively to control this plant pathogen as sustainable and eco-friendly botanical fungicides
Correction: Guidelines for the prevention, detection and management of the renal complications of COVID-19 in Africa
No full textThe authors of the article ‘Guidelines for the prevention, detection and management of the renal complications of COVID-19 in Africa’ [1] wish to acknowledge the contribution of Professor Hussein El Fishawy. Our guidelines drew on various sources, including the Egyptian Ministry of Health guidelines, portions of which were adapted and reproduced with permission from the Egyptian Ministry of Health. Two of the authors of those guidelines, Professors Elsayed and Zaki, are also coauthors of our paper. Professor El Fishawy was the third author of the Egyptian guidelines and we would like to acknowledge his contribution to our review through this source, especially with respect to the treatment algorithms for patients with kidney transplants and those with acute kidney injury. Reference1. Elsayed HM, Wadee S, Zaki MS, Were AJO, Ashuntantang GE, Bamgboye EL, et al. Guidelines for the prevention, detection and management of the renal complications of COVID-19 in Africa. Afr J Nephrol. 2020; 23(1):109-126
Bridging the gap between metropolitan Cairo and satellite cities : rethinking the expansion & urbanism of a dense city
No full textLAUREA MAGISTRALEIl Cairo è la capitale dell’Egitto situata vicino al delta del Nilo, il Cairo moderno fu fondato nel 969 d.C., ma la terra che componeva la città odierna era il sito di antiche capitali nazionali i cui resti rimangono visibili in alcune parti del Vecchio Cairo. Con una popolazione di 6,76 milioni distribuiti su 453 chilometri quadrati, Il Cairo è di gran lunga la città più grande dell’Egitto. Altri 10 milioni di abitanti vivono appena fuori città. Il Cairo, come molte altre megalopoli, soffre di alti livelli di inquinamento e traffico.
Oggi il Cairo è situato in tre dei distretti governativi dell’Egitto: la parte della sponda orientale è nel distretto di al-Qahira, la sponda occidentale di al-Giza, così come il governatorato di Qalyubiya a nord. La città sta lottando per far fronte ai problemi generati dalla massiccia crescita della popolazione, dall’espansione urbana incontrollata e dal deterioramento delle infrastrutture. Sebbene ricca di cultura e storia, la città rivela la crescente povertà dell’Egitto. Anche se il sito è stato abitato per oltre 6.000 anni ed è stato a lungo la capitale delle civiltà storiche egiziane come conseguenza dell’enorme densità di popolazione, le città satellite hanno iniziato a metastatizzare, le infrastrutture grigie hanno rovesciato i resti degli spazi urbani verdi, le aree agricole trasformate alle aree urbane, il deterioramento del vecchio Cairo storico e del suo tessuto urbano, il netto distacco dal tessuto della città vecchia e del nuovo Cairo e l’elevata densità di popolazione all’interno del Cairo storico portano le persone ad abbandonare le loro vecchie case per una migliore qualità della vita verso nuove città satellite , lasciandosi alle spalle la loro vecchia storia di vita senza cercare di salvarla.
La crescita urbana al Cairo è definita dall’infrastruttura tra città metropolitana e città satellite, di conseguenza, abbiamo concluso che possiamo classificare i tipi di città in; Vecchio Cairo storico, Nuovo Cairo (città satellite) e aree deserte (città gialla). Colmare il divario tra il Cairo metropolitano e le città satellite avverrà in più fasi, concentrandosi prima sui problemi della città metropolitana, su come risolvere i problemi all’interno della città per restituire alle persone il senso di appartenenza piuttosto che incoraggiarle a lasciare la propria posto. In secondo luogo, poiché l’Egitto possiede un’abbondanza di terra, clima soleggiato e velocità del vento elevate, il che lo rende un luogo privilegiato per progetti di energia rinnovabile, utilizzando l’enorme area vuota e deserta tra le città sia per soddisfare la crescente domanda, sia per passare a un ambiente più ecologico settore elettrico sostenibile e diversificato. Le Città Satellite, infine, sono un settore di classe superiore, in grado di mettere in moto l’idea di mobilità dolce, spazi verdi aperti e parchi pubblici in considerazione del fatto che tradizionalmente e culturalmente non è una comune strategia sociale.
I nostri due approcci principali sono; Approccio urbano che offre alla sua popolazione un ambiente urbano adeguato, occupazione, cibo, alloggio e trasporti senza compromettere il benessere della futura popolazione di quella città e come possiamo ripristinare le risorse e l’eredità del vecchio Cairo. Inoltre, il mantenimento dell’equità sociale tra il Cairo metropolitano e le città satelliti implica una giusta ed equa distribuzione delle risorse tra l’attuale generazione senza concentrarsi sul nuovo e dimenticare il Vecchio. In termini di ambiente urbano, la città dovrebbe fornire un luogo di pari opportunità e non essere un agente di segregazione. Approccio ecologico su come è richiesta la responsabilità spaziale, il che significa che la città ha una “impronta” che è considerevolmente più grande dell’area che occupa, a significare che sistemi come; il sistema verde, il sistema grigio e il sistema edilizio non sono distribuiti equamente, quindi creando un sistema che si metastatizza dall’interno della città alla gonna esterna fino a quando l’approccio soddisfa adeguatamente le esigenze dei 3 sistemi, quindi sarebbe replicato sul resto del Cairo la zona.Cairo is the capital of Egypt located near the Nile Delta, modern Cairo was founded in 969 CE, but the land composing the present-day city was the site of ancient national capitals whose remnants remain visible in parts of Old Cairo. With a population of 6.76 million spread over 453 square kilometers, Cairo is by far the largest city in Egypt. An additional 10 million inhabitants live just outside the city. Cairo, like many other mega-cities, suffers from high levels of pollution and traffic.
Today Cairo is situated in three of Egypt’s governing districts: the east bank portion is in al-Qahira district, the west bank in al-Giza, as well as the Qalyubiya governorate to the north. The city is struggling to cope with the problems generated by massive population growth, urban sprawl, and a deteriorating infrastructure. Though rich in culture and history, the city reveals Egypt’s growing poverty. Even though the site has been settled for over 6,000 years, and long served as the capital of historic Egyptian civilizations as a consequences of the massive population density, satellite cities started metastasizing, gray infrastructure overthrew the remains of the green urban spaces, agriculture areas transformed to urban areas, the deterioration of historical old Cairo and its urban fabric, the clear detachment old city fabric and the new Cairo and the high population density inside the historical Cairo lead people to abandoned their old houses for better quality of life to new satellite cities, leaving their old life story behind them without trying to save it.
Urban growth in Cairo is defined by the infrastructure between metropolitan city and satellite cities, in result of that, we concluded that we can classify the types of cities into; Old historical Cairo, New Cairo (satellite cities) and deserted areas (yellow city). Bridging the gap between Metropolitan Cairo and satellite cities will happen in several phases, first focusing on the problems in the metropolitan city, how can we solve the issues within the city to restore to the people the sense of belonging rather than encouraging them to leave their place. Secondly, since Egypt possesses an abundance of land, sunny weather, and high wind speeds, making it a prime location for renewable energy projects, utilizing the huge empty deserted area between the cities to both address increasing demand, and to move to a more environmentally sustainable and diverse electricity sector. Lastly, Satellite cities are more high class sector with the ability to set in motion the idea of soft mobility, open green spaces and public parks in view of the fact that traditionally and culturally its not a common social strategy.
Our two main approaches are; Urban approach offering to its population a suitable urban environment, employment, food, housing and transportation without compromising the welfare of the future population of that city and how can we restore the resources and legacy of Old Cairo. In addition, maintaining the social equity between Metropolitan Cairo and satellite cities the Implies a fair and equitable distribution of resources among the current generation without focusing on the new and forgetting the Old. In terms of the urban environment, the city should provide a place of equal opportunity and not be an agent of segregation. Ecological approach on how spatial responsibility is required which means that the city has a “footprint” that is considerably larger than the area it occupies signifying that the systems such as; green system, gray system and building system are not distributed equally, So creating a system that metastasize from inside the city to the outer skirt till the approach are adequately fulfilling the needs of the 3 systems, so it would be replicated on the rest of Cairo’s area
Developing and testing guidelines for designing surprising products
No full textLAUREA MAGISTRALELa sorpresa è diventata un argomento interessante nel mondo del design di prodotto; è stato dimostrato che la presenza di un elemento sorprendente all'interno di un prodotto aumenta l'interazione uomo-prodotto e l’apprezzamento in generale. Sono stati compiuti sforzi attraverso numerosi studi per capire cosa sia veramente il concetto di sorpresa e su cosa si basa, cosa rende sorprendenti alcuni prodotti e come si possono catturare i processi cognitivi coinvolti quando un utente valuta un oggetto probabilmente sorprendente. Tuttavia, mancava ancora una linea guida che permettesse a ingegneri meccanici e designer di esplorare sistematicamente la propria creatività per generare, infine, idee per prodotti sorprendenti. L'autore di questa tesi di laurea magistrale ha proposto delle linee guida per questo scopo, che vengono proposte attraverso una presentazione interattiva. Questa presentazione interattiva è stata testata per la sua usabilità come strumento metodologico da un set di ingegneri meccanici e designer industriali, ritenuti i destinatari delle linee guida. Inoltre, le sorpresa indotta dalle idee generate da detti ingegneri e designer è stata valutata da un insieme di partecipanti accuratamente filtrati. I risultati raggiunti durante entrambe le attività sperimentali hanno raggiunto gli obiettivi fissati e consentono alle linee guida proposte di fungere da solida base per ulteriori sviluppi, sulla base dei miglioramenti già ipotizzati dall'autore sia per incrementare l’efficacia delle linee guida proposte che la relativa procedura di verifica.Surprise has become an interesting topic in the world of product design; the presence of a surprising trigger within a product has been proved to increase human-product interaction and overall likeability. Efforts by numerous contributors have been made to understand what the concept of surprise truly is and what does it rely on, what makes some products surprising, and how can one capture the cognitive processes involved when a user assesses an arguably surprising object; however, there was yet to be a guideline, using which mechanical engineers and designers can systematically explore their own unique creativity to ultimately generate ideas for surprising products. The author of this master thesis has proposed guidelines that do exactly that in the form of an interactive presentation. This interactive presentation was tested for its usability as a methodological tool by a third party of mechanical engineers and industrial designers. Furthermore, the ideas generated by those said engineers and designers have been assessed whether if they are genuinely surprising or not by a set of carefully filtered participants. The results reached during both external tests met expectations and allow the proposed guidelines to serve as a firm base for further development; however, the author acknowledges some points where potential improvements are due in both the proposed guidelines and in the testing procedure
Activation Energy of Surface Diffusion and Terrace Width Dynamics During the Growth of in (4×3) on Si (100) - (2×1) by Femtosecond Pulsed Laser Deposition
No full textThe nucleation and growth of indium on a vicinal Si (100) - (2×1) surface at high temperature by femtosecond pulsed laser deposition was investigated by in situ reflection high energy electron diffraction (RHEED). RHEED intensity relaxation was observed for the first ∼2 ML during the growth of In (4×3) by step flow. From the temperature dependence of the rate of relaxation, an activation energy of 1.4±0.2 eV of surface diffusion was determined. The results indicate that indium small clusters diffused to terrace step edges with a diffusion frequency constant of (1.0±0.1) × 1011 s-1. The RHEED specular beam split peak spacing, which is characteristic of a vicinal surface, was analyzed with the growth temperature to obtain the average terrace width. Gradual reduction in the terrace width during growth of In (4×3) was observed with In coverage and is attributed to the detachment of In atoms from terrace edges. At a substrate temperature of 405 °C, the average terrace width decreased from 61±10 Å, which corresponds to the vicinal Si(100) surface, to an equilibrium value of 45±7 Å after deposition of ∼23 ML. Further In coverage showed a transition of the RHEED pattern from (4×3) to (1×1) and the growth of rounded In islands (average height of ∼1 nm and width of ∼25 nm), as examined by ex situ atomic force microscopy. © 2008 American Institute of Physics. [DOI: 10.1063/1.2909923
Low-temperature growth of InN on Si(100) by femtosecond pulsed laser deposition
No full textInN films were grown on Si(100) using femtosecond pulsed laser deposition. Laser induced breakdown of ammonia was used to generate atomic nitrogen for InN growth. An indium buffer layer was initially deposited on the Si substrate at low temperature followed by an InN intermediate layer. The crystal quality and surface morphology were investigated by reflection high-energy electron diffraction during growth and atomic force microscopy and x-ray diffraction after growth. The results showed that the In (2×1) initial buffer layer improved the quality of the InN film. High quality InN films were grown at a temperature of ∼350 °C
Differential expression of cytochrome oxidase and ALY-family genes in resistant and susceptible tomato cultivars (Solanum lycopersicum) inoculated with Tomato bushy stunt virus
No full textAbstractTomato cultivars (TY20, TY70/84 and TY70/70) were mechanically inoculated with purified virus preparations of Tomato bushy stunt virus (TBSV). Inoculated plant tissues were collected after 1day, 1week and 2weeks post-inoculation. Messenger RNA of the inoculated and healthy plants was scanned using the differential display to discover the up- and down-regulated genes induced or suppressed in the infected plants. Three down-regulated and four up-regulated genes were observed in different molecular weights. Sequence analysis revealed that the 400bp up-regulated gene of cultivars TY70/84 and TY70/70 was cytochrome oxidase gene. Expression of these genes was higher in the two resistant cultivars more than the control and the susceptible one (TY20). The other four genes belong to the ALY-gene family which possibly function as a chaperone to promote the interaction of DNA-binding proteins
Formation of In- (2×1) and in Islands on Si (100) - (2×1) by Femtosecond Pulsed Laser Deposition
No full textThe growth of indium on a vicinal Si (100) - (2×1) surface at room temperature by femtosecond pulsed laser deposition (fsPLD) was investigated by in situ reflection high-energy electron diffraction (RHEED). Recovery of the RHEED intensity was observed between laser pulses and when the growth was terminated. The surface diffusion coefficient of deposited In on initial two-dimensional (2D) In- (2×1) layer was determined. As growth proceeds, three-dimensional In islands grew on the 2D In- (2×1) layer. The RHEED specular profile was analyzed during film growth, while the grown In islands were examined by ex situ atomic force microscopy. The full width at half maximum of the specular peak decreased during the deposition, indicative of well-ordered growth and an increase of the island size. The In islands developed into elongated-polyhedral, circular, and triangular shapes. The elongated and triangular islands were highly oriented, parallel and perpendicular to the surface terrace edges, while the circular islands show a top flat surface. Deposition of In on Si (100) - (2×1) by fsPLD influenced the formation of the initial In- (2×1) layer and the morphology of the grown islands. © 2007 American Institute of Physics. [DOI: 10.1063/1.2738388
Atomic Hydrogen Cleaning of InP(100): Electron Yield and Surface Morphology of Negative Electron Affinity Activated Surfaces
No full textAtomic hydrogen cleaning of the InP(100) surface has been investigated using quantitative reflection high-energy electron diffraction. The quantum efficiency of the surface when activated to negative electron affinity was correlated with surface morphology. The electron diffraction patterns showed that hydrogen cleaning is effective in removing surface contaminants, leaving a clean, ordered, and (2×4)-reconstructed surface. After activation to negative electron affinity, a quantum efficiency of ∼6% was produced in response to photoactivation at 632 nm. Secondary electron emission from the hydrogen-cleaned InP(100)-(2×4) surface was measured and correlated to the quantum efficiency. The morphology of the vicinal InP(100) surface was investigated using electron diffraction. The average terrace width and adatom-vacancy density were measured from the (00) specular beam at the out-of-phase condition. With hydrogen cleaning time, there was some reduction in the average terrace width. The surface quality was improved with hydrogen cleaning, as indicated by the increased (00) spot intensity-to-background ratio at the out-of-phase condition, and improved quantum efficiency after activation to negative electron affinity. © 2002 American Institute of Physics. [DOI: 10.1063/1.1429796
Structural, Optical, and Gamma Shielding Performance of Arsenic-Doped Borate Glasses
No full textArsenic-doped borate glasses [xAs₂O₃ – (60−x)B₂O₃ – 20BaO – 20K₂O; x = 0–10 mol%] were synthesized by melt-quenching and investigated for structural, optical, and gamma shielding properties. XRD and FTIR confirmed amorphous networks with BO₃/BO₄ and AsO₄ units, while increasing As₂O₃ raised density (2.94–3.20 g/cm³) and reduced the optical band gap (3.32–1.49 eV). Gamma attenuation analysis showed improved shielding with higher As content, reflected in greater mass attenuation coefficients, effective atomic numbers, and reduced HVL and MFP. Distinct EBF peaks near arsenic and barium K-edges confirmed enhanced low-energy photon interactions. Compared with concretes, the glasses exhibited superior shielding while retaining optical transparency, demonstrating their potential as multifunctional radiation-protective materials
- …
