Cutting the Error by Half: Investigation of Very Deep CNN and Advanced Training Strategies for Document Image Classification

We present an exhaustive investigation of recent Deep Learning architectures, algorithms, and strategies for the task of document image classification to finally reduce the error by more than half. Existing approaches, such as the DeepDocClassifier, apply standard Convolutional Network architectures with transfer learning from the object recognition domain. The contribution of the paper is threefold: First, it investigates recently introduced very deep neural network architectures (GoogLeNet, VGG, ResNet) using transfer learning (from real images). Second, it proposes transfer learning from a huge set of document images, i.e. 400,000 documents. Third, it analyzes the impact of the amount of training data (document images) and other parameters to the classification abilities. We use two datasets, the Tobacco-3482 and the large-scale RVL-CDIP dataset. We achieve an accuracy of 91.13% for the Tobacco-3482 dataset while earlier approaches reach only 77.6%. Thus, a relative error reduction of more than 60% is achieved. For the large dataset RVL-CDIP, an accuracy of 90.97% is achieved, corresponding to a relative error reduction of 11.5%

DjinniChip: evaluation of a novel molecular rapid diagnostic device for the detection of Chlamydia trachomatis in trachoma-endemic areas.

BACKGROUND: The clinical signs of active trachoma are often present in the absence of ocular Chlamydia trachomatis infection, particularly following mass drug administration. Treatment decisions following impact surveys and in post-control surveillance for communities are currently based on the prevalence of clinical signs, which may result in further unnecessary distribution of mass antibiotic treatment and the increased spread of macrolide resistance alleles in 'off-target' bacterial species. We therefore developed a simple, fast, low cost diagnostic assay (DjinniChip) for diagnosis of ocular C. trachomatis for use by trachoma control programmes. METHODS: The study was conducted in the UK, Germany and Tanzania. For clinical testing in Tanzania, specimens from a sample of 350 children between the ages of 7 to 15 years, which were part of a longitudinal cohort that began in February 2012 were selected. Two ocular swabs were taken from the right eye. The second swab was collected dry, kept cool in the field and archived at - 80 °C before sample lysis for DjinniChip detection and parallel nucleic acid purification and detection/quantification by qPCR assay. RESULTS: DjinniChip was able to reliably detect > 10 copies of C. trachomatis per test and correctly identified 7/10 Quality Control for Molecular Diagnostics C. trachomatis panel samples, failing to detect 3 positive samples with genome equivalent amounts ≤ 10 copies. DjinniChip performed well across a range of typical trachoma field conditions and when used by lay personnel using a series of mock samples. In the laboratory in Tanzania, using clinical samples the sensitivity and specificity of DjinniChip for C. trachomatis was 66% (95% CI 51-78) and 94.8 (95% CI 91-97%) with an overall accuracy of 90.1 (95% CI 86.4-93). CONCLUSIONS: DjinniChip performance is extremely promising, particularly its ability to detect low concentrations of C. trachomatis and its usability in field conditions. The DjinniChip requires further development to reduce inhibition and advance toward a closed system. DjinniChip results did not vary between local laboratory results and typical trachoma field settings, illustrating its potential for use in low-resource areas to prevent unnecessary rounds of MDA and to monitor for C. trachomatis recrudescence

Apolipoprotein E-dependent load of white matter hyperintensities in Alzheimer’s disease: a voxel-based lesion mapping study

Introduction: White matter (WM) magnetic resonance imaging (MRI) hyperintensities are common in Alzheimer’s disease (AD), but their pathophysiological relevance and relationship to genetic factors are unclear. In the present study, we investigated potential apolipoprotein E (APOE)-dependent effects on the extent and cognitive impact of WM hyperintensities in patients with AD. Methods: WM hyperintensity volume on fluid-attenuated inversion recovery images of 201 patients with AD (128 carriers and 73 non-carriers of the APOE ε4 risk allele) was determined globally as well as regionally with voxel-based lesion mapping. Clinical, neuropsychological and MRI data were collected from prospective multicenter trials conducted by the German Dementia Competence Network. Results: WM hyperintensity volume was significantly greater in non-carriers of the APOE ε4 allele. Lesion distribution was similar among ε4 carriers and non-carriers. Only ε4 non-carriers showed a correlation between lesion volume and cognitive performance. Conclusion: The current findings indicate an increased prevalence of WM hyperintensities in non-carriers compared with carriers of the APOE ε4 allele among patients with AD. This is consistent with a possibly more pronounced contribution of heterogeneous vascular risk factors to WM damage and cognitive impairment in patients with AD without APOE ε4-mediated risk

The spinal cord injury-induced immune deficiency syndrome: results of the SCIentinel study

Infections are prevalent after spinal cord injury (SCI), constitute the main cause of death and are a rehabilitation confounder associated with impaired recovery. We hypothesize that SCI causes an acquired lesion-dependent (neurogenic) immune suppression as an underlying mechanism to facilitate infections. The international prospective multicentre cohort study (SCIentinel; protocol registration DRKS00000122; n = 111 patients) was designed to distinguish neurogenic from general trauma-related effects on the immune system. Therefore, SCI patient groups differing by neurological level, i.e. high SCI [thoracic (Th)4 or higher]; low SCI (Th5 or lower) and severity (complete SCI; incomplete SCI), were compared with a reference group of vertebral fracture (VF) patients without SCI. The primary outcome was quantitative monocytic Human Leukocyte Antigen-DR expression (mHLA-DR, synonym MHC II), a validated marker for immune suppression in critically ill patients associated with infection susceptibility. mHLA-DR was assessed from Day 1 to 10 weeks after injury by applying standardized flow cytometry procedures. Secondary outcomes were leucocyte subpopulation counts, serum immunoglobulin levels and clinically defined infections. Linear mixed models with multiple imputation were applied to evaluate group differences of logarithmic-transformed parameters. Mean quantitative mHLA-DR [ln (antibodies/cell)] levels at the primary end point 84 h after injury indicated an immune suppressive state below the normative values of 9.62 in all groups, which further differed in its dimension by neurological level: high SCI [8.95 (98.3% confidence interval, CI: 8.63; 9.26), n = 41], low SCI [9.05 (98.3% CI: 8.73; 9.36), n = 29], and VF without SCI [9.25 (98.3% CI: 8.97; 9.53), n = 41, P = 0.003]. Post hoc analysis accounting for SCI severity revealed the strongest mHLA-DR decrease [8.79 (95% CI: 8.50; 9.08)] in the complete, high SCI group, further demonstrating delayed mHLA-DR recovery [9.08 (95% CI: 8.82; 9.38)] and showing a difference from the VF controls of -0.43 (95% CI: -0.66; -0.20) at 14 days. Complete, high SCI patients also revealed constantly lower serum immunoglobulin G [-0.27 (95% CI: -0.45; -0.10)] and immunoglobulin A [-0.25 (95% CI: -0.49; -0.01)] levels [ln (g/l × 1000)] up to 10 weeks after injury. Low mHLA-DR levels in the range of borderline immunoparalysis (below 9.21) were positively associated with the occurrence and earlier onset of infections, which is consistent with results from studies on stroke or major surgery. Spinal cord injured patients can acquire a secondary, neurogenic immune deficiency syndrome characterized by reduced mHLA-DR expression and relative hypogammaglobulinaemia (combined cellular and humoral immune deficiency). mHLA-DR expression provides a basis to stratify infection-risk in patients with SCI

Airflow through lightweight wall assemblies - influence of size and location of leakages

Compared to the overall building envelope airtightness concerning energetic aspects, the condensation caused by air exfiltration is still a challenge today. For a better understanding of the processes inside lightweight constructions, hot-and cold-box experiments and airflow measurements on 14 different full-scale wall assemblies under realistic climatic conditions were performed. The influences of different mineral wool airflow permeabilities and leak configurations, as well as different pressure differences were analyzed. Despite a certain level of uncertainty, the results show some interesting aspects about the influencing factors of the convective moisture entry. The distributions of the water content between sheathing and insulation samples show that more water remains inside the mineral wool with low air permeability, while in case of the more air permeable mineral wool, more water accumulates in the sheathing. Moreover, the findings indicate that the moisture distribution over the height of the sheathing is more influenced by the pressure difference level than by insulation air permeability or arrangements of the small openings. For the tested configurations, a lateral flow due to openings near the studs shows the highest total moisture contents inside the assemblies. In contrast, we could not observe significant differences concerning the moisture content for the different leak arrangements and diameters with the same total leakage area under humidification test conditions, although differences in the flow behavior are clearly detected. However, another important finding of these experiments is that, despite good workmanship, a small amount of air and moisture seams to penetrate the sealing tape joints