Comparing Wilson and Clover Quenched SU(3)SU(3) Spectroscopy with an Improved Gauge Action

We present results of quenched $SU(3)$ hadron spectroscopy comparing \order(a) improved Wilson (Clover) fermions with conventional Wilson fermions. The configurations were generated using an \order(a^2) improved 6-link $SU(3)$ pure gauge action at $\beta$'s corresponding to lattice spacings of $0.15$, $0.18$, $0.20$, $0.33$, and $0.43$ fm. We find evidence that fermionic scaling violations are consistent with \order(a^2) for Clover and \order(a) with a nonnegligible \order(a^2) term for standard Wilson fermions. This latter mixed ansatz makes a reliable continuum extrapolation problematic for Wilson fermions. We also find that the slope of the scaling violations is roughly $250 MeV$ for both Wilson and Clover fermions.Comment: 3 pages latex with 2 postscript figures. Talk presented at LATTICE96(spectrum

Quenched SU(3)SU(3) hadron spectroscopy using improved fermionic and gauge actions

We present results of quenched $SU(3)$ hadron spectroscopy using \order(a) improved Wilson fermions. The configurations were generated using an \order(a^2) improved 6-link $SU(3)$ pure gauge action at $\beta$'s corresponding to lattice spacings of $0.43$, $0.25$, $0.20$, $0.18$, and $0.15$ fm. We find evidence that fermionic scaling violations are consistent with \order(a^2) errors.Comment: 4 pages latex with 3 postscript figures. Corrected column heading in tabl

Methodology for sampling and analysis of lipids in aerosols from the remote marine atmosphere

A procedure is described for the collection of remote marine aerosol samples by high-volume filtration, cascade impaction, dry fallout collection and rain. Samples were analyzed quantitatively for five classes of naturally occurring lipids (n-alkanes, wax esters, fatty alcohols, sterols, and fatty acids) and polycyclic aromatic hydrocarbons (PAHs). Air samples (4,000-10,000 m3) were collected on glass fiber filters under automatic control. Rain samples of 1-5 L were collected on an event basis. Filters and rain samples were extracted with methylene chloride. The extracts were fractionated into discrete chemical classes by silca-gel absorption chromatography. The fractions were derivatized if necessary and analyzed by HRGC and HRGC/MS. A second fiter extraction was required for fatty acid salt analysis. Internal standards were used to quantify recoveries and concentrations. Mean recoveries relative to the internal standards were 96.5% for C12-C36 n-alkanes, 96.4% for C12-C30 n-fatty acids, 92.5% for C12-C30 n-fatty alcohols and 93.3% for cholesterol. Typical blanks and concentrations for remote marine aerosol and rain samples are described and compared with other methods used in coastal marine, rural and suburban sampling locations.Prepared for the National Science Foundation under Grants OCE 77-12914 and OCE 81-11947 as part of the Sea-Air Exchange (SEAREX) Program

SCRI Results With the Tadpole-Improved Clover Action

We compare light hadron spectroscopy using the Wilson and Clover fermionic actions. We show that a Clover coefficient chosen using tadpole-improved tree-level perturbation theory effectively eliminates the O(a) discretization errors present in the Wilson action. We find that discretization errors in light spectroscopy for both the Wilson and Clover actions are characterized by an energy scale mu of about 200-300 MeV, indicating that these errors can be reduced to the 5% level by using the Clover action at an inverse lattice spacing of about 1.3 GeV.Comment: Talk presented at the International Workshop on Lattice QCD On Parallel Computers, University of Tsukuba, March 10-15 1997. 9 LaTex pages plus 6 postscript figures, uses espcrc2.st

A Fluorogenic Red Fluorescent Protein Heterodimer

SummaryThe expanding repertoire of genetically encoded biosensors constructed from variants of Aequorea victoria green fluorescent protein (GFP) enable the imaging of a variety of intracellular biochemical processes. To facilitate the imaging of multiple biosensors in a single cell, we undertook the development of a dimerization-dependent red fluorescent protein (ddRFP) that provides an alternative strategy for biosensor construction. An extensive process of rational engineering and directed protein evolution led to the discovery of a ddRFP with a Kd of 33 μM and a 10-fold increase in fluorescence upon heterodimer formation. We demonstrate that the dimerization-dependent fluorescence of ddRFP can be used for detection of a protein-protein interaction in vitro, imaging of the reversible Ca2+-dependent association of calmodulin and M13 in live cells, and imaging of caspase-3 activity during apoptosis

Diquarks and Exotic Spectroscopy

We propose that the recently discovered \Theta baryon is a bound state of four quarks and an antiquark, containing two highly correlated ud-pairs. If so, the \Theta baryon has positive parity, and it lies in an near-ideally mixed SU(3)_{f} \mathbf{\bar{10}}_{f} oplus \mathbf{8}_{f}. The Roper resonance and the P_{11}(1710) fit naturally into this classification. We predict an isospin 3/2 multiplet of \Xi's (S=-2) with J^{\Pi}=\half^{+} around 1750 MeV. A search for manifestly exotic \Xi^{+} and \Xi^{--} in this mass range could provide a sharp test of our proposal. We predict that charm and bottom analogues of the \Theta baryon are stable against strong decays.Comment: 5 pages, 2 figures, revtex 4, minor corrections and revisions for journal publicatio

Conjugated Linoleic Acid Supplementation Does Not Reduce Visceral Adipose Tissue in Middle-Aged Men Engaged in a Resistance-Training Program

Conjugated linoleic acid (CLA) supplementation has shown convincing effects at reducing body fat in animals; yet human study results have been somewhat inconclusive. The purpose of this study is to determine whether four weeks of CLA supplementation, the approximate length of a commercial package, can result in a positive change in visceral adipose tissue in resistance-trained middle-aged men. Thirty overweight and moderately obese, but otherwise healthy male subjects (aged 35 to 55 years) currently involved in resistance training, were randomly assigned into CLA and placebo groups in a double-blind, placebo controlled approach. The study lasted for 12 weeks and consisted of three four-week periods. During the first four weeks (run-in period) each subject received placebo (4 g safflower oil). Throughout the next four weeks (supplementation period), the placebo group continued receiving placebo, while the CLA group received 3.2 g/d of CLA. During the final four weeks (run-out period) all subjects received the placebo. Computed tomography (CT) scans were used to measure visceral adipose tissue (VAT) at weeks 4, 8 and 12. No significant reduction in VAT cross-sectional area was determined in the CLA group during the study. On the contrary, a significant reduction in cross-sectional area of VAT of 23.12 cm2 during the supplementation period was measured in the placebo group, which was abated during the run-out period. Our results suggest that CLA supplementation of 3.2 g/d for four weeks does not promote decreases in VAT in middle-aged men currently participating in a resistance-training program

The Human Dimension of Pollution Policy Implementation: Air Quality in Rural China

The People's Republic of China is experiencing severe air pollution with very serious public health and economic consequences. Over the past decade, the Chinese government has sought to utilize bureaucratic, political, legal and educational vehicles to address these problems. This paper examines the ways in which those policy measures have been communicated to, understood by, and acted upon by the citizenry, drawing in important part on household and epidemiological surveys conducted in Anhui. Our study suggests that the central government's message has yet to be absorbed to the degree intended and then considers both why this has been the case and how the effectiveness of policy mechanisms might be enhanced

Impact of Required Versus Optional Remake of a Preparation on Pharmacy Students’ Compounding Accuracy

Objective. This retrospective study investigated the impact of a required vs an optional remake requirement on student performance in a compounding laboratory course in which students’ compounded preparations were analyzed

alpha-Sarcin catalytic activity is not required for cytotoxicity

<p>Abstract</p> <p>Background</p> <p>α-Sarcin is a protein toxin produced by <it>Aspergillus giganteus</it>. It belongs to a family of cytotoxic ribonucleases that inactivate the ribosome and inhibit protein synthesis. α-Sarcin cleaves a single phosphodiester bond within the RNA backbone of the large ribosomal subunit, which makes the ribosome unrecognizable to elongation factors and, in turn, blocks protein synthesis. Although it is widely held that the protein synthesis inhibition caused by the toxin leads to cell death, it has not been directly shown that catalytically inactive mutants of α-sarcin are non-toxic when expressed directly within the cytoplasm of cells. This is important since recent studies have cast doubt on whether protein synthesis inhibition is sufficient to initiate apoptosis.</p> <p>Results</p> <p>In this report, we assay α-sarcin cytotoxicity and ability to inhibit protein synthesis by direct cytoplasmic expression. We show that mutations in α-sarcin, which impair α-sarcin's ability to inhibit protein synthesis, do not affect its cytotoxicity. The mutants are unable to activate JNK, confirming that the sarcin-ricin loop remains intact and that the α-sarcin mutants are catalytically inactive. In addition, both mutant and wildtype variants of α-sarcin localize to the nucleus and cytoplasm, where they co-localize with ribosomal marker RPS6.</p> <p>Conclusion</p> <p>We conclude that although protein synthesis inhibition likely contributes to cell death, it is not required. Thus, our results suggest that α-sarcin can promote cell death through a previously unappreciated mechanism that is independent of rRNA cleavage and JNK activation.</p