105 research outputs found
On the definition of entanglement entropy in lattice gauge theories
We focus on the issue of proper definition of entanglement entropy in lattice
gauge theories, and examine a naive definition where gauge invariant states are
viewed as elements of an extended Hilbert space which contains gauge
non-invariant states as well. Working in the extended Hilbert space, we can
define entanglement entropy associated with an arbitrary subset of links, not
only for abelian but also for non-abelian theories. We then derive the
associated replica formula. We also discuss the issue of gauge invariance of
the entanglement entropy. In the gauge theories in arbitrary space
dimensions, we show that all the standard properties of the entanglement
entropy, e.g. the strong subadditivity, hold in our definition. We study the
entanglement entropy for special states, including the topological states for
the gauge theories in arbitrary dimensions. We discuss relations of our
definition to other proposals.Comment: 29 pages, 1 figure, a comment and more references added, some typos
correcte
Fish assemblages associated with three types of artificial reefs: density of assemblages and possible impacts on adjacent fish abundance
We evaluated the effectiveness of wooden artificial reefs (ARs) as fish habitat. Three types of ARs, made of cedar logs, broadleaf tree logs, and PVC pipes, respectively,
were deployed in triplicate at 8-m depth off Maizuru, Kyoto Prefecture, Sea of Japan, in May 2004. Fish assemblages associated with each of the nine ARs were observed by using
SCUBA twice a month for four years. Fish assemblages in the adjacent habitat were also monitored for two years before and four years after reef deployment. In the surveyed areas
(ca. 10 m2) associated with each of the cedar, broadleaf, and PVC ARs, the average number of fish species was 4.14, 3.49, and 3.00, and the average number of individuals was 40.7, 27.9, and 20.3, respectively. The estimated biomass was also more greater when associated with the cedar ARs than with other ARs. Visual censuses of the habitat adjacent to the ARs revealed that the number of fish species and the density of individuals were not affected by the deployment of the ARs. Our results support the superiority of cedar as an AR material and indicate that deployment of wooden ARs causes no reduction of fish abundance in adjacent natural reefs
Drop Metastasis of Adrenocorticotropic Hormone-Producing Pituitary Carcinoma to the Cauda Equina
The diagnosis of pituitary carcinoma cannot be made easily histologically, and most cases of pituitary carcinoma are diagnosed only after the clinical detection of metastasis. Distant metastasis of pituitary tumor occurs in 0.1% to 0.2% of cases and has been reported in the liver, bone and central nervous system, with only one case of metastasis to the cauda equine reported. This study describes a rare case of the drop metastasis of adrenocorticotropic hormone-producing pituitary adenocarcinoma to the cauda equina, causing cauda equina syndrome
Coupled Heisenberg antiferromagnetic chains in an effective staggered field
We present a systematic study of coupled Heisenberg antiferromagnetic
chains in an effective staggered field. We investigate several effects of the
staggered field in the {\em higher} ({\em two or three}) {\em dimensional} spin
system analytically. In particular, in the case where the staggered field and
the inter-chain interaction compete with each other, we predict, using
mean-field theory, a characteristic phase transition. The spin-wave theory
predicts that the behavior of the gaps induced by the staggered field is
different between the competitive case and the non-competitive case. When the
inter-chain interactions are sufficiently weak, we can improve the mean-field
phase diagram by using chain mean-field theory and the analytical results of
field theories. The ordered phase region predicted by the chain mean-field
theory is substantially smaller than that by the mean-field theory.Comment: 13pages, 12figures, to be published in PR
Development of new experimental platform ‘MARS’—Multiple Artificial-gravity Research System—to elucidate the impacts of micro/partial gravity on mice
This Japan Aerospace Exploration Agency project focused on elucidating the impacts of partial gravity (partial g) and microgravity (μg) on mice using newly developed mouse habitat cage units (HCU) that can be installed in the Centrifuge-equipped Biological Experiment Facility in the International Space Station. In the first mission, 12 C57BL/6 J male mice were housed under μg or artificial earth-gravity (1 g). Mouse activity was monitored daily via downlinked videos; μg mice floated inside the HCU, whereas artificial 1 g mice were on their feet on the floor. After 35 days of habitation, all mice were returned to the Earth and processed. Significant decreases were evident in femur bone density and the soleus/gastrocnemius muscle weights of μg mice, whereas artificial 1 g mice maintained the same bone density and muscle weight as mice in the ground control experiment, in which housing conditions in the flight experiment were replicated. These data indicate that these changes were particularly because of gravity. They also present the first evidence that the addition of gravity can prevent decreases in bone density and muscle mass, and that the new platform ‘MARS’ may provide novel insights on the molecular-mechanisms regulating biological processes controlled by partial g/μg
Development and evaluation of a novel 99mTc-labeled annexin A5 for early detection of response to chemotherapy
金沢大学疾患モデル総合研究センター99mTc-HYNIC-annexin A5 can be considered as a benchmark in the field of apoptosis imaging. However, 99mTc-HYNIC-annexin A5 has characteristics of high uptake and long retention in non-target tissues such as kidney and liver. To minimize this problem, we developed a novel 99mTc-labeled annexin A5 using a bis(hydroxamamide) derivative [C3(BHam)2] as a bifunctional chelating agent, and evaluated its usefulness as an imaging agent for detecting apoptosis. The amino group of C3(BHam)2 was converted to a maleimide group, and was coupled to thiol groups of annexin A5 pretreated with 2-iminothiolane. 99mTc labeling was performed by a ligand exchange reaction with 99mTc-glucoheptonate. Biodistribution experiments for both 99mTc-C3(BHam)2-annexin A5 and 99mTc-HYNIC-annexin A5 were performed in normal mice. In addition, in tumor-bearing mice, the relationship between the therapeutic effects of chemotherapy (5-FU) and the tumor accumulation of 99mTc-C 3(BHam)2-annexin A5 just after the first treatment of 5-FU was evaluated. 99mTc-C3(BHam)2-annexin A5 was prepared with a radiochemical purity of over 95%. In biodistribution experiments, 99mTc-C3(BHam)2-annexin A5 had a much lower kidney accumulation of radioactivity than 99mTc-HYNIC- annexin A5. In the organs for metabolism, such as liver and kidney, radioactivity after the injection of 99mTc-HYNIC-annexin A5 was residual for a long time. On the other hand, radioactivity after the injection of 99mTc-C3(BHam)2-annexin A5 gradually decreased. In therapeutic experiments, tumor growth in the mice treated with 5-FU was significantly inhibited. Accumulation of 99mTc-C 3(BHam)2-annexin A5 in tumors significantly increased after 5-FU treatment. The accumulation of radioactivity in tumor correlated positively with the counts of TUNEL-positive cells. These findings suggest that 99mTc-C3(BHam)2-annexin A5 may contribute to the efficient detection of apoptotic tumor response after chemotherapy. © 2013 Ogawa et al.CC-BY 4.
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