The unfolded protein response, which is activated during ER stress, counteracts stress conditions by increasing folding capacity and by increasing the degradation of misfolded ER proteins by the ER-Associated Degradation (ERAD) system. Studies using an engineered insulinoma cell line with inducible expression of the Akita folding-deficient insulin have shown a large induction of Herp, a protein that has been implicated in the ERAD pathway. We hypothesized that Herp is an essential protein that regulates the degradation of misfolded insulin during the ER stress response. Indeed, we found that the degradation of mutant insulin is Herp-dependent and that maintaining Herp expression is vital for maintaining cell survival. We have also observed that the expression of Herp mRNA and protein is induced in various cell culture and animal models of diabetes. These results suggest that Herp is an important ER stress response protein that is induced under diabetic conditions in pancreatic β-cells.

The unfolded protein response, which is activated during ER stress, counteracts stress conditions by increasing folding capacity and by increasing the degradation of misfolded ER proteins by the ER-Associated Degradation (ERAD) system. Studies using an engineered insulinoma cell line with inducible expression of the Akita folding-deficient insulin have shown a large induction of Herp, a protein that has been implicated in the ERAD pathway. We hypothesized that Herp is an essential protein that regulates the degradation of misfolded insulin during the ER stress response. Indeed, we found that the degradation of mutant insulin is Herp-dependent and that maintaining Herp expression is vital for maintaining cell survival. We have also observed that the expression of Herp mRNA and protein is induced in various cell culture and animal models of diabetes. These results suggest that Herp is an important ER stress response protein that is induced under diabetic conditions in pancreatic β-cells.

La hipòtesi de treball d'aquesta tesi es que les malalties neurodegenerativespoden considerarse formes accelerades de l'envelliment, selectives per adeterminades localitzacions anatòmiques del teixit nerviós. D'acord a això, aquellsprocessos subjacents a les bases biològiques de l'envelliment (estrès oxidatiu,accumulació de proteïnes agregades, disfunció mitocondrial) i les sevesconseqüències son més intenses i prematures en aquestes poblacions cel.lulars.L'objectiu d'aquest treball es investigar la possible relació entre estrès oxidatiu ide retícle (ER) i les vies de senyalització iniciades per ambdós processos, com amecanisme patogènic en el desenvolupament de les malalties neurodegeneratives, dediferents localitzacions i caracteritzades per la presència d'agregats proteics. Així,hem caracteritzat la modificació oxidativa proteica, els seus causants més importants iles seves conseqüències fisiopatològiques en la forma esporàdica de l'esclerosi lateralamiotròfica (ELA) amb inici lumbar, en la taupatia frontotemporal malaltia de Pick(MdP) i en la malaltia de granuls argirofílics (MGA). Els resultats dels analisis demostres de pacients amb ELA s'han comparat amb els obtinguts en models in vitro dela malaltia.Desprès de la caracterització anatomopatològica exhaustiva, les mostres demèdul.la espinal (ME) i d'escorça frontal (EF) de malalts amb ELA, d'escorça occipital(EO) i EF de malalts amb MdP, i d'hipocamp (HC) de malalts amb MGA, es varenanaltizar en comparació amb mostres d'individus sans amb edats comparables. Laconcentració de marcadors de vies específiques de modificació oxidativa proteica(oxidació directa, glicoxidació i lipoxidació), així com la composició en àcids grasos esva analitzar mitjançant espectrometria de masses combinada amb separaciócromotogràfica. Com a factors reguladors d'oxidació proteica es varen emprar laquantitat de complexes respiratoris mitocondrials, sistemes de defensa antioxidant isistemes proteolíticis, estimats mitjançant western-blot. A més s'establí, emprant lamateixa metodologia, les conseqüències en forma d'ER i de resposta a proteïnesdesplegades (RPD). Així mateix, s'estimà la biogènesi mitcondrial mitjançant anàliside la quantitat de factors reguladors de la mateixa, mitjançant western-blot.Les mostres dels pacients amb ELA mostraren increments en els marcadorsd'oxidació directa, glicoxidació i lipoxidació en ME, i, de forma menys important, enmostres d'EF. Això s'associava a un increment en peroxidizabilitat lipídica, i a unadisminució de respostes neuroprotectores, degut a la disminució en el contingut d'àciddocosahexaenoic, i a alteracions proteasomals i en el contingut de complexesrespiratoris mitocondrials. Es va evidenciar estrés de reticle en ME, però no a l'EF.Així, es va concloure que l'ELA esporàdica duu a increments en lesió oxidativaproteica i a estrés de reticle en ME, mentres que a EF, hi ha menys afectació, bo i noestar indemne.D'altra banda, en mostres de EF, però no en EO de MdP, es varen detectarevidències compatibles amb estrés de reticle, com la RPD, associada a deplecció dexaperones de reticle. Aquestes troballes es relacionen amb un increment en laubiquitinització, compatible amb alteracions en l'activitat proteasomal. En EF, es varentrobar increments en lesió oxidativa directa i lipoxidació, afectant a enzimsantioxidants, amb disminució en la concentració de marcadors de glicoxidació.Sorprenentment, es varen evidenciar increments a la majoria de marcadors de lesióoxidativa en EO, localització morfològicament preservada a la MdP. Els canvispresents en aquesta malaltia s'associaven a canvis en la dotació de complexesrespiratoris mitocondrials, compatibles amb pèrdues de biogenesi mitocondrial i dedefensa antioxidant, combinats amb deplecció de l'àcid docosahexaenoic, consideratun neuroprotector, en EF. En aquest context, el contingut dels factors de transcripciórelacionat amb respostes antioxidants i amb biogènesi mitocondrial, mostrarendisminucions significatives en EF i de forma menys marcada, a EO. En contrast,mentres que a EO es va veure increment d'estrés oxidatiu, les cadenes respiratoriesmitocondrials i la biogenesi no semblaven afectades, de forma conjunta amb unincrement d'àcid docosahexaenoic, suggerint una resposta apropiada a l'estrésoxidatiu.L'anàlisi dels marcadors d'estrés oxidatiu en HC de MGA revelarendisminucions significatives en marcadors de glicoxidació, de manera similar a MdP,troballes compatibles amb un dèficit glicolitic. Aquests defectes glicolítics, s'han descritpreviament en altres malalties neurodegeneratives i podrien associarse amodificacions oxidatives d'enzims glicolítics, també evidenciats aquí. Això suggerreixun paper preferencial d'altres modalitats de lesió oxidativa, com la lipoxidació, comevidencien els increments en concentració de malondialdehid-lisina en aquestamalaltia. La medició dels carbonils proteics va reforçar l'existència d'estrés oxidatiu aHC, atribuible a la disfunció mitocondrial, evidenciada per canvis en complexes i en elnombre de mitocondris. Així mateix, diverses molecules clau en la RPD varen mostrarincrements a les mostres procedents de malalts de MGA, causant increments a lesxaperones de reticul endoplasmàtic. De forma remarcable, a pesar de les troballescompatibles amb la reducció mitocondrial, els factors transcripcionals implicats en laseva biogènesi no s'elevaren, suggerint que un defecte en biogènesi mitocondrialpodria estar implicat a la patogenesi de la MGA.Els resultats descrits a la present memòria de tesi, indiquen la relació entreestrés oxidatiu i de retícul endoplasmàtic, en ELA, MdP i MGA, suggerint la sevarelació recíproca, a travès de disfunció proteolítica, i un paper clau de la funciómitocondrial, o la seva pèrdua, conduint al procès neurodegeneratiu. / La hipótesis a contrastar en esta tesis es que las enfermedadesneurodegenerativas (ENDs) pueden ser una forma acelerada del envejecimiento,selectiva para determinadas localizaciones anatómicas del tejido nervioso.Consiguientemente, aquellos procesos subyacentes en las bases biológicas delenvejecimiento (estrés oxidativo, acumulación de proteínas con alto grado deagregación, disfunción mitocondrial) y sus consecuencias son más intensas yprematuras en estas poblaciones celulares.El objetivo de este trabajo es investigar la posible interrelación entre estrésoxidativo y de retículo (ER) y vías de señalización iniciadas por ambos procesos,como mecanismo patogénico en el desarrollo de ENDs de diferentes localizaciones ycaracterizadas por la presencia de agregados proteicos. Así, hemos caracterizado lamodificación oxidativa proteica, sus causantes más importantes y sus consecuenciasfisiopatológicas en la forma esporádica de esclerosis lateral amiotrófica (ELA) coninicio lumbar, en la taupatía frontotemporal enfermedad de Pick (EdP) y en laenfermedad de granos argirofílicos (EGA). Los resultados de los análisis de muestras de pacientes con ELA se ha comparado con los obtenidos en modelos in vitro de laenfermedad.Tras caracterización anatomopatógica exhaustiva, las muestras de médulaespinal (ME) y de córtex frontal (CF) de pacientes de ELA; de córtex occipital (CO) yCF de enfermos de EdP, y de hipocampo (HC) de pacientes con EGA, se analizaronen comparación con muestras de individuos sanos con edades comparables. Laconcentración de marcadores de vías específica de modificación oxidativa proteica(oxidación directa, glicoxidación y lipoxidación), así como la composición en ácidosgrasos se analizaron mediante espectrometría de masas combinada concromatografía. Como factores reguladores de oxidación proteica se tomaron lacantidad de complejos respiratorios mitocondriales, sistemas de defensa antioxidantey sistemas proteolíticos, estimados mediante análisis de wester-blot. Además, seestableció mediante la misma metodología, las consecuencias en forma de ER y derespuesta a proteínas desplegadas (RPD). Asimismo, se estimó la biogenésismitocondrial mediante análisis de la cantidad de factores reguladores de la misma,mediante western-blot.Las muestras con ELA mostraron incrementos en los marcadores de oxidacióndirecta, glicoxidación y lipoxidación en ME, y, de forma menor cuantitativamente, enmuestras de CF. Ello se asoció a un incremento en la peroxidizabilidad lipídica, y auna disminución de respuestas neuroprotectoras debido a la disminución en el contenido de ácido docosahexaenoico y a alteraciones del proteasoma y en elcontenido de complejos respiratorios mitocondriales. Se evidenció estrés de retículoen ME, pero no en CF. Consiguientemente, se concluyó que la ELA esporádicaconlleva incremento en lesión oxidativa proteica y a estrés de retículo en médulaespinal, mientras que el CF, muestra menor afectación, pero no esta indemne.Por otro lado, en muestras de CF, pero no en CO de EdP, se detectaronevidencias de estrés de retículo, como RPD, asociadas a pérdida de chaperonas deretículo. Estos hallazgos se relacionan con un incremento en la ubiquitinizacióncompatible con alteraciones en la actividad proteasomal. En esta localización (CF), sehallaron incrementos en lesión oxidativa directa y lipoxidación, dirigidas a enzimasantioxidantes, con disminución en la concentración de marcadores de glicoxidación.Sorprendentemente, se demostraron incrementos en la mayoría de marcadores delesión oxidativa en CO, localización morfológicamente preservada en EdP. Loscambios presentes en esta enfermedad se asociaron a cambios en la dotación decomplejos respiratorios mitocondriales, compatibles con pérdida de biogénesismitocondrial y de defensa antioxiante, combinados con depleción del ácidodocosahexaenoico, considerado como neuroprotector, en CF. En este contexto, elcontenido de los factores de transcripción relacionados con respuestas antioxidantesy con biogénesis mitocondrial, mostraron cambios significativos en CF y menosmarcados en CO. En contraste, mientras que en CO se observó incremento en lesiónoxidativo en EdP, las cadenas respiratorias mitocondriales y la biogénesis podríanestar preservadas, de forma conjunta con un incremento de ácido docosahexaenoico,sugiriendo una respuesta apropiada al estrés oxidativo.El análisis de los marcadores de estrés oxidativo en HC de EGA revelarondisminuciones significativas en marcadores de glicoxidación, de modo similar a EdP,hallazgos compatibles con un déficit de glicolisis en esta situación. Estos defectos sehan descrito previamente en otras ENDs y pueden asociarse a modificacionesoxidativas de enzimas glicolíticos, tambien evidenciados aquí. Ello sugiere un papelpreferencial de otros modos de lesión oxidativa, como la lipoxidación, como evidencian los incrementos en concentración de malondialdehido-lisina en estaenfermedad. La medición, mediante western-blot, de los carbonilos proteicos reactivosreforzó la existencia de estrés oxidativo en HC, atribuible a la disfunción mitocondrialevidenciable por cambios en la función respiratoria y en su número. Asimismo,diversas moléculas clave en la RPD mostraron incrementos en las muestrasprocedentes de enfermos, causando incrementos en chaperonas de retículoendoplasmatico. De forma remarcable, a pesar del número reducido de mitocondrias,los factores transcripcionales implicados en su biogénesis no se elevaron, sugiriendo que un defecto en biogénesis mitocondrial puede estar implicado en la patogénesis deEGA.Los resultados descritos en esta memoria de tesis indican la interrelación entreestrés oxidativo y de retículo endoplasmatico, en ELA, EdP y EGA sugiriendo surelación recíproca a través de disfunción proteolítica, y un papel clave de la funciónmitocondrial, conduciendo al proceso neurodegenerativo. / It is hypothesized that the neurodegenerative diseases (NDDs) could be anaccelerated form of aging selective for nervous tissue in specific anatomic locations.Accordingly, the processes observed in the biological basis of aging (oxidative stress,accumulation of highly modified protein aggregates, mitochondrial dysfunction) and theensuing processes that it triggers are more intense and premature in these cellpopulations.The aim of this work was to investigate the potential interplay betweenoxidative and endoplasmic reticulum (ER) stress and the underling signallingpathways, as a potential mechanism involved in the pathogenesis of theneurodegenerative disorders affecting different locations, and characterized by proteinaggregates. We characterized protein oxidative damage, its major contributors and itspathophysiological consequences in the sporadic form of amyotrophic lateral sclerosis(ALS) patients with lumbar onset disease, in the frontotemporal tauopathy Pick'sdisease (PiD) and in the argyrophilic grain disease (AGD) patients. The results of ALSsamples were compared with in vitro models of the disease.After extensive pathological characterization, samples from spinal cords (SC)and frontal cortex (FC) from ALS patients, FC and occipital cortex (OC) from PiDpatients, and hippocampus (HC) from AGD patients were analyzed in comparison withage-matched control samples. The concentration of markers for specific pathways ofprotein oxidative damage (direct oxidation, glycoxidation and lipoxidation) and fattyacid composition were assessed by mass spectrometry. Contributors to proteinoxidation (mitochondrial respiratory complexes, antioxidant defence and proteolysis)and its consequences (endoplasmic reticulum stress and/or unfolded protein response(UPR)) were evaluated by western-blot of specific markers. Furthermore, themitochondrial biogenesis system was assessed by measuring by western blot thelevels of key factors.ALS was associated to increased direct oxidative, glycoxidative and lipoxidativedamage in SC and, to a lower extent, in FC samples. This was associated to increasedlipid peroxidizability, and to impaired neuroprotective responses because of decreaseddocosahexaenoic content as well as alterations of the mitochondrial respiratorycomplexes and proteasomal impairment. Endoplasmic reticulum stress was evidencedin SC, but not in FC. Therefore, it could be concluded that sporadic ALS leads toincreased oxidative damage in proteins and to ER stress in SC, while FC is lessaffected, but not preserved.In samples from FC, but not in OC of PiD, there were evidences of ER stresssuch as activated UPR, associated to specific depletion in ER chaperones. Thosefindings are related to increased ubiquitination compatible with alteration in ubiquitinproteasomesystem. In the same location, evidences for increased direct oxidative andlipoxidative damages targeting antioxidant enzymes were found, with decreasedamount of glycoxidation markers. Strinkingly, increases in most of the examinedparameters of oxidative stress in morphologically preserved OC of PiD patients weredetected as well. The changes registered in PiD could be associated with disturbancesin mitochondrial respiratory complexes compatible with diminished mitochondrialbiogenesis and lack of antioxidant defence, combined with depletion in the contents ofthe neuroprotective docosahexaenoic acid observed in FC. In this line, the content ofthe transcription factors related to antioxidant responses and mitochondrial biogenesisshowed significant changes in FC but less marked in OC. In contrast, while OCshowed increased oxidative damage, mitochondrial respiratory chain and biogenesiswere preserved, a finding associated to increased docosahexaenoic content,suggesting an appropriate response to the generated increase in oxidative stress.Analysis of various oxidative stress biomarkers in HC of AGD revealedsignificantly decreased levels of the markers of glycoxidation, similarly to PiD, which iscompatible with defects in glycolytic potential in this location. Those defects have beenpreviously reported in other NDDs and may be associated to oxidative modifications ofglycolytic enzymes also evidenced here. There were no changes in the concentrationsof direct protein oxidation markers. This suggests a preferential role of other forms ofoxidative damage, such as lipoxidation, as evidenced by increased malondialdehydelysinelevels in this disease. Western blot measurements also revealed increasedprotein reactive carbonyl groups further supporting elevated oxidative damage in HCof AGD samples, which can be attributed to the mitochondrial dysfunction evidencedby disturbance in the respiratory chain function and reduced mitochondria number.Furthermore, the key molecules critically involved in UPR were found activated, whichcaused elevation in ER chaperones. Most importantly, despite the reduced number ofmitochondria, transcription factors for their biogenesis were not increased, suggestingthat impaired mitochondria biogenesis may be implicated in AGD pathogenesis.The described results indicate the implication of oxidative and endoplasmicreticulum stress in sporadic ALS, PiD and AGD suggesting a possible interplaybetween them through proteolysis dysfunction, with a predominant role ofmitochondrial impairment leading to the neurodegenerative process.

In this study our purposes were to investigate the spatial distribution and seasonal variation of polycyclic aromatic hydrocarbons (PAHs) in the dissolved and particulate phase of PAHs in Er-Jen River. In addition, the potential sources of PAHs in Er-Jen River were investigated not only by finger printing, but also principal component analysis (PCA) and hierarchical cluster analysis (HCA). ¡@¡@Concentrations of dissolved and particulate PAHs ranged from 13.8 to 516 ng/L and from 4.05 to 55.9 ng/L, respectively. In March (dry season), concentrations of dissolved and particulate PAHs ranged from 38.3 to 186 ng/L and from 4.05 to 25.9 ng/L, respectively. In addition, concentrations of dissolved and particulate PAHs ranged from 32.3 to 82.8 ng/L and from 14.8 to 85.3 ng/L, respectively in September (wet season). The highest total PAH concentration in this area was found in Station Er-3 which is located on a tributary of Er-Jen River. Total PAH concentrations in wet season were higher than those found in dry season for all stations in Er-Jen River, except for station Er-3, which suggesting that different geography might be the reason. ¡@¡@Results from correlation analysis indicated that distributions of PAH concentrations for particulate phase in Er-Jen River correlated well with flow rate, suspended solid concentrations and salinity. Total PAH concentration of station Er-2, which was located at the downstream Er-Jen River, was highly correlated with salinity; while total PAH concentrations in other stations were mainly affected by flow rate, suspended solid concentrations and some potential sources of pollution. Results from PCA, HCA and finger printing all indicated the origins of PAHs were complex sources in the study area, including pyrogenic, petrogenic and diagenetic/biogenic origins. The origins of PAHs in dissolved phase were mainly from both pyrogenic and petrogenic sources; while those in particulate phase were mainly from pyrogenic sources. In addition, the pyrogenic origins in both dissolved and particulate phase were mostly from liquid fuel combustion. In wet season, howerer, diagenetic/biogenic origins were also found in particulate phase at the sampling sites of Er-Jen River. ¡@¡@The annual total PAH fluxes of Er-Jen River were estimated to be 23.1 kg For dissolved phase, the average daily fluxes in dry and wet season were 5.9 g/day and 65.8 g/day, respectively, with an annual mean fluxe of 11.3 kg/year. For particulate phase, the mean daily fluxes in dry and wet season were 0.8 g/day and 76.2 g/day, respectively, with an annual mean flux of 11.8 kg/year. In general, the total PAH fluxes in wet season were higher than dry season. The total annual PAH fluxes in Er-Jen River were generally less than those reported worldwide, and comparable to those in San Francisco River in USA, but higher than those in Le Havre River in France.

Abstracts Photoreflectance(PR) of surface-intrinsic n+ type doped GaAs has been measured for various power densities of pumping laser.The spectra exhibited many Franz-Keldysh oscillations,where by the electric field(F) can be determined from the technique of the fast fourier transform.It is known that F's determined from PR are subjected to photovoltaic effect ,but it is difficult to estimate the strength of modulating field in the PR measurements.Hence we have investigated the relation between F and modulating field by using electroreflectance to simulate PR.In this work,the relation will be confirmed by using solely PR.Here a method was devised to obtain the strength of modulating field in the PR measurements.The photo-voltage(Vs)of the pump beam can be measured directly with a lock-in amplifier by making electrical contacts on the front and rear sides of the sample.The strengh of modulation field is equal to Vs/d due to a uniform F in the undoped layer,where d is the thickness of the undoped layer.

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This research combines relational database framework and quantitative equity portfolio models based on the Barra Risk Model Handbook standard steps to design a database and computer platform for multi-factor risk management tasks. The multi-factor model facilitates fast search and efficient selection of descriptors with explanatory power for future stock returns. The design of database is divided into three steps. First, descriptors are calculated and daily-update modules constructed. This study finds 48 key descriptors which play important roles in explaining stock returns of Taiwan. Second, entity relational model is applied to sort out linkages between pieces of important information in the factor model. Lastly, database auto-run procedures are setup to update the latest raw data on a monthly basis. Model parameter update and portfolio rebalancing is hence made seamless to meet practical operation demand for such a platform. The development of the Multi-factor risk model is divided into five main steps. (1) Finding significant descriptors. (2) Forming common factors from descriptors. (3) Developing a multi-factor return model. (4) Developing a multi-factor risk model. (5) Running performance analysis and back-testing. The empirical results show that the average adjusted R-squared of the MFM model is 0.5 during the period of 1998/04~2005/11. For combining descriptors into common factors, we run factor analysis. The multi-collinearity problem existing in the descriptors is well taken care of by such procedures. We use the exponentially weighted averaging method to compute the factor returns and forecast stock ranking. A half-life of 24 months appears to deliver the best performance in Taiwan stock market.

This Master’s thesis analyze application of information technology in education process, examination using testing method and possibility of computerized testing systems in Lithuanian schools. Rapid development of information and communication technologies inevitably affect and change all spheres of the society including education. Moreover, new technologies change and enrich ordinary methods of examination. One of the most important tasks of the education system is to ascertain the level of knowledge acquired or in other words to examine pupils knowledge. So, one of most easily computerized examination forms is testing method. This method has its own shortcomings, but is rather widespread due to its convenience and easy formalization. A new general standard of computer literacy was prepared on 31st January 2002. Its aim is to ascertain the minimum skills of computer usage by pupils. This year the first school leavers well pass the test on computer literacy. The purpose of the test is to examine their knowledge of information technologies and the mastering level of minimum skills of computer usage. Questionnaire of the teachers and pupils shows that testing method is acceptable and the computer in classes is awaited. The aim of the master’s research is to analyze the efficiency of special computer programmers in developing and examining skills of computer literacy in secondary schools. The tasks of research are to analyze the ways of testing, to prepare some tests... [to full text]

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The place of data modelling in information systems‘ life cycle and the importance of data model quality in effective IS exploitation are shown in this masters' work. Refering to results of the nonfiction literature analysis the reasons why the process of data modelling must be automated are introduced; current automatization solutions are described. And as it is the main purpose of this work an original data modelling method is described and programmable prototype which automates one step of that method – schema integration is introduced.