Reduction of detection volume in total internal reflection fluorescence microscopy using graphene

We show that it is possible to decrease the thickness of the detection volume of total internal reflection fluorescence microscopy (TIRFM) by ~35% using a graphene layer in the interface between glass and water layers of a typical TIRFM structure without sacrificing the fluorescence intensity. The highly mobile surface bound electrons of a graphene mono-layer quenches the fluorophores that are less than ~40 nm away from it. The decreased detection volume using the proposed structure will increase the resolution of' a typical TIRFM technique. We find that the results are qualitatively similar for different incidence angles and polarizations of' the excitation field. So, the proposed structure will also find applications in variants of TIRFM techniques, e.g., where incidence angles and polarizations are varied

Financing behavior of R&D investments in the emerging markets : the role of alliance and financial system

This paper examines the financing behaviour of R&D investments in emerging markets. Drawing on institutional theory and using panel data of generalized methods of moment (GMM) estimation for a sample of 302 firms from 20 countries during the period 2003-2015, we find that emerging market firms tend to use internal funds for financing R&D investments. Interesting results emerged when the sample was divided as alliance and non-alliance firms, and bank-based and market-based financial systems. The results show that R&D financing behaves differently for alliance and non-alliance firms. Alliance firms use both internal and external funds for R&D investments, while non-alliance firms do not use external funds. We also document that a country’s financial system influences the choice of available sources of finance. Firms from countries that follow a bank-based financial system tend to rely on external funds while firms from countries that follow a market-based financial system depend more on internal funds for financing R&D investments. This study is important as it provides new evidence on financing R&D investments in emerging countries taking into account the institutional arguments of financing choices, and so should guide stakeholders about appropriate sources of R&D financing

Surface plasmon coupled emission enhancement with nanoparticles in the metal layer

We show that it is possible to enhance surface plasmon coupled emission (SPCE) intensity by ∼55% using two dimensional periodic nanoparticle arrays in the glass-metal layer interface of an SPCE structure. The nanoparticles act as coupled nanoantennas. With optimized dimensions and periodicity, the nanoparticle arrays resonate and re-emit intensified SPCE. In this work, two types of nanoparticles such as cuboids and hemispheres are used in the arrays. The optimized dimensions and periodicity of the nanoparticle arrays that lead to enhanced intensity are calculated using the particle swarm algorithm. The increased SPCE intensity will be helpful for using SPCE as a biomolecule detection scheme

Bioefficacy of Plant Extracts to Control Cercospora Leaf Spot of Mungbean (Vigna radiata)

The experiment was conducted at Bangladesh Agricultural Research Institute farm, Joydebpur, Gazipur during March to July 2007 to evaluate the bioefficacy of some plant extracts in controlling Cercospora leaf spot of mungbean. Six indigenous plant species i.e. Neem leaves extract (1:4 w/v), Garlic cloves extract (1:5 w/v), Biskatali leaves extract (1:4 w/v), Alamanda leaves extract (1:6 w/v), Arjun leaves extract (1:4 w/v) and Debdaru leaves extract (1:5 w/v) were used in this experiment. The experiment was laid out in RCBD with seven treatments and four replications. Data on disease incidence, severity, yield contributing characters and yield of mungbean were recorded. Naturally, infection of the disease was considered in this experiment. The lowest disease incidence (7.33%) at 60 DAS was found in T1. Lowest and similar disease severity (PDI= 4.55) was found in T2 and T3 at the same DAS. Neem extract treated plots gave better response in yield (1.26 t ha-1) and all the yield contributing parameters like inflorescences plant-1 (13.45), tallest plant (51.44 cm), the maximum number of pods plant-1 (26.81), length of pod (8.56 cm), number of seeds pod-1 (12.64) and 1000 seeds weight (27.33 g) followed by T2 and T3. The highest disease incidence (26.50%) and disease index (13.65%) were recorded in treatment T7 at 60 DAS. Yield and all yield contributing factors were lowest in same treatment. The results of the experiment suggested that the use of neem leaves extracts are effective for minimizing Cercospora leaf spot incidence, severity and increasing yield of mungbean. Int. J. Agril. Res. Innov. & Tech. 3 (1): 60-65, June, 2013 DOI: http://dx.doi.org/10.3329/ijarit.v3i1.1609

Detection and Processing Techniques of FECG Signal for Fetal Monitoring

Fetal electrocardiogram (FECG) signal contains potentially precise information that could assist clinicians in making more appropriate and timely decisions during labor. The ultimate reason for the interest in FECG signal analysis is in clinical diagnosis and biomedical applications. The extraction and detection of the FECG signal from composite abdominal signals with powerful and advance methodologies are becoming very important requirements in fetal monitoring. The purpose of this review paper is to illustrate the various methodologies and developed algorithms on FECG signal detection and analysis to provide efficient and effective ways of understanding the FECG signal and its nature for fetal monitoring. A comparative study has been carried out to show the performance and accuracy of various methods of FECG signal analysis for fetal monitoring. Finally, this paper further focused some of the hardware implementations using electrical signals for monitoring the fetal heart rate. This paper opens up a passage for researchers, physicians, and end users to advocate an excellent understanding of FECG signal and its analysis procedures for fetal heart rate monitoring system

Screening of Different Tomato Varieties in Saline Areas of Bangladesh

A field study was conducted to screen out a number of Bangladeshi Tomato (Lycopersicon esculentum L.) varieties for salinity tolerance. Three levels of salinity were 2.0-4.0 dS m-1, 4.1-8.0 dS m-1 and 8.1-12.0 dS m-1. Significant varietal and or salinity treatment effects were registered on plant height, leaf area, plant growth, yield, dry matter plant-1, Na+ and Claccumulation in tomato tissues. Variety BARI Tomato 14, BARI Hybrid Tomato 5 and BARI Tomato 2 consistently showed superior biological activity at moderate salinity (4.1-8.0 dS m-1), based on dry matter biomass production thus displaying relatively greater adaptation to salinity. Under saline condition, all plant parameters of tomato varieties were reduced compared to the control except number of fruits of BARI Tomato 14, BARI Hybrid Tomato 5 and BARI Tomato 2. Thus, BARI Tomato 14, BARI Hybrid Tomato 5 and BARI Tomato 2 can be regarded as a breeding material for development of new tomato varieties for tolerance to salinity in saline areas of Bangladesh. DOI: http://dx.doi.org/10.3329/ijarit.v2i1.13989 Int. J. Agril. Res. Innov. & Tech. 2 (1): 13-18, June, 201

Studies on some morphological characters and yield attributes of synthetic Brassica hexaploids and their parents

Allopolyploidy plays an important role in plant evolution and confers better advantages on crop growth and breeding compared to low ploidy levels. The present investigation aimed to study the synthetic hexaploid Brassica (AABBCC genome) developed from Brassica cainata (BBCC genome) and Brassica rapa (AA genome) compared to their parental genotypes considering some morphological characters, yield attributes and yield. Increased vegetative growth in hexaploids over their parents was observed. Hexaploids exhibited wider ranges with higher coefficients of variations compared to the parents for all characters studied. Hexaploids had taller plants, higher number of siliqua and larger flowers than those of both parents. Though average pollen fertility in the hexaploids was lower than both parents but out of 420 hexaploids, seventeen had comparatively higher percentages of pollen fertility as well as siliqua setting. Number of seeds per siliqua and siliqua length were found to be lower than their parents. Mean seed weight per plant in the hexaploids was lower than the parents though the hexaploids had higher number of siliquae along with higher seed weight. Days to flowering and maturity in the hexaploids were in between the parents and closer to the B. carinata parent. Five hexaploid plants from BARIBatishak-1 × Carinata-1 and two from each of Carinata-1 × BARIBatishak-1 and Agrani × Carinata-1 were found to be promising because they have higher seed yield per plant than their parents. Those nine selected high yielding hexaploid plants could be evaluated in the subsequent generations to select the stable and desirable Brassica hexaploids.Keywords: Brassica hexaploid, morphological characters, yield attribute

Development of a high-sensitivity and short-duration fluorescence in situ hybridization method for viral mRNA detection in HEK 293T cells

Coronavirus disease 2019 (COVID-19) is an extremely contagious illness caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Early disease recognition of COVID-19 is crucial not only for prompt diagnosis and treatment of the patients, but also for effective public health surveillance and response. The reverse transcription-polymerase chain reaction (RT-PCR) is the most common method for the detection of SARS-CoV-2 viral mRNA and is regarded as the gold standard test for COVID-19. However, this test and those for antibodies (IgM and IgG) and antigens have certain limitations (e.g., by yielding false-negative and false-positive results). We have developed an RNA fluorescence in situ hybridization (FISH) method for high-sensitivity detection of SARS-CoV-2 mRNAs in HEK 293T cell cultures as a model. After transfection of HEK 293T cells with plasmids, Spike (S)/envelope (E) proteins and their mRNAs were clearly detected inside the cells. In addition, hybridization time could be reduced to 2 hours for faster detection when probe concentration was increased. Our approach might thus significantly improve the sensitivity and specificity of SARS-CoV-2 detection and be widely applied for the high-sensitivity single-molecular detection of other RNA viruses (e.g., Middle East respiratory syndrome coronavirus (MERS-CoV), Hepatitis A virus, all influenza viruses, and human immunodeficiency virus (HIV)) in various types of samples including tissue, body fluid, blood, and water. RNA FISH can also be utilized for the detection of DNA viruses (e.g., Monkeypox virus, human papillomavirus (HPV), and cytomegalovirus (CMV)) by detection of their mRNAs inside cells or body fluid