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

Rhodium-Catalyzed Endo -Selective Epoxide-Opening Cascades: Formal Synthesis of (−)-Brevisin

[Rh(CO)₂Cl]₂ is as an effective catalyst for endo-selective cyclizations and cascades of epoxy-(E)-enoate alcohols, thus enabling the synthesis of oxepanes and oxepane-containing polyethers from di- and trisubstituted epoxides. Syntheses of the ABC and EF ring systems of (−)-brevisin via all endo-diepoxide-opening cascades using this method constitute a formal total synthesis and demonstrate the utility of this methodology in the context of the synthesis of marine ladder polyether natural products.National Institute of General Medical Sciences (U.S.) (GM72566)National Institute of General Medical Sciences (U.S.) (F32GM095014

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

Mental imagery of whole-body motion along the sagittal-anteroposterior axis

Whole-body motor imagery is conceptualised as a mental symbolisation directly and indirectly associated with neural oscillations similar to whole-body motor execution. Motor and somatosensory activity, including vestibular activity, is a typical corticocortical substrate of body motion. Yet, it is not clear how this neural substrate is organised when participants are instructed to imagine moving their body forward or backward along the sagittal-anteroposterior axis. It is the aim of the current study to identify the fingerprint of the neural substrate by recording the cortical activity of 39 participants via a 32 electroencephalography (EEG) device. The participants were instructed to imagine moving their body forward or backward from a first-person perspective. Principal Component Analysis (i.e. PCA) applied to the neural activity of whole-body motor imagery revealed neural interconnections mirroring between forward and backward conditions: beta pre-motor and motor oscillations in the left and right hemisphere overshadowed beta parietal oscillations in forward condition, and beta parietal oscillations in the left and right hemisphere overshadowed beta pre-motor and motor oscillations in backward condition. Although functional significance needs to be discerned, beta pre-motor, motor and somatosensory oscillations might represent specific settings within the corticocortical network and provide meaningful information regarding the neural dynamics of continuous whole-body motion. It was concluded that the evoked multimodal fronto-parietal neural activity would correspond to the neural activity that could be expected if the participants were physically enacting movement of the whole-body in sagittal-anteroposterior plane as they would in their everyday environment

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

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

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