A guide to managing human activity on national wildlife refuges.

78 page

The Real Combination Problem : Panpsychism, Micro-Subjects, and Emergence

Panpsychism harbors an unresolved tension, the seriousness of which has yet to be fully appreciated. I capture this tension as a dilemma, and offer panpsychists advice on how to resolve it. The dilemma, briefly, is as follows. Panpsychists are committed to the perspicuous explanation of macro-mentality in terms of micro-mentality. But panpsychists take the micro-material realm to feature not just mental properties, but also micro-subjects to whom these properties belong. Yet it is impossible to explain the constitution of a macro-subject (like one of us) in terms of the assembly of micro-subjects, for, I show, subjects cannot combine. Therefore the panpsychist explanatory project is derailed by the insistence that the world’s ultimate material constituents (ultimates) are subjects of experience. The panpsychist faces a choice of abandoning her explanatory project, or recanting the claim that the ultimates are subjects. This is the dilemma. I argue that the latter option is to be preferred. This needn’t constitute a wholesale abandonment of panpsychism, however, since panpsychists can maintain that the ultimates possess phenomenal qualities, despite not being subjects of those qualities. This proposal requires us to make sense of phenomenal qualities existing independently of experiencing subjects, a challenge I tackle in the penultimate section. The position eventually reached is a form of neutral monism, so another way to express the overall argument is to say that, keeping true to their philosophical motivations, panpsychists should really be neutral monists.Peer reviewedFinal Accepted Versio

Role of the Netrin-like Domain of Procollagen C-Proteinase Enhancer-1 in the Control of Metalloproteinase Activity

The netrin-like (NTR) domain is a feature of several extracellular proteins, most notably the N-terminal domain of tissue inhibitors of metalloproteinases (TIMPs), where it functions as a strong inhibitor of matrix metalloproteinases and some other members of the metzincin superfamily. The presence of a C-terminal NTR domain in procollagen C-proteinase enhancers (PCPEs), proteins that stimulate the activity of astacin-like tolloid proteinases, raises the possibility that this might also have inhibitory activity. Here we show that both long and short forms of the PCPE-1 NTR domain, the latter beginning at the N-terminal cysteine known to be critical for TIMP activity, show no inhibition, at micromolar concentrations, of several members of the metzincin superfamily, including matrix metalloproteinase-2, bone morphogenetic protein-1 (a tolloid proteinase), and different ADAMTS (a disintegrin and a metalloproteinase with thrombospondin motifs) proteinases from the adamalysin family. In contrast, we report that the NTR domain within PCPE-1 leads to superstimulation of bone morphogenetic protein-1 activity in the presence of heparin and heparan sulfate. These observations point to a new mechanism whereby binding to cell surface-associated or extracellular heparin-like sulfated glycosaminoglycans might provide a means to accelerate procollagen processing in specific cellular and extracellular microenvironments

Classical simulation of measurement-based quantum computation on higher-genus surface-code states

We consider the efficiency of classically simulating measurement-based quantum computation on surface-code states. We devise a method for calculating the elements of the probability distribution for the classical output of the quantum computation. The operational cost of this method is polynomial in the size of the surface-code state, but in the worst case scales as $2^{2g}$ in the genus $g$ of the surface embedding the code. However, there are states in the code space for which the simulation becomes efficient. In general, the simulation cost is exponential in the entanglement contained in a certain effective state, capturing the encoded state, the encoding and the local post-measurement states. The same efficiencies hold, with additional assumptions on the temporal order of measurements and on the tessellations of the code surfaces, for the harder task of sampling from the distribution of the computational output.Comment: 21 pages, 13 figure

Off-diagonal Interactions, Hund's Rules and Pair-binding in Hubbard Molecules

We have studied the effect of including nearest-neighbor, electron-electron interactions, in particular the off-diagonal (non density-density) terms, on the spectra of truncated tetrahedral and icosahedral ``Hubbard molecules,'' focusing on the relevance of these systems to the physics of doped C$_{60}$. Our perturbation theoretic and exact diagonalization results agree with previous work in that the density-density term suppresses pair-binding. However, we find that for the parameter values of interest for $C_{60}$ the off-diagonal terms {\em enhance} pair-binding, though not enough to offset the suppression due to the density-density term. We also find that the critical interaction strengths for the Hund's rules violating level crossings in C$_{60}^{-2}$, C$_{60}^{-3}$ and C$_{60}^{-4}$ are quite insensitive to the inclusion of these additional interactions.Comment: 20p + 5figs, Revtex 3.0, UIUC preprint P-94-10-08

Extreme Mountain Ultra-Marathon Leads to Acute but Transient Increase in Cerebral Water Diffusivity and Plasma Biomarkers Levels Changes.

Background: Pioneer studies demonstrate the impact of extreme sport load on the human brain, leading to threatening conditions for athlete's health such as cerebral edema. The investigation of brain water diffusivity, allowing the measurement of the intercellular water and the assessment of cerebral edema, can give a great contribution to the investigation of the effects of extreme sports on the brain. We therefore assessed the effect of supra-physiological effort (extreme distance and elevation changes) in mountain ultra-marathons (MUMs) athletes combining for the first time brain magnetic resonance imaging (MRI) and blood parameters. Methods:This longitudinal study included 19 volunteers (44.2 ± 9.5 years) finishing a MUM (330 km, elevation + 24000 m). Quantitative measurements of brain diffusion-weighted images (DWI) were performed at 3 time-points: Before the race, upon arrival and after 48 h. Multiple blood biomarkers were simultaneously investigated. Data analyses included brain apparent diffusion coefficient (ADC) and physiological data comparisons between three time-points. Results:The whole brain ADC significantly increased from baseline to arrival (p = 0.005) and then significantly decreased at recovery (p = 0.005) to lower values than at baseline (p = 0.005). While sodium, potassium, calcium, and chloride as well as hematocrit (HCT) changed over time, the serum osmolality remained constant. Significant correlations were found between whole brain ADC changes and osmolality (p = 0.01), cholesterol (p = 0.009), c-reactive protein (p = 0.04), sodium (p = 0.01), and chloride (p = 0.002) plasma level variations. Conclusions:These results suggest the relative increase of the inter-cellular volume upon arrival, and subsequently its reduction to lower values than at baseline, indicating that even after 48 h the brain has not fully recovered to its equilibrium state. Even though serum electrolytes may only indirectly indicate modifications at the brain level due to the blood brain barrier, the results concerning osmolality suggest that body water might directly influence the change in cerebral ADC. These findings establish therefore a direct link between general brain inter-cellular water content and physiological biomarkers modifications produced by extreme sport

Jahn-Teller versus quantum effects in the spin-orbital material LuVO3

We report on combined neutron and resonant x-ray scattering results, identifying the nature of the spin-orbital ground state and magnetic excitations in LuVO3 as driven by the orbital parameter. In particular, we distinguish between models based on orbital Peierls dimerization, taken as a signature of quantum effects in orbitals, and Jahn-Teller distortions, in favor of the latter. In order to solve this long-standing puzzle, polarized neutron beams were employed as a prerequisite in order to solve details of the magnetic structure, which allowed quantitative intensity-analysis of extended magnetic excitation data sets. The results of this detailed study enabled us to draw definite conclusions about classical vs quantum behavior of orbitals in this system and to discard the previous claims about quantum effects dominating the orbital physics of LuVO3 and similar systems.Comment: Phys. Rev. B 91, 161104(R) (2015