43 research outputs found

    Time-varying transmission between oil and equities in the MENA region: New evidence from DCC-MIDAS analyses

    Get PDF
    In this paper we use the DCC-MIDAS (Dynamic Conditional Correlation-Mixed Data Sampling) model to infer the association between oil and equities in five MENA countries between February 2006 and April 2017. The model indicates that higher oil returns tends to reduce the long-term risk of the Saudi market, but to increase it in other markets. The risk transfer from oil to MENA equities is found to be weak. The dynamic conditional correlation between oil and equities is not always positive and it unexpectedly changes sign during the sample period. However, the association always strengthens when there is a large draw down in oil prices as well as during periods of high volatility. Finally, we find that short term association occasionally breaks from the longer-term correlation particularly in Egypt and Turkey. These patterns of influence and associations are unique, and have important implications for equity portfolio managers who are interested in investing in energy and MENA equities

    Prevalence and sociodemographic correlates of stunting, underweight, and overweight among Palestinian school adolescents (13-15 years) in two major governorates in the West Bank

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>There is little information about height and weight status of Palestinian adolescents. The objective of this paper was to assess the prevalence of stunting, underweight, and overweight/obesity among Palestinian school adolescents (13-15 years) and associated sociodemographic factors in 2 major governorates in the West Bank.</p> <p>Methods</p> <p>A Cross-sectional survey was conducted in 2005 comprising 1942 students in 65 schools in Ramallah and Hebron governorates. Data was collected through self-administered questionnaires from students and parents. Weights and heights were measured. Overweight and obesity were assessed using the 2000 Centers for Disease Control and Prevention (CDC) reference and the International Obesity Task Force (IOTF) criteria. Stunting and underweight were assessed using the 2000 CDC reference.</p> <p>Results</p> <p>Overweight/obesity was more prevalent in Ramallah than in Hebron and affected more girls than boys. Using the 2000 CDC reference, the prevalence of overweight and obesity in Ramallah among boys was 9.6% and 8.2%, respectively versus 15.6% and 6.0% among girls (P < 0.01). In Hebron, the corresponding figures were 8.5% and 4.9% for boys and 13.5% and 3.4% for girls (P < 0.01). Using the IOTF criteria, the prevalence of overweight and obesity among boys in Ramallah was 13.3% and 5.2%, respectively versus 18.9% and 3.3% for girls. The prevalence of overweight and obesity among boys in Hebron was 10.9% and 2.2%, respectively versus 14.9% and 2.0% for girls. Overweight/obesity was associated with high standard of living (STL) among boys and with the onset of puberty among girls. More boys were underweight than girls, and the prevalence was higher in Hebron (12.9% and 6.0% in boys and girls, respectively (P < 0.01)) than in Ramallah (9.7% and 3.1% in boys and girls, respectively (p < 0.01)). The prevalence of stunting was similar in both governorates, and was higher among boys (9.2% and 9.4% in Ramallah and Hebron, respectively) than among girls (5.9% and 4.2% in Ramallah and Hebron, respectively). Stunting was negatively associated with father's education among boys and with urban residence, medium STL and onset of puberty among girls.</p> <p>Conclusion</p> <p>Under- and overnutrition co-exist among Palestinian adolescents, with differences between sexes. Region, residence, STL, and onset of puberty were associated factors.</p

    Infertility treatment outcome in sub groups of obese population

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Obesity is a common disorder with a negative impact on IVF treatment outcome. It is not clear whether morbidly obese women (BMI >= 35 kg/m2) respond to treatment differently as compared to obese women (BMI = 30–34.9 kg/m2) in IVF. Our aim was to compare the outcome of IVF or ICSI treatments in obese patients to that in morbidly obese patients.</p> <p>Methods</p> <p>This retrospective cohort study was conducted in a tertiary care centre. Patients inclusion criteria were as follows; BMI ≥ 30, age 20–40 years old, first cycle IVF/ICSI treatment with primary infertility and long follicular pituitary down regulation protocol.</p> <p>Results</p> <p>A total of 406 obese patients (group A) and 141 morbidly obese patients (group B) satisfied the inclusion criteria. Average BMI was 32.1 ± 1.38 kg/m2 for group A versus 37.7 ± 2.99 kg/m<sup>2 </sup>for group B. Patient age, cause of infertility, duration of stimulation, fertilization rate, and number of transferred embryos were similar in both groups. Compared to group A, group B had fewer medium size and mature follicles (14 vs. 16), fewer oocytes collected (7 vs. 9) and required higher doses of HMG (46.2 vs. 38.5 amps). There was also a higher cancellation rate in group B (28.3% vs. 19%) and lower clinical pregnancy rate per started cycle (19.9% vs. 28.6%).</p> <p>Conclusion</p> <p>In a homogenous infertile and obese patient population stratified according to their BMI, morbid obesity is associated with unfavorable IVF/ICSI cycle outcome as evidenced by lower pregnancy rates. It is recommended that morbidly obese patients undergo appropriate counseling before the initiation of this expensive and invasive therapy.</p

    Loss of UGP2 in brain leads to a severe epileptic encephalopathy, emphasizing that bi-allelic isoform-specific start-loss mutations of essential genes can cause genetic diseases.

    Get PDF
    Developmental and/or epileptic encephalopathies (DEEs) are a group of devastating genetic disorders, resulting in early-onset, therapy-resistant seizures and developmental delay. Here we report on 22 individuals from 15 families presenting with a severe form of intractable epilepsy, severe developmental delay, progressive microcephaly, visual disturbance and similar minor dysmorphisms. Whole exome sequencing identified a recurrent, homozygous variant (chr2:64083454A > G) in the essential UDP-glucose pyrophosphorylase (UGP2) gene in all probands. This rare variant results in a tolerable Met12Val missense change of the longer UGP2 protein isoform but causes a disruption of the start codon of the shorter isoform, which is predominant in brain. We show that the absence of the shorter isoform leads to a reduction of functional UGP2 enzyme in neural stem cells, leading to altered glycogen metabolism, upregulated unfolded protein response and premature neuronal differentiation, as modeled during pluripotent stem cell differentiation in vitro. In contrast, the complete lack of all UGP2 isoforms leads to differentiation defects in multiple lineages in human cells. Reduced expression of Ugp2a/Ugp2b in vivo in zebrafish mimics visual disturbance and mutant animals show a behavioral phenotype. Our study identifies a recurrent start codon mutation in UGP2 as a cause of a novel autosomal recessive DEE syndrome. Importantly, it also shows that isoform-specific start-loss mutations causing expression loss of a tissue-relevant isoform of an essential protein can cause a genetic disease, even when an organism-wide protein absence is incompatible with life. We provide additional examples where a similar disease mechanism applies

    Can gold be used as a hedge against the risks of Sharia-compliant securities? Application for Islamic portfolio management

    Get PDF
    In this paper, we investigate whether gold hedges Sharia-compliant stocks and Sukuk during the period from September 2005 to October 2017. The inference is taken by using both the DCC-GARCH model and the wavelet coherence analysis. On the whole, our finding suggests that gold is not effective in hedging the fluctuations of Sharia-compliant securities. However, we find that combining gold with stocks (and Sukuk) is useful in diversification and portfolio optimization. These results imply that, while gold is an excellent hedge for plain vanilla securities, it is not for Islamic exposures. This is important in light of the increasing amount of assets that are managed according to Islamic screening

    25 Years of IIF Time Series Forecasting: A Selective Review

    Full text link

    التأثير السام لبعض مشتتات البترول على زريعة أسماك البياح (البوري) في الخليج العربي

    No full text
    The acute toxicity of Shell LTX, Shell Concentrate, Servo CD 2000 and Exxon OSD 9217 were used to calculate 72 - hr. LC ci\ and toxicity curves to the Mullet Fry ( Liza macrolepis) under the Arabian Gulf conditions (Temp. s 20 C and Salinity s- 40 %°). These dispersants are specified by the manufacturers to be non - ionic and to have less than 3 % of aromatic content. The 72 - hr. LC en were 244, 55, 44 and 27 ppm respectively. These values are different from the manufactureres' information sheets probably because of using different animal species under different environmental conditions to those of the Gulf.أختيرت أربعة مشتتات بترول من الأنواع المستعملة على مدى واسع في مياه الخليج العربي عموما وفي المياه القطرية على وجه الخصوص لدراسة التأثير السام للتركيزات المختلفة من كل منها على زريعة أسماك البياح تحت ظروف المياه القطرية وقت إجراء التجربة عند درجة حرارة20 م وملوحة 40 جزء في الألف . والمشتتات المختارة من الأجيال الحديثة التي تتكون من مركبات كيميائية غير أيونية ، القاعدة العطرية فيها كمذيب لا تتعدى 3 % . وقد أثبتت مقارنات النتائج للمشتقات التي أجريت عليها الدراسة أن المشتت المسمى إكسون هو أكثرها سمية ، إذ أن التركيز القاتل منه لنصف عدد أسماك التجربة خلال مدة 72 ساعة يبلغ حوالي 27 جزء في المليون ، يليه المشتت سرفو بتركيز 44 جزء ، ثم المشتت المسمى مركز شل بتركيز 55 جزء ، وأقلها كمية هو المشتت شل لتكس بتركيز244 جزء في المليون / 72 ساعة . هذا على الرغم من أن النشرات الإعلانية لتلك المشتتات توضح أن التركيز القاتل منها يتعدى ألف جزء في المليون ؛ ربما لأن تجارب الشركات المنتجة تمت على أنواع مختلفة من الكائنات وظروف بيئية أخرى عن تلك السائدة في الخليج العربي . كذلك تطرق البحث إلى بعض التوصيات عند اللجوء إلى استخدام مشتتات البترول لمكافحة بقع الزيت
    corecore