A rare intraocular foreign body resulting from a workplace accident.

A 54-year-old man presented to the ophthalmic emergency department of our center with eye pain and blurred vision in his right eye following a workplace accident. Examination revealed a penetrating corneal injury with the presence of an intraocular foreign body (IOFB) involving the corneoscleral limbus, perforating the cornea, iris, anterior lens capsule, and lens. Immediate surgical intervention was carried out with the extraction of the IOFB, identified as an 8mm mussel shell fragment, and the removal of the resulting traumatic cataract. Both preoperative and postoperative examinations showed an attached retina with no signs of retinal tears or vitreous hemorrhage. Appropriate management in this case, along with the timely identification of the agent, led to favorable outcomes despite the size of the intraocular foreign body.

Derivation of the spin-glass order parameter from stochastic thermodynamics.

A fluctuation relation is derived to extract the order parameter function q(x) in weakly ergodic systems. The relation is based on measuring and classifying entropy production fluctuations according to the value of the overlap q between configurations. For a fixed value of q, entropy production fluctuations are Gaussian distributed allowing us to derive the quasi-FDT so characteristic of aging systems. The theory is validated by extracting the q(x) in various types of glassy models. It might be generally applicable to other nonequilibrium systems and experimental small systems.

RACK1 cooperates with NRASQ61K to promote melanoma in vivo.

Melanoma is the deadliest skin cancer. RACK1 (Receptor for activated protein kinase C) protein was proposed as a biological marker of melanoma in human and domestic animal species harboring spontaneous melanomas. As a scaffold protein, RACK1 is able to coordinate the interaction of key signaling molecules implicated in both physiological cellular functions and tumorigenesis. A role for RACK1 in rewiring ERK and JNK signaling pathways in melanoma cell lines had been proposed. Here, we used a genetic approach to test this hypothesis in vivo in the mouse. We show that Rack1 knock-down in the mouse melanoma cell line B16 reduces invasiveness and induces cell differentiation. We have developed the first mouse model for RACK1 gain of function, Tyr::Rack1-HA transgenic mice, targeting RACK1 to melanocytes in vivo. RACK1 overexpression was not sufficient to initiate melanomas despite activated ERK and AKT. However, in a context of melanoma predisposition, RACK1 overexpression reduced latency and increased incidence and metastatic rate. In primary melanoma cells from Tyr::Rack1-HA, Tyr::NRasQ61K mice, activated JNK (c-Jun N-terminal kinase) and activated STAT3 (signal transducer and activator of transcription 3) acted as RACK1 oncogenic partners in tumoral progression. A sequential and coordinated activation of ERK, JNK and STAT3 with RACK1 is shown to accelerate aggressive melanoma development in vivo.

Frozen into stripes: fate of the critical Ising model after a quench.

In this article we study numerically the final state of the two-dimensional ferromagnetic critical Ising model after a quench to zero temperature. Beginning from equilibrium at T_{c}, the system can be blocked in a variety of infinitely long lived stripe states in addition to the ground state. Similar results have already been obtained for an infinite temperature initial condition and an interesting connection to exact percolation crossing probabilities has emerged. Here we complete this picture by providing an example of stripe states precisely related to initial crossing probabilities for various boundary conditions. We thus show that this is not specific to percolation but rather that it depends on the properties of spanning clusters in the initial state.

Fluctuation relation for weakly ergodic aging systems.

A fluctuation relation for aging systems is introduced and verified by extensive numerical simulations. It is based on the hypothesis of partial equilibration over phase-space regions in a scenario of entropy-driven relaxation. The relation provides a simple alternative method, amenable of experimental implementation, to measure replica symmetry breaking parameters in aging systems. The connection with the effective temperatures obtained from the fluctuation-dissipation theorem is discussed.

A comparison of high definition-image enhanced colonoscopy and standard white-light colonoscopy for colorectal polyp detection.

BACKGROUND AND STUDY AIMS: Colonoscopy is widely used to detect and remove precancerous polyps, but fails to detect some polyps. Recent studies evaluating different image-enhanced methods have revealed conflicting results. The efficacy of colonoscopy imaging with simultaneous use of commercially available improvements, including high definition narrow band imaging (HD-NBI), and monochromatic charge-coupled device (CCD) video, was compared with a widely used standard definition white light (SDWL) colonoscopy system for detecting colorectal polyps. The primary aim was to determine whether the combination of image-enhanced colonoscopy systems resulted in fewer missed polyps compared with conventional colonoscopy. PATIENTS AND METHODS: In a randomized controlled trial (Clinicaltrials.gov. study number NCT00825292) patients having routine screening and surveillance underwent tandem colonoscopies with SDWL and image-enhanced (HD-NBI) colonoscopy. The main outcome measurement was the per-polyp false-negative ("miss") rate. Secondary outcomes were adenoma miss rate, and per-patient polyp and adenoma miss rates. RESULTS: 100 patients were randomized and 96 were included in the analysis. In total, 177 polyps were detected; of these, 72 (41 %) were adenomatous. Polyp and adenoma miss rates for SDWL colonoscopy were 57 % (60/105) and 49 % (19/39); those for image-enhanced colonoscopy were 31 % (22/72) and 27 % (9/33) (P = 0.005 and P = 0.036 for polyps and adenomas, respectively). Image-enhanced and SDWL approaches had similar per-patient miss rates for polyps (6/35 vs. 9/32, P = 0.27) and adenomas (4/22 vs. 8/20, P = 0.11). CONCLUSIONS: Utilization of multiple recent improvements in image-enhanced colonoscopy was associated with a reduced miss rate for all polyps and for adenomatous polyps. It is not known which individual feature or combination of image-enhancement features led to the improvement.

Stark effect of interactive electron-hole pairs in spherical semiconductor quantum dots.

We present a theoretical approach, based on the effective mass approximation model, on the quantum-confinement Stark effects for spherical semiconducting quantum dots in the regime of strong confinement of interactive electron-hole pairs and limiting weak electric field. The respective roles of Coulomb potential and polarization energy are investigated in detail. Under reasonable physical assumptions, analytical calculations can be performed. They show that the Stark shift is a quadratic function of the electric field amplitude in this regime. The computed numerical values obtained from this approach are found to be in good agreement with experimental data over a significant domain of quantum dot sizes.

Universality class of the Nishimori point in the 2D +/- J random-bond Ising model.

We study the universality class of the Nishimori point in the 2D +/- J random-bond Ising model by means of the numerical transfer-matrix method. Using the domain-wall free energy, we locate the position of the fixed point along the Nishimori line at the critical concentration value p(c) = 0.1094 +/- 0.0002 and estimate nu = 1.33 +/- 0.03. Then, we obtain the exponents for the moments of the spin-spin correlation functions as well as the value for the central charge c = 0.464 +/- 0.004. The main qualitative result is the fact that percolation is now excluded as a candidate for describing the universality class of this fixed point.

Methodologic pitfalls in the determination of genetic anticipation: the case of Crohn disease.

BACKGROUND: The term genetic anticipation is used when genetically transmitted disease manifests at increasingly younger ages with each succeeding generation: that is, if the offspring of patients develop the disease, they will tend to do so at an earlier age than their parents. In some monogenetic disorders, genetic anticipation has a biological basis in expanded genetic triplet repeats; however, some have claimed that it occurs in polygenic disorders, such as Crohn disease, in which its mechanism cannot be explained. OBJECTIVE: To show how apparent changes in age at diagnosis of Crohn disease between generations, which could suggest genetic anticipation, can be an artifact of inadequate analysis based on age at diagnosis in cohorts that have not been followed for a sufficiently long time. DESIGN: Comparison of ages at diagnosis of Crohn disease among different birth cohorts, before and after adjustment for observation time. SETTING: Meyerhoff Center for Inflammatory Bowel Disease, Johns Hopkins Hospital, Baltimore, Maryland. PATIENTS: 928 consecutive outpatients with Crohn disease. MEASUREMENTS: Trends in age at diagnosis of Crohn disease among birth cohorts were determined by calculating Pearson correlation coefficients and performing Kaplan-Meyer analysis before and after adjustment for observation time. Adjustment for observation time was performed by ensuring that the time during which all included patients were at risk for Crohn disease was equal and that all patients had developed disease by the end of the risk period. RESULTS: Mean age at diagnosis decreased by approximately 5 years with each subsequent 10-year birth cohort on the basis of crude cross-sectional data that could suggest genetic anticipation between generations. However, after adjustment for observation time, the age at diagnosis decreased minimally, if at all, with each successive generation. CONCLUSIONS: Apparent genetic anticipation can be explained by observational biases without invoking any additional genetic influences. Claims for genetic anticipation must be based on methods that properly account for the duration of observation in all persons being studied.

Large-q asymptotics of the random-bond potts model

We numerically examine the large-q asymptotics of the q-state random bond Potts model. Special attention is paid to the parametrization of the critical line, which is determined by combining the loop representation of the transfer matrix with Zamolodchikov's c-theorem. Asymptotically the central charge seems to behave like c(q)=1 / 2 log(2)(q)+O(1). Very accurate values of the bulk magnetic exponent x(1) are then extracted by performing Monte Carlo simulations directly at the critical point. As q-->infinity, these seem to tend to a nontrivial limit, x(1)-->0.192+/-0.002.

Continuous phase transition in a spin-glass model without time-reversal symmetry.

We investigate the phase transition in a strongly disordered short-range three-spin interaction model characterized by the absence of time-reversal symmetry in the Hamiltonian. In the mean-field limit the model is well described by the Adam-Gibbs-DiMarzio scenario for the glass transition; however, in the short-range case this picture turns out to be modified. The model presents a finite temperature continuous phase transition characterized by a divergent spin-glass susceptibility and a negative specific-heat exponent. We expect the nature of the transition in this three-spin model to be the same as the transition in the Edwards-Anderson model in a magnetic field, with the advantage that the strong crossover effects present in the latter case are absent.

Aflatoxin B1 and fumosin B1 in mixed cultures of Aspergillus flavus and Fusarium proliferatum on maize.

Production of aflatoxin B1 and fumonisin B1 in pure and mixed cultures of Aspergillus flavus and Fusarium proliferatum were determined on irradiated maize seeds inoculated with different spore concentrations at 0.97 water activity (a(w)) and a temperature of 25 degrees C. The highest levels of aflatoxin B1 were produced by A. flavus at the lowest levels of inoculum (10(3) spore ml(-1)). There was no spore concentration influence on fumonisin B1 production after 10, 20 and 35 days of incubation. When A. flavus was co-inoculated with F. proliferatum, aflatoxin B1 production was inhibited. The higher the inocula levels of Fusarium produced, the higher the inhibition and this inhibition increased during the incubation period. Total inhibition was reached at 35 days of incubation. There was no interaction influence on fumonisin B1 production at all inoculum levels assayed. These results suggest that under optimal environmental conditions of substrate, water activity and temperature, the interaction between A. flavus and F proliferatum could produce inhibition of aflatoxin B1 and stimulation of fumonisin B1.