Development of a Sandwich ELISA to Measure Exposure to Occupational Cow Hair Allergens

Background: Cow hair and dander are important inducers of occupational allergies in cattle-exposed farmers. To estimate allergen exposure in farming environments, a sensitive enzyme immunoassay was developed to measure cow hair allergens. Methods: A sandwich ELISA was developed using polyclonal rabbit antibodies against a mixture of hair extracts from different cattle breeds. To assess the specificity of the assay, extracts from other mammalian epithelia, mites, molds and grains were tested. To validate the new assay, cow hair allergens were measured in passive airborne dust samples from the stables and homes of farmers. Dust was collected with electrostatic dust fall collectors (EDCs). Results: The sandwich ELISA was found to be very sensitive (detection limit: 0.1 ng/ml) and highly reproducible, demonstrating intra-and interassay coefficients of variation of 4 and 10%, respectively. The assay showed no reactivity with mites, molds and grains, but some cross-reactivity with other mammalian epithelia, with the strongest reaction with goat. Using EDCs for dust sampling, high concentrations of bovine allergens were measured in cow stables (4,760-559,400 mu g/m(2)). In addition, bovine allergens were detected in all areas of cattle farmer dwellings. A large variation was found between individual samples (0.3-900 mu g/m(2)) and significantly higher values were discovered in changing rooms. Conclusion: The ELISA developed for the detection of cow hair proteins is a useful tool for allergen quantification in occupational and home environments. Based on its low detection limit, this test is sensitive enough to detect allergens in passive airborne dust. Copyright (C) 2011 S. Karger AG, Base

Chronic Lung Function Decline in Cotton Textile Workers: Roles of Historical and Recent Exposures to Endotoxin

BackgroundLong-term occupational exposure to cotton dust that contains endotoxin is associated with chronic respiratory symptoms and excessive decline in forced expiratory volume in 1 sec (FEV1), but the mechanisms of endotoxin-related chronic airflow obstruction remain unclear.ObjectiveIn the current study, we examined temporal aspects of the exposure-response relationship between airborne endotoxin exposure, longitudinal change in FEV1, and respiratory symptoms in a cohort of Chinese cotton textile workers.MethodsThis prospective cohort study followed 447 cotton textile workers from 1981 to 2006. at approximately 5-year intervals. We used a generalized estimating equations approach to model FEV1 level and respiratory symptoms as a function of past exposure (cumulative exposure up to the start of the most recent 5-year survey interval) and cumulative exposure (within the most recent interval) to endotoxins, after adjusting for other covariates. Models were stratified by active versus retired work status and by years employed before the baseline survey (< 5 and > or = 5 years).Results and conclusionsPast exposure to endotoxin was associated with reduced FEV1 level among retired cotton workers. Among all cotton workers, past exposure was more strongly associated with reduced FEV1 for those hired < 5 years before baseline than for those who were hired > or = 5 years after baseline. Recent endotoxin exposure was significantly associated with byssinosis, chronic bronchitis, and chronic cough

Asthma in changing environments - chances and challenges of international research collaborations between South America and Europe - study protocol and description of the data acquisition of a case-control-study

<p>Abstract</p> <p>Background</p> <p>Asthma in children is an emerging public health problem in South America. So far, research in this part of the world is limited. This paper presents the methodology and description of the data acquisition of an asthma case-control study conducted in the Central South of Chile.</p> <p>Methods/Design</p> <p>A hospital-based case-control study about asthma (188 cases, 294 controls) in children (6-15 years) was carried out in Valdivia, Chile between November 2008 and December 2009. Data on asthma risk factors were collected by computer-assisted personal interview using validated questions from e.g. ISAAC phase II. Data on household dust exposure (endotoxin, allergen analyses), skin prick tests to most common allergens, stool examinations for parasitic infection, and blood samples (total IgE, genetics) were collected. Additionally, 492 randomly chosen blood donors were recruited in order to assess allele frequencies in the population of Valdivia.</p> <p>Discussion</p> <p>Overall 1,173 participants were contacted. Response was 82% among cases and 65% among controls. Atopic sensitization was high (78% among cases, 47% among controls). Cases had a statistically significantly (p < .0001) increased self-reported 12-month prevalence of symptoms of rhinitis (82% vs. 51%) and wheeze (68% vs. 16%). The study is well placed to address current hypotheses about asthma and its correlates in the South American context. Results of this study might help develop novel, innovative and individualized prevention strategies in countries in transition with respect to the South American context.</p

Transport and signaling of SVC in IP networks

The transport of scalable media, and in particular of scalable video conforming to the forthcoming Scalable Video Coding (SVC) technology, presents challenges not only in the video compression technology, but also in transport and signaling. This paper discusses the current status of standardization of the support for scalable media, and SVC in particular, over IP based networks. Both the transport of SVC over the Real-time Transport Protocol (RTP), and the signaling support-namely the additional mechanisms in the Session Description Protocol (SDP)-are covered. As it turns out, the support of SVC over RTP is not quite as straightforward as that of nonscalable video bit streams. Specifically, the signaling architecture requires an almost complete overhaul, and new protocol mechanisms need to be introduced into the packetization

Subcode-Based Early HARQ for 5G

Tactile Internet (TI) constitutes one of the major use cases for the development of the fifth generation (5G) mobile specification. TI services put high demand on the latency and reliability requirement, which is covered in the ultra-reliable low-latency communication (URLLC) discussion in 5G standardization. Hybrid Automatic Repeat Request (HARQ) is used in LTE to achieve high robustness in an efficient way with the cost of introducing additional latency. In this paper, we propose a new early HARQ scheme based on LDPC subcodes (SC E- HARQ), which enables to provide faster feedback and thus an earlier retransmission. The SC E-HARQ technique makes use of substructures in LDPC codes to start feedback calculation already on partially received codewords. This paper investigates the performance of SC E-HARQ in comparison with a second E-HARQ scheme based on log-likelihood ratio (LLR) estimation. The results show that SC E-HARQ achieves a comparable reliability to regular HARQ. In SNR regions relevant for URLLC, it clearly outperforms also the LLR-based E-HARQ in means of reliability as well as latency. Sub-millisecond latency with a total block error rate (BLER) of less than 10 -4 is attained in TDL-C by allowing 1% false negative retransmissions

Hybrid video object tracking in H.265/HEVC video streams

In this paper we propose a hybrid tracking method which detects moving objects in videos compressed according to H.265/HEVC standard. Our framework largely depends on motion vectors (MV) and block types obtained by partially decoding the video bitstream and occasionally uses pixel domain information to distinguish between two objects. The compressed domain method is based on a Markov Random Field (MRF) model that captures spatial and temporal coherence of the moving object and is updated on a frame-to-frame basis. The hybrid nature of our approach stems from the usage of a pixel domain method that extracts the color information from the fully-decoded I frames and is updated only after completion of each Group-of-Pictures (GOP). We test the tracking accuracy of our method using standard video sequences and show that our hybrid framework provides better tracking accuracy than a state-of-the-art MRF model

Low latency DASH based streaming over LTE

Dynamic Adaptive Streaming over HTTP (DASH) is becoming the de facto technique for video delivery, especially for VoD services. Although 3GPP has specified carriage of DASH over eMBMS for Live Streaming, eMBMS is not available everywhere (operators are starting service rollout) and it is only worthwhile for reasonably large number of users due to the static SFN resource allocation for those services. Thus, Live Streaming using DASH over unicast connections is still necessary, which may suffer from playback interruptions when the throughput varies since the low end-to-end latency for live streaming requires small buffers. In order to cope with network throughput variations in mobile networks, we propose the usage of scalable video coding, combining it with parallel TCP connections and prioritizing the most important data of the scalable video. We show that using LTE non-GBR bearers for prioritization playback interruptions can be avoided