cssi/SciSciGPT-SciSciNet huggingface dataset:
Refinement of Reduced Chemical Mechanisms for the Modeling of the Rapid Compression Combustion of Heptane and Octane

Reduced chemical mechanisms for heptane and octane, originally developed by Keck and Hu, have been shown to give excellent agreement with experimental ignition delay times obtained using a rapid compression machine. These mechanisms consist of 20 species and 41 reactions with 10 reactions detailing the initial breakdown sequence of the alkane, 2 global reactions leading to the formation of end products, and the remaining reactions specifying the path to equilibrium products. Until recently, the success of these mechanisms in matching experimental data rested in large part on the fine tuning of forward rates, and the inclusion of specified reverse rates. For a given reaction, the calculation of the reverse rate from the forward rate and the equilibrium constant—detailed balancing—is the technically correct approach, and the focus of this work was the elimination of the specified reverse rates in favor of this approach. Elimination of the specified reverse rates was found to depend on the accuracy of the thermodynamic property data generated with NASA style polynomial coefficients. Both mechanisms are now able to match experimental data generated with the M.I.T. rapid compression machine with impressive agreement, by employing detailed balancing for the calculation of reverse rates. Current computation techniques include the Detailed and Rate Controlled Constrained Equilibrium methods. However, at the present time, only the detailed method includes the algorithm to model the rapid compression sequence. Work to incorporate the algorithm into the RCCE computation is now underway.Copyright © 2005 by ASME
Formation of Ti/O compositional gradient film on Ti–6Al–4V alloy by reactive DC sputtering

Coating of Ti-6Al-4V alloy substrates with Ti/O compositional gradient films was carried out by reactive DC sputtering, not only to improve the biocompatibility and the surface hardness of the alloy but also to relax the stress concentrated at the interface between the film and the alloy. The compositional gradient was realized by varying continuously the oxygen content in Ar-O 2 sputter gas during depositing. Under AES, it was confirmed that a Ti/O compositional gradient film had formed on the alloy, and it was concluded that the oxygen atoms which had concentrated at the surface of the alloy substrate diffused into the titanium layer in the compositional gradient film. Based on the results of XRD, it was found that α-titanium phase was formed in the compositional gradient film with (002) orientation dominant during the film growth. Furthermore, based on indentation-fracture tests, it was concluded that this depositing method improved the adhesion of the deposited film to the alloy substrate and the toughness of the film.
The hormonal control of migratory flight behaviour in the convergent ladybird beetle, Hippodamia convergens

. Topical application of the juvenile hormone mimic, Altosid, to Hippodamia convergens (Guerin-Meneville) (Coccinellidae) stimulated a significant increase in long-term flight behaviour in both males and females. Altosid treatment also stimulated ovarian development in females. Topical application of precocene II to H.convergens inhibited flight activity in treated animals of both sexes for about 10 days. Altosid treatment to precocene-treated beetles significantly increased their migratory behaviour over that of precocene-treated or acetone-treated controls. These results indicate that juvenile hormone stimulates migratory flight behaviour in this species along with reproductive development. It is likely that the hormone serves to coordinate migration with reproduction in the young adult.
Limits on CP invariance in general relativity

The test of the equivalence principle pointed out by Longo and by Krauss and Tremaine can be easily extended to comparing the infall velocities of matter and antimatter. The very close coincidence in arrival times for neutrinos and antineutrinos places strong constraints on the coupling of gravitational interactions to matter and antimatter. The relative difference in gravitational delay is less than 5\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}6}$.
Enhanced selectivity for capillary zone electrophoresis using ion-pair agents

Abstract Capillary zone electrophoresis (CZE) is unique in its simplicity and versatility for liquid separations, yet selectivity for solutes with similar charge and hydrated radius is often lacking. Conventional reversed-phase liquid chromatography (RP-LC) ion-pairing agents, ionic polymers, Group I and II metal cations and dicarboxylic acids have all been effectively used over the past decade to enhance CZE resolution through a combination of complexing effects. This review summarizes the fundamental theory of ion–ion interaction as applied to CZE separations and discusses several of the most important and diverse applications of selectivity enhancement that utilize ion-pair equilibria. In addition, the effect of ion-pair additives on electroosmotic flow and examples where changes in analyte selectivity are unrelated to ion–ion interaction are discussed.
Creating engaging experiences for rehabilitation.

AbstractThe traditional model of rehabilitation center design based on usability and function falls short of addressing the aspirations of those who use them. To better serve the motivational needs of both patients and therapists, we need to reconsider the gymnasium-inspired designs of current rehabilitation centers. Designers Patricia Moore and David Guynes have drawn inspiration from the everyday to create more engaging rehabilitation experiences with their Easy Street®, Independence Square®, Rehab 1-2-3®, Our Town®, and WorkSyms® rehabilitation environments. Their designs simulate real-life situations to motivate patients by helping them connect their therapy to the life in which they aspire to return. Utilizing an empathic research process, Moore and Guynes build a deeper understanding of both patients’ and therapists’ values and apply that understanding to designs that are more directly connected to patients’ aspirational goals while still meeting their functional rehabilitation needs. This same rese...
Formation, isolation and composition of dense granules from mitochondria

Abstract 1. 1. An investigation was undertaken to determine if the electron-dense granules which accumulate in mitochondria under conditions of massive Ca2+-loading could be isolated and identified. 2. 2. Four methods are described for the isolation of dense granules from rat liver mitochondria. Three of these methods involve chemical destruction of the mitochondria. and liberation of the granules; the fourth involves disruption by sonication. 3. 3. The granules are amorphous, and consist of both organic and inorganic constituents. 4. 4. Incineration of the granules destroyed the organic moiety and induced crystallization of the inorganic constituents. 5. 5. Chemical analysis disclosed that Ca2+ and Pi are the major inorganic constituents. Mg2+ and CO2−3 also are present in significant amounts. 6. 6. X-ray diffraction analysis indicated that the patterns of the incinerated granules correspond to either hydroxyapatite, Ca10(PO4)6(OH)2, whitlockite, Ca3(PO4)2, or to a mixture of both. 7. 7. The isolation of the granules enabled a study of some of the factors which influence this active ion translocation in a more direct way than was hitherto possible.
Nuclear data sheets for A = 186

Abstract Spectroscopic data for all nuclei with mass number A=186 have been evaluated, and the corresponding level schemes from radioactive decay and reaction studies are presented. A new decay scheme has been proposed for 186 Tl ɛ decay (27.5 s), and an unobserved E3 isomeric transition from the 2−(2.0 h) isomer in 186 Ir is suggested. Also, a previously proposed isomer in 186 Au with T 1/2 5 y isomer in 186 Re. High-spin levels are only poorly known in 186 Re and it is proposed that 186 W(d,2n γ ) reaction studies would be valuable towards resolving this question.
Changing concepts in periodontics

Summary This article has concentrated on aspects of periodontics where research over the last decade has demonstrated that old concepts are outmoded and for the patient's benefit should be changed in clinical practice. The following statements were made. 1. Periodontal pockets do not need to be reduced surgically to a 3 mm limit to save teeth. 2. Bone and soft tissues do not need to be sculptured 3. Treated teeth can be maintained without loss of periodontal support with less than perfect plaque control if professional tooth cleaning every 3 months is practiced. 4. Furcation involvement complicates the treatment of periodontitis, but such teeth have a better prognosis than has been commonly thought. 5. Deep pockets have a relatively good prognosis after treatment. The problem is access for efficient root planing. 6. Advanced periodontitis can be stopped in most patients. 7. Gingival curettage does not improve the results of scaling and root planing. 8. Support for teeth can be maintained without attached gingiva. 9. Gingival blanching in response to lip pull is meaningless. 10. Splinting is not needed for most teeth with increased mobility after periodontal therapy.It was acknowledged that in other controversial aspects of periodontics scientific information still is not available to support firm concepts that may guide clinical practice. One problem in dentistry is the lag that often exists between the publication of research findings and their application in clinical practice if there is no inherent economic reward in the new procedure. Crown margins are still routinely placed subgingivally by dentists although it has been known for more than 20 years that this is a periodontal hazard.Patients are legally and morally entitled to give consent to the proposed treatment after they have been informed of what can be expected in terms of length of life for their teeth and quality of life for themselves.Allow patients to benefit from what has been learned in modern periodontics, and there will be fewer extractions, less surgery, and happier patients.
Mediastinal fibrin glue: hemostatic effect and tissue response in calves.

Abstract There is continued controversy regarding the effectiveness and potential adverse effects of fibrin glue. Thus, we chose to evaluate it in a model of experimental calf aortic valve replacement that has been previously well established. Concentrated fibrinogen and topical thrombin were sprayed to form a thin layer of fibrin glue over the mediastinal tissues of 20 consecutive calves undergoing aortic valve replacement. Chest tube outputs of these animals were compared with those of the preceding 20 consecutive calves undergoing aortic valve replacement without fibrin glue. All procedures were performed by the same surgeon, and no other technical changes were made between the two series. Total postoperative chest tube output (mean ± standard error) was 553 ± 50 mL for the calves treated with fibrin glue and 1,155 ± 103 mL for the control calves ( p
Stochastic model for surface erosion via ion sputtering: Dynamical evolution from ripple morphology to rough morphology.

Surfaces eroded by ion sputtering are sometimes observed to develop morphologies which are either ripple (periodic) or rough (nonperiodic). We introduce a discrete stochastic model that allows us to interpret these experimental observations within a unified framework. We find that a periodic ripple morphology characterizes the initial stages of the evolution, whereas the surface displays self-affine scaling in the later time regime. Further, we argue that the stochastic continuum equation describing the surface height is a noisy version of the Kuramoto-Sivashinsky equation.
An experimental evaluation of local search heuristics for graph partitioning

A common problem that arises in many applications is to partition the vertices of a graph intok subsets, each containing a bounded number of vertices, such that the number of graph edges with endpoints in different subsets is minimized. This paper describes an empirical study of the performance of various local search heuristics for thisk-way graph partitioning problem. The heuristics examined are local optimization, simulated annealing, tabu search, and genetic algorithms. In addition, the hierarchical hybrid approach is introduced, in which the problem is recursively decomposed into small pieces, to which local search heuristics are then applied.
Polymeric complexes and fragments of albumin in normal human plasma

Nitrocellulose blots of normal human plasma proteins separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis were examined for polymeric complexes and fragments of albumin using an immunoperoxidase-labelled mouse monoclonal anti-human albumin antibody. Under reducing conditions, no polymeric complexes were seen. Under non-reducing conditions, polymeric complexes were detected at the following molecular weights: 210 000, 168 000, 147 000, 132 000, and 110 000. These probably represent both homo- and heteropolymers of albumin. Fresh plasma samples were also analyzed by S-200 chromatography with the same results indicating that detection of polymeric complexes was not an artifact of the sodium dodecyl sulfate-polyacrylamide gel electrophoresis technique. In quantitative terms, polymeric complexes constituted 0.3-2.8% of the total albumin present. Fragments of albumin were also seen in normal human plasma with molecular weights of 45 000, 28 000 and 19 000. These fragments probably represent breakdown products of albumin in normal blood, and they constituted less than 2% of the total albumin present.
Urban Adolescents' Exposure to Community Violence: The Role of Support, School Safety, and Social Constraints in a School-Based Sample of Boys and Girls

This study examined recent exposure to violence in the community and in other settings, protective factors, and current psychological functioning among 349 young adolescents from 9 urban middle schools. The majority (76%) of adolescents reported witnessing or being victimized by at least 1 violent event in the prior 6 months. Nearly half of adolescents who had talked about their experience of a violent event reported feeling constrained from sharing their thoughts or feelings because of others' reactions. After controlling for daily hassles, more exposure to violence was associated with more self-reported posttraumatic stress disorder (PTSD) and depressive symptoms. Exposure to violence was not a significant predictor of teachers' ratings of adaptive functioning or internalizing symptoms. Support from specific individuals, perceived school safety, and lower constraints for discussing violence showed protective effects in the relation between exposure to violence and specific dimensions of psychological fu...
Emergency high-loop jejunostomy as enteral nutrition access: a simple and safe method.

BACKGROUND Emergency high-loop jejunostomies are seldom used for nutrition access in the clinical practice. METHODS This paper describes the results of a simple and safe technique that uses emergency high-loop jejunostomy as an enteral feeding access. A feeding tube is inserted into the efferent loop of the jejunostomy and then subcutaneously tunneled. In this way, whenever it becomes necessary, the bag collecting fluids from the afferent loop can be changed without removing the tube, which remains permanently inserted into the efferent loop and secured to the skin in order to avoid displacements. RESULTS Twenty-nine patients with high-loop jejunostomy were consecutively treated with the described technique during the period 2000-2006. The mean distance between the ligament of Treitz and tube was 38.3 +/- 16.2 cm. After an induction period, all patients received full-strength enteral nutrition and were discharged after a mean of 25.1 +/- 19.5 days of treatment. All patients were subsequently readmitted to our unit, and their ostomies were successfully closed. No major early and late complications were observed; particularly, no patient experienced local or systemic septic complications. CONCLUSION From the analysis of our results, the described method for delivering enteral nutrition through an emergency high-loop ostomy proves easy to apply and clinically effective. Enteral nutrition can be started as soon as possible after operation through the efferent loop of the ostomy; the management of the jejunostomy is simple and safe, with no additional discomfort for the patients.
EXCRECIÓN URINARIA DE ISOFLAVONAS EN ADULTOS MAYORES DE 65 AÑOS QUE CONSUMEN UN ALIMENTO FUNCIONAL

Resumen es: Los alimentos funcionales (AF) ejercen efectos beneficiosos en la salud. Las isoflavonas daidzeina y genisteina son fitoestrogenos bioactivos que pueden ...
Recovery management in QuickSilver

One price of extensibility and distribution, as implemented in QuickSilver, is a more complicated set of failure modes, and the consequent necessity of dealing with them. In traditional operating systems, services (e.g., file, display) are intrinsic pieces of the kernel. Process state is maintained in kernel tables, and the kernel contains explicit cleanup code (e.g., to close files, reclaim memory, and get rid of process images after hardware or software failures). QuickSilver, however, is structured according to the client-server model, and as in many systems of its type, system services are implemented by user-level processes that maintain a substantial amount of client process state. Examples of this state are the open files, screen windows, address space, etc., belonging to a process. Failure resilience in such an environment requires that clients and servers be aware of problems involving each other. Examples of the way one would like the system to behave include having files closed and windows removed from the screen when a client terminates, and having clients see bad return codes (rather than hanging) when a file server crashes. This motivates a number of design goals:Properly written programs (especially servers) should be resilient to external process and machine failures, and should be able to recover all resources associated with failed entities.Server processes should contain their own recovery code. The kernel should not make any distinction between system service processes and normal application processes.To avoid the proliferation of ad-hoc recovery mechanisms, there should be a uniform system-wide architecture for recovery management.A client may invoke several independent servers to perform a set of logically related activitites (a unit of work) that must execute atomically in the presence of failures, that is, either all the related activities should occur or none of them should. The recovery mechanism should support this.In QuickSilver, recovery is based on the database notion of atomic transactions, which are made available as a system service to be used by other, higher-level servers. This allows meeting all the above design goals. Software portability is important in the QuickSilver environment, dictating that transaction-based recovery be accessible to conventional programming languages rather than a special-purpose one such as Argus [Liskov84]. To accommodate servers with diverse recovery demands, the low-level primitives of commit coordination and log recovery are exposed directly rather than building recovery on top of a stable-storage mechanism such as in CPR [Attanasio87] or recoverable objects such as those in Camelot [Spector87] or Clouds [Allchin&McKendry83].
Design, Analysis, Fabrication and Test of an Aspirated Fan Stage

A fan stage designed by means of a MISES-based quasi-3D approach (Youngren and Drela, 1991), for a pressure ratio of 1.6 at a tip Mach number of 0.7, has been analyzed by viscous 3D CFD, fabricated and tested in the MIT Blowdown Compressor. The design incorporates a rotor tip shroud and boundary layer removal on the suction surfaces of the rotor and stator and at other critical locations. The fully viscous 3D analysis enabled final detailing of the design. In tests, the stage has met its design objectives, producing the design pressure ratio of 1.6 at design speed. The mass flow removed totaled 4.7%, approximately 1.0% through slots on the suction surface of the rotor and stator, and the remainder distributed over the rotor shroud and stator hub. The measured adiabatic efficiency of the rotor for the throughflow was 96% at the design point and that for the stage was 90%. This paper presents the design, the results of the analysis and the experimental stage performance both at design and at some off-design conditions.Copyright © 2000 by ASME
Implementing minimal clock skew Directed Logic

Abstract Although the physics of computing allows the possibility of logic operations with no energy dissipation, over 40 years of work by brilliant scientists in many fields has not achieved it. The solution described here required breaking from the tacit assumptions that logic gates had to be electronic. The system is implemented entirely with passive optical components. Also needed was a logic that could utilize those passive components. Hardy and Shamir showed how to map a Boolean logic problem into a form suitable to be implemented by light flowing through various paths and cascaded as needed. This paper examines a modular approach to implementing their approach (called Directed Logic) in an integrated optical system. We start from unit cells, implementing a dynamic flip–flop principle and combine the cells in a network or “logic fabric.” Contrary to proofs by the founders of this field, speed is limited only by the message bandwidth of the optical signal, and, of course, no energy is dissipated. There are still aspects that need additional work on issues like accuracy using analog components and size relative to electronics. But the basic problem is solved at last and paths toward solving the remaining problems have been identified.
Outcomes associated with resident involvement in laparoscopic colorectal surgery suggest a need for earlier and more intensive resident training.

Purpose The aim of this study is to determine if resident involvement in a large cohort of laparoscopic colorectal surgery (LCS) cases negatively impacts outcomes and ultimately increases costs. Methods The American College of Surgeons National Surgical Quality Improvement Program database was queried for patients who underwent LCS between 2005 and 2010. Patients were classified into two groups: postgraduate year (PGY; resident involvement) or Attending Only. A subgroup analysis was then conducted among the individual PGY levels (1–2, 3–5, ≥6) and Attending Only group. Results A total of 4,836 patients were included in the PGY group and 2,418 in the Attending Only group. Mean operative time (163.9 ± 66.7 vs. 140.7 ± 67.2 minutes, P Conclusion Although resident participation in LCS does not affect overall mortality or morbidity, it may negatively impact hospital costs through increased operative time and length of hospital stay. Early and intensive laparoscopy training may be necessary for improving residents' laparoscopy skills before their involvement in LCS.
Effect of particle size distribution in determining a powder's fractal dimension by single gas BET: A mathematical model

Abstract It is shown that particle size distribution plays an important role in determining the fractal dimension of a material when using gas adsorption techniques. The model currently being used to determine a material's fractal dimension is examined. In many cases this model works well. However, it is shown that errors may result if this model is applied to samples with specific particle size distributions. A new mathematical model which incorporates the particle size distribution is proposed. The new model is shown to produce the correct value for the fractal dimension under a number of conditions for which the current method fails. Conditions under which the currently used model can be expected to perform well are also given.
Community-acquired methicillin-resistant Staphylococcus aureus in southern New England children.

Objective. This study was performed to understand the epidemiology of community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) infections in southern New England children. Methods. A retrospective review was conducted of the medical records of children 0 to 18 years old with MRSA isolated by the Rhode Island Hospital microbiology laboratory (Providence, RI) between 1997 and 2001. A case was classified as either health care-associated MRSA (HCA-MRSA) or CA-MRSA based on time of culture and other strict criteria. The spectrum of illness of the HCA-MRSA and CA-MRSA cases was compared, as were the antibiotic-susceptibility patterns of their isolates. Risk factors for CA-MRSA acquisition were identified, and molecular subtyping of selected isolates was performed. Results. Between 1997 and 2001, S aureus was isolated from 1063 children. Of these children, 57 had MRSA. During this period, both the absolute number of MRSA cases and the proportion of S aureus cases due to MRSA rose more than threefold due to increases in both CA-MRSA and HCA-MRSA infections. Of the 57 MRSA cases, 23 (40%) were CA-MRSA. CA-MRSA patients were more likely to have skin/soft-tissue infections than HCA-MRSA patients (83% vs 38%). Risk factors for acquisition of MRSA including intrafamilial spread, frequent antibiotic exposure, and child-care attendance were identified in 8 of the 23 (35%) CA-MRSA patients. CA-MRSA isolates were more likely to be susceptible to non-β-lactam antibiotics than HCA-MRSA isolates. All isolates were vancomycin susceptible. Conclusions. MRSA accounts for an increasing proportion of all pediatric S aureus infections in southern New England. A significant percentage of these cases are due to CA-MRSA. Pediatricians should have heightened suspicion for CA-MRSA in children with presumed S aureus infections, especially if they have skin/soft-tissue infections or risk factors for MRSA acquisition.
J.H. King on Initial Evidence: Did He Change?

J.H. King, who is commonly viewed as one of the most important early twentieth-century Pentecostal leaders in the United States, was one of the strong proponents of the teaching that tongues speech is the invariable, immediate evidence of Spirit Baptism. Douglas Jacobsen argues in his 2003 book, Thinking in the Spirit, that King modified his position on normative initial evidence tongues in the second edition of From Passover to Pentecost. This article challenges that thesis. After looking at King’s pro-initial evidence polemic in the ‘Introduction’ of G.F. Taylor’s The Spirit and the Bride, and especially in the first edition of From Passover to Pentecost, this article deals with some King remarks in the second edition of the latter volume—remarks that Jacobsen interprets as King vacillating in his understanding of that doctrine. The bulk of the article contends that Jacobsen’s reading amounts to a substantial historical and literary decontextualization of those statements. Rather than interpreting them as King equivocating on initial evidence, they are more accurately understood as King articulating Christian prophetic ministry as (1) the supreme sign of the inaugurated ‘Pentecostal Era’, and as (2) a post-Spirit Baptismal confirmation of a genuine, tongue-certified Spirit Baptism experience.
Epilogue: What 2012 nomination contests tell us about the future of the Republican Party

Abstract Analysis of Tea Party activists within the Republican Party illustrates the “good-news, bad-news” aspects of intra-party factionalism. The good news is that nomination contests between Tea Party and establishment Republicans, divisive as they appear, do not necessarily undermine support for the party's nominees in the general election. Support for Tea Party candidates among its activists in the 2012 presidential nomination fight produced increased support for Romney–Ryan in the general election. At the same time, however, activism for Tea Party candidates contributed to increased negativity towards the Republican Party among Tea Party activists, suggesting that the factionalism within the party is unlikely to be soon resolved. Finally we find that negativity towards the Republican establishment is playing an even greater role than negativity towards President Obama in producing continuing or increased Tea Party movement activity. This suggests that the movement has the potential to survive beyond Obama's presidency.
Additive manufacturing of metallic cellular materials via three-dimensional printing

Cellular materials, metallic bodies with gaseous voids interspersed throughout the solid body, are a promising class of materials that offer high strength accompanied by a relatively low mass. Recent research has focused in the topological design of cellular materials in order to satisfy multiple design objectives. Unfortunately, these design advances have not been met with similar advances in cellular material manufacturing as existing techniques constrain a designer to a predetermined part mesostructure, material type, and macrostructure. In an effort to address these limitations, the authors have developed a manufacturing process chain centered on an augmented three-dimensional printing process. Specifically, metallic cellular materials are made by selectively printing solvent into a bed of spray-dried metal oxide ceramic powder. The resulting green part is then sintered in a reducing atmosphere to chemically convert it to metal. The resultant process has produced maraging steel cellular artifacts featuring a 270-μm wall thickness and angled trusses and channels that are less than 1 mm in diameter.
Improved Synthesis and X-Ray Crystallographic Structure Determination of the Stereoisomeric K-Region Arene Dioxides of Pyrene and Dibenz[a, h]Anthracene [1]

Abstract In the work reported here we describe an improved procedure for the use of dimethyl-dioxirane, 1, to prepare arene dioxides as well as the isolation and X-ray structure determination of the stereoisomeric dioxides from pyrene, 2, and dibenz[a, h]anthracene, 3. In the case of 2 the dioxides are formed in a 75:25 ratio (cis/trans) and for 3 the dioxide ratio is 45:55 (cis/trans). The X-ray crystallographic structures of both cis dioxides reveal that the oxide groups confer a curvature to the molecular structures.
Low Vitamin B6 but Not Homocyst(e)ine Is Associated With Increased Risk of Stroke and Transient Ischemic Attack in the Era of Folic Acid Grain Fortification

Background and Purpose— The introduction of cereal grain folic acid fortification in 1998 has reduced homocyst(e)ine (tHcy) concentrations in the US population. We performed a case-control study to determine the risk of stroke and transient ischemic attack (TIA) associated with tHcy and low vitamin status in a postfortification US sample. Methods— Consecutive cases with new ischemic stroke/TIA were compared with matched controls. Fasting tHcy, folate, pyridoxal 5′-phosphate (PLP), B12, and MTHFR 677C→T genotype were measured. Results— Mean PLP was significantly lower in cases than controls (39.97 versus 84.1 nmol/L, P<0.0001). After stroke risk factors were controlled for, a strong independent association was present between stroke/TIA and low PLP (adjusted odds ratio [OR], 4.6; 95% CI, 1.4 to 15.1; P<0.001) but not elevated tHcy (OR, 0.92; 95% CI, 0.4 to 2.1). Conclusions— Low B6 but not tHcy was strongly associated with cerebrovascular disease in this postfortification, folate-replete sample.
Parasite competition hidden by correlated coinfection: using surveys and experiments to understand parasite interactions

Within most free-living species exists a cryptic community of interacting parasites. By combining multiscale field data with manipulative experiments, we evaluated patterns of parasite coinfection in amphibian hosts and their underlying mechanisms. Surveys of 86 wetlands and 1273 hosts revealed positive correlations between two pathogenic trematodes (Ribeiroia ondatrae and Echinostoma trivolvis) both between wetlands and within individual hosts. In infection and coinfection experiments, Ribeiroia caused greater pathology than Echinostoma, including high host mortality (24%) and severe limb malformations (75%). No interactive effects were noted for host pathology, but both parasites decreased the per capita persistence of one another by 17-36%. Thus, in spite of consistently positive associations from field data, these parasites negatively affected the persistence of one another, likely via cross immunity (apparent competition). These findings underscore the danger of inferring parasite interactions from coinfection patterns and emphasize the potential disconnect between within-host processes (e.g., competition) and between-host processes (e.g., exposure and transmission). Here, correlated coinfections likely resulted from similarities in the parasites' host requirements and heterogeneity in host susceptibility or exposure. Understanding complex interactions among parasites depends critically on the scale under consideration, highlighting the importance of combining coinfection field studies with mechanistic experiments.
Issues in assessing environmental exposures to manufactured nanomaterials.

Manufactured nanomaterials (MNs) are commonly considered to be commercial products possessing at least one dimension in the size range of 10−9 m to 10−7 m. As particles in this size range represent the smaller fraction of colloidal particles characterized by dimensions of 10−9 m to 10−6 m, they differ from both molecular species and bulk particulate matter in the sense that they are unlikely to exhibit significant settling under normal gravitational conditions and they are also likely to exhibit significantly diminished diffusivities (when compared to truly dissolved species) in environmental media. As air/water, air/soil, and water/soil intermedium transport is governed by diffusive processes in the absence of significant gravitational and inertial impaction processes in environmental systems, models of MN environmental intermedium transport behavior will likely require an emphasis on kinetic approaches. This review focuses on the likely environmental fate and transport of MNs in atmospheric and aquatic systems. Should significant atmospheric MNs emission occur, previous observations suggest that MNs may likely exhibit an atmospheric residence time of ten to twenty days. Moreover, while atmospheric MN aggregates in a size range of 10−7 m to 10−6 m will likely be most mobile, they are least likely to deposit in the human respiratory system. An examination of various procedures including the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory of colloidal particle suspension stability in water indicates that more sophisticated approaches may be necessary in order to develop aquatic exposure models of acceptable uncertainty. In addition, concepts such as Critical Coagulation Concentrations and Critical Zeta Potentials may prove to be quite useful in environmental aquatic exposure assessments.
Biogeochemical stoichiometry of Antarctic Dry Valley ecosystems

operate over 10–10 6 years. The simple organisms (microbial and metazoan) comprising dry valley foodwebs adhere to strict biochemical requirements in the composition of their biomass, and when activated by availability of liquid water, they influence the chemical composition of their environment according to these ratios. Nitrogen and phosphorus varied significantly in terrestrial and aquatic ecosystems occurring on landscape surfaces across a wide range of exposure ages, indicating strong influences of landscape development and geochemistry on nutrient availability. Biota control the elemental ratio of stream waters, while geochemical stoichiometry (e.g., weathering, atmospheric deposition) evidently limits the distribution of soil invertebrates. We present a conceptual model describing transformations across dry valley landscapes facilitated by exchanges of liquid water and biotic processing of dissolved nutrients. We conclude that contemporary ecosystem stoichiometry of Antarctic Dry Valley soils, glaciers, streams, and lakes results from a combination of extant biological processes superimposed on a legacy of landscape processes and previous climates.
Bacterial Communities Associated with Lesions of Shell Disease in the American Lobster, Homarus americanus Milne-Edwards

ABSTRACT Shell disease in Crustacea is a widely recognized syndrome having a polymicrobial etiology, and manifesting itself as lesions of the shell with a variable structure and shell location. We characterized major members of bacterial communities in epizootic shell disease lesions of the American lobster (Homarus americanus, Milne Edwards) and compared these communities with the ones found in study cases of impoundment and enzootic shell disease. Bacteria belonging to several Flavobacteriaceae genera (Aquimarina, Tenacibaculum, Polaribacter, Maribacter, Cellulophaga) within the phylum Bacteroidetes appear to have particular attraction to lobster lesions. The most prominent Bacteroidetes in lobster lesions were representatives of the genus Aquimarina sp., but only Aquimarina ‘homaria’ was detected in all analyzed lesions of epizootic, impoundment, and enzootic shell disease. It was found on 45% of surfaces unaffected by shell disease, but in smaller numbers compared with lesions. Alphaproteobacteria rep...
Overview of randomized clinical trials of total parenteral nutrition for malnourished surgical patients

The past decade has seen a maturation of the art and science of perioperative nutritional support. We now have sufficient data to make informed and reasonable judgments regarding when we should and should not provide perioperative TPN. These judgments can be considered medically sound and fiscally responsible. The following guidelines are proposed: (1) Postoperative TPN should be considered when oral or enteral feeding is not anticipated within 7 to 10 days in previously well-nourished patients or within 5 to 7 days in previously malnourished or critically ill patients. (2) Preoperative TPN should be considered in patients who cannot or should not eat or receive enteral feedings if the operation must be delayed for more than 3 to 5 days. (3) Preoperative TPN should be considered in the most severely malnourished surgical candidates if an operative delay is not contraindicated. In patients with only mild to moderate degrees of malnutrition preoperative TPN is not indicated.
The Effects of Local Activity on Neighborhood Attitudes: A Comparison of Black and White Urbanites.

Previous sociological research concerning the effects of urban living upon city dwellers has not addressed the question of whether satisfaction with and attachment to one's urban neighborhood are related to the amount of local facility use and local social interaction a resident displays. Since blacks ordinarily perform fewer activities locally than do whites, it is also of interest whether their community attitudes are dependent on these activities to a different extent than might be the case with whites. This article reports findings indicating that blacks' neighborhood satisfaction and attachment depend very little upon the extent of their activity within their communities.
The role of glutamine in maintaining a healthy gut and supporting the metabolic response to injury and infection

In the critically ill surgical patient a variety of therapeutic maneuvers is required to maintain a "healthy gut." Provision of adequate amounts of glutamine to the gastrointestinal mucosa appears to be just one of these maneuvers. Other methods utilized to protect the gut from becoming a wound include: (a) minimizing additional systemic insults (such as hypotension, sepsis, multiple operative procedures); (b) aggressive pulmonary care; (c) the judicious use of antibiotics; and (d) aggressive enteral or parenteral feedings. The concept that the gut is an organ of quiescence following surgical stress merits reconsideration. The intestinal tract plays a central role in interorgan glutamine metabolism and is a key regulator of nitrogen handling following surgical stress. Critically ill patients are susceptible to developing gut-origin sepsis, the incidence of which will be diminished by instituting measures and providing treatments which support intestinal structure, function, and metabolism. Provision of glutamine-enriched diets to such patients may be one of these therapies.
Genetically lean mice result from targeted disruption of the RIIβ subunit of protein kinase A

CYCLIC AMP is an important second messenger in the coordinated regulation of cellular metabolism. Its effects are mediated by cAMP-dependent protein kinase (PKA), which is assembled from two regulatory (R) and two catalytic (C) subunits. In mice there are four R genes (encoding RIα, RIβ, RIIα, and RIIβ) and two C genes (encoding Cα and Cβ), expressed in tissue-specific patterns1. The RIIβ isoform is abundant in brown and white adipose tissue and brain, with limited expression elsewhere. To elucidate its functions, we generated RIIβ knockout mice. Here we report that mutants appear healthy but have markedly diminished white adipose tissue despite normal food intake. They are protected against developing diet-induced obesity and fatty livers. Mutant brown adipose tissue exhibits a compensatory increase in RIα, which almost entirely replaces lost RIIβ, generating an isoform switch. The holoenzyme from mutant adipose tissue binds cAMP more avidly and is more easily activated than wild-type enzyme. This causes induction of uncoupling protein and elevations of metabolic rate and body temperature, contributing to the lean phenotype. Our results demonstrate a role for the RIIβ holoenzyme in regulating energy balance and adiposity.
Eating as both coping and stressor in overweight control

Eating as both coping and stressor in overweight control Aim. The aim of this study was to test a conceptual model proposing that stress evokes eating as coping, that eating then becomes a stressor in itself, and that a coping repertoire specific for overeating is required to moderate its yield of negative mood states. Background. It is known that stressors may evoke eating as a coping response, and that some persons respond to lapses in their dietary regimen with depression and self-criticism. These two findings are linked within the context of a stress and coping paradigm that has in the past been applied to the study of substance abuse. Method. A survey of 79 women who reported overeating was implemented, including the administration of five instruments and a telephone interview. Findings. Over 43% of the variance in the dependent variable, negative mood states, was explained by hierarchical regression of the independent variables, entered sequentially as exemplars of: social stressors, coping, degree of required calorie consumption, use of overweight control strategies and the interaction between the degree of required weekly calorie consumption and use of overweight control strategies. Significant contributions were made by variables denoting stressors, coping, and the interaction between degree of required calorie consumption and use of overweight control strategies. Of particular interest was the suggestion that for individuals who frequently use strategies to control overeating and overweight, eating may produce negative mood states. Individuals intensively involved in efforts to control their weight may be vulnerable for dysphoria, may require unique nursing interventions, and thus deserve continued study in this context.
SU‐E‐T‐406: Use of TrueBeam Developer Mode and API to Increase the Efficiency and Accuracy of Commissioning Measurements for the Varian EDGE Stereotactic Linac

Purpose: The Varian EDGE machine is a new stereotactic platform, combining Calypso and VisionRT localization systems with a stereotactic linac. The system includes TrueBeam DeveloperMode, making possible the use of XML-scripting for automation of linac-related tasks. This study details the use of DeveloperMode to automate commissioning tasks for Varian EDGE, thereby improving efficiency and measurement consistency. Methods: XML-scripting was used for various commissioning tasks,including couch model verification,beam-scanning,and isocenter verification. For couch measurements, point measurements were acquired for several field sizes (2×2,4×4,10×10cm{sup 2}) at 42 gantry angles for two couch-models. Measurements were acquired with variations in couch position(rails in/out,couch shifted in each of motion axes) compared to treatment planning system(TPS)-calculated values,which were logged automatically through advanced planning interface(API) scripting functionality. For beam scanning, XML-scripts were used to create custom MLC-apertures. For isocenter verification, XML-scripts were used to automate various Winston-Lutz-type tests. Results: For couch measurements, the time required for each set of angles was approximately 9 minutes. Without scripting, each set required approximately 12 minutes. Automated measurements required only one physicist, while manual measurements required at least two physicists to handle linac positions/beams and data recording. MLC apertures were generated outside of the TPS,and with the .xml file format, double-checking withoutmore » use of TPS/operator console was possible. Similar time efficiency gains were found for isocenter verification measurements Conclusion: The use of XML scripting in TrueBeam DeveloperMode allows for efficient and accurate data acquisition during commissioning. The efficiency improvement is most pronounced for iterative measurements, exemplified by the time savings for couch modeling measurements(approximately 10 hours). The scripting also allowed for creation of the files in advance without requiring access to TPS. The API scripting functionality enabled efficient creation/mining of TPS data. Finally, automation reduces the potential for human error in entering linac values at the machine console,and the script provides a log of measurements acquired for each session. This research was supported in part by a grant from Varian Medical Systems, Palo Alto, CA.« less
Outsourcing the procurement function: Do actions and results align with theory?

Abstract Are common theories of outsourcing useful in predicting the extent of and performance gains from the outsourcing of procurement activities? Or does procurement׳s broad scope and boundary-spanning role confound successful analysis? This study applies a theoretical framework combining concepts from transaction-cost economics (TCE) and the resource-based view (RBV) to study the procurement outsourcing decisions of two hundred and eighty US-based electronics manufacturing firms. Findings suggest that TCE and RBV act in complementary ways on the procurement outsourcing decision. TCE, through fear of supplier opportunism, appears to be the primary driver of the extent to which procurement activities are outsourced. The RBV, through which the OEM׳s resource position in procurement vis-a-vis its outsourcing partner is determined, appears to be the primary determinant of the performance results of the outsourcing decision. Procurement activities are outsourced to a greater extent when fear of supplier opportunism is low, but such outsourcing is only “justified” (expected to yield performance benefits) when the OEM has a weak resource position vis-a-vis the outsourcing partner. An “enriched” TCE–RBV framework is presented and discussed as part of study results.
A simple distal radioulnar joint orthosis

These authors describe an orthosis they have successfully used in their clinic to treat patients with distal radioulnar joint instability. In addition to describing how they fabricate the orthosis, these authors also describe how they determine if the patient needs volar or dorsal support, and how they then incorporate this support into the orthosis - Victoria Priganc, PhD, OTR, CHT, CLT, Practice Forum Editor.