cssi/SciSciGPT-SciSciNet huggingface dataset:
Functionalizing DNA nanostructures for therapeutic applications

Recent advances in nanotechnology have enabled rapid progress in many areas of biomedical research, including drug delivery, targeted therapies, imaging, and sensing. The emerging field of DNA nanotechnology, in which oligonucleotides are designed to self-assemble into programmable 2D and 3D nanostructures, offers great promise for further advancements in biomedicine. DNA nanostructures present highly addressable and functionally diverse platforms for biological applications due to their ease of construction, controllable architecture and size/shape, and multiple avenues for chemical modification. Both supramolecular and covalent modification with small molecules and polymers have been shown to expand or enhance the functions of DNA nanostructures in biological contexts. These alterations include the addition of small molecule, protein, or nucleic acid moieties that enable structural stability under physiological conditions, more efficient cellular uptake and targeting, delivery of various molecular cargos, stimulus-responsive behaviors, or modulation of a host immune response. Herein, various types of DNA nanostructure modifications and their functional consequences are examined, followed by a brief discussion of the future opportunities for functionalized DNA nanostructures as well as the barriers that must be overcome before their translational use. This article is categorized under: Nanotechnology Approaches to Biology > Nanoscale Systems in Biology Therapeutic Approaches and Drug Discovery > Emerging Technologies Biology-Inspired Nanomaterials > Nucleic Acid-Based Structures.
Classicalization of quantum fluctuations at the Planck scale in the Rh = ct universe

Abstract The quantum to classical transition of fluctuations in the early universe is still not completely understood. Some headway has been made incorporating the effects of decoherence and the squeezing of states, though the methods and procedures continue to be challenged. But new developments in the analysis of the most recent Planck data suggest that the primordial power spectrum has a cutoff associated with the very first quantum fluctuation to have emerged into the semi-classical universe from the Planck domain at about the Planck time. In this paper, we examine the implications of this result on the question of classicalization, and demonstrate that the birth of quantum fluctuations at the Planck scale would have been a ‘process’ supplanting the need for a ‘measurement’ in quantum mechanics. Emerging with a single wavenumber, these fluctuations would have avoided the interference between different degrees of freedom in a superposed state. Moreover, the implied scalar-field potential had an equation-of-state consistent with the zero active mass condition in general relativity, allowing the quantum fluctuations to emerge in their ground state with a time-independent frequency. They were therefore effectively quantum harmonic oscillators with classical correlations in phase space from the very beginning.
Does it matter?: OMPSanitizer: an impact analyzer of reported data races in OpenMP programs

Data races are a primary source of concurrency bugs in parallel programs. Yet, debugging data races is not easy, even with a large amount of data race detection tools. In particular, there still exists a manually-intensive and time-consuming investigation process after data races are reported by existing race detection tools. To address this issue, we present OMPSanitizer in this paper. OMPSanitizer employs a novel and semantic-aware impact analysis mechanism to assess the potential impact of detected data races so that developers can focus on data races with a high probability to produce a harmful impact. This way, OMPSanitizer can remove the heavy debugging burden of data races from developers and simultaneously enhance the debugging efficiency. We have implemented OMPSanitizer based on the widely-used dynamic binary instrumentation infrastructure, Intel Pin. Our evaluation results on a broad range of OpenMP programs from the DataRaceBench benchmark suite and an ECP Proxy application demonstrate that OMPSanitizer can precisely report the impact of data races detected by existing race detectors, e.g., Helgrind and ThreadSanitizer. We believe OMPSanitizer will provide a new perspective on automating the debugging support for data races in OpenMP programs.
'I Thought All You Needed for a Successful Class Was a Desk and Paper … ': Shifting Pedagogies in Pre-Service Teachers' Drawings of Early Childhood Classrooms.

This paper draws on data from an ongoing study on pre-service (PS) teachers’ perceptions of early childhood/elementary classrooms, conducted during a university course on arts and creativity in ear...
Open Science and Feminist Ethics: Promises and Challenges of Open Access:

Open science advocates argue that making data sets, studies, methodologies, and other aspects of research free from publication fees and available to scholars will increase collaborations, access, ...
Studies on Fd-fragments of human immunoglobulins. II. The preparation and characterization of peptic (Fab')2-fragments and an Fd'-fragment of IgA-myeloma proteins.

Pepsin digestion of unfolded human 7 S IgA1 myeloma proteins and of an unfolded IgA2 (1+) protein produced, under certain conditions, fragments which are similar with respect to gel filtration. The fragments contained light chains and part of the α-chains as judged by immunodiffusion experiments and urea starch gel electrophoresis. From approximate molecular weight determinations by thin layer gel filtration together with characterization of the fragments by ultracentrifuge experiments, it was concluded that (Fab′)2-like fragments had been prepared. The nature of the fragments is discussed in relation to the observed antigenic heterogeneity of (Fab′)2-like fragments from distinct myeloma proteins. Finally an Fd′α-like fragment could be isolated from one of the studied myeloma proteins; the relevance of this result is discussed in the light of the structure of Fab from human immunoglobulins.
Kronecker’s theorem with applications

Every irrational number θ can be approximated to any desired degree of accuracy by rational numbers. In fact, if we truncate the decimal expansion of θ after n decimal places we obtain a rational number which differs from θ by less than 10-n. However, the truncated decimals might have very large denominators. For example, if $$ \theta = \pi - 3 = 0.141592653 \ldots $$ the first five decimal approximations are 0.1, 0.14, 0.141, 0.1415, 0.14159. Written in the form a/b, where a and b are relatively prime integers, these rational approximations become $$ \frac{1} {{10}},\frac{7} {{50}},\frac{{141}} {{1000}},\frac{{283}} {{100,000}}. $$ On the other hand, the fraction 1/7 = 0.142857 … differs from θ by less than 2/1000 and is nearly as good as 141/1000 for approximating θ, yet its denominator 7 is very small compared to 1000.
Defects in pro-apoptotic genes, Bim or Bax/Bak, cause accumulation of TCRβhi DN4 cells in thymus (HEM4P.241)

Regulated induction of apoptosis during thymocyte development is critical to prevent the generation of self-reactive T cells whilst maintaining a repertoire of T cells that can promote protective immunity. Although the pro-apoptotic Bcl-2 family member Bim has been shown to promote apoptotic negative selection of self-reactive thymocytes, the role of Bim in this process is controversial. Here, we have investigated the role of Bim and downstream mediators Bax and Bak on thymocyte selection. Surprisingly, the absence of Bim results in a striking accumulation of DN4 cells with surface TCRβhi feature in the thymus. Similar results were observed in mice with a T cell specific loss of Bax in a Bak knock out background. DN4 cells from Bim-/- or LckCreBaxfl/flBak-/- mice cultured with OP9-DL1 cells largely failed to generate DP cells relative to WT DN4 cells. Further, using a dLckCre system, in which Cre is expressed late in the DP stage, revealed that conditional knock out of Bim or Bax did not result in an accumulation of DN4-TCRβhi cells. Combined, these data suggest that accumulation of DN4-TCRβhi cells in either Bim-/- or LckCreBaxfl/flBak-/- are the result of cells having failed negative selection that downregulate CD4 and CD8 coreceptors. Such a strategy would inherently limit their TCR avidity and reduce their potential for autoreactivity. Our current studies are examining the persistence and location of DN-TCRβhi cells in the periphery of Bim-/- or LckCreBaxfl/flBak-/- mice.
Molecular recognition in the activation of human blood coagulation factor X.

Abstract Factor X can be activated by the extrinsic activation complex (factor VIIa:tissue factor), the intrinsic activation complex (factor IXa:factor VIIIa) and by an enzyme from Russell's viper venom (RVV-X). To identify the regions on the surface of factor X that mediate its association with these three activators, we have prepared 21 synthetic peptides representing 65% of the primary structure of factor X. Only 3 of the 21 peptides inhibited the rate of factor X activation, indicating the regions represented by these three peptides are involved in factor X association. Using purified components, the rate of factor Xa formation was inhibited in a dose-dependent manner by these three peptides with the same relative potency of inhibition in each of the activation systems. The observed relative potencies were: peptide 267-283 greater than or equal to peptide 284-303 greater than peptide 417-431. Kinetic analyses indicated that the three peptides inhibited factor X activation in a non-competitive manner, and in mixed inhibitor assays the peptides were shown to be mutually exclusive of one another. In coagulation-based assays, the potency of inhibition by each peptide was decreased. However, in Russell's viper venom-X-initiated assays peptide 417-431 was the best inhibitor. Fab fragments of antibodies raised to these peptides and affinity purified on factor X-agarose columns inhibited both the purified and coagulation-based assays in a dose-dependent manner. Using the x-ray crystal structure of chymotrypsinogen as a model, these three peptides were found to be located spatially close to one another on the surface of factor X and opposite to the region where factor X is cleaved for activation. These data are consistent with a model in which the three activators combine with factor X through a recognition site composed of multiple loci that is distal to the potential cleavage site. This interaction aligns the active sites of these three enzymes in the correct orientation to cleave factor X at the same arginyl-isoleucyl bond.
MVDR based feature extraction for robust speech recognition

Describes a robust feature extraction method for continuous speech recognition. Central to the method is the minimum variance distortionless response (MVDR) method of spectrum estimation and a feature trajectory smoothing technique for reducing the variance in the feature vectors. The above method, when evaluated on continuous speech recognition tasks in a stationary and moving car, gave an average relative improvement in WER of greater than 30%.
Geology and tin-greisen mineralization of the Akash granite, northern Arabian Shield

Abstract The western margin of the postorogenic Akash granite, 30 km E of Ha'il in the northern Arabian Shield, is greisenized and contains anomalous concentrations of Sn. The pluton intrudes metamorphic and intrusive rocks, and crops out as a 10 by 15 km elliptical body with its long axis oriented N. It consists predominantly of metaluminous alkali-feldspar granite or syenogranite, with accessory biotite and muscovite, and traces of fluorite. Greisenization extends discontinuously in a zone at least 3 km long parallel to the western contact, and along E-trending hematitic quartz veins for more than 2 km from the contact. The veins occupy fractures that were probably conduits for ascending mineralizing fluids. Within about 20 m of the contact, they are enclosed in quartz—white mica greisen containing hematite, fluorite, and locally, topaz and cassiterite. Composite chip samples from the greisenized zone have an average Sn content of 710 ppm, and a maximum of 1600 ppm. Anomalous values for Zn, Fe, Mn, Mo, Bi and Cu also occur, but none of the samples contain detectable W. Three samples of hematitic quartz averaged 126 ppm Sn, and one contained 200 ppm W.
Performance Analysis of Collaborative Hybrid-ARQ Incremental Redundancy Protocols Over Fading Channels

Future wireless communication systems are expected to rely heavily on spatial diversity for mitigation of fading impairments. In scenarios where practical constraints prevent the collocation of multiple antennas on a single user terminal, collaboration between single-antenna nodes becomes the only viable solution. Among cooperative schemes, Collaborative ARQ transmission protocols, prescribing cooperation only upon erroneous decoding by the destination, emerge as an interesting solution in terms of achievable spectral efficiency. In this paper, an information theoretical approach is presented for assessing the performance of Collaborative Hybrid-ARQ protocol based on Incremental Redundancy. Upper and lower bounds for the expected number of retransmissions and the average throughput are derived in explicit form, for any number of relays. Numerical results are presented to supplement the analysis and give insight into the performance of the considered scheme.
Botryococcus braunii carbon/nitrogen metabolism as affected by ammonia addition

Carbon metabolism in photosynthesizing and respiring cells of Botryococcus braunii was radically changed by the presence of 1 mM NH4Cl in the medium, when the so-called “resting state” previously had been subjected to a nitrogen-deficient medium. Ammonia addition to the algae photosynthesizing with 14C-labelled HCO3-almost completely inhibited the synthesis of 14C-labelled botryococcenes and other hexane-extractable compounds, and also inhibited the formation of insoluble compounds; however, it resulted in a large increase in the synthesis of alanine, glutamine, other amino acids, and especially of 5-aminolevulinic acid. Total CO2 fixation decreased about 60% and O2 evolution decreased more than 50%.
Medical students' activities on core surgical clerkships

Abstract Two studies of surgical clerkships were conducted at the four affiliated hospital sites of Case Western Reserve University School of Medicine. One study consisted of 1015 hr of structured observations of surgical clerks' activities during January 1975. The purposes were to record their activities on the wards, to indicate the degree of responsibilities exercised in patient care, and to identify health professionals with whom they worked. Observation data were summarized in 1 4 -hr units according to categories of patient contact, scheduled group experiences, and off-ward activities which included reading, meals, and miscellaneous activities. The second study analyzed tasks and activities experienced by students serving in three successive surgical clerkship rotations at each of the four training sites. A 196-item inventory developed by the clerkship directors to elicit information about the types of activities and level of student participation in these experiences was completed by 77 medical student clerks. Tasks were analyzed according to levels of participation, ranging from no experience to performance without supervision. Frequency distributions were generated for each item. The data have been used to profile each surgical training site and to assess the congruence between faculty perceptions and expectations of student clerkship activities and the actual experiences. Plans for refinement of goals and objectives, the evaluative forms and procedures, and further monitoring of these learning experiences are underway.
FOXO/4E-BP signaling in Drosophila muscles regulates organism-wide proteostasis during aging

The progressive loss of muscle strength during aging is a common degenerative event of unclear pathogenesis. Although muscle functional decline precedes age-related changes in other tissues, its contribution to systemic aging is unknown. Here, we show that muscle aging is characterized in Drosophila by the progressive accumulation of protein aggregates that associate with impaired muscle function. The transcription factor FOXO and its target 4E-BP remove damaged proteins at least in part via the autophagy/lysosome system, whereas foxo mutants have dysfunctional proteostasis. Both FOXO and 4E-BP delay muscle functional decay and extend life span. Moreover, FOXO/4E-BP signaling in muscles decreases feeding behavior and the release of insulin from producing cells, which in turn delays the age-related accumulation of protein aggregates in other tissues. These findings reveal an organism-wide regulation of proteostasis in response to muscle aging and a key role of FOXO/4E-BP signaling in the coordination of organismal and tissue aging.
Quality of life in pediatric epilepsy: Considerations for measurement and use.

Pediatric health-related quality of life (HRQOL) is a multifactorial construct that covers multiple domains of functioning, such as social, emotional, and school performance. It is not surprising that previous studies have linked seizures and antiepileptic drug side effects to HRQOL.1 Recent studies have revealed that parent-endorsed stress, worry, fears, and perceived stigma are predictors of parent-reported HRQOL in children with new-onset epilepsy.2 Ferro3 conducted a meta-analysis and reported seizure variables, maternal anxiety, presence of a comorbidity, and family socioeconomic status as negative predictors of HRQOL in youth with epilepsy. Duration of epilepsy as a risk factor was moderated by the source of informant (parent vs child). HRQOL is indeed recognized as an important patient-reported outcome, one with modifiable predictors.
The Development of Goal Plans of Action in the Narration of a Picture Story.

The construction of coherent narrations of events in a picture storybook by children was studied. A causal network discourse analysis (Trabasso, van den Broek, & Suh, 1989) was applied to the narrations by children, 3, 4, 5, and 9 years in age, and adults, 20 years and older. The analysis was successfully applied at the clausal level by deriving interacting causal network representations for the perspective of each character in each of the narrations. The structure and content of the network representation of the main character were analyzed in detail. The analysis indicated that 9‐year‐olds and adults narrate according to a hierarchical goal plan of action. It also showed striking developmental differences from age 3 to 5. The 3‐year‐old children described states and neutral outcomes that are unrelated to the central theme. The 4‐year‐olds, in contrast, encoded actions relevant to the central theme but omitted goals and purposes. The 5‐year‐olds added these purposes to attempts. Coherence in the narratio...
SEM and shrinkage analyses of southern pine wood following pyrolysis.

Samples of Southern Pine (Pinus spp.) charred to 250°, 300°, 350°, 400° or 600°C in a flowing nitrogen atmosphere at rates of 1°, 10° and 50°C/min were examined using the scanning electron microscope to quantify changes in cross-sectional tracheid dimensions. The disappearance of discrete cell wall layers was time-dependent as opposed to strictly temperature-dependent. Tracheid diameters decreased in response to temperature and charring rate. Double cell wall thickness values also decreased in response to charring. This shrinkage was nearly isotropic. Below 300°C, latewood cells were more stable than earlywood cells. Above 300°C, the reverse was true. This was attributed to the probable circumferential arrangement of cellulose, hemicellulose, and lignin within the cell wall. The highest rate of thermal degradation was between 300° and 350°C.
Convergence and Downwelling at a River Plume Front

Abstract The small-scale structure of the circulation and hydrography at the frontal boundary of the Connecticut River plume in Long Island Sound has been resolved using a novel combination of instruments: a towed acoustic Doppler current profiler (ADCP) and a rigid array of current meters and conductivity–temperature sensors. Observations were made during the latter half of the eastward ebb tide, when the river plume was well established and the front was moving to the west at approximately 0.3 m s−1. Two across-front transects revealed a horizontal convergence rate in the across-front velocity components at 0.6 m of 0.05–0.1 s−1. This was associated with a salt-induced horizontal density gradient of 10−2 kg/m4. Observations obtained during a period in which the towed ADCP was caught in the zone of maximum surface convergence showed significant downwelling with a near-surface maximum of 0.2 m s−1. Vertical velocities of this magnitude are consistent with observed magnitudes of the convergence rate at 0.6...
Model nucleation and growth studies of nanoscale oxide coatings suitable for modification of microcellular and nano-structured carbon

Abstract In this paper, a detailed study of the nucleation and growth of plasma assisted oxide coatings on model graphitic substrates has been performed. The surface chemistry and morphology of these films (as they grow on graphite) have been monitored using X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). It is shown that oxide coatings start as islands having average height of 3–5 nm. The density and lateral size of these islands grow to form complete layers. Therefore complete and smooth coverage can be obtained with a film thickness in the range of a few nanometers (3–5 nm). The coating chemical composition is identical to SiO2. Detailed XPS analysis during overlayer growth reveals the presence of strong –Si–C– bonds at the graphite–coating interface. This is an important finding that can help to predict the mechanical, thermal and other functional properties of the interface. The durability of this coating at high operating temperatures has been investigated, and it is found to withstand up to 1000 °C heat treatments in argon environment.
INTERCELLULAR COMMUNICATION AND TISSUE GROWTH : I. Cancerous Growth

Intercellular communication was examined with intracellular electrical techniques in primary and transplanted rat liver cancers. Normal liver cells communicate rather freely with each other through permeable junctional membranes. Cancer liver cells show no communication at all; their surface membrane is a strong barrier to diffusion all around the cell. Cancer cells induce alterations in membrane permeability in normal liver cells; communication among the latter is markedly reduced when cancer cells grow near them.
Using Computer Modelling as a Tool for Self-directed Learning in Financial Economics

Abstract This paper presents an example of the use of a computer simulation model as a platform for self-directed student learning in the field of financial economics. Students use the simulation model as a vehicle to analyse expected outcomes for a typical capital investment as influenced by a probabilistically distributed set of possible future macroeconomic variables. The technique may be used to analyse a wide range of financial decisions, but in this example we use it to inform a decision regarding financing structure in a real estate investment.
An automatic procedure for the symmetry blocking of semi-empirical Hamiltonians

Abstract We present a procedure for the block-diagonalisation of a Fock matrix which does not require explicit details of the point group of the molecule concerned. The method consists of two parts: (a) the trial eigenvectors determined at the start of a semi-empirical calculation are analysed to give an initial set of symmetry-adapted functions; and (b) these symmetry-adapted functions are modified by testing for a correct blocking in the initial diagonalisation of the Fock matrix. Only minor modifications to existing semi-empirical programs are needed for the inclusion of the routines to perform the algorithm.
Customer-focused adaptation in New York City hotels: exploring the perceptions of Japanese and Korean travelers

Abstract Tourism providers must accommodate culturally based guest needs in order to tap into the increasingly lucrative market of international travelers. Although there have been several normative efforts to delineate the expectations of Japanese and Korean travelers to the United States, there is little or no research relating these guests’ satisfaction with hotel efforts at customer-focused adaptations. Preliminary findings based on the small sample studied suggest that when compared to American-operated hotels, Japanese- and Korean-operated hotels, in general, make a greater effort to accommodate the needs of Japanese and Korean guests, respectively. Product specific adaptations such as providing menus, magazines and hotel directories in the guest's native language can make the difference in creating a satisfied traveler.
Simulation of Short‐Term Management Actions to Prevent Oxygen Depletion in Ponds

This study examined possible changes in dissolved oxygen concentration resulting from various short-term management actions that can be undertaken in response to cloudy conditions. The management actions were examined with a computer model of water quality in a pond, and include nutrient enrichment (fertilization, pH adjustment), water level control, and water exchange. Results of these simulations indicated that general management strategies directed at increasing nutrient availability were the least effective in counteracting the effect of the increased cloud cover. Flushing and reducing the water level in the pond were considerably more effective short-term management actions. Areas for field research were suggested to confirm the effectiveness of the various strategies.
Harm Reduction, Crystal Methamphetamine, and Gay Men

This article describes changing definitions and models of harm reduction along with their practice applications. This article then provides an overview of harm reduction strategies for methamphetam...
Computer Aided Geometric Design of Two-Parameter Freeform Motions

This paper brings together the notion of analytically defined two-parameter motion in Theoretical Kinematics and the notion of freeform surfaces in Computer Aided Geometric Design (CAGD) to develop methods for computer aided design of two-parameter freeform motions. In particular, a rational Bezier representation for two-parameter freeform motions is developed. It has been shown that the trajectory surface of such a motion is a tensor-product rational Bezier surface and that such a kinematically generated surface has a geometric as well as a kinematic control structure. The results have not only theoretical interest in CAGD and kinematics but also applications in CAD/CAM and Robotics.
Inhibitory effects of archetypical nucleic acid ligands on the interactions of HIV-1 nucleocapsid protein with elements of Ψ-RNA

Disrupting the interactions between human immunodeficiency virus type 1 (HIV-1) nucleocapsid (NC) protein and structural elements of the packaging signal (Ψ-RNA) could constitute an ideal strategy to inhibit the functions of this region of the genome leader in the virus life cycle. We have employed electrospray ionization (ESI) Fourier transform mass spectrometry (FTMS) to assess the ability of a series of nucleic acid ligands to bind selected structures of Ψ-RNA and inhibit their specific interactions with NC in vitro. We found that the majority of the ligands included in the study were able to form stable non-covalent complexes with stem–loop 2, 3 and 4 (SL2–4), consistent with their characteristic nucleic acid binding modes. However, only aminoglycosidic antibiotics were capable of dissociating preformed NC•SL3 and NC•SL4 complexes, but not NC•SL2. The apparent specificity of these inhibitory effects is closely dependent on distinctive structural features of the different NC•RNA complexes. The trends observed for the IC50 values correlate very well with those provided by the ligand binding affinities and the dissociation constants of target NC•RNA complexes. This systematic investigation of archetypical nucleic acid ligands provides a valid framework to support the design of novel ligand inhibitors for HIV-1 treatment.
The synthesis and PMR study of certain 3-substituted 2-(β-D-Ribofuranosyl)indazoles

The synthesis of 3-cyano-2-(β-D-ribofuranosyl)indazole (4) has been accomplished by a condensation of N-trimethylsilyl-3-cyanoindazole (1) with 2,3,5-tri-O-aeetyl-D-ribofuranosyl bromide (2) followed by subsequent deacetylation. The reactivity of the 3-cyano group was demonstrated by the conversion of 4 to 2-(β-D-ribofuranosyl)indazole-3-carboxamide (5) and 2-(β-D-ribofuranosyl)indazole-3-thiocarboxamide (6). The site of ribosylation and the assignment of anomeric configuration for 4 is discussed. The magnetic anisotropy effect of the exocyclic group at C3 on the anomeric proton as determined by pmr spectroscopy is discussed.
STRATEGIES FOR THE PREOPERATIVE EVALUATION OF THE HYPERTENSIVE PATIENT

Because hypertension affects at least 50 million residents in the United States, 31,55 the detection, evaluation, and perioperative treatment of hypertension are common everyday clinical problems faced by the anesthesiologist. Hypertension affects the anesthesiologist's choice of drugs, monitoring, and postoperative planning. Therefore, a basic understanding of the disease, its implications, and treatment is necessary for the care of the surgical patient. Part of the dilemma has been in defining what constitutes hypertension and what level of blood pressure requires intervention. Even more important from the standpoint of the anesthesiologist is at what level of hypertension and under what circumstances should further workup of the patient be completed before surgery. The article reviews current clinical knowledge and outlines a rational strategy for dealing with this recurring clinical problem.
Vegetation distribution across the early Eocene depositional landscape from palynological analysis

Abstract The usefulness of palynomorphs in reconstruction of vegetation in the pre-Quaternary has been hampered by uncertainty in distinguishing local from transported palynomorphs. Analysis of palynomorph transport in modern settings suggests that the importance of transported palynomorphs in a nonmarine depositional environment depends on its geomorphologic characteristics. Aerial transport will be a significant source of palynomorphs only if the environment is open. Waterborne transport depends on the access of water to the depositional environment. The importance of transported palynomorphs relative to the local palynomorphs varies among depositional environments, and can be assessed in each case. In the early Eocene of the Bighorn Basin (Wyoming), five depositional environments (pond, levee/crevasse splay, swamp margin, swamp, reduced floodplain) contain distinct palynomorph assemblages as measured by canonical variates analysis. The relative importance of transported palynomorphs is greatest in the pond, and progressively decreases in the levee, reduced floodplain, swamp margin, and swamp. In the pond, reworked marine dinoflagellates and bisaccate conifer pollen are high in abundance, reflecting transport. Taxodiaceae and Alnus are rare, and did not inhabit the vegetation surrounding the pond. Corylus , ulmaceous, and fagaceous (?) taxa lived surrounding the pond. The levee, like the pond, contains marine dinoflagellates and bisaccate pollen, but in lower numbers than the pond. Pollen of Fagaceae, Alnus (locally), and pteridophyte spores reflect the levee vegetation. The abundance of pteridophyte spores results from their ability to respond quickly to substrate disturbance. Reduced floodplains contain pteridophytes, Taxodiaceae, Platycarya , and Plicatopollis . Swamp margin and swamp palynofloras are similar and are dominated by local plants: Taxodiaceae, Alnus, Platycarya, Sparganiaceaepollenites , and locally Pistillipollenites . The palynofloral data is consistent with the megafloral record in the same environments; this supports the vegetation reconstruction from palynology.
Central role of a bacterial two-component gene regulatory system of previously unknown function in pathogen persistence in human saliva

The molecular genetic mechanisms used by bacteria to persist in humans are poorly understood. Group A Streptococcus (GAS) causes the majority of bacterial pharyngitis cases in humans and is prone to persistently inhabit the upper respiratory tract. To gain information about how GAS survives in and infects the oropharynx, we analyzed the transcriptome of a serotype M1 strain grown in saliva. The dynamic pattern of changes in transcripts of genes [spy0874/0875, herein named sptR and sptS (sptR/S), for saliva persistence] encoding a two-component gene regulatory system of unknown function suggested that SptR/S contributed to persistence of GAS in saliva. Consistent with this idea, an isogenic nonpolar mutant strain (ΔsptR) was dramatically less able to survive in saliva compared with the parental strain. Iterative expression microarray analysis of bacteria grown in saliva revealed that transcripts of several known and putative GAS virulence factor genes were decreased significantly in the ΔsptR mutant strain. Compared with the parental strain, the isogenic mutant strain also had altered transcripts of multiple genes encoding proteins involved in complex carbohydrate acquisition and utilization pathways. Western immunoblot analysis and real-time PCR analysis of GAS in throat swabs taken from humans with pharyngitis confirmed the findings. We conclude that SptR/S optimizes persistence of GAS in human saliva, apparently by strategically influencing metabolic pathways and virulence factor production. The discovery of a genetic program that significantly increased persistence of a major human pathogen in saliva enhances understanding of how bacteria survive in the host and suggests new therapeutic strategies.
Content delivery in the MobilityFirst future Internet architecture

This paper presents a detailed description of content delivery techniques used in the proposed MobilityFirst (MF) clean-slate future Internet architecture now under development. The MF architecture addresses the requirements of mobile content delivery using the following basic design elements: (1). mapping of human readable names to “flat” globally unique identifiers (GUID's) which are used as the basis for all communication services; (2). a global name resolution service (GNRS) for dynamic binding of GUIDs to network locators; and (3). a hop-by-hop storage-aware transport scheme that exploits in-network storage and copes with characteristics of wireless medium. Technical details for content naming and addressing are given, along with an explanation of methods for publishing, locating and delivering content within this framework. It is shown that the architecture supports seamless migration of content, efficient retrieval and support for optional in-network caching. Ongoing work on a real-time prototype implemented on the ORBIT testbed and the GENI experimental network is also presented.
Heme catabolism in cultured hepatocytes: evidence that heme oxygenase is the predominant pathway and that a proportion of synthesized heme is converted rapidly to biliverdin.

Abstract Heme oxygenase has been considered to be involved in the predominant pathway of heme degradation in vivo. However, alternative pathways involving cytochrome P -450 reductase, and lipid peroxidation, have previously been demonstrated in vitro, and studies with cultured rat hepatocytes were interpreted to show a majority of endogenous hepatic heme breakdown by non-heme oxygenase pathways. To clarify the pathway of heme breakdown in hepatocytes and the role of heme oxygenase in this process, cultured hepatocytes were pre-labelled with 5-[5- 14 C]aminolevulinate ([ 14 C]ALA). Radioactivity in heme, carbon monoxide, and bile pigments was measured for 8–24 h after the removal of [ 14 C]ALA. In cultured chick embryo hepatocytes, which lack biliverdin reductase, the rate of production of biliverdin IXa was closely similar to the rate of ctabolism of exogenous heme and radioactivity in carbon monoxide and biliverdin IXa was similar to the loss of radioactivity from endogenous heme. These results support the conclusion that heme breakdown occurred predominantly, if not solely, by heme oxygenase. Also, no evidence of non-heme oxygenase pathways was found in the presence of tin protoporphyrin, an inhibitor of heme oxygenase or mephenytoin, an inducer of both cytochrome P -450 and heme oxygenase. Similarly, in untreated cultured rat hepatocytes, radioactivity in carbon monoxide corresponded with loss of radioactivity in endogenous heme. In other experiments with chick hepatocyte cultures, rates of heme synthesis and breakdown were measured, and data were fitted to various models of hepatic heme metabolism. The results observed were consistent only with models in which an appreciable fraction (control cells, 17%, mephenytoin treated cells, 41%) of the newly synthesized heme was degraded rapidly to biliverdin.
Computerized estimation of the lung volume removed during lung volume reduction surgery.

Rationale and Objectives This study was designed to develop an automated method for estimating lung volume removed during lung volume reduction surgery (LVRS) using computed tomography (CT). Materials and Methods The CT examinations of six patients who underwent bilateral LVRS were analyzed in this study. The resected lung tissue (right and left) was weighed during pathologic examination. An automated computer scheme was developed to estimate the lung volume removed using the CT voxel values and lung specimen weight. The computed fraction of lung volume removed was evaluated across a range of simulated surgical planes (ie, other than parallel to the CT image plane) and CT reconstruction kernels, and it was compared with the surgeons’ postsurgical estimates. Results The computed fraction of the lung volume removed during LVRS was linearly correlated with the resected lung tissue weight (Pearson correlation = 0.697, P = .012). The computed fraction of lung volume removed ranged from 12.9% to 51.7% of the total lung volume. The surgeons’ postsurgical estimates of lung volume removed ranged from 30% to 33%. The percent difference between the surgeons’ estimates and the computed lung volume removed as a percentage of the surgeons’ estimates ranged from −72.3% to 57.0% with mean absolute difference of 29.7% (±20.7). Conclusion The preliminary findings of this study suggest that the proposed quantitative model should provide an objective measure of lung volume removed during LVRS that may be used to investigate the relationship between lung volume removed and outcome.
Supporting Professional Learning: Beyond Technological Support.

Three main evolutions define the concept of professional learning support. The firstone could be as a result of the dynamic interaction between a new demand for professional learning coming both from the individual and the organisations and a new supply defined mainly by the new possibilities offered by the technologies. The second one could be presented as the adoption of a new paradigm of learning, which integrates the learner as the main actor and the process of knowledge building either by interactions with the environment or by human-human interactions. The last one concerns the concept of professional itself. In this paper Jitol is analysed according to these three evolutions either bydefining the assumptions of this ‘professional learning support’ and by highlighting main results of the JITOL pilot studies. The main issue of this reflection, will lead to anunderstanding that Jitol becomes effective and meaningful through its diverse uses in real settings and that theses uses need to be driven by a collaborative research action.
BIOLOGICAL NITROGEN INFLUX IN AN OHIO RELICT PRAIRIE.

The principal contributors of biologically fixed N in natural grassland ecosystems appear to be asymbiotic bacteria and heterocystous cyanobacteria. The environmental factors of light, moisture, and temperature play important roles in the magnitude of the N2 -fixation activity. Biological N2 -fixation was measured in the Elizabeth's Prairie section of the Lynx Prairie Preserve, Adams County, Ohio, during 15 site visits beginning 29 March through 8 November 1980. In situ N2 -fixation activity was measured using the acetylene-reduction technique. The percentage cover of cyanobacterial colonies (Nostoc sp.) was determined using Point-Frame Analysis. Soil and air temperatures and soil water potentials also were measured. Intact soil cores with a surface cover of Nostoc were collected and returned to the laboratory to quantify the effect of decreasing water potential on the N2 (C2 H2 )ase activity of Nostoc. The N2 (C2 H2 )ase activity of Nostoc on the intact soil cores displayed a linear response of approximately 10% decrease in N2 (C2 H2 )ase activity per one bar decrease in soil water potential. The cyanobacteria contributed almost all of the biologically fixed N at the site until late June. From late June through to mid September, heterotrophic diazotrophs played the major role in the N2 -fixation activity. These changes are attributed to fluctuations in Nostoc sp. colony cover, temperature, and soil water potentials. Extrapolation of the measured rates, and assuming an average of 10 hr per day of activity, Nostoc sp. is shown to have contributed 4.60 ± 1.17 kg N ha-1 yr-1 . Heterotrophic diazotrophs contributed an estimated 3.19 ± 1.18 kg N ha-1 yr-1 . The total biological N2 -fixation for the site was calculated at 8.2 ± 2.55 kg N ha-1 yr-1 , from additional measurements which estimated total diazotrophic activity of the site. These rates of N2 -fixation are among the highest reported for temperate grassland habitats.
Methionine inhibits cellular growth dependent on the p53 status of cells.

Abstract Background Methionine, an essential amino acid, is important for normal growth and development, as it is required for both protein and polyamine synthesis as well as in methylation reactions. It has been reported that high concentrations of methionine inhibit cellular growth and gene expression in the human breast tumor-derived MCF-7 cells. These effects are thought to be mediated by the modulation of p53. However, the generalizability of this observation and the precise role of p53 in methionine-induced growth suppression needs to be determined. Methods To determine if the inhibition of cell growth by methionine applies to other cell lines and to characterize further the role of p53 in methionine-induced growth suppression, we have assessed the effects of methionine on cellular growth and proliferation and p53 expression in cells expressing native p53, eg, breast cancer MCF-7 cells and prostate cancer LNCaP cells, and also in cells expressing a mutated (point) form of p53, eg, prostate cancer DU-145 cells. These cell lines were treated with varying concentrations of l -methionine. The effects of l -methionine on cell growth were assyed by using cell viability assays and immunostaining for Ki-67, a cell proliferation marker. The effects of methionine on p53 expression were assessed by using reverse transcriptase–polymerase chain reaction (RT-PCR), immunohistochemistry, and Western blot analysis. The role of p53 in l -methionine–mediated growth suppression was evaluated using short-interference RNA for p53 (siRNA-p53), immunoprecipitation, and direct DNA sequencing. Results We demonstrated that methionine at a concentration of 1 to 5 mg/mL inhibited the growth of both MCF-7 and LNCaP cells. In association with the inhibition of growth, methionine also inhibited native p53 expression at the mRNA and protein levels, respectively. Furthermore, transfection with siRNA-p53, to knock down p53 expression, increased cell growth and proliferation of the LNCaP cells even when they were exposed to methionine. In contrast, the same treatment did not diminish growth or proliferation of the DU-145 cells. Also, the expression of mutated p53 at the mRNA or protein levels was not altered. Conclusion Our results extend a prior observation to other cell lines and demonstrate that high concentrations of methionine suppress the expression of native but not mutated p53. These inhibitory effects on cellular growth are, in part, due to inhibition of cellular proliferation probably via a p53-dependent pathway.
The Donkey Problem

The Donkey Problem (as I am calling it) concerns the relationship between more and less fundamental ontologies. I will claim that the moral to draw from the Donkey Problem is that the less fundamental objects are merely conventional. This conventionalism has consequences for the 3D/4D debate. Four-dimensionalism is motivated by a desire to avoid coinciding objects, but once we accept that the non-fundamental ontology is conventional there is no longer any reason to reject coincidence. I therefore encourage 4Dists to become even more radical—embrace the Donkey Problem’s conventionalism and deflate the debate between 3Dists and 4Dists.
Comparison of Ancillary Studies in the Detection of Residual Disease in Plasma Cell Myeloma in Bone Marrow

Morphologic determination of residual plasma cell myeloma is often difficult. This study was conducted to evaluate the diagnostic value of several ancillary methods. A total of 121 bone marrow specimens from patients with myeloma after bone marrow transplantation or chemotherapy were studied. Of those, 49 cases were studied by conventional cytogenetics (CC), 86 by flow cytometry (FC), 50 by immunohistochemical analysis, 72 by molecular studies (MS) for immunoglobulin gene rearrangements, and 18 by standard fluorescence in situ hybridization (FISH) study. Of the patients, 70 were found to have residual myeloma. Residual disease was detected in 58 of 70 patients by morphologic examination (detection rate, 83%), 25 of 26 by immunohistochemical analysis (96%), 39 of 54 by FC (72%), 6 of 40 by CC (15%), 6 of 12 by FISH (50%), and 24 of 40 by MS (60%). Among the ancillary studies, immunohistochemical analysis and FC were the most helpful ancillary studies for detection of residual disease in myeloma, with immunohistochemical analysis the most effective single method.
Interpolation Scheme for Energy Bands in Solids

The orthogonalized plane wave method is formulated as an interpolation scheme for use in conjunction with calculations made at symmetry points in the Brillouin zone. The Fourier coefficients of the crystal potential and the matrix components of the Hamiltonian between core functions are treated as parameters to be fitted to other calculations made at symmetry points by such methods as the cellular, orthogonalized plane wave, and augmented plane wave. The interpolation scheme then provides a method for making calculations at a general point in the Brillouin zone. The scheme is most useful for the case of valence and excited states where the wave function on one center overlaps many of its neighbors.
Exposure to Human Immunodeficiency Virus Type I-Specific T Helper Cell Responses before Detection of Infection by Polymerase Chain Reaction and Serum Antibodies

A healthy individual at risk for human immunodeficiency virus type 1 (HIV-1) infection was studied longitudinally for 19 months for evidence of exposure to and infection with HIV. Peripheral blood mononuclear cells (PBMC) were tested at 1, 5, 13, 16, and 19 months for T helper (Th) cell function by in vitro-generated proliferation and interleukin-2 production in response to four synthetic peptides corresponding to env of HIV. PBMC were also tested for proviral DNA using gag primers by the polymerase chain reaction (PCR) at 0, 5, 10, 13, 16, and 19 months. HIV serology by ELISA and p24 antigen and Western blot analyses were done on samples taken at 0, 1, 5, 10, 13, 16, and 19 months. The results indicated that both Th cell tests were positive during months 5-19. In contrast, the PCR and all serologic assays were negative except for month 19, when the assays became positive. These results, based on the longitudinal study of one individual, showed that the Th cell tests can reveal exposure to HIV-1 antigens several months before evidence of viral infection is detected, even by PCR.