Towards Lane-Keeping Electronic Stability Control for Road-Vehicles

The emerging new idea of lane-keeping electronic stability control is investigated. In a critical situation, such as entering a road curve at excessive speed, the optimal behavior may differ from the behavior of traditional ESC, for example, by prioritizing braking over steering response. The important question that naturally arises is if this has a significant effect on safety. The main contribution here is to give a method for some first quantitative measures of this. It is based on optimal control, applied to a double-track chassis model with wheel dynamics and high-fidelity tire-force modeling. The severity of accidents grows with the square of the kinetic energy for high velocities, so using kinetic energy as a measure will at least not overestimate the usefulness of the new safety system principle. The main result is that the safety gain is significant compared to traditional approaches based on yaw rotation, for several situations and different road-condition parameters

A solanesyl-diphosphate synthase localizes in glycosomes of Trypanosoma cruzi

Fil: Ferella, Marcela. ANLIS Dr. C. G. Malbrán. Instituto Nacional de Parasitología "Dr. M. Fatala Chabén" (INP); Argentina.Fil: Montalvetti, Andrea. University of Illinois. Department of Pathobiology; Estados Unidos.Fil: Rohloff, Peter. University of Illinois. Department of Pathobiology; Estados Unidos.Fil: Miranda, Kildare. University of Georgia. Center for Tropical and Emerging Global Diseases. Department of Cellular Biology; Estados Unidos.Fil: Fang, Jianmin. University of Georgia. Center for Tropical and Emerging Global Diseases. Department of Cellular Biology; Estados Unidos.Fil: Reina, Silvia. ANLIS Dr. C. G. Malbrán. Instituto Nacional de Parasitología "Dr. M. Fatala Chabén" (INP); Argentina.Fil: Kawamukai, Makoto. University Matsue. Faculty of Life and Environmental Science. Department of Applied Bioscience and Biotechnology; Japón.Fil: Bua, Jacqueline. ANLIS Dr. C. G. Malbrán. Instituto Nacional de Parasitología "Dr. M. Fatala Chabén" (INP); Argentina.Fil: Nilsson, Daniel. Karolinska Institute. Center for Genomics and Bioinformatics; Suecia.Fil: Pravia, Carlos. ANLIS Dr. C. G. Malbrán. Instituto Nacional de Parasitología "Dr. M. Fatala Chabén" (INP); Argentina.Fil: Katzin, Alejandro. Universidade de Sao Paulo. Instituto de Ciencias Biomédicas. Departamento de Parasitologia; Brasil.Fil: Casera, María B. Universidade de Sao Paulo. Instituto de Ciencias Biomédicas. Departamento de Parasitologia; Brasil.Fil: Áslund, Lena. Uppsala University. Department of Genetics and Pathology; Suecia.Fil: Andersson, Björn. Karolinska Institute. Center for Genomics and Bioinformatics; Suecia.Fil: Docampo, Roberto. University of Illinois. Department of Pathobiology; Estados Unidos.Fil: Bontempi, Esteban. ANLIS Dr. C. G. Malbrán. Instituto Nacional de Parasitología "Dr. M. Fatala Chabén"; Argentina.We report the cloning of a Trypanosoma cruzi gene encoding a solanesyl-diphosphate synthase, TcSPPS. The amino acid sequence (molecular mass ∼ 39 kDa) is homologous to polyprenyl-diphosphate synthases from different organisms, showing the seven conserved motifs and the typical hydrophobic profile. TcSPPS preferred geranylgeranyl diphosphate as the allylic substrate. The final product, as determined by TLC, had nine isoprene units. This suggests that the parasite synthesizes mainly ubiquinone-9 (UQ-9), as described for Trypanosoma brucei and Leishmania major. In fact, that was the length of the ubiquinone extracted from epimastigotes, as determined by high-performance liquid chromatography. Expression of TcSPPS was able to complement an Escherichia coli ispB mutant. A punctuated pattern in the cytoplasm of the parasite was detected by immunofluorescence analysis with a specific polyclonal antibody against TcSPPS. An overlapping fluorescence pattern was observed using an antibody directed against the glycosomal marker pyruvate phosphate dikinase, suggesting that this step of the isoprenoid biosynthetic pathway is located in the glycosomes. Co-localization in glycosomes was confirmed by immunogold electron microscopy and subcellular fractionation. Because UQ has a central role in energy production and in reoxidation of reduction equivalents, TcSPPS is promising as a new chemotherapeutic target

The Short Non-Coding Transcriptome of the Protozoan Parasite Trypanosoma cruzi

The pathway for RNA interference is widespread in metazoans and participates in numerous cellular tasks, from gene silencing to chromatin remodeling and protection against retrotransposition. The unicellular eukaryote Trypanosoma cruzi is missing the canonical RNAi pathway and is unable to induce RNAi-related processes. To further understand alternative RNA pathways operating in this organism, we have performed deep sequencing and genome-wide analyses of a size-fractioned cDNA library (16–61 nt) from the epimastigote life stage. Deep sequencing generated 582,243 short sequences of which 91% could be aligned with the genome sequence. About 95–98% of the aligned data (depending on the haplotype) corresponded to small RNAs derived from tRNAs, rRNAs, snRNAs and snoRNAs. The largest class consisted of tRNA-derived small RNAs which primarily originated from the 3′ end of tRNAs, followed by small RNAs derived from rRNA. The remaining sequences revealed the presence of 92 novel transcribed loci, of which 79 did not show homology to known RNA classes

Lärande inom Polismyndigheten som en effekt av arbetsrotation: intervjuer med "arbetsroterade" och deras chefer

Polismyndigheten har som organisation genomgått stora förändringar. För att möta dessa förändringar startade Polismyndigheten i Skåne 1997 ett arbetsrotationsprogram, vilket i kombination med andra kompetensutvecklings-åtgärder syftade till att skapa en lärande organisation. Tanken var att deltagarna i programmet skulle få nya kunskaper och att de skulle sprida sin kunskap och kompetens inom organisationen. Syfte med uppsatsen är att genom en målfri effekt-utvärdering studera vilka effekter som Arbetsrotations-programmet har inneburit för individen och för organisationen. För att besvara syftet har vi med en abduktiv ansats genomfört en kvalitativ empirisk undersökning med hjälp av semistrukturerade intervjuer. Vi har intervjuat sex deltagare och fyra berörda chefer. Vi har sedan försökt att tolka de effekter som framkommit av den empiriska undersökningen med hjälp av en tolkningsmodell i tre steg som vi hämtat från Kvale (1997). Resultatet av undersökningen visar att Arbetsrotations-programmet i praktiken har fungerat som två olika program med två olika syften; ett kompetensutvecklande och ett personalvårdande syfte. Effekterna har framför allt blivit ett individuellt lärande och vad vi vill kalla för en nytändning för deltagarna. Det organisatoriska lärandet har däremot varit litet. En tänkbar förklaring till resultatet är att Arbetsrotations-programmets kompetensutvecklande syfte inte varit tydligt. Det har inte heller funnits gemensamma riktlinjer kring hantering av personal inom ramen för programmet och stödet till cheferna och deltagarna när de återvänt har inte varit tillräckligt

Hur ser den pedagogiska processen ut för ett arbetsplatsombud?: En empirisk undersökning i en facklig organisation

Vi har i vårt uppsatsarbete valt att studera de fackligt engagerade arbetsplatsombudens vardag ur ett pedagogiskt perspektiv. Då vår frågeställning är av explorativ art ansåg vi att en kvalitativ ansats var att föredra. Vi har genomfört ett antal semistrukturerade intervjuer med dels utbildningsansvariga vid två regionalavdelningar samt ett antal arbetsplatsombud. Vid genomförandet av intervjuerna åkte vi ut på arbetsplatserna för att underlätta för ombuden. Vi hade gjort en intervjuguide som vi skickade till de ombud som ville förbereda sig. För att underlätta vårt eget fortsatta arbete med intervjumaterialet spelade vi in alla intervjuerna på en mp3 spelare. De områden i ombudets arbete vi valde att fokusera på var vad som motiverar individen. Vilken möjlighet som finns att kunna påverka något efter genomgångna utbildningar. Vi har även intresserat oss för olika lärprocesser samt metoder som kan kopplas till dessa teorier. Individens handlingsutrymme styrs dels av styrdokument men även ombudet och organisationen i förhållande till chefer och arbetskamrater. I den teoretiska delen, som vi har genomfört har vårt fokus riktats på litteratur som kretsar kring de nyckelord vi har använt exempelvis: påverkan, lärande, kunskapsanvändning, handlingsutrymme. Vi har ansträngt oss för att komplettera den vanliga litteraturen med några vetenskapliga artiklar. Vår avsikt har också varit att använda primärkällor. Arbetsplatsombudens motivation och intresse har klart överträffat de förväntningar vi hade innan arbetets början. Utbildningsinsatser fungerar som en drivkraft för vissa ombud då man menar att möjligheterna att påverka ökar i takt med kunskaperna

Personlig utveckling under polisutbildningen

Syftet med arbetet är att belysa de eventuella förändringar studenter på polisutbildningen vid Umeå universitet genomgår. Människor, platser, behovet av att passa in och grupper påverkar oss hela livet och enligt vår mening har de flesta i vår umgängeskrets på ett eller annat sätt förändrats sen dem kom in på polisutbildningen. Vad anbelangar arbetets del om personlig utveckling är den avgränsad till att endast undersöka den personliga utvecklingen hos polisstudenter vid Umeå Universitet, vi har också bara riktat in oss på studenter som går i termin 4. I undersökningen har vi att använt av oss enkäter bestående av 44 frågor som sedan slumpmässigt delats ut till 39 studenter. Angående de förändringar vi kunnat påvisa var vårt mål att sedan försöka koppla dem till olika teorier om grupper. Då vissa av dessa förändringar hade att göra med polisens kåranda ville vi även belysa eventuella kopplingar till denna. Utifrån analysen så har vi kunnat se sammanband med de teorier vi valt att fördjupa oss i. Stora delar av resultatet blev som väntat medan vissa svar var överraskande och inte alltid positiva

Studying the influence of roll and pitch dynamics in optimal roadvehicle maneuvers

A comparative analysis shows how vehicle motion models of different complexity, capturing various characteristics, influence the solution when used in time-critical optimal maneuvering problems. Vehicle models with combinations of roll and pitch dynamics as well as load transfer are considered, ranging from a single-track model to a double-track model with roll and pitch dynamics combined with load transfer. The optimal maneuvers in a 90 ◦-turn and a double lane-change scenario are formulated as minimum-time optimization problems, and are solved using numerical optimization software. The results obtained with the different models show that variables potentially important for safety systems, such as the yaw rate, slip angle, and geometric path, are qualitatively the same. Moreover, the numeric differences are mostly within a few percent. The results also indicate that although input torques differ about 50–100 % for certain parts of the maneuver between the most and least complex model considered, the resulting vehicle motions obtained are similar, irrespective of the model. Our main conclusion is that this enables the use of low-order models when designing the onboard optimization-based safety systems of the future. 1

An efficient pre-object collimator based on an x-ray lens

A multiprism lens (MPL) is a refractive x-ray lens with one-dimensional focusing properties. If used as a pre-object collimator in a scanning system for medical x-ray imaging, it reduces the divergence of the radiation and improves on photon economy compared to a slit collimator. Potential advantages include shorter acquisition times, a reduced tube loading, or improved resolution. We present the first images acquired with a MPL in a prototype for a scanning mammography system. The lens showed a gain of flux of 1.32 compared to a slit collimator at equal resolution, or a gain in resolution of 1.31–1.44 at equal flux. We expect the gain of flux in a clinical setup with an optimized MPL and a custom-made absorption filter to reach 1.67, or 1.45–1.54 gain in resolution.QC 20100713QC 20210105</p

Observer model optimization of a spectral mammography system

Spectral imaging is a method in medical x-ray imaging to extract information about the object constituents by the material-specific energy dependence of x-ray attenuation. Contrast-enhanced spectral imaging has been thoroughly investigated, but unenhanced imaging may be more useful because it comes as a bonus to the conventional non-energy-resolved absorption image at screening; there is no additional radiation dose and no need for contrast medium. We have used a previously developed theoretical framework and system model that include quantum and anatomical noise to characterize the performance of a photon-counting spectral mammography system with two energy bins for unenhanced imaging. The theoretical framework was validated with synthesized images. Optimal combination of the energy-resolved images for detecting large unenhanced tumors corresponded closely, but not exactly, to minimization of the anatomical noise, which is commonly referred to as energy subtraction. In that case, an ideal-observer detectability index could be improved close to 50% compared to absorption imaging. Optimization with respect to the signal-to-quantum-noise ratio, commonly referred to as energy weighting, deteriorated detectability. For small microcalcifications or tumors on uniform backgrounds, however, energy subtraction was suboptimal whereas energy weighting provided a minute improvement. The performance was largely independent of beam quality, detector energy resolution, and bin count fraction. It is clear that inclusion of anatomical noise and imaging task in spectral optimization may yield completely different results than an analysis based solely on quantum noise.QC 20110111</p

Energy resolution of a photon-counting silicon strip detector

A photon-counting silicon strip detector with two energy thresholds was investigated for spectral X-ray imaging in a mammography system. Preliminary studies already indicate clinical benefit of the detector, and the purpose of the present study is optimization with respect to energy resolution. Factors relevant for the energy response were measured, simulated, or gathered from previous studies, and used as input parameters to a cascaded detector model. Threshold scans over several X-ray spectra were used to calibrate threshold levels to energy, and to validate the model. The energy resolution of the detector assembly was assessed to range over ΔE/E=0.12–0.26 in the mammography region. Electronic noise dominated the peak broadening, followed by charge sharing between adjacent detector strips, and a channel-to-channel threshold spread. The energy resolution may be improved substantially if these effects are reduced to a minimum. Anti-coincidence logic mitigated double counting from charge sharing, but erased the energy resolution of all detected events, and optimization of the logic is desirable. Pile-up was found to be of minor importance at typical mammography rates.QC 20100714</p