Eli BenâSasson, Alessandro Chiesa, Michael A. Forbes, Ariel Gabizon · 6 authors
We present the first constructions of single-prover proof systems that achieve perfect zero knowledge (PZK) for languages beyond NP, under no intractability assumptions: 1. The complexity class #P has PZK proofs in the model of Interactive PCPs (IPCPs) [KR08], where the verifier first receives from the prover a PCP and then engages with the prover in an Interactive Proof (IP). 2. The complexity class NEXP has PZK proofs in the model of Interactive Oracle Proofs (IOPs) [BCS16,RRR16], where the verifier, in every round of interaction, receives a PCP from the prover. Our constructions rely on succinct simulators that enable us to "simulate beyond NP", achieving exponential savings in efficiency over [BCGV16]. These simulators crucially rely on solving a problem that lies at the intersection of coding theory, linear algebra, and computational complexity, which we call the succinct constraint detection problem, and consists of detecting dual constraints with polynomial support size for codes of exponential block length. Our two results rely on solutions to this problem for fundamental classes of linear codes: * An algorithm to detect constraints for Reed--Muller codes of exponential length. * An algorithm to detect constraints for PCPs of Proximity of Reed--Solomon codes [BS08] of exponential degree. The first algorithm exploits the Raz--Shpilka [RS05] deterministic polynomial identity testing algorithm, and shows, to our knowledge, a first connection of algebraic complexity theory with zero knowledge. Along the way, we give a perfect zero knowledge analogue of the celebrated sumcheck protocol [LFKN92], by leveraging both succinct constraint detection and low-degree testing. The second algorithm exploits the recursive structure of the PCPs of Proximity to show that small-support constraints are "locally" spanned by a small number of small-support constraints.
Juri Mattila, Timo SeppÀlÀ, Catarina Naucler, Riitta Stahl · 7 authors
To encourage public discourse on blockchain use case development, this paper provides a pragmatic view on how to develop and to describe blockchain use cases. We approach the issue by developing a tentative use case for autonomous machine-to-machine transactions of electricity in a housing society environment through an iterative process with stakeholders in the energy industry. We proceed by evaluating the outlined concept and its technical specifications against six criteria for a sensible blockchain use case, as identified by blockchain industry specialists. Finally, we conclude with observations and discussion on the use case development process, and its future steps.
The characteristics of a representative set of Health Sciences virtual libraries were analyzed with the further aim of identifying good practices that could be to put into practice in the Spanish context. Projects were selected in countries with a decentralized health management system similar the Spanish one. The following variables were analyzed: structure, financing, content, process coordination and interlibrary cooperation bodies. Also, good practices that can be applied to the Spanish national model were identified, of which we highlight the centralization of processes and the presence of organisms or interlibrary cooperation.
BACKGROUND: Universal Health Coverage (UHC) has emerged as a major goal for health care delivery in the post-2015 development agenda. It is viewed as a solution to health care needs in low and middle countries with growing enthusiasm at both national and global levels. Throughout the world, however, the paths of countries to UHC have differed. South Africa is currently reforming its health system with UHC through developing a national health insurance (NHI) program. This will be practically achieved through a decentralized approach, the district health system, the main vehicle for delivering services since democracy. METHODS: We utilize a review of relevant documents, conducted between September 2014 and December 2015 of district health systems (DHS) and UHC and their ideological underpinnings, to explore the opportunities and challenges, of the district health system in achieving UHC in South Africa. RESULTS: Review of data from the NHI pilot districts suggests that as South Africa embarks on reforms toward UHC, there is a need for a minimal universal coverage and emphasis on district particularity and positive discrimination so as to bridge health inequities. The disparities across districts in relation to health profiles/demographics, health delivery performance, management of health institutions or district management capacity, income levels/socio-economic status and social determinants of health, compliance with quality standards and above all the burden of disease can only be minimised through positive discrimination by paying more attention to underserved and disadavantaged communities. CONCLUSIONS: We conclude that in South Africa the DHS is pivotal to health reform and UHC may be best achieved through minimal universal coverage with positive discrimination to ensure disparities across districts in relation to disease burden, human resources, financing and investment, administration and management capacity, service readiness and availability and the health access inequalities are consciously implicated. Yet ideological and practical issues make its achievement problematic.
Hermann Elendner, Simon Trimborn, Bobby Ong, Teik Ming Lee
Crypto-currencies have developed a vibrant market since bitcoin, the first crypto-currency, was created in 2009. We look at the properties of cryptocurrencies as financial assets in a broad cross-section. We discuss approaches of altcoins to generate value and their trading and information platforms. Then we investigate crypto-currencies as alternative investment assets, studying their returns and the co-movements of altcoin prices with bitcoin and against each other. We evaluate their addition to investors' portfolios and document they are indeed able to enhance the diversification of portfolios due to their little co-movements with established assets, as well as with each other. Furthermore, we evaluate pure portfolios of crypto-currencies: an equallyweighted one, a value-weighted one, and one based on the CRypto-currency IndeX (CRIX). The CRIX portfolio displays lower risk than any individual of the liquid crypto-currencies. We also document the changing characteristics of the crypto-currency market. Deepening liquidity is accompanied by a rise in market value, and a growing number of altcoins is contributing larger amounts to aggregate crypto-currency market capitalization.
Cryptocurrencies are a type of digital currencies based on cryptography principles. Cryptocurrencies are a unique combination of three characteristics: they provide anonymity, they are independent of central authority and they provide protection from double spending attack. The aim of this paper is to capture trends in the area of significant cryptocurrencies price developments and to explain their causes. The current research in this area is exclusively limited to an analysis of the price developments of the most important Bitcoin cryptocurrency; our research is the first to focus on other cryptocurrencies too. The economic perspective on cryptocurrencies is based on IT knowledge regarding the principles of their functioning. We have created a database of prices of 1278 cryptocurrencies from 2013 to 2016. This database is publicly available. To analyse the data, SQL query language was used.
This study aims to analyze the relationship between fiscal decentralization, fiscal capacity, financial independence and financial expenditure areas in achieving social justice. In this case, the East Java Province Indonesia is supported by the existence of local government district / municipality became the main object of study during 2010 -2014. The needed data are such as; financial balance data, regional revenue, the amount of local spending and social justice data on people's lives. Data analysis method used is Partial Least Square (PLS). The results provide the conclusion that the implementation of the fiscal decentralization policy gives positive and significant impact on local fiscal capacity. Fiscal capacity gives positive and significant impact on the local financial independence. Local financial independence gives positive and significant impact on the structure of the shopping area. The structure of local government spending has a significant effect on the achievement of social justice areas. In this case, the fiscal capacity and financial independence have no direct impact significantly on the achievement of social justice in the various districts / cities in East Java. In addition, this study also provides important conclusion that there is a significant indirect effect of fiscal decentralization on social justice through local fiscal capacity, local financial independence and the structure of local government spending.
Blockchain is a decentralized transaction and data management technology developed first for Bitcoin cryptocurrency. The interest in Blockchain technology has been increasing since the idea was coined in 2008. The reason for the interest in Blockchain is its central attributes that provide security, anonymity and data integrity without any third party organization in control of the transactions, and therefore it creates interesting research areas, especially from the perspective of technical challenges and limitations. In this research, we have conducted a systematic mapping study with the goal of collecting all relevant research on Blockchain technology. Our objective is to understand the current research topics, challenges and future directions regarding Blockchain technology from the technical perspective. We have extracted 41 primary papers from scientific databases. The results show that focus in over 80% of the papers is on Bitcoin system and less than 20% deals with other Blockchain applications including e.g. smart contracts and licensing. The majority of research is focusing on revealing and improving limitations of Blockchain from privacy and security perspectives, but many of the proposed solutions lack concrete evaluation on their effectiveness. Many other Blockchain scalability related challenges including throughput and latency have been left unstudied. On the basis of this study, recommendations on future research directions are provided for researchers.
The scope of the system of the JST financial management is connected by these individuals with the multitude and the kind of running tasks on individual rungs of the local self-government (commune, district, province). The right realization of the JST share in public incomes appropriately for tasks falling to them is connected not only with a need to make the distribution of income public between the state and the local self-government and individual his rungs, but adaptations also amounts of obtained profits on assigned sources of tasks to essential expenses on the cost recovery performed. Similarly this principle must be taken into consideration at the forming of the JST liberty of the subject up to the general subsidy and specific subsidies from the state budget, of instruments of acts serving balancing budgets local and commissioned to the execution of tasks in the form, in it of defensive tasks. An entirety of planning, organizational and material-financial undertakings is resulting in defensive tasks of couples fulfilled by government administration authorities, of local self-government and other operators and state institutions, as well as entrepreneurs on which a statutory obligation of the defensive execution of tasks was imposed. Implementing the principle of the decentralization of the authority of the state in Poland the considerable part of duties of the state was handed over to authorities self-government and representing them for organs. From here they are also performing JST substantial role amongst entities performing defensive tasks, in frames non-military of system of the defensive state. Defensive JST tasks are being financed from many sources. And their financial needs, in this respect, result mainly from character and the scope of performed objectives.
<em>Since 2001</em><em> the</em><em> r</em><em>egional autonomy policies have </em><em>br</em><em>ou</em><em>g</em><em>ht</em><em> out</em><em> seven new provinces in Indonesia. Consequently, </em><em>they</em><em> require the central transfer budget to finance the delegated duties and authorities and the development programs in each province</em><em>.</em><em> Since its establishment until today, the fiscal capacity in seven provinces except Banten has not fulfilled the increase in local expenditure needs every year. It still much depends on the central transfer because the local revenue source like PAD is</em><em> very low</em><em>. This research uses a descriptive method-analysis by analyzing the secondary data relevant to the discussed topic and using the concept of fiscal capacity in the framework of the fiscal decentralization theory. The results of this qualitative research explain that the high fiscal capacity index (IKF) is obtained by </em><em>four </em><em>provinces those are Bangka Belitung, West Papua, Riau, and North Maluku, while the intermediate index is obtained by Banten, and the low fiscal capacity index is obtained by Gorontalo and West Sulawesi. Good fiscal capacity with high index does not guarantee that the poor population in the area will be reduced as West Papua and Riau which populations are still relatively large. Besides, Bantam with the very high PAD compared with six other provinces still has a large number of poor population of poor among seven provinces. But, overall the central transfer is recognized to be very helpful for the fiscal capacity of the seven new provinces above.</em><em></em>
BACKGROUND: Although the specialty of cardiothoracic surgery has been practiced in Nigeria for many years, open heart surgery (OHS) has only in the last decade become relatively more frequent, mainly through visiting foreign cardiac surgical teams. At this early phase of development it is faced with multiple challenges, especially financing and local skilled manpower for which solutions have to be identified in order to ensure sustainability and future growth. This study is aimed at highlighting these obstacles to growth of cardiothoracic surgery based on our own institutional experience at Lagos State University Teaching Hospital (LASUTH) and the current status of OHS activity in other cardiothoracic centers in Nigeria. METHODS: Prospectively acquired data from our center from March 2004 to December 2015 was reviewed. A telephone survey was also conducted with all other institutions in Nigeria performing cardiac surgery. RESULTS: During the study period 1,520 patients underwent various procedures with a mean age of 37±22.4 years and 813 (53.5%) were males. There were 450 major procedures (29.6%), 889 minor procedures (58.5%) and 181 endoscopic procedures (11.9%). The top ten clinical diagnoses were empyema thoracis (17.5%), malignant pleural effusion (14.7%), chest trauma (12%), hemodialysis access (6.1%), bradyarrhythmia (5.3%), aerodigestive foreign bodies (4.1%), vascular injury (3.9%), pericardial disease (3.8%), lung cancer (3.6%) and congenital heart disease (3.4%). The range of procedures was chest tube insertion (41.6%), endoscopy (11.9%), lung procedures (7%), arterio-venous fistula (6.1%), pacemaker implantation (5.3%), vascular repair (4.4%), OHS (3.4%), esophageal procedures (2.6%), chest wall surgery (2%), video assisted thoracic surgery (2%), closed heart surgery (1.6%), diaphragmatic procedures (1.6%) and thymectomy (1%). Survey of 15 centers in Nigeria with cardiac surgery activity showed a total of 496 OHS cases between 1974 and 2016, with 330 cases (66.5%) done between 2012 and 2016. CONCLUSIONS: Infections, malignancy and trauma currently account for the bulk of cardiothoracic surgery practice in Nigeria, with surgical activity showing a predominance of minor procedures and comparatively minimal OHS activities. Identified challenges to increasing cardiothoracic surgical activity were limitations in manpower development, infrastructure, laboratory support, local availability of consumables, cost of surgery, funding mechanisms for surgery, multiple models for development of cardiac surgery, decentralization of efforts and lack of outcome data. Data collection and reporting of results must be started to enable development of more evidence-based practice.
As an implementation of decentralized development, village financial management (VFM) is a financing model in a way to closer the needs of development at the village level. Theoretically, the successful objectives achievement of this authority delegation is if VFM can be done efficiently and effectively. This study aimed to analyze these efficiency and effectiveness of VFM and analyze factors inhibiting. The results showed that 1) VFM in Asahan district has not implemented both efficiently and effectively that shown from the weak implementation of both good governance principles and continuous improvement and, 2) Factors inhibiting the efficiency and effectiveness of VFM are, (i) lack of musrenbang transparency specifically the quality of information, access to information, the transparency mechanism of information and the level of information disclosure, (ii) lack of budgeting transparency, in particular the level of information disclosure, access to information and quality of information, (iii) lack of supervision transparency in particular the level of transparency, information quality and information access, (iv) the weak of oversight participation, especially the satisfaction level of participation and involve the community, and (v) lack of monitoring accountability in particular public complaints mechanism, access to the audit report and the responsibility structure.
The ability to predict financial markets has tremendous potential to limit exposure\nto risk and provide better assurances of annualized gains. In this thesis, a\nmodel for predicting the future daily price of Bitcoin is proposed and evaluated\nin comparison to that of a purely random model. Bitcoin is a novel digital currency\nthat relies on cryptography instead of a central authority to verify transactions.\nWithout a central authority, Bitcoin requires a complete list of all transactions\nto be made public so that they can be verified by all users. This unique\nfeature of Bitcoin, where all transactions are public, is exploited by the model\nto predict the future price directions based on the actions of Bitcoin users. The\ndaily activity of the markets, aggregate network features, and the actions of major\nnetwork influencers are all used as features for the predictive model. Where major\nnetwork influencers are defined as users that accumulate a disproportionate\namount of wealth within the Bitcoin network compared to others. The information\nabout the actions of all Bitcoin users are extracted from the blockchain and\nstored in a relational database for ease of use. Two metrics were created to identify\nthe major network influencers based on the history of their actions recorded\non the blockchain. The first metric, based on the concept of an h-index, often\nused in academia to rank authors by their citations, is used to rank users by the\namount of wealth they accumulate monthly. The second metric is based on the\noptimization of multiple objectives, the maximum increase in wealth with the\nleast amount of activity using Pareto optimization. All of the major network influencers\nidentified were then used as features, in combination with aggregate\nnetwork features, and market data, to test and evaluate several predictive models.\nThe models created were based on non-linear equations, support vector machines,\ndecision trees, and XGBoost; all evaluated and compared using the same\ndata. The XGBoost model consistently proved to be much more accurate than all\nother models and was used for the final set of experiments. The XGBoost model\nwas compared to that of a purely random Monte Carlo model using the entire\nhistory of data for the period of 2013???2016. The first set of experiments were conducted\nusing various sizes of training and testing data, in each case the XGBoost\nmodel had an accuracy 20% greater than that of the Monte Carlo model. For\nthe final experiments, the model was tested in a realistic scenario, predicting the\nprice direction for each future day, while also being re-trained using the results\nof each new day. The XGBoost model achieved a much better performance in\ncomparison to the Monte Carlo model, which had approximately 50% accuracy,\nwhereas the XGBoost model had 70%???79% accuracy.
Fear of a creeping Islamization of the âWestâ and its secular legal and constitutional orders has fueled debates on immigration in the media and politics for several years. With the ascent of the so-called âIslamic Stateâ and the horrific terror attacks it claimed or inspired, as well as the waves of refugees from Muslim-majority countries reaching European shores, debates have further intensified. They are turning increasingly populist, further feeding the flames of fear. In the United Kingdom, the successful but divisive campaign for the UK to leave the European Union is said to have strongly benefitted from voters hoping to stop Muslim (alongside East European) immigration. In the US, president-elect Donald Trump appealed to supporters during his campaign promising a complete ban on Muslimsâ entering the US, if elected president. In Germany, the far right and anti-Islam movement âPatriotic Europeans Against the Islamisation of the West,â abbreviated âPEGIDA,â has won many followers; the AfD, a folkish-populist right wing party has prospered on a divisive anti-immigration, anti-Islam platform and threatens the dominance of mainstream parties. A common claim is that Muslims in the West are building states within states, where parallel legal structures in the form of Shariâa councils are the first step to erode the statesâ secular constitutional order. The spread of extremist thought subversive to the state by homegrown Islamists further heightens the fear. Two recent books by Machteld Zee and John R. Bowen promise to take a closer look at Shariâa councils, their constitutional basis, practice and (in)compatibility with the constitutional order of Western states. Reviewing the books side by side, it becomes quickly clear that though they cover the same ground, and in fact, evaluate the very same institutions and their leaders, their assessment starkly diverges; itself a mirror of the prevailing polarization. The concurrent reading of both books also highlights the pitfalls of Zeeâs book, while cementing Bowenâs reputation as distinguished expert on Islam and anthropology. Unfortunately, Zeeâs book is beset with inaccuracies and errors, which are largely rebutted by Bowenâs book. Zee sets out asserting that âthe development of British Sharia councils is the result of the combination of multiculturalism and Islamic fundamentalism.â She passionately stresses the need to talk about Islamic fundamentalism, which âchallenges the relationship between religion and the state as we know it in the Westâ (Zee, at xi). Throughout the book, her main concern is womenâs rights, a legitimate concern generally, but particularly so when considering the undeniable inequality in treatment of men and women in many Muslim majority states. In contrast, framing the background and purpose of his book, Bowen highlights âa moral panic . . . over claims that state-aided schools in Birmingham were promoting shariâa and Islamic extremismâ and fears that âshariâa councils endanger[] the rule of law and gender equality throughout Britainâ (Bowen, at 3). In his words, Shariâa councils âhave become a flashpoint in British public debates, drawing the ire and fire of many commentators even as they adapt to the English legal environmentâ (at 4). In response, thereto, his book is intended as a âstudy of British Islam to âhighlights issues and practices surrounding shariâaâ (at 3). Accordingly, whilst Zee explicitly sets out her opinion on the desirability of Shariâa councils, Bowen frames his book as a descriptive and matter of fact analysis of the history and the current state of British Islam to unmask misconceptions. However, his work is not without bias either, and his underlying aim to calm the prevailing panic is apparent from the very start. Zeeâs book is divided into three distinct parts, in which she sets out to cover, first, a theoretical discussion of the multiculturalist ideology, second, a summary of Islamic fundamentalism, and, third, Shariâa councils as the practical consequence of the prevailing multiculturalist ideology in the West and the Islamic fundamentalism practiced in our midst. The three parts are disjointed, as she acknowledges. In Part I, reading akin to a Bachelor or Master thesis, Zee confronts the reader with two tribes in the imaginary country of âSea landistan,â expressing the hope âthat after at least 25 years of multiculturalist sensitivities a fresh case of cultural twists can open the mind for healthy judgmentâ (at 19). In Sealandistan, two vastly different groups live side by side. One group kill their eldest when they reach 90, but greatly value animal welfare; another group celebrates a monthly feast during which they enjoy kicking animals to death. She then uses this artificial scenario in an attempt to deconstruct six tenets which she alleges underlie the multicultural ideology: (i) who someone authentically is, is determined by his or her cultural identity; (ii) non-recognition of this cultural identity constitutes psychological harm; (iii) culture is good; (iv) cultures are equal; (v) cultural differences are good, but if not, they should at least be tolerated; and (vi) minority cultures must not be criticized by the dominant culture which has the positive obligation to preserve these. To support her claims, she references and quotes well-known authors relevant to the multicultural debate. At the same time, the chapter is interspersed with polemic and often irrelevant statements: âWe get told âif we were all the same the world would be a dull placeâ (imagine those poor monocultural African tribes not mixed with Asian homosexuals and Maori)â (at 34). Perhaps for reasons of brevity, or perhaps for reasons of her polemic style and lack of detachment, the author does not succeed in setting out how the claimed tenets are arrived at or how the theoretical analysis and the example of Sealandistan are relevant to the remaining parts of the book. This is unfortunate as she does mention several pitfalls of multiculturalism. In Part II she addresses Islamic fundamentalism, which is built on the premise that âthere is increasing competition between Islamic and secular law on Western soilâ (at 52). While Zee succeeds in highlighting some of the main features of Islamic fundamentalism, it becomes apparent that the authorâs knowledge of Islam, albeit not completely lacking, is limited. To illustrate, she equates Islamic fundamentalism âfor the purpose of clarity . . . with the concepts of Islamism and political Islam,â while incorrectly classifying in the same paragraph Egyptâs al-Azhar University as espousing the same (at 52). Likewise, it is disappointing that she quotes Ahadiths (Arabic, plural of Hadith, the transmitted word of the prophet) by questionable secondary literature. Zee translates the infamous daraba (beating) verse of the Quran twice in her book, but fails to comment on the difference in translation, or perhaps even fails to notice it: On page 63, she translates it as âmen have authority over women, for Allah has made the one superior to the other,â while quoting the same passage as âmen are the protectors and maintainers of women, because Allah has given the one more (strength) than the other . . .â twelve pages thereafter. Continuing her polemic style used in Part I, she introduces Saudi Arabia as âthe most âcompleteâ Sharia state, to see what happens if Islamist principles are the basis of a nationâs blueprint, starting with the judicial foundationâ (at 64). This is seemingly to indicate what awaits Europe if the spread of Shariâa councils is not halted. Subsequently she cites Malaysia as a nation that âintrinsically changed for the worstâ and âislamised in a short period of timeâ (at 73). In Part II, Zee entertains and supports the belief that the term âIslamophobiaâ was invented to âstifle debate and suppress criticism of Islamâ and that âthe term was created by Islamists to create an atmosphere of victimisation, where Muslims are continuously portrayed as victims suffering from hatred, discrimination and negative stereotypingâ (at 86). Sometimes the book has undertones of a conspiracy theory, such as when the author appears to espouse the belief that Yusuf al-Qaradawi, a well-known Islamic scholar, and Tareq Ramadan, Professor of Islamic Studies at Oxford University, together with Muslim and Islamist organizations are actively working towards establishing a global Shariâa state, whereby ghettoization and institutions such as Shariâa councils are only a pre-stage to the establishment of a worldwide Shariâa state. This is allegedly based on a pact between the Muslim Brotherhood and Wahhabi Saudi Islam, which together have succeeded in a short period to build media outlets, educational centers and, importantly Shariâa councils. That Wahhabi Saudi-Arabia has had a multifarious and regularly thorny relationship with the Muslim Brotherhood, particularly in the recent past, is nowhere considered.1 Finally, in Part III and, so to speak, the culmination of her groundwork of Part I on multiculturalism and Part II on fundamentalism, Zee takes a closer look at Shariâa councils in the UK. It is here that the qualitative difference between Zeeâs research and that of Bowen becomes most obvious. Both Zee and Bowen focus on the very same Shariâa Councils, namely the Islamic Sharia Council (ISC) in London, the Birmingham Central Mosque Sharia Council and the Muslim Arbitration Tribunal in Nuneaton. We will therefore look at Bowenâs book, with references to Zeeâs. Whereas Zee extensively quotes tabloids throughout her book, Bowen derides the same and turns the rectification of tabloid messages into the raison dâĂȘtre of his book. Bowenâs book is cohesive, and unmasks many of Zeeâs assertions as erroneous. In Part I, âPathways,â Bowen provides the reader with the origins of the establishment of Shariâa councils in the UK by looking at the historical background of British Muslims in East Asia, and the current topography, i.e., their geographical concentration in Britain and internal divisions (at 10â25). In contrast, Zee qualifies British Shariâa councils as the fruits of Saudi and Muslim Brotherhood efforts to Islamize the United Kingdom (at 116 et seq.) In Part II, âPractices,â Bowen presents his findings collected through interviews, attend ance at client sessions and Shariâa councils deliberations over a period from 2007 to 2013, as well as reviews of case files, wherever available. He deals with the same institutions as Zee does, who, however, only spent two afternoons at the ISC and half a day at the Birmingham Central Mosque Sharia Council (Zee, at 131). Bowen focuses on the legal issues and procedures in divorce cases mentioning only tangentially the general reputation of the councilsâ members, with judgment reserved to the readers. This is particularly interesting in relation to the ISC, where some of the council members are known in the press as extremists or Salafists. Zee, in contrast, draws on such characterizations to further her general message of the book, i.e., that Shariâa councils are bad for our constitutional order and must be feared. Bowenâs descriptive style stands in stark contrast to Zeeâs, who considers her three afternoons at Shariâa councils as sufficient evidence to draw sweeping conclusions such as that âall Sharia councils condone violence against womenâ (at 139). Perhaps owing to his descriptive style, Bowen consist ently remains neutral and detached, even when considering controversies surrounding Shariâa councils, for example that Islamic law, as commonly interpreted by Shariâa councils, continues to disadvantage women. The core of Bowenâs work is his detailed analysis of the constitutional challenges at stake in Shariâa councils, which he labels âunstable performativityâ (Bowen, at 88â102). Given that Shariâa councils do not have legal legitimacy in the United Kingdom, with no claims to valid legal authority and only a self-proclaimed religious authority (at 89), Bowen analyses what the act of marriage dissolution performed by the Shariâa council actually amounts to in legal and constitutional terms. He explains that institutions depend on the capacity to change the world by performative acts such as decreeing, stating, affirming, announcing, pronouncing. In the works of the Shariâa councils, Bowen identifies, first, judicial performativity, whereby a marriage is dissolved by the council itself, second, the husbandâs performativity, when he agrees to a divorce, even if reluctant and, third coupleâs performativity, when the council certifies the breakdown of the marriage that has already occurred, i.e., when the marriage is dissolved due to nonperformance by one of the parties. Bowen shows that the Shariâa councils rely on all three performativity theories, despite them being mutually exclusive. Accordingly, their performativity is âintrinsically unstableâ (at 90). In Part III, Bowen provides a detailed description of the work of the Birmingham Central Mosque Sharia Council as well as the Sufi Muslim Arbitration Tribunal in Nuneaton, both of which are also covered by Zee. Bowen focuses on the heart of the Shariâa council debate in the media, in particular the popular critique that such councils hollow out womenâs constitutional protection. He highlights that within their communities Shariâa councils provide a way for women to break free from an abusive relationship, in a manner acceptable to their community. They are seen as institutions that divorce women against their husbandsâ will. Thus, he suggests that they actually support womenâs rights. In contrast, Zee argues that the existence of Shariâa councils forces women to seek religious divorces keeping them trapped in failed marriages longer than they should and forcing them to negotiate away rights (such as custody), they might not even know they have. Bowen highlights however that religious divorce proceedings may often last no longer than civil divorces in the UK. In Part IV, âBoundaries,â Bowen acknowledges, albeit indirectly, that Shariâa councils are lacking in terms of equality. At the same time, however, he points out that their services are increasingly adapting to the British constitutional and other legal expectations (Bowem, at 210â28). Perhaps his overall assessment is too positive and apologetic. But only Bowenâs book provides the necessary insights that enable readers to get a better understanding of the complex issues at play. Zeeâs book merely polarizes. Reading their texts side by side offers several examples of the complexities involved, one of which shall suffice here for illustration purposes: Comparing Shariâa councils with their Jewish equivalent, the Batei Din, Zee mentions the fact that not many Shariâa councils have thus far applied for registration under the Divorces (Religious Marriages) Act 2002, as proof of their miso gynist leanings. Yet, Bowenâs more detailed discussion shows that the issue is a lot more complicated than that. The Divorces Act was passed with the aim of preventing limping marriages in the Jewish community, whereby a couple may have a civil divorce but the husband then subsequently declines to agree to a religious divorce. Under Jewish law, as commonly interpreted, a woman cannot divorce her husband against his will, nor can a court or Bet Din for that matter. Thus, to incentivize husbands to consent to a Jewish divorce, the Act allows the courts to halt a civil divorce, until a religious divorce is finalized. Hence, as Bowen highlights, registering under the Act might not actually benefit Muslim women. Were Shariâa councils to register under the Act, a husband would be able prolong the civil proceedings by using dilatory tactics in the religious proceedings. Since he may remarry under Shariâa, as commonly interpreted, while still being married, he would not have an interest in finalizing the divorce. Moreover, a Muslim woman may under Shariâa get divorced against the husbandâs will, in stark contrast to her Jewish counterpart. There is thus no upside for Shariâa Councils to register, other than making the divorce more difficult for the wife. Bowenâs book is not without fault. While his analysis is based on extensive empirical research on Shariâa councils, he does not sufficiently address the possibility that the sessions of the Shariâa councils he attends are affected by his presence. This is true even where, as in one reported session, one of the ISC members, Haitham al-Haddad, refuses to continue the discussion since it is being recorded by Bowen (at 105). (Haitham al-Haddad is one of the members profiled by the media and Zee as misogynist and extremist.) In line with his descriptive style, Bowenâs book ends without firm conclusions or strong answers, leaving many questions open. This is due to the complex nature of the issue at stake, but can also be a little dissatisfying to the reader. In stark contrast, Zeeâs book concludes with a brief plea for states to adopt âpolitical agnosticismâ as opposed to âmulticulturalismâ to stop the advance of Shariâa councils undermining Western democracies. (At no stage does she provide any meaningful analysis of political agnosticism.) Bowenâs book ultimately provides a very valuable resource for readers interested in the workings of Shariâa councils. The same cannot be said for Zeeâs book, whose academic quality is questionable, and a good read only for those interested in affirming opinions already swayed by the anti-Muslim zeitgeist.
I got to thinking the other day. Thinking what might have happened had hip arthroscopy never existed. Around the world I see colleagues being threatened by Governments, insurers, even departmental heads who should know better. The basic tenet of the threats is that impingement is unproven surgery and, as a consequence, should not be undertaken until proof exists. So, my first question is simpleâwhat do we (or they) mean by proof? Readers of JHPS may have read a recent Editorial,1 which addressed this very issue. There appears to be a view that only the procedure with the most successful result is the one that should be offered. Yet how valid a position is this? It must surely depend on the patient; patients, as many might agree, are at best unpredictable. For example, if one operation carries a 95% chance of success and another only 65%, does that mean the 65% procedure is contraindicated? Let us look more closely. First, our definition of success, and our derivation of 95%, may not be the same as a patientâs and second, by what right do we discount a lower score? Take osteoarthritis, or for that matter dysplasia, as examples. The party line is that hip arthroscopy should not be undertaken in the presence of osteoarthritis nor, for that matter, in dysplasia. I have seen blood almost spilt at meetings when this matter is debated. And yet there are numerous papers now published that declare symptoms can be improved in both these conditions by the use of hip arthroscopy. Looking closer still, we know that an arthroplasty undertaken for osteoarthritis of the hip has a probable 95% chance of improving a patientâs symptoms. We also know that a hip arthroscopy has, roughly, a 55% chance of doing the same, albeit for a limited time period. Does that mean hip arthroscopy should be excluded as a considered option? I think not but admit that is a purely personal view. I believe it is our responsibility as surgeons to lay out our stall and to discuss with our patients what is a suitable solution. One patient may select the 55% option, another the 95%. Ultimately it is a surgeon-advised, patient-decided conclusion that is reached. The patients are our masters and as few obstructions as possible should lie between patient and surgeon. Any non-medic who stands between these two key individuals should, in my view, hang their head in shame, assuming ethical practice, of course. So, I worry when I hear colleagues from around the world being asked to attend meetings with healthcare administrators, at times politicians, sometimes even each other, in order to justify the role of hip preservation surgery, arthroscopy in particular. As an observer it appears there is only one issue at stake, a desire by purse-string holders to save money. Surgeons have perhaps not helped themselves through the huge, 400% increase in the diagnosis and management of femoroacetabular impingement in the last ten years,2 a fact that led to the development of the so-called Warwick Agreement,3 remarkable not so much for its conclusions but that it brought together so many different interested parties from around the world. The challenge to hip preservation affects us all, but the patient in particular. It is our task as practitioners to protect our patients and to keep those whose sole mission is to save money from muddying the waters. I find it odd that the matter needs to be discussed at all when the UKâs National Institute for Health and Care Excellence (NICE) concluded 5 years ago that âCurrent evidence on the efficacy of arthroscopic femoroacetabular surgery for hip impingement syndrome is adequate in terms of symptom relief in the short and medium term.â4 Has so much changed? I doubt it. Other than the desire to save money, of course. To me the solution is very simple; let the patient decide. Turning to the last issue (number 3.3) of JHPS, this was again filled with more information than any editorial can reasonably summarize. The review by Bech et al.,5 I admit, went straight to our anaesthetic team, as reassurance that they are not alone in their management of pain after hip arthroscopic surgery. Meanwhile the paper by Hujazi et al.6 on the normal ischiofemoral distance definitely caught many eyes, as ischiofemoral impingement becomes more widely diagnosed in our various clinical practices. And as for this issue, number 3.4, where does an Editor-in-Chief begin? I am spoilt for choice. That said, I did especially like the paper by Kivlan et al.7 on defining the greater trochanter-ischial space. Impingement in that area was not a problem I had actually considered and kick myself for not doing so. Thanks to these three very capable authors for bringing the matter to our attention. And while discussing hitherto undescribed phenomena, how about the paper by Schröder et al.8 on their so-called âhip vacuum signâ, a new radiographic finding in FAI? I am straight back to all those frog-leg lateral radiographs to see what I might have missed. As with earlier issues, JHPS is once again filled to the hilt with pearls and I commend each and every one to you. My very best wishes to you all.
Peter Ittermann, Jonathan Niehaus, Hartmut HirschâKreinsen, Johannes Dregger · 5 authors
This paper is dealing with the ongoing debate of the digitization of german industry, the so-called âIndustrie 4.0â, and its social consequences. The discussed new technologies like cyber-physical production systems, autonomous logistic systems and smart devices are about to get integrated in work places, that are embedded in existing organizational and social structures, thus making âcomplementary innovationsâ and a coordinated design necessary. Our paper presents a human-centered design of industrial labor in a framework depicting the dilemma between what is techno-logically feasible and labor-politically desirable, under the constraint of an economically reasonable design of work and technology. The analytical approach is the âsocio-technical systemâ which as-sumes that there are certain varieties of organizational design at the interfaces of its sub-systems âtechnologyâ, âhumanâ and âorganizationâ. These considerations are transformed into a framework, called Social Manufacturing and Logistics, which brings together these perspectives and leads to a complementary holistic design of industrial labor under the conditions of a progressive digitization of manufacturing. Its characteristics are: hybrid interaction between human and machine, flexible integrated work and decentralized systems. Finally, we outline some organizational and social con-ditions to realize such a framework.
Emmanuelle Anceaume, Thibaut Lajoie-Mazenc, Romaric Ludinard, Bruno Sericola
Decentralized cryptocurrency systems offer a medium of exchange secured by cryptography, without the need of a centralized banking authority. Among others, Bitcoin is considered as the most mature one. Its popularity lies on the introduction of the concept of the blockchain, a public distributed ledger shared by all participants of the system. Double spending attacks and blockchain forks are two main issues in blockchain-based protocols. The first one refers to the ability of an adversary to use the very same bitcoin more than once, while blockchain forks cause transient inconsistencies in the blockchain. We show through probabilistic analysis that the reliability of recent solutions that exclusively rely on a particular type of Bitcoin actors, called miners, to guarantee the consistency of Bitcoin operations, drastically decreases with the size of the blockchain.
The value of bitcoin depends upon selfâfulfilling beliefs that are hard to pin down. We demonstrate this for the case where bitcoin is the only form of money in the economy and then generalize the message to the case of multiple bitcoin clones and/or a competing fiat currency. Some aspects of the indeterminacy we describe would no longer hold if bitcoin were an interestâbearing object. ( JEL D50, E42)
A trustless technology, Bitcoin tries to solve issues of social coordination and economic exchange by relying exclusively on technological means. Is technology alone able to resolve the social and political concerns affecting the Bitcoin network?
This paper uses a dynamic conditional correlation model to examine whether Bitcoin can act as a hedge and safe haven for major world stock indices, bonds, oil, gold, the general commodity index and the US dollar index. Daily and weekly data span from July 2011 to December 2015. Overall, the empirical results indicate that Bitcoin is a poor hedge and is suitable for diversification purposes only. However, Bitcoin can only serve as a strong safe haven against weekly extreme down movements in Asian stocks. We also show that Bitcoin hedging and safe haven properties vary between horizons.
Sep 29, 2016·In Proceedings of the 12th International Conference on Availability, Reliability and Security (ARES '17). ACM, New York, NY, USA, Article 43, 2017
Distributed Hash Tables (DHT) are a common architecture for decentralized applications and, therefore, would be suited for privacy-aware applications. However, currently existing DHTs allow every peer to access any index. To build privacy-aware applications, we need to control this access. In this paper, we present k-rAC, a privacy-aware fine-grained AC for DHTs. For authentication, we present three different mechanisms based on public-key cryptography, zero-knowledge-proofs, and cryptographic hashes. For authorization, we use distributed AC lists. The security of our approach is based on k-resilience. We show that our approach introduces an acceptable overhead and discuss its suitability for different scenarios.
OBJECTIVE:: To show that the administrative regime of specialized hospitals has some influence on the administrative processes to operate the Mexican Fund for Catastrophic Expenditures in Health (FPGC, in Spanish), for providing health care to breast cancer, cervical cancer and child leukemia. MATERIALS AND METHODS:: The variable for estimating administrative efficiency was the time estimated from case notification to reimbursement. For its estimation, semistructured interviews were applied to key actors involved in management of cancer care financed by FPGC. Additionally, a group of experts was organized to make recommendations for improving processes. RESULTS:: Specialized hospitals with a decentralized scheme showed less time to solve the administrative process in comparison with the model on the hospitals dependent on State Health Services, where timing and intermediation levels were higher. CONCLUSIONS:: Decentralized hospitals administrative scheme for specialized care is more efficient, because they tend to be more autonomous.
Bitcoin is a decentralised currency and payment system that seeks to eliminate the need for trusted authorities. It relies on a peer-to-peer network and cryptographic protocols to perform the functions of traditional financial intermediaries, such as verifying transactions and preserving the integrity of the system. This article examines the political economy of Bitcoin, in light of a recent dispute that divided the Bitcoin community with regard to a seemingly simple technical issue: whether or not to increase the block size of the Bitcoin blockchain. By looking at the socio-technical constructs of Bitcoin, the article distinguishes between two distinct coordination mechanisms: governance by the infrastructure (achieved via the Bitcoin protocol) and governance of the infrastructure (managed by the community of developers and other stakeholders). It then analyses the invisible politics inherent in these two mechanisms, which together display a highly technocratic power structure. On the one hand, as an attempt to be self-governing and self-sustaining, the Bitcoin network exhibits a strong market-driven approach to social trust and coordination, which has been embedded directly into the technical protocol. On the other hand, despite being an open source project, the development and maintenance of the Bitcoin code ultimately relies on a small core of highly skilled developers who play a key role in the design of the platform.