cssi/SciSciGPT-SciSciNet huggingface dataset:
ETV1 is a lineage survival factor that cooperates with KIT in gastrointestinal stromal tumours

Gastrointestinal stromal tumour (GIST) is the most common human sarcoma and is primarily defined by activating mutations in the KIT or PDGFRA receptor tyrosine kinases. KIT is highly expressed in interstitial cells of Cajal (ICCs)-the presumed cell of origin for GIST-as well as in haematopoietic stem cells, melanocytes, mast cells and germ cells. Yet, families harbouring germline activating KIT mutations and mice with knock-in Kit mutations almost exclusively develop ICC hyperplasia and GIST, suggesting that the cellular context is important for KIT to mediate oncogenesis. Here we show that the ETS family member ETV1 is highly expressed in the subtypes of ICCs sensitive to oncogenic KIT mediated transformation, and is required for their development. In addition, ETV1 is universally highly expressed in GISTs and is required for growth of imatinib-sensitive and resistant GIST cell lines. Transcriptome profiling and global analyses of ETV1-binding sites suggest that ETV1 is a master regulator of an ICC-GIST-specific transcription network mainly through enhancer binding. The ETV1 transcriptional program is further regulated by activated KIT, which prolongs ETV1 protein stability and cooperates with ETV1 to promote tumorigenesis. We propose that GIST arises from ICCs with high levels of endogenous ETV1 expression that, when coupled with an activating KIT mutation, drives an oncogenic ETS transcriptional program. This differs from other ETS-dependent tumours such as prostate cancer, melanoma and Ewing sarcoma where genomic translocation or amplification drives aberrant ETS expression. It also represents a novel mechanism of oncogenic transcription factor activation.
Hydrodynamics of Helium II in Annular Geometry

The circulation of helium II in an arnular geometry with a hypothetical velocity field is studied. The findings suggest that for helium II in a rotating cylinder, selective choice of the cylinder's angular velocity may produce persistent circulation of helium II for long periods of time after rotation of the cylinder is stopped. (T.F.H.)
DENTAL RADIOLOGY: A PERSPECTIVE ON PRIORITIES.

Abstract Somehow dental radiologists have allowed the clear definition of basic technical objectives in dental radiology to escape any substantial attention up to this point in time. Through recent years they have also somehow allowed specific opportunities for well-supported action in the interests of their patients to escape attention. To these apparent shortcomings in the assignment of priorities for their efforts, there may well be need to add some new but related problems, stemming from certain trends currently developing within the dental profession and its specialties.
The Basics of Cheesemaking

All cheeses have a common set of principles that involve a complex web of chemical, biochemical, and microbiological changes. These changes first transform milk into fresh or unripened cheese. Although some cheeses are consumed immediately after manufacture, most are subsequently aged or ripened for weeks to years depending on the variety. During aging or ripening, a cheese's sensory characteristics undergo multifaceted and often dramatic changes. The steps performed during the earliest days of the cheesemaking process are especially critical because they establish the chemical characteristics of the cheese at the start of ripening, and these characteristics in turn affect the ripening process. For most cheeses, the key process on the first day of cheesemaking is the fermentation of lactose to lactic acid by bacteria. The rate at which lactic acid is produced profoundly affects the initial chemical characteristics of the cheese, which selectively influence the complex microbial populations that find their way from the milk and surrounding environment into the cheese. This article discusses the basics of cheesemaking by integrating the practical steps that all cheesemakers use with the scientific principles on which those practices are based. The aim is to paint a conceptual picture in which the microbiology of cheese "fits together" with the basic practices of cheesemaking and the scientific principles that underlie them.
Homoclinic orbits in a parametrized saddle-focus system

Abstract We consider a parametrized dynamical system with a saddle-focus equilibrium point and which, for one value of the parameter, has a homoclinic orbit. Conditions on the eigenvalues for the equilibrium point, together with transversality conditions, imply the existence of an infinite discrete set of parameter values for which the system has a homoclinic orbit. Such systems arise in the study of nerve axon equations where a homoclinic orbit corresponds to a finite train of nerve impulses traveling at a velocity identified by the associated parameter value.
Global obstacles to disruptive innovation in sustainable agriculture and energy

The U.S. national innovation system has a dual structure: part suited to rapid innovation, and part stubbornly resistant to change. The complex established “legacy” sectors (CELS) that resist change share common features that obstruct the market launch of innovations, beyond the “valley of death” and other obstacles that have been the traditional focus of innovation policy.
Regulation of protein synthesis in mammalian cells: V. Further studies on the effect of actinomycin D on translation control in Hela cells☆☆☆

Abstract The rate of protein synthesis in HeLa cells appears to be regulated, in part, by a factor which promotes the association of ribosomes with messenger RNA and whose production is inhibited by actinomycin. The decline in protein synthesis after the administration of actinomycin is not primarily due to a decay of available messenger RNA but, rather, is a result of a decrease in the rate of ribosomal association with message. The decay of protein synthesis in actinomycin can be varied over a wide range by altering the temperature of cell incubation. Thus the half-life of protein synthesis decay ranges from eight hours at 34 °C to two hours at 41°C. The rapid decline of protein synthesis at 41 °C is not accompanied by a corresponding decay of the messenger RNA. Polyribosomes decrease in size, but they can be restored to normal sedimentation distributions by low levels of cycloheximide, suggesting that messenger RNA remains functional. The translation rate at 41 °C is unaltered. The dose-response of protein synthesis inhibition by actinomycin was measured and a half-maximum inhibition was found to be effected by 0·1 μg of the drug/ml. Another important aspect of the regulation of translation in HeLa cells is the response of cells to depressed rates of protein synthesis. At 42 °C, protein synthesis is severely inhibited, due to a failure in the association of ribosomes with messenger RNA. Prolonged incubation at the elevated temperature results in a significant repair of the lesion. This repair is inhibited by actinomycin. The half-maximum inhibition is achieved at levels of from 0·05 to 0·1 μg of the drug/ml. The cell response to depressed rates of protein synthesis can also be demonstrated using the drug cycloheximide. Prolonged incubation in the drug results in a response which then can promote protein synthesis at 42 °C. Here again, the half-maximum inhibition of the response to cyclohemixide is achieved by 0·1 μg of actinomycin/ml. These experiments suggest, but do not prove, that the cellular response may be mediated through the synthesis of RNA that promotes the initiation of translation and does not involve the subsequent production of protein.
A passion for parasites

I knew nothing and had thought nothing about parasites until 1971. In fact, if you had asked me before then, I might have commented that parasites were rather disgusting. I had been at the Johns Hopkins School of Medicine for three years, and I was on the lookout for a new project. In 1971, I came across a paper in the Journal of Molecular Biology by Larry Simpson, a classmate of mine in graduate school. Larry's paper described a remarkable DNA structure known as kinetoplast DNA (kDNA), isolated from a parasite. kDNA, the mitochondrial genome of trypanosomatids, is a DNA network composed of several thousand interlocked DNA rings. Almost nothing was known about it. I was looking for a project on DNA replication, and I wanted it to be both challenging and important. I had no doubt that working with kDNA would be a challenge, as I would be exploring uncharted territory. I was also sure that the project would be important when I learned that parasites with kDNA threaten huge populations in underdeveloped tropical countries. Looking again at Larry's paper, I found the electron micrographs of the kDNA networks to be rather beautiful. I decided to take a chance on kDNA. Little did I know then that I would devote the next forty years of my life to studying kDNA replication.
Über den Schwefelstoffwechsel von Microsporum canis

Zusammenfassung Es wird uber die Einbeziehung in den Molekulstrukturen von Hornkeratin gebundenen Cystins sowie von freiem Cystin in den Aufbau- und Erhaltungsstoffwechsel von Microsporum canis berichtet. 1. Der zeitliche Verlauf des Wachstums und einiger typischer Stoffwechselleistungen (z. B. pH, NH3, Ausscheidung von Enzymen) mit Hornkeratin, Gelatine-Cystin oder Glutamat-Cystin als Kohlenstoff-Stickstoffquellen bestatigt und erweitert im Prinzip die Erkenntnisse uber das physiologische Verhalten der Dermatophyten beim Abbau von Proteinen oder von ihren Bausteinen. Es ist hier hervorzuheben, das freies Cystin (ca. 0,21 × 10−2 M) M. canis in der log-Phase des Wachstums vorubergehend hemmte. 2. Der Schwefelgehalt der trockenen Hornspane betrug 3,5 % (= 29,8 mg SO4— —/Kulturkolben), wovon innerhalb der Versuchsdauer ungf. 70 % durch den Pilz zu Sulfat oxidiert oder als schwefelhaltige Intermediarprodukte freigesetzt wurden. Mit Gelatine-Cystin (14,9 mg SO4— —/K) betrug der Abbau zu Sulfat ungf. 90%, mit Glutamat-Cystin (15,2 mg SO4— —/K) ungf. 70% des vorgegebenen Cystins. 3. Die Toleranz eines hohen Schwefelangebotes im Nahrsubstrat, seine Einbeziehung in den Stoffwechsel des Pilzes und besonders die Eliminierung des Schwefeluberschusses werden unter biochemischen und okologischen Aspekten zur Diskussion gestellt. Wir danken unseren techn. Assistentinnen, Frau U. Heiduk und Frau B. Dohse, fur zuverlassige Mitarbeit bei der Durchfuhrung der Versuche.
Overview of the dynamic predictive architecture for robotic assistants

A robotic assistant for extra-vehicular activity in space must deal with a complex, constantly changing environment. Classical planning architectures are ineffective for such tasks, but modern reactive systems are a plausible alternative. In addition, the robot must be capable of effective real-time response to the needs of human astronauts. Writing and debugging robot programs will not be possible under actual work conditions; astronaut-assistant dialogues must, therefore, take place in natural language. Unfortunately, the generally nonrepresentationalist nature of reactive systems make generative natural language interfaces impossible. In this paper, we present an overview of the Dynamic Predictive Memory architecture for robotic assistants. This architecture is an extension of the Direct Memory Access Parsing (DMAP) model of language understanding, in which the data structures and algorithms associated with the reactive action package (RAP) execution system are represented in the uniform memory format of the system. This allows natural language reference to take place coincident with the reactive execution of plans. The result is a reactive system which human users can interact with in natural language.© (1992) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
A plague on both your houses of worship: the meanings of epidemic disease in William Byrd II and Cotton Mather.

Treatises on epidemic disease by two North American British Colonial literary figures, William Byrd II and Cotton Mather, demonstrate similar preoccupations with epidemics’ religious meanings, despite Byrd’s Anglican and Mather’s Calvinist Congregationalist differing theological commitments. Both men situate epidemic disease in the inherent weakness of the human condition, while Byrd is more inclined toward human reason and Mather toward spiritual intervention in the selection of preventives and treatments. Mather’s role in the 1721 smallpox inoculation controversy may represent competition between Boston’s traditional ministerial intelligentsia and the emerging university-trained medical intelligentsia.
Cardiac catheterization in the patient with history of allergy to local anesthetics

Patients with a history of allergic reactions to local anesthetic drugs present a difficult problem during evaluation for cardiac catheterization procedures. In the worst cases the procedure may be deferred, or even performed without local anesthesia. In the vast majority of patients an acceptable agent for safe local anesthetic use can be found. Skin testing beginning with very dilute solutions of preservative-free local anesthetic agent may be administered easily. This report describes the practical aspects of skin testing and local anesthetic agent selection in patients with a history of allergic reaction to local anesthetic drugs.
Complications of shoulder dystocia

Complications of shoulder dystocia are divided into fetal and maternal. Fetal brachial plexus injury (BPI) is the most common fetal complication occurring in 4-40% of cases. BPI has also been reported in abdominal deliveries and in deliveries not complicated by shoulder dystocia. Fractures of the fetal humerus and clavicle occur in about 10.6% of cases of shoulder dystocia and usually heal with no sequel. Hypoxic ischemic brain injury is reported in 0.5-23% of cases of shoulder dystocia. The risk correlates with the duration of head-to-body delivery and is especially increased when the duration is >5 min. Fetal death is rare and is reported in 0.4% of cases. Maternal complications of shoulder dystocia include post-partum hemorrhage, vaginal lacerations, anal tears, and uterine rupture. The psychological stress impact of shoulder dystocia is under-recognized and deserves counseling prior to home discharge.
An investigation of microstructure evolution in cement paste through setting using ultrasonic and rheological measurements

The response of hydrating cement paste through setting are monitored using rheological measurements and ultrasonic reflection measurements. Increases in the elastic modulus and yield stress of cement paste with time are obtained from the rheological measurements. Ultrasonic measurements are performed using horizontally polarized shear waves (SH) reflected off of the hydrating cement paste. Changes in the ultrasonic signal through setting are related with changes in the porosity and stiffness of an equivalent water-filled poroelastic material, which provides identical acoustic impedance. The measured changes in the shear modulus obtained from ultrasonic measurement are shown to correlate well with increase in elastic modulus obtained from rheological measurements. The increase in the shear modulus of the porous material obtained from the ultrasonic measurements is shown to correspond well with the observed increase in the yield stress of the cement paste. By combining the information from rheological and ultrasonic measurements, it is found that even in the fluid stage there is sufficient structural integrity in the arrangement of cement grains to support low-amplitude shear stress and the evolution of a continuously connected network of cement particles within the paste is coincident with a rapid increase in the shear modulus of the porous skeleton.
Radiologic evaluation of the thymus in juvenile myasthenia gravis

Clinical records and chest radiographys of nineteen patients with juvenile myasthenia gravis treated by thymectomy were reviewed retrospectively. Correlation of radiographic findings, clinical data, and pathologic observations were sought to determine the value of radiography in the pre-operative assessment of juvenile myasthenia gravis patients. Although the vast majority of patients had normal plain films and tomographic chest radiographs the thymuses in seventeen of the nineteen patients were pathologically abnormal. The pathologic abnormalities consisted of hyperplasia and/or the presence of germinal centers within the glands. Despite these histologic abnormalities, the weights of the surgically removed thymuses were generally in the range of normal for patients of this age. None of the nineteen patients had a thymoma. In our series, there was no apparent benefit from radiographic examination of the thymus gland in consideration of thymectomy for patients with juvenile myasthenia gravis.
Plastic Manufacturing Process Selection Methodology Using Self-Organising Map (SOM)/Fuzzy Analysis

For plastic products, one of the crucial decisions made during the preliminary design stage is the selection of an appropriate manufacturing process. In many industries, the selection of the manufacturing process is primarily based on the empirical knowledge and past experience of the manufacturing personnel. This selection procedure may result in inconsistent or poor choices if the manufacturing personnel fail to map correctly the product characteristics with the manufacturing efficacy of various manufacturing processes. This paper presents an intelligent self-organising map (SOM)/fuzzy-based model to aid designers in the selection of an appropriate plastic manufacturing process. The plastic part attributes are broadly classified into three main categories: part characteristics, material type, and production requirements. A fuzzy membership function is generated for each of the attributes using the self-organising map paradigm. Fuzzy associative memories (FAMs) are used to perform reasoning on these input fuzzy sets to derive the output fuzzy sets. The output fuzzy sets are then defuzzified to determine the process compatibility scores (PCS). The working of the proposed model is demonstrated using an example case.
Estimates of net infiltration in arid basins and potential impacts on recharge and solute flux due to land use and vegetation change

Summary Human impacts on land use and vegetation in arid basins have, in some regions, altered infiltration, recharge, and groundwater chemistry. However, some modeling approaches currently used do not account for these effects. In the Trans-Pecos region of Texas the presence of modern water, increasing groundwater NO3− concentrations, and vadose zone cores flushed of naturally accumulated solutes belie the notion that basin groundwater is unaffected by overlying land use and vegetation change. Recharge to the Trans-Pecos basins is spatially and temporally variable, and due to human impacts it has likely changed since pre-western settlement time (circa 1850s). By using the INFIL 3.0.1 model, a spatially distributed model of net infiltration, the volume and spatial distribution of net infiltration was examined for two basins, Wild Horse/Michigan Flats and Lobo/Ryan Flats, with model simulations designed to examine the effects of irrigated agriculture and human impacts on vegetation. Model results indicate that recharge to the basins is not limited to mountain-front zones and discrete features (i.e., alluvial channels), rather, irrigation return flow contributes an estimated 6.3 × 107 m3 (408 mm) of net infiltration over 40 yrs and net infiltration on the basin floors could contribute between 7% and 11.5% of annual basin recharge. Model results also indicate that net infiltration may be higher under current vegetation regimes than in pre-western settlement conditions; the removal of thick dense grasslands in INFIL model simulations enhanced net infiltration by 48% or more. Results from distributed models (like INFIL) improve upon scientific understanding of the links between vegetation regime and hydrological processes; this is important for the sustainable management of arid basin aquifers in Texas and elsewhere.
Eugenics and human rights

During the Nazi era in Germany, eugenics prompted the sterilisation of several hundred thousand people then helped lead to antisemitic programmes of euthanasia and ultimately, of course, to the death camps. The association of eugenics with the Nazis is so strong that many people were surprised at the news several years ago that Sweden had sterilised around 60 000 people (mostly women) between the 1930s and 1970s. The intention was to reduce the number of children born with genetic diseases and disorders. After the turn of the century, eugenics movements—including demands for sterilisation of people considered unfit—had, in fact, blossomed in the United States, Canada, Britain, and Scandinavia, not to mention elsewhere in Europe and in parts of Latin America and Asia. Eugenics was not therefore unique to the Nazis. It could, and did, happen everywhere. #### Summary points Although eugenics programmes are usually associated with Nazi Germany, they could, and did, happen everywhere They focused on manipulating heredity or breeding to produce better people and on eliminating those considered biologically inferior In the 1920s and 1930s eugenic sterilisation laws were passed in 24 of the American states, in Canada, and in Sweden Eugenics was criticised increasingly between the wars and was attacked widely when its role in the holocaust was revealed Many people believed that individual human rights mattered far more than those sanctioned by science, law, and social needs Modern eugenics was rooted in the social darwinism of the late 19th century, with all its metaphors of fitness, competition, and rationalisations of inequality. Indeed, Francis Galton, a cousin of Charles Darwin and an accomplished scientist in his own right, coined the word eugenics Galton promoted the ideal of improving the human race by getting rid of the “undesirables” and multiplying the “desirables.” Eugenics began to flourish after the rediscovery, in 1900, …
A COMPARISON OF CORRELATION-CONSISTENT AND POPLE-TYPE BASIS SETS

Correlation-consistent basis sets are compared with Pople-type basis sets for the calculation of atomization energies using the G2(B3LYP/MP2/CC) approach. Without a higher-level correction, the smallest errors are found for the augmented- correlation-consistent polarized valence triple zeta plus tight d basis sets. However, after inclusion of a higher-level correction, the combination of the 6-311G** basis set for the high-level correlation treatment and 6-311+G(3df,2p) for the MP2 step yields the best results. At the spin-unrestricted CCSD(T) level and for the basis set considered in this work, the G2(B3LYP/MP2/CC) approach works better than the PCIX approach for the atomization energies of the 55 G2 molecules.
On the Detection of Nursing Home Use in Medicare Claims

Objective: To evaluate the sensitivity and specificity of Medicare claims data for the detection of nursing home stays. Methods: Comparison of survey-reported stays with data derived from individually-linked claims in the 1993 Cost and Use Release of the Medicare Current Beneficiary Survey. Results: Claims showed 89.7% sensitivity and 97.7% specificity for any nursing home utilization in a given year; 89.1% sensitivity and a 99.0% specificity for detecting newly-initiated nursing home stays; and when the new stay was detected, the claims could accurately date the onset of the stay within 30 days in 77.3% of the cases. (Survey-reported nursing home stays were used as the gold standard for all of these calculations.) The degree of variation in the performance of the claims as a function of demographic, clinical and utilization histories of patients is examined. Discussion: Medicare claims can be used to detect and date nursing home stays with analytically useful sensitivity and specificity. A direct validation of the claims by linkage to records of nursing home use is indicated. Application of this technique would allow further extensions in the utility of Medicare claims for gerontology, health services research and clinical epidemiology.
Perineal Approaches to the Treatment of Rectal Prolapse

Rectal prolapse is a disabling and socially isolating surgical disease that frequently strikes elderly individuals with multiple risk factors for surgical intervention. Numerous operations have been designed to correct prolapse. In choosing an approach, the surgeon must balance the medical condition of his patient against the likelihood of an effective and durable repair. Operations for rectal prolapse are divided into abdominal and perineal approaches, with the former being traditionally perceived as more morbid but more enduring, and the latter as less invasive but more prone to recurrence. These perceptions are based on observational studies and there continues to be a lack of randomized data comparing the 2 approaches in terms of morbidity, efficacy, and functional outcome. Furthermore, as new surgical tools and techniques—such as bioprosthetic materials and minimally invasive surgery—are employed, the optimal surgery for rectal prolapse remains a matter for debate.
Lysozyme in human body fluids.

Abstract The activity of lysozyme was studied in the following body fluids using the diffusion method on agarose gel: blood serum of adults and children, umbilical cord blood serum, cerebrospinal fluid, amniotic fluid, urine, saliva, gastric juice, bile, tears, mothers' milk, sperm of a healthy subject, and exudates. From the results obtained it was found that lysozyme is present in almost all body fluids, though in different amounts. In serum its activity is normally from 7 to 13 mg/l. The highest content was found in tears, about 120 times higher than in serum. A considerable amount of lysozyme was found in gastric juice, about 8 times more than in normal serum. Lysozyme activity is lowest in or absent from urine, bile and cerebrospinal fluid. In other body fluids the activity of lysozyme was found to be the same as in serum.
Analysis of acute coronary ischemia–time insensitive predictive instrument (ACI-TIPI) as a clinical prediction rule in emergency department chest pain protocol patients undergoing stress testing

Study objectives: This study is designed to determine if the Acute Coronary Ischemia–Time Insensitive Predictive Instrument (ACI-TIPI) score can identify chest pain protocol patients for whom stress testing can be avoided without increasing the number of adverse cardiac events occurring within 30 days after chest pain center evaluation. Methods: This is a prospective, observational cohort study of low- to intermediate-risk chest pain center patients for whom acute myocardial ischemia (AMI) has been excluded and provocative cardiac testing obtained. An ACI-TIPI score was assigned on arrival to the chest pain center, the results of which were blinded to the treating physician. Subsequently admitted patients underwent medical record review for death, AMI, unstable angina, cardiac interventions, and final diagnosis. All patients received a telephone call at 30 days, medical records review, and social security death index review for follow-up. Institutional review board approval was obtained with waiver of informed consent. Results: One thousand seven hundred fifty-one consecutive patients with low to intermediate risk were evaluated from June 1, 2000, through March 22, 2001, with our chest pain protocol in the chest pain center. One thousand four hundred seventy-eight patients underwent stress testing and ACI-TIPI score assignment. Of the study group, 400 patients had an ACI-TIPI score below 20; 4 of these patients were found to have an acute coronary syndrome, which leads to a miss rate of 0.01 and a negative predictive value of 0.99. In the study cohort, 265 patients had an ACI-TIPI score below 20 and were men younger than 35 and women younger than 45 years. For men younger than 35 and women younger than 45 years of age and with an ACI-TIPI score below 20, the observed cardiac event rate was zero, resulting in a negative predictive value of 100%. Conclusion: The use of the ACI-TIPI score could be applied to further risk stratify patients safely following a chest pain protocol that rules out AMI. If all male patients younger than 35 years and all female patients younger than 45 years in whom AMI was excluded and the ACI-TIPI score was less than 20 had been sent home, 217 (15%) stress tests would have been safely avoided, with no observed adverse cardiac events.
AN EXPERIMENTAL TEST OF FRAGMENTATION AND LOSS OF HABITAT WITH ORYZAEPHILUS SURINAMENSIS

This research used a model experimental system to explore the joint effects of resource fragmentation and resource deterioration on population dynamics. The system provides a rapid test of conservation theory and can aid in planning for large and expensive studies. The investigation subjected the sawtooth grain beetle, Oryzaephilus surinamensis (L.), to five experiments in which population abundance was monitored over time. Metapopulations were created by connecting adjacent vials of flour with rubber tubes. The metapopulations were arranged in rings, and food was replenished at two-week intervals. The experiments examined populations in (1) habitats becoming increasingly fragmented, (2) dynamically fragmenting structure with concurrent loss of resources over time, (3) static structure, dynamic resource loss and differing numbers of patches, (4) static structural arrangements with dynamic resource loss that mimic resource deterioration and destruction, and (5) static arrangements of connected fragments with an equal total amount of food in a few large patches or several small patches. Time series of stage-specific abundances were compared in repeated-measures ANOVA. The results show that populations respond in nonlinear ways to both the amount of food and area provided. Within a confined area, when food is plentiful, individual interaction limits population abundance. When the amount of food is reduced, population abundance becomes food dependent. Immediate increase in immature abundance was a characteristic of fragmentation while a delayed reduction of adults was characteristic of food reduction. The stage-specific interaction at intermediate food levels shows birth and death processes that control this system, and elucidates the relationship between area and food that is integral to the dynamics of patchy populations.
Patterns of muscle activation accompanying transitions in stance during rapid leg flexion

The organization of electromyographic, ground reaction force, and total body kinematic responses accompanying dynamic transitions from bipedal to unipedal stance during rapid leg flexion movements was examined in healthy human subjects. An impulse-momentum model of motion of the centre of body mass (CM) was used to predict the patterns of muscle activation among bilateral hip abductor-adductor muscles with respect to the primary task muscle. The results indicated an intralimb and interlimb coupling of hip muscle activations which preceded and accompanied the leg flexion response and were compatible with contributing to increasing and subsequently reducing momentum of the CM in the frontal plane. Overall, the findings suggested that the coordinative interaction of postural and intended movement components may be a reflection of the mechanical constraints inherent to stance alteration function.
Age-related decreases in corticotropin-releasing factor (CRF) receptors in rat brain and anterior pituitary gland.

Abstract Corticotropin-releasing factor (CRF) receptors were measured in discrete areas of brain and in anterior pituitary of 4-, 12-, 18-, and 24-month-old male Fischer rats. No significant age-related alterations in [ 125 I]ovine CRF binding were observed in the olfactory bulb, cerebral cortex, hippocampus, brainstem, and cerebellum; there was a trend for CRF binding to decrease in the striatum as a consequence of aging. Significant age-related decreases were observed in 125 I-ovine CRF binding in the anterior pituitary and hypothalamus with maximal reductions of 60 and 27%, respectively. Saturation analysis in the anterior pituitary indicated an age-related reduction in the density of CRF receptors (i.e. B max ) without an alteration in the affinity (i.e. K d ) of CRF for its binding site. Northern analysis of proopiomelanocortin (POMC) mRNA in the anterior pituitary indicated no significant differences in the levels of POMC mRNA between 4- and 24-month-old rats. These and other data suggest that the age-related decrease in anterior pituitary CRF receptors may be due to hypersecretion of hypothalamic CRF rather than a l a loss of corticotropes in the anterior pituitary.
Enabling power management for network-attached computers

Power management is an emerging area of interest for network management. This article reviews current developments and describes methods for enabling power management in network-attached computers. © 1998 John Wiley & Sons, Ltd.
Thermal diffusivity of cesium cadmium chloride

Abstract A simple method of thermal diffusivity measurement for liquids, using a periodic heat flux, is described. The thermal diffusivity of CsCdCl 3 is found to be 2.2 x 10 –3 cm 2 s –1 just above its melting point.
ON BOUNDARY CONDITIONS FOR UNBOUNDED FLOWS

SUMMARY We examine a method to impose boundary conditions on arbitrary boundaries, introduced to make domains of infinite extent finite for the purpose of numerical calculations, when a finite element discretization based on linear, bilinear or trilinear elements is used, in one, two or three dimensions, respectively. In particular, we look at the so-called ‘free’ boundary condition, which consists in retaining the boundary integrals generated by the weighted-residuals formulation along the open boundaries and adding them to the stiffness matrix. We show that this procedure is exactly equivalent to imposing on the boundary nodes a Sommerfeld radiation condition in one dimension, and a slightly modified form of the Sommerfeld boundary condition in two and three dimensions. We also show that the procedure is not applicable to the purely elliptic case. Many physical problems can be modelled mathematically by partial differential equations defined over an infinite domain. However, in order to obtain numerical approximations to their solutions, the infinite domain must be replaced by a finite domain, thereby introducing an artificial boundary over which we must impose boundary conditions.’ Determining a correct boundary condition over such artificial boundaries has been the subject of considerable work, particularly for hyperbolic equations arising from the theory of non-linear dispersive wavesz4 and the numerical solution of the Euler and Navier-Stokes equations.% For hyperbolic problems, absorbing boundary conditions can be obtained by utilizing approximate forms of the dispersion relationship. An interesting attempt has been made using finite element methods to construct absorbing ‘infinite’ element^.^ One of the most successful approaches that is applicable to hyperbolic and elliptic-parabolic problems is the use of the Sommerfeld radiation condition as introduced by Orlanski,* who evaluated the local wave speed in the vicinity of the boundary, thereby eliminating the need for advanced knowledge of the frequency of the approaching wave and making the method applicable to non-hyperbolic systems. In the finite element literature, various methods have been proposed recently to deal with different open boundary conditions;”’ however, the arguments put forth to justify the use of these boundary conditions have been rather ad hoe. In this work, we show that, for linear, bilinear and trilinear elements in one, two and three dimensions, respectively, the free boundary condition used by Papanastasiou er al., lo where the contributions of the line integrals along the open boundaries are retained in the stiffness matrix of a Galerkin finite element formulation, is equivalent to the use of a Sommerfeld-Orlanski boundary condition for convective flows and to
Bionics-Status and Plans

A brief discussion of the past and present progress in bionics is presented. Directions for future research are indicated. Emphasis is placed on some of the United States Air Force bionics programs, both present and planned. Short descriptions are given of each area of endeavor.
Ionization of liquid xenon by 241Am and 210Po alpha particles

Abstract The ionization yield of 241 Am 5.49 MeV and 210 Po 5.31 MeV alpha particles in liquid xenon has been measured as a function of electric field strength in the range 0.05 kV/cm to 20 kV/cm. Consistent results are obtained with the two sources. The maximum charge collected at 10 kV/cm is less than 10% of the total and the noise subtracted energy resolution is 2.5% FWHM at 5.49 MeV, dominated by statistical fluctuations in the number of electron—ion pairs escaping recombination. A comparison with our alpha particle data in liquid argon shows a much worse energy resolution and a different slope of the ionization curve at a given field. The different response of the two liquids is explained in terms of track ionization density and recombination dependence on track emission angle.
Simulated birdwatchers' playback affects the behavior of two tropical birds.

Although recreational birdwatchers may benefit conservation by generating interest in birds, they may also have negative effects. One such potentially negative impact is the widespread use of recorded vocalizations, or “playback,” to attract birds of interest, including range-restricted and threatened species. Although playback has been widely used to test hypotheses about the evolution of behavior, no peer-reviewed study has examined the impacts of playback in a birdwatching context on avian behavior. We studied the effects of simulated birdwatchers’ playback on the vocal behavior of Plain-tailed Wrens Thryothorus euophrys and Rufous Antpittas Grallaria rufula in Ecuador. Study species’ vocal behavior was monitored for an hour after playing either a single bout of five minutes of song or a control treatment of background noise. We also studied the effects of daily five minute playback on five groups of wrens over 20 days. In single bout experiments, antpittas made more vocalizations of all types, except for trills, after playback compared to controls. Wrens sang more duets after playback, but did not produce more contact calls. In repeated playback experiments, wren responses were strong at first, but hardly detectable by day 12. During the study, one study group built a nest, apparently unperturbed, near a playback site. The playback-induced habituation and changes in vocal behavior we observed suggest that scientists should consider birdwatching activity when selecting research sites so that results are not biased by birdwatchers’ playback. Increased vocalizations after playback could be interpreted as a negative effect of playback if birds expend energy, become stressed, or divert time from other activities. In contrast, the habituation we documented suggests that frequent, regular birdwatchers’ playback may have minor effects on wren behavior.
Bis(acetylacetonato)tricarbonyl tungsten(II): a convenient precursor to chiral bis(acac) tungsten(II) complexes.

Two equivalents of acetylacetonate (acac) have been successfully introduced into a monomeric tungsten(II) coordination sphere. With the tetracarbonyltriiodotungsten(II) anion as a precursor, the fo...
Adolescents' leisure time in the United States: partying, sports, and the American experiment.

Free time fills close to half of U.S. adolescents' waking hours, and this time has a mixed relationship to their well-being and development.
A Response: Doro Fänta: Creativity vs. Adaptation in the Ethiopian Diaspora

Invoking the common dish doro fanta ("substitute chicken stew"), served without either its traditional chicken or hard-boiled egg, as a metaphor for cultural and economic change since the Ethiopian revolution began, this short response to the volume's essays queries whether doro fanta is a metaphor for expressive invention or an adaptation of structure without substance. Following comments on a number of the essays appearing in this volume, the discussion suggests that their subject matter is more complex than the Ethiopian homeland study to which the notion of creative incorporation was originally applied. The paper ends with a brief case study of Ethiopian cooking and cuisine as aesthetic knowledge of identity and as a domain in which market forces have encouraged deviations from historical structures of taste, meaning, and processing of food. (8 February 2009)
The metabolism of very low density lipoprotein proteins. I. Preliminary in vitro and in vivo observations.

1. 1. The metabolic fate of the apoproteins of very low density lipoprotein was studied by labeling the protein moiety of very low density lipoprotein with 125I. 46–57% of the label bound to low density lipoprotein (d 1.019–1.063) apoprotein and 31–44% attached to apolipoprotein glutamic acid, apolipopotein alanine1 and apolipropotein alanine2. Following in vitro incubation of labeled very low density lipoprotein in plasma, or 10 min after intravenous injection into humans, labeled apolipoprotein glutamic acid, apolipoprotein alanine1 and apolipropotein alanine2 transferred to other lipoproteins, mainly high density lipoprotein. Low density lipoprotein apoprotein, in contrast, was confined to the very low density lipoprotein density range under these conditions. 2. 2. During the first 24 h after injection of 125I-labeled very low density lipoprotein to humans, the decay rate of low density lipoprotein apoprotein from very low density lipoprotein was faster than that of apolipoprotein glutamic acid, apolipoprotein alanine1 and apolipoprotein alanine2. During this interval, radioactivity accumalated first in a lipoprotein of intermediate density (d 1.006–1.019) and later in low density lipoprotein (d 1.019–1.063). It is suggested that apolipoprotein glutamic acid, apolipoprotein alanine1 and apolipoprotein alanine2 exchange readily between lipoproteins, but the low density lipoprotein apoprotein moiety of very low density lipoprotein moves unidirectionally from very low density lipoprotein to low density lipoprotein through a lipoprotein of intermediate density (d 1.006–1.019).
The incredible shrinking covariance estimator

Covariance estimation is a key step in many target detection algorithms. To distinguish target from background requires that the background be well-characterized. This applies to targets ranging from the precisely known chemical signatures of gaseous plumes to the wholly unspecified signals that are sought by anomaly detectors. When the background is modelled by a (global or local) Gaussian or other elliptically contoured distribution (such as Laplacian or multivariate-t), a covariance matrix must be estimated. The standard sample covariance overfits the data, and when the training sample size is small, the target detection performance suffers. Shrinkage addresses the problem of overfitting that inevitably arises when a high-dimensional model is fit from a small dataset. In place of the (overfit) sample covariance matrix, a linear combination of that covariance with a fixed matrix is employed. The fixed matrix might be the identity, the diagonal elements of the sample covariance, or some other underfit estimator. The idea is that the combination of an overfit with an underfit estimator can lead to a well-fit estimator. The coefficient that does this combining, called the shrinkage parameter, is generally estimated by some kind of cross-validation approach, but direct cross-validation can be computationally expensive. This paper extends an approach suggested by Hoffbeck and Landgrebe, and presents efficient approximations of the leave-one-out cross-validation (LOOC) estimate of the shrinkage parameter used in estimating the covariance matrix from a limited sample of data.
Development in vitro of epithelial-cell monolayers derived from fetal rat pancreas.

Purified epithelial-cell monolayers were generated in vitro from explants of fetal rat pancreas. The extent of the development of the epithelial monolayer, as determined by planimetric analysis, was enhanced by the application of two methodological procedures: (a) preincubation of fetal pancreas in situ at 27° C for 5 hr prior to dissection and explantation; and (b) incubation of the explants in medium containing a high concentration (50% to 70%) of fetal bovine serum. By utilizing such culture conditions, sheets of contiguous epithelial cells, with little or no peripheral fibroblastic contamination, were maintained for 9 days. Whereas the majority of cells within the monolayer had morphological characteristics of pancreatic ductal cells, endocrine cells were identified by the specific immunocytochemical localization of insulin and glucagon. In addition, insulin could be detected in the incubation medium throughout the course of the experiment. The simplicity of this preparation offers some advantages over other techniques including reduced chance of contamination and reduced cellular damage or death. It provides a model for future studies directed toward developing individual cell strains derived from pancreatic epithelial cells.
A microfluidic shear device that accommodates parallel high and low stress zones within the same culturing chamber

Fluid shear stress (FSS) plays a critical role in regulating endothelium function and maintaining vascular homeostasis. Current microfluidic devices for studying FSS effects on cells either separate high shear stress zone and low shear stress zone into different culturing chambers, or arranging the zones serially along the flow direction, which complicates subsequent data interpretation. In this paper, we report a diamond shaped microfluidic shear device where the high shear stress zone and the low shear stress zone are arranged in parallel within one culturing chamber. Since the zones with different shear stress magnitudes are aligned normal to the flow direction, the cells in one stress group are not substantially affected by the flow-induced cytokine/chemokine releases by cells in the other group. Cell loading experiments using human umbilical vein endothelial cells show that the device is able to reveal stress magnitude-dependent and loading duration-dependent cell responses. The co-existence of shear stress zones with varied magnitudes within the same culturing chamber not only ensures that all the cells are subject to the identical culturing conditions, but also allows the resemblance of the differential shear stress pattern in natural arterial conditions. The device is expected to provide a new solution for studying the effects of heterogeneous hemodynamic patterns in the onset and progression of various vascular diseases.
DYNAMIC MODELS ILLUSTRATING THE ENERGY BALANCE OF THE ATMOSPHERE

Abstract A generalized vorticity equation for a two-dimensional spherical earth is obtained by eliminating pressure from the equations of horizontal motion including friction. The generalized vorticity equation is satisfied by formal infinite series representing the density and wind fields. The first few terms of a particular series solution are obtained explicitly. The series appear to converge near the north pole, and determine a model of a polar air mass. Within the air mass, the coldest winds are northeasterly and the warmest are southwesterly, while the coldest air of all is at the north pole. Heating occurs in the northwesterly winds and cooling in the southeasterlies, while aside from the effect of friction the air mass as a whole is cooled. The energy balance of the air mass is investigated. It is suggested that an analogous distribution of heating and cooling may be instrumental in maintaining the general circulation of the atmosphere.