cssi/SciSciGPT-SciSciNet huggingface dataset:
Scheduling Design Activities

The design process can be divided into a number of activities that are performed according to precedence constraints among them. The objective of concurrent engineering approach is to minimize the total design time without violating any of the constraints. A limited number of available resources constrain the simultaneous execution of design activities. The execution of succeeding design activities depends on the available information provided by the preceding activities. The smooth flow of information from the beginning to the end of the design process is a key factor for successful and timely completion of the design process. In this paper, a pull system approach for management of activities in the design process is proposed. In this approach, the dynamic scheduling policies are adopted. A heuristic for scheduling of activities is developed.
Effect of unsteady pressure rise on flame propagation and near-cold-wall ignition

Abstract Thermodynamic pressure rise during combustion is a key feature in internal combustion engines. Yet, hardly any studies have been conducted to investigate the effects of transient pressure rise on flame propagation as well as on the ignition of the unburned gas. In this study, the effects of unsteady pressure rise were parametrically studied using a one-dimensional reacting flow model in which the thermodynamic pressure variation is an independent variable and thus its rate of rise can be controlled. It was determined that large rates of pressure rise can significantly increase the mass burning flux of a laminar flame and that this modification becomes more pronounced at higher pressure and temperature conditions. Furthermore, it was shown that the development of ignition near a cold wall, for mixtures that exhibit negative temperature coefficient behavior, is very sensitive to rate of change of pressure. The near-wall ignition behavior was found also to be rather sensitive to the prevailing pressures and temperatures whose values control whether ignition will occur in the main-gas or within the thermal boundary layer.
Percutaneous versus surgical tracheostomy: timing, outcomes, and charges.

OBJECTIVES/HYPOTHESIS The purpose of this study was to compare timing of procedure, patient characteristics, outcomes, and charges for patients who underwent percutaneous versus surgical tracheostomy. STUDY DESIGN Retrospective cohort study. METHODS A retrospective analysis was performed for all patients who underwent tracheostomy in 2015 to 2016 in New York State. Patients were identified using International Classification of Diseases, 10th Revision, Clinical Modification codes and stratified to the type of tracheostomy performed. The primary outcome of interest was mortality at index stay. Secondary outcomes of interest included length of stay and total hospitalization charges. RESULTS Of the 8,682 patients, 2,488 (28.7%) underwent percutaneous and 6,194 (71.3%) underwent surgical tracheostomy. At hospitals where both procedures were performed, percutaneous tracheostomy patients were older, had more comorbidities, and had lower income (P < .05). Timing of the tracheostomy relative to admission did not affect the type of tracheostomy performed. While controlling for patient characteristics and complications during the visit, percutaneous tracheostomy was associated with increased mortality (odds ratio [OR]: 1.17, 95% confidence interval [CI]: 1.03-1.33, P = .0153) and increased hospital charges (OR: + 7.76%, 95% CI: 5.4-10.11, P < .0001). Length of stay was not affected by procedure type. CONCLUSIONS Surgical tracheostomies are more commonly performed than percutaneous tracheostomies across New York State. Older, lower-income, and sicker patients have a higher chance of receiving percutaneous tracheostomies. Percutaneous approaches were associated with statistically significant increased mortality and higher charges despite no difference in length of stay. Further studies are needed to determine if these differences in outcomes are clinically significant. LEVEL OF EVIDENCE NA Laryngoscope, 128:2844-2851, 2018.
Crystallographic evidence for two‐metal‐ion catalysis in human pol η

Extensive evidence exists that DNA polymerases use two metal ions to catalyze the phosphoryl transfer reaction. Recently, competing evidence emerged, suggesting that a third metal ion, known as MnC, may be involved in catalysis. The binding of MnC was observed in crystal structures of the replication complexes of human polymerase (pol) η, pol β, and pol μ. Its occupancy (qMnC ) in the pol η replication complexes exhibited a strong correlation with the occupancy of the formed product pyrophosphate (qPPi ), i.e., qMnC ∝ qPPi . However, a key piece of information was missing that is needed to distinguish between two possible sequences of events: (i) the chemical reaction occurs first with only two meal ions, followed by the binding of MnC in a "catch-the-product" mode; and (ii) MnC binds first, followed by the chemical reaction with all three metal ions in a "push-the-reaction-forward" mode. Both mechanisms can lead to a strong correlation between qMnC and qPPi . However, qMnC ≤ qPPi in the first scenario, whereas qMnC ≥ qPPi in the second. In this study, an analysis of crystallographic data published recently for pol η complexes shows that the formation of the product pyrophosphate definitely precedes the binding of MnC. Therefore, just like all other DNA polymerases, human pol η employs a two-metal-ion catalytic mechanism. Rather than help to catalyze the reaction, MnC stabilizes the formed product, which remains trapped inside the crystals, before it slowly diffuses out.
Bordering Performances: Staging the comedia at the Chamizal National Memorial (El Paso, Texas)

Held at Chamizal National Memorial in El Paso, Texas, since 1975, the Siglo de Oro Drama Festival has become the focal point for US theatrical stagings and scholarship on the living genre of comedia performance. Many critics would be surprised to discover that this particular festival is the oldest in the world exclusively dedicated to Hispanic early modern theatre. With an organizational mission to engage in community outreach, the Siglo de Oro Drama Festival has also become a paragon of access to the performing arts and effective intercultural dialogue about hispanismo, or legacies of Spanish American culture, presently straddling the US/Mexican border. This article will probe the cultural politics of (re)staging the comedia in El Paso, and exploring how borderland Anglo and Hispanic communities have become connoisseurs of this dramatic genre staged continuously for over forty years
Complex penetrating cervical wound.

A 24-year-old man presented to the trauma center with gunshot wounds to the neck, chest and back. The patient was awake but lethargic with a heart rate of 120 beats per minute, a systolic blood pressure of 80 mm Hg and absent breath sounds on the right. He was noted to have an expanding hematoma of the left neck under a gunshot wound, a gunshot wound to the left chest at the level of the nipple, a gunshot wound overlying the left scapula, and a fourth gunshot wound penetrating the left deltoid muscle. The most appropriate first step in management of this patient in addition to resuscitation is: 1. Foreign body X-ray series. 2. Left anterolateral thoracotomy. 3. Orotracheal intubation/right thoracostomy tube. 4. Pressure dressing to left neck. The patient underwent orotracheal intubation, insertion of a right thoracostomy tube, and transfusion of blood through large bore intravenous catheters. A foreign body series demonstrated a deep sulcus sign on the left with a pulmonary contusion, a retained bullet in the region of the right shoulder and several bullet fragments in the left shoulder (figure 1). Subsequently, a left-sided thoracostomy tube was inserted with drainage of a hemothorax. After transfusion of 3 units of packed red blood cells and 3 units of plasma, the patient’s systolic blood pressure increased to 120 mm Hg and his heart rate decreased to 80 beats per minute. As the patient’s cervical hematoma was stable, a CT scan of the neck and chest was performed with a single load of intravenous contrast. The CT scan demonstrated an intimal defect in the left common carotid artery and a trajectory highly concerning for esophageal perforation (figure 2). Figure 1 Paper clips mark gunshot wounds. Red arrows are anterior and blue arrows are posterior. Figure 2 CT scan demonstrating carotid (red arrow) and esophageal (blue arrow) injuries. The most …
Steady-state periodic solutions of the nonlinear wave propagation problem of a one-dimensional lattice using a new methodology with an incremental harmonic balance method that handles time delays

A new methodology is developed in this work to solve a one-dimensional (1D) nonlinear wave propagation problem. In its response, the space variable is converted to time functions at different locations, and the resultant time functions are merged with the time variable. Since the merged variables are essentially time-delay variables, the main point of the methodology is that the governing equation of the nonlinear wave propagation problem can be converted to a corresponding nonlinear delay differential equation (DDE) with multiple delays. The new methodology is shown how to formulate the converted DDE, and a modified incremental harmonic balance method is used to solve the 1D nonlinear DDE by introducing a delay matrix operator, where a formula of the Jacobian matrix is derived and can be efficiently and automatically used in the Newton method. This new methodology is demonstrated by solving examples of 1D monatomic chains under the nonlinear Hertzian contact law and with cubic springs. Results well match those in previous works, but derivation effort of solutions and calculation time can be significantly reduced here. When the algorithm of the methodology is compiled as a computer program, there is no additional derivation required to solve wave propagation problems associated with different governing equations.
Comparison of a spiking neural network and an MLP for robust identification of generator dynamics in a multimachine power system

The application of a spiking neural network (SNN) and a multi-layer perceptron (MLP) for online identification of generator dynamics in a multimachine power system are compared in this paper. An integrate-and-fire model of an SNN which communicates information via the inter-spike interval is applied. The neural network identifiers are used to predict the speed and terminal voltage deviations one time-step ahead of generators in a multimachine power system. The SNN is developed in two steps: (i) neuron centers determined by offline k-means clustering and (ii) output weights obtained by online training. The sensitivity of the SNN to the neuron centers determined in the first step is evaluated on generators of different ratings and parameters. Performances of the SNN and MLP are compared to evaluate robustness on the identification of generator dynamics under small and large disturbances, and to illustrate that SNNs are capable of learning nonlinear dynamics of complex systems.
Diverse and inclusive high courts: a global and intersectional perspective

Critical race feminists call attention to the ways in which multiple and overlapping forms of privilege and discrimination shape individual experiences and perspectives. In this article, we argue t...
The Survival of Mafic Magmatic Enclaves and the Timing of Magma Recharge

Many intermediate to felsic intrusive and extrusive rocks contain mafic magmatic enclaves that are evidence for magma recharge and mixing. Whether enclaves represent records of pro-longed mixing or...
Clinically isolated aortitis: imaging features and clinical outcomes: comparison with giant cell arteritis and giant cell aortitis

(1) describe imaging features of CIA, (2) compare dilation rate and wall thickening of aortic aneurysms in patients with CIA versus those with giant cell arteritis/aortitis (GCA), (3) present clinical outcomes of CIA patients. Retrospective search of electronic records from 2004 to 2018 yielded 71 patients, 52 of whom were female, with a mean age of 67.5 ± 9.0 years old, with a new clinical diagnosis of cranial or extracranial GCA (GCA group), and giant cell aortitis revealed by the aortic biopsy (CIA group). Comparisons between groups were conducted using the Wilcoxon rank-sum and Fisher’s exact tests. Survival from the date of initial diagnosis to the end of data collection was compared between the two groups through a log-rank test. CIA patients (n = 23; 32%) presented with cardiovascular symptoms, and none had systemic inflammatory symptoms. Inflammatory markers were significantly higher among GCA patients than among CIA patients (p < 0.0001). The CIA group demonstrated thoracic aortic aneurysms without wall thickening. None of the GCA patients (n = 48; 68%) had aneurysmal dilation in the aorta at the time of diagnosis. None of the four CIA patients had FDG uptake in the aorta, while nine out of 13 GCA patients had FDG uptake in the vessels. There was no statistically significant difference in the survival between the two groups (p = 0.12). CIA patients presented with cardiovascular symptoms and was characterized by aneurysm of the aorta without the involvement of the infrarenal aortic segment. The role of FDG-PET/CT in CIA is less certain, though none of the patients in this cohort had FDG uptake in the vessels.
Patient- and Family-Centered Video Rounds in the Pediatric Intensive Care Unit

Objective: Management of the coronavirus disease 2019 (COVID-19) pandemic has required social distancing requirements and personal protective equipment shortages, which have forced hospitals to modify patient care rounds. We describe our process developing telemedicine rounds to maintain synchronous, multidisciplinary, pediatric intensive care unit rounds. By adapting available resources using rapid process improvement (PI), we were able to develop patient- and family-centered video rounds (PFCVR). Design: When rounding team members were forced to work from home, we adapted an existing telemedicine platform (VidyoConnect) to perform PFCVR. A quality improvement (QI) team developed an initial standard process, which underwent rapid PI using a small multidisciplinary team. Setting: A 21-bed, mixed medical/surgical/cardiac pediatric intensive care unit. Participants: Critical care patients, families, physicians, consultants, nurses, and ancillary staff. Interventions: The QI team initially met daily, then weekly, sought feedback from nurses, families, and other care providers, and utilized small tests of change to improve the rounding process. Results: We established standardized, socially distanced rounds using VidyoConnect to allow synchronous, multidisciplinary PFCVR. Implementation of a schedule and rounding script facilitated efficient and effective team communication, optimized participation by the entire team, and decreased interruptions. Conclusions: The COVID-19 pandemic compromised the feasibility of the previous rounding process. PFCVR is a safe and effective tool to facilitate communication while adhering to social distancing guidelines. Use of available platforms and team-based PI is critical for successful implementation.
“Everything Is Connected”: Health Lifestyles and Teenagers’ Social Distancing Behaviors in the COVID-19 Pandemic

Social distancing during the COVID-19 pandemic requires people to engage in new health behaviors that are public, monitored, and often contested. Parents are typically considered responsible for co...
Beyond Constituent Assemblies and Referenda: Assessing the Legitimacy of the Arab Spring Constitutions in Egypt and Tunisia

In January 2014, three years after the onset of the Arab Spring, Egypt and Tunisia each adopted a new constitution. In the article, the author develops an analytical framework for assessing whether the constitutions of transitional states are legitimate, and applies that framework to the constitution-making processes in Egypt and Tunisia. The framework draws from comparative constitutional scholarship theory but offers a new way to analyze the validity of constitutions created in moments of transition and uncertainty. The framework contains three markers of constitutional legitimacy: (1) processual legitimacy through an inclusive drafting and ratification process, (2) substantive legitimacy through the incorporation of international human rights law norms, and (3) applicatory legitimacy through the inclusion of institutional mechanisms for the full and fair implementation of constitutional protections. Applying this analytical framework, the article compares and contrasts the constitution-making processes in Egypt and Tunisia and assesses the legitimacy of the Arab Spring constitutions that both nations adopted.
Scalability in Wireless Mesh Networks

Wireless mesh networks (WMNs) is emerging as a prominent technology for next-generation broadband wireless networking. They have distinct advantages over current wireless networks and because of the promise they hold, research and development in this area is progressing rapidly. However, studies in the recent past have noted that WMNs have shortcomings and the technical issues are being addressed both in the industry and academia for successful deployment for a variety of applications.
Feasibility study of longitudinal polarization scheme in the existing CESR tunnel

The longitudinally polarized beam is the powerful probe to study particle physics. In CESR, a high luminosity electron/positron collider operating at energy range around 5 GeV (B-meson) and possibly 1.5/spl sim/2.0 GeV (charm physics) in coming years, the longitudinal polarization scheme is an option to be considered for the future. In this paper the feasibility of such a scheme in the existing CESR tunnel is explored. It is shown that the Siberian snake in the collider ring, together with polarization gun and fast acceleration in synchrotron, is promising at low energy end of CESR operation.
Prospective Elementary Teachers' Aesthetic Experience and Relationships to Mathematics.

Previous research has adopted various approaches to examining teachers’ and students’ relationships to mathematics. The current study extended this line of research and investigated six prospective elementary school teachers’ experiences in mathematics and how they saw themselves as learners of mathematics. One-on-one interviews with the participants were conducted, and their written reflections were collected. A grounded-theory approach and a framework for analyzing mathematics identities were adopted in data analysis. The findings showed that the participants’ development of obligations-to-oneself was associated with not only their opportunity to exercise conceptual agency but also their aesthetic experience with mathematics. Their views on themselves as learners of mathematics had cognitive, affective, and aesthetic dimensions. The findings suggest that teachers and students can engage in a reflection on their aesthetic involvement in doing mathematics. There is a need for a local theory of aesthetics in K-12 mathematics.
Dynamic resource allocation heuristics that manage tradeoff between makespan and robustness

Heterogeneous parallel and distributed computing systems may operate in an environment where certain system performance features degrade due to unpredictable circumstances. Robustness can be defined as the degree to which a system can function correctly in the presence of parameter values different from those assumed. This work develops a model for quantifying robustness in a dynamic heterogeneous computing environment where task execution time estimates are known to contain errors. This mathematical expression of robustness is then applied to two different problem environments. Several heuristic solutions to both problem variations are presented that utilize this expression of robustness to influence mapping decisions.
Chemical and Mineralogical Composition of Fossil Molluscan Shells from the Fox Hills Formation, South Dakota

Chemical composition and mineralogy of a large number of samples of molluscan shell material from limy concretions in the Fox Hills Formation (Cretaceous) of South Dakota were determined. The results show an extremely wide range of concentrations for the minor elements Mg, Fe, Mn, Sr, and Ba and of calcite-aragonite ratios. Detailed studies of an ammonite, Sphenodiscus, a characteristic faunal element of this formation, showed that the range of minor-element concentrations could best be interpreted as the consequence of at least two separate alteration processes, involving contamination and recrystallization, probably during diagenesis. Neither visual nor mineralogic criteria can be used to predict the degree of alteration of the original shell composition. Since the alteration processes may have both added and subtracted material, one must be cautious in accepting any fossil-shell-composition data as representative of the originally deposited test.
The continuing evolution of advanced function printing

Advanced Function PrintingTM (AFPTM) has become one of the de facto printing standards. It is a broad architecture to support printing across an entire enterprise and encompasses IBM architectures as well as industry standards. AFP had its beginnings in the IBM System/370TM environment in 1984 and has since expanded to include midrange and local area network systems. Recently the capabilities of AFP have been extended beyond printing to include on-line viewing and management of presentation data. An overview of AFP capabilities was given in an earlier issue of the IBM Systems Journal, This paper traces the continuing evolution of AFP and its usage and how it is addressing the presentation requirements of businesses in the 1990s.
How to Create the Perfect Wife: Britain's Most Ineligible Bachelor and His Enlightened Quest to Train the Ideal Mate. By Wendy Moore. (New York, NY: Basic Books, 2013. Pp. vii, 343. $27.99.)

Here is an amazing story told incredibly well. During the 1760s, two wealthy young English friends, Richard Lovell Edgeworth and Thomas Day, read Jean‐Jacques Rousseau's educational/philosophical m...
Calcium-dependent regulation of glycogen synthase activity in a muscle glycogen particle☆

Abstract The calcium-dependent inactivation of glycogen synthase in an isolated glycogen-protein complex (glycogen pellet) from rabbit skeletal muscle has been investigated. Addition of 1 m m Ca2+, 10 m m Mg2+, and 1 m m ATP-γ-S to a concentrated suspension of glycogen pellet resulted in a rapid activation of glycogen phosphorylase concomitant with an inactivation of glycogen synthase. These conversion reactions were blocked by ethylene glycol bis(β-aminoethyl ether) N, N′-tetraacetic acid or by pretreatment of the complex with an antiserum to purified phosphorylase kinase. These data suggest that in the glycogen-protein complex, which may be a functional unit of glycogen metabolism in vivo, phosphorylase kinase can catalyze a Ca2+-dependent activation of glycogen phosphorylase synchronized with an inactivation of glycogen synthase. If under similar conditions phosphoprotein phosphatase activity was assayed using exogenous [32P]phosphorylase, there was an apparent inactivation of the phosphatase. Evidence is presented that this apparent inactivation of phosphatase was due to an accumulation of endogenous phosphorylase a which acted as an inhibitor to the exogenous [32P]-phosphorylase.
Fermentation Balance Approach to Estimate Extent of Fermentation and Efficiency of Volatile Fatty Acid Formation in Ruminants

Abstract A fermentation balance equation was used to estimate the extent of fermentation of rations fed at or near voluntary intake to lactating dairy cows. The rations varied in hay to concentrate ratio from 100 :0 to 20 :80 and in four trials the high concentrate ration was fed completely pelleted. The extent of fermentation varied from 71% on the hay ration to 40% on the completely pelleted high concentrate ration. The factors affecting extent of fermentation were: 1) The hay to concentrate ratio, 2) fineness of particles, and 3) level of intake. The residual heat of fermentation was 6.4% of fermented substrate, and the theoretical CO 2 /CH 4 ratio increased with increasing concentrate in the diet. The assumptions involved in these computations and the implications of the results obtained on efficiency of fermentation and feed efficiency for ruminants were discussed.
Oligomerization of HIV-1 Restriction Factor APOBEC3G Transforms it from a Fast Enzyme to a Slow Nucleic Acid Binding Protein

Human APOBEC3G (A3G) is a cellular protein that inhibits reverse transcription and replication of human immunodeficiency virus type-1 (HIV-1) in the absence of the viral protein Vif. A3G impairs viral replication by two different mechanisms, which both rely on its ability to bind single-stranded nucleic acids. First, A3G deaminates cytidine bases of viral single-stranded DNA (ssDNA). Secondly, A3G blocks DNA synthesis by reverse transcriptase (RT), the viral DNA polymerase, by a mechanism independent of catalytic activity. Seven A3G proteins are packaged per HIV-1 virion, requiring that each molecule rapidly locate deamination sites on viral ssDNA, which is a transient intermediate during reverse transcription. In contrast, the roadblock mechanism, a model in which A3G oligomerizes on the viral template strand and blocks RT-catalyzed DNA elongation, requires an extremely slow off-rate from single-stranded nucleic acids. We hypothesize that A3G exhibits fast binding kinetics as a dimer, enabling rapid deamination activity, and slow kinetics as an oligomer, preventing RT from elongating viral DNA. We use optical tweezers, in combination with fluorescence anisotropy and surface plasmon resonance, to quantify both types of binding kinetics. DNA stretching experiments reveal that the time constant for oligomerization, ranging from 200 to 1000 s, is inversely dependent on protein concentration. The apparent dissociation constant of A3G oligomerization decreases exponentially with ssDNA incubation time, dropping by an order of magnitude in 1000 s, which suggests that fast binding of catalytically active dimers converts to oligomerization on this timescale. This slow association and dissociation of A3G oligomers, which is consistent with ensemble methods, supports the roadblock hypothesis. Collectively, our measurements quantitatively characterize the complex, highly unusual nucleic acid binding kinetics of A3G responsible for its dual mechanism for inhibiting viral replication.
Large scale self-assembly of crystalline semiconductor microcomponents onto plastic substrates via microfluidic traps

We present high-yield self-assembly results of silicon microcomponents assembled onto plastic substrates. The self-assembly is achieved by engineering the fluid flow over the substrate containing an array of microfluidic traps. This simple self-assembly method has demonstrated physical yields exceeding 90% as well as electrical connections between the microcomponents and the substrate. Using templates with 1250 binding sites, we were able to study the statistical nature of the self-assembly process experimentally and determine two exponential spatial and temporal trends affecting the overall yield.
Balanced POD for model reduction of linear PDE systems: convergence theory

We consider convergence analysis for a model reduction algorithm for a class of linear infinite dimensional systems. The algorithm computes an approximate balanced truncation of the system using solution snapshots of specific linear infinite dimensional differential equations. The algorithm is related to the proper orthogonal decomposition, and it was first proposed for systems of ordinary differential equations by Rowley (Int. J. Bifurc. Chaos Appl. Sci. Eng. 15(3):997–1013, 2005). For the convergence analysis, we consider the algorithm in terms of the Hankel operator of the system, rather than the product of the system Gramians as originally proposed by Rowley. For exponentially stable systems with bounded finite rank input and output operators, we prove that the balanced realization can be expressed in terms of balancing modes, which are related to the Hankel operator. The balancing modes are required to be smooth, and this can cause computational difficulties for PDE systems. We show how this smoothness requirement can be lessened for parabolic systems, and we also propose a variation of the algorithm that avoids the smoothness requirement for general systems. We prove entrywise convergence of the matrices in the approximate reduced order models in both cases, and present numerical results for two example PDE systems.
Dense nanoparticles exhibit enhanced vascular wall targeting over neutrally buoyant nanoparticles in human blood flow.

Abstract For vascular-targeting carrier (VTC) systems to be effective, carriers must be able to localize and adhere to the vascular wall at the target site. Research suggests that neutrally buoyant nanoparticles are limited by their inability to localize to the endothelium, making them sub-optimal as carriers. This study examines whether particle density can be exploited to improve the targeting (localization and adhesion) efficiency of nanospheres to the vasculature. Silica spheres with 500 nm diameter, which have a density roughly twice that of blood, exhibit improved adhesion to inflamed endothelium in an in vitro model of human vasculature compared to neutrally buoyant polystyrene spheres of the same size. Silica spheres also display better near-wall localization in the presence of red blood cells than they do in pure buffer, likely resulting in the observed improvement in adhesion. Titania spheres (4 times more dense than blood) adhere at levels higher than polystyrene, but only in conditions when gravity or centrifugal force acts in the direction of adhesion. In light of the wide array of materials proposed for use as carrier systems for drug delivery and diagnostics, particle density may be a useful tool for improving the targeting of diseased tissues.
Deepwater Horizon oil spill impacts on Alabama beaches

Abstract. From mid June 2010 to early August 2010, the white sandy beaches along Alabama's Gulf coast were inundated with crude oil discharged from the Deepwater Horizon well. The long-term consequences of this environmental catastrophe are still unfolding. Although BP has attempted to clean up some of these beaches, there still exist many unanswered questions regarding the physical, chemical, and ecological state of the oil contaminated beach system. In this paper, we present our understanding of what is known and known to be unknown with regard to the current state of Alabama's beaches in the aftermath of the Deepwater Horizon disaster. Motivated by our observations of the evolving distribution of oil in Alabama's beaches and BP's clean-up activities, we offer our thoughts on the lessons learned from this oil spill disaster.
Functional characterization of NGF-secreting cell grafts to the acutely injured spinal cord

Previously we reported that grafts of cells genetically modified to produce human nerve growth factor (hNGF) promoted specific and robust sprouting of spinal sensory, motor, and noradrenergic axons. In the present study we extend these investigations to assess NGF effects on corticospinal motor axons and on functional outcomes after spinal cord injury. Fibroblasts from adult rats were transduced to express human NGF; control cells were not genetically modified. Fibroblasts were then grafted to sites of midthoracic spinal cord dorsal hemisection lesions. Three months later, recipients of NGF-secreting grafts showed deficits on conditioned locomotion over a wire mesh that did not differ in extent from control-lesioned animals. On histological examination, NGF-secreting grafts elicited specific sprouting from spinal primary sensory afferent axons, local motor axons, and putative cerulospinal axons as previously reported, but no specific responses from corticospinal axons. Axons responding to NGF robustly penetrated the grafts but did not exit the grafts to extend to normal innervation territories distal to grafts. Grafted cells continued to express NGF protein through the experimental period of the study. These findings indicate that 1) spinal cord axons show directionally sensitive growth responses to neurotrophic factors, 2) growth of axons responding to a neurotrophic factor beyond an injury site and back to their natural target regions will likely require delivery of concentration gradients of neurotrophic factors toward the target, 3) corticospinal axons do not grow toward a cellular source of NGF, and 4) functional impairments are not improved by strictly local sprouting response of nonmotor systems.
Self-assembly and ripening of polymeric silver-alkanethiolate crystals on inert surfaces.

We characterize and compare the reaction of alkanethiol with Ag continuous planar thin films and Ag islands on inert substrates. Ag islands generate a significantly larger (3-fold) amount of alkanethiolate than continuous Ag films at comparable conditions. The reaction with planar Ag thin films produces alkanethiol self-assembled monolayers (SAMs), whereas the reaction with Ag islands yields two dissimilar products depending on the size of the islands. Small Ag islands are more likely to be converted into multilayer silver−alkanethiolate (AgSR) crystals, while larger Ag islands form monolayer-protected clusters (MPCs). The AgSR lamellar crystals are initially small having only a few layers. However, during thermal annealing, ripening occurs that generates large AgSR lamellae having diameters of 1 μm and thickness up to 30 layers. Atomic force microscopy shows the single-layer step-heights of individual crystals which match the layer thickness obtained via X-ray diffraction analysis. The crystals have face...
Adsorption and removal of oxo-anions of arsenic and selenium on the zirconium(IV) loaded polymer resin functionalized with diethylenetriamine-N,N,N′,N′-polyacetic acid

A polymer adsorbent in which a Zr(IV)–edta complex analogue is immobilized has been prepared and applied to the removal of oxo-anions of As(III), As(V) and Se(IV). Effective retention of these anions has been demonstrated with the proposed polymer complex system. The adsorption mechanism of oxo-anions onto the Zr(IV)-chelated polymer complex has been investigated using Zr(IV)–edta as the model compound. The formation of mixed complexes with oxo-anions has been exemplified by the isolation of the carbonato complex K2[Zr(CO3)edta]·3H2O, the structure of which has been confirmed by X-ray crystallography. NMR study suggests that oxo-anions that form weak or moderate conjugate acids, including those of As(III), As(V) and Se(IV), can form mixed complexes with Zr(IV)–edta using the unsaturated coordination site. However, oxo-anions of strong conjugate acids did not show any appreciable interaction with this complex. According to these observations, retention of oxo-anions on the Zr(IV)-chelated polymer complex has been interpreted by a ligand substitution reaction. The adsorption characteristics of As(III), As(V) and Se(IV) on the Zr(IV)-loaded resin have been examined with respect to the equilibrium adsorption, percentage extraction and the effect of co-existing ions. The adsorption and desorption cycles of the oxo-anions have been demonstrated using a column packed with the proposed resin without any loss of column performance, which indicates the possibility for repeated use.
Diversity of the Pyruvate Dehydrogenase Kinase Gene Family in Humans

Abstract Recent evidence from this laboratory indicates that at least two isoenzymic forms of pyruvate dehydrogenase kinase (PDK1 and PDK2) may be involved in the regulation of enzymatic activity of mammalian pyruvate dehydrogenase complex by phosphorylation (Popov, K. M., Kedishvili, N. Y., Zhao, Y., Gudi, R., and Harris, R. A.(1994) J. Biol. Chem. 269, 29720-29724). The present study was undertaken to further explore the diversity of the pyruvate dehydrogenase kinase gene family. Here we report the deduced amino acid sequences of three isoenzymic forms of PDK found in humans. In terms of their primary structures, two isoenzymes identified in humans correspond to rat PDK1 and PDK2, whereas a third gene (PDK3) encodes for a new isoenzyme that shares 68% and 67% of amino acid identities with PDK1 and PDK2, respectively. PDK3 cDNA expressed in Escherichia coli directs the synthesis of a polypeptide with a molecular mass of approximately 45,000 Da that possesses catalytic activity toward kinase-depleted pyruvate dehydrogenase. PDK3 appears to have the highest specific activity among the three isoenzymes tested as recombinant proteins. Tissue distribution of all three isoenzymes of human PDK was characterized by Northern blot analysis. The highest amount of PDK2 mRNA was found in heart and skeletal muscle, the lowest amount in placenta and lung. Brain, kidney, pancreas, and liver expressed an intermediate amount of PDK2 (brain > kidney = pancreas > liver). The tissue distribution of PDK1 mRNA differs markedly from PDK2. The message for PDK1 was expressed predominantly in heart with only modest levels of expression in other tissues (skeletal muscle > liver > pancreas > brain > placenta = lung > kidney). In contrast to PDK1 and PDK2, which are expressed in all tissues tested, the message for PDK3 was found almost exclusively in heart and skeletal muscle, indicating that PDK3 may serve specialized functions characteristic of muscle tissues. In all tissues tested thus far, the level of expression of PDK2 mRNA was essentially higher than that of PDK1 and PDK3, consistent with the idea that PDK2 is a major isoenzyme responsible for regulation of pyruvate dehydrogenase in human tissues.
Wavelet image compression with optimized perceptual quality

ABSTRACT We proposed a perceptual image compression method by using the wavelet transform. This method is differentfrom conventional wavelet coding schemes in that the Human Visual System (HVS) characteristics is used in the quantization steps. Rather than the amplitude of wavelet coeffIcients, the contrasts of each resolution are coded. The resulting compression scheme is able to distribute the visual error uniformly over the whole image thus the visualartifact at low bit rate is minimized. Experimental results are given to show the superior visual performance of the new method in comparison with those of the conventional wavelet coders. Keywords: perceptual image coding, human visual system (HVS) model, wavelet transform. 1. INTRODUCTION The objective of lossy image compression is to minimize the bits needed to represent an image. Due to the char-acteristics of natural images, an important issue of image compression is to remove the redundancy among theclosely space-correlated image pixels. Transform coding schemes are the most popular approaches to minimize theredundancy in the images since they can sufficiently decorrelate the pixel values in the transform domain. Sincethe transform coefficients are highly uncorrelated, they require different number of bits in quantization. The otherimportant issue in compression, therefore, is how to smartly allocate the data bits to represent the more importantinformation in the coefficients. The energy compaction property of transform coding helps to concentrate a largeportion of energy in certain bands or coefficients, therefore provides a good tool for bit allocation analysis.
Total electron scattering cross sections of PH 3 and SiH 4 molecules in the energy range 90 3500 eV

Total electron scattering cross sections of PH{sub 3} and SiH{sub 4} molecules have been obtained for 90-3500-eV electrons by measuring the attenuation of the electron beam through a gas cell. The present cross sections are compared to existing experimental cross sections as well as to theoretical predictions. No previous experimental electron scattering cross sections of PH{sub 3} are reported in the literature.
At the Crossroads of Chemistry, Biology, and Materials: Structural DNA Nanotechnology

Structural DNA nanotechnology consists of combining unusual DNA motifs by specific structurally well-defined cohesive interactions (primarily sticky ends) to produce target materials with predictable 3D structures. This effort has generated DNA polyhedral catenanes, robust nanomechanical devices, and a variety of periodic arrays in two dimensions. The system has been used to produce specific patterns on the mesoscale through designing and combining specific DNA strands, which are then examined by atomic force microscopy. The combination of these constructions with other chemical components is expected to contribute to the development of nanoelectronics, nanorobotics, and smart materials. The organizational capabilities of structural DNA nanotechnology are just beginning to be explored, and the field is expected ultimately to be able to organize a variety of species that will lead to exciting and possibly revolutionary materials.
Sterility of Pediatric Lipid Emulsions Repackaged by an Automated Compounding Device

Background: The daily requirement of intravenous (IV) lipid in pediatric patients is often less than the volumes and sizes available in prepackaged, commercially available preparations. In clinical practice, IV lipid emulsions (IVLEs) have been repackaged into syringes to prevent infusions from exceeding 12 hours, to reduce waste, and to improve patient safety. Recent data suggest an increasing risk of contamination when these preparations are repackaged manually. This study investigates the sterility of small volumes of IVLE that have been repackaged into empty IV bags by means of an automated compounding device (ACD). Methods: A total of 152 IVLE bags were repackaged with an ACD in an International Standards Organization class 5 environment. IVLE repackaging was conducted over a period of 3 weeks (week 1, n = 52; week 2, n = 52; week 3, n = 48). Forty commercially available bags of IVLE served as controls. At 0, 24, 48, and 120 hours after repackaging, IVLEs were filtered and placed onto blood agar medi...
Pancreaticoduodenectomy: Does it have a role in the palliation of pancreatic cancer?

OBJECTIVE: The authors define the role of palliative pancreaticoduodenectomy in patients with pancreatic carcinoma. BACKGROUND: Decreases in perioperative morbidity and mortality and improved long-term survival associated with pancreaticoduodenectomy for patients with pancreatic carcinoma have clearly established a role for this operation when performed with curative intent. However, most surgeons remain hesitant to perform pancreaticoduodenectomy unless surgical margins are widely clear, choosing rather to perform palliative biliary and gastric bypass. METHODS: A single-institution retrospective review was performed comparing the outcome of 64 consecutive patients undergoing pancreaticoduodenectomy for pancreatic carcinoma with gross or microscopic evidence of adenocarcinoma at the surgical resection margins, and 62 consecutive patients found to be unresectable at the time of laparotomy because of local invasion without evidence of metastatic disease (stage III). Combined biliary and gastric bypass were performed in 87% of patients not resected. RESULTS: The two groups were similar with respect to age, gender, race, and presenting symptoms. The hospital mortality rate was identical in both groups (1.6%). Fifty-eight percent of patients undergoing pancreaticoduodenectomy had an uncomplicated postoperative course compared with 68% of patients undergoing palliative bypass (not significant). The length of postoperative hospital stay after pancreaticoduodenectomy was 18.4 days, which was significantly longer (p < 0.05) than for patients undergoing palliative bypass (15.0 days). The overall actuarial survival (Kaplan-Meier) was improved significantly in patients undergoing pancreaticoduodenectomy (p < 0.02). Postoperative chemotherapy and radiation therapy improved survival in both groups. CONCLUSIONS: Pancreaticoduodenectomy can be performed with a similar perioperative morbidity and mortality and only a minimal increase in hospital stay when compared with traditional surgical palliation. Pancreaticoduodenectomy with postoperative chemotherapy and radiation therapy is associated with improved long-term survival when compared with patients treated with surgical bypass. These data support the role of palliative pancreaticoduodenectomy in patients with pancreatic carcinoma and with local residual disease.
Use of optical distance sensing to track tongue motion.

We have designed a device that uses a reflected-light-sensing technique to monitor tongue movement in the frontal oral cavity. The sensing unit is composed of a LED light source and a phototransist...
A Combination of Independent Transcriptional Regulators Shapes Bacterial Virulence Gene Expression during Infection

Transcriptional regulatory networks are fundamental to how microbes alter gene expression in response to environmental stimuli, thereby playing a critical role in bacterial pathogenesis. However, understanding how bacterial transcriptional regulatory networks function during host-pathogen interaction is limited. Recent studies in group A Streptococcus (GAS) suggested that the transcriptional regulator catabolite control protein A (CcpA) influences many of the same genes as the control of virulence (CovRS) two-component gene regulatory system. To provide new information about the CcpA and CovRS networks, we compared the CcpA and CovR transcriptomes in a serotype M1 GAS strain. The transcript levels of several of the same genes encoding virulence factors and proteins involved in basic metabolic processes were affected in both ΔccpA and ΔcovR isogenic mutant strains. Recombinant CcpA and CovR bound with high-affinity to the promoter regions of several co-regulated genes, including those encoding proteins involved in carbohydrate and amino acid metabolism. Compared to the wild-type parental strain, ΔccpA and ΔcovRΔccpA isogenic mutant strains were significantly less virulent in a mouse myositis model. Inactivation of CcpA and CovR alone and in combination led to significant alterations in the transcript levels of several key GAS virulence factor encoding genes during infection. Importantly, the transcript level alterations in the ΔccpA and ΔcovRΔccpA isogenic mutant strains observed during infection were distinct from those occurring during growth in laboratory medium. These data provide new knowledge regarding the molecular mechanisms by which pathogenic bacteria respond to environmental signals to regulate virulence factor production and basic metabolic processes during infection.
Neuroprotective fractalkine in fetal alcohol syndrome.

Objective Neuroprotective peptides (SALLRSIPA [SAL] and NAPVSIPQ [NAP]) can prevent some alcohol-induced damage in fetal alcohol syndrome (FAS). Fractalkine, a chemokine constitutively expressed in the central nervous system reduces neuronal death from activated microglia. Using a model of FAS, we evaluated whether fractalkine is altered and whether NAP + SAL work through fractalkine. Study Design With an FAS model, C57BL6/J-mice were treated on gestational day 8 with alcohol (0.03 mL/g), placebo, or alcohol + peptides. Embryos were harvested after 6 hours and 10 days later. Fractalkine was measured in the protein lysate. Statistical analysis included the Kruskal-Wallis test. Results Fractalkine was significantly elevated at 6 hours (median, 341pg/mL; range, 263–424 pg/mL) vs controls (median, 228 pg/mL; range, 146–332 pg/mL; P P P = .7). Conclusion Prenatal alcohol exposure acutely elevates fractalkine, perhaps in an effort to counter the alcohol toxicity. Pretreatment with NAP + SAL prevents the acute increase in fractalkine.