cssi/SciSciGPT-SciSciNet huggingface dataset:
Open thoracotomy procedural competency: validity study of teaching and assessment modalities.

Abstract Study objectives: To determine (1) reliability and validity estimates of three modalities used to assess open thoracotomy procedural competency and (2) the effect of computer practice on procedural performance as measured by the three assessment modalities. Methods: An experimental, sequential assessment design with volunteer examinees completing all three assessment modalities (paper, computer, pig model) was implemented at the animal support facilities of a university medical school with an affiliated emergency medicine residency program. Level of physician training (student, resident, faculty) and type of computer practice (thoracotomy, cricothyrotomy) were independent variables. Procedural competency scores were determined for each modality; scores were defined in terms of performance time and performance accuracy for three thoracotomy procedures (opening the chest, pericardiotomy, and aortic cross-clamping). Results: Thoracotomy performance on the pig reliably discriminated among examinees known to differ in level of training. However, computer simulation performance did not significantly differ among examinees with different levels of training. Computer simulation practice significantly improved later performance on the computer assessment ( P Conclusion: This study establishes the pig model as superior to the paper and computer models as the criterion standard for open thoracotomy assessment. Psychometric properties support the pig model as the most reliable and valid model yet described for assessing thoracotomy procedural competency. Computer simulation practice using visual images (complex anatomy) and the sequential ordering of procedural steps through paper modeling show promise for teaching and assessment of prerequisite skills required to develop psychomotor procedural competency. [Chapman DM, Rhee KJ, Marx JA, Honigman B, Panacek EA, Martinez D, Brofeldt BT, Cavanaugh SH: Open thoracotomy procedural competency: A validity study of teaching and assessment modalities. Ann Emerg Med December 1996;28:641-647.]
Hydraulic Characteristics of Organomodified Soils for Use in Sorptive Zone Applications

The sorption capabilities of subsoils for organic contaminants can be enhanced by modification of soil clays with cationic surfactants. The use of these organomodified soils to establish permeable sorptive zones has been suggested as a potential means for attenuating the migration of contaminant plumes. The hydraulic feasibility of sorptive zones was evaluated by measuring the hydraulic conductivities and porosities of both modified and unmodified soils at different effective stresses when permeated with water. Samples with 6, 12, 18, and 24% fines content were prepared and batch treated with hexadecyltrimethylammonium (HDTMA) to 80% of their cation-exchange capacities. Under the first load (24 kPa), all treated soils showed higher conductivities and similar or higher porosities than untreated ones. Higher loads decreased the difference in porosity between treated and untreated soils while increasing the difference between their conductivities. At the highest load (766 kPa), treated samples were 5 to 124 times more conductive than untreated ones depending on their clay contents. Differences in conductivities were explained in terms of the role of treated and untreated clays in controlling initial effective pore size and its change during consolidation. Creation of organomodified sorptive zones by batch soil processing is shown to be hydraulically feasible as evidenced by a marked increase in the conductivities of all treated samples compared with untreated ones. In addition. an increase in the sorptive capacity of the zone could potentially be achieved, without experiencing a loss in conductivity, by increasing the clay content during modification.
On the effect of spacing on the vortex-induced vibrations of two tandem cylinders

Abstract A spectral element method using Jacobi polynomial bases is employed to study the vortex-induced oscillations of two identical elastically mounted cylinders in tandem arrangement. Three different cylinder spacings, P / D = 2.5 , 3.5 and 5.0, are examined in order to identify the effect of spacing on the two-degree-of-freedom oscillations of the cylinders. Computations were conducted in two space dimensions (2-D)—an assumption that is expected to be valid for the Reynolds number, Re = 160 , considered. The single cylinder case is also examined at the same flow and structural parameters for reference and comparison. A widening of the range of the response region of the upstream cylinder is observed when the cylinder spacing is decreased. The synchronization curves of the upstream cylinder display a shift on the reduced velocity ( V R ) axis depending on the spacing. The maximum oscillation amplitude of the downstream cylinder increases when the cylinders are brought to a distance that the flow around the corresponding stationary system displays reattachment. There are three significant frequencies at the spectral responses: the shedding frequency of the stationary tandem system ( f o * * ); the shedding frequency of a single cylinder ( f o * ); and the natural frequency of the mass-spring system describing the dynamics of the cylinders ( f N ). The energy input of the flow on each cylinder is studied in terms of the line integral of the hydrodynamic force yielding the work, the phase angle between force and displacement at the prominent spectral frequency, and finally the lift in phase with velocity.
The post-antibiotic effect defined by bacterial morphology

Three strains of Escherichia coli were incubated with either ciprofloxacin or ampicillin. Filamentation of bacteria was observed after 1-2 h. After 5 h of contact with either drug the percentage of filaments exceeded 90%. The organisms were washed and incubated on drug free medium. Antibiotics when bound to an enzyme render that enzyme inactive; upon removal of the organisms from the antibiotic, the synthesis of enzymes resumes. The period of time encompassing the inactive enzymatic state of the organism at the time of removal from the drug to the time that enzymes restore complete function is our definition of the post-antibiotic effect (pae). Bacterial morphology reflects the variations in activity of these enzymes. The pae was determined by both the morphology of the organisms and the current growth kinetic method. The presence of 10% filaments and 90% bacilli was selected to indicate the endpoint of the pae by morphological criteria. The pae by morphology was 4 h for ciprofloxacin and 3 h for ampicillin. By the growth kinetics method it was 2 h for ciprofloxacin and zero for ampicillin.
A posteriori discontinuous Galerkin error estimation on tetrahedral meshes

Abstract In this manuscript we present a simple and efficient a posteriori error estimation procedure for a discontinuous finite element method applied to scalar first-order hyperbolic problems on structured and unstructured tetrahedral meshes. We present a local error analysis to derive a discontinuous Galerkin orthogonality condition for the leading term of the discretization error and find basis functions spanning the error. We describe an implicit error estimation procedure for the leading term of the discretization error by solving a local problem on each tetrahedron. Numerical computations show that the implicit a posteriori error estimation procedure yields accurate estimates for linear and nonlinear problems with smooth solutions. Furthermore, we show the performance of our error estimates on problems with discontinuous solutions.
Control of the charge-density-wave strength in MX solids using a structural template effect

Abstract A series of materials of stoichiometry [Pt(LL)2Cl2][Pt(LL)2]Y4, with LL = amine and Y = counterion, were synthesized and characterized employing X-ray diffraction and resonance Raman spectroscopy. These solids contain one-dimensional chains of alternating metal and halogen atoms that have undergone a Peierls distortion and charge disproportionation, producing alternating valence states on the metals along the chain axis: X-Pt(IV)-Cl…Pt(II)…Cl. It was discovered that the electronic and optical properties of these one-dimensional materials could be widely controlled through employing different combinations of LL and Y; templates composed of hydrogen bonded networks of LL and Y were used to control Cl-Pt(II)…Pt(IV)…Cl chain geometry. Relationships between the charge-density-wave strength (measured as the ratio of the long Pt(II)…Cl distance to the short Pt(IV)-Cl distance and band gap energy. Pt-Pt separation, and Pt-Cl stretching frequency were developed. This work has provided a wealth of information for many-body theoretical calculations modeling electron-electron and electron-phonon interactions in one-dimensional materials.
Prescription drug use in pregnancy.

Abstract Objective The purpose of this study was to provide information on the prevalence of the use of prescription drugs among pregnant women in the United States. Study design A retrospective study was conducted with the use of the automated databases of 8 health maintenance organizations that are involved in the Health Maintenance Research Network Center for Education and Research on Therapeutics. Women who delivered of an infant in a hospital from January 1, 1996, through December 31, 2000, were identified. Prescription drug use according to therapeutic class and the United States Food and Drug Administration risk classification system was evaluated, with the assumption of a gestational duration of 270 days, with three 90-day trimesters of pregnancy, and with a 90-day period before pregnancy. Nonprescription drug use was not assessed. Results During the period 1996 through 2000, 152,531 deliveries were identified that met the criteria for study. For 98,182 deliveries (64%), a drug other than a vitamin or mineral supplement was prescribed in the 270 days before delivery: 3595 women (2.4%) received a drug from category A; 76,292 women (50.0%) received a drug from category B; 57,604 women (37.8%) received a drug from category C; 7333 women (4.8%) received a drug from category D, and 6976 women (4.6%) received a drug from category X of the United States Food and Drug Administration risk classification system. Overall, 5157 women (3.4%) received a category D drug, and 1653 women (1.1%) received a category X drug after the initial prenatal care visit. Conclusion Our finding that almost one half of all pregnant women received prescription drugs from categories C, D, or X of the United States Food and Drug Administration risk classification system highlights the importance of the need to understand the effects of these medications on the developing fetus and on the pregnant woman.
Bacterial methanogenesis: Acetate as a methane precursor in pure culture

Pure cultures of methanogenic bacteria were shown to utilize acetate as a methanogenic substrate. In the presence of hydrogen, both Methanosarcina barkeri and Methanobacterium thermoautotrophicum rapidly converted acetate to methane. This reaction was shown to be dependent on the concentration of hydrogen and acetate. In the absence of hydrogen, acetate was not fermented by methane bacteria. Both the methyl and carboxyl position of acetate were reduced to methane. More 14C-methane was detected from methyl than carboxyl-labeled acetate. The utilization of acetate by cultures of M. thermoautotrophicum was enhanced by addition of CO2/HCO3 −. Methyl labeled acetate was shown to be incorporated into whole cells and converted to 14CO2 and 14CH4 in the presence of H2 and 25 mM CO2/HCO3 −. The importance of acetate utilization in microbial methanogenesis was discussed.
Optical phased array using high-contrast grating all-pass filters for fast beam steering

A novel 8x8 optical phased array based on high-contrast grating (HCG) all-pass filters (APFs) is experimentally demonstrated with high speed beam steering. Highly efficient phase tuning is achieved by micro-electro-mechanical actuation of the HCG to tune the cavity length of the APFs. Using APF phase-shifters allows a large phase shift with an actuation range of only tens of nanometers. The ultrathin HCG further ensures a high tuning speed (0.626 MHz). Both one-dimensional and two-dimensional HCGs are demonstrated as the actuation mirrors of the APF arrays with high beam steering performance.
Force reflecting teleoperation with adaptive impedance control

Experimentation and a survey of the literature clearly show that contact stability in a force reflecting teleoperation system requires high levels of damping on the master robot. However, excessive damping increases the energy required by an operator for commanding motion. The objective of this paper is to describe a new force reflecting teleoperation methodology that reduces operator energy requirements without sacrificing stability. We begin by describing a new approach to modeling and identifying the remote environment of the teleoperation system. We combine a conventional multi-input, multi-output recursive least squares (MIMO-RLS) system identification, identifying in real-time the remote environment impedance, with a discretized representation of the remote environment. This methodology generates a time-varying, position-dependent representation of the remote environment dynamics. Next, we adapt the target impedance of the master robot with respect to the dynamic model of the remote environment. The environment estimation and impedance adaptation are executed simultaneously and in real time. We demonstrate, through experimentation, that this approach significantly reduces the energy required by an operator to execute remote tasks while simultaneously providing sufficient damping to ensure contact stability.
Non-Discretionary Controls for Inter-Organization Networks

This paper describes a conceptual model for implementing usage controls in Inter-Organization Networks (IONs). After describing security requirements in networks that cross organization boundries, I suggest how traditional, non-discretionary controls can be adapted to support usage control in IONs.
Patterning Polyethylene Oligomers on Carbon Nanotubes Using Physical Vapor Deposition

Periodic patterning on one-dimensional (1D) carbon nanotubes (CNTs) is of great interest from both scientific and technological points of view. In this letter, we report using a facile physical vapor deposition method to achieve periodic polyethylene (PE) oligomer patterning on individual CNTs. Upon heating under vacuum, PE degraded into oligomers and crystallized into rod-shaped single crystals. These PE rods periodically decorate on CNTs with their long axes perpendicular to the CNT axes. The formation mechanism was attributed to "soft epitaxy" growth of PE oligomer crystals on CNTs. Both SWNTs and MWNTs were decorated successfully with PE rods. The intermediate state of this hybrid structure, MWNTs absorbed with a thin layer of PE, was captured successfully by depositing PE vapor on MWNTs detached from the solid substrate, and was observed using high-resolution transmission electron microscopy. Furthermore, this hybrid structure formation depends critically on CNT surface chemistry: alkane-modification of the MWNT surface prohibited the PE single-crystal growth on the CNTs. We anticipate that this work could open a gateway for creating complex CNT-based nanoarchitectures for nanodevice applications.
Fault tolerant routing in mobile ad hoc networks

The performance of ad hoc routing protocols will significantly degrade, if there are malfunctioned nodes in the network. Fault tolerant routing protocols address this problem by exploring the network redundancy through multipath routing. Designing an effective and efficient fault tolerant routing protocol is inherently hard, because the problem is NP-complete and the precise path information is unavailable. This paper solves this problem by presenting an end-to-end estimation-based fault tolerant routing algorithm E/sup 2/FT. E/sup 2/FT deploys two complementary processes: route estimation and route selection. Through end-to-end performance measurement, the route estimation process gives improving estimation results via iterations. Based on these estimation results, the route selection process decides a multipath route for packet delivery. The route selection is refined progressively with the increasingly accurate estimation result using "confirmation" and "dropping" procedures. Through theoretical analysis and simulation, we show E/sup 2/FT can achieve a high packet delivery rate with acceptable overhead.
Impact of nostalgia and past experience on recreational demand for wilderness

This primary objective of this study was to examine whether nostalgia plays any role in determining the demand for wilderness recreation using onsite survey data from Cheaha Wilderness in Alabama. In addition, an attempt was made to determine the impact of past wilderness experience and current residential setting on recreational demand. Since experience is a latent construct, a number of indicators, measuring the visitor's experience use history, were used to measure it. The results based on a truncated count data model show that trip cost and other visitor characteristics such as age, income, residential setting, and past wilderness experience were significant determinants for the visitation frequency. Moreover, the rural to urban migrants, who were expected to be more sensitive to nostalgic feelings, were making seven more trips than others.
Is prolonged stem cell mobilization detrimental for hematopoiesis

Multiple hematological side effects have been reported to result from treatment with psychoactive phenothiazines. These reported toxicities include leucopenia, granulocytopenia, thrombocytopenia, agranulocytosis, and bone marrow aplasia. The physiological mechanism causing these potentially life-threatening blood dyscrasias is unknown. Recently, we discovered that phenothiazines exhibit antagonistic properties towards the VLA-4 integrin, an adhesion molecule that is responsible for homing and retention of hematological stem/progenitor cells (HSPCs) in the bone marrow. After administration of thioridazine we detected rapid mobilization of HSPCs into the peripheral blood. We propose that in patients receiving phenothiazines over a prolonged time period, continuous mobilization of stem cells out of the stem cell niche, results in a disorder of hematopoiesis. Furthermore, we also postulate that such cytopenias are caused by a loss of the niche environment, which is known to be essential for stem cell maintenance.
Can silicon change photonics

The electronic chip industry embodies the height of technological sophistication and economics of scale. The industry mass produces complex circuitry, boasting over one billion components at such low cost that they appear in consumer products. Fabricating inexpensive photonic components by leveraging this mighty manufacturing infrastructure has been the impetus behind the development of silicon photonics. If it can be done economically and in an energy-efficient manner, empowering silicon with optical functionality will bring optical communications to the realm of computers where limitations of metallic interconnects are threatening the industry's future. Guided by such visions and propelled by pioneering research conducted in the 1980s and 1990s, silicon photonics has enjoyed spectacular progress in the last six years. The critical size of photonic devices has been scaled to the 300 nm regime making more efficient use of wafer real estate. Optical amplification and lasing, once considered forbidden in silicon, have recently been demonstrated. High-speed and efficient electrical-optical conversion is being performed by production-worthy devices. Silicon's nonlinear optical properties, enhanced by tight optical confinement in Si/SiO2 structures, are producing wavelength switching and generation, which are central functions in multiwavelength communications and signal processing. This article reviews these and other exciting progress being made in silicon photonics and identifies the challenges that remain on the path to commercialization. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
Research Gaps Related to Tobacco Product Marketing and Sales in the Family Smoking Prevention and Tobacco Control Act

This paper is part of a collection that identifies research priorities that will help guide the efforts of the U.S. Food and Drug Administration (FDA) as it regulates tobacco products. This paper examines the major provisions related to tobacco product advertising, marketing, sales, and distribution included in Public Law 111-31, the "Family Smoking Prevention and Tobacco Control Act". This paper covers 5 areas related to (a) marketing regulations (e.g., ban on color and imagery in ads, ban on nontobacco gifts with purchase); (b) granting FDA authority over the sale, distribution, accessibility, advertising, and promotion of tobacco and lifting state preemption over advertising; (c) remote tobacco sales (mail order and Internet); (d) prevention of illicit and cross-border trade; and (e) noncompliant export products. Each of the 5 sections of this paper provides a description and brief history of regulation, what is known about this regulatory strategy, and research opportunities.
An end to all things? — plants and their names

Great advances in our understanding of phylogenetic relationships have been made over the last decade and a half. Major clades in many groups, including flowering plants, now show substantial stability both in terms of content and relationships. This makes possible the development of a system in which only monophyletic ( = holophyletic) entities are named, entities that represent all and only the descendants of a common ancestor. However, some argue that use of Linnaean ranked names is inappropriate in such circumstances; this argument is bolstered by appeals to history and philosophy. Those who doubt the wisdom and / or very possibility of naming only monophyletic groups also argue that their position follows from history, or that ancestors cannot be incorporated into a Linnaean-type classification and that ancestors are an integral part of monophyletic groups. However, I argue that most of the apparently more cosmic issues brought up in this debate are based on a combination of a misunderstanding of the nature and purpose of language, fallacious reasoning and dubious—and largely irrelevant—interpretations of history. A flagged hierarchy helps memory and communication. Binomials in particular simply represent the noun–adjective combinations of ordinary language in a Latinised form, and are too valuable a communication device to be discarded because rank has been demonised. However, hierarchies can be misinterpreted and cannot be made complex enough to cope with the much more detailed phylogenies being produced. Thinking of naming systems as conventions may help clarify what we should be doing, if we are not to squander both the time and the reputation of systematics. Time is in short supply and our reputation not what it might be; solving the less cosmic issues may involve a self-discipline that also seems in short supply in the systematic community.
Single chip Nanotube sensors for chemical agent monitoring

In this paper, we present a single chip nanosensor composed of Single-Walled Carbon Nanotubes (SWNTs) integrated on complementary metal oxide semiconductor (CMOS) circuitry with custom designed on-chip amplifiers for chemical agent detection. The SWNTs were integrated on CMOS circuitry utilizing a low temperature and low voltage Dielectrophoretic (DEP) assembly process. Furthermore, we incorporated different sequences of single-stranded DNA (ss-DNA) on to SWNTs which improved their response to two toxic and explosive gases, namely Dimethyl methylphosphonate (DMMP) (an analog of nerve agent sarin [1]) by 9 times and Dinitrotoluene (DNT) (a byproduct of TNT [2]) by 12 times. In addition, the change in resistance (ΔR/R) of SWNT sensors increased from 12% to 24% when the concentration of DMMP vapor was increased from 8 ppm to 72 ppm; While ΔR/R increased from 7% to 23% when the concentration of DNT was increased from 9 ppm to 46 ppm. The SWNTs coupled with ss-DNA integrated onto CMOS circuitry shows great promise for monitoring low concentrations of toxic and explosive gases and potentially can be used to realize ultra-sensitive nanosensors.
Tapping and rubbing: exploring new dimensions of tactile feedback with voice coil motors

Tactile feedback allows devices to communicate with users when visual and auditory feedback are inappropriate. Unfortunately, current vibrotactile feedback is abstract and not related to the content of the message. This often clash-es with the nature of the message, for example, when sending a comforting message.We propose addressing this by extending the repertoire of haptic notifications. By moving an actuator perpendicular to the user's skin, our prototype device can tap the user. Moving the actuator parallel to the user's skin induces rub-bing. Unlike traditional vibrotactile feedback, tapping and rubbing convey a distinct emotional message, similar to those induced by human-human touch.To enable these techniques we built a device we call soundTouch. It translates audio wave files into lateral motion using a voice coil motor found in computer hard drives. SoundTouch can produce motion from below 1Hz to above 10kHz with high precision and fidelity.We present the results of two exploratory studies. We found that participants were able to distinguish a range of taps and rubs. Our findings also indicate that tapping and rubbing are perceived as being similar to touch interactions exchanged by humans.
Graph Partitioning with Natural Cuts

We present a novel approach to graph partitioning based on the notion of \emph{natural cuts}. Our algorithm, called PUNCH, has two phases. The first phase performs a series of minimum-cut computations to identify and contract dense regions of the graph. This reduces the graph size, but preserves its general structure. The second phase uses a combination of greedy and local search heuristics to assemble the final partition. The algorithm performs especially well on road networks, which have an abundance of natural cuts (such as bridges, mountain passes, and ferries). In a few minutes, it obtains the best known partitions for continental-sized networks, significantly improving on previous results.
Charm production in nonresonant e(+)e(-) annihilations at √s =10.55 GeV

This is the publisher's version also available electronically from http://journals.aps.org/prd/abstract/10.1103/PhysRevD.37.1719
Effects of diurnal and bidiurnal photoperiodic treatments on mitosis in Pharbitis

Abstract Photoperiodic effect on mitotic activity of buds from dwarf Pharbitis has been analyzed. No significant differences in mitotic activity were found in plants grown under long days or diurnal (24 h) light break photoperiodic treatments. Differences in both mitotic activity and flowering were seen in plants subjected to diurnal short days, bidiurnal (48 h) short days, or bidiurnal short days with light breaks. An elevation of mitotic activity occurs in plants grown in bidiurnal photoperiodic treatments compared to diurnal treatments. The differences in mitotic activity of buds, both vegetative and floral, seem to indicate that both phytochrome and light effect on an endogenous rhythm influence meristematic activity. Also, the extended dark period of a bidiurnal short day enhances both mitosis and flowering.
Bacterial Biofilms and Ocular Infections

Serious bacterial infections of the eye are often associated with abiotic prosthetic materials, such as contact lenses, intraocular lenses, and scleral buckles. In recent years, microbiologists have recognized substantial differences between bacteria growing in a sessile community attached to a surface and free-living or planktonic bacteria. These sessile surface-attached communities are known as biofilms, whose properties have important consequences for clinical medicine. As a population, bacteria in biofilms are more resistant to antimicrobial agents and the immune system, and they are more persistent than planktonic bacteria in hostile environments. These characteristics are likely the result of both biofilm-specific phenotypes and increased phenotypic diversity within biofilms as compared with planktonic communities of bacteria. Bacterial biofilm formation has been observed on human tissues, as well as on abiotic prosthetic devices. A better understanding of biofilm formation may lead to the development of novel antimicrobial agents as well as prosthetic devices that are resistant to bacterial colonization.
Parameters for optimization of device productivity at wafer level

The parameters that affect the productivity-wafer size, design system, levels of vertical integration, minimum feature dimension, chip size, and defect density-are examined. Expressions in terms of these parameters are given for the chip size that optimizes productivity at the wafer level. Figures of merit are shown for determination of the optimal design point. >
Effect of delayed reinforcement on skill acquisition during discrete-trial instruction: Implications for treatmen-integrity errors in academic settings

We used an adapted alternating treatments design to compare skill acquisition during discrete-trial instruction using immediate reinforcement, delayed reinforcement with immediate praise, and delayed reinforcement for 2 children with autism spectrum disorder. Participants acquired the skills taught with immediate reinforcement; however, delayed reinforcement decreased the efficiency and effectiveness of discrete-trial instruction. We discuss the importance of evaluating the influence of treatment-integrity errors on skill acquisition during discrete-trial instruction.
Next-generation transcatheter aortic valve replacement: evolution of a revolution.

Transcatheter aortic valve replacement (TAVR) is a revolutionary therapy that has had a profound impact not only on the care of patients with aortic stenosis but also on the entire cardiovascular profession. To date, more than 100,000 patients worldwide have received this life-saving therapy. With
General Chemistry Students' Goals for Chemistry Laboratory Coursework.

Little research exists on college students’ learning goals in chemistry, let alone specifically pertaining to laboratory coursework. Because students’ learning goals are linked to achievement and dependent on context, research on students’ goals in the laboratory context may lead to better understanding about the efficacy of lab curricula. This study characterized undergraduate students’ learning goals for general chemistry laboratory coursework by recording video of students completing laboratory experiments and interviewing the students about their experiences. The data was analyzed utilizing the framework of learning domains as described by Human Constructivism. Students were found to be primarily guided by affective goals, such as the desire to feel good by completing the requirements and getting done early. This stood in conflict with any psychomotor or cognitive goals they held concurrently. The data provide suggestions for reform of the general chemistry laboratory curriculum.
Characterization of Ce-Doped LaPO4 by X-Ray Absorption Spectroscopy

X-ray Absorption Spectroscopy (XAS) of the Rare Earth (RE) 3d levels yields sharp peaks near the edges as a result of strong, quasi-atomic 3d104fn→3d94fn+1 (M4,5) transitions that contain a wealth of spectroscopic features. XAS is a useful technique for the characterization of 4f-occupancy, 4f-hybridization, and valence in RE-containing materials. The XAS measurements of the single crystal RE-orthophosphates, as well as a range of Ce- doped (˜l–30%) LaPO4 hosts were performed at the 3d edge in the total electron yield mode at beamline 8–2 at the Stanford Synchrotron Radiation Laboratory (SSRL). The XAS spectra of the RE ions in the orthophosphate matrix generally resemble that of the corresponding RE metal and emphasize the major contribution of the trivalent state to the electronic transitions occurring at the 3d edge. There is no energy shift of the La and Ce absorption peaks with Ce doping and furthermore, no additional transitions are observed in either spectral region. However, accompanying the Ce doping there is a significant narrowing of the La absorption peak full width half maximum that contrasts to the Ce features that exhibit no contraction. The La and Ce spectra indicate that the Ce-doping of LaPO4 is purely substitutional.
A Theoretical Study of Biological Cell/Colloidal Particle Transport in Microchannels

A comprehensive understanding of the transport of biomedical cells in microchannels is of great importance for the development of fluidic devices for novel bio-diagnosis techniques such as cell labeling and sorting processes in cancer diagnosis research. In this paper mathematical models and computational simulations to describe the transport of cells and particles through micro- and nanochannels are developed. Additionally, we use the DLVO approach to estimate the particle-wall interaction energy when particles approach the wall. These calculations are compared against experimental and previous theoretical results and good agreement is found. Moreover, we complement our theoretical research by performing continuum simulations of biological cells surrounded by electrolytes and placed near walls. Surprisingly, the results show that wall effects on electrokinetic motion are weak.
Getting an eyeful of preseptal cellulitis.

Practitioners are often confronted with the mildly to moderately ill child who presents with an area of distinct redness and/or swelling of the skin around the eyelid. This is often accompanied by purulent conjunctival discharge, fever, purulent rhinorrhea, or concomitant acute otitis media. You must then decide whether this is preseptal cellulitis (peri-orbital cellulitis), orbital cellulitis, an allergic reaction, erythema secondary to trauma, contact dermatitis, or the result of eye rubbing. You must also perform a thorough physical examination, particularly evaluating the child’s level of toxicity, and the tympanic membranes, pharynx, lungs, and skin. Preseptal cellulitis (PC) is an infection of the skin surrounding the eyelid that is localized anterior to the orbital septum — a thin layer of fascia that provides a barrier to deeper invasion by infectious agents. The typical signs of PC are erythema, edema, and pain of the eyelid(s). It is usually unilateral, and may be associated with fever and acute otitis media (AOM). Specific manage ment options are addressed in the following cases. PC must be differentiated from the very serious infection, orbital cellulitis, which usually involves an osteomyelitis and invasion of the orbital bones. The cardinal features of orbital cellulitis are proptosis, chemosis, olphthalmoplegia, visual loss, and restricted ocular mobility. Immediate hospitalization, computed tomography (CT) scan of the orbit, and ophthalmologic referral is essential. Rarely, the swelling of the skin around the eyelid in PC may be so severe that a complete examination of the globe for signs of orbital cellulitis may be difficult or impossible, thus requiring CT imaging of the globe (similar to Figure 1).
Annual nutrient accumulation and translocation properties of Japanese chestnut in Liaoning Province

The aim of this study was to investigate the properties of accumulation and distribution of mineral elements in Japanese chestnut(Castanea crenata) and to establish a reasonable fertilization protocol. Field experiments were conducted to analyze the character of biomass composition, mineral element content and its accumulation in different parts of Japanese chestnut grafting trees which were 6-8 years old and the cultivars of Dafeng and Liaoli NO.10.The study results showed that the total dry biomass of Japanese chestnut aging from6 to 8 years old grafting tree was 10.64 kg/tree, 19.97 kg/tree and 35.03 kg/tree, respectively.With the same soil condition and same age trees, the total dry biomass of different chestnut cultivar was highly different. The translocation ratio of dry biomass was 31.36:24.53:13.56:11.54:7.81:5.80:3.49:1.92 among truck branches, roots, leaves, kernels, bur, new shoots, husk and male inflorescences. The average annual absorption of N, P2O5, K2O, Ca and Mg of 7 to 8 years old chestnut tree was 175.87 g/tree, 34.55 g/tree, 68.21 g/tree, 170.88 g/tree and 31.13g/tree respectively. In the early full bearing period, the total nutrient distributed into reproductive growth gradually increased year after year. In a chestnut tree, the total N or P2O5 amount in leaves was highest and the total K2O amount in kernels was highest. The absorption ratio of each element among the total elements absorption was N 36.57%, P2O5 7.19%, K2O 14.19 %, Ca 35.55% and Mg 6.48%, respectively. That is, NCaKMgP. According to our research results, to obtain 100 kg fresh fruit, chestnut tree must uptake N 3.06 kg, P2O5 1.50 kg,K2O 1.48 kg. The absorption rate was 2:1:1.This indicator could be refer to chestnut fertilizer in chestnut orchard in Liaoning province.
Simulation and role of discontinuous yield behaviors of material

Discontinuous yield of material as Jerky flow is explained. Then, the strain rate sensitivity (SRS) and instability criterion is given out. Some tests were carried out at constant stress rate, so PLC effect is manifested as a discontinuity in the stress-strain curves in form of strain bursts. Finally, the dynamic behaviors of specimens during instability of thermal origin were simulated with COLSYS software.
There is an association between human immunodeficiency virus infection and spondyloarthropathies.

The presence of inflammatory musculoskeletal manifestations during the course of human immunodeficiency virus (HIV) infection is well established. A wide spectrum of rheumatic disorders have been reported since the first reports of Reiter's syndrome with HIV infection. Other reported associations include forms of arthropathies, psoriatic arthritis, Sjogren's syndrome, polymyositis-dermatomyositis, vasculitis, and septic arthritis.
Prospective Randomized Trial of Warfarin and Intermittent Pneumatic Leg Compression as Prophylaxis for Postoperative Deep Venous Thrombosis in Major Urological Surgery

AbstractPostoperative deep venous thrombosis and pulmonary embolus remain a major source of morbidity and mortality for the urological surgery patient. We report the results of the first 100 patients in a prospective, randomized trial of low dose warfarin and intermittent pneumatic leg compression for deep venous thrombosis prophylaxis. All patients underwent preoperative and postoperative realtime ultrasound imaging and Doppler flow studies of the popliteal, femoral and iliac veins for the evaluation of deep venous thrombosis. Our results indicate that low dose warfarin is as effective as intermittent pneumatic leg compression for prophylaxis of deep venous thrombosis. Low dose warfarin can be used effectively without any significant bleeding complications. We recommend the use of low dose warfarin as an alternative to intermittent pneumatic leg compression for deep venous thrombosis prophylaxis of the urological patient undergoing a major urological operation.
Competition between strains ofDrosophila willistoni andD. pseudoobscura

El resultado de la competencia entreDrosophila willistoni yD. pseudoobscura depende de la constitucion genetica de las estirpes que compiten y de la temperatura. A 20 °C las dos especies coexisten, lo cual indica que el principio de exclusion competitiva no es universalmente valido.
Somali piracy prisoners and biopolitical penal aid in East Africa

Piracy off the coast of Somalia has elicited a growing body of interdisciplinary research. Much of this research focuses on identifying the root causes of piracy, analyzing onshore and offshore responses, or evaluating various rule-of-law approaches; no study has yet to examine how Somali piracy has impacted prisons. Drawing upon ethnographic research, this article explores how UNODC counter piracy funding is reshaping the carceral spaces of East Africa. I examine how the need to secure and develop Somali piracy prisoners in regional prisons has created a bodies-for-aid penal market in East Africa. Large aid packages are awarded to prisons that agree to accept suspected Somali pirates and ensure the support, maintenance, and enhancement of the lives of Somali piracy prisoners. I theorize a new form of penal aid—biopolitical penal aid—linking prison development funding to the containment of specific prisoner populations. Using the Montagne Posee Prison in the Seychelles as a case study, I explore how biopo...
Forest management and the H2B guest worker program in the southeastern United States : An assessment of contractors and their crews

Tree-planting jobs in the southeastern United States are almost exclusively held by workers from Mexico and Central America. Most of these workers are in the H2B guest worker program, a program designed to assist nonagricultural industries facing labor shortages. Based on a survey and interviews with forest contractors, we found that H2B workers have become the most common workers in forest management and are favored by contractors competing for large-acreage contracts as well as contractors specializing in government and industry contracts. We discuss the advantages of H2B workers, as well as problems in the program from the workers' perspective in wages and working conditions. The policy implications of a potential expansion of guest worker programs are also discussed.
Overcoming the minimum image constraint using the closest point search.

Abstract Finding the set of nearest images of a point in a simulation cell with periodic (torus) boundary conditions is of central importance for molecular dynamics algorithms. To compute all pairwise distances closer than a given cutoff in linear time requires region-based neighbor-listing algorithms. Available algorithms encounter increasing difficulties when the cutoff distance exceeds half the shortest cell length. This work provides details on two ways to directly and efficiently generate region–region interaction lists in n -dimensional space, free from the minimum image restriction. The solution is based on a refined version of existing algorithms solving the closest vector problem. A self-contained discussion of lattice reduction methods for efficient higher-dimensional searches is also provided. In the MD setting, these reduction criteria provide useful guidelines for lattice compaction.
Solid/Self-Lubrication Mechanisms of an Additively Manufactured Ni–Ti–C Metal Matrix Composite

A Ni–TiC–C metal matrix composite (MMC) has been processed using laser engineered net shaping. This additive manufacturing technique produced a Ni–3Ti–20C (at.%) composition with in situ formation of homogeneously distributed eutectic and primary TiC and graphite precipitates throughout the Ni matrix. The MMC exhibits a low steady-state friction coefficient of ~0.1 in dry sliding conditions. Novel insights into solid/self-lubrication mechanisms, with implications to other metal matrix-graphite particle composites, were revealed with focused ion beam serial sectioning inside worn surfaces. It was determined that lowering of the friction coefficient was a result of the formation of a low interfacial shear strength disordered carbon tribofilm that extruded to the surface through refined Ni grain boundaries. This was supported by finite element analysis that showed the evolution of subsurface stress states and precipitate motion during repeated sliding frictional contact.
Sharing information in time-division duplexing channels: A network coding approach

We study random linear network coding for timedivision duplexing channels for sharing information between nodes. We assume a packet erasure channel with nodes that cannot transmit and receive information simultaneously. Each node will act as both a sender of its own information and a receiver for the information of the other nodes. When a node acts as the sender, it transmits coded data packets back-to-back before stopping to wait for the receivers to acknowledge the number of degrees of freedom, if any, that are required to decode correctly the information. This acknowledgment comes in the header of the coded packets that are sent by the other nodes. We study the mean time to complete the sharing process between the nodes. We provide a simple algorithm to compute the number of coded packets to be sent back-to-back depending on the state of the system. We present numerical results for the case of two nodes sharing data and show that the mean completion time of our scheme is close to the performance of a full duplex network coding scheme and can outperform full duplex schemes with no coding.
Innovative detector layout for automated traffic turning volume counting

Summary Because of many advantages, loop detectors are the most common practice for obtaining data to control intersections. However, they have some drawbacks, including the fact that multiple detectors are usually required to monitor a location. The current practice in many cities is to install four consecutive loop detectors per lane, or two at the stop bar and one as an advanced detector. In some cities, there are also departure detectors. All these configurations have some practical problems and do not produce accurate counts especially in shared lanes. In this paper, a new placement configuration for departure detectors is proposed and named the mid-intersection detector (MID). In this configuration, departure detectors are moved back to the middle of the intersection in such a way that they can be activated by more than one movement at different times. In some cases, departure detectors lack equations for calculating turning movements, a problem solved by MIDs because each movement passes more detectors along its path (without increasing the number of loops), and therefore they can produce more accurate and reliable data for obtaining turning movement counts. Copyright © 2017 John Wiley & Sons, Ltd.