cssi/SciSciGPT-SciSciNet huggingface dataset:
A Forced Damped Oscillation Framework for Undulatory Swimming Provides New Insights into How Propulsion Arises in Active and Passive Swimming

A fundamental issue in locomotion is to understand how muscle forcing produces apparently complex deformation kinematics leading to movement of animals like undulatory swimmers. The question of whether complicated muscle forcing is required to create the observed deformation kinematics is central to the understanding of how animals control movement. In this work, a forced damped oscillation framework is applied to a chain-link model for undulatory swimming to understand how forcing leads to deformation and movement. A unified understanding of swimming, caused by muscle contractions (“active” swimming) or by forces imparted by the surrounding fluid (“passive” swimming), is obtained. We show that the forcing triggers the first few deformation modes of the body, which in turn cause the translational motion. We show that relatively simple forcing patterns can trigger seemingly complex deformation kinematics that lead to movement. For given muscle activation, the forcing frequency relative to the natural frequency of the damped oscillator is important for the emergent deformation characteristics of the body. The proposed approach also leads to a qualitative understanding of optimal deformation kinematics for fast swimming. These results, based on a chain-link model of swimming, are confirmed by fully resolved computational fluid dynamics (CFD) simulations. Prior results from the literature on the optimal value of stiffness for maximum speed are explained.
Intracellular Distribution and Intracellular Dynamics of a Spin-Labeled Analogue of Doxorubicin by Fluorescence and EPR Spectroscopy

Fluorescence spectroscopy revealed a dramatic difference between the intracellular distributions of doxorubicin (DOX) and its paramagnetic analogue, ruboxyl (Rb). Modification of the anthracyclin structure by introduction of a paramagnetic label at position 14 in the DOX molecule resulted in reduced DNA binding and enhanced partitioning into phospholipid membranes, as evidenced by the fluorescence-quenching experiments. Higher partitioning into cell membranes resulted in stronger intracellular fluorescence of Rb. In addition, a paramagnetic label on the Rb molecule provided a unique opportunity for an EPR investigation of the drug's intracellular distribution and dynamics. The observed changes in the EPR spectra of drug-containing cells during their life cycle suggested either a progressive release of the intercalated drug, cell membrane fluidization, or both.
Comparative genome sequencing reveals chemotype-specific gene clusters in the toxigenic black mold Stachybotrys

The fungal genus Stachybotrys produces several diverse toxins that affect human health. Its strains comprise two mutually-exclusive toxin chemotypes, one producing satratoxins, which are a subclass of trichothecenes, and the other producing the less-toxic atranones. To determine the genetic basis for chemotype-specific differences in toxin production, the genomes of four Stachybotrys strains were sequenced and assembled de novo. Two of these strains produce atranones and two produce satratoxins. Comparative analysis of these four 35-Mbp genomes revealed several chemotype-specific gene clusters that are predicted to make secondary metabolites. The largest, which was named the core atranone cluster, encodes 14 proteins that may suffice to produce all observed atranone compounds via reactions that include an unusual Baeyer-Villiger oxidation. Satratoxins are suggested to be made by products of multiple gene clusters that encode 21 proteins in all, including polyketide synthases, acetyltransferases, and other enzymes expected to modify the trichothecene skeleton. One such satratoxin chemotype-specific cluster is adjacent to the core trichothecene cluster, which has diverged from those of other trichothecene producers to contain a unique polyketide synthase. The results suggest that chemotype-specific gene clusters are likely the genetic basis for the mutually-exclusive toxin chemotypes of Stachybotrys. A unified biochemical model for Stachybotrys toxin production is presented. Overall, the four genomes described here will be useful for ongoing studies of this mold’s diverse toxicity mechanisms.
Inverse quantum-mechanical control: A means for design and a test of intuition.

The inverse quantum-mechanical control of molecules is studied using the equation of motion for the expectation value of an operator. With this method, a requisite external field is obtained to track exactly a prescribed molecular objective expectation value as a function of time. Applications to diatomic and polyatomic molecules are formulated. While the method is directly applicable as a test of physical intuition, it can in principle be used to design fields for specific objectives including reactive selectivity. Results are presented for position and energy tracking in the hydrogen fluoride molecular system. The numerical calculations show that seemingly benign objective tracks may give rise to singularities in the field
On the variation of cloud condensation nuclei in association with cloud systems at a mountain-top location☆

The measurements of cloud condensation nuclei, CCN, concentration (both in cloud-free air mass and within clouds-interstitial CCN), cloud droplet size distribution and liquid water content are reported for three cloud episodes observed in Mount Mitchell (38°44'05″N, 82°17'15″W, 2038 m MSL - highest peak in eastern U.S.A.) State Park, North Carolina. The comprehensive database is analyzed to understand the temporal variation of the interstitial CCN during air mass transport and mixing and to understand relationship between CCN concentration, aqueous phase chemical composition, and relative humidity during the evaporative stages of a cloud. Large variations in the interstitial CCN concentration (≥200 cm −3 h −1 ) were found to be related to the sampling near the boundary of different air masses. Large temporal interstitial CCN variations that occur near the end of an event are likely due to evaporation. More subtle changes in the CCN concentration (<200 cm −3 h −1 ) were associated with air mass transport. The measured CCN concentrations made in association with the dissipative stage of a cloud event appear to be a function of air mass chemistry and the instantaneous value of relative humidity
Tetrameric structure of mitochondrially bound rat brain hexokinase: A crosslinking study

Rat brain hexokinase (ATP:D-hexose-6-phosphotransferase; EC 2.7.1.1) was derivatized with sulfosuccinimidyl-2-(m-azido-o-nitrobenzamido)ethyl-1,3'-dithiopro pionate (SAND), a photosensitive and cleavable crosslinking agent. The catalytic activity and mitochondrial binding properties of the enzyme were only marginally affected by reaction with SAND. When the derivatized enzyme was bound to liver mitochondria, photolysis resulted in extensive formation of a single crosslinked species with estimated molecular mass 460 kDa. This was determined to contain only hexokinase and thus represents a tetramer of the 116 kDa (apparent molecular mass in gel system used) monomeric enzyme. Although small amounts of tetramer were detected after photolysis of relatively high concentrations of derivatized enzyme in free solution, tetramer formation was greatly enhanced when the enzyme was bound to mitochondria. No evidence of dimeric or trimeric structures was seen even when only a small fraction of the available binding sites on the mitochondrial membrane were occupied. It is thus concluded that tetramer formation is closely linked with binding of the enzyme to the outer mitochondrial membrane and, more specifically, to the pore structure through which metabolites traverse this membrane. It is speculated that a tetrameric structure surrounding the mitochondrial pores may facilitate interactions between the hexokinase reaction and oxidative phosphorylation, mediated by the adenine nucleotides which are common intermediates in these reactions.
Identification of novel cellular genes transcriptionally suppressed by v-src.

Abstract Our aim is to identify cellular genes whose transcriptional suppression by the v- src oncogene contributes directly and specifically to the transformed and tumorigenic phenotype. We used a modified PCR-based subtractive hybridization technique to isolate 9 cDNAs whose abundance in NIH3T3 fibroblasts is decreased 3-15-fold following transformation by the activated oncogene, v- src . Sequence analysis reveals that 3 cDNAs are unlike those in GenBank. The remaining 6 cDNAs are indentical or highly similar to rat helix-destabilizing protein gene (hnRNP Al), mouse CTLA-2α cysteine protease, rat cytochrome c oxidase (COX) VIc subunit, mouse Type I collagen , human gravin and a partial human cDNA (clone A7C09) isolated by random automated sequencing. Northern blot analysis indicates that the basal level of transcripts in untransformed NIH3T3 of all the genes except mouse Type I collagen was at least 10-fold lower than that of HMG Go-A Reductase , which is abundantly transcribed. These data suggest that the down-regulation of some or all of these genes contributes to v- src -induced changes in mitogenic control or cell morphology.
Methods for Retrospective Geocoding in Population Studies: The Jackson Heart Study

The increasing use of geographic information systems (GIS) in epidemiological population studies requires careful attention to the methods employed in accomplishing geocoding and creating a GIS. Studies have provided limited details, hampering the ability to assess validity of spatial data. The purpose of this paper is to describe the multiphase geocoding methods used to retrospectively create a GIS in the Jackson Heart Study (JHS). We used baseline data from 5,302 participants enrolled in the JHS between 2000 and 2004 in a multiphase process to accomplish geocoding 2 years after participant enrollment. After initial deletion of ungeocodable addresses (n = 52), 96% were geocoded using ArcGIS. An interactive method using data abstraction from participant records, use of additional maps and street reference files, and verification of existence of address, yielded successful geocoding of all but 13 addresses. Overall, nearly 99% (n = 5,237) of the JHS cohort was geocoded retrospectively using the multiple strategies for improving and locating geocodable addresses. Geocoding validation procedures revealed highly accurate and reliable geographic data. Using the methods and protocol developed provided a reliable spatial database that can be used for further investigation of spatial epidemiology. Baseline results were used to describe participants by select geographic indicators, including residence in urban or rural areas, as well as to validate the effectiveness of the study’s sampling plan. Further, our results indicate that retrospectively developing a reliable GIS for a large, epidemiological study is feasible. This paper describes some of the challenges in retrospectively creating a GIS and provides practical tips that enhanced the success.
Partition coefficients of low-molecular-weight volatile chemicals in various liquids and tissues

Partition coefficients are required for developing physiologically based pharmacokinetic models used to assess the uptake, distribution, tabolism, and elimination of volatile chemicals in mammals. A gas-phase vial equilibration technique is presented for determining the liquid:air and tissue:air partition coefficients for low-molecular-weight volatile chemicals. This technique was developed from two previously described medium:air methods, relied solely on measurement of chemical concentration in the gas phase, and, compared to earlier work, extends the range of chemicals and tissues examined. Partition coefficients were determined with 0.9% saline, olive oil, and blood, liver, muscle, and fat tissues from rats for 55 compounds. Human blood:air coefficients were determined for 36 compounds and several blood:air values were also determined in the mouse and for one compound in the hamster. An approach is described for predicting the tissue solubilities of untested compounds based on oil:air and saline:air coefficients using regression analyses. A similar approach is used to model fat:air coefficients in terms of oil:air values and to model human blood: air coefficients in terms of rat blood:air coefficients.
A PRACTICAL NOTE ON THE NEOCLASSICAL ECONOMIC‐BASE MARGINAL MULTIPLIER

Computation and usage of my neoclassical economic-base marginal multiplier formula (Merrifield, 1987) is simplified. The note points out the economic parameters that must be estimated with some care and for which rough approximations suffice. It also indicates when the size of the multiplier will be significantly affected by the source of the exogenous stimulus (factor- or output-price change). The traditional bifurcation effort must be supplemented with careful estimates of only a small subset of the other parameters. For most of the simulated parameter combinations, the multiplier based on exogenous factor-price changes differed from the multiplier based on output-price changes by less than 10 percent.
Inviscid melt spinning (IMS) and phase identification of CaOAl2O3MgO fiber

Abstract CaOAl2O3MgO (CAM) fibers were produced using inviscid melt spinning (IMS). Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were used to examine a fiber morphology and identify the non-equilibrium/equilibrium phases in CAM fibers. The SEM of as-spun CAM fibers showed a surface roughness indicating a crystallinity and some porosity due to a gas evolution during fiber processing. The as-spun CAM fibers showed a formation of the non-equilibrium crystalline phases of MgO·Al2O3, CaO·Al2O3 and α-Al2O3, whereas the CAM fibers heat treated at 1000°C for 24 h showed a formation of the equilibrium phases of 3CaO·5Al2O3 and α-Al2O3.
Structure/function of the inhibition of human 3beta-hydroxysteroid dehydrogenase type 1 and type 2 by trilostane.

The human type 1 (placenta, breast tumors) and type 2 (gonads, adrenals) isoforms of 3β-hydroxysteroid dehydrogenase/isomerase (3β-HSD) are key enzymes in biosynthesis of all active steroid hormones. Human 3β-HSD1 is a critical enzyme in the conversion of DHEA to estradiol in breast tumors and may be a major target enzyme for the treatment of breast cancer. 3β-HSD2 participates in the production of cortisol and aldosterone in the human adrenal gland. The goals of this project are to evaluate the role of the 2α-cyano group on trilostane (2α-cyano-4α,5α-epoxy-17β-ol-androstane-3-one) and determine which amino acids may be critical for 3β-HSD1 specificity. Trilostane without the 2α-cyano group, 4α,5α-epoxy-testosterone, was synthesized. Using our structural model of 3β-HSD1, trilostane or 4α,5α-epoxy-testosterone was docked in the active site using Autodock 3.0, and the potentially critical residues (Met187 and Ser124) were identified. The M187T and S124T mutants of 3β-HSD1 were created, expressed and purified. Dixon analyses of the inhibition of wild-type 3β-HSD1, 3β-HSD2, M187T and S124T by trilostane and 4α,5α-epoxy-testosterone suggest that the 2α-cyano group of trilostane is anchored by Ser124 in both isoenzymes. Kinetic analyses of cofactor and substrate utilization as well as the inhibition kinetics of M187T and the wild-type enzymes suggest that the 16-fold higher-affinity inhibition of 3β-HSD1 by trilostane may be related to the presence of Met187 in 3β-HSD1 and Thr187 in 3β-HSD2. This structure/function information may lead to the production of more highly specific inhibitors of 3β-HSD1 to block the hormone-dependent growth of breast tumors.
Tobacco protoplasts differentiate into elongate cells without net microtubule depolymerization

Microtubules (MTs) are important for plant cell morphogenesis because they influence the deposition of cell plate and wall components. It has been observed that tobacco protoplasts contain a disordered MT array in the cortex. Following several days in culture, these protoplasts become elongate cells with an orderly cortical MT array. The transformation of the MT array may occur by net depolymerization of the disordered MTs and repolymerization of MTs into an ordered array, or by movement of the array as an integral unit. To experimentally distinguish between these two possibilities, the drug taxol was used to stabilize MTs. Protoplasts derived from suspension cultured tobacco,Nicotiana tabacum, were grown in a medium containing the two plant hormones α-naphthaleneacetic acid and benzyladenine, in the presence or absence of 10μM taxol. Changes in cell size and shape were quantified using a video image analysis system. Cell elongation had begun within 48h of protoplast conversion, in both treatments, and continued for 7 days. Immunolocalization of tubulin showed that, in the majority of cells, MTs were disorganized immediately following protoplast conversion. After elongation, the MT arrays were observed to have reoriented to an ordered state. Taxol-treated protoplasts were found to elongate faster and to a greater extent than the non-treated controls. Additionally, the cortical array of taxol-treated protoplasts reorganized more quickly. These data indicate that the net depolymerization of disordered cortical MTs is not necessarily required for the differentiation of a protoplast into an elongate cell.
Removable Singularities for Lu=Ψ(u) and Orlicz Capacities

Abstract Suppose L is a second order elliptic differential operator in R d and let α>1. Baras and Pierre have proved in 1984 that Γ is removable for Lu=uα if and only if its Bessel capacity Cap2, α′(Γ)=0. We extend this result to a general equation Lu=Ψ(u) where Ψ(u) is an increasing convex function subject to Δ2 and ∇2 conditions. Namely, we prove that Γ is removable for Lu=Ψ(u) if and only if its Orlicz capacity is zero, that is, the integral ∫B dx Ψ(∫Γ |x−y|2−d ν(dy)) is equal to 0 or ∞ for every measure ν concentrated on Γ, where B stands for any ball containing Γ.
Expression of viral and myelin gene transcripts in a murine CNS demyelinating disease caused by a coronavirus.

C57BI/6N mice develop a CNS demyelinating disease when inoculated intracranially at 4 weeks of age with the A59 strain of mouse hepatitis virus (MHV-A59). In order to explore the virus-host interactions, the histological features of the demyelinating disease were correlated with the spatial and temporal distribution of viral transcripts and the expression of oligodendrocyte-specific genes (myelin basic protein, proteolipid protein, myelin-associated glycoprotein, and 2′, 3′ cyclic nucleotide 3′-phosphohydrolase) in the spinal cord of diseased mice. Three distinct phases in the disease were identified. In the first phase, 1 week postinfection (1 WPI), virus replication was widespread in both gray and white matter but was preferentially occurring in glial cells. In the ventral and dorsal root zones where viral transcripts were most abundant, all myelin gene transcripts were decreased before demyelination was seen. During the second phase of the disease (2–3 WPI), viral transcripts decreased in abundance and became restricted to the white matter. Numerous demyelinating lesions were observed and were characterized by inflammatory cells, paucity of oligodendrocytes, and a profound decrease of all myelin gene transcripts. In the third phase of the disease (4–6 WPI) no viral transcripts were detected, and remyelination began. In the lesions and the tissue surrounding them, transcripts of all myelin genes increased to levels above normal. The increased expression of myelin gene transcripts occurred in a synchronized manner and with a cellular distribution reminiscent of that seen in developmental myelination. These molecular events correlated with efficient remyelination and clinical recovery in this murine demyelinating disease.
Lateral separation of colloids or cells by dielectrophoresis augmented by AC electroosmosis

Colloidal particles and biological cells are patterned and separated laterally adjacent to a micropatterned electrode array by applying AC electric fields that are principally oriented normally to the electrode array. This is demonstrated for yeast cells, red blood cells, and colloidal polystyrene particles of different sizes and ζ-potentials. The separation mechanism is observed experimentally to depend on the applied field frequency and voltage. At high frequencies, particles position themselves in a manner that is consistent with dielectrophoresis, while at low frequencies, the positioning is explained in terms of a strong coupling between gravity, the vertical component of the dielectrophoretic force, and the Stokes drag on particles induced by AC electroosmotic flow. Compared to high frequency dielectrophoretic separations, the low frequency separations are faster and require lower applied voltages. Furthermore, the AC electroosmosis coupling with dielectrophoresis may enable cell separations that are not feasible based on dielectrophoresis alone.
Children's comprehension of complex sentences

Abstract Four tasks were given to children from 4–12 to test their comprehension of complex sentences containing main verbs taking underlying sentences as their complements ( Sally knew that she was early ). In an imperatives task, very young children interpreted only the complement verb and ignored the complex verb. In a short-term memory task, sentences with two negations usually lost the second not in recall. In direct questioning and anomaly-detection tasks, children tended to make pragmatic inferences and excessively depend on knowledge about the world, as opposed to linguistic information. Overall results showed that even sixth graders had not yet attained adult-level comprehension of complex sentences.
Semiempirical calculations of the interaction of a slightly underexpanded jet with a quiescent atmosphere

Retrorocket jet size and structure for scientific instruments soft Mars landing, estimating off- optimum supersonic jet interaction with quiescent atmosphere
Theory of Mind and Language in Children With Cochlear Implants

Thirty children with cochlear implants (CI children), age range 3-12 years, and 30 children with normal hearing (NH children), age range 4-6 years, were tested on theory of mind and language measures. The CI children showed little to no delay on either theory of mind, relative to the NH children, or spoken language, relative to hearing norms. The CI children showed a slightly atypical sequence of acquisition of theory of mind concepts. The CI children's theory of mind performance was associated with general syntactic proficiency more than measures of complement syntax, and with time since implantation more than age at implantation. Results suggest that cochlear implantation can benefit spoken language ability, which may then benefit theory of mind, perhaps by increasing access to mental state language.
Electrically-induced shape changes in cement-based materials

The electromechanical behavior of hardened portland cement paste has been investigated as a function of measurement frequency and DC electrical bias using an interferometric technique. Large field induced shape changes on the order of 100 A have been found in millimeter thick specimens exposed to moisture. In addition, strong hysteresis effects were found on cycling a large AC field. Dry samples were found to exhibit no field-induced deformations. The mechanism underlying this anomalous behavior is believed to be an electro-osmotically induced swelling of the pore structures. Evidence in support of this hypothesis was found by corresponding investigations of porous silica gels.
Effects of the El Niño–southern oscillation on temperature, precipitation, snow water equivalent and resulting streamflow in the Upper Rio Grande river basin

Snowmelt runoff dominates streamflow in the Upper Rio Grande (URG) basin of New Mexico and Colorado. Annual variations in streamflow timing and volume at most stations in the region are strongly influenced by the El Nino-southern oscillation (ENSO) through its modulation of the seasonal cycles of temperature and precipitation, and hence on snow accumulation and melting. After removing long-term trends over the study period (water years 1952-99), the dependence of monthly temperature, precipitation, snow water equivalent (SWE) at snowcourse stations, and streamflow throughout the URG on ENSO was investigated using composite analyses of the detrended residuals and through dependence of the residuals on the Climate Prediction Center southern oscillation index during the preceding summer and fall. The climate of La Nina years was found to differ significantly from either El Nino or neutral years. Moreover, significant climatological ENSO-related effects are confined to certain months, predominantly at the beginning and end of the winter season. In particular, March of La Nina years is significantly warmer and drier than during either El Nino or neutral years, and November of El Nino years is significantly colder and wetter. Differences in temperature and precipitation lead to significant differences in SWE and streamflow in the URG between the three ENSO phases.
Can computers be more intelligent than humans

Humans are not perfect and they make mistakes. For example, humans without computer aided tools would not be able to design VLSI chips larger than 100 transistors. Computers are assisting humans in many aspects of their life. For many years already computers were used for number crunching, office related jobs, etc. More recently computers are used for making intelligent decisions. The methods of computational intelligence are relatively successful, but these methods have to be used with great care. In this presentation advantages and disadvantages of fuzzy and neural networks are presented. It turns out that often popular training algorithms are not capable of tuning neural networks to proper accuracy without losing generalization abilities. Also, abilities of neural networks strongly depend on the used architecture, and surprisingly the most popular architectures usually are least powerful.
Aberrant extracellular and dendritic cell (DC) surface expression of heat shock protein (hsp)70 in the rheumatoid joint: possible mechanisms of hsp/DC-mediated cross-priming.

We describe, in rheumatoid arthritis (RA), abnormalities in the expression and distribution of heat shock protein (hsp) and dendritic cells (DCs) that are conducive to cross-priming and DC cross-talk. As detected by ELISA, inducible (i)hsp70 was dramatically increased in RA synovial fluid (RASF) vs normal human and RA sera and osteoarthritis and gout synovial fluid. Immunoblot analysis of fresh RASF cells revealed marked increases in ihsp70 and activation of its transcription factor heat shock factor-1, compared with fresh normal peripheral blood cells. Flow cytometry and microscopy demonstrated high levels of ihsp70 on the surface of RASF myeloid DCs (but not normal myeloid DCs) that occurred concurrently with hspRs (CD91/CD14). ihsp70 present in RASF exhibited chaperoning potential, as indicated by the capture of ihsp70 present in RASF on the surface of normal DCs. Binding was partially competitively inhibited by excess α 2 -macroglobulin, indicating that hspRs in addition to CD91 participate in the capture process. These data indicate that ihsp70 may chaperone autologous Ags into immature RASF DCs via hspRs, and that cross-talk between DCs coexpressing hsp/hspRs reflects a disease process in RA. The induction of surface ihsp70 on normal cells after sublethal heat stress and the release of ihsp70 from normal DCs after inflammatory stress also suggest that the pattern of ihsp70 expression in RASF occurs in response to sustained stress.
Architectural versus physical solutions for on-chip communication challenges

The growing gap between transistor and global wire speeds in sub-100 nanometer technologies poses numerous challenges to computer architects and circuit designers. This challenge looks to be even more significant in far-future technologies such as molecular-scale wire transmission, whether using carbon nanotubes or quantum dots. While a fixed design scales as its area decreases with feature size reductions, future designs that use a constant area see rapidly increasing global latencies.Two approaches to address these latencies are (1) to use signaling and design techniques to reduce the actual latencies, and (2) to use architectural innovations to reduce the distance that signals must be propagated in the common case. In this talk, after an overview of the communication latency issue, I describe current research that aims to reduce the average distance communicated for processing and memory system signals. For processor designs, I will describe the Static Placement, Dynamic Issue (SPDI) execution model, which allows the compiler to place dependent instructions near one another, and which is being implemented in the TRIPS processor. I will also describe Non-Uniform Caches Access (NUCA) designs, which attempt to reduce average signal distance for cache accesses.
The plant hormone zeatin riboside inhibits T lymphocyte activity via adenosine A2A receptor activation.

Cytokinins are plant hormones that play an integral role in multiple aspects of plant growth and development. The biological functions of cytokinins in mammalian systems are, however, largely uncharacterized. The naturally occurring cytokinin zeatin riboside has recently been demonstrated to activate the mammalian adenosine A2A receptor, which is broadly expressed by various cell types including immune system cells, with the activation of the A2AR playing a role in the regulation of cells involved in both innate and adaptive immunity. We show for the first time that zeatin riboside modulates mammalian immune system activity via an A2AR-dependent mechanism. Specifically, zeatin riboside treatment induces the production of cyclic adenosine monophosphate (cAMP) by T lymphocytes and inhibits the production by CD3+CD4+ T cells of interferon (IFN)-γ, IL-2, tumor-necrosis factor (TNF)-α, IL-4 and IL-13, and the production by CD3+CD8+ T cells of IFN-γ, IL-2 and TNF-α. Additionally, the upregulation of CD25, CD69 and CD40L by activated T lymphocytes is modulated by zeatin riboside. Zeatin riboside treatment also potently inhibits thioglycollate-induced peritoneal leukocytosis. The immunomodulatory activities of zeatin riboside are blocked by co-treatment with the selective A2AR antagonist ZM241385. These data suggest that zeatin riboside possesses therapeutic potential as a mammalian immunomodulatory agent.
The role of fine-needle aspiration biopsy and flow cytometry in the evaluation of persistent neck adenopathy

Abstract BACKGROUND: The role of fine-needle aspiration biopsy (FNAB) and flow cytometry (FCM) in the evaluation of persistent neck adenopathy has not been completely defined. METHODS: All patients who underwent FNAB of an abnormal lymph node from 1990 to 1997 were identified, and the results of FNAB and FCM were correlated with histology or clinical follow-up. RESULTS: FNAB was performed on 133 patients with an abnormal lymph node in the neck. FNAB was malignant in 82 (62%), atypical in 13 (10%), benign in 27 (20%), and nondiagnostic in 11 (8%) patients. FNAB was compared with histologic results in 114 (86%) or with the results of clinical follow-up (average 17 months) in 12 patients (9%). Seven patients (5%) were lost to follow-up. Lymphoma and metastatic carcinoma were diagnosed in 25 (19%) and 76 (57%) patients, respectively. Sensitivity of FNAB and FCM was 96% and 100%, respectively, and specificity was 58% and 100%, respectively. Patients with Hodgkin’s lymphoma accounted for 80% of false negative FCM results. FCM was nondiagnostic in 3 of 34 patients (9%). Definitive subclassification of lymphoma was accomplished in only 3 of 17 (18%) patients in whom FCM was performed. CONCLUSIONS: FNAB is reliable in identifying metastatic disease, non-Hodgkin’s lymphoma, and reactive lymphadenopathy in the neck. FNAB and FCM still have a limited role in definitive diagnosis of Hodgkin’s lymphoma and classification of non-Hodgkin’s lymphoma, underscoring the importance of excisional biopsy.
The benefit of pre- and post-challenge urine heavy metal testing: part 2.

Measuring heavy metal levels in the urine is an accepted method for assessing the presence of a heavy metal burden in an individual. Random samples (without a flushing agent) are excellent for showing current exposures, as they reflect the level of heavy metals in the bloodstream during the hours immediately before bladder voiding. Samples taken after using a heavy metal mobilizing agent are a reflection of total body burden. Part 1 reviewed the benefits of doing pre-flush (baseline) testing utilizing the published Centers for Disease Control (CDC) heavy metal normal ranges for interpretation that allow the clinician to identify current exposures to lead and mercury and to identify cadmium toxicity. In part 2 the benefits of doing both pre- and post-challenge testing are reviewed. Information gleaned from performing both tests is unparalleled in allowing the clinician to identify which chelating agent will be most effective for the patient. If oral agents are employed, then possible absorption problems can be identified. Since none of these benefits are realized with only post-flush testing, it is recommended that clinicians do heavy metal testing both before and after a challenge with an effective and proven heavy metal mobilizing agent. The pitfalls of oral chelation in the case of malabsorption syndromes, such as gluten intolerance, are also discussed. (Altern Med Rev 2009;14(2):103-108)
The crystal structure of a self-activating G protein alpha subunit reveals its distinct mechanism of signal initiation

In animals, heterotrimeric guanine nucleotide–binding protein (G protein) signaling is initiated by G protein–coupled receptors (GPCRs), which activate G protein a subunits; however, the plant Arabidopsis thaliana lacks canonical GPCRs, and its G protein a subunit (AtGPA1) is self-activating. To investigate how AtGPA1 becomes activated, we determined its crystal structure. AtGPA1 is structurally similar to animal G protein a subunits, but our crystallographic and biophysical studies revealed that it had distinct properties. Notably, the helical domain of AtGPA1 displayed pronounced intrinsic disorder and a tendency to disengage from the Ras domain of the protein. Domain substitution experiments showed that the helical domain of AtGPA1 was necessary for self-activation and sufficient to confer self-activation to an animal G protein a subunit. These findings reveal the structural basis for a mechanism for G protein activation in Arabidopsis that is distinct from the well-established mechanism found in animals.
Biopsychosocial aspects of AIDS

To treat AIDS patients effectively, clinicians must be familiar with the biopsychosocial aspects of the illness.
A general model of wireless interference

We develop a general model to estimate the throughput and goodput between arbitrary pairs of nodes in the presence of interference from other nodes in a wireless network. Our model is based on measurements from the underlying network itself and is thus more accurate than abstract models of RF propagation such as those based on distance. The seed measurements are easy to gather, requiring only O(N) measurements in an N-node networks. Compared to existing measurement-based models, our model advances the state of the art in three important ways. First, it goes beyond pairwise interference and models interference among an arbitrary number of senders. Second, it goes beyond broadcast transmissions and models the more common case of unicast transmissions. Third, it goes beyond homogeneous nodes and models the general case of heterogeneous nodes with different traffic demands and different radio characteristics. Using simulations and measurements from two different wireless testbeds, we show that the predictions of our model are accurate in a wide range of scenarios.
Coenzyme B12-dependent ribonucleotide reductase: evidence for the participation of five cysteine residues in ribonucleotide reduction.

Ribonucleoside triphosphate reductase (RTPR) from Lactobacillus leichmannii catalyzes the conversion of ribonucleotides to 2'-deoxyribonucleotides and requires adenosylcobalamin (AdoCbl) as a cofactor. Recent cloning, sequencing, and expression of this protein (Booker, S., & Stubbe, J. (1993) Proc. Natl. Acad. Sci. U.S.A. 90,8352-83561 have now allowed its characterization by site-directed mutagenesis. The present study focuses on the role of five cysteines postulated to be required for catalysis. The choice of which of the ten cysteines of RTPR were to be mutated was based on extensive studies on the Escherichia coli ribonucleoside diphosphate reductase. Despite the differences between these two reductases in primary sequence, quaternary structure, and cofactor requirements, their mechanisms are strikingly similar. The mutagenesis studies reported herein further suggest that the complex role of the five cysteines is also very similar. A variety of single and double mutants of RTPR were prepared (C731S, C736S, C731 and 7368, C 1 19S, C419S, C408S, and C305S), and their interaction with the normal substrate (CTP) was characterized under several sets of conditions. Mutants C731S, C736S, and C731 and 7368 all catalyzed the formation of dCTP at rates similar to those of the wild-type (wt) enzyme in the presence of the artificial reductant DTT. In the presence of the in vivo reducing system (thioredoxin, thioredoxin reductase, and NADPH), however, each of these mutants catalyzed the formation of only 0.6-0.8 dCTPs per mole of enzyme. The inability of these mutants to catalyze multiple turnovers with respect to the in uivo reducing system suggests that their function might be to transfer reducing equivalents from thioredoxin into the active site disulfide of the reductase. Mutants C119S and C419S were targeted as being the active site cysteines, the ones which directly reduce the ribonucleotide substrate. As expected, neither of these mutants catalyzed the formation of dCTP. However, they did catalyze a time-dependent formation of cytosine, destruction of the cofactor, and the appearance of a chromophore associated with the protein-all phenotypes previously observed for the corresponding active site cysteines of the E. coli reductase. Mutant C408S was unable to catalyze dNTP production or cytosine release. Moreover, it was ineffective in catalyzing two additional reactions which are unique to this enzyme: the exchange of tritium from the 5' hydrogens of AdoCbl with H20 and the destruction of AdoCbl under anaerobic conditions to give 5'-deoxyadenosine and cob(I1)alamin. These results are consistent with the role of this cysteine as the protein radical responsible for initiating catalysis.
Significant Impacts of the Water Level and Human Intervention on the Natural Habitats and Breeding Waterbirds in Marmara Lake

Habitat cover and change were analysed in the Marmara Lake to investigate the effects of water level and human intervention on the natural habitats and breeding waterbirds. Breeding Birds Surveys were applied to investigate breeding waterbirds and their breeding activities in 2008 and 2011. GIS, remote sensing techniques and various satellite images were used to determine distributions, surface areas, zonal centroids, and displacements of the habitats in 2000, 2008 and 2011. The total number of bird species with and without breeding evidence in 2008 and 2011 were compared with the Chi-Square test. Habitats in each UTM grid in 2008 and 2011 were compared with McNemar’s test. The impact of water level on habitats, number of breeding birds, and their breeding parameters were investigated using Spearman’s correlation analyses. The major habitats were open waters, reed beds, scrubs and woodlands, wet grasslands, and mudflats. Significant increases were observed in open waters, reed beds, and wet grasslands, but no significant change was observed for scrubs and woodlands. Out of 70 UTM grids, 69 and 48 grids corresponding to 95 and 75 observation points were surveyed in 2008 and 2011, and 34 different waterbirds were identified. The total number of breeding waterbirds significantly increased in 2011. Open waters were positively correlated with reed beds and negatively correlated with mudflats. Among 34 waterbird species, changes in the breeding parameters of 22 species were significantly correlated with the changes occurring in the major habitats. Our study demonstrates that changes in water level significantly affected the existence of key habitats and theirs distributions, resulting in significant changes in the number of breeding waterbirds and their breeding activities.
GIANT SEQUOIA (SEQUOIADENDRON GIGANTEUM [TAXODIACEAE]) SEEDLING SURVIVAL AND GROWTH IN THE FIRST FOUR DECADES FOLLOWING MANAGED FIRES

ABSTRACT Giant sequoia (Sequoiadendron giganteum) seedling survival was nearly seven (6.78) times greater in heavily charred soils than in non-burned soils 34 and 35 yr after the first experimental burns in Kings Canyon National Park, California, and the first such management burns in any western national park. Tree height, especially trees growing in intensely burned areas, was found to be highly correlated with sunlight and less so with moisture. Moisture and light were important to establishment of giant sequoias but continued growth of these trees in the first four decades of life appears to be more dependent on high levels of sunlight. Surveyed vegetation and downed wood indicated that 35 yr after management burns stand structure has developed to the point where the management areas are susceptible to destructive crown fires.
Structural determinants of spermidine-DNA interactions.

Twelve different analogs of spermidine (SPD) and SPD itself were compared for their ability to modulate two conformational transitions of DNA; the B-to-Z conformational transition of poly(dG-me5dC) and the thermal melting transition of calf thymus DNA. The analogs consisted of five N-ethyl-SPD derivatives [N1-ethyl-SPD, N4-ethyl-SPD, N8-ethyl-SPD, N1,N8-bis(ethyl)SPD and N1,N4,N8-tri(ethyl)SPD], which differed in the number and/or position of the ethyl substitution (the alkyl series); three N-acetyl-SPD derivatives (N1-acetyl-SPD, N4-acetyl-SPD, and N8-acetyl-SPD), which were comparable to the N-ethyl-SPD derivatives but not protonated at the substituted amine (the acyl series); three aliphatic analogs [nor-SPD, homo-SPD, and N1,N9-bis(ethyl)homo-SPD], which differed in the interamine carbon chain length (homolog series), and 1,8-diaminooctane, which was comparable in overall chain length to SPD but lacked a central nitrogen. By comparing the relative abilities of the various analogs and SPD to modulate DNA structural transitions, it is possible to gain insight into the relative significance of the number and location of protonated amines (acyl series), the number and location of steric groups (alkyl series), aliphatic chain length (homolog series), and the central amine (1,8-diaminooctane) as determinants of SPD–DNA interactions. The B-to-Z conformational transition was facilitated to a midpoint by 2.4 μM SPD under conditions of low (i.e., 11 mM Na+) ionic strength. The phenomenon was affected most significantly by the number of protonated amines followed in rank order by location of the protonated amines, number of steric groups (bulk), steric group location, and aliphatic chain length. Stabilization of DNA to thermal melting was also most affected by the number of protonated amines followed by aliphatic chain length, number of steric groups, and location of protonated amines. In general, substitutions at the central (N4) amine of SPD exerted a significant influence on the B-to-Z transition but not on thermal melting.
The Issuance of sTaTe and LocaL debT durIng The unITed sTaTes greaT recessIon

This research explores the borrowing behavior of state and local governments between 2008 and 2010, a period that encompasses the Great Recession. State and local governments continued to borrow markedly during this period of severe fiscal stress. Following an overview of state-local debt and subnational government borrowing, we present a statistical analysis of the demographic, economic, political, and institutional factors that influenced interstate differences in borrowing. This research suggests that both economic and political factors influenced borrowing and that the availability of Build America Bonds contributed to an increase in borrowing during this period.
Iatrogenic vertebral artery injury

Iatrogenic vertebral artery injury (VAI) results from various diagnostic and therapeutic procedures. The objective of this article is to provide an update on the mechanism of injury and management of this potentially devastating complication. A literature search was conducted using PubMed. The iatrogenic VAIs were categorized according to each diagnostic or therapeutic procedure responsible for the injury, i.e., central venous catheterization, cervical spine surgery, chiropractic manipulation, diagnostic cerebral angiography, percutaneous nerve block, and radiation therapy. The incidence, mechanisms of injury, and reparative procedures were discussed for each type of procedure. The type of VAI depends largely on the type of procedure. Laceration was the dominant type of acute injury in central venous catheterization and cervical spine surgery. Arteriovenous fistulae and pseudoaneurysms were the delayed complications. Arterial dissection was the dominant injury type in chiropractic manipulation and diagnostic cerebral angiography. Inadvertent arterial injection caused seizures or stroke in percutaneous nerve block. Radiation therapy was responsible for endothelial injury which in turn resulted in delayed stenosis and occlusion of the vertebral artery (VA). The proximal VA was the most vulnerable portion of the artery. Although iatrogenic VAIs are rare, they may actually be more prevalent than had previously been thought. Diagnosis of iatrogenic VAI may not always be easy because of its rarity and deep location, and a high level of suspicion is necessary for its early detection. A precise knowledge of the surgical anatomy of the VA is essential prior to each procedure to prevent its iatrogenic injury.
Peripheral neuropathy in two dogs: correlation between clinical, electrophysiological and pathological findings

The clinical, electrophysiological and pathological features of two dogs with peripheral neuropathies are presented. Both dogs had clinical signs of diffuse lower motor neuron disease including paresis, hypotonia, depressed segmental spinal reflexes and generalized muscle wasting. Giant motor units and abnormal spontaneous activity were recorded in distal limb muscles. The muscle pathology demonstrated chronic denervation and re-innervation, with extensive fibre type grouping in distal muscles in one case. The distal peripheral nerves showed a marked decrease in myelinated fibres; segmental demyelination and remyelination were a prominent feature of teased fibre preparations. In both dogs the recurrent laryngeal nerves were severely affected. The aetiology of these neuropathies remains obscure but their association with other systemic diseases is discussed.
Device CAD in the '90s: at the crossroads

Various issues concerning technology computer-aided design (TCAD), including fundamental research, practical issues of user friendliness, experimental verification, and framework initiatives are discussed. The focus is on device CAD, in which there is a continuing shift of emphasis from basic issues of device physics and engineering to questions of manufacturability and technology scalability. The automation of input, computational mesh, and electrical biasing information generation in TCAD systems is described. The visualization and interpretation of simulated results, the advent of new computer hardware, and the use of statistical simulations in TCAD technology are discussed. It is argued that while technology experts are willing to tolerate awkwardness in a TCAD system, new users of TCAD, such as circuit designers and manufacturing engineers, demand automation, robustness, and reliability as standard features. >