Extending the rapeseed gene pool with resynthesized Brassica napus II: Heterosis

Hybrid breeding relies on the combination of parents from two differing heterotic groups. However, the genetic diversity in adapted oilseed rape breeding material is rather limited. Therefore, the use of resynthesized Brassica napus as a distant gene pool was investigated. Hybrids were derived from crosses between 44 resynthesized lines with a diverse genetic background and two male sterile winter oilseed rape tester lines. The hybrids were evaluated together with their parents and check cultivars in 2 years and five locations in Germany. Yield, plant height, seed oil, and protein content were monitored, and genetic distances were estimated with molecular markers (127 polymorphic RFLP fragments). Resynthesized lines varied in yield between 40.9 dt/ha and 21.5 dt/ha, or between 85.1 and 44.6% of check cultivar yields. Relative to check cultivars, hybrids varied from 91.6 to 116.6% in yield and from 94.5 to 103.3% in seed oil content. Mid-parent heterosis varied from −3.5 to 47.2% for yield. The genetic distance of parental lines was not significantly correlated with heterosis or hybrid yield. Although resynthesized lines do not meet the elite rapeseed standards, they are a valuable source for hybrid breeding due to their large distance from present breeding material and their high heterosis when combined with European winter oilseed rape

An updated overview of clinical guidelines for the management of non-specific low back pain in primary care

The aim of this study was to present and compare the content of (inter)national clinical guidelines for the management of low back pain. To rationalise the management of low back pain, evidence-based clinical guidelines have been issued in many countries. Given that the available scientific evidence is the same, irrespective of the country, one would expect these guidelines to include more or less similar recommendations regarding diagnosis and treatment. We updated a previous review that included clinical guidelines published up to and including the year 2000. Guidelines were included that met the following criteria: the target group consisted mainly of primary health care professionals, and the guideline was published in English, German, Finnish, Spanish, Norwegian, or Dutch. Only one guideline per country was included: the one most recently published. This updated review includes national clinical guidelines from 13 countries and 2 international clinical guidelines from Europe published from 2000 until 2008. The content of the guidelines appeared to be quite similar regarding the diagnostic classification (diagnostic triage) and the use of diagnostic and therapeutic interventions. Consistent features for acute low back pain were the early and gradual activation of patients, the discouragement of prescribed bed rest and the recognition of psychosocial factors as risk factors for chronicity. For chronic low back pain, consistent features included supervised exercises, cognitive behavioural therapy and multidisciplinary treatment. However, there are some discrepancies for recommendations regarding spinal manipulation and drug treatment for acute and chronic low back pain. The comparison of international clinical guidelines for the management of low back pain showed that diagnostic and therapeutic recommendations are generally similar. There are also some differences which may be due to a lack of strong evidence regarding these topics or due to differences in local health care systems. The implementation of these clinical guidelines remains a challenge for clinical practice and research

Testing in the incremental design and development of complex products

Testing is an important aspect of design and development which consumes significant time and resource in many companies. However, it has received less research attention than many other activities in product development, and especially, very few publications report empirical studies of engineering testing. Such studies are needed to establish the importance of testing and inform the development of pragmatic support methods. This paper combines insights from literature study with findings from three empirical studies of testing. The case studies concern incrementally developed complex products in the automotive domain. A description of testing practice as observed in these studies is provided, confirming that testing activities are used for multiple purposes depending on the context, and are intertwined with design from start to finish of the development process, not done after it as many models depict. Descriptive process models are developed to indicate some of the key insights, and opportunities for further research are suggested

Joint association of polymorphism of the FGFR4 gene and mutation TP53 gene with bladder cancer prognosis

The impact of the fibroblast growth factor receptor 4 (FGFR4) Gly388Arg polymorphism on bladder cancer is unknown. We found no clear correlations between the FGFR4 genotype and risk of bladder cancer or pathological parameters. Neither the polymorphism nor TP53 mutation status was an independent predictor of prognosis, but they might act jointly on the disease-specific survival of patients

B-RAF and N-RAS Mutations Are Preserved during Short Time In Vitro Propagation and Differentially Impact Prognosis

In melanoma, the RAS/RAF/MEK/ERK signalling pathway is an area of great interest, because it regulates tumor cell proliferation and survival. A varying mutation rate has been reported for B-RAF and N-RAS, which has been largely attributed to the differential source of tumor DNA analyzed, e.g., fixed tumor tissues or in vitro propagated melanoma cells. Notably, this variation also interfered with interpreting the impact of these mutations on the clinical course of the disease. Consequently, we investigated the mutational profile of B-RAF and N-RAS in biopsies and corresponding cell lines from metastatic tumor lesions of 109 melanoma patients (AJCC stage III/IV), and its respective impact on survival. 97 tissue biopsies and 105 biopsy-derived cell lines were screened for B-RAF and N-RAS mutations by PCR single strand conformation polymorphism and DNA sequencing. Mutations were correlated with patient survival data obtained within a median follow-up time of 31 months. B-RAF mutations were detected in 55% tissues and 51% cell lines, N-RAS mutations in 23% tissues and 25% cell lines, respectively. There was strong concordance between the mutational status of tissues and corresponding cell lines, showing a differing status for B-RAF in only 5% and N-RAS in only 6%, respectively. Patients with tumors carrying mutated B-RAF showed an impaired median survival (8.0 versus 11.8 months, p = 0.055, tissues; 7.1 versus 9.3 months, p = 0.068, cell lines), whereas patients with N-RAS-mutated tumors presented with a favorable prognosis (median survival 12.5 versus 7.9 months, p = 0.084, tissues; 15.4 versus 6.8 months, p = 0.0008, cell lines), each in comparison with wildtype gene status. Multivariate analysis qualified N-RAS (p = 0.006) but not B-RAF mutation status as an independent prognostic factor of overall survival. Our findings demonstrate that B-RAF and N-RAS mutations are well preserved during short term in vitro propagation and, most importantly, differentially impact the outcome of melanoma patients

How did the latest increase in fees in England affect student enrolment and inequality?

This paper presents a first analysis of the increase of undergraduate tuition fees to £9,000 (€11.000) in English higher education in 2012. I use a semi-experimental research design to estimate the effect of the reforms, based on student enrolment data drawn from the Higher Education Statistics Agency (HESA). Taking into account possible anticipation effects of the fee increase, I find that enrolment declined by 15 % in the treated groups as a result of the tuition fee increase. This number is almost three times higher than what previous studies have found, and may represent a serious long term cost for the English economy. The decline in enrolments is particularly pronounced for students in older age groups and students from the service class and the middle class. No effect is visible for students from the working class, indicating that the reforms did not lead to a much-feared increase in class bias in higher education enrolment. The reforms also seem not to have exacerbated ethnic inequality in higher education, as all ethnic groups were negatively affected by the reforms. These results are consistent with earlier research in the United States and the United Kingdom, although they expand our understanding of student price responsiveness in other important ways. The paper argues that younger and older students face different costs and benefits. Older students may be less certain about their benefits, and therefore be more sensitive towards price increases. The strong decrease in mature learners may require a policy response, taking into account these differing incentives

Extragalactic Radio Continuum Surveys and the Transformation of Radio Astronomy

Next-generation radio surveys are about to transform radio astronomy by discovering and studying tens of millions of previously unknown radio sources. These surveys will provide new insights to understand the evolution of galaxies, measuring the evolution of the cosmic star formation rate, and rivalling traditional techniques in the measurement of fundamental cosmological parameters. By observing a new volume of observational parameter space, they are also likely to discover unexpected new phenomena. This review traces the evolution of extragalactic radio continuum surveys from the earliest days of radio astronomy to the present, and identifies the challenges that must be overcome to achieve this transformational change.Comment: To be published in Nature Astronomy 18 Sept 201

Requirements Engineering

Requirements Engineering (RE) aims to ensure that systems meet the needs of their stakeholders including users, sponsors, and customers. Often consid- ered as one of the earliest activities in software engineering, it has developed into a set of activities that touch almost every step of the software development process. In this chapter, we reflect on how the need for RE was first recognised and how its foundational concepts were developed. We present the seminal papers on four main activities of the RE process, namely (i) elicitation, (ii) modelling & analysis, (iii) as- surance, and (iv) management & evolution. We also discuss some current research challenges in the area, including security requirements engineering as well as RE for mobile and ubiquitous computing. Finally, we identify some open challenges and research gaps that require further exploration

Kerr/CFT, dipole theories and nonrelativistic CFTs

We study solutions of type IIB supergravity which are SL(2,R) x SU(2) x U(1)^2 invariant deformations of AdS_3 x S^3 x K3 and take the form of products of self-dual spacelike warped AdS_3 and a deformed three-sphere. One of these backgrounds has been recently argued to be relevant for a derivation of Kerr/CFT from string theory, whereas the remaining ones are holographic duals of two-dimensional dipole theories and their S-duals. We show that each of these backgrounds is holographically dual to a deformation of the DLCQ of the D1-D5 CFT by a specific supersymmetric (1,2) operator, which we write down explicitly in terms of twist operators at the free orbifold point. The deforming operator is argued to be exactly marginal with respect to the zero-dimensional nonrelativistic conformal (or Schroedinger) group - which is simply SL(2,R)_L x U(1)_R. Moreover, in the supergravity limit of large N and strong coupling, no other single-trace operators are turned on. We thus propose that the field theory duals to the backgrounds of interest are nonrelativistic CFTs defined by adding the single Schroedinger-invariant (1,2) operator mentioned above to the original CFT action. Our analysis indicates that the rotating extremal black holes we study are best thought of as finite right-moving temperature (non-supersymmetric) states in the above-defined supersymmetric nonrelativistic CFT and hints towards a more general connection between Kerr/CFT and two-dimensional non-relativistic CFTs.Comment: 48+8 pages, 4 figures; minor corrections and references adde