Non-trivial Cost Research Articles

Adaptive Task-Based Intermittent Computing System With Parallel State Backup

Energy harvesting promises to power billions of Internet-of-Things devices without being restricted by battery life. Since the energy harvester generally outputs weak and unstable energy, the system may suffer frequent and unpredictable power failures, thus falling into cyclically reboots without forward progress. Task-based intermittent computing system which periodically backs up system states into Non-Volatile Memory (NVM) is proposed to solve the non-progress problem, with the non-trivial cost of frequent backups. How to reduce the backup overhead becomes a major research problem for intermittent computing. Our paper, for the first time, proposes to parallelize state backup and program execution with asynchronous Direct Memory Access (DMA) to hide the backup latency into the program’s execution. But, straightforwardly executing the state backup and the program in parallel may cause inconsistent system state. In specific, the system state may be modified by the program during backup, and therefore may be backed up incorrectly and further cause the system to deliver an incorrect computation result. We make deep analysis on the system behavior and observe that, although the system state may be backed up incorrectly, the incorrect backup will be covered by the subsequent correct backups soon as the backup operations are performed frequently. In addition, only a small part of variables among all the program states may cause incorrect computation result. So, in this paper, we aggressively allow incorrect backups to occur, and propose a backup error detection method and a fault-tolerant backup management to guarantee the correctness of the system’s execution. To augment the parallel backup method, an adaptive execution method is further proposed to reduce the number of backups and balance the ratio between task execution time and backup latency. We design a run-time system to implement the proposed approach, and experimental results conducted on an STM32F7-based platform show that the proposed method can achieve a 2.6× average speedup.

215b. Real-World Experience of Letermovir Use at an Academic Transplant Center

Abstract Background Letermovir (LMV) is indicated for cytomegalovirus (CMV) prophylaxis in seropositive adults after allogeneic hematopoietic stem cell transplants (alloSCT). LMV is well tolerated compared to its alternatives. Our institution restricts LMV use to high-risk patient groups to maximize the cost/benefit of LMV. Despite these restrictions, LMV was in our institution’s top 50 drug expenditures, prompting a formal evaluation of its use. We describe a real-world experience with LMV at a 576-bed academic transplant center. Methods This was a single center, retrospective, descriptive study of LMV use at a transplant center. Any hospitalized patient who received ≥ 1 dose of LMV between August 2021 and January 2022 was eligible for analysis. Data collection included age, LMV administration data, length of stay, transplant status, Infectious Diseases (ID) consultation, documented rationale for non-criteria uses, and drug cost. The primary outcome was incidence of use not aligning with restriction criteria. The secondary outcome was institutional drug expenditure for non-criteria uses compared to approved uses. Results Over 6 months, 388 doses of LMV were administered to 31 unique patients during 41 admissions. LMV use during 12/41 admissions (31.7%) fell outside the institutional criteria. ID consult occurred in 58.3% (7/12) of cases. 27/31 (87%) were alloSCT patients, including 1 pediatric patient. There was also 1 liver and 1 heart transplant recipient. Reasons for non-criteria use were: primary prophylaxis in the heart transplant patient to avoid ganciclovir toxicity and in 2 alloSCT patients without high risk for CMV, pre-emptive therapy due to CMV reactivation (n=2), and step-down therapy for CMV viremia (n=4). LMV was used for extended periods ( > 100 days from transplant) in 2 cases. Non-criteria use of LMV accounted for $20 414 in drug cost over 6 months, 29% of total expenditure. Conclusion Our data suggest real world use of LMV often differs from the patient types enrolled in the phase 3 trials. Use of LMV as an alternative to available CMV therapies to avoid drug toxicities appears to drive much of this use. In addition, use outside of criteria was frequent and incurred a nontrivial cost. Modification of our criteria, such as requiring an ID consultation for off-label use, should be considered. Disclosures James S. Lewis, PharmD, FIDSA, Cidara: Advisor/Consultant|Merck: Advisor/Consultant|SeLux Diagnostics: Advisor/Consultant.

E‐commerce supply chains with considerations of cyber‐security: Should governments play a role?

E‐commerce supply chains and their members face risks from cyber‐attacks. Consumers who purchase goods online also risk having their private information stolen. Thus, businesses are investing to improve cyber‐security at a nontrivial cost. In this paper, we conduct a Stackelberg game‐theoretical analysis. In the basic model, we first derive the equilibrium pricing and cyber‐security level decisions in the e‐commerce supply chain. Based on real‐world practices, we then explore whether governments should impose cyber‐security penalty schemes. Our findings show that when the government is characterized by having sufficiently high emphasis on consumer surplus, implementing the penalty scheme is beneficial to social welfare. Then, we extend the analysis to examine how adopting systems security enhancing technologies (such as blockchain) will affect the government's choice of imposing penalty. We uncover that when it is beneficial to have government's penalty scheme, the technology benefit‐to‐cost ratio is a critical factor that governs whether the optimal penalty will be lower or higher with the adoption of systems security enhancing technologies. To generate more insights, we conduct further analyses for various extended modeling cases (e.g., with alliance, competition, and the defense‐level dependent penalty scheme) and find that our main results remain robust. One important insight we have uncovered in this study is that imposing government penalty schemes on cyber‐security issues may do more harm than good; while once it is beneficial to implement, the government should charge the heaviest possible fine. This finding may explain why in the real world, governments basically always adopt a polarized strategy, that is, either do not impose penalty or impose a super heavy penalty, on cyber‐security issues.

AB-tree

There has been an increasing demand for real-time data analytics. Approximate Query Processing (AQP) is a popular option for that because it can use random sampling to trade some accuracy for lower query latency. However, the state-of-the-art AQP system either relies on scan-based sampling algorithms to draw samples, which can still incur a non-trivial cost of table scan, or creates samples of the database in a preprocessing step, which are hard to update. The alternative is to use the aggregate B-tree indexes to support both random sampling and updates in database with logarithmic time. However, to the best of our knowledge, it is unknown how to design an aggregate B-tree to support highly concurrent random sampling and updates, due to the difficulty of maintaining the aggregate weights correctly and efficiently with concurrency. In this work, we identify the key challenges to achieve high concurrency and present AB-tree, an index for highly concurrent random sampling and update operations. We also conduct extensive experiments to show its efficiency and efficacy in a variety of workloads.

Household and Hospitalization Costs of Pediatric Dengue Illness in Colombo, Sri Lanka.

Dengue, a mosquito-borne viral infection that affects millions around the world, poses a substantial economic burden in endemic countries. We conducted a prospective costing study in hospitalized pediatric dengue patients at the Lady Ridgeway Hospital for Children (LRHC), a public pediatric hospital in Colombo district, Sri Lanka, to assess household out-of-pocket and hospitalization costs of dengue in pediatric patients during peak dengue transmission season. Between August and October 2013, we recruited 216 hospitalized patients (aged 0-3 years, 27%; 4-7 years, 29%; 8-12 years, 42%) who were clinically or laboratory diagnosed with dengue. Using 2013 US dollars, household out-of-pocket spending, on average, was US$59 (SD 49) per episode and increased with disease severity (DF, US$52; DHF/DSS, US$78). Pediatric dengue patients received free-of-charge medical care during hospitalization at LRHC, and this places a high financial burden on hospitals. The direct medical cost of hospitalization was US$68 (SD 31.4) for DF episode, and US$122.7 (SD 65.2) for DHF/DSS episode. Yet a hospitalized dengue illness episode still accounted for 20% to 35% of household monthly income due to direct and indirect costs. Additionally, a majority of caregivers (70%) sought outpatient care before hospitalization, most of whom (81%) visited private health facilities. Our findings indicate that hospitalized pediatric dengue illness poses a nontrivial cost burden to households and healthcare systems, emphasizing the importance of preventing and controlling the transmission of dengue in endemic countries.

The Importance of Failure: How Doing Impact Surveys That Fail Saves Trachoma Programs Money.

.Trachoma programs use annual antibiotic mass drug administration (MDA) in evaluation units (EUs) that generally encompass 100,000–250,000 people. After one, three, or five MDA rounds, programs undertake impact surveys. Where impact survey prevalence of trachomatous inflammation—follicular (TF) in 1- to 9-year-olds is ≥ 5%, ≥ 1 additional MDA rounds are recommended before resurvey. Impact survey costs, and the proportion of impact surveys returning TF prevalence ≥ 5% (the failure rate or, less pejoratively, the MDA continuation rate), therefore influence the cost of eliminating trachoma. We modeled, for illustrative EU sizes, the financial cost of undertaking MDA with and without conducting impact surveys. As an example, we retrospectively assessed how conducting impact surveys affected costs in the United Republic of Tanzania for 2017–2018. For EUs containing 100,000 people, the median (interquartile range) cost of continuing MDA without doing impact surveys is USD 28,957 (17,581–36,197) per EU per year, whereas continuing MDA solely where indicated by impact survey results costs USD 17,564 (12,158–21,694). If the mean EU population is 100,000, then continuing MDA without impact surveys becomes advantageous in financial cost terms only when the continuation rate exceeds 71%. For the United Republic of Tanzania in 2017–2018, doing impact surveys saved enough money to provide MDA for > 1,000,000 people. Although trachoma impact surveys have a nontrivial cost, they generally save money, providing EUs have > 50,000 inhabitants, the continuation rate is not excessive, and they generate reliable data. If all EUs pass their impact surveys, then we have waited too long to do them.

Raising Rivals Costs by Customer Diversion: Evidence from Airline Baggage Fees

This study examines the effects of airline baggage fees as a method for diverting high cost passengers to rival airlines that do not charge such fees. We show that the latter in turn must raise their fares, thereby weakening their competitive constraint on carriers with fees and permitting the latter actually to raise their fares. Our empirical evidence focuses on routes where legacy carriers with baggage fees compete with Southwest, which has never had such fees. Consistent with the above implications of the model, we find nontrivial cost and price increases for Southwest and corresponding nontrivial fare increases by legacy carriers on routes on which they overlap with Southwest. These results provide support for the theory of "raising rivals’ costs", this in airlines, but common in other settings where unbundled pricing shifts customers between firms.

Automatic kernel code synthesis and verification

Formal verification of an OS kernel is widely considered a major challenge; however, traditional interactive theorem provers used in OS kernel verification require manually written proofs and come with a non-trivial cost. In this paper, we propose a formal verification framework to build a verifiably correct OS kernel, named iv6, with a high degree of proof automation and a low burden of proof. Using this framework, programmers only need to write the specification as required, and it can be translated into the corresponding implementation of C code automatically. The verification framework can guarantee that the behaviour of the implementation code adheres to its specifications. Iv6 introduces four key ideas to achieve proof automation: its interfaces and corresponding specifications are designed to be finite to avoid unbounded loops or recursion; it separates kernel and user address spaces using a kernel page table isolation approach to simplify reasoning about virtual memory; it partitions the modules of a kernel state machine according to a state transition function to improve verification performance; and to avoid modelling complicated C semantics, it performs verification at the LLVM intermediate representation level.A total of 48 system calls and some high-level system properties in iv6 have been verified using this method. Experience shows that this framework can reduce the impact of human error on kernel development and make the verification of iv6 more efficient and straightforward.

Processor-Tracing Guided Region Formation in Dynamic Binary Translation

Region formation is an important step in dynamic binary translation to select hot code regions for translation and optimization. The quality of the formed regions determines the extent of optimizations and thus determines the final execution performance. Moreover, the overall performance is very sensitive to the formation overhead, because region formation can have a non-trivial cost. For addressing the dual issues of region quality and region formation overhead, this article presents a lightweight region formation method guided by processor tracing, e.g., Intel PT. We leverage the branch history information stored in the processor to reconstruct the program execution profile and effectively form high-quality regions with low cost. Furthermore, we present the designs of lightweight hardware performance monitoring sampling and the branch instruction decode cache to minimize region formation overhead. Using ARM64 to x86-64 translations, the experiment results show that our method achieves a performance speedup of up to 1.53× (1.16× on average) for SPEC CPU2006 benchmarks with reference inputs, compared to the well-known software-based trace formation method, Next Executing Tail (NET). The performance results of x86-64 to ARM64 translations also show a speedup of up to 1.25× over NET for CINT2006 benchmarks with reference inputs. The comparison with a relaxed NETPlus region formation method further demonstrates that our method achieves the best performance and lowest compilation overhead.

SnapFiner: A Page-Aware Snapshot System for Virtual Machines

Virtual machine (VM) snapshot, enabling a VM to be resumed from a previously recorded state, is an essential part of cloud infrastructures. Unfortunately, the snapshot data are likely to be lost due to the high rate of disk failures, so that the associated VM fails to recover properly. To enhance data availability without compromising application performance upon rollback recovery, it is desired to place multiple replicas of snapshot across disperse disks. However, due to the large size of replica, it induces non-trivial storage cost when managing massive snapshots in clouds. In this paper, we investigate this problem and find out that the semantic gap existed between snapshot creation and snapshot storing is one key factor inducing high storage cost. To this end, we propose SnapFiner, a page-aware snapshot system for creating and storing massive snapshot files efficiently. First, SnapFiner acquires a fine-grained page categorization with an in-depth page exploration from three orthogonal views, thereby discovering more pages that can be excluded from the snapshot. Second, SnapFiner varies the number of replicas for different page categories based on a page-aware replication policy, achieving low storage cost without compromising availability and performance. Third, SnapFiner handles the loss of pages either intentionally dropped upon snapshot creation or unexpectedly damaged due to disk failures, enabling proper system execution after rollback recovery. We have implemented SnapFiner on QEMU/KVM to justify its practicality for Linux guests. The experimental results demonstrate that SnapFiner reduces the storage cost by 33 and 69.5 percent respectively compared to our previous work PARS and the naive approach on QEMU/KVM and HDFS.

SEO Underpricing and PCAOB Inspection Reports: Do Investors Use PCAOB Inspection Information?

We examine the association between Public Company Accounting Oversight Board (PCAOB) inspection reports and a firm’s cost of equity capital, measured using seasoned equity offering (SEO) discounting. SEO discounting occurs when the offer price is lower than the prior day’s market price of the firm’s shares and represents ‘money left on the table’ for issuing firms. SEO discounting is a non-trivial cost to an issuing firm, and its occurrence is increasing in both frequency and magnitude. We document an economically significant, positive association between SEO discounting and the use of an auditor found to be deficient by the PCAOB, and this association is most pronounced for clients of smaller, triennially inspected auditors for which few other signals of quality exist. Cross-sectional evidence suggests that, for clients of triennially inspected auditors, this relation is stronger for timelier inspection reports and smaller auditing firms. In conclusion, our evidence is consistent with PCAOB inspections providing meaningful information about audit quality to market participants, particularly for clients of smaller, triennially inspected auditors.

The impacts of rising temperatures on aircraft takeoff performance

Steadily rising mean and extreme temperatures as a result of climate change will likely impact the air transportation system over the coming decades. As air temperatures rise at constant pressure, air density declines, resulting in less lift generation by an aircraft wing at a given airspeed and potentially imposing a weight restriction on departing aircraft. This study presents a general model to project future weight restrictions across a fleet of aircraft with different takeoff weights operating at a variety of airports. We construct performance models for five common commercial aircraft and 19 major airports around the world and use projections of daily temperatures from the CMIP5 model suite under the RCP 4.5 and RCP 8.5 emissions scenarios to calculate required hourly weight restriction. We find that on average, 10–30% of annual flights departing at the time of daily maximum temperature may require some weight restriction below their maximum takeoff weights, with mean restrictions ranging from 0.5 to 4% of total aircraft payload and fuel capacity by mid- to late century. Both mid-sized and large aircraft are affected, and airports with short runways and high temperatures, or those at high elevations, will see the largest impacts. Our results suggest that weight restriction may impose a non-trivial cost on airlines and impact aviation operations around the world and that adaptation may be required in aircraft design, airline schedules, and/or runway lengths.

Quality Improvement in Neurology: Dementia Management Quality Measurement Set Update.

Dementia is a neurologic condition manifested by a substantial decline in multiple cognitive abilities that collectively render a person unable to function at expected levels and progressively impede independent ability to perform everyday activities. For decades, public health officials have warned of the coming tsunami of Alzheimer disease (AD), and dementia has even been characterized as the dominant scourge of modern times, replacing cancer.1 Recently, hopeful signs have appeared, including reports from some longitudinal research studies that incidence of dementia is declining,2 and from the federal government that research funding for AD and other dementias will approach $1 billion USD in 2017.3 The authors thank all the Dementia Management Update Quality Measurement Set Work Group members for their dedication, time, energy, contributions and work that supported the development of this manuscript: Amy E. Sanders, MD, MS, FAAN (American Academy of Neurology); Robert Roca, MD (American Psychiatric Association); Piero Antuono, MD (American Academy of Neurology); Kelly Sullivan, PhD (American Academy of Neurology); Karl Goodkin, MD, PhD, DFAPA (American Psychiatric Association); Donovan Maust, MD, MS (American Psychiatric Association); Michael Lubin, MD, MACP (American College of Physicians); Sam Fazio, PhD (Alzheimer's Association); Ann Knutson (Alzheimer's Association); Robert O'Keefe, MA (Alzheimer's Association); Eric Tangalos, MD, FACP, AGSF, CMD (AMDA–The Society for Post-Acute and Long-Term Care Medicine); Glenn Smith, PhD (American Academy of Clinical Neuropsychology and American Psychological Association); Brian Unwin, MD, FAAFP (American Academy of Family Physicians); Joseph Shega, MD (American Academy of Hospice and Palliative Medicine); Dale Strasser, MD (American Academy of Physical Medicine and Rehabilitation); Michele Grigaitis, DNP, FNP-BC, CNRN (American Association of Neuroscience Nurses); Jerry Johnson, MD (American Geriatric Society); Mary Kathleen Owens, RN MSN, C-NE, RAC-CT (American Health Care Association and Gerontological Advanced Practice Nurses Association); Catherine Piersol, PhD, OTR, FAOTA (American Occupational Therapy Association); Lise McCarthy, PT, DPT, GCS (American Physical Therapy Association); Kathleen Welsh-Bohmer, PhD, ABPP (American Psychological Association); David Webster, MD, MBA (Humana); James Galvin, MD, MPH, FANA (Lewy Body Dementia Association); Daniel Marson, PhD, JD (National Academy of Neuropsychology); Richard Fortinsky, PhD (The Gerontological Society of America); Marsden McGuire, MD (Veteran's Affairs); John Absher, MD (American Academy of Neurology Facilitator); James Nininger, MD (American Psychiatric Association Facilitator); Amy Bennett, JD (American Academy of Neurology Staff); Gina Gjorvad (American Academy of Neurology Staff); Erin Hagen (American Academy of Neurology Staff); Becky Schierman, MPH (American Academy of Neurology Staff); Samantha Shugarman, MS (American Psychiatric Association Staff); and Kristin Kroeger (American Psychiatric Association Staff). The authors also thank Jean O'Keefe for participation and the individuals and organizations who offered public comments.

On‐Shelf Availability, Retail Performance, and External Audits: A Field Experiment

A potential answer to retailer's shelf out‐of‐stocks (OOS), where the item is in the store but customers cannot find it, is to employ third‐party service providers to execute audits and corrections. However, given the nontrivial cost of executing external audits, it is still necessary to assess whether external audits are capable of reducing shelf‐OOS, whether they can be performed in an economical way, and whether the benefits from the audits translate into higher sales. In an effort to address these questions, we partnered with a product manufacturer and a retail service provider and conducted a field experiment in a national retailer's store set. We used transactional data to detect abnormal operations and respond to possible shelf‐OOS by sending auditors to correct empty shelves and incorrect inventory records. At the conclusion of the experiment, we found that Stock Keeping Units in the treatment group were less likely to have shelf‐OOS and inventory record inaccuracies, and that our intervention had a positive effect on sales. Furthermore, we found that the external audit initiative is economically viable since these improvements required low auditing efforts after a transitional period, and in steady state the cost of running the program is a small fraction of the benefits it generates. We discuss the limitations of our study and the implications of our findings for researchers and practitioners.

Plasticity in aggression and the correlated changes in the cost of reproduction in male Drosophila melanogaster

In many animals, the nontrivial cost of ejaculate production has led males to evolve prudent reproductive strategies in the form of precopulatory mating bias and/or cryptic ejaculate allocation. Behaviours determining male reproductive success, such as courtship and aggression, also impose substantial costs potentially selecting for plasticity in these traits. Here, using laboratory-adapted populations of Drosophila melanogaster , we investigated whether males show plasticity in these behaviours in response to the changes in their perception of future risk of competition (generated by varying the number of rivals). We show that males exhibited nonlinear plasticity in their aggressive behaviour. Males subjected to intermediate risk were found to show the maximum level of aggression compared to those subjected to low and high risk. Such plasticity in aggression did not lead to any variation in mating success but significantly increased the cost of reproduction. We also found a similar trend in courtship behaviour. While our results on copulation duration confirmed the previously reported plasticity, we did not find any effect of the treatment on mating latency. To the best of our knowledge this is the first empirical evidence showing plasticity in aggression in response to perceived risk of future competition and its relation to the cost of reproduction.

Dynamic programming based approaches to optimal rooftop unit coordination

While buildings served by multiple rooftop units are widely prevalent in retail and food industries, optimal coordination among rooftop units has received little attention. Currently, most buildings utilize plain feedback or heuristic strategies to determine rooftop unit operations. This article presents a switched dynamic programming based approach for optimal scheduling of rooftop unit operations. Using a mid-sized restaurant served by multiple rooftop units as an example, a switched affine dynamic system model is first presented. The rooftop unit coordination control problem is then formulated as a switched optimal control problem with nontrivial switching cost. A dynamic programming based method is proposed for the solution of the switched optimal control problem, which has reasonable computational complexity and can be implemented either as a one-shot solution or as part of a model predictive control algorithm. To mitigate the growing computational complexity of the proposed algorithm, the approach is extended by proposing a distributed extension of the model predictive control formulation. Finally, a simulation based evaluation of the various formulations is conducted, and the salient features of the formulation are highlighted.

Abstract 137: Anticoagulation clinic provider’s perspective on management of patients on target specific oral anticoagulants: insights from the Veterans Affairs Health Care System

Background: Patients on target specific anticoagulants (TSOACs) such as dabigatran do not require routine laboratory testing and dose adjustment. In the Veterans Health Administration (VHA), anticoagulation clinics (ACCs) may elect to follow and manage patients on TSOACs, but whether it is needed or the optimal duration of follow-up is unknown. Our objective was to assess the perspective of anticoagulation clinic providers on follow-up care for dabigatran patients and to identify site-level practices associated with improved adherence to dabigatran. Methods: We ascertained ACC providers’ perspectives through semi-structured interviews by a single, trained internist. Purposive sampling was utilized to recruit senior ACC providers or supervisors at VHA sites with over 20 patients on dabigatran. We stratified sites into high and low performing sites based on whether sites had ≥ 75% of their patients adherent, based on a proportion-of-days-covered calculation. Data from the interviews was analyzed by 2 reviewers in an iterative process to identify recurrent and unifying themes. Constant comparative method of qualitative data analysis was used to identify best practices across various sites. Results: We interviewed ACC providers from 39 sites - including 18 providers at 16 high-performing sites and 25 providers at 23 low-performing sites. Follow-up practices for dabigatran varied across sites, with 6 sites not providing any follow-up, 14 sites following-up patients for less than 3 months, 9 sites following-up patients for 6 months, and 10 sites following-up patients indefinitely. During these follow-up visits, patients were contacted at regular intervals, mostly via telephone, by ACC providers to provide education, assess side-effects and adherence. Key strategies implemented at high-performing sites compared to low-performing sites included (1) examining adherence to other twice daily medications prior to approving dabigatran (2) education of patients by ACC providers prior to dabigatran initiation (3) continued telephone follow up by ACC staff despite no need for INR checks. Over a third of ACC providers expressed concerns regarding patient adherence to dabigatran. Most common reasons for this concern included its special storage requirements and high incidence of gastrointestinal side effects leading to high discontinuation rates. Conclusion: Dedicated follow-up of patients on dabigatran is associated with improved adherence. A multi-disciplinary approach involving anti-coagulation clinic providers to provide education and follow-up may be beneficial in management of TSOACs. Future work should compare the apparent benefit of this strategy with its non-trivial cost.

Less pain, most of the gain

Information-Centric Networking (ICN) has seen a significant resurgence in recent years. ICN promises benefits to users and service providers along several dimensions (e.g., performance, security, and mobility). These benefits, however, come at a non-trivial cost as many ICN proposals envision adding significant complexity to the network by having routers serve as content caches and support nearest-replica routing. This paper is driven by the simple question of whether this additional complexity is justified and if we can achieve these benefits in an incrementally deployable fashion. To this end, we use trace-driven simulations to analyze the quantitative benefits attributed to ICN (e.g., lower latency and congestion). Somewhat surprisingly, we find that pervasive caching and nearest-replica routing are not fundamentally necessary---most of the performance benefits can be achieved with simpler caching architectures. We also discuss how the qualitative benefits of ICN (e.g., security, mobility) can be achieved without any changes to the network. Building on these insights, we present a proof-of-concept design of an incrementally deployable ICN architecture.

Male Drosophila melanogaster show adaptive mating bias in response to female infection status

Given the non-trivial cost of reproduction for males and substantial variation in female quality, males have been predicted to show mating bias as an evolved strategy. Using a large outbred population of Drosophila melanogaster, we test this prediction and show that males may adaptively bias their mating effort in response to the infection status of females. Given a simultaneous choice between females infected with pathogenic bacteria and sham infected females, males preferentially mated with the latter, who had a higher reproductive output compared to infected females. This may provide evidence for pre-copulatory male mate choice. Assessment of the reproductive behaviour ensured that the observed pattern of mating bias was not due to differences in receptivity between females infected with pathogenic bacteria and sham infected females. Further, there was no evidence for post-copulatory male mate choice measured in terms of copulation duration.

THEBOOKERDECISION AND DISCRIMINATION IN FEDERAL CRIMINAL SENTENCES

I. INTRODUCTION The Sentencing Reform Act, passed by Congress in 1984, established the federal sentencing guidelines. The guidelines were designed to improve standardization in punishments handed out to convicted criminals by limiting what had been federal judges' nearly unfettered discretion in sentencing (Anderson, Kling, and Stith 1999; Stith and Cabranes 1998). For federal crimes committed after November 1, 1987, the Act established that sentences of incarceration were to be determined by a table mapping the severity of the offense (a between 1 and 43) and the defendant's history (a between I and VI) to a potential range of months imprisonment. Table 1 shows the United States Sentencing Commission's (USSC) Sentencing Table. A defendant, for example, with a final offense level of 20 and a criminal history category of IH should, according to the guidelines, be sentenced to somewhere between 41 and 51 months in federal prison. (The actual sentence would be an integer within that range). (1) The Act also abolished parole for federal crimes, though up to 15% of an inmate's sentence could be reduced for good behavior. (2) The Sentencing Reform Act declared that Table 1's guideline ranges were mandatory--federal judges had to incur a nontrivial cost to sentence a defendant outside them. But on January 12, 2005, the United States Supreme Court ruled in the two-part decision U.S. vs. Booker that (a)the sentencing guidelines violated a defendant's constitutional fight to a jury trial; (3) and (b) in order to maintain constitutionality, the guidelines were to be effectively instead of mandatory. (4) Legal observers had expected the overturning of the federal sentencing guidelines system since June 2004, when the Supreme Court decision Blakely v. Washington invalidated Washington state's sentencing guidelines system because it violated a defendant's right to a jury trial (Denniston 2004). By making the sentencing guidelines advisory rather than mandatory, Booker reduced the cost of sentencing outside the guidelines and increased the of federal judges' sentencing decisions. According to Bertrand, Chugh, and Mullainathan (2005), ambiguity is one of three situations in which implicit discrimination is likely to occur. (The other two situations are inattentiveness to task and pressure.) Implicit discrimination, unlike taste-based discrimination (Becker 1957) or statistical discrimination (Aigner and Cain 1977), reflects implicit attitudes that Bertrand, Chugh, and Mullainathan (2005) state are unintentional and outside of the discriminator's awareness. Research indicating implicit discrimination include findings that National Basketball Association referees call fewer fouls against players of their own race (Price and Wolfers 2010), that Major League Baseball umpires are more likely to call strikes when the pitcher is of their own race (Parsons et al. 2007), and that screeners of resumes are more likely to ignore job applications with black names than ones with white names (Bertrand and Mullainathan 2004). Each of these scenarios describes a situation where ambiguity, inattentiveness, or time pressure is a factor, and where a statistically significant amount of discriminatory treatment is detected. (5) This paper tests whether the Booker decision, by increasing the of federal judges' sentencing decisions, increased manifestations of discrimination in accordance with the hypothesis of Bertrand, Chugh, and Mullainathan (2005). Difference-in-difference results show that conditional on a defendant's Table 1 guideline cell, Booker reduced sentences significantly for the default group of defendants--white, male, U.S. citizens who never earned a high school diploma. Female defendants and defendants with terminal high school degrees received significantly larger Booker-related sentence reductions and college graduates received significantly smaller ones. …