560 research outputs found
Core-competitive Auctions
One of the major drawbacks of the celebrated VCG auction is its low (or zero)
revenue even when the agents have high value for the goods and a {\em
competitive} outcome could have generated a significant revenue. A competitive
outcome is one for which it is impossible for the seller and a subset of buyers
to `block' the auction by defecting and negotiating an outcome with higher
payoffs for themselves. This corresponds to the well-known concept of {\em
core} in cooperative game theory.
In particular, VCG revenue is known to be not competitive when the goods
being sold have complementarities. A bottleneck here is an impossibility result
showing that there is no auction that simultaneously achieves competitive
prices (a core outcome) and incentive-compatibility.
In this paper we try to overcome the above impossibility result by asking the
following natural question: is it possible to design an incentive-compatible
auction whose revenue is comparable (even if less) to a competitive outcome?
Towards this, we define a notion of {\em core-competitive} auctions. We say
that an incentive-compatible auction is -core-competitive if its
revenue is at least fraction of the minimum revenue of a
core-outcome. We study the Text-and-Image setting. In this setting, there is an
ad slot which can be filled with either a single image ad or text ads. We
design an core-competitive randomized auction and an
competitive deterministic auction for the Text-and-Image
setting. We also show that both factors are tight
Post-Mortem Immunohistochemical Evidence of β2-Adrenergic Receptor Expression in the Adrenal Gland
The evidence from post-mortem biochemical studies conducted on cortisol and catecholamines suggest that analysis of the adrenal gland could provide useful information about its role in human pathophysiology and the stress response. Authors designed an immunohistochemical study on the expression of the adrenal β2-adrenergic receptor (β2-AR), a receptor with high-affinity for catecholamines, with the aim to show which zones it is expressed in and how its expression differs in relation to the cause of death. The immunohistochemical study was performed on adrenal glands obtained from 48 forensic autopsies of subjects that died as a result of different pathogenic mechanisms using a mouse monoclonal β2-AR antibody. The results show that immunoreactivity for β2-AR was observed in all adrenal zones. Furthermore, immunoreactivity for β2-AR has shown variation in the localization and intensity of different patterns in relation to the original cause of death. To the best of our knowledge, this is the first study that demonstrates β2-AR expression in the human cortex and provides suggestions on the possible involvement of β2-AR in human cortex hormonal stimulation. In conclusion, the authors provide a possible explanation for the observed differences in expression in relation to the cause of death
The Cupuacu (Theobroma Grandiflorum) fruit. High performance liquid chromatographic determination of antioxidant phenolic substances in cupuacu seed powder
A method for the qualitative analysis of antioxidant phenolic substances in cupuacu seed
powder by high performance liquid chromatography is described.
We have used n-exhane to degrease the cupuacu seed powder and a methanol-water
(80:20) solution for the extraction of the analytes. HPLC separation was carried out by using a
binary gradient elution utilizing methanol-acetonitrile 1:1 (v/v) and 0.5% (w/v)
phosphoric acid. Spectral scans were continuously collected in the range 210-370 nm
and the spectrophotometric chromatogram was plotted at 280 nm. Spectrofluorimetric
detection was carried out with excitation at 280 nm and emission at 330 nm. Epicatechin
and quercetin were identified by comparing the chromatographic behaviour and the UV
spectrum of the extracted components with those of pure standards, while the
spectrofluorimetric detection, by stopped flow technique, has allowed the identification of
catechin and has confirmed the spectrophotometric identification of epicatechin
ClaimChain: Improving the Security and Privacy of In-band Key Distribution for Messaging
The social demand for email end-to-end encryption is barely supported by
mainstream service providers. Autocrypt is a new community-driven open
specification for e-mail encryption that attempts to respond to this demand. In
Autocrypt the encryption keys are attached directly to messages, and thus the
encryption can be implemented by email clients without any collaboration of the
providers. The decentralized nature of this in-band key distribution, however,
makes it prone to man-in-the-middle attacks and can leak the social graph of
users. To address this problem we introduce ClaimChain, a cryptographic
construction for privacy-preserving authentication of public keys. Users store
claims about their identities and keys, as well as their beliefs about others,
in ClaimChains. These chains form authenticated decentralized repositories that
enable users to prove the authenticity of both their keys and the keys of their
contacts. ClaimChains are encrypted, and therefore protect the stored
information, such as keys and contact identities, from prying eyes. At the same
time, ClaimChain implements mechanisms to provide strong non-equivocation
properties, discouraging malicious actors from distributing conflicting or
inauthentic claims. We implemented ClaimChain and we show that it offers
reasonable performance, low overhead, and authenticity guarantees.Comment: Appears in 2018 Workshop on Privacy in the Electronic Society
(WPES'18
Salicylic Acid Peel Incorporating Triethyl Citrate and Ethyl Linoleate in the Treatment of Moderate Acne: A New Therapeutic Approach.
BACKGROUND:
Acne affects many adolescents. Conventional therapy often results in side effects and poor adherence, and the treatment does not consider the psychological effect of acne on patients, which is comparable with that of disabling diseases.
OBJECTIVES:
To evaluate the efficacy and tolerability of a peel (30% salicylic acid, triethyl citrate and ethyl linoleate) combined with a home therapy with three topical agents (triethyl citrate, ethyl linoleate and salicylic acid 0.5% cream, lotion) in moderate acne of the face.
DESIGN:
Prospective, observational, multicenter, open-label, postmarketing, phase IV study.
METHODS:
Patients were assessed by comparing Global Acne Grading System (GAGS) score and total lesion count from 15 days before the first peel (T-15 ), after four salicylic peels (every 10 ± 2 days (T0 , T10 , T20 , T30 ), and 20 days after of the end of the study (T50 ). This treatment was associated to a home therapy.
RESULTS:
Fifty-three patients completed the study. The average GAGS score fell 49% between T-15 and T50 (p < .001). No patient withdrew for adverse events.
CONCLUSIONS:
This therapy was effective and well-tolerated in all cases. Chemo-exfoliation sessions ensured the continuous monitoring of clinical results and improved patient quality of life
Mediterranean Diet as a Shield against Male Infertility and Cancer Risk Induced by Environmental Pollutants: A Focus on Flavonoids
The role of environmental factors in influencing health status is well documented. Heavy metals, polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls, dioxins, pesticides, ultrafine particles, produced by human activities put a strain on the body’s entire defense system. Therefore, together with public health measures, evidence-based individual resilience measures are necessary to mitigate cancer risk under environmental stress and to prevent reproductive dysfunction and non-communicable diseases; this is especially relevant for workers occupationally exposed to pollutants and/or populations residing in highly polluted areas. The Mediterranean diet is characterized by a high intake of fruits and vegetables rich in flavonoids, that can promote the elimination of pollutants in tissues and fluids and/or mitigate their effects through different mechanisms. In this review, we collected evidence from pre-clinical and clinical studies showing that the impairment of male fertility and gonadal development, as well as cancers of reproductive system, due to the exposure of organic and inorganic pollutants, may be counteracted by flavonoids
Expression of bilitranslocase in the vascular endothelium and its function as a flavonoid transporter
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Positive surgical margin during radical prostatectomy: overview of sampling methods for frozen sections and techniques for the secondary resection of the neurovascular bundles
Objective: The aim of the paper is to provide an overview of intraoperative sampling methods for frozen section (FS) analysis and of surgical techniques for a secondary neurovascular bundle (NVB) resection, as the method of surgical margin (SM) sampling and the management of a positive SM (PSM) at the nerve-sparing (NS) area are under evaluated issues. FS analysis during radical prostatectomy (RP) can help to tailor the plane of dissection based on cancer extension and thus extend the indications for NS surgery. Evidence Acquisition: We performed a PubMed/Medical Literature Analysis and Retrieval System Online (MEDLINE), Web of Science, Cochrane Library, and Elton B. Stephens Co. (EBSCO)host search to include articles published in the last decade, evaluating FS analysis in the NS area and surgical attempts to convert a PSM to a negative status. Evidence Synthesis: Overall, 19 papers met our inclusion criteria. The ways to collect samples for FS analysis included: systematic (analysing the whole posterolateral aspect of the prostate specimen, i.e., neurovascular structure-adjacent frozen-section examination [NeuroSAFE]); magnetic resonance imaging (MRI)-guided (biopsies from MRI-suspicious areas, retrieved by the surgeon in a cognitive way); and random biopsies from the soft periprostatic tissues. Techniques to address a PSM in the NS area included: full resection of the spared NVB, from its caudal to cranial aspect, often including the rectolateral part of the Denonvilliers’ fascia; partial resection of the NVB, in cases where sampling attempts to localise a PSM; incremental approach, meaning a partial or full resection that extends until no prostate tissue is found in the soft periprostatic environment. Conclusions: There is no homogeneity in prostate sampling for FS analysis, although most recent evidence is moving toward a systematic sampling of the entire NS area. The management of a PSM is variable and can be affected by the sampling strategy (difficult localisation of the persisting tumour at the NVB). The difficult identification of the exact soft tissue location contiguous to a PSM could be considered as the critical point of FS analysis and of spared-NVB management
Pharmacological treatment options for low Bone Mineral Density and secondary osteoporosis in Anorexia Nervosa: A systematic review of the literature
OBJECTIVE:
Although there are several evidence-based treatments available to increase Bone Mineral Density (BMD) and reduce fracture risk in aging men and women, there are still uncertainties regarding which treatments are efficacious in reducing lifetime fracture risk in women with Anorexia Nervosa (AN).
METHODS:
Medline, PsychInfo, Embase and the Cochrane Database were searched for English Language Studies. Inclusion criteria were studies of females of any age with AN who received pharmacological treatment with the primary aim to increase BMD or reduce fracture risk. Data were extracted from each study regarding pharmacological treatment and dosage used, BMD and bone formation marker outcomes; and participant characteristics including age, Body Mass Index (BMI), duration of AN, and duration of amenorrhea.
RESULTS:
675 studies were reviewed, of which 19 fit the inclusion criteria and were included in the final review, investigating a total of 1119 participants; 10 of the 19 included studies were double-blind RCTs. The remaining studies consisted of prospective observational studies, a retrospective cohort study, a case-control study and five non-randomised control trials. Bisphosphonates were effective in increasing BMD in adult women with AN, while estrogen administered transdermally resulted in significant increases in BMD in mature adolescents with AN. Administration of oral contraceptives (OC) did not significantly increase BMD in randomised or controlled trials, however, lifetime OC use was associated with higher spinal BMD.
CONCLUSION:
Future research should clarify the safety of long-term bisphosphonate use in adult women with AN, and verify that transdermal estrogen replacement increases BMD in women with AN
Ruolo della timectomia nel trattamento della miastenia gravis: considerazioni e casistica personale
L’effetto terapeutico della timectomia sul decorso clinico della
miastemia gravis è ancora quanto mai controverso. Infatti, mentre la
chirurgia è ormai universalmente accettata per i timomi, il suo ruolo
è ancora discutibile in pazienti con miastenia gravis.
La via chirurgica di elezione per la timectomia totale è rappre -
sentata dalla sternotomia mediana. Altre metodologie chirurgiche
includono l’accesso cervicale e la sternotomia parziale. Queste tecni -
che, seppure con alterne fortune, hanno mostrato risultati eccellenti
nella exeresi del timo. Più recentemente la timectomia toracoscopica
video-assistita è stata proposta come una tecnica meno invasiva e
parimenti efficace per l’asportazione di quest’organo ed il trattamento
della miastenia gravis.
Scopo del presente lavoro è quello di riferire l’esperienza degli
Autori in tema di timectomia, analizzando i dati riportati dalla lette -
ratura internazionale sulla mortalità operatoria, le eventuali compli -
canze e i risultati estetici delle diverse tipologie di accesso chirurgico
- …