scholarly journals Corticosterone, Adrenal, and the Pituitary-Gonadal Axis in Neonatal Rats: Effect of Maternal Separation and Hypoxia

Endocrinology ◽  
2020 ◽  
Vol 161 (7) ◽  
Author(s):  
Ashley L Gehrand ◽  
Jonathan Phillips ◽  
Kevin Malott ◽  
Hershel Raff
Keyword(s):  
Maternal Separation ◽  
Plasma Corticosterone ◽  
Plasma Testosterone ◽  
Postnatal Life ◽  
Sexually Dimorphic ◽  
Long Term Effects ◽  
Estrogen Production ◽  
Corticosterone Response ◽  
Short And Long Term

Abstract Hypoxia, a common stressor in prematurity, leads to sexually dimorphic, short- and long-term effects on the adult hypothalamic-pituitary-adrenal (HPA) and hypothalamic-pituitary-gonadal (HPG) axes. We hypothesized that these effects are due to stress-induced increases in testosterone during early postnatal life. We evaluated this phenomenon by systematically assessing the short-term effects of normoxic or hypoxic separation on male and female pups at birth, postnatal hours (H) 2, 4, and 8, and postnatal days (PD) 2 to 7. Our findings were (a) hypoxic separation led to a large increase in plasma corticosterone from 4H-PD4, (b) neither normoxic nor hypoxic separation affected critical adrenal steroidogenic pathway genes; however, a significant decrease in baseline Cyp11a1, Mc2r, Mrap, and Star adrenal expression during the first week of neonatal life confirmed the start of the adrenal stress hyporesponsive period, (c) a luteinizing hormone/follicle-stimulating hormone–independent increase in plasma testosterone occurred in normoxic and hypoxic separated male pups at birth, (d) testicular Cyp11a1, Lhcgr, and Star expression was high at birth and decreased thereafter suggesting a hyporesponsive period in the testes, and (e) elevated estrogen in the early neonatal period occurred independently of gonadotropin stimulation. We conclude that a large corticosterone response to hypoxia during the first 5 days of life occurs as an adaptation to neonatal stress, that the testosterone surge during the first hours after birth occurs independently of gonadotropins but is associated with upregulation of the steroidogenic pathway genes in the testes, and that high postnatal estrogen production also occurs independently of gonadotropins.

Saskatchewan Highways and Transportation Reduced Tire Pressure Initiative

1997 ◽  
Vol 1589 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Thomas L. Davies ◽  
Tami F. Wall ◽  
Allan Carpentier
Keyword(s):  
High Speed ◽  
Membrane Surface ◽  
Vehicle Stability ◽  
Road Maintenance ◽  
Long Term Effects ◽  
Tire Pressure ◽  
Reduced Pressure ◽  
Maintenance Costs ◽  
Short And Long Term

After examination of the research carried out by other agencies, Saskatchewan Highways and Transportation (SHT) embarked on an initiative to adapt low tire pressure technologies to the province's needs and environment. The focus of the initiative was to explore several technical questions from SHT's perspective: (a) Can low tire pressures be used to increase truck weights from secondary to primary without increasing road maintenance costs on thin membrane surface roads? (b) What are the short- and long-term effects of tire heating under high-speed/high-deflection constant reduced pressure (CRP) operations in a Saskatchewan environment? (c) What effects do lower tire pressures have on vehicle stability at highway speeds? To date, significant opportunities have been noted on local hauls (less than 30 min loaded at highway speeds) for CRP operation and long primary highway hauls that begin or end in relatively short secondary highway sections that limit vehicle weight allowed for the whole trip for central tire inflation technology. The background and environment for the initiative and the investigations and demonstrations envisioned and undertaken are briefly outlined.

The Neurobiology of Pain

2019 ◽  
pp. 387-414
Author(s):  
Maria Fitzgerald ◽  
Michael W. Salter
Keyword(s):  
Early Life ◽  
Pain Perception ◽  
Long Term Effects ◽  
Male And Female ◽  
Functional Changes ◽  
Pain Pathways ◽  
Developmental Age ◽  
Short And Long Term ◽  
Age And Sex

The influence of development and sex on pain perception has long been recognized but only recently has it become clear that this is due to specific differences in underlying pain neurobiology. This chapter summarizes the evidence for mechanistic differences in male and female pain biology and for functional changes in pain pathways through infancy, adolescence, and adulthood. It describes how both developmental age and sex determine peripheral nociception, spinal and brainstem processing, brain networks, and neuroimmune pathways in pain. Finally, the chapter discusses emerging evidence for interactions between sex and development and the importance of sex in the short- and long-term effects of early life pain.

Management of competition among sellers and its performance implications for business-to-business electronic platforms

2015 ◽  
Vol 6 (2) ◽  
pp. 199-222 ◽  
Author(s):  
Xiaoling Li ◽  
Xingyao Ren ◽  
Xu Zheng
Keyword(s):  
Longitudinal Research ◽  
Time Windows ◽  
Customer Relationship ◽  
Effective Control ◽  
Marketing Tactics ◽  
Long Term Effects ◽  
Content Type ◽  
Short And Long Term ◽  
Term Performance

Purpose – This paper aimed to analyze the short- and long-term effects of the breadth and depth of seller competition on the performance of platform companies, and investigated the underlying mechanisms of customers’ two-sided marketing tactics on the structure of the competition between sellers. Design/methodology/approach – A longitudinal research design was adopted by gathering daily market objective data on e-commerce platforms for 250 days, and the dynamic evolution effects was analyzed by using a vector autoregression model which compared the differences between the short- and long-term effectiveness of different customer relationship management (CRM) strategies. Findings – The breadth of competition amongst sellers improves the performance of platforms, whilst the depth of competition among sellers has a positive effect on the short-term performance. However, it has a negative effect on the long-term performance of their platforms. In both the short and long terms, advertising tactics that attract new buyers contribute more to increases in the breadth of seller competition than those that attract existing buyers do. Subsidies for new sellers decrease the depth of seller competition more than those for old sellers. Research limitations/implications – Further research could be undertaken to investigate the validity of marketing tactics other than advertising tactics, and thus expand the time windows of the available data. Practical implications – It is imperative for platform companies to implement effective control over seller competition to balance the interests of the sellers and of themselves. Originality/value – The dyadic paradigm of CRM research has been extended by considering the perspective of the electronic platform company, how the tactics of exploitation and exploration of two-sided customers impact upon seller competitive structures have been delved into and why new customers have a unique value to platform companies has been identified.

Communication Via Instant Messenger: Short- and Long-Term Effects

2005 ◽  
Vol 35 (3) ◽  
pp. 445-462 ◽  
Author(s):  
Melanie C. Green ◽  
Jessica Hilken ◽  
Hayley Friedman ◽  
Karly Grossman ◽  
Josephine Gasiewskj ◽  
...  
Keyword(s):  
Long Term Effects ◽  
Instant Messenger ◽  
Short And Long Term
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