37 research outputs found

    Why Did Auction Rate Bond Auctions Fail During 2007-2008?

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    The auction rate bond market grew from inauspicious beginnings in 1985 to representing a significant fraction of the municipal bond market in 2007 with a total of 603 issuances that year raising more than $35 billion in capital. Since March of 2008 not a single auction rate bond has been issued. The last issuance coincided with a wave of “failures” of auction rate bond auctions during the early winter of 2008. Pundits have attributed the auction failures to a “frozen” market and hint that irrationality on the part of investors precipitated the auction failures. Missing from the headlines is that all auction rate bonds have interest rate caps that limit their yields. We find that, contrary to the impression given by news headlines, not all auctions failed and that investors rationally discriminated among bonds such that it was primarily those with low caps that experienced high failure rates. We further conclude that, in the absence of such caps, few if any, auctions would have failed.

    Effects of Shenque Moxibustion on Behavioral Changes and Brain Oxidative State in Apolipoprotein E-Deficient Mice

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    Purpose. To determine whether moxibustion influences the learning and memory behavior of ApoE−/− male mice, and investigate the mechanism of moxibustion on the alteration of oxidized proteins (glial fibrillary acidic protein, β-amyloid) in hippocampus. Methods. Thirty-three ApoE−/− mice were randomly divided into 3 groups (n=11/group): moxibustion, sham moxibustion, and no treatment control. Wild-type C57BL/6 mice n=13 were used for normal control. Moxibustion was performed with Shenque (RN8) moxibustion for 20 minutes per day, 6 days/week for 12 weeks. In sham control, the procedure was similar except burning of the moxa stick. Behavioral tests (step-down test and Morris water maze task) were conducted in the 13th week. The mice were then sacrificed and the tissues were harvested for immune-histochemical staining. Results. In the step-down test, the moxibustion group had shorter reaction time in training record and committed less mistakes compared to sham control. In immune-histochemical study, the moxibustion group expressed lower level of GFAP and less aggregation of β-amyloid in the hippocampus than the sham control. Conclusion. Our findings suggest that moxibustion may enhance learning capability of ApoE−/− mice. The mechanism may be via inhibiting oxidized proteins (GFAP and β-amyloid) in astrocytes

    FMRI connectivity analysis of acupuncture effects on an amygdala-associated brain network

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    <p>Abstract</p> <p>Background</p> <p>Recently, increasing evidence has indicated that the primary acupuncture effects are mediated by the central nervous system. However, specific brain networks underpinning these effects remain unclear.</p> <p>Results</p> <p>In the present study using fMRI, we employed a within-condition interregional covariance analysis method to investigate functional connectivity of brain networks involved in acupuncture. The fMRI experiment was performed before, during and after acupuncture manipulations on healthy volunteers at an acupuncture point, which was previously implicated in a neural pathway for pain modulation. We first identified significant fMRI signal changes during acupuncture stimulation in the left amygdala, which was subsequently selected as a functional reference for connectivity analyses. Our results have demonstrated that there is a brain network associated with the amygdala during a resting condition. This network encompasses the brain structures that are implicated in both pain sensation and pain modulation. We also found that such a pain-related network could be modulated by both verum acupuncture and sham acupuncture. Furthermore, compared with a sham acupuncture, the verum acupuncture induced a higher level of correlations among the amygdala-associated network.</p> <p>Conclusion</p> <p>Our findings indicate that acupuncture may change this amygdala-specific brain network into a functional state that underlies pain perception and pain modulation.</p

    A desinstitucionalização e as alternativas habitacionais ao dispor de indivíduos com perturbações mentais: Um novo modelo habitacional – A habitação apoiada

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    Desde o início do processo de desinstitucionalização desinstitucionalização que este se tem vindo a deparar com dificuldades. Passando pelos poucos recursos ao dispor dos serviços de saúde mental, à tendência para trabalhar com os elementos que apresentam maiores probabilidades de sucesso, à não articulação entre os serviços hospitalares e os centros comunitários de saúde mental, até à falta de investimentos em alternativas habitacionais de carácter permanente. Estas têm sido algumas das situações a que os consumidores de serviços de saúde mental se têm sujeitado. Actualmente, assistimos à emergência de um paradigma que assenta na crença de que se deverá prestar apoio a estes consumidores numa casa tipicamente normal, com uma vivência na comunidade, em que o apoio é disponibilizado consoante as necessidades de cada indivíduo sem que exista uma limitação temporal à sua prestação. Torna-se assim necessário criar novos papéis para os técnicos, no sentido de que estes ajudem os consumidores a escolher, a obter, e a manter uma habitação. É pois urgente o desenvolvimento de um conjunto diversificado de alternativas habitacionais que se baseiem nos recursos e capacidades das comunidades locais, no sentido de garantir que o processo de desinstitucionalização se conclua com sucesso. Palavras-chave: desinstitucionalização, habitação apoiada, satisfação dos consumidores, doença mental.ABSTRACT: Since its beginning the deinstitutiondeinstitutionalization process has faced some difficulties, such as the mental health services lack of resources, the trend to work with the individual who presents higher probability of success, the lack of articulation between hospital services and community mental health centers, and the lack of investments on accommodations for long periods of time. These are some of the situations that consumers of mental health services have endured. Nowadays we witness the emerging of a paradigm which lies on the idea that these consumers need to be supported at a ordinary house, living in community, where the support is provided according to each person’s needs, and without a time limit. This paradigm also creates a need for the professionals to find new roles so that they will be able to help the consumers to choose, get, and keep a home. To ensure the success of deinstitutionalization it is vital that the establishment of different alternatives of accommodation be based on communities’ resources and capabilities.info:eu-repo/semantics/publishedVersio

    Revisiting the disciplinary role of failed takeover attempts

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    I find that the likelihood of CEO turnover in target firms following failed takeover attempts is negatively correlated with the target firms\u27 performance both prior to and during the failed takeover attempt. I also find that target firms that initiate corporate restructurings during the failed attempt have more positive stock returns in this period and are less likely to experience subsequent CEO turnover. When restructurings do not occur, an active outside blockholder is more likely to emerge and to facilitate the ouster of the target CEO. Together these findings indicate that failed takeover attempts act as wake-up calls either to target managers to make value-increasing improvements or to alternative control mechanisms to replace the incumbent managers

    Short Squeezes

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    Constant-Modulus-Waveform Design for Multiple-Target Detection in Colocated MIMO Radar

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    For improving the performance of multiple-target detection in a colocated multiple-input multiple-output (MIMO) radar system, a constant-modulus-waveform design method is presented in this paper. The proposed method consists of two steps: simultaneous multiple-transmit-beam design and constant-modulus-waveform design. In the first step, each transmit beam is controlled by an ideal orthogonal waveform and a weight vector. We optimized the weight vectors to maximize the detection probabilities of all targets or minimize the transmit power for the purpose of low intercept probability in the case of predefined worst detection probabilities. Various targets’ radar cross-section (RCS) fluctuation models were also considered in two optimization problems. Then, the optimal weight vectors multiplied by ideal orthogonal waveforms were a set of transmitted waveforms. However, those transmitted waveforms were not constant-modulus waveforms. In the second step, the transmitted waveforms obtained in the first step were mapped to constant-modulus waveforms by cyclic algorithm. Numerical examples are provided to show that the proposed constant-waveform design method could effectively achieve the desired transmit-beam pattern, and that the transmit-beam pattern could be adaptively adjusted according to prior information
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