cssi/SciSciGPT-SciSciNet huggingface dataset:
Specificity of a lipase fromGeotrichum candidum forcis -octadecenoic acid

A lipase fromGeotrichum candidum released mostly oleic acid from glyceryl 1-elaidate-2,3-dioleate and very littletrans fatty acid from margarine. When cod liver, Macadamia nut, peanut and safflower oils were substrates, the oleic acid content of the free acids was always in excess of the amount of the acid in the intact triglycerides. Congo palm oil was digested by bothG. candidum and pancreatic lipases and the fatty acid compositions of the products of hydrolysis compared. The results obtained with the aid ofG. candidum lipase tend to substantiate existence of some of the triglyceride isomers predicted from pancreatic lipase data.
Quality System Management and Education in Service Environments

Service quality is widely recognized as a core construct of services management. Effective service quality management, however, requires integration both across organizational units and the functional areas of a corporation. Using the Gaps Model of Service Quality, this paper articulates numerous quality challenges of large, multi-unit organizations, including measurement, service design, service delivery, and marketing communications. Meeting these challenges requires effective integration of various business disciplines, particularly marketing, human resource management, accounting, and information systems management. The paper concludes by relaying the challenges experienced in teaching this integration in service operations and marketing courses.
Abstinence-Only: Are You Not Working the Program or Is the Program Not Working for You?

Low retention rates are common in substance use treatment programs. The dominant model of service delivery in the United States is abstinence-only, a high-threshold service delivery model requiring...
Genetic analyses reveal cryptic introgression in secretive marsh bird populations.

Hybridization is common in bird populations but can be challenging for management, especially if one of the two parent species is of greater conservation concern than the other. King rails (Rallus elegans) and clapper rails (R. crepitans) are two marsh bird species with similar morphologies, behaviors, and overlapping distributions. The two species are found along a salinity gradient with the king rail in freshwater marshes and the clapper in estuarine marshes. However, this separation is not absolute; they are occasionally sympatric, and there are reports of interbreeding. In Virginia, USA, both king and clapper rails are identified by the state as Species of Greater Conservation Need, although clappers are thought to be more abundant and king rails have a higher priority ranking. We used a mitochondrial DNA marker and 13 diagnostic nuclear single nucleotide polymorphisms (SNPs) to identify species, classify the degree of introgression, and explore the evolutionary history of introgression in two putative clapper rail focal populations along a salinity gradient in coastal Virginia. Genetic analyses revealed cryptic introgression with site-specific rates of admixture. We identified a pattern of introgression where clapper rail alleles predominate in brackish marshes. These results suggest clapper rails may be displacing king rails in Virginia coastal waterways, most likely as a result of ecological selection. As introgression can result in various outcomes from outbreeding depression to local adaptation, continued monitoring of these populations would allow further exploration of hybrid fitness and inform conservation management.
QuickSketch: Building 3D Representations in Unknown Environments Using Crowdsourcing

Disaster and emergency response operations require rapid situational assessment of the affected area for timely and efficient rescue operations. A 3D map, collected after a disaster, can provide such awareness, but constructing this map quickly is a significant challenge. In this paper, we explore the design of a capability called QuickSketch that rapidly builds 3D representations of an unknown environment using crowdsourcing. QuickSketch employs multiple vehicles equipped with 3D sensors (stereo cameras) to explore different areas of an unknown territory and then combines 3D data from all the vehicles to build a single 3D map. QuickSketch annotates the 3D map with important landmarks and enables rapid contextualization of visual intelligence (photos) received from first responders and disaster victims to guarantee timely backup and rescue operations. Our evaluation results show that QuickSketch can stitch a 3D map for a large campus with sub-meter mapping accuracy under certain conditions, position landmarks an order of magnitude more accurately than other image matching techniques, and contextualize visual intelligence accurately.
Comparing acoustic and articulatory targets in short-term visual feedback training of non-native vowels

Theories of speech production aim to explain how talkers express abstract linguistic forms as audible events that are intelligible to both speaker and listener. The relationship among planned units of speech, their articulatory implementation, and their acoustic consequences is thus a key issue in speech research. The work reported here is part of a larger project designed to investigate the effects of visual acoustic and visual articulatory feedback on second language (L2) learners’ production and perception of non-native speech sounds. L2 talkers from a variety of language backgrounds practiced producing an English vowel, /ae/, while receiving visual feedback on either (1) first and second formant frequencies, provided by a real-time spectrographic display, or (2) tongue back position, shown using a talker-driven tongue avatar. Kinematic data were recorded using an electromagnetic articulograph (EMA) system that tracked tongue midline and lateral movement during vowel productions. Pronunciation accuracy was analyzed by calculating acoustic and kinematic Mahalanobis distances between L2 productions and target (native talker) exemplars. Initial analyses of a single subject’s data showed that both types of visual feedback training improved pronunciation, suggesting that both acoustic and articulatory information are recruited during vowel production.
Investigation of an experimental infection model of equine coronavirus in adult horses

Background Equine coronavirus (ECoV) is a recently reported enteric disease of adult horses. Natural infection by ECoV has been reported in adult horses worldwide, whereas experimental infection has only been reported in juvenile horses. An experimental infection model is needed to study the clinical presentation, laboratory abnormalities, and pathophysiological changes associated with ECoV. Objectives To investigate the clinical, hematologic, molecular, and serological features of adult horses experimentally infected with ECoV. Animals Eight adult horses. Methods Four horses were intragastrically infected with fecal material containing 109 genome equivalents of ECoV. Four additional horses were exposed daily to the feces from the experimentally-infected horses. Monitoring included physical examinations, as well as daily nasal swab, whole blood, and fecal collection for molecular detection of ECoV. Blood was collected every other day for hematologic analysis and weekly for serologic analysis. Results All 8 horses shed ECoV in feces. Six of the 8 horses (75%) exhibited mild, clinical disease with soft, formed manure; 1 horse exhibited transient pyrexia. All horses maintained total white cell counts within normal limits, but 3 horses developed transient lymphopenia. No statistically significant differences (P = .20) were observed in quantity of fecal shedding of ECoV between the 2 groups. Conclusions and clinical importance Experimental infection of adult horses with ECoV was associated with mild and self-limiting clinical signs, transient lymphopenia, and fecal shedding of ECoV, which mimics natural infection. No differences between experimentally-infected horses and horses exposed to ECoV-containing feces were identified. Results of our study support a fecal-oral route of transmission.
Using Students' Assessment Mistakes and Learning Deficits to Enhance Motivation and Learning

Being wrong is an integral part of the assessment process, and understanding how to learn from those mistakes, errors, and misconceptions helps educators and students get the most from their learning experience. In this practical volume, James H. McMillan shows why being wrong (sometimes) is an essential part of effective learning and how it can be used by teachers to motivate students and help develop positive achievement-related dispositions. The six concise chapters of Using Students’ Assessment Mistakes and Learning Deficits to Enhance Motivation and Learning show how mistakes affect students’ engagement, self-regulation, and knowledge, and how teachers can most effectively contextualize supposed failures to help students grow.
Long-term outcomes of ultrashort bowel syndrome due to malrotation with midgut volvulus managed at an interdisciplinary pediatric intestinal rehabilitation center

Abstract Purpose The purpose of this study was to describe long-term outcomes of pediatric-onset ultrashort bowel syndrome owing to midgut volvulus managed at an interdisciplinary intestinal rehabilitation center. Methods Patients with a history of malrotation and pediatric-onset midgut volvulus causing extensive bowel loss ( Results Twenty-three patients had midgut volvulus at age 1 (0–21) day leading to 9 (8–12) percent predicted residual bowel length. Eight (35%) had gastroschisis. Follow-up was 8.5 (6.6–12.2) years from volvulus. Five (22%) patients underwent intestinal/multivisceral transplantation, and all achieved enteral autonomy. Eighteen (78%) patients remained transplant-free, 7 of whom achieved enteral autonomy after 718 (682–1030) days of parenteral nutrition. Transplant-free enteral autonomy was achieved by 0/6 patients with gastroschisis, compared to 7/12 without gastroschisis (p = 0.04). For the overall group, 18 (78%) patients had small bowel bacterial overgrowth, and 7 manifested symptomatic D-lactic acidosis. We observed 2 mortalities, one awaiting transplant and one 4 years following transplantation. Conclusion Midgut volvulus owing to malrotation with extensive bowel loss is associated with favorable long-term survival. Transplant-free enteral autonomy may be feasible, particularly in the absence of gastroschisis. Type of study Prognosis study. Level of evidence IIb, retrospective cohort study.
Medicare expenditures attributable to dementia.

Objective To estimate dementia's incremental cost to the traditional Medicare program. Data sources Health and Retirement Study (HRS) survey-linked Medicare part A and B claims from 1991 to 2012. Study design We compared Medicare expenditures for 60 months following a claims-based dementia diagnosis to those for a randomly selected, matched comparison group. Data collection/extraction methods We used a cost estimator that accounts for differential survival between individuals with and without dementia and decomposes incremental costs into survival and cost intensity components. Principal findings Dementia's five-year incremental cost to the traditional Medicare program is approximately $15 700 per patient, nearly half of which is incurred in the first year after diagnosis. Shorter survival with dementia mitigates the incremental cost by about $2650. Increased costs for individuals with dementia were driven by more intensive use of Medicare part A covered services. The incremental cost of dementia was about $7850 higher for females than for males because of sex-specific differential mortality associated with dementia. Conclusions Dementia's cost to the traditional Medicare program is significant. Interventions that target early identification of dementia and preventable inpatient and post-acute care services could produce substantial savings.
Diastolic Dysfunction and Heart Failure With Preserved Ejection Fraction: Understanding Mechanisms by Using Noninvasive Methods.

AbstractResearch in the last decade has substantially advanced our understanding of the pathophysiology of heart failure with preserved ejection fraction (HFpEF). However, treatment options remain ...
Studying software metrics based on real-world software systems

Software metrics are the measurement of a software product and the corresponding software development process. They are very useful for improving software quality and productivity by quantitatively measuring the models of a software development process. In this paper, we introduce a project that can help students investigate software metrics with respect to software quality, and recognize the power of software metrics. The purpose of this project is to discover the patterns that classify software modules into low-quality and high-quality by using data associated with several NASA software systems. These patterns can help managers identify low-quality modules in similar software projects. As a result, cost-effective strategies can be deployed to assist with the success of a software project.
Secondary single-cell transcriptomic analysis reveals common molecular signatures of cerebrovascular injury between traumatic brain injury and aging

Cerebrovascular injury is a common pathological feature of a spectrum of neurological disorders including traumatic brain injury (TBI), stroke, Alzheimer's disease (AD), as well as aging. Vascular manifestations among these conditions are similar indeed, including the breakdown of the blood-brain barrier (BBB). However, whether there is a common molecular mechanism underlying the vascular changes among these conditions remains elusive. Here, we report secondary transcriptomic analysis on cerebrovascular cells based single-cell RNA-seq datasets of mouse models of mild TBI and aging, with a focus on endothelial cells and pericytes. We identify several molecular signatures commonly found between mTBI and aging vasculature, including Adamts1, Rpl23a, Tmem252, Car4, Serpine2, and Ndnf in endothelial cells, and Rps29 and Sepp1 in pericytes. These markers may represent the shared endophenotype of microvascular injury and be considered as cerebrovascular injury responsive genes. Additionally, pathway analysis on differentially expressed genes demonstrated alterations in common pathways between mTBI and aging, including vascular development and extracellular matrix pathways in endothelial cells. Hence, our analysis suggests that cerebrovascular injury triggered by different neurological conditions may share common molecular signatures, which may only be detected at the single-cell transcriptome level.
Image Transformation and CNNs: A Strategy for Encoding Human Locomotor Intent for Autonomous Wearable Robots

Wearable robots have the potential to improve the lives of countless individuals; however, challenges associated with controlling these systems must be addressed before they can reach their full potential. Modern control strategies for wearable robots are predicated on activity-specific implementations, and testing is usually limited to a single, fixed activity within the laboratory (e.g., level ground walking). To accommodate various activities in real-world scenarios, control strategies must include the ability to safely and seamlessly transition between activity-specific controllers. One potential solution to this challenge is to the infer wearer's intent using pattern recognition of locomotion sensor data. To this end, we developed an intent recognition framework implementing convolutional neural networks with image encoding (i.e. spectrogram) that enables prediction of the upcoming locomotor activity of the wearer's next step. In this letter, we describe our intent recognition system, comprised of a mel-spectrogram and subsequent neural network architecture. In addition, we analyzed the effect of sensor locations and modalities on the recognition system, and compared our proposed system to state-of-the-art locomotor intent recognition strategies. We were able to attain high classification performance (error rate: 1.1%), which was comparable or better than previous systems.
Recent trends in acute myocardial infarction among the young.

Purpose of review In recent decades, the incidence of myocardial infarction (MI) has declined among the general population. However, MI rates in the young have not decreased as much as has been observed among older individuals. This review will focus on recent trends of MI in young patients, factors that may account for these trends, and implications for future prevention. Recent findings MI rates in young patients, particularly in women, have not decreased in the same fashion as they have for their older counterparts, with some studies reporting an increase. The reasons for these findings include underestimation of cardiovascular risk, and accordingly treatment, in the young, as well as an increasing prevalence of risk factors such as obesity and diabetes. Summary Better recognition and treatment of cardiovascular risk factors among young adults may improve outcomes. There is a need for improved methods to assess and treat cardiovascular risk in young individuals.
Do configuration management tools make systems more secure?: an empirical research plan

Configuration Management Tools (CMT) help developers manage the system and installed application in an automated and efficient manner. However, misconfiguration in these tools can make a system vulnerable to compromises. Whether the usage of these tools makes the systems secure - this question can only be answered through empirical evidence. Hence, we propose a empirical research plan on the impact of CMT on systems where these tools have been applied. As a case, we will investigate the case of Endpoint Linux Management System managed by Puppet, a popular configuration management tool.
Leave or Die: Dispersal of Red-Bellied Mudsnakes (Farancia abacura) from their Home Ranges in an Isolated Wetland

We radiotracked eight, free-living, Red-Bellied Mudsnakes (Farancia abacura) from April to October 2019 in a bottomland hardwood forest wetland in Central Arkansas. Four snakes emerged in April from their overwintering sites in an earthen dam of a 1.2 ha pond and confined all of their movements to the pond basin. All four snakes were lost to predators during the course of the year. Four other snakes emerged from overwintering and dispersed up to 1580 m from the pond. One dispersing snake was lost to a predator when it returned to the pond. Dispersing snakes followed ephemeral streams upstream and downstream, ditches, and flooded bottomlands. The dispersal movements occurred in an extraordinarily wet period that began in August 2018 and continued through August 2019. These results contrasted sharply with the radiotracking results of eight, free-living, F. abacura at the same locality in 2018, each of which maintained a home range in the pond and experienced no predation. Included in the eight 2018 snakes were three of the dispersing snakes radiotracked in 2019. Possible year-to-year variation in movement patterns driven by environmental variability and predator pressure should be considered in designing management plans for at-risk wetland species.
Romantic Parts and Wholes, Statistical and Literary

This chapter reads Romantic fragments alongside early efforts by British statistical societies to define the relation between part and whole. Writers and statisticians of the early nineteenth century both asked how fragmented parts—whether disparate data sets or jumbled pages—might be combined, and what their combination might mean. Tracing the interdependence of statistical and literary answers to these questions, this chapter argues that both spheres settle on the nation as the ultimate unit for aggregation. Readings focus on Mary Shelley’s backward-looking meditation on the fragment in The Last Man, Shelley’s work editing her husband Percy Shelley’s poetry after his death, and the work of William Cooke Taylor, Charles Babbage, and statistical societies of the 1830s.
Incentive-Compatible Triaging in Deceased Donor Transplantation

In the allocation of hearts and livers, the U.S. transplantation authority has recurrently faced a pervasive problem of asymmetric information about transplant candidates’ medical urgency. I investigate the optimal design of prioritization rules under different social welfare functions while taking patients’ incentives to misrepresent medical needs into account. I find that the current prioritization scheme is not incentive compatible. Moreover, I deliver a way of incentivizing truth-telling by prioritizing patients using their medical urgency histories, which is remarkably different from how the latter are used in practice. Despite screenining is possible, when the social objective is to prioritize medically urgent patients its optimality is ambiguous, and in some parameter regions pooling is preferred. In sharp contrast, when social preferences are utilitarian pooling is preferred most of the time. On top of providing insights for addressing the informational asymmetries, these results offer a novel perspective on a controversy among stakeholders and ethicists on the principles for allocating organs.
The Influence of Composition on the Solidification Path and Microstructure of HP-Nb Alloys

Austenitic stainless steels such as 25Cr-35Ni-Nb, HP-Nb alloys are commonly used in high-temperature applications above 850 °C. The HP-Nb alloys are used in the as-cast condition and exhibit good creep properties due to chromium and niobium eutectic carbide strengthening. The size, morphology and distribution of these carbides are related to the nominal composition and solidification conditions, which result in differences in mechanical properties. Although previous work has provided qualitative relations between composition and microstructure, there is insufficient quantitative information regarding the influence of composition on the solidification behavior and resultant microstructure. Therefore, the objective of this study is to improve the understanding of the solidification of HP-Nb alloys through the development of a quantitative model. A systematic matrix of 12 alloys was characterized via quantitative image analysis, differential thermal analysis and electron microprobe analysis. A quantitative solute redistribution model was developed using solidification equations and an experimentally derived γ-C-Cr-Nb, pseudo-quaternary liquidus projection. The quantitative model was validated for three experimental alloys and two industrial alloys, with good agreement between the measured and predicted percent total eutectic. Experimental results indicate that the volume fraction of chromium carbides are primarily controlled by carbon additions and niobium carbides are primarily controlled by niobium additions. The results of this work show the novel development and application of a pseudo-quaternary liquidus projection and improves the understanding of the relationship between composition and the solidification of austenitic stainless steels.
Sexting, pressured sexting and associations with dating violence among early adolescents

Abstract Many adolescents engage in sexting, the sending of self-made sexually explicit images, within the context of a romantic relationship. The aim of the current study is to contribute to the literature by assessing the associations between sending a sext to a romantic partner, asking for a sext from a romantic partner, and dating violence among adolescents, while accounting for gender and sexting-related pressure. Respondents included 694 early adolescents (47 % female, mean age = 13 years, SD = 1.15) who participated in a large school-based study in Nicaragua. Measures included dating violence victimization and perpetration, sending a sext to a romantic partner, asking for a sext and associated pressures. Chi-square tests assessed gender differences and linear regression analyses tested for associations with dating violence perpetration and victimization. Sending a sext to a romantic partner and asking the romantic partner for a sext were significantly associated with dating violence victimization among girls, but not among boys. Boys were more likely than girls to perceive pressure to engage in sexting with their romantic partner. Perceived pressure to send sexts and to ask for sexts within romantic relationships was significantly associated with dating violence perpetration for boys but not girls. Several forms of sexting are related with dating violence. Findings provide more insight in the gendered nature of sexting and have implications for sexual and relationship education.
Tunable and scalable fabrication of plasmonic dimer arrays with sub-10 nm nanogaps by area-selective atomic layer deposition

Nanogaps in metallic nanostructures produce local field enhancements with potential applications in surface enhanced spectroscopy, solar energy conversion, and photocatalysis. Atomic layer deposition is applied as a conformal coating to modify nanogap sizes and tune the optical properties of plasmonic dimer arrays with sub-10 nm nanogaps. Nanostructures are fabricated using layers of gold and palladium to combine features of plasmonics and area-selective atomic layer deposition, where copper metal is deposited on palladium-covered surfaces. Direct measurements of optical extinction for successive smaller nanogaps and thicker copper coatings show that spectral features become broadened at first due to heating-induced shape changes but subsequently sharpen as copper coatings form on palladium structures. Furthermore, longitudinal resonances of plasmonic dimers blue shift for thin coatings due to heating and decreasing aspect ratio, but thicker coatings lead to red shifts due to narrowing nanogaps. Together, these results show that area-selective atomic layer deposition is a promising tool for achieving large area arrays of plasmonic dimers with sub-10 nm nanogaps.
“They Don’t Know What They Need”: A Call for Critical Reflection in Community School Leadership to Address the Pervasive Creep of Deficit Perspectives:

Washington Hunt is an urban community school attempting to balance the implementation of equity initiatives that meet the needs of minoritized students and families while preventing the adoption of...
Anxiety and temporal self-appraisal: How people with anxiety evaluate themselves over time.

Abstract Background Previous studies found that psychopathology is associated with distinct self-perceptions over time. Euthymic individuals report experiencing a self-enhancement bias, with self-appraisal increasing over time. In contrast, depressed individuals report viewing a personal decline from past to present and anticipated self-improvement from present to future. This study examined the association between the singular presence of anxiety and temporal self-appraisal. Methods Using the Depression Anxiety and Stress Scale, this study examined a depressed (n = 142), anxious (n = 95), comorbid depressed and anxious (n = 335), and euthymic group (non-depressed and non-anxious, n = 535), on a validated task of temporal self-appraisal. Results Anxiety has a unique association with temporal self-appraisal that differs from the other disorders examined in this study. Specifically, individuals with anxiety had a similar positive trend of self-view to the euthymic group; however, their overall trend was lower at each temporal point. Individuals with depression had a stable past-to-present self-view and an improving present-to-future self-view. Limitations The use of an online self-report sample without longitudinal assessment of variables, while sufficient for the intent of the present study, limits the potential extrapolation from this sample, as well as prevents the determination of the direction of causality. Conclusions While individuals with anxiety demonstrate a positive sense of improvement over time, their psychopathology is associated with a negative bias in their perception of their past, present, and future selves. These findings have important implications for clinicians regarding potential interventions and treatment for anxiety and depression.
The Political Attitudes and Activities of Missouri Synod Lutheran (LCMS) Clergy in 2001 and 2009: A Research Note

Research has explored Lutheran clergy and politics at various time points, though few studies have focused longitudinally on this significant religious tradition. Using Cooperative Clergy Survey data, this research note examines the theological and the political attitudes, beliefs, and activities of pastors in one branch of American Lutheranism, the Lutheran Church Missouri Synod (LCMS), in 2001 and 2009. The results suggest that LCMS clergy became more conservative, both theologically and politically, during this time. Moreover, LCMS clergy indicated higher levels of approval for a variety of political actions in 2009 than in 2001, as well as reporting higher levels of actual political involvement in 2008 than in 2000. A new breed of LCMS clergy may be emerging that is more comfortable engaging with the public square.
p-type ZnO thin films grown by MOCVD

ZnO has demonstrated a possibility to be doped as a p-type by using nitrogen and other group-V elements. A high nitrogen doping concentration by metalorganic chemical vapor deposition (MOCVD) with nitric oxide (NO) gas has been achieved. However, the processing window for obtaining the p-type ZnO:N film is very narrow, and the hole concentration is typically low. Possible compensation and passivation effects have been studied. Hydrogen and carbon elements are detected by secondary-ion mass spectroscopy (SIMS). Considering the other experimental and modeling results, we believe that the impurities inadvertently incorporated with the zinc precursor could be compensating or passivating the nitrogen acceptor and result in the low hole concentration.
Recognizing outstanding achievements

One function of any professional society is to provide an objective, informed means for recognizing outstanding achievements in its field. In AGU's Ocean Sciences section we have a variety of means for carrying out this duty. They include recognition of outstanding student presentations at our meetings, dedication of special sessions, nomination of individuals to be fellows of the Union, invitations to present Sverdrup lectures, and recommendations for Macelwane Medals, the Ocean Sciences Award, and the Ewing Medal. Since the decision to bestow these awards requires initiative and judgement by members of our section in addition to a deserving individual, it seems appropriate to review the selection process for each and to urge you to identify those deserving of recognition.
A unified approach to conservation laws in general relativity, gauge theories, and elementary particle physics

A unified treatment of conservation laws in general relativity, gauge theories, and elementary particle physics is formulated in the setting of principal fiber bundles. The group AUT(P) is introduced as the general gauge transformation group that covers space-time coordinate transformations. A set of master equations is exhibited for any Lagrangian density generally covariant with respect to AUT(P). The symmetry group for elementary particle theory is shown to be the structure group of the bundle only in the special case when the gauge potential is flat and the space-time is simply connected. In the general case, the symmetry group is reduced to the symmetry group of the gauge potential. This natural mechanism for a reduction of the symmetry group is speculated on as a model for spontaneous symmetry breaking.
Rapid runoff via shallow throughflow and deeper preferential flow in a boreal catchment underlain by frozen silt (Alaska, USA)

In high-latitude catchments where permafrost is present, runoff dynamics are complicated by seasonal active-layer thaw, which may cause a change in the dominant flowpaths as water increasingly contacts mineral soils of low hydraulic conductivity. A 2-year study, conducted in an upland catchment in Alaska (USA) underlain by frozen, well-sorted eolian silt, examined changes in infiltration and runoff with thaw. It was hypothesized that rapid runoff would be maintained by flow through shallow soils during the early summer and deeper preferential flow later in the summer. Seasonal changes in soil moisture, infiltration, and runoff magnitude, location, and chemistry suggest that transport is rapid, even when soils are thawed to their maximum extent. Between June and September, a shift occurred in the location of runoff, consistent with subsurface preferential flow in steep and wet areas. Uranium isotopes suggest that late summer runoff erodes permafrost, indicating that substantial rapid flow may occur along the frozen boundary. Together, throughflow and deep preferential flow may limit upland boreal catchment water and solute storage, and subsequently biogeochemical cycling on seasonal to annual timescales. Deep preferential flow may be important for stream incision, network drainage development, and the release of ancient carbon to ecosystems.
Electron-injection detectors for swept source optical coherence tomography

Electron-injection detectors are used in an OCT system for the first time. Compared to a commercial p-i-n detector, electron-injection detectors show ∼20 dB higher SNR. This could lead to OCT systems without the need for balanced-detection.
Transformations of Sperm Nuclei Incorporated Into Aged and Unaged Hamster Eggs

The extent of male pronuclear development in aged and unaged hamster eggs was examined by electron microscopy. Observations are presented demonstrating that although hamster eggs, aged 18 hours in vivo and lacking zonae pellucidae, may be fertilized in vitro, transformation of incorporated sperm nuclei into male pronuclei is significantly retarded. By 6 hours postinsemination, 50% of the sperm nuclei incorporated into aged eggs failed to disperse (vs. 19% in unaged eggs); sperm were observed in various stages of dispersion (20%), but only 30% developed into pronuclei (vs. 18 and 63% in unaged eggs, respectively). These results are discussed in reference to concepts of nucleocytoplasmic interactions involving male pronuclear development.
Other opportunistic infections of the central nervous system in AIDS.

Publisher Summary Tuberculosis is the most common opportunistic infection and a leading cause of death in persons infected with HIV worldwide. Central nervous system (CNS) tuberculosis occurs in about 15% of HIV-infected patients with tuberculosis. Intravenous drug use is a significant risk factor for HIV-associated tuberculosis. Primary infection with Mycobacterium tuberculosis (M. tuberculosis) is usually acquired by inhalation. This is followed by hematogenous dissemination to lymph nodes where a local inflammatory response results in the formation of granulomata and the bacteria are contained within membrane-bound compartments in tissue macrophages. The most common CNS manifestation of infection with M. tuberculosis irrespective of the associated HIV infection is meningitis. The involvement of the spinal axis is common in tuberculous meningitis (TBM) and may result from exudates filling the spinal subarachnoid space causing adhesive radiculitis, infarctions of the spinal cord or nerve roots due to the inflammation of spinal arteries, intramedullary tuberculomas or abscesses, or epidural abscesses extending contiguously from vertebral or perispinal infection. Non-tuberculous mycobacterial infections are common in HIV-infected individuals and typically involve the lungs but often disseminate to other organs. The most common agent involved is Mycobacterium avium-intracellulare (MAI).
Intracellular and extracellular β-N-acetylhexosaminidases from Physarum polycephalum: Comparison of vegetative and spherulation enzymes

Abstract Vegetative microplasmodia of the slime mold, Physarum polycephalum, produce an intracellular β-N-acetylhexosaminidase enzyme when grown on a medium containing 1% glucose, 0.15% yeast extract, and 1% peptone. When early log-phase microplasmodia are induced to differentiate to spherules by starvation in a salts medium, they excrete an extracellular β-N-acetylhexosaminidase. Both of these enzymes have been purified to apparent homogeneity. Characterization studies showed that the extracellular enzyme was nonidentical to the preexisting, vegetative enzyme and the enzyme in completed spherules. Evidence demonstrating dissimilarities between the two proteins included marked differences in (i) specificities for several natural and synthetic substrates, (ii) various kinetic parameters, (iii) relative net charges as evidenced by different elution behavior from similar DE-52 cellulose chromatography columns, (iv) carbohydrate contents, and (v) subunit polypeptide molecular weights. Conclusive evidence for their nonidentity was shown in their respective amino acid compositions and divergent immunological properties. The extracellular β-N-acetylhexosaminidase demonstrated a subunit molecular weight of 25,300; the intracellular enzyme subunit molecular weight was 40,500. The extracellular enzyme, with the smaller polypeptide subunit, contained 1.79 times as many aromatic amino acid residues in tyrosine, phenylalanine, and tryptophan as the intracellular enzyme. Thus, the extracellular enzyme could not have been comprised of subunits derived from limited proteolytic hydrolysis of the larger subunits of the intracellular enzyme. Rabbit antisera prepared against each purified β-N-acetylhexosaminidase failed to yield precipitin bands with the heterologous antigen in immunodiffusion tests. Thus, apparently distinct structural genes code for these two enzymes and they may serve different, but unidentified, physiological functions.
Utility of nongated multidetector computed tomography for detection of left atrial thrombus in patients undergoing catheter ablation of atrial fibrillation.

Objectives The aim of this study was to determine whether multidetector computed tomography (MDCT) is able to exclude left atrial appendage (LAA) thrombus in patients referred for catheter ablation of atrial fibrillation (CAAF). Background MDCT is commonly used to render pulmonary vein and left atrial anatomy before CAAF. Transesophageal echocardiography (TEE) is also often performed before the ablation to exclude LAA thrombus. Whether MDCT alone is sufficient to exclude LAA thrombus is unknown. Methods Patients referred for CAAF at the Mayo Clinic between March 2004 and October 2006 were included. Clinical data, 64-slice MDCT (nonelectrocardiography-gated), and TEE were all analyzed. Image data were independently reviewed by 2 cardiac radiologists blinded to the TEE findings. The appearance of the LAA was defined as normal (fully opacified) or abnormal (underfilled). Results Four hundred two patients (mean age 56 ± 10 years; 76% male; ejection fraction 56 ± 10%) were included. Three hundred sixty-two had no evidence of a filling defect by ungated MDCT or left atrial spontaneous echo contrast or thrombus by TEE. In 40 patients, the LAA was “underfilled” with 9 definite thrombi confirmed by TEE. Sensitivity and specificity was 100% and 92%, respectively, with a negative predictive value of 100% and positive predictive value of 23%. In patients with LAA underfilling, Doppler-derived LAA emptying velocities were substantially reduced (mean 19 cm/s; range 6 to 61 cm/s) below the normal range. A higher CHADS2 (congestive heart failure, hypertension, age older than 75 years, and diabetes) score (1.6 vs. 1.1) was observed in patients with LAA filling defects. No cases of LAA thrombus were observed in patients age Conclusions In patients referred for CAAF, MDCT is a sensitive (100% sensitivity) imaging modality that could be used alone especially in patients age
Two tools to test time series data for evidence of chaos and/or nonlinearity.

Two computer programs are described for evaluating the evidence for chaos and nonlinearity in time series data. “bx” is an efficient algorithm for computing the correlation integral (from which correlation dimension can be estimated); and “surrogat” is a Fourier-transform-based algorithm for generating surrogate data consistent with a null hypothesis that the data arise as a result of a linear stochastic process.
Dynamics of tissue neutrophil sequestration after cutaneous burns in rats.

Abstract Background. Neutrophil recruitment in organs after burns may cause local vascular damage, which can be reduced by agents blocking neutrophil adhesion to the vascular wall. Because these agents may increase susceptibility to infection, it is important to characterize the dynamics of neutrophil sequestration in order to optimize an eventual anti-adhesion therapy. Materials and methods. Rats were scald burned over 20 or 40% of their total body surface area (TBSA) and saline resuscitated. Sham controls were used. Myeloperoxidase (MPO) activity was measured in lungs, liver, kidney, gut, and burned skin up to 1 week postburn. Extravascular accumulation of 125 I-labeled bovine serum albumin ( 125 I-BSA) was measured at 12 h postburn. Results. MPO activity in lungs, liver, and kidney was increased within 3 h postburn and returned to normal within 24–48 h. Peak MPO levels occurred at 6–12 h postburn and were similar for both burn sizes. No MPO increase was observed in gut. MPO levels in burned skin did not increase before 6 h, peaked at 24 h, decreased at 48 h, but remained elevated for up to 7 days. Neutrophil recruitment in lungs and liver was confirmed histochemically. No neutrophils were found in kidneys. Extravascular 125 I-BSA was increased in lungs, liver, kidneys, and gut, in the 40% TBSA group only. Conclusions. Neutrophil sequestration in remote organs is a transient phenomenon while neutrophil homing into the wound site is sustained. Neutrophil accumulation dynamics are independent of burn size, although a minimum size is required to trigger vascular damage. Temporary early anti-adhesion therapy to reduce lung and liver neutrophil sequestration with little impact on neutrophil homing into the burn wound may be possible.
How a System Backfires: Dynamics of Redundancy Problems in Security

Increasing attention is being paid to reliability, safety, and security issues in social systems. Scott Sagan examined why more security forces (a redundancy solution) may lead to less security. (1) He discussed how such a solution can backfire due to three major issues (i.e., “common-mode error,” “social shirking,” and “overcompensation”). In this article, using Sagan’s hypotheses, we simulate and analyze a simple and generic security system as more guards are added to the system. Simulation results support two of Sagan’s hypotheses. More specifically, the results show that “common-mode error” causes the system to backfire, and “social shirking” leads to an inefficient system while exacerbating the common-mode error’s effect. Simulation results show that “overcompensation” has no effect of backfiring, but it leads the system to a critical state in which it can easily be affected by the common-mode error. Furthermore, the simulation results make us question the importance of the initial power of adversaries (e.g., terrorists) as the results show that, for any exogenous level of adversary power, the system endogenously overcompensates to a level that makes the system more susceptible to being attacked.
Digestion in Haliotis rufescens Swainson (Gastropoda: Prosobranchia)

Digestion was studied in the marine archaeogastropod Haliotis rufescens, with emphasis on identification of absorptive regions in the gut. Extracellular enzymes were found in the digestive fluid. Absorption in the digestive gland was demonstrated by autoradiography of tissue sections after feeding animals on 14C-labeled algae. After absorption, food was retained apically in the absorptive cells of the digestive gland in an insoluble form. Possible mechanisms of uptake are discussed. It was shown chromatographically that small compounds derived from the food were present in both the crop fluid and blood early in digestion. Studies in vitro showed that the crop epithelium was permeable to small organic materials. Glucose and phenylalanine were found to have been taken up by the crop epithelium in considerable quantities; smaller amounts were passed through the epithelium, and would in life be transferred to the blood. The surface area of the food mass was seen to be increased in an intestinal sorting area at the beginning of the intestine. The intestinal epithelium was shown in vitro to be permeable to glucose. It is concluded that the large crop is an important region of absorption, and that digestion and absorption continue to occur as food passes along the intestine.
PATTERN RECOGNITION/EXPERT SYSTEM FOR IDENTIFICATION OF TOXIC COMPOUNDS FROM LOW RESOLUTION MASS SPECTRA

Abstract An empirical rule-based pattern recognition/expert system for classifying, estimating molecular weights and identifying low resolution mass spectra of toxic and other organic compounds has been developed and evaluated. The system was designed to accommodate low concentration spectra and provide some information for mixtures. It consists of a classifier followed by molecular weight estimators, filters and identification modules. Computed series of allowed molecular weights and selected base peaks for five classes are used in the filters to reduce misclassification and ensure correct identification. The target classes are nonhalobenzenes; chlorobenzenes; bromo- and bromochloroalkanes/alkenes; mono- and dichloroalkanes/alkenes; and tri-, tetra- and pentachloroalkanes/alkenes. The identification module for the 75 target compounds relies upon the high accuracy of the molecular weight estimators and base peak data for unique identification. The total system was extensively tested with reference spectra of 32 potential air pollutants, 99 randomly selected compounds, 37 gas chromatographic-mass spectroscopic (GC-MS) field spectra and with 400 pharmaceutical related spectra. Even with incomplete spectra the classification and identification performance was very good with accuracies of 97 (test, random and pharmaceutical) and 95% (field GC-MS). The median absolute deviations from the true molecular weights of the test, random, field and pharmaceutical spectra were 1–2 Da and the average absolute deviations were 6–10 Da. The program is very fast and runs on a personal computer.
Applications of asymmetric collimation on linear accelerators

Frequency of use of asymmetric collimation (AC) at an academic radiation oncology center equipped with AC-capable linear accelerators was determined, and the type of use was cataloged. Records of patients beginning radiation treatment at U.C. Davis Cancer Center within a 3-month period (3/1/92 to 5/31/92) were reviewed. Forty-seven percent of 102 patients and 56% of 123 courses of treatment involved AC. Six common uses of AC were identified: beam-split field matching, planned boosts, other field size changes, adjustments to match divergent fields, matchline feathering, and opposed tangential fields. This study demonstrates that asymmetric collimation is a useful and powerful clinical treatment tool with widespread applications to radiation therapy.