Seminar planning guidelines. As I see it

Small local chapter groups can present quality cost effective regional seminars. Key components are dedication of members, teamwork, and a sense of direction. The following guidelines and information can provide a framework for planning and coordinating a seminar.     

A species of Plasmodium from sandhill cranes in Florida

Infections of a species of Plasmodium (subgenus Giovannolaia) were diagnosed in 3 sandhill cranes (Grus canadensis) from north-central Florida. This parasite is close morphometrically to Plasmodium polare; this finding constitutes the first report of a species of Plasmodium from sandhill cranes in North America.     

Free Radical Chemistry. Part 9.1 Approaches to Fluorinated Polyethers—Model Compound Studies

Using peroxide, γ-, and UV-irradiation, free radical addition reactions of hexafluoropropene to diethers and to 18-crown-6 have been investigated and mono-, di-, and poly-adducts have been obtained. Factors influencing these additions, especially polar characteristics of intermediate radicals, have been elucidated. Adducts of 18-crown-6 retain a capacity to complex to alkali-metal ions.     

The HMG-CoA reductase inhibitor atorvastatin increases the fractional clearance rate of postprandial triglyceride-rich lipoproteins in miniature pigs

We have previously shown in vivo that the 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor atorvastatin decreases hepatic apolipoprotein B (apoB) secretion into plasma. To test the hypothesis that atorvastatin modulates exogenous triglyceride-rich lipoprotein (TRL) metabolism in vivo, an oral fat load (2 g fat/kg body wt) containing retinol (50 000 IU) was given to 6 control miniature pigs and to 6 animals after 28 days of treatment with atorvastatin 3 mg. kg-1. d-1. A multicompartmental model was developed by use of SAAM II and kinetic analysis performed on the plasma retinyl palmitate (RP) data. Peak TRL (d<1.006 g/mL; Sf>20) triglyceride concentrations were decreased 29% by atorvastatin, and the time to achieve this peak was delayed (5.2 versus 2.3 hours; P<0.01). The TRL triglyceride 0- to 12-hour area under the curve was decreased by 24%. In contrast, atorvastatin treatment had no effect on peak TRL RP concentrations, time to peak, or its rate of appearance into plasma; however, the TRL RP 0- to 12-hour area under the curve was decreased by 20%. Analysis of the RP kinetic parameters revealed that the TRL fractional clearance rate was increased significantly, 1.4-fold (3.093 versus 2.276 pools/h; P=0.012), with atorvastatin treatment. The percent conversion of TRL RP from the rapid-turnover to the slow-turnover compartment was decreased by 47% with atorvastatin treatment. The TRL RP fractional clearance rate was negatively correlated with very low density lipoprotein apoB production rate measured in the fasting state (r=-0.49). Thus, although atorvastatin had no effect on intestinal TRL assembly and secretion, plasma TRL clearance was significantly increased, an effect that may relate to a decreased competition for removal processes by hepatic very low density lipoprotein.     

Dogs infected with a human granulocytotropic Ehrlichia spp. (Rickettsiales: Ehrlichieae)

In contrast to the anticipation that in sepsis granulocyte colony-stimulating factor (G-CSF) would overactivate the nonspecific immune system by recruiting and priming leukocytes with consequent aggravation of inflammatory tissue lesions, recombinant (r) G-CSF pretreatment was protective in various experimental non-neutropenic models of inflammation. The mechanisms of protection, however, are not fully understood. Using intravital fluorescence microscopy, we show that rG-CSF enhances leukocyte endothelial cell interaction within the microvasculature of normal rat livers, whereas rG-CSF pretreatment of animals exposed to lipopolysaccharide (LPS) attenuates the LPS-induced leukocytic response, including stasis in sinusoids as well as rolling and adherence in postsinusoidal venules with subsequent tissue infiltration. Moreover, rG-CSF, which did not affect Kupffer cell activity in normal rat livers, reduced the immediate activation of Kupffer cells on LPS exposure, as indicated in vivo by the delayed adherence/phagocytosis of intra-arterially administered latex particles associated with attenuation of proinflammatory cytokine release (tumor necrosis factor alpha and interleukin-6). Finally, rG-CSF reduced LPS-induced nutritive perfusion failure and hepatocellular excretory dysfunction. This study provides evidence for a distinct, possibly tumor necrosis factor alpha-dependent modulation of LPS-induced cellular response within the liver by rG-CSF, thereby achieving protection against microcirculatory perfusion failure and hepatic dysfunction.     

Molecular analysis of the histone gene cluster of Psammechinus miliaris: III. Polarity and asymmetry of the histone-coding sequences

The Ca2+ antagonistic coronary vasodilator, Nifedipine, was sublingually administered by a dose of 30 mg to 19 patients with hypertension. Blood pressure of patients with with essential hypertension (n=14) decreased from 177 +/- 24 to 123 +/- 13 mmHg systolic and from 108 +/- 12 to 80 +/- 11 mmHg diastolic (mean +/- SD) (p less than 0.01). Plasma renin activity (PRA) increased significantly from 0.73 +/- 0.62 to 1.50 +/- 1.02 ng/ml/h (p less than 0.05). The same tendency was observed in malignant and renovascular hypertension. In primary aldosteronism (n = 2), blood pressure decreased but PRA did not increase. Hypotensive action and increased plasma renin activity by Ca2+ antagonist, Nifedipine, were clearly demonstrated in patients with hypertension.     

Layered Antiferromagnetism Induces Large Negative Magnetoresistance in the van der Waals Semiconductor CrSBr

The recent discovery of magnetism within the family of exfoliatable van der Waals (vdW) compounds has attracted considerable interest in these materials for both fundamental research and technological applications. However, current vdW magnets are limited by their extreme sensitivity to air, low ordering temperatures, and poor charge transport properties. Here the magnetic and electronic properties of CrSBr are reported, an air-stable vdW antiferromagnetic semiconductor that readily cleaves perpendicular to the stacking axis. Below its Néel temperature, T_N = 132 ± 1 K, CrSBr adopts an A-type antiferromagnetic structure with each individual layer ferromagnetically ordered internally and the layers coupled antiferromagnetically along the stacking direction. Scanning tunneling spectroscopy and photoluminescence (PL) reveal that the electronic gap is Δ_E = 1.5 ± 0.2 eV with a corresponding PL peak centered at 1.25 ± 0.07 eV. Using magnetotransport measurements, strong coupling between magnetic order and transport properties in CrSBr is demonstrated, leading to a large negative magnetoresistance response that is unique among vdW materials. These findings establish CrSBr as a promising material platform for increasing the applicability of vdW magnets to the field of spin-based electronics.     

Estimation of induction machine inverse rotor time constant using torque angle tangent calculation

A new inverse rotor time constant estimation scheme for an induction machine is presented. For high performance induction machine control, indirect rotor flux oriented vector control is the most commonly applied control technique. It requires that an accurate estimate of the inverse rotor time constant is obtained to ensure correct orientation of the current vector with the rotor flux vector. An incorrect estimate will result in an incorrect flux level, reduced dynamic torque performance and reduced maximum available torque. A novel parameter estimation scheme is presented, based on the calculation of the tangent of the torque angle. The effectiveness of the technique is demonstrated through simulation and practical results.     

Iron status and diet in athletes

Plasma ferritin (F) concentrations were measured (range 12-245 ng.ml-1) as an indicator of iron status in 24 male and 45 female healthy, nonanemic athletes. Usual food intake was assessed using a self-completed but supervised food frequency questionnaire. Linear regression was applied to determine the relationship between log F (as data was skewed) and average daily intake of iron (Fe), meat (M), protein (Pr), carbohydrate (CHO), fat (Fa), fiber (Fi), and kilojoules (Kj). There were negative correlations between F and each of Kj (P < 0.01) and CHO (P < 0.001), and a positive correlation between F and Pr/Kj (P < 0.01). No significant relationship existed between F and any of Fe, M, Fa, or Fi. These data suggest that iron or meat intake may not be important determinants of iron status in these athletes. Instead, the percentage of protein in the diet may be more influential on F, as may the (negative) effect of Kj and CHO intake, or at least their reflection of energy expenditure.