A CONSUMER-WELFARE APPROACH TO NETWORK NEUTRALITY REGULATION OF THE INTERNET

"Network neutrality" is the shorthand for a proposed regimeof economic regulation for the Internet. Because of the trendto deliver traditional telecommunications services, as wellas new forms of content and applications, by Internet protocol(IP), a regime of network neutrality regulation would displaceor subordinate a substantial portion of existing telecommunicationsregulation. If the United States adopts network neutrality regulation,other industrialized nations probably will soon follow. As aresult of their investment to create next-generation broadbandnetworks, network operators have the ability to innovate insidethe network by offering both senders and receivers of informationgreater bandwidth and prioritization of delivery. Network neutralityregulation would, among other things, prevent providers of broadbandInternet access service (such as digital subscriber line (DSL)or cable modem service) from offering a guaranteed, expediteddelivery speed in return for the payment of a fee. The practicaleffect of banning such differential pricing (called "accesstiering" by its critics) would be to prevent the pricing ofaccess to content or applications providers according to priorityof delivery. To the extent that an advertiser of a good or servicewould be willing to contract with a network operator for advertisingspace on the network operator's affiliated content, anotherpractical effect of network neutrality regulation would be toerect a barrier to vertical integration of network operatorsinto advertising-based business models that could supplementor replace revenues earned from their existing usage-based businessmodels. Moreover, by making end-users pay for the full costof broadband access, network neutrality regulation would denybroadband access to the large number of consumers who wouldnot be able to afford, or who would not have a willingness topay for, what would otherwise be less expensive access. Forexample, Google is planning to offer broadband access to end-usersfor free in San Francisco by charging other content providersfor advertising. This product offering is evidently predicatedon the belief that many end-users demand discounted or freebroadband access that is paid for by parties other than themselves.Proponents of network neutrality regulation argue that suchrestrictions on the pricing policies of network operators arenecessary to preserve innovation on the edges of the network,as opposed to innovation within the network. However, recognizingthat network congestion and real-time applications demand somedifferential pricing according to bandwidth or priority, proponentsof network neutrality regulation would allow broadband Internetaccess providers to charge higher prices to end-users (but notcontent or applications providers) who consume more bandwidthor who seek priority delivery of certain traffic. Thus, thedebate over network neutrality is essentially a debate overhow best to finance the construction and maintenance of a broadbandnetwork in a two-sided market in which senders and receivershave additive demand for the delivery of a given piece of information—andhence additive willingness to pay. Well-established tools ofRamsey pricing from regulatory economics can shed light on whethernetwork congestion and recovery of sunk investment in infrastructureare best addressed by charging providers of content and applications,broadband users, or both for expedited delivery. Apart fromthis pricing problem, an analytically simpler component of proposednetwork neutrality regulation would prohibit a network operatorfrom denying its users access to certain websites and Internetapplications, such as voice over Internet protocol (VoIP). Althoughsome instances of blocking of VoIP have been reported, suchconduct is not a serious risk to competition. To address thisconcern, I analyze whether market forces (that is, competitionamong access providers) and existing regulatory structures aresufficient to protect broadband users. I conclude that economicwelfare would be maximized by allowing access providers to differentiateservices vis-à-vis providers of content and applicationsin value-enhancing ways and by relying on existing legal regimesto protect consumers against the exercise of market power, shouldit exist.     

单个细胞DNA样本的制备及其在灵敏度分析中的应用研究

目的建立一种用于高精确灵敏度分析的微量DNA样本制备方法。方法用显微捕获技术制备以细胞为单位的DNA样本,并用于ProfilerPlus试剂盒及ABI310遗传分析仪的灵敏度测试。结果建立了单细胞捕获操作方案,成功制备了依次含1～11个细胞的一组DNA分析样本,并可准确用于ProfilerPlus誖试剂盒及ABI310遗传分析仪的灵敏度研究。结论基于显微操作技术的高精确微量DNA分析样本制备方法可准确用于分析技术方法的灵敏度研究     

苓桂术甘汤对免疫功能低下模型小鼠淋巴细胞活性的影响

目的:观察苓桂术甘汤对免疫功能低下模型小鼠免疫功能的影响.方法:近交系昆明种小鼠以环磷酰胺(Cy,80 mg/kg,ip,qd×1)诱导免疫功能低下,用苓桂术甘汤(42.90,21.45,4.29 g/kg)连续灌胃(ig)给药7 d,分别采用免疫溶血法、四氮唑盐比色法(MTT)和小鼠胸腺细胞氚标胸腺嘧啶核苷(3H-TdR)掺入法测定血清溶血素、NK细胞及IL-2活性.结果:苓桂术甘汤能明显促进Cy所致免疫功能低下模型小鼠血清溶血素生成,增强NK细胞及IL-2活性,与模型组比较,差异有显著性(P＜0.05或P＜0.01).结论:苓桂术甘汤对Cy所致免疫功能低下模型小鼠三类淋巴细胞的免疫活性均具有明显的激活作用.     

加味四逆散对皮质酮、谷氨酸致PC12细胞损伤的保护作用研究

目的:观察中药加味四逆散(Jiawei Sinisan,JWSNS)对皮质酮(corticOSterone,Cort)、谷氨酸(glutamate,Glu)致PC12细胞损伤的保护作用.方法:以100,200,400 μmol/L Cort和10,50,100 μmol/L Glu以及50,100 ml/L JWSNS含药血清分别与PC12细胞共同孵育24 h,采用倒置显微镜观察细胞形态,以甲基噻唑基四唑(methyl thiazolyl tetrazolium,MTT)法测定细胞存活率.选取200 μmol/L Cort和50 μmol/L Glu建立PC12细胞损伤模型,以MTT法观察50,100ml/L JWSNS含药血清各组对Cort和Glu所致PC12细胞损伤的保护作用.结果:不同浓度的Cort和Glu对PC12细胞的生长均具有抑制作用,随着浓度的升高,细胞损伤程度加重.各浓度的JWSNS含药血清对正常PC12细胞无毒性和不良反应.对Cort和Glu所致的PC12细胞模型,50ml/L JWSNS含药血清各组无明显抗损伤作用;Cort,Glu 100 ml/L JWSNS含药血清低、中、高各组细胞存活率分别为72.58%、87.11%、75.81%、69.35%、82.25%和70.97%,与Cort、Glu损伤模型组及正常血清组相比,细胞存活率明显升高,差异有显著性(P＜0.05,P＜0.01).结论:100ml/L JWSNS含药血清对Cort、Glu所致PC12细胞的损伤具有保护作用.     

校园手机短信文化的调查报告

通过对大学生手机消费情况、手机短信功能的调查与分析,阐述了手机短信文化的消极和积极作用.从中让我们发现,虽然短信文化是现代社会兴起的一种流行文化,但是如何规范手机短信也是当务之急.     

Analoge Anwendung des Befristungsabschlags auf alle Hauptmietzinsvereinbarungen nach § 16 Abs 1 MRG

§ 9 Abs 4 RBG 1987 l?sst (nur) die Vereinbarung eines angemessenen Hauptmietzinses, definiert durch dieselben Merkmale wie in § 16 Abs 1 MRG, zu. Die Mietzinsbildungsvorschrift des § 9 Abs 4 RBG ist trotz der nicht deutlichen Formulierung auch eine Mietzinsbeschr?nkungsvorschrift. Die erforderliche Gleichbehandlung aller ausdrücklich oder inhaltlich dem § 16 Abs 1 MRG zu unterstellenden Hauptmietzinsvereinbarungen gebietet, die in § 16 Abs 7 MRG normierte Reduktion des angemessenen Hauptmietzinses auch im Fall einer Vereinbarung nach § 9 Abs 4 RBG 1987 vorzunehmen.     

海南鳽胃肠道内分泌细胞的免疫组织化学定位及形态观察

运用组织学、免疫组织化学方法对海南的胃肠道内分泌细胞分布、内分泌细胞的免疫组织化学定位及形态特点进行了初步研究。发现海南的胃及小肠各段都有嗜银细胞,其中胃和前肠分布最多,中肠、后肠逐渐减少。银染细胞在胃组织中以圆形和不规则形的居多,在小肠段以长棒状、圆形的居多。应用生长抑素抗血清、胰高血糖素抗血清、胃泌素抗血清对海南胃肠道内分泌细胞进行免疫组织化学定位,发现生长抑素细胞在胃肠道均有分布,其中在腺胃和前肠最多,往后逐渐减少;在胃肠道均未发现胃泌素细胞和胰高血糖素细胞。