354 research outputs found

    A counterexample to the CFT convexity conjecture

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    Motivated by the weak gravity conjecture, arXiv:2108.04594 conjectured that in any CFT, the minimal operator dimension at fixed charge is a convex function of the charge. In this letter we construct a counterexample to this convexity conjecture, which is a clockwork-like model with some modifications to make it a weakly-coupled CFT. We also discuss further possible applications of this model and some modified versions of the conjecture which are not ruled out by the counterexample

    A grounded theory approach to physical activity and advanced cancer:a qualitative study protocol

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    Background: Physical activity has demonstrated benefits in cancer-related fatigue and physical functioning in early-stage cancer patients; however, the role of physical activity at the end stage of cancer has not been established. To challenge positivist–empiricist assumptions, I am seeking to develop a new theoretical framework that is grounded in the advanced cancer patient’s experience of activity. Aim: To gain an in-depth understanding of the experience of activity and quality of life in advanced cancer patients. Objectives: (1) To explore the meaning of activity for advanced cancer patients in the context of their day-to-day life, (2) to elicit advanced cancer patients’ perceptions of activity with respect to their quality of life, and (3) to elicit advanced cancer patients’ views of barriers and facilitators to activity in the context of their day-to-day life. Study Design: A two-phase, crosssectional, qualitative study will be conducted through the postpositivist lens of subtle realism and informed by the principles of grounded theory methods. Study Methods: Advanced cancer patients will be recruited through the outpatient department of a tertiary cancer center. For Phase 1, participants will wear an activPAL™ activity monitor and fill out a daily record sheet for 7-day duration. For Phase 2, the activity monitor output and daily record sheets will be used as qualitative probes for face-to-face, semistructured interviews. Concurrent coding, constant comparative analysis, and theoretical sampling will continue with the aim of achieving as close as possible to theoretical saturation. Ethics and Discussion: Ethical and scientific approval will be obtained by all local institutional review boards prior to study commencement. The findings will generate new mid-level theory about the experience of activity and quality of life in advanced cancer patients and aid in the development of a new theoretical framework for designing interventions for this population

    Referral criteria for outpatient specialty palliative cancer care : an international consensus

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    Although outpatient specialty palliative-care clinics improve outcomes, there is no consensus on who should be referred or the optimal timing for referral. In response to this issue, we did a Delphi study to develop consensus on a list of criteria for referral of patients with advanced cancer at secondary or tertiary care hospitals to outpatient palliative care. 60 international experts (26 from North America, 19 from Asia and Australia, and 11 from Europe) on palliative cancer care rated 39 needs-based criteria and 22 time-based criteria in three iterative rounds. Nearly all experts responded in each round. Consensus was defined by an a-priori agreement of 70% or more. Panellists reached consensus on 11 major criteria for referral: severe physical symptoms, severe emotional symptoms, request for hastened death, spiritual or existential crisis, assistance with decision making or care planning, patient request for referral, delirium, spinal cord compression, brain or leptomeningeal metastases, within 3 months of advanced cancer diagnosis for patients with median survival of 1 year or less, and progressive disease despite second-line therapy. Consensus was also reached on 36 minor criteria for specialist palliative-care referral. These criteria, if validated, could provide guidance for identification of patients suitable for outpatient specialty palliative care.Peer reviewe

    The yeast p24 complex regulates gpi-anchored protein Transport and quality control by monitoring anchor remodeling

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    Glycosylphosphatidylinositol (GPI)-anchored proteins are secretory proteins that are attached to the cell surface of eukaryotic cells by a glycolipid moiety. Once GPI anchoring has occurred in the lumen of the endoplasmic reticulum (ER), the structure of the lipid part on the GPI anchor undergoes a remodeling process prior to ER exit. In this study, we provide evidence suggesting that the yeast p24 complex, through binding specifically to GPI- anchored proteins in an anchor-dependent manner, plays a dual role in their selective traffick - ing. First, the p24 complex promotes efficient ER exit of remodeled GPI-anchored proteins after concentration by connecting them with the COPII coat and thus facilitates their incorpo - ration into vesicles. Second, it retrieves escaped, unremodeled GPI-anchored proteins from the Golgi to the ER in COPI vesicles. Therefore the p24 complex, by sensing the status of the GPI anchor, regulates GPI-anchored protein intracellular transport and coordinates this with correct anchor remodelin

    Automatic referral to standardize palliative care access : an international Delphi survey

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    Palliative care referral is primarily based on clinician judgment, contributing to highly variable access. Standardized criteria to trigger automatic referral have been proposed, but it remains unclear how best to apply them in practice. We conducted a Delphi study of international experts to identify a consensus for the use of standardized criteria to trigger automatic referral. Sixty international experts stated their level of agreement for 14 statements regarding the use of clinician-based referral and automatic referral over two Delphi rounds. A consensus was defined as an agreement of ae70% a priori. The response rate was 59/60 (98%) for the first round and 56/60 (93%) for the second round. Twenty-six (43%), 19 (32%), and 11 (18%) respondents were from North America, Asia/Australia, and Europe, respectively. The panel reached consensus that outpatient palliative care referral should be based on both automatic referral and clinician-based referral (agreement = 86%). Only 18% felt that referral should be clinician-based alone, and only 7% agreed that referral should be based on automatic referral only. There was consensus that automatic referral criteria may increase the number of referrals (agreement = 98%), facilitate earlier palliative care access, and help administrators to set benchmarks for quality improvement (agreement = 86%). Our panelists favored the combination of automatic referral to augment clinician-based referral. This integrated referral framework may inform policy and program development.Peer reviewe

    A new type of lectin discovered in a fish, flathead (Platycephalus indicus), suggests an alternative functional role for mammalian plasma kallikrein*

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    A skin mucus lectin exhibiting a homodimeric structure and an S–S bond between subunits of ∼40 kDa was purified from flathead Platycephalus indicus (Scorpaeniformes). This lectin, named FHL (FlatHead Lectin), exhibited mannose-specific activity in a Ca2+-dependent manner. Although FHL showed no homology to any previously reported lectins, it did exhibit ∼20% identity to previously discovered plasma kallikreins and coagulation factor XIs of mammals and Xenopus laevis. These known proteins are serine proteases and play pivotal roles in the kinin-generating system or the blood coagulation pathway. However, alignment analysis revealed that while FHL lacked a serine protease domain, it was homologous to the heavy-chain domain of plasma kallikreins and coagulation factor XI therefore suggesting that FHL is not an enzyme but rather a novel animal lectin. On the basis of this finding, we investigated the lectin activity of human plasma kallikrein and revealed that it could indeed act as a lectin. Other genes homologous to FHL were also found in the genome databases of some fish species, but not in mammals. In contrast, plasma kallikreins and coagulation factor XI have yet to be identified in fish. The present findings suggest that these mammalian enzymes may have originally emerged as a lectin and may have evolved into molecules with protease activity after separation from common ancestors

    Cluster-Cluster Lensing and the Case of Abell 383

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    Extensive surveys of galaxy clusters motivate us to assess the likelihood of cluster-cluster lensing (CCL), namely, gravitational-lensing of a background cluster by a foreground cluster. We briefly describe the characteristics of CCLs in optical, X-ray and SZ measurements, and calculate their predicted numbers for Λ\LambdaCDM parameters and a viable range of cluster mass functions and their uncertainties. The predicted number of CCLs in the strong-lensing regime varies from several (<10<10) to as high as a few dozen, depending mainly on whether lensing triaxiality bias is accounted for, through the c-M relation. A much larger number is predicted when taking into account also CCL in the weak-lensing regime. In addition to few previously suggested CCLs, we report a detection of a possible CCL in A383, where background candidate high-zz structures are magnified, as seen in deep Subaru observations.Comment: 9 pages, 5 figures, submitted to MNRA

    Isoflavone glycosides: Synthesis and evaluation as α-glucosidase inhibitors

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    On the basis of the structure of 4′,7,8-trihydroxyisoflavone 7-O-α-D-arabinofuranoside (namely A-76202, 1), a Rhodococcus metabolite showing potent inhibitory activities against the α-glucosidases of rat liver microsome (IC 50 = 0.46 ng/mL), 26 analogs, each with minor variations at the sugar moiety and the isoflavone A and B rings, were readily synthesized. Notably, a new and efficient method was developed for the divergent synthesis of the B-ring congeners of the isoflavone glycosides by using Suzuki-Miyaura coupling as the final step. Modifications at the sugar moiety and the isoflavone A ring significantly diminish the activity, whereas variations at the B ring are largely tolerated for retaining the potent α-glucosidase inhibitory activity. © Wiley-VCH Verlag GmbH & Co. KGaA, 2008.postprin

    Glyconanoparticles for colorimetric bioassays

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    Carbohydrate molecules are involved in many of the cellular processes that are important for life. By combining the specific analyte targeting of carbohydrates with the multivalent structure and change of solution colour as a consequence of plasmonic interactions with the aggregation of metal nanoparticles, glyconanoparticles have been used extensively for the development of bioanalytical assays. The noble metals used to create the nanocore, the methodologies used to assemble the carbohydrates on the nanoparticle surface, the carbohydrate chosen for each specific target, the length of the tether that separates the carbohydrate from the nanocore and the density of carbohydrates on the surface all impact on the structural formation of metal based glyconanoparticles. This tutorial review highlights these key components, which directly impact on the selectivity and sensitivity of the developed bioassay, for the colorimetric detection of lectins, toxins and viruses
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