Saving Sea Turtles : Examining the Efficacy of American Conservation Efforts in Mexico

“Saving Sea Turtles”: Examining the Efficacy of American Conservation Efforts in Mexico This paper explores how cultural differences can disorient American marine turtle conservationists and impede enduring resolutions. All six of Mexico’s marine turtle species are in danger of extinction, largely due to anthropogenic habitat destruction and egg poaching. While many American conservancies have had success in relocating nests and releasing hatchlings, these efforts address symptoms rather than core concerns. Told partially through narrative of experiences working with El Grupo Ecologico in Nayarit, this paper expounds upon interactions with poachers, who are also police officers, fishermen, and parents, to build a greater framework of understanding. Villainizing poachers often blinds conservationists from comprehending the moral calculus of what leads an individual to poach. Interviews with locals identified the cultural significance of turtle eggs, economic disparity, police corruption, and failing fisheries as incentives for poaching. Further discussion of relevant literature supports these findings, and reveals why international and Mexican domestic policies have failed in application. The goal of this paper is to identify barriers that prevent conservancy-based ecosystem monitoring from becoming community-based ecosystem motoring. Recognizing ideological, linguistic, and cultural barriers is critical to building relationships with a community. The clash between El Grupo Ecologico and poachers is a specific example of polarized ideologies, but its struggles are mirrored across Mexico and Latin America. American institutions can never hope to solve these deeper political and socioeconomic issues: for those who grow up in privilege cannot wholly comprehend the complex dynamics of the developing world. However, they can foster a new generation of conservationists, empowering people and learning from them in turn. The recognition of difference is critical to setting realistic goals. Understanding the extent to which American conservancies can benefit communities, and when to instead enable a community to benefit itself, is the only way in which sustainable turtle conservation can be achieved

An Illustrated Geography

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Reconstruction of cloud geometry using a scanning cloud radar

Clouds are one of the main reasons of uncertainties in the forecasts of weather and climate. In part, this is due to limitations of remote sensing of cloud microphysics. Present approaches often use passive spectral measurements for the remote sensing of cloud microphysical parameters. Large uncertainties are introduced by three-dimensional (3-D) radiative transfer effects and cloud inhomogeneities. Such effects are largely caused by unknown orientation of cloud sides or by shadowed areas on the cloud. Passive ground-based remote sensing of cloud properties at high spatial resolution could be crucially improved with this kind of additional knowledge of cloud geometry. To this end, a method for the accurate reconstruction of 3-D cloud geometry from cloud radar measurements is developed in this work. Using a radar simulator and simulated passive measurements of model clouds based on a large eddy simulation (LES),the effects of different radar scan resolutions and varying interpolation methods are evaluated. In reality, a trade-off between scan resolution and scan duration has to be found as clouds change quickly. A reasonable choice is a scan resolution of 1 to 2\degree. The most suitable interpolation procedure identified is the barycentric interpolation method. The 3-D reconstruction method is demonstrated using radar scans of convective cloud cases with the Munich miraMACS, a 35 GHz scanning cloud radar. As a successful proof of concept, camera imagery collected at the radar location is reproduced for the observed cloud cases via 3-D volume reconstruction and 3-D radiative transfer simulation. Data sets provided by the presented reconstruction method will aid passive spectral ground-based measurements of cloud sides to retrieve microphysical parameters

The correlation between ovule quality parameters and the seed yield at Cyclamen persicum MILL.

Are there indicators that the seed yield at Cyclamen persicum is predetermined by the quality of ovules? This was the main question of these investigations.The aim of our study was to investigate why only some of the available ovules develop into mature seeds. We surmised that the quality of the ovules played an important role in this. In order to corroborate this theory, we examined specific ovule parameters and their correlation with seed yield.The parameters included the levels of callose in the nucellus, the heterogeneity of embryo sacs, the deviants in callose inclusion and the number of ovules examined by light and fluorescence microscopy.There is still considerable disagreement on the biological significance of the inclusion of callose in ovules. In our study, we were able to show that the inclusion of callose is essential for fertilization in the case of C. persicum. This appears to contradict the findings reported for other plant species, where the inclusion of callose has been evaluated as a sign of ovule degeneration. However, the results of our study clearly demonstrate that seed yield is already determined by the maternal plant during the ovule development phase, i. e. shortly before and at the beginning of anthesis.Some ovule parameters allow predictions to be made about the expected seed yield for the studied genotypes of C. persicum

Reconstruction of cloud geometry using a scanning cloud radar

Clouds are one of the main reasons of uncertainties in the forecasts of weather and climate. In part, this is due to limitations of remote sensing of cloud microphysics. Present approaches often use passive spectral measurements for the remote sensing of cloud microphysical parameters. Large uncertainties are introduced by three-dimensional (3-D) radiative transfer effects and cloud inhomogeneities. Such effects are largely caused by unknown orientation of cloud sides or by shadowed areas on the cloud. Passive ground-based remote sensing of cloud properties at high spatial resolution could be crucially improved with this kind of additional knowledge of cloud geometry. To this end, a method for the accurate reconstruction of 3-D cloud geometry from cloud radar measurements is developed in this work. Using a radar simulator and simulated passive measurements of model clouds based on a large eddy simulation (LES),the effects of different radar scan resolutions and varying interpolation methods are evaluated. In reality, a trade-off between scan resolution and scan duration has to be found as clouds change quickly. A reasonable choice is a scan resolution of 1 to 2\degree. The most suitable interpolation procedure identified is the barycentric interpolation method. The 3-D reconstruction method is demonstrated using radar scans of convective cloud cases with the Munich miraMACS, a 35 GHz scanning cloud radar. As a successful proof of concept, camera imagery collected at the radar location is reproduced for the observed cloud cases via 3-D volume reconstruction and 3-D radiative transfer simulation. Data sets provided by the presented reconstruction method will aid passive spectral ground-based measurements of cloud sides to retrieve microphysical parameters

Evolutionary bi-stability in pathogen transmission mode

Many pathogens transmit to new hosts by both infection (horizontal transmission) and transfer to the infected host's offspring (vertical transmission). These two transmission modes require speci®c adap- tations of the pathogen that can be mutually exclusive, resulting in a trade-off between horizontal and vertical transmission. We show that in mathematical models such trade-offs can lead to the simultaneous existence of two evolutionary stable states (evolutionary bi-stability) of allocation of resources to the two modes of transmission. We also show that jumping between evolutionary stable states can be induced by gradual environmental changes. Using quantitative PCR-based estimates of abundance in seed and vege- tative parts, we show that the pathogen of wheat, Phaeosphaeria nodorum, has jumped between two distinct states of transmission mode twice in the past 160 years, which, based on published evidence, we interpret as adaptation to environmental change. The ®nding of evolutionary bi-stability has impli- cations for human, animal and other plant diseases. An ill-judged change in a disease control programme could cause the pathogen to evolve a new, and possibly more damaging, combination of transmission modes. Similarly, environmental changes can shift the balance between transmission modes, with adverse effects on human, animal and plant health

Remote sensing of cloud droplet radius profiles using solar reflectance from cloud sides – Part 1: Retrieval development and characterization

Convective clouds play an essential role for Earth's climate as well as for regional weather events since they have a large influence on the radiation budget and the water cycle. In particular, cloud albedo and the formation of precipitation are influenced by aerosol particles within clouds. In order to improve the understanding of processes from aerosol activation, from cloud droplet growth to changes in cloud radiative properties, remote sensing techniques become more and more important. While passive retrievals for spaceborne observations have become sophisticated and commonplace for inferring cloud optical thickness and droplet size from cloud tops, profiles of droplet size have remained largely uncharted territory for passive remote sensing. In principle they could be derived from observations of cloud sides, but faced with the small-scale heterogeneity of cloud sides, “classical” passive remote sensing techniques are rendered inappropriate. In this work the feasibility is demonstrated to gain new insights into the vertical evolution of cloud droplet effective radius by using reflected solar radiation from cloud sides. Central aspect of this work on its path to a working cloud side retrieval is the analysis of the impact unknown cloud surface geometry has on effective radius retrievals. This study examines the sensitivity of reflected solar radiation to cloud droplet size, using extensive 3-D radiative transfer calculations on the basis of realistic droplet size resolving cloud simulations. Furthermore, it explores a further technique to resolve ambiguities caused by illumination and cloud geometry by considering the surroundings of each pixel. Based on these findings, a statistical approach is used to provide an effective radius retrieval. This statistical effective radius retrieval is focused on the liquid part of convective water clouds, e.g., cumulus mediocris, cumulus congestus, and trade-wind cumulus, which exhibit well-developed cloud sides. Finally, the developed retrieval is tested using known and unknown cloud side scenes to analyze its performance.</p

Boundary conditions for interfaces of electromagnetic (photonic) crystals and generalized Ewald-Oseen extinction principle

The problem of plane-wave diffraction on semi-infinite orthorhombic electromagnetic (photonic) crystals of general kind is considered. Boundary conditions are obtained in the form of infinite system of equations relating amplitudes of incident wave, eigenmodes excited in the crystal and scattered spatial harmonics. Generalized Ewald-Oseen extinction principle is formulated on the base of deduced boundary conditions. The knowledge of properties of infinite crystal's eigenmodes provides option to solve the diffraction problem for the corresponding semi-infinite crystal numerically. In the case when the crystal is formed by small inclusions which can be treated as point dipolar scatterers with fixed direction the problem admits complete rigorous analytical solution. The amplitudes of excited modes and scattered spatial harmonics are expressed in terms of the wave vectors of the infinite crystal by closed-form analytical formulae. The result is applied for study of reflection properties of metamaterial formed by cubic lattice of split-ring resonators.Comment: 15 pages, 8 figures, submitted to PR