5,572 research outputs found
Production of the h_c and h_b and Implications for Quarkonium Spectroscopy
The recent observation of the h_c is an important test of QCD calculations
and provides constraints on models of quarkonium spectroscopy. In this
contribution I discuss some of these implications and describe methods to
search for the h_c and h_b via radiative transitions and other means.Comment: Talk presented at the 1st Meeting of the APS Topical Group on
Hadronic Physics (Fermilab, Oct 24-26, 2004), 4 pages, 1 figure, uses jpconf.
References adde
The Partial Visibility Representation Extension Problem
For a graph , a function is called a \emph{bar visibility
representation} of when for each vertex , is a
horizontal line segment (\emph{bar}) and iff there is an
unobstructed, vertical, -wide line of sight between and
. Graphs admitting such representations are well understood (via
simple characterizations) and recognizable in linear time. For a directed graph
, a bar visibility representation of , additionally, puts the bar
strictly below the bar for each directed edge of
. We study a generalization of the recognition problem where a function
defined on a subset of is given and the question is whether
there is a bar visibility representation of with for every . We show that for undirected graphs this problem
together with closely related problems are \NP-complete, but for certain cases
involving directed graphs it is solvable in polynomial time.Comment: Appears in the Proceedings of the 24th International Symposium on
Graph Drawing and Network Visualization (GD 2016
The gluonic condensate from the hyperfine splitting in charmonium
The precision measurement of the hyperfine splitting MeV in the
Fermilab--E835 experiment allows to determine the gluonic condensate with
high accuracy if the gluonic correlation length is fixed. In our
calculations the negative value of MeV is
obtained only if the relatively small fm and
GeV are taken. These values correspond to the ``physical'' string tension
GeV). For fm the hyperfine splitting
is positive and grows for increasing . In particular for fm
and GeV the splitting MeV
is obtained, which is in accord with the recent CLEO result.Comment: 9 pages revtex 4, no figure
Design and validation of a partial-genome microarray for transcriptional profiling of the Bradyrhizobium japonicum symbiotic gene region
The design and use of a pilot microarray for transcriptome analysis of the symbiotic, nitrogen-fixing Bradyrhizobium japonicum is reported here. The custom-synthesized chip (Affymetrix GeneChipÂź) features 738 genes, more than half of which belong to a 400-kb chromosomal segment strongly associated with symbiosis-related functions. RNA was isolated following an optimized protocol from wild-type cells grown aerobically and microaerobically, and from cells of aerobically grown regR mutant and microaerobically grown nifA mutant. Comparative microarray analyses thus revealed genes that are transcribed in either a RegR- or a NifA-dependent manner plus genes whose expression depends on the cellular oxygen status. Several genes were newly identified as members of the RegR and NifA regulons, beyond genes, which had been known from previous work. A comprehensive transcription analysis was performed with one of the new RegR-controlled genes (id880). Expression levels determined by microarray analysis of selected NifA- and RegR-controlled genes corresponded well with quantitative real-time PCR data, demonstrating the high complementarity of microarray analysis to classical methods of gene expression analysis in B. japonicum. Nevertheless, several previously established members of the NifA regulon were not detected as transcribed genes by microarray analysis, confirming the potential pitfalls of this approach also observed by other authors. By and large, this pilot study has paved the way towards the genome-wide transcriptome analysis of the 9.1-Mb B. japonicum genom
A Pilot Experiment to Replace Missing Rainfall Events Using Soil Moisture Information from the Kansas Mesonet
The Kansas Mesonet is a state-of-the-art environmental monitoring network that provides accurate rainfall measurements across Kansas. However, missing rainfall records are common problems in weather stations that rely on tipping bucket rain gauges. In this study, we conducted a pilot experiment to estimate missing rainfall records from root-zone soil moisture information recorded at Kansas Mesonet stations. Soil moisture is recorded at depths of 5, 10, 20, and 50 cm using the Campbell ScienÂtific CS655 soil water reflectometer. Hourly rainfall and soil moisture data from mid- August 2017 to mid-May 2018 were taken from three stations (Lakin, Manhattan, and Hays) of the Kansas Mesonet. Rainfall was estimated as the difference in soil moisture storage between 1 hour before and 1 hour after a given rainfall event. Preliminary results show that soil moisture-derived rainfall can be more accurate than using rainfall data from nearby stations. Soil moisture could serve as very useful information in quality control procedures to flag missing rainfall events
Evaluating Traditional and Modern Laboratory Techniques for Determining Permanent Wilting Point
The permanent wilting point is often considered the lower limit for plant available water and can be measured in the laboratory using a pressure plate apparatus (traditional method) or a dewpoint water potential meter (modern method). However, recent evidence suggests substantial discrepancy between the soil moisture at the permanent wilting points derived from these two laboratory techniques. This preliminary study investigated the magnitude of the discrepancy between permanent wilting points derived from traditional and modern laboratory techniques and the concomitant effects on plant available water estimations. For the analysis, a total of 21 undisturbed soil samples were collected from the top 20 inches of the soil profile at 18 locations of the Kansas Mesonet. The soil moisture content at the permanent wilting point measured using the pressure plate apparatus was 22% higher in clay loam soils and 25% higher in the clay soils than the soil moisture values obtained using a dewpoint water potential meter. When using the pressure plate apparatus, the resulting plant available water capacity (PAWC) was 33% lower in clay loam soils and 57% lower in clay soils compared to the PAWC estimated using the dewpoint water potential meter. Only minor discrepancies of about 8 to 9% were observed in both the resulting permanent wilting point and the estimated PAWC in the silt loam and sandy loam soils
On-Farm Assessment of AquaSpy Soil Moisture Sensors for Irrigation Scheduling
The aim of this study was to compare a commercially-available radio-frequency (RF) spectroscopy soil moisture sensor with an array of calibrated research-grade soil water reflectometers in a no-till irrigated corn field from June to September 2020. The RF probe consisted of 12 sensors spaced at 4-inch intervals across 48 inches in length, while the array of soil water reflectometers consisted of four sensors deployed along the soil profile at 4, 12, 20, and 28 in. depth. Soil moisture sensors were installed at approximately 30-ft apart in two different regions within the same field characterized by contrasting soil textural classes. Hourly soil moisture and soil temperature were collected by both sensors and compared across the study period. The RF probe closely followed the soil moisture dynamics captured by the research-grade sensors. Preliminary results reveal that the tested RF sensor is useful for irrigation scheduling based on relative soil moisture values. Field-specific calibrations are required to translate the relative soil moisture measurements of the RF sensor into soil water storage in terms of volumetric water content or inches of water in the soil profile
Robustly Safe Compilation
Secure compilers generate compiled code that withstands many target-level attacks such as alteration of control flow, data leaks or memory corruption. Many existing secure compilers are proven to be fully abstract, meaning that they reflect and preserve observational equivalence. Fully abstract compilation is strong and useful but, in certain cases, comes at the cost of requiring expensive runtime constructs in compiled code. These constructs may have no relevance for security, but are needed to accommodate differences between the source and target languages that fully abstract compilation necessarily needs
Cyclooxygenase-2 inhibitors. 1,5-diarylpyrrol-3-acetic esters with enhanced inhibitory activity toward cyclooxygenase-2 and improved cyclooxygenase-2/cyclooxygenase-1 selectivity.
he important role of cyclooxygenase-2 (COX-2) in the pathogenesis of inflammation and side effect limitations of current COX-2 inhibitor drugs illustrates a need for the design of new compounds based on alternative structural templates. We previously reported a set of substituted 1,5-diarylpyrrole derivatives, along with their inhibitory activity toward COX enzymes. Several compounds proved to be highly selective COX-2 inhibitors and their affinity data were rationalized through docking simulations. In this paper, we describe the synthesis of new 1,5-diarylpyrrole derivatives that were assayed for their in vitro inhibitory effects toward COX isozymes. Among them, the ethyl-2-methyl-5-[4-(methylsulfonyl)phenyl]-1-[3-fluorophenyl]-1H-pyrrol-3- acetate (1d), which was the most potent and COX-2 selective compound, also showed a very interesting in vivo anti-inflammatory and analgesic activity, laying the foundations for developing new lead compounds that could be effective agents in the armamentarium for the management of inflammation and pain
Pilot Scale Evaluation of Wild Saccharomyces cerevisiae Strains in Aglianico
In winemaking, the influence of Saccharomyces cerevisiae strains on the aromatic components of wine is well recognized on a laboratory scale, but few studies deal with the comparison of numerous strains on a pilot scale fermentation. In this scenario, the present work aimed to validate the fermentative behavior of seven wild S. cerevisiae strains on pilot-scale fermentations to evaluate their impact on the aromatic profiles of the resulting wines. The strains, isolated from grapes of different Italian regional varieties, were tested in pilot-scale fermentation trials performed in the cellar in 1 hL of Aglianico grape must. Then, wines were analyzed for their microbiological cell loads, main chemical parameters of enological interest (ethanol, total sugars, fructose, glucose, total and volatile acidity, malic and lactic acids) and volatile aroma profiles by GC/MS/SPME. Seventy-six volatile compounds belonging to six different classes (esters, alcohols, terpenes, aldehydes, acids, and ketones) were identified. The seven strains showed different trends and significant differences, and for each class of compounds, high-producing and low-producing strains were found. Since the present work was performed at a pilot-scale level, mimicking as much as possible real working conditions, the results obtained can be considered as a validation of the screened S. cerevisiae strains and a strategy to discriminate in real closed conditions strains able to impart desired wine sensory features
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