Disorders of the brain can exhibit considerable epidemiological comorbidity and often share symptoms, provoking debate about their etiologic overlap. We quantified the genetic sharing of 25 brain disorders from genome-wide association studies of 265,218 patients and 784,643 control participants and assessed their relationship to 17 phenotypes from 1,191,588 individuals. Psychiatric disorders share common variant risk, whereas neurological disorders appear more distinct from one another and from the psychiatric disorders. We also identified significant sharing between disorders and a number of brain phenotypes, including cognitive measures. Further, we conducted simulations to explore how statistical power, diagnostic misclassification, and phenotypic heterogeneity affect genetic correlations. These results highlight the importance of common genetic variation as a risk factor for brain disorders and the value of heritability-based methods in understanding their etiology.

Schizophrenia is thought to be a multifactorial disease with complex mode of inheritance. Using a two-stage strategy for another complex disorder, a number of putative IDDM-susceptibility genes have recently been mapped. We now report the results of a two-stage genome-wide search for genes conferring susceptibility to schizophrenia. In stage I, model-free linkage analyses of large pedigrees from Iceland, a geographical isolate, revealed 26 loci suggestive of linkage. In stage II, ten of these were followed-up in a second international collaborative study comprising families from Austria, Canada, Germany, Italy, Scotland, Sweden, Taiwan and the United States. Potential linkage findings of stage I on chromosomes 6p, 9 and 20 were observed again in the second sample. Furthermore, in a third sample from China, fine mapping of the 6p region by association studies also showed evidence for linkage or linkage disequilibrium. Combining our results with other recent findings revealed significant evidence for linkage to an area distal of the HLA region on chromosome 6p. However, in a fourth sample from Europe, the 6p fine mapping finding observed in the Chinese sample could not be replicated. Finally, evidence suggestive of locus heterogeneity and oligogenic transmission in schizophrenia was obtained.

We introduce a class of multiparticle entanglement purification protocols that allow us to distill a large class of entangled states. These include cluster states, GHZ states and various error correction codes all of which belong to the class of two-colorable graph states. We analyze these schemes under realistic conditions and observe that they are scalable, i.e. the threshold value for imperfect local operations does not depend on the number of parties for many of these states. When compared to schemes based on bipartite entanglement purification, the protocol is more efficient and the achievable quality of the purified states is larger. As an application we discuss an experimental realization of the protocol in optical lattices which allows one to purify cluster states.PACS numbers: 03.67.Mn, 03.67.Pp Entangled states of multi-partite systems are expected to play a significant role for applications in quantum computation and quantum communication. Quantum errorcorrecting codes, as the most prominent example, are highly entangled states which are used to encode quantum information and to protect it against the damaging effects of decoherence. It has been shown that similar entangled states may be used in multi-party communication scenarios beyond teleportation and quantum key distribution [1], such as secret sharing or secure function evaluation [2,3], but also in more practical applications such as the improvement of existing frequency standards [4]. In the context of quantum computation, specific multipartite entangled states -the so-called cluster states [5] -have even been shown to constitute a universal resource for measurement-based quantum computation [6]. These states can be created e.g. via an Ising interaction between neighboring particles on a lattice. A specific realization of such a system is based on neutral atoms in an optical lattice where, starting from a Mott-insulator state [7], cluster states could be created by a simple interferometric process [5,8].When talking about entanglement, it is mandatory to consider the effect of decoherence. Finite temperature (in the case of interacting particles) or a noisy communication channel (in the case of distributed quantum systems) lead to decoherence in the state space of the information carriers, with a rate that increases typically in proportion with the number of particles. Therefore only mixed states rather than pure states will be available, and the achievable fidelity is expected to decrease exponentially both with time and with the size of the system. It is thus not clear whether an entangled state of a large number of particles can be created and maintained in practice.Standard methods have been developed to stabilize quantum states against the detrimental effects of decoherence and noise. Quantum error correction is one general method, but the acceptable noise level for the quantum operations is extremely small (of the order of 10 −4 ) [9]. Entanglement purification [10,11] is an alternative, but protocols exist only for the purification ...

This preliminary study had limited power to detect differences but the trends observed suggest this kind of research is practicable and that further studies are warranted.

Abstract. Expression of human immunodeficiency virus type 1 (HIV-1) structural proteins requires the presence of the viral trans-activator protein Rev. Rev is localized in the nucleus and binds specifically to the Rev response element (RRE) sequence in viral RNA. Furthermore, the interaction of the Rev activation domain with a cellular cofactor is essential for Rev function in vivo. Using cross-linking experiments and Biospecific Interaction Analysis (BIA) we identify eukaryotic initiation factor 5A (elF-5A) as a cellular factor binding specifically to the HIV-1 Rev activation domain. Indirect immunofluorescence studies demonstrate that a significant fraction of elF-5A localizes to the nucleus. We also provide evidence that Rev transactivation is functionally mediated by elF-5A in Xenopus oocytes. Furthermore, we are able to block Rev function in mammalian cells by antisense inhibition of elF-5A gene expression. Thus, regulation of HIV-1 gene expression by Rev involves the targeting of RREcontaining RNA to components of the cellular translation initiation complex.

No abstract

Family and twin studies have suggested a genetic component in autism. We performed a genome-wide screen with 264 microsatellites markers in 51 multiplex families, using non-parametric linkage methods. Families were recruited by a collaborative group including clinicians from Sweden, France, Norway, the USA, Italy, Austria and Belgium. Using two-point and multipoint affected sib-pair analyses, 11 regions gave nominal P -values of 0.05 or lower. Four of these regions overlapped with regions on chromosomes 2q, 7q, 16p and 19p identified by the first genome-wide scan of autism performed by the International Molecular Genetic Study of Autism Consortium. Another of our potential susceptibility regions overlapped with the 15q11-q13 region identified in previous candidate gene studies. Our study revealed six additional regions on chromosomes 4q, 5p, 6q, 10q, 18q and Xp. We found that the most significant multipoint linkage was close to marker D6S283 (maximum lod score = 2.23, P = 0.0013).

Variability among individuals in their therapeutic