bluuebunny/crossref_metadata_2025 huggingface dataset:
Vascular BDNF expression and oxidative stress during aging and the development of chronic hypertension
Authors: Amoureux Sébastien , Lorgis Luc , Sicard Pierre , Girard Claude , Rochette Luc , Vergely Catherine
Published: January 2011

Brain‐derived neurotrophic factor (BDNF) and TrK receptors play an important role in vascular development and response to injury. In this study, we investigated the participation of the BDNF/TrK pathway and oxidative stress during the development of hypertension in spontaneously hypertensive rats (SHR). In SHR and normotensive rats (WKY) at 6 and 13 weeks of age, we studied (i) plasma antioxidant capacity, (ii) production of superoxide and NAD(P)H oxidase activity in aorta (iii) plasma BDNF and vascular expression of BDNF, TrKB, NAD(P)H oxidase subunits, AT1 receptor, and MCP‐1. In 6‐ and 13‐week‐old SHR aorta, superoxide level was twice than in WKY aorta. At 13 weeks, when blood pressure in SHR was 60 mmHg higher in SHR than in WKY, an enhancement of NAD(P)H oxidase activity in SHR was associated with an increase in p47phox, AT1, and BDNF expression in vessels. MCP‐1 expression increased with blood pressure. Our study demonstrated that in SHR rats, an increase in levels of vascular oxidative stress and in aortic BDNF and TrKB expression occurs prior to the rise in blood pressure, while a reinforcement of vascular and circulating oxidative stress markers is brought about later by hypertension.
Resisting Institutionalization: Religious Professionals in the Emerging Church*
Authors: Packard Josh
Published: January 2011

This article discusses how organizations can resist normative institutional pressures associated with the use of formally trained and credentialed professionals. This research draws on neoinstitutional theories of isomorphism and utilizes a framework of religious training developed by Finke and Dougherty (2002), which emphasizes both the social and religious capital gained during professionalization, to show that resistance to normative institutional pressures is possible. The data demonstrate that organizations which act to reformulate the role of religious professionals in a way which limits both the opportunities and ability of clergy to implement and maintain organizational routines and processes can successfully avoid normative institutional forces. This research draws on over 50 interviews and 100 hours of fieldwork with people in the Emerging Church, a religious movement that has arisen in the last 25 years as a response to increasing distrust of institutional authority. This study helps to close the gap between institutional studies of organizations and the sociology of religion by suggesting that some, currently overlooked, organizational activities can be more accurately understood as deliberate attempts to resist institutionalizing forces.
The Northern “Black Metropolis” of the Early Twentieth Century: A Reappraisal*
Authors: Boyd Robert L.
Published: January 2011

The new perspective of the “Black Metropolis” implies that conditions created by the Great Migration helped blacks in northern cities to establish themselves in professional, entrepreneurial, and artistic, entertainment and mass media occupations. The present study evaluates this argument with Census data, focusing on the nation’s largest black communities, Harlem (New York) and Bronzeville (Chicago), at time points that capture the first wave of the Great Migration. Contrary to expectations, the odds of black employment in the aforesaid occupations declined or remained essentially unchanged in both communities over the study period. Harlem and Bronzeville were surprisingly limited in their potential to offer opportunities for blacks to become professionals, entrepreneurs, and artists, entertainers and writers, perhaps because these communities were saturated by the tremendous influx from the South. Accordingly, it is recommended that the Black Metropolis perspective be modified, to provide a more accurate view of the consequences of the Great Migration.
Investigating Customer Racial Discrimination in the Secondary Baseball Card Market*
Authors: Primm Eric , Piquero Nicole Leeper , Piquero Alex R. , Regoli Robert M.
Published: January 2011

A growing body of literature in a variety of disciplines has appeared over the last 20 years examining customer racial bias in the secondary sports card market; however, consensus on the matter has yet to emerge. In this article, we explore the more subtle ways that a player’s race/ethnicity may affect the value of his sports card including a player’s skin tone (light‐ to dark‐skinned). Data were obtained for 383 black, Latino, and white baseball players who had received at least one vote for induction into Major League Baseball’s Hall of Fame including their career performance statistics, rookie card price, card availability, Hall of Fame status, and skin tone. Findings indicate that card availability is the primary determinant of card value while a player’s skin tone has no direct effect. Subsequent analysis demonstrates that a player’s race (white/non‐white) rather than skin tone did have an effect as it interacts with Hall of Fame status to influence his rookie card price.
Reducing costs in flow‐cytometric counting of residual white blood cells in blood products: utilization of a single‐platform bead‐free flow‐rate calibration method
Authors: Fischer Johannes C. , Quenzel Ernst M. , Moog Rainer , Wenzel Folker , Riethmacher Regina , Tutschek Boris , Giers Günther
Published: January 2011

BACKGROUND: Commercial flow‐cytometric methods for counting residual white blood cells (rWBCs) in leukoreduced blood products use calibration beads for estimation of the measured sample volume. A bead‐free flow‐rate calibration method is developed and validated.

STUDY DESIGN AND METHODS: The analyzed volume was calculated by acquisition time (ACQ). Twenty‐nine spiking series of red blood cell (RBC) or platelet (PLT) products were prepared containing levels ranging from 0.08 × 106 up to 2048 × 106 WBCs/L. Nearly WBC‐free triple‐leukofiltered RBCs or PLT concentrates (PCs) served as background. Propidium iodide (PI) was used to identify rWBCs. Five RBC series were compared against a commercially available kit (LeukoSure, Beckman Coulter). Routine capabilities were tested on 41 RBC and 92 PC samples of two independent transfusion services.

RESULTS: The lower detection limit in RBC was 0.08 × 106 rWBCs/L for ACQ and 0.16 for LeukoSure. Criteria for linearity, accuracy, and precision were fulfilled within the range of 0.5 × 106 to 512 × 106 WBCs/L. For PCs, all these criteria were fulfilled between 0.5 × 106 and 32 × 106 rWBCs/L (lower detection limit of 0.25) for PI. ACQ and LeukoSure agreed sufficiently (81%) when tested on routine RBCs or PCs.

CONCLUSION: A residual WBC count of fewer than 0.5 × 106 WBCs/L can be accurately counted using the ACQ approach at a total reagent cost of less than 0.5€ per sample.
Down regulation of human natural killer cell–mediated cytolysis induced by blood transfusion: role of transforming growth factor‐β1, soluble Fas ligand, and soluble Class I human leukocyte antigen
Authors: Ghio Massimo , Contini Paola , Negrini Simone , Mazzei Clemente , Zocchi Maria R. , Poggi Alessandro
Published: January 2011

BACKGROUND: Human natural killer (NK) cells are thought to play a role in antiviral response and tumor immune surveillance. The molecular mechanisms of down regulation of NK‐cell activity observed after red blood cell (RBC) transfusion is still undefined.

STUDY DESIGN AND METHODS: Both effects of blood transfusion (ex vivo) and supernatants (SNs) derived from RBC units unstored (RBC‐0) or stored for 5 or 30 days (RBC‐5 or ‐30, respectively) in vitro were analyzed on NK cell–mediated cytolytic activity.

RESULTS: We have found that NK cells isolated from transfused patients on Day 3 lysed the NK‐sensitive target cells K562 to a lesser extent than before transfusion. This down regulation of NK‐cell activation was evident also for NK‐cell killing mediated through the engagement of NK cell–activating receptors as NKG2D, NKp30, NKp46, and CD16. Transfused patients reacquired NK cell–mediated cytolytic activity from Day 5 to Day 7 after transfusion. SN from RBC‐30, but not from RBC‐0 or RBC‐5, strongly inhibited the generation of lymphokine‐activated killer (LAK) cells and lysis of the NK‐resistant target cell Jurkat in a dose‐dependent manner. Transforming growth factor‐β1 (TGF‐β1) blocking antibodies partially restored the generation of LAK activity. In addition, the depletion of both soluble Class I human leukocyte antigens (sHLA‐I) and soluble Fas ligand (sFasL) from SN of RBC‐30 completely restored the generation of LAK activity.

CONCLUSIONS: Altogether, these findings would support the idea that blood transfusion–mediated down regulation of NK‐cell activity is mediated by sHLA‐I, sFasL, and TGF‐β1.
Use of hemovigilance data to evaluate the effectiveness of diversion and bacterial detection
Authors: Robillard Pierre , Delage Gilles , Karl Itaj Nawej , Goldman Mindy
Published: January 2011

BACKGROUND: Several preventive measures, including diversion of the first aliquot of blood and culturing of platelet (PLT) components, have been implemented to decrease the risk of transfusion‐transmitted bacterial infections (TTBIs). We evaluated the effectiveness of these measures in Québec using hemovigilance data from January 2000 to December 2008.

STUDY DESIGN AND METHODS: Adverse transfusion reactions were reported to the Québec Ministry of Health by transfusion safety officers. Initial aliquot diversion, already in place for apheresis PLTs, was added to all whole blood collections in early 2003. Bacterial detection was implemented in March 2003 for apheresis PLTs and February 2005 for whole blood–derived PLTs (WBDPs).

RESULTS: The incidence of probable and definite TTBIs associated with WBDPs decreased from 1 in 2655 to 1 in 27,737 five‐unit pools (p = 0.004) after implementation of diversion. There were no reports of TTBIs with WBDPs after culture was added to diversion, further reducing the risk to 1 in 58,123 five‐unit pools (p < 0.001). There was only one TTBI associated with apheresis PLTs during the 9‐year period, which occurred after implementation of both diversion and culture.

CONCLUSION: Hemovigilance data demonstrated a highly significant decrease in TTBIs associated with WBDPs, mainly attributed to the implementation of diversion. However, diversion and culture do not totally abolish the risk of TTBIs.
Donation frequency of blood donors participating in a prospective cohort study of iron status
Authors: Bahrami Shrein H. , Guiltinan Anne M. , Schlumpf Karen S. , Scott Erik , Banks Linda L. , D'Andrea Pam , Hartman Elizabeth L. , Vij Vibha , Wright David J. , Spencer Bryan , Murphy Edward L. ,   for the NHLBI Retrovirus Epidemiology Donor Study‐II (REDS‐II)
Published: January 2011

BACKGROUND: Blood centers are interested in understanding determinants of frequent blood donation. We hypothesized that participation in uncompensated research could result in higher donation rates.

STUDY DESIGN AND METHODS: Donation rates for 2425 subjects from six US blood centers enrolled in the Retrovirus Epidemiology Donor Study‐II Donor Iron Status Evaluation Study were compared to those of nonenrolled donors (n = 202,383). Over 15 months, we compared mean donation rates and adjusted rate ratios (RRs) between enrolled and nonenrolled for three subgroups, first‐time, reactivated, and frequent donors, and donation rates before and after the study enrollment period for frequent donors only.

RESULTS: Enrolled donors had higher 15‐month mean donation rates than nonenrolled donors (first‐time, 1.21 [RR = 1.91]; reactivated, 1.68 [RR = 1.83]; frequent, 3.40 [RR = 1.12]). However, frequent donors donated at approximately the same rate after enrollment as they did before enrollment in the study (3.62 per 15 months [RR = 1.12]).

CONCLUSION: Donors enrolled in the study donated at a higher rate than nonenrolled donors, but frequent donors remained consistent in their donation frequency both before and after enrollment. Although increased donation rates could have been causally related to study enrollment, we cannot rule out an enrollment bias whereby more committed donors were more likely to enroll in the study.
Allergic transfusion reactions to platelets are associated more with recipient and donor factors than with product attributes
Authors: Savage William J. , Tobian Aaron A. , Fuller Alice K. , Wood Robert A. , King Karen E. , Ness Paul M.
Published: January 2011

BACKGROUND: Mechanisms of allergic transfusion reactions (ATRs) are not well understood. The aim of this study was to distinguish recipient‐, donor‐, and product‐specific factors associated with ATRs.

STUDY DESIGN AND METHODS: We conducted a retrospective cohort study of apheresis platelet (AP) products transfused from April 2000 through March 2010. The concordance rate of ATRs when split AP products were transfused to at least two individuals was compared to the overall ATR rate among all AP products. Per‐person ATR rates also were compared to the overall ATR rate.

RESULTS: We observed 1616 ATRs among 93,737 transfusions, for an overall incidence of 1.72% (95% confidence interval [CI], 1.64%‐1.81%). Of the 1616 ATRs, 630 occurred when split AP products were transfused to at least two recipients. Of these 630 AP products, ATRs were observed in at least two different recipients of the same AP collection only 6 of 630 times, for a concordant incidence of 0.95% (95% CI, 0.35%‐2.06%), which is similar to the overall ATR rate (p = 0.17). On an individual level, 30.0% of recipients had ATR rates of more than 5%, and these 30.0% accounted for 62.1% of ATRs. Donors of AP products associated with concordant ATRs donated AP products that had an ATR rate of 5.8% (95% CI, 3.1%‐9.7%), which is higher than the overall ATR rate (p < 0.001).

CONCLUSIONS: An observed ATR does not predict an ATR in a different recipient of a split AP product. A minority of platelet recipients accounts for the majority of ATRs. Some donors are strongly associated with ATRs. Consequently, recipient and donor factors are implicated in the mechanism of ATRs.
Matrix Metalloproteinase Activity Causes VEGFR‐2 Cleavage and Microvascular Rarefaction in Rat Mesentery
Authors: TRAN EDWARD D. , YANG MING , CHEN ANDREW , DELANO FRANK A. , MURFEE WALTER L. , SCHMID‐SCHÖNBEIN GEERT W.
Published: January 2011

Please cite this paper as: Tran, Yang, Chen, DeLano, Murfee and Schmid‐Schönbein (2011). Matrix Metalloproteinase Activity Causes VEGFR‐2 Cleavage and Microvascular Rarefaction in Rat Mesentery. Microcirculation 18(3), 228–237.

A complication of the spontaneously hypertensive rat (SHR) is microvascular rarefaction, defined by the loss of microvessels. However, the molecular mechanisms involved in this process remain incompletely identified. Recent work in our laboratory suggests that matrix metalloproteinases (MMPs) may play a role by cleavage of the vascular endothelial growth factor receptor 2 (VEGFR‐2). In order to further delineate the role for MMPs in microvascular rarefaction, the objective of the current study was to examine the relationship in the same tissue between MMP activity, VEGFR‐2 cleavage and rarefaction. Using an in vivo microzymographic technique, we show significantly enhanced levels of MMP‐1, ‐1/‐9, ‐7, and ‐8 activities, but not MMP‐2 and ‐3 activities, along mesenteric microvessels of the SHR compared to its normotensive control, Wistar Kyoto rat. Based on immunohistochemical methods, the SHR exhibited a decreased labeling of the extracellular, but not the intracellular, domain of VEGFR‐2 along mesenteric microvessels. Chronic MMP inhibition served to attenuate VEGFR‐2 cleavage and microvascular network rarefaction in the SHR mesentery. These results spatially link MMP‐induced VEGFR‐2 cleavage and rarefaction in the mesentery of the SHR and thus support the hypothesis that MMPs serve as regulators of microvascular dysfunction in hypertension.
High incidence and costs for anterior cruciate ligament reconstructions performed in Australia from 2003–2004 to 2007–2008: time for an anterior cruciate ligament register by Scandinavian model?
Authors: Janssen K. W. , Orchard J. W. , Driscoll T. R. , van Mechelen W.
Published: January 2011

The aim of this paper was to provide a descriptive epidemiology of anterior cruciate ligament (ACL) reconstructions in Australia. Data on all ACL reconstructions were collected from July 1, 2003 till June 30, 2008. Main outcome measures were the incidence of ACL reconstructions for Australia, per age group, sex and sport, including estimates of direct costs. There were 50 187 ACL reconstructions over the 5‐year period studied. The population‐based incidence of ACL reconstructions per 100 000 person‐years was 52.0 [95% confidence intervals (CI): 51.6; 52.5], higher than previously published incidences from other western countries (Scandinavia 32–38). The population incidence rose rapidly through adolescence and early adulthood and then gradually declined. Males had a higher population incidence than females. Skiing had the highest incidence of ACL reconstructions per 100 000 person‐years, followed by Australian rules football, rugby, netball and soccer. The total estimated hospital costs associated with ACL reconstruction surgery were over A$75 million (€45 million) per year. Further research is necessary to examine the causes for the higher population incidence of ACL reconstructions in Australia compared with other countries. The establishment of a national register of ACL injuries, similar to those developed in Scandinavia should be considered.
Increased external hip‐rotation strength relates to reduced dynamic knee control in females: paradox or adaptation?
Authors: Bandholm T. , Thorborg K. , Andersson E. , Larsen T. , Toftdahl M. , Bencke J. , Hölmich P.
Published: January 2011

The purpose of the present study was to examine the relationship between hip muscle strength (abduction and external rotation) and frontal‐plane knee control during drop jumping in recreational female athletes. Thirty‐three healthy young recreational female athletes were included. Maximal isometric hip abduction and external rotation torque were measured using hand‐held dynamometry, and frontal‐plane knee control during drop jumping was assessed using three‐dimensional motion analysis. Frontal‐plane knee control during drop jumping was expressed as the absolute (cm) and relative (cm/cm body height) change in distance between lateral knee markers from foot–ground contact to the time of minimal marker distance during the contact phase of the jump. Greater maximal external hip‐rotation torque correlated significantly with greater absolute (r=0.48, P=0.005) and relative (r=0.43, P=0.012) change in knee marker distance during drop jumping. Maximal hip‐abduction torque did not correlate with the absolute (r=0.18, P=0.31) or relative (r=0.19, P=0.29) change in knee marker distance during drop jumping. Contrary to our expectations, greater maximal external hip‐rotation torque was related to greater change in knee marker distance during drop jumping (reduced frontal‐plane knee control) in recreational female athletes.
Anaerobic contribution during maximal anaerobic running test: correlation with maximal accumulated oxygen deficit
Authors: Zagatto A. , Redkva P. , Loures J. , Filho C. Kalva , Franco V. , Kaminagakura E. , Papoti M.
Published: January 2011

The aims of this study were: (i) to measure energy system contributions in maximal anaerobic running test (MART); and (ii) to verify any correlation between MART and maximal accumulated oxygen deficit (MAOD). Eleven members of the armed forces were recruited for this study. Participants performed MART and MAOD, both accomplished on a treadmill. MART consisted of intermittent exercise, 20 s effort with 100 s recovery, after each spell of effort exercise. Energy system contributions by MART were also determined by excess post‐exercise oxygen consumption, lactate response, and oxygen uptake measurements. MAOD was determined by five submaximal intensities and one supramaximal intensity exercises corresponding to 120% at maximal oxygen uptake intensity. Energy system contributions were 65.4±1.1% to aerobic; 29.5±1.1% to anaerobic a‐lactic; and 5.1±0.5% to anaerobic lactic system throughout the whole test, while only during effort periods the anaerobic contribution corresponded to 73.5±1.0%. Maximal power found in MART corresponded to 111.25±1.33 mL/kg/min but did not significantly correlate with MAOD (4.69±0.30 L and 70.85±4.73 mL/kg). We concluded that the anaerobic a‐lactic system is the main energy system in MART efforts and this test did not significantly correlate to MAOD.
Factors influencing result of autologous chondrocyte implantation in osteochondral lesion of the talus using second look arthroscopy
Authors: Lee K. T. , Lee Y. K. , Young K. W. , Park S. Y. , Kim J. S.
Published: January 2011

This study is to know the factors that may affect cartilage repair after autologous chondrocyte implantation (ACI) for the treatment of an osteochondral lesion of the talus (OLT) as seen through a second look arthroscopy. A total of 38 patients who had ACI treatment for OLT underwent a second look arthroscopy 1 year after the ACI operation. A modified magnetic resonance observation of cartilage repair tissue (MOCART) scoring system was used to assess the outcome of the repaired cartilage. Influencing factors were sex, accompanied procedure, location, site, depth, pre‐operative AOFAS score, size and age. Factors that may affect cartilage repair after ACI treatment for OLT were evaluated. Of the different factors assessed, sex (P=0.75), accompanied procedure (P=0.50), depth (P=0.08), location (P=0.54), site (P=0.50) and pre‐operative AOFAS score (P=0.42) were found not to affect cartilage repair after ACI treatment for OLT. The size of the lesion (P=0.0021) and patient's age (P=0.01) were the influential factors. As a result, factors affecting repaired cartilage formation after ACI of OLT were found through the second look arthroscopy. It was determined that not all of the factors affecting the clinical outcome after ACI for the repair of an OLT affected cartilage repair after ACI.
The role of pro‐inflammatory and immunoregulatory cytokines in tendon healing and rupture: new insights
Authors: Schulze‐Tanzil G. , Al‐Sadi O. , Wiegand E. , Ertel W. , Busch C. , Kohl B. , Pufe T.
Published: January 2011

Owing to limited self‐healing capacity, tendon ruptures and healing remain major orthopedic challenges. Increasing evidence suggests that post‐traumatic inflammatory responses, and hence, cytokines are involved in both cases, and also in tendon exercise and homeostasis. This review summarizes interrelations known between the cytokines interleukin (IL)‐1β, tumor necrosis factor (TNF)α, IL‐6 and vascular endothelial growth factor (VEGF) in tendon to assess their role in tendon damage and healing. Exogenic cytokine sources are blood‐derived leukocytes that immigrate in damaged tendon. Endogenous expression of IL‐1β, TNFα, IL‐6, IL‐10 and VEGF was demonstrated in tendon‐derived cells. As tendon is a highly mechanosensitive tissue, cytokine homeostasis and cell survival underlie an intimate balance between adequate biomechanical stimuli and disturbance through load deprivation and overload. Multiple interrelations between cytokines and tendon extracellular matrix (ECM) synthesis, catabolic mediators e.g. matrix‐degrading enzymes, inflammatory and angiogenic factors (COX‐2, PGE2, VEGF, NO) and cytoskeleton assembly are evident. Pro‐inflammatory cytokines affect ECM homeostasis, accelerate remodeling, amplify biomechanical adaptiveness and promote tenocyte apoptosis. This multifaceted interplay might both contribute to and interfere with healing. Much work must be undertaken to understand the particular interrelation of these inflammatory and regulatory mediators in ruptured tendon and healing, which has relevance for the development of novel immunoregulatory therapeutic strategies.
Hydrophobic‐Domain‐Dependent Protein–Protein Interactions Mediate the Localization of GPAT Enzymes to ER Subdomains
Authors: Gidda Satinder K. , Shockey Jay M. , Falcone Mina , Kim Peter K. , Rothstein Steven J. , Andrews David W. , Dyer John M. , Mullen Robert T.
Published: January 2011

The endoplasmic reticulum (ER) is a dynamic organelle that consists of numerous regions or ‘subdomains’ that have discrete morphological features and functional properties. Although it is generally accepted that these subdomains differ in their protein and perhaps lipid compositions, a clear understanding of how they are assembled and maintained has not been well established. We previously demonstrated that two diacylglycerol acyltransferase enzymes (DGAT1 and DGAT2) from tung tree (Vernicia fordii) were located in different subdomains of ER, but the mechanisms responsible for protein targeting to these subdomains were not elucidated. Here we extend these studies by describing two glycerol‐3‐phosphate acyltransferase‐like (GPAT) enzymes from tung tree, GPAT8 and GPAT9, that both colocalize with DGAT2 in the same ER subdomains. Measurement of protein–protein interactions using the split‐ubiquitin assay revealed that GPAT8 interacts with itself, GPAT9 and DGAT2, but not with DGAT1. Furthermore, mutational analysis of GPAT8 revealed that the protein's first predicted hydrophobic region, which contains an amphipathic helix‐like motif, is required for interaction with DGAT2 and for DGAT2‐dependent colocalization in ER subdomains. Taken together, these results suggest that the regulation and organization of ER subdomains is mediated at least in part by higher‐ordered, hydrophobic‐domain‐dependent homo‐ and hetero‐oligomeric protein–protein interactions.
Wound healing and regenerative strategies
Authors: Nauta A , Gurtner GC , Longaker MT
Published: January 2011

Oral Diseases (2011) 17, 541–549

Wound healing is a complex biological process that affects multiple tissue types. Wounds in the oral cavity are particularly challenging given the variety of tissue types that exist in close proximity to one another. The goal of regenerative medicine is to facilitate the rapid replacement of lost or damaged tissue with tissue that is functional, and physiologically similar to what previously existed. This review provides a general overview of wound healing and regenerative medicine, focusing specifically on how recent advances in the fields of stem cell biology, tissue engineering, and oral disease could translate into improved clinical outcomes.
Bounded Ethicality in Negotiations1
Authors: Bazerman Max H.
Published: January 2011

Most negotiators think of themselves as good people, and most negotiators act in ethically questionable ways at times. How can these two descriptions be reconciled? This paper follows Bazerman and Tenbrunsel (2011) in arguing that good people often engage in unethical acts without their own awareness of doing so. This paper specifically explores how negotiators may be prejudiced, favor in‐groups, and overclaim in negotiation, without knowing that they are doing anything wrong.
When Does Taking a Break Help in Negotiations? The Influence of Breaks and Social Motivation on Negotiation Processes and Outcomes
Authors: Harinck Fieke , De Dreu Carsten K. W.
Published: January 2011

Most negotiations are interrupted from time to time to reflect on the negotiation or to do other pressing tasks. This study investigated how these breaks and the thoughts during these breaks influence subsequent negotiation behavior. Prosocially motivated dyads, with a tendency to think cooperatively, and proself‐motivated dyads, with a tendency to think competitively, engaged in a negotiation in which there was a 3‐min break. During this break, either they could reflect upon the negotiation or they did a distraction task. After the reflect break, but not after the distract break, prosocial dyads displayed more concern for other, engaged in more cooperative negotiation, and reached more agreements than proself dyads. We conclude that breaks are constructive if, and only if, negotiators reflect on their negotiation when having a prosocial orientation.
Design and Testing of a Carbon Foam Based Supercooler for High Heat Flux Cooling in Optoelectronic Packages
Authors: Yuen Walter W. , Tu Jianping , Tam Wai-Cheong , Blumenthal Dan
Published: January 2011

The feasibility of using carbon foam as a heat sink and heat spreader in optoelectronic packages is assessed. A “supercooler” is designed, fabricated and tested to verify its cooling capability under high heat flux conditions in a typical optoelectronic package. The supercooler uses carbon foam as a primary heat transfer material. Water is soaked into the carbon foam and under evacuated pressure, boiling is initiated under the heating region to provide enhanced cooling. Experiments were conducted for a heat flux of up to 400 W/cm2 deposited over a heating area of 0.5 mm × 5 mm. Two dimensional transient temperature distributions were recorded using a high speed infrared camera. Data were obtained for steady heating, as well as periodic heating with frequency up to 8 hz. Results show that the supercooler is very efficient in dissipating heat away from the heating region. Data obtained under 8 hz periodic heating with a peak power input of 10W, for example, showed that the temperature of the heated surface rises quickly to a local maximum of 15 to 20 °K above the ambient. The heated surface is then cooled uniformly back to a near ambient condition (with a maximum temperature of less than 5 °K above ambient) during the cooling half of the cycle (less than 0.0625 sec after the heating is turned off). The average cooling rate during the cooling period exceeds 170 °K/s. A numerical model, based on COMSOL, is developed to interpret the experimental data and to provide insights on the relevant physics responsible for the rapid cooling. Numerical data are presented to demonstrate how the supercooler can be further improved and adopted for other applications.
Continuous Wavelet Transform Based Nanoscale Strain Field Measurement Using Moire´ Interferometry With Phase Shifting
Authors: Chen Bicheng , Basaran Cemal
Published: January 2011

Moire´ Interferometry (MI) provides real-time full strain field measurement for the structure under the dynamic loading. It has been successfully applied to the reliability testing of the electronic packaging under different loadings (e.g. thermal cycling, electrical current stressing and etc). The miniaturization of the microelectronic packaging calls for the operation of MI at a level with higher sensitivity and better resolution. The proposed operation of MI combines two novel methods in the interferometry, phase shifting (PS) and continuous wavelet transform (CWT) to achieve a 164 nm/pixel spatial resolution. The entire operation procedure is completed automatically by computer programs. A two-level zooming system is designed and implemented in MI to give a high spatial resolution. The idea of combination of CWT and PS here is to put both spatial phase calculation and temporal phase calculation together. By introducing both the spatial and temporal redundancy, the authors show that the hybrid methods take the advantages from both of them. Furthermore, the direct calculation of the spontaneous spatial frequency of the interferogram is carried out using the property of the maximum power ridge of CWT. This method doesn’t require unwrapping and differentiation, which avoid the possible numerical noise introduced in these two steps. In the proposed system, pixel by pixel in-plane strain tensors can be calculated from the intensity map of interferograms using phase-based method for MI in contrast with the traditional fringe counting. The resulting strain tensor can be used to model constitutive relationship or compare with finite element analysis results. A thermal experiment on BGA packaging is used to demonstrate the advantages of the proposed new design.
Thermal-Electrical Co-Optimization of Block-Level Floorplanning in 3D Integrated Circuits
Authors: Jain Ankur , Alam Syed , Pozder Scott , Jones Robert E.
Published: January 2011

While the stacking of multiple strata to produce 3D integrated circuits improves interconnect length and hence reduces power and latency, it also results in the exacerbation of the thermal management challenge due to the increased power density. There is a need for design tools to understand and optimize the trade-off between electrical and thermal design at the device and block level. This paper presents results from thermal-electrical co-optimization for block-level floorplanning in a multi-die 3D integrated circuit. A method for temperature computation based on linearity of the governing energy equation is presented. This method is shown to be faster and more accurate than previously used resistance-network based approaches and full-scale FEM simulations. This method is combined with previously reported electrical delay models for 3D ICs to simultaneously optimize both the maximum temperature and the interconnect length. Results outline the various trade-offs between thermal and electrical considerations. It is shown that co-optimization of thermal and electrical objectives results in a floorplan that is attractive from both perspectives. Constraints placed by the 3D IC manufacturing process on design are outlined, showing that the cheapest manufacturing options may not result in optimal electrical and thermal design. In particular, the wafer-on-wafer bonding process requires the two die to be identical, which results in a severe design constraint, particularly on the thermal goal due to the overlap of high power density blocks. Results presented in this work highlight the need for thermal and electrical co-design in multistrata microelectronics, and for reconciling manufacturing and design considerations in order to develop practical design tools for 3D integrated circuits.
Evaluation and Improvement of Micro-Drilled-Hole Wall Quality in Printed Wiring Boards Made of Glass Fiber-Reinforced Plastics
Authors: Ogawa Keiji , Nakagawa Heisaburo , Matsudaira Masatoshi
Published: January 2011

With recent worldwide-use and the rapid spread of electric and electronic equipment, printed wiring boards (PWBs) are being miniaturized and made multifunctional. Miniaturizing the equipment and making it high performance are accompanied by an increase in the number of small diameter through holes for circuit connections available to the PWBs. Such tendency needs the large number of smaller diameter drilling with shorter pitches. Moreover, the improvement of drilled-hole wall quality for PWBs might be demanded by such trends. Here, PWBs are often made of fiber-reinforced plastics (FRP) for the insulating layers and copper foil for the circuit layers. A woven glass fiber cloth is generally used for PWBs. Therefore, delamination might occur during drilling and affect the surface roughness of the drilled-hole wall. Such wrong surface roughness of drilled-hole wall should be avoided because it might reduce the reliability of insulating between next holes by ion migration of copper plating progressing along the delamination. Revealing of its mechanism is expected to be more important with smaller diameter with smaller electric devices. However, it might be difficult because the micr-drilling of FRP shows is a complex phenomenon because it consists of different materials. Therefore, this paper investigates the proper method to improve drilled-hole wall quality by evaluating the drill temperature rising mechanism and the surface generation mechanism of micro-drilled-hole walls of PWBs made of GFRP. The following results were reached: (1) A drill temperature rising mechanism was conducted. (2) Drill temperature tends to increase with the frictional torque between the hole wall and the margin part of drill. (3) Frictional torque increases with the spring-back of the drilled-hole wall during drilling. (4) The surface roughness of the drilled-hole wall of the GFRP plate is affected by the breakdown of the glass fiber and is mainly caused by the cutting edge of the outer corner except the margin part of the drill. (5) A drilling method with higher fiber bonding strength, such as drilling with compressing PWBs in the thickness direction, effectively improves the drilled-hole wall quality.
Local Cooling Control of Data Centers With Adaptive Vent Tiles
Authors: Beitelmal Monem H. , Wang Zhikui , Felix Carlos , Bash Cullen , Hoover Christopher , McReynolds Alan
Published: January 2011

Local airflow distribution in data center environments has historically been accomplished through ventilation tiles distributed over a raised floor air distribution plenum. The tiles are initially configured upon the commissioning of the facility and, as IT equipment configuration changes with time, the tiles are adjusted accordingly. However, tile adjustment is a manual process that is error-prone and often non-intuitive. Tile flow rates are a strong function of under floor plenum pressure distribution which is subject to change as tile layouts are reconfigured. Thermal models are often developed to assist with layout changes, but these models can be time-consuming to generate and require skilled users to achieve accurate results. This paper presents an adaptive vent tile (AVT) for use in raised floor data centers that can adapt to the needs of nearby IT equipment. We present a multi-input-multi-output (MIMO) AVT controller that automatically and dynamically adjusts a multiplicity of AVT openings in coordination such that thermal management requirements are met with minimum use of airflow. We describe the development of dynamic models and algorithm design of the MIMO controller. The controller was evaluated with a set of AVT units in a production data center environment. Results show that the controller can optimize local airflow distribution, provide fine-grained rack intake temperature control and respond to disturbances in a manner that is not achievable through static distribution of tiles.
Designing Environmentally Sustainable Computer Systems Using Networks of Exergo-Thermo-Volume Building Blocks
Authors: Shah Amip , Patel Chandrakant D. , Bash Cullen
Published: January 2011

As regulation and competition drives the creation of environmentally sustainable systems, cradle-to-cradle life-cycle assessment (LCA) methodologies are becoming increasingly commonplace. However, existing LCA techniques are often laborious and costly to implement. Moreover, while LCA provides great insight into the impact of a given product or service, the translation of LCA outputs into iterative design inputs is not straightforward. A tighter linkage between product design and LCA methods is desired. In this paper, we propose creating such a linkage through the method of “exergo-thermo-volumes”. Specifically, we consider the design of an enterprise server with multiple heat dissipating components. Each of these heat dissipating components can be represented as an exergo-thermo-volume (ETV). Simultaneously, the cooling solution that removes heat from each of these components is also treated as an ETV. We show that the optimal system design can be determined through superposition of each of these ETVs with appropriately coupled boundary conditions. The resulting ETV representation of discretized heat sources and companioned cooling solutions essentially leads to the creation of an ETV network, which can then be optimized for the minimum sustainability footprint. We find that the optimal solution predicted by the exergo-thermo-volume approach matches those that would be predicted intuitively based on general design-for-environment and thermal management practices, but — using the current approach — we are also able to quantitatively show the difference between the optimal and sub-optimal choices. We conclude by demonstrating the applicability of the exergo-thermo-volume approach for the sustainable design of an enterprise server.
High-Accuracy Fatigue Evaluation of Power Devices by Multi-Coupled Analysis
Authors: Shinohara Kazunori , Yu Qiang , Anzawa Takashi , Ishii Hideaki
Published: January 2011

To calculate power semiconductor device fatigue with high accuracy, multiphysics analysis comprising electrical, heat, and stress analyses is presented. Power semiconductor devices (e.g., IGBTs) have been widely used in various applications. In particularly, the power semiconductor device (IGBT) becomes important component in vehicle applications. There is a high demand for compact and high-power capacity next-generation vehicles such as electric vehicles and hybrid vehicles. However, it causes the problem such as thermal stress. The reliability of power semiconductor devices has to be investigated by carrying out highly accurate simulations before developing IGBTs. In this paper, the electrical conductivity in silicon (IGBT) is considered as the material parameter. The semiconductor resistance is calculated by voltage distributions in the semiconductor. Comparing the conductivity constant case with the conductivity variation case, we examine the effects of the electrical characteristics of the semiconductor on fatigue.
Development of a New Wire Bonding Technology on Integrated Circuit Devices
Authors: Jiang Yingwei , Sun Ronglu , Wang Sonder , Zhang C. L. , Yu Youmin , Chen Weimin , Wei Xiao
Published: January 2011

In IC packaging, copper wire is generally regarded as a competent successor to gold wire due to many advantages in mechanical characteristics and cost efficiency. However, its known disadvantages restrict it to low-end integrated circuits as well. This paper discusses the development of a new wire bonding technology — copper ball on gold bump (COG) bonding in current wire bonders with both 1 mil copper and gold wires. It covers material and tool selection, wire bonding process window development, electrical characterization and reliability studies. The material and tool selection includes copper wire, experimental chip, capillary and wire bonder. Process window development focuses on two crucial stages, copper free air ball (FAB) formation and bonding process window development for both gold bump and copper ball bonded on Au bump. DOE approach is introduced into the relative process developments. The experimental studies reveal that flow rate of shielding gas is a key factor to obtain the qualified FAB formation and process window optimization for gold bump and copper ball on gold bump is more crucial to develop a successful COG bonding. Wire pull test, ball shear test and crater test are involved in the output measurement based on the criteria of JEDEC during the process window development. Package integrity and reliability performance with the COG bonding are fully assessed by performing electrical characterization and package internal delamination detection on the evaluated samples which have respectively undergone three reliability tests, High Temperature Baking, Temperature Cycle and Autoclave. The study result finally indicates that the COG bonding is a practicable approach to achieving copper wire application to high-end integrated circuits.
Thermo-Mechanical Reliability of Through Silicon Vias (TSVs) and Solder Interconnects in 3-Dimensional Integrated Circuits
Authors: Ladani Leila J. , Rodriguez Omar
Published: January 2011

3-dimensional integrated circuit (3D IC) is a promising technology in today’s IC packaging industry. Since the technology is in infancy stages, many aspects of this technology are still under heavy investigation. Reliability of through silicon via (TSV) interconnects and interlayer bonding between the silicon layers are issues that become more complicated in 3D ICs due to complexity of the architecture and miniaturized interconnects. Optimizing design of these devices is essential in order to avoid short fatigue life of interconnects. This manuscript addresses the impact of design parameters such as die thickness, TSV diameter, TSV pitch, underfill thickness and underfill properties on thermo-mechanical durability of Direct Chip Attach (DCA) solder joints and TSV interconnects used in a 3D IC packages. A design was proposed where DCA is used to connect 4 layers of ICs and TSVs are used to connect the active layer of the dies to the second silicon layer. Solder joints, as small as 50-micron diameter, were used to attach silicon layers. A numerical experiment is designed to vary design parameters at 3 levels using L9 ortagonal array. A 3-dimensional model of the package was built and model was solved under an accelerated temperature cycle loading. Solder is considered as visco-plastic material and copper interconnects are assumed to follow bilinear isotropic hardening behavior. Two continuum damage models, energy partitioning and Coffin-Manson models, were used to assess the number of cycles to failure for solder joints and TSV copper interconnects respectively. Minitab software was used to analyze the result of experiment. The most influential factors on durability of solder interconnect are found to be underfill properties and height. However, the most influential factor on TSV durability is found to be TSV diameter. A non-linear response was observed for TSV pitch and diameter indicating that the optimum level may be in the range selected.
Categorized Application Technology of Numerical Simulation on Electronic Equipment Thermal Design
Authors: Yokono Yasuyuki , Hisano Katsumi , Hirohata Kenji
Published: January 2011

In order to utilize a numerical simulation on a product development for electronic equipment, not only the simulation techniques themselves, but the application technologies of the simulation in the product design, were examined. The design process of electronic equipment was categorized into four stages, which were a concept, a function, a layout and a parameter design. Each design stage consists of a specifying that a human decide the specification for the next stage and a verification whether the specification satisfy the previous stage requirements. The specifying and the verification are conducted over and over again. Numerical simulation is corresponded to the verification and is used to accelerate this iteration instead of experiments. The examples of numerical simulation corresponding to these four verifications were shown in the present paper. There are few examples in last two type of simulation. The progress of the numerical technology for function and concept verification is expected. The product development process requires not only numerical simulation based on physics but also statistical approach.
Resonant Tunneling Peaks Appeared in the Current: Voltage Characteristics for Polymeric Thin Films
Authors: Tanaka Toshiaki , Sato Aiko , Asano Hitoshi , Takenaga Mitsuru
Published: January 2011

Current-voltage characteristics measured with conductive-atomic force microscopy for polymeric ultrathin films are examined. The polymeric films were prepared with uv-irradiation onto Langmuir-Blodgett films deposited two layers on glass or silicon substrates. The conjugated backbone chains with alkyl side-chains are regularly arranged on the substrate surface. Anomalous current peaks were observed for many samples; and appearance depends on the film structure and interfacial properties between molecules and electrodes. In addition, the steep increase in current occurred at higher applied voltages; values of the threshold electric field were estimated from Fowler-Nordheim plot. Furthermore the resistance between the electrodes decreased with increase in the effective film thickness.