cssi/SciSciGPT-SciSciNet huggingface dataset:
Metals leaching from common residential and commercial roofing materials across four years of weathering and implications for environmental loading.

Urban stormwater is a major source of chemical pollution to receiving waters. Anthropogenic materials in the built environment can be an important source of chemicals to stormwater runoff. Roofing materials can leach significant amounts of metals, which vary over the life of the roof. We report concentrations of three metals (As, Cu, Zn) leaching into runoff from experimental panels of 14 roofing materials over 4.5 years of weathering. Ten roofing materials leached metals. Several leached >10 ppb during one or more study periods. The most common correlate with metal concentration was panel age, followed by precipitation amount. Extrapolating from these observations, we estimated the loading of metals from each roofing material during the first 10 years following installation. Eight materials were predicted to leach metals above background at the end of the 10 years. In combination with information on the prevalence of different roofing materials in the Puget Sound region of the Pacific Northwest, we estimated the relative amount of metals contributed from roofing materials in this basin. Most arsenic and copper was estimated to be contributed by residential roofing; nearly all arsenic from wood shakes manufactured with copper chromated arsenic, and copper contributed mainly from treated wood shakes followed by copper granule-containing asphalt shingles. Most zinc was estimated to be contributed by commercial roofs, including Zincalume and painted metal roofs. Overall our data shows that roofing materials can be an important long-term source of As, Cu, and Zn to stormwater runoff. Compared with atmospheric deposition, roof materials were a significant source, particularly of As and Cu. To get a complete picture of metals sourced from buildings, there is a need to study whole roof systems, including gutters, downspouts, and HVAC systems, as well as metals contributed from homeowner-applied treatments to their roofs.
Patterns of Axillary Management in Stages 2 and 3 Hormone Receptor-Positive Breast Cancer by Initial Treatment Approach

Data regarding axillary management after neoadjuvant endocrine therapy (NET) are lacking. This study examined axillary management of hormone receptor-positive (HR+) patients based on initial treatment with NET, neoadjuvant chemotherapy (NAC), or upfront surgery. Patients with stage 2 or 3 HR+/HER2− breast cancer treated between 2012 and 2015 were identified in the National Cancer Database. The study examined axillary surgery [sentinel lymph node biopsy (SLNB), SLNB followed by axillary lymph node dissection (ALND), or upfront ALND] by initial treatment stratified by cN0/N1 using pairwise comparisons and multivariable logistic regression. Of 92,204 eligible patients, 2138 (2.3%) received NET, 11,014 (12%) received NAC, and 79,052 (85.7%) received surgery. Among 60,998 cN0 patients, attempted SLNB was more likely for surgery patients (86.2%, 47,159/54,684) and NET patients (85.8%, 1342/1564) than for NAC patients (79.9%, 3793/4750) (both p < 0.001). Among 31,206 cN1 patients, attempted SLNB was more likely for the surgery patients (46.0%, 11,201/24,368) than for the NET patients (41.8%, 240/574; p = 0.05) or the NAC patients (39.8%, 2491/6264; p < 0.0001). The differences between surgery and NET did not persist in the adjusted analyses. Among both the cN0 patients (n = 13,856) and the cN1 patients (n = 8688) with pN1 disease shown by SLNB, the NET patients were treated with ALND less frequently than those receiving NAC or surgery (p < 0.0001 for all comparisons). In the multivariate analysis, for the patients with pN1 disease shown by SLNB, NET use was associated with increased odds of undergoing SLNB alone [cN0 patients: odds ratio (OR), 1.31, 95% confidence interval (CI), 1.04–1.64; cN1 patients: OR 1.45; 95% CI 1.00–2.10]. For stages 2 and 3 HR+/HER2− patients, SLNB use after NET was similar to that for upfront surgery. Among those with pN1 disease, the NET patients were less likely to undergo ALND. Additional outcomes data are needed to guide axillary management after NET.
Buoyancy-adjusting Profiling Floats for Exploration of Heat Transport, Melt Rates, and Mixing in the Ocean Cavities Under Floating Ice Shelves

Recent successes using EM-APEX velocity profiling floats under sea ice (in an “ice contacting” mode which allows floats to measure ice draft to an accuracy a few centimeters after applying an atmospheric pressure correction) have inspired an innovative study of the seawater cavity under a floating ice shelf. We report here on a recent (January 2018 through March 2019) experiment using acoustically-tracked EM-APEX along with Seagliders to survey the distribution of temperature, salinity, shear, and melt rates in the Dotson Ice Shelf cavity. The 4 floats released in front of the ice shelf were carried by the warm inflow nearly to the grounding line 80 km back from the calving face, and one even furtherthrough a sub-glacial connection into the adjoining Crosson Ice Shelf cavity.
Gold nanoclusters cause selective light-driven biochemical catalysis in living nano-biohybrid organisms

Living nano-biohybrid organisms or nanorgs combine the specificity and well-designed surface chemistry of an enzyme catalyst site, with the strong light absorption and efficient charge injection (for biocatalytic reaction) from inorganic materials. Previous efforts in harvesting sunlight for renewable and sustainable photochemical conversion of inexpensive feedstocks to biochemicals using nanorgs focused on the design of semiconductor nanoparticles or quantum dots (QDs). However, metal nanoparticles and nanoclusters (NCs), such as gold (Au), offer strong light absorption properties and biocompatibility for potential application in living nanorgs. Here we show that optimized, sub-1 nanometer Au NCs-nanorgs can carry out selective biochemical catalysis with high turnover number (108 mol mol−1 of cells) and turnover frequency (>2 × 107 h−1). While the differences of size, light absorption, and electrochemical properties between these NCs (with 18, 22, and 25 atoms) are small, large differences in their light-activated properties dictate that 22 atom Au NCs are best suited for forming living nanorgs to drive photocatalytic ammonia production from air. Based on our experiments, these Au22 NC-nanorgs demonstrate 29.3% quantum efficiency of converting absorbed photons to the desired chemical, and 12.9% efficiency of photon-to-fuel conversion based on energy input–output. Further, by comparing the light-driven ammonia production yield between strains producing Mo–Fe nitrogenase with and without histidine tags, we demonstrate that preferential coupling of Au NCs to the nitrogenase through Au–histidine interactions is crucial for effective electron transfer and subsequent product generation. Together, these results provide the design rules for forming Au NCs-nanorgs and can have important implications for carrying out light-driven biochemical catalysis for renewable solar fuel generation.
Microaggressions, Marginalization, and Stress: Issues of Identity, Place, and Home for Minority Faculty in Academia

Social relations between racial minority faculty and dominant group (white) faculty are chronicled by racial and ethnic minority faculty through their narrative accounts in the research literature of microaggressions they experience in academia. Treating these narrative accounts as archival data can serve as a research strategy for understanding the presence and voice of racial and ethnic minority faculty in colleges and universities. I examine the experiences of racial and ethnic minority faculty found in the research literature. My examination of their experiences frames the context for discussing the social relations between minority faculty and dominant group faculty. I argue that an examination of the social relations of racial and ethnic minority faculty with dominant group faculty serves as a window for observing institutional practices that situate the presence of racial and ethnic minority faculty in academia and which, as a result, produce social and psychological stress for minority faculty regarding questions of identity, place, and home in the academic culture.
Transmission Hosting Capacity of Distributed Energy Resources

Distributed energy resources (DERs) are transforming the operation and planning of both distribution and transmission grids. Stability impacts from the increasing generation contribution of DERs have been widely recognized in distribution systems and are emerging in transmission systems. There is a need for the development of transmission hosting capacity studies of DERs so utilities will be able to predict and prevent instabilities, reductions in reliability on the electrical grid, and create planning methodologies that enable the continued growth of DERs. This paper evaluates the impact of different modeling considerations for assessing hosting capacity of DERs in transmission systems through analysis on a 2,000-bus synthetic grid test system. The modeling considerations include transient and steady state contingencies, use of dynamic load and DER models with voltage support control, dynamic load composition, and seasonal and loading scenarios. The results demonstrate that transient stability evaluations are more limiting than steady state analysis, the use of voltage support control in DERs can increase hosting capacity in the system, and large variations in hosting capacity can be found when assessing between seasonal variations. From comparing system factors the amount of wind generation in the system was a critical factor for hosting capacity in this study.
The geochemistry of gold assayers’ ingots from the SS Central America shipwreck: a geoarchaeological window into mid-1800s California assaying

The assayers’ ingots recovered in 2014 from the SS Central America contain geochemical signatures and anomalies which convey information about the culture of miners and assayers in the late 1850s. A significant number of ingots (21%) contain elevated copper and zinc in the same ratio as a common brass alloy of the period, suggesting that adulteration of placer gold dust was a common issue. The ingots with the brass-like signature also have a gold fineness much lower than measured for typical California placer gold. Trace elements like palladium in uniform concentrations in all Kellogg & Humbert ingots suggest the use of quality high-temperature tools, while lead and tin in all ingots suggest specific contamination and industrial hygiene issues common to the whole industry. Other trace constituents such as arsenic, antimony and bismuth are likely to have originated from dense minerals associated with placer gold, or from the natural placer gold alloy itself. Comparison of modern analysis of ingots vs. assay values stamped on the ingots themselves suggests some firms like Kellogg & Humbert did superior assay work, while others like the San Francisco office of Justh & Hunter probably had issues with quality control. The variations in assay ingot alloy chemistry provide a window into this important period in American history.
Ethical Publishing of Health Advice Online: Approaching Ethical Decision-Making through the Army-Baylor 7-Step Model Modified for Organizational Decision-Making

Following the creation of the internet in the late 1980s, the ease and access to personal computers has led to a global shift in how people gather and process information. In the past decade we hav...
Robust newsvendor problems with compound Poisson demands

We consider the robust newsvendor problem where the demand follows a compound Poisson distribution, but its distribution is only partly known. This assumption means that customers arrive according to a Poisson process with a given intensity, while the size of customer demand is another random variable. Yet, the newsvendor only knows the expectation and variance of the demand sizes. Given limited information, a plausible approach, put forth in prior work, is to evaluate the moments of the aggregate demand (from all customers) and then determine the respective order quantity. Instead, this paper suggests to make the best use of all the information contained in the first few moments of demand sizes as well as the structural properties of a compound demand distribution to compute a better ordering quantity. To achieve this goal, we propose a new decision model employing Panjer’s recursion as constraints. The attendant optimization problem is then solved via convex relaxation using McCormick envelopes. Numerical results confirm that the newsvendor can gain a significant increase in expected profit using the new modeling approach to make his/her ordering decision.
Auditors’ Customer Relationship Management Activities and Managers’ Cooperation with Auditor Evidence Requests

Auditors execute customer relationship management activities (hereafter CRM), such as minimizing disruptions and communicating effectively, to maintain or increase customer satisfaction of client managers. These activities are typically linked to auditors’ commercial objectives. However, using Social Exchange Theory, we link CRM to improvements in the audit process. In an experiment, we predict and find that delivering higher quality CRM increases managers’ cooperation with auditor evidence requests. Compared to managers experiencing lower quality CRM, managers experiencing higher quality CRM assign higher priority to auditor evidence requests, work harder to gather audit-relevant information, are more forthcoming with information, and convey an openness to future rounds of negotiation. Importantly, managers experiencing higher quality CRM are even more forthcoming with information that contradicts their preferred accounting position and may not be readily discoverable by auditors. These findings add to our understanding of the complex relationship between auditors and their clients, suggesting a positive influence of CRM on audit processes, which should be considered by those interested in understanding and regulating auditor-client relationships.
Noise correlations for faster and more robust learning

Distributed population codes are ubiquitous in the brain and pose a challenge to downstream neurons that must learn an appropriate readout. Here we explore the possibility that this learning problem is simplified through inductive biases implemented by stimulus-independent noise correlations that constrain learning to task-relevant dimensions. We test this idea in a set of neural networks that learn to perform a perceptual discrimination task. Correlations among similarly tuned units were manipulated independently of overall population signal-to-noise ratio in order to test how the format of stored information affects learning. Higher noise correlations among similarly tuned units led to faster and more robust learning, favoring homogenous weights assigned to neurons within a functionally similar pool, and could emerge through Hebbian learning. When multiple discriminations were learned simultaneously, noise correlations across relevant feature dimensions sped learning whereas those across irrelevant feature dimensions slowed it. Our results complement existing theory on noise correlations by demonstrating that when such correlations are produced without significant degradation of the signal-to-noise ratio, they can improve the speed of readout learning by constraining it to appropriate dimensions. Significance statement: Positive noise correlations between similarly tuned neurons theoretically reduce the representational capacity of the brain, yet they are commonly observed, emerge dynamically in complex tasks, and persist even in well-trained animals. Here we show that such correlations, when embedded in a neural population with a fixed signal to noise ratio, can improve the speed and robustness with which an appropriate readout is learned. In a simple discrimination task such correlations can emerge naturally through Hebbian learning. In more complex tasks that require multiple discriminations, correlations between neurons that similarly encode the task-relevant feature improve learning by constraining it to the appropriate task dimension.
Linked Data for Cultural Heritage

Linked data is a way of structuring and publishing data in a way that makes it more useful through semantic queries. Editor Ed Jones, in his introduction to Linked Data for Cultural Heritage, state...
Advancing the DFC Semantic Technology Platform via HIVE Innovation

The DataNet Federation Consortium (DFC) is developing data grids for multidisciplinary research. As the DFC grid grows in size and number of disciplines, it becomes critical to address metadata management and findability challenges. The HIVE project is being integrated into the iRODS in the DFC architecture to provide a scaleable linked open data approach to scientific data sharing.
The Regulation of Proopiomelanocortin Gene Expression by Estrogen in the Rat Hypothalamus

Estrogen is known to the decrease the level of β-endorphin, a pro- opiomelanocortin (POMC) derived peptide, in the rat hypothalamus. We have used a POMC cDNA probe to measure the levels of POMC mRNA in the arcuate region of the brain in ovariectomized female rats with and without estrogen replacement. Our results show that estrogen causes a time dependent decrease in POMC mRNA of approximately 40% in rats ovariectomized for 2 wk. Preliminary studies using a nuclear transcription system have indicated that estrogen may decrease POMC mRNA levels by having an inhibitory effect on transcription of the POMC gene. It is not clear from these results, however, whether estrogen is acting directly on POMC neurons, or whether it is producing it inhibitory effect through an interneuron system.
Predicting Young Adult Degree Attainment by Late Adolescent Marijuana Use

Abstract Purpose The purpose of this study was to assess whether infrequent and frequent marijuana use at age 19/20 years predicts receipt of educational degrees by the mid-20s, independent of confounding age 18 adolescent risk factors. Methods Data were from the Monitoring the Future study, an annual nationally representative survey of high school seniors followed into adulthood. Thirteen cohorts (1990–2002) of high school seniors were followed longitudinally to their mid-20s (n = 4,925; 54% female). We used logistic regression and propensity score matching with successive inclusion of age 18 risk factors and substance use to compare age 19/20 frequent marijuana users (six or more occasions in past 30 days) to nonusers, frequent users to infrequent users (1–6 occasions), and infrequent users to nonusers on their likelihood of degree attainment by the mid-20s. Results Frequent marijuana users were less likely than infrequent users and nonusers to earn bachelor's degrees, even after controlling for a host of age 18 risk factors (e.g., family socioeconomic background, academic performance, educational expectations, truancy). However, these differences were reduced in magnitude to statistical nonsignificance when we controlled for age 18 substance use. Across analyses, the proportion reaching this educational milestone did not differ significantly between infrequent users and nonusers. Conclusions Results support a growing body of work suggesting that frequent marijuana use predicts a lower likelihood of postsecondary educational attainment, and this difference may originate during secondary school.
CORRELATION OF ACCIDENT AND LABORATORY IMPACTS TO ENERGY-ABSORBING STEERING ASSEMBLIES

DATA ARE PRESENTED FOR 19 FRONTAL-FORCE COLLISIONS INVOLVING VEHICLES WITH COLLAPSIBLE STEERING COLUMNS WITH COLLISION SEVERING RATING FROM MINOR TO VERY SEVERE (1-7) AND AN INJURY SEVERITY INDEX FROM MINOR TO FATAL. INJURY RESULTS ARE COMPARED TO LABORATORY EXPERIMENTS IN WHICH A FORCE OF 1800 LB DISTRIBUTED OVER THE RIM AND HUB WAS MEASURED FOR A FAIRLY STIFF WHEEL AND COLLAPSIBLE COLUMN COMBINATION. WHEN THE STEERING WHEEL DID NOT DEFORM EXCESSIVELY AND THE FORCE REACHED THE 1800 LB LEVEL AS EVIDENCED BY COLUMN COLLAPSE, THERE WERE NO SERIOUS THORACIC INJURIES. GROSS DEFORMATION OF THE STEERING WHEEL WITH EXPOSED SHARP SPOKE ENDS OR SMALL DIAMETER HUB RESULTED IN SERIOUS ABDOMINAL AND THORACIC INJURIES. TWO CASES OF HOOD INTRUSION ARE PRESENTED, EACH OF WHICH RESULTED IN FATALITIES. /AUTHOR/
Investigation of Daily Flow Forecasting Models

Two types of models for forecasting daily flows from a basin are investigated. These model types are a segmented model whose components are multi-input linear models of the basin between gaging stations, and an unsegmented or fully lumped stochastic basin model of the ARMA (p,q) family. Three approaches to segmented model construction are investigated. The results show that a constrained linear systems estimation method gave models which produced forecasts with a smaller bias than the ordinary least-squares method. The addition of an error model further improved the forecasting performance of the segmented models. A fully lumped stochastic model of the basin is developed and its forecasts are compared with those given by the segmented models. The results show that the segmented models provide better forecasts but exhibited more bias when compared to the unsegmented model of the basin. The results are obtained by using the data from the Green River Basin in Kentucky.
Defining the normal acetabular vault in adult males and females using a novel three-dimensional model

The management and quantification of bone loss is a major challenge in primary and revision total hip replacement. Defining the normal three-dimensional (3D) anatomy of the acetabular vault could aid in assessing pathologic changes and in designing prosthetic joint components. We performed a quantitative assessment of normal 3D acetabular vault structure to define the shape and location of weight-bearing acetabular bone referred to as the vault. Images from 70 normal hip computed tomography images were used to define the 3D acetabular vault anatomy and develop a 3D model. Variation in vault shape was quantified by measuring the distance between every surface point on a subject's hemipelvis and the reference vault. Variation among different hip alignments was assessed using 19 scans from subjects with varus, valgus and dysplastic hip morphologies. The acetabular vault model had 96.6% (95% CI: 91.7-101.5), 97.8% (95% CI: 94.5-101.1) and 96.4% (95% CI: 98.7-94.1) of the surface points within 3 mm of normal male, normal female and abnormal hip specimens, respectively. Comparison of acetabular vault model fit between gender and hip types revealed that it was only significantly different between normal males and normal females (P = 0.0194) and between normal males and dysplastic females (P = 0.0377). A conserved 3D acetabular vault shape and location exists that can accommodate various hip morphologies. Defining a normal vault may increase the precision with which hip pathology can be identified and may also serve as a preoperative assessment tool for planning total hip arthroplasty.
Civil Procedure—Class Actions—Seventh Circuit Reverses Lower Court's Approval of Class Action Settlement, Citing Evidence of Collusion.—Reynolds v. Beneficial National Bank, 288 F.3d 377 (7th Cir. 2002)

Class actions have the potential to increase the efficiency of litigation by eliminating duplicative lawsuits and improving plaintiffs' attorneys' investment incentives. But this potential efficiency gain comes at a cost. For instance, the divergence of plaintiffs' lawyers' interests from those of the class can lead to collusive settlements; for this reason, among others, class action settlements require judicial approval. In Reynolds v. Beneficial National Bank, the Seventh Circuit reversed a lower court's approval of such a settlement, reasoning that the settlement was collusive and inadequate. While the Seventh Circuit was probably right given the facts of this case, only the most egregious cases lend themselves to this kind of analysis. In most cases, the present system of judicial oversight of class settlements is fundamentally unworkable. The market for legal services, not judges' second-guessing, should regulate class action settlements. Rather than attempting the impossible task of valuing an entire litigation to determine whether a settlement is adequate, judges should concentrate on aligning plaintiffs' lawyers' incentives with those of the class through fee regulation or, even better, by letting lawyers buy plaintiffs' claims outright at auction.
An intelligent quasi-thesaurus for accessing information systems

, The information resources available through the Internet are immense. The total volume of the files accessible via the Internet is counted in thousands of gigabytes. The main problem however on the Internet is the flood of informa- tion and the difficulty of simply finding items. Therefore, the issue of identifying the relevant resources and accessing them is of crucial importance, in particu- lar from the casual users' perspective. As a rule users' specific knowledge about the network itself, and the distribution and contents of the information sources is limited. This paper addresses this issue by proposing a method help- ing the users to establish "good" queries and submitting them to the information resources (residing on the network) which are likely to contain the relevant documents. The core idea ofthe proposed approach is to create a self-Iearning mechanism supporting the queries' establishment and forwarding them to the right places within the network. The mechanism, called ADDRESSER, has been conceived as a simple quasi-thesaurus which is composed ofterms, URL addresses related to the terms and relations linking the terms. A prototype for testing and evaluating the idea was implemented. The experiments have proved the idea is viable, sound and workable.
Group-Wise Optimization of Common Brain Landmarks with Joint Structural and Functional Regulations

An unrelenting human quest regarding the brain science is: what is the intrinsic relationship between the brain’s structural and functional architectures, which partly defines what we are and who we are. Recent studies suggest that each brain’s cytoarchitectonic region has a unique set of extrinsic inputs and outputs, named as “connectional fingerprint”, which largely determines the functions that each brain area performs. However, their explicit connections are largely unknown. For example, in what extent they are inclined to be coherent with each other and otherwise they will intend to show more heterogeneity? In this work, based on a widely used brain structural atlas which represents the most consistent structural connectome across different populations, we proposed a novel group-wise optimization framework to computationally model the functional homogeneity behind them. The optimization procedure is conducted under the joint structural and functional regulations and therefore the achieved common brain landmarks reflect the consistency of brain structure and function simultaneously. The Human Connectome Project (HCP) Q1 dataset, which includes 68 subjects with high quality imaging data, was used as test bed and the results imply that there exists extraordinary accordance between brain structural and functional architectures.
Suctioning meconium from the trachea: a new solution to an old problem.

Meconium-stained amniotic fluid complicates between 5% and 15% of live births and is, therefore, a frequently encountered problem of both the pediatrician and obstetrician. The currently recommended protocol for combined obstetric and pediatric management is DeLee suction of the nasopharynx, mouth, and hypopharynx by the obstetrician as soon as the baby9s head appears. Immediately after delivery, the pediatrician suctions the oropharynx and inspects the cords. If meconium is present, the infant is intubated and the pediatrician places his or her mouth over the endotracheal tube and sucks the meconium from the trachea as the tube is removed.1,2 While this procedure has been proven successful in decreasing the incidence of meconium aspiration syndrome, the possibility of meconium entering the resuscitator9s mouth exists.
Simulation of Long Distance Wave Propagation in 2-D Sparse Random Media: A Statistical S-Matrix Approach in Spectral Domain

The problem of long distance wave propagation in a sparse random medium is considered in this paper. A mathematical technique for modeling the behavior of electromagnetic wave propagation as a function of distance in a 2-D sparse random media at millimeter wave (MMW) regime is presented. The proposed model is a field method based on Maxwell's equation and, thus, the phase and magnitude of the field in the random medium can be tracked accurately. The random media is characterized by low volume fraction but electrically large scatterers having relatively high dielectric constant. The technique relies on discretizing the random media into thin slabs and relating the forward and backward scattered plane wave spectra from the individual slabs by an equivalent spectral bistatic scattering matrix. By cascading the scattering matrices of the individual slabs, the statistics of the overall scattered wave in both forward and backward directions are obtained. This technique will be referred to as statistical S-matrix approach in spectral domain, or SSWaP-SD. Using this method, it is shown that after propagation to a critical range inside the random media, the incoherent component of the forward propagating wave overcomes the mean-field component resulting in a dual-slope attenuation curve as a function of distance. The accuracy of the model is examined against a full wave Monte Carlo simulation and a very good agreement is observed. Finally, based on the proposed model, analytical expressions for predicting the forward path-loss as well as the back scattered power from a sparse, translational invariant discrete random media are derived. The analytical expressions are tested against Monte Carlo simulation for a very long random medium and very good agreements are demonstrated.
Subsites and catalytic mechanism of ribonuclease T1: Kinetic studies using GpC and GpU as substrates

Abstract Steady-state kinetic studies on the ribonuclease T1-catalyzed transesterification of GpC and GpU were performed in the pH range 3–9 at 0.2 m ionic strength and 25 °C. Alkaline spectrophotometric titration of GpC and GpU indicated that the guanine and uracil moieties titrated independently and had a common apparent pK of 9.37. The values of the turnover number, kcat, and the Michaelis constant, Km, for GpC and GpU showed a similar but not identical variation with pH. The pH dependence of k cat K m for both substrates suggested the catalytic involvement of one unprotonated (pKA = 4.6) and two protonated (pKB = 7.7; pKC = 7.7–8.4) acid-base groups of the free enzyme. In the enzyme complex(es) with both GpC and GpU the apparent value of pKA decreased, whereas, the apparent values of pKB and pKC increased. The pH-independent values of kcat and Km were 398 s−1 and 1.9 × 10−4 m for GpC, respectively; and were 40 sec−1 and 2.8 × 10−5 m for GpU, respectively. The results suggest a different interaction of the leaving uridine and cytidine residues with an enzyme subsite but are consistent with a common catalytic mechanism for GpC and GpU.
Organ donation after traumatic cardiopulmonary arrest.

Abstract Background The gap between demand of transplantable organs and their supply continues to widen. Trauma patients constitute a significant proportion of organ donors. The incidence of organ donation after traumatic cardiopulmonary arrest (TCPA), however, is not clear. The goals of this study were to determine the success rate of organ donation in patients undergoing cardiopulmonary resuscitation (CPR) after trauma and to determine if there are variables that may predict successful organ donation. Methods All trauma patients who sustained TCPA from April 2007 to March 2010 were reviewed. We identified all patients who required CPR in the field or the trauma center. Patients were classified as donors if the heart, lung, kidney, small bowel, pancreas, or liver was harvested. Primary outcome was organ donation after CPR. Results A total of 252 patients required CPR for TCPA in the field or in the trauma center. There were 39 (15.5%) survivors and 213 (84.5%) fatalities. Only 19 of 213 (8.9%) patients who died after TCPA became organ donors. A total of 26 organs were harvested including 15 kidneys, 6 livers, 4 hearts, and 1 pancreas. Of those who failed to donate organs, 64.7% had a cardiac arrest after the donor network had been contacted but before their arrival. Conclusions Survival rate after TCPA is low but organ donation is an important secondary outcome. Patients with predominant head injuries, without thoracic and minimal extremity injuries, should be identified as having a higher chance of going on to organ donation. The greatest barrier to organ donation in TCPA patients is cardiac arrest before donor network arrival.
The impact of diaphragm management on prolonged ventilator support after thoracoabdominal aortic repair

Abstract Purpose: The relationship of the division of the diaphragm during thoracoabdominal aortic repair to prolonged ventilator support has not been studied. The purpose of this study was (1) to determine whether preservation of diaphragm integrity has a significant effect on postoperative ventilator duration and (2) to elucidate other pulmonary risk factors related to thoracoabdominal aortic surgery and to study the relationship of these factors to the intact diaphragm technique. Methods: Between February 1991 and January 1997, we repaired 397 descending and thoracoabdominal aortic aneurysms. Descending thoracic aneurysms were not included in the study because their repair does not include the diaphragm. A total of 256 patients participated in this study. The diaphragm was divided in 150 patients and left intact in 106 patients. Examined as potential risk factors were patient demographics, history and physical findings, aneurysm extent, urgency of the procedure, acute dissection, cross-clamp time, homologous and autologous blood product consumption, and adjunctive operative techniques. FEV 1 also was considered in the 197 patients for whom preoperative spirometry was available. Prolonged mechanical ventilation was defined as ventilator support for >72 hours. Data were analyzed by univariate contingency table and multiple logistic regression methods. Results: Increasing age (odds ratio [OR], 1.02/y; P P P P P P Conclusion: Independently of well known pulmonary risk factors, an intact diaphragm during thoracoabdominal aortic repair results in a higher probability of early ventilator weaning. (J Vasc Surg 1999;29:150-6.)
A method for direct cross-linking of DNA bases containing aromatic amino groups to proteins

A one step method to cross-link DNA bases containing aromatic amino groups directly to proteins was developed. No chemical modification of the base is required prior to conjugation, which is performed at neutral pH. Work focused on 8-oxoguanine and the carrier protein, bovine serum albumin. Conjugates were stable after sodium dodecyl sulfate (SDS)-induced protein denaturation and were characterized by UV spectroscopy, enzyme linked immunosorbent assay (ELISA), SDS-polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblot analyses. This method is a viable alternative to existing procedures for generating DNA base-protein conjugates for antibody characterization and affinity purification.
Functional enucleation of bovine oocytes: Effects of centrifugation and ultraviolet light

Abstract Functional enucleation is removal or denaturation of an oocytes DNA without piercing the zona pellucida. Two experiments were conducted in this study to determine the effects of centrifugation, and ultraviolet (UV) light on metaphase II bovine oocytes. Experiment 1 evaluated the effects of centrifugation (12,000 × g for 4 min) on the cleavage rate of in vitro matured oocytes. Centrifugation decreased (P
Medicolegal Implications of Colon Cancer Screening

The treatment of colon cancer is a significant source of malpractice liability. Physicians are justifiably concerned about malpractice exposure as personal injury attorneys investigate standard and novel malpractice theories and claims. With the general acceptance of the importance of screening for colon cancer, screening for colon cancer is now defined as the standard of care. This has opened up a previously neglected area of malpractice liability. Physicians need to understand the sources of malpractice risk and risk-management strategies related to these sources to reduce their exposure to liability suits in this area. This article outlines these sources evolving from the tort of negligence, including the duty to provide care, practicing below the standards of care, the cause of the harm, and the actual establishment of harm. The concept of vicarious liability and its relationship to the tort of negligence also are discussed. This presentation is developed within the context of a risk-management approach to assist physicians in developing a preventive approach to malpractice liability.
The private stake in public goods: overcoming the illogic of collective action

According to the Logic of Collective Action, most actions in the service of common interests are either not logical or not collective. In a large group, the argument goes, individual action counts for so little in the realization of common interests that it makes no sense for a person to consider group interests when choosing a course of personal conduct. Only private interests are decisive. Their fulfillment, at least, depends in a substantial way on one's own behavior. Individual actions designed to achieve private advantage are therefore rational. Actions aimed at collective goods are a waste of time and effort.
Nitrogen and phosphorus enrichment alter the composition of ammonia-oxidizing bacteria in salt marsh sediments

Ammonia oxidation is a central process in the nitrogen cycle. Particularly in marine and estuarine environments, few experiments have been conducted to tease apart the factors influencing their abundance and composition. To investigate the effect of nitrogen and phosphorus availability on ammonia-oxidizing bacteria (AOB), we conducted a nutrient enrichment experiment in a Maine salt marsh and sampled sediment communities in three seasons over 2 years. We assessed community composition using terminal restriction fragment length polymorphism analysis and sequencing of cloned fragments of the ammonia monooxygenase (amoA) gene. Almost all of the amoA sequences fell within the marine and estuarine-specific Nitrosospira-like clade. Applied separately, nitrogen and phosphorus significantly altered AOB composition; however, together the nutrients had an interactive effect, and composition did not change. In contrast, nutrient enrichment did not alter AOB abundance. Furthermore, the response of AOB composition to nutrient enrichment varied over time. We conclude that closely related taxa within the marine/estuarine-specific Nitrosospira-like clade vary in their preference for nutrient concentrations, and this preference may depend on other temporally variable abiotic factors. Finally, AOB composition was highly variable within and across years even in untreated plots. Further studies are needed to test how these different aspects of compositional variability in AOB communities influence nitrogen cycling.
The changing unnatural history of valvular regurgitation.

Abstract In the past 15 years three major advancements have improved the lot of our patients with left-sided valvular regurgitation. First, the concept that mitral and aortic regurgitation were similar volume overloading lesions has changed. Mitral regurgitation constitutes a nearly pure volume overload wherein the excess volume is ejected against relatively low pressure into the left atrium. On the other hand, aortic regurgitation represents a combined pressure and volume overload in which the excess volume being pumped is ejected against the relatively high pressure of the aorta. These differences in loading between mitral and aortic regurgitation produce a different response to operation. Afterload reduction after correction of aortic regurgitation increases ejection performance if it was decreased preoperatively. Conversely, afterload increases after mitral valve replacement, decreasing ejection performance. These differences make the left ventricle in mitral regurgitation less tolerant of preoperative dysfunction than the left ventricle in aortic regurgitation. Second, with respect to aortic regurgitation, reproducible indexes have been developed that identify when left ventricular dysfunction is present, leading to earlier operation in an attempt to avoid permanent ventricular dysfunction. In turn, earlier operation has led to a fall in operative mortality rate and an almost universal increase in left ventricular function if it was depressed preoperatively. Third, with regard to mitral regurgitation, recognition of the importance of the mitral valve apparatus in maintaining left ventricular function has led to an increased emphasis on chordal preservation during mitral valve operations. Early indicators suggest that these techniques will lead to improved postoperative left ventricular function, reduced operative mortality, and enhanced long-term survivorship for patients with mitral regurgitation. Thus, a change in concept regarding the pathophysiology of these lesions, a change in referral for patients with aortic regurgitation, and a change in operation for patients with mitral regurgitation have led to a favorable alteration in the unnatural history of left-sided valvular regurgitation.
Wavelet-based moment invariants for pattern recognition

Moment invariants have received a lot of attention as features for identification and inspection of two-dimensional shapes. In this paper, two sets of novel moments are proposed by using the auto-correlation of wavelet functions and the dual-tree complex wavelet functions. It is well known that the wavelet transform lacks the property of shift invariance. A little shift in the input signal will cause very different output wavelet coefficients. The autocorrelation of wavelet functions and the dual-tree complex wavelet functions, on the other hand, are shift-invariant, which is very important in pattern recognition. Rotation invariance is the major concern in this paper, while translation invariance and scale invariance can be achieved by standard normalization techniques. The Gaussian white noise is added to the noise-free images and the noise levels vary with different signal-to-noise ratios. Experimental results conducted in this paper show that the proposed wavelet-based moments outperform Zernike's moments and the Fourier-wavelet descriptor for pattern recognition under different rotation angles and different noise levels. It can be seen that the proposed wavelet-based moments can do an excellent job even when the noise levels are very high.
Higher Adiponectin Levels Predict Greater Weight Gain in Healthy Women in the Nurses' Health Study

Adiponectin and resistin's possible roles in weight regulation have received little attention. We tested the hypothesis that adipokine levels predict future weight gain in women in the Nurses' Health Study. Among women who provided blood samples in 1990, we studied 1,063 women who did not develop diabetes (“healthy”) and 984 women who subsequently developed diabetes. Total and high-molecular-weight (HMW) adiponectin and resistin levels were measured using enzyme-linked immunosorbent assay. Women who did not developed diabetes had a mean BMI of 26.3 ± 6.0 kg/m2 at baseline and gained 2.0 ± 6.1 kg over 4 years. Women who developed diabetes had a mean BMI of 30.1 ± 5.4 kg/m2 at baseline, and gained 2.4 ± 7.1 kg over 4 years. In women who did not developed diabetes, higher baseline levels of total and HMW adiponectin were associated with significantly greater weight gain after adjustment for age, BMI, physical activity, diet, and other covariates: women in the highest quintile of total adiponectin gained 3.18 kg compared to women in the lowest quintile who gained 0.80 kg (fully adjusted; P for trend <0.0001). Adiponectin was not significantly associated with weight gain in women who subsequently developed diabetes. Resistin levels were not associated with weight gain in either women who did or did not develop diabetes during the follow-up. We conclude that elevated adiponectin levels are associated with higher weight gain in healthy women, independent of confounding risk factors. High adiponectin production by adipocytes might be a sign of “healthy” adipose tissue with further capacity to store fat.
On the Relationship between Polymer Electrolyte Structure and Hydrated Morphology of Perfluorosulfonic Acid Membranes

Molecular dynamics simulations were performed to investigate the relationship between the molecular structure of perfluorosulfonic acid (PFSA) ionomers and the nanoscale morphology of the hydrated membranes. Three structural features are examined including (i) the length of the side chain to which the sulfonic acid group is attached, (ii) the equivalent weight (EW) of the electrolyte ionomer, and (iii) the molecular weight (MW) of the polymer electrolyte. Membrane morphologies are studied from the water content λ = 3 (λ represents number of water molecules per sulfonate group) to saturation (λ = 22). We find that with the longer side chain, there is more clustering of the sulfonate groups and more local water−water clustering, but a more poorly connected aqueous domain. When one decreases the equivalent weight (EW) in either the short side chain (SSC) PFSA or Nafion, there is more clustering of the sulfonate groups and more local water−water clustering and a better connected aqueous domain. Because connec...
A quasi-distributed architecture for database management systems

This paper describes a new architecture for database management systems. This quasi-distributed architecture is a compromise between the traditional centralized architecture and the more recent distributed architecture. As such it provides benefits over both architectures but also has limitations when compared with them. The quasi-distributed architecture is made possible from recent advances in computer technology: it uses economical workstations to place more of the processing at remote sites, and it uses the increased storage capacity of CD-ROMs, WORMs and hard disks to store more data closer to where it will be used. The paper gives an overview of the quasi-distributed architecture and discusses its advantages, disadvantages, and limitations. Although it is not a general purpose architecture, it is suitable for certain situations.
Amber mutants in the O gene of bacteriophage λ are not efficiently complemented in the absence of phage N function

Abstract Mutants of bacteriophage λ carrying mutations in the replication genes O and P are complemented efficiently by O + P + phages under normal conditions of lytic growth. When analogous complementation tests are performed under N − conditions, however, P − mutants are efficiently complemented but Oam 29 is not. This defect in O complementation is alleviated by the mutation of ri 5b c and is not observed with the nonamber mutation Ots 21. These and other data suggest that, in the absence of N function, the Oam 29 mutations exerts a cis effect on the development of genomes carrying it. The most likely explanation for this cis effect is that the amber codon interfers with transcriptional activation of λ DNA replication.