cssi/SciSciGPT-SciSciNet huggingface dataset:
Silencing of Oncogenic KRAS by Mutant-Selective Small Interfering RNA

Oncogenic mutations in the KRAS gene are well-established drivers of cancer. While the recently developed KRASG12C inhibitors offer a targeted KRAS therapy and have shown success in the clinic, KRASG12C represents only 11% of all KRAS mutations. Current therapeutic approaches for all other KRAS mutations are both indirect and nonmutant-selective, largely focusing on inhibition of downstream KRAS effectors such as MAP kinases. Inhibition of KRAS downstream signaling results in a system-wide down-modulation of the respective targets, raising concerns about systemic cell toxicity. Here, we describe a custom short interfering RNA oligonucleotide (EFTX-D1) designed to preferentially bind mRNA of the most commonly occurring KRAS missense mutations in codons 12 and 13. We determined that EFTX-D1 preferentially reduced the mutant KRAS sequence versus wild-type at the levels of both transcription and translation and reversed oncogenic KRAS-induced morphologic and growth transformation. Furthermore, EFTX-D1 significantly impaired the proliferation of several KRAS mutant cancer cell lines in 2-D as well as 3-D assays. Taken together, our data indicate a novel use of RNA interference to target oncogenic KRAS-driven cancers specifically.
Manifestations of domination: Assessments of social dominance in rodents

Social hierarchies are ubiquitous features of virtually all animal groups. The varying social ranks of members within these groups have profound effects on both physical and emotional health, with lower-ranked individuals typically being the most adversely affected by their respective ranks. Thus, reliable measures of social dominance in preclinical rodent models are necessary to better understand the effects of an individual's social rank on other behaviors and physiological processes. In this review, we outline the primary methodologies used to assess social dominance in various rodent species: those that are based on analyses of agonistic behaviors, and those that are based on resource competition. In synthesizing this review, we conclude that assays based on resource competition may be better suited to characterize social dominance in a wider variety of rodent species and strains, and in both males and females. Lastly, albeit expectedly, we demonstrate that similarly to many other areas of preclinical research, studies incorporating female subjects are lacking in comparison to those using males. These findings emphasize the need for an increased number of studies assessing social dominance in females to form a more comprehensive understanding of this behavioral phenomenon.
Energy Balance-Related Behavior Risk Pattern and Its Correlates During COVID-19 Related Home Confinement

Self-reported weight gain during the COVID-19 shelter-at-home has raised concerns for weight increases as the pandemic continues. We aimed to investigate the relationship of psychological and health markers with energy balance-related behaviors during the pandemic-related extended home confinement. Ratings for stress, boredom, cravings, sleep, self-control, and beliefs about weight control were collected from 1,609 adults using a questionnaire between April 24th-May 4th, 2020, while COVID-19 associated shelter-in-place guidelines were instituted across the US. We calculated four energy balance behavior scores (physical activity risk index, unhealthy eating risk index, healthy eating risk index, sedentary behavior index), and conducted a latent profile analysis of the risk factors. We examined psychological and health correlates of these risk patterns. Boredom, cravings for sweet/savory foods, and high sleepiness ratings related to high risk of increasing unhealthy eating and sedentary behavior and decreasing physical activity and healthy eating. Having greater self-control, control over cravings, or positive mood was related to lowering all aspects of energy intake and energy expenditure risks. Although individuals in risk pattern classes showed similarity in physical activity and healthy/unhealthy eating habits, they exhibited different patterns of positive mood, craving control, food cravings, boredom, and self-control. Psychological and health variables may have a significant role to play in risk behaviors associated with weight gain during the COVID-19 related home confinement. Emerging behavioral patterns may be meaningful in developing targeted weight management interventions during the current pandemic.
Nicotine-like discriminative and aversive effects of two α4β2-selective nicotine agonists, ispronicline and metanicotine.

An attempt to determine the receptor selective nature of some of nicotine's behavioral effects was undertaken through the evaluation of the ability of two nicotinic α4β2*-selective receptor agonists to produce nicotine-like effects and modify rates of responding in a discrimination assay and in an aversive stimulus assay. A group of eight rats was trained to discriminate the presence of 1 mg/kg nicotine base. Another group of 4-6 rats was trained to report the aversive effects of nicotine by selecting a lever that produced one food pellet over a second lever that produced two food pellets and an intravenous injection of nicotine. Ispronicline and metanicotine, two α4β2*-selective receptor agonists, increased selection of the nicotine-appropriate lever in a dose-related manner, up to a maximum of approximately 75%. The α4β2*-selective receptor antagonist, dihydro-beta-erythroidine blocked both the discriminative stimulus effects and the rate-suppressing effects of ispronicline, metanicotine, and small, but not large doses of nicotine. The nonselective antagonist, mecamylamine, antagonized the discriminative stimulus effects of each of the three nicotine agonists as well as the rate-decreasing effects of nicotine and metanicotine. Mecamylamine did not modify the rate-decreasing effects of ispronicline. Both ispronicline and metanicotine as well as nicotine were avoided in the drug + food vs. food choice situation. The receptor-selective nature of ispronicline and metanicotine was hereby confirmed in a behavioral assay, as were earlier reports that the discriminative stimulus effects of relatively small doses of nicotine are likely mediated by activity at the α4β2* nicotine receptor.
WE-EF-303-06: Feasibility of PET Image-Based On-Line Proton Beam-Range Verification with Simulated Uniform Phantom and Human Brain Studies

Purpose: To study the feasibility of clinical on-line proton beam range verification with PET imaging Methods: We simulated a 179.2-MeV proton beam with 5-mm diameter irradiating a PMMA phantom of human brain size, which was then imaged by a brain PET with 300*300*100-mm^3 FOV and different system sensitivities and spatial resolutions. We calculated the mean and standard deviation of positron activity range (AR) from reconstructed PET images, with respect to different data acquisition times (from 5 sec to 300 sec with 5-sec step). We also developed a technique, “Smoothed Maximum Value (SMV)”, to improve AR measurement under a given dose. Furthermore, we simulated a human brain irradiated by a 110-MeV proton beam of 50-mm diameter with 0.3-Gy dose at Bragg peak and imaged by the above PET system with 40% system sensitivity at the center of FOV and 1.7-mm spatial resolution. Results: MC Simulations on the PMMA phantom showed that, regardless of PET system sensitivities and spatial resolutions, the accuracy and precision of AR were proportional to the reciprocal of the square root of image count if image smoothing was not applied. With image smoothing or SMV method, the accuracy and precision could be substantially improved. For a cylindrical PMMA phantom (200 mm diameter and 290 mm long), the accuracy and precision of AR measurement could reach 1.0 and 1.7 mm, with 100-sec data acquired by the brain PET. The study with a human brain showed it was feasible to achieve sub-millimeter accuracy and precision of AR measurement with acquisition time within 60 sec. Conclusion: This study established the relationship between count statistics and the accuracy and precision of activity-range verification. It showed the feasibility of clinical on-line BR verification with high-performance PET systems and improved AR measurement techniques. Cancer Prevention and Research Institute of Texas grant RP120326, NIH grant R21CA187717, The Cancer Center Support (Core) Grant CA016672 to MD Anderson Cancer Center
Role of stress in neuropsychiatric and neurocognitive disorders in older adults, specifically on late life depression and cognition

Recent investigations suggest the Hypothalamic-PituitaryAdrenal Axis (HPA) plays an important role in neuropsychiatric and neurocognitive disorders in older adults. Effects of HPA activity on cognition and depression are well documented. It is unclear, however, if this relationship is mediated by psychosocial stress. Here we report on the current status of the literature in this field and also present our findings from a large, longitudinal investigation of the interaction of psychosocial stress and HPA activity on neurocognitive and neuropsychiatric function. In a sample of 162 community-dwelling older adults, aged 60–102 years, we investigated the relationship of waking cortisol, slope of diurnal cortisol and psychosocial stress to cognition, mood and brain function. Older adults with increased waking cortisol exhibited poorer memory performance (p < 0.01). This effect was strongest in individuals with the Apolipoprotein e4 allele, who are at increased risk for the development of cognitive decline and dementia. Additionally, older adults with higher waking cortisol had reduced hippocampal volumes (p < 0.01). There was no effect of slope of diurnal cortisol on any of the cognitive or brain measures, in either e4 or none4 carriers. Although we observed no impact of cortisol on mood, individuals with the short allele of the 5HTT gene promoter polymorphism region (5HTTLPR), which is associated with lower levels of serotonin uptake, had poorer cognitive function and higher levels of cortisol. Strikingly, none of these observed effects were impacted by psychosocial stress. Implications of our findings for the role of neuroendocrine function in age-related neurocognitive and neuropsychiatric disorders will be discussed. from International Society on Brain and Behaviour: 2nd International Congress on Brain and Behaviour Thessaloniki, Greece. 17–20 November 2005
Image segmentation using topological persistence

This paper presents a new hybrid split-and-merge image segmentation method based on computational geometry and topology using persistent homology. The algorithm uses edge-directed topology to initially split the image into a set of regions based on the Delaunay triangulations of the points in the edge map. Persistent homology is used to generate three types of regions: p-persistent regions, p-transient regions, and d-triangles. The p-persistent regions correspond to core objects in the image, while p-transient regions and d-triangles are smaller regions that may be combined in the merge phase, either with p-persistent regions to refine the core or with other p-transient and d-triangles regions to potentially form new core objects. Performing image segmentation based on topology and persistent homology guarantees several nice properties, and initial results demonstrate high quality image segmentation.
Rapid phosphorylation of microtubule-associated proteins through distinct mitogenic pathways

Mitogenic stimulation of sparse quiescent Swiss 3T3 cells with serum induces a transient reorganization of microtubules which may be necessary for generation or transduction of the mitogenic signal(s). Recently, several studies have shown that microtubule-associated proteins (MAPs) modulate microtubule-mediated functions in vitro and in vivo. We have analyzed, by two-dimensional electrophoresis, the molecular changes in MAPs associated with microtubules in situ following cell activation. By as early as 15 min after addition of serum, several of the MAPs present in quiescent cells are lost from the assembled microtubule fraction while one additional MAP becomes evident. This new MAP is a phosphoprotein whose appearance is independent of protein synthesis. Four additional MAPs also become phosphorylated, and this phosphorylation is accompanied by a partial redistribution of MAPs into the unassembled soluble fraction. Stimulation of cells with purified platelet-derived growth factor or phorbol tumor promoter, a direct activator of protein kinase C, also induces phosphorylation of the same MAPs and DNA synthesis. These results demonstrate that activation of the protein kinase C pathway is sufficient to promote the phosphorylation of MAPs and mitogenesis. However, epidermal growth factor, which does not activate protein kinase C, also stimulates phosphorylation of MAPs and DNA replication. Furthermore, down-regulation of the protein kinase C pathway does not prevent these responses. We conclude that phosphorylation of MAPs and mitogenesis can proceed through protein kinase C-dependent and -independent pathways in 3T3 cells.
Electron beam angiography of percutaneous atrial septal defect closure

A 39-year-old woman presented with complaints of shortness of breath on exertion and was found to have fixed splitting of the second heart sound and a systolic murmur. Electron beam angiography was performed prior to (Fig. 1A) and following (Fig. 1B) percutaneous closure. Balloon sizing (Amplatzer®‚ sizing balloon, AGA Medical Corp., Golden Valley, Minn., USA) showed a stretched diameter of 31 mm (Fig. 2C). Transesophageal echocardiography (Fig. 2A) showed an atrial septal defect 26 mm in size with adequate (>5 mm) rims in all quadrants except at the base of the aorta. A 34-mm Amplatzer Septal Occluder Device® (AGA Medical Corp.) was placed. Electron beam angiography provided an accurate assessment of defect size and excellent visualization of adjacent cardiac structures including the aortic valve and pulmonary veins. FIG. 2 (A) Transesophageal echocardiography (TEE) showing ASD 26 mm in size with absent anterior rim (arrow). (B) TEE following device placement. (C) Stretched defect of 31 mm using Amplatzer sizing balloon. (D) 34-mm Amplatzer Septal Occluder deployed across the ASD. FIG. 1 (A) Pre-closure axial electron beam angiography (EBA) image showing a large ostium secundum atrial septal defect (ASD) with absent anterior rim (arrowhead) and defect size of 30.45 mm. (B) Post-closure axial EBA showing 34 mm Amplatzer Septal Occluder Device. RA = right atrium, LA = left atrium, Ao = aorta, RV = right ventricle. (A)
Audio-Visual Speaker Recognition for Video Broadcast News

Audio-based speaker identification degrades severely when there is a mismatch between training and test conditions due either to channel or to noise. In this paper, we explore various techniques to combine video based speaker identification with audio-based speaker identification to improve the performance under mismatched conditions. Specifically, we explore techniques to optimally determine the relative weights of the independent decisions based on audio and video to achieve the best combination. Experiments on video broadcast news data show that significant improvements can be achieved by the fusion in acoustically degraded conditions.
Introduction: Food Rheology and Structure

By definition, rheology is the study of deformation and flow of matter. The science of rheology grew considerably due to research work done on synthetic polymers and their solutions in different solvents that in turn was necessary due to the many uses of the polymers (“plastics”) in day-to-day and industrial applications. Nevertheless, because of the biological nature of foods, food rheology offers many unique opportunities of study and there exists a large body of food rheology literature. Many foods are composed mainly of biopolymers and aqueous solutions containing dissolved sugars and ions. The former are large molecules, often called macromolecules, such as proteins, polysaccharides, and lipids from a wide range of plant and animal sources. In addition, water is an important component in many foods and plays a major role in the creation of edible structures and their storage stability (Rao, 2003). Processed foods may be viewed as edible structures that are created as a result of the responses of proteins, polysaccharides, and lipids in aqueous media to different processing methods, such as thermal processing, homogenization, and other physical treatments. Most, if not all, of those responses are physical in nature. The measured rheological responses are those at the macroscopic level. However, they are directly affected by the changes and properties at the microscopic level (Rao, 2006). Thus, it would be helpful to understand the role of structure of foods on their rheological behavior.
Mining surveillance video for independent motion detection

This paper addresses the special applications of data mining techniques in homeland defense. The problem targeted, which is frequently encountered in military/intelligence surveillance, is to mine a massive surveillance video database automatically collected to retrieve the shots containing independently moving targets. A novel solution to this problem is presented in this paper, which offers a completely qualitative approach to solving for the automatic independent motion detection problem directly from the compressed surveillance video in a faster than real-time mining performance. This approach is based on the linear system consistency analysis, and consequently is called QLS. Since the QLS approach only focuses on what exactly is necessary to compute a solution, it saves the computation to a minimum and achieves the efficacy to the maximum. Evaluations from real data show that QLS delivers effective mining performance at the achieved efficiency.
I Beg Your Pardon: A Call for Renewal of Executive Clemency and Accountability in Massachusetts

The pardon power, often described as a safety valve on the criminal justice system, is in a state of atrophy. Against a backdrop of “tough-on-crime” rhetoric, a systemic devaluation of rehabilitation efforts, and significant racial disparities in punishment, the disuse of clemency means no possibility of exit for those who have transformed themselves while incarcerated. This Note examines the origins, history, and philosophical underpinnings of clemency in the United States, focusing on the delicate balance between executive discretion and accountability. It then considers the structural and political factors that have contributed to the almost total failure of the clemency process in Massachusetts in recent years. The Note argues for the revitalization of executive clemency as a means of achieving optimal justice in individual criminal cases and system-wide, and it suggests changes to the administration of the clemency process in Massachusetts to achieve that end.
AIDS: A History

The AIDS epidemic transformed the lives of a generation of gay men and lesbians in ways that we could never have imagined. More than three decades after the first cases were evident, not one social, economic, political, and scientific institution in the world has escaped the impact of HIV/AIDS. What follows is a personal chronicle of my journey through the history of HIV, focusing on some of the issues that have transformed the lesbian, gay, bisexual, and transgender communities, and psychiatry and medicine. For those coming to consciousness after 1981, AIDS has always been part of the world. Younger people often do not know the history of the civil rights or the gay liberation movement. The HIV pandemic continues to plague the world's most vulnerable people. The obstacles most in the way of eradicating this virus include religious prohibitions against same sex behavior, poverty, lack of access to medical and mental health care. Medical science has transformed the infection from an acute, lethal disease t...
Dendrite morphogenesis depends on relative levels of NT-3/TrkC signaling

Neurotrophins regulate diverse aspects of neuronal development and plasticity, but their precise in vivo functions during neural circuit assembly in the central brain remain unclear. We show that the neurotrophin receptor tropomyosin-related kinase C (TrkC) is required for dendritic growth and branching of mouse cerebellar Purkinje cells. Sparse TrkC knockout reduced dendrite complexity, but global Purkinje cell knockout had no effect. Removal of the TrkC ligand neurotrophin-3 (NT-3) from cerebellar granule cells, which provide major afferent input to developing Purkinje cell dendrites, rescued the dendrite defects caused by sparse TrkC disruption in Purkinje cells. Our data demonstrate that NT-3 from presynaptic neurons (granule cells) is required for TrkC-dependent competitive dendrite morphogenesis in postsynaptic neurons (Purkinje cells)—a previously unknown mechanism of neural circuit development.
PSM/SH2-B distributes selected mitogenic receptor signals to distinct components in the PI3-kinase and MAP kinase signaling pathways

The Pro-rich, PH, and SH2 domain containing mitogenic signaling adapter PSM/SH2-B has been implicated as a cellular partner of various mitogenic receptor tyrosine kinases and related signaling mechanisms. Here, we report in a direct comparison of three peptide hormones, that PSM participates in the assembly of distinct mitogenic signaling complexes in response to insulin or IGF-I when compared to PDGF in cultured normal fibroblasts. The complex formed in response to insulin or IGF-I involves the respective peptide hormone receptor and presumably the established components leading to MAP kinase activation. However, our data suggest an alternative link from the PDGF receptor via PSM directly to MEK1/2 and consequently also to p44/42 activation, possibly through a scaffold protein. At least two PSM domains participate, the SH2 domain anticipated to link PSM to the respective receptor and the Pro-rich region in an association with an unidentified downstream component resulting in direct MEK1/2 and p44/42 regulation. The PDGF receptor signaling complex formed in response to PDGF involves PI 3-kinase in addition to the same components and interactions as described for insulin or IGF-I. PSM associates with PI 3-kinase via p85 and in addition the PSM PH domain participates in the regulation of PI 3-kinase activity, presumably through membrane interaction. In contrast, the PSM Pro-rich region appears to participate only in the MAP kinase signal. Both pathways contribute to the mitogenic response as shown by cell proliferation, survival, and focus formation. PSM regulates p38 MAP kinase activity in a pathway unrelated to the mitogenic response.
Resource Selection by Indiana Bats During the Maternity Season

Little information exists on resource selection by foraging Indiana bats (Myotis sodalis) during the maternity season. Existing studies are based on modest sample sizes because of the rarity of this endangered species and the difficulty of radio-tracking bats. Our objectives were to determine resource selection by foraging Indiana bats during the maternity season and to compare resource use between pregnant and lactating individuals. We used an information theoretic approach with discrete choice modeling based on telemetry data to evaluate our hypotheses that land cover, percent canopy cover, distance to water, and prescribed fire affected the relative probability a point was used by a foraging Indiana bat. We fit models for individual bats and a population-level model based on all individuals with a random factor to account for differences in sample size among individuals. We radio-tracked 29 individuals and found variation in resource selection among individuals. However, among individuals with the same supported covariates, the magnitude and direction of the covariates were similar. Eighteen bats selected areas with greater canopy closure and 5 of 6 bats that had areas burned by low-intensity prescribed fire in their home range selected burned areas. Resource selection was related to land cover for 13 individuals; they selected forest and shrubland over agricultural land, which composed >50% of the landscape within 10?km. We found no support for our hypothesis that resource selection was related to individual reproductive condition or Julian date in our population-level model indicating habitat selection was not determined by reproductive status or date within the maternity season. Land use or forest management that greatly reduces canopy cover may have a negative impact on Indiana bat use. Maintaining forest cover in agricultural landscapes is likely critical to persistence of maternity colonies in these landscapes. Sites managed with low severity prescribed fire may be selected by some individuals because of reduced understory vegetation.
FORMATION OF A NEW PHASE FROM CHEMICAL INTERACTIONS AT AN INTERFACE : NUCLEATION CONTROL

The phenomena to be considered here constitute a particular case of the general question of the formation of a new solid phase from a chemical interaction between two adjoining phases, one of which acting as a substrate should be solid also, while the second one can indifferently assume any physical state, solid, liquid or gaseous (as in oxidation). The conditions under which nucleation becomes the rate-determining process in such reactions are analyzed in terms of the classical theory of nucleation. Quite often the growth of the new phase is proportional to the square-root of time indicating diffusion control ; germination comes to play the preponderant role when the change in free energy ƊG is sufficiently small. When germination becomes very difficult, it may take place only at such high temperatures that diffusion ceases to play any significant role and the reaction assumes a quasi explosive character. While the presence of equilibrium points, eutectoid or oxide decomposition, provides the possibilty of making ƊG arbitrarily as small as desired, nucleation-control does not depend on such equilibrium points, the one necessary condition is that ƊG be small. Some practical aspects are considered.
A Min-Max Inventory Model

An inventory model is considered where every N periods an order is placed for an amount which brings the sum of stock-on-hand plus on-order up to some level S. The model treats a single item for which there is random demand. Demands that arrive when there is no positive inventory on hand are back-ordered. Leadtime is treated as random and the receipts of orders are allowed to cross in time. Values N* and S* which minimize steady state expected costs per unit time cannot be found. In this paper approximations, N0 and S0 are found. These are determined by minimizing an expected cost per unit time which has been maximized over all distributions of stock deficit with a given mean and variance. The method is applicable even when the functional form of the distribution of demand is not known. Computer simulations are used to indicate the values of the input parameters for which the expected costs per unit time associated with N0 and S0 are close to the similar quantities for N* and S*.
Retinal vein occlusion after trabeculectomy with mitomycin C.

Purpose To evaluate acute retinal vein occlusion as a potential complication of trabeculectomy with mitomycin C in cases of advanced glaucoma. Methods The records of three patients who developed retinal vein occlusions immediately after uncomplicated trabeculectomy with mitomycin C were reviewed. Results All three patients had advanced open-angle glaucoma with total cupping of the optic nerve, severe visual field loss, and evidence of systemic vascular disease. A marked decrease in intraocular pressure was noted in the postoperative period in all of the patients. Conclusion A shift in the lamina cribrosa, associated with the perioperative intraocular pressure change, may have contributed to occlusion of the venous outflow system in these susceptible patients.
Spherical means on compact Riemannian manifolds of negative curvature

Abstract We show that the spherical mean of functions on the unit tangent bundle of a compact manifold of negative curvature converges to a measure containing a vast amount of information about the asymptotic geometry of those manifolds. This measure is related to the unique invariant measure for the strong unstable foliation, as well as the Patterson-Sullivan measure at infinity. It turns out to be invariant under the geodesic flow if and only if the mean curvature of the horospheres is constant. We use this measure in the study of rigidity problems.
Characterization of Unique Modification of Flagellar Rod Protein FlgG by Campylobacter jejuni Lipid A Phosphoethanolamine Transferase, Linking Bacterial Locomotion and Antimicrobial Peptide Resistance

Gram-negative bacteria assemble complex surface structures that interface with the surrounding environment and are involved in pathogenesis. Recent work in Campylobacter jejuni identified a gene encoding a novel phosphoethanolamine (pEtN) transferase Cj0256, renamed EptC, that serves a dual role in modifying the flagellar rod protein, FlgG, and the lipid A domain of C. jejuni lipooligosaccharide with a pEtN residue. In this work, we characterize the unique post-translational pEtN modification of FlgG using collision-induced and electron transfer dissociation mass spectrometry, as well as a genetic approach using site-directed mutagenesis to determine the site of modification. Specifically, we show that FlgG is modified with pEtN at a single site (Thr75) by EptC and demonstrate enzyme specificity by showing that EptC is unable to modify other amino acids (e.g. serine and tyrosine). Using Campylobacter strains expressing site-directed FlgG mutants, we also show that defects in motility arise directly from the loss of pEtN modification of FlgG. Interestingly, alignments of FlgG from most epsilon proteobacteria reveal a conserved site of modification. Characterization of EptC and its enzymatic targets expands on the increasingly important field of prokaryotic post-translational modification of bacterial surface structures and the unidentified role they may play in pathogenesis.
Measurement of infinite dilution activity coefficients using high performance liquid chromatography

Abstract Economou, I.G., Vimalchand, P. and Donohue, M.D., 1991. Measurement of infinite dilution activity coefficients using high performance liquid chromatography. Fluid Phase Equilibria, 68: 131-149. High performance liquid chromatography (HPLC) was used to measure the distribution of several solutes between a stationary phase and a mobile phase. In all cases, the stationary phase was octadecane bonded to μPORASIL packing material. Mobile phases were aqueous solutions of methanol, ethanol, acetonitrile and isopropanol at several compositions. Solutes were benzene, toluene, p-xylene and cumene. These solutes show good partitioning between the two phases and are easily detected with a UV detector. Ratios of infinite dilution activity coefficients, γ∞, of these solutes in the mobile phases were then determined from the capacity factor k'. Values for the activity coefficients themselves can be obtained from these ratios if one absolute value is available. Our results compare well with values of γ∞ for the same systems obtained from the literature. Limitations of the method are discussed. Finally, experimental results are compared with predictions from UNIFAC, NRTL and APACT.
EFFECT OF SOLID SOLUTION ADDITIVES ON THE DENSIFICATION AND CREEP OF GRANULAR CERAMICS

Abstract The effect of solid solution additives on the densification and creep of granular ceramics was investigated for a model system consisting of CeO2 solid solutions with Y2O3 as the additive. In the sintering of powder compacts at 1150°C, the densification rate of CeO2 at a given density decreased significantly with increasing Y3+ concentration. The reduction in the densification rate reached a factor of ≈ 100 for a Y3+ concentration of 6 at.%. Creep of dense specimens was investigated at constant strain rates of 10−5 and 10−4 s−1 in air at 1200°C. After compensation for differences in grain size, the creep rate was also found to decrease significantly with increasing Y3+ concentration. If the creep rate is assumed to be controlled by a mechanism of grain boundary diffusion, then the magnitude of the decrease is in good agreement with that observed in the sintering experiments. The results strongly indicate that it may be possible to predict changes in the steady-state creep behavior from observed changes in the sintering behavior provided that matter transport occurs by the same mechanism. They also indicate that the solid solution approach may have considerable merit for controlling the creep resistance of rare earth oxides that commonly have a high solubility for many cations. © 1997 Acta Metallurgica Inc.
Two-color planar laser-induced fluorescence thermometry in aqueous solutions.

We demonstrate a two-color planar laser-induced fluorescence technique for obtaining two-dimensional temperature images in water. For this method, a pulsed Nd:YAG laser at 532 nm excites a solution of temperature-sensitive rhodamine 560 and temperature-insensitive sulforhodamine 640. The resulting emissions are optically separated through filters and detected via a charged-couple device (CCD) camera system. A ratio of the two images yields temperature images independent of incident irradiance. An uncertainty in temperature of ±1.4 °C is established at the 95% confidence interval.
When Work and Love Mix: Perceptions of Peers in Workplace Romances

Workplace romances are a contemporary and pervasive phenomenon with implications for interpersonal and organizational communication scholars. The present study aimed to discover how an organizational peer (male or female) dating another organizational member (another peer or superior) impacted employee perceptions of and responses to the peer. Full-time employees completed measures assessing communication and relational perceptions based on a 2 (peer sex) × 2 (status dynamic) design. Employees reported they would feel less solidarity and trust and were more likely to engage in information manipulation with a peer dating a superior compared to a peer dating another peer. In addition, trust in the peer mediated the relationships between peer's partner status and coworkers' solidarity and information manipulation with the peer. Peer sex and partner status also interacted to affect trust and solidarity.
Measurements of Skin Friction on the Wall of a Hypersonic Nozzle

Direct skin friction measurements obtained on the wall of a Mach 19.8 nozzle are presented. These measurements of skin friction and values deduced from the profile data are compared with predictions from a finite difference theory and also with several 'flat-plate' prediction methods for skin friction.
Perspectives On Spect

Single-photon emission computed tomography (SPECT) is an inverse problem in which one wants to determine the distribution of a radionuclide from a set of measured projections. Like most inverse problems, it is ill-posed and does not admit of an exact solution. In this paper we review various methods from the literature on inverse problems that are applicable to SPECT. Topics considered include the discrete representation of continuous objects, the intrinsic dimensionality of an object, null functions, the role of prior information, and various reconstruction principles, including maximum likelihood, least squares, and Bayesian methods.© (1986) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Indirect compensation techniques for three-stage fully-differential op-amps

As CMOS technology continues to evolve, the supply voltages are decreasing while at the same time the transistor threshold voltages are remaining relatively constant. Making matters worse, the inherent gain available from the nano-CMOS transistors is dropping. Traditional techniques for achieving high-gain by cascoding become less useful in nano-scale CMOS processes. Horizontal cascading (multi-stage) must be used in order to realize high-gain op-amps in low supply voltage processes. This paper discusses indirect compensation techniques for op-amps using split-length devices. A reversed-nested indirect compensated (RNIC) topology, employing double pole-zero cancellation, is illustrated for the design of three-stage op-amps. The RNIC topology is then extended to the design of three-stage fully-differential op-amps. Novel three-stage fully-differential gain-stage cascade structures are presented with efficient common mode feedback (CMFB) stabilization. Simulation results are presented for the designed RNIC fully-differential three-stage op-amps. The fully-differential three-stage op-amps, designed in 0.5 µm CMOS, typically exhibit 18 MHz unity-gain frequency, 82 dB open-loop DC gain, nearly 300 ns transient settling and 72° phase-margin for a 500 pF load.
The divalent cation dependence of liver glycogen synthase phosphatase activity

In a previous report it was shown that EDTA inhibition of liver glycogen synthase phosphatase activity in preparations from normal, fed rats could be increased upon glucagon or cAMP treatment. This occurred without a change in the half-maximum inhibitory concentration of EDTA. Glucose administration to animals resulted in decreased EDTA inhibition. The inhibitory action of EDTA has been further characterized by comparing its action with that of other chelators (CDTA and EGTA) and examining the effects of various divalent cations on chelator inhibition. Both CDTA and EDTA which differ structurally were inhibitory at 5 mm concentrations whereas EGTA which is structurally similar to EDTA was not inhibitory at concentrations up to 10 mm. The lack of inhibition by EGTA could be explained by its weak affinity for Mg++ in the preparation. A comparison of CDTA and EDTA revealed that CDTA was a more potent inhibitor than EDTA (I0.5, 0.15 mm vs 0.3 mm). Glucagon and glucose treatment of rats resulted in changes in CDTA inhibition which closely paralleled those of EDTA. A large group of divalent cations were tested but only Mg++, Ca++, and Mn++ both prevented and reversed CDTA or EDTA inhibition. Fifty percent reversal using either chelator occurred at calculated free-metal ion concentrations of approximately 2 µm, 0.08 µm and 0.0004 µm, respectively. Thus, it is clear that EDTA inhibition is due to its chelation effect and is not due to a nonspecific anionic effect.
Elective intestinal operations in infants and children without mechanical bowel preparation: a pilot study

Abstract Background/Purpose Preoperative mechanical bowel preparation (MBP) for elective intestinal operations has been a long accepted practice. However, MBP is often unpleasant and time-consuming for patients, and clinical trials in adults have not shown improved outcomes. We conducted this pilot study to test whether omitting MBP before elective intestinal operations in infants and children would increase the risk of infectious or anastomotic complications. Methods Retrospective review was performed of 143 patients who had an elective colon or distal small bowel procedure performed at our children's hospital between 1990 and 2003. Results Thirty-three patients (No PREP) were managed by a single surgeon who routinely omitted MBP, whereas another 110 patients (PREP) were prepared with enemas, laxatives, or both. Both groups received 24 hours of preoperative dietary restriction to clear liquids and perioperative parenteral antibiotics. The No PREP group had one anastomotic leak and no wound infections, whereas the PREP group had 2 anastomotic leaks and 1 wound infection ( P = .58). These results occurred despite greater duration of antibiotic therapy and incidence of delayed wound closures in the PREP group. Conclusion The results of this pilot study suggest that omitting MBP before elective intestinal operations in infants and children carries no increased risk of infectious or anastomotic complications. Eliminating MBP may reduce health care costs and inconvenience to patients. These findings warrant a large, prospective, randomized clinical trial to validate our findings and to investigate further the necessity of MBP in the pediatric population.
A synthetic iodinated polypeptide that inhibits polymerization of fibrinogen.

Synthetic iodopeptides exert a powerful anticoagulant activity. Data are presented that indicate the anticoagulant effect to be an inhibition of fibrin polymerization.
A temperature programmed desorption study of the H2O/V2O5 system

Abstract The interaction of water vapor with a polycrystalline V2O5 thin film (≅1 cm2) has been investigated by temperature programmed desorption (TPD). The desorption was studied at various H2O exposures including 50, 200, 400, and 720 L. From the TPD desorption spectra, it was found that water desorbed from the V2O5 surface at a temperature TM ≅ 390 K for a surface coverage θH2O ≅ 0.20 ML corresponding to 720 L. Dependence of TM on the surface coverage and the rate of desorption was noticed to increase with rise in H2O exposures. Second order desorption kinetics have been identified for the process with an activation energy E d $ 11.7 ± 0.2 kcal/mol . No molecular H2 was observed during H2O desorption from the V2O5 surace. A model based on dissociative adsorption of H2O and resultant recombinative desorption is proposed showing that the desorption proceeds from two adjacent vanadium sites, −V5+−O−V4+−.
Machine reasoning about anomalous sensor data

Abstract We describe a semantic data validation tool that is capable of observing incoming real-time sensor data and performing reasoning against a set of rules specific to the scientific domain to which the data belongs. Our software solution can produce a variety of different outcomes when a data anomaly or unexpected event is detected, ranging from simple flagging of data points, to data augmentation, to validation of proposed hypotheses that could explain the phenomenon. Hosted on the Jena Semantic Web Framework, the tool is completely domain-agnostic and is made domain-aware by reference to an ontology and Knowledge Base (KB) that together describe the key resources of the system being observed. The KB comprises ontologies for the sensor packages and for the domain; historical data from the network; concepts designed to guide discovery of internet resources unavailable in the local KB but relevant to reasoning about the anomaly; and a set of rules that represent domain expert knowledge of constraints on data from different kinds of instruments as well as rules that relate types of ecosystem events to properties of the ecosystem. We describe an instance of such a system that includes a sensor ontology, some rules describing coastal storm events and their consequences, and how we relate local data to external resources. We describe in some detail how a specific actual event—an unusually high chlorophyll reading—can be deduced by machine reasoning to be consistent with being caused by benthic diatom resuspension, consistent with being caused by an algal bloom, or both.
Understanding the impact of ionic liquid pretreatment on cellulose and lignin via thermochemical analysis

Abstract To date, there are few published reports on the fundamental physicochemical changes that occur in the biopolymers comprising lignocellulosic biomass during IL pretreatment. In particular changes to the degree of polymerization upon IL pretreatment although assumed have not been reported. In this study, we employ thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) to determine the impact of IL pretreatment on two of the primary biopolymers present in biomass – lignin and cellulose. IL pretreatment was carried out on technical biomass components (Avicel, Kraft lignin and low sulfonate alkali lignin) and on potential bioenergy feedstocks (switchgrass, pine and eucalyptus) at 120 and 160 °C for 1, 3, 6 and 12 h. The depolymerization and formation of lower molecular weight cellulose as a result of IL pretreatment were inferred from TGA/DSC results and were further confirmed by size exclusion chromatography (SEC). The results also confirm that there is a decrease in cellulose crystallinity in the biomass as a result of pretreatment. These results provide insight into the mode of depolymerization and breakdown of lignin and cellulose.
Characterizing, constructing and managing resource usage profiles of system S applications: challenges and experience

We describe the challenges of characterizing, constructing and managing the usage profiles of System S applications. A running System S application is a directed graph with software processing elements(PEs) as vertices and data streams as edges connecting the PEs. The resource usage of each PE is a critical input to the runtime scheduler for proper resource allocation. We represent the resource usage of PEs in terms of resource functions (RFs) that are used by the System S scheduler, with one RF per resource per PE. The first challenge is that it is difficult to build good RFs that can accurately predict the resource usage of a PE because the PEs perform arbitrary computations. A second set of challenges arises in managing the RFs and performance data so that we can apply them for PEs that are re-run or reused by the same or different applications or users. We report our experience in overcoming these challenges. Specifically, we present an empirical characterization of PE RFs from several real streaming applications running in a System S testbed. This indicates that our simple models of resource usage that build on the data-flow nature of the underlying application can be effective, even for complex PEs. To illustrate our methodology, we evaluate and analyze the performance of these applications as a function of the quality of our resource profile models. The system automatically learns the models from the raw metrics data collected from running PEs. We describe our approach to managing the metrics and RF models, which allows us to construct generalizable RFs and eliminates the learning time for new PEs by intelligently storing and reusing the metrics data.
Crystallization of Rhenium Salts in a Simulated Low‐Activity Waste Borosilicate Glass

This study presents a new method for looking at the solubility of volatile species in simulated low-activity waste glass. The present study looking at rhenium salts is also applicable to real applications involving radioactive technetium salts. In this synthesis method, oxide glass powder is mixed with the volatiles species, vacuum-sealed in a fused quartz ampoule, and then heat-treated under vacuum in a furnace. This technique restricts the volatile species to the headspace above the melt but still within the sealed ampoule, thus maximizing the volatile concentration in contact with the glass. Various techniques were used to measure the solubility of rhenium in glass and include energy dispersive spectroscopy, wavelength dispersive spectroscopy, laser ablation inductively-coupled plasma mass spectroscopy, and inductively-coupled plasma optical emission spectroscopy. The Re-solubility in this glass was determined to be ~3004 parts per million Re atoms. Above this concentration, the salts separated out of the melt as inclusions and as a low viscosity molten salt phase on top of the melt observed during and after cooling. This salt phase was analyzed with X-ray diffraction, scanning electron microscopy as well as some of the other aforementioned techniques and identified to be composed of alkali perrhenate and alkali sulfate.