cssi/SciSciGPT-SciSciNet huggingface dataset:
A mathematical analysis of in vitro molecular selection-amplification.

Abstract We construct a mathematical model for in vitro molecular selection with amplification. Using DNA-protein binding as the illustrative example, we obtain an expression for the probability that a randomly selected molecule from the final in vitro selection products is a molecule with the highest binding affinity. Experiments of this type have been reported for several examples of DNA binding proteins. Our study requires a model of the DNA-protein binding constant between DNA molecules and the target protein. The relationship between binding constants and selection probabilities is presented under simplifying but reasonable assumptions. From our analysis, we find that for successful in vitro selection experiments there should be a certain relationship between the number of polymerase chain reaction cycles and the concentration of free protein. The results obtained should be widely applicable to a variety of selection – amplification procedures.
Adaptive vector quantization

In adaptive quantization, the parameters of a quantizer are updated during real-time operation based on observed information regarding the statistics of the signal being quantized. This paper first discusses single parameter backward adaptation for scalar and vector quantization. It is shown that the convergence theory for adaptive quantization is intimately tied to the theory of adaptive signal processing based on the stochastic gradient algorithm. The more general problem of adoptively optimizing the entire quantizer in realtime using forward-adaptive techniques is discussed next. Progressive codevector replacement and stochastic gradient based codebook adaptation are described.
On a class of adaptive suboptimal Riccati-based controllers

In this paper a nonlinear modification is applied to the feedback law resulting from the standard linear optimal control problem formulated in state-space. This modification weights the value of the state feedback matrix with a gain factor whose derivative is proportional to the difference of a weighted inner product of the state vector and the logarithm of the gain factor. The result is completely general and therefore applies to multi-input multi-output systems. An example illustrates the extent to which the convergence rate is increased using the nonlinear feedback law for large values of the state.
Role of intracardiac ultrasound in interventional electrophysiology.

Purpose of reviewInterventional procedures in the electrophysiology and catheterization laboratory are rapidly advancing. Critical to the advancement of these procedures is accurate identification of critical anatomic landmarks and catheter position. Fluoroscopy remains the mainstay for general iden
Social impacts: Internet filter effectiveness—testing over- and underinclusive blocking decisions of four popular web filters

In the wake of the Littleton, Colorado, shooting tragedy, public attention has again been focused on the problem of potentially harmful Internet content. Many parents and legislators have proposed that commercially available filtering software is the best way to keep children away from the “red light districts of cyberspace” while also protecting the First Amendment. Civil libertarians and others, however, have noted that Internet content filters do not work as advertised, failing to block much dangerous material and also unjustly blocking benign content. The aim of this article is to assess these competing claims by rigorously testing the effectiveness of four popular filtering programs: CYBERsitter, Cyber Patrol, Net Nanny, and Surf Watch. The findings of this study suggest that current support for filtering software should be reconsidered.
Direct stimulation of adcc by cloned gamma interferon is not ablated by glucocorticoids: Studies using a human monocyte-like cell line (U-937)

Abstract We have used the macrophage-like cell line U-937 to demonstrate that recombinant gamma (immune) interferon (γ-IFN) acts directly on the mononuclear phagocyte in the absence of other cell types to increase Fc receptor sites and antibody-dependent cellular cytotoxicity (ADCC). Incubation of U-937 for 18hr with 2% γ-IFN-rich supernatant, or with 10 U/ml of pure recombinant γ-IFN, resulted in a seven-fold increase in Fc receptors as measured by the binding of radiolabeled IgG or fluoresceinated IgG and cytofluorography. Simultaneous measurement of ADCC for chick erythrocytes showed a seven-fold increase. This augmentation of Fc receptors and function was not ablated by an immunosuppressive concn of the glucocorticoid dexamethasone. The potent effects of γ-IFN both on surface receptors and effector functions of macrophages suggest that it is an important mediator in the efferent limb of immunity. Moreover, our findings that physiologic levels of glucocorticoids do not block activation of the mononuclear phagocyte support our view that glucocorticoids are immunosuppressive as a result of their action on γ-IFN-producing cells. This would seem an important consideration in the development of potential strategies for obviating steroid-induced immunosuppression.
Maximum Rainfall from Tropical Cyclone Systems which Cross the Appalachians.

Abstract The results of a statistical study of maximum measured rainfall amounts of tropical cyclone systems whose paths cross the Appalachian Mountains an presented. The study includes storms from 1900 through 1969 and considers primarily the maximum recorded rainfall in mountainous terrain. The criteria are that the tropical cyclone had to pass the 1000-ft contour and that the precipitation was measured inside the outer-most 1000-ft contour. In some cases the maxima were recorded at altitudes below the 1000-ft contour; these locations were in valleys surrounded by higher elevations. Supplemental information is presented for maximum rainfall anywhere after storm landfall, although passage of the system over the Appalachian region remained a criterion. The data are modelled by the gamma distribution. Probabilities of exceeding a specified rainfall amount and rainfall amounts for specified probability levels are presented in tabular and graphical form.
Density-dependent expression of hyaluronic acid binding to vascular cells in vitro.

Abstract Alterations in glycosaminoglycans and their receptors have been associated with changes in cell proliferation during development, wound healing, regeneration, and remodeling. We have previously found a differential effect of hyaluronic acid on the attachment of vascular cells in vitro; endothelial cell (EC) attachment was improved on hyaluronic acid-coated substrates, whereas that of smooth muscle cells (SMC) was reduced ( Orlidge and D'Amore, 1986 ). To determine if hyaluronic acid binding sites are involved in these different substrate preferences, we have studied specific hyaluronic acid binding to cultured bovine aortic EC and SMC. Since very large numbers of cells are required for these binding assays (3 × 10 6 /data point), and since the level of hyaluronate binding to fixed and native SMC and EC was similar, fixed cells were used throughout this study. The effect of cell density on hyaluronic acid binding was investigated. No significant difference was observed between hyaluronic acid binding to sparse and high density SMC. On the other hand, a more than threefold elevation in specific hyaluronic acid binding was observed on low density EC when compared to binding on high density EC. Hyaluronic acid binding was found to be specific; excesses of heparan sulfate and chondroitin sulfate had no effect on the levels of specific binding. Finally, the effect of cell passage on SMC binding of hyaluronic acid was measured. Specific binding was measured from 1st to 12th passage cells and was found to increase with passage number so that by passage 12, hyaluronic acid binding was fourfold that of 1st passage cells. These data support the concept that SMC may become less differentiated upon continuous culture. Our results indicate quantitative changes in the level of hyaluronic acid binding to vascular cells as a function of their growth state. Further, these data correlate well with in vivo observations which suggest a role for hyaluronic acid in vascular development.
Hierarchical Bayesian regularization of reconstructions for diffuse optical tomography using multiple priors

Diffuse optical tomography (DOT) is a non-invasive brain imaging technique that uses low-levels of near-infrared light to measure optical absorption changes due to regional blood flow and blood oxygen saturation in the brain. By arranging light sources and detectors in a grid over the surface of the scalp, DOT studies attempt to spatially localize changes in oxy- and deoxy-hemoglobin in the brain that result from evoked brain activity during functional experiments. However, the reconstruction of accurate spatial images of hemoglobin changes from DOT data is an ill-posed linearized inverse problem, which requires model regularization to yield appropriate solutions. In this work, we describe and demonstrate the application of a parametric restricted maximum likelihood method (ReML) to incorporate multiple statistical priors into the recovery of optical images. This work is based on similar methods that have been applied to the inverse problem for magnetoencephalography (MEG). Herein, we discuss the adaptation of this model to DOT and demonstrate that this approach provides a means to objectively incorporate reconstruction constraints and demonstrate this approach through a series of simulated numerical examples.
Ultrafast Nonlinear Optical Properties of Charge-Transfer Polymers. Transient Holography and Transient Absorption Studies

Charge-transfer polymers are a new class of nonlinear optical materials which can be used for generating femtosecond holographic gratings. Using semiconducting polymers sensitized with varying concentrations of C60, holographic gratings were recorded by individual ultrafast laser pulses; the diffraction efficiency and time decay of the gratings were measured using nondegenerate four-wave mixing. Using a figure of merit for dynamic data processing, the temporal diffraction efficiency, this new class of materials exhibits between two and 12 orders of magnitude higher response than previous reports. The charge-transfer range at polymer/C60 interfaces was further studied using transient absorption spectroscopy. The fact that charge transfer occurs in the picosecond-time scale in bilayer structures (thickness 200 A) implies that diffusion of localized excitations to the interface is not the dominant mechanism; the charge-transfer range is a significant fraction of the film thickness. From analysis of the excited state decay curves, we estimate the charge-transfer range to be 80 A and interpret that range as resulting from quantum delocalization of the photoexcitations.
Low temperature behavior of biquadratic exchange model

Abstract Recently, models of 4-spin exchange have been invoked to explain the observed first-order transitions in certain magnets. The 4-spin exchange interaction can be realized in spin-phonon coupling, also in proton diffusion in transition metals. We consider a biquadratic exchange model under a constant-coupling approximation in the low temperature region. When the biquadratic coupling Q is smaller than Qc determined by the bilinear constant J, the system undergoes a second-order transition, independent of Q otherwise. When Q is greater than Qc, one encounters the onset of first order transitions. The Q-dependent transition temperatures, which map the boundaries of first and second order transitions, are described via the free energy.
The Too Few Toes principle: A formula for limb-sparing low-level amputation planning

Abstract Both single and multiple toe amputations biomechanically alter foot function to varying degrees. In patients with diabetic neuropathy, these changes often lead to increases in deformity, plantar pressure and risk for ulceration, infection and reamputation. While a philosophy that strives to maximize limb length and function by performing the fewest and most distal amputations possible is likely a good one, we believe that a basic “formula” might help serve as a guide for surgeons to balance limb function with tissue preservation. Digital amputations that exceed a “hallux plus one lesser toe” or “lesser toe plus two” digital/ray amputations in our experience often surpass a threshold of mechanical function. For any clinical scenario in which amputation would extend beyond this threshold, a transmetatarsal amputation (TMA) or pan metatarsal head resection (PMHR) should strongly be considered to avoid costly foot complications and the need for excessive revisional surgery. Such an approach still maintains an underlying philosophy of functional limb preservation. We are unaware of any other attempt to standardize the advancement of surgical intervention from multiple toe resections to a full metatarsal level or higher resection. Therefore, we present this simple formula for surgical planning in the hopes of providing the most durable and efficient care of the high-risk diabetic foot when multiple toe amputations are needed.
SEASONAL VARIABILITY AND SIMULATION OF GROUNDWATER FLOW IN A PRAIRIE WETLAND

Wetlands in regional discharge areas of the Red River Valley of eastern North Dakota provide runoff, flood protection and wildlife habitat. Two years of groundwater and soil water monitoring were used to characterize the hydrology of a 500 ha wetland 24 km north-west of Grand Forks. The objective was to describe, monitor and model important water budget processes. From November through March 1990 and 1991, the water-table dropped as water flowed towards frost in the vadose zone. Where saturated soils occurred near the surface, the water-table rose quickly in the spring. A later, larger rise occurred where the water-table and capillary fringe were deeper. During the summer, precipitation was rapidly depleted by evapotranspiration (ET). The low hydraulic conductivity of the clayey lacustrine sediments (0.1-2 m/yr) combined with a small horizontal hydraulic gradient results in minimal lateral and maximum vertical flow. The US Geological Survey MODFLOW code was used to simulate vertical saturated flow. By including actual ET (estimated from potential evaporation) and using the recharge option to represent vadose flow, the model provided good correspondence between observed and simulated hydrographs. These results suggest that a shallow vertical flow of ground and soil water dominates the hydrological budget. Simulation of unusually dry conditions, such as those experienced during the 1930s, indicates that water levels in the wetland would reach a steady-state about 0.3 m lower than normal within two to three years. Less winter vadose storage would decrease the water-level rise in spring and early summer, but would have a minimal impact on the overall yearly water budget.
Prostaglandin inhibition of acid is cAMP dependent.

Abstract Prostaglandin E (PGE) potently inhibits acid secretion stimulated by histamine, but not by acetylcholine or gastrin, and is accompanied by decreased intracellular cAMP. Adenylate cyclase receptor systems are composed of three complex proteins: cell receptor, nucleotide binding protein, and the catalytic subunit. The exact mechanism of PGE interaction with this complex remains unclear and elucidation of this site of action is the purpose of this study. We utilized molecular probes directed at the various components of adenylate cyclase. Cholera toxin alters the stimulatory subunit of the nucleotide binding proteins ( N s ), rendering it resistant to normal deactivation, whereas N -ethylmaleimide (NEM) blocks the inhibitory subunit ( N i ). Forskolin acts as a direct activator of the catalytic subunit of adenylate cyclase and 8-bromo-cAMP acts as a cyclic AMP mimetic. We measured in vitro acid secretion in isolated parietal cells by the assessment of [ 14 C]aminopyrine (AP) accumulation. The PGE 1 analog (miso) and the PGE 2 analog (DMPG) were incubated in graded doses (10 −11 to 10 −6 M ) with histamine (10 −6 M ). Miso (10 −7 M ) reduced AP accumulation to 21 ± 8% of histamine alone (100%) and DMPG (10 −6 M ) reduced AP to 61 ± 9% ( P −6 M ) and forskolin (10 −6 M ) was not significantly affected by either PGE analog ( P > 0.05) suggesting that the site of PGE interaction is proximal to the activation of the catalytic subunit. Cholera toxin (2.0 μg/ml)- and histamine (10 −6 M )-induced AP accumulation was not affected by either PGE analog ( P > 0.05), suggesting the requirement of an intact N s for PGE inhibition. Inactivation of N i by NEM (1 m M ) in parietal cells stimulated by histamine (10 −6 M ) resulted in a diminished inhibition of AP accumulation induced by miso and DMPG (78 ± 11 and 58 ± 13%) ( P
Cross-linking between the regulatory regions of troponin-I and troponin-C abolishes the inhibitory function of troponin.

We reported previously that both residues 48 and 82 on opposite sides of troponin-C's (TnC's) N-terminal regulatory hydrophobic cleft photo-cross-linked to Met 121 of troponin-I (TnI) [Luo, Y., Leszyk, J., Qian, Y., Gergely, J., and Tao, T. (1999) Biochemistry 38, 6678-6688]. Here we report that the Ca 2 + -absent inhibitory activity of troponin (Tn) was progressively lost as the extent of photo-cross-linking increased. To extend these studies, we constructed a mutant TnI with a single cysteine at residue 121 (TnI121). In Tn complexes containing TnI121 and mutant TnCs with a single cysteine at positions 12, 48, 82, 98, or 125 (TnCl2, TnC48 etc.), ToI121 formed disulfide cross-links primarily with TnC48 and TnC82 when Ca 2 + was present, and with only TnC48 when Ca 2 + was absent. These results indicate that TnI Met 121 is situated within the N-domain hydrophobic cleft of TnC in the presence of Ca 2 + , and that it moves out of the cleft upon Ca 2 + removal but remains within the vicinity of TnC. Activity assays revealed that the Met121 to Cys mutation in TnI121 reduced the Ca 2 + -present activation of Tn, indicating that Met121 is important in hydrophobic interactions between this TnI region and TnC's N-domain cleft. The formation of a disulfide cross-link between TnI121 and TnC48 or TnC82 abolished the Ca 2 + -absent inhibitory activity of Tn, indicating that the movement of the Met 121 region of TnI out of TnC's N-domain cleft is essential for the occurrence of further events in the inhibitory process of skeletal muscle contraction. On the basis of these and other results, a simple mechanism for Ca 2 + regulation of skeletal muscle contraction is presented and discussed.
LTP and activity-dependent synaptogenesis: the more alike they are, the more different they become

Recent data suggest that long-term potentiation and activity-dependent synaptogenesis share the same mechanism at the initiation stage during which NMDA receptor activity is necessary to increase the postsynaptic response via AMPA receptor currents. However, several fundamental differences between the environments of young and mature synapses and the neurons that support them suggest that the same cellular mechanism is facilitated by very different parameters in the young versus the mature brain.
Preparing To Negotiate With Payers

Periodically, a practice needs to evaluate contracts with payers and renegotiate the contracts that are performing poorly. Using a relative value unit (RVU) cost analysis, one can determine what the costs are per unit of service. Before you can attempt to negotiate, you must know your practice expenses, demographics, and clinical outcomes. It is important to consider the following about your practice: specialty services or procedures, location of the practice, accessibility, convenience of parking, and patient satisfaction data. Will the loss of your group's participation create a marketing problem for the plan or payer? What percent of your income is from this payer? Can you walk away from this contract? Using RVU cost analysis, you are able to review procedure expenses and profitability, internal and external fee schedules based on practice expenses, and a contract negotiation starting point based on RVU cost and use.
An investigation of the sensitivity of the clear‐sky outgoing longwave radiation to atmospheric temperature and water vapor

[1] The rate at which the outgoing longwave radiation (OLR) responds to perturbations in temperature and moisture plays a fundamental role in determining climate sensitivity. This study examines the clear-sky OLR sensitivities to temperature and water vapor, as quantified by its partial derivatives (radiative Jacobians). The Jacobians, as computed by the Geophysical Fluid Dynamics Laboratory (GFDL)'s line-by-line (LBL) radiative transfer model are used to verify the results from the parameterized GFDL GCM (general circulation model) radiation code. The results show that the (1) Jacobians of OLR due to incremental changes in temperature and water vapor are insensitive to different formulations of water vapor continuum absorption and (2) Jacobians of OLR are properly captured by the GCM longwave band approximation. Simulations with the GCM demonstrate that uncertainties in the formulation of continuum absorption have little impact on the climate model simulation of clear-sky OLR changes in response to prescribed sea surface temperature (SST) perturbation. The numerically computed Jacobians of OLR are used to reconstruct the tropical annual mean OLR from the variations of temperature and water vapor over the period 1980–1999. The reconstructed OLR anomaly time series agrees well with that computed explicitly by the GCM. On the basis of this result, it becomes possible to separate out the temperature and water vapor contributions to the OLR variation. The results show that the temperature contribution dominates the water vapor contribution in the lower and middle troposphere, while in the upper troposphere the two contributions largely offset each other.
The American Nursing Shortage: Implications for Community Colleges

This article examines national employment and program trends in the nursing profession, the nursing shortage in Iowa, and state policy and community college responses in Iowa. During the seven-year period 2001–2008, two Iowa governors convened special task forces to study the nursing shortage and to make recommendations. The policy responses dealt principally with the recruitment of nursing students, scholarships and forgivable loans for students, improvement of the public's image of the nursing profession, and improvement in the work place for nurses. Meanwhile, the community colleges increased their program capacity by adding sections, and implementing part –time, evening, and weekend programs. Nursing program enrollments increased 63% from fiscal year 2001–2006. During this same time period, nursing program graduation rates decreased almost eight percent; waiting lists of qualified applicants to the program continued to be long. The author poses questions regarding the success of proprietary institutio...
A sample preparation method for four point bend adhesion studies

A method to prepare samples for four point bend testing is reported in this paper. The traditional method of sample preparation involves time-consuming steps of sawing with a diamond saw followed by polishing with fine grit to remove the roughness of the sidewall. The new method uses cleaving along the 〈100〉 crystallographic direction, which renders smooth surfaces and eliminates the polishing steps. Load–displacement curves comparing polished versus cleaved samples show that the new technique provides improved results. Elimination of fracture-inducing defects is the primary benefit of this method, which also leads to data with tighter distributions.
Failure of complete in vivo inhibition of cathepsin D to mitigate the pulmonary arthus reaction.

SummaryThis is the first demonstration that pepstatin levels following i.p. injection may be reached which are totally inhibitory to cathepsin D contained in the lung. Thus an animal model has been created, which is devoid of cathepsin D as demonstrated by measurement of an extract of the lung. When this model was challenged with the pulmonary Arthus reaction no inhibition of the Arthus reaction was observed. We conclude that cathepsin D is not the primary direct mediator of the pulmonary Arthus reaction.The authors are grateful for the helpful assistance of Drs. P. A. Ward and H. Scherzer of the University of Connecticut School of Medicine and Drs. M. Osman and D. Ischii of Columbia College of Physicians and Surgeons, New York, New York. This project was supported by USPHS Grant HL15832, N.Y. Lung Association Fellowship 538, The Stony Wold-Herbert Fund, and the Council for Tobacco Research.
Theory of polytypism and the FCC/HCP transition

Abstract A review is presented of the physics that determines phase stability and structural transitions in close-packed metals. Microscopic considerations show that both long range (Friedel) electronic and short-range elastic contribution to the total energy break the degeneracy among different stacking polytypes. These factors largely determine the structural phase diagram as a function of band filling for both simple and transition metals. A phenomenological model based on the observation suggests that the HCP - > FCC transition should be regarded as continuous rather first order. The effect of external pressure, shear stress and temperature are explored in this context and contrasted with more traditional views. Examples are drawn from the elemental metals, alloys and artificial metallic superlattices.
Surface Modification of Cured Cement Pastes by Silane Coupling Agents

X-ray photoelectron spectroscopy (XPS) and static contact angle measurements were used to study the interaction between silane coupling agents and cured cement paste. Three different silane coupling agents were investigated: aminopropyltriethoxy silane (APTES), 3-glycidyloxypropyltrimethoxy silane (GPTMS), and methoxy-terminated polydimethxyl siloxane (PDMS). These silanes have different end groups, so the change in surface energy after undergoing a successful reaction between the silane and hydroxyls on the surface of the cement paste was demonstrated by a change in contact angle. Relative to untreated samples, APTES samples decreased the contact angle, PDMS samples increased the contact angle, and GPTMS did not show a significant change in contact angle. Samples with a water-to-cement ratio (w/c) of 0.5 showed a larger change in contact angle than 0.4 w/c ratio samples, because of a greater number of hydroxyl groups at the surface. Deconvolution of the O 1s and Si 2p XPS peaks were performed to determin...
Resource Management In Amazonia: Indigenous and Folk Strategies

Resource Management In Amazonia: Indigenous and Folk Strategies. Darrell A. Posey and William Balee. editors. Advances in Economic Botany, Volume 7. New York: The New York Botanical Garden, 1989. vll. 304 pp. $59.00 (paper). ISBN 0-89327-340-6.
A STUDY OF MUSCULAR EFFICIENCY IN RATS INJECTED WITH ANTERIOR PITUITARY GROWTH FACTOR1

IN A PREVIOUS publication, Bartoli, Reed and Struck (1) reported that the IN anteriorpituitary growth factor administered to white rats increased the total nitrogen content of muscle calculated on a dry weight basis and also increased the water content. It seemed of interest to determine whether these changes represent any physiological advantage. It is the purpose of this paper to report the results of an investigation of this point. The literature has been extensively reviewed by Lee (2). A colony of white rats was divided into two groups. Group I served as controls. Group 2 after 28 days of age received daily intraperitoneal injections of the growth factor. Up to 35 days the dose was 2 units per rat, up to 77 days, 3 units, and thereafter 6 units. The diet was the same as described i n the earlier paper referred to. The weight curves are shown in figure I.
The influence of inhaled nitric oxide on cerebral blood flow and metabolism in a child with traumatic brain injury.

IMPLICATIONS The effects of inhaled nitric oxide (INO) on cerebrovascular hemodynamics are not well established. We report no adverse cerebral effects with INO therapy in a child with traumatic brain injury.
A new formalism for molecular dynamics in internal coordinates

Abstract Internal coordinate molecular dynamics (ICMD) has been used in the past in simulations for large molecules as an alternative way of increasing step size with a reduced operational dimension that is not achievable by MD in Cartesian coordinates. A new ICMD formalism for flexible molecular systems is presented, which is based on the spectroscopic B -matrix rather than the A -matrix of previous methods. The proposed formalism does not require an inversion of a large matrix as in the recursive formulations based on robot dynamics, and takes advantage of the sparsity of the B -matrix, ensuring computational efficiency for flexible molecules. Each molecule’s external rotations about an arbitrary atom center, which may differ from its center of mass, are parameterized by the SU (2) Euler representation, giving singularity free parameterization. Although the formalism is based on the use of nonredundant generalized (internal and external) coordinates, an MD simulation in linearly dependent coordinates can be done by finding a transformation to a new set of independent coordinates. Based on the clear separability in the generalized coordinates between fast varying degrees of freedom and slowly varying ones, a multiple time step algorithm is introduced that avoids the previous nontrivial interaction distance classification. Also presented is a recursive method for computing nonzero A -matrix elements that is much easier to apply to a general molecular structure than the previous method.
Development of a high sensitivity liquid scintillation-NaI(Tl) coincidence detector for X-γ emitters in lunar rocks

Abstract A new type of high sensitivity counter employing a liquid scintillation cell as a coincidence gate for a 3″ NaI(Tl) well crystal has been developed for the detection of small amounts of X-γ emitting nuclides. This counter has approximately 10 times the efficiency of a comparable detector employing a conventional gas proportional counter as the coincidence gate. The background of the existing system under the full width at half maximum of the 54 Mn photopeak is 0.02 cpm. Measurements to the 15% precision level of as little as 0.25 dpm of 54 Mn in lunar rock samples are reported. The applicability of the counter to X-γ emitters other than 54 Mn is discussed.
Juvenile Granulosa Cell Tumor

A 2-year-old girl presented with isosexual precocity, and a juvenile granulosa cell tumor of the left ovary was removed. The tumor was unusual in that striated muscle differentiation of the tumor cells was demonstrated. This suggests that the mesenchymal cells retain the potential for divergent differentiation.
Maternal obesity, uterine activity, and the risk of spontaneous preterm birth.

OBJECTIVE To assess the associations among maternal obesity, uterine contraction frequency, and spontaneous preterm birth in women at risk for spontaneous preterm birth. METHODS In a secondary analysis, we analyzed data from 253 women at risk for spontaneous preterm birth (prior spontaneous preterm birth, vaginal bleeding) enrolled in a multicenter observational study of home uterine activity monitoring at 11 centers. All women wore a uterine activity monitor twice daily from 22 weeks through 34 weeks of gestation. Mean and maximal contractions/hour at 22-24, 25-26, 27-28, 29-30, 31-32 weeks, and at or after 33 weeks of gestation were compared between overweight/obese women (a body mass index [BMI] at 22-24 weeks greater than 25 kg/m) and normal/underweight women (a BMI of 25 kg/m or less) at each gestational age interval. Multivariable analysis evaluated the influences of BMI, contractions, fetal fibronectin, and transvaginal cervical length on spontaneous preterm birth before 35 weeks. RESULTS Obese/overweight women (n=156) were significantly less likely to experience spontaneous preterm birth before 35 weeks (8.3% compared with 21.7%, P<.01). For each gestational age interval before 32 weeks, obese/overweight women had fewer mean contractions/hour (P<.01 for each) and maximal contractions/hour (P<.01 for each) than normal/underweight women, although their mean cervical lengths (34.3 mm compared with 33.1 mm, P=.25), and fetal fibronectin levels (7.1% compared with 7.2% 50 ng/mL or more, P=.97) were similar at study enrollment. Obese/overweight status was associated with a lower risk of spontaneous preterm birth before 35 weeks after controlling for contraction frequency and other factors evaluated at 22-24 weeks, but not at later periods. CONCLUSION Obese/overweight women at risk for spontaneous preterm birth exhibit less uterine activity and less frequent spontaneous preterm birth before 35 weeks of gestation than normal/underweight women. LEVEL OF EVIDENCE II.
Mean motions and longitudes in indian astronomy

The astronomy we find in texts from ancient India is similar to that we know from ancient Greco-Roman sources, so much so that the prevailing view is that astronomy in India was in large part adapted from Greco-Roman sources transmitted to India. However, there are sometimes differences in the details of how fundamental ideas are implemented. One such area is the technique for dealing with mean motions and longitudes. The Greek methods explained by Ptolemy are essentially identical to what we use today: one specifies a mean longitude 0 λ for some specific day and time – the epoch
Correlating temporal communication patterns of the Eclipse open source community with performance and creativity

This paper studies the temporal communication patterns of online communities of developers and users of the open source Eclipse Java development environment. It measures the productivity of each community and seeks to identify correlations that exist between group communication characteristics and productivity attributes. The study uses the TeCFlow (Temporal Communication Flow) visualizer to create movie maps of the knowledge flow by analyzing the publicly accessible Eclipse developer mailing lists as an approximation of the social networks of developers and users. Thirty-three different Eclipse communities discussing development and use of components of Eclipse such as the Java Development Tools, the different platform components, the C/C++ Development Tools and the AspectJ extension have been analyzed over a period of six months. The temporal evolution of social network variables such as betweenness centrality, density, contribution index, and degree have been computed and plotted. Productivity of each development group is measured in terms of two indices, namely performance and creativity. Performance of a group is defined as the ratio of new bugs submitted compared with bugs fixed within the same period of time. Creativity is calculated as a function of new features proposed and implemented. Preliminary results indicate that there is a correlation between attributes of social networks such as density and betweenness centrality and group productivity measures in an open source development community. We also find a positive correlation between changes over time in betweenness centrality and creativity, and a negative correlation between changes in betweenness centrality and performance.
Planetary-Scale Forcing of the January 1977 Weather

The type of weather anomalies that occurred in the United States during January 1977 are typical of a planetary-scale wave phenomenon called stratospheric sudden warming (SSW). Specific changes in weather parameters nearly always accompany SSW. Blocking ridges (intensified high-pressure cells) develop over the oceans, the North Pole warms, mid-latitudes cool, and continental temperatures plunge. These characteristics usually persist for at least a month. When the SSW is strong, as in January 1958, 1963, and 1977, the accompanying weather anomalies can be unusually severe.
Preliminary geochemical assessment of limestone resources and stone use at Maya sites in the Three Rivers Region, Belize

The carbonate bedrock of northwestern Belize is poorly understood from the standpoint of both geochemistry and the use of stone in prehispanic Maya sites for buildings and monuments. The friable nature of the rock in this topographically rugged area makes it especially difficult to distinguish monuments from bedrock spall, as little carving, if any, survives, and identification rests on location and positioning. The research presented here analyzed 63 limestone samples collected from two sites in the Three Rivers Region of Belize. ICP-MS and ICP-AES were used to characterize the major, minor, and trace element chemistry of the limestone bedrock of the region and determine the amount of geochemical variability. Another important objective was attempting to trace the movement of monument stone and determining whether it was imported from outside of the sites. Bedrock, quarries, and possible monuments were all sampled for these purposes. Bedrock proved to be similar across wide areas. However, at Chawak But'o'ob, along the flank of the Rio Bravo, changes downslope in Mg concentration suggest a leaching of the bedrock by meteoric waters based on differences in porosity. At Maax Na, a hilltop site, in contrast, such leaching is not as apparent. Many monuments at both sites were found to be composed of stone similar in chemistry to the local bedrock, including several of the identifiable stelae. However, our analyses also revealed that a few monuments at Maax Na were made of material with a different chemical composition, apparently from stone imported to the site. These results suggest that the Maya deliberately selected certain types of limestone for certain purposes, and may even have traded in non-local rock. Overall, the methods used in this pilot study indicate there is real potential in more intensive, regional assessments of the materials used at archaeological sites, even in areas where the local stone does not have a distinctive geochemical signature.
Independent evaluation of the effects of glibenclamide on reducing progressive hemorrhagic necrosis after cervical spinal cord injury

These experiments were completed as part of an NIH-NINDS contract entitled "Facilities of Research Excellence - Spinal Cord Injury (FORE-SCI) - Replication". Our goal was to replicate pre-clinical data from Simard et al. (2007) showing that glibenclamide, an FDA approved anti-diabetic drug that targets sulfonylurea receptor 1 (SUR1)-regulated Ca(2+) activated, [ATP](i)-sensitive nonspecific cation channels, attenuates secondary intraspinal hemorrhage and secondary neurodegeneration caused by hemicontusion injury in rat cervical spinal cord. In an initial replication attempt, the Infinite Horizons impactor was used to deliver a standard unilateral contusion injury near the spinal cord midline. Glibenclamide was administered continuously via osmotic pump beginning immediately post-SCI. The ability of glibenclamide to limit intraspinal hemorrhage was analyzed at 6, 12 and 24 h post-injury using a colorimetric assay. Acute recovery (24 h) of forelimb function was also assessed. Analysis of data from these initial studies revealed no difference between glibenclamide and vehicle-treated SCI rats. Later, it was determined that differences in primary trauma affect the efficacy of glibenclamide. Indeed, the magnitude and distribution of primary intraspinal hemorrhage was greater when the impact was directed to the dorsomedial region of the cervical hemicord (as in our initial replication experiment), as compared to the dorsolateral spinal cord (as in the Simard et al. experiment). In three subsequent experiments, injury was directed to the dorsolateral spinal cord. In each case, glibenclamide reduced post-traumatic hemorrhage 24-48 h post-injury. In the third experiment, we also assessed function and found that acute reduction of hemorrhage led to improved functional recovery. Thus, independent replication of the Simard et al. data was achieved. These data illustrate that the injury model and type of trauma can determine the efficacy of pre-clinical pharmacological treatments after SCI.
Sarcomeric oscillations in frog skeletal muscle fibers

Brief asynchronous, small-amplitude, cyclic, longitudinal displacements of the striations of frog skeletal muscle fibers were observed with ordinary light microscopy after application of caffeine and certain quaternary ammonium compounds. With time these oscillations became synchronized and evolved into peristaltic-like movements. The oscillations were influenced by sarcomere length, temperature, external concentration of calcium ions, membrane potential, and disruption of the transverse tubules.
TREND: an important step, but not enough.

Des Jarlais et al. provide an important service by publishing the TREND statement, which lists data reporting recommendations for behavioral and public health interventions.1 We commend the authors for addressing such issues as information on the target population, recruitment criteria, methods of imputing missing data, comparison of the study population to the target population of interest, and testing of causal pathways. These criteria, although important, are not enough to realize the TREND group’s purpose of creating generalizable knowledge. The goal of public health interventions is to make a difference on a population level (or in a representative sample or segment of a specified population). Reporting the TREND criteria will improve the quality of the literature, but additional criteria related to external validity are also needed. We offer suggestions based on recent literature reviews of behavior change studies.2–6 Few studies reported on the representativeness or impact of setting-level factors and intervention staff, which are critical to an understanding of moderating variables and external validity. To address this problem, we recommend the addition of the following criteria to TREND: Report the percentage of eligible settings (e.g., schools, worksites, community organizations) that participated and compare characteristics of those participating with characteristics of those declining (or with characteristics of a specified target population of settings). Report the percentage of intervention staff members in these settings who participate in delivering the intervention; compare characteristics of those participating with characteristics of those declining (or with characteristics of a specified target population of clinicians); and compare differences in intervention delivery and outcomes among those who participate. Report costs of the intervention, such as capital outlay and staff hours, and, where feasible, report on more sophisticated economic outcomes. Report long-term results and the extent to which settings sustain or modify the program after the formal study has been completed. The TREND group stated that nonrandomized designs are needed to strengthen the evidence-based public health practice literature. The advantages of nonrandomized designs over randomized controlled trials include being less expensive to conduct and not requiring agreement to randomization for participation. Nonrandomized designs provide greater opportunity than randomized controlled trials to obtain cost estimates in limited-resource environments and to evaluate implementation conducted by typical staff members. The TREND criteria can benefit the public health community as the CONSORT7 criteria have benefited medicine. In response to the TREND group’s call for feedback, we offer these suggestions to address issues critically important for the translation of research to practice.
The effects of dexamethasone immunosuppression on turkey osteomyelitis complex in an experimental Escherichia coli respiratory infection

Abstract Six hundred male turkeys were maintained in floor pens for 5 wk at which time half of the birds were given three intramuscular injections of 2 mg/kg BW of dexamethasone (DEX) on alternating days. On the day of the third DEX injection, the left thoracic air sac of each bird was injected with sterile tryptose phosphate broth (TPB) or with TPB containing approximately 1 x 10(2), 1 x 10(3), 1 x 10(4), or 1 x 10(5) cfu of Escherichia coli. All mortalities and birds necropsied at 14 and 15 d postchallenge were scored for air sacculitis/pericarditis (AS) and turkey osteomyelitis complex (TOC). Cumulative mortality and AS score were both increased by either DEX treatment or E. coli. Although TOC incidence was significantly increased by the lowest titer of E. coli inoculation, increasing the number of bacteria inoculated did not increase TOC incidence due to increased mortality before TOC lesions developed. The DEX treatment by itself increased TOC incidence and there was a synergistic interaction between DEX treatment and E. coli on TOC incidence. Both DEX treatment and E. coli significantly decreased BW. Relative weights of liver, heart, and spleen were significantly increased by both E. coli and DEX, whereas both treatments significantly decreased relative weight of the bursa of Fabricius. The number of positive bacterial isolations from tissue and the heterophil to lymphocyte ratio were increased by both DEX treatment and E. coli challenge. These results suggest that stress-induced immunosuppression may be involved in the etiology of TOC, and that bacterial respiratory infection can lead to the development of TOC lesions.
Mars exploration rover engineering cameras

The NASA Mars Exploration Rover mission will launch two scientific spacecraft to Mars in 2003. The primary goal of the mission is to obtain knowledge of ancient water and climate on the red planet. Each spacecraft will carry one rover with a mass of approximately 150 kg and a design lifetime of about 90 days to the surface of Mars. The rovers are intended to travel up to 100 meters per day. The scientific payloads of the rovers will include a stereo pair of Panoramic cameras and a Microscopic Imager. The Panoramic cameras also support the engineering functions of high gain antenna pointing and navigation by solar imaging. The rovers have six additional cameras that will be used, exclusively, for engineering. All nine cameras share a common design, except for their optics. The focal plane of each camera is a 1024 X 1024-pixel frame transfer CCD. A stereo pair of Navigation cameras is mounted on a gimbal with the Panoramic camera pair. The Navigation camera pair is used for traverse planning and general imaging. Finally, one stereo pair of wide-angle Hazard Avoidance cameras will be mounted on the front (and one pair on the back) of each rover to autonomously generate range maps of the surrounding area for obstacle detection and avoidance.
Deletional analysis of the promoter region of the human transferrin receptor gene

Fragments of human genomic DNA corresponding to the promoter region of the gene for the transferrin receptor have been cloned upstream of the bacterial gene for chloramphenicol acetyltransferase and these constructs used to assess promoter activity following transfection into a human rhabdomyosarcoma cell line. Progressive 5' deletions as well as internal linker-substitution constructs support a critical role in gene expression of a sequence element approximately 70 bp upstream of the mRNA start site. In this region, the receptor gene was found to contain 11bp that are identical to a segment of the enhancers of polyoma virus and adenovirus. A fragment encompassing this element was shown to increase gene expression when the fragment was placed in either orientation upstream of the remainder of the transferrin receptor promoter but the same fragment did not activate an enhancer-less SV40 promoter. Removal from within the receptor promoter of three potential binding sites for the transcription factor Sp1 did not decrease the promoter's activity.
Chemotherapy treatment patterns, costs, and outcomes of patients with gastric cancer in the United States: a retrospective analysis of electronic medical record (EMR) and administrative claims data

Background The aim of this study was to conduct a retrospective database analysis to describe the chemotherapy treatment patterns and outcomes of patients with gastric cancer.