O(NN) Invariance of the Multi-Field Bounce

In his 1977 paper on vacuum decay in field theory: The Fate of the False Vacuum, Coleman considered the problem of a single scalar field and assumed that the minimum action tunnelling field configuration, the bounce, is invariant under O(4) rotations in Euclidean space. A proof of the O(4) invariance of the bounce was provided later by Coleman, Glaser, and Martin (CGM), who extended the proof to $N>2$ Euclidean dimensions but, again, restricted non-trivially to a single scalar field. As far as we know a proof of O($N$) invariance of the bounce for the tunnelling problem with multiple scalar fields has not been reported, even though it was assumed in many works since, being of phenomenological interest. We make progress towards closing this gap. Following CGM we define the reduced problem of finding a field configuration minimizing the kinetic energy at fixed potential energy. Given a solution of the reduced problem, the minimum action bounce can always be obtained from it by means of a scale transformation. We show that if a solution of the reduced problem exists, then it and the minimum action bounce derived from it are indeed O($N$) symmetric.Comment: 10 pages, 1 figure: v3: match journal versio

Predicting the Prognosis of Swallowing Function in Stroke Patients with Dysphagia Using the Videofluoroscopic Dysphagia Scale

The aim of the present study was to evaluate the correlation between parameters of the videofluoroscopic dysphagia scale (VDS) and the outcome of dysphagia to determine the usefulness of the VDS in patients admitted to convalescent rehabilitation wards. Patients (n = 23) with stroke-related dysphagia admitted to our rehabilitation hospital between April 2007 and March 2009. Medical records and videofluoroscopy findings on admission to hospital were reviewed retrospectively and the VDS score was calculated by adding individual VDS parameters. Subjects were divided into two groups: those who were able to ingest orally without tube feeding before discharge (Group 1) and those who still needed tube feeding on discharge (Group 2). The VDS scores were compared between the two groups. There were no significant differences in any individual parameter on the VDS between the two groups. However, the total VDS score was significantly lower in Group 1 patients (p < 0.05), as was the time from stroke onset to admission to our hospital (p < 0.05). There were no significant differences in any other parameters evaluated. The findings of the present study suggest that the total VDS score may be useful in predicting the prognosis of stroke-related dysphagia

カルバモイルメチルラジカルの環化反応と天然物合成への応用

金沢大学大学院自然科学研究科生理活性物質科学金沢大学薬学

Dedifferentiated chondrosarcoma with leukocytosis and elevation of serum G-CSF. A case report

BACKGROUND: G-CSF is known to function as a hematopoietic growth factor and it is known to be responsible for leukocytosis. G-CSF-producing tumors associated with leukocytosis include various types of malignancies. CASE PRESENTATION: We report the case of a 72-year-old man with dedifferentiated chondrosarcoma characterized by dedifferentiated components of malignant fibrous histiocytoma- or osteosarcoma-like features in addition to conventional chondrosarcoma, arising from his pelvic bone. After hemipelvectomy, when local recurrence and metastasis were identified, leukocytosis appeared and an elevated level of serum granulocyte-colony-stimulating factor (G-CSF) was also recognized. The patient died of multiple organ failure 2 months after surgery. Autopsy specimens showed that the histological specimens of the recurrence and metastasis were dedifferentiated components, without any conventional chondrosarcoma components. G-CSF was expressed only in the dedifferentiated components, not in the chondrosarcoma components, immunohistochemically. CONCLUSION: This is the first report of chondrosarcoma, or any other primary bone tumor, with leukocytosis, probably stimulated by tumor-produced G-CSF from the dedifferentiated components