cssi/SciSciGPT-SciSciNet huggingface dataset:
Release of ACh from the carotid body by hypoxia and hypoxia plus hypercapnia

Abstract Perfusing the isolated carotid bodies of 27 dogs in vivo with heparinized-eserinized blood, equilibrated with room air, 5% O2, 15% CO2, 5% O2 + 15% CO2, produced: an increase in ventilation during hypoxia of +149%; hypercapnia, +19%; hypoxia + hypercapnia, +235%. Carotid body venous outflow contained 1966 pg/ml ACh (±374) during hypoxia and 2807 pg/ml ACh (± 340) during hypoxia + hypercapnia. ACh was not recovered during room air or hypercapnia. After perfusion with a hemicholinium, HC-3, the ventilation increase declined to + 83 % during hypoxia, and to + 116% during hypoxia + hypercapnia, with no increase during hypercapnia; ACh declined during hypoxia to 1264 pg/ml (±179) and to 1661 pg/ml (±259) during hypoxia + hypercapnia. This study supports the hypothesis that a cholinergic substance is a factor in carotid body chemoreceptor activity.
Complementary column generation and bounding approaches for set partitioning formulations

We present a complementary column generation feature that produces tight upper bounds, thereby enhancing heuristic and exact column generation approaches for (minimization) set partitioning formulations that possess dense column structures. We also introduce a duality-based lower bound that prompts a useful termination criterion, which can be utilized to mitigate the tailing-off effect induced by column generation approaches. Computations are presented for the one-dimensional bin packing problem and a joint vehicle assembly-routing problem.
Effective Management of Difficult Surgical Defects Using Tissue‐Engineered Skin

Background. Graftskin, a bilayered living skin construct, is an effective therapeutic option in the management of chronic venous ulcerations and simple acute surgical excisions. However, it is not routinely used in the management of complicated surgical wound defects. Objective. To determine the effectiveness of graftskin as a therapeutic modality in difficult surgical defects. Methods. Two patients with complex surgical wound defects after Mohs micrographic surgery underwent a single application of graftskin. The engineered skin was fenestrated and sutured in place. The wounds were examined on a weekly basis. One hundred percent healing was defined as complete reepithelialization (wound coverage). Results. Graftskin was well tolerated by these patients and resulted in complete wound healing within 9 weeks of application. Conclusion. Graftskin is an excellent alternative for difficult surgical wounds not amenable to other therapies. Graftskin results in a shortened healing time and decreased morbidity. It should be considered for wounds in which healing by secondary intention is preferably avoided.
Numerical and experimental study of an axisymmetric coflow laminar methane–air diffusion flame at pressures between 5 and 40 atmospheres

A numerical and experimental study of an axisymmetric coflow laminar methane-air diffusion flame at pressures between 5 and 40 atm was conducted to investigate the effect of pressure on the flame structure and soot formation characteristics. Experimental work was carried out in a new high-pressure combustion chamber described in a recent study [K.A. Thomson, O.L. Gulder, E.J. Weckman, R.A. Fraser, G.J. Smallwood, D.R. Snelling, Combust. Flame 140 (2005) 222-232]. Radially resolved soot volume fraction was experimentally measured using both spectral soot emission and line-of-sight attenuation techniques. Numerically, the elliptic governing equations were solved in axisymmetric cylindrical coordinates using the finite volume method. Detailed gas-phase chemistry and complex thermal and transport properties were employed in the numerical calculations. The soot model employed in this study accounts for soot nucleation and surface growth using a semiempirical acetylene-based global soot model with oxidation of soot by O{sub 2}, OH, and O taken into account. Radiative heat transfer was calculated using the discrete-ordinates method and a nine-band nongray radiative property model. Two soot surface growth submodels were investigated and the predicted pressure dependence of soot yield was compared with available experimental data. The experiment, the numerical model, and a simplified theoretical analysis found thatmore » the visible flame diameter decreases with pressure as P{sub a}{sup -0.5}. The flame-diameter-integrated soot volume fraction increases with pressure as P{sub a}{sup 1.3} between 5 and 20 atm. The assumption of a square root dependence of the soot surface growth rate on the soot particle surface area predicts the pressure dependence of soot yield in good agreement with the experimental observation. On the other hand, the assumption of linear dependence of the soot surface growth rate on the soot surface area predicts a much faster increase in the soot yield with pressure than that observed experimentally. Although pressure affects the gas-phase chemistry, the increased soot production with increasing pressure seems primarily due to enhanced mixture density and species concentrations in the pressure range investigated. The increased pressure causes enhanced air entrainment into the fuel stream around the burner rim, leading to accelerated fuel pyrolysis. In the pressure range of 20 to 40 atm both the model and experiment show a diminishing sensitivity of sooting propensity to pressure with a greater decrease in the predicted sensitivity of soot propensity to pressure than the experimental results. (author)« less
Flow, heat transfer, and pressure drop in the near-wall region of louvered-fin arrays

Abstract Using the naphthalene sublimation technique and complementary flow visualization, the effects of bounding walls on flow and heat transfer in louvered-fin arrays are studied. Results for spatially periodic flow far from the walls are compared to results for the near-wall flow, where the impact of the bounding surface is important. In contrast to flow in the spatially periodic region, the near-wall flow is characterized by large separation zones between the louvers, and unsteadiness is manifest at much lower Reynolds numbers than in the spatially periodic region. At low Reynolds numbers (Re≈600 and below in this study) the large separation zones cause a decrease in heat transfer of up to 50%. However, if the Reynolds number is high enough to promote unsteady flow near the wall, the net effect is to locally increase heat transfer by up to approximately 15% (at Re=1400). Unfortunately, this increased heat transfer is accompanied by a several hundred percent increase in pressure drop. A formula for characterizing the spatial extent of these wall effects is presented.
Cognitive-behavioral treatment of older adults with obsessive-compulsive disorder

Despite substantial evidence supporting the general efficacy of cognitive behavioral treatment for obsessive-compulsive disorder (OCD), little has been written to guide practitioners treating older adults with this potentially disabling condition. The present article reviews the research literature on the cognitive behavioral treatment of elders with OCD and discusses adaptations of treatment that may be required to respond effectively to clinical issues and challenges associated with this disorder in later life. Though more research is clearly needed, preliminary findings suggest exposure and response prevention is effective with older adults. However, practitioners may need to adjust clinical procedure to address medical comorbidity and physical and cognitive limitations associated with aging, cultural issues and attitudes that may promote treatment resistance and nonadherence, the influence of family members and other caretakers, and complications presented by stressors and fears common in older adults.
Influence of taste stimulation during the suckling period on adult taste preference in rats.

Abstract Effects of taste deprivation and selective taste exposure during the suckling period on adult preference for flavored solutions was examined. Taste deprivation was achieved by rearing rat pups “artificially,” in individual cups with intragastric feeding from Postnatal Days 4 through 17 or 18. In the first study the effects of artificial rearing on male Long-Evans rats were examined. In the second study female Wistar rats were exposed to a single tastant, sucrose, which was introduced on a background of taste deprivation. Results of both studies were similar. No differences in taste sensitivity or preference were detected between animals subjected to taste deprivation or selective taste exposure and their normally reared littermates. These results suggest that suckling stimulation is not necessary for normal taste development and that the taste system of the rat is not particularly susceptible to the influence of early experience. Other interpretations of these results are also discussed.
An experimental study on wind loads acting on a high-rise building model induced by microburst-like winds

Abstract In the present study, an experimental investigation is conducted to quantify the characteristics of the microburst-induced wind loads (i.e., both static and dynamic wind loads) acting on a high-rise building model, compared to those with the test model placed in conventional atmospheric boundary layer (ABL) winds. The experimental study is performed by using an impinging-jet-based microburst simulator available at Iowa State University. In additional to conducting flow field measurements to quantify the flow characteristics of the microburst-like wind, both mean and dynamic wind loads acting on the test model induced by the microburst-like wind are assessed in detail based on the quantitative measurements of the surface pressure distributions around the test model and the resultant aerodynamic forces. It is found that the microburst-induced wind loads acting on high-rise buildings would be significantly different from their counterparts in conventional ABL winds. Both the static and dynamic wind loads acting on the high-rise building model were found to change significantly depending on the radial locations and the orientation angles of the test model in respect to the oncoming microburst-like wind. The dynamic wind loads acting on the test model were found to be mainly influenced by the periodical shedding of the primary vortices and the high turbulence levels in the microburst-like wind. The findings derived from the present study are believed to be useful to gain further insight into the underlying physics of the flow–structure interactions of high-rise buildings in violent microburst winds for a better understanding of the damage potential of microburst winds to high-rise buildings.
Silicon Photonics Opportunity, Applications & Recent Results

Thanks to the entire PTL and Fab 8 team at Intel! ? Long term convergence opportunites will be in silicon ? Silicon photonic device performance progress accelerating ? Need to continue to push performance (10G, 40G...) ? Next phase of challenges will be with integration ? For interconnects, need to optimize electronics & photonics ? Packaging, power, signaling, and cost will be key
The Effects of Capitation on Outpatient Mental Health Episodes of Children

We analyzed the effects of the Colorado Medicaid Capitation Program on the duration and services of over 21,000 outpatient mental health episodes for young children. The study spanned a three year period before and after capitation was implemented, and compared episodes of outpatient care for children from 14 capitated Community Mental Health Centers (CMHCs) with those from three CMHCs that remained fee-for-service. Proportional hazards regressions revealed that capitation resulted in an increase in outpatient episode duration, over and above similar effects for the comparison fee-for-service episodes. The hypothesis that there were longer capitated episodes for children who were hospitalized was not supported. Children with behavioral and anxiety disorders had longer capitated episodes. Service intensity decreased over time in the managed care sites. Changes in case mix may have had an impact on changes in episode duration and service intensity. That outpatient episode duration increased over time while costs were lowered in the capitated agencies indicates some effects of capitation in changing patterns of care.
Culturally Diverse Parents' Experiences in Their Children's Transition Knowledge and Involvement

Despite the benefits of parental involvement in a student's transition planning process, the reality is that parents of students with disabilities are often not adequately involved. This problem is particularly salient with regard to culturally diverse parents. The purpose of this study was to gather in-depth information about parents' experiences in the transition planning process. Nineteen African American, Asian American, European American, and Hispanic parents of 19 high school students with disabilities were interviewed by telephone regarding their knowledge and involvement in their children's transition planning process. Emergent themes included a lack of knowledge regarding transition planning, the importance of attending Individualized Education Program and transition meetings, the importance of employment, the importance of home support, and parental emotions as barriers.
Plasma treatment to improve amorphous silicon solar cell's performance

Amorphous silicon-based solar cell is usually composed of two or three multi-junctions, and each of them is formed by a p-layer, an intrinsic layer (i-layer), and an n-layer. The interfaces formed by these layers have been found to play a key role in determining cell performance. Among the interfaces, the p/i interface can be more obviously influential on cell performance, such as open circuit voltage (Voc), fill factor (FF), etc. This is because holes have much low mobility compared with electrons, thus they are more sensitive to the quality of the p/i interfaces. In this study, we reported results about making use of hydrogen plasma treatment to improve quality of the p/i interface, and finally increasing energy conversion efficiency. Our results show that FF can be obviously increased after the plasma treatment at proper powers. We have increased the energy conversion efficiency by 7% compared to that of the sample without plasma treatment. This study developed one way to optimize amorphous silicon-based solar cell.
A simplified technique for magnetic retention of overdentures

M oghadam and Scandrett’ reviewed the use of implanted and opposing magnets to increase stability and retention of mandibular complete dentures. They also presented a technique using samarium-cobalt (Sm-Co) magnets, which were cut to fit prepared cavities in the roots of remaining endodontically treated mandibular teeth and combined with opposite-pole magnets embedded in the lower denture base. In their study the remaining clinical crowns were reduced to 1.5 to 2 mm in height; then, depending on tooth size, cavities were prepared to a depth of 2 to 3 mm into the pulp chambers and roots of these supporting teeth. An impression of the prepared teeth was made and poured in dental stone to form a working cast. The cavities were then filled with a temporary material, and a border-molded tray was used to make a second impression for a master cast on which the denture would be made. The Sm-Co magnets were cut with high-speed diamond points to fit the prepared cavities on the working cast. A second set of opposing magnets 2 to 3 mm in height, which would later be embedded in the denture base, were then cut and fitted to match the occlusal surface and convexity of each prepared tooth. These magnets were then luted with cyanoacrylate cement in their correct positions to the master cast. These overlay magnets remained fixed to the master cast during wax-up, try-in, boil-out, packing, and processing. They were then removed and fixed in their respective crypts in the denture base acrylic resin. The intracoronal magnets were retrieved from the working cast and cemented into place in the mouth. To provide a proper seal, a shallow groove was cut around each magnet to remove the occlusal cement line, which was then packed with amalgam. The denture was inserted and adjusted. Where suitable teeth remain, the concept of using
Magnetization effect on hydrogen absorption in high-strength steels and its implications

Abstract Magnetization effect of hydrogen absorption in high-strength steels has been investigated and the implications of the results for magnetic flux leakage assessment used for determination of defects in line pipe steels are discussed. A strong and continuous remanent magnetic field in steels at a level commonly residual from magnetic flux leakage assessment practices can result in an increase of up to 1.62 times in the absorbed hydrogen concentration.
Total and net displacement functions for monatomic materials

Abstract Using the atomic scattering cross section and electronic stopping power formulas of Lindhard et al., we have numerically calculated the total and net displacement functions characterizing displacement cascades in amorphous monatomic materials. The dependence of these functions on energy, type of material, displacement threshold, capture threshold, and binding energy is exhibited and discussed. Analytical approximations are given for most of the numerical results.
Low‐voltage scanning electron microscopy of low‐density materials

Delicate microstructures in low-density polymer foams and silica aerogel are susceptible to coating damage, artifact structures induced by coating, and electron-beam damage when they are examined by conventional scanning electron microscopy (SEM) techniques. These problems can be reduced significantly and even eliminated when these materials are examined directly with no coating using low-voltage scanning electron microscopy (LVSEM). Much of the fine structure in these materials also can be resolved at low voltage in a SEM equipped with a field-emission gun (FESEM).
Concurrent vs. Staged Colectomy and Hepatectomy for Primary Colorectal Cancer With Synchronous Hepatic Metastases

Resection of hepatic metastases is the preferred treatment for selected patients after resection of primary colorectal carcinoma, but timing is controversial. This study was designed to compare outcomes of patients receiving concurrent resection of hepatic metastases and the primary colorectal tumor with those of patients receiving staged resection (within 6 months). We retrospectively analyzed medical records (1986–1999) of 96 consecutive patients with synchronously recognized primary carcinoma and hepatic metastases who underwent concurrent (64 patients) or staged (32 patients) colonic and hepatic resections performed at our institution. Concurrent and staged groups were similar in demographics, tumor grade, stage, preoperative comorbidity (cardiac and respiratory), characteristics of hepatic metastases, and single vs. multiple lesions. No significant differences were observed between groups (concurrent vs. staged) in type of colon resection (P = 0.45) or hepatic resection (P = 0.09), overall operative duration (mean, 430 vs. 427 minutes; P = 0.39), blood loss (mean, 890 vs. 889 ml; P = 0.87), volume of blood products transfused (mean, 326 vs. 185 ml; P = 0.08), perioperative morbidity (53 vs. 41 percent; P = 0.25), disease-free survival from date of hepatectomy (median, 13 vs. 13 months; P = 0.53), or overall survival from date of hepatectomy (median, 27 vs. 34 months; P = 0.52). There was no operative mortality. Overall duration of hospitalization was significantly shorter for concurrent than for staged resection (mean, 11 vs. 22 days; P ≤ 0.001). Concurrent colectomy and hepatectomy is safe and more efficient than staged resection and should be the procedure of choice for selected patients in medical centers with appropriate capacity and experience.
A New Digital Phone? [AP-S Turnstile]

How excited would you be if someone offered you a new digital phone receiver that weighed 170 tons and had a data rate of 0.1 Hz? My guess is, probably not too much. How about if the receiver had a truly universal reach, staying in touch under deep seas on planet Earth, or even somewhere out there in the galaxy, in ET country? Well, now you may be giving it a second thought.
Map-based molecular diversity, linkage disequilibrium and association mapping of fruit traits in melon

Melon has tremendous fruit diversity, the product of complex interactions of consumer preferences in different countries and a wide range of agro-climatic zones. Understanding footprints of divergence underlying formation of various morphotypes is important for developing sustainable and high-quality melons. Basic understanding of population structure and linkage disequilibrium (LD) is limited in melon and has lagged behind other crops. Characterization of population structure and LD are essential for carrying out association mapping of quantitative trait loci (QTL) underlying various complex traits. Mapped single-locus microsatellite markers are known to be very valuable for resolving the population structure and 268 such markers were used in the current study to resolve population structure and LD pattern using 87 accessions of melons belonging to Eastern European, Euro-North American and Asian types. A mixed linear model was implemented to detect QTL for various fruit traits. Various levels of QTL with high to moderate stringency were detected for fruit shape, fruit weight, soluble solids, and rind pressure and a majority of them was found to be in agreement with the previously published data, indicating that association mapping can be very useful for melon molecular breeding. Minor discrepancies in the position, strength and the variation explained by the QTL present between the methods of association and recombinant mapping approaches can be bridged if more melon groups and larger sets of accessions are involved in future studies, combined with high-throughput marker panels.
589-nm single-frequency VECSEL for sodium guidestar applications

Here we report on the development and demonstration of a tunable high power single frequency Vertical External Cavity Surface Emitting Laser (VECSEL) operating at 589nm. A highly strained InGaAs/GaAs VECSEL designed to operate at ~ 1178nm is used in conjunction with an intracavity Birefringent Filter (BF) and low finesse Fabry-Perot (FP) etalon to achieve the single frequency operation at the fundamental wavelength. An internal non-linear optical element is then used to obtain the single frequency output at the desired wavelength of 589nm. Our results show outputs in excess of 4W at 589nm with a FWHM linewidth of the fundamental frequency to be less than 10MHz. We demonstrate the measurement of the sodium D1 and D2 lines by passing the output through a reference cell.
POTENTIATION OF VIRUS LEUKAEMOGENESIS IN C57BL MICE BY X-IRRADIATION OR URETHANE.

LYMPHOID tumours can be induced in high incidence in strain C57BL mice by fractionated whole-body X-irradiation1. Urethane has also been shown to act as an independent leukaemogenic agent when administered to C51BL mice shortly after birth2. In adult mice, urethane acts as a co-leukaemogenic agent, potentiating the leukaemogenic effects of radiation or other carcinogenic agents, but exhibits little or no leukaemogenic activity when used alone3.
Gated communities and city marketing: Recent trends in Guaynabo, Puerto Rico

Abstract Surprisingly little work has examined the role of city marketing in the development and promotion of gated communities. Here, I examine how the municipal government of Guaynabo, Puerto Rico reshaped the town’s spaces, facilitating the emergence of gated communities beginning in the 1980s and continuing today. I argue that, during the last decades, city marketing has been used as a tool by the municipality to attract people who are of a higher socioeconomic class. Here, it is suggested that city marketing is an important factor to consider when analyzing the emergence and proliferation of gated communities. Moreover, the gated communities literature will benefit from examining the role of municipalities in seeking an explanation for this growing urban reality.
Fatty Acid Modified Dendrimers in Bulk and Solution: Single-Chain Neutron Scattering from Dendrimer Core and Fatty Acid Shell

Small-angle neutron scattering (SANS) has been applied to extract the single-chain form factors of the fatty acid (FA) and the dendrimer components in bulk and dilute solution of fatty acid modified poly(propyleneimine) dendrimers (Astramol). The fatty acid chains were covalently or noncovalently linked to the end groups of two generations, G3 and G5. Bulk samples were prepared under contrast match conditions of mixtures of dendrimer-h/FAH and dendrimer-h/FAD to obtain the form factor of the fatty acid components. The solutions were prepared with deuterated fatty acid modified dendrimers in decalin solvent using the contrast match technique. Mixtures of decalin-h and decalin-d were used to match either the dendrimer or FA components. The dendrimer core of both G3 and G5 appears collapsed, without the incorporation of a significant amount of solvent. The G3 FA portion has a size closer to that of the bulk than that of a collapsed FA shell. The G5 dendrimer has the opposite trend.
Selective Excitation and Decay of Er 3 + Fluorescence in La F 3

A simple treatment of pulsed and steady-state selective-excitation experiments in multilevel systems is given and used to interpret the fluorescence excitation and decay properties of ${\mathrm{Er}}^{3+}$ in La${\mathrm{F}}_{3}$. Fluorescence from eight different excited states was studied. From excitation spectra and pulsed selective excitation, decay modes were established involving level-by-level nonradiative cascade, arising from multiphonon emission, and level-bypassing radiative transitions. Energy transfer due to ion-ion interactions was deliberately avoided. Using pulsed-excitation techniques, multiexponential time-dependent fluorescences were observed and used to determine the lifetimes of all excited states below 40 000 ${\mathrm{cm}}^{\ensuremath{-}1}$. In general, the smaller the energy gap to the next lower level, the shorter the lifetime, reflecting the dependence of the rate of multiphonon emission on the proximity of other levels. Fluorescence in La${\mathrm{F}}_{3}$ is usually not detected when the energy gap is 1600 ${\mathrm{cm}}^{\ensuremath{-}1}$. Fluorescence lifetimes were also measured as a function of temperature from 77 to \ensuremath{\sim}700\ifmmode^\circ\else\textdegree\fi{}K. Thermal quenching of the fluorescent properties is correlated with the increased importance of nonradiative transitions at higher temperatures.
Input-output problems in simple nerve-ganglion systems.

The dynamics of simple nerve-ganglion systems is studied. The frequency of nerve impulses (action currents) leaving the ganglion is expressed as a function of the frequency of impulses entering the ganglion. The problem is varied by considering ganglia having internal association connections.
A simple trick for repairing coronary pseudoaneurysm complicating a Bentall operation

Coronary pseudoaneurysms are a known complication of the Bentall wrap-inclusion method of composite valve grafting. We describe two cases to illustrate a straightforward technique for repair and prevention of coronary pseudoaneurysm formation.
Effects of mud fiddler crabs (Uca pugnax) on the recruitment of halophyte seedlings in salt marsh dieback areas of Cape Cod (Massachusetts, USA)

The effects of bioturbation by the mud fiddler crab (Uca pugnax) on salt marsh seedling recruitment were investigated experimentally in this study. Burrowing and foraging activity caused a large amount of soil disturbance, which in turn negatively impacted the establishment of seedlings. Either seeds did not germinate or seedlings were uprooted or buried. Although the majority of the published literature suggests a positive influence of Uca spp. on salt marsh plant growth, at high densities they have the potential to hinder the re-colonization of areas made bare by previous disturbance. This study illustrates the perhaps underappreciated role that bioturbators can have on vegetation patterns in salt marshes and other ecosystems.
Histone deacetylase inhibitor uses p21Cip1 to maintain anergy in CD4+ T cells☆☆☆

Abstract T cell anergy defined as antigen-specific proliferative unresponsiveness was induced in CD4+ T cells exposed to antigen (Ag) in the presence of the histone deacetylase (HDAC) inhibitors n-butyrate, trichostatin A or scriptaid. However, the ability of HDAC inhibitors to induce anergy in Th1 cells was not due to general histone hyperacetylation. Instead, the anergy induced by HDAC inhibitors was associated with upregulation of p21Cip1, a secondary effect of histone acetylation. Induction of p21Cip1 in the absence of histone hyperacetylation by exposure to okadaic acid also resulted in T cell anergy. In addition, Ag-specific p21Cip1-deficient CD4+ T cells were much less susceptible to anergy induction by n-butyrate. Thus, p21Cip1 appears to mediate the proliferative unresponsiveness found in CD4+ T cell anergized by exposure to Ag in the presence of HDAC inhibitors.
Spatio-temporal modelling and analysis of urban heat islands by using Landsat TM and ETM+ imagery

In this paper we propose a method for characterizing UHIs by using a non-parametric model. Landsat 5 and 7 images obtained over the city of Indianapolis were used for analysis of UHI over space and time. The images were subjected to kernel convolution implementing Gaussian bi-variate function for non-parametric characterization of the UHI. The convoluted images were then analyzed, for pattern over space and over time. It was found that the spread of the UHI in Indianapolis increased from 13.90 km to 21.63 km in the west-east direction and from 10.98 km to 15.90 km in the north-south direction from 1985 to 2000. The changes in the UHI from 1995 to 2000 were evident in all cardinal directions. The model aided in successfully characterizing UHI in terms of its location, spread, and the rate of increase, facilitating a clearer image of UHI through space and time.
Early turbulence and drag reduction phenomena in larger pipes

SOLUTIONS of certain high molecular weight polymers have been shown to exhibit the phenomena of both early turbulence1–7 and drag reduction4,5,8 depending on whether the measurements were made under laminar flow conditions for the former case or under turbulent flow conditions for the latter. In general, early turbulence has been observed only in capillary tube flows while drag reduction has been observed in a variety of flow geometries, the only requirement being a developing or developed turbulent flow field.
Studies in mathematical biosociology of imitative behavior: I. Effects of income distribution

In connection with previous studies (Rashevsky,Mathematical Biology of Social Behavior, chap. xii), a situation is investigated in which the two mutually exclusive possible behaviors of a society consist of the desire to keep the present socioeconomical situation and the desire to change it inany way. The psychophysiological tendency ϕ towards either of the behaviors is considered to be proportional to the difference between the actual incomei of the individual and his needsi′. Assuming that the distribution functionN1(i′) of the needs is a given characteristic of the population, it is shown that the distribution functionN(ϕ) of ϕ in the society can be derived fromN1(i′) and from the distributionN2(i) of the incomesi. A particular case is worked out as an example. Conditions of stability of a socioeconomic structure are studied in their dependence on the income distribution.
Kinetic formation of CO, CO2, H2, and light hydrocarbon gases from cellulose pyrolysis

Abstract The formation of gaseous products has been examined for cellulose over the temperature range of 360–595°C. The evolution of CO, CO2, H2, CH4, C2H4, and C2H6 was determined as a function of time. The overall kinetic rate constants for decomposition were determined from the formation rates for each gas, as well as the rate constants for the formation of each specific gas. It has been verified that CO and CO2 are both primary products of decomposition, and further emanate from the same kinetic pathway. By increasing the residence time of the reactor, the production of all gaseous products, including both CO and CO2, further increased, indicating production by a secondary reaction mechanism. None of the gaseous products, save CO and CO2, were detected in measurable quantities except at temperatures above which transport limitations had affected the measurement of the kinetic rates.
Initial events involved in the synthesis of the lysosomal enzyme α-mannosidase in Dictyostelium discoideum

Abstract In Dictyostelium discoideum the lysosomal enzyme α-mannosidase is initially synthesized in vivo as a 140,000 Mr protein which is subsequently processed into two mature acidic glycoproteins of 60,000 and 58,000 Mr. To investigate the initial events involved in the synthesis of this protein, mRNA isolated from growing cells was translated in vitro and the resulting protein products were immunoprecipitated with antibodies prepared against the purified enzyme. Messenger RNA prepared from membrane-bound but not free polysomes directed the synthesis of an immunoprecipitable 120K protein that was identified as the α-mannosidase primary translation product by a variety of criteria. Translation in vitro in the presence of dog pancreas microsomes resulted in the conversion of the 120K primary translation product to a 140K form. This 140K species was not accessible to added trypsin under conditions preserving membrane integrity, suggesting it is sequestered in the lumen of the endoplasmic reticulum following synthesis. Treatment of either the in vitro modified or cellular 140K α-mannosidase precursors with endoglycosidase H resulted in the appearance of proteins 2K larger than the primary translation product. The pulse-labeled cellular precursor and the in vitro processed form have similar isoelectric points as revealed by two-dimensional gel electrophoresis. These results imply that the precursor is N-glycosylated in the endoplasmic reticulum possibly without removal of the signal sequence and that the majority of acidic modifications are added late in the post-translational pathway.
Which skills really matter? proving face, content, and construct validity for a commercial robotic simulator.

A novel computer simulator is now commercially available for robotic surgery using the da Vinci® System (Intuitive Surgical, Sunnyvale, CA). Initial investigations into its utility have been limited due to a lack of understanding of which of the many provided skills modules and metrics are useful for evaluation. In addition, construct validity testing has been done using medical students as a “novice” group—a clinically irrelevant cohort given the complexity of robotic surgery. This study systematically evaluated the simulator’s skills tasks and metrics and established face, content, and construct validity using a relevant novice group. Expert surgeons deconstructed the task of performing robotic surgery into eight separate skills. The content of the 33 modules provided by the da Vinci Skills Simulator (Intuitive Surgical, Sunnyvale, CA) was then evaluated for these deconstructed skills and 8 of the 33 determined to be unique. These eight tasks were used for evaluating the performance of 46 surgeons and trainees on the simulator (25 novices, 8 intermediate, and 13 experts). Novice surgeons were general surgery and urology residents or practicing surgeons with clinical experience in open and laparoscopic surgery but limited exposure to robotics. Performance was measured using 85 metrics across all eight tasks. Face and content validity were confirmed using global rating scales. Of the 85 metrics provided by the simulator, 11 were found to be unique, and these were used for further analysis. Experts performed significantly better than novices in all eight tasks and for nearly every metric. Intermediates were inconsistently better than novices, with only four tasks showing a significant difference in performance. Intermediate and expert performance did not differ significantly. This study systematically determined the important modules and metrics on the da Vinci Skills Simulator and used them to demonstrate face, content, and construct validity with clinically relevant novice, intermediate, and expert groups. These data will be used to develop proficiency-based training programs on the simulator and to investigate predictive validity.
Teacher Perceptions and Observed Outcomes: An Ethnographic Study of Classroom Interactions.

The passage of PL 94-142 has led to provision of services for learning disabled students in the least restrictive environment (Council for Exceptional Children, 1976; Deno, 1976). Although information about the effects of mainstreaming is inconclusive (Gottlieb, 1981; Madden & Slavin, 1983), the mandate has necessitated an examination of the instructional methods commonly used in the regular classroom and their appropriateness for learning disabled pupils (Madden & Slavin, 1983). Jones, Jamieson, Moulin, and Towner (1981) pointed out that school personnel attitudes are an important key to student success in the mainstreamed setting. Thus, interactions between teachers and students, for example, are significant when defining the teacher-learning process as they help shape both teacher perceptions and teacher expectations of student behavior (Banks, 1981; Brophy & Good, 1974; Erickson, 1976; Mehan, 1979). Ethnographic studies conducted in the schools have begun to open up new perspectives of the classroom. An ethnomethodological approach to research is based on the assumption that interactional patterns reveal the social structure of educational activities which, in turn, determine "social facts" such as achievement (Bremme, 1976; Garfinkel, 1967; Mehan, 1979). In the last decade ethnographic studies carried out in schools have yielded a variety of linguistic, psychological, sociological, and anthropological approaches to interpreting classroom interaction (Cole, 1974; McDermott & Gospodinoff, 1979; Mehan, 1979; Moll, Estrada, Diaz & Lopes, 1980). None of these studies have dealt with the interaction of learning disabled students in the regular classroom. The present study represents an attempt to explore the nature of teacher interactions with a group of learning disabled students in a mainstreamed setting. A microethnographic approach was used to arrive at a critical analysis of the dynamics which may contribute to student success or failure in the classroom. The main issues considered were: (a) use of direct instructional time; (b) comparison between the instructional strategies advocated by the teacher and those observed; and (c) comparison between the teacher's perceptions of the students and their progress and the observed realities.
South Korean women at work: gender wage differentials by age, 1988–1998

Earning differences between South Korean women and men were compared to better understand how gender differences in wages have changed between 1988 and 1998 for five age groups. Utilizing labor market data from Korea's Occupational Wage Survey (OWS) for the years 1988 and 1998, we found that men enjoy a wage advantage over women in all age groups in both time periods. For all but the oldest group (55 and over), such bias was less in 1998 than in 1988. As hypothesized, the wage gap was narrower among younger age groups compared with older ones.
The liquid film and the core region velocity profiles in annular two-phase flow

Abstract Film flow data from complete data sets (i.e. those which have pressure gradient, film thickness and film flowrate) have been compared with three velocity profile correlations from the literature. The double velocity profile method was found to best represent the data. Velocity profile data in the core region of low-pressure air/water dispersed annular two-phase flow have been successfully correlated. A logarithmic law has been developed by making all calculations relative to the liquid film/gas core interface. The nondimensional velocity profile depends explicitly on the nondimensional distance from the interface, the entrainment and the nondimensional film thickness. The correlation correctly models the “laminarization” of the velocity profile with changing flow conditions. Qualitative comparisons are made with high-pressure steam/water two-phase flow velocity profile data.
Reversal of megaduodenum and duodenal dysmotility associated with improvement in nutritional status in primary anorexia nervosa

Anorexia nervosa is considered one type of eating disorder that may result in severe malnutrition. Patients with this disorder commonly complain of postprandial nausea, abdominal pain, and distension. We describe the radiologic and motility abnormalities associated with anorexia nervosa in a 21-year-old female. Barium gastrointestinal series demonstrated marked dilation of the duodenum, with prolongation of intestinal transit. A 4-hr fasting gastroduodenal motility study showed no propagating migrating motor complexes (MMC). Prolonged, but nonpropagating, bursts of high-amplitude phasic and tonic contractions were seen in the duodenum. In contrast, antral contractions were of low amplitude and esophageal motor function was normal. Metoclopramide and edrophonium caused an increase in gastroduodenal motor activity, but increased contractions were not associated with symptoms. Following a renutrition program that raised the patient's weight from 64 to 80% of her ideal body weight, the radiographic abnormalities and gastrointestinal dysmotility resolved completely. These observations suggest that anorexia-associated gastrointestinal motor dysfunctions are a consequence, not the cause of the generalized protein-calorie malnutrition associated with anorexia nervosa. The facts that motility in different parts of the gut is affected to different degrees and that gastric and duodenal muscle responds normally to exogenous stimulation argue against a generalized myogenic dysfunction and, rather, point to a reversible dysfunction of neural regulation.
Discriminative stimulus effects of morphine: central versus peripheral training.

While it is well known that rats can discriminate a peripheral injection of morphine from a saline injection, to our knowledge no one has trained rats to discriminate a direct brain-site injection of morphine from saline. In the present series of studies, one group of rats was trained to discriminate morphine (0.3 microgram) from saline injected into the perifornical area of the hypothalamus (PFA), a process that took rats about 37 sessions to learn. A dose response generalization curve for PFA-injected morphine (0.01, 0.03, 0.1, and 0.17 microgram) was generated in which the two highest doses of morphine generalized to the morphine-appropriate training stimulus. Intraperitoneal (i.p.) injection of 3 mg/kg, but not 1 mg/kg morphine, resulted in morphine-appropriate responding in the PFA morphine-trained rats. A second group of rats was trained to discriminate i.p. injections of 3 mg/kg morphine from injections of saline. A dose-response generalization test for i.p.-injected morphine (0.3, 0.56, 1.0, and 1.7 mg/kg) was conducted in which the 0.17 mg/kg dose of morphine generalized to the morphine-appropriate training stimulus. Generalization tests using PFA-injected morphine doses (0.17, 0.56, 1.0, and 3.0 microgram) failed to result in morphine-appropriate responding in the i.p. morphine-trained rats. Naloxone administered into the PFA (50 microgram) or the periphery (3 mg/kg, i.p.) blocked morphine discrimination in the PFA-trained rats. However, when naloxone was injected into the PFA (50 microgram) together with i.p. morphine (3 mg/kg) in animals trained using i.p. injections, the antagonist failed to block morphine-appropriate responding. Thus, while peripheral injection of morphine generalized to the discriminative stimulus effects of morphine produced under PFA-injection training, the opposite effects were not noted.
Elaboration of Diaryl Ketones into Naphthalenes Fused on Two or Four Sides: A Naphthoannulation Procedure

Transition metal-catalyzed double ring closures of 1,1-diaryl-2,2-diethynylethylenes yield polycyclic aromatic hydrocarbons and heterocycles that contain a newly formed naphthalene ring system embedded in a larger polycyclic network. The diynes required for this procedure are readily synthesized from diaryl ketones by the Corey-Fuchs olefination and subsequent Sonogashira coupling with trimethylsilylacetylene followed by desilylation. This procedure provides easy access to new compounds such as 3,11-di-tert-butyl[4]helicene and 1,8,9-perinaphthothioxanthene. Double naphthoannulation of 9,10-anthraquinone by this procedure closes four new benzene rings in a single operation to give coronene, although the yield in this case is presently low.
Chunks as interference units in free recall

The experiment tested the hypothesis that free recall is limited by the number of chunks that can be reproduced, not the number of words. Recall of a given word should be higher the fewer chunks are required to encompass the remaining words in the list. To test this, a subset of 12 critical words was embedded in a larger list containing 12 fillers composed either of single words, or three-word cliches, or unrelated word triplets. As predicted, recall of the critical words was the same in the single-word and cliche lists, but poorer in the triplet list. Cliches and single words were equally recalled. Total units recalled in the three lists were the same, with only the selection of units differing in recall. The results confirm the chunking hypothesis and have implications for Murdock's (1960) total-time hypothesis about free recall.
Planetary rotation and invertebrate skeletal patterns: Prospects for extant taxa

It has been two decades since Wells proposed that the duration of absolute geologic time could be estimated using growth patterns found in fossil corals. Since then, the temporal and environmental records encoded in the accretionary skeletons of other invertebrates also have been studied. Although extensive research on the significance of skeletal patterns has been done on bivalved molluscs, other taxa such as the brachiopods, bryozoans, cephalopods and echinoderms are in need of further study. For two taxa, the nautiloids and brachiopods, additional growth pattern data are presented here. These data indicate that erroneous geophysical conclusions about the length of the synodic lunar month were previously reached using what now appear to be unfounded assumptions about the temporal significance of their growth patterns. Assumptions regarding the temporal and environmental information contained in the skeletons of these poorly studied taxa need to be replaced by more extensive analyses using standardized techniques. Only then will we arrive at correct conclusions about the dynamical history of the Earth-Moon system.
Surgical Management of Pulmonary Metastases

Metastasectomy is the only curative option for some patients with secondary pulmonary malignancy. Many studies suggest a survival benefit in selected patients if complete resection of pulmonary metastases is accomplished. There are several operative approaches that may be used, with the goal of complete resection and with minimal parenchymal loss. Evaluation for resection must include ascertainment of control of the primary tumor and assessment of the ability to achieve complete resection. Minimally invasive approaches may offer advantages in quality of life outcomes, with equivalent oncologic outcomes.