cssi/SciSciGPT-SciSciNet huggingface dataset:
Transformation of meta-stable calcium silicate hydrates to tobermorite: reaction kinetics and molecular structure from XRD and NMR spectroscopy

Understanding the integrity of well-bore systems that are lined with Portland-based cements is critical to the successful storage of sequestered CO2 in gas and oil reservoirs. As a first step, we investigate reaction rates and mechanistic pathways for cement mineral growth in the absence of CO2 by coupling water chemistry with XRD and NMR spectroscopic data. We find that semi-crystalline calcium (alumino-)silicate hydrate (Al-CSH) forms as a precursor solid to the cement mineral tobermorite. Rate constants for tobermorite growth were found to be k = 0.6 (± 0.1) × 10-5 s-1 for a solution:solid of 10:1 and 1.6 (± 0.8) × 10-4 s-1 for a solution:solid of 5:1 (batch mode; T = 150°C). This data indicates that reaction rates for tobermorite growth are faster when the solution volume is reduced by half, suggesting that rates are dependent on solution saturation and that the Gibbs free energy is the reaction driver. However, calculated solution saturation indexes for Al-CSH and tobermorite differ by less than one log unit, which is within the measured uncertainty. Based on this data, we consider both heterogeneous nucleation as the thermodynamic driver and internal restructuring as possible mechanistic pathways for growth. We also use NMR spectroscopy to characterize the site symmetry and bonding environment of Al and Si in a reacted tobermorite sample. We find two [4]Al coordination structures at δ iso = 59.9 ppm and 66.3 ppm with quadrupolar product parameters (PQ) of 0.21 MHz and 0.10 MHz (± 0.08) from 27Al 3Q-MAS NMR and speculate on the Al occupancy of framework sites by probing the protonation environment of Al metal centers using 27Al{1H}CP-MAS NMR.
Mitochondrial outer membrane permeability change and hypersensitivity to digitonin early in staurosporine-induced apoptosis.

We have shown here that the apoptosis inducer staurosporine causes an early decrease in the endogenous respiration rate in intact 143B.TK− cells. On the other hand, the activity of cytochrome c oxidase is unchanged for the first 8 h after staurosporine treatment, as determined by oxygen consumption measurements in intact cells. The decrease in the endogenous respiration rate precedes the release of cytochromec from mitochondria. Moreover, we have ruled out caspases, permeability transition, and protein kinase C inhibition as being responsible for the decrease in respiration rate. Furthermore, overexpression of the gene for Bcl-2 does not prevent the decrease in respiration rate. The last finding suggests that Bcl-2 acts downstream of the perturbation in respiration. The evidence of normal enzymatic activities of complex I and complex III in staurosporine-treated 143B.TK− osteosarcoma cells indicates that the cause of the respiration decrease is probably an alteration in the permeability of the outer mitochondrial membrane. Presumably, the voltage-dependent anion channel closes, thereby preventing ADP and oxidizable substrates from being taken up into mitochondria. This interpretation was confirmed by another surprising finding, namely that, in staurosporine-treated 143B.TK− cells permeabilized with digitonin at a concentration not affecting the mitochondrial membranes in naive cells, the outer mitochondrial membrane loses its integrity; this leads to a reversal of its impermeability to exogenous substrates. The loss of outer membrane integrity leads also to a massive premature release of cytochromec from mitochondria. Most significantly, Bcl-2 overexpression prevents the staurosporine-induced hypersensitivity of the outer membrane to digitonin. Our experiments have thus revealed early changes in the outer mitochondrial membrane, which take place long before cytochrome c is released from mitochondria in intact cells.
Reared microgastrine wasps (Hymenoptera: Braconidae) from Yanayacu Biological Station and environs (Napo Province, Ecuador): diversity and host specialization.

The microgastrine braconid wasps recovered up through 2007 by the NSF-sponsored rearing project “Caterpillars and Parasitoids of the Eastern Andes in Ecuador” are summarized in terms of their host specialization and faunistic uniqueness. Two hundred fifty eight rearings of caterpillars resulted in records of Microgastrinae, distributed among 14 genera (Apanteles Forster, Choeras Mason, Cotesia Cameron, Diolcogaster Ashmead, Distatrix Mason, Dolichogenidea Viereck, Exix Mason, Glyptapanteles Ashmead, Hypomicrogaster Ashmead, Papanteles Mason, Parapanteles Ashmead, Protapanteles Ashmead, Sathon Mason and Venanus Mason). Eleven records of hyperparasitoids of Microgastrinae are also summarized; Mesochorus Gravenhorst (Ichneumonidae) and Perilampidae are both recorded. The results are compared to those recovered by surveys in other parts of the world, especially by the Janzen-Hallwachs survey of the Area de Conservacion Guanacaste (ACG) in Costa Rica. An annotated list of microgastrine genera not yet recorded at Yanayacu, but which we expect to eventually find there based on extrapolation from their known geographic distributions, is provided.
Average chest wall thickness at two anatomic locations in trauma patients.

Abstract Background Needle thoracostomy is the emergent treatment for tension pneumothorax. This procedure is commonly done using a 4.5cm catheter, and the optimal site for chest wall puncture is controversial. We hypothesize that needle thoracostomy cannot be performed using this catheter length irrespective of the site chosen in either gender. Methods A retrospective review of all chest computed tomography (CT) scans obtained on trauma patients from January 1, 2011 to December 31, 2011 was performed. Patients aged 18 and 80 years were included and patients whose chest wall thickness exceeded the boundary of the images acquired were excluded. Chest wall thickness was measured at the 2nd intercostal (ICS), midclavicular line (MCL) and the 5th ICS, anterior axillary line (AAL). Injury severity score (ISS), chest wall thickness, and body mass index (BMI) were analyzed. Results 201 patients were included, 54% male. Average (SD) BMI was 26 (7)kg/m 2 . The average chest wall thickness in the overall cohort was 4.08 (1.4)cm at the 2nd ICS/MCL and 4.55 (1.7)cm at the 5th ICS/AAL. 29% of the overall cohort (27 male and 32 female) had a chest wall thickness greater than 4.5cm at the 2nd ICS/MCL and 45% (54 male and 36 female) had a chest wall thickness greater than 4.5cm at the 5th ICS/AAL. There was no significant interaction between gender and chest wall thickness at either site. BMI was positively associated with chest wall thickness at both the 2nd and 5th ICS/AAL. Conclusion A 4.5cm catheter is inadequate for needle thoracostomy in most patients regardless of puncture site or gender.
Level-adjusted exponential smoothing for modeling planned discontinuities

Based on contextual information, forecasters often make judgmental adjustments to the forecasts of exponential smoothing models. This approach can produce sound initial forecasts, but it can result in diminished accuracy for forecast updates as well as misleading signaling effects. A proposed technique lets the forecaster include judgmental adjustments within an exponential smoothing model. For 20 real data series representing Virginia Medicaid expenses, forecasts are developed using the proposed technique and several alternatives, and they are updated through various simulated level shifts. The study shows that the proposed technique is more accurate than the alternatives in updating forecasts when a shift in level occurs approximately as planned. Other advantages of the proposed technique include automation through final reporting when the shift occurs as planned, better detection capability when the planned shift does not occur, and ease of adjusting the forecast when new assumptions about the planned change are warranted.
Activation of Kv7 (KCNQ) voltage-gated potassium channels by synthetic compounds

Voltage-gated Kv7 (or KCNQ) channels play a pivotal role in controlling membrane excitability. Like typical voltage-gated ion channels, Kv7 channels undergo a closed-to-open transition by sensing changes in transmembrane potential, and thereby mediate inhibitory K(+) currents to reduce membrane excitability. Reduction of Kv7 channel activity as a result of genetic mutation is responsible for various human diseases due to membrane hyperexcitability, including epilepsy, arrhythmia and deafness. As a result, the discovery of small compounds that activate voltage-gated ion channels is an important strategy for clinical intervention in such disorders. Because ligand binding can induce a conformational change leading to subthreshold channel opening, there is considerable interest in understanding the molecular basis of these 'gain-of-function' molecules. Although small-molecule activators of cation channels are rare, several novel compounds that activate Kv7 voltage-gated channels have been identified. Recent advances in defining the activator-binding sites and in understanding their mechanism of action have begun to provide insight into the activation of voltage-gated channels by synthetic compounds.
Sporadic primary hyperparathyroidism in young individuals: different disease and treatment?

Background Younger individuals with hyperparathyroidism may experience severe disease with a higher incidence of multigland disease (MGD) and operative failure, thereby requiring subtotal parathyroidectomy. This study examines the characteristics and surgical outcome of younger compared with older patients with sporadic primary hyperparathyroidism (SPHPT). Methods Prospectively collected data of 1101 patients with SPHPT who underwent parathyroidectomy at a single institution were retrospectively reviewed. Patients with multiple endocrine neoplasia (MEN), familial, secondary, or tertiary hyperparathyroidism, parathyroid carcinoma, rickets, or lithium induced disease were excluded. Patients were subdivided into two groups: (1) younger individuals ≤40 y of age (n = 110) and (2) older individuals >40 y of age (n = 991). Both age groups were compared for gender, clinical manifestations, pre- and postoperative laboratory values, MGD, operative success, and recurrent disease. Results There was greater male predominance in younger compared with older patients treated for SPHPT (41% versus 25%, P = 0.0004). Of the clinical manifestations of SPHPT, kidney stones were more common in younger compared with older individuals (45% versus 29%, P = 0.0006). Conversely, bone pain was more common in older compared with younger patients (32% versus 14%, P = 0.0002). There was no statistical difference in biochemical values, MGD, and outcome between both groups. Conclusions Despite male predominance and few differences in symptoms, SPHPT is a similar disease entity in both younger and older individuals. Patients from both age groups can be similarly treated for SPHPT with a high rate of operative success. Routine BNE and subtotal parathyroidectomy is not necessary in younger individuals.
Coarse-grained Molecular-level Analysis of Polyurea Properties and Shock-mitigation Potential

Several experimental investigations reported in the open literature clearly established that polyurea (PU), an elastic copolymer, has an unusually high ability to attenuate and disperse shock waves. This behavior of PU is normally attributed to its unique nanometer-scale two-phase microstructure consisting of (high glass-transition temperature, T g) hydrogen-bonded discrete, hard domains dispersed within a (low T g) contiguous soft matrix. However, details regarding the mechanism(s) responsible for the superior shock-wave mitigation capacity of PU are still elusive. In the present study, molecular-level computational methods and tools are used to help us identify and characterize these mechanism(s). Because the shock-wave front structure and propagation involve coordinated motion of a large number of atoms and nano-second to micro-second characteristic times, these phenomena cannot be readily analyzed using all-atom molecular-level modeling and simulation techniques. To overcome this problem, all-atom PU microstructure is coarse-grained by introducing larger particles (beads), which account for the collective degrees of freedom of the constituent atoms, the associated force-field functions determined and parameterized using all-atom computational results, and the resulting coarse-grained model analyzed using conventional molecular-level computational methods and tools. The results thus obtained revealed that a combination of different deformation mechanisms (primarily shock-induced ordering and crystallization of hard domains and coordinated shuffle-like lateral motion of the soft-matrix segments) is most likely responsible for the superior ability of PU to attenuate/disperse shock waves.
A study of the heterogenous structure of guinea pig lysosomal β-mannosidase using a polyclonal antibody

Abstract Lysosomal β-mannosidase (EC 3.2.11.25) has a functional size of 120–150 kDa, but the enzyme purified from guinea pig liver (GPL) reportedly gave a single band corresponding to a molecular mass of 110 kDa. In order to investigate the subunit structure and tissue-specific expression of β-mannosidase, we prepared a polyclonal antibody against GPL β-mannosidase in rabbits which immunoprecipitated β-mannosidase activity, free from other lysosomal hydrolase activity. Following storage at −20°C and SDS polyacrylamide gel electrophoresis in the presence of 2-mercapto-ethanol, a sample of purified GPL β-mannosidase gave a major Coomassie blue staining band at 97 kDa. This was confirmed by Western blot analysis, which also revealed a faster moving 37 kDa protein. In contrast, Western blot analysis of fresh GPL homogenate prepared in the presence of proteinase inhibitors showed a major band at 150 kDa. Upon freezing and thawing, we observed immunoreactive bands at 120 and 20 kDa and finally, immunoreactive bands at 97, 37 and 20 kDa. The formation of the 97, 37 and 20 kDa forms from the 150 kDa species was accelerated by an n-butanol/ether extraction of the associated lipids, suggesting some tight hydrophobic association of these subunits. In contrast to liver, both fresh and freeze-thawed preparations of guinea pig kidney (GPK) yielded only the 97, 37 and 20 kDa subunit forms confirming that these are the major β-mannosidase subunits. Endo-F treatment converted both the liver and kidney 97 kDa into a 91 kDa form and the 37 kDa form into a 35 kDa form, whereas the 20 kDa form was unaffected. Total β-mannosidase activity, as measured with the synthetic substrate 4MU-β-mannoside was unaffected by dissociation of the 150 form into the 97, 37 and 20 kDa subunits, suggesting that these are the functional forms of the enzyme rather than proteolytic degradation products.
Can government policies help adolescents avoid risky behavior

Abstract Background . This study examines the extent to which policies influence participation of adolescents in alcohol and tobacco consumption and in unsafe sex. Methods . Data were obtained from the 1995 Youth Risk Behavior Surveys (YRBS) conducted by 20 different states and cities in the U.S. These data were combined with state data on cigarette taxes, vending machine laws, beer taxes, and family planning clinic availability. A model of teenage risk taking suggested that the three risk behaviors were codetermined by a common latent risk-taking propensity. We used a structural equation model (SEM) accounting for this shared latent propensity to estimate the extent of participation in terms of frequency of smoking, drinking, and the number of sex partners. Results . Estimating simultaneous equations for all three risk behaviors was statistically more efficient than equation-by-equation estimates of each behavior. Estimates indicated significant deterrent effects of beer taxes, vending machine restrictions, and increased density of family planning clinics on teenage risk behavior. Conclusions . State policies, such as taxes on beer, and restrictions on location of cigarette vending machines, and placement of family planning clinics influence adolescents' behavior. Because there is interrelationship between these behaviors, systems estimators, can offer improved estimates of these effects.
Evaluation of Mechanical and Barrier Properties of Protein Coatings on Shell Eggs

Abstract Development of a coating material for shell eggs is important because of economic loss from shell damage and decline in interior egg quality. Studies were done to evaluate the interior quality (moisture loss, Haugh unit, and pH) and shell properties (strength, thickness, morphology, and color) of uncoated eggs and eggs coated with mineral oil or with solutions of egg albumen, soy protein isolate, wheat gluten, or corn zein. Coated shell eggs were evaluated during 1, 3, 5, 7, 10, 14, 21, and 28 d of storage at room temperature. Eggshells coated with corn zein solution exhibited the least moisture loss and the strongest shell strength. Light microscopy depicted a more compact structure of eggshells coated with corn zein solution. Shell eggs coated with corn zein exhibited the lowest moisture loss and maintained a higher Haugh unit than eggs coated with other treatments. Results also indicated that the protein-based coatings, corn zein and wheat gluten, added strength to the shell, which, in turn, served as a protective barrier.
Impulsiveness without discounting: the ecological rationality hypothesis

Observed animal impulsiveness challenges ideas from foraging theory about the fitness value of food rewards, and may play a role in important behavioural phenomena such as cooperation and addiction. Behavioural ecologists usually invoke temporal discounting to explain the evolution of animal impulsiveness. According to the discounting hypothesis, delay reduces the fitness value of the delayed food. We develop an alternative model for the evolution of impulsiveness that does not require discounting. We show that impulsive or short-sighted rules can maximize long-term rates of food intake. The advantages of impulsive rules come from two sources. First, naturally occurring choices have a foreground-background structure that reduces the long-term cost of impulsiveness. Second, impulsive rules have a discrimination advantage because they tend to compare smaller quantities. Discounting contributes little to this result. Although we find that impulsive rules are optimal in a simple foreground-background choice situation in the absence of discounting, in contrast we do not find comparable impulsiveness in binary choice situations even when there is strong discounting.
On the approximation property of excellent rings

where D is a smooth finite type A-algebra? A theorem, which would imply the existence of an embedding of the above type, yields the positive solution of the Bass-Quillen conjecture. So far this theorem is only known in special cases. There is the following result by Artin [3, 4].
Antiarrhythmic Properties of Acetaminophen in the Dog

Mongrel dogs bred for research and weighing 25 +/- 3 kg were used to test the hypothesis that acetaminophen has antiar-rhythmic properties. Only ventricular arrhythmias defined by the Lambeth Conventions were investigated. Dogs were exposed either to 60 mins of regional myocardial ischemia followed by 180 mins of reperfusion (n = 14) or were administered a high dose of ouabain (n = 14). Both groups of 14 dogs were further divided into vehicle and acetaminophen treatment groups (n = 7 in each). During selected 10-min intervals, we recorded the numbers of ventricular premature beats, ventricular salvos, ventricular bigeminy, ventricular tachycardia (nonsustained and sustained), and we recorded the heart rate, systemic arterial blood pressure, and left ventricular function. Neither heart rate nor the number of ventricular arrhythmias differed significantly under baseline conditions. Conversely, the combined average number of ventricular ectopic beats during ischemia and reperfusion was significantly less in the presence of acetaminophen (28 +/- 4 vs. 6 +/- 1; P < 0.05). Similarly, percent ectopy during reperfusion in vehicle- and acetaminophen-treated dogs was 1.4 +/- 0.4 and 0.4 +/- 0.2, respectively (P < 0.05). The number of all ventricular ectopic beats except ventricular salvos was also significantly reduced in the presence of acetaminophen. Similar results were obtained with ouabain. Our results reveal that systemic administration of a therapeutic dose of acetaminophen has previously unreported antiarrhythmic effects in the dog.
Characteristics associated with smoking in a Hispanic college student sample.

This study examined the smoking related behaviors of Hispanic young adult college students as part of a larger study that assessed characteristics of Hispanic smokers in a metropolitan area on the U.S./Mexico border. One hundred seventy-four English-speaking Hispanic college students completed questionnaires that assessed tobacco use, drug/alcohol use, body mass index, weight concerns, acculturation, depressive symptoms, and expired carbon monoxide level. Of the 74 smoking participants (42.5% of the sample), 77% reported light or intermittent smoking. Univariate analyses and a backward elimination logistic regression model were used to compare smokers' and nonsmokers' characteristics. Significant univariate differences between smokers and nonsmokers were higher reported weekly alcohol use and ever use of marijuana. Logistic regression findings indicated smokers reported heightened odds of being younger, lower acculturation, ever use of drugs, and weekly drinking. These results suggest a drug and alcohol use component is important to cessation interventions targeted toward Hispanic college student smokers.
“The World He'd Lost”: Geography and “Green” Memory in Cormac McCarthy's The Road

ABSTRACT In Cormac McCarthy's 2006 Pulitzer Prize-winning novel, The Road, a father and his son travel the blasted, ruined landscape of a postapocalyptic America. The father remembers the logic, beauty, and order of America's old topography, but he must now confront a new landscape where old signs mean nothing, where old signals are removed of meaning, and where formerly safe, understood, and beautiful places are instead sites of sheer horror. The son, in contrast, born after the event that caused the ruin, knows nothing of the former world and relies only on his father's stories and memories of that world's landscapes. As the pair moves across the barren spaces of this “new” America, these memories create (for the father, the son, and for the reader) both a decipherable and an unknowable terrain simultaneously. My essay focuses on this composite geography within McCarthy's novel, examining the ways in which the world's geographical and emotional meaning has been broken in the text. Disaster and ruin have...
The effect of network structure on moisture absorption of epoxy resins

An investigation of the effect of modifying the network structure on moisture absorption of epoxies was performed. The network was modified by crosslinking the epoxides wth various mono/diamine proportions, resulting in decreasing density and increasing free volume. It was discovered, however, that concomitant effects, i.e., the formation of a two-phase structure, and changes in resin polarity and in resin-water affiniy predominated. Thus, compositions with higher chain molecular weights between crosslink points yet exhibited lower diffusion coeficients. Also, when drastic swelling conditions (such as a water-boil treatment) were employed, moisture absorption was facilitated by penetration via newly formed microcracks.
Dose and time dependency of angiotensin II inhibition of hippocampal long-term potentiation

Abstract We previously reported that injection of 1.0 μl of 4.78 μ M angiotensin II (AII) above the hippocampus in rats inhibits long-term potentiation (LTP) induction in medial perforant path-stimulated dentate granule cells. The present experiments were conducted in urethane-anesthetized Sprague-Dawley rats. LTP was measured in terms of the relative change in slope of the population EPSP compared to baseline. Effects of 0.48, 0.956, 1.195, 2.39, and 4.78 μ M AII and time delays of 30, 60, 90, and 150 min with the 4.78 μ M dose were determined. Results were significant and demonstrate that AII inhibition of LTP in dentate granule cells is both dose and time dependent. The threshold is approximately 1.0 pmol of peptide. Inhibition due to the 4.78 μ M AII begins slowly after 1 h and is complete over the next 30 min, continues for another 30 min, and then fully recovers by the end of the next 30 min. This time dependency could be due to the internalization of the AII, interaction with a cytosolic receptor, and eventual degradation.
Autonomy and interdependence: an intermediate position

It is suggested that there are distributed system design choices which, for certain environments, permit machines to retain substantial degrees of autonomy while at the same time support the effect of integrated operation. That is, most of the drawbacks to autonomous designs and global control can be avoided while providing most of the advantages that encourage either choice. This point of view is motivated by experiences with the Locus distributed UNIX operating system and its derivative, IBM's AIX TCF.
Telephone-traffic techniques

Given well designed and reliable equipment, the efficiency of a telecommunication system depends on having sufficient equipment to meet requirements for normal service, with a reasonable margin for peak traffic. At the same time, the cost of the network must be low enough to permit the provision of an efficient service to the subscriber on acceptable terms. The determination of the amount and arrangement of equipment, so as to achieve an optimum balance between service and cost, is one of the most important aspects of telecommunication-system design, which has attracted the attention of engineers and mathematicians since the early days of telephony. Modern technical developments, including the application of electronic switching and control techniques, have posed many new traffic problems. This review deals with the general principles of telecommunication traffic, and their application to exchange and network engineering.
Surface Adaptations of The Vertebrate Epidermis to Friction

Epidermal surfaces in representative vertebrates specialized for lowered or increased friction were studied with the scanning electron microscope. Microvillous and microridged patterns predominate in aquatic vertebrates. In squamate reptiles, the complex and varied ornamentation of the Oberhautchen functions both in adhesive modifications and in modulating surface reflectivity. Frictional surfaces in birds and mammals are characterized more by anatomical than by cytologic specializations, the detailing of surface cells being mostly a function of turnover rate.
The effect of in vitro heat stress on the uptake of neutral red by chicken thrombocytes

Thrombocytes are multifunctional, nucleated blood cells. Morphological changes in thrombocytes have been used as a physiological indicator of a stress response. This study investigated the effects of in vitro heat stress (HS) on the neutral red uptake activity of chicken thrombocytes. Chicken thrombocytes (98% pure) were prepared from adult Barred Plymouth Rock and Rhode Island Red males. The isolated thrombocytes were preincubated at normal (41 C) or HS (45 C) temperatures for 30 min before either a 30- or 90-min incubation with neutral red at these same temperatures. After incubation the cells were washed, lysed, and the internal neutral red concentrations analyzed. There was no difference in thrombocyte numbers or their uptake of neutral red in samples from males of these two chicken breeds. At 41 C thrombocytes actively took up neutral red over the 90-min incubation period. However, at 45 C thrombocyte internalization of neutral red was significantly reduced. At both time periods (30 and 90 min), thrombocytes at 41 C took up significantly (P < or = 0.05) more neutral red than their counterparts at 45 C. This lack of neutral red uptake was not due to cell death as monitored by Trypan blue exclusion. Following the 30-min incubation there was no difference in viability between thrombocytes at the two temperatures. Although there was a significant (P < or = 0.05) increase in cell death at 90 min for thrombocytes kept at 45 C, the livability difference was of a much smaller magnitude than the difference in neutral red uptake when comparing to cells cultured at 41 C. Neutral red uptake is a rapid, inexpensive and repeatable technique for the study of thrombocyte function.
Cosmic-ray shower generator (CRY) for Monte Carlo transport codes

The CRY software library generates correlated cosmic-ray particle shower distributions at one of three elevations (sea level, 2100 m, and 11300 m) for use as input to transport and detector simulation codes. Our simulation is based on precomputed input tables derived from full MCNPX simulations of primary cosmic rays on the atmosphere and benchmarked against published cosmic-ray measurements. Our simulation provides all particle production (muons, neutrons, protons, electrons, photons, and pions) with the proper flux within a user-specified area and altitude. The code generates individual showers of secondary particles sampling the energy, time of arrival, zenith angle, and multiplicity with basic correlations, and has user controls for latitude (geomagnetic cutoff) and solar cycle effects. We provide a function library, callable from C, C++, and Fortran, and interfaces to popular Monte Carlo transport codes (MCNP, MCNPX, COG, Geant4). The software library and examples can be downloaded from http://nuclear.llnl.gov/simulation.
Illness Experiences of Homeless Youth

The purpose of this study was to document the illness experiences of homeless youth. The research was a focused ethnography with 45 clinic- and street-based homeless youth aged 15 to 23 years. The authors noted gender differences for health-seeking behaviors, with most male youth reporting embarrassment about needing to seek care, and female youth reporting fears over safety issues while ill and homeless. Most youth under age 18 stated that they were often denied health care at hospitals because of their underage status, and youth over age 18 stated that health care bills contributed to their inability to obtain stable housing. Street-based youth reported more illnesses related to substance use and greater reliance on emergency departments for health care than clinic-based youth did. Policies and programs focused on improving the health of homeless youth need to address the differences in illness experiences by age, gender, and sampling site.
Structure, conformation and dynamics of polymer chains at solid melt interfaces

We have performed molecular dynamics, and lattice Monte Carlo simulations of polymeric melts in the vicinity of solid surfaces. The structural features of the solid-melt interface were very simple. The interfacial width was comparable to the segment size. Inside this narrow interface the segment density profile was oscillatory. The density oscillations were much less pronounced than those present at solid-atomic liquid interfaces. On a scale much larger than the segment size, chain conformations were found to be identical with those of ideal chains next to a reflective barrier. In particular, the number of surface-segment contacts scaled like the square root of the molecular weight. Extensive molecular dynamics simulations showed that chain desorption times increase with molecular weight but at a rate much slower than the longest relaxation time of Rouse chains. Therefore, sufficiently long chains desorbed almost freely from the surface despite the presence of attractive surface-segment interactions. A study of chain relaxation dynamics confirmed that the Rouse modes constitute an appropriate set of normal coordinates for chains in the melt interacting with a solid surface. The effect of the surface on mode relaxation was significant. All relaxation processes of chains located within a couple of radii of gyration from the surface were slowed down considerably. This effect, however was approximately the same for fast and slow modes and independent of molecular weight for sufficiently long chains.
The RNA binding domain of Pumilio antagonizes poly-adenosine binding protein and accelerates deadenylation

PUF proteins are potent repressors that serve important roles in stem cell maintenance, neurological processes, and embryonic development. These functions are driven by PUF protein recognition of specific binding sites within the 3' untranslated regions of target mRNAs. In this study, we investigated mechanisms of repression by the founding PUF, Drosophila Pumilio, and its human orthologs. Here, we evaluated a previously proposed model wherein the Pumilio RNA binding domain (RBD) binds Argonaute, which in turn blocks the translational activity of the eukaryotic elongation factor 1A. Surprisingly, we found that Argonautes are not necessary for repression elicited by Drosophila and human PUFs in vivo. A second model proposed that the RBD of Pumilio represses by recruiting deadenylases to shorten the mRNA's polyadenosine tail. Indeed, the RBD binds to the Pop2 deadenylase and accelerates deadenylation; however, this activity is not crucial for regulation. Rather, we determined that the poly(A) is necessary for repression by the RBD. Our results reveal that poly(A)-dependent repression by the RBD requires the poly(A) binding protein, pAbp. Furthermore, we show that repression by the human PUM2 RBD requires the pAbp ortholog, PABPC1. Pumilio associates with pAbp but does not disrupt binding of pAbp to the mRNA. Taken together, our data support a model wherein the Pumilio RBD antagonizes the ability of pAbp to promote translation. Thus, the conserved function of the PUF RBD is to bind specific mRNAs, antagonize pAbp function, and promote deadenylation.
Optimal structuring elements for the morphological pattern restoration of binary images

In this paper, we derive the optimal structuring elements of morphological filters in image restoration. The expected pattern transformation of random sets is presented. An estimation theory framework for random sets is subsequently proposed. This framework is based on the least mean difference (LMD) estimator. The LMD estimator is defined to minimize the cardinality of the expected pattern transformation of the set-difference of the parameter and the estimate. Several important results for the determination of the LMD estimator are derived. The LMD structuring elements of morphological filters in image restoration are finally derived. >
Knowledge reorganization. A rule model scheme for efficient reasoning

Discusses the application of conceptual clustering in restructuring large knowledge bases for the purpose of improving their complex problem solving efficiency. The rule base of PLAYMAKER, a system for characterizing hydrocarbon fields and plays, is restructured into a hierarchy of rule models using our conceptual clustering scheme, ITERATE. The rule models, used with a task-specific reasoning methodology, provide a more efficient, focused, and robust inferencing mechanism. A set of case studies that have been conducted demonstrate the improved performance of the reasoning system. PLAYMAKER is implemented on MIDST (Mixed Inferencing Dempster-Shafer Tool), a general-purpose knowledge-based system construction tool that incorporates reasoning mechanisms based on a task-specific architecture and belief functions. >
Increased tissue oxygen extraction and acidosis with progressive severity of sepsis.

Abstract Background. Lactic acidosis and increased production of CO 2 are common in septic shock. Presumably, both acidosis and CO 2 enhance the release of oxygen from hemoglobin. The purpose of this study was to assess the relationship of oxygen utilization, CO 2 production, acidosis, and hemoglobin oxygen (Hgb-O 2 ) dissociation with progressive severity of sepsis to shock. Materials and methods. Femoral arterial and vein, hepatic vein, portal vein, and pulmonary artery catheters were placed in 16 anesthetized swine. Organ blood flow was determined by timed injections of colored microspheres. After baseline measurements, Pseudomonas aeruginosa was infused in eight animals. This bacterial slurry was continued inciting a progression of sepsis to shock. Eight animals served as instrumented controls. Results. With sepsis and shock, there was a progressive decrease in pH and an increase in pCO 2 in plasma with all sampling sites ( P versus baseline versus control). Blood flow to the liver and intestines increased with sepsis ( P 2 and/or percent O 2 extraction increased with sepsis and septic shock for the whole body and for the liver, intestine and leg ( P 2 saturation, acidosis, and pCO 2 to percent O 2 extraction ( r > 60; P 50 values for Hgb-O 2 dissociation remained unchanged. Conclusions. This study demonstrates that increased oxygen extraction in severe sepsis is related to a fall in tissue oxygen availability and not related to any allosteric change in Hgb-O 2 dissociation. Therefore, acidosis and hypercapnia do not have a demonstrable effect on altering oxygen availability during sepsis.
Climate volatility deepens poverty vulnerability in developing countries

Extreme climate events could influence poverty by affecting agricultural productivity and raising prices of staple foods that are important to poor households in developing countries. With the frequency and intensity of extreme climate events predicted to change in the future, informed policy design and analysis requires an understanding of which countries and groups are going to be most vulnerable to increasing poverty. Using a novel economic-climate analysis framework, we assess the poverty impacts of climate volatility for seven socio-economic groups in 16 developing countries. We find that extremes under present climate volatility increase poverty across our developing country sample—particularly in Bangladesh, Mexico, Indonesia, and Africa—with urban wage earners the most vulnerable group. We also find that global warming exacerbates poverty vulnerability in many nations.
BMPs for sale!: Implications from a case study in BMP auctions

Over the past several decades, there has been an increase in the use of market-based approaches for environmental policy. The purpose of this paper is three-fold: 1) to provide a review of the literature on auction-based approaches to environmental management, 2) to gain insight into the use and effectiveness of an alternative auction designs, and 3) to present con- siderations for enhancing the use of flexible auction approaches for future environmental ap- plication. Specifically, this paper describes how innovative BMP auctions were used to dis- tribute conservation funding in a small watershed in east-central Kansas and offers insights into their overall cost-effectiveness. Overall, there were 61 bids for practices requesting a total of $98,524 in funding. Through the bid evaluation process, 46 of the bids were actually fund- ed, which resulted in an estimated 2,901 tonnes of annual soil erosion reduction. This came at a total cost of $62,566. The lessons learned from the project can help guide future conservation programs seeking market-based solutions to bring about environmental benefits and re- searchers interested in analyzing the effectiveness of these mechanisms.
Mice heterozygous for a defect in mitochondrial trifunctional protein develop hepatic steatosis and insulin resistance.

Background & Aims: Little is known about the role of mitochondrial β-oxidation in development of nonalcoholic fatty liver disease (NAFLD). Mitochondrial trifunctional protein (MTP) catalyzes long-chain fatty acid oxidation. Recently, we generated a mouse model for MTP deficiency and reported that homozygous ( MTPa −/− ) mice suffer neonatal death. In this study, we investigated effects of heterozygosity for the MTP defect on hepatic oxidative stress, insulin resistance, and development of NAFLD in mice. Methods: We evaluated liver histopathology, serum alanine aminotransferase (ALT), glucose, fatty acids, and insulin levels in MTPa +/− and MTPa +/+ littermates. Insulin resistance was evaluated using glucose tolerance test (GTT) and insulin tolerance test (ITT). Liver tissues were used to measure triglyceride and fatty acid content, activity of superoxide dismutases (SOD) and glutathione peroxidase (GPx), glutathione (GSH), and cytochrome P-450 2E1 expression. Results: Aging but not young MTPa +/− mice developed hepatic steatosis with elevated ALT, basal hyperinsulinemia, and increased insulin area under curve (AUC) on GTT compared with MTPa +/+ littermates. In response to insulin challenge, aging MTPa +/− mice had slower rate of glucose disappearance and increased glucose AUC. Significant hepatic steatosis and insulin resistance developed concomitantly in the MTPa +/− mice at 9–10 months of age. Aging MTPa +/− mice had higher antioxidant activity of total SOD and GPx, lower GSH, and increased expression of cytochrome P-450 2E1, consistent with increased hepatic oxidative stress. Conclusions: Heterozygosity for β-oxidation defects predisposes to NAFLD and insulin resistance in aging mice. Impairment of mitochondrial β-oxidation may play an important role in pathogenesis of NAFLD.
Monitoring of cellular resistance to cancer chemotherapy

Cellular resistance to a broad spectrum of natural products used as antitumor drugs is believed to be a major cause for the failure of chemotherapy. Flow cytometry has been used for monitoring the expression of drug resistance markers, determining accumulation of fluorescent drugs, and for screening of drugs that enhance chemosensitivity by blocking efflux and enhancing drug retention. This article reviews recent developments in our understanding of the multiple drug resistance phenotype and the use of flow cytometry for the study of drug efflux and its modulation in human tumor cells.
MIMO communication theory, algorithms, and prototyping

This tutorial will present a brief overview of MIMO fundamentals, including information theory basics, space-time coding, spatial multiplexing, multiuser MIMO, and MIMO interference alignment. Owing to their great promise, MIMO systems have found their way in several standards for future wireless communications systems, especially for wireless local area networks and cellular networks. Examples of these standards include IEEE 802.11, 802.16 (WiMAX), HSPDA, and LTE. Several MIMO configurations are being considered for these applications, including 2×2 and 4×4 with space-time block coding schemes. Since MIMO technology is now included in emerging wireless standards, we need to equip wireless practitioners with tools that enable them to implement MIMO techniques for real-world systems such as IEEE 802.11,WiMAX, HSPDA, and LTE. The major objective of the tutorial is to expose the audience to the system level design flow and prototyping of basic MIMO communication techniques based on an FPGA based demo platform. In particular, the tutorial will explain some of the practical difficulties in designing and implementing MIMO systems based on an experimental MIMO hardware platform that has been developed. It will also briefly review effective and novel real-time algorithms that balance complexity/performance tradeoffs.
Effect of Impurities on Interfacial Void Formation in Aluminum

The effect of impurities on formation of interfacial metallic voids, during uniform dissolution of aluminum in 1 M NaOH, was investigated. These voids are thought to act as initiation sites for pitting corrosion, and were previously shown to be formed by NaOH dissolution. Samples of three different bulk purities were compared: 99.98, 99.997, and 99.9995%. Positron annihilation spectroscopy and atomic force microscopy revealed that nanometer-scale voids were formed by dissolution in each foil. For each sample, the void volume fraction interpreted from these measurements increased to a maximum during dissolution, and then declined. As the purity increased, more extensive dissolution was required to produce voids. Accumulation of near-surface Cu and Fe impurities during dissolution was characterized using Rutherford backscattering spectrometry. The results suggested a possible general correlation of void volume fraction with copper surface concentration. Processes involving near-surface copper impurities may then at least partly control the formation of voids. © 2004 The Electrochemical Society. @DOI: 10.1149/1.1666148# All rights reserved.
Mycobacterium tuberculosis Cell Wall Glycolipids Directly Inhibit CD4 T-Cell Activation by Interfering with Proximal T-Cell-Receptor Signaling

Immune evasion is required for Mycobacterium tuberculosis to survive in the face of robust adaptive CD4+ T-cell responses. We have previously shown that M. tuberculosis can indirectly inhibit CD4+ T cells by suppressing the major histocompatibility complex class II antigen-presenting cell function of macrophages. This study was undertaken to determine if M. tuberculosis could directly inhibit CD4+ T-cell activation. Murine CD4+ T cells were purified from spleens by negative immunoaffinity selection followed by flow sorting. Purified CD4+ T cells were activated for 16 to 48 h with CD3 and CD28 monoclonal antibodies in the presence or absence of M. tuberculosis and its subcellular fractions. CD4+ T-cell activation was measured by interleukin 2 production, proliferation, and expression of activation markers, all of which were decreased in the presence of M. tuberculosis. Fractionation identified that M. tuberculosis cell wall glycolipids, specifically, phosphatidylinositol mannoside and mannose-capped lipoarabinomannan, were potent inhibitors. Glycolipid-mediated inhibition was not dependent on Toll-like receptor signaling and could be bypassed through stimulation with phorbol 12-myristate 13-acetate and ionomycin. ZAP-70 phosphorylation was decreased in the presence of M. tuberculosis glycolipids, indicating that M. tuberculosis glycolipids directly inhibited CD4+ T-cell activation by interfering with proximal T-cell-receptor signaling.
Immunolocalization and Regulation of Cystatin 12 in Mouse Testis and Epididymis

In previous studies, we identified a new member of the male reproductive tract subgroup within family 2 cystatins, termed cystatin 12 (Cst12, previously known as Cst TE-1 or Cres3). The mouse Cst12 mRNA was primarily localized to the Sertoli cells in the testis and to the epithelial cells of the proximal caput region of the epididymis. In this report, studies were carried out to characterize the cystatin 12 (CST12) protein in mouse testis and epididymis. A recombinant His-CST12 fusion protein was expressed in E. coli and purified to generate an anti-CST12 polyclonal antibody. Western blot analysis showed little or no cross-reaction between the anti-CST12 antibody and several other known male reproductive tract cystatins. Immunohistochemistry revealed that CST12 protein was predominantly localized to the cytoplasm of Sertoli cells in the seminiferous epithelium in a stage-dependent manner. All stages showed high levels of expression except stages VII and VIII, in which very limited expression of CST12 was observed. In the epididymis, CST12 was highly expressed in the cytoplasm of the epithelial cells in the proximal caput and secreted into the lumen. The mouse CST12 protein was also detected in other regions of the epididymis; however, the localization varied greatly along the epididymal tubules. Indirect immunofluorescence showed that CST12 protein was localized to the cytoplasmic droplets in both testicular and epididymal spermatozoa. These observations suggest that CST12 protein may play a specialized role during spermatogenesis and sperm maturation. Northern blot analyses demonstrated that Cst12 transcript levels in the epididymis decreased after castration, and testosterone propionate (T) treatment further repressed the expression of this gene. However, 17-beta estradiol (E) administration maintained the expression of Cst12 mRNA after castration, whereas treatment with both T and E failed to maintain Cst12 mRNA levels in epididymis. These results suggest that androgen and estrogen, probably with other testicular factors, are involved in the regulation of this gene.