cssi/SciSciGPT-SciSciNet huggingface dataset:
A study of the crystallization of polyethylene terephthalate using differential scanning calorimetry and X‐ray techniques

Differential scanning calorimetry has been used to study the kinetics of the crystallization processes of polyethylene terephthalate over a wide temperature range, 95–110°C and 230–240°C. The rates of crystallization of the two processes are in agreement with earlier dilatometric measurements. Nonintegral values of the AVRAMI exponent, n = 4.5 and n = 3.4, found for the low temperature and pre-melt processes, respectively, are not in agreement with reported values of n = 2.0 and n = 4.0 for these processes. The value of n = 4.5 for the low temperature crystallization is surprising and not easily accounted for; one possible explanation is that the time dependence of the nucleation process is greater than first order. Because of their fractionality the n values yield little information on the mechanism of crystallization. Some mechanistic information is available since the low temperature crystallization isotherms are superposable along the log-time axis, whereas the pre-melt isotherms are not. Additional X-ray data have indicated the existence of one crystalline form. The X-ray data show no significant crystallite size increase for samples crystallized at 150°C over those crystallized at 105°C. Samples crystallized at 235°C show a larger and more ordered crystalline structure than those crystallized at 105 and 150°C. The relationship between the crystalline melting points and the temperatures of crystallization is as predicted by MANDELKERN. Die Kinetik der Kristallisation von Poly(athylenterephthalat) wurde mit einem Differentialkalorimeter in einem weiten Temperaturbereich (95–110°C und 230–240°C) untersucht. Die Kristallisationsgeschwindigkeiten der beiden Prozesse sind in Ubereinstimmung mit fruheren dilatometrischen Messungen. Die nicht ganzzahligen Werte fur den AVRAMI-Exponenten, n = 4,5 und n = 3,4 fur die Kristallisation bei niederen Temperaturen bzw. vorgeschmolzenen Proben, stimmen nicht mit den veroffentlichten Werten von n = 2,0 und n = 4,0 uberein. Der Wert von n = 4,5 fur die Kristallisation bei niederen Temperaturen ist uberraschend. Eine mogliche Erklarung besteht darin, die Kristallisationskeimbildung als eine Funktion hoherer Ordnung anzunehmen. Da die n-Werte keine ganzen Zahlen sind, geben sie nur geringe Hinweise uber den Mechanismus der Kristallisation. Hinweise uber den Mechanismus geben die Isothermen der Kristallisation bei niederen Temperaturen. Diese sind entlang der log-T-Achse deckungsgleich, was fur die Isothermen der vorgeschmolzenen Proben nicht zutrifft. Zusatzliche rontgenographische Untersuchungen zeigen die Anwesenheit von nur einer Kristallform. Sie zeigen ferner keine wesentliche Zunahme der Kristallitgrose in Proben, die bei 150 bzw. 105°C kristallisiert wurden; bei 235°C kristallisierte Proben zeigen hingegen eine besser ausgebildete und hoher orientierte Struktur als die vorgenannten. Der Zusammenhang zwischen den Schmelzpunkten der kristallisierten Proben und der Kristallisationstemperatur stimmt mit den Ergebnissen von MANDELKERN uberein.
Reinterpretation of some tentacular structures in actinodendronid and thalassianthid sea anemones (Cnidaria: Actiniaria)

The oral disc of an actinodendronid sea anemone is drawn out into a variable number of highly branched tentacular structures that make the anemone resemble a tree. These tentacular structures have been considered either lobes or branched tentacles. The term lobe has been applied to various structures of the oral disc in sea anemones; I distinguish between temporary lobes, permanent marginal lobes, and permanent tentacular lobes. I use the number of mesenterial pairs involved in a tentacular structure as evidence that tentacular structures in Actinodendronidae should be considered tentacles, not lobes. According to this interpretation, actinodendronids have only one tentacle communicating with each intermesenterial space, both endocoels and exocoels. The similarity between tentacular structures in members of Actinodendronidae and Thalassianthidae is only superficial; the tentacular structures in these families are not homologues as they have been previously considered.
Experience with Top Gun Wingman: a proxy-based graphical web browser for the 3Com PalmPilot

After an inauspicious debut, communication-enabled personal digital assistants (or PDA's) and handheld PC's are being "rediscovered" as mobile information access terminals. In response, developers have attempted to bring complex applications such as Web browsers to such devices. However, the limited resources available on thin client platforms make them unsuitable for hosting such applications. In this paper, we advocate moving application complexity from thin clients to an adaptive middleware proxy (AMWP), an infrastructural application server platform designed to support large populations and diverse applications. We describe one such application, Top Gun Wingman, a graphical, split Web browser for the Palm Pilot PDA that is currently in use by more than 11,000 users around the world. Our discussion focuses on the design philosophy, implementation, performance, and lessons learned from our experience with the Wingman client and the middleware proxy that supports it.
THE DISTRIBUTION OF PRIME NUMBERS

This is an expanded account of three lectures on the distribution of prime numbers given at the Montreal NATO school on equidistribution.
Organization Change: Theory and Practice

Preface 1 Rethinking Organization Change The Paradox of Planned Organization Change Making the Case for Organization Change Personal Declarations and Points of View 2 A Brief History of Organization Change Scientific Management The Hawthorne Studies Industrial Psychology Survey Feedback Sensitivity Training Sociotechnical Systems Organization Development The Managerial Grid and OD Coercion and Confrontation Management Consulting 3 Theoretical Foundations of Organizations and Organization Change Open Systems Theory Characteristics of Open Systems Organization Change Is Systemic Toward a Deeper Understanding of Organization Change Capra's Three Criteria for Understanding Life Implications for Organizations and Organization Change 4 The Nature of Organization Change Revolutionary Change Evolutionary Change Revolutionary Change-Case Example Evolutionary Change-Case Example The Tools for Assessment and Ratings Data Summary of the Firm's Partners 5 Levels of Organization Change: Individual, Group, and Larger System Change in Organizations at the Individual Level Individual Responses to Organization Change Change in Organizations at the Group Level Group Responses to Organization Change Change in Organizations at the Larger-System Level 6 Organization Change: Research and Theory Reviews of Organization Change Research More Recent Approaches to Research and Theory Organization Models Organization Change Theory Current Thinking Regarding Organization Change and Theory System Responses to Organization Change 7 Conceptual Models for Understanding Organization Change Content: What to Change Process: How to Change -- A Theoretical Framework Process: How to Change -- Practice Frameworks Mini-theories Related to Organization Change The Content and Process of Strategic Change in Organizations Strategies for Effecting Change in Human Systems 8 Integrated Models for Understanding Organizations and for Leading and Managing Change What Is an Organizational Model? Why Use an Organization Model? Organization Models and Organization Change Weisbord's Six-Box Model The Nadler-Tushman Congruence Model Tichy's TPC Framework A Comparison of the Three Models 9 The Burke-Litwin Causal Model of Performance and Change Background The Model Transformational and Transactional Dimensions Support for the Model's Validity Influence of the External Environment The Transformational Factors The Transactional Factors 10 Application of the Burke-Litwin Model Case 1: Dime Bancorp, Inc. Case 2: British Broadcasting Corporation (BBC) 11 Leading Organization Change Does Leadership Matter? On Defining Leadership Toward Further Definition Phases of Organization Change and the Leader's Role The Pre-launch Phase The Launch Phase Post-launch-Further Implementation Sustaining the Change 12 Organization Change: Epidemics, Integration and Future Needs The Tipping Point Applying the "Tipping Point" Principles to Planned Organization Change Changing the Organization Organization Change: What We Need to Know Priorities Conclusion References Appendix: Annotated Bibliography Index About the Author
Nominally Anhydrous Minerals and Earth's Deep Water Cycle

Deep reservoirs of water incorporated as hydroxyl into solid silicate minerals of the Earth's interior may contain the majority of the planet's hydrogen and have acted as buffers to maintain ocean volume and continental freeboard over geologic time. Two tenths of one weight percent H 2 O in subducted oceanic crustal material and subsequently released to the hydrosphere from mid-ocean ridge basalt is sufficient to recycle the total ocean volume once over 4.5 billion years. It is possible that actual fluxes are several times this amount. The nominally anhydrous minerals of the transition zone (410-660 km depth) may serve as a large internal reservoir. New and recent data on molar volumes and elastic properties indicate that hydration has a larger effect on shear velocities than does temperature within their respective uncertainties. Based on these new data, seismic velocities ill this region are consistent with significant hydration (one-half percent or more H 2 O by weight in a pyrolite-composition mantle). The data indicate that lateral velocity variations in the Transition Zone (TZ) may reflect variations in hydration rather than variations in temperature, at least in regions distant from subduction zones.
Overview and evaluation methodologies of high voltage power devices

This paper presents a brief overview, and comprehensive methodologies for evaluating high voltage (HV) power electronic devices. The features of different devices are presented, and the future development trend of power devices is analyzed. To characterize an HV device, a comprehensive methodology including static and switching tests are introduced. The static characterization develops measurement at HV conditions, and the switching characterization focuses on precise measurement and safety considerations in dynamic switching, as well as the design of an HV, high frequency inductor.
Macromolecules of controlled architecture

The recent renaissance in polymer chemistry has resulted in the development of a wide variety of new living polymerisation procedures and the adoption of many synthetic concepts and strategies from organic chemistry, effectively blurring the distinction between organic chemistry and polymer chemistry. A central theme in all of this recent work is the desire to accurately control polymeric structure and functionality to a degree that has previously been solely the domain of natural systems. This has allowed researchers to synthesise a wide range of advanced macromolecular targets with control over shape, size and functional group placement that could not be achieved using traditional procedures and heralds a new era in synthetic polymer chemistry. The scope of this feature article is to provide an insight into the structural diversity that can be accomplished with these recently developed techniques, what challenges still exist and how these advances can impact other related fields in polymer physics and materials science.
Motorists' Use of Sirens: An Informal Look

The motor vehicle code of New York State permits driven of fire engines, ambulances, pol~ce can and other emergency vehicles, when responding to emergencies, to sound a siren. When hearing a suen nearby, other motorists are mandated to pull over to the right edge of the road and stop. This must be done even when it is not known exactly where the emergency vehicle is (2). To achieve some insight as to whether or not other driven might well be using sirens, which may be part of their vehicle's antitheft device, to expedite their passage through congested traffic, an informal inquiry was conducted during the Fall-Winter of 1984-85 and 198788. On both occasions observations were made at the same road intersection in a large city in New York State: a three-lane north-bound street having a peak traffic volume of approximately 1900 commercial and private vehicles per hour and a two-lane west-bound street handling about 1200 vehicles per hour. Flow of traffic through the intersection was controlled by a signal light. During both periods a total of 43 'A-hr. convenience citings were conducted, on Monday through Friday, between the hours of 0800-0930 and 1700-1830. Note was made of the number of times a siren was sounded in the immediate vicinity of the intersection. While the problem of double counting was recognized, it was felt that the changing situation, the large number of vehicles involved, and the dispersion of the observation times, would minimize the probability of that happening. Two siren-sounding occurrences were noted in Fall-Winter of 1984-85 and seven in 198788. In none of these nine instances was an emergency vehicle on call, identifiable by a flashing whlte and red light, seen. The number of discrete soundings per occurrence was one, with a duration of about two to three seconds. In no case was it possible to identify the vehicle from which the sound was coming. However, in the rwo occurrences observed in 1984-85, a private vehicle was noted to use the opening in the traffic which resulted. In the other seven instances, drivers did not respond to the siren, and there was no alteration in the pattern of the vehicle flow. The results of this inquiry suggest, as the work of others such as McKelvie (1) and Trinkaus (3) have implied, that drivers' compliance with motor vehicle regulations may well be declining. First, there is what appears to be an increase in the use of sirens by drivers of nonemergency vehicles. And, second, there is seemingly a lessening of the rate of assent by drivers in yielding the right-of-way when they hear a siren. While this implies that there is some decay in adherence to motor vehicle regulations, with its explicit implication for motorists' safety, perhaps of more importance is the suggested implicit increase in the demise of overall concern for the well being of othen
Triggered Jovian radio emissions

Certain Jovian radio emissions seem to be triggered from outside, by much weaker radio waves from the sun. Recently found in the Voyager observations near Jupiter, such triggering occurs at hectometric wavelengths during the arrival of solar radio bursts, with the triggered emissions lasting sometimes more than an hour as they slowly drifted toward higher frequencies. Like the previous discovery of similar triggered emissions at the earth, this suggests that Jupiter's emissions might also originate from natural radio lasers.
The potential of amalgam condensation causing intrusion of capping materials into the pulp

Abstract Three base materials, Dycal, Hydrex, and Cavitec, were tested for resistance to intrusion into the pulp under simulated clinical conditions, including 37 °C. and 100 per cent relative humidity. These base materials resisted pulpal intrusion at their Gilmore initial set time when placed 1 mm. thick over an exposure of 2 mm. and subjected to 583 p.s.i. condensation pressure (3 pounds of force on a 2 mm. condenser). The initial set time for Hydrex is sensitive to variations in humidity. This material required more than twice as long (4½to5½ minutes) to set in the oral environment, when a rubber dam was used. Dycal and Cavitec were not as sensitive to variations in humidity.
The continuum of complicity: “Studying up”/studying power as a feminist, anti-racist, or social justice venture

Synopsis “Studying up” has a long tradition in the social sciences, especially in critical scholarship. Critical methodologies, however, do not fit well with studying up. Responding to a history of disadvantaged groups' exploitation by scholars, critical researchers – especially feminists – developed alternative methodologies involving shared authorship, honest and open exchange, or “giving voice” to those you study. None of these practices are appropriate when studying the powerful, leaving critical scholars who do this work in a challenging position. We use our ethnographic studies of a jail and an anti-crime organization to explore this challenge. We identify incidents researchers are likely to encounter in this work, examine how we handled them, and use our experiences to develop a continuum of complicity that can be utilized by researchers to evaluate their decision-making processes relevant to research subjects' (and their own) exercise of power over marginalized others. The continuum is a tool that can be utilized to address the professional strain and identity crises that gaps in the methodological literature can produce for feminist, anti-racist, and social justice-oriented researchers who study power. It is also useful for mapping power as it unfolds in the field.
Runtime Tracing of the Community Earth System Model: Feasibility Study and Benefits

Abstract The Community Earth System Model (CESM) is one of US's leading earth system modeling frameworks, which has decades of development history and was embraced by a large, active user community. In this paper, we first review the software development history of CESM and we explain the general objectives of performance analysis. Then we present an offline global community land model simulation within the CESM framework to demonstrate the procedure of runtime tracing of CESM using the Vampir toolset. Finally, we explain the benefits of runtime tracing to the general earth system modeling community. We hope those considerations can be beneficial to many other modeling research programs involving legacy high-performance computing applications.
11β-Hydroxysteroid dehydrogenase-2 is a high affinity corticosterone-binding protein

Abstract In addition to mineralocorticoid and glucocorticoid receptors, a third category of corticosteroid binding sites has been described in the kidney, the Type III binding protein. This intracellular binder has high affinity for corticosterone, but binds neither aldosterone nor synthetic glucocorticoids. Based on similarities in steroid specificity and kinetic parameters, we hypothesized that these corticosterone binding sites belong to the type 2 isoform of 11 β -hydroxysteroid dehydrogenase (11 β -HSD2). The goal of this study was to express the recombinant rabbit 11 β -HSD2 in mammalian cells and test if such cells acquire both NAD-dependent 11 β -HSD2 activity as well as high affinity corticosterone binding sites. Stably transfected CHO cell lines expressed high, NAD-dependent, unidirectional 11 β -HSD2 activity. At the same time, the transfected cells also acquired a large number of corticosterone-specific binding sites (1.21±0.3×10 6 ), whereas non-transfected cells had no corticosterone binding above background. The K d for corticosterone was 25±8 nM. Neither the glucocorticoid receptor (GR) agonists dexamethasone and RU 28362 nor the mineralocorticoid receptor (MR) agonist aldosterone bound to these sites. The steroid specificity of the binding sites, as determined by competing [ 3 H]corticosterone with unlabeled steroids, is identical to that of 11 β -HSD2: corticosterone≫11-hydroxyprogesterone>carbenoxolone>11 dehydrocorticosterone>cortisol>progesterone∼DOC⋙DEX>RU 28362∼aldosterone. These results strongly suggest that the previously described high affinity corticosterone binding sites are 11 β -HSD2. Thus, though Type III binding sites are not corticosteroid receptors as originally thought, they play an important role in regulating the activity of both mineralocorticoid- and glucocorticoid receptors.
A limited survey of various conjugate gradient methods for solving complex matrix equations arising in electromagnetic wave interactions

Abstract There exists a wide variety of conjugate gradient algorithms for solving the complex matrix equations arising in electromagnetic wave interactions. The objective of this paper is to describe several of these algorithms which we have found to be computationally efficient. Both the strong and weak points of each version of the conjugate gradient method are presented. The principal conclusion is that at present, there is no single algorithm that provides an efficient solution for all types of problems. The computer programs corresponding to the algorithms discussed in the paper are provided in the Appendix.
Nonfunctioning malignant pheochromocytoma associated with dermatomyositis: case report and literature review

A 42-year-old man with dermatomyositis presented with right-upper-quadrant dull pain and normal blood pressure for 10 days. Abdominal ultrasonography, abdominal computed tomography, and angiography revealed a retroperitoneal tumor with direct invasion to the liver and the diaphragm. The diagnosis of nonfunctioning malignant pheochromocytoma was made on the basis of clinical evidence. The tumor was removed en bloc with part of the diaphragm, the right lobe of the liver, the right adrenal gland, and the right kidney. Pathologic examination with immunohistochemical staining revealed a malignant pheochromocytoma growing exophytically from the right adrenal gland and invading the right lobe of the liver and the diaphragm. The postoperative course has been uneventful and no recurrence has been noted over a 6-month follow-up period.
Diet and Feeding Ecology of Woolly Monkeys in a Western Amazonian Rain Forest

I investigated the diet and feeding ecology of two social groups of woolly monkeys (Lagothrix lagotricha poeppigii) in Yasuni National Park, Ecuador between April 1995 and March 1996. Woolly monkeys in Yasuni were predominantly frugivorous, with fruits comprising ca. 77% of the yearly diet; the next most common food type in the diet was insect and other animal prey. The fruit diet of woolly monkeys in Yasuni is the most diverse yet recorded for any ateline primate, including spider monkeys (Ateles), which are often regarded as ripe fruit specialists: ≥208 distinct morphospecies of fruits were consumed by woolly monkeys either during the study or during several preceding months of pilot work. Nonetheless, close to one-third of the yearly diet came from just 3 plant genera—Inga,Ficus, and Spondias—and only 20 genera each contributed to ≥1% of the diet. For one study group, the proportion of ripe fruit in the diet each month was correlated with the habitat-wide availability of this resource, a pattern evidenced by several other ateline species. However, the relationship was not apparent in the second study group. The modal party size for feeding bouts on all food types was a single monkey, and, contrary to reports for other atelines, neither feeding party size nor the total number of feeding minutes that groups spent in food patches was well predicted by patch size. Both results highlight the independent nature of woolly monkey foraging. Given that woolly monkeys and closely-related spider monkeys focus so heavily on ripe fruits, their very different patterns of social organization are intriguing and raise the question of just how their ecological strategies differ. Two important differences appear to be in the use of animal prey and in the phytochemical composition of the ripe fruits that they consume: spider monkeys rarely forage for animal prey, and woolly monkeys seldom consume the lipid-rich fruits that are an important part of spider monkey diets.
Clients’ experiences of difference with therapists: Sustaining faith in psychotherapy

Informed by the research literatures on values and multiculturalism, this study was designed to investigate clients' experiences of difference with therapists. Using a qualitative method--grounded theory--a model was developed to capture the essence of these experiences of difference. Five clusters highlight the client processes of being vigilant for differences, feeling threatened by differences, minimizing differences and focusing on positive relational factors, discussing differences, and beneficial personal growth resulting from differences. The core category describes the importance of clients maintaining faith in themselves, the therapist, and the therapeutic technique as differences are negotiated. Contributions and implications for practice and research on issues of managing values, multicultural differences, and transference are discussed.
Democracy and the Thai Middle Class: Globalization, Modernization, and Constitutional Change

Although democratization in Thailand is often seen as an illustration of modernization theory, the extent of middle class support for democracy is actually unclear. The greatest advance for Thai democracy in the 1990s was the passage of the 1997 Constitution, more closely linked to economic globalization than modernization.
Effect of Salt Concentration on Regeneration Rate in Blepharisma Acclimated to High Salt Levels

SYNOPSIS. Individuals of Blepharisma intermedium (Rao A race) acclimated by prolonged growth in axenic medium containing 8X, 16X, 24X and 32X the concentration of salts in unit standard balanced salt solution (USBSS) used for fresh-water protozoans were tested for rate of regeneration at various salt concentrations, the time for 50% regeneration being used for comparisons. Blepharismas acclimated to axenic medium (of osmolality 10 × USBSS) containing 16X USBSS regenerated at about the same rate as those grown in axenic medium but were delayed at higher salt concentrations. The same was true for those grown in axenic medium containing 32X USBSS, except that the range of higher salt concentration tolerated was much greater. Those acclimated to higher salt concentrations were delayed in regeneration by exposure to lower salt concentrations tolerated by controls. Because growth was very slow in media of higher osmolal concentration, it was not possible to determine the internal concentration of salts in acclimated cells. The morphogenetic process as measured by rate of regeneration, appeared to be less sensitive to increased salt concentration than growth, as measured by cell division.
Stress Corrosion Cracking Initiation in Ferritic Stainless Steels in a Chloride Environment

Abstract The difference in stress corrosion cracking (SCC) susceptibility between high and low interstitial ferritic stainless steels (SS) (26Cr-1Mo) in chloride solutions is the result of the rela...
In vitro assessment of the toxicity of metal compounds

A review of the activity of metal compounds in mammalian cell transformation assays has been completed. Results from these assays appear to correlate well with the known carcinogenic activity displayed by specific metal compounds in vivo. Studies of cell transformation in vitro may provide information pertaining to the mechanism of the induction of carcinogenesis by certain metals.
Free-electron final-state model and angle-resolved photoemission from a Ag(111) surface

Angle-resolved photoemission spectra from a Ag(111) surface exhibit a strong dependence on photon energy for $h\ensuremath{\nu}$ extending from 11.6 to 40.8 eV that clearly demonstrates the nonvalidity of the one-dimensional density-of-states model. Trends in the positions of the peaks in the observed spectra are described within the accuracy of our computations by the initial-state band structure and a free-electron-like final state. No evidence is found for surface states nondegenerate with those of the bulk or narrowing of the bulk bands in the vicinity of the surface.
Synthesis of some monodeoxyfluorinated methyl and 4-nitrophenyl α-d-mannobiosides and a related 4-nitrophenyl α-d-mannotrioside

Treatment of methyl 3,4,6-tri-O-benzyl-2-O-(2,3,4-tri-O-acetyl-alpha-D-mannopyranosyl)-alpha -D- mannopyranoside with N,N-diethylaminosulfur trifluoride (Et2NSF3), followed by O-deacetylation and catalytic hydrogenolysis, afforded methyl 2-O-(6-deoxy-6-fluoro-alpha-D-mannopyranosyl)-alpha-D-mannopyranoside (8). Methyl 6-deoxy-6-fluoro-2-O-alpha-D-mannopyranosyl-alpha-D-mannopyranoside (11) was similarly obtained from methyl 3-O-benzyl-2-O-(2,3,4,6-tetra-O-acetyl-alpha-D-mannopyranosyl-alpha-D- mannopyranoside. 1,2,3,4-Tetra-O-acetyl-6-deoxy-6-fluoro-beta-D-mannopyranose (13), used for the synthesis of the 4-nitrophenyl analogs of 8 and 11, as well as their 3-O-linked isomers, was obtained by treatment of 1,2,3,4-tetra-O-acetyl-beta-D-mannopyranose with Et2NSF3. Treatment of 13 with 4-nitrophenol in the presence of tin(IV) chloride, followed by sequential O-deacetylation, isopropylidenation, acetylation, and cleavage of the acetal group, afforded 4-nitrophenyl 4-O-acetyl-6-deoxy-6-fluoro-alpha-D-mannopyranoside (18). Treatment of 13 with HBr in glacial acetic acid furnished the 6-deoxy-6-fluoro bromide 19. Glycosylation of diol 18 with 20 gave 4-nitrophenyl 4-O-acetyl-6-deoxy-6-fluoro-3-O- (21) and -2-O-(2,3,4,6-tetra-O-acetyl-alpha-D-mannopyranosyl)-alpha-D- mannopyranoside (23) in the ratio of approximately 2:1, together with a small proportion of a branched trisaccharide. 4-Nitrophenyl 4,6-di-O-acetyl-alpha-D-mannopyranoside was similarly glycosylated with bromide 19 to give 4-nitrophenyl 4,6-di-O-acetyl-3-O- and -2-O-(2,3,4-tri- O-acetyl-6-deoxy-6-fluoro-alpha-D-mannopyranosyl)-alpha-D-mannopyranosid e. The various di- and tri-saccharides were O-deacetylated by Zemplen transesterification.
The use of SPECT bone scans to evaluate patients with idiopathic jaw pain

Abstract Objective: The purpose of this study was to investigate the potential usefulness of single photon emission computed tomography (SPECT) bone scanning with technetium-99m methylene diphosphonate (Tc-99m MDP) in the diagnosis of idiopathic jaw pain. Unlike planar bone scanning, SPECT uses tomographic technology to provide 3-dimensional images, which are more useful in localizing small lesions. Study Design: Twenty patients, each with a diagnosis of chronic idiopathic jaw pain, were compared after SPECT bone scanning with 20 age-matched and gender-matched normal controls. Uptake was identified and compared in sites with previously detected jaw pathoses and jaw pain. Results: Nineteen of 20 patients with jaw pain evaluated with SPECT had positive scans, in contrast with 12 of 20 control subjects ( P P Conclusion: Patients with idiopathic jaw pain had a significantly greater frequency of positive SPECT bone scans when compared with normal controls. However, the sensitivity and specificity of SPECT bone scans in detecting painful sites were low. These findings suggest that SPECT bone scanning with Tc-99m MDP is not indicated as a routine imaging procedure for the detection of jaw pathoses, but may be considered as a potential research tool in the future study of chronic idiopathic jaw pain. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2000;90:750-7)
A study of grain boundary precipitate-free zone formation in an Al−Zn−Mg alloy

The effect of quench rate and boundary type on the width of precipitate-free zones in an Al-6.86 wt pct Zn-2.35 wt pct Mg alloy that was aged at two different temperatures was studied by transmission electron microscopy. The width of the precipitate-free zones increased with decreasing quench rate, but by a considerably smaller extent than that predicted from calculations using previous models based upon quenched vacancy profiles. The simple tilt-type boundaries were associated, in general, with narrower precipitate-free zones than those occurring at complex-type boundaries. The width of precipitate-free zones was also observed to decrease with increasing precipitate coverage in the boundary. A mechanism of precipitate-free zone formation based on the modification of the as-quenched vacancy profile by the vacancies generated due to grain boundary precipitation was proposed to explain the observed results.
Ionization mechanism of the ambient pressure pyroelectric ion source (APPIS) and its applications to chemical nerve agent detection

We present studies of the ionization mechanism operative in the ambient pressure pyroelectric ionization source (APPIS), along with applications that include detection of simulants for chemical nerve agents. It is found that ionization by APPIS occurs in the gas-phase. As the crystal is thermally cycled over a narrow temperature range, electrical discharges near the surface of the crystal produce energetic species which, through reactions with atmospheric molecules, result in reactant ions such as protonated water clusters or clusters of hydroxide and water. Reactant ions can be observed directly in the mass spectrometer. These go on to react with trace neutrals via proton transfer reactions to produce the ions observed in mass spectra, which are usually singly protonated or deprotonated species. Further implicating gas-phase ionization, observed product distributions are highly dependent on the composition of ambient gases, especially the concentration of water vapor and oxygen surrounding the source. For example, basic species such as triethylamine are observed as singly protonated cations at a water partial pressure of 10 torr. At a water pressure of 4 torr, reactive oxygen species are formed and lead to observation of protonated amine oxides. The ability of the APPIS source to detect basic molecules with high proton affinities makes it highly suited for the detection of chemical nerve agents. We demonstrate this application using simulants corresponding to VX and GA (Tabun). With the present source configuration pyridine is detected readily at a concentration of 4 ppm, indicating ultimate sensitivity in the high ppb range.
Behavior exchange in happy and unhappy marriages: A family cycle perspective

The behavioral exchange of unhappy ( n =24) and happy ( n =26) couples was compared along three dimensions: nature and frequency of behaviors exchanged, degree of reciprocity, and relationship between specific behavioral categories and marital satisfaction. The study also explored the behavioral exchange of couples in four stages of child rearing. Each day for 4 weeks, spouses independently recorded pleasing and displeasing relationship behaviors on the Spouse Observation Checklist. Analyses showed that unhappy, compared to happy, couples exhibited (1) lower rates of pleasing and higher rates of displeasing behaviors, (2) greater negative reciprocity, and (3) stronger relationships between displeasing behaviors and daily satisfaction. Communication Pleases and Companionship Activities differed significantly across child rearing stages.
A VHDL fault diagnosis tool using functional fault models

The development and implementation of an algorithm that forms the basis of a very-high-speed integrated circuit hardware description language (VHDL) fault diagnosis tool (VFDT) are discussed. Given a VHDL description, a compiler creates an internal representation suitable for simulation and fault diagnosis. VFDT diagnoses faults in this representation hierarchically using the stuck-at fault model at the first level and the arbitrary-failure model at the second level. It reasons from first principles by means of constraint suspension. Examples of fault diagnosis using the VFDT are described. >
Salinity-sensitive alkaline phosphatase activity in gills of the blue crab, Callinectes sapidus Rathbun

Abstract A levamisole-sensitive (Ki = 0.72 mM) alkaline phosphatase (pH optimum 9.1) and a levamisole-insensitive alkaline phosphatase (pH optimum 7.1) are present in gills of the blue crab Callinectes sapidus. Both enzymes are distinct from ouabain-sensitive ATPase. Specific activity for either phosphatase is greatest in the acinar tissue, which lines the branchial vessels. Histochemical localization of the enzymes confirmed this distribution. Activity of levamisole-sensitive alkaline phosphatase is affected by acclimation salinity. Vmax of the levamisole-sensitive alkaline phosphatase is greater in high-salinity crabs than in low-salinity crabs; apparent Km is not significantly different. The levamisole-sensitive alkaline phosphatase associated with the acinar tissue lining the branchial vessels may modulate the osmoregulatory response in blue crabs.
The developmental etiology and pathogenesis of Hirschsprung disease.

The enteric nervous system is the part of the autonomic nervous system that directly controls the gastrointestinal tract. Derived from a multipotent, migratory cell population called the neural crest, a complete enteric nervous system is necessary for proper gut function. Disorders that arise as a consequence of defective neural crest cell development are termed neurocristopathies. One such disorder is Hirschsprung disease (HSCR), also known as congenital megacolon or intestinal aganglionosis. HSCR occurs in 1/5000 live births and typically presents with the inability to pass meconium, along with abdominal distension and discomfort that usually requires surgical resection of the aganglionic bowel. This disorder is characterized by a congenital absence of neurons in a portion of the intestinal tract, usually the distal colon, because of a disruption of normal neural crest cell migration, proliferation, differentiation, survival, and/or apoptosis. The inheritance of HSCR disease is complex, often non-Mendelian, and characterized by variable penetrance. Extensive research has identified a number of key genes that regulate neural crest cell development in the pathogenesis of HSCR including RET , GDNF , GFRα1 , NRTN , EDNRB , ET3 , ZFHX1B , PHOX2b , SOX10 , and SHH . However, mutations in these genes account for only ∼50% of the known cases of HSCR. Thus, other genetic mutations and combinations of genetic mutations and modifiers likely contribute to the etiology and pathogenesis of HSCR. The aims of this review are to summarize the HSCR phenotype, diagnosis, and treatment options; to discuss the major genetic causes and the mechanisms by which they disrupt normal enteric neural crest cell development; and to explore new pathways that may contribute to HSCR pathogenesis.
Classification of positive inotropic agents

Although there is increasing recognition that all inotropic agents are not alike, they continue to be viewed in the generic sense because of the lack of a classification system. Analogous to the classification system proposed for the antiarrhythmic agents over 20 years ago, a classification system is proposed that categorizes inotropic agents according to their mechanisms of action. Agents are classified as those that augment contractility by increasing intracellular levels of cyclic adenosine monophosphate (class I); affect ion channels or pumps (class II); modulate intracellular calcium regulation (class III), and augment contractility through multiple pathways (class IV). This classification system does not suggest that some classes of inotropic agents might be more effective than others nor does it imply that potential beneficial effects are shared by all members of each class of drugs. However, it provides a framework for better understanding of the potential benefits and limitations of the traditional inotropic agents as well as the increasing number of new investigational drugs.
Evolving understanding of the immunopathogenesis of HIV.

Understanding of the immunopathogenesis of HIV infection is becoming more advanced as the activity of HIV infection in lymph nodes is appreciated and as improved virological measures permit more ac...
The philosophy of demographic policy in Latin America.

Until recent years Latin Americas were convinced that their countries were underpopulated. They saw vast expanses of land that were not being used; they felt that more dense settlement was necessary before communications could be build economically and internal markets developed; they observed that in the four hundred years since the Spanish conquest the rate of population growth had been rather slow - much slower for instance than that experienced by the United States. Furthermore in some countries the leaders felt that the backwardness of the Indian populations reflected biological inferiority and thus that progress could only be achieved through major infusions of European blood. Therefore in the nineteenth and early part of the twentieth centuries it was common for governments (and occasionally private groups) to promote immigration from Europe. In Brazil and Argentina immigration was in fact massive; in the other countries it represented only a trickle. (excerpt)
Economic development, drought, and famines: some limitations of dependency explanations

Drought is today a major instigator of famine disasters that developing countries suffer. Until recently scientists set great store in climatic theories of famine devastation. Over the past decade, climatic determinism has given way to a sociological thesis, putting famines connected with drought down fundamentally to political and economic causes of poverty rooted in colonial and neocolonial forms of capitalism. According to this thesis drought acts only as a catalyst of a situation long in the making. These ‘dependency explanations’, discussed below, trace over important links forming the causal chain. But they attend insufficiently to proximate (immediate) causes of famine and overlook risks from indigenous village institutions. Further, outbreaks of famine in developing countries opposed staunchly to capitalistic doctrines and practices lie beyond the explanatoru scope of dependency frameworls. These claims are elaborated and then directed to an assessment of research needs presented in the concluding section.
Declining susceptibilities of gram-negative bacteria to the fluoroquinolones: Effects on pharmacokinetics, pharmacodynamics, and clinical outcomes

Purpose Published evidence of rising gram-negative bacterial resistance to fluoroquinolone therapy is reviewed, with a focus on the potential need for revising pharmacokinetic–pharmacodynamic (PK–PD) targets in order to maintain acceptable clinical outcomes. Summary With a more than threefold increase in fluoroquinolone use among U.S. adults since the introduction of second- and third-generation (i.e., “respiratory”) fluoroquinolones 15 years ago, surveillance data indicate a decline in some gram-negative organisms' susceptibility to this antimicrobial class. These trends have raised concerns that the need to attain higher organism-specific minimum inhibitory concentrations (MICs) may lead to worse patient outcomes, even when MIC values are below current established “clinical breakpoints” for fluoroquinolone susceptibility. A growing body of evidence from PK–PD studies suggests that current fluoroquinolone dosing regimens are no longer adequate to achieve validated PK–PD targets. For example, a Monte Carlo simulation using PK data from U.S. hospitals showed decreasing rates of response to standard ciprofloxacin and levofloxacin i.v. dosing regimens among patients treated for infections with Escherichia coli and Klebsiella species. These findings suggest that currently accepted PK–PD targets may need to be revised for certain patient populations, including patients with bloodstream infections (BSIs). More research is needed to confirm the appropriateness of adjusting clinical breakpoints and other strategies to combat rising fluoroquinolone resistance. Conclusion The use of the fluoroquinolones has markedly increased since the introduction of the respiratory fluoroquinolones. Surveillance data and PK–PD studies have raised concerns about suboptimal patient outcomes with the use of fluoroquinolones for some gram-negative infections, particularly BSIs. PK–PD goals and clinical breakpoints may need to be revised for these infections.
Dispersion Polymerizations in Supercritical Carbon Dioxide

Conventional heterogeneous dispersion polymerizations of unsaturated monomers are performed in either aqueous or organic dispersing media with the addition of interfacially active agents to stabilize the colloidal dispersion that forms. Successful stabilization of the polymer colloid during polymerization results in the formation of high molar mass polymers with high rates of polymerization. An environmentally responsible alternative to aqueous and organic dispersing media for heterogeneous dispersion polymerizations is described in which supercritical carbon dioxide (CO2) is used in conjunction with molecularly engineered free radical initiators and amphipathic molecules that are specifically designed to be interfacially active in CO2. Conventional lipophilic monomers, exemplified by methyl methacrylate, can be quantitatively (>90 percent) polymerized heterogeneously to very high degrees of polymerization (>3000) in supercritical CO2 in the presence of an added stabilizer to form kinetically stable dispersions that result in micrometer-sized particles with a narrow size distribution.
On-Line Interaction and Why Candidates Avoid It

The Internet has properties that make possible increased interaction between citizens and political leaders. Interviews of campaign staff and analysis of U.S. candidate websites in 1996 and 1998, however, indicate that most political campaigns are resistant to using human-interactive features. I conceptualize interaction, offering that there are two kinds: human interaction and media interaction. More democratizing components of the medium, human interaction, are avoided in favor of media interaction because of the potential for a loss of control and ambiguity of campaign communication.
Religious nonprofit organizations: An examination of rescue missions and the homeless

Abstract The purpose of this study was to examine religiously based nonprofit organizations by focusing on rescue missions and their work with the poor and homeless. Member missions of the Internat...
The retinaldehyde reductase activity of DHRS3 is reciprocally activated by retinol dehydrogenase 10 to control retinoid homeostasis.

The retinoic acid-inducible dehydrogenase reductase 3 (DHRS3) is thought to function as a retinaldehyde reductase that controls the levels of all-trans-retinaldehyde, the immediate precursor for bioactive all-trans-retinoic acid. However, the weak catalytic activity of DHRS3 and the lack of changes in retinaldehyde conversion to retinol and retinoic acid in the cells overexpressing DHRS3 undermine its role as a physiologically important all-trans-retinaldehyde reductase. This study demonstrates that DHRS3 requires the presence of retinol dehydrogenase 10 (RDH10) to display its full catalytic activity. The RDH10-activated DHRS3 acts as a robust high affinity all-trans-retinaldehyde-specific reductase that effectively converts retinaldehyde back to retinol, decreasing the rate of retinoic acid biosynthesis. In turn, the retinol dehydrogenase activity of RDH10 is reciprocally activated by DHRS3. At E13.5, DHRS3-null embryos have ∼4-fold lower levels of retinol and retinyl esters, but only slightly elevated levels of retinoic acid. The membrane-associated retinaldehyde reductase and retinol dehydrogenase activities are decreased by ∼4- and ∼2-fold, respectively, in Dhrs3−/− embryos, and Dhrs3−/− mouse embryonic fibroblasts exhibit reduced metabolism of both retinaldehyde and retinol. Neither RDH10 nor DHRS3 has to be itself catalytically active to activate each other. The transcripts encoding DHRS3 and RDH10 are co-localized at least in some tissues during development. The mutually activating interaction between the two related proteins may represent a highly sensitive and conserved mechanism for precise control over the rate of retinoic acid biosynthesis.