The ISCIP Analyst, Volume XVI, Issue 6

This repository item contains a single issue of The ISCIP Analyst, an analytical review journal published from 1996 to 2010 by the Boston University Institute for the Study of Conflict, Ideology, and Policy

The ISCIP Analyst, Volume XVI, Issue 11

This repository item contains a single issue of The ISCIP Analyst, an analytical review journal published from 1996 to 2010 by the Boston University Institute for the Study of Conflict, Ideology, and Policy

The ISCIP Analyst, Volume XVI, Issue 12

This repository item contains a single issue of The ISCIP Analyst, an analytical review journal published from 1996 to 2010 by the Boston University Institute for the Study of Conflict, Ideology, and Policy

Functional cartilage repair capacity of de-differentiated, chondrocyte- and mesenchymal stem cell-laden hydrogels in vitro

SummaryObjectiveThe long-term performance of cell-seeded matrix-based cartilage constructs depends on (1) the development of sufficient biomechanical properties, and (2) lateral integration with host tissues, both of which require cartilage-specific matrix deposition within the scaffold. In this study, we have examined the potential of tissue-engineered cartilage analogs developed using different cell types, i.e., mesenchymal stem cells (MSCs) vs chondrocytes and de-differentiated chondrocytes, in an established “construct in cartilage ring” model.DesignCell-laden constructs of differentiated chondrocytes, de-differentiated chondrocytes after two, five or eight population doublings, and MSCs were either implanted into a native cartilage ring immediately after fabrication (immature group) or pre-treated for 21 days in a transforming growth factor-β3 (TGF-β3) containing medium prior to implantation. After additional culture for 28 days in a serum-free, chemically defined medium, the extent of lateral integration, and biochemical and biomechanical characteristics of the implants as hybrid constructs were assessed.ResultsThe quality of integration, the amount of accumulated cartilage-specific matrix components and associated biomechanical properties were found to be highest when using differentiated chondrocytes. De-differentiation of chondrocytes negatively impacted the properties of the implants, as even two population doublings of the chondrocytes in culture significantly lowered cartilage repair capacity. In contrast, MSCs showed chondrogenic differentiation with TGF-β3 pre-treatment and superior integrational behavior.ConclusionsChondrocyte expansion and de-differentiation impaired the cell response, resulting in inferior cartilage repair in vitro. With TGF-β3 pre-treatment, MSCs were able to undergo sustained chondrogenic differentiation and exhibited superior matrix deposition and integration compared to de-differentiated chondrocytes

Microsatellite DNA-markers in the study of the gene pool of fruit crops

This article describes development of multilocus SSR-markers sets for genotyping Pyrus, Prunus, and Malus from various genetic collections of the South of Russia. Generated multiplex sets of SSR-markers were used in the certification of cultivated varieties and in the analysis of the genetic structure of Pyrus, Prunus and Malus species collections. The results of SSR genotyping of pear, apple, plum and sweet cherry made it possible to establish genetic relationships between varieties, including groups of modern varieties of Russian and foreign breeding and, in turn, local autochthonous varieties. In general, the use of these multiplexes has confirmed their effectiveness in solving the assigned tasks

First low-frequency Einstein@Home all-sky search for continuous gravitational waves in Advanced LIGO data

International audienceWe report results of a deep all-sky search for periodic gravitational waves from isolated neutron stars in data from the first Advanced LIGO observing run. This search investigates the low frequency range of Advanced LIGO data, between 20 and 100 Hz, much of which was not explored in initial LIGO. The search was made possible by the computing power provided by the volunteers of the Einstein@Home project. We find no significant signal candidate and set the most stringent upper limits to date on the amplitude of gravitational wave signals from the target population, corresponding to a sensitivity depth of 48.7  [1/Hz]. At the frequency of best strain sensitivity, near 100 Hz, we set 90% confidence upper limits of 1.8×10-25. At the low end of our frequency range, 20 Hz, we achieve upper limits of 3.9×10-24. At 55 Hz we can exclude sources with ellipticities greater than 10-5 within 100 pc of Earth with fiducial value of the principal moment of inertia of 1038  kg m2

First narrow-band search for continuous gravitational waves from known pulsars in advanced detector data

International audienceSpinning neutron stars asymmetric with respect to their rotation axis are potential sources of continuous gravitational waves for ground-based interferometric detectors. In the case of known pulsars a fully coherent search, based on matched filtering, which uses the position and rotational parameters obtained from electromagnetic observations, can be carried out. Matched filtering maximizes the signal-to-noise (SNR) ratio, but a large sensitivity loss is expected in case of even a very small mismatch between the assumed and the true signal parameters. For this reason, narrow-band analysis methods have been developed, allowing a fully coherent search for gravitational waves from known pulsars over a fraction of a hertz and several spin-down values. In this paper we describe a narrow-band search of 11 pulsars using data from Advanced LIGO’s first observing run. Although we have found several initial outliers, further studies show no significant evidence for the presence of a gravitational wave signal. Finally, we have placed upper limits on the signal strain amplitude lower than the spin-down limit for 5 of the 11 targets over the bands searched; in the case of J1813-1749 the spin-down limit has been beaten for the first time. For an additional 3 targets, the median upper limit across the search bands is below the spin-down limit. This is the most sensitive narrow-band search for continuous gravitational waves carried out so far

Search for intermediate mass black hole binaries in the first observing run of Advanced LIGO

International audienceDuring their first observational run, the two Advanced LIGO detectors attained an unprecedented sensitivity, resulting in the first direct detections of gravitational-wave signals produced by stellar-mass binary black hole systems. This paper reports on an all-sky search for gravitational waves (GWs) from merging intermediate mass black hole binaries (IMBHBs). The combined results from two independent search techniques were used in this study: the first employs a matched-filter algorithm that uses a bank of filters covering the GW signal parameter space, while the second is a generic search for GW transients (bursts). No GWs from IMBHBs were detected; therefore, we constrain the rate of several classes of IMBHB mergers. The most stringent limit is obtained for black holes of individual mass 100  M⊙, with spins aligned with the binary orbital angular momentum. For such systems, the merger rate is constrained to be less than 0.93  Gpc−3 yr−1 in comoving units at the 90% confidence level, an improvement of nearly 2 orders of magnitude over previous upper limits