476 research outputs found
Assessment of the effect of salinity on the early growth stage of the common sunflower (Sanay cultivar) using spectral discrimination techniques
Salinity is one of the main limiting factors for agricultural production. This is especially true in arid and semi-arid regions of the world like Turkey. The objective of this study was to determine if the effect ofsalt concentration on the physiological and physiological features of the sunflower (Helianthus annuus L) could be measured using remote sensing techniques. Sunflower seedlings were grown undercontrolled conditions and irrigated with ½ Hoagland Solution containing three different concentrations of NaCl (salt) (0.0, 0.5, 1.0 and 1.5%). The results showed that plant growth decreased proportionallywith increasing levels of NaCl. Chlorophyll concentration and a Normalized Difference Vegetation Index (NDVI) were derived for the plants using a spectroradiometer. There was found to be a significant (r2 = 0.76) correlation between chlorophyll and NDVI values. Therefore, factors that can be derived through remote sensing such as NDVI and chlorophyll can be used to indirectly demonstrate the impact salinity has on sunflower plants. Therefore, agriculturalists can assess growth rate changes caused by salinity using remote sensing techniques
What to expect from the hydrodynamic energy saving devices
Many retrofitting technologies have been proposed to improve the hydrodynamic performance of existing fleets with the aim of reducing the fuel consumption and consequently CO2 emission. The magnitudes of savings predicted by manufacturers are very promising however ship owners are often still doubtful whether they can achieve what is claimed in operations. This study evaluates the performance of four energy saving devices (ESDs) at ship scale with the aim of assisting ship owners with the decision of selecting suitable devices for their ships. Due to the uncertainties associated with extrapolation of viscous flows from model to full scale it is proposed that investigations must be carried out at full scale; hence a full-scale com putational model was adopted as the only feasible method at the design stage. Two vessels representing di fferent types of ship were selected: a gas carrier and a container ship. Various retrofitting technologies to reduce resistance or to improve the propulsive efficiency were considered. The latter group is subdivided into devices located before, at and aft of the propeller. The resistance induced by large openings on the hull, such as a bow thruster tunnel was quantified and several devices designed to streamline the flow in this region were evaluated. Pre-swirl fins technology was the ESD investigated from preswirl devices. The existing propeller of the gas carrier was replaced with a new type profile propeller which improved the propulsive efficiency. Twisted rudder was the technology investigated from post-swirl ESDs. The level of savings obtained from these technologies was generally less than the values published in the literature. It was concluded that this discrepancy arose for one of three reasons: either the metric used to evaluate the savings was inappropriate, or that the method used to quantify the measure was in accurate, or finally, because the designs examined in the case studies were not suitable optimised. However if some of these devices did not deliver the expected savings because the designs considered in this study were not sufficiently optimised, then the question arises as to whether these devices must be optimised for a specific operational conditions and how well these ESDs behave when the vessel is not operating in the design conditions
Generalized ⊕-supplemented modules
Let R be a ring and M be a left R-module. M is called generalized ⊕- supplemented if every submodule of M has a generalized supplement that is a direct summand of M. In this paper we give various properties of such modules. We show that any finite direct sum of generalized ⊕-supplemented modules is generalized ⊕-supplemented. If M is a generalized ⊕-supplemented module with (D3), then every direct summand of M is generalized ⊕-supplemented. We also give some properties of generalized cover
Dual-Band Transmitter and Receiver with Bowtie-Antenna in 0.13 μm SiGe BiCMOS for Gas Spectroscopy at 222 - 270 GHz
This paper presents a transmitter (TX) and a receiver (RX) with bowtie-antenna and silicon lens for gas spectroscopy at 222-270 GHz, which are fabricated in IHP’s 0.13 μm SiGe BiCMOS technology. The TX and RX use two integrated local oscillators for 222 – 256 GHz and 250 – 270 GHz, which are switched for dual-band operation. Due to its directivity of about 27 dBi, the single integrated bowtie-antenna with silicon lens enables an EIRP of about 25 dBm for the TX, and therefore a considerably higher EIRP for the 2-band TX compared to previously reported systems. The double sideband noise temperature of the RX is 20,000 K (18.5 dB noise figure) as measured by the Y-factor method. Absorption spectroscopy of gaseous methanol is used as a measure for the performance of the gas spectroscopy system with TX- and RX-modules
Gene-based partial least-squares approaches for detecting rare variant associations with complex traits
Genome-wide association studies are largely based on single-nucleotide polymorphisms and rest on the common disease/common variants (single-nucleotide polymorphisms) hypothesis. However, it has been argued in the last few years and is well accepted now that rare variants are valuable for studying common diseases. Although current genome-wide association studies have successfully discovered many genetic variants that are associated with common diseases, detecting associated rare variants remains a great challenge. Here, we propose two partial least-squares approaches to aggregate the signals of many single-nucleotide polymorphisms (SNPs) within a gene to reveal possible genetic effects related to rare variants. The availability of the 1000 Genomes Project offers us the opportunity to evaluate the effectiveness of these two gene-based approaches. Compared to results from a SNP-based analysis, the proposed methods were able to identify some (rare) SNPs that were missed by the SNP-based analysis
BRCA1 and BRCA2 mutations in Turkish breast/ovarian families and young breast cancer patients
To date, BRCA1 and BRCA2 mutations in breast and/or ovarian patients have not been characterized in the Turkish population. We investigated the presence of BRCA mutations in 53 individuals with a personal and family history of breast and/or ovarian cancer, and 52 individuals with a personal history of breast cancer diagnosed below age 50 without additional family history. We have identified 11 mutations (nine BRCA1 and two BRCA2) using combined techniques involving protein truncation test, direct sequencing and heteroduplex analysis. We found eight out of 53 patients (15.1%) with a family history to carry BRCA gene mutations (seven BRCA1 and one BRCA2). Of these, four were found in 43 families presenting only breast cancer histories, and four were found in families presenting ovarian cancer with or without breast cancer. We also demonstrated two BRCA1 and one BRCA2 mutations in three out of 52 (5.8%) early-onset breast cancer cases without additional family history. Three of nine BRCA1 and both BRCA2 mutations detected in this study were not reported previously. These mutations may be specific to the Turkish population. The BRCA1 5382insC mutation, specific to Ashkenazi and Russian populations, was found twice in our study group, representing a possible founder mutation in the Turkish population. © 2000 Cancer Research Campaig
Assessing flow response of self-compacting mortar by Taguchi method and ANOVA interaction
Seroprevalence and risk factors for toxoplasma infection among pregnant women in Aydin province, Turkey
BACKGROUND: The aims of the present study were to determine the prevalence of toxoplasmosis in pregnant women at first trimester of their pregnancy and to follow up the seroconversion for next two trimesters, and to identify the risk factors and possible contamination routes in Aydin province, Turkey. METHOD: The sample size was calculated as 423 on a prevalence of 50%, d=0.05 at a confidence level of 95% with 10% addition. It was a cross-sectional study with multistage sampling. After a questionnaire applied to the pregnant women, anti-Toxoplasma IgG antibodies were studied with ELISA and IFA, values in conflict with DA test, where IgM antibodies were studied with ELISA and for borderline or positive values of IgM avidity test was used. RESULTS: The mean age of 389 (92.9%) of pregnant women in the study was 24.28+/-4.56 years, the seroprevalence of anti-Toxoplasma IgG antibodies for toxoplasmosis was 30.1%. Seroprevalence was increased with age (p=0.001) and with drinking water consumption other than bottled water (p=0.042). No significant relations were observed between anti-Toxoplasma IgG antibodies and education level, being native or migrant, abortion history, consumption of meat, vegetable and milk/milk products, personal or kitchen hygiene habits, cat owning at home of the pregnant women. No IgM antibody was detected. CONCLUSION: One of every three pregnant women in Aydin was at risk of toxoplasmosis at the first trimester of their pregnancy. Increased seroprevalance with age was a predictable result because of increasing time of exposure. Increased seroprevalence with consumption of municipal and uncontrolled water (well/spring water) supplies was similar with latest epidemiological findings
Integration of Hi-C with short and long-read genome sequencing reveals the structure of germline rearranged genomes
Here the authors characterize structural variations (SVs) in a cohort of individuals with complex genomic rearrangements, identifying breakpoints by employing short- and long-read genome sequencing and investigate their impact on gene expression and the three-dimensional chromatin architecture. They find breakpoints are enriched in inactive regions and can result in chromatin domain fusions.Structural variants are a common cause of disease and contribute to a large extent to inter-individual variability, but their detection and interpretation remain a challenge. Here, we investigate 11 individuals with complex genomic rearrangements including germline chromothripsis by combining short- and long-read genome sequencing (GS) with Hi-C. Large-scale genomic rearrangements are identified in Hi-C interaction maps, allowing for an independent assessment of breakpoint calls derived from the GS methods, resulting in >300 genomic junctions. Based on a comprehensive breakpoint detection and Hi-C, we achieve a reconstruction of whole rearranged chromosomes. Integrating information on the three-dimensional organization of chromatin, we observe that breakpoints occur more frequently than expected in lamina-associated domains (LADs) and that a majority reshuffle topologically associating domains (TADs). By applying phased RNA-seq, we observe an enrichment of genes showing allelic imbalanced expression (AIG) within 100 kb around the breakpoints. Interestingly, the AIGs hit by a breakpoint (19/22) display both up- and downregulation, thereby suggesting different mechanisms at play, such as gene disruption and rearrangements of regulatory information. However, the majority of interpretable genes located 200 kb around a breakpoint do not show significant expression changes. Thus, there is an overall robustness in the genome towards large-scale chromosome rearrangements
Team creativity/innovation in culturally diverse teams: A meta‐analysis
This meta-analysis investigates the direction and strength of the relationship between diversity in culturally diverse teams and team creativity/innovation. We distinguish the effects of two diversity levels (i.e., surface- versus deep-level) in culturally diverse teams and examine the moderators suggested by the socio-technical systems framework (i.e., team virtuality and task characteristics in terms of task interdependence, complexity, and intellectiveness). Surface-level diversity in culturally diverse teams is not related to team creativity/innovation, while deep-level diversity in culturally diverse teams is positively related to team creativity/innovation. Moreover, surface-level diversity in culturally diverse teams and team creativity/innovation are negatively related for simple tasks, but unrelated for complex tasks. Deep-level diversity in culturally diverse teams and team creativity/innovation are positively related for collocated teams and interdependent tasks, but unrelated for non-collocated teams and independent tasks. We discuss the theoretical and practical implications
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