Weed vegetation ecology of arable land in Salalah, Southern Oman

AbstractThis paper applies multivariate statistical methods to a data set of weed relevés from arable fields in two different habitat types of coastal and mountainous escarpments in Southern Oman. The objectives were to test the effect of environmental gradients, crop plants and time on weed species composition, to rank the importance of these particular factors, and to describe the patterns of species composition and diversity associated with these factors. Through the application of TWINSPAN, DCA and CCA programs on data relating to 102 species recorded in 28 plots and farms distributed in the study area, six plant communities were identified: I- Dichanthium micranthum, II- Cynodon dactylon–D. micranthum, III- Convolvulus arvensis, IV- C. dactylon–Sonchus oleraceus, V- Amaranthus viridis and VI- Suaeda aegyptiaca–Achyranthes aspera. The ordination process (CCA) provided a sequence of plant communities and species diversity that correlated with some anthropogenic factors, physiographic variables and crop types. Therefore, length of time since farm construction, disturbance levels and altitude are the most important factors related to the occurrence of the species. The perennial species correlated with the more degraded mountain areas of new farm stands, whereas most of the annuals correlated with old lowland and less disturbed farms

Population structure of woody plants in the arid cloud forests of Dhofar, southern Oman

This study evaluates the size frequency distribution of 11 trees and shrubs in the cloud forest in Wadi Garziz, southern Oman, in order to assess their current situation, which is affected by cutting, overgrazing and other constraints. A size class distribution and a vegetation structure analysis were applied in order to analyze the dynamics of this forest using census data from 51 plots selected across 5 transects covering the hill-slope andwadi-bed habitats. Some of the trees inhabiting the hill-slopes (e.g. Acacia senegal and Commiphora spp.) were found to exhibit an inverse J-shaped distribution with constant regeneration, whilst in the wadi bed these same trees exhibited a J-shaped distribution (i.e. of declining populations). On the other hand, Acacia etbaica inhabiting the hill- slopes exhibited a tendency towards a J-shaped distribution and an inverse J-shaped distribution in the wadi-bed. All the populations (i.e. inhabiting the hill-slopes and the beds) of Anogeissus dhofarica had a J-shaped distribution whereas all the populations of Blepharispermum hirtum had a more or less inverse J-shaped distribution. The Ziziphus spina-christi and Acacia tortilis populations, meanwhile, exhibited the bi-modal shape of size distribution. The shrubs inhabiting the hill-slopes (e.g. Coroton confertus and Ormocarpum dhofarense) exhibited a tendency towards a J-shaped distribution; such distribution characterizes a declining population with a limited regenerational capacity. Overall, most of the examined populations, except those of Acacia etbaica in wadi-bed and Blepharispermum hirtum, seemed to be under stress from both environmental and human factors, particularly in the wadi bed. This type of study can provide a basis for the development of a management plan to support the conservation and sustainable use of forest vegetation in an arid region

Calibration Estimation for Ratio Estimators in Stratified Sampling for Proportion Allocation

Calibration has established itself as an important methodological instrument in large scale production of statistics. In this paper, we propose calibration estimation for ratio estimator in stratified sampling and derive the estimator of the variance of the calibration estimation ratio estimator in stratified sampling in case proportion allocation

Evaluation of the effects of conservation tillage on field crops productivity and profitability in the Gezira Scheme, Sudan

   A permanent experimental site at Gezira Research Station Farm was chosen for five consecutive years (2004/05 to 2008/09), to represent the Gezira Scheme crops rotational serial, which is cotton, wheat, groundnut, sorghum and fallow. The objective was to evaluate the effects of conservation tillage (continuous reridging) on crop productivity and profitability compared to conventional tillage practices for each crop. Each crop was sown with the use of the two tillage systems of land preparation with three replicates. Crops were manually sown using the recommended seed rate, where wheat sowing was done on the top of 80-cm beds in three rows 15-cm apart. The soil bulk density and the corresponding soil moisture content were determined for each crop after the first irrigation(at seedling stage) and at flowering stage at three soil depths. The results indicated no significant differences between the two tillage systems for all crops measured traits. Conservation tillage was found to reduce the cost of production of all the rotational crops in comparison with conventional practices. Accordingly, conservation tillage could be adopted for field crops production in the irrigated schemes located in the Sudan clay plains, provided that the fields are free from perennial weeds and not compacted. تم اختيار موقع دائم في مزرعة محطة بحوث الجزيرة لمدة خمسة سنوات متتالية (2004/05 إلى 2008/09)، وذلك لتمثيل مسلسل الدورة الزراعية للمحاصيل بمشروع الجزيرة، وهو القطن، القمح، الفول السوداني، الذرة والبور. كانت الأهداف لتقييم آثار الحراثة الحافظة(فتح السراب المستمر) على إنتاجية وربحية المحصول بالمقارنة مع عملية الحراثة السائدة لكل محصول. تمت زراعة كل محصول باستخدام نظامي الحراثة لتحضير الأرض بثلاثة مكررات. كان حجم المربع المزروع 10م×10 م، والمساحة المحصودة 3.2م×5م (4 صفوف×5م). تمت زراعة المحاصيل بمعدل كمية التقاوي الموصي بها يدوياً. وقد تم بذر القمح على قمة مساطب 80 سم بتأسيس ثلاثة صفوف على بعد 15 سم من بعضها البعض. تم تحديد الكثافة الظاهرية للتربة ومحتوى الرطوبة المقابل لها لكل محصول بعد الرية الأولى و في مرحلة الإزهار. أوضحت النتائج عدم وجود فروقات معنوية بين نظامي الحراثة بالنسبة لكل الصفات المقاسة لجميع المحاصيل. كما وجد أن الحراثة الحافظة قد قللت تكلفة الإنتاج مع توفير كبير في تكلفة نظام الحراثة للهكتار بالمقارنة مع ممارسة الحراثة السائدة لكل محاصيل الدورة. وعليه، فيمكن تبني الحراثة الحافظة (فتح السراب المستمر) لإنتاج المحاصيل الحقلية بالمشاريع المروية التي تقع في سهول السودان الطينية، شريطة أن تكون الحقول خالية من الحشائش المعمرة وغير متصلبة

GASTRO-PROTECTION OF ATORVASTATIN IN INDOMETHACIN-INDUCED ULCER: ROLE OF TUMOR NECROSIS FACTOR-ALPHA AND PROSTAGLANDINS

Using non-steroidal anti-inflammatory drugs as over-the-counter pain-killers may predispose to gastric ulcer as a side effect.The objective of this study is to investigate the possible benefit of a common statin used in hyperlipedemic patients;atorvastatin (AtoR), in ameliorating the ulcerogenic effect of indomethacin (IndoM), and to explore the possible mechanismsinvolved. AtoR (10 mg/kg/day) was administered orally for 7 days. At day 7, gastric ulcer was induced by a single dose ofIndoM (40 mg/kg i.p.), with or without AtoR pre-treatment. IndoM induced gastric ulcer as evident by notable gastriculceration in histopathological sections compared to normal control. Gastric tissue in rats receiving IndoM showedsignificantly higher oxidative stress markers as lipid peroxidation represented by increased malondialdehyde (MDA)content, with significant decrease in gastric tissue nitric oxide (NO) and prostaglandin E2 (PGE2) levels, as well as reductionin catalase and superoxide dismutase antioxidant enzymatic activities. In addition, IndoM induced inflammatory signs asshown by the significant increase in tumor necrosis factor-alpha (TNF-α) level assessed via ELISA. Pre-administration ofAtoR significantly decreased ulcer index (16±1) compared to that of IndoM alone (34±2). In addition, AtoR restored normalgastric histological structure and reverted oxidative and inflammatory markers tested. AtoR confers gastro-protection againstIndoM-induced ulceration via reducing gastric oxidative stress and increasing gastric NO and PGE2 levels, as well asdecreasing the inflammatory marker; TNF-α

Antioxidant activity and mineral composition of three Mediterranean common seaweeds from Abu-Qir Bay, Egypt

AbstractAntioxidant activity and mineral composition were evaluated seasonally from spring to autumn 2010 in the three common seaweeds Ulva lactuca Linnaeus (Chlorophyta), Jania rubens (Linnaeus) J.V. Lamouroux and Pterocladia capillacea (S.G. Gmelin) Bornet (Rhodophyta). The antioxidant activity was measured with β-carotene, total phenol content and DPPH (2,2-diphenyl-1-picrylhydrazyl). Seaweeds were collected from the rocky site near Boughaz El-Maadya Abu-Qir Bay of Alexandria, Egypt. The results showed maximum increase of β-carotene in P. capillacea during summer. A significant increase in total phenolic content at P⩽0.05 was found in the red alga (J. rubens) during summer. Also, U. lactuca showed the maximum antioxidant scavenging activity especially during summer. Minerals in all investigated samples were higher than those in conventional edible vegetables. Na/K ratio ranged between 0.78 and 2.4mg/100g, which is a favorable value. All trace metals exceeded the recommended doses by Reference Nutrient Intake (RNI). During summer season, it was found that Cu=2.02±0.13 and Cr=0.46±0.14mg/100g in U. lactuca and Fe had a suitable concentration (18.37±0.5mg/100g) in P. capillacea. The studied species were rich in carotenoids, phenolic compounds, DPPH free radicals and minerals, therefore, they can be used as potential source of health food in human diets and may be of use to food industry

Peroxisome Proliferator Activator Receptor (PPAR)- γ

Hepatoprotective potential of peroxisome proliferator activator receptor (PPAR)-α and -γ agonists, fenofibrate (FEN), and pioglitazone (PIO), respectively, against cyclophosphamide (CP)-induced toxicity has been investigated in rat. FEN and PIO (150 and 10 mg/kg/day, resp.) were given orally for 4 weeks. In separate groups, CP (150 mg/kg, i.p.) was injected as a single dose 5 days before the end of experiment, with or without either PPAR agonist. CP induced hepatotoxicity, as it caused histopathological alterations, with increased serum alanine and aspartate transaminases, total bilirubin, albumin, alkaline phosphatase and lactate dehydrogenase. CP caused hepatic oxidative stress, indicated by decrease in tissue reduced glutathione, with increase in malondialdehyde and nitric oxide levels. CP also caused decrease in hepatic antioxidant enzyme levels, including catalase, superoxide dismutase, glutathione peroxidase, and glutathione S-transferase. Furthermore, CP increased serum and hepatic levels of the inflammatory marker tumor necrosis factor (TNF)-α, evaluated using ELISA. Preadministration of PIO, but not FEN, prior to CP challenge improved hepatic function and histology, and significantly reversed oxidative and inflammatory parameters. In conclusion, activation of PPAR-γ, but not PPAR-α, conferred protection against CP-induced hepatotoxicity, via activation of antioxidant and anti-inflammatory mechanisms, and may serve as supplement during CP chemotherapy

Multiset proximity spaces

L

Application of social network analysis: An approach towards client satisfaction

Project success is the ultimate goal of any project coalition. Success is a result of collective actions at all levels of any one project throughout the entire project life cycle. One principal aspect of success is the project network typology. The aim of this research is to examine and correlate high density communication networks and client satisfaction. The study is carried out through the simultaneous analysis of project success factors and project networks. The correlation is established to highlight the significance of project networks. Gap analysis and Social Network Analysis (SNA) are reviewed as tools for delivering client needs and analysing project coalitions respectively. It has been concluded that there is no standard panacea for effective project management and project success. SNA is a useful tool to help project coalitions investigate communication patterns. Two SNA case study analyses were conducted. Time and cost were identified as the major project success factors. SNA was applied to examine the discussion and information exchange networks in relation to scope of work, cost-related and schedule-related communication. Socio-grams were developed and assessed. It is also concluded that communication patterns in Design and Build projects mirror the contractual arrangements, whilst high density information exchange networks do not necessarily reflect efficient network configuration or lead to a better delivery of project objectives. SNA is an effective tool. However, it is more beneficial when combined with other tools. A combination of SNA and gap analysis provides a useful monitoring mechanism and allows project coalitions to deliver project objectives and establish better levels of client satisfaction. Keywords: project success, client satisfaction, project management, gap analysis, management tools, social network analysis, project coalitions

VALIDATED SPECTROPHOTOMETRIC METHODS FOR DETERMINATION OF ENALAPRIL MALEATE IN PURE AND DOSAGE FORMS

Objective: Simple, sensitive, precise, reproducible and validated visible spectrophotometric methods have been developed for the determination of an angiotensin converting enzyme inhibitor (ACE) drug, namely enalapril maleate (ENP) in pure and pharmaceutical dosage forms. Methods: The methods are based on the formation of yellow colored ion-pair complexes between enalapril with two sulphonphthalein acid dyes, bromocresol purple (BCP) and bromophenol blue (BPB) at pH 2.8 and 3.0 using BCP and BPB, respectively followed by their extraction with chloroform. Several parameters such as pH, buffer type, reagent volume, sequence of addition and effect of extracting solvent were optimized to achieve high sensitivity, stability, low blank reading and reproducible results.Results: The absorbance is measured at 408 and 414 nm using BCP and BPB reagents, respectively. The stoichiometric ratio of the formed ion-pair complexes was found to be 1:1 (drug: reagent) for both methods as deduced by Job's method of continuous variation. Under the optimum reaction conditions, linear relationships with good correlation coefficients (0.9993-0.9996) were found between the absorbance's and the concentrations of enalapril over the concentration ranges of 2.0–24 μg ml-1 and 2.0–28 μg ml-1 with limits of detection (LOD) of 0.39 and 0.45 μg ml-1, using BCP and BPB methods, respectively. Various analytical parameters have been evaluated and the results have been validated by statistical data.Conclusion: The proposed methods were validated in accordance with ICH guidelines and successfully applied to the determination of enalapril in pure and Dosage forms. Statistical comparison of the results obtained by applying the proposed methods with those of the official method revealed good agreement and proved that there were no significant difference in the accuracy and precision between the results.Â