Review of high-speed phase accumulator for direct digital frequency synthesizer

A review of high-speed pipelined phase accumulator (PA) is proposed in this paper. The detail explanation of ideas, methods and techniques used in previous researches to improve the PA throughput designs were surveyed. The Brent–Kung (BK) adder was modified in this paper to be applied in pipelined PA architecture. A comparison of different adder circuits, includes a modified BK, ripple carry adder (RCA), Kogge-Stone adder (KS) and other prefix adders were applied to architect the PA based on Pipeline technique. The presented pipelined PA design circuit with multiple frequency control word (FCW) and different adders were coded Verilog hardware description language (HDL) code, compiled and verified with field programmable gate array (FPGA) kit platform. The comparison result shows that the modified BK adder has fast performances. The shifted clocking technique is utilized in the proposed pipelined PA circuit to reduce the unwanted repetitive D-flip flop (DFF) registers (coming from the pipeline technique), while preserving the high speed

Differentiation of Entamoeba histolytica, Entamoeba dispar and Entamoeba moshkovskii from diarrhoeic stools using Polymerase Chain Reaction in Kaduna, Nigeria

Background: Entamoeba species have been reported to cause a high morbidity and mortality rate. Aim: The study was aimed at detecting and differentiating E. histolytica, E. dispar and E. moshkovskii using molecular technique (PCR).Methods: Microscopic examination of the faecal samples was carried out by the Formol-Ether concentration technique. DNA was extracted from microscopic positive stool samples and used to amplify a part of the genus Entamoeba small-subunit ribosomal RNA gene (SSU rDNA), using the Nested Multiplex Polymerase Chain Reaction (NM-PCR).Results: Of the 528 faecal samples, 46 (8.7%) were positive for Entamoeba by microscopy. The PCR results showed that out of the 46 microscopy positive samples, 16 (34.8%) successfully generated species-specific amplicons of Entamoeba species DNA. The infection with E. dispar (68.8%; 11/46) was the most common, followed by E. histolytica (37.5%; 6/46) and E. moshkovskii (18.8%; 3/46). Of these, 7 (43.8%) were shown to contain only E. dispar, 3 (18.8%) contained only E. histolytica and 2 (12.5%) contained only E. moshkovskii. Mixed infection with E. histolytica and E. dispar was found in 3 (18.8%) and E. dispar and E. moshkovskii in 1 (6.3%) sample.Conclusion: This study therefore highlighted the great importance of the use of molecular techniques to differentiate between E. histolytica, E. dispar and E. moshkovskii because it obviates unnecessary chemotherapy with possible costs, side effects and drug resistance. The use of PCR in the diagnosis of amoebiasis and epidemiological survey in Nigeria is thus recommended.Keywords: Entamoeba histolytica, Entamoeba dispar, Entamoeba moshkovskii, DNA, Polymerase Chain Reaction, amoebiasi

Institutional Overlap and Power Relations in Private-Led Regularization Projects in Informal Settlements: The case of Gairo Town, Morogoro

In the early 1990s to date, the private sector has continued to gain momentum in urban planning and service delivery. Among others, the penetration of neo-liberal ideology in policies and legislations empowered the engagement of private sector in urban planning domain. Subsequently many private firms have dominated the process of the preparation of details schemes including regularization of informal settlements in different cities, municipalities and towns in Tanzania. However, the institutional overlap and power relation and approach used by the private sector at the grassroot levels to mobilize resources to meet the cost of regularization of informal settlements are rarely documented and discussed. This paper uses the case of Gairo Town regularization project to illuminate on the existing institutions, actors and power relation in the private-lead regularization projects and approach used to engage the community in financing the preparation of regularization schemes. Through household surveys, official and key informant interviews, observations and mapping, steps followed by the private firms to acquire the projects from the Planning Authority to the community levels were documented and analyzed. The findings show that when there are mutually beneficial interactions among private sector, politicians and grassroots institutions, the community contributes their financial resources to prepare regularization schemes of their settlements. The institutional overlap in terms of multiple allocation of actors in different institutional levels and power relations facilitate the resource mobilization for regularization projects in the informal settlements.

Link Prediction in Complex Networks: A Survey

Link prediction in complex networks has attracted increasing attention from both physical and computer science communities. The algorithms can be used to extract missing information, identify spurious interactions, evaluate network evolving mechanisms, and so on. This article summaries recent progress about link prediction algorithms, emphasizing on the contributions from physical perspectives and approaches, such as the random-walk-based methods and the maximum likelihood methods. We also introduce three typical applications: reconstruction of networks, evaluation of network evolving mechanism and classification of partially labelled networks. Finally, we introduce some applications and outline future challenges of link prediction algorithms.Comment: 44 pages, 5 figure

Microalgae production in fresh market wastewater and its utilization as a protein substitute in formulated fish feed for oreochromis spp.

Rapid growing of human population has led to increasing demand of aquaculture production. Oreochromis niloticus or known as tilapia is one of the most globally cultured freshwater fish due to its great adaptation towards extreme environment. Besides, farming of tilapia not only involves small scales farming for local consumption but also larger scales for international market which contributes to a foreign currency earning. Extensive use of fishmeal as feed for fish and for other animals indirectly caused an increasing depletion of the natural resource and may consequently cause economic and environmental unstable. Microalgae biomass seems to be a promising feedstock in aquaculture industry. It can be used for many purposes such as live food for fish larvae and dried microalgae to substitute protein material in fish feed. The microalgae replacement in fish feed formulation as protein alternative seem potentially beneficial for long term aqua-business sustainability. The present chapter discussed the potential of microalgae as an alternative nutrition in fish feed formulations, specifically Tilapia

An overview of artificial nutrition in apiculture

Artificial nutrition in apiculture is a long-term subject of discussion and investigation. The maintenance and boosting of bee colonies in apiculture depends on synthetic food around the globe to overcome the suppressing factors, including dearth periods. The information on types of food components and their combinations used is haphazard and hardly helpful in determining the advancements in the artificial feeding of bees. This study aimed to extract the available information on artificial feeding on honeybees and arrange it most scientifically. The information in the form of research or review articles available on every platform, viz., soft portals, printed journals, books and scientific proceedings, were collected and analyzed to produce a comprehensive and informative review article on the artificial nutrients in apiculture. Compilation of the available information revealed that artificial feeding of bees depends on food components and their combinations. Based on this, it can be suggested that nectar and pollen are basic foods of honey bees, and based on this, the food components were further categorized as nectar supplements and pollen supplements. These supplements were fed to bees as natural nutrients and food components. The natural nutrients include proteins, carbohydrates, vitamins, yeasts, antibiotics, amino acids, enzymes, antioxidants, etc. Meanwhile, under natural food components, cereal grains, pulses, beans, fruits, vegetables, medicinal plants, spices, condiments, and some non-traditional/ miscellaneous kinds of stuff have been included in the bee diets. On the other hand, many diet categories have been prepared using the abovementioned nutrients and food components in various forms and proportions. In general, the pollen and nectar, the main food of bees, have been supplemented under different diet combinations. These diet combinations used pollen and nectar substitutes or combined with other nutrition, drugs, antibiotics, etc. The present investigation provides an updated overview of the food categories and their combinations used in the artificial feeding of bees to date. These findings can help explore new food items and their effective diet combinations

Diversity and specificity of sap-feeding herbivores and their parasitoids on Australian fig trees

The ecology, diversity, and parasitoid complex of plant–sap feeding insects of the family Homotomidae (Hemiptera: Psylloidea) specialised on fig trees (Ficus) have so far received little research attention. They are ecologically important, however, as occasional outbreaks of the homotomid Mycopsylla fici may cause complete defoliation of its host plant, the Moreton Bay fig (Ficus macrophylla). Mycopsylla proxima, the only other species reported from Australia, feeds on F. rubiginosa without any recorded outbreaks. We searched for homotomids and their parasitoids on eight Ficus species on the east coast of Australia, Lord Howe Island (LHI), and in Auckland, New Zealand, and detected them on three Ficus species. Using mitochondrial and nuclear DNA sequences, we delimited three Mycopsylla species, including a putative new species on F. watkinsiana. We also characterised six (including one previously described) parasitoid species of the genus Psyllaephagus (Hymenoptera: Encyrtidae) based on congruent morphological characters and molecular data. Each of the homotomid species was highly host specific to a single fig species, whereas parasitoid species varied in host specificity: three host specific to M. fici and three host generalists. Geographic distribution varied among parasitoid species; e.g. one host-specific species was found on both the mainland and LHI, but a second species only on LHI. Our study revealed previously unrecognised diversity in fig homotomids and especially in their parasitoids. The herbivores and parasitoids showed contrasting patterns of host specificity. Interestingly, M. fici, the only outbreak species, had the highest diversity of associated parasitoid species and was the only species with host-specific parasitoids

The Role of Lipopolysaccharide and O-Antigen of Proteus Mirabilis in Urinary Stones Formation, In-Vitro Study

The ability to induce stone formation in-vitro of Proteus mirabilis isolates was investigated using whole bacterial cell, lipopolysaccharide, and O-antigen of these isolates. The results showed that all three parts have the ability to form crystallization in artificial urine solution, which based on the differences in urease activity and chemical structure of LPS and O-antigen. The whole bacterial cell of isolate No. 6 (P. mirabilis O18) revealed significant differences (P˂ 0.05) in the ability to bind with calcium (251.5 µg/ml) and magnesium (75.4 µg/ml) compared with the whole bacterial cell of isolate No. 14 (P. mirabilis O3) and isolate No. 3 (P. mirabilis O16), where the calcium concentrations were 238.77 µg/ml and 227.12 µg/ml, respectively; and magnesium concentrations were 53.34 µg/ml and 37.68 µg/ml for isolates No. 14 and 3, respectively. In contrast, LPS and O-antigen of isolates No. 14 and 3 showed significantly differences (P˂ 0.05) in the ability to metal binding with calcium (25.77 µg/ml and 25.06 µg/ml), respectively, and magnesium (6.6 µg/ml and 7.5 µg/ml), respectively, compared with LPS and O-antigen of isolate No. 6, where the calcium and magnesium concentration were 18.03 µg/ml and 3.16 µg/ml, respectively

Study of Some Virulence Factors of Proteus mirabilis Isolated from Urinary Stones Patients

A total of 125 specimens of stones and urine were collected from urinary stone patients from (June to December, 2012). According to primary identification, which based on macroscopic and microscopic characteristics and biochemical tests, 25 (20%) and 100 (80%) of isolates were identified as Proteus and non-Proteus, respectively. The 25 Proteus isolates were finally identified as Proteus mirabilis based on Vitek 2 system and polymerase chain reaction (PCR) technique by using target gene 16S rRNA. The multiple logistic regressions results showed that the age ˃ 40 years old was a risk factors that significantly associated with increased incidence of P. mirabilis in urinary stone patients, as P = 0.02, and Odd’s ratio (OR) was 4.889 (1.7-14.057), while in relation to gender, the analysis revealed that they were statistically non-significant as OR was 1.174 (0.488-2.822) as well as P=0.720. Some virulence factors of all isolates were investigated by Qualitative and Quantitative assay. Qualitative assay showed that all isolates (100%) were positive to urease, biofilm, Adhesion factors, and swarming activity. Whereas, 40% of isolates were positive to protease and ESBL, 96% and 76% of isolates were positive to agglutination and β-lactamase, respectively. Quantitative assay revealed that all tested isolates were significantly differences P˂ 0.05 in the production of the tested virulence factors. The urease production activity range from 59 to 129 U/ml, whereas the protease production activity ranged from 2.5 to 8 U/ml; the mean of adhering to uroepithelial cell ranged from (20-45) bacteria/cell. The mean of optical density ranged from (0.028-033) at OD630 and the percentages of biofilm activity were 60%, 24% and 16% as strong, moderate and weak biofilm, respectively. The mean of swarming growth activity of P. mirabilis isolates ranged from (3-67mm) and 40%, 32%, 8%, and 20% of isolates showed strong, moderate, weak, and very weak swarming activity, respectively.