1,721,857 research outputs found
Convergence of platforms and strategies of two software vendors
Get PDFThesis (S.M.)--Massachusetts Institute of Technology, System Design and Management Program, 2008.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Includes bibliographical references (p. 145-157).Unified Communications: Convergence of Platforms and Strategies of Two Software Vendors by Muhammad Zia Hydari ABSTRACT Unified communication (UC) is the convergence of various modes of communication - voice telephony, email, instant messaging (IM), video conferencing and so on - used by enterprise workers. Academic literature exists that discusses digital convergence in various domains. Although UC has received considerable attention in the business press, we are not aware of any academic study within the domain of UC that explains the convergence of platforms and its links to the technology strategy of UC firms. This thesis presents an academic analysis of some platforms underlying UC and the emerging strategies of two software firms within the UC market. The theory of network effects originally developed by Rohlfs is central to the analysis in this thesis. The analysis of platform strategies of the UC firms is informed by the theoretical work on platform leadership (Gawer & Cusumano), convergence (Greenstein et al.), platform envelopment (Eisenmann et al.), and two-sided platforms (Tirole et al.). The thesis first describes four platform applications underlying UC viz. voice telephony, email, IM, and video communication. The analysis of email, IM and video communication in this thesis is unique as it takes a long term view to explain the current market situation within these domains. In particular, the thesis describes technological factors, network effects, standard battles, and competition that have led to the current market state. The thesis also links insights from these platforms to repercussions for UC supplier firms. The thesis then describes the strategies of two software vendors - Microsoft and IBM - using elements from Gawer & Cusumano's work on platform leadership.(cont.) Microsoft has defined a broad scope of innovation for its converged UC platform requiring it to enter the voice telephony market. The thesis posits that Microsoft's strategy for success is platform envelopment i.e. Microsoft is using shared components and installed user base from its email and IM platforms to create a multi-platform bundle and compete with entrenched platforms in the voice market. The thesis argues that IBM's choice for a narrower platform scope stems from its inferior market position in the email and IM markets as well as scope differences (vis-a-vis Microsoft). Convergence has created system integration opportunities that IBM's services unit has targeted. The thesis describes the implications of IBM's decisions on its ecosystem.by Muhammad Zia Hydari.S.M
Los cambios en las relaciones bilaterales políticas, económicas y militares de Pakistán con Estados Unidos en los últimos años de gobierno de Muhammad Zia Ul-Hag (1985-1988) y el gobierno de Benazir Bhutto (1988-1990)
Get PDFEsta monografia realiza una comparacion entre dos diferentes tipos de gobierno en Pakistan como fue el de Muhammad Zia Ul-Hag y el de Benzarir Bhutto; en cuanto a las relaciones bilaterales politicas, economicas y militares teniendo en cuenta que con el desarrollo de tecnologia nuclear en Pakistan esas relaciones se vieron afectadas.Comparison of two differents types of government in Pakistan as was that of Muhammad Zia Ul-Hag and the Benazir Buttho, in terms of bilateral relations political, economic, and military bearing in mind that the development of nuclear technology in Pakistan afected these relationships
Ipomea hederacea Jacq.: A Medicinal Herb with Promising Health Benefits
No full textIpomea hederacea Jacq. (kaladana or ivy leaf morning-glory), a member of the family Convolvulaceae, is used primarily for its seeds and recognized for its medicinal properties, especially in Asian countries. This medicinal herb contains various valuable chemical constituents such as ecdysteriods, steroidal glycosides, aromatic acids, triterpenes, amino acids, organic acids, mineral elements and vitamins. A number of pharmacological properties such as diuretic, anthelmintic, blood purifier, deobstruent, laxative, carminative and anti-inflammatory actions have been ascribed to this plant, besides its use to treat abdominal diseases, fevers, headache and bronchitis. This review focuses on compositional, medicinal and therapeutic properties of this plant, as a potential sources of bioactive molecules for medicinal and nutraceutical applications
Antioxidant Activity of the Extracts of Some Cowpea (Vigna unguiculata (L) Walp.) Cultivars Commonly Consumed in Pakistan
No full textThe present investigation has been carried out to determine the antioxidant activity of the methanolic extracts obtained from four cultivars of cowpea (Vigna unguiculata (L) Walp.) seeds. Phenolic compounds present in the extracts showed the antioxidant and antiradical properties when investigated using a linoleic acid peroxidation model, FRAP, ORAC and TRAP assays, as well as DPPH, hydroxyl, nitric oxide and superoxide radical scavenging activity. The HPLC analysis of the cowpea extracts showed the presence of neochlorogenic acid, chlorogenic acid and caffeic acids. The results indicated that methanolic extract of the cowpea resembled in the aforementioned activities those from other leguminous seeds and pulses. Phenolic constituents contained in cowpea may have a future role as ingredients in the development of functional foods
New 14-Membered Cyclopeptide Alkaloids from Zizyphus oxyphylla Edgew
No full textTwo new 14-membered cyclopeptide alkaloids, Oxyphylline B (4) and Oxyphylline C (5), along with three known 13-membered cyclopeptide alkaloids, were isolated from stem and roots of Zizyphus oxyphylla Edgew. The compounds were tested for antibacterial activity. Oxyphylline B (4) showed comparatively better antibacterial activities against Escherichia coli (MIC, 5 μg/mL) than other compounds. This compound also exhibited weak antimicrobial activities against Staphylococcus aureus (MIC, 25 μg/mL), Pseudomonas aeruginosa (MIC, 50 μg/mL) and Salmonella typhi (MIC, 50 μg/mL)
Phytochemical and Biological Studies of Agave attenuata
No full textThe present study was conducted to examine various biological activities of a methanol extract of Agave attenuata leaves. GC-MS analysis of the n-hexane fraction from the extract revealed the presence of 31 compounds, with mono-2-ethylhexyl phthalate (11.37%), 1,2-benzenedicarboxylic acid (6.33%), n-docosane (6.30%) and eicosane (6.02%) as the major components. The leaves contained appreciable levels of total phenolic contents (10.541–39.35 GAE, mg/100 g) and total flavonoid contents (43.35–304.8 CE, mg/100 g). The extract and some of its fractions showed moderate antimicrobial effects. Leaves extract and fractions also exhibited a good antioxidant potential when measured by DPPH radical scavenging activity and inhibition of lipid peroxidation assays. The hemolytic effect of the plant was found to be in a range of 1.01%–2.64%. From the present study it is concluded that this plant could be used as a source of natural antioxidants and functional food nutraceutical application
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Pharmacological Evaluation of Prosopis cineraria (L.) Druce in Gastrointestinal, Respiratory, and Vascular Disorders
Get PDFIn this paper, a crude methanolic extract from the stem bark of Prosopis cineraria, a plant native of Pakistan, was tested for its
possible presence of spasmolytic, bronchodilator, and vasodilator activities in an attempt to validate some of its folkloric uses.
Moreover, attempts weremade to provide plausible explanations of the observed biological activities. The extract caused relaxation
of the spontaneous as well as K+ (80mM)-induced contractions at tissue bath concentrations of 3–10 mg/mL in isolated rabbit
jejunumpreparations, probably mediated through blockade of Ca+2 channels. This finding was further confirmed by the shifting of the Ca+2 concentration response curves to the rightward in a manner similar to verapamil used as a standard Ca+2 channel blocker.
The extract also exhibited nonspecific relaxant effect on carbachol (1 μM)- and K+ (80 mM)-induced contractions in isolated rabbit tracheal preparations. The same effect was recorded for phenylephrine (11 μM) and K+ (80 mM)-induced contractions in isolated rabbit aortic preparations in a manner similar to verapamil. These observations confirmthat observed bronchodilator and vasodilator activities were possibly mediated through blockade of Ca+2 channels. The above-mentioned observations validate the traditional use of the plant in the treatment of respiratory and gastrointestinal ailments
Grewia asiatica L., a Food Plant with Multiple Uses
No full textGrewia asiatica L., is a species native to south Asia from Pakistan, east to Cambodia, cultivated primarily for its edible fruit and well-reputed for its diverse medicinal uses. Fruits are a rich source of nutrients such as proteins, amino acids, vitamins, and minerals and contain various bioactive compounds, like anthocyanins, tannins, phenolics and flavonoids. Different parts of this plant possess different pharmacological properties. Leaves have antimicrobial, anticancer, antiplatelet and antiemetic activities; fruit possess anticancer, antioxidant, radioprotective and antihyperglycemic properties; while stem bark possesses analgesic and anti-inflammatory activities. This review focuses on the botanical description, phytochemistry, nutritional studies and pharmacological properties of this plant
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