30 research outputs found
Seed dormancy and germination in Dodonaea viscosa (Sapindaceae) from south-western Saudi Arabia
Dodonaea viscosa (Sapindaceae) is widespread in the mountainous highlands of the southwestern part of the Kingdom of Saudi Arabia, where it is a medicinally important species for the people of Saudi Arabia. Seeds of this species were collected from Mount Atharb in the Al-Baha region, at an altitude of 2100 m. The aims of this study were to determine if the seeds of D. viscosa have physical dormancy (i.e. a water-impermeable seed coat) and, if so, what treatments would break dormancy, and what conditions promote germination after dormancy has been broken. The dormancy-breaking treatments included: soaking of seeds in concentrated sulfuric acid (H2SO4) for 10 minutes, immersion in boiling water for 10 minutes and exposure to 50 °C for 1 minute. After seeds had been pre-treated with H2SO4, to break dormancy, they were incubated at constant temperatures from 5 to 35°C, under 12-h photoperiods or in continuous darkness, and germination recorded. Salinity tolerance was investigated by incubating acid-scarified seeds in 0, 100, 200 and 300 mM NaCl in the light at 25°C. Untreated seeds had low final germination (30%). Seeds that had been acid-scarified, immersed in boiling water or exposed to 50 °C all achieved 91% subsequently when incubated at 25°C. Thus, seeds of this species in Saudi Arabia have physical dormancy, which can be broken by all three treatments designed to increase the permeability of the testa. After pre-treatment, there was a broad optimum constant temperature for germination that ranged between 5-25°C but germination was inhibited by higher temperatures (30 and 35°C). Light had little effect on this germination response. Scarified seeds were also sensitive to salinity, with the highest germination in distilled water and complete inhibition in 400 mM NaCl. Seeds that failed to germinate in saline treatments were mostly able to germinate on transfer to distilled water, suggesting osmotic inhibition
Project manager's effectiveness in productivity of Bahrain's construction industry
SIGLEAvailable from British Library Document Supply Centre-DSC:DXN041157 / BLDSC - British Library Document Supply CentreGBUnited Kingdo
Epidemiology of Breast Cancer among Bahraini Women; Data from the Bahrain Cancer Registry
Objectives: The aim of this study was to describe the epidemiology of breast cancer among the Bahraini female population in the years 2000‒2010 and examine its health policy implications. Methods: All breast cancer cases in the Bahrain Cancer Registry from 1st January 2000 to 31st December 2010 were included. Results: There were 1,005 cases, 12.7% of which were detected by screening. The overall mean age at diagnosis was 50.9 years (95% confidence interval 50.1–51.6). The age-standardised incidence rate declined from 58.2 per 100,000 in 2000 to 44.4 per 100,000 in 2010. The majority of cases were infiltrating ductal carcinoma (76.9%). Of the registered cases, 44.1% and 48.1% had an unknown grade and stage, respectively. The five-year survival rate was 63 ± 2%. Conclusion: The low percentage of cases detected by screening merits further evaluation of Bahrain’s screening programme. More effort should be made to reduce the proportion of unknown stage and grade breast cancers. Future research has to be directed towards understanding the reasons for Bahrain having the highest incidence rate of breast cancer in the Gulf Cooperation Council countries
Germination studies on Verbesina enceliodes (Cav) Benth. et Hook ex. A. Gray (Asteraceae)
العناصر المعدنية الشحيحة في برك المياه العادمة في قطر
A one-year monitoring program was conducted to determine the extent of metal contamination in two wastewater ponds in Qatar. Abu-Hamour pond receives untreated domestic and industrial waste while Abu-NakhIa pond receives treated wastewater from two nearby wastewater treatment plants. The concentration of available metals in wastewater samples (p-g/L) and in sediment samples ((ig/kg) follows the order Mn>Cu>Cr>Pb>Ni. The order of available metal concentration in un-impacted control soil samples taken from locations 1.5 to 3 km from the ponds is Mn>Cu>Cr=Pb>Ni. Levels of available mercury and cadmium are close to or below the limits of detection (LOD) for the employed graphite furnace atomic absorption spectroscopic method. Available metals in wastewater of both ponds are significantly less than the recognized permissible upper limits for agricultural reuse.تم تقدير كميات العناصر الشحيحة في بركتي المياه العادمة في منطقتي أبو هامور (ذات المياه غير المعالجة) وأبو نخلة (ذات المياه المعالجة) وذلك بأخذ وتحليل عينات مائية ورواسب بمعدل مرة واحدة شهرياً لمدة عام واحد.
وبينت دراسة الترسبات أن ترتيب معدل التركيز المتاح للعناصر الشحيحة على النحو التالي :
منجنيز > نحاس > كروم > رصاص > نيكل.
وكما بينت الدراسة أن محتوى الكادميوم والزئبق في العينات المائية والرواسب أقل من حد الكشف باستخدام مطياف الامتصاص الذري بالتذرية الكهرو حرارية . وأظهرت دراسة الرواسب أن تركيز عناصر النحاس والنيكل والمنجنيز لا تختلف عن نظيراتها في عينات من التربة أخذت من مواقع تبعد حوالي 1.5 إلى 3 كيلو متر من حدود البركتين ، وهذا يدل على عدم تأثير التربة بطرح المياه العادمة في البركتين . أما بالنسبة لعنصري الكروم والرصاص فإن تركيزهما في رواسب كلا الموقعين يفوق تركيز نظيرهما في عينات التربة التي جمعت من مواقع بعيدة عن هاتين البركتين مما يدل على تلوثهما بهذين العنصرين وعلى سبيل المثال يبلغ معدل تركيز الرصاص في ترسبات بركة أبو هامور 60 مايكروجرام لكل كيلو جرام بينما يبلغ معدل تركيز الرصاص في التربة المجاورة الغير ملوثة بالمياه العادمة 32 مايكروجرام لكل كيلوجرام . أما بالنسبة للمياه العادمة في كلا البركتين فإن تركيز العناصر أعلاه تقل كثيرًا عن الحدود العليا المسموح بها لإعادة استخدامها للري الزراعي مما يوحي بخلوها من التلوث المعدني وامكانية استخدامها لهذا العرض