A loose-leaf manual of experiments in college physics, by James I. Shannon and James B. Macelwane 2d ed. rev.

Mode of access: Internet.

Paikkatietoa yrityksen näkökulmasta

Kirjallisuusarvostelu

Anàlisi genètica i molecular de les malalties Niemann-Pick tipus A/B i tipus C. Estratègies terapèutiques.

Aquest treball es basa en l’estudi de dues malalties lisosòmiques: la malaltia de Niemann-Pick A/B (NPAB) i la malaltia de Niemann-Pick tipus C (NPC). En relació a la malaltia de NPAB, s’ha realitzat l’expressió in vitro d’algunes de les mutacions de canvi d’aminoàcid trobades en pacients espanyols per tal de detectar les activitats enzimàtiques residuals. Totes les mutacions presenten una activitat molt baixa, gairebé nul•la, excepte la p.L225P i la R608del que tenen un 11% i 20% d’activitat respectivament. Els resultats obtinguts són coherents amb la severitat del fenotip que presenten els pacients. D’altra banda, s’ha caracteritzat un al•lel amb una mutació que afecta a una posició poc conservada d’un donador de splicing i que produeix la generació de trànscrits aberrants corresponents a trànscrits minoritaris de SMPD1, prèviament descrits, que no codifiquen per proteïna funcional. Respecte a malaltia de NPC, s’ha realitzat una anàlisi molecular de pacients espanyols prèviament estudiats identificant, en la majoria dels casos, la segona mutació responsable de la patologia. S’ha descrit per primer cop per aquesta malaltia una gran deleció que inclou el gen NPC1 i altres gens flanquejants i s’ha estudiat l’efecte que tenen les mutacions de splicing trobades a nivell de RNA. Per una d’aquestes mutacions, c.1554-1009G&A, s’ha assajat amb èxit una estratègia terapèutica basada en la utilització d’oligonuclèotids antisentit. D’altra banda, s’està desenvolupant un model cel•lular neuronal de la malaltia de Niemann-Pick tipus C, basat en la utilització de RNAs d’interferència, sobre el qual es podran assajar possibles estratègies terapèutiques en un futur.

Ascending thoracic aorta dimension and outcomes in acute type B dissection (from the International Registry of Acute Aortic Dissection [IRAD])

It is not well known if the size of the ascending thoracic aorta at presentation predicts features of presentation, management, and outcomes in patients with acute type B aortic dissection. The International Registry of Acute Aortic Dissection (IRAD) database was queried for all patients with acute type B dissection who had documentation of ascending thoracic aortic size at time of presentation. Patients were categorized according to ascending thoracic aortic diameters ≤4.0, 4.1 to 4.5, and ≥4.6 cm. Four hundred eighteen patients met inclusion criteria; 291 patients (69.6%) were men with a mean age of 63.2 ± 13.5 years. Ascending thoracic aortic diameter ≤4.0 cm was noted in 250 patients (59.8%), 4.1 to 4.5 cm in 105 patients (25.1%), and ≥4.6 cm in 63 patients (15.1%). Patients with an ascending thoracic aortic diameter ≥4.6 cm were more likely to be men (p = 0.01) and have Marfan syndrome (p <0.001) and known bicuspid aortic valve disease (p = 0.003). In patients with an ascending thoracic aorta ≥4.1 cm, there was an increased incidence of surgical intervention (p = 0.013). In those with an ascending thoracic aorta ≥4.6 cm, the root, ascending aorta, arch, and aortic valve were more often involved in surgical repair. Patients with an ascending thoracic aorta ≤4.0 were more likely to have endovascular therapy than those with larger ascending thoracic aortas (p = 0.009). There was no difference in overall mortality or cause of death. In conclusion, ascending thoracic aortic enlargement in patients with acute type B aortic dissection is common. Although its presence does not appear to predict an increased risk of mortality, it is associated with more frequent open surgical intervention that often involves replacement of the proximal aorta. Those with smaller proximal aortas are more likely to receive endovascular therapy.

James Burrill Angell

President of the University of Michigan, minister to China and Turkey. On verso: Card Imperial By Sam B. Revenaugh, 28 Huron street (Upstairs) Ann Arbor, - Mich.

Family of James Burrill Angell

Standing (Adults) L-R: Marion Waterhouse Angell (Mrs. J.R.); James Rowland Angell; Andrew C. McLaughlin; Fanny C. Cooley. Angell (Mrs. A.C.); Alexis Caswell Angell; Sarah Caswell Angell (daughter of A.C), Lois Angell McLaughlin

Middle Row: James Waterhouse Angell (son of J.R.), Marion Angell (McAlpin) (daughter of James R.) James Burrill Angell, Isabel McLaughlin

Front Row: Constance McLaughlin (Green); Robert Cooley Angell (son of A.C.); Esther Lois McLaughlin (Donahue) David Blair McLaughlin; Rowland Hazard McLaughlin; James Burrill Angell II (son of A.C.): James Angell McLaughlin

Memoirs of the life of Sir James Mackintosh,

Mode of access: Internet.

Collision probabilities in the rarefaction fan of asymmetric exclusion processes

We consider the one-dimensional asymmetric simple exclusion process (ASEP) in which particles jump to the right at rate p is an element of (1/2, 1.] and to the left at rate 1 - p, interacting by exclusion. In the initial state there is a finite region such that to the left of this region all sites are occupied and to the right of it all sites are empty. Under this initial state, the hydrodynamical limit of the process converges to the rarefaction fan of the associated Burgers equation. In particular suppose that the initial state has first-class particles to the left of the origin, second-class particles at sites 0 and I, and holes to the right of site I. We show that the probability that the two second-class particles eventually collide is (1 + p)/(3p), where a collision occurs when one of the particles attempts to jump over the other. This also corresponds to the probability that two ASEP processes. started from appropriate initial states and coupled using the so-called ""basic coupling,"" eventually reach the same state. We give various other results about the behaviour of second-class particles in the ASEP. In the totally asymmetric case (p = 1) we explain a further representation in terms of a multi-type particle system, and also use the collision result to derive the probability of coexistence of both clusters in a two-type version of the corner growth model.

A PHASE TRANSITION FOR COMPETITION INTERFACES

We study the competition interface between two growing clusters in a growth model associated to last-passage percolation. When the initial unoccupied set is approximately a cone, we show that this interface has an asymptotic direction with probability 1. The behavior of this direction depends on the angle theta of the cone: for theta >= 180 degrees, the direction is deterministic, while for theta < 180 degrees, it is random, and its distribution can be given explicitly in certain cases. We also obtain partial results on the fluctuations of the interface around its asymptotic direction. The evolution of the competition interface in the growth model can be mapped onto the path of a second-class particle in the totally asymmetric simple exclusion process; from the existence of the limiting direction for the interface, we obtain a new and rather natural proof of the strong law of large numbers (with perhaps a random limit) for the position of the second-class particle at large times.

Multiclass Hammersley-Aldous-Diaconis process and multiclass-customer queues

In the Hammersley-Aldous-Diaconis process, infinitely many particles sit in R and at most one particle is allowed at each position. A particle at x, whose nearest neighbor to the right is at y, jumps at rate y - x to a position uniformly distributed in the interval (x, y). The basic coupling between trajectories with different initial configuration induces a process with different classes of particles. We show that the invariant measures for the two-class process can be obtained as follows. First, a stationary M/M/1 queue is constructed as a function of two homogeneous Poisson processes, the arrivals with rate, and the (attempted) services with rate rho > lambda Then put first class particles at the instants of departures (effective services) and second class particles at the instants of unused services. The procedure is generalized for the n-class case by using n - 1 queues in tandem with n - 1 priority types of customers. A multi-line process is introduced; it consists of a coupling (different from Liggett's basic coupling), having as invariant measure the product of Poisson processes. The definition of the multi-line process involves the dual points of the space-time Poisson process used in the graphical construction of the reversed process. The coupled process is a transformation of the multi-line process and its invariant measure is the transformation described above of the product measure.