cssi/SciSciGPT-SciSciNet huggingface dataset:
SU‐FF‐T‐179: Accuracy of CT Numbers and Its Effect On Dose Calculations

Purpose: The CT‐to‐density conversion table can vary for various CTscanners or when using different scanning parameters (such as KVp, field‐of‐view etc.). These CT number variations could be up to −/+100 for the same material. However, the dosimetric impact of these CT number variations was not well studied in the past. This study is to report the variations of CT numbers and their clinical impact on dose calculations. Method and Materials: The CT‐to‐density conversion table was measured on six different scanners. Two special tables were created with +/− 100 CT‐number shifts from the default conversion table in our clinic. Data showed that these two tables represented two bounding situations to accommodate the variations in different CTscanners or scanning parameters. Treatment plans using lung, head and neck, prostate, and breast cases were recalculated using these new CT conversion tables for both photon and electron beams.Results: There were noticeable differences across different density ranges for different CTscanners. Using the two extreme CT‐to‐density conversion tables, it was shown that the differences in dose calculations were −1.6% to 0.3% for head & neck (6MV), −2.5% to 0.9% for lung (6MV), −4.0% to 3.0% for prostate (6MV), and −2.3% to 1.7% for prostate (18MV), respectively. It showed that the impact was more notable for treatment targets at deeper depths or at lower beam energy. For electron beams, the distal 90% fall‐off edge was changed approximately 2 mm for commonly used electron energies. Conclusion: Dose calculations seem to be not sensitive to different CT‐density conversion tables from different CTscanners or using different CT scanning parameters. Considering most scanners were calibrated to water, our results could be the worst case scenario. A single CT‐to‐density conversion table could be used for all CTscanners.
TH‐D‐351‐01: High Temporal Resolution and Streak‐Free Four‐Dimensional Cone‐Beam Computed Tomography

Purpose: Respiratory gated CBCT (e.g. 4D CBCT) with an on‐board imager has been introduced to track tumor motion for lungcancer patients. However, the image quality is comprised by aliasing artifacts and lower CNR, due to the limited number of projections. The temporal resolution of 4D CBCT is often chosen to be around 500∼1000ms to increase the sampling at each phase. In this paper, we present a method to simultaneously achieve high temporal resolution and streaking artifacts‐free images in 4D CBCT.Method and Materials: The enabling technique is an image reconstruction method called Prior Image Constrained Compressed Sensing (PICCS). By incorporating a prior image into the reconstruction, PICCS enables accurate image reconstruction from few projections. Home made physical motion phantoms were scanned on a Varian Trilogy system. Projection data were retrospectively gated based on the phase information obtained by synchronizing the ‘x‐ray on’ signal and the motion signal. Results: The gating window was chosen so that only one projection was selected in each respiratory cycle. Streak artifacts free 4D CBCTimages were achieved using PICCS from these 11–14 selected projections, while other reconstruction algorithms like FDK and conventional Compressed Sensing failed to generate meaningful images. Temporal information was well preserved in these images and the temporal resolution in these images was primarily limited by the detector read out speed which was about 100ms. Moving objects were segmented out from images at each phase and the motion trajectory was extracted. Agreement was observed between the extracted motion profile and the programmed motion profile. Conclusion: A new algorithm, PICCS, was proposed to mitigate undersampling streaking artifacts in 4D CBCT. High temporal resolution was achievable by using fewer projections. The trajectory of moving objects could be extracted from the high quality 4D CBCTimages.
The effect of insularity on the diversity of land birds in the Fiji islands: implications for refuge design.

Ecologists have argued over rules of thumb that could be used to set priorities in configuring systems of reserves for preserving biological diversity. To evaluate these simple strategies, I assembled a particularly large and comprehensive data set on the land birds of the Fiji archipelago. I analyzed the species distribution on 220 islands to compare the running total of species preserved by different sequences of adding nature reserves to a hypothetical reserve system, treating each island as if it were a potential reserve. A strategy of maximizing the number of islands contributing to any given reserve area (maximum fragmentation) is much more effective at including species than a strategy of maximizing the size of the island components of a reserve (minimum fragmentation). Nevertheless the maximum fragmentation strategy is not a very good one. It is less effective than many random strategies, especially when about 2–10% of total area is to be set aside as reserve, and when only rare species are considered. A computer program was used to determine an “optimal” strategy by maximizing the number of additional species added for each unit of area added. This strategy is always substantially more effective at encompassing species diversity than either the maximum or minimum fragmentation strategies. It is suggested that the poor performance of the minimum fragmentation strategy is due principally to the presence of many smaller-island endemics within the Fiji archipelago. More generally, it is argued that the effect of fragmentation on species diversity depends on the geographic scale and isolation of the region under consideration. In these respects the Fiji Archipelago may be a particularly good model for continental reserve systems.
Mapping the protein-DNA interface and the metal-binding site of the major human apurinic/apyrimidinic endonuclease.

Abstract Apurinic/apyrimidinic (AP) endonuclease Ape1 is a key enzyme in the mammalian base excision repair pathway that corrects AP sites in the genome. Ape1 cleaves the phosphodiester bond immediately 5′ to AP sites through a hydrolytic reaction involving a divalent metal co-factor. Here, site-directed mutagenesis, chemical footprinting techniques, and molecular dynamics simulations were employed to gain insights into how Ape1 interacts with its metal cation and AP DNA. It was found that Ape1 binds predominantly to the minor groove of AP DNA, and that residues R156 and Y128 contribute to protein-DNA complex stability. Furthermore, the Ape1-AP DNA footprint does not change along its reaction pathway upon active-site coordination of Mg2+ or in the presence of DNA polymerase beta (polβ), an interactive protein partner in AP site repair. The DNA region immediately 5′ to the abasic residue was determined to be in close proximity to the Ape1 metal-binding site. Experimental evidence is provided that amino acid residues E96, D70, and D308 of Ape1 are involved in metal coordination. Molecular dynamics simulations, starting from the active site of the Ape1 crystal structure, suggest that D70 and E96 bind directly to the metal, while D308 coordinates the cation through the first hydration shell. These studies define the Ape1-AP DNA interface, determine the effect of polβ on the Ape1-DNA interaction, and reveal new insights into the Ape1 active site and overall protein dynamics.
Treatment of Osteoporosis and Prevention of New Fractures: Role of Intravenously Administered Bisphosphonates

ABSTRACT Objective To evaluate the usefulness of intravenously administered bisphosphonates for improving absorption, tolerability, adherence, and outcomes in the treatment and prevention of osteoporosis. Methods Data published from 1996 to 2009 relevant to the treatment of osteoporosis, with emphasis on bisphosphonates, fracture risk, adherence to therapy, frequency of dosing, intravenous treatment, tolerability, cost-effectiveness, and quality of life, were reviewed. Results Although bisphosphonates are currently the standard of care for treatment of postmenopausal osteoporosis and osteoporosis in men, oral formulations are associated with poor absorption and potential irritation of the upper gastrointestinal tract. These issues necessitate complicated and restrictive dosing regimens, which in turn lead to poor compliance and persistence. Intravenous formulations such as 3 mg of ibandronate given quarterly and 5 mg of zoledronic acid administered once yearly avoid problems relating to absorption and tolerability by bypassing the gastrointestinal tract. Intravenously administered ibandronate is presumed (by virtue of similar or superior improvements in bone mineral density) to have antifracture efficacy similar to that of orally administered ibandronate given daily, which has been shown to produce significant reductions in vertebral fractures during a 3-year period in comparison with placebo. Zoledronic acid, 5 mg once yearly, has been shown to produce a significant reduction in the risk of morphometric vertebral fractures, clinical vertebral fractures, hip fractures, and nonvertebral fractures versus placebo during a 3-year interval in patients with postmenopausal osteoporosis and also to yield a significantly decreased risk for new clinical fractures versus placebo in patients with recent low-trauma hip fracture. Both agents have favorable safety and tolerability profiles. Conclusion Intravenously administered bisphosphonates have the potential to increase compliance and persistence with therapy in patients with osteoporosis and to improve patient outcomes. (Endocr Pract. 2009;15:483-493)
Majorana masses, photon gas heating and cosmological constraints on neutrinos☆

Non-vanishing Majorana masses generally lead to flavor-changing neutral currents in the neutrino sector. It is shown that when both right- and left-handed neutrinos have non-vanishing Majorana masses (MR≠0 and ML≠0), flavor-changing neutral currents could be as large as flavor-diagonal ones. However, when only right-handed neutrinos have non-vanishing Majorana masses (MR≠0 but ML=0), flavor-changing neutral currents are small. If MR⪢D (Dirac masses), they are of O((DMR)2). If MR⪅D, they are ⪅(mLmH)12, where mL and mH are masses of light and heavy neutrinos appearing in a flavor-changing process. By using these results we examine cosmological implications of non-vanishing flavor-changing neutral currents. Heavy neutrinos can decay into three light neutrinos at an appreciable rate by exchanging a Z-boson. It is demonstrated that owing to this decay mode, heavy neutrinos of mass larger than 70 keV but less than 2me give rise to no contradiction with the standard big bang cosmology in the most general case. We also show that if there exist heavy neutrinos of mass mH2me, their decay at an early era of the universe induces photon gas heating, which alters Cowsik and McClelland's constraint on light neutrino masses to Σ mL < k · 100 eV with the sum running over all Majorana eigenstates. Here the constant k, representing the heating effect of the photon gas, is restricted by the deuterium abundance of the present universe. For instance, Σ mL < 240 eV for mH ∼ 25 MeV and the present baryon density = 3.4 × 10−31 g · cm−3.
Another random samples clarification.

In reference to the Random Samples item “Dark memory” (28 March, p. 1979), about a lawsuit filed against Elizabeth Loftus for her alleged violation of the privacy of a young woman who was the subject of a journal article by me and a colleague, I wish to clarify that I was not “helping” the
Superior vena cava obstruction and liver transplantation in a child

We report a case of superior vena cava obstruction in a child, which was probably secondary to long-term central venous cannulation. The obstruction was asymptomatic preoperatively, but became evident during liver transplantation, and complicated the intraoperative management. There is one other case report of this occurring in an adult in similar circumstances, and we believe that ours is the first report of such a presentation in the paediatric age group.
Weakly singular integral equations for Darcy's flow in anisotropic porous media

Abstract The weakly singular, weak-form fluid pressure and fluid flux integral equations are developed for steady-state Darcy's flow in a porous media which possesses generally anisotropic permeability. A systematic technique is established first to regularize the conventional fluid pressure and fluid flux integral equations in which the former contains a singular kernel (of order 1/r2) and the latter contains a strongly singular kernel (of order 1/r3). The key step in the regularization procedure is to construct decompositions for the fluid velocity fundamental solution and the strongly singular kernel in a form well-suited for performing an integration by parts via Stokes' theorem. Weakly singular kernels appearing in these decompositions are obtained in an explicit form by the Radon transform method. The final integral equations possess following important features: (1) they contain only weakly singular kernels of order 1/r; (2) their validity requires only the continuity of pressure boundary data; and (3) they are applicable for modeling steady-state flow in porous media possessing generally anisotropic permeability and containing surfaces of discontinuity. A proper use of this set of weak-from integral equations forms a symmetric formulation for a weakly singular, symmetric Galerkin boundary element method (SGBEM). The numerical implementation is then carried out and certain examples are solved to demonstrate the accuracy of the method.
STUDIES ON CORPUS LUTEUM METABOLISM II. EFFECTS OF INTERMENSTRUAL ADMINISTRATION OF ESTROGENS1

ANUMBER of workers, including Zondek (1) and Sturgis and Albright (2), has assumed that ovulation and corpus luteum activity are disturbed, and perhaps even inhibited, by intermenstrual administration of estrogens. The clinical use of these sterols in the treatment of dysmenorrhea and cyclomastopathy frequently is based upon such a theoretical modus operandi. Studies by some members of our group (3) have indicated that the concomitant administration of estrogens and progesterone results in more effective metabolism and utilization of progesterone than the use of progesterone alone and some evidence has been encountered that in various grades of ovarian failure estrogenic therapy apparently enhanced corpus luteum metabolism. The present study deals with the effects of intermenstrually administered estrogens on the corpus luteum function of normal, healthy women. A group of 13 essentially healthy, regularly bleeding women who presented no significant endocrine disease, was selected for the study.
Non-mast cell histamine kinetics. V. 3H-histamine formation in vivo and effects of precursor pool perturbations

Following injection of a constant amount of 3H-histidine, tissue histamine specific activity was relatively independent of the specific activity of injected amino acid until the total dose of the latter approached 250 mg/kg. Similarly, after injection of a tracer dose of 3H-histidine, a small subsequent dose of non-isotopic amino acid had little effect on tissue histamine specific activity; a dose of 250 mg/kg however, lowered the specific activity of tissue amine approximately 30%. The results obtained suggest that tissue 3H-histamine is maintained for several hr by continuous synthesis from a very large free precursor pool with which a fraction of injected histidine equilibrates. After injection of isotopic amino acid, the specific activity of stomach histamine declined rapidly for 10–15 hr and then leveled off. Presumably, 3H-histamine declining at a rapid rate was largely confined to non-mast cell sites in relatively rapid turnover. It was concluded that such decline in specific activity is dependent upon the rate of turnover of histidine and is not a reflection of the rate of turnover of endogenous amine. Only after the specific activity of endogenous histidine has declined to negligible values can the slow decline of tissue histamine specific activity reflect the presumably slow turnover of histamine in mast cells.
Agroecology in the tropics: Achieving a balance between land use and preservation

Agroecology is the application of ecological concepts and principles to the design and management of sustainable agricultural systems. An agroecological approach to agriculture has special importance in the humid tropics where agricultural development and the preservation of tropical forests are most often in direct conflict. It is proposed that a more sustainable approach to development is needed, where agroecosystems depend on low external inputs, function more on the use of locally available and renewable resources, have benign impacts on the environment, and are based on the knowledge and culture of the local inhabitants. Examples of traditional agroecosystem management in Mesoamerica that can provide this basis are presented. The preservation of both biological and cultural diversity are integral to the long-term sustainable management of natural resources in the tropics.
Gravitational waves and the creation of mass

In this article we shall investigate the effect on the mass of the above gaseous region R(t) due to a gravitational wave. It will be helpful if the reader is acquainted with the contents of the foregoing article,' since the notation and some of the procedures previously used will enter into the discussion. Suppose that the region R(t) is traversed by a gravitational wave 2;(t) considered as a two-dimensional surface over which there is a discontinuity in the metric components hAB or their derivatives of a specified order. This is illustrated in Figure 1 in which the moving surface 2(t) divides the region R(t) into regions Ri(t) and R2(t). The surface 2(t) is assumed to advance into the region Ri(t) with a normal velocity G > 0 which may vary from point to point on the wave. Let us denote by S(t) the boundary of the region R(t), by S1(t) the portion of S(t) which bounds the region R1(t), and by S2(t) the portion of S(t) bounding the region R2(t); hence the boundary of Ri(t) is given by the surfaces S1(t) and 2(t) and the boundary of R2(t) by the surfaces S2(t) and 2(t), as shown in Figure 1. Finally, we have denoted by v the spatial unit vector which is normal to 2(t) and which is directed into the region Ri(t). The symbol v will also be used to denote the outward unit vector normal to the surfaces S1(t) and S2(t) comprising the boundary of R (t). Our immediate problem is now to derive the basic formula for the variation of the mass in the moving region R(t) during the time interval in which this region is traversed by the gravitational wave.
Application of Association-Marginal Models to the Study of Social Mobility

Researchers studying social mobility are often interested in examining both the association between origins and destinations and the relationship between the marginal distributions of origins and destinations. Often, this has resulted in an attempt to partition various models into components of, or derive indexes for, exchange/circulation mobility and structural mobility. As an alternative, or perhaps supplement, to such concerns, here the authors present a relatively simple but useful way to directly and simultaneously model the association between origins and destinations on one hand and, on the other hand, the relationship between origin and destination marginal distributions.
Quantitative culture of bronchoalveolar lavage fluid for the diagnosis of bacterial pneumonia

Abstract purpose: A prospective study to determine the usefulness of quantitative bacterial cultures of fluid obtained via fiberoptic bronchoscopy and bronchoalveolar lavage as an aid in the diagnosis of bacterial pneumonia. patients and methods: All patients undergoing fiberoptic bronchoscopy with bronchoalveolar lavage during a 612-month period. Presence of pneumonia was determined using clinical, radiographic, laboratory, and histologic data. Quantitative bacterial cultures of bronchoalveolar lavage fluid were determined using a 1-μL culture loop. results: Quantitative bacterial cultures of bronchoalveolar lavage (BAL) fluid were sensitive and specific predictors of bacterial pneumonia. Using 10 3 colony-forming units (cfu)/mL as the threshold value for a positive culture, we determined the sensitivity and specificity to be 90% and 97%, respectively. The data were also analyzed for the subgroups of patients who were intubated or were receiving antibiotics. The sensitivity and specificity were 78% and 96% for the group of patients receiving antibiotics and 100% and 82% for the group of patients intubated for more than 24 hours at the time of BAL. Values for the area under the receiver operating characteristic curve for the 3 groups were 0.94, 0.88, and 0.96, respectively. conclusions: Quantitative bacterial cultures of BAL fluid are sensitive and specific in the diagnosis of bacterial pneumonia. The use of antibiotics at the time of BAL reduces the sensitivity of the test, and prolonged intubation reduces the specificity of the test.
Transmission probability of a drum chopper in a thermal neutron beam

Abstract Drum choppers have been placed in the incident beams of the pulsed source instruments at IPNS (Intense Pulsed Neutron Source) in order to reduce the background resulting from delayed neutrons from the booster target. Expressions are derived for the detailed pulse shape of the transmitted neutrons and for the duration of the chopper pulse. The transmission probability depends on the neutron wavelength, the frequency of rotation of the chopper, the chopper diameter and slot width, and the incident neutron beam width. These expressions are used to compute the transmission probabilities of time-of-flight diffractometers on pulsed neutron sources which employ drum choppers. They can also be used to determine the time and wavelength dependence of the counting rates for both prompt and delayed neutrons.
QUASILINEARIZATION, SYSTEM IDENTIFICATION, AND PREDICTION

Abstract This paper is devoted to a mathematical formulation and computational solution of the problems of system identification and the determination of unmeasurable state variables on the basis of observations of a process, two topics of central importance in the design of adaptive controllers. The approach suggested—based on the theory of quasilinearization—is an outgrowth of continuing RAND research on the computational solution of multi-point boundary-value problems.
Studies on dexamethasone metabolism in man: effect of diphenylhydantoin.

Plasma kinetics and metabolism of labeled dexamethasone were evaluated in nine subjects before and after administration of diphenylhydantoin. Labeled dexamethasone was injected intravenously followed by frequent sampling of blood and urine. The labeled dexamethasone in plasma was isolated chromatographically. Total urine and fractional radioactivity after solvent extraction (chloroform and ethyl acetate), with and without glucuronide hydrolysis, were determined. Baseline plasma equilibrated t½'s and metabolic clearance rates (2 compartment model) ranged from 167 to 368 minutes and 222 to 456 liters/day, respectively. After diphenylhydantoin there were consistent decreases in t½'s and increases in metabolic clearance rate; mean changes —51% and +140% respectively. Mean recovery of urinary radioactivity at 4 and 24 hours was 16 and 64 percent of dose respectively. The largest fraction was a more polar unconjugated one, 7 and 31 percent of dose at 4 and 24 hours. Following diphenylhydantoin there was a signi...
Basement Controls on Lineament-Block Tectonics of Coastal Plain Province in Virginia: ABSTRACT

Linear features in the coastal plain of Virginia were interpreted from Landsat images and analyzed to define the geologic framework of the underlying basement. The lineaments were digitized, and length-weighted frequency distributions were calculated at 5° intervals on a 10-km2 grid. Statistically significant peaks (> 95%) and troughs (< 5%) within each cell were identified. These significant trends identify 13 major lineament zones, which in turn were compared with structural domains recognized from a combined interpretation of geophysical, subsurface form-surfaces, and basement well-log data. Correlation between lineament frequency, aeromagnetic, and gravity data was tested on a regionwide and smaller domain basis. The major lineament zones divide the western part of the area into north-south and northeast-southwest bound rhomboidal blocks. The eastern part is characterized by north-south and northwest-southeast bound rectangular blocks, quite different from the regional Appalachian grain. The lineament zones are documented to parallel basement domain boundaries because subsurface structure, lithologic and stratigraphic changes, and steep geophysical gradients occur along their extent. Some End_Page 1450------------------------------ lineament zones clearly cut across several stratigraphic levels, indicating Mesozoic and Cenozoic reactivation of favorably oriented preexisting basement faults. The depositional control of sedimentary units, fracture propagation due to basement-block tectonics, and apparent reversals of fault movement observed at the surface are also suggested in a conceptual model. End_of_Article - Last_Page 1451------------
ACCUMULATION OF BORON BY RECIPROCALLY GRAFTED PLANTS.

The experimental data presented in this paper show that the amount of boron accumulated by plants may be materially influenced by the rootstock. The boron relations of agricultural plants have been found to be diverse and the characteristics of boron accumulation are in some measure differentiated from the accumulation characteristics of other elements. Certain facts in this regard, illustrated in the following three paragraphs and more extensively presented elsewhere (1), provide in a measure a background for the experimental results here to be considered. An outstanding variability exists in the extent to which different plants take up boron. The boron concentrations resulting in entire plants, expressed in parts per million on the basis of dry weights, when grown in sand cultures maintained with a nutrient solution containing 5 p. p.m. of the element, were as follows : Navy beans 648, lima beans 515, wheat 453, pumpkin 291, lettuce 261, turnips 245, Canadian field peas 207, tomatoes 159, alfalfa 139, Acala cotton 123, asparagus 120, and carrots 69. The distribution of boron throughout a plant is not uniform ; it tends to accumulate in some parts more than in others. The leaves of rooted lemon cuttings grown in the cultures just mentioned contained 1232 p.p.m. of boron and the combined stems and roots 54 p.p.m. Young elms had 943 p.p.m. in their leaves and 22 p.p.m. in their stems ; corn had 60 p.p.m. in the combined leaves, stalks, and roots and 16 p.p.m. in the grain; roses had 220 p.p.m. in their leaves and 20 p.p.m. in their stems. Twigs of boron-injured prune trees in an orchard planting contained 176 p.p.m. of boron in their leaves, i Special acknowledgment is made of the indispensable analytical work carried out by V. P. Sokoloff and L. V. Wilcox.
Time-dependent loss of surface complement regulatory activity during storage of donor blood.

The survival of transfused red cells (RBCs) diminishes with time of in vitro storage in blood banks, but the molecular mechanisms underlying the slow but incessant deterioration are incompletely understood. To investigate the possibility that impaired resistance to autologous complement attack could play a role in this phenomenon, packed RBCs stored for variable periods were assayed for decay-accelerating factor (DAF) and CD59, two glycoinositol-phospholipid (GPI)-anchored, membrane- associated complement regulatory proteins that function physiologically to protect blood cells from autologous complement activation on their surfaces. Immunoradiometric and flow cytometric assays employing DAF and CD59 monoclonal antibodies showed that levels of both surface proteins gradually declined over 6 weeks. Digestion analyses with phosphatidylinositol-specific phospholipase C, an enzyme that releases GPI-anchored proteins from cell surfaces, showed that DAF and CD59 molecules with GPI anchors containing unacylated inositol were preferentially lost. These findings suggest: 1) that DAF and CD59 molecules with acylated GPI anchors are more stable in RBC membranes than are molecules with unacylated GPI anchors, and 2) that DAF and CD59 loss may participate with other membrane alterations that occur during in vitro storage in compromising the survival of transfused cells.
Rectification of a Sinusoidally Modulated Carrier in the Presence of Noise

The low-frequency output, signal and noise, is determined following a general νth-law (ν/>0) half-wave rectification of a sinusoidally modulated carrier. The spectral width of the noise before rectification is assumed to be much narrower than its mean frequency f 0 , the normal condition for reception. Attention is focused on one of the harmonics of the rectified signal, generally the first, whose modulation frequency is small compared to the if frequency f 0 and to the width of the noise band. Special attention is given to the important cases of linear (ν=1) and quadratic (ν=2) detection, and audio signal-to-noise ratios s a /n a are calculated for them. The noise passed by the audio filter is found to depend on the spectral shape of the if; for the three types of if filter specifically considered, namely, rectangular, gaussian, and "optical," the optical yields the least, the rectangular the most noise; provided, of course, that the mean input signal-to-noise power p is of the order of unity or less, the customary region of interest. When p 0) behave like the quadratic device. Modulation (O≦λ≦1) does not radically affect the output noise power, particularly when (p>1), and for very large signals, p→∞, s a /n a is directly proportional to the input carrier amplitude, is independent of if filter width, and is only slightly dependent on filter shape. The best if filter is one whose response is the modulus of the Fourier transform of the signal, as in the radar case of pulsed signals.
A B3LYP hybrid density functional theory study of structural properties, energies, and heats of formation for silicon–hydrogen compounds

Abstract A high level of ab initio and B3LYP hybrid density functional studies were performed with the target being to determine both the reliability of these two methods for computing energetic properties of small silicon–hydrogen compounds, and the accuracy of the currently available thermodynamic properties of these compounds. These energies are Si–H and Si–Si bond dissociation energies, atomization energies, and heats of formation. The hybrid B3LYP ab initio computational study was performed in combination with five different basis sets. Currently available experimental energies for these compounds have a large experimental error, but with the CBSQ(0 K) energies it was possible to narrow these experimental values. In general, the B3LYP hybrid DFT method with a large basis set computes energies that are slightly below the CBSQ values.
Factors affecting the appearance of a pre-peak during crossed immunoelectrophoresis of factor VIII related antigen

Abstract Conditions were examined which elicit “pre-peak” formation during crossed immunoelectrophoresis (CIEP) of normal, human factor VIII related antigen (FVIII:RAg). Pre-peak artifacts could be induced by sample handling conditions leading to cryoprecipitate, platelets or platelet fragments in the plasma. Under conditions not promoting pre-peak artifacts, only 25% of the hemophilic samples tested showed pre-peaks. No other abnormality tested produced pre-peaks with the exception of samples from recently infused patients. Pre-peaks appear, therefore, to be of limited predictive value.
Lipid nanocapsule as vaccine carriers for his-tagged proteins: evaluation of antigen-specific immune responses to HIV I His-Gag p41 and systemic inflammatory responses.

The purpose of this study was to design novel nanocapsules (NCs) with surface-chelated nickel (Ni-NCs) as a vaccine delivery system for histidine (His)-tagged protein antigens. Ni-NCs were characterized for binding His-tagged model proteins through high affinity non-covalent interactions. The mean diameter and zeta potential of the optimized Ni-NCs was 214.9 nm and - 14.8 mV, respectively. The optimal binding ratio of His-tagged Green Fluorescent Protein (His-GFP) and His-tagged HIV-1 Gag p41 (His-Gag p41) to the Ni-NCs was 1:221 and 1:480 w/w, respectively. Treatment of DC2.4 cells with Ni-NCs did not result in significant loss in the cell viability up to 24 h (<5%). We further evaluated the antibody response of the Ni-NCs using His-Gag p41 as a model antigen. Formulations were administered subcutaneously to BALB/c mice at day 0 (prime) and 14 (boost) followed by serum collection on day 28. Serum His-Gag p41 specific antibody levels were found to be significantly higher at 1 and 0.5 μg doses of Gag p41-His-Ni-NCs (His-Gag p41 equivalent) compared to His-Gag p41 (1 μg) adjuvanted with aluminum hydroxide (AH). The serum IgG2a levels induced by Gag p41-His-Ni-NCs (1 μg) were significantly higher than AH adjuvanted His-Gag p41. The Ni-NCs alone did not result in elevation of systemic IL-12/p40 and CCL5/RANTES inflammatory cytokine levels upon subcutaneous administration in BALB/c mice. In conclusion, the proposed Ni-NCs can bind His-tagged proteins and have the potential to be used as antigen delivery system capable of generating strong antigen specific antibodies at doses much lower than with aluminum based adjuvant and causing no significant elevation of systemic proinflammatory IL-12/p40 and CCL5/RANTES cytokines.
Family level classification within Thylacocephala, with comments on their evolution and possible relationships

Thylacocephala are among the most problematic of arthropod fossils. Various authors have allied them with all manner of crustacean groups, including branchiopods, cirripedes, remipedes, and malacostracans. They have a very apomorphic body plan often marked by hypertrophy of the compound eyes, three pairs of large raptorial subchelate limbs, eight sets of well-developed phyllobranch gills, and from 8 to at least 16 posterior trunk somites bearing paddle-like limbs. They have been thought of as a distinct class composed of two orders, Concavicarida and Conchyliocarida, but membership within the orders varies according to authors, and no familial divisions have been proposed within the orders until now. This lack of taxonomic structure inhibits organization of available information concerning the paleoecology, paleogeography, and phylogenetic relationships of thylacocephalans. A working hypothesis for the higher taxonomy within the class is proposed here. This entails a redefinition of the two orders, and recognition of seven families, five of them new: Austriocarididae Glaessner, 1931, Clausocarididae Arduini, 1992 (new status), Concavicarididae n. fam., Dollocarididae, n. fam., Microcarididae n. fam., Ostenocarididae n. fam. and Protozoeidae n. fam.
Mechanism of histamine binding I: Effect of calcium on binding of histamine to a plasma peptide

A method of isolating a single polypeptide from human plasma, termed peptide H for its histaminopexic or histamine-binding capability, is described. The peptide was obtained by acid precrystallization of human plasma, followed by water extraction of the precipitate and separation on an ion-exchange column. A molecular weight of 4492 was calculated from amino acid analysis. A dynamic dialysis technique was used to study the binding of histamine to peptide H. No binding of histamine to peptide H was observed in the absence of Ca+ 2; however, in the presence of Ca+ 2, binding of histamine to peptide H did occur. It was determined that histamine first forms a complex with Ca+ 2, with subsequent binding of the Ca+ 2-histamine complex to peptide H. From the dialysis data and kinetic analysis, it was possible to demonstrate that the data are consistent with a peptide having three binding sites for the Ca+ 2-histamine complex, two fast sites and one slow site.
A Time-Resolved SERS Study of the Adsorption and Electrochemical Reduction of 4-Pyridinecarboxaldehyde and 4-(Hydroxymethyl)pyridine

The electroreduction processes of both 4-pyridinecarboxaldehyde, 4-ALPY, and 4-(hydroxymethyl)pyridine, 4-HMPY, have been studied in aqueous solution on a Ag electrode using surface-enhanced Raman ...
Chlorhexidine-Containing Cavity Disinfectant may not Benefit the Clinical Performance of High-Viscosity Glass-Ionomer Cement Following ART After 24 Months

Article Title and Bibliographic Information The effect of a chlorhexidine containing cavity disinfectant on the clinical performance of high-viscosity glass-ionomer cement following ART: 24-month results. Ersin NK, Aykut A, Candan U, Oncag O, Eronat C, Kose T. Am J Dent 2008;21(1):39-43. Level of Evidence Level 2: Limited-quality, patient-oriented evidence. Strength of Recommendation Grade Not applicable. Purpose/Question To evaluate the effect of a chlorhexidine-gluconate–based cavity disinfectant on the clinical performance of a high-viscosity glass-ionomer cement following the ART approach after 24 months. Source of Funding Information not available. Type of Study/Design Cohort study.
Panic disorder: Assessment and treatment

Abstract Current research on anxiety has supported the classification of panic disorder as a distinct clinical entity characterized by spontaneously occurring panic attacks in the absence of recognizable fear-provoking stimuli. The problems of psychological and medical differential diagnosis are reviewed. Psychodynamic, psychobiological, and behavioral theories of panic disorder are reviewed and evaluated as to treatment outcome. Psychodynamic treatment is found to lack empirical support. While psychopharmacological treatments, such as tricyclic antidepressants, have proven successful in dealing with panic attacks associated with debilitating agoraphobia, treatment effects do not last. Moreover, the drugs do not appear to reduce anticipatory anxiety, a key feature of panic disorder. Behavioral conceptualization and treatment of panic disorder has been confined to panic in agoraphobia. It is suggested that a cognitive-behavioral conceptualization could lead to effective treatment of panic disorder.
Differentiation of pathogenic and non-pathogenic serotype 1 Marek's disease viruses (MDVs) by the polymerase chain reaction amplification of the tandem direct repeats within the MDV genome.

SUMMARY. There are no simple, direct methods to reliably distinguish oncogenic serotype 1 Marek's disease viruses (MDVs) from their attenuated variants. The present study was an attempt to apply polymerase chain reaction (PCR) to develop a rapid and sensitive assay for the presence of the MDV genome. PCR oligos were chosen to flank the 132-base-pair tandem direct repeats in the serotype 1 MDV genome. The PCR reaction was specific for serotype 1 MDVs, amplifying fragments corresponding to one to three copies of the tandem repeats present in Mdll/8, JM/102W, and GA viruses. A high-molecular-weight DNA smear was observed when the DNA from an attenuated Mdll/100 was PCR-amplified. Use of the PCR technique allowed the detection of two copies of the 132-base-pair repeat in the DNA extracted from MDV-induced lymphomas removed from two chickens. No DNA was amplified from the DNA extracted from lymphomas induced by either an avian leukosis virus (RAV-1) or reticuloendotheliosis virus (chick syncytial virus).
Theoretic Criteria for Antibody Penetration into Solid Tumors and Micrometastases

Targeting tumors with antibody-based therapeutics is a complex task presenting multiple kinetic barriers. Antibody internalization and clearance inhibit uptake both in solid tumors, limited by tumor vascular permeability, and in micrometastases, limited by diffusion. Methods: A modeling exercise is used to introduce 2 simple criteria that must be less than unity for saturation of both tumors and micrometastases. The clearance modulus and the Thiele modulus are ratios of the plasma clearance rate and antibody catabolism, respectively, to the tumor tissue penetration rate. Results: Even low rates of antigen internalization from constitutive membrane turnover can significantly retard antibody penetration. Rapid clearance of single-chain variable fragments also hinders uptake, often more than counterbalancing their more rapid extravasation and diffusion. Conclusion: The model illustrates that with the large resistance from the tumor capillary, antibodies may be more suitable for targeting micrometastases than vascularized tumors.
Robotic perimeter detection system

Sandia National Labs is developing and testing a robotic perimeter detection system for small unit operations (small groups of warfighters). The objective is to demonstrate the feasibility of using a cooperative team of robotic sentry vehicles to assist the warfighter in guarding military assets. Eight 'Roving All Terrain Lunar Explorer Rovers' (RATLERs) have been built at Sandia and are being used as the test platform. A radio frequency receiver on each of the RATLERs alerts the sentry vehicles of alarms from hidden miniature intrusion detection sensors (MIDS). The MIDS currently deployed include seismic, magnetometer, passive and beam-break infrared sensor. Each RATTLER keeps an internal state representation of each of the MIDS and of the other vehicles' locations. This representation is updated several times per second as the vehicles broadcast their current state and any alarms received. When an alarm is received, each vehicle looks at this state information and decides whether it should investigate the alarm based on the proximity of itself and the other vehicles to the alarm. As one vehicle attends an alarm, the other vehicles adjust their position around the perimeter to better prepare for another alarm. This cooperative team concept can significantly reduce the workload and increase the effectiveness of a single warfighter in the battlefield. Using robot vehicles makes the perimeter detection system easily mobilized for redeployment.© (1999) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Caring for incarcerated youth.

Purpose of review Incarcerated youth are an unusually high-risk cohort with numerous unmet medical and psychiatric needs. Frequently seen medical conditions including sexually transmitted diseases, pregnancy, and psychiatric illness are reviewed along with recommended standards of care for this population. Recent findings The recent realization that two-thirds of juvenile detainees have a psychiatric disorder has sparked renewed interest in screening and treating these high-risk adolescents. The push for increased identification and treatment has been prompted by the hypothesis that treating illness reduces recidivism and therefore improves individual and community public health. Although many facilities perform psychiatric and medical health screening within 24 hours of detention, there are many lacking areas. Examples include limited sexually transmitted disease, HIV and pregnancy testing; given the high rates of asymptomatic sexually transmitted disease infection, universal screening is essential. Also, interpretation of psychiatric screening tools by untrained individuals and utilization of results to incriminate juveniles are other problem areas. Summary Incarcerated adolescents' time in detention represents a rare opportunity to provide care to this underserved population. Full implementation of recommended screening and assessment protocols could greatly enhance individual as well as community health.
High average power fs frequency comb via injection locked amplification for intracavity HHG

We demonstrate a scalable approach for the generation of high average power ultrashort pulse trains (~7 W) by optically injection locking a fs amplification cavity. The source is used as a seed for intracavity HHG.
Learning linear threshold functions in the presence of classification noise

I show that the linear threshold functions are polynomially learnable in the presence of classification noise, i.e., polynomial in n, 1/e, 1/δ, and 1/s, where n is the number of Boolean attributes, e and δ are the usual accuracy and confidence parameters, and s indicates the minimum distance of any example from the target hyperplane, which is assumed to be lower than the average distance of the examples from any hyperplane. This result is achieved by modifying the Perceptron algorithm—for each update, a weighted average of a sample of misclassified examples and a correction vector is added to the current weight vector. Similar modifications are shown for the Weighted Majority algorithm. The correction vector is simply the mean of the normalized examples. In the special case of Boolean threshold functions, the modified Perceptron algorithm performs O (n2e−2 ) iterations over O(n4e −2ln(n/(δe))) examples. This improves on the previous classification-noise result of Angluin and Laird to a much larger concept class with a similar number of examples, but with multiple iterations over the examples.
An optimized algorithm for the detection of uterine contractions in intrauterine pressure recordings.

A previously designed test program for the determination of the temporal characteristics of intrauterine pressure data detects the onset time, the peak time and the end time of uterine contractions utilizing simple methods of calculus (Am. J. Obstet. Gynec., 120: 496(1974)). The basic algorithm has been improved by a routine which maximizes the cross-correlation coefficient between a set of visually generated event flags and the program generated event flags. The optimized set of logic generates a cross-correlation coefficient of 0.753 for a data file with selected artifact conditions. The corresponding outcome for that portion of the file with an absence of artifacts is as high as 0.899.
United States uranium resources the 1975–2000 outlook

Abstract The status of uranium resources for the USA for the period 1975–2000 can only be estimated within rather broad limits due to a complex interplay of the many factors involved. Minimum estimates for uranium oxide requirements to fuel light water nuclear reactors (LWRs) alone range from 2 × 10 6 to 2.25 × 10 6 tonnes U 3 O 8 . These limits are deemed reasonable due to the unlikelihood of a firm commitment to the use of fast breeder reactors (FBRs) by the government; tentative decision dates range from 1988 to 2000 or so but, even presuming the former, the impact on uranium needs will not be felt until after 2000. A wider use of converter reactors may lighten the eventual uranium needs close to 2000. These reactors, however, were originally planned only for interim use during the change-over from LWRs to FBRs; hence their increased use will not affect the uranium demand until the next century. Present plans call for an accelerated exploration and development programme involving federal and state agencies with industry and other sources.
Metal-oxide surfaces

Over the past two decades the amount of effort devoted to the study of metal oxides by surface scientists has increased significantly. The general characteristics of the electronic structure of metal-oxide surfaces are now fairly well understood, although transition-metal oxides have been more thoroughly studied than have non-transition-metal oxides. The geometric arrangement of atoms on the surfaces of a variety of metal oxides has also been determined. Extensive studies have been performed of the interaction of both molecules and metal atoms with metal oxides, where point defects are found to play a dominant role. However, our understanding of the surface properties of metal oxides is still much less compete than it is for metals and semiconductors, and there are several areas where more experimental and theoretical effort needs to be concentrated.