1,073 research outputs found
Privacy-preserving Twitter-based solution for visually impaired people
Visually impaired people is a big community all over the world. They usually seek help to perform their daily activities such as reading the expired date of food cans or medicine, reading out PIN of a certain ATM Visa, identifying the color of clothes or differentiate between the money notes and other objects with the same shape. A number of IT-based solutions have been proposed to help and assist blind and/or visually impaired people. Generally speaking, these solutions, however, do not support Arabic languages nor protect blind users’ privacy. In this paper, Trusted Blind Society (TBS) mobile application is proposed. It is an android application which allows blind users to recognize their unknown surroundings by utilizing two concepts: social networks sites and friendsourcing. These two concepts were employed by allowing family members and the trusted friends, who are registered on Twitter, to answer blind users’ questions on a real time. The solution is also bilingual, supports (Arabic/English) and allows screen reader using Android talk-back service. The performance of the TBS system was evaluated using loader.io to check its stability under the heavy load and it was tested by a number of blind volunteers and the results showed good performance comparing to most related work
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Rapid detection of Mycobacterium ulcerans with isothermal recombinase polymerase amplification assay.
Background
Access to an accurate diagnostic test for Buruli ulcer (BU) is a research priority according to the World Health Organization. Nucleic acid amplification of insertion sequence IS2404 by polymerase chain reaction (PCR) is the most sensitive and specific method to detect Mycobacterium ulcerans (M. ulcerans), the causative agent of BU. However, PCR is not always available in endemic communities in Africa due to its cost and technological sophistication. Isothermal DNA amplification systems such as the recombinase polymerase amplification (RPA) have emerged as a molecular diagnostic tool with similar accuracy to PCR but having the advantage of amplifying a template DNA at a constant lower temperature in a shorter time. The aim of this study was to develop RPA for the detection of M. ulcerans and evaluate its use in Buruli ulcer disease.
Methodology and principal findings
A specific fragment of IS2404 of M. ulcerans was amplified within 15 minutes at a constant 42°C using RPA method. The detection limit was 45 copies of IS2404 molecular DNA standard per reaction. The assay was highly specific as all 7 strains of M. ulcerans tested were detected, and no cross reactivity was observed to other mycobacteria or clinically relevant bacteria species. The clinical performance of the M. ulcerans (Mu-RPA) assay was evaluated using DNA extracted from fine needle aspirates or swabs taken from 67 patients in whom BU was suspected and 12 patients with clinically confirmed non-BU lesions. All results were compared to a highly sensitive real-time PCR. The clinical specificity of the Mu-RPA assay was 100% (95% CI, 84–100), whiles the sensitivity was 88% (95% CI, 77–95).
Conclusion
The Mu-RPA assay represents an alternative to PCR, especially in areas with limited infrastructure.
Author summary
Current diagnostic methods to detect M. ulcerans suffer from delayed time-to-results in most endemic countries by the prolonged period of time for the shipment and storage of samples to a distant, centralized laboratory. The M. ulcerans recombinase polymerase amplification assay (Mu-RPA) is a new, rapid diagnostic test developed for the detection of M. ulcerans infection, known commonly as Buruli ulcer, a chronic, debilitating, necrotizing disease of the skin and soft tissues. This assay is suitable for use on a portable detection device, with the potential to be used for quick diagnosis at the point of need, providing timely results to health workers at Buruli ulcer treatment clinics
Cone beam CT evaluation of the presence of anatomic accessory canals in the jaws
Objectives:
To assess the prevalence, location and anatomical course of accessory canals of the jaws using cone beam CT.
Methods:
A retrospective analysis of 4200 successive cone beam CT scans, for patients of both genders and ages ranging from 7 to 88 years, was performed. They were exposed at the School of Dentistry, University of Michigan, Ann Arbor, MI. After applying the exclusion criteria (the presence of severe ridge resorption, pre-existing implants, a previously reported history of craniofacial malformations or syndromes, a previous history of trauma or surgery, inadequate image quality and subsequent scans from the same individuals), 4051 scans were ultimately included in this study.
Results:
Of the 4051 scans (2306 females and 1745 males) that qualified for inclusion in this study, accessory canals were identified in 1737 cases (42.9%; 1004 females and 733 males). 532 scans were in the maxilla (13.1%; 296 females and 236 males) and 1205 in the mandible (29.8%; 708 females and 497 males).
Conclusions:
A network of accessory canals bringing into communication the inner and outer cortical plates of the jaws was identified. In light of these findings, clinicians should carefully assess for the presence of accessory canals prior to any surgical intervention to decrease the risk for complications
Inference for the median residual life function in sequential multiple assignment randomized trials
In survival analysis, median residual lifetime is often used as a summary measure to assess treatment effectiveness; it is not clear, however, how such a quantity could be estimated for a given dynamic treatment regimen using data from sequential randomized clinical trials. We propose a method to estimate a dynamic treatment regimen‐specific median residual life (MERL) function from sequential multiple assignment randomized trials. We present the MERL estimator, which is based on inverse probability weighting, as well as, two variance estimates for the MERL estimator. One variance estimate follows from Lunceford, Davidian and Tsiatis' 2002 survival function‐based variance estimate and the other uses the sandwich estimator. The MERL estimator is evaluated, and its two variance estimates are compared through simulation studies, showing that the estimator and both variance estimates produce approximately unbiased results in large samples. To demonstrate our methods, the estimator has been applied to data from a sequentially randomized leukemia clinical trial. Copyright © 2013 John Wiley & Sons, Ltd.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/106925/1/sim6042.pd
Single-Layer Raster CNN simulator using RK-Gill
An efficient numerical integration algorithm for single layer Raster Cellular Neural Networks (CNN) simulator is presented in this paper. The simulator is capable of performing CNN simulations for any size of input image, thus a powerful tool for researchers investigating potential applications of CNN. This paper reports an efficient algorithm exploiting the latency properties of Cellular Neural Networks along with numerical integration techniques; simulation results and comparisons are also presented
Preliminary soil survey report for the Beni Magdoul and El Hammami areas
March 1979.CER78-79 EVR72.Includes bibliographical references.Prepared under support of United States Agency for International Development, Contract AID/NE-C-1351
Sensitivity Analysis of Inverse Probability Weighting Estimators of Causal Effects in Observational Studies with Multivalued Treatments
One of the fundamental challenges in drawing causal inferences from
observational studies is that the assumption of no unmeasured confounding is
not testable from observed data. Therefore, assessing sensitivity to this
assumption's violation is important to obtain valid causal conclusions in
observational studies. Although several sensitivity analysis frameworks are
available in the casual inference literature, very few of them are applicable
to observational studies with multivalued treatments. To address this issue, we
propose a sensitivity analysis framework for performing sensitivity analysis in
multivalued treatment settings. Within this framework, a general class of
additive causal estimands has been proposed. We demonstrate that the estimation
of the causal estimands under the proposed sensitivity model can be performed
very efficiently. Simulation results show that the proposed framework performs
well in terms of bias of the point estimates and coverage of the confidence
intervals when there is sufficient overlap in the covariate distributions. We
illustrate the application of our proposed method by conducting an
observational study that estimates the causal effect of fish consumption on
blood mercury levels
Geochemistry and water quality of Lake Qarun, Egypt
Water geochemistry is a very important tool for studying the water quality in a given area.
Geology and climate are the major natural factors controlling the chemistry of most natural
waters. Anthropogenic impacts are the secondary sources of contamination in natural waters.
This study presents the first integrative approach to the geochemistry and water quality of
surface waters and Lake Qarun in the Fayoum catchment, Egypt. Moreover, geochemical
modeling of Lake Qarun was firstly presented. The Nile River is the main source of water to the
Fayoum watershed. To investigate the quality and geochemistry of this water, water samples
from irrigation canals, drains and Lake Qarun were collected during the period 2010‒2013 from
the whole Fayoum drainage basin to address the major processes and factors governing the
evolution of water chemistry in the investigation area. About 34 physicochemical quality
parameters, including major ions, oxygen isotopes, trace elements, nutrients and microbiological
parameters were investigated in the water samples. Multivariable statistical analysis was used to
interpret the interrelationship between the different studied parameters. Geochemical modeling
of Lake Qarun was carried out using Hardie and Eugster’s evolutionary model and a model
simulated by PHREEQC software. The crystallization sequence during evaporation of Lake
Qarun brine was also studied using a Jänecke phase diagram involving the system Na‒K‒Mg‒
Cl‒SO4‒H2O.
The results show that the chemistry of surface water in the Fayoum catchment evolves from Ca-
Mg-HCO3 at the head waters to Ca‒Mg‒Cl‒SO4 and eventually to Na‒Cl downstream and at
Lake Qarun. The main processes behind the high levels of Na, SO4 and Cl in downstream waters
and in Lake Qarun are dissolution of evaporites from Fayoum soils followed by
evapoconcentration. This was confirmed by binary plots between the different ions, Piper plot,
Gibb’s plot and δ18O results. The modeled data proved that Lake Qarun brine evolves from
drainage waters via an evaporation‒crystallization process. Through the precipitation of calcite
and gypsum, the solution should reach the final composition "Na–Mg–SO4–Cl". As simulated by
PHREEQC, further evaporation of lake brine can drive halite to precipitate in the final stages of
evaporation. Significantly, the crystallization sequence during evaporation of the lake brine at the
concentration ponds of the Egyptian Salts and Minerals Company (EMISAL) reflected the
findings from both Hardie and Eugster’s evolutionary model and the PHREEQC simulated
model. After crystallization of halite at the EMISAL ponds, the crystallization sequence during
evaporation of the residual brine (bittern) was investigated using a Jänecke phase diagram at 35
°C. This diagram was more useful than PHREEQC for predicting the evaporation path especially
in the case of this highly concentrated brine (bittern). The predicted crystallization path using a
Jänecke phase diagram at 35 °C showed that halite, hexahydrite, kainite and kieserite should appear during bittern evaporation. Yet the actual crystallized mineral salts were only halite and
hexahydrite. The absence of kainite was due to its metastability while the absence of kieserite
was due to opposed relative humidity. The presence of a specific MgSO4.nH2O phase in ancient
evaporite deposits can be used as a paleoclimatic indicator.
Evaluation of surface water quality for agricultural purposes shows that some irrigation waters
and all drainage waters have high salinities and therefore cannot be used for irrigation. Waters
from irrigation canals used as a drinking water supply show higher concentrations of Al and
suffer from high levels of total coliform (TC), fecal coliform (FC) and fecal streptococcus (FS).
These waters cannot be used for drinking or agricultural purposes without treatment, because of
their high health risk. Therefore it is crucial that environmental protection agencies and the
media increase public awareness of this issue, especially in rural areas
Reprogramming of hepatic fat accumulation and 'browning' of adipose tissue by the short-chain fatty acid acetate
Background/Objectives:
Short-chain fatty acids, produced by microbiome fermentation of carbohydrates, have been linked to a reduction in appetite, body weight and adiposity. However, determining the contribution of central and peripheral mechanisms to these effects has not been possible.
Subjects/Methods:C57BL/6 mice fed with either normal or high-fat diet were treated with nanoparticle-delivered acetate, and the effects on metabolism were investigated.
Results:In the liver, acetate decreased lipid accumulation and improved hepatic function, as well as increasing mitochondrial efficiency. In white adipose tissue, it inhibited lipolysis and induced 'browning', increasing thermogenic capacity that led to a reduction in body adiposity.
Conclusions:This study provides novel insights into the peripheral mechanism of action of acetate, independent of central action, including ‘browning’ and enhancement of hepatic mitochondrial function
Pattern of sinonasal tumours presented in Shaheed Ziaur Rahman Medical College Hospital, Bogura, Bangladesh
Introduction: Sinonasal tumors most commonly arise from the nasal cavity, followed by the maxillary and ethmoid sinus; sphenoid and frontal sinus tumors are both extremely rare entities. In the sinonasal complex, squamous cell carcinoma (SCC) is the most common histology, constituting 40 to 50% of all sinonasal malignancies. Objective: To assess the pattern of sinonasal tumors presented in Shaheed Ziaur Rahman Medical College Hospital, Bogura, Bangladesh. Methods: This is a retrospective study carried out in the Department of ENT & Head-Neck Surgery, Shaheed Ziaur Rahman Medical College Hospital, Bogura, Bangladesh from January to June 2022. It includes 52 cases of neoplastic sinonasal growths. All cases were thoroughly evaluated including history, head and neck examination including endoscopy, imaging and histopathological examinations. All the non-neoplastic cases were excluded from the study. Details of clinical presentation, examination, radiological and histopathological findings were recorded. Results: A total of 52 sinonasal tumors presented during the period. Out of which, 41 were benign and 12 were malignant tumors. Out of 41 benign tumors, inverted papilloma was the most common comprising 12 cases (22.6%) followed by squamous (epithelial) papilloma 11 cases (20.8%), hemangioma 10 cases (18.9%), osteoma and fibrous dysplasia each 2 cases (3.8%) and ossifying fibroma, pleomorphic adenoma and angiomyoma one case each (2%). Out of 12 malignant tumors, squamous cell carcinoma was the commonest malignancy observed in the study. They were four in number (7.5%), followed by basal cell carcinoma in three cases (5.7%) and malignant melanoma in two (3.8%). Adenocarcinoma, osteosarcoma and Rhabdomyosarcoma were each one in number (5.37%) (Table-1). Nasal blockage (94.3%), nasal discharge (66.04%), epistaxis (39.6%), hemifacial pain/pressure (34%) and facial fullness/external deformities, each (18.9%) were among the commonest presentation. Conclusion: The similarities of benign and malignant disorders at initial presentation may lead to a significant delay in the diagnosis of malignancy. Key indicators of malignancy such as cranial neuropathies and proptosis are uncommon at initial presentation and signify advanced disease. Neoplasms of the nasal cavity and paranasal sinuses are rare but require a high index of suspicion for diagnosis due to the overlapping presentation between benign and malignant ones
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