Mediterranean lichens in the tropics : lichens of the mist oasis of Erkwit, Sudan

From the mist oasis of Erkwit (Red Sea coastal plain of Sudan) 25 epiphytic lichen taxa are reported, probably the first lichen floristic report for the country. Most species encountered are widespread in warm and dry areas worldwide, while a few have their center in the Mediterranean region and document a Mediterranean element in this tropical region

Meloxicam and study of their antimicrobial effects against phyto- and human pathogens

Recently, the design of new biological metal-ligand complexes has gained a special interest all over the world. In this research, new series of mixed ligand complexes from meloxicam (H2mel) and glycine (Gly) were synthesized. Structures of the compounds were investigated employing elemental analyses, infrared, electronic absorption, 1H NMR, thermal analyses, effective magnetic moment and conductivity. The estimated molar conductivity of the compounds in 1*10-3 M DMF solution indicates the non-electrolyte existence of the examined complexes. Additionally, the effective magnetic moment values refer to the complexes found as octahedral molecular geometry. The data of the infrared spectra showed the chelation of H2mel and Gly with metal ions from amide oxygen and nitrogen of the thyizol groups of H2mel and through nitrogen of the amide group and oxygen of the carboxylic group for Gly. Thermal analyses indicated that the new complexes have good thermal stability and initially lose hydration water molecules followed by coordinated water molecules, Gly and H2mel. The kinetic parameters were calculated graphically using Coats-Redfern and Horowitz-Metzeger methods at n = 1 and n 6= 1. The density functional theory (DFT) calculations were performed at B3LYP levels. The optimized geometry of the ligand and its complexes were obtained based on the optimized structures. The data indicated that the complexes are soft with n value in the range 0.114 to 0.086, while n = 0.140 for free H2mel. The new prepared complexes were investigated as antibacterial and antifungal agents against some phyto- and human pathogens and the minimum inhibitory concentration (MIC) data showed that complex (A) has the lowest MIC for Listeria and E. coli (10.8 ug/mL)

Plant Essential Oil with Biological Activity

Plant essential oils (PEOs), extracted from many aromatic and medicinal plants, are used in folk medicine and often represent an important part of the traditional pharmacopoeia: they have a long history of use in folk medicine as antimicrobial agents to control several human and phyto-pathogens. Many PEOs have been registered as effective alternatives to chemical and synthetic antimicrobials, and in the last few decades, they have also been effectively used in the food industry as antioxidants and anticarcinogens, thanks to the efforts of many research/medical institutions and pharmaceutical companies. This Special Issue discussed the chemical composition and biological-pharmaceutical activities of some important PEOs and their single constituents. Detailed information has been also covered in this Special Issue regarding the mechanisms, possible modes of action, and factors affecting these activities, such as geographical origins, environmental conditions, nutritional status, and the extraction methods used

Sodium exchange in mouse and rat muscle

Imperial Users onl

Penetration Forces for Subsurface Regolith Probes

Investigating planetary bodies using penetrometers can provide detailed information about its history and evolution. An estimation of subsurface density and porosity can be made from the shape of the penetration curve. Using penetrometers mounted on planetary platforms could be challenging due to the uncertainty of the subsurface composition and since the maximum allowed force for penetration is the weight of the lander or rover on the surface. Estimation of penetration forces can provide a reliable constraint on the maximum reachable depth without endangering the whole mission. Therefore, knowledge of the required penetration force to specific depths can be helpful in designing the length and shape of the probe. Test probes covering the anticipated diameter (2.5, 1.9, 1.2 and 0.9 cm diameter) and tip angle (30°, 60°, 90°and 120°) were inserted mechanically into regolith analogs. The results showed that tip angle does not have a major effect, while probe diameter and density of the regolith are the most important parameters. Increasing probe diameter from 0.9 to 1.9 cm (i.e. a factor of 2) leads to an increase in penetration force from 200 to 1000 N (i.e. a factor of 5) at 20 cm depth. An increase in bulk density from 1550 to 1700 kg/m3 leads to an increase in penetration force from 10 to 200 N at 20 cm depth. Square probes required less force than circular ones which can allow for easier design of lateral windows

Subsurface Planetary Investigation Techniques and Their Role for Assessing Subsurface Planetary Composition

Subsurface planetary investigation techniques are of high interest and importance for the scientific community. Not only they can enhance our knowledge of the history of planetary formation but also can lead to information about its future. Whether the investigation is being conducted remotely using imagers, radars or physically using penetrometers or drills, a pre-existed knowledge of the mechanical and electrical properties of the subsurface regolith should be acquired for better data interpretation and analysis. Therefore, the main objective of this work is to investigate the mechanical and electrical properties of planetary analogs, understand their role for assessing the subsurface structure and identify their character for subsurface investigation techniques. Through-out this research, we investigated the mechanical and electrical properties of regolith analogs with emphasis on testing the feasibility of using penetrometer to explore the subsurface of planetary bodies and estimate their structure and layering. We found probe\u27s diameter and regolith density are the most dominant factors which affect penetration forces. We correlated the mechanical and electrical properties of regolith analogs to geomorphological shape formation. An increase in gully total length corresponds to an increase in dielectric constant, friction angle and formation bulk density which will enhance previous, current and future modelling, interpretation and analysis of optical imagery and radar data. We performed dielectric permittivity and hardness measurements for volcanic rocks in order to provide a cross relation between the dielectric constant of the investigated material and its hardness property. A linear increase in dielectric constant observed along with an increase in rock hardness. This will enhance characterization of the shallow subsurface when investigated using radar and drill/penetrometer

Body Size and Species Richness Changes in Glyptosaurinae (Squamata: Anguidae) Through Climatic Transitions of the North American Cenozoic

Poikilothermic vertebrates offer excellent climate proxies based on relationships between environment and measurable variables such as body size and species richness. Relationships of these variables in lizards to environmental transitions over long time scales are poorly understood. Here I show that patterns of body size and species richness in a lizard clade, Glyptosaurinae (Squamata: Anguidae), correspond to known histories of paleotemperatures through the Cenozoic of North America. Glyptosaurines have the richest fossil record among North American Cenozoic lizards and exhibit a wide range of skull sizes. In order to estimate body size for glyptosaurines and other fossil anguids, I collected skull and snout-vent length measurements of extant anguimorph lizards from museum collections, and used these data to model body size from skull length. I used my glyptosaurine body size estimates to calculate mean annual paleotemperatures (MAPT) for the interior of North America through the Paleogene. I also obtained anguid species richness data at NALMA temporal resolution from museum collections and literature. I compared these data to known Paleogene climate histories for the interior of North America using published MAPT proxies derived from terrestrial paleofloras and mammalian fossils. I found that maximum body size was comparable among the largest glyptosaurines from the early Eocene and the late Eocene, indicating paleotemperatures of about 19 – 20ºC during both intervals. Other terrestrial proxies indicated declines in continental MAPT of about 3 – 8ºC in the middle to late Eocene. This could indicate that overall temperature decreases remained above critical minimum temperatures for efficient metabolism in large lizards, or that some glyptosaurines behaviorally maintained body temperatures above cooler ambient levels in the late Eocene. Minimum MAPTs calculated using glyptosaurine body size estimates showed significant correlation with published continental MAPT proxies from other terrestrial indicators. I also found that glyptosaurine species richness peaked in the Wasatchian, followed by a decline through the remainder of the Paleogene; these patterns coarsely coincide with increases and decreases in continental MAPT. Adviser: Jason J. Hea

Rhizospheric Actinomycetes Revealed Antifungal and Plant-Growth-Promoting Activities under Controlled Environment

Actinomycetes has large habitats and can be isolated from terrestrial soil, rhizospheres of plant roots, and marine sediments. Actinomycetes produce several bioactive secondary metabolites with antibacterial, antifungal, and antiviral properties. In this study, some Actinomycetes strains were isolated from the rhizosphere zone of four different plant species: rosemary, acacia, strawberry, and olive. The antagonistic activity of all isolates was screened in vitro against Escherichia coli and Bacillus megaterium. Isolates with the strongest bioactivity potential were selected and molecularly identified as Streptomyces sp., Streptomyces atratus, and Arthrobacter humicola. The growth-promoting activity of the selected Actinomycetes isolates was in vivo evaluated on tomato plants and for disease control against Sclerotinia sclerotiorum. The results demonstrated that all bacterized plants with the studied Actinomycetes isolates were able to promote the tomato seedlings' growth, showing high values of ecophysiological parameters. In particular, the bacterized seedlings with Streptomyces sp. and A. humicola showed low disease incidence of S. sclerotiorum infection (0.3% and 0.2%, respectively), whereas those bacterized with S. atratus showed a moderate disease incidence (7.6%) compared with the positive control (36.8%). In addition, the ability of the studied Actinomycetes to produce extracellular hydrolytic enzymes was verified. The results showed that A. humicola was able to produce chitinase, glucanase, and protease, whereas Streptomyces sp. and S. atratus produced amylase and pectinase at high and moderate levels, respectively. This study highlights the value of the studied isolates in providing bioactive metabolites and extracellular hydrolytic enzymes, indicating their potential application as fungal-biocontrol agents