CLOCK expression identifies developing circadian oscillator neurons in the brains of Drosophila embryos

<p>Abstract</p> <p>Background</p> <p>The <it>Drosophila </it>circadian oscillator is composed of transcriptional feedback loops in which CLOCK-CYCLE (CLK-CYC) heterodimers activate their feedback regulators <it>period </it>(<it>per</it>) and <it>timeless </it>(<it>tim</it>) via E-box mediated transcription. These feedback loop oscillators are present in distinct clusters of dorsal and lateral neurons in the adult brain, but how this pattern of expression is established during development is not known. Since CLK is required to initiate feedback loop function, defining the pattern of CLK expression in embryos and larvae will shed light on oscillator neuron development.</p> <p>Results</p> <p>A novel CLK antiserum is used to show that CLK expression in the larval CNS and adult brain is limited to circadian oscillator cells. CLK is initially expressed in presumptive small ventral lateral neurons (s-LN_vs), dorsal neurons 2 s (DN₂s), and dorsal neuron 1 s (DN₁s) at embryonic stage (ES) 16, and this CLK expression pattern persists through larval development. PER then accumulates in all CLK-expressing cells except presumptive DN₂s during late ES 16 and ES 17, consistent with the delayed accumulation of PER in adult oscillator neurons and antiphase cycling of PER in larval DN₂s. PER is also expressed in non-CLK-expressing cells in the embryonic CNS starting at ES 12. Although PER expression in CLK-negative cells continues in <it>Clk</it>^Jrkembryos, PER expression in cells that co-express PER and CLK is eliminated.</p> <p>Conclusion</p> <p>These data demonstrate that brain oscillator neurons begin development during embryogenesis, that PER expression in non-oscillator cells is CLK-independent, and that oscillator phase is an intrinsic characteristic of brain oscillator neurons. These results define the temporal and spatial coordinates of factors that initiate <it>Clk </it>expression, imply that circadian photoreceptors are not activated until the end of embryogenesis, and suggest that PER functions in a different capacity before oscillator cell development is initiated.</p

The Risks of Financial Derivatives and Alternatives from the Viewpoint of Islamic Economics

Purpose: This study aims to introduce financial derivatives and their tools and the risks they cause, with an indication of their relationship to financial crises, which contributes to drawing the broad outlines of the Islamic alternative and determines the reality of the failure of the global financial system in managing risks through traditional financial derivatives.   Theoretical framework: Introduce financial derivatives and their tools and the risks they cause, with an indication of their relationship to financial crises, and alternatives from the point of view of Islamic economics.   Methodology: The study was based on a qualitative research method, as it collected information from books, reports, magazines, newspapers, and websites.   Findings: The financial derivatives increased risks and led us into crises. while Islamic Sharia provides an alternative to risk management, which focuses on avoiding fake sales and creating ethical and clean financial markets.   Research, Practical &amp; Social implications: Financial markets, financial derivatives markets, financial institutions, banks, and insurance companies are considered. And small customers, the most important beneficiaries of these ideas.   Originality/value: This research is the original work of the authors and differs from other previous studies in that it proves the existence of a disciplined Islamic alternative within the foundations and standards of Islamic economics and shows its feasibility for successful practical application, particularly in the face of financial crises, addressing them during their occurrence and preventing them before they occur

The Role of Financial Inclusion in the Stability of Islamic Banks

Purpose: The purpose of this research is studying the role of financial inclusion on financial stability in the Islamic banks, Highlighting the role of Islamic law in promoting financial and banking inclusion.   Theoretical framework: Introduce financial inclusion and definition of financial inclusion, statement of financial stability, and the role of financial inclusion in the stability of Islamic banks, in which the concept of financial inclusion and its dimensions was reviewed.   Methodology: The study was based on a qualitative research method, as it collected information from books, reports, journals, newspapers, and websites. The study adopted the descriptive analytical approach to study and analyze the various aspects of financial inclusion, its dimensions in Islamic banks, and its relationship in financial stability.   Findings: The relationship between financial stability and financial inclusion in Islamic banks is a direct relationship and financial stability cannot be reached without achieving financial inclusion and vice versa. The financial sectors must develop two sectors in parallel to achieve the desired economic development.   Research, Practical &amp; Social implications: Central banks, Islamic banks (clients /staff), financial institutions, and small clients are the main beneficiaries of these ideas.   Originality/value: This study contributes to determining the role of financial inclusion in financial stability, using Islamic banks, which is to determine the effect of applying financial inclusion on the financial investment of Islamic banks. The research is based on a lack of studies on research variables

Perturbing Dynamin Reveals Potent Effects on the Drosophila Circadian Clock

BACKGROUND: Transcriptional feedback loops are central to circadian clock function. However, the role of neural activity and membrane events in molecular rhythms in the fruit fly Drosophila is unclear. To address this question, we expressed a temperature-sensitive, dominant negative allele of the fly homolog of dynamin called shibire(ts1) (shi(ts1)), an active component in membrane vesicle scission. PRINCIPAL FINDINGS: Broad expression in clock cells resulted in unexpectedly long, robust periods (>28 hours) comparable to perturbation of core clock components, suggesting an unappreciated role of membrane dynamics in setting period. Expression in the pacemaker lateral ventral neurons (LNv) was necessary and sufficient for this effect. Manipulation of other endocytic components exacerbated shi(ts1)'s behavioral effects, suggesting its mechanism is specific to endocytic regulation. PKA overexpression rescued period effects suggesting shi(ts1) may downregulate PKA pathways. Levels of the clock component PERIOD were reduced in the shi(ts1)-expressing pacemaker small LNv of flies held at a fully restrictive temperature (29 degrees C). Less restrictive conditions (25 degrees C) delayed cycling proportional to observed behavioral changes. Levels of the neuropeptide PIGMENT-DISPERSING FACTOR (PDF), the only known LNv neurotransmitter, were also reduced, but PERIOD cycling was still delayed in flies lacking PDF, implicating a PDF-independent process. Further, shi(ts1) expression in the eye also results in reduced PER protein and per and vri transcript levels, suggesting that shibire-dependent signaling extends to peripheral clocks. The level of nuclear CLK, transcriptional activator of many core clock genes, is also reduced in shi(ts1) flies, and Clk overexpression suppresses the period-altering effects of shi(ts1). CONCLUSIONS: We propose that membrane protein turnover through endocytic regulation of PKA pathways modulates the core clock by altering CLK levels and/or activity. These results suggest an important role for membrane scission in setting circadian period

The Jordanian economy: between reality and expectations

The global economy engaging in conflict with the three economic and financial crises is unprecedented in terms of economic growth, particularly for emerging economies and developing countries, and the deterioration of indicators of financial strength in international credit markets, particularly in the markets of the United Nations and Europe, and we will try through this research to shed light on Jordan's economy in light of these circumstances, in an attempt to measure their performance through a range of financial and sectoral indicators including economic growth, , the researcher employed investigative and deductive analysis methodology, using scholars and thinkers’ statements to scrutinise and study subject understudy

Role of media in islamic countries in the face of current challenges

Debate with regard to the role of media in the face of challenges have been taking place since a long time ago. To this end, some political schools of thought have categorized media as at the same level as the military and economic powers in the world. As can be seen, developed countries used the media industry to serve their interests. Although Islamic countries got their political independence, they failed to get independence in other areas. Islamic countries’ reaction towards the West came in the form of unequal clashes which resulted in accumulation of multiple defeats including moral aspects. This could be due to the nature of obstacles and challenges faced by the media in Islamic countries. Consequently, the war between Muslims and the West is due partly to the negligence of the Muslims in developing a more advanced media that would have eliminated uncertainty and antagonism between the two parties. These are some of the challenges facing media in Islamic countries which require special attention from Muslim ummah