cssi/SciSciGPT-SciSciNet huggingface dataset:
A magnetic resonance template for normal cerebellar development in the human fetus.

OBJECTIVE: Although ultrasound is the primary imaging modality for prenatal anatomic evaluation, some central nervous system malformations may be better defined with high-resolution magnetic resonance imaging (MRI). MRI allows us to visualize the features of brain development that were previously only seen histologically by embryologists and anatomists. Although there are several reports of the postnatal development of the cerebellum as revealed on magnetic resonance (MR) images, systematic MR studies of cerebellar development during the fetal period are lacking. Our objective was to use high-resolution MRI to provide a template of cerebellar development during the late first and early second trimesters, a period when the diagnosis of congenital malformations is most medicoethically relevant. The MR findings were then correlated with histological data. METHODS: Twenty-six normal formalin-fixed fetal specimens with a gestational age of 9 to 24 weeks were examined with high-resolution MRI using a conventional clinical magnet and pulse sequences. The MR findings were correlated with the whole-mount histological specimens catalogued in a well-known fetal atlas. RESULTS: Resolution of the morphological features of cerebellar development in fetuses greater than 10 weeks gestational age was possible. Development of the rhombic lips, vermis, fourth ventricular roof, foramen of Magendie, and the cerebellar fissures was documented. Development of the cerebellum as revealed on MR images lagged behind the known stages of development by as much as 5 weeks. Features of cerebellar histogenesis were beyond the resolution of MRI. However, differences in signal intensity between gray and white matter of the developing cerebellum were detected and are postulated to represent differences in cellularity and water content of the constituent tissues. CONCLUSION: Direct correlation of MR images of fetuses during the late first and early second trimesters with anatomic atlases could result in a mistaken diagnosis of delayed or abnormal development of the posterior fossa contents because of a time lag in the detection of structures on MR images. An MR template of normal cerebellar development would be useful to avoid confusion of normal development with abnormal development and to identify the expected developmental features when provided the estimated gestational age of a fetus.
Foot-and-mouth disease virus: Immunogenicity and structure of fragments derived from capsid protein VP3 and of virus containing cleaved VP3

Peptide fragments were obtained from the immunogenic capsid protein VP3, ca. 24 kilodaltons (kd), of foot-and-mouth disease virus type A12 119ab by three procedures: (1) spontaneous proteolysis of in virion VP3 in tissue cultures to produce a 15 kd peptide, designated S fragment; (2) trypsin treatment of purified virus to produce a 16 kg peptide, designated T fragment; and (3) cyanogen bromide cleavage of purified VP3 to produce a 13 kd fragment. Following isolation and purification by gel electrophoresis, VP3 and each of the three fragments were immunogenic for livestock. Lyophilization appeared to impair the immunogenicity of VP3. In addition, viruses containing VP3 fragments produced either by the spontaneous- or trypsin-induced proteolysis were as immunogenic as virus with its VP3 intact. Amino acid sequencing of N-terminal regions revealed that the S fragment was homologous with the N-terminus of VP3, whereas the 13 kd fragment possessed a unique N-terminus. Thus, putative common immunogenic amino acid sequences would appear to reside within an overlap region of the 15 kd S and 13 kd fragments. Sequencing of cDNA prepared to viral genome RNA provided three kinds of information: it (1) placed the above overlap region in the second and third quarters of VP3; (2) demonstrated that the codons for the C-terminus of VP1 and N-terminus of VP3 are contiguous; and (3) supported earlier evidence that these same codons program a chain reversal where VP1 and VP3 are joined in the precursor polyprotein.
A Case Study of the Implementation and Maintenance of a Fee for Service Lighting System for a Rural Village in Sub Saharan Africa

Electricity is a critical need for the rural poor in developing countries. Often this need is met with disposable batteries. This results in high cost and problems with disposal. For example it was recently reported that an isolated rural village in West Africa with a population of 770 uses more than 21,000 disposable batteries per year and that purchase of these batteries accounts for 20–40% of household expense. As a result many organizations are seeking way to meet the need for village energy. This paper presents a case study of one such experience. In this study the efforts to meet the lighting needs of a cluster of eight rural villages with a population of approximately 8,000 people are discussed. A key aspect of this discussion is the challenge of creating a continuing and sustainable village lighting solution. In this case the technology chosen to implement a lighting system was a distributed micro-grid managed locally in each village. The success of this lighting grid has been in large part due to the continuing support of the local micro-grid system both financially and through continued engagement to maintain and upgrade the micro-grid systems.Copyright © 2012 by ASME
Activity Level, Activity Enjoyment, and Weather as Mediators of Physical Health Risks in Seasonal and Nonseasonal Depression

Research suggests that depression has negative consequences on physical health. One of the mechanisms driving this link may be the decrease in physical activity characteristic of individuals before and during a depressive episode. However, the factors that influence changes in physical activity across the seasons remain unclear. For instance, weather has been proposed to play an important role in the frequency of activities and enjoyment derived from them. In addition, research has not investigated how weather variables influence activity levels across the seasons in individuals with seasonal versus nonseasonal depression. The present study compared patterns of activity level and enjoyment in samples of women with seasonal and nonseasonal depression and controls. Women with Major Depressive Disorder (MDD) and MDD with a seasonal pattern (Seasonal Affective Disorder, SAD) reported similar patterns of activity; engaging in less frequent activity and deriving less enjoyment from activities than controls across the entire year, most notably during the winter months. Women with SAD also reported being significantly impacted by the weather such that their mood and energy levels increased with warmer temperatures an increased sunshine. Results suggest that women with seasonal depression may be at similar health risks as women with nonseasonal depression and activity patterns may have implications for behavioral activation treatments for depression.
On the Solid-Fluid Transition Zone in Welding Analysis

Equilibrium and energy equations have been developed in describing the solid-fluid transition zone during the melting and solidification of the binary alloys. Due to the existence of the transition region exhibiting both solid and fluid phases at the same material point from continuum point of view, mixture theory was utilized to analyze the region. Unlike the Stefan problem, the latent heat due to the phase change appears as a source term in the heat equation. The molten fluid is treated as a thermoviscous and incompressible fluid, whereas the solid is thermoviscoplastic described by the Bodner-Partom/Walker type of constitutive equations. Thermal mechanical behaviors of the solid and the fluid phases are determined separately because of insignificant mechanical interactions between them. Volume fractions of the phases are obtained according to the equilibrium phase diagram. The simulation process of the transition zone and the welding process was carried out by FEM. The molten fluid motion, the sizes, and the contours of the transition zone were presented.
Improved microwave photonic link performance through optical carrier suppression and balanced coherent heterodyne detection

We present a microwave photonic link architecture that enables high gain and dynamic range, low noise figure, and multi-octave bandwidth operation. Our method uses double sideband suppressed carrier modulation together with a balanced coherent heterodyne detection scheme. The modulation method increases link linearity by producing carriersuppressed amplitude modulation based on the optical field rather than intensity. The combination of carrier suppression, optical amplification, phase-locked local oscillator insertion, and balanced detection provide high signal-efficient gain, reduced intermodulation distortion, wide-band operation, frequency agile spectrum access, and low link noise.
TNP-470 reduces collagen and macrophage accumulation in expanded polytetrafluoroethylene tube implants.

Background. TNP-470 is a potent angiogenic inhibitor that has been demonstrated to decrease the rate of cutaneous wound healing. This study investigated the effect that TNP-470 has upon collagen growth and macrophage infiltration into expanded polytetrafluoroethylene (e-PTFE) tube implants. Methods. e-PTFE tubes (1.0 cm in length) were implanted into the dorsum of male Swiss–Webster mice (8–10 weeks old). TNP-470 was administered subcutaneously in doses of 0.5, 1.0, or 5.0 mg/kg for determination of hydroxyproline accumulation on day 18 after implantation. Additionally, TNP-470 was administered at 5.0 mg/kg for determination of macrophage infiltration on days 4, 8, 13, and 18 after implantation. Results. Administration of TNP-470 at doses of 1.0 and 5.0 mg/kg on days 0, 2, and 4 significantly (P < 0.05) decreased hydroxyproline accumulation in e-PTFE implants on day 18 after implantation. Administration of 0.5 mg/kg of TNP-470 yielded no significant difference vs the vehicle control (P < 0.81). Additionally, administration of TNP-470 at 5.0 mg/kg on days 0, 2, and 4 significantly (P < 0.05) decreased macrophage infiltration into e-PTFE implants on day 4 after implantation. There was also a significantly (P < 0.05) increased percentage of macrophages in the e-PTFE implants on day 13 after wounding. No significant differences were observed between the experimental and control groups on days 8 and 18. Conclusions. Administration of TNP-470 significantly decreases hydroxyproline accumulation in e-PTFE implants. These data suggest that while TNP-470 is administered, macrophage infiltration is impaired; however, upon discontinuing administration, macrophage infiltration increases. Possible mechanisms to account for these findings are discussed.
A new eletronic spectrum of the SiH3 radical observed using multiphoton ionization spectroscopy

Abstract The silyl radical, SiH 3 , was observed between 365 and 410 nm using resonance-enhanced multiphoton ionization spectroscopy. The spectrum arises from two-photon resonance states which lie between 49229 and 54014 cm −1 . A vibrational progression interval of ≈ 800 cm −1 was assigned to the resonant intermediate state symmetric deformation mode, ν 2 .
Charging Station of a Planar Miniature Thermal Ground Plane

Thermal ground planes (TGPs) are flat thin (less than 1 mm thick) heat pipes that can be used as a thermal spreader in a variety of microelectronic cooling applications. Like conventional heat pipes, TGP’s utilize two-phase cooling. Major advantages, include the ability to integrate directly with the microelectronic substrate for a wide range of applications; and the ability to operate in an adverse gravity environment of up to 20g. Other advantages include a very high thermal conductivity, reliability, no moving parts, electrodes, or need for external power. A key factor in the design of the TGP is evacuation prior to filling and introduction of the proper amount of working fluid (water) into the device. The major challenge of this work is to fill heat pipes with a total liquid volume of less than 1 ml, without being able to see into the device. The current filling station is an improvement over the current state of the art as it allows for accurate filling of micro liter sized volumes. Tests were performed to validate performance of the system and to verify that little to no non-condensable gasses were introduced to the system. Careful calibration of the amount of liquid introduced is essential. Therefore, calibration of the burettes utilized for a liquid fill range of 0.1 ml to 100ml was important. The magnitude of the pressure inside the TGP envelope is also an important factor. Calibration curves for the burettes and error characterization curves for a range of liquid charging volumes will be presented and discussed.Copyright © 2011 by ASME
A novel load metric with enhanced ability of distinguishing different load status

This paper has proposed a new metric for characterizing the load of a uniprocessor computer. This metric is defined as a ratio of the average waiting time experienced by computing tasks to the average idle time of the processor. This definition is based on two important observations. As the load becomes heavier, the average idle time of a processor becomes shorter, and the average waiting time experienced by computing tasks becomes longer. The new load metric aims to have an enhanced ability in distinguishing different load status. The valid comparison of different load status using the new load metric is subject to the satisfaction of certain conditions: a majorization has to be satisfied between two processes of the measures (idle time or waiting time). The ability of the new load metric on distinguishing different load status has been validated through numerical simulations. The results showed that the new load metric can facilitate balancing the load among multiple servers better than the conventional load metric of average utilization, when they are used as the task assignment criteria.
Characterization of fibroblasts and proteins on thin films

The ability of biomaterial surfaces to regulate cell behavior requires control over surface chemistry and microstructure. One of the greatest challenges with silicon biomedical microdevices is to improve biocompatibility, which may be achieved by modifying the exposed silicon surface with thin or adsorbed films. In this study, films of silicon nitride, doped polysilicon, undoped polysilicon, as well as RGD peptide adsorbed surfaces were incubated with fibroblasts for a period of four days. Results demonstrate that RGD adsorbed surfaces encourage the greatest cell proliferation, followed by undoped polysilicon and unmodified (control) surfaces. Protein adsorption studies using fibrinogen and albumin, two proteins implicated in cellular adhesion and surface activity, reveal greatest protein adsorption on low stress silicon nitride surfaces, followed by undoped polysilicon and unmodified surfaces. This finding may compliment the differential cellular binding found on modified and unmodified silicon surfaces. The thickness of adsorbed albumin and fibrinogen was measured by ellipsometry and compared to contact angle measurements of non-adsorbed surfaces. Moreover, silicon surfaces coupled with a synthetic RGD peptide, as characterized with XPS and atomic force microscopy, display enhanced cell proliferation and bioactivity. Understanding the biological response to thin films will allow us to design more appropriate interfaces for implantable diagnostic and therapeutic silicon-based microdevices.
Voices of Change: Short Stories by Saudi Arabian Women Writers: Edited and translated by Abubaker Bagader, Ava M. Heinrichsdorf, Deborah S. Akers. Additional Translations by Abdul‐Aziz Al‐Sebail

Book reviewed in this article: Within the Circle: Parents and Children in an Arab Village: Andrea B. Rugh
Overview of series connected flexible AC transmission systems (FACTS)

Static series compensation devices provide additional flexibility in the operation of transmission lines. Many articles have been published in literature which demonstrate how static series connected FACTS devices can solve numerous power system problems. However, they are not widely utilized in the power industry. The complexity and cost of these devices make it hard to justify their installation. The paper presents the various applications of series connected FACTS devices and the controllers used in literature. It also presents a comparison between fixed and static series compensation device. The paper also explores the economic challenges of installing series connected FACTS devices on the electric power system and some possible economic solutions. A cost effective solution to implement static phase shifting at the neutral of power transformers is presented.
Phytophthora porri from stored carrots in Alberta.

to that shown by the other named fungal species isolated from rotted alfalfa crowns. In two such tests (conducted in the greenhouse) the roots of 3and 6month-old greenhouse-grown plants (cv. Ranger) were cut crosswise 6 cm below the crown and the cut surface was immersed for two months in soil-cornmeal inocula of 4-8 isolates of the different fungal species layered within potted sand. In the third test, toothpicks colonized by the same isolates were inserted into the side of the main root 1 cm below the crown of 1-year-old field-grown plants (cv. Vernal). The plants were held 3 months in moist sand in the greenhouse. The fungus thus would appear to be a saprophyte or a weak parasite. I thank Dr. Wayne S. Gardner for photographic help.
Rate equation analysis of longitudinal spatial hole burning in high-power semiconductor lasers

For high-power semiconductor lasers, asymmetric reflectivities of facets are employed in order to improve slope efficiency. Cavity lengths of these laser diodes have been increased to better distribute heat in order to improve output power. However, these two methods result in an inhomogeneous longitudinal profile of photon density, which leads to a nonuniform gain profile and is typically referred to as longitudinal spatial hole burning (LSHB). In this work, we developed a model to self-consistently calculate the longitudinal photon density distribution, carrier density distribution, and gain distribution in a high-power semiconductor laser. The calculation is based on modified rate equations, and a finite difference method is used to solve the differential equations. Newton’s method is employed to obtain final results with residual error below 10 -6 . The impact of LSHB was analyzed with different parameters, and we demonstrate that LSHB is expected to limit the maximum achievable output power of semiconductor lasers having cavity lengths in excess of several mm. The results are expected to be useful in the optimization of high-power semiconductor laser designs.
Dopaminergic Modulation of Striatal Sensory Responses

The results of the present work showed that dopamine clearly had an influence on sensory processing in the striatum. In addition, this study also demonstrated that the acute effect of the neuroleptic, haloperidol, was on presynaptic receptors to increase the release of dopamine. The clinical implications of this finding was briefly discussed.
Host Teachers' Evaluations of Nonnative‐English‐Speaking Teacher Trainees—A Perspective from the Classroom

This article discusses the results of a survey conducted to explore how students and host teachers perceive the strengths of nonnative-English-speaking (NNES) teacher trainees based on their classroom practice. Responding to a questionnaire evaluating the NNES ESL teacher trainees in their classrooms, host teachers named the following as their strengths: teaching ability, professional skills, the grammaticality and idiomaticity of their English, and the multilingual and multicultural resources that they bring. Host teachers noted that NNES teacher trainees understood their students' learning problems and concerns, often served as role models for ESL students, and enriched the classroom experience. A small percentage of host teachers were dissatisfied with their trainee's performance because they felt the trainee had inadequate command of English. The results of the survey suggest that NNES teacher trainees are generally perceived as capable of delivering efficient instruction and treated as a welcome addition to the ESL practicum classroom.
Rationale and Procedures for Using the Tissue-Residue Approach for Toxicity Assessment and Determination of Tissue, Water, and Sediment Quality Guidelines for Aquatic Organisms

ABSTRACT This article describes a set of procedures for developing tissue, water, and sediment quality guidelines for the protection of aquatic life by using the tissue-residue approach (TRA) for toxicity assessment. The TRA, which includes aspects of the Critical Body Residue (CBR) approach, associates tissue concentrations of chemicals with adverse biological effects in a dose-response fashion that can be used to determine CBRs. These CBRs can then be used to develop tissue quality guidelines (TQGs), which may be translated into water or sediment guidelines with bioaccumulation factors. Not all toxicants are amenable to this type of analysis; however, some appear to exhibit relatively consistent results that can likely be applied in a regulatory framework. By examining tissue residues, variations in toxicokinetics (temporal aspects of accumulation, biotransformation, and internal distribution) are greatly reduced allowing a greater focus on toxicodynamics (action and potency) of the toxicants. The stron...
The health status of youth in juvenile detention facilities

Youth exiting detention facilities have particularly high rates of co-occurring health-risk behaviors, while lacking access to the health care system. Not surprisingly, these youth suffer a disproportionate share of adolescent morbidity and mortality. Their time of incarceration often represents their only significant contact with a health care provider outside of an emergency setting. As such, it is critical that health care providers utilize the opportunity to educate and connect these youth with community resources to facilitate their access to health care upon their reemergence into the community. We review the factors affecting the health of youth in detention, and the health problems that are among the greatest sources of morbidity and mortality in this adolescent population.
Liquid-filled camera for the measurement of high-contrast images

Light-measurement instrumentation based upon high-quality charge-coupled-devices (CCD) is currently in use for measuring the characteristics of electronic displays. When such array detectors are used to measure scenes or images having high contrasts or wide color variations, they can suffer from the effects of veiling glare or lens flare and thereby inaccurately measure the darker luminances because of a mixing of the scene luminances or colors. A liquid-filled simulated-eye design (SED) camera was constructed to improve the ability to measure such images by reducing the internal scattering that contributes to the veiling glare. This paper discusses the investigation of the use of various liquids, in particular the effects of scattering within the liquids.
A large heteropolytungstotetracerate(III) based on a new divacant lacunary derivative of the Wells–Dawson tungstophosphate anion

Abstract The heteropolyanion [Ce4(OH)2(H2O)9(P2W16O59)2]14– (1) has been isolated as a potassium salt, in ∼40 % yield, from a neutral solution formed by reaction of a suspension of K12H2P2W12O48·24 H2O in 1 M LiCl with Na2WO4 and Ce(NO3)3. Single crystal X-ray analysis of K12H2[Ce4(OH2)9(OH)2(P2W16O59)2]·48 H2O (monoclinic, space group C2, a=28.198 0(2) A, b=12.205 80(10) A, c=23.238 00(10) A, α=114.879 0(10)°; 17 164 independent reflections; R1=0.057 6) reveals an anion of C2v virtual symmetry in which four Ce3+ cations are sandwiched between two novel divacant lacunary derivatives of the Wells–Dawson anion, α-[P2W18O62]6–. The lacunary anions (of Cs symmetry) have adjacent metal atom vacancies on both sides of the equator of the Wells–Dawson structure. The four cerium(III) centers (two 9- and two 10-coordinate) are linked by two μ3-OH(Ce3), one μ2-H2O(Ce2) and four μ3-O(W,Ce2). The heteropolyanion is stable in aqueous solution and yields well resolved 31P (δ=+4.0 ppm) and 183W NMR spectra (8 lines of equal intensity, δ=+296 to −188 ppm) that are consistent with the solid state structure. © 2000 Academie des sciences / Editions scientifiques et medicales Elsevier SAS polyoxometalates / lanthanides / tungsten / NMR / crystallography
Spectroscopy of amorphous and crystalline titania-silica materials

Both amorphous and crystalline silica doped with Ti(IV) ions have properties ranging from selective chemical catalysis to useful thermal and optical characteristics. These properties are related to the distribution of titanium sites in the silica lattice. It has been proposed that the Ti(IV) isomorphically substitutes for Si in the lattice in an essentially tetrahedral geometry. In this study we compare the electronic and vibrational spectroscopic characteristics of a series of both dense and porous amorphous titania−silica materials with crystalline titania−silicalite (TS-1). All of the spectroscopic properties are referenced to titania−cristobalite, which contains titanium in a rigorous crystallographic environment that deviates only slightly from tetrahedral. It is found that the amorphous materials have spectroscopic properties that are extremely close to Ti-cristobalite while TS-1 deviates significantly.
Characteristics of dust particles detected near Saturn's ring plane with the Cassini Radio and Plasma Wave instrument

Abstract During the inbound and outbound passes of the Cassini spacecraft through Saturn's ring plane on July 1, 2004, the Radio and Plasma Wave Science (RPWS) instrument detected many small particles striking the spacecraft. When a small particle strikes the spacecraft at a high velocity, it is instantly vaporized and produces a small cloud of plasma that expands radially outward from the impact site. As the plasma cloud expands away from the spacecraft it produces a voltage pulse on the RPWS electric field antennas, the amplitude of which is proportional to the mass of the impacting particle. Two types of measurements are made: waveform measurements from the x-axis dipole antenna, and spectrum measurements from the w-axis monopole antenna. The waveform measurements from the dipole antenna provide a determination of the impact rate and the relative mass distribution, and the spectrum measurements from the monopole antenna provide a determination of the root-mean-square particle mass. The impact rate at both ring plane crossings provides a good fit to the sum of two Gaussians, with an average impact rate of about 1200 per second (the exact value depends on the voltage threshold used), and a north–south thickness of about 300 km. The mass distribution depends on the distance from the ring plane, varying from about m−2 near the ring plane at z = 0 ± 100 km , where z is the north–south distance from the ring plane, to as steep as m−4 well away from the ring plane at z = 500 ± 100 km . The mechanisms involved in the impact detection are discussed and a formula relating the root-mean-square particle mass to the root-mean-square voltage on the w-axis monopole is derived. Using this formula, the root-mean-square mass is estimated to be 7.7×10−11 g, which for water ice particles with a density of 0.92 g cm−3 gives a root-mean-square radius of about 2.6 μm.
Myocardin expression during avian embryonic heart development requires the endoderm but is independent of BMP signaling

Myocardin, a serum response factor cofactor, plays an important role in regulating heart and smooth muscle development. To investigate myocardin function during early stages of heart development, we isolated the chicken orthologue of myocardin and characterized its expression between Hamburger and Hamilton stages 3 and 15. At stage 4, myocardin transcripts are detected in the lateral and extraembryonic mesoderm, become progressively localized to the precardiac mesoderm and the differentiated myocardium and are also seen in smooth muscle cells of the developing vascular plexus. Surprisingly, myocardin expression within the developing chicken embryo precedes that of the homeodomain transcription factor Nkx2.5. Embryonic dissection studies demonstrate that signals from the endoderm are required for myocardin expression within the precardiac mesoderm. However, unlike Nkx2.5, myocardin expression is not regulated by bone morphogenetic protein (BMP) signaling. These results suggest that initial expression of myocardin in the precardiac mesoderm is regulated by a signaling pathway that is parallel to, and independent of, Nkx2.5 expression.
The k-Version Finite Element Method for Singular Boundary-Value Problems with Application to Linear Fracture Mechanics

This paper presents an application of the k-version finite element method to the numerical simulation of boundary value problems that contain singularity of the solution derivatives at certain point(s) in the domain. The theoretical solutions of such problems contain extremely isolated high solution gradients that approach infinity at the singular point(s); i.e., the solutions are not analytic at the singular point(s) but are analytic everywhere else. It is demonstrated that when numerical solutions of such problems are simulated in progressively increasing order scalar product spaces k , p ( e ), they approach the same characteristics in terms of differentiability as the theoretical solution as k is increased and in the limit k → ∞ , the numerical solutions have exactly the same global differentiability characteristics as the theoretical solutions. A two-dimensional linear elastic fracture mechanics problem is used as a model problem to illustrate the salient features of the k-version finite element method.
An unusual new “sea fan” from the northeastern Pacific Ocean (Cnidaria: Octocorallia: Gorgoniidae)

Abstract An unusual new species of gorgonian octocoral, Leptogorgia filicrispa, is described from specimens collected off the coasts of Sonora, Gulf of California (Mexico), Baja California (Mexico), and southern California (U.S.A.). Unusual features include: the long, extremely thin, wiry and brittle branches of the colony; the highly tangled condition of those numerous branches; and general lack of an attachment holdfast. Multiple color forms of the branches, in the same colony, also occur.
Nonnested linear model selection revisited

In testing nonnested or separate hypotheses, statistical practitioners typically use the j-test, due to Davidson and MacKinnon (Estimation and Inference in Econometrics, Oxford University Press, New York, 1981), which is based on an artificial nesting approach. Results of a previous paper (Watnik and Johnson, The Behavior of Nonnested Linear Model Selection Tests Under the Alternative Hypothesis, UC Davis Technical Report, 2000) imply that the j-test is often asymptotically most efficient among the testing procedures in the literature. The j-test, however, is prone to making Type I errors (cf. Godfrey and Pesaran, J. Econometric. 1983, 84, 59–74). We formulate a different parameterization of the models, which facilitates comparisons of the various tests, and which provides a common framework for deriving asymptotic distribution theory. We also consider a finite-sample corrected, j-test statistic, similar to the one considered by Royston and Thompson (Biometrics, 1995, 51, 114–27). This statistic greatly i...
Perceived reality in television effects research

This essay illuminates critical findings, limitations, and assumptions underlying the literature on perceived reality. Following a process of construct validation, the paper is structured to develop a conceptual definition and to hypothesize how the elements of that definition should be logically and empirically related to other relevant concepts and their measures. Perceived reality should be regarded as a multidimensional construct composed of magic window, utility, and identity elements. The existing research is critically evaluated to determine the extent to which each definitional element is supported.
Residents' preferences and preparation for caring for underserved populations

Access to care by low-income persons and residents of rural and poor innercity areas is a persistent problem, yet physicians tend to be maldistributed relative to need. The objectives were to describe prefernces of resident physicians to locate in underserved areas and to assess their preparedness to provide service to low-income populations. A national survey was made of residents completing their training in eight specialties at 162 USacademic health center hospitals in 1998, with 2,626 residents responding. (Of 4,832 sampled, 813 had invalid addresses or were no longer in the residency program. Among the valid sample of 4,019, the response rate was 65%). The percentage of residents ranking public hospitals, rural areas, and poor inner-city areas as desirable employment locations and the percentage feeling prepared to provide specified services associated with indigent populations were ascertained. Logistic regressions were used to calculate adjusted percentages, controlling for sex, race/ethnicity, international medical graduate (IMG) status, plans to subspecialize, ownership of hospital, specialty, and exposure to underserved patients during residency. Only one third of residents rated public hospitals as desirable settings, although there were large variations by specialty. Desirability was not associated with having trained in a public hospital or having greater exposure to underserved populations. Only about one quarter of respondents ranked rural (26%) or poor inner-city (25%) areas as desirable. Men (29%. P<.01) and noncitizen IMGs (43%, P<.01) were more likely than others to prefer rural settings. Residents who were more likely to rate poor innercity settings as desirable included women (28%, P=.03), noncitizen IMGs (35%, P=.01), and especially underrepresented minorities (52%, P<.01). Whereas about 90% or more of residents felt prepared to treat common clinical conditions, only 67% of residents in four primary care specialties felt prepared to counsel patients about domestic violence or to care for human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) or substance abuse patients (all 67%). Women were more likely than men to feel prepared to counsel patients about domestic violence (70% vs. 63%, P=.002) and depression (83% vs. 75%, P<.01). Underrepresented minority residents were more likely than other residents to feel prepared to counsel patients about domestic violence (P<.01) and compliance with care (P=.04). Residents with greater exposure to underserved groups were more prepared to counsel patients about domestic violence (P=.01), substance abuse (P=.01), and to treat patients with HIV/AIDS (P=.01) or with substance abuse problems (P<.01). This study demonstrates the need to expose graduate trainees to underserved populations and suggests a contininuing role of minorities, women, and noncitizen physicians in caring for low-income populations.
Teaching Caregivers to Implement Video Modeling Imitation Training via iPad for Their Children with Autism

Abstract Children with autism fail to imitate from an early age and this lack of imitation is a salient diagnostic marker for the disorder. For children with Autism Spectrum Disorder (ASD), increased imitation skills appear to be related to increased skill development in a variety of areas. Video modeling was recently validated as a technique to support imitation acquisition in young children with autism. The purpose of this research was to determine if there is a functional relation between caregiver implemented Video Modeling Imitation Training (VMIT) via iPad and increased imitation skills in young children with autism. In addition, a secondary analysis of language development after exposure to VMIT was also conducted. A multiple baseline design across four caregivers and their children with autism was implemented. Results indicated that all four caregivers were able to successfully create video models on an iPad when provided with minimal training and implement VMIT with fidelity for their children. All four children made substantial gains in their imitation skills during caregiver implemented treatment. Imitation skills maintained post treatment and, to varying degrees, generalized to imitation of live models. Expressive language skills increased to varying degrees for all participants.
Birth to death analysis of the energy payback ratio and CO2 gas emission rates from coal, fission, wind, and DT-fusion electrical power plants

The amount of electrical energy produced over the lifetime of coal, LWR fission, UP fusion, and wind power plants is compared to the total amount of energy required to procure the fuel, build, operate, and decommission the power plants. The energy payback ratio varies from a low of 11 for coal plants to a high of 27 for DT-fusion plants. The magnitude of the energy investment and the source of the various energy inputs determine the CO2 emission factor. This number varies from a low of 9 to a high of 974 tonnes of CO2 per GWeh for DT-fusion and coal plants, respectively.
Cosmic Abundance of Boron

All abundances are expressed relative to a million atoms of Si. An average abundance of boron in ordinary chondrites is 6.2. The boron abundance in meteorites is highly variable. It has been found that the abundances in carbonaceous chondrites are very much higher than those in ordinary chondrites. The condensation of boron and beryllium from a cooling, low-pressure gas of solar composition is discussed together with the occurrence of boron in the interstellar medium, questions of element abundances in the sun, problems of boron production by cosmic rays, and boron production from supernovae.
Effects of lipids and processing conditions on lipid oxidation of extruded dry pet food during storage

Abstract Effects of fat type (beef tallow and poultry fat), fat content (0–0.75 g kg −1 ) and processing conditions (initial moisture: 1.6–2 g kg −1 ; screw speed: 200–400 rpm) on lipid oxidation of extruded dry pet food were studied. The results showed that the lipid oxidation rate constant of the extruded dry pet food was a function of fat types, added fat content and feed moisture content. Control (no fat) samples had the highest lipid oxidation rate, as compared to the samples with fat addition. Samples with poultry fat had a higher lipid oxidation rate than those with beef tallow addition. Samples containing a higher fat content resulted in a lower rate of lipid oxidation during storage. Feed moisture content had the same effect as the fat content; the extrudates with a higher moisture content resulted in a lower lipid oxidative rate. Pet foods extruded at 300 rpm had a significantly higher lipid oxidation rate than the ones produced at 200 and 400 rpm. Lipid oxidation of the extrudates appeared to be affected mainly by the degree of extrudate expansion. Products with a higher degree of expansion, which had larger cells and thinner cell walls, were more susceptible to oxidation.
Pulmonary arterial hypertension in a patient with Cowden syndrome and the PTEN mutation.

AbstractThe pathogenesis of pulmonary arterial hypertension (PAH) exhibits many neoplastic-like features. Cowden syndrome is a difficult-to-recognize heritable cancer syndrome caused by a germline mutation in the phosphatase-and-tensin homolog deleted on the chromosome 10 (PTEN) gene. PTEN regulation has been implicated in cancer development and, more recently, PAH pathogenesis. Here we report a case of PAH in a patient with Cowden syndrome and the response to pulmonary vasodilators.
Changes in the Gardens of Science, Wrought by Women

N long ago, in a symposium held here by the New York Academy of Sciences on The Flight from Science and Reason, I gave a paper titled “Imaginary Gardens with Real Toads.” What I have to say in this paper might be called “Creeping Toward Inclusivity in Science, Despite Persistent Toads.” By means of some stories—chiefly personal experiences—and a few statistics, I want to offer homage to intrepid activists who catalyzed remarkable changes. Within a single generation, these changes have greatly enhanced opportunities for women in many professions, especially science. Although optimistic about future prospects, I must also point out some daunting toads and serpents lurking in the gardens of science. These challenge the rising generation of young scientists to be no less intrepid. Much that is unthinkable today was almost unquestioned 25 or 30 years ago. Here are some examples that impressed me back then. All pertain to curious practices that persisted until the late 1960s or early 1970s. On a visit to Oberlin, my hosts proudly told me that it was the first college in the United States to offer coeducation. However, I was amazed to learn that a laundry service was provided for men students but not for women students. Closer to home, Harvard did not allow Radcliffe women to study in Lamont library, which is specifically for undergraduate use, on grounds that women would distract the men from scholarly pursuits. That policy was abruptly abandoned when Radcliffe built Hilles Library, bigger and better. Closer yet to home, I remember that Bell Labs offered jobs to two newly minted Ph.D.s from the same research group in the Harvard Chemistry Department. This dismayed everyone who knew of it, because Bell did not want to hire the more promising of the two, a woman, as a staff scientist but only as a librarian. Of course, in the wider world such things were also pervasive. For instance, the Boston Symphony Orchestra, like other major orchestras, had hardly any women musicians. Now there are many, but that did not come about until the practice developed of having final auditions behind a screen. Even then, the women finalists had to learn not to enter wearing distinctly audible shoes.
Once Intrepid Warriors: Gender, Ethnicity, and the Cultural Politics of Maasai Development.

Once Intrepid Warriors: Gender, Ethnicity, and the Cultural Politics of Maasai Development. Dorothy L. Hodgson. Bloomington: Indiana University Press, 2001. ix. 333 pp., notes, bibliography, index.
Is there a spatial correlation in the distribution of adsorbed atoms in the cages of a zeolite

Monte Carlo simulations of the cage-to-cage jumps of Xe atoms in a crystalline zeolite using the experimentally observed molecular rate constants for cage-to-cage jumps were carried out to determine if there is a systematic spatial correlation of the distributions of Xe atoms among the cages at equilibrium. The neighbours of cages having an Xe occupancy that is less than the average occupancy are found to have distributions that are skewed toward higher occupancy compared with the overall distribution. On the other hand, the neighbours of cages having an Xe occupancy that is greater than the average occupancy are found to have distributions that are skewed toward lower occupancy than the overall distribution.
Decomposition of the focusing transformation in coherent signal-subspace DOA estimation

A decomposition of the focusing transformation matrix needed in the coherent signal-subspace method of H. Wang and M. Kaveh (IEEE Trans. ASSP, vol.ASSP-33, no.4, p.823-31, Aug. 1985) is presented. The decomposition yields a structure for implementing the space-time domain filter needed to preprocess the array data prior to the direction of arrival (DOA) estimation step. The resulting structure uses blocking matrices and steering matrices as modules to give a simples preprocessing filter. This structure is compared to a previously published multichannel filter design. >
A Randomized Comparative Trial of Two Decision Tools for Pregnant Women with Prior Cesareans

ABSTRACT Objective Evaluate tools to help pregnant women with prior cesareans make informed decisions about having trials of labor. Design Randomized comparative trial. Setting A research assistant with a laptop met the women in quiet locations at clinics and at health fairs. Participants Pregnant women ( N = 131) who had one prior cesarean and were eligible for vaginal birth after cesarean (VBAC) participated one time between 2005 and 2007. Methods Women were randomized to receive either an evidence-based, interactive decision aid or two evidence-based educational brochures about cesarean delivery and VBAC. Effect on the decision-making process was assessed before and after the interventions. Results Compared to baseline, women in both groups felt more informed ( F = 23.8, p F = 9.7, p = .002), felt more supported ( F = 9.8, p = .002, and overall reported less conflict ( F = 18.1, p F = 9.8, p = .003). Conclusion Although both decision tools significantly reduced conflict around the birth decision compared to baseline, more work is needed to understand which format, the interactive decision aid or paper brochures, are more effective early and late in pregnancy.
Coolability of layers of molten reactor material

Chapter 15 is devoted to the coolability of layers of molten nuclear reactor material. Such physics is important for designing of stabilization of spread melt in reactor compartments. After defining the problem with its boundary conditions and some simplifying assumptions the system of differential equations describing the process is presented: mass and energy conservation. The following effects are taken into account: the molten steal dropped in the melt or originating inside the melt; the gas release from a sub-layer; the viscous layer; the crust formation; the buoyancy driven convection; the film boiling; the heat conduction through the structures; oxide crust formation on colder heat conducting structures. The existence of a metallic layer is also considered. Some test cases are presented to make easy the application of the presented models: oxide over metal and oxide besides metal. A simple model for gravitational flooding of hot solid horizontal surface by water leading to hyperbolic system is also presented.
Expression of GRP and Its Receptor in Well-differentiated Colon Cancer Cells Correlates with the Presence of Focal Adhesion Kinase Phosphorylated at Tyrosines 397 and 407

Gastrin-releasing peptide (GRP) and its receptor (GRP-R) are not normally expressed by epithelial cells lining the colon but are aberrantly expressed in cancer, where they act as morphogens and regulate tumor cell differentiation. Studies of colon cancer formation in mice genetically incapable of synthesizing GRP-R suggested that this receptor's morphogenic properties were mediated via focal adhesion kinase (FAK). We therefore set out to determine the presence of both total and phosphorylated forms of FAK in human colon cancer specimens as a function of tumor cell differentiation and GRP/GRP-R co-expression. Ten colon cancers containing 25 regions of distinct differentiation were randomly selected from our GI Cancer Tumor Bank. All specimens were immunohistochemically probed using antibodies recognizing GRP, GRP-R, total FAK, and FAK specifically phosphorylated at tyrosine (Y) 397, 407, 576, 577, 861, and 925. Antibody-specific chromogen was determined by quantitative immunohistochemistry (IHC) for each region of defined differentiation. Here we confirm that GRP/GRP-R co-expression is a function of differentiation, with highest levels observed in well-differentiated tumor cells. We also show that the amount of total FAK and of FAK phosphorylated at Y397 and Y407 tightly correlates with differentiation and with the amount of GRP/GRP-R co-expression. These findings are consistent with GRP/GRP-R acting as a morphogen by activating FAK, and suggest that this occurs via phosphorylation of this enzyme at two specific tyrosine residues.