RÉSUMÉ
Nitrogen is a crucial element for all living organisms especially plants which rely on substantial nitrogen quantities to sustain their growth and productivity. Crop production is greatly influenced by nitrogen consumption efficiency and a significant amount of nitrogen fertilizers is used to increase yield. Approximately half of N fertilizers are not utilized by the crops and are lost to the environment by polluting water sources or by releasing pollutants into the atmosphere. From the rhizosphere, plants absorb nitrogen in the form of nitrate (NO3-), ammonium (NH4+), or organic nitrogen (amino acids and urea). Plants exhibit an array of sensing and adaptive mechanisms to respond to the diverse nitrogen nutrition conditions which include morphological and physiological responses. Two primary systems govern nitrogen uptake in plants: the High-affinity transport system (HATS) and the Low-affinity transport system (LATS). Nitrate transporters fall into two categories, Nitrate Transporter 1 (NRT1) and Nitrate Transporter 2 (NRT2) transporters, Chloride Channel Family (CLC) transporters and Slow Anion Associated Channel Homologs (SLAC/SLAHs). The ammonium transporter family includes Ammonium Transporter 1 (AMT1) and Ammonium Transporter 2 (AMT2) transporters. The uptake of organic nitrogen is facilitated through amino acid and urea uptake and transport systems. In fluctuating environmental conditions, plants employ nitrogen response mechanisms to fine-tune homeostasis. A comprehensive understanding of these regulatory mechanisms holds the potential to yield valuable insights for the development of crops with enhanced nitrogen use efficiency.
RÉSUMÉ
The experiment was carried out during 2020-2021 at the Department of Plant Physiology, College of Agriculture, Vellayani, Kerala Agricultural University. The experiment was carried out with the aim of characterization of contrasting tomato genotypes for high temperature tolerance under high temperature condition and control condition to identify key quality and yield traits controlling high temperature tolerance in tomato. The experiment was designed in completely randomized design (CRD) with 2 treatment levels- control and high temperature conditions (36+/-2oC) wherein 3 tolerant and 3 susceptible genotypes were selected for the study. These genotypes were selected from the summer varietal screening experiment performed during the summer months of 2021 from March to May. The best performing genotypes were selected in terms of pollen viability, leaf membrane thermo-stability, chlorophyll fluorescence, number of fruits, fruit set %. One set of treatment was maintained under ambient condition and the other set with high temperature stress was maintained under polyhouse facility from transplanting stage to the harvesting stage. The quality parameters and yield traits were analysed at the harvesting stage of the crop. From this study it can be understood that many of the quality parameters like lycopene content, total sugars, flavanol content was found decreasing in both tolerant and susceptible genotypes but the extend of this reduction was considerate in tolerant ones. In case of ascorbic acid content and firmness of fruit at the time of ripening these were found to be improved in heat stress (HS) conditions. Yield related qualities like number of fruits, yield per plant, and root-shoot ratio was found decreasing whereas root dry weight, total dry weight and intensity of fruit drop and flower drop was increased under HS. Therefore, this study focused on tomato genotypes reported to be resilient to high-temperature stress, and comparing them to the susceptible cultivars under stress and control settings for analyzing the variations in terms of quality and yield traits in tropical hot climate regions of India. The study performed here highlights the possibility for future breeding programs utilizing the key quality and yield traits enhancing thermo-tolerance in tomato and to develop new genotypes that can combine good yield performances and fruit nutritional quality at high temperatures.
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Abstract Introduction Temporomandibular joint disorders (TMD) present with a multitude of symptoms that can range from headaches to shoulder pain. Patients frequently present with pain in the ear, dizziness, and vertigo. It is noted that some patients who report TMDs also have a history of sleep disturbances, which is noted in cone beam computed tomography (CBCT) as a reduction in the oropharyngeal airway volume. Objective To evaluate the airway volume in pre- and posttreatment of TMD with the use of neuromuscular orthotics made with ultra-low frequency transcutaneous electrical nerve stimulation (ULF-TENS). Methods A total of 15 patients were evaluated for TMDs using the related criteria. Those included were treated with ULF-TENS with evaluation of the airway volume both pre- and posttreatment using CBCT and the Dolphin 3D volume analysis software. Results While the symptoms were shown to be significantly reduced in patients who were treated with this particular modality, the airway volume varied in those who reported a reduction after a period of 3 months and those that reported after a period of 6 months. Conclusion Posttreatment evaluation of the airway should be done after a period of 6 months for a more objective evaluation. A multidisciplinary evaluation of the patient is required in such cases.
RÉSUMÉ
The main advantage of nickel titanium instruments is that they permit canal preparation with less transportation and ledging. Hand used Ni-Ti and rotary Ni-Ti instruments have a wider range of elastic deformation and greater flexibility. The aim of the present study was to evaluate and compare the preparation time, loss of working length, apical transportation, instrument deformation and fracture with stainless steel, Ni-Ti hand and Ni-Ti rotary endodontic instruments. Fifty freshly extracted human mandibular molars with curved roots were collected and stored in 10% formalin. The samples were divided into 3 groups of 15 each. The access opening was made for each tooth and the biomechanical preparation was carried out using crown down pressureless technique in all the groups. Group I was instrumented with stainless steel files, group II with hand Ni-Ti and group III with Ni-Ti rotary files. The preparation time to enlarge each canal was recorded in minutes and seconds, which included only active instrumentation. Following preparation, the final length of each canal was subtracted from the original length to give the loss of working length. SEM photographs of the deformed and fractured instruments were taken. The apical transportation was measured using computer software (Microdraw 4.1). The readings were noted and statistically analyzed. The results of this in vitro study showed that the mean preparation time was less with Ni- Ti rotary (1.85 min) when compared to hand Ni-Ti (6.33) and stainless steel files (6.73), which was statistically significant. The loss of working length was more for stainless steel group which was statistically significant (P<0.05) when compared with the other 2 groups.One instrument in stainless steel and one in Ni-Ti rotary files were fractured. Only one instrument in stainless steel file deformed permanently. Apical transportation was found to be greater in stainless steel group than other groups (P<0.01) which was statistically significant. Considering the parameters in this study, Ni-Ti rotary files proved to perform better than the other two groups.