150 research outputs found
Improving Access to E-Journals and Databases at the MIT Libraries: Building a Database-Backed Web Site Called "Vera"
Co published simultaneously in The Serials Librarian, Vol. 41, no. 3/4, 2002, pp. 227-254; and: E-Serials Cataloging: Access to Continuing and Integrating Resources via the Catalog and the Web, ed. by Jim Cole and Wayne Jones, The Haworth Information Press, 2002, pp. 227-254. [PDF version of entire journal issue available for free from Hayworth Press]. HTML version available at The MIT Libraries provide access to databases and electronic journals via the online catalog and the web. The Vera database was created in order to improve public access to a growing number of resources listed on web pages and also to help the staff more easily maintain these pages. Details of the database, called "Vera" (Virtual Electronic Resource Access), are described, including field definitions and how the database is used by both staff and public. The development of the database helped to improve access and made it easier to maintain a growing number of resources. It has also led to many further questions and discussions among the staff of the MIT Libraries about the scope of the OPAC and how tools like Vera should be related to it
When a Librarian's Not There to Ask: Creating an Information Resource Advisory Tool
It is 2am. A professor wakes up with a new direction for her research; she must immediately learn about bioethics. In a dorm a student is finally ready to begin a paper on Cuba. Where do they turn? The library web site presents them with a bewildering array of resources and no librarian on hand to serve as intermediary. How can librarians facilitate research in their absence? What interfaces can be designed to educate users in their search? What metadata is needed to enable accurate retrieval? What is the librarianâs role in the increasingly indirectly-mediated information-seeking environment? Can the reference interview be effectively translated into a search interface? This paper describes a step towards resolving these issues by creating an on-line tool to assist users in selecting the database(s) most germane to their research needs
From Stable to LabâInvestigating Key Factors for Sudden Deaths Caused by Streptococcus suis
Swine stocks are endemically infected with the major porcine pathogen Streptococcus (S.)
suis. The factors governing the transition from colonizing S. suis residing in the tonsils and the
exacerbation of disease have not yet been elucidated. We analyzed the sudden death of fattening
pigs kept under extensive husbandry conditions in a zoo. The animals died suddenly of septic shock
and showed disseminated intravascular coagulopathy. Genotypic and phenotypic characterizations
of the isolated S. suis strains, a tonsillar isolate and an invasive cps type 2 strain, were conducted.
Isolated S. suis from dead pigs belonged to cps type 2 strain ST28, whereas one tonsillar S. suis
isolate harvested from a healthy animal belonged to ST1173. Neither S. suis growth, induction of
neutrophil extracellular traps, nor survival in blood could explain the sudden deaths. Reconstituted
blood assays with serum samples from pigs of different age groups from the zoo stock suggested
varying protection of individuals against pathogenic cps type 2 strains especially in younger pigs.
These findings highlight the benefit of further characterization of the causative strains in each case by
sequence typing before autologous vaccine candidate selection
User Needs Assessment of Information Seeking Activities of MIT Students - Spring 2006
The SFX/Verde Group was authorized to complete a user needs assessment in the form of a Photo Diary Study with MIT students in the spring of 2006. The goal of the study was to inform the MIT Libraries of online tool improvements that should be implemented to meet our most pressing user needs. Sixteen graduate students and sixteen undergraduate students participated in offering a fascinating glimpse into the information-seeking aspects of their academic lives.
The team categorized user behaviors into goals and tasks and then analyzed the 277 goals and tasks and the 507 methods shared with us by the students in the study. The study yielded the following priorities for the Libraries' online tools:
Make discovery easier and more effective.
Incorporate trusted networks in finding tools.
Continue to put links to the Libraries' services and resources where the users are.
The study also showed that the students used a variety of highly successful strategies for performing quick lookups of information and finding specific known items. Finally, while the assessment focused on aspects of the students' work related to online tools, it also yielded rich information that could be useful in improving other aspects of the Libraries' services
Effects of Mesenchymal Stem Cell and Growth Factor Delivery on Cartilage Repair in a Mini-Pig Model
Objective We have recently shown that mesenchymal stem cells (MSCs) embedded in a hyaluronic acid (HA) hydrogel and exposed to chondrogenic factors (transforming growth factor-3 [TGF-3]) produce a cartilage-like tissue in vitro. The current objective was to determine if these same factors could be combined immediately prior to implantation to induce a superior healing response in vivo relative to the hydrogel alone. Design Trochlear chondral defects were created in Yucatan mini-pigs (6 months old). Treatment groups included an HA hydrogel alone and hydrogels containing allogeneic MSCs, TGF-3, or both. Six weeks after surgery, micro-computed tomography was used to quantitatively assess defect fill and subchondral bone remodeling. The quality of cartilage repair was assessed using the ICRS-II histological scoring system and immunohistochemistry for type II collagen. Results Treatment with TGF-3 led to a marked increase in positive staining for collagen type II within defects (P 0.05). Neither condition had an impact on other histological semiquantitative scores (P > 0.05), and inclusion of MSCs led to significantly less defect fill (P 0.05). Conclusions At this early healing time point, treatment with TGF-3 promoted the formation of collagen type II within the defect, while allogeneic MSCs had little benefit. Combination of TGF-3 and MSCs at the time of surgery did not produce a synergistic effect. An in vitro precultured construct made of these components may be required to enhance in vivo repair in this model system
Fogging low concentrated organic acid in a fattening pig unit â Effect on animal health and microclimate
Introduction and objective
In intensive pig production aerial contaminates are potential hazards for the health of animals and humans. In this study, the effect of fogging a low concentrated tartaric acid solution on pigsâ health, environmental and hygiene parameters were evaluated in an inhabited fattening unit.
Material and Methods
Pigs were housed in separate units (control group n=109 and experimental group n=110). During the whole fattening period, twice a week at 48 hour intervals, a 0.1% tartaric acid solution was aerosolized by a cold-fogging system for 20 minutes in the experimental unit. Environmental parameters were spot-checked on days of fogging. Sedimentation dust and surfaces were analysed for bacterial and fungal load. Dust particle size distribution was assessed. Pigs were clinically examined weekly. Standard meat examination at an abattoir was extended by individual quantification of lung alterations.
Results
The fogging procedure had no influence on ammonia concentrations. A significant reduction of mould, but not of bacteria, was found in sedimentation dust, and bacterial and mould scores of surface samples were improved. A significant reduction of particle size classes 1.6â2.0 ”m, 4.0â5.0 ”m, 7.5â10 ”m, as well as 10â15 ”m was observed. The high sound level of the fogging machine (82â102 dB) led to higher activity and pen-mate directed behaviour. More skin alterations, conjunctivitis and sneezing were recorded in the experimental group. Gross pathological lung alterations did not differ between both groups.
Conclusions
Although fogging of tartaric acid is limited to a concentration of 0.1% due to its irritating effect on the respiratory mucosa, reduction of microbial load can be achieved, but it would be enhanced by using more powerful fogging systems
Impact of bronchoalveolar lavage from influenza A virus diseased pigs on neutrophil functions and growth of co-infecting pathogenic bacteria
IntroductionInfluenza A viruses (IAVs) infect the respiratory tract of mainly humans, poultry, and pigs. Co-infections with pathogenic lung bacteria are a common event and contribute to the severity of disease progression. Neutrophils are a major cell type of the innate immune system and are rapidly recruited to the site of infection. They have several effector functions to fight invading pathogens such as the secretion of reactive oxygen species (ROS) or the release of neutrophil extracellular traps (NETs). NETs are known to promote the growth of Pasteurellaceae bacteria, especially if degraded by nucleases.MethodsIn this study, bronchoalveolar lavage fluid (BALF) from 45 field-infected pigs was analyzed for 1) NET markers, 2) influence on growth of lung bacteria, and 3) impact on neutrophil functions. BALF samples from 21 IAV-positive pigs and 24 lung diseased but IAV-negative pigs were compared.ResultsHere, we show that neutrophils in the lungs of IAV-positive pigs release vesicular NETs. Several NET markers were increased in the BALF of IAV-positive pigs compared with the BALF from IAV-negative pigs. The amount of NET markers positively correlated with the viral load of the IAV infection. Interestingly, the BALF of IAV-positive pigs enhanced the growth of bacteria belonging to the family of Pasteurellaceae as potential coinfecting bacteria. These effects were weaker with the BALF derived from IAV-negative pigs with other lung infections. The intensity of oxidative burst in neutrophils was significantly decreased by BALF from IAVpositive pigs, indicating impaired antimicrobial activity of neutrophils. Finally, the lung milieu reflected by IAV-positive BALF does not enable neutrophils to kill Actinobacillus pleuropneumoniae but rather enhances its growth.DiscussionIn summary, our data show that an IAV infection is affecting neutrophil functions, in particular the release of NETs and ROS. Furthermore, IAV infection seems to provide growth-enhancing factors for especially coinfecting Pasteurellaceae and reduces the killing efficiency of neutrophils
Mucosal prior to systemic application of recombinant adenovirus boosting is more immunogenic than systemic application twice but confers similar protection against SIV-challenge in DNA vaccine-primed macaques
AbstractWe investigated the immunogenicity and efficacy of a bimodal prime/boost vaccine regimen given by various routes in the Simian immunodeficiency virus (SIV) rhesus monkey model for AIDS. Twelve animals were immunized with SIV DNA-vectors followed by the application of a recombinant adenovirus (rAd5) expressing the same genes either intramuscularly (i.m.) or by oropharyngeal spray. The second rAd5-application was given i.m. All vaccinees plus six controls were challenged orally with SIVmac239 12Â weeks post-final immunization.Both immunization strategies induced strong SIV Gag-specific IFN-Îł and T-cell proliferation responses and mediated a conservation of CD4+ memory T-cells and a reduction of viral load during peak viremia following infection. Interestingly, the mucosal group was superior to the systemic group regarding breadth and strength of SIV-specific T-cell responses and exhibited lower vector specific immune responses. Therefore, our data warrant the inclusion of mucosal vector application in a vaccination regimen which makes it less invasive and easier to apply
Macrophage- and CD4+ T cell-derived SIV differ in glycosylation, infectivity and neutralization sensitivity
The human immunodeficiency virus (HIV) envelope protein (Env) mediates viral entry into host cells and is the primary target for the humoral immune response. Env is extensively glycosylated, and these glycans shield underlying epitopes from neutralizing antibodies. The glycosylation of Env is influenced by the type of host cell in which the virus is produced. Thus, HIV is distinctly glycosylated by CD4+ T cells, the major target cells, and macrophages. However, the specific differences in glycosylation between viruses produced in these cell types have not been explored at the molecular level. Moreover, it remains unclear whether the production of HIV in CD4+ T cells or macrophages affects the efficiency of viral spread and resistance to neutralization. To address these questions, we employed the simian immunodeficiency virus (SIV) model. Glycan analysis implied higher relative levels of oligomannose-type N-glycans in SIV from CD4+ T cells (T-SIV) compared to SIV from macrophages (M-SIV), and the complex-type N-glycans profiles seem to differ between the two viruses. Notably, M-SIV demonstrated greater infectivity than T-SIV, even when accounting for Env incorporation, suggesting that host cell-dependent factors influence infectivity. Further, M-SIV was more efficiently disseminated by HIV binding cellular lectins. We also evaluated the influence of cell type-dependent differences on SIVâs vulnerability to carbohydrate binding agents (CBAs) and neutralizing antibodies. T-SIV demonstrated greater susceptibility to mannose-specific CBAs, possibly due to its elevated expression of oligomannose-type N-glycans. In contrast, M-SIV exhibited higher susceptibility to neutralizing sera in comparison to T-SIV. These findings underscore the importance of host cell-dependent attributes of SIV, such as glycosylation, in shaping both infectivity and the potential effectiveness of intervention strategies
- âŠ