cssi/SciSciGPT-SciSciNet huggingface dataset:
Stick-Slip Fracture of Polymer/Metal Interfaces

The adhesion of a thin-film of PMMA to substrates consisting of Ti or Al was measured using a four-point bend technique. Initial results revealed that cracks propagated along the PMMA/metal interfaces at stable rates. Subsequent experiments showed intermittent (“stick-slip”) interfacial crack propagation consisting of cycles of crack initiation, unstable propagation, and arrest. To investigate the origin of stick-slip fracture behavior at PMMA/metal interfaces the effect of water uptake by PMMA on fracture behavior was studied. Four-point bend sandwich specimens were stored in vacuum or deionized water environments at either 25 °C or 65 °C for a period of 7 days prior to testing. The PMMA/Al system stored at 25 °C showed a transition from stable to stick-slip crack propagation when the exposure environment was changed from vacuum to water. Interface crack propagation was stable for both the PMMA/Ti and PMMA/Al systems on exposure to 65 °C water, but the critical strain energy release rate, G C was markedly reduced, indicating that water uptake promoted stick-slip fracture up to some critical degree of hydration. No change in stick-slip behavior was observed from a variation in imposed load-point displacement rate.
Fitness consequences of pheromone production and host selection strategies in a tree-killing bark beetle (Coleoptera: Curculionidae: Scolytinae)

Timing of arrival at a resource often determines an individual's reproductive success. Tree-killing bark beetles can reproduce in healthy trees by attacking in adequate numbers to overcome host defences that could otherwise be lethal. This process is mediated by aggregation and antiaggregation pheromones. Beetles that arrive early in such a "mass attack" must contend with undiminished tree defences, and produce enough pheromones to attract more beetles, but have a head start on gallery construction and egg-laying. Beetles that arrive late may be impeded by competition and diminishing availability of phloem, but should experience fewer costs associated with pheromone production and battling tree defences. We investigated relationships between timing of arrival, body size, pheromone production and fitness in the southern pine beetle, Dendroctonus frontalis. In field experiments, we captured beetles that arrived early (pioneers) and late on slash pine trees, Pinus elliottii, and measured pheromone amounts in their hindguts. We marked gallery entrances of beetles as they landed on a tree and measured their reproductive success after the attack terminated. We found no difference in body size or pheromone amounts between early and late arrivers. Most beetles arrived at the middle of the attack sequence, and excavated longer galleries per day than early arrivers. The number of offspring produced per day by beetles that established galleries midway through mass attack was higher than those that arrived early or very late in the sequence. Our results suggest that beetles do not exhibit adaptive phenotypic plasticity in pre-landing pheromone production, depending on the extent of previous colonisation of a host. Rather, it appears that stabilising selection favours beetles that attack in the middle of the sequence, and contributes to attack synchrony. Synchronous attack on trees is essential before population booms characteristic of tree-killing bark beetles can occur in nature.
Estrogen induction of LH release in the Rhesus monkey.

Subcutaneous injections of estradiol benzoate in oil, resulting in a sustained elevation of circulating estrogen levels, induced LH discharges markedly similar to the spontaneous preovulatory LH surges observed during the normal menstrual cycle. Exogenous estrogen leading to high plasma estrogen concentrations for brief periods (less than 12 hr) was ineffective in this regard. The discharge of LH in response to estrogen administration was observed in cycling and in ovariectomized females but not in intact males or in lactating females. It is concluded that the “trigger” for LH discharge, in the rhesus monkey, consists of an effective increment in circulating estrogen levels which must be maintained for at least 12 hr and that this positive feedback action of the steroid is clearly operative only in nonlactating adult females. (Endocrinology 89: 1034, 1971)
Syntheses and structures of bis(azido)- and bis(tert-butoxy)cyclodistibazanes.

Treatment of the dichlorocyclodistibazane [ClSb(μ-NtBu)2SbCl] with alkali-metal azides or tert-butoxides afforded trans-[N3Sb(μ-NtBu)2SbN3] and trans-[tBuOSb(μ-NtBu)2SbOtBu], respectively. These da...
The reaction of H2S with the photosynthetic water-oxidizing complex and its lack of reaction with the primary electron acceptor in spinach

Inhibition of photosynthetic water oxidation by H2S, a substrate analog, has been investigated using equilibrium titrations and EPR spectroscopic detection of the electron donors in spinach Photosystem II (PS II) membranes and compared to inhibition by NH2OH. Like NH2OH, H2S inhibits formation of the S2 oxidation state of the water oxidizing complex by a two-step process in the dark. Initially, reversible inhibition of S2 occurs upon binding to a high affinity site in the dark (S1) state at a low concentration of inhibitor (50% inhibition: 0.07 μmol H2S/mg Chl, corresponding to about 15 H2S/PS II). This causes no loss of steady-state O2 evolution and can be reversed by illumination at room temperature, which causes multiple turnovers. At higher concentrations, irreversible inhibition occurs due to the cooperative release of 3 out of 4 Mn2+/PS II using mild washing conditions, with parallel loss of O2 evolution activity. This stoichiometry of Mn release is preserved throughout the entire concentration range of inhibition by both H2S and NH2OH, suggesting a common binding site for at least 3, and possibly all 4, of the Mn ions which are present in PS II. This consistent with independent earlier work showing the net release of 4 Mn/PS II using stronger washing conditions, and also with EPR spectroscopic evidence assigning the S2 multiline signal to a cluster of 3–4 Mn ions. The concentration of H2S which induces 50% irreversible inhibition is 17-fold greater than that required for NH2OH. Qualitatively, the weakerinhibition by H2S is consistent with its lower oxidation potential compared to N2OH. However, the quantitative agreement is poor, suggesting that other environmental factors must be involved in determining their relative inhibition strenghts. Unlike NH2OH, H2S does not affect the structure of the primary quinone electron acceptor, QA−-His-Fe (structure by analogy to bacterial reaction centers), as seen by formation of the normal EPR signals at g = 1.8 and g = 1.9 for the photoreduced semiquinone, instead of shifted resonance at g = 2.1 observed with NH2OH. H2S is therfore unable to bind to the NH2OH site on the acceptor side of PS II.
Endothelial responses to mechanical stress: where is the mechanosensor?

Objective: The endothelium is normally subjected to mechanical deformation resulting from shear stress and from strain associated with stretch of the vessel wall. These stimuli are detected by a mechanosensor that initiates a variety of signaling systems responsible for triggering the functional responses. The identity of the mechanosensor has not been established. This article discusses the different mechanisms of mechanosensing that have been proposed and reviews the literature with respect to signaling systems that are activated in response to stress and strain in endothelium. Data Sources: Published literature related to mechanotransduction, signal transduction pathways initiated by strain in endothelium, and pathophysiologic effects of abnormal shear forces in diseases. Data Extraction and Synthesis: Proposed mechanisms of mechanosensing include stretch-sensitive ion channels, protein kinases associated with the cytoskeleton, integrin-cytoskeletal interactions, cytoskeletal-nuclear interactions, and oxidase systems capable of generating reactive oxygen species. However, the molecular identity of the mechanosensor is not known, nor is it clear whether multiple sensing mechanisms exist. Conclusions: Many responses are initiated in cells subjected to mechanical deformation, including alterations in ion channel conductance, activation of signal transduction pathways, and altered expression of specific genes. Future progress in this field will require a critical distinction between cell systems that become activated during mechanical strain and the identity of the cellular mechanosensor that triggers subsequent responses.
1 * N Trust Establishment within Dynamic Collaborative Clouds

Federation of security entities in cloud environments has crucial challenges in terms of policy reservations required for each of the multi-tenancy requests. In collaborative clouds, the problem is compounded due to the fact that the tenancy requester would be completely unaware of the end cloud provider. As the tenancy requesters would not have established any negotiation terms with the end cloud provider, it is a complex challenge to ensure dependability in terms of trust, privacy and security of data exchanges. Existing approaches require establishment of point to point trust. However, in the larger context of possible collaborative cloud providers, there is a need for simplified trust management for tenants. Asking the tenants to exclusively establish trust relationships with each other hinders the choice of providers thereby restricting the dynamic collaborations. We propose an approach based on a model wherein a single security mediator is responsible for sharing the required trust with all involved cloud providers within the collaboration. This mediator acts as a hub for all the participant tenants. The tenants establish negotiation terms with the mediator. Whenever the tenancy request needs to be satisfied by a subsequent cloud provider, first a trust is established between the mediator and the new cloud provider. Once this level of trust is accepted and confirmed by the tenancy requester, this provider is added as a trusted provider and tenancy requests can be satisfied by this specific cloud provider.
Extracellular cyclic AMP-adenosine pathway in isolated adipocytes and adipose tissue.

Objective: Our goal was to evaluate the presence and lipolytic impact of the extracellular cyclic adenosine monophosphate (AMP)–adenosine pathway in adipose tissue. Research Methods and Procedures: Sixteen miniature Yucatan swine (Sus scrofa) were used for these in vitro and in situ experiments. Four microdialysis probes were implanted into subcutaneous adipose tissue and perfused at 2 μL/min with Ringer's solution containing no addition, varying levels of cyclic AMP, 10 μM isoproterenol, or 10 μM isoproterenol plus 1 mM α,β-methylene adenosine 5′-diphosphate (AMPCP), a 5′-nucleotidase inhibitor. Dialysate was assayed for AMP, adenosine, inosine, hypoxanthine, and glycerol. Freshly isolated adipocytes were incubated with buffer, 1 μM isoproterenol, or 1 μM isoproterenol plus 0.1 mM AMPCP, and extracellular levels of AMP, adenosine, inosine, hypoxanthine, and glycerol were measured. Results: Perfusion of adipose tissue with exogenous cyclic AMP caused a significant increase in AMP and adenosine appearance. Perfusion with AMPCP, in the presence or absence of isoproterenol, significantly increased the levels of AMP and glycerol, whereas it significantly reduced the level of adenosine and its metabolites. However, the AMPCP-provoked increase in lipolysis observed in situ and in vitro was not temporally associated with a decrease in adenosine. Discussion: These data suggest the existence of a cyclic AMP—adenosine pathway in adipocytes and adipose tissue. The role of this pathway in the regulation of lipolysis remains to be clarified.
Local information and the design of sequential hypothesis tests

Various results on sequential hypotheses testing are reviewed. Optimal stopping rules are related to a local measure of statistical information. In some cases, local information can be approximated by L-numbers discovered by Lorden, and simple rules based on these approximations are asymptotically optimal to better order than the cost for a single observation.
The Evolution of Web Governance in the Federal Government

Over the last 10 years, federal agencies have undergone a major transformation in the way they manage programs and internal administration, in their relations with Congress, and in their dealings with clients and citizens. Agencies now work in electronic environments of e-mail, electronic documents and filings, intranets, and the Internet. This article seeks to describe and to account for the emergence of what is now being termed Web governance. Briefly, Web governance is concerned with the control of content and design for agency Web sites. We explore the evolution of the process by which Web governance decisions are being made government-wide and at individual federal agencies. We look to changing patterns of administrative process in order to help account for the emergence of controls, and we find evidence of the importance of networking and of disbursed, self-designing processes.
Prostatic calculi: A review

Prostatic calculi are rare in children, infrequent below age 40, and common in males over 50. They may be solitary but usually occur in clusters and are associated with some other disease process (nodular hyperplasia, prostatic carcinoma, metabolic abnormalities). They are most often asymptomatic; however, symptoms that may be attributable to prostatic calculi include reduction of the urinary stream, prostatism, and intense lower back and leg pain. Treatment may be accomplished by transurethral resection, but prostatectomy is the best means to insure complete removal. Prostatic calculi may form by two related mechanisms with obstruction and stasis of prostatic fluid as central entities in both. These mechanisms are calcification of corpora amylacea and simple precipitation of prostatic secretion. They may arise spontaneously, initiating an inflammatory reaction that contributes to their growth, or they may arise as the consequence of another pathologic situation producing acinar obstruction. It appears that infection probably occurs secondary to stone formation.
Physical Plasma Switchability in the Brain

The brain is considered to be a seat of vast number of subvolumes of limited size containing mobile charge carriers. The ensembles of these carriers may undergo phase transitions between the states of noncollective and collective behavior. It is shown that these phase transitions may take place depending on the values of concentration, effective mass, and temperature of charge carriers, and the dielectric constant of the atomic lattice; all of them in coupling with the metabolic activity of the brain. The transitions between individual particles and classical plasma (as well as in the reverse direction) may happen as a result of the change, for example, in oxygen supply or pharmaceuticals.
A Social-Cognitive Model of Driver Aggression: Taking Situations and Individual Differences into Account

Aggressive driving is a phenomenon that has taken on tremendous significance in society. While the issue has been studied from perspectives of several disciplines, relatively few comprehensive empirical investigations have been conducted. This may be due, at least in part, to a scarcity of comprehensive theoretical works in the field, from which methodical research hypotheses could be derived. This paper reviews major extant theories of general aggression to offer a rationale for choosing a particular framework to apply to the topic of aggressive driving. The social-cognitive model of aggressive driving is recommended, as it takes into account wide-ranging cognitive, situational, and dispositional factors. Implications for future research are also considered.
Development and pilot testing of an operative competency assessment tool for pediatric direct laryngoscopy and rigid bronchoscopy

Objectives: To develop and pilot test an objective assessment of technical skills instrument for evaluation of residents' surgical performance of pediatric direct laryngoscopy and rigid bronchoscopy, with emphasis on feasibility, validity, and interrater agreement. Study Design: Prospective, unblinded educational quality-improvement project combining paired and unpaired observations. Methods: Objective Structured Assessment of Technical Skills (OSATS) evaluation instruments were developed from detailed faculty input. Two instruments were created: a surgical checklist and a global assessment of surgical performance. The instruments were tested in a simulation bronchoscopy course and in the operative suite. Paired observations were used to determine interrater agreement, whereas multiple evaluations were used to calculate construct validity and internal consistency. Results: Forty-four assessments were completed for 19 residents. Seven faculty members evaluated residents as they performed laryngoscopy and bronchoscopy in an animal simulation laboratory and in the operating room. The evaluation tool was found to be feasible. The interrater agreement for both instruments was significant at 80.4% to 84.6% (P ≤.0001). Construct validity was confirmed with increasing mean global and task specific scores by postgraduate year (P <.0001). Internal consistency, measured with Cronbach alpha, was high at 0.968. Conclusions: This pilot study suggests that a reliable and valid instrument for objective evaluation of surgical competency can be developed for pediatric direct laryngoscopy and rigid bronchoscopy. This instrument can be used for formative and summative feedback of operative performance. In addition, it was easy to use and valid in a limited evaluation; however, larger studies are required to validate its utility. Laryngoscope, 2010
Performance and costs of advanced sustainable central power plants with CCS and H2 co-production

Abstract With increasing concerns over global climate change caused by GHG emissions, carbon capture and storage (CCS) has become imperative for coal based power plants. Meanwhile, with the development and deployment of hybrid vehicles, electric vehicles, and alternative fuel vehicles, GHG reduction efforts in the power industry can also benefit the transportation sector. Power plants with H 2 co-production capability can contribute significantly in such development trends because H 2 powered fuel cell hybrid vehicles are very promising for future “zero emissions vehicles”. This work investigates the thermodynamic performance and cost advantage of employing advanced technologies currently under development for central power plants that (1) employ coal and biomass as feed stock; (2) co-produce power and high purity H 2 ; (3) capture most of the CO 2 evolved within the plants. Two system designs are developed: the first “base” case is an integrated gasification combined cycle (IGCC) system consisting of commercially ready technologies; the second “advanced” case is an integrated gasification fuel cell (IGFC) system. The feedstock employed consists of Utah bituminous coal along with two typical biomass resources, corn stover and cereal straw. The IGFC plant produces significantly higher amount of electricity for the same amounts of feedstock and H 2 export while the cost of producing the H 2 using a cost of electricity of $135/MW h is $1178/tonne for the IGFC case versus $2620/tonne for the IGCC case.
Investigation of Polymer Optical Fiber Drawing Force and Heat Transfer

In this study, the force required to draw a polymer preform into optical fiber is predicted and measured, along with the resultant free surface shape of the polymer, as it is heated in an enclosed cylindrical furnace. The applied drawing force affects the degree of chain alignment within the polymer. Chain alignment causes orientational birefringence, an unwanted property that attenuates any propagating optical signal. The draw force is a function of the highly temperature dependent polymer viscosity. Therefore accurate prediction of the drawing force requires a detailed investigation of the heat transfer within the furnace. In this investigation, the full axi-symmetric conjugate problem (including both natural convection and thermal radiation) was solved using the commercial finite element package FIDAP. In addition, the location of the polymer/air interface was solved for as part of the problem and was not prescribed beforehand. Results show that thermal radiation accounts for approximately 70% of the total heating experienced by the deforming polymer, but only 15% of the cooling. The draw force is very sensitive to both the furnace wall temperature and to the feed rate of the polymer. Numerical results compared well with the experimentally measured draw tension and neck-down profiles for several preform diameters, draw speeds, and furnace temperatures. The predicted draw forces were typically within 20% of the experimentally measured values.Copyright © 2003 by ASME
Morphometric Analysis of Primordial Follicle Number in Pigtailed Monkey Ovaries: Symmetry and Relationship with Age

We previously described a modern, three-dimensional counting method for determining primordial follicle (PF) numbers in primate ovaries using a combination of fractionator and physical dissector techniques. The purposes of our current study were 1) to apply our method to describe intraindividual differences in PF numbers between ovaries and 2) perform a linear regression analysis of age versus mean PF number per ovary. Ovaries from 16 pigtailed monkeys (Macaca nemestrina) age 0.85-12.5 yr were examined. Both ovaries were available from 11 subjects. The difference between ovaries ranged from 2% to 22% (mean +/- SD, 10 +/- 7%) and was not statistically significant. Regression analysis of data from all 16 subjects displayed a log-linear relationship according to the equation log N(a) = 4.8542 - 0.0714(age) where N(a) is the number of PF at a given chronological age. The fit for this model was highly significant (r(2) = 0.73, p </= 0.0001). Extrapolation of the model suggests that there are 71 483 PF in each ovary at the time of birth. We conclude that right and left ovaries differ little and that PF numbers follow a log-linear rate of decline during the reproductive years in this species.
Mitochondrial studies in senescent mice. I. Turnover of brain mitochondrial lipids.

Two groups of C57BL/6J female mice, age 2·5 months and 25 months, were injected with 14C acetate. Brain mitochondria were isolated at 2 days after injection and 3 weeks later. Lipids extracted from the mitochondria were chromatographed in 2 dimensions on silica-gel plates, and identified lipid spots were analyzed by liquid scintillation counting. The half-life of each component was calculated on the assumption that the label diminished logarithmically between the two sets of observations. Lecithin, cardiolipin, and phosphatidyl serine/phosphatidyl inositol possessed different half-lives, which were roughly similar in both age groups. By contrast, the half life of phosphatidyl ethanolamine was much longer in the older mice(118·2 days, as compared to 24·7 days in the young mice). The degree of labelling was somewhat less in the older group.
Osteogenic sarcoma of the jaws: factors influencing prognosis

Thirty cases of osteosarcoma of the jaws were reviewed (20 men and 10 women, mean age 34 years). Seventeen lesions occurred in the mandible and 13 in the maxilla. Swelling without pain was the most common presenting symptom. Thirteen lesions were initially misdiagnosed as odontogenic infections. Numbness as a presenting symptom was statistically associated with poor prognosis. Treatment included all combinations of surgery, chemotherapy and radiotherapy. Patients receiving chemotherapy with four or more agents showed a trend toward better survival with 71% alive and disease-free at the time of review. Patients' increasing age was statistically associated with decreased survival. The average age of survivors was 27 years and nonsurvivors, 40 years. Older patients suffered more local recurrences which, in all but one case, resulted in mortality. Expectedly, clear surgical margins correlated statistically with improved survival. With margins of less than 5 mm, 27% of patients were alive and disease-free as compared to 62% with surgical margins greater than 5 mm. The importance of early diagnosis, definitive surgical treatment and aggressive adjuvant chemotherapy is demonstrated. The Proportional Hazards Regression model was employed to evaluate the statistical significance of a variety of factors on disease-free and overall survival.
Differences in Predators of Artificial and Real Songbird Nests: Evidence of Bias in Artificial Nest Studies

In the past two decades, many researchers have used artificial nest to measure relative rates of nest predation. Recent comparisons show that real and artificial nests may not be depredated at the same rate, but no one has examined the mechanisms underlying these patterns. We determined differences in predator-specific predation rates of real and artificial nests. we used video cameras to monitor artificial nests baited with quail and plasticine eggs and Field Sparrow (Spizella pusilla) and Indigo Bunting (Passerina cyanea) nests in field habitats in central Missouri (U.S.A.). Although daily predation estimates (all predators pooled) were similar between artificial and real nests, predators differed substantially in their depredation of artificial verus real nests. snakes were the major predator at the real nest, and raccoons (Procyon lotor) were the major predator at artificial nests. we found strong support for models that distinguished predation between two or among threee predator groups and between artificial and real nests. there was no snake predation of artificial nests, and the oods of predation of artificial nests was 115-551% (95% confidence interval) and 2-154% of the odds of predation of real nests by mammals and birds, respectively. Artificial nests with plasticine eggs could not be used reliably to identify predators. In several cases plasticine eggs were marked by mice, and raccoons were recorded on video removing the quail egg. Because biases for artificial nests were positive for some predators and negative for other predators (and could be compensating), potentially existed for all predator groups, conclusions based on artificial nest studies should be suspect even when there is evidence that overall predation rates are similar among real and artificial nests.
Vaccination against hepatitis B in patients with chronic liver disease awaiting liver transplantation.

Background: Most transplant centers in the United States immunize patients awaiting liver transplantation against hepatitis B to prevent acquisition of hepatitis B through transplantation (de novo hepatitis B). A recent study showed that only 16% of patients with cirrhosis awaiting liver transplantation responded to single-dose recombinant vaccine. Methods: We studied the immunogenicity of double-dose recombinant vaccine in patients with cirrhosis awaiting liver transplantation. Results: Over a 4-year period (January 1994 to December 1997), 140 patients with cirrhosis without past or current hepatitis B infection were given double-dose recombinant vaccine (40 μg of Engerix B; SmithKline Beecham, Philadelphia, PA) at 0, 1 to 2, and 2 to 4 months. Hepatitis B surface antibody (HBsAb) was measured 1 to 3 months after completing vaccination. The response rate was 37%. However, HBsAb titers became undetectable in 35% of the responders during the post-transplant follow-up period. One hundred and thirty-seven patients underwent 144 liver transplantation procedures during the study period, and 3 patients developed de novo hepatitis B (2.2%). Livers transplanted from hepatitis B core antibody (HBcAb)-positive donors was the source of de novo hepatitis B in all cases. Two of the 3 patients who developed de novo hepatitis B were immunized before transplantation and one of them was a responder. Conclusion: Although the response rate to double-dose recombinant vaccines is higher than the previously reported response to single-dose vaccine, it still is less than optimal.
A Review of “Smoking and Health”

(1965). A Review of “Smoking and Health”. Journal of the American Statistical Association: Vol. 60, No. 311, pp. 722-739.
Fetal Growth Retardation and Increased Infant Mortaliy at High Altitide

Abstract An examination of recent Colorado vital statistics records was performed. The records included 194,526 live births and 3,100 infant deaths occurring during the years 1969-73, and some 466,000 live births and 71,000 infant deaths occurring during 1960-71. Birth weights at high altitude (2,744 to 3,100 m) were found to be reduced owing to retardation of intrauterine growth rather than preterm delivery. Despite decreased infant mortality at all altitudes in Colorado during the last 20 years, the infant mortality rate at high altitude remains almost twice that seen in Denver. The elevated mortality at high altitude occurred within 28 days after birth, primarily in preterm (< 38 weeks) infants. It appears that high altitude, possibly through the mechanism of exaggerated fetal hypoxia, retards fetal growth and increases the mortality rate of preterm infants.
2D damping predictions of fiber composite plates: Layup effects

Several two-dimensional theories for predicting the specific damping capacity (SDC) of fiber composite laminates are compared. The theories considered are those of Adams and Bacon, Adams and Maheri, Ni and Adams and Saravanos and Chamis. No interlaminar effects are considered. Results show that the theory of Saravanos and Chamis provides the most consistent fit to experimental results for a range of material properties and laminate layups. For some laminates, however, the Saravanos and Chamis method seems to predict the wrong trend in SDC variation versus layup angle. It is not clear from the current work whether this result is due to the absence of interlaminar effects in the theory or the presence of a three-dimensional stress state in the laminate.
Effects of Lipid A on the Immunologic Properties of Liposomal Model Membranes

Incorporation of lipid A influences the immunogenic properties of liposomal model membranes that carry N-(hapten)-substituted derivatives of phosphatidylethanolamine as antigenic determinants. These effects of lipid A include (1) a marked enhancement of the hapten-specific response; (2) abolition of the requirement of critical threshold epitope density for liposomal immunogenicity; and (3) conversion of liposomes from a thymus-independent type 2 to a thymus-independent type 1 immunogen. Recent experiments demonstrate that an optimal in vitro response to liposomes-although originally classified as thymus-independent on the basis of conventional criteria-requires two T cell factors, interleukin-2 and interleukin-X, which are also involved in the response to a classic thymus-dependent immunogen. Incorporation of lipid A has no qualitative effect on the dependence of liposomal immunogenicity on these lymphokines. For a number of years, we have been studying the immunogenic properties of liposomal model membranes that contain a novel class of synthetic lipid antigens. These are derivatives of phosphatidylethanolamine (PE) in which the amino function of this phospholipid has been substituted with various haptens. The prototype of such N-substituted PE derivatives is N-(2,4-dinitrophenyl-6-amino
Parental Reasoning, Denying Privileges, Yelling, and Spanking: Ethnic Differences and Associations with Child Externalizing Behavior

SYNOPSIS Objective. This study was designed to examine whether African American and European American mothers differ in their discipline use when reasoning, denying privileges, yelling, and spanking are considered simultaneously and whether there are ethnic group differences in how these four forms of discipline are associated with child externalizing behavior. Design . The authors used structural equation models to examine relations between children's externalizing behavior in Kindergarten (age 5 years), mothers’ discipline in Grades 1–3 (ages 6–8 years), and children's externalizing behavior in Grade 4 (age 9 years) in a sample of 585 mothers and children. Results . African American and European American mothers showed the same rank order frequency of reported use of each of the 4 forms of discipline, most frequently using reasoning, followed by yelling, denying privileges, and least frequently spanking. However, European American mothers more frequently reported using 3 of the 4 forms of discipline tha...
A Rab2 Mutant with Impaired GTPase Activity Stimulates Vesicle Formation from Pre-Golgi Intermediates

Rab2 immunolocalizes to pre-Golgi intermediates (vesicular-tubular clusters [VTCs]) that are the first site of segregation of anterograde- and retrograde-transported proteins and a major peripheral site for COPI recruitment. Our previous work showed that Rab2 Q65L (equivalent to Ras Q61L) inhibited endoplasmic reticulum (ER)-to-Golgi transport in vivo. In this study, the biochemical properties of Rab2 Q65L were analyzed. The mutant protein binds GDP and GTP and has a low GTP hydrolysis rate that suggests that Rab2 Q65L is predominantly in the GTP-bound–activated form. The purified protein arrests vesicular stomatitis virus glycoprotein transport from VTCs in an assay that reconstitutes ER-to-Golgi traffic. A quantitative binding assay was used to measure membrane binding of β-COP when incubated with the mutant. Unlike Rab2 that stimulates recruitment, Rab2 Q65L showed a dose-dependent decrease in membrane-associated β-COP when incubated with rapidly sedimenting membranes (ER, pre-Golgi, and Golgi). The mutant protein does not interfere with β-COP binding but stimulates the release of slowly sedimenting vesicles containing Rab2, β-COP, and p53/gp58 but lacking anterograde grade-directed cargo. To complement the biochemical results, we observed in a morphological assay that Rab2 Q65L caused vesiculation of VTCs that accumulated at 15°C. These data suggest that the Rab2 protein plays a role in the low-temperature–sensitive step that regulates membrane flow from VTCs to the Golgi complex and back to the ER.
Cost-effectiveness of perirectal surveillance cultures for controlling vancomycin-resistant Enterococcus.

BACKGROUND: Several hospitals opting not to use active surveillance cultures to identify carriers of vancomycin-resistant Enterococcus (VRE) have reported that adoption of other parts of the Centers for Disease Control and Prevention guideline for controlling VRE has had little to no impact. Because use of surveillance cultures and contact isolation controlled a large outbreak at this hospital, their costs were estimated for comparison with the excess costs of VRE bacteremias occurring at a higher rate at a hospital not employing these measures. SETTING: Two university hospitals. METHODS: Inpatients deemed high risk for VRE acquisition at this hospital underwent weekly perirectal surveillance cultures. Estimated costs of cultures and resulting isolation during a 2-year period were compared with the estimated excess costs of more frequent VRE bacteremias at another hospital of similar size and complexity not using surveillance cultures to control spread throughout the hospital. RESULTS: Of 54,052 patients admitted, 10,400 had perirectal swabs taken. Cultures and isolation cost an estimated $253,099. VRE culture positivity was limited to 193 (0.38%) and VRE bacteremia to 1 (0.002%) as compared with 29 bacteremias at the comparison hospital. The estimated attributable cost of VRE bacteremia at the comparison hospital of $761,320 exceeded the cost of the control program at this hospital by threefold. CONCLUSIONS: The excess costs of VRE bacteremia may justify the costs of preventive measures. The costs of VRE infections at other body sites, of deaths from untreatable infections, and of dissemination of genes for vancomycin resistance also help to justify the costs of implementing an effective control program (Infect Control Hosp Epidemiol 2002;23:429-435).
A Psychological, and Physiological of Three Groups of Older Adults As Related to Housing Needs and Norms1

A pre-occupancy survey was conducted of elderly persons whose names appeared on the waiting lists of two under-construction, independent living facilities for the aged. In addition to these two groups, a third group of elderly defined for the study was comprised of rural, isolated persons living in substandard housing. Assessments were made of: (a) housing quality, (b) physiological and health attributes, (c) group affiliation and social attitudes, (d) daily activity patterns, (e) dietary patterns, and (f) levels of morale, independent care, and self-maintenance. Results indicate widely differing housing norms, levels of housing quality (objective and self-rated), daily activity patterns, tenure patterns, and size of households across the three groups (WESLEY, EASE, and RURAL). Comparisons of health and physiological measures and dietary patterns indicate nonsignificant differences. A research sum mary provides insights into the administrative policy decisions that could act to ease the transition/relocat...
Behavioral Marriage Therapy: I. A Psychodynamic‐Systems Analysis and Critique

After briefly summarizing the major theoretical premises and treatment strategies of Behavioral Marriage Therapy (BMT), five major clusters of implicit assumptions in BMT are identified and critically examined: I. "The Rational Observing Ego Shall Conquer All"; II. "Behavior Should Not Mean, But Be"; III. "What's Sauce for the Goose is Sauce for the Gander"; IV. "Repression Is Good for Your Marital Mental Health"; V. "The Folly of the Therapist as Technician." Throughout this analysis, the conceptual and clinical limitations of a strictly or predominantly behavioral approach to couples therapy are described, and BMT is reconsidered in the light of object relations theory and communication theory perspectives on marital dysfunction and its treatment. Language: en
On Optimization of CSMA/CA based Wireless LANs: Part I - Impact of Exponential Backoff

In this paper, we consider optimization of CSMA/CA based wireless networks such as IEEE 802.11 Wireless LANs. A fundamental component of the MAC layer functionality in such networks is the binary exponential backoff (BEB) of contending nodes which serves as a means of arbitrating distributed channel access. In this paper, we show that the joint optimization of initial contention window (CWmin) and the number of backoff stages in BEB yields, interestingly, no additional gains over a simple CWmin optimization that is performed by considering that BEB is absent. Thus, BEB has negligible impact once CWmin is optimized. While this result holds only for an ideal WLAN, in the presence of channel errors, BEB penalizes performance even when CWmin is optimized. Finally, disabling BEB and optimizing CWmin not only improves short-term fairness significantly but it also stabilizes the system even when there are asymptotically large number of saturated users contending.
Performance Assessment And Comparison Of Learning In International Education: American Versus Jamaican Students Learning Outcomes

The purposes of the study were to assess and compare learning gained in a masters of science in human resources course entitled Management Communication and to measure performance through an objective pre-test and post-test examination with students pursuing their degree at a cluster site in Kingston, Jamaica, away from the main campus with those at the campus (Fort Lauderdale, Florida).These students were completing this graduate course in the summer term of 2005 and received traditional, face-to-face instruction in a classroom setting, with classes delivered in a weekend format during the term. Two different instructors taught the class using the same performance measure for comparison purposes. Student performance for the purpose of this study was defined as the score on the pre-test and on the final examination (post-test). Findings revealed that there was a statistically significant difference (alpha = .05) in the pre-test and post-test scores of students enrolled at the Kingston of Jamaica cluster and those at the Main Campus. Both groups had significant gains in the pre- and post-test examinations. Furthermore, the overall performance of students in Jamaica seems to be equivalent to the performance of students at the Main Campus when the classes are taught by two different faculty members who used the same final exam questions.
Object concept in deviant children.

Children manifesting deviant development were tested on a scale for visual pursuit and permanance of objects, using 1) preferred and 2) neutral objects. Subjects responded as if they had attained the sixth stage of object concept development, although consistency of performance varied between preferred and neutral objects.
URATE CRYSTAL INDUCED INFLAMMATION IN THE RAT: EVIDENCE FOR THE COMBINED ACTIONS OF KININS, HISTAMINE AND COMPONENTS OF COMPLEMENT

The inflammation produced by subplantar injection of sodium urate micro-crystals in the hindpaw of the rat was used as a model of gouty arthritis. Kinins are probably involved since carboxypeptidase B or soybean trypsin inhibitor partially (35%) blocked the edema. Serotonin does not participate since the edema was not prevented by methysergide or cyproheptadine. Histamine is apparently involved since many antihistaminics also partially (40%) suppressed this edema. Two antihistaminics, promethazine and tri-pelennamine, inhibited (75%) the edema as effectively as colchicine by mechanisms as yet not established. Treatment of rats with a combination of soybean trypsin inhibitor and a specific antihistaminic, triprolidine, inhibited the urate edema by 58-66%, which suggested that still another mediator was involved. Complement depletion of the rats also partially (30%) inhibited the edema. The combination of soybean trypsin inhibitor, triprolidine and complement depletion almost completely (80%) suppressed the...
Counseling Persons with Disabilities: Summary and Projections.

The author summarizes the findings of the other articles in this feature in terms of progress made during the last decade, as well as problems remaining. The author proposes several idealistic scenarios for counselors and other human development specialists to use as guidelines for future work with people who are disabled.
P02.54. Tools from the SPICER project for doing clinic-based research on integrative medicine and CAM

Purpose Non-intervention research using clinical records is difficult, both from the theoretical and practical standpoints. Progress on the former requires progress on the latter. Several techniques have been developed in the SPICER project to overcome the various practical problems encountered in research from electronic medical records (EMRs). This presentation will exhibit techniques that have been developed and appear to work well.
Effects of acute fluoride intoxication on rats.

SummaryYoung male rats (~200 g) were employed to study the distribution of parenterally administered inert and radiolabeled fluoride. Animals receiving 25 mg of fluoride/kg body weight did not live...
Central Nervous System Infections as a Cause of an Altered Mental Status? What is the Pathogen Growing in Your Central Nervous System?

There are several central nervous system (CNS) infections (meningitis, encephalitis, and brain abscess), any of which may present with an altered level of consciousness. Because CNS infections can have a devastating outcome, it is important to recognize the presence of a CNS infection and begin treatment as soon as possible because early appropriate therapy may, in some cases, limit morbidity and mortality.
Connecting recruitment of Antarctic krill and sea ice

We develop an age-structured model for two krill populations near the Antarctic Peninsula and estimate the relative recruitment events that reproduce observed trends in krill abundance and age structure. Estimates of recruitment in both regions show a nonlinear relationship between recruitment and sea ice area in the combined Bellingshausen and Amundsen Seas from the previous winter and spring, with large recruitment events occurring over a narrow range of ice area, and minimal recruitment otherwise. This finding may allow for an adaptive approach in which future catch limits are adjusted based on predictions of biomass. This result also suggests that the ecosystem may change dramatically once average ice area drops below the recruitment threshold.
Compactifications of F-theory on Calabi-Yau threefolds. (I)

Abstract We continue our study of compactifications of F-theory on Calabi-Yau threefolds. We gain more insight into F-theory duals of heterotic strings and provide a recipe for building F-theory duals for arbitrary heterotic compactifications on elliptically fibered manifolds. As a byproduct we find that string/string duality in six dimensions gets mapped to fiber/base exchange in F-theory. We also construct a number of new N = 1, d = 6 examples of F-theory vacua and study transitions among them. We find that some of these transition points correspond upon further compactification to 4 dimensions to transitions through analogues of Argyres-Douglas points of N = 2 moduli. A key idea in these transitions is the notion of classifying (0,4) fivebranes of heterotic strings.
Separation of convolutive mixtures using higher-order statistics

In this paper we propose a frequency domain approach for the separation of convolutive mixtures based on higher order statistics only. The system frequency response is first obtained up to a diagonal phase ambiguity matrix based on generalized eigen-decomposition of two cross-trispectrum matrices. Then the phase ambiguity is removed by exploiting different slices of the cross-trispectrum.
A statistical approach to specifying the off-axis EIRP spectral density in on-the-move satellite communications

The mobile very small aperture terminal is a new satellite terminal with applications in both military and commercial sectors. In some terrains, antenna pointing errors of these terminals may exceed satisfactory limits. In these terrains, since these errors may increase interference to neighboring satellites, it may be necessary to reduce the effective isotropic radiated power (EIRP) spectral density transmitted to satisfy the strict regulatory off-axis emission requirements. In this paper antenna pointing errors are considered as random variables and analysis carried out to characterize the probability that the EIRP spectral density exceeds its regulatory mask. This analysis can be used to specify a new mask for the off-axis EIRP spectral density for these terminals. The objective of this work is to develop a new ITU-R recommendation for mobile very small aperture terminals and this constitutes some of the contributions made to the ITU-R Working Party 4A Group.
Automatic detection of abnormal brain tissue in MR image

An auto-associative memory based method can be used to detect abnormal tissue in MR images automatically. An abnormal image vector is tested by application of an autocorrelation matrix that consists of normal image vectors. After the novelty filtering, the output corresponding to the abnormality is produced. The preliminary result and analysis showed that the method is feasible and effective.
Limited Flow Cytometry Panels on Bone Marrow Specimens Reduce Costs and Predict Negative Cytogenetics

Objectives: To determine the clinical and financial impact and predictive value of a limited flow cytometry strategy in the evaluation of bone marrow specimens. Methods: Consecutive bone marrow cases (n = 1,242) were reviewed following the independent, prospective application of two flow cytometry protocols: a limited marker strategy and a multimarker strategy. Combined morphologic and flow cytometry findings were also compared with cytogenetic results. Results: A limited flow cytometry strategy did not have a negative impact on disease detection and resulted in reduced utilization and cost. In addition, negative combined morphology and flow cytometry had a 98.4% predictive value for negative cytogenetics ( P < .001). Conclusions: Careful initial evaluation of bone marrow specimens can markedly reduce the costs of bone marrow examination and significantly reduce the need for flow cytometric and cytogenetic studies on these samples.