Bianchi I Model: An Alternative Way To Model The Presentday Universe

Although the new era of high precision cosmology of the cosmic microwave background (CMB) radiation improves our knowledge to understand the infant as well as the presentday Universe, it also leads us to question the main assumption of the exact isotropy of the CMB. There are two pieces of observational evidence that hint towards there being no exact isotropy. These are first the existence of small anisotropy deviations from isotropy of the CMB radiation and second, the presence of large angle anomalies, although the existence of these anomalies is currently a huge matter of debate. These hints are particularly important since isotropy is one of the two main postulates of the Copernican principle on which the FRW models are built. This almost isotropic CMB radiation implies that the universe is almost a FRW universe, as is proved by previous studies. Assuming the matter component forms the deviations from isotropy in the CMB density fluctuations when matter and radiation decouples, we here attempt to find possible constraints on the FRW type scale and Hubble parameter by using the Bianchi type I (BI) anisotropic model which is asymptotically equivalent to the standard FRW. To obtain constraints on such an anisotropic model, we derive average and late-time shear values that come from the anisotropy upper limits of the recent Planck data based on a model independent shear parameter of Maartens et al. (1995a,b) and from the theoretical consistency relation. These constraints lead us to obtain a BI model which becomes an almost-FRW model in time, and which is consistent with the latest observational data of the CMB.Comment: 16 pages, 4 figures, accepted in MNRA

Use of an antibiotic growth promoter and two herbal natural feed additives with and without exogenous enzymes in wheat based broiler diets

No Abstract. South African Journal of Animal Science Vol. 35 (1) 2005: pp.61-7

Cytotoxic Effect of Turkish Propolis on Liver, Colon, Breast, Cervix and Prostate Cancer Cell Lines

Purpose: To investigate the total polyphenolic and flavonoid contents, antioxidant power and cytotoxic activity of ethanol extracts of Turkish propolis (EEP).Methods: The total polyphenolic and flavonoid contents of EEP were determined by spectrometric methods. Antioxidant power and cytotoxic activity of EEP were evaluated using ferric reducing antioxidant power (FRAP) and MTT assays, respectively.Results: The total polyphenolic and flavonoid contents, and FRAP value of EEP were 124.6 ± 1.5 mg gallic acid/g sample dry weight , 42.0 ± 0.8 mg quercetin/g sample dry weight and 311.0 ± 2.5 mg trolox/g sample dry weight, respectively. EEP exhibited powerful cytotoxic effects against the five human cancer cell lines. The highest cytotoxic activity of Turkish EEP was demonstrated on PC-3 cell line (IC50 = 20.7±3.4 μg/mL).Conclusion: The results demonstrate that EEP is a good source of antioxidant and a natural antitumor agent capable  of reducing cancer cell proliferation.Keywords: Propolis, Polyphenols, Cytotoxic effect, Cancer cell lines, Antioxidant activity Tropical Journal of  Pharmaceutical Research is indexed by Science Citation Index (SciSearch)

A practical probabilistic earthquake hazard analysis tool: case study Marmara region

Earthquakes have a damaging impact on the economic welfare and resilience of communities, particularly in developing countries. Seismic hazard assessment is the first step towards performing prevention, preparedness, and response or recovery actions to reduce seismic risk. This paper presents a computation tool for predicting the seismic hazard at the macro level as a part of a comprehensive multi-hazard framework on earthquake risk assessment. The probabilistic seismic hazard analysis (PSHA) procedure is based on the Monte-Carlo approach, and particular attention is paid to the definition of source zones assigned in the study area. Both Poisson and time dependent (renewal) models are adopted to quantify the effect of temporal dependencies between seismic events, while near-field rupture directivity effects are also taken into account. Marmara region in Turkey is selected as a case study area to perform a new seismic hazard analysis and verify the accuracy of the proposed tool. The results show good agreement with results from the recent SHARE project and the latest Turkish Earthquake Design code hazard maps. This confirms that the proposed PSHA method can be an attractive alternative to the direct integration based methods due to its practicality and powerful handling of uncertainties

Hunting for origins of migraine pain: cluster analysis of spontaneous and capsaicin-induced firing in meningeal trigeminal nerve fibers

International audienceTrigeminal nerves in meninges are implicated in generation of nociceptive firing underlying migraine pain. However, the neurochemical mechanisms of nociceptive firing in meningeal trigeminal nerves are little understood. In this study, using suction electrode recordings from peripheral branches of the trigeminal nerve in isolated rat meninges, we analyzed spontaneous and capsaicin-induced orthodromic spiking activity. In control, biphasic single spikes with variable amplitude and shapes were observed. Application of the transient receptor potential vanilloid 1 (TRPV1) agonist capsaicin to meninges dramatically increased firing whereas the amplitudes and shapes of spikes remained essentially unchanged. This effect was antagonized by the specific TRPV1 antagonist capsazepine. Using the clustering approach, several groups of uniform spikes (clusters) were identified. The clustering approach combined with capsaicin application allowed us to detect and to distinguish "responder" (65%) from "non responder" clusters (35%). Notably, responders fired spikes at frequencies exceeding 10 Hz, high enough to provide postsynaptic temporal summation of excitation at brainstem and spinal cord level. Almost all spikes were suppressed by tetrodotoxin (TTX) suggesting an involvement of the I I X-sensitive sodium channels in nociceptive signaling at the peripheral branches of trigeminal neurons. Our analysis also identified transient (desensitizing) and long-lasting (slowly desensitizing) responses to the continuous application of capsaicin. Thus, the persistent activation of nociceptors in capsaicin-sensitive nerve fibers shown here may be involved in trigeminal pain signaling and plasticity along with the release of migraine-related neuropeptides from TRPV1 positive neurons. Furthermore, cluster analysis could be widely used to characterize the temporal and neurochemical profiles of other pain transducers likely implicated in migraine

A One-Piece Lunar Regolith Bag Garage Prototype

Shelter structures on the moon, even in early phases of exploration, should incorporate lunar materials as much as possible. This Technical Memorandum details the design and construction of a prototype for a one-piece regolith bag unpressurized garage concept and a materials testing program to investigate six candidate fabrics to learn how they might perform in the lunar environment. The conceptualization was that a lightweight fabric form be launched from Earth and landed on the lunar surface to be robotically filled with raw lunar regolith. Regolith bag fabric candidates included: Vectran(TM), Nextel(TM), Gore PTFE Fabric(TM), Zylon(TM), Twaron(TM), and Nomex(TM). Tensile (including post radiation exposure), fold, abrasion, and hypervelocity impact testing were performed under ambient conditions, and also performed under cold and elevated temperatures. In some cases, Johnson Space Center lunar simulant (JSC-1) was used in conjunction with testing. A series of preliminary structures was constructed during final prototype design based on the principles of the classic masonry arch. The prototype was constructed of Kevlar(TM) and filled with vermiculite. The structure is free-standing, but has not yet been load tested. Future plans would be to construct higher fidelity prototypes and to conduct appropriate tests of the structure

Cylindrically Symmetric Inhomogeneous Universes with a Cloud of Strings

Cylindrically symmetric inhomogeneous string cosmological models are investigated in presence of string fluid as a source of matter. To get the three types of exact solutions of Einstein's field equations we assume $A = f(x)k(t)$, $B = g(x)\ell(t)$ and $C = h(x)\ell(t)$. Some physical and geometric aspects of the models are discussed.Comment: 9 page

Endogenous Syngap1 Alpha Splice Forms Promote Cognitive Function and Seizure Protection

Altres ajuts: NIH grants from the National Institute of Mental Health (MH096847, MH108408, MH115005, MH113949, MH105400); National Institute for Neurological Disorders and Stroke (NS064079); Eunice Kennedy Shriver National Institute of Child Health and Human Development (HD089491); National Institute for Drug Abuse (DA034116, DA036376); Autism Speaks Weatherstone Pre-Doctoral fellowship (10646); Training fellowship from the Leon and Friends Charitable Foundation.Loss-of-function variants in SYNGAP1 cause a developmental encephalopathy defined by cognitive impairment, autistic features, and epilepsy. SYNGAP1 splicing leads to expression of distinct functional protein isoforms. Splicing imparts multiple cellular functions of SynGAP proteins through coding of distinct C-terminal motifs. However, it remains unknown how these different splice sequences function in vivo to regulate neuronal function and behavior. Reduced expression of SynGAP-α1/2 C-terminal splice variants in mice caused severe phenotypes, including reduced survival, impaired learning, and reduced seizure latency. In contrast, upregulation of α1/2 expression improved learning and increased seizure latency. Mice expressing α1-specific mutations, which disrupted SynGAP cellular functions without altering protein expression, promoted seizure, disrupted synapse plasticity, and impaired learning. These findings demonstrate that endogenous SynGAP isoforms with α1/2 spliced sequences promote cognitive function and impart seizure protection. Regulation of SynGAP-α expression or function may be a viable therapeutic strategy to broadly improve cognitive function and mitigate seizure

Nucleotide homeostasis and purinergic nociceptive signaling in rat meninges in migraine-like conditions

© 2016, Springer Science+Business Media Dordrecht.Extracellular ATP is suspected to contribute to migraine pain but regulatory mechanisms controlling pro-nociceptive purinergic mechanisms in the meninges remain unknown. We studied the peculiarities of metabolic and signaling pathways of ATP and its downstream metabolites in rat meninges and in cultured trigeminal cells exposed to the migraine mediator calcitonin gene-related peptide (CGRP). Under resting conditions, meningeal ATP and ADP remained at low nanomolar levels, whereas extracellular AMP and adenosine concentrations were one-two orders higher. CGRP increased ATP and ADP levels in meninges and trigeminal cultures and reduced adenosine concentration in trigeminal cells. Degradation rates for exogenous nucleotides remained similar in control and CGRP-treated meninges, indicating that CGRP triggers nucleotide release without affecting nucleotide-inactivating pathways. Lead nitrate-based enzyme histochemistry of whole mount meninges revealed the presence of high ATPase, ADPase, and AMPase activities, primarily localized in the medial meningeal artery. ATP and ADP induced large intracellular Ca2+ transients both in neurons and in glial cells whereas AMP and adenosine were ineffective. In trigeminal glia, ATP partially operated via P2X7 receptors. ATP, but not other nucleotides, activated nociceptive spikes in meningeal trigeminal nerve fibers providing a rationale for high degradation rate of pro-nociceptive ATP. Pro-nociceptive effect of ATP in meningeal nerves was reproduced by α,β-meATP operating via P2X3 receptors. Collectively, extracellular ATP, which level is controlled by CGRP, can persistently activate trigeminal nerves in meninges which considered as the origin site of migraine headache. These data are consistent with the purinergic hypothesis of migraine pain and suggest new targets against trigeminal pain