Ground State and Elementary Excitations of the S=1 Kagome Heisenberg Antiferromagnet

Low energy spectrum of the S=1 kagom\'e Heisenberg antiferromagnet (KHAF) is studied by means of exact diagonalization and the cluster expansion. The magnitude of the energy gap of the magnetic excitation is consistent with the recent experimental observation for \mpynn. In contrast to the $S=1/2$ KHAF, the non-magnetic excitations have finite energy gap comparable to the magnetic excitation. As a physical picture of the ground state, the hexagon singlet solid state is proposed and verified by variational analysis.Comment: 5 pages, 7 eps figures, 2 tables, Fig. 4 correcte

Performance, feed utilization, and hepatic metabolic response of weaned juvenile Atlantic bluefin tuna (Thunnus thynnus L.): effects of dietary lipid level and source

The development of formulated diets and feeds is essential to increase production of farmed tuna species. There is limited knowledge of this topic, mainly on Pacific Bluefin tuna (Thunnus orientalis) in Japan, whereas no major attempts have been made with Atlantic Bluefin tuna (Thunnus thynnus; ABT). In the present study, two trials were performed using inert formulated diets as on-growing feeds for weaned ABT juvenile in order to establish adequate dietary levels of both lipid and omega-3 long-chain polyunsaturated fatty acids (LC-PUFA). In a first trial, ABT (initial weight = 2.9±0.9g) were fed for 10 days with either a commercial (Magokoro®, MGK) or two experimental feeds with two different lipid levels (15 or 20%) using krill oil (KO) as the single lipid source in order to estimate the suitable lipid content. Fish fed MGK displayed the highest growth, followed by 15KO, with no differences in fish survival. Thus, a lipid content of 15% was considered better than 20% for ABT juveniles. In the second trial, fish (initial weight = 3.3 ± 0.6g) were fed either MGK, 15KO or a feed containing 15% lipid with a combination (1:1, v/v) KO and rapeseed oil (RO) (15KORO). Fish fed 15KO and 15KORO showed the highest growth in terms of weight and fork length (including weight gain and SGR). Increasing dietary lipid level or adding RO to the feeds did not increase liver lipid content. The liver fatty acid profile largely reflected dietary intake confirming very limited LC-PUFA biosynthetic activity for this teleost species. In this respect, liver of fish fed 15KO and 20KO displayed the highest contents of docosahexaenoic acid (DHA). The hepatic expression of genes of lipid and fatty acid metabolism, transcription factors, and antioxidant enzymes was investigated with many of the genes showing regulation by both dietary lipid and LC-PUFA contents. The present study showed promising results that suggested ABT juveniles can be on grown on inert dry feeds that supported good fish growth and the accumulation of the health-promoting fatty acid DHA. Further studies are required in order to fully elucidate lipid and fatty acid requirements of this iconic species regarding dietary sources and production costs.En prensa1,52

Nerve fibres containing neuropeptide Y in the atrioventricular valves of Japanese monkey and rat; a light and electron microscopic study

Dense distribution of varicose fibres containing neuropeptide Y-like immunoreactivity (NPYLI) was found in the atrioventricular valves of the Japanese monkey, and moderately in the rat. The immunoelectron microscopy using immunogolds resulted in the localization of NPY-LI within the densecored vesicles which existed with the small clear vesicles in the unmyelinated axons near the endocardium. These NPY-LI-containing fibres may participate in regulation of vasomotor role or other functions of the atrioventricular valves

Successful closure of large blunt macular chorioretinal rupture: a case report

Daisuke Muramatsu1, Takuya Iwasaki2, Tsuyoshi Agawa1, Masahiko Usui1, Hiroshi Goto11Department of Ophthalmology, Tokyo Medical University, 2Department of Ophthalmology, Tokyo Medical University Ibaraki Medical Center, Tokyo, JapanAbstract: The authors present a rare case of large chorioretinal rupture caused by blunt traumatic injury of the globe. A 22-year-old woman sustained a blunt injury to her left eye. The best-corrected Snellen visual acuity was 2/20 in her left eye, and hyphema and vitreous hemorrhage were noted. The day after the injury occurred the vitreous hemorrhage had disappeared. Fundus examination revealed a crescent-shaped retinal rupture three disc diameters in size near the macula, and a choroidal rupture six disc diameters in size that was over the vascular arcade. Three days after the injury, vitrectomy with internal limiting membrane peeling was performed. Postoperative prone positioning was maintained for 4 days. Five days postoperatively, closure of the ruptured retina was confirmed. The visual acuity improved to 16/20 4 months after surgery and this was maintained over a 48-month period. In conclusion, early vitrectomy with internal limiting membrane peeling after injury was effective for a case involving severe blunt chorioretinal rupture with closed globe injury.Keywords: choroidal rupture, retinal rupture, traumatic macular hole, closed globe injury, internal limiting membran

Biological activity is the likely origin of the intersection between the photoreceptor inner and outer segments of the rat retina as determined by optical coherence tomography

Yasuyuki Yamauchi, Hiromichi Yagi, Yoshihiko Usui, Keisuke Kimura, Tsuyoshi Agawa, Rintaro Tsukahara, Naoyuki Yamakawa, Hiroshi GotoDepartment of Ophthalmology, Tokyo Medical University Hospital, Tokyo, JapanBackground: Recent research on macular diseases has prompted investigations into the condition of the intersection between the photoreceptor inner and outer segments (IS/OS) and the relationship with retinal photoreceptor abnormalities. Although the origin of the IS/OS in optical coherence tomography (OCT) images is unclear, it may be related to either the cellular activity of the photoreceptors or the structure of the OS disks. To address this question, we compared the IS/OS status in OCT images of rat retinas before and after euthanasia.Methods: OCT images were taken before and after euthanasia in four eyes of two Brown Norway rats. After the OCT images were taken, the rats were used for histopathological studies to confirm that retinal structures were intact.Results: Before euthanasia, the IS/OS and external limiting membrane (ELM) line were clearly identifiable on the OCT images. However, after euthanasia, neither the IS/OS nor the ELM line was evident in three out of four eyes, and a faint IS/OS and an ELM line were identified in one eye. Histopathological analysis did not show any abnormalities in the retina in any of the four eyes.Conclusion: The origin of the IS/OS identified in OCT images is likely related to the biological activities of the photoreceptor cells.Keywords: IS/OS, OCT, histopathology, biological activit