University of Minnesota

About: University of Minnesota is a education organization based out in Minneapolis, Minnesota, United States. It is known for research contribution in the topics: Population & Transplantation. The organization has 117432 authors who have published 257986 publications receiving 11944239 citations. The organization is also known as: University of Minnesota, Twin Cities & University of Minnesota-Twin Cities.

Isolation of a Miller-Dieker lissencephaly gene containing G protein beta-subunit-like repeats

Abstract: Lissencephaly (agyria-pachygyria) is a human brain malformation manifested by a smooth cerebral surface and abnormal neuronal migration. Identification of the gene(s) involved in this disorder would facilitate molecular dissection of normal events in brain development. Type 1 lissencephaly occurs either as an isolated abnormality or in association with dysmorphic facial appearance in patients with Miller-Dieker syndrome. About 15% of patients with isolated lissencephaly and more than 90% of patients with Miller-Dieker syndrome have microdeletions in a critical 350-kilobase region in chromosome 17p13.3 (ref. 6). These deletions are hemizygous, so haplo-insufficiency for a gene in this interval is implicated. Here we report the cloning of a gene (LIS-1, lissencephaly-1) in 17p13.3 that is deleted in Miller-Dieker patients. Non-overlapping deletions involving either the 5' or 3' end of the gene were found in two patients, identifying LIS-1 as the disease gene. The deduced amino-acid sequence shows significant homology to beta-subunits of heterotrimeric G proteins, suggesting that it could possibly be involved in a signal transduction pathway crucial for cerebral development.

Understanding and managing conservation conflicts

Abstract: Conservation conflicts are increasing and need to be managed to minimise negative impacts on biodiversity, human livelihoods, and human well-being. Here, we explore strategies and case studies that highlight the long-term, dynamic nature of conflicts and the challenges to their management. Conflict management requires parties to recognise problems as shared ones, and engage with clear goals, a transparent evidence base, and an awareness of trade-offs. We hypothesise that conservation outcomes will be less durable when conservationists assert their interests to the detriment of others. Effective conflict management and long-term conservation benefit will be enhanced by better integration of the underpinning social context with the material impacts and evaluation of the efficacy of alternative conflict management approaches.

Ionic effects on the elasticity of single DNA molecules

Abstract: We used a force-measuring laser tweezers apparatus to determine the elastic properties of l-bacterio- phage DNA as a function of ionic strength and in the presence of multivalent cations. The electrostatic contribution to the persistence length P varied as the inverse of the ionic strength in monovalent salt, as predicted by the standard worm-like polyelectrolyte model. However, ionic strength is not always the dominant variable in determining the elastic properties of DNA. Monovalent and multivalent ions have quite different effects even when present at the same ionic strength. Multi- valent ions lead to P values as low as 250-300 A, well below the high-salt ''fully neutralized'' value of 450-500 A characteristic of DNA in monovalent salt. The ions Mg 21 and Co(NH3)61 ,i n which the charge is centrally concentrated, yield lower P values than the polyamines putrescine 21 and spermidine 31 ,i n which the charge is linearly distributed. The elastic stretch modulus, S, and P display opposite trends with ionic strength, in contradiction to predictions of macroscopic elasticity the- ory. DNA is well described as a worm-like chain at concen- trations of trivalent cations capable of inducing condensation, if condensation is prevented by keeping the molecule stretched. A retractile force appears in the presence of mul- tivalent cations at molecular extensions that allow intramo- lecular contacts, suggesting condensation in stretched DNA occurs by a ''thermal ratchet'' mechanism.

Sequencing with Earliness and Tardiness Penalties: A Review

Abstract: We consider the problem of scheduling n jobs to minimize the total earliness and tardiness penalty. We review the literature on this topic, providing a framework to show how results have been generalized starting with a basic model that contains symmetric penalties, one machine and a common due date. To this base we add such features as parallel machines, complex penalty functions and distinct due dates. We also consolidate many of the existing results by proving general forms of two key properties of earliness/tardiness models.