AIM:To identify optimum timing to maximize diagnostic yield by capsule endoscopy (CE) in patients with obscure gastrointestinal bleeding (OGIB).METHODS:We identified patients who underwent CE at our institution from A...AIM:To identify optimum timing to maximize diagnostic yield by capsule endoscopy (CE) in patients with obscure gastrointestinal bleeding (OGIB).METHODS:We identified patients who underwent CE at our institution from August 2003 to December 2009.Patient medical records were reviewed to determine type of OGIB (occult,overt),CE results and complications,and timing of CE with respect to onset of bleeding.RESULTS:Out of 385 patients investigated for OGIB,284 (74%) had some lesion detected by CE.In 222 patients (58%),definite lesions were detected that could unequivocally explain OGIB.Small bowel ulcer/erosions secondary to Crohn's disease,tuberculosis or non-steroidal anti-inflammatory agent use were the commonest lesions detected.Patients with overt GI bleeding for < 48 h before CE had the highest diagnostic yield (87%).This was significantly greater (P < 0.05) compared to that in patients with overt bleeding prior to 48 h (68%),as well as those with occult OGIB (59%).CONCLUSION:We established the importance of early CE in management of OGIB.CE within 48 h of overt bleeding has the greatest potential for lesion detection.展开更多
The evolution in communication techniques has created wide threats for crucial information transfer through a communication channel. Covert communication with steganography is a skill of concealing secret information ...The evolution in communication techniques has created wide threats for crucial information transfer through a communication channel. Covert communication with steganography is a skill of concealing secret information within cover object and hence shields the data theft over rapidly growing network.Recently, diverse steganography techniques using edge identification have been proposed in literature.Numerous methods however utilize certain pixels in the cover image for inserting edge information,resulting in significant deformation. The conventional edge detection method limits the deployment of edge detection in steganography as concealing the information would introduce some variations to the cover image. Hence inserting data in pixel areas recognized by existing conventional edge detection techniques like canny cannot ensure the recognition of the exact edge locations for the cover and stego images. In this paper, an Adaptive steganography method based on novel fuzzy edge identification is proposed. The method proposed is proficient of estimating the precise edge areas of a cover image and also ensures the exact edge location after embedding the secret message. Experimental results reveal that the technique has attained good imperceptibility compared to the Hayat AI-Dmour and Ahmed AIAni Edge XOR method in spatial domain.展开更多
Natural fibre-reinforced composites are now becoming incredibly common in various products because of their comparable qualities to conventional materials.Due to its availability,superior mechanical qualities,and low ...Natural fibre-reinforced composites are now becoming incredibly common in various products because of their comparable qualities to conventional materials.Due to its availability,superior mechanical qualities,and low cost,banana pseudostem is extensively used in various applications requiring natural fibres.This study investigates the physical and mechanical properties of epoxy composites reinforced with banana pseudostem fibres that contain Al_(2)O_(3) particulate.In order to produce composites with fibre and filler loadings,manual hand layup was used.Fibre and filler loading effects on composite properties were studied in experiments.The results of the investigations demonstrate that proportion of Al_(2)O_(3) in composites significantly influences their mechanical and physical properties.Additionally,the composite with a fibre content of 30%shows improved mechanical proportions and hardness.Thermogravimetric analysis was used to study the composite's thermal behaviour.Composites are more thermally stable than raw epoxy.Fourier Transform Infrared Spectroscopy and Scanning electron microscopy analyses were used to characterize the composites.展开更多
In cryptography, the Triple DES (3DES, TDES or officially TDEA) is a symmetric-key block cipher which applies the Data Encryption Standard (DES) cipher algorithm three times to each data block. Electronic payment syst...In cryptography, the Triple DES (3DES, TDES or officially TDEA) is a symmetric-key block cipher which applies the Data Encryption Standard (DES) cipher algorithm three times to each data block. Electronic payment systems are known to use the TDES scheme for the encryption/decryption of data, and hence faster implementations are of great significance. Field Programmable Gate Arrays (FPGAs) offer a new solution for optimizing the performance of applications meanwhile the Triple Data Encryption Standard (TDES) offers a mean to secure information. In this paper we present a pipelined implementation in VHDL, in Electronic Code Book (EBC) mode, of this commonly used cryptography scheme with aim to improve performance. We achieve a 48-stage pipeline depth by implementing a TDES key buffer and right rotations in the DES decryption key scheduler. Using the Altera Cyclone II FPGA as our platform, we design and verify the implementation with the EDA tools provided by Altera. We gather cost and throughput information from the synthesis and timing results and compare the performance of our design to common implementations presented in other literatures. Our design achieves a throughput of 3.2 Gbps with a 50 MHz clock;a performance increase of up to 16 times.展开更多
Background:The purpose of the study is to understand the role of cash flow sensitivity to investment as a measure of financial constraints among listed Indian manufacturing firms.It also analyses the role of tangibili...Background:The purpose of the study is to understand the role of cash flow sensitivity to investment as a measure of financial constraints among listed Indian manufacturing firms.It also analyses the role of tangibility in alleviating financial constraints.Further,the role of other financial factors in investment decisions is explored.Methods:The study is conducted using the generalized method of moments(GMM)estimator on dynamic panel data for the period of(2009–2015)on 768 listed manufacturing firms.Results:The analysis finds that cash flow sensitivity is a valid measure of financial constraints in the Indian manufacturing sector.Results according to splitting criteria found that investment decisions of standalone firms are more sensitive to cash flow than group affiliated firms.Further,splitting the firms according to market capitalization and tangible net worth reveals a higher degree of cash flow sensitivity by firms with lower market capitalization and asset tangibility.The results for the effects of tangibility of assets on easing financial constraint were found significant only in the case of firms with low tangible net worth and medium market capitalization.Conclusions:The study confirms cash flow sensitivity to investment as a valid measure of financial constraints.It will confirm pooling of internal funds by financially constrained firms to accept profitable investment opportunities in future.Further,it also reports that asset tangibility eases the financial constraints faced by firms.展开更多
With the increase in the number of computers connected to Internet, the number of Distributed Denial of Service (DDoS) attacks has also been increasing. A DDoS attack consumes the computing resources of a computer or ...With the increase in the number of computers connected to Internet, the number of Distributed Denial of Service (DDoS) attacks has also been increasing. A DDoS attack consumes the computing resources of a computer or a server, by degrading its computing performance or by preventing legitimate users from accessing its services. Recently, Operating Systems (OS) are increasingly deploying embedded DDoS prevention schemes to prevent computing exhaustion caused by such attacks. In this paper, we compare the effectiveness of two popular operating systems, namely the Apple’s Lion and Microsoft’s Windows 7, against DDoS attacks. We compare the computing performance of these operating systems under two ICMP based DDoS attacks. Since the role of the OS is to manage the computer or servers resources as efficiently as possible, in this paper we investigate which OS manages its computing resources more efficiently. In this paper, we evaluate and compare the built-in security of these two operating systems by using an iMac computer which is capable of running both Windows 7 and Lion. The DDoS attacks that are simulated for this paper are the ICMP Ping and Land Attack. For this experiment, we measure the exhaustion of the processors and the number of Echo Request and Echo Reply messages that were generated under varying attack loads for both the Ping and Land Attack. From our experiments, we found that both operating systems were able to survive the attacks however they reacted a bit differently under attack. The Operating System Lion was handling both the Ping and Land attack in the exactly the same way, whereas Windows 7 handled the two attacks a bit differently, resulting in different processor consumptions by two different operating systems.展开更多
ARP-based Distributed Denial of Service (DDoS) attacks due to ARP-storms can happen in local area networks where many computer systems are infected by worms such as Code Red or by DDoS agents. In ARP attack, the DDoS ...ARP-based Distributed Denial of Service (DDoS) attacks due to ARP-storms can happen in local area networks where many computer systems are infected by worms such as Code Red or by DDoS agents. In ARP attack, the DDoS agents constantly send a barrage of ARP requests to the gateway, or to a victim computer within the same sub-network, and tie up the resource of attacked gateway or host. In this paper, we set to measure the impact of ARP-attack on resource exhaustion of computers in a local area network. Based on attack experiments, we measure the exhaustion of processing and memory resources of a victim computer and also other computers, which are located on the same network as the victim computer. Interestingly enough, it is observed that an ARP-attack not only exhausts resource of the victim computer but also significantly exhausts processing resource of other non-victim computers, which happen to be located on the same local area network as the victim computer.展开更多
Cyber attacks are continuing to hamper working of Internet services despite increased use of network secu-rity systems such as firewalls and Intrusion protection systems (IPS). Recent Distributed Denial of Service (DD...Cyber attacks are continuing to hamper working of Internet services despite increased use of network secu-rity systems such as firewalls and Intrusion protection systems (IPS). Recent Distributed Denial of Service (DDoS) attacks on Dec 8th, 2010 by Wikileak supporters on Visa and Master Card websites made headlines on prime news channels all over the world. Another famous DDoS attacks on Independence Day weekend, on July 4th, 2009 were launched to debilitate the US and South Korean governments’ websites. These attacks raised questions about the capabilities of the security systems that were used in the network to counteract such attacks. Firewall and IPS security systems are commonly used today as a front line defense mechanism to defend against DDoS attacks. In many deployments, performances of these security devices are seldom evaluated for their effectiveness. Different security devices perform differently in stopping DDoS attacks. In this paper, we intend to drive the point that it is important to evaluate the capability of Firewall or IPS secu-rity devices before they are deployed to protect a network or a server against DDoS attacks. In this paper, we evaluate the effectiveness of a security device called Netscreen 5GT (or NS-5GT) from Juniper Networks under Layer-4 flood attacks at different attack loads. This security device NS-5GT comes with a feature called TCP-SYN proxy protection to protect against TCP-SYN based DDoS attacks, and UDP protection feature to protect against UDP flood attacks. By looking at these security features from the equipments data sheet, one might assume the device to protect the network against such DDoS attacks. In this paper, we con-ducted real experiments to measure the performance of this security device NS-5GT under the TCP SYN and UDP flood attacks and test the performance of these protection features. It was found that the Juniper’s NS-5GT mitigated the effect of DDoS traffic to some extent especially when the attack of lower intensity. However, the device was unable to provide any protection against Layer4 flood attacks when the load ex-ceeded 40Mbps. In order to guarantee a measured level of security, it is important for the network managers to measure the actual capabilities of a security device, using real attack traffic, before they are deployed to protect a critical information infrastructure.展开更多
Muscular dystrophies are myopathies and tend to progressive, with ongoing degeneration and regeneration of muscle fibers. Spinal muscular atrophy (SMA), amyotrophic lateral sclerosis (ALS) and polio myelitis are essen...Muscular dystrophies are myopathies and tend to progressive, with ongoing degeneration and regeneration of muscle fibers. Spinal muscular atrophy (SMA), amyotrophic lateral sclerosis (ALS) and polio myelitis are essentially diseases of the anterior horn cells of the spine. It has been reported in literature that humoral immunity is manifested by the antibodies production. These are special chemical substances that react against foreign body. Antibodies are serum proteins, which are immunoglobulins and possess antibody activity and are classified according to antigens and stimulate their production such as IgA, JgG, IgM, IgD and IgE. All the immunological parameters such as of C3, C4, IgG, IgM and IgA, which are measured in Duchenne muscular dystrophy go down in comparison to healthy subjects. Complement C3 and Complement C4 go down about 44.3% and 78.57% respectively from the normal values. The serum IgG, IgM and IgA levels were also go down about 65%, 84% and 99.56% respectively in comparison to healthy subjects. A trend between all the immunoglobulins has been set up and it is rAG.M > rMA.G. > rGM.A, while we have a trend in DMD cases is rMA.G. > rAG.M > rGM.A We are in a position to say that our data have a relevance of high authenticity and reliability to accept that there is a deficit in immunity in DMD cases. The deficit in immunity may be a cause to damage muscle for abnormal functioning.展开更多
Change in land-use practices can result in major shifts in the cycling of various elements,particularly nitrogen(N),which is prone to anthropogenic perturbations.For quantifying these shifts,accurate measurements of r...Change in land-use practices can result in major shifts in the cycling of various elements,particularly nitrogen(N),which is prone to anthropogenic perturbations.For quantifying these shifts,accurate measurements of rates of biogeochemical transformations of N are needed.We used the(^(15)N) isotope dilution technique to understand the effects of the types of forest alteration on(N) transformation rates by comparing gross N mineralization and ammonium(NH_(4)^(+)) consumption rates in soils of a managed forest,an unmanaged forest,and a rubber plantation in Kerala,India.Overall,nitrate(NO_3~-) dominated soils of the managed and unmanaged forests,whereas soils in the rubber plantation showed relatively higher NH_(4)^(+) concentration.Total N(TN) and total organic carbon(TOC) concentrations were the highest under the rubber canopy(TN:1.49±0.02 mg N g^(-1);TOC:7.96±0.86 mg C g^(-1)).In soils of all three forest types,gross N mineralization rates were higher compared to NH_(4)^(+) consumption rates.Despite high TN and TOC concentrations,the rates of gross N mineralization and NH_(4)^(+) consumption were considerably lower in the rubber plantation(mineralization:1.08±0.08 mg N kg^(-1)d^(-1);consumption:0.85±0.09 mg N kg^(-1) d^(-)) compared to the managed(mineralization:3.71±0.35 mg N kg^(-1) d^(-1);consumption:2.20±1.41 mg N kg^(-1) d^(-1)) and unmanaged(mineralization:2.20±1.07 mg N kg^(-1) d^(-1);consumption:1.39±0.27 mg N kg^(-1) d^(-1)) forests.The lower NH_(4)^(+) consumption rates in the rubber plantation led to significantly higher(p<0.05) residence time of NH_(4)^(+)(~4 days) compared to the managed and unmanaged forests(<2 days),possibly contributing to acidification of rubber soils(pH~4.8).These results together suggest that replacement of naturally grown forests with a mono-cropped plantation such as rubber negatively impact rates of N transformation processes in tropical soils and imply that change in tree species composition of naturally grown forests can adversely affect soil microbial activity.We recommend intercropping these plantations with commercial crops to maintain soil microbial diversity and biogeochemical cycling for sustainable forest management.展开更多
In this paper, we present and analyze modified families of predictor-corrector iterative methods for finding simple zeros of univariate nonlinear equations, permitting near the root. The main advantage of our methods ...In this paper, we present and analyze modified families of predictor-corrector iterative methods for finding simple zeros of univariate nonlinear equations, permitting near the root. The main advantage of our methods is that they perform better and moreover, have the same efficiency indices as that of existing multipoint iterative methods. Furthermore, the convergence analysis of the new methods is discussed and several examples are given to illustrate their efficiency.展开更多
A series of sulpha/substituted derivatives of phenyl azo-1,2-diazole have been synthesized and tested as an anti-inflammatory and anti-bacterial activity in mature albino rats hind paw by taking Diclofenac sodium as s...A series of sulpha/substituted derivatives of phenyl azo-1,2-diazole have been synthesized and tested as an anti-inflammatory and anti-bacterial activity in mature albino rats hind paw by taking Diclofenac sodium as standard. N1-(4-hydroxy benzoyl)-3-methyl-5-phenyl-4(N-4-chlorophenylazo)-1,2-diazole is synthesized by a two-step process. In the first step, synthesis of N1-4-chlorophenyl hydrazono-1-methyl-3-phenyl propane-1,3-dione by the reciprocal action of 1-methyl-5-phenylpropane-1,3-dione and diazonium salt solution of phenyl-chloride interacts with 4-hydroxybenzoic acid hydrazide to form the final compound. These diazoles, the heterocyclic compounds which contained electron withdrawing groups, were screened for analgesic activity by acetic acid induced writing method, and for anti-inflammatory activity carried on carrageenan-induced paw edema. The synthesized substituted Chlorophenylazo-1,2-diazole nucleus exhibited significant anti-bacterial, anti-cancer, anti-inflammatory activity, muscle relaxing and moderate activity in anti-proliferative studies.展开更多
This paper presents the operation of a Multi-agent system (MAS) for the control of a smart grid. The proposed Multi-agent system consists of seven types of agents: Single Smart Grid Controller (SGC), Load Agents (LAGs...This paper presents the operation of a Multi-agent system (MAS) for the control of a smart grid. The proposed Multi-agent system consists of seven types of agents: Single Smart Grid Controller (SGC), Load Agents (LAGs), a Wind Turbine Agent (WTAG), Photo-Voltaic Agents (PVAGs), a Micro-Hydro Turbine Agent (MHTAG), Diesel Agents (DGAGs) and a Battery Agent (BAG). In a smart grid LAGs act as consumers or buyers, WTAG, PVAGs, MHTAG & DGAGs acts as producers or sellers and BAG act as producer/consumer or seller/buyer. The paper demonstrates the use of a Multi-agent system to control the smart grid in a simulated environment. In order to validate the performance of the proposed system, it has been applied to a simple model system with different time zone i.e. day time and night time and when power is available from the grid and when there is power shedding. Simulation results show that the proposed Multi-agent system can perform the operation of the smart grid efficiently.展开更多
Rationale:The mechanism of sudden cardiac death in COVID-19 can be multifactorial.Cardiac hypersensitivity to 5-ASA therapy leading to myocarditis has been reported in some cases.Cytokine storm syndrome and idiosyncra...Rationale:The mechanism of sudden cardiac death in COVID-19 can be multifactorial.Cardiac hypersensitivity to 5-ASA therapy leading to myocarditis has been reported in some cases.Cytokine storm syndrome and idiosyncratic reaction with mesalazine use may lead to sudden cardiac death in COVID-19.Use of immunosuppressants in hospitalized COVID-19 patients should be continued with caution,especially in patients with inflammatory bowel disease.Patient’s concern:A 75-year-old man who was tested positive for SARS-CoV-2 was admitted with a history of shortness of breath for the last two days.He was a known case of Crohn’s disease treated with mesalazine.Diagnosis:COVID-19 pneumonia with underlying Crohn’s disease leading to sudden cardiac death.Intervention:Remdesivir,antibiotics,steroids,low molecular weight heparin,tablet zinc,tab vitamin C,and other supportive treatment were started.Because of increased inflammatory markers,itolizumab was given to the patient on the 2nd day.Outcome:On the 5th day of the intensive care unit,the patient complained of sudden chest pain with respiratory distress leading to bradycardia and asystole and could not be resuscitated.Lessons:Causes for sudden cardiac death in COVID-19 pneumonia patients with Crohn’s disease is multifactorial.Although mesalazine may be a safe and effective drug in the management of inflammatory bowel disease,it can induce sytokine strom syndrome and idiosyncratic reactions that could be one of the reasons of sudden cardic death.Therefore,we should be aware of its serious and potentially life-threatening complications,especially in COVID-19 infected patients.展开更多
This survey paper provides a general overview on Cloud Computing. The topics that are discussed include characteristics, deployment and service models as well drawbacks. Major aspects of Cloud Computing are explained ...This survey paper provides a general overview on Cloud Computing. The topics that are discussed include characteristics, deployment and service models as well drawbacks. Major aspects of Cloud Computing are explained to give the reader a clearer understanding on the complexity of the platform. Following this, several security issues and countermeasures are also discussed to show the major issues and obstacles that Cloud Computing faces as it is being implemented further. The major part of countermeasures focuses on Intrusion Detection Systems. Moving towards Mobile Cloud Computing and Internet of Things, this survey paper gives a general explanation on the applications and potential that comes with the integration of Cloud Computing with any device that has Internet connectivity as well as the challenges that are before it.展开更多
Switch and router architectures employing a shared buffer are known to provide high throughput, low delay, and high memory utilization. Superior performance of a shared-memory switch compared to switches employing oth...Switch and router architectures employing a shared buffer are known to provide high throughput, low delay, and high memory utilization. Superior performance of a shared-memory switch compared to switches employing other buffer strategies can be achieved by carefully implementing a buffer-management scheme. A buffer-sharing policy should allow all of the output interfaces to have fair and robust access to buffer resources. The sliding-window (SW) packet switch is a novel architecture that uses an array of parallel memory modules that are logically shared by all input and output lines to store and process data packets. The innovative aspects of the SW architecture are the approach to accomplishing parallel operation and the simplicity of the control functions. The implementation of a buffer-management scheme in a SW packet switch is dependent on how the buffer space is organized into output queues. This paper presents an efficient SW buffer-management scheme that regulates the sharing of the buffer space. We compare the proposed scheme with previous work under bursty traffic conditions. Also, we explain how the proposed buffer-management scheme can provide quality-of-service (QoS) to different traffic classes.展开更多
During the Distributed Denial of Service (DDoS) attacks, computers are made to attack other computers. Newer Firewalls now days are providing prevention against such attack traffics. McAfee SecurityCenter Firewall is ...During the Distributed Denial of Service (DDoS) attacks, computers are made to attack other computers. Newer Firewalls now days are providing prevention against such attack traffics. McAfee SecurityCenter Firewall is one of the most popular security software installed on millions of Internet connected computers worldwide. “McAfee claims that if you have installed McAfee SecurityCentre with anti-virus and antispyware and Firewall then you always have the most current security to combat the ever-evolving threats on the Internet for the duration of the subscription”. In this paper, we present our findings regarding the effectiveness of McAfee SecurityCentre software against some of the popular Distributed Denial Of Service (DDoS) attacks, namely ARP Flood, Ping-flood, ICMP Land, TCP-SYN Flood and UDP Flood attacks on the computer which has McAfee SecurityCentre installed. The McAfee SecurityCentre software has an in built firewall which can be activated to control and filter the Inbound/Outbound traffic. It can also block the Ping Requests in order to stop or subside the Ping based DDoS Attacks. To test the McAfee Security Centre software, we created the corresponding attack traffic in a controlled lab environment. It was found that the McAfee Firewall software itself was incurring DoS (Denial of Service) by completely exhausting the available memory resources of the host computer during its operation to stop the external DDoS Attacks.展开更多
We have measured trace elements in epileptic patients. Levels of trace elements are very fluctuating in comparison to the healthy controls. The levels of Zn, Fe and Cu are higher in comparison to healthy normal childr...We have measured trace elements in epileptic patients. Levels of trace elements are very fluctuating in comparison to the healthy controls. The levels of Zn, Fe and Cu are higher in comparison to healthy normal children about 64%, 55% and 33% respectively. The levels of Cu are just fifty percent to levels of Zn. The levels of Ca, K and Mg are higher about 10%, 9.027% and 4.2% in comparison to normal children. Sodium levels were very low in comparison to all the trace elements and are higher about 3.2% than controls. The multiple correlation coefficients between Na, K and Ca, i.e. (RNa.KCa) has a value 0.4993 in comparison to healthy children. Multiple correlation coefficients between Fe, Cu and Zn, i.e. (RFe.CuZn) has a value 0.4366. The multiple correlation coefficients RNa.Kca and?RFe.CuZn are found lower. These elements were strongly correlated with other. The multiple correlation coefficients such as RK.NaCa, RCa.K.Na, RMg.NaK, RNa.MgK, RK.MgNa, RCu.FeZn and RZn.FeCu were also evaluated and found on higher side from normal range. Trace elements may act as a catalytic agent for enzyme system of the cells. The minimum requirements of living objects for essential trace elements may be expressed in proportions or concentrations of the total dry food taken everyday. A tolerance of the human system may be fluctuated according to intake of these elements.展开更多
Distributed Denial of Service (DDoS) is known to compromise availability of Information Systems today. Widely deployed Microsoft’s Windows 2003 & 2008 servers provide some built-in protection against common Distr...Distributed Denial of Service (DDoS) is known to compromise availability of Information Systems today. Widely deployed Microsoft’s Windows 2003 & 2008 servers provide some built-in protection against common Distributed Denial of Service (DDoS) attacks, such as TCP/SYN attack. In this paper, we evaluate the performance of built-in protection capabilities of Windows servers 2003 & 2008 against a special case of TCP/SYN based DDoS attack. Based on our measurements, it was found that the built-in security features which are available by default on Microsoft’s Windows servers were not sufficient in defending against the TCP/SYN attacks even at low intensity attack traffic. Under TCP/SYN attack traffic, the Microsoft 2003 server was found to crash due to processor resource exhaustion, whereas the 2008 server was found to crash due to its memory resource depletion even at low intensity attack traffic.展开更多
文摘AIM:To identify optimum timing to maximize diagnostic yield by capsule endoscopy (CE) in patients with obscure gastrointestinal bleeding (OGIB).METHODS:We identified patients who underwent CE at our institution from August 2003 to December 2009.Patient medical records were reviewed to determine type of OGIB (occult,overt),CE results and complications,and timing of CE with respect to onset of bleeding.RESULTS:Out of 385 patients investigated for OGIB,284 (74%) had some lesion detected by CE.In 222 patients (58%),definite lesions were detected that could unequivocally explain OGIB.Small bowel ulcer/erosions secondary to Crohn's disease,tuberculosis or non-steroidal anti-inflammatory agent use were the commonest lesions detected.Patients with overt GI bleeding for < 48 h before CE had the highest diagnostic yield (87%).This was significantly greater (P < 0.05) compared to that in patients with overt bleeding prior to 48 h (68%),as well as those with occult OGIB (59%).CONCLUSION:We established the importance of early CE in management of OGIB.CE within 48 h of overt bleeding has the greatest potential for lesion detection.
文摘The evolution in communication techniques has created wide threats for crucial information transfer through a communication channel. Covert communication with steganography is a skill of concealing secret information within cover object and hence shields the data theft over rapidly growing network.Recently, diverse steganography techniques using edge identification have been proposed in literature.Numerous methods however utilize certain pixels in the cover image for inserting edge information,resulting in significant deformation. The conventional edge detection method limits the deployment of edge detection in steganography as concealing the information would introduce some variations to the cover image. Hence inserting data in pixel areas recognized by existing conventional edge detection techniques like canny cannot ensure the recognition of the exact edge locations for the cover and stego images. In this paper, an Adaptive steganography method based on novel fuzzy edge identification is proposed. The method proposed is proficient of estimating the precise edge areas of a cover image and also ensures the exact edge location after embedding the secret message. Experimental results reveal that the technique has attained good imperceptibility compared to the Hayat AI-Dmour and Ahmed AIAni Edge XOR method in spatial domain.
文摘Natural fibre-reinforced composites are now becoming incredibly common in various products because of their comparable qualities to conventional materials.Due to its availability,superior mechanical qualities,and low cost,banana pseudostem is extensively used in various applications requiring natural fibres.This study investigates the physical and mechanical properties of epoxy composites reinforced with banana pseudostem fibres that contain Al_(2)O_(3) particulate.In order to produce composites with fibre and filler loadings,manual hand layup was used.Fibre and filler loading effects on composite properties were studied in experiments.The results of the investigations demonstrate that proportion of Al_(2)O_(3) in composites significantly influences their mechanical and physical properties.Additionally,the composite with a fibre content of 30%shows improved mechanical proportions and hardness.Thermogravimetric analysis was used to study the composite's thermal behaviour.Composites are more thermally stable than raw epoxy.Fourier Transform Infrared Spectroscopy and Scanning electron microscopy analyses were used to characterize the composites.
文摘In cryptography, the Triple DES (3DES, TDES or officially TDEA) is a symmetric-key block cipher which applies the Data Encryption Standard (DES) cipher algorithm three times to each data block. Electronic payment systems are known to use the TDES scheme for the encryption/decryption of data, and hence faster implementations are of great significance. Field Programmable Gate Arrays (FPGAs) offer a new solution for optimizing the performance of applications meanwhile the Triple Data Encryption Standard (TDES) offers a mean to secure information. In this paper we present a pipelined implementation in VHDL, in Electronic Code Book (EBC) mode, of this commonly used cryptography scheme with aim to improve performance. We achieve a 48-stage pipeline depth by implementing a TDES key buffer and right rotations in the DES decryption key scheduler. Using the Altera Cyclone II FPGA as our platform, we design and verify the implementation with the EDA tools provided by Altera. We gather cost and throughput information from the synthesis and timing results and compare the performance of our design to common implementations presented in other literatures. Our design achieves a throughput of 3.2 Gbps with a 50 MHz clock;a performance increase of up to 16 times.
基金This research received no specific grant from any funding agency in the public,commercial,or not-for-profit sectors。
文摘Background:The purpose of the study is to understand the role of cash flow sensitivity to investment as a measure of financial constraints among listed Indian manufacturing firms.It also analyses the role of tangibility in alleviating financial constraints.Further,the role of other financial factors in investment decisions is explored.Methods:The study is conducted using the generalized method of moments(GMM)estimator on dynamic panel data for the period of(2009–2015)on 768 listed manufacturing firms.Results:The analysis finds that cash flow sensitivity is a valid measure of financial constraints in the Indian manufacturing sector.Results according to splitting criteria found that investment decisions of standalone firms are more sensitive to cash flow than group affiliated firms.Further,splitting the firms according to market capitalization and tangible net worth reveals a higher degree of cash flow sensitivity by firms with lower market capitalization and asset tangibility.The results for the effects of tangibility of assets on easing financial constraint were found significant only in the case of firms with low tangible net worth and medium market capitalization.Conclusions:The study confirms cash flow sensitivity to investment as a valid measure of financial constraints.It will confirm pooling of internal funds by financially constrained firms to accept profitable investment opportunities in future.Further,it also reports that asset tangibility eases the financial constraints faced by firms.
文摘With the increase in the number of computers connected to Internet, the number of Distributed Denial of Service (DDoS) attacks has also been increasing. A DDoS attack consumes the computing resources of a computer or a server, by degrading its computing performance or by preventing legitimate users from accessing its services. Recently, Operating Systems (OS) are increasingly deploying embedded DDoS prevention schemes to prevent computing exhaustion caused by such attacks. In this paper, we compare the effectiveness of two popular operating systems, namely the Apple’s Lion and Microsoft’s Windows 7, against DDoS attacks. We compare the computing performance of these operating systems under two ICMP based DDoS attacks. Since the role of the OS is to manage the computer or servers resources as efficiently as possible, in this paper we investigate which OS manages its computing resources more efficiently. In this paper, we evaluate and compare the built-in security of these two operating systems by using an iMac computer which is capable of running both Windows 7 and Lion. The DDoS attacks that are simulated for this paper are the ICMP Ping and Land Attack. For this experiment, we measure the exhaustion of the processors and the number of Echo Request and Echo Reply messages that were generated under varying attack loads for both the Ping and Land Attack. From our experiments, we found that both operating systems were able to survive the attacks however they reacted a bit differently under attack. The Operating System Lion was handling both the Ping and Land attack in the exactly the same way, whereas Windows 7 handled the two attacks a bit differently, resulting in different processor consumptions by two different operating systems.
文摘ARP-based Distributed Denial of Service (DDoS) attacks due to ARP-storms can happen in local area networks where many computer systems are infected by worms such as Code Red or by DDoS agents. In ARP attack, the DDoS agents constantly send a barrage of ARP requests to the gateway, or to a victim computer within the same sub-network, and tie up the resource of attacked gateway or host. In this paper, we set to measure the impact of ARP-attack on resource exhaustion of computers in a local area network. Based on attack experiments, we measure the exhaustion of processing and memory resources of a victim computer and also other computers, which are located on the same network as the victim computer. Interestingly enough, it is observed that an ARP-attack not only exhausts resource of the victim computer but also significantly exhausts processing resource of other non-victim computers, which happen to be located on the same local area network as the victim computer.
文摘Cyber attacks are continuing to hamper working of Internet services despite increased use of network secu-rity systems such as firewalls and Intrusion protection systems (IPS). Recent Distributed Denial of Service (DDoS) attacks on Dec 8th, 2010 by Wikileak supporters on Visa and Master Card websites made headlines on prime news channels all over the world. Another famous DDoS attacks on Independence Day weekend, on July 4th, 2009 were launched to debilitate the US and South Korean governments’ websites. These attacks raised questions about the capabilities of the security systems that were used in the network to counteract such attacks. Firewall and IPS security systems are commonly used today as a front line defense mechanism to defend against DDoS attacks. In many deployments, performances of these security devices are seldom evaluated for their effectiveness. Different security devices perform differently in stopping DDoS attacks. In this paper, we intend to drive the point that it is important to evaluate the capability of Firewall or IPS secu-rity devices before they are deployed to protect a network or a server against DDoS attacks. In this paper, we evaluate the effectiveness of a security device called Netscreen 5GT (or NS-5GT) from Juniper Networks under Layer-4 flood attacks at different attack loads. This security device NS-5GT comes with a feature called TCP-SYN proxy protection to protect against TCP-SYN based DDoS attacks, and UDP protection feature to protect against UDP flood attacks. By looking at these security features from the equipments data sheet, one might assume the device to protect the network against such DDoS attacks. In this paper, we con-ducted real experiments to measure the performance of this security device NS-5GT under the TCP SYN and UDP flood attacks and test the performance of these protection features. It was found that the Juniper’s NS-5GT mitigated the effect of DDoS traffic to some extent especially when the attack of lower intensity. However, the device was unable to provide any protection against Layer4 flood attacks when the load ex-ceeded 40Mbps. In order to guarantee a measured level of security, it is important for the network managers to measure the actual capabilities of a security device, using real attack traffic, before they are deployed to protect a critical information infrastructure.
文摘Muscular dystrophies are myopathies and tend to progressive, with ongoing degeneration and regeneration of muscle fibers. Spinal muscular atrophy (SMA), amyotrophic lateral sclerosis (ALS) and polio myelitis are essentially diseases of the anterior horn cells of the spine. It has been reported in literature that humoral immunity is manifested by the antibodies production. These are special chemical substances that react against foreign body. Antibodies are serum proteins, which are immunoglobulins and possess antibody activity and are classified according to antigens and stimulate their production such as IgA, JgG, IgM, IgD and IgE. All the immunological parameters such as of C3, C4, IgG, IgM and IgA, which are measured in Duchenne muscular dystrophy go down in comparison to healthy subjects. Complement C3 and Complement C4 go down about 44.3% and 78.57% respectively from the normal values. The serum IgG, IgM and IgA levels were also go down about 65%, 84% and 99.56% respectively in comparison to healthy subjects. A trend between all the immunoglobulins has been set up and it is rAG.M > rMA.G. > rGM.A, while we have a trend in DMD cases is rMA.G. > rAG.M > rGM.A We are in a position to say that our data have a relevance of high authenticity and reliability to accept that there is a deficit in immunity in DMD cases. The deficit in immunity may be a cause to damage muscle for abnormal functioning.
基金the Department of Space,Government of India,India,under ISRO-GBP program。
文摘Change in land-use practices can result in major shifts in the cycling of various elements,particularly nitrogen(N),which is prone to anthropogenic perturbations.For quantifying these shifts,accurate measurements of rates of biogeochemical transformations of N are needed.We used the(^(15)N) isotope dilution technique to understand the effects of the types of forest alteration on(N) transformation rates by comparing gross N mineralization and ammonium(NH_(4)^(+)) consumption rates in soils of a managed forest,an unmanaged forest,and a rubber plantation in Kerala,India.Overall,nitrate(NO_3~-) dominated soils of the managed and unmanaged forests,whereas soils in the rubber plantation showed relatively higher NH_(4)^(+) concentration.Total N(TN) and total organic carbon(TOC) concentrations were the highest under the rubber canopy(TN:1.49±0.02 mg N g^(-1);TOC:7.96±0.86 mg C g^(-1)).In soils of all three forest types,gross N mineralization rates were higher compared to NH_(4)^(+) consumption rates.Despite high TN and TOC concentrations,the rates of gross N mineralization and NH_(4)^(+) consumption were considerably lower in the rubber plantation(mineralization:1.08±0.08 mg N kg^(-1)d^(-1);consumption:0.85±0.09 mg N kg^(-1) d^(-)) compared to the managed(mineralization:3.71±0.35 mg N kg^(-1) d^(-1);consumption:2.20±1.41 mg N kg^(-1) d^(-1)) and unmanaged(mineralization:2.20±1.07 mg N kg^(-1) d^(-1);consumption:1.39±0.27 mg N kg^(-1) d^(-1)) forests.The lower NH_(4)^(+) consumption rates in the rubber plantation led to significantly higher(p<0.05) residence time of NH_(4)^(+)(~4 days) compared to the managed and unmanaged forests(<2 days),possibly contributing to acidification of rubber soils(pH~4.8).These results together suggest that replacement of naturally grown forests with a mono-cropped plantation such as rubber negatively impact rates of N transformation processes in tropical soils and imply that change in tree species composition of naturally grown forests can adversely affect soil microbial activity.We recommend intercropping these plantations with commercial crops to maintain soil microbial diversity and biogeochemical cycling for sustainable forest management.
文摘In this paper, we present and analyze modified families of predictor-corrector iterative methods for finding simple zeros of univariate nonlinear equations, permitting near the root. The main advantage of our methods is that they perform better and moreover, have the same efficiency indices as that of existing multipoint iterative methods. Furthermore, the convergence analysis of the new methods is discussed and several examples are given to illustrate their efficiency.
文摘A series of sulpha/substituted derivatives of phenyl azo-1,2-diazole have been synthesized and tested as an anti-inflammatory and anti-bacterial activity in mature albino rats hind paw by taking Diclofenac sodium as standard. N1-(4-hydroxy benzoyl)-3-methyl-5-phenyl-4(N-4-chlorophenylazo)-1,2-diazole is synthesized by a two-step process. In the first step, synthesis of N1-4-chlorophenyl hydrazono-1-methyl-3-phenyl propane-1,3-dione by the reciprocal action of 1-methyl-5-phenylpropane-1,3-dione and diazonium salt solution of phenyl-chloride interacts with 4-hydroxybenzoic acid hydrazide to form the final compound. These diazoles, the heterocyclic compounds which contained electron withdrawing groups, were screened for analgesic activity by acetic acid induced writing method, and for anti-inflammatory activity carried on carrageenan-induced paw edema. The synthesized substituted Chlorophenylazo-1,2-diazole nucleus exhibited significant anti-bacterial, anti-cancer, anti-inflammatory activity, muscle relaxing and moderate activity in anti-proliferative studies.
文摘This paper presents the operation of a Multi-agent system (MAS) for the control of a smart grid. The proposed Multi-agent system consists of seven types of agents: Single Smart Grid Controller (SGC), Load Agents (LAGs), a Wind Turbine Agent (WTAG), Photo-Voltaic Agents (PVAGs), a Micro-Hydro Turbine Agent (MHTAG), Diesel Agents (DGAGs) and a Battery Agent (BAG). In a smart grid LAGs act as consumers or buyers, WTAG, PVAGs, MHTAG & DGAGs acts as producers or sellers and BAG act as producer/consumer or seller/buyer. The paper demonstrates the use of a Multi-agent system to control the smart grid in a simulated environment. In order to validate the performance of the proposed system, it has been applied to a simple model system with different time zone i.e. day time and night time and when power is available from the grid and when there is power shedding. Simulation results show that the proposed Multi-agent system can perform the operation of the smart grid efficiently.
文摘Rationale:The mechanism of sudden cardiac death in COVID-19 can be multifactorial.Cardiac hypersensitivity to 5-ASA therapy leading to myocarditis has been reported in some cases.Cytokine storm syndrome and idiosyncratic reaction with mesalazine use may lead to sudden cardiac death in COVID-19.Use of immunosuppressants in hospitalized COVID-19 patients should be continued with caution,especially in patients with inflammatory bowel disease.Patient’s concern:A 75-year-old man who was tested positive for SARS-CoV-2 was admitted with a history of shortness of breath for the last two days.He was a known case of Crohn’s disease treated with mesalazine.Diagnosis:COVID-19 pneumonia with underlying Crohn’s disease leading to sudden cardiac death.Intervention:Remdesivir,antibiotics,steroids,low molecular weight heparin,tablet zinc,tab vitamin C,and other supportive treatment were started.Because of increased inflammatory markers,itolizumab was given to the patient on the 2nd day.Outcome:On the 5th day of the intensive care unit,the patient complained of sudden chest pain with respiratory distress leading to bradycardia and asystole and could not be resuscitated.Lessons:Causes for sudden cardiac death in COVID-19 pneumonia patients with Crohn’s disease is multifactorial.Although mesalazine may be a safe and effective drug in the management of inflammatory bowel disease,it can induce sytokine strom syndrome and idiosyncratic reactions that could be one of the reasons of sudden cardic death.Therefore,we should be aware of its serious and potentially life-threatening complications,especially in COVID-19 infected patients.
文摘This survey paper provides a general overview on Cloud Computing. The topics that are discussed include characteristics, deployment and service models as well drawbacks. Major aspects of Cloud Computing are explained to give the reader a clearer understanding on the complexity of the platform. Following this, several security issues and countermeasures are also discussed to show the major issues and obstacles that Cloud Computing faces as it is being implemented further. The major part of countermeasures focuses on Intrusion Detection Systems. Moving towards Mobile Cloud Computing and Internet of Things, this survey paper gives a general explanation on the applications and potential that comes with the integration of Cloud Computing with any device that has Internet connectivity as well as the challenges that are before it.
文摘Switch and router architectures employing a shared buffer are known to provide high throughput, low delay, and high memory utilization. Superior performance of a shared-memory switch compared to switches employing other buffer strategies can be achieved by carefully implementing a buffer-management scheme. A buffer-sharing policy should allow all of the output interfaces to have fair and robust access to buffer resources. The sliding-window (SW) packet switch is a novel architecture that uses an array of parallel memory modules that are logically shared by all input and output lines to store and process data packets. The innovative aspects of the SW architecture are the approach to accomplishing parallel operation and the simplicity of the control functions. The implementation of a buffer-management scheme in a SW packet switch is dependent on how the buffer space is organized into output queues. This paper presents an efficient SW buffer-management scheme that regulates the sharing of the buffer space. We compare the proposed scheme with previous work under bursty traffic conditions. Also, we explain how the proposed buffer-management scheme can provide quality-of-service (QoS) to different traffic classes.
文摘During the Distributed Denial of Service (DDoS) attacks, computers are made to attack other computers. Newer Firewalls now days are providing prevention against such attack traffics. McAfee SecurityCenter Firewall is one of the most popular security software installed on millions of Internet connected computers worldwide. “McAfee claims that if you have installed McAfee SecurityCentre with anti-virus and antispyware and Firewall then you always have the most current security to combat the ever-evolving threats on the Internet for the duration of the subscription”. In this paper, we present our findings regarding the effectiveness of McAfee SecurityCentre software against some of the popular Distributed Denial Of Service (DDoS) attacks, namely ARP Flood, Ping-flood, ICMP Land, TCP-SYN Flood and UDP Flood attacks on the computer which has McAfee SecurityCentre installed. The McAfee SecurityCentre software has an in built firewall which can be activated to control and filter the Inbound/Outbound traffic. It can also block the Ping Requests in order to stop or subside the Ping based DDoS Attacks. To test the McAfee Security Centre software, we created the corresponding attack traffic in a controlled lab environment. It was found that the McAfee Firewall software itself was incurring DoS (Denial of Service) by completely exhausting the available memory resources of the host computer during its operation to stop the external DDoS Attacks.
文摘We have measured trace elements in epileptic patients. Levels of trace elements are very fluctuating in comparison to the healthy controls. The levels of Zn, Fe and Cu are higher in comparison to healthy normal children about 64%, 55% and 33% respectively. The levels of Cu are just fifty percent to levels of Zn. The levels of Ca, K and Mg are higher about 10%, 9.027% and 4.2% in comparison to normal children. Sodium levels were very low in comparison to all the trace elements and are higher about 3.2% than controls. The multiple correlation coefficients between Na, K and Ca, i.e. (RNa.KCa) has a value 0.4993 in comparison to healthy children. Multiple correlation coefficients between Fe, Cu and Zn, i.e. (RFe.CuZn) has a value 0.4366. The multiple correlation coefficients RNa.Kca and?RFe.CuZn are found lower. These elements were strongly correlated with other. The multiple correlation coefficients such as RK.NaCa, RCa.K.Na, RMg.NaK, RNa.MgK, RK.MgNa, RCu.FeZn and RZn.FeCu were also evaluated and found on higher side from normal range. Trace elements may act as a catalytic agent for enzyme system of the cells. The minimum requirements of living objects for essential trace elements may be expressed in proportions or concentrations of the total dry food taken everyday. A tolerance of the human system may be fluctuated according to intake of these elements.
文摘Distributed Denial of Service (DDoS) is known to compromise availability of Information Systems today. Widely deployed Microsoft’s Windows 2003 & 2008 servers provide some built-in protection against common Distributed Denial of Service (DDoS) attacks, such as TCP/SYN attack. In this paper, we evaluate the performance of built-in protection capabilities of Windows servers 2003 & 2008 against a special case of TCP/SYN based DDoS attack. Based on our measurements, it was found that the built-in security features which are available by default on Microsoft’s Windows servers were not sufficient in defending against the TCP/SYN attacks even at low intensity attack traffic. Under TCP/SYN attack traffic, the Microsoft 2003 server was found to crash due to processor resource exhaustion, whereas the 2008 server was found to crash due to its memory resource depletion even at low intensity attack traffic.
