Rhegmatogenous retinal detachment masquerading as exudative panuveitis with intense anterior chamber inflammatory reaction.

Purpose:This is a retrospective case report illustrating the diagnostic and therapeutic challenges associated with a chronic rhegmatogenous retinal detachment masquerading as a severe panuveitis with intense anterior chamber inflammation. We have included clinical features, anterior segment and fundus photography, B-scan ultrasonography, fluorescein angiography, and intraoperative findings. Observations:A 26-year-old male presented with features of unilateral panuveitis: hypotony, anterior segment inflammation (posterior synechiae and anterior chamber cell with fibrin clumping), diffuse choroidal thickening, and retinal detachment. Laboratory investigations for infectious or rheumatologic processes were negative, and empiric systemic corticosteroid therapy was unsuccessful. This prompted suspicion for an alternate primary etiology, and pars plana vitrectomy revealed small retinal breaks as the underlying cause of the retinal detachment and inflammation. Conclusions:Rhegmatogenous retinal detachments are a known cause of intraocular inflammation. Nevertheless, it remains a challenge to recognize retinal breaks in this setting, particularly with robust anterior segment inflammation and posterior findings resembling severe exudative uveitis. Being aware of this unique presentation may prevent delays in diagnosis and have important prognostic implications

Analysis of selected policy alternatives in the agricultural sector of the Philippines

The primary objective of this study was to estimate and evaluate the economic effects of selected policy alternatives on prices, output, employment and income in the agricultural sector of the Philippines. The policies evaluated were: fertilizer subsidy; efficiency of irrigation systems; rice price ceilings; mechanization; and natural calamities. The study used a national production-processing-distribution programming model (MAAGAP) and had the following assumptions: a given set of national demands for agricultural commodities; a set of national supplies of resources; and a set of production technologies. Given these sets of conditions and with the further assumption that Philippine agriculture approximated a perfectly competitive market, the MAAGAP model\u27s objective function was the maximization of the sum of the producer\u27s and consumer\u27s surplus (net social benefit). The model isolated the agricultural sector and equated aggregate supply with derived aggregate demand under a linear programming static framework. This procedure would endogenously determine equilibrium prices and quantities at the sectoral level. The input-output (I/O) coefficients for crops used by this study were taken from the national cost of production survey conducted by the Bureau of Agricultural Economics (BAEcon) in 1972; the farm management surveys made by the University of the Philippines College of Agriculture (UPCA); and the Philippine Sugar Institute (PHILSUGIN). For the input-output coefficients on livestock, the primary sources were the studies made by the Development Bank of the Philippines (DBF); the UPCA; and other specialized studies made by Gapuz (poultry) and Drilon (piggery). The demand estimates on the other hand came from two basic studies: the Foote\u27s econometric model based on a time series, fitted by three-stage least squares (3 SLS) and the regression analysis made by Ferrer based on a crossed section data from a consumption survey conducted by Dosayla and Darrah. Results from the study showed that removing the fertilizer subsidy to the food crop subsector would lead to a lower production of rice, lower employment, a decline in usage of tractor services, a decline in capital usage and a lower marginal productivity of land because of lower fertilizer consumption in the food crop subsector. Consumer\u27s surplus would likewise decline while producer\u27s surplus would increase as the fertilizer subsidy to the food crop subsector would be removed. A uniform fertilizer subsidy for both subsectors at high levels (100 to 72 percent subsidy) would result into a significant decrease in domestic prices compared to their 1974 base levels (which was 53 percent subsidized only for the food crop subsector); higher employment; and increase in capital usage as compared to the 1974 base. Higher uniform subsidy levels for both subsectors, however, would tend to reduce the use of four-wheel tractor services and animal labor as compared to the 1974 base. At low levels of uniform subsidy for both export and food crops, domestic production would decline and prices of commodities would tend to rise. Employment, four-wheel tractor usage and animal services would also decline. The Imposition of a 4 percent tax on the export subsector would adversely affect the levels of exports. A uniform fertilizer subsidy scheme whether a tax is imposed or not would generally result in higher net social benefits for both consumers and producers, with the proportion of shares differing between the two conditions (generally lower benefits when tax is imposed). Increasing the efficiency of the irrigation systems would result in higher production of rice, increase in employment, higher usage of capital by crops, increase in fertilizer usage (especially palay), a higher net social benefit for the agricultural sector with consumers benefiting from relatively lower prices. Results of the study also showed that a rice price ceiling of ₱843 per metric ton (?₱1.90 per kilogram at 1974 current prices) would result to lower rice production relative to the 1974 base when no price ceiling was in effect. Furthermore, to maintain the rice price ceiling at ₱1.90 per kilogram, the estimates indicate that .9371 thousand metric tons of rice must be imported, incurring an approximate import subsidy cost of ₱2.8 million. Low price ceilings would tend to depress domestic production, and producer\u27s surplus would be relatively lower while consumer\u27s surplus would be somewhat higher. Higher rice price ceilings on the other hand would eliminate rice import subsidy costs and producer\u27s surplus would be greater while consumer\u27s surplus would be less. The simultaneous increase in the availability of both hand and four-wheel tractor services (0 to 200 percent of 1972 levels) would result in increases in the production of rice and sugar but decreases in the production of corn and commercial hogs. Results in the variation of tractor services also demonstrated the substitutability of both man labor and animal labor for tractor services, while fertilizer showed a comple-mentary relationship with tractor services. Variations in the availability of hand tractor services with four-wheel tractors held constant at 1972 levels, showed the decline in palay production below 1972 base levels but would be offset more than propor-tionately by the substitution of corn grain production for palay. Increasing hand tractor services above the 1972 base levels on the other hand would lead to the higher production of palay but a probable displacement of man and animal labor in the production of rice and corn. Results also indicated that four-wheel tractor services were very vital in the production of sugar and palay but not corn. Reducing the availability of four-wheel tractor services below the 1972 levels would reduce the production of sugar and rice. Results from parametric variation of four-wheel tractors showed that fertilizer was complementary input to four-wheel tractor while animal and man labor services were competing inputs to four—wheel tractor usage. The net effects of floods and/or natural calamities would be higher agricultural prices and lower net social benefits. Finally, the study also evaluated the different policies relative to target variables such as net social benefit for the agricultural sector, value of production, usage levels of inputs, trade, government budget and prices. Results showed that there was no one policy mix that would provide a perfect economic alternative to all relevant macroeconomic variables. Well defined trade-offs were evident among the different policies. For example, producer\u27s surplus and consumer’s surplus were almost always in conflict. In the two exceptions (higher uniform fertilizer subsidy and rice price ceiling of ₱1.143 per metric ton) both may be increased at the expense of a decline in animal labor services, tractor services and export levels

Modeling the spatial and temporal trends of water quality in boreal managed watersheds

Land use changes have altered natural hydrological pathways and biogeochemical cycling of carbon, nitrogen and phosphorus, among other elements, affecting the quality of aquatic ecosystems such as rivers, lakes and coastal areas. In this dissertation, the spatial and temporal trends of water quality variation in Finnish managed watersheds was studied by applying methods of multivariate statistics, time-series analysis, ecohydrological modeling and high-resolution geospatial data. The results show the complex effects of current land use, particularly agriculture, on stream water quality. New emerging trends of nutrient concentrations and loads were detected in the time-series analysis, such as an increase in the concentrations and loads of dissolved reactive phosphorus and total nitrogen, and a decrease in suspended sediment concentration in streams. This might be linked to the current erosion reduction strategy of land management for water protection. An ecohydrological modeling assessment showed an increasing downstream nutrient export from agricultural watershed under climate change scenarios. The modeling results also showed a potential nutrient export reduction by restoring potential biogeochemical hotspot areas - wet areas or areas prone to water saturation. These areas can function as nutrient sinks and enhance the watershed resiliency. High-resolution geospatial data allowed easier and more accurate mapping of wet areas as well as the extracting of their hydraulic characteristics. However, the ecohydrological models involved several sources of uncertainties, which need to be carefully addressed with extensive observational data, expert knowledge of model parameter definitions, proper modeling unit selection and empirical knowledge of the functioning of the studied watershed system. The results of this dissertation highlight the importance of combined methods for watershed management research, and the proper identification of the biophysical processes in the modeling of non-point pollutant sources; this can in turn lead to an efficient water protection measure, and restoring biogeochemical hotspot areas within the watershed.Vedenlaadun alueellisten ja ajallisten vaihteluiden mallintaminen viileän vyöhykkeen valuma-alueilla. Maankäytön muutokset ovat vaikuttaneet luonnollisiin hydrologisiin prosesseihin sekä hiilen, typen ja fosforin biogeokemiallisiin kiertoihin. Nämä puolestaan vaikuttavat vesiekosysteemien tilaan joissa, järvissä ja rannikkoalueella. Väitöstutkimuksessa tutkittiin vedenlaadun alueellisia ja ajallisia muutoksia suomalaisessa maaseutumaisemassa käyttäen monimuuttujamenetelmiä, aikasarja-analyysejä, ekohydrologista mallinnusta ja erotuskyvyltään tarkkoja paikkatietoaineistoja. Tulokset todentavat maatalouteen kytkeytyvien maankäytön piirteiden kompleksisia vaikutuksia jokivesien laatuun. Aikasarja-analyysit osoittivat myös aiemmin tuntemattomia trendejä jokivesien ravinteiden määrissä ja pitoisuuksissa, esimerkkeinä liuenneen reaktiivisen fosforin määrän ja pitoisuuden lisääntyminen sekä sedimenttisuspension väheneminen; molemmat eroosion vähentämiseen tähtäävien vesiensuojelutoimien seurauksena. Ekohydrologinen mallinnus osoitti myös sen, että ravinteiden huuhtoutuminen maatalousvaltaisilla valuma-alueilla lisääntyy ilmastonmuutoksen seurauksena. Tulokset kannustavat biogeokemiallisten avainalueiden, kuten kosteikkojen ja vettä keräävien painanteiden kunnostamiseen, jolloin ravinteiden huuhtoutuminen vähenee. Ravinnenieluina toimiessaan ne voivat myös parantaa valumaalueen ekologista kestävyyttä ja palautumiskykyä. Tutkimuksessa osoitettiin myös erotuskyvyltään tarkkojen paikkatietoaineistojen hyödyllisyys avainalueiden kartoituksessa ja alueiden hydrologisten ominaisuuksien tunnistamisessa. Ekohydrologiseen mallinnukseen sisältyy toisaalta myös epävarmuustekijöitä, joihin tulisi paneutua vielä kattavammin hyödyntäen asiantuntijatietoa parametrien täsmentämisessä, määrittämällä tarkennettuja mallinnusyksiköitä tai hyödyntäen empiirisiä tutkimustietoja valuma-alueen toiminnasta. Väitöstutkimus osoittaa myös sen, miten erilaisten tutkimusmenetelmien yhdistely vahvistaa valuma-aluetarkastelua ja siihen liittyen erilaisten biofysikaalisten prosessien ymmärtämistä ja keskeisten päästölähteiden mallintamista. Näin muodoin yhdistelmämenetelmien käyttö tukee entistä tehokkaampien vesiensuojelutoimien kehittämistä ja valumaalueiden biogeokemiallisten avainalueiden kunnostamistaModelado de las tendencias temporales y espaciales de la calidad del agua en cuencas hidrográficas boreales manejados. El cambio del uso del suelo ha alterado los procesos hidrológicos naturales y los ciclos biogeoquímicos del carbono, el nitrógeno y el fósforo, entre otros elementos, afectando directamente la calidad de los ecosistemas acuáticos como los ríos, lagos y zonas costeras. En esta disertación, las tendencias espaciales y temporales de la variación de la calidad del agua en cuencas hidrográficas finlandesas se estudiaron mediante la aplicación de métodos de estadística multivariante, análisis de series de tiempo, modelos ecohidrológicos y datos geoespaciales de alta resolución. Los resultados muestran los efectos complejos del uso actual del suelo, particularmente la agricultura, en la calidad del agua de los ríos y corrientes. Se detectaron nuevas tendencias emergentes de concentraciones y cargas de nutrientes en el análisis de series temporales, como un aumento en la concentración y carga del fósforo disuelto reactive y nitrógeno total, y una disminución en la concentración de sedimentos en suspensión en los ríos y corrientes. Esto podría estar vinculado a la estrategia actual de manejo del suelo, orientado a la reducción de la erosión para la protección del agua. Una evaluación a través de modelización ecohidrológica mostró un aumento de la exportación de nutrientes aguas abajo de la cuenca agrícola bajo escenarios de cambio climático. Los resultados de la modelización también mostraron una posible reducción de la exportación de nutrientes mediante la restauración de posibles zonas críticas biogeoquímicas: áreas húmedas o áreas propensas a la saturación de agua. Estas áreas pueden funcionar como sumideros de nutrientes y mejorar la resiliencia de la cuenca. Los datos geoespaciales de alta resolución permitieron un fácil y más preciso cartografiado de las áreas húmedas, así como la extracción de sus características hidráulicas. Sin embargo, los modelos ecohidrológicos involucraron varias fuentes de incertidumbre, que deben abordarse cuidadosamente con bastantes datos de observación, conocimiento experto de las definiciones de los parámetros del modelo, selección adecuada de la unidad de modelado y conocimiento empírico del funcionamiento del sistema de la cuenca estudiada. Los resultados de esta disertación destacan la importancia de los métodos combinados para la investigación de gestión de cuencas hidrográficas y la identificación adecuada de los procesos biofísicos en la modelización de fuentes contaminantes difusas; esto a su vez puede conducir a una medidaeficiente de protección del agua, y restauración de áreas claves de alta función biogeoquímica dentro de la cuenca