273 research outputs found

    Daily Mutual Fund Flows and Redemption Policies

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    We examine how redemption policies affect daily fund flows in open-end mutual funds. Since short-term trading of fund shares, as manifested in daily fund flows, can have an adverse impact on returns to the fund’s shareholders, mutual funds might find it desirable to discourage short-term trading through the use of redemption fees. However, if daily fund flows are due to fund shareholders’ legitimate liquidity demands, the redemption fee would have little effect on daily fund flows and possibly adversely affect fund shareholders by imposing a liquidity cost on them. We find that the likelihood of a fund charging a redemption fee is largely a function of its overall fee structure. We also use a sample of funds that imposed redemption fees to examine whether the distribution of daily fund flows changes after the initiation of the redemption fee. We find that the redemption fee is an effective tool in controlling the volatility of fund flows

    The Effectiveness of a Far Lateral L5-S1 Microdiscectomy in Pain Reduction

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    Diagnosis of far lateral disc herniations has become more common in recent years. This study describes the surgical procedure used for L5-S1 far lateral disc herniations, shows the benefits derived from a far lateral approach and retrospectively evaluates the outcome of the surgery. Eight patients were included in the study, five females and three males. The mean age was 62 years (range, 45-77 years). VAS pain scale, OSW index and SF-36 forms were used to evaluate the surgical outcome. Both the VAS pain scale and OSW index were improved postoperatively. The SF-36 scores were significantly lower (p\u3c0.05) for the far lateral patients compared to both the low back pain population and the U.S. aged 55-64 year population

    Public Perceptions of Values Associated with Wildfire Protection at the Wildland-Urban Interface: A Synthesis of National Findings

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    The wildland-urban interface (WUI) continues to transform rural landscapes as previously undeveloped areas are populated with residential and commercial structures which, in turn, impact ecosystems and create landscapes of risk. Within this context, the science of wildfire risk mitigation has experienced renewed and enhanced support among scientists and managers. However, risk mitigation measures have not found purchase in either the public’s acceptance or involvement in this new role of and for fire. This may partially result from little regard for the effects of wildfire prevention efforts on values other than protecting homes and other structures. We report findings from qualitative interviews conducted across the United States to identify and define various values at risk from wildfire. Values influencing risk mitigation emerged from the biophysical, sociodemographic, and sociocultural contexts of wildfire. Findings demonstrate how wildfire is intertwined with diverse sets of risks experienced in daily life. We provide a discussion of how this research impacts the transformation of landscapes and risk management strategies. Identifying and better understanding the effects of values associated with wildfire—and landscape change in the WUI—will allow natural resource managers and decision makers to develop more effective fuel treatment programs and land use policies

    Substrate-Dependent Effects of Human ABCB1

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    New ice-binding face for type I antifreeze protein

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    AbstractType I antifreeze protein (AFP) from winter flounder is an alanine-rich, 37 amino acid, single α-helix that contains three 11 amino acid repeats (Thr-X2-Asx-X7), where X is generally Ala. The regularly spaced Thr, Asx and Leu residues lie on one face of the helix and have traditionally been thought to form hydrogen bonds and van der Waals interactions with the ice surface. Recently, substitution experiments have called into question the importance of Leu and Asn for ice-binding. Sequence alignments of five type I AFP isoforms show that Leu and Asn are not well conserved, whereas Ala residues adjacent to the Thr, at right angles to the Leu/Asn-rich face, are completely conserved. To investigate the role of these Ala residues, a series of Ala to Leu steric mutations was made at various points around the helix. All the substituted peptides were fully α-helical and remained as monomers in solution. Wild-type activity was retained in A19L and A20L. A17L, where the substitution lies adjacent to the Thr-rich face, had no detectable antifreeze activity. The nearby A21L substitution had 10% wild-type activity and demonstrated weak interactions with the ice surface. We propose a new ice-binding face for type I AFP that encompasses the conserved Ala-rich surface and adjacent Thr

    Postoperative Infection Rates with Instrumented Lumbar Fusion: A Retrospective Review of 129 Consecutive Cases

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    Introduction: The use of internal fixation devices in spinal surgery is common to achieve reduction, maintain alignment, and stabilize the spine while fusion occurs. Infection rates of less than 2% (0-2%) were reported in the late 1960\u27s without the use of instrumentation. Reported rates of infection following instrumented fusion are generally around 6% (range 0-11% ). The purpose of this study was to retrospectively review the incidence of postoperative infection following instrumented spinal fusion to determine if infection rates related to patient type and surgical procedure. Methods: A retrospective review was conducted of 129 consecutive cases of instrumented lumbar spinal fusion. Three patients were eliminated from the study: two due to preoperative spinal infections, and a third patient expired from unrelated disease. All instrumented fusion cases were eligible for this study regardless of level or technique used. Results: Of the 126 instrumented cases there were no superficial infections, and one (0.8%) deep infection. The infection was completely resolved and did not prevent solid fusion with good alignment. The patient was a smoker and received autograft bone. Discussion: The results of this review revealed substantially lower rates of postoperative infection following instrumented fusion than has been previously reported in the literature. No superficial and one (0.8%) deep infection was identified. Due to the low infection rates, no statistically significant conclusions could be made

    The Chattanooga Procedure: A New Technique Used for Anterior Multi-level Cervical Fusions

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    STUDY DESIGN: A preliminary assessment of anterior cervical fusion performed with interbody cage and DOC plate. OBJECTIVES: To describe and evaluate the efficacy and safety of the Chattanooga Procedure , a modified technique in achieving anterior cervical fusion. SUMMARY OF BACKGROUND DATA: Anterior cervical fusion with interbody bone graft and anterior plating is connnonly performed. Unfortunately, the plate has been reported to shield the graft from loading thus reducing fusion rates. The use of interbody fusion cages has been effective in the lumbar spine and has gained acceptance in the cervical spine. METHODS:. Twenty-five patients received The Chattanooga Procedure between 7/24/98 and 4/8/99. All patients had anterior discectomies and carpectomies, placement of a Harms cage packed with carpectomy bone, and application ofDePuy-Acromed DOC. Fusion was defined by radiographic evidence of trabecular bone bridging across the Harms cage. CT scans were performed on twelve randomly chosen patients to verify fusion. No external bracing was used except a soft collar as needed. Pre- and post-operative pain and functional capacity data were collected and statistically analyzed using paired t-tests. RESULTS: There were no cases of pseudoarthrosis, major neurological, vascular, or wound complications. Only one case of unresolved dysphasia was noted. The average operative time (11 0 minutes) was comparable to standard instrumented multi-level anterior cervical fusion surgeries. The average estimated blood loss was 113 ml (range, 50-750 ml). Both visual analog pain scale and Oswestry functional capacity data were significantly improved post-operatively (p\u3c 0.01). DISCUSSION: Advantages of the Chattanooga Procedure include immediate stability, support, elimination of donor site pain to iliac crest bone autograft, and a decrease in pseudoarthrosis by dividing the fusion surfaces by half. Concerns regarding this technique include an increased risk for dysphasia due to the DOC\u27s high profile. Pseudoarthrosis or instrumentation migration could also become problematic since the removal of the Harms cage could be difficult if necessary

    Privacy Concerns in Chatbot Interactions: When to Trust and When to Worry

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    Through advances in their conversational abilities, chatbots have started to request and process an increasing variety of sensitive personal information. The accurate disclosure of sensitive information is essential where it is used to provide advice and support to users in the healthcare and finance sectors. In this study, we explore users' concerns regarding factors associated with the use of sensitive data by chatbot providers. We surveyed a representative sample of 491 British citizens. Our results show that the user concerns focus on deleting personal information and concerns about their data's inappropriate use. We also identified that individuals were concerned about losing control over their data after a conversation with conversational agents. We found no effect from a user's gender or education but did find an effect from the user's age, with those over 45 being more concerned than those under 45. We also considered the factors that engender trust in a chatbot. Our respondents' primary focus was on the chatbot's technical elements, with factors such as the response quality being identified as the most critical factor. We again found no effect from the user's gender or education level; however, when we considered some social factors (e.g. avatars or perceived `friendliness'), we found those under 45 years old rated these as more important than those over 45. The paper concludes with a discussion of these results within the context of designing inclusive, digital systems that support a wide range of users

    An Investigation into the Sensitivity of Personal Information and Implications for Disclosure: A UK Perspective

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    The perceived sensitivity of information is a crucial factor in both security and privacy concerns and the behaviours of individuals. Furthermore, such perceptions motivate how people disclose and share information with others. We study this topic by using an online questionnaire where a representative sample of 491 British citizens rated the sensitivity of different data items in a variety of scenarios. The sensitivity evaluations revealed in this study are compared to prior results from the US, Brazil and Germany, allowing us to examine the impact of culture. In addition to discovering similarities across cultures, we also identify new factors overlooked in the current research, including concerns about reactions from others, personal safety or mental health and finally, consequences of disclosure on others. We also highlight a difference between the regulatory perspective and the citizen perspective on information sensitivity. We then operationalised this understanding within several example use-cases exploring disclosures in the healthcare and finance industry, two areas where security is paramount. We explored the disclosures being made through two different interaction means: directly to a human or chatbot mediated (given that an increasing amount of personal data is shared with these agents in industry). We also explored the effect of anonymity in these contexts. Participants showed a significant reluctance to disclose information they considered `irrelevant' or `out of context' information disregarding other factors such as interaction means or anonymity. We also observed that chatbots proved detrimental to eliciting sensitive disclosures in the healthcare domain; however, within the finance domain, there was less effect. This article's findings provide new insights for those developing online systems intended to elicit sensitive personal information from users

    Investigation of the High-Temperature Redox Chemistry of Sr\u3csub\u3e2\u3c/sub\u3eFe\u3csub\u3e1.5\u3c/sub\u3eMo\u3csub\u3e0.5\u3c/sub\u3eO\u3csub\u3e6-δ\u3c/sub\u3e\u3ci\u3e via In Situ\u3c/i\u3e Neutron Diffraction

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    Crystallographic structural changes were investigated for Sr2Fe1.5Mo0.5O6−δ, an electrode material for symmetric solid oxide fuel cells. The samples of this material were heated and cooled in wet hydrogen and wet oxygen atmospheres, to simulate the reducing and oxidizing conditions experienced under actual fuel cell operating conditions, and their structures and oxygen contents were determined using in situ powder neutron diffraction. The existence of a reversible tetragonal to cubic phase transition was established to occur between room temperature and 400 °C, both on heating and cooling in either oxygen or hydrogen. The oxygen content reaches a low value of 5.50(2) at 850 °C in wet hydrogen. Excellent correlations are observed between the oxygen content of the structure and the conductivities reported in the literature
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