cssi/SciSciGPT-SciSciNet huggingface dataset:
Information and its impact on satisfaction among surgical patients

Abstract This study investigates the association between patient characteristics, reported problems with obtaining information and global evaluations of care among surgical patients. Using data from a large scale study of hospital care, a factor analysis of 30 information-relevant items was conducted with data from a sample of 3602 surgical patients; and correlation and multiple regression analyses were conducted to identify the relationships among information, patient characteristics and global evaluations of care. Path analysis was also used to determine the extent to which perceived control mediates the information–evaluation relationship. Four information factors were identified: surgical information, recovery information, general information and sensory information, and each was significantly related to global evaluations. Desire for involvement interacted with information received in determining patients’ evaluations; and partial support was found for perceived control as a mediator of the information–evaluation link. The data indicate that the relationship between information and evaluations of quality is generalizable across patients, conditions and hospitals; and should be defined more broadly to include that which is given by a variety of providers, to family, and about medications and home recovery. Desire for involvement and perceived control must also be considered in understanding the value and impact of information.
Undescended Testis Histology Correlation with Adult Hormone Levels and Semen Analysis

Purpose: Cryptorchidism has been associated with infertility. We hypothesize that a positive correlation exists between testicular histopathology at orchiopexy and future fertility potential in patients with cryptorchidism.Materials and Methods: Patients with cryptorchidism who underwent orchiopexy with bilateral testis biopsies were followed into adulthood. Testis histology was stratified into groups based on total germ cells per tubule and adult dark spermatogonia per tubule. After age 18 years, patients underwent hormonal testing and semen analysis. Mean semen analysis parameters and hormone levels were compared among histopathology groups.Results: A total of 91 patients with unilateral undescended testes and 19 with bilateral undescended testes had data for review. No significant differences in semen analysis parameters were seen among the germ cells per tubule groups. In unilateral undescended testis, sperm density and sperm count in the abnormal adult dark spermatogonia per tubule group remained wit...
On parallel hybrid guide bearings under combined sliding and small amplitude vibration with pressure-regulated lubricant supply

Abstract A linear pressure-regulated hybrid bearing model, featuring a laminar restrictor R∗ c that links the bearing recess to a constant supply pressure p∗ s is proposed for two-dimensional parallel guide bearings operating under combined translation and small amplitude transverse vibration. The model describes the fluid film constrained between a running saw blade and a saw guide or that in many other hybrid thrust bearing designs. The film pressure is generated by coupled hydrostatic and hydrodynamic lubrication. Unsteady fluid inertia, resulting from vibration, is modeled using the squeeze Reynolds number Res. The amplitude and phase of the dynamic bearing load W∗ i and the oscillating flowrate component Q∗ i are analytically predicted and the load-generating mechanisms are identified. Predictions by the current model converge to those of the constant volumetric lubricant supply rate model, discussed in an earlier paper (S.H. Chen and C.D. Mote, Jr., On parallel hybrid guide bearings under combined sliding and small amplitude vibration, ASME J. Tribol., 116 (1994) 127–132), when p∗ s → ∞ , R∗ c → ∞ and p∗ s /R∗ c → Q∗ = constant . Predictions by the current model reduce to those of a parallel hydrodynamic squeeze film model when R∗ c → 0.
Scalable Metering for an Affordable IT Cloud Service Management

As the cloud services journey through their life-cycle towards commodities, cloud service providers have to carefully choose the metering and rating tools and scale their infrastructure to effectively process the collected metering data. In this paper, we focus on the metering and rating aspects of the revenue management and their adaptability to business and operational changes. We design a framework for IT cloud service providers to scale their revenue systems in a cost-aware manner. The main idea is to dynamically use existing or newly provisioned SaaS VMs, instead of dedicated setups, for deploying the revenue management systems. At on-boarding of new customers, our framework performs off-line analysis to recommend appropriate revenue tools and their scalable distribution by predicting the need for resources based on historical usage. This allows the revenue management to adapt to the ever evolving business context. We evaluated our framework on a test bed of 20 physical machines that were used to deploy 12 VMs within Open Stack environment. Our analysis shows that service management related tasks can be offloaded to the existing VMs with at most 15% overhead in CPU utilization, 10% overhead for memory usage, and negligible overhead for I/O and network usage. By dynamically scaling the setup, we were able to reduce the metering data processing time by many folds without incurring any additional cost.
Heterosis of Agronomic Traits in Alfalfa

Increasing forage yields remains a top priority of most alfalfa (Medicago sativa L.) breeding programs. Studies of crosses between dormant to moderately dormant M. sativa subsp. sativa and M. sativa subsp. falcata suggest a heterotic pattern for yield exists between the two subspecies. However, other agronomic traits need to be considered in addition to yield, especially when trying to develop breeding material from nonadapted sources. The objective of this study was to quantify the agronomic performance of sativa × falcata crosses (SFC) in relation to sativa × sativa crosses (SSC) and falcata × falcata crosses (FFC). Nine elite sativa clones and five falcata clones were crossed in a diallel mating design. Progeny were space planted in 1998 at Nashua and Ames, IA. During the 1999 growing season, winter injury, spring regrowth, vigor, growth habit, maturity, height, midseason regrowth, and autumn regrowth were measured. The 14 parental genotypes differed for general combining ability (GCA) for all traits; specific combining ability (SCA) was noted for height, maturity, winter injury, and vigor. Sativa × sativa crosses were superior to FFC for all traits except winter injury and vigor. Sativa × falcata crosses per se had slightly increased agronomic performance over the expected mid-subspecies for many traits. Most of the hybrids are intermediate to SSC and FFC, suggesting potential agronomic weaknesses of falcata germplasm in a breeding program. Improving regrowth, height, and growth habit of falcata breeding material would likely be needed to create commercially successful sativa–falcata semihybrid cultivars.
HSV-2 DNA persistence in astrocytes of the trigeminal root entry zone: double labeling by in situ PCR and immunohistochemistry

A previous study using an in situ polymerase chain reaction (PCR) amplification method showed persistent herpes simplex virus type 2 (HSV-2) DNA sequences in brains of experimentally infected mice, particularly in cells of the pons near the trigeminal root entry zone. The present study was undertaken to identify the CNS cell type(s) that persistently harbor HSV DNA and to define the associated pathology. Tissue sections including the trigeminal root were immunoreacted to detect cellular antigens, then an HSV sequence was amplified in situ. During acute infection, the CNS portion of the trigeminal root was focally demyelinated and contained viral antigen and HSV DNA in glial cells. Following acute infection, no infectious virus or HSV antigen was detected. Demyelinated root lesions contained cells whose nuclei were similar in size to those of astrocytes and contained HSV-2 DNA by in situ PCR. With double labeling techniques, HSV DNA-containing nuclei were often associated with glial fibrillary acidic protein immunoreactivity, but not with that of neuron-specific enolase and only rarely with galactocerebroside or transferrin immunostaining. Thus, at least some of the cells containing persistent HSV DNA are astrocytes. Since HSV DNA is detected when no infectious virus can be isolated and no HSV antigen is found, we conclude that this astrocytic infection is non-productive. While in situ hybridization methods show HSV latency-associated transcript (LAT) RNA in neuronal nuclei during latent infections in trigeminal ganglia and, occasionally, in brain, we were unable to detect HSV-2 LAT RNA in astrocytes in these lesions, which suggests that persistent HSV infection of astrocytes may differ from neuronal latency. This is the first report of a persistent, non-productive HSV infection in CNS glia.
Infectious esophagitis following liver and renal transplantation

Upper gastrointestinal endoscopy was performed for the evaluation of infectious esophagitis in 19 consecutive subjects evaluated prospectively before orthotopic liver transplantation (OLTx), in a separate group of 27 subjects post-OLTx, and in 21 subjects following orthotopic renal transplantation (ORTx). None of the pre-OLTx patients had evidence of infectious esophagitis, whereas 11% of the post-OLTx and 24% of the post-ORTx patients had esophageal infections. Candidaesophagitis was found only in the post-ORTx patients, whereas cytomegalovirus and herpes simplex viral esophagitis were found in both the post-ORTx and post-OLTx patients. Dysphagia was associated with evidence of herpes simplex virus infection (P<0.001) and epigastric pain was associated with Candidainfection (P<0.001). No association between the administration of prednisone or the blood level of cyclosporine A and esophagitis was found. Finally, the use of standard low-dose mycostatin prophylaxis was not effective for prevention of Candidaesophagitis. Nonetheless the use of higher doses of mycostatin was therapeutic.
Optimization of cylindrical shells with compliant cores

Thin-walled, cylindrical structures are found extensively in both engineering components and in nature. The weight to load bearing ratio is a critical element of design of such structures in a variety of engineering applications, including space shuttle fuel tanks, aircraft fuselages, and offshore oil platforms. In nature, thin-walled cylindrical structures are often supported by a honeycomb- or foam-like cellular core, as for example, in plant stems, porcupine quills, or hedgehog spines. Previous studies have suggested that a compliant core increases the buckling resistance of a cylindrical shell over that of a hollow cylinder of the same weight. In this paper, we extend the linear-elastic buckling theory by coupling it with basic plasticity theory to provide a more comprehensive analysis of isotropic, cylindrical shells with compliant cores. We examine the optimal design of a thin-walled cylinder with a compliant core, of given radius and specified materials, for a prescribed load bearing capacity in axial compression. The analysis gives the values of the shell thickness, the core thickness, and the core density that maximize the load bearing capacity of the shell with a compliant core over an equivalent weight hollow shell. The analysis also identifies the optimum ratio of the core modulus to the shell modulus and is supported by a Lagrangian optimization technique. The analysis further discusses the selection of materials in the design of a cylinder with a compliant core, identifying the most suitable material combinations. The performance of a cylinder with a compliant core is compared with competing designs (optimized hat-stiffened shell and optimized sandwich-wall shell). Finally, the challenges associated with achieving the optimal design in practice are discussed, and the potential for practical implementation is explored.
Arc-smoothness in hyperspaces

Abstract Let X be a metric continuum and 2 x ( C ( X )) denote the hyperspace of closed subsets (subcontinua) of X . The concept of arc-smoothness, which is a special type of contractibility, is investigated in 2 x and C ( X ). Results are obtained about hyperspaces of locally connected continua, about continua for which C ( X ) and the cone over X are homeomorphic, about Whitney levels in C ( X ), and about hyperspaces of hereditarily indecomposable continua. Some examples are given and several natural questions are raised.
Studies on the mode of action of calciferol VI: Effect of 1,25-dihydroxy-vitamin D3 on RNA synthesis in the intestinal mucosa

Abstract Vitamin D (calciferol) has been postulated [A.W. Norman, Science 149 , 184 1965] to mediate its physiological effects via an inductive process which produces new RNA and proteins. This was tested directly by studying the effect of the biologically active form of calciferol, 1,25-dihydroxycholecalciferol to stimulate in vivo the pulse labeling of intestinal mucosa by 3 H uridine. The maximum stimulation of RNA labeling occurs 6 hours after the intracardial administration of 325 pmoles of 1,25-dihydroxy-cholecalciferol: the first effects were apparent within 3–4 hours. Also, actinomycin D was shown to block both 1,25-dihydroxy-cholecalciferol stimulated Ca 2+ transport and RNA synthesis. The chronology of events occurring after administration of 1,25-dihydroxy-cholecalciferol suggest that the primary biochemical response of intestinal mucosa to 1,25-dihydroxy-cholecalciferol is probably the initiation of RNA and protein synthesis.
The combined use of digital computers and coherent optics in image processing

Many image processing problems, including the restoration of atmospherically degraded images , can be benefited by the combined use of digital computers and coherent optical equipment, preferably in real time. Various questions then arise: What types of operations can better be done on a digital computer than by coherent optics, and vice versa? How can one transfer data quickly between a digital computer and coherent optical equipment? In this paper, we first briefly review and then compare digital computer and coherent optical image processing techniques to indicate their relative merits and faults. Then, we propose schemes for data transfer between digital computers and coherent optical equipment, and discuss the hardware available for carrying out these schemes. Finally, we look into the future and describe some desirable features of large image processing centers.© (1967) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
A Pseudo-Rigid-Body Model for Large Deflections of Fixed-Clamped Carbon Nanotubes

Carbon nanotubes (CNTs) may be used to create nanoscale compliant mechanisms that possess large ranges of motion relative to their device size. Many macroscale compliant mechanisms contain compliant elements that are subjected to fixed-clamped boundary conditions, indicating that they may be of value in nanoscale design. The combination of boundary conditions and large strains yield deformations at the tube ends and strain stiffening along the length of the tube, which are not observed in macroscale analogs. The large-deflection behavior of a fixedclamped CNT is not well-predicted by macroscale large-deflection beam bending models or truss models. Herein, we show that a pseudo-rigid-body model may be adapted to capture the strain stiffening behavior and, thereby, predict a CNT’s fixed-clamped behavior with less than 3% error from molecular simulations. The resulting pseudo-rigid-body model may be used to set initial design parameters for CNT-based compliant mechanisms. This removes the need for iterative, time-intensive molecular simulations during initial design phases. DOI: 10.1115/1.4001726
Capitalism and US policy at the Mexican border

Does US policy at the Mexican border—heavily weighted toward immigration and drug law enforcement—help the capitalist system function in North America, and if so, how? And if not, what are the most likely drivers of such policies, and how do they interact with the capitalist context? Four topics are examined: inequalities of rights to border crossing into the United States from Mexico, and the role of such unequal mobility in the maintenance of various privileges in North America; a puzzle in capitalist–functionalist border policy–underinvestment in ports of entry compared to enforcement between such ports; enforcement against unauthorized migrants seen both as labor control and discriminatory politics; and border enforcement and militarization as a system of regional repression and control, addressed at the rapidly growing and important US–Mexico border region. The relationship between US border policies and the functional needs of capitalism is complex, not simple; the article rejects a perfect system view in favor of a richer view of capitalism as filled with contradictory social impulses and political outcomes, shaped in broad contexts of class relations and capital accumulation. The wider context of this essay is the question of how the territorial nation-state relates to capitalism, two fundamental features of our era. Some preliminary thoughts on that question are broached in the conclusion.
Longevity Among Hunter‐ Gatherers: A Cross‐Cultural Examination

Post-reproductive longevity is a robust feature of human life and not only a recent phenomenon caused by improvements in sanitation, public health, and medical advances. We argue for an adaptive life span of 68-78 years for modern Homo sapiens based on our analysis of mortality profiles obtained from small-scale hunter-gatherer and horticultural populations from around the world. We compare patterns of survivorship across the life span, rates of senescence, modal ages at adult death, and causes of death. We attempt to reconcile our results with those derived from paleodemographic studies that characterize prehistoric human lives as “nasty, brutish, and short,” and with observations of recent acculturation among contemporary subsistence populations. We integrate information on age-specific dependency and resource production to help explain the adaptive utility of longevity in humans from an evolutionary perspective.
Assessment of Free Dye in Solutions of Dual-Labeled Antibody Conjugates for In Vivo Molecular Imaging

Purpose Recent preclinical and clinical studies show that dyes that excite and fluoresce in the near-infrared range may be used for tracking and detecting disease targets in vivo. A method for quantifying free dye molecules in antibody conjugate preparations is required for agent batch release and for translation into the clinic.
Wave-packet evolution and quantization

A general relationship is established between wave-packet evolution and quantization in classically integrable systems. Because of wave-packet spreading, one cannot simply take the Fourier transform of the time evolution of a wave-packet. Instead, one must propagate the wave-packet using the actions as Hamiltonians. The energy eigenvalues which result are the Einstein-Brillouin-Keller values, and new forms for the eigenfunctions appear. These are free of caustic singularities, and represent averages of wave packets over the invariant torus.
Forces and pressures on the horse’s back during bareback riding

The objectives of this study were to measure forces and pressure profiles when riding with a conventional saddle compared to bareback riding. An electronic pressure mat was used to compare contact area, mean total force and pressure variables for one rider riding seven horses at sitting trot with a conventional saddle or bareback. The use of a saddle was associated with a larger contact area and higher mean total force compared with the bareback condition. Mass normalized mean total force for bareback riding was lower than expected based on the rider’s body mass, suggesting that shear forces exerted by the rider’s thighs were not being registered by the pressure mat. In spite of the lower total force, the bareback condition was associated with higher average pressure, higher maximal pressure and larger area with mean pressure >11 kPa. Focal pressure concentrations were present beneath the rider’s ischial tuberosities in the area of the horse’s epaxial muscles when riding bareback but not when using a saddle. It was concluded that bareback riding was associated with focal pressure concentrations that may increase the risk of pressure-induced injury to the horse’s epaxial musculature. The findings also emphasized that researchers should remain cognizant of shear forces, which may not be registered by the pressure mat, but may contribute to the effects of riding on the horse’s back.
EFFECT OF DOSAGE ON PLATEAUING IN ADULT FEMALE NORWAY RATS RECEIVING A GROWTH HORMONE CONTAINING PITUITARY EXTRACT1

Nine groups of adult female Long-Evans rats, containing 8 to 10 rats each, were given daily injections of a growth hormone-containing extract of bovine anterior pituitaries at dose levels representing 1.28 to 12.8 mg. of growth hormone/ kg, /day. In each group there was initially a major resumption of growth, followed by establishment of a new growth plateau at a greater size. Group comparison of the weight gain during the initial and terminal 20 day periods gave t ratios ranging from 6.6 to 16.4 with p values ranging fron 2×10−7 to less than 10−10. The time required for growth cessation ranged from 16 days at the lowest dose level to 200 days at the highest dose level. Weight gained prior to plateauing ranged from 21.6 ±1.7 grams at the lowest dose level to 350.0 ± 14.4 grams (mean ± std. error) at the highest dose level. The length increments were relatively greater at low dose levels.
Fetal pulse oximetry: Correlation between oxygen desaturation, duration, and frequency and neonatal outcomes☆☆☆

Abstract Objective: The purpose of this study was to identify the threshold of fetal arterial oxyhemoglobin saturation that predicts neonatal acidosis and adverse outcomes. Study Design: Fetal oxygen saturation data from a published randomized controlled trial of fetal pulse oximetry were evaluated in relation to the number and duration of low fetal oxygen saturation episodes and neonatal outcomes. Fetal oxygen saturation episodes (epochs) of at least 10-second duration were categorized into the following groups: (1) 30%. Results: One hundred seventy-four fetal heart rate tracings were identified. An analysis of mean umbilical artery pH revealed a significant difference between groups 1 and 3 compared with the control subjects. The incidence of adverse neonatal outcome was significantly greater when the number of epochs exceeded 10. An analysis of the duration of fetal oxygen saturation of Conclusion: This study confirms previous findings that fetal oxygen saturation of 10 epochs of
Samuel Van Valkenburg: politics and regional geography

Abstract Samuel Van Valkenburg was a prominent geographer working in the United States whose career spanned the period from the Treaty of Versailles to the Cold War. He is best known for his geopolitical writings of the pre World War II period, fashioning one of the few American-oriented geopolitical theories comparable to those of Mackinder or Hausofer. This paper traces the evolution of his work from geopolitical theory to war-time propaganda to post-war mainstream political geography. Central to this analysis is a comparison of his personal history with that of the general field of political geography. Special effort is made to inform current interest on the status of ‘empiricist’ political geography as well as on the history of the ‘political geography v. geopolitics’ debate. The conclusion drawn is that neither geopolitics nor political geography can be understood in relation to one another and the true comparison is and always has been between these and regional geography.
THE BIFURCATION STRUCTURE OF THE HOLLING--TANNER MODEL FOR PREDATOR-PREY INTERACTIONS USING TWO-TIMING

The Holling--Tanner model for predator-prey systems has two Hopf bifurcation points for certain parameters. The dependence of the environmental parameters on the underlying bifurcation structure is uncovered using two-timing. Emphasis is on how the bifurcation diagram changes as the Hopf bifurcation points separate. Two degenerate cases require a modification of conventional two-timing. When the two Hopf bifurcation points nearly coalesce, the two stable periodic solution branches are shown to be connected. As a ratio of linear growth rates varies, the Hopf bifurcation points separate further and one limit cycle becomes unstable. This situation can correspond to an outbreak in populations. The modified two-timing analysis analytically captures the unstable and stable limit cycles of the new branch.
Temporal Patterns in Glycolate-Utilizing Bacterial Community Composition Correlate with Phytoplankton Population Dynamics in Humic Lakes

Previous observations of correlated community dynamics between phytoplankton and bacteria in lakes indicate that phytoplankton populations may influence bacterial community structure. To investigate the possibility that bacterial use of phytoplankton exudates contributes to observed patterns of community change, we characterized the diversity and dynamics of heterotrophic bacterioplankton with genetic potential to use glycolate, a photorespiration-specific exudate, in five lakes over a 15-week period. Culture-independent approaches were used to track different bacterial phylotypes represented by DNA sequence variation in the functional gene glycolate oxidase subunit D (glcD). glcD gene sequences from freshwater bacteria exhibited broad phylogenetic diversity, including sequences representing the Alpha-, Beta-, and Gammaproteobacteria, Actinobacteria, Bacteroidetes, Firmicutes, and Verrucomicrobia. The majority of glcD gene sequences were betaproteobacterial, with 48% of the sequences clustering with the glcD gene from the cosmopolitan freshwater species Polynucleobacter necessarius. Terminal restriction fragment length polymorphism fingerprinting of the glcD gene revealed changes in glycolate-utilizing assemblages over time. An average of 39% of within-lake temporal variation in glycolate-utilizing assemblages across five lakes was explained by phytoplankton community composition and dynamics. The interaction between phytoplankton populations and the environment explained an additional 17% of variation on average. These observations offer new insight into the diversity and temporal dynamics of freshwater bacteria with genetic potential to use glycolate and support the hypothesis that algal exudates influence the structure of bacterial communities.
Comparative Expression of Adult and Fetal V Gene Repertoires

A hallmark of the immune system is the extraordinary diversity associated with antibodies. This is made possible by a series of genetic rearrangements involving variable region gene segments. Considerable detail is known about these genetic mechanisms except for the enzymatic machinery involved. An important question in studies of the generation of diversity is whether V genes are selected for rearrangement mainly in a random manner or selected by particular developmental rules. Past studies have indicated that the acquisition of fetal and neonatal specificity repertoires is a nonrandom process. In this report, we review our studies that directly compare the adult and fetal/neonatal V gene repertoires. The evidence suggests that the adult repertoire is more diverse with indications of a random use of VH gene families. However, whether V genes are indeed randomly used in the adult remains to be clarified at the VH gene member level. The fetal repertoire, on the other hand, appears nonrandom in V gene usage...
Matrix-isolation study of the decomposition of CF3NNCF3 by photons and by excited rare-gas atom bombardment at energies between 4.9 and 16.8 eV

Abstract When dilute solid solutions of CF 3 NNCF 3 in argon at 14 K are irradiated by the full light of a medium-pressure mercury arc, no net photolysis occurs, suggesting that the primary photodecomposition products, CF 3 N 2 + CF 3 , undergo cage recombination. On 122 nm photolysis, cage recombination leads instead to the appearance of prominent infrared absorption of C 2 F 6 , suggesting an initial photodecomposition process to form 2 CF 3 + N 2 . Prominent infrared absorptions of CF 4 and CF 2 were shown to result from the photodecomposition of C 2 F 6 . Argon-resonance radiation does not penetrate solid Ar:CF 3 NNCF 3 deposits, but when photolysis is conducted concurrently with deposition a high yield of CF 3 is isolated in the argon matrix. Circumvention of the cage effect in this system is attributed to the large amount of excess energy with which the photofragments are formed and to a very short lifetime for the excited electronic state of CF 3 NNCF 3 before dissociation. Even higher yields of CF 3 are formed when the Ar:CF 3 NNCF 3 sample is codeposited with a beam of argon atoms excited in a microwave discharge. The effects of concentration and experimental configuration on the product yield are discussed. When the sample is codeposited with a beam of excited neon atoms (16.6–16.8 eV); the most prominent product absorption is that of CF 3 + , with relatively weak absorptions of CF 3 , suggesting that at this energy the primary photodecomposition process leads to the formation of CF 3 + CF 3 + + N 2 + e.
Decay-accelerating Factor Prevents Acute Humoral Rejection Induced by Low Levels of Anti-αgal Natural Antibodies

Background Hyperacute and delayed vascular rejection due to natural antibodies (NAb) present major obstacles in pig-to-primate xenotransplantation. Although "supraphysiologic" expression of human complement regulatory proteins (CRPs) can prevent hyperacute rejection in discordant xenogenic recipients, their physiologic role in the homologous setting is undefined. We have evaluated the effect of the absence of decay-accelerating factor (DAF) on cardiac allograft rejection in the presence of different levels of antidonor antibodies (Ab). Methods DAF1-deficient (DAF KO; B6129F2 H-2) mice were used as heart graft donors to alpha1,3-galactosyltransferase deficient (GalT KO; B6, H-2) recipients. Heterotopic heart grafting was performed with or without presensitization. Graft survival, histology, and anti-alphaGal Ab levels were monitored. Results DAF knockout (KO) but not wild-type (WT) grafts showed hyperacute or acute humoral rejection in nonsensitized GalT KO mice with low levels of anti-alphaGal IgM NAb. However, humoral rejection of both DAF KO and DAF WT donor grafts occurred in presensitized GalT KO recipients. Conclusions The expression of DAF prevents hyperacute rejection in mice with low titers of anti-alphaGal antibody. These studies demonstrate the physiologic role of DAF in preventing humoral rejection in the presence of low levels of NAb and have implications for transplantation of discordant vascularized xenografts.
The C57L/J mouse strain as a model for extrapulmonary effects of ozone exposure.

It is not unusual for animal species including primates to differ from humans in response to toxic substances (COULSTON 1966) and a necessary step that must not be overlooked by a toxicologist is to determine whether some human data are already available and base the selection of animal species on a similar metabolic and physiologic response (STARA and KELLO 1979). The purpose of this study was to compare the similarity of the male C57L/J mouse strain to adult male humans in their response to changes in blood and serum characteristics from exposure to low levels of ozone. A similarity in metabolic and physiologic response would indicate the value of such a model in predicting human health effects.
Analysis of Antagonist Stiffness for Nested Compliant Mechanisms in Agonist-Antagonist Arrangements

Members of the animal kingdom produce motion by muscle contraction. Biological muscle can be viewed as a unidirectional actuator. To achieve bidirectional motion, each muscle has a corresponding antagonist muscle whose contraction produces motion in the opposite direction. This gives biological systems the unique ability to modulate the stiffness of a joint, which is important when interacting with the environment. Certain bio-inspired robotic systems incorporate antagonistic pairs in an attempt to produce similar desirable properties. The cellular actuator employs nested compliant mechanisms to produce human-scale motion from piezoelectric stack actuators, which on their own have a small displacement. The expression for the stiffness of the actuator composed of these mechanisms takes the form of a continued fraction, which results from the nested structure. In this way, the stiffness can be easily approximated to a desired degree of accuracy by considering only the outermost mechanisms.Copyright © 2011 by ASME
Synthesis and secretion of immunoreactive methionine-enkephalin from rabbit reproductive tissues in vivo and in vitro.

The expression of the proenkephalin gene has been demonstrated in the reproductive tissues of several animal species. The objectives of the experiments reported here were to (a) examine the presence of immunoreactive methionine-enkephalin (ir- MENK) in rabbit ovary, oviduct, and uterus and in a rabbit endometrial cell line (HRE-t-19), (b) characterize ir-MENK biochem- ically, (c) investigate the effect of eCG + hCG treatment on the synthesis and secretion of ir-MENK in vivo, and (d) study the effect of K depolarization on the secretion of ir-MENK from HRE-H9 cells. Uterine fluid was collected by flushing the uterine lumen with saline. Reproductive tissues and HREH9 cells were extracted with 0.1 N acetic acid. Both the uterine fluid and extracts of uterus, ovary, oviduct, and HRE-H9 cells exhibited inhibition curves parallel to that of authentic MENK in the MENK RIA system. Sephadex G- 15 gel filtration profiles indicated that in the extracts of rabbit uterus and HRE-H9 cells, most ir-MENK co.eluted with standard MENK, with a minor portion eluting near the void volume (V0). Reverse.phase-HPLC (RP.HPLC) profiles showed a major peak coinciding with standard MENK, plus a minor peak of highly hydrophiic ir-MENK. The effect of eCG + hCG treatment was studied by i.m. injection of eCG (150 lU), followed by i.v. injection of hCG (75 IU) 4 days later. Ir-MENK concentration in the uteri and ovaries was significantly (p < 0.05) increased (9.06 ± 1.89 and 2.05 ± 0.32 ng/mg protein, respectively), compared to control levels (2.31 ± 0.86 and 0.24 ± 0.77). Treatment with eCG + hCG did not cause significant changes in ir-MENK concentrations in oviducts and uterine fluids. Secretion of ir- MENK from HRE-H9 cells increased due to depolarization by 15 mM of KCI after 1 h of incubation and reached its maximum level after 4 h. These results showed that ir-MENK is present in rabbit uterus, ovary, oviduct, and uterine fluid and also in HRE. H9 cells. The synthesis of ir-MENK in the ovary and uterus may be influenced by ovarian steroids, Secretion of ir'MENK from HRE-H9 cells can be stimulated by depolarization of cells with KCI.
Root responses and nitrogen acquisition by Artemisia tridentata and Agropyron desertorum following small summer rainfall events

Resources in the Great Basin of western North America often occur in pulses, and plant species must rapidly respond to temporary increases in water and nutrients during the growing season. A field study was conducted to evaluate belowground responses of Artemisia tridentata and Agropyron desertorum, common Great Basin shrub and grass species, respectively, to simulated 5-mm (typical summer rain) and 15-mm (large summer rain) summer rainfall events. The simulated rainfall was labeled with K15NO3 so that timing of plant nitrogen uptake could be monitored. In addition, soil NH4+ and NO3− concentrations and physiological uptake capacities for NO3− and NH4+were determined before and after the rainfall events. Root growth in the top 15 cm of soil was monitored using a minirhizotron system. Surprisingly, there was no difference in the amount of labeled N acquired in response to the two rainfall amounts by either species during the 7-day sample period. However, there were differences between species in the timing of labeled N uptake. The N label was detected in aboveground tissue of Agropyron within 1 h of the simulated rainfall events, but not until 24 h after the rainfall in Artemisia. For both Agropyron and Artemisia, root uptake capacity was similarly affected by the 5-mm and 15-mm rainfall. There was, however, a greater increase in uptake capacity for NH4+ than for NO3–, and the 15-mm event resulted in a longer response. No root growth occurred in either species in response to either rainfall event during this 8-day period. The results of this study indicate that these species are capable of utilizing nitrogen pulses following even small summer rainfall events during the most stressful period of the summer and further emphasize the importance of small precipitation events in arid systems.
Demonstration of COSAK static analysis tools

A software vulnerability is a fault in the specification, implementation, or configuration of a software system whose execution can violate an explicit or implicit security policy. Users typically focus on the functionality of software rather than its security posture. Hence, vulnerabilities often escape their attention until the software is exploited by specially written malicious code. Code auditing is one solution which has been tried with some success in systems such as the OpenBSD operating system. Code audits involve the review of source code by experts in search of vulnerabilities. These audits are reoccurring, namely each revision of the software requires reexamination, and expensive because code audits are labor intensive. Auditors would benefit from a tool which enables them to focus their attention on high-risk areas, thus reducing the amount of code that needs to be audited. The article shows how the tools developed at Drexel University can be used to direct the attention of code auditors to those components that have a high likelihood of being vulnerable.
Measuring ectomycorrhizal fungal dispersal: macroecological patterns driven by microscopic propagules.

Dispersal plays a prominent role in most conceptual models of community assembly. However, direct measurement of dispersal across a whole community is difficult at ecologically relevant spatial scales. For cryptic organisms, such as fungi and bacteria, the scale and importance of dispersal limitation has become a major point of debate. We use an experimental island biogeographic approach to measure the effects of dispersal limitation on the ecological dynamics of an important group of plant symbionts, ectomycorrhizal fungi. We manipulated the isolation of uncolonized host seedlings across a natural landscape and used a range of molecular techniques to measure the dispersal rates of ectomycorrhizal propagules and host colonization. Some species were prolific dispersers, producing annual spore loads on the order of trillions of spores per km 2 . However, fungal propagules reaching host seedlings decreased rapidly with increasing distance from potential spore sources, causing a concomitant reduction in ectomycorrhizal species richness, host colonization and host biomass. There were also strong differences in dispersal ability across species, which correlated well with the predictable composition of ectomycorrhizal communities associated with establishing pine forest. The use of molecular tools to measure whole community dispersal provides a direct confirmation for a key mechanism underlying island biogeography theory and has the potential to make microbial systems a model for understanding the role of dispersal in ecological theory.
Origin of adult male mediastinal germ-cell tumours

Abstract The origin of primary extragonadal germ-cell tumours, especially mediastinal and pineal germ-cell tumours in adult males remains uncertain, although the predominant view is that they originate in misplaced primordial germ cells retained in extra-gonadal sites, in contrast to gonadal germ-cell tumours which are considered to arise in premeiotic spermatocytes. We hypothesised that if mediastinal germ-cell tumours and gonadal germ-cell tumours were derived from precursor cells in different developmental states and in different cellular environments, non-random genetic changes in the two groups would be significantly different. To test this hypothesis, we compared non-random chromosomal abnormalities in mediastinal germ-cell tumours with those in gonadal germ-cell tumours. Our results show that although the two groups differed in the composition of histological subsets, their non-random chromosomal changes were essentially the same. These data suggest gonadal origin of all germ-cell tumours with occasional migration of precursors early in development to extragonadal sites to become established as primary extragonadal germ-cell tumours. Based on a review of cytogenetic data on carcinoma in situ, primary mediastinal and gonodal germ-cell tumours, embryonal migration of primordial germ-cells, and meiotic behaviour of spermatocytes, a model of origin of all germ-cell tumours in males is suggested.
A Primer on Bootstrap Factor Analysis as Applied to Health Studies Research

Objectives: To demonstrate how the bootstrap method could be conducted in exploratory factor analysis (EFA) with a syntax written in SPSS. Methods: The data obtained from the Texas Childhood Obesity Prevention Policy Evaluation project (T-COPPE project) were used for illustration. A 5-step procedure to conduct bootstrap factor analysis (BFA) was introduced: (1) conduct principal component analysis, (2) create the target matrix, (3) resample with replacement, (4) conduct EFA and Procrustes rotation, and (5) calculate BFA results. Results: Results of the illustrated BFA example indicated that the 15 variables from this study were stable across the resamples. Conclusions: The bootstrap method, when applied in EFA for health-related research, is a particularly powerful internal replicability analysis.
Toxic elements in tobacco and in cigarette smoke: inflammation and sensitization

Biochemically and pathologically, there is strong evidence for both atopic and nonatopic airway sensitization, hyperresponsiveness, and inflammation as a consequence of exposure to tobacco mainstream or sidestream smoke particulate. There is growing evidence for the relation between exposure to mainstream and sidestream smoke and diseases resulting from reactive oxidant challenge and inflammation directly as a consequence of the combined activity of neutrophils, macrophages, dendritic cells, eosinophils, basophils, as a humoral immunological consequence of sensitization, and that the metal components of the particulate play a role in adjuvant effects. As an end consequence, carcinogenicity is a known outcome of chronic inflammation. Smokeless tobacco has been evaluated by the IARC as a group 1 carcinogen. Of the many harmful constituents in smokeless tobacco, oral tissue metallothionein gradients suggest that metals contribute to the toxicity from smokeless tobacco use and possibly sensitization. This work reviews and examines work on probable contributions of toxic metals from tobacco and smoke to pathology observed as a consequence of smoking and the use of smokeless tobacco.
Understanding the role of physician attire on patient perceptions: a systematic review of the literature— targeting attire to improve likelihood of rapport (TAILOR) investigators

Objectives Despite a growing body of literature, uncertainty regarding the influence of physician dress on patients’ perceptions exists. Therefore, we performed a systematic review to examine the influence of physician attire on patient perceptions including trust, satisfaction and confidence. Setting, participants, interventions and outcomes We searched MEDLINE, Embase, Biosis Previews and Conference Papers Index. Studies that: (1) involved participants ≥18 years of age; (2) evaluated physician attire; and (3) reported patient perceptions related to attire were included. Two authors determined study eligibility. Studies were categorised by country of origin, clinical discipline (eg, internal medicine, surgery), context (inpatient vs outpatient) and occurrence of a clinical encounter when soliciting opinions regarding attire. Studies were assessed using the Downs and Black Scale risk of bias scale. Owing to clinical and methodological heterogeneity, meta-analyses were not attempted. Results Of 1040 citations, 30 studies involving 11 533 patients met eligibility criteria. Included studies featured patients from 14 countries. General medicine, procedural (eg, general surgery and obstetrics), clinic, emergency departments and hospital settings were represented. Preferences or positive influence of physician attire on patient perceptions were reported in 21 of the 30 studies (70%). Formal attire and white coats with other attire not specified was preferred in 18 of 30 studies (60%). Preference for formal attire and white coats was more prevalent among older patients and studies conducted in Europe and Asia. Four of seven studies involving procedural specialties reported either no preference for attire or a preference for scrubs; four of five studies in intensive care and emergency settings also found no attire preference. Only 3 of 12 studies that surveyed patients after a clinical encounter concluded that attire influenced patient perceptions. Conclusions Although patients often prefer formal physician attire, perceptions of attire are influenced by age, locale, setting and context of care. Policy-based interventions that target such factors appear necessary.
The new "normal" blood pressure: what are the implications for family medicine?

Background: In 2003, the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure redefined normal blood pressure (BP) as less than 120/80 mm Hg and added the category of prehypertension, recommending that such patients receive counseling on lifestyle modifications. Based on population data, 41.8% of US adults have normal BP, 31% have prehypertension, and the remainder has hypertension. These percentages may not reflect the proportions seen in family medicine practices. The purposes of this study were to describe the proportion of adults in a family medicine practice with normal BP and the proportions with prehypertension and hypertension and to examine associations with having normal BP. Methods: Records of 633 nonpregnant adults from a large family medicine clinic were reviewed for demographic and BP information. Proportions of subjects in each BP category (normal, prehypertension, or hypertension) were determined. Characteristics associated with normal BP were examined using χ2 tests and logistic regression. Results: Nearly 80% of adults in this population had prehypertension or hypertension. Subjects more likely to have normal BP were young, female, white, and not overweight/obese. Almost 60% of subjects had documented hypertension, were receiving antihypertensive medications, or had a BP on the day of visit ≥140/90 mm Hg. Over 20% had prehypertension. Conclusion: The proportion of adult family medicine patients with normal BP is low. Counseling 20% of adult patients about prehypertension while continuing to strive to improve BP control for the 60% of patients with hypertension could pose a new challenge to clinicians working in family medicine offices.