Conditioning an additive functional of a markov chain to stay nonnegative. II, Hitting a high level

Let (X-t)(t >= 0) be a continuous-time irreducible Markov chain on a finite state space E, let v: E -> R \ {0}, and let (phi(t))(t >= 0) be defined by phi(t) = integral(0)(t) v(X-s) ds. We consider the case in which the process (phi(t))(t >= 0) is oscillating and that in which (phi(t))(t >= 0) has a negative drift. In each of these cases, we condition the process (X-t, phi(t))(t >= 0) on the event that (phi(t))(t >= 0) hits level y before hitting 0 and prove weak convergence of the conditioned process as y -> infinity. In addition, we show the relationship between the conditioning of the process (phi(t))(t >= 0) with a negative drift to oscillate and the conditioning of it to stay nonnegative for a long time, and the relationship between the conditioning of (phi(t))(t >= 0) with a negative drift to drift to infinity and the conditioning of it to hit large levels before hitting 0

Conditioning an additive functional of a markov chain to stay non-negative. I, Survival for a long time

Let (X-t)(t >= 0) be a continuous-time irreducible Markov chain on a finite state space E, let v be a map v: E -> R \ {0}, and let (phi(t))(t >= 0) be an additive functional defined by phi(t) = integral(0)(t)(X-s) ds. We consider the case in which the process (phi(t))(t >= 0) is oscillating and that in which (phi(t))(t >= 0) has a negative drift. In each of these cases, we condition the process (X-t, phi(t))(t >= 0) on the event that (phi(t))(t >= 0) is nonnegative until time T and prove weak convergence of the conditioned process as T -> infinity

Relationship between the vertical craniofacial disproportions and the cervicovertebral morphology in adult subjects

Introduction Orthodontic diagnosis includes the interpretation of the relations between the craniofacial and cervical system, given the potential impact of the irregularities from one system to another. Objective The aim of this study was to examine morphological characteristics of the cervical spine, depending on the parameters of the vertical craniofacial growth and gender in adult subjects. Methods The sample comprised lateral cephalograms of 120 subjects with different vertical facial growth, aged 17.5-35 years. Measured parameters were the following: anterior and posterior vertebral body height (ABHC2-C5, PBHC2-C5), anterior and posterior intervertebral space (AISC2-C5, PISC2-C5), distance between vertebrae and point sella (SC2, SC3, SC4), pterygomaxillare (PmC2), gonion (GoC2) and basion (BaC4); cervical spine angulation (OPT/CVT ) and inclination (OPT/HOR, CVT/HOR). Results Results showed that subjects with anterior facial growth rotation have greater values for BaC4, OPT/HOR, CVT/HOR, OPT/CVT, anterior and posterior vertebral body heights and intervertebral spaces, and lower values for GoC2 and PmC2. Higher values in males were found for anterior and posterior vertebral body heights, distances SC2, SC3, SC4, and BaC4. In females, the greater values were found for GoC2 and ORT/SVT. Conclusion Subjects with anterior facial growth rotation have greater cervical spine inclination and angulation, higher cervical vertebrae and intervertebral spaces, longer upper cervical spines and shorter distances GoC2 and PmC2. Males show smaller cervical column curvature, but higher cervical vertebrae and greater length of the upper cervical spine.Uvod Ortodontska dijagnostika obuhvata tumačenje odnosa između kraniofacijalnog i cervikalnog sistema, pri čemu se ima u vidu potencijalni uticaj nepravilnosti jednog sistema na drugi. Cilj rada Cilj ove studije bio je da se ispitaju morfološke odlike cervikalnog dela kičmenog stuba u zavisnosti od vertikalnog kraniofacijalnog rasta i pola kod ispitanika sa završenim rastom. Metode rada Uzorak se sastojao od profilnih telerend- genskih snimaka 120 ispitanika s različitim vertikalnim kraniofacijalnim rastom, uzrasta od 17,5 do 35 godina. Na snimcima su mereni: prednja i zadnja visina tela pršljena (ABHC2-ABHC5, PBHC2-PBHC5), visina prednjeg i zadnjeg međupršljenskog prostora (AISC2-C5, PISC2-C5); rastojanje pršljenova od tačke sela (SC2, SC3, SC4), pterigomaksilare (PmC2), gonion (GoC2) i bazion (BaC4); angulacija (OPT/CVT) i inklinacija (OPT/HOR, CVT/HOR) cervikalnog dela kičme. Rezultati Rezultati su pokazali da su kod ispitanika s rastom lica prednjom rotacijom veće vrednosti za BaC4, OPT/HOR, CVT/HOR, OPT/CVT, prednje i zadnje visine tela pršljenova i međupršljenskih prostora, dok su vertikalna rastojanja GoC2 i PmC2 pokazala manje vrednosti. U grupi ispitanika muškog pola veće vrednosti pokazale su prednje i zadnje visine tela pršljenova, rastojanja SC2, SC3, SC4 i BaC4. Kod osoba ženskog pola veće vrednosti su bile za rastojanje GoC2 i ugao OPT/CVT. Zaključak Karakteristike osoba s rastom lica prednjom rotacijom su veća inklinacija i zakrivljenost cervikalne kičme, veće visine vratnih pršljenova i međupršljenskih prostora, veća dužina gornjeg dela cervikalne kičme i manja rastojanja GoC2 i PmC2. Kod osoba muškog pola uočava se manja zakrivljenost cervikalne kičme, ali veća visina vratnih pršljenova i veća dužina gornjeg dela cervikalne kičme

Ligand detection and discrimination by spatial relocalization: A kinase-phosphatase segregation model of TCR activation

We develop a model of tyrosine phosphorylation and activation of the T-cell receptor (TCR) by localization to regions of close membrane-membrane proximity ( close contact) that physically exclude tyrosine phosphatases such as CD45. Phosphatase exclusion generates regions of low phosphatase and high kinase activity and thus our model provides a framework to examine the kinetic segregation model of TCR activation. We incorporate a sequence of activation steps modeling the construction of the signalosome with a final sequestered, or high-stability, signaling state. The residence time of unbound TCRs in tyrosine kinase-rich domains is shown to be too short for accumulation of activation steps, whereas binding to an agonist lengthens the localization time and leads to generation of fully active TCRs. Agonist detection depends only on this localization, and therefore kinetic segregation represents a viable ligand detection mechanism, or signal transduction mechanism across membranes, distinct from receptor oligomerization and conformational change. We examine the degree of discrimination of agonists from a background of null ( self) peptides, and from weak agonists achievable by this mechanism

The globalizability of temporal discounting

Economic inequality is associated with preferences for smaller, immediate gains over larger, delayed ones. Such temporal discounting may feed into rising global inequality, yet it is unclear whether it is a function of choice preferences or norms, or rather the absence of sufficient resources for immediate needs. It is also not clear whether these reflect true differences in choice patterns between income groups. We tested temporal discounting and five intertemporal choice anomalies using local currencies and value standards in 61 countries (N = 13,629). Across a diverse sample, we found consistent, robust rates of choice anomalies. Lower-income groups were not significantly different, but economic inequality and broader financial circumstances were clearly correlated with population choice patterns