Investigation of Growth Indices and Gas Exchanges in Two Cultivars of Sweet William (Dianthus barbatus) under Salinity Stress

Introduction  Salinity stress impairs the absorption of elements such as potassium, leads to decrease in water and minerals, or due to an increase in Na+ effects the absorption of other elements. Salinity of water and soil is one of the obstacles to the expansion of agriculture in most part of the world. Salinity causes several physiological and morphological changes in plants and affects growth and photosynthesis. Salinity stress also affects the absorption of nutrients, and finally the plants sensitivity to stress increases. High concentrations of Nacl in rhizosphere reduce the water potential and cause physiological drought stress. In addition, salinity stress can cause ion toxicity and imbalance, which can damage the plant. Salinity stress has been shown to reduce plant biomass by decreasing photosynthetic capacity and chlorophyll content. As stress increases, stomatal conductance and CO2 assimilation decrease, which both negatively impact photosynthesis and lead to a decrease in plant growth. Dianthus is an annual or perennial plant that produces velvety flowers in various colors. Due to its resistance to cold and wide range of colors, it is commonly used in landscaping. However, limited research has been conducted on the response of Dianthus to environmental stress, making it important to investigate its behavior under such conditions. Material and Method  This research was conducted at greenhouse of municipality of Khomein, Iran. The statistical design was used in the factorial experiment based on CRD. Experimental factors included salinity stress (0, 10, 20, 30, 40, 50, 60, 70, 80, 90 mM) and cultivars (Barbarin and Diana). After preparing the seeds, it is first disinfected using sodium hypochlorite and then planted in plastic pots containing soil, sand and manure. At the end of the experiment, morphological traits, stomatal conductance, photosynthesis rate, Na+, K+ and Na+/K+ was also examined. Gas exchanges were measured using an exchange measuring device (LCA4, ADC Bioscientific,Ltd., Hoddesdon, England). At the time of measuring gas exchanges, the temperature under chamber was 26-29 C and relative humidity was 58-62%. (stomatal conductivity is based on mmol/m2/s and photosynthesis in µmol/m2/s). To measure the concentration of Na+ and K+, the leaf first turned to ash (at 550 C). Then 5 ml of hydrochlorid was added to dissolve the sample and the volume of the filtered solution was reduced to 50 ml with distilled water and the concentration of Na+ and K+ was measured with flame meter. In order to measure the fresh weight of leaves and roots, plant components were separated. Fresh weight was recorded with a scale and then samples were placed in the oven (for 48 h) and weighted again to measure dry weight. Leaf area was measured with a leaf guuge device (A30325) and plant height and root length using a ruler. Statistical analysis of data was performed using Mini Tab and Excel software. Results and Discussion  Results showed that salinity stress generally affected the growth of both carnation cultivars and reduced vegetative and reproductive growth. According to the results obtained from the study, fresh and dry weight of shoot, root and leaves, root length, plant height, stem diameter, diameter and number of flower, lateral shoot number, stomatal conductance, photosynthesis rate, K+ concentration in Diana and Barbarin cultivars decreased with increasing salinity level. Na+ concentration and Na+/K+ increased with increasing salinity and these two traits were higher in Diana than Barbarin cultivar, which indicates lower resistance of Diana cultivar. The plant's first response to stress is to reduce its leaf area, which reduces the supply of photosynthetic material to the growing parts and consequently hinders growth and flowering. Salinity stress and high osmotic potential in the rhizosphere greatly affect photosynthesis as they decrease pore conductivity. Moreover, excessive absorption of Na+ can interfere with the absorption of other elements, thereby restricting plant growth. Potassium (K+) is an essential inorganic molecule that plays a crucial role in increasing plant resistance to stress. It helps in maintaining turbidity, promoting cell development, and regulating stomatal function. In this study, salinity stress affected the growth and yield of both carnation cultivars, and with increasing stress, all morphological traits decreased. This stress also reduce photosynthesis by reducing stomatal conductance and subsequently reduce other growth characteristics. Growth reduction was observed at high salinity stress concentrations in both cultivars. However, barbarin cultivar showed higher resistance than Dian

Исследование влияния технологического процесса изготовления обмоток на дефектность корпусной изоляции асинхронных двигателей

В работе проведено исследование влияния колебаний режимов работы статорообмоточных станков WST-660 и пазоизолировочных станков ИПС-3 на дефектность корпусной изоляции. Получены математические модели дефектообразования в корпусной изоляции обмотки с учетом режимов работы технологического оборудования и качества материала корпусной изоляции в состоянии поставки. Установлено, что изменением режимов работы технологического оборудования можно добиться требуемого качества корпусной изоляции при максимальной производительности оборудования

Superradiance Transition in Photosynthetic Light-Harvesting Complexes

We investigate the role of long-lasting quantum coherence in the efficiency of energy transport at room temperature in Fenna-Matthews-Olson photosynthetic complexes. The excitation energy transfer due to the coupling of the light harvesting complex to the reaction center ("sink") is analyzed using an effective non-Hermitian Hamiltonian. We show that, as the coupling to the reaction center is varied, maximal efficiency in energy transport is achieved in the vicinity of the superradiance transition, characterized by a segregation of the imaginary parts of the eigenvalues of the effective non-Hermitian Hamiltonian. Our results demonstrate that the presence of the sink (which provides a quasi--continuum in the energy spectrum) is the dominant effect in the energy transfer which takes place even in absence of a thermal bath. This approach allows one to study the effects of finite temperature and the effects of any coupling scheme to the reaction center. Moreover, taking into account a realistic electric dipole interaction, we show that the optimal distance from the reaction center to the Fenna-Matthews-Olson system occurs at the superradiance transition, and we show that this is consistent with available experimental data.Comment: 9 page

Symbolic powers of monomial ideals and Cohen-Macaulay vertex-weighted digraphs

In this paper we study irreducible representations and symbolic Rees algebras of monomial ideals. Then we examine edge ideals associated to vertex-weighted oriented graphs. These are digraphs having no oriented cycles of length two with weights on the vertices. For a monomial ideal with no embedded primes we classify the normality of its symbolic Rees algebra in terms of its primary components. If the primary components of a monomial ideal are normal, we present a simple procedure to compute its symbolic Rees algebra using Hilbert bases, and give necessary and sufficient conditions for the equality between its ordinary and symbolic powers. We give an effective characterization of the Cohen--Macaulay vertex-weighted oriented forests. For edge ideals of transitive weighted oriented graphs we show that Alexander duality holds. It is shown that edge ideals of weighted acyclic tournaments are Cohen--Macaulay and satisfy Alexander dualityComment: Special volume dedicated to Professor Antonio Campillo, Springer, to appea

Bonding mechanism from the impact of thermally sprayed solid particles

Power particles are mainly in solid state prior to impact on substrates from high velocity oxy-fuel (HVOF) thermal spraying. The bonding between particles and substrates is critical to ensure the quality of coating. Finite element analysis (FEA) models are developed to simulate the impingement process of solid particle impact on substrates. This numerical study examines the bonding mechanism between particles and substrates and establishes the critical particle impact parameters for bonding. Considering the morphology of particles, the shear-instability–based method is applied to all the particles, and the energy-based method is employed only for spherical particles. The particles are given the properties of widely used WC-Co powder for HVOF thermally sprayed coatings. The numerical results confirm that in the HVOF process, the kinetic energy of the particle prior to impact plays the most dominant role in particle stress localization and melting of the interfacial contact region. The critical impact parameters, such as particle velocity and temperature, are shown to be affected by the shape of particles, while higher impact velocity is required for highly nonspherical powder

Herschel/HIFI deepens the circumstellar NH3 enigma

Circumstellar envelopes (CSEs) of a variety of evolved stars have been found to contain ammonia (NH3) in amounts that exceed predictions from conventional chemical models by many orders of magnitude. The observations reported here were performed in order to better constrain the NH3 abundance in the CSEs of four, quite diverse, oxygen-rich stars using the NH3 ortho J_K = 1_0 - 0_0 ground-state line. We used the Heterodyne Instrument for the Far Infrared aboard Herschel to observe the NH3 J_K = 1_0 - 0_0 transition near 572.5 GHz, simultaneously with the ortho-H2O J_Ka,Kc = 1_1,0 -1_0,1 transition, toward VY CMa, OH 26.5+0.6, IRC+10420, and IK Tau. We conducted non-LTE radiative transfer modeling with the goal to derive the NH3 abundance in these objects' CSEs. For the latter two stars, Very Large Array imaging of NH3 radio-wavelength inversion lines were used to provide further constraints, particularly on the spatial extent of the NH3-emitting regions. Results. We find remarkably strong NH3 emission in all of our objects with the NH3 line intensities rivaling those obtained for the ground state H2O line. The NH3 abundances relative to H2 are very high and range from 2 x 10-7 to 3 x 10-6 for the objects we have studied. Our observations confirm and even deepen the circumstellar NH3 enigma. While our radiative transfer modeling does not yield satisfactory fits to the observed line profiles, it leads to abundance estimates that confirm the very high values found in earlier studies. New ways to tackle this mystery will include further Herschel observations of more NH3 lines and imaging with the Expanded Very Large Array.Comment: 4+2 page

Thermal inactivation and conformational lock studies on glucose oxidase

In this study, the dissociative thermal inactivation and conformational lock theories are applied for the homodimeric enzyme glucose oxidase (GOD) in order to analyze its structure. For this purpose, the rate of activity reduction of glucose oxidase is studied at various temperatures using b-D-glucose as the substrate by incubation of enzyme at various temperatures in the wide range between 40 and 70 �C using UV–Vis spectrophotometry. It was observed that in the two ranges of temperatures, the enzyme has two different forms. In relatively low temperatures, the enzyme is in its dimeric state and has normal activity. In high temperatures, the activity almost disappears and it aggregates. The above achievements are confirmed by dynamic light scattering. The experimental parameter ‘‘n’’ as the obvious number of conformational locks at the dimer interface of glucose oxidase is obtained by kinetic data, and the value is near to two. To confirm the above results, the X-ray crystallography structure of the enzyme, GOD (pdb, 1gal), was also studied. The secondary and tertiary structures of the enzyme to track the thermal inactivation were studied by circular dichroism and fluorescence spectroscopy, respectively. We proposed a mechanism model for thermal inactivation of GOD based on the absence of the monomeric form of the enzyme by circular dichroism and fluorescence spectroscopy

Observations of the circumstellar water 110 → 110 and ammonia 110 → 00 lines in IRC +10216 by the Odin satellite

Submillimeter lines of H 2O and NH 3 have been detected in the carbon star IRC +10216 (CW Leo) with the Odin submillimeter satellite. The detection of the J K-, K+ = 1 10 → 1 10 557 GHz line of ortho-H 2O confirms the earlier detection in the same source with SWAS. The detection of the J K = 1 0 rarr; 0 0 572 GHz line represents the first observation of the ground-state rotational transition of NH 3 in a stellar envelope. By fitting a molecular line transfer model to the observed lines, we derive an ortho-H 20 abundance of 2.4 × 10 -6, which is consistent with estimates from the SWAS observation. The derived ortho-NH 3 abundance of 1 × 10 -6 relative to H 2 is significantly higher than those derived from 24 GHz inversion transitions and is slightly higher than those from vibrational transitions in the infrared band. The high H 2O and NH 3 abundances in the carbon-rich star IRC+10216 underscore shortcomings in the conventional gas-phase LTE and non-LTE chemical models. © 2006. The American Astronomical Society. All rights reserved.published_or_final_versio

Benefícios do ômega 3 na prevenção de doença cardiovascular: Revisão integrativa de literatura

Introduction: Omega-3 polyunsaturated fatty acids such as alpha-linolenic acid (ALA), a fat found in plant foods, and eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), both found in fish, have been considered relevant substances for the maintenance of health, so that supplementation is being considered relevant for the reduction of cardiovascular risks. Objective: To identify and analyze the scientific evidence available in the literature on the contribution of omega 3 in the prevention and treatment of cardiovascular disease. Materials and Methods: Integrative literature review, with deference to materials published in the Scielo and PubMed databases, which considered as inclusion criteria articles published in the last 5 years, available in full, in English, Spanish, and Portuguese, which addressed the proposed theme; the exclusion criteria were editorials, letters to the editor, review studies, theses, dissertations, and duplicate articles that did not correspond to the theme. Results: Based on the aforementioned scientific evidence, the body's omega-3 indices are relevant to identify possible cardiovascular risk, so it can therefore be used as an objective for treatment when there is a possible risk for these manifestations. This risk factor can be modified by taking EPA and DHA. The standard 1 g/day dose of EPA and DHA recommended by cardiac societies is, however, probably far from ideal for everyone, as not only this standard dose but also diet, individual genetic history, body mass index, calorie intake and disposal, and other factors all together probably determine a person's level of omega-3 fatty acids. Therefore, it is suggested that the omega-3 index acts not only as a risk factor for cardiovascular disease, but that other contexts allied to the patient's lifestyle should be considered. Conclusion: Diet or supplementation of these nutrients may result in cardiovascular and other types of benefits to society as a whole