155 research outputs found
Chemical compositions and mosquito repellency of essential oils from Artabotrys hexapetalus and Artabotrys rupestris
The two Tanzanian Artabotrys species were investigated to establish the chemical composition and mosquito repellent properties of their essential oils. Hydrodistillation of leaves and stem bark of Artabotrys hexapetalus (L.f.) (Annonaceae) and stem bark of Artabotrys rupestris Diels (Annonaceae) gave essential oils which were analyzed by Gas Chromatography – Mass Spectrometry (GC-MS). While the oil from the stem bark of A. hexapetalus contained high amount of β-caryophyllene oxide, the oil from the leaves had both β- caryophyllene oxide and 11-hexadcyn-1-ol as the main components. The oil from the root barks of A. rupestris contained large amount of 6-(p-tolyl)-2-methyl-2-heptanol and (-)-spathulenol. β-Caryophyllene oxide, cadinol, cubenol, (-)-spathulenol and 7-methyl-4-methylene-1-(1-methylethyl)-naphthalene were identified as common constituents of the essential oils from the two plant species investigated. On evaluation for mosquito repellency, the essential oil from the leaves of A. hexapetalus was found to exhibit strong activity with RC50 = 1.81×10-5 mg/cm2 and 2.79×10-5 mg/cm2 for the first and the second fractions, respectively against female Anopheles gambiae s.s. mosquitoes. The repellency activity of essential oil from leaves were significantly higher than from stem bark, but less than that of the standard citronella oil used (RC50 = 4.1×10-6 mg/cm2). The observed high mosquito repellent activity for the essential oil fractions from A. hexapetalus could be attributed to the presence of β-caryophyllene oxide.Keywords: Essential oils, mosquito repellent properties, Annonaceae, β-caryophyllene oxide, cadinol, cubenol
JLab Measurements of the 3He Form Factors at Large Momentum Transfers
The charge and magnetic form factors, FC and FM, of 3He have been extracted
in the kinematic range 25 fm-2 < Q2 < 61 fm-2 from elastic electron scattering
by detecting 3He recoil nuclei and electrons in coincidence with the High
Resolution Spectrometers of the Hall A Facility at Jefferson Lab. The
measurements are indicative of a second diffraction minimum for the magnetic
form factor, which was predicted in the Q2 range of this experiment, and of a
continuing diffractive structure for the charge form factor. The data are in
qualitative agreement with theoretical calculations based on realistic
interactions and accurate methods to solve the three-body nuclear problem
Corrosion Resistance of AA6063-Type Al-Mg-Si Alloy by Silicon Carbide in Sodium Chloride Solution for Marine Application
The present work focused on corrosion inhibition of
AA6063 type Al-Mg-Si alloy in sodium chloride (NaCl) solution
with a silicon carbide inhibitor, using the potentiodynamic
electrochemical method. The aluminium alloy surface morphology
was examined, in the as-received and as-corroded in the
un-inhibited state, with scanning electron microscopy equipped
with energy dispersive spectroscopy (SEM-EDS). The results
obtained via linear polarization indicated a high corrosion potential
for the unprotected as-received alloy. Equally, inhibition efficiency
as high as 98.82% at 10.0 g/v silicon carbide addition was obtained
with increased polarization resistance (Rp), while the current
density reduced significantly for inhibited samples compared to the
un-inhibited aluminium alloy. The adsorption mechanism of the
inhibitor aluminium alloy follows the Langmuir adsorption
isotherm. This shows that the corrosion rate of aluminium alloy
with silicon carbide in NaCl environment decreased significantly
with addition of the inhibito
Observation of an Exotic Baryon in Exclusive Photoproduction from the Deuteron
In an exclusive measurement of the reaction , a
narrow peak that can be attributed to an exotic baryon with strangeness
is seen in the invariant mass spectrum. The peak is at
GeV/c with a measured width of 0.021 GeV/c FWHM, which is largely
determined by experimental mass resolution. The statistical significance of the
peak is . The mass and width of the observed peak are
consistent with recent reports of a narrow baryon by other experimental
groups.Comment: 5 pages, 5 figure
Display of probability densities for data from a continuous distribution
Based on cumulative distribution functions, Fourier series expansion and
Kolmogorov tests, we present a simple method to display probability densities
for data drawn from a continuous distribution. It is often more efficient than
using histograms.Comment: 5 pages, 4 figures, presented at Computer Simulation Studies XXIV,
Athens, GA, 201
Impact of seminal trace element and glutathione levels on semen quality of Tunisian infertile men
<p>Abstract</p> <p>Background</p> <p>Growing evidence indicates that oxidative stress can be a primary cause of male infertility. Non-enzymatic antioxidants play an important protective role against oxidative damages and lipid peroxidation. Human seminal plasma is a natural reservoir of antioxidants. The aim of this study was to determine glutathione (GSH) concentrations, trace element levels (zinc and selenium) and the lipid peroxidation end product, malondialdehyde (MDA), in the seminal plasma of men with different fertility potentials.</p> <p>Methods</p> <p>Semen samples from 60 fertile men (normozoospermics) and 190 infertile patients (74 asthenozoospermics, 56 oligozoospermics, and 60 teratozoospermics) were analyzed for physical and biochemical parameters. Zinc (Zn) and selenium (Se) levels were estimated by atomic absorption spectrophotometry. Total GSH (GSHt), oxidized GSH (GSSG), reduced GSH (GSHr) and MDA concentrations were measured spectrophotometrically.</p> <p>Results</p> <p>Zn and Se concentrations in seminal plasma of normozoospermics were more elevated than the three abnormal groups. Nevertheless, only the Zn showed significant differences. On the other hand, Zn showed positive and significant correlations with sperm motility (P = 0.03, r = 0.29) and count (P < 0.01, r = 0.49); however Se was significantly correlated only with sperm motility (P < 0.01, r = 0.36). GSHt, GSSG and GSHr were significantly higher in normozoospermics than in abnormal groups. We noted a significant association between seminal GSHt and sperm motility (P = 0.03). GSSG was highly correlated to sperm motility (P < 0.001) and negatively associated to abnormal morphology (P < 0.001). GSHr was significantly associated to total sperm motility (P < 0.001) and sperm count (P = 0.01). MDA levels were significantly higher in the three abnormal groups than in normozoospermics. Rates of seminal MDA were negatively associated to sperm motility (P < 0.01; r = -0.24) and sperm concentration (P = 0.003; r = -0.35) Meanwhile, there is a positive correlation between seminal lipid peroxidation and the percentage of abnormal morphology (P = 0.008).</p> <p>Conclusions</p> <p>This report revealed that decreased seminal GSH and trace element deficiencies are implicated in low sperm quality and may be an important indirect biomarker of idiopathic male infertility. Our results sustain that the evaluation of seminal antioxidant status in infertile men is necessary and can be helpful in fertility assessment from early stages.</p
Usefulness of C-reactive protein as a marker of early post-infarct left ventricular systolic dysfunction
Objective To assess the usefulness of in-hospital measurement
of C-reactive protein (CRP) concentration in
comparison to well-established risk factors as a marker of
post-infarct left ventricular systolic dysfunction (LVSD) at
discharge.
Materials and methods Two hundred and four consecutive
patients with ST-segment-elevation myocardial
infarction (STEMI) were prospectively enrolled into the
study. CRP plasma concentrations were measured before
reperfusion, 24 h after admission and at discharge with an
ultra-sensitive latex immunoassay.
Results CRP concentration increased significantly during
the first 24 h of hospitalization (2.4 ± 1.9 vs. 15.7 ± 17.0
mg/L; p\0.001) and persisted elevated at discharge
(14.7 ± 14.7 mg/L), mainly in 57 patients with LVSD
(2.4 ± 1.8 vs. 25.0 ± 23.4 mg/L; p\0.001; CRP at discharge
21.9 ± 18.6 mg/L). The prevalence of LVSD was
significantly increased across increasing tertiles of CRP
concentration both at 24 h after admission (13.2 vs. 19.1
vs. 51.5 %; p\0.0001) and at discharge (14.7 vs. 23.5 vs.
45.6 %; p\0.0001). Multivariate analysis demonstrated
CRP concentration at discharge to be an independent
marker of early LVSD (odds ratio of 1.38 for a 10 mg/L
increase, 95 % confidence interval 1.01–1.87; p\0.04).
Conclusion Measurement of CRP plasma concentration
at discharge may be useful as a marker of early LVSD in
patients after a first STEMI
Altering a Histone H3K4 Methylation Pathway in Glomerular Podocytes Promotes a Chronic Disease Phenotype
Methylation of specific lysine residues in core histone proteins is essential for embryonic development and can impart active and inactive epigenetic marks on chromatin domains. The ubiquitous nuclear protein PTIP is encoded by the Paxip1 gene and is an essential component of a histone H3 lysine 4 (H3K4) methyltransferase complex conserved in metazoans. In order to determine if PTIP and its associated complexes are necessary for maintaining stable gene expression patterns in a terminally differentiated, non-dividing cell, we conditionally deleted PTIP in glomerular podocytes in mice. Renal development and function were not impaired in young mice. However, older animals progressively exhibited proteinuria and podocyte ultra structural defects similar to chronic glomerular disease. Loss of PTIP resulted in subtle changes in gene expression patterns prior to the onset of a renal disease phenotype. Chromatin immunoprecipitation showed a loss of PTIP binding and lower H3K4 methylation at the Ntrk3 (neurotrophic tyrosine kinase receptor, type 3) locus, whose expression was significantly reduced and whose function may be essential for podocyte foot process patterning. These data demonstrate that alterations or mutations in an epigenetic regulatory pathway can alter the phenotypes of differentiated cells and lead to a chronic disease state
Diversity, distribution and conservation of the terrestrial reptiles of Oman (Sauropsida, Squamata)
All authors:
Salvador Carranza ,
Meritxell Xipell,
Pedro Tarroso,
Andrew Gardner,
Edwin Nicholas Arnold,
Michael D. Robinson,
Marc Simó-Riudalbas,
Raquel Vasconcelos,
Philip de Pous,
Fèlix Amat,
Jiří Šmíd,
Roberto Sindaco,
Margarita Metallinou †,
Johannes Els,
Juan Manuel Pleguezuelos,
Luis Machado,
David Donaire,
Gabriel Martínez,
Joan Garcia-Porta,
Tomáš Mazuch,
Thomas Wilms,
Jürgen Gebhart,
Javier Aznar,
Javier Gallego,
Bernd-Michael Zwanzig,
Daniel Fernández-Guiberteau,
Theodore Papenfuss,
Saleh Al Saadi,
Ali Alghafri,
Sultan Khalifa,
Hamed Al Farqani,
Salim Bait Bilal,
Iman Sulaiman Alazri,
Aziza Saud Al Adhoobi,
Zeyana Salim Al Omairi,
Mohammed Al Shariani,
Ali Al Kiyumi,
Thuraya Al Sariri,
Ahmed Said Al Shukaili,
Suleiman Nasser Al Akhzami.In the present work, we use an exceptional database including 5,359 records of 101 species of Oman’s terrestrial reptiles together with spatial tools to infer the spatial patterns of species richness and endemicity, to infer the habitat preference of each species and to better define conservation priorities, with especial focus on the effectiveness of the protected areas in preserving this unique arid fauna. Our results indicate that the sampling effort is not only remarkable from a taxonomic point of view, with multiple observations for most species, but also for the spatial coverage achieved. The observations are distributed almost continuously across the two-dimensional climatic space of Oman defined by the mean annual temperature and the total annual precipitation and across the Principal Component Analysis (PCA) of the multivariate climatic space and are well represented within 17 out of the 20 climatic clusters grouping 10% of the explained climatic variance defined by PC1 and PC2. Species richness is highest in the Hajar and Dhofar Mountains, two of the most biodiverse areas of the Arabian Peninsula, and endemic species richness is greatest in the Jebel Akhdar, the highest part of the Hajar Mountains. Oman’s 22 protected areas cover only 3.91% of the country, including within their limits 63.37% of terrestrial reptiles and 50% of all endemics. Our analyses show that large areas of the climatic space of Oman lie outside protected areas and that seven of the 20 climatic clusters are not protected at all. The results of the gap analysis indicate that most of the species are below the conservation target of 17% or even the less restrictive 12% of their total area within a protected area in order to be considered adequately protected. Therefore, an evaluation of the coverage of the current network of protected areas and the identification of priority protected areas for reptiles using reserve design algorithms are urgently needed. Our study also shows that more than half of the species are still pending of a definitive evaluation by the International Union for Conservation of Nature (IUCN).This work was funded by grants CGL2012-36970, CGL2015-70390-P from the Ministerio de Economía y Competitividad, Spain (cofunded by FEDER) to SC, the project Field study for the conservation of reptiles in Oman, Ministry of Environment and Climate Affairs, Oman (Ref: 22412027) to SC and grant 2014-SGR-1532 from the Secretaria d'Universitats i Recerca del Departament d'Economia i Coneixement de la Generalitat de Catalunya to SC. MSR is funded by a FPI grant from the Ministerio de Economía y Competitividad, Spain (BES-2013-064248); RV, PT and LM were funded by Fundação para a Ciência e Tecnologia (FCT) through post-doc grants (SFRH/BPD/79913/2011) to RV, (SFRH/BPD/93473/2013) to PT and PhD grant (SFRH/BD/89820/2012) to LM, financed by Programa Operacional Potencial Humano (POPH) – Quadro de Referência Estrategico Nacional (QREN) from the European Social Fund and Portuguese Ministerio da Educação e Ciência
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