99 research outputs found
GROWTH, YIELD AND FATTY ACIDS RESPONSE OF OENOTHERA BIENNIS TO WATER STRESS AND POTASSIUM FERTILIZER APPLICATION
Objective: The objective of this research was to study the effects of water stress treatments (40, 60, and 80 % available soil moisture, ASM) and/or potassium application (0, 0.4 and 0.8 g/pot) on growth parameters, yield and fatty acids content and composition of Oenothera biennis under greenhouse conditions.Methods: A two years pot experiment was conducted on Oenothera biennis under Egypt conditions in 2013/2014 and 2014/2015 seasons. Growth, seed yield (g/plant) and seed fixed oil content recorded at the first and second seasons. The fatty acid profile of total lipids extracted from Oenothera biennis was determined by Gas-liquid chromatography (GLC) analysis.Results: Growth characteristics (plant height, the number of branches, the number of capsules/plant and dry weights of the whole plant, root, and straw), seed yield (g/plant) and oil yield in two seasons were significantly decreased with the rise in water stress levels. Oil % was stimulated in response to water stress. Application of potassium counteracted the adverse effects of water stress. The maximum growth, seed yield and oil yield were obtained from plants irrigated with 80 % available soil moisture (ASM) plus potassium (0.8 g/pot). On the contrary, supplying plants with a water level of 40 % ASM and with potassium (0.8 g/pot) or (0.4 g/pot) gave the best result for the oil percentage in the first and second seasons, respectively. In respect to fatty acids profile, the percentage of C16:0, C18:1n9 and C22:0 acids were increased with increasing water stress while a reverse response was observed in C18:0, C18:2n6, C20:0, C18:3n6 and C20:1n9 acids. K application attenuated oil composition, where it led to a slight increase in C18:2n6 and C20:0 acids while decreased the percentages of C16:0, C18:1n9, C22:0 acids C18:0, C18:3n6 and C20:1n9 acids. Potassium rates plus 60 % ASM increased C18:0 and C18:1n9 acids while K application with both of 60 % ASM and 40 % ASM increased C18:2n6 and C20:0 acids. The C22:0 acids increased under the interaction of all irrigation treatments with (0.4 g/pot) dose of K. However, C16:0 acids increased as a result of 80 % ASM treatment with the different potassium rates. This study demonstrated the beneficial effects of K application to alleviating the adverse effects of water stress on Oenothera plants.Conclusion: Increasing irrigation levels increased the plant height, the number of branches, the number of capsules/plant, seed yield and dry weights of the whole plant, root, and straw of Oenothera biennis and the optimum irrigation level for the highest yields of these variables was 80 % ASM. Whereas, oil % decreased with increasing irrigation levels and the optimum irrigation level for the highest oil % was 40 % ASM. However, for the oil yield from plants that received 80 % ASM produced more oil yield than plants received 60 % or 40 % ASM. Application of potassium counteracted the adverse effects of water stress. Potassium fertilizer increased plant height, the number of branches, the number of capsules/plant, seed yield and dry weights of the whole plant, root, and straw of Oenothera biennis. Application of potassium could be a practical approach for enhancing the oil accumulation in Oenothera biennis. The current study provided important information about the qualitative and quantitative changes in the fatty acids profile of Oenothera biennis in relation to potassium application under water stress conditions.Keywords: Fatty acids, Oenothera biennis, Potassium fertilizer, Water stres
RESPONSE OF GROWTH, ESSENTIAL OIL CONTENT AND ITS CONSTITUENT'S OF PLECTRANTHUS AMBOINICUS TO IRON AND/OR UREA FOLIAR APPLICATION UNDER SALINE IRRIGATION
Objective: To study the response of Plectranthus amboinicus plants to iron and/or urea foliar application using tap water and Nacl saline water for irrigation, a pot experiment was conducted during two successive seasons (2014 and 2015) under the natural conditions of the greenhouse of the National Research Center, Dokki, Giza, Egypt.Methods: Plectranthus amboinicus cuttings were transplanted in the pots in February of each season. After one month, seedlings were irrigated with (2 levels: Tap water (0.40 dsm-1), and Nacl solution (4 dsm-1)) and FeUrea (4 levels: None, EDTA (200 ppm), urea (1000 ppm), and mixture of urea (1000 ppm) and Fe EDTA (200 ppm)) were applied one month from transplanting. The foliar application treatments were sprayed at 60, 90, 120 and 150 d from transplanting. Plant fresh mass (g/plant) and proline content were determined in the first and second cuts after 120 and 180 d from transplanting, respectively. The essential oil was obtained by hydrodistillation and essential oil % was expressed as ml 100 g/fresh herb. The chemical composition of the essential oil was studied using GC-MS and compounds were identified based on their mass spectra and literature.Results: Repeated measures analysis of the data showed significant effects of irrigation and iron/urea on fresh weight of herb, essential oil (%), oil yield, and proline in both first and second cuts. Plectranthus amboinicus plants sprayed with urea/or iron under tap and Nacl saline conditions were better than the control (unsprayed) plants. While saline irrigation decreased fresh weight, essential oil and oil yield, it increased proline; and 200Fe+1000Urea gave significantly higher proline for both tap and Nacl irrigations. Within each irrigation, the highest fresh mass and oil yield were obtained from 200Fe+1000Urea. Fresh mass for tap irrigation was significantly higher during the second cut than during the first cut, but it was the opposite for oil yield. This research demonstrated that application of iron and/or urea decreases salinity stress, and increases proline content. The GC/MS analysis revealed the major components of Plectranthus amboinicus to be p-cymene, carvacrol, (+)-epibicyclosesquiphellandrene, β-cadinene and α-cadinol.Conclusion: It may be concluded that Plectranthus amboinicus is tolerant to Nacl irrigations, thus we may recommend its cultivation in slain soil of Egypt. Foliar spraying with iron and/or urea under these conditions could be much more efficient than the not application of nutrients. So, we recommended that foliar application of iron and/or urea to raise the salt stress tolerance of Plectranthus amboinicus
Whisker touch guides canopy exploration in a nocturnal, arboreal rodent, the Hazel dormouse (Muscardinus avellanarius)
Dormouse numbers are declining in the UK due to habitat loss and fragmentation. We know that dormice are nocturnal, arboreal, and avoid crossing open spaces between habitats, yet how they navigate around their canopy is unknown. As other rodents use whisker touch sensing to navigate and explore their environment, this study investigates whether Hazel dormice (Muscardinus avellanarius) employ their whiskers to cross between habitats. We analysed high-speed video footage of dormice exploring freely in flat and climbing arenas in near darkness and using infrared light illumination. We confirm that, like rats and mice, dormice move their whiskers back and forth continuously (~10 Hz) in a motion called whisking and recruit them to explore small gaps (<10 cm) by increasing the amplitude and frequency of whisking and also the asymmetry of movement between the left and right whisker fields. When gaps between platforms are larger than 10-15 cm dormice spend more time travelling on the floor. These findings suggest that dormice can actively and purposively move their whiskers to gather relevant information from their canopy at night. As this species is vulnerable to threats on the ground, we also provide evidence that joining habitat patches between dormouse populations is important for promoting natural behaviours and movement between patches
Age and gender specific normal values of left ventricular mass, volume and function for gradient echo magnetic resonance imaging: a cross sectional study
<p>Abstract</p> <p>Background</p> <p>Knowledge about age-specific normal values for left ventricular mass (LVM), end-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV) and ejection fraction (EF) by cardiac magnetic resonance imaging (CMR) is of importance to differentiate between health and disease and to assess the severity of disease. The aims of the study were to determine age and gender specific normal reference values and to explore the normal physiological variation of these parameters from adolescence to late adulthood, in a cross sectional study.</p> <p>Methods</p> <p>Gradient echo CMR was performed at 1.5 T in 96 healthy volunteers (11–81 years, 50 male). Gender-specific analysis of parameters was undertaken in both absolute values and adjusted for body surface area (BSA).</p> <p>Results</p> <p>Age and gender specific normal ranges for LV volumes, mass and function are presented from the second through the eighth decade of life. LVM, ESV and EDV rose during adolescence and declined in adulthood. SV and EF decreased with age. Compared to adult females, adult males had higher BSA-adjusted values of EDV (p = 0.006) and ESV (p < 0.001), similar SV (p = 0.51) and lower EF (p = 0.014). No gender differences were seen in the youngest, 11–15 year, age range.</p> <p>Conclusion</p> <p>LV volumes, mass and function vary over a broad age range in healthy individuals. LV volumes and mass both rise in adolescence and decline with age. EF showed a rapid decline in adolescence compared to changes throughout adulthood. These findings demonstrate the need for age and gender specific normal ranges for clinical use.</p
Comparison of the fracture resistance of endodontically treated teeth restored with prefabricated posts and composite resin cores with different post lenghts
OBJECTIVE: This study evaluated the fracture strengths of endodontically treated teeth restored with prefabricated posts with different post lengths. MATERIAL AND METHODS: Thirty freshly extracted canines were endodontically treated. They were randomly divided into groups of 10 teeth and prepared according to 3 experimental protocols, as follows; Group 1/3 PP: teeth restored with prefabricated post and composite resin core (Z250) with post length of 5.0mm; Group 1/2 PP and Group 2/3 PP: teeth restored with prefabricated post and composite resin core (Z250) with different combinations of post length of 7.5mm and 10mm, respectively. All teeth were restored with full metal crowns. The fracture resistance (N) was measured in a universal testing machine (crosshead speed 0.5mm/min) at 45 degrees to the tooth long axis until failure. Data were analyzed by one-way analysis of variance (alpha=.05). RESULTS: The one-way analysis of variance demonstrated no significant difference among the different post lengths (P>;.05) (Groups 1/3 PP = 405.4 N, 1/2 PP = 395.6 N, 2/3 PP = 393.8 N). Failures occurred mainly due to core fracture. CONCLUSIONS: The results of this study showed that an increased post length in teeth restored with prefabricated posts did not significantly increase the fracture resistance of endodontically treated teeth
Immediate continuous passive motion after internal fixation of an ankle fracture
Surgical treatment is usually mandatory in displaced bimalleolar and trimalleolar fractures. Some authors have recommended early mobilization of the ankle joint after surgical treatment of these lesions. In this study, we evaluate the effect of immediate postoperative continuous passive motion in the management of displaced bimalleolar and trimalleolar fractures treated surgically
The Morphology of the Rat Vibrissal Array: A Model for Quantifying Spatiotemporal Patterns of Whisker-Object Contact
In all sensory modalities, the data acquired by the nervous system is shaped by the biomechanics, material properties, and the morphology of the peripheral sensory organs. The rat vibrissal (whisker) system is one of the premier models in neuroscience to study the relationship between physical embodiment of the sensor array and the neural circuits underlying perception. To date, however, the three-dimensional morphology of the vibrissal array has not been characterized. Quantifying array morphology is important because it directly constrains the mechanosensory inputs that will be generated during behavior. These inputs in turn shape all subsequent neural processing in the vibrissal-trigeminal system, from the trigeminal ganglion to primary somatosensory (“barrel”) cortex. Here we develop a set of equations for the morphology of the vibrissal array that accurately describes the location of every point on every whisker to within ±5% of the whisker length. Given only a whisker's identity (row and column location within the array), the equations establish the whisker's two-dimensional (2D) shape as well as three-dimensional (3D) position and orientation. The equations were developed via parameterization of 2D and 3D scans of six rat vibrissal arrays, and the parameters were specifically chosen to be consistent with those commonly measured in behavioral studies. The final morphological model was used to simulate the contact patterns that would be generated as a rat uses its whiskers to tactually explore objects with varying curvatures. The simulations demonstrate that altering the morphology of the array changes the relationship between the sensory signals acquired and the curvature of the object. The morphology of the vibrissal array thus directly constrains the nature of the neural computations that can be associated with extraction of a particular object feature. These results illustrate the key role that the physical embodiment of the sensor array plays in the sensing process
Change in basic motor abilities, quality of movement and everyday activities following intensive, goal-directed, activity-focused physiotherapy in a group setting for children with cerebral palsy
Background: The effects of intensive training for children with cerebral palsy (CP) remain uncertain. The aim of the study was to investigate the impact on motor function, quality of movements and everyday activities of three hours of goal-directed activity-focused physiotherapy in a group setting, five days a week for a period of three weeks. Methods: A repeated measures design was applied with three baseline and two follow up assessments; immediately and three weeks after intervention. Twenty-two children with hemiplegia (n = 7), diplegia (n = 11), quadriplegia (n = 2) and ataxia (n = 2) participated, age ranging 3-9 y. All levels of Gross Motor Function Classification System (GMFCS) and Manual Ability Classification System (MACS) were represented. Parents and professionals participated in goal setting and training. ANOVA was used to analyse change over repeated measures. Results: A main effect of time was shown in the primary outcome measure; Gross Motor Function Measure-66 (GMFM- 66), mean change being 4.5 (p < 0.01) from last baseline to last follow up assessment. An interaction between time and GMFCS-levels was found, implying that children classified to GMFCS-levels I-II improved more than children classified to levels III-V. There were no main or interaction effects of age or anti-spastic medication. Change scores in the Pediatric Evaluation of Disability Inventory (PEDI) ranged 2.0-6.7, p < 0.01 in the Self-care domain of the Functional Skills dimension, and the Self-care and Mobility domains of the Caregiver Assistance dimension. The children's individual goals were on average attained, Mean Goal Attainment Scaling (GAS) T-score being 51.3. Non-significant improved scores on the Gross Motor Performance Measure (GMPM) and the Quality of Upper Extremities Skills Test (QUEST) were demonstrated. Significant improvement in GMPM scores were found in improved items of the GMFM, not in items that maintained the same score. Conclusions: Basic motor abilities and self-care improved in young children with CP after goal-directed activityfocused physiotherapy with involvement of their local environment, and their need for caregiver assistance in self-care and mobility decreased. The individualized training within a group context during a limited period of time was feasible and well-tolerated. The coherence between acquisition of basic motor abilities and quality of movement should be further examined
Fused Traditional and Geometric Morphometrics Demonstrate Pinniped Whisker Diversity
Vibrissae (whiskers) are important components of the mammalian tactile sensory system, and primarily function as detectors of vibrotactile information from the environment. Pinnipeds possess the largest vibrissae among mammals and their vibrissal hair shafts demonstrate a diversity of shapes. The vibrissae of most phocid seals exhibit a beaded morphology with repeating sequences of crests and troughs along their length. However, there are few detailed analyses of pinniped vibrissal morphology, and these are limited to a few species. Therefore, we comparatively characterized differences in vibrissal hair shaft morphologies among phocid species with a beaded profile, phocid species with a smooth profile, and otariids with a smooth profile using traditional and geometric morphometric methods. Traditional morphometric measurements (peak-to-peak distance, crest width, trough width and total length) were collected using digital photographs. Elliptic Fourier analysis (geometric morphometrics) was used to quantify the outlines of whole vibrissae. The traditional and geometric morphometric datasets were subsequently combined by mathematically scaling each to true rank, followed by a single eigendecomposition. Quadratic discriminant function analysis demonstrated that 79.3, 97.8 and 100% of individuals could be correctly classified to their species based on vibrissal shape variables in the traditional, geometric and combined morphometric analyses, respectively. Phocids with beaded vibrissae, phocids with smooth vibrissae, and otariids each occupied distinct morphospace in the geometric morphometric and combined data analyses. Otariids split into two groups in the geometric morphometric analysis and gray seals appeared intermediate between beaded- and smooth-whiskered species in the traditional and combined analyses. Vibrissal hair shafts modulate the transduction of environmental stimuli to the mechanoreceptors in the follicle-sinus complex (F-SC), which results in vibrotactile reception, but it is currently unclear how the diversity of shapes affects environmental signal modulation
Alteration of the phospho- or neutral lipid content and fatty acid composition in Listeria monocytogenes due to acid adaptation mechanisms for hydrochloric, acetic and lactic acids at pH 5.5 or benzoic acid at neutral pH
This study provides a first approach to observe the effects on Listeria monocytogenes of cellular exposure to acid stress at low or neutral pH, notably how phospho- or neutral lipids are involved in this mechanism, besides the fatty acid profile alteration. A thorough investigation of the composition of polar and neutral lipids from L. monocytogenes grown at pH 5.5 in presence of hydrochloric, acetic and lactic acids, or at neutral pH 7.3 in presence of benzoic acid, is described relative to cells grown in acid-free medium. The results showed that only low pH values enhance the antimicrobial activity of an acid. We suggest that, irrespective of pH, the acid adaptation response will lead to a similar alteration in fatty acid composition [decreasing the ratio of branched chain/saturated straight fatty acids of total lipids], mainly originating from the neutral lipid class of adapted cultures. Acid adaptation in L. monocytogenes was correlated with a decrease in total lipid phosphorus and, with the exception of cells adapted to benzoic acid, this change in the amount of phosphorus reflected a higher content of the neutral lipid class. Upon acetic or benzoic acid stress the lipid phosphorus proportion was analysed in the main phospholipids present: cardiolipin, phosphatidylglycerol, phosphoaminolipid and phosphatidylinositol. Interestingly only benzoic acid had a dramatic effect on the relative quantities of these four phospholipids
- …
