Price competition with consumer confusion

Copyright © 2013, INFORMS. Article posted with permission.This paper proposes a model in which identical sellers of a homogeneous product compete in both prices and price frames (i.e., ways to present price information). Frame choices affect the comparability of price offers and may cause consumer confusion and lower price sensitivity. In equilibrium, firms randomize their frame choices to obfuscate price comparisons and sustain positive profits. The nature of the equilibrium depends on whether frame differentiation or frame complexity is more confusing. Moreover, an increase in the number of competitors induces firms to rely more on frame complexity, and this may boost industry profits and lower consumer surplus

Translation of MMTV Gag requires nuclear events involving splicing motifs in addition to the viral Rem protein and RmRE

<p>Abstract</p> <p>Background</p> <p>Retroviral Gag proteins are encoded in introns and, because of this localization, they are subject to the default pathways of pre-mRNA splicing. Retroviruses regulate splicing and translation through a variety of intertwined mechanisms, including 5'- post-transcriptional control elements, 3'- constitutive transport elements, and viral protein RNA interactions that couple unspliced and singly spliced mRNAs to transport machinery. Sequences within the <it>gag </it>gene termed inhibitory or instability sequences also appear to affect viral mRNA stability and translation, and the action of these sequences can be countered by silent mutation or the presence of RNA interaction proteins like HIV-1 Rev. Here, we explored the requirements for mouse mammary tumor virus (MMTV) Gag expression using a combination of <it>in vivo </it>and <it>in vitro </it>expression systems.</p> <p>Results</p> <p>We show that MMTV <it>gag </it>alleles are inhibited for translation despite possessing a functional open reading frame (ORF). The block to expression was post-transcriptional and targeted the mRNA but was not a function of mRNA transport or stability. Using bicistronic reporters, we show that inhibition of <it>gag </it>expression imparted a block to both cap-dependent and cap-independent translation onto the mRNA. Direct introduction of <it>in vitro </it>synthesized <it>gag </it>mRNA resulted in translation, implying a nuclear role in inhibition of expression. The inhibition of expression was overcome by intact proviral expression or by flanking <it>gag </it>with splice sites combined with a functional Rem-Rem response element (RmRE) interaction.</p> <p>Conclusions</p> <p>Expression of MMTV Gag requires nuclear interactions involving the viral Rem protein, its cognate binding target the RmRE, and surprisingly, both a splice donor and acceptor sequence to achieve appropriate signals for translation of the mRNA in the cytoplasm.</p

Subequivalence Relations and Positive-Definite Functions

We study a positive-definite function associated to a measure-preserving equivalence relation on a standard probability space and use it to measure quantitatively the proximity of subequivalence relations. This is combined with a recent co-inducing construction of Epstein to produce new kinds of mixing actions of an arbitrary infinite discrete group and it is also used to show that orbit equivalence of free, measure preserving, mixing actions of non-amenable groups is unclassifiable in a strong sense. Finally, in the case of property (T) groups we discuss connections with invariant percolation on Cayley graphs and the calculation of costs

Supervised Learning in Multilayer Spiking Neural Networks

The current article introduces a supervised learning algorithm for multilayer spiking neural networks. The algorithm presented here overcomes some limitations of existing learning algorithms as it can be applied to neurons firing multiple spikes and it can in principle be applied to any linearisable neuron model. The algorithm is applied successfully to various benchmarks, such as the XOR problem and the Iris data set, as well as complex classifications problems. The simulations also show the flexibility of this supervised learning algorithm which permits different encodings of the spike timing patterns, including precise spike trains encoding.Comment: 38 pages, 4 figure

Septic processes in colonic surgery

USMF “Carol Davila”, Clinica Chirurgie, Spitalul Clinic de Urgență “Bagdasar-Arseni”, Bucureşti, Serviciul de laborator, Spitalul “Bagdasar Arseni”, București, Catedra Informatică, Facultatea de Medicină, București, Al XI-lea Congres al Asociației Chirurgilor „Nicolae Anestiadi” din Republica Moldova și cea de-a XXXIII-a Reuniune a Chirurgilor din Moldova „Iacomi-Răzeșu” 27-30 septembrie 2011Introducere: În studiul prospectiv a 174 pacienți cu media vârstei de 64,3 ani (limite:19-84 ani) au fost operați pentru afecțiuni chirurgicale ale colonului. Material și metoda: Pentru cancer au fost operați 111(63,79%) pacienți: stadiul clinic II(n = 29;27,3%) și stadiul IV(n = 54;31,03 %). Rezultate: S-a intervenit în urgență la 45(25,86%) pacienți pentru semne clinice ale proceselor septice intraperitoneale (n = 15;13,51%) și pentru sindroame ocluzive (n = 30; 27,02%) dintre care ocluzii intestinale (n = 12;19,04%) în patologia netumorală. Pentru afecțiuni netumorale au fost operați 63(36,21%) pacienți pentru: diverticulita colică (n = = 24;13,79%), polipi colici (n = 20;11,60%), volvulus sigmoid (n = 11;6,32 %), rectocolită ulcerohemoragică și purulentă (n=5;2,29%), boala Crohn (n=3;1,72%). Complicațiile postoperatorii au fost reprezentate de manifestările locale și generale ale proceselor septice intraperitoneale (n = 30;17,24%) și complicațiile septice parietale (n=27%;15,81%). Complicațiile postoperatorii mai frecvente în prima săptămână postoperator: hidroelectrolitice (66,66%), a patra decadă postoperator: septice. Au fost efectuate operații în urgență (n=74;44,2%). Operațiile radicale-11,36%. Prezența preoperatorie a sindromului raspunsului inflamator sistemic și evoluția sa postoperatorie a condus la declansarea sindromului de insuficiență multiplă a organelor, factor de predicție a letalitații postoperatorii (p<0,001). S-au înregistrat 37(21,22%) decese postoperatorii. Dezunirea liniei de anastomoza s-a soldat cu mortalitatea de 100 %. Concluzii: Complicațiile septice în chirurgia colonului au valoare predictivă pozitivă de 60 % în producerea deceselor postoperatorii.Introduction: In a prospective study of 174 patients with mean age of 64.3 years (range:19-84 years) were operated for surgical diseases of the colon.Material and methods: For cancer were operated 111(63.79%) patients: clinical stage II (n = 29,27.3%), IV (n = 54,31.03%).Results: We operated in emergency 45(25.86%) patients for clinical signs of intraperitoneal septic processes (n = 15,13.51%) and occlusive syndromes (n = 30,27.02%) from which intestinal occlusion (n = 12,19.04%) with nontumoral pathology. For nontumoral diseases were operated 63(36.21%) patients for: colic diverticulosis (n = 24, 13.79%), colic polyps (n = 20,11.60%), sigmoid volvulus (n = 11,6.32%), ulcerative ulcerohemorrhagic colitis and purulent (n = 5,2.29%), Crohn’s disease (n = 3,1.72%). Postoperative complications were represented by local and general manifestations of septic processes intraperitoneal (n = 30,17.24%) and parietal septic complications (n = 27%, 15.81%).More frequent postoperative complications in the first week after surgery: electrolytes disorders (66.66% ), the fourth decade after surgery: septic complications. Emergency surgery: n = 74,44.2%;11,36% radical operations. This preoperative systemic inflammatory response syndrome and postoperative evolution led to the outbreak of the syndrome multiple organ failure, a predictor of postoperative lethality (p < 0.001). There were 37(21.22%) postoperative deaths. Dehiscence of anastomosis line resulted in 100% mortality.Conclusions: Septic complications of colon surgery were 60% positive predictive value in producing postoperative deaths