Mechanical behaviour of plum fruits as affected by preharvest methyl jasmonate applications

In this study, the effects of preharvest methyl jasmonate (MeJA) applications on the mechanical behaviour of plum fruits (cv. ‘President’) were investigated.  The mechanical behaviour of plum fruits to compression affected by different harvesting time were determined in terms of rupture force, specific deformation, rupture energy, toughness and rupture power at constant compression speed of 62.4 mm min-1.  Quasi-static compression loading of plum fruits were conducted at three compression axes (X- Y- and Z- axis) under application of different doses of MeJA before the harvest.  MeJA doses were as  0 mg L-1, 1,120 mg L-1, and 2,240 mg L-1 harvested on the different days viz. 28 August, 4 September and 11 September.   The force required to initiate plum rupture on each axis decreased as MeJA doses increased from 1,120 mg L-1 MeJA to   2,240 mg L-1 MeJA.  The rupture energy and rupture power values observed for plum fruits compressed along the Y- axis were higher than the values obtained when testing plum fruits in the X- and Z-axis orientations.  The results indicated that the rupture force and rupture energy along all three axes are highly dependent on MeJA applications.  These finding could therefore be useful in predicting the mechanical behaviour of plum fruits.   Keywords: plum, methyl jasmonate, rupture force, rupture energy, rupture powe

THE EFFECTS OF AMINOETHOXYVINYLGLYCINE AND METHYL JASMONATE ON BIOACTIVE COMPOUNDS AND FRUIT QUALITY OF ‘NORTH WONDER’ SWEET CHERRY

Background: AVG is an organic ethylene inhibitor. AVG treatments retarded the ripening process, increased fruit sizes and delayed loss postharvest fruit flesh firmness by inhibiting ethylene. MeJA is a natural plant growth regulator and plays a regulatory role in various reactions. Apart from its role in fruit ripening, cell activities like anthocyanin and carotenoid synthesis and inhibitive role in aromatic formation, chlorophyll and lycopene production. Materials and Methods: The present study was conducted to determine the effects of pre-harvest aminoethoxyvinylglycine (AVG) and jasmonate (MeJA) treatments on bioactive compounds, mineral nutrients and other fruit quality characteristics of ‘North Wonder’ sweet variety in 2011. sprayed on experimental trees at 125 mg L-1 dose in two different periods i.e. 3 weeks and 2 weeks before anticipated harvest date. MeJA was applied 3 week before the anticipated harvest date at a dose of 2240 mg L-1 .Results: MeJA significantly increased fruit weight and geometric mean diameter. AVG significantly decreased fruit weight and flesh/stone significantly increased L*, chroma and hue angle values. Effects of both AVG and MeJA on flesh firmness were also found to be significant. While soluble solids concentration and pH values significantly decreased with AVG treatment, titrate acidity significantly increased. Both and MeJA treatments significantly decreased total phenolics (TP), total antioxidant capacity (TAC) and total anthocyanin (TA). Effects on such decreases in TAC and TA were more efficient than MeJA. While the effects of both AVG and MeJA on iron content were significant, effects of only MeJA on nitrogen and phosphor contents were found to be significant. Conclusion: Growth regulators significantly decreased bioactive compounds. AVG was more effective in such decreases than MeJA

EFFECTS OF PRE-HARVEST METHYL JASMONATE TREATMENT ON POST-HARVEST FRUIT QUALITY OF JAPANESE PLUMS

Background: Plum fruits constitute a good source of natural antioxidant substances. Particularly, plums contain large amounts of phenolic compounds and flavonoids having natural antioxidant activity which is effective in human diet. The aim of this study was to evaluate the effects of pre-harvest MeJA treatment on the fruit quality and bioactive compounds of three different Japanese plums under storage conditions. Materials and Methods: The effects of pre-harvest methyl jasmonate treatment (MeJA) on weight loss, color characteristics (L*, C* and h°), firmness, soluble solids content (SSC), titratable acidity (TA), total phenolics (TP) and total antioxidant activity (TAA) of ‘Black Beauty’, ‘Black Amber’ and ‘Fortune’ plum fruits during the cold storage (at 0±0.5 C and 90±5% RH) were investigated in this study. Results: MeJA did not have significant effects on the weight loss (%) of ‘Black Amber’ and ‘Fortune’ fruits, whereas it was effective in delaying the weight loss of ‘Black Beauty’ at the end of storage. The color characteristics of all plum cultivars were not significantly affected by MeJA at the end of storage. In all plum cultivars, the SSC increased, while TA significantly (

Continuous positive airway pressure increases CSF flow and glymphatic transport

Respiration can positively influence cerebrospinal fluid (CSF) flow in the brain, yet its effects on central nervous system (CNS) fluid homeostasis, including waste clearance function via glymphatic and meningeal lymphatic systems, remain unclear. Here, we investigated the effect of supporting respiratory function via continuous positive airway pressure (CPAP) on glymphatic-lymphatic function in spontaneously breathing anesthetized rodents. To do this, we used a systems approach combining engineering, MRI, computational fluid dynamics analysis, and physiological testing. We first designed a nasal CPAP device for use in the rat and demonstrated that it functioned similarly to clinical devices, as evidenced by its ability to open the upper airway, augment end-expiratory lung volume, and improve arterial oxygenation. We further showed that CPAP increased CSF flow speed at the skull base and augmented glymphatic transport regionally. The CPAP-induced augmented CSF flow speed was associated with an increase in intracranial pressure (ICP), including the ICP waveform pulse amplitude. We suggest that the augmented pulse amplitude with CPAP underlies the increase in CSF bulk flow and glymphatic transport. Our results provide insights into the functional crosstalk at the pulmonary-CSF interface and suggest that CPAP might have therapeutic benefit for sustaining glymphatic-lymphatic function

A aplicação de doses de AVG desempenha um papel importante na queda, pré-colheita e maturação de maçãs ‘Jonagold’

This study was carried out to investigate the effects of different AVG (aminoethoxyvinylglycine) treatments on pre-harvest fruit drop rates and ripening levels of ‘Jonagold’ apples. A total of 225 mg L-1 AVG dose was applied at once in a single application at different times or divided into doses and applied different times. Compared to control treatment, entire AVG treatments increased fruit removal force and significantly decreased the pre-harvest drop rates. AVG treatments applied at once (225 mg L-1) 8 or 4 weeks before the anticipated harvest time were found to be more effective than the divided treatments. AVG treatments inhibited ethylene biosynthesis and such an inhibition was more distinctive in single 225 mg L-1 treatments. AVG treatments decreased flesh softening, starch degradation rates and consequently retarded fruit ripening. The 225 mg L-1 AVG treatment applied 4 weeks before the harvest significantly increased L* value and hue angle both in the year 2010 and 2011. NAA (naphtaleneacetic acid) at 10 mg L-1 sprayed 4 and 2 weeks before anticipated harvest was found to be insignificant in control of pre-harvest fruit drops. NAA treatment decreased flesh firmness, and did not have any significant effects on ethylene biosynthesis.O presente estudo foi realizado para investigar os efeitos de diferentes tratamentos AVG (aminoetoxivinilglicina) sobre as taxas de queda de frutos antes da colheita e níveis de amadurecimento de maçãs ‘Jonagold’. Foi aplicada uma dose AVG total de 225 mg L-1 numa só vez numa única aplicação em momentos diferentes ou dividida em doses aplicadas e tempos diferentes. Em comparação ao tratamento controle, as aplicações de AVG aumentaram a força de remoção dos frutos e reduziram significativamente as taxas de queda na pré-colheita. A aplicação de AVG de uma só vez (225 mg L-1) ou 4 a 8 semanas antes da época da colheita mostrou-se mais eficaz do que as aplicações efetuadas em doses. O tratamento com AVG inibe a biossíntese de etileno, sendo que esta inibição se verificou mais significativa em tratamentos individuais de 225 mg L-1. O tratamento com AVG diminuiu o amolecimento da polpa, as taxas de degradação do amido e consequentemente retardou o amadurecimento dos frutos. O tratamento com doses de 225 mg L-1 de AVG aplicadas quatro semanas antes da colheita aumentou significativamente o valor L * e o ângulo de cor, tanto no ano de 2010 como de 2011. A pulverização de NAA (ácido naftaleno acético) a 10 mg L-1 2 a 4 semanas antes da colheita foi considerada insignificante no controle da queda de frutos na pré-colheita. O tratamento com NAA diminuiu a firmeza da polpa, e não tem quaisquer efeitos significativos sobre a síntese de etileno

Comparison of prestressed concrete railway sleepers and new LCR concrete sleepers with experimental modal analysis

Rail operations today have become more difficult due to increasing operating speeds and decreasing maintenance times. Today's higher frequency train loads are more detrimental, and prestressed railway sleepers especially are susceptible to these dynamic loads. Laminated carbon fiber reinforced polyurethane (L-CFRPU) reinforced concrete railway sleeper models (LCR concrete sleepers) have the potential to exhibit higher damping and resonance resistance more economically and practically. In this study, experimental modal analysis was performed on a large number of samples produced to understand the damping characteristics of sleepers. According to the results, new LCR concrete sleepers have extremely higher damping ratios of over 50% and are expected to be beneficial in extending the service life of the railway components, reducing maintenance needs and harmful effects on the environment

Comparative modal analysis of B70 and LCR-6 type railway sleepers after repeated impact loads

Due to today's high-frequency trainloads and wheel or rail irregularities, the railway system is more exposed to impact loading conditions. In this study, laminated carbon fiber reinforced polyurethane (L-CFRPU) products were used, with a new non-pre-stressed production process, to improve the impact damping characteristics of concrete railway sleepers. New designed LCR-6 type sleepers were compared with standard B70 type pre-stressed concrete sleepers by performing modal analysis before and after a 50 times repeated-330 kN impact loading procedure. This is the first study to compare new LCR-6 type sleepers with prestressed competitors after impact loads. According to the analysis results, FRF magnitude values decrease up to 83% lower in impacted LCR-6 type sleepers compared to impacted B70 type sleepers. After the impact loading procedure, the cracks formed in LCR6 type sleepers closed and remained below 50-mu m width, and according to the simultaneous mechanical test results, these few hairline cracks do not cause a significant mechanical capacity loss, while increasing the damping ratios by 274%. This advantage will be beneficial in extending the service life of sleepers and protecting other railway components from vibration and impact damage. Therefore, while the pre-stressed concrete sleepers have a negative course during their service life, the non-pre-stressed LCR type sleepers show a positive acceleration

Effect of aminoethoxyvinylglycine on biochemical, physicomechanical and colour properties of cv. Braeburn apples

Foram determinados os efeitos do tratamento em pré-colheita com aminoetoxivinilglicina (AVG) nas propriedades bioquímicas, físico-mecânicas e características da cor da maçã ‘Braeburn’. AVG foi aplicado quatro semanas antes da data estimada de colheita, em quatro doses (0, 100, 300 e 500 mgL- 1). Enquanto os menores valores de sólidos solúveis totais e pH foram obtidos no tratamento com 500 mgL-1 AVG, os maiores valores foram obtidos no tratamento com 0 mgL-1 AVG. A acidez titulável foi maior no tratamento com 500 mgL-1 AVG do que nos tratamentos 100 e 300 mgL-1. A maior atividade de fenólicos totais e antioxidantes na polpa e na casca da maçã foi obtida no tratamento com 0 mgL-1 AVG, enquanto que o menor valor foi obtido no tratamento com 500 mgL-1 AVG. Com o aumento das doses de AVG, a antocianina monomérica total foi reduzida. As médias geométricas diâmetro do fruto, massa do fruto, força de remoção de frutas, polpa e casca aumentaram com o aumento das doses de AVG. Os valores do ângulo da matriz de polpa e casca da fruta foram menores no tratamento com 0 mgL-1 AVG.The effect of preharvest AVG (aminoethoxyvinylglycine) treatments on the biochemical, physicomechanical properties and colour characteristics of cv. Braeburn apples were determined. AVG was applied in four different doses (0, 100, 300 and 500 mgL-1 AVG) 4 weeks before the estimated harvest date. While the lowest values of total soluble solid content and pH were obtained from 500 mgL-1 AVG treatment, the highest values were obtained from control. The titratable acidity was higher in 500 mgL-1 AVG treatment than those of the 100 and 300 mgL-1 AVG treatments. The highest total phenolic and antioxidant activity of both flesh and skin apple was obtained from control, whereas lowest value was obtained from 500 mgL-1 AVG treatment. With increasing doses of AVG, the total monomeric anthocyanin was reduced. The geometric means: fruit diameter, fruit mass, fruit removal force, flesh and skin firmnesses increased with increasing doses of AVG. The hue angle values of flesh and skin fruit were lower in control