Gene regulation in methanotrophs : evidence from Methylococcus capsulatus (Bath) and Methylosinus trichosporium (OB3b)

Methylococcus capsulatus (Bath) is a Gram-negative, spherical-shaped bacterium that gains its needs of carbon and energy via oxidation of methane, a potent greenhouse gas, thus alleviating global warming. This bacterium oxidises methane to methanol using a membrane-bound particulate methane monooxygenase (pMMO) or a soluble, cytoplasmic methane monooxygenases (sMMO). Copper-tobiomass- ratios significantly affect the expression and activity of both enzymes; the biosynthesis of sMMO is switched on when copper-to-biomass ratios are low, while pMMO is up-regulated when they are high. The exact mechanisms by which copper regulates the switching between sMMO and pMMO are not fully elucidated. Therefore, the main aim of this study was to shed some light on this copper switch, taking the advantage of the availability of the genome sequence of this organism, together with mutagenesis and transcriptional regulation studies. Three potential copper transport Mc. capsulatus mutants; ΔcopA1, ΔcopA2 and ΔcopA3 were generated. The genes inactivated encode three different P-type ATPase homologs.This revealed that CopA1, CopA2 and CopA3 have roles in copper homeostasis, although disruption of genes encoding these proteins individually did not result in constitutive sMMO expression. In addition, three mutants; ΔnrpS-1, ΔnrpS-2 and pkS were constructed. pkS encodes for a polyketide synthase, nrpS-1 and nrpS-2 encode for two non-ribosomal peptide synthetases. The products of these genes were proposed to be involved in biosynthesis of methanobactin, a short peptide that scavenges copper when it is limited. Results suggested that nrpS-2 and pkS might be involved in production of a functional methanobactin. Putative coding sequences predicted to be involved in methanobactin biosynthesis in another methane-oxidising bacterium, Methylosinus trichosporium (OB3b), were also mutated. The mutant was unable to produce methanobactin, could not express sMMO, and was copper resistant compared to the wild-type organism. Therefore, methanobactin is ribosomally- produced in Ms. trichosporium. Corresponding genes were not identified in the genome of Mc. capsulatus. A microarray-based comparative expression profiling study of whole-genome transcriptomics of Mc. capsulatus expressing sMMO versus pMMO was carried out to identify genes involved in regulation of MMO by copper. This identified 53 genes that were differentially expressed and hence promising candidate genes for future studies of MMO regulation. For example, tetR, a down-regulated gene, encodes a putative transcriptional regulator and tonB, an up-regulated gene, which encodes a protein that is a part of a membrane transporter. Interestingly, a cluster of six genes 5’ of sMMO was up-regulated; five of them were found to be co-transcribed. A mutant was made in an up-regulated gene encoding ScO protein (synthesis of cytochrome c). The mutant could tolerate high concentrations of copper compared to the wild-type strain. The work presented in this study is considered a step forward towards understanding the regulatory mechanisms of the copper switch in methanotrophs and provided the basis for new lines of future research to fully understand this phenomenon

Rural Information Portal

Growth in information and communication technologies, and specifically the internet, has the potential to offer a new generation of tools for rural development. The internet, with its huge quantities and variety of content, is increasingly becoming an effective delivery and exchange system for information and knowledge, continuing education and learning. However, rural information and communication technology (ICT) requires special efforts to create appropriate access to the required information by the rural people and communities

Design Optimization of Semi Rigid Steel Framed Structures to AISC- LRFD Using Harmony Search Algorithm

The aim of this research is to develop a computer design model which obtains the optimum design of multistorey steel frames by selecting from a standard set of steel sections. Strength constraints of American Institute Steel Construction (AISC)-Load and Resistance Factor Design (LRFD) specification, displacement constraints and size constraint for beam-columns were imposed on frames. Harmony search (HS) is a recently developed metaheuristic search algorithm that was conceptualized using the musical process of searching for a perfect state of harmony. The harmony in music is analogous to the optimization solution vector, and the musician’s improvisations are analogous to local and global search schemes in optimization techniques. The HS algorithm does not require initial values for the decision variables. Furthermore, instead of a gradient search, the HS algorithm uses a stochastic random search that is based on the harmony memory considering rate and the pitch adjusting rate so that derivative information is unnecessary. The HS algorithm accounts for the effect of the flexibility of the connections and the geometric non-linearity of the members. The semi-rigid connections are modelled with the Frye–Morris polynomial model. Moreover, two steel frames with extended end plate without column stiffeners are designed using HS algorithm. Full Catalog Section (FCS) and Selected Catalog Section (SCS) are used to compare the obtained results. The results prove that harmony search algorithm is a powerful and effective tools, in comparison with genetic algorithm. Also the comparisons showed that the harmony search algorithm yielded lighter frame in case of rigid and semi-rigid connections for the presented models. In addition, using the Selected Catalog Sections the optimum frames are lighter than that of the Full Catalog Sections. Moreover, HS converges to optimum designs before the maximum numbers of iterations executed in almost designs

COMPARATIVE STUDY BETWEEN PERIOSTIN AND OSTEOCALCIN AS BIOMARKERS FOR OSTEOPOROSIS AND FRACTURE RISK IN EGYPTIAN POSTMENOPAUSAL WOMEN

Objective: This study aimed to compare between periostin and osteocalcin as biomarkers in Egyptian postmenopausal women with osteoporosis and to explore their possible relationship with fracture risk. Methods: This study included 90 postmenopausal females recruited from Al-Hussein University Hospital, Cairo, Egypt; divided into three groups; 35 postmenopausal osteoporotic females with low fracture risk (group I), 35 postmenopausal osteoporotic females with high fracture risk (group II), and 20 apparently healthy controls. Serum periostin, osteocalcin, and estrogen were measured by Enzyme Linked Immunosorbent Assay (ELISA). Fracture risk assessment was calculated. Alkaline phosphatase (ALP), total and ionized calcium, Aspartate transaminase (AST), and Alanine transaminase (ALT) were measured spectrophotometrically. Results: The diagnostic performance of periostin for discriminating high fracture risk from low fracture risk groups showed the specificity of (68.6 %) and sensitivity of (100 %), while for osteocalcin the specificity was (51.4 %) and the sensitivity was (68.6 %) respectively. Moreover, the multi Receiver Operating Characteristics (multi-ROC) curve for periostin and osteocalcin together revealed improved specificity and sensitivity of (100 %) each. Conclusion: Periostin was superior to osteocalcin in discriminating high fracture risk from low fracture risk postmenopausal osteoporotic groups. Moreover, dual use of both markers gave the highest discriminative power between low and high fracture risk groups with 100 % specificity and sensitivity

Oral health-related interdisciplinary practices among healthcare professionals in Saudi Arabia: Does integrated care exist?

Background There is a bidirectional relation between oral and general health, therefore collaboration between healthcare providers is needed. This study investigated current interdisciplinary practices (IDP) and the associated factors among healthcare professionals in Saudi Arabia. Methods A cross-sectional study was conducted in the Eastern Saudi Arabia recruiting four groups of health professionals (nurses, physicians, pediatricians and Ear-Nose and Throat (ENT) specialists). A validated, self-administered questionnaire was distributed online and shared through social media platforms. The questionnaire explored predisposing factors (demographics) and facilitating factors (knowledge, attitudes, attendance of oral health training and source of knowledge) associated with IDP. Results A total of 1398 health professionals were recruited. Participants showed fair oral health knowledge (7.1 ± 2.1) and attitudes (22.2 ± 3). Three-fourths (74.6%) reported always providing oral health education (OHE) to their patients, more than half (59.6%) reported always conducting an oral health screening (OHS), two-thirds (66.7%) reported responding to patients’ questions about oral health or conditions and 58.7% reported referring patients to dentists. Pediatricians and physicians had greater odds of IDP compared to other health professionals. Source of oral health knowledge (Ministry of Health (MOH) and formal education) was significantly associated with increased odds of IDP. Participants with good oral health knowledge had greater odds of responding to patients’ oral health question as well as have more referral practices. Conclusion The results reveal a discrepancy between participants' IDP, knowledge, and attitudes. Incorporating dental component to medical curricula, continuous education and training programs targeting health professionals through Ministry of Health should be considered.publishedVersio

Ultrastructure of antennal sensillae of the samsum ant, Pachycondyla sennaarensis (Hymenoptera: Formicidae)

Black ant (Samsum), Pachycodyla sennarrensis, stings and injects venom and inflicts allergy (a rare clinical problem) due to its local and systemic reaction, which is considered as a health hazard amongst Saudi society. Thus, black ant is a source of serious concern for the government and experts as well.  Ultramorphological variations, distribution, differential sensillae counts (DSC) and total sensillae counts (TSC), were identified and estimated as a complementary part of the peripheral nervous system on the antennae of worker samsum ant, P. sennarrensis in order to understand its behavioral ecology. Based on scanning electron micrographs, four types of sensillae constituted with three trichoid types, which is an abundant form with a high distribution density at the apex, but a low density at subsequent proximal flagellomere of the antenna and a placoid type of sensillae (a rare form mostly found in the middle of the flagellum, that is, on the 4th, 5th and 6th flagellomere) were categorised. It is documented that nonporous trichoid type of sensillae are mechanoreceptors and thermoreceptors, whereas, the placoid types are olfactory receptors. Present findings in an indigenous species in Saudi Arabia may help in understanding the ecological behaviour of the ant, which subsequently may form the basis in producing its effective control measure in future.Key words: Samsum ants, Pachycondyla sennarrensis, ultrastructure, antenna, sensillae

Using Rainfall Simulators to Design and Assess the Post-Mining Erosional Stability

The mining industry is crucial for global economic growth but faces environmental challenges, especially in designing stable rehabilitated landforms. To tackle these issues, rainfall simulators have been recognized for their value in providing data for erosion modeling and analysis, aiding the development of effective land cover systems for long-term stability. This chapter provides an overview of the theory, specifications, and design principles of rainfall simulators. It explores the detailed design and construction of a well-known model, along with its calibration process ensuring accurate rainfall production and distribution. The chapter also discusses raindrop size distribution and associated kinetic energy calculations. Calibration results demonstrate satisfactory outcomes with Christiansen’s uniformity coefficient exceeding 85% and a median raindrop size of 2.15 mm. The device successfully generates desired kinetic energy for simulated rainstorms, crucial for studying soil erosion. Examples highlight the application of rainfall simulators in evaluating erosion stability in Queensland mines. Efforts to construct a soil erosion database for 34 open-cut mines in Queensland using a similar portable rainfall simulator are highlighted. This database contributes to developing user-friendly MINErosion models, providing estimates of soil erosion/deposition at different scales to support the Australian mining sector

Design Optimization of Semi-Rigidly Connected Steel Frames Using Harmony Search Algorithm

In this paper, a design optimization algorithm is presented for non-linear steel frames with semi-rigid beamcolumnconnections using harmony search algorithm. The design algorithm obtains the minimum steel weight by selecting from a standard set of steel sections. Strength constraints of American Institute of Steel Construction - Load and Resistance Factor Design (AISC-LRFD) specification, displacement, deflection, size constraint and lateral torsional bulking are imposed on frames. Harmony search (HS) is a recently developed meta-heuristic search algorithm which is based on the analogy between the natural musical performance and searching the solutions to optimization problems. The HS algorithm accounts for the effect of connections’ flexibility and the geometric non-linearity of the members. The Frye–Morris polynomial model is used for modeling semi-rigid connections. Two design examples with extended end plate without column stiffeners are presented to demonstrate the application and validity of the algorithm

Samsum ant, Brachyponera sennaarensis (Formicidae: Ponerinae): Distribution and abundance in Saudi Arabia

AbstractInvasive species are capable of causing considerable damage to natural ecosystems, agriculture and economies throughout the World. Samsum ant, Brachyponera (Pachycondyla) sennaarensis has been a reason for medical implication and social nuisance through its poisonous and severely painful sting causing anaphylactic shock in many cases. We surveyed for the presence of the samsum ant in various provinces of Saudi Arabia. B. sennaarensis was the abundant Ponerinae species in human settlements. In the Eastern provinces, however, few samples were collected, and none were found in the Northern and Western provinces. Infestations of B. sennaarensis were particularly severe in the spring and summer seasons, when the ants make nests in moist areas and in cracks in cemented structures, whereas the extent of infestation reduced in winter seasons