Enhancement of tumour growth in two syngeneic C3H murine systems by immunization via the intracaecal route.

Over the past 70 years many experiments have been designed to promote tumour growth. These studies were all carried out in allogeneic tumour systems or by artificially influencing the immunization process. In the present study, the growth of syngeneic mammary tumour cells was enhanced by prior immunization via the intracaecal route. Such induced enhancement could be transferred to untreated animals by serum or by spleen cells. Tumour growth was also enhanced in another syngeneic system by immunization via the intestinal route with frozen-thawed ascites tumour cells. The result is in direct contrast to that obtained by similar immunization with live cells, which affords protection against a later challenge

Some energy conservative schemes for vibro-impacts of a beam on rigid obstacles

Caused by the problem of unilateral contact during vibrations of satellite solar arrays, the aim of this paper is to better understand such a phenomenon. Therefore, it is studied here a simplified model composed by a beam moving between rigid obstacles. Our purpose is to describe and compare some families of fully discretized approximations and their properties, in the case of non-penetration Signorini’s conditions. For this, starting from the works of Dumont and Paoli, we adapt to our beam model the singular dynamic method introduced by Renard. A particular emphasis is given in the use of a restitution coefficient in the impact law. Finally, various numerical results are presented and energy conservation capabilities of the schemes are investigated

The Impact of R&D Offshoring on the Home Knowledge Production of OECD Investing Regions

This paper investigates the relationship between home and offshore R&D activities on the knowledge production of the investing home region. Debate is ongoing on whether R&D offshoring complements the R&D performed at home. In the light of increased offshoring of innovative activities to emerging countries, we explicitly focus on Brazil, Russia, India, China, Singapore and Taiwan. We suggest that complementarity should obtain, when home region and offshore R&D activities are dissimilar as well as when offshore R&D activities is about modular and less complex technologies. We ground our predictions on arguments related to geographical technological specialisation and reverse knowledge transfer from offshore locations to home regions within the more general open innovation trend. Using a theoretical framework based on the international business literature and the regional system of innovation perspective, we estimate a knowledge production function for a sample of 221 regions from 21 OECD countries with home region patent applications as the dependent variable. Our test supports our predictions on the complementarity between home region and offshore R&D.Home Region R&D; Offshore R&D; Knowledge Production; Complementarity; Emerging Countries

Grid of Lya radiation transfer models for the interpretation of distant galaxies

Lya is a key diagnostic for numerous observations of distant star-forming galaxies. It's interpretation requires, however, detailed radiation transfer models. We provide an extensive grid of 3D radiation transfer models simulating the Lya and UV continuum radiation transfer in the interstellar medium of star-forming galaxies. We have improved our Monte Carlo MCLya code, and have used it to compute a grid of 6240 radiation transfer models for homogeneous spherical shells containing HI and dust surrounding a central source. The simulations cover a wide range of parameter space. We present the detailed predictions from our models including in particular the Lya escape fraction fesc, the continuum attenuation, and detailed Lya line profiles. The Lya escape fraction is shown to depend strongly on dust content, but also on other parameters (HI column density and radial velocity). The predicted line profiles show a great diversity of morphologies ranging from broad absorption lines to emission lines with complex features. The results from our simulations are distributed in electronic format. Our models should be of use for the interpretation of observations from distant galaxies, for other simulations, and should also serve as an important base for comparison for future, more refined, radiation transfer models.Comment: Accepted for publication in Astronomy & Astrophysics. Results from simulations available at http://obswww.unige.ch/sf

Role for the fission yeast RecQ helicase in DNA repair in G2.

Members of the RecQ helicase subfamily are mutated in several human genomic instability syndromes, such as Bloom, Werner, and Rothmund-Thomson syndromes. We show that Rqh1, the single Schizosaccharomyces pombe homologue, is a 3'-to-5' helicase and exists with Top3 in a high-molecular-weight complex. top3 deletion is inviable, and this is suppressed by concomitant loss of rqh1 helicase activity or loss of recombination functions. This is consistent with RecQ helicases in other systems. By using epistasis analysis of the UV radiation sensitivity and by analyzing the kinetics of Rhp51 (Rad51 homologue), Rqh1, and Top3 focus formation in response to UV in synchronized cells, we identify the first evidence of a function for Rqh1 and Top3 in the repair of UV-induced DNA damage in G(2). Our data provide evidence that Rqh1 functions after Rad51 focus formation during DNA repair. We also identify a function for Rqh1 upstream of recombination in an Rhp18-dependent (Rad18 homologue) pathway. The model that these data allow us to propose helps to reconcile different interpretations of RecQ family helicase function that have arisen between work based on the S. pombe system and models based on studies of Saccharomyces cerevisiae SGS1 suggesting that RecQ helicases act before Rad51

Serological response to intracaecal injections of antigenic mouse tumour cells.

Immunofluorescence studies of sera from mice with induced enhancement of tumour growth demonstrated that these sera contained factors ("interfering factors") which in an apparently competitive manner interfered with the subsequent binding of specific antibodies to antigenic sites on the tumour-cell membrane. The factors were tumour-specific but lacked some of the immunoglobulin determinants. They could not be detected by polyvalent FITC-antimouse gamma-globulin. Interfering factors did not seem to be related to IgA or IgE. They were demonstrable in sera from tumour-free animals without growing tumours, thus differing from the tumour-specific "blocking factors"

Preference-for-Solitude and Adjustment Difficulties in Early and Late Adolescence

Social withdrawal has been associated with adjustment difficulties across development. Although much is known about shyness, little is known about preference-for-solitude; even less is known about its relations with adjustment across different periods of adolescence. We examined whether preference-for-solitude might be differentially associated with adjustment difficulties in early and late adolescence. Self- and parent-reports of withdrawal motivations and adjustment were collected from 234 eighth graders (113 boys; M age = 13.43) and 204 twelfth graders (91 boys; M age = 17.25). Results from structural equation modeling demonstrated that above and beyond the effects of shyness, preference-for-solitude was more strongly associated with adjustment difficulties in 8th grade than in 12th grade. Preference-for-solitude was associated with greater anxiety/depression, emotion dysregulation, and lower self-esteem in 8th grade; these relations were not found in 12th grade. Although preference-for-solitude was associated with lower social competence in both 8th and 12th grades, this relation was significantly stronger in 8th grade than in 12th grade. Findings suggest preference-for-solitude has closer ties to maladjustment in early adolescence than in late adolescence. Interventions targeting preferred-solitary youth in early adolescence may be particularly fruitfu

Deep rest-frame far-UV spectroscopy of the giant Lyman-alpha emitter 'Himiko'

We present deep 10h VLT/XSHOOTER spectroscopy for an extraordinarily luminous and extended Lya emitter at z=6.595 referred to as Himiko and first discussed by Ouchi et al. (2009), with the purpose of constraining the mechanisms powering its strong emission. Complementary to the spectrum, we discuss NIR imaging data from the CANDELS survey. We find neither for HeII nor any metal line a significant excess, with 3 sigma upper limits of 6.8, 3.1, and 5.8x10^{-18} erg/s/cm^2 for CIV $\lambda$1549, HeII $\lambda$1640, CIII] $\lambda$1909, respectively, assuming apertures with 200 km/s widths and offset by -250 km/s w.r.t to the peak Lya redshift. These limits provide strong evidence that an AGN is not a major contribution to Himiko's Lya flux. Strong conclusions about the presence of PopIII star-formation or gravitational cooling radiation are not possible based on the obtained HeII upper limit. Our Lya spectrum confirms both spatial extent and flux (8.8+/-0.5x10^{-17} erg/s/cm^2) of previous measurements. In addition, we can unambiguously exclude any remaining chance of it being a lower redshift interloper by significantly detecting a continuum redwards of Lya, while being undetected bluewards