cssi/SciSciGPT-SciSciNet huggingface dataset:
Transport and Meissner Effect Studies for YBa2(Cuy1−xZnx)3O7

Single phase orthorhombic YBa 2 (Cuy 1−x Zn x ) 3 O 7 samples were formed for 0 X for x=6 (T =90 K) is rapidly depressed with increasing x, and is quenched for x>0.08. Low field ( 0.10 semiconducting behavior. The electrical resistance was studied at high quasihydrostatic pressures also, and for x=0.08 showed that T is depressed with increasing pressure: T → 0 K for P >10 GPa. This is in°contrast to YBa 2 (Cuy 1−x Zn x ) 3 O 7 where dT /dP>0. The data support evidence for the high sensitivity to chemical and ice perturbations of the physical properties of samples near the superconducting-normal transition region.
Diversification Times and Biogeographic Patterns in Apiales

This study provides an overview of the historical biogeography of the major clades of Apiales based on extensive taxon sampling from all major lineages of the order, and character sampling of sequence data from the plastid rpl16 intron and trnD-trnY-trnE-trnT intergenic spacers. Divergence times were estimated in BEAST using relaxed molecular clocks and six calibration points from three families. Biogeographic reconstructions were estimated in DIVA and Lagrange using stratified and non-stratified models, addressing alternative scenarios for taxa with conflicting or poorly supported placements. Our analyses in BEAST estimated the origin of Apiales to Australasia in the Early Cretaceous (c.117 Ma). Most major clades also appear to have originated in Australasia, with the youngest family (Apiaceae) originating in the Late Cretaceous, c. 87 Ma. Diversification of the early lineages appears to be influenced by vicariance events related to the break up of Africa and Australasia (Torricelliaceae from Griseliniaceae and Apiineae), Australasia from Zealandia (e.g., Myodocarpaceae and Araliaceae), and Antarctica from South America, Australia, and possibly Africa (main lineages of Apiaceae). Long-distance dispersal appears as the likely explanation for many younger lineages within major clades, including Subantarctic pathways (e.g., Griseliniaceae and Azorelloideae), across the Pacific and Indian Ocean Basins (e.g., Pittosporaceae and Araliaceae), from Asia across Europe into the Americas (Araliaceae).
Fluctuation driven first-order phase transition, below four dimensions, in the random-field Ising model with a Gaussian random-field distribution.

Analysis of the high-temperature susceptibility series for the random-field Ising model with a Gaussian distribution of random fields demonstrates the existence of a fluctuation-driven first-order transition below four dimensions, $dl4$. This, and the behavior of the susceptibility exponent in three dimensions, suggest that $d=4$ is a "critical" dimension for the model.
The Effect of Calfhood Diseases on Growth of Female Dairy Calves During the First 3 Months of Life in New York State

Our objective was to study the effects of pneumonia (cumulative incidence, 25%), diarrhea (29%), umbilical infection (14%), and umbilical hernia (15%) on BW and height gains during the first 3 mo of life. Female dairy calves (n = 410) born from January to December 1990 in 18 commercial herds in New York state were used. Average daily gains during the 1st, 2nd, and 3rd mo were 374, 596, and 719 g, respectively; average gain was 565 g during the 3-mo period. Average monthly height gains during the 1st, 2nd, and 3rd mo were 4.4, 5.6, and 5.7 cm, respectively. Use of multiple linear regression, with farms treated as random effects, indicated that treated, verified pneumonia was associated with a reduction in average daily gain of 66 g and that failure of passive transfer reduced average daily gain by 48 g during the 1st mo. During the 2nd mo, neither disease nor failure of passive transfer affected average daily gain. During the 3rd mo, each additional week of pneumonia reduced average daily gain by 14 g, and umbilical infection reduced average daily gain by 96 g. Each additional week of diagnosed pneumonia reduced total BW gain during the first 3 mo by 0.8 kg. Similarly, each week of pneumonia reduced total height gain by 0.2 cm and failure of passive transfer by 0.9 cm. Prevention of chronic pneumonia and umbilical infection may improve average daily gain of calves.
Tradeoffs in Honeycomb Cored Designs

THE design engineer's objective is to create the best solution to a given set of requirements. In addition to meeting load requirements, there are numerous other demands that must be addressed including weight, cost, corrosion resistance, temperature and moisture performance, fatigue, impact resistance and damage tolerance, etc. This article will illustrate the type of design tradeoffs that are encountered when cored construction is evaluated. Two studies will be outlined. The first will deal with the design of a simple part, and will demonstrate the steps of such a design study while highlighting the strengths of cored structures. The second study will be a summary of the actual preliminary design of an entire aircraft component, and will show how cored structures compare with other designs in a more realistic situation. Of course, the conclusions from one design study are not applicable to another situation with different requirements; a new tradeoff study is needed whenever any design requirement changes.
Materials engineering for tandem mirror reactors

Abstract Recent success in tandem mirror physics experiments has led to several conceptual reactor designs. These studies reveal that there are at least 4 areas in which unique materials problems appear for mirror reactors. The necessity to produce very high magnetic fields (20–24 T) requires the design, construction, and operation of normal copper coils in the intense radiation field of the plasma. A recent proposal to use rapidly changing (50–500 kHz) magnetic fields to reduce the ion density in the transition region has also required Cu coils in the vicinity of the plasma. A third new area is the collection of ion and electron energy and conversion of that energy into useful power. The direct convertor region of tandem mirrors requires the successful operation of very high heat flux components (200–300 W/cm 2 ). Finally, the heating of electrons as well as plasma startup scenarios dictate the extensive use of RF power. The most severe problems seem to be associated with the placement of ICRF antennas at the edge of the plasma and in the vicinity of high neutron wall loadings (1–4 MW/m 2 ). These problems are discussed in light of the recent MARS reactor study.
Categories of Resistance to Greenbug and Yellow Sugarcane Aphid (Hemiptera: Aphididae) in Three Tetraploid Switchgrass Populations

Switchgrass, Panicum virgatum L., has been targeted as a bioenergy feedstock. However, little is currently known of the mechanisms of insect resistance in this species. Here, two no-choice studies were performed to determine the categories (antibiosis and tolerance) and relative levels of resistance of three switchgrass populations (Kanlow–lowland ecotype, Summer–upland ecotype, and third generation derivatives between Kanlow × Summer plants, K×S) previously identified with differential levels of resistance to the greenbug, Schizaphis graminum (Rondani), and yellow sugarcane aphid, Sipha flava (Forbes). No-choice studies indicated that Kanlow possessed multi-species resistance, with high levels of antibiosis to both aphid species, based on aphid survival at 7 and 14 days after aphid introduction and cumulative aphid days, while K×S possessed low-to-moderate levels of antibiosis to S. flava. Further, functional plant loss indices based on plant height and biomass indicated that tolerance is an important category of resistance for Summer plants to S. graminum. These studies also indicated that Summer lacks both tolerance and antibiosis to S. flava, relative to the other switchgrasses tested, whereas K×S lack tolerance and antibiosis to S. graminum. These studies are the first attempt to analyze the categories of resistance in switchgrass and provide critical information for characterizing the biological mechanisms of resistance and improving our knowledge of the plant–insect interactions within this system.
The Relationship Between Workplace E-Mail Privacy and Psychological Contract Violation, and Their Influence on Trust in Top Management and Affective Commitment

This study used communication privacy management and psychological contract (PC) theory to see if employee concerns about e-mail privacy would influence their feelings of PC violation and trust in top management. In addition, this study examined the impact of perceived PC violations on employees' feelings of trust in top management and affective organizational commitment. A total of 251 participants filled out a Web questionnaire. Results were consistent with the theoretical perspective, as feelings of e-mail privacy were linked to perceived PC violations and trust in top management. These perceptions, in turn, were related to employees' feelings of affective commitment.
Predicting discharge dynamics from a rectangular hopper using the discrete element method (DEM)

Accurate prediction of the discharge rate from hoppers is important in many industrial processes involving the handling of granular materials. The present work investigates the parameters affecting the discharge rate using the discrete element method (DEM). The effects of particle properties (particle size and size distribution) and hopper geometry (hopper width, outlet width, angle and fill height) are studied and compared to previously published experimental correlations. The results indicate that DEM simulations are fully capable of reproducing trends in the discharge rate that are well-known experimentally. For example, particle size and hopper width are shown to have a minimal influence on the discharge rate. In addition, for rectangular hoppers, the discharge rate is shown to vary with the outlet width raised to the 32 power as given by the modified Beverloo correlation. The DEM simulations are also used to explore a wider range of parameters that have not been or are not easily explored experimentally. For example, the effects of hopper friction, particle friction, coefficient of restitution are investigated, and particle friction is shown to have a significant influence on the hopper discharge behavior.
Leaf-Associated Bacterial and Fungal Taxa Shifts in Response to Larvae of the Tree Hole Mosquito, Ochlerotatus triseriatus

Larvae of the eastern tree hole mosquito, Ochlerotatus triseriatus (Say), and related container-breeding species are known to feed upon substrate-associated microorganisms. Although the importance of these microbial resources to larval growth has been established, almost nothing is known about the taxonomic composition and dynamics of these critical microbial food sources. We examined bacterial and fungal community compositional changes on oak leaves tethered in natural tree hole habitats of O. triseriatus. We eliminated larvae experimentally in a subset of the tree holes and examined 16S rDNA gene sequences for bacteria and ergosterol concentrations and 18S rRNA gene sequences for fungi collected from leaf material subsamples. Leaf ergosterol content varied significantly with time, but not treatment. Principal component analysis (PCA) was used to compare microbial taxonomic patterns found in leaves incubated with or without larvae present, and we found that larval presence affected both bacterial and fungal groups, either from loosely attached or strongly adherent categories. Bacterial communities generally grouped more tightly when larvae were present, and class level taxa proportions changed when larvae were present, suggesting selection by larval feeding or activities for particular taxa such as members of the Bacteroidetes, Alphaproteobacteria, and Betaproteobacteria classes. Fungal taxa composite scores also separated along PC axes related to the presence of larvae and indicated larval feeding effects on several higher taxonomic groups, including Saccharomycetes, Dothideomycetes, and Chytridiomycota. These results support the hypothesis that larval mosquito feeding and activities altered microbial communities associated with substrate surfaces, potentially leading to decreased food value of the resource and affecting decomposition of particulate matter in the system.
Tetramethoxy Calix[4]arenes Revisited: Conformational Control through Self-Assembly

The concept of preorganization in molecular assembly has been well established, and its impact on synthetic supramolecular chemistry is profound.1 Many natural systems thrive on the ability of inherently flexible molecules to self-organize. This process is promoted by a well-defined surrounding architecture and culminates in self-assembly.2 The ability of a protein to find its thermodynamically most stable tertiary structure from a linear sequence of amino acids is an example. Also related is the ability of two flexible, complementary polynucleotide strands to form a double helix. In this paper we demonstrate how flexible molecules can reversibly self-assemble to give a well-defined receptor caVity. The calix[4]arene skeleton3 was chosen as a vehicle for modeling such phenomena. The calixarene platform has recently been exploited for assembly by several laboratories.4,5 Research in our group has explored a unique dimeric binding mode for the calix[4]arene framework which provides for the encapsulation of small molecule guests.5,6 Specifically, urea functions placed on the upper rim of the calix[4]arene permit dimerization to occur through a head-to-tail hydrogen bonding pattern (Figure 1). It is well-known that the calix[4]arenes interconvert between four discrete conformations in solution.3,7 This conformational flexibility can be controlled by alkylation of the phenolic oxygens with substituents larger than ethyl, i.e. reaction of the parent phenol with n-PrBr to give the tetrapropoxy derivative allows the isolation of three stable conformations: the cone (42%), partial cone (55%), and 1,3-alternate (3%).7b We have recently explored derivative 1-1, which uses benzyl ether substituents for such control. In calixarene derivative 1-2 much smaller lower rim substituents are present. The tetramethoxy calix[4]arene has been wellstudied and is defined as a “flexible” system.7,8 It freely interconverts between all four conformations, but the partial cone is the thermodynamically most favorable one.8 Specifically, in the parent tert-butyl system the difference in energy between the partial cone/cone isomers is ∼1.5 kcal/mol, and the barrier to interconversion is on the order of 13 kcal.8c We have found that intermolecular hydrogen bonding through dimerization can be used to driVe the conformational equilibrium exclusiVely to the cone conformer. Since substitution on the upper rim of the calixarene is not known to substantially bias the conformational equilibria,3 the observed conformational selection (self-organization) can be attributed solely to hydrogen bonding effects.
Percutaneous infraclavicular subclavian vein catheterization in critically ill infants and children

The safety and risks of percutaneous infraclavicular subclavian vein catheterization, when performed by nonsurgical staff, were studied prospectively in 100 consecutive patients. The overall success rate was 92% (with one attempt, 45%; with two attempts, 85%). The procedure was performed under emergency conditions in 35% of the patients, with a success rate of 88.6%. The success rate was significantly lower in younger patients. Hemodynamic status, respiratory status, and level of expertise of the individual performing catheterization did not affect success rate. Most of the fallures (six of eight) were related to presumed thrombosis from prior cannulation of the superior vena cava. Mean duration of catheterization was 7.5±5.8 days (±SD). Minor complications (n=24) included hematomas, minor bleeding from subclavian artery puncture, and transient premature ventricular ectopic beats. Major complications (n=6) were pneumothoraces (n=4) and catheter-related infection (n=2). The number of attempts made to catheterize the vessel and the level of expertise of the operator had the greatest effect on complication rates. No mortality was associated with this procedure. We have found percutaneous infraclavicular subclavian vein catheterization to be a rapid alternative to surgical cutdown for venous access during cardiopulmonary resuscitation. Pediatric residents can be trained, under direct supervision, to perform this procedure with a high success rate and a low complication rate.
Fatigue Strength of Steel Girders Strengthened with Carbon Fiber Reinforced Polymer Patch

Fatigue sensitive details in aging steel girders is one of the common problems that structural engineers are facing today. The design characteristics of steel members can be enhanced significantly by epoxy bonding carbon fiber reinforced polymers~CFRP! laminates to the critically stressed tension areas. This paper presents the results of a study on the retrofitting of notched steel beams with CFRP patches for medium cycle fatigue loading (R50.1). A total of 21 specimens made of S12734.5 A36 steel beams were prepared and tested. Unretrofitted beams were also tested as control specimens. The steel beams were tested under four point bending with the loading rate of between 5 and 10 Hz. Different constant stress ranges between 69 and 379 MPa were considered. The length and thickness of the patch were kept the same for all the retrofitted specimens. In addition to the number of cycles to failure, changes in the stiffness and crack initiation and growth were monitored during each experiment. The results showed that the CFRP patch not only tends to extend the fatigue life of a detail more than three times, but also decreases the crack growth rate significantly.
Tracking serial costs with computer technology

After offering a summary of causes of and responses to the crisis in serials costs, this article describes ways of using computer technology to track prices and project costs. Data may be developed through the use of serial check-in systems, local reports, and vendor price reports. Computers can also be used to initiate consumer action and provide access to articles for document delivery. Both publishers and vendors are cooperating with these efforts.
Decentralized Estimation using distortion sensitive learning vector quantization

A typical approach in supervised learning when data comes from multiple sources is to send original data from all sources to a central location and train a predictor that estimates a certain target quantity. This can be inefficient and costly in applications with constrained communication channels, due to limited power and/or bitlength constraints. Under such constraints, one potential solution is to send encoded data from sources and use a decoder at the central location. Data at each source is summarized into a single codeword and sent to a central location, where a target quantity is estimated using received codewords. This problem is known as Decentralized Estimation. In this paper we propose a variant of the Learning Vector Quantization (LVQ) classification algorithm, the Distortion Sensitive LVQ (DSLVQ), to be used for encoder design in decentralized estimation. Unlike most related research that assumes known distributions of source observations, we assume that only a set of empirical samples is available. DSLVQ approach is compared to previously proposed Regression Tree and Deterministic Annealing (DA) approaches for encoder design in the same setting. While Regression Tree is very fast to train, it is limited to encoder regions with axis-parallel splits. On the other hand, DA is known to provide state-of-the-art performance. However, its training complexity grows with the number of sources that have different data distributions, due to over-parametrization. Our experiments on several synthetic and one real-world remote sensing problem show that DA has limited application potential as it is highly impractical to train even in a four-source setting, while DSLVQ is as simple and fast to train as the Regression Tree. In addition, DSLVQ shows similar performance to DA in experiments with small number of sources and outperforms DA in experiments with large number of sources, while consistently outperforming the Regression Tree algorithm.
Sensitivity of Dielectric Properties to Wear Process on Carbon Nanofiber/High-Density Polyethylene Composites

We examined the correlation of wear effects with dielectric properties of carbon nanofibers (CNFs; untreated and organosilane-treated)-reinforced high-density polyethylene (HDPE) composites. Wear testing for the nanocomposites over up to 120 h was carried out, and then, dielectric permittivity and dielectric loss factor of the polymer composites with the increased wear time were studied. Scanning electron microscope and optical microscope observations were made to analyze the microstructure features of the nanocomposites. The results reveal that there exist approximate linear relationships of permittivity with wear coefficient for the nanocomposites. Composites containing silanized CNFs with the sufficiently thick coating exhibited high wear resistance. The change in permittivity was more sensitive to the increased wear coefficient for the nanocomposites with lower wear resistance. This work provides potential for further research on the application of dielectric signals to detect the effects of wear process on lifetime of polymeric materials.
Teaching Andrology in U.S. and Canadian Medical Schools: A Questionnaire

Based on the questionnaires answered by 60 of the 140 schools surveyed, it is apparent that the teaching of andrology receives little emphasis in the schools' curricula. The lack of support given to the teaching of andrology is more evident at the postgraduate than at the undergraduate level. Although andrology is relatively new as an independent biochemical specialty, it is suggested that increased availability of information on andrology to students and physicians would have a positive impact on the quality of health care.
Effect of background components on spatial-frequency masking

Previous studies of spatial-frequency masking and adaptation have shown that the contrast-detection threshold elevates maximally when the test spatial frequency is the same as the masking (or adapting) frequency but changes only slightly when they are separated by two or more octaves. At low spatial frequencies, however, the peak of the threshold-elevation function does not obey this rule: there is a well-established peak shift in the threshold-elevation functions toward higher spatial frequencies. We investigated whether this shift might be due to the masking effects caused by the background field, which contributes energy at the very low end of the spectrum. We first measured the effect of a 3-cycles/deg (c/deg) mask on detection of a range of test frequencies, compared with unmasked detection thresholds. We then measured the combined effect of a 2-c/deg and a 3-c/deg mask on detection, compared with detection with just the 2-c/deg mask. The comparison in the second case still tests the effect of the 3-c/deg mask, but the presence of the hidden 2-c/deg mask causes the peak masking effect to shift toward higher frequencies. This result provides a proof of concept for the hypothesis that the peak shift at low spatial frequencies is caused by the low-frequency energy in the background field, which is present in both masked and unmasked conditions. A five-parameter quantitative model of frequency masking is presented that describes the pure contrast-detection function, the frequency-masking functions at mask frequencies of 0.25, 0.5, 2, and 3 c/deg, and the peak-shift phenomenon.
Effects of islet grafts of MHC-compatible donors on glucose metabolism in the spontaneously diabetic BB/Wor rat

Summary Complete recovery of the diabetic process occurred in spontaneously diabetic BB/Wor rats after the transplantation of islets of MHC-compatible donor rats. Islets were isolated from diabetes-resistant BB/Wor rats and were cultured for 4 days at 37°C. The islets were then hand-picked and each BB/Wor rat with spontaneous diabetes received a total of 10 islets per g of body weight injected either into the immunologically privileged abdominal testis or into the non-immunologically favored renal subcapsular space. No immunosuppression was given to the recipients. After a period of at least 80 days of normoglycemia, the effects of an intravenous glucose injection on serum glucose and insulin levels were assessed. The grafts and the pancreases were then surgically removed and the insulin content of each organ site determined. The results showed that normogly-cemia and a rapid weight gain were induced whether the rats were given an intratesticular or a renal, subcapsular islet graft. The amounts of extracted insulin recovered from the grafts after 83-259 days of normoglycemia were not significantly different from the pancreatic insulin content of age-matched control rats. But, despite the survival of a large mass of insulin-producing cells, glucose tolerance was impaired with a blunted insulin response and a delayed return of serum glucose to basal levels. Histologic examination of the islet grafts between 214 and 269 days after transplantation showed remarkable preservation of the islets with no evidence of an inflammatory reaction. Successful transplantation did not, however, lead to a recovery of the native pancreas of the BB/Wor recipient. In conclusion, these results suggest that the MHC-compatible grafted BB/Wor rat may provide a very useful animal model for the study of the pathophysiology and the amelioration of the complications associated with type 1 diabetes mellitus.
Large-scale association analysis provides insights into the genetic architecture and pathophysiology of type 2 diabetes mellitus.

We are amidst an epidemic of cardiometabolic diseases. Despite aggressive lifestyle modifications, the incidence of type 2 diabetes mellitus (T2DM), a potent risk factor for cardiovascular diseases, continues to rise. Simple family histories in patients demonstrate that there is a clustering of the disease in families, and prior studies using genome-wide association (GWA) approaches have identified 56 genetic loci that are associated with T2DM. In a recently published herculean effort, the authors stated that prior GWA study results captured 10% of familial aggregation of the disease. Therefore, to extend understanding of the genetic architecture and molecular basis of T2DM, the authors conducted a meta-analysis (34 840 cases and 114 981 controls) of genetic variants on the Metabochip, a custom array of 196 725 variants designed to facilitate cost-effective follow-up of nominal associations for T2DM, and other metabolic and cardiovascular traits and to enhance fine mapping of established loci. The authors asked whether characterization of increasing numbers of risk loci may provide evidence, at the functional level, that susceptibility to T2DM involves a limited set of molecular processes. The authors conducted a 2-stage meta-analysis: stage-1 meta-analysis consisted of 12 171 T2DM cases and 56 862 controls across 12 GWA studies of individuals of European descent, and the stage-2 meta-analysis consisted of 21 491 T2DM cases and 55 647 controls across 25 studies of individuals of European descent, and 1178 T2DM cases and 2472 controls from 1 study of individuals of Pakistani descent (PROMIS). These participants all underwent genotyping on the Metabochip, in which the T2DM component was comprised of 21 774 variants: 5057 replication single-nucleotide polymorphisms (SNPs) that capture the strongest independent 13 autosomal association signals from the GWA meta-analysis conducted by the Diabetes Genetics Replication and Meta-analysis (DIAGRAM) Consortium, and an additional 16 717 variants chosen from 1000 Genomes Project …
X-RAY CRYSTAL STRUCTURE OF 6,17-DIMETHYL-8, 15-DIPHENYL-DIBENZO [b,i][1,4,8,11]TETRAAZACYCLOTETRADECINATO COPPER(II): THE MORE STERICALLY-CROWDED ISOMER

Abstract 6,17-Dimethyl-8,15-diphenyldibenzo[b,i][1,4,8,11]tetraazacyclotetradecinato copper(II), [Cu(cis-Me2Ph2Bzo2[14]tetraeneN4)], was prepared by the reaction of the metal-free macrocycle with copper acetate. The compound crystallizes in the monoclinic space group P21/c with two crystallographically independent molecules in the asymmetric unit and lattice parameters a = 11.059(2)A, b, = 19.164(5)A, c = 24.007(7)A, β = 93.16°, V = 5080 A3. Convergence to R = 0.040 and R w = 0.056 was obtained based on 5319 unique reflections with I > 3σ(I).
The specificity of collagen cross-links as markers of bone and connective tissue degradation

The availability of a specific and convenient biochemical assay for quantifying bone turnover would aid in the clinical management of osteoporosis and other metabolic bone diseases. Recently, several immunoassays for bone metabolites have been reported in the research literature, with data suggesting that certain of them may now have the required specificity and responsiveness to bone cell activity and convenience for routine clinical use. Biochemical assays for monitoring bone metabolism usually target enzymes or other proteins synthesized by osteoblasts or osteoclasts that can be found in serum, or degradation products of the organic fabric of the resorbed bone that are excreted in urine (1,2). The most convincing current markers of bone formation are serum levels of skeletal alkaline phosphatase and osteocalcin. These markers usually show a lag period of several months in responding to natural and therapeutically induced changes in bone turnover rate (3), consistent with the concept that formation is coupled to but lags behind resorption at remodeling sites. Most bone resorption markers, in contrast, rely on the measurement of metabolites of collagen generated by osteoclasts in the process of degrading bone. Urinary hydroxyproline is a traditional indicator, but newer and more convenient immunoassays have focused on collagen cross-linking metabolites which offer greater specificity to bone collagen than hydroxyproline.
Performance of optical networks

We will review and compare the most common wavelength-division multiplexing (WDM) optical network architectures and present conclusions on the potential roles of these architectures for various applications, e.g., LANs, MANs, WANs, access, enterprise, and carrier networks. We cover broadcast stars, passive wavelength-routed networks, and configurable wavelength-routed networks, which use wavelength-selective switches. The emphasis is on the network performance, e.g., blocking probabilities, circuit-carrying capacity, etc., of these architectures and on device/network performance trade-offs. Of particular interest is the potential usefulness of wavelength changers to increase capacity. Other issues in the wavelength changer debate are also discussed, such as routing complexity, reliability and network-network interfacing. We survey previous results on these topics and discuss what open questions remain.
Antibiotic-Inducible Promoter Regulated by the Cell Envelope Stress-Sensing Two-Component System LiaRS of Bacillus subtilis

Soil bacteria are among the most prodigious producers of antibiotics. The Bacillus subtilis LiaRS (formerly YvqCE) two-component system is one of several antibiotic-sensing systems that coordinate the genetic response to cell wall-active antibiotics. Upon the addition of vancomycin or bacitracin, LiaRS autoregulates the liaIHGFSR operon. We have characterized the promoter of the lia operon and defined the cis -acting sequences necessary for antibiotic-inducible gene expression. A survey for compounds that act as inducers of the lia promoter revealed that it responds strongly to a subset of cell wall-active antibiotics that interfere with the lipid II cycle in the cytoplasmic membrane (bacitracin, nisin, ramoplanin, and vancomycin). Chemicals that perturb the cytoplasmic membrane, such as organic solvents, are also weak inducers. Thus, the reporter derived from P liaI (the liaI promoter) provides a tool for the detection and classification of antimicrobial compounds.
Variation in Cataract Surgery Practice and Clinical Outcomes

Purpose: To examine associations between surgical technique, patient and surgeon characteristics, and clinical outcomes of cataract surgery. Methods: Seventy-five ophthalmologists were recruited from three cities based on a sampling scheme stratified by surgeon-reported annual volume of cataract surgery. Seven hundred seventy-two patients undergoing first eye cataract surgery were enrolled, with complete preoperative, perioperative, and 4-month postoperative clinical data on 717 patients (93%). Results: Sixty-five percent of surgery was performed by phacoemulsification and 35% by standard extracapsular (ECCE) techniques. Performance of ECCE was associated with the presence of ocular comorbidity and 21 or more years in practice of the surgeon. Performance of phacoemulsification was associated with annual volume of cataract surgery, wherein high-volume (201–399 patients annually) and very high-volume (>400 patients annually) surgeons had 3.7 and 3.9 times the likelihood of performing phacoemulsification compared with moderate-volume (51–200 cases annually) surgeons. The rates of intraoperative, perioperative, and 4-month postoperative adverse events and the amount of improvement in visual acuity did not differ either by surgical technique or volume stratum. The reported occurrence of posterior capsular opacification within 4 months of surgery was increased in the presence of cortical opacification, one city, and patients operated on by either high- or very high-volume surgeons. Conclusions: In this cohort, no difference in clinical outcomes, as measured by change in visual acuity or occurrence of postoperative adverse events (except for posterior capsular opacification), can be attributed to performance of phacoemulsification versus ECCE or to the reported annual volume of cataract surgery of the surgeon. Selfreported high and very high annual volume of cataract surgery is associated independently with performance of phacoemulsification and surgeon's report of posterior capsular opacification at 4 months after cataract surgery.
A Defective Signal Peptide Tethers the floury-2 Zein to the Endoplasmic Reticulum Membrane

The maize (Zea mays L.) floury-2 (fl2) mutation is associated with a general decrease in storage protein synthesis, altered protein body morphology, and the synthesis of a novel 24-kD [alpha]-zein storage protein. Unlike storage proteins in normal kernels and the majority of storage proteins in fl2 kernels, the 24-kD [alpha]-zein contains a signal peptide that would normally be removed during protein synthesis and processing. The expected processing site of this [alpha]-zein reveals a putative mutation alaine->valine (Ala->Val) that is not found at other junctions between signal sequences and mature proteins. To investigate the impact of such a mutation on signal peptide cleavage, we have assayed the 24-kD fl2 [alpha]-zein in a co-translational processing system in vitro. Translation of RNA from fl2 kernels or synthetic RNA encoding the fl2 [alpha]-zein in the presence of microsomes yielded a 24-kD polypeptide. A normal signal peptide sequence, generated by site-directed mutagenesis, restored the capacity of the RNA to direct synthesis of a properly processed protein in a cell-free system. Both the fl2 [alpha]-zein and the fl2 [alpha]-zein (Val->Ala) were translocated into the lumen of the endoplasmic reticulum. The processed fl2 [alpha]-zein (Val->Ala) was localized in the soluble portion of the microsomes, whereas the fl2 [alpha]-zein co-fractionated with the microsomal membranes. By remaining anchored to protein body membranes during endosperm maturation, the fl2 zein may thus constrain storage protein packing and perturb protein body morphology.
Modeling scientific evidence: the challenge of specifying likelihoods

One aim of confirmation theory is to represent the objective character of scientific evidence. Here I explore two challenges that must be overcome by probabilistic models of confirmation in order to succeed in this aim: the foundation challenge and the specification challenge. I discuss Sober’s recent approach to confirmation and his response to these challenges. I argue that while Sober makes real progress, neither challenge is completely overcome. The specification challenge is particularly difficult, undermining the general argument that the law of likelihood provides a more objective model of confirmation.
Nonparametric density estimation for classes of positive random variables

A kernel-based density estimator for positive random variables is proposed and analyzed. In particular, a nonparametric estimator is developed which takes advantage of the fact that positive random variables can be represented as the norms of random vectors. By appropriately choosing the dimension of the assumed vector space, the estimator can be structured to exploit a priori knowledge about the density to be estimated. The asymptotic properties (e.g., pointwise and L/sub 1/-consistency) of this density estimator are investigated and found to be similar to the desirable features of the standard kernel estimator. An upper bound on the expected value of the L/sub 1/ error is also derived which provides insight into the behavior of the estimator. Upon using this upper bound, the optimal form for the estimator (i.e., the kernel function, the smoothing factor, etc.) is selected via a minimax strategy. In addition, this upper bound is used to compare the asymptotic performance of the proposed estimator to that of the standard kernel estimator and to boundary-corrected kernel estimators. Numerical examples illustrate that the proposed scheme outperforms the standard and boundary-corrected estimators for a variety of density types. >
Unstable waves on an axisymmetric jet column

The growth of infinitesimal disturbances on an axisymmetric jet column is investigated theoretically and experimentally. The theoretical analysis is based upon inviscid stability theory, wherein axisymmetric, helical and double helical disturbances are considered from the spatial reference frame. In the jet flow field near the source, the mean velocity profile is observed to have a potential core and a thin, but finite, shear layer between the potential core and the quiescent ambient fluid. With downstream distance, the potential core diameter decreases and the shear-layer thickness increases. To incorporate these variations into the theory, a quasi-uniform assumption is adopted, whereby successive velocity profiles are analysed individually throughout the region in the jet flow where disturbances are observed to be small. The results of the theory indicate that initially, in the jet flow where the shear layer is thin and the potential core is larger, all disturbances considered are unstable. The dominant disturbance in the jet is an axisymmetric one. However, further downstream in the jet, where the half-breadth thickness of the shear layer is 55% of the potential core radius, a helical disturbance is found to dominate the axisymmetric and double helical modes. Nowhere in the jet flow field examined was the double helical disturbance found to be dominant. The cross-stream distributions of velocity and vorticity for the dominant disturbance modes are presented according to the spatial stability theory.The downstream development of the jet column and the characteristics of the disturbances amplifying on it were also studied in a water tank. No artificial stimulation of any particular disturbance was used. The experimental results show good agreement with the results of the theory in the region where the disturbances are small. However, conclusive confirmation of the switch in the hierarchy of dominant disturbances was not found. Half of the time the disturbance observed experimentally exhibits an axisymmetric character and the other half a helical one. This apparently is due to the similar spatial amplification rates experienced by both of these disturbance modes. It is concluded that this switching of dominant modes is, in large part, responsible for (i) the well-known natural drifting of disturbance characteristics in jet flows, and (ii) the wide variety of observations made in previous jet experiments.
HIGH RATES OF PRIMARY PRODUCTIVITY IN A SEMI‐ARID TAILWATER: IMPLICATIONS FOR SELF‐REGULATED PRODUCTION

Reservoir-river systems in desert environments may provide the optimal combination of environmental conditions (e.g. light, nutrients, temperature, and flow) that maximizes primary production in downstream reaches. Stream metabolism was measured using an open-system approach each month during spring-summer in a semi-arid tailwater (South Fork Humboldt River) in the central Great Basin, USA. Spatial and temporal differences in metabolic rates were evident despite tailwater reaches sustaining comparable standing stocks of periphyton (>10 µg chla cm−2) during this growing season. Primary productivity was highest (15 to 36 g O2 m−2 day−1) in July, supporting previous studies that have described arid regulated/unregulated streams as ultra-productive. Substrate availability when combined with self-shading and hypoxic conditions created a system that was likely near the maximal productivity that stream systems can achieve because of the self-regulating attributes that thick periphyton mats impose upon themselves as they reach high biomass and maximal production rates. Copyright © 2011 John Wiley & Sons, Ltd.
Planar fault energies and dislocation core spreading in B2 NiAl

We present computer simulation results for the planar faults involved in core spreading of 〈100〉 and 〈111〉 dislocations. Seven γ surfaces were computed for different crystallographic planes ({110}, {112}, {123}, {210}, {100}, {111}, and {122}). Stable APB’s are observed in the {110} and {112} planes, but they are deviated from the exact 1/2a〈111〉 position. No other stable planar fault was observed. The fact that a stable minimum is observed deviated from the 1/2〈111〉 position suggests the possibility of different dissociation reactions for the 〈111〉 screw dislocation in the {110} and {112} planes. The fact that no other stable minima were observed in the γ surfaces indicates that no true core dissociation is expected for the 〈100〉 dislocations. We propose that dislocation core spreading in various planes can be understood in terms of the directions of lowest restoring forces observed for the corresponding γ surfaces.
Removing the Stress from Selecting Instruments: Arming Social Workers to Take Leadership in Routine Distress Screening Implementation

Quality cancer care requires identifying and addressing the psychosocial needs of cancer patients. Oncology social workers have long been on the forefront of this endeavor. Although there has been longstanding interest in screening cancer patients for distress, it has recently been included as a quality of care metric in institutions accredited by the American College of Surgeons. Implementing routine screening for distress in oncology settings requires thoughtful planning, including assessing various screening instruments and considering a host of variables within each practice setting. Oncology social workers are best positioned to provide leadership in operationalizing this mandate and to lead their team in the choice of a distress measure for compliance with the screening guideline. This article highlights the most popular distress screening measures used in oncology and their psychometric properties.
Implications of alternative environmental policies on phosphorus loading from poultry litter

Abstract Degraded groundwater, impaired swimming, fishing, algae and weed problem are often associated with eutrophication from phosphorus (P) loadings in surface and groundwater. The concentrated growth of poultry industry and over application of litter on pasture lands may lead to excessive nutrient loadings in surface and groundwater. The Cooperative Extension Service recommendation suggests that no poultry litter should be applied if the soil test P exceeds 300 pounds per acre, irrespective of the marginal costs and benefits associated with one more unit of litter application on that piece of land. The objective of this paper is to model the economics of P loadings from poultry litter and analyze the policy implications of Cooperative Extension Service's recommendation on quantity restriction on litter applications with empirical evidence. The results indicate that there exists significant difference in the marginal values of soil between different soil series, indicating that the permit system can achieve the target at a lesser cost. In particular, the society as a whole can gain $2.7 per acre by allocating the litter to soil series 16 instead of soil series 20, provided that the contribution towards groundwater contamination from these two acres are the same.
Hedging and Speculative Trading in Agricultural Futures Markets

Regulators and industry participants have expressed concern that excessive speculation harms agricultural futures markets. Such harm may arise if speculators cause prices to systematically differ from the price sequence that would arise in markets populated by equally informed traders with rational expectations (RE). We show theoretically that, when traders exhibit differences of opinion (DO) about the expected value of the commodity, futures prices may diverge from the RE equilibrium. Moreover, we develop a testable prediction, namely that positions held by different trader groups are correlated with prices in a DO equilibrium but not correlated in a RE equilibrium. We find strong empirical support for the DO-type environment; changes in positions held by managed money traders are positively correlated with prices, and changes in positions held by producers are negatively correlated. In the context of our DO model, this finding implies that prices change by more on average than producers think they should and by less than managed money thinks they should. However, the evidence suggests that neither group is systematically more prescient than the other.
Unique Architecture of the Plastid Ribosomal RNA Operon Promoter Recognized by the Multisubunit RNA Polymerase in Tobacco and Other Higher Plants

Expression of the plastid rRNA operon (rrn) during development is highly regulated at the level of transcription. The plastid rrn operon in most higher plants is transcribed by the plastid-encoded RNA polymerase (PEP), the multisubunit plastid RNA polymerase from PrrnP1, a σ70-type promoter with conserved −10 and −35 core promoter elements. To identify functionally important sequences, the tobacco PrrnP1 was dissected in vivo and in vitro. Based on in vivo deletion analysis, sequences upstream of nucleotide −83 do not significantly contribute to promoter function. The in vitro analyses identified an essential hexameric sequence upstream of the −35 element (GTGGGA; the rRNA operon upstream activator [RUA]) that is conserved in monocot and dicot species and suggested that the −10 element plays only a limited role in PrrnP1 recognition. Mutations in the initial transcribed sequence (+9 to +14) enhanced transcription, the characteristic of strong promoters in prokaryotes. We propose that σ interaction with the −10 element in PrrnP1 is replaced in part by direct PEP-RUA (protein–DNA) interaction or by protein–protein interaction between the PEP and an RUA binding transcription factor.
Nonlinear codes for dispersive nonlinear fibers

We consider a single wavelength channel in a nonlinear dispersive single-mode fiber. We simulate the propagation of binary sequences using on-off keying return-to-zero modulation at a bit rate of 10 Gb/s, under different dispersion and input power conditions. We determine the impact that dispersion and nonlinearity have on the pulse sequences by measuring the Euclidian distances (EDs) among all pairs of received sequences. We then model the set of EDs as a fully connected graph and by means of a clique-finding algorithm we search for subsets of sequences that form codes matched to this nonlinear channel, resulting in significant bit-error-rate improvement.
Negotiating New Asian American Masculinities: Attitudes and Gender Expectations

Historically, U.S. institutional practices have rendered Asian-American men as simultaneously hypermasculine and emasculated. Today, the model minority myth and asexual media representations have e...