4,716 research outputs found
Upper Airways Microbiota in Antibiotic-Naive Wheezing and Healthy Infants from the Tropics of Rural Ecuador
Background: Observations that the airway microbiome is disturbed in asthma may be confounded by the widespread use
of antibiotics and inhaled steroids. We have therefore examined the oropharyngeal microbiome in early onset wheezinginfants from a rural area of tropical Ecuador where antibiotic usage is minimal and glucocorticoid usage is absent.
Materials and Methods: We performed pyrosequencing of amplicons of the polymorphic bacterial 16S rRNA gene from
oropharyngeal samples from 24 infants with non-infectious early onset wheezing and 24 healthy controls (average age 10.2 months). We analyzed microbial community structure and differences between cases and controls by QIIME software.
Results: We obtained 76,627 high quality sequences classified into 182 operational taxonomic units (OTUs). Firmicutes was the most common and diverse phylum (71.22% of sequences) with Streptococcus being the most common genus (49.72%). Known pathogens were found significantly more often in cases of infantile wheeze compared to controls, exemplified by Haemophilus spp. (OR = 2.12, 95% Confidence Interval (CI) 1.82–2.47; P = 5.46610223) and Staphylococcus spp. (OR = 124.1, 95%CI 59.0–261.2; P = 1.876102241). Other OTUs were less common in cases than controls, notably Veillonella spp. (OR = 0.59, 95%CI = 0.56–0.62; P = 8.06610286).
Discussion: The airway microbiota appeared to contain many more Streptococci than found in Western Europe and the
USA. Comparisons between healthy and wheezing infants revealed a significant difference in several bacterial phylotypes that were not confounded by antibiotics or use of inhaled steroids. The increased prevalence of pathogens such as Haemophilus and Staphylococcus spp. in cases may contribute to wheezing illnesses in this age group
Racially diverse neighborhoods in diverse areas are linked to lower crime rates
In new research, Young-An Kim and James C. Wo look at the implications of increasing racial and ethnic diversity in America’s communities on crime. Using evidence from Southern California, they tested the effects of racial diversity on neighborhood crime rates, finding that there were fewer violent and property crimes in neighborhood blocks which were more diverse, and especially those in more diverse areas. They attribute this to the greater opportunities created by diverse communities to overcome bias and create social ties and trust across different groups
Slightly generalized Generalized Contagion: Unifying simple models of biological and social spreading
We motivate and explore the basic features of generalized contagion, a model
mechanism that unifies fundamental models of biological and social contagion.
Generalized contagion builds on the elementary observation that spreading and
contagion of all kinds involve some form of system memory. We discuss the three
main classes of systems that generalized contagion affords, resembling: simple
biological contagion; critical mass contagion of social phenomena; and an
intermediate, and explosive, vanishing critical mass contagion. We also present
a simple explanation of the global spreading condition in the context of a
small seed of infected individuals.Comment: 8 pages, 5 figures; chapter to appear in "Spreading Dynamics in
Social Systems"; Eds. Sune Lehmann and Yong-Yeol Ahn, Springer Natur
Survivin a radiogenetic promoter for glioblastoma viral gene therapy independently from CArG motifs
BACKGROUND: Radiogenetic therapy is a novel approach in the treatment of cancer, which employs genetic modification to alter the sensitivity of tumor cells to the effect of applied radiation. AIM: To select a potent radiation inducible promoter in the context of brain tumors and to investigate if CArG radio responsive motifs or other elements in the promoter nucleotide sequences can correlate to its response to radiation. METHODS: To select initial candidates for promoter inducible elements, the levels of mRNA expression of six different promoters were assessed using Quantitative RTPCR in D54 MG cells before and after radiation exposure. Recombinant Ad/reporter genes driven by five different promoters; CMV, VEGF, FLT-1, DR5 and survivin were constructed. Glioma cell lines were infected with different multiplicity of infection of the (promoter) Ad or CMV Ad. Cells were then exposed to a range of radiation (0–12 Gy) at single fraction. Fluorescent microscopy, Luc assay and X-gal staining was used to detect the level of expression of related genes. Different glioma cell lines and normal astrocytes were infected with Ad survivin and exposed to radiation. The promoters were analyzed for presence of CArG radio-responsive motifs and CCAAT box consensus using NCBI blast bioinformatics software. RESULTS: Radiotherapy increases the expression of gene expression by 1.25–2.5 fold in different promoters other than survivin after 2 h of radiation. RNA analysis was done and has shown an increase in copy number of tenfold for survivin. Most importantly cells treated with RT and Ad Luc driven by survivin promoter showed a fivefold increase in expression after 2 Gy of radiation in comparison to non-irradiated cells. Presence or absence of CArG motifs did not correlate with promoter response to radiation. Survivin with the best response to radiation had the lowest number of CCAAT box. CONCLUSION: Survivin is a selective potent radiation inducible promoter for glioblastoma viral gene therapy and this response to radiation could be independent of CArG motifs
On the exit statistics theorem of many particle quantum scattering
We review the foundations of the scattering formalism for one particle
potential scattering and discuss the generalization to the simplest case of
many non interacting particles. We point out that the "straight path motion" of
the particles, which is achieved in the scattering regime, is at the heart of
the crossing statistics of surfaces, which should be thought of as detector
surfaces. We sketch a proof of the relevant version of the many particle flux
across surfaces theorem and discuss what needs to be proven for the foundations
of scattering theory in this context.Comment: 15 pages, 4 figures; to appear in the proceedings of the conference
"Multiscale methods in Quantum Mechanics", Accademia dei Lincei, Rome,
December 16-20, 200
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From Patterning Genes to Process: Unraveling the Gene Regulatory Networks That Pattern Heliconius Wings
Butterfly wing patterns have emerged as exceptional model systems with which to link the developmental and genetic processes that generate morphological variation with the ecological and evolutionary processes that shape this variation in natural populations. Among butterflies, research on species within the genus Heliconius has provided remarkable opportunities to explore how phenotypic diversity is generated within the context of an extraordinary adaptive radiation. Wing pattern diversity among the 48 species and hundreds of intraspecific variants arose within the last 12–14 million years and includes striking pattern convergence between distantly related species, as well as marked pattern divergence between closely related populations and species. Here, we synthesize recent research aimed at gaining a mechanistic understanding of how this variation is generated. This research integrates decades of controlled crossing experiments, and the discovery of major wing patterning genes (optix, aristaless1, WntA and cortex) with recent functional genetic manipulation using CRISPR/Cas9 targeted mutagenesis. The emerging data provides a rich framework with which to explore the repeatability of evolution, particularly within the context of how natural selection acts on divergent gene regulatory networks to generate both highly convergent, as well as highly divergent phenotypes. Overall, the functional data show that the gene regulatory networks underlying pattern variation diverge rapidly in Heliconius; yet these networks retain enough flexibility so that natural selection can drive the evolution of nearly identical patterns from different developmental genetic starting points. Moreover, for the first time this research is starting to illuminate the links between the genetic changes modulating pattern variation and how they influence the larger gene networks that are ultimately responsible for patterning a butterfly wing. There are still large gaps in our understanding, but current research priorities are well laid out and experimental methodologies are in place to address them. The challenge is to synthesize diverse research strategies into a cohesive picture of morphological evolution
Cider: a Rapid Docker Container Deployment System through Sharing Network Storage
Container technology has been prevalent and widely-adopted in production environment considering the huge benefits to application packing, deploying and management. However, the deployment process is relatively slow by using conventional approaches. In large-scale concurrent deployments, resource contentions on the central image repository would aggravate such situation. In fact, it is observable that the image pulling operation is mainly responsible for the degraded performance. To this end, we propose Cider - a novel deployment system to enable rapid container deployment in a high concurrent and scalable manner at scale. Firstly, on-demand image data loading is proposed by altering the local Docker storage of worker nodes into all-nodes-sharing network storage. Also, the local copy-on-write layer for containers can ensure Cider to achieve the scalability whilst improving the cost-effectiveness during the holistic deployment. Experimental results reveal that Cider can shorten the overall deployment time by 85% and 62% on average when deploying one container and 100 concurrent containers respectively
D^2PS: A Dependable Data Provisioning Service in Multi-tenant Cloud Environment
Software as a Service (SaaS) is a software delivery and business model widely used by Cloud computing. Instead of purchasing and maintaining a software suite permanently, customers only need to lease the software on-demand. The domain of high assurance distributed systems has focused greatly on the areas of fault tolerance and dependability. In a multi-tenant context, it is particularly important to store, manage and provision data services to customers in a highly efficient and dependable manner due to a large number of file operations involved in running such services. It is also desirable to allow a user group to share and cooperate (e.g., co-edit) on some specific data. In this paper we present a dependable data provisioning service in a multi-tenant Cloud environment. We describe a metadata management approach and leverage multiple replicated metadata caching to shorten the file access time, with the improved efficiency of data sharing. In order to reduce frequent data transmission and data access latency, we introduce a distributed cooperative disk cache mechanism that supports effective cache placement and pull-push cache synchronization. In addition, we use efficient component failover to enhance the service dependability whilst avoiding negative impact from system failures. Our experimental results show that our system can significantly reduce both unused data transmission and response latency. Specifically, over 50% network transmission and operational latency can be saved for random reads while 28.24% network traffic and 25% response latency can be reduced for random write operations. We believe that these findings are demonstrating positive results along the right direction of resolving storage-related challenges in a multi-tenant Cloud environment
Biosafety practices and biomedical hazards among the support staff of Kenyatta national hospital, Mbagathi district hospital and Kiambu district hospital in Kenya
Biomedical hazards, also known as infectious hazards or medical hazards are defined as hazards generated during the diagnosis, testing, treatment, research or production of biological products for humans or animals. This study aimed at determining biosafety practices and biomedical hazards among the support staff from Kenyatta National Hospital, Mbagathi District Hospital and Kiambu District Hospital. A descriptive study design was employed for this study to sample the support staff working in the three hospitals. The respondents were strictly the hospital support staff in cleaning, mortuary and handling of health care waste. Probability sampling method was used to select out the 400 respondents. Structured questionnaire was used for data collection which was analyzed using SPSS. Blood and blood products, tissues, sharps and used materials by patients were identified as the major biohazards to hospital support staff. Approximately 33 (63.5%) hospital support staff from Mbagathi District hospital, 35 (67.3%) from Kiambu District hospital and 195 (66.7%) from Kenyatta hospital agreed that they handled blood, sharps and other materials used by patients in the hospitals. The Pearson Chi‐Square Tests χ2 (8) =15.546; P=0.046 implied that the Handling blood, sharp or any other materials used by patients in hospital had association with the hospital the respondents came from. In conclusion the study has demonstrated that hospital support staff needs to be trained on biosafety issues especially medical waste management because their practices are below standards. Hospitals used in the study are facing many challenges because this sector is almost ignored in terms of safety of support staff, segregation, collection, transport, treatment and final disposal. The study recommends that all staff and waste handlers in each hospital should agree on responsibilities towards biosafety policy in Kenya.Key words: Biomedical hazards, biological products, biosafety, waste management
Profitability of bioethanol production using cassava (Manihot esculantus Crantz) and sweet potato (Ipomea batatas) as raw material
Ethanol imports into developing countries such as Ghana over the past decade have been on the increase. Corn, sugarcane and wheat are major crops that are normally used globally to produce bioethanol. The use of cassava and sweet potato as raw materials for ethanol production has also been demonstrated. Cassava and sweet potato, which grow excellently in Sub-Saharan Africa, could therefore be used as excellent and readily available local raw material for ethanol production to replace the seventy (70) million litres and more of ethanol imported into Ghana in 2016 for various uses. The search for the optimum processing conditions to hydrolyse and ferment sugars from the starches in cassava and sweet potato had been the major focus of all the studies in the past. The price of ethanol produced with cassava and sweet potato compared to the price of ethanol produced with other feedstock in the global market would largely determine the competitiveness and sustainability of producing ethanol with cassava and sweet potato. The objective of this work is to evaluate the cost benefits of ethanol production using cassava and sweet potato as raw materials. Sika bankye (cassava variety) and Apomuden (sweet potato variety) were cultivated and harvested at ten (10) months and three (3) months maturity respectively for the study. Liquefaction, saccharification and fermentation of the cassava and sweet potato varieties to produce ethanol were carried out with Liquozyme SC DS, combination of Spirizyme Fuel and Viscozyme L and Bio-Ferm XR (Lallemand) yeast, respectively. The study indicates that the production of ethanol with a 1:1 mixture of cassava and sweet potato using a 10,000 litres per day capacity ethanol distilling plant generates a net profit of between 9% and 30% over a period of five years. The findings indicate that ethanol production with cassava and sweet potato is a profitable venture
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