Detrimental or beneficial? Untangling the literature on developmental stress studies in birds

2021 ◽  
Vol 224 (19) ◽  
Author(s):  
Haruka Wada ◽  
Victoria Coutts
Keyword(s):  
Developmental Plasticity ◽  
Published Data ◽  
Developmental Stress ◽  
Physiological Functions ◽  
Thrifty Phenotype ◽  
Physiological Variables ◽  
Stress Studies ◽  
Organ Systems ◽  
And Performance ◽  
The Individual

ABSTRACT Developing animals display a tremendous ability to change the course of their developmental path in response to the environment they experience, a concept referred to as developmental plasticity. This change in behavior, physiology or cellular processes is primarily thought to allow animals to better accommodate themselves to the surrounding environment. However, existing data on developmental stress and whether it brings about beneficial or detrimental outcomes show conflicting results. There are several well-referred hypotheses related to developmental stress in the current literature, such as the environmental matching, silver spoon and thrifty phenotype hypotheses. These hypotheses speculate that the early-life environment defines the capacity of the physiological functions and behavioral tendencies and that this change is permanent and impacts the fitness of the individual. These hypotheses also postulate there is a trade-off among organ systems and physiological functions when resources are insufficient. Published data on avian taxa show that some effects of developmental nutritional and thermal stressors are long lasting, such as the effects on body mass and birdsong. Although hypotheses on developmental stress are based on fitness components, data on reproduction and survival are scarce, making it difficult to determine which hypothesis these data support. Furthermore, most physiological and performance measures are collected only once; thus, the physiological mechanisms remain undertested. Here, we offer potential avenues of research to identify reasons behind the contrasting results in developmental stress research and possible ways to determine whether developmental programming due to stressors is beneficial or detrimental, including quantifying reproduction and survival in multiple environments, measuring temporal changes in physiological variables and testing for stress resistance later in life.

scholarly journals Heat Pump Bridge Analysis Using the Modified Energy Transfer Diagram

Energies ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 137
Author(s):  
Florian Schlosser ◽  
Heinrich Wiebe ◽  
Timothy G. Walmsley ◽  
Martin J. Atkins ◽  
Michael R. W. Walmsley ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Heat Pump ◽  
Heat Recovery ◽  
Heat Pumps ◽  
Coefficient Of Performance ◽  
Combined Application ◽  
Recovery Potential ◽  
Composite Curve ◽  
And Performance ◽  
The Individual

Heat pumps are the key technology to decarbonise thermal processes by upgrading industrial surplus heat using renewable electricity. Existing insight-based integration methods refer to the idealised Grand Composite Curve requiring the full exploitation of heat recovery potential but leave the question of how to deal with technical or economic limitations unanswered. In this work, a novel Heat Pump Bridge Analysis (HPBA) is introduced for practically targeting technical and economic heat pump potential by applying Coefficient of Performance curves into the Modified Energy Transfer Diagram (METD). Removing cross-Pinch violations and operating heat exchangers at minimum approach temperatures by combined application of Bridge Analysis increases the heat recovery rate and reduce the temperature lift to be pumped at the same time. The insight-based METD allows the individual matching of heat surpluses and deficits of individual streams with the capabilities and performance of different market-available heat pump concepts. For an illustrative example, the presented modifications based on HPBA increase the economically viable share of the technical heat pump potential from 61% to 79%.

Neuroblastoma—When are Urinary Catecholamines and Their Metabolites ‘Normal’?

1988 ◽  
Vol 25 (6) ◽  
pp. 620-626 ◽  
Author(s):  
D J Worthington ◽  
E M Hammond ◽  
B B Eldeeb ◽  
A Green ◽  
G M Addison ◽  
...  
Keyword(s):  
Urinary Excretion ◽  
The Other ◽  
Published Data ◽  
Single Test ◽  
Creatinine Concentration ◽  
Urinary Catecholamines ◽  
Clinical Sensitivity ◽  
Reference Limit ◽  
Upper Reference Limit ◽  
The Individual

The overproduction of catecholamines and their metabolites is a well recognised feature of neuroblastoma. Published data are scarce for their urinary excretion in children with neuroblastoma and in ill children in whom this diagnosis may be considered. We have determined a graphical upper reference limit for total catecholamines, total metadrenalines and HMMA in urine, expressed as a ratio to the creatinine concentration, for a group of 174 children with neuroblastoma and 704 hospitalised children with other disorders. This graph has been determined by examining the overlap region between the results for the two groups of children and avoids the irregularities caused by statistical outliers. The sensitivity and specificity of the individual tests indicate that total catecholamines is marginally the best single test to perform when trying to diagnose neuroblastoma, with the best clinical sensitivity being achieved by examining both total catecholamines and HMMA. Only two of the 174 children with neuroblastoma would not have been detected using these two tests. Total metadrenalines did not appear to add any further information and could be dropped from the repertoire in favour of the other two measurements.

Surgical Drilling: Design and Performance of an Improved Drill

1982 ◽  
Vol 104 (3) ◽  
pp. 245-252 ◽  
Author(s):  
S. Saha ◽  
S. Pal ◽  
J. A. Albright
Keyword(s):  
Compact Bone ◽  
Helix Angle ◽  
Rake Angle ◽  
Peak Temperature ◽  
Published Data ◽  
Drill Bit ◽  
Effective Removal ◽  
Split Point ◽  
And Performance ◽  
Twist Drills

The majority of twist drills used in orthopaedics are very similar to chisel pointed metal drilling bits. Modifications usually observed are reduction of the point angle to 90 deg and sometimes grinding of the entire cutting lip at 0 deg rake angle, which appeared to have been made arbitrarily without any advantage. We have attempted to design a surgical drill bit with the objective of minimization of the drilling thrust and temperature and effective removal of bone chips. Our results showed that the presence of the chisel edge was mainly responsible for increasing the thrust force and the temperature developed. The effects of a constant feed rate and thrust on the peak temperature were also examined. The combined effect of the helix and the point angles on the rake angle which in turn determines the cutting efficiency was analyzed for various types of surgical bits. Based on our results and previously published data from the literature an optimized drill bit was designed with a split point, a point angle of 118 deg, a parabolic flute, and a helix angle of 36 deg and its performance was compared with other existing surgical drill bits. For drilling in compact bone, the new design decreased the thrust load by 45 percent and the peak temperature rise by 41 percent. Simlar improvements were also recorded for drilling bone cement. The time of drilling a bone cortex was also significantly reduced and “walking” on the curved bone surface was eliminated and dimensional tolerance on hole sizes was improved. The new design is likely to reduce the time of surgery and also minimize the tissue damage.

scholarly journals Rotor Interaction Noise in Counter-Rotating Propfan Propulsion Systems

2011 ◽  
Vol 134 (1) ◽  
Author(s):  
Andreas Peters ◽  
Zoltán S. Spakovszky
Keyword(s):  
Polar Angle ◽  
Secondary Flows ◽  
Tip Vortex ◽  
System Level ◽  
Analysis Tool ◽  
Acoustic Analogy ◽  
Wake Interaction ◽  
Open Rotor ◽  
And Performance ◽  
The Individual

Due to their inherent noise challenge and potential for significant reductions in fuel burn, counter-rotating propfans (CRPs) are currently being investigated as potential alternatives to high-bypass turbofan engines. This paper introduces an integrated noise and performance assessment methodology for advanced propfan powered aircraft configurations. The approach is based on first principles and combines a coupled aircraft and propulsion system mission and performance analysis tool with 3D unsteady, full-wheel CRP computational fluid dynamics computations and aeroacoustic simulations. Special emphasis is put on computing CRP noise due to interaction tones. The method is capable of dealing with parametric studies and exploring noise reduction technologies. An aircraft performance, weight and balance, and mission analysis was first conducted on a candidate CRP powered aircraft configuration. Guided by data available in the literature, a detailed aerodynamic design of a pusher CRP was carried out. Full-wheel unsteady 3D Reynolds-averaged Navier-Stokes (RANS) simulations were then used to determine the time varying blade surface pressures and unsteady flow features necessary to define the acoustic source terms. A frequency domain approach based on Goldstein’s formulation of the acoustic analogy for moving media and Hanson’s single rotor noise method was extended to counter-rotating configurations. The far field noise predictions were compared to measured data of a similar CRP configuration and demonstrated good agreement between the computed and measured interaction tones. The underlying noise mechanisms have previously been described in literature but, to the authors’ knowledge, this is the first time that the individual contributions of front-rotor wake interaction, aft-rotor upstream influence, hub-endwall secondary flows, and front-rotor tip-vortices to interaction tone noise are dissected and quantified. Based on this investigation, the CRP was redesigned for reduced noise incorporating a clipped rear-rotor and increased rotor-rotor spacing to reduce upstream influence, tip-vortex, and wake interaction effects. Maintaining the thrust and propulsive efficiency at takeoff conditions, the noise was calculated for both designs. At the interaction tone frequencies, the redesigned CRP demonstrated an average reduction of 7.25 dB in mean sound pressure level computed over the forward and aft polar angle arcs. On the engine/aircraft system level, the redesigned CRP demonstrated a reduction of 9.2 dB in effective perceived noise (EPNdB) and 8.6 EPNdB at the Federal Aviation Regulations (FAR) 36 flyover and sideline observer locations, respectively. The results suggest that advanced open rotor designs can possibly meet Stage 4 noise requirements.

Heart Rate and Performance in Manual Missile Guidance

1971 ◽  
Vol 32 (2) ◽  
pp. 352-354
Author(s):  
Bengt Bergstroem ◽  
Peter Arnberg
Keyword(s):  
Heart Rate ◽  
Performance Data ◽  
Tracking Performance ◽  
Missile Guidance ◽  
Heart Rates ◽  
Laboratory Conditions ◽  
Stress Studies ◽  
And Performance

Earlier stress studies under laboratory conditions show that heart rates from 100 to 110 bpm are associated with significant decrements in missile-tracking performance. Data from real missile tracking by 8 operators with no stress deliberately induced indicate, however, that performance is unaffected up to 135 bpm, and only moderately affected in the 135- to 170-bpm region. The disagreement between the two sets of results highlights the difficulties in generalizing from stress experiments.

Time for caring? Elderly care employees’ occupational activities in the cross draft between their work priorities, ‘must-do’s’ and meaningfulness

2017 ◽  
Vol 20 (1-2) ◽  
pp. 8-16 ◽  
Author(s):  
Emma Nilsson ◽  
Kerstin Nilsson
Keyword(s):  
Focus Group ◽  
Care Coordination ◽  
Work Performance ◽  
Elderly Care ◽  
The Elderly ◽  
Focus Group Interviews ◽  
Care Giving ◽  
Group Interviews ◽  
And Performance ◽  
The Individual

An increasing number of older people in the population will bring new challenges for the society and care coordination. One of the most important questions in care coordination is the employees’ work performance. The overall aim of this study was to examine care employees’ experience of factors that rule how they allocate their time and tasks in the care work. The study was qualitative and consists of focus group interviews with 36 employees in elderly care in five Swedish municipalities. Much of the work that care employees perform is controlled by others in the municipality organised health care. The employees had a limited possibility to decide what should be given priority in their work. However, the employees who participated in the focus group interviews did not want to prioritise tasks and duties they felt were faulty or in direct conflict with their own convictions. When employees experienced that the assistance assessments were correct and helpful to the individual elderly patient this contributed to the employees’ priority and performance of the task. The formal and informal control systems caused the employees’ priority to be mainly quantitative and visible work tasks, rather than more qualitative tasks and care giving to the elderly. In the intention to organise good care coordination that fit each elderly patients’ need it is important that those who work closest to the patient to a greater extent are given the opportunity to make their voice heard in decisions of care planning and assistance assessments.

scholarly journals Sports Foods and Dietary Supplements for Optimal Function and Performance Enhancement in Track-and-Field Athletes

2019 ◽  
Vol 29 (2) ◽  
pp. 198-209 ◽  
Author(s):  
Peter Peeling ◽  
Linda M. Castell ◽  
Wim Derave ◽  
Olivier de Hon ◽  
Louise M. Burke
Keyword(s):  
Performance Enhancement ◽  
Evidence Base ◽  
Track And Field ◽  
Supplement Use ◽  
Optimal Function ◽  
Repeated Use ◽  
And Performance ◽  
The Individual ◽  
Health Function ◽  
Specific Scenario

Athletes are exposed to numerous nutritional products, attractively marketed with claims of optimizing health, function, and performance. However, there is limited evidence to support many of these claims, and the efficacy and safety of many products is questionable. The variety of nutritional aids considered for use by track-and-field athletes includes sports foods, performance supplements, and therapeutic nutritional aids. Support for sports foods and five evidence-based performance supplements (caffeine, creatine, nitrate/beetroot juice, β-alanine, and bicarbonate) varies according to the event, the specific scenario of use, and the individual athlete’s goals and responsiveness. Specific challenges include developing protocols to manage repeated use of performance supplements in multievent or heat-final competitions or the interaction between several products which are used concurrently. Potential disadvantages of supplement use include expense, false expectancy, and the risk of ingesting banned substances sometimes present as contaminants. However, a pragmatic approach to the decision-making process for supplement use is recommended. The authors conclude that it is pertinent for sports foods and nutritional supplements to be considered only where a strong evidence base supports their use as safe, legal, and effective and that such supplements are trialed thoroughly by the individual before committing to use in a competition setting.

Molecular weight determines the frequency of delayed type hypersensitivity reactions to heparin and synthetic oligosaccharides

2005 ◽  
Vol 94 (12) ◽  
pp. 1265-1269 ◽  
Author(s):  
Susanne Alban ◽  
Roland Kaufmann ◽  
Edelgard Lindhoff-Last ◽  
Wolf-Henning Boehncke ◽  
Ralf J. Ludwig ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Heparin Therapy ◽  
Delayed Type Hypersensitivity ◽  
Published Data ◽  
Low Molecular Weight ◽  
Hypersensitivity Reactions ◽  
Type Iv ◽  
Total Data ◽  
The Individual

SummaryEczematous lesions, resulting from type IV sensitizations are well-known and relatively frequent cutaneous adverse effects of s.c. heparin therapy. If anticoagulation is further required intravenous heparin, heparinoids or lepirudin may be used as a substitute. However, these alternatives are not optimal in terms of practicability and/or safety-profiles. As molecular weight of different heparin preparations has repetitively been implied to determine the frequency of sensitization, we hypothesized, that due to its low molecular weight the pentasaccharide fondaparinux may provide a practicable and safe anticoagulant therapy in patients with delayed type hypersensitivity reactions (DTH) to heparin and other oligosaccharides. To test this concept, patients referred for diagnosis of cutaneous reactions after s.c. anticoagulant treatment underwent a series of in vivo skin allergyand challenge-tests with unfractionated heparin, a series of low molecular weight heparins (nadroparin, dalteparin, tinzaparin, enoxaparin and certoparin), the heparinoid danaparoid and the synthetic pentasaccharide fondaparinux. In total, data from twelve patients was evaluated. In accordance with previously published data, we report a high crossreactivity among heparins and heparinoids. In contrast – and in support of our initial hypothesis – sensitization towards the synthetic pentasaccharide fondaparinux was rarely observed. Plotting the cumulative incidence against the determined molecular weight of the individual anticoagulant preparations, shows that molecular weight generally is a key determinant of sensitization towards heparins and other oligosaccharides (r2=0.842, p=0.009). Hence, fondaparinux may be used as a therapeutic alternative in patients with cutaneous DTH relations towards heparin and other polysaccharides.

scholarly journals Effects of Lean Tools in Achieving Lean Warehousing

2016 ◽  
Vol 54 (4) ◽  
pp. 517-534 ◽  
Author(s):  
Aleksandra Anđelković ◽  
Marija Radosavljević ◽  
Danijela Stošić
Keyword(s):  
Lean Principles ◽  
Before And After ◽  
Lean Tools ◽  
And Performance ◽  
The Individual ◽  
Warehouse Operations

Abstract The acceptance of lean philosophy in the company means not only respecting the lean principles in the manufacturing but in all the processes that are performed inside the company. All processes in the company that are a potential places for making losses and waste and thus require the application of lean principles. Among others, warehouse and warehouse operations, as a centre of costs and waste, must be supported through the implementation of lean philosophy in the company by respecting lean principles. The implementation of lean principles in the warehouse is a certain step of improvement warehouse process and performance, but also of the whole company. In that sense, the paper presents the analysis of the warehousing process and its performances before and after implementation of the lean tools in a selected Serbian company as a practical example. In addition, research shows which parts of warehousing need to be improved, in analysed company, as well as correlation between the individual parts of warehousing, according to employees' opinion from next sectors: purchasing, production and logistics.

scholarly journals Impact of a training program on the performance of graduating Canadian residents on a national urology exam: Results of the last 20 years

2018 ◽  
Vol 13 (2) ◽  
Author(s):  
Naji J. Touma ◽  
Darren T. Beiko ◽  
Andrew E. MacNeily ◽  
Michael J. Leveridge
Keyword(s):  
Training Program ◽  
Training Programs ◽  
Certification Exams ◽  
Certification Exam ◽  
Individual Program ◽  
The Mean ◽  
And Performance ◽  
The Individual ◽  
The Impact ◽  
Oral Component

Introduction: Many factors impact the performance of graduating residents on certification exams. It is thought that most factors are related to the individual candidate’s ability, motivation, and work ethic. Less understood, however, is whether a training program has any impact on the preparation and performance of its graduates on certification exams. We present 20 years of results of a national preparatory exam that all graduating residents complete about three months before the Royal College of Physicians and Surgeons of Canada (RCPSC) qualifying urology exam. This exam, known colloquially as QUEST, aims to simulate the RCPSC exam with written and oral components. We aimed to analyze the impact of a training program on the performance of its residents. Methods: A retrospective review of exam results from 1997–2016 was conducted. During that time, 495 candidates from all 12 Canadian urology training programs undertook the exam. The performance of graduating residents from each individual program was grouped together for any given year. The different programs were anonymized, as the aim of this study is to assess the impact of a training program and not to rate the different programs. Statistical analysis using one-way ANOVA was conducted. Results: All training programs fall within one standard deviation of the mean for the written component, the oral component, and the overall score. The residents of four training programs had statistically better scores than the overall mean of the written component. The residents of three out of these four training programs also had statistically better scores than the overall mean of the oral component and the overall results of the exam. Conclusions: Most Canadian training programs prepare their residents adequately for this simulated certification exam in urology. However, there are some training programs that consistently prepare graduating residents to outperform their peers.

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