498 research outputs found
Drought and oxidative stress
Drought, a natural stress factor has the highest percentage with 26%, when the usable areas on the earth are classified in view of stress factors. Biotic and abiotic stress factors may cause yield loss in plants and affect human and animal nutrition. Amount of lacking yield due to biotic and abiotic stress factors ranged between 65 and 87%. The best option for crop production, yield improvement and yield stability under soil moisture deficient conditions is to develop drought tolerant crop varieties (Siddique et al., 2000). A physiological approach would be the most attractive way to develop new varieties rapidly. Only few studies highlighted the importance of antioxidant enzymes during drought stress. The antioxidant defenses appear to provide crucial protection against oxidative damage in cellular membranes and organelles in plants grown under unfavorable conditions. Thus, plants are equipped with complex and a highly efficient antioxidative defense system which can respond and adapt to drought stress. This system is composed of protective nonenzymatic and enzymatic protection mechanisms. They interrupt the uncontrolled oxidation and serve to maintain the antioxidants in their reduced functional state, that efficiently scavenge ROS (reactive oxygen species) and prevent damaging effects of free radicals. Balance at aerobic metabolism is defined as free radical generation and rapid removal by antioxidant systems. The structure of cells and functional changes of systems, may be damaged by the formation of irreversible oxidative stress. Redox signalling and antioxidative defense systems are very important for protection towards uncontrolled and cascade damage of biotic and abiotic stress factors. In this review, drought, drought types and antioxidative defense system components will be discussed.Key words: Antioxidative defense system, ascorbate peroxidase, catalase, drought types, glutathione reductase, oxidative stress, superoxide dismutase
CHARACTERIZATION OF CYLINDROCARPON-LIKE ANAMORPHS CAUSING ROOT AND BASAL ROT OF APRICOT AND IN VITRO ACTIVITIES OF SOME FUNGICIDES
Four apricot nurseries were surveyed in Hatay province in Turkey to evaluate the phytosanitary status of the nursery plant material. Endophytic and potential pathogenic fungi were identified in plants and 12 Cylindrocarpon-like anamorph isolates were detected in the root system and basal stems of analyzed rootstocks. Based on partial sequencing ITS, three different Cylindrocarpon-like anamorph species were identified as Dactylonectria torresensis (6 isolates), Dactylonectria novozelandica (3 isolates) and Neonectria candida (3 isolates). Pathogenicity tests were conducted under greenhouse conditions which showed that all three Cylindrocarpon-like anamorph species, were identified as pathogens. ADt12 (D. torresensis) isolate, obtained from the survey area, have been tested in vitro for its sensitivity to several fungicides (thiophanate-methyl (70%), fluazinam (500g/L), fludioxonil (230g/L), and boscalid (26.7%)+pyraclostrobin (6.7%)). It was determined that ADt12 isolate was highly sensitive to fludioxonil and fluazinam, and sensitive to thiophanate-methyl and boscalid+pyraclostrobin as a result of probit analysis of EC50 values
Higher Twist Effects in Photon-Photon Collisions
In this article, we investigate the contribution of the high twist Feynman
diagrams to the large single pseudoscalar and vector mesons inclusive
production cross section in two-photon collisions and we present the general
formulae for the high and leading twist differential cross sections. The pion
wave function where two non-trivial Gegenbauer coefficients and
have been extracted from the CLEO data, Braun-Filyanov pion wave function, the
asymptotic and the Chernyak-Zhitnitsky wave functions are used in the
calculations. For -meson we used Ball-Braun wave function. The results of
all the calculations reveal that the high twist cross sections, the ratio R,
the dependence transverse momentum and the rapidity of meson in
wave function case is very close to the
asymptotic wave function case. It is shown that the high twist contribution to
the cross section depends on the choice of the meson wave functions.Comment: REVTEX4, 23 pages, 7 figure
Investigation of the nuetralino pair production at LHC
In this article, we investigate the Drell-Yan process of the light neutralino
pair () productions
at proton-proton collisions and we present the general formulate for the
differential cross sections. We conduct an extensive examination of the
dependence of the total cross section of the subprocesses on the beam energy, on the mass
of the squarks and also on the gaugino for the three extremely different
scenarios. For all three cases, the outcomes are as follows. The dependence of
the total cross section of the subprocesses on the beam energy is dominated by one of
the subprocesses, . On the other hand, the dependence of the total cross section of
the subprocesses
on the mass of the squarks is dominated by one of the subprocesses, . We derive there from that
our findings may lead to new insights relating to experimental investigations
and these dependencies may be used as bases of an experimental research for the
neutralino pair at LHC.Comment: 38pp, 22 figures, ReVTeX4, (Baku State University, Azerbaijan, and
Erciyes University, Kayseri, Turkey
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Query Extension Suggestions for Visual Query Systems Through Ontology Projection and Indexing
Ontology-based visual query formulation is a viable alternative to textual query editors in the Semantic Web domain for extracting data from structured data sources in terms of the skills and knowledge required. A visual query system is at any moment responsible for providing the user with query extension suggestions; however, suggestions leading to empty results are often not useful. To this end, in this article, we first present an approach for projecting OWL 2 ontologies into navigation graphs to be used for query formulation and then a solution where an efficient finite index is used to calculate non-ranked approximated extension suggestions for ontology-based visual query systems using navigation graphs. The results of our experiments suggest that one can efficiently project an ontology into a navigation graph, query it for running an interactive user interface, and suggest query extensions that do not lead to dead-ends
Higher Twist Effects in Proton-Proton Collisions
In this article, we investigate the contribution of the high twist Feynman
diagrams to the large- pion production cross section in proton-proton
collisions and we present the general formulae for the high and leading twist
differential cross sections. The pion wave function where two non-trivial
Gegenbauer coefficients and have been extracted from the CLEO data,
two other pion model wave functions, , , the asymptotic and the
Chernyak-Zhitnitsky wave functions are used in the calculations. The results of
all the calculations reveal that the high twist cross sections, the ratios ,
, the dependence transverse momentum and the rapidity of pion in
the wave function case is very close to the
asymptotic wave function case. It is shown that the high twist
contribution to the cross section depends on the choice of the meson wave
functions.Comment: 28 pages 18 figures RevTex
The (Biological or Cultural) Essence of Essentialism: Implications for Policy Support among Dominant and Subordinated Groups
Most research links (racial) essentialism to negative intergroup outcomes. We propose that this conclusion reflects both a narrow conceptual focus on biological/genetic essence and a narrow research focus from the perspective of racially dominant groups. We distinguished between beliefs in biological and cultural essences, and we investigated the implications of this distinction for support of social justice policies (e.g., affirmative action) among people with dominant (White) and subordinated (e.g., Black, Latino) racial identities in the United States. Whereas, endorsement of biological essentialism may have similarly negative implications for social justice policies across racial categories, we investigated the hypothesis that endorsement of cultural essentialism would have different implications across racial categories. In Studies 1a and 1b, we assessed the properties of a cultural essentialism measure we developed using two samples with different racial/ethnic compositions. In Study 2, we collected data from 170 participants using an online questionnaire to test the implications of essentialist beliefs for policy support. Consistent with previous research, we found that belief in biological essentialism was negatively related to policy support for participants from both dominant and subordinated categories. In contrast, the relationship between cultural essentialism and policy support varied across identity categories in the hypothesized way: negative for participants from the dominant category but positive for participants from subordinated categories. Results suggest that cultural essentialism may provide a way of identification that subordinated communities use to mobilize support for social justice
Impact of the Covid-19 pandemic on education: experiences and feelings reported by primary school pupils from Greece and Turkey
Covid 19 pandemic had a huge impact upon life and the educational experience of students. One of the groups mostly affected from this pandemic is the school children. The sudden transition to distance education from traditional face-to-face education undoubtedly changed the implementation methods of the teaching programme in schools. The research study reported in this paper was carried out in Greece and Turkey. Responses were collected from primary school pupils who voluntarily and anonymously completed an online questionnaire with multiple choice questions. The latter were carefully worded in an appropriate and understandable way, using language suitable for primary school aged children. Comparisons between the responses from the two countries revealed similarities and differences. Through a comparative approach the research results are particularly scruitinised through the lenses of equal opportunities and social exclusion policies along with a cross cultural perspective, which is expected to have a useful impact during the post pandemic era. By sharing the collective knowledge and experience gained, we aspire to propose educational strategies for well-being and recovery, and overall educational process improvement
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Querying industrial stream-temporal data: An ontology-based visual approach
An increasing number of sensors are being deployed in business-critical environments, systems, and equipment; and stream a vast amount of data. The operational efficiency and effectiveness of business processes rely on domain experts’ agility in interpreting data into actionable business information. A domain expert has extensive domain knowledge but not necessarily skills and knowledge on databases and formal query languages. Therefore, centralised approaches are often preferred. These require IT experts to translate the information needs of domain experts into extract-transform-load (ETL) processes in order to extract and integrate data and then let domain experts apply predefined analytics. Since such a workflow is too time intensive, heavy-weight and inflexible given the high volume and velocity of data, domain experts need to extract and analyse the data of interest directly. Ontologies, i.e., semantically rich conceptual domain models, present an intelligible solution by describing the domain of interest on a higher level of abstraction closer to the reality. Moreover, recent ontology-based data access (OBDA) technologies enable end users to formulate their information needs into queries using a set of terms defined in an ontology. Ontological queries could then be translated into SQL or some other database query languages, and executed over the data in its original place and format automatically. To this end, this article reports an ontology-based visual query system (VQS), namely OptiqueVQS, how it is extended for a stream-temporal query language called STARQL, a user experiment with the domain experts at Siemens AG, and STARQL’s query answering performance over a proof of concept implementation for PostgreSQL
Intracortical injection of endothelin-1 induces cortical infarcts in mice: effect of neuronal expression of an adenosine transporter
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