The Thermal Conductivity of the Second Kind Superconductors In-Pb Alloys

The thermal conductivity of three specimens of indium lead alloys, which belong to the second kind superconductors, has been measured as a function of temperature in magnetic fields, in which the specimens go through the mixed state at intermediate temperatures. In the mixed state there appears a minimum value of the thermal conductivity in the temperature variation as well as in the field variation. The measured thermal conductivity is in good agreement with that calculated from the magnetization by using an average energy gap model proposed by Dubeck et al

Thermal Conductivity of Superconducting and Normal Lanthanum

The thermal conductivity of superconducting and normal f.c.c. lanthanum was measured at the temperature range 1.7 to 7.0°K. The thermal conductivity of yttrium was also measured to test the cryostat. The ratio of the energy gap of lanthanum at absolute zero to the transition temperature, 2Δ(0)/kT_c is 2.9 to 3.0, where T_c=6.04°K. The ratio obtained from the temperature dependence of the thermal conductivity in the superconducting state is in agreement with the value deduced from the ratio of the thermal conductivities of the superconducting to the normal state. Although the specimen employed in this experiment has the resistivity ratio of 44, the magnetization measurements indicate that the specimen is a second kind superconductor due to a trace of impurity contained. High critical fields and the wide range of the field transition can be interpreted in terms of a second kind superconductor

Ubiquitin-Specific Peptidase 46 (Usp46) Regulates Mouse Immobile Behavior in the Tail Suspension Test through the GABAergic System

The tail suspension test (TST) is widely recognized as a useful experimental paradigm for assessing antidepressant activity and depression-like behavior. We have previously identified ubiquitin-specific peptidase 46 (Usp46) as a quantitative trait gene responsible for decreasing immobility time in the TST in mice. This Usp46 mutation has a 3-bp deletion coding for lysine in the open reading frame, and we indicated that Usp46 is implicated in the regulation of the GABAergic system. However, it is not known precisely how the immobile behavior is regulated by the GABAergic system. Therefore, in the present study, we examined whether the immobility time is influenced by drugs affecting the action mediated by GABAA receptor using both 3-bp deleted (the Usp46 mutant) and null Usp46 (Usp46 KO) mice. Nitrazepam, an agonist at the benzodiazepine-binding site of the GABAA receptor, which potentiates the action of GABA, produced a dose-dependent increase in TST immobility time in the Usp46 mutant mice without affecting general behaviors. The Usp46 KO mice exhibited short immobility times comparable to the Usp46 mutant mice, which was also increased by nitrazepam administration. The effects of nitrazepam in the Usp46 mutant and KO mice were antagonized by flumazenil. These results indicate that the 3-bp deleted Usp46 mutation causes a loss-of-function phenotype, and that the GABAA receptor might participate in the regulation of TST immobility time

Post-Training Dephosphorylation of eEF-2 Promotes Protein Synthesis for Memory Consolidation

Memory consolidation, which converts acquired information into long-term storage, is new protein synthesis-dependent. As protein synthesis is a dynamic process that is under the control of multiple translational mechanisms, however, it is still elusive how these mechanisms are recruited in response to learning for memory consolidation. Here we found that eukaryotic elongation factor-2 (eEF-2) was dramatically dephosphorylated within 0.5–2 hr in the hippocampus and amygdala of mice following training in a fear-conditioning test, whereas genome-wide microarrays did not reveal any significant change in the expression level of the mRNAs for translational machineries or their related molecules. Moreover, blockade of NMDA receptors with MK-801 immediately following the training significantly impeded both the post-training eEF-2 dephosphorylation and memory retention. Notably, with an elegant sophisticated transgenic strategy, we demonstrated that hippocampus-specific overexpression of eEF-2 kinase, a kinase that specifically phosphorylates and hence inactivates eEF-2, significantly inhibited protein synthesis in the hippocampus, and this effects was more robust during an “ongoing” protein synthesis process. As a result, late phase long-term potentiation (L-LTP) in the hippocampus and long-term hippocampus-dependent memory in the mice were significantly impaired, whereas short-term memory and long-term hippocampus-independent memory remained intact. These results reveal a novel translational underpinning for protein synthesis pertinent to memory consolidation in the mammalian brain.</p

Post-Training Dephosphorylation of eEF-2 Promotes Protein Synthesis for Memory Consolidation

Memory consolidation, which converts acquired information into long-term storage, is new protein synthesis-dependent. As protein synthesis is a dynamic process that is under the control of multiple translational mechanisms, however, it is still elusive how these mechanisms are recruited in response to learning for memory consolidation. Here we found that eukaryotic elongation factor-2 (eEF-2) was dramatically dephosphorylated within 0.5–2 hr in the hippocampus and amygdala of mice following training in a fear-conditioning test, whereas genome-wide microarrays did not reveal any significant change in the expression level of the mRNAs for translational machineries or their related molecules. Moreover, blockade of NMDA receptors with MK-801 immediately following the training significantly impeded both the post-training eEF-2 dephosphorylation and memory retention. Notably, with an elegant sophisticated transgenic strategy, we demonstrated that hippocampus-specific overexpression of eEF-2 kinase, a kinase that specifically phosphorylates and hence inactivates eEF-2, significantly inhibited protein synthesis in the hippocampus, and this effects was more robust during an “ongoing” protein synthesis process. As a result, late phase long-term potentiation (L-LTP) in the hippocampus and long-term hippocampus-dependent memory in the mice were significantly impaired, whereas short-term memory and long-term hippocampus-independent memory remained intact. These results reveal a novel translational underpinning for protein synthesis pertinent to memory consolidation in the mammalian brain

Bi-Directional Effect of Cholecystokinin Receptor-2 Overexpression on Stress-Triggered Fear Memory and Anxiety in the Mouse

Fear, an emotional response of animals to environmental stress/threats, plays an important role in initiating and driving adaptive response, by which the homeostasis in the body is maintained. Overwhelming/uncontrollable fear, however, represents a core symptom of anxiety disorders, and may disturb the homeostasis. Because to recall or imagine certain cue(s) of stress/threats is a compulsory inducer for the expression of anxiety, it is generally believed that the pathogenesis of anxiety is associated with higher attention (acquisition) selectively to stress or mal-enhanced fear memory, despite that the actual relationship between fear memory and anxiety is not yet really established. In this study, inducible forebrain-specific cholecystokinin receptor-2 transgenic (IF-CCKR-2 tg) mice, different stress paradigms, batteries of behavioral tests, and biochemical assays were used to evaluate how different CCKergic activities drive fear behavior and hormonal reaction in response to stresses with different intensities. We found that in IF-CCKR-2 tg mice, contextual fear was impaired following 1 trial of footshock, while overall fear behavior was enhanced following 36 trials of footshock, compared to their littermate controls. In contrast to a standard Yerkes-Dodson (inverted-U shaped) stress-fear relationship in control mice, a linearized stress-fear curve was observed in CCKR-2 tg mice following gradient stresses. Moreover, compared to 1 trial, 36 trials of footshock in these transgenic mice enhanced anxiety-like behavior in other behavioral tests, impaired spatial and recognition memories, and prolonged the activation of adrenocorticotropic hormone (ACTH) and glucocorticoids (CORT) following new acute stress. Taken together, these results indicate that stress may trigger two distinctive neurobehavioral systems, depending on both of the intensity of stress and the CCKergic tone in the brain. A “threshold theory” for this two-behavior system has been suggested

A University Forests lecture for HUSTEP (Hokkaido University Short-Term Exchange Program) on the ancient forest culture of Hokkaido University campus

Introduction:Hokkaido University campus has been designated a National Archelogical Site (K39 Site and K435 Site)(Yoshiwaki 1986, Kosugi 2003, 2005, 2008). Therefore, there there are many excavations related to ancient vegatation, such as seeds, pollen fossil, wooden tools and charred wood. These excavation allow us to estimate ancient forest vegetation and the wood utilization of ancient people who lived in the area of what is now Hokkaido University campus. Watanabe et al. (2005), the first author, has been identifying the buried ancient woods found at sites on Hokkaido University campus since 2003. The results, including charred wood, have been reported in archeological excavation reports. However, no one has summarized these results in relation to wood identification and pollen fossil analysis, or systematically organized the date concerning the ancient forest culture, i.e., ancient forest vegetation and wood utilization of ancient people who lived in the area of Hokkaido University. To clarify the ancient forest culture is important because it can lead to an understanding of how ancient people managed forests and we may learn from them forest managemanet techniques suitable for the current global climate changes. Hokkaido University Forests has developed a course on "Environmental Science for Biological Resources" as a part of "Hokkaido University Short Term Exchange Program", HUSTEP(Sasa and Koike 2002, Koike et al. 2006, 2007). To introduce "Ancient Forest Culture" of Hokkaido University campus, we created panels that summarize the results of the wood identification and pollen fossil analysis using the accumulated archeological data from excavations on Hokkaido University campus

A contribution of the University Forests to a lecture HUSTEP (Hokkaido University Short-Term Exchange Program) : Development of Eco-Campus through creating name plates of tree species

Introduction: Hokkaido University has the largest experimental forest in the world belonging to one university with several advanced facilities and an ecologically well-managed campus. We have been developing lectures on field science as part of the Hokkaido University Short-Term Exchange Program (HUSTEP) through creatin nameplates of trees (including their ecology, utilization and origin of their name, ets.). The instigation for the creation of new lectures on field science (Environmental Science for Bilolgical Resources) was serious environmental changes due to rapid economic development in Northeast Asia. Under these environmental changes, conservation of biodiversity in forests is a very important issue for future generations, We will be able to solve these environmental problems only when we forge international cooperation in environmental health services. Hokkaido University, located in Northeast Asia, should be engaged in environmental science education as well as forest technology.Hokkaido University Forests have been development a lecture on "Environmental Science for Biological Resources" as a contribution to the development of HUSTEP. The goal of the lecture is to encourage HUSTEP students to study in East Asia where we have the highest biodiversity. Students will be able to recognize species rich forests and campus in Far East. We also show the students that we have been using wood resources following the traditional methods of the Ainu, the indienous people of northern Japan. However, we need a reasonable mathod for imparting the traditional methods of the Ainu as well as sustainable use of wood resources to the students. For these reasons, we have established nameplates of representative tree species, which includes information about their ecology and utilization methods for HUSTEP education, with the ultimate aim of improving education at Hokkaido University. The objective of this document is to improve the HUSTEP lectures through the introduction of the contents and locations of the tree nameplates on the campus