cssi/SciSciGPT-SciSciNet huggingface dataset:
Direction Finding with Mutually Orthogonal Antennas

Electromagnetic direction finding using a set of three mutually orthogonal antennas is studied. The vector effective height concept from antenna theory is employed to develop three direction finding algorithms for use with the proposed antenna arrangement. The first algorithm estimates the direction-of-arrival by computing a vector that is perpendicular to the locus of the instantaneous electric field vector measured at the origin of the coordinate system. The second and third algorithms are based on the well-known maximum likelihood and MUSIC algorithms. For all algorithms we assume a narrowband signal model and that multiple incident waves can be separated in the frequency domain before processing each signal separately. In simulation, each algorithm successfully located the direction-of-arrival to within 2° for circularly polarized waves at SNR ≥ 35dB.
Performance analysis of a packet switch with demand assignment capabilities

A packet switch based on the idea of assignment on demand has been proposed and analyzed. The switch model assumes that switch connection can be reconfigured by a control unit according to a switching schedule. The switching schedule may either be provided by an algorithm which will optimize performance or can be a sequence of fixed switching configurations. In both cases, queuing analysis has been carried out. In the analysis, it is assumed that buffer capacity is limited and that the transmission period (frame length) is variable. The analysis is based on a discrete time Markov chain from which state probabilities of the transmission period have been derived. Delay and throughput characteristics with different buffer sizes are presented and compared for each of the above cases. >
Sensitivity of a Clinical Decision Rule and Early Computed Tomography in Aneurysmal Subarachnoid Hemorrhage.

Introduction Application of a clinical decision rule for subarachnoid hemorrhage, in combination with cranial computed tomography (CT) performed within six hours of ictus (early cranial CT), may be able to reasonably exclude a diagnosis of aneurysmal subarachnoid hemorrhage (aSAH). This study’s objective was to examine the sensitivity of both early cranial CT and a previously validated clinical decision rule among emergency department (ED) patients with aSAH and a normal mental status.
Friction at the Atomic Scale

This paper reviews simple theoretical models and recent experimental advances concerned with frictional processes at the atomic scale. Two simple models for wearless interfacial friction are discussed, the independent oscillator (IO) model, and the Frenkel-Kontorova model. The IO model is compared with molecular dynamics calculations between films of close-packed alkane molecules. Atomic force microscope studies of friction are discussed, and the role of other tip-based proximal probe techniques in understanding tribological processes is reviewed.
Relationship of Phytate, Phytate-Mineralizing Bacteria, and Beta-Propeller Phytase Genes along a Coastal Tributary to the Chesapeake Bay

Phytate is often the most common and recalcitrant form of organic P in soils. Given that extracellular phytase activities are attributed to soil microorganisms, the distribution and characterization of phytate-mineralizing bacteria (PMB) and quantification of phytate genes across an environmental gradient can address questions related to the degree of relative recalcitrancy of phytate P and microbial response to phytate loading. In this study, we analyzed paired sediment and water samples from different sites along a stretch of East Creek, a coastal tributary to the Chesapeake Bay, for the abundance of PMB as well as β-propeller phytase (BPP) genes, a gene for the most common of the phytase enzymes, using culture-dependent and -independent methods. We found that a larger proportion of isolates from sites near the headwaters were PMB than at the mouth of the creek. Our quantitative polymerase chain reaction (qPCR) results show that the total number of bacteria (both with and without BPP genes) in water and sediment samples was highest at the agricultural headwaters but decreased significantly at wetland sites. Similarly, 16S rRNA-normalized BPP copies show that the abundance of bacteria capable of phytate degradation was about four orders of magnitude higher in water than in sediment. These results probably indicate that the presence of phytate promotes the proliferation of phytate-degrading microorganisms with a potentially higher rate of phytate degradation in water than in sediments. Overall, these results provide important insights into phytate loading and PMB abundance in a coastal tributary and P export to the Chesapeake Bay.
Light Induced Carbon Dioxide Reduction by Water at Binuclear ZrOCoII Unit Coupled to Ir Oxide Nanocluster Catalyst

An all-inorganic polynuclear unit consisting of an oxo-bridged binuclear ZrOCoII group coupled to an iridium oxide nanocluster (IrOx) was assembled on an SBA-15 silica mesopore surface. A photodeposition method was developed that affords coupling of the IrOx water oxidation catalyst with the Co donor center. The approach consists of excitation of the ZrOCoII metal-to-metal charge-transfer (MMCT) chromophore with visible light in the presence of [Ir(acac)3] (acac: acetylacetonate) precursor followed by calcination under mild conditions, with each step monitored by optical and infrared spectroscopy. Illumination of the MMCT chromophore of the resulting ZrOCoII–IrOx units in the SBA-15 pores loaded with a mixture of 13CO2 and H2O vapor resulted in the formation of 13CO and O2 monitored by FT-IR and mass spectroscopy, respectively. Use of 18O labeled water resulted in the formation of 18O2 product. This is the first example of a closed photosynthetic cycle of carbon dioxide reduction by water using an all-ino...
Study on Factors of Influencing Farmers' Agrarian Inward Transferring Willingness in Hainan

The factors of influencing farmers' agrarian inward transferring willingness were analyzed by the established Logit model based on the surveyed data from farmer households of six counties and cities in Hainan from six aspects of farmer family's income,land resources endowment,manpower resources status,farmer's personal feature,agricultural production and management risk and agricultural policy to provide a reference for development of optimum-scale management and culture of new operating main body in agriculture.Results:Farmer family's income,land resources endowment and personal feature have the significant influence on willingness of farmer's agrarian inward transferring but agricultural subsidy level,technical service,production management risk and family's employment situation have no obvious influence on willingness of farmer's agrarian inward transferring.Per capita contract farmland status has the U influence on willingness of farmer's agrarian inward transferring.Willingness of farmer's agrarian inward transferring decreases with optimization of labor force and land allocation before per capita contract farmland area reaches a certain scale but willingness of farmer's agrarian inward transferring strengthens continuously when per capita contract farmland area exceeds a certain scale.Per capita income level of farmer households,proportion of agricultural management income and amount of labor force have the positive influence on willingness of farmer's agrarian inward transferring.Education level of head of a farmer household has the negative influence on willingness of farmer's agrarian inward transferring.The topographic feature and farmer's nationality have the significant influence on willingness of farmer's agrarian inward transferring also.
Advanced MRI strategies for assessing spinal cord injury

Advanced magnetic resonance (MR) approaches permit the noninvasive quantification of macromolecular, functional, and physiological properties of biological tissues. In this chapter, we review the application of advanced MR techniques to the spinal cord. Macromolecular properties of the spinal cord can be studied using magnetization transfer (MT) MR, diffusion tensor imaging (DTI), Q-space diffusion spectroscopy, and selective detection of myelin water. The functional and metabolic status of the spinal cord can be studied using functional MRI (fMRI), perfusion imaging, and magnetic resonance spectroscopy (MRS). Finally, we consider the outlook for advanced MR studies in persons in whom metal hardware has been implanted to stabilize the cord. In spite of the spinal cord's diminutive size, its location deep within the body, and constant motion, recent work shows that the spinal cord can be studied using these advanced MR approaches.
Does the Program Manager Matter? New Public Management and Defense Acquisition:

Past efforts to reform defense acquisition have been based in New Public Management assumptions that certain attributes of program managers (PMs), such as their training and experience levels, are important for improving outcomes. This article documents an effort to examine the relationship between such PM attributes and program outcomes using data drawn from annual Department of Defense Selected Acquisition Reports for major defense acquisition programs between 1997 and 2010. The findings provide little support for these assumptions. They point instead to the potential for institutionalist theories to explain acquisition outcomes, which can enable more nuanced reform policies in the future.
Protein Disulfide Isomerase Plays An Important Role in Beta2 Integrin-Mediated Neutrophil Recruitment During Vascular Inflammation

Abstract 17 Cell surface protein disulfide isomerase (PDI), a prototypic thiol isomerase, plays an important role in regulating integrin-mediated cellular functions. Although surface PDI has been reported to regulate L-selectin shedding on neutrophils, its role in neutrophil recruitment during vascular inflammation has not been explored. In this paper, we present novel findings on how neutrophil PDI regulates neutrophil recruitment into the site of vascular inflammation. Using real-time microscopy with cell-impermeable inhibitors for PDI (bacitracin or function-blocking antibodies), we demonstrated that inhibition of PDI reduces adhesion of human blood neutrophils to TNF-alpha-stimulated human umbilical vein endothelial cells (HUVECs) under venous shear. There was no additive effect on neutrophil adhesion in a combination of blocking anti-PDI and anti-beta2 antibodies, suggesting that surface PDI regulates beta2 integrin-mediated neutrophil adhesion to TNF-alpha-activated HUVECs under shear. Further, bacitracin and blocking anti-PDI antibodies diminished alphaMbeta2 integrin-mediated neutrophil adhesion to intercellular adhesion molecule-1 (ICAM-1)-coated surfaces under static conditions. When PDI gene is knocked down in neutrophil-like HL60 cells by shRNA, alphaMbeta2 activation and cell adhesion to TNF-alpha-activated HUVECs under shear were significantly reduced. High resolution confocal microscopy and immunoprecipitation assay revealed that surface PDI interacts with alphaMbeta2 integrin and that such interaction was enhanced by neutrophil activation and inhibited by bacitracin, a thiol isomerase inhibitor. Exogenous PDI equivalently bound to CHO cells stably expressing alphaMbeta2 or alphaLbeta2 when those cells were treated with Mn2+, whereas PDI binding was significantly reduced when the active site CGHC residues on PDI were mutated. Using multi-channel fluorescence intravital microscopy, we demonstrated that inhibition of PDI by infusion of PDI inhibitors impairs stable adhesion of neutrophils to the TNF-alpha-inflamed cremaster muscle venule wall in living mice. These findings suggest the potentially fundamental but poorly understood role for surface PDI in the regulation of beta2 integrin function in neutrophils. Therefore, our results provide the first evidence that inhibition of PDI may be a therapeutic target for the neutrophil-mediated vascular inflammation. Disclosures: No relevant conflicts of interest to declare.
Advanced vehicle control systems (AVCS) research for automated highway systems in California PATH

This paper describes research on advanced vehicle control systems (AVCS) for automated highway systems (AHS) in the California PATH (Partners for Advanced Transit and Highways) program. After a brief introduction of the PATH and a review of the history of AHS, research in PATH at both the system level and the vehicle level control is reviewed. The PATH hierarchical AHS architecture consists of network, link, coordination and regulation layers. The regulation layer is supported by AVCS which consists of vehicle longitudinal control and lateral control. >
Picking Olives and Building the State

The chapter describes how against the odds of spreading settlements and a paralyzed Oslo process, the reformist Palestinian Prime Minister Salam Fayyad undertook almost Herculean efforts to advance Palestinian state building. They were fully supported by the international community, including the UN, which certified that the Palestinian Authority was well positioned for the establishment of a state "at any point in the future." However, Palestinian state building ultimately turned into a “failed success,” and got drowned in the political vacuum of stalling negotiations.
Pattern Reconfigurable Printed Dipole Antenna Using Loaded Parasitic Elements

A printed dipole antenna is designed with two parasitic elements loaded by embedded resonators to provide reconfigurable patterns. The embedded resonators in the parasitic elements are loaded by varactor diodes, which change the phase and the transmission coefficient responses of the parasitic elements. This allows the parasitic elements to act as either a director, a reflector, or a neutral element. The proposed printed dipole antenna with two loaded parasitic elements acts as a printed Yagi-Uda antenna. Because the parasitic elements can act as either a director or a reflector, the directed gain can be increased, and the front-to-back ratio (FBR) may be improved up to 42 dB. It is also possible to achieve different target FBR if broadcasting is needed in two directions of the boresight. This pattern reshaping can be obtained as quickly as the diodes can change their capacitance. The antenna is designed to operate at 2.4 GHz, but this design approach can be applied to other frequency bands. The simulation and measurement results are in good agreement. © 2016 IEEE.
Strength of Cu-28 wt%Ag composite solidified under high magnetic field followed by cold drawing

Cu-Ag composite is one of the best conductors for high-field magnets. Increasing its strength is crucial for designing newer high-field magnets. Cu-28 wt%Ag samples were solidified with and without a 12-T high magnetic field (HMF), and then cold-drawn. We investigated the influence of HMF on microstructure, hardness and strength of Cu-Ag samples both before and after cold-drawing. The introduction of external HMF during solidification increased both the dendrite arm spacing and the dissolved Ag in Cu, and it reduced the spacing between both the Ag precipitates in proeutectic Cu and the eutectic lamellae. The transversal microstructure after cold-drawing inherited the network solidification structure, but at a refined scale. The Cu dendrite spacing in the 12-T HMF samples at all deformation strain was larger than that without HMF. HMF slightly increased the intensity of fiber texture of Cu, which strengthened proeutectic Cu at the level of 3.5 deformation strain. In samples deformed to strain of 3.5, refined Ag precipitation spacing, increased Ag solubility in Cu matrix, and refined eutectic lamellar spacing by 12-T HMF increased the strength by 5% in the sample compared with that without HMF.
Self-limited membranous nephropathy after intravitreal bevacizumab therapy for age-related macular degeneration.

Background: Monoclonal antibodies targeting vascular endothelial growth factor (VEGF), such as bevacizumab, are administered intravitreally for the treatment of wet or exudative age-related macular degeneration (ARMD). Systemic use of bevacizumab has been linked to a wide range of renal adverse effects including proteinuria and hypertension. Case Presentation: We present the case of a 77-year-old Caucasian male with a past medical history of hypertension, vitamin D deficiency and paroxysmal atrial fibrillation who presented to primary care clinic with a 2-week history of bilateral lower extremity edema, 2 months after completing four monthly intravitreal injections of bevacizumab for ARMD. Examination was remarkable for blood pressure of 187/91 mm Hg and severe bilateral lower extremity edema. Work up revealed unremarkable complete blood count (CBC), comprehensive metabolic panel (CMP), lipid panel, and echocardiography, except for 491 mg/dL albuminuria. Metoprolol and furosemide were added to hydrochlorothiazide and lisinopril. Work up by nephrology consult team five months later was notable for a urinalysis revealing 3 red blood cells/high power field (RBC/HPF), 24-hour urine protein of 8.6 g, and serum creatinine of 1.2 mg/dL. Viral hepatitis panel, total complement activity (CH50), C3, C4, anti-nuclear antibody (ANA), anti-neutrophil cytoplasmic antibody (ANCA), serum and urine protein electrophoresis were all unremarkable. Renal biopsy was consistent with membranous nephropathy. Age-appropriate cancer screening was negative. Random urine protein-to-creatinine ratio declined to 2 g/g and then to 0.56 g/g at 7 and 10 months follow up, respectively. Serum blood urea nitrogen (BUN) and creatinine remained normal throughout the course of illness and patient did not require any immunosuppressive treatment. Conclusions: The wide range of nephrotoxicity after systemic bevacizumab has been well documented. Our case describes a self-limited biopsy-proven membranous nephropathy after intravitreal bevacizumab injections.
North Atlantic Deep Water formation inhibits high Arctic contamination by continental perfluorooctane sulfonate discharges

Perfluorooctane sulfonate (PFOS) is an aliphatic fluorinated compound with eight carbon atoms that is extremely persistent in the environment and can adversely affect human and ecological health. The stability, low reactivity, and high water solubility of PFOS combined with the North American phaseout in production around the year 2000 make it a potentially useful new tracer for ocean circulation. Here we characterize processes affecting the lifetime and accumulation of PFOS in the North Atlantic Ocean and transport to sensitive Arctic regions by developing a 3-D simulation within the MITgcm. The model captures variability in measurements across biogeographical provinces (R2 = 0.90, p = 0.01). In 2015, the North Atlantic PFOS reservoir was equivalent to 60% of cumulative inputs from the North American and European continents (1400 Mg). Cumulative inputs to the Arctic accounted for 30% of continental discharges, while the remaining 10% was transported to the tropical Atlantic and other regions. PFOS concentrations declined rapidly after 2002 in the surface mixed layer (half-life: 1–2 years) but are still increasing below 1000 m depth. During peak production years (1980–2000), plumes of PFOS-enriched seawater were transported to the sub-Arctic in energetic surface ocean currents. However, Atlantic Meridional Overturning Circulation (AMOC) and deep ocean transport returned a substantial fraction of this northward transport (20%, 530 Mg) to southern latitudes and reduced cumulative inputs to the Arctic (730 Mg) by 70%. Weakened AMOC due to climate change is thus likely to increase the magnitude of persistent bioaccumulative pollutants entering the Arctic Ocean.
Depression in Girls During the Transition to Adolescence: Risks and Effective Treatment

Girls experience an increased risk for depression as they transition to adolescence, with rates of depression tripling for girls between the ages of 12 and 15. Further, while there is no gender dif...
Self-renewal and CSCs in vitro enrichment: Growth as floating spheres

Cancer stem cells (CSC) are a vital component to the progression and reoccurrence of cancers, making them a primary target of study for both fundamental understanding of cancer biology and the development of effective and targeted treatments. CSCs reside in a complex 3D microenvironment, and the 3D spheroids are an indispensable tool in tumor biology due to their 3D structure and replication of the tumor microenvironment. Within this chapter the methodology for CSC isolation, suspension culture in hanging drop model, and characterization assays for CSC are described. First, the methodology for identifying and isolating CSCs from patient tumors, ascites, or cancer cell lines is described through the use of FACS analysis. Next, a detailed description of 3D hanging drop model for generating CSC spheroids is provided, followed by maintenance and monitoring techniques for extended 3D culture. Analysis methods are described for the quantification of CSC spheroid proliferation and viability tracking, throughout culture by on-plate alamarBlue fluorescence. Additional viability assays are described utilizing confocal microscopy with Live/Dead Viability/Cytotoxicity Kit. The characterization of CSCs populations within spheroids is described through FACS analysis. Further, an immunohistochemistry procedure is described for cell-cell and cell-matrix interaction assessment. Finally, several notes and tips for successful experiments with 3D CSC spheroids on the hanging drop model are provided. These methods are not only applicable to CSCs within a variety of tumor cell types, for not only understanding the fundamental tumor biology, but also for drug screening and development of preclinical chemotherapeutic strategies.
A Gendered Model of Lifetime Experiences of Strain

Criminological literature has examined the potential for gendered pathways of offending, while also recognizing the gendered risk for victimization. General strain theory explicitly recognizes this gendered risk as strains that structure differences in these experiences for males and females. The current article tests the longitudinal risk for different sources of strain using a general strain model and gendered factors that shape differences between males and females. The results suggest that strains like childhood maltreatment, adolescent adversity, and adult intimate partner victimization as predictors of deviant behaviors can be explained within a general strain argument, but both similarities in the theoretical variables employed in the models and differences in the pathways between these experiences are evident across gender.
Hearing Loss after Cardiac Surgery in Infancy: An Unintended Consequence of Life-Saving Care

Objectives To investigate the prevalence of hearing loss after cardiac surgery in infancy, patient and operative factors associated with hearing loss, and the relationship of hearing loss to neurodevelopmental outcomes. Study design Audiologic and neurodevelopmental evaluations were conducted on 348 children who underwent repair of congenital heart disease at the Children's Hospital of Philadelphia as part of a prospective study evaluating neurodevelopmental outcomes at 4 years of age. A prevalence estimate was calculated based on presence and type of hearing loss. Potential risk factors and the impact of hearing loss on neurodevelopmental outcomes were evaluated. Results The prevalence of hearing loss was 21.6% (95% CI, 17.2-25.9). The prevalence of conductive hearing loss, sensorineural hearing loss, and indeterminate hearing loss were 12.4% (95% CI, 8.8-16.0), 6.9% (95% CI, 4.1-9.7), and 2.3% (95% CI, 0.6-4.0), respectively. Only 18 of 348 subjects (5.2%) had screened positive for hearing loss before this study and 10 used a hearing aid. After adjusting for patient and operative covariates, younger gestational age, longer postoperative duration of stay, and a confirmed genetic anomaly were associated with hearing loss (all P Conclusions These findings suggest that the prevalence of hearing loss in preschool children after heart surgery in infancy may be 20-fold higher than in the 1% prevalence seen in the general population. Younger gestational age, presence of a genetic anomaly, and longer postoperative duration of stay were associated with hearing loss. Hearing loss was associated with worse neurodevelopmental outcomes.
Issues of impairment: descriptions and discussions

This chapter draws on the interactional model of disability (Danermark and Gellerstedt 2004; Gustavsson 2004; Shakespeare 2014), but purposely focuses on the factors that impact on the individual, and more specifically on impairment, namely the biological, neurological and psychological levels of disability. Whilst this could arguably be considered a reductionist, medical, “individual essentialism” (Gustavsson 2004) approach; it is not my intention to endorse a strict medical model, but to simply concentrate on one of the many analytical levels of the “necessarily laminated system” (Bhaskar and Danermark 2006, p. 280) that represent the complex reality of disability.
Working Under the Tent: Confidentiality and Restricted Information Disclosure

The year 2016 ended with announcement of mergers and acquisitions (M&A) deals worth $3.2 trillion. Multiple studies put the failure rate of M&A transactions at 70–90%, which is remarkably high. This failure can be in the form of falling short of the initial financial expectations of the combined entity, not producing benefits in terms of shareholder value, etc. The divestiture, which is one of the M&A transactions, of a company or business unit involves the change in structure of the company including restructuring of the workforce, information technology (IT) systems, and potentially the business strategy. Now consider a divestiture in terms of distinct personalities and behaviors of thousands of employees spread across multiple countries with different laws and regulations. When an M&A deal is viewed in light of these complexities, the failure rate appears to be not so surprising.
Particulate-bound pigment of Serratia marcescens (Chromobacterium prodigiosum).

Le broyage mecanique deSerratia marcescens pigmentes produit un liquide rouge clair. Apres centrifugation a 105 000×g, le pigment se sedimente sous forme d'un agglomerat rouge et la phase liquide reste incolore. La courbe du materiel de l'agglomerat remis en suspension montre a l'ultracentrifuge un seul sommet coincidant avec le pigment.S. marcescens non pigmentes ne produisent pas d'agglomerat apres broyage et centrifugation et donnent une courbe differente a l'ultracentrifuge.
The Role of Cyclic Wear (Fretting) in Fatigue Crack Nucleation in Steels

ABSTRACT Fretting and fretting corrosion result in significant amounts of material loss between the surfaces of faying parts. Additionally, these phenomena often result in decreased fatigue resistance of metals and alloys. Fretting and fretting fatigue experiments have been performed on a medium carbon steel (4130) quenched and tempered (tempered martensite) as functions of relative slip amplitude, normal contact pressure, and cyclic load. Results obtained indicate that the sliding rate of moving parts is not uniform, with a “stick-slip” process occurring at the interface. The maximum velocity of slip was shown to coincide with an observed maximum in temperature change at the interfaces. Subsequent light and scanning electron microscopy showed the fretting action to produce numerous layers of flake-like particles which were easily detached from the fretted surfaces. These flakes often show considerable plastic deformation and also appear to crack into smaller flakes as fretting continues. Additionally, the near surface region of the fretted surface shows extensive plastic deformation. Non-surface connected cracks are observed parallel to and below the fretted surfaces. These cracks eventually deviate to follow martensite platelets and either propagate to the surface to create the flake morphology or into the specimen to initiate fatigue crack propagation
Science, values, and common ground

In this paper, I argue that there may be common ground shared by animal science and its critics insofar as animal scientists seek improvement in their field in four areas: the quality of their products, the quality of life for those who make their livelihood in food production, the fair treatment of human workers, and the humane treatment of animals. I also propose that there are fundamental differences between improvement motivated by profit and improvement motivated by ethical values. Positive moral change is sometimes revolutionary, although it is often a matter of promoting positive incremental changes and keeping one's attention on the effects of actions and attitudes. In conclusion, I suggest that in animal agriculture, positive change can be brought about by getting closer to the objects of scientific research, including nonhuman animals, by paying more attention to their welfare.
Assessing statistical literacy and statistical reasoning: The reali instrument

Statistical literacy and statistical reasoning are important learning goals that instructors aim to develop in statistics students. However, there is a lack of clarity regarding the relationship among these learning goals and to what extent they overlap. The REasoning and Literacy Instrument (REALI) was designed to concurrently measure statistical literacy and reasoning. This paper reports the development process of the REALI assessment, which included test blueprint, expert review, item categorization, pilot and field testing, and data analysis to identify what measurement model best represents the constructs of statistical literacy and reasoning given the criteria of fit and parsimony. The results suggested that statistical literacy and reasoning can be measured effectively by the REALI assessment with high score precision. First published November 2018 at Statistics Education Research Journal Archives
Distributed constructionism

This paper introduces the concept of distributed constructionism, building on previous research on constructionism and on distributed cognition. It focuses particularly on the use of computer networks to support students working together on design and construction activities, and it argues that these types of activities are particularly effective in supporting the development of knowledge-building communities. The paper describes three main categories of distributed constructionist activities: discussing constructions, sharing constructions, and collaborating on constructions. In each category, it describes ongoing research projects at the MIT Media Lab and discusses how these projects support new ways of thinking and learning.
WCK 5222 (Cefepime/Zidebactam) Pharmacodynamic Target Analysis against Metallo-β-lactamase producing Enterobacteriaceae in the Neutropenic Mouse Pneumonia Model.

WCK 5222 is a combination of cefepime and the novel β-lactam enhancer (BLE) zidebactam. Zidebactam has a dual mechanism of action involving high-affinity penicillin binding protein (PBP) 2 binding as well as inhibition of Ambler class A, and C, enzymes. In the current study, we evaluated the effect of zidebactam on the cefepime pharmacodynamic target time above MIC (T>MIC) exposure required for efficacy against a diverse group of carbapenem-resistant Enterobacteriaceae (CRE) secondary to MBL-production. Plasma and ELF pharmacokinetic (PK) studies were performed for both cefepime (6.25, 25, and 100 mg/kg) and zidebactam (3.125, 12.5, and 50 mg/kg) after subcutaneous administration to mice. Only total drug was considered as protein binding is MIC. The results were modelled to evaluate the relationship between cefepime T>MIC, when zidebactam was co-administered, and therapeutic effect. The results revealed a strong association between T>MIC and effect (R2 0.82). Net stasis in organism burden occurred at cefepime T>MIC exposures of only 18%. A 1-log kill endpoint was demonstrated for the group of organisms at approximately 31% T>MIC. These target exposures for stasis and 1-log kill are much lower than previously observed cephalosporin monotherapy PK/PD targets.
Daily red wine vinegar ingestion for eight weeks improves glucose homeostasis and affects the metabolome but does not reduce adiposity in adults.

Some studies have reported that vinegar ingestion at mealtime attenuates postprandial glycemia in healthy adults and individuals with type 2 diabetes. Emerging data suggest that chronic vinegar ingestion impacts fat metabolism and reduces adiposity, although no study has yet corroborated the events of vinegar supplementation metabolically through a metabolomics approach. To examine the impact of daily vinegar ingestion on glucose homeostasis, adiposity, and the metabolome, an 8-week, randomized controlled trial design was implemented utilizing two parallel treatment arms: daily red wine vinegar ingestion and a control treatment. Participants were 45 healthy adults at increased risk for metabolic complications as determined by high waist circumferences. Measurements and blood samples were collected pre- and post-intervention. Central adiposity and visceral fat were assessed by waist circumference and dual-energy X-ray absorptiometry, respectively. Plasma metabolites were analyzed using gas chromatography-mass spectrometry (MS) and liquid chromatography-MS/MS. Analysis showed significant reductions in fasting glucose (p = 0.003) and insulin (p 2) between groups. Metabolic pathway analysis revealed significant alterations in tryptophan metabolism. Although daily red wine vinegar ingestion for 8 weeks induced significant improvements in glucose homeostasis, our results indicate that daily red wine vinegar ingestion for 8 weeks is not associated with reductions in adiposity. This is the first study to investigate the effects of daily red wine vinegar supplementation using a metabolomics approach. Our results provide strong rationales for larger prospective studies to further clarify associations among obesity, chronic diseases, and functional foods such as vinegar using metabolomics.
ECON: Modeling the network to improve application performance

Given the growing significance of network performance, it is crucial to examine how to make the most of available network options and protocols. We propose ECON, a model that predicts performance of applications under different protocols and network conditions to scalably make better network choices. ECON is built on an analytical framework to predict TCP performance, and uses the TCP model as a building block for predicting application performance. ECON infers a relationship between loss and congestion using empirical data that drives an online model to predict TCP performance. ECON then builds on the TCP model to predict latency and HTTP performance. Across four wired and one wireless network, our model outperforms seven alternative TCP models. We demonstrate how ECON (i) can be used by a Web server application to choose between HTTP/1.1 and HTTP/2 for a given Web page and network condition, and (ii) can be used by a video application to choose the optimal bitrate that maximizes video quality without rebuffering.
Review on modeling of photovoltaic power generation systems

In recent years, photovoltaic (PV) power generation has developed rapidly at China and abroad. PV power generation is on the trend from auxiliary power supply to main power supply even leading power supply. Due to the fluctuation and intermittent characteristics of PV power generation, and zero inertia, the integration of large-scale grid-connected PV power generation may have a negative impact on the stability of the power system. Modeling grid-connected PV power generation systems is the key factor to investigate the influence between it and other parts of power system. Modeling of PV is also a hot issue that has been studied continuously for many years around the world. GE, WECC, CIGRE, CEPRI and so on have attached great importance to this issue and have published many research results. The existing research at China and abroad is reviewed in this paper, the existing problems are analyzed, and suggestions for future research are given.
Machine Learning Can Accurately Predict Pre-Admission Baseline Hemoglobin and Creatinine in Intensive Care Patients

Patients admitted to the intensive care unit frequently have anemia and impaired renal function, but often lack historical blood results to contextualize the acuteness of these findings. Using data available within two hours of ICU admission, we developed machine learning models that accurately (AUC 0.86–0.89) classify an individual patient’s baseline hemoglobin and creatinine levels. Compared to assuming the baseline to be the same as the admission lab value, machine learning performed significantly better at classifying acute kidney injury regardless of initial creatinine value, and significantly better at predicting baseline hemoglobin value in patients with admission hemoglobin of <10 g/dl.
A Sparse Latent Class Model for Cognitive Diagnosis

Cognitive diagnostic models (CDMs) are latent variable models developed to infer latent skills, knowledge, or personalities that underlie responses to educational, psychological, and social science tests and measures. Recent research focused on theory and methods for using sparse latent class models (SLCMs) in an exploratory fashion to infer the latent processes and structure underlying responses. We report new theoretical results about sufficient conditions for generic identifiability of SLCM parameters. An important contribution for practice is that our new generic identifiability conditions are more likely to be satisfied in empirical applications than existing conditions that ensure strict identifiability. Learning the underlying latent structure can be formulated as a variable selection problem. We develop a new Bayesian variable selection algorithm that explicitly enforces generic identifiability conditions and monotonicity of item response functions to ensure valid posterior inference. We present Monte Carlo simulation results to support accurate inferences and discuss the implications of our findings for future SLCM research and educational testing.
Automated and Manual Grading of Web-Based Assignments

Grading web-based assignments poses many unique challenges when compared with other types of programming assignments. For introductory courses, grading involves not just validation of source code, but also performing some level of functional testing through a browser environment, where one clicks on content, and validates the browser state. In upper level courses, assignments increasingly use several different services, such as a web server and database, running concurrently, each potentially exposing ports for user access. Finally, for some assignments where students are encouraged to be creative, an instructor must then be able to view and interact with the running code, which has historically meant downloading, setting it up on their local machine, and running it -- which can prove burdensome. In this work, we present a system that can perform the task of automated grading, create a web-accessible environment on the server for the instructor to manually grade the assignment, and that can scale to handle many concurrent instances of both. To evaluate the effectiveness of our system, we will demonstrate its usage within the context of several assignments ranging over several different levels and courses of our Information Technology curriculum.
Strings, symmetric products, TT¯ deformations and Hecke operators

Abstract We derive a formula for the torus partition sum of the symmetric product of T T ¯ deformed CFT's, using previous work on long strings in (deformed) A d S 3 , and universality. The result is given by an integral transform of the partition function for the block of the symmetric product, summed over its Hecke transforms, and is manifestly modular invariant. The spectrum is interpretable as a gas of multiply wound long strings with a particular orientation.
Quantifying the line-of-sight halo contribution to the dark matter convergence power spectrum from strong gravitational lenses

Galaxy-galaxy strong gravitational lenses have become a popular probe of dark matter (DM) by providing a window into structure formation on the smallest scales. In particular, the convergence power spectrum of subhalos within lensing galaxies has been suggested as a promising observable to study DM. However, the distances involved in strong-lensing systems are vast, and we expect the relevant volume to contain line-of-sight (LOS) halos that are not associated with the main lens. We develop a formalism to calculate the effect of LOS halos as an effective convergence power spectrum. The multilens plane equation couples the angular deflections of consecutive lens planes, but by assuming that the perturbations due to the LOS halos are small, we show that they can be projected onto the main-lens plane as effective subhalos. We test our formalism by simulating lensing systems using the full multiplane lens equation and find excellent agreement. We show how the relative contribution of LOS halos and subhalos depends on the source and lens redshift, as well as the assumed halo and subhalo mass functions. For a fiducial system with fraction of DM halo mass in substructure ${f}_{\mathrm{sub}}=0.4%$ for subhalo masses $[{10}^{5}--{10}^{8}]{\mathrm{M}}_{\ensuremath{\bigodot}}$, the interloper contribution to the power spectrum is at least several times greater than that of subhalos for source redshifts ${z}_{s}\ensuremath{\gtrsim}0.5$. Furthermore, it is likely that for the SLACS and BELLS lenses the interloper contribution dominates: ${f}_{\mathrm{sub}}\ensuremath{\gtrsim}2%$ (4%) is needed for subhalos to dominate in SLACS (BELLS), which is higher than current upper bounds on ${f}_{\mathrm{sub}}$ for our mass range. Since the halo mass function is better understood from first principles, the dominance of interlopers in galaxy-galaxy lenses with high-quality imaging can be seen as a significant advantage when translating this observable into a constraint on DM.
Assessment of Real-World Use of Behavioral Health Mobile Applications by a Novel Stickiness Metric.

This cross-sectional study uses a novel “stickiness” measure to evaluate which mobile applications for smoking cessation, meditation, and other behavioral health areas are associated with long-term engagement.
Donation after circulatory death heart transplant

Dr. O.P. Yadava, CEO and Chief Cardiac Surgeon, National Heart Institute, New Delhi, India, and Editor-in-Chief, Indian Journal of Thoracic and Cardiovascular Surgery, in a conversation with Dr. Catherine Dushyant Sudarshan, discusses the state of donation after circulatory death for cardiac transplant and how it can address the donor shortages.
The size-mobility relationship of ions, aerosols, and other charged particle matter.

Abstract Electrical Mobility is arguably the property upon which some of the most successful classification criteria are based for aerosol particles and ions in the gas phase. Once the value of mobility is empirically obtained, it can be related to a geometrical descriptor of the charged entity through a size-mobility relationship. Given the multiscale range of sizes in the aerosol field, approaches that can provide accurate transformations from mobility to size are not straightforward, and many times rely on experimentally derived parameters. The most well-known size-mobility analytical expression covering the whole Knudsen range for spherical particles is the semi-empirical Stokes-Millikan correlation. This expression matches Stokes' drag friction coefficient in the continuum regime and the friction factor for a predominantly diffuse reemission of the gas molecule in the free molecular regime, as theorized by Epstein, with empirical slip coefficients chosen to agree with Millikan's oil drop experiments. Despite its success, the Stokes-Millikan correlation has its shortcomings. For example, it needs to be modified to predict the mobility of non-spherical entities and needs correction terms when potential interactions or reduced mass effects are non-negligible. The Stokes-Millikan asymptotic behavior also fails to predict the gradual transition from diffuse to specular reemission behavior that is observed for increasingly smaller ions within the free molecular regime. Here we make an attempt at providing a comprehensive account of the existing mass-mobility relations in the continuum, transition and free molecular regimes for both spherical and non-spherical particles. Epstein's diffuse interaction is critically explored experimentally and numerically for different gases in the free molecular regime with the observation that, as the size of the particle increases, a progression from specular to diffuse reemission occurs for all gases studied. The rate at which this variation happens seems to differ from gas to gas and to be related to the conditions for which diffuse reemission effects stem from a combination of scattering and potential interactions.
Abstract 16391: Systemic Ventricular Dysfunction and Long Term Outcomes in Patients With D-transposition of the Great Arteries (D-TGA), Atrial Switch, and Systemic Right Ventricle Physiology

Introduction: Patients with D-TGA palliated with atrial switch operations have the morphologic right ventricle in the systemic position. There is increased risk of atrial arrhythmias and systemic r...
Development of an AASHTO Guide Specification for UHPC

The widespread, growing interest in the United States in using ultra-high performance concrete (UHPC) in engineered structures is being hindered by a lack of structural design guidance relevant to this class of materials. The material characteristics that form the foundational inputs for existing reinforced concrete design specifications do not represent the behaviors that can be attained with UHPC; therefore, using existing design guidance results in inefficient, overly costly structures. The U.S. Federal Highway Administration has embarked on an effort to develop the needed design guidance for bridges. This document, which will be in the form of a guide specification and will supplement the AASHTO LRFD Bridge Design Specifications, is being coordinated with the relevant subcommittee of the AASHTO Committee on Bridges and Structures. The guide specification will define UHPC, present threshold mechanical and durability properties, define material models, and provide design guidance for flexure, shear, and other critical performance metrics. Both prestressed concrete and mild steel reinforced concrete elements will be covered. This paper discusses the framework for the guide specification and provides insight into key aspects that have been investigated and drafted to date.
Pharmacotherapy of attention deficit/hyperactivity disorder in individuals with autism spectrum disorder: A systematic review of the literature.

Aim:To assess the empirical evidence for the treatment of attention deficit/hyperactivity disorder (ADHD) in populations with autism spectrum disorder (ASD).Methods:A systemic PubMed, PsychINFO, Em...
Assessment of model parameters in MFiX particle-in-cell approach

Abstract The limitations in numerical treatment of solids-phase in conventional methods like Discrete Element Model and Two-Fluid Model have facilitated the development of alternative techniques such as Particle-In-Cell (PIC). However, a number of parameters are involved in PIC due to its empiricism. In this work, global sensitivity analysis of PIC model parameters is performed under three distinct operating regimes common in chemical engineering applications, viz. settling bed, bubbling fluidized bed and circulating fluidized bed. Simulations were performed using the PIC method in Multiphase Flow with Interphase eXchanges (MFiX) developed by National Energy Technology Laboratory (NETL). A non-intrusive uncertainty quantication (UQ) based approach is applied using Nodeworks to first construct an adequate surrogate model and then identify the most influential parameters in each case. This knowledge will aid in developing an effective design of experiments and determine optimal parameters through techniques such as deterministic or statistical calibration.