Comparative and Interactive Effects of Reduced Precipitation Frequency and Volume on the Growth and Function of Two Perennial Grassland Species

2014 ◽  
Vol 175 (6) ◽  
pp. 702-712 ◽  
Author(s):  
Adam C. Schneider ◽  
Tali D. Lee ◽  
Molly A. Kreiser ◽  
Gregory T. Nelson
Keyword(s):  
Interactive Effects ◽  
Precipitation Frequency ◽  
Grassland Species ◽  
Perennial Grassland ◽  
And Function

scholarly journals Interactive effects of denervation and malnutrition on diaphragm structure and function

1996 ◽  
Vol 81 (5) ◽  
pp. 2165-2172 ◽  
Author(s):  
Michael I. Lewis ◽  
Thomas J. Lorusso ◽  
Wen-Zhi Zhan ◽  
Gary C. Sieck
Keyword(s):  
Fiber Type ◽  
Structure And Function ◽  
Interactive Effects ◽  
Diaphragm Muscle ◽  
Fiber Types ◽  
Specific Force ◽  
Cross Sectional ◽  
Total Cross Sectional Area ◽  
Generating Capacity ◽  
And Function

Lewis, Michael I., Thomas J. Lorusso, Wen-Zhi Zhan, and Gary C. Sieck. Interactive effects of denervation and malnutrition on diaphragm structure and function. J. Appl. Physiol. 81(5): 2165–2172, 1996.—The purpose of this study was to examine the interactive effects of unilateral denervation (DN) and prolonged malnutrition (MN) on the structure and function of the diaphragm muscle (Dia). Four groups of rats were studied: control (Con), MN, DN, and DN-MN. MN began 2 wk after DN and lasted 4 wk. In both the DN and DN-MN groups, the relative loss in Dia weight exceeded the relative change in body weight. Compared with the Con group, Dia specific force was reduced by ∼40% in both the DN and DN-MN groups but was unaffected in the MN group. Dia fatigue resistance improved in all experimental groups but to a greater extent in the DN and DN-MN groups. In both the DN and DN-MN groups, ∼50% of Dia fibers were classified as type IIc, whereas fiber type proportions did not change in the MN group. In the DN group, only type IIb/x fibers atrophied, whereas all fiber types atrophied in the MN and DN-MN groups. We conclude that in the DN-MN group the reduction in specific force combined with the reduction in total cross-sectional area of the muscle significantly curtails Dia force-generating capacity.

Native Perennial Grassland Species for Bioenergy: Establishment and Biomass Productivity

2011 ◽  
Vol 103 (2) ◽  
pp. 509-519 ◽  
Author(s):  
Margaret E. Mangan ◽  
Craig Sheaffer ◽  
Donald L. Wyse ◽  
Nancy J. Ehlke ◽  
Peter B. Reich
Keyword(s):  
Biomass Productivity ◽  
Grassland Species ◽  
Perennial Grassland

scholarly journals Androgen Regulates Brain-Derived Neurotrophic Factor in Spinal Motoneurons and Their Target Musculature

Endocrinology ◽  
2010 ◽  
Vol 151 (1) ◽  
pp. 253-261 ◽  
Author(s):  
Tom Verhovshek ◽  
Yi Cai ◽  
Mark C. Osborne ◽  
Dale R. Sengelaub
Keyword(s):  
Neurotrophic Factor ◽  
Vastus Lateralis ◽  
Brain Derived Neurotrophic Factor ◽  
Neural System ◽  
Dendritic Morphology ◽  
Trophic Factors ◽  
Interactive Effects ◽  
Neuromuscular System ◽  
Spinal Motoneurons ◽  
And Function

Abstract Trophic factors maintain motoneuron morphology and function in adulthood. Brain-derived neurotrophic factor (BDNF) interacts with testosterone to maintain dendritic morphology of spinal motoneurons. In addition, testosterone regulates BDNF’s receptor (trkB) in motoneurons innervating the quadriceps muscles as well as in motoneurons of the highly androgen-sensitive spinal nucleus of the bulbocavernosus (SNB). Given these interactive effects, we examined whether androgen might also regulate BDNF in quadriceps and SNB motoneurons and their corresponding target musculature. In both motoneuron populations, castration of males reduced BDNF immunolabeling, and this effect was prevented with testosterone replacement. ELISA for BDNF in the target musculature of quadriceps (vastus lateralis, VL) and SNB (bulbocavernosus, BC) motoneurons revealed that BDNF in the VL and BC muscles was also regulated by androgen. However, although castration significantly decreased BDNF concentration in the VL muscle, BDNF concentration in the BC muscle was significantly increased in castrates. Treatment of castrated males with testosterone maintained BDNF levels at those of intact males in both sets of muscles. Together, these results demonstrate that androgens regulate BDNF in both a sexually dimorphic, highly androgen-sensitive neuromuscular system as well as a more typical somatic neuromuscular system. Furthermore, in addition to the regulation of trkB, these studies provide another possible mechanism for the interactive effects of testosterone and BDNF on motoneuron morphology. More importantly, by examining both the motoneurons and the muscles they innervate, these results demonstrate that within a neural system, BDNF levels in different components are differentially affected by androgen manipulation.

scholarly journals Impact of Silicon Foliar in Some of Antioxidant Enzymes and Oil Yield in Safflower Cultivars Exposed to Drought Stress

2021 ◽  
Vol 36 (1) ◽  
pp. 142-152
Author(s):  
Mehdi Sadeghi ◽  
Foroud Bazrafshan ◽  
Mahdi Zare ◽  
Omid Alizadeh ◽  
Bahram Amiri
Keyword(s):  
Drought Stress ◽  
Seed Yield ◽  
Oil Content ◽  
Interactive Effects ◽  
Oil Yield ◽  
Mineral Nutrient ◽  
Fars Province ◽  
Irrigation Level ◽  
Malondialdehyde Content ◽  
And Function

Drought stress is considered as a main restriction to have the best potential crops performance in arid and semi-arid regions in the world. Hence, some mechanistic strategies are required to manage drought stress detrimental influences. Silicon as an essential mineral nutrient, plays an important role in physiology, metabolism, and function of crops exposed to drought stress. This study was carried out to evaluate the influences of various irrigation regimes and silicon foliar on three safflower cultivars to find the optimal irrigation level and silicon fertilizer. Three levels of irrigation (0, 2 and 4 times irrigation during growth) were main plots and sub plots were three silicon foliar levels (0, 1 and 2 mM) and three safflower cultivars (Goldasht, Padideh and Golmehr). This experiment was performed in Firouzabad city, Fars Province, Iran with latitude 28°51' N and longitude 52°36' E, during 2018 and 2019. Malondialdehyde content (MDA), polyphenol oxidase (PPO), superoxide dismutase (SOD) and ascorbate peroxidase (APX), oil yield, oil content and seed yield were measured on these cultivars. Interactive effects of irrigation, silicon and cultivars were significant (p<0.01) for MDA, APX, oil yield and oil content. Drought stress in the all safflower cultivars caused a decline in seed yield, oil content and oil yield. On the other hands, silicon was mediated to decrease effect of drought stress and increased amount of seed yield, oil content, oil yield, PPO and SOD. The highest seed and oil yield were observed in Goldasht cultivar under full irrigation and 2mM silicon. Thus, it can be suggested that 1 mM of silicon foliar may ameliorate the performance of safflower exposed to drought stress.

Factors Maintaining and Regulating Grassland Structure and Function

2018 ◽  
Author(s):  
Brian J. Wilsey
Keyword(s):  
Vegetative Reproduction ◽  
Fuel Load ◽  
Large Mammals ◽  
Grassland Community ◽  
Grassland Species ◽  
Crop Fields ◽  
Plant Adaptations ◽  
Native Grasslands ◽  
Grassland Plants ◽  
And Function

Intrinsic disturbances are processes that have occurred on an evolutionary time scale, and include fire, wind-damage, digging or burrowing by fossorial mammals, defoliation, and trampling by native large mammals. Grassland species evolved with intrinsic disturbances, and they can be important in maintaining grassland community structure and functioning. Adaptations to fire include short herbaceous stature, high allocation belowground, ability to resprout, and smoke-induced seed germination. Fire interacts with grazing because grazing reduces litter (fuel) load, and fires affect forage quality. Plants can tolerate some level of herbivory in most grasslands. Adaptations that enable grassland plants to resist grazing are similar to plant adaptations to fire. Drought can affect grasslands at a variety of time scales. Vegetative reproduction can allow rapid recolonization after droughts have ended. Plowing is the most common disturbance affecting grasslands, and it has been used to transform native grasslands into crop fields and simplified pasture.

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