Design and Implementation of Faster and Low Power Multipliers

A multiplier is one of the key hardware blocks in most digital and high performance systems such as FIR filters, digital signal processors and microprocessors etc. With advances in technology, many researchers have tried and are trying to design multipliers which offer either of the following- high speed, low power consumption, regularity of layout and hence less area or even combination of them in multiplier. Thus making them suitable for various high speed, low power, and compact VLSI implementations. However area and speed are two conflicting constraints. So improving speed results always in larger areas. So here we try to find out the best trade off solution among the both of them. Generally as we know multiplication goes in two basic steps. Partial product and then addition. Hence in this paper we have first tried to design different adders and compare their speed and complexity of circuit i.e. the area occupied. And then we have designed Wallace tree multiplier then followed by Booth’s Wallace multiplier and have compared the speed and Power consumption in them. While comparing the adders we found out that Ripple Carry Adder had a smaller area while having lesser speed, in contrast to which Carry Select Adders are high speed but posses a larger area. And a Carry Look Ahead Adder is in between the spectrum having a proper trade off between time and area complexities. After designing and comparing the adders we turned to multipliers. Initially we went for Parallel Multiplier and then Wallace Tree Multiplier. In the mean time we learned that delay amount was considerably reduced when Carry Save Adders were used in Wallace Tree applications. Then we turned to Booths Multiplier and designed Radix-4 modified booth multiplier and analyzed the performance of all the multipliers. After that we turned to different methods of power optimization, of which we could only complete a few like we went for designing different recoding schemes and their corresponding partial product generator scheme. After that we designed these recoders and PP generators and found out the time delays and area covered and power consumed by each scheme. We took into consideration that since all the PP generators take a huge amount of area we need to go for simplest of the designs for them and also side by side we need to ensure that we don’t have much switching actions in the circuit. After this we even modified one of the recoding schemes to lower the delay and power required by the circuit. The result of our project helps us to make a proper choice of different multipliers in fabricating in different arithmetic units as well as making a choice among different adders in different digital applications according to requirements. All the programs and results have been given in the following sections. Further work on Low Power Techniques on different multipliers needs to be done in order to make us choose a proper multiplier in accordance with the requirements by making the best possible trade off choice between Speed and Power in different circumstances

AGRICULTURE AND BIOLOGY JOURNAL OF NORTH AMERICA Development of species specific primer for the early detection of Cylindrocladium quinqueseptatum causing leaf and seedling blight in Eucalyptus

ABSTRACT We developed PCR primers to detect Cylindrocladium quinqueseptatum which infect Eucalyptus causing leaf and seedling blight resulting in heavy seedling mortality in North Indian states. Primers based on sequence analysis of internal transcribed spacer region 1 and 5.8S of ribosomal DNA produced PCR product of 245bp. The internal transcribed spacer (ITS) of the ribosomal DNA (rDNA) sub unit repeat was sequenced in 26 isolates of Cylindrocladium quinqueseptatum and sequences were aligned and compared with the ITS sequences of other fungi in GenBank. No amplification resulted from PCR reactions on fungal DNA from 6 common forest fungi, 10 soil contaminates and 6 Eucalyptus pathogens. For amplifications directly from infected tissues, a nested primer PCR using two rounds of amplification was done. First, the entire ITS was amplified with universal fungal primer; a second round of amplification was carried out with species specific primer that amplified a 245 bp PCR product. The method detected leaf and seedling blight in artificially and naturally infected Eucalyptus plants. From the soil also the pathogen was detected using species specific primer. In sampling studies, C. quinqueseptatum was detected by PCR from artificially infected seedlings at 6 days post inoculation, before any visible symptoms were present. The PCR assay and direct tissue extraction methods provide tools which may be used to detect C. quinqueseptatum from soil, plant cuttings and adjoining Eucalyptus plantations serving as recurring source of infection and thus limit the transmission and spread of new aggressive strains of C. quinqueseptatum in Eucalyptus growing regions of India

Bioinformatics tools for genomic and evolutionary analysis of infectious agents

Genome sequence analysis of infectious agents (IAs) reveals many secrets about their life processes and evolutionary history. Increasing the huge amount of genomic sequence data of various IAs in different biological sequence databases, which are being produced through different sequencing projects, is continuously motivating the genome researchers to unlock the mysteries related to the life of IAs. Furthermore, that information may be helpful for treating the serious illness problem caused by IAs. However, all the genome analysis work requires a good knowledge of bioinformatics tools that may be useful for genome researchers to extract the meaningful and accurate information from the genome sequence data of IAs. In this article, the most recent bioinformatics tools for the genomic and evolutionary analysis of infectious agents have been discussed and compared in detail which will help the genome researchers to select the most appropriate tool for genomic and evolutionary analysis of IAs

Challenges beyond elimination in leprosy

Every year >200,000 new leprosy cases are registered globally. This number has been fairly stable over the past 8 years. The World Health Organization has set a target to interrupt the transmission of leprosy globally by 2020. It is important, in terms of global action and research activities, to consider the eventuality of multidrug therapy (MDT) resistance developing. It is necessary to measure disease burden comprehensively, and contact-centered preventive interventions should be part of a global elimination strategy. Drug resistance is the reduction in effectiveness of a drug such as an antimicrobial or an antineoplastic in curing a disease or condition. MDT has proven to be a powerful tool in the control of leprosy, especially when patients report early and start prompt treatment. Adherence to and its successful completion is equally important. This paper has reviewed the current state of leprosy worldwide and discussed the challenges and also emphasizes the challenge beyond the elimination in leprosy

Microsatellite typing of Mycobacterium leprae strains in newly diagnosed multibacillary leprosy patients to trace out the transmission pattern

Background: Leprosy was eliminated from India in December 2005 imprinting a prevalence rate of <1/10,000 population. Still some endemic pockets exist in India where the new cases of leprosy continue to occur at a constant rate. It means the active transmission of leprosy is still continuing. In the present study, we aimed to elucidate the transmission pattern of Mycobacterium leprae using three microsatellite loci. Methods: Slit-skin samples from 36 newly diagnosed multi-bacillary leprosy cases from Ghatampur, Kanpur Nagar, Uttar Pradesh, India, were collected in a sterile centrifuge tube containing Tris-EDTA (TE) buffer. DNA was isolated, and the microsatellite loci, namely, (GT)6, (TA)18, and (TA)8CA3 were amplified using the in-house designed primers. The amplified products were recovered through polymerase chain reaction cleanup kit and sequenced by Sangers method in a 16 capillary genetic analyzer. Results: Sequences were searched by Basic Local Alignment Search Tool, and phylogenetic analysis was done to trace out the transmission pattern of M. leprae. Out of the three microsatellite loci, (TA)18 was unable to define the transmission pattern while (GT)6 and (TA)8CA3 were endowed with distinct signature for transmission of M. leprae in the study segment of the population. Conclusions: We found that nine types of M. leprae strains were circulating in the Ghatampur area and the same type of strains were found in the same villages or in neighboring villages. To conclude the study, we accentuated that (TA)8CA3 is a better microsatellite locus for strain typing of M. leprae

Multiple strain infection of Mycobacterium leprae in a family having 4 patients: A study employing short tandem repeats.

BackgroundLeprosy is a slow, chronic disorder caused by Mycobacterium leprae. India has achieved elimination of leprosy in December 2005 but new cases are being detected and continue to occur in some endemic pockets. The possible ways of transmission of leprosy is not fully understood and is believed that leprosy is transmitted from person to person in long term contact. Studying the transmission dynamics is further complicated by inability to grow M. leprae in culture medium and lack of animal models. More than one family members were found to be affected by leprosy in some highly endemic pockets. This study reported the transmission pattern of leprosy in a family having 4 patients.Methodology/principal findingsWe investigated the transmission of leprosy in a single family having 4 patients using microsatellite typing. DNA was isolated from slit skin smear samples taken from the patients and the isolated DNA were amplified using microsatellite loci TA11CA3. The amplified products were sequenced using Sanger's sequencing methods and the copy number variation in the microsatellite loci between strains were elucidated by multiple sequence alignment. The result showed that all the 4 members of the family acquired infection from 3 different strains of M. leprae from 3 different sources. The elder and middle daughters were infected by same types of strains having the repeat unit TA13CA3 and could have acquired the infection from social contacts of leprosy cases while the father and younger daughter were infected by strains with the repeat unit TA12CA3 and TA11CA3 and could have acquired infection from social contacts.Conclusions/significanceThe study suggested that three family members viz, elder daughter, father and younger daughter could be infected by M. leprae from 3 different sources and the history of the disease and genetic analysis showed that the middle daughter acquired infection from her elder sister in due course of contact. This study implies that the transmission of leprosy not only occurred amongst the house hold members but also has been transmitted from social and neighborhood contacts in long term association with the them