1,820 research outputs found
Evaluation of bacteria for biological control of early blightdisease of tomato
Twenty three bacterial isolate out of 190, exhibiting inhibitory affects against Alternaria solani in preliminary tests, were screened for their activity towards A. solani Ell. and G. Martin) Sor. by a dualculture in vitro assay on nutrient agar (NA) medium and in vivo (whole plant) test. In vitro studies indicated that all the 23 bacterial isolates inhibited the mycelial growth of A. solani by forming inhibition zone ranging from 9.35 to 31.3 mm. The most effective isolate was Serratia plymuthica (IK- 139) (31.3 mm) based on the in vitro test results. Twenty three bacterial isolates were subjected to a whole plant test to investigate their ability to protect the tomato plant against early blight disease. In whole plant tests, 0.5 x 108 cfu/ml bacterial suspension was sprayed and one day later, A. solani spores suspension were applied on tomato seedlings and plants were incubated in moist chamber at 20°C with 95% relative humidity (RH) and 12 h photoperiods for 21 days. Based on the whole plant tests, Paenibacillus macerans-GC subgroup A (1.82), Serratia plymuthica (1.78), Bacillus coagulans (1.75), Serratia marcescens-GC subgroup A (1.50), Bacillus pumilis –GC subgroup B (1.50) and Pantoea agglomerans (1.32) bacterial isolates reduced the disease severity of early blight significantly when compared with control. These results suggest that the bacterial isolates studied have a good potential to be used as biocontrol agents of A. solani in tomato.Key words: Alternaria solani, early blight, biological control, bacterial isolate
Synthesis of Multi-substituted 4,5-Dihydrofuran Derivatives from (S)-Limonene and 1,3-Dicarbonyl Compounds and their Biological Activities
Multi-substituted 4,5-dihydrofuran derivatives were regioselectively synthesized by the reaction of α-carbo radical produced from 1,3-dicarbonyl compounds by oxidation with Mn(OAc)3 in Acetic acid and S-(-)-limonene. All the compounds were tested for their antibacterial and antifungal activities by the disc-diffusion technique
Sampling-based Algorithms for Optimal Motion Planning
During the last decade, sampling-based path planning algorithms, such as
Probabilistic RoadMaps (PRM) and Rapidly-exploring Random Trees (RRT), have
been shown to work well in practice and possess theoretical guarantees such as
probabilistic completeness. However, little effort has been devoted to the
formal analysis of the quality of the solution returned by such algorithms,
e.g., as a function of the number of samples. The purpose of this paper is to
fill this gap, by rigorously analyzing the asymptotic behavior of the cost of
the solution returned by stochastic sampling-based algorithms as the number of
samples increases. A number of negative results are provided, characterizing
existing algorithms, e.g., showing that, under mild technical conditions, the
cost of the solution returned by broadly used sampling-based algorithms
converges almost surely to a non-optimal value. The main contribution of the
paper is the introduction of new algorithms, namely, PRM* and RRT*, which are
provably asymptotically optimal, i.e., such that the cost of the returned
solution converges almost surely to the optimum. Moreover, it is shown that the
computational complexity of the new algorithms is within a constant factor of
that of their probabilistically complete (but not asymptotically optimal)
counterparts. The analysis in this paper hinges on novel connections between
stochastic sampling-based path planning algorithms and the theory of random
geometric graphs.Comment: 76 pages, 26 figures, to appear in International Journal of Robotics
Researc
Suitability of foramen magnum measurements in sex determination and their clinical significance
Background: The foramen magnum provides a transition between fossa cranii posterior and canalis vertebralis. Medulla oblongata, arteria vertebralis and nervus accessorius spinal part pass through the foramen magnum. In this study, we aimed to make the morphometric measurements of the foramen magnum on computed tomography (CT) and to determine the feasibility of sex determination based on these measurements. Besides sex determination, from a clinical aspect, it is important to know the measurements of the foramen magnum in the normal population in terms of diseases characterised by displacement of the posterior fossa structures through foramen magnum to upper cervical spinal canal such as Chiari malformations and syringomyelia.
Materials and methods: All the data for our study was obtained retrospectively from 100 patients (50 males, 50 females) who had a CT scan of the head and neck region in Adnan Menderes University Hospital, Department of Radiology. To examine the foramen magnum in each and every occipital bone, we measured the foramen magnum’s anteroposterior diameter, transverse diameter, the area of the foramen magnum and its circumference.
Results: We found that men have a higher average value than women in our study. According to Student’s t-test results; in all measured parameters, there is significant difference between the genders (p < 0.05). When multivariate discriminant function test is performed for all four measurements, the discrimination rate is 64% for all women, 70% for all men and 67% for both genders.
Conclusions: As a result of our study, the metric data we obtained will be useful in cases where the skeletons’ sex could not be determined by any other methods. We believe that, our study may be useful for other studies in determining of sex from foramen magnum. Our measurements could give some information of the normal ranges of the foramen magnum in normal population, so that this can contribute to the diagnosis process of some diseases by imaging. (Folia Morphol 2018; 77, 1: 99–104)
Anisotropic photoconductivity in graphene
We investigate the photoconductivity of graphene within the relaxation time
approximation. In presence of the inter-band transitions induced by the
linearly polarized light the photoconductivity turns out to be highly
anisotropic due to the pseudospin selection rule for Dirac-like carriers. The
effect can be observed in clean undoped graphene samples and be utilized for
light polarization detection.Comment: 4 pages, 2 figure
Clip-level feature aggregation : a key factor for video-based person re-identification
In the task of video-based person re-identification, features
of persons in the query and gallery sets are compared to search the
best match. Generally, most existing methods aggregate the frame-level
features together using a temporal method to generate the clip-level fea-
tures, instead of the sequence-level representations. In this paper, we
propose a new method that aggregates the clip-level features to obtain
the sequence-level representations of persons, which consists of two parts,
i.e., Average Aggregation Strategy (AAS) and Raw Feature Utilization
(RFU). AAS makes use of all frames in a video sequence to generate
a better representation of a person, while RFU investigates how batch
normalization operation influences feature representations in person re-
identification. The experimental results demonstrate that our method
can boost the performance of existing models for better accuracy. In
particular, we achieve 87.7% rank-1 and 82.3% mAP on MARS dataset
without any post-processing procedure, which outperforms the existing
state-of-the-art
Legal basis and main technologies of socio-psychological work with vulnerable categories of the population in the community
The war in Ukraine has led to an increase in the need for social assistance among vulnerable populations, which requires strengthening the capacity of social services to respond to new challenges. The purpose of this study is to examine the legal and technological framework for wartime assistance and to demonstrate the effectiveness of modern methods through theoretical and empirical analysis. Data collection and analysis were conducted in compliance with ethical and legal standards for social research. Currently, Ukrainian policy makes it possible to support models such as the proposed Integrated Social Services approach. However, the findings of the study indicate a potential need for legal/regulatory reforms to further strengthen the capacity to respond to crisis situations. The results confirm that the implemented interventions successfully address the problems of displaced persons, veterans, most-at-risk families, etc. Individual case management and group social and psychological trainings contribute to capacity development, and the model of integrated services allows for quick resolution of acute problems. Comparative evaluations show that the integrated system is superior to individual methods in quickly addressing crisis situations. However, new groups that fall outside the scope of current legislation, such as victims of domestic violence, may require mandatory expansion of eligibility criteria. Laws could also include standards for interagency coordination to address fragmentation. This urgent relevance highlights how robust legal/ethical foundations uphold assistance models in turmoil. It was also concluded that the implementation of legal reforms that would create a unified system of cooperation could mitigate these problems. In particular, legislation could formalise requirements such as data and information sharing between service providers, common case management procedures, common reporting standards and interdisciplinary partnerships. The practical significance of the study lies in the possibility of using the results of the problem analysis to create accessible mechanisms to improve the quality of support for vulnerable demographic groups. Enshrining access to care as an inalienable guarantee creates an ecosystem that is resilient to modern threat
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