New options in directed cupration: Studies in heteroleptic bis(amido)cuprate formation Dedicated to the memory of Jack Lewis.

The 2:1 combination of MPLi (MP = 2-methylpiperidide) with CuBr gives the novel complex [(MP)2CuLi(THF)2]2LiBr 12 and introduces the chiral ligand MP to the evolving field of Directed ortho Cupration reagents. Subsequent syntheses have focused on developing heteroleptic bis(amido) arrangements at Cu, with 1:1 mixtures of two out of MPLi, DMPLi and TMPLi (DMP = 2,6-cis-dimethylpiperidide; TMP = 2,2,6,6-tetramethylpiperidide) being reacted with CuI salts in the presence of THF. Resulting lithiocuprates reveal solid state dimers based on the heteroleptic bis(amido) formulations R2N(TMP)Cu(Br)Li2(THF)2 (R2N = MP 13; R2N = DMP 14). The heteroleptic Gilman lithiocuprate PIP(TMP)CuLi (PIP = piperidide) 15 has also been prepared. In each of 12–15, significant variations in the orientations of the amide ligands can be rationalized in terms of steric effects and, in the case of 15, stabilization of the alkali metal by Me…Li interaction is evidenced.This work was supported by the U.K. EPSRC through grant EP/J500380/1 (A P.)

Reactions of Trimethylaluminium: Modelling the Chemical Degradation of Synthetic Lubricants

In investigating and seeking to mimic the reactivity of trimethylaluminium (TMA) with synthetic, ester-based lubricating oils, the reaction of methyl propionate $\textbf{1}$ was explored with 1, 2 and 3 equivalents of the organoaluminium reagent. Spectroscopic analysis points to the formation of the adduct $\textbf{1}$ (TMA) accompanied only by the low level 1:1 production of Me$_{2}$AlOCEtMe$_{2}$ $\textbf{2}$ and Me$_{2}$AlOMe $\textbf{3}$ when an equimolar amount of TMA is applied. The deployment of excess TMA favours reaction to give $\textbf{2}$ and $\textbf{3}$ over $\textbf{1}$(TMA) adduct formation and spectroscopy reveals that in hydrocarbon solution substitution product $\textbf{2}$ traps unreacted TMA to yield $\textbf{2}$(TMA). The $^{1}$H NMR spectroscopic observation of two Al-Me signals not attributable to free TMA and in the ratio 1:4 suggests the formation of a previously only postulated, symmetrical metallacycle in Me$_{4}$Al$_{2}$ (μ$^{2}$-Me)(μ$^{2}$-OCEtMe$_{2}$ ). In the presence of $\textbf{3}$, $\textbf{2}$(TMA) undergoes thermally induced exchange to yield Me$_{4}$Al$_{2}$(μ$^{2}$-OMe)(μ$^{2}$-OCEtMe$_{2}$) $\textbf{4}$ and TMA. The reaction of methyl phenylacetate $\textbf{5}$ with TMA allows isolation of the crystalline product Me$_{2}$AlOCBnMe$_{2}$ (TMA) $\textbf{6}$(TMA), which allows the first observation of the Me$_{}$ Al$_{2}$(μ$^{2}$-Me)(μ$^{2}$-OR) motif in the solid state. Distances of 2.133(3) Å (Al-Me$_{bridging}$) and 1.951 Å (mean Al-Me$_{terminal}$) are recorded. The abstraction of TMA from $\textbf{6}$(TMA) by the introduction of Et$_{2}$O has yielded $\textbf{6}$, which exists as a dimer.This work was supported by Cambridge Refrigeration Technology (J.S.). The U.K. EPSRC are acknowledged for grant EP/J500380/1 (A.J.P.)

Search for Exotic Strange Quark Matter in High Energy Nuclear Reactions

We report on a search for metastable positively and negatively charged states of strange quark matter in Au+Pb reactions at 11.6 A GeV/c in experiment E864. We have sampled approximately six billion 10% most central Au+Pb interactions and have observed no strangelet states (baryon number A < 100 droplets of strange quark matter). We thus set upper limits on the production of these exotic states at the level of 1-6 x 10^{-8} per central collision. These limits are the best and most model independent for this colliding system. We discuss the implications of our results on strangelet production mechanisms, and also on the stability question of strange quark matter.Comment: 21 pages, 9 figures, to be published in Nuclear Physics A (Carl Dover memorial edition

The doctrine of the 'responsibility to protect' as a practice of political exceptionalism

The consensus on the doctrine of the ‘responsibility to protect’ has replaced ideas of humanitarian intervention with a new vision of the responsibilities that states have to protect their peoples from the most egregious suffering. The contention of this article is that this is a politics of exceptionalism, whereby power is legitimated by reference to its effectiveness in responding to emergency or crisis. By analysing the doctrine in this way, new light is shed on the debate surrounding the responsibility to protect. First, understanding the doctrine in terms of exceptionalism helps explain the paradox of how the doctrine has been assimilated so readily into institutional and state practice without manifesting any greater commitment to international intervention. Second, understanding these new security practices in terms of exceptionalism allows us to move beyond questions of imperialism. Once understood in terms of exceptionalism, it can be shown that the stakes in the debate on the responsibility to protect are restricted not only to relations between states, but also to relations within them: principles of representative government are to be substituted with paternalist and authoritarian visions of state power

Effect of local cold-pack application on systemic anabolic and inflammatory response to sprint-interval training: a prospective comparative trial

We evaluated the effect of cold ice-pack application following a brief sprint-interval training on the balance between anabolic mediators [growth hormone (GH), insulin-like growth factor-I (IGF-I), testosterone], catabolic markers (cortisol, IGFBP-1), and circulating pro [Interlukin-6 (IL-6) and IL-1β]- and anti-inflammatory cytokines [IL-1 receptor antagonist (IL-1ra)]. Twelve males, elite junior handball players performed 4 × 250 m treadmill run, at 80% of each individual’s maximal speed, followed by a rest period with and without local cold-pack application. Pre, immediately post, and 60-min post-exercise blood samples were drawn. Exercise was associated with a significant increase in IL-6, GH, IGFBP-3, and testosterone levels. Local cold-pack application was associated with significant decreases in IL-1β, IL-1ra, IGF-I, and IGFBP-3 and a greater increase of IGFBP-1 during recovery. Local ice therapy immediately following sprint-interval training was associated with greater decreases in both pro- and anti-inflammatory cytokines and anabolic hormones supporting some clinical evidence for possible negative effects on athletic performance

Positive nasal culture of methicillin-resistant Staphylococcus aureus (MRSA) is a risk factor for surgical site infection in orthopedics

Background Although nasal carriage of MRSA has been identified as one of the risk factors for surgical site infection (SSI) with MRSA, there have been no reports of this in the orthopedics field

Measurement of the B0 anti-B0 oscillation frequency using l- D*+ pairs and lepton flavor tags

The oscillation frequency Delta-md of B0 anti-B0 mixing is measured using the partially reconstructed semileptonic decay anti-B0 -> l- nubar D*+ X. The data sample was collected with the CDF detector at the Fermilab Tevatron collider during 1992 - 1995 by triggering on the existence of two lepton candidates in an event, and corresponds to about 110 pb-1 of pbar p collisions at sqrt(s) = 1.8 TeV. We estimate the proper decay time of the anti-B0 meson from the measured decay length and reconstructed momentum of the l- D*+ system. The charge of the lepton in the final state identifies the flavor of the anti-B0 meson at its decay. The second lepton in the event is used to infer the flavor of the anti-B0 meson at production. We measure the oscillation frequency to be Delta-md = 0.516 +/- 0.099 +0.029 -0.035 ps-1, where the first uncertainty is statistical and the second is systematic.Comment: 30 pages, 7 figures. Submitted to Physical Review

Search for New Particles Decaying to top-antitop in proton-antiproton collisions at squareroot(s)=1.8 TeV

We use 106 \ipb of data collected with the Collider Detector at Fermilab to search for narrow-width, vector particles decaying to a top and an anti-top quark. Model independent upper limits on the cross section for narrow, vector resonances decaying to \ttbar are presented. At the 95% confidence level, we exclude the existence of a leptophobic \zpr boson in a model of topcolor-assisted technicolor with mass M_{\zpr} $<$ 480 \gev for natural width $\Gamma$ = 0.012 M_{\zpr}, and M_{\zpr} $<$ 780 \gev for $\Gamma$ = 0.04 M_{\zpr}.Comment: The CDF Collaboration, submitted to PRL 25-Feb-200

Double Diffraction Dissociation at the Fermilab Tevatron Collider

We present results from a measurement of double diffraction dissociation in $\bar pp$ collisions at the Fermilab Tevatron collider. The production cross section for events with a central pseudorapidity gap of width $\Delta\eta^0>3$ (overlapping $\eta=0$) is found to be $4.43\pm 0.02{(stat)}{\pm 1.18}{(syst) mb}$ [$3.42\pm 0.01{(stat)}{\pm 1.09}{(syst) mb}$] at $\sqrt{s}=1800$ [630] GeV. Our results are compared with previous measurements and with predictions based on Regge theory and factorization.Comment: 10 pages, 4 figures, using RevTeX. Submitted to Physical Review Letter