58 research outputs found
Chain-Based Anonymous Routing for Wireless Ad Hoc Networks
Wireless ad hoc networks are so vulnerable to passive attacks and eavesdropping adversaries due to their shared medium which makes network traffic easy to capture and analyze. Therefore, security and privacy protections are of extreme importance for protocols and applications in such networks. In this paper, we introduce a new framework for anonymous routing, named chain-based routing, to improve the privacy. In our framework, nodes on a path are virtually bound to each other like a chain. Each node is only aware of its associated links in a flow and does not require any other information about source, destination, or other parts of the chain. Based on this framework, we propose an on-demand routing protocol, called Chain-based Anonymous Routing (CAR), which uses unicast-based broadcast data transfer to fulfill anonymous communication in wireless ad hoc networks. Through hiding identifiers of nodes inside the chain, CAR realizes sender, receiver, and relationship anonymity in addition to untraceability in the network. Moreover, it is resistant to a wide range of passive attacks while adapting to implement other security mechanisms in the presence of active attacks
Reducing Buffer Space in Multipath Schemes
One major drawback of multipath transferring schemes, which is inspired by the usage of different paths with diverse delays, is the emergence of reordering among packets of a flow. This reordering brings some substantial problems (like larger delay and buffer space) to the transport applications. In this paper, we present a novel UDP-based multipath scheme for in-order delivery to the receiver by scheduling of packets among multiple paths. This method imposes the minimum possible delay and a small buffer space on the receiver’s application. We theoretically prove the optimality of the proposed method. Finally, through simulation experiments, we show that the performance of our multipath method is comparable with the best-case one-path transmission with aggregated bandwidth
Can the kidney volume help to differentiate the types of rejection before biopsy?
Background: The aim of this study was to use the volume of the graft as an adjunct tool for better decision making. Methods: Kidney transplanted patients with acute azotemia and documented volume and finally a biopsy were enrolled in this study‌. Graft volumes between rejected patients (antibody-mediated rejection AMR and cell - mediated rejection CMR) and ‌non rejected but azotemic patients were compared. Results: A total of 76 patients were enrolled in this study ‌(45 case and 31 control‌). 53.3 of the case group were‌ (AMR)‌ and 46.7 belonged to ‌(CMR). There was no difference between kidney volume according to age or sex. But the case group had a significantly bigger volume than controls (253.09 cm3 and 186.45 cm3; p< 0.001). In addition, there was a significant difference between the volumes of AMR kidneys with CMR and controls ‌(286.24+66.70‌, 224.08+76.79 and 186.95+39.92; P=0.003 and p<0.001, respectively), but not between CMR and controls ‌(P=0.067). A cutoff point of 200 cm3 was determined as rejection with sensitivity and specificity of 70 and a cutoff point of 250 cm3 could be used as AMR cut off with sensitivity of 76 and specificity of 70. Conclusion: There was a significant difference in volume between rejection and control group and between AMR and CMR. So, kidney volume determination is an easy and valuable tool to help the clinician to have a more rapid and better decision making
Comparative histological and histochemical inter-species investigation of mammalian sub mandibular salivary glands
The major and accessory sub mandibular glands were obtained from different species of rodents belong to families Muridae (Meriones lybicus, Mus musculs, Cricetulus migraturus, Nesokia indica, Laboratory hamster and Apodemus sp.)? Dipodidae (Alactage elater and Jucullus blanfordi) and Sciuridae (Funambulus pennanti). The skulls of these species were separated immediately after death and fixed in buin with decalcification. Five um sections were stained with hematoxilen-eosin and tetrachrom. Periodic acid shiff and alcian blue (pH 1) were performed for sulfated natural mucins. Microscopic histological features, including existence of mucus and serous acini, presence of different kinds of tubules and different types of ducts as well as the histochemical characteristic features including histochemistry of different tubules and ducts in 2 different pH levels in the major and accessory sub mandibular glands in different rodents showed that the studied species proved to be different and the histological and histochemical study of sub mandibular salivary glands proved practicable with good discriminatory potential in evaluating the inter-species differences
The Antidepressant Activity of Matricaria chamomilla and Melissa officinalis Ethanolic Extracts in Non-Reserpinized and Reserpinized Balb/C Mice
Background: Matricaria chamomilla and Melissa officinalis have been used as antidepressants in traditional Iranian medicine.
Objectives: The aim of this study was to determine the effectiveness of Matricaria chamomilla and Melissa officinalis extracts compared to the classic antidepressant drug, imipramine, in adult non-reserpinized and reserpinized mice through the forced swim test.
Methods: In the current experimental study, 80 mice were divided into 10 groups. The first group received normal saline and the second and third groups received 25 and 50 mg/kg of Matricaria chamomilla extract, respectively. The fourth and the fifth groups received 25 and 50 mg/kg of Melissa officinalis extract. The sixth group received imipramine at a dose of 15 mg/kg. The seventh group received 5 mg/kg of reserpine and normal saline. The eighth and ninth groups received 25 and 50 mg/kg of Melissa officinalis and Matricaria chamomilla extracts, respectively. The tenth group was given imipramine through intraperitoneal (I.P) injection. Statistical analyses were performed using one-way analysis of variance (ANOVA) followed by Tukey's post hoc test in SPSS.
Results: Matricaria chamomilla (50 mg/kg), Melissa officinalis (25 mg/kg), and imipramine (15 mg/kg) in non-reserpinized mice significantly decreased the duration of immobility in the forced swim test compared to the control group (P < 0.01). There was a reduction in the duration of immobility in the reserpinized mice administered Matricaria chamomilla at a dose of 50 mg/kg compared to the positive control group (P < 0.01).
Conclusions: Matricaria chamomilla and Melissa officinalis have antidepressant effects and maybe taken into consideration in treating patients suffering from depressio
Bulk crystal growth and electronic characterization of the 3D Dirac Semimetal Na3Bi
High quality hexagon plate-like Na3Bi crystals with large (001) plane
surfaces were grown from a molten Na flux. The freshly cleaved crystals were
analyzed by low temperature scanning tunneling microscopy (STM) and
angle-resolved photoemission spectroscopy (ARPES), allowing for the
characterization of the three-dimensional (3D) Dirac semimetal (TDS) behavior
and the observation of the topological surface states. Landau levels (LL) were
observed, and the energy-momentum relations exhibited a linear dispersion
relationship, characteristic of the 3D TDS nature of Na3Bi. In transport
measurements on Na3Bi crystals the linear magnetoresistance and Shubnikov-de
Haas (SdH) quantum oscillations are observed for the first time.Comment: To be published in a special issue of APL Material
Indoor environment assessment of special wards of educational hospitals for the detection of fungal contamination sources: A multi-center study (2019-2021)
Background and Purpose: The hospital environment was reported as a real habitat for different microorganisms, especially mold fungi. On the other hand, these opportunistic fungi were considered hospital-acquired mold infections in patients with weak immune status. Therefore, this multi-center study aimed to evaluate 23 hospitals in 18 provinces of Iran for fungal contamination sources.Materials and Methods: In total, 43 opened Petri plates and 213 surface samples were collected throughout different wards of 23 hospitals. All collected samples were inoculated into Sabouraud Dextrose Agar containing Chloramphenicol (SC), and the plates were then incubated at 27-30ºC for 7-14 days.Results: A total of 210 fungal colonies from equipment (162, 77.1%) and air (48,22.9%) were identified. The most predominant isolated genus was Aspergillus (47.5%),followed by Rhizopus (14.2%), Mucor (11.7%), and Cladosporium (9.2%). Aspergillus(39.5%), Cladosporium (16.6%), as well as Penicillium and Sterile hyphae (10.4% each), were the most isolates from the air samples. Moreover, intensive care units (38.5%) and operating rooms (21.9%) had the highest number of isolated fungal colonies. Out of 256 collected samples from equipment and air, 163 (63.7%) were positive for fungal growth.The rate of fungal contamination in instrument and air samples was 128/213 (60.1%) and 35/43 (81.2%), respectively. Among the isolated species of Aspergillus, A. flavus complex (38/96, 39.6%), A. niger complex (31/96, 32.3%), and A. fumigatus complex (15/96, 15.6%) were the commonest species.Conclusion: According to our findings, in addition to air, equipment and instrument should be considered among the significant sources of fungal contamination in the indoor environment of hospitals. Airborne fungi, Hospital, Indoor air, Equipment, Sources of fungal contamination in the indoor environment of hospitals
Burden of disease scenarios for 204 countries and territories, 2022–2050: a forecasting analysis for the Global Burden of Disease Study 2021
Background: Future trends in disease burden and drivers of health are of great interest to policy makers and the public at large. This information can be used for policy and long-term health investment, planning, and prioritisation. We have expanded and improved upon previous forecasts produced as part of the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) and provide a reference forecast (the most likely future), and alternative scenarios assessing disease burden trajectories if selected sets of risk factors were eliminated from current levels by 2050. Methods: Using forecasts of major drivers of health such as the Socio-demographic Index (SDI; a composite measure of lag-distributed income per capita, mean years of education, and total fertility under 25 years of age) and the full set of risk factor exposures captured by GBD, we provide cause-specific forecasts of mortality, years of life lost (YLLs), years lived with disability (YLDs), and disability-adjusted life-years (DALYs) by age and sex from 2022 to 2050 for 204 countries and territories, 21 GBD regions, seven super-regions, and the world. All analyses were done at the cause-specific level so that only risk factors deemed causal by the GBD comparative risk assessment influenced future trajectories of mortality for each disease. Cause-specific mortality was modelled using mixed-effects models with SDI and time as the main covariates, and the combined impact of causal risk factors as an offset in the model. At the all-cause mortality level, we captured unexplained variation by modelling residuals with an autoregressive integrated moving average model with drift attenuation. These all-cause forecasts constrained the cause-specific forecasts at successively deeper levels of the GBD cause hierarchy using cascading mortality models, thus ensuring a robust estimate of cause-specific mortality. For non-fatal measures (eg, low back pain), incidence and prevalence were forecasted from mixed-effects models with SDI as the main covariate, and YLDs were computed from the resulting prevalence forecasts and average disability weights from GBD. Alternative future scenarios were constructed by replacing appropriate reference trajectories for risk factors with hypothetical trajectories of gradual elimination of risk factor exposure from current levels to 2050. The scenarios were constructed from various sets of risk factors: environmental risks (Safer Environment scenario), risks associated with communicable, maternal, neonatal, and nutritional diseases (CMNNs; Improved Childhood Nutrition and Vaccination scenario), risks associated with major non-communicable diseases (NCDs; Improved Behavioural and Metabolic Risks scenario), and the combined effects of these three scenarios. Using the Shared Socioeconomic Pathways climate scenarios SSP2-4.5 as reference and SSP1-1.9 as an optimistic alternative in the Safer Environment scenario, we accounted for climate change impact on health by using the most recent Intergovernmental Panel on Climate Change temperature forecasts and published trajectories of ambient air pollution for the same two scenarios. Life expectancy and healthy life expectancy were computed using standard methods. The forecasting framework includes computing the age-sex-specific future population for each location and separately for each scenario. 95% uncertainty intervals (UIs) for each individual future estimate were derived from the 2·5th and 97·5th percentiles of distributions generated from propagating 500 draws through the multistage computational pipeline. Findings: In the reference scenario forecast, global and super-regional life expectancy increased from 2022 to 2050, but improvement was at a slower pace than in the three decades preceding the COVID-19 pandemic (beginning in 2020). Gains in future life expectancy were forecasted to be greatest in super-regions with comparatively low life expectancies (such as sub-Saharan Africa) compared with super-regions with higher life expectancies (such as the high-income super-region), leading to a trend towards convergence in life expectancy across locations between now and 2050. At the super-region level, forecasted healthy life expectancy patterns were similar to those of life expectancies. Forecasts for the reference scenario found that health will improve in the coming decades, with all-cause age-standardised DALY rates decreasing in every GBD super-region. The total DALY burden measured in counts, however, will increase in every super-region, largely a function of population ageing and growth. We also forecasted that both DALY counts and age-standardised DALY rates will continue to shift from CMNNs to NCDs, with the most pronounced shifts occurring in sub-Saharan Africa (60·1% [95% UI 56·8–63·1] of DALYs were from CMNNs in 2022 compared with 35·8% [31·0–45·0] in 2050) and south Asia (31·7% [29·2–34·1] to 15·5% [13·7–17·5]). This shift is reflected in the leading global causes of DALYs, with the top four causes in 2050 being ischaemic heart disease, stroke, diabetes, and chronic obstructive pulmonary disease, compared with 2022, with ischaemic heart disease, neonatal disorders, stroke, and lower respiratory infections at the top. The global proportion of DALYs due to YLDs likewise increased from 33·8% (27·4–40·3) to 41·1% (33·9–48·1) from 2022 to 2050, demonstrating an important shift in overall disease burden towards morbidity and away from premature death. The largest shift of this kind was forecasted for sub-Saharan Africa, from 20·1% (15·6–25·3) of DALYs due to YLDs in 2022 to 35·6% (26·5–43·0) in 2050. In the assessment of alternative future scenarios, the combined effects of the scenarios (Safer Environment, Improved Childhood Nutrition and Vaccination, and Improved Behavioural and Metabolic Risks scenarios) demonstrated an important decrease in the global burden of DALYs in 2050 of 15·4% (13·5–17·5) compared with the reference scenario, with decreases across super-regions ranging from 10·4% (9·7–11·3) in the high-income super-region to 23·9% (20·7–27·3) in north Africa and the Middle East. The Safer Environment scenario had its largest decrease in sub-Saharan Africa (5·2% [3·5–6·8]), the Improved Behavioural and Metabolic Risks scenario in north Africa and the Middle East (23·2% [20·2–26·5]), and the Improved Nutrition and Vaccination scenario in sub-Saharan Africa (2·0% [–0·6 to 3·6]). Interpretation: Globally, life expectancy and age-standardised disease burden were forecasted to improve between 2022 and 2050, with the majority of the burden continuing to shift from CMNNs to NCDs. That said, continued progress on reducing the CMNN disease burden will be dependent on maintaining investment in and policy emphasis on CMNN disease prevention and treatment. Mostly due to growth and ageing of populations, the number of deaths and DALYs due to all causes combined will generally increase. By constructing alternative future scenarios wherein certain risk exposures are eliminated by 2050, we have shown that opportunities exist to substantially improve health outcomes in the future through concerted efforts to prevent exposure to well established risk factors and to expand access to key health interventions
Ontology matching using vector space
Interoperability of heterogeneous systems on the Web will be achieved through an agreement between the underlying ontologies. Ontology matching is an operation that takes two ontologies and determines their semantic mapping. This paper presents a method of ontology matching which is based on modeling ontologies in a vector space and estimating their similarity degree by matching their concept vectors. The proposed method is successfully applied to the test suit of Ontology Alignment Evaluation Initiative 2005 [10] and compared to the results reported by other methods. In terms of precision and recall, the results look promising
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