Changes In Long-term Performance Research Articles

A Soil Moisture Profile Conceptual Framework to Identify Water Availability and Recovery in Green Stormwater Infrastructure

The recovery of soil void space through infiltration and evapotranspiration processes within green stormwater infrastructure (GSI) is key to continued hydrologic function. As such, soil void space recovery must be well understood to improve the design and modeling and to provide realistic expectations of GSI performance. A novel conceptual framework of soil moisture behavior was developed to define the soil moisture availability at pre-, during, and post-storm conditions. It uses soil moisture measurements and provides seven critical soil moisture points (A, B, C, D, E, F, F″) that describe the soil–water void space recovery after a storm passes through a GSI. The framework outputs a quantification of a GSI subsurface hydrology, including average soil moisture, the duration of saturation, soil moisture recession, desaturation time, infiltration rates, and evapotranspiration (ET) rates. The outputs the framework provide were compared to the values that were obtained through more traditional measurements of infiltration (through spot field infiltration testing), ET (through a variety of methods to quantify GSI ET), soil moisture measurements (through the soil water characteristics curve), and the duration of saturation/desaturation time (through a simulated runoff test), all which provided a strong justification to the framework. This conceptual framework has several applications, including providing an understanding of a system’s ability to hold water, the post-storm recovery process, GSI unit processes (ET and infiltration), important water contents that define the soil–water relationship (such as field capacity and saturation), and a way to quantify long-term changes in performance all through minimal monitoring with one or more soil moisture sensors. The application of this framework to GSI design promotes a deeper understanding of the subsurface hydrology and site-specific soil conditions, which is a key advancement in the understanding of long-term performance and informing GSI design and maintenance.

Prediction of water vapor permeation and desiccant saturation in vacuum insulation panels with a glass fiber core

The permeation of dry air in vacuum insulation panels (VIPs) with a glass fiber core has been often prevented using laminated films with metallized ethylene vinyl alcohol copolymer (EVOH) layers; meanwhile, desiccants are incorporated to control the increasing pressure due to the permeation of water vapor. Previously proposed models can predict the changes in long-term performance caused by dry-air permeation, but a method that accounts for water-vapor permeation and desiccant saturation has not been reported before. Predicting the long-term performance of VIPs when exposed to outdoor temperature and humidity is essential for using it as a building insulation material. In this study, we investigated the dependence of the water-vapor transmission rate (WVTR) of metallized EVOH film on temperature and relative humidity, and the effect of ambient water-vapor pressure on the WVTR of metallized EVOH film. To reduce the measurement time of WVTR, we developed a new measurement method using a small sensor device and confirmed that its accuracy is equivalent to that of the conventional method. We measured the water-vapor transmission coefficient of glass fiber core VIPs under various temperature and humidity conditions using this measurement method. For the same water-vapor pressure, the amount of transmission significantly depended on the temperature and humidity conditions. Therefore, the WVTR of metallized EVOH films should be more concerned with the effect of relative humidity than that of the water vapor pressure of the ambient air. Based on these results, a new model that accounts for desiccant saturation was proposed and validated based on the conventional model to predict the long-term performance under permeation of mixed gases. The new model accurately evaluated the long-term performance of VIPs with confirmed desiccant saturation, supporting the long-term performance of glass fiber core VIPs.

Does Motor Memory Reactivation through Practice and Post-Learning Sleep Modulate Consolidation?

Retrieving previously stored information makes memory traces labile again and can trigger restabilization in a strengthened or weakened form depending on the reactivation condition. Available evidence for long-term performance changes upon reactivation of motor memories and the effect of post-learning sleep on their consolidation remains scarce, and so does the data on the ways in which subsequent reactivation of motor memories interacts with sleep-related consolidation. Eighty young volunteers learned (Day 1) a 12-element Serial Reaction Time Task (SRTT) before a post-training Regular Sleep (RS) or Sleep Deprivation (SD) night, either followed (Day 2) by morning motor reactivation through a short SRTT testing or no motor activity. Consolidation was assessed after three recovery nights (Day 5). A 2 × 2 ANOVA carried on proportional offline gains did not evidence significant Reactivation (Morning Reactivation/No Morning Reactivation; p = 0.098), post-training Sleep (RS/SD; p = 0.301) or Sleep*Reactivation interaction (p = 0.257) effect. Our results are in line with prior studies suggesting a lack of supplementary performance gains upon reactivation, and other studies that failed to disclose post-learning sleep-related effects on performance improvement. However, lack of overt behavioural effects does not detract from the possibility of sleep- or reconsolidation-related covert neurophysiological changes underlying similar behavioural performance levels.

A case study on the stability of performance tests for serverless applications

Context:While in serverless computing, application resource management and operational concerns are generally delegated to the cloud provider, ensuring that serverless applications meet their performance requirements is still a responsibility of the developers. Performance testing is a commonly used performance assessment practice; however, it traditionally requires visibility of the resource environment. Objective:In this study, we investigate whether performance tests of serverless applications are stable, that is, if their results are reproducible, and what implications the serverless paradigm has for performance tests. Method:We conduct a case study where we collect two datasets of performance test results: (a) repetitions of performance tests for varying memory size and load intensities and (b) three repetitions of the same performance test every day for ten months. Results:We find that performance tests of serverless applications are comparatively stable if conducted on the same day. However, we also observe short-term performance variations and frequent long-term performance changes. Conclusion:Performance tests for serverless applications can be stable; however, the serverless model impacts the planning, execution, and analysis of performance tests.

Concussions in the National Hockey League: Analysis of Incidence, Return to Play, and Performance.

Background:Concussion injuries are common in professional hockey; however, their effect on player performance remains unclear.Purpose:To quantify the effect of concussions on the performance of position players in the National Hockey League (NHL).Study Design:Cohort study; Level of evidence, 3.Methods:Concussion data from the NHL were collected using publicly available databases for the seasons between 2009-2010 and 2015-2016, coinciding with new NHL concussion rules. Age, body mass index, position, number of concussions during a player’s NHL career, games played, and time on ice were recorded. Basic and advanced performance metrics were collected for 1 season pre- and postconcussion (short-term period) and 3 seasons before and after concussion (long-term period) to assess short- and long-term changes in performance. A control group of players without an identified concussion who competed during the study period was assembled for comparison. Wilcoxon signed rank tests were used to evaluate pre- to postconcussion data in the short- and long-term settings as well as to compare the cohorts at each time point.Results:Overall, 48 players were identified as having a concussion during the study period. Players missed 17.2 ± 15.1 days (mean ± standard deviation) and 7.5 ± 6.9 games postconcussion. There were no significant differences in any metric when pre- and postconcussion intraseason performance was assessed. Athletes who were concussed demonstrated significantly deceased performance metrics (assists per 60 minutes, points per 60 minutes, Corsi percentage, and Fenwick percentage) in the 3 years after the concussion as compared with the year before injury (P < .05). However, no difference was found between the concussed group and matched control group in the short- or long-term period. Players with concussion played fewer career games (856.4 ± 287.4 vs 725.7 ± 215.0; P < .05) than did controls.Conclusion:A high rate of NHL players were able to return to play after a concussion injury. Players with concussion did not experience a reduction in performance metrics in the short- or long-term setting when compared with matched controls. The concussed cohort maintained a similar workload up to 3 seasons postconcussion but played in fewer career games when compared with matched controls.

Framework of Prediction Model for Mid- to Long-Term Performance Changes of Urban Railway Facilities Based on Performance Evaluation Reports

To maintain railway facilities in an appropriate state, systematic management based on mid- and long-term maintenance plans through future performance prediction must be carried out. To this end, it is necessary to establish and utilize a model that can predict mid- to long-term performance changes of railway facilities by predicting performance changes of individual sub-facilities. However, predicting changes in the performance of all sub-facilities can be difficult as it requires large volumes of data, and railway facilities are a collection of numerous sub-facilities. Therefore, in this study, a framework for a model that can predict mid- to long-term performance changes of railway facilities through analysis of continuously accumulated performance evaluation results is proposed. The model is a system with a series of flows that can classify performance evaluation results by individual sub-facilities, predict performance changes by each sub-facility using statistical methods, and predict mid- to long-term performance changes of the facility. The developed framework was applied to 36,537 sub-facilities comprising 12 lines of two urban railways in South Korea to illustrate the model and verify its applicability and effectiveness. This study contributes in terms of its methodology in establishing a framework for predicting mid- to long-term performance changes, providing the basis for the development of an automated model able to continuously predict performance changes of individual sub-facilities. In practical terms, it is expected that railway facility managers who allow trade-off between reliability and usability can contribute to establishing the mid- to long-term maintenance plans by utilizing the model proposed in this study, instead of subjectively building them.

Assessing the Design and Operation of Redox Flow Batteries through Levelized Cost Analysis

Energy storage is expected to play an important role in enabling deep decarbonization of the electric sector by addressing the intermittencies of renewable power generation1. The redox flow battery (RFB) is a potential energy storage solution whose unique decoupling of energy and power make it increasingly competitive, on a capital cost basis, at longer discharge durations2. While the capital cost benefits to RFBs are well-described in the literature3, there are additional economic benefits associated with operation and maintenance of open systems (e.g., tune-ups, sparing strategies)4 as compared to closed systems like lithium-ion batteries. For example, crossover, undesirable species transport through the semi-permeable membrane that separates the positive and negative electrolytes, leads to comparatively rapid capacity fade in RFBs5 but can be remediated via electrolyte rebalancing, replacement, or other servicing, all of which can be performed without sacrificing or altering the reactor components. The costs necessary to maintain battery performance over time impact its economic viability, but are not captured in the conventional capital cost estimations6. This motivates the development of techno-economic models that consider the variable operating principles of different battery formats and chemistries.In this presentation, we describe a simple levelized cost of storage (LCOS) model for RFBs that captures long-term performance changes and maintenance costs by including capacity fade and recovery7. We use this model to assess the impact of different design and operational decisions on RFB cost. Specifically, we contemplate different chemistries (symmetric vs. asymmetric, finite lifetime vs. infinite lifetime), operating strategies (e.g., rebalancing schedule), performance improvements (e.g., reducing fade rates), design decisions (e.g., battery sizing), and investment approaches (e.g., electrolyte leasing). We find that there are tradeoffs in capital and operating expenses, and in many cases upfront investments pay off in long-term savings. We anticipate this analysis will provide new insights into the cost-drivers for RFBs and motivate further research efforts in the evaluation and development of new chemistries, component materials, and reactor configurations. Acknowledgements We gratefully acknowledge funding from the MIT Energy Initiative. References Intergovernmental Panel on Climate Change. Global Warming of 1.5 C. https://www.ipcc.ch/sr15/ (2018).Darling, R. M., Gallagher, K. G., Kowalski, J. A., Seungbum, H. & Brushett, F. R. Pathways to low-cost electrochemical energy storage: a comparison of aqueous and nonaqueous flow batteries. Energy Environ. Sci. 7, 3459–3477 (2014).Viswanathan, V. et al. Cost and performance model for redox flow batteries. J. Power Sources 247, 1040–1051 (2014).Yuan, X.-Z. et al. A review of all-vanadium redox flow battery durability: Degradation mechanisms and mitigation strategies. Int. J. Energy Res. 1–40 (2019) doi:10.1002/er.4607.Prifti, H., Parasuraman, A., Winardi, S., Lim, T. M. & Skyllas-Kazacos, M. Membranes for redox flow battery applications. Membranes vol. 2 275–306 (2012).US Department of Energy. Grid Energy Storage. https://www.energy.gov/sites/prod/files/2014/09/f18/Grid Energy Storage December 2013.pdf (2013).Rodby, K. E. et al. Assessing the levelized cost of vanadium redox flow batteries with capacity fade and rebalancing. J. Power Sources 460, 227958 (2020).

An experimental investigation on long-term performance of the wide-shallow bucket foundation model for offshore wind turbine in saturated sand

The bucket foundation is considered as a promising alternative to conventional foundations for offshore wind turbines (OWTs) due to its cost-effectiveness and high-reliability. The behavior of bucket foundation under static loading has been extensively investigated, while its long-term performance induced by the cyclic loading under the surrounding soil influence lack of study. This study aims to investigate the influence of one-way cyclic horizontal loading on the long-term performance of the wide-shallow bucket foundation (WSBF) model for offshore wind turbine in saturated sand by using single-gravity (1-g) model tests. Specifically, a series of cyclic experiments with varied loading conditions including load magnitude (P), load frequency (f), excitation height (H) and cycle number (N) were conducted to reveal the influence of loading conditions on dynamic characteristics and accumulated rotation of the WSBF model. Furthermore, the regression analysis method based on artificial neural network (ANN) model is proposed to determine the relationship between loading conditions and the long-term performance of the WSBF model. It is shown that the natural frequency rises and damping ratio decreases with the increase of cyclic loading number during the early cyclic stage. Afterwards, there is a declining or stable trend for the natural frequency and a rising trend for the damping ratio of the WSBF model. As for the accumulated rotation, more than 80% foundation rotation occurs in the first hundred cycles, whereas accumulated rotation for rest cycles tends to be small. Finally, multiple regression analysis and sensitivity analysis based on the ANN model are demonstrated to evaluate and predict the changes in long-term performance of the WSBF model with high accuracy in this study.

The analysis of selected physical and technological parameters of pork quality depending on intesity of the pigs growth in fattening

Article Details: Received: 2020-10-30 | Accepted: 2020-11-27 | Available online: 2021-01-31 https://doi.org/10.15414/afz.2021.24.mi-prap.71-74 The experiment was conducted to compare the differences in the physical and technological quality of pork meat with different growth intensity. The pigs were divided in accordance with the average daily gain values as followed: a) the fast-growing group (R1&gt; AGD + 0.5 SD), b) the medium-fast-growing group (R2= AGD ± 0.5 SD) and c) slow-growing group (R3&lt; AGD - 0.5 SD). For group of gilts, we found a statistically significant difference (P ≤ 0.05) in the drip loss value between the fast-growing group and the medium-growing group and the fast-growing group compared to the slow-growing group of gilts. Between the fast-growing group and the medium-growing group, as well as between the fast-growing group and the slow-growing group of gilts, the differences in shear force value were statistically highly significant at the level of P ≤ 0.01. At the same time, in the colour of meat in redness              (a* value) were found statistically significant differences between groups of barrows according to the growth rate at the level of P ≤ 0.05 and between fast and slow-growing gilts at the level of P ≤ 0.01 and medium and slow-growing gilts at the level of P ≤ 0.05. In addition, in the meat yellowness (b*) we also determined a statistically highly significant difference at the level of P ≤ 0.01 between the fastest-growing group and medium fast-growing barrows and a significant difference at the level of P ≤ 0.05 between the fast and slow-growing group of gilts. Keywords: fattening pigs, growth intensity in pig, pork quality References Brocks, L. et al. (1998). Histochemical characteristics in relation to meat quality properties in the Longissimus lumborum of fast and lean growing lines of Large White pigs. Meat Science , 50(4), 411–420. DOI: 10.1016/s0309-1740(98)00053-9 Correa, J.A. et al. (2006). Effects of slaughter weight on carcass composition and meat quality in pigs of two different growth rates. Meat Science , 72(1), 91–99. DOI: 10.1016/j.meatsci.2005.06.006 Duan, Y. et al. (2018). Effects of slaughter weight and growth rate on the longissimus muscle metabolic characteristics, and pork sensory quality in pigs of two sexes. Canadian Journal of Animal S cience, 98(2), 213–220. https://doi.org/10.1139/cjas-2017-0032 Georgsson, L. and Svendsen. J. (2002). Degree of competition at feeding differentially affects behavior and performance of group-housed growing-finishing pigs of different relative weights. Journal of Animal Science , 80(2), 376–383. https://doi.org/10.2527/2002.802376x He, Y. et al. (2016). Identifying factors contributing to slow growth in pigs. Journal of Animal Science , 94(5), 2103–2116. https://doi.org/10.2527/jas.2015-0005 Hovenier, R. (1993). Breeding for meat quality in pigs . Landbouwuniversiteit: Wageningen University &amp; Research. Latorre, M.A. et al. (2008). The relationship within and between production performance and meat quality characteristics in pigs from three different genetic lines. Livestock Science ,  115(2–3 ), 258–267. https://doi.org/10.1016/j.livsci.2007.08.013 Li, Y. 2015. Indicators of Slow Growing Pigs. Swine Scientist. Retrieved October 10, 2020 from https://wcroc.cfans.umn.edu/sites/wcroc.cfans.umn.edu/files/indicators_of_slow_growing_pigs_2015.pdf Nissen, P.M. et al. (2004). Within litter variation in muscle fiber characteristics, pig performance, and meat quality traits. Journal of Animal Science , 82(2), 414–421. · DOI: 10.2527/2004.822414x Nissen, P.M. et al. (2009). Pig meat quality predicted by growth rate at farm level. Acta Agriculturae Scandinavica, Section A – Animal Science , 59(3), 167–172. https://doi.org/10.1080/09064700903254265 Oksbjerg, N. et al. (2000). Long-term changes in performance and meat quality of Danish Landrace pigs: a study on a current compared with an unimproved genotype. Animal Science , 71(Part: 1), 81–92. Quentin, M. et al. (2003). Growth, carcass composition and meat quality response to dietary concentrations in fast-, medium-and slow-growing commercial broilers. Animal Research, 52(1), 65-77. DOI: 10.1051/animres:2003005 Quiniou, N. et al. (2002). Variation of piglets’ birth weight and consequences on subsequent performance. Livestock Production Science , 78(1), 63–70. DOI: 10.1016/S0301-6226(02)00181-1 Stupka, R. et al. (2013). Chov zvířat . Praha : Powerprint. Suzuki, K. et al. (2005). Genetic parameter estimates of meat quality traits in Duroc pigs selected for average daily gain, longissimus muscle area, backfat thickness, and intramuscular fat content. Journal of Animal Science , 83(9), 2058–2065. DOI: 10.2527/2005.8392058x Wagner, C. (2007). Influence of selection for improved growth rate on pork quality. Iowa: Iowa State University. Wright, Ch. (2017). Variation in Pig Growth Rate and Live Weight. The pig site. Retrieved October 10, 2020 from https://www.thepigsite.com/articles/variation-in-pig-growth-rate-and-live-weight Zammerini, D. et al. (2009). Effect of pig growth rate and health status on meat eating quality. Cambridge University Press, 2009(1), 103. DOI: https://doi.org/10.1017/S1752756200029422

Changes in long-term performance of fibre reinforced shotcrete due to corrosion and embrittlement

The post-crack performance of fibre reinforced shotcrete (FRS) differs from that of conventionally reinforced concrete in that the post-crack pull-out characteristics of fibres depend on the properties of the concrete matrix. Changes in the concrete matrix with time can effect substantial changes in the post-crack performance of the fibres in a way that is independent of external exposure conditions. When cracks occur in the FRS matrix, fibres may also be exposed to aggressive agents that can reduce their already small cross-sectional area at the crack and thereby diminish their post-crack performance, particularly at larger levels of deformation. The present investigation has examined how the post-crack energy absorption capacity of fibre reinforced shotcrete is affected by the interaction of aging of the concrete matrix and corrosion at cracks. The findings show that changes in performance characteristics are related to crack width and fibre type. The majority of fibre types show negligible changes in performance at low deformations over time. However, following aging, some fibre types exhibit significantly lower post-crack performance at high deformations than is evident at 28 days. The use of fibre reinforcement in shotcrete therefore needs to address aging effects, the exposure conditions regarding potential corrosion, as well as the in-service conditions of use in order to specify an appropriate maximum crack width limit that will enable the chosen fibre type to perform without risk of corrosion or embrittlement.

Procedural memory consolidation is associated with heart rate variability and sleep spindles

Sleep and memory studies often focus on overnight rather than long‐term memory changes, traditionally associating overnight memory change (OMC) with sleep architecture and sleep patterns such as spindles. In addition, (para‐)sympathetic innervation has been associated with OMC after a daytime nap using heart rate variability (HRV). In this study we investigated overnight and long‐term performance changes for procedural memory and evaluated associations with sleep architecture, spindle activity (SpA) and HRV measures (R‐R interval [RRI], standard deviation of R‐R intervals [SDNN], as well as spectral power for low [LF] and high frequencies [HF]). All participants (N = 20, M age = 23.40 ± 2.78 years) were trained on a mirror‐tracing task and completed a control (normal vision) and learning (mirrored vision) condition. Performance was evaluated after training (R1), after a full‐night sleep (R2) and 7 days thereafter (R3). Overnight changes (R2‐R1) indicated significantly higher accuracy after sleep, whereas a significant long‐term (R3‐R2) improvement was only observed for tracing speed. Sleep architecture measures were not associated with OMC after correcting for multiple comparisons. However, individual SpA change from the control to the learning night indicated that only “SpA enhancers” exhibited overnight improvements for accuracy and long‐term improvements for speed. HRV analyses revealed that lower SDNN and LF power was associated with better OMC for the procedural speed measure. Altogether, this study indicates that overnight improvement for procedural memory is specific for spindle enhancers, and is associated with HRV during sleep following procedural learning.

Air Force Research Laboratory Spacecraft Cryocooler Endurance Evaluation Facility Closing Report

The Air Force Research Laboratory (AFRL) Spacecraft Component Thermal Research Group has been devoted to evaluating lifetime performance of space cryocooler technology for over twenty years. Long-life data is essential for confirming design lifetimes for space cryocoolers. Continuous operation in a simulated space environment is the only accepted method to test for degradation. AFRL has provided raw data and detailed evaluations to cryocooler developers for advancing the technology, correcting discovered deficiencies, and improving cryocooler designs. At AFRL, units of varying design and refrigeration cycles were instrumented in state-of-the-art experiment stands to provide spacelike conditions and were equipped with software data acquisition to track critical cryocooler operating parameters. This data allowed an assessment of the technology's ability to meet the desired lifetime and documented any long-term changes in performance. This paper will outline a final report of the various flight cryocoolers tested in our laboratory. The data summarized includes the seven cryocoolers tested during 2014-2015. These seven coolers have a combined total of 433,326 hours (49.5 years) of operation.

Long-term testing of a vibration harvesting system for the structural health monitoring of bridges

Advances in energy harvesting systems are needed to power wireless sensors for structural health monitoring. Research on developing a harvesting system that converts the low frequency, non-periodic, and low-acceleration vibrations present on bridges is continued and significantly extended in this work. The mechanics of the harvester were optimized to increase its robustness and lifetime, power electronics were added, and the complete system was installed on the New Carquinez suspension bridge in California. The complete results and analysis are presented in this study. The power management circuit is added to rectify and boost the low AC output of the harvester and convert it into a usable DC voltage. The harvester design is further enhanced to significantly improve performance and robustness. During short-term on-bridge testing, the system was able to charge a 10μF capacitor to 2V DC, and the average harvester output power ranges from 1.6 to 5.0μW, depending on the location on the bridge, a 10× improvement over previous results. A long-term test of the harvesting system has been conducted, during which the performance of the system was monitored remotely using a wireless sensor network. The system improvements described in this study enabled continuous operation in the harsh bridge environment for 13 months starting April 30, 2012 and constitute a major milestone in the development of miniaturized motion harvesters. Finally, the system was retrieved and analyzed to understand and verify the cause of observed long-term performance changes.

Short-term and long-term within-person variability in performance: an integrative model.

Previous research on within-person variability in performance has largely examined short-term fluctuations and long-term changes in performance separately. The present study proposes a model-based on the cognitive-affective personality system meta--theory (Mischel & Shoda, 1995)--that integrates short-term and long-term performance variability within the 1 framework. Key propositions of the model include that short-term performance fluctuations are contingent on variability in situational cues and that situational cue-performance contingencies change over time. To test the propositions, performance data for 393 professional male tennis players were analyzed using hierarchical linear modeling. The results showed that 2 types of situational cues--resource allocation cues and task complexity--interact in complex ways to account for short-term performance variability. Moreover, as predicted, the contingency of performance on the situational cues changed over time, highlighting the importance of an integrated approach to short-term and long-term performance variability. The implications of these findings are discussed for studies of performance at work and practical applications that managers can employ to increase work performance. Furthermore, parallels are drawn with previous studies from the broader literature on dynamic job performance.

The impact of technology-motivated M&amp;A and joint ventures on the value of IT and non-IT firms: a new examination

We extend Lee and Lim (Rev Quant Financ Account 27:111–123, 2006) who provide empirical evidence on the impact of mergers and acquisitions (M&As) and joint ventures on the value of information technology (IT) and non-IT firms. Using technology-motivated transactions, we examine whether there are differences in market response to the announcement of M&As and joint ventures, and we consider the long-term performance of such firms. We find the market provides no (positive) reaction to joint ventures (M&As) at the announcement. We also present new evidence suggesting the market reacts more favorably to the announcement of technology M&As relative to joint ventures for our full sample, IT sample and non-IT sample. However, our examination of these firms’ long-term performance suggests the initial reaction is not fully supported. The findings suggest improved (declining) operating performance for joint venture (M&A) firms, and evidence to conclude joint venture firms achieve superior long-term performance changes for both accrual- and cash-based measures. To explain these inconsistencies, we employ a set of control variables previously documented as determinants of the innovation ownership decision. For joint venture firms, we find that, while the market fails to consider the importance of the firms’ R&D intensity and growth prospects in its initial reaction, these are ultimately key indicators of their future performance. The evidence also suggests the market overreacts to M&A announcements because it over-weights the impact of R&D intensity on the firms’ future performance in its initial response.

Long-term performance of rival banks around bank failures

This paper examines the impact of bank failures on the long-term performance of rival banks. We find that bank failures are associated with changes in long-term performance at rival banks. However, the change in performance is not the same for all banks. Specifically, if the bank failure is a result of a problem that is unique to the failing bank, rival bank performance increases after the failure. However, if the bank failure is due to a general economic decline, rival bank performance decreases after the bank failure. Other differences between the two subgroups are also identified.

Short-Term versus Long-Term Longitudinal Changes in Processing Speed

Background: Previous longitudinal studies of cognitive aging have focused on long-term performance changes. A recent surge of research has demonstrated that there are reliable interindividual differences in short-term cognitive performance changes. Objective: The present study links these two pathways of cognitive aging research by examining the association between short-term (learning, practice) versus long-term (development) changes in processing speed. Methods: Data from 963 elderly participants come from the Longitudinal Aging Study Amsterdam (LASA). Results: Nested latent growth curve analyses show that the amount of learning or practice in processing speed at first measurement occasion is positively related (r = 0.72) to individual differences in development of processing speed across 6 years. Conclusions: Short-term learning or practice gains in processing speed are positively associated with long-term developmental changes in processing speed in the elderly.

Bilateral peripheral vestibular lesions produce long-term changes in spatial learning in the rat

In order to investigate whether bilateral peripheral vestibular lesions cause long-term impairment of spatial learning, rats were tested in a reference memory radial arm maze learning task at least 5 weeks following a bilateral labyrinthectomy (BL) or sham control lesion. All control rats reached criterion (i.e., 1 error or less, averaged across 7 trials for 3 consecutive days of training) but only 4 of the 8 BL rats had reached criterion by day 21 of the training sessions. The control rats reached criterion more quickly than the lesioned rats (Control, 7.0 +/- 0.63 days, Lesioned, 15.8 +/- 1.4 days, t10= 5.84, p < 0.0001). This difference resulted from the greater number of errors made by the BL animals. However, the latency to respond was comparable as a result of the increased locomotor activity of the BL group (i.e., 'hyperkinesis), and the overall rate of acquisition of the task, as indicated by analysis of the exponential decrease in errors over the entire training period, was not significantly different between the 2 groups. The results of this study demonstrate that BL in rats produces long-term changes in performance in a spatial reference memory task, which are not simply due to the inability to move but may relate to the way that the brain uses vestibular information to create spatial representations and determines behavioural strategies on the basis of these representations.

The Determinants of Positive Long-Term Performance in Strategic Mergers: Corporate Focus and Cash

Using a sample selection and benchmarking methodology designed to more accurately assess merger-related changes in corporate focus, we find a significantly positive relationship between corporate focus and long-term merger performance. We find that focus-decreasing (FD) mergers result in significantly negative long-term performance. On average, FD mergers result in an over 18% loss in stockholder wealth, a 9% loss in firm value, and significant declines in operating cash flows three years after merger. Mergers that either preserve or increase focus (FPI) result in mostly insignificant changes in long-term performance. These results are consistent with prior corporate focus studies, suggesting that existing merger studies finding the opposite result are the result of measurement error. After controlling for other variables related to post-merger performance - method of payment, managerial resistance, and book-to-market ratio - we find that the positive relationship between changes in focus and long-term performance continues to hold. A continuous measure of focus change (DHI) also indicates that the magnitude of focus changes is significant. Every 10% decrease in focus results in a 9% loss in stockholder wealth, a 1+% decline in operating performance, and a 4% discount in firm value. Cash is positively related to long-term performance, but the relationship is significant only for operating performance. Cash-financed FPI mergers exhibit the best and stock-financed FD mergers the worst long-term performance. The negative performance of stock-financed FD mergers is driven by pure conglomerate mergers in the early years of our study. FPI mergers outperform FD mergers in both time periods, but differences are significant only in the earlier years. However, the DHI variable is significant in both time periods, indicating that the magnitude of corporate focus changes is the more important measure of corporate focus or diversification.

Long-term changes in performance and meat quality of Danish Landrace pigs: a study on a current compared with an unimproved genotype

AbstractAn experiment was conducted in 1995 in order to examine muscle growth, muscle histochemical properties, muscle metabolism and meat quality of two types of Danish Landrace pigs representing the growth potential of years 1976 and 1995, respectively. Danish Landrace pigs representing 1976 (slow-growing, SG) originated from a breeding station where the population was maintained without being selected for production traits such as daily gain, food conversion ratio and meat content. Pigs representing Danish Landrace of 1995 (fast-growing, FG) were bought from certified Danish pig breeders. The pigs were simultaneously tested for performance from 40 to 95 kg live weight. The daily gain, food conversion ratio and meat content of the carcass were improved proportionately by 0·43, 0·24 and 0·03 in FG pigs compared with SG pigs. In m. longissimus dorsi (LD), the cross-sectional area of muscle fibres was smaller in FG pigs compared with SG pigs indicating increased muscle fibre number. Data further suggest increased satellite cell proliferation in muscles of FG pigs. Serum from FG pigs stimulated the proliferation of C2C12 muscle cells to a greater extent than serum from SG pigs, although the serum level of insulin-like growth factor 1 did not differ between pig types. The effect of serum on protein turn-over of C2C12 myotubes did not depend on pig type. The glycogen concentration in the LD did not differ significantly between pig types, while the activity of citrate synthase, 3-OH-acyl-CoA-dehydrogenase, and lactate dehydrogenase were higher in the LD of SG pigs compared with FG pigs. Pork chop colour of FG pigs was proportionately 0·09 lighter (L⋆) and 0·13 less red (a⋆) than pork chops of SG pigs. The total muscle pigment concentration in the LD, m. biceps femoris and m. vastus intermedius was proportionately reduced by 0·17, 0·19 and 0·11, respectively, in FG pigs compared with SG pigs. In the LD, the concentration of myoglobin was proportionately reduced by 0·17 in FG pigs. The chemical composition of the LD differed between pig types such that the water content was higher and protein content lower in LD from FG pigs compared with SG pigs. The pH of the LD measured 45 min and 24 h post mortem, drip loss and thawing loss were similar for both pig types. Meat tenderness of conditioned pork chops of FG pigs was slightly reduced in accordance with a decreased intensity of the 31 kDa peptide band and increased cooking loss. The present study suggests that increased muscle fibre number and rate of muscle DNA deposition (satellite cell proliferation) have contributed to the increased muscle growth as a result of selection for performance in pigs under Danish conditions. However, the increase in growth performance was accompanied by deterioration in muscle colour and slightly reduced tenderness.