Potential for the dynamics of pedestrians in a socially interacting group

We introduce a simple potential to describe the dynamics of the relative motion of two pedestrians socially interacting in a walking group. We show that the proposed potential, based on basic empirical observations and theoretical considerations, can qualitatively describe the statistical properties of pedestrian behavior. In detail, we show that the two-dimensional probability distribution of the relative distance is determined by the proposed potential through a Boltzmann distribution. After calibrating the parameters of the model on the two-pedestrian group data, we apply the model to three-pedestrian groups, showing that it describes qualitatively and quantitatively well their behavior. In particular, the model predicts that three-pedestrian groups walk in a V-shaped formation and provides accurate values for the position of the three pedestrians. Furthermore, the model correctly predicts the average walking velocity of three-person groups based on the velocity of two-person ones. Possible extensions to larger groups, along with alternative explanations of the social dynamics that may be implied by our model, are discussed at the end of the paper.

Endocardial Invasion of Lung Cancer Undiagnosable before Autopsy

A 59-year-old male patient presented with left chest discomfort on admission. His medical history included encephalitis in childhood and his smoking history was 20 cigarettes per day for 40 years. A physical examination showed an anemic and edematous face with weak respiratory sounds in the left lung. The patient had elevated calcium levels and decreased hemoglobin and potassium. His parathyroid hormone-related protein level was elevated. Thoracic radiography showed cardiomegaly and computed tomography revealed a left lung mass with invasion of the heart and pleural effusion. Magnetic resonance imaging showed endocardial invasion of the tumor mass. Gallium-68 imaging revealed positive accumulation in the region surrounding the heart. No diagnoses were possible upon frequent cytology of his sputum and pleural effusion. The patient died from congestive heart failure with anoxia 38 days after admission. An autopsy revealed tumoral mass occlusion in the left main bronchus and tumoral invasion of the left atrium, left ventricle, and aorta.

The power of human gaze on infant learning

Social learning enables infants to acquire information, especially through communication. However, it is unknown whether humans are the prime source of information for infant learning. Here we report that humans have a powerful influence on infants' object learning compared with nonhuman agents (robots). Twelve-month-old infants were shown videos in which a human or a robot gazed at an object. The results demonstrated that the infants followed the gaze direction of both agents, but only human gaze facilitated their object learning: Infants showed enhanced processing of, and preferences for, the target object gazed at by the human but not by the robot. Importantly, an extended fixation on a target object without the orientation of human gaze did not produce these effects. Together, these findings show the importance of humanness in the gazer, suggesting that infants may be predisposed to treat humans as privileged sources of information for learning.

Infants understand the referential nature of human gaze but not robot gaze

Infants can acquire much information by following the gaze direction of others. This type of social learning is underpinned by the ability to understand the relationship between gaze direction and a referent object (i.e., the referential nature of gaze). However, it is unknown whether human gaze is a privileged cue for information that infants use. Comparing human gaze with nonhuman (robot) gaze, we investigated whether infants' understanding of the referential nature of looking is restricted to human gaze. In the current study, we developed a novel task that measured by eye-tracking infants' anticipation of an object from observing an agent's gaze shift. Results revealed that although 10- and 12-month-olds followed the gaze direction of both a human and a robot, only 12-month-olds predicted the appearance of objects from referential gaze information when the agent was the human. Such a prediction for objects reflects an understanding of referential gaze. Our study demonstrates that by 12 months of age, infants hold referential expectations specifically from the gaze shift of humans. These specific expectations from human gaze may enable infants to acquire various information that others convey in social learning and social interaction.

Spontaneous remission of epstein-barr virus-positive diffuse large B-cell lymphoma of the elderly

A 94-year-old female patient presented with anorexia and left axillar lymphadenopathy on admission. Her past history was angina pectoris at 83 years of age and total gastrectomy due to gastric cancer at 87 years. The family history revealed that her son had had a malignant lymphoma, the histopathological diagnosis of which was diffuse large B-cell lymphoma. A physical examination showed both cervical, axillar, and inguinal lymphadenopathy without tenderness. She had elevated lactate dehydrogenase, ferritin, and soluble interleukin-2 receptor (sIL-2R). Whole-body computed tomography confirmed the cervical, axillary, and inguinal lymphadenopathy. Gallium-68 imaging revealed positive accumulation in these superficial lymph nodes. A right inguinal lymph node biopsy showed features of Epstein-Barr virus-associated lymphoproliferative disorder. Immunohistological studies on this lymph node biopsy showed CD20-positive large cells, CD3-positive small cells, and CD30-partly-positive large cells. In situ hybridization showed Epstein-Barr virus-positive, LMP-partly-positive, and EBNA2-negative cells. She refused chemotherapy as her son had died from hematemesis during chemotherapy. She received intravenous hyperalimentation for 1 month after admission. No palpable lymph nodes were identified by physical examination or computed tomography 3 months after admission, and regression of lactate dehydrogenase, ferritin, and sIL-2R was observed. She recovered from anorexia and was discharged. She died from pneumonia 10 months later after initial symptoms of anorexia. The autopsy showed no superficial lymphadenopathy.

A microscopic "social norm" model to obtain realistic macroscopic velocity and density pedestrian distributions

We propose a way to introduce in microscopic pedestrian models a “social norm” in collision avoiding and overtaking, i.e. the tendency, shared by pedestrians belonging to the same culture, to avoid collisions and perform overtaking in a preferred direction. The “social norm” is implemented, regardless of the specific collision avoiding model, as a rotation in the perceived velocity vector of the opponent at the moment of computation of the collision avoiding strategy, and justified as an expectation that the opponent will follow the same “social norm” (for example a tendency to avoid on the left and overtake on the right, as proposed in this work for Japanese pedestrians). By comparing with real world data, we show that the introduction of this norm allows for a better reproduction of macroscopic pedestrian density and velocity patterns.

Sleep apnoea syndrome as a risk for mortality in elderly inpatients

OBJECTIVE

The characteristics of sleep apnoea syndrome (SAS) in the elderly, including subtype classification and association with mortality, have not been fully elucidated. This study examined these factors in an elderly Japanese inpatient population.

METHODS

Overnight polysomnography was used to diagnose and classify SAS in 145 elderly inpatients (mean ± age 81 ± 8 years). Clinical data, including brain computerized tomography findings, were recorded. The study population included nine inpatients with obstructive SAS, 12 with central SAS, 25 with mixed SAS and 99 controls (no SAS).

RESULTS

Increased body mass index and grade of aortic arch calcification independently contributed to risk of all subtypes of SAS combined. There was an independent association between SAS and increased risk of mortality from all causes as well as from pneumonia and from cardiovascular disease. Only mixed SAS was independently and positively associated with increased risk of death from pneumonia.

CONCLUSIONS

Obstructive, central and mixed SAS were associated with increased risk of cardiovascular related and all-cause mortality. Mixed SAS was associated with an increase in mortality from pneumonia. There was no relationship between mortality and severity of SAS.

[A case of neuromyelitis optica presenting ileus as a neurologic finding]

PURPOSE

To report an atypical case of neuromyelitis optica (NMO) with Sjögren syndrome that presented only ileus as a neurologic finding.

CASE

A thirty two-year-old woman was hospitalized for abnormal abdominal symptoms, and was diagnosed as having paralytic ileus. Dry eye symptoms due to Sjogren syndrome were also observed, and visual acuity OU decreased suddenly 10 days after hospitalization. The best corrected visual acuity was 0.04 OD and 0.6 OS, and the optic discs OU were swollen and red. Although no neurologic signs were found, pleocytosis and abnormal MRI findings suggested NMO. Steroid pulse therapy was performed, and after three cycles, the ileus symptoms disappeared, and the disturbed visual acuity OU returned to normal. Because the anti-aquaporin 4 antibody was positive and no abnormal abdominal findings that might have caused ileus were found, we diagnosed NMO presenting only paralytic ileus as a neurologic finding.

CONCLUSIONS

Differential diagnosis is important for NMO initiated by ileus as the only neurologic sign.

"Robovie, you'll have to go into the closet now": children's social and moral relationships with a humanoid robot

Children will increasingly come of age with personified robots and potentially form social and even moral relationships with them. What will such relationships look like? To address this question, 90 children (9-, 12-, and 15-year-olds) initially interacted with a humanoid robot, Robovie, in 15-min sessions. Each session ended when an experimenter interrupted Robovie's turn at a game and, against Robovie's stated objections, put Robovie into a closet. Each child was then engaged in a 50-min structural-developmental interview. Results showed that during the interaction sessions, all of the children engaged in physical and verbal social behaviors with Robovie. The interview data showed that the majority of children believed that Robovie had mental states (e.g., was intelligent and had feelings) and was a social being (e.g., could be a friend, offer comfort, and be trusted with secrets). In terms of Robovie's moral standing, children believed that Robovie deserved fair treatment and should not be harmed psychologically but did not believe that Robovie was entitled to its own liberty (Robovie could be bought and sold) or civil rights (in terms of voting rights and deserving compensation for work performed). Developmentally, while more than half the 15-year-olds conceptualized Robovie as a mental, social, and partly moral other, they did so to a lesser degree than the 9- and 12-year-olds. Discussion focuses on how (a) children's social and moral relationships with future personified robots may well be substantial and meaningful and (b) personified robots of the future may emerge as a unique ontological category.

Longitudinal changes of the laboratory data of chronic hepatitis C patients with sustained virological response on long-term follow-up

There is no study that follows up longitudinal changes in laboratory data of patients with C-viral chronic liver disease (C-CLD) who achieved sustained virological esponse (SVR) with interferon treatment in a long-term study. We investigated the laboratory data in a long-term retrospective cohort study of 581 patients with C-CLD who underwent liver biopsy between January 1986 and December 2005. 467 were treated with interferon and 207 of these patients achieved SVR with follow-up periods of 8.36 ± 5.13 years. Alanine aminotransferase (ALT) levels, albumin levels, platelet counts, and the aspartate aminotransferase (AST)-to-platelet ratio index (APRI) values were serially examined during the follow-up period. None of the 207 patients with SVR exhibited hepatitis C virus (HCV) RNA positivity more than 6 months after the end of IFN treatment. Platelet counts and albumin levels increased only in those with eradication of HCV. APRI values decreased more in patients with SVR than in those with nonsustained virological responses (non-SVR). Patients who achieved SVR and had fibrosis stage 0-1 and 2-4 at enrolment had platelet counts that longitudinally increased by 2.81 ± 3.95 and 5.49 ± 4.53 × 10(3) /μL during the 10-year follow-up period, respectively. Albumin levels continuously increased during the first 2 years by 0.15 ± 0.31 and 0.33 ± 0.37 in fibrosis stage 0-1 and 2-4, respectively and then plateaued. ALT levels decreased rapidly one year after the start of treatment by 110.3 ± 140.0 and 100.5 ± 123.4 in fibrosis 0-1 and 2-4, respectively. HCV RNA negativity persisted in all patients with SVR, and laboratory data including APRI longitudinally improved during the long-term follow-up period.

Conversational gaze mechanisms for humanlike robots

During conversations, speakers employ a number of verbal and nonverbal mechanisms to establish who participates in the conversation, when, and in what capacity. Gaze cues and mechanisms are particularly instrumental in establishing the participant roles of interlocutors, managing speaker turns, and signaling discourse structure. If humanlike robots are to have fluent conversations with people, they will need to use these gaze mechanisms effectively. The current work investigates people's use of key conversational gaze mechanisms, how they might be designed for and implemented in humanlike robots, and whether these signals effectively shape human-robot conversations. We focus particularly on whether humanlike gaze mechanisms might help robots signal different participant roles, manage turn-exchanges, and shape how interlocutors perceive the robot and the conversation. The evaluation of these mechanisms involved 36 trials of three-party human-robot conversations. In these trials, the robot used gaze mechanisms to signal to its conversational partners their roles either of two addressees, an addressee and a bystander, or an addressee and a nonparticipant. Results showed that participants conformed to these intended roles 97% of the time. Their conversational roles affected their rapport with the robot, feelings of groupness with their conversational partners, and attention to the task.