On the relation of Voevodsky's algebraic cobordism to Quillen's K-theory

Quillen's algebraic K-theory is reconstructed via Voevodsky's algebraic cobordism. More precisely, for a ground field k the algebraic cobordism P^1-spectrum MGL of Voevodsky is considered as a commutative P^1-ring spectrum. There is a unique ring morphism MGL^{2*,*}(k)--> Z which sends the class [X]_{MGL} of a smooth projective k-variety X to the Euler characteristic of the structure sheaf of X. Our main result states that there is a canonical grade preserving isomorphism of ring cohomology theories MGL^{*,*}(X,U) \tensor_{MGL^{2*,*}(k)} Z --> K^{TT}_{- *}(X,U) = K'_{- *}(X-U)} on the category of smooth k-varieties, where K^{TT}_* is Thomason-Trobaugh K-theory and K'_* is Quillen's K'-theory. In particular, the left hand side is a ring cohomology theory. Moreover both theories are oriented and the isomorphism above respects the orientations. The result is an algebraic version of a theorem due to Conner and Floyd. That theorem reconstructs complex K-theory via complex cobordism.Comment: LaTeX, 18 pages, uses XY-pi

Agent-Based Modeling of Intracellular Transport

We develop an agent-based model of the motion and pattern formation of vesicles. These intracellular particles can be found in four different modes of (undirected and directed) motion and can fuse with other vesicles. While the size of vesicles follows a log-normal distribution that changes over time due to fusion processes, their spatial distribution gives rise to distinct patterns. Their occurrence depends on the concentration of proteins which are synthesized based on the transcriptional activities of some genes. Hence, differences in these spatio-temporal vesicle patterns allow indirect conclusions about the (unknown) impact of these genes. By means of agent-based computer simulations we are able to reproduce such patterns on real temporal and spatial scales. Our modeling approach is based on Brownian agents with an internal degree of freedom, $\theta$, that represents the different modes of motion. Conditions inside the cell are modeled by an effective potential that differs for agents dependent on their value $\theta$. Agent's motion in this effective potential is modeled by an overdampted Langevin equation, changes of $\theta$ are modeled as stochastic transitions with values obtained from experiments, and fusion events are modeled as space-dependent stochastic transitions. Our results for the spatio-temporal vesicle patterns can be used for a statistical comparison with experiments. We also derive hypotheses of how the silencing of some genes may affect the intracellular transport, and point to generalizations of the model

Entry in the ADHD drugs market: Welfare impact of generics and me-toos

Recent decades have seen a growth in treatments for attention deficit hyperactivity disorder (ADHD) including many branded and generic drugs. In the early 2000's, new drug entry dramatically altered market shares. We estimate a demand system for ADHD drugs and assess the welfare impact of new drugs. We find that entry induced large welfare gains by reducing prices of substitute drugs, and by providing alternative delivery mechanisms for existing molecules. Our results suggest that the success of follow-on patented drugs may come from unanticipated innovations like delivery mechanisms, a factor ignored by proposals to retard new follow-on drug approvals

Survival and cause-specific mortality of female eastern wild turkeys in two frequently-burned longleaf pine savannas

Longleaf pine savannas have declined throughout the southeastern United States due to land-use change. Fortunately, natural resource professionals are currently restoring these ecologically and economically important savannas. Although efforts are underway to restore longleaf pine savannas, little information exists on female eastern wild turkey Meleagris gallopavo silvestris population dynamics in these systems. Therefore, we evaluated survival and cause-specific mortality of female eastern wild turkeys in two longleaf pine savannas in southwestern Georgia. We radio-marked 126 female wild turkeys during 2010–2013 and monitored their survival; 66 (52.4%) radio-marked females died during the study. We estimated causes of death for 37 mortality events with predation serving as the leading known cause of mortality, with 35.1% of mortalities attributed to mesocarnivore predation (e.g., bobcat Lynx rufus, coyote Canis latrans, and gray fox Urocyon cinereoargenteus) and 18.9% to great-horned owl Bubo virginianus predation. One female (2.7%) was hit by a vehicle. Seasonal survival estimates varied from a high during fall (Ŝ = 0.94; 95% CI: 0.86–1.00) to a low during spring (Ŝ = 0.76; 95% CI: 0.68–0.87). Survival of incubating females was 0.82 (95% CI: 0.71–0.93) and survival of nonincubating females was 0.67 (95% CI: 0.52–0.87). Annual survival was 0.55 (95% CI: 0.44–0.67). To ensure sustainable wild turkey populations in longleaf pine savannas, we suggest managers monitor relationships between survival and population productivity

Survival and cause-specific mortality of female eastern wild turkeys in two frequently-burned longleaf pine savannas

Longleaf pine savannas have declined throughout the southeastern United States due to land-use change. Fortunately, natural resource professionals are currently restoring these ecologically and economically important savannas. Although efforts are underway to restore longleaf pine savannas, little information exists on female eastern wild turkey Meleagris gallopavo silvestris population dynamics in these systems. Therefore, we evaluated survival and cause-specific mortality of female eastern wild turkeys in two longleaf pine savannas in southwestern Georgia. We radio-marked 126 female wild turkeys during 2010–2013 and monitored their survival; 66 (52.4%) radio-marked females died during the study. We estimated causes of death for 37 mortality events with predation serving as the leading known cause of mortality, with 35.1% of mortalities attributed to mesocarnivore predation (e.g., bobcat Lynx rufus, coyote Canis latrans, and gray fox Urocyon cinereoargenteus) and 18.9% to great-horned owl Bubo virginianus predation. One female (2.7%) was hit by a vehicle. Seasonal survival estimates varied from a high during fall (Ŝ = 0.94; 95% CI: 0.86–1.00) to a low during spring (Ŝ = 0.76; 95% CI: 0.68–0.87). Survival of incubating females was 0.82 (95% CI: 0.71–0.93) and survival of nonincubating females was 0.67 (95% CI: 0.52–0.87). Annual survival was 0.55 (95% CI: 0.44–0.67). To ensure sustainable wild turkey populations in longleaf pine savannas, we suggest managers monitor relationships between survival and population productivity

Prospek Jawawut (Pennisetum Spp. ) sebagai Tanaman Pangan Serealia Alternatif

Untuk meningkatkan ketahanan pangan dan diversifikasi pangan, Indonesia dapatmemanfaatkan lahan kering yang cukup luas jumlahnya. Jawawut (Pennisetumspp.) memiliki potensi yang sangat baik sebagai tanaman pangan alternatifditinjau dari aspek kandungan gizi, dan kemampuan tumbuhnya di daerahberiklim kering. Dilihat dari segi kandungan gizinya, jawawut berpotensi sebagaisumber energi, protein, kalsium, vitamin B1, riboflavin (vitamin B2), sedangkannutrisi lainnya setara dengan beras. Potensi hasil yang dapat dicapai di Indonesiaadalah 4 ton per ha pada kondisi agroekologi yang marginal, dimanapertumbuhan serealia lainnya kurang berhasil. Jawawut dipanen sebagai tanamanpangan semusim

A Membrane Defect in the Pathogenesis of the Smith-Lemli-Opitz Syndrome

The Smith-Lemli-Opitz syndrome (SLOS) is an often lethal birth defect resulting from mutations in the gene responsible for the synthesis of the enzyme 3beta-hydroxy-steroid-Delta7-reductase, which catalyzes the reduction of the double bond at carbon 7 on 7-dehydrocholesterol (7-DHC) to form unesterified cholesterol. We hypothesize that the deficiency in cholesterol biosynthesis and subsequent accumulation of 7-DHC in the cell membrane leads to defective composition, organization, dynamics, and function of the cell membrane. Using skin fibroblasts obtained from SLOS patients, we demonstrate that the SLOS membrane has increased 7-DHC and reduced cholesterol content and abnormal membrane fluidity. X-ray diffraction analyses of synthetic membranes prepared to mimic SLOS membranes revealed atypical membrane organization. In addition, calcium permeability is markedly augmented, whereas membrane-bound Na+/K+ATPase activity, folate uptake, inositol-1,4,5-trisphosphate signaling, and cell proliferation rates are markedly suppressed. These data indicate that the disturbance in membrane sterol content in SLOS, likely at the level of membrane caveolae, directly contributes to the widespread tissue abnormalities in this disease

The Social and Cultural Context of Coping with Sickle Cell Disease: III. Stress, Coping Tasks, Family Functioning, and Children’s Adjustment

Conceptions of individual and family coping with sickle cell disease (SCD) must incorporate several disease and sociocultural factors. This article proposes an integrative model and tests the relative contribution of model parameters to the prediction of social, academic, and psychological adjustment of children with SCD. The individual coping and family functioning variables most highly predictive of the child’s psychological outcomes (anxiety, depression, and positive mood) include parental psychological functioning, maturity demands made of the ill child, and the quality of relations with parents and siblings. Academic adjustment was significantly predicted by parental academic expectations and by the child’s rejection of a restrictive sick role. Competent social functioning also was predicted by the extent to which the ill child rejected the role of being sick.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67288/2/10.1177_0095798499025003006.pd