cssi/SciSciGPT-SciSciNet huggingface dataset:
Fundamental Limits to Wavefront Sensing in the Submillimeter

With the advent of large-format submillimeter wavelength detector arrays, and a new 25 m diameter submillimeter telescope under consideration, the question of optimal wavefront sensing methods is timely. Indeed, not only should bolometric array detectors allow the use of a variety of wavefront sensing techniques already in use in the optical/infrared, but in some cases it should actually be easier to apply these techniques because of the more benign temporal properties of the atmosphere at long wavelengths. This paper thus addresses the fundamental limits to wavefront sensing at submillimeter wavelengths, in order to determine how well a telescope surface can be measured in the submillimeter band. First several potential measurement approaches are discussed and compared. Next the theoretical accuracy of a fringe phase measurement in the submillimeter is discussed. It is concluded that with Mars as the source, wavefront sensing at the micron level should be achievable at submillimeter wavelengths in quite reasonable integration times.
Evaluation of Narrow‐Row Corn Forage in Field‐Scale Studies

Some dairy producers in the northeastern USA grow corn (Zea mays L.) in narrow rows at high plant densities and N fertility. We evaluated first-year, second-year, and continuous corn in field-scale studies at 0.76- and 0.38-m row spacings at recommended densities (85 000 plants ha -1 ) and N fertility (165 kg ha -1 ) and at 0.38-m spacing at high densities (100 000 plants ha -1 ) and N fertility (=225 kg ha -1 ) in 1998, 1999, and 2000 to determine if narrow-row corn forage requires high densities and N fertility for optimum yield and quality. Narrow-row corn at high vs. recommended densities and N fertility had similar soil NO 3 -N concentrations in the upper 0.3-m depth and whole-plant N concentrations at the sixth leaf stage of corn (V6) as well as similar ear-leaf N concentrations at silking in eight of the nine site-year comparisons. All treatments were above critical concentrations for soil NO 3 -N concentrations (>25 mg kg -1 ), whole-plant N concentrations (>35 g kg -1 ), and ear-leaf N concentrations (>25 g kg -1 , except in the cool 2000 season). Consequently, narrow-row corn at high vs. recommended densities and N fertility had similar dry matter yield and quality in eight site-year comparisons. Furthermore, narrow-row corn at high vs. recommended densities and N fertility had greater residual soil NO 3 -N concentrations in three site-year comparisons. We recommended that dairy producers in the northeastern USA grow narrow-row corn forage at recommended plant densities and N fertility.
A 58-Year-Old Man With Shortness of Breath, Ascites, and Leg Edema

The patient is a 58-year-old African American man with past medical history significant for a positive purified protein derivative (PPD) 2 years ago. No treatment was given. He was in his usual state of good health until 6 weeks before admission, when he became aware of breathlessness on mild exertion. Over the ensuing 4 weeks, he noted progressive fatigue; swelling of his lower extremities, particularly on standing; and increasing abdominal girth. His exercise tolerance decreased until he could no longer walk a single city block comfortably. He denied chest pain, palpitations, orthopnea, paroxysmal nocturnal dyspnea, and nocturia. He also denied fever and significant weight loss but did complain of occasional night sweats. The patient was treated with furosemide 20 mg/d without improvement. His family history was remarkable for a father and a brother who died of unknown heart disease in their 50s. He was married with one healthy son. He immigrated to the United States from St Croix 10 years before admission and worked as a mailroom clerk. He had no significant travel history, was a lifetime nonsmoker, and drank alcohol only socially. Physical examination revealed an obese African American man in mild respiratory distress. He was afebrile. The heart rate was 80 bpm and regular, and his blood pressure was 120/70 mm Hg. Respiratory rate was 20 breaths per minute. His head was normal except for ill-defined hyperpigmentation periorbitally and bitemporally. His neck was supple without lymphadenopathy. Carotid upstrokes were normal. Jugular venous pressure was estimated at 14 cm water, and there was a Kussmaul's sign; prominent x and y descents were noted. The thyroid gland was normal. There were no gynecomastia and no palpable lymph nodes anywhere. The lungs were clear. Cardiac examination showed a nondisplaced point of maximal intensity and normal S1 and S2. There …
RENORMALIZABLE MASSIVE VECTOR-MESON THEORY: PERTURBATION THEORY OF THE HIGGS PHENOMENON.

We establish that the Abelian gauge theory first considered by Higgs in which the gauge vector boson acquires a finite mass due to the spontaneous breakdown of symmetry is renormalizable, in the sense that the Bogoliubov-Parasiuk-Hepp program can be executed in such a way that the Ward-Takahashi identities are satisfied. This paper contains the global study of the Ward-Takahashi identities and low-energy theorems of the model. We show that the Goldstone boson and the scalar excitation of zero mass associated with the Landaugauge vector propagator are unphysical, and disappear from the $S$ matrix.
UPTAKE OF FE59 BY SPLEENS OF LETHALLY IRRADIATED MICE GIVEN ISOLOGOUS BONE MARROW.

An approach to a study of radiation effects on hematopoietic cells, as well as in vitro protection and recovery of irradiated cells, was made in terms of their ability to transplant and proliferate in lethally irradiated mice. The system works reasonably well as a means of estimating in vitro radiosensitivity and protection of mouse bone marrow when 30-day survival of the irradiated recipients is used as an endpoint. Male (C3H x C57BL)F/sub 1/ mice were exposed to 950 r of 250-kv whole-body x rays. The next day ( approximates 24 hr) these mice were injected intravenously with graded doses of isologous bone marrow cells. Seven days later, 0.2/ mu C of /sup 56/Fe was injected intraperitoneally, and 24 hr later the spleen was removed and counted in a welltype scintillation detector. When results were expressed as percentage-uptake of injected /sup 59/Fe, there was a linear response with increasing marrow doses between 0.050 and 0.4 x 10/sup 6/ cells. Over the same range, 30-day survival of lethally irradiated mice increases from a low level to essentially l00% for many strains. It is anticipated that the method will be sensitive enough to study modification of in vitro radiation injury to marrow cells.more » (auth)« less
Calcium uptake by cytochrome oxidase vesicles

Cytochrome oxidase vesicles (COV) are well known for their properties of respiratory control and energydependent pH gradient and membrane potential formation [ 1,2]. This generation of protonmotive force in COV has been used to drive the formation of ATP in a reconstituted system of oxidative phosphorylation [3-51. In addition, energized COV in the presence of valinomycin have been used to study potassium uptake driven by a membrane potential which was generated by electron transport [ 1,6]. Study of ion transport in COV has been limited by the sensitivity of available ion-specific electrodes. However, the recent aggregation technique [7] for the separation of proteoliposomes from suspending media allows quantitation of very small amounts of ion uptake in vesicles when radioactively-labelled ions are used. Using this separatory technique, energydependent uptake of Ca’+ in COV has been observed and is reported here. While specific interaction of Ca2+ with cytochrome oxidase has been noted in the past [8-l 11, and a subfractionated preparation of cytochrome oxidase has been found to possess specific Ca2’ ionophoric properties [12-l 51, transport of Ca2+ in an energy-dependent manner, mediated by cytochrome oxidase has not been reported. Fry and Green [ 151 have described increased passive permeability to Ca2+ in liposomes reconstituted with subfractionated preparations of cytochrome oxidase, particularly subunit I. Whether the Ca2+ transporting properties of cytochrome oxidase have any relationship
SELECTIVE CLEAVAGE AT THE SINGLE TRYPTOPHAN RESIDUE IN BOVINE SOMATOTROPIN BY 2‐(2‐NITROPHENYLSULFENYL)‐3‐METHYL‐3‘‐BROMOINDOLEMINE

SELECTIVE CLEAVAGE AT THE SINGLE TRYPTOPHAN RESIDUE IN BOVINE SOMATOTROPIN BY 2-(2-NITROPHENYLSULFENYL)-3-METHYL-3′-BROMOINDOLEMINE The single tryptophan residue at position 86 in bovine somatotropin has been cleaved by the use of 2-(2-nitrophenylsulfenyl)-3-methyl-3′-bromoindolemine. This reaction was carried out with native bovine growth hormone as well as its reduced and alkylated derivative. When performed on the intact hormone, followed by the reduction and alkylation of the disulfides to liberate the two fragments, the cleavage reaction yielded the fragment containing residues 87–191 in a monomeric state. The other fragment, containing residues 1–86, could only be obtained in a highly aggregated form admixed with other material. When the cleavage reaction was carried out on the reduced and alkylated hormone, both the N-terminal fragment of reduced-carbamidomethylated bovine somatotropin as a monomer and the C-terminal fragment as a dimer were obtained in 35–40% yield. Since the cleavage reaction also oxidized methionine to methionine sulfoxide, the sulfoxides were reduced back to the methionine with N-methylmercapto acetamide. In this manner the following new derivatives and fragments of bovine somatotropin have been prepared: completely reduced and alkylated hormone, reduced and alkylated hormone with its methionines and tryptophan oxidized, reduced and alkylated hormone with its tryptophan oxidized, the N-terminal fragment of the hormone containing residues 1–86 with its methionine and tryptophan oxidized, the C-terminal fragment containing residues 87–191, both with its methionines oxidized and in their native state. The chemical and physical properties of these derivatives and fragments have been determined. Biological activity in the rat tibia was found to be negligible for all derivatives and fragments.
Electromechanical Mode Estimation Using Recursive Adaptive Stochastic Subspace Identification

Measurement based algorithms for estimating low-frequency electromechanical modes serve as useful practical methods to monitor the modal properties of power system oscillations in real-time. This paper proposes a recursive adaptive stochastic subspace identification (RASSI) algorithm for online monitoring of power system modes using wide-area synchrophasor data. The proposed method gives an online estimation of mode frequency and damping ratio as well as mode shapes using multi-channel measurement data. It exploits both the accuracy of subspace identification and fast computational capability of recursive methods. An adaptive method is proposed to enable fast tracking of modal evolution under poorly damped conditions together with low estimation variance under quasi-steady-state conditions. The algorithms are tested using simulated data from Kundur two-area test power system as well as measured data from real systems.
Bifurcation, symmetry and the influence of an electric field on chemical dissipative structures

Abstract The influence of a static electric field on the bifurcation of chemical dissipative structures is analyzed through the consideration of symmetry. It is shown how group theory can be used to obtain the bifurcation equations.
Galvanomagnetic Properties of Gallium at Low Temperatures

The galvanomagnetic properties of gallium single crystals in a transverse magnetic field have been investigated at helium temperatures, 77\ifmmode^\circ\else\textdegree\fi{}K and 290\ifmmode^\circ\else\textdegree\fi{}K. At 290\ifmmode^\circ\else\textdegree\fi{}K and 77\ifmmode^\circ\else\textdegree\fi{}K the galvanomagnetic properties are described according to a set of phenomenological equations, these properties then being specified by the tensors in the equations. This formalism breaks down at helium temperatures, where an apparent reduction in crystal symmetry occurs; the number of coefficients specifying the magnetoresistivity tensor according to crystal symmetry considerations is insufficient for a description of the observed galvanomagnetic properties. The results at helium temperatures can be qualitatively understood in terms of the recent fundamental theory of galvanomagnetic effects of Lifshitz, Azbel', and Kaganov which is based on considerations involving the topology of the Fermi surface. The anomaly of a marked displacement of the maximum in the Hall rotation curve at 77\ifmmode^\circ\else\textdegree\fi{}K and 290\ifmmode^\circ\else\textdegree\fi{}K is accounted for in detail according to the phenomenological formalism, on the basis of the anisotropy of the Hall coefficients at those temperatures combined with a small displacement of crystallographic axes from specimen axes. Well-defined oscillations in the magnetoresistance and Hall effects, superposed on the monotonic variation of the effects, have been observed for every crystal orientation studied. The general characteristics of these oscillations are the same as those in the diamagnetic susceptibility (the de Haas-van Alphen effect).
Modulation of swimming speed in the pteropod mollusc,Clione limacina: Role of a compartmental serotonergic system

In locomotory systems, the central pattern generator and motoneuron output must be modulated in order to achieve variability in locomotory speed, particularly when speed changes are important components of different behavior acts. The swimming system of the pteropod mollusc Clione limacina is an excellent model system for investigating such modulation. In particular, a system of central serotonergic neurons has been shown to be intimately involved in regulating output of the locomotory pattern generator and motor system of Clione. There are approximately 27 pairs of serotonin-immunoreactive neurons in the central nervous system of Clione, with about 75% of these identified. The majority of these identified immunoreactive neurons are involved in various aspects of locomotory speed modulation. A symmetrical cluster of pedal serotonergic neurons serves to increase wing contractility without affecting wing-beat frequency or motoneuron activity. Two clusters of cerebral cells produce widespread responses that lead to an increase in pattern generator cycle frequency, recruitment of swim motoneurons, activation of the pedal serotonergic neurons and excitation of the heart excitor neuron. A pair of ventral cerebral neurons provides weak excitatory inputs to the swimming system, and strongly inhibits neurons of the competing whole-body withdrawal network. Overall, the serotonergic system in Clione is compartmentalized so that each subsystem (usually neuron cluster) can act independently or in concert to produce variability in locomotory speed.
Condition monitoring of a thermally aged elastomer by 1H-NMR T2 relaxation measurements of solvent-swelled samples

The aging of polymers is often monitored by mechanical property measurements such as those of Young's modulus or tensile elongation at break; new methods are required, however, in situations where traditional mechanical methods cannot be employed. A hydroxy-terminated polybutadiene/isophorone diisocyanate elastomer is commonly used as a propellant binder. The thermal degradation of the binder is believed to be an important parameter governing the performance of the propellant. Classical mechanical methods cannot be used to monitor the condition of this material when it has been aged in situ as a highly dispersed binder. In this study, the 1H-NMR spin-spin relaxation times, T2, of solvent-swelled samples decreased substantially as thermally induced oxidation led to additional crosslinking. A time–temperature superposition analysis of the relaxation times was performed on samples that had been aged at temperatures ranging from 50 to 125°C. The acceleration factors derived from the relaxation measurements agreed with those reported earlier for tensile elongation at break and oxygen consumption. The dependence of T2 on tensile elongation at break was independent of the temperature at which the sample was aged. A shortened version of the experiment, requiring only two spin-echo delay times, is presented. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 3636–3641, 2002
Photoelectron spectroscopy of carbonyls: Benzoic acid and its derivatives☆

Abstract The ultraviolet photoelectron spectra of benzoic acid and 20 of its derivatives are presented. The low-energy regions of these spectra are “deconvoluted” and assigned using chemical substitution effects.
Concerted rearrangement versus heterolytic cleavage in anionic [2,3]- and [3,3]-sigmatropic shifts. A DFT study of relationships among anion stabilities, mechanisms, and rates.

The anionic [2,3] sigmatropic Wittig rearrangements of deprotonated 4-hetera-1-pentenes and the anionic [3,3] sigmatropic Cope rearrangements of 3-substituted-1,5-hexadienes were explored by using density functional theory calculations. While the deprotonated anionic 3-hydroxy-1,5 hexadiene (2a), 3-thiohydroxy-1,5-hexadiene (2c), and 3-formamidyl-1,5-hexadiene (2d) Cope substrates undergo concerted rearrangements, the deprotonated anionic 3-amino-1,5-hexadiene (2b) and 3-methyl-1,5-hexadiene (2e) Cope substrates follow nonconcerted cleavage/recombination pathways. We have also found that the gas-phase Wittig (1a), aza-Wittig (1b), and carba-Wittig (1c) reactions proceed via nonconcerted cleavage/recombination pathways. These results are compared with previous results on the Cope rearrangements of deprotonated anionic 3-hydroxy-1,5-hexadiene and 3-amino-1,5-hexadiene anions. A previously established model that heterolytic and homolytic bond dissociation energies can be used to predict how anionic amino- an...
Midline forehead flaps in nasal reconstruction

There are a variety of midline forehead flaps available, and how these are used is limited only by the ingenuity of the surgeon. An additional fact which is significant in terms of reconstruction and patient satisfaction is that midline donor site scars heal well. It is rare to have one of these spread or to become hypertrophic, regardless of the type of skin. These were initially popularized by Esser [1]. As with all flaps, those from the forehead can be used as local pedicled or island flaps. Due to the laxity of the midline in most people the closure of wide defects is almost always possible. This can be further increased by the use of tissue expansion. Perhaps one of the most important characteristics of the forehead skin is that it is similar in color and texture to that of the nose. To understand the safe use of the forehead as a flap donor site the nature of the blood supply to the forehead must be understood. It is the vascular anatomy which determines the important characteristics of the forehead flap, namely its length, its width and where the base is situated. 1. Medial supply: the dorsal nasal artery comes from the ophthalmic artery which is from the internal carotid. 2. Lateral supply: the angular artery passes under the levator labii superioris nasi. It comes from the facial artery which in turn originates from the external carotid artery. 3. Additional lateral supply: there is a component from the lateral supratrochlear artery from the ophthalmic artery which comes from the internal carotid. The venous drainage is by means of the ophthalmic veins which end up in the cavernous sinuses. The supratrochlear vein connects to the angular vein. Innervation is from the supratrochlear nerve. As a result of our clinical investigations and some recent cadaver studies, there appears to be a consistent area of anastomoses between the frontal and the paranasal vascular regions [2] (Fig. 1). The significance of this is that a midline flap can be made very long since it can be based low down on the paranasal area at the level of the medial canthus. Having established this fact, midline forehead flap design is easy and the length is considerable; it can reach the tip of the nose and beyond. What has not, as yet, been completely established is the width of the flap which can be taken from the central forehead. It is probably related only to the ability to close the transverse defect. Basing the flap on the glabellar area, which is classic teaching and trying to reconstruct the tip and columella will end in disaster either by loss of flap or by forming a short nose. A flap based on the medial canthal area is safe and will comfortably reach the base of the columella without tension, no matter how long or large the nose is. No longer do we end up with a short upturned nose which, in the male or the older female, is a disaster (Figs. 2, 3).
Marxism and Humanism

Criticizes the view that ethical judgements are completely separate from facts and theories in the social sciences. On the contrary, it argues that no project can be initiated nor any facts collected without some goal in mind and no important statement can be made in the social sciences without involving an ethical view. An ethical framework is one part of every social scientist′s paradigm (using the word in the sense of Thomas Kuhn) and we always work within that paradigm using those ethical values ‐even when social scientists claim to be purely “objective” with no ethical values in their work. Argues that Marx had an ethical view based not on any supernatural entity or imperative, but on the needs and desires of all of humanity. Marxist social science, like Institutionalist social science, is based on the view that every social science project must involve both factual research and an ethical framework.
MORAL THEOLOGY AND THE MODERN CATHOLIC COLLEGE

Moral theology must run hard and fast to catch up with the moral problems posed by the exponential curves of our explosions
Mononuclear phagocyte-derived interleukin-10 suppresses the innate pulmonary granuloma cytokine response in aged mice

Granulomas are sequestration responses observed in a wide variety of clinical conditions, including mycobacterial infection. We previously reported impaired adaptive, Th1 cell-mediated pulmonary granuloma formation in response to bead-immobilized Mycobacterium bovis-purified protein derivative in aged mice. To reveal determinants of age-related immune deficits, the present study examined the effect of aging on early innate stage pulmonary granuloma formation. Aged mice formed more neutrophil-rich innate granulomas with augmented CXCL2 expression followed by a pattern of rapid decay of tumor necrosis factor-α, interleukin (IL)-6, CCL3, and CXCL2. This was associated with enhanced IL-10 expression. Blockade of IL-10 signaling with anti-IL-10 receptor antibody reversed the age-related decay. Intracellular flow cytometric analysis revealed that CD11b+Gr-1+/− mononuclear phagocytes were the primary leukocyte sources of IL-10 in lungs, and their numbers were increased in aged mice. When exposed to purified protein derivative in vitro, young and old CD11b+Gr-1+/− mononuclear phagocytes from blood or lung had comparable IL-10 expression, suggesting in vivo signals in the aged environment enhanced the number of IL-10-producing cells in the aged lung. Our findings reveal a novel mechanism of age-associated IL-10 mediated pulmonary immune suppression with the potential to alter downstream adaptive immunity.
Color experience in blindsight

Blindsight, the ability to blindly discriminate wavelength and other aspects of stimuli in a blind field, sometimes occurs in people with lesions to striate (V1) cortex. There is currently no consensus on whether qualitative color information of the sort that is normally computed by double opponent cells in striate cortex is indeed computed in blindsight but doesn’t reach awareness, perhaps owing to abnormal neuron responsiveness in striate or extra-striate cortical areas, or is not computed at all. The existence of primesight, the experience of colored afterimages in blindsight, has been taken to suggest that qualitative color information is computed either in pre-striate or striate cortical areas but is not broadcast to working memory. I argue here that a recent study in which color phosphenes were induced in a blindsighter using bilateral transcranial magnetic stimulation indicates that computations necessary for conscious color vision are lost in blindsight. Owing to this loss, the neural responsivene...
Spring and aufeis (icing) hydrology in Brooks Range, Alaska

[1] Remote sensing studies and field hydrometeorological and geophysical investigations were employed to characterize several aufeis fields in the Brooks Range, Alaska. Geochemical studies were undertaken together with field hydrological measurements to better understand the chemical and thermal properties of stream base flow (groundwater spring) that contributes to winter aufeis development. The spring water temperature was measured at several major aufeis fields using data loggers throughout the year. Aufeis is an important water storage component in the Arctic and influences local ecology and geomorphology. Synthetic aperture radar (SAR) is a useful and sensitive sensor for aufeis detection and for estimating the total volume of storage as well as freeze/thaw conditions. The SAR analysis indicated that the volume of aufeis formed in winter is 27–30% of the annual groundwater discharge in the Kuparuk River. Visible and near-IR satellite imagery indicated many of the high-discharge springs (more than 10–1000 1/s) and aufeis fields are centered around an elevation of 600 m a.s.l. in limestone areas with glacial morphology. Geomorphological investigations indicate that many of springs have continually existed from at least the last glaciation. Microwave data (SAR), thermal infrared, short wave infrared, and visible and near-IR bands were all used to observe the growth, decay, and distribution of aufeis deposits. The remotely sensed data indicate that the distribution of the aufeis deposits today is nearly the same as it was in past colder periods; this was mainly determined by mapping the distributed carbonate precipitates. Also, spring water temperatures and discharge volumes are predictable from the aufeis field size using remotely sensed techniques.
Specimen biasing to enhance or suppress secondary electron emission from charging specimens at low accelerating voltages

Biasing of the specimen is shown to produce improved images in the scanning electron microscope at low beam energies (0.8–2.5 keV) when charging effects (induced by the primary electron beam), topographic effects, or detector shadowing effects would otherwise be present. Examples of such improvement are given for gallium arsenide field-effect transistors (positive charging), patterned photoresist layers on silicon wafers (negative charging and shadowing in contact holes), fractured polymethylmethacrylate (negative charging), polyethylene wrapper material (positive charging), and polished diamond tools (positive charging). It is concluded that specimen biasing may be a simpler and more convenient way to achieve some of the advantages of the converted backscattered secondary electron (CBSE) technique for imaging, but without some of the fundamental disadvantages of that technique. Characterization of this backscattered electron-derived image bears further investigation for possible metrological applications.
Comparative flow characteristics of selected dental materials with emphasis on thixotropic behavior.

Abstract Flow behavior of selected impression materials, dental cement liquids and fluoride gels were measured using a unique cup and bod viscometer. Programmable functions of the instrument allowed shear stress measurement during increasing and decreasing shear rates. Shear-dependent and time-dependent properties of plastic, pseudoplastic and thixotropic behavior were evaluated for these materials. The thixotropic index was also used to compare these materials. The impression materials tested showed pseudoplastic and thixotropic behavior, while the dental cements showed very little pseudoplastic or thixotropic behavior. The fluoride gels showed essentially plastic yield with minimal thixotropy.
Pyramid computer solutions of the closest pair problem

Given an N × N array of 0s and 1s, the closest pair problem is to determine the minimum distance between any pair of ones. Let D be this minimum distance (or D = 2N if there are fewer than two 1s). Two solutions to this problem are given, one requiring O(log(N) + D) time and the other O(log(N)). These solutions are for two types of parallel computers arranged in a pyramid fashion with the base of the pyramid containing the matrix. The results improve upon an algorithm of Dyer that requires O(N) time on a more powerful computer.
Does size matter in platelet production

Platelet (PLT) production represents the final stage of megakaryocyte (MK) development. During differentiation, bone marrow MKs extend and release long, branched proPLTs into sinusoidal blood vessels, which undergo repeated abscissions to yield circulating PLTs. Circular-prePLTs are dynamic intermediate structures in this sequence that have the capacity to reversibly convert into barbell-proPLTs and may be related to “young PLTs” and “large PLTs” of both inherited and acquired macrothrombocytopenias. Conversion is regulated by the diameter and thickness of the peripheral microtubule coil, and PLTs are capable of enlarging in culture to generate barbell-proPLTs that divide to yield 2 smaller PLT products. Because PLT number and size are inversely proportional, this raises the question: do macrothrombocytopenias represent a failure in the intermediate stages of PLT production? This review aims to bring together and contextualize our current understanding of terminal PLT production against the backdrop of human macrothrombocytopenias to establish how “large PLTs” observed in both conditions are similar, how they are different, and what they can teach us about PLT formation. A better understanding of the cytoskeletal mechanisms that regulate PLT formation and determine PLT size offers the promise of improved therapies for clinical disorders of PLT production and an important source of PLTs for infusion.
Run-Time Analysis for Atomicity

Abstract Writing and debugging concurrent (shared-variable) programs is notoriously difficult. This motivated the development of numerous static analysis and run-time analysis techniques designed to (help) ensure that concurrent programs satisfy common correctness requirements for concurrent programs, such as absence of race conditions and absence of deadlocks. This paper focuses on another common correctness requirement for concurrent programs, namely, atomicity, which requires that any set of concurrent invocations of designated procedures is equivalent to performing those invocations serially in some order. Run-time analysis algorithms for detecting violations of atomicity are presented. The algorithms vary in cost and precision.
He diffusion and (U–Th)/He thermochronometry of zircon: initial results from Fish Canyon Tuff and Gold Butte

To evaluate the potential of (U–Th)/He geochronometry and thermochronometry of zircon, we measured He diffusion characteristics in zircons from a range of quickly and slowly cooled samples, (U–Th)/He ages of zircons from the quickly cooled Fish Canyon Tuff, and age-paleodepth relationships for samples from 15 to 18 km thick crustal section of the Gold Butte block, Nevada. (U–Th)/He ages of zircons from the Fish Canyon Tuff are consistent with accepted ages for this tuff, indicating that the method can provide accurate ages for quickly cooled samples. Temperature-dependent He release from zircon is not consistent with thermally activated volume diffusion from a single domain. Instead, in most samples apparent He diffusivity decreases and activation energy (E_a) increases as cycled step-heating experiments proceed. This pattern may indicate a range of diffusion domains with distinct sizes and possibly other characteristics. Alternatively, it may be the result of ongoing annealing of radiation damage during the experiment. From these data, we tentatively suggest that the minimum E_a for He diffusion in zircon is about 44 kcal/mol, and the minimum closure temperature (T_c, for a cooling rate of 10 °C/myr) is about 190 °C. Age–paleodepth relationships from the Gold Butte block suggest that the base of the zircon He partial retention zone is at pre-exhumation depths of about 9.5–11 km. Together with constraints from other thermochronometers and a geothermal gradient derived from them in this location, the age–depth profile suggests a He T_c of about 200 °C for zircon, in reasonable agreement with our interpretation of the laboratory measurements. A major unresolved question is how and when radiation damage effects become significant for He loss from this mineral.
Internal Dynamics of Green Fluorescent Protein

A 1 ns molecular dynamics simulation was performed to study the dynamic behavior of wild-type green fluorescent protein from Aequorea victoria. We find the protein to be remarkably rigid, both overall, because the cylindrical β-barrel provides a stable framework, but also on an atomic level in the immediate surrounding of the chromophore. Here, a tight H-bond network is formed mainly involving six internal water molecules. The perfect barrel is interrupted only between β-strands 7 and 8 where contact is made via side chain interactions, and we investigated the dynamic behavior of this region in detail. After ca. 320 ps of simulation, an arginine residue, initially sticking out into solution, folded over the cleft to form a H-bond with a backbone oxygen atom on the opposite strand. This contact appears important for stabilization of the overall protein architecture.
Searching for stationarity: Purchasing power parity under the current float

Abstract Using panel data methods, we investigate long-run purchasing power parity by testing for unit roots in real exchange rates of industrial countries under the current float. The evidence against the unit root hypothesis is stronger for larger than for smaller panels, for monthly than for quarterly data, and when the German mark, rather than the United States dollar, is used as the base currency. While we find that accounting for serial correlation considerably weakens the evidence against the unit root null, the results as a whole are consistent with long-run purchasing power parity.
Transiency, test scores, and the public: One school district's story

Abstract Research documents that transient students who change schools frequently oftensuffer from low academic achievement. This article investigates standardized group measures by disentangling elementary achievement scores. Located in a highly transient area outside of Philadelphia, Pennsylvania, Main Street School had their fifth grade Pennsylvania System of School Achievement scores disentangled in an effort to analyze their transient students' levels of achievement. The data suggest that the higher the rate of mobility the lower the academic test scores, leading one to believe learning is occurring at a faster rate for those students who have remained in a stable educational environment. Conclusions based on the present data are shared and recommendations for curricular and methodological changes are provided.
Health claims and consumers’ behavioral intentions: The case of soy-based food

Abstract This research evaluates the impact of two soy-specific health claims (highlighting FDA approval along with scientific results and simply describing scientific results) on stated behavioral intentions toward soy-based food using a survey administered by Ipsos-Observer to a nationally representative web panel in the summer of 2007. Our research design randomly assigned respondents to a health claim. Three ordered probit models (non-soy users; infrequent soy users; regular soy users) show that non-soy users and infrequent soy users who were exposed to either FDA health claim or general health claim are significantly more likely to eat soy-based food products. FDA or general health claim, however, did not change the behavioral intentions of regular soy users. These results suggest that soy consumption status moderates the impacts of health claims on behavioral intentions. However, the impact of FDA health claim did not differ from that of general health claim, indicating that the word ‘FDA’ did not add any additional information to consumers beyond the general health claim.
Perspectives of relativistic quantum chemistry: the negative energy cat smiles

Given the remarkable advances in relativistic quantum chemistry, some conceptual aspects still remain to be addressed. Among others, the role of negative energy states (NES) in electron correlation and other properties requires most attention. Based on critical assessments of the configuration space (CS), no-photon (and no-time) Fock space (FS) and quantum electrodynamics (QED) approaches, it is concluded that only QED provides the correct prescription for the contributions of NES to correlation, while both CS and FS give rise to wrong results. This essentially means that one should work either with the no-pair approximation (which has an intrinsic error of order (Zα)3) or with QED. Whether a consistent relativistic many-electron theory does exist in between remains an open question. Even under the no-pair approximation, there still exists an issue arising from that the no-pair Hamiltonian is incompatible with explicitly correlated methods. It turns out that this can nicely be resolved by introducing the concept of extended no-pair projection. Apart from these take-home messages, other immediate prospects of relativistic quantum chemistry are also highlighted for guiding future developments and applications.
Comparative study of sequence-dependent hybridization kinetics in solution and on microspheres.

Hybridization kinetics of DNA sequences with known secondary structures and random sequences designed with similar melting temperatures were studied in solution and when one strand was bound to 5 μm silica microspheres. The rates of hybridization followed second-order kinetics and were measured spectrophotometrically in solution and fluorometrically in the solid phase. In solution, the rate constants for the model sequences varied by almost two orders of magnitude, with a decrease in the rate constant with increasing amounts of secondary structure in the target sequence. The random sequences also showed over an order of magnitude difference in the rate constant. In contrast, the hybridization experiments in the solid phase with the same model sequences showed almost no change in the rate constant. Solid phase rate constants were approximately three orders of magnitude lower compared with the solution phase constants for sequences with little or no single-stranded structure. Sequences with a known secondary structure yielded solution phase rate constants as low as 3 × 103 M−1 s−1 with solid phase rate constants for the same sequences measured at 2.5 × 102 M−1 s−1. The results from these experiments indicate that (i) solid phase hybridization occurs three orders of magnitude slower than solution phase, (ii) trends observed in structure-dependent kinetics of solution phase hybridization may not be applicable to solid phase hybridization and (iii) model probes with known secondary structure decrease reaction rates; however, even random sequences with no known internal single-stranded structure can yield a broad range of reaction rates.
Variability in the Inverse-Compton X-Ray Flux from the Jet in Quasar 3C 345

We present the results of the -rst systematic study of correlated variability in the X-ray emission and the parsec-scale radio structure of the "" superluminal II quasar 3C 345. This quasar is one of a class of core-dominated Nat-spectrum radio sources that are believed to emit X-rays via the synchrotron self- Compton process. By studying its variability in X-rays, we can test this hypothesis for 3C 345 by model- ing the expected inverse-Compton Nux from the parsec-scale jet, using parameters derived from multifrequency VLBI imaging. Since the predicted X-ray Nux is very sensitive to the physical parameters of the compact radio-emitting regions, a study of variability, with quasi-simultaneous X-ray and VLBI data, is of particular interest because it is less sensitive to assumptions in the adopted model. The soft X-ray Nux density of 3C 345 was observed by the ROSAT PSPC instrument at seven epochs during 1990E1993, during which time its Nux density varied by a factor of 2, but with no change in spectral index. The X-ray points closely track the high-frequency radio Nux light curve. Using a series of VLBI images, we followed the time evolution of spectral shapes and angular sizes of the nucleus and the strongest jet component "" C7,II at a distance of ^0.5 mas (2 pc) from the nucleus, and derived physical parameters for the components. We -nd that component C7, not the nucleus, is the dominant generator of the observed X-rays during 1992E1993. For the nucleus, we applied the inhomogeneous-jet model of Koe nigl and found -nd that it underpredicts the X-ray Nux for any plausible combination of physical parameters derived from observation. A homogeneous sphere, with Nux density peaking at a few GHz, is adequate for modeling the evolution of C7. This sphere model requires that C7 dominated the X-ray emission, unless its Doppler factor is ?10. This contrasts with the situation at epoch 1990.55, for which comparable data (Unwin et al. 1994) showed that the nucleus and C5 (the dominant jet feature at that time) both contributed to the X-ray emission. We discuss the lack of detectable c-rays from 3C 345 in relation to other c-ray loud blazars with which it shares many observational properties. Combining the superluminal speed (from VLBI) and Doppler factor deduced from the synchrotron self-Compton calcu- lation, we solve for the jet kinematics at the position of C7, and we -nd that the jet bends away from the line of sight (from h ^ 2i to ^10i) and accelerates from c ^ 5 to over the range of (deprojected)
Preparation of Hydrogen Passivated Silicon for UHV-CVD Low Temperature Epitaxy

A critical step for successful growth of ultra-high vacuum chemical vapor deposition (UHV-CVD) epitaxial silicon films at low temperatures is the preparation and maintenance of a hydrogen passivated surface. A final 10:1 HF dip has been shown to provide a robust and extremely clean substrate for this purpose; interfacial oxygen and carbon levels of less than 1 × 10{sp13} atoms/cm{sp2} and low levels of structural defects are routinely observed after epitaxial growth. In this work, our understanding of the Si (100) hydrogen passivated surface is reviewed with emphasis on its stability to air and moisture exposure. Additionally, in an effort to reduce interfacial contamination levels even further and explore clusterable processes, other precleaning chemistries such as high pH NH4F and vapor HF have also been evaluated. While surface analysis measurements suggest that the NH4F preparation should be as good or better than the HF dip, the epitaxial film defect density is higher by several orders of magni- tude than for the dilute HF preparation. The vapor HF process, while potentially clusterable and therefore desireable, has generally not provided hydrogen passivated surfaces that are clean enough for this application.
A Deeper Statistical Examination of Arrival Dates of Migratory Breeding Birds in Relation to Global Climate Change

Using an 18-year dataset of arrival dates of 65 species of Maine migratory breeding birds, I take a deeper view of the data to ask questions about the shapes of the distribution. For each year, most species show a consistent right-skewed pattern of distribution, suggesting that selection is stronger against individuals that arrive too early compared to those that arrive later. Distributions are consistently leptokurtic, indicating a narrow window of optimal arrival dates. Species that arrive earlier in the spring show higher skewness and kurtosis values. Nectarivorous species showed more pronounced skewness. Wintering area did not explain patterns of skewness or kurtosis. Deviations from average temperatures and the North Atlantic Oscillation index explained little variation in skewness and kurtosis. When arrival date distributions are broken down into different medians (e.g., 5% median and 75% median), stronger correlations emerge for portions of the distribution that are adjacent, suggesting species fine-tune the progress of their migration. Interspecific correlations for birds arriving around the same time are stronger for earliest migrants (the 25% median) compared to the true median and the 75% median.
Neonatal hypothyroidism and goiter in oneinfant of each of two sets of twins due to maternal therapy with antithyroid drugs

The occurrence of neonatal goiter or hypothyroidism is described in two sets of dizygotic twins born tothyrotoxic mothers treated with antithyroid drugs during gestation. In the first set of twins, one presented with a transient though significant goiter in the presence of slightly diminished level of serum free thyroxine. In the second set, one twin also had a transient though significant depression in serum free thyroxine. In both instances, only the affected infant had transient elevation of serum thyrotropin as measured by immunoassay and/or bioassay. Thus, for the first time, the hypothesis that antithyroid drugs cause thyroid hyperplasia in the human fetus by the stimulation of fetal pituitary thyrotropin has been confirmed. Possible factors responsible for the selective effect of antithyroid drugs in one member of each set of twins are discussed.
ZINC AND COPPER TOLERANCE OF AGROSTIS STOLONIFERA L. IN TISSUE CULTURE

Callus tissue was induced from shoot meristematic tissue and root tips of a clone of the grass Agrostis stolonifera tolerant to both zinc and copper, and from a control clone tolerant to neither metal. Growth of the callus tissue on media containing zinc and copper showed that tolerance to both metals was maintained in tissue culture. The pattern of metal uptake in tissue culture resembled uptake by whole plants in that tolerant tissue took up more metal than nontolerant tissue. Plants regenerated from callus had the same copper and zinc tolerance as the original parental clones regardless of time of growth in tissue culture and shoot or root origin of the tissue. The results support previous evidence that metal tolerance is genetically determined and acts at the cellular level.
Intralineage Directional Notch Signaling Regulates Self-Renewal and Differentiation of Asymmetrically Dividing Radial Glia

Asymmetric division of progenitor/stem cells generates both self-renewing and differentiating progeny and is fundamental to development and regeneration. How this process is regulated in the vertebrate brain remains incompletely understood. Here, we use time-lapse imaging to track radial glia progenitor behavior in the developing zebrafish brain. We find that asymmetric division invariably generates a basal self-renewing daughter and an apical differentiating sibling. Gene expression and genetic mosaic analysis further show that the apical daughter is the source of Notch ligand that is essential to maintain higher Notch activity in the basal daughter. Notably, establishment of this intralineage and directional Notch signaling requires the intrinsic polarity regulator Partitioning defective protein-3 (Par-3), which segregates the fate determinant Mind bomb unequally to the apical daughter, thereby restricting the self-renewal potential to the basal daughter. These findings reveal with single-cell resolution how self-renewal and differentiation become precisely segregated within asymmetrically dividing neural progenitor/stem lineages.