245 research outputs found
Statutory Reform to Protect Migrations as Phenomena of Abundance
Animal migrations capture the human mind and heart like few other natural phenomena. Migrations provide ecological, psychological (e.g., aesthetic), cultural, and economic benefits. Increasingly, though, migrations are being recognized as threatened phenomena-that is, spectacular aspects of the life history of animal species often involving large numbers of individuals, but which are threatened with impoverishment or demise, even though the species per se may not be in peril. Migration phenomena are themselves worthy of protection, as a category of biodiversity Yet, conserving migratory populations and their migrations is particularly problematic. Migratory animals are especially vulnerable to a variety of threats because they come into contact with multiple ecosystems and jurisdictions, tend to congregate in large numbers in discrete and often vulnerable areas, and require considerable fuel for their long-distance journeys. In addition, migration is essentially a phenomenon of abundance-the benefits and values of migrations depend on an abundance of animals taking part and conserving species\u27 populations before they become rare has always been an uphill battle. This Article presents an idea for a new federal law that reflects the perspective that conserving migratory behaviors and processes as phenomena of value in and of themselves, and not only of value for species persistence, can provide unique and important benefits. Current conservation laws generally serve the species-based conservation perspective and, with a few exceptions, are not designed or implemented to protect benefits of abundant animal migrations. The existing fragmented framework of laws and authorities also is insufficient to protect most migratory populations against a diversity of threats across multiple jurisdictions and broad geographic scales. Our proposed federal law would offer a unified framework, require abundance targets, and authorize a comprehensive set of legal tools, including both carrots and sticks, for conserving a limited set of nationally or regionally significant migrations. Such a law would likely improve the current situation for the nation\u27s most notable migratory populations and generally promote the conservation of all migrations as phenomena of abundance
Statutory Reform to Protect Migrations as Phenomena of Abundance
Animal migrations capture the human mind and heart like few other natural phenomena. Migrations provide ecological, psychological (e.g., aesthetic), cultural, and economic benefits. Increasingly, though, migrations are being recognized as threatened phenomena-that is, spectacular aspects of the life history of animal species often involving large numbers of individuals, but which are threatened with impoverishment or demise, even though the species per se may not be in peril. Migration phenomena are themselves worthy of protection, as a category of biodiversity Yet, conserving migratory populations and their migrations is particularly problematic. Migratory animals are especially vulnerable to a variety of threats because they come into contact with multiple ecosystems and jurisdictions, tend to congregate in large numbers in discrete and often vulnerable areas, and require considerable fuel for their long-distance journeys. In addition, migration is essentially a phenomenon of abundance-the benefits and values of migrations depend on an abundance of animals taking part and conserving species\u27 populations before they become rare has always been an uphill battle. This Article presents an idea for a new federal law that reflects the perspective that conserving migratory behaviors and processes as phenomena of value in and of themselves, and not only of value for species persistence, can provide unique and important benefits. Current conservation laws generally serve the species-based conservation perspective and, with a few exceptions, are not designed or implemented to protect benefits of abundant animal migrations. The existing fragmented framework of laws and authorities also is insufficient to protect most migratory populations against a diversity of threats across multiple jurisdictions and broad geographic scales. Our proposed federal law would offer a unified framework, require abundance targets, and authorize a comprehensive set of legal tools, including both carrots and sticks, for conserving a limited set of nationally or regionally significant migrations. Such a law would likely improve the current situation for the nation\u27s most notable migratory populations and generally promote the conservation of all migrations as phenomena of abundance
Release of Ciprofloxacin-HCl and Dexamethasone Phosphate by Hyaluronic Acid Containing Silicone Polymers
Nguyen, D., Hui, A., Weeks, A., Heynen, M., Joyce, E., Sheardown, H., & Jones, L. (2012). Release of Ciprofloxacin-HCl and Dexamethasone Phosphate by Hyaluronic Acid Containing Silicone Polymers. Materials, 5(12), 684–698. https://doi.org/10.3390/ma5040684The purpose of this study was to determine the effect of the covalent incorporation of hyaluronic acid (HA) into conventional hydrogel and hydrogels containing silicone as models for contact lens materials on the uptake and release of the fluoroquinolone antibiotic ciprofloxacin and the anti-inflammatory steroid dexamethasone phosphate. A 3 mg/mL ciprofloxacin solution (0.3% w/v) and a 1 mg/mL dexamethasone phosphate solution (0.1%) was prepared in borate buffered saline. Three hydrogel material samples (pHEMA; pHEMA TRIS; DMAA TRIS) were prepared with and without the covalent incorporation of HA of molecular weight (MW) 35 or 132 kDa. Hydrogel discs were punched from a sheet of material with a uniform diameter of 5 mm. Uptake kinetics were evaluated at room temperature by soaking the discs for 24 h. Release kinetics were evaluated by placing the drug-loaded discs in saline at 34 °C in a shaking water bath. At various time points over 6–7 days, aliquots of the release medium were assayed for drug amounts. The majority of the materials tested released sufficient drug to be clinically relevant in an ophthalmic application, reaching desired concentrations for antibiotic or anti-inflammatory activity in solution. Overall, the silicone-based hydrogels (pHEMA TRIS and DMAA TRIS), released lower amounts of drug than the conventional pHEMA material (p < 0.001). Materials with HA MW132 released more ciprofloxacin compared to materials with HA MW35 and lenses without HA (p < 0.02). Some HA-based materials were still releasing the drug after 6 days.This study is supported by the Natural Sciences and Engineering Research Council (NSERC) 20/20 Network for the Development of Advanced Ophthalmic Materials. AH is supported by NSERC Canada, the Canadian Optometric Education Trust Fund (COETF), and a Vistakon® Research Grant and Ezell Fellowship, both administered by the American Optometric Foundation (AOF)
To move or to evolve: contrasting patterns of intercontinental connectivity and climatic niche evolution in “Terebinthaceae” (Anacardiaceae and Burseraceae)
Many angiosperm families are distributed pantropically, yet for any given continent little is known about which lineages are ancient residents or recent arrivals. Here we use a comprehensive sampling of the pantropical sister pair Anacardiaceae and Burseraceae to assess the relative importance of continental vicariance, long-distance dispersal and niche-conservatism in generating its distinctive pattern of diversity over time. Each family has approximately the same number of species and identical stem age, yet Anacardiaceae display a broader range of fruit morphologies and dispersal strategies and include species that can withstand freezing temperatures, whereas Burseraceae do not. We found that nuclear and chloroplast data yielded a highly supported phylogenetic reconstruction that supports current taxonomic concepts and time-calibrated biogeographic reconstructions that are broadly congruent with the fossil record. We conclude that the most recent common ancestor of these families was widespread and likely distributed in the Northern Hemisphere during the Cretaceous and that vicariance between Eastern and Western Hemispheres coincided with the initial divergence of the families. The tempo of diversification of the families is strikingly different. Anacardiaceae steadily accumulated lineages starting in the Late Cretaceous–Paleocene while the majority of Burseraceae diversification occurred in the Miocene. Multiple dispersal- and vicariance-based intercontinental colonization events are inferred for both families throughout the past 100 million years. However, Anacardiaceae have shifted climatic niches frequently during this time, while Burseraceae have experienced very few shifts between dry and wet climates and only in the tropics. Thus, we conclude that both Anacardiaceae and Burseraceae move easily but that Anacardiaceae have adapted more often, either due to more varied selective pressures or greater intrinsic lability
Inclusive and anti-racist collecting at UNLV libraries.
Summary of inclusive and anti-racist collecting at UNLV libraries
Commiphora omundomba (Burseraceae), a new species from Angola and Namibia
Commiphora omundomba, described here as a new species, is known only from the Kaokoveld Centre of Endemism, a
biogeographical region in southwestern Angola and Northwestern Namibia. It has hitherto been confused with C. dinteri
from west-central Namibia, but both morphological and molecular evidence support a distinction between the two species.
Phylogenetic analysis of DNA sequence data indicates that C. omundomba shares most-recent common ancestry with C.
buruxa, a species limited to the Gariep Centre of Endemism in southwestern Namibia. Diagnostic morphological characters
for C. omundomba include the white, viscous exudate, smooth bark and glabrous, trifoliolate leaves. Photographs of the plant
and a distribution map are provided. The new species is mainly confined to near the Atlantic coast of the northern Namib
Desert, and is widespread and locally common between Santa Maria in Angola and Puros in Namibia.https://www.mapress.com/ptdm2022Plant Production and Soil Scienc
A Soluble Phase Field Model
The kinetics of an initially undercooled solid-liquid melt is studied by
means of a generalized Phase Field model, which describes the dynamics of an
ordering non-conserved field phi (e.g. solid-liquid order parameter) coupled to
a conserved field (e.g. thermal field). After obtaining the rules governing the
evolution process, by means of analytical arguments, we present a discussion of
the asymptotic time-dependent solutions. The full solutions of the exact
self-consistent equations for the model are also obtained and compared with
computer simulation results. In addition, in order to check the validity of the
present model we confronted its predictions against those of the standard Phase
field model and found reasonable agreement. Interestingly, we find that the
system relaxes towards a mixed phase, depending on the average value of the
conserved field, i.e. on the initial condition. Such a phase is characterized
by large fluctuations of the phi field.Comment: 13 pages, 8 figures, RevTeX 3.1, submitted to Physical Review
Rigorous Inequalities between Length and Time Scales in Glassy Systems
Glassy systems are characterized by an extremely sluggish dynamics without
any simple sign of long range order. It is a debated question whether a correct
description of such phenomenon requires the emergence of a large correlation
length. We prove rigorous bounds between length and time scales implying the
growth of a properly defined length when the relaxation time increases. Our
results are valid in a rather general setting, which covers finite-dimensional
and mean field systems.
As an illustration, we discuss the Glauber (heat bath) dynamics of p-spin
glass models on random regular graphs. We present the first proof that a model
of this type undergoes a purely dynamical phase transition not accompanied by
any thermodynamic singularity.Comment: 24 pages, 3 figures; published versio
The litmus test of pride: analysing the emergence of the Belgrade “Ghost” pride in the context of EU accession
The transformation of lesbian, gay, bisexual, and transgender (LGBT) rights into a “standard for civilisation” has not been without consequences. With LGBT Pride parades becoming a symbol for Europeanness in the European Union (EU) accession process, this article asks how the litmus test character of Belgrade Pride has transformed LGBT politics in Serbia. Empirically, the analysis provides an in-depth analysis of how Serbia’s EU accession process has shaped the politics of Belgrade Pride between 2001 and 2015 and vice versa. It is argued that the international symbolic usage of Pride is no innocent practice as it has foreclosed its local politicality. Indeed, whilst Belgrade Pride became politicised as a litmus test in the EU accession process, domestically it developed into an apolitical ritualised event devoid of LGBT politics
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