bluuebunny/crossref_metadata_2025 huggingface dataset:
Detailed kinetic and chemometric study of the cellulose thermal breakdown in artificially aged and non aged commercial paper. Different methods for computing activation energy as an assessment model in archaeometric applications
Authors: Marini Federico , Tomassetti Mauro , Vecchio Stefano
Published: May 2012

Background

The thermal oxidative degradation of aged and non aged cellulose samples of commercial paper was studied using thermogravimetry and derivative thermogravimetry under a forced air flow up to 800°C.

Results

TG and DTG data were processed using two non-isothermal-based model-fitting methods and one based on linear least squares to calculate E
a trend values, measured as a function of artificially induced sample age. The E
a trends thus obtained were compared in order to assess their potential for yielding archaeometric curves. As the trends of first two methods show an inversion of the direction between non aged cellulose samples and artificially aged samples, while the third method does not, an in-depth study was carried out using a multilinearity assumption.

Conclusions

The results are discussed and the outcomes indicate that the above cited inversion is real and not linked to the method. Additionally, it was evidenced that the number of points used for the estimation of linear least squares model parameters is of capital importance.
Xanthogranuloma of the intrasellar region presenting in pituitary dysfunction: a case report
Authors: Nishiuchi Takamasa , Murao Koji , Imachi Hitomi , Kushida Yoshio , Haba Reiji , Kawai Nobuyuki , Tamiya Takashi , Ishida Toshihiko
Published: April 2012

Introduction

Differentiation of cystic mass lesions of the sellar and parasellar regions may pose a diagnostic dilemma for physicians, neurosurgeons, radiologists and pathologists involved in treating patients with these entities. A considerable number of tumors previously identified as craniopharyngiomas may, in fact, have been xanthogranulomas. We report a case of pituitary dysfunction caused by xanthogranuloma of the intrasellar region.

Case presentation

A 47-year-old man of Japanese descent presented to our institution with a tumor located exclusively in the intrasellar region which manifested as severe hypopituitarism. MRI revealed a clearly defined intrasellar mass that was heterogeneously hyperintense on T1-weighted images and markedly hypointense on T2-weighted images. We preoperatively diagnosed the patient with Rathke's cleft cyst or non-functioning pituitary adenoma. Although the tumor was completely removed using a transsphenoidal approach, the improvement of the patient's endocrine function was marginal, and continued endocrine replacement therapy was needed. Postoperatively, a histological examination revealed the tumor to be a xanthogranuloma of the intrasellar region. His visual field defects and headache improved.

Conclusion

Because diagnosis depends on surgical intervention and xanthogranulomas of the intrasellar region are very rare, the natural history of xanthogranuloma is still unknown. Therefore, this entity is difficult to diagnose preoperatively. We suggest that xanthogranuloma should be included in the differential diagnosis, even in the case of sellar lesions, to formulate appropriate postoperative management and improve endocrine outcomes.
Expression of Glut-1, HIF-1α, PI3K and p-Akt in a case of ceruminous adenoma
Authors: Shen Wan-Qin , Cheng Ke-Jia , Bao Yang-Yang , Zhou Shui-Hong , Yao Hong-Tian
Published: May 2012

Objectives

Ceruminous adenoma of the external auditory canal (EAC) is a rare type of tumour that is diagnosed histologically. However, the clinical behaviour of these tumours remains controversial. Here, we report a case of ceruminous adenoma of the EAC and expression of a hypoxia marker.

Case report

A 78-year-old man presented with a 6-month history of recurrent otorrhoea in the right ear. Surgery was performed by the transmeatal approach with total removal of the mass. Histopathology revealed a ceruminous adenoma. Tumour cells were positive for CK, S-100 protein, Glut-1, HIF-1α, PI3K and p-Akt. There was no evidence of recurrence at last follow-up 27 months after the operation.

Conclusions

Ceruminous adenoma of the EAC is a rare tumour. The treatment of choice is wide local excision with clear margins. To our knowledge, this is the first report of Glut-1 expression and the PI3K/Akt pathway in ceruminous adenoma of the EAC.
miR-206 integrates multiple components of differentiation pathways to control the transition from growth to differentiation in rhabdomyosarcoma cells
Authors: MacQuarrie Kyle L , Yao Zizhen , Young Janet M , Cao Yi , Tapscott Stephen J
Published: April 2012

Background

Similar to replicating myoblasts, many rhabdomyosarcoma cells express the myogenic determination gene MyoD. In contrast to myoblasts, rhabdomyosarcoma cells do not make the transition from a regulative growth phase to terminal differentiation. Previously we demonstrated that the forced expression of MyoD with its E-protein dimerization partner was sufficient to induce differentiation and suppress multiple growth-promoting genes, suggesting that the dimer was targeting a switch that regulated the transition from growth to differentiation. Our data also suggested that a balance between various inhibitory transcription factors and MyoD activity kept rhabdomyosarcomas trapped in a proliferative state.

Methods

Potential myogenic co-factors were tested for their ability to drive differentiation in rhabdomyosarcoma cell culture models, and their relation to MyoD activity determined through molecular biological experiments.

Results

Modulation of the transcription factors RUNX1 and ZNF238 can induce differentiation in rhabdomyosarcoma cells and their activity is integrated, at least in part, through the activation of miR-206, which acts as a genetic switch to transition the cell from a proliferative growth phase to differentiation. The inhibitory transcription factor MSC also plays a role in controlling miR-206, appearing to function by occluding a binding site for MyoD in the miR-206 promoter.

Conclusions

These findings support a network model composed of coupled regulatory circuits with miR-206 functioning as a switch regulating the transition from one stable state (growth) to another (differentiation).
Increase of leishmanicidal and tubercular activities using steroids linked to aminoquinoline
Authors: Antinarelli Luciana MR , Carmo Arturene ML , Pavan Fernando R , Leite Clarice Queico F , Da Silva Adilson D , Coimbra Elaine S , Salunke Deepak B
Published: May 2012

Background

Aminoquinoline/steroid conjugates were synthesized based on the fact that steroid transporters have been shown to accept and carry a variety of drugs. So, in continuing our research of antileishmanial and antitubercular drugs, aminoquinoline/steroid conjugates (12, 13, and 14) were regioselectively synthesized via 1, 3-dipolar cycloaddition of alkynes 3, 5, and 7 with azide 12. The aminoquinoline/steroids conjugates were evaluated in vitro against Leishmania major and Mycobacterium tuberculosis.

Results

Regioselective synthesis of the novel aminoquinoline/steroid conjugates was achieved in very high yield. All aminoquinoline/steroid conjugates (12, 13, and 14) exhibited best results against Leishmania and M. tuberculosis than the respective alkyne intermediate structures (3, 5, and 7, respectively). Among them, the compound 12 exhibited the best activity for M. tuberculosis (MIC = 8.8 μM). This result is comparable to drugs commonly used in tuberculosis treatment. Also, for antileishmanial assay, the aminoquinoline/steroid conjugates demonstrated a significant activity against promastigote and amastigote forms of L. major.

Conclusions

Addition of a steroid group to aminoquinoline molecules enhanced the leishmanicidal and antitubercular activities. These results highlight the importance of steroids as carrier.
Anti-type II collagen antibodies are associated with early radiographic destruction in rheumatoid arthritis
Authors: Mullazehi Mohammed , Wick Marius C , Klareskog Lars , van Vollenhoven Ronald , Rönnelid Johan
Published: May 2012

Introduction

We have previously reported that high levels of antibodies specific for native human type II collagen (anti-CII) at the time of RA diagnosis were associated with concurrent but not later signs of inflammation. This was associated with CII/anti-CII immune complex (IC)-induced production of pro-inflammatory cytokines in vitro. In contrast, anti-cyclic citrullinated peptide antibodies (anti-CCP) were associated both with late inflammation and late radiological destruction in the same RA cohort. We therefore hypothesized that anti-CII are also associated with early erosions.

Methods

Two-hundred-and-fifty-six patients from an early RA cohort were included. Baseline levels of anti-CII, anti-CCP and anti-mutated citrullinated vimentin were analyzed with ELISA, and rheumatoid factor levels were determined by nephelometry. Radiographs of hands and feet at baseline, after one and after two years were quantified using the 32-joints Larsen erosion score.

Results

Levels of anti-CII were bimodally distributed in the RA cohort, with a small (3.1%, 8/256) group of very high outliers with a median level 87 times higher than the median for the healthy control group. Using a cut-off discriminating the outlier group that was associated with anti-CII IC-induced production of proinflammatory cytokines in vitro, baseline anti-CII antibodies were significantly (p = 0.0486) associated with increased radiographic damage at the time of diagnosis. Anti-CII-positive patient had also significantly increased HAQ score (p = 0.0303), CRP (p = 0.0026) and ESR (p = 0.0396) at the time of diagnosis but not during follow-up. The median age among anti-CII-positive subjects was 12 years higher than among the anti-CII-negative patients.

Conclusion

In contrary to anti-CCP, anti-CII-positive patients with RA have increased joint destruction and HAQ score at baseline. Anti-CII thus characterizes an early inflammatory/destructive phenotype, in contrast to the late appearance of an inflammatory/destructive phenotype in anti-CCP positive RA patients. The anti-CII phenotype might account for part of the elderly acute onset RA phenotype with rather good prognosis.
New insights into the role and mechanism of macrophage migration inhibitory factor in steroid-resistant patients with systemic lupus erythematosus
Authors: Wang Fang-Fang , Zhu Li-An , Zou Yu-Qiong , Zheng Hui , Wilson Alisa , Yang Cheng-De , Shen Nan , Wallace Daniel J , Weisman Michael H , Chen Shun-Le , Lu Liang-Jing
Published: May 2012

Introduction

Glucocorticoid (GC) therapy remains important in improving the prognosis of patients with systemic lupus erythematosus (SLE). However, some patients do not achieve an effective response with GC treatment, creating an obstacle to the remission of SLE. Identification of the underlying mechanisms responsible for steroid resistance can be significant. Macrophage migration inhibitory factor (MIF) arouses our interest because of its reciprocal relationship with GCs. In the present study, we investigated for the first time whether MIF correlated with steroid resistance in SLE and explored potential mechanisms of action.

Methods

Sixty-two patients with SLE (40 steroid sensitive and 22 steroid resistant) and 21 normal controls were recruited. Serum levels of MIF were measured by ELISA. Cytosolic MIF and IκB expression in peripheral blood mononuclear cells (PBMCs) were determined by western blotting. The electrophoretic mobility shift assay was assessed by NF-κB in nuclear aliquots. Gene silencing was applied to reduce expression of MIF in PBMCs in steroid-resistant patients. PBMCs obtained from steroid-sensitive patients were treated with recombinant human MIF of different concentrations.

Results

MIF levels in serum and PBMCs were higher in steroid-resistant patients compared with steroid-sensitive patients and controls. In contrast to the steroid-sensitive group, NF-κB levels were significantly higher and IκB levels lower in steroid-resistant patients. After MIF gene silencing, IκB levels in cells from steroid-resistant patients were increased. In steroid-sensitive patients, a decrease in IκB levels and an increase in NF-κB expression from baseline were detected in PBMCs treated with a higher concentration of recombinant human MIF. Treatment with recombinant human MIF did not regulate expression of IκB and NF-κB in PBMCs from patients treated with an anti-MIF monoclonal antibody.

Conclusions

Our results indicated that MIF may play a role in the formation of steroid resistance in SLE by affecting the NF-κB/IκB signaling cascade. As a regulator of glucocorticoid sensitivity, MIF may be a potential target for steroid sparing.
Differential effect of CD69 targeting on bystander and antigen-specific T cell proliferation
Authors: Alari-Pahissa Elisenda , Vega-Ramos Javier , Zhang Jian-Guo , Castaño A Raúl , Turley Shannon J , Villadangos José A , Lauzurica Pilar
Published: April 2012

CD69 targeting induces bystander T cell proliferation but does not affect antigen-specific proliferation.

In spite of an initially proposed role as a costimulatory molecule for CD69, in vivo studies showed it as a regulator of immune responses and lymphocyte egress. We found constitutive CD69 expression by T cell subsets and pDC. We examined a possible effect of CD69 on T cell proliferation using transfer models and in vitro assays. In mice locally expressing or receiving antigen, anti-CD692.2 treatment did not affect the proliferation of antigen-specific transgenic T cells in ADLN, although we observed the presence of proliferated T cells in non-ADLN and spleen. This was not affected by FTY720 treatment and thus, not contributed by increased egress of proliferated lymphocytes from ADLN. In the absence of antigen, anti-CD69 2.2 treatment induced bystander proliferation of transferred memory phenotype T cells. This proliferation was mediated by IL-2, as it was inhibited by anti-IL-2 or anti-CD25 antibodies in vitro and by anti-CD25 antibodies in vivo. It was also dependent on CD69 expression by donor T cells and recipient cells. CD69 targeting on T cells enhanced IL-2-mediated proliferation and CD25 expression. However, it did not lead to increased early IL-2 production by T cells. No T cell subset was found to be specifically required in the recipient. Instead, CD69 targeting on pDC induced their expression of IL-2 and CD25, and pDC depletion showed that this subset was involved in the proliferation induction. These results indicate that CD69 targeting induces bystander T cell proliferation through pDC IL-2 production and T cell sensitization to IL-2 without affecting antigen-driven T cell proliferation.
Regulation of alveolar macrophage p40phox: hierarchy of activating kinases and their inhibition by PGE2
Authors: Bourdonnay Emilie , Serezani Carlos H , Aronoff David M , Peters-Golden Marc
Published: April 2012

In lung macrophages, inhibition of p40phox by PGE2 represents a brake on bacterial killing, and likely contributes to impaired lung innate immunity.

PGE2, produced in the lung during infection with microbes such as Klebsiella pneumoniae, inhibits alveolar macrophage (AM) antimicrobial functions by preventing H2O2 production by NADPH oxidase (NADPHox). Activation of the NADPHox complex is poorly understood in AMs, although in neutrophils it is known to be mediated by kinases including PI3K/Akt, protein kinase C (PKC) δ, p21-activated protein kinase (PAK), casein kinase 2 (CK2), and MAPKs. The p40phox cytosolic subunit of NADPHox has been recently recognized to function as a carrier protein for other subunits and a positive regulator of oxidase activation, a role previously considered unique to another subunit, p47phox. The regulation of p40phox remains poorly understood, and the effect of PGE2 on its activation is completely undefined. We addressed these issues in rat AMs activated with IgG-opsonized K. pneumoniae. The kinetics of kinase activation and the consequences of kinase inhibition and silencing revealed a critical role for a PKCδ-PAK-class I PI3K/Akt1 cascade in the regulation of p40phox activation upon bacterial challenge in AMs; PKCα, ERK, and CK2 were not involved. PGE2 inhibited the activation of p40phox, and its effects were mediated by protein kinase A type II, were independent of interactions with anchoring proteins, and were directed at the distal class I PI3K/Akt1 activation step. Defining the kinases that control AM p40phox activation and that are the targets for inhibition by PGE2 provides new insights into immunoregulation in the infected lung.
Direct in vivo evidence of CD4+ T cell requirement for CTL response and memory via pMHC-I targeting and CD40L signaling
Authors: Ahmed Khawaja Ashfaque , Wang Lu , Munegowda Manjunatha Ankathatti , Mulligan Sean J , Gordon John R , Griebel Philip , Xiang Jim
Published: April 2012

New in vivo evidence of CD4+ T cells capable of directly stimulating effective CTL response.

CD4+ T cell help contributes critically to DC-induced CD8+ CTL immunity. However, precisely how these three cell populations interact and how CD4+ T cell signals are delivered to CD8+ T cells in vivo have been unclear. In this study, we developed a novel, two-step approach, wherein CD4+ T cells and antigen-presenting DCs productively engaged one another in vivo in the absence of cognate CD8+ T cells, after which, we selectively depleted the previously engaged CD4+ T cells or DCs before allowing interactions of either population alone with naïve CD8+ T cells. This protocol thus allows us to clearly document the importance of CD4+ T-licensed DCs and DC-primed CD4+ T cells in CTL immunity. Here, we provide direct in vivo evidence that primed CD4+ T cells or licensed DCs can stimulate CTL response and memory, independent of DC-CD4+ T cell clusters. Our results suggest that primed CD4+ T cells with acquired pMHC-I from DCs represent crucial “immune intermediates” for rapid induction of CTL responses and for functional memory via CD40L signaling. Importantly, intravital, two-photon microscopy elegantly provide unequivocal in vivo evidence for direct CD4-CD8+ T cell interactions via pMHC-I engagement. This study corroborates the coexistence of direct and indirect mechanisms of T cell help for a CTL response in noninflammatory situations. These data suggest a new “dynamic model of three-cell interactions” for CTL immunity derived from stimulation by dissociated, licensed DCs, primed CD4+ T cells, and DC-CD4+ T cell clusters and may have significant implications for autoimmunity and vaccine design.
Successful exclusion of a large bronchopleural fistula using an Amplatzer II vascular plug and glue embolization
Authors: Spiliopoulos Stavros , Krokidis Miltiadis , Gkoutzios Panagiotis , McGrath Andrew , Ahmed Irfan , Karunanithy Narayan , Routledge Tom , Sabharwal Tarun , Adam Andreas
Published: May 2012

We report a case of a 63-year-old man with a complicated postsurgical bronchopleural fistula (BPF), which was treated with a minimally-invasive hybrid procedure using fluoroscopy, bronchoscopy, and thoracoscopy. A previous surgical attempt had failed to seal the pathologic tract. An Amplazter II vascular plug was successfully deployed into the BPF, followed by autologous blood and glue injection. An adjunctive endoscopically-guided glue embolization was deemed necessary. The 14-month clinical and imaging follow-up confirmed the successful exclusion of the BPF. No migration of the device was noted and the patient remained asymptomatic. The combined endoscopic and fluoroscopic guided management of a BPF using the Amplatzer II vascular plug and glue was proven safe and effective after mid-term follow-up.
Dynamic Pricing with Financial Milestones: Feedback-Form Policies
Authors: Besbes Omar , Maglaras Costis
Published: April 2012

We study a seller that starts with an initial inventory of goods, has a target horizon over which to sell the goods, and is subject to a set of financial milestone constraints on the revenues and sales that need to be achieved at different time points along the sales horizon. We characterize the revenue maximizing dynamic pricing policy for the seller and highlight the effect of revenue and sales milestones on its structure. The optimal policy can be written in feedback form, where the price at each point in time is selected so as to track the most stringent among all future milestones. Building on that observation, we propose a discrete-review policy that aims to dynamically track the appropriate milestone constraint and show that this simple and practical policy is near optimal in settings with large initial capacity and long sales horizons even in settings with no advance demand model information. One motivating application comes from the sales of new multiunit, residential real estate developments, where intermediate milestone constraints play an important role in their financing and construction.

This paper was accepted by Gérard P. Cachon, stochastic models and simulation.
Psychological Pressure in Competitive Environments: New Evidence from Randomized Natural Experiments
Authors: Kocher Martin G. , Lenz Marc V. , Sutter Matthias
Published: April 2012

Dynamic competitive settings may create psychological pressure when feedback about the performance of competitors is provided before the end of the competition. Such psychological pressure could produce a first-mover advantage, despite a priori equal winning probabilities. Using data from a randomized natural experiment—penalty shootouts in soccer—we reexamine evidence by Apesteguia and Palacios-Huerta [Apesteguia J, Palacios-Huerta I (2010) Psychological pressure in competitive environments: Evidence from a randomized natural experiment. Amer. Econom. Rev. 100(5):2548–2564]. They report a 21-percentage-point advantage for first movers over second movers in terms of winning probabilities. Extending their sample of 129 shootouts to 540, we fail to detect any significant first-mover advantage. Our results are fully consistent with recent evidence from other sports contests.

This paper was accepted by Teck Ho, behavioral economics.
Consumer Valuation of Modularly Upgradeable Products
Authors: Ülkü Sezer , Dimofte Claudiu V. , Schmidt Glen M.
Published: April 2012

Although product modularity is often advocated as a design strategy in the operations management literature, little is known about how consumers respond to modular products. In this research we undertake several experiments to explore consumer response to modularly upgradeable products in settings featuring technological change. We consider both the initial product choice (between a modularly upgradeable product and an integral one) and the subsequent upgrade decision (replacement of a module versus full product replacement). First, we show that consumers tend to discount the cost savings associated with modular upgrades excessively (insufficiently) when the time between the initial purchase and the upgrade is short (long). This suggests that modular upgradability as a product feature has higher profit potential for slowly rather than rapidly improving products. Second, we observe a preference reversal between the initial purchase and the point of upgrade: At the point of initial purchase, people foresee making a full product replacement in the future, yet, when faced with the actual upgrade decision, they are more likely to revert to modular upgrades. Finally, we discuss and test several pricing and product design strategies that the firm can use to respond to these cognitive biases.

This paper was accepted by Kamalini Ramdas, entrepreneurship and innovation.
Contingent Capital with a Capital-Ratio Trigger
Authors: Glasserman Paul , Nouri Behzad
Published: April 2012

Contingent capital in the form of debt that converts to equity when a bank faces financial distress has been proposed as a mechanism to enhance financial stability and avoid costly government rescues. Specific proposals vary in their choice of conversion trigger and conversion mechanism. We analyze the case of contingent capital with a capital-ratio trigger and partial and ongoing conversion. The capital ratio we use is based on accounting or book values to approximate the regulatory ratios that determine capital requirements for banks. The conversion process is partial and ongoing in the sense that each time a bank's capital ratio reaches the minimum threshold, just enough debt is converted to equity to meet the capital requirement, so long as the contingent capital has not been depleted. We derive closed-form expressions for the market value of such securities when the firm's asset value is modeled as geometric Brownian motion, and from these we get formulas for the fair yield spread on the convertible debt. A key step in the analysis is an explicit expression for the fraction of equity held by the original shareholders and the fraction held by converted investors in the contingent capital.

This paper was accepted by Gérard P. Cachon, stochastic models and simulation.
Asset Pricing Restrictions on Predictability: Frictions Matter
Authors: de Roon Frans , Szymanowska Marta
Published: April 2012

U.S. stock portfolios sorted on size; momentum; transaction costs; market-to-book, investment-to-assets, and return-on-assets (ROA) ratios; and industry classification show considerable levels and variation of return predictability, inconsistent with asset pricing models. This means that a predictable risk premium is not equal to compensation for systematic risk as implied by asset pricing theory. We show that introducing market frictions relaxes these asset pricing moments from a strict equality to a range. Empirically, it is not short sales constraints but transaction costs (below 35 basis points) that help to reconcile the observed predictability with linear portfolio return-based factor models, and partly with the durable consumption model. Across the sorts, predictability in industry returns can be reconciled with all models considered with only a 25 basis point transaction cost, whereas for momentum and ROA portfolios, up to 115 basis points are needed.

This paper was accepted by Wei Xiong, finance.
A Field Investigation of Multilevel Cynicism Toward Change
Authors: DeCelles Katherine A. , Tesluk Paul E. , Taxman Faye S.
Published: April 2012

Although most research on cynicism toward change (CTC) has been conceptualized at the individual level, we propose that CTC is better conceptualized as a multilevel phenomenon, acting as both an employee attitude and an organizational climate. We conducted a multilevel investigation of CTC in a field sample of 687 correctional officers in the 14 prisons in a state penal system. Consistent with our hypotheses, both employee CTC and CTC climate uniquely predicted negative employee attitudes and behaviors directed at the organization. Offering insight into how to address CTC, we found that transformational leadership negatively relates to employee CTC and CTC climate. Our results highlight the importance of studying CTC in organizations from a multilevel perspective and suggest that transformational leadership is significant for supporting both functional employee attitudes and a facilitative climate toward organizational change.
Dual Signals: How Competition Makes or Breaks Interfirm Social Ties
Authors: Trapido Denis
Published: April 2012

Research has documented the benefits of social ties across boundaries of competing firms but has not specified when competition enables such ties or when it damages them. Ninety semistructured interviews sought to elicit answers to this question from leaders of drug development companies in the San Francisco Bay Area. The informants reported withholding social ties from counterparts in competing companies if these companies affirmed to them the goal conflict aspect of the competition relation; they reported social connectedness to individuals in competing companies if these companies affirmed to them joint professional affiliation, the other necessary aspect of competition. Unique quantitative data on competition and social relations in the Bay Area's drug development industry confirmed this pattern for weak social ties (acquaintance). Strong social ties (friendship) were not affected by any examined organizational or interorganizational factors.
Looking Inside the Dream Team: Probing Into the Contributions of Tacit Knowledge as an Organizational Resource
Authors: Shamsie Jamal , Mannor Michael J.
Published: April 2012

Despite growing evidence that suggests that tacit knowledge can serve as a critical resource, there has been little effort to understand how such a form of personalized knowledge can provide strong advantages to an entire group or organization. In this paper, we develop four different categories of tacit knowledge that are derived from the basic tenants of the resource-based framework. More specifically, we distinguish between the discrete and linked forms of productive tacit knowledge that is possessed by individuals and administrative tacit knowledge that is held by managers within an organization. Next, we evaluate the role of each of these four different forms of tacit knowledge by focusing on the contribution of players and managers of professional sports teams. Our analysis of a large sample of Major League Baseball teams from 1985 to 2001 provides significant support for the importance of each of these categories of tacit knowledge for the performance of an organization.
Competition and Cooperation in Corporate Governance: The Effects of Labor Institutions on Blockholder Effectiveness in 23 European Countries
Authors: van Essen Marc , van Oosterhout J. (Hans) , Heugens Pursey P. M. A. R.
Published: April 2012

We provide an analysis of the costs and benefits of blockholding in Europe, where it is a dominant, but certainly not universal, corporate governance strategy for shareholders of publicly listed firms. We find that the effectiveness of blockholding is conditioned by the specific labor institutions that distinguish European countries from the rest of the world, and that these institutional effects involve both competition and cooperation between blockholders and collective labor interests. We also find that relational blockholders are better able to cope with, or benefit from, these institutional effects than arm's-length blockholders. Empirically, we use advanced meta-analytic methods on a total sample of 748,569 firm-year observations, derived from 162 studies covering 23 European countries.
Designing for Complexity: Using Divisions and Hierarchy to Manage Complex Tasks
Authors: Zhou Yue Maggie
Published: April 2012

This paper studies the impact of task complexity and decomposability on the degree of organizational divisionalization and hierarchy within firms. Drawing upon the team theory and modularity literature, it argues that the degree of divisionalization is predicated not only on the extent of interdependence (complexity) among tasks but also on the extent to which those interdependent relationships are decomposable. As such, the feasibility and benefits of modularization in organizational design may be overstated when the underlying tasks are not decomposable. In addition, this paper argues that organizational hierarchy serves to mitigate the tension between complexity and decomposability by facilitating a higher degree of divisionalization. These arguments are tested using data on the business activities and organization structures of U.S. equipment manufacturers in 1993–2003. Results show that divisionalization increases with task complexity, suggesting that complex task systems encourage more division of managerial responsibilities. However, divisionalization decreases as task systems become less decomposable. Meanwhile, organizational hierarchy increases with task complexity, and it increases as task systems become less decomposable. These findings highlight the constraints firms face in designing modular organization structures and the role of hierarchy in coordinating complex task systems that are not fully decomposable.
Seizing Opportunity in Emerging Fields: How Institutional Entrepreneurs Legitimated the Professional Form of Management Consulting
Authors: David Robert J. , Sine Wesley D. , Haveman Heather A.
Published: April 2012

We draw on the early history of the management consulting field to build theory about how institutional entrepreneurs legitimate new kinds of organizations in emerging fields. We study the professional form of management consulting organization, which came to dominate other alternatives. Pioneers of this organizational form seized opportunities arising from broad institutional change to discredit the status quo and legitimate their model of how to advise organizations on strategic and operational issues. Similar to institutional entrepreneurs seeking to change mature fields, those in this emerging field engaged in theorization, undertook collective action, and established affiliations with recognized authorities and elites. But unlike institutional entrepreneurs in mature fields, the actors we studied could not leverage logics, positions, or collectivities within their emerging field; instead, they drew on logics from outside their field, sought affiliations with external authorities and elites, and emphasized the benefits of their activities for society at large. Our analysis thus suggests important differences in how actors legitimate novel organizational forms in emerging versus mature fields and underscores the need for theories of institutional entrepreneurship that explicitly account for field context.
Learning, Imitation, and the Use of Knowledge: A Comparison of Markets, Hierarchies, and Teams
Authors: Butler John C. , Grahovac Jovan
Published: April 2012

We use computer simulation to study how different allocations of decision rights give rise to different organizational abilities to maintain and act upon accurate maps of a changing environment. We compare the performance of three archetypal organizational forms as we vary the dynamism and complexity of the environment and the rates at which individuals can observe the environment and imitate each other. We find that teams in which actions are based on plurality votes excel when the task is relatively easy—that is, the ability of individual members to observe the environment is high compared to the environment's dynamism and size. Markets in which all agents act independently perform well when the task is difficult and the agents can easily imitate each other. Hierarchies in which agents in the upper echelons impose actions on their subordinates outperform the other two forms when the agents' abilities to observe the environment are heterogeneous, the task is difficult, and imitation among the agents is moderate. The analysis has implications for the relationship between centralization and the notions of exploitation and exploration in March's influential work [March JG (1991) Exploration and exploitation in organizational learning. Organ. Sci. 2(1):71–87].
Cost-Effectiveness of Adjunctive Therapy with Atypical Antipsychotics for Acute Treatment of Major Depressive Disorder
Authors: Taneja Charu , Papakostas George I , Jing Yonghua , Baker Ross A , Forbes Robert A , Oster Gerry
Published: May 2012

Background:

While the clinical utility of atypical antipsychotics has been established in patients with major depressive disorder (MDD) who are refractory to antidepressant therapy, their cost-effectiveness is unknown.

Objective:

To examine the cost-effectiveness of aripiprazole, quetiapine, and olanzapine/fluoxetine in adults with MDD who are refractory to antidepressant therapy.

Methods:

Using techniques of decision analysis, we estimated expected outcomes and costs over 6 weeks in adults with MDD receiving (1) aripiprazole 2-20 mg/day and antidepressant therapy; (2) quetiapine 150 mg/day or 300 mg/day and antidepressant therapy; (3) the fixed-dose combination of olanzapine 6, 12, or 18 mg/day with fluoxetine 50 mg/day; or (4) antidepressant therapy alone. Cost-effectiveness was assessed in terms of the cost per additional responder at 6 weeks, defined as the ratio of the difference in the cost of MDD-related care over 6 weeks versus antidepressant therapy afone to the difference in the number of patients achieving clinical response by 6 weeks. We estimated the model using data from Phase 3 clinical trials of atypical antipsychotics along with other secondary data sources.

Results:

With antidepressant therapy alone, the estimated clinical response rate at 6 weeks was 30%. Aripiprazole, quetiapine 150 mg/day, quetiapine 300 mg/day, and olanzapine/fluoxetine were estimated to increase clinical response at 6 weeks to 49%, 34%, 38%, and 45%. respectively. Costs of MDD-related care over 6 weeks were estimated to be $192 for antidepressant therapy, $847 for aripiprazole, $541 for quetiapine 150 mg/day, $672 for quetiapine 300 mg/day plus antidepressant therapy, and $791 for olanzapine/fluoxetine. Costs per additional responder (vs antidepressant therapy) over a 6-week period were estimated to be $3447 for aripiprazole, $8725 for quetiapine 150 mg/day, $6000 for quetiapine 300 mg/day, and $3993 for olanzapine/fluoxetine.

Conclusions:

Atypical antipsychotics substantially increase clinical response at 6 weeks. Cost per additional responder is lower for aripiprazole than for quetiapine or olanzapine/fluoxetine.
Antihypertensive Drugs in Patients Treated with Antiretroviral
Authors: Peyriere Hélène , Eiden Céline , Macia Jean-Christophe , Reynes Jacques
Published: May 2012

Objective:

To review the literature for information regarding pharmacokinetic interactions between antiretrovirals and antihypertensive agents, evaluate the clinical significance of these interactions, and analyze the effect of antihypertensive drugs on the metabolic complications frequently observed in HIV-infected patients to emphasize the advantages and inconveniences of every class of antihypertensive drugs in association with antiretrovirals.

Data Sources:

A literature search was conducted via PubMed and MEDLINE (1950-November 2011) using the search terms drug interactions, cytochrome P450, names of antiretrovirals, names of commonly prescribed antihypertensive drugs, pharmacokinetics, and metabolic complications. Reference citations from relevant publications, manufacturers’ product information, and www.HIV-druginteracttons.org were also reviewed.

Study Selection And Data Extractions:

All articles with an English abstract identified through the data search were examined. Of these, pharmacologic reviews, studies, and case reports were evaluated.

Data Synthesis:

Antihypertensive drugs interact with several antiretroviral drugs, non nucleoside reverse transcriptase inhibitors (NNRTIs) and protease inhibitors (Pls) in particular. Pharmacokinetic interactions are less expected with diuretics, jî-blockers excreted by the kidney, angiotensin-converting enzyme (ACE) inhibitors, and angiotensin II receptor blockers (ARBs) other than losartan and irbesartan. Calcium channel blockers (CCBs) are metabolized by CYP3A4, with the potential for interaction with NNRTIs and Pls. Because CCBs do not adversely affect glucose or lipid metabolism or renal function, they may be preferred in patients with such complications. ACE inhibitors and ARBs may exert favorable effects on glucose homeostasis. In addition, they may significantly reduce protein excretion and further slow the progression of renal disease.

Conclusions:

The choice of antihypertensive drugs in HIV-infected patients is complex and must take into account the metabolic pathways of antiretroviral drugs and antihypertensive drugs with the potential of pharmacokinetic interactions, as well as the effect of antihypertensive drugs on some biological parameters.
Perceptions of Communication Choice and Usage Among African American Hearing Parents: Afrocentric Cultural Implications for African American Deaf and Hard of Hearing Children
Authors: Borum Valerie
Published: April 2012

In a qualitative study employing an exploratory design, the researcher explored the perceptions of communication choice and usage among 14 African American hearing parents of deaf and hard of hearing children. Semistructured, in-depth thematic interviews were used with a modified grounded-theory approach in which themes were analyzed and coded. Four thematic challenges and opportunities related to communication choice and usage were found: (a) oral tradition— nommo , (b) sign and oral— diunital , (c) literacy, and (d) racial/ethnic cultural socialization. Afrocentric implications for deaf and hard of hearing children are explored based on research observations pertaining to the significance of the oral tradition in African American culture and the socialization of African American deaf and hard of hearing children in the context of African American hearing families.
Young Deafblind Adults in Action: Becoming Self-Determined Change Agents Through Advocacy
Authors: Bruce Susan M. , Parker Amy T.
Published: April 2012

Six young deafblind adults took a 1-week course on civic engagement and advocacy, which provided the focus for a participatory action research study with a collective case study design. They selected advocacy topics, were briefed on these policy issues, and were paired with experienced mentors for meetings with legislators in Washington, DC. Eight themes were identified from constant comparative and in vivo analysis of classroom discussion notes, interviews, and journals: (a) defining advocacy and advocate , (b) rights and equality, (c) expectations, (d) role of education in change, (e) deafblind expertise, (f) characteristics of effective change agents, (g) advocacy is teamwork, (h) future advocacy. In the classroom, the participants learned about policy issues, communication considerations, and leadership, then applied this knowledge in the legislative arena. Through the advocacy process, they learned to apply their personal strengths as advocates and experienced the importance of teamwork in advocacy.
Health Information Needs of D/Deaf Adolescent Females: A Call to Action
Authors: Smith Chad E. , Massey-Stokes Marilyn , Lieberth Ann
Published: April 2012

Adolescent Health and health literacy are critical health topics recognized in Healthy People 2020. Evidence indicates that adolescents who are d/Deaf have unique health-related needs, yet health communication efforts have not reached them. Despite the Internet's exponential growth and the growth of online health information-seeking behavior among adolescents, reliable information devoted specifically to d/Deaf adolescents who communicate primarily in ASL is rare. D/deaf adolescent females face numerous challenges accessing web-based health information to enhance their decision making about important health issues such as body image, physical activity and nutrition, puberty, and relationships. A strong need exists for interdisciplinary professionals to investigate the health interests and online health information-seeking behaviors of this group in order to effectively plan, implement, and evaluate a web-based health repository that delivers content in ASL. This Call to Action represents a first step in addressing that need.
Parallel and Divergent Interpreting in an Elementary School Classroom
Authors: Wolbers Kimberly A. , Dimling Lisa M. , Lawson Heather R. , Golos Debbie B.
Published: April 2012

The study examined the extent to which a highly qualified interpreter remained parallel with or diverged from the original classroom discourse in her interpreting for a 3rd-grade deaf student in science, social studies, and resource room. The interpreter's signed and verbalized expressions were compared to the class participants' expressions for meaning equivalence. Parallel interpreting, occurring 33.2% of the time, closely matched the content of the speaker's message. Divergent interpreting, whereby the interpreter added or dropped elements of meaning, occurred 66.8% of the time. Qualitative analyses of classroom footage as well as interviews with the interpreter and the teachers revealed how, when, and why the interpreter diverged from the message. While the interpreter often made intentional reductions and additions to the discourse to achieve greater student understanding of language and course content, there was little awareness of these changes among individualized educational program team members.
The Impact of Verbal Capacity on Theory of Mind in Deaf and Hard of Hearing Children
Authors: Levrez Clovis , Bourdin Béatrice , Le Driant Barbara , D'Arc Baudouin Forgeot , Vandromme Luc
Published: April 2012

Even when they have good language skills, many children with hearing loss lag several years behind hearing children in the ability to grasp beliefs of others. The researchers sought to determine whether this lag results from difficulty with the verbal demands of tasks or from conceptual delays. The researchers related children's performance on a nonverbal theory of mind task to their scores on verbal aptitude tests. Twelve French children (average age about 10 years) with severe to profound hearing loss and 12 French hearing children (average about 7 years) were evaluated. The children with hearing loss showed persistent difficulty with theory of mind tasks, even a nonverbal task, presenting results similar to those of hearing 6-year-olds. Also, the children with hearing loss showed a correlation between language level (lexical and morphosyntactic) and understanding of false beliefs. No such correlation was found in the hearing children.
States' Reading Outcomes of Students Who Are d/Deaf and Hard of Hearing
Authors: Easterbrooks Susan R. , Beal-Alvarez Jennifer S.
Published: April 2012

Historically, researchers have identified that reading outcomes for students in upper grades who are d/Deaf and hard of hearing (d/Dhh) have typically rested around the late 3rd to early 4th grade. In recent years, wide-scale state-level testing has called into question these prognostications. The authors conducted a descriptive, multiunit, embedded-designs case study of 7 states' data from multiyear annual assessments of reading of participants in grades 3, 5, and 8, and in high school. Participants, states' definitions of reading outcomes, and states' reported reading results are described. The authors, who found that many students are reading at levels above the perceived 3rd-to-4th-grade "glass ceiling," build the case for a more hopeful look at reading outcomes for these students than that of the past and recommend approaches for acquiring wide-scale data that will allow professionals in the field to better understand reading outcomes in this population.
Anti-luck Epistemology, Pragmatic Encroachment, and True Belief
Authors: Ballantyne Nathan
Published: April 2012

Two common theses in contemporary epistemology are that ‘knowledge excludes luck’ and that knowledge depends on ‘purely epistemic’ factors. In this essay, I shall argue as follows: given some plausible assumptions, ‘anti-luck epistemology,’ which is committed to the fi rst thesis, implies the falsity of the second thesis. That is, I will argue that anti-luck epistemology leads to what has been called ‘pragmatic encroachment’ on knowledge. Anti-luck epistemologists hoping to resist encroachment must accept a controversial thesis about true beliefora dubious claim about luck and value and interests.