Dynamics of Opinion Forming in Structurally Balanced Social Networks

A structurally balanced social network is a social community that splits into two antagonistic factions (typical example being a two-party political system). The process of opinion forming on such a community is most often highly predictable, with polarized opinions reflecting the bipartition of the network. The aim of this paper is to suggest a class of dynamical systems, called monotone systems, as natural models for the dynamics of opinion forming on structurally balanced social networks. The high predictability of the outcome of a decision process is explained in terms of the order-preserving character of the solutions of this class of dynamical systems. If we represent a social network as a signed graph in which individuals are the nodes and the signs of the edges represent friendly or hostile relationships, then the property of structural balance corresponds to the social community being splittable into two antagonistic factions, each containing only friends

p27 Deficiency Cooperates with Bcl-2 but Not Bax to Promote T-Cell Lymphoma

The effect of Bcl-2 on oncogenesis is complex and expression may either delay or accelerate oncogenesis. The pro-oncogenic activity is attributed to its well characterized anti-apoptotic function while the anti-oncogenic function has been attributed to its inhibition of cellular proliferation. Recent studies demonstrate that p27 may mediate the effects of Bcl-2 on cellular proliferation. We hypothesized that p27 may suppress tumor formation by Bcl-2 family members. To test this hypothesis, cell cycle inhibition and lymphoma development were examined in Lck-Bcl-2 and Lck-Bax38/1 transgenic mice deficient in p27. Strikingly, p27 deficiency synergistically cooperates with Bcl-2 to increase T cell hyperplasia and development of spontaneous T cell lymphomas. Within 1 year, >90% of these mice had developed thymic T cell lymphomas. This high penetrance contrasts with a one year incidence of <5% of thymic lymphoma in Lck-Bcl-2 or p27 −/− mice alone. In contrast, p27 deficiency had no effect on tumor formation in Lck-Bax38/1 transgenic mice, another model of T cell lymphoma. Histologically the lymphomas in p27 −/− Lck-Bcl-2 mice are lymphoblastic and frequently involve multiple organs suggesting an aggressive phenotype. Interestingly, in mature splenic T cells, Bcl-2 largely retains its anti-proliferative function even in the absence of p27. T cells from p27 −/− Lck-Bcl-2 mice show delayed kinetics of CDK2 Thr-160 phosphorylation. This delay is associated with a delay in the up regulation of both Cyclin D2 and D3. These data demonstrate a complex relationship between the Bcl-2 family, cellular proliferation, and oncogenesis and demonstrate that p27 up-regulation is not singularly important in the proliferative delay observed in T cells expressing Bcl-2 family members. Nonetheless, the results indicate that p27 is a critical tumor suppressor in the context of Bcl-2 expression

Consensus Paper: Cerebellum and Social Cognition.

The traditional view on the cerebellum is that it controls motor behavior. Although recent work has revealed that the cerebellum supports also nonmotor functions such as cognition and affect, only during the last 5 years it has become evident that the cerebellum also plays an important social role. This role is evident in social cognition based on interpreting goal-directed actions through the movements of individuals (social "mirroring") which is very close to its original role in motor learning, as well as in social understanding of other individuals' mental state, such as their intentions, beliefs, past behaviors, future aspirations, and personality traits (social "mentalizing"). Most of this mentalizing role is supported by the posterior cerebellum (e.g., Crus I and II). The most dominant hypothesis is that the cerebellum assists in learning and understanding social action sequences, and so facilitates social cognition by supporting optimal predictions about imminent or future social interaction and cooperation. This consensus paper brings together experts from different fields to discuss recent efforts in understanding the role of the cerebellum in social cognition, and the understanding of social behaviors and mental states by others, its effect on clinical impairments such as cerebellar ataxia and autism spectrum disorder, and how the cerebellum can become a potential target for noninvasive brain stimulation as a therapeutic intervention. We report on the most recent empirical findings and techniques for understanding and manipulating cerebellar circuits in humans. Cerebellar circuitry appears now as a key structure to elucidate social interactions

Grey Matter Volume in the Cerebellum is Related to the Processing of Grammatical Rules in a Second Language: A Structural Voxel-based Morphometry Study

The experience of learning and using a second language (L2) has been shown to affect the grey matter (GM) structure of the brain. Importantly, GM density in several cortical and subcortical areas has been shown to be related to performance in L2 tasks. Here, we show that bilingualism can lead to increasedGMvolume in the cerebellum, a structure that has been related to the processing of grammatical rules. Additionally, the cerebellar GM volume of highly proficient L2 speakers is correlated to their performance in a task tapping on grammatical processing in an L2, demonstrating the importance of the cerebellum for the establishment and use of grammatical rules in an L2

The important role of primary care providers in the detection of alpha-1 antitrypsin deficiency

Objective: Alpha-1 antitrypsin deficiency (AATD) is an underrecognized genetic disorder that can cause chronic obstructive pulmonary disease (COPD) and liver cirrhosis, two clinical conditions commonly seen by primary care physicians. AATD is estimated to affect 1/4000-1/5000 people in the United States and 1-2% of all COPD cases. Methods: PubMed was searched for relevant articles using AAT/AATD-related terms. Results: Unfortunately, <10% of symptomatic individuals have been properly diagnosed primarily due to the underdiagnosis of COPD and the lack of awareness of AATD as a possible underlying cause. Because primary care providers are most likely to be the first to encounter symptomatic individuals, their role in the identification and early diagnosis of AATD patients is instrumental, particularly since therapy to slow lung disease progression is available. The diagnosis of AATD is laboratory-based rather than clinical. Testing for AATD should be part of the reflex testing that follows any COPD diagnosis or unexplained liver disease and can be performed by determining the AAT phenotype or genotype along with serum AAT levels. Both nonpharmacological and pharmacological approaches are recommended for treatment of lung disease, including smoking cessation, bronchodilators or supplemental oxygen as needed. Specific augmentation of AAT levels with regular purified AAT infusions has been found to slow lung function decline and emphysema progression in patients with moderate airflow obstruction and severely low serum AAT levels. Conclusions: Improving primary care provider awareness and promoting regular reflex testing all COPD patients for AATD may significantly improve the care of COPD patients

Interactive Faculty Development Seminars Improve the Quality of Written Feedback in Ambulatory Teaching

We performed a pre–post study of the impact of three 90-minute faculty development workshops on written feedback from encounters during an ambulatory internal medicine clerkship. We coded 47 encounters before and 43 after the workshops, involving 9 preceptors and 44 third-year students, using qualitative and semiquantitative methods. Postworkshop, the mean number of feedback statements increased from 2.8 to 3.6 statements (P = .06); specific (P = .04), formative (P = .03), and student skills feedback (P = .01) increased, but attitudinal (P = .13) and corrective feedback did not (P = .41). Brief, interactive, faculty development workshops may refine written feedback, resulting in more formative specific written feedback comments

Unmet Expectations for Care and the Patient-physician Relationship

OBJECTIVE: To profile patients likely to have unmet expectations for care, examine the effects of such expectations, and investigate how physicians' responses to patients' requests affect the development of unfulfilled expectations. DESIGN: Patient and physician questionnaires were administered before and after outpatient visits. A follow-up telephone survey was administered 2 weeks post visit. SETTING: The offices of 45 family practice, internal medicine, and cardiology physicians. PATIENTS: Nine hundred nine adults reporting a health problem or concern. MEASUREMENTS AND MAIN RESULTS: Before their visits, patients rated their general health and trust in the index physician. After the visit, patients reported upon 8 types of unmet expectations and any request they made. Two weeks thereafter, patients rated their visit satisfaction, improvement, and intention to adhere to the physician's advice. They also reported any postvisit health system contacts. Overall, 11.6% of patients reported ≥1 unmet expectation. Visits in which a patient held an unmet expectation were rated by physicians as less satisfying and more effortful. At follow-up, patients who perceived an unmet expectation for care also reported less satisfaction with their visits, less improvement, and weaker intentions to adhere. Patients with an unmet expectation related to clinical resource allocation had more postvisit health system contacts. Unmet expectations were typically reported by a patient whose request for a resource was not fulfilled. CONCLUSIONS: Unmet expectations adversely affect patients and physicians alike. Physicians' nonfulfillment of patients' requests plays a significant role in patients' beliefs that their physicians did not meet their expectations for care