510 research outputs found

    Almost alternating diagrams and fibered links in S^3

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    Let LL be an oriented link with an alternating diagram DD. It is known that LL is a fibered link if and only if the surface RR obtained by applying Seifert's algorithm to DD is a Hopf plumbing. Here, we call RR a Hopf plumbing if RR is obtained by successively plumbing finite number of Hopf bands to a disk. In this paper, we discuss its extension so that we show the following theorem. Let RR be a Seifert surface obtained by applying Seifert's algorithm to an almost alternating diagrams. Then RR is a fiber surface if and only if RR is a Hopf plumbing. We also show that the above theorem can not be extended to 2-almost alternating diagrams, that is, we give examples of 2-almost alternating diagrams for knots whose Seifert surface obtained by Seifert's algorithm are fiber surfaces that are not Hopf plumbing. This is shown by using a criterion of Melvin-Morton.Comment: 18 pages, 30 figure

    Factors Influencing Home Death in a Japanese Metropolitan Region

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    To examine factors influencing home death, an anonymous survey was mailed to 998 home care supporting clinics (HCSCs) in the 23 wards of Tokyo, Japan. We classified the HCSCs into two types (single physician practice and multiple physician practice) and identified factors of each type of practice that predict home death. The factors associated with a greater probability of dying at home were as follows: in the multiple physician practices, collaboration with hospitals and teaching coping skills to the family members and, in the single physician practices, collaboration with clinics. Our findings suggest that home end-of-life care services are unlikely to be achieved without cooperation among service providers and without improvement of the family members' coping skills

    Intertrochanteric fracture classification

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    A novel three-dimensional fragment-based classification system based on computed tomography findings was established to characterize femoral intertrochanteric fractures. The intertrochanteric bone fragments were defined as follows : neck, posterior portion of the greater trochanter, anterior portion of the greater trochanter, lesser trochanter, and shaft. Each type of fracture was classified as 2-, 3-, 4-, or 5-fragment according to the number of floating bone fragments. Following the description of the fracture type, each floating bone fragment was appended, with the exception of a fragment involving the shaft. Ninety-five intertrochanteric fractures were classified by the same surgeon. The fractures occurred in 14 men and 81 women with a mean age of 84.7 years. The frequency of each type of fracture was investigated. Thirty-one fractures (32.6%) were 2-fragment and 64 (67.4%) were ≄ 3-fragment. A fragment of the anterior portion of the greater trochanter, which cannot be classified using conventional systems, was included in 29 cases (30.5%). A 5-fragment fracture was detected in two cases (2.1%). Using this fragment-based classification system, intertrochanteric fractures can be evaluated in more detail than is possible using conventional classification systems

    Effect of baseplate position on locking screws

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    Introduction : Superior screw insertion in reverse shoulder arthroplasty (RSA) carries the potential risk of suprascapular injury. The purpose of this study was to evaluate how the baseplate position affects the superior screw position and length in RSA. Methods : Three-dimensional (3D) computer simulation models of RSA were established using computed tomography data of baseplates with superior and inferior screws and 3D scapular models from 10 fresh cadavers. Superior screw position, the distance from the superior screw hole to the suprascapular notch, and the screw lengths were measured and compared among various baseplate positions with two inferior tilts (0 and 10 degrees) and three rotational patterns (11–5, 12–6, and 1–7 o’clock in the right shoulder). Results : For the 1–7 o’clock / inferior tilt 0 degrees baseplate, the superior screw located anterior to the SS notch in all shoulders, the distance to the SS notch was the longest (12.8 mm), and the inferior screw length was the shortest (23.1 mm). Conclusion : Although there is a concern of a short inferior screw length, initial fixation using a baseplate with 1–7 o’clock rotation and an inferior tilt of 0 degrees appears preferable for SS nerve injury prevention during superior screw insertion

    Effectiveness of outpatient-based group cognitive-behavioral therapy in Japanese patients with mood disorders and neurotic disorders

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    Background: Although the effectiveness of group cognitive-behavioral therapy (GCBT) has been studied, evidence is still not sufficient. Objective: The aim of the present study is to consider the effectiveness of GCBT with mood disorders and neurotic disorders. Methods: The present study assessed a total of 32 patients who were classified as F3 (mood disorders) or F4 (neurotic disorders) according to the ICD-10, and who attended GCBT sessions offered at The Tokai University Hospital. Depression and mood in these patients were assessed before and after GCBT by using the Center for Epidemiologic Studies Depression Scale (CES-D) and the Profile of Mood States (POMS). Results: A comparison of pre- and post-GCBT CES-D scores among all patients as well as within F3 and F4 groups showed a significant decrease in CES-D scores after GCBT. As for the POMS, a comparison of pre- and post-GCBT scores among all patients showed a significant improvement in “vigor” and “confusion” scores after GCBT. Discussion: The present study demonstrated that GCBT can relieve depression and improve some mood states. Furthermore, the GCBT sessions offered proved to be effective even when administered to a group of participants consisting of both mood disorders and neurotic disorder patients

    How to Carry Out Bathymetric and Elevation Surveys on a Tight Budget: Basic Surveying Techniques for Sustainabilty Scientists

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    Sustainability scientists often face a difficult task to conduct research or carry out preliminary investigations around coastal areas in developing countries, due to the limitation in the availability of topographical and bathymetry data. These limitations can be particularly important for the case of ports, on which the livelihoods of many fishing communities depend on. Often, cost is cited as a reason regarding the absence of any such data. However, in the present technical note the authors highlight how existing “low-level” surveying methods can be inexpensive and allow sustainability scientists to conduct a reasonably accurate survey for less than 1,000 USD, provided that researchers possess a reasonable knowledge of mathematics and geometry (high-school equivalent)

    An Efficiency Degradation Model of Power Amplifier and the Impact against Transmission Power Control for Wireless Sensor Networks

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    Abstract—To extend an available period of wireless sensor networks, transmission power control is regarded as one of the promising schemes. In most of the previous studies on the transmission power control, it is assumed that a transmitter has power consumption of O(dn), where d and n denote a maximum communication distance and a pass loss factor. This assumption would substantially hold under the condition that the transmission efficiency is always constant at any transmission power (efficiency-fixed model). In practice, however, the trans-mission efficiency degrades as the transmission power is reduced. We analytically verify that an actual power amplifier with the efficiency degradation has a power consumption of O(dr), where n/2.8 ≀ r ≀ n/2 (efficiency-degradation model). The efficiency-degradation model gives the negative impact against the transmission power control. Index Terms—Wireless sensor network, transmission power control, transmission efficiency, pass loss factor. I
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