cssi/SciSciGPT-SciSciNet huggingface dataset:
AUTOIMMUNE DISEASE IN NZB/BL MICE. I. PATHOLOGY AND PATHOGENESIS OF A MODEL SYSTEM OF SPONTANEOUS GLOMERULONEPHRITIS.

This study, based upon 528 laboratory examinations and 16 complete autopsies of NZB/Bl mice, deals with autoimmune manifestations (as shown by hypergammaglobulinemia, Coombs positive hemolytic anemia, and the occasional presence of lupus- and rheumatoid-like factors) and mainly with the pathology and the pathogenesis of glomerulonephritis in these mice, a model system of membranous glomerulonephritis with spontaneous and insidious onset, progression through chronic stages, and almost certainly induced by immunological, and autoimmune, mechanisms. The earliest and lasting histological change was hyaline thickening of the capillary walls and adjacent intercapillary regions of the glomerular tufts, corresponding in location to polysaccharide-rich capillary basement membrane and mesangial materials. Distributed focally and diffusely in the glomerular tuft and eventually sparing no glomerulus, hyaline, granular, and fibrillar ("spongy fiber") materials produced narrowing of capillary lumens by concentric or eccentric encroachment upon them. In the later stages hyaline lobulation and sclerosis of the glomerular tufts occurred. Thus the lesions corresponded to those seen in human focal and diffuse membranous, chronic lobular, and lastly (intracapillary) sclerosing glomerulonephritis. In all instances of glomerulonephritis the glomerular tufts contained selective localizations of mouse immunoglobulins corresponding in distribution to that of the hyaline and (PAS-positive) polysaccharide-rich materials in the focal and diffuse membranous and lobular lesions and in amounts increasing with the severity of glomerular disease. The mouse immunoglobulins were extracted from frozen sections of glomerulonephritic kidneys and were then capable of recombination with glomerular tufts in sections of autologous or isologous glomerulonephritic kidneys from which in vivo localized immunoglobulins had been extracted. The pattern of recombination with glomerular tufts was similar to that of in invo localized immunoglobulins. The extracted immunoglobulins did not show affinity for mouse red cells (in the indirect Coombs test) nor for autologous or isologous cell nuclei (in the immunofluorescence test). The serum of mice with severe glomerulonephritis contained immunoglobulins with in vitro affinity for extracted autologous or isologous glomerular tufts. Thus circulating as well as localized antibodies were demonstrated. The immunogenic materials (autoantigens) may have been formed in the glomerular tufts or accumulated in them from some other source, such as the circulating plasma; however they corresponded in location to polysaccharide-rich capillary basement membrane and mesangial materials. The spleen was identified at the cellular level as the main site of formation of autoantibodies to red cells, as well as the main site of red cell destruction. Some evidence was brought forth suggesting that these autoantibodies were "heavy" or γM-globulins. More studies are in progress.
Altered expression of growth factors and cytokines in keratoconus, bullous keratopathy and diabetic human corneas.

The purpose of this study was to identify the growth factors and cytokines present in normal and diseased corneas. Total RNA was isolated from normal and diseased corneas. cDNA was synthesized from individual corneas and semiquantitative reverse transcription-polymerase chain reaction (RT-PCR) was performed with primers to IL-1alpha, 1IL-8, PDGF-B, BMP-2, BMP-4, IGF-I, TGF-beta2, FGF-2, and VEGF. After normalization to beta2-microglobulin, several factors were identified that were significantly different from normal. Antibodies to IGF-I, BMP-2, VEGF and TGF-beta2 were used for immunohistochemistry. A total of 93 corneas were used for this study including 31 normal, 20 keratoconus, 19 bullous keratopathy (pseudophakic and aphakic, PBK/ABK), and 23 diabetic corneas. The VEGF RNA levels were significantly decreased in the keratoconus and PBK/ABK corneas but increased in the diabetic corneas. BMP-2 gene expression was lower than normal in the PBK/ABK and diabetic corneas. IGF-I and BMP-4 RNA levels were increased in PBK/ABK. In the immunohistochemical studies, the protein patterns paralleled those found at the mRNA level. The only exception was IGF-I in diabetic corneas that showed increased staining in the epithelium and its basement membrane without a significant increase in mRNA levels. TGF-beta2 mRNA and protein levels were similar to normal in all diseased corneas. Thus, no alterations in the tested growth factors/cytokines were unique to keratoconus corneas. In contrast, PBK/ABK corneas had specific significant elevations of BMP-4 and IGF-I. Diabetic corneas were unique in their increased VEGF mRNA levels. These data suggest that while some growth factor/cytokine alterations are non-specific and can be found in multiple corneal diseases, there are others that are unique to that disease.
DNA replication specificity and functional E2 interaction of the E1 proteins of human papillomavirus types 1a and 18 are determined by their carboxyl-terminal halves.

Abstract Replication of most papillomaviruses (PVs) requires the viral-encoded E1 and E2 proteins that bind to the origin of replication (ori) containing the E1- and E2-binding sites and help recruit host replication factors during the initiation of DNA replication. We studied the ability of heterologous E1 and E2 proteins to interact in vivo and support replication, using the human papillomavirus (HPV) types 1a and 18 as model systems. The E1 protein of HPV-1a in combination with HPV-18 E2 supported high-level replication of various ori plasmids. In contrast, the HPV-18 E1 protein interacted weakly with HPV-1a E2 during the replication of ori plasmids. We have previously shown that the E1 protein of HPV-1a alone is sufficient for replication of HPV-1a ori plasmids, whereas HPV-18 replication requires both the E1 and E2 proteins. However, in the latter case, E2-binding sites alone in the absence of the E1-binding site can function as the minimal ori. Based on the above observations, we generated hybrids between HPV-1a and HPV-18 E1 proteins in an effort to identify their “replication specificity” domains using a transient replication assay. These hybrids were also used to localize the domains in the E1 proteins that are involved in their functional interaction with the E2 protein during replication. Our results suggest that the “replication specificity” and functional E2 interaction domains of the HPV-1a and HPV-18 E1 proteins are located in their carboxyl-terminal halves.
Gun Violence Is a Health Crisis: Physicians’ Responsibilities

If we were told of a preventable condition that kills 30,000 people in our country each year, and that it could be curbed by changing public opinion, we’d think the task was in reach. Marketing has turned the tide against smoking, for example. Cigarettes’ status has fallen from fashionable to toxic. This was a slow process—changes in advertising, education, films, and, eventually, laws, made it clear that smoking kills. Guns kill--just like smoking, just like substance abuse, just like driving without a seatbelt. However, guns are also an icon of safety and personal freedom for many. Given the epidemic of gun-related injury and death, how do physicians reconcile our duty to reduce morbidity and mortality with Americans’ value of individual freedom? As doctors, our patients and the public depend on us to neither wait for a marketing campaign for a health measure that is warranted nor to be inhibited by marketing that promotes a dangerous product. We are expected to state clearly what is in the best health interest of our patients and the public. We understand and accept that military personnel and police require guns to protect the public. Whether the public should have guns, especially ones that are designed to kill as many people as possible as quickly as possible, is debatable. What is not debatable are the consequences. Thousands of Americans die every month from guns used outside of military or police use. By 2015, gun-related deaths are expected to exceed deaths from motor vehicle accidents.5 As physicians, teachers, researchers, and stewards of the public health, what are our responsibilities? In each of these roles, we have opportunities to reduce preventable death and injury due to firearms.... Language: en
Thermal strain in lead thin films IV: Effects of multiple cycling to 4.2 K

Abstract Using scanning electron microscopy and X-ray diffraction, strain, surface morphology and grain rotation were investigated in lead thin films which were deposited onto oxidized silicon wafers at room temperature and then thermally cycled up to 400 times between room temperature and liquid helium temperature. The strains measured at 4.2 K for films cycled 400 times were observed to have the same dependence on film thickness as that observed the first time the films were cooled to 4.2 K. In the films greater than 0.2 microm thick many discolation slip lines and hillocks were observed inside grains and on grain boundaries respectively after multiple cycling. The densities of the dislocation lines and the hillocks increased with the number of cycles. It was observed that repeated cycling caused rotation of (111)-oriented grains such that the (111) planes of different grains became more nearly coplanar and parallel to the substrate surface. The amount of grain rotation increased with the logarithm of the accumulated amount of plastic strain induced by the thermal cycling.
Laparoscopic Versus Open Radical Nephrectomy for Xanthogranulomatous Pyelonephritis: Contemporary Outcomes Analysis

Background and Purpose: Early experience with laparoscopic nephrectomy for xanthogranulomatous pyelonephritis (XGP) was associated with high conversion and complication rates. We describe our institution's experience with this procedure compared with a contemporary cohort of patients with XGP treated by open nephrectomy. Patients and Methods: Retrospective review of surgical pathology reports from radical nephrectomies at our institution between 1995 and 2005 yielded a diagnosis of XGP in 12 patients, 6 of whom had undergone laparoscopic surgery. Each patient's medical records were reviewed, with intraoperative and postoperative parameters, including complications, being recorded. Results: Transperitoneal laparoscopic nephrectomy was successful in five patients (83%). Hand-assist ports were utilized in two patients because of failure to progress. The operative times were 301 ± 106 minutes and 167 ± 40 minutes in the laparoscopic and open-surgery groups, respectively (P = 0.03). There was no statistical di...
A new approach for estimating the recrystallization rate and equilibrium melting temperature

A method is described for measuring the heat and rate of recrystallization following partial melting. The method uses a specific sequence of temperatures with a differential scanning calorimeter, and the melting and recrystallization processes were confirmed by optical observations. The method was applied to poly(butylene terephthalate). The rate of recrystallization was found to be roughly two orders of magnitude faster than isothermal crystallization from the melt. The melting temperatures obtained from recrystallization were used in the Hoffman–Weeks equation to deduce 236°C as the equilibrium melting temperature for poly(butylene terephthalate). © 1998 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 36: 133–141, 1998
Uniqueness of the impulse function of a discrete-time Markov process

The object of the letter is to find a unique function of n which represents the inverse z transform of unity (1) in the analysis of a finite-state Markov process. The function of n is found to be the sum of two ordinary step functions. The necessary and sufficient conditions for the existence of a one in the z domain in the analysis of a Markov process are determined. Using the necessary and sufficient conditions, the various configurations of the Markov process in which this situation exists are investigated.
Synthesis and Reactivity of Tungsten(II) Methylene Complexes

Treatment of the methyl complex Tp‘(CO)(PhC2Me)W−Me (1) or Tp(CO)(PhC2Ph)W−Me (2) with trityl cation yields the corresponding methylene complex [Tp‘(CO)(PhC2Me)WCH2][PF6] (3) (Tp‘ = hydridotris-(3,5-dimethylpyrazolyl)borate) or [Tp(CO)(PhC2Ph)WCH2][PF6] (4) (Tp = hydridotris(pyrazolyl)borate). The carbene complex (3) is unusually persistent for a methylene complex. Complexes 3 and 4 display electrophilic behavior, as evidenced both by addition of nucleophiles and by methylene transfer to electron rich olefins. When bound to either carbene 3 or 4, arylimines are activated toward nucleophilic attack by ethyl diazoacetate (EDA). The net result of the addition of excess arylimine followed by excess EDA to a solution of either 3 or 4 is catalytic aziridine formation. X-ray diffraction studies have revealed the structures of [Tp‘(CO)(PhC2Me)W−CH2PMe3][PF6] (7) and [Tp‘(CO)(PhC2Me)W−CH2N(Me)C(H)(Ph)][PF6] (15). The relative stabilities of 3 and 4 are discussed as well as the mechanism of aziridine catalysis.
Freudian Daydreams in Jeffrey Eugenides's MIDDLESEX

In The Interpretation of Dreams, Sigmund Freud credits a paper presented by Paul Federn at a meeting of the Vienna Psychoanalytical Society in 1914 for the insight that “flying dreams are dreams of...
Programmable Separation for Biologically Active Molecules

Separation of biologically active molecules (BAMs) is a problem for the pharmaceutical and biotechnology industries. Current technologies addressing this problem require too many techniques, toxic additives, and time to filter the desired materials. As a result, a new technology is needed. The objective of this work is to contribute to the development of a device that can separate 0.5 nm to 500 nm sized BAMs. A diaphragm valve is proposed that can control a gap created by two parallel flat surfaces. Position control is achieved by means of a piezoelectric actuator and a capacitive sensor. Modularity was also part of design considerations to address issues of eventual biocompatibility breakdown. Preliminary experiments indicate that gap separation can be controlled to increments of 0.2 nm.Copyright © 2006 by ASME
Extension and contraction within volcanically buried impact craters and basins on Mercury

Orbital images of Mercury obtained by the MESSENGER spacecraft have revealed families of troughs, interpreted to be graben, on volcanic plains material that largely or completely buried preexisting craters and basins. The graben are partially to fully encircled by rings of contractional wrinkle ridges localized over the rims of the buried impact features to form systems of associated contractional and extensional landforms. Most of the buried craters and basins with graben identified to date are located in the extensive volcanic plains that cover much of Mercury’s northern high latitudes. The distinctive relationship between wrinkle ridges and graben in buried craters and basins on Mercury is interpreted to be the result of a combination of extensional stresses from cooling and thermal contraction of thick lava flow units and compressional stresses from cooling and contraction of the planet’s interior.
Optoelectronic feature extractor for classification of fingerprints

We present the design and test results of an optoelectronic feature detector array for use in a fingerprint ridge extraction system. The system comprises a microlens array for taking multiple Fourier transforms and an array of detectors. Each detector is composed of a set of wedge photodetectors with associated winner-take-all circuitry and encoders for reporting the maximally stimulated wedge element.
Serum sex hormone levels and myocardial infarction in the Honolulu Heart Program. Pitfalls in prospective studies on sex hormones.

Abstract It has been hypothesized that hyperestrogenemia may underlie myocardial infarction. As a test of this hypothesis, the serum estradiol and testosterone levels were estimated in samples collected prospectively from 96 male patients aged 52–74 years [mean age 60.8 ± 6.3 (SD)] who had had a myocardial infarction and from 96 matched control subjects in the Honolulu Heart Program. Established risk factors for myocardial infarction were measured prospectively. No significant difference between patients and control subjects in mean estradiol or testosterone level was observed. The only established risk factor that was significantly different was blood pressure, which was higher in the patients. Thus, the data did not confirm the hypothesis. However, two major pitfalls for prospective studies of estradiol in myocardial infarction, which might have affected the validity of the results, were observed, namely, deterioration of estradiol values with prolonged storage (8.5–12 years in this study) and intervention. The value of this study, therefore, may he in pointing out difficulties in carrying out prospective studies on sex hormones.
An analysis of “exactly distributed” test statistics for multivariate event tests

In this paper we derive a rule that identifies when exact tests may be used in the context of the multivariate regression model. Our derivation extends distribution theory reported in Rao (1973) and leads to the specification of exact tests for several event study hypothesis forms of interest to accounting and finance researchers. For tests where the event parameter is constrained to be equal across firms, we show that an infinite set of exact tests is available, of which the well known portfoliot-test is a special case. We conduct simulations using data from the CRSP Daily Returns file, and find that several test statistics, including exactly distributed statistics derived using the multivariate regression model, significantly over-reject the hypotheses examined.
Measuring the sea ice floe size distribution

The sea ice covering the Arctic Ocean is broken into distinct pieces,called floes. In the summer, these floes, which have diameters ranging up to 100 km, are separated from each other by a region of open water. In the winter, floes still exist, but they are less easily identified. An understanding of the geometry of the ice pack is of interest for a number of practical applications associated with transportation in ice-covered seas and with the design of offshore structures intended to survive in the presence of ice. The present investigation has the objective to clarify ideas about floe sizes and to propose techniques for measuring them. Measurements are presented with the primary aim to illustrate points of technique or approach. A preliminary discussion of the floe size distribution of sea ice is devoted to questions of definition and of measurement.
Aristotle's Definition of Rhetoric in the "Rhetoric": The Metaphors and their Message

In spite of the continuing influence of Aristotle's Rhetoric on the discipline of rhetoric, no widespread agreement exists about whether the text is a systematic treatise about the tekhne (art) of rhetoric or a disconnected set of lecture notes. A significant piece of the puzzle belongs to Aristotle's metaphorical definitions of rhetoric in Book I of that text. Although scholarly efforts to interpret these definitions have informed our understanding of the text, they have done so without fully addressing how these definitions function within the text. This article affers a new approach to investigating these statements, one that considers them from Aristotle's own perspective on such linguistic matters: the author uses Aristotle's theory of metaphor as a measure of his practice in these definitions. The outcome indicates that Aristotle's practice in this situation does not match his theory, a circumstance that has certain consequences for our reading of the Rhetoric.
Nonadditivity of mutational effects at the folate binding site of Escherichia coli dihydrofolate reductase

The function of the hydrophobic residues Leu28, Phe3 1, Ile50, and Leu54 at the folate binding site in Escherichia coli dihydrofolate reductase (5,6,7,8-tetrahydrofolate:NADP+ oxidoreductase, EC 1.5.1.3) has been studied by a combination of site-specific mutagenesis and reaction kinetics. Studies suggest that the overall protein structure and kinetic sequence for the reaction did not change for the mutant proteins compared to the wild-type enzyme. Two sets of mutated reductases have been constructed. The first set, in which the side chains of the targeted amino acids are spatially well separated (- 8 A), includes two single mutants (L28Y and L54F) and a double mutant (L28Y-L54F). This set features residues that increased the side chain surface area and the potential for substrate interactions. Unexpectedly, nonadditivity in the free energy changes for the thermodynamics of ligand binding and in the rates of hydride transfer and product release is observed. The progressive increase in dihydrofolate binding is reversed for the sterically more crowded double mutant, with AAG ca. 3 kcal mol-' less favorable than anticipated. On the other hand, the decrease in the rate constant for hydride transfer noted with the single mutants relative to the wild-type enzyme is reversed for the double mutant, so that AAG* is ca. 2 kcal mol-' more favorable. The second set of mutant proteins includes two double mutants (L28A-F31A and 150A-L54G) in which the selected amino acids are separated by three to four intervening amino acids and a quadruple mutant (L28A- F31A-150A-LS4G) in which the two sets L28A-F31A and ISOA-L54G are spatially distinct. This set deleted the side chain surface area to lower the opportunity for substrate interactions. Nonadditivity in the free energy changes associated with key kinetic and thermodynamic parameters is again observed. The decrease in dihydrofolate binding found with the two double mutants is not observed with the quadruple mutant, which binds the substrate with AAG ca. 6.5 kcal mol-' more favorable than expected. Similarly, the quadruple mutant has a larger rate constant for hydride transfer (-AAG* 1.7 kcal mol-') than predicted. One interpretation for the nonadditivity is that these residues interact through binding of the folate substrate, which serves to link molecularly remote side chain moieties within the active site. The resiliency of the active site to tolerate such damage suggests that there must be sufficient flexibility and redundancy built into the site and its framework to retain a high population of active enzyme-substrate complexes.
In situ formation of ruthenium catalysts for the homogeneous hydrogenation of carbon dioxide.

A total of 44 different phosphines were tested, in combination with [RuCl2(C6H6)]2 and three other Ru(II) precursors, for their ability to form active catalysts for the hydrogenation of CO2 to formic acid. Half (22) of the ligands formed catalysts of significant activity, and only 6 resulted in very high rates of production of formic acid. These were PMe3, PPhMe2, dppm, dppe, and cis- and trans-Ph2PCHCHPPh2. The in situ catalysts prepared from [RuCl2(C6H6)]2 and any of these 6 phosphine ligands were found to be at least as efficient as the isolated catalyst RuCl(O2CMe)(PMe3)4. There was no correlation between the basicity of monophosphines (PR3) and the activity of the catalysts formed from them. However, weakly basic diphosphines formed highly active catalysts only if their bite angles were small, while more strongly basic diphosphines had the opposite trend. In situ 31P NMR spectroscopy showed that trans-Ru(H)2(dppm)2, trans-RuCl2(dppm)2, trans-RuHCl(dppm)2, cis-Ru(H)(O2CH)(dppm)2, and cis-Ru(O2CH)2(dpp...
How Kinetics within the Unfolded State Affects Protein Folding: An Analysis Based on Markov State Models and an Ultra-Long MD Trajectory

Understanding how kinetics in the unfolded state affects protein folding is a fundamentally important yet less well-understood issue. Here we employ three different models to analyze the unfolded landscape and folding kinetics of the miniprotein Trp-cage. The first is a 208 μs explicit solvent molecular dynamics (MD) simulation from D. E. Shaw Research containing tens of folding events. The second is a Markov state model (MSM-MD) constructed from the same ultralong MD simulation; MSM-MD can be used to generate thousands of folding events. The third is a Markov state model built from temperature replica exchange MD simulations in implicit solvent (MSM-REMD). All the models exhibit multiple folding pathways, and there is a good correspondence between the folding pathways from direct MD and those computed from the MSMs. The unfolded populations interconvert rapidly between extended and collapsed conformations on time scales ≤40 ns, compared with the folding time of ∼5 μs. The folding rates are independent of...
Experimental acoustic-surface-wave-to-bulk-wave scattering by grooves

The letter describes results obtained on the conversion of acoustic surface waves into bulk waves through scattering by rectangular grooves on aluminium at 1.15 MHz, and gives a comparison with theoretical predictions.
Systemic therapy for advanced or recurrent endometrial carcinoma

The prognosis for metastatic or recurrent endometrial cancer remains poor. Patients with local recurrences can sometimes be salvaged with radiation, and these salvage rates might improve with the addition of concomitant chemotherapy. Hormone therapy benefits a small group of patients, and routine immunohistochemical determination of tumor receptor status may help select patients most likely to benefit from such therapy. Anthracyclines, platinum compounds, and paclitaxel consistently produce response rates of over 20%. Combination chemotherapy produces higher response rates, but it is toxic and appears to have minimal effect on survival. New drugs and combinations continue to be tested. A subset of endometrial cancers overexpress the HER2/neu oncogene, and a trial of anti-HER2/neu monoclonal antibody for this group is planned through the Gynecologic Oncology Group.
Closed 2-cell embeddings of graphs with no V 8 -minors

Abstract A closed 2-cell embedding of a graph embedded in some surface is an embedding such that each face is bounded by a cycle in the graph. The strong embedding conjecture says that every 2-connected graph has a closed 2-cell embedding in some surface. In this paper, we prove that any 2-connected graph without V 8 (the Mobius 4-ladder) as a minor has a closed 2-cell embedding in some surface. As a corollary, such a graph has a cycle double cover. The proof uses a classification of internally-4-connected graphs with no V 8 -minor (due to Kelmans and independently Robertson), and the proof depends heavily on such a characterization.
The Tumor Suppressor PTEN Is Necessary for Human Sprouty 2-mediated Inhibition of Cell Proliferation

Sprouty family proteins are novel regulators of growth factor actions. Human Sprouty 2 (hSPRY2) inhibits the proliferation of a number of different cell types. However, the mechanisms involved in the anti-proliferative actions of hSPRY2 remain to be elucidated. Here we have demonstrated that hSPRY2 increases the amount of the tumor suppressor phosphatase and tensin homolog deleted on chromosome 10 (PTEN) and decreases its phosphorylation. The resultant increase in PTEN activity is reflected in decreased activation of Akt by epidermal growth factor and serum. Consistent with increased PTEN activity, in hSPRY2-expressing cells, the progression of cells from the G1 to S phase is decreased. By using PTEN null primary mouse embryonic fibroblasts and their isogenic controls as well as small interfering RNA against PTEN, we demonstrated that PTEN is necessary for hSPRY2 to inhibit Akt activation by epidermal growth factor as well as cell proliferation. Overall, we concluded that hSPRY2 mediates its anti-proliferative actions by altering PTEN content and activity.
Oliver G. Selfridge (1926-2008)

Oliver G. Selfridge, a leader in early artificial intelligence research, whose work extended from 1956 to 2008, recently passed away. His research in machine learning, neural networks and agent-based computing still influence AI today. He helped organize the 1956 Dartmouth summer school, which is generally seen as the origin of American AI and developed Pandemonium, an early AI program that dealt with learning and reasoning, during his more than 50-year career.
Spontaneous adsorption of teichoic acid to erythrocytes.

Abstract A teichoic acid antigen consisting of polyglycerophosphate, essentially free of alanine or other side groups, was shown to adsorb spontaneously to the erythrocytes of several species, thus potentiating their activity in passive hemagglutination (PHA) by specific antisera. The adsorption of this antigen was influenced by time, temperature, pH, ion concentration and antigen concentration. The bond appeared to be weak and a reverse reaction occurred, which may account for differences in PHA results reported by others. A recommended procedure for coating red cells with teichoic acid is presented.
Structure and Function of Membrane-Remodeling ESCRT-III Assemblies

The ESCRT pathway mediates a series of important cellular membrane remodeling and fission events, including cytokinetic abscission. During these processes, ESCRT-III family proteins, including CHMP1B and IST1, form filaments that appear to constrict membranes and facilitate fission. Here, we report the first structure of “open” and assembled ESCRT-III proteins. Near-atomic resolution electron cryomicroscopy reveals that filaments comprise a copolymeric assembly of an open conformation inner strand and, unexpectedly, a closed conformation outer strand.
Disilane Internal Rotation

Energetics of hindered rotation in disilane are analyzed and compared to ethane. In disilane weakened (rotationally governed) hyperconjugative interactions, paramount in controlling the ethane barrier, leave the nonrotational part of the torsional coordinate as the primary contribution to disilane barrier energetics. In this regard, the 0.012 A Si−Si bond lengthening that accompanies rotation is found to account for most of the 1.0 kcal/mol barrier. Although both the Si−Si bond expansion in disilane and the 0.014 A C−C bond expansion in ethane are nearly the same, the mechanisms for these expansions are found to be different. Unlike in ethane, where the expansion is largely due to the hyperconjugation decrease in the eclipsed conformer, in disilane it is almost entirely due to electrostatic repulsion between Si−H bonds in the two silyl groups.
Time Variation of the Fundamental "Constants" and Kaluza-Klein Theories

Time dependence of the fundamental ''constants'' is examined within the framework of Kaluza-Klein theories. Relationships among low-energy couplings and masses are derived. It is suggested that detection of a time variation in any of these parameters may provide evidence for extra space dimensions. Experimental bounds are reviewed and new measurements advocated.
Public Diplomacy, Smith-Mundt and the American Public

The U.S. Information and Educational Exchange Act of 1948, also known as the Smith-Mundt Act, is a mostly unknown and widely misunderstood piece of legislation. Revised multiple times, the law bans domestic dissemination of Voice of America and other U.S. international broadcast content in the United States. Presenting government-supported international broadcasting as an example of public diplomacy, this article discusses the long-term misrepresentation of Smith-Mundt's original intent and highlights the consequences of the continuing ban. The article considers prospects for ending the ban and emphasizes potential opportunities presented by its elimination, concluding that ending the ban might eliminate incongruity between American foreign policy goals of democracy promotion and the reality of banned domestic content. Repeal of the ban may also result in unexpected remedies for challenges facing the American media industry and the American public's desire for international news. The United States governm...
Sphingosine-1-phosphate signaling and its role in disease

The bioactive sphingolipid metabolite sphingosine-1-phosphate (S1P) is now recognized as a critical regulator of many physiological and pathophysiological processes, including cancer, atherosclerosis, diabetes and osteoporosis. S1P is produced in cells by two sphingosine kinase isoenzymes, SphK1 and SphK2. Many cells secrete S1P, which can then act in an autocrine or paracrine manner. Most of the known actions of S1P are mediated by a family of five specific G protein-coupled receptors. More recently, it was shown that S1P also has important intracellular targets involved in inflammation, cancer and Alzheimer's disease. This suggests that S1P actions are much more complex than previously thought, with important ramifications for development of therapeutics. This review highlights recent advances in our understanding of the mechanisms of action of S1P and its roles in disease.
Physical limitations of the rapid freezing method.

Throughout the recorded history of biological freezing, it has generally been recognized that one may differentiate between rapid and slow freezing, although it has not always been realized how compelling is the distinction which can be drawn between the two on the basis of the markedly different distribution of ice crystals and the differing mechanism of cell injury which may result. In order, therefore, to discuss the physical limitations of rapid freezing, the term must be defined and differentiated from slow freezing. This paper thus becomes primarily a discussion of slow and rapid freezing from which the limitations of the rapid freezing method should become self evident. Possibly the single most important concept in biological freezing as well as the most difficult for the biologist to assimilate is the following: despite the collective and individual complexity of living cells, freezing in a biological matrix represents nothing more than the removal of all available water and its isolation into inert foreign bodies, the ice crystals. Freezing is a wholly physical phenomenon obeying known and simple laws and, tempting though it may be to imbue biological freezing with the same mysterious complexity that surrounds the cells themselves, it is quite unnecessary. The transfer of water out of solution into ice crystals is a very straightforward phenomenon and is, in effect, simply dehydration with the removed water sequestered locally in the tissue rather than entirely removed. From this dual event—dehydration with foreign body formation—stem all the physiological and biochemical events subsequent to freezing (Meryman 1956).
Revisiting the Historical Use of the Assessment Centre in Management Selection and Development

The assessment centre method has received considerable historical attention as an effective tool for management selection and development. The method, originally developed by German psychologists, was used extensively during World War II by the Office of Strategic Services. Refinement of the method occurred at the American Telephone and Telegraph Company during the mid‐1950s in the Management Progress Study under the leadership of Dr Douglas W. Bray. The method found increased acceptance due, in part, to court decisions finding it in compliance with EEOC guidelines. The process used proposes to evaluate the relative strength within an individual of up to ten personality traits using exercises simulating job conditions and events. Studies performed years after assessment show impressive figures regarding the method′s ability to predict management success. Continuing research has shown a use for this method at all levels within an organisation.
The behavior of rare earth elements in naturally and anthropogenically acidified waters

Abstract In this paper, the behavior of rare earth elements (REE) in a watershed impacted by acid-mine drainage (Fisher Creek, Montana) is compared to that in a volcanically acidified watershed (Rio Agrio and Lake Caviahue, Argentina). The REE behave conservatively in acidic waters with pH values less than approximately 5.5. However, above pH 5.5, REE concentrations are controlled by adsorption onto or co-precipitation with a variety of Fe or Al oxyhydroxides. The heavy REE partition to a greater extent into the solid phase than the light REE as pH rises above 6. Concentrations of REE exhibit diel (24-h) cycling in waters that were initially acidic, but have become neutralized downstream. In Fisher Creek, at the most downstream sampling station investigated (pH 6.8), concentrations of dissolved REE were 190–840% higher in the early morning versus the late afternoon. This cycling can be related to temperature-dependent, cyclic adsorption–desorption of REE onto hydrous ferric or aluminum oxide or both. Similar but gentler diel cycling of the REE was found at Rio Agrio. The existence of such cycling has important ramifications for the study of REE in natural waters.
The condensation and vaporization behavior of H2O:CO ices and implications for interstellar grains and cometary activity

IR spectroscopy has been used to ascertain several parameters associated with CO, H2O, and H2O:CO ices' physical behavior. Since CO is noted to be capable of condensing into H2O-rich ices at temperatures that are twice as high as those required for condensation in pure CO, CO is able to condense onto H2O-rich ice grains at temperatures of up to 50 K. CO's presence in H2O ice modestly enhances the effective volatility of the H2O. Attention is given to the implications of these results for cometary models generally and the question of cometary formation specifically.
Brief communication: Enamel thickness and durophagy in mangabeys revisited

The documentation of enamel thickness variation across primates is important because enamel thickness has both taxonomic and functional relevance. The Old World monkeys commonly referred to as mangabeys have figured prominently in investigations of feeding ecology and enamel thickness. In this article, we report enamel thickness values for four mangabey taxa (Cercocebus atys, Cercocebus torquatus, Lophocebus aterrimus, and Lophocebus albigena), offer revised interpretation of the significance of thick enamel in papionin evolution, and place our new data in a broader comparative framework. Our data indicate that all mangabeys have thick enamel and that the values obtained for Cercocebus and Lophocebus equal or exceed those published for most extant non-human primates. In addition, new field data combined with a current reading of the dietary literature indicate that hard foods make up a portion of the diet of every mangabey species sampled to date. Clarification on the relationship between diet and enamel thickness among mangabeys is important not only because of recognition that mangabeys are not a natural group but also because of recent arguments that explain thick enamel as an evolved response to the seasonal consumption of hard foods.
Above-threshold multiphoton detachment of H- by two-color laser fields: Angular distributions and partial rates.

We present a general nonperturbative formalism and an efficient and accurate numerical technique for the study of the angular distributions and partial widths for multiphoton above-threshold detachment in two-color fields. The procedure is based on an extension of our recent paper [D. A. Telnov and S.-I Chu, Phys. Rev. A 50, 4099 (1994)] for one-color detachment, and the many-mode Floquet theory [T. S. Ho, S.-I Chu, and J. V. Tietz, Chem. Phys. Lett. 96, 464 (1983)]. The generalization of this procedure is performed for both cases of commensurable and incommensurable frequencies of the two-color fields. The procedure consists of the following elements: (i) Determination of the resonance wave function and complex quasienergy by means of the non-Hermitian Floquet Hamiltonian formalism. The Floquet Hamiltonian is discretized by the complex-scaling generalized pseudospectral technique recently developed [J. Wang, S.-I Chu, and C. Laughlin, Phys. Rev. A 50, 3208 (1994)]. (ii) Calculation of the angular distribution and partial widths based on an exact differential formula and a procedure for the rotation of the resonance wave function back to the real axis. The method is applied to a nonperturbative study of multiphoton above-threshold detachment of ${\mathrm{H}}^{\mathrm{\ensuremath{-}}}$ by 10.6-\ensuremath{\mu}m radiation and its third harmonic (the commensurable case). The results show strong dependence on the relative phase \ensuremath{\delta} between the fundamental frequency field and its harmonic. For the intensities used in calculations (${10}^{10}$ W/${\mathrm{cm}}^{2}$ for the fundamental frequency, ${10}^{8}$ and ${10}^{9}$ W/${\mathrm{cm}}^{2}$ for the harmonic), the total rate has its maximum at \ensuremath{\delta}=0 and minimum at \ensuremath{\delta}=\ensuremath{\pi}. However, this tendency, though valid for the first several above-threshold peaks in the energy spectrum, is reversed for the higher-energy peaks. The energy spectrum for \ensuremath{\delta}=\ensuremath{\pi} is broader, and the peak heights decrease more slowly compared to the case of \ensuremath{\delta}=0. The strong phase dependence is also manifested in the angular distributions of the ejected electrons.
The dielectric constant of H2, D2, and HD in the condensed phases

Measurements have been made of the dielectric constant in the liquid and solid phases of H2, D2, and HD. Precise measurements were made in the liquid phase at saturated vapor pressure and compared with previous data. A study was made of the change in the dielectric constant upon solidification. Measurements were made in the solid phases of H2 and HD from the solidifition point to about 0.02 K. Both solids exhibited temperature-dependent dielectric constants which were rather similar. The magnitude of the temperature dependence was found to be related to the concentration of molecules in the rotationalJ=1 state. The dielectric constant of HD was found to change quite dramatically between 1 and 2 K, while H2 and D2 show no similar change.
Preparation and properties of sputtered “glassy” carbon films

Abstract Some remarkable “glassy” carbon films with densities from 0.5 to 1.79 have been prepared by sputtering from carbon targets. Conditions for the preparation of various carbon films by rf sputtering and data on the density, mechanical properties, microhardness, microstructure and crystal structure of the films formed are presented. Optimum sputtering conditions for obtaining mechanically stable films up to 40μ thick are described. It is shown that density and microhardness of the carbon can be controlled within wide limits, and both increase with decreasing deposition rate. The higher density carbon films adhere poorly to glass, while the low density carbon films on glass are stable. All sputtered carbon films are non-crystalline and have a grainy microstructure. Potential applications exclude corrosion protection but include novel catalyst supports.
Estimating the contribution of strong daily export events to total pollutant export from the United States in summer

[1] While the export of pollutants from the United States exhibits notable variability from day to day and is often considered to be “episodic,” the contribution of strong daily export events to total export has not been quantified. We use carbon monoxide (CO) as a tracer of anthropogenic pollutants in the Model of OZone And Related Tracers (MOZART) to estimate this contribution. We first identify the major export pathway from the United States to be through the northeast boundary (24–48°N along 67.5°W and 80–67.5°W along 48°N), and then analyze 15 summers of daily CO export fluxes through this boundary. These daily CO export fluxes have a nearly Gaussian distribution with a mean of 1100 Gg CO day−1 and a standard deviation of 490 Gg CO day−1. To focus on the synoptic variability, we define a “synoptic background” export flux equal to the 15 day moving average export flux and classify strong export days according to their fluxes relative to this background. As expected from Gaussian statistics, 16% of summer days are “strong export days,” classified as those days when the CO export flux exceeds the synoptic background by one standard deviation or more. Strong export days contributes 25% to the total export, a value determined by the relative standard deviation of the CO flux distribution. Regressing the anomalies of the CO export flux through the northeast U.S. boundary relative to the synoptic background on the daily anomalies in the surface pressure field (also relative to a 15 day running mean) suggests that strong daily export fluxes are correlated with passages of midlatitude cyclones over the Gulf of Saint Lawrence. The associated cyclonic circulation and Warm Conveyor Belts (WCBs) that lift surface pollutants over the northeastern United States have been shown previously to be associated with long-range transport events. Comparison with observations from the 2004 INTEX-NA field campaign confirms that our model captures the observed enhancements in CO outflow and resolves the processes associated with cyclone passages on strong export days. “Moderate export days,” defined as days when the CO flux through the northeast boundary exceeds the 15 day running mean by less than one standard deviation, represent an additional 34% of summer days and 40% of total export. These days are also associated with migratory midlatitude cyclones. The remaining 35% of total export occurs on “weak export days” (50% of summer days) when high pressure anomalies occur over the Gulf of Saint Lawrence. Our findings for summer also apply to spring, when the U.S. pollutant export is typically strongest, with similar contributions to total export and associated meteorology on strong, moderate and weak export days. Although cyclone passages are the primary driver for strong daily export events, export during days without cyclone passages also makes a considerable contribution to the total export and thereby to the global pollutant budget.
Capillary dispersion in porous media at low wetting phase saturations

Abstract Spreading of wetting liquid over a surface by disjoining pressure gradient driven film flow and by capillary pressure gradient driven channel flow is well known. Bacri (J. Phys. Lett. (Paris) 46, L467–L473, 1985) reported “anomalously” rapid spreading of wetting liquid during imbibition into a prewet porous medium. We predict quantitatively this phenomenon, called “hyperdispersion,” from viscous flow along pore walls in thin films of thickness h governed by disjoining force and capillarity. Pore radius distribution, pore network topology, and disjoining pressure function Π(h) all determine the magnitude of capillary dispersion. At high capillary pressures, we find that capillary pressure Pc, wetting phase relative permeability krw, and capillary dispersion coefficient Dc can obey power laws in saturation S, which is the sum of the thin-film and pendular-structure inventories: S = Sfilm + Sps. If Π ∝ h−m so that Sfilm ∝ P−1/mc, if Sps ∝ P−bc, and if thin films control flow, two sets of power law behavior exist. In the case 1/m b, Pc ∝ S−1/b, krw ∝ S3/mb, and Dc ∝ S(3−m−mb)/mb. The exponents m and b dictate the behavior of Dc as the saturation of the wetting phase approaches zero. More complex function Π(h) can lead to nonmonotonic Dc(S). Bacri measured Dc values two or three orders of magnitude higher than we predict, implying a distribution of wetting liquid different from any we consider.