cssi/SciSciGPT-SciSciNet huggingface dataset:
Computer-Assisted Data Collection

Computer-assisted data collection methods have been widely used in the government survey and market research industries but have not been as prominent in the clinical research setting, which relies heavily on the use of paper-based case report forms. In many clinical studies, respondents typically use paper forms to provide self-reported data for the study. These forms are then converted to electronic format by data-entry or clinical data management systems suitable for electronic data capture. Methods such as audio computer-assisted self-interviewing (A-CASI) and telephone audio computer-assisted self-interviewing (T-ACASI) may be particularly helpful in collecting high-quality patient-reported data, especially in Phase IV and postmarketing surveillance studies. This article introduces the primary considerations for using A-CASI or T-ACASI and provides insights into the management of data collected with these methods. It describes some of the advantages and data management efficiencies inherent in computer-assisted interviewing systems and concludes with specific examples of successful use of these approaches in clinical studies. Keywords: Computer-assisted interviewing; audio-CASI; electronic data capture; patient-reported outcomes
The Effects of Divorce on Young Adults' Relationship Competence

Abstract The relationship competence of young adults was investigated to determine if those who experienced family disruption in childhood, namely divorce or conflict, differed on measures of self esteem, fear of intimacy, romantic relationship satisfaction, and beliefs about marriage. The potential moderating effect and contribution of intimate friendships on relationship competence was examined. The study compared youth who had experienced family divorce with those youth who had not. A sample of male (n = 56) and female (n = 128) undergraduates participated in this study. The results indicated that parental divorce did not affect relationship competence, but that the level of perceived family conflict did influence the self esteem, fear of intimacy and romantic relationship satisfaction of young adults. Those who reported more conflict in their childhood families also reported more fear of intimacy, less self esteem and lower romantic relationship satisfaction than those who reported lower conflict in t...
Identifying Dynamic Replication Strategies for a High-Performance Data Grid

Dynamic replication can be used to reduce bandwidth consumption and access latency in high performance "data grids" where users require remote access to large files. Different replication strategies can be defined depending on when, where, and how replicas are created and destroyed. We describe a simulation framework that we have developed to enable comparative studies of alternative dynamic replication strategies. We present preliminary results obtained with this simulator, in which we evaluate the performance of five different replication strategies for three different kinds of access patterns. The data in ths scenario is read-only and so there are no consistency issues involved. The simulation results show that significant savings in latency and bandwidth can be obtained if the access patterns contain a small degree of geographical locality.
Union Must Provide Attorney Representation Without Regard to Union Membership--National Treasury Employees Union v. Federal Labor Relations Authority

The Federal Service Labor-Management Relations Statute sets forth union guidelines for collective bargaining representation in the federal sector. A labor organization with recognized exclusivity is responsible for the non-discriminatory representation of all bargaining unit employees without regard to union membership. In National Treasury Employees Union v. Federal Labor Relations Authority, a case of first impression, the court considered whether a federal employees union may, in accordance with statutory obligations, consider union membership in determining the type of representation it provides to individual employees. The court held that by denying non-union members attorney representation and substituting representation by a shop steward or chapter official, the National Treasury Employees Union (NTEU) committed an unfair labor practice and violated the duty of fair representation. This Article discusses the above case.
Nonlinear THz mixing in YBa 2 Cu 3 O 7 thin film hot electron bolometers

Small volume high-T c super-conducting YBa 2 Cu 3 O 7 (YBCO) thin films are used as low power, very wide bandwidth mixers in the frequency range of 75 GHz to 2.5 THz. The YBCO films are patterned into lattice-cooled hot-electron bolometers (HEB) coupled to an integrated Au thin-film antenna and transmission line. Near 77 K, these mixers have responsivity as high as 780 V/W using only 8 nW of local oscillator (LO) power at 585 GHz. The responsivity can be shown to be truly bolometric. Direct heterodyne and homodyne down-conversion mixing using local-oscillator frequencies of 75 GHz and 585 GHz show overall conversion gains of -35 dB, which includes a -18 dB coupling loss, using only approximately 1 (mu) W of LO power. The gain bandwidth shows a simple Lorentzian roll-off with -3 dB point of 5 to 8 GHz. The large gain bandwidth and small power requirements make these high-T c superconducting mixers an attractive alternative to existing Schottky diode and conventional superconducting receiver technologies.
Semiconductor modeling for multi-layer, high field, photo-switch using sub-bandgap photons

High electric field geometries for high power, photo-conductive switches made possible by employing sub-bandgap photons and inter-bandgap dopants / defects are being investigated for compact pulse power systems. The high field, long absorption depth package reduces the required linear mode, optical closure energy and also reduces the conduction current density through the active material and at the contacts. In addition, the long absorption depth package increases the area available for thermal management and in concert with the reduced current density should increase the lifetime of the switch. This paper describes the semiconductor physics modeling of a multi-layer stack of GaAs wafers in a high electric field configuration. The model results of heavily doped n+ regions on electron injection, leakage current, and voltage hold off is discussed In addition, the modeling of the transverse injection of optical closure energy is discussed.
Anthropometry in blacks: applicability of generalized skinfold equations and differences in fat patterning between blacks and whites

To test the accuracy of generalized skinfold (SF) equations in blacks and to compare fat patterning in black and white adults, percent body fat (%BF) was assessed in 90 blacks and 89 whites by deuterium oxide dilution (D2O) and by generalized SF equations [Durnin and Womersely (DW), and Jackson and Pollock and Jackson et al (JP)] by using two calipers (Lange and Holtain). In blacks, JP significantly underpredicted (2.95%) and DW overpredicted (1.74%) D2O %BF with the Lange caliper. With the Holtain caliper DW successfully predicted D2O %BF (r = 0.91, SEE = 3.8%). In whites, DW overpredicted D2O %BF more than in blacks (4.94% vs 1.74%). Lower triceps-subscapular and thigh-subscapular skinfold-thickness ratios in black females and lower suprailiac-subscapular ratios in black males and females were found. It was concluded that blacks may have more visceral and upper-body fat deposition.
Combining Quality of Service and Social Information for Ranking Services

In service-oriented computing, multiple services often exist to perform similar functions. In these situations, it is essential to have good ways for qualitatively ranking the services. In this paper, we present a new ranking method, ServiceRank, which considers quality of service aspects (such as response time and availability) as well as social perspectives of services (such as how they invoke each other via service composition). With this new ranking method, a service which provides good quality of service and is invoked more frequently by others is more trusted by the community and will be assigned a higher rank. ServiceRank has been implemented on SOAlive, a platform for creating and managing services and situational applications. We present experimental results which show noticeable differences between the quality of service of commonly used mapping services on the Web. We also demonstrate properties of ServiceRank by simulated experiments and analyze its performance on SOAlive.
The Spallation Neutron Source project

The SNS is a "joint-venture" project of five DOE National Laboratories, aimed at building the world's most powerful accelerator-based pulse spallation source. At its planned 2 MW operation, it will produce neutron fluxes at least a factor of ten greater than Rutherford Appleton Laboratory's ISIS, currently the world's leading spallation source. The current design of the SNS calls for 600 ns pulses of 1 GeV protons striking a liquid mercury target at a 60 Hz rate. Room-temperature and cryogenic moderators produce beams of slow neutrons suitable for materials research. Responsibility for system components is as follows: LBNL will provide the high-brightness H/sup -/ ion source, transport structures and a 2.5-MeV RFQ accelerator; Los Alamos will build linacs to bring the beam to the full energy of 1 GeV; Brookhaven will build the accumulator ring to compress the 1 ms linac pulse into the sharp pulse delivered to the target; /spl ap/1200 turns will be injected, storing 2/spl times/10/sup 14/ protons in the ring, which are extracted in a single turn; Oak Ridge will provide the mercury target systems and all conventional facilities; and Argonne and Oak Ridge are coordinating the design of at least 10 neutron-scattering instruments to be provided as the initial suite of experiment stations. The project is formally underway, having been approved and funded by DOE and the US Congress for a construction start in FY99. Neutron beams will be available for users in FY06.
A Diffusion Model with a Concentration-Dependent Diffusion Coefficient for Describing Water Movement in Legumes During Soaking

A mathematical model based on Fick's diffusion equation with a concentration-dependent diffusion coefficient was proposed to describe the absorption of water by legumes. The equation was solved by using a numerical scheme. Parameter study was performed. The model is capable of predicting sigmoidal-shaped water uptake curves common to many legumes. Differences are discussed between the surface resistance boundary condition used in this study and the radiation boundary condition widely used for dehydration calculations. The validity of using the proposed model to described the water uptake of legumes was verified by the good fit between the experimental and theoretical curves.
Toward a Practical Definition of Pediatric Insomnia

Compared with adult insomnia, pediatric insomnia is poorly studied and described. The evaluation and treatment of insomnia in children, unlike in adults, is complicated by the occurrence of developmental changes in sleep habits that blur the distinction between abnormal and normal sleep, the fact that caregivers rather than insomnia sufferers typically voice the complaint of insomnia, the interactions between a child's abnormal or normal sleep behaviors and the caregiver-dictated bedtime schedules and sleep practices, and the unique consequences of childhood insomnia on the family. This article describes the prevalence, clinical manifestations, and impact of childhood sleep disturbances and attempts to arrive at a practical definition of pediatric insomnia based on the criteria for insomnia in adults presented in the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders, Revised Fourth Edition. This definition is intended to facilitate the identification, diagnosis, and study of pediatric insomnia and to assist in determining when intervention is warranted. Ideally, the proposed criteria should comprise one component of a larger effort to increase the knowledge about and awareness of pediatric insomnia. The needs for scientific evaluation of diagnostic and treatment strategies; educational programs for pediatric patients, their families, and physicians; public awareness initiatives; and epidemiologic studies to delineate predictive factors and correlates of pediatric insomnia are compelling.
New aspects of polyamine biosynthesis in eukaryotic organisms.

Abstract Some recent advances in the mechanism and control of enzymes that catalyze the synthesis of spermidine and spermine in eukaryotes are discussed. Aspects of the production of aliphatic polyamines by mammalian reproductive organs and malignant tumors are also considered.
Advances and hold-ups in the study of structure, function and regulation of Cys-loop ligand-gated ion channels and receptors.

The Cys-loop receptor channels, including the nicotinic acetylcholine (nAChR), serotonin 5-HT3, GABAA, GABAC and glycine receptor channels, are widely expressed in the nervous system (both central and peripheral) where they regulate excitability and neurotransmitter release, as well as at the endplate where they induce neuromuscular contraction. Furthermore dysfunctions in these receptors are thought to be involved in a variety of diseases and disorders, including (but not limited to) Alzheimer's disease, Parkinson's disease, epilepsy, schizophrenia, myasthenic syndromes, depression and substance abuse. Presently the Cys-loop receptors serve as molecular targets for a variety of clinically important drugs, such as muscle relaxants, tranquillizers, anticonvulsants and anti-emetics. Thus, these receptors are presently critical targets for the development of therapeutics to treat a variety of neurological diseases and disorders.
Transcriptional reporters for genes activated by cell wall stress through a non‐catalytic mechanism involving Mpk1 and SBF

The Mpk1 MAP kinase of the cell wall integrity (CWI) signalling pathway induces transcription of the FKS2 gene in response to cell wall stress through a non-catalytic mechanism that involves stable association of Mpk1 with the Swi4 transcription factor. This dimeric complex binds to a Swi4 recognition site in the FKS2 promoter. The Swi6 transcription factor is also required to bind this ternary complex for transcription initiation to ensue. In this context, the Mlp1 pseudokinase serves a redundant function with Mpk1. We have identified three additional genes, CHA1, YLR042c and YKR013w, that are induced by cell wall stress through the same mechanism. We report on the behaviour of several promoter-lacZ reporter plasmids designed to detect cell wall stress transcription through this pathway.
Aneurysm wall composition may determine rupture risk and endovascular treatment failure.

Although size has emerged as a crude differentiator between high and low risk intracranial aneurysms, it remains an imperfect biomarker of aneurysm behavior (2). Clinicians are increasingly faced with the dilemma of counseling patients with small aneurysm against treatment, yet simultaneously struggling with the difficult care and prognosis of patients with equally small ruptured aneurysms (2). Deflation of aneurysms after rupture has been refuted as an explanation of this paradox (6). Although using aneurysm size may give some insight into individualized risk prediction it is far from the goal of precision medicine of providing patients with an accurate assessment of individualized risk. Vascular dysfunction of the aneurysm wall has been regarded as a potential target for finding more accurate biomarkers for disease behavior. Paucity or absence of smooth muscle cells have been noted in histologic studies of human aneurysm walls (3). Inflammation of the wall has been thought to be a strong potential pathway to eventual aneurysm rupture (4, 7). Although inflammation has been associated with aneurysm rupture, causation has not been clearly established. Furthermore the role of smooth muscle cell dysregulation or absence in this process remains poorly understood.
Central helix mutations in the centrosome-associated EF-hand protein centrin

Centrin is a unique member of the EF-hand superfamily that is found in calcium-modulated contractile fibers associated with the centrosomes in a wide variety of higher and lower eukaryotes. InChlamydomonas reinhardtii centrin is encoded by the genevfl 2. We previously showed that thevfl 2–220 mutation is a glutamic acid to lysine change at position 101 that results in the loss of the centrin-containing fibrous structures. Here we describe several phenotypic revertants of thevfl 2–220 mutation that carry second site suppressors at amino acid position 96 or 104. Even though these new mutations are able to suppress the variable flagellar number phenotype, they are not wild type at the ultrastractural level but instead show specific defects in their distal striated fibers and transition-region stellate fibers. The nucleus-basal body connectors are, however, functional, suggesting that the reversion of the variable flagellar number phenotype occurs through restoration of proper connections of the basal body apparatus to the nucleus, as has been previously proposed. Positions 96, 101, and 104 lie within centrin's central helix, indicating that, as is the case for calmodulin, this part of the protein is of particular importance to its function.
The fractal volume of the two-dimensional invasion percolation cluster

We consider both invasion percolation and standard Bernoulli bond percolation on theZ2 lattice. Denote byV andC the invasion cluster and the occupied cluster of the origin, respectively. Let\(\mathcal{V}_n = \mathcal{V} \cap [ - n, n]^2 \), and Open image in new window Let e>0 be given. Here we show that, with a probability tending to 1, $$n^{2 - \varepsilon } \pi _n \leqq |\mathcal{V}_n | \leqq n^{2 + \varepsilon } \pi _n .$$ Assuming the existence of an exponent 1/ρ for πn it can be seen that with probability tending to one $$n^{2 - 1/\rho - \varepsilon } \leqq |\mathcal{V}_n | \leqq n^{2 - 1/\rho + \varepsilon } .$$ Moreover, by den Nijs' and Nienhuis et al's computations, $$n^{1.8958389583... - \varepsilon } = n^{1 + \tfrac{{43}}{{48}} - \varepsilon } \leqq |\mathcal{V}_n | \leqq n^{1 + \tfrac{{43}}{{48}} - \varepsilon } = n^{1.8958389583... + \varepsilon } $$ with a probability tending to one. The result matches Wilkinson and Willemsen's numerical computation\(\mathcal{V}_n \sim n^{1.89} \). The method allows us also to show the same argument for any planar graph. Therefore, any two planar invasion clusters have the same fractal dimension 2−1/ρ if one believes “universality”.
Studies in histochemistry, LXXI. Measurement of protein in millimicrogram amounts by quenching of dye fluorescence

Abstract A study of conditions for the determination of protein, based on its effect in quenching the fluorescence of certain dyes, was made. A procedure was elaborated by which the quenching of the fluorescence of eosin Y provided a method for the determination of protein in the range of 0.1 to 20 mμg of protein-nitrogen per μl of sample solution (0.06–6 mμg/μl final solution measured) which gave a standard error of 2.6%.
Using a novel alternative to drug choice in a human laboratory model of a cocaine binge: A game of chance

Human laboratory studies have shown that, once initiated, cocaine self-administration is difficult to disrupt using non-drug alternatives. This inpatient study examined whether binge self-administration of cocaine could be altered by an immediate, non-drug reinforcer. Ten cocaine-dependent participants completed 5 consecutive laboratory session days with 2 sessions per day (a model binge), 9 days where cocaine was not available, and subsequent 2 laboratory session days where cocaine was again available (a second model binge). In each laboratory session, participants could choose to either self-administer smoked cocaine or play a game of chance by drawing a pre-determined number of balls from a bingo wheel. Balls were worth monetary amounts from $0 to $20. Participants' choice to smoke cocaine varied as a function of number of balls drawn. Thus, this game of chance served as an alternative reinforcer to smoking cocaine. Choice varied lawfully as a function of the number of opportunities to earn money indicating that an immediate behavioral alternative can reduce cocaine self-administration after initiation of use. The current model could be used to evaluate whether behavioral and pharmacological manipulations shift choice from cocaine to a non-drug alternative.
Investigation of students' reasoning regarding heat, work, and the first law of thermodynamics in an introductory calculus-based general physics course

Students in an introductory university physics course were found to share many substantial difficulties related to learning fundamental topics in thermal physics. Responses to written questions by 653 students in three separate courses were consistent with the results of detailed individual interviews with 32 students in a fourth course. Although most students seemed to acquire a reasonable grasp of the state-function concept, it was found that there was a widespread and persistent tendency to improperly over-generalize this concept to apply to both work and heat. A large majority of interviewed students thought that net work done or net heat absorbed by a system undergoing a cyclic process must be zero, and only 20% or fewer were able to make effective use of the first law of thermodynamics even after instruction. Students’ difficulties seemed to stem in part from the fact that heat, work, and internal energy share the same units. The results were consistent with those of previously published studies of students in the U.S. and Europe, but portray a pervasiveness of confusion regarding process-dependent quantities that has been previously unreported. Significant enhancements of current standard instruction may be required for students to master basic thermodynamic concepts.
Associative Cortex Features in the First Olfactory Brain Relay Station

Summary Synchronized firing of mitral cells (MCs) in the olfactory bulb (OB) has been hypothesized to help bind information together in olfactory cortex (OC). In this survey of synchronized firing by suspected MCs in awake, behaving vertebrates, we find the surprising result that synchronized firing conveys information on odor value ("Is it rewarded?") rather than odor identity ("What is the odor?"). We observed that as mice learned to discriminate between odors, synchronous firing responses to the rewarded and unrewarded odors became divergent. Furthermore, adrenergic blockage decreases the magnitude of odor divergence of synchronous trains, suggesting that MCs contribute to decision-making through adrenergic-modulated synchronized firing. Thus, in the olfactory system information on stimulus reward is found in MCs one synapse away from the sensory neuron.
Association of heat shock protein 90 with the 16 kDa steroid binding core fragment of rat glucocorticoid receptors.

Abstract We have recently described a 16 kDa steroid binding core (Thr537-Arg673) of the rat glucocorticoid receptor [Simons et al. (1989) J. Biol. Chem. 264, 14493–14497]. Sedimentation analysis and size exclusion and anion exchange chromatography now suggest that other proteins are associated with the 16 kDa receptor, just as has been seen for the intact 98 kDa receptor. The 16 kDa fragment was also immunoprecipitable with anti-heat shock protein 90 (hsp90) antibody. These results argue that hsp90 binds to the 16 kDa core fragment and directly position the site of hsp90 association between Thr537 and Arg673 of the rat glucocorticoid receptor.
The role of crystallinity on differential attachment/proliferation of osteoblasts and fibroblasts on poly(caprolactone-co-glycolide) polymeric surfaces

The objective of the present study is to systematically evaluate the role of polymer crystallinity on fibroblast and osteoblast adhesion and proliferation using a series of poly(caprolactone-co-glycolide) (PCL/PGA) polymers. PCL/PGA polymers were selected since they reflect both highly crystalline and amorphous materials. PCL/PGA polymeric materials were fabricated by compression molding into thin films. Five compositions, from PCL or PGA to intermediate copolymeric compositions of PCL/PGA in ratios of 25:75, 35:65 and 45:55, were studied. Pure PCL and PGA represented the crystalline materials while the copolymers were amorphous. The polymers/copolymers were characterized using DSC to assess crystallinity, contact angle measurement for hydrophobicity, and AFM for nanotopography. The PCL/PGA films demonstrated similar hydrophobicity and nanotopography whereas they differed significantly in crystallinity. Cell adhesion to and proliferation on PCL/PGA films and proliferation studies were performed using osteoblasts and NIH-3T3 fibroblasts. It was observed that highly crystalline and rigid PCL and PGA surfaces were significantly more efficient in supporting fibroblast growth, whereas amorphous/flexible PCL/PGA 35:65 was significantly more efficient in supporting growth of osteoblasts. This study demonstrated that while chemical composition, hydrophobicity and surface roughness of PCL/PGA polymers were held constant, crystallinity and rigidity of PCL/PGA played major roles in determining cell responses.
Diode laser measurements of HF concentrations from heptane/air pan fires extinguished by FE-36 and FE-36 plus ammonium polyphosphate

Tunable diode laser absorption spectroscopy is used to measure the time evolution of hydrogen fluoride concentrations produce from a series of enclosed heptane/air pan fires extinguished by FE-36 or FE-36 plus ammonium polyphosphate (APP). Recent advances in room temperature fiber coupled, near-IR diode lasers provide isolation of the laser and signal processing electronics from the hostile sampling site. For the fires studied, the change in HF gas concentration with time is dependent upon the fire fighting chemical used to extinguish the fire. The presence of APP is observed to accelerate the dissipation of HF from the fire enclosure. Visible attenuation spectroscopy is also used to measure the amount of light attenuation that occurs as a hand held fire extinguisher containing powder fire fighting agents released in the crew space of a M1-Abrams land combat vehicle. Obscuration test demonstrate that release of APP from extinguishers in an occupied space does not present a visibility challenge to the vehicle personnel.
Concavity in a vintage capital model with nonlinear utility

An optimization problem in an economic vintage capital model with nonlinear utility is investigated. It is described by non-linear Volterra integral equations with an unknown in the limits of integration. The concavity of the problem is proven, the condition for an extremum is established, and their relevance to applications is demonstrated.
Vehicle Detection by Independent Parts for Urban Driver Assistance

In this paper, we introduce vehicle detection by independent parts (VDIP) for urban driver assistance. In urban environments, vehicles appear in a variety of orientations, i.e., oncoming, preceding, and sideview. Additionally, partial vehicle occlusions are common at intersections, during entry and exit from the camera's field of view, or due to scene clutter. VDIP provides a lightweight robust framework for detecting oncoming, preceding, sideview, and partially occluded vehicles in urban driving. In this paper, we use active learning to train independent-part detectors. A semisupervised approach is used for training part-matching classification, which forms sideview vehicles from independently detected parts. The hierarchical learning process yields VDIP, featuring efficient evaluation and robust performance. Parts and vehicles are tracked using Kalman filtering. The fully implemented system is lightweight and runs in real time. Extensive quantitative analysis on real-world on-road data sets is provided.
A Critique of Three “Economics” Arguments Commonly Used to Influence Fishery Allocations

Abstract Three familiar “economics” arguments commonly used by commercial fishermen and anglers to influence fishery allocations are specious in the context of fishery valuation. What I call the “market argument” and the “revenues argument” are based on incorrect notions of economic value and are focused on purely financial matters such as expenditures and revenues instead of on consumer and producer surpluses. In contrast, the “cumulative-value argument” sometimes addresses correct notions of economic value, but the values of commercial and sport fisheries are not properly compared. A conceptually correct benefit–cost analysis of allocation between the two fisheries is illustrated.
Apparent changes in mouse liver DNA content due to interference by non-DNA diphenylamine-reacting cytoplasmic material.

Abstract A significant decrease occurs in the amount of diphenylamine-reacting material extracted with a nucleic acid fraction of liver if rats or mice are deprived of food for several days. However, this decrease, which is rapidly regained on refeeding the animals, does not represent loss of liver DNA, for no corresponding decrease was found if DNA was assayed by phosphate content or ultraviolet absorbance. The interfering material, which is predominantly cytoplasmic, yields a colored product in the diphenylamine reaction, resembling that given by deoxyribose but having an absorbance maximum at about 660 mμ rather than at 600 mμ. Also, the rate of color development with the interfering substance is slower than that observed with deoxyribose.
Desert grassland dynamics estimated from carbon isotopes in grass phytoliths and soil organic matter.

. We document the potential for using carbon isotopes in both soil organic matter (SOM) and grass phytoliths in soil to increase the temporal and taxonomic resolutions of long term vegetation dynamics. Carbon isotope values from both SOM and phytoliths are expected to describe both the age of material through 14C dating, and the photosynthetic pathway of the source plant material through ratios of 12C/13C. Taxonomic resolution is increased because the phytoliths examined are specific to grasses, whereas the SOM reflects the contribution of all the vegetation. Temporal resolution is increased because phytoliths are less mobile in the soil profile than SOM, and can therefore provide older dates from the same soil depth. Our results, from a desert grassland site in southwestern North America, largely confirm these expectations, and show that C4 species have dominated the grass composition for the last 8000 yr, C3 non-grass vegetation increased about 100–350 yrBP, and no significant C3 grass or non-grass vegetation existed between 350–2000 yr BP.
The Pharmacologic Treatment of Depression

Background. Family physicians often provide the first line of treatment for patients with depression. Many effective drugs are now available for the pharmacologic treatment of depression. Methods: We searched MEDLINE from 1991-96 under the topics of depressive disorders/treatment and antidepressant medications. Other sources were found by back-referencing from these references and from pharmacology texts. Results: Although antidepressants appear to be equally effective, selective serotonin reuptake inhibitors are frequently the drugs of choice because of their safety profile and less troublesome side effects. Conclusions: When prescribing antidepressant medications, the clinician must educate patients about potential side effects and about the amount of time that must be allowed for therapeutic efficacy. Drug interactions and concurrent medical conditions are important factors in the choice of an antidepressant.
Grain-scale permeabilities of texturally equilibrated, monomineralic rocks

Permeability (k) was measured on synthetic, monomineralic aggregates of quartz and calcite, which serve as analogs for texturally equilibrated, fluid- and melt-bearing rocks such as those in the deep crust and mantle. Porous quartzites were synthesized in the presence of silica-saturated H2O and H2O + NaCl, at 850°C and 1.4 GPa. Permeabilities, measured at near-atmospheric conditions on the quenched samples and scaled to a common grain-diameter (d), increase systematically by about four orders of magnitude as fluid fraction (φ) increases from 0.006 to 0.170. In this range, the k–φ relation can be approximated by the equation k=d2φ3/200. We were not able to determine permeabilities at fluid fractions lower than 0.006 (due to microfractures that formed during depressurization), but we expect the same relation — possibly with a slightly lower exponent on φ — to apply. Permeabilities measured on porous marbles, synthesized at 800°C and 1.0 GPa in the presence of H2O, are lower than values measured on quartzites for a given fluid fraction. At φ>0.027, an equation similar to that which applies to quartzites can be used to describe the k–φ relation, but using (φ−0.015) in place of φ. The lower permeability of the calcite aggregates reflects the fact that not all grain edges are `wetted', and thus some fraction of fluid is present in isolated pores. The `critical' fluid fraction below which all pores are isolated and k is zero lies somewhere between 0.005 and 0.027. Our measured permeabilities closely approximate values predicted by numerical modeling of fluid flow in texturally equilibrated rocks. This correspondence is somewhat surprising, considering that fluid distribution in our samples, and in real rocks, is much more complex than assumed in the numerical models. Assumptions implicit in numerical models — simple grain shape, a single grain size, non-rational crystal faces, and isotropic surface energies — do not apply to natural or synthetic texturally equilibrated rocks. Despite differences in fluid distribution, the similarity of k–φ relations indicates that average length and cross-sectional area of grain-edge channels is the same in a texturally equilibrated rock as it is in a hypothetical rock with uniform pore geometry.
A randomized, controlled trial of two-thumb vs two-finger chest compression in a swine infant model of cardiac arrest [see comment].

Background. The American Heart Association (AHA) currently recommends two-finger (TF) chest compression for infants. A previous study demonstrated that two-thumb (TT) with lateral chest wall compression provided significantly higher arterial pressures than did the TF method. Limitations of that study included the lack of an asphyxial model and nonstandardized compression forces.objective. To test the hypothesis that TT chest compression generates higher arterial pressures than does the TF method, using an asphyxial model. Also, by standardizing sternal compression force (SCF), the authors sought to show that the increased pressures are the result of thoracic compression.Method. The study was a randomized, crossover trial in immature swine weighing 10 kg. Each swine was sedated, anesthetized, paralyzed, intubated, and mechanically ventilated on room air. A femoral arterial catheter was placed. Cardiac arrest was induced by asphyxiation and verified by ECG and pressure tracings. Eleven AHA-certified basic r...
Echocardiographic features of carcinoid heart disease

We reviewed the records of the Mayo Clinic patients with known carcinoid syndrome in whom echocardiographic studies had been done. Nineteen patients had M-mode and 2-dimensional echocardiographic examinations, and 1 patient had an M-mode examination only. Of the 20 patients, 8 had no evidence by echocardiogram of carcinoid heart disease; 2 had changes in the tricuspid valve echogram suggestive of early carcinoid heart disease, and the other 10 patients had the following distinctive echocardiographic findings: (1) the pattern of right ventricular volume overload (enlarged right ventricle with abnormal septal motion); (2) abnormal right-sided valves, including (a) a striking appearance of the tricuspid valve, the leaflets appearing thickened, retracted, and fixed in a semiopen position throughout the cardiac cycle, and (b) thickened, retracted pulmonic valve cusps, when visualized; and (3) the left-sided valves and chambers rarely involved. These echocardiographic features are distinctive of advanced carcinoid heart disease and correlate closely with pathologic findings.
PCBs AND TCDD, Alone And In Mixtures, Modulate Marine Mammal But Not B6C3F1 Mouse Leukocyte Phagocytosis

Increasing evidence has supported the general hypothesis that organochlorines (OC) can produce immunotoxic effects in marine mammals. One important innate defense mechanism is phagocytosis, the ability of cells to ingest extracellular macromolecules. The present study is aimed at characterizing the immunomodulatory potential of mixtures of OCs on phagocytosis compared to that of individual compounds in different species of marine mammals and mice, the traditional model to study mammalian immunotoxicity. The ability of peripheral blood neutrophils and monocytes to engulf fluorescent microspheres was evaluated using flow cytometry. The immunomodulatory effects of three non-coplanar polychlorinated biphenyl (PCB) congeners, 138, 153, 180, one coplanar PCB, 169, as well as 2,3,7,8-TCDD, and all possible mixtures (26) were tested upon in vitro exposure. All species were not equally sensitive to the adverse effects of OCs on either neutrophils or monocytes phagocytosis. With the exception of harbor seals, all m...
Telescope Simulator for the Nexus Wavefront Control Testbed

A telescope simulator was built as part of the Nexus wavefront control testbed, an NGST technology experiment at NASA's Goddard Space Flight Center. This testbed was designed to demonstrate complete control of a segmented telescope, from initial capture of light, through coarse alignment and phasing, to fine phasing and wavefront control. The existing telescope simulator allows testing of the fine phasing and wavefront control steps. A small deformable mirror in the simulator allows generation of an unobscured aberrated wavefront, for use in exploring the range of measurement and correction using the testbed's image-based wavefront sensor and larger deformable mirror. An alternate path under development for the simulator will create a segmented wavefront using three spherical mirrors; three-degree-of-freedom mounts under each mirror enable alignment and phasing experiments that will cover most of the operation sequence. Details of the hardware design and performance will be presented.
User interface design: are human factors principles used?

In the days when computer systems were used primarily by people with technical backgrounds, human factors, if considered at all, were treated as a backroom activity---something to be done after the design and implementation had been completed. We are now in an era in which computer hardware and software are consumer items. Computer users range from school kids to adults and from non-technical office professionals to software engineers. In today's environment, computer companies, especially those who sell software, must offer products that are effective and easy to use to be successful in the marketplace.
Therapies with Diverse Mechanisms of Action Kill Cells by a Similar Exponential Process in Advanced Cancers

Successful cancer treatments are generally defined as those that decrease tumor quantity. In many cases, this decrease occurs exponentially, with deviations from a strict exponential being attributed to a growing fraction of drug-resistant cells. Deviations from an exponential decrease in tumor quantity can also be expected if drugs have a nonuniform spatial distribution inside the tumor, for example, because of interstitial pressure inside the tumor. Here, we examine theoretically different models of cell killing and analyze data from clinical trials based on these models. We show that the best description of clinical outcomes is by first-order kinetics with exponential decrease of tumor quantity. We analyzed the total tumor quantity in a diverse group of clinical trials with various cancers during the administration of different classes of anticancer agents and in all cases observed that the models that best fit the data describe the decrease of the sensitive tumor fraction exponentially. The exponential decrease suggests that all drug-sensitive cancer cells have a single rate-limiting step on the path to cell death. If there are intermediate steps in the path to cell death, they are not rate limiting in the observational time scale utilized in clinical trials--tumor restaging at 6- to 8-week intervals. On shorter time scales, there might be intermediate steps, but the rate-limiting step is the same. Our analysis, thus, points to a common pathway to cell death for cancer cells in patients. See all articles in this Cancer Research section, "Physics in Cancer Research."
Application of extended energy loss fine structure in determining the structure of amorphous SiO2

Abstract The application of extended energy loss fine structure (EXELFS) in an electron energy loss spectrum is demonstrated for the determination of the element-specific local structure. EXELFS, the electron analogue of extended X-ray absorption fine structure, is particularly appropriate for lighter elements. EXELFS spectra are obtained by using a magnetic-prism spectrometer and a parallel electron energy loss detector attached to a dedicated scanning transmission electron microscope. The specimen is illuminated by a 100 keV electron beam from a cold field-emission gun. Electron-energy-loss spectra are acquired using a defocused electron probe to minimize beam damage. Oxygen and silicon K-edges of a magnetron-sputtered amorphous SiO 2 film were analyzed with in-house software, which extracts oscillatory components and calculates the partial radial distribution functions by a Fourier-transform method. The results are in good agreement with those obtained by X-ray methods.
Flavonoid constituents of Cicer arietinum

Abstract Chana seedlings ( Cicer arietinum ) have been found to contain the known compounds isoliquiritigenin, isoliquiritigenin-4′-glucoside, 4′,7-dihydroxyflavonol, daidzein, pratensein, and p -coumaric acid; and the hitherto unreported 4′,7-dihydroxyflavanon-3-ol (garbanzol) and biochanin-7-glucoside, both of which have been synthesized. Radioactive garbanzol is metabolized by chana seedlings as shown by its conversion into garbanzol-7-glucoside and 4′,7-dihydroxyflavonol, but formononetin was not labeled.
Genetic Mapping of a Macromutation and Quantitative Trait Loci underlying Fatty Acid Composition Differences in Meadowfoam Oil

The seed oil of meadowfoam (Limnanthes alba Hartw. ex Benth.) is a rich source of very long-chain fatty acids (VLCs), primarily 20:1Δ5, 22:1Δ5, 22:1Δ13 (erucic acid), and 22:2Δ5Δ13 (dienoic acid). Wild-type L. alba ssp. versicolor populations produce more erucic and less dienoic acid than wild-type L. alba ssp. alba populations, phenotypic differences that are caused by the macromutation E and possibly by quantitative trait loci (QTL). The aim of this study was to map the E locus and QTL affecting fatty acid concentrations among intersubspecific backcross progeny. The segregation ratio for the E locus (94 Ee to 86 ee progeny) was not significantly different from one to one (P = 0.84). The E locus was associated with 94 and 77% of the phenotypic variance for erucic and dienoic acid concentration, respectively. Erucic acid varied from 42 to 151 g kg -1 among Ee and 185 to 269 g kg -1 among ee progeny, while dienoic acid varied from 151 to 318 g kg -1 among Ee and 66 to 209 g kg -1 among ee progeny. The E locus mapped to Linkage Group 4 and pleiotropically affected every VLC. Composite interval mapping, performed with the E locus and IS background markers as cofactors, was used to search the genome for QTL. Two significant QTL peaks were found for erucic and dienoic acid on Linkage Group 4. One QTL was centered on the E locus and produced a massive peak. The other QTL produced a marginally significant peak 30.4 cM downstream of the E locus and was associated with less than 1% of the phenotypic variance. The segregation of additional QTL in this population affecting dienoic acid cannot be ruled out.
Infrastructure Development for Mathematical Modeling the Mechanics of Legged Locomotion

Legged locomotion of robotic systems on natural or man-made terrain is a complex, hybrid dynamics phenomenon. Effective design and control of these robots requires mathematical understanding of the system dynamics and exploration over a large design space for feasible design solutions. We are working on the development of a high-fidelity, multi-resolution mathematical modeling infrastructure to study the mechanics of legged locomotion. In this paper, we report some of the recent developments made in our effort. We report the implementation of (i) a multi-rigid body dynamics simulator based on cutting edge algorithms in computational multibody dynamics, (ii) a visualization engine that integrates with the dynamics simulator for real-time visualization of the CAD parts of generic multibody systems, (iii) integration and functionality of the coupled entity of the dynamics simulator and the visualization engine as a stand alone application and (iv) our investigations into massively parallel granular media modeling for ab-initio modeling of the contact mechanics of mobility platforms interacting with natural terrain.Copyright © 2011 by ASME
Relating Qualitative Analysis to Equilibrium Principles

Qualitative analysis in the general chemistry laboratory provides an excellent opportunity to help students make connections between ionic equilibrium topics covered in the lecture course and physical reality. Although laboratory manuals generally provide ample discussion of the equilibrium principles upon which the procedures are based, students' attention tends to be focused mostly on techniques, the reactions involved, and physical observations. A lack of understanding of the underlying principles often results in students being unable to make simple modifications to the procedure. This Mathcad document is intended to be used in a prelab activity for qualitative analysis experiments (based on modules ANAL364-366 of the Modular Laboratory Program in Chemistry, Palmyra, PA 17078), which are done toward the end of the general chemistry laboratory course at Nicholls State University. Mathcad is introduced at the beginning of the course and is routinely used throughout the semester for data analysis; handouts for these activities are available. The students are therefore quite competent in Mathcad by the time this activity is conducted. Students are given an incomplete Mathcad document (Qual6.mcd), which they complete as they explore the subject. An exemplary, completed document is available for instructors (Qual6a.mcd).
Impact of Film-Cooling Jets on Turbine Aerodynamic Losses

This paper documents a computational investigation of the aerodynamic impact of film cooling on a linear turbine airfoil cascade. The simulations were for single row injection on both the pressure and suction surfaces, downstream of the leading edge region. The cases match experimental efforts previously documented in the open literature. Results were obtained for density ratio equal to 1.0 and 2.0, and a blowing ratio range from 0.91 to 6.6. The domain included the passage flow as well as the film-hole and blade interior. The simulation used a dense, high-quality, unstructured hybrid–topology grid, comprised of hexahedra, tetrahedra, prisms and pyramids. The processing was performed with a pressure-correction solution procedure and a second–order discretization scheme. Turbulence closure was obtained using standard, RNG, and “realizable” k-e models, as well as a Reynolds stress model. Results were compared to experimental data in terms of total pressure loss downstream of the blade row. Flow mechanisms responsible for the variation of aerodynamic losses due to suction and pressure surface coolant injection are documented. The results demonstrate that computational methods can be used to accurately predict losses on film–cooled airfoils.Copyright © 1999 by ASME