Concepts and methods in optimization of integrated LC VCOs

Underlying physical mechanisms controlling the noise properties of oscillators are studied. This treatment shows the importance of inductance selection for oscillator noise optimization. A design strategy centered around an inductance selection scheme is executed using a practical graphical optimization method to optimize phase noise subject to design constraints such as power dissipation, tank amplitude, tuning range, startup condition, and diameters of spiral inductors. The optimization technique is demonstrated through a design example, leading to a 2.4-GHz fully integrated, LC voltage-controlled oscillator (VCO) implemented using 0.35-μm MOS transistors. The measured phase-noise values are -121, -117, and -115 dBc/Hz at 600-kHz offset from 1.91, 2.03, and 2.60-GHz carriers, respectively. The VCO dissipates 4 mA from a 2.5-V supply voltage. The inversion mode MOSCAP tuning is used to achieve 26% of tuning range. Two figures of merit for performance comparison of various oscillators are introduced and used to compare this work to previously reported results

Virtual damping and Einstein relation in oscillators

This paper presents a new physical theory of oscillator phase noise. Built around the concept of phase diffusion, this work bridges the fundamental physics of noise and existing oscillator phase-noise theories. The virtual damping of an ensemble of oscillators is introduced as a measure of phase noise. The explanation of linewidth compression through virtual damping provides a unified view of resonators and oscillators. The direct correspondence between phase noise and the Einstein relation is demonstrated, which reveals the underlying physics of phase noise. The validity of the new approach is confirmed by consistent experimental agreement

Neurological Manifestations of Dural Sinus Thrombosis

Background:Dural sinus thrombosis is a clinical syndrome that has a diversity of signs and symptoms that can be easily misinterpreted with other common neurological diseases such as brain infections.Objective: to study the clinical presentation of dural sinus thrombosis among Sudanese patients seen at Elshaab Teaching Hospital.Methodology: This is a prospective, descriptive, cross sectional, hospital based study conducted in Elshaab Teaching Hospital- Khartoum Sudan, in the period from November 2008 to July 2010. All adult Sudanese patients with dural sinus thrombosis who were admitted to the hospital and accepted to participate in the study during the period from November 2008-July2010 (50 patients) were enrolled. History, clinical examination and relevant investigations including MRI were done for all patients. Data were collected, analyzed, conclusions drawn and recommendations stated.Results: Females (98%) in child bearing age were mostly affected. Delivery and pregnancy were the common risk factors; head ache, neck pain and stiffness were the frequent neurological symptoms. Papilledema was the commonest neurological finding. Saggital sinus thrombosis wasfound to be the major radiological finding and great majority of patients showed remarkable improvement with treatment.Conclusion: Dural sinus thrombosis is uncommon neurological problem, however the diagnosis should always be considered in the right clinical setting, as it is a treatable conditionKey Word:dura mater,subarachnoid, cerebrospinal fluid

Validation of reported physical activity for cholesterol control using two different physical activity instruments

The National Cholesterol Education Program recommends increasing physical activity to improve cholesterol levels and overall cardiovascular health. We examined whether US adults who reported increasing their physical activity to control or lower blood cholesterol following physician’s advice or on their own efforts had higher levels of physical activity than those who reported that they did not. We used data from the National Health and Nutrition Examination Survey 2003–2004, which implemented two physical activity assessment instruments. The physical activity questionnaire (PAQ) assessed self-reported frequency, intensity, and duration of leisure-time, household, and transportation-related physical activity in the past month. Physical movement was objectively monitored using a waist accelerometer that assessed minute-by-minute intensity (counts of movement/minute) during waking time over a 7-day period. We adjusted our analysis for age, gender, race/ethnicity, educational attainment, and body mass index. Participants who reported increasing physical activity to control blood cholesterol had more PAQ-assessed physical activity and more accelerometer-assessed active days per week compared to those who did not. However, there were no significant differences in cholesterol levels between comparison groups. These findings suggest that self-report of exercising more to control or lower cholesterol levels among US adults might be valid

Characterisation of the androgen regulation of glycine N-methyltransferase in prostate cancer cells

The development and growth of prostate cancer is dependent on androgens; thus, the identification of androgen-regulated genes in prostate cancer cells is vital for defining the mechanisms of prostate cancer development and progression and developing new markers and targets for prostate cancer treatment. GlycineN-methyltransferase (GNMT) is aS-adenosylmethionine-dependent methyltransferase that has been recently identified as a novel androgen-regulated gene in prostate cancer cells. Although the importance of this protein in prostate cancer progression has been extensively addressed, little is known about the mechanism of its androgen regulation. Here, we show that GNMT expression is stimulated by androgen in androgen receptor (AR) expressing cells and that the stimulation occurs at the mRNA and protein levels. We have identified an androgen response element within the first exon of theGNMTgene and demonstrated that AR binds to this elementin vitroandin vivo. Together, these studies identify GNMT as a direct transcriptional target of the AR. As this is an evolutionarily conserved regulatory element, this highlights androgen regulation as an important feature of GNMT regulation.</jats:p

VCU Research Festival: From Ideas to Impact

Since its beginning, VCU has been inextricably intertwined with the Richmond community - physically, socially, and economically. That dynamic interdependence, if leveraged correctly, can help us achieve the vision of Quest 2028. VCU’s website notes, “...our past has made us who we are…” And that past has not always helped maintain our critical relationship with the surrounding community. It is telling that this year’s VCU Common Book is Organ Thieves — a book about VCU’s own Henrietta Lacks story. Research at VCU led to Virginia’s first organ transplants, but there are different stories we can tell about VCU’s historic roads to success. And the stories our community has heard have not always built bridges. We want to change that. We also want to open VCU’s doors to the surrounding community. Many academic institutions are seen as “ivory towers,” but that is not the mission of VCU. We want to pull back the curtain on the impactful, innovative research happening here so that the community better understands what we’re working on. Where and how can we engage the Richmond community with VCU’s research and earn their trust? Richmonders love festivals. They are a part of our shared culture — a place where we can celebrate differences, learn from each other, and enjoy being good neighbors. We propose a VCU Research festival to rebuild the critical relationship between VCU and the community. The VCU Research Festival will build goodwill with the community surrounding VCU by showcasing the impactful and innovative research happening at VCU and the VCU Health System (referred to collectively as “OneVCU”). We envision a oneday event where diverse VCU faculty and student researchers from across disciplines will showcase their work in a single space, emphasizing interactive/hands-on displays that engage attendees. Our goal is for the event to feel like a festival, including art performances, TED Talkstyle presentations, food trucks, etc. The event will be open to the public, helping VCU share its mission with the community, demonstrate its commitment to benefiting humanity at large, and lay the additional groundwork for community-engaged research. Key external stakeholders, including elected officials, donors, and business leaders, would be invited to attend, improving VCU’s local reputation and national prominence. Planning of the event will require the collaborative work of several units at VCU, including the Office of the Vice President for Research and Innovation (OVPRI), University Relations, the Provost’s office, and the Office of Institutional Equity, Effectiveness, and Success

Narrowing of EIT resonance in a Doppler Broadened Medium

We derive an analytic expression for the linewidth of EIT resonance in a Doppler broadened system. It is shown here that for relatively low intensity of the driving field the EIT linewidth is proportional to the square root of intensity and is independent of the Doppler width, similar to the laser induced line narrowing effect by Feld and Javan. In the limit of high intensity we recover the usual power broadening case where EIT linewidth is proportional to the intensity and inversely proportional to the Doppler width.Comment: 4 pages, 2 figure

The Socio-economic Impacts of Social Media Privacy and Security Challenges

© 2020, Springer Nature Singapore Pte Ltd. Privacy and Security are two major challenges faced by users on social media today. These challenges are experienced in diverse ways and forms by different types of users across the web. While technological solutions are usually implemented to address them, the effects have proven to be limited so far. Despite continuous deployment of technological solutions, the need to evaluate socio-economic impacts of these challenges have also become more imperative. Hence, this paper provides a critical review and analysis of socio-economic impacts of these social media challenges. The research findings reveal significant levels of negative socio-economic impacts and provides an evaluation framework towards defining the scope, thereby identifying appropriate measures for both addressing the challenges and curbing the socio-economic impacts. The findings also demonstrate the need for solutions beyond the use of technology, to employing and deploying solutions from social sciences which deals with behavioral issues and how to address them

The Genomes of the Fungal Plant Pathogens Cladosporium fulvum and Dothistroma septosporum Reveal Adaptation to Different Hosts and Lifestyles But Also Signatures of Common Ancestry.

We sequenced and compared the genomes of the Dothideomycete fungal plant pathogensCladosporium fulvum (Cfu) (syn. Passalora fulva) and Dothistroma septosporum (Dse) that are closely related phylogenetically, but have different lifestyles and hosts. Although both fungi grow extracellularly in close contact with host mesophyll cells, Cfu is a biotroph infecting tomato, while Dse is a hemibiotroph infecting pine. The genomes of these fungi have a similar set of genes (70% of gene content in both genomes are homologs), but differ significantly in size (Cfu \u3e61.1-Mb; Dse 31.2-Mb), which is mainly due to the difference in repeat content (47.2% in Cfu versus 3.2% in Dse). Recent adaptation to different lifestyles and hosts is suggested by diverged sets of genes. Cfu contains an α-tomatinase gene that we predict might be required for detoxification of tomatine, while this gene is absent in Dse. Many genes encoding secreted proteins are unique to each species and the repeat-rich areas in Cfu are enriched for these species-specific genes. In contrast, conserved genes suggest common host ancestry. Homologs of Cfu effector genes, including Ecp2 and Avr4, are present in Dse and induce a Cf-Ecp2- and Cf-4-mediated hypersensitive response, respectively. Strikingly, genes involved in production of the toxin dothistromin, a likely virulence factor for Dse, are conserved in Cfu, but their expression differs markedly with essentially no expression by Cfu in planta. Likewise, Cfu has a carbohydrate-degrading enzyme catalog that is more similar to that of necrotrophs or hemibiotrophs and a larger pectinolytic gene arsenal than Dse, but many of these genes are not expressed in planta or are pseudogenized. Overall, comparison of their genomes suggests that these closely related plant pathogens had a common ancestral host but since adapted to different hosts and lifestyles by a combination of differentiated gene content, pseudogenization, and gene regulation