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CST–Polα/Primase maintains telomeres through fill-in synthesis of the C-rich telomeric DNA. We report cryo-EM structures that reveal how human CST is recruited to telomeres by the shelterin subunits POT1 and TPP1. CST–POT1/TPP1 is formed through interactions between POT1 and the Ctc1 subunit of CST. Coats plus syndrome mutations map to the POT1–Ctc1 interface, providing mechanistic insights into this disease. CST–POT1/TPP1 is compatible with the previously reported inactive recruitment complex of CST–Polα/Primase but not with the distinct conformation of active CST–Polα/Primase. We propose that shelterin both recruits and regulates CST–Polα/Primase. Structural and biochemical data indicate that this regulation involves phosphorylation of POT1, which promotes CST–POT1/TPP1 interaction and recruitment, whereas POT1 dephosphorylation releases CST–Polα/Primase for fill-in synthesis.One-Sentence SummaryCryo-EM structures reveal how telomere maintenance factors are recruited and regulated by the shelterin complex.

Although carotid endarterectomy (CEA) is an established procedure, technical modifications are required when anatomical features are unusual. The present study aimed to determine the characteristics of diagnostic features, surgical management, and outcomes of patients with a twisted carotid bifurcation (TCB). We assessed 108 consecutive patients by cervical carotid echography (CCE) and black-blood magnetic resonance imaging (BB-MRI) before they underwent 115 CEA procedures. We classified carotid bifurcation (CB) anatomy based on anteroposterior findings of the internal carotid artery (ICA) and external carotid artery (ECA) determined by cerebral or three-dimensional computed tomographic angiography as follows. The ICA and ECA ran laterally and medially, respectively, in Type 1, overlapped in Type 2, and the ICA and ECA ran medially and laterally, respectively, in Type 3. We also classified the patients according to whether or not they had a TCB and compared their diagnostic findings, clinical characteristics, and surgical outcomes. The numbers of patients with Types 1, 2, and 3 were 74 (64.4%), 32 (27.8%), and 9 (7.8%), respectively, and 13 (11.3%) with a TCB included four patients with Type 2 and all nine patients with Type 3. The appearance of Type 3 differed from that of the other two types on CCE and BB-MR images. After correcting the anatomical location of a TCB, surgical duration and adverse event rates did not significantly differ between patients with and without a TCB. Patients with a TCB could safely undergo CEA after correcting the ICA to the normal position.

In DNA repair, the resection of double-strand breaks dictates the choice between homology-directed repair—which requires a 3′ overhang—and classical non-homologous end joining, which can join unresected ends1,2. BRCA1-mutant cancers show minimal resection of double-strand breaks, which renders them deficient in homology-directed repair and sensitive to inhibitors of poly(ADP-ribose) polymerase 1 (PARP1)3–8. When BRCA1 is absent, the resection of double-strand breaks is thought to be prevented by 53BP1, RIF1 and the REV7–SHLD1–SHLD2–SHLD3 (shieldin) complex, and loss of these factors diminishes sensitivity to PARP1 inhibitors4,6–9. Here we address the mechanism by which 53BP1–RIF1–shieldin regulates the generation of recombinogenic 3′ overhangs. We report that CTC1–STN1–TEN1 (CST)10, a complex similar to replication protein A that functions as an accessory factor of polymerase-α (Polα)–primase11, is a downstream effector in the 53BP1 pathway. CST interacts with shieldin and localizes with Polα to sites of DNA damage in a 53BP1- and shieldin-dependent manner. As with loss of 53BP1, RIF1 or shieldin, the depletion of CST leads to increased resection. In BRCA1-deficient cells, CST blocks RAD51 loading and promotes the efficacy of PARP1 inhibitors. In addition, Polα inhibition diminishes the effect of PARP1 inhibitors. These data suggest that CST–Polα-mediated fill-in helps to control the repair of double-strand breaks by 53BP1, RIF1 and shieldin.

Coats plus (CP) can be caused by mutations in the CTC1 component of CST, which promotes polymerase α (polα)/primase-dependent fill-in throughout the genome and at telomeres. The cellular pathology relating to CP has not been established. We identified a homozygous POT1 S322L substitution (POT1CP) in two siblings with CP. POT1CP induced a proliferative arrest that could be bypassed by telomerase. POT1CP was expressed at normal levels, bound TPP1 and telomeres, and blocked ATR signaling. POT1CP was defective in regulating telomerase, leading to telomere elongation rather than the telomere shortening observed in other telomeropathies. POT1CP was also defective in the maintenance of the telomeric C strand, causing extended 3′ overhangs and stochastic telomere truncations that could be healed by telomerase. Consistent with shortening of the telomeric C strand, metaphase chromosomes showed loss of telomeres synthesized by leading strand DNA synthesis. We propose that CP is caused by a defect in POT1/CST-dependent telomere fill-in. We further propose that deficiency in the fill-in step generates truncated telomeres that halt proliferation in cells lacking telomerase, whereas, in tissues expressing telomerase (e.g., bone marrow), the truncations are healed. The proposed etiology can explain why CP presents with features distinct from those associated with telomerase defects (e.g., dyskeratosis congenita).

In this article, we propose MAC protocols based on our infrared-space division transceiver (IR-SDT) for mobile robots. The IR-SDT has eight communication modules, so it can communicate with a maximum of eight other nodes simultaneously. The number of parallel multiple accesses will be improved by using this transceiver and its specialized protocol. In addition, we consider situations in which a packet collision occurs, and propose a protocol that resolves communication conflicts using the signal collision-detection function of IR-SDT. Finally, we consider the performance of these protocols, and discuss the influence of signal collision-detection accuracy.

TEL2 interacts with and is essential for the stability of all phosphatidylinositol 3-kinase-related kinases (PIKKs), but its mechanism of action remains unclear. Here, we show that TEL2 is constitutively phosphorylated on conserved serines 487 and 491 by casein kinase 2 (CK2). Proteomic analyses establish that the CK2 phosphosite of TEL2 confers binding to the R2TP/prefoldin-like complex, which possesses chaperon/prefoldin activities required during protein complex assembly. The PIH1D1 subunit of the R2TP complex binds directly to the CK2 phosphosite of TEL2 in vitro and is required for the TEL2-R2TP/prefoldin-like complex interaction in vivo. Although the CK2 phosphosite mutant of TEL2 retains association with the PIKKs and HSP90 in cells, failure to interact with the R2TP/prefoldin-like complex results in instability of the PIKKs, principally mTOR and SMG1. We propose that TEL2 acts as a scaffold to coordinate the activities of R2TP/prefoldin-like and HSP90 chaperone complexes during the assembly of the PIKKs.

We reported previously that the stability of all mammalian phosphatidylinositol 3-kinase-related protein kinases (PIKKs) depends on their interaction with Tel2, the ortholog of yeast Tel2 and Caenorhabditis elegans Clk-2. Here we provide evidence that Tel2 acts with Hsp90 in the maturation of PIKK complexes. Quantitative immunoblotting showed that the abundance of Tel2 is low compared with the PIKKs, and Tel2 preferentially bound newly synthesized ATM, ATR, mTOR, and DNA-PKcs. Tel2 complexes contained, in addition to Tti1–Tti2, the Hsp90 chaperone, and inhibition of Hsp90 interfered with the interaction of Tel2 with the PIKKs. Analysis of in vivo labeled nascent protein complexes showed that Tel2 and Hsp90 mediate the formation of the mTOR TORC1 and TORC2 complexes and the association of ATR with ATRIP. The structure of yeast Tel2, reported here, shows that Tel2 consists of HEAT-like helical repeats that assemble into two separate α-solenoids. Through mutagenesis, we identify a surface patch of conserved residues involved in binding to the Tti1–Tti2 complex in vitro. In vivo, mutation of this conserved patch affects cell growth, levels of PIKKs, and ATM/ATR-mediated checkpoint signaling, highlighting the importance of Tti1–Tti2 binding to the function of Tel2. Taken together, our data suggest that the Tel2–Tti1–Tti2 complex is a PIKK-specific cochaperone for Hsp90.

In recent years, multiple robot systems that perform team operations have been developed. These robot systems are expected to execute complicated tasks smoothly in a given congested workspace. In this article, we propose a workspace mapping algorithm using ultrasonic stereo sonar and an image sensor in order to operate the mobile robots among obstacles. This workspace mapping algorithm involves two steps: (1) the position detection of obstacles using ultrasonic stereo sonar, and (2) the shape detection of obstacles using an image sensor. While each robot moves around in the given workspace, the two steps of the mapping algorithm are repeated and sensor data are collected. The robot measures the distance and the direction of obstacles using ultrasonic stereo sonar. The shape of obstacles is also captured using an onboard image sensor. A workspace map is created based on the sensor data accumulated from the proposed method, and successful results are also obtained through experiments.

Numerically controlled local wet etching is a novel figuring method for fabricating the ultraprecision optical components and/or finishing the functional materials. In this method, localized wet etching area is formed by applying the combination nozzle which consists of a supply part and a suction part of an etchant, and the removal volume at any point on the workpiece surface is determined by the dwelling time of the nozzle. In this paper, we proposed the two-step figuring process, which consists of a rough figuring process by applying a one-dimensional numerically controlled scanning using a large rectangular nozzle and a finishing process by applying two-dimensional numerically controlled scanning using a small circular nozzle, for figuring the plano-aspherical mirror. By applying the two-step figuring process, we fabricated the plano-elliptical neutron focusing mirror with the figure accuracy of less than 0.5 µm and succeeded in achieving the focusing gain of 6.

Numerically controlled local wet etching (NC-LWE) is a novel figuring method for fabricating the ultraprecision optics or finishing the functional materials. In this method, the localized etching area is formed by applying the combination nozzle that is constructed from the supply part and the suction part of the etchant, and the removal volume anywhere on the workpiece surface is determined by the dwelling time of the nozzle. We applied the NC-LWE for fabricating the piano-elliptical mirror made of synthesized quartz glass to focus the hard X-ray beam, and achieved a figure error of 27 nm (p-v) by applying a 1-dimensional numerically controlled figuring utilizing a square-shaped nozzle.

The acrosome reaction of newt sperm is induced at the surface of egg jelly and the acrosome-reacted sperm acquire the ability to bind to the vitelline envelope. However, because the substance that induces the acrosome reaction has not been identified, the mechanism by which the acrosome-reacted sperm bind to the vitelline envelope remains unclear. We found here that a Dolichos biforus agglutinin (DBA) specifically mimicked the acrosome reaction immediately upon its addition in the presence of milimolar level Ca2+. Fluorescein isothiocyanate-labeled DBA bound specifically to the acrosomal cap of the intact sperm in the presence of a Ca2+-chelating agent, EDTA, suggesting that binding of DBA to the native receptor for the egg jelly substance on the acrosomal region took the place of the egg jelly substance-induced acrosome reaction. In contrast, the sperm that had been acrosome reacted by DBA treatment did not bind to the vitelline envelope of the egg whose jelly layers were removed. Subsequent addition of jelly extract caused the sperm binding to vitelline envelope, indicating that the egg jelly of the newt contains substances that are involved in not only inducing the acrosome reaction but also binding to the vitelline envelope. This is the first demonstration of the involvement of egg jelly substance in the binding of acrosome-reacted sperm to the vitelline envelope. J. Exp. Zool. 307A:301–311, 2007. © 2007 Wiley-Liss, Inc.

SummaryHuman telomeres are protected by shelterin, a complex that includes the POT1 single-stranded DNA binding protein. We found that mouse telomeres contain two POT1 paralogs, POT1a and POT1b, and we used conditional deletion to determine their function. Double-knockout cells showed that POT1a/b are required to prevent a DNA damage signal at chromosome ends, endoreduplication, and senescence. In contrast, POT1a/b were largely dispensable for repression of telomere fusions. Single knockouts and complementation experiments revealed that POT1a and POT1b have distinct functions. POT1a, but not POT1b, was required to repress a DNA damage signal at telomeres. Conversely, POT1b, but not POT1a, had the ability to regulate the amount of single-stranded DNA at the telomere terminus. We conclude that mouse telomeres require two distinct POT1 proteins whereas human telomeres have one. Such divergence is unprecedented in mammalian chromosome biology and has implications for modeling human telomere biology in mice.

The ventricular septum receives its blood supply from the septal perforators of the left anterior descending (LAD) coronary artery and the right coronary artery. However, when the LAD artery extends to the inferior wall, beyond the apex (so-called wrapped LAD), the ventricular septum near the apex receives blood supply only from the LAD artery. As a consequence, ventricular septal rupture (VSR) would seem more likely in myocardial infarction with occlusion of this type of LAD artery. To test this hypothesis, we compared electrocardiographic findings in 21 patients who had anterior acute myocardial infarction that was complicated by VSR with those in 275 patients who had acute myocardial infarction that was not complicated by VSR. We observed ST-segment elevation in all inferior leads (II, III, and aVF) in addition to anterior leads in 42.9% of patients (9 of 21) who had VSR but in only 3.6% of those (10 of 275) who did not have VSR. Abnormal Q waves appeared in all 3 inferior leads in 44.4% of patients (8 of 18) who had VSR but in only 4.0% of those (10 of 250) who did not have VSR. Thus, the incidence of ST-segment elevation and abnormal Q waves in the inferior leads was significantly (p

This paper presents a space-division wireless communication system for nonhierarchical, cooperative control of multiple mobile robots. The proposed communication system has the following features: 1) it has a set of infrared transceivers arranged on the circumference of the robot body to communicate in all directions; 2) it can maintain communication links by exchanging transceivers when either of the robots runs and/or rotates. An arbiter is introduced to reduce communication interference when two or more robots are in the same communication area. Adhoc communication networks are constructed based on the selection of arbiters. As an example of distributed sensing and cooperation using the system, cooperative localization of communicating mobile robots is also described. Some performance measurements using an experimental system have been carried out to show the viability of the proposed approach.

We report on the function of the human ortholog of Saccharomyces cerevisiae Rif1 (Rap1-interacting factor 1). Yeast Rif1 associates with telomeres and regulates their length. In contrast, human Rif1 did not accumulate at functional telomeres, but localized to dysfunctional telomeres and to telomeric DNA clusters in ALT cells, a pattern of telomere association typical of DNA-damage-response factors. After induction of double-strand breaks (DSBs), Rif1 formed foci that colocalized with other DNA-damage-response factors. This response was strictly dependent on ATM (ataxia telangiectasia mutated) and 53BP1, but not affected by diminished function of ATR (ATM- and Rad3-related kinase), BRCA1, Chk2, Nbs1, and Mre11. Rif1 inhibition resulted in radiosensitivity and a defect in the intra-S-phase checkpoint. The S-phase checkpoint phenotype was independent of Nbs1 status, arguing that Rif1 and Nbs1 act in different pathways to inhibit DNA replication after DNA damage. These data reveal that human Rif1 contributes to the ATM-mediated protection against DNA damage and point to a remarkable difference in the primary function of this protein in yeast and mammals.

Electronic structures near the Fermi level of polymer/1T-LixTaS2 layered nanocomposites have been studied by tunnelling spectroscopy. Polymer/1T-LixTaS2 layered nanocomposites were synthesized by using the exfoliation–adsorption technique. Single crystals of 1T-TaS2 were used as host materials. Poly(ethylene oxide) (PEO) and poly(ethylenimine) (PEI) with different molecular weights were adopted as guest intercalants. Powder x-ray diffraction patterns showed that all samples of the polymer/1T-LixTaS2 layered nanocomposites contain organic polymer between all individual 1T-TaS2 sheets. Although 1T-TaS2 single crystal is well known to show quite unique temperature dependences of the resistivity due to the charge density wave (CDW), the resistivities of all polymer/1T-LixTaS2 nanocomposites showed semiconductor-like temperature dependences. The tunnelling spectra of polymer/1T-LixTaS2 nanocomposites revealed that the CDW gap disappears in the density of states near the Fermi level of polymer/1T-LixTaS2 nanocomposites and their electronic structures show a metallic behaviour.

The purposes of this study are to develop the support system to the traffic accidents in one case visually, to provide detailed information, to analyze various traffic accident occurrence conditions by the factors and to accumulate the traffic accident data for a long term. This system is the basic system to predict a future traffic accident occurrence and to effect on improvement countermeasures. This system is also able to indicate the traffic accident occurrence points on one sheet of map and also to indicate the details by the zoom function.

This paper presents a space-division optical wireless inter-robot communication system for multiple mobile robots. Infrared optical wireless communication is suitable for the mobile robots, because of its low level of interference in multiple directions. However, optical wireless communication is lost when either of the robots runs and/or rotates due to the nature of infrared rays. The proposed communication system has a set of infrared transceivers, which face all directions. The system can maintain circuit connections by exchanging transceivers. Furthermore it can communicate at the same time with more than one robot in different positions by using different transceivers. Spontaneous construction of inter-robot communication networks based on the selection of arbiters is described. As an example of local sensing capabilities of the system, mutual localization using transceivers on three communicating robots is also described. Hardware realization and performance measurements are illustrated to reveal the effectiveness of the proposed system.

BACKGROUND Warfarin reduces the risk of stroke in patients with atrial fibrillation, but requires a moderate-to-high time in therapeutic range (TTR). We hypothesized that point-of-care (POC) testing for prothrombin time-internationalized normalized ratio (PT-INR) could improve the TTR in patients receiving warfarin. METHODS AND RESULTS Eight outpatient clinics that introduced POC testing for PT-INR participated in this study. We identified 148 consecutive patients who received warfarin for at least 12 months before and after the introduction of POC testing. We compared the TTR before and after the introduction of POC testing for each patient. TTR after the introduction of POC testing was significantly higher than that beforehand (51.9%±33.0% vs. 69.3%±26.3%; P

This paper presents a sensor fusion based intelligent motion control scheme for nonholonomic wheeled mobile robots under unstructured environments. The proposed scheme is composed of path planning and tracking control modules, considering kinematic constraints in steering control of nonholonomic vehicles. First, the path planning module generates an obstacle-free short path as a sequence of control vectors of orientation using a genetic algorithm. Then, the tracking control module produces the references for steering control using a sensor fusion network. Simulations of path planning and preliminary experiments with internal and external sensors are presented to show the effectiveness of the proposed control scheme

This paper presents a space-division optical wireless inter-robot communication system for multiple mobile robots. Infrared optical wireless communication is suitable for the mobile robots, because of its low level of interference in multiple directions. However, optical wireless communication is lost when either of the robots runs and/or rotates due to the nature of infrared rays. The proposed communication system has many infrared transceivers, which face all directions. The system can maintain circuit connections by exchanging transceivers. Furthermore it can communicate at the same time with more than one robot in different positions by using different transceivers. As an example of local sensing capabilities of the system, mutual localization using transceivers on three communicating robots is also described. Hardware realization and performance measurements are illustrated to reveal the effectiveness of the proposed system.

This paper describes the realization of a space-division optical communication system specifically designed to perform local inter-robot communication in fully distributed multiple autonomous mobile robot systems. Requirements for autonomy and robustness of communication functions among moving robots are discussed. The communication system uses a set of modules, or transceivers, which is arranged in the circumference of the robot body. Each module comprises an IR detector/receiver and an IR transmitter. Each IR module detects the angle of incidence of infrared rays. Space-division communication networks can be created, because a robot can commumcate with more than one robot through different modules at the same time. Hardware realization and performance measurements are illustrated to reveal the effectiveness of the developed system.

This paper presents a control scheme for intelligent motion control of nonholonomic wheeled mobile robots under unstructured environments. First, using a simple genetic algorithm, the path planning module calculates an obstacle-free path as a sequence of control vectors of orientation, considering kinematic constraints in steering control. Then, the tracking control module calculates the references for motion control of the mobile robot using a sensor fusion neural network. Preliminary experiments for teaching the neural network with internal and external sensors are presented to show the effectiveness of the proposed control scheme.

Estrogen deficiency causes bone loss as a result of accelerated osteoclastic bone resorption. It also has been reported that estrogen deficiency is associated with an increase in the number of pre-B cells in mouse bone marrow. The present study was undertaken to clarify the role of altered B lymphopoiesis and of the receptor activator of nuclear factor-kappa B ligand (RANKL), a key molecule in osteoclastogenesis, in the bone loss associated with estrogen deficiency. In the presence of prostaglandin E2 (PGE2), the activity to form tartrate-resistant acid phosphatase (TRAP)-positive osteoclast-like cells was significantly greater in bone marrow cells derived from ovariectomized (OVX) mice than in those from sham-operated mice. Northern blot analysis revealed that PGE2 increased the amount of RANKL messenger RNA (mRNA) in bone marrow cells, not only adherent stromal cells but nonadherent hematopoietic cells; among the latter, RANKL mRNA was more abundant in OVX mice than in shamoperated mice and was localized predominantly in B220+ cells. Flow cytometry revealed that most B220+ cells in bone marrow were RANKL positive and that the percentage of RANKL-positive, B220low cells was higher in bone marrow from OVX mice than in that from sham-operated mice. The increase in the expression of RANKL and the percentage of these cells in OVX mice was abolished by the administration of indomethacin in vivo. PGE2 also markedly increased both the level of RANKL mRNA and cell surface expression of RANKL protein in the mouse pre-B cell line 70Z/3. Finally, osteoclastogenic response to PGE2 was reduced markedly by prior depletion of B220+ cells, and it was restored by adding back B220+ cells. Taken together with stimulated cyclo-oxygenase (COX)-2 activity by tumor necrosis factor alpha (TNF-alpha) and interleukin-1 (IL-1) in estrogen deficiency, these results suggest that an increase in the number of B220+ cells in bone marrow may play an important role in accelerated bone resorption in estrogen deficiency because B220+ cells exhibit RANKL on the cell surface in the presence of PGE2, thereby leading to accelerated osteoclastogenesis.

The recent discovery of checkpoint kinases has suggested the conservation of checkpoint mechanisms between yeast and mammals. In yeast, the protein kinase Chk1 is thought to mediate signaling associated with the DNA damage checkpoint of the cell cycle. However, the function of Chk1 in mammals has remained unknown. Targeted disruption of Chk1 in mice showed thatChk1−/− embryos exhibit gross morphologic abnormalities in nuclei as early as the blastocyst stage. In culture, Chk1−/− blastocysts showed a severe defect in outgrowth of the inner cell mass and died of apoptosis. DNA replication block and DNA damage failed to arrest the cell cycle before initiation of mitosis inChk1−/− embryos. These results may indicate that Chk1 is indispensable for cell proliferation and survival through maintaining the G2 checkpoint in mammals.

Japanese newt, Cynops pyrrhogaster, undergoes internal fertilization as do most urodeles. In this study, we focused on the roles of egg-jelly in fertilization of C. pyrrhogaster and characterized the substances associated with those roles. When dry sperm were directly inseminated onto the egg, normal fertilization occurred without the presence of water. Egg-jelly extract (JE) prepared with Steinberg's salt solution contained the activity for the initiation of sperm motility. A substance of about 50 kDa in JE was significant for this activity; an inactive form of the substance probably exists in JE. Strong activity to induce acrosome reaction was detected in JE. It was inhibited by the treatment of JE with WGA, suggesting that carbohydrate in JE may be important for the induction of the acrosome reaction. This study suggests that two significant processes of fertilization are regulated by substances in the egg-jelly of the newt, C. pyrrhogaster.

Outer arm dynein was purified from sperm flagella of a sea anemone, Anthopleura midori, and its biochemical and biophysical properties were characterized. The dynein, obtained at a 20S ATPase peak by sucrose density gradient centrifugation, consisted of two heavy chains, three intermediate chains, and seven light chains. The specific ATPase activity of dynein was 1.3 micromol Pi/mg/min. Four polypeptides (296, 296, 225, and 206 kDa) were formed by UV cleavage at 365 nm of dynein in the presence of vanadate and ATP. In addition, negatively stained images of dynein molecules and the hook-shaped image of the outer arm of the flagella indicated that sea anemone outer arm dynein is two-headed. In contrast to protist dyneins, which are three-headed, outer arm dyneins of flagella and cilia in multicellular animals are two-headed molecules corresponding to the two heavy chains. Phylogenetic considerations were made concerning the diversity of outer arm dyneins.

1. In whole-cell patch recording, the relative potency of the blocking action of sematilide on IK1 was found to be constant at each potential level of IK1 activation. Under more acidic condition, the degree of block was decreased. These results strongly suggested that the neutral form of sematilide may penetrate the cardiac cell membrane via hydrophobic pathway. 2. In cell-attached patches, sematilide prolonged the interburst interval and reduced the opening probabilities of the IK1 channel without affecting either the mean open time or the mean closed time within a burst.

Summary Spermatogenesis is a complex process that generates haploid germ cells or spores and implements meiosis, a succession of two special cell divisions that are required for homologous chromosome segregation. During prophase to the first meiotic division, homologous recombination (HR) repairs Spo11-dependent DNA double-strand breaks (DSBs) in the presence of telomere movements to allow for chromosome pairing and segregation at the meiosis I division. In contrast to HR, non-homologous end joining (NHEJ), the major DSB repair mechanism during the G1 cell cycle phase, is downregulated during early meiotic prophase. At somatic mammalian telomeres, the NHEJ factor Ku70/80 inhibits HR, as does the Rap1 component of the shelterin complex. Here, we investigated the role of Ku70 and Rap1 in meiotic telomere redistribution and genome protection in spermatogenesis by studying single and double knockout mice. Ku70−/− mice display reduced testis size and compromised spermatogenesis, whereas meiotic telomere dynamics and chromosomal bouquet formation occurred normally in Ku70−/− and Ku70−/−Rap1Δ/Δ knockout spermatocytes. Elevated mid-preleptotene frequencies were associated with significantly increased DNA damage in Ku-deficient B spermatogonia, and in differentiated Sertoli cells. Significantly elevated levels of γH2AX foci in Ku70−/− diplotene spermatocytes suggest compromised progression of DNA repair at a subset of DSBs. This might explain the elevated meiotic metaphase apoptosis that is present in Ku70-deficient stage XII testis tubules, indicating spindle assembly checkpoint activation. In summary, our data indicate that Ku70 is important for repairing DSBs in somatic cells and in late spermatocytes of the testis, thereby assuring the fidelity of spermatogenesis.

An investigation was performed on the interface control of FRP using glass fiber treated by low temperature plasma. The treatment apparatus was developed in order to control plasma coating onto plain woven glass cloth. Three-point flexural tests of glass fiber reinforced epoxy composites were done by an Instron testing machine in order to examine the effect of the plasma treatment on the composite properties. The main results obtained were as follows:(1) NH3 gas plasma treatment was applied to improve the surface properties of the fiber: The contact angle between distilled water and surface of glass slide, substituted for the glass fiber to measure the contact angle, was decreased by this treatment. And the bending strength of FRP prepared with NH3 plasma treated fiber became higher than the one with the untreated fiber.(2) The bending strength of FRP varied as a function of plasma parameters such as the treatment power and the treatment pressure.(3) The improved adhesion state of the epoxy resin onto the glass fiber after NH3 gas plasma treatment was revealed by the SEM observation of the tensile fracture surface. It can be concluded from these results that the interfacial adhesion and the mechanical interlocking were increased by this process.

One of the most distinctive characteristics of human beings is an ability to walk erect (bipedalism). However, this fact has not been much taken into consideration in designing user-interfaces. In this paper we present real-time recognition of human gait captured by a floor mat device. Two-dimensional continuous dynamic programming, 2DCDP, which is a powerful object recognition algorithm is adapted so that it fits to demands for real-time human gait recognition. Experiments showed that the system is promising towards realization of invisible user interfaces.