889 research outputs found
Identity asymmetries:An experimental investigation of social identity and information exchange in multiteam systems
Many complex organizational tasks are performed by networks of teams, or “multiteam systems.” A critical challenge in multiteam systems is how to promote information exchange across teams. In three studies, we investigate how identity “asymmetries”—differences between teams in terms of whether the team or overarching system constitutes their primary focus of identification—affect interteam information sharing and performance. In Study 1, we manipulate teams’ foci of identification (team vs. system focused) in a sample of 84 five-member teams working in one of 21 four-team multiteam systems performing a computer strategy simulation. We find that, while system-focused teams shared information equally with all teams, team-focused teams shared less information with system-focused teams than they did with other team-focused teams. Interteam information sharing positively predicted interteam performance. In Study 2, we test the assumptions underlying our theory in a vignette experiment, demonstrating that team-focused individuals adopt instrumental motives toward interteam interaction. Finally, in Study 3, we investigate the implications of system composition in terms of team identity foci by means of a simulation study based on the empirical results of Study 1. The results of the simulation yield novel propositions about the nonlinear effects of social identity in multiteam systems
Origin and outcome of metastatic tumours to the testes:a nationwide study
ObjectivesTo perform a retrospective cohort analysis for metastatic tumours in the testes to explore the timing, presentation and prognosis of this particular type of metastases and the factors that influence outcome.Patients and methodsA nationwide retrospective review of pathology reports of patients with pathologically confirmed metastases to the testis between 1991 and 2021 was performed. Data were collected from the Dutch nationwide pathology databank (PALGA) and the Netherlands Cancer Registry. Log-rank testing and Kaplan–Meier analyses were used to assess overall survival (OS), and Cox proportional hazard models were used for multivariate survival analysis.ResultsA total of 175 patients with a testicular metastasis were included. The median (range) age at diagnosis of testicular metastasis was 67 (3–88) years. Testicular metastases originated from a variety of primary tumours, although most frequently from the prostate (40.6%), kidney (13.7%), colon (10.3%), bladder (7.4%) and skin (5.7%). Synchronous testicular metastasis was detected in 53 cases, while 114 metachronous lesions were found after a median (interquartile range) interval of 22 (1–53) months after the original cancer diagnosis. OS after the diagnosis of a testicular metastasis was poor, with a median survival of 14.2 months (95% confidence interval 10.2–18.3). Primary tumour origin was an independent factor for survival, with worst survival for patients with primary skin, bladder and colon cancer.ConclusionTesticular metastases are very uncommon and arise mainly from primary tumours anatomically close to the testes. Most patients develop metachronous testicular metastasis at an oligometastatic disease stage. These metastases are invariably associated with poor survival
History matters: The impact of reviews and sales of earlier versions of a product on consumer and expert reviews of new editions
Product reviews are assumed to be based on the observable characteristics of the underlying product. However, in the case of new editions in a product series, the determinants may include signals that originate from the reviews and the sales of editions that precede the focal product edition. Our analysis of 577 video games released in a series between 2000 and 2009 indicates that the reviews of earlier versions carry over to the reviews of the sequel by the same type of reviewer. We also find that expert reviews are influenced by the average review of previous editions by consumers and the average sales of previous editions of the product. This suggests that experts tend to adapt to the taste of consumers. Furthermore, it is found that a lack of consensus, between reviewers of a particular type, weakens the impact of average past reviews, whilst it magnifies the impact of the sales of earlier versions
Muscle co-activity tuning in Parkinsonian hand movement : disease-specific changes at behavioral and cerebral level
We investigated different degrees of muscle co-activity in simple hand movement at behavioral and cerebral level in healthy subjects and Parkinson’s disease (PD) patients. We compared 'singular' movements, dominated by the activity of one agonist muscle, to 'composite' movements, requiring conjoint activity of multiple muscles, in a center-out (right hand) step-tracking task. Behavioral parameters were obtained by EMG and kinematic recordings. fMRI was used to investigate differences in underlying brain activations between PD patients (N= 12) and healthy (age-matched) subjects (N= 18). In healthy subjects, composite movements recruited the striatum and cortical areas comprising bilaterally the supplementary motor area and premotor cortex, contralateral medial prefrontal cortex, primary motor cortex, primary visual cortex, and ipsilateral superior parietal cortex. Contrarily, the ipsilateral cerebellum was more involved in singular movements. This striking dichotomy between striatal and cortical recruitment versus cerebellar involvement may reflect the complementary roles of these areas in motor control, in which the basal ganglia are involved in movement selection and the cerebellum in movement optimization. Compared to healthy subjects, PD patients showed decreased activation of the striatum and cortical areas in composite movement, while performing worse at behavioral level. This implies that PD patients are especially impaired on tasks requiring highly tuned muscle co-activity. Singular movement, on the other hand, was characterized by a combination of increased activation of the ipsilateral parietal cortex and left cerebellum. As singular movement performance was only slightly compromised, we interpret this as a reflection of increased visuospatial processing, possibly as a compensational mechanism
In Vivo Imaging of Vesicular Monoamine Transporters in Human Brain Using [ 11 C]Tetrabenazine and Positron Emission Tomography
The pharmacokinetics of [ 11 CJtetrabenazine, a high-affinity radioligand for the monoamine vesicular transporter, were determined in living human brain using in vivo imaging by positron emission tomography (PET). The radiotracer showed high brain uptake and rapid washout from all brain regions with relatively slower clearance from regions of highest concentrations of monoamine vesicular transporters (striatum), resulting in clear differential visualization of these structures at short intervals after injection (10–20 min). As the first human PET imaging study of a vesicular neurotransmitter transporter, these experiments demonstrate that external imaging of vesicular transporters forms a new and valuable approach to the in vivo quantification of monoaminergic neurons, with potential application to the in vivo study of neurodegenerative disorders such as Parkinson's disease.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65743/1/j.1471-4159.1993.tb03521.x.pd
A Relational Event Approach to Modeling Behavioral Dynamics
This chapter provides an introduction to the analysis of relational event
data (i.e., actions, interactions, or other events involving multiple actors
that occur over time) within the R/statnet platform. We begin by reviewing the
basics of relational event modeling, with an emphasis on models with piecewise
constant hazards. We then discuss estimation for dyadic and more general
relational event models using the relevent package, with an emphasis on
hands-on applications of the methods and interpretation of results. Statnet is
a collection of packages for the R statistical computing system that supports
the representation, manipulation, visualization, modeling, simulation, and
analysis of relational data. Statnet packages are contributed by a team of
volunteer developers, and are made freely available under the GNU Public
License. These packages are written for the R statistical computing
environment, and can be used with any computing platform that supports R
(including Windows, Linux, and Mac).
Oxidative stress leads to beta-cell dysfunction through loss of beta-cell identity
Pancreatic beta-cell failure is a critical event in the onset of both main types of diabetes mellitus but underlying mechanisms are not fully understood. beta-cells have low anti-oxidant capacity, making them more susceptible to oxidative stress. In type 1 diabetes (T1D), reactive oxygen species (ROS) are associated with pro-inflammatory conditions at the onset of the disease. Here, we investigated the effects of hydrogen peroxide-induced oxidative stress on human beta-cells. We show that primary human beta-cell function is decreased. This reduced function is associated with an ER stress response and the shuttling of FOXO1 to the nucleus. Furthermore, oxidative stress leads to loss of beta-cell maturity genes MAFA and PDX1, and to a concomitant increase in progenitor marker expression of SOX9 and HES1. Overall, we propose that oxidative stress-induced beta-cell failure may result from partial dedifferentiation. Targeting antioxidant mechanisms may preserve functional beta-cell mass in early stages of development of T1D.Nephrolog
Successful new product development by optimizing development process effectiveness in highly regulated sectors: the case of the Spanish medical devices sector
Rapid development and commercialization of new products is of vital importance for small and medium sized enterprises (SME) in regulated sectors. Due to strict regulations, competitive advantage can hardly be achieved through the effectiveness of product concepts only. If an SME in a highly regulated sector wants to excell in new product development (NPD) performance, the company should focus on the flexibility, speed, and productivity of its NPD function: i.e. the development process effectiveness. Our main research goals are first to explore if SMEs should focus on their their development process effectiveness rather than on their product concept effectiveness to achieve high NPD performance; and second, to explore whether a shared pattern in the organization of the NPD function can be recognized to affect NPD performance positively. The medical devices sector in Spain is used as an example of a\ud
highly regulated sector. A structured survey among 11 SMEs, of which 2 were studied also as in in-depth case studies, led to the following results. First of all, indeed the companies in the dataset which focused on the effectiveness of their development process, stood out in NPD performance. Further, the higher performing companies did have a number of commonalities in the organisation of their NPD function: 1) The majority of the higher performing firms had an NPD strategy characterized by a predominantly incremental project portfolio.\ud
2) a) Successful firms with an incremental project portfolio combined this with a functional team structure b) Successful firms with a radical project portfolio combined this with a heavyweight or autonomous team structure.\ud
3) A negative reciprocal relationship exists between formalization of the NPD processes and the climate of the NPD function, in that a formalized NPD process and an innovative climate do not seem to reinforce each other. Innovative climate combined with an informal NPD process does however contribute positively to NPD performance. This effect was stronger in combination with a radical project portfolio. The highest NPD performance was measured for companies focusing mainly on incremental innovation. It is argued that in highly regulated sectors, companies with an incremental product portfolio would benefit from employing a functional structure. Those companies who choose for a more radical project portfolio in highly regulated sectors should be aware\ud
that they are likely to excell only in the longer term by focusing on strategic flexibility. In their NPD organization, they might be well advised to combine informal innovation processes with an innovative climate
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