cssi/SciSciGPT-SciSciNet huggingface dataset:
On the Economics of Offline Password Cracking

We develop an economic model of an offline password cracker which allows us to make quantitative predictions about the fraction of accounts that a rational password attacker would crack in the event of an authentication server breach. We apply our economic model to analyze recent massive password breaches at Yahoo!, Dropbox, LastPass and AshleyMadison. All four organizations were using key-stretching to protect user passwords. In fact, LastPass' use of PBKDF2-SHA256 with 10^5 hash iterations exceeds 2017 NIST minimum recommendation by an order of magnitude. Nevertheless, our analysis paints a bleak picture: the adopted key-stretching levels provide insufficient protection for user passwords. In particular, we present strong evidence that most user passwords follow a Zipf's law distribution, and characterize the behavior of a rational attacker when user passwords are selected from a Zipf's law distribution. We show that there is a finite threshold which depends on the Zipf's law parameters that characterizes the behavior of a rational attacker — if the value of a cracked password (normalized by the cost of computing the password hash function) exceeds this threshold then the adversary's optimal strategy is always to continue attacking until each user password has been cracked. In all cases (Yahoo!, Dropbox, LastPass and AshleyMadison) we find that the value of a cracked password almost certainly exceeds this threshold meaning that a rational attacker would crack all passwords that are selected from the Zipf's law distribution (i.e., most user passwords). This prediction holds even if we incorporate an aggressive model of diminishing returns for the attacker (e.g., the total value of 500 million cracked passwords is less than 100 times the total value of 5 million passwords). On a positive note our analysis demonstrates that memory hard functions (MHFs) such as SCRYPT or Argon2i can significantly reduce the damage of an offline attack. In particular, we find that because MHFs substantially increase guessing costs a rational attacker will give up well before he cracks most user passwords and this prediction holds even if the attacker does not encounter diminishing returns for additional cracked passwords. Based on our analysis we advocate that password hashing standards should be updated to require the use of memory hard functions for password hashing and disallow the use of non-memory hard functions such as BCRYPT or PBKDF2.
On the Existence of Three Round Zero-Knowledge Proofs

We study the round complexity of zero-knowledge (ZK) proof systems. While five round ZK proofs for \({\mathsf {NP}}\) are known from standard assumptions [Goldreich-Kahan, J. Cryptology’96], Katz [TCC’08] proved that four rounds are insufficient for this task w.r.t. black-box simulation. In this work, we study the feasibility of ZK proofs using non-black-box simulation. Our main result is that three round private-coin ZK proofs for \({\mathsf {NP}}\) do not exist (even w.r.t. non-black-box simulation), under certain assumptions on program obfuscation. Our approach builds upon the recent work of Kalai et al. [Crypto’17] who ruled out constant round public-coin ZK proofs under the same assumptions as ours.
The impact of an integrated Pre-K STEM curriculum on teachers' engineering content knowledge, self-efficacy, and teaching practices

This paper reports a pilot study to determine the potential impact of an integrated STEM curriculum on Pre-K teachers' engineering content knowledge, self-efficacy and teaching practice. Using a randomized control trial design, researchers examined the impact of the curriculum in 17 Pre-K classrooms (8 intervention classrooms, 9 control classrooms) in central Massachusetts. Questionnaires measuring STEM and engineering content knowledge, self-efficacy and teaching practice were administered to participating Pre-K teachers (N=42; 21 intervention, 21 control) in Fall 2017 and again in Spring 2018. Baseline analysis showed no significant differences in engineering and STEM content knowledge, pedagogical content knowledge, or teaching self-efficacy at the start of the pilot study between intervention and comparison classroom teachers. Fidelity of implementation was measured using an observation instrument developed by the project team based on a published implementation science framework. We hypothesized that teachers who implement the integrated STEM curriculum will have significantly higher engineering pedagogical content knowledge and self-efficacy than teachers in the comparison group. As well the teachers who implement the integrated STEM curriculum will show significant gains in their engineering pedagogical content knowledge and self-efficacy in teaching engineering and STEM as a result of their participation.
Flutter instability of a fluid-conveying fluid-immersed pipe affixed to a rigid body

Abstract A set of simplified boundary conditions for a flexible beam connected to a rigid body at one end and free at the other end is presented and applied to the case of a fluid-conveying, fluid-immersed pipe. These boundary conditions represent an analytically tractable approximation to those of a submersible which uses a combination of jet action and flutter instability induced tail motion to produce thrust. The boundary conditions are made non-dimensional, and the effect of the non-dimensional mass of the rigid body on system stability is assessed. The neutral stability of this system is determined within a two-parameter space consisting of the velocity of the fluid within the tail, and the forward speed of the submersible. Equations in the literature, derived using slender-body theory, were used to compute the sign of the thrust produced by the tail and the tail's Froude efficiency for the neutrally stable waveforms of the beam.
DOES MANAGERIAL OPPORTUNISM EXPLAIN THE DIFFERENTIAL PRICING OF LEVEL 3 FAIR VALUE ESTIMATES

Using handâ€ collected Level 3 data, we find that banks near key capital ratios report higher unrealized gains in Level 3 assets, consistent with managers using Level 3 valuations to boost capital ratios. Additionally, we document an incremental pricing discount for Level 3 assets among these firms, suggesting that the pricing discount observed by prior research may not be entirely due to measurement error inherent in Level 3. Furthermore, we observe that this opportunistic behavior diminishes under the new Financial Accounting Standards Board disclosure regime, suggesting that the expanded disclosures may increase the value relevance and reliability of fair value measurements.
When to defend? Optimal territoriality across the Numic homeland

Abstract Explanations for the complex human decisions that lead to territoriality have focused on models of economic defendability. While powerful, these models fail to explain variation in territorial behavior in all cases. To help overcome this limitation, here we offer an approach that synthesizes the logic of economic defendability with a general optimality model from behavioral ecology: the marginal value theorem (MVT). Through the MVT we add considerations of how resource profitability, in addition to abundance, alters the amount of time individuals should spend foraging in order to meet caloric requirements, and how far they should travel between foraging locations. Where and when individuals rely on abundant, but lower profitability resources, they should spend more time foraging and less time traveling, which leads to smaller territories that are easier to defend, and wherein each unit of land has a greater economic value per capita thereby increasing the benefits of economic boundary defense. Numic foragers of the Great Basin and surrounding areas provide an illustrative case study to validate this general ecological model. The results show that individuals exploiting high density but low profitability resources live in smaller territories and have higher rates of resource privatization, thereby explaining societal differences between Northern Paiute and Shoshone bands. Importantly, because defended resource patches are the target of women's foraging, the payoffs to territoriality are likely structured by women's risk averse foraging decisions. We suggest this model is capable of explaining variation in hunter-gatherer territoriality worldwide.
Contextual bandits with surrogate losses: Margin bounds and efficient algorithms

We use surrogate losses to obtain several new regret bounds and new algorithms for contextual bandit learning. Using the ramp loss, we derive a new margin-based regret bound in terms of standard sequential complexity measures of a benchmark class of real-valued regression functions. Using the hinge loss, we derive an efficient algorithm with a $\sqrt{dT}$-type mistake bound against benchmark policies induced by $d$-dimensional regressors. Under realizability assumptions, our results also yield classical regret bounds.
Examining legal and regulatory barriers to climate change adaptation in the coastal zone of the United States

This paper presents an analysis of key legal and regulatory instruments in the United States that impact climate adaptation planning. The analysis is framed within a social-institutional context, m...
Effects of music intervention on inflammatory markers in critically ill and post-operative patients: A systematic review of the literature

Abstract Background Music listening has been shown to reduce anxiety, stress, and patient tolerance of procedures. Music may also have beneficial effects on inflammatory biomarkers in intensive care and post-operative patients, but the quality of evidence is not clear. Objectives We conducted a systematic review to evaluate the effects of music on inflammatory biomarkers in intensive care, and post-operative patients. Methods A comprehensive search of the literature was performed. After screening 1570 references, full text review of 26 studies was performed. Fourteen studies were selected for inclusion. Results Seven studies showed a significant decrease in cortisol levels, but the level of evidence was low. Three studies had low risk of methodological bias, while 11 studies had high risk of bias. Conclusions Music intervention may decrease cortisol levels, but other biomarkers remain unchanged. Given the low level of evidence, further research on music effects on inflammatory biomarkers is needed.
You Must Relax ∼ but How?

(1935). You Must Relax — But How? The Journal of Health and Physical Education: Vol. 6, No. 9, pp. 11-61.
Dose analysis of photobiomodulation therapy on osteoblast, osteoclast, and osteocyte.

The objective of this study was to evaluate the effects of varying light doses on the viability and cellular activity of osteoblasts, osteocytes, and osteoclasts. A light application device was developed to apply 940-nm wavelength light from light-emitting diodes on three cultured cells, MC3T3-E1, MLO-A5, and RANKL-treated RAW264.7 cells. The doses (energy density) on cells were 0, 1, 5, and 7.5 J / cm2. The corresponding light power densities at the cell site were 0, 1.67, 8.33, and 12.5 mW / cm2, respectively, and the duration was 10 min. The results showed that the three cell types respond differently to light and their responses were dose dependent. Low-dose treatment (1 J / cm2) enhanced osteoblast proliferation, osteoclast differentiation, and osteoclastic bone resorption activity. Osteocyte proliferation was not affected by both low- and high-dose (5 J / cm2) treatments. While 1 J / cm2 did not affect viability of all three cell types, 5 J / cm2 significantly decreased viability of osteocytes and osteoclasts. Osteoblast viability was negatively impacted by the higher dose (7.5 J / cm2). The findings suggest that optimal doses exist for osteoblast and osteoclast, which can stimulate cell activities, and there is a safe dose range for each type of cell tested.
Hybrid Codes

A hybrid code can simultaneously encode classical and quantum information into quantum digits such that the information is protected against errors when transmitted through a quantum channel. It is shown that a hybrid code has the remarkable feature that it can detect more errors than a comparable quantum code that is able to encode the classical and quantum information. Weight enumerators are introduced for hybrid codes that allow to characterize the minimum distance of hybrid codes. Surprisingly, the weight enumerators for hybrid codes do not obey the usual MacWilliams identity.
Measuring Group Differences in High‐Dimensional Choices: Method and Application to Congressional Speech

We study the problem of measuring group differences in choices when the dimensionality of the choice set is large. We show that standard approaches suffer from a severe finite‐sample bias, and we propose an estimator that applies recent advances in machine learning to address this bias. We apply this method to measure trends in the partisanship of congressional speech from 1873 to 2016, defining partisanship to be the ease with which an observer could infer a congressperson's party from a single utterance. Our estimates imply that partisanship is far greater in recent years than in the past, and that it increased sharply in the early 1990s after remaining low and relatively constant over the preceding century.
The Dynamics of Electronic Supply Chains and Enterprise Resource Planning Systems: The New Business Challenge

Businesses around the world experience many challenges to acquire raw materials, parts, sub-assemblies, and the other necessary inputs to their production systems. As businesses are all moving into the e-commerce platform to gain market shares, they realize that electronic supply chain management (e-SCM) powered by enterprise resource planning systems (ERPs) are the new norms and no business organization can operate without both in the new world of e-commerce. Little attention has been devoted to e-SCM dynamic with ERP and the challenges they pose to organizations. In the e-commerce environment, e-SCM is among the most important factors to organizational success. Effective e-SCM can enhance competitiveness and increase market share leading a higher profitability. Nevertheless, the new e-SCM professionals and other actors must understand the factors that undergird e-SCM performance, their drivers, and the necessity of fully functional ERPs for an effective e-SCM.
NP-Hardness of Reed--Solomon Decoding, and the Prouhet--Tarry--Escott Problem

Establishing the complexity of bounded distance decoding for Reed--Solomon codes is a fundamental open problem in coding theory, explicitly asked by Guruswami and Vardy [IEEE Trans. Inform. Theory,...
Stargardt macular dystrophy and evolving therapies.

Introduction: Stargardt macular dystrophy (STGD1) is a hereditary retinal degeneration that lacks effective treatment options. Gene therapy, stem cell therapy, and pharmacotherapy with visual cycle...
Inheritance of OCT4 predetermines fate choice in human embryonic stem cells

It is well known that clonal cells can make different fate decisions, but it is unclear whether these decisions are determined during, or before, a cell's own lifetime. Here, we engineered an endogenous fluorescent reporter for the pluripotency factor OCT4 to study the timing of differentiation decisions in human embryonic stem cells. By tracking single-cell OCT4 levels over multiple cell cycle generations, we found that the decision to differentiate is largely determined before the differentiation stimulus is presented and can be predicted by a cell's preexisting OCT4 signaling patterns. We further quantified how maternal OCT4 levels were transmitted to, and distributed between, daughter cells. As mother cells underwent division, newly established OCT4 levels in daughter cells rapidly became more predictive of final OCT4 expression status. These results imply that the choice between developmental cell fates can be largely predetermined at the time of cell birth through inheritance of a pluripotency factor.
Semi-supervised Training for Improving Data Efficiency in End-to-end Speech Synthesis

Although end-to-end text-to-speech (TTS) models such as Tacotron have shown excellent results, they typically require a sizable set of high-quality pairs for training, which are expensive to collect. In this paper, we propose a semi-supervised training framework to improve the data efficiency of Tacotron. The idea is to allow Tacotron to utilize textual and acoustic knowledge contained in large, publicly-available text and speech corpora. Importantly, these external data are unpaired and potentially noisy. Specifically, first we embed each word in the input text into word vectors and condition the Tacotron encoder on them. We then use an unpaired speech corpus to pre-train the Tacotron decoder in the acoustic domain. Finally, we fine-tune the model using available paired data. We demonstrate that the proposed framework enables Tacotron to generate intelligible speech using less than half an hour of paired training data.
Prescription Drug Monitoring Programs, Opioid Abuse, and Crime

We study the spillover effects of prescription drug monitoring programs (PDMPs) on crime, and in the process inform how policies that restrict access to Rx opioids per se within the healthcare system would impact broader non-health domains. In response to the substantial increase in opioid use and misuse in the United States, PDMPs have been implemented in virtually all states to collect, monitor, and analyze prescription opioid data with the goal of preventing misuse and the diversion of controlled substances. Using information on offenses known to law enforcement and arrests from the Uniform Crime Reports (UCR), combined with a difference-in-differences empirical strategy, we find that PDMPs reduced overall crime by 5%. These reductions in crime are associated with both violent and property crimes. This decrease in crime is also reflected by a decrease in crime-related arrests as well as drug-related arrests. Overall, these results provide additional evidence that PDMPs are an effective social policy tool to mitigate some of the negative consequences of opioid misuse, and more broadly indicate that opioid policies can have important spillover effects into other non-health related domains such as crime.
Trends in the diffusion of misinformation on social media

In recent years, there has been widespread concern that misinformation on social media is damaging societies and democratic institutions. In response, social media platforms have announced actions ...
First-Line Gemcitabine and Nab-Paclitaxel Chemotherapy for Localized Pancreatic Ductal Adenocarcinoma

Preoperative chemotherapy provides early treatment of micro-metastases and guaranteed delivery of all components of multimodality therapy for localized pancreatic ductal adenocarcinoma (PDAC). For locally advanced (LA) PDAC, induction chemotherapy is the standard of care. This study evaluated the use of gemcitabine and nab-paclitaxel (Gem/nab-P) as first-line therapy for localized PDAC. Clinicopathologic features, treatment, and outcomes were evaluated for 99 patients with localized PDAC. The patients were staged using previously published criteria as follows: potentially resectable (PR), borderline type A (BR-A) (anatomy amenable to vascular resection), BR-B (biology suspicious for metastatic disease including high CA19-9), BR–C (comorbidities requiring medical optimization), and LA. The 99 patients (PR/BR/LA: 45/14/40) were treated with Gem/nab-P. Clinical staging showed that 20 patients had PR or BR-A disease, whereas 39 patients had BR-B or BR-C disease. The BR-B+C cases included one or more of the following: age of 80 years or older (13%), Eastern Cooperative Oncology Group performance status (ECOG PS) of 2 or more (13%), moderate to severe comorbidities (55%), CA19-9 of 1000 or higher (28%), and suspicion for metastases (21%). The majority of the patients received biweekly Gem/nab-P dosing, which was well tolerated. Pancreatectomy was performed for 12 (60%) of 20 patients with PR+BR-A, 2 (5%) of 39 patients with BR-B+C, and 1 (3%) of 40 patients with LA disease. During a median follow-up period of 26 months, the median overall survival (OS) period was 18 months (95% confidence interval [CI], 15.6–20.5 months) for all the patients, 17 months (95% CI, 14.6–19.5 months) for the unresected patients, and not reached for the resected patients (p = 0.028 for resected vs unresected patients). A significant number of patients with radiographically resectable PDAC albeit aggressive biology (BR-B), medically inoperable conditions (BR-C), or both received biweekly first-line Gem/nab-P. The resection rates were lower for the BR-B/BR-C patients than for the PR/BR-A patients (hazard ratio [HR], 0.43; 95% CI, 0.19–1.00; p = 0.05).
Racial/ethnic differences in the time-varying association between alcohol expectancies and drinking during the transition from childhood to adolescence.

Alcohol expectancies are important determinants of adolescent drinking, but this relationship may differ based on race/ethnicity. This study used time-varying effect modeling to examine racial/ethn...
Global Lysine Acetylation in Escherichia coli Results from Growth Conditions That Favor Acetate Fermentation

ABSTRACT Lysine acetylation is thought to provide a mechanism for regulating metabolism in diverse bacteria. Indeed, many studies have shown that the majority of enzymes involved in central metabolism are acetylated and that acetylation can alter enzyme activity. However, the details regarding this regulatory mechanism are still unclear, specifically with regard to the signals that induce lysine acetylation. To better understand this global regulatory mechanism, we profiled changes in lysine acetylation during growth of Escherichia coli on the hexose glucose or the pentose xylose at both high and low sugar concentrations using label-free mass spectrometry. The goal was to see whether lysine acetylation differed during growth on these two different sugars. No significant differences, however, were observed. Rather, the initial sugar concentration was the principal factor governing changes in lysine acetylation, with higher sugar concentrations causing more acetylation. These results suggest that acetylation does not target specific metabolic pathways but rather simply targets accessible lysines, which may or may not alter enzyme activity. They further suggest that lysine acetylation principally results from conditions that favor accumulation of acetyl phosphate, the principal acetate donor in E. coli. IMPORTANCE Bacteria alter their metabolism in response to nutrient availability, growth conditions, and environmental stresses using a number of different mechanisms. One is lysine acetylation, a posttranslational modification known to target many metabolic enzymes. However, little is known about this regulatory mode. We investigated the factors inducing changes in lysine acetylation by comparing growth on glucose and xylose. We found that the specific sugar used for growth did not alter the pattern of acetylation; rather, the amount of sugar did, with more sugar causing more acetylation. These results imply that lysine acetylation is a global regulatory mechanism that is responsive not to the specific carbon source per se but rather to the accumulation of downstream metabolites.
A Novel Reconfigurable GaN Based Fully Solid-State Microwave Power Module for Communications/Radar Applications

The paper presents as a proof-of-concept (POC) the design, integration, and performance of a novel reconfigurable S-/X-band, GaN based, fully solid-state microwave power module (SSMPM) to enable miniaturization of the overall RF system. The SSMPM includes diplexers, pre-amplifiers, a multistage medium power amplifier, SPDT switches, and CW/Pulsed high-power amplifiers. These components are synergistically integrated such that a single SSMPM is capable of being dynamically reconfigured to function as a CW S-/X-band amplifier for TT&C/science date downlink and as a pulsed X-band amplifier for remote sensing radar onboard a planetary exploration spacecraft. The POC SSMPM is capable of delivering Psat of 39 dBm (8 W CW) at S-band, Psat of 46 dBm (40 W CW) at X-band, and Psat of >50 dBm (>100 W Pulsed) at X-band.
The Muon g − 2 experiment at Fermilab

Precision measurements of the anomalous magnetic moment of the muon aμ are a stringent test of the Standard Model. The last measurement of aμ at Brookhaven National Laboratory (BNL) differs from the Standard Model prediction by 3-4σ: a possible indication of new physics. A successor to that experiment has been constructed at Fermilab, with the aim of reducing the experimental uncertainty by a factor of four to 140 ppb. The measurement technique continues to use the storage ring concept from BNL, with muons circulating in a highly uniform magnetic dipole field. The spin precession frequency is extracted by analysing the modulation of the rate of higher-energy positrons from muon decays, which are detected by 24 calorimeters around the inside of the ring. Compared to the previous experiment, significant improvements have been made in the areas of muon beam preparation, storage ring hardware, field measuring equipment, and detector and electronics systems. In these proceedings, I report on the status of the experiment as of June 2018, presenting an overview of the experiment’s progress, some initial data from the first run, and the anticipated timeline for a new result.
The Role of Accounting Conservatism in Capital Structure Adjustments

This study examines the relation between accounting conservatism and firms’ capital structure adjustments. We find that firms with more conservative financial reporting adjust their capital structu...
Myiasis-induced sepsis: a rare case report of Wohlfahrtiimonas chitiniclastica and Ignatzschineria indica bacteremia in the continental United States.

Rationale The presentation of sepsis and bacteremia in cutaneous and cavitary myiasis is uncommon. We present a patient, residing in a temperate region of the United States, with myiasis and sepsis from the emerging human pathogens Wohlfahrtiimonas chitiniclastica and Ignatzschineria indica. Patient concerns A 37-year-old male patient with an 8-month history of chronic lymphedema and ulcers of the lower left extremity presented with myiasis of the left foot and leg. The patient was initially seen by his family practitioner many times and was prescribed antibiotics which he could not afford. Debridement of the myiasis was not conducted by the family practitioner due to the belief that the patient's current state of myiasis would effectively debride and eventually heal the chronic ulcers along with multiple antibiotic regimens. Over the 8-month period, the patient developed a progressive, painful, necrotizing infection of his lower left extremity. Diagnoses Physical examination clearly showed myiasis of the patient's lower left extremity, believed to be caused by Lucilia sericata (green bottle fly). Blood cultures revealed the presence of Providencia stuartii, W chitiniclastica, and I indica to be the underlying cause of sepsis and bacteremia. Interventions All visible maggots were extracted, debridement of devitalized tissue was performed, and the leg ulcers were wrapped in pH neutral bleach. The patient was initially treated with a broad-spectrum antibiotic regimen of vancomycin, clindamycin, piperacillin, and tazobactam which, following clinical improvement, was de-escalated to cefepime. Outcomes The fly larvae and maggots were removed from the extremity by scrubbing, pulse lavage, and filing away the callused tissue. Additionally, the patient's sepsis and bacteremia, caused by W chitiniclastica and I indica, were successfully treated through antibiotic intervention. Amputation was avoided. Lessons The use of pulse lavage and chlorhexidine-soaked brushes for the removal of cavitary myiasis is an effective and minimally invasive procedure which does not cause additional damage to surrounding tissue. W chitiniclastica and I indica are emerging bacteria that have known association to parasitic fly myiasis in humans and are capable of causing sepsis and/or bacteremia if not accurately identified and treated promptly.
Gradient-Free Multi-Agent Nonconvex Nonsmooth Optimization

In this paper, we consider the problem of minimizing the sum of nonconvex and possibly nonsmooth functions over a connected multi-agent network, where the agents have partial knowledge about the global cost function and can only access the zeroth-order information (i.e., the functional values) of their local cost functions. We propose and analyze a distributed primal-dual gradient-free algorithm for this challenging problem. We show that by appropriately choosing the parameters, the proposed algorithm converges to the set of first order stationary solutions with a provable global sublinear convergence rate. Numerical experiments demonstrate the effectiveness of the proposed method for optimizing nonconvex and nonsmooth problems over a network.
Emergency Undocking Curriculum in Robotic Surgery.

Introduction Traditional instruction for robotic surgery is typically devoid of training that addresses the delineation of interprofessional roles for operating room personnel. An emergency undocking scenario was developed for robotic surgeons with the objectives of improving time to access the patient, provider knowledge of and confidence in emergency undocking, completion of predetermined critical actions, and delineation of operating room personnel roles. Methods Over one month, participants joined in three sessions: Session 1 - formative, Session 2 - review, and Session 3 - summative. Embedded standardized participants (ESPs) represented members of the interprofessional team. Prior to entering the operating room for Sessions 1 and 3, trainees were asked to complete a confidence survey and multiple choice questionnaire (MCQ) for knowledge assessment. Participants were randomized to one of two cases and participated in the reciprocal case for the final session four weeks later. Following Session 1, participants underwent an educational intervention, including the proper technique for emergency undocking, emphasis on operating room personnel roles, and hands-on practice. Obstetrics and Gynecology (OBGYN) residents in post-graduate Years 2-4 and attending physicians with robotics privileges at Summa Health Akron Campus or Cleveland Clinic Akron General Medical Center were invited to participate. A total of 21 participants enrolled and finished the study. Results Among the 21 participants, there was a significant increase in the baseline level of knowledge (p-value=0.001) and in the confidence of surgeons when faced with an emergency undocking after the completion of our curriculum (p-value=0.003). Additionally, an improvement in the undocking times (p-value<0.001) and an increase in the critical actions performed (p-value=0.002) were observed. Conclusion The results of this study demonstrate that incorporating this curriculum into the training programs of robotic surgeons is an effective way to improve the surgical skill of emergency undocking.
Learning Spatially-correlated Temporal Dictionaries for Calcium Imaging

Calcium imaging has become a fundamental neural imaging technique, aiming to recover the individual activity of hundreds of neurons in a cortical region. Current methods (mostly matrix factorization) are aimed at detecting neurons in the field-of-view and then inferring the corresponding time-traces. In this paper, we reverse the modeling and instead aim to minimize the spatial inference, while focusing on finding the set of temporal traces present in the data. We reframe the problem in a dictionary learning setting, where the dictionary contains the time-traces and the sparse coefficient are spatial maps. We adapt dictionary learning to calcium imaging by introducing constraints on the norms and correlations of the time-traces, and incorporating a hierarchical spatial filtering model that correlates the time-trace usage over the field-of-view. We demonstrate on synthetic and real data that our solution has advantages regarding initialization, implicitly inferring number of neurons and simultaneously detecting different neuronal types.
Fostering adaptive marine aquaculture through procedural innovation in marine spatial planning

Abstract Worldwide, as wild-caught commercial fisheries plateau and human demands for protein increase, marine aquaculture is expanding. Much marine aquaculture is inherently adaptable to changing climatic and chemical conditions. Nevertheless, siting of marine aquaculture operations is subject to competing environmental, economic, and social demands upon and priorities for ocean space, while some forms of marine aquaculture can also impose other externalities on marine systems, such as pollution from wastes (nutrients) and antibiotics, consumption of wild fish as food, and introduction of non-native or genetically modified species. As a result, governmental policy decisions to promote both marine aquaculture that can adapt to a changing ocean and adaptive governance for that aquaculture can become contested, requiring attention to their social legitimacy. This article explores how the law can promote the adaptability of marine aquaculture to climate change and ocean acidification—adaptive marine aquaculture—while still preserving key rule-of-law values, such as public participation and accountability. Perhaps most obviously, law can establish substantive requirements for marine aquaculture that minimize its impacts, promoting marine resilience overall. However, to foster truly adaptive marine aquaculture, including adaptive governance institutions, coastal nations should also procedurally reform their marine spatial planning efforts to legally connect the procedures for aquaculture permitting, marine spatial planning (MSP), and adaptive management. The goals for such connections, moreover, should be to mandate new forums for public participation and creative collaboration, promote experimentation with accountability that leads to increased knowledge, and foster the emergence of adaptive governance regarding the use of marine space.
Closed-Loop Control of Active Sensing Movements Regulates Sensory Slip

Active sensing involves the production of motor signals for the purpose of acquiring sensory information [1-3]. The most common form of active sensing, found across animal taxa and behaviors, involves the generation of movements-e.g., whisking [4-6], touching [7, 8], sniffing [9, 10], and eye movements [11]. Active sensing movements profoundly affect the information carried by sensory feedback pathways [12-15] and are modulated by both top-down goals (e.g., measuring weight versus texture [1, 16]) and bottom-up stimuli (e.g., lights on or off [12]), but it remains unclear whether and how these movements are controlled in relation to the ongoing feedback they generate. To investigate the control of movements for active sensing, we created an experimental apparatus for freely swimming weakly electric fish, Eigenmannia virescens, that modulates the gain of reafferent feedback by adjusting the position of a refuge based on real-time videographic measurements of fish position. We discovered that fish robustly regulate sensory slip via closed-loop control of active sensing movements. Specifically, as fish performed the task of maintaining position inside the refuge [17-22], they dramatically up- or downregulated fore-aft active sensing movements in relation to a 4-fold change of experimentally modulated reafferent gain. These changes in swimming movements served to maintain a constant magnitude of sensory slip. The magnitude of sensory slip depended on the presence or absence of visual cues. These results indicate that fish use two controllers: one that controls the acquisition of information by regulating feedback from active sensing movements and another that maintains position in the refuge, a control structure that may be ubiquitous in animals [23, 24].
Regio- and stereoselective oxidative difunctionalization of alkylidene cyclohexenes

Abstract Stereo- and regioselective oxidation of alkylidene cyclohexenes affords novel γ-lactones, δ-lactones and related structures.
A SIMPLE PROCEDURE FOR PREPARING ANNULATED P-BENZOQUINONES. IMPROVED SYNTHESIS OF 1,4-DIHYDRO-1,4-METHANONAPHTHALENE-5,8-DIONE

Abstract A simple and efficient two-step, one-pot synthesis of substituted 1,4-dihydro-1,4-methanonaphthalene-5,8-diones is reported. This synthesis, which utilizes readily available starting materials and inexpensive reagents, can be used to prepare 1a-1c in 70–90% overall yield. This procedure was extended successfully to prepare a more highly complex annulated p-benzoquinone i.e., 8.
A new synthetic route to perfluoroalkylidene-α,ω-bisphosphonates

Abstract The UV irradiation of a mixture of (EtO)2POP(OEt)2 and I(CF2)nI (n = 3,4, 6) or I(CF2)nP(O)(OEt)2 (n = 1, 2) results in the corresponding bisphosphonites or mixed phosphonite-phosphonates, respectively, which on oxidation by Me3COOH afforded the perfluoroalkylidene-α,ω-bisphosphonates in 64–77% isolated yields.
Demonstration of Microwave Multiplexed Readout of DC-Biased Superconducting Nanowire Detectors

Superconducting nanowires are widely used as sensitive single photon detectors with wide spectral coverage and high timing resolution. We describe a demonstration of an array of dc-biased superconducting nanowire single photon detectors read out with a microwave multiplexing circuit. In this design, each individual nanowire is part of a resonant LC circuit where the inductance is dominated by the kinetic inductance of the nanowire. The circuit also contains two parallel plate capacitors, one of them is in parallel with the inductor and the other is coupled to a microwave transmission line that carries the signals to a cryogenic low-noise amplifier. All of the nanowires are connected via resistors to a single dc bias line that enables the nanowires to be current biased close to their critical current. When a photon hits a nanowire, it creates a normal hotspot that produces a voltage pulse across the LC circuit. This pulse rings down at the resonant frequency of the LC circuit over a time period that is fixed by the quality factor. We present measurements of an array of these devices and an evaluation of their performance in terms of frequency and time response.
Hybrid organic-inorganic solids for heterogeneous asymmetric catalysis

This paper provides a short review of recent progress in the design and synthesis of chiral organic–inorganic hybrid solids and their applications in heterogeneous asymmetric catalysis. Homochiral hybrid solids containing catalytic sites can be readily prepared by linking appropriately designed chiral bridging ligands with metal ion or metal cluster nodes. Heterogeneous asymmetric catalysts with enantioselectivity as high as 99.2 and turnover number (TON) as high as 20,000 have been obtained based on these hybrid organic–inorganic solids. The modular nature of the present approach promises to lead to a variety of practically useful heterogeneous asymmetric catalysts for many organic transformations.
Towards creating an extended metabolic model (EMM) for E. coli using enzyme promiscuity prediction and metabolomics data

Metabolic models are indispensable in guiding cellular engineering and in advancing our understanding of systems biology. As not all enzymatic activities are fully known and/or annotated, metabolic models remain incomplete, resulting in suboptimal computational analysis and leading to unexpected experimental results. We posit that one major source of unaccounted metabolism is promiscuous enzymatic activity. It is now well-accepted that most, if not all, enzymes are promiscuous—i.e., they transform substrates other than their primary substrate. However, there have been no systematic analyses of genome-scale metabolic models to predict putative reactions and/or metabolites that arise from enzyme promiscuity. Our workflow utilizes PROXIMAL—a tool that uses reactant–product transformation patterns from the KEGG database—to predict putative structural modifications due to promiscuous enzymes. Using iML1515 as a model system, we first utilized a computational workflow, referred to as Extended Metabolite Model Annotation (EMMA), to predict promiscuous reactions catalyzed, and metabolites produced, by natively encoded enzymes in Escherichia coli. We predict hundreds of new metabolites that can be used to augment iML1515. We then validated our method by comparing predicted metabolites with the Escherichia coli Metabolome Database (ECMDB). We utilized EMMA to augment the iML1515 metabolic model to more fully reflect cellular metabolic activity. This workflow uses enzyme promiscuity as basis to predict hundreds of reactions and metabolites that may exist in E. coli but may have not been documented in iML1515 or other databases. We provide detailed analysis of 23 predicted reactions and 16 associated metabolites. Interestingly, nine of these metabolites, which are in ECMDB, have not previously been documented in any other E. coli databases. Four of the predicted reactions provide putative transformations parallel to those already in iML1515. We suggest adding predicted metabolites and reactions to iML1515 to create an extended metabolic model (EMM) for E. coli.
How conspicuous are peacock eyespots and other colorful feathers in the eyes of mammalian predators

Colorful feathers have long been assumed to be conspicuous to predators, and hence likely to incur costs due to enhanced predation risk. However, many mammals that prey on birds have dichromatic visual systems with only two types of color-sensitive visual receptors, rather than the three and four photoreceptors characteristic of humans and most birds, respectively. Here, we use a combination of multispectral imaging, reflectance spectroscopy, color vision modelling and visual texture analysis to compare the visual signals available to conspecifics and to mammalian predators from multicolored feathers from the Indian peacock (Pavo cristatus), as well as red and yellow parrot feathers. We also model the effects of distance-dependent blurring due to visual acuity. When viewed by birds against green vegetation, most of the feathers studied are estimated to have color and brightness contrasts similar to values previously found for ripe fruit. On the other hand, for dichromat mammalian predators, visual contrasts for these feathers were only weakly detectable and often below detection thresholds for typical viewing distances. We also show that for dichromat mammal vision models, the peacock’s train has below-detection threshold color and brightness contrasts and visual textures that match various foliage backgrounds. These findings are consistent with many feathers of similar hue to those studied here being inconspicuous, and in some cases potentially cryptic, in the eyes of common mammalian predators of adult birds. Given that birds perform many conspicuous motions and behaviors, this study suggests that mammalian predators are more likely to use other sensory modalities (e.g., motion detection, hearing, and olfaction), rather than color vision, to detect avian prey. This suggests new directions for future behavioral studies and emphasizes the importance of understanding the influence of the sensory ecology of predators in the evolution of animal coloration.
Synthesis of monoalkenylated crown ethers and C-pivot cryptands†

The synthesis of two N-(2-allyloxy)ethyl-substituted diaza-crowns and two C-pivot (allyloxy)methyl-substi-tuted cryptands is described. Controlled etherization of N,N-bis(2-hydroxyethyl)-4,13-diaza-18-crown-6 with allyl bromide and sodium hydride gave N-(2-allyloxy)ethyl-N-(2-hydroxyethyl)-4,13-diaza-18-crown-6 in a good yield. This macrocycle was reacted with sodium hydride and tetrahydrofurfuryl chloride or 3,3-dimeth-ylbutyl tosylate to give expected N-(2-allyloxy)ethyl-N'-tetrahydrofurfuryloxy)ethyl-[or (3,3-dimethylbutoxy)-ethyl]-substituted products 3 or 4. 6,13-Dimethylenyl-14-crown-4 (9) and 9,19-dimethylenyl-20-crown-6 (10) were treated with mercuric acetate, followed by sodium borohydride in strong base to give macrocyclic diols 11 and 12, respectively. These diols were reacted with sodium hydride and the ditosylate derivative of allyloxymethyl-substituted triethyleneglycol 13 to produce the C-pivot (allyloxy)methyl-substituted macrotri-cycles 6 and 7.
Epoxide and diol epoxide adducts of polycyclic aromatic hydrocarbons at the exocyclic amino group of deoxyguanosine

Abstract Synthesis and separation of the diastereomeric trans N 2 -2′-deoxyguanosine adducts of tetrahydrophenanthrene 3,4-epoxide and benzo[a]pyrene 7,8-diol 9,10-epoxide (benzylic hydroxyl group and epoxide oxygen trans), as well as the incorporation of the former into the pentanucleotide TpApG * pApT, are described.
Sol−Gel Preparation of Bi2MxV1-xO5.5-δ Films (M = Cu, Nb; x = 0.1, 0.3)

The sol−gel deposition of Bi2Cu0.1V0.9O5.35 (BiCuVOx) and Bi2Nb0.3V0.7O5.5 (BiNbVOx) films up to 2 μm thick onto quartz substrates is reported. Films of both materials can be deposited, initially crack-free, on quartz. Bi2Nb0.3V0.7O5.5 films on quartz remain homogeneous and defect-free at all temperatures, but Bi2Cu0.1V0.9O5.35 films develop grooves and voids between grains during thermal processing. A number of additives were tested with the BiCuVOx precursor solutions for their effects on film morphology and were found to give no improvement in the film quality. Process temperature and alkoxide/hydrolysis water ratio were varied as well. Preliminary results for deposition of the films onto porous alumina substrates are reported.
Full Characterization and Some Reactions of 1-(2-Adamantyl)-3-(1-adamantyl)aziridin-2-one

We found that 1-(2-adamantyl)-3-tert-butylaziridin-2-one (5a) is unstable. It slowly decomposes at room temperature, although detectable by IR spectroscopy (1840 cm−1 band in CCl4). On the other hand, a closely related analogue, 1-(2-adamantyl)-3-(1-adamantyl)aziridin-2-one (5b), is very stable, in concurrence with an earlier report [1]. We fully characterized aziridinone 5b, identified its thermal decomposition products (7 and 8) and reacted it with two aprotic ionic (tBuO− and HO−) and one protic non-ionic nucleophile (benzylamine). All three products (9b, 10, and 11) result from exclusive cleavage of the lactam (1-2) bond.
A novel monoalkylation of symmetrical α-diones

Abstract An efficient method has been developed for the synthesis of monoalkylated 1,2-diones by using steric approach control. The dihydropyrazine 2 prepared from 2,3-butanedione and 1,2-diamino-2-methylpropane is selectively deprotonated on the less hindered methyl group to give an anion which is alkylated with alkyl iodides and activated bromides. In situ hydrolysis of the alkylated dihydropyrazines gives monoalkylated diones 4 in good yield.
Dorsal ruffles enhance activation of Akt by growth factors

In fibroblasts, platelet-derived growth factor (PDGF) and epidermal growth factor (EGF) stimulate the formation of actin-rich, circular dorsal ruffles (CDRs) and phosphatidylinositol 3-kinase (PI3K)-dependent phosphorylation of Akt. To test the hypothesis that CDRs increase synthesis of phosphorylated Akt1 (pAkt), we analyzed the contributions of CDRs to Akt phosphorylation in response to PDGF and EGF. CDRs appeared within several minutes of growth factor addition, coincident with a peak of pAkt. Microtubule depolymerization with nocodazole blocked CDR formation and inhibited phosphorylation of Akt in response to EGF but not PDGF. Quantitative immunofluorescence showed increased concentrations of Akt, pAkt and phosphatidylinositol (3,4,5)-trisphosphate (PIP3), the phosphoinositide product of PI3K that activates Akt, concentrated in CDRs and ruffles. EGF stimulated lower maximal levels of pAkt than did PDGF, which suggests that Akt phosphorylation requires amplification in CDRs only when PI3K activities are low. Accordingly, stimulation with low concentrations of PDGF elicited lower levels of Akt phosphorylation, which, like responses to EGF, were inhibited by nocodazole. These results indicate that when receptor signaling generates low levels of PI3K activity, CDRs facilitate local amplification of PI3K and phosphorylation of Akt.This article has an associated First Person interview with the first author of the paper.