13 research outputs found
Design concept for a collapsible stackable city car
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Architecture, 2009.Page 214 blank.Includes bibliographical references (p. 209-213).Problems associated with the massive adoption of automobiles have become the center of a world-wide debate. While new technologies will eventually discover a sustainable solution to the environmental concerns (pollution, depletion of energy sources), cities will continue struggling to accommodate the increasing number of cars. The ability for people to move quickly across large distances and the infrastructure required by the automobile (mainly roads and parking) have also created an unsustainable urban landscape in many countries. The argument of this work is that these problems are partly the result of an outdated set of design premises for the automobile which have not changed since it appeared in the late 1800's. A typical car is too big, too heavy, most of the times it only transports one person for a few miles, and then it remains unused for 95% of the time. These inefficiencies multiplied by the staggering number of vehicles in circulation have resulted in huge energy losses, pollution and vast portions of the city lost in support systems for the car. The work discussed here proposes a different approach to urban transportation, by combining the advantages of mass transit with the convenience of personal mobility. Instead of designing automobiles to fullfil any kind of travel need and additional parking structures destined to accommodate 85% of these automobiles, this work proposes a reconfiguration of the car based on the characteristics of the majority of vehicular urban travel.(cont.) The design of the car operates on a shared-ownership model, with a collapsible structure that allows vehicles to contract and park in stacks. Based on the available data, results indicate that such a design could potentially reduce the actual space requirements for a car between 1/20th and 1/75th. The design of the car is complemented by the use of electric in-wheel motors, developed in connection with the Smart Cities group run at the MIT Media Laboratory under the supervision of Professor Mitchell, for additional efficiency, especially in terms of energy consumption.by Fanceo Vairani.Ph.D
Cross-sectional study on the prevalence of contagious pathogens in bulk tank milk and their effects on somatic cell counts and milk yield
Data on the prevalence of major contagious pathogens in bulk tank milk (BTM) in Italy are generally not available. The availability of Real-Time PCR procedures (qPCR) to perform BTM analysis by represents an important step to define herd health status. Therefore, a cross-sectional epidemiological study was designed to assess the prevalence of contagious pathogens and Prototheca spp in BTM samples. The study was performed on 581 herds from four districts in the west Lombardy region of Italy. Additionally, the relationship between pathogens in BTM and SCC or milk yield; the presence of an association between four risk factors (district, herd size, average milk yield and SCC) with pathogens in BTM were assessed. The overall data showed that S. aureus was recovered in 42% of the herds, Str. agalactiae in 10%, Prototheca spp in 11% and M. bovis in 1.5% of the herds. The GLM model applied showed a significant influence of BTM results, district, herd size and their interactions on SCC and on milk yield variance. Particularly, S. aureus or Str. agalactiae have a significant effect on milk yield variability and, in a lesser extent, on SCC. The very high prevalence of contagious pathogens significantly affects milk characteristics and yield, thus affecting economic sustainability of the herds, and suggests the need to implement control programmes to decrease the prevalence of contagious pathogens, This will also allow to decrease the use of antimicrobials and to improve cow welfare
Differential Somatic Cell Count as a Marker for Changes of Milk Composition in Cows with Very Low Somatic Cell Count
The recent availability of a high-throughput milk analyzer performing a partial differential somatic cell count (DSCC) opened new opportunities in investigations on bovine udder health. This analyzer has a potential limitation on the accuracy of measurements when the somatic cell count (SCC) is below 50,000 cells/mL, values characterizing a good proportion of lactating cows in many herds. We obtained data for cows below this threshold, assessed the repeatability of these measurements and investigated the relationship between DSCC and udder health, milk composition and yield. Overall, 3022 cow milk test records performed on a Fossomatic™ 7/DC (Foss A/S, Hillerød, Denmark) were considered; 901 of them had an SCC ≤ 50,000 cells/mL. These latter samples were analyzed by qPCR to identify the presence of bacteria. Overall, 20.75% of the samples (187) were positive. However, the health status did not have any significant association with DSCC. The analysis of the association of DSCC on milk fat, protein and casein showed a significant decrease in their proportions as the DSCC increased, whereas it was not observed for milk yield and lactose. Therefore, DSCC in very low SCC cows may be suggested as a marker to identify early changes in milk composition
Assessment of subclinical mastitis diagnostic accuracy by differential cell count in individual cow milk
The progressive decrease of mean SCC in dairy herds worldwide is affecting SCC accuracy as a subclinical mastitis marker. This evidence supports studies aiming to apply differential cell count (DSCC) as a tool to identify mastitis. Two of the major obstacles to apply DSCC were the unavailability of high-throughput milk analysers and the cost of these analyses. Recently availability of high-throughput milk analysers, able to perform a partial DSCC on milk, allowed designing a study aiming to identify subclinical mastitis in individual milk samples. This paper reports the result of this first Italian study performed under field conditions. The study considered 4386 milk test records from four dairy herds with different size, management and milking management. DSCC data were analysed by ROC procedure. This procedure allows identifying the threshold giving the highest accuracy and the highest combined value for sensitivity and specificity, among all the possible thresholds. Among the different ways used to classify milk samples, the analysis applied to days in milk (three classes) showed the highest mean values for sensitivity plus specificity, and the value for accuracy was very close to the highest one observed. At the time of submission, this is the first paper available on peer-reviewed scientific journals reporting the evaluation of DSCC as a marker for subclinical mastitis on individual milk samples collected during routine milk test. The results will help the improvement of mastitis diagnosis and will help dairy farmers to increase the levels of herd management and efficiency.Highlights At the time of submission, this is the first paper available on peer-reviewed scientific journals on the evaluation of DSCC as a marker for subclinical mastitis on individual milk samples. The analysis of data showed as DSCC has not consistent performances, confirming the presence of confounding factors such as parity and days in milk. The thresholds calculated on samples classified by days in milk (three classes) showed to have the overall best test performances with an accuracy of 82.3%
Somatic Cell Count as a Decision Tool for Selective Dry Cow Therapy in Italy
The application of selective dry cow therapy is one of the measures currently suggested to reduce the use of antibiotics in dairy herds. However, the application of selective dry cow therapy will have a profound impact on Italian dairy herds, very likely affecting both milk yield and quality. Identifying cows to be treated at drying off is crucial for farmers and health authorities, therefore it is necessary the definition of a consistent and certified procedure. This article reports the results of a study aiming to identify which SCC threshold would be the most appropriate to identify cows to be treated and the potential consequences of different selection protocols on udder health after calving under field condition. Last milk test record before drying off and the average of lactation milk test records were considered on a database including 45,682 cow from 709 herd. Five different threshold were considered (50,000; 100,000; 150,000; 200,000; and 250,000 cells/mL). The statistical analysis of the database and a rational evaluation of the results suggest to define thresholds of 100,000 cells/mL for primiparous cows and 200,000 cells/mL for pluriparous cows measured either before drying-off or as the average of all the milk tests of the lactation. The criteria proposed will be useful to manage herd health and, specifically, dry-cows in an efficient and sustainable way, decreasing the use of antimicrobials without increasing the risk of affecting milk yield and quality after calvin
A systematic mapping review of the evolution of the rat Forced Swim Test: Protocols and outcome parameters
As depression is projected to become the leading mental disease burden globally by 2030, understanding the underlying pathology, as well as screening potential anti-depressants with a higher efficacy, faster onset of action, and/or fewer side-effects is essential. A commonly used test for screening novel antidepressants and studying depression-linked aspects in rodents is the Porsolt Forced Swim Test. The present systematic mappping review gives a comprehensive overview of the evolution and of the most prevalently used set-ups of this test in rats, including the choice of animals (strain, sex, and age), technical aspects of protocol and environment, as well as reported outcome measures. Additionally, we provide an accessible list of all existing publications, to support informed decision-making for procedural and technical aspects of the test, to thereby enhance reproducibility and comparability. This should further contribute to reducing the number of unnecessarily replicated experiments, and consequently, reduce the number of animals used in future
On the perception of computer-generated architectural representations
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Architecture, 2001.Includes bibliographical references (leaves 77-78).Representations of an architectural space have a diversity of purposes and their implementation should be carefully evaluated in order to be coherent with those objectives. Some of them are analytical descriptions, where its components are easily identifiable but relations among them may appear distorted to enhance a particular attribute. Methods used to represent a space, however, are also capable of a more expressive nature, as in art. Those expressions need not be an attempt to evoke the experience of the space in consideration, but just ideas the architect wants to share with his reality. The use of digital media allows incorporating time as another component to the spatial properties that static media has, expanding its possibilities both in terms of content as well as of form. This thesis suggests the use of diverse film theories as referential background for the creation of motion graphics, as a newly developed kind of architectural representations. Film theory and practice should help understand the implications of adding this other dimension to static images, as it resembles a proportional similarity to motion graphics. This does not imply that these two channels are the same or incomparably different. Hypothetically, there is a common field that brings them together and from which we can learn similarities as well as differences. A number of experiments were performed to test the validity of some of the notions expressed by several film theories in the realm of computer-generated motion graphics. A case study was selected to work with and a number of experiments would render several alternative representations of this particular architectural event, in this case, the church of Saint Pierre, in Firrniny, France, designed by Le Corbusier in 1962. They represented the same object, but these representations would have a completely different character and, arguably, might evoke a different reading of the space. These studies are an attempt to understand how to synthesize visually different ideas and convey distinct meanings to provoke the reading of the building in divergent directions.by Franco Vairani.S.M
Differential somatic cell count as a novel indicator of milk quality in dairy cows
Recent available instruments allow to record the number of differential somatic cell count (DSCC), representing the combined proportion of polymorphonuclear leukocytes and lymphocytes, on a large number of milk samples. Milk DSCC provides indirect information on the udder health status of dairy cows. However, literature is limited regarding the effect of DSCC on milk composition at the individual cow level, as well as its relation to the somatic cell score (SCS). Hence, the aims of this study were to (i) investigate the effect of different levels of DSCC on milk composition (fat, protein, casein, casein index, and lactose) and (ii) explore the combined effect of DSCC and SCS on these traits. Statistical models included the fixed effects of days in milk, parity, SCS, DSCC and the interaction between SCS Ă— DSCC, and the random effects of herd, animal within parity, and repeated measurements within cow. Results evidenced a decrease of milk fat and an increase in milk fatty acids at increasing DSCC levels, while protein, casein and their proportion showed their lowest values at the highest DSCC. A positive association was found between DSCC and lactose. The interaction between SCS and DSCC was important for lactose and casein index, as they varied differently upon high and low SCS and according to DSCC levels