488 research outputs found
Recommended from our members
Preliminary study of discrimination of human vocal commands in walrus (Odobenus rosmarus divergens)
Walruses seem to use various acoustic signals in social context. So, the auditory faculty is seems to be important for walruses. Can walruses understand another animals' vocal information using auditory sense? This study tested whether a male walrus could discriminate human vocal words and perform different actions corresponding to each one under various conditions. The subject, a male walrus (Odobenus rosmarus) named Pou, was set on the ground, and the experimenter spoke one of the ten words to the subject under the following conditions; (1) The experimenter stood close to the subject and spoke each vocal stimulus wearing a black cloak and goggles so that the experimenter's eye and body movements would not influence the subject's behavior, (2) A wooden board was placed between the experimenter and the subject so that the subject could not see the experimenter, (3) A wooden board was placed between the experimenter and the subject so that the subject could not to see the experimenter, and the experimenter uttered each vocal stimulus through an audio speaker. Under each condition, when the subject performed the correct action corresponding to the vocal stimulus, he was rewarded with a piece of fish. As a result, the subject responded correctly to almost all the human vocal stimuli in every condition, including when the speaker was not visible. This means that he was indeed responding to the vocal words and not the experimenter's cues. This study demonstrated that walruses can hear and identify human vocal words using their auditory sense and can form correspondence between vocal words and their meanings
The mapping class group and the Meyer function for plane curves
For each d>=2, the mapping class group for plane curves of degree d will be
defined and it is proved that there exists uniquely the Meyer function on this
group. In the case of d=4, using our Meyer function, we can define the local
signature for 4-dimensional fiber spaces whose general fibers are
non-hyperelliptic compact Riemann surfaces of genus 3. Some computations of our
local signature will be given.Comment: 24 pages, typo adde
High-resolution NMR-based metabolic detection of microgram biopsies using a 1 mm HRμMAS probe
International audienceA prototype 1 mm High-Resolution micro-Magic Angle Spinning (HRμMAS) probe is described. High quality 1 H NMR spectra were obtained from 490 μg of heterogeneous biospecimens, offering a rich-metabolite profiling. The results demonstrate the potential of HRμMAS as a new NMR analytical tool in metabolomics. Today 1 H HRMAS (High-Resolution Magic-Angle Spinning) NMR (Nuclear Magnetic Resonance) spectroscopy finds great success in laboratory studies of the metabolome in heterogeneous biospecimens such as human and animal biopsies, 1–3 intact cells 4 and whole organisms, 5,6 owing to the nearly non-destructive nature of the technique and the straightforward data acquisition. 7 However, since NMR spectroscopy is an inherently insensitive analytical technique, HRMAS relies on a large sample mass, typically 10–20 mg per NMR data. For this reason, 1 H HRMAS analysis can be a real challenge (or even impossible) when samples – such as cells, organisms and tissue biopsies – are scarce. Moreover, analysis of 10–20 mg of heterogeneous specimens may prevent the investigation of a specific cell. In contrast, the high degree of homogeneity inside a microscopic specimen can offer a more direct NMR spectral analysis and enable a straightforward metabolic evaluation. The immediate advantages of small sample mass (i.e. microgram) analyses are: (1) they simplify the sample preparations such as cultivation and extraction; and (2) offer precise specimen-specific analyses for exploring the invisible phenotypes. The most cost-effective approach to microscopic NMR detection is the use of a miniature detection coil (μcoil). With this technique, the coil is in close proximity to the microscopic sample optimizing the filling-factor (the ratio of the sample volume to the coil detection volume). 8 Fabricating a μcoil for HRMAS analyses is no easy task, especially without sacrificing detection sensitivity and spectral resolution. 9 The commercial μMAS systems currently available (i.e. 0.7 mm Bruker MAS and 0.75 mm JEOL MAS) are designed for solid materials but do not offer adequate spectral resolution (0.002 ppm) for metabolic investigations. Today, the only approach to μMAS for metabolome analyses is the use of an inductively coupled High-Resolution Magic-Angle Coil Spinning (HRMACS) μcoil. 10 The HRMACS technique uses a secondary tuned circuit (i.e. μcoil-resonator), designed to fit inside a standard 4 mm MAS rotor, to convert the standard large volume MAS system into a high-resolution capable μMAS probe. 11,12 The use of HRMACS has show
Clinical efficacy of intermittent pressure augmented–retrograde cerebral perfusion
ObjectiveDuring aortic surgery under hypothermic circulatory arrest, retrograde cerebral perfusion (RCP) is commonly used as a cerebroprotective method to extend the duration of circulatory arrest safely. Kitahori and colleagues described a novel protocol of RCP using intermittent pressure augmented (IPA)–RCP in 2005. The aim of the present study was to determine the clinical effectiveness of this novel protocol.MethodsA total of 20 consecutive patients undergoing total replacement of the aortic arch were assigned to a conventional RCP (n = 10) or an IPA-RCP group (n = 10). Cerebral perfusion was provided at a continuous venous pressure of 25 mm Hg in the conventional RCP, and venous pressure was intermittently provided at 20 mm Hg for 120 seconds and at 45 mm Hg for 30 seconds in the IPA-RCP group. The clinical outcomes were compared between the 2 groups. Regional cerebral oxygen saturation (rSO2) was measured using near infrared spectroscopy every 10 minutes from the beginning of RCP initiation. To represent the brain oxygen consumption, the decline ratio of rSO2 was calculated.ResultsThere was no surgical mortality or major neurologic complications in either group. The interval from the end of surgery to full wakefulness was significantly shorter in the IPA-RCP group (85 ± 64 minutes) than in the conventional RCP group (310 ± 282 minutes; P < .05). Although the initial rSO2 value did not show significant difference in both groups, the rSO2 with IPA-RCP was greater than that with conventional RCP from 10 to 70 minutes (P < .05). The decline ratio of rSO2 was lower in the IPA-RCP group than in the RCP perfusion group at all points (P < .05).ConclusionsIPA-RCP might provide more homogenous cerebral perfusion and a more effective oxygen supply to the brain with better clinical results than conventional RCP
Intraarticular lengths of double-bundle grafts can change during knee flexion: Intraoperative measurements in anatomic anterior cruciate ligament reconstructions
Background: The lengths of the anteromedial bundle (AMB) and posterolateral bundle (PLB) change during knee motion during double-bundle anterior cruciate ligament (ACL) reconstruction. However, the actual intraarticular graft length would be affected by the bone tunnel position and tunnel creation angle during ACL reconstruction. The aim of this study was to investigate the intraarticular length change of the AMB and PLB in patients who underwent anatomic double-bundle ACL reconstruction.
Hypothesis: We hypothesized that the PLB would show a more dynamic length change pattern than the AMB during knee flexion at ACL reconstruction.
Methods: Thirty-two patients (16 men and 16 women) who had isolated ACL injuries with intact menisci were investigated. Anatomic double-bundle ACL reconstructions were performed using semitendinosus tendon autografts at a mean age of 30.6 years. The graft and tunnel lengths were measured intraoperatively. Intraarticular graft lengths and length changes were calculated at 0˚ and 90˚ of knee flexion during ACL reconstruction. Intraoperative data were collected prospectively, and analyses were performed retrospectively.
Results: The intraarticular length of the AMB at 0˚ of knee flexion was 28.1 ± 5.5 mm. At 90˚ of knee flexion, the AMB intraarticular length decreased to 25.6 ± 4.8 mm. The intraarticular length of the PLB decreased to 17.7 ± 4.6 mm at 90˚ of knee flexion compared to 22.0 ± 4.2 mm at 0˚ of knee flexion. Changes in the intraarticular graft length during knee flexion were detected more in the PLB (4.1 mm) than in the AMB (2.0 mm, P = 0.01).
Discussion: This study demonstrated that the intraarticular length change of the PLB during knee motion was larger than that of the AMB in anatomic double-bundle ACL reconstructions with semitendinosus tendon autografts and suspensory femoral fixation devices
Local Gene Delivery System by Bubble Liposomes and Ultrasound Exposure into Joint Synovium
Recently, we have developed novel polyethylene glycol modified liposomes (bubble liposomes; BL) entrapping an ultrasound (US) imaging gas, which can work as a gene delivery tool with US exposure. In this study, we investigated the usefulness of US-mediated gene transfer systems with BL into synoviocytes in vitro and joint synovium in vivo. Highly efficient gene transfer could be achieved in the cultured primary synoviocytes transfected with the combination of BL and US exposure, compared to treatment with plasmid DNA (pDNA) alone, pDNA plus BL, or pDNA plus US. When BL was injected into the knee joints of mice, and US exposure was applied transcutaneously to the injection site, highly efficient gene expression could be observed in the knee joint transfected with the combination of BL and US exposure, compared to treatment with pDNA alone, pDNA plus BL, or pDNA plus US. The localized and prolonged gene expression was also shown by an in vivo luciferase imaging system. Thus, this local gene delivery system into joint synovium using the combination of BL and US exposure may be an effective means for gene therapy in joint disorders
- …