cssi/SciSciGPT-SciSciNet huggingface dataset:
Sociability leads to instability

We present a general stochastic model showing that colonial breeding can lead to complex multi-colony population dynamics when combined with nothing more than (inevitably) imperfect decision-making by individuals. In particular, frequent “switching cascades”—mass movement of individuals between locations from one breeding season to the next—arise naturally from our model, bringing into question the need to invoke a separate, fitness-based explanation for this commonly observed real-world phenomenon. A key component of the model is the development, at the beginning of each breeding season, of a set of colonies, based on sequential choices by individuals about where to breed. Individuals favor the colony they bred in previously, but are also attracted to colonies that are rapidly establishing, and may switch locations. This provides a positive feedback that leads to switching cascades. We examine the effect on the dynamics of individuals’ access to (and ability to act on) information, as well as the overall size of the colony system and of individual colonies. We compare the model’s dynamics to the observed population dynamics of a set of heron and egret breeding colonies in New York Harbor.
Salmonella: A postmodern pathogen

The reported incidence of Salmonella infections in the United States has increased substantially since reporting began in 1943. These infections cause important morbidity, mortality, and economic burden in this country and are particularly severe in the infant, elderly, or immunocompromised patient. Four recent trends suggest that salmonellosis will present an increasing challenge to public health in the future. Antimicrobial resistance is present in an increasing proportion of Salmonella isolates. Salmonella bacteremia has emerged as a serious complication of human immunodeficiency virus infection. Infections caused by the egg-associated serotype Salmonella enteritidis are steadily increasing in incidence and geographic scope, and these infections are now the most common form of salmonellosis in some parts of the country. Finally, contamination of food produced in centralized facilities has led to extremely large and widespread outbreaks. Better understanding of the biology of specific animal reservoirs and of the microbiologic aspects of food processing is needed to control salmonellosis in the future.
A passion for terahertz optoelectronics

THz time-domain spectroscopy is a direct extension of ultrafast optoelectronics. The major components of THz time-domain spectroscopy include a laser, a THz emitter and detector, focusing and collimating components for both the laser and the THz optics, samples, a chopper, a motorized delay line, a lock-in amplifier, and a data acquisition system. The femtosecond laser pulses are divided into pump pulses used to generate single-cycle 1-ps bursts of THz radiation The THz pulses and probe pulses arrive simultaneously at an electro-optic sampling detection system, consisting of an EO crystal, a quarter waveplate, a Wallaston prism, and a pair of balanced photodiodes.
The chinese ring: a contraceptive intrauterine device.

The stainless steel ring (SSR; Figure 1) is a commonly used Chinese intrauterine device (IUD) that has a typical appearance when shown on sonography. Considering the large number of Chinese immigrants coming to the UnitedStates and the 2.7 million Chinese-born immigrants currently living here, it is not surprising that many family practitioners, obstetricians, sonographers, and sonologists will see the SSR at some point in their careers. 1 General knowledge about the effectiveness, risks, and sonographic appearance of the SSR is important for physicians who may encounter this particular IUD in their practices. To the best of our knowledge, no previous reports of the sonographic appearance of the SSR have been reported in the English language imaging literature.
Role of transcriptional repressors in transformation by bovine papillomavirus type 1.

Abstract Transformation of rodent cells by bovine papillomavirus type 1 (BPV-1) has been shown to require the direct contribution of the viral oncogenes encoded by the E5, E6, and E7 translational open reading frames (ORFs). It is also known that the viral E1 and E2 ORFs contribute indirectly to cellular transformation through their transcriptional modulation of these viral oncogenes. A mutant BPV-1 disrupted in two of the proteins encoded by the E2 ORF, the E2 transcriptional repressors, has a complex transformation phenotype. In this paper, we provide evidence that (i) this phenotype is not attributable to the absence of other viral genes that overlap the E2 repressor genes, (ii) the acquisition of transformation over time in cells harboring the E2 double-repressor mutant correlates with reversions of the mutations that disrupt one of the E2 repressor genes, E8/E2TR, and (iii) the initial transformation defect in the E2 double-repressor mutant can be rescued by disruption of the full-length protein encoded by the E1 ORF, the E1 transcriptional repressor. We propose a model by which the combination of E1 and E2 transcriptional repressors functions to modulate the transforming capacity of the virus.
Biochemical characterization of Pkn2, a protein Ser/Thr kinase from Myxococcus xanthus, a Gram-negative developmental bacterium

Pkn2, a protein Ser/Thr kinase, from the developmental bacterium Myxococcus xanthus was expressed under a T7 promoter in Escherichia coli and purified. Purified Pkn2 retained the autophosphorylation activity with the Km value of 177 microM for ATP and 73 nmol/min/mg for Vmax. The optimum pH and temperature were determined to be 7.5 and 35 degrees C, respectively. The autophosphorylation activity was inhibited by staurosporine with the IC50 value of 400 nM while H-7 and genistein had little effect on this kinase. Pkn2 appears to be unique for its higher manganese dependence. This is the first biochemical characterization of the prokaryotic protein Ser/Thr kinase.
Historical and current perspectives on Clostridium botulinum diversity

For nearly one hundred years, researchers have attempted to categorize botulinum neurotoxin-producing clostridia and the toxins that they produce according to biochemical characterizations, serological comparisons, and genetic analyses. Throughout this period the bacteria and their toxins have defied such attempts at categorization. Below is a description of both historic and current Clostridium botulinum strain and neurotoxin information that illustrates how each new finding has significantly added to the knowledge of the botulinum neurotoxin-containing clostridia and their diversity.
Some Physical Properties of Milk. II. Effects of Age upon the Viscosity of Pasteurized Whole Milk

Summary A slightly modified Ostwald viscometer is described with which small but definite differences in the viscosity of milk were measured. The increases in viscosity of both nonhomogenized and homogenized pasteurized milk measured at temperatures ranging from 4° to 44° C. as a result of aging or storage of the milk at 4° C. were found to be approximately a linear function of the logarithm of the age. A chart is presented by which the viscosity of milk containing 4.0 ± 0.05% fat and 13.0 ± 0.10% total solids and pasteurized at 62° C. for 30 minutes can be estimated from a known viscosity value at any known age within the age range of 0 to 300 hours. Similar charts can be prepared for milk of different composition and pretreatment.
Cytochrome P-450 Monooxygenase Systems in Aquatic Species: Carcinogen Metabolism and Biomarkers for Carcinogen and Pollutant Exposure

High levels of polynuclear aromatic hydrocarbon (PAH) carcinogens commonly occur in aquatic systems where neoplasms arise in fish and other animals. Enzymes that transform PAHs can act in initiatin...
Effect of helium in helium headspace carbon dioxide cylinders on packed-column supercritical fluid chromatography.

Supercritical fluid chromatography of PAHs was performed with pure carbon dioxide and helium headspace carbon dioxide at various cylinder fill levels. The retention times of the PAHs increased when helium headspace carbon dioxide was used as a carrier fluid relative to pure carbon dioxide. The increased retention times were affected by the level of the liquid phase present in the helium headspace carbon dioxide cylinder. As more liquid phase was removed from the cylinder, the effect of helium on the solvating power of CO2 was reduced because the relative amount of helium dissolved in the liquid phase decreased. Furthermore, the effect of helium headspace carbon dioxide was investigated with methanol-modified carbon dioxide mobile phases for the analysis of steroids. We observed that the relative solubility of helium in carbon dioxide resulted in longer retention times when compared to pure carbon dioxide as the liquid level of carbon dioxide decreased.
Binding of inorganic phosphate to dissolved metal humates

Abstract A cobalt-wire electrode was used to determine the concentration of free phosphate (P) in solutions containing a series of metal humates (MHA). The results were used in Scatchard plots to determine the stability constants of the dissolved MHA–P complexes formed. The constants were found to be high, with log K values in the range 4.8–6.0. Solutions containing MHA–P complexes were found to be relatively inert to the addition of phosphate-precipitating cations, indicating that MHA has a solubilizing effect on P and may enhance its mobility in the environment.
Modeling of distortions in optical characteristics of semiconductor lasers due to noise in MBE growth temperature measurement

Maintaining cladding-layer material composition uniformity is inherently difficult during high temperature MBE growth of GaAs/AlGaAs laser structures. These nonuniformities can lead to asymmetrical waveguiding structures with distorted optical output characteristics of the laser. Distortions in optical characteristics can greatly affect the alignment and the coupling efficiency between laser diodes and optical fiber or other electro-optical systems in integrated optoelectronic applications. A 2D dielectric waveguide simulator has been used to analyze the optical properties of GRINSCH GaAs/AlGaAs lasers with asymmetrical cladding structures. Through this analysis, we have demonstrated an optimal laser device structure which as the desired optical characteristics and is less sensitive to cladding composition asymmetries arising in typical growth conditions.© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Subsalt velocity estimation by target-oriented wave-equation migration velocity analysis: A 3D field-data example

ABSTRACTWe apply target-oriented wave-equation migration velocity analysis to a 3D field data set acquired from the Gulf of Mexico. Instead of using the original surface-recorded data set, we use a new data set synthesized specifically for velocity analysis to update subsalt velocities. The new data set is generated based on an initial unfocused target image and by a novel application of 3D generalized Born wavefield modeling, which correctly preserves velocity kinematics by modeling zero and nonzero subsurface-offset-domain images. The target-oriented inversion strategy drastically reduces the data size and the computation domain for 3D wave-equation migration velocity analysis, greatly improving its efficiency and flexibility. We apply differential semblance optimization (DSO) using the synthesized new data set to optimize subsalt velocities. The updated velocity model significantly improves the continuity of subsalt reflectors and yields flattened angle-domain common-image gathers.
A Progressive Format for Annual Interdisciplinary Education Featuring High-Risk Obstetric Simulation

Childbearing Poster Presentation Purpose for the Program Present a format that promotes the effective planning and facilitation of multiple simulation topics in obstetric complications and teamwork training in a structured prescheduled session. Proposed Change Our unit is planning structured annual review of high-risk, low-frequency clinical events in labor and delivery, including shoulder dystocia and postpartum hemorrhage using this progressive format to optimize staff and facilitator time and supply and space resources. Implementation, Outcomes, and Evaluation After the identification of the topics to be presented, simulation scenarios were developed that allowed progressive development of the patient's symptomatology. Staff were assigned and scheduled in small groups for these education days, which ensured that implementation was not dependent on unit workflows. This also ensured that all staff received an opportunity to participate. This results in efficient use of space, time, and resources because the stem of each scenario remains consistent and the participants all have first-hand knowledge of the preceding events. The scenarios built upon each other in situ, utilizing the same labor room and cesarean suite. Debriefing occurred after each scenario segment, which allowed focused reflection and discussion to occur before the next topic. TeamSTEPPS principles of effective teamwork and communication were stressed along with review of clinical responses. The participants of our sessions completed evaluations and rated the sessions very highly in terms of organization, being able to implement the ideas and activities, and being a beneficial use of time: overall 4.96/5.0. Implications for Nursing Practice This model represents an efficient use of resources in the planning and execution of simulation training for staff and health care providers who practice in a high-risk clinical area. Regular practice of clinical and medical teamwork behaviors can improve responses and positively affect outcomes of women and infants in the labor and delivery setting.
Weaning from prolonged mechanical ventilation using an antipsychotic agent in a patient with acute stress disorder

eaning from mechanicalventilation is reported bymanypatientstobeaphys-ically and emotionally un-comfortable experience. Those patientswith comorbid anxiety disorders may beparticularly vulnerable to difﬁculties withweaning. Prolonged mechanical ventilationis associated with numerous medical com-plicationsaswellasincreasedoccupationofintensive care beds, resource consumption,and costs; it is therefore crucial that psy-chiatricbarrierstoweaningbeaddressedinthe comprehensive care plan for difﬁcult-to-wean patients (1–3).The evidence for using psychotropicmedications in this population is extremelylimited (4, 5). Although psychiatric comor-bidities are considered to be risk factors forventilator dependency, no studies havebeen conducted and no expert recommen-dations are provided for pharmacologicanxiolysis during weaning (6). The use ofbenzodiazepines seems to be commonpractice, but it is not effective for all pa-tients. We present a case report of facili-tated ventilator weaning using quetiapine,a second-generation antipsychotic agent.
Conflict Strategies of Type-A Scoring Managers:

This study examined the association of 110 managers' scores on downward conflict management strategies and Type-A behavior scores. Analysis of self-reported scores indicated that (1) flexible types of strategies are negatively related to Type-A scores, (2) the aggression conflict strategy is the best predictor of Type-A scores, and (3) no support was found for the hypothesized relationship between the avoidance mode of conflict and Type-A scores. Implications of these findings and directions for research are briefly discussed.
Ensuring the safety of chemicals.

We now have the scientific tools to begin a new era of chemical management, an era in which exposure science will be more critical than ever.
Oxidation of Succinate by Heart Muscle

IT is widely held that the oxidation of succinate in animal tissues proceeds in the following manner:
Antiplatelet agents in cardiology: the choice of therapy

Abstract Background. The platelet-rich, intracoronary thrombus is central to the pathogenesis of acute myocardial infarctions, unstable angina, and the majority of complications of percutaneous coronary interventions. Until recently, aspirin was the only antiplatelet agent available to help prevent or treat these events. Over the past several years, there has been a substantial expansion in our antiplatelet armamentarium as well as in our understanding of the clinical importance of antiplatelet therapy in limiting the complications of intracoronary thrombosis. Because of this, it is likely that over the coming years, the use of antiplatelet therapies will continue to expand, and it may not be unusual for a surgeon to encounter a patient being treated with two or even three platelet inhibitors. Conclusions. This review will highlight the benefits and limitations of the currently available antiplatelet regimens: aspirin, thienopyridines (ticlopidine and clopidogrel), and the platelet glycoprotein IIb/IIIa inhibitors.
First report of tubenose goby (Proterorhinus semilunaris) in the eastern basin of Lake Erie

Abstract The tubenose goby ( Proterorhinus semilunaris ), native to the Ponto-Caspian region, was first discovered in the Laurentian Great Lakes in 1990 after it was introduced through ballast water discharge. Compared with Neogobius melanostomus , another exotic gobiid from the Ponto-Caspian, colonization of the Great Lakes by P . semilunaris has been slow, with reports of the species being largely confined to the Huron-Erie Corridor (HEC) and western portions of Lake Erie and Lake Superior. This is the first report of P . semilunaris in the Great Lakes east of the western basin of Lake Erie. Between 28 June and 27 July, 2012, 176 P . semilunaris were collected from shallow ( P . semilunaris collected at the site and the presence of individuals as small as 17 mm total length suggest an established population. However, the mechanism by which P . semilunaris was introduced to Presque Isle Bay is not clear.
Decoding the dipstick: Thickness of Siple Dome, West Antarctica, at the Last Glacial Maximum

Ice thickness in West Antarctica at the Last Glacial Maximum (LGM) is poorly known, yet is key information for understanding ice streams and interpreting ice cores. Although trim lines, moraine limits, and exposure-age dating provide geologic constraints on ice thickness near the Transantarctic Mountains and in Marie Byrd Land, lack of exposed bedrock hampers traditional geologic methods in a central, ;2 3 10 6 km 2 region. Here we infer ice-sheet thickness changes in the central Ross Sea Embayment by using a tran- sient ice-flow model to find combinations of accumulation-rate and ice-sheet thickness histories that match the depth-age relationship and the measured layer-thickness pattern in the Siple Dome ice core. After we reject unreasonable accumulation-rate histories, the remaining history pairs indicate thinning of 200-400 m since the LGM. Our estimate is lower than previous reconstructions that were constrained by geologic evidence from the Transantarctic Mountains and by marine data from the Ross Sea floor, which indicate that a grounded ice sheet extended to the continental shelf margin during the last glacial period. Low surface elevations in the central Ross Sea Embayment during the LGM do not preclude thicker ice along its boundaries. However, if this grounded ice sheet came over 1000 km from interior West Antarctica, as is usually assumed, then it had very low surface slope, requiring a very slippery bed. Alternatively, the grounded Ross Sea ice might have flowed from the Transantarctic Mountains and western Marie Byrd Land.
Laboratory Simulation of Industrial Crystallizer Cycling

The crystal size distribution (CSD) of the product in a large continuous industrial crystallizer usually fluctuates periodically (cycles) even under well-controlled operating conditions. This long-period cycling was simulated in the laboratory in a bench-scale crystallizer (5 dm 3 ) of ammonium sulfate, for the first time. A two-region crystallizer model consisting of a supersaturation production region (SPR) and a supersaturation consumption region (SCR) was proposed. Based on this model, a mechanism for the sustained CSD cycling was developed. This mechanism was used as a guideline in the construction of the laboratory crystallizer, in which a region of high and cycling local supersaturation was created, simulating the evaporative foam layer in the vacuum industrial crystallizers, as well as a bulk suspension with low supersaturation simulating the bulk suspension in the same crystallizers. The success of the crystallizer in achieving cyclic performance reinforces the proposed mechanism.
On the Possibility of Observing Nonexponential Decays in Autoionizing States

By taking into account analyticity properties of Fourier transforms, related to their asymptotic behavior, the origin of the deviation from the exponential decay “law” for autoionizing states is shown explicitly. Because of this result, we suggest that autoionizing states very near the ionization threshold may be candidates for observing nonexponential decay effects.
TRENDS IN THE UTILIZATION OF INPATIENT TRANSTHORACIC ECHOCARDIOGRAPHY: AN ANALYSIS OF 8 MILLION NATIONWIDE INPATIENT ADMISSIONS

Given the increasing debate concerning appropriate use of transthoracic echocardiography (TTE), we assessed the practice patterns for inpatient TTE in relation with cost of hospitalization and mortality outcomes. All projected national admissions in which TTE was designated the primary procedure
Performance evaluation of fiber optic probes for tissue lifetime fluorescence spectroscopy

The design of fiber-optic probes plays an important role in optical spectroscopic studies, including fluorescence spectroscopy of biological tissues. It can affect the light delivery and propagation into the tissue, the collection efficiency (total number of photons collected vs. total number of photons launched) and the origin of collected light. This in turn affects the signal to noise ratio (SNR) and the extend of tissue interrogation, thus influencing the diagnostic value of such techniques. Three specific fiber-optic probe designs were tested both experimentally and computationally via Monte Carlo simulations. In particular, the effects of probe architecture (single-fiber vs. two bifurcated multifiber probes), probe-to-target distance (PTD), and source-to-detector separation (SDS) were investigated on the collected diffuse reflectance of a Lambertian target and an agar-based tissue phantom. This study demonstrated that probe architecture, PTD, and SDS are closely intertwined and considerably affect the light collection efficiency, the extend of target illumination, and the origin of the collected reflected light. Our findings can be applied towards optimization of fiber-optic probe designs for quantitative fluorescence spectroscopy of diseased tissues.
Surface structure studies by x-ray photoelectron diffraction

Abstract Several recent developments and future prospects in the use of core-level X-ray photoelectron diffraction (XPD) for surface structure studies are considered. Experiments involving both standard X-ray sources and synchrotron radiation are discussed.
Primary excision and immediate wound closure

Surgical principles of early excision of devitalized tissue and prompt wound closure which govern the management of all traumatic injuries have been developed in the primary treatment of burns. Topical and systemic antibiotics which delay wound infection and control invasive sepsis provide an initial period of two to three weeks in which wound excision and closure is safe and effective. Full support of the central and peripheral circulation, respiratory function, nutrition, and musculoskeletal function are essential features of care until the burn wound is eliminated and closed.
A p-Multigrid spectral difference method for viscous compressible flow using 2D quadrilateral meshes

The work focuses on the development of a 2D quadrilateral element based Spectral Difference solver for viscous flow calculations, and the application of the p-multigrid method and implicit time-stepping to accelerate convergence. This paper extends the previous work by Liang et al (2009) on the p-multigrid method for 2D inviscid compressible flow, to viscous flows. The high-order spectral difference solver for unstructured quadrilateral meshes is based on the formulation of Sun et al for unstructured hexahedral elements. The p-multigrid method operates on a sequence of solution approximations of different polynomial orders ranging from one upto four. An efficient preconditioned Lower-Upper Symmetric Gauss-Seidel (LU-SGS) implicit scheme is also implemented. The spectral difference method is applied to a variety of inviscid and viscous compressible flow problems. The speed-up using the p-Multigrid and Implicit time-stepping techniques is also demonstrated.
Large reverse mismatch associated with pulmonary embolism.

Because alveolar hypoxia causes reflex vasoconstriction, areas of absent ventilation on lung scans usually are accompanied by matching perfusion defects. Perfusion of nonventilated lung, or reverse mismatch, has been described in a variety of conditions, including bronchial obstruction, atelectasis, and pneumonia (1-3), but not in pulmonary embolism. In this patient, a reverse mismatch involving almost the entire left lung was associated with extensive emboli to the opposite lung. It is likely that the increased vascular resistance produced by the emboli forced blood flow into the left lung, overcoming hypoxic vasoconstriction
African American women's preventative care usage: the role of social support and racial experiences and attitudes

Research suggests that African Americans are less likely to utilise preventative care services than Americans of European descent, and that these patterns may contribute to racial health disparities in the United States. Despite the persistence of inequalities in preventative care utilisation, culturally relevant factors influencing the use of these gateway health services have been understudied among marginalised groups. Using a stratified sample of 205 low-income African American women, this research examines the predictors of receiving a physical exam, with a particular emphasis on how differing levels of social support from friend and family networks and experiences of racial discrimination and cultural mistrust shape utilisation. The findings underscore the importance of traditional predictors of utilisation, including insurance status and having a usual physician. However, they also indicate that supportive ties to friendship networks are associated with higher predicted rates of having an annual physical exam, while social support from family and sentiments of cultural mistrust are associated with lower rates of utilisation. Broadly, the findings indicate that even as traditional predictors of help-seeking become less relevant, it will be critical to explore how variations in discrimination experiences and social relationships across marginalised groups drive patterns of preventative care utilisation.
Mechanism of Dephosphorylation of the SR Protein ASF/SF2 by Protein Phosphatase 1

Abstract SR proteins are essential splicing factors whose function is controlled by multi-site phosphorylation of a C-terminal domain rich in arginine–serine repeats (RS domain). The protein kinase SRPK1 has been shown to polyphosphorylate the N-terminal portion of the RS domain (RS1) of the SR protein ASF/SF2, a modification that promotes nuclear entry of this splicing factor and engagement in splicing function. Later, dephosphorylation is required for maturation of the spliceosome and other RNA processing steps. While phosphates are attached to RS1 in a sequential manner by SRPK1, little is known about how they are removed. To investigate factors that control dephosphorylation, we monitored region-specific mapping of phosphorylation sites in ASF/SF2 as a function of the protein phosphatase PP1. We showed that 10 phosphates added to the RS1 segment by SRPK1 are removed in a preferred N-to-C manner, directly opposing the C-to-N phosphorylation by SRPK1. Two N-terminal RNA recognition motifs in ASF/SF2 control access to the RS domain and guide the directional mechanism. Binding of RNA to the RNA recognition motifs protects against dephosphorylation, suggesting that engagement of the SR protein with exonic splicing enhancers can regulate phosphoryl content in the RS domain. In addition to regulation by N-terminal domains, phosphorylation of the C-terminal portion of the RS domain (RS2) by the nuclear protein kinase Clk/Sty inhibits RS1 dephosphorylation and disrupts the directional mechanism. The data indicate that both RNA–protein interactions and phosphorylation in flanking sequences induce conformations of ASF/SF2 that increase the lifetime of phosphates in the RS domain.
CAN TIDAL DISRUPTION OF ASTEROIDS MAKE CRATER CHAINS ON THE EARTH AND MOON

Abstract Crater chains, presumably formed by weak asteroids or comets stretched apart by planetary tides, have been tentatively identified on both the Earth and Moon. By modeling tidal disruption by the Earth and Moon of “rubble-pile” bodies, we find that the Earth disrupts enough objects over the last 3.8 billion years to account for one or two lunar crater chains, but that the reciprocal production rate of terrestrial crater chains is too low to make any in observable geological history.
Dynamics of the Euler Buckling Instability

We review recent systematic investigations of the dynamics of the classical Euler buckling of compressed solid membranes and thin sheets. We relate the membrane buckling dynamics to phase ordering phenomena. Evolving membranes develop wavelike patterns whose wavelength grows, via coarsening, as a power of time. We find that evolving membranes are similar to interfaces of thin films in molecular-beam epitaxy growth with slope selection: They are characterized by the presence of mounds whose typical size grows as a power of time. The morphologies of the evolving membranes are characterized by the presence of a network of growing ridges where the elastic energy is mostly concentrated. We used this fact to develop a scaling theory of the buckling dynamics that gives analytic estimates of the coarsening exponents. Our findings show that the membrane buckling dynamics is characterized by a distinct scaling behavior not found in other coarsening phenomena.
Facile hyphenation of gas chromatography and a microcantilever array sensor for enhanced selectivity.

The very simple coupling of a standard, packed-column gas chromatograph with a microcantilever array (MCA) is demonstrated for enhanced selectivity and potential analyte identification in the analysis of volatile organic compounds (VOCs). The cantilevers in MCAs are differentially coated on one side with responsive phases (RPs) and produce bending responses of the cantilevers due to analyte-induced surface stresses. Generally, individual components are difficult to elucidate when introduced to MCA systems as mixtures, although pattern recognition techniques are helpful in identifying single components, binary mixtures, or composite responses of distinct mixtures (e.g., fragrances). In the present work, simple test VOC mixtures composed of acetone, ethanol, and trichloroethylene (TCE) in pentane and methanol and acetonitrile in pentane are first separated using a standard gas chromatograph and then introduced into a MCA flow cell. Significant amounts of response diversity to the analytes in the mixtures ar...
Planning Some Two-Factor Comparative Surveys

Abstract In this paper it is assumed that, using a sample survey, two factors are to be studied, comparisons between the “levels” of the factors are of greatest interest, and there is “interaction” between the factors. Attention is concentrated on situations in which only two levels of each factor are to be compared, but extensions to more complex surveys are discussed. Assuming independent sampling, optimal sample size allocations are obtained. Where these allocations require recourse to programming algorithms, approximate solutions are given. If independent sampling is not feasible, a double sampling procedure is suggested. To indicate how sub-sampling from the first phase sample is to be carried out, a sampling rule (possessing optimal conditional precision properties) is derived. Then, a procedure to determine the optimal first phase sample size is given. Finally, it is demonstrated that this double sampling procedure can be applied to estimation of the (finite) population mean when double sampling wi...
Tunable plasma-based microwave waveguide time delay

Design of a plasma time delay unit (TDU) for microwave waveguides is proposed. The TDU comprises a base structure with two parallel grounded metal plates and an ultra-low loss dielectric strip waveguide. To tune the phase delay of the TDU, we surround the dielectric strip waveguide with plasma of tunable density and length. Based on the dispersion diagram at W-band, plasma-induced phase delay of up to 2π can be obtained by changing the plasma density. A systematic model-based parameter study of the physical quantities of this proposed structure has been carried out. The methodology is general and could be applied to other frequency regimes, to the extent that generation of the appropriate plasma is practical. The proposed design could be potentially used in an array of individually tunable elements for a high power beam-steering lens.
The use of phenobarbital and carbon tetrachloride to examine liver phospholipid exchange in intact rats.

Abstract 1. 1. 32Pi was injected into rats treated with phenobarbital or carbon tetrachloride. Liver mitochondria and microsomes were isolated 30 or 60 min after isotope administration. 2. 2. Phenobarbital treatment resulted in an expansion of the microsomal phospholipid pool. The specific activities of phosphatidyl choline and of phosphatidyl ethanolamine were lowered in both microsomes and mitochondria. Carbon tetrachloride treatment did not alter any phospholipid pool sizes but resulted in increased specific activities of microsomal and mitochondrial phosphatidyl ethanolamine. 3. 3. In each experiment the ratios of mitochondrial phospholipid specific activities to microsomal phospholipid specific activities were similar in treated and control animals. Apparently the newly synthesized [32P]phospholipids distribute themselves over mitochondria and microsomes according to their relative pool sizes. This interpretation is compatible with the existence of phospholipid exchange mechanisms in the cell.
Distributionally Robust Congestion Management With Dynamic Line Ratings

Dynamic line rating based on real time meteorological data has been shown to be useful in transmission line capacity management. Based on a binary rating forecast, we propose a distributionally robust congestion management model that selectively uses dynamic ratings on critical lines and keeps the risk of thermal overloading below a prescribed level. A case study illustrates that the proposed model can effectively alleviate transmission congestion with a low error rate.
Modeling the spectral variability of ground irradiance functions

We analyze a set of 7,258 0.4-2.2 micron ground spectral irradiance functions measured on different days over a wide range of conditions. We show that a low-dimensional linear model can be used to capture the variability in these measurements. Using this linear model, we compare the data with a previous empirical study. We also examine the agreement of the data with spectra generated by MODTRAN 4.0. Using a database of 224 materials, we consider the implications of the observed spectral variability for hyperspectral material discrimination using subspace projection techniques.
Postsurgical pneumoencephaly in a patient with Klippel-Feil syndrome.

A 49-year-old woman presented with occipital headaches, dizziness, photophobia and vomiting for 2 weeks’ status post posterior scalp mole removal by a general surgeon. The physical examination revealed occipital lesions with foul smelling purulent discharge mixed with clear fluid drainage, webbed neck with decreased range of motion, facial asymmetry and a low posterior hairline. A CT of head showed occipital skull defect providing a communicating pathway for scalp infection, an atlas fusion defect and an extensive pneumoencephaly. Further imaging showed low-lying cerebellar tonsils and fusion of the body of second and third cervical vertebrae. Klippel-Feil syndrome was diagnosed and the patient was successfully managed with duraplasty of occipital dura, placement of a lumbar drain and antibiotics. In patients with findings suggestive of Klippel-Feil syndrome and lesions proximal to the CNS, appropriate neuroimaging and possible neurosurgical consult should be considered prior to any surgical intervention.
Sterile water, and saline solution: Potential reservoirs of nosocomial infection

The serious consequences of contaminated intravenous (IV) therapy solutions have been documented in numerous reports.le3 In one hospital 16% of patients receiving parenteral hyperalimentation developed fungemia.4 In a previous report we documented an outbreak of CaMdidu infections among 21% of patients receiving hyperalimentation therapy.j The potential role of contaminated multidose vials in nosocomial dj sease transmission has received increasing attention.6-g Although incidents of nosocomial infection as a consequence of administering contaminated IV solutions or multidose drugs is well documented, there are few reports documenting contamination of screwcapped large-volume (250 to 1000 ml) bottles of sterile water and saline and other solutions used in patient care. Yet such solutions are associated with the expanding medical technology that has increased the intimate interface between a patient and the devices designed to prolong life and reduce suffering.‘o-12 These devices frequently bypass host defenses such as the intact integument or ciliated epithelium. Respiratory therapy, hemodialysis, peritoneal dialysis, and urinary and cardiac catheterization may involve use of sterile solutions that would represent a significant hazard to patient safety if such solutions are contaminated.
The effect of pre- and postmolt diets high in n-3 fatty acids and molt programs on skeletal integrity and insulin-like growth factor-I of White Leghorns

This study investigated changes in bone integrity and circulating concentrations of insulin-like growth factor-I (IGF-I) of hens subjected to 2 distinct molting regimens and fed pre- and postmolt diets high in n-3 or n-6 fatty acids. A dual-energy x-ray absorptiometer determined bone mineral density (BMD) of the tibia and humerus of 45 live hens from 62 to 76 wk of age. Densitometric scans were also conducted in excised tibia and humerus at 66, 71, and 76 wk of age. Concentrations of IGF-I were monitored using an homologous RIA at the same ages. The molting treatments consisted of 10 d of fasting + cracked corn for 7 d + pullet developer diet for 10 d or a nonfasting molt (wheat-middlings-based diet for 27 d). Five weeks prior to and after either molt treatment, birds were fed 1 of 2 diets containing dietary n-6/ n-3 fatty acids ratios of 0.6 or 8.0. At the end of the molt (71 wk of age), tibial BMD decreased 30% in fasted and 11% in nonfasted molt regimens, and the fatty acid content of the premolt diet had no effect on the decline in BMD. The BMD of the humerus also decreased during molt with the exception of hens subjected to a nonfasted molt and fed n-3 fatty acid diets in which their BMD values were similar to or greater (at 73 wk of age) than those of controls during the entire experimental period (treatment by bone by age, P < or = 0.0001). Induced molt affected circulating IGF-I concentrations (treatment by age interaction, P < or = 0.0001), and the response was the same regardless of molt regimen (fasting vs. nonfasting) or diet (n-3 vs. n-6 fatty acids). A decrease in IGF-I 54 h postmolt was noted; however, from 13 to 43 d postmolt, all molted birds had elevated IGF-I as compared with controls. In conclusion, a nonfasted molt as compared with fasted molt was less detrimental to bone mineralization; dietary n-6/n-3 fatty acid ratios in the pre- and postmolt diets had little effect on the decline of skeletal integrity during molt, and circulating IGF-I concentrations were affected by molt.
The Credibility Problem in Trade Liberalisation: Empirical Evidence from Kenya

This paper quantifies the welfare cost created by speculative accumulation of imports in Kenya during four trade reforms between 1976-92. These episodes suffered from a lack of credibility because they were perceived to be either time-inconsistent or incompatible with the exchange rate, fiscal or monetary policy. Kenyan data confirms that the private sector was able to anticipate the fate of the reforms and that it hedged against their reversal by accumulating foreign exchange licenses and bonded and actual imports. There are some indications of deferral of investment and increased liquidity during the abortive reforms. The speculative response seems to be self-fulfilling, as rapidly declining external reserves usually forced the government to abandon the reforms. The 1980 import liberalisation was the most costly attempt. Copyright 1996 by Oxford University Press.
Solar isotopic composition as determined using solar energetic particles

Solar energetic particles (SEPs) provide a sample of the Sun from which solar composition may be determined. Using high-resolution measurements from the Solar Isotope Spectrometer (SIS) onboard NASA’s Advanced Composition Explorer (ACE) spacecraft, we have studied the isotopic composition of SEPs at energies ≥20 MeV/nucleon in large SEP events. We present SEP isotope measurements of C, O, Ne, Mg, Si, S, Ar, Ca, Fe, and Ni made in 49 large events from late 1997 to the present. The isotopic composition is highly variable from one SEP event to another due to variations in seed particle composition or due to mass fractionation that occurs during the acceleration and/or transport of these particles. We show that various isotopic and elemental enhancements are correlated with each other, discuss the empirical corrections used to account for the compositional variability, and obtain estimated solar isotopic abundances. We compare the solar values and their uncertainties inferred from SEPs with solar wind and other solar system abundances and find generally good agreement.
Relationship of body mass index with asthma indicators in Head Start children

Objective To examine the relationship of body mass index (BMI) and asthma indicators on children with asthma in a Head Start (HS) program. Methods In this cross-sectional study (November 18, 2000, to December 12, 2003) of children aged 3 to 5 years with asthma, we compared the BMI data of HS asthmatic patients (n = 213) with the data of peer control subjects from a sample (n = 816) of the National Health and Nutrition Examination Survey aged 3 to 5 years and with children in prekindergarten in Arkansas public schools (n = 1,024). Parental reports of asthma symptoms, health care use, medication use, school days missed, and quality of life were used as indicators of asthma morbidity. Categorical analysis and χ 2 tests were performed to examine the relationship between BMI and asthma morbidity. Results The prevalence of overweight (≥95th percentile) was significantly higher in HS children with asthma compared with the National Health and Nutrition Examination Survey children ( P P = .05). Compared with HS asthmatic children with a BMI less than the 85 th percentile, HS asthmatic patients with a BMI of the 85th percentile or greater reported significantly more school days missed ( P = .02), lifetime hospitalizations ( P = .04), emergency department visits ( P = .02), and activity limitations ( P = .03) and fewer oral corticosteroid bursts ( P = .04). There was also a trend for more daytime symptoms ( P = .05) and lower quality of life ( P = .06). No differences were observed in rescue ( P = .28) or controller ( P = .47) medications, environmental tobacco smoke exposure ( P = .47), positive allergy test results ( P = .85), and nighttime symptoms ( P > .99). Conclusions Having an increased BMI was associated with more asthma morbidity in this group of HS asthmatic patients. Despite the lack of a clear explanation for the link between asthma and BMI, our data suggest that an increased BMI significantly affects the well-being of young asthmatic patients and should be further addressed.
Determination of mercury in zinc ore concentrate reference materials using flow injection and cold-vapor atomic absorption spectrometry

Abstract A flow-injection, cold-vapor atomic absorption spectrophotometric method was developed for the determination of trace amounts of mercury in a proposed zinc ore concentrate Standard Reference Material (SRM 113b). The samples were digested with nitric and hydrochloric acids in closed Teflon digestion vessels. The experimental details for sample preparation and the flow injection method are discussed. The effect of matrix and various acid concentrations on the extraction and subsequent analysis of mercury were also studied. The method has a detection limit of 0.08 μg Hg/g in the sample. A certified reference material (CZN-1) was analyzed and the results obtained agreed well with the certified value.
Neuroanatomic and Neurochemical Abnormalities in Non‐human Primate Infants Exposed to Weekly Doses of Ethanol during Gestation

Ethanol was orally administered once per week to 54 gravid pigtailed macaques (Macaca nemestrina) in doses of 0.0, 0.3, 0.6, 1.2, 1.8, 2.5 or 4.1 gm/kg from the 1st week in gestation or in doses of 2.5, 3.3 or 4.1 gm/kg from the 5th week. Mean maternal peak plasma ethanol concentrations (MPPEC's) ranged from 24 +/- 6 mg/dl at the 0.3 g/kg dose to 549 +/- 71 mg/dl at the 4.1 g/kg dose. Thirty-three live born infants were assessed for abnormalities of physical and behavioral development. Ocular pathology, neuropathologic and neurochemical assessements were done on 31 animals at 6 months postnatal age. Microphthalmia was noted in three of the 26 animals exposed to ethanol. Retinal ganglion cell loss was significantly associated with intra-uterine ethanol exposure. Microphthalmia and retinal ganglion cell loss was observed in both the delayed and full-gestational exposed animals. No structural anomalies were found in the brains via gross inspection or light microscopy. Chemical abnormalities in the striatal nuclei were identified. Striatal dopamine concentrations increased with increasing MPPEC exposure (0-249 mg/dl) among animals exposed weekly to ethanol throughout gestation. Striatal dopamine concentrations decreased with increasing MPPEC exposure (260-540 mg/dl) among animals whose weekly exposure to ethanol was delayed until the 5th week of gestation. The same pattern of association was also noted between MPPEC and ultrastructural alterations in the caudate nucleus. The extent of ultrastructural alterations increased with increasing MPPEC among the full-gestational exposed animals and decreased with increasing MPPEC among the delayed-dose animals.
On optimum relay deployment in a multi-hop linear network with cooperation

There has been a growing interest in designing relay deployment strategies for cooperative wireless networks. In this paper, we focus on multi-hop, cluster-based, linear networks. Several relay selection strategies are applied to achieve the cooperative diversity benefits. We derive the number of hops that minimizes the end-to-end outage probability. On the other hand, if the required overhead for cooperation is considered, increasing the number of relays in each cluster can degrade the performance. Using an information-theoretic approach, we also investigate the number of relays that maximizes the throughput. Simulation results are presented to verify the analysis.
Gene Therapy and Its Potential Role for Age-Related Macular Degeneration

Recent advances in molecular biology have given rise to gene therapy. Although gene therapy was originally thought of as a method for treating genetic disease clinical trials are now being designed for the treatment of proliferative and degenerative diseases as well. Here we discuss the fundamentals of gene therapy and how basic therapeutic strategies may pertain to age-related macular degeneration.