cssi/SciSciGPT-SciSciNet huggingface dataset:
Polymerization of Deoxy-Sickle Cell Hemoglobin in High-Phosphate Buffer

Deoxy-sicklecell hemoglobin (HbS) polymerizes in 0.05 M phosphate buffer to form long helical fibers. The reaction typically occurs when the concentration of HbS is about 165 mg/ml. Polymerization produces a variety of polymorphic forms. The structure of the fibers can be probed by using site-directed mutants to examine the effect of altering the residues involved in intermolecular interactions. Polymerization can also be induced in the presence of 1.5 M phosphate buffer. Under these conditions polymerization occurs at much lower concentrations (ca. 5 mg/ml), which is advantageous when site-directed mutants are being used because only small quantities of the mutants are available. We have characterized the structure of HbS polymers formed in 1.5 M phosphate to determine how their structures are related to the polymers formed under more physiological conditions. Under both sets of conditions fibers are the first species to form. At pHs between 6.7 and 7.3 fibers initially form bundles and then crystals. At lower pHs fibers form macrofibers and then crystals. Fourier transforms of micrographs of the polymers formed in 1.5 M phosphate display the 32- and 64-A−1 periodicity characteristic of fibers formed in 0.05 M phosphate buffer. The 64-A−1 layer line is less prominent in Fourier transforms of negatively stained fibers formed in 1.5 M phosphate possibly because salt interferes with staining of the fibers. However, micrographs and Fourier transforms of frozen hydrated fibers formed in high and low phosphate display the same periodicities. Under both sets of reaction conditions HbS polymers form crystals with the same unit cell parameters as Wishner–Love crystals (a = 64 A, b = 185 A, c = 53 A). Some of the polymerization intermediates were examined in the frozen-hydrated state in order to determine whether their structures were significantly perturbed by negative staining. We have also carried out reconstructions of the frozen-hydrated fibers in high and low phosphate to compare their molecular coordinates. The helical projection of the reconstructions in low phosphate shows the expected 14-strand structure. In high phosphate the 14-strand fibers are also formed and their molecular coordinates are the same (within experimental error) as those of fibers formed in 0.05 M phosphate. In addition, the reconstructions of high-phosphate fibers reveal a new minor variant of fiber containing 10 strands. The polymerization products in 1.5 M phosphate buffer were generally indistinguishable from those formed in 0.05 M phosphate buffer. Micrographs of frozen hydrated specimens have facilitated the interpretation of previously published micrographs using negative staining.
Consonant Ordering in Down's Syndrome Phonology.

This paper explored one aspect of the phonology of a 4-yr-old child with Down's Syndrome. This child had a phonological constraint that ordered his consonants from those produced at the front of the mouth to those produced at the back of the mouth. This meant that in a CVC word, C1 could either be produced at the same place in the mouth as C2, or at a place more forward than C2, but that C1 could not be produced at a place in the mouth posterior to C2. It is argued in this paper that this Consonant Ordering Strategy (COS)--which is equivalent to Ingram's fronting strategy (Ingram, 1974a)--motivated all the consonant substitutions found in the subject's attempted pronunciations of CVC words. The paper concludes by showing the value of an analysis that recognize phonological strategies and larger-than-phoneme units.
Pancreas-kidney transplantation is associated with reduced fracture risk compared with kidney-alone transplantation in men with type 1 diabetes.

Both type 1 diabetes mellitus and end-stage renal disease are associated with increased fracture risk, likely because of metabolic abnormalities that reduce bone strength. Simultaneous pancreas–kidney transplantation is a treatment of choice for patients with both disorders, yet the effects of simultaneous pancreas–kidney and kidney transplantation alone on post-transplantation fracture risk are unknown. From the United States Renal Data System, we identified 11,145 adults with type 1 diabetes undergoing transplantation, of whom 4933 had a simultaneous pancreas–kidney transplant and 6212 had a kidney-alone transplant between 2000 and 2006. Post-transplantation fractures resulting in hospitalization were identified from discharge codes. Time to first fracture was modeled and propensity score adjustment was used to balance covariates between groups. Fractures occurred in significantly fewer (4.7%) of pancreas–kidney compared with kidney-alone transplant (5.9%) cohorts. After gender stratification and adjustment for fracture covariates, pancreas–kidney transplantation was associated with a significant 31% reduction in fracture risk in men (hazard risk 0.69). Older age, white race, prior dialysis, and pre-transplantation fracture were also associated with increased fracture risk. Prospective studies are needed to determine the gender-specific mechanisms by which pancreas–kidney transplantation reduces fracture risk in men.
Aortic blebs: Possible site of aneurysm rupture***

Although the growth and rupture of abdominal aortic aneurysms are commonly explained by Laplace's law, the final events that precede aneurysm rupture are not fully understood. Local excrescences within the wall of abdominal aortic aneurysms were observed in four of five patients studied with preoperative CT scanning, and were removed from six patients at the time of surgery. These protrusions were filled with thrombus, and on histologic examination marked attenuation of the aortic wall, focal loss of elastic fibers, and inflammatory cell infiltrates of lymphocytes, plasma cells, and occasional multinucleate giant cells were seen. The presence of these blebs and their microscopic characteristics suggest their potential as a mechanism for rupture and recognition of this deformity by use of abdominal CT scanning may indicate the necessity for prompt surgical intervention. Further careful clinicopathologic correlation is required to clearly establish these localized defects in the aneurysm wall as a cause for rupture.
Molecular basis for the lack of mimicry of Brucella polysaccharide antigens by Ab2γ antibodies

The crystal structure of the complex of an anti-Id Fab with an Fab specific for a Brucella polysaccharide antigen has previously been reported (Evans et al., 1994, J. Mol. Biol. 241, 691-705). To complement this study, the binding characteristics and immunological properties of this Ab2 and two others raised with a second anti-Brucella antibody were investigated, including quantitative kinetic measurements by surface plasmon resonance. The affinities of the Fabs from the Ab2s for the Ab1s were three orders of magnitude greater than those estimated for the antigen, but the Ab2s failed to induce antigen-binding Ab3s, that is, they were of the Ab2gamma type. The avidities of the Ab1s for antigen were however within one order of magnitude of their avidities for Ab2. Tests of 16 other anti-Brucella polysaccharide antibodies showed that the two idiotopes were not present in them, and in confirmation of the lack of a dominant idiotope, N-terminal sequencing of their H and L chains showed a wide variety of V genes were employed in the immune response to the Brucella polysaccharides. The failure of the Ab2 to induce antigen-reactive Ab3 thus appears to be due to neither intrinsic affinity nor idiotope frequency, but arises instead from structural reasons, for example, the incomplete penetration of the Ab2 into the binding-site cleft of the Ab1. The surface topography of polysaccharide antigens and their binding-sites thus appears to be especially difficult for Ab2s to mimic and will restrict their routine use as surrogates for T-cell independent polysaccharide antigens.
Chronological Age and Length of Delay as Determinants of Delayed Matching-to-Sample and Oddity Performance in Children

-The effects of length of delay and chronological age on children's delayed matching-to-sample and oddity performance were investigated in two separate experiments. In the first experiment, 112 children, 70 to 80 mo. in age, were trained on either a matching or oddity task which was either simultaneous or involved a delay of 0, 6, or 14 sec. In the second experiment, a 6-sec. delayed marching or oddity task was used to investigate the performance of 84 children divided equally into 70-80 mo., 90-100 mo., and 125-135 mo. age groups. Accuracy of performance under both the matching and oddiry tasks decrecued w ~ t h increases in delay value, and increased with increasing chronological age However, matching performance was superior 10 oddity for all delay values and chronological age groups smdied.
Properties of sputtered amorphous silicon/crystalline silicon solar cells

DC magnetron sputtering of amorphous silicon (a-Si), using an n-type silicon target, onto p-type crystalline silicon (c-Si) substrates was found to result in heterojunction solar cells. The process yielded 10.7% efficient solar cells, having a short-circuit current density (j/sub sc/) of 34 mA/cm/sup 2/ and an open circuit voltage (V/sub oc/) of 0.55 volts. The a-Si/c-Si structure had good junction characteristics, having a zero bias depletion width of 0.65 /spl mu/m in c-Si. The photovoltaic (PV) properties of the devices have been investigated for a-Si thickness, c-Si resistivity and substrate temperature. The amorphous/crystalline interface was found to be a limiting factor in device performance, and this was studied by both processing and electrical tests. The effect of interface traps due to sputtering induced damage has been studied by thermally stimulated capacitance (TSCAP) measurements.
What are the units of storage in visual working memory

An influential theory suggests that integrated objects, rather than individual features, are the fundamental units that limit our capacity to temporarily store visual information (S. J. Luck & E. K. Vogel, 1997). Using a paradigm that independently estimates the number and precision of items stored in working memory (W. Zhang & S. J. Luck, 2008), here we show that the storage of features is not cost-free. The precision and number of objects held in working memory was estimated when observers had to remember either the color, the orientation, or both the color and orientation of simple objects. We found that while the quantity of stored objects was largely unaffected by increasing the number of features, the precision of these representations dramatically decreased. Moreover, this selective deterioration in object precision depended on the multiple features being contained within the same objects. Such fidelity costs were even observed with change detection paradigms when those paradigms placed demands on the precision of the stored visual representations. Taken together, these findings not only demonstrate that the maintenance of integrated features is costly; they also suggest that objects and features affect visual working memory capacity differently.
A Theoretical Study of in vivo Lesion Repair Using a Controlled-release Device

A theoretical model of lesion remineralization predicts that in vivo caries repair can be effected in a five-day period by means of a controlled- and sustained-release device containing calcium, phosphate, and fluoride. The calculations detail an 80% repair before the remineralization process stops. However, the fluoridated hydroxyapatite formed is calculated to be about 20% more resistant to future attack than is hydroxyapatite, making effective repair complete. Optimal flux (W) conditions for repair of 100 μm lesions are WCa = 1.0 x 10-6 kglm2s, stoichiometric phosphate, and WF = 2.0 × 10-9 kg/ m2s.
Growth of the vacuoleless mutant of Tetrahymena thermophila NP1 in phytate

Phytate, the salt form of phytic acid, is the major store of phosphate in seeds and grain. Since non-ruminant farm animals poorly digest phytate, it is also a source of environmental phosphate contamination in agricultural areas. We are using Tetrahymena, a ciliated protist with multiple routes for nutrient assimilation, as a model to investigate the contribution of heterotrophic protists to the environmental cycling of phosphate from phytate. This ciliate has the ability to grow on phytate as the sole phosphate source (Ziemkiewicz, H. T., Johnson, M. D. & Smith-Somerville, H. E. 2002. J. Eukaryot. Microbiol., 49:428). Tetrahymena thermophila NP1, a temperature-sensitive vacuoleless mutant (ATCC #50202), provides a way to separate membrane transport from uptake through phagosomes, and to assess the importance of each mechanism. This cell grows equally well at the permissive and non-permissive temperatures with either phytate or inorganic phosphate as the phosphate source. Our results demonstrate that phagosomes are not required to use the phosphate from phytate.
Vacillation, Sudden Warmings and Potential Enstrophy Balance in the Stratosphere

The balance of potential enstrophy and its relationship to vacillation cycles and the sudden warming is studied for a beta-channel model of the stratosphere. It is shown that the mean flow cannot be steady in the presence of large-amplitude quasi-geostrophic waves (approximately 1-0.25 geopotential kilometers /gpkm/) when any dissipation is present, and the maximum wave amplitude allowed is approximately 2 gpkm. If wave forcing (transience plus dissipation) is artificially maintained, the mean flow decelerates slowly at first then explosively as the potential vorticity gradient of the basic state is wiped out over the channel. This process is called wave saturation. The initial phase of the explosive deceleration resembles both the observed and modeled mean flow evolution during a sudden stratospheric warming. A simple vacillation model based upon these ideas shows remarkable similarity to the results of Holton and Mass (1976) and Davies (1981).
Occupational prestige and changing higher educational policy

Abstract This article examines the impact of higher education policy and family background on occupational prestige. It argues that changes in higher education policy have had a significant effect on the relative importance of educational attainment in determining occupational prestige, and that family background continues to have a significant effect on educational attainment and occupational prestige. The sample for this study is drawn from the Panel Study of Income Dynamics. The sample consists of white male household heads who were between 18 and 64 years of age in 1972. The sample was subdivided into three cohorts by age and each cohort was selected to correspond to a distinct era of higher educational policy. This study uses the following periods of higher education policy: (1) The era preceding World War II, (2) the era after World War II, essentially the period of the G.I. Bill, and (3) the era following passage of the National Defense Education Act. The results from this study indicate that educational attainment does have a smaller effect on occupational prestige for the youngest cohort. This result suggests that education per se is relatively less important when a larger share of the labor force has acquired greater years of schooling. Our results also show that family background factors tend to affect occupational prestige via educational attainment. Thus, educational attainment tends to be a significant transmission mechanism relating family background and occupational status. Therefore, the results of this study indicate that family background variables have important effects on labor-market success.
Numerical performance of the parabolized ADM formulation of general relativity

In a recent paper [Vasileios Paschalidis, Phys. Rev. D 78, 024002 (2008).], the first coauthor presented a new parabolic extension (PADM) of the standard 3+1 Arnowitt, Deser, Misner (ADM) formulation of the equations of general relativity. By parabolizing first-order ADM in a certain way, the PADM formulation turns it into a well-posed system which resembles the structure of mixed hyperbolic-second-order parabolic partial differential equations. The surface of constraints of PADM becomes a local attractor for all solutions and all possible well-posed gauge conditions. This paper describes a numerical implementation of PADM and studies its accuracy and stability in a series of standard numerical tests. Numerical properties of PADM are compared with those of standard ADM and its hyperbolic Kidder, Scheel, Teukolsky (KST) extension. The PADM scheme is numerically stable, convergent, and second-order accurate. The new formulation has better control of the constraint-violating modes than ADM and KST.
Acute fracture simulating a symptomatic bipartite patella: Report of a case

A recent presentation by Weaver' has called attention to the entity of the symptomatic bipartite patella. In that paper, the symptom complex and treatment were discussed. The points of differentiation of an acute fracture from a symptomatic bipar tite patella were also briefly presented. We presented the following case, to underscore the fact that an acute fracture of the superolateral patella can clinically and radiographically simulate a symptomatic bipartite patella (Class III2).
Post-tetanic potentiation in Aplysia sensory neurons.

Abstract Post-tetanic potentiation (PTP) lasting several minutes is produced by high frequency intracellular activation of mechanosensory neurons. Control procedures suggest that the PTP involves a homosynaptic mechanism, restricted to the active synapses. The capacity for PTP appears to be a general property of mechanosensory neurons in this animal since it is found in separate sensory populations innervating the tail, head, and siphon of Aplysia .
Opportunistic Cooperative Networking: To Relay or Not To Relay?

This paper considers opportunistic cooperative networking (OCN) in wireless ad hoc networks, with a focus on characterizing the desired tradeoff between the probing cost for establishing cooperative relaying and hence higher throughput via opportunistic cooperative networking. Specifically, opportunistic cooperative networking is treated as an optimal stopping problem with two-levels of incomplete information. Cases with or without dedicated relays are considered, and the existence of the optimal strategies for both cases are established. Then, it is shown that for the case with dedicated relays, the optimal strategy exhibits a threshold structure, in which it is optimal to probe the dedicated relay when the signal-to-noise ratio (SNR) of the source-relay link exceeds some threshold. For the case without dedicated relays, under more restrictive conditions, the optimal strategy is also threshold-based, in the sense that it is optimal to probe potential relays when the SNR of the source-destination link lies between two thresholds. Furthermore, these strategies can be implemented in a distributed manner.
Thermodynamic properties for the alternative refrigerants

Abstract Models commonly used to calculate the thermodynamic properties of refrigerants are summarized. For pure refrigerants, the virial, cubic, Martin-Hou, Benedict-Webb-Rubin, and Helmholtz energy equations of state and the extended corresponding states model are discussed. High-accuracy formulations for 16 refrigerants are recommended. These models may be extended to mixtures through the use of mixing rules applied either to the parameters of the equation of state or to some property of the mixture components. Mixtures of a specific composition may also be modeled as a pseudo-pure fluid. Five mixture models, employing four distinct approaches, have been compared by a group working under the auspices of the International Energy Agency. These comparisons show all five models to be very capable in representing mixture properties. No single model was best in all aspects, but based on its combination of excellent accuracy and great generality, we recommend the mixture Helmholtz energy model as the best available. Experimental data are essential to both fit the adjustable parameters in property models and to assess their accuracy. We present a survey of the data available for mixtures of the HFC refrigerants R32, R125, R143a, R134a, and R152a and for mixtures of the natural refrigerants propane, butane, isobutane, and carbon dioxide. More than 60 data references are identified. Further data needs include caloric data for additional mixtures, comprehensive pressure-density-temperature data for additional mixture compositions, and improved accuracy for vapor-liquid equilibria data.
An on-line customer information system at a gas-utility company

Abstract Since about 1970, there has been a significant trend among large organizations in moving from a manual system or semiautomatic system that first prepares source data and then processes it in a batch environment to an online automatic system that receives and processes data entered directly at the office. This paper describes the course of events during the development of such an on-line system that processes customer orders at a large gas utility company. One significant outcome of the conversion from the previous manual system to the on-line system was a large reduction in the work force required for processing customer order; this resulted in great savings in labor and material costs.
Are All Interferons the Same for Therapy in Polycythemia Vera

The use of recombinant interferons (rIFNs) for myeloproliferative neoplasms (MPNs) has increased significantly in the past 20 years, especially for polycythemia vera (PV) and essential thrombocythemia (ET). In PV, substantial change in the JAK2 allele burden (found in virtually all cases of PV and in approximately half of patients with ET) has occurred. This observation has not been consistently noted in patients treated with rIFN-a2b. The issue as to whether there is a qualitative or a quantitative difference is relevant for the treatment of ET and PV. As background, there are 3 types of interferons (IFNs) of major clinical interest. Type 1, which includes (a,b) or “viral interferons,” type 2 or “immune interferon,” and the recently described type 3 interferons (g,1, 2, and 3). Type 3 IFNs have similar activity as type 1. Alpha IFNs are primarily used in hematologic practice because of their wide ranging biologic and hematopoietic effects. They suppress normal hematopoietic progenitor cells to form colony units in vitro, might stimulate dormant hematopoietic cells to cycle (thus making them more susceptible to the effects of chemotherapeutic agents), inhibit erythroid progenitors and erythroid burst-forming units in vitro, and produce morphologic and biochemical changes in megakaryocytes, including megakaryocyte proliferation and thrombopoietin-induced receptor signaling. They also antagonize platelet-derived growth factor activity and affect JAK-STAT signaling. There are 2 types of pegylated IFNa (PEG-rIFNa) in clinical practice, PEG-rIFN-a2a (PEGASYS) and PEG-rIFN-a2b (PEGIntron). PEG-rIFN-a2b has an unstable urethane bond between the pegylated portion and the IFN molecule and thus is more likely to
Multiplicity of Antioxidant Enzyme Catalase in Mouse Liver Cells

Multiplicity of catalase activity has been observed in crude homogenates from the tissue and cell lines of mouse liver by ethanol/Triton X-100/heat treatment. The five enzymatically active catalase bands were designated as CAT1, CAT2, CAT3, CAT4, and CAT5 with a nondenatured molecular mass of 270kDa, 258kDa, 229kDa, 210kDa, or 197kDa, respectively. Cultured mouse liver cell lines, mouse liver tissue homogenate, and pure mouse liver catalase showed only one catalase band (CAT1) after ethanol/Triton X-100 treatment at 4 degrees C for 72 hr. The same treatment but incubated at 37 degrees C for 72 hr yielded three bands (CAT2, CAT4, CAT5) in normal cell line, only one band (CAT5) in MNNG-transformed and SV40-transformed cells, two bands (CAT1, CAT4) in mouse liver tissue homogenates, and two bands (CAT1, CAT3) in pure mouse liver catalase. These five catalase bands were further biochemically characterized. The CAT1, CAT2, and CAT3 are sensitive to heat (68 degrees C, 1 min), while CAT4 and CAT5 are rather heat resistant. The sensitivity to catalase inhibitors, such as aminotriazole, azide, or cyanide varies among the isoforms. Protease inhibitors could prevent the formation of CAT3 and CAT4, but not CAT5. Treatment with protease, however, removed all forms of catalase except CAT5. We conclude from this study that the appearance of different catalase bands is likely due to epigenetic modification of the protein, particularly proteolysis. The lowered catalase activity in transformed cells might also be attributable to the loss of two catalase isoforms.
Craniofacial form and performance of the canid skull during prey killing

Wild canids exhibit a wide range of feeding and predatory behaviors. Although teeth are highly informative about diet, the morphology of the craniofacial skeleton is likely to play an important role in the mechanics of prey capture. Short, broad snouts are associated with large bite forces for subduing large prey, and long, narrow snouts are associated with fast-closing jaws for capturing small prey. Theoretical analyses suggest that, all things being equal, long, narrow jaws will be weaker than shorter, broader jaws. The exact nature of these relationships remains to be uncovered, however. We measured dimensions of the upper jaws in 33 species of wild canids classified into 1 of 3 dietary categories: (1) small vertebrate specialists, (2) generalists/omnivores, and (3) large vertebrate specialists. Analysis of variance was used to test whether jaw dimensions differed among groups, and analysis of covariance was used to test whether these relationships held when body size was accounted for. To test the effects of skull shape on ability to resist loads generated during biting, we used 3D finite element analysis (FEA). Models were constructed from CT slices of skulls from 3 extant African canids that exhibit different hunting preferences and skull morphologies: African wild dog Lycaon pictus (broad–faced, large mammal specialist); Ethiopian wolf, Canis simensis (narrow-faced, small mammal specialist); and black-backed jackal, Canis mesomelas (generalized predator). Our FE experiments simulated loading schemes experienced during hunting, such as bilateral Journal of Veterinary Behavior (2009) 4, 60-66
The sodium and potassium exchange between intact frogs and their environment.

Intact living frogs (Rana pipiens) were partially immersed in dilute salt solution labeled with K42 or Na24 or, alternatively, injected with Ringer’s fluid containing the appropriate isotope and then partially immersed in unlabeled dilute salt. Before isotopic equilibrium, the animals were sacrificed and specific activities of K42 and Na24 were determined for medium, skin, plasma, and other tissues. With Na24, entering from the medium or escaping to the medium, specific activities of the skin approach that of the plasma. For K42, entering from the medium, the specific activity exceeds that of the plasma. The results are interpreted as indicating that the exchange rate for Na is greater plasma to skin than medium to skin, with the reverse situation for K. Values are given for average Na, K, and Cl contents of the various organ systems.
Organizational Environments and the Multinational Enterprise

Multinational enterprises (MNEs) serve as catalysts for reconceptualizing organization-environment relations because they operate simultaneously in multiple nations. We argue that subsidiaries of MNEs face dual pressures: They are pulled to achieve isomorphism with the local institutional environment, and they also face an imperative for consistency within the organization. We develop hypotheses regarding the factors that influence the structures and processes of MNEs. Based on an examination of the pressures imposed on MNEs. We offer a refined concept of organizational environments as complex and fluid, and we suggest implications for future research in organization theory.
A Comprehensive Model of Human Ear for Analysis of Implantable Hearing Devices

A finite element (FE) model of the human ear including the ear canal, middle ear, and spiral cochlea was constructed from histological sections of human temporal bone. Multiphysics analysis of the acoustics, structure, and fluid coupling in the ear was conducted in the model. The viscoelastic material behavior was applied to the middle ear soft tissues based on dynamic measurements of tissues in our laboratory. The FE model was first validated using the experimental data obtained in human cadaver ears, and then used to investigate the efficiency of the forward and reverse mechanical driving with middle ear implant, and the passive vibration of basilar membrane (BM) with cochlear implant placed in the cochlear scala tympani. The middle ear transfer function and the cochlear function of the BM vibration were derived from the model. This comprehensive ear model provides a novel computational tool to visualize and compute the implantable hearing devices and surgical procedures.
Spatial patterns of Douglas-fir and aspen forest expansion

Spatial patterns, rates, and density of encroaching forests into adjacent grasslands have important implications for long-term land use management and resource planning. This study examines the effects of Douglas-fir (Pseudotsuga menzeisii) and aspen (Populus tremuloides) regeneration mechanisms on sucker and seedling spatial patterns, distance from adult trees, and density in encroaching forests. A total of 8,924 aspen suckers and 1,244 Douglas-fir seedlings were counted and mapped in 2,920 quadrats (5 m × 5 m) in 106 plots along a lower forest-grassland ecotone in the Centennial Valley, MT, USA. Sucker and seedling spatial patterns were analyzed using Morisita’s I index. Average sucker and seedling density per quadrat and distance from adult trees were estimated for each plot and compared between aspen-dominated plots and Douglas-fir-dominated plots using ANOVA tests. Aspen suckers were established in a clustered spatial pattern at a significantly higher density and a significantly shorter distance from the adult trees. In contrast, Douglas-fir seedlings were established in varying spatial patterns at a significantly lower density and a significantly greater distance from the adult trees. Forest encroachment into the adjacent grassland in the Centennial Valley is occurring in contrasting patterns and at varying rates and densities due to the difference in aspen and Douglas-fir regeneration mechanisms.
Spontaneous formation of nanoparticle stripe patterns through dewetting

Significant advancement has been made in nanoparticle research, with synthetic techniques extending over a wide range of materials with good control over particle size and shape1,2,3,4,5,6. A grand challenge is assembling and positioning the nanoparticles in desired locations to construct complex, higher-order functional structures. Controlled positioning of nanoparticles has been achieved in pre-defined templates fabricated by top–down approaches7,8. A self-assembly method, however, is highly desirable because of its simplicity and compatibility with heterogeneous integration processes. Here we report on the spontaneous formation of ordered gold and silver nanoparticle stripe patterns on dewetting a dilute film of polymer-coated nanoparticles floating on a water surface. Well-aligned stripe patterns with tunable orientation, thickness and periodicity at the micrometre scale were obtained by transferring nanoparticles from a floating film onto a substrate in a dip-coating fashion. This facile technique opens up a new avenue for lithography-free patterning of nanoparticle arrays for various applications including, for example, multiplexed surface-enhanced Raman substrates and templated fabrication of higher-order nanostructures.
Modeling of capacitor impedance in switching converters

Switched capacitor (SC) converters are gaining acceptance as alternatives to traditional, inductor-based switching power converters. Proper design of SC converters requires an understanding of all loss sources and their impacts on circuit operation. In the present work, an equivalent resistance method is developed for analysis, and equivalent resistance formulae are presented for various modes of operation. Quasiresonant converters are explored and compared to standard SC converters. Comparisons to inductor-based switching power converters are made. A number of capacitor technologies are evaluated and compared for applications to both SC converters and inductor-based converters. The resulting model can be used to accurately predict and optimize converter performance in the design phase.
Neoclassical and Institutional Economics as Foundations for Human Resource Development Theory.

In an effort to more comprehensively understand economics as a foundation of human resource development (HRD), this article reviews economic theories and models pertinent to HRD research and theory building. By examining neoclassical and neoinstitutional schools of contemporary economics, especially the screening model and the internal labor market theory, it is argued that economic theories not only provide a foundation but also have important implications to HRD theory, research, and practice. Broadening research directions may be fruitful and provocative in expanding HRD’s theoretical base as well as practical applications in organizations.
HYDROLOGIC CONNECTIVITY AND THE MANAGEMENT OF BIOLOGICAL RESERVES: A GLOBAL PERSPECTIVE

Increasingly, biological reserves throughout the world are threatened by cumulative alterations in hydrologic connectivity within the greater landscape. Hydrologic connectivity is used here in an ecological sense to refer to water-mediated transfer of matter, energy, and/or organisms within or between elements of the hydrologic cycle. Obvious human influences that alter this property include dams, associated flow regulation, groundwater extraction, and water diversion, all of which can result in a cascade of events in both aquatic and terrestrial ecosystems. Even disturbances well outside the boundaries of reserves can have profound effects on the biological integrity of these “protected” areas. Factors such as nutrient and toxic pollution and the spread of nonnative species are perpetuated by hydrologic connectivity, and their effects can be exacerbated by changes in this property. Hydrological alterations are now affecting reserves through increasingly broad feedback loops, ranging from overdrawn aquife...
On critical circle homeomorphisms

We prove that an analytic circle homeomorphism without periodic orbits is conjugated to the linear rotation by a quasi-symmetric map if an only if its rotation number is of constant type. Next, we consider automorphisms of quasi-conformal Jordan curves, without periodic orbits and holomorphic in a neighborhood. We prove a “Denjoy theorem” that such maps are conjugated to a rotation on the circle.
On differences in how operations and supply chain managers approach quality management

In this research, we administered surveys to operations and supply chain managers from different companies to better understand how they approached quality management. The underlying research question was whether the increased emphasis in supply chain management in the workplace had implications for how quality management is practiced and how quality-related values are emphasised. We found that those who identified themselves as supply chain managers utilised and emphasised quality tools and values to a greater extent than those who identified themselves as operations managers. The tools emphasised by supply chain managers included benchmarking, complaint resolution, design for the environment, ERP, supplier development, focus groups, and supply chain management. The primary theoretical implication of this study is that there exists an emerging field that we can term ‘supply chain quality’. This study provides a preliminary outline of the domain of this field.
Venus on Wheels: Two Decades of Dialogue on Disability, Biography, and Being Female in America.

Venus on Wheels: Two Decades of Dialogue on Disability, Biography, and Being Female in America. Gelya Frank .Berkeley: University of California Press, 2000. ix. 284 pp., photographs, notes, references, index.
The atopic march: what's the evidence?

Objective To review and compile data from published studies that provide support for the existence of the atopic march. Data Sources Relevant articles and references found via a PubMed search using the following keywords: atopic march, allergic march, atopic dermatitis, eczema, atopic eczema, atopy, rhinitis, wheeze, bronchiolitis , and asthma . Study Selection All articles were reviewed and the most relevant were selected for inclusion in this review and for the compilation and graphical presentation of disease trends. Results Data on the prevalence of each phenotype of the atopic march confirm the temporal pattern of progression from eczema to allergic rhinitis and asthma. However, the atopic march as it is currently defined, is lacking precision, which affects its usefulness. Early events in the atopic march, such as eczema, may be more useful with more careful refinement of the phenotype into atopic and nonatopic eczema. Conclusion Evidence supports that the atopic march is a useful paradigm to describe the clinically observed progression of atopy in certain children. There may be more precise phenotypes of the early stages of the atopic march that may improve its utility in predicting the development of later atopic, comorbid chronic disease.
Intratubular germ cell neoplasms of the testis and bilateral testicular tumors: clinical significance and management options.

Objectives : Intratubular germ cell neoplasia (ITGCN) is the precursor lesion for invasive testicular germ cell tumors (TGCTs) of adolescents and young adults. The rising incidence of these tumors has prompted a rigorous investigation of the etiology, diagnosis and management of ITGCN. Bilateral testicular cancer is closely linked with ITGCN, as patients with unilateral testicular cancer are at the highest risk for a future malignancy in the contralateral testicle. Methods : A literature review directed at ITGCN and bilateral testis cancer was performed using the Medline/PubMed database. Our review focused on the pathogenesis, risk factors, diagnosis and treatment regimens utilized. Results : Major advances have been made in the understanding of ITGCN over the past 30 years. There is evidence that TGCTs arise from ITGCN, ITGCN is closely related to fetal gonocytes, and that events in pre- and perinatal period may result in abnormal persistence of fetal gonocytes leading to ITGCN and subsequent TGCT. Controversy exists regarding the need to biopsy men at increased risk of TGCT, as well as the best approach to managing patients with known ITGCN. Bilateral testicular cancer has excellent outcomes in the current era of platinum-based chemotherapy. Conclusion : The optimal management of patients at risk for ITGCN and future TGCT is still a matter of debate. Individualization of management, including biopsy and treatment, should be based on risk factors for TGCT, compliance with potential surveillance, and patient preferences particularly with regard to fertility.
Innovative tailings management for marine ferromanganese nodule and crust processing

Three factors have significantly increased the likelihood that manganese nodule and crust resources will be mined in the near future. These are (i) the legal clarification provided by the Law of the Sea Treaty now in full effect, (ii) the rapid economic growth in East Asia and (iii) the sharp rise in world cobalt prices. The Chinese Ocean Mining Company has announced plans to begin mining and is looking at joint venture possibilities with American companies. One of the major concerns with marine mining development is environmental. Current studies show 80% of the environmental effect to be associated with ore processing, particularly tailings disposal. New work indicates that tailings from proposed hydrometallurgical processing can be made into useful construction products. These include tiles, ceramics, coatings, resin castings for plumbing fixtures, additives to strengthen concrete, stack gas cleaners, rust-proofing and antibiofouling coverings. The economics of such a venture look favorable to the point that costs of tailings disposal should be zero or cash-generating on the basis of revenues from tailings products. This approach is an innovative strategy for tailings management and reduces potential environmental damage associated with marine mining.
Intensity fluctuation for waves behind a phase screen: a new asymptotic scheme

A new asymptotic scheme is presented through the computation of 〈I2〉and 〈I1I2〉 for waves behind a random phase screen with a power-law correlation. It illustrates the basic idea for an effective new expansion technique that yields a considerably faster convergent asymptotic series for intensity moments in the strong-fluctuation regime. This scheme can also be generalized to the computation of various statistical moments of intensity and log-intensity in continuous media with a power-law spectrum.
Creating MAGIC: system for generating learning object metadata for instructional content

This paper presents our latest work on building a system called MAGIC (Metadata Automated Generation for Instructional Content) that will automatically identify segments and generate critical metadata conforming with the SCORM (Sharable Content Object Reference Model) standard for instructional content. Various content analytics engines are utilized to automatically generate key metadata, which include audiovisual analysis modules that recognize semantic sound categories and identify narrators and informative text segments; text analysis modules that extract title, keywords and summary from text documents; and a text categorizer that classifies a document according to a pre-generated taxonomy. With MAGIC, instructional content developers can generate and edit SCORM metadata to richly describe their content asset for use in distributed learning applications. Experimental results obtained from collections of real data from targeted user communities will be presented.
Is Foreign Aid Conditioned upon Institutional Reform

Multilateral organizations increasingly claim to be conditioning foreign aid on institutional reform of the recipient country. We test whether increases in aid flows are related to current and future institutional improvements by relating Economic Freedom measures of the quality of countries' institutions to foreign aid flows during the 1973 period through the 2002 period. Consistent with binding conditionality, we find that the amount of aid flowing to a recipient country is positively related to future improvements in its economic institutions. Moreover, these effects appear to be strongest for improvements in monetary policy and the business environment, precisely those institutions most often targeted. These results occur for aid from individual donor countries but not from multilateral organizationslateral organizations and from individual donor countries.
Immunochemical studies of organ and tumor lipids. XIX. Cytolytic action of antibodies directed against cytolipin R

Rabbit antisera to rat lymphosarcoma contain antibodies that are cytolytic for rat erythrocytes in the presence of complement. The reaction can be inhibited completely by pure cytolipin R showing that (a) immune hemolysis can be mediated through lipid determinants in the membrane, and (b) that cytolipin R determinants are present in the intact erythrocyte membrane and exposed on the surface. Optimal conditions for measurement of cytolysis in this system based on release of (51)Cr are described. Degrees of specificity of a number of different antilymphosarcoma sera are shown, based on inhibition of cytolysis by cytolipin R, cytolipin K, cytolipin H, cytolipin F (F-hapten), glucocerebroside, galactocerebroside, ceramide trisaccharide (cer-glu-gal-gal), and a mixed brain ganglioside preparation. The data suggest that cytolytic antibodies and agglutinating antibodies in these antisera are distinctive despite their common specificity for cytolipin R. Lymphosarcoma cells are more effective than erythrocytes in absorbing cytolytic antibodies.
New Directions in the FDA Regulation of In Vitro Diagnostic Devices

Since 1976, the Food and Drug Administration has been involved actively in the regulation of in vitro diagnostic devices. Regulation involves a series of premarket and postmarket controls designed to assure that tests meet minimum thresholds of performance and are labeled properly. The review program for medical devices recently has undergone a variety of changes to produce more effective use of its regulatory tools.
Harmonic balance approach for rotorcraft with both unsteady and unknown rotor speed

The coupled flap-lag equations of motion for a system of a Q rigid bladed rotor with engine dynamics included are derived. For this system, the azimuth position \y becomes a generalized coordinate. The equations are solved by a completely numerical harmonic balance. A new approach for this method, based on space-domain Fourier series, is presented. This approach has the advantage that the period of the functions is always known, T=2n. In the traditional approach, if the rotor speed is unknown, the period is also unknown. Furthermore, this numerical harmonic balance utilizes an iterative scheme based on the secant method to obtain the solution of the system of equations. A detailed study of the convergence of the method is presented. The results show excellent convergence of the iterative scheme. Additionally, it is shown that the convergence of the iterative method is affected by neither the number of quadrature points N nor the number of harmonics M included in the solution. However, it is affected by the initial conditions, size of the perturbation 5 applied to compute the Jacobian, and the incorporation of a damping factor r\ in the secant method. Introduction The harmonic balance method is used to obtain analytical solutions for systems of equations with periodic coefficients. A matrix formulation to generalize this technique was developed for the analysis of systems having many coupled degrees of freedom. w Recently, the numerical harmonic balance method has increased in popularity and has been used more frequently to obtain simultaneously the helicopter trim and equilibrium solution/** Yet, there has been no detailed analysis of the numerical effectiveness of a completely numerical harmonic balance, nor of the effect that the variables involved in its application have on the solution of nonlinear systems with periodic coefficients. Also, the flap-lag equations of motion for a rigid blade rotor, presented in previous publications, consider the rotor speed as known and constant; and as a consequence, the azimuth position of any blade as it rotates is always known as a function of time. The purpose of the work presented here is to: 1) derive the nonlinear flap-lag equation of motion for a system of a Q rigid bladed rotor with engine dynamics included; 2) since the rotor speed can be unknown, develop a new harmonic balance method able to overcome the problems presented in the traditional approach when the rotor speed is unsteady, unknown, or both, and apply this technique to solve the flap-lag equations previously derived; and 3) analyze the numerical efficiency of this method to facilitate its implementation in future works. Description of the System The physical system and the coordinates used in deriving the flap-lag equations are shown in Figure 1. The physical system consists of Q equally-spaced identical slender rigid blades, hinged at the center of rotation, with spring restraint at the hinge. A lead-lag