295 research outputs found

    Judgment aggregation in search for the truth

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    We analyze the problem of aggregating judgments over multiple issues from the perspective of whether aggregate judgments manage to efficiently use all voters' private information. While new in judgment aggregation theory, this perspective is familiar in a different body of literature about voting between two alternatives where voters' disagreements stem from conflicts of information rather than of interest. Combining the two bodies of literature, we consider a simple judgment aggregation problem and model the private information underlying voters' judgments. Assuming that voters share a preference for true collective judgments, we analyze the resulting strategic incentives and determine which voting rules efficiently use all private information. We find that in certain, but not all cases a quota rule should be used, which decides on each issue according to whether the proportion of ‘yes’ votes exceeds a particular quota

    Long-term Experience with the Björk-Shiley Monostrut Tilting Disc Valve

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    The Björk-Shiley Monostrut valve is tilting disc mechanical valve prosthesis. This study was designed to present the long-term outcome of our experience. One hundred and thirty-seven Björk-Shiley Monostrut valves were implanted in 101 consecutive patients from November 1983 to February 1990. There were 60 male and 41 female with mean age of 34.5 yr at the time of operation. Fifty-nine patients underwent single valve replacement, 38 had double valve, and 4 had triple valve replacement. There were six in-hospital deaths (5.9%): three from cardiopulmonary bypass weaning failure and one each from septic shock, sudden cardiac arrest, and uncontrollable bleeding. Mean duration of follow-up was 181.2±76.2 months. Overall survival was 86.2% at 15 yr and 83.1% at 20 yr. Patients with mitral valve replacement had 93.5% and 90.2% cumulative survival at 10 and 15 yr, respectively, while patients with aortic valve replacement had 91.1% and 86.5% cumulative survival at 10 and 15 yr. Two groups had no significant difference in survival. Double valve replacement patients had 92.2% and 84.0% survival at 10 and 15 yr, respectively. There were no significant differences in survival between the single and double valve replacement groups. Freedom from thromboembolism was noted in: 97.8%, 97.8%, 96.4% and 87.8% at 5, 10, 15 and 20 yr, respectively. Absence of endocarditis was noted in 98.6% and 94.8% at 15 and 20 yr. Absence of reoperation was 92.5% at 20 yr. In conclusion, the Björk-Shiley Monostrut valve is reliable, with a similar incidence of valve-related morbidity as in other mechanical valves

    Properties of charmed and bottom hadrons in nuclear matter: A plausible study

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    Changes in properties of heavy hadrons with a charm or a bottom quark are studied in nuclear matter. Effective masses (scalar potentials) for the hadrons are calculated using quark-meson coupling model. Our results also suggest that the heavy baryons containing a charm or a bottom quark will form charmed or bottom hypernuclei, which was first predicted in mid 70's. In addition a possibility of BB^--nuclear bound (atomic) states is briefly discussed.Comment: Latex, 11 pages, 3 figures, text was expanded substantially, version to appear in Phys. Lett.

    Λc+\Lambda^+_c- and Λb\Lambda_b-hypernuclei

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    Λc+\Lambda^+_c- and Λb\Lambda_b-hypernuclei are studied in the quark-meson coupling (QMC) model. Comparisons are made with the results for Λ\Lambda-hypernuclei studied in the same model previously. Although the scalar and vector potentials felt by the Λ\Lambda, Λc+\Lambda_c^+ and Λb\Lambda_b in the corresponding hypernuclei multiplet which has the same baryon numbers are quite similar, the wave functions obtained, e.g., for 1s1/21s_{1/2} state, are very different. The Λc+\Lambda^+_c baryon density distribution in Λc+209^{209}_{\Lambda^+_c}Pb is much more pushed away from the center than that for the Λ\Lambda in Λ209^{209}_\LambdaPb due to the Coulomb force. On the contrary, the Λb\Lambda_b baryon density distributions in Λb\Lambda_b-hypernuclei are much larger near the origin than those for the Λ\Lambda in the corresponding Λ\Lambda-hypernuclei due to its heavy mass. It is also found that level spacing for the Λb\Lambda_b single-particle energies is much smaller than that for the Λ\Lambda and Λc+\Lambda^+_c.Comment: Latex, 14 pages, 4 figures, text was extended, version to appear in Phys. Rev.

    Seronegative Herpes simplex Associated Esophagogastric Ulcer after Liver Transplantation

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    Herpes simplex infection is characterized by acute or subacute infection, often followed by a chronic carrier state. Consecutive recurrences may flare up if immunocompromise occurs. Herpes simplex associated esophagitis or duodenal ulcer have been reported in immunocompromised patients due to neoplasm, HIV/AIDS or therapeutically induced immune deficiency. Here we report the case of an HSV-DNA seronegative patient who developed grade III dysphagia 13 days after allogeneic liver transplantation. Endoscopy revealed an esophageal-gastric ulcer, and biopsy histopathology showed a distinct fibroplastic and capillary ulcer pattern highly suspicious for viral infection. Immunohistochemistry staining revealed a distinct nuclear positive anti-HSV reaction. Antiviral therapy with acyclovir and high-dose PPI led to a complete revision of clinical symptoms within 48 h. Repeat control endoscopy after 7 days showed complete healing of the former ulcer site at the gastroesophageal junction. Although the incidence of post-transplantation Herpes simplex induced gastroesophageal disease is low, the viral HSV ulcer may be included into a differential diagnosis if dysphagia occurs after transplantation even if HSV-DNA PCR is negative

    High-throughput screening for industrial enzyme production hosts by droplet microfluidics

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    A high-throughput method for single cell screening by microfluidic droplet sorting is applied to a whole-genome mutated yeast cell library yielding improved production hosts of secreted industrial enzymes. The sorting method is validated by enriching a yeast strain 14 times based on its a-amylase production, close to the theoretical maximum enrichment. Furthermore, a 105 member yeast cell library is screened yielding a clone with a more than 2-fold increase in a-amylase production. The increase in enzyme production results from an improvement of the cellular functions of the production host in contrast to previous droplet-based directed evolution that has focused on improving enzyme protein structure. In the workflow presented, enzyme producing single cells are encapsulated in 20 pL droplets with a fluorogenic reporter substrate. The coupling of a desired phenotype (secreted enzyme concentration) with the genotype (contained in the cell) inside a droplet enables selection of single cells with improved enzyme production capacity by droplet sorting. The platform has a throughput over 300 times higher than that of the current industry standard, an automated microtiter plate screening system. At the same time, reagent consumption for a screening experiment is decreased a million fold, greatly reducing the costs of evolutionary engineering of production strains

    Treponema denticola chymotrypsin-like protease as associated with HPV-negative oropharyngeal squamous cell carcinoma

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    BACKGROUND: An opportunistic oral pathogen, Treponema denticola (Td), has been linked to orodigestive carcinogenesis, but its role in oropharyngeal squamous cell carcinoma (OPSCC) has remained open. We evaluated the presence of Td chymotrypsin-like protease (Td-CTLP) in a series of 201 unselected consecutive OPSCC patients, and the relation of the Td-CTLP to human papillomavirus (HPV) status, to expression of toll-like receptors (TLR) 5, 7, and 9, and to clinical parameters and patient outcome. METHODS: Clinicopathological data came from hospital registries. The expression of cell surface-bound Td-CTLP was evaluated by immunohistochemistry. Immunoexpression of TLRs 5, 7, and 9, and HPV status we studied earlier in this patient series. RESULTS: We detected Td-CTLP in 81% of the OPSCC, and especially in HPV-negative tumours (48% of all OPSCCs). Among the HPV-positive tumours (52% of all OPSCCs), low Td-CTLP expression associated with low TLR 5 and high TLR 7 expression. Among those HPV-negative, higher TLR 5 and lower TLR 7 expression associated with high Td-CTLP expression. Strong Td-CTLP expression associated with poor disease-specific survival, but no similar association among HPV-positive and HPV-negative subgroups emerged. CONCLUSIONS: Td-CTLP was highly expressed in OPSCC and was associated with the HPV status of tumour tissue.Peer reviewe

    Genetic predictors of acute toxicities related to radiation therapy following lumpectomy for breast cancer: a case-series study

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    INTRODUCTION: The cytotoxic effects of radiation therapy are mediated primarily through increased formation of hydroxyl radicals and reactive oxygen species, which can damage cells, proteins and DNA; the glutathione S-transferases (GSTs) function to protect against oxidative stress. We hypothesized that polymorphisms encoding reduced or absent activity in the GSTs might result in greater risk for radiation-associated toxicity. METHODS: Women receiving therapy in radiation units in Germany following lumpectomy for breast cancer (1998–2001) provided a blood sample and completed an epidemiological questionnaire (n = 446). Genotypes were determined using Sequonom MALDI-TOF (GSTA1, GSTP1) and Masscode (GSTM1, GSTT1). Biologically effective radiotherapy dose (BED) was calculated, accounting for differences in fractionation and overall treatment time. Side effects considered were grade 2c and above, as classified using the modified Common Toxicity Criteria. Predictors of toxicity were modelled using Cox regression models in relation to BED, with adjustment for treating clinic, photon field, beam energy and boost method, and potential confounding variables. RESULTS: Low activity GSTP1 genotypes were associated with a greater than twofold increase in risk for acute skin toxicities (adjusted hazard ratio 2.28, 95% confidence interval 1.04–4.99). No associations were noted for the other GST genotypes. CONCLUSION: These data indicate that GSTP1 plays an important role in protecting normal cells from damage associated with radiation therapy. Studies examining the effects of GSTP1 polymorphisms on toxicity, recurrence and survival will further inform individualized therapeutics based on genotypes

    Mid- and long-term clinical results of surgical therapy in unicameral bone cysts

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    <p>Abstract</p> <p>Background</p> <p>Unicameral (or simple) bone cysts (UBC) are benign tumours most often located in long bones of children and adolescents. Pathological fractures are common, and due to high recurrence rates, these lesions remain a challenge to treat. Numerous surgical procedures have been proposed, but there is no general consensus of the ideal treatment. The aim of this investigation therefore was to study the long-term outcome after surgical treatment in UBC.</p> <p>Methods</p> <p>A retrospective analysis of 46 patients surgically treated for UBC was performed for short and mid-term outcome. Clinical and radiological outcome parameters were studied according to a modified Neer classification system. Long-term clinical information was retrieved via a questionnaire at a minimum follow-up of 10 years after surgery.</p> <p>Results</p> <p>Forty-six patients (17 female, 29 male) with a mean age of 10.0 ± 4.8 years and with histopathologically confirmed diagnosis of UBC were included. Pathological fractures were observed in 21 cases (46%). All patients underwent surgery for UBC (35 patients underwent curettage and bone grafting as a primary therapy, 4 curettage alone, 3 received corticoid instillation and 4 decompression by cannulated screws). Overall recurrence rate after the first surgical treatment was 39% (18/46), second (17.4% of all patients) and third recurrence (4.3%) were frequently observed and were addressed by revision surgery. Recurrence was significantly higher in young and in male patients as well as in active cysts. After a mean of 52 months, 40 out of 46 cysts were considered healed. Prognosis was significantly better when recurrence was observed later than 30 months after therapy. After a mean follow-up of 15.5 ± 6.2 years, 40 patients acknowledged clinically excellent results, while five reported mild and casual pain. Only one patient reported a mild limitation of range of motion.</p> <p>Conclusions</p> <p>Our results suggest satisfactory overall long-term outcome for the surgical treatment of UBC, although short-and mid-term observation show a considerable rate of recurrence independent of the surgical technique.</p
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