LONG-TERM CHANGES IN CANADA GOOSE NEST SUCCESS AND NEST DENSITIES AT AN IOWA WETLAND COMPLEX

Giant Canada geese (Branta canadensis maxima) were extirpated from Iowa by the early 1900s due to unregulated hunting, egg gathering, and wetland drainage in the nineteenth century (Bishop 1978). Ef- forts to reintroduce Canada geese in Iowa began in 1964 (Bishop and Howing 1972) and involved releasing flightless adults and goslings at nearly 30 sites across the state (Zenner and LaGrange 1998a). In 1972, 13 flightless pairs were released at Rice Lake Wildlife Management Area (WMA; Bishop 1978). By 1989, the breeding population of Canada geese at Rice Lake WMA had increased to 420 nesting adults (G. G. Zenner, Iowa Department of Natural Resources, unpublished data). Canada goose nest success and nest densities were documented from 1989–1991 on extant islands at Rice Lake WMA (Zenner and LaGrange 1998b). Rice Lake WMA (43.379497, –93.472715) is located in north-central Iowa and lies within the southernmost portion of the Prairie Pothole Region. This wetland complex consists of Rice Lake, a 409-ha shallow, natural lake with a maximum depth of 3 m and 20 natural islands ranging in size from 0.04 to 3.9 ha, and Joice Slough, a 73-ha marsh with a maximum depth of 1 m and 15 natural islands ranging in size from 0.02 to 3.19 ha (Zenner and LaGrange 1998b). During 1989–1991, potential Canada goose nest sites included islands, elevated structures, and muskrat houses. Over the course of that study, drought conditions left Joice Slough completely dry and dramatically lowered water levels at Rice Lake, exposing islands to increased predator activity. Despite the drought, nest densities were high (68–158 nests/ha) and nest success ranged from 40–58% (Zenner and LaGrange 1998b)

Quasi-topological Reissner-Nordstr\"om Black Holes

We consider Reissner-Nordstrom solutions in quasi-topological gravity, obtaining exact solutions to the field equations yielding charged quasi-topological black holes. We study their thermodynamic behaviour over a range of parameters that yield ghost-free and stable space times. We find that a sufficiently negative quasi-topological parameter can yield black holes with 2 horizons, even for zero charge. We discuss the thermodynamic stability for the class of solutions we obtain. We also describe the structure of exact charged solutions to $k^{th}$ order quasi-topological gravity.Comment: LaTeX, 16 pages, 9 figures; added references and corrected typo

Multienzymatic Stereoselective Reduction of Tetrasubstituted Cyclic Enones to Halohydrins with Three Contiguous Stereogenic Centers

The asymmetric hydrogenation of conjugated tetrasubstituted alkenes with transition-metal catalysts is a challenging reaction, especially for substrates bearing a halide substituent. We describe a two-step multienzymatic reduction of a series of α-halo β-alkyl tetrasubstituted cyclic enones, affording halohydrins with three contiguous stereogenic centers, in good yield and with a high stereoselectivity. The reduction is catalyzed by a stereospecific ene-reductase (OYE2-3 or NemA) and a highly enantioselective alcohol dehydrogenase (ADH). The use of two enantiodivergent ADHs allows the control of the diastereoselectivity. The absolute stereochemical configurations of the products have been determined from the analysis of single-crystal structures (Flack's parameter). The enantiomeric excess (ee) has been determined by derivatization of the products with (R) Mosher's acid. Lastly, we extended our methodology also to a nonhalogenated substrate: the α-methyl ketoisophorone was reduced by two distinct enantiodivergent ene-reductases (flavin mononucleotide- and F 420-dependent), affording each enantiomer of the saturated ketone with ee > 98%

Facilitating Constructive Discussions of Difficult Socio-Scientific Issues

Discussion can be an important and powerful tool in efforts to build a more diverse, equitable, and inclusive future for STEM (i.e., science, technology, engineering, and mathematics). However, facilitating discussions on difficult, complex, and often uncomfortable issues, like racism and sexism, can feel daunting. We outline a series of steps that can be used by educators to facilitate productive discussions that empower everyone to listen, contribute, learn, and ultimately act to transform STEM

Black holes and black branes in Lifshitz spacetimes

We construct analytic solutions describing black holes and black branes in asymptotically Lifshitz spacetimes with arbitrary dynamical exponent z and for arbitrary number of dimensions. The model considered consists of Einstein gravity with negative cosmological constant, a scalar, and N U(1) gauge fields with dilatonic-like couplings. We study the phase diagrams and thermodynamic instabilities of the solution, and find qualitative differences between the cases with 12.Comment: 27 pages, 10 figures; v2 references added, minor comments adde

The Cognitive Change Index as a Measure of Self and Informant Perception of Cognitive Decline: Relation to Neuropsychological Tests

BACKGROUND: The perception of cognitive decline by individuals and those who know them well ("informants") has been inconsistently associated with objective cognitive performance, but strongly associated with depressive symptoms. OBJECTIVE: We investigated associations of self-report, informant-report, and discrepancy between self- and informant-report of cognitive decline obtained from the Cognitive Change Index (CCI) with cognitive test performance and self-reported depressive symptoms. METHODS: 267 participants with normal cognition, mild cognitive impairment (MCI), or mild dementia were included from a cohort study and memory clinic. Association of test performance and self-rated depression (Geriatric Depression Scale, GDS) with CCI scores obtained from subjects (CCI-S), their informants (CCI-I), and discrepancy scores between subjects and informants (CCI-D; CCI-S minus CCI-I) were analyzed using correlation and analysis of covariance (ANCOVA) models. RESULTS: CCI-S and CCI-I scores showed high internal consistency (Cronbach alpha 0.96 and 0.98, respectively). Higher scores on CCI-S and CCI-I, and lower scores on the CCI-D, were associated with lower performance on various cognitive tests in both univariate and in ANCOVA models adjusted for age, gender, and education. Adjustment for GDS slightly weakened the relationships between CCI and test performance but most remained significant. CONCLUSION: Self- and informant-report of cognitive decline, as measured by the CCI, show moderately strong relationships with objective test performance independent of age, gender, education, and depressive symptoms. The CCI appears to be a valid cross-sectional measure of self and informant perception of cognitive decline across the continuum of functioning. Studies are needed to address the relationship of CCI scores to longitudinal outcome

Spatially homogeneous Lifshitz black holes in five dimensional higher derivative gravity

We consider spatially homogeneous Lifshitz black hole solutions in five dimensional higher derivative gravity theories, which can be possible near horizon geometries of some systems that are interesting in the framework of gauge/gravity duality. We show the solutions belonging to the nine Bianchi classes in the pure R^2 gravity. We find that these black holes have zero entropy at non-zero temperatures and this property is the same as the case of BTZ black holes in new massive gravity at the critical point. In the most general quadratic curvature gravity theories, we find new solutions in Bianchi Type I and Type IX cases.Comment: 15 pages, no figure; v2, refs added, version to appear in JHE

Field theories with anisotropic scaling in 2D, solitons and the microscopic entropy of asymptotically Lifshitz black holes

Field theories with anisotropic scaling in 1+1 dimensions are considered. It is shown that the isomorphism between Lifshitz algebras with dynamical exponents z and 1/z naturally leads to a duality between low and high temperature regimes. Assuming the existence of gap in the spectrum, this duality allows to obtain a precise formula for the asymptotic growth of the number of states with a fixed energy which depends on z and the energy of the ground state, and reduces to the Cardy formula for z=1. The holographic realization of the duality can be naturally inferred from the fact that Euclidean Lifshitz spaces in three dimensions with dynamical exponents and characteristic lengths given by z, l, and 1/z, l/z, respectively, are diffeomorphic. The semiclassical entropy of black holes with Lifshitz asymptotics can then be recovered from the generalization of Cardy formula, where the ground state corresponds to a soliton. An explicit example is provided by the existence of a purely gravitational soliton solution for BHT massive gravity, which precisely has the required energy that reproduces the entropy of the analytic asymptotically Lifshitz black hole with z=3. Remarkably, neither the asymptotic symmetries nor central charges were explicitly used in order to obtain these results.Comment: 17 pages, no figures, references corrected and update