Relating size and functionality in human social networks through complexity.

Extensive empirical evidence suggests that there is a maximal number of people with whom an individual can maintain stable social relationships (the Dunbar number). We argue that this arises as a consequence of a natural phase transition in the dynamic self-organization among N individuals within a social system. We present the calculated size dependence of the scaling properties of complex social network models to argue that this collective behavior is an enhanced form of collective intelligence. Direct calculation establishes that the complexity of social networks as measured by their scaling behavior is nonmonotonic, peaking around 150, thereby providing a theoretical basis for the value of the Dunbar number. Thus, we establish a theory-based bridge spanning the gap between sociology and psychology.

Sentinel lymph node biopsy in microinvasive ductal carcinoma in situ.

BACKGROUND: Microinvasive breast cancer is an uncommon pathological entity. Owing to the rarity of this condition, its surgical axillary management and overall prognosis remain controversial. METHODS: A database was analysed to identify patients with microinvasive ductal carcinoma in situ (DCIS) who had surgery for invasive breast cancer at the European Institute of Oncology, Milan, between 1998 and 2010. Women who had undergone axillary staging by sentinel lymph node biopsy were included in the study. RESULTS: Of 257 women with microinvasive breast cancer who underwent sentinel lymph node biopsy (SLNB), 226 (87·9 per cent) had negative sentinel lymph nodes (SLNs) and 31 had metastatic SLNs. Twelve patients had isolated tumour cells (ITCs), 14 had micrometastases and five had macrometastases in sentinel nodes. Axillary lymph node dissection was performed in 16 of the 31 patients with positive SLNs. After a median follow-up of 11 years, only one regional first event was observed in the 15 patients with positive SLNs who did not undergo axillary lymph node dissection. There were no regional first events in the 16 patients with positive SLNs who had axillary dissection. CONCLUSION: Good disease-free and overall survival were found in women with positive SLNs and microinvasive DCIS. This study is in line with studies showing that SLNB in microinvasive DCIS may not be useful, and supports the evidence that less surgery can provide the same level of overall survival with better quality of life.

[Quality of life and psychologic features of subjects with chronic respiratory diseases]. / Qualità della vita ed aspetti psicologici nei soggetti affetti da malattie respiratorie croniche.

The aim of this study is to verify the psychological attitude and the quality of life in patients suffering from chronic respiratory insufficiency. Taking for granted that a bad quality of life is connected with the symptom of a depressed state (loss of appetite, quality of sleep, sexuality, psychomotor slowing down, loss of energy, weariness, reduced interest for the external world, feelings of self-devaluation, reduced working and concentration capacity, complainings of turning over type) we have taken as index of "normal quality of life" the lack of these attitudes correlating them to the clinical symptoms and/or the patient's functional troubles and verifying how much they can affect the psychological features and how much the deterioration of the quality of life. For this reason a questionnaire, taken from the MMPI test (Minnesota Multiphasic Personality Inventory), restricted to the items related to the D scale (depression scale), has been given to one hundred COPD patients who had been examined previously from a clinical functional point of view. In the end, we have drawn our results both on the ground of the answers given by the patients to the single questions and on the grounds of the total score D (= depression index) and relating the previous data with the clinical-functional ones. Finally we have compareted these data with those ones connected with non selected population. So we have succeeded in outlining a psychophysical profile of the patient suffering from chronic respiratory diseases. Such a profile is marked by an objective element, that is pathology, and by a psychological element inserted into the organic one as there is an inter-dependence between pathology and psychological features. From the collected data, we have noted the behavioural spheres which are more upset are working capacities, sleep and mood and these features are directly proportional to the seriousness of the pathology. From a practical and therapeutic point of view, all this can be of great importance.

[The families of diabetic children: a 2-year follow-up]. / Studio su famiglie di bambini diabetici: follow-up di 2 anni.

A great amount of clinical and experimental evidence has been accumulated on the role of immunological early events in the development of type 1 diabetes mellitus. In order to try to make a precocious diagnosis of type 1 diabetes mellitus, the Authors have studied all the components of the family in a group of diabetic children. This study is a part of a collaborative International Study called IFS (International Family Study). The Authors describe the scheme of this project in detail. During this study the Authors made a very early diagnosis of diabetes in a child, brother of another diabetic boy. The importance of this approach to the diabetic disease is discussed.