cssi/SciSciGPT-SciSciNet huggingface dataset:
Analysis of the critical Weber number at the onset of liquid entrainment in capillary-driven heat pipes

Abstract Entrainment phenomena in capillary-driven heat pipes were studied and both analytical and experimental approaches were utilized to identify and better understand the parameters that govern the entrainment of liquid in operating heat pipes. A heat pipe experiment was conducted using a high power heat pipe, designed to verify the existence of the various modes of entrainment and measure the corresponding entrainment limits. In addition, entrainment limit data were theoretically verified using a computer model designed to predict the maximum performance for the given operating conditions. Entrainment was detected by various methods and classified into representative types according to the relative position of the liquid interface to the wick structure and the operating conditions. Results of the experiment were compared with those obtained from previous investigations presented by Cotter, Tien and Chung and Prenger and Kemme. From the comparison of the critical Weber number or vapor velocity, the effectiveness of previous aerodynamic simulations was also examined.
A simple and effective ‘first’ optical image processing experiment

Optical image processing experiments can contribute to an understanding of optical diffraction and lens image formation. We are trying to discover a highly effective way of introducing lens imaging and related topics, light scattering, point sources, spatially coherent light, and image processing, in a laboratory-based holography-centered introductory optics course serving a mixture of physics, chemistry, and science education sophomores and juniors. As an early experiment in this course, a microscope slide bearing opaque stick-on letters forming a word such as PAL is back-lighted by a point source of laser light. The surround for the letter A is transparent, while the surround for the letters P and L is made translucent with Scotch MAGIC™ tape. A 20-cm focal length converging lens forms a bright image of PAL on a screen, and also an image of the laser point source in a (transform) plane between the lens and the screen. Students are startled when they see that they can choose to pass only the image of the letter “A” or only the images of “P” and “L,” by very simple manipulations in the transform plane. The interpretation of these experiments is challenging for some students, and the experiments can lead to a significant amount of discussion. Useful explanatory ray diagrams will be presented. Many demonstrations of optical image processing require long focal length lenses and precise manipulation of somewhat complex passing/blocking filters. In contrast these experiments are easy to set up and easy to perform. Students can fabricate the required objects in a matter of minutes. The use of zero-order laser light helps students discover the essential simplicity of the ideas underlying image processing. The simultaneous presence of both scattered (spatially incoherent) and not scattered (spatially coherent) laser light is thought provoking. Current explorations to further develop these and other closely-related experiments will also be described.
The distribution of Lyapunov exponents: exact results for random matrices

Simple exact expressions are derived for all the Lyapunov exponents of certainN-dimensional stochastic linear dynamical systems. In the case of the product of independent random matrices, each of which has independent Gaussian entries with mean zero and variance 1/N, the exponents have an exponential distribution asN→∞. In the case of the time-ordered product integral of exp[N−1/2dW], where the entries of theN×N matrixW(t) are independent standard Wiener processes, the exponents are equally spaced for fixedN and thus have a uniform distribution as N→∞.
A brief synopsis of the role of human papillomaviruses in cervical carcinogenesis

The expansion of our knowledge in the realms of pathology, epidemiology, and molecular biology of human papillomaviruses (HPV) has defined them as the major and best understood class of true human tumor viruses. The interaction of the papillomavirus genome with its host cell produces the majority of cytologic abnormalities at which cervical cancer screening is directed. The epidemiologic pattern of HPV infection accounts for the established association of cervical neoplasia with sexual activity. The molecular interactions of the HPV genome with its host cell suggest a plausible mechanism for its carcinogenic action. This presentation will succinctly review current knowledge of HPV biology to facilitate an understanding of the clinical significance of this virus.
Biosynthesis and metabolism of prostaglandins in chick epiphyseal cartilage

Abstract Microsomal fractions of cells isolated from chick epiphyseal cartilage catalyzed the synthesis of prostaglandins from radiolabeled Δ 8,11,14 -eicosatrienoic and from archidonic acids. In addition, the microsomal supernatants contained both 15-hydroxyprostaglandin dehydrogenase and prostaglandin 15-keto Δ 13,14 -reductase activities. Two major classes of prostaglandins (E and F) were synthesized; however, a major product which chromatographically behaves as PGA was also isolated. Synthetase activities were analyzed for pH optima and response to known stimulators and inhibitors of prostaglandin synthesis. The different activators had varying stimulatory effects on prostaglandin synthesis; the anti-inflammatory drugs were all strongl inhibitory. Synthetase activity in the growth plate was highest in the zone of hypertrophy, declining substantially in the more heavily calcified regions. Degradative enzyme activities were highest in the zone of maturation and significantly lower in the adjacent hypertrophic zone. The net effect of these opposing activities would be to elevate prostaglandin levels at the zone of hypertrophy, a finding which suggests that prostaglandins may play a role in the modulation of epiphyseal cartillage metabolism.
The Malone Antegrade Continence Enema for Neurogenic and Structural Fecal Incontinence and Constipation

Problems of fecal elimination are commonly encountered by the pediatric urologist and surgeon. The Malone antegrade continence enema has been described as a means to administer a large volume enema via a continent catheterizable appendicocecostomy, resulting in reliable fecal elimination. Of 22 patients undergoing this procedure 16 reported total continence 4 months or longer after surgery. Complications are relatively minor and tap water appears to be a safe solution for the antegrade continence enema. A nonrefluxing, imbricated appendicocecostomy is preferable to prevent cutaneous fecal or gas leaks.
X-ray production range in solids by 2-15 keV electrons

A modified equation is proposed for the X-ray production range of 2-15 keV electrons in solids. The modification is obtained by an experimental procedure which compares the difference in X-ray intensities between pure element thin films and 'bulk' standards. The elements evaluated were Al, Ti, Ni, Zr, Nb, Mo, Pd, Ta and Pt. Monte Carlo simulations were made for several of the elements and agree with experimental results to within 5%. There was one exception, in the case of a high-atomic-number film (Pt on Si) at low keVs. Here the deviation increases to 10-20%. The modified equation is also compared to other range equations in the literature.
Stable Docking of Neutralizing Human Immunodeficiency Virus Type 1 gp41 Membrane-Proximal External Region Monoclonal Antibodies 2F5 and 4E10 Is Dependent on the Membrane Immersion Depth of Their Epitope Regions

The binding of neutralizing antibodies 2F5 and 4E10 to human immunodeficiency virus type 1 (HIV-1) gp41 involves both the viral membrane and gp41 membrane proximal external region (MPER) epitopes. In this study, we have used several biophysical tools to examine the secondary structure, orientation, and depth of immersion of gp41 MPER peptides in liposomes and to determine how the orientation of the MPER with lipids affects the binding kinetics of monoclonal antibodies (MAbs) 2F5 and 4E10. The binding of 2F5 and 4E10 both to their respective nominal epitopes and to a biepitope (includes 2F5 and 4E10 epitopes) MPER peptide-liposome conjugate was best described by a two-step encounter-docking model. Analysis of the binding kinetics and the effect of temperature on the binding stability of 2F5 and 4E10 to MPER peptide-liposome conjugates revealed that the docking of 4E10 was relatively slower and thermodynamically less favorable. The results of fluorescence-quenching and fluorescence resonance energy transfer experiments showed that the 2F5 epitope was more solvent exposed, whereas the 4E10 epitope was immersed in the polar-apolar interfacial region of the lipid bilayer. A circular dichroism spectroscopic study demonstrated that the nominal epitope and biepitope MPER peptides adopted ordered structures with differing helical contents when anchored to liposomes. Furthermore, anchoring of MPER peptides to the membrane via a hydrophobic anchor sequence was required for efficient MAb docking. These results support the model that the ability of 2F5 and 4E10 to bind to membrane lipid is required for stable docking to membrane-embedded MPER residues. These data have important implications for the design and use of peptide-liposome conjugates as immunogens for the induction of MPER-neutralizing antibodies.
Medication Adherence and Treatment Patterns for Hypogonadal Patients Treated with Topical Testosterone Therapy: A Retrospective Medical Claims Analysis

Abstract Introduction There is limited information on adherence to topical testosterone replacement therapy (TRT) among hypogonadal men. Aim To determine adherence rates among men treated with topical testosterone gels and to examine factors that may influence adherence, including age, presence of a specific diagnosis, and index dose. Methods Included were 15,435 hypogonadal men, from the Thomson Reuters MarketScan® Database, who had an initial topical testosterone prescription in 2009 and who were followed for 12 months. Main Outcome Measures Adherence to testosterone was measured by medication possession ratio (MPR), with high adherence defined as ≥0.8. Persistence was defined as the duration of therapy from the index date to the earliest of the following events: end date of the last prescription, date of the first gap of >30 days between prescriptions, or end of the study period (12 months). Results Adherence to topical TRT was low. By 6 months, only 34.7% of patients had continued on medication; at 12 months, only 15.4%. Adherence rates were numerically similar among men who received AndroGel® or Testim® topical gels and did not differ among men of different age groups. Approximately 80% of patients initiated at the recommended dose of 50 mg/day. Over time, an increased proportion of men used a higher dose. This change was the result of dose escalation, rather than of greater adherence among men initiating therapy at a high dose. Dose escalation was seen as early as 1 month into therapy. Approximately 50% of men who discontinued treatment resumed therapy; most men used the same medication and dose. Conclusions Discontinuation rates are high among hypogonadal men treated with testosterone gels, irrespective of their age, diagnosis, and index dose. Further study, evaluating other measurable factors associated with low adherence among patients receiving topical TRT, may lead to interventions designed to improve adherence with therapy.
Effects of hydraulic jump location on air entrainment in closed conduits

In vented closed conduit conveyance systems, air entrained through hydraulic jumps can be problematic for system operation. While various factors influencing air entrainment have been reported in the literature, no specific attention has been paid to the hydraulic jump location relative to the point of downstream air release. To better understand the effects of jump location on air entrainment, in this study, experiments were conducted in a vented, circular conduit with variable hydraulic jump locations relative to the pipe outlet. When the hydraulic jump was fully contained within the pipe, the air entrainment rate was dependent on the Froude number immediately upstream of the jump but was independent of the jump location within the pipe. The rate of air entrainment significantly increased, however, when the hydraulic jump was not fully contained within the pipe. For this condition, the distance from the toe of the jump to the pipe outlet significantly influences the air entrainment rate.
Biochemical "Defect" in the Hypertrophied and Failing Heart Deleterious or Compensatory?

"It is generally established that the normal heart may become incapable of maintaining an adequate cardiac output or preventing venous engorgement whenever it is presented acutely with an overwhelming load beyond its pumping capacity. This state is not failure of a diseased heart, but it has been designated `failure' by many. It is more difficult to define the situation where such an overload sets up a vicious cycle which progressively potentiates the load upon the heart for hours or days. After a lapse of time, this load strains the mechanisms available for compensation to the point where venous congestion or reduced cardiac output becomes evident. Does this turning point mean that the heart has become abnormal, in a functional sense, and, therefore, is it now to be a case of heart failure in the accepted sense? . . . How much of the circulatory change is due to the load and how much to mechanisms called upon to meet the load? When does myocardial deterioration begin, and when does myocardial failure sta...
ELECTRON MICROSCOPY OF BASOPHILIC STRUCTURES OF SOME INVERTEBRATE OOCYTES I. PERIODIC LAMELLAE AND THE NUCLEAR ENVELOPE

Highly basophilic plate-shaped regions from oocytes of the surf clam have been examined with the electron microscope. The regions are composed of flat, hollow vesicles perforated by pores arranged, in surface view, in a hexagonal pattern. Cross-sections of this structure show a periodicity consisting of loops (cross-sections of the continuous space within the vesicle) alternating with spaces partly filled with dense material (pores). These structures are shown to resemble closely, the nuclear envelope. Similarities to and differences from basophilic regions of other cells are discussed and it is suggested that the small granules of Palade (38) are represented by granules composing the walls of the annuli of the nuclear envelope and assumed to be present in the annuli of the vesicles. Because of differences in the structure of these regions from basophilic regions of other cells, the name periodic lamellae is suggested since the structures show periodically repeating substructures (annuli) in both cross-sections and surface views.
Vaporization behavior of lithium oxide: Effect of water vapor in helium carrier gas

Abstract The effect of water vapor in a helium carrier gas on the vaporization behavior of lithium oxide has been investigated in the temperature range 1023 to 1273 K. Based on the reaction Li2O(s)+H2O(g) → 2LiOH(g), the results of this study yield second and third law heats of reaction of 79.0 ± 3 and 82.1 ± 1 kcal/mol. Moisture significantly enhances the volatility of lithium oxide. The pronounced effect of water vapor on the volatilization of Li2O (as LiOH) is important in understanding the behavior of a Li2O solid breeding blanket in anticipated fusion reactor environments.
Behavioral plasticity in crustacea: why not more?

Abstract The extent of plasticity in the behavior of hermit crabs is reviewed. Data are presented demonstrating that in the hermit crab Calcinus tibicen, the diversity of experience with shell types affects the ease with which crabs enter novel shells. Hermit crabs that had more diverse experience with shell types made fewer mistakes and entered novel shells more quickly than individuals with less diverse experience. Examples of the limitations on the extent of plasticity are reviewed and some of the mechanisms which could lead to limitations are discussed. These mechanisms include (a) sensory capabilities, (b) morphological constraints, (c) limits on learning abilities, and (d) constraints by cognitive structure, i.e. the nature of the connections between categories of behavior. As an example of the latter, data are presented for the hermit crab Clibanarius vittatus showing that crabs that regularly detected blood of conspecifics (a presumed indicator of a high predation level) did not select different shells than controls not exposed to such input.
Investigating patterns of service use by families providing care for dependent elders.

The behavioral model developed by Andersen in 1968 was used to investigate patterns of support service use by families caring for dependent elders. It was hypothesized that differences in background or predisposing factors that serve to define caregivers (e.g., spouse vs. adult-child) would interact with need factors to influence the use of "discretionary" support services (e.g., adult day care), but not influence the use of "nondiscretionary" services (e.g., hospitalization). Information was obtained on the use of eight different support services from a sample of 503 caregiving dyads. Caregivers were either spouses or adult children of the dependent elder. The results supported the hypotheses derived from the behavioral model and indicate that, among caregiving families, it is important to consider not only the type of service, but who is assessing the need for that service.
VOCATIONAL INTERESTS, PERSONALITY AND EFFECTIVE POLICE PERFORMANCE

Scores on vocational interest inventories are commonly thought to be unrelated to job performance. A close examination of the literature suggests, however, that vocational scales other than those describing the occupational group in question may often predict job performance. A case in point is reported here, using Holland's Self Directed Search and two groups of policemen. Scores on the Artistic and Conventional scales consistently predict effective performance as a patrolman in this Realistic and Social occupation. CONVENTIONAL wisdom in the field of vocational psychology tells us that vocational interest inventories rarely predict work performance (cf. Strong, 1943, pp. 13-16). In fact, conspicuous warnings to that effect often accompany instructions for interpreting a client's test results. Given that vocational interests are linked to personality variables such as temperament and interpersonal style (Costa, Fozard, and McCrae, 1977), and personality is related to vocational success (e.g., Harrell, 1972), it is somewhat surprising to find that interest inventories do not predict work performance. Muchinsky and Hoyt (1974) attribute this apparent paradox to the methodology of previous research. In Muchinsky and Hoyt's own study, engineers were scored on the Group I1 (science and engineering) and Group V (social service) scales of the Strong Vocational Interest Blank when they were still in school. Correlations several years later between these scales and criteria of work performance were small ,(.20 to .30) and nonsignificant except those between Group V scores and self- and peer-ratings. Muchinsky and Hoyt stress that very
Simulations of the TJNAF FEL with tapered and inversely tapered undulators

Experiments using the TJNAF FEL have explored the operation with both tapered and inversely tapered undulators. We present here numerical simulations using the TJNAF experimental parameters, including the effects of taper. Single-mode simulations show the effect of taper on gain. Multimode simulations describe the evolution of short optical pulses in the far infrared, and show how taper affects single-pass gain and steady-state power as a function of desynchronism. A short optical pulse presents an ever-changing field strength to each section of the electron pulse so that idealized operation is not possible. Yet, advantages for the recirculation of the electron beam can be explored.
Randomized clinical trial of two anesthetic techniques for intravitreal injections: 4% liquid lidocaine on cotton swabs versus 3.5% lidocaine gel

Objective: To compare same-day and next-day pain control and safety of two anesthetic techniques utilizing 4% liquid lidocaine applied with sterile cotton swabs versus 3.5% lidocaine gel for intravitreal injections. Main outcome measures were: discomfort during anesthetic preparation and needle penetration, 1 and 24 h after injection. Methods: Patients were randomized to alternate anesthetic method at two consecutive injections in one eye or in different eyes on the same day if requiring bilateral injections. Overall satisfaction, corneal staining, and subconjunctival hemorrhage (SCH) were compared. Results: Fifty patients were enrolled. Both methods resulted in similar mild discomfort during anesthetic preparation, 1 and 24 h later. The gel resulted in slightly higher discomfort during needle penetration (p = 0.026). Patients were satisfied with both techniques (p = 0.91), however, 52% patients preferred gel, 33% were indifferent, and 15% preferred cotton swabs (p = 0.002). There were significantly less ...
The constant volume hypothesis for the inelastic deformation of metals in the small strain range

Abstract : In plasticity and creep theory it is generally assumed that inelastic deformations are volume preserving. Available tensile and creep tests were evaluated to see whether the experiments confirm the constant volume assumption. None of the experiments which were done on a variety of structural metals confirmed the constant volume hypothesis. (Author)
Type of alcoholic beverage and risk of myocardial infarction

We examined the relation of alcoholic beverage type and risk of myocardial infarction (MI) in a case-control study among 340 cases of MI and an equal number of age-, sex-, and community-matched controls. Alcohol consumption was estimated using a food frequency questionnaire, with alcohol drinkers defined as those consuming > or = 1/2 drink/day on average of any alcoholic beverage. Beer, wine, and liquor drinkers had at least half of their consumption from 1 beverage type. Fasting venous blood samples were obtained and analyzed for lipid profiles. Compared with nondrinkers, after adjustment for age and sex, reductions in risk of MI were similar for regular drinkers of any type of alcoholic beverage (relative risk [RR] 0.54; 95% confidence interval [CI] 0.37 to 0.79; p = 0.001), beer (RR 0.55; 95% CI 0.31 to 0.97; p <0.05), wine (RR 0.48; 95% CI 0.27 to 0.87; p <0.05), and liquor (RR 0.59; 95% CI 0.38 to 0.91; p <0.05) drinkers. Comparable benefits remained apparent even after multivariate adjustment for a wide range of nonlipid coronary risk factors. High-density lipoprotein (HDL) levels were significantly higher in all 4 beverage categories when compared with levels in nondrinkers, and as expected, adjustment for total HDL, a major direct effect of alcohol, substantially attenuated the protective effect in all 4 beverage categories. Relative risks were 0.94 for any beverage, 1.09 for beer, 0.97 for wine, and 0.83 for liquor after further adjustment. This strongly suggests that the protective effect of each beverage type is, in large part, mediated by increased HDL. These data indicate that regular consumption of small to moderate amounts of alcoholic beverages, regardless of the type, reduces the risk of MI, and further suggest that there is benefit, in large part, from increases in HDL levels.
Chua's oscillator: A compendium of chaotic phenomena

Abstract Chua's oscillator is the only real physical object known to date in which chaotic behavior has been observed experimentally and numerically, and proved rigorously. In summarizing the chaotic phenomena observed so far from the oscillator we emphasize its universality by showing how the dynamical phenomena from other 3D oscillators can be reproduced by using Chua's oscillator. The possibility of its use as an elementary cell in cellular neural networks is briefly discussed.
Ecosystem service value and agricultural conversion in the Amazon: implications for policy intervention.

We explore the welfare implications of agricultural expansion in the Brazilian Amazon by comparing spatially explicit estimates of soybean rents and the value of ecosystem services. Although these estimates are generated from different datasets, models, and estimation techniques, the values are comparable, such that the value of ecosystem services is greater than soybean rents for about 61% of the total area and 24% of the area where soybean rents are positive if protected areas are well enforced. Based on the balance between the benefits and costs of conversion, failure to value ecosystem services reduces total social welfare by 7.13 billion dollars annually relative to an optimum. Policy instruments that internalize the value of ecosystem services via protected lands, land conversion taxes, conservation subsidies, or excise taxes can avoid much of this loss. Regardless of intervention regime, policy makers should be cognizant of the diminishing net benefits of converting natural ecosystems to agriculture. Realizing the final 3.8% requires the conversion of an additional 15% natural ecosystems to soybean production.
Two-player repeated games with nonobservable actions and observable payoffs

This paper studies two-person repeated games in which after each stage a player is informed about the payoff he received at the previous stage. The information can, in some cases, include more than that. Four kinds of Nash-equilibrium concepts are defined by the limit of the means. A characterization of the equilibrium-payoffs sets and several properties of these sets are given. As a specific example, the standard information case, that of the folk theorem, is provided.
Granulomatous Adenohypophysitis after Interferon and Ribavirin Therapy

Objective: To describe a case of granulomatous hypophysitis occurring after treatment with interferon alfa-2b and ribavirin for hepatitis C. Methods: Clinical, radiologic, laboratory, and pathologic assessments of a woman with granulomatous hypophysitis and interferon-induced thyroiditis are presented. Results: A 42-year-old woman with hepatitis C was treated with interferon alfa-2b and ribavirin for 5 months. She was referred after symptoms of thyrotoxicosis developed, in conjunction with laboratory and radiographic evidence of thyroiditis. During the initial evaluation, she was weak and hypotensive; biochemical evaluation showed undetectable plasma cortisol and corticotropin concentrations. Magnetic resonance imaging revealed diffuse enlargement of the pituitary gland, which encroached on but did not compress the optic chiasm. Treatment with supraphysiologic doses of prednisone resulted in clinical and radiographic improvement. Once physiologic doses of glucocorticoids were instituted, however, follow-up magnetic resonance imaging showed substantial progression of the diffuse pituitary enlargement and mild compression of the optic chiasm. Surgical debulking of the mass and histologic evaluation showed chronic, noncaseating granulomatous hypophysitis. An extensive evaluation for secondary causes of granulomatous inflammation of the pituitary revealed only an elevated angiotensin-converting enzyme level; no organisms were identified. After 2 courses of high-dose glucocorticoids, she had radiographic evidence of decreased size of the pituitary lesion but continued to have multiple anterior pituitary hormone deficiencies. Conclusion: Granulomatous hypophysitis and sarcoidosis of the pituitary are rare disorders. Hypophysitis should be considered in patients receiving interferon and ribavirin therapy who have symptoms consistent with pituitary dysfunction. (Endocr Pract. 2007;13:169-175)
A scalable algorithm for maintaining perpetual system connectivity in dynamic distributed systems

We investigate the problem of maintaining a topology with small degree as well as small diameter in a dynamic distributed system such that the system always stays connected and processes that wish to leave the system can do so quickly. Perpetual system connectivity is necessary to solve many important problems in dynamic distributed systems, including atomic broadcast and stable property detection, that need strict (deterministic) guarantees about system connectivity to be solvable. To our knowledge, in all existing topology maintenance algorithms for asynchronous distributed systems that provide perpetual system connectivity, either: (i) the topology has large worst-case degree and/or diameter (ii) a process may experience high worst-case delay when leaving the system, or (iii) processes cannot join and/or leave concurrently. In this paper, we present a spanning tree maintenance algorithm that satisfies the following desirable properties. First, the spanning tree has small maximum degree of O(1) and small maximum diameter of O(log N), where N denotes the maximum size of the system. Second, any process can leave the system within O(log N) time even in the presence of concurrent arrivals and departures. Third, the system always stays connected. We show using a simple knowledge-based argument that, in any algorithm that maintains perpetual connectivity such that the topology has either worst-case diameter of Ω(log N) or worst-case degree of O(1), the departure of a process may be delayed by Ω(log log N) time in the worst-case.
Random-sequence stimulation of the G1 hair afferent unit.

Impulse trains were recorded from the parent axon of the cat G1 hair afferent unit. Separate random (Poisson-like) trains of mechanical stimuli were applied to two coinnervated receptive field hairs individually or concurrently. The objective was to determine whether the parent axonal impulse train elicited by dual-hair stimulation was due to a temporal combining (“mixing”; Fukami, 1980) of the impulse trains elicited in the parent axon by the same stimulation to each hair alone. Both impulse rates and patterns were assessed. During single-hair random stimulation, impulse trains differed from stimulus trains, having lower mean rates and short-interval doublets. During dual-hair random stimulation, mean impulse frequencies were on average 36% less than those predicted for mixing. There were no correlations between stimulus amplitude and departures from mixing. As a further test of the mixing hypothesis, the two single-hair-elicited impulse trains were temporally merged (i.e., superimposed to form one impul...
Velocity sensitivity of slice-selective excitation.

The purpose of this study was to investigate how flow affects slice-selective excitation, particularly for radiofrequency (rf) pulses optimized for slice-selective excitation of stationary material. Simulation methods were used to calculate the slice profiles for material flowing at different velocities, using optimal flow compensation when appropriate. Four rf pulses of very different shapes were used in the simulation study: a 90° linear-phase Shinnar-LeRoux pulse; a 90° self-refocusing pulse; a minimum-phase Shinnar-LeRoux inversion pulse; and a SPINCALC inversion pulse. Slice profiles from simulations with a laminar flow model were compared with experimental studies for two different rf pulses using a clinical magnetic resonance imaging (MRI) system. We found that, for a given rf pulse, the effect of flow on slice-selective excitation depends on the product of the selection gradient amplitude, the component of velocity in the slice selection direction, and the square of the rf pulse duration. The shapes of the slice profiles from the Shinnar-LeRoux pulses were relatively insensitive to velocity. However, the slice profiles from the self-refocusing pulse and the SPINCALC pulse were significantly degraded by velocity. Experimental slice profiles showed excellent agreement with simulation. In conclusion, our study demonstrates that slice-selective excitation can be significantly degraded by flow depending on the velocity, the gradient amplitude, and characteristics of the rf excitation pulse used. The results can aid in the design of rf pulses for slice-selective excitation of flowing material.
The Seismic Noise Environment of Antarctica

Online Material: Table of station parameters; figures of mean acceleration power differences, interpolated noise maps. Seismographic coverage of Antarctica prior to 2007 consisted overwhelmingly of a handful of long running and sporadically deployed transient stations, many of which were principally collocated with scientific research stations. Despite very cold temperatures, sunless winters, challenging logistics, and extreme storms, recent developments in polar instrumentation driven by new scientific objectives have opened up the entirety of Antarctica to year‐round and continuous seismological observation (e.g., Nyblade et al. , 2012). Motivations for these recent studies include improved understanding of seismogenic, volcanic, tectonic and glaciological processes, heat flow, dynamic glaciological/ocean interactions, and mantle viscosity. Such studies contribute generally to improvements in understanding the geophysical, geological, and glaciological history of the continent and how these processes interact with the past and present state of the glaciological and climate system (e.g., Winberry et al. , 2009; Hansen et al. , 2010; West et al. , 2010; Winberry et al. , 2011; Heeszel et al. , 2013; Lough et al. , 2013; Chaput et al. , 2014; Accardo et al. , 2014), including processes relevant to glacial isostatic adjustment and sea level rise (Intergovernmental Panel on Climate Change [IPCC] Report, 2007). In addition, microseisms arising from ocean wave activity contain useful climate proxy information on the state and variability of the relatively poorly sensed southern oceans (Aster et al. , 2008; Stutzmann et al. , 2009; Aster et al. , 2010), and such observations are sensitive to sea ice concentration and areal coverage in the polar regions (Grob et al. , 2011; Tsai and McNamara, 2011; Koch et al. , 2013). This characterization of the seismic noise environment of Antarctica, documentation of instrument performance, and comparisons of installation conditions (e.g., ice vaults vs. rock sites) is intended to facilitate optimization …
ACTIVE IMMUNITY TO POLIOMYELITIS IN CHIMPANZEES FOLLOWING SUBCLINICAL INFECTION

This report is concerned with the production of subclinical poliomyelitis in the chimpanzee, and immunity to such infection. Subclinical infection was produced in eight chimpanzees by the administration of virus orally or intracutaneously, and was measured by the production of a virus carrier state and the development of neutralizing antibodies. Immunity was tested by attempting to induce the carrier state again by a challenge dose of virus by the same routes. With an homologous strain as the challenge virus, immunity as defined here was produced in each of four chimpanzees tested. Neutralizing antibodies to the homologous strain were present about 1 month following the first exposure to virus by either the oral or cutaneous route. In another group of two chimpanzees, one developed neutralizing antibodies and immunity to heterologous strains, and one did not.
Spelunking in the data mine: on data mining as an analysis tool for the optimization of microprocessor speed

The quest for increased microprocessor speeds is inexorable... as microprocessor speeds pass two gigahertz, semiconductor manufacturers must wring all the available microprocessor speed from existing processes by any means possible. These means include designed experimentation and analysis of tightly controlled processes, many of which are approaching physical limits. Some questions an engineer must face when confronted with optimizing a 400-operation process is: At which operation to begin, and what factors in that operation influence what responses in the process? Then, after defined optimization projects have been completed: Have all the available opportunities for optimization been exhausted? One of the major products of microelectronics manufacturing is data: huge quantities of data are generated on every production lot processed through a fabrication facility. However, most of these data are observational (some would say 'happenstance') in nature, and are wrought with the problems of classical statistical analysis that experimental design procedures seek to avoid. Data Mining is loosely defined as an activity of extracting information from observational databases, wherein the goal is to discover hidden facts. One promising data mining technique is binary recursive partitioning. This technique is implemented in Classification And Regression Tree software by Salford Systems. This paper will explore the effective use of the CART/spl reg/ software tool to sift through the vast observational data generated in the production of microprocessors in the search of speed optimization opportunities. The procedures for using CART/spl reg/ to optimize microprocessor speed will be explained and demonstrated in several case studies.
Spectral aerosol extinction (SpEx): a new instrument for in situ ambient aerosol extinction measurements across the UV/visible wavelength range

Abstract. We introduce a new instrument for the measurement of in situ ambient aerosol extinction over the 300–700 nm wavelength range, the spectral aerosol extinction (SpEx) instrument. This measurement capability is envisioned to complement existing in situ instrumentation, allowing for simultaneous measurement of the evolution of aerosol optical, chemical, and physical characteristics in the ambient environment. In this work, a detailed description of the instrument is provided along with characterization tests performed in the laboratory. Measured spectra of NO2 and polystyrene latex spheres (PSLs) agreed well with theoretical calculations. Good agreement was also found with simultaneous aerosol extinction measurements at 450, 530, and 630 nm using CAPS PMex instruments in a series of 22 tests including nonabsorbing compounds, dusts, soot, and black and brown carbon analogs. SpEx measurements are expected to help identify the presence of ambient brown carbon due to its 300 nm lower wavelength limit compared to measurements limited to longer UV and visible wavelengths. Extinction spectra obtained with SpEx contain more information than can be conveyed by a simple power law fit (typically represented by Angstrom exponents). Planned future improvements aim to lower detection limits and ruggedize the instrument for mobile operation.
SpeedSpy: a mobile Web3D platform for visualizing broadband data

There are many variables affecting the Quality of Service for both wired and wireless broadband communications. We present SpeedSpy, a web-based application (HTML5 and X3DOM) that enables the 3D visualization of upload and download speeds for wired and wireless broadband in a given geo-location. SpeedSpy provides a mobile or desktop view into online public data from the United States Federal Communications Commission (FCC). Using the rich sensor and data capabilities of HTML5, such as geo-location services, access to on-board orientation sensors, and dynamic web queries, we have built a novel and flexible interface to view and interact with this high-dimensional geo-referenced data. SpeedSpy is hosted at http://www.cgit.vt.edu/broadband/speedspy
Naps: scalable, robust topology management in wireless ad hoc networks

Topology management schemes conserve energy in wireless ad hoc networks by identifying redundant nodes that may turn off their radios or other components while maintaining connectivity. We present Naps, a randomized topology management scheme that does not rely on geographic location information, provides exibility in the target density of waking nodes, and sends only a periodic heartbeat message between waking neighbors; thus it is implementable even on modest hardware. We formally analyze the connectivity of the waking graphs produced by Naps, showing that these graphs have nearly complete connectivity even at relatively low densities. We examine simulation results for a wide range of initial deployment densities and for heterogeneous and mobile deployments.
Coronavirus Neurovirulence Correlates with the Ability of the Virus To Induce Proinflammatory Cytokine Signals from Astrocytes and Microglia

The molecular and cellular basis of coronavirus neurovirulence is poorly understood. Since neurovirulence may be determined at the early stages of infection of the central nervous system (CNS), we hypothesize that it may depend on the ability of the virus to induce proinflammatory signals from brain cells for the recruitment of blood-derived inflammatory cells. To test this hypothesis, we studied the interaction between coronaviruses (mouse hepatitis virus) of different neurovirulences with primary cell cultures of brain immune cells (astrocytes and microglia) and mouse tissues. We found that the level of neurovirulence of the virus correlates with its differential ability to induce proinflammatory cytokines (interleukin 12 [IL-12] p40, tumor necrosis factor alpha, IL-6, IL-15, and IL-1β) in astrocytes and microglia and in mouse brains and spinal cords. These findings suggest that coronavirus neurovirulence may depend on a novel discriminatory ability of astrocytes and microglia to induce a proinflammatory response in the CNS.
In vivo system for the detection of low level activity barnase mutants

We report the design of a new tightly controlled barnase system which allows the existence of the barnase gene in host cells without a signal sequence. When expression of barnase is turned on by gene inversion in vivo, the lethal effect of barnase (or its mutants) is not compromised either by coexpression of its polypeptide inhibitor (barstar), or by extracellular secretion. This serves as a rapid, sensitive in vivo test for the detection of any very low residual activity of the barnase mutants. Active-site mutants His102Lys, Glu73Asp and Arg87Lys, and a mutant which greatly reduces the stability and yield of protein, Arg83Lys, produce enough activity to be detectable by this test. In contrast, when expressed on a secretion vector, these mutants do not yield detectable activity in a solution assay. Truly inactive mutants, such as those of His102 to Gly, Ala or Leu, were completely harmless when expressed in this system.
Convenient Large‐Scale Synthesis of Universal Solid Support

Abstract A simple, convenient large‐scale synthesis of a universal solid support useful for the synthesis of oligonucleotides is described.
Amygdala activation in the processing of neutral faces in social anxiety disorder: Is neutral really neutral?

Previous research has suggested that Social Anxiety Disorder (SAD) is associated with a tendency to interpret ambiguous social stimuli in a threatening manner. The present study used event-related functional magnetic resonance imaging to examine patterns of neural activation in response to the processing of neutral facial expressions in individuals diagnosed with SAD and healthy controls (CTLs). The SAD participants exhibited a different pattern of amygdala activation in response to neutral faces than did the CTL participants, suggesting a neural basis for the biased processing of ambiguous social information in SAD individuals.
The origin of risk aversion

Risk aversion is one of the most basic assumptions of economic behavior, but few studies have addressed the question of where risk preferences come from and why they differ from one individual to the next. Here, we propose an evolutionary explanation for the origin of risk aversion. In the context of a simple binary-choice model, we show that risk aversion emerges by natural selection if reproductive risk is systematic (i.e., correlated across individuals in a given generation). In contrast, risk neutrality emerges if reproductive risk is idiosyncratic (i.e., uncorrelated across each given generation). More generally, our framework implies that the degree of risk aversion is determined by the stochastic nature of reproductive rates, and we show that different statistical properties lead to different utility functions. The simplicity and generality of our model suggest that these implications are primitive and cut across species, physiology, and genetic origins.
XCo: Explicit Coordination for Preventing Congestion in Data Center Ethernet

Cluster-based storage systems increasingly use commodity communication technologies, such as Fibre Channel over Ethernet (FCoE), for accessing stored data over the network. Data is striped over multiple storage nodes, and storage traffic often shares the network with non-storage traffic. In such conditions, storage clients can experience severely degraded performance, such as TCP throughput collapse and network congestion due to competing network traffic. Furthermore, consolidation of multiple virtual machines (VMs) onto fewer physical nodes can worsen the performance of network storage systems. The root cause of this performance problem is that network traffic from multiple sources can cause transient overloads in the switch buffers. In this paper, we make the case that virtualization opens up a new set of opportunities to alleviate and solve such performance problems experienced by network storage in particular, and data center Ethernet in general. We present an architecture, called XCo, for explicit coordination of network traffic among VMs in a data center Ethernet that is inexpensive, fully transparent, currently feasible, and complementary to any switch-level hardware support. We present experimental evidence via proof-of-concept implementation and evaluation to support this claim and describe the challenges and opportunities in a complete solution.
The Depersonalization of Patients: A Profile Gleaned from Narratives

Occupational therapists who would better understand and advocate against depersonalization in health care can find specific references in narratives to the attitudes and behaviors that seem problematic. Patients argue that helpers fail to recognize that illness and disability are events charged with personal meaning. Instead of communicating with patients, helpers establish a distance that diminishes them. They withhold information in a manner that precludes hope, they use brusque manners, and they misuse their powers. Each of these behaviors seems unreasonable and impersonal, and each discourages patients. Together these narratives might inspire therapists to value interactive reasoning as central to practice, to recommit to their consideration of persons, and to enact a climate of caring.
Plasma wound treatment: From physics to animal models

Non-thermal treatment of wounds has been often mentioned as one of the most promising applications of plasma in medicine. Possibility of reducing bacterial load with plasma treatment has been suggested by some experiments on fresh meat, cadavers and living mice. Initial clinical results with human patients have also been reported. Animal experiments have been carried out to test toxicity of some plasma treatments. Possibility of enhanced growth of cells following some plasma treatment has been suggested through in-vitro experiments.
NEBIC: A Dynamic Capabilities Theory for Assessing Net-Enablement

We propose the Net-Enabled Business Innovation Cycle (NEBIC) as an applied dynamic capabilities theory for measuring, predicting, and understanding a firm's ability to create customer value through the business use of digital networks. The theory incorporates both a variance and process view of net-enabled business innovation. It identifies four sequenced constructs: Choosing new IT, Matching Economic Opportunities with technology, Executing Business Innovation for Growth, and Assessing Customer Value, along with the processes and events that interrelate them as a cycle. The sequence of these theorized relationships for net-enablement (NE)Â¹ asserts that choosing ITprecedes rather than aligns with corporate strategy. The theory offers a logically consistent and falsifiable basis for grounding research programs on metrics of net-enabled business innovation.