Second-hand Information Research Articles

Communicating on Twitter during a disaster: An analysis of tweets during Typhoon Haiyan in the Philippines

Social media in crisis situations, such as natural disasters, have been recognized by scholars and practitioners as key communication channels that can complement traditional channels. However, there is limited empirical examination from the user perspective of the functions that social media play and the factors that explain such uses. In this study we examine Twitter use during and after Typhoon Haiyan pummeled the Philippines. We tested a typology of Twitter use based on previous research, and explored external factors – time of use and geographic location – and internal factors – type of stakeholders (e.g. ordinary citizens, journalists, etc.) and social media engagement – to predict these uses. The results showed that different stakeholders used social media mostly for dissemination of second-hand information, in coordinating relief efforts, and in memorializing those affected. Recommendations for future research and applications in future crises are also presented.

Meta-analysis and systematic review of the number of non-syndromic congenitally missing permanent teeth per affected individual and its influencing factors.

Dental aplasia (or hypodontia) is a frequent and challenging anomaly and thus of interest to many dental fields. Although the number of missing teeth (NMT) in each person is a major clinical determinant of treatment need, there is no meta-analysis on this subject. Therefore, we aimed to investigate the relevant literature, including epidemiological studies and research on dental/orthodontic patients. Among 50 reports, the effects of ethnicities, regions, sample sizes/types, subjects' minimum ages, journals' scientific credit, publication year, and gender composition of samples on the number of missing permanent teeth (except the third molars) per person were statistically analysed (α = 0.05, 0.025, 0.01). The inclusion of small studies and second-hand information might reduce the reliability. Nevertheless, these strategies increased the meta-sample size and favoured the generalisability. Moreover, data weighting was carried out to account for the effect of study sizes/precisions. The NMT per affected person was 1.675 [95% confidence interval (CI) = 1.621-1.728], 1.987 (95% CI = 1.949-2.024), and 1.893 (95% CI = 1.864-1.923), in randomly selected subjects, dental/orthodontic patients, and both groups combined, respectively. The effects of ethnicities (P > 0.9), continents (P > 0.3), and time (adjusting for the population type, P = 0.7) were not significant. Dental/orthodontic patients exhibited a significantly greater NMT compared to randomly selected subjects (P < 0.012). Larger samples (P = 0.000) and enrolling younger individuals (P = 0.000) might inflate the observed NMT per person. Time, ethnic backgrounds, and continents seem unlikely influencing factors. Subjects younger than 13 years should be excluded. Larger samples should be investigated by more observers.

Security Enhancements for Mobile Ad Hoc Networks With Trust Management Using Uncertain Reasoning

The distinctive features of mobile ad hoc net- works (MANETs), including dynamic topology and open wireless medium, may lead to MANETs suffering from many security vul- nerabilities. In this paper, using recent advances in uncertain rea- soning that originated from the artificial intelligence community, we propose a unified trust management scheme that enhances the security in MANETs. In the proposed trust management scheme, the trust model has two components: trust from direct observa- tion and trust from indirect observation. With direct observation from an observer node, the trust value is derived using Bayesian inference, which is a type of uncertain reasoning when the full probability model can be defined. On the other hand, with indirect observation, which is also called secondhand information that is obtained from neighbor nodes of the observer node, the trust value is derived using the Dempster-Shafer theory (DST), which is another type of uncertain reasoning when the proposition of interest can be derived by an indirect method. By combining these two components in the trust model, we can obtain more accurate trust values of the observed nodes in MANETs. We then evaluate our scheme under the scenario of MANET routing. Extensive simulation results show the effectiveness of the proposed scheme. Specifically, throughput and packet delivery ratio (PDR) can be improved significantly with slightly increased average end-to-end delay and overhead of messages.

Comment on “Communicating earthquake risk to the public: the trial of the ‘L’Aquila Seven’” by David E. Alexander

In his paper on the so-called L’Aquila trial, David Alexander (2014) states that “much of the international reaction to the trial was misguided because it was based on incomplete, second-hand information about the proceedings.” To support this hypothesis, his reasoning process refers back to the entire National Service of Civil Protection of Italy and, in particular, to the Italian Department of Civil Protection. As civil servants of this Department who are well aware of the circumstances treated, we would like to comment some of the Alexander’s statements, which present a partial, if not totally incorrect, representation of events. This comment, however, is not aimed at providing alternative and exhaustive representations or interpretations of the events, but rather at allowing the reader to form his own opinion with a more comprehensive description of the circumstances treated by Alexander.

PDMP report justifies further inquiry

Many states now have prescription drug monitoring programs (PDMPs) that assist in the screening of controlled substance prescriptions. The programs aggregate dispensing data uploaded by pharmacies and use the resulting database in responding to queries from health professionals who request a patient's medication history. The programs provide reports listing the controlled substance medications a patient has previously received. The basic idea is to prevent doctor shopping, in which one prescriber or pharmacist is unaware of medications provided to a patient by another prescriber or pharmacist. A recent case from Florida supports the idea that a PDMP report is a starting point, rather than an ending point, in the assessment of a patient's need for medication.

What do local fishermen from the mid Solimões river think about the giant river otter?

The giant river otter is a mustelid that uses different habitats in tropical forests and flooded areas of South America. In the past the species suffered heavy hunting pressure, due to the commercial value of its pelt, and nowadays is considered threatened by anthropogenic factors, such as negative interaction with fishing activities. The objective of this work was to analyze the perception of local fishermen in the town of Tefé, Amazonas (Brazil), generating information on possible threats to the species in the area. Fishermen point to the species as a competitor for food and responsible for damages to fishing gear, which causes a negative perception among humans towards the animal. An investigation of this relationship was conducted in Tefé, mid-Solimões river, where one-hundred fishermen were interviewed. Thirty-one percent (n = 31) of the interviewees declared giant river otters damage fishing nets and cause fish schools to flee. Among those who witnessed or had second-hand information on behaviors characteristic of the species, 22% (n = 22) interpreted them as offspring or territorial defense, or an attempt at attack. In the past, 23% (n = 23) of the interviewees practiced hunting activities, aiming the pelt trade and, secondarily, as an item of house decoration, or basic material to build a musical instrument. Information generated may contribute to the elaboration of an environmental education policy, aiming at avoiding future impacts to the giant otters due to lack of information, or misinformation by the local human population.

Market reaction to second-hand news: inside the attention-grabbing hypothesis

This article investigates whether the market reaction to second-hand information is due to price pressure or information dissemination. We use the perspective of attention grabbing to analyse the market reaction to the dissemination of analysts’ recommendations published in print media. This perspective is able to explain the asymmetric market reaction to ‘buy’ and ‘sell’ advice, which is difficult to rationalize within the price pressure hypothesis. We base our empirical analysis on the content of a weekly column in the most important Italian financial newspaper, which publishes past information and analysts’ recommendations on listed companies. Our findings show asymmetric price and volume reactions on the publication day. Contrary to previous evidence, we document a positive relationship between the number of analysts quoted in the column and the price (volume) increase associated with positive recommendations. Because the weekly columns seem to simply attract investors’ attention, with no additional new information, observing a reaction positively related to the column’s salience (proxied by the number of quoted analysts) is natural. In addition, we find that the market reaction is higher when the order size is lower, i.e., when individual investors’ trades constitute a higher fraction of the total trading activity in the market.

Communicating earthquake risk to the public: the trial of the “L’Aquila Seven”

The trial and conviction of seven public officials in L’Aquila, central Italy, for having allegedly given out misleading and incorrect information to the public before the 6 April 2009 earthquake has proved to be one of the most momentous developments of recent times in science and disaster risk reduction—and also one of the most misunderstood. It highlights the difficulty in transforming the findings of the earth sciences, which are often characterised by uncertainty, into information that can be used to protect ordinary citizens. This paper describes those elements of the disaster at L’Aquila which are pertinent to the trial and the legal proceedings that followed them. It analyses the political, social and scientific context of the trial, and the reaction of scientists and their institutions in Italy and other countries. I conclude that the defendants were tried as responsible public officials, not as scientists. The mass media in Italy and abroad tended to insist that what was on trial was the ability to predict earthquakes, and this had an enormous influence on the opinion of scientists in many different places. However, the trial was actually about the apparently fatal consequences of misleading the public with “incomplete, imprecise and contradictory information”, as the prosecutors put it. I believe that much of the international reaction to the trial was misguided because it was based on incomplete, second-hand information about the proceedings. If scientists were to make judgements on their own work in such a superficial manner, the results would be highly unreliable and public faith in science would plummet.

Not so harmless anymore: How context impacts the perception and electrocortical processing of neutral faces

Our first impression of others is highly influenced by their facial appearance. However, the perception and evaluation of faces is not only guided by internal features such as facial expressions, but also highly dependent on contextual information such as secondhand information (verbal descriptions) about the target person. To investigate the time course of contextual influences on cortical face processing, event-related brain potentials were investigated in response to neutral faces, which were preceded by brief verbal descriptions containing cues of affective valence (negative, neutral, positive) and self-reference (self-related vs. other-related). ERP analysis demonstrated that early and late stages of face processing are enhanced by negative and positive as well as self-relevant descriptions, although faces per se did not differ perceptually. Affective ratings of the faces confirmed these findings. Altogether, these results demonstrate for the first time both on an electrocortical and behavioral level how contextual information modifies early visual perception in a top-down manner.

A Hybrid Trust Management Framework for Wireless Sensor and Actuator Networks in Cyber-Physical Systems

To secure a wireless sensor and actuator network (WSAN) in cyber-physical systems, trust management framework copes with misbehavior problem of nodes and stimulate nodes to cooperate with each other. The existing trust management frameworks can be classified into reputation-based framework and trust establishment framework. There, however, are still many problems with these existing trust management frameworks, which remain unsolved, such as frangibility under possible attacks. To design a robust trust management framework, we identify the attacks to the existing frameworks, present the countermeasures to them, and propose a hybrid trust management framework (HTMF) to construct trust environment for WSANs in the paper. HTMF includes second-hand information and confidence value into trustworthiness evaluation and integrates the countermeasures into the trust formation. We preform extensive performance evaluations, which show that the proposed HTMF is more robust and reliable than the existing frameworks.

Effects of supply chain position on the motivation and practices of firms going green

Purpose – The aim of this study is to understand the effect of a firm's position in a supply chain in its industry on the attitude of the firm toward green strategies through empirical data analysis. This study aims to answer the following research questions: Do the environmental uncertainties a firm faces differ with the firm's position in the supply chain when going green?, Would the motivation of a firm for going green vary with uncertainties it faces in the supply chain? and Would green-related practices a firm accepts or executes vary with the firm's position in the supply chain? Design/methodology/approach – The case study method was utilized in this study. The main objects are firms in the high-tech industry of Taiwan, and 12 firms were selected for in-depth investigation. The unit of analysis was a firm. Face-to-face in-depth interviews, approximately 90-105 minutes for each, were conducted with each of the 12 cases. The respondents were middle- to high-level managers. The interviews were recorded and transcribed. Additionally, second-hand information was acquired regarding each case through channels such as firm web sites, documents, and media reports. These integrated data were later utilized in the single-case and cross-case analysis stages. Findings – In this study, firms of Taiwan's high-tech industry are divided into the upstream (raw material supplier), midstream (original design manufacturers/original equipment manufacturer), and downstream (brand company) categories. It is first found the uncertainties a firm encounters when implementing green practices are related to its position in the supply chain. The closer a firm is to the upstream of the supply chain, the higher the competitive uncertainty. In contrast, the closer a firm is to the downstream, the higher the demand uncertainty. Furthermore, the internal and external driving forces of firms in promoting green practices are related to the types of uncertainties the firms encounter in the supply chain. A firm's internal driving force is positively associated with the demand uncertainty it faces, however, negatively with the competition and supply uncertainties. On the other hand, a firm's external driving force is positively associated with the competition and supply uncertainties it faces, however, negatively with the demand uncertainties. Additionally, the association between firm willingness to promote green practices and its position in the supply chain is explored. It is found that, for firms located in the downstream of supply chain, it emphasizes more on the practices of green design, purchase, and internal environmental management. If a firm is located in the midstream of supply chain, it will focus more on the practice of green manufacturing and logistics. Originality/value – This study has expanded the discussion of green supply chain management. It establishes the relationship between the uncertainties and the major driving forces of firms for implementing green practices. This approach is rare in previous literature. Furthermore, past literature has suggested that a specific relationship exists between driving factors and firm practices. The author believes that such a relationship must be based on the position of firms in the supply chain; thus, the author has identified the relationship between supply chain position and green practices.

The Market and Temple Fairs of Rural China: Red Fire by Gene Cooper (review)

GENE COOPER, The Market and Temple Fairs of Rural China: Red Fire. London and New York: Routledge, 2013. xviii, 248 pp. US$155/£90 (hb). ISBN 978-0415 -52079-9 As mentioned in the preface, this is the second book on the Jinhua 金華 region, Zhejiang 浙江 province, published by Gene Cooper, professor of anthropology at the University of Southern California. His previous book was written jointly with Professor Jiang Yinhuo 蔣銀火 of the Department of Economics at Zhejiang University 浙江大學, focusing on the artisans and entrepreneurs of Dongyang 東 陽 County. During their travel throughout the region in the late 1980s in preparation for that book, the revival of local annual and semi-annual exchange fairs stimulated Cooper’s curiosity. Since such fairs were usually held on the ‘‘birthday’’ of a deity and centered on a local temple in earlier times, he considers them temple fairs in general even though today some of them are no longer connected with any temple. In 1998 Cooper returned to the region with the intent of carrying out multi-sited fieldwork on this topic. From July to December he visited eight towns in five counties. This enabled him to gain a closer view of such fairs as well as to collect much secondhand information, some of it only available locally. Part I of the book, following the ‘‘Introduction’’ in chapter 1, contains three chapters. Chapter 2 presents the geographic, historical, and political-economic background of the Jinhua region, centering on the city of Hengdian 橫店, a major movie-production center called ‘‘China’s Hollywood,’’ and the city of Yiwu 義烏, known for its internationally renowned small commodities market. These two cities display the strong economic dynamics of the region in recent decades. Traditional Buddhism and Daoism, including local deities, especially Huang Daxian 黄大仙, are presented in chapter 3. As perspectives for understanding modern Chinese religion, Cooper applies five ‘‘paradigms’’ proposed by Vincent Goossaert: orthodox/heterodox, religion/ superstition, elite/popular, institutional/diffused, and doctrinally pure/syncretic. He also adapts the notion of ‘‘diffused religion’’ used by C. K. Yang to interpret Chinese popular religious practice. Following Adam Y. Chau, who advanced a ‘‘sociothermic’’ theory of Chinese sociality, based on the Chinese notion of honghuo 紅火 [red fire, red hot], Cooper uses this term as the subtitle of the book and as a symbol for the carnivalesque social condition prevailing during temple fairs. A brief history of temple fairs in China and modern folkloristic studies of them are the subject of chapter 4. With regard to contents, the author relies heavily on secondary literature published by Chinese and Western scholars, among them Gao Youpeng 高有鵬, Lü Wei 呂微, Liu Xicheng 劉錫誠, Zhao Shiyu 趙世瑜, Laurence A. Schneider, etc. The framework of part II is inspired by Marcel Mauss’ concept of the ‘‘total social phenomenon,’’ which Cooper uses in chapters 5–10 to describe the commercial/economic, popular cultural, religious, and political dimensions of secular and temple fairs. He mostly gives a generalized overview and touches only slightly on different localities and cultural domains. As compensation for this approach, he discusses three specific case studies in detail, namely the Wuju 婺劇 opera, the resacralization of a fair in Fotang town 佛堂鎮, and the temple fair of 150 BOOK REVIEWS Hugong Dadi 胡公大帝. While the first two cases constitute separate chapters (7 and 10), the latter one is embedded in chapter 8 on ‘‘the religious dimension.’’ From my point of view as an ethnographer, these case studies are the highlights of the book. The vast amount of data on local cultural knowledge presented therein is well summarized from Chinese sources and is certainly useful as general information and as guidelines for future research. The discovery of the resacralization process reveals an important aspect of modern Chinese religious life. Possibly because of the dominance of Communist ideology in contemporary China, the revival of public religious practices such as temple fairs and sacrificial rituals often begins under the cover of diverse secular events serving cultural, commercial, or touristic ambitions of local governments. In some cases people attempt to establish an authentic atmosphere by adding or tolerating religious symbols and activities. In a concluding chapter Cooper repeats his obligation to the Maussian concept for his regional study; however, this does not reach beyond the simple fact that...

Re-evaluation of the evidence for the importation of red foxes from Europe to colonial America: Origins of the southeastern red fox (Vulpes vulpes fulva)

It is widely accepted that the red fox subspecies of southeastern North America (Vulpes vulpes fulva) is descended from red foxes imported from Europe to the American colonies for sport hunting. Thus, V. v. fulva is considered an exotic invasive organism that has apparently expanded its range to occupy much of the contiguous United States, with exception of the range of relict native populations in the western mountains and Sacramento Valley. I examined the evidence for importations and found that all claims of introduction stemmed to just two literature sources that were based on vague second-hand information. Together with results of morphological and genetic studies, this information indicates that V. v. fulva is native to North America. Thus, historical shifts in distribution and abundance of V. v. fulva and current management approaches should be re-evaluated in light of native status. Evaluating original sources of information can curtail the proliferation of inaccurate information and conclusions that influence conservation decisions.

Editorial Commentary: Telephone Consultation for Staphylococcus aureus Bacteremia: Opening Pandora's Box

An unsolicited call from a physician seeking advice about the management of a complicated condition such as Staphylococcus aureus bacteremia (SAB) is sometimes analogous to opening Pandora’s box. As soon as the conversation begins, troubles related to incorrect information, misstated facts and other misunderstandings figuratively “fly out.” Too often such discussions include preliminary, second-hand, incomplete or incorrect information. Surprisingly, the impact of telephone consultations on patient outcomes has received little scientific scrutiny. The study by Forsblom et al in this issue of Clinical Infectious Diseases is an important attempt to remedy this gap [1]. Forsblom et al retrospectively compared the relative effectiveness of bedside consultation with informal (mostly telephone) consultation for patients with SAB. Bedside infectious disease (ID) consultation was associated with more radiologic imaging, more frequent identification of focal infections, and longer hospitalization. However, bedside ID consultation had a crucially important benefit: it was associated with a lower 90-day mortality than telephone consultation. A sufficient duration of antibiotic therapy was given to 85% of patients who received a bedside consultation, compared with 63% of patients who were managed with telephone consultation (P = .008) in this study. Similar results were described in another study by Lahey et al [2]. In contrast, Fowler et al found that duration of antibiotic use was not significantly different in patients treated with or without formal ID consultation [3]. However, all physicians caring for patients with SAB received initial management recommendations by telephone and were given the option of formal bedside consultation. Only patients for whom recommendations were followed had significantly fewer relapses (6.3% vs 18.2%; P < .01) and a nonsignificantly lower rate of death [3]. These findings lead us to 2 general conclusions: first, assigning the proper duration of antibiotics is necessary but not sufficient to produce better outcomes in SAB; and second, clinicians do not always follow advice that is given by telephone or even by bedside consultation. Antibiotic selection is also a problem when patients with SAB are managed by means of telephone consultation in locations where methicillin-resistance and reduced susceptibility to vancomycin are prevalent among S. aureus isolates. For example, Kaye et al found that a majority of patients with SAB cared for in community hospitals in the southeastern United States did not receive an appropriate effective antibiotic as initial therapy [4]. As all ID specialists well know, antibiotic choice and duration are only part of the solution when treating SAB. Identification and eradication of primary or metastatic foci of SAB are essential components of the proper management of SAB. Failure to detect complications such as endocarditis, abscesses, or osteomyelitis has a deleterious impact on the chance of relapse and survival in patients with SAB [2, 3]. Identification of these complications requires knowing what to ask (the patient), where to look (physical examination), and how to find or prove the existence of these focal or metastatic infections. ID specialists who are asked to provide telephone consultations must rely on another clinician’s primary observations. If the physician asking for telephone advice does not provide accurate or thorough information, important diagnoses such as vertebral osteomyelitis can be missed. Indeed, Forsblom et al found that metastatic complications and focal infections were detected in a significantly higher percentage of patients with SAB who had bedside consultation, an observation that was also seen in the study by Lahey et al [2]. Varying amounts of relevant clinical information necessary for the proper Received 21 September 2012; accepted 24 July 2012. Correspondence: Dr. Vivian H. Chu, MD, Duke University Medical Center, Box 102359, Durham, NC (vivian.chu@duke. edu). Clinical Infectious Diseases © The Author 2012. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals. permissions@oup.com. DOI: 10.1093/cid/cis895

UK parents’ decision-making about measles–mumps–rubella (MMR) vaccine 10 years after the MMR-autism controversy: A qualitative analysis

Public concern about an unsubstantiated link between MMR vaccine and autism stemmed from a 1998 paper by Dr Andrew Wakefield and colleagues, and the substantial media coverage which that work attracted. Though the Wakefield paper is now discredited and an MMR-autism link has never been demonstrated empirically, this concern has manifested in over a decade of suboptimal MMR uptake. Few qualitative studies have explored parents' MMR decision-making since uptake began to improve in 2004. This study updates and adds methodological rigour to the evidence base. 24 mothers planning to accept, postpone or decline the first MMR dose (MMR1) for their 11-36 month-old children, described their decision-making in semi-structured interviews. Mothers were recruited via General Practice, parents' groups/online forums, and chain referral. MMR1 status was obtained from General Practice records 6 months post-interview. Interview transcripts were coded and interpreted using a modified Grounded Theory approach. Five themes were identified: MMR vaccine and controversy; Social and personal consequences of MMR decision; Health professionals and policy; Severity and prevalence of measles, mumps and rubella infections; Information about MMR and alternatives. Results indicated that MMR1 acceptors were sympathetic toward Wakefield as a person, but universally rejected his study which sparked the controversy; parents opting for single vaccines expressed the sense that immune overload is not a consideration but that not all three components of MMR are warranted by disease severity; and MMR1 rejectors openly criticised other parents' MMR decisions and decision-making. This study corroborated some previous qualitative work but indicated that the shrinking group of parents now rejecting MMR comprises mainly those with more extreme and complex anti-immunisation views, whilst parents opting for single vaccines may use second-hand information about the controversy. In response, policymakers and practitioners should revise their expectations of today's MMR decision-makers, and their methods for supporting them.

Psychotherapy in a Changing World

Psychotherapy in a Changing World

A study on small investors’ behavior in choosing stock case study: Kuala-Lumpur stock market

This study follows a qualitative methodology to investigate small investors’ behavior in choosing stock in Kuala-Lumpur stock market. Small investors usually capture the numerous factors to purchase a definite share within the security market. These factors dramatically influences investors’ behavior and change their decisions to purchase a particular stock. According to this description, the main purpose of this study is to identify the key determinants of choosing stock by small investors. A purposive sampling technique is employed to recruit 12 small investors based on desired range of demographic characteristics (for example sex and age), experience levels in purchasing stock and value of purchasing per time in ringgit. The research evidence reveals 13 effective factors in choosing stock which can influence small investors’ decisions for stock selection. These factors are in order of importance involving “financial statements of companies, accounting instruments, past stock price (return), firms’ public information, profitability variables, consult with anybody, financial ratios, past trading volume of stocks, second-hand information resources, discounted cash-flow tools, government policies, calculation of risk and economic variable. Key words: Small investors, investors’ behavior, institutional investors, individual investors, stock market.

Revisiting the theory of territory of information: How first-year university Chinese students handled first-hand and second-hand information

This article presents an investigation into the theory of territory of information in Chinese. As early as 1994, Kamio proposed a pragmatic theory of territory of information. Kamio claims that the theory is valid not only for Japanese but also for English (1995). The locus of this theory is the notion of territory, which is familiar from studies of animal behavior. In the present study, a questionnaire was used to inquire into subjects’ understanding of first-hand and second-hand information. In addition, twelve Written Discourse Completion Tasks (WDCTs), which represent a method for inter-language pragmatic assessment in the area of language testing, were used ( Brown, 2001; Liu, 2006). The subjects in this study were sixty first-year students who were pursuing two different non-English majors at a university in Mainland China. The data show that, although the notion of territory in terms of first-hand and second-hand information was acquired by the students to a certain extent, some of the forms they used in handling these two types of information are distinct from those used in English as Kamio specifies. The present study posits that the theory of territory of information is valid in Chinese; however, some modifications must be made to Kamio's formulation of the theory regarding the patterns of occurrence of psychological utterances and the conditions for assessing the directness of information.

Parameter-estimation based trust model for unstructured peer-to-peer networks

Reputation-based trust management mechanism has been identified as a viable solution to the security problems of peer-to-peer (P2P) networks in the last few years. The authors’ goal is to find a better model for good peers to withstand malicious activity of single malevolent peers and their collusions as well. In this article, the authors propose a novel trust model, based on parameter-estimation techniques named P-Trust to cope with misbehaviour in unstructured P2P networks. In this model each peer maintains direct trust information of others. The reputation system makes one peer evaluate other peers by the self-experiential and second-hand information. Meanwhile, incentive and punishment mechanism is taken to motivate peers to provide true information. The authors test and analyse the performance of a P-Trust against misbehaviour and the implementation costs. As a result, the authors’ model shows more effectiveness and robustness than the previous model.

Meta-analyses: first-rank evidence or second-hand information?

On the basis of a meta-analysis of randomized studies assessing reductions in 24 h ambulatory blood pressure, investigators have concluded that hydrochlorothiazide is an inappropriate first-line drug for antihypertensive treatment. This conclusion has the potential to change current prescribing practice for patients with hypertension, but should meta-analyses be considered the ultimate level of evidence, particularly those based on a surrogate outcome?