Optical Seeing at Sierra Negra

Optical seeing measurements carried out at Sierra Negra, the site of the Large Millimeter Telescope, are reported. The site, one of the highest peaks of Central Mexico, offers good coverage of Northern and Southern hemispheres and we have undertaken several campaigns to investigate the astronomical potential of the site in the optical. Here we report on our campaign aimed at establishing the seeing quality of the site. We present data of the first three campaigns of optical seeing monitoring covering from February 2000 to May 2002, carried out with a Differential Image Motion Monitor. The results clearly indicate a sub-arcsec seeing, better statistics during the dry season and no dependence with the time of night. We find no dependence of our results with the integration time used.Comment: Accepted for publication in the July 2003 issue of the PAS

The Structure, Kinematics and Physical Properties of the Molecular Gas in the Starburst Nucleus of NGC 253

We present 5.2" x 2.6" resolution interferometry of CO J=1-0 emission from the starburst galaxy NGC 253. The high spatial resolution of these new data, in combination with recent high resolution maps of 13CO, HCN and near-infrared emission, allow us for the first time to link unambiguously the gas properties in the central starburst of NGC 253 with its bar dynamics. We confirm that the star formation results from bar-driven gas flows as seen in "twin peaks" galaxies. Two distinct kinematic features are evident from the CO map and position-velocity diagram: a group of clouds rotating as a solid body about the kinematic center of the galaxy, and a more extended gas component associated with the near-infrared bar. We model the line intensities of CO, HCN and 13CO to infer the physical conditions of the gas in the nucleus of NGC 253. The results indicate increased volume densities around the radio nucleus in a twin-peaks morphology. Compared with the CO kinematics, the gas densities appear highest near the radius of a likely inner Linblad resonance, and slightly lead the bar minor axis. This result is similar to observations of the face-on, twin-peaks galaxy NGC 6951, and is consistent with models of starburst generation due to gas inflow along a bar.Comment: To appear in the ApJ, 28 pages, 12 figure file

Evaluation of the anti-pyretic potential of Orthosiphon stamineus Benth standardized extract.

The anti-pyretic activity of a standardized methanol/water (50/50) extract of Orthosiphon stamineus Benth. (SEOS) was investigated for its effect on normal body temperature and yeast-induced pyrexia in Sprague Dawley (SD) rats. The SEOS showed no effect on normal body temperature. Doses of 500 and 1000 mg/kg body weight of SEOS significantly reduced the yeast-induced elevation in body temperature. This effect persisted up to 4 h following the administration of the extract. The anti-pyretic effect of SEOS was comparable with that of paracetamol (acetaminophen in U.S) (150 mg/kg p.o.), a standard anti-pyretic agent. HPLC study revealed that rosmarinic acid, sinensetin, eupatorin and tetramethoxyflavone were present in SEOS in the amounts of 7.58 %, 0.2 %, 0.34 % and 0.24 % respectively. The LD 50 of the extract in rats was higher than 5000 mg/kg body weight. Therefore, the present study ascertained that SEOS possesses a significant anti-pyretic activity

Orthosiphon stamineus leaf extract protects against ethanol-induced gastropathy in rats

Orthosiphon stamineus Benth., which is used as a gastroprotective herbal remedy in Malaysia, was assessed for its anti-ulcerogenic activity against ethanol-induced ulcers in rats. Fifty percent methanol was used to extract the oven-dried O. stamineus leaves. The extract was then lyophilized with a rotary evaporator and freeze-dried. Oral administration of O. stamineus methanolic extract (OSME) (125, 250, 500, and 1,000mg/kg) was found to significantly decrease the ulcer index (P<.01, P<.001, P<.001, and P<.001, respectively). Histological study of a section of the rat stomach also showed a marked improvement in the gastric mucosal damage in groups receiving OSME. In order to further investigate the gastroprotective mechanism of OSME, mucus secretion and lipid peroxidation level were estimated in vitro and ex vivo. OSME exhibited dose-dependent stimulation of mucus secretion (r=0.718, P<.001) and inhibition of lipid peroxidation in rat gastric mucosal homogenates (both in vitro [r=0.819, P<.05] and ex vivo [r=0.981, P<.05]). It was concluded that the gastroprotective mechanism of OSME was partly due to its ability to inhibit lipid peroxidation and stimulate gastric mucus secretion

HPLC and anti-inflammatory studies of the flavonoid rich chloroform extract fraction of Orthosiphon stamineus leaves.

The aim of the present study was to verify the anti-inflammatory activity of Orthosiphon stamineus leaf extracts and to identify the active compound(s) contributing to its anti-inflammatory activity using a developed HPLC method. Active chloroform extract of O. stamineus was fractionated into three fractions using a dry flash column chromatography method. These three fractions were investigated for anti-peritoneal capillary permeability, in vitro nitric oxide scavenging activity, anti-inflammatory and nitric oxide (NO) inhibition using carrageenan-induced hind paw edema method. The flavonoid rich chloroform extract fraction (CF2) [containing sinensetin (2.86% w/w), eupatorin (5.05% w/w) and 3'-hydroxy-5,6,7,4'-tetramethoxyflavone (1.101% w/w)], significantly reduced rat hind paw edema, NO and decreased dye leakage to peritoneal cavity at p < 0.05. IC50 of in vitro NO scavenging of CF2 was 0.3 mg/mL. These results suggest that the anti-inflammatory properties of these CF2 may possibly be due to the presence of flavonoid compounds capable of affecting the NO pathway

Topical piroxicam in vitro release and in vivo anti-inflammatory and analgesic effects from palm oil esters-based nanocream

During recent years, there has been growing interest in use of topical vehicle systems to assist in drug permeation through the skin. Drugs of interest are usually those that are problematic when given orally, such as piroxicam, a highly effective anti-inflammatory, anti-pyretic, and analgesic, but with the adverse effect of causing gastrointestinal ulcers. The present study investigated the in vitro and in vivo pharmacodynamic activity of a newly synthesized palm oil esters (POEs)-based nanocream containing piroxicam for topical delivery

The Investigation of the Relationship Between Emotional Engagement and Creativity

Background - One of the most critical challenges in engineering education is improving students’ divergent thinking skills. Usually, we observe students’ fixating on only one single solution for engineering problems. However, their ability to think outside the box and provide alternative solutions should be developed. Research shows that engagement may foster the development of thoughts and boost creativity. Purpose/Hypothesis – Our aim was to investigate students’ engagement with tasks that inspire different facets of creativity (verbal, numeric, and visual). Considering the role of demographics in student engagement, we explored the relationship between their engagement level and demographic traits such as gender, major, age, grades (GPA), and the languages they know besides their native tongue. Design/Method - We utilized electrodermal activity (EDA) sensors, a well-documented proxy of emotional engagement, to measure students’ engagement level while performing tasks that inspire different facets of creativity (verbal, numeric, and visual). Due to the non-normal distribution of the data, non-parametric statistical tests were conducted considering engagement as a dependent variable and demographic traits as independent variables. Results - Statistically significant differences in students’ engagement when exposed to creativity inspired tasks were observed. However, no association between demographics and engagement levels were detected. Conclusions - The results of the study may support educators in designing the instructional materials considering creativity-inspired activities so that students’ engagement level can be increased. Further, results from this study can inform experimental designs, specifically participant selection, in engagement focused studies

EVALUACIÓN DEL POTENCIAL EÓLICO EN LA BAHÍA DE CHETUMAL (EVALUATION OF THE WIND POTENTIAL IN CHETUMAL BAY)

Resumen El potencial eólico en la Bahía de Chetumal es caracterizado, por primera vez, con mediciones in situ de velocidad y dirección del viento usando instrumentación y metodología estándar. Los datos de velocidad y dirección del viento cubren el periodo de 2006 -2010 y fueron obtenidos con una estación meteorológica NRG con dos anemómetros, una paleta de dirección de viento y un sensor de temperatura. Como resultado se estimó una velocidad promedio de 6.5 m/s a una altura de 50 m, la cual es congruente con el valor obtenido en el Atlas Nacional de Zonas con Alto Potencial de Energías Limpias de la Secretaría de Energía. Con esto, el sitio se considera de bajo viento o clase III de acuerdo con The International Electrotechnical Commission (IEC). Como sugerencia se presenta como propuesta el aerogenerador onshore Siemens Gamesa modelo SG 2.1-114 optimizado para su uso en vientos de bajas velocidades y poca turbulencia. Palabras Clave: Energía eólica, onshore, vientos bajos. Abstract The wind potential in Chetumal Bay (18°31'25.3"N 88°16'07.1"W) it's characterized, for the first time, with speed and direction in situ measurements using instrumentation and standard methodology. Wind speed and direction data includes the period of 2006 -2010 and these were measured with a weather station NRG with anemometers at 14 and 19.5 m high, a wind vane and a temperature sensor at 20 m and 6 m high respectively. As a result, a wind speed of 6.5 m / s at 50 m high was estimated, this is congruent with the value in the Atlas Nacional de Zonas con Alto Potencial de Energías Limpias published by the Secretary of Energy. With the above, the side is considered low wind or class III according to the International Electrotechnical Commission (IEC). The Siemens Gamesa model SG 2.1-114 onshore wind turbine optimized for use in low wind speeds and little turbulence is suggested.. Keywords: Low wind, onshore, power wind

Stability Studies of Nano-Scaled Emulsions Containing Ibuprofen for Topical Delivery

Biphasic systems, like emulsions and nano-scaled emulsions, are naturally unstable. The extent and rate of the destabilization process differ from system to another. The stability of such systems upon storage is an important aspect to ensure their abilities to exert the expected effects and consequently render them pharmaceutically acceptable. In the present study, the stability of the nano-scaled emulsion containing newly synthesized palm oil esters (POEs) was assessed under different storage conditions and over specified durations. Three nano-scaled emulsion formulae were chosen for this investigation. They basically comprised ibuprofen as the active ingredient, triethanolamine aqueous solution pH 7.4 as the external phase, POEs as the oil phase, Tween 80 as an emulsifier, Carbopol® 940 as the rheology modifier and menthol or limonene as penetration promoters. The evaluation processes were carried out at several temperatures (4, 25 and 40 °C) with factors, such as droplets size, electrical conductivity, drug content, pH and flow properties were relatively held constant. The data collectively showed that all formulations were stable over an observation period of three months.Keywords: Ibuprofen, nano-scaled emulsion, palm oil esters, stabilit

Study of Pseudoternary Phase Diagram Behaviour and the Effect of Several Tweens and Spans on Palm Oil Esters Characteristics

Palm oil esters are high molecular weight esters oil that has been newly synthesized by University Putra Malaysia researchers. It has received a lot of attention for its pharmaceutical and chemical application. The aim of this study is to study the effects of the palm oil esters with different HLB surfactant mixture on the ternary diagrams behaviour and to confine the various systems resulted from these combinations. These systems include traditional emulsion, gel area, transpernat micro-emulsion area, O/W and W/O emulsions. In this study, pseudoternary phase diagrams of water, POEs and non-ionic surfactant mixture of several HLB values were constructed using water titration method. The resultant mixtures collected after each addition and mixing of water were analysed visually, along with conductivity, dilution in water and dye test (methylene blue) to classify them as O/W emulsion (transparent and opaque) or W/O (opaque) and liquid or gel. As a conclusion, palm oil esters were found to be suitable for the formulation of different types of emulsion. Additionally, different HLB value of non-ionic surfactant(s) exhibited different pseudoternary phase diagram characteristics.Keywords: palm oil esters, Tween, Span, Pseudoternary phase diagram, O/W emulsio