2,241 research outputs found
Low latency via redundancy
Low latency is critical for interactive networked applications. But while we
know how to scale systems to increase capacity, reducing latency --- especially
the tail of the latency distribution --- can be much more difficult. In this
paper, we argue that the use of redundancy is an effective way to convert extra
capacity into reduced latency. By initiating redundant operations across
diverse resources and using the first result which completes, redundancy
improves a system's latency even under exceptional conditions. We study the
tradeoff with added system utilization, characterizing the situations in which
replicating all tasks reduces mean latency. We then demonstrate empirically
that replicating all operations can result in significant mean and tail latency
reduction in real-world systems including DNS queries, database servers, and
packet forwarding within networks
Comparing hospital and telephone follow-up after treatment for breast cancer: randomised equivalence trial
Objective To compare traditional hospital follow-up with telephone follow-up by specialist nurses after treatment for breast cancer.
Design A two centre randomised equivalence trial in which women remained in the study for a mean of 24 months.
Setting Outpatient clinics in two NHS hospital trusts in the north west of England
Participants 374 women treated for breast cancer who were at low to moderate risk of recurrence.
Interventions Participants were randomised to traditional hospital follow-up (consultation, clinical examination, and mammography as per hospital policy) or telephone follow-up by specialist nurses (consultation with structured intervention and mammography according to hospital policy).
Main outcome measures Psychological morbidity (state-trait anxiety inventory, general health questionnaire (GHQ-12)), participants’ needs for information, participants’ satisfaction, clinical investigations ordered, and time to detection of recurrent disease.
Results The 95% confidence interval for difference in mean state-trait scores adjusted for treatment received (−3.33 to 2.07) was within the predefined equivalence region (−3.5 to 3.5). The women in the telephone group were no more anxious as a result of foregoing clinic examinations and face-to-face consultations and reported higher levels of satisfaction than those attending hospital clinics (intention to treat P<0.001). The numbers of clinical investigations ordered did not differ between groups. Recurrences were few (4.5%), with no differences between groups for time to detection (median 60.5 (range 37-131) days in hospital group v 39.0 (10-152) days in telephone group; P=0.228).
Conclusions Telephone follow-up was well received by participants, with no physical or psychological disadvantage. It is suitable for women at low to moderate risk of recurrence and those with long travelling distances or mobility problems and decreases the burden on busy hospital clinics
Civil Forfeiture and the Eighth Amendment After \u3cem\u3eAustin\u3c/em\u3e
Imagine owning an expensive piece of property, a piece of real estate perhaps, or maybe a car or boat. Now imagine having your property forcefully taken away from you because someone suspects, or pretends to suspect, that you are using the property in the commission of criminal acts. Then, imagine having to hire a lawyer and start a lawsuit to recover your property. After spending a small fortune in legal fees to recover your own property, imagine you lose your lawsuit, not because you could not prove your rightful ownership before its forceful seizure, but because you could not prove that the person who seized the property lacked a reasonable suspicion that you were using the property in the commission of criminal acts or that you were not in fact using the property in the commission of criminal acts. Finally, imagine that your only recourse is buying your property back from the person who took it. Not likely to happen in America? Think again. It might not be likely to happen in America if a private party forcefully seized your property. But if your own government took it, you are in deep trouble. This is, in fact, what is happening all over America thanks to 21 U.S.C. § 881 (Section 881), the civil forfeiture statute, and other state and federal forfeiture provision
Civil Forfeiture and the Eighth Amendment After \u3cem\u3eAustin\u3c/em\u3e
Imagine owning an expensive piece of property, a piece of real estate perhaps, or maybe a car or boat. Now imagine having your property forcefully taken away from you because someone suspects, or pretends to suspect, that you are using the property in the commission of criminal acts. Then, imagine having to hire a lawyer and start a lawsuit to recover your property. After spending a small fortune in legal fees to recover your own property, imagine you lose your lawsuit, not because you could not prove your rightful ownership before its forceful seizure, but because you could not prove that the person who seized the property lacked a reasonable suspicion that you were using the property in the commission of criminal acts or that you were not in fact using the property in the commission of criminal acts. Finally, imagine that your only recourse is buying your property back from the person who took it. Not likely to happen in America? Think again. It might not be likely to happen in America if a private party forcefully seized your property. But if your own government took it, you are in deep trouble. This is, in fact, what is happening all over America thanks to 21 U.S.C. § 881 (Section 881), the civil forfeiture statute, and other state and federal forfeiture provision
Towards Communication-Efficient Quantum Oblivious Key Distribution
Oblivious Transfer, a fundamental problem in the field of secure multi-party
computation is defined as follows: A database DB of N bits held by Bob is
queried by a user Alice who is interested in the bit DB_b in such a way that
(1) Alice learns DB_b and only DB_b and (2) Bob does not learn anything about
Alice's choice b. While solutions to this problem in the classical domain rely
largely on unproven computational complexity theoretic assumptions, it is also
known that perfect solutions that guarantee both database and user privacy are
impossible in the quantum domain. Jakobi et al. [Phys. Rev. A, 83(2), 022301,
Feb 2011] proposed a protocol for Oblivious Transfer using well known QKD
techniques to establish an Oblivious Key to solve this problem. Their solution
provided a good degree of database and user privacy (using physical principles
like impossibility of perfectly distinguishing non-orthogonal quantum states
and the impossibility of superluminal communication) while being loss-resistant
and implementable with commercial QKD devices (due to the use of SARG04).
However, their Quantum Oblivious Key Distribution (QOKD) protocol requires a
communication complexity of O(N log N). Since modern databases can be extremely
large, it is important to reduce this communication as much as possible. In
this paper, we first suggest a modification of their protocol wherein the
number of qubits that need to be exchanged is reduced to O(N). A subsequent
generalization reduces the quantum communication complexity even further in
such a way that only a few hundred qubits are needed to be transferred even for
very large databases.Comment: 7 page
Stereoelectronic Model To Explain Highly Stereoselective Reactions of Seven-Membered-Ring Oxocarbenium-Ion Intermediates
Nucleophilic attack on seven-membered-ring oxocarbenium ions is generally highly stereoselective. The preferred mode of nucleophilic attack forms the product in a conformation that minimizes transannular interactions, thus leading to different stereoselectivity as compared to that of reactions involving six-membered-ring oxocarbenium ions
Recommended from our members
A systematic review of the effects of early separation on dairy cow and calf health
There is a growing concern from the public regarding early cow-calf separation, yet proponents of this practice maintain that artificial rearing is critical for cow and calf health. Early separation is assumed to reduce the risk of transfer of pathogens from dam to neonatal calf, but a wide range of health benefits associated with extended cow-calf contact has also been documented. The aim of this systematic review was to report and synthesize conclusions from the literature on dairy cow and calf health in conventional rearing versus cow-calf contact systems. Peer-reviewed, published manuscripts, written in English, directly comparing dairy cow or calf health in artificial versus suckling systems, were eligible for inclusion. We conducted 7-targeted searches using Web of Science (WoS) to identify key literature on important health conditions. The resulting manuscripts underwent a 4-step appraisal process, and further manuscripts were sourced from reference lists. This process resulted in a final sample of 70 articles that addressed cow and calf health. Sufficient literature was available to assess mastitis in cows, and scours, Cryptosporidiosis, Johne’s disease, pneumonia, immunity, and mortality in calves. The results for Cryptosporidiosis, pneumonia, immunity, and mortality were mixed, with some differences between studies likely attributable to flawed comparisons between cohorts. Overall, the articles addressing calf scours and mastitis pointed to beneficial or no effects of suckling. The studies addressing Johne’s disease did not find cow-calf contact to be a significant risk factor. In conclusion, the scientific peer-reviewed literature on cow and calf health provides no consistent evidence in support of early separation
Proposing a Pedigree Risk Measurement Strategy: Capturing the Intergenerational Transmission of Antisocial Behavior in a Nationally Representative Sample of Adults
An impressive literature has revealed that variation in virtually every measurable phenotype is the result of a combination of genetic and environmental influences. Based on these findings, studies that fail to use genetically informed modeling strategies risk model misspecification and biased parameter estimates. Twin- and adoption-based research designs have frequently been used to overcome this limitation. Despite the many advantages of such approaches, many available datasets do not contain samples of twins, siblings or adoptees, making it impossible to utilize these modeling strategies. The current study proposes a measurement strategy for estimating the intergenerational transmission of antisocial behavior (ASB) within a nationally representative sample of singletons using an extended pedigree risk approach that relies on information from first- and second-degree relatives. An evaluation of this approach revealed a pattern of findings that directly aligned with studies examining ASB using more traditional twin- and adoption-based research designs. While the proposed pedigree risk approach is not capable of effectively isolating genetic and environmental influences, this overall alignment in results provides tentative evidence suggesting that the proposed pedigree risk measure effectively captures genetic influences. Future replication studies are necessary as this observation remains preliminary. Whenever possible, more traditional quantitative genetic methodologies should be favored, but the presented strategy remains a viable alternative for more limited samples
The influence of emotional reaction on help seeking by victims of school bullying
Research has started to focus on how victims of school bullying cope, but there is still very little understanding if why pupils cope in one way and not another. This paper aimed to examine the effects of gender, school-stage, frequency of victimization and different emotions (anger, vengeance, self-pity, indifference, and helplessness) upon the choice of social support that children report using. Questionnaires were completed by 6282 Maltese schoolchildren aged between 9 and 14 years old. Analyses revealed that specific patterns of emotion and victimization predict whether pupils report using certain sources of social support. Results are discussed in relation to their relevance for possible intervention, future research needs and implications for the theoretical framework used
Relationship among research collaboration, number of documents and number of citations. A case study in Spanish computer science production in 2000-2009.
This paper analyzes the relationship among research collaboration, number of documents and number of citations of computer science research activity. It analyzes the number of documents and citations and how they vary by number of authors. They are also analyzed (according to author set cardinality) under different circumstances, that is, when documents are written in different types of collaboration, when documents are published in different document types, when documents are published in different computer science subdisciplines, and, finally, when documents are published by journals with different impact factor quartiles. To investigate the above relationships, this paper analyzes the publications listed in the Web of Science and produced by active Spanish university professors between 2000 and 2009, working in the computer science field. Analyzing all documents, we show that the highest percentage of documents are published by three authors, whereas single-authored documents account for the lowest percentage. By number of citations, there is no positive association between the author cardinality and citation impact. Statistical tests show that documents written by two authors receive more citations per document and year than documents published by more authors. In contrast, results do not show statistically significant differences between documents published by two authors and one author. The research findings suggest that international collaboration results on average in publications with higher citation rates than national and institutional collaborations. We also find differences regarding citation rates between journals and conferences, across different computer science subdisciplines and journal quartiles as expected. Finally, our impression is that the collaborative level (number of authors per document) will increase in the coming years, and documents published by three or four authors will be the trend in computer science literature
- …