cssi/SciSciGPT-SciSciNet huggingface dataset:
Rethinking the Relationship Between Learning and Development: Teaching for Learning in Early Childhood Classrooms

Abstract This article challenges the overemphasis in early childhood education on young children's development and its relative inattention to their learning. The author argues that learning leads cognitive development, and that early childhood educators should be more centered on teaching for learning and less on facilitating development. An alternative framework for thinking about early childhood teaching is presented, including descriptions of curriculum, instruction, and assessment, which place children's learning at the center of early childhood practice.
Mathematics and Politics in the Soviet Union from 1928 to 1953

Abstract The paper describes the influence of politics on the life of Soviet mathematicians in Stalin's era 1928–1953, years that witnessed the full unfolding of the dictator's power. A few years following Stalin's death are also covered. Various publications, private manuscripts, and recollections of my own experiences at the University of Leningrad served as sources. Leading themes include the administrative talent of Egorov, Lusin's School, and the genius of Kolmogorov.
Nanoscale characterization of bone-implant interface and biomechanical modulation of bone ingrowth

Abstract Bone–implant interface is characterized by an array of cells and macromolecules. This study investigated the nanomechancial properties of bone–implant interface using atomic force microscopy in vitro, and the mechanical modulation of implant bone ingrowth in vivo using bone histomorphometry. Upon harvest of screw-type titanium implants placed in vivo in the rabbit maxilla and proximal femur for 4 weeks, nanoindentation was performed in the bone–implant interface at 60-μm intervals radially from the implant surface. The average Young's Moduli (E) of the maxillary bone–implant interface was 1.13 ± 0.27 MPa, lacking significant differences at all intervals. In contrast, an increasing gradient of E was observed radially from the femur bone–implant interface: 0.87 ± 0.25 MPa to 2.24 ± 0.69 MPa, representing significant differences among several 60-μm intervals. In a separate experiment, bone healing was allowed for 6 weeks for proximal femur implants. The right femoral implant received axial cyclic loading at 200 mN and 1 Hz for 10 min/d over 12 days, whereas the left femoral implant served as control. Cyclic loading induced significantly higher bone volume, osteoblast numbers per endocortical bone surface, mineral apposition rate, and bone formation rate than controls. These data demonstrate nanoscale and microscale characterizations of bone–implant interface, and mechanical modulation of bone ingrowth surrounding titanium implants.
Reproducibility of BOLD, Perfusion, and CMRO2 Measurements with Calibrated-BOLD fMRI

Abstract The coupling of changes in cerebral blood flow (CBF) and cerebral metabolic rate of oxygen (CMRO2) during brain activation can be characterized by an empirical index, n, defined as the ratio between fractional CBF change and fractional CMRO2 change. The combination of blood oxygenation level dependent (BOLD) imaging with CBF measurements from arterial spin labeling (ASL) provides a potentially powerful experimental approach for measuring n, but the reproducibility of the technique previously has not been assessed. In this study, inter-subject variance and intra-subject reproducibility of the method were determined. Block design %BOLD and %CBF responses to visual stimulation and mild hypercapnia (5% CO2) were measured, and these data were used to compute the BOLD scaling factor M, %CMRO2 change with activation, and the coupling index n. Reproducibility was determined for three approaches to defining regions-of-interest (ROIs): 1) Visual area V1 determined from prior retinotopic maps, 2) BOLD-activated voxels from a separate functional localizer, and 3) CBF-activated voxels from a separate functional localizer. For estimates of %BOLD, %CMRO2 and n, intra-subject reproducibility was found to be best for regions selected according to CBF activation. Among all fMRI measurements, estimates of n were the most robust and were substantially more stable within individual subjects (coefficient of variation, CV = 7.4%) than across the subject pool (CV = 36.9%). The stability of n across days, despite wider variability of CBF and CMRO2 responses, suggests that the reproducibility of blood flow changes is limited by variation in the oxidative metabolic demand. We conclude that the calibrated BOLD approach provides a highly reproducible measurement of n that can serve as a useful quantitative probe of the coupling of blood flow and energy metabolism in the brain.
Nonexistence theorems for asymptotically Euclidean Einstein-matter solutions.

Some nonexistence results are established for Euclidean wormholes,'' i.e., solutions of the Euclidean version of the Einstein-matter-field equations describing four-dimensional geometries with asymptotically Euclidean regions and matter fields satisfying appropriate falloff conditions in these regions. Our main result shows that no such solutions exist if the matter fields are conformally invariant. We also point out that in many nonconformally invariant cases (such as a scalar field with potential {ital V}({phi}) satisfying {phi} {ital dV}/{ital d}{phi}{gt}0) the matter-field equations alone suffice to rule out the possibility of solutions.
Phage tail-like particles kill Clostridium difficile and represent an alternative to conventional antibiotics.

Background Current Clostridium difficile infection (CDI) antibiotic regimens have become increasingly ineffective at achieving cure and preventing recurrence. A recently developed alternative to conventional antibiotics are phage tail-like particles (PTLPs), which are proteins that are morphologically similar to bacteriophages and are produced by C difficile . This study examines the in vitro killing spectrum of a previously unreported PTLP isolated from a clinical isolate of C difficile . Methods Using patient-derived samples from an institutional review board-approved C difficile tissue bank, a ribotype 078 C difficile isolate was anaerobically incubated on blood agar plates that were preswabbed with norfloxacin to induce the production of PTLPs. Concentrated PTLP populations were confirmed using transmission electron microscopy. Using a standard lawn spot approach, bactericidal activity was assessed as indicated by a clearing within the bacterial lawn. The PTLP genomic cluster was also fully sequenced and open reading frames were annotated according to predicted function. Results PTLPs were assessed using 64 patient-derived C difficile isolates of varying ribotypes. PTLPs demonstrated complete bactericidal activity in 21 of 25 ribotype 027 isolates with partial activity in 2 of the 25. Complete bactericidal activity was not demonstrated against any other ribotype or non- difficile bacteria, suggesting a species and ribotype specificity. Functional genes, which may be necessary for killing, were identified within the PTLP genetic locus. Conclusion PTLPs demonstrate capability in eradicating C difficile in vitro, and with further development, may represent an organism-specific, microbiome-sparing therapy for CDI.
CD8 T cell defect of TNF-α and IL-2 in DNAM-1 deficient mice delays clearance in vivo of a persistent virus infection.

DNAM-1 gene-deficient (−/−) mice take significantly longer to clear an acute and persistent LCMV infection in vivo than DNAM-1 +/+ mice. During acute LCMV priming, at the single cell level, DNAM-1 −/− mice made significantly less cytoplasmic CD8 TNF-α and IL-2 but not IFN-γ than their DNAM-1 +/+ counterparts. Restimulated immune memory CD8 T cells from DNAM-1 −/− and DNAM-1 +/+ mice were equivalent in cytolytic activity against LCMV-infected target cells but DNAM-1 −/− CD8 T cells had significant reductions in TNF-α and IL-2 that were associated on adoptive transfer with the inability to terminate the persistent viral infection.
Sex Differences Distinguish Intracortical Glutamate Receptor-Mediated Regulation of Extracellular Dopamine Levels in the Prefrontal Cortex of Adult Rats

Executive functions of the prefrontal cortex (PFC) are sensitive to local dopamine (DA) levels. Although sex differences distinguish these functions and their dysfunction in disease, the basis for this is unknown. We asked whether sex differences might result from dimorphisms in the glutamatergic mechanisms that regulate PFC DA levels. Using antagonists selective for α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) and N-methyl-d-aspartate (NMDA) receptors, we compared drug effects on in vivo microdialysis DA measurements in the PFC of adult male and female rats. We found that baseline DA levels were similar across sex, AMPA antagonism decreased PFC DA in both sexes, and NMDA antagonism increased DA in males but decreased DA in females. We also found that, at subseizure-producing drug levels, γ-aminobutyric acid (GABA)-A antagonism did not affect DA in either sex but that GABA-B antagonism transiently increased PFC DA in both sexes, albeit more so in females. Finally, when NMDA antagonism was coincident with GABA-B antagonism, PFC DA levels in males responded as if to GABA-B antagonism alone, whereas in females, DA effects mirrored those induced by NMDA antagonism. Taken together, these data suggest commonalities and fundamental differences in the intracortical amino acid transmitter mechanisms that regulate DA homeostasis in the male and female rat PFCs.
Ring destruction and carbide formation in niobium–PAH complexes

Abstract Gas phase complexes between niobium atoms and the polycyclic aromatic hydrocarbons (PAHs) pyrene (C16H10) and coronene (C24H12) are produced in a molecular beam using laser vaporization in a pulsed nozzle cluster source. Cation complexes are studied with time-of-flight mass spectrometry and mass-selected photodissociation. Mass distributions and fragmentation patterns for Nbx–(PAH)y complexes are significantly different from those found previously for other Mx–(PAH)y complexes. Masses indicating the formation of metal–hydrocarbons and metal–carbides are prominent. Larger complexes add intact PAH moieties to the strongly bound mono-metal adducts. Niobium is significantly more reactive with PAH species than other transition metals studied to date.
The perception of U.S.-Soviet intentions and other psychological dimensions of the nuclear arms race.

The build-up of our nuclear arsenal has created a new set of issues of particular concern to mental health professionals. These include: an understanding of the overwhelming scale of the medical emergency threatened by nuclear war or accident; the impact of the arms race on children and adolescents; the need to deal with various forms of fantasy and make-believe on the part of adults, in particular the effect of the nuclear responsibility on those in authority; and the need to find new ways of understanding and defining security in conflicted relationships.
Financial Education and Timely Decision Support: Lessons from Junior Achievement

Using data from a finance theme park at Junior Achievement of Southern California, we explore how timely decision support is impacted by previous exposure to financial education. Some students received a 19-hour curriculum before participating, and some did not. Trained students were more frugal, paid off debt faster, and relied less on credit financing. However, trained students purchased less comprehensive health insurance, exposing themselves to greater financial risk and wealth volatility. This disparity can be explained by differences in decision support within the park. As such, it appears that education and decision support should be considered complements, not substitutes.
The art of building LSIs

Today solid-state technology has improved to such a degree that very large IC chips are being made with yields up to 30 percent. This article highlights some of the main elements that determine whether LSIs can be manufactured in large quantities. The author claims that obtaining reasonable yields is readily achievable once the factors that stand out as deterrents to success are recognized. Previously developed manufacturing techniques are used for LSI production. In the future, however, lasers and the computer will be applied to enable engineers to produce components faster with greater reliability.
Suppression of hepatitis C virus (HCV) replication by hepatitis D virus (HDV) in HIV-infected hemophiliacs with chronic hepatitis B and C.

Most hemophiliacs who are coinfected with human immunodeficiency virus (HIV) and hepatitis C virus (HCV) have high serum levels of HCV RNA. To study the impact of multiple hepatitis virus infections, we evaluated all eight chronic carriers of hepatitis B surface antigen (HBsAg) from a previously studied cohort of 99 hemophiliacs with chronic HIV and HCV infections. Stored serum or plasma samples were tested for antibody to hepatitis D virus (anti-HDV) by ELISA; qualitatively for HCV RNA, HBV DNA, and HDV RNA by the polymerase chain reaction (PCR); and quantitively for HIV RNA, HCV RNA, and hepatitis B virus (HBV) DNA by a quantitative branched DNA signal amplification assay. HCV RNA was detected in only one of five patients with HDV infections on a cross-sectional study, and this individual had low levels ( 1.5 x 10(7) genome eq/ml) of HCV RNA. HIV RNA was present in all eight patients. There was no correlation between the level of HIV RNA and the presence of hepatitis viruses. Three of the eight patients (38%) died of liver failure and another has hypersplenism with hypoprothrombinemia. We conclude that HDV infection appears to suppress HCV replication and that liver failure is common in adult HIV-infected hemophiliacs with chronic HCV and HBV infections. These findings have implications for the therapy of HCV-infected hemophiliacs who are HBsAg positive.
Western Bioethics on the Navajo Reservation: Benefit or Harm?

Objective. —To understand the Navajo perspective regarding the discussion of negative information and to consider the limitations of dominant Western bioethical perspectives. Design. —Focused ethnography. Setting. —Navajo Indian reservation in northeast Arizona. Participants. —Thirty-four Navajo informants, including patients, biomedical health care providers, and traditional healers. Results. —Informants explained that patients and providers should think and speak in a positive way and avoid thinking or speaking in a negative way; 86% of those questioned considered advance care planning a dangerous violation of traditional Navajo values. These findings are consistent with hozho , the most important concept in traditional Navajo culture, which combines the concepts of beauty, goodness, order, harmony, and everything that is positive or ideal. Conclusions. —Discussing negative information conflicts with the Navajo concept hozho and was viewed as potentially harmful by these Navajo informants. Policies complying with the Patient Self-determination Act, which are intended to expose all hospitalized Navajo patients to advance care planning, are ethically troublesome and warrant reevaluation. ( JAMA . 1995;274:826-829)
Superconducting epitaxial Tl2Ba2CuO6 + δ thin films on SrTiO3 with tetragonal lattice and continuously adjustable critical temperature

Abstract Epitaxial Tl 2 Ba 2 CuO 6 + ° (Tl-2201) thin films on single crytalline SrTiO 3 substrate have been synthesized by RF magnetron sputtering followed by a two-step annealing process. X-ray diffraction data show that the film is c -axis oriented with full width at half maximum of rocking curve (FWHM) of 0.265° and alignment in the ab -plane. The zero-resistance T c of the same film can be increased or decreased continually and reversibly in the 11–80 K range by annealing in argon or air, with no change in tetragonal lattice symmetry.
Borderline science: Expert testimony and the Red River boundary dispute

The 1918 discovery of oil in the bed of the Red River, which forms the border between Texas and Oklahoma, led to a U.S. Supreme Court case that involved the extensive use of expert witnesses in fields such as geology, geography, and ecology. What began as a dispute between the two states soon became a multisided controversy involving those states, the federal government, Native Americans, and individual placer-mining claimants. After the federal attorneys introduced scientific experts into the dispute, including the plant ecologist Henry Chandler Cowles and the geographer Isaiah Bowman, fresh from negotiations at the Paris Peace Conference, Texas attorneys fielded their own team of opposing experts. Charged with the task of determining the location of the border, defined as the south bank of the river at the time of the 1819 treaty with Spain, the scientific experts presented the court with volumes of evidence and elaborate arguments, much of it contradictory and involving creative interpretations of existing theories. The case exhibited all the now-familiar features of a trial using expert witnesses, for which it represents an early, overlooked, and particularly complex example.
Tankyrase-1 polymerization of poly(ADP-ribose) is required for spindle structure and function

Tankyrase-1 polymerization of poly(ADP-ribose) is required for spindle structure and function
A new HaeIII polymorphism at the D21S13 locus.

DNA markers in the pericentromeric region of human chromosome 21 have shown linkage to a gene for Familial Alzheimer disease (FAD; St. George Hyslop et al. 1987). The limited informativeness of probes for the loci D21S13 and D21S16 have hindered precise mapping of the FAD locus and analysis of non-allelic heterogeneity in FAD (Schellenberg et al. 1988; St. George-Hyslop et al. 1987). We recently described a new EcoRII polymorphism at the D21S13 locus that was very informative in a large FAD pedigree (Pulst et al. 1990a, b). We now report another polymorphism for the D21S13 locus that further increases the informativeness of this locus.
Modeling and Sensitivity Analysis for Planning Decisions in Water Resources Expansion

ABSTRACT. Individuals and organizations concerned with the expansion of the facilities of a river basin (such as a river basin authority) need to determine optimal strategies of operation and capital investment. They also need to examine the sensitivity of whatever planning decisions are contemplated. This paper extends the applicability of an algorithm that had been previously applied to the deterministic river-basin expansion problem to include the feature of a sensitivity analysis. The algorithm, containing a partial enumeration search technique and a network analysis code, gave a construction sequence of reservoirs, canals, and treatment plants, and an operating policy that maximized the present value of net earnings consistent with certain underlying assumptions. A river basin was chosen that had an existing configuration of unregulated streams and rivers, reservoirs, canals and treatment plants, and sites for future additional facilities. A series of representative synthetic flow sequences, future demand profiles, interest rates and reservoir costs that served as inputs to or parameters in the system were each perturbed by various factors (for a total of 24 cases). The sensitivity studies showed that the immediate planning decision of what facility to construct next was insensitive to variations in future demands and costs and independent of later decisions. Thus, decision-making was adaptive in the sense that by always making the optimal proximate decision, the management of the river basin is optimized.
18F-FDG-avid sites mimicking active disease in pediatric Hodgkin's.

About 1,700 children in the United States are diagnosed yearly with lymphomas; Hodgkin’s disease accounts for approximately half of these cases, or 6% of all childhood cancers. Contemporary therapy allows for the achievement of remission in the majority of cases. The fusion of positron emission tomography (PET) with CT provides the most accurate imaging method for disease characterization and treatment response. However, experience with 18F-FDG PET-CT is limited in pediatric Hodgkin’s disease. Numerous non-oncologic processes can mimic recurrent or residual tumor. This pictorial addresses mimickers of disease such as uptake in normal structures, infections, transforming germinal canters and effects of therapy on normal tissues. It is essential for radiologists to be familiar with these findings in order to stage disease activity and therapeutic response accurately.
Prospective study of a fluocinolone acetonide implant for chronic macular edema from central retinal vein occlusion: thirty-six-month results.

Purpose To assess long-term visual outcomes and adverse events from a fluocinolone acetonide (FA) sustained drug delivery implant in eyes with chronic macular edema from central retinal vein occlusion (CRVO). Design Prospective interventional case series. Participants A total of 24 eyes of 23 subjects with vision loss associated with chronic macular edema from CRVO. Intervention Implantation of an intravitreal FA sustained drug delivery system. Main Outcome Measures The primary outcome measure was mean Early Treatment of Diabetic Retinopathy Study (ETDRS) visual acuity letter score at 36 months after implantation. Secondary outcome measures included number of subjects with ≥10-letter improvement in ETDRS letter score, central foveal thickness (CFT), total macular volume, and intraocular pressure (IOP). Results At 1, 2, and 3 years after implantation, mean visual acuity showed gains of 4.5 ( P = 0.52), 8.2 ( P = 0.07), and 3.4 ( P = 0.64) letters, respectively, and 32%, 56%, and 50% of study eyes, respectively, showed at least a 10-letter gain in ETDRS score. At these same time points, mean CFT improved by 247 (44%; P = 0.002), 212 (38%; P P Conclusions The FA drug delivery system provided sustained visual acuity and anatomic benefit in patients with macular edema from CRVO, and it has promise as a therapeutic option for selected patients with this condition. The main complications were cataract and elevated IOP. Financial Disclosure(s) The authors have no proprietary or commercial interest in any of the materials discussed in this article.
Colorectal cancer prevention 2000: screening recommendations of the American College of Gastroenterology

Colorectal cancer prevention 2000: screening recommendations of the American College of Gastroenterology
Oxygen diffusion in magnetite

The diffusion rate of oxygen in magnetite (Fe3O4) has been measured under hydrothermal conditions between 800° and 500°C at 1000 bars pressure, and yields the Arrhenius relation: D = 3.5 × 10−6 exp(−/45,000RT) kcal/g-atom O. The diffusion rate was found to be the same, within the estimated uncertainty of a factor of 2, for measurements at 100, 1000, and 2000 bars (20–200 MPa) water pressure, and for oxygen fugacities buffered by magnetite-hematite and approximately NiNiO. The activation energy and diffusion mechanism probably change to that given by Castle and Surman [10] at temperatures below 460°C. The oxygen diffusion rate in magnetite is between those of quartz and hornblende. Closure temperatures fall in the range 380°C for 0.1 mm radius grains cooling at 1°C/m.y. to 675°C for 1 mm radius and cooling at 1000°C/m.y. if the present data are used, but will be lower for the fine grain sizes and slow cooling rates if the Castle and Surman data are used.
Time-varying feedback control of nonaffine nonlinear systems without drift

Sufficient conditions are presented under which a general nonlinear system without drift is globally asymptotically stabilizable by time-varying state feedback. A novel approach is developed for the design of a time-varying smooth state feedback controller. The controller is explicitly constructed by using the bounded state feedback strategy (Lin, 1995, 1996) combined with Lyapunov technique as well as lossless systems theory. This work incorporates earlier global stabilization results (Coron, 1992; Pomet, 1992) for controllable affine systems without drift, which are known not to be smoothly stabilizable via any time-invariant state feedback.
The effect of esterases on 17α-hydroxyprogesterone caproate

Objective The aim of this investigation is to determine whether 17α-hydroxyprogesterone caproate is hydrolyzed, in vitro, to 17α-hydroxyprogesterone and caproate. Study Design The in vitro hydrolysis of dual radioactively labeled 17α-hydroxy-[ 3 H] progesterone [ 14 C] caproate by human plasma, hepatic and placental S9 fractions as well as recombinant esterases was investigated. The formation of [ 3 H]-17α-hydroxyprogesterone and [ 14 C]-caproate were determined with the use of high-performance liquid chromatography equipped with an online radioactivity detector. The presence and activity of carboxylesterase and butyrylcholinesterase in the human-derived preparations was confirmed by the hydrolysis of their prototypic substrates p -nitrophenyl acetate, p -nitrophenyl butyrate, and butyrylthiocholine, respectively. Results The aforementioned human-derived preparations hydrolyzed p -nitrophenyl acetate, p -nitrophenyl butyrate, and butyrylthiocholine. However, when 17α-hydroxyprogesterone caproate was incubated with the human-derived preparations under identical experimental conditions neither [ 3 H]-17α-hydroxyprogesterone nor [ 14 C]-caproate was detected. Conclusion 17α-hydroxyprogesterone caproate is not hydrolyzed in vitro by the esterase enzymes present in human plasma, liver, preterm, or term placenta.
Thermal Lensing in Cr2+:ZnSe Face-Cooled Disks

We report the experimental characterization and modeling of thermal lensing in Cr2+:ZnSe face-cooled laser disks using the phase shift interferometry technique. The thermal lens powers of the 1-mm and 0.5-mm thick disks were strong (37 and 19 diopters at 5 W pumping); the thermal lens power scaled with disk thickness and pump power; and temperatures were reached in the disks at which nonradiative relaxation is significant.
Experimental and theoretical studies of the elastic scattering of polarized neutrons from 6Li

Abstract The analyzing power of 6 Li for neutron scattering has been measured throughout the energy range 2–5 MeV and at four angles between 40° and 150°. The polarization of the neutron beam was absolutely determined using a neutron double-scattering method. The analyzing power of 6 Li was found to be remarkably constant in energy for all measured angles. A multi-level R -matrix analysis was performed of the analyzing power measurements. The p 3 2 state located at 3.5 MeV was found to have a width of 7.3 MeV and an s 3 2 state at 2.8 MeV, a neutron width of 3.5 MeV.
Ethanol and water capacities of alcohols : A molecular dynamics study

The extended hydrogen bond networks formed by alcohols are good indicators of their capacities to hold water. Results from molecular dynamics simulations on 24 linear alcohol isomers containing 6–12 carbon atoms show the effects of hydroxyl location on bulk hydrogenbonded structures. Calculated oxygen–oxygen radial distributions obtained from simulations were correlated to experimental liquid–liquid solvent extraction studies involving ternary water/ethanol/alcohol systems. It was found that hydroxyl group location determines the primary structure of the bulk alcohol’s hydrogen bond network and that an alcohol’s capacity for water correlates directly to the size of this network. 2006 Elsevier Ltd. All rights reserved.
Are Preschool/Day Care Personnel Ready for Non‐English‐Speaking Children?

0 The greatest development in language takes place between birth and 8 years of age. These early childhood years are crucial to all aspects of children's physical, emotional, social, and intellectual development (Bredekamp, 1987; McGee & Richgels, 1990; Perez & Torres-Guzman, 1992; Ziegler & Lang, 1991). An estimated 8 million children in the U.S. spend a part of those years in preschools or day care centers and many of them come from homes where a language other than English is spoken. Although it is difficult to estimate the numbers of non-English-speaking children in preschool/day care settings, the population of non-Englishspeaking children aged birth to 4 years in the U.S. was estimated to be 2.6 million in 1991 (Diaz Soto, 1991). For non-English speakers, preschool/day care settings may be the first encounters with an all-English-speaking environment. Children's attitudes toward and perceptions of not only self but schooling and their place in U.S. education begin to be formed by experiences in preschool/day care settings. Activities and climate must be developmentally appropriate for L2 learners in order to maximize their growth in all areas. This means that caregivers in preschool/day care settings must have some understanding of what is developmentally appropriate for L2 learners. Teachers who care for children learning an L2 in the preschool years should have an understanding not only of first language development but of second language acquisition (SLA) as well. Further, an awareness and understanding of the culture surrounding the students' L1 is also crucial to the cognitive, social, and emotional growth of children. What teachers of second language learners should know is well documented (Ada, 1986; U.S. Department of
Cognitive performance at school age of infants with bronchopulmonary dysplasia. |[bull]| 1179

The study hypothesis was that bronchopulmonary dysplasia (BPD) adversely affects cognitive performance at school age. This prospective cohort study examined three groups of children. Two groups were selected from a reconstructed cohort of very low birth weight (VLBW) infants previously enrolled in a multi-site, randomized, controlled, clinical trial. Group 1(n=311) included infants without BPD and group 2 (n=95) included infants with BPD. A control group of full term infants without BPD (group 3, n=188) was selected from a cohort assembled for a previous program supported by the Robert Wood Johnson Foundation. All of the children were assessed at 8-10 years of age in the following areas: full, verbal, and performance intelligence quotients (IQs), reading grade and age, math grade and age, and the Developmental Test of Visual-Motor Integration (VMI). Possible confounding variables were also recorded. Linear regression models were designed to determine the effect of BPD on the performance measures while controlling for confounding variables. Children in group 3 had the best performance and children in group 2 had the poorest performance on all eight cognitive measures. These differences were significant (p=0.0001) for the full IQ, performance IQ, reading grade and age, and math grade and age. Children in groups 3 and 1 performed better than children in group 2 for the verbal IQ(p=0.0001) and the VMI (p=0.0012), but for these two measures there was no significant difference in performance between children in groups 3 and 1. The 15 confounding variables affected scoring on each of the performance measures to varying degrees. Controlling for the confounding variables showed that levels of maternal education and history of cerebral palsy or hydrocephalus partially explained certain differences in performance between the three groups. In conclusion, the cognitive performance at school age of infants with a history of BPD was generally poorer than the performance of VLBW and full term children without a history of BPD.
Contributions of injured and intact afferents to neuropathic pain in an experimental rat model

This study was conducted to determine the contribution of peripheral inputs from injured and intact afferent fibers to behavioral signs of neuropathic pain, using a previously developed neuropathic rat model. Neuropathic injury was produced by tightly ligating the left L5 and L6 spinal nerves; this procedure induced rats to display neuropathic pain behaviors in the ipsilateral hindlimb. The behaviors included signs of mechanical and cold allodynia, as well as ongoing pain. Five days after neuropathic injury, peripheral inputs from injured segments (L5 and L6) or intact segments (L3 and L4) were blocked by either transection of the dorsal roots or application of a local anesthetic (bupivacaine) to the roots. Dorsal rhizotomy of the injured segments reduced all components of neuropathic pain behaviors. In contrast, dorsal rhizotomy of the uninjured segments abolished behavioral signs of mechanical and cold allodynia, but signs of ongoing pain were preserved. Blocking afferent inputs by application of bupivacaine mimicked the results of dorsal rhizotomy, in a reversible manner. These results suggest that afferent signals from injured and intact fibers play distinctively different roles in neuropathic pain: inputs from injured afferents maintain all components of neuropathic pain, while those from intact afferents mediate evoked pain such as mechanical and cold allodynia. An hypothesis is proposed to explain the results of the present as well as other published studies.
Observations of the advancing δ -ferrite/γ -austenite/liquid interface during the peritectic reaction

The peritectic transition, where δ -ferrite and liquid transform into γ -austenite, is an important aspect of product quality and process control in many ferrous and non-ferrous alloys. Due to the high temperatures at which the transition takes place, relatively little experimental work has been carried out to quantify the underlying phenomena. This paper presents recent work in visualizing the peritectic reaction stage of the transition. The visualization was carried out on the surface of hyperperitectic Fe-4.7 wt% Ni samples using a Confocal Scanning Laser Microscope (CSLM) equipped with a gold-image furnace. The focus of the research is to quantify the rate and shape evolution of the γ -austenite phase as it envelopes the δ -ferrite grains. Tip radii of 8 and 5 μ m were witnessed and it was found that, as these tips approached one-another their shape was altered and their growth rates decreased due to soft impingement of their respective diffusion fields. Comparing the separation distance at the point of soft impingement with the tip radius suggested a proportionality constant between tip radius of curvature and diffusion field size of between 1.1 and 1.3.
A new model for plasma transport and chemistry at Saturn

A model of plasma transport and chemistry is described which calculates the evolution of a plasma population in latitude and radial distance. This model is applied to the magnetosphere of Saturn, where it is used to fit the density profile of the heavy ions assuming both satellite and ring sources of plasma. Use of an extended source region is found to significantly alter the resulting plasma profile. Water ions cannot fit the observed density profile inside L = 6 even with a large ring source. Oxygen ions can fit the density profile throughout the region inside L = 12 given a suitable profile of neutral hydrogen; a suitable profile contains up to 5 H/cu cm outside L = 4 with the number increasing inside this. Preferred values of K are 1-3 x 10 exp -10 R(S)2/s, but any value K less than 10 exp -9 R(S)2/s can be accommodated. The temperature profile is shown to favor models invoking in situ plasma formation and loss as opposed to models where transport is important.
Velocity Field in Vortices Leeward of Islands

Abstract The Navier Stokes equation for an isolated axisymmetric viscous vortex is applied to determine the peak wind speeds in vortices leeward of the Gran Canaria, Tenerife and Madeira islands which are shown in TIROS and Gemini photographs of the region. The estimates of the wind speeds range from 2.6 to 6 m sec−1 (5–12 kt) for the clearly discernible vortices.
Applications of an Energy Transfer Model to Three Problems in Planetary Regoliths: The Solid-State Greenhouse, Thermal Beaming, and Emittance Spectra

Several problems of interest in planetary infrared remote sensing are investigated using a new radiative-conductive model of energy transfer in regoliths: the solid-state greenhouse effect, thermal beaming, and reststrahlen spectra. The results of the analysis are as follows: (1) The solid-state greenhouse effect is self-limiting to a rise of a few tens of degrees in bodies of the outer solar system. (2) Non-Lambertian directional emissivity can account for only about 20% of the observed thermal beaming factor. The remainder must have another cause, presumably surface roughness effects. (3) The maximum in a reststrahlen emissivity spectrum does not occur exactly at the Christiansen wavelength where, by definition, the real part of the refractive index equals one, but rather at the first transition minimum in reflectance associated with the transition from particle scattering being dominated by volume scattering to that dominated by strong surface scattering. The transparency feature is at the second transition minimum and does not require the presence of a second band at longer wavelength for its occurance. Subsurface temperature gradients have only a small effect on emissivity bands.
A Substance Abuse Consultation Service: Enhancing the Care of Hospitalized Substance Abusers and Providing Training in Addiction Psychiatry

The authors review the literature on the high prevalence but underrecognition of substance abuse among hospitalized patients and the general unavailability of hospital-based substance abuse consultation services. They describe the development, clinical operations, staffing, and teaching activities of a large substance abuse consultation service in one urban academic medical center and detail the service's growth and changing utilization patterns over an 8-year period, reporting the clinical characteristics of 1,819 patients seen over a 1-yearperiod. Differences in patient demographics, patterns of substance use, and diagnoses were highly significant from one referring service to another. The authors discuss the implications of such a service for patient care and teaching.
Bladder Outlet Obstruction in Women: Functional Causes

Bladder outlet obstruction (BOO) in women has received less focus in the past, as compared with BOO in men; however, more recently, studies have further examined BOO and voiding dysfunction in women to define the various etiologies, diagnostic criteria, and treatment strategies. The differential diagnosis in women is broad and includes anatomic, neurologic, and functional etiologies. This review focuses on the functional etiologies, including dysfunctional voiding, Fowler's syndrome, and primary bladder neck obstruction in adult women.
Skeletal calcium retention in osteoporosis and in osteomalacia.

A test for evaluation of the skeletal ability to attract and bind calcium is described. When applied under proper conditions, consistent results can be expected, the normal range being 40–60% retention of an infused load of calcium. Studies of 34 patients with osteoporosis revealed an increased skeletal avidity for calcium (as compared to the reduced bone mass) in the most common forms of this disorder, i.e., the postmenopausal and the Cushing's types. This, coupled with the finding of an elevation of alkaline phosphatase levels in the majority of these patients, suggests that an admixture of osteoporosis and osteomalacia may be more common than pure osteoporosis. In osteomalacia 2 different patterns were detected: In the vitamin D-deficient type the calcium retention and alkaline phosphatase levels were correspondingly increased. In glycosuric and in familial hypophosphatemic (“vitamin Dresistant”) osteomalacia, a disproportion was found between the high alkaline phosphatase activity in the serum and the...
Experimental evaluation of bird movements in a fragmented Neotropical landscape

Abstract The potential negative effects of forest fragmentation on animal movement and dispersal, and its consequences for population persistence, require an understanding of how modified landscapes affect movement decisions of forest species. We used a dispersal challenge experiment, whereby we released individuals of six bird species in a cattle pasture at different distances from forest edge (0, 50, 100 and 150 m), in a fragmented tropical landscape in Mexico to investigate the gap-crossing abilities and movement behavior of six species of tropical forest birds. Gaps as narrow as 50 m affected movement behavior of tropical forest birds. A sharp change in movement behavior in gaps 100 m and larger suggested the presence of a threshold distance beyond which birds are less likely to attempt and successfully navigate during trans-gap flights. Bird responses varied with degree of forest dependence: three forest-restricted species showed greater latency to cross gaps, independent of gap width, as compared with forest-unrestricted species. Gap width had a stronger effect on the orientation and destination of forest-restricted species than that of forest-unrestricted species. The concordance of our results with those found in species-distribution and radio-tracking studies indicates that dispersal challenge experiments provide reliable predictive information about response of forest birds to gaps between isolated forest fragments. In the landscape we studied, reducing gaps to no more than 50 m and providing corridors or shade trees between fragments should facilitate movements of forest birds.
Surgical competency in residents.

Purpose of the review To review the literature for recent work that will help educators develop programs to produce residents who are competent cataract surgeons. Recent findings Medical educators feel increasing pressure from the Accreditation Council for Graduate Medical Education (ACGME) to emphasize competence in our residency program graduates. Residency program director and resident graduate surveys show problems in our ability to produce cataract surgeons competent in all areas. The resident surgery learning curve increases the risk of complications in early cases. Several recent papers address curriculum development, which may be of interest to cataract teachers and program directors. Assessment of surgical skill continues to be an area of interest and has prompted some interesting work. The use of simulation with wet laboratories and computer devices is of increasing interest in an effort to hasten the learning curve. Summary An organized surgical curriculum with defined expectations using simulation and assessment tools will help residency programs meet ACGME mandates. A competent resident in cataract surgery will have to develop skills in all of the six ACGME competencies. Several recent articles address these issues.
Comparing Flexible Pavement Performance Using Emerging Analysis Tools

AbstractIn recent years, a variety of tools have been developed to assist in the analysis of flexible pavement service life in the United States. Although the output from many of the approaches is similar, each tool varies in the amount of testing effort, materials, and equipment necessary to arrive at the resulting predictions. Building upon the findings from research conducted in the National Cooperative Highway Research Program (NCHRP) Project 9-22B, this study focused on comparing flexible pavement performance predictions using three emerging analysis tools. One of the pavement analysis software packages, which considered the standard of, predicts performance in terms of incremental distresses and damage accumulation during a pavement’s service life. The other two programs are performance-related specification (PRS) tools that predict pavement performance in terms of service life factors. Three different asphalt mixtures were evaluated including a conventional mixture and two unconventional mixtures m...
Negotiating tension toward a hipper groove: Jazz improvisation as a metaphor within Christian ethics

Jazz improvisation provides the Church with two fruitful metaphors as it faces tension and conflict. First, the Church in conflict might view itself as an improvising jazz band – a community of tru...
Phase Inversion of Polybutadiene/Polyisoprene Blends under Quiescent and Shear Conditions

We investigate the effect of phase inversion on the domain morphology and rheological properties of phase-separated polybutadiene/polyisoprene blends using optical microscopy, light scattering, and rheometry. Two different blends, low-vinyl polybutadiene/low-vinyl polyisoprene (LPB/LPI) and low-vinyl polybutadiene/high-vinyl polyisoprene (LPB/HPI), were used in this study. The LPB/LPI blend has a lower critical solution temperature (LCST) of (62 ± 1) °C, while the LPB/HPI blend exhibits upper-critical-solution-temperature (UCST) behavior with a critical temperature above the experimentally accessible temperature window. We determine the quiescent phase-inversion composition (φLPI = 0.55 ± 0.05) of phase-separated LPB/LPI blends from the discontinuity in the dynamic storage modulus and shear viscosity. For LPB/HPI, we find that a shear-induced coexisting structure (apparent as a “walnutlike” light-scattering pattern) develops at a fixed composition (φHPI = 0.8) and constant temperature. The coexisting morp...
Spheres of teacher leadership action for learning

This paper offers a conceptual model and rich narratives that describe the contexts in which teacher leadership emerges and the many ways that leadership is enacted. Drawing on qualitative case studies of seven Maine, USA schools, the authors found that teachers initiated their own professional learning efforts with the central goal of improving the conditions and outcomes of student learning. Teachers were leading through their strong commitment to continued learning, and by modeling a willingness to take risks, to collaborate and to question existing practices. Teachers often began with a focus on their own learning and classroom teaching and later moved into other leadership spheres where they collaborated with and influenced colleagues and other stakeholders on a wider scale. When they encountered conflict, teachers found they needed to build both interpersonal and intrapersonal awareness and skills. This study broadens conceptions of what constitutes teacher leadership and professional development. T...
Effect of methyl parathion on food discrimination in northern bobwhite (Colinus virginianus)

The effect of methyl parathion on dietary discrimination ability was assessed in two-week-old northern bobwhite (Colinus virginianus). An initial oral dose of methyl parathion (0, 3 or 6 mg/kg: O,O-dimethyl O-(4-nitrophenyl) ester) was given to two subgroups of bobwhite before a 6-d food discrimination test; one group was tested with a choice of food treated with 45 ppm methyl parathion versus normal food and the second with a choice of 90 ppm treated food versus normal food. The average discrimination ratios (i.e., amount of treated to untreated food consumed) were used to indicate the chicks' ability to discriminate and avoid contaminated food. Chicks administered 6 mg/kg methyl parathion did not discriminate between treated and untreated food at either food treatment level and initially chose treated over untreated food (ratio = 1.28; p < 0.05). Brain cholinesterase activity in the 6 mg/kg groups averaged 50% of control levels, indicating high exposure to methyl parathion, which correlated with a behavioral disturbance (i.e., preference for treated food on day 1). Cholinesterase activity did not correlate with the discrimination ratios throughout the remainder of the 6-d exposure period due to the strong side preference that developed in the treated groups. This study demonstrates that feeding behavior and taste discrimination ability of bobwhite chicks was impaired due to exposure to methyl parathion.