TIME SERIES ANALYSIS OF SATELLITE DATA: DEFORESTATION IN SOUTHERN MEXICO

Tropical deforestation is significant to a range of themes that have relevance for the study of environmental change and economic development, including global warming, land degradation, species extinction, and sustainability issues. Recognition that both the location and pattern of forest clearance are often as important as its magnitude has motivated an increasing number of econometric studies that link satellite data and government census data with the aim of modeling the spatial dimensions of deforestation processes. Initial research focused on time series analysis, while recent work has started developing models that make use of time series data on land use. In this paper, we use satellite data from three dates over an approximate 15-year period to estimate the probability of a satellite pixel being in a forested or human-disturbed state. Our study focuses on land-use change in an agricultural frontier spanning the southern Mexican states of Campeche and Quintana Roo. This region contains one of the largest and oldest expanses of tropical forests in the Americas outside of Amazonia and has been identified as a "hot spot" of forest and biotic diversity loss. Over the past 30 years, these forests have been under sustained pressure following the construction of a highway in 1972 that opened the frontier to settlement. The road was part of a larger development effort to promote agricultural colonization and has contributed to a prolonged period of land transformation that has been captured by Thematic Mapper (TM) satellite imagery. We capture these landscape dynamics by assembling a spatial database that links the pixels from three TM images spanning the years 1986-1997 and other spatial environmental and GIS-location derived data with government census socio-economic data of data. We develop a simple utility-maximizing model of the forest clearance decision. Based on previous research, the theoretical model suggests many possible determinants of forest clearance in an economic environment characterized by missing or thin markets, as typifies frontier regions in the nascent stages of economic development. We subsequently test the significance of these determinants using discrete choice analysis These modeling questions have particular relevance for informing carbon sequestration and global warming policy initiatives. Other on-going research conducted by the ecologists associated with the project focus on the species composition, abundance, structure, and re-growth of the different forests types in the region. In addition, litter and biomass studies have been completed which included carbon estimates for the different forest types, including forest re-growth on agricultural land, as function of fallow cycle dynamics. Fallow cycle dynamics are extremely important as the region is dominated by semi-subsistence agriculture with very little chemical inputs, so farmers depend on the fallow cycle to restore soil productivity. It will be these detailed data that will be used to calculate baseline carbon sequestration amounts.Resource /Energy Economics and Policy,

Conclusiones

En Paraguay, dada la experiencia actual, la política social particularmente la educativa y la de erradicación de la pobreza debe incorporar la perspectiva de género, que además del diseño tenga en cuenta también la implementación y evaluación. En las políticas macroeconómicas, la categoría género está totalmente ausente, por lo que el esfuerzo debe iniciarse en el diseño de las mismas. Las políticas comerciales, las reformas fiscales, el financiamiento del presupuesto público, la movilización de los recursos internacionales no han considerado las necesidades ni analizado su efecto diferenciado sobre las mujeres. Los desafíos para la investigación en Paraguay son innumerables, ya que no hay hasta el momento avances al respecto. Los trabajos siguientes deben profundizar el análisis del impacto de la liberalización en ramas productivas y sectores de mujeres particulares, ya que se observan diferencias importantes al respecto. Igualmente es necesario entender no sólo los efectos en el mercado laboral, en los ingresos o en el nivel de pobreza, sino también en la distribución del tiempo y de otros recursos al interior del hogar, por lo que el país debería contar con encuestas de uso del tiempo, actualmente inexistentes

A reversible water-based electrostatic adhesive

\ua9 2023 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH. Commercial adhesives typically fall into two categories: structural or pressure sensitive. Structural glues rely on covalent bonds formed during curing and provide high tensile strength whilst pressure-sensitive adhesives use physical bonding to provide weaker adhesion, but with considerable convenience for the user. Here, a new class of adhesive is presented that is also reversible, with a bond strength intermediate between those of pressure-sensitive and structural adhesives. Complementary water-based formulations incorporating oppositely charged polyelectrolytes form electrostatic bonds that may be reversed through immersion in a low or high pH aqueous environment. This electrostatic adhesive has the advantageous property that it exhibits good adhesion to low-energy surfaces such as polypropylene. Furthermore, it is produced by the emulsion copolymerization of commodity materials, styrene and butyl acrylate, which makes it inexpensive and opens the possibility of industrial production. Bio-based materials have been also integrated into the formulations to further increase sustainability. Moreover, unlike other water-based glues, adhesion does not significantly degrade in humid environments. Because such electrostatic adhesives do not require mechanical detachment, they are appropriate for the large-scale recycling of, e.g., bottle labels or food packaging. The adhesive is also suitable for dismantling components in areas as varied as automotive parts and electronics

Slow polymer diffusion on brush-patterned surfaces in aqueous solution

A model system for the investigation of diffusional transport in compartmentalized nanosystems is described. Arrays of “corrals” enclosed within poly[oligo(ethylene glycol)methyl ether methacrylate] (POEGMA) “walls” were fabricated using double-exposure interferometric lithography to deprotect aminosilane films protected by a nitrophenyl group. In exposed regions, removal of the nitrophenyl group enabled attachment of an initiator for the atom-transfer radical polymerization of end-grafted POEGMA (brushes). Diffusion coefficients for poly(ethylene glycol) in these corrals were obtained by fluorescence correlation spectroscopy. Two modes of surface diffusion were observed: one which is similar to diffusion on the unpatterned surface and a very slow mode of surface diffusion that becomes increasingly important as confinement increases. Diffusion within the POEGMA brushes does not significantly contribute to the results

High-force catch bonds between the <i>Staphylococcus aureus</i> surface protein SdrE and complement regulator factor H drive immune evasion

The invasive bacterial pathogen Staphylococcus aureus recruits the complement regulatory protein factor H (fH) to its surface to evade the human immune system. Here, we report the identification of an extremely high-force catch bond used by the S. aureus surface protein SdrE to efficiently capture fH under mechanical stress. We find that increasing the external force applied to the SdrE-fH complex prolongs the lifetime of the bond at an extraordinary high force, 1,400 pN, above which the bond lifetime decreases as an ordinary slip bond. This catch-bond behavior originates from a variation of the dock, lock and latch interaction, where the SdrE ligand binding domains undergo conformational changes under stress, enabling the formation of long-lived hydrogen bonds with fH. The binding mechanism dissected here represents a potential target for new therapeutics against multidrug-resistant S. aureus strains. © 2023, The Author(s)

Perturbed cholesterol and vesicular trafficking associated with dengue blocking in Wolbachia-infected Aedes aegypti cells

Wolbachia are intracellular maternally inherited bacteria that can spread through insect populations and block virus transmission by mosquitoes, providing an important approach to dengue control. To better understand the mechanisms of virus inhibition, we here perform proteomic quantification of the effects of Wolbachia in Aedes aegypti mosquito cells and midgut. Perturbations are observed in vesicular trafficking, lipid metabolism and in the endoplasmic reticulum that could impact viral entry and replication. Wolbachia-infected cells display a differential cholesterol profile, including elevated levels of esterified cholesterol, that is consistent with perturbed intracellular cholesterol trafficking. Cyclodextrins have been shown to reverse lipid accumulation defects in cells with disrupted cholesterol homeostasis. Treatment of Wolbachia-infected Ae. aegypti cells with 2-hydroxypropyl-β-cyclodextrin restores dengue replication in Wolbachia-carrying cells, suggesting dengue is inhibited in Wolbachia-infected cells by localised cholesterol accumulation. These results demonstrate parallels between the cellular Wolbachia viral inhibition phenotype and lipid storage genetic disorders

The universal functorial equivariant Lefschetz invariant

We introduce the universal functorial equivariant Lefschetz invariant for endomorphisms of finite proper G-CW-complexes, where G is a discrete group. We use K_0 of the category of "phi-endomorphisms of finitely generated free RPi(G,X)-modules". We derive results about fixed points of equivariant endomorphisms of cocompact proper smooth G-manifolds.Comment: 33 pages; shortened version of the author's PhD thesis, supervised by Wolfgang Lueck, Westfaelische Wilhelms-Universitaet Muenster, 200