cssi/SciSciGPT-SciSciNet huggingface dataset:
Sphere Impact Induced Damage in Ceramics: III. Analysis

In parts I and II of this study, the impact surface and sub-surface damage generated in four commercially-available hot-pressed armor-grade ceramics as the result of high-velocity impact with Tungsten Carbide spheres was presented. In this paper, a preliminary mechanical analysis is presented. The ceramic response is assumed to be elastic, perfectly-plastic; hence, the dependence of compressive strength on hydrostatic pressure is largely ignored. Based upon this assumption, the impact response of the ceramic can be divided into three regimes: (I) Elastic; (II) Elastic-Plastic; and (III) Fully-Plastic. These three regimes are represented by the following ranges for the mean impact stress p m : (I)p m /Y≤1.1; (II) 1.1 ≤p m /Y≤3; and (III)p m /Y = 3, where Y is the compressive "yield" strength. The analysis considers regimes (I) and (II) only, and examines the following issues: (1) Quasi-Static Impact; (2) Critical Velocities for the Onset of Plasticity and Full-Plasticity; and (3) Impact Stress and Contact Diameter. The analysis for impact stress and contact diameter is made with respect to Silicon Carbide.
A LuxR‐type regulator from Agrobacterium tumefaciens elevates Ti plasmid copy number by activating transcription of plasmid replication genes

Summary TraR, a LuxR-type quorum-sensing transcription factor in Agrobacterium tumefaciens, activates genes required for conjugal transfer of the Ti plasmid and also enhances the copy number of a nopaline-type Ti plasmid. Here, we show that TraR increases the copy number of an octopine-type Ti plasmid up to eightfold and that TraR activates transcription of the repABC operon up to 25-fold. The ability of TraR to increase copy number was strictly dependent on several TraR-activated promoters of this operon, indicating that TraR affects copy number solely at the level of transcription. Promoter resections and mRNA transcript analysis revealed the presence of three TraR-dependent promoters. Two TraR-dependent transcription start sites are located 45.5 and 65.5 nucleotides downstream of a site called tra box II, whereas the third start site lies 42.5 nucleotides downstream of a site called tra box III. Purified TraR bound to both tra boxes with comparable affinities, causing moderate DNA bending. TraR bound and bent these two sites independently rather than synergistically. Alteration of tra box III to match the consensus sequence dramatically increased TraR-dependent expression of repABC and plasmid copy number. TraR-dependent elevation of Ti plasmid copy number caused a three- to fourfold increase in plant tumorigenesis.
An Automobile Air Conditioning Design Model

A computer program has been developed to predict the steady-state performance of vapor compression automobile air conditioners and heat pumps. The code is based on the residential heat pump model developed at the Oak Ridge National Laboratory (ORNL). Most calculations are based on fundamental physical principles, in conjunction with generalized correlations available in the research literature. Automobile air conditioning components that can be specified as input to the program include open and hermetic compressors; finned tube condensers; finned tube and plate-fin style evaporators; thermostatic expansion valves (TXV), capillary tube, and short tube expansion devices; refrigerant mass; and evaporator pressure regulator and all interconnecting tubing. Pressure drop, heat transfer rates, and latent capacity ratio for the new plate-fin evaporator submodel are shown to agree well with laboratory data. The program can be used with a variety of refrigerants, including R-134a.
Frequency and distribution of salpingitis and pelvic inflammatory disease in short-stay hospitals in the United States

Pelvic inflammatory disease is not a reportable condition in the United States. Based on data extracted from the Hospital Discharge Survey conducted by the National Center for Health Statistics, this article presents estimates of the frequency and distribution of PID in short-stay hospitals from 1970 through 1975.
Cavitating Lung Disease: A Novel Presentation of IgG4-Related Disease

Background Immunoglobulin (Ig) G4-related disease, previously referred to as IgG4-related sclerosing disease or hyper-IgG4 disease, may occur in the lung, involving alveolar parenchyma, airways, and pleura. Various pulmonary manifestations of IgG4-related disease have been reported, but to the best of our knowledge a cavitating lung disease has not been reported previously. Case report We describe a 60-year-old man who presented with hemoptysis and cavitating lung disease with clinical, laboratory, and histopathologic findings compatible with IgG4-related disease. Other potential causes of cavitation were excluded. Treatment was initiated with oral prednisone and subsequently mycophenolate mofetil was added. Follow-up 1 year later shows stable pulmonary function with complete resolution of the cavitary lesions. Conclusions We present a case of cavitating lung disease as a previously unreported manifestation of IgG4-related disease. Our patient had an excellent response to immunosuppression. An increased awareness of IgG4-related disease and its myriad of manifestations is very important for pulmonologists.
Identification and characterization of kink motifs in 1-palmitoyl-2-oleoyl- phosphatidylcholines: a molecular mechanics study

As a cis carbon-carbon double bond (delta) is introduced into the middle of an isolated all-trans hydrocarbon chain, it can be shown by molecular graphics that this delta-bond makes a bend of 130 degrees in the chain axis, thus producing a boomerang-like conformation. Such a bent structure, indeed, has been detected experimentally for oleic acid by x-ray crystallography (Abrahamson and Ryderstedt-Nahringbaur, 1962). Membrane diacyl phospholipids are largely mixed-chain lipids containing a saturated sn-1 acyl chain and an unsaturated sn-2 acyl chain. 1-Palmitoyl-2-oleoyl-phosphatidylcholine (POPC), the most abundant phospholipid in animal cell membranes, is a typical example in which the sn-2 acyl chain is the acyl chain of an oleic acid. However, this sn-2 acyl chain of POPC is unlikely to adopt a boomerang-like configuration in the gel-state lipid bilayer due to the steric hindrance imposed by neighboring chains. Instead, it has been suggested that the oleate chain in POPC is kinked in the shape of a crankshaft in the gel-state bilayer (Huang, 1977; Lagaly et al., 1977), because POPC with such a kinked sn-2 acyl chain, which is denoted here as the secondary structural element or motif, can pack efficiently against other neighboring phospholipids. In this communication, 16 different types of secondary structural elements or motifs are derived for POPC at T
Gas-focused liquid microjets from a slit

We report an experimental study on a new arrangement of flow focusing that uses a slit aperture. The slit can achieve similar flow chocking function as a classic circular aperture to established gas flow pressure drop. Fundamentally, the jetting mechanism and quantitative behavior of slit flow focusing are very similar to the classic flow focusing because of the singularity nature of the jet despite the drastically different aperture shapes. After re-scaling the jet shape, the axial coordinate with the hydraulic diameter of the slit, the experimental data follow closely with the universal jet profile derived in Ganan-Calvo, Ferrera, and Montanero [“Universal size and shape of viscous capillary jets: Application to gas-focused microjets,” J. Fluid Mech. 670, 427-438 (2011)] based on circular aperture. Practically, the slit configuration expands the possibility of manipulating the jets. The two thin plates that form the slit aperture can also be used as electrodes to apply electrohydrodynamic excitation to the jet for controlled jet breakup with narrower droplet size distribution. In addition, the modest throughput of a single flow focused jet can be increased by operating a linear array of jets focused and excited by the same slit.
Architectures for integrated service networks

In an integrated service environment where users exchange various types of aural and visual information, the networks should be user-friendly, providing tools for the management of multimedia information. The networks should efficiently satisfy the diverse performance requirements of the information being exchanged. New architectures for integrated service networks are presented which have the aim of developing document management software, allowing the manipulation of visual and voice information, and tree network architectures for reliable and efficient exchange of multimedia information.
Dynamic fiber Bragg grating strain sensor using a wavelength-locked tunable fiber ring laser

The interrogation systems based on fiber-optic sensors are very attractive for the practical applications in structural health monitoring owing to a number of advantages of optical fiber elements over their electronic counterparts. Among the fiber-optic sensors, the fiber Bragg gratings (FBGs) have their own unique features to be widely used for detection of acoustic emission. We have developed a dynamic strain sensing system by using a tunable single longitudinal mode Erbium-doped fiber ring laser to be locked to the middle-reflection wavelength of the FBG as the demodulation technique. A proportional-integral-derivative device continuously controls the laser wavelength that is kept at the FBG middle-reflection wavelength, thus stabilizing the operating point against quasi-static perturbation, while the high frequency dynamic strain shifts the FBG reflection profile. The reflected power varies in proportion to the applied strain which can be derived directly from AC photocurrent of the reflected signal. We have designed and assembled a fourchannel demodulator system for simultaneous high frequency dynamic strain sensing.
The use of a reflected code in digital control systems

The reflected (Gray) binary code has previously been used primarily in analog-to-digital conversion applications. However, the reflected binary code has, in addition, characteristics which strongly recommend it as a design factor in the synthesis of digital elements within closed-loop control systems. This paper describes several designs of typical reflected binary switching circuits. These switching circuits are, specifically, a reflected-to-conventional binary translator, reflected binary-to-analog converters, and a reflected binary contactor comparator. All of the circuit designs are logically related to the form of the reflected-to-conventional binary translator. These switching circuits can be used as digital control elements in the described original types of digital positional servomechanisms and digital accumulators.
Synthesis of the Southern FGHI Ring System of Azaspiracid‐1 and Investigation into the Controlling Elements of C28‐ and C36‐Ketalization

The azaspiracid family of natural products has stimulated significant interest in both the synthetic[1–3] and biological communities[4] due to their complex structural architecture and toxicity (Figure 1). We were initially drawn toward azaspiracid-1 (1) by the C10,C13-bis-spiroketal portion of the molecule. Our endeavors have led to a better understanding of the controlling elements behind this structural motif.[1] Herein, we detail our successful construction of the FGHI ring system present in the southern portion of azaspiracid.
IEE Computing & Control Division: Chairman's address. The human body and its transducers: a real-time real-life computing and control system

The study of how the human body functions when considered as a real-time computing and control system is of considerable interest from many points of view including those of robotics, parallel signal-processing methods and adaptive learning control systems. In particular the methods of operation of the wide range of human sensors and actuators which the body uses are of specific interest and importance in giving control engineers guidance on the development of machines which can effectively provide intelligent control of manufacturing systems, industrial processes and perhaps eventually of robotic systems in the less controlled situation in the home and leisure environments. The paper describes the basic organisation of the brain, how it can be represented as an enormously complex real-time parallel computing and control system and how its operation relates to some of the latest concepts in computing and control technology. The human senses are then considered as control system input transducers, and their engineering equivalents and their limitations are described, in particular their relevance to developments in intelligent or ‘smart’ sensors is discussed. Finally the paper describes the human output transducers as represented by the muscular system and its reflex controls.
Effect of photodynamic therapy on single cancer cells studied by integrated Raman and angular scattering microscopy

Using integrated Raman and angular scattering microscopy (IRAM), we follow the response of EMT6 cancer cells to photodynamic therapy (PDT) treatment. The study combines two non-labelling light scattering techniques to extract chemical information and organelle sizes from single cells. Each cell is measured repeatedly over several hours to follow changes in these parameters as the cell responds to the PDT treatment. An automated algorithm identifies which parameters are changing in time. Size parameters extracted from angular scattering measurements show a decrease in the size of 1-micron-diameter scatterers in treated cells. Treated cells also exhibit trends in several Raman peaks, denoting changes in chemical concentrations of proteins, nucleic acids, and lipids. Each of these parameters - acquired from both measurement modalities - can be monitored on a cell-by-cell basis. The ability to track these chemical and structural changes over time allows access to greater knowledge of biological processes.
Multimodal nonlinear microscopy at 1.5 µm

We describe multimodal nonlinear microscopy using a compact, turnkey femtosecond fiber laser at 1.5 μm. The system allows for multiplexed detection of near infrared and visible contrast agents through two-and three-photon excitation fluorescence microscopy as well as structural imaging viaauto-confocal microscopy (ACM). This platform expands the available emission spectrum for multiphoton microscopy, enables simultaneous structural and functional imaging, and offers advantages in penetration depth, contrast, and simplicity as compared to conventional MPM near 800 nm excitation.
Frequency dependence of the thermal conductivity of semiconductor alloys

The distribution of phonons that carry heat in crystals has typically been studied through measurements of the thermal conductivity $\ensuremath{\Lambda}$ as a function of temperature or sample size. We find that $\ensuremath{\Lambda}$ of semiconductor alloys also depends on the frequency of the oscillating temperature field used in the measurement and hence demonstrate a novel and experimentally convenient probe of the phonon distribution. We report the frequency dependent $\ensuremath{\Lambda}$ of ${\mathrm{In}}_{0.49}{\mathrm{Ga}}_{0.51}\mathrm{P}$, ${\mathrm{In}}_{0.53}{\mathrm{Ga}}_{0.47}\mathrm{As}$, and ${\mathrm{Si}}_{0.4}{\mathrm{Ge}}_{0.6}$ as measured by time-domain thermoreflectance over a wide range of modulation frequencies $0.1lfl10\phantom{\rule{0.3em}{0ex}}\mathrm{MHz}$ and temperatures $88lTl300\phantom{\rule{0.3em}{0ex}}\mathrm{K}$. The reduction in $\ensuremath{\Lambda}$ at high frequencies is consistent with a model calculation that assumes that phonons with mean free paths larger than the thermal penetration depth do not contribute to the thermal conductivity measured in the experiments.
DNA-polycation nanospheres as non-viral gene delivery vehicles

Abstract Nanospheres synthesized by salt-induced complex coacervation of cDNA and polycations such as gelatin and chitosan were evaluated as gene delivery vehicles. DNA-nanospheres in the size range of 200–750 nm could transfect a variety of cell lines. Although the transfection efficiency of the nanospheres was typically lower than that of lipofectamine and calcium phosphate controls in cell culture, the β-gal expression in muscle of BALB/c mice was higher and more sustained than that achieved by naked DNA and lipofectamine complexes. This gene delivery system has several attractive features: (1) ligands can be conjugated to the nanosphere for targeting or stimulating receptor-mediated endocytosis; (2) lysosomolytic agents can be incorporated to reduce degradation of the DNA in the endosomal and lysosomal compartments; (3) other bioactive agents or multiple plasmids can be co-encapsulated; (4) bioavailability of the DNA can be improved because of protection from serum nuclease degradation by the polymeric matrix; (5) the nanosphere can be lyophilized for storage without loss of bioactivity.
Electrowetting propulsion of water-floating objects

This letter describes a propulsion principle along with experimental verification of this principle by which an air-to-water interface vertically oscillated by ac electrowetting generates a quasisteady, “streaming” flow that can be utilized to propel water-floating objects. This propulsion does not require any mechanical moving parts. Using a centimeter-sized boat whose outer surfaces were covered with microfabricated electrowetting electrodes, linear, and rotational motions of the boat were achieved up to maximum speeds of 5 mm/s and 20 rpm, respectively. By combining the above two motions, the boat was successfully propelled and steered along a curvilinear pathline. A potential application of this principle is to propel and maneuver various water-floating mini/microrobots and boats used for water/air quality monitoring or surveillance/security purposes.
Debitage Stylistic Variability at Cox Ranch Pueblo

AbstractThis paper applies the method of stylistic flake analysis of to the analysis of debitage from two middens from Cox Ranch Pueblo, a late Pueblo II (ca. 1050–1130) period habitation site in west-central New Mexico. Previous research has suggested the multiethnic nature of site occupation based on the presence of two distinct methods for the manufacture of utilitarian ceramics and the site's location at the interface of two of the Southwest's traditional culture areas. This study samples debitage from two of the largest middens, each associated with a residential roomblock at the site, to determine if any of the stylistic trends found among the ceramic artifacts could be detected within the debitage from the site. Results show that there are in fact two different styles of flint knapping at the site, though both styles are present within each of the two midden assemblages. It is concluded that these two stylistic groups may relate to the two ethnic groups suggested to have co-resided at the site.
Prognostic value of contrast stress echocardiography in patients with image quality too limited for traditional noncontrast harmonic echocardiography.

Abstract Clinical data and contrast stress echocardiography (CSE) results were analyzed in 283 patients to establish the prognostic value of CSE for patients with limited echocardiogram image quality at baseline. The mean follow-up period was 736 ± 337 days. Only 7 patients (2.5%) had nondiagnostic image quality with contrast enhancement. During follow-up, 24 cardiac events (8.5%) occurred (5 cardiac-related deaths, 2 nonfatal myocardial infarction, 17 coronary revascularizations). Overall sensitivity, specificity, and positive and negative predictive values were 60.9%, 76.8%, 19.7%, and 95.5%, respectively. Kaplan-Meier event-free survival was higher for patients with a negative CSE result as compared with those with a positive CSE finding ( P
Epitope mapping of the U1 small nuclear ribonucleoprotein particle in patients with systemic lupus erythematosus and mixed connective tissue disease

Systemic lupus erythematosus (SLE) and mixed connective tissue disease (MCTD) are autoimmune illnesses characterized by the presence of high titers of autoantibodies directed against a wide range of ‘self ’ antigens. Proteins of the U1 small nuclear ribonucleoprotein particle (U1 snRNP) are among the most immunogenic molecules in patients with SLE and MCTD. The recent release of a crystallized U1 snRNP provides a unique opportunity to evaluate the effects of tertiary and quaternary structures on autoantigenicity within the U1 snRNP. In the present study, an epitope map was created using the U1 snRNP crystal structure. A total of 15 peptides were tested in a cohort of 68 patients with SLE, 29 with MCTD and 26 healthy individuals and mapped onto the U1 snRNP structure. Antigenic sites were detected in a variety of structures and appear to include RNA binding domains, but mostly exclude regions necessary for protein–protein interactions. These data suggest that while some autoantibodies may target U1 snRNP p...
Muscle sounds are emitted at the resonant frequencies of skeletal muscle

The changes in mechanical resonant frequency of whole muscles during twitch and tetanic contractions are compared to changes in frequency components of the pressure wave produced by muscles during contraction. Resonant frequencies were determined by imposing sinusoidal length changes on a muscle and observing transverse standing waves when the frequency of length change matched the muscle's resonant frequency or a harmonic of the resonant frequency. Acoustic signal instantaneous frequency spectra were calculated using time-frequency transformations including the Wigner transform and the exponential distribution. During a tetanic muscle contraction, the peak instantaneous frequency initially increased and then became constant as the force plateau was reached. The resonant frequencies determined during the force plateau and during relaxation spanned the same range as the peak instantaneous frequency of the acoustic signal. These results suggest that the acoustic signal may be useful as a noninvasive monitor of muscle resonant frequency during contraction. >
Hematopoietic Stem Cells and Aging

Hematopoiesis is a process by which a single cell--called a hematopoietic stem cell (HSC)--has the proliferative potential to give rise to all of the major lineages of blood and immune cells. Stem ...
Negative cooperativity exhibited by the lytic amino-terminal domain of human perforin: implications for perforin-mediated cell lysis

Abstract Background : Cytolytic effector cells of the immune system recognize and lyse cells that carry non-self epitopes. One mechanism of cell lysis involves release of a 67-kDa pore-forming protein, perform. The amino-terminal domain of perform (≥19 residues) can account for most of the lysis activity, by a mechanism that is similar to that of holoperforin. Detailed mechanistic studies of this domain should yield useful insight into the factors underlying perform activity in vivo . Results : The mechanism of pore formation by the 22-residue amino-terminal domain of perform was studied by kinetic and thermodynamic methods. Approximately 4 ± 1 peptide monomers form an active pore by a mechanism that displays negative cooperativity. Conclusions : A negatively-regulated aggregation mechanism is likely to be common for pore-forming peptides. The positively-charged domain B of perform (residues 7–15) may mediate cooperativity through electrostatic interactions. Such a mechanism limits the number of protein molecules that are committed to any particular channel. This data supports smaller pores as the physiologically relevant aggregate, rather than the larger ring sizesidentified by electron microscopy at higher, non-biological concentrations.
Concerning the uptake of lipid by the nucleus.

Our previous radioautographic experiments suggesting absorption of lipid by the nucleus have been followed by direct examination of liver cell nuclei isolated from the animals at various times after administration of palmitic acid-9,10-3H. Twenty four hours post administration, the radioactivity in the isolated nuclei was still present in lipid. At this and all subsequent times examined, the total radioactivity in the nuclei did not exceed 1 percent of the total present in the liver. Treatment of the nuclei with Triton X100, to remove the nuclear membranes, led to the loss of most of the radioactivity; that remaining was associated primarily with the chromatin, with very little being found in the nucleolar fraction.
Origin of Rare Gases in Natural Gases: ABSTRACT

Studies have been made by several laboratories on the isotopic and chemical abundances of He, Ne, Ar, Kr, and Xe in natural gases from both gas wells and geothermal areas. This work has shown that the rare gases consist of a mixture of two distinct components--atmospheric and radiogenic. These investigations give information on the evolution of natural gas accumulations from considering the dissolved atmospheric components and the production of He34, A40 and Xe from nuclear processes. The importance of solubility phenomena in fractionation of these elements may be approached by using a simple model. Measurements of End_Page 2076------------------------------ the radiogenic gases permit estimates of the rate of evolution of the atmosphere. End_of_Article - Last_Page 2077------------
Developing the Fearless School Counselor Ally and Advocate for LGBTQIQ Youth: Strategies for Preparation Programs

To better serve the lesbian, gay, bisexual, transgender, queer, intersex, and questioning (LGBTQIQ) youth population, counselor educators can assist school counselors-in-training in developing advocacy competencies within their training programs. A focus on advocacy competencies outlined by the American Counseling Association (ACA) and the American School Counselor Association (ASCA) standards, and infusion of techniques throughout the education process, may increase levels of comfort for neophyte school counselors-in-training when working with LGBTQIQ youth. To increase efficacy in this multicultural population, myriad environments representative of the systemic nature of the school environment and culture must be examined and explored through training processes. These authors discuss intervention strategies for counselor educators to develop future school counselor advocacy, which align with the ACA advocacy competency domain areas.
Multidimensional image and structure data representation: a generalization of the ACR-NEMA standards (Proceedings Only)

Multidimensional image data are becoming increasingly common in biomedical imaging. Three-dimensional visualization and analysis techniques based on three-dimensional image data have become an established discipline in biomedicine. Some imaging problems generate image data of even higher dimensions. It often becomes necessary to consider the higher dimensional data as a whole to adequately answer the underlying imaging questions. In spite of this established need for convenient exchange of image and image-derived information, no exchange protocols are available that adequately meet the needs of multidimensional imaging systems. This paper describes an exchange protocol that has been designed after careful consideration of the common requirements of methodologies for visualization and analysis of multidimensional data. It is based on and is a generalization of the widely accepted ACR- NEMA standards specified for two-dimensional images. It is implemented and actively being used in a data-, application-, and machine-independent software environment called 3DVIEWNIX, being developed in the authors'' department, for the visualization and analysis of multidimensional images.© (1992) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Photodynamic characterization and optimization using multifunctional nanoparticles for brain cancer treatment

Photosensitizer-conjugated polyacrylamide nanoparticles were prepared for in vivo characterization of the minimally invasive and localized treatment of photodynamic therapy (PDT) on brain tumors. By incorporating a variety of nanoparticle matrixes, choosing methylene blue as a photosensitizer, and targeting the nanoparticle by the use of F3 peptide we have made nanoparticle-based PDT improvements to current PDT efficiency. Quantitative growth patterns were determined through visual observation of the tumorigenic response to various treatments by the use of an animal cranial window model. PDT treatments with methylene blue-polyacrylamide (MB-PAA) nanoparticles produced significant adjournment of tumor growth over control groups, clearly demonstrating the advantages of nanoparticle-based PDT agents for the eradication of local tumors, leading to the potential palliation of the advancing disease.
Use of family systems in preparation for ministry

Understanding the systematic dynamics of one's family of origin is necessary in preparation for ministry and can be most powerfully effected by engaging students in one of several family therapy techniques. Moreover, a family systems orientation is useful for theological explorations regarding family and Church as family, as well as enhancing skills for ministering to the contemporary family in all its diversity.
Using interval mathematics in cost-benefit analysis of distribution automation

Abstract A method is proposed for estimating the economic value of improved distribution reliability due to automation. Since electric utilities face many uncertainties, the method utilizes interval mathematics to model uncertainty in input parameters. An interval number represents the lower and upper bounds of a parameter range. In addition, interval mathematics offers an approach to sensitivity analysis for economic decisions which does not require many simulations. An economic index for reliability is defined for use in the economic decision evaluation. An example is solved which compares automated and classical distribution system designs with different reliability levels.
Differences between hybridizable RNA during growth and differentiation of Physarum polycephalum.

Abstract The differences between hybridizable RNA during growth and during differentiation (spherulation) of the slime mold Physarum polycephalum were studied. Two modified methods were used for characterization of the classes of hybridizable RNA, according to their mobility on polyacrylamide gels. It was found that some heavier classes of RNA were depressed or quantitatively diluted during spherulation, compared with growth, whereas new classes are synthesized during the process. Most of the new classes have s -values lower than 10 S. These findings confirm the suggestions previously made that some classes of RNA are depressed during spherulation, whereas new classes are synthesized. This is consistent with the idea about the importance of transcription in differentiation.
Constrained best approximation in Hilbert space

In this paper we study the characterization of the solution to the extremal problem inf{‖x‖x ∈C ∩M}, wherex is in a Hilbert spaceH, C is a convex cone, andM is a translate of a subspace ofH determined by interpolation conditions. We introduce a simple geometric property called the “conical hull intersection property” that provides a unifying framework for most of the basic results in the subject of optimal constrained approximation. Our approach naturally lends itself to considering the data cone as opposed to the constraint cone. A nice characterization of the solution occurs, for example, if the data vector associated withM is an interior point of the data cone.
Functional distention of the kidney in perinephritic hypertension.

Abstract One kidney of dogs was wrapped in collodion-soaked bandages and the other removed. This caused malignant hypertension, and usually, fatal uremia in about seven days. The fluids draining from the incarcerated kidneys, after the artery and vein had been simultaneously clamped, were analyzed for volumes and hematocrits a few days postoperatively. The volume draining was reduced to 18 ml. per 100 Gm. of functionally distended kidney, as compared with 31 ml. per cent for normal dogs or for dogs after uninephrectomy. Both vascular blood and interstitial fluid were involved in this reduction. A reduction to 21 ml. per cent was found compatible with life. But a reduction to 16 ml. per cent was incompatible with life, for the animals soon died in fatal uremia. Severe reduction in the volume of interstitial fluid was apparently the critical change in the latter case. It is the reduction in functional distention, it is postulated, which is the stimulus to the kidney's own feed-back mechanism of renin secretion; this usually restores functional distention to normal by inflating the kidney with a higher blood pressure. But in the present experiment, this was impossible because of the straight-jacketing effect of the incarcerating collodion hull. The failure of distention then led to malignant hypertension, and finally, when hypertension was extreme, to the inflexible behavior of the kidney which is characteristic of fatal uremia. At autopsy, the animals were found to have the massive necrotizing arteriolitis characteristic of death with malignant hypertension. However, in the kidneys there was no histopathologic change. Evidently, the renal morphologic change responsible for the hypertension, and also for the uremia, was a functional change only: it could not be visualized by conventional histopathologic techniques. The theory is proposed that the critical hemodynamic defect in the kidney that leads to renal hypertension is reduction in the kidney's natural distention. This may happen in a variety of ways: by an incarcerating hull, as in the present experiment; or by partial arterial constriction, with consequent reduction in the inflating action of the blood pressure; or by the constraining effect of cicatrization and contraction in renal inflammation; or by decline in the kidney's natural elasticity with age. All lead to the same response of formation of angiotensin (and other still obscure reactions) which induces hypertension.
The use of thermal plastics for immobilization of patients during radiotherapy.

Abstract A new orthopedic casting material has been adapted to use for immobilizing patients undergoing radiation therapy. The material has proven to be less cumbersome and time-consuming than other products currently in .use. The necessary equipment and procedures required to form a immobilization cast using thermal plastic material are described.
High Jc superconducting thin films prepared by sputtering

Abstract REBaCuO (RE: Rare earth element) high Jc superconducting single crystalline films were grown on MgO (001) substrates by a magnetron sputtering. The critical current density Jc of the HoBaCuO film was 3.53 million A/cm2 at 77.3K. Even under the influence of a magnetic field of 1.0T, Jc was sustained at more than 1.5 million A/cm2 at 77/3K. X-ray, RHEED and SEM analyses showed that these films are epitaxially grown single crystals with extremely smooth surface.
Solid-phase microextraction for herbicide determination in environmental samples

Liquid-liquid extraction or solid-phase extraction followed by gas chromatography (GC) or high-performance liquid chromatography are traditional herbicide residue determination methods for environmental samples. Solid-phase microextraction (SPME) is a solventless, fast, and sensitive alternative herbicide residue extraction method that can be applied to numerous environmental matrices. The objective of this paper was to review SPME literature regarding extraction theory, extraction modes, fiber types, and method optimization in conjunction with present and future SPME applications for herbicide determination in environmental samples.
The Problem of Defining Retirement Among Minorities: The Mexican Americans

Using the 1979 Chicano Survey and four different operational definitions of retirement, we explored the effects of age, gender, health, birthplace, and lifetime work experience on the retirement of Mexican Americans. We found that correlates of retirement vary by the definition used. Frequent health limitations was associated with retirement defined by self-reported retirement or self-reported current work status, but not defined by respondents' self-described activities or receipt of retirement income. Operational definitions often used in discussions of timing and determinants of retirement, thus, poorly fit the lifetime work patterns and retirement process of Mexican Americans.
A dynamic scheduling strategy for the Chare-Kernel system

One of the challenges in programming distributed memory parallel machines is deciding how to allocate work to processors. This problem is particularly acute for computations with unpredictable dynamic behavior or irregular structure. We present a scheme for dynamic scheduling of medium-grained processes that is useful in this context. The Adaptive Contracting Within Neighborhood (ACWN), is a dynamic, distributed, self-adaptive, and scalable scheme. The basic scheme and its adaptive extensions are described, and contrasted with other schemes that have been proposed in this context. The performance of all the three schemes on an iPSC/2 hypercube is presented and analyzed. The experimental results show that ACWN algorithm achieves better performance in most cases than randomized allocation. Its agility in spreading the work helps it outperform the gradient model in performance and scalability.
Qualitative analysis of a coupled reaction-diffusion model in biology with time delays

Abstract Certain biochemical reaction can be modeled by a coupled system of time-delayed ordinary differential equations and linear parabolic partial differential equations. In a three-compartment model these equations are coupled through the boundary conditions. The aim of this paper is to give a qualitive analysis of this unusual coupled system. The analysis includes the existence and uniqueness of a global solution, explicit upper and lower bounds of the solution, and global stability of a steady-state solution. The global stability result is with respect to any nonnegative initial perturbation and is independent of the time delays in the process of reaction. Special attention is given to the Goodwin model for biochemical control of genes by a negative feedback mechanism with time delay and diffusion.
Gel isoelectric focusing of selected bovine immunoglobulins.

Abstract Commercial IgG1, IgG2, and IgM bovine immunoglobulin fractions were relatively homogeneous by acid polyacrylamide gel-electrophoresis and immunoelectrophoresis. However, isoelectric focusing in polyacrylamide gels with ampholytes covering wide and narrow pH gradients revealed heterogeneity among IgGl and IgG2 species with estimated isoelectric points in the pH ranges of 5.5 to 6.8 and 7.5 to 8.3, respectively. IgM was not resolved by gel isoelectric focusing. IgGl and IgM were tentatively identified as the major and minor immunoglobulin components, respectively, of bovine colostrum whey.
Design of a Multimicroprocessor-Based Controller Using a Structured Design Approach

As automatic industrial devices become more and more sophisticated, increasingly complicated problems are involved in their design and testing, especially in systems such as dedicated multimicroprocessor-based controllers. Failure to address the complexities of such systems before the prototype stage can result in exceedingly lengthy redesigns and frustrating, if not impossible, preproduction testing. A structured approach to both the design and testing of a complex robotic controller has been used to decompose the design/test task into manageable subtasks. Applying the approach to a legged locomotion case study has demonstrated that the structured method helps to anticipate design and testing problems by shifting effort toward the initial stages.
Pressure-volume-temperature relations in liquid and solid 3 He

Liquid and solid3He P-V-T relations were measured over 0.26–1.8 K with concentration on regions near the melting curve. The method used a cell whose volume was varied with diaphragms, the positions of which determined the volume and pressure. The molar volumes of liquidV lm and solidV sm along the melting curve were consistent with the directly measured volume change on melting ΔV m . Below 1 K,V lm , Vsm, and ΔV m were greater than previous results. Along the melting curve, the compressibility of the solid became greater than the compressibility of the liquid atT<1.2 K, the difference rising to 12% at 0.32 K. The thermal expansion of the solid became negative below 0.30–0.35 K. The melting curve minimum was measured at 28.932±0.003 atm and 0.319±0.003 K. Starting with the minimum, the melting curve was calculated to 0.02 K, where it should be useful in thermometry. A set of self-consistent data is presented.
Comparison of electron sources for high‐resolution Auger spectroscopy in an SEM

The effect of primary beam current and electron spot size on the Auger image resolution and signal‐to‐noise ratio (S/N) have been determined for field emission and thermionic emission sources. It is demonstrated that by use of a FE source and nA primary beam currents, an Auger image resolution of less than 1000 A can be obtained. The major limitation to Auger spatial resolution is attributed to backscattered electrons. A LaB6 source is clearly superior to FE sources at primary beam currents of greater than 1×10−8 A.
Absorption and luminescence of dye-coated silver and gold particles

Formulas are derived for the extinction cross section of small randomly oriented, two-layer spheroids and for the luminescence of small spheres coated with a luminescent layer. Numerical examples are presented showing the dependence of the extinction of dye-coated particles upon the particle size, the optical properties of the core (silver, gold, dielectric), the coating thickness, and the spheroid eccentricity. The interaction of metal and dye extinction bands, the splitting of these bands, and the enhancement of the extinction depend sensitively on these various parameters. The enhancement of the luminescence of dye layers coating metallic spheres is shown to be related to comparable enhancements in the extinction. The present model differs from earlier studies of surface-enhanced Raman scattering (SERS) in that the electric dipoles which simulate the dye molecules are embedded in a medium having the dielectric properties of the dye rather than dangling into the external medium. The present study utilizes air as the external medium. The enhancement effects would be much greater in water.
Magnetic Structure of Chromium Selenide

The magnetic structure of the NiAs-type compound, CrSe, has been determined by means of neutron diffraction. The indexing of superstructure lines which appear below the N\'eel point requires a unit cell three times as large as the conventional unit ($a=\sqrt{3}{a}_{\mathrm{NiAs}}$). Planes parallel to the basal plane contain three chromium atoms whose spins form an "umbrella"-like array with threefold symmetry. Individual moments alternate in sign along lines parallel to the $c$ axis. A value of 2.90 \ensuremath{\mu}b has been deduced for the component of the chromium moment perpendicular to the $c$ axis.
Thermal voltage converters for accurate voltage measurements to 30 megacycles per second

Thermal voltage converters, each consisting of a resistor in series with a thermoelement in a coaxial line, have been developed for measurements of rms voltages of 1 to 200 volts at frequencies from 3 cps (cycles per second) to 30 mc (megacycles). An accuracy of 0.1% or better may be obtained by a-c-d-c transfer techniques up to at least 10 mc and 0.2% at 30 mc.
Enantioselective synthesis of C2-symmetric diols

Catalytic reduction of diketones with erythro diphenyl oxazaborolidine yielded C2-symmetric diols in high enantiomeric excess. Enantiomeric excess increased and less meso isomer was generated when borane was employed equimolar with respect to the carbonyl groups and when stoichiometric oxazaborolidine was used.
Dynamic Biomolecule Sensing Bead Array Held by Optical Tweezers

We have developed a platform using optical tweezers to create dynamic arrays of functionalized microbeads in microfluidic channels. The array is then exposed to analyte signaling molecules and washes, and interrogated using fluorescence microscopy.
Early Nucleation of Diamond in a Combustion Flame

The early stages of a gas phase pretreatment for diamond nucleation in an oxy-acetylene flame were investigated. The pretreatment involved a low oxygen-to-acetylene ratio (Rf = 0.93) performed at 15 mm from the torch on a scratched Si substrate. The nature of the carbon species deposited was analyzed using X-ray photoelectron spectroscopy, Auger electron spectroscopy, and scanning electron microscopy. The pretreatment process produced diamond crystals after 30 seconds and a complete film in the center of the deposition area after 180 seconds. Furthermore, the pretreatment process kept the initial SiO2 layer less than the thickness generated by the control conditions, (Rf = 0.97, d = 10mm). The success of the pretreatment was attributed to changes in the flame structure and chemistry from the control conditions.
Assimilation of new information technology and organizational culture: a case study

Many organizations encounter difficulties as they adopt new information technology. This article presents a case study of a troubled information systems project based on new technology. It shows the ways in which organizational culture can work against successful new technology assimilation. The study utilizes a relatively simple organizational framework for assessing the nature of corporate culture; the framework is useful for predicting the potential for problems in new technology assimilation that have their sources in organizational culture.
Polymer degradation. II. Mechanism of thermal degradation of polyoxypropylene glycol–toluene 2,4‐diisocyanate polymer (POPG–TDI) and a block polyether glycol–TDI polymer

Thermal degradation of polyoxypropylene glycol- toluene 2, 4-diisocyanate polymer /POPG-TDI/ OCCURS by random scission of urethane linkages to regenerate hydroxyl and isocyanate
Degradation of apolipoprotein B-100 in human chylomicrons

Abstract The purpose of this study was to investigate the molecular forms of apolipoprotein B (ApoB) in human chylomicrons under well-preserved conditions. To this end, plasma and serum were collected from the same normal subjects after ingestion of a fatty meal. The samples were divided into three or four aliquots before the addition of various preservative mixtures, including antibiotics, antioxidants and proteinase inhibitors. The chylomicrons were isolated immediately, and all steps were carried out at or below 4 °C. Changes in the molecular weight of ApoB in chylomicrons were followed by a time study using 3.3% polyacrylamide gel electrophoresis containing SDS. ApoB from chylomicrons analyzed within 5 h of blood collection showed a single band with mobility identical to that of ApoB (ApoB-100) in low-density lipoproteins. When analyzed after 1–2 days, satellite bands smaller than ApoB-100 were observed, and a very faint band with Mr, 200000 appeared, which comigrated with intestinal ApoB (ApoB-48). upon storage, the molecular weight of ApoB was smaller in chylomicrons subjected to a higher number of reflotations than those in chylomicrons washed less frequently, suggesting that purified chylomicrons degrade faster. A longer storage time at 4°C (i.e., 7 or 14 days) revealed a stepwise degradation of ApoB, yielding Mr 200000 band as the prominent form. The degradation of ApoB-100 was slower when both proteinase inhibitors, leupeptin and ϵ-amino caproic acid, were employed, and the appearance of Mr 200000 band was quicker when the chylomicrons were processed at higher temperature (15–25 °C) in the absence of a proteinase inhibitor. Immunoblotting shows that the segment removed from ApoB-100 was the carboxyl-terminal portion. These results suggest the possible presence of a proteinase(s), which copurified with chylomicrons, and which converts ApoB-100 from a large to a smaller molecular form. Although the stop codon has been discovered recently in intestinal ApoB mRNA, which explains the mechanism for direct synthesis of ApoB-48, apparently ApoB-100 is also synthesized in the intestine of all eight subjects studied here, and the ApoB-100 degrades to a form which is ApoB-48-like.