cssi/SciSciGPT-SciSciNet huggingface dataset:
Biofilm Formation on Natural Teeth and Dental Implants: What is the Difference?

Dental plaque is a milieu of microbes embedded within a polymeric layer of glycoproteins precipitated from the saliva onto tooth enamel, dental implants, cementum, and epithelium. This dental biofilm can extend below the gingival margin into the socket where the microorganisms are concealed from the bacteriostatic components in the saliva and the shearing forces exerted by chewing and normal brushing. Gingivitis and periodontal disease occurs when more virulent microbes colonize the subgingival pocket and evade eradication by the host defenses. A distinctive shift in microbial colonization is observed with the progression of disease highlighted by the expansion of gram negative and strictly anaerobic bacteria. Host response and inflammation meant to eliminate the microbial insult are counterproductive and generate a deeper pocket within the dental socket that permits the microbial access to the alveolar bone. Dental implants form another nidus for bacterial infection following surgery when the surface and socket are exposed to the oral environment. Dental implantation may be a direct consequence of periodontal disease; therefore the underlying microbial infection could threaten successful osseointegration of the implant if a microbial biofilm develops. Periodontal pockets and other oral niches, such as the mucosa and tonsils, are reservoirs for the microbial pathogens that initiate the inflammation of the marginal soft tissue around the dental implants that may lead to implant failure. Reduction in peri-implantitis rates are shown when patients delay implant surgery after tooth extraction and rigorous preoperative and postoperative antibiotic regiments as well as improved dental hygiene are incorporated into the post-operative treatment.
Material Flaw Populations and Component Strength Distributions in the Context of the Weibull Function

A clear relationship between the population of brittle-fracture controlling flaws generated in a manufactured material and the distribution of strengths in a group of selected components is established. Assumptions regarding the strength-flaw size relationship, the volume of the components, and the number in the group, are clarified and the contracting effects of component volume and truncating effects of group number on component strength empirical distribution functions highlighted. A simple analytical example is used to demonstrate the forward prediction of population → distribution and the more important reverse procedure of empirical strength distribution → underlying flaw population. Three experimental examples are given of the application of the relationships to state-of-the-art micro- and nano-scale strength distributions to experimentally determine flaw populations: two on etched microelectromechanical systems (MEMS) structures and one on native and oxidized silicon nanowires. In all examples, the minimum threshold strength and conjugate maximum flaw size are very well estimated and the complete flaw population, including the minimum flaw size, are very poorly estimated, although etching, bimodal, and oxidation effects were clearly discernible. The results suggest that the best use of strength distribution information for MEMS manufacturers and designers might be in estimation of the strength threshold.
Customer responses to frontline employee complaining in retail service environments: The role of perceived impropriety

Abstract Substantial research recognizes the importance of understanding employee-customer interactions in order to optimize the customer experience. While most retailing and services research focuses on frontline employees' handling of customer complaints, the present studies take an inverse approach by examining a relatively unexplored phenomenon: customers' perceptions of frontline employee complaining. First, a pilot study confirms two commonly overheard types of employee complaints - complaints about the company and customers. Next, Study 1 provides empirical support for the effects of overhearing employee complaining on relevant customer outcomes and identifies perceived impropriety as the mediating mechanism underlying these effects. The results of Study 2 indicate that soliciting customers' feedback about their experience attenuates the indirect effects of one type of employee complaint - complaints about the company. We conclude with a discussion of our findings and provide practical suggestions to retailers and service providers for reducing the harmful effects of overheard employee complaints.
Glucose-6-phosphate dehydrogenase deficiency increases cell adhesion molecules and activates human monocyte-endothelial cell adhesion: Protective role of l-cysteine

Glucose-6-phosphate dehydrogenase is a major enzyme that supplies the reducing agent nicotinamide adenine dinucleotide phosphate hydrogen (NADPH), which is required to recycle oxidized/glutathione disulfide (GSSH) to reduced glutathione (GSH). G6PD-deficient cells are susceptible to oxidative stress and a deficiency of GSH. Endothelial dysfunction is characterized by the loss of nitric oxide (NO) bioavailability, which regulates leukocyte adhesion to endothelium. G6PD-deficient endothelial cells (EC) demonstrate reduced expression of endothelial nitric oxide synthase (eNOS) and NO levels along with reduced GSH. Whether G6PD deficiency plays any role in EC dysfunction is unknown. The chronic inflammation commonly seen in those with metabolic syndrome, characterized by elevated levels of tumor necrosis factor (TNF) and monocyte chemoattractant protein 1 (MCP-1), provided an incentive for investigation of these cytokines as well. A GSH/G6PD-deficient model was created using human umbilical vein endothelial cells (HUVEC) treated with either buthionine sulfoximine (BSO), a pharmacological inhibitor of the rate-limiting enzyme of GSH biosynthesis (γ-glutamylcysteine synthetase), or with 6-aminonicotinamide (6-AN), an inhibitor of G6PD or G6PD siRNA. Normal and G6PD-deficient cells were also treated with pro-atherosclerotic stimuli such as high glucose, TNF, and MCP-1. After inhibiting or knocking down G6PD/GSH, the capacity of endothelial cells for monocyte recruitment was assessed by determining the expression of the adhesion molecules intercellular adhesion molecule 1 (ICAM-1) and vascular cell adhesion molecule 1 (VCAM-1), which was upregulated by G6PD deficiency and accompanied by the presence of the oxidative stress markers NADPH oxidase 4 (NOX4), inducible nitric oxide synthase (iNOS), and reactive oxygen species (ROS). Treatment with the inhibitors BSO and 6-AN caused increased levels of adhesion molecule mRNA and monocyte-EC adhesion. Following treatment with high glucose, G6PD-deficient cells showed an increase in levels of ICAM-1 and VCAM-1 mRNA, as well as monocyte-EC adherence, compared with results seen in control cells. Treatment with l-cysteine (a precursor of GSH) protected endothelial cells by increasing GSH and attenuating ROS, ICAM-1, VCAM-1, and monocyte-EC adhesion. These results suggest that G6PD/GSH deficiency plays a role in endothelial dysfunction and that supplementation with l-cysteine can restore GSH levels and reduce the EC activation markers in G6PD-deficient conditions.
Diagonal Earlobe Crease, a Marker of Coronary Artery Disease: A Case Report on Frank's Sign

There are various physical signs that can be used as a reliable tool to diagnose the subclinical stages of atherosclerosis, including corneal arcus, xanthelasma, and diagonal earlobe crease (DELC) or "Frank's sign". Bilateral diagonal earlobe crease has been positively correlated with coronary artery disease (CAD) and peripheral vascular disease (PVD). The presence of DELC has been identified as an independent variable for CAD. The exact etiology is unknown and the association between the presence of DELC and coronary artery disease (CAD) still remains controversial. We report a case of a patient with bilateral DELC who was found to have remarkable non-occlusive CAD on diagnostic coronary angiography.
The Impact of Chronic Obstructive Pulmonary Disease and Hospital Teaching Status on Mortality, Cost, and Length of Stay in Elective Total Hip Arthroplasty Patients.

Introduction Total hip arthroplasty (THA) is a frequently performed surgery. Chronic obstructive pulmonary disease (COPD) is one of the most prevalent diseases in the United States and has been associated with higher complications in many orthopedic surgeries. The purpose of this study was to examine the clinical and economic impacts of COPD on the mortality, cost, and length of stay of those undergoing THA and the effect of hospital teaching status on these outcomes. Methods This retrospective cohort study identified adult patients (≥18 years) utilizing information from the Healthcare Cost and Utilization Program Nationwide Inpatient Sample (NIS) from 2012 to 2014 undergoing elective THA using ICD-9 codes. Patients missing key clinical identifiers or those who did not undergo THA were excluded. Mortality, cost, and length of stay were assessed. The COPD cohort was further analyzed by hospital teaching status, including urban teaching, urban non-teaching, and rural. Results An adjusted total of 7,652 patients with COPD and 768,000 patients without COPD undergoing THA were identified. COPD was associated with higher mortality rates, longer lengths of stay, and total charges. In the COPD cohort, teaching status did affect outcomes. Between urban teaching hospitals and urban non-teaching, chronic conditions were significantly higher in urban teaching hospitals, yet total charges were lower. LOS was longer in rural hospitals, however, all other variables, including costs, were not significantly different as compared to urban teaching hospitals. Between urban non-teaching hospitals and rural hospitals, the number of chronic conditions and LOS were higher in rural hospitals, yet costs were significantly less. Age and mortality rates were not significantly different between different teaching statuses. Conclusion COPD has a significant effect on mortality, length of stay, and cost in patients undergoing THA. Additionally, teaching status seems to play an interesting role in these variables. Preoperative planning may help surgeons mitigate some of these risks associated with COPD. Further work on how LOS and costs are optimized with regards to teaching status should be done.
Vibrational Spectra of the Binary Fluorides of the Main Group Elements

Publisher Summary Vibrational spectroscopy is an important tool for the characterization of various chemical species. Valuable information regarding molecular structures, as well as intra- and intermolecular forces can be extracted from vibrational spectral data. Recent advances, such as the introduction of laser sources to Raman spectroscopy, the commercial availability of Fourier transform infrared spectrometers, and the continuing development and application of the matrix-isolation technique to a variety of chemical systems, have greatly enhanced the utility of vibrational spectroscopy to chemists. Inorganic fluorine compounds are of considerable interest and importance not only because fluorides of nearly all known elements, including some of the rare gases, have been synthesized, but because a number of these compounds are quite different from other halides. Consider, for example, compounds SF, and SF, and their chloroanalogs. The SF, is chemically a very inert and a very stable compound, whereas SF4, also quite stable, is quite reactive.
Comparing the Pragmatic Speech Profiles of Minimally Verbal and Verbally Fluent Individuals with Autism Spectrum Disorder

Although pragmatic speech impairments have been found across the autism spectrum, how these manifest in minimally verbal (MV) individuals with autism spectrum disorder (ASD) has not been studied. We compared the pragmatic speech profiles of MV (n = 50) and verbally fluent (VF) individuals with ASD (n = 50; 6–21 years-old) based on natural language sampling during the Autism Diagnostic Observation Schedule-2. MV individuals with ASD primarily used their speech to agree/acknowledge/disagree, respond to a question, and request. In contrast, the primary pragmatic function used by VF individuals was commenting. Out of the total non-echolalic speech, groups did not differ proportionally in labeling and response to questions. Findings highlight the importance of investigating multiple aspects of pragmatic communication across different conversational partners and contexts.
ACUTE CHANGES IN MITRAL ANNULAR DIMENSIONS ON 3D TRANSESOPHAGEAL ECHOCARDIOGRAPHY AFTER MITRACLIP TREATMENT OF MITRAL REGURGITATION: A PILOT STUDY

Transcatheter mitral valve repair(TMVr) with MitraClip(MC) is beneficial in selected patients with symptomatic severe mitral regurgitation(MR). We evaluate acute changes in mitral annular dimensions analyzed by 3D transesophageal echocardiography(TEE). 19 patients undergoing TMVr with MC had 3D TEE
Proactive Mediation in Plan-Based Narrative Environments

In interactive plan-based narrative environments, users' actions must be monitored to ensure that conditions necessary for the execution of narrative plans are not compromised. In the Zocalo system, management of user actions has been performed on a reactionary basis by a process called mediation. In this paper, we describe an extension to this approach, proactive mediation, which calculates responses to user input in an anticipatory manner. A proactive mediation module accepts as input a plan describing the actions being performed by the user (generated by a plan recognition system) and identifies portions of that plan that jeopardize the causal structure of the overall narrative. Once these portions are identified, proactive mediation generates modifications to the narrative plan structure that avoid the unwanted interaction between user and story. This extension to the original mediation algorithm provides more responses to a user's actions and generates responses that are tailored to the user's activity.
Convolutional Neural Networks Based Bengali Handwritten Character Recognition

With the increment of computation power, recognizing handwritten Character has become popular and significant improvement has been achieved for most of the major languages. But Bengali character recognition system is not well enough because of the presence of perplexing character and excessive cursive in its characters. Although several research works have been conducted for recognizing the Bengali characters, an efficient procedure is yet to discover. As the number of datasets is inadequate, most of these studies could not achieve a satisfactory level. So we propose here to train a Convolution Neural Network (CNN) and tune the parameters for better accuracy. This procedure is applied to CMATERDB 3.1.2 dataset with 15000.
The Effects of Residential Mobility on Criminal Persistence and Desistance during the Transition to Adulthood

Objectives:Prior research has documented that residential mobility has the potential to trigger both criminal persistence and desistance, with frequent moving often predicting persistence and long-...
Prehospital Disaster Triage Does Not Predict Pediatric Outcomes: Comparing the Criteria Outcomes Tool to Three Mass-Casualty Incident Triage Algorithms

Introduction: It remains unclear which mass-casualty incident (MCI) triage tool best predicts outcomes for child disaster victims. Study Objectives: The primary objective of this study was to compare triage outcomes of Simple Triage and Rapid Treatment (START), modified START, and CareFlight in pediatric patients to an outcomes-based gold standard using the Criteria Outcomes Tool (COT). The secondary outcomes were sensitivity, specificity, under-triage, over-triage, and overall accuracy at each level for each MCI triage algorithm. Methods: Singleton trauma patients under 16 years of age with complete prehospital, emergency department (ED), and in-patient data were identified in the 2007-2009 National Trauma Data Bank (NTDB). The COT outcomes and procedures were translated into ICD-9 procedure codes with added timing criteria. Gold standard triage levels were assigned using the COT based on outcomes, including mortality, injury type, admission to the hospital, and surgical procedures. Comparison triage levels were determined based on algorithmic depictions of the three MCI triage tools. Results: A total of 31,093 patients with complete data were identified from the NTDB. The COT was applied to these patients, and the breakdown of gold standard triage levels, based on their actual clinical outcomes, was: 17,333 (55.7%) GREEN; 11,587 (37.3%) YELLOW; 1,572 (5.1%) RED; and 601 (1.9%) BLACK. CareFlight had the best sensitivity for predicting COT outcomes for BLACK (83% [95% confidence interval, 80%-86%]) and GREEN patients (79% [95% CI, 79%-80%]) and the best specificity for RED patients (89% [95% CI, 89%-90%]). Conclusion: Among three prehospital MCI triage tools, CareFlight had the best performance for correlating with outcomes in the COT. Overall, none of three tools had good test characteristics for predicting pediatric patient needs for surgical procedures or hospital admission.
Bioinspired Smart Materials With Externally-Stimulated Switchable Adhesion

Living organisms have evolved, over billions of years, to develop specialized biostructures with switchable adhesion for various purposes including climbing, perching, preying, sensing, and protecting. According to adhesion mechanisms, switchable adhesives can be divided into three categories: mechanically-based adhesion, liquid-mediated adhesion, physically-actuated adhesion and chemically-enhanced adhesion. Mimicking these biostructures could create smart materials with switchable adhesion, appealing for many engineering applications in robotics, sensors, advanced drug-delivery, protein separation, etc. Progress has been made in developing bioinspired materials with switchable modulated by external stimuli such as electrical signal, magnetic field, light, temperature, pH value, etc. This review will be focused on new advance in biomimetic design and synthesis of the materials and devices with switchable adhesion. The underlying mechanisms, design principles, and future directions are discussed for the development of high-performance smart surfaces with switchable adhesion.
Whether 8 U.S.C. § 1252(g) Precludes the Exercise of Federal Jurisdiction over Claims Brought by Wrongfully Removed Noncitizens

Section 1252(g) of the Immigration and Nationality Act provides that “no court shall have jurisdiction to hear any cause or claim by or on behalf of any alien arising from the decision or action by the Attorney General to commence proceedings, adjudicate cases, or execute removal orders against any alien.” The Eighth and Ninth Circuits disagree about whether this provision precludes judicial review over claims brought by noncitizens who are wrongfully removed from the United States. This Comment advances four arguments for why § 1252(g) should be interpreted narrowly to allow federal jurisdiction over such claims by looking to Supreme Court precedent, legislative history, and public policy: First, Supreme Court precedent suggests that § 1252(g) may apply to only the Attorney General's discretionary decisions, and wrongful removal is never in the Attorney General's discretion. Second, precedent and legislative history support a narrow interpretation of the phrase "arising from" in § 1252(g). Third, the plain language of the statute indicates that § 1252(g) may not be implicated when the Attorney General wrongfully removes someone from the United States. Finally, interpreting the statute narrowly is the best normative outcome because it restrains improper executive action and prevents harm to noncitizens.
Thermal Residual Stress in Environmental Barrier Coated Silicon Nitride‐Modeled

When exposed to combustion environments containing moisture both un-reinforced and fiber reinforced silicon based ceramic materials tend to undergo surface recession. To avoid surface recession environmental barrier coating systems are required. However, due to differences in the elastic and thermal properties of the substrate and the environmental barrier coating, thermal residual stresses can be generated in the coated substrate. Depending on their magnitude and nature thermal residual stresses can have significant influence on the strength and fracture behavior of coated substrates. To determine the maximum residual stresses developed during deposition of the coatings, a finite element model (FEM) was developed. Using this model, the thermal residual stresses were predicted in silicon nitride substrates coated with three environmental coating systems namely barium strontium aluminum silicate (BSAS), rare earth mono silicate (REMS) and earth mono di-silicate (REDS). A parametric study was also conducted to determine the influence of coating layer thickness and material parameters on thermal residual stress. Results indicate that z-direction stresses in all three systems are small and negligible, but maximum in-plane stresses can be significant depending on the composition of the constituent layer and the distance from the substrate. The BSAS and REDS systems show much lower thermal residual stresses than REMS system. Parametric analysis indicates that in each system, the thermal residual stresses can be decreased with decreasing the modulus and thickness of the coating.
Studies on Adrenal Steroid Hydroxylases EXTRINSIC PROPERTIES OF THE OPTICAL ACTIVITY IN ADRENAL IRON-SULFUR PROTEIN (ADRENODOXIN)

Abstract Treatment of adrenal iron-sulfur protein (adrenodoxin) with urea and guanidine HCl results in a deterioration reaction that proceeds through at least two intermediate stages yielding the completely denaturated, colorless protein. The first transient state exhibits a circular dichroism maximum at 470 mµ which is shifted to a longer wave length than that of the native protein (440 mµ); at 470 mµ it has a much smaller ellipticity than the original protein at 440 mµ. The absorption spectrum of this first intermediate is almost identical with the native protein. The second transient state displays no Cotton effect and the optical absorption spectrum is similar to the native protein; the extinction coefficient at 414 mµ is about half that of the untreated protein. The deterioration process of spinach ferredoxin in the presence of urea and guanidine HCl resembles that of adrenal iron-sulfur protein. The reaction also proceeds through an intermediate state, giving rise to a circular dichroism maximum at 470 mµ. The results show that different kinetic profiles of optical activity and optical absorption are involved in the deterioration process of the chromophore in iron-sulfur proteins.
Renal Papillary Necrosis in Diabetic Patients

Cases of probable renal papillary necrosis (RPN) may have been described for centuries, but it was not until 1877 that RPN was actually identified as a distinct clinicopathological entity in a man who had prostatic hypertrophy, hydronephrosis and bilateral papillary necrosis [1,2]. Shortly thereafter, the first case of RPN in a diabetic was reported in a 60-year old diabetic woman who presented with gangrene of the left foot and at post-mortem had RPN [3]. The propensity of diabetic patients to papillary necrosis was first emphasized in 1937 [4,5]. From the outset a strong association was made between coexistent urinary tract infection in diabetics with RPN, and most of the initial reports considered RPN as a fulminant terminal complication of severe acute pyelonephritis in diabetic patients [6–9]. Subsequent reports described a more indolent chronic form of RPN in diabetics, generally in those with recurrent episodes of urinary tract infection, but not necessarily with coexistent pyelonephritis [10–12].
Histidine regulation in Salmonella typhimurium. XVI. A sensitive radiochemical assay for histidinol dehydrogenase.

Abstract A sensitive radiochemical assay for measurement of histidinol dehydrogenase is presented. The method is based upon separation of the product of the reaction. [14C]histidine, from the substrate, [14C]histidinol, on small Dowex 50 columns. The assay can be performed on cell extracts or on toluenized cells and is approximately 100 times more sensitive than previously reported assays for this enzyme. [14C]histidinol is obtained in high yields through conversion of uniformly labeled 14C-glucose by a strain of Salmonella typhimurium derepressed for the histidine operon and blocked at the histidinol dehydrogenase step. Accumulated [14C]histidinol is purified from the culture supernatant by ion-exchange chromatography. This sensitive assay has facilitated measurement of reduced levels of histidine operon expression in promoter mutants, and has been adapted for study of histidine operon regulation in a cell free protein synthesizing system.
Explaining the size of the public sector

This paper aims at providing an explanation for the size of the public sector based on the idea of “social insurance”. The main assumption made is that the public sector is less efficient but also less volatile than the private sector. The “demand-driven” level of the public sector that is derived as the one that maximizes the utility of the representative employed consumer depends positively on the variance of private output. An increase in the size of the public sector has a positive effect on expected employment and a negative effect on expected consumption. The size of the public sector set by the government which maximizes the probability of being re-elected will be higher than the “demand-driven” level if voters' preferences for employment is higher than the consumption loss associated with public employment.
Racial Discrimination and Human Rights in the Global Context: The International Convention on the Elimination of all Forms of Discrimination

This essay will discuss racism and racial discrimination by locating them within a context of international human rights. It is argued that conceptually racism and racial discrimination within an international human rights paradigm sharpens our understanding of these concepts from both a global and regional vantage point. The main idea is to provide a thematic and procedural overview of key international human rights instruments that address racial discrimination. It will situate racial discrimination in the context of international human rights and provide a critical discussion focused on the International Convention on the Elimination of All forms of Racial Discrimination (ICERD) and other human rights instruments that address racial discrimination.
Studies on Squalene Epoxidase of Rat Liver

Abstract Rat liver microsomes previously heated to 50° for 5 min accumulate 2,3-oxidosqualene on incubation with squalene. Squalene epoxidase activity can be assayed either with squalene and heated microsomes or with 10,11-dihydrosqualene and intact microsomes. In common with other monooxygenases, the epoxidase requires TPNH and molecular oxygen. Both a soluble fraction of rat liver and microsomes are necessary for enzyme activity. Carbon monoxide or potassium cyanide fail to inhibit squalene epoxidation.
Note on the nature of the transition between a system in an equilibrium state and a system in a non-equilibrium state (and vice-versa)

The transition from a non-equilibrium state to an equilibrium state is characterized not only by the disappearance of the entropy production, but mainly by the disappearance of the organized currents, due to the gradients present in a non-equilibrium system. Their disappearance is necessary to obtain maximum entropy in the equilibrium state.
Green capital and social reproduction within families practising voluntary simplicity in the US

In this paper, we examine how parents in the US who practise voluntary simplicity enact family and social reproduction. Two key findings emerged. First, adult simplifiers in our study typically grew up within families that practised voluntary simplicity or frugality and transmit these consumption patterns to their own children. Second, simplifiers often struggle with other family members, friends and society over issues related to the tensions that emerge as they seek to simplify their lives while at the same time raising children who will not be ‘shunned’ by a mainstream, consumption-focused society. We conclude that parents who voluntarily simplify are able to maintain their social class status through redefining what it means to be middle class through the creation and utilization of ‘green capital’.
Kinetic assembling of the biologically active secondary structure for CAR, the target sequence for the Rev protein of HIV-1

We predict the metastable secondary structure for the CAR (cis anti-repressor sequence) which is active in the regulation of the interaction with the Rev protein of HIV-1. We prove that the active structure sustained between nts 7364 and 7559 of the env RNA is the most probable metastable structure whose formation is kinetically governed and not thermodynamically determined. The structure is obtained by means of a Monte Carlo simulation which computes refolding events which occur as the CAR portion of the viral RNA is being assembled. Thus, the regulatory role of the secondary structure is determined as soon as the new RNA has been synthesized and it is preserved for further recognition by the Rev protein. In analogy with previous work by the author, it is shown that the destabilization by site-directed mutagenesis of the secondary structure for a non-chain-specific recognition site enhances the Rev response.
Individual-difference predictors of felt stress among academics seriously considering career change

Abstract This study tested a model of individual-difference predictors of felt stress among a sample of 98 liberal arts Ph Ds seriously considering leaving academia for another field. Results of the mail questionnaire study supported predictions that felt stress was positively correlated with the perceived influence of lack of opportunity in academia on the career-change decision and negatively correlated with self-esteem, internal locus of control, and being currently married. The individual-difference variables together explained a substantially larger proportion of the variance in felt stress than did the perceived influence of lack of opportunity. Contrary to prediction, none of the individual differences moderated either the form or the degree of relationship between felt stress and the influence of lack of opportunity.
Bilingualism Matters: One Size Does Not Fit All.

The articles in this special issue provide a complex picture of acquisition in bilinguals in which the factors that contribute to patterns of performance in bilingual children’s two languages are m...
Life, geology and snowball Earth

According to the 'snowball Earth' hypothesis, a series of global glaciations occurred 750–580 million years ago, each lasting for millions of years and ending in a scorching heat caused by an extreme enrichment of atmospheric greenhouse gases. Hyde et al.1 have used climate models to simulate this global glaciation, finding in one case an alternative climate scenario in which a partially frozen Earth has ice-free oceans equatorward of 25° latitude. We do not believe that this 'slushball' Earth is consistent with the most striking geological and palaeomagnetic observations explained by the snowball Earth hypothesis.
Beta-Blockers in Pediatric Hypertrophic Cardiomyopathies

UNLABELLED Congestive cardiac failure accounts for 36% of childhood deaths in hypertrophic cardiomyopathy, and in infants with heart failure symptoms before two years of age, the mortality is extremely high unless treatment with beta-receptor antagonists is instituted. The mechanism of heart failure is not systolic dysfunction, but rather extreme diastolic dysfunction leading to high filling pressures. Risk factors for development of heart failure are a generalized pattern of hypertrophy with a left ventricular posterior wall-to- cavity ratio >0.30, the presence of left ventricular outflow tract obstruction at rest, and the co-existence of syndromes in the Noonan/Leopard/Costello spectrum. The 5-year survival of high-risk patients is improved from 54% to 93% by high-dose beta-blocker therapy (>4.5 mg/kg/day propranolol). The mechanism of the beneficial effect of beta-blockers is to improve diastolic function by lengthening of diastole, reducing outflow-obstruction, and inducing a beneficial remodelling resulting in a larger left ventricular cavity, and improved stroke volume. Hypertrophic cardiomyopathy is associated with increased activity of cardiac sympathetic nerves, and infants in heart failure with hypertrophic cardiomyopathy show signs of extreme sympathetic over-activity, and require exceptionally high doses of beta-blockers to achieve effective beta-blockade as judged by 24 h Holter recordings, often 8-24 mg/kg/day of propranolol or equivalent. CONCLUSION Beta-blocker therapy is without doubt the treatment of choice for patients with heart failure caused by hypertrophic cardiomyopathy, but the dose needs to carefully titrated on an individual basis for maximum benefit, and the dose required is surprisingly large in infants with heart failure due to hypertrophic cardiomyopathy.
Temperature Dependence of Dissociative Recombination and Molecular-Ion Formation in He, Ne, and Ar Plasmas

Recombination-dominated decaying plasmas in He, Ne, and Ar gases are produced in a discharge tube energized with a capacitor bank capable of delivering 3\ifmmode\times\else\texttimes\fi{}${10}^{3}$ J at 20 kV. The electron temperature, atom temperature, and electron number density as a function of time are measured by using a triple probe, a thin-film thermometer, and the triple probe and microwave apparatus, respectively. The atomic- and molecular-ion number densities are monitored by using a mass spectrometer. The electron-temperature dependence of the dissociative recombination coefficient ${\ensuremath{\alpha}}_{2}$, and the atom-temperature dependence of the molecularion formation coefficient $\ensuremath{\gamma}$ are calculated. The results indicate the following: (1) the electron-temperature dependence and absolute value of ${\ensuremath{\alpha}}_{2}$ are both affected by the atom temperature of the plasma; a simplified physical model is proposed to explain this variation of dependence; the previous controversial experimental results published in the literature on this subject can be understood with the use of this physical model; and (2) the atom-temperature dependence of $\ensuremath{\gamma}$ agrees with theoretical expectations.
On the comparative efficacy of memories and expectancies as cues for choice behavior in pigeons

Abstract The same reliable color cues were equally available to different groups of pigeons trained on a delayed conditional simultaneous visual discrimination task. However, for different groups, prechoice and postchoice food or no-food events were programmed in such a way that, theoretically, memories of these events, expectancies of them, both, or neither could also serve as reliable cues for choice. In the case where both prechoice and postchoice food/no-food events were correlated with correct choices, two ways of correlating the prechoice and postchoice events with one another were examined. For synergism subjects, when the prechoice event was food, the postchoice event was also food, and when the prechoice event was no food, the postchoice event was no food; therefore, on a given trial, the operative memory and expectancy were of the same event. For antagonism subjects, when the prechoice event was food, the postchoice event was no food, and vice versa; thus, for these subjects, the memory and expectancy active on a given trial were of opposite events. Expectancies were found to exert significantly greater control over choice behavior than memories. Moreover, antagonism subjects chose significantly less accurately than synergism subjects or than an expectancy only group. A follow-up experiment confirmed this effect. The relevance of these results to various models of memory and expectancy was addressed.
Outcome of pulmonary vein isolation ablation for paroxysmal atrial fibrillation: predictive role of left atrial mechanical dyssynchrony by speckle tracking echocardiography

Although few clinical variables have been associated with recurrence of atrial fibrillation (AF) after pulmonary vein isolation (PVI) the role of left atrial (LA) mechanical function in the outcome of catheter ablation of AF is not adequately defined. The aim of our study was to determine whether LA mechanical dyssynchrony as evaluated by speckle tracking echocardiography can predict outcome of PVI ablation procedure in patients with paroxysmal AF. Twenty-five patients (age 58 ± 11 years, [mean ± standard deviation], 17 males) with paroxysmal AF who met specific enrollment criteria pertaining to clinical presentation and follow-up, assessment of LA mechanical dyssynchrony, and strategy of catheter ablation procedure were enrolled. For LA mechanical dyssynchrony assessment, the time to peak longitudinal strain (TPk) in opposing walls in the midportion of the LA walls at peak atrial contraction in standard two- and four-chamber echocardiographic views by vector velocity imaging (VVI) was measured. Outcome of PVI procedure, whether no recurrence (NR) or AF recurrence (AFR) after 3 months of post-procedural blanking period, was evaluated based on AF-related symptoms and documentation of AF by electrocardiogram, continuous 24-h Holter, and intermittent event monitor recordings. During a follow-up period of 20.3 ± 8.6 months, 18 out of 25 (72 %) patients had no recurrence (NR group), and 7 out of 25 (28 %) patients had recurrence of AF (AFR group). Significant gender difference was observed in terms of outcome such that all AFR patients were men and no woman had recurrence of AF. Between the NR and AFR groups, neither the left atrial diameter, 4.0 ± 0.3 and 4.2 ± 0.2 cm, respectively (p = 0.2), nor the left atrial volume indexes, 45 ± 15 and 48 ± 20 ml/m2, respectively (p = 0.56), were statistically significantly different. For LA mechanical function, compared to the patients in NR group who had maximum opposing wall TPk delay of 39.9 ± 12.0 ms, those in the AFR group demonstrated significantly more LA mechanical dyssynchrony with maximum opposing wall TPk delay of 64.4 ± 17.0 ms prior to ablation (p = 0.007). Using receiver operative characteristic analyses of the data that had an area under the curve of 0.865, we identified a maximum opposing wall delay cutoff value of 51 ms which predicted AF recurrence with sensitivity and specificity values of 89 and 72 %, respectively (p = 0.005). Speckle tracking strain analysis echocardiography can evaluate the LA mechanical dyssynchrony quantitatively. The severity of LA mechanical dyssynchrony by VVI can predict the outcome of PVI catheter ablation for paroxysmal AF.
Distribution of hydrothermally altered rocks in the Reko Diq, Pakistan mineralized area based on spectral analysis of ASTER data

Abstract The Reko Diq, Pakistan mineralized study area, approximately 10 km in diameter, is underlain by a central zone of hydrothermally altered rocks associated with Cu–Au mineralization. The surrounding country rocks are a variable mixture of unaltered volcanic rocks, fluvial deposits, and eolian quartz sand. Analysis of 15-band Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data of the study area, aided by laboratory spectral reflectance and spectral emittance measurements of field samples, shows that phyllically altered rocks are laterally extensive, and contain localized areas of argillically altered rocks. In the visible through shortwave-infrared (VNIR + SWIR) phyllically altered rocks are characterized by Al–OH absorption in ASTER band 6 because of molecular vibrations in muscovite, whereas argillically altered rocks have an absorption feature in band 5 resulting from alunite. Propylitically altered rocks form a peripheral zone and are present in scattered exposures within the main altered area. Chlorite and muscovite cause distinctive absorption features at 2.33 and 2.20 μm, respectively, although less intense 2.33 μm absorption is also present in image spectra of country rocks. Important complementary lithologic information was derived by analysis of the spectral emittance data in the 5 thermal-infrared (TIR) bands. Silicified rocks were not distinguished in the 9 VNIR + SWIR bands because of the lack of diagnostic spectral absorption features in quartz in this wavelength region. Quartz-bearing surficial deposits, as well as hydrothermally silicified rocks, were mapped in the TIR bands by using a band 13/band 12 ratio image, which is sensitive to the intensity of the quartz reststrahlen feature. Improved distinction between the quartzose surficial deposits and silicified bedrock was achieved by using matched-filter processing with TIR image spectra for reference.
Cladding index engineering of the photonic properties of single-mode photonic crystal devices

In an effort to engineer photonic crystal slab (PCS) devices that operate within a single slab-mode regime, the effect of increased cladding index was studied using FDTD simulation. It is known that while increased cladding index forces the light-cone to constrict in frequency, the single mode condition eases allowing for the use of thicker slabs that remain single-mode. This study shows that the behavior of the photonic band gap is similar to that of the light-cone, sweeping lower in frequency, and even widening in some cases, as cladding index increases. Band gap behavior for both even and odd polarizations over thicknesses from d/a = 0.2 to 0.6 and cladding indices from 1 to 2.5 were studied in efforts to design a single-mode, polarization insensitive, complete band gap. When graphically overlaid, the light-cone, single-mode condition, and transmission spectra represent an enabling reference for the design of realizable structures. For device applications where modal dispersion is detrimental or single mode operation is necessary, a paradigm shift away from air-bridge devices is shown to be essential as single-mode structures of this type demand slab thicknesses far too thin for adequate band gap engineering.
Terrain analysis of the Racetrack Basin and the sliding rocks of Death Valley

Abstract The Racetrack Playa's unusual surface features known as sliding rocks have been the subject of an ongoing debate and several mapping projects for half a century, although the causative mechanism remains unresolved. Clasts ranging in volume from large pebbles to medium boulders have, unwitnessed, maneuvered around the nearly flat dry lake over considerable distances. The controversy has persisted partly because eyewitness accounts of the phenomenon continue to be lacking, and the earlier mapping missions were limited in method and geographic range. In July 1996, we generated the first complete map of all observed sliding rock trails by submeter differential Global Positioning System (DGPS) mapping technology. The resulting map shows 162 sliding rocks and associated trails to an accuracy of approximately 30 cm. Although anemometer data are not available in the Racetrack wilderness, wind is clearly a catalyst for sliding rock activity; an inferred wind rose was constructed from DGPS trail segment data. When the entire trail network is examined in plan, some patterns emerge, although other (perhaps expected relations) remain elusive: terrain analysis of the surrounding topography demonstrates that the length and morphology of trails are more closely related to where rocks rested at the onset of motion than to any physical attribute of the rocks themselves. Follow-up surveys in May 1998, May 1999, August 1999, and November 1999 revealed little modification of the July, 1996 sliding rock configuration. Only four rocks were repositioned during the El Nino winter of 1997–1998, suggesting that activity may not be restricted to winter storms.
Impact of varying degrees of renal dysfunction on transcatheter and surgical aortic valve replacement

Background Renal impairment portends adverse outcomes in patients undergoing valvular heart surgery. The relationship between renal dysfunction in patients undergoing transcatheter aortic valve replacement (TAVR) is incompletely understood. Methods A retrospective review of 1336 patients undergoing surgical aortic valve replacement (SAVR; 2002-2012) and 321 patients undergoing TAVR (2007-2012) was performed. Patients were divided into 3 glomerular filtration rate (GFR) groups: GFR greater than 60 mL/min, GFR 31 to 60 mL/min, and GFR 30 mL/min or less. Logistic and linear regression analysis was performed to estimate the TAVR effect on outcomes. Risk adjustments were made using the Society for Thoracic Surgeons (STS) predicted risk of mortality (PROM). Results TAVR patients were older (82 vs 65 years; P P P = .23), and had a higher STS PROM (11.9% vs 4.6%; P P = .60), a result that marginally favors TAVR after risk adjustment (adjusted odds ratio = .52, P = .06). In SAVR patients, worsening preoperative renal failure was associated with increased in-hospital mortality ( P = .004) and hospital ( P P P = .78) and hospital ( P P = .88) lengths of stay in TAVR patients. Conclusions Worsening renal function was associated with increased in-hospital mortality, hospital length of stay, and ICU length of stay in SAVR patients, but not in TAVR patients. This unexpected finding may have important clinical implications in patients with aortic stenosis and preoperative renal dysfunction.
The power of tests for equivalent ARMA models: The implications for practitioners

Analysts frequently find it convenient to use the same ARMA model to make forecasts for multiple time series. The trick is to know when it is safe to assume that multiple series are generated by the same underlying process. Although several authors have developed statistical procedures for testing whether two models are equivalent, no one has shown how to determine the power of these tests. This paper shows how to determine the power of the most general test for equivalent ARMA models. It also shows how to quantify the effect of model misspecification errors on the accuracy of the forecast. An illustrative example and flowchart are then used to show how calculating the power of the test can enable the practitioner to safeguard against a serious degradation in the accuracy of the forecast.
Synthesis and characterization of magnesium and zinc complexes of 1,4,7-triazacyclononane- N -acetate. Potential models for the active site of RuBisCo

Abstract Reaction of the tetradentate pendant-arm macrocycle 1,4,7-triazacyclononane-N-acetate (L) with Zn(O3SCF3)2 or Mg(O3SCF3)2 in alcohol produces the six-coordinate complexes [ZnL(H2O)]O3SCF3·C2H5OH (1) and [MgL(H2O)2]O3SCF3 (2). Compounds 1 and 2 were characterized by single-crystal X-ray crystallography. The complex cation of 1 forms a polymeric chain with zinc centers bridged in a syn, anti fashion by acetate pendant arms. The complex cation of 2 is mononuclear, with two adjacent coordination sites on magnesium occupied by water molecules. These labile coordination sites may provide a binding site for activation of substrates in functional modeling of magnesium enzymes such as RuBisCo. 1H and 13C NMR spectroscopy demonstrates that L remains bound to magnesium in methanol solution. Crystal data: 1, orthorhombic, space group P212121, a=9.0536(7), b=14.3750(11), c=14.4741(11) A, V=1883.7(2) A3, Z=4, R=0.041; 2, orthorhombic, space group P212121, a=8.5949(3), b=13.9694(4), c=14.0076(5) A, V=1681.83(10) A3, Z=4, R=0.0248.