The increasing popularity of social networking is providing new opportunities for businesses in electronic commerce. It is evolving in order to adopt Web 2.0 capabilities to support online customer interactions and achieve greater economic value. This trend is referred to as social commerce. This study offers the result of a Systematic Literature Review (SLR) to explain the concept of social commerce. In order to elaborate this article, 64 papers were considered from the main digital libraries that index computer science conferences and journals. Applying a systematic analysis to these papers, it was possible to summarize the existing evidence concerning the social commerce and outline some open challenges.

The aim of this study was to evaluate the concentrations of Ca, P, S, Mg, K, and Na, and their distribution in major fractions of donkey milk (i.e., fat, casein, whey proteins, and aqueous phase). Individual milk samples were collected by mechanical milking from 16 clinically healthy lactating donkeys. Milk yield per milking was recorded and milk gross composition, casein content, and pH were determined. Whole milk samples were centrifuged to separate fat and to obtain skim milk. Skim milk samples were ultracentrifuged to separate a sedimentable casein pellet and to obtain a supernatant whey (soluble) fraction, which was then ultrafiltered to obtain the aqueous phase of donkey milk. Whole milk and the processed samples were analyzed for the aforementioned elements by inductively coupled plasma-mass spectrometry. The concentration of elements associated with fat, casein, and whey proteins was then calculated. All the Na was present in the aqueous phase. The fat fraction in donkey milk carried very little or none of the investigated elements. The majority of Ca (62.9%) and P (53.1%) was associated with casein, and the rest of these elements was mostly present in the aqueous phase. The majority of Mg was present in the aqueous phase, but a relevant part (32.6%) was associated with the casein fraction. No K was associated with casein. On a molar basis, the ratio of colloidal Ca and P to casein (mmol/g of casein) was more than double the values reported in literature for cow milk. The correlation coefficient was negative between milk pH and P in the ultracentrifuged (r = −0.81) and ultrafiltered (aqueous) fraction (r = −0.66). Milk pH correlated positively with colloidal Ca (r = 0.59) and with the ratio of colloidal Ca to casein (mmol/g of casein; r = 0.68). Colloidal Ca and P were positively correlated (r = 0.64). These data suggest that the high ratio of colloidal Ca and P to donkey casein micelles is due to a larger amount of colloidal calcium phosphate bound to casein micelles compared with literature data on cow milk. The percentage of elements associated with whey proteins was less than 5% for Ca, P, and K, but Mg reached approximately 9% of total Mg. The majority of S (63.6%) was associated with whey proteins, and only one-fourth of this element was associated with casein, indicating a higher content of sulfur-containing amino acids in donkey whey proteins than in casein.

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The aim of this study was to evaluate the concentrations of Zn,

Traditionally, computing infrastructure has been a substantial burden for companies. But what happens when business are unchained from their physical infrastructure and allowed to focus on business goal ? The model of infrastructure as a service and cloud computing bring us closer to this possibility. In this paper we discussed the growth of the web based service industry. The myriad of service now available over the internet rely on data center spread around the world. One of the major new trends in computing the rise of what is known as cloud computing, in witch not only service are offered remotely over the internet, but also a full menu of computing resource such a computing power, storage, databases, and many other resources. ©2010 IEEE