Collection and transfusion of blood and blood components in the United States, 1989

A poor response to L-DOPA in addition to parkinsonian, cerebellar, and autonomic signs is commonly regarded as indicative of clinical multiple system atrophy (MSA). We compared the motor response to a single oral administration of 250 mg L-DOPA/25 mg carbidopa in eight MSA patients and eight Parkinson's disease (PD) patients with the "on-off" phenomenon, evaluating L-DOPA peripheral pharmacokinetics. Motor response was consistently good in all PD patients, but only four MSA patients had a (moderate) response. Pharmacokinetic parameters did not differ between the groups. The varying extent of putaminal damage could be responsible for the differing motor response to L-DOPA in MSA patients.     

Pitfalls in quantitative contrast echocardiography: the steps to quantitation of perfusion

Current methods used clinically to assess myocardial perfusion are invasive and expensive. As the technology of ultrasound imaging improves, CE may provide a relatively inexpensive, noninvasive means of quantitating myocardial perfusion. Issues regarding stability of microbubble contrast agents must be studied more closely under physiologic conditions. As such, encapsulated microbubbles may provide more stability under physiologic pressures than free gas microbubbles. Introducing high concentrations of contrast, either by hyperconcentrating the contrast agent or by increasing the injection rate, may provide greater stability under physiologic conditions. Further, before quantitative statement of tissue perfusion can be made, the relationship between tracer concentration and system response must be established. Further, a "linear" postprocessing ultrasound setting does not eliminate this requirement as data must still undergo nonlinear transformation during log compression and time-gain compensation. Additionally, issues regarding "electronic thresholding" must be explored more extensively in vivo. Commercial ultrasound scanners, in their present form, may not offer adequate sensitivity for absolute quantitative studies. Further development of modified ultrasound systems may provide sufficient sensitivity for quantitative perfusion imaging. CE offers a potentially powerful tool in the clinical management of patients with ischemic heart disease. Conventional coronary angiography provides information on the size of a lesion, but accompanying tissue perfusion distal to the lesion cannot be determined. Doppler ultrasonography determines velocity of blood flow in large vessels but does not offer the potential to quantitate tissue perfusion. Clearly, CE has a place in the future of diagnostic imaging. The recent work of Ito et al. demonstrated the qualitative potential of CE in the identification of "areas at risk" in patients who had undergone thrombolysis or percutaneous transluminal coronary angioplasty after an acute myocardial infarction. With further improvement in the ultrasound imaging techniques and microbubble stability, CE may offer an inexpensive, noninvasive means of assessing myocardial perfusion.     

In vitro growth and drug sensitivity of tumor colony-forming units from human tumor xenografts

To investigate the feasibility of using tissue obtained from human tumor xenografts for in vitro screening of antineoplastic agents, we grew human tumor colony-forming units (CFU) in semisold agar from xenografts serially passaged in nude mice. Growth of human tumor CFU was accomplished from nine xenografts representing five different histological tumor types (ovarian carcinoma, adenocarcinoma of the colon, malignant melanoma, epidermoid carcinoma of the lung, and malignant astrocytoma). Cloning efficiency ranged from 0.04 to 0.1% and showed significant variability both between tumor types and between individual animals bearing the same type of xenograft. A high percentage of tumor CFU was in S phase [47 +/- 20% (S.D.)] as determined by the thymidine "suicide" technique. The number of tumor CFU observed increased linearly with increasing numbers of cells plated. In vitro drug sensitivity of the tumor CFU was assessed to Adriamycin, cis-platinum, and melphalan. The patterns of drug sensitivity were found to be reproducible and stable over a period of 9 months. Drug sensitivity curves to Adriamycin for five xenografts representing four tumor types showed complex patterns with plateau portions similar to those described for tumor CFU from primary tumors. The rank order of sensitivity of the tumors was compared to that of normal granulocyte-macrophage progenitors and, with the exception of the melanomas, was found to correlate well with clinical experience (order of sensitivity = colon less than ovary less than bone marrow). Growth of human tumor CFU from xenografts represents a reproducible and stable means for the study of the biology of tumor CFU and has potential applications as a means for screening new anticancer agents.     

Energy-efficient induction motors performance characteristics andlife-cycle cost comparisons for centrifugal loads

When fixed-speed motors (fed directly at power frequency) are purchased for new installations or for replacements, the loaded shaft speed differences among motor options are either ignored or overestimated. The most common first-cut estimate is that the consumed shaft power will vary as the cube of the ratio of the motor rated nameplate speeds for centrifugal driven loads that have discharge control valves (on pressure or now control). In actuality, this is true only if the motors are loaded at approximately nameplate output. This paper discusses the true “control valve loss” factor taking into account actual speed differences among motor options. A simplified equation and figure are presented to permit quick evaluation of motor purchase alternatives for the lowest life-cycle cost based on efficiency and rated-load speed differences. NEMA standards on slip-speed variation should be made more stringent to increase the validity of speed-difference loss evaluations. Additionally, efficiency test results and loaded speed measurements for standard-efficiency and premium-efficiency 10 and 100 hp motors are presented, leading to a conclusion that standard-efficiency motors should be operated at no higher than rated voltage and that premium-efficiency motors should he operated at 5%-10% above rated voltage for best system efficiency     

Modeled and measured instruction fetching performance forsuperscalar microprocessors

Instruction fetching is critical to the performance of a superscalar microprocessor. We develop a mathematical model for three different cache techniques and evaluate its performance both in theory and in simulation using the SPEC95 suite of benchmarks. In all the techniques, the fetching performance is dramatically lower than ideal expectations. To help remedy the situation, we also evaluate its performance using prefetching. Nevertheless, fetching performance is fundamentally limited by control transfers. To solve this problem, we introduce a new fetching mechanism called a dual branch target buffer. The dual branch target buffer enables fetching performance to leap beyond the limitation imposed by conventional methods and achieve a high instruction fetching rate     

Agile workforce evaluation: a framework for cross-training and coordination

This paper outlines approaches for assessing and classifying manufacturing and service operations in terms of their suitability for use of cross-trained (flexible) workers. We refer to our overall framework as agile workforce evaluation. The primary contributions of this paper are: (i) a strategic assessment framework that structures the key mechanisms by which cross-training can support organizational strategy; (ii) a tactical framework that identifies key factors to guide the selection of an architecture and worker coordination policy for implementing workforce agility; (iii) a classification of workforce agility architectures; (iv) a survey of a broad range of archetypical classes of worker coordination policies; (v) a survey of the literature with an operational perspective on workforce agility; and (vi) identification of opportunities for research and development of architectures for specific production environments.     

Low temperature UV/ozone oxidation formation of HfSiON gate dielectric

Physical and electrical properties of hafnium silicon oxynitride (HfSi_xO_yN_z) dielectric films prepared by UV ozone oxidation of hafnium silicon nitride (HfSiN) followed by annealing to 450 °C are reported. Interfacial layer growth was minimized through room temperature deposition and subsequent ultraviolet/ozone oxidation. The capacitance–voltage (C–V) and current–voltage (I–V) characteristics of the as-deposited and annealed HfSi_xO_yN_z are presented. These 4 nm thick films have a dielectric constant of 8–9 with 12 at.% Hf composition, with a leakage current density of 3×10⁻⁵ A/cm² at V_fb+1 V. The films have a breakdown field strength >10 MV/cm.     

Localized Heat Therapy Improves Mitochondrial Respiratory Capacity but Not Fatty Acid Oxidation

AIM: Mild heat stress can improve mitochondrial respiratory capacity in skeletal muscle. However, long-term heat interventions are scarce, and the effects of heat therapy need to be understood in the context of the adaptations which follow the more complex combination of stimuli from exercise training. The purpose of this work was to compare the effects of 6 weeks of localized heat therapy on human skeletal muscle mitochondria to single-leg interval training. METHODS: Thirty-five subjects were assigned to receive sham therapy, short-wave diathermy heat therapy, or single-leg interval exercise training, localized to the quadriceps muscles of the right leg. All interventions took place 3 times per week. Muscle biopsies were performed at baseline, and after 3 and 6 weeks of intervention. Mitochondrial respiratory capacity was assessed on permeabilized muscle fibers via high-resolution respirometry. RESULTS: The primary finding of this work was that heat therapy and exercise training significantly improved mitochondrial respiratory capacity by 24.8 ± 6.2% and 27.9 ± 8.7%, respectively (p < 0.05). Fatty acid oxidation and citrate synthase activity were also increased following exercise training by 29.5 ± 6.8% and 19.0 ± 7.4%, respectively (p < 0.05). However, contrary to our hypothesis, heat therapy did not increase fatty acid oxidation or citrate synthase activity. CONCLUSION: Six weeks of muscle-localized heat therapy significantly improves mitochondrial respiratory capacity, comparable to exercise training. However, unlike exercise, heat does not improve fatty acid oxidation capacity.     

Seasonal variations in total fatty acid composition of muscles and eye sockets of tucunaré (Cichla sp.) from the Brazilian Amazon area

Seasonal variations in total fatty acid compositions of tucunaré, Cichla sp. in the Janauacá Lake of the Amazon basin were determined by GC. Saturated fatty acids (SFAs) were found to be at higher concentrations than monounsaturated fatty acids (MUFAs) and polyunsaturated fatty acids (PUFAs) in two seasonal periods. Major fatty acids were palmitic (16:0, 48.5–51.6% of total SFA), oleic (18:1ω9, 43.9–50.2% of total MUFA), docosahexaenoic (DHA, 22:6ω3, 13.5–27.9% of total PUFA) and arachidonic acid (AA, 20:4ω6, 16.0–19.6% of total PUFA). Polyunsaturated fatty acids were the most abundant in muscle during the flood period, and more especially fatty acids 22:6ω3 (10%) and 20:4ω6 (7%). There were no significant variations amongst total lipid SFA, MUFA, and PUFA from eye sockets. The ω6 fatty acid percentages were always higher than the ω3 fatty acid percentages in tucunaré, with ω6/ω3 ratios varying between 1.02 and 1.6 in the flood and drought periods.     

Eliminating Synaptic Ribbons from Rods and Cones Halves the Releasable Vesicle Pool and Slows Down Replenishment

Glutamate release from rod and cone photoreceptor cells involves presynaptic ribbons composed largely of the protein RIBEYE. To examine roles of ribbons in rods and cones, we studied mice in which GCamP3 replaced the B-domain of RIBEYE. We discovered that ribbons were absent from rods and cones of both knock-in mice possessing GCamP3 and conditional RIBEYE knockout mice. The mice lacking ribbons showed reduced temporal resolution and contrast sensitivity assessed with optomotor reflexes. ERG recordings showed 50% reduction in scotopic and photopic b-waves. The readily releasable pool (RRP) of vesicles in rods and cones measured using glutamate transporter anion currents (I_A(glu)) was also halved. We also studied the release from cones by stimulating them optogenetically with ChannelRhodopsin2 (ChR2) while recording postsynaptic currents in horizontal cells. Recovery of the release from paired pulse depression was twofold slower in the rods and cones lacking ribbons. The release from rods at −40 mV in darkness involves regularly spaced multivesicular fusion events. While the regular pattern of release remained in the rods lacking ribbons, the number of vesicles comprising each multivesicular event was halved. Our results support conclusions that synaptic ribbons in rods and cones expand the RRP, speed up vesicle replenishment, and augment some forms of multivesicular release. Slower replenishment and a smaller RRP in photoreceptors lacking ribbons may contribute to diminished temporal frequency responses and weaker contrast sensitivity.