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Fermilab experiment 690 [1], a study of target dissociation reactions pp → pX using an 800 GeV/c proton beam and a liquid hydrogen target, collected data in late 1991. The incident beam and 600–800 GeV/c scattered protons were measured using a system of six 6 in. × 4 in. and two 15 in. × 8 in. pressurized drift chambers spaced over 260 m. These chambers provided precise measurements at rates above 10 MHz (2 MHz per cm of sense wire). The measurement resolution of the smaller chambers was 90 μm, and the resolution of the larger chambers was 125 μm. Construction details and performance results, including radiation damage, are presented.

We have measured the momentum correlation of pion pairs produced in the collisions of 27.5 GeV/c protons in liquid hydrogen. By considering events for which all final state particles have been measured, we have succeeded in reducing backgrounds due to particle misidentification below 5% for ${\ensuremath{\pi}}^{+}$ and 1% for ${\ensuremath{\pi}}^{\ensuremath{-}}$. Our use of a precision magnetic spectrometer has provided an accurate determination of particle momenta and excellent acceptance for particle pairs with small relative momentum essential for correlations studies. A large data sample of fully reconstructed events (1 \ifmmode\times\else\texttimes\fi{} ${10}^{6}$) allows us to analyze the correlations for ${\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{+}$ and ${\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\pi}}^{\ensuremath{-}}$ pairs separately, and also as a function of the final state multiplicity. We find that the pion pair correlations scale 0.98 fm describes the data well. We do not find any indication of multiplicity dependence of the correlation scale for multiplicities from 6 to 14 final state particles.

The Fermilab Main Injector Project will provide 120-150-GeV proton and antiproton beams for Fermilab Fixed Target Physics and Colliding Beams Physics use. A dipole magnet has been designed and prototypes constructed for the principal bending magnets of this new accelerator. The design considerations and fabrication techniques are described. Measurement results on prototypes are reported, emphasizing the field uniformity achieved in both body field and end field at excitation levels from injection at 0.1 T to full field of 1.7 T. >

Fermilab has considered several possible directions for upgrading the performance of the existing Tevatron complex so as to effectively double the mass range accessible to experiment. Alternatives examined include luminosity and/or energy enhancements and the possibility of providing proton-proton collisions. New construction required and performance parameters for the preferred option are discussed. The primary differences between the new and existing superconducting accelerators are the energy, the increased field strengths required, and the increased phase advance per cell and matched dispersion which lower eta /sub max/ from 5.8 m in the existing machine to 2.5 m in the new machine. The dominant design issue is the superconducting bending magnet to be used in the new Tevatron. >

Fermilab has embarked upon a program, Fermilab III, to raise the luminosity in the Tevatron proton-antiproton collider over a five-year period by at least a factor of 30 beyond the currently achieved level of 1.6*10/sup 30/ cm/sup -2/ s/sup -1/. Components of the program include implementation of electrostatic separators, antiproton source improvements, installation of cold compressors, doubling the existing linac output energy, and the construction of a new accelerator, the Fermilab Main Injector. Basic limitations in the achievement of higher luminosity in the Tevatron, the strategy developed to achieve the Fermilab III goals, and the evolution of luminosity throughout the period are discussed. >

The Main Injector project at Fermilab requires a dipole with good field quality from 0.1 T to 1.73 T with ramps to full field at up to 2.4 T/s over an aperture of 10 cm*5 cm. Operation of this magnet for the variety of purposes proposed for the Main Injector results in a design with low inductance, large copper cross section, and field uniformity sufficient for high-intensity injection and efficient slow resonant extraction. The resulting design is presented, along with measurement results of a prototype magnet emphasizing the field uniformity. >

OBJECTIVES: Open-heart surgery with fibrillatory arrest has been reported to be associated with an increased risk of stroke. We examined whether minimally invasive mitral valve surgery with fibrillatory arrest conferred a higher risk of stroke/transient ischaemic attack (TIA) and other major complications compared with median sternotomy and cardioplegic arrest. METHODS: Data were collected prospectively for 387 patients who had mitral valve surgery; 239 had a minimally invasive surgical approach and 148 had median sternotomy. All minimally invasive surgeries were performed by surgeons who were experienced in minimally invasive techniques. The effect of operative approach on risk of stroke/TIA and major morbidity was examined. After propensity score matching (PSM) was conducted between the two groups, 76 patients remained in each group. RESULTS: Before matching, the incidence of stroke/TIA did not differ between patients who had minimally invasive surgery (0.5%, n =1 ) and those who had median sternotomy (1.4%, n =2 ;P= 0.56). Patients who had minimally invasive surgery had a lower incidence of other major morbidity (0.8%, n= 2) than patients who had median sternotomy (6.1%, n =9 ;P= 0.004). After adjustment for age and Society of Thoracic Surgeons predicted risk, there was no effect of operative approach on the odds for stroke/TIA (odds ratio [OR] = 0.41, P= 0.49) or other major morbidity (OR = 0.40, P= 0.31). After PSM, patients were balanced on preoperative characteristics. No patient in either matched group experienced permanent stroke/TIA, and major morbidity did not differ between the two groups (minimally invasive, 1.3%, n= 1; median sternotomy, 1.3%, n =1 ;P> 0.99). CONCLUSIONS: A minimally invasive approach for mitral valve surgery on a fibrillating heart was not associated with a greater incidence of stroke/TIA than was median sternotomy. When performed by highly experienced surgeons, the minimally invasive approach with fibrillatory arrest did not increase the risk of perioperative stroke.

Fermilab is in the midst of a program to raise the luminosity in the Tevatron proton-antiproton collider by at least a factor of five above the currently achieved level of 1.6/spl times/10/sup 31/ cm/sup -2/ sec/sup -1/. Components of this program include the construction of a new synchrotron, the Main Injector, a new antiproton storage ring, the recycler, and a variety of improvements to the existing antiproton source and Tevatron. Commissioning of these components will be underway in early 1999 with the next Tevatron collider run scheduled to start in April 2000. Initial commissioning experience with these systems will be described, along with developments underway to support further Tevatron luminosity enhancements over the coming decade.

The effects of the thiazolidinedione insulin sensitiser BRL 49653 on plasma leptin concentrations and on epididymal fat OB, PPAR-gamma and aP2 mRNA expression were examined in high-fat-fed and high-carbohydrate-fed adult Wistar rats. Diets were given for 4 weeks, with BRL 49653 (10 micromol/kg/day) administered by oral gavage for the last 4 days. Treatment with BRL 49653 reduced plasma leptin concentrations in high-fat-fed rats from 2.34 +/- 0.19 (n=9) to 1.42 +/- 0.09 (n=9) ng/ml (p0.001). Plasma leptin was unaffected by BRL 49653 in the high-carbohydrate-fed rats. There was no difference in OB mRNA expression between high-fat-fed and high-carbohydrate-fed rats, with or without treatment. PPAR-gamma and aP2 mRNA expression were significantly increased in the high-fat-fed rats treated with BRL 49653 (p0.01 and p0.001 respectively), but not in carbohydrate-fed rats.

A novel technique for both online and offline computation is presented. With this technique, a reconstruction analysis in elementary particle physics, otherwise prohibitively long, has been accomplished. It will be used online in an upcoming Fermilab experiment to reconstruct more than 100000 events per second and to trigger on the basis of that information. The technique delivers 40 gigaoperations per second, has a bandwidth on the order of gigabytes per second, and has a modest cost. An overview of the program, details of the system, and performance measurements are presented. >

We report measurements of the electroproduction of phi mesons from hydrogen at Q/sup 2/ values of 0.23, 0.43, and 0.97 GeV/sup 2/ with t varying from 0.125 to 1.3 GeV/sup 2/ at each Q/sup 2/ point. The data show no evidence for a Q/sup 2/ dependence of the slope of the t distribution; the forward cross section falls with increasing Q/sup 2/ as the square of the phi propagator; the decay angular distributions agree with the predictions of s-channel helicity conservation; and the ratio of the longitudinal to the transverse component increases linearly with Q/sup 2/.

We report measurements of kaon electroproduction from hydrogen and deuterium targets carried out at the Wilson Synchrotron Laboratory at Cornell University. The reactions ..gamma../sub V/p ..-->.. K/sup +/X/sup 0/, K/sup +/..lambda.., and K/sup +/..sigma../sup 0/ were studied in the kinematic region 2.15 .. 0 as Q/sup 2/ increases.

We report measurements of the electroproduction of phi mesons from hydrogen at Q/sup 2/ values of 0.23, 0.43, and 0.97 GeV/sup 2/ with vertical-bartvertical-bar varying from 0.125 to 1.3 GeV/sup 2/ at each Q/sup 2/ point. The data show no evidence for a Q/sup 2/ dependence of the slope of the t distribution, the forward cross section falls with increasing Q/sup 2/ as the square of the phi propagator, the decay angular distributions agree with the predictions of s-channel helicity conservation, and the ratio of the longitudinal to the transverse component increases linearly with Q/sup 2/.

Measurements are reported of the ratio of positively charged to negatively charged pions electroproduced at 0degree and 90degree in the virtual photon-nucleon center-of-mass system. The ..pi../sup +//..pi../sup -/ ratio is studied as a function of W, Q/sup 2/, ..omega.., x/sub T/, and x in the range 2.1 GeV< or =W< or =3.2 GeV and 1.2 GeV/sup 2/< or =Q/sup 2/< or =9.5 GeV/sup 2/. (AIP)

Measurements of the electroproduction reaction ${e}^{\ensuremath{-}}+p\ensuremath{\rightarrow}{e}^{\ensuremath{-}}+{\ensuremath{\pi}}^{+}+n$ carried out at the Wilson Synchrotron Laboratory are reported. For fixed virtual photon-hadron center-of-mass energy, $W=2.67$ GeV, data are presented with the mass of the virtual photon, $\ensuremath{-}{k}^{2}$, centered at 0.6, 1.2, and 2.0 Ge${\mathrm{V}}^{2}$. At the central $\ensuremath{-}{k}^{2}=1.2$ ${(\mathrm{GeV})}^{2}$ point, results are also given for $W=2.15$ GeV. For the $W=2.67$, $\ensuremath{-}{k}^{2}=1.2$ Ge${\mathrm{V}}^{2}$ setting, an angular scan is presented and the longitudinal transverse-interference term is extracted. The data are compared with an electron Born-model calculation of Berends which has as its only free parameter the pion electromagnetic form factor. The theory is used to extract new results for the pion form factor up to $\ensuremath{-}{k}^{2}=2.0$ Ge${\mathrm{V}}^{2}$.

We report measurements of the exclusive electroproduction reaction $e+p\ensuremath{\rightarrow}e+{\ensuremath{\pi}}^{+}+n$ for pions produced near 0\ifmmode^\circ\else\textdegree\fi{} in the virtual-photon-proton center-of-mass system with values of $\ensuremath{\epsilon}$ in the range $0.35l\ensuremath{\epsilon}l0.45$. Combination with data taken at $\ensuremath{\epsilon}$ near 1 allows us to separate the contributions from transversely polarized and scalar photons in the range $1.2 {\mathrm{GeV}}^{2}l{Q}^{2}l3.3 {\mathrm{GeV}}^{2}$.

We report measurements of the inclusive electroproduction reaction e + p ..-->.. e + ..lambda.. + anything for ..lambda..'s produced along and near the direction of the virtual photon. The measurements cover the kinematic range 2.1 < W < 3.55 GeV, 0.1 < Q/sup 2/ < 1.5 GeV/sup 2/, 0 < p/sub T//sup ts2/

We report measurements of semi-inclusive pion electroproduction from both hydrogen and deuterium targets carried out at the Wilson Synchrotron Laboratory at Cornell University. Measurements were made at the (W,Q/sup 2/) points (2.15 GeV, 1.2 GeV/sup 2/), (2.15, 4.0), and (3.11, 1.2) with hydrogen and deuterium, and at (2.15, 2.0), (2.67, 3.3), and (3.11, 1.7) with hydrogen only. The invariant virtual-photoproduction cross section for pions scaled by the total cross section is studied as a function of x', P/sub T/ /sup 2/, W, and Q/sup 2/. The invariant structure function shows no Q/sup 2/ dependence and a weak W dependence. The ratio of ..pi../sup +/ to ..pi../sup -/ production is also presented, but a distinction between a universal ..omega.. or W dependence cannot be made.

We report measurements of the inclusive electroproduction reaction ep..-->..e..pi../sup +/X for pions produced at 90degree in the virtual-photon-proton center-of-mass system. Data are presented at the (W,Q/sup 2/) points (2.2 GeV, 1.2 GeV/sup 2/), (2.2, 3.6), (2.65, 1.2), (2.65, 2.0), (2.65, 2.8), (2.65, 3.6), (3.1, 1.2), and (3.1, 2.0). The invariant structure function is studied as a function of W, Q/sup 2/, x/sub T/, p/sub T//sup 2/, and the square of the invariant undetected mass. (AIP)

We discuss methods of designing electron storage rings in such a manner as to produce longitudinally polarized electrons at the interaction point while minimizing depolarization effects. As an example, we present a 10 GeV electron storage ring capable of providing longitudinally polarized electrons for electron-proton collisions in which stochastic depolarization is eliminated (in the absence of machine imperfections). The resultant polarization level of 83% is limited solely by reverse bending.

New measurements of the electroproduction of single charged pions hydrogen and deuterium targets carried out at the Wilson Synchrotron at Cornell University are reported. Measurements were made at the (W, Q$sup 2$) points (2.15 GeV, 1.2 GeV$sup 2$), (2.15, 4.0), and (3.11, 1.2) with hydrogen and deuterium and at (2.15, 2.0), (2.67, 3.4), and (3.11, 1.7) with only hydrogen. The deuterium data were used to determine the ratio of the cross sections for the reactions $gamma$/subV/d $Yields$ $pi$$sup +$nn/subs/ and $gamma$/subV/d $Yields$ $pi$$sup -$pp/subs/ and thus to measure the isoscalar contribution to the reaction $gamma$/subV/p $Yields$ $pi$$sup +$n. The data are consistent with the hypothesis that this ratio is a universal function of the momentum transfer. The measured ratio was used to determine from the hydrogen data and the data taken in earlier experiments the isovector component of the cross section. The dispersion theory formulated by Berends was then used to determine from the isovector component the pion form factor in the Q$sup 2$ range from 0.2 to 4.0 GeV$sup 2$. A simple pole expression of the form 1 + Q$sup 2$/(0.471 +- 0.010)$sup -1$ gives a good fit to the data. (AIP)

At a concentration of 1×10−4M (28.84 Μg/ml), with a solvent concentration of 1.0% (v/v) ethanol, the deacetylated (amine) metabolite of diamphenethide (DAMD) causes an initial stimulation of activity, followed by suppression, leading to a paralysis within 3 h. These changes are accompanied by an increase in muscle tone of more than 200 mg. However, ethanol alone at a concentration of 1.0% (v/v) causes an initial stimulation of activity and increase in muscle tone (approximately 550 mg). If the concentration of DAMD is kept at 1×10−4M (28.84 Μg/ml) but the solvent concentration reduced [e.g., 0.05% (v/ v) dimethyl sulphoxide], then only a suppression of motility and flaccid paralysis are observed. This response is also seen at the lower concentration of 10 Μg/ml, which corresponds to the maximum blood levels of DAMD in vivo. The sodium ionophore monensin induces a suppression of motility, leading to a rapid flaccid paralysis (in approximately 1.5 h at 1×10−7M, and within a few minutes at higher concentrations). Ouabain, an inhibitor of Na+/K+-ATPase activity, also causes a suppression of motility, but this is accompanied by an increase in muscle tone, leading to a spastic paralysis (in approximately 2.5 h at 1×10−3M, and 3.5 h at 1×10−4M). Pretreatment with ouabain (1×10−3M for 15 min) followed by monensin (1×10−5M) reverses the original effect of monensin by inducing a rapid spastic paralysis (in approximately 50 min). A similar effect is observed with DAMD (10 Μg/ml) following ouabain pretreatment; a spastic paralysis is reached after approximately 80 min. The results are discussed in relation to the postulated activity of DAMD as a sodium ionophore, Na+/K+-ATPase inhibitor, or neuromuscular depressant.

The effects of a wide range of fasciolicides on the in vitro motility of Fasciola hepatica have been determined by means of an isometric transducer system. Carbon tetrachloride and diamphenethide do not affect movement at concentrations up to 500 and 100 micrograms/ml, respectively; at 1000 micrograms/ml, however, carbon tetrachloride induces a rapid tonic paralysis. Brotianide and the deacetylated metabolite of diamphenethide cause a rapid flaccid paralysis of the fluke at concentrations of 1.0 micrograms/ml and above. In contrast, the effect of MK-401 is a long-term one, a flaccid paralysis occurring after 20 hr only at 200 micrograms/ml. Praziquantel also produces a flaccid paralysis of the fluke, but this follows an initial increase, then decrease in muscle tone. The effect is rapid at 500 micrograms/ml, but long-term at 100 and 200 micrograms/ml; at these lower concentrations there is also a stimulation of activity. Oxyclozanide , rafoxanide, niclofolan , bithionol, and hexacholorophene induce a rapid spastic paralysis of the fluke at concentrations of 1.0 micrograms/ml and above. Both phasic and tonic components are evident in the response at concentrations of 1.0 micrograms/ml and below; the phasic component disappears at higher concentrations. Nitroxynil produces a similar effect, evident at higher concentrations. Among the benzimidazoles, mebendazole, oxfendazole, and albendazole sulphoxide cause a suppression of motility, whilst thiabendazole and albendazole produce a stimulation of movement. The effects are not rapid, however, for only mebendazole at 500 micrograms/ml causes total inactivity of the fluke within a 12-hr period. Possible explanations for these effects on fluke motility are discussed.

We report measurements of the electroproduction of single charged pions from hydrogen and deuterium targets for values of $\ensuremath{\epsilon}$ in the range $0.35l\ensuremath{\epsilon}l0.45$. Data were taken with a hydrogen target at the ($W, {Q}^{2}$) points (2.15 GeV, 1.2 ${\mathrm{GeV}}^{2}$), (2.65, 2.0), (2.65, 3.4), (2.65, 6.0), and (2.65, 10.0). Data were taken with a deuterium target at the ($W, {Q}^{2}$) points (2.15, 1.2) and (2.65, 2.0). The transverse cross section obtained by using these data in conjunction with earlier data at high $\ensuremath{\epsilon}$ to separate the longitudinal and transverse components is used in conjunction with the new data and the $t$-channel Born term to determine the pion form factor and to re-evaluate previously reported measurements. In the range $0.15 \mathrm{Ge}{\mathrm{V}}^{2}l{Q}^{2}l10.0 \mathrm{Ge}{\mathrm{V}}^{2}$ the pion form factor can be described by the simple pole form ${[1+\frac{{Q}^{2}}{(0.462\ifmmode\pm\else\textpm\fi{}0.024)}]}^{\ensuremath{-}1}$.

The effects of metabolic inhibitors on the in vitro motility of Fasciola hepatica have been determined by means of an isometric transducer system. Sodium fluoride, an inhibitor of glycolysis, causes a long-term suppression of motility; this is also the effect of sodium iodoacetate (another glycolysis inhibitor) at low concentrations (1 × 10 −5 M and below). However, higher concentrations of iodoacetate induce a rapid inhibition of activity leading to a spastic paralysis. Both rotenone and oligomycin, which act as inhibitors of oxidative phosphorylation, produce a long-term suppression of movement. Carbonylcyanide- p -trifluoromethoxyphenylhydrazone and carbonylcyanide- m -chlorophenylhydrazone, which are uncouplers of oxidative phosphorylation, induce a spastic paralysis of the fluke; this is rapid at high concentrations (1 × 10 −4 and 1 × 10 −5 M ). A brief stimulation of activity is evident at 1 × 10 −5 M and lasts longer at 1 × 10 −6 and 1 × 10 −7 M , before inhibition sets in. There is no stimulation at low concentrations of carbonyl cyanide- p -trifluoromethoxyphenylhydrazone (1 × 10 −8 and 1 × 10 −9 M ), only inhibition leading to a medium-term spastic paralysis. In contrast, a third uncoupler, 2,4-dinitrophenol, causes a flaccid paralysis and the effect is rapid only at high concentrations, being accompanied by an initial increase in muscle tone at 1 × 10 −2 M and a brief stimulation of motility at 1 × 10 −3 M . Stimulation lasts longer at 1 × 10 −4 and 1 × 10 −5 M , but is not evident at concentrations below this. The effects on motility at these lower concentrations are essentially long term in nature. That the rapid effects of the uncouplers on muscle tone and motility are not due primarily to uncoupling is shown by 2,4,6-trinitrophenol and hydroquinone, compounds structurally related to 2,4-dinitrophenol. 2,4,6-Trinitrophenol is a membrane-impermeable compound devoid of uncoupling activity; at 1 × 10 −3 M , it causes an immediate inhibition of activity and increase in muscle tone. The antioxidant hydroquinone produces an initial stimulation of motility with some increase in tone, but this is followed by a sharp decline and a short-term flaccid paralysis. The results are discussed in relation to the postulated effects of certain fasciolicides on the energy metabolism of the liver fluke.

This report studied the action of interferon on the thyroidal adenylate cyclase-cAMP system. It was found that human interferon did not increase cAMP levels in human or bovine thyroid slices during a 60-min incubation. Mouse interferon also had no effect on cAMP levels in mouse thyroidal lobes over the 60-min incubation, nor did it increase adenylate cyclase activity in mouse thyroid homogenates.