A Range-Normalization Model of Context-Dependent Choice: A New Model and Evidence

Most utility theories of choice assume that the introduction of an irrelevant option (called the decoy) to a choice set does not change the preference between existing options. On the contrary, a wealth of behavioral data demonstrates the dependence of preference on the decoy and on the context in which the options are presented. Nevertheless, neural mechanisms underlying context-dependent preference are poorly understood. In order to shed light on these mechanisms, we design and perform a novel experiment to measure within-subject decoy effects. We find within-subject decoy effects similar to what have been shown previously with between-subject designs. More importantly, we find that not only are the decoy effects correlated, pointing to similar underlying mechanisms, but also these effects increase with the distance of the decoy from the original options. To explain these observations, we construct a plausible neuronal model that can account for decoy effects based on the trial-by-trial adjustment of neural representations to the set of available options. This adjustment mechanism, which we call range normalization, occurs when the nervous system is required to represent different stimuli distinguishably, while being limited to using bounded neural activity. The proposed model captures our experimental observations and makes new predictions about the influence of the choice set size on the decoy effects, which are in contrast to previous models of context-dependent choice preference. Critically, unlike previous psychological models, the computational resource required by our range-normalization model does not increase exponentially as the set size increases. Our results show that context-dependent choice behavior, which is commonly perceived as an irrational response to the presence of irrelevant options, could be a natural consequence of the biophysical limits of neural representation in the brain

Identifying and Prioritizing of Readiness Factors for Implementing ERP Based on Agility (Extension of McKinsey 7S Model)

Studies conducted by many researchers indicate high failure rate of projects of implementing ERP systems. To penetrate in global competition market, it seems necessary to carry out studies to assess organizational readiness prior to system implementation to identify weaknesses and strengths points of the organization. Furthermore, organizations should be agile to be able to respond to market changes fast and effectively to survive in competitive environment. ERP and agility are two important tools for achieving competitive advantages. The main goal of the present study was to identify and prioritize organizational readiness factors for implementing ERP based on organizational agility. In this study, along with extension of McKinsey 7S model (strategy, structure, systems, skills, style, staff, shared values) to 9S (7S+ self-evaluation and supportive factors) model, agility criteria were weighted and rated using group AHP with fuzzy logic approach; so that accountability, speed and flexibility have obtained the maximum score. The nine organizational readiness factors were ranked using integrated FAHP and TOPSIS method based on five criteria of agility. The framework was proposed to a real case of Shiraz distribution cooperative firms. Results showed that among the nine organizational dimensions based on agility, the two added to McKinsey dimensions (self-evaluation and supportive factors) are ranked in the first and fourth places. The proposed framework help the firms “to implement ERP system with agility approach” concentrate on effective empowerments and develop strategies based on their own priority

Effect of Systemic Granisetron in the Clinical Course of Spinal Anesthesia with Hyperbaric Bupivacaine for Outpatient Cystoscopy

Background: The goals of this study are evaluation the effect of intravenous (IV) granisetron on the duration of sensory and motor block produced by intrathecal hyperbaric bupivacaine and also post-operative nausea and vomiting in patients undergoing outpatient cystoscopy.Methods: 62 patients, undergoing cystoscopy received either 3 mg IV granisetron or placebo 15 minutes before the spinal block. Sensory and motor block were assessed after the intrathecal injection of bupivacaine every 2 minutes until the maximum block was achieved and thereafter every 15 minutes until recovery from the sensory and motor block.Results: Demographic data were not statistically different in the study groups. Duration of sensory and motor block were also not statistically different between the study groups (P = 0.060 and P = 0.070 respectively). No patient in either group had vomiting. Seven patients in saline and zero patient in granisetron group had nausea that was statistically significant (P = 0.040). Time to discharge after surgery was 243 ± 21 and 239 ± 24 minutes in granisetron and control group respectively (P = 0.150).Conclusions: Systemic granisetron had no effect on the duration of sensory and motor block produced by spinal anesthesia with hyperbaric bupivacaine

Compare motor development of male and female children with consanguineous and in-law parents

زمینه و هدف: مطالعات نشان داده اند ازدواج فامیلی می تواند احتمال بروز مشکلات متعددی در رشد حرکتی را موجب گردد. هدف این تحقیق مقایسه رشد حرکتی کودکان دختر و پسر با والدین نسبی و سببی بوده است. روش بررسی: در این مطالعه مقطعی، رشد حرکتی 15 کودک 4 و 5 ساله و 15 کودک 8 و 9 ساله با والدین نسبی با 15 کودک 4 و 5 ساله و 15 کودک 8 و 9 ساله با والدین سببی که به صورت خوشه ای چند مرحله ای از چهار مدرسه ابتدایی دخترانه و پسرانه و پانزده مهد کودک شهرستان اراک انتخاب شده بودند مقایسه شد. برای سنجش رشد حرکتی از آزمون رشد حرکتی درشت اولریخ-2 استفاده گردید. یافته ها: بین مهارت های دستکاری، جابجایی و رشد حرکتی درشت کودکان دختر و پسر 4- 5 ساله و رشد حرکتی و مهارت های جابجایی و دستکاری کودکان پسر 9-8 ساله و مهارت های جابجایی کودکان دختر 9-8 ساله با والدین نسبی و سببی تفاوت معنی داری وجود نداشت (05/0P>)؛ ولی رشد حرکتی و مهارت های دستکاری کودکان دختر 9-8 ساله با والدین سببی بهتر از کودکان با والدین نسبی بود (05/0

The Relationship between Osteogenesis Imperfecta and Spinal Muscular Atrophy

ObjectiveA 4-month-old female with osteogenesis imperfecta (OI) type II was admitted in PICU of our center due to severe respiratory distress and fever with a diagnosis of severe pneumonia, and mechanical ventilation was initiated. Due to severe hypotonia, NCV and EMG were performed, and spinal muscular atrophy (SMA) type I was diagnosed.Keywords: Osteogenesis imperfecta; spinal muscular atrophy; hypotoni

Interaction of CNCl molecule and single-walled AlN nanotubes using DFT and TD-DFT calculations

AbstractDensity functional theory (DFT) calculations are used to study the influence of cyanogen chloride (CNCl) adsorption over the geometrical and electronic properties of single-walled (5, 0), (8, 0), and (10, 0) AlN nanotubes as an adsorbent for adsorbate. It has been found that, the CNCl can be adsorbed on (5, 0), (8, 0), and (10, 0) AlN nanotubes with the energy values of −0.645, −0.493, −0.470eV, respectively. In addition, the effect of nanotube diameter over the charge transfer between the molecule and nanotube has been studied. Based on the DOS plots, interaction of CNCl over AlN nanotubes has slightly changed the electronic properties of the nanotubes, being insensitive to the adsorption of the CNCl molecule

Optical properties of CdS/PVA nanocomposite films synthesized using the gamma-irradiation-induced method

Monodispersed spherical CdS nanoparticles embedded into polyvinyl alcohol (PVA) films are synthesized by using an in-situ gamma-irradiation-induced method. The formation mechanism of CdS nanoparticles capped by two united cells of PVA is purposed by means of surrounding the CdS nanoparticles with OH bonds of the PVA chain. CdS nanoparticles are found to possess an unusual orthorhombic structure in monoclinic crystalline PVA. The polymer matrix affords protection from agglomeration and controls the particle size. It is found that the distribution of the prepared nanoparticles increases and a narrower size distribution is observed when the gamma radiation is varied from 10 to 50 kGy. While the average size of the nanoparticles is found to be less affected by the variation of the gamma radiation doses. The size range of the synthesized nanoparticles is 14±1 nm. The optical absorption spectra of synthesized CdS nanoparticles in a polymer matrix reveal the blue shift in the band gap energy with respect to CdS bulk materials owing to quantum confinement effect. The photoluminescence study of nanocomposite films shows the green emission arising from the crystalline defects

Practical Traffic Analysis Attacks on Secure Messaging Applications

Instant Messaging (IM) applications like Telegram, Signal, and WhatsApp have become extremely popular in recent years. Unfortunately, such IM services have been targets of continuous governmental surveillance and censorship, as these services are home to public and private communication channels on socially and politically sensitive topics. To protect their clients, popular IM services deploy state-of-the-art encryption mechanisms. In this paper, we show that despite the use of advanced encryption, popular IM applications leak sensitive information about their clients to adversaries who merely monitor their encrypted IM traffic, with no need for leveraging any software vulnerabilities of IM applications. Specifically, we devise traffic analysis attacks that enable an adversary to identify administrators as well as members of target IM channels (e.g., forums) with high accuracies. We believe that our study demonstrates a significant, real-world threat to the users of such services given the increasing attempts by oppressive governments at cracking down controversial IM channels. We demonstrate the practicality of our traffic analysis attacks through extensive experiments on real-world IM communications. We show that standard countermeasure techniques such as adding cover traffic can degrade the effectiveness of the attacks we introduce in this paper. We hope that our study will encourage IM providers to integrate effective traffic obfuscation countermeasures into their software. In the meantime, we have designed and deployed an open-source, publicly available countermeasure system, called IMProxy, that can be used by IM clients with no need for any support from IM providers. We have demonstrated the effectiveness of IMProxy through experiments

Feature-Based Learning Improves Adaptability without Compromising Precision

Learning from reward feedback is essential for survival but can become extremely challenging with myriad choice options. Here, we propose that learning reward values of individual features can provide a heuristic for estimating reward values of choice options in dynamic, multi-dimensional environments. We hypothesize that this feature-based learning occurs not just because it can reduce dimensionality, but more importantly because it can increase adaptability without compromising precision of learning. We experimentally test this hypothesis and find that in dynamic environments, human subjects adopt feature-based learning even when this approach does not reduce dimensionality. Even in static, low-dimensional environments, subjects initially adopt feature-based learning and gradually switch to learning reward values of individual options, depending on how accurately objects’ values can be predicted by combining feature values. Our computational models reproduce these results and highlight the importance of neurons coding feature values for parallel learning of values for features and objects

A Study on Causes and Types of Abnormal Increase in Infants’ Head Circumference in Kashan/Iran

How to Cite This Article: Talebian A, Soltani B, Moravveji AR, Salamati L, Davami M. A Study on Causes and Types of Abnormal Increase in infants’ Head Circumference in Kashan/Iran. Iran J Child Neurol. 2013 Summer; 7(3): 28- 33. ObjectiveHead circumference is a valuable index of brain growth and its disturbances can indicate different disorders of nervous system. Abnormal increased head circumference (macrocephaly) is common and observed in about 2% of infants. In this study, the causes and clinical types of abnormal increase in infants’ head circumference were investigated in Kashan, Iran.Materials & MethodsThis cross-sectional study was performed on 90 infants less than 2 years of age with abnormal increase in head circumference in Kashan, during 2009- 2011. The data were collected by history taking, physical examination, growth chart, and imaging.Results65 (72%) cases out of 90 infants were male and 25 ( 28%) cases were female. Fifty-three (58.8%) cases had familial megalencephaly, 30 (33.4%) had hydrocephalus, and other causes were observed in 7 (7.8%) cases. Eighty-three percent of Infants with familial megalencephaly and 50% with hydrocephalus had normal fontanels. In 90.6% of cases withfamilial megalencephaly, family history for large head was positive. Motor development was normal in 100% of cases with familial megalencephaly and 76.7% of hydrocephalic infants.Conclusion Familial megalencephaly was the most common cause of macrocephaly in the studied infants, and most of them had normal physical examination and development, so, parental head circumferences should be considered in the interpretation of infant’s head circumference and in cases of abnormal physical examination or development, other diagnostic modalities, including brain imaging should be done. References1. Lunde A, Melve KK, Gjessing HK, Skjaerven R, Irgens LM. 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