cssi/SciSciGPT-SciSciNet huggingface dataset:
New correlations for predicting the effect of deposition on collection efficiency and pressure drop in granular filtration

Abstract Experiments on granular filtration of gas-solid suspensions were conducted to determine the changes in particle collection efficiency and pressure drop necessary to maintain a given gas flow rate as a filter becomes clogged with deposited particles. Based on the data obtained, together with similar data collected previously [Takahashi, T., Walata, S. A. and Tien, C. (1986) AIChE J. 32, 684–690], empirical correlations were established relating the increase in collection efficiency and pressure gradient with the extent of deposition and other relevant variables. Examples demonstrating the use of these correlations in predicting the transient behavior of granular filtration are presented.
Prior Endoscopy in Patients with Newly Diagnosed Celiac Disease; A Missed Opportunity?

Background Celiac disease (CD) is under-diagnosed in the United States, and factors related to the performance of endoscopy may be contributory.
Adaptive gridding for finite difference solutions to heat and mass transfer problems

Abstract : The authors' purpose in writing this paper is to review some of their recent work in the calculation of optimal meshes for the solution of parabolic and elliptic partial differential equations (PDE). They first explain our strategies for the adaptive placement of mesh points. In addition, they make some speculation as to promising avenues for future research in mesh adaptation. Finally, they discuss examples of the application of adaptive gridding to problems of heat and mass transfer. They draw these examples from our work in combustion modeling. In obtaining numerical solutions of PDEs, the spatial derivatives are often approximated by discrete representations on a mesh network. The accuracy of any numerical solution depends in an important way on the relationship of the location of the mesh points to changes in the dependent variables. The authors objective is to investigate finite difference methods in which the mesh networks adapt themselves dynamically to obtain accurate solutions. Such methods represent an important advance in overcoming a major shortcoming of traditional fixed mesh methods which are often unable to resolve accurately steep fronts or sharp peaks.
tRNA genes as chromatin barriers.

Chromatin barriers restrict silenced chromatin domains from invading active domains. A recent study shows that a tRNA gene functions as a barrier in Schizosaccharomyces pombe. These results, similar to previous observations in Saccharomyces cerevisiae, point toward a novel function for tRNA genes and a common mechanism of compartmentalizing and organizing eukaryotic chromatin.
Effect of microwaves on the migration of lithium and silicon from lithium disilicate (Li2O-2SiO2) glass

Lithium disilicate (Li2O-2SiO2) glass was immersed in a static solution of deionized water and heated by a microwave or by conventional means for various times. The resulting Li+ and Si migration was compared by solution analysis and the corroded glass surfaces were compared by Fourier transform infrared reflection spectroscopy and scanning electron microscopy. Results show no substantial differences in migration or glass corrosion under the test conditions using 7.00 GHz microwave radiation, but leave open the possibility of very slightly altered kinetics using 5.86 GHz radiation. More testing at 2.45 GHz is suggested.
On the Structure of Syndiotactic Poly(propylenes)

Abstract Propylene was polymerized with the catalyst system (C2H5)2A1C1/ VCk/ anisole at -78°C using various conditions. The resulting polymers were successively extracted by diethyl ether, hexane, and heptane, leaving the residue. The polymers of the four series were characterized by intrinsic viscosity, gel permeation chromatography, 13C nuclear magnetic resonance, infrared spectroscopy, x-ray diffraction, and by differential scanning calorimetry. The combined evidence from the various methods indicates that this catalyst system leads to stereoblock polymers which can be fractionated according to stereochemical composition and sequence length.
The influence of professional development on changes in educators’ facilitation of complex thinking in preschool classrooms

Over a three-year period, 20 educators, who worked at a preschool in Hawaii serving two- to five-year-old children, participated in professional development designed to promote complex thinking among young learners. Six times each year, the educators were video-recorded while teaching to assess their use of strategies that facilitate complex thinking. Results indicated that across time, the professional development promoted teachers’ use of strategies to promote children's complex thinking increased, and the trajectories of all teachers’ strategy use increased at similar growth rates. Teachers who worked with younger children used the strategies to a lesser degree. Consistent with previous research on effective professional development, findings suggest the positive influences of professional development that goes beyond the ‘one shot’ workshop to promote the practice of new strategies, feedback, and reflection.
Are HMOs bad for health maintenance

This study examines the impact of Health Maintenance Organization (HMO) coverage on the provision of preventive medicine. We investigate whether any association reflects selection effects on the part of patients and/or physicians or a causal impact of managed care itself. Causal effects may occur on the supply side or the demand side. Using a large national database of Medicare and non-Medicare patients, we investigate these issues for eight common preventive medical procedures. We find that preventive care is substantially higher with HMO coverage than with traditional fee-for-service reimbursement. Our findings also suggest that the impact of HMOs on preventive medicine is a causal one, and does not merely reflect selection effects. Both supply-side (e.g. provider) and demand-side (e.g. patient) factors appear to play a role in the higher incidence of preventive care among HMO enrollees. Patient demand effects are stronger for simple treatments such as physicals, while supply-side effects seem to dominate for relatively complex preventive care procedures such as mammograms.
Cardiac SPECT accurately predict coronary artery disease in a minority female population

Abstract Background: Single photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) is a well-established method for evaluation and risk stratification of coronary artery disease. However, there is limited data that validates SPECT imaging in minority female patients. Methods: The database of our cardiovascular nuclear imaging laboratory and cardiac catheterization laboratory (Bronx-Lebanon Hospital Center) was retrospectively queried for African-American and Hispanic female patients who had MPI from January 1999 to June 2001 and also had cardiac catheterization done within 90 days. Patients with recent coronary artery bypass grafting and percutaneous coronary intervention were excluded. All patients had rest/stress single day protocol with gated SPECT imaging. We also reviewed public web site of social security death index (SSDI) on February 2004 for all of these patients. Results: Of the 54 female patients who had MPI stress testing, 7 had exercise, 26 had adenosine, 18 had dipyridamole and 3 had dobutamine. Out of 45 patients, who had positive MPI, 34 patients had CAD confirmed by coronary angiography. Positive predictive value was 76% (60–87% CI 95%). Out of 9 patients, who had low risk MPI, 4 patients had normal coronaries. Eighteen patients (53%) had the same number of vessels predicted by MPI and coronary angiography (7 with 3-vessel disease, 7 with 2-vessel disease and 4 with 1-vessel disease). The predictive value for left anterior descending artery was 80%, circumflex was 83% and for the right coronary artery was 85%. 5 of 54 patients were found dead on review of SSDI. Three patients who died had intermediate and 2 had high risk scans. Conclusion: This study assesses the positive predictive value of MPI in female African-American and Hispanic patients. The value of performing MPI in this population was similar with what has been reported in non-minority male populations. Similarly, patients with low risk study had good prognosis.
Telomerase reactivation reverses tissue degeneration in aged telomerase-deficient mice

An ageing world population has fuelled interest in regenerative remedies that may stem declining organ function and maintain fitness. Unanswered is whether elimination of intrinsic instigators driving age-associated degeneration can reverse, as opposed to simply arrest, various afflictions of the aged. Such instigators include progressively damaged genomes. Telomerase-deficient mice have served as a model system to study the adverse cellular and organismal consequences of wide-spread endogenous DNA damage signalling activation in vivo 1 . Telomere loss and uncapping provokes progressive tissue atrophy, stem cell depletion, organ system failure and impaired tissue injury responses 1 . Here, we sought to determine whether entrenched multi-system degeneration in adult mice with severe telomere dysfunction can be halted or possibly reversed by reactivation of endogenous telomerase activity. To this end, we engineered a knock-in allele encoding a 4-hydroxytamoxifen (4-OHT)-inducible telomerase reverse transcriptase-oestrogen receptor (TERT-ER) under transcriptional control of the endogenous TERT promoter. Homozygous TERT-ER mice have short dysfunctional telomeres and sustain increased DNA damage signalling and classical degenerative phenotypes upon successive generational matings and advancing age. Telomerase reactivation in such late generation TERT-ER mice extends telomeres, reduces DNA damage signalling and associated cellular checkpoint responses, allows resumption of proliferation in quiescent cultures, and eliminates degenerative phenotypes across multiple organs including testes, spleens and intestines. Notably, somatic telomerase reactivation reversed neurodegeneration with restoration of proliferating Sox2 1 neural progenitors, Dcx 1 newborn neurons, and Olig2 1 oligodendrocyte populations. Consistent with the integral role of subventricular zone neural progenitors in generation and maintenance of olfactory bulb interneurons 2 ,t his wave of telomerase-dependent neurogenesis resulted in alleviation of hyposmia and recovery of innate olfactory avoidance responses. Accumulating evidence implicating telomere damage as a driver of age-associated organ decline and disease risk 1,3 and the marked reversal of systemic degenerative phenotypes in adult mice observed here support the development of regenerative strategies designed to restore telomere integrity. Accelerating structural and functional decline across diverse organ systems is observed in the aged 1,3,4 . The loss of genome integrity and associated DNA damage signalling and cellular checkpoint responses are well-established intrinsic instigators that drive tissue degeneration during ageing 5 . Of particular relevance to this study, age-progressive loss of telomere function in mice has been shown to provoke widespread p53 activation resulting in activation of cellular checkpoints of apoptosis, impaired proliferation and senescence, compromised tissue stem cell and progenitor function, marked tissue atrophy and physiological impairment in many organ systems 1,6 .
Evaluation of two procedures for monitoring populations of early season insect pests (Thysanoptera: Thripidae and Homoptera: Aphididae) in cotton under selected management strategies.

Plant washing and visual whole-plant search were evaluated for their effectiveness in monitoring populations of thrips (primarily tobacco thrips, Frankliniella fusca (Hinds)) and aphids, Aphis gossypii Glover, in seedling cotton, Gossypium hirsutum L. Comparisons were made within four early season pest management strategies consisting of 1) TSX, a mixture of terraclor and terrazole (control); 2) acephate-treated cotton seed without TSX; 3) acephate-treated cotton seed + TSX; and 4) aldicarb in furrow + TSX. These four pest management strategies established different levels of pest populations. In the control plots, immature thrips were detected approximately 1 wk earlier with plant washing than with visual whole-plant search. Significantly more immature thrips, aphids, and total pests were found with plant washing than with visual search. At peak infestation, 63% more immature thrips were observed using plant washing than were recorded using visual search. As recorded by plant washing, suppression of immatures by treatment was 78.9, 80.5, and 94.5% in the treated plots, respectively. Population estimates of adult thrips determined with the two procedures were not significantly different. As a pest complex on seedling cotton, a peak aphid infestation occurred 12 d after planting (DAP), adult thrips peaked 20 DAP and the highest number of immature thrips was recorded 28 DAP.
Gas permeability of various block copolyether—urethanes

Abstract The effect of chemical structure and fabrication variables on the gas permeability of several block copolyether—urethane—urea and copolyether—urethane membranes was determined. It was found that the gas permeability of the copolyether—urethane—ureas increased in a linear manner with an increase in the polypropylene glycol segment molecular weight. Copolymers with a polyethylene glycol segment were found to be less permeable than those with propylene glycol segments. This may be due to the ability of polyethylene glycol to crystallize. For both copolymer systems, the type of chain extender used affected gas permeability. Again, these effects may be due to the degree of phase separation and to the nature of chain packing with the different extenders (i.e., the better the packing the lower the permeability). Changes in casting solvent, or the addition of salts such as LiBr or urea, had only minor effects on gas permeability.
Ketonization of acetic acid on titania-functionalized silica monoliths

Titania-functionalized monolith catalysts operated at short contact times are highly selective for the formation of ketones from carboxylic acids. The selectivity of ketonization of acetic acid to form acetone over such catalysts varies little as the conversion is varied from 3 to 100%. These results demonstrate that ketonization is not a sequential reaction proceeding via a gaseous ketene product. The selectivity for ketene versus ketone formation is determined by the intrinsic chemistry of the catalyst, and cannot be manipulated by contact time or conversion variations.
Total and Partial Photoproduction Cross Sections at 1.44, 2.8, and 4.7 GeV

A nearly monochromatic high-energy photon beam produced by Compton backscattering of ruby laser light has been used to study photoproduction in a hydrogen bubble chamber. The total hadronic γp cross sections at 1.44, 2.8, and 4.7 GeV are found to be 145.1 ± 5.7, 131.3 ± 4.3, and 124.2 ± 3.9 μb, respectively. Partial cross sections are presented also. © 1969 The American Physical Society.
Occurrence of apoAcyl carrier protein and an S-alkylation-resistant form of holoAcyl carrier protein in Escherichia coli.

Abstract The 4′-phosphopantetheine prosthetic group of holoacyl carrier protein (holoACP) in Escherichia coli turns over independently of the apoprotein, due to the activities of holoACP hydrolase and holoACP synthetase. There is no measurable pool of apoACP in pantothenate-supplemented cells of a pantothenate-requiring mutant, but extended incubation on deficient medium, with exhaustion of cellular coenzyme A (CoA), leads to slow accumulation of the apoprotein. It is concluded that, although the activities of the synthetase and hydrolase are about equal in crude extracts, in the cells an excess synthetase activity maintains ACP completely as holoACP unless cells are artifically depleted of CoA, the donor of the 4′-phosphopantetheine group. About 20% of the holoACP in normal cells was designated as “holoACP esters,” being resistant to S -alkylation unless first treated with neutral hydroxylamine; this proportion increased to about 80% in pantothenate starvation. A preliminary attempt to identify acyl portions from this material was unsuccessful. The proportion of this material was not elevated in other strains under conditions which show feedback inhibition of fatty acid biosynthesis in vivo .
To help helpdesk: a field study of online help systems in campus context

This paper reports on a field‐based study of online help systems at the University of Maryland. After collecting data by means of interview, observation and focus group, analysis is grounded on the contextual data, thus shedding light on particular organizational and human behavioral issues on online help systems. The objectives of this research are to offer insights, enhance understandings, and provide a meaningful guide to design online help systems for educational institutions. Based on the contextual information and data analyses, several constructive thoughts are brought forward, along with the prototype system, for campus‐wide online help systems design. These implications include developing more time‐critical and task‐sensitive online help, merging CMC approaches, and customizing online help in terms of different user groups, even towards specialized online help systems. The limitations of this research are enunciated and future research as well.
Acute toxicity of propoxyphene salts

Abstract The acute toxicity of oral and parenteral doses of propoxyphene HCl was studied in laboratory animals. Large iv, im, or ip doses of propoxyphene HCl produced clonic and tonic convulsions in mice, rats, and dogs. Death from oral doses of propoxyphene HCl was preceded by convulsions in dogs but not in rodents or rabbits. Other effects included hypoactivity and body rigidity in rodents, and salivation, ataxia, and weakness in dogs. Animals given lethal doses of propoxyphene showed profound respiratory depression, which was judged to be the primary cause of death. Respective LD50 values for propoxyphene HCl in the mouse, rat, and dog were 28, 15, and 29 mg/kg iv and 282, 230, and 100 mg/kg po. Comparative acute oral toxicity tests were conducted on the 2-naphthalene sulfonate (napsylate) salt of propoxyphene. In equimolar doses, propoxyphene napsylate, a relatively insoluble salt, was about one-half as toxic as propoxyphene HCl in rodents and clearly less toxic in dogs. Plasma concentrations of propoxyphene indicated that the differences in the acute oral toxicity of propoxyphene HCl and propoxyphene napsylate were due to the more gradual absorption of the latter salt.
Water‐soluble conjugated polymers: Synthesis and optical properties

Two sets of water-soluble poly(phenylene vinylene)s were synthesized and their optical properties were studied. The aqueous solubility of all these polymers is rendered by pendant sulfonate groups. One set of polymers (polymer I series) contains, in addition to the sulfonate pendants, dimethoxy substituents, while the other (polymer II series) contains oligo(ethylene oxide) side chains. Within each set, polymers containing lithium (Ia and IIa), sodium (Ib and IIb), and potassium (Ic and IIc) counter ions were prepared. The two sets of polymers showed different properties from physical appearance (fiber vs film) to thermal properties and to optical properties. It was found that set I polymers, with shorter side chains, exhibit stronger aggregation in aqueous solutions than set II polymers, which led to their lower fluorescence quantum yields and lower polymer-to-MV2+ quenching efficiencies. Within each set, the effect of counter ions on optical properties was noted. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 5123–5135, 2007
Development of Caries in the Hunt-Hoppert Caries-Susceptible and Caries-Resistant Rats Under Different Experimental Conditions

Rats of both Hunt-Hoppert lines, originally designated as caries-susceptible (Ca-S) and caries-resistant (Ca-R) lines, were highly susceptible to caries when subjected to a combination of diet and microflora that provided a challenge to the resistance of all surfaces of the teeth. Strain differences were indicated by the predominance of sulcal lesions in the Ca-S line and smooth-surface lesions in the Ca-R line.
Glucose oxidase entrapped in polypyrrole on high-surface-area Pt electrodes: a model platform for sensitive electroenzymatic biosensors

Abstract Enzyme entrapped in an electrosynthesized polymer film on a high-surface-area electrode is shown to be an attractive platform for the important class of amperometric biosensors based on oxidases and electrooxidation of the H2O2 generated by enzyme-catalyzed oxidation of analyte. Two Pt electrode surface morphologies, Pt black (Pt-BLK) and Pt nanowire brush (Pt-NW) were electrodeposited from chloroplatinic acid. Glucose oxidase (GOx) served as the model enzyme, which was entrapped in an electropolymerized polypyrrole (PPY) film on the high-surface-area Pt electrodes. The glucose sensitivity of the GOx electrodes can be controlled simply through Pt deposition conditions and varies roughly linearly with electrode microscopic roughness factor. A sensitivity of 103 μA mM−1 cm−2 was achieved with the Pt-BLK/PPY-immobilized GOx system at an underlying electrode surface roughness of 318, which is 150-fold higher than the sensitivity of a bare evaporated Pt/PPY-immobilized GOx electrode with a surface roughness of ∼2–3. The apparent Michaelis constant for PPY-immobilized GOx (∼30 mM) is similar to that for free enzyme (25 mM) suggesting that the overall electrode kinetics are not limited by glucose mass transfer. Scanning electron micrographs of enzyme electrode surfaces and a fluorescence assay to determine immobilized GOx concentration revealed that the PPY-GOx layer is deposited as a thin film that follows the contours of the electrode surface and that up to 3-fold greater enzyme is entrapped on the roughest electrodes examined. The orders of magnitude greater sensitivity of enzyme electrodes based on high-surface-area Pt appears likely to be due to increased H2O2 electrooxidation efficiency.
Major genes control hormone-induced ovulation rate in mice

The present study examined the magnitude of genetic variation, mode of inheritance and number of loci controlling major genetic differences in hormone-induced ovulation rate in mice. Mice were injected with 5 i.u. PMSG at 28 days of age and 5 i.u. hCG at 30 days, and hormone-induced ovulation rate was determined from counts of oviducal eggs in cumulus the next morning. Six-fold genetic differences in induced ovulation rate were detected amongst strains, ranging from a low mean (+/- s.e.) value of 8.8 (+/- 0.9) in A/J up to 53.5 (+/- 2.2) in C57BL/6J. The number of ova differed significantly amongst strains and amongst F1 crosses (P less than 0.0001): 70% of the variation in hormone-induced ovulation rate was amongst strains. Of 9 F1 crosses examined, 4 showed positive heterosis, 3 showed no heterosis and 2 showed negative heterosis for hormone-induced ovulation rate. Analysis of parental, F1 and F2 generations revealed that the induced ovulation rate of A/J and C57BL/6J mice differed due to the action of about 3 or 4 loci, and A.SW/SnJ and SJL/J mice differed due to the action of about 2 to 3 loci. Analysis of recombinant inbred strains formed from A/J and C57BL/6J confirmed that these strains differed due to the action of a small number of loci. This study demonstrates the existence of a small number of major genes controlling hormone-induced ovulation rate in young mice.
Experimental Acute Amebic Colitis in Dogs.

Summary1. By utilizing a technic whereby muco-sanguinous exudate f rom active cases of amebic colitis in dogs is injected per anum into the distal portion of the ileum, infection corresponding to spontaneous amebiasis in this host has been produced in 13 out of 14 dogs (93%), ranging in age from 2 months to 4 years. 2. The incubation period, as determined by the presence of active Endanzoeba histolytica in mucus withdrawn directly from the cecum, has ranged from one to 23 days, with the largest number of findings on the second day. 3. Acute cases, probably complicated by bacteremia, terminate with death in about 2 weeks. Chronic cases and one spontaneous recovery have also been observed. Carrier cases, with the passing of cysts in the stools, apparently do not develop in dogs. 4. The cecum is the primary seat of infection with E. histolytica in the dog. 5. The dog apparently receives its amebic infection from man but due to the failure to produce cysts the infection apparently cannot be transferred in nat...
Comments on 'Elastically scattered recoil nuclei in solid-state detectors'

Horn and Von Oertzen (1967) have shown that tracks in mica are produced by an irradiation with 32-MeV O-16 ions. These tracks were attributed to K and Fe recoils produced by elastic scattering of the incident oxygen beam. In the present work an alternate explanation of their observations is provided. The measured characteristics of the tracks are shown to be compatible with theoretical predictions for production of tracks by inelastic (mostly compound nucleus) reactions with silicon and to be inconsistent with the previously proposed elastic scattering process. The possibility that the tracks are produced by contaminant ions in the beam cannot be ruled out.
Kidney stones and renal transplantation.

Abstract Only 10 cases of renal calculi in transplanted kidneys are reported in the literature. Etiology is not uniform in all the cases. Some of these cases were managed conservatively. We herein report a case, in which the etiology of the stone may be urinary tract infection. This patient was managed conservatively.
Mobitz Type II Block without Bundle-Branch Block

His bundle (H) electrograms were recorded in three patients with Mobitz type II block and narrow QRS. Block was secondary to digitalis intoxication in one patient. In the second patient, who had first-degree A-V block, type II block occurred with atrial pacing at a slightly increased heart rate. In the third patient, who had corrected transposition of the great vessels, type II block occurred spontaneously. In two additional patients, block simulating type II block was noted. In one, block of single P waves occurred with carotid massage. In the other, Wenckebach periods with small increments in P-R (and P-H) intervals resembled episodes of type II block. In all five patients, block was proximal to H, suggesting the A-V node as the site of block. The conduction defects in these patients were not progressive; none of the patients needed a pacemaker. Although these mechanisms were identified in patients with narrow QRS complexes, they could occur with bundle-branch block suggesting an erroneous diagnosis of ...
The nature of vital engagement in adulthood

Vital engagement, an absorbing and meaningful relationship between self and world, can be found in any sphere of life. This chapter describes the general phenomenon of vital engagement in adulthood to suggest what may lie ahead for engaged youth.
In-Chip Device-Layer Thermal Isolation of MEMS Resonator for Lower Power Budget

This paper presents a thermally isolated ovenized design of MEMS resonator. Ovenization (joule heating) is done to compensate for the temperature dependence of resonator frequency. An ovenized resonator has a stable frequency over a wide temperature range of -40°C to 85°C. However, the ovenized designs lead to power consumption because of joule heating. It is therefore necessary to thermally isolate the device in order to reduce the power consumption. In this paper, we demonstrate an in-chip thermal isolation and heat delivery within the device layer of the silicon resonator that reduces the power requirement without compromising on the overall performance of the device. A power consumption of 12mW for an ovenized MEMS resonator, built within a wafer-scale encapsulation process, is reported here.Copyright © 2006 by ASME
Celsus on geriatrics.

The author quotes many of Celsus' astute observations on the characteristics of the aged and recommendations for treatment of their diseases. If the pertinence of these observations—made in the first century A.D.—seems surprising, it may be because of the contrast with our present-day obtuseness in the field of geriatrics.
The role of the adrenal medulla in neural control of blood pressure in rats.

The role of the adrenal medulla in the regulation of blood pressure was assessed in rats. In conscious intact (SHAM) and adrenal demedullated (DEMED) animals, baseline blood pressures and heart rates were not different. Moreover, equivalent pressor and depressor response curves to norepinephrine and sodium nitroprusside were obtained. Plasma concentration and 24 hr urinary excretion of norepinephrine were not altered by demedullation. However, epinephrine was undetectable in the urine of the DEMED rats. The effectiveness of the demedullation was further evidenced by a greater than 99% decrease in the epinephrine and norepinephrine content of the adrenal glands of DEMED animals. In pithed SHAM rats, electrical stimulation of preganglionic sympathetic neurons (.5 to 16 hz) elicited marked increases in plasma epinephrine indicating adrenal stimulation, whereas in DEMED rats there were no increases. Furthermore, increments in plasma norepinephrine were significantly reduced in DEMED rats, yet the blood pressu...
THE OCCURRENCE OF PARATHYROID TISSUE WITHIN THE THYMUS: REPORT OF FOUR CASES

Aberrant parathyroid glands have been observed frequently in the thymic tissue of lower animals, but such observations are rare in man. The recent development of parathyroid surgery makes this “thymic” location of the parathyroids of interest to the surgeon as well as to the pathologist and endoerinologist. Four such cases, found in the routine autopsy material of the University Hospital, Ann Arbor, Michigan, are apparently the first to be reported in this country. The four cases include two showing heterotopia of parathyroid in thoracic thymus and two with parathyroid nodules in cervical thymus. The parathyroids (1) are formed from small dorsal diverticula of the endothelial cells of the third and fourth pharyngeal pouches. These cells lose their attachment to the primitive pharynx by atrophy of the connecting ducts, and are free to migrate caudally so that the pair from the fourth pouch are located on each side in the tunica propria of the medial surface of the lateral thyroid lobes at the level of the ...
Toward the manufacture of red blood cells

In this issue of Blood , Lu and colleagues describe a new method to differentiate human embryonic stem cells into large amounts of mature red blood cells. Although the red blood cell supply is currently very safe, a donorless industrial process to manufacture red blood cells for transfusion is
Mcl-1 degradation during hepatocyte lipoapoptosis

The mechanisms of free fatty acid-induced lipoapoptosis are incompletely understood. Here we demonstrate that Mcl-1, an anti-apoptotic member of the Bcl-2 family, was rapidly degraded in hepatocytes in response to palmitate and stearate by a proteasome-dependent pathway. Overexpression of a ubiquitin-resistant Mcl-1 mutant in Huh-7 cells attenuated palmitate-mediated Mcl-1 loss and lipoapoptosis; conversely, short hairpin RNA-targeted knockdown of Mcl-1 sensitized these cells to lipoapoptosis. Palmitate-induced Mcl-1 degradation was attenuated by the novel protein kinase C (PKC) inhibitor rottlerin. Of the two human novel PKC isozymes, PKCδ and PKCθ, only activation of PKCθ was observed by phospho-immunoblot analysis. As compared with Jurkat cells, a smaller PKCθ polypeptide and mRNA were expressed in hepatocytes consistent with an alternative splice variant. Short hairpin RNA-mediated knockdown of PKCθ reduced Mcl-1 degradation and lipoapoptosis. Likewise, genetic deletion of Pkcθ also attenuated Mcl-1 degradation and cytotoxicity by palmitate in primary hepatocytes. During treatment with palmitate, rottlerin inhibited phosphorylation of Mcl-1 at Ser159, a phosphorylation site previously implicated in Mcl-1 turnover. Consistent with these results, an Mcl-1 S159A mutant was resistant to degradation and improved cell survival during palmitate treatment. Collectively, these results implicate PKCθ-dependent destabilization of Mcl-1 as a mechanism contributing to hepatocyte lipoapoptosis.
H2 generation from thermochemical water-splitting using yttria stabilized NiFe2O4 core-shell nanoparticles

This investigation reports synthesis of core-shell NiFe2O4/Y2O3 nanoparticles by sol-gel technique and their H2 volume generation ability via thermochemical water-splitting reaction at 900 °C–1100 °C. Thermochemical water-splitting process involves a cyclic operation of a low-temperature water-splitting step and relatively high temperature regeneration step using redox materials. Because of the cyclic nature of the process, the redox materials undergo thermal fatigue leading to grain growth or sintering, consequently, steady H2 production is not realized in multiple thermochemical cycles. In this study, attempts were made to achieve steady H2 volume generation in multiple thermochemical cycles using core-shell nanoparticles, which were synthesized using precursors such as NiCl2, FeCl2, and YCl3, and pluronic P123 surfactant template. H2 volume generated by NiFe2O4/Y2O3 core-shell nanoparticles was found to be relatively stable over multiple thermochemical cycles. Contrasting to this, the H2 volume generat...
Metadata-driven ad hoc query of patient data: meeting the needs of clinical studies.

Clinical study data management systems (CSDMSs) have many similarities to clinical patient record systems (CPRSs) in their focus on recording clinical parameters. Require- ments for ad hoc query interfaces for both systems would therefore appear to be highly similar. However, a clinical study is concerned primarily with collective responses of groups of subjects to standardized therapeutic interventions for the same underlying clinical condition. The parameters that are recorded in CSDMSs tend to be more diverse than those required for patient management in non-research settings, because of the greater emphasis on questionnaires for which responses to each question are recorded separately. The differences between CSDMSs and CPRSs are reflected in the metadata that support the respective systems' operation, and need to be reflected in the query interfaces. The authors describe major revisions of their previously described CSDMS ad hoc query interface to meet CSDMS needs more fully, as well as its porting to a Web-based platform.
How frequently are home pregnancy tests used? Results from the 1988 National Maternal and Infant Health Survey.

ABSTRACT: Many women use commercially available home pregnancy tests to determine their pregnancy status before seeking professional health care. Despite the increasing popularity of these products, no national estimates have been reported to date on their frequency of use. We analyzed available data from the 1988 National Maternal and Infant Health Survey to determine the frequency of use of home pregnancy tests during recent pregnancies of women of varying sociodemographic backgrounds. Approximately 33 percent (N= 4700) of the women surveyed used such a device. Use was most frequent among women who were white, married, over age 39 years, highly educated, or had a high family income. We conclude that home pregnancy testing appears to be a frequent procedure, especially among women of high socioeconomic background.
Acoustoelectrooptic multichannel spectrum analyzer.

The acoustoelectrooptic effect is combined with the conventional acoustooptic spectrum analyzer. This eliminates the trade-off between the bandwidth and diffraction efficiency and the bandwidth limit of the ordinary acoustooptic spectrum analyzer. Three possible schemes for realizing this concept are proposed.
Evidence for Clonal Outgrowth of Androgen-independent Prostate Cancer Cells from Androgen-dependent Tumors through a Two-Step Process

Prostate cancers require androgen for growth but progress to an androgen-independent stage under the selective pressure of androgen ablation therapy. Here we describe a novel human prostate cancer xenograft (LAPC-9) propagated by serial passage in male severe combined immunodeficient mice that expresses prostate-specific antigen and wild-type androgen receptor. In response to castration, LAPC-9 cells undergo growth arrest and persist in a dormant, androgen-responsive state for at least 6 months. After prolonged periods of androgen deprivation, spontaneous androgen-independent outgrowths develop. Thus, prostate cancers progress to androgen independence through two distinct stages, initially escaping dependence on androgen for survival and, subsequently, for growth. Through the use of serial dilution and fluctuation analysis, we provide evidence that the latter stage of androgen independence results from clonal expansion of androgen-independent cells that are present at a frequency of about 1 per 10(5)-10(6) androgen-dependent cells. We conclude that prostate cancers contain heterogeneous mixtures of cells that vary in their dependence on androgen for growth and survival and that treatment with antiandrogen therapy provides selective pressure and alters the relative frequency of these cells, thereby leading to outgrowths of androgen-independent cancers.
Nest Predators and Fragmentation: a Review and Meta-Analysis

Population declines of many avian species are often attributed to increased rates of nest predation in fragmented landscapes, yet mechanisms underlying these effects have rarely been examined. We reviewed the literature to determine the extent to which hypotheses about nest predators and fragmentation have been invoked and compared this to the number of direct tests of predators with respect to habitat edge, patch size, or landscape type. We also conducted a meta-analysis of tested predator effects to evaluate whether predator responses—numerical, functional, or species richness—to fragmentation depend on spatial scale (edge, patch, or landscape), landscape type, geographic region, or predator taxa. We found 120 papers containing hypoth- eses about nest predators and fragmentation, but only 31 with hypothesis tests. Most tests were of a single predator species or guild, whereas most cited hypotheses generalized across broader taxonomic groups. Re- sults of predator tests were variable, but some general patterns were evident. Predator effects, including in- creased abundance, activity, or species richness in edges, small patches, or certain landscapes, were more prevalent (1) in tests conducted at the landscape scale than at the local scale, (2) in agricultural landscapes than in predominantly forested landscapes, (3) in certain biogeographic regions, and (4) for avian predators than for mammalian predators. Local-scale (edge and patch) effects were most common when the land sur- rounding patches was agricultural and when tests were conducted within agricultural landscapes. The re- sponse of nest predators to fragmentation is complex, taxon-specific, and context-dependent. Conservation ef- forts for declining avian species may therefore need to be customized according to the nest-predator species primarily responsible for local nest mortality and the nature of the landscape mosaic.
Ethnic Segregation in Arizona Charter Schools

Among the criticisms of charter schools is their potential to further stratify schools along ethnic and class lines. This study addressed whether Arizona charter schools are more ethnically segregated than traditional public schools. In 1996-97, Arizona had nearly one in four of all charter schools in the United States. The analysis involved a series of comparisons between the ethnic compositions of adjacent charter and public schools in Arizona's most populated region and its rural towns. This methodology differed from the approach of many evaluations of charter schools and ethnic stratification in that it incorporated the use of geographic maps to compare schools' ethnic make-ups. The ethnic compositions of 55 urban and 57 rural charter schools were inspected relative to their traditional public school neighbors.
The effects of hypoxia on growth cones in the ovine fetal brain.

Objective: This study was designed to investigate the effects of hypoxia on neural process proliferation by studying its effects on growth cone tubulin and insulin-like growth factor (IGF)-I receptor content.Methods: Six fetal lambs were catheterized in the brachial artery and vein. Maternal oxygenation was reduced in steps from a fractional inspired oxygen concentration (FiO2) of 20% to 6% by addition of nitrogen to the inhaled gas mixture for a period of 4 h of reduced oxygen intake. Fetal arterial blood was sampled after the maternal FiO2 and oxygen were stable for > 5 min at maternal FiO2 of 20% to 6%. Controls were obtained from normoxic fetuses whose ewes had similar surgery and were kept at an FiO2 of 20% throughout the experiment. Growth cones were isolated from the fetal cerebrum and cerebellum. α-Tubulin and IGF-I receptors were quantified by immunoblotting. Tubulin and IGF-I receptor mRNA expressions were quantified by real-time polymerase chain reaction.Results: Maternal nitrogen breathing red...
Concept mapping, Vee mapping, and achievement: Results of a field study with Black high school students.

This article reports on the results of a project that studied the effectiveness of two specific learning heuristics, concept mapping and Vee mapping, in helping black, inner-city, high school students learn biology concepts meaningfully. The project sought to assess the effects on achievement of the use of these two heuristics as part of a carefully designed sequence of instruction. Two instructional treatments were compared, one that utilized the two experimental heuristics as study aids and one that utilized outlining as a comparison study aid. The instructional treatments were administered over approximately a one semester period. Two hundred and fifty subjects, nearly all black, from two urban high schools in Indiana took part in the study. Achievement instruments designed to measure meaningful (higher order) learning were developed. Analysis of variance of the achievement test means failed to reveal statistically significant differences between the experimental and comparison treatment at the 0.05 alpha level. However, there were suggestions of a tendency toward an effect of the experimental treatment, and several factors contributing to the difficulty in distinguishing achievement differences were identified.
Cancer stem cells: progress and challenges in lung cancer

The identification of a subpopulation of tumor cells with stem cell-like characteristics first in hematological malignancies and later in solid tumors has emerged into a novel field of cancer research. It has been proposed that this aberrant population of cells now called "cancer stem cells" (CSCs) drives tumor initiation, progression, metastasis, recurrence, and drug resistance. CSCs have been shown to have the capacity of self-renewal and multipotency. Adopting strategies from the field of stem cell research has aided in identification, localization, and targeting of CSCs in many tumors. Despite the huge progress in other solid tumors such as brain, breast, and colon cancers no substantial advancements have been made in lung cancer. This is most likely due to the current rudimentary understanding of lung stem cell hierarchy and heterogeneous nature of lung disease. In this review, we will discuss the most recent findings related to identification of normal lung stem cells and CSCs, pathways involved in regulating the development of CSCs, and the importance of the stem cell niche in development and maintenance of CSCs. Additionally, we will examine the development and feasibility of novel CSC-targeted therapeutic strategies aimed at eradicating lung CSCs.
An Integrative Methodology for Product and Supply Chain Design Decisions at the Product Design Stage

Supplier selection is one of the key decisions in supply chain management. Companies need not only to make the "make" or "buy" decisions but also differentiate across potential suppliers in order to improve operational performance. Product design is an engineering based activity that realizes the customer requirements into functions of a new product. Many studies have pointed out that the integration of product and supply chain is a key factor for profitability and efficiency. However, most studies address supply chain performance after freezing the design of the product; only a few studies discuss when and how to incorporate supply chain decisions during product design. This paper presents a graph theory based optimization methodology to tackle this problem. The supplier selection issue is considered by evaluating its impact on both internal (e.g., ease of assembly) and external (e.g., transportation time) enterprise performances, which are aggregated as supply chain performance at the conceptual design stage. A case study in the bicycle industry demonstrates the advantages of this methodology. The presented mathematical programming formulation enables simultaneous optimization of both product design and supply chain design during the early design stages.
Effect of pH on the reactivity ratios in the copolymerization of acrylic acid and acrylamide

The content of acrylic acid and acrylamide in their copolymers can be controlled by changing pH. The reactivity ratio of acrylic acid decreases with increasing pH, while the reactivity ratio of acrylamide increases with increasing pH. At low pH values, acrylamide is present in its protonated form which causes its reactivity to be low whereas at high pH values the reactivity of acrylic acid is decreased owing to its dissociation. When the monomer and radical approach each other, the acrylate anion becomes the least reactive species because of its symmetrical charge distribution, like charge repulsion and barium ion screening effect. HMO calculations were performed for models of all monomers and polymer radicals involved in copolymerizations. The experimental results concerning the reactivity of acrylic acid and acrylamide in copolymerization and the observed reactivity ratios were discussed on the basis of HMO calculations and resonance and Coulomb electrostatic effects. The observed reactivity ratios were correlated with the calculated differences in resonance energies computed for the models of transition states involved in copolymerizations.
Microbial biosensor for direct determination of nitrophenyl-substituted organophosphate nerve agents using genetically engineered Moraxella sp.

A microbial biosensor consisting of a dissolved oxygen electrode modified with the genetically engineered PNP-degrader Moraxella sp. displaying organophosphorus hydrolase (OPH) on the cell surface for sensitive, selective, rapid and direct determination of p-nitrophenyl (PNP)-substituted organophosphates (OPs) is reported. Surface-expressed OPH works in tandem with the PNP oxidation machinery of the Moraxella sp. to degrade PNP-substituted OPs and PNP simultaneously while consuming oxygen, that is proportional to the analyte concentration. The optimum performance was obtained by electrodes constructed using 0.35 mg dry weight of cell and operating at pH 7.5. Operating at optimum conditions the biosensor was able to measure as low as 0.1M (27.5 ppb) of paraoxon and had excellent selectivity against triazines, carbamates and OPs without PNP substitutent. The biosensor was stable for a week when stored at 4 ◦ C. The applicability of the biosensor to measure OPs in lake water was demonstrated. © 2005 Published by Elsevier B.V.