47 research outputs found
Ordered hierarchy versus scale invariance in sequence stratigraphy
200 x 10(6) years) are symmetrical transgressive- regressive cycles. However, the sequence record in the range of 1 x 10(4)-200 x 10(6) years, the principal domain of sequence stratigraphy, shows a rather irregular succession of sequences with variable symmetry and bounded by flooding surfaces or exposure surfaces. For these time scales, scale-invariant models are a good first approximation, particularly because the evidence for scale-invariance and randomness in the stratigraphic record is strong: Frequency spectra of sea-level change as well as rates of sedimentation and rates of accommodation change plotted against length of observation span show basic trends indistinguishable from random walk. These trends, combined with scale-invariant sequence models may be the most efficient tools for across-the-board predictions on sequences and for locating islands of order in the sequence record
Viral, bacterial, and fungal infections of the oral mucosa:Types, incidence, predisposing factors, diagnostic algorithms, and management
For millions of years, microbiota residing within us, including those in the oral cavity, coexisted in a harmonious symbiotic fashion that provided a quintessential foundation for human health. It is now clear that disruption of such a healthy relationship leading to microbial dysbiosis causes a wide array of infections, ranging from localized, mild, superficial infections to deep, disseminated life-threatening diseases. With recent advances in research, diagnostics, and improved surveillance we are witnessing an array of emerging and re-emerging oral infections and orofacial manifestations of systemic infections. Orofacial infections may cause significant discomfort to the patients and unnecessary economic burden. Thus, the early recognition of such infections is paramount for holistic patient management, and oral clinicians have a critical role in recognizing, diagnosing, managing, and preventing either new or old orofacial infections. This paper aims to provide an update on current understanding of well-established and emerging viral, bacterial, and fungal infections manifesting in the human oral cavity.</p
Neuroprotective effects of intrastriatal injection of rapamycin in a mouse model of excitotoxicity induced by quinolinic acid
BACKGROUND: The mammalian target of rapamycin (mTOR) is a kinase involved in a variety of physiological and pathological functions. However, the exact role of mTOR in excitotoxicity is poorly understood. Here, we investigated the effects of mTOR inhibition with rapamycin against neurodegeneration, and motor impairment, as well as inflammatory profile caused by an excitotoxic stimulus. METHODS: A single and unilateral striatal injection of quinolinic acid (QA) was used to induce excitotoxicity in mice. Rapamycin (250 nL of 0.2, 2, or 20 μM; intrastriatal route) was administered 15 min before QA injection. Forty-eight hours after QA administration, rotarod test was performed to evaluate motor coordination and balance. Fluoro-Jade C, Iba-1, and GFAP staining were used to evaluate neuronal cell death, microglia morphology, and astrocytes density, respectively, at this time point. Levels of cytokines and neurotrophic factors were measured by ELISA and Cytometric Bead Array 8 h after QA injection. Striatal synaptosomes were used to evaluate the release of glutamate. RESULTS: We first demonstrated that rapamycin prevented the motor impairment induced by QA. Moreover, mTOR inhibition also reduced the neurodegeneration and the production of interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α induced by excitotoxic stimulus. The lowest dose of rapamycin also increased the production of IL-10 and prevented the reduction of astrocyte density induced by QA. By using an in vitro approach, we demonstrated that rapamycin differently alters the release of glutamate from striatal synaptosomes induced by QA, reducing or enhancing the release of this neurotransmitter at low or high concentrations, respectively. CONCLUSION: Taken together, these data demonstrated a protective effect of rapamycin against an excitotoxic stimulus. Therefore, this study provides new evidence of the detrimental role of mTOR in neurodegeneration, which might represent an important target for the treatment of neurodegenerative diseases. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12974-017-0793-x) contains supplementary material, which is available to authorized users
Spontaneous Vertebrovertebral Arteriovenous Fistula Treated by Steel Coil Embolization: Case Report
Comparison of the Tzanck test and polymerase chain reaction in the diagnosis of cutaneous herpes simplex and varicella zoster virus infections
Evaluating the Sensitivity of Biomass Feedstocks to Producer Gas Composition Using Stoichiometric Equilibrium Model
'You want the right amount of oversight' : interviews with data access committee members and experts on genomic data access
Purpose: Genomic data sharing is vital for optimizing the use of public-funded research data. Data access committees (DACs) have been introduced as a core component of governance in controlled access models. However, the tasks, structure, and functionality of DACs often remain unstudied. This article investigates the role and adequacy of DACs in access reviews from the perspective of DAC members and experts.
Methods: Twenty semi-structured interviews were conducted with both DAC members engaged in genomic data sharing via controlled-access databases and experts in the field.
Results: The respondents indicated that protecting the privacy of data subjects along with recognition of data producers' efforts are the main underlying reasons of access review and the controlled-access model. In reviewing the ethical basis and the scientific aspects of access requests, tools and mechanisms such as consent forms, data access agreements, and guidelines have been used. Nevertheless, DAC members and experts identified shortcomings associated with current approaches that may adversely impact the effectiveness and efficiency of access review.
Conclusion: The identified shortcomings of current approaches to access review could be addressed via complementary mechanisms and alternative models of data sharing to facilitate access to data sets in a responsible fashion
