Hydrothermal treatments of corn cob and hemicelluloses extraction

Corn cob samples were treated with water (autohydrolysis reaction) using a liquid to solid ratio of 10:1 w/w. The optimal condition for extraction of hemicelluloses was found at 185ºC for 30 min. This resulted in the release of 9.7% of hemicelluloses (% dry starting material), corresponding to the dissolution of 27.9% of the original hemicellulose. Chemical composition and physico-chemical properties of the samples were elucidated by a combination of sugar analyses and thermal analysis. The results showed that the treatment was effective on the extraction of hemicelluloses from corn cob and that the TGA analysis of xylan from birch wood was found to be initially degraded at about 220 ºC whereas hemicelluloses from corn cob would be degraded at about 225 ºC.Fundação para a Ciência e a Tecnologia (FCT).Erasmus Programme (Turkey)

Hemicelluloses fractions extraction of corn residue

Fundação para a Ciência e a Tecnologia (FCT)Erasmus Programm

Detailed spectral profile analysis of penicillin-induced epileptiform activity in anesthetized rats

Penicillin model is a widely used experimental model for epilepsy research. In the present study we aimed to portray a detailed spectral analysis of penicillin-induced epileptiform activity in comparison with basal brain activity in anesthetized Wistar rats. Male Wistar rats were anesthetized with i.p. urethane and connected to an electrocorticogram setup. After a short period of basal activity recording, epileptic focus was induced by injecting 400 IU/2 µl penicillin-G potassium into the left lateral ventricle while the cortical activity was continuously recorded. Basal activity, latent period and the penicillin-induced epileptiform activity periods were then analyzed using both conventional methods and spectral analysis. Spectral analyses were conducted by dividing the whole spectrum into different frequency bands including delta, theta (slow and fast), alpha-sigma, beta (1 and 2) and gamma (1 and 2) bands. Our results show that the most affected frequency bands were delta, theta, beta-2 and gamma-2 bands during the epileptiform activity and there were marked differences in terms of spectral densities between three investigated episodes (basal activity, latent period and epileptiform activity). Our results may help to analyze novel data obtained using similar experimental models and the simple analysis method described here can be used in similar studies to investigate the basic neuronal mechanism of this or other types of experimental epilepsies. © 2008 Elsevier B.V. All rights reserved.Ondokuz Mayis ÜniversitesiThis study was supported in part by Ondokuz Mayis University Research Fund

Further evidence for the role of nitric oxide in maternal aggression: effects of l-name on maternal aggression towards female intruders in wistar rats

It has been shown that nitric oxide (NO) increases aggression in male mice, whereas it decreases aggression in lactating female mice and prairie voles. It is also known that aggression can be exhibited at different levels in rodent species, strain or subtypes. The aims of this study were to investigate the proportion of aggressiveness in Wistar rats, the effect of intraperitoneally administered nonspecific nitric oxide synthase (NOS) inhibitor L-NAME (NG-nitro L-arginine methyl ester) on maternal aggression towards female intruders, and whether these effects are due to NO production or not. Rats were given saline intraperitoneally on the postpartum Day 2 and aggression levels were recorded. The same rats were given 60 mg/kg L-NAME or D-NAME (NG-nitro D-arginine methyl ester) on the postpartum Day 3 and their effects on aggression levels were compared to saline. While L-NAME administration did not cause any differences in the total number of aggressive behavior, aggression duration and aggression intensity, it reduced the proportion of animals showing aggressive behavior. In addition, the latency of the first aggression was significantly increased by L-NAME. In the D-NAME group, however, no significant change was found. Our results have shown that L-NAME reduces maternal aggression towards female intruders in Wistar rats through inhibition of NO production. These results suggest that the role of NO in offensive and defensive maternal aggression shares neural mechanisms. © 2009 Institute of Physiology v.v.i., Academy of Sciences of the Czech Republic, Prague, Czech Republic

The acquisition of impervious surface area from LANDSAT 8 satellite sensor data using urban indices: a comparative analysis

Rapid and irregular urbanization is an essential issue in terms of environmental assessment and management. The dynamics of landscape patterns should be observed and analyzed by local authorities for a sustainable environment. The aim of this study is to determine which spectral urban index, originated from old Landsat missions, represents impervious area better when new generation Earth observation satellite Landsat 8 data are used. Two datasets of Landsat 8, acquired on 2 September 2013 and 10 September 2016, were utilized to investigate the consistency of the results. In this study, commonly used urban indices namely normalized difference built-up index (NDBI), index-based built-up index (IBI), urban index (UI), and enhanced built-up and bareness index (EBBI) were utilized to extract impervious areas. The accuracy assessment of urban indices was conducted by comparing the results with pan-sharpened images, which were classified using maximum likelihood classification (MLC) method. The kappa values of MLC, IBI, NDBI, EBBI, and UI for 2013 dataset were 0.89, 0.79, 0.71, 0.59, and 0.49, respectively, and the kappa values of MLC, IBI, NDBI, EBBI, and UI for 2016 dataset were 0.90, 0.78, 0.70, 0.56, and 0.47, respectively. In addition, area information was extracted from indices and classified images, and the obtained outcomes showed that IBI presented better results than the other urban indices, and UI extracted impervious areas worse than the other indices in both selected cases. Consequently, Landsat 8 satellite data can be considered as an important source to extract and monitor impervious surfaces for the sustainable development of cities. © 2018, Springer International Publishing AG, part of Springer Nature

Effects of the calcium channel blocker nifedipine on monosynaptic reflexes

The effects of calcium channel blocker, nifedipine on spinal monosynaptic reflexes were investigated in spinal cats. Nifedipine was administrated-locally (10, 50, 100s μmol/l) and intraperitoneally (5; 10, 20 mg/kg). Adult cats (n=10), weighing 1.5-3 kg were anesthetized with ketamine (50 mg/kg, I.M.) and artificially ventilated. Animals were spinalized at C1 level. A laminectomy was performed in the lumbosacral region. The ventral and dorsal roots of segment L5 were isolated and a pouch of skin was formed at the site of the dissection, to allow the exposed tissues to be covered with liquid paraffin, which was kept at 38.5 ± 0.5°C with a heating pad. A polyethylene cannula was introduced into the left carotid artery to monitor blood pressure, which was kept above 100 mmHg. The dorsal root of segment L5 was placed on a silver-silver chloride wire electrode for stimulation through an isolating unit. The reflex potentials were recorded from the ipsilateral L5 ventral root, mounted on a silver-silver chloride wire electrode. Both systemic and local application of nifedipine produced a dose-dependent decrease in the amplitude of the monosynaptic reflexes (p < 0.05). Moreover, the latency of the monosynaptic reflexes was increased after administration of the drug (p < 0.005). These results show the presence of voltage-dependent calcium channels in the spinal cord and these channels may play an important role to regulate reflex respond