cssi/SciSciGPT-SciSciNet huggingface dataset:
Optical coatings in microscale channels by atomic layer deposition.

High-aspect-ratio channels may be coated using atomic layer deposition (ALD) due to the unique self-limiting nature of the process, and this has been often demonstrated using deep reactive-ion etched trenches in silicon. However, for optical and microfluidic applications, many channels are centimeters deep with diameters of tens to hundreds of micrometers, and the relatively large area exposes more difficult problems of temperature and gas flow uniformity. To quantify the uniformity of optical coatings deposited by ALD under those conditions, an air wedge has been created between two square wafers of silicon approximately 7 cm on a side, with the air gap varying linearly from 0-1560 μm. ALD aluminum oxide uniformity is astounding, while hafnium oxide shows a need for process optimization, but still exceeds the capability observed in other deposition techniques. A six-layer Fabry-Perot optical cavity with fixed 500 nm resonance was deposited inside a wedge, and the measured resonant wavelength closely matched predictions, except at the deepest regions of the wedge.
In situ characterization of phytoplankton from vertical profiles of fluorescence emission spectra

Vertical profiling of the upper ocean with a laser/fiber optic fluorometer enabled the determination of fluorescence emission spectra of photosynthetic pigments over small vertical scales. Simultaneous acquisition of phycoerythrin (PE) and chlorophyll (chl) emission spectra allowed in situ differentiation between PE-containing cells (cryptomonads and cyanobacteria) and other chl-containing autotrophs. Further, fluorescence spectral peak shifts associated with different species of PE-containing cells resulted in even finer scale in situ taxonomic differentiation. We found that the phycoerythrin fluorescence emission maxima shifted from 578 nm near the surface, to 585 μm at the base of the shallow thermocline (30% light level), and to 590 nm below the thermocline at the base of the euphotic zone (1% light level). These shifts in peak emission coincided with a taxonomic change in the PE-containing cells (as determined from analysis of discrete bottle samples) from a greater proportion of Synechococcus spp. in the upper water column to a greater proportion of cryptomonads at the base of the euphotic zone. These results indicate that the composition of the phytoplankton assemblage may be assessed in situ without sample collection.
A Theory of Middle Ear Muscle Function at Moderate Sound Levels

The minor amplitude modulations of auditory input, which are introduced by the middle ear muscle acoustic reflex at moderate and low sound intensities in the cat, may contribute significantly to signal analysis or attention mechanisms of the auditory system.
The Ontology of Science: An Essay towards a Complete Description of the Universe

L'A. propose une ontologie moniste fondee sur le concept d'" energie-idee ". Il vise a fournir une conception unifiee de l'univers qui depasse les divergences scientifiques a partir de bases metaphysiques
Changes in Polysomes of Black Locust Seedlings during Dehydration‐Rehydration Cycles

Net assimilation, dark respiration and xylem pressure potential were followed through dehydration-rehydration cycles in black locust seedlings (Robinia pseudoacacia L.). Sucrose gradient profiles indicated the retention of polysomes during stress. RNase activity declined during dehydration but returned to pre-stress levels upon irrigation. Comparisons of black locust and corn polysomes during water stress are made.
On the Role of Small Amines in Zeolite Synthesis

A systematic study explored the ability of small amines to control the zeolites obtained at the high-pH levels typical of crystallizations at SiO2/Al2O3 ratios between 20 and 40. Experiments in the absence of amine showed that mordenite (MOR) was the preferred product at the lowest ratio, and ZSM-5 was the preferred product at the highest SiO2/Al2O3 ratio. However, the addition of C2-, C3-, and C4-alkylamines changed the product dramatically. On addition of ethylamine, ZSM-5 was produced at the lowest SiO2/Al2O3 ratio, and ZSM-35 was the preferred product with C3- and C4-amines. On addition of the largest of the group, tert-butylamine, the product reverted to MOR. With polyamines such as diethylenetriamine and triethylenetetramine, ZSM-5 samples were produced having framework SiO2/Al2O3 ratios below 20. The hexane cracking activity of these samples was consistent with their exceptionally high Al content. The cyclic C4- to C6-amines, at both SiO2/Al2O3 extremes, yielded ZSM-35 and MCM-22. Again, with the l...
Transposon Insertions in the Flavobacterium johnsoniae ftsX Gene Disrupt Gliding Motility and Cell Division

Flavobacterium johnsoniae is a gram-negative bacterium that exhibits gliding motility. To determine the mechanism of flavobacterial gliding motility, we isolated 33 nongliding mutants by Tn4351 mutagenesis. Seventeen of these mutants exhibited filamentous cell morphology. The region of DNA surrounding the transposon insertion in the filamentous mutant CJ101-207 was cloned and sequenced. The transposon was inserted in a gene that was similar to Escherichia coli ftsX. Two of the remaining 16 filamentous mutants also carried insertions in ftsX. Introduction of the wild-type F. johnsoniae ftsX gene restored motility and normal cell morphology to each of the three ftsX mutants. CJ101-207 appears to be blocked at a late stage of cell division, since the filaments produced cross walls but cells failed to separate. In E. coli, FtsX is thought to function with FtsE in translocating proteins involved in potassium transport, and perhaps proteins involved in cell division, into the cytoplasmic membrane. Mutations in F. johnsoniae ftsX may prevent translocation of proteins involved in cell division and proteins involved in gliding motility into the cytoplasmic membrane, thus resulting in defects in both processes. Alternatively, the loss of gliding motility may be an indirect result of the defect in cell division. The inability to complete cell division may alter the cell architecture and disrupt gliding motility by preventing the synthesis, assembly, or functioning of the motility apparatus.
Sputtering properties of tungsten ‘fuzzy’ surfaces

Abstract Sputtering yields of He-induced W ‘fuzzy’ surfaces bombarded by Ar have been measured in the linear divertor plasma simulator PISCES-B. It is found that the sputtering yield of a fuzzy surface, Y fuzzy , decreases with increasing fuzzy layer thickness, L , and saturates at ∼10% of that of a smooth surface, Y smooth , at L > 1 μm. The reduction in the sputtering yield is suspected to be due mainly to the porous structure of fuzz, since the ratio, Y fuzzy / Y smooth follows (1 − p fuzz ), where p fuzz is the fuzz porosity. Further, Y fuzzy / Y smooth is observed to increase with incident ion energy, E i . This may be explained by an energy dependent change in the angular distribution of sputtered W atoms, since at lower E i , the angular distribution is observed to become more butterfly-shaped. That is, a larger fraction of sputtered W atoms can line-of-sight deposit/stick onto neighboring fuzz nanostructures for lower E i butterfly distributions, resulting in lower ratio of Y fuzzy / Y smooth .
BINDING PREFERENCES OF THE TRIBENZYLIDENEMETHANE LIGAND IN HIGH-OXIDATION-STATE TANTALUM COMPLEXES

Reaction of Li2(TBM)(TMEDA)2 (TBM = tribenzylidenemethane) with TaMe3Cl2 gives (TBM)TaMe3 (1) in 44% yield. Structural characterization of the (tert-Bu-TBM)TaMe3 derivative 2 shows an eclipsed orie...
Chromatin assembled in the presence of cytosine arabinoside has a short nucleosome repeat

Incubation of MSB cells with cytosine arabinoside (1-beta-D-arabinofuranosylcytosine, ara-C) inhibits 3H-thymidine incorporation into nascent DNA while nucleosome core histone synthesis proceeds in molar stoichiometry at about 20% of control rates. The excess nascent histone is incorporated into chromatin and nucleosome cores are assembled normally on the small amount of DNA which is synthesized at submaximal levels of ara-C. This DNA becomes packaged into a shortened nucleosome repeat, however. These results indicate that the nucleosome core is a strongly conserved unit of chromatin replication and suggest that the stoichiometry of nascent histone to DNA may be one factor influencing the establishment of the nucleosome repeat length. It cannot be the only factor, however, since the closely packed nucleosomes made in the presence of ara-C begin to return to their normal spacing within six hours after reversal.
Effects of prolactin on water balance and kidney function in bullfrog tadpoles.

In four experiments of similar design, stage III–XII bullfrog tadpoles were treated for 5–13 days with either 10 μg/day ovine prolactin (PRL) or 10 μl/day saline (0.7% NaCl). In all cases, saline-treated tadpoles lost ca. 10% of their body weight, whereas PRL-treated animals either maintained their weight or gained slightly. Compared with controls, PRL-treated tadpoles showed a significantly higher water content and a 10–20% increase in inulin space (= extracellular volume). PRL treatment also significantly decreased plasma [Na+] (but not total extracellular [Na+]), and the rates of renal inulin clearance (= glomerular filtration rate) and urine production. PRL-treated tadpoles showed significant retention of the water taken up in response to a salt load. These data suggest that the PRL-induced weight gain observed in bullfrog tadpoles is accompanied by major changes in renal function and the size, water content, and sodium concentration of the extracellular fluid compartment.
Imaging of Right Coronary Artery Ostial Stents by Transesophageal Echocardiography

A 55-year-old female with a history of rheumatic mitral stenosis and coronary artery disease underwent a transesophageal echocardiographic examination to assess the feasibility of performing balloon mitral valvuloplasty. During the examination, an unusual echodensity was incidentally discovered in the right sinus of Valsalva which represented a coronary artery stent. Transesophageal imaging of ostial stents have rarely been described in the literature. Their characteristic echocardiographic findings are discussed.
Intelligent image analysis for image-guided hair removal and skin therapy

We present the development of advanced automatic target recognition (ATR) algorithms for the hair follicles identification in digital skin images to accurately direct the laser beam to remove the hair. The ATR system first performs a wavelet filtering to enhance the contrast of the hair features in the image. The system then extracts the unique features of the targets and sends the features to an Adaboost based classifier for training and recognition operations. The ATR system automatically classifies the hair, moles, or other skin lesion and provides the accurate coordinates of the intended hair follicle locations. The coordinates can be used to guide a scanning laser to focus energy only on the hair follicles. The intended benefit would be to protect the skin from unwanted laser exposure and to provide more effective skin therapy.
P, T, $$f_{{\text{CO}}_{\text{2}} }$$ and $$f_{{\text{H}}_{\text{2}} {\text{O}}}$$ during metamorphism of calcareous sediments in the Waterville-Vassalboro area, south-central Maine

In a regional metamorphic terrain where six isograds have been mapped based on mineral reactions that are observed in metacarbonate rocks, the P-T conditions and fugacities of CO2 and H2O during metamorphism were quantified by calculations involving actual mineral compositions and experimental data. Pressure during metamorphism was near 3,500 bars. Metamorphic temperatures ranged from 380° C (biotite-chlorite isograd) to 520° C (diopside isograd). $$f_{{\text{CO}}_{\text{2}} }$$ and $$f_{{\text{CO}}_{\text{2}} }$$ / $$f_{{\text{H}}_{\text{2}} {\text{O}}}$$ in general is higher in metacarbonate rocks below the zoisite isograd than in those above the zoisite isograd. Calculated $$f_{{\text{CO}}_{\text{2}} }$$ and $$f_{{\text{H}}_{\text{2}} {\text{O}}}$$ are consistent with carbonate rocks above the zoisite isograd having equilibrated during metamorphism with a bulk supercritical fluid in which $$P_{{\text{CO}}_{\text{2}} }$$ + $$P_{{\text{H}}_{\text{2}} {\text{O}}}$$ = P total. Calculations indicate that below the zoisite isograd, however, $$P_{{\text{CO}}_{\text{2}} }$$ + $$P_{{\text{H}}_{\text{2}} {\text{O}}}$$ was less than Ptotal, and that this condition is not due to the presence of significant amounts of species other than CO2 and H2O in the system C-O-H-S. Calculated $$P_{{\text{CO}}_{\text{2}} }$$ /( $$P_{{\text{CO}}_{\text{2}} }$$ + $$P_{{\text{H}}_{\text{2}} {\text{O}}}$$ ) is low (0.06–0.32) above the zoisite isograd. The differences in conditions above and below the zoisite isograd may indicate that the formation of zoisite records the introduction of a bulk supercritical H2O-rich fluid into the metacarbonates. The results of the study indicate that $$f_{{\text{CO}}_{\text{2}} }$$ and $$f_{{\text{H}}_{\text{2}} {\text{O}}}$$ are constant on a thin section scale, but that gradients in $$f_{{\text{CO}}_{\text{2}} }$$ and $$f_{{\text{H}}_{\text{2}} {\text{O}}}$$ existed during metamorphism on both outcrop and regional scales.
Transport properties of a one-dimensional two-component quantum liquid with hyperbolic interactions.

We present an investigation of the sinh-cosh (SC) interaction model with twisted boundary conditions. We argue that, when unlike particles repel, the SC model may be usefully viewed as a Heisenberg-Ising fluid with moving Heisenberg-Ising spins. We derive the Luttinger-liquid relation for the stiffness and the susceptibility, both from conformal arguments, and directly from the integral equations. Finally, we investigate the opening and closing of the ground-state gaps for both SC and Heisenberg-Ising models, as the interaction strength is varied.
Aluminated Derivatives of Porous Clay Heterostructures (PCH) Assembled from Synthetic Saponite Clay: Properties as Supermicroporous to Small Mesoporous Acid Catalysts

Mesostructured aluminosilicate intercalates belonging to the new class of solid acids known as porous clay heterostructures (PCH) have been prepared by the postsynthesis grafting of aluminum into the mesostructured intragallery silica framework of a PCH precursor derived from a synthetic saponite clay. Elemental analyses, powder X-ray diffraction, N2 adsorption, and 27Al MAS NMR spectroscopy were used to characterize the reaction products, which we designate Al−SAP/PCH. Depending on the choice of aluminum reagent (AlCl3 or NaAlO2), the Al−SAP/PCH derivatives exhibited basal spacings of 32−34.8 A, BET surface areas of 623−906 m2/g, pore volumes of 0.32−0.45 cm3/g, and pore sizes in the large micropore to small mesopore range (14−25 A). The aluminum content was strongly correlated with the Si/Al stoichiometry of the postsynthesis reaction mixture. Nearly all of the grafted aluminum was incorporated into tetrahedral sites in the intragallery silica framework. In comparison to the initial silica-intercalated ...
SENSORY EVALUATION OF COOK/CHILLED PRODUCTS REHEATED BY CONDUCTION, CONVECTION AND MICROWAVE RADIATIONa,b

Precooked slices of beef loaf, peas and potatoes were reheated individually or together as a meal by conduction, convection or microwave radiation. At point of service, products were compared for visual appeal and other sensory qualities by 12 taste panelists during four laboratory replications of a simulated hospital cook/chill foodservice system. Time and temperature measurements of food handling as well as moisture content and Hunter Color values of experimental products were also monitored. Best food temperature control was obtained after microwave reheating. When the experimental products were reheated as meals, panelists rated the food prepared in the conduction subsystem highest for sensory quality. Although differences in moisture of slices of beef loaf individually reheated were undetected by panelists, objective measurements generally indicated that microwave reheated products had the lowest moisture content. Under full load conditions, conduction reheat is recommended to optimize visual appeal and other sensory qualities of meals served in hospital cook/chill foodservice systems.
Optimizing the Delivery of Radiation Therapy to Cancer Patients

In the field of radiation therapy, much of the research is aimed at developing new and innovative techniques for treating cancer patients with radiation. In recent years, new treatment machines have been developed that provide a much greater degree of computer control than was available with the machines of previous generations. One innovation has been the development of an approach called "tomotherapy.'' Tomotherapy can be defined as computer-controlled rotational radiotherapy delivered using an intensity-modulated fan beam of radiation. The successful implementation of the new delivery techniques requires the development of a suitable approach for optimizing each patient's treatment plan. One of the challenges is to quantify optimality in radiation therapy. We have tested a variety of objective functions and constraints in pursuit of a formulation that performs well for a wide variety of disease sites. An additional challenge stems from the sizable amount of data and the large number of variables that are involved in each optimization. This paper presents several approaches to optimizing treatment plans in radiation therapy, and the advantages and disadvantages of a number of formulations are explored.
Integration of a fish bioenergetics model into a spatially explicit water quality model: Application to menhaden in Chesapeake Bay

Although fish are usually thought of as victims of water quality degradation, it has been proposed that some planktivorous species may improve water quality through consumption of algae and sequestering of nutrients via growth. Within most numerical water quality models, the highest trophic level modeled explicitly is zooplankton, prohibiting an investigation of the effect a fish species may be having on its environment. Conversely, numerical models of fish consumption do not typically include feedback mechanisms to capture the effects of fish on primary production and nutrient recycling. In the present study, a fish bioenergetics model is incorporated into CE-QUAL-ICM, a spatially explicit eutrophication model. In addition to fish consumption of algae, zooplankton, and detritus, fish biomass accumulation and nutrient recycling to the water column are explicitly accounted for. These developments advance prior modeling efforts of the impact of fish on water quality, many of which are based on integrated estimates over an entire system and which omit the feedback the fish have through nutrient recycling and excretion. To validate the developments, a pilot application was undertaken for Atlantic menhaden (Brevoortia tyrannus) in Chesapeake Bay. The model indicates menhaden may reduce the algal biomass while simultaneously increasing primary productivity.
Projection of the auditory nerve to the medial vestibular nucleus.

Abstract Degeneration studies of the auditory nerve and intracochlear placement of horseradish peroxidase (HRP) were used to map the central projections of the spiral ganglion. These studies revealed that the descending branches of the auditory nerve, in addition to terminating in the cochlear nuclei, also project to the caudal half of the ipsilateral medial vestibular nucleus. The origin of this pathway in the spiral ganglion was confirmed by retrograde labeling of ganglion cells after HRP implants in the medial vestibular nucleus.
Cross-Talk between the T Cell Antigen Receptor and the Glucocorticoid Receptor Regulates Thymocyte Development

The fate of an immature thymocyte, life or death, is largely determined by the ligand-specificity of its T cell antigen receptor (TCR). The default pathway for thymocytes bearing TCRs with subthreshold avidity for self-antigens is death (death by neglect). Thymocytes bearing TCRs with high avidity for self also undergo apoptosis (negative selection). Those thymocytes with intermediate avidities, or that perhaps recognize self-peptides that have partial agonist or antagonist properties, survive and differentiate into mature immunocompetent T cells (positive selection). How TCR avidity is interpreted as a "rescue" signal or a death signal is unknown. Based upon a T cell hybridoma model, our laboratory proposed that glucocorticoids, which themselves are potent inducers of thymocyte apoptosis, antagonize TCR-mediated thymocyte deletion and allow positive selection to occur. In fact, epithelial cells in the thymus proved to be a source of steroid production, and interference with steroid synthesis in fetal thymic organ culture resulted in a greatly enhanced sensitivity of thymocytes to TCR-mediated apoptosis. Transgenic mice with reduced glucocorticoid receptor (GR) levels were produced by tissue-specific expression of GR antisense. Thymocytes in these mice had high levels of spontaneous apoptosis, and were exquisitely sensitive to deletion induced by cross-linking the TCR. Moreover, there was a very large (> or = 90%) loss of CD4+CD8+ thymocytes, signifying a block at the CD4-CD8- to CD4+CD8+ transition, perhaps due to apoptosis of cells upon engagement of the pre-TCR in the absence of an antagonizing glucocorticoid stimulus. The molecular mechanism of the antagonism is currently being investigated. These data indicate that there is cross-talk in thymocytes between the TCR and glucocorticoid signaling pathways resulting in apoptosis, and that locally produced steroids, in a paracrine fashion, participate in setting the TCR avidity thresholds that determine whether developing thymocytes survive or die, and therefore help to mold the antigen-specific T cell repertoire.
Structure of the terdiurnal tide at 95 km

Satellite wind observations from the High Resolution Doppler Interferometer (HRDI) instrument on the Upper Atmosphere Research Satellite (UARS) are used to describe the latitudinal structure and seasonal variation of the terdiurnal (8 hour) atmospheric tide at 95 km. The amplitude of the annual average tide is 5 m/s (meridional) and 15 m/s (zonal). Within the range observed (60°S to 60°N), the maximum amplitudes are found during fall and winter at midlatitudes. Only weak temporal correlations with the diurnal and semidiurnal tides are seen on the monthly time scales resolved.
A UNIVARIATE MEASUREMENT ERROR MODEL FOR LONGITUDINAL CHANGE

Analyses of variables measured with error are often flawed when measurement error is ignored. An extensive literature on linear measurement error models is available by [1], and more recently, for non-linear measurement error models by [2] and [3]. We investigate problems encountered in the analysis of longitudinal change, where the difference in some outcome variable is modeled on a set of regressor variables in a linear regression model. This type of analysis has become quite popular in biomedical research, and the results are often biased when the outcome variable is measured with error and its observed baseline value is included as a covariate in the fitted model. [4] demonstrated the effects of measurement error in the analysis of change in wall thickness of the common carotid artery. They showed the naive analysis led to erroneous findings due to the measurement error bias, even when the regressor variables were assumed to be measured precisely. In this paper, we present a method-of-moments correcti...
A quantitative cytochemical analysis of large antral follicles in two types of rat polycystic ovaries

Ovaries from normal mature rats, rats injected with testosterone propionate (TP), and from aged rats were removed, and large antral follicles examined by quantitative cytochemical techniques in order to analyze possible enzymatic defects that relate to follicular steroidogenesis. The ovaries from the TP-injected and the aged rats were polycystic. Lipid deposition was analyzed in frozen sections stained with Sudan black. A microdensitometer was used to measure delta 5-3 beta-hydroxysteroid dehydrogenase (3 beta OHD) activity and G-6-PD type IH generation in the theca, and in peripheral region, antral region, and corona radiata of large antral follicles. 3 beta OHD is the enzyme that converts pregnenolone to progesterone. Type IH generation is related to the conversion of androstenedione to estradiol. Lipid droplet deposition was comparable in the three types of follicles. Compared to that in normal preovulatory follicles, 3 beta OHD activity was similar in identical regions of large antral follicles in TP-injected rats, but less in the theca and peripheral region of the membrana granulosa of the aged rat. G-6-PD type IH generation was less in the peripheral region of large antral follicles of both TP-injected and aged rats than in preovulatory follicles. Type IH generation was also less in the theca of TP-injected rats than in the theca of normal rats. This study provides evidence that in spite of their normal appearance, large antral follicles in polycystic ovaries are not physiologically sound. Furthermore, the enzymatic disturbance appears to be different in different types of polycystic ovaries.
The Politics of Watershed Policymaking

In 1996, we began a study of contrasting efforts to restore and enhance watershed health in three different river basins. While we were organizing our study, one of the watershed groups that we were examining “fell apart,” therebey providing us with an unusual opportunity of study the difference between organizational success and failure. Obviously there are many problems in brawing broad conciusions from the study of a few cases, and we are well aware of those limits. Nonetheless, this paper's focus is on what can be learned about this failed attempt at watershed planning and organizing. We do this by combining descriptive case materials and evidence drawn from surveys of participating members of watershed organizations. We first describe the gerneral challenges to watershed policymaking. Second, with a focus on the decline of wild salmon in the Pacific Nortwest, including California, we briefly characterize our case studies of watershed organization that exist in three river systems—the Yakima River (in cenral Washington) and the Santa Ynez and Sacramento Rivers in California. In both of these stes, watershed organizations are the primary architects of watershed policymaking. Third, we present an analysis of survey results, emphasizing a search for whether the views of participants in the “failing” case of watershed organization differ from those of participants in the ongoing cases.
Factors affecting hyporheic and surface transient storage in a western U.S. river

Summary Hyporheic storage accounts for a significant fraction of solute residence time in small streams and has been shown to have a large effect on the transport of solutes. It is not clear whether this characteristic is preserved in larger streams and rivers, as increased discharge and decreased slope may reduce overall exchange between the channel and subsurface, and the size of surface storage zones may increase. Conservative tracer tests conducted in the Truckee River, a stream with mean annual discharge >0.5 m3 s−1, were simulated with both one (1-SZ) and two-storage zone (2-SZ) transport models to quantify the relative role of surface transient storage (STS) and hyporheic transient storage (HTS) on the physical transport of solutes in a large stream. Tracer injections were conducted at two different discharge levels in two reaches with distinct geomorphic characteristics. STS was the dominant storage mechanism for all reaches and discharge levels and surface storage accounted for a larger fraction of median transport time ( F MED 200 ) than hyporheic storage in all but one case. Increased discharge significantly reduced the influence of the HTS (primarily) and STS zones on median transport time at the study site. Comparisons with studies of discharge and geomorphic effects on TS characteristics in other streams indicated differing physical controls on STS and HTS zones. Therefore, measurements such as slope, sinuosity, width, depth, and gross gains and losses of discharge need to be considered along with discharge. This work adds to the growing sentiment that up-scaling and prediction of stream storage characteristics based on discharge and channel properties is far from straightforward. Since biogeochemical processing occurs differently in the HTS and STS, two-zone storage models provide necessary representations of transport in river systems for studies focused on aspects of water quality. Extra parameters are required for model optimization but simple cross-section surveys (area and velocity) provide enough information to ensure enhanced parameter reliability.
Physics of turbulence generation and sustenance in a boundary layer

Abstract In this paper, a systematic report of our recent DNS study on physics of late boundary layer transition is presented. This includes mechanism of the large coherent vortex structure formation, small length scale generation and flow chaos. First, it is not appropriate to call the turbulent flow as a “random” motion since the conservation law of mass, momentum and energy must be satisfied. Turbulence is built up by organized “vortex packets” which can be accepted by Navier–Stokes equations. Second, the linearly unstable modes are important, but the role of these modes is only to trigger the vorticity rollup. They cannot form the vortex by themselves and cannot cause the flow transition directly. The flow transition is mainly an inherent property of fluid flow, which shows that fluids cannot tolerate shear and shear must transfer to rotation when Reynolds number is large. The commonly accepted concept that “Lambda vortex self-deforms to hairpin vortex” does not exist. Finally, the widely spread concept “vortex breakdown to turbulence”, which was considered as the last stage of flow transition, is not observed. We proposed a new mechanism about turbulence generation and sustenance, that all small length scales (turbulence) are generated by shear layer instability produced by large vortex structure with multiple level vortex rings, multiple level sweeps and ejections, and multiple level negative and positive spikes near the laminar sub-layers. Therefore, “turbulence” is not generated by “vortex breakdown” but rather positive and negative spikes and consequent high-shear layers. “Shear layer instability” is considered as the “mother of turbulence”. This new mechanism may give a universal mechanism for turbulence generation and sustenance – the energy is brought by large vortex structure through multiple level sweeps not by “vortex breakdown”. Fluid shear, which is dominant in laminar boundary layer, is conditionally unstable but fluid rotation, which is dominant in turbulent boundary layer, is stable. In other words, the laminar boundary layer is an unstable state, but the turbulent is a stable state, and thus transition from laminar to turbulent is doomed when the Reynolds number is large enough. We prefer to present new stages to describe the boundary layer transition with five steps, i.e. perturbation (may include receptivity and linear instability), vorticity rollup, large vortex formation, small length scale generation, loss of symmetry and becoming chaotic to turbulence.
Improving PET receptor binding estimates from Logan plots using principal component analysis

This work reports a principal component analysis (PCA)-based approach for reducing bias in distribution volume ratio (DVR) estimates from Logan plots in positron emission tomography (PET). Comparison has been made of all existing bias-removal methods with the proposed PCA method, for both single-estimate PET studies and intervention studies where pre- and post-intervention estimates are made. Bias in Logan-based DVR estimates is because of the noise in the PET time-activity curves (TACs) that propagates as correlated errors in dependent and independent variables of the Logan equation. Intervention studies show this same bias but also higher variance in DVR estimates. In this work, noise in the TACs was reduced by fitting the curves to a low-dimension PCA-based linear model, leading to reduced bias and variance in DVR. For validating the approach, TACs with realistic noise were simulated for a 11C-labeled tracer with carfentanil (CFN)-like kinetics for both single-measurement and intervention studies. Principal component analysis and existing methods were applied to the simulated data and their performance was compared by statistical analysis. The results indicated that existing methods either removed only part of the bias or reduced bias at the expense of precision. The proposed method removed approximately 90% of the bias while also improving precision in both single- and dual-measurement simulations. After validation of the proposed method in simulations, PCA, along with the existing methods, was applied to human [11C]CFN data acquired for both single estimation of DVR and dual-estimation intervention studies. Similar results were observed in human scans as were seen in the simulation studies.
Racial Differences in Graduation Rates From Adult Drug Treatment Courts

Drug courts have demonstrated promise as an intervention that is effective in reducing recidivism and thereby providing a viable alternative to incarceration for drug-involved offenders. Despite their promise, it is not clear that African Americans are as likely to have positive outcomes in drug courts as other clients. This article reviews recent research on racial differences in completion of drug court and uses multivariate analysis to assess the impact of race on drug court graduation in a Midwestern jurisdiction. We find evidence that race may interact with psychological distress to reduce the likelihood of graduation for African American clients.
“Big game” extinction caused by late Pleistocene climatic change: Irish elk (Megaloceros giganteus) in Ireland

Megaloceros giganteus, the largest Eurasian deer, inhabited Ireland from ca. 12,000 yr B.P. to the time of its extinction ca. 10,600 yr B.P. The archaeologic record documents that people arrived on the island no earlier than 9000 yr B.P., so they could not have caused the extinction in Ireland. Close stratigraphic association of the geologically youngest elk fossils with sediments indicating the onset of the Nahanagan Stadial (approximately = Younger Dryas) implicates climatic change as the exterminator. Palynologic data support the idea that extinction probably resulted when forage quantity and quality along with length of the spring green-up decreased during the Nahanagan Stadial. For M. giganteus, this meant that the energy intake required to sustain large bodies, grow enormous antlers, and build fat reserves for winter was increasingly difficult to maintain, until deaths, primarily by winterkill, outnumbered births.
Frederick W. Taylor'S 1899 Pig Iron Observations: Examining Fact, Fiction, And Lessons For The New Millennium

Taylor's pig iron observations at Bethlehem Iron in 1899 are often cited as an example of how scientific management helped increase industrial efficiency. The current research, relying almost exclu...
A 51-Year-Old Man With Acute Dyspnea and Leg Swelling

1. What are the patient’s most striking clinical, laboratory, and histopathologic findings? 2. How do you explain these findings? 3. What is the patient’s most likely diagnosis? 4. What is the most common causal organism for this patient’s disease? 5. What is the pathogenesis of this patient’s disease? 6. What is the appropriate treatment for this disease? 7. What are the complications and prognosis of this disease?
A critical evaluation of new agents for the treatment of sepsis.

Objective. —To evaluate new treatments directed against endotoxin, tumor necrosis factor α, and interleukin 1 for use in sepsis and related disorders (sepsis syndrome and septic shock). Data Sources. —Investigations of these treatments in animal models, healthy human volunteers, and patients with sepsis and related disorders. Study Selection. —Particular attention was paid to studies of patients with sepsis and related disorders, especially randomized, double-blind, controlled trials. Data Extraction. —Animal studies and investigations with human volunteers were judged by how closely the experimental model replicated the clinical disorder (sepsis). Patient trials were assessed by sample size and design. Results of all studies were used to evaluate the likelihood that a given treatment would reduce mortality. Data Synthesis. —Direct comparison of E5 and HA-1A antibody studies is difficult because of differences in their design, definitions of shock, and methods of subgroup analysis. However, both antibodies improve outcome in some subgroups: E5 benefits patients with gram-negative infection (bacteremic or focal) who do not have refractory shock, and HA-1A benefits those with gramnegative bacteremia (regardless of whether shock is present) but not those with focal gram-negative infection. Two agents that may be beneficial in gram-positive and gram-negative infection are monoclonal antibodies to tumor necrosis factor α and receptor antagonists to interleukin 1. Preliminary results with both are reviewed. Conclusions. —All three types of treatment may improve outcome in sepsis. The best results will probably be obtained with combination therapy that interrupts multiple points of the inflammatory cascade underlying sepsis. (JAMA. 1991;266:1686-1691)
Cognitive Effects of Statin Medications

The demonstrated benefits of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) for cardiovascular and cerebrovascular disease are well established in the medical literature, and this class of medications is among those most commonly prescribed in the USA. In 2012, the US Food and Drug Administration issued updated recommendations regarding statin medications, and the panel’s comments regarding memory impairment fostered clinical confusion (in part because of the lay media’s amplification). Cognitive data from several large epidemiological studies have not reliably demonstrated a robust association between incident cognitive impairment and statin use, with some studies reporting a protective effect, some reporting an increased risk and others finding no association. Although several interventional studies have evaluated statins as a possible adjunctive treatment for Alzheimer’s disease, none have clearly demonstrated a benefit. A small number of case series have reported infrequent memory difficulties associated with statin use. In these series, the patients’ cognitive symptoms resolved after statin discontinuation. The existing medical literature does not suggest that cognitive considerations should play a major role in medical decision making to prescribe statins for the large majority of patients. As with any medication prescribed for older adults, careful clinical monitoring for side effects should be exercised. If a patient is suspected of having idiosyncratic memory impairment associated with use of a statin medication, the drug can be discontinued. The patient should then be followed with careful clinical observation for 1–3 months for resolution of the cognitive symptoms.
Self-healing of surfactant surface micelles on millisecond time scales.

We study the dynamics of surfactant micelles at the solid−liquid interface using a new atomic force-microscopic imaging mode to visualize the nanometer-level structural features of the micelles and the picometer-level lattice of the substrate simultaneously. We find that defects created in a crystalline micellar array by the scanning probe tip self-heal flawlessly in less than 6 ms.
What do the software reliability growth model parameters represent

Here we investigate the underlying basis connecting the software reliability growth models to the software testing and debugging process. This is important for several reasons. First, if the parameters have an interpretation, then they constitute a metric for the software test process and the software under test. Secondly, it may be possible to estimate the parameters even before testing begins. These a priori values can serve as a check for the values computed at the beginning of testing, when the test-data is dominated by short term noise. They can also serve as initial estimates when iterative computations are used. Among the two-parameter models, the exponential model is characterized by its simplicity. Both its parameters have a simple interpretation. However, in some studies it has been found that the logarithmic Poisson model has superior predictive capability. Here we present a new interpretation for the logarithmic model parameters. The problem of a priori parameter estimation is considered using actual data available. Use of the results obtained is illustrated using examples. Variability of the parameters with the testing process is examined.
The transit system, 1977: performance, plans and potential

The precision of the Transit System is described since the introduction of the software improvements in 1975. The surveyor’s rather than the navigator9s use of Transit is emphasized. The differences between the basic elements of (1) the classical surveying technique, and (2) the Doppler technique are contrasted. It is necessary to consider the geopotential model as part of the Doppler datum definition. Geopotential model changes create positional shifts which vary from point to point. Datum transformations on a global scale, then, are much more complicated than the recent literature indicates. Current techniques for minimizing correlated errors, principally drag, are discussed, as are immediate extensions to sub-metre precision. A major software change in the Transit orbit generation computation is planned for late 1979. A new satellite is currently in limited production. Implications for users of the system are described.
Nitrate utilization by phytoplankton in Lake Superior is impaired by low nutrient (P, Fe) availability and seasonal light limitation – a cyanobacterial bioreporter study.

We previously developed a luminescent Synechococystis sp. strain PCC 6803 cyanobacterial bioreporter that is used as a real-time whole-cell sensor to assess nitrate assimilatory capacity in freshwaters. Applying the bioreporter assay to Lake Superior, a system whose nitrate levels have increased 6-fold since 1900, we investigated factors that constrain nitrate utilization in this oligotrophic system. Clean sampling methods were used to collect water from Lake Superior during spring and summer 2004, and nitrate utilization was measured by monitoring bioreporter luminescence. Bioreporter response was monitored during experiments in which the lake water was amended with nutrients and incubated under light regimes simulating integrated spring and summer mixing depths. These studies demonstrated that nitrate utilization was enhanced at most stations following addition of phosphorus (P). Moreover, at many stations, addition of iron (Fe) enhanced the P effect. Strength-of-effect statistical analysis provided the individual contribution of P and Fe toward stimulating bioreporter response. In general, distance from shore and season were not good predictors of nitrate assimilatory capacity. Manipulation of light flux during bioreporter experiments also showed that light intensities experienced during spring mixing are likely insufficient to saturate the rate of nitrate utilization. Overall, these data suggest that P-limited algae are deficient in their ability to assimilate nitrate in Lake Superior. Furthermore, we suggest that a secondary limitation for Fe may occur that further constrains nitrate drawdown. Lastly, during spring, light fluxes are sufficiently low to prevent maximal nitrate utilization, even in the absence of nutrient limitation.
Asymptotic Analysis of the Loss Given Default in the Presence of Multivariate Regular Variation

Consider a portfolio of n obligors subject to possible default. We propose a new structural model for the loss given default, which takes into account the severity of default. Then we study the tail behavior of the loss given default under the assumption that the losses of the n obligors jointly follow a multivariate regular variation structure. This structure provides an ideal framework for modeling both heavy tails and asymptotic dependence. Multivariate models involving Archimedean copulas and mixtures are revisited. As applications, we derive asymptotic estimates for the value at risk and conditional tail expectation of the loss given default and compare them with the traditional empirical estimates.
Power controlled random access

The lack of an established infrastructure, and the vagaries of the wireless channel make the design of ad-hoc networks a challenging task. Cross-layer design for ad hoc networks has been widely advocated, because it helps overcome several suboptimalities which are introduced by designing each layer in isolation. A cross-layer design encompassing all layers of the protocol stack is hard to achieve, and hence research often looks at pairwise optimizations. One such design methodology for joint link scheduling and power control, which optimizes over the physical and MAC layer is considered here, for a cellular network scenario. By using a heuristic relaxation, the NP-hard problem of joint power control and scheduling is transformed into one of power controlled random access, which can be cast as a convex optimization problem. A physical interpretation is provided for this relaxation. An outage analysis and a Markov chain based end-to-end delay distribution analysis is presented for the proposed scheme, and the efficacy of the scheme is also studied through simulations.
PLASMA NEUTRAL 17-KETOSTEROIDS

ALTHOUGH there have been rapid advances in the determination of blood 17-hydroxycorticosteroids (1, 2,3), 21-hydroxy-20 ketosteroids (2) and 3-ketosteroids (4, 5), little is known about the concentration of 17-ketosteroids in blood. West and colleagues reported no measurable amounts of 17-ketosteroids in peripheral human blood (6). Testosterone and δ4-androstenedione have been identified in spermatic vein blood from dogs (7). Dumazert and Valensi have published values of 800 μg. to 1,200 μg. per 100 ml. for neutral 17-ketosteroids in human peripheral plasma, but found no correlation with urinary 17-ketosteroid excretion (8). This communication deals with the development of a method for the quantitative determination of 17-ketosteroids in peripheral plasma. The steroids are liberated by direct acid hydrolysis of plasma and the extracts are purified by column chromatography. A micro-modification of the Zimmermann reaction is used. Overestimation is avoided by Allen's spectrophotometric technique (9).
The MobiSoC middleware for mobile social computing: challenges, design, and early experiences

Recently, we started to experience a shift from physical communities to virtual communities, which leads to missed social opportunities in our daily routine. For instance, we are not aware of neighbors with common interests or nearby events. Mobile social computing applications (MSCAs) promise to improve social connectivity in physical communities by leveraging information about people, social relationships, and places. This paper presents MobiSoC, a middleware that enables MSCAs development and provides a common platform for capturing, managing, and sharing the social state of physical communities. Additionally, it incorporates algorithms that discover previously unknown emergent geosocial patterns to augment this state. To demonstrate Mo-biSoC's feasibility, we implemented and tested on smart phones two MSCAs for location-based mobile social matching and place-based ad hoc social collaboration.
Stability of laminar pipe flows of drag reducing polymer solutions in the presence of high‐phase‐velocity disturbances

A theoretical study of high-phase-velocity disturbances in the laminar pipe flow of drag-reducing polymer solutions is reported. These disturbances are found to be more stable in a polymer solution with a sufficiently small relaxation time than in a Newtonian fluid. The opposite effect is predicted when the relaxation time exceeds a critical value, however. These results are shown to be consistent with a hydrodynamic instability explanation of the early turbulence phenomenon.