Effects of formalin preservation on invertebrate stable isotope values over decadal time scales

2012 ◽  
Vol 90 (11) ◽  
pp. 1320-1327 ◽  
Author(s):  
Michael D. Rennie ◽  
Ted Ozersky ◽  
David O. Evans
Keyword(s):  
Stable Isotope ◽  
Marine Invertebrate ◽  
Time Frame ◽  
Freshwater Invertebrates ◽  
Significant Difference ◽  
Formalin Preservation ◽  
Ecosystem Changes ◽  
Short Time ◽  
Control Samples

Stable isotope values derived from chemically preserved organisms are a valuable resource for documenting long-term ecosystem changes. However, isotopic correction factors of preservation effects applied to samples stored for decades are frequently based on studies lasting only months, assuming that the effects of preservation stabilize within a short time frame. Very few studies test this critical assumption. We validated this assumption for formalin-preserved invertebrate tissues, finding no significant difference between mean isotopic δ13C and δ15N values of material stored 1–15 years across taxa. Preservation effects were evaluated for Amphipoda, Chironomidae, Dreissenidae, Ephemeroptera, Gastropoda, Isopoda, Sphaeridae, Oligochaeta, and Trichoptera. On average, freshwater benthos δ13C was lower by approximately 2‰ after formalin fixation, whereas δ15N values were not different from control samples. Fixation effects were similar among taxa, but were more pronounced in Gastropoda and Sphaeridae for δ13C and in Trichoptera for δ15N. We reviewed the literature to show that preserved freshwater zooplankton δ13C were slightly but significantly lower relative to control samples (–0.2‰) and higher in δ15N (+0.25‰). The mean decline among marine invertebrate δ13C was greater than for freshwater invertebrates after 1+ years of formalin preservation, but effects on δ15N were not different between marine and freshwater invertebrates.

scholarly journals Continuous Viral Escape and Selection by Autologous Neutralizing Antibodies in Drug-Naïve Human Immunodeficiency Virus Controllers

2008 ◽  
Vol 83 (2) ◽  
pp. 662-672 ◽  
Author(s):  
Madhumita Mahalanabis ◽  
Pushpa Jayaraman ◽  
Toshiyuki Miura ◽  
Florencia Pereyra ◽  
E. Michael Chester ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Neutralizing Antibodies ◽  
Time Frame ◽  
Continuous Selection ◽  
Viral Escape ◽  
Elite Controllers ◽  
Hiv Replication ◽  
Immunodeficiency Virus ◽  
Short Time

ABSTRACT We assessed differences in the character and specificity of autologous neutralizing antibodies (ANAbs) against individual viral variants of the quasispecies in a cohort of drug-naïve subjects with long-term controlled human immunodeficiency virus type 1 (HIV-1) infection and moderate levels of broad heterologous neutralizing antibodies (HNAb). Functional plasma virus showed continuous env evolution despite a short time frame and low levels of viral replication. Neutralization-sensitive variants dominated in subjects with intermittent viral blips, while neutralization-resistant variants predominated in elite controllers. By sequence analysis of this panel of autologous variants with various sensitivities to neutralization, we identified more than 30 residues in envelope proteins (Env) associated with resistance or sensitivity to ANAbs. The appearance of new sensitive variants is consistent with a model of continuous selection and turnover. Strong ANAb responses directed against autologous Env variants are present in long-term chronically infected individuals, suggesting a role for these responses in contributing to the durable control of HIV replication.

scholarly journals COVID-19 in Chile: The usefulness of simple epidemic models in practice

Medwave ◽  
2021 ◽  
Vol 21 (01) ◽  
pp. e8119-e8119
Author(s):  
Mauricio Canals ◽  
Cristóbal Cuadrado ◽  
Andrea Canals
Keyword(s):  
Gompertz Model ◽  
Time Frame ◽  
Type Model ◽  
Local Behavior ◽  
Discrete Equations ◽  
The Monte Carlo Method ◽  
Great Utility ◽  
Short And Long Term ◽  
Short Time

Objectives The purpose of this article is to describe and develop the predictive value of three models during the COVID-19 epidemic in Chile, providing knowledge for decision-making in health. Methods We developed three models during the epidemic: a discrete model to predict the maximum burden on the health system in a short time frame—a basic SEIR (susceptible-exposed-infected-removed) model with discrete equations; a stochastic SEIR model with the Monte Carlo method; and a Gompertz-type model for metropolitan city of Santiago. Results The maximum potential burden model has been useful throughout the monitoring of the epidemic, providing an upper bound for the number of cases, intensive care unit occupancy, and deaths. Deterministic and stochastic SEIR models were very useful in predicting the rise of cases and the peak and onset of case decline; however, they lost utility in the current situation due to the asynchronous recruitment of cases in the regions and the persistence of a strong endemic. The Gompertz model had a better fit in the decline since it best captures the epidemic curve’s asymmetry in Santiago. Conclusions The models have shown great utility in monitoring the epidemic in Chile, with different objectives in different epidemic stages. They have complemented empirical indicators such as reported cases, fatality, deaths, and others, making it possible to predict situations of interest and visualization of the short and long-term local behavior of this pandemic.

The red packet interaction and brand attitude in the brand communities on WeChat

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Guowei Zhu ◽  
Yaru Liu ◽  
Li Zhou
Keyword(s):  
Social Networking Sites ◽  
Time Frame ◽  
Negative Influence ◽  
Brand Attitude ◽  
Short Term ◽  
Content Type ◽  
Brand Communities ◽  
Significant Difference ◽  
Community Pressure

Purpose Monetary incentives have been widely adopted by brands to promote consumer engagement in their brand communities on social networking sites. This paper aims to explore how the interactions triggered by an emerging monetary incentive, red packets, affect consumers’ brand attitude in the context of WeChat brand groups (WCBGs). Design/methodology/approach According to whether brands ask for commercial returns from consumers, two types of interactions were identified, namely, exchange red packet interaction (ERPI) and communal red packet interaction (CRPI). The corresponding influences on brand attitude were examined in three experiments. Findings Compared to CRPIs, ERPIs elicit greater normative community pressure, inducing a less favorable brand attitude. Moreover, this impact is moderated by the time frame of brand communities. In the long-term WCBGs, a significant difference exists between ERPIs and CRPIs, while such difference attenuates or even disappears in short-term WCBGs. Practical implications When using red packets as an engagement strategy, brand managers should be alert to their potential negative influence. Specifically, in short-term brand communities, ERPIs enable managers to acquire commercial returns without hurting brand attitude. In long-term brand communities, managers are advised to implement CRPIs to foster a positive brand attitude. Originality/value This study investigates red packet interactions in brand communities, which have been widespread but unexplored. The results expand the literature by addressing the undermining effect of ERPI and the moderating effect of the time frame.

Damage Assessment and Residual Service Life Estimation of Cracked Timber Beams

2013 ◽  
Vol 778 ◽  
pp. 402-409 ◽  
Author(s):  
Jan Willem G. van de Kuilen ◽  
Wolfgang Gard
Keyword(s):  
Service Life ◽  
Time Frame ◽  
Practical Case ◽  
Residual Service Life ◽  
Time To Failure ◽  
Service Life Estimation ◽  
Short Time ◽  
Residual Service ◽  
Timber Beams

Service life modelling of cracked timber beams can be performed using modified damage accumulation models that describe the combined effect or long term loads (mechanical) and biological of physical wood degradation. The combined model allows for the estimation of residual service life and an analysis of crack development. The model can also be used to analyse safety factors that may need to be applied. Also, a sensitivity analysis can be performed for future risks. It is shown that the failure risk is very sensitive to the level of the applied loads, similar to time to failure analysis of non-degraded timber. Failure in timber structures occurs within a very short time frame. A practical case of cracked glulam beams is included in the paper.

scholarly journals A Multicenter Intervention to Improve Ambulatory Care Handoffs at the End of Residency

2014 ◽  
Vol 6 (1) ◽  
pp. 112-116 ◽  
Author(s):  
Michael J. Donnelly ◽  
Janelle M. Clauser ◽  
Rochelle E. Tractenberg
Keyword(s):  
Internal Medicine ◽  
Health Care ◽  
Health Care System ◽  
Transition Period ◽  
Time Frame ◽  
Free Text ◽  
Significant Difference ◽  
Short Time ◽  
Care System

Abstract Background Graduating residents transition their continuity clinic patients to junior colleagues every year, creating a vulnerable transition period for about 1 million patients nationally. Objective We examined a standardized, electronic template for handing off high-risk ambulatory patients by outgoing residents from 7 residencies within a large health care system, and compared handoff quantity and provider satisfaction for handoffs with and without that template. Methods Residents graduating in 2011 from 5 internal medicine, 1 family medicine, and 1 internal medicine-pediatrics residency programs in 1 health care system were randomized to a new electronic handoff process with a standardized intervention template or a free-text handoff. Expert reviewers independently evaluated all handoff notes, and providers were surveyed after follow-up appointments regarding use, helpfulness, and overall satisfaction with the handoffs. Results Fifty-two of 79 residents (66%) participated, performing 278 handoffs. Eighty-four patients (30%, 17 of 57) failed to follow up within the study period. For patients who followed up, providers read 61% (101 of 165) of the handoffs at the time of the visit. No significant difference existed between groups in the satisfaction of the follow up provider or the quality measure of the handoffs in our process. Expert agreement on which features make the handoff “helpful” was fair (κ  =  0.34). Conclusions A standardized template did not improve handoff quantity or satisfaction compared with a free-text handoff. Practical handoff programs can be instituted into diverse residencies within a short time frame, with most residents taking part in creating the handoff formats.

scholarly journals EP.TU.356Can day case elective operating lists provide efficient training opportunities for general surgical trainees?

2021 ◽  
Vol 108 (Supplement_7) ◽  
Author(s):  
Rachael Coulson ◽  
Catherine Gilmore ◽  
Catherine Sheridan ◽  
Anna Murray ◽  
Scott McCain ◽  
...  
Keyword(s):  
Time Frame ◽  
Day Surgery ◽  
Day Case ◽  
Surgical Trainees ◽  
Significant Difference ◽  
Centre Of Excellence ◽  
Hands On Learning ◽  
Short Time ◽  
The Impact ◽  
Training Opportunities

Abstract Introduction During the COVID-19 pandemic there has been a reduction in trainee hands-on learning opportunities due to curtailment of elective workload. Our study aims to assess the impact of non-consultant led operating on theatre list efficiency. Methods Prospective data collection over an eight week period of consecutive elective day case hernia lists at a newly established regional centre of excellence for day surgery. Specifically recording of key time points in surgical cases including time ready, knife to skin, last suture and exit theatre. This was achieved using the Theatre Management System (TMS). Results 46 patients underwent open unilateral elective inguinal hernia repair. 54% (N = 25) of cases were trainee led. Median trainee time was 53 minutes, vs 51 minutes for consultant led procedures; no significant difference (p > 0.05). Conclusion Day case elective hernia lists can be efficient training opportunities for general surgical trainees. Our results demonstrate that trainee-led operating in this setting have not resulted in significantly increased surgical time or operative theatre inefficiency. It is widely acknowledged there is benefit to training in performing the same technical skill within a short time frame.

scholarly journals Sexual function outcomes following fracture of the penis.

2013 ◽  
Vol 7 (7-8) ◽  
pp. 252 ◽  
Author(s):  
Gregory J Nason ◽  
Barry B McGuire ◽  
Stephen Liddy ◽  
Aisling Looney ◽  
Gerald M Lennon ◽  
...  
Keyword(s):  
Sexual Function ◽  
Time Frame ◽  
Long Term Outcomes ◽  
Patient Reported ◽  
Male Sexual Function ◽  
Grading Scale ◽  
Urological Emergency ◽  
Short Time

Introduction: Fracture of the penis is a rare urological emergency which occurs as a result of abrupt trauma to an erect penis. There is paucity of data regarding long-term sexual function or erectile potency following fracture of the penis. The aim of this study is to objectively assess the overall sexual function following fracture of the penis.Methods: A retrospective analysis of 21 penile fractures was performed. A voluntary telephone questionnaire was performed to assess long term outcomes using three validated questionnaires-the Erection Hardness Grading Scale, the International Index of Erectile Function (IIEF-5) and the Brief Male Sexual Function inventory (BMSFI).Results: The mean age was 33.1 years (range: 19-63). The median follow up was 46 months (range: 3-144). All fractures were a result of sexual misadventure and all were surgically repaired. There were two concomitant urethral injuries. Seventeen patients were contactable. Fourteen patients demonstrated no evidence of erectile dysfunction (ED) (IIEF-5>22), 1 patient reported symptoms of mild ED (IIEF-5, 17-21) and one patient reported mild to moderate ED (IIEF-5, 12-16). No patients reported insufficient erection for penetration (EHGS: 1 or 2). Regarding the overall BMSFI, 13 (83%) patients were mostly satisfied or very satisfied with their sex life within the previous month.Conclusion: In a small surgical series of men with penile fracture managed within a short time frame from presentation, we demonstrate erectile potency is maintained. Long-term overall sexual satisfaction is promising.

Implementation and Operation of a CCGT Power Plant for a Chemical Plant: How to Cover Special Steam Conditions

2006 ◽  
Author(s):  
Gabor Bercsi ◽  
Zsolt Czibere ◽  
Viktor Varga
Keyword(s):  
Power Plant ◽  
Electricity Market ◽  
Electricity Generation ◽  
Time Frame ◽  
First Year ◽  
Chemical Company ◽  
Start Up ◽  
Technical Features ◽  
Short Time

TVK, as one of the leader companies of chemical industry in Central-Europe, in 2000 decided to place their heat and electricity supply on new bases. The long term steam supply from Power Plant Tiszapalkonya seemed to be not secured due to restricted environmental regulation. TVK intended to extend its polyolefin production facility which has increased the steam demand. TVK decided to construct a boiler plant/power plant with the following requirements: • long-term, secure and economical steam supply meeting the entire steam demand of TVK supplied from a source other than its own, • an acceptable time frame for the implementation and the development of the project, • the lowest possible capital requirement (involvement of a professional investor), • in the case of electricity generation, it may only be carried out through cogeneration with heat, with the minimization of condensing electricity generation, with regard to the process of the opening of the electricity market. The power plant project has been realized through a project company established by TVK and North Hungarian Electricity Distribution Co. where the chemical company has 26%, the professional investor has 74% ownership. The construction of the power plant started at the beginning of 2002 and finished in 2004. The installed steam capacity of the project is 250 t/h the power output is 35 MW. The plant has been delivered by Siemens-Transelektro consortia based on turn-key EPC Contract. The plant consists of a Siemens SGT 600 (former GT10B) gas turbine with supplementary fired HRSG and a Siemens ST-6 steam turbine and three auxiliary boilers with 65 t/h steam capacity each. The paper to be presented shows the decision making process concerning the power plant investment. It describes the technical scheme of the project and outlines the special technical features of the steam supply arising from the unusual steam load of TVK especially during start-up, shut-down and forced outages of the olefin plants which requires high additional steam supply in short time. It shows the experiences of the first year of operation too, how the plant has been able to fulfill its design criteria.

Improvement Of Curvilinear Diagrams Of Concrete Deformation

2019 ◽  
pp. 99-104
Keyword(s):  
Reinforced Concrete ◽  
Peak Load ◽  
Experimental Studies ◽  
Concrete Structures ◽  
Deformation Model ◽  
Reinforced Concrete Structures ◽  
Significant Difference ◽  
Deformation Diagrams

Problems when calculating reinforced concrete structures based on the concrete deformation under compression diagram, which is presented both in Russian and foreign regulatory documents on the design of concrete and reinforced concrete structures are considered. The correctness of their compliance for all classes of concrete remains very approximate, especially a significant difference occurs when using Euronorm due to the different shape and sizes of the samples. At present, there are no methodical recommendations for determining the ultimate relative deformations of concrete under axial compression and the construction of curvilinear deformation diagrams, which leads to limited experimental data and, as a result, does not make it possible to enter more detailed ultimate strain values into domestic standards. The results of experimental studies to determine the ultimate relative deformations of concrete under compression for different classes of concrete, which allowed to make analytical dependences for the evaluation of the ultimate relative deformations and description of curvilinear deformation diagrams, are presented. The article discusses various options for using the deformation model to assess the stress-strain state of the structure, it is concluded that it is necessary to use not only the finite values of the ultimate deformations, but also their intermediate values. This requires reliable diagrams "s–e” for all classes of concrete. The difficulties of measuring deformations in concrete subjected to peak load, corresponding to the prismatic strength, as well as main cracks that appeared under conditions of long-term step loading are highlighted. Variants of more accurate measurements are proposed. Development and implementation of the new standard GOST "Concretes. Methods for determination of complete diagrams" on the basis of the developed method for obtaining complete diagrams of concrete deformation under compression for the evaluation of ultimate deformability of concrete under compression are necessary.

Markets, Technological Change and Economic Growth (The Quaid-i-Azam Lecture)

1994 ◽  
Vol 33 (4I) ◽  
pp. 327-356 ◽  
Author(s):  
Richard G. Lipsey
Keyword(s):  
United States ◽  
Economic Growth ◽  
Developing Countries ◽  
Common Ground ◽  
The United States ◽  
Industrial Countries ◽  
Canadian Institute ◽  
Primary Focus ◽  
Short Time

I am honoured to be invited to give this lecture before so distinguished an audience of development economists. For the last 21/2 years I have been director of a project financed by the Canadian Institute for Advanced Research and composed of a group of scholars from Canada, the United States, and Israel.I Our brief is to study the determinants of long term economic growth. Although our primary focus is on advanced industrial countries such as my own, some of us have come to the conclusion that there is more common ground between developed and developing countries than we might have first thought. I am, however, no expert on development economics so I must let you decide how much of what I say is applicable to economies such as your own. Today, I will discuss some of the grand themes that have arisen in my studies with our group. In the short time available, I can only allude to how these themes are rooted in our more detailed studies. In doing this, I must hasten to add that I speak for myself alone; our group has no corporate view other than the sum of our individual, and very individualistic, views.

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