cssi/SciSciGPT-SciSciNet huggingface dataset:
High speed solvating gas chromatography using packed capillaries containing sub-5 μm particles

Abstract In this study, fused-silica capillaries of 250 μm I.D. were packed with spherical porous and nonporous octadecyl bonded silica particles having diameters of 1.5 and 3 μm. These capillaries were used with CO 2 as mobile phase at elevated temperatures. At the column inlet, the mobile phase was a supercritical fluid, while at the column outlet, it was a gas. The mobile phase gradually changed from a supercritical fluid to a gas within the column. Because the mobile phase exhibited solvating ability for the analytes being separated, in contrast to conventional gas chromatography (GC) in which the mobile phase is only a carrier, this variation has been named “solvating gas chromatography” (SGC). Using this technique, capillaries packed with small particles produced column efficiencies as high as 1200 plates s −1 for retained solutes. Therefore, packed capillary SGC is the method of choice to carry out high speed GC separations. The effects of column inlet pressure, column length and particle characteristics on mobile phase linear velocity, retention factor, column efficiency, speed of analysis and resolution were investigated.
Canadian vegetation sensitivity to projected climatic change at three organizational levels

The potential equilibrium response of Canadian vegetation under two doubled-CO2 climatic scenarios was investigated at three levels in the vegetation mosaic using the rule-based, Canadian Climate-Vegetation Model (CCVM) and climatic response surfaces. The climatic parameters employed as model drivers (i.e., degree-days, minimum temperature, snowpack, actual evapotranspiration, and soil moisture deficit) have a more direct influence on the distribution of vegetation than those commonly used in equilibrium models. Under both scenarios, CCVM predicted reductions in the extent of the tundra and subarctic woodland formations, a northward shift and some expansion in the distributions of boreal and the temperate forest, and an expansion of the dry woodland and prairie formations that was especially pronounced under one of the scenarios. Results of the response surface analysis suggest the potential for significant changes in the probability of dominance for eight boreal tree species. A dissimilarity coefficient was used to identify forest-types under the future climatic scenarios that were analogous to boreal forest-types derived from cluster analysis of the current probabilities of species dominance. All of the current forest-types persisted under the doubled-CO2 scenarios, but ‘no-analog’ areas were also identified within which an empirically derived threshold of the distance coefficient was exceeded. Maps showing the highest level in the vegetation hierarchy where change was predicted suggest the relative impact of the response under the two climatic scenarios.
Back to the Future: A Critique of Response to Intervention's Social Justice Views

The emergence of Response to Intervention (RTI) anticipates a different future for all students, particularly learners from racial minority backgrounds and students with disabilities. RTI is being widely adopted in school districts as a viable alternative to enhance learning opportunities; hence, some education scholars argue it promises a much-needed response to longstanding injustices for underserved students. RTI aims to address injustices in the distribution of educational opportunities and recognition of underserved groups of students. The authors identify the underlying views of social justice that permeate RTI and conclude with a closer look at RTI's justice claims embedded in some implementation procedures. They propose it is important to revisit the anticipated future promised by RTI through the refinement of the social justice perspectives used in this literature.
Growth and Tissue Lipid Deposition of Broilers Fed α-Ketoisocaproic Acid

Dietary alpha-ketoisocaproic acid (KIC) was studied for effects on growth, feed efficiency, tissue cholesterol (TC) content, and immune response to a Newcastle disease virus (NDV) vaccination in broilers. In two experiments, broiler chicks were fed diets supplemented with graded levels of KIC to .54% of the diet. Feed efficiency, fat deposition, BW gain, and plasma cholesterol levels were determined at 3 wk. In a third experiment, broilers were fed diets supplemented with 0, .1, .2, and .4% KIC throughout the starter (0 to 3 wk), grower (3 to 6 wk), and finisher (6 to 7 wk) periods. Abdominal fat and plasma and breast TC were measured at 7 wk. In Experiment 4, levels of KIC to .6% were fed to broilers to determine TC content and to measure the immune response to NDV vaccination. Feed efficiency, BW gain, and percentage abdominal fat were not affected by KIC in any of the broiler experiments. The addition of KIC to broiler diets resulted in a significant reduction in breast (Pectoralis major) TC. Biceps (Biceps femoralis) TC, adductor (Pubo-ishio-femoralis) TC, and plasma cholesterol content was not affected by KIC. Geometric mean titers to NDV were not improved by KIC. The data indicate that KIC has no effect on growth or abdominal fat deposition, but may have a role in TC homeostasis.
Rapid thermal processing for silicon nanoelectronics applications

Single-wafer rapid thermal processing, which has become indispensable in the present-day manufacture of integrated circuits, has replaced batch furnace processing to satisfy device and production requirements for reduced thermal budget, process uniformity, high throughput, ease of process development, and low manufacturing cost. To meet the requirements for critical applications, rapid thermal annealing (RTA) techniques have been developed. For example, RTA is used to form ultrashallow junctions in complementarymetal-oxide semiconductor transistors with 10-nm-scale gate lengths. This paper discusses approaches to realize the needed rapidity and uniformity in RTA processes, some of which combine radiative, convective, and conductive heat transfer, to control the rapid thermal cycling of silicon wafers for various processes requiring peak temperatures in the range of 200°C to 1,350°C.
THE AB-INITIO APPROACH TO NUCLEAR MATTER AND ITS EXTREME STATES

In this talk, I will review several issues related to the nuclear matter equation of state, with particular emphasis on isospin-asymmetric matter. I will stress the importance of pursuing a microscopic approach towards a better understanding of dense and exotic matter.
Intracranial Implantation with Subsequent 3D In Vivo Bioluminescent Imaging of Murine Gliomas

The mouse glioma 261 (GL261) is recognized as an in vivo model system that recapitulates many of the features of human glioblastoma multiforme (GBM). The cell line was originally induced by intracranial injection of 3-methyl-cholantrene into a C57BL/6 syngeneic mouse strain (1); therefore, immunologically competent C57BL/6 mice can be used. While we use GL261, the following protocol can be used for the implantation and monitoring of any intracranial mouse tumor model. GL261 cells were engineered to stably express firefly luciferase (GL261-luc). We also created the brighter GL261-luc2 cell line by stable transfection of the luc2 gene expressed from the CMV promoter. C57BL/6-cBrd/cBrd/Cr mice (albino variant of C57BL/6) from the National Cancer Institute, Frederick, MD were used to eliminate the light attenuation caused by black skin and fur. With the use of albino C57BL/6 mice; in vivo imaging using the IVIS Spectrum in vivo imaging system is possible from the day of implantation (Caliper Life Sciences, Hopkinton, MA). The GL261-luc and GL261-luc2 cell lines showed the same in vivo behavior as the parental GL261 cells. Some of the shared histological features present in human GBMs and this mouse model include: tumor necrosis, pseudopalisades, neovascularization, invasion, hypercellularity, and inflammation (1). Prior to implantation animals were anesthetized by an intraperitoneal injection of ketamine (50 mg/kg), xylazine (5 mg/kg) and buprenorphine (0.05 mg/kg), placed in a stereotactic apparatus and an incision was made with a scalpel over the cranial midline. A burrhole was made 0.1 mm posterior to the bregma and 2.3mm to the right of the midline. A needle was inserted to a depth of 3mm and withdrawn 0.4 mm to a depth of 2.6 mm. Two μl of GL261-luc or GL261-luc2 cells (10(7) cells/ml) were infused over the course of 3 minutes. The burrhole was closed with bonewax and the incision was sutured. Following stereotactic implantation the bioluminescent cells are detectable from the day of implantation and the tumor can be analyzed using the 3D image reconstruction feature of the IVIS Spectrum instrument. Animals receive a subcutaneous injection of 150 μg luciferin /kg body weight 20 min prior to imaging. Tumor burden is quantified using mean tumor bioluminescence over time. Tumor-bearing mice were observed daily to assess morbidity and were euthanized when one or more of the following symptoms are present: lethargy, failure to ambulate, hunched posture, failure to groom, anorexia resulting in >10% loss of weight. Tumors were evident in all of the animals on necropsy.
A new scaling along the spike of the Mandelbrot set

Abstract Using the zeros of a family of real polynomials, we locate a sequence of midgets along the spike of the Mandelbrot set. By this method we can readily find midgets (tiny copies of the Mandelbrot set) of high cycle number; we include a picture of a 200-cycle midget magnified by a factor of 5.68 × 10 238 . The ratios of distances between the cardioid centers for successive midgets in this sequence exhibit an asymptotic scaling, as does the ratio of head-to-center distances. We present evidence supporting a pattern of scalings for some “generalized Mandelbrot sets.”
ZnxCd1 − xS as a heterojunction partner for CuIn1 − xGaxS2 thin film solar cells

Abstract Zinc cadmium sulfide (Zn x Cd 1 − x S) heterojunction partner layer prepared with chemical bath deposition (CBD) has exhibited better blue photon response and higher current densities due to its higher bandgap than that of conventional cadmium sulfide (CdS) layer for CuIn 1 − x Ga x S 2 (CIGS2) solar cells. CIGS2/Zn x Cd 1 − x S devices have also shown higher open circuit voltage, V oc indicating improved junction properties. A conduction band offset has been observed by J – V curves at various temperatures indicating that still higher V oc can be obtained by optimizing the conduction band offset. This contribution discusses the effect of variation of parameters such as concentration of compounds, pH of solution and deposition time during CBD on device properties and composition and crystallinity of film. Efficiencies comparable to CIGS2/CdS devices have been achieved for CIGS2/Zn x Cd 1 − x S devices.
A Resilient Hierarchical Distributed Loop Self-Scheduling Scheme for Cloud Systems

In heterogeneous distributed cloud systems, load balance, communication and synchronization overhead must be taken considered. A hierarchical distributed loop self-scheduling scheme is effective and efficient for scientific loop applications. In this paper, we propose a resilient hierarchical distributed loop self-scheduling algorithm suitable for heterogeneous cloud systems. This algorithm is intended to enable the algorithm to continue to work in the event that some virtual machines (VMs) are too slow or cease to respond. We tested our algorithm in a heterogeneous cloud system. The results show that our algorithm can achieve normal operation and good performance.
Linguistics and Composition Instruction: 1950-1980.

This article discusses the recommendations made by compositionists to import the findings of linguistics into composition instruction during the middle years of the twentieth century. The article c...
Singularity Analysis of Planar Cable-Driven Parallel Robots

It is well known that parallel robots may have singular configurations that can result in a loss of full control the mechanisms. This paper analyzes two different categories of singularities of planar cable-driven parallel robots with four or more cables. The unidirectional constraint of cables makes the singularity analysis of cable-driven parallel robots different from that of rigid-link parallel robots even if they have similar kinematical architectures. Based on their natures, singularities of cable-driven parallel robots are classified into two categories: the Jacobian singularity and the force-closure singularity. A Jacobian singularity occurs when the Jacobian matrix of a cable-driven parallel robot loses its full rank. Based on rank analysis of Jacobian matrix, a group of Jacobian singularities is reported with mathematical proof. When the Jacobian matrix of a cable-driven parallel robot has a full rank, the cables' inability to generate tension will lead to force-closure singularities, which can always happen to fully-constrained cable-driven parallel robots. An algorithm of identifying force-closure singularities of planar cable-driven parallel robots is proposed. Understanding of the natures of singularities is important for the design and control of cable-driven parallel robots.
Healthcare Experiences of Limited English-Proficient Asian American Patients

Background: Among patients with limited English-language proficiency (LEP), provider-patient language discordance is related to lower patient satisfaction. However, little is known about how language barriers are associated with specific patient experiences, and how these experiences in turn may influence patient satisfaction. Objective: To evaluate the degree of health education and the quality of interpersonal care that occurs during patient visits, and their associations with patient satisfaction, in LEP Asian American patients. Methods: A cross-sectional mail survey was conducted in 2746 LEP Chinese and Vietnamese patients aged ≥18 years from 11 community health centers in eight US cities. We examined self-reported healthcare experiences of LEP patients who had visits to a language concordant (speaks the patient’s language) or discordant (does not speak the patient’s language) provider over the previous month. Multivariable logistic regressions were conducted to examine the associations between interpersonal care, discussions of health-related behaviors, and patient satisfaction. Results: Discussions of health-related behaviors and the quality of interpersonal care received were independent predictors of patient satisfaction (p<0.001). For language-discordant visits without access to an interpreter, patients who received poor-quality interpersonal care were more likely to be dissatisfied with the visit (adjusted odds ratio [AOR] 2.44; 95% CI 1.67, 3.57) and with the provider (AOR 4.43; 95% CI 1.71, 11.48) [both p<0.01]. Conclusions: Improving the quality of interpersonal care and the degree of health-related discussions may result in greater satisfaction among LEP patients. The quality of the provider’s interpersonal care is especially important to patient satisfaction. Interpreter services may alleviate some disparities in care.
Recurrence of Reinforced Random Walk on a Ladder

Consider reinforced random walk on a graph that looks like a doubly infinite ladder. All edges have initial weight 1, and the reinforcement convention is to add $\delta > 0$ to the weight of an edge upon first crossing, with no reinforcement thereafter. This paper proves recurrence for all $\delta > 0$. In so doing, we introduce a more general class of processes, termed multiple-level reinforced random walks. Editor's Note . A draft of this paper was written in 1994. The paper is one of the first to make any progress on this type of reinforcement problem. It has motivated a substantial number of new and sometimes quite difficult studies of reinforcement models in pure and applied probability. The persistence of interest in models related to this has caused the original unpublished manuscript to be frequently cited, despite its lack of availability and the presence of errors. The opportunity to rectify this situation has led us to the somewhat unusual step of publishing a result that may have already entered the mathematical folklore.
Structural Studies of (Pyridine)3ZnFe(CO)4 and (Pyridine)(Neocuproin)CdFe(CO)4

The structure of the previously reported (py)3ZnFe(CO)4 (py = pyridine) has been determined, confirming the monomeric nature of this species. The complex has average Zn–N and Zn–Fe bond lengths of 2.0970(7) and 2.4017(3) A, and features a coordination geometry about Fe which is intermediate between trigonal bipyramidal and face monocapped tetrahedral. The space group is P21/c, with a = 8.22080(10) A, b = 16.1668(3) A, c = 15.4669(3) A, β = 102.5869(11)°, V = 2006.21(6) A3, Dcalc. = 1.558 g/cm3 at 150(1) K. A monomeric cadmium analogue, (pyridine)(neocuproin)CdFe(CO)4, has also been synthesized, and found to possess a similar geometry, with average Cd–N and Cd–Fe bond lengths of 2.352(2) and 2.5380(5) A. The space group is $$ P\overline{1} $$ with a = 10.8900(2) A, b = 11.3042(3) A, c = 15.5488(4) A, α = 85.1251(10)°, β = 84.3468(14)°, γ = 72.0377(15)°, V = 1808.93(7) A3, Dcalc. = 1.478 g/cm3 at 150(1) K. The structures of the monomeric (py)3ZnFe(CO)4 and (py)(neocuproin)CdFe(CO)4 complexes have been determined, and suggest the use of significantly greater s character in the main group elements’ bonds with iron as opposed to nitrogen.
The Biosurveillance Resource Directory - A One-Stop Shop for Systems, Sources, and Tools

In order to assess the utility and effectiveness of different data streams for global disease surveillance, a comprehensive survey of current human, animal, plant, and marine surveillance systems and data streams was undertaken. A relational database has been developed to allow for detailed analyses and searches of data streams and surveillance systems. A need for a biosurveillance one-stop shop has been increasingly called for to help in evaluating what data streams and systems are available and relevant for many different biosurveillance needs and goals. The prototype Biosurveillance Resource Directory is a searchable, dynamic database for biosurveillance system and source information.
Ventral medullary surface responses to hypoxic and hyperoxic transient ventilatory challenges in the cat

Abstract Carotid body afferent contributions to activity of the intermediate area of the ventral medullary surface (IVMS) following transient hypoxia and hyperoxia were examined in 6 spontaneously breathing, pentobarbital-anesthetized cats. Two tidal breaths of 100% N 2 , 100% O 2 , or room air, were randomly administered before and after carotid sinus denervation (CSD). Images of scattered light from the IVMS showed that activity increased with hypoxia (10.1 ± 2.4%), and decreased with hyperoxia (4.8 ± 1.8%). CSD significantly increased the magnitude and delayed the onset of the hypoxic response, but reversed the initial component of the hyperoxic response. We conclude that carotid body afferents modulate the magnitude and timing of IVMS responses to transient respiratory challenges.
SU‐GG‐T‐345: Verification of a Monte Carlo‐Based Source Model for a Varian 10 MV Photon Beam

Purpose: To apply a measurement‐driven source model using the Monte Carlo Dose Planning Method (DPM) dose calculation engine to a Varian 10 MV photon beam. Method and Materials: A measurement‐driven model using the DPM dose calculation algorithm is being extended from a Varian 6 MV photon beam to include Varian 10 MV, Elekta 6 MV and 10 MV, and Siemens 6 MV and 10 MV photon beams. The present work details the model commissioning for the Varian 10 MV photon beam. The multi‐source model consists of a primary photon point source, an extra‐focal exponential disk source, and an electron contamination uniform disk source. The model accounts for fluence and off‐axis energy effects due to the flattening filter. The photon energy spectra for the primary and extra‐focal sources are modeled by the statistical fatigue‐failure function combined with a Fermi‐cutoff function. The energy spectrum of the electron contamination source is modeled as an exponential distribution. Model parameters are determined by an optimization process that minimizes the differences between measurement and calculation. The set of standard measurements used for optimizing consists of the percent depth dose (PDD) and dose profiles in water for 10×10 cm2 and 40×40 cm2field sizes.Results: Comparisons between calculation and measurement of the PDD and dose profiles for the 10×10 cm2field size show agreement within ±2%/2 mm except for the off‐axis low dose regions where calculations underestimate the dose by up to 3% of dmax. Conclusion: This work demonstrates that the model, previously shown to be accurate for the Varian 6 MV beam, can be successfully extended to the Varian 10 MV photon beam. Work is ongoing to further refine and validate the model to include Elekta and Siemens linear accelerators.Conflict of Interest: Work supported by PHS CA010953, CA081647, and R01 CA85181 awarded by NCI, DHHS.
RoyoBlocks: an exploration in tangible literacy learning

One of the cornerstones of early childhood education is literacy education. However, this process is often presented linearly: reading comes first, writing comes second. This neglects the creative capacities of the child until he is fully capable of reading. This paper presents RoyoBlocks, a project that explores literacy learning through a set of tangible wooden word blocks and a plush reading companion. By incorporating wireless technology with traditional childhood toys, RoyoBlocks provide pre-literate leaners an opportunity to practice and hone both their reading and writing skills. In this paper, we discuss the learning processes that informed our design and the subsequent design decisions we made while developing RoyoBlocks.
Feasibility of running clinics to collect biological specimens in a nationwide cohort study- : Adventist health study-2

Purpose Collecting biologic and questionnaire data allows analyses that can include both genetic/biomarker and behavioral factors. Therefore, the feasibility of collecting biological specimens from a nationally dispersed cohort (Adventist Health Study-2) was tested. Methods We selected 2130 subjects from California, Washington, Texas, and Louisiana to simulate a widely scattered cohort. Clinics were held at local church halls. Nonclinic attendees were invited to mail in their blood samples. The remaining nonparticipants were offered a home visit by a venipuncturist. Results Sixty-four percent of nonblack and 38.4% of black invitees attended the clinics. Another 11.3% of nonblack and 5.9% of black subjects from a subsample mailed in their blood samples. A venipuncturist visit collected samples from another 5.3% of nonblack subjects, but hurricanes disrupted this method among blacks. This experience suggests that we could collect biological samples from 81.2% and at least 44.3% of the nonblack and black subjects, respectively. Conclusions We have demonstrated the feasibility of collecting biological specimens from black as well as nonblack subjects, with an efficient, cost-effective system, and limited personpower, overcoming many of the complexities imposed by scattered subjects, diversity of culture, as well as cumbersome and varied state legislation governing clinics and clinic personnel.
Proxies for Economic Freedom: A Critique of the Hanson Critique

Economic freedom indicators have become quite popular recently as a useful tool to quantify the relationship between a country's institutions and its prosperity. In a recent article, Hanson (2003) criticizes these types of studies for: (i) failing to adequately distinguish between different proxies for economic freedom, (ii) not considering the potential for endogeneity, and (iii) accepting significance of economic freedom's ability to promote prosperity even though regression analysis generates “nonsensical” results. Closer inspection reveals that most of his arguments are questionable, do not apply to much of the literature, or are not original, and that he is guilty of misinterpreting his own econometric evidence relating freedom to the level of GDP.
Primary amoebic meningoencephalitis

Case Presentation A 9-year-old female with an unremarkable past medical history presented to a Tyler, Texas emergency department with a 7-day history of worsening frontal headache and bilateral lower extremity “aches.” During the previous 4 days she had also experienced a cough, nasal congestion, and rhinorrhea. Her condition rapidly progressed to include an increasingly severe headache, photophobia, nonbloody emesis, neck pain, fever (103.6°F), irritability, and disorientation along with episodes of verbal outbursts, purposeless movements, and eye rolling. The patient underwent a lumbar puncture, and cerebral spinal fluid was analyzed with the following results: glucose 71 mg/dL (Normal 40-70 mg/dL), protein 148 mg/dL (Normal 15-45 mg/dL), nucleated cells 1080 cell/μL consisting of 69% neutrophils, 25% lymphocytes, and 6% monocytes (Normal up to 20 lymphocytes/μL in children), red blood cells 126 cells/μL (Normal no RBCs). A presumed diagnosis of bacterial meningitis was made and ceftriaxone was started. The patient was transferred to Children’s Medical Center of Dallas where her medical condition continued to deteriorate. A head-computed tomography was performed and revealed no abnormalities. Upon further questioning it was discovered that the patient had been swimming in an eastern Texas lake shortly before the onset of symptoms. This increased the suspicion for primary amoebic meningoencephalitis (PAM). Empiric intrathecal amphotericin B and systemic rifampin was initiated. Subsequent wet mount analysis of the CSF revealed Naegleria fowleri trophozoites, the etiologic agent of PAM. The patient’s condition continued to worsen and she died several days later. Clinical Background Etiology of PAM Primary amoebic meningoencephalitis is a rapidly progressive disease that generally results in death within 7 to 10 days of symptom onset. The etiologic agent is the freeliving amoeba Naegleria fowleri. Infection occurs most commonly in young, healthy individuals following exposure to contaminated water sources. Inoculation occurs when contaminated water is forced into the nasal cavity. Access to the CNS is achieved by invasion into the olfactory neuroepithelium with subsequent penetration of the cribriform plate. Once in the CNS, the organisms colonize cerebral gray matter leading to a rapidly fatal meningoencephalitis. The genus Naegleria contains several species of which N fowleri is the only known human pathogen. These protozoa are found ubiquitously in the environment and are distributed worldwide. They can be found in warm, stagnant bodies of water, and even chlorinated swimming pools, making contact with humans inevitable. Etiology of Primary Amoebic Meningoencephalitis (PAM) Laboratory diagnosis of PAM The need for early detection of PAM Differentiating Naegleria fowleri from Acanthamoeba species Treatment and Prognosis
High‐Performance Planar‐Heterojunction Solar Cells Based on Ternary Halide Large‐Band‐Gap Perovskites

DOI: 10.1002/aenm.201400960 red-shift beyond 1000 nm by partially replacing Pb 2+ with Sn 2+ . [ 12,13 ] Notably, the Sn 2+ cation has the tendency to oxidize to Sn 4+ and thus p-dope the perovskite, displaying metal-like conductivity. [ 12a ] However, the PCEs of the Sn-based perovskite solar cells encounter great losses when increasing the fraction of Sn 2+ due to poor perovskite fi lm formation and the instability of Sn 2+ . [ 12–15 ] Currently, successful demonstrations of Pb 2+
B large-cell lymphoma in children and adolescents

The prognosis of advanced B-large cell lymphoma (B-LCL) in children and adolescents has improved dramatically over the past 25 years (30-40% to 80-90% 5-year event-free survival (EFS)). Using strategies of treatment allocation based upon risk of disease recurrence, the total duration of therapy has been successfully reduced for many patients, and the prior requirement for radiotherapy largely eliminated. Instead of 18-30 months of combined chemotherapy and radiotherapy, current therapy has been decreased to between 6 weeks and 6 months of intensive chemotherapy. Multiagent chemotherapeutic approaches have been optimized with the use of moderate to high-dose methotrexate and further intensification with cytarabine and etoposide. The prognosis for children and adolescents who progress or relapse on current therapy for B-LCL, however, has decreased over the past 25 years with approximately 80% or 90% surviving at the present time. B-LCL in children and adolescents uniformly expresses CD20 and CD22 surface antigens. New treatment strategies employing targeted monoclonal antibody therapy combined with chemotherapy and targeted conjugated monoclonal antibody therapy conjugated with radioactive compounds and toxins are currently being investigated. Future studies utilizing immunophenotyping, cytogenetics, molecular genetics, and gene expression profiles (microarray) are required to better define the biological heterogeneity and differential clinical outcomes among children and adolescents with B-LCL.
Regulation of Purα gene transcription: Evidence for autoregulation of Purα promoter*

KAMEL KHALILI*Center for Neurovirology and Cancer Biology, Laboratory of Molecular Neurovirology,College of Science and Technology, Temple University, PhiladelphiaThe single-stranded DNA and RNA binding protein, Pura, has recently receivedspecial attention as this protein, by associating with the speciﬁc nucleotidesequence (GGN repeats) and/or several important cellular and viral proteinsregulates crucial biological events such as transcription, replication, and cellproliferation. In this study, we focused on the promoter activity of the Puraupstream DNA sequence and demonstrated that the sequence spanning 6,000nucleotides upstream of the Pura transcription start site has promoter activity invarious cell types. Results from promoter deletion studies revealed that this regionencompasses various regulatory motifs which differentially participate in thepromoter activity of Pura in various cells. The transcription start site of Pura issurroundedbytheGA/GC-richsequencewhichexhibitstheabilitytointeractwithPura, suggesting a role for autoregulation of Pura transcription. Results from co-transfection studies revealed that ectopic expression of Pura reduced transcrip-tional activity of the Pura promoter and the region located between amino acidresidues, 1–85 of Pura is important for the observed autoregulatory event. Theregulatory protein of the human neurotropic virus, JCV, T-antigen, which interactswith Pura, decreased transcriptional activity of the Pura promoter. Co-expressionof JCV T-antigen and Pura had no signiﬁcant effect on the suppression of Puragene transcription by either protein. The importance of this ﬁnding in light ofearlier results showing down regulation of Pura during JCV infection of glial cellsis discussed. J. Cell. Physiol. 186:406–413, 2001.
Toxicant-induced acceleration of epididymal sperm transit: androgen-dependent proteins may be involved.

Abstract Previously we established that a 4-d exposure to chloroethylmethanesulphonate (CEMS), a chemical that significantly reduces serum testosterone (T) levels, resulted in a significant decrease in cauda epididymal sperm reserves in adult male rats while homogenization-resistant testicular spermatid numbers were unaffected. This epididymis-specific alteration occurred whether or not circulating T levels were maintained using T-filled Silastic implants. To determine whether this epididymis-specific decrease in sperm number was the result of decreased epididymal transit time, the vas deferens was ligated at its midpoint just prior to the first of 4 d of exposure to CEMS with and without T implantation. If epididymal sperm transit was accelerated due to treatment, there would be fewer sperm in the caput/corpus and more sperm in the cauda/vas of the treated animals compared to control. The number of sperm in the caput/corpus decreased significantly (P
Identification of single-stranded DNA fragments of bacteriophage T5

Abstract Five fractions containing single-stranded fragments of bacteriophage T5 DNA were isolated by preparative agarose gel electrophoresis (bands I through V). The composition of these fractions and the arrangement of the fragments in the double-stranded T5 DNA molecule were determined, using DNA-DNA and DNA-RNA hybridization techniques and microscopic visualization of specific DNA-DNA reassociation products. The data confirm the previously proposed overall structure of T5 DNA and suggest the frequent occurrence of a further strand interruption in the pre-early section of the DNA. It was also found that only 20% of the molecules in band II are fragment IIb and more than 90% of the molecules in band V are fragment Va [fragments defined by Hayward, G. S., and Smith, M. G., J. Mol. Biol. 63, 383–395, 397–407 (1972); Bujard, H., and Hendrickson, H. W., Europ. J. Biochem. 33, 517–528 (1973)].
Effects of cortisone on thiamine-deficient young rats.

Summary(1) A total of 128 young male albino rats were used in 2 experiments to determine the effects of large doses of cortisone on thiamine requirements. They were fed a semi-synthetic ration from which thiamine was omitted for preliminary periods of either 10 or 18 days, followed by injections of 1 mg of cortisone daily with or without several levels of thiamine for another 18 or 12 days. (2) Pre-existent deficiency symptoms were aggravated by cortisone, resulting in decreased body growth and survival rate, priapism, cannibalism and loss of muscular coordination. The rats which were initially deficient in thiamine for the longer period, showed the most severe reactions to cortisone administration. Cortisone decreased the efficiency of converting food into body weight gains in all cases. (3) When 1 mg of thiamine per kilo of ration was fed, representing normal requirements for growing rats, there was little or no increase in body weight although most deficiency symptoms disappeared. When 5, 10 or 20 mg o...
Time to rethink the neural mechanisms of learning and memory

Most studies in the neurobiology of learning assume that the underlying learning process is a pairing – dependent change in synaptic strength that requires repeated experience of events presented in close temporal contiguity. However, much learning is rapid and does not depend on temporal contiguity, which has never been precisely defined. These points are well illustrated by studies showing that the temporal relations between events are rapidly learned- even over long delays- and that this knowledge governs the form and timing of behavior. The speed with which anticipatory responses emerge in conditioning paradigms is determined by the information that cues provide about the timing of rewards. The challenge for understanding the neurobiology of learning is to understand the mechanisms in the nervous system that encode information from even a single experience, the nature of the memory mechanisms that can encode quantities such as time, and how the brain can flexibly perform computations based on this information.
Infrared spectra of adsorbed films on metal mirrors

Abstract Reflection—absorption infrared spectroscopy has been used to determine the structure of films formed by dodecanoic acid and 1-octadecanol on polished iron and copper mirrors by adsorption from solution. In all cases the fatty molecules were adsorbed with the molecular axes essentially perpendicular to the surface of the substrate. Films formed by dodecanoic acid were characterized by broad infrared bands near 1580 and 1430 cm −1 that were assigned to the stretching modes of a carboxylate species. Films formed on copper slowly increased in thickness as immersion time was increased. At the same time, sharp bands appeared near 1590 and 1440 cm −1 indicating, perhaps, a slow reaction between the dodecanoic acid and the oxidized surface of the copper or the formation of an ionic film composed of discrete carboxylate ions and protons. The carboxylate films formed on iron mirrors were approximately monomolecular and showed little tendency to increase in thickness as immersion time was increased. Films formed by 1-octadecanol were essentially monomolecular and also showed little tendency to increase with immersion time. Some evidence for the inclusion of solvent in the 1-octadecanol films was obtained.
An Allele of an Ancestral Transcription Factor Dependent on a Horizontally Acquired Gene Product

Changes in gene regulatory circuits often give rise to phenotypic differences among closely related organisms. In bacteria, these changes can result from alterations in the ancestral genome and/or be brought about by genes acquired by horizontal transfer. Here, we identify an allele of the ancestral transcription factor PmrA that requires the horizontally acquired pmrD gene product to promote gene expression. We determined that a single amino acid difference between the PmrA proteins from the human adapted Salmonella enterica serovar Paratyphi B and the broad host range S. enterica serovar Typhimurium rendered transcription of PmrA-activated genes dependent on the PmrD protein in the former but not the latter serovar. Bacteria harboring the serovar Typhimurium allele exhibited polymyxin B resistance under PmrA- or under PmrA- and PmrD-inducing conditions. By contrast, isogenic strains with the serovar Paratyphi B allele displayed PmrA-regulated polymyxin B resistance only when experiencing activating conditions for both PmrA and PmrD. We establish that the two PmrA orthologs display quantitative differences in several biochemical properties. Strains harboring the serovar Paratyphi B allele showed enhanced biofilm formation, a property that might promote serovar Paratyphi B's chronic infection of the gallbladder. Our findings illustrate how subtle differences in ancestral genes can impact the ability of horizontally acquired genes to confer new properties.
Observation of configuration switching of the D center in a-Si:H

We report evidence for two configurations of the D − center in the same a-Si:H sample: one possessing the usual electron thermal emission energy of roughly 0.9 eV (D − ) and the other possessing a thermal emission energy between 0.6 to 0.7 eV (D − )*. The (D − )* state is observed soon after the capture of electrons into D o states within the deep depletion region of a Schottky barrier diode. As the time of occupation of the defect increases we observe that the emission rate decreases dramatically, implying a significant increase in its thermal emission energy. We have also found that this state exhibits an usually large optical energy threshold, near 1.3 eV. This implies a large degree of lattice relaxation between the (D − )* state and the conduction band.
Toward Earlier Identification and Development of Managerial Success

This paper summarizes the results of three published studies, emphasizing similarities among 30 successful and 30 less successful executives and dimensions of success for 350 male college students ...
Beyond Apologia: Racial Reconciliation and Apologies for Slavery

Reconciliation apologies such as Representative Tony Hall's proposed congressional apology for slavery and his own apology at a reconciliation conference in Benin, West Africa raise questions about the means and standards by which representative apologies for historic group offenses may prove satisfactory. This essay explores such questions in light of John Hatch's theory of reconciliation and an analysis of Hall's apology in the context of the Benin conference. In conversation with the work of Erik Doxtader, Mark McPhail, Aaron Gresson, and Nicholas Tavuchis, the essay clarifies ways in which a public reconciliation apology differs from traditional apologia and the unique challenges confronting public discourse for racial reconciliation in the US.
Cystic retrocerebellar malformations: unification of the Dandy-Walker complex and the Blake's pouch cyst

Twenty-six cases of developmental retrocerebellar cyst (RCC) formation are studied with respect to determining the usefulness and anatomic relevance of separate terms currently in use, including Dandy-Walker complex, Dandy-Walker malformation, Dandy-Walker variant, mega-cisterna magna (MCM), and Blake's pouch cyst. An anatomic and embryological continuum between Dandy-Walker complex and Blake's pouch cyst is proposed. A method for the useful assessment of RCC is outlined. The patency or closure of the aqueduct is crucial to the evaluation and management of hydrocephalus associated with RCC formation.
Synthesis and evaluation of optically pure [3H]-(+)-pentazocine, a highly potent and selective radioligand for σ receptors

Tritium-labeled (+)-pentazocine ([3H]-1b) of specific activity 26.6 Ci/mmol was synthesized in 3 steps starting with (+)-normetazocine (2) of defined optical purity. [3H]-1b has been characterized as a highly selective ligand for labeling of sigma receptors. Competition data revealed that [3H]-1b could be displaced from guinea pig brain membrane preparations with a number of commonly used sigma receptor ligands. [3H]-1b exhibited saturable, enantioselective binding with a Kd of 5.13 +/- 0.97 nM and a Bmax of 1146 +/- 122 fmol/mg protein. Phencyclidine (PCP) displaced [3H]-1b with low affinity while MK-801 was inactive, thus indicating insignificant activity at the PCP-binding site; apomorphine failed to displace [3H]-1b indicating lack of dopamine receptor cross-reactivity. Since the affinity of [3H]-1b is about 6 times that of the two commonly employed sigma ligands ((+)-3-[3H]PPP and [3H]DTG) and since it is more selective for sigma receptors than the benzomorphan [3H]SKF-10,047, it represents the first example of a highly selective benzomorphan based sigma receptor ligand. [3H]-1b should prove useful for further study of the structure and function of sigma receptors.
The raccoon spinocervical and spinothalamic tracts: a horseradish peroxidase study.

Abstract The locations of the cells of origin of the spinocervical tract (SCT) and spinothalamic tract (STT) were examined in relation to the somatotopic and laminar organization of the cervical enlargement of the raccoon dorsal horn (DH). In different animals, either the lateral cervical nucleus or the lateral thalamus was injected with a 2% solution of wheat germ agglutinin-horseradish peroxidase (WGA-HRP). Following 24 h or 4 days, respectively, the animals were sacrificed and both injection and target sites (spinal cord segments C6-T2) were processed using the TMB method. All labelled cells were counted in every fifth 50 μm section. Following injection of WGA-HRP into the lateral cervical nucleus, all labelled SCT cells were located ipsilateral to the injection sites. Most (84%) were in laminae III and IV, laminae known from other studies to contain cells preferentially responsive to light tactile stimulation, with very few (3%) in lamina I. Nearly 50% of labelled cells were located in the medial 1/3 of the DH, the region of representation of the glabrous surfaces of the raccoon forepaw. The mean number of labelled SCT cells per section was 4.19. After tracer injections of the lateral thalamus, more than 75% of STT cells were located contralateral to the injection sites. Forty-three percent were located in lamina I and 24% were in lamina V, laminae whose cells have been shown to be responsive to more intense forms of stimulation, as well as to light touch. Only 22% were located in the medial 1/3 of the DH. The mean number of labelled STT cells per section was 0.83. The results suggest that the SCT may play a more critical role in relaying discriminative light tactile and nociceptive information from the glabrous surfaces of the forepaw, but that there may be a greater role for the STT in relaying nociceptive information from the forelimb as a whole.
The effectiveness of the ragweed eradication campaigns in New York City; a 9-year study; 1946-1954.

Abstract 1.1. Approximately half of New York City's ragweed pollen is generated intramurally. The remainder is brought in by brisk western winds from New Jersey, Pennsylvania, and to a lesser degree from upper New York State. Hence, the total eradication of the ragweed within the city can at best reduce its atmospheric contamination with ragweed pollen by one-half. 2.2. On the basis of the reports of New York City's Health Department, indicating approximately a 50 per cent reduction in the city's ragweed acreage after nine years of "Operation Ragweed," it may be estimated that the city's ragweed pollen production may have been cut by one-half, thus reducing the pollen contaminating the air of the city by one-fourth. 3.3. During the nine years of "Operation Ragweed," pollen surveys were made under standard conditions at 30 stations in and around New York City, covering a total of 98 stations-seasons. The results of these surveys revealed no definite tendency for the pollen index of New York City as a whole, or of any city station, to decline during this period. 4.4. Comparisons of New York's pollen indices during this period with those of nearby New Brunswick, New Jersey, and Bridgeport, Connecticut, where there have been no elimination campaigns, afford no indication that the course of New York's index in recent years is deviating from that of its neighbors. 5.5. Pollen counts at the Brooklyn station made with the old counting technique over a period of eighteen years (1937–1954) reveal a 30.6 per cent decline in the average pollen index at this station during the nine-year period (1946–1954) while "Operation Ragweed" was in progress. During this same interval, however, there was also a pronounced decline in Brooklyn's vacant land, probably in excess of 60 per cent. Coincidently, there was, in addition, an inexplicable decrease of 30 per cent in the average incidence of stiff western winds during the active pollinating seasons when such winds contribute heavily to New York's ragweed counts. In the light of these important considerations, it may be estimated that only from one- to two-thirds, or from 10 to 20 per cent, of the 30.6 per cent decline in Brooklyn's index may be attributed to the effects of "Operation Ragweed." 6.6. The results obtained in Brooklyn are probably representative of those achived for the city as a whole. 7.7. New York is a coastal city and easterly and southerly winds blowing into the city on approximately one-third of its circumference are comparatively pollen-free. Inland communities would not benefit in this manner. 8.8. Since ragweed grows naturally and profusely in the New York Metropolitan Area, there is little likelihood that eradication campaigns, carried out along the lines of those employed at the present time, will succeed either in eliminating the weed completely and permanently from the city or in decisively reducing its pollen index.
The folding mechanism of a β-sheet: the WW domain

The folding thermodynamics and kinetics of the Pin WW domain, a three-stranded antiparallel β-sheet, have been characterized extensively. Folding and activation free energies were determined as a function of temperature for 16 mutants, which sample all strands and turns of the molecule. The mutational phi value (Φm) diagram is a smooth function of sequence, indicating a prevalence of local interactions in the transition state (TS). At 37 °C, the diagram has a single pronounced maximum at turn 1: the rate-limiting step during folding is the formation of loop 1. In contrast, key residues for thermodynamic stability are located in the strand hydrophobic clusters, indicating that factors contributing to protein stability and folding kinetics are not correlated. The location of the TS along the entropic reaction coordinate ΦT, obtained by temperature-tuning the kinetics, reveals that sufficiently destabilizing mutants in loop 2 or in the Leu7-Trp11-Tyr24-Pro37 hydrophobic cluster can cause a switch to a late TS. Φm analysis is usually applied “perturbatively” (methyl truncation), but with ΦT to quantitatively assess TS shifts along a reaction coordinate, more severe mutations can be used to probe regions of the free energy surface beyond the TS.