cssi/SciSciGPT-SciSciNet huggingface dataset:
Using Social Dynamics to Make Individual Predictions: Variational Inference with a Stochastic Kinetic Model

Social dynamics is concerned primarily with interactions among individuals and the resulting group behaviors, modeling the temporal evolution of social systems via the interactions of individuals within these systems. In particular, the availability of large-scale data from social networks and sensor networks offers an unprecedented opportunity to predict state-changing events at the individual level. Examples of such events include disease transmission, opinion transition in elections, and rumor propagation. Unlike previous research focusing on the collective effects of social systems, this study makes efficient inferences at the individual level. In order to cope with dynamic interactions among a large number of individuals, we introduce the stochastic kinetic model to capture adaptive transition probabilities and propose an efficient variational inference algorithm the complexity of which grows linearly — rather than exponentially— with the number of individuals. To validate this method, we have performed epidemic-dynamics experiments on wireless sensor network data collected from more than ten thousand people over three years. The proposed algorithm was used to track disease transmission and predict the probability of infection for each individual. Our results demonstrate that this method is more efficient than sampling while nonetheless achieving high accuracy.
"On-the-fly" solution techniques for stochastic Petri nets and extensions

High level modeling representations, such as stochastic Petri nets, frequently generate very large state spaces and corresponding state transition rate matrices. We propose a new steady state solution approach that avoids explicit storing of the matrix in memory. This method does not impose any structural restrictions on the model, uses Gauss Seidel and variants as the numerical solver, and uses less memory than current state of the art solvers. An implementation of these ideas shows that one can realistically solve very large, general models in relatively little memory.
Novel Methods for Optically Measuring Whitecaps under Natural Wave-Breaking Conditions in the Southern Ocean

AbstractTraditional methods for measuring whitecap coverage using digital video systems mounted to measure a large footprint can miss features that do not produce a high enough contrast to the background. Here, a method for accurately measuring the fractional coverage, intensity, and decay time of whitecaps using above-water radiometry is presented. The methodology was developed using data collected in the Southern Ocean under a wide range of wind and wave conditions. Whitecap quantities were obtained by employing a magnitude threshold based on the interquartile range of the radiance or reflectance signal from a single channel. Breaking intensity and decay time were produced from the integration of and the exponential fit to radiance or reflectance over the lifetime of the whitecap. When using the lowest magnitude threshold possible, radiometric fractional whitecap coverage retrievals were consistently higher than fractional coverage from high-resolution digital images, perhaps because the radiometer capt...
Internal Labor Markets in Equilibrium

Traditional models of promotion have difficulty explaining why many firms do not favor internal employees for advancement. I develop a new model to explain this phenomenon. My model generates an equilibrium where some, but not all, ex ante identical firms recruit strictly internally. These firms employ higher quality entry-level workers, since they hire supervisors exclusively from their lower ranks. The scarcity of high-quality workers limits the use of this strategy. I derive several testable predictions on wage-tenure profile differences across firms with varying recruitment practices and confirm these predictions using matched employer-employee data from the United Kingdom.
Color thermometry of electronic devices

A novel method for obtaining dynamic, real time, high spatial resolution temperature distribution over surfaces of electronic components is presented. The thermometric medium is a liquid crystalline coating deposited on the devices to be measured. It scatters incident white light into bright colors in response to the temperature of the device. Each scattered color uniquely represents a temperature. The response is in milliseconds. The process is reversible and has high spatial resolution over any size area.
MOM SURFACE REPLACEMENT: THROW THE BABY OUT WITH THE BATH WATER – OPPOSES

Metal-on-metal hip arthroplasty has fallen out of favor because of complications arising from the articulation, namely metal sensitivity and accelerated wear. These complications can lead to early/mid-term failures from pain, osteolysis, implant loosening, and pseudotumor formation. However, it has become clearer that MOM total hip arthroplasty behaves differently from MOM hip resurfacing, due to the additional junctions present in the total hip arthroplasty setting. Garbuz et al have demonstrated in a randomised controlled trial that MOM THA has significantly higher metal ion levels than MOM hip resurfacing. Clinical results of a MOM THA compared with a MOM HR using the same articulation also demonstrate significantly poorer results with the THA. Newer literature has also shown that corrosion occurs at the taper junction of a THA due to the dissimilar metals. These corrosion products are likely what are causing a higher incidence of adverse local tissue reactions. Because a hip resurfacing implant is a monoblock ball, there is no taper junction of dissimilar metals that has the potential for corrosion. National registry studies have also demonstrated a difference in the survival curves of MOM THA vs. hip resurfacing. MOM HR, in select patient groups, has a lower revision rate at 10 years than traditional metal-on-poly THA. Thus, to eliminate MOM hip resurfacing as a treatment option is akin to “throwing the baby out with the bathwater”, which the presenter deeply opposes.
Smart unit care for pre fall detection and prevention

Generally falls may occur from moving or resting postures. This may include slipping from bed and fall from a sitting, or from running or walking. The pre-fall is a non-equilibrium state of human position that may lead to serious injuries, and may negatively impact the quality life condition, particularly for elders. Physical disabilities resulting from the fall incidences may lead to high costs involved with the healing process. In this work, an embedded sensor system using Arduino micro-controller was utilized to coordinate the data received from accelerometer and gyroscope. For a given threshold voltage and fall pattern, the fall decision is made by the microcontroller, citing an incoming fall. The study addresses the number of sensors to be coordinated for enhancing probability of receiving a real fall. Sensors are suggested to be placed on the human body within a belt, and safety devices at human body as well as incorporated in a smart room will be coordinated with the processor commands. Near 150 ms time frame was detected from the simulation results, suggesting a safety device to be triggered and activated for protection within this time frame. This paper discusses the research parameters such as response time for the device activation and interfacing the microcontroller to airbag switch, and means of activating the safety devices within the sharp edges in the smart unit care to minimize the impact of the fall injuries.
Comparison of multigrid algorithms for high-order continuous finite element discretizations

Summary We present a comparison of different multigrid approaches for the solution of systems arising from high-order continuous finite element discretizations of elliptic partial differential equations on complex geometries. We consider the pointwise Jacobi, the Chebyshev-accelerated Jacobi, and the symmetric successive over-relaxation smoothers, as well as elementwise block Jacobi smoothing. Three approaches for the multigrid hierarchy are compared: (1) high-order h-multigrid, which uses high-order interpolation and restriction between geometrically coarsened meshes; (2) p-multigrid, in which the polynomial order is reduced while the mesh remains unchanged, and the interpolation and restriction incorporate the different-order basis functions; and (3) a first-order approximation multigrid preconditioner constructed using the nodes of the high-order discretization. This latter approach is often combined with algebraic multigrid for the low-order operator and is attractive for high-order discretizations on unstructured meshes, where geometric coarsening is difficult. Based on a simple performance model, we compare the computational cost of the different approaches. Using scalar test problems in two and three dimensions with constant and varying coefficients, we compare the performance of the different multigrid approaches for polynomial orders up to 16. Overall, both h-multigrid and p-multigrid work well; the first-order approximation is less efficient. For constant coefficients, all smoothers work well. For variable coefficients, Chebyshev and symmetric successive over-relaxation smoothing outperform Jacobi smoothing. While all of the tested methods converge in a mesh-independent number of iterations, none of them behaves completely independent of the polynomial order. When multigrid is used as a preconditioner in a Krylov method, the iteration number decreases significantly compared with using multigrid as a solver. Copyright © 2015 John Wiley & Sons, Ltd.
The economics of commercial demand response for spinning reserve

Demand response (DR) for spinning reserve may be appropriate for customers whose operational constraints preclude participation in energy and capacity DR programs. We investigate the private business case of an aggregator providing spinning reserve in California across customer end uses and business segments. Revenues are calculated using end use level hourly load profiles. With average annual revenue of $$\sim $$ $35/kW, steady end uses (e.g., lighting) are more than twice as profitable as seasonal end uses (e.g., cooling) because spinning reserve is needed year-round. Business segments with longer operating hours, such as groceries or lodging, have more revenue potential. Total costs for participation would need to be under $250/kW for many end uses and business segments to have payback periods less than 5 years, which is plausible given equipment cost data from California’s Automated Demand Response programs. Avoided carbon emission damages from using DR instead of fossil fuel generation for spinning reserve could justify incentives for DR resources.
Nod2 and Nod2 -regulated microbiota protect BALB/c mice from diet-induced obesity and metabolic dysfunction

Genetics plays a central role in susceptibility to obesity and metabolic diseases. BALB/c mice are known to be resistant to high fat diet (HFD)-induced obesity, however the genetic cause remains unknown. We report that deletion of the innate immunity antibacterial gene Nod2 abolishes this resistance, as Nod2 −/− BALB/c mice developed HFD-dependent obesity and hallmark features of metabolic syndrome. Nod2 −/− HFD mice developed hyperlipidemia, hyperglycemia, glucose intolerance, increased adiposity, and steatosis, with large lipid droplets in their hepatocytes. These changes were accompanied by increased expression of immune genes in adipose tissue and differential expression of genes for lipid metabolism, signaling, stress, transport, cell cycle, and development in both adipose tissue and liver. Nod2 −/− HFD mice exhibited changes in the composition of the gut microbiota and long-term treatment with antibiotics abolished diet-dependent weight gain in Nod2 −/− mice, but not in wild type mice. Furthermore, microbiota from Nod2 −/− HFD mice transferred sensitivity to weight gain, steatosis, and hyperglycemia to wild type germ free mice. In summary, we have identified a novel role for Nod2 in obesity and demonstrate that Nod2 and Nod2-regulated microbiota protect BALB/c mice from diet-induced obesity and metabolic dysfunction.
Why regulate private firm disclosure and auditing

Private firms face differing financial disclosure and auditing regulations around the world. In the US and Canada, for example, private firms are generally neither required to disclose their financial results nor have their financial statements audited. By contrast, many firms with limited liability in most other countries are required to file at least some financial information publicly and are also required to have their financial statements audited. This paper discusses and analyzes the reasons for differential financial reporting regulation of private firms. We first discuss various definitions of a private firm. Next, we examine theoretical arguments for regulating the financial reporting of these firms, particularly related to public disclosure and auditing. We then provide new survey-based evidence of firms’ and standard setters’ views of regulation. We conclude by identifying future research opportunities.
Controlling Conflicts of Interest: A Tale of Two Industries

Large corporate conglomerates are being formed in many industries. Although a conglomerate may be able to use its multiple businesses to offer better products or services or lower prices, conglomeration can also create conflicts of interest within a corporation, harming consumers. Other researchers and observers have long been aware of these conflicts of interest, however, this Article’s empirical analyses identify what specific characteristics of a conglomerate cause conflicts of interest to actually result in harm to consumers. In doing so, the Article also guides policymakers regarding how to regulate conflicts of interest. This Article examines two industries – financial services and the media – in which conglomeration has created similar conflicts of interest. Much attention is being focused on the conflicts of interest of many research analysts who recommend stocks for investors. These research analysts work for financial conglomerates that also have investment banking departments. As a result, these analysts have faced great pressure to write positive research reports about companies from which their employers seek investment banking business. Unfortunately, this pressure has resulted in analysts giving biased recommendations in favor of these companies, harming millions of investors who rely on these recommendations. In response to this bias, the Securities and Exchange Commission, other regulatory organizations, and courts have recently imposed billions of dollars in fines and civil settlements and a number of rules and regulations on research analysts and their employers. These reforms are targeted at reducing and publicly disclosing analysts’ conflict of interests. The situation of another group of professionals – movie critics who work for media conglomerates – is parallel to that of these research
PRE-OPERATIVE PLANNING: LEST WE FORGET

Introduction: Acetabular component positioning, offset, combined anteversion, leg length, and soft tissue envelope around the hip plays an important role in hip function and durability. In this paper we will focus on acetabular positioning of the cup. Technique: The axis of the pelvis is identified intra-operatively as a line drawn from the highest point of the iliac crest to the middle of the greater trochanter. Prior to reaming the acetabulum, an undersized trial acetabular component is placed parallel and inside the transverse ligament, inside the anterior column and projecting posterior to the axis of the pelvis. This direction is marked and the subsequent reaming and final component placement is performed in the same direction. The lateral opening is judged based on 45-degree angle from the tear drop to the lateral margin of the acetabulum on anteroposterior pelvic radiographs. The final anteversion of the cup is adjusted based on increase or decrease of lumbar lordosis and combined anteversion. Methods: Anteroposterior pelvic radiographs of 100 consecutive patients undergoing posterior THR between September 2010 and March 2011 with this method were evaluated for cup inclination angle and anteversion using EBRA software. Results: There were no malalignment or dislocation. The mean cup inclination angle and anteversion were 41 ± 5.1 degrees (range 37.1 – 48.4) and 22.1 ± 4.8 degrees (range 16.6 – 29.3), respectively. Conclusion: This is a reproducible method of cup positioning and with proper femoral component position, restores leg length, offset, combined anteversion, and balances soft tissue around the hip. These factors affect the incidence of dislocation, infection, reduced wear, and durability.
Free energy of defects in chemoepitaxial block copolymer directed self-assembly: effect of pattern density and defect position

Block copolymers (BCPs) can phase separate to form periodic structures with small spacings, making BCPs an attractive option for furthering the ability of optical lithography. Chemoepitaxy is a method of directed self-assembly (DSA) that uses preferential pinning stripes to guide the BCP. The periodicity of the underlayer’s pinning stripe compared to the periodicity of the BCP is defined as the density multiplication. In this study molecular dynamics simulations are used to explore the effect density multiplication and pinning stripe position has on the free energy difference between a defective and defect-free BCP film. For all defect orders the highest free energies were obtained when a pinning stripe was located directly under or adjacent to the terminating block. At high density multiplications, the defects were found to approach the free energy of the same defect on an unpatterned underlayer. For all density multiplications and pinning stripe positions the free energy of defective films is significantly higher than that of defect-free films, suggesting the presence of defects in experiment is likely due to kinetic entrapment of defects. Free energy initially increases with increasing defect size, but was found to level off and even decrease for the largest defects in this work.
NETWORK-ENSEMBLE COMPARISONS WITH STOCHASTIC REWIRING AND VON NEUMANN ENTROPY.

Assessing whether a given network is typical or atypical for a random-network ensemble (i.e., network-ensemble comparison) has widespread applications ranging from null-model selection and hypothesis testing to clustering and classifying networks. We develop a framework for network-ensemble comparison by subjecting the network to stochastic rewiring. We study two rewiring processes---uniform and degree-preserved rewiring---which yield random-network ensembles that converge to the Erdos--Renyi and configuration-model ensembles, respectively. We study convergence through von Neumann entropy (VNE)---a network summary statistic measuring information content based on the spectra of a Laplacian matrix---and develop a perturbation analysis for the expected effect of rewiring on VNE. Our analysis yields an estimate for how many rewires are required for a given network to resemble a typical network from an ensemble, offering a computationally efficient quantity for network-ensemble comparison that does not require...
A Characterization of Undirected Graphs Admitting Optimal Cost Shares

In a seminal paper, Chen et al. [7] studied cost sharing protocols for network design with the objective to implement a low-cost Steiner forest as a Nash equilibrium of an induced cost-sharing game. One of the most intriguing open problems to date is to understand the power of budget-balanced and separable cost sharing protocols in order to induce low-cost Steiner forests.
Delivery by drone: An evaluation of unmanned aerial vehicle technology in reducing CO2 emissions in the delivery service industry

Abstract This research paper estimates carbon dioxide (CO2) emissions and vehicle-miles traveled (VMT) levels of two delivery models, one by trucks and the other by unmanned aerial vehicles (UAVs), or “drones.” Using several ArcGIS tools and emission standards within a framework of logistical and operational assumptions, it has been found that emission results vary greatly and are highly dependent on the energy requirements of the drone, as well as the distance it must travel and the number of recipients it serves. Still, general conditions are identified under which drones are likely to provide a CO2 benefit – when service zones are close to the depot, have small numbers of stops, or both. Additionally, measures of VMT for both modes were found to be relatively consistent with existing literature that compares traditional passenger travel with truck delivery.
Learning from Conformance Quality Failures That Triggered Product Recalls: The Role of Direct and Indirect Experience

A product recall is an observable external quality failure and a source of significant potential loss to firms as well as a threat to public safety. While such failures can be a motivation for organizational learning, little is known about the extent to which recalls can be a source of learning experience. Using econometric modeling, we investigate to what extent firms learn from conformance quality failures using a panel sample of U.S. food product recalls conducted by 125 publically traded firms between 2004 and 2013. We differentiate between direct (i.e., internal locus of failure) and indirect (i.e., supplier locus of failure and industry recalls) sources of experience and examine the main and interaction effects on the likelihood of future recalls. The results indicate that experience derived from internal and supplier failures reduces the potential for future recalls, while industry recalls have no significant main effect. We also find evidence of substitution effects between internal and supplier failures, suggesting that there are diminishing learning effects at higher levels of both of these types of failures. This finding suggests that the variety and volume of information as well as uncertainty regarding outcomes can overwhelm firm information processing capabilities at higher levels of these failure types and that additional resources should be allocated to encourage adequate learning. Finally, internal failures and industry recalls act as learning complements, which may indicate that internal quality failures become more relevant when industry peers also experience quality failures.
A 3D Ginibre Point Field

We introduce a family of three-dimensional random point fields using the concept of the quaternion determinant. The kernel of each field is an n-dimensional orthogonal projection on a linear space of quaternionic polynomials. We find explicit formulas for the basis of the orthogonal quaternion polynomials and for the kernel of the projection. For number of particles $$n \rightarrow \infty $$ , we calculate the scaling limits of the point field in the bulk and at the center of coordinates. We compare our construction with the previously introduced Fermi-sphere point field process.
PRE- AND POST-OPERATIVE OPIOID USE: A CLEAR AND PRESENT PROBLEM

The United States is in the midst of an opioid epidemic, with the World Health Organization reporting that American9s consume 99% of the world9s supply of hydrocodone and 83% of the world9s oxycodone. Additionally, pre-operative opioid use has been associated with worse clinical outcomes and higher rates of complications following TKA. This is especially important in the TKA population given that approximately 15% of patients are either dissatisfied or very dissatisfied at least one year after their TKA procedure. Given the concerning rise is opioid use the American Academy of Orthopaedic Surgeons (AAOS) has recently released an information statement with practice recommendations for combating this excessive and inappropriate opiate use. However, little is known regarding peri-operative opioid use for TKA patients. Therefore, the purpose of this study was to: 1) identify rates of opioid use prior to primary TKA, 2) evaluate post-operative trends in opioid use throughout the year following TKA and 3) identify risk factors for prolonged opioid use following TKA. Overall, 31% of TKA patients are prescribed opioids within 3-months prior to TKA; this percentage has increased over 9% during the years included in this study. Pre-operative opioid use was most predictive of increased refills of opioids following TKA, however, other intrinsic patient characteristics were also predictive of prolonged opioid use. These characteristics remained predictive after controlling for opioid user status. The increasing rates of opioid prescribing prior to TKA are concerning, especially given literature concluding opioids have minimal effect on pain or function in patients with osteoarthritis and pre-operative opioid use is associated with poor outcomes and more complications following TKA. This data provides an important baseline for opioid use trends following TKA that can be used for future comparison and identifies risk factors for prolonged use that will be helpful to prescribers as the AAOS works to decreased opioid use, misuse and abuse within the United States. Our data on THA and unicompartmental arthroplasty is similar with an increase in pre-THA use of 9% with 38% receiving narcotics within 3 months of surgery and continued use in opioid users (9 times non-opioid users at 12 months).
Fine-scale variation in microclimate across an urban landscape shapes variation in mosquito population dynamics and the potential of Aedes albopictus to transmit arboviral disease.

Most statistical and mechanistic models used to predict mosquito-borne disease transmission incorporate climate drivers of disease transmission by utilizing environmental data collected at geographic scales that are potentially coarser than what mosquito populations may actually experience. Temperature and relative humidity can vary greatly between indoor and outdoor environments, and can be influenced strongly by variation in landscape features. In the Aedes albopictus system, we conducted a proof-of-concept study in the vicinity of the University of Georgia to explore the effects of fine-scale microclimate variation on mosquito life history and vectorial capacity (VC). We placed Ae. albopictus larvae in artificial pots distributed across three replicate sites within three different land uses–urban, suburban, and rural, which were characterized by high, intermediate, and low proportions of impervious surfaces. Data loggers were placed into each larval environment and in nearby vegetation to record daily variation in water and ambient temperature and relative humidity. The number of adults emerging from each pot and their body size and sex were recorded daily. We found mosquito microclimate to significantly vary across the season as well as with land use. Urban sites were in general warmer and less humid than suburban and rural sites, translating into decreased larval survival, smaller body sizes, and lower per capita growth rates of mosquitoes on urban sites. Dengue transmission potential was predicted to be higher in the summer than the fall. Additionally, the effects of land use on dengue transmission potential varied by season. Warm summers resulted in a higher predicted VC on the cooler, rural sites, while warmer, urban sites had a higher predicted VC during the cooler fall season.
Kähler structures on spaces of framed curves

We consider the space $${\mathcal {M}}$$ of Euclidean similarity classes of framed loops in $${\mathbb {R}}^3$$ . Framed loop space is shown to be an infinite-dimensional Kahler manifold by identifying it with a complex Grassmannian. We show that the space of isometrically immersed loops studied by Millson and Zombro is realized as the symplectic reduction of $${\mathcal {M}}$$ by the action of the based loop group of the circle, giving a smooth version of a result of Hausmann and Knutson on polygon space. The identification with a Grassmannian allows us to describe the geodesics of $$\mathcal {M}$$ explicitly. Using this description, we show that $${\mathcal {M}}$$ and its quotient by the reparameterization group are nonnegatively curved. We also show that the planar loop space studied by Younes, Michor, Shah and Mumford in the context of computer vision embeds in $${\mathcal {M}}$$ as a totally geodesic, Lagrangian submanifold. The action of the reparameterization group on $${\mathcal {M}}$$ is shown to be Hamiltonian, and this is used to characterize the critical points of the weighted total twist functional.
Enhancing Web Search Using Query-Based Clusters and Labels.

Current web search engines, such as Google, Bing, and Yahoo!, rank the set of documents S retrieved in response to a user query and display the URL of each document D in S with a title and a snippet, which serves as an abstract of D. Snippets, however, are not as useful as they are designed for, which is supposed to assist its users to quickly identify results of interest, if they exist. These snippets fail to (i) provide distinct information and (ii) capture the main contents of the corresponding documents. Moreover, when the intended information need specified in a search query is ambiguous, it is very difficult, if not impossible, for a search engine to identify precisely the set of documents that satisfy the user's intended request without requiring additional inputs. Furthermore, a document title is not always a good indicator of the content of the corresponding document. All of these design problems can be solved by our proposed query-based cluster and labeler, called QCL. QCL generates concise clusters of documents covering various subject areas retrieved in response to a user query, which saves the user's time and effort in searching for specific information of interest without having to browse through the documents one by one. Experimental results show that QCL is effective and efficient in generating high-quality clusters of documents on specific topics with informative labels.
Health Plan Payment in Medicaid Managed Care: A Hybrid Model of Regulated Competition

Abstract Medicaid, the government program for providing health insurance to low-income and disabled Americans, is the largest health insurer in the United States with more than 73 million enrollees. It is also the sector of the US public health insurance system that relies most heavily on the tools of regulated competition with more than 60% of its enrollees enrolled in a private health plan in 2014 (CMS, 2016). However, regulated competition in Medicaid differs from the typical model, emphasizing the tools of competitive procurement, such as competitive bidding, the threat of exclusion from the market, and auto-assignment of enrollees to plans, to attempt to induce efficiency instead of relying primarily on the forces of consumer demand. In this chapter we discuss how Medicaid combines the tools of competitive procurement with the tools of regulated competition and some potential consequences of this hybrid model.
An Industrial Challenge to Control System Educators

Abstract Most engineers earn their livelihood in industry. Technological advancements and industry trends guarantee that these engineers will face significant challenges during their career. Meanwhile, advancements in control theory insure that many diverse control techniques will be used. This paper identifies seven challenges for educators who are preparing tomorrow’s control system engineers.
The University of Illinois Bicycle Project

Abstract It is asserted that contemporary education at many levels, including dynamic systems education, is in a saturation state as students concentrate on memorization and seem to retain less and yet educators strain to push more material and more abstractions into courses. In an attempt to relieve the perceived saturation effect, the author initiated the project approach with bicycles in dynamic systems courses as a pedagogical strategy. At the University of Illinois the use of bicycles has evolved over an eight year period, and bicycles as projects have been used at course levels from sophomore machine dynamics up to graduate thesis research in system dynamics. The “hands on” inductive activities compliment the traditional deductive lecture and fact/knowledge level memorization modes of teaching systems theoretic material. The bicycle project approach is based in large part upon the scientific method of hypothesis and experimentation.
Complications of the Kock Pouch

Over the past 41/2 years, 395 consecutive Kock pouch procedures have been performed by the urology faculty at the University of Southern California School of Medicine as an alternative to conventional cutaneous urinary diversion. This article reviews the early and late complications experienced in the 386 patients surviving the operation and describes in detail modifications in surgical technique designed to reduce the complication rate and the subsequent need for re-operation. We remain convinced that construction from ileum of a low-pressure, high-capacity internal reservoir with continent and nonrefluxing valves as originally described by Kock remains the ultimate technique for patients requiring permanent urinary diversion or for those requiring conversion from a pre-existing form of diversion.
Technique for Placement of a Totally Implantable Venous Access Device

A totally implantable venous access system is described which greatly improved the ability to gain long-term venous access in selected patients. The external jugular approach has been demonstrated to be a safe and simple technique. The only major problem associated with the implantable venous access system was the development of one-way catheter occlusions. A number of methods for restoring catheter patency have been advocated. The use of streptokinase appears to be the most reliable and was found effective in this study. Importantly, however, catheter sepsis has been virtually eliminated with this totally implantable system.
Human Colorectal Carcinoma: Patterns of Sensitivity to Chemotherapeutic Agents in the Human Tumor Stem Cell Assay

The human tumor stem cell assay (HTSCA) was applied to 103 primary and metastatic colorectal carcinomas. Thirty-four carcinomas could not be evaluated for colony formation (clonogenicity) because of microbial contamination. Of the remaining 69 carcinomas, 18 (26%) demonstrated clonal growth in vitro. Colony formation did not correlate with the clini-copathologic stage of the tumor, the histological grade of the tumor, the method used to disperse the solid tumors into single cells (mechanical or enzymatic), or cell viability (exclusion of trypan-blue) prior to plating. The in vitro chemotherapy sensitivity data of the 18 tumors which formed colonies indicated that most tumors were generally resistant to chemotherapeutic drugs and that a few tumors were sensitive to multiple agents. Use of the human tumor stem cell assay may facilitate an individualized approach to clinical chemotherapy of colorectal carcinoma for certain patients.
Augmentation of Lymphoproliferative Activity of Tumor-Bearing BALB/c Mice to Soluble Tumor Antigens by Surgical Manipulation: The Possible Role of Macrophages

Lymphoproliferative activity was assessed by 3H-thymidine incorporation in spleen cells of mammary tumor bearing BALB/c mice, mice which had their tumors surgically removed, and mice with sham surgery after stimulation in vitro with a soluble extract of syngeneic tumor antigens. Surgical removal of tumors caused an average of 65 % decline in reactivity at 5 days postoperative as compared to reactivity of animals with their tumors intact. Sham surgery caused an average of 33% elevation in reactivity. Macrophages added to cultures at spleen cell/macrophage ratio of 100: 1 caused an average 171%, 59%, and 12% elevation in the activity of surgery, tumor-bearing, and sham-surgery animals, respectively. Surgical manipulation of tumor-bearing mice, therefore, augmented in situ the ability of spleen cells to exhibit lymphoproliferative activity to a soluble syngeneic antigenic extract in vitro, possibly by a mechanism involving the activation of macrophages and requiring the presence of a sizable antigenic load.
Statistical Tradeoffs between Generalization and Suppression in the De-identification of Large-Scale Data Sets.

Data sets containing private information about individuals must satisfy privacy standards before being publicly released. One such standard, k-anonymity, reduces the probability of the re-identification of individuals by requiring that rare combinations of personally-identifiable information be represented by at least k distinct individuals. Records that violate this standard must be altered, which can lead to significant distortion of the statistical properties of the data set. In this paper, we discuss improvements to two techniques used to achieve k-anonymity, generalization and suppression, that confer k-anonymity while better preserving the statistical properties of an educational data set taken from a massive online open course platform, edX.
Market design for living-donor organ exchanges: an economic policy perspective

Within the last decade, the use of living-donor kidney exchanges for transplants has emerged as a cross-disciplinary success for medical doctors and ethicists, market design economists, and computer scientists. This paper describes the fronts on which these efforts have been successful and what needs to be done further to increase their impact. This paradigm is also partially being applied to liver exchanges. There are other organs for which living donation is possible and gains from exchange can be much bigger than for kidneys. Recent academic work on single-graft liver and dual-donor organ exchanges for lobar lung, dual-graft liver, and simultaneous liver-kidney transplantation are also discussed.
Peer effects in the demand for property rights : experimental evidence from urban Tanzania

This paper investigates the presence of endogenous peer effects in the adoption of formal property rights. Using data from a unique land titling experiment held in an unplanned settlement in Dar es Salaam, the analysis finds a strong, positive impact of neighbor adoption on the household's choice to purchase a land title. The paper also shows that this relationship holds in a separate, identical experiment held a year later in a nearby community, as well as in administrative data for more than 160,000 land parcels in the same city. Although the exact channel is undetermined, the evidence points toward complementarities in the reduction in expropriation risk, as peer effects are strongest between households living close to each other and there is some evidence that peer effects are strongest for households most concerned with expropriation. The results show that, within the Tanzanian context, households will reinforce each other’s decisions to enter formal tenure systems.
Adaptive Identification of Stochastic Transmission Channels

Abstract In this paper, we address the problem of identifying stochastic transmission channels that are characterized by bounded linear stochastic operators ₤ω,t( ), such that £ ω , t ( ) = L t ( ) + R ω ( ) where Lt( ) are linear, deterministic and time-varying operators and Kω( ) are Linear random operators. That is, Lt( ) produces deterministic propagation losses and Rω( ) produces zero mean random fluctuations of the propagated or scattered signals. The probing signals are completely known and their specification is a part of the design of the channel identification experiments. We show that minimization of the mean square error between the propagation channel output and assumed reference model output identifies the deterministic part of the propagation operator. The problem can be solved by least squares identification of ARMA parameters. In the scalar case, the correlation function of the random operator Rω( ) can be calculated from the correlation function of estimation error and additive noise. Both of these functions can be measured directly. In the vector/matrix case, the components of the correlation matrix of the random operator can be identified through use of specially designed probing signals. Hence, in both cases we have a method for identification of the second order statistics of a stochastic transmission channel.
Double and Single ITCZs with and without Clouds

AbstractA major bias in tropical precipitation over the Pacific in climate simulations stems from the models’ tendency to produce two strong distinct intertropical convergence zones (ITCZs) too often. Several mechanisms have been proposed that may contribute to the emergence of two ITCZs, but current theories cannot fully explain the bias. This problem is tackled by investigating how the interaction between atmospheric cloud-radiative effects (ACREs) and the large-scale circulation influences the ITCZ position in an atmospheric general circulation model. Simulations are performed in an idealized aqua-planet setup and the longwave and the shortwave ACREs are turned off individually or jointly. The low-level moist static energy (MSE) is shown to be a good predictor of the ITCZ position. Therefore, a mechanism is proposed that explains the changes in MSE and thus ITCZ position due to ACREs consistently across simulations. The mechanism implies that the ITCZ moves equatorward if the Hadley circulation strengt...
Colorectal surveillance after segmental resection for young-onset colorectal cancer: is there evidence for extended resection?

Aim Although sporadic colorectal cancer (CRC) usually occurs in patients over 50, recent evidence suggests that the incidence is increasing in younger patients. Such patients are theoretically at high risk of metachronous neoplasia and may be candidates for extended, prophylactic, colectomy. This study aimed to define the risk of metachronous cancer/adenomas during follow-up of younger patients who underwent segmental colectomy for CRC. Method A CRC database was used to identify patients aged less than 50 who underwent surgery for CRC between 1994 and 2010.. Patients diagnosed with hereditary cancer or inflammatory bowel disease were excluded. The primary endpoints were frequency of extended resections, and the rates of metachronous cancer and high-risk adenomas during follow-up. Results There were 284 young patients with a resectable primary tumor, of which 280 (98.6%) underwent segmental resection, 3 (1%) extended and 1 (0.4%) local. Endoscopic follow-up was available for 150 of the patients who had segmental colectomy, with mean age 42.6 years (±5.8) at diagnosis and median follow-up time of 68 months (IQR, 45-105). Out of these 150 patients, 4 (2.7%) developed metachronous colonic adenocarcinoma at 24, 71, 151 and 228 months after index surgery. Thirty additional patients had at least one adenoma identified during surveillance, and 3 had sessile serrated polyps. Out of the 3 patients undergoing extended resection, none had metachronous cancer or advanced adenomas at an average follow up of 17 years. Conclusion A segmental colectomy or proctectomy is adequate treatment for patients presenting with colorectal cancer under age 50. . This article is protected by copyright. All rights reserved.
Histopathologic and Cytologic Follow-Up in High Risk Male Patients with Unsatisfactory Anal Cytology.

Objective. Anal cytology is being increasingly used as part of anal cancer screening in patients at high risk for anal neoplasia. Most studies in anal cytology have focused on correlating the abnormal anal Pap smear with histopathologic outcomes. The aim of this study was to document histopathologic or repeat anal cytology outcomes in patients with unsatisfactory cytology. Materials and Methods. Unsatisfactory anal Pap tests in high risk male patients were correlated with follow-up histopathologic diagnoses or cytology. Results. 1205 anal tests were performed during the study period and 214 (17.8%) were unsatisfactory. Adequate follow-up cytology was available in 75 cases and revealed epithelial cell abnormality (ECA) in 40% [30/75] (atypical squamous cells of undetermined significance (ASCUS) [20%] and low-grade squamous intraepithelial lesions (LGSIL) [20%]) and was negative for intraepithelial lesion or malignancy (NILM) in 60% [45/75] of cases. 28.7% of unsatisfactory Pap smears had unsatisfactory repeat cytology. Histopathological follow-up on these unsatisfactory Pap smears revealed anal intraepithelial neoplasia (AIN) 1 and AIN 2/3 or 2/3
Data Scientists in Software Teams: State of the Art and Challenges

The demand for analyzing large scale telemetry, machine, and quality data is rapidly increasing in software industry. Data scientists are becoming popular within software teams, e.g., Facebook, LinkedIn and Microsoft are creating a new career path for data scientists. In this paper, we present a large-scale survey with 793 professional data scientists at Microsoft to understand their educational background, problem topics that they work on, tool usages, and activities. We cluster these data scientists based on the time spent for various activities and identify 9 distinct clusters of data scientists, and their corresponding characteristics. We also discuss the challenges that they face and the best practices they share with other data scientists. Our study finds several trends about data scientists in the software engineering context at Microsoft, and should inform managers on how to leverage data science capability effectively within their teams.
On the renormalization of Hamiltonians

Abstract We introduce a novel method for the renormalization of the Hamiltonian operator in Quantum Field Theory in the spirit of the Wilson renormalization group. By a series of unitary transformations that successively decouples the high-frequency degrees of freedom and partially diagonalizes the high-energy part, we obtain the effective Hamiltonian for the low energy degrees of freedom. We successfully apply this technique to compute the 2-loop renormalized Hamiltonian in scalar λ φ 4 theory.
Using mobile phones as acoustic sensors for high-throughput mosquito surveillance

Diseases spread by mosquito bites – like malaria, dengue and Zika – kill over half a million people each year. Many of these diseases have no cure, and those that do often face the problem of drug resistance. As such, the most effective way to control these diseases is to reduce the number of mosquitoes in the affected area. Yet, this kind of control strategy relies on knowing which species of mosquito that spread diseases to humans and where they are found. Most current methods to monitor mosquitoes are laborious, and need expensive equipment and highly trained people. This makes them less suitable for resource-poor areas, which typically have the highest levels of mosquito-borne diseases. However, scientists have known for many decades that one can identify species of mosquito by the pitch of sound they make when they fly. The challenge was to find instruments that could record these sounds clearly enough to measure the pitch, but that were still cheap and sturdy enough to use in mosquito-infested environments. Mukundarajan et al. now report that the microphones in ordinary mobile phones are sensitive enough to accurately record the whining buzz of a mosquito, even in the presence of background noise. First, techniques were developed that allow anybody to record mosquitoes on virtually any mobile phone model – including smartphones and basic flip-phones. Next, the sounds of 20 species of mosquito that spread diseases to humans were recorded – more than in any previous study. When other recordings made using various phones were compared to this collection of sounds, the correct species was automatically identified for two thirds of the recordings. This meant that, together with volunteers who were trained for 15 minutes, Mukundarajan et al. could use mobile phone recordings to map mosquito species inside a National Park in California and a village in Madagascar more efficiently than with any conventional method. There are over five billion mobile phones in use today. Even a small percentage of mobile users recording mosquito sounds could thus provide a tremendous amount of data. As more and more people contribute recordings, Mukundarajan et al. hope to be able to make real-time global maps of mosquito distributions. These could then be used to design better strategies to control mosquitoes and combat mosquito-borne diseases.