Mechanisms Affecting Recruitment of Yellow Perch in Lake Michigan

Report issued on: August 2001INHS Technical Report prepared for Great Lakes Fishery Trus

Representations and descriptors unifying the study of molecular and bulk systems

Establishing a unified framework for describing the structures of molecular and periodic systems is a long-standing challenge in physics, chemistry, and material science. With the rise of machine learning methods in these fields, there is a growing need for such a method. This perspective aims to discuss the development and use of three promising approaches-topological, atom-density, and symmetry-based-for the prediction and rationalization of physical, chemical, and mechanical properties of atomistic systems across different scales and compositions

Two‐step dialogue between the cladoceran Bosmina and invertebrate predators: Induction and natural selection

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/110085/1/lno20105510403.pd

Women Booksellers in Eighteenth-Century London and Religious Dissent: Faith, Community and Trade

Women Booksellers in Eighteenth-Century London and Religious Dissent: Faith, Community and Trade Abstract The purpose of this study is to establish the extent of the influence of Protestant dissent on the careers of women booksellers in eighteenth-century London. It offers case studies that reconstruct the lives and careers of five women booksellers at work in the London book trades from 1691 until 1813. This thesis establishes that these women were amongst the most prolific publishers of nonconformist, evangelical and abolitionist texts during the period. They were not merely caretaker widows operating businesses until their sons were old enough to take over. On the contrary, these women demonstrate agency, autonomy, commitment, economic independence and the professional skills needed for the operation of successful publishing businesses. This investigation reveals the culture and robust framework for textual production that nonconformists provided and the commitment, skills and loyalty of their women booksellers who adapted their sales and working practices to the requirements of their nonconformist denominations. It reveals how they worked alongside close communities that included their families, religious denominations and book trade colleagues. These were literate, middle-class women, skilled in their profession who operated succession businesses located in the centre of the book trade in the City of London. Each case study examines the relationship between a woman bookseller and her nonconformist denomination, assessing the extent of her commitment to her faith through her work. Nonconformist women booksellers, though few, were amongst the leading women publishers throughout the eighteenth century. The thesis also uncovers the conditions and circumstances that enabled their exceptional participation and contribution to the literary, public and, in some instances, political spheres

Changes to zooplankton community structure following colonization of a small lake by Leptodora kindti

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/109963/1/lno2004494part21239.pd

Wetting and contact-line effects for spherical and cylindrical droplets on graphene layers: A comparative molecular-dynamics investigation

In Molecular Dynamics (MD) simulations, interactions between water molecules and graphitic surfaces are often modeled as a simple Lennard-Jones potential between oxygen and carbon atoms. A possible method for tuning this parameter consists of simulating a water nanodroplet on a flat graphitic surface, measuring the equilibrium contact angle, extrapolating it to the limit of a macroscopic droplet and finally matching this quantity to experimental results. Considering recent evidence demonstrating that the contact angle of water on a graphitic plane is much higher than what was previously reported, we estimate the oxygen-carbon interaction for the recent SPC/Fwwater model. Results indicate a value of about 0.2 kJ/mol, much lower than previous estimations. We then perform simulations of cylindrical water filaments on graphitic surfaces, in order to compare and correlate contact angles resulting from these two different systems. Results suggest that modified Young's equation does not describe the relation between contact angle and drop size in the case of extremely small systems and that contributions different from the one deriving from contact line tension should be taken into account.Comment: To be published on Physical Review E (http://pre.aps.org/

Mechanism of Molybdenum-Mediated Carbon Monoxide Deoxygenation and Coupling: Mono- and Dicarbyne Complexes Precede C–O Bond Cleavage and C–C Bond Formation

Deoxygenative coupling of CO to value-added C_(≥2) products is challenging and mechanistically poorly understood. Herein, we report a mechanistic investigation into the reductive coupling of CO, which provides new fundamental insights into a multielectron bond-breaking and bond-making transformation. In our studies, the formation of a bis(siloxycarbyne) complex precedes C–O bond cleavage. At −78 °C, over days, C–C coupling occurs without C–O cleavage. However, upon warming to 0 °C, C–O cleavage is observed from this bis(siloxycarbyne) complex. A siloxycarbyne/CO species undergoes C–O bond cleavage at lower temperatures, indicating that monosilylation, and a more electron-rich Mo center, favors deoxygenative pathways. From the bis(siloxycarbyne), isotopic labeling experiments and kinetics are consistent with a mechanism involving unimolecular silyl loss or C–O cleavage as rate-determining steps toward carbide formation. Reduction of Mo(IV) CO adducts of carbide and silylcarbyne species allowed for the spectroscopic detection of reduced silylcarbyne/CO and mixed silylcarbyne/siloxycarbyne complexes, respectively. Upon warming, both of these silylcarbynes undergo C–C bond formation, releasing silylated C_2O_1 fragments and demonstrating that the multiple bonded terminal Mo≡C moiety is an intermediate on the path to deoxygenated, C–C coupled products. The electronic structures of Mo carbide and carbyne species were investigated quantum mechanically. Overall, the present studies establish the elementary reactions steps by which CO is cleaved and coupled at a single metal site

Examining Visual Field Loss in Patients in Glaucoma Clinics During Their Predicted Remaining Lifetime

Purpose.: To evaluate the proportion of patients in glaucoma clinics progressing at rates that would result in visual disability within their expected lifetime. Methods.: This retrospective study used visual field (VF) series of at least 3 years’ duration from 3790 UK patients in glaucoma clinics calculating rates of loss for each eye using linear regression of mean deviation (MD) over time. Residual life expectancies derived from the UK Office of National Statistics actuarial tables for each patient were combined with these rates to estimate predicted MDs at end of expected lifetime. The proportion of patients projected to progress to visual impairment (MD: −14 dB or worse) or statutory blindness (MD: −22 dB or worse) in both eyes before end of expected lifetime was calculated. Results.: Only 3.0% (95% confidence interval [CI] 2.7%–3.4%) of patient eyes progressed at faster than −1.5 dB/year (n = 7149 eyes). Of those patients with both eyes followed, 5.2% (CI 4.5%–6.0%) were predicted to progress to statutory blindness, with a further 10.4% (CI 9.4%–11.4%) reaching visual impairment in their lifetime. More than 90% (CI 85.7%–94.3%) of patients predicted to progress to statutory blindness, had an MD worse than −6 dB in at least one eye at presentation. Conclusions.: This modeling exercise indicates that most patients in glaucoma clinics are not at high risk of progressing to statutory blindness. The likelihood of patients suffering impairment in their lifetimes is linked to VF loss at presentation, which illuminates the importance of reliably detecting significant VF defects in primary care

The Radio Afterglow and Host Galaxy of the Dark GRB 020819

Of the fourteen gamma-ray bursts (GRBs) localized to better than 2' radius with the SXC on HETE-2, only two lack optical afterglow detections, and the high recovery rate among this sample has been used to argue that the fraction of truly dark bursts is ~10%. While a large fraction of earlier dark bursts can be explained by the failure of ground-based searches to reach appropriate limiting magnitudes, suppression of the optical light of these SXC dark bursts seems likely. Here we report the discovery and observation of the radio afterglow of GRB 020819, an SXC dark burst, which enables us to identify the likely host galaxy (probability of 99.2%) and hence the redshift (z=0.41) of the GRB. The radio light curve is qualitatively similar to that of several other radio afterglows, and may include an early-time contribution from the emission of the reverse shock. The proposed host is a bright R = 19.5 mag barred spiral galaxy, with a faint R ~ 24.0 mag "blob'' of emission, 3" from the galaxy core (16 kpc in projection), that is coincident with the radio afterglow. Optical photometry of the galaxy and blob, beginning 3 hours after the burst and extending over more than 100 days, establishes strong upper limits to the optical brightness of any afterglow or associated supernova. Combining the afterglow radio fluxes and our earliest R-band limit, we find that the most likely afterglow model invokes a spherical expansion into a constant-density (rather than stellar wind-like) external environment; within the context of this model, a modest local extinction of A_V ~ 1 mag is sufficient to suppress the optical flux below our limits.Comment: 7 pages, 2 figures. ApJ, in press. For more info on dark bursts, see http://www.astro.ku.dk/~pallja/dark.htm