327 research outputs found
Effect of four powdered spices as repellents against adults of Rhyzopertha dominica (F.), Sitophilus granarius (L.) and Tribolium castaneum (Herbst) in laboratory conditions
Studies were conducted to test the repellency of four powdered spices, black pepper (Piper nigrum.), chili pepper (Capsicum annuum), cinnamon (Cinnamomum aromaticum) and turmeric (Curcuma longa), against three stored-product insects, the lesser grain borer, Rhyzopertha dominica, the granary weevil, Sitophilus granarius and the red flour beetle, Tribolium castaneum. The cup bioassay technique was used, to determine the response of insects to potential repellents by measuring their movement from treated grain. The device is made of galvanized screening with 2 mm perforations shaped into a cylinder of 6 cm diameter and 15 cm high, with a mesh bottom, and is placed in the centre portion of plastic container of 15 cm diameter and 15 cm high. The powdered spices were poured into 200 g of wheat mass by a long-stemmed funnel at concentrations of 0, 0.25, 0.75, 1.5 and 2.5% on (w/w) basis. Twenty adults of three species are released into the centre of the grain mass in the container through a long-stemmed funnel. The experiments were conducted at room conditions. The number of trapped insects was determined at 3 different intervals after the introduction of the insects. Results showed that all tested plant powders had repellent activity against the three stored-product insects. Adults of S. granarius repelled faster, followed by T. castaneum and R. dominica. At the highest concentrations and intervals, wheat grains treated with cinnamon powder were the most repellent to adults of S. granarius (up to 92.5% after 1 h), followed by chili pepper treatment for T. castaneum (up to 72.5% after 6 h) and black pepper treatment for R. dominica(up to 58.75% after 24 h).Keywords: Repellency, Spices, Rhyzopertha dominica, Sitophilus granarius, Tribolium castaneu
Curriculum innovations through advancement of MEMS/NEMS and wearable devices technologies
State of the art technologies using both micro- and nano-electromechanical systems (MEMS and NEMS) and wearable and Internet of Things (IoT) devices have impacted our daily lives in applications including wearable devices and sensor technology as applied to renewable energies and health sciences, among others. Several examples are device implants, optical devices, micro and nanomachining, embedded systems and integrated nano sensor systems. The recent Electrical and Computer Engineering (ECE) and Mechanical Engineering (ME) curricula lacked inclusion of these elements within their programs. Close scrutiny to the need of local industry from engineering graduates has emphasized the motivation to develop these materials into the engineering curricula. Within the ECE curriculum, a new senior course was developed to cover MEMS/NEMS devices as well as wearable and IoT devices with Bluetooth and wireless features. The MEMS/NEMS module of the new course integrates software CAD tools and hardware implementations. It is a project-based course where students learn software for the device process, then fabricate the device in the school laboratories. The wearable and IoT devices module introduces the students to Wearable and Internet of Things systems. It covers sensors and sensor fusion, embedded processors, tools for wearable and IoT applications, and design using Bluetooth and wireless IoT systems. The new course development objectives are hands-on practice, and preparation of senior students for industrial and research careers. In addition, an introductory MEMS topic section is added in the sophomore level electrical engineering course offered to mechanical engineering students. It introduces MEMS devices employed as energy conversion devices. Based on our recent feedback, the students have favorably accepted this MEMS addition to the course. This paper details the software and hardware development elements of the new course. It also presents the assessment data for students' satisfaction for both the electrical and computer engineering (ECE), and mechanical engineering (ME) students. © American Society for Engineering Education, 2017
The heritability of premenstrual syndrome
We aimed to determine (1) the prevalence of premenstrual syndrome in a sample of twins and (2) the relative contribution of genes and environment in premenstrual syndrome. A group of 193 subjects inclusive of same gender twins (n = 176) and females from opposite sex twin sets (n = 17) entered the study. Heritability analysis used same gender twin data only. The probandwise concordance rate for the presence or absence of premenstrual syndrome was calculated and the heritability of premenstrual syndrome was assessed by a quantitative genetic model fitting approach using MX software. The prevalence of premenstrual syndrome was 43.0% and 46.8% in monozygotic and dizygotic twins, respectively. The probandwise concordance for premenstrual syndrome was higher in monozygotic (0.81) than in dizygotic twins (0.67), indicating a strong genetic effect. Quantitative genetic modeling found that a model comprising of additive genetic (A) and unique environment (E) factors provided the best fit (A: 95%, E: 5%). No association was found between premenstrual symptom and the following variables: belonging to the opposite gender twin set, birth weight, being breast fed and vaccination. These results established a clear genetic influence in premenstrual syndrome
Environmental and strategic assessment of ecotourism potential in Anzali Wetland using SWOT analysis
SWOT analysis is used extensively as an assessment and planning method, particularly in tourism planning. However, there are little documentations on application of SWOT analysis in ecotourism. An assessment on systematic use of SWOT analysis was carried out in the present study to highlight the applicability of the SWOT technique in detailed investigations. In this study, based on field surveys and questionnaires (on Anzali Wetland and the local population), matrix of internal and external factors (threats, opportunities, weaknesses and strength) influencing tourism development in Anzali Wetland were evaluated within the framework of SWOT analysis and SO, WO, ST and WT strategies were identified. Based on the obtained results, the total score of 3.22 in IFE matrix suggests good condition of the system and high internal strength of the tourism development related to internal factors and the final score of 2.93 in the EFE matrix represents poor condition related to the external factors which means external factors have not been utilized properly; Thus appropriate planning and organizational management practices are required to deal with these factors. The study further proposes solutions, operational priorities and strategic planning according to environmental and local conditions of Anzali Wetland. Since the tourism industry in Iran is still in its early stages, particularly in Anzali Wetland region, the findings could help decision makers to estimate better the weaknesses, strengths, threats and opportunities, and to develop tourism industry in the region
Magnetic properties of the spin Heisenberg chain with hexamer modulation of exchange
We consider the spin-1/2 Heisenberg chain with alternating spin exchange %on
even and odd sites in the presence of additional modulation of exchange on odd
bonds with period three. We study the ground state magnetic phase diagram of
this hexamer spin chain in the limit of very strong antiferromagnetic (AF)
exchange on odd bonds using the numerical Lanczos method and bosonization
approach. In the limit of strong magnetic field commensurate with the
dominating AF exchange, the model is mapped onto an effective Heisenberg
chain in the presence of uniform and spatially modulated fields, which is
studied using the standard continuum-limit bosonization approach. In absence of
additional hexamer modulation, the model undergoes a quantum phase transition
from a gapped string order into the only one gapless L\"uttinger liquid (LL)
phase by increasing the magnetic field. In the presence of hexamer modulation,
two new gapped phases are identified in the ground state at magnetization equal
to 1/3 and 2/3 of the saturation value. These phases reveal themselves also in
magnetization curve as plateaus at corresponding values of magnetization. As
the result, the magnetic phase diagram of the hexamer chain shows seven
different quantum phases, four gapped and three gapless and the system is
characterized by six critical fields which mark quantum phase transitions
between the ordered gapped and the LL gapless phases.Comment: 21 pages, 5 figures, Journal of Physics: Condensed Matter, 24,
116002, (2012
Energy use and height in office buildings
The relationship between energy use and height is examined for a sample of 611 office buildings in England and Wales using actual annual metered consumption of electricity and fossil fuels. The buildings are of different ages; they have different construction characteristics and methods of heating and ventilation; and they include both public and commercial offices. When rising from five storeys and below to 21 storeys and above, the mean intensity of electricity and fossil fuel use increases by 137% and 42% respectively, and mean carbon emissions are more than doubled. A multivariate regression model is used to interpret the contributions of building characteristics and other factors to this result. Air-conditioning is important, but a trend of increased energy use with height is also found in naturally ventilated buildings. Newer buildings are not in general more efficient: the intensity of electricity use is greater in offices built in recent decades, without a compensating decrease in fossil fuel use. The evidence suggests it is likely – although not proven – that much of the increase in energy use with height is due to the greater exposure of taller buildings to lower temperatures, stronger winds and more solar gains
All the way to the top! The energy implications of building tall cities
Density of urban form may be achieved under a variety of morphological designs that do not rely on tallness alone. Tall buildings have implications on the broader urban environment and infrastructure that lower buildings would not have, e.g. wind effects, sight-lines, or over-shading. They may also have an impact on energy use for reasons of buildings-physics, construction, and occupant practices. This study uses a statistical approach of neighbourhood level data to analyse the impact of building morphology (e.g. height, volume and density) on energy demand in 12 local authorities in London. The research shows that areas marked by tall buildings use more gas after adjusting for exposures surface area, volume, number of residents and other features. The implication for energy policy and planning is building taller without increasing density may have an energy penalty
1-Methyl tryptophan, an indoleamine 2,3-dioxygenase inhibitor, attenuates cardiac and hepatic dysfunction in rats with biliary cirrhosis
Kynurenine Pathway (KP) is the dominant metabolic route of tryptophan which is catalyzed by indoleamine-2,3-dioxygenase (IDO). This pathway is upregulated in liver disease where the level of KP metabolites correlates with the severity of disease. Cirrhosis is associated with cardiac dysfunction, which manifests itself during severe physiological challenges such as liver transplantation. Cardiac dysfunction in cirrhosis is linked to systemic inflammation and impaired cardiac beta-adrenergic signaling pathways. The KP pathway is involved in modulation of cardiac signaling and is upregulated by systemic inflammation. Therefore, this study aimed to evaluate the effect of IDO inhibition on development of cardiac dysfunction in an experimental model of cirrhosis. Cirrhosis was induced by bile duct ligation (BDL). Experimental groups were given either 1-methyl tryptophan (1-MT, 1, 3, 9 mg/kg), or saline. 28 days after BDL, cardiac chronotropic response to epinephrine was assessed ex vivo. HPLC was employed to measure hepatic and cardiac levels of tryptophan, kynurenine and kynurenic acid. Cirrhosis in rats was associated with impaired cardiac chronotropic responsiveness to adrenergic stimulation. 1-MT dose-dependently improved cirrhosis-induced chronotropic dysfunction as well as elevated serum levels of CRP and IL-6 in BDL rats. Hepatic and cardiac kynurenine/tryptophan ratio were elevated in cirrhotic rats and were reduced following 1-MT administration. Chronic administration of 1-MT could also reduce hepatic inflammation, fibrosis and ductular proliferation. 1-MT attenuates cardiac dysfunction in rats with biliary cirrhosis. This protective effect is not limited to the cardiac function as liver histopathologic changes were also improved following chronic 1-MT administration
Molecular characterization of Iranian patients with possible familial hypercholesterolemia.
Familial hypercholesterolemia (FH) is an autosomal dominant disorder of lipoprotein metabolism caused mainly by mutations in the low-density lipoprotein receptor (LDLR) and apolipoprotein B 100 (APOB) genes. Until now, the molecular basis of FH has been demonstrated in detail in many populations, but there is still very limited Molecular data concerning FH in Iran. The aim of this study was to characterize the LDLR and APOB gene mutations in an Iranian population. A total of 30 non-related Iranian possible FH subjects were studied. Diagnosis of FH was based on the Dutch Lipid Clinic Network diagnostic criteria. All samples were initially tested for three common APOB gene mutations including R3500Q, R3500 W and R3531C using PCR-RFLP assay. Subsequently, promoter and coding region of the LDLR gene was screened by PCR-SSCP analysis and positive results were confirmed by DNA sequencing. Four previously reported polymorphisms 1413G > A, 1725C > T, 1773T > C and 2140 + 5G > A were found in ~17% (5/30) of population studied. Moreover, no variation was found in APOB gene. Our data indicated that LDLR and APOB gene mutations have not contribution to possible FH in Iranian population studied here. However, we examined three common APOB mutations and LDLR in only 30 patients, and to determine the role of these genes in developing FH in Iran, more FH samples and populations needed to be investigated for the mutations of the related genes
- …