2,956 research outputs found

    Bioregion heterogeneity correlates with extensive mitochondrial DNA diversity in the Namaqua rock mouse, Micaelamys namaquensis (Rodentia: Muridae) from southern Africa - evidence for a species complex

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    <p>Abstract</p> <p>Background</p> <p>Intraspecific variation within the diverse southern African murine rodents has not been extensively investigated, yet cryptic diversity is evident in several taxa studied to date. The Namaqua rock mouse, <it>Micaelamys namaquensis </it>Smith, 1834 is a widespread endemic murine rodent from the subregion. Currently, a single species with four subspecies is recognised, but in the past up to 16 subspecies were described. Thus, this species is a good candidate for the investigation of patterns and processes of diversification in a diverse but under-studied mammalian subfamily and geographic region. Here, we report genetic differentiation based on mitochondrial DNA (mtDNA) cytochrome <it>b </it>(cyt <it>b</it>) sequences among samples collected over an extensive coverage of the species' range.</p> <p>Results</p> <p>Cytochrome <it>b </it>sequences of 360 widely sampled individuals identified 137 unique maternal alleles. Gene tree and phylogeographic analyses of these alleles suggest the presence of at least eight lineages or haplogroups (A-H), with varying degrees of intra-lineage diversity. This differentiation is in contrast with the most recent taxonomic treatment based on cranial morphometrics which only recognised four subspecies. The mtDNA diversity strongly supports earlier views that this taxon may represent a species complex. We further show statistical support for the association of several of these lineages with particular vegetation biomes of southern Africa. The time to the most recent common ancestor (TMRCA) dates to the Pliocene (~5 Mya) whereas coalescent-based divergence time estimates between lineages vary between 813 Kya [0.22 - 1.36] and 4.06 Mya [1.21 - 4.47]. The major diversification within lineages occurred during the Pleistocene. The identification of several regions of sympatry of distinct lineages offers future opportunities for the elucidation of the underlying speciation processes in the suggested species complex.</p> <p>Conclusions</p> <p>Similar to other African murine rodents, <it>M. namaquensis </it>radiated during the Pliocene and Pleistocene coinciding with major periods of aridification and the expansion of savanna habitats. The suggested species complex is represented by at least eight lineages of which the majority are confined to only one or a few neighbouring biomes/bioregions. Contrasting intra-lineage phylogeographic patterns suggest differences in adaptation and responses to Plio-Pleistocene climatic and vegetation changes. The role of ecological factors in driving speciation in the group needs further investigation.</p

    Sistem Pengisi dan Pengatur Tekanan Udara Ban Mobil secara Otomatis dengan Mikrokontroler

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    Sometimes to fill a tire with a air pump were made us tired. Not even to fill it up but we must check it up the tire pressure. The process of air pressure filling and control device for car tire automatically using microcontroller is the way of solution to every people to check up the tire easily. The systems can be measure maximum pressure until 50 psi then the system can be check for every change of voltage level to prove there is any leakage of tire. This system can help us more better to know our tire condition easily

    Design, Operation and Construction of a Large Rainfall Simulator for the Field Study on Acidic Barren Slope

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    The utilization of rainfall simulators has turned out to be more far reaching with the automated instrumentation and control systems. This paper portrays a rainfall simulator designed for analysis of erosion on steep (2.5H: 1V). A rainfall simulator designed to perform experiments in slope is introduced. The large scale of the apparatus allows the researcher to work in remote areas and on steep slopes. This simulator was designed to be effortlessly set up and kept up as well as able and additionally ready to create a variety of rainfall regimes. The nozzle performance tests and lateral spacing tests were performed at Research Center for Soft Soil (RECESS), which is another Research and Development (R and D) activity by Universiti Tun Hussein Onn Malaysia. This test system is the standard for research involving simulated rainfall. The rainfall simulator is a pressurized nozzle type simulator. It discharges uniform rainfall on a square plot 6 m wide by 6 m (19.685 ft) long. The fundamental parts of a sprinkler rainfall simulator are a nozzle, a structure in which installs the nozzle, and the connections with the water supply and the pumping system. The structure of the test system was manufactured created with four fixed hollow rectangular galvanised on which a header with 25 nozzles attached to it. The nozzles are spaced 1 m apart. Flow meters control the inflow of water from the storage tank, ensuring each nozzle has a similar release rate, regardless of the introduction of the test system. The tank that was utilized has the 200 gallons of water which is 757.08 Lit and the full with water in tank can run the artificial rainfall simulation roughly around 50 to 60 minutes. The support system is collapsible, easy to set up and maintain. The subsequent test system is conservative (under RM9,000 to build), made with industrially accessible parts, simple to set-up and maintain and highly accurate

    Kinetic and Thermodynamic Studies of Chromium Ion Adsorption Using Chitosan from Mussel Shell

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    A study was carried out to investigate the removal of chromium (VI) ion from chromate solution using deacetylated chitin extracted from mussel shell. Mussel shells were obtained from Gubi dam in Bauchi, Nigeria and chemical method was used to extract chitin and then chitosan from these shells. A batch adsorption study was used to generate data for kinetic modelling. Out of the four kinetic models tested, the adsorption process was found to follow the pseudo-second order kinetic model with an R2-value of 0.9997; The process was physical with a free sorption energy of 0.224 kJ/mol. Also, the enthalpy of adsorption was -67.295 kJ/mol K and the Gibbs free energies were all negative, thus the process is spontaeneous and exothermic. Keywords: Kinetic, Chitosan, Mussel, Chromium, Adsorption, Thermodynami

    The Flowering Habit of Nipa (Nypa fruticans Wurmb.) in Semi-wild Stands of the Davao Region, Philippines

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    Observations on the flowering characteristics of nipa (Nypa fruticans Wurmb.) were carried out on at least 70 randomly selected palms in various semi-wild stands found in the Davao Region, Philippines (i.e., Bago Aplaya, Ecoland, and Talomo) from April 2010 until February 2011. The developmental stages of inflorescence were identified, described in detail, and arbitrarily divided according to morphological changes exhibited by the inflorescence. These developmental stages are as follows: emergence (E) stage, stage 2 (S2), pre-anthesis (PA) stage, and the antheses stage, which is divided into the female receptivity (F) stage and the male anthesis (M) stage. Among the parameters measured for each stage include the length of the inflorescence from base to tip, the number and length of staminate rachillae, and the number of female flowers. For morphological characteristics comparison of this monoecious inflorescence, different stands in Carmen, Davao del Norte, were observed. The Carmen stands were significantly more fecund compared to the Davao City stands. The former had more female flower count (61 vs. 58 per pistillate head) and more staminate rachilla count (33 vs. 17 spikes) than the latter. The final inflorescence length in Carmen was significantly taller than in Davao City (117.5 cm vs. 84.3 cm), suggesting that the plants in the former had longer tapping potential for sap production. The results have implications toward the future program of nipa hybridization to produce better varieties

    Glass Rheology: From mode-coupling theory to a dynamical yield criterion

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    The mode coupling theory (MCT) of glasses, while offering an incomplete description of glass transition physics, represents the only established route to first-principles prediction of rheological behavior in nonergodic materials such as colloidal glasses. However, the constitutive equations derivable from MCT are somewhat intractable, hindering their practical use and also their interpretation. Here, we present a schematic (single-mode) MCT model which incorporates the tensorial structure of the full theory. Using it, we calculate the dynamic yield surface for a large class of flows

    Compositions Optimization of Antang Corundum for Developing Advanced Ceramic

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    The research aims to study and optimize the formulation of materials required for advanced ceramic production using response surface methodology (RSM). In this research effort, the five (5) process independent variables studied with their corresponding levels are: Antang corundum powder, A (92.2 – 100 %W); polyvinyl alcohol, B (0 – 5 %W); CaO, C (0 – 2.3 %W); MgO, D (0 – 0.5 %W); and the sintering temperature, E (1200 – 1500 °C). The mechanical property responses determined were density, ρ, compressive strength, C/S, flexural strength, F/S; which are key characteristics of ceramics for armour applications. The optimized density, compressive strength and flexural strength of the sintered Antang corundum are 3.45 g/cm3 g, 1982 MPa and 295 MPa respectively; while the respective RSM prediction values are 3.45 g/cm3 g, 1982 MPa and 295 MPa. On comparing the determined optimum mechanical responses of the sintered Antang ceramic with the maximum RSM prediction values, there is high level of assurance in using RSM for the formulation process in ceramic armour development

    PCS-17 The Potency Of Sernai Leaves (Wedelia biflora) to Increase Healing of contusion in Rats (Rattus norvegicus)

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    INTRODUCTION Contusion is a type of injury caused by a collision of the body with a blunt object followed by damage to the soft parts of the body, bone damage, bleeding and swelling. The tissue Injuries cause an inflammatory or inflammatory reaction, in which the inflammatory reaction is followed by pain (dolor), heat (kolor), red (rubor), swelling (tumor), and impaired function in the area around the wound (fungsiolesa). The Inflammatory reactions are the result of increased capillary permeability and migration of leukocytes to areas of inflamed tissue. The body's defense process against injury involves cells that infiltrate the wounded areas including neutrophils, macrophages, and lymphocytes. The body's response to inflammation is characterized by the release of neutrophils from the blood vessels which function as the first defense cells that play a role in phagocytosis of microorganisms and inflammatory cells in the wound. Contusion can be cured by giving anti-inflammatory drugs that aim to relieve pain, slow and prevent the spread of the tissue destruction process.the  Anti-inflammatory drugs are classified into two, namely Non-Steroid Anti-inflammatory (NSAIDs) and Anti-inflammatory Steroids (AIS), a class of anti-inflammatory drugs that have the ability to suppress signs and symptoms of inflammation. The use of anti-inflammatory drugs in humans can cause side effects that are harmful to the body such as ulcers, cardiovascular diseases and osteoporosis, while fot the animals cause the difficulties due to the large variety of species. Therefore, herbal ingredients are developed, one of which is sernai (Wedelia biflora). Sernai has empirical benefits as a medicine for wounds and ulcers , sernai leaf water extracts as antipyretics, antitripanosoma, antimicrobials, antifungal, and anti-inflammatory agents.Sernai contains alkaloids, terpenoids, triterpenoids and flavonoids. The Flavonoid compounds can inhibit the release of arachidonic acid, secretion of lysozyme enzymes from neutrophil cells and endothelial cells and inhibit the proliferation phase and exudation phase of the inflammatory process. If the prostaglandin pathway is inhibited, the the occurrence of local blood vessel vasodilatation will reduces and so a leukocyte infiltration decreases, then it is replaced by macrophages that function to help endothelial cell formation and new blood vessels so that wound healing can take place quickly

    Analisis Efektivitas Pemasangan Iklan Pada Aplikasi Mobile Dan Faktor-faktor Yang Memengaruhinya

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    Perkembangan sistem komunikasi yang semakin cepat membawa dampak yang cukup besar bagi dunia periklanan pada aplikasi mobile. Hal tersebut disebabkan oleh besarnya peluang bagi Perusahaan untuk memasarkan produknya dalam bentuk mobile advertisement. Mobile advertisement adalah sebuah iklan yang dapat tampil dalam berbagai bentuk, seperti musik, grafik, suara, atau tulisan melalui terminal telekomunikasi mobile. Salah satu kelebihan mobile advertisement adalah dapat melakukan one-to-one marketing dan mass marketing secara bersamaan. Pada umumnya Perusahaan menjalin kerjasama dengan pihak pengembang aplikasi mobile yang telah populer atau paling banyak diunduh, dengan cara memasang iklan pada aplikasi tersebut. Hingga saat ini masih belum diketahui secara jelas mengenai tingkat efektivitas teknik pemasaran produk atau jasa melalui pemasangan iklan pada aplikasi mobile. Efek pemasangan iklan pada aplikasi mobile kepada pengguna aplikasi belum menjadi hal yang dianggap penting oleh sebagian besar Perusahaan. Penelitian ini bertujuan untuk melakukan investigasi terhadap efektivitas iklan pada aplikasi mobile serta faktor-faktor yang memengaruhi sikap pengguna mobile terhadap iklan tersebut. Selain itu juga akan dihasilkan rekomendasi mengenai kriteria iklan yang baik. Penelitian ini akan dilakukan dengan menggunakan metode survey dan melihat korelasi antara beberapa parameter terkait periklanan pada aplikasi mobile. The development of increasingly rapid communications system brings a considerable impact to the world of advertising on mobile applications. This is due to the large opportunity for companies to market their products in the form of mobile advertisement. Mobile advertisement is an advertisement that can appear in various forms, such as music, graphics, sound, or text through a mobile telecommunication terminal. One of the advantages of mobile advertisement is able to perform one-to-one marketing and mass marketing simultaneously. In general, the company formed a partnership with the developers of mobile applications that have been popular or most downloaded, by placing ads on the application. Until now still not known clearly about the effectiveness of the marketing techniques of products or services through advertising on mobile applications. Effects of advertising on mobile applications to users of the application is not a thing that is considered important by most companies. This study aimed to investigate the effectiveness of advertising on mobile applications and the factors that influence user attitudes toward mobile advertising. They also produced recommendations on the criteria of a good ad. The research will be conducted using the survey method and see the correlation between several parameters related to advertising on mobile applications
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