cssi/SciSciGPT-SciSciNet huggingface dataset:
Response of liquid flow resistance to soil drying in seedlings of four deciduous angiosperms.

Soil-leaf resistance to liquid water flow (R) in moist and drying soil was compared in three-month-old seedlings of two drought tolerant (white [Quercus alba L.], post oak [Q. stellata Wangenh.]) and two drought sensitive forest species (sugar maple [Acer saccharum Marsh.], black walnut [Juglans nigra L.]). At high soil moisture (Ψs≥-0.3 MPa), R was higher in J. nigra than in the other species, and as soil water was depleted R increased most in this species. In contrast, the lowest resistance at all levels of soil moisture was observed in Q. stellata. At Ψs of -1.5 MPa, R of drought-sensitive J. nigra and A. saccharum was about twice as high as that of the two drought-tolerant Quercus species. The difference in R between the two Quercus species was much smaller than that between this pair and the other two species. These differences among species in flow resistance may be attributable to: 1) variation in the balance between root surface area and leaf area, 2) variation in the inherent absorption capacity of the root systems and in xylem water conducting systems or 3) differences in root permeability, shrinkage and mortality in severely stressed seedlings. As the soil dried, seedlings of all species exhibited pronounced reductions in transpiration rate, which prevented development of large water potential gradients between leaves and the soil. Reduction in transpiration in J. nigra was especially pronounced, resulting in a decrease in the soil-to-leaf water potential gradient in dry soil despite high flow resistance. The observed differences among species in flow resistance are correlated with natural distribution patterns.
Visually lossless compression of digitized radiographs based on contrast sensitivity and visual masking

A visually lossless compression algorithm for digitized radiographs, which predicts the maximum contrast that wavelet subband quantization distortions can exhibit in the reconstructed image such that the distortions are visually undetectable, is presented. Via a psychophysical experiment, contrast thresholds were measured for the detection of 1.15-18.4 cycles/degree wavelet subband quantization distortions in five digitized radiographs; results indicate that digitized radiographs impose image- and frequency-selective effects on detection. A quantization algorithm is presented which predicts the thresholds for individual images based on a model of visual masking. When incorporated into JPEG-2000 and applied to a suite of images, results indicate that digitized radiographs can be compressed in a visually lossless manner at an average compression ratio of 6.25:1, with some images requiring visually lossless ratios as low as 4:1 and as great as 9:1. The proposed algorithm thus yields images that require the minimum bit-rate such that the reconstructed images are visually indistinguishable from the original images. The primary utility of the proposed algorithm is its ability to provide image-adaptive visually lossless compression, thereby avoiding overly conservative or overly aggressive compression.
Approximating image filters with box filters

Box filters have been used to speed up many computation-intensive operations in Image Processing and Computer Vision. They have the advantage of being fast to compute, but their adoption has been hampered by the fact that they present serious restrictions to filter construction. This paper relaxes these restrictions by presenting a method for automatically approximating an arbitrary 2-D filter by a box filter. To develop our method, we first formulate the approximation as a minimization problem and show that it is possible to find a closed form solution to a subset of the parameters of the box filter. To solve for the remaining parameters of the approximation, we develop two algorithms: Exhaustive Search for small filters and Directed Search for large filters. Experimental results show the validity of the proposed method.
Cre-ating Somatic Cell Genetic Mosaics in the Mouse

Generation of somatic mosaics in which mutant cell clones are uniquely and completely labeled has yielded considerable insight into many biological processes in Drosophila. In this issue of Cell, Zong et al. (2005) describe a novel method called MADM that allows the generation of such mosaics in mice.
Effects of cold and hypoxia on ventilation and oxygen consumption in awake guinea pigs

Abstract Ventilation and oxygen consumption were measured in awake, unrestrained and unintubated guinea pigs during chronic and acute exposure to cold or hypoixa. Specific Ve and VO2 in acute and chronic exposure to cold were more than twice that of animals in normal environmental temperatures. Increased ventilation was mainly due to a 70% greater Vt in cold. Cold-acclimated guinea pigs returned acutely to normal temperatures, maintained higher Ve and VO2 than that of control animals. Acelimation to cold did not result in respiratory advantages over that of control animals acutely exposed to cold. In Hypoxia-acclimated guinea pigs, specific Ve was 30% higher than that of control animals due to an elevation in Vt ; however, VO2 was similar in both group of animals. In contrast, acute hypoxia did not increase Ve in control animals. This lack of ventilatory response to acute hypoxia apparently causes the marked erythropoiesis and the severe increase in hematocrit observed throughout chronic exposure to hypoxia. The high blood viscosity resulting from the increased hematocrit contributes to the right ventricular hypertrophy and cardiac failure in guinea pigs chronically exposed to hypoxia.
An Advanced Organometallic Lab Experiment with Biological Implications: Synthesis and Characterization of Fe2(μ-S2)(CO)6

The organometallic complex Fe2(μ-S2)(CO)6 has interesting biological implications. The concepts of bio-organometallic chemistry are rarely discussed at the undergraduate level, but this experiment can start such a conversation and, in addition, teach valuable synthetic techniques. The lab experiment takes a total of five, 3-h lab periods and includes synthesis, purification, and characterization of the title molecule. The synthesis is done using standard Schlenk line techniques, but the product is air stable, which allows for standard benchtop purification. The compound is characterized using UV–vis spectroscopy, Fourier transform infrared spectroscopy, 13C NMR spectroscopy, and mass spectrometry.
Characteristics of opportunities search of entrepreneurs versus executives: Sources, interests, general alertness

Abstract A recent article by Low and MacMillan (1988) suggests that at the current stage of entrepreneurship research, empirical studies that “are not theory driven and do not test hypotheses are no longer acceptable” (p. 155). This paper is written in the spirit of this directive. It starts with an explicit theory of entrepreneurship developed by Israel Kirzner, and tests three hypotheses derived from the theory. The theoretical thrust of the paper emphasizes the role of information and information-seeking behavior as a central element of entrepreneurial behavior. Entrepreneurship is based on discovering of opportunities and resources to exploit them. Our interpretation of Kirzner's theoretical works leads to the formation of hypotheses regarding the differences that should exist in the way entrepreneurs as opposed to managers seek this information. These concern: (1) differences in the manner in which entrepreneurs and corporate managers expose themselves to information; (2) differences in the sources of information used; and (3) differences in evaluating information cues. In addition, we test the hypotheses that success and experience will erode the above differences between entrepreneurs and corporate managers. Our sample involved 51 founders of companies in New Jersey and 36 executives of a very large financial company. A questionnaire was used to gather the data, and scales were formed using principal component factor analysis with a varimax rotation. Differences were tested using univariate and multivariate statistical methods. Significant differences were found in five of the nine factors examined. Entrepreneurs spent significantly more time searching for information in their off hours and through nonverbal scanning. They employed different sources than executives and paid special attention to risk cues about new opportunities. Executives, on the other hand, tended to focus on the economics of the opportunity. These results are only partially consistent with a previous study comparing entrepreneurs and small companies' managers, suggesting a contextual contingency to the behaviors under study. The most persistent finding was regarding the time and “volume” of search for information, reinforcing the idea developed in the recent network theory of entrepreneurship that entrepreneurs are avid information-gatherers and opportunistic learners, but not necessarily, or not uniquely in a verbal, social-networking manner. Finally, with success and experience, the differences become smaller. It seems that success and experience reduce the need or desire of entrepreneurs to search for new opportunities. No such effect was found with our executive sample.
Sublethal Effects of Carbaryl Bran Bait on Nesting Performance, Parental Investment, and Offspring Size and Sex Ratio of the Alfalfa Leafcutting Bee (Hymenoptera: Megachilidae)

Megachile rotundata (F.) was used to study sublethal effects of carbaryl bran bait on a representative solitary nesting bee. Adult females were fed a 25% honey solution contaminated with 2 mg of commercially formulated carbaryl bran bait (2% [AI]) for 4 d and then were released into a greenhouse to nest in wooden blocks. Bees fed contaminated honey performed as well as bees fed plain honey solution. No differences were observed in number of days spent nesting, rate of cell production, offspring survival, investment in offspring, or offspring weight and sex ratio between carbaryl-treated and control bees. Diapausing bees from both carbaryl and control treatments tended to be larger than those emerging in the same season (emergent bees). We also found no sublethal effects on M. rotundata larvae. Larvae fed provisions contaminated with 1 or 2 mg of carbaryl bran bait gained as much body weight as those fed uncontaminated provisions. We conclude that the 2% [AI] carbaryl formulation of bran bait is likely to be the least detrimental to solitary bee pollinators of any insecticide thus far used to control grasshoppers on rangeland
States of Light Nuclei from the jj Coupling Model

The ordering of energy levels is presented for $1p$ shell nuclei in the $\mathrm{jj}$ coupling model. Comparison of the $\mathrm{jj}$ and $\mathrm{Ls}$ model predictions with experiment are given for angular momenta and magnetic moments of the ground states as well as for the shape of the binding energy curve. No decisive favoring of either model is evident.
NEOS: the North East Ocean Observing System by: Scott Glenn & NEOS partners

Ocean.US is coordinating the development of a National Federation of Regional Associations of Coastal Ocean Observing Systems. It is anticipated that on the order of ten regional associations will evolve. These associations will coordinate regional enhancements of the existing and expanding national backbone of coastal ocean observations.
INTERSTELLAR ABSORPTION OF COSMIC X RAYS.

Improved results on the total photo-ionization cross section of atomic helium are given. The total cross section includes contributions from simultaneous ionization and excitation of ${\mathrm{He}}^{+}$ and double ionization; the combined effect of these two processes adds about 10% to the normal photo-ionization process where ${\mathrm{He}}^{+}$ is left in the ground state. A lower abundance (10.92 based on 12.00 for hydrogen) is adopted for helium, based on recent radio determinations. In calculating the opacity due to $K$-shell photo-ionization of heavy elements, a lower abundance (8.00) is also adopted for neon. Brief mention is made of the effects of irregularities in the density distribution of the interstellar gas on the problems of both x-ray and radio-wave absorption.
Research on Hierarchical File System for Embedded Linux

Based on the deep analysis of the VFS mechanism, a hierarchical file system based on embedded Linux is designed and implemented by combining the kernel module and user service application. It provides both the convenient update of the system and the better protection of the read-only system files, which is obviously of great value in commercial purposes.
PM-11DEVELOPMENT OF A HUMAN MENINGIOMA MOUSE XENOGRAFT MODEL WITH THE SPONTANEOUSLY IMMORTAL CELL LINE KCI-MENG1.

BACKGROUND: There is a paucity of effective therapies for recurrent/aggressive meningiomas. Establishment of improved in vitro and in vivo meningioma models will facilitate development and testing of novel therapeutic approaches. METHODS: A primary meningioma cell line was generated from a patient harboring a WHO grade I olfactory groove meningioma. The cell line was extensively characterized by performing analysis of growth kinetics, immunocytochemistry, telomerase activity, karyotype, and genomic analysis. A xenograft model of human meningioma using immunocompromised SCID mice was also developed. RESULTS: Histopathology was consistent with a WHO grade I typical meningioma composed of meningothelial cells, whorls, and psammoma bodies. The original tumor and the early passage primary cells shared the standard immunohistochemical profile. Low-passage KCI-MENG1 cells were composed of two cell types with spindle and round morphologies, showed linear growth curve, had very low telomerase activity, and were composed of two distinct unrelated clones on cytogenetic analysis. In contrast, high-passage cells were homogeneously round, rapidly growing, had high telomerase activity, and were composed of a single clone with a near triploid karyotype containing 64-66 chromosomes with numerous aberrations. Following subcutaneous transplantation of low- or high-passage cells into SCID mice, tumor tissue with typical histological features of meningothelial meningioma was found. Cultured cells isolated from the xenograft tumors also had the near-triploid karyotype and the same immunostaining profile. CONCLUSIONS: The newly-established spontaneously immortal KCI-MENG1 meningioma cell line and human meningioma mouse xenograft model will provide a biologically relevant platform from which to investigate meningioma tumor biology and disease progression as well as to develop novel therapeutic targets to improve treatment options for all grades of meningiomas.
Change Management in Enterprise IT Systems: Process Modeling and Capacity-optimal Scheduling

We provide a formal model for the Change Management process for Enterprise IT systems, and develop change scheduling algorithms that seek to attain the "change capacity" of the system. The change management process handles critical updates in the system that often use overlapping sets of servers, resulting in scheduling conflicts between the corresponding change classes. Furthermore, applications are typically associated with certain permissible downtime windows, which impose constraints on the timing of the change executions. Scheduling of changes for such systems represent a complex dynamic optimization question. In a limiting fluid regime, where changes are assumed nonatomic, we develop a scheduling policy that provably attains the change capacity of the system. We then propose and evaluate an atomic approximation of the optimal fluid scheduling policy, which is well suited for application to a real change management system. Simulation results demonstrate that the expected change execution delay and the capacity attained by the approximate policy is close to the best attainable values, when unavoidable capacity losses due to fragmentation effects are taken into account and is significantly better than a randomized scheduling policy.
Childhood body mass index gain during the summer versus during the school year

The nationwide increase in obesity affects all population sectors, but the impact on children is of special concern because overweight children are prone to becoming overweight adults. Contrary to the opinion of experts, research suggests that schools may be more part of the solution than the problem. Recent seasonal comparison research (comparing children's outcomes during the summer and during school year) reports that children gain body mass index (BMI) nearly twice as fast during the summer as during the school year. Whereas most children experience healthier BMI gain during the school year than the summer, this is especially the case for black and Hispanic children and for children already overweight.
Addressing Disaster Mental Health Needs of Children: Practical Guidance for Pediatric Emergency Health Care Providers

Emergency health care providers are often the first to respond to the needs of children after a disaster. Although there has been an increase in research related to the impact of disasters, including terrorist events, on children's mental health, physicians continue to cite a need for additional information and training on the topic. This article provides an overview of recent literature on disasters and mental health, covering children's stress reactions, mental health problems that may arise, and risk factors that affect these reactions. Practical guidance for pediatric emergency health care providers is emphasized, including psychological first aid, recommendations for screening questions to facilitate mental health triage, and an overview of effective mental health interventions. It concludes with a discussion of the impact of providing care in the aftermath of a disaster on the health care professional.
Specification and simulation of statistical query algorithms for efficiency and noise tolerance

A recent innovation in computational learning theory is the statistical query (SQ) model. The advantage of specifying learning algorithms in this model is that SQ algorithms can be simulated in the probably approximately correct (PAC) model, both in the absenceandin the presence of noise. However, simulations of SQ algorithms in the PAC model have non-optimal time and sample complexities. In this paper, we introduce a new method for specifying statistical query algorithms based on a type ofrelative errorand provide simulations in the noise-free and noise-tolerant PAC models which yield more efficient algorithms. Requests for estimates of statistics in this new model take the following form: “Return an estimate of the statistic within a 1±?factor, or return ?, promising that the statistic is less than?.” In addition to showing that this is a very natural language for specifying learning algorithms, we also show that this new specification is polynomially equivalent to standard SQ, and thus, known learnability and hardness results for statistical query learning are preserved. We then give highly efficient PAC simulations of relative error SQ algorithms. We show that the learning algorithms obtained by simulating efficient relative error SQ algorithms both in the absence of noise and in the presence of malicious noise have roughly optimal sample complexity. We also show that the simulation of efficient relative error SQ algorithms in the presence of classification noise yields learning algorithms at least as efficient as those obtained through standard methods, and in some cases improved, roughly optimal results are achieved. The sample complexities for all of these simulations are based on thed?metric, which is a type of relative error metric useful for quantities which are small or even zero. We show that uniform convergence with respect to thed?metric yields “uniform convergence” with respect to (?, ?) accuracy. Finally, while we show that manyspecificlearning algorithms can be written as highly efficient relative error SQ algorithms, we also show, in fact, thatallSQ algorithms can be written efficiently by proving general upper bounds on the complexity of (?, ?) queries as a function of the accuracy parameter?. As a consequence of this result, we give general upper bounds on the complexity of learning algorithms achieved through the use of relative error SQ algorithms and the simulations described above.
Nanotheranostics of Circulating Tumor Cells, Infections and Other Pathological Features In Vivo

Many life-threatening diseases are disseminated through biological fluids, such as blood, lymph, and cerebrospinal fluid. The migration of tumor cells through the vascular circulation is a mandatory step in metastasis, which is responsible for ∼90% of cancer-associated mortality. Circulating pathogenic bacteria, viruses, or blood clots lead to other serious conditions including bacteremia, sepsis, viremia, infarction, and stroke. Therefore, technologies capable of detecting circulating tumor cells (CTCs), circulating bacterial cells (CBCs), circulating endothelial cells (CECs), circulating blood clots, cancer biomarkers such as microparticles and exosomes, which contain important microRNA signatures, and other abnormal features such as malaria parasites in biological fluids may facilitate early diagnosis and treatment of metastatic cancers, infections, and adverse cardiovascular events. Unfortunately, even in a disease setting, circulating abnormal cells are rare events that are easily obscured by the overwhelming background material in whole blood. Existing detection methods mostly rely on ex vivo analyses of limited volumes (a few milliliters) of blood samples. These small volumes limit the probability of detecting CTCs, CECs, CBCs and other rare phenomena. In vivo detection platforms capable of continuously monitoring the entire blood volume may substantially increase the probability of detecting circulating abnormal cells and, in particular, increase the opportunity to identify exceedingly rare and potentially dangerous subsets of these cells, such as circulating cancer stem cells (CCSCs). In addition, in vivo detection technologies capable of destroying and/or capturing circulating abnormal cells may inhibit disease progression. This review focuses on novel therapeutic and diagnostic (theranostic) platforms integrating in vivo real-time early diagnosis and nano-bubble based targeted therapy of CTCs, CECs, CBCs and other abnormal objects in circulation. This critical review particularly focuses on nanotechnology-based theranostic (nanotheranostic) approaches, especially in vivo photoacoustic (PA) and photothermal (PT) nanotheranostic platforms. We emphasize an urgent need for in vivo platforms composed of multifunctional contrast nanoagents, which utilize diverse modalities to realize a breakthrough for early detection and treatment of harmful diseases disseminated through the circulation.
Quantitative evaluation of mammalian skeletal muscle as a heterologous protein expression system.

Abstract The production of mammalian proteins in sufficient quantity and quality for structural and functional studies is a major challenge in biology. Intrinsic limitations of yeast and bacterial expression systems preclude their use for the synthesis of a significant number of mammalian proteins. This creates the necessity of well-identified expression systems based on mammalian cells. In this paper, we demonstrate that adult mammalian skeletal muscle, transfected in vivo by electroporation with DNA plasmids, is an excellent heterologous mammalian protein expression system. By using the fluorescent protein EGFP as a model, it is shown that muscle fibers express, during the course of a few days, large amounts of authentic replicas of transgenic proteins. Yields of ∼1 mg/g of tissue were obtained, comparable to those of other expression systems. The involvement of adult mammalian cells assures an optimal environment for proper protein folding and processing. All these advantages complement a methodology that is universally accessible to biomedical investigators and simple to implement.
Variations in Zebra Mussel (Dreissena polymorpha) Veliger Densities throughout 1996 at Dam 52 on the lower Ohio River

ABSTRACT Zebra mussel veliger densities were monitored throughout 1996 at Lock and Dam 52 on the lower Ohio River near Brookport, IL. The spawning season occurred between mid June and early September with veliger densities peaking at 30,000/m3 in late June. Veliger first appeared at a water temperature of 21° C. When spawning ended in September the water temperature was 22 °C. Veligers were found throughout November when the water temperature was 10 °C. The lowest temperature at which veligers were observed was 7 ° C in March 1996. These results show that the zebra mussels in the lower Ohio River are reproducing naturally and that spawning appears to be synchronous. The presence of larvae at low temperatures in March suggests that veligers are capable of delaying settlement and overwintering in the planktonic stage.
Money-mediated disequilibrium processes in a pure exchange economy

Abstract Studied here are dynamical processes of money-mediated exchange and price adjustment in a pure exchange economy of durables. The processes take place in continuous time and are specified by fields of cones which define admissible trajectories in price-allocation or allocation space. Under strong classical assumptions on preferences and fairly mild behavioral assumptions, stability theorems are proved, showing that our processes converge to price equilibria.
Case of persistent left superior vena cava draining via the left atrium with a normal coronary sinus utilizing cardiac CT

With an estimated incidence of ≈ 0.5%-2% of the population and 10% of patients with congenital heart disorders, persistent LSVC is the most common venous anomaly of the chest. Most drain via the right atrium. Rarely (7.5% of cases), the persistent LSVC may drain directly into the left atrium. These are typically seen with a coronary sinus type atrial septal defect with many investigators believing that, embryologically, a normal coronary sinus cannot exist in the setting of a persistent LSVC draining into the left atrium. There have been few case reports of this in the setting of a normal coronary sinus. With the assistance of cardiac CT, we were able to show the existence of this rare entity. The CT images provided guidance for a successful endovascular repair.
Preliminary studies of the distribution of auroras in Alaska

The analysis of auroral observations for 1951–53 from five stations spread over Alaska shows a zone at geomagnetic latitude 68° for which the incidence of auroras is independent of magnetic activity. At geomagnetic latitudes south of 67° the incidence of auroras is markedly dependent upon magnetic activity.
Long-term ovarian and gonadotropin changes in mice exposed to 4-vinylcyclohexene.

Abstract This study investigated the relationships between 4-vinylcyclohexene-induced follicular destruction, plasma FSH levels, and the development of ovarian preneoplastic changes. Female, 28-day-old, B6C3F1 mice were administered VCH (800 mg/kg/day, ip) or sesame seed oil, ip daily for 30 days. At 30, 60, 120, 240, and 360 days following the beginning of treatment, groups were killed, their ovaries were harvested, and plasma was collected for measurement of FSH. Ovarian weight was less and oocytes contained in preantral follicles were significantly fewer than controls at all time points. Plasma FSH concentrations in VCH-treated animals were increased significantly above controls at 240 d and 360 d. Histologically, there was oocyte loss at all times, whereas at 240 and 360 days, small to medium. irregularly shaped foci of hypertrophic cells were present. In addition, at 360 days 80% of the VCH-treated mice had a 1- to 2-mm, blood-filled cystic structure present in one or both ovaries. These studies indicate that VCH-induced oocyte destruction and follicle loss are associated with increases in plasma FSH, are associated with ovarian failure at 360 days, and are temporally related to ovarian cellular hypertrophy and the formation of blood-filled cystic ovarian structures. These events are possibly related to ovarian neoplasms produced by long-term exposure to VCH.
The marketplace and electronic government information

Abstract This article discusses the critical economic impact of government produced electronic information. The contradictions inherent in the current marketplace are drawn, with special emphasis on how these affect the individual citizen. It is asserted that government agencies should provide citizens with broad and low-cost access to government information. Agencies should also use the most modern types of technology to disseminate information and to provide so-called value-added services to make that information useful.
PEP-II at 1.2×1034/cm2/s luminosity

PEP-II is an asymmetric e+-e- collider operating at the Upsi(4S) energy and has recently set several performance records. The luminosity has reached a peak of 1.2 x 1034 cm-2 s-1. Operating in continuous injection mode for both beams PEP-II has delivered up to 0.91 fb-1 day-1. Peak currents have reached 3.0 A of positrons and 1.9 A of electrons in 1732 bunches. Total delivered luminosity since turn-on in 1999 has exceeded 450 fb-1. This paper reviews the present performance issues of PEP-II and also the planned increase of luminosity in the near future to 2 times 1034 cm-2 s-1.
Changes in abdominal motoneuron frequency correlated with changes of shell position in the hermit crabPagurus pollicarus

Changes in the frequency of motoneurons innervating the right medial region of the longitudinal portion of the ventral superficial muscles were studied under chronic conditions. Extracellular potentials were correlated with intracellularly recorded EJP's; these varied in frequency from zero to 20 Hz. When animals carried different weights on their shells, the frequency increased with the load. The frequency was unrelated to the magnitude of the weights hung on the abdomen of a restrained animal or to its position. It is suggested that load compensation is produced by stimulation of phasic mechanoreceptors located in the abdominal surface and that no mechanism for maintaining a constant shell position above the substrate exists.
Automated docking to multiple target structures: incorporation of protein mobility and structural water heterogeneity in AutoDock.

Protein motion and heterogeneity of structural waters are approximated in ligand-docking simulations, using an ensemble of protein structures. Four methods of combining multiple target structures within a single grid-based lookup table of interaction energies are tested. The method is evaluated using complexes of 21 peptidomimetic inhibitors with human immunodeficiency virus type 1 (HIV-1) protease. Several of these structures show motion of an arginine residue, which is essential for binding of large inhibitors. A structural water is also present in 20 of the structures, but it must be absent in the remaining one for proper binding. Mean and minimum methods perform poorly, but two weighted average methods permit consistent and accurate ligand docking, using a single grid representation of the target protein structures.
Deposition of Atomic Beams

The efficiency of sticking is known to be dependent on temperature of the surface. Knowledge in this field for the benefit of workers in molecular beams is reviewed. Particular emphasis is placed on condensation or sticking coefficients, critical temperatures for condensation, and binding energies of atoms on surfaces. Two theonies of deposition of atomic beams are reviewed. (W.D.W.)
The hereditary hemochromatosis protein, HFE, lowers intracellular iron levels independently of transferrin receptor 1 in TRVb cells

Hereditary hemochromatosis (HH) is an autosomal recessive disease that leads to parenchymal iron accumulation. The most common form of HH is caused by a single amino acid substitution in the HH protein, HFE, but the mechanism by which HFE regulates iron homeostasis is not known. In the absence of transferrin (Tf), HFE interacts with transferrin receptor 1 (TfR1) and the 2 proteins co-internalize, and in vitro studies have shown that HFE and Tf compete for TfR1 binding. Using a cell line lacking endogenous transferrin receptors (TRVb cells) transfected with different forms of HFE and TfR1, we demonstrate that even at low concentrations Tf competes effectively with HFE for binding to TfR1 on living cells. Transfection of TRVb cells or the derivative line TRVb1 (which stably expresses human TfR1) with HFE resulted in lower ferritin levels and decreased Fe2+ uptake. These data indicate that HFE can regulate intracellular iron storage independently of its interaction with TfR1. Earlier studies found that in HeLa cells, HFE expression lowers Tf-mediated iron uptake; here we show that HFE lowers non–Tf-bound iron in TRVb cells and add to a growing body of evidence that HFE may play different roles in different cell types.
Complications and survival associated with surgical compared with medical management of horses with duodenitis-proximal jejunitis.

Reasons for performing study: Based on clinical observation, it is hypothesised that horses with duodenitis-proximal jejunitis (DPJ) that are treated surgically have a shorter duration, smaller volume, and slower rate of nasogastric reflux (NGR) compared to horses treated medically, are more likely to develop diarrhoea than medically managed cases, and have a higher incisional infection rate than a sample population of horses undergoing abdominal exploration for gastrointestinal disease other than DPJ.Objectives: To compare: 1) duration, volume and rate of NGR and the percentage of horses with diarrhoea between medically and surgically treated DPJ cases; and 2) incisional infection rate in horses with DPJ undergoing abdominal exploration to a sample population of horses undergoing abdominal exploration for gastrointestinal disease other than DPJ.Methods: Medical records of cases with DPJ diagnosed 1995-2006 were reviewed. Information obtained included subject details, presenting clinical findings, treatment category (medical/surgical), complications (diarrhoea, incisional infection), and outcome (survival/nonsurvival). Data were analysed using a Chi-squared test and a mixed model analysis of variance. Level of significance was P<0.05.Results: Compared to medical cases, surgical cases had significantly decreased survival, a longer duration and larger total volume of NGR, and were more likely to develop diarrhoea. The incisional infection rate for horses with DPJ undergoing abdominal exploration was 16% compared to 7% for the sample population of horses.Conclusions: Surgical treatment of horses with DPJ did not lead to resolution of NGR faster than medical treatment. Surgical cases were more likely to develop diarrhoea and did not have a significantly higher incisional infection rate than the sample population.Potential relevance: Surgical intervention did not appear to lessen the volume or duration of NGR. It is mainly indicated as a diagnostic aid in cases of DPJ that are difficult to differentiate from small intestinal mechanical obstruction.
Theoretical analysis of laminar flow of power-law fluids in coiled tubing

A comprehensive theoretical study of the flow of power-law fluid in coiled tubing by using the boundary layer approximation method is presented. First, a boundary layer approximation analysis was applied to the governing equations of continuity and motion of a power law fluid in the curved tubing flow geometry. Momentum integral equations for the boundary layer flow were then derived and solved numerically. The resulting solutions of the velocity field were used to develop a new friction factor correlation in terms of generalized Dean number, coiled tubing curvature ratio, and flow behavior index of the power law fluid model. The new correlation of this study and a previous correlation by Mashelkar and Devarajan were evaluated using experimental data obtained from full-scale coiled tubing flow experiments. An excellent agreement was found between the new correlation and the experimental results. The Mashelkar and Devarajan correlation did not result in any acceptable agreement with the experimental data, nor did it match the Ito correlation for the limiting case of Newtonian fluids (n = 1). This work extends the range of applicability of the new correlation to fluids with flow behavior indices as low as 0.25, which would cover most fluids used for coiled tubing operations in the oil and gas industry as well as fluids used in other industries. © 2007 American Institute of Chemical Engineers AIChE J, 2007
Sliding clamp-DNA interactions are required for viability and contribute to DNA polymerase management in Escherichia coli.

Sliding clamp proteins topologically encircle DNA and play vital roles in coordinating the actions of various DNA replication, repair, and damage tolerance proteins. At least three distinct surfaces of the E. coli β clamp interact physically with the DNA that it topologically encircles. We utilized mutant β clamp proteins bearing G66E and G174A substitutions (β159), affecting the single strand (ss) DNA-binding region, or poly-Ala substitutions in place of residues 148-HQDVR-152 (β148–152), affecting the double strand (ds) DNA binding region, in order to determine the biological relevance of clamp-DNA interactions. As part of this work, we solved the x-ray crystal structure of β148–152, which verified that the poly-Ala substitutions failed to significantly alter the tertiary structure of the clamp. Based on functional assays, both β159 and β148–152 were impaired for loading and retention on a linear primed DNA in vitro. In the case of β148–152, this defect was not due to altered interactions with the DnaX clamp loader, but rather was the result of impaired β148–152-DNA interactions. Once loaded, β148–152 was proficient for Pol III replication in vitro. In contrast, β148–152 was severely impaired for Pol II and Pol IV replication, and was similarly impaired for direct physical interactions with these Pols. Despite its ability to support Pol III replication in vitro, β148–152 was unable to support viability of E. coli. Nevertheless, physiological levels of β148–152 expressed from a plasmid efficiently complemented the temperature sensitive growth phenotype of a strain expressing β159 (dnaN159), provided that Pol II and Pol IV were inactivated. Although this strain was impaired for Pol V-dependent mutagenesis, inactivation of Pol II and Pol IV restored the Pol V mutator phenotype. Taken together, these results support a model in which a sophisticated combination of competitive clamp-DNA, clamp-partner, and partner-DNA interactions serve to manage the actions of the different E. coli Pols in vivo.
ROVER: flexible yet consistent evolution of relationships

Abstract Relationships have been repeatedly identified as an important object-oriented modeling construct. Most emerging modeling standards such as the object database management group (ODMG) object model and UML have some support for relationships. However object-oriented database (OODB) systems have largely ignored the existence of relationships during schema evolution. We are the first to propose comprehensive support for relationship evolution. A complete schema evolution facility for any OODB system must provide primitives to manipulate all object model constructs, and maintenance strategies for the structural and referential integrity of the database under such evolution. We propose a set of basic evolution primitives for relationships as well as a compound set of changes that can be applied to the same. However, given the myriad of possible change semantics a user may desire in the future, any pre-defined set is not sufficient. Rather we present a flexible schema evolution framework that allows the user to define new relationship transformations as well as to extend existing ones. Addressing the second problem, namely of updating schema evolution primitives to conform to the new set of invariants, can be a very expensive re-engineering effort. In this paper we present an approach that de-couples the constraints from the schema evolution code, thereby enabling their update without any re-coding effort. We also present an approach that can be used to verify the correctness of these complex evolution operations using the de-coupled constraints.
E.M.F. measurements on the nickel-nickel(II) couple in molten fluorides

Summary E.m.f. measurements on the concentration cells Ni/Ni(II) ( a 1 =constant) ‖ BN sheath ‖ Ni(II) ( a 2 )|Ni in molten LiF−NaF−KF (42.0−11.5−46.5 mole%) and LiF−BeF 2 −ZrF 4 (65.6−29.4−5.0 mole%) at ∼500° result in linear plots of e.m.f. vs . log X 2 (the mole fraction of Ni(II) in the bulk of the melt), and the slopes predicted from the Nernst equation. The measured e.m.f. values are stable. The Ni/Ni(II) couple, contained in a boron nitride sheath, is a useful reference electrode for fluoride melts.
Deformation correlation effects in the 154Sm−144Sm neutron density difference

Abstract The second order Kerman, McManus and Thaler optical potential model is used in the analysis of 800 MeV proton elastic scattering data from 144,154 Sm. Correlation terms arising from the large intrinsic deformation of 154 Sm are included and are found to be quite significant. Neutron isotopic density distribution and rms radius differences are determined and are seen to be in good agreement with deformed basis, Hartree-Fock predictions.
Adaptive fusion model for distributed detection system

There has been a growing interest in developing efficient and reliable distributed detection systems for target recognition and communications. Chair and Varshney have derived an optimal decision rule for fusing decisions based on the Bayesian criterion. To implement the rule, the probability of detection PD and the probability of false alarm PF for each detector must be known, but this information is not always available in practice. This paper presents an adaptive fusion model which estimate the PD and PF adaptively during the decision fusing process. The estimation is implemented by a simple statistical method. That is, the estimates for PD and PF of the ith detector are obtained by counting the number of its decisions that are considered to be correct and incorrect, respectively. Since reference signals are not given, whether the decision of a local detector is considered correct or incorrect is arbitrated by the fused decision of all the other local detectors; that is, the fused decision of all other local detectors is used as the reference for the ith detector. Furthermore, in the work, the fused results of the other local decisions are classified as 'reliable' and 'unreliable'. Only reliable decisions are used to develop the decision rule. Analysis on classifying the fused decisions in terms of reducing estimation error is given, and simulation results which conform to our analysis are presented.© (1992) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Geospatial IT for mobile field data collection

Federal statistical agencies generate critical data about the nation's population, economy, and natural resources. This data is gathered largely by mobile field data collection. Although geospatial information is an essential reference material in the field and serves as a base for recording spatially linked data, it is nearly always used in printed form due to limitations in mobile computing systems and tools for handling geospatial data. The ability to interact with digital geospatial data in the field offers significant enhancements for data quality and operational efficiencies. However, basic research is needed on extensible infrastructure designs for limited field computing environments and appropriate field tools for mobile data gatherers.
The effects of temperature and photoperiod on activity in the red squirrel,Tamiasciurus hudsonicus ∗

Abstract Wheel‐running activity of ten red squirrels,Tamiasciurus hudsonicus, was monitored to determine how temperature and light‐dark cycles affect (1) the number of days required for entrainment; and (2) the phasing, amount and form of wheel‐running activity. The squirrels were individually housed at either a constant temperature of 20 ± 4°C or a temperature cycle of 6.5 ± 2 to 35 ± 2°C. A 12: 12 (207: 0 lx) light‐dark cycle was supplied by an incandescent bulb. The application of the temperature cycle had no apparent effect on the entrainment process proper. However, the phasing of activity onset was delayed by about 42 minutes, wheel running became less intense, and the activity pattern became divided into two components, with little wheel running when temperatures reached or exceeded 30°C.
An Interdisciplinary Theory of Behavior.

This paper combines biological, biochemical and psychological data toward the construction of a bio-psychological theory of behavior. The fundamental assumptions are that the environment favored the evolution of organisms possessing receptors sensitive to periodic or repetitive stimuli. Moreover the presence of periodic stimuli in space and time have induced, through natural selection, the appearance of highly advanced forms of living organisms capable of exploiting the environment by utilizing information in periodic stimuli. Indeed, this dependency on periodic stimulation, such as light energy and movement of surrounding matter, has induced a psychological, perceptual bias to readily assimilate repetitive stimuli thereby producing changes in behavior. This perceptual bias favored by organic evolution and reinforced by stimulation of the organism during development produces communication patterns in higher animals characterized by repetitive sounds. The relationship of this theory to current learning models is discussed and applications are made to human learning.
On Krull domains

One aim of this article is to provide for Krull domains a star-operation analogue of the following result: An integral domain D is a Dedekind domain if and only if each nonzero ideal A of D is strongly two generated. A nonzero ideal A of an integral domain D is called strongly two generated if for each x e A\{0} there is y e A such that A = xD + yD. Lantz and Martin show in [17] that a strongly two generated ideal is invertible. Following this lead we define a strongly *-type 2 ideal, for a star-operation *, as a nonzero ideal A such that for each x e A\{0}, there is y ~ A* such that (x, y)* = A*. Then in Section I we characterize Krult domains in terms of strongly *-type 2 ideals. Recently there has been considerable activity [1, 7, 12, 26] (some of it inspired by an earlier preprint version of the present paper) in characterizing a Krult domain in terms of the ,-invertibility of some or all fractional ideals of D. These results are interesting in that they indicate that most of the characterizations of Dedekind domains have *-oper- ation analogues for Krull domains. In Section 2 we continue this line of investigation by coordinating some of the recent results with some new characterizations of Krull domains in terms of *-invertibility.
Techniques to Improve MWIR Light Emitting Diode Emission Power

This paper presents some techniques to increase mid-wave mid-infrared (MWIR) light emitting diode (LED) light emission in the 3-4.5 mum wavelength regions using the Inter-band cascade structure. MWIR LEDs show practical applications in infrared scene generation, infrared counter measures, spectroscopic chemical and biological monitoring, medical diagnostics, and gas sensors.
Structural characterization of CalO1: a putative orsellinic acid methyltransferase in the calicheamicin-biosynthetic pathway.

The X-ray structure determination at 2.4 A resolution of the putative orsellinic acid C3 O-methyltransferase (CalO1) involved in calicheamicin biosynthesis is reported. Comparison of CalO1 with a homology model of the functionally related calicheamicin orsellinic acid C2 O-methyltransferase (CalO6) implicates several residues that are likely to contribute to the regiospecificity of alkylation. Consistent with the proposed requirement of an acyl-carrier-protein-bound substrate, this structural study also reveals structural determinants within CalO1 that are anticipated to accommodate an association with an acyl carrier protein.