Taking the Lab to the Field: Experimental Tests of Alternative Mechanisms to Procure Multiple Contracts

The first part of the paper reports the results from a sequence of laboratory experiments comparing the bidding behavior for multiple contracts in three different sealed bid auction mechanisms; first-price simultaneous, first-price sequential and first-price combinatorial bidding. The design of the experiment is based on experiences from a public procurement auction of road markings in Sweden. Bidders are asymmetric in their cost functions; some exhibit decreasing average costs of winning more than one contract, whereas other bidders have increasing average cost functions. The combinatorial bidding mechanism is demonstrated to be most efficient. The second part of the paper describes how the lab experiment was followed up by a field test of a combinatorial procurement auction of road markings.Multiple units, non-constant costs, asymmetric redemption values, alternative procurement mechanisms

10-year survival of total ankle arthroplasties: A report on 780 cases from the Swedish Ankle Register

Background and purpose There is an ongoing need to review large series of total ankle replacements (TARs) for monitoring of changes in practice and their outcome. 4 national registries, including the Swedish Ankle Register, have previously reported their 5-year results. We now present an extended series with a longer follow-up, and with a 10-year survival analysis. Patients and methods Records of uncemented 3-component TARs were retrospectively reviewed, determining risk factors such as age, sex, and diagnosis. Prosthetic survival rates were calculated with exchange or removal of components as endpoint-excluding incidental exchange of the polyethylene meniscus. Results Of the 780 prostheses implanted since 1993, 168 (22%) had been revised by June 15, 2010. The overall survival rate fell from 0.81 (95% CI: 0.79-0.83) at 5 years to 0.69 (95% CI: 0.67-0.71) at 10 years. The survival rate was higher, although not statistically significantly so, during the latter part of the period investigated. Excluding the STAR prosthesis, the survival rate for all the remaining designs was 0.78 at 10 years. Women below the age of 60 with osteoarthritis were at a higher risk of revision, but age did not influence the outcome in men or women with rheumatoid arthritis. Revisions due to technical mistakes at the index surgery and instability were undertaken earlier than revisions for other reasons. Interpretation The results have slowly improved during the 18-year period investigated. However, we do not believe that the survival rates of ankle replacements in the near future will approach those of hip and knee replacements-even though improved instrumentation and design of the prostheses, together with better patient selection, will presumably give better results

Kravnivåer för energihushållning - Konsekvenser av skärpning av krav för energihushållning i revidering av byggregler

Miljö- och samhällsbyggnadsdepartementet har uppdragit åt Chalmers EnergiCentrum (CEC) att analysera konsekvenserna av en eventuell skärpning av kravnivåerna avseende energihushållning i avsnitt 9 om Energihushållning i Boverkets förslag till reviderade byggregler. Uppdraget skall belysa dessa frågor: • Hur energieffektivt byggs det idag uppdelat i småhus, flerbostadshus och lokaler? • Vad är tekniskt möjligt och vilka tekniska lösningar krävs det för att komma ner till en viss nivå i kWh/m2? • Hur påverkar en skärpning av kravnivåerna elbehovet? • Vilka samhällsekonomiska konsekvenser för en eventuell skärpning av kravnivåerna med sig? En sammanvägd analys skall göras av vilka krav på energihushållning som är rimliga att ställa vid nybyggnad utifrån tekniska och samhällsekonomiska aspekter, och om kraven bör formuleras olika för olika byggnadskategorier. I uppdraget ingår också en analys av i Ds 2005:51 föreslaget mål om energieffektivisering i bebyggelsen utifrån potentialbedömningen i Chalmers rapport Åtgärder för ökad energieffektivisering i bebyggelsen. Uppdraget har utförts under tiden från mitten av december 2005 till 2006-01-10. Uppdragets begränsade tid och omfattning innebär att de aktuella frågorna inte kunnat belysas i detalj, utan de behandlas mer översiktligt och baserat på den kunskap som finns tillgänglig

Oestradiol levels and superoxide dismutase activity in age-related cataract: a case-control study.

Background: It has been suggested that the higher prevalence of cataract in women is caused by a withdrawal effect of oestrogen at menopause. In vitro studies have demonstrated protection of serum oestradiol (E2) against oxidative stress through upregulation of antioxidant enzymes, including superoxide dismutase (SOD). The purpose of the present study was to investigate E2 levels and SOD erythrocyte activity in patients with age-related cataract. Methods: The studied subjects consisted of 103 patients with age-related cataract and 22 controls. Cataracts were classified as nuclear, cortical, or posterior subcapsular. Blood samples were collected and data on smoking, hormonal use, diabetes and age at menarche/menopause was obtained for all individuals. Serum oestradiol analyses were performed with radioimmunoassay (RIA) and SOD activity was measured in erythrocyte lysates. Results: A negative correlation between age and E2 concentration was seen in a linear regression analysis. No correlation was seen between SOD activity and age or gender and no correlation between E2 levels and SOD activity was found using multiple linear regression. The mean level of E2 for all male subjects was 50.1 +/- 16.3 pmol/L, significantly higher compared to 13.8 +/- 11.8 pmol/L for postmenopausal women. Conclusion: The present study does not support a role for E2-induced effects on SOD in cataract formation. The findings of higher E2 levels in men than in postmenopausal women may suggest that decreased oestrogen at menopause is partially responsible for the gender-related difference in cataract prevalence. However, the latter can only be verified through prospective randomized trials using hormonal replacement therapy

Poor prosthesis survival and function after component exchange of total ankle prostheses

BACKGROUND AND PURPOSE: In failed total ankle replacements (TARs), fusion is often the procedure of preference; the outcome after exchanging prosthetic components is debated. We analyzed prosthetic survival, self-reported function, and patient satisfaction after component exchange. Patients and methods We identified patients in the Swedish Ankle Registry who underwent exchange of a tibial and/or talar component between January 1, 1993 and July 1, 2013 and estimated prosthetic survival by Kaplan-Meier analysis. We evaluated the patient-reported outcome measures (PROMs) SEFAS, EQ-5D, EQ-VAS, SF-36, and patient satisfaction by direct questions.RESULTS: 69 patients underwent revision TAR median 22 (0-110) months after the primary procedure. 24 of these failed again after median 26 (1-110) months. Survival analysis of revision TAR showed a 5-year survival rate of 76% and a 10-year survival of 55%. 29 patients with first revision TAR in situ answered the PROMs at mean 8 (1-17) years after revision and had the following mean scores: SEFAS 22, SF-36 physical 37 and mental 49, EQ-5D index 0.6, and EQ-VAS 64. 15 of the patients were satisfied, 5 were neither satisfied nor dissatisfied, and 9 were dissatisfied.INTERPRETATION: Revision TAR had a 10-year survival of 55%, which is lower than the 10-year survival of 74% for primary TAR reported from the same registry. Only half of the patients were satisfied. Future studies should show which, if any, patients benefit from revision TAR and which patients should rather be fused directly

The Intratumoral Distribution of Radiolabeled 177Lu-BR96 Monoclonal Antibodies Changes in Relation to Tumor Histology over Time in a Syngeneic Rat Colon Carcinoma Model.

The therapeutic effect of radioimmunotherapy depends on the distribution of the absorbed dose in relation to viable cancer cells within the tumor, which in turn is a function of the activity distribution. The aim of this study was to investigate the distribution of (177)Lu-DOTA-BR96 monoclonal antibodies targeting the Lewis Y antigen over 7 d using a syngeneic rat model of colon carcinoma

La Piezosurgery come metodica alternativa alla strumentazione rotante tradizionale nell'estrazione di ottavi inferiori inclusi. Revisione della letteratura

La presente dissertazione si occupa di esporre la validità della piezosurgery nell'estrazione di ottavi inclusi inferiori come alternativa alla strumentazione rotante tradizionale. Ne vengono illustrati vantaggi e svantaggi con particolare attenzione al tempo impiegato per l'intervento, alla riduzione delle complicanze e al miglioramento del decorso postoperatorio, il tutto sulla base di una revisione sistematica che la letteratura propone su questo argomento corredata dall' esposizione di una serie di casi clinici

How and why acoustic detectability and catchability of herring change with individual motivation and physiological state in a variable environment: a multi-scale study on a local herring population in southwestern Norway

The understanding of distribution and aggregation in herring (Clupea harengus) can be enhanced by integrated multi-scale studies in small ecosystems. Hydro-acoustics, underwater cameras, herring and predator gillnet samples and oceanographical measurements were used to quantify herring schooling dynamics. During autumn (September) after an active feeding period, the herring was distributed in small and dense schools, mostly close to land and in relatively shallow water ( 40 m depth). All recorded herring schools were then vertically extended in the water column within the most variable temperature and oxygen profiles, presumably enabling individuals to adjust maturation rate to prevailing environmental conditions and synchronize spawning of individuals within the school. From late February prior to spawning, only one major pelagic school was observed, extraordinarily stationary at the only inlet to the inner basin. The pre-spawning herring aggregation was fairly easy to detect acoustically for more than one month. Just prior to spawning and during spawning, herring spread out and became extremely difficult to detect acoustically. Only underwater cameras and bottom set gillnets could then be used to identify herring and selected spawning areas. We argue that the dramatic seasonal changes in acoustic detectability and catchability we observe is best understood and predicted based on detailed knowledge of how herring react to a changing environment according to their physiological state and motivation. Such factors should also be taken more systematically into account when performing acoustic surveys in large marine ecosystems. We need to study in more detail the vital underlying processes behind the substantial variability observed in acoustic detectability and catchability of pelagic planktivorous fish species during their annual life cycle in order to better understand and quantify variability in acoustic surveys, and thereby improve our acoustic abundance estimation