cssi/SciSciGPT-SciSciNet huggingface dataset:
Sodium and chloride sorption by imogolite and allophanes

The surface excesses of Na and CI on synthetic imogolite and allophanes with varying A1/Si molar ratios in 0.I0 M and 0.01 M NaC1 solutions were determined using 22Na and 36C1 as ion probes. The point of zero net charge (PZNC) values ranged from 4.1 to 8.4, increasing with the Al/Si molar ratio for the allophanes, and was highest for imogolite (A1/Si = 2.01). The PZNC values were significantly lower than the point of zero charge (PZC) values previously determined by microelectrophoresis for the same material, indicating that Na resided within the shear plane to a greater extent than C1. The PZNC values of allophanes were lower than their PZSE values, indicating that permanent charge existed in allophanes, and increased as A1/Si decreased. Conversely, the PZNC of imogolite was higher than its point of zero salt effect (PZSE) determined by potentiometric titration. Adsorption of C1 on imogolite from 0.1 and 0.01 M NaCl solutions below pH 8.4 and of Na from 0.1 M NaCl solutions between pH 5 and 8.4 exceeded the proton charge determined by potentiometric titration. There was no direct evidence of permanent charge in imogolite and excess C1 adsorption could not be entirely explained by simultaneous intercalation of Na and Cl. Isomorphic substitution of A1 in tetrahedral sites was shown to increase with decreasing A1/Si by 27A1 high-resolution solid-state nuclear magnetic resonance (NMR) spectra of allo- phanes, and was absent in imogolite. The chemical shifts of Al(4) and Al(6) were similar in allophanes (63.0-64.7 ppm and 6.1-7.8 ppm, respectively) and the chemical shift of Al(6) was 9.4 in imogolite.
Influence of Citric and Ascorbic Acids on Electrodeposited Au/FeAu Multilayer Nanowires

AuFe electrodeposits onto a rotating disk electrode were examined to assess the composition and current efficiency behavior when citric acid, ascorbic acid, or a combination of both is present in the electrolyte. Nanowires were subsequently fabricated with pulsed current deposition to create compositionally, multilayered Au/FeAu nanowires. The FeAu layer of the nanowires was porous in a citrate electrolyte, but the porosity decreased with the addition of ascorbic acid in the electrolyte. Comparatively higher side reaction partial current densities (i sr ) in the citric acid electrolyte generated local alkaline conditions, inducing the chemical precipitation of Fe ions in the form of iron oxide nanoparticles inside the recess, which manifested as the regions of high porosity. Nonporous layers observed in the ascorbic acid bath, in combination with decreased i sr and increased current efficiency of the deposits, suggested that a similar mechanism of Fe precipitation inside the nanorecess is less likely.
Quantum mechanical effects in internal photoemission THz detectors

The variation in spectral shape around the threshold frequencies between model and experimental responsivity spectra in heterojunction interfacial workfunction internal photoemission (HEIWIP) infrared detectors was investigated. This is attributed to the loss of photoexcited carriers, within the escape cone, prior to photoemission. The energy dependent transmission of excited carriers is incorporated to the existing photoemission model to show that emission around the threshold frequency is reduced considerably by quantum mechanical reflection of photoexcited carriers as observed in experimental results. In the new model, the photoemission of carriers become bias dependent.
MATING BEHAVIOR AND FEMALE-PRODUCED PHEROMONE USE IN TROPICAL SOD WEBWORM (LEPIDOPTERA: CRAMBIDAE)

Abstract Research was initiated to develop a pheromone-based monitoring system for the tropical sod webworm, Herpetogramma phaeopteralis (Guenee). A laboratory rearing procedure was developed to produce individuals for field tests and behavioral bioassays. Virgin females placed in Unitraps in the field attracted and captured males for 8 d, while no males were captured in unbaited traps. Total male capture ranged from 1 to 24, and there was a slight decrease in capture as females aged. Laboratory mating behavior studies suggested that mating occurs later in the scotophase. Males responded to virgin females in a linear olfactometer throughout the dark period (scotophase), although there was a trend for higher male activity late in scotophase. There was no observed calling behavior, and adults exhibit simple mating behavior. Lack of both calling posture among virgin females and periodicity of male response will make it difficult to determine the optimal time periods for pheromone production, which would faci...
The Effects of Race, Income, Mobility and Political Beliefs on Support For Redistribution

A questionnaire is used to assess the impact of race, current past and future family income, as well as political beliefs on the support for redistribution. Current income maximization predicts those with above average income oppose redistribution. However blacks support redistribution until income is well above average and whites oppose redistribution even if income is well below average. Those with incomes below average expect to move up and this prospect of upward mobility reduces support for redistribution. The rich are more likely to espouse arguments that protect their wealth. Most intriguingly, as blacks become richer, support for redistribution falls especially rapidly.
Assessing services with communicatively impaired bilingual adults in culturally and linguistically diverse neurorehabilitation programs

Abstract The combined effect of the steady increase in cultural and linguistic diversity and epidemiological factors in minority populations is estimated to continue having an impact on adult neurorehabilitation programs in the country, particularly in the number of bilingual individuals receiving clinical services. No comprehensive assessment of the present professional and clinical realities in service delivery to communicatively impaired adults in culturally and linguistically diverse (CLD) neurorehabilitation contexts has been conducted. The current survey research was undertaken to examine current professional training, clinical practices, and challenges in the services rendered to the steadily increasing numbers of communicatively disordered adults in CLD neurorehabilitation programs with a special focus on bilingual persons. A 36-question, 6-section survey was administered to health care-based SLPs working with adults to examine multiple factors regarding work setting and caseload, professional training, clinical tools and procedures, service delivery issues, and suggestions to improve clinical work with bilingual adults in CLD neurorehabilitation environments. Results support that SLPs presently make sensible decisions to serve communicatively disordered bilingual adults with neuropathologies despite training gaps and scant clinical resources. Responses additionally highlight critical areas to improve professional preparation and available resources. Results are discussed in terms of strengths and weaknesses as well as their implications to professional education and target research areas in order to minimize present gaps in service delivery with bilingual speakers in CLD adult neurorehabilitation programs. Learning outcomes : As a result of this activity, the reader will be able to: (1) Discuss the demographic and epidemiological factors that suggest a continued increase in the number of communicatively impaired bilingual adults in CLD neurorehabilitation programs. (2) Describe current strengths and weaknesses in the diagnostic and therapeutic practices employed by SLPs with bilingual clients in CLD adult neurorehabilitation programs. (3) Describe possible strategies to improve current limitations in professional training and clinical resources that would strengthen the current services given to bilingual adults in CLD neurorehabilitation programs.
Structural Insight for Roles of DR5 Death Domain Mutations on Oligomerization of DR5 Death Domain–FADD Complex in the Death-Inducing Signaling Complex Formation: A Computational Study

Death receptor 5 (DR5)-induced apoptosis that prioritizes the death of tumor cells has been proposed as one of the promising cancer therapies. In this process, oligomerized DR5 death domain (DD) binding to Fas-associated death domain (FADD) leads to FADD activating caspase-8, which marks the formation of the death-inducing signaling complex (DISC) that initiates apoptosis. DR5 DD mutations found in cancer cells have been suggested to play an important pathological role, the mechanism through which those mutants prevent the DR5-activated DISC formation is not clear yet. This study sought to provide structural and molecular insight for the roles of four selected DR5 DD mutations (E355K, E367K, K415N, and L363F) in the oligomerization of DR5 DD–FADD complex during the DISC formation. Results from the molecular dynamics simulations show that the simulated mutants induce conformational, dynamical motions and interactions changes in the DR5 DD–FADD tetramer complex, including changes in a protein’s backbone flexibility, less exposure of FADD DED’s caspase-8 binding site, reduced H-bonding and hydrophobic contacts at the DR5 DD–FADD DD binding, altered distribution of the electrostatic potentials and correlated motions of residues, and reduced binding affinity of DR5 DD binding to FADD. This study provides structural and molecular insight for the influence of DR5 DD mutations on oligomerization of DR5 DD–FADD complex, which is expected to foster understanding of the DR5 DD mutants’ resistance mechanism against DR5-activated DISC formation.
Adverse Metabolic Consequences of Nutritional Support: Macronutrients

The administration of a complete and well-balanced diet commensurate with the requirements and limitations of individual patients is essential to obtain maximal benefit of nutritional therapy. Complications related to the provision of nutritional therapy must be considered when providing nutrition support to patients with malignant diseases. Some of these complications are not exclusive of the form of therapy, whereas others are inherent in the different components of nutrient solutions used. A sound knowledge of clinical nutrition as well as the establishment of nutrition support teams will help to reduce the incidence of adverse reactions related to the nutritional treatment. Further research is necessary to understand better the mechanisms of malnutrition in cancer patients and the mechanisms by which several organs and systems are adversely affected during nutrition support. New methods and devices will lead to a more efficacious administration of nutritional requirements.
Predicting the tolerance level of religious discourse through computational linguistics

Religious violence is one of the biggest and most complicated problems facing the world today. The number of incidents has been increasing in recent years and, unfortunately, scalable and accurate systems to predict which groups are likely to engage in such actions are not keeping pace. Additionally, this problem is compounded by lingual and cultural differences, which limit the effectiveness of understanding how tolerant or intolerant a group is without bias. To circumvent this challenge, recent studies indicate promise in the analysis of the performative character of discourse (how words are used) to estimate the tolerance level, rather than using the semantic or emotive character of text (what the words mean or imply). Using expert estimates of linguistic flexibility, a representation of the performative character of text, and thus also predictive of a text's tolerance level, this paper describes (a) new approaches to automating the quantification of the performative character of words and (b) the predictive efficacy of these approaches versus traditional semantic indicators of tolerance or intolerance. To implement the pipeline, a judgment identifier was developed along with multiple semantic density algorithms to extract the frequency of judgments and flexibility of keyword contexts, respectively. Test results show that text mining algorithms can accurately estimate the language flexibility of religious discourse. These results provide evidence that the performative characteristics of language better predict tolerance level than the semantic characteristics of language.
Can student engagement serve as a motivational resource for academic coping, persistence, and learning during late elementary and early middle school?

How children and youth deal with academic challenges and setbacks can make a material difference to their learning and school success. Hence, it is important to investigate the factors that allow students to cope constructively. A process model focused on students’ motivational resources was used to
The CFPB's Arbitration Rule: The Road Ahead

In May 2016, the Consumer Financial Protection Bureau announced that it intended to exercise its authority under the Dodd-Frank Act to bar consumer financial companies from invoking pre-dispute arbitration agreements to block consumer class actions. This comment considers the most serious threats to the Bureau's arbitration rule and concludes that its prospects are bad. Under Trump, banks and credit card companies will continue to avoid class-action litigation by mandating individual arbitration and there is little that supporters of the Bureau's rule can do about it.
Conducting Research in Lebanon: An Overview of Historical Sources Outside of Beirut (Part II)

Recent years have witnessed a concerted effort by researchers, archivists and others to preserve, catalog, and inform researchers about the many types of sources located in Lebanon. The publication of Part I of this guide to conducting historical research [see MESA Bulletin 37:1 (Summer 2003): 68-79] addressed archives, libraries, and institutes located in Beirut. This article is dedicated to those found in the rest of the country.As with Part I, the archives and sources surveyed below comprise those that are open to the public and deemed to have the most potential for researchers. Although likely to be of most relevance to historians, these sources are such that they should also prove useful to scholars from other fields. Furthermore, access is constantly improving, thanks in no small part to the efforts underway at multiple institutions to organize and digitize manuscripts, court records, and a host of other documents.
The Discovery of the Muon

Half a century after the surprising result of the experiments done in Rome by Conversi and myself [1,2] at the Lyceum Virgilio and later on with Pancini [3,4] at the University of Rome, it is perhaps interesting, and maybe useful, to identify the ingredients that brought about the discovery of the muon and of the leptonic property.
Association of Patient Age With Outcomes of Current-Era, Large-Scale Screening Mammography: Analysis of Data From the National Mammography Database

This study analyzes mammography screening data from the National Mammography Database to determine the age cutoff point for screening.
REE mobility and fractionation during shale weathering along a climate gradient

Abstract We systematically investigated six soil profiles developed on a climosequence of gray shale to constrain the mobility and fractionation of rare earth elements (REE) during chemical weathering processes. In addition, one site developed on black shale (Marcellus Formation) was included to document REE behaviors in organic-rich versus organic-poor shale end members under the same environmental conditions. Our study shows that REE are mobilized intensively during shale weathering and the extent of depletion is larger under warm/humid climates. However, the integrated release rates calculated from six soil profiles are not directly correlated to mean annual precipitation or temperature. Instead, the primary control might be the REE concentrations in the most reactive minerals. REE-bearing phases in shale (sulfides, phosphates and organic matter) probably react quickly at first, mobilizing REE. Following that, REE are then released more slowly during dissolution reactions of clay minerals. Consistent with this interpretation, black shale weathers much faster and releases more REE than gray shale under the same climate conditions, due to the higher organic matter and sulfide contents and lower soil pH. REE are not 100% depleted in any of the investigated soil sites; in northern sites, depletion is minimal whereas in the southern (warm and humid) sites, surface depletion is higher and re-deposition is observed at depth. Retention of REE is likely caused by adsorption to mineral surfaces as pH increases and dissolved organic matter content decreases with depth. This case study quantified loss, redistribution and fractionation of REE during shale weathering, improved our understanding of REE mobility in surficial environments, and contributed to the exploration of REE as strategic mineral resources.
Investigation of the Temporal Parameters in Omission Training with Humans in a Two-Key Situation

Following concurrent variable interval pretraining, Ss were assigned to 1 of 4 omission schedules derived by factorially combining 10- and 30-sec. interreinforcement intervals with 10- and 30-sec. postresponse intervals. The Ss then underwent first elimination, key reversal, and durability conditions. The omission-key response was eliminated by omission schedules in which a response functioned to decrease reinforcement density. However, omission key. responding was maintained by the omission schedule in which reinforcement frequency could be increased by an occasional response. The second key was programmed for extinction. Nevertheless, Ss continued to press this key. The behavioral effects of the four omission schedules proved to be durable when reinforcement was scheduled independent of responses on either key.
Prevalence of Trichomonas, Salmonella, and Listeria in Wild Birds from Southeast Texas

Infectious diseases can be a major threat to wildlife populations, especially in human-modified habitats, but infection rates in populations of wild animals are often poorly studied. Trichomonas, Salmonella, and Listeria are all pathogens known to infect birds, but their infection rates in wild bird populations are not well documented. This study documents infection rates of the three pathogens in wild bird populations inhabiting a suburban to rural gradient in Southeast Texas. Various species of wild birds were sampled at five sites in Southeastern Texas representing rural (<1 house per ha), exurban (approximately 1 house per ha), and suburban (approximately 10 houses per ha) habitat types. Birds were captured in mist nets and samples were taken from the oral cavity, crop, and vent to detect the presence of pathogens. Samples were screened for Trichomonas by examining wet mounts under a light microscope, whereas samples were screened for Salmonella and Listeria by examining colonies grown on agar plates. Pathogens detected during the initial screening were further confirmed by PCR and DNA sequencing. Infection rates for Trichomonas, Salmonella, and Listeria were 9%, 17%, and 5%, respectively. The distributions of infection rates across habitats (i.e., rural, exurban, rural) did not differ significantly from the expected null distributions for any of the three pathogens; however, the data suggested some interesting patterns that should be confirmed with a larger dataset. Infection rates for Trichomonas and Salmonella were highest at the suburban sites, whereas the infection rate for Listeria was highest at the rural site. Feeder birds were more likely to be infected by all three pathogens than non-feeder birds. Small sample sizes prevent definitive conclusions regarding variation in infection rates along the suburban to rural gradient, but the results suggest that pathogens followed the predicted patterns. For many of the bird species sampled, this study presents the first report of infection rates by these three pathogens in wild populations.
Palatal tremor as a presenting symptom of amyotrophic lateral sclerosis.

Palatal tremor, also known as palatal myoclonus, is a sign caused by a lesion to the Guillain-Mollaret triangle. In some cases, imaging may also reveal hypertrophic olivary degeneration, which is due to trans-synaptic degeneration and gliosis of the inferior olivary nucleus. The underlying etiology is commonly due to unilateral involvement of the central tegmental tract due to ischemic, neoplastic, demyelinating, traumatic, inflammatory, and rarely neurodegenerative processes such as progressive supranuclear palsy, multiple system atrophy, and Alexander disease.1 We describe a patient who presented with palatal tremor as the presenting symptom of amyotrophic lateral sclerosis (ALS).
A reassessment of tracheal substitutes-a systematic review.

Background: Tracheal substitutes remain an active area of research. For rare patients with large or complex defects that cannot be repaired primarily, replacement of the airway may represent the only treatment option. The present systematic review aims to assess the clinical successes and setbacks of current methods of airway replacement. Methods: Systematic review using Medline and PubMed from 01 January 2000 to 01 October 2017 focusing on clinical translation of circumferential or near circumferential (>270°) tracheal substitutes. Studies were identified using key phrases including terms such as “tracheal replacement”, “tracheal regeneration”, “tracheal transplant”, “tracheal tissue engineering”, and “tracheal substitution”. Animal or non-clinical studies were excluded. Reviews were included if they contained clinical updates. Results: Twenty-one studies were included in assessment comprising a mix of case reports, case studies, and a single review with clinical updates on prior studies. Since 2001, 41 patients have undergone a reported circumferential or near circumferential tracheal substitution through four underlying methodologies including allotransplantation, autologous tissue reconstruction, bioprosthetic reconstruction, and tissue engineered reconstruction. Each modality has unique advantages and disadvantages with varying success in clinical application. Conclusions: The need for tracheal substitution remains a difficult clinical problem without an ideal prosthetic or graft material. While various modalities have had limited clinical success, further laboratory work is necessary before tracheal substitutes can become widely adopted, especially in the case of tissue engineered conduits, which have been setback by premature clinical translation.
The Governance Committee Process for U.S. Publicly Traded Firms

ABSTRACT The Governance Committee (GC) is responsible for overseeing the effective functioning of the board of directors, but no previous research has been done on the GC process. Through in-depth ...
Robotic Spine Exoskeleton (RoSE): Characterizing the 3-D Stiffness of the Human Torso in the Treatment of Spine Deformity

Spine deformity is typically treated with a brace that fits around the torso and hips to correct the abnormal curve of the spine. While bracing has been shown to curtail progression of abnormal spine curves, current braces impose several limitations due to their rigid, static, and sensor-less designs: (1) forces and moments exerted by the brace cannot be measured or modulated and (2) the 3-D stiffness of the human torso has not been characterized—these may be important factors to be considered in bracing treatment. We address these limitations using a robotic spine exoskeleton (RoSE), capable of controlling the position/orientation of specific cross sections of the human torso while simultaneously measuring the forces/moments exerted on the body. Eight healthy subjects and two subjects with spine deformity participated in a study to characterize the 3-D stiffness of their torso. The results show that the 3-D stiffness of human torso can be characterized using RoSE and indicated that the spine deformities induce torso stiffness characteristics significantly different from the healthy subjects. These characteristics are curve-specific and present a pronounced asymmetry. These results open up the possibility for the design of spine braces incorporating patient specific torso stiffness characteristics and potential for new interventions using the dynamic modulation of 3-D forces for spine deformity treatment.
Oxidative Stress and Preterm Birth

Preterm birth (PTB) is a clinically important and heterogeneous syndrome leading to neonatal compromise. This chapter proposes that oxidative stress (OS) and the complex biology of OS may specifically contribute significantly to pathways implicated in PTB, including inflammation, apoptosis, autophagy, senescence, and altered collagen metabolism. This chapter further suggests that the apparent conflict in the association between exposure to OS and PTB seen in epidemiologic studies on the one hand and the apparent lack of effect in antioxidant therapy in clinical trials to improve clinical outcome on the other stems from the need for a more complete understanding of the underlying biology of ROS.
The Structural Effects of pH on Concentrated Aqueous Ammonium Dihydrogen Phosphate by Laser Raman Spectroscopy

ABSTRACT The structure of pure, concentrated aqueous solutions of dihydrogen orthophosphates is composed of “free” and hydrogen-bonded anions. The influence of pH on the structure of ammonium dihydrogen phosphate solutions from pH 3.8 to 5.0 has been investigated using laser Raman spectroscopy. Except for the appearance of the (OH)P–O3 symmetric stretching vibration, the spectra show little evidence of structural breakup that could account for the increased ease of crystal growth at the higher pH.
Treatment of Gastro-Fundal Varices (Including a Discussion of BRTO)

The goal of our review is to provide a better understanding of the anatomy of gastric varices (GV) and to provide guidance regarding the management of bleeding GV. Despite a paucity of head-to-head controlled data in this field, there remain no further advances in therapy. Alterations to previous techniques, such as combining EUS-guided metallic coil injection with cyanoacrylate injection or approaching endovascular therapies such as balloon-occluded retrograde transvenous obliteration (BRTO) via different pathways, have been developed but not studied in a comparative manner. The primary therapy of GV is endoscopic cyanoacrylate injection and new studies have confirmed prior data suggesting this is effective with low complication and re-bleeding rates. Similarly, endovascular procedures such as BRTO continue to show robust results but no large, controlled, head-to-head trials exist to compare different modalities of therapy. Herein, we review the current literature for the therapy of bleeding GV and voice a call to action for future research endeavors in this field.
The effect of antibiotics on the gut microbiome: a metagenomics analysis of microbial shift and gut antibiotic resistance in antibiotic treated mice

Emergence of antibiotic resistance is a global public health concern. The relationships between antibiotic use, the gut community composition, normal physiology and metabolism, and individual and public health are still being defined. Shifts in composition of bacteria, antibiotic resistance genes (ARGs) and mobile genetic elements (MGEs) after antibiotic treatment are not well-understood. This project used next-generation sequencing, custom-built metagenomics pipeline and differential abundance analysis to study the effect of antibiotic monotherapy on resistome and taxonomic composition in the gut of Balb/c mice infected with E. coli via transurethral catheterization to investigate the evolution and emergence of antibiotic resistance. There is a longitudinal decrease of gut microbiota diversity after antibiotic treatment. Various ARGs are enriched within the gut microbiota despite an overall reduction of the diversity and total amount of bacteria after antibiotic treatment. Sometimes treatment with a specific class of antibiotics selected for ARGs that resist antibiotics of a completely different class (e.g. treatment of ciprofloxacin or fosfomycin selected for cepA that resists ampicillin). Relative abundance of some MGEs increased substantially after antibiotic treatment (e.g. transposases in the ciprofloxacin group). Antibiotic treatment caused a remarkable reduction in diversity of gut bacterial microbiota but enrichment of certain types of ARGs and MGEs. These results demonstrate an emergence of cross-resistance as well as a profound change in the gut resistome following oral treatment of antibiotics.
Development and comprehensive commissioning of an automated brachytherapy plan checker.

Abstract Purpose To present on the commissioning of an automated brachytherapy plan checker (BPC) for the evaluation of high-dose-rate brachytherapy treatment plans in support of standardized workflows and patient safety. Methods and Materials A BPC was developed using an applications programming interface in a commercial treatment planning system based on different inputs (e.g., regulations, professional society recommendations, and user feedback) and leveraged our experience with an in-house developed external beam plan checker. The BPC was commissioned using a comprehensive suite of test plans with known errors and anonymized clinical plans. Results During commissioning, the BPC was successfully executed on a total of 87 test plans. Commissioning tests spanned a range of treatment sites and evaluated that pass and fail states were correct. Administration settings were changed in a nonclinical database to evaluate tests involving the source and afterloader. Clinical testing of the BPC was then performed in parallel with a manual review process before clinical implementation. Conclusions To commission the BPC for clinical use, a comprehensive suite of test plans was developed and used to ensure the BPC correctly detected and reported errors. A summary of the test plans is presented to help guide users developing similar automated tools. The BPC represents a process-improvement initiative designed to reduce errors and improve safety for brachytherapy patients. By using a comprehensive test suite for commissioning, tests are available for periodic quality assurance and after software upgrades.
Numerical manifold method modeling of coupled processes in fractured geological media at multiple scales

Author(s): Hu, M; Rutqvist, J | Abstract: The greatest challenges of rigorously modeling coupled hydro-mechanical (HM) processes in fractured geological media at different scales are associated with computational geometry. These challenges include dynamic shearing and opening of intersecting fractures at discrete fracture scales as a result of coupled processes, and contact alteration along rough fracture surfaces that triggers structural and physical changes of fractures at micro-asperity scale. In this paper, these challenges are tackled by developing a comprehensive modeling approach for coupled processes in fractured geological media based on numerical manifold method (NMM) at multiple scales. Based on their distinct geometric features, fractures are categorized into three different scales: dominant fracture, discrete fracture, and discontinuum asperity scales. Here the scale is relative, that of the fracture relative to that of the research interest or domain. Different geometric representations of fractures at different scales are used, and different governing equations and constitutive relationships are applied. For dominant fractures, a finite thickness zone model is developed to treat a fracture as a porous nonlinear domain. Nonlinear fracture mechanical behavior is accurately modeled with an implicit approach based on strain energy. For discrete fractures, a zero-dimensional model was developed for analyzing fluid flow and mechanics in fractures that are geometrically treated as boundaries of the rock matrix. With the zero-dimensional model, these fractures can be modeled with arbitrary orientations and intersections. They can be fluid conduits or seals, and can be open, bonded or sliding. For the discontinuum asperity scale, the geometry of rough fracture surfaces is explicitly represented and contacts involving dynamic alteration of contacts among asperities are rigorously calculated. Using this approach, fracture alteration caused by deformation, re-arrangement and sliding of rough surfaces can be captured. Our comprehensive model is able to handle the computational challenges with accurate representation of intersections and shearing of fractures at the discrete fracture scale and rigorously treats contacts along rough fracture surfaces at the discontinuum asperity scale. With future development of three-dimensional (3D) geometric representation of discrete fracture networks in porous rock and contacts among multi-body systems, this model is promising as a basis of 3D fully coupled analysis of fractures at multiple scales, for advancing understanding and optimizing energy recovery and storage in fractured geological media.
Preservation of organic carbon in dolomitized Cambrian stromatolites and implications for microbial biosignatures in diagenetically replaced carbonate rock

Abstract Stromatolites have been a major focus in the search for ancient microbial life, however, the organic carbon biosignatures of dolomitized stromatolites have not yet been fully characterized or correlated with their dolomitizing conditions. Although dolomitization rarely preserves microbial morphology, the presence of organic carbon can provide valuable information for characterization of fossils' biogenicity, syngenicity, and indigeneity to their host rock. The Cambrian Allentown Formation in New Jersey, USA, is an excellent example of dolomitized stromatolites and thrombolites containing diagenetically modified microbial biosignatures. Based on XRD and EPMA data, the dolomite composition is typically stoichiometric, with varying degrees of cationic ordering. The outcrop underwent early dolomitization in a marginal-marine setting and later burial diagenesis resulting in multi-generational dolomite formation: (1) microspar dolomite formed by early diagenetic replacement at or near the surface, (2) zoned dolomite formed penecontemporaneously with the microspar phase as rhombohedral crystals by infilling primary pore spaces within the microspar matrix. The rhombic crystals continued to grow outward in alternating stages of Fe-enriched and -depleted fluids, which were preserved in zoned rims and revealed by cathodoluminescence, and (3) saddle dolomite formed during late stage deep burial with Fe- and Mn-rich fluids, and occurs as a void-filling, high-temperature phase. Organic carbon, characterized using confocal Raman microscopy, has an exclusive distribution within the microspar dolomite, and the D and G bands' characteristics reveal similar thermal alteration to the host rock, indicating that the mapped organic carbon is indigenous and syngenetic with the Cambrian carbonates. The findings presented in this study reveal organic matter found within microspar of various dolomitized facies deriving from different source pools of organic carbon. This study sheds light on biosignatures in secondary dolostones and may aid biosignature detection in older carbonate rocks on Earth and Mars.
Endothelial function and arterial stiffness in young adults with histories of chronic resistance activity

Endothelial dysfunction and arterial stiffness indicate vessel damage and are detectable before overt cardiovascular disease. Chronic cardiorespiratory endurance activity improves arterial endothelial function and stiffness. The influence of chronic resistance activity on these variables is less definitive and thus deserves attention. The primary aim of this investigation was to determine if endothelial dysfunction and arterial stiffness were present in apparently healthy young adults who chronically engage in resistance activity with minimal cardiorespiratory endurance activity. Investigators measured endothelial function as LnRHI and arterial stiffness as AI@75 using the EndoPAT-2000. Investigators measured upper-body muscular strength using a standardized one-repetition maximum (1-RM) bench press. The LnRHI and AI@75 between males and females were compared via an independent-samples t -test and Mann-Whitney U test, respectively. Correlations between 1-RM, bench press to body weight ratio, LnRHI, and AI@75 were evaluated via Pearson’s correlation. Males’ LnRHI was abnormal according to manufacturer standards and lower than females’ ( p = .005), but AI@75 was normal and similar for both sexes ( p = .22). The 1-RM and bench press to body weight ratio correlated negatively with LnRHI ( p = .03 and p = .01, respectively). The bench press to body weight ratio correlated negatively with AI@75 ( p = .03), and percentage body fat correlated positively with the AI@75 ( p = .003). Young adult males with considerable upper-body muscular strength due to chronic resistance activity, who complete minimal cardiorespiratory endurance activity, appear to have detectable signs of early endothelial dysfunction.
Emerging investigator series: local pH effects on carbon oxidation in capacitive deionization architectures

In this work, the effect of pH and potential is examined for the oxidation of carbon cloth electrodes used in capacitive deionization (CDI) processes. The degree of oxidation of the electrode surface, examined using the electrode's potential of zero charge (Epzc) and measured using chronoamperometry and cyclic voltammetry, is found to be strongly correlated to the pH of the solution at the interface. Local pH measurements are examined at anodes and cathodes in full CDI and membrane-assisted capacitive deionization (MCDI) cells at cell voltages ranging from 0.3–1.2 V. The cathode is shown to be basic under charging potentials while the anode is found to be acidic. This local pH is found to be highly transient during charging and discharging in CDI cells while the pH is found to be relatively static in the MCDI cells, maintaining a basic pH at the cathode and an acidic pH at the anode even when the cell is discharged. Ion exchange membranes (IEM) are found to have two functions: (1) limiting co-ion expulsion that results from specific ion adsorption and (2) limiting the effects of parasitic Faradaic reactions on the separation process by stabilizing the local pH thereby mitigating dissolved oxygen reduction at the cathode and lessening carbon oxidation at the anode. Performance comparisons including the salt adsorption capacity and charge efficiency are also compared for these systems.
Medical Education From a Theory-Practice-Philosophy Perspective.

Medical schooling, at least as structured in the United States and Canada, is commonly assembled intuitively or empirically to meet concrete goals. Despite a long history of scholarship in educatio...
The Irreversibility of Organ Injury

In the adult mammal, injury to the stroma is typically irreversible and leads to formation of nonphysiological scar tissue (repair). Every organ in the adult can be irreversibly injured, resulting in repair with scar formation. In certain organs injury is irreversible when it leads to damage of specific tissues while in others it becomes irreversible when the injury exceeds a critical size.
Initiation of Activation of a Preemergent Herbicide by a Novel Alkylsulfatase of Pseudomonas putida FLA.

The activation of the preemergent herbicide 2-(2,4-dichlorophenoxy)ethyl sulfate (Crag herbicide) is initiated by soil microorganisms that are presumed to act by removing the ester sulfate group via some type of sulfatase enzyme. An enrichment technique with the herbicide as the sole source of sulfur led to the isolation of several pure cultures that could produce 2-(2,4-dichlorophenoxy)ethanol from the herbicide. One of these, a strain of Pseudomonas putida, was particularly active. Polyacrylamide gel zymograms of extracts of cells grown on nutrient broth showed the presence of three secondary and three primary alkylsulfatases. One of the latter enzymes was active toward Crag herbicide as well as sodium dodecyl sulfate. Maximum activity was obtained in the late-stationary phase of growth, and enzyme yields were not affected by either the presence or the absence of the herbicide in the growth medium. The enzyme was purified 2,670-fold to homogeneity by a combination of streptomycin sulfate treatment, heat treatment, and column chromatography on DEAE-cellulose, Sephacryl 200-S, and butyl agarose. The pure enzyme was tetrameric (molecular weight, 295,000) and most active at pH 6.0. Saturation kinetics with inhibition by excess substrate were observed for Crag herbicide and octyl sulfate. 2-Butox-yethyl sulfate was a relatively poor substrate, and dodecyltriethoxy sulfate was not hydrolyzed at all. Enzymatic hydrolysis of each substrate in the presence of H218O led to incorporation of 18O exclusively into SO42− ions in all three cases. The Crag herbicide sulfatase therefore acts by cleaving the O-S bond of the C-O-S ester linkage, in contrast with other alkylsulfatases acting on long-chain alkyl sulfates.
Implications of cortical balanced excitation and inhibition, functional heterogeneity, and sparseness of neuronal activity in fMRI

Blood-oxygenation-level-dependent (BOLD) functional magnetic resonance imaging (fMRI) studies often report inconsistent findings, probably due to brain properties such as balanced excitation and inhibition and functional heterogeneity. These properties indicate that different neurons in the same voxels may show variable activities including concurrent activation and deactivation, that the relationships between BOLD signal and neural activity (i.e., neurovascular coupling) are complex, and that increased BOLD signal may reflect reduced deactivation, increased activation, or both. The traditional general-linear-model-based-analysis (GLM-BA) is a univariate approach, cannot separate different components of BOLD signal mixtures from the same voxels, and may contribute to inconsistent findings of fMRI. Spatial independent component analysis (sICA) is a multivariate approach, can separate the BOLD signal mixture from each voxel into different source signals and measure each separately, and thus may reconcile previous conflicting findings generated by GLM-BA. We propose that methods capable of separating mixed signals such as sICA should be regularly used for more accurately and completely extracting information embedded in fMRI datasets.
Abstract 15847: Excitation-Contraction Coupling and IP3-Dependent Ca Signaling in Atrial Myocytes From Normal and Failing Hearts

We studied excitation-contraction-coupling (ECC) and inositol-1,4,5-triphosphate (IP3) dependent Ca release in atrial myocytes from normal and heart failure (HF) rabbit hearts. Elementary Ca release events (Ca puffs) from IP3 receptors (IP3Rs) were detected in membrane-permeabilized myocytes after inhibition of ryanodine receptor mediated Ca sparks with tetracaine. Puff activity was induced by IP3 exposure and blocked by 2-aminoethoxydiphenyl borate (2APB), identifying their origin from IP3Rs. In normal myocytes puff activity was low and restricted to the cell periphery, whereas in HF myocytes their overall frequency was increased and puffs were more prominent in the cell center. In HF atrial myocytes, diastolic [Ca]i was increased and action potential (AP) induced Ca transients (CaTs) were larger in amplitude whereas no difference in sarcoplasmic reticulum Ca load was observed. Increased CaT amplitudes in HF myocytes were attenuated by 2APB or adenoviral expression of an IP3 sponge or 5’-phosphatase. Angiotensin II (AT) and photolytical release of caged IP3 increased diastolic [Ca]i in normal and HF myocytes whereas the effect was more pronounced in HF. The amplitude of CaTs was increased in the presence of AT or after IP3 uncaging in normal cells, however the opposite effect was observed in HF. The frequency of spontaneous Ca waves was higher in HF, and returned to normal levels after 2APB exposure. Nearly half of all Ca waves in normal cells, but
Cataclysmic Variables as Interacting Binary Stars

The periodical literature on cataclysmic variables (CVs) and closely related topics has grown rapidly in recent years. In the Astrophysical Journal alone, the number of papers published on this subject in 1982 was about 80, the rate having doubled in three years. The other major journals taken together yield a similar annual total. In view of this enormous burst of activity it is impossible to review the whole field in a few pages. Fortunately it is also not necessary to do so, for several excellent recent reviews of specific topics, as well as published conference proceedings, are available.
Penicillin-Binding Protein Imaging Probes

Penicillin-binding proteins (PBPs) are membrane-associated proteins involved in the biosynthesis of peptidoglycan (PG), the main component of bacterial cell walls. These proteins were discovered and named for their affinity to bind the β-lactam antibiotic penicillin. The importance of the PBPs has long been appreciated; however, the apparent functional redundancy of the ~5 to 15 proteins that most bacteria possess makes determination of their individual roles difficult. Existing techniques to study PBPs are not ideal because they do not directly visualize protein activity and can suffer from artifacts. Therefore, development of new methods for studying the roles of distinct PBPs in cell wall synthesis was compulsory. Due to penicillin's covalent mode of inhibition, fluorophore-conjugated analogs can be utilized to visualize PBP activity. Herein, we describe a general protocol to label and detect subsets of active PBPs in live, Gram-positive bacteria using fluorescent β-lactams.
Vitamin C supplementation in pregnancy--does it decrease rates of preterm birth? A systematic review.

Objective To assess the evidence available on the use of vitamin C supplementation greater than recommended dietary intake to reduce preterm birth rates. Study Design Systematic review of randomized controlled trials using vitamin C alone or with one other supplement other than iron. Trials must report preterm birth rates but can have other primary outcomes. Preterm birth is defined as birth at less than 37 weeks' gestational age for this review. Review focused on studies with populations representative of Organization for Economic Co-operation and Development countries. Results Inadequate level of evidence on the use of vitamin C alone to prevent preterm birth rates in low-risk populations based on one study. Three studies provided convincing evidence of no benefit in low-risk groups of use of vitamins C and E combined. Three studies provided adequate evidence of no benefit in high-risk groups of use of vitamins C and E combined. Conclusion The available evidence supports no benefit gained from using vitamin C to prevent preterm birth. Evidence does not support limiting use of vitamin C supplementation for other indications.