Trypanocidal efficacy of two indigeneous ethanolic plant extracts (Mimosa pigra and Ipomoea asarifolia) against Trypanosoma evansi phospholipase A2 activity

AbstractObjectiveTo study the inhibitory activity of ethanolic extract from Mimosa pigra and Ipomoea asarifolia against Trypanosoma evansi (T. evansi) calcium dependent phospholipase A2.MethodsThe calcium dependent phospholipase A2 (E C 3.1.1.4) enzyme was isolated from T. evansi and purified to electrophoretic homogeneity under non denaturing conditions. It was solubilized from T. evansi cells recovered from white albino rats which were previously inoculated by intraperitoneal injection of infected camel blood. Two indigeneous ethanolic plant extracts used locally for treatment of trypanosomiasis were tested for the inhibition of phospholipases A2.ResultsDouble reciprocal plots of the initial velocity data of the inhibition by the indigenous plant extracts revealed a noncompetitive pattern of inhibition for the Ipomoea asarifolia and a competitive inhibition for Mimosa pigra in a dose dependent fashion. The extrapolated inhibition binding constant (Ki) of these extracts were found to be 2.0×102 μg/mL and 1.12×102 μg/mL respectively.ConclusionsThe low Ki values obtained for these extracts towards this enzyme are an indication of high affinity of the extract or the active components (present in the plants) are for these enzyme and therefore, could be explored to serve as a cheap source of T. evansi PLA2 antidote and as well help in designing a novel drug with high efficiency

Exploratory study to evaluate respiratory rate using a thermal imaging camera

Background: Respiratory rate is a vital physiological measurement used in the immediate assessment of unwell children and adults. Convenient electronic devices exist for measurement of pulse, blood pressure, oxygen saturation and temperature. Although devices which measure respiratory rate exist, none has entered everyday clinical practice for acute assessment of children and adults. An accurate and practical device which has no physical contact with the patient is important to ensure readings are not affected by distress caused by the assessment method. Objective: To evaluate the use of a thermal imaging method to monitor respiratory rate in children and adults. Methods: Facial thermal images of adult volunteers and children undergoing elective polysomnography were included. Respiration was recorded for at least two minutes with the camera positioned one metre from the subject's face. Values obtained using the thermal imaging camera were compared with those obtained from contact methods such as nasal thermistor, respiratory inductance plethysmography, nasal airflow and End Tidal Carbon Dioxide (CO2). Results: A total of 61 subjects, including 41 adults (age range 27 to 46 years) and 20 children (age range 0.5 to 18 years) were enrolled. The correlation between respiratory rate measured using thermal imaging and the contact method was r=0.94. Sequential refinements to the thermal imaging algorithms resulted in the ability to perform real-time measurements and an improvement of the correlation to r=0.995. Conclusion: This exploratory study shows that thermal imaging derived respiratory rates in children and adults correlate closely with the best performing standard method. With further refinements, this method could be implemented in both acute and chronic care in children and adults

Thermal image processing for real-time noncontact respiration rate monitoring

A real-time thermal imaging based, non-contact respiration rate monitoring method was developed. It measured the respiration related skin surface temperature changes under the tip of the nose. Facial tracking was required as head movements caused the face to appear in different locations in the recorded images over time. The algorithm detected the tip of the nose and then, a region just under it was selected. The pixel values in this region in successive images were processed to determine respiration rate. The segmentation method, used as part of the facial tracking, was evaluated on 55,000 thermal images recorded from 14 subjects with different extent of head movements. It separated the face from image background in all images. However, in 11.7% of the images, a section of the neck was also included, but this did not cause an error in determining respiration rate. The method was further evaluated on 15 adults, against two contact respiration rate monitoring methods that tracked thoracic and abdominal movements. The three methods gave close respiration rates in 12 subjects but in 3 subjects, where there were very large head movements, the respiration rates did not match

Throughput analysis of TCP congestion control algorithms in a cloud based collaborative virtual environment

Collaborative Virtual Environment (CVE) has become popular in the last few years, this is because CVE is designed to allow geographically distributed users to work together over the network. In CVE the state of the virtual objects is witnessing unprecedentant change. When a user performs an action in CVE, the information of the action needs to be transmitted to other users to maintain consistency in the cooperative work. TCP is the most widely used protocol in the design of CVE, and its throughput deteriorates in the network with large delay. Gital et al, 2014 proposes a cloud based architectural model for improving scalability and consistency in CVE. Therefore, this paper aim at evaluating and comparing the performance of different TCP variant (Tahoe, Reno, New Reno, Vegas, SACK, Fack and Linux) with the cloud based CVE architecture to determine the suitability of each TCP variant for CVE. A comparative analysis between the different TCP variants is presented in terms of throughput verses elapse time, with increasing number of users in the system. TCP with the cloud based model was found to be effective, promising and robust for achieving consistency requirement in CVE system

Thermal imaging method for measurement of respiratory rate

Background: Monitoring respiratory rate (RR) is an important task for medical diagnosis that is neglected due to complexities in performing it. Current methods require the sensing device to be attached to the subjects' body thereby constraining or causing them discomfort and thus potentially affecting the breathing rate. We have developed a noncontact method for RR monitoring using a thermal camera.Method: Algorithms to capture images and detect the location of the face in each image were developed. The amount of emitted infrared radiation was then determined and signal processing techniques were then utilised to obtain the respiration rate in real time. A FLIR A40 thermal camera was used in this study. The evaluations were conducted against five existing contact based methods. Results: Tests were conducted on 51 adults (mean age 35.7) and 20 children (mean age 6.4 years). Mean RR (thermal imaging) 14.8 per minute; (chest and abdominal band) 14.8 per minute in adults. The correlation coefficient was 0.88 - 0.998 in adults and 0.578 – 0.999 in children depending on the method used. Figure 1 shows a respiration signal for a child obtained during the evaluation

Detecting mobile producer’s position in a wireless named data network environment using signal strength

Named Data Networking (NDN) is a new Content Centric Network architecture that can possibly overwhelm most issues of IP mobility and security. The NDN is centered on addressing contents by themselves using names, rather than assigning IP addresses to packets on hosts where information is located on the global Internet. Due to the developing scope of remote access around the world and Wi-Fi accessibility, scenarios change because of additional networking devices. This paper analyses existing methodologies of mobile device communication using Wi-Fi in NDN. This involves using a mobile producer and a rendezvous node connected via content routers in an NDN scenario. Their location is detected and predicted immediately handoff occur and it send content transmission as a consumer. The approach of transmitting content signals uses sign power pointer (RSSI), TOA, and TSE in the network. Several challenges were noted and pointed out enhance future work

Evaluating mobility management models for content forwarding in named data networking environments

Named Data Networking (NDN) performs its routing and forwarding decisions using name prefixes. This removes some of the issues affecting addresses in our traditional IP architecture such as limitation in address allocation and management, and even NAT translations etcetera. Another positivity of NDN is its ability to use the conventional routing like the link state and distance vector algorithm. In route announcement, NDN node broadcasts its name prefix which consists of the knowledge of the next communicating node. In this paper, we evaluate the performance of mobility management models used in forwarding NDN contents to a next hop. This makes it crucial to select an approach of mobility model that translates the nature of movement of the NDN mobile routers. A detailed analysis of the famous mobility model such as the Random Waypoint mobility and Constant Velocity were computed to determine the mobility rate of the NDN mobile router. Simulation analysis was carried out using ndnSIM 2.1 on Linux Version 16.1. we build and compile with modules and libraries in NS-3.29. The sample of movement of the mobile router is illustrated and our result present the viability of the Constant Velocity model as compared with the Random Way point. Keywords—Named Data Networking, Prefix, Broadcast, ndnSIM, NS-3.2

Performance evaluation of best route and broadcast strategy for NDN producer’s mobility

Named Data Networking is a novel concept mainly for the future Internet infrastructure that is centered on routable named data. The NDN infrastructure comprises of a new constituent known as the strategy layer. The layer give access for automatic selection of network routes by considering network pre-conditions such as delay in Interest messages forwarding via a producer. However, expressing appropriate pre-condition in selecting the best possible routes to forward Interest messages remains a challenging factor in NDN, because various parameters and conditions opposes one another when selecting best routes. Besides, it is possible for data in NDN to be retrieved from several sources. Yet, so far preceding research on forwarding strategy techniques that can calculate, from which route accurate NDN data contents content are realized does not regard a network attacker trying to transmit invalid data contents containing same name as accurate data. Therefore, this paper evaluate performance of forwarding strategy using analytical and simulation, and that can be compatible to related network applications such as voice. In analytical, we exploit the use of distribution function for consistency. These are the Probability Density Function (PDF) and Cumulative Distribution Function (CDF). In simulation, each application require its own form of forwarding policy using best route and broadcast. These were exploited to evaluate the total delay in a given interval from 10 through 50 seconds for five times. Similarly in our evaluation, a largescale ring topology was use in the simulation consisting of 30 nodes and 48 links. Link bandwidth is configured as 1Mbps. Numbers of content consumer/producer starts from 1 to 18 so as to achieve our simulations. Both consumers and producers were randomly selected in term of unique content request on the access network. ndnSIM 2.1 is used in simulating the scenarios for several time intervals. Performance results presents best route policy carries significant delay when compared with broadcast policy. Also, in our result, Delay metric is half the value obtained during analytical and simulation processes for NDN producer’s best route and broadcast using CDF, as compared to the value realized in our benchmark paper for NDN consumer

Simulation of handoff algorithm for NDN producer’s mobility

Named Data networking is a novel communication scheme designed for efficient data dissemination. NDN is cantered on content management to improve on IP challenges such mobility, scalability, security and better quality of service. In this paper, producer’s mobility between two points is set-up for simulation using hard handoff technique. In this form of handoff, the carrier frequency of a connecting access gateway remains the same with the newly visited gateway of the producer (i.e intra-frequency). The mobile producer in node 3 is requesting a video content to another producer in node 4 while in a state of mobility. We considered anchorless technique of managing mobility of the nodes and simulation ensures that contents still receive routing update as they achieve handoff. These set-ups of simulation were conducted using NetSim version 12.10 software. In the results, we present video application throughput and the link throughput of link 1, link 2 and link 7 and comprehend that, efficiency and seamless mobility is realized using video application as compared to link throughout. Network and queued metrics also present more results being generated after the simulation processes. The algorithm of our inputs is tested in MATLAB and part of the coding system is build using visual studio 2015 which by default, is compatible with NetSim “binary” and “dll” folders

Short-time Fourier and wavelet transform analysis of respiration signal obtained by thermal imaging

Respiration rate is a critical sign of a person's wellbeing. The respiration rate of an adult subject was measured for eight minutes using a thermal imaging technique. A suitable algorithm was used to locate and track the respiration region of interest centred on the tip of the nose. The effectiveness of short time Fourier transform (STFT) and continuous wavelet transform (CWT) to determine respiration rate variations over time was investigated. The study indicated that both STFT and CWT can indicate respiration rate time variations, but CWT was more sensitive in detecting the transient changes in respiration signal