The effect of Ku on telomere replication time is mediated by telomere length but is independent of histone tail acetylation

Peer reviewedPublisher PD

Notch effect on the fracture of several rocks: Application of the Theory of Critical Distances

The paper analyses the fracture behaviour of several rocks, namely a sandstone, a limestone and two marbles, one of them being a Carrara marble. The experimental program comprises in total 216 fracture specimens, tested in 4-point bending conditions and including specimens with notch radii varying from 0.15 mm up to 15 mm. The notch effect is analysed through the evolution of the apparent fracture toughness and the application of the Theory of Critical Distances. The present study aims to generalize a previous study on a granite and a limestone to a broader range of rocks. The point and line methods of the Theory of the Critical Distances successfully explain the notch effect on the fracture specimens. The value of the critical distance of these rocks is of the order of mm. Finally, the results show a correlation between the microstructural features of the rocks, specifically the grain size, and their critical distances.The authors of this work would like to express their gratitude to the Spanish Ministry of Economy and Competitiveness for financing the National Plan Project (Ref.: BIA2015-67479-R) under the name of ‘La Distancia Crítica en la Fractura de Rocas’ (The Critical Distance in Rock Fracture)

On the Generalizability of Experimental Results

The age-old question of the generalizability of the results of experiments that are conducted in artificial laboratory settings to more realistic inferential and decision making situations is considered in this paper. Conservatism in probability revision provides an example of a result that 1) has received wide attention, including attention in terms of implications for real-world decision making, on the basis of experiments conducted in artificial settings and 2) is now apparently thought by many to be highly situational and not at all a ubiquitous phenomenon, in which case its implications for real-world decision making are not as extensive as originally claimed. In this paper we consider the questions of generalizations from the laboratory to the real world in some detail, both within the context of the experiments regarding conservatism and within a more general context. In addition, we discuss some of the difficulties inherent in experimentation in realistic settings, suggest possible procedures for avoiding or at least alleviating such difficulties, and make a plea for more realistic experiments

The evolution of degenerative marrow (Modic) changes in the cervical spine in neck pain patients

PURPOSE: To evaluate the natural course of end plate marrow (Modic) changes (MC) in the cervical spine on MRI scans of patients with neck pain. A few longitudinal studies have assessed the development of MC over time in the lumbar spine but only two recent studies evaluated MC in the cervical spine in asymptomatic volunteers and those with whiplash. Thus, this study now reports on the natural course of MC in the cervical spine in symptomatic patients. METHODS: From the cervical MRI scans of 426 neck pain patients (mean age 61.2 years), 64 patients had follow-up MRI studies. The prevalence and types of MC were retrospectively assessed on the follow-up scans and compared to the original MRI findings. RESULTS: With an average of 2.5 years between the two MRI scans, the prevalence of MC type 1 (MC1) noted at baseline (7.4 % or 19 motion segments) slightly increased (8.2 % or 21 segments) but the prevalence of MC2 (14.5 % or 37 segments) increased considerably (22.3 % or 57 segments). In addition, 14 new MC1 segments and 8 new MC2 segments were noted. Twelve segments with MC1 at baseline converted to MC2 at follow-up. No conversion from MC2 to MC1 or reverting to a normal image was observed. CONCLUSIONS: MC in the cervical spine are a dynamic phenomenon similar to the lumbar spine

The MACHO Project Large Magellanic Cloud Variable Star Inventory. VIII. The Recent Star Formation History of the LMC from the Cepheid Period Distribution

We present an analysis of the period distribution of $\sim 1800$ Cepheids in the Large Magellanic Cloud, based on data obtained by the MACHO microlensing experiment and on a previous catalogue by Payne-Gaposchkin. Using stellar evolution and pulsation models, we construct theoretical period-frequency distributions that are compared to the observations. These models reveal that a significant burst of star formation has occurred recently in the LMC ($\sim 1.15\times 10^8$ years). We also show that during the last $\sim 10^8$ years, the main center of star formation has been propagating from SE to NW along the bar. We find that the evolutionary masses of Cepheids are still smaller than pulsation masses by $\sim 7$ % and that the red edge of the Cepheid instability strip could be slightly bluer than indicated by theory. There are $\sim 600$ Cepheids with periods below $\sim 2.5$ days cannot be explained by evolution theory. We suggest that they are anomalous Cepheids; a number of these stars are double-mode Cepheids