1,957 research outputs found
A unified approach for composite cost reporting and prediction in the ACT program
The Structures Technology Program Office (STPO) at NASA Langley Research Center has held two workshops with representatives from the commercial airframe companies to establish a plan for development of a standard cost reporting format and a cost prediction tool for conceptual and preliminary designers. This paper reviews the findings of the workshop representatives with a plan for implementation of their recommendations. The recommendations of the cost tracking and reporting committee will be implemented by reinstituting the collection of composite part fabrication data in a format similar to the DoD/NASA Structural Composites Fabrication Guide. The process of data collection will be automated by taking advantage of current technology with user friendly computer interfaces and electronic data transmission. Development of a conceptual and preliminary designers' cost prediction model will be initiated. The model will provide a technically sound method for evaluating the relative cost of different composite structural designs, fabrication processes, and assembly methods that can be compared to equivalent metallic parts or assemblies. The feasibility of developing cost prediction software in a modular form for interfacing with state of the art preliminary design tools and computer aided design (CAD) programs is assessed
Chiral Nonet Mixing in pi pi Scattering
Pion pion scattering is studied in a generalized linear sigma model which
contains two scalar nonets (one of quark-antiquark type and the other of
diquark-antidiquark type) and two corresponding pseudoscalar nonets. An
interesting feature concerns the mixing of the four isosinglet scalar mesons
which yield poles in the scattering amplitude. Some realism is introduced by
enforcing exact unitarity via the K-matrix method.
It is shown that a reasonable agreement with experimental data is obtained up
to about 1 GeV. The poles in the unitarized scattering amplitude are studied in
some detail. The lowest pole clearly represents the sigma meson (or f0(600))
with a mass and decay width around 500 MeV. The second pole invites comparison
with the f0(980) which has a mass around 1 GeV and decay width around 100 MeV.
The third and fourth poles, resemble some of the isosinglet state in the
complicated 1-2 GeV region. Some comparison is made to the situation in the
usual SU(3) linear sigma model with a single scalar nonet
Are three flavors special?
It has become clearer recently that the regular pattern of three flavor
nonets describing the low spin meson multiplets seems to require some
modification for the case of the spin 0 scalar mesons. One picture which has
had some success, treats the scalars in a chiral Lagrangian framework and
considers them to populate two nonets. These are, in turn, taken to result from
the mixing of two "bare" nonets, one of which is of quark- antiquark type and
the other of two quark- two antiquark type. Here we show that such a mixing is,
before chiral symmetry breaking terms are included, only possible for three
flavors. In other cases, the two types of structure can not have the same
chiral symmetry transformation property. Specifically, our criterion would lead
one to believe that scalar and pseudoscalar states containing charm would not
have "four quark" admixtures.
This work is of potential interest for constructing chiral Lagrangians based
on exact chiral symmetry which is then broken by well known specific terms. It
may also be of interest in studying some kinds of technicolor theories
Malignant Glaucoma: A Review of the Modern Literature
Malignant glaucoma is a rare form of glaucoma that typically follows surgery in patients with primary angle closure and primary angle-closure glaucoma. In this paper, the clinical features, classification, pathogenesis, and principles of management are discussed. Despite a high prevalence of primary angle closure glaucoma in South-East Asia, the vast majority of cases of malignant glaucoma are reported in White populations. This may reflect differing mechanisms of angle closure in White and Asian patients, which somehow reduces the likelihood of an aberrant relationship developing between the lens, ciliary body, anterior hyaloid, and vitreous structures within the eye. Although the exact underlying pathogenic mechanism remains unclear, the prognosis is good with modern medical, laser, and surgical treatment modalities
Transcranial direct current stimulation and stroke recovery: opportunities and challenges
Transcranial direct current stimulation (tDCS) is one type of neuromodulation, which is an emerging technology that holds promise for the future studies on therapeutic and diagnosis applications in treatment of neurological and psychiatric diseases. However, there is a serious question among developing countries with limited financial and human resources, about the potential returns of an investment in this field and regarding the best time to transfer this technology from controlled experimental settings to health systems in the public and private sectors. This article reviews the tDCS as tools of neuromodulation for stroke and discusses the opportunities and challenges available for clinicians and researchers interested in advancing neuromodulation therapy. The aim of this review is to highlight the usefulness of tDCS and to generate an interest that will lead to appropriate studies that assess the true clinical value of tDCS for brain diseases in developing countries. Methods: Literature review was done on PubMed from 2016 on neuromodulation in under-developed countries (UDCs) by non-invasive brain stimulation methods, using the key words “stroke”, “rehabilitation”, and “tDCS”. Results: We first identified articles and websites, of which were further selected for extensive analysis mainly based on clinical relevance, study quality and reliability, and date of publication. Conclusion: Despite the promising results obtained with tDCS in basic and clinical neuroscience, further progress has been impeded by a lack of clarity to use in mostly UDCs
Promoter Hypermethylation of Tumor suppressor Genes correlates with Tumor grade and Invasiveness in patients with Urothelial Bladder Cancer
Purpose: To investigate the promoter methylation status at selected loci which encode for key proteins involved in apoptosis, DNA repair, cell cycle control and progression in urothelial cell carcinoma of bladder and compare the findings from tissue samples with that of plasma.
Methods: Total genomic DNA was isolated from 43 non-muscle invasive (low grade) and 33 muscle invasive (high grade) urothelial bladder cancer samples along with 10 control cases of normal bladder mucosa. Promoter methylation status was investigated for RASSF1A, APC, MGMT, CDKN2A and CDKN2B genes using real-time methylation-specific PCR with SYBR® green. Plasma samples from 16 patients with muscle invasive high grade bladder cancer were also subjected to similar analyses.
Results: Promoter hypermethylation was frequently observed in RASSF1A, APC and MGMT gene promoters (p-value \u3c 0.001). The methylation was more prominent in the muscle invasive high grade bladder cancer when compared to non-muscle invasive low grade group (p-value \u3c 0.001) and normal bladder mucosa (p-value \u3c 0.05). The RNA expression of RASSF1A, APC and MGMT was also found to be decreased in the muscle-invasive high grade bladder cancer when compared to the non muscle invasive low grade group (p-value \u3c 0.05). RASSF1A, MGMT and CDKN2A showed comparable results when data from 16 plasma samples was compared to the corresponding tissue samples.
Conclusion: Our results suggest that epigenetic silencing of RASSF1A, APC and MGMT genes is strongly associated with invasive high grade urothelial bladder cancer. Thus, status of promoter methylation has the potential to serve as valuable tool for assessing aggressiveness of urothelial cell carcinoma of bladder
Mandate-driven networking eco-system : a paradigm shift in end-to-end communications
The wireless industry is driven by key stakeholders that follow a holistic approach of "one-system-fits-all" that leads to moving network functionality of meeting stringent End-to-End (E2E) communication requirements towards the core and cloud infrastructures. This trend is limiting smaller and new players for bringing in new and novel solutions. For meeting these E2E requirements, tenants and end-users need to be active players for bringing their needs and innovations. Driving E2E communication not only in terms of quality of service (QoS) but also overall carbon footprint and spectrum efficiency from one specific community may lead to undesirable simplifications and a higher level of abstraction of other network segments may lead to sub-optimal operations. Based on this, the paper presents a paradigm shift that will enlarge the role of wireless innovation at academia, Small and Medium-sized Enterprises (SME)'s, industries and start-ups while taking into account decentralized mandate-driven intelligence in E2E communications
Exploration of nutraceutical potential of herbal oil formulated from parasitic plant
Background: Cuscuta reflexa (C. reflexa) is a parasitic climber of medicinal importance. The present study was aimed to evaluate the nutraceutical potential of C. reflexa stems collected from different hosts and to evaluate the role of the herbal formulation in dandruff, hair fall control as well as hair growth promoter.Materials and Methods: Hair formulations of C. reflexa collected from different host plants were prepared in the form of herbal oils (10% w/v). C. reflexa stems were extracted using mustard oil as base oil by using direct boiling technique. Prepared oil was studied as hair tonic. The experimental protocols used were anti-dandruff hair growth activity, as well as hair fall reduction. Herbal hair oils versus mustard oil were evaluated by applying oils on human volunteers with hair fall and dandruff problem whereas promotion of hair growth activity was conducted on rats. The formulated oils were also characterised for proximate analysis, physiochemical composition, as well as antimicrobial activity.Result: The test oils of C. reflexa collected from Azadiracta indica and Zizyphus jujuba were effective in the promotion of hair growth, dandruff control, as well as reduction in hair fall activity.Conclusion: All the formulated oils showed potent antimicrobial activity against all selected strains of bacteria and fungi.Keywords: Cuscuta reflexa, host plants, Hair fall, Dandruff, Combing assay, Herbal hair oil, Hair growth activity
Calling For Diversity In Health Care Executive Suites And Evaluation Of Effects On Efficiency Using Data Envelopment Analysis
Adequate diversity in the leadership of health care organizations is a problem that potentially affects overall performance. In this paper, we propose the application of data envelopment analysis (DEA) and strategic human information systems to determine how diversity affects the efficiency, stability, and long-term viability of health care organizations at the organization level. Data envelopment analysis could also be applied within a given health care organization to examine how the organization’s diversity make-up in its various departments affects relative efficiencies across the departments. After presenting a brief introduction of DEA, we provide examples of inputs and outputs used in a proposed DEA analysis. We also propose the use of strategic information systems in health care organizations in developing countries at both organization and departmental levels. We suggest that both developed and developing countries would benefit from using these tools as they seek to control costs and improve health care systems
Approach to Data Science with Multiscale Information Theory
Data Science is a multidisciplinary field that plays a crucial role in
extracting valuable insights and knowledge from large and intricate datasets.
Within the realm of Data Science, two fundamental components are Information
Theory (IT) and Statistical Mechanics (SM), which provide a theoretical
framework for understanding dataset properties. IT enables efficient storage
and transmission of information, while SM focuses on the behavior of systems
comprising numerous interacting components. In the context of data science, SM
allows us to model complex interactions among variables within a dataset. By
leveraging these tools, data scientists can gain a profound understanding of
data properties, leading to the development of advanced models and algorithms
for analysis and interpretation. Consequently, data science has the potential
to drive accurate predictions and enhance decision-making across various
domains, including finance, marketing, healthcare, and scientific research.
In this paper, we apply this data science framework to a large and intricate
quantum mechanical system composed of particles. Our research demonstrates that
the dynamic and probabilistic nature of such systems can be effectively
addressed using a Multiscale Entropic Dynamics (MED) approach, derived from the
Boltzmann methods of SM. Through the MED approach, we can describe the system's
dynamics by formulating a general form of the Nonlinear Schr\"odinger equation
and how it can be applied to various systems with particles and
quasi-particles, such as electrons, plasmons, polarons, and solitons. By
employing this innovative approach, we pave the way for a deeper understanding
of quantum mechanical systems and their behaviors within complex materials.Comment: 12 page
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