Observations on elephant habitat and conservation of elephants in Eritrea

Confined to a small area of about 100 by 50 km, the elephants in Eritrea are one of the northernmost populations in Africa. They are vulnerable because they appear to be genetically isolated and their small number may renders them a non-viable population. During 1997-1999 we visited elephant habitat in the Zoba Gash-Barka in southwest Eritrea to study problems of encroaching human populations on elephant habitat. This situation was described in the preceding article by Hagos Yohannes who is proposing to translocate farmers — with their willing cooperation — from the conflict zone to non-wildlife designated areas. Should such an ambitious plan be too difficult to execute, an alternative solution is being considered

Complete Mitochondrial Genome and Phylogeny of Pleistocene MammothMammuthus primigenius

Phylogenetic relationships between the extinct woolly mammoth(Mammuthus primigenius), and the Asian(Elephas maximus) and African savanna(Loxodonta africana) elephants remain unresolved. Here, we report the sequence of the complete mitochondrial genome (16,842 base pairs) of a woolly mammoth extracted from permafrost-preserved remains from the Pleistocene epoch—the oldest mitochondrial genome sequence determined to date. We demonstrate that well-preserved mitochondrial genome fragments, as long as ~1,600–1700 base pairs, can be retrieved from pre-Holocene remains of an extinct species. Phylogenetic reconstruction of the Elephantinae clade suggests thatM. primigenius andE. maximus are sister species that diverged soon after their common ancestor split from theL. africana lineage. Low nucleotide diversity found between independently determined mitochondrial genomic sequences of woolly mammoths separated geographically and in time suggests that north-eastern Siberia was occupied by a relatively homogeneous population ofM. primigenius throughout the late Pleistocene

Salmonella enterica biofilm-mediated dispersal by nitric oxide donors in association with cellulose nanocrystal hydrogels

Protected by extracellular polymers, microbes within biofilms are significantly more resistant to disinfectants. Current research has been instrumental in identifying nitric oxide donors and hydrogels as potential disinfectant additives. Nitric oxide (NO) donors are considered a very promising molecule as biofilm dispersal agents and hydrogels have recently attracted a lot of interest due to their biocompatible properties and ability to form stable thin films. When the NO donor MAHMA NONOate was dissolved in phosphate saline buffer, it was able to reduce the biomass of well-established biofilms up to 15% for at least 24 h of contact time. Encapsulation of MAHMA NONOate and molsidomine within a hydrogel composed of cellulose nanocrystals (CNC) has shown a synergistic effect in dispersing well-established biofilms: after 2 h of exposure, moderate but significant dispersion was measured. After 6 h of exposure, the number of cells transitioning from the biofilm to the planktonic state was up to 0.6 log higher when compared with non-treated biofilms. To further explore the transport processes of NO donors within hydrogels, we measured the nitric oxide flux from gels, at 25°C for a composite of 0.1 µM MAHMA NONOate–CNC. Nitric oxide diffuses up to 500 µm from the hydrogel surface, with flux decreasing according to Fick’s law. 60% of NO was released from the hydrogel composite during the first 23 min. These data suggest that the combined treatments with nitric oxide donor and hydrogels may allow for new sustainable cleaning strategies

Clusters of Nucleotide Substitutions and Insertion/Deletion Mutations Are Associated with Repeat Sequences

The authors propose that short repeat sequences may play an important role in causing the pervasive clustering of mutations across diverse genomes from prokaryotes to humans

SSeCKS/Gravin/AKAP12 attenuates expression of proliferative and angiogenic genes during suppression of v-Src-induced oncogenesis

BACKGROUND: SSeCKS is a major protein kinase C substrate with kinase scaffolding and metastasis-suppressor activity whose expression is severely downregulated in Src- and Ras-transformed fibroblast and epithelial cells and in human prostate, breast, and gastric cancers. We previously used NIH3T3 cells with tetracycline-regulated SSeCKS expression plus a temperature-sensitive v-Src allele to show that SSeCKS re-expression inhibited parameters of v-Src-induced oncogenic growth without attenuating in vivo Src kinase activity. METHODS: We use cDNA microarrays and semi-quantitative RT-PCR analysis to identify changes in gene expression correlating with i) SSeCKS expression in the absence of v-Src activity, ii) activation of v-Src activity alone, and iii) SSeCKS re-expression in the presence of active v-Src. RESULTS: SSeCKS re-expression resulted in the attenuation of critical Src-induced proliferative and pro-angiogenic gene expression including Afp, Hif-1α, Cdc20a and Pdgfr-β, and conversely, SSeCKS induced several cell cycle regulatory genes such as Ptpn11, Gadd45a, Ptplad1, Cdkn2d (p19), and Rbbp7. CONCLUSION: Our data provide further evidence that SSeCKS can suppress Src-induced oncogenesis by modulating gene expression downstream of Src kinase activity

An Inverse Method to Obtain Porosity, Fibre Diameterand Density of Fibrous Sound Absorbing Materials

Characterization of sound absorbing materials is essential to predict its acoustic behaviour. The most commonly used models to do so consider the flow resistivity, porosity, and average fibre diameter as parameters to determine the acoustic impedance and sound absorbing coefficient. Besides direct experimental techniques, numerical approaches appear to be an alternative to estimate the material's parameters. In this work an inverse numerical method to obtain some parameters of a fibrous material is presented. Using measurements of the normal incidence sound absorption coefficient and then using the model proposed by Voronina, subsequent application of basic minimization techniques allows one to obtain the porosity, average fibre diameter and density of a sound absorbing material. The numerical results agree fairly well with the experimental data.This work has been supported by the Ministerio de Educacion y Ciencia-D.G. Investigacion (BIA2007-68098-C02-01 and BIA2007-68098-C02-02) and also from the Spanish Ministry of Foreign Affairs and Cooperation through the Inter-University and Scientific Research Cooperation Program (A/023748/09).Alba Fernández, J.; Rey Tormos, RMD.; Ramis Soriano, J.; Arenas, JP. (2011). An Inverse Method to Obtain Porosity, Fibre Diameterand Density of Fibrous Sound Absorbing Materials. Archives of Acoustics. 36(3):561-574. https://doi.org/10.2478/v10168-011-0040-xS561574363Allard, J., & Champoux, Y. (1992). New empirical equations for sound propagation in rigid frame fibrous materials. The Journal of the Acoustical Society of America, 91(6), 3346-3353. doi:10.1121/1.402824Attenborough, K. (1983). Acoustical characteristics of rigid fibrous absorbents and granular materials. The Journal of the Acoustical Society of America, 73(3), 785-799. doi:10.1121/1.389045Bies, D. A., & Hansen, C. H. (1980). Flow resistance information for acoustical design. Applied Acoustics, 13(5), 357-391. doi:10.1016/0003-682x(80)90002-xChampoux, Y., Stinson, M. R., & Daigle, G. A. (1991). Air‐based system for the measurement of porosity. The Journal of the Acoustical Society of America, 89(2), 910-916. doi:10.1121/1.1894653Crocker, M. J., & Arenas, J. P. (s. f.). Use of Sound-Absorbing Materials. Handbook of Noise and Vibration Control, 696-713. doi:10.1002/9780470209707.ch57Delany, M. E., & Bazley, E. N. (1970). Acoustical properties of fibrous absorbent materials. Applied Acoustics, 3(2), 105-116. doi:10.1016/0003-682x(70)90031-9Dunn, I. P., & Davern, W. A. (1986). Calculation of acoustic impedance of multi-layer absorbers. Applied Acoustics, 19(5), 321-334. doi:10.1016/0003-682x(86)90044-7Fellah, Z. E. A., Berger, S., Lauriks, W., Depollier, C., Aristégui, C., & Chapelon, J.-Y. (2003). Measuring the porosity and the tortuosity of porous materials via reflected waves at oblique incidence. The Journal of the Acoustical Society of America, 113(5), 2424-2433. doi:10.1121/1.1567275Fellah, Z. E. A., Berger, S., Lauriks, W., Depollier, C., & Fellah, M. (2003). Measuring the porosity of porous materials having a rigid frame via reflected waves: A time domain analysis with fractional derivatives. Journal of Applied Physics, 93(1), 296-303. doi:10.1063/1.1524025Fellah, Z. E. A., Berger, S., Lauriks, W., Depollier, C., Trompette, P., & Chapelon, J. Y. (2003). Ultrasonic measurement of the porosity and tortuosity of air-saturated random packings of beads. Journal of Applied Physics, 93(11), 9352-9359. doi:10.1063/1.1572191Fellah, Z. E. A., Mitri, F. G., Fellah, M., Ogam, E., & Depollier, C. (2007). Ultrasonic characterization of porous absorbing materials: Inverse problem. Journal of Sound and Vibration, 302(4-5), 746-759. doi:10.1016/j.jsv.2006.12.007Garai, M., & Pompoli, F. (2005). A simple empirical model of polyester fibre materials for acoustical applications. Applied Acoustics, 66(12), 1383-1398. doi:10.1016/j.apacoust.2005.04.008ISO (1998), 10534-2:1998. Acoustics - determination of sound absorption coefficient and impedance in impedance tubes - Part 2: transfer-function method, International Organization for Standardization, Geneva.Miki, Y. (1990). Acoustical properties of porous materials. Modifications of Delany-Bazley models. Journal of the Acoustical Society of Japan (E), 11(1), 19-24. doi:10.1250/ast.11.19Miki, Y. (1990). Acoustical properties of porous materials. Generalizations of empirical models. Journal of the Acoustical Society of Japan (E), 11(1), 25-28. doi:10.1250/ast.11.25Ramis, J., Alba, J., Del Rey, R., Escuder, E., & Sanchís, V. J. (2010). Nuevos materiales absorbentes acústicos basados en fibra de kenaf. Materiales de Construcción, 60(299), 133-143. doi:10.3989/mc.2010.50809Shoshani, Y., & Yakubov, Y. (2000). Numerical assessment of maximal absorption coefficients for nonwoven fiberwebs. Applied Acoustics, 59(1), 77-87. doi:10.1016/s0003-682x(99)00015-8Umnova, O., Attenborough, K., Shin, H.-C., & Cummings, A. (2005). Deduction of tortuosity and porosity from acoustic reflection and transmission measurements on thick samples of rigid-porous materials. Applied Acoustics, 66(6), 607-624. doi:10.1016/j.apacoust.2004.02.005Voronina, N. (1994). Acoustic properties of fibrous materials. Applied Acoustics, 42(2), 165-174. doi:10.1016/0003-682x(94)90005-1Voronina, N. (1996). Improved empirical model of sound propagation through a fibrous material. Applied Acoustics, 48(2), 121-132. doi:10.1016/0003-682x(95)00055-eVoronina, N. (1998). An empirical model for elastic porous materials. Applied Acoustics, 55(1), 67-83. doi:10.1016/s0003-682x(97)00098-4Voronina, N. (1999). An empirical model for rigid-frame porous materials with low porosity. Applied Acoustics, 58(3), 295-304. doi:10.1016/s0003-682x(98)00076-0Voronina, N. ., & Horoshenkov, K. . (2003). A new empirical model for the acoustic properties of loose granular media. Applied Acoustics, 64(4), 415-432. doi:10.1016/s0003-682x(02)00105-6Wang, X., Eisenbrey, J., Zeitz, M., & Sun, J. Q. (2004). Multi-stage regression analysis of acoustical properties of polyurethane foams. Journal of Sound and Vibration, 273(4-5), 1109-1117. doi:10.1016/j.jsv.2003.09.039Wilson, D. K. (1997). Simple, relaxational models for the acoustical properties of porous media. Applied Acoustics, 50(3), 171-188. doi:10.1016/s0003-682x(96)00048-

Polydatin, a natural precursor of resveratrol, induces β-Defensin production and reduces inflammatory response.

Interleukin-17 (IL-17) is a proinflammatory cytokine produced, although not exclusively, by T helper 17 recently identified as a distinct T helper lineage mediating tissue inflammation. IL-17 is known to be involved in a number of chronic disorders although the mechanisms regulating its production in inflammatory disease are still unclear. The beneficial properties of the polyphenolic compound resveratrol including its anti-inflammatory, antioxidant, and antitumor effects, its role in the aging process and in the prevention of heart and neurodegenerative diseases are well-known. In addition, derivatives of resveratrol, including glucosylated molecules as polydatin have been linked to similar beneficial effects. We have investigated the effects of resveratrol and polydatin on the in vitro production of IL-17 in a model of inflammation in vitro. The results obtained by activated human peripheral blood mononuclear cells, stimulated with anti-CD3/anti-CD28 monoclonal antibodies and treated with these polyphenolic compounds at different concentrations show that both decrease IL-17 production in a concentration-dependent manner. This study confirms the anti-inflammatory activity of resveratrol and its derivatives and suggests a potential clinical relevance in the therapy of inflammatory diseases