cssi/SciSciGPT-SciSciNet huggingface dataset:
Impact of Near-Peer Education in a Student-Run Free Ophthalmology Clinic on Medical Student Teaching Skills

Objective To determine the impact of near-peer teaching experiences in the ophthalmology branch of the East Harlem Health Outreach Program (EHHOP), a student-run clinic, on teaching skills of fourth-year medical student Teaching Seniors (TS). Design Mixed-methods observational study, including online survey and telephone interview. Setting Student-run ophthalmology clinic affiliated with the Icahn School of Medicine at Mount Sinai and Mount Sinai Hospital, a tertiary-care center in New York, NY. Participants All EHHOP TS alumni from 2014 to 2019 were eligible for inclusion in our study. All 14 alumni participated in the survey, and 8 participated in the follow-up interview. Methods EHHOP ophthalmology TS alumni were surveyed via an online survey and subsequent, optional, individual telephone interview. The web survey queried former TS on the impact of EHHOP ophthalmology experiences on self-reported teaching skills and comfort with teaching. Quantitative analysis of survey questions and qualitative analysis of telephone responses was performed and analyzed for themes. Results Majority of participants reported increased comfort teaching ophthalmology concepts, teaching the slit-lamp exam, and serving as mentors as a result of their experience. Qualitative analysis of telephone interviews revealed 4 major themes: (1) TS were a self-selected group of individuals with prior interest in teaching, (2) Teaching experiences in EHHOP had a positive impact in many teaching-related domains, (3) TS perceptions of teaching skills gained did not necessarily align with junior students’ perceptions of teaching received, and (4) despite increased confidence and satisfaction with teaching experiences, TS desired more formal instruction in teaching. Conclusions While TS perceptions of teaching skills gained in EHHOP ophthalmology were overwhelmingly positive, TS still desired formal instruction in teaching. Additionally, the effectiveness of near-peer education in a subspecialty like ophthalmology, with limited formal curricular time, may be more effective later in training, when a more solid foundation of knowledge is acquired.
The Physics of Magnetic Resonance Imaging Safety

Magnetic resonance (MR) imaging relies on a strong static magnetic field in conjunction with careful orchestration of pulsed linear gradient magnetic fields and radiofrequency magnetic fields in order to generate images. The interaction of these fields with patients as well as materials with magnetic or conducting properties can be a source of risk in the MR environment. This article provides a basic review of the physical underpinnings of the primary risks in MR imaging to foster development of intuition with respect to both patient and risk management in the MR environment.
Synthesis and Characterization of 8-(6-Aminohexyl)-amino-NADH

8-(6-aminohexyl)-amino-NADH was successfully prepared by modifying NADH with 1,6-hexanediamine at the C8 position of adenine moiety. After 3-step synthesizing process, the product was purified on DEAE-Sepharose column with the final yield up to 60%. The stability of NH2(CH2)6NH-NADH in acid or neutral environment was studied and compared with the native NADH. The results showed that the modified NADH was more stable than the native one, particularly in the citric acid-sodium citrate buffer (pH 6.5) and phosphate buffer (pH 8.0), the half life of modified NADH increased 11.0 folds and 5.0 folds, respectively. Catalytic activity of the modified NADH was evaluated with lactate dehydrogenase (LDH) and glutamate dehydrogenase (GDH) systems. For LDH and GDH, the activity for NH2(CH2)6NH-NADH was 3.0～3.8 or 1.3～1.4 times higher than that of native NADH, respectively.
Collision Avoidance for Unmanned Aerial Vehicles in the Presence of Static and Moving Obstacles

This paper presents a new collision avoidance procedure for unmanned aerial vehicles in the presence of static and moving obstacles. The proposed procedure is based on a new form of local parametrized guidance vector fields, called collision avoidance vector fields, that produce smooth and intuitive maneuvers around obstacles. The maneuvers follow nominal collision-free paths which we refer to as streamlines of the collision avoidance vector fields. In the case of multiple obstacles, the proposed procedure determines a mixed vector field that blends the collision avoidance vector field of each obstacle and assumes its form whenever a pre-defined distance threshold is reached. Then, in accordance to the computed guidance vector fields, different collision avoidance controllers that generate collision-free maneuvers are developed. Furthermore, it is shown that any tracking controller with convergence guarantees can be used with the avoidance controllers to track the streamlines of the collision avoidance vector fields. Finally, numerical simulations demonstrate the efficacy of the proposed approach and its ability to avoid collisions with static and moving pop-up threats in three different practical scenarios.
A critical review and an extension of the political shirking literature

After substituting actual and real changes for proposed and nominal changes in budgetary and employment levels, it is clear that the size and scope of the federal Leviathon had not been reduced over 1982–83. It is also clear that the agencies which witnessed real budget cuts over this period were of minor importance in terms of the total U.S. budget. Future research on why only small agencies receive real budget cuts will provide us with a better understanding of the budgetary process.
QUALITATIVE DIFFERENCES IN GLUCOSE HOMEOSTASIS BETWEEN OBESITY OF PRADER-WILLI SYNDROME (PWS) AND NORMAL CHILDHOOD OBESITY (NL-OB)

Obesity is associated with insulin resistance and glucose intolerance. Our studies of Nl-ob and obese PWS children suggest another factor contributes to pathology of glucose homeostasis, in addition to increased adipose tissue. We studied 32 Nl-ob children (age 3-18 yrs) and 18 PWS children (age 6-19 yrs) given a mixed liquid "milkshake" meal (4 Kcal/kg). Serum levels of pancreatic polypeptide (PP), glucose (G), insulin (I) and gastric inhibitory polypeptide (GIP) were obtained at 0,15,30,45,60,90,120,180 min. There was no significant difference between weights of Nl-ob pts. (172±32%; mean±SD) and PWS pts. were 205±61% of ideal body weight for height. The PWS children with hyperphagia induced obesity had better glucose homeostasis and less insulin resistance than did the age matched, equally obese, normal children. Insulin resistance and glucose intolerance are not a uniform consequence of obesity; a reason for individual differences in susceptibility is not known. The differences between our groups may reflect a relative absence of an insulin hypersecretory-insulin resistance factor in the PWS group. Our data support the hypothesis that GIP hypersecretion may be causal. The PP deficiency may play a secondary role.
Regulation of Tumor Cell Dormancy by Tissue Microenvironments and Autophagy

The development of metastasis is the major cause of death in cancer patients. In certain instances, this occurs shortly after primary tumor detection and treatment, indicating these lesions were already expanding at the moment of diagnosis or initiated exponential growth shortly after. However, in many types of cancer, patients succumb to metastatic disease years and sometimes decades after being treated for a primary tumor. This has led to the notion that in these patients residual disease may remain in a dormant state. Tumor cell dormancy is a poorly understood phase of cancer progression and only recently have its underlying molecular mechanisms started to be revealed. Important questions that remain to be elucidated include not only which mechanisms prevent residual disease from proliferating but also which mechanisms critically maintain the long-term survival of these disseminated residual cells. Herein, we review recent evidence in support of genetic and epigenetic mechanisms driving dormancy. We also explore how therapy may cause the onset of dormancy in the surviving fraction of cells after treatment and how autophagy may be a mechanism that maintains the residual cells that are viable for prolonged periods.
Beyond Manzanar: Creating dramatic structure in Ergodic narratives

Interactive narrative requires new techniques in order to truly exploit the dramatic possibilities of the ergodic, first person experiential viewpoint. In the interactive 3D virtual reality installation Beyond Manzanar the author used concepts borrowed from music theory to focus dramatic development on the emotional states evoked in the user by interactions with the virtual environment. The piece explores parallels between the imprisonment of Japanese Americans at Manzanar Internment Camp in Eastern California during World War II, and Iranian Americans threatened with a similar fate during the 1979-’80 hostage crisis. Users experience the space in the perspective of the immigrant, their own movements triggering the dramatic inevitability of their own imprisonment.
Muscle and Tendon Heating Rates with Therapeutic Ultrasound in Horses

Objective To (1) determine the temperature change in equine tendon and muscle during therapeutic ultrasound and (2) develop guidelines for treating horses for muscular or tendinous injury using therapeutic ultrasound. Study Design Experimental, in vivo study. Animals Adult horses (n = 10). Methods Thermistors were inserted in the superficial and deep digital flexor tendons (SDFT and DDFT) of the thoracic limbs of 10 adult horses. On the left, 3.3 MHz therapeutic continuous ultrasound was done for 10 minutes at an intensity of 1.0 W/cm2 and for the right thoracic limb at 1.5 W/cm2. Thermistors were placed at 1 cm, 4 cm, and 8 cm depths in the epaxial muscles of the same 10 horses, for a 20-minute treatment at a frequency of 3.3 MHz and intensity of 1.5 W/cm2. Temperature was recorded before, during, and after treatment. Data were statistically analyzed. Results Mean temperature rise was 3.5°C in the SDFT and 2.5°C in the DDFT at the end of the 1.0 W/cm2 treatment (P = .94) and 5.2°C in the SDFT and 3.0°C in the DDFT at the end of the 1.5-W/cm2 treatment (P = .48). Mean temperature rise in epaxial musculature was 1.3°C at a depth of 1.0 cm, 0.7°C at 4.0 cm, and 0.7°C at 8 cm. Conclusions The SDFT and DDFT are heated to a therapeutic temperature using a frequency of 3.3 MHz and intensity of 1.0 W/cm2. The epaxial muscles are not heated to a therapeutic temperature using a frequency of 3.3 MHz and an intensity of 1.5 W/cm2.
The synthesis of certain disubstituted piperidines.

Several isomers of 2,6-bis-(1-hydroxyalkyl) piperidine hydrochlorides, in which the alkyl group is propyl, butyl, pentyl, hexyl, and benzyl have been prepared by hydrogenating the corresponding five 2,6-diacylpyridine intermediates. 3,5-Diphenylpieridine and a by-roduct, 2,4-diphenylpentamethylenediamine dihydrochlorde, were also prepared. The disubstituted piperidines are to be tested for pharmacological activity.
An Overview of Computer Technology Used in Ground Water Field Studies: Part I: Basics

There are many electronic tools available for ground water field studies including a wide variety of computer equipment. Consideration should be given to the use of computers when planning field studies. A foundation for determining the appropriate use of computers in field studies is presented in two parts. Part One includes a brief description of the components that comprise a computer and is intended to clarify terminology and illustrate the general characteristics of these machines. Related and frequently-used computer equipment is described in detail. Topics of special concern will be presented in Part Two, which will appear in the Spring 1984 issue, to alert the reader to common misconceptions and problems. This is illustrated by the description of two field studies.
SU-E-E-05: The Role of Conventional MR Physics, Resting State Functional MR Physics and MR Spectroscopy for the In-Situ Monitoring of Infarct and Peri-Infarct Tissue and for the Precise Diagnosis of Acute Ischemic Stroke

Purpose: There has been great interest to understand the detection mechanism of the growth of infarct region to periinfarct region (Perfusion Weighted Imaging, PWI and Diffusion weighted Imaging, DWI) in the brain of acute ischemic stroke patients using the principles of MR Physics as it would significantly affects the clinical diagnosis. Similarly, aiding resting state functional Magnetic resonance (fMRI) physics and MR spectroscopic (MRS) principles to the above to the diagnostic clinician will help as these mechanisms are more sensitive to the above changes due to the similar metabolic activity of the tissue under risk (periinfarct) and the dead tissue (infarct). This presentation aims to provide an overview of conventional principles (DWI and PWI) and emphasis the importance of resting state fMRI and MRS physics techniques for monitoring of infarct and peri‐infarct tissue along with the growth of infarct region.Methods and Results: Organization of Methods and Results: 1: IntroductionInfarct and peri‐infarct region activity after the acute stroke.2: Review of the MR physics role of DWI, PWI, resting state fMRI, MRS and their descriptions with specific examples.3: Detailed discussions on advantages and limitations of both conventional MR (DWI& PWI) and resting state fMRI and MRS physics techniques. Conclusion: The physics principles of monitoring resting state fMRI and MRS of the acute stroke patient along with the conventional MRI (PWI and DWI) can potentially help the clinical community in making precise diagnosis for the acute stroke patient.
Some experimental results for blast waves originating from a finite source

Die vorliegende Arbeit befasst sich mit der experimentellen Untersuchung der Ausbreitung von Stosswellen mittels einer Mehrfach-Funken-Kamera. Die Ermittlung der Ausbreitung des Stosswellenkopfes sowie der Stosswellengeschwindigkeit wird an zwei Beispielen demonstriert ferner werden die Stromungsverhaltnisse unmittelbar hinter der Stosswellenfront diskutiert.
Mass spectrometric detectors for samples separated by planar electrophoresis

Mass spectrometric detection for samples separated by planar chromatography (high-performance thin-layer chromatography and planar electrophoresis) has evolved over the past 10 years from concept to feasibility and to commercial availability. This review concentrates on the interface between planar electrophoresis and mass spectrometry. Although hardware aspects of the interface have been developed and refined over the past few years, and there are impressive demonstrations of feasibility, we are only beginning to exploit new methods in sample storage, preparation and reaction in conjunction with planar chromatographic separation, and new uses of complex multi-dimensional imaging data.
Wave Propagation Characteristics In Underground Power Cable

Calculations have been done to evaluate the effects of the semiconducting screens, the conductors, and the surrounding earth on the propagation constants of electromagnetic waves in concentric underground power cables. The theory, based on Maxwell's field equations, is reviewed. Results of calculations of both speed and attenuation are presented for a variety of practical configurations. Limited comparisons with experimental results are included. In addition to their direct application, the results can be employed to calculate the cable characteristic impedance from an algebraic expression which is presented.
Mechanics and Cytocompatibility of Genipin Crosslinked Type I Collagen Nanofibrous Scaffolds

Collagen is a principal constituent of the extracellular matrix (ECM) and as such, defines the microenvironmental milieu in which cells reside. In fiber-reinforced musculoskeletal tissues, collagen fibers are highly organized and generate the direction-dependent mechanical properties critical to the function of these structures. Given its primary role, collagen is particularly attractive for tissue engineering (TE) applications where scaffolds are coupled with cells to repair or regenerate damaged tissues. One method for producing collagen-based scaffolds is through electrospinning. This technique yields nano- to micron-scale fibers similar in diameter to those of the native ECM. Towards engineering orthopaedic tissues, methods have been devised to electrospin fibers into aligned arrays that can recapitulate the anisotropy of fiber-reinforced tissues [1]. While a number of polymers have been electrospun, collagen-based scaffolds are especially promising as they provide a biomimetic interface for cell attachment [2]. Numerous investigators have electrospun collagen [3], one major drawback is their inherent instability in aqueous environments. To address this, various crosslinking agents including glutaraldehyde (GA), 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride, and N-hydroxysuccinimide chemistries have been used, but these chemicals often prove cytotoxic or excessively laborious in application [4]. Even with crosslinking, dry as-formed nanofibrous collagen scaffolds with moduli greater than 50MPa diminish by 100-fold with rehydration [5].Copyright © 2008 by ASME
Radial diffusion assay of tissue collagenase and its application in evaluation of collagenase inhibitors

A radial diffusion assay for tissue collagenase (EC 3.4.24.3) has been devised which is simple, sensitive and capable of application to large numbers of samples. The assay employs an agarose matrix containing solubilized lathyritic rat skin collagen as substrate. Fibril formation is induced for 2 h at 37 degrees C subsequent to 41 h digestion at 28 degrees C. The procedure results in sharply defined zones of lysis which may be measured directly or after photography. The characteristics of the procedure are otherwise similar to those reported for other radial diffusion assays. The new method was used to examine the action of 10 compounds which were known or potential inhibitors of tadpole collagenase. The concentration of inhibitor required to produce 50% inhibition is reported for the following compounds: alpha2-macroglobulin, 142 microng/ml; N-acetylcysteine, greater than or equal to 100 mM; cysteine, 8.7 mM; EDTA, 0.46 mM; histidine, greater than or equal to 100 mM; 2,3-dimercaptopropanol, 0.5 mM and mercaptoacetic acid, 70 mM. The procedure also has potential for clinical determinations (e.g. tears, synovial fluid) since assay dishes may be prepared in advance and only 15 micronl of sample is required.
A Simplified RLS Algorithm and Its Application in Acoustic Echo Cancellation

In some adaptive filtering applications, the recursive least-squares(RLS) algorithm may be too computationally and memory intensive to implement.In this paper,a new RLS algorithm based on set membership with partial-update is presented.The new algorithm allows the reduction of the frequency of updates of the filter coefficients, where the filter coefficients are updated such that the output estimation error is upper bounded by a pre-determined threshold. Moreover,in this algorithm,the combination of the partial-update with set-membership focuses on updating a selected subset of the filter coefficients per iteration because the computational complexity is proportional to the number of filter coefficients.The resulting algorithm capitalizes not only from the sparse updating related to the set-membership framework but also from the partial update of the coefficients,reducing the average computational complexity.Simulation experiments in a typical echo cancellation environment confirm the effectiveness of the proposed algorithm.
Radio Afterglows of Gamma-Ray Bursts and Hypernovae at High Redshift and Their Potential for 21 Centimeter Absorption Studies

We investigate the radio afterglows of gamma-ray bursts (GRBs) and hypernovae (HNe) at high redshifts and quantify their detectability, as well as their potential usefulness for 21 cm absorption line studies of the intergalactic medium (IGM) and intervening structures. We examine several sets of source and environment model parameters that are physically plausible at high redshifts. The radio afterglows of GRBs would be detectable out to z ~ 30, while the energetic HNe could be detectable out to z ~ 20 even by the current Very Large Array (VLA). We find that the 21 cm absorption line due to the diffuse neutral IGM is difficult to detect even by the proposed Square Kilometer Array (SKA), except for highly energetic sources. We also find that the 21 cm line due to collapsed gas clouds with high optical depth may be detected on rare occasions.
Influence of Jackson Dome on Sedimentary Facies and Effect on Water-Bearing Properties of Claiborne in Jackson Area, Mississippi: ABSTRACT

This paper summarizes the importance of diastrophic uplift of the Jackson dome, which occurred during pre-Tertiary time and may have continued more or less active in the middle Eocene, and its influence on the sedimentary cycles in the Claiborne. The uplifting together with compaction of underlying sediments in the rim-syncline area affected the thickness, character, and attitude of the formations and established controls on the occurrence and quality of the ground waters. Isopachous maps and stratigraphic sections are presented to show the thicknesses of the Sparta sand and Cockfield formation on and around the dome; they indicate facies and thickness distribution of the sediments in these and several other units, and the size of the structure. Local concentration of lignitic material in the aquifers causes various degrees of straw-colored water affecting its usefulness for certain specific purposes. The pertinent stratigraphic units and the two principal aquifers are described. End_of_Article - Last_Page 2516------------
Debt, deficits and the dollar

Abstract This paper examines the relationship between the budget deficit and the trade deficit in the United States by presenting new evidence on the impact effects of debt disturbances on the exchange rate. Based upon estimates of a general two-country portfolio-balance model, we find evidence that increases in the U.S. debt stock have caused an appreciation in the U.S. dollar relative to the German mark and the Canadian dollar over the period 1973II–1987II. Correspondingly, this paper presents evidence on the linkage between the budget deficit and the trade deficit arising through the exchange rate.
Synthesis, structure, and reactivity of AlMe2(1-Me-CB11F11): An AlMe2+ cation-like species bonded to a superweak anion

Abstract Treatment of AlMe 3 with [CPh 3 ][1-Me-CB 11 F 11 ] in toluene produced the dimeric compound [AlMe 2 (1-Me-CB 11 F 11 )] 2 in 89% isolated yield. The compound was characterized by 1 H and 19 F NMR spectroscopy and by single crystal X-ray diffraction. The structure consists of a AlMe 2 + cation-like species bonded to two F atoms from two 1-Me-CB 11 F 11 − superweak anions, forming an AlMe 2 F 2 coordination unit with the unusually large H 3 C–Al–CH 3 angle of 147.6(2)° (cf. the corresponding angle of 117.1(1)° in the AlMe 2 F 2 − anion in [N( n -Bu) 4 ][AlMe 2 F 2 ]). This large angle is due in part to the long Al–F distances of 1.922(3) and 1.928(3) A (cf. 1.711(1) and 1.7113(1) A in [N( n -Bu) 4 ][AlMe 2 F 2 ]), which is why the dimethylaluminum moieties in [AlMe 2 (1-Me-CB 11 F 11 )] 2 should possess a considerable degree of positive charge and should be considered as cation-like AlMe 2 + species.
The Distribution of Generalized Sum-of-Digits Functions in Residue Classes

Let Q={Qj}∞j=0 be a strictly increasing sequence of integers with Q0=1 and such that each Qj is a divisor of Qj+1. The sequence Q is a numeration system in the sense that every positive integer n has a unique “base-Q” representation of the form n=∑j⩾0 aj(n) Qj with “digits” aj(n) satisfying 0⩽aj(n)<Qj+1/Qj. A Q-additive function is a function f: N→C of the form f(n)=∑j⩾0 fj(aj(n)) where n=∑j⩾0 aj(n) Qj is the base-Q representation of n and the component functions fj are defined on {0, 1, …, Qj+1/Qj−1} and satisfy fj(0)=0. We study the distribution of integer-valued Q-additive functions in residue classes. Our main result gives necessary and sufficient conditions for f to be uniformly (resp. non-uniformly) distributed modulo m, for any given prime m. We apply this result to many cases, showing, for example, that the sum-of-digits functions associated with base-Q representations are uniformly distributed modulo any prime m.
The coupled turbulent transports of salt and and heat across a sharp density interface

Abstract When a layer of cold fresh water is resting on top of hot salty water with a sharp interface between them, the system as a whole may be unstable, even though the differences of density βΔS due to salinity are far greater than those due to temperature αΔT. Convective motions are produced in both layers by the transfer of heat, and at the same time salt is transported across the interface. Measurements are presented here of the rates of transport in such a two-layer system in which the temperature difference is maintained by heating continuously from below. Both the heat transfer and the ratio of the rates of turbulent transport of salt and heat have been found to depend systematically on the density ratio βΔS αΔT , at least over the small range of heat fluxes used in these experiments. This is in agreement with the result of a simple dimensional analysis, and suggests that the form of the functions should have a wider application. The measurements also indicate that over a wide range of density differences the potential energy change of the top layer due to the lifting of salt is a constant fraction of that released by the transfer of heat.
Limitations of family cancer history assessment at initial surgical consultation.

PURPOSE: Although important for the diagnosis of familial clustering of colorectal cancer and hereditary nonpolyposis colorectal cancer, the accuracy of familial cancer history assessment in the office setting has been questioned. Furthermore, there are few publications describing the optimal method for accurately capturing a family cancer history. The purpose of this study was to determine how well family cancer history is assessed in patients with early age-of-onset colorectal cancer at initial surgical consultation compared with a telephone interview and mailed questionnaire. METHODS: Medical records of patients 40 years old or younger at the time of colorectal cancer surgery were reviewed for documentation of family cancer history at initial surgical consultation. In addition, family cancer history was solicited from surviving patients or their next of kin by telephone and a mailed questionnaire. The kappa coefficient was used to measure degree of correlation between family cancer history obtained at initial surgical consultation and subsequent telephone interview and questionnaire. RESULTS: One hundred twenty-five patients were available for analysis. Family cancer history was documented on the initial surgical consultation report in 78 percent of cases. Although 31.2 percent were identified as having no family cancer history at initial surgical consultation, this proportion decreased to 13.5 percent after telephone interviews and questionnaires. Family history assessment at initial surgical consultation also failed to identify 7 of 11 individuals meeting Amsterdam criteria for hereditary nonpolyposis colorectal cancer and 10 of 16 individuals meeting modified clinical criteria for hereditary nonpolyposis colorectal cancer. CONCLUSIONS: Although family cancer history was commonly obtained during the initial surgical consultation of patients with colorectal cancer, there was a tendency to underestimate the extent of familial cancer. A telephone interview and questionnaire conducted at a later date may reveal a more comprehensive family cancer history. This is an important observation, because individuals identified as high-risk for hereditary nonpolyposis colorectal cancer or familial clustering of colorectal cancer require special consideration with respect to screening, surveillance, and surgical management.
Removal of Heavy Metal and Halide Contamination from Macronutrient Salts.

In micronutrient deficiency experiments with plants the salts used to supply macronutrients must obviously be free of significant contamination. Hewitt (4), in reviewing the testing and purification of nutrient reagents, clearly pointed out that there is no guarantee that even the purest salts commercially available are sufficiently free of the known micronutrients, and that routine use of an appropriate purification procedure is amply justified by many examples of improvement gained in deficiency technique. Routine purification is further justified if it can be done more easily than analytical testing of reagents in search of the occasional highly pure batch. While recrystallization has been extensively used as a general purification procedure, Hughes (5) and Iewitt (4) have pointed out that more effective processes for specific groups of micronutrients are needed. This view is supported by data on the effectiveness of recrystallization which we have included in this report. We have applied a number of procedures with the aim of removing specific micronutrients. For example, micronutrient metals have been removed by adsorption on calcium phosphate (1), by coprecipitating with CuS and FeS (2, 4, 11) and by extracting with 8-quinolinol (4, 9), while chloride has been removed by adding AgNO3 as well as by recrystallizing (2). Some of these processes have not been highly effective, and all are somewhat time-consuming. Accordingly we have developed two new proceduresevaporative treatment with HNO3 to remove halides, and coprecipitation with Mg(OH)2 to remove heavy metal cations. Both are exceedingly simple as well as effective.
Comparison of the efficiency of second-trimester nasal bone hypoplasia and increased nuchal fold in Down syndrome screening

Objective The purpose of this study was to compare the efficiency of second-trimester nasal bone hypoplasia (NB) and increased nuchal fold (NF) in Down syndrome screening. Study Design This was a prospective multicenter cohort study of women who underwent an anatomic survey between 16 and 22 weeks of gestation. The fetal NB and other markers of fetal aneuploidy that included NF were evaluated. NB was defined either as an absent NB or length of 5 mm and >6 mm) were evaluated. Fetuses or infants with Down syndrome were compared with those fetuses without for the presence of NB and increased NF. Results Among 4373 pregnancies that were evaluated over a 5-year period, there were 50 pregnancies with Down syndrome. NB evaluation was obtained in 3936 of 4373 pregnancies (90%); NF was evaluated in all of the fetuses. Absent NB was seen in 14/49 cases (29%), and NF of >6 mm was seen in 6 of 50 cases (12%) with Down syndrome. Conclusion Nasal bone and nuchal fold are efficient markers for Down syndrome. Absent nasal bone was a better predictor of Down syndrome, compared with nuchal fold, and should be a standard marker when a second-trimester genetic sonogram is performed.
Wafer Level Chip Scale Package copper pillar probing

This paper introduces a probing methodology for Integrated Fan Out Wafer Level Chip Scale Packaging (InFO WLCSP) which has the promise of being a very cost effective solution to achieve “More than Moore's law” for mobile devices - more so than 3D integrated circuits (3DIC). InFO WLCSP can use either Aluminum (Al) pads or Copper (Cu) pillars as contact interfaces. Cu pillars without solder caps are selected as the contact interface due to their superior area and cost efficiency. However, there are some challenges due to Cu oxidation and its small size. In this paper we propose a novel methodology that leads to a very high precision test resulting in better yield for mass production of InFO WLCSP packages. We will show results on some industrial designs to validate our claims.
Evidence for a common evolutionary origin of light-harvesting fucoxanthin chlorophyll A/C-protein complexes of Pavlova gyrans (Prymnesiophyceae) and Phaeodactylum tricornutum (Bacillariophyceae)

A fucoxanthin-chlorophyll a/c-protein complex has been isolated from the prymnesiophyte Pavlova gyrans. Thylakoid membranes were treated with the mild anionic detergent sodium taurodeoxycholate followed by sucrose density gradient centrifugation. The brown fraction produced by this procedure was treated with Triton X-100 followed by a second sucrose density gradient centrifugation. A brown fraction isolated from this gradient was shown to be a light-harvesting complex nearly identical to that which is present in the diatom Phaeodactylum tricornutum. The complexes from the two organisms have nearly identical absorption and flourescence spectra, both complexes contain fucoxanthin and two other carotenoids, both contain four polypeptides of similar molecular weights, and polypeptides from both complexes cross react with antibodies raised to polypeptides of the Phaeodactylum tricornutum complex. Results suggest a common evolutionary origin for these light-harvesting complexes, in apparent contrast to the great differences in cell structure between prymnesiophytes and diatoms.
A New HF-Link Parameters/Quality Analysis Approach

HF communication systems operations are characterized by several well-known problems, most of which can be overcome by advances in communications and processing technology. Success is strongly dependent upon selection of the optimum operating frequency and data-transmission configuration, which are highly time and link variable. Described in this paper is a new approach for "real-time" HF-link parameters measurement and quality analysis (LQA) applicable to optimization of high-speed HF data links. The approach employs a digital-signal-processing-based technique for measurement of general HF channel parameters, using simple, in-band test signals, and algorithmic estimation of data-transmission performance for a variety of link configurations. Channel-parameters measurement accuracies are illustrated. Also shown are results of on-the-air HF transmission tests in which LQA-based estimated BER's are correlated with measured BER's for modems operating over temperate-latitude and transauroral paths. Planned implementations in adaptive systems are described.
Optical and electrical properties of self-assembled, ordered gold nanocrystal/silica thin films prepared by sol–gel processing

Highly ordered gold nanocrystal (NC)/silica films are synthesized by self-assembly of water-soluble gold NC micelles and silica using a sol-gel spin coating technique. The optical properties are analyzed using ellipsometry and ultraviolet-visible spectroscopy. Transmission and absorption spectra were measured for wavelengths ranging from 200 to 2000 nm. The absorption spectra show a strong surface plasmon absorption band at {approx}520 nm for all samples. Charge transport behavior of the films was examined using metal-oxide-semiconductor (MOS) and metal-insulator-metal (MIM) structures. MOS capacitor samples exhibit charge storage with discharge behavior dominated by electron transport within the gold NC arrays. Low temperature current-voltage measurements on MIM devices reveal electrical conduction with a thermal activation energy of {approx}90 meV. For temperatures less than 100 K, the I-V characteristics of the NC film exhibits a strong coulomb blockade effect, with a threshold voltage of {approx}0.5 V measured at 78 K.
SOME RECENT DEVELOPMENTS IN FINITE-STRAIN ELASTOPLASTICITY USING THE FIELD-BOUNDARY ELEMENT METHOD

A new boundary integral equation is derived directly for velocity gradients in a finite strain elasto-plastic solid. These integral equations for velocity gradients do not involve hyper-singularities (when the source point is taken to the boundary) of the type found in the alternate case when the integral equations for velocities are differentiated to derive an integral relation for velocity gradients. Hence the new formulation obviates the need for a two tier system of computing the velocity gradients, which existed in the alternate case. A generalized mid-point radial return algorithm is presented for determining the objective increments of stress from the computed velocity gradients. Moreover, a mid-point evaluation of the generalized Jaumann integral is used to determine the material increments of stress. The constitutive equation employed is based on an endochronic model of combined isotropic/kinematic hardening finite plasticity using the concepts of a material director triad and the associated plastic spin.
Dietary taurine manipulations in aged male Fischer 344 rat tissue: taurine concentration, taurine biosynthesis, and oxidative markers

Taurine (TAU) is a ubiquitous sulfur-containing amino acid that has been proposed to be an antioxidant. The concentration of TAU decreases during aging, which may increase susceptibility to oxidative stress. Our study attempted to elucidate the mechanism for the age-dependent decrease in TAU content by examining TAU biosynthesis in aged rats. We also examined the effects of dietary TAU manipulations on TAU content and oxidative markers in aged male Fischer 344 (F344) rats. Adult (9 months) and aged (26 months) rats fed control diets, aged rats fed control diet and TAU-supplemented (1.5%) water, and aged rats fed a TAU-deficient diet were used. We observed a significant age-related decrease in TAU content in liver, kidney, and cerebellum. Dietary TAU supplementation increased tissue TAU content, whereas dietary TAU restriction had no effect. Enzyme-dependent TAU synthesis showed an age-dependent reduction in liver that was decreased further by TAU supplementation. Protein carbonyl content was elevated in the cerebral cortex and kidney of aged rats and was attenuated by TAU supplementation. A trend for a decrease in protein and acid-soluble thiol contents in hepatic tissue of aged rats was observed, and this was attenuated with dietary TAU supplementation. Our data show that a decrease in hepatic TAU biosynthesis may cause, in part, the observed decline in tissue TAU content in aged F344 rats, and TAU supplementation can restore TAU levels. Our study indicates that a decline in TAU content may exacerbate oxidative stress in aged rats, which can be reversed by dietary TAU supplementation.
Determination of Oxygenates in Gasoline by GC×GC

Comprehensive two-dimensional gas chromatography (GC × GC) has been applied to the quantitation of oxygenates in reformulated gasoline. Target oxygenates were C 1 -C 4 alcohols, tert-pentanol, methyl tert-butyl ether (MTBE), diisopropyl ether (DIPE), ethyl tert-butyl ether (ETBE), and tert-amyl methyl ether (TAME). These were separated from the gasoline matrix using a volatility-based selectivity in the first chromatographic dimension, followed by a mixed-phase polarity/shape selectivity in the second dimension. The high resolving power of this stationary phase combination completely separated all oxygenates except DIPE, ETBE, and TAME, which exhibited coelution with other nonpolar gasoline components. Oxygenates quantitation was achieved with the use of an internal standard, an FID detector, and calibration curves. Quantitation results are in good agreement with ASTM and EPA standard methods. When coupled with our previous method for BTEX and aromatics, a single GC × GC method can now quantitate MTBE, alcohols, BTEX, and aromatics in a one-hour analysis.
Electrical characterization of heavily doped polycrystalline silicon for high-frequency bipolar transistor application

Electrical conduction data from heavily doped p-type polysilicon thin films at room temperature and above are presented. Specifically, the sheet resistance, in the range from 1 kΩ/□ to 100 Ω/□ for a doping level of 1019cm-3to 1020cm-3, is characterized over temperatures from 300 to 450 K. It is shown that the polysilicon resistivity, larger than the corresponding crystalline value by a factor ∼ 10, is flat over the entire temperature range used for measurement. This large resistivity is correlated to the degree of dopant activation and the mobility in polysiUcon. The measured mobility varying from 8 to 20 cm2/V . s is shown to be smaller than the crystalline mobility at the same doping level by a factor 7 ∼ 3. These data are comprehensively discussed and quantified, based on a distributed resistivity model.
Environmental Significance of Certain Yellow-Brown Dolomites, Great Basin, California and Nevada: ABSTRACT

Within the dominantly gray limestone and dolomite sequences of the Great Basin, sporadic yellow-brown dolomite is present as discrete beds, lentils, or wisps--the latter imparting a mottled or pseudobrecciated appearance. These distinct deposits, studied in Ordovician, Devonian, Pennsylvanian, and Triassic formations, are fine grained, are usually unfossiliferous, and posses a less than 5 percent terrigenous fraction of well-rounded quartz and sparse feldspar. Laminations, desiccation polygons, and possible relict bird's-eye structures also are apparent. Stratigraphically, these deposits commonly overlie dolomite sequences several hundreds of feet thick and are in turn overlain by limestone sequences of varied thicknesses. The persistent occurrence of these yellow-brown dolomites at the top of dolomitized sequences possibly indicates that the yellow-brown lithology represents supratidal or penecontemporaneous dolomitization from which seepage-refluxion brines ultimately descend. The underlying rocks commonly are coarser grained, contain normal marine fossils, and reveal gravity-controlled dolomitization structures. In some cases where yellow-brown deposits are incorporated in a completely dolomitized interval, the beds below the lowest yellow-brown horizon reveal multiple dolomitization. End_of_Article - Last_Page 770------------
The mediating role of positive relations with others in associations between depressive symptoms, social skills, and perceived stress

Abstract This study was designed to examine the role of positive relations with others as a mediator of the association between poor social skills and depression and between depression and increased perceptions of stress. To test these two models, data were collected from 179 young adults assessed three times over the course of 4 months. Sobel’s product of coefficients test and lower-level mediation modeling were used to evaluate these predictions. The results showed that positive relations with others completely mediated the negative association between social skills and depression. Social skills also moderated the positive association between depression and perceptions of stress. These findings illustrate how positive relations with others function to promote psychological well-being.
Observation of a high-density ion mode in tokamak microturbulence.

For high-density Ohmic discharges in the TEXT (Texas Experimental) tokamak, a distinct ion mode (i.e., density fluctuations propagating in the ion diamagnetic drift direction) is observed in the microturbulence spectra. The magnitude and spectral characteristics of this mode are identified. Onset of the ion feature occurs at plasma densities where a clear saturation is evident in the global energy-confinement time ${\ensuremath{\tau}}_{E}$. A possible connection between this experimentally observed ion mode and the theoretically predicted properties of instabilities driven by ion temperature gradient (${\ensuremath{\eta}}_{i}$) is explored.
James Monroe and John Adams: An Unlikely "Friendship"

(2005). James Monroe and John Adams: An Unlikely“Friendship”. The Historian: Vol. 67, No. 3, pp. 405-433.
Threading a peptide through a peptide: Protein loops, rotaxanes, and knots

Proteins adopt complex folds in nature that typically avoid conformations that are knotted or "threaded" through closed loops. Is this the result of fundamental barriers to folding, or have proteins simply evolved to avoid threaded conformations? Organic synthesis has been used in supramolecular chemistry to install topological links in small molecules. By following these principles, we now show that it is possible to assemble a topologically linked protein complex by threading a linear protein through a cyclic protein to form a [2]pseudo-rotaxane. Subsequent ring closure using native chemical ligation cyclizes the linear protein, forming a [2]heterocatenane. Although the kinetics of protein threading are slower than the folding kinetics of the native protein, threading appears to be a highly efficient process.
Influence of alkalis on porosity percolation in hydrating cement pastes

Loss-on-ignition (LOI) measurements and low temperature calorimetry (LTC) are used to study the properties of hydrating cement pastes with various quantities of alkalis. In addition to the well-known acceleration of early age hydration and ‘‘retardation’’ of later age hydration, the alkalis are observed to have a significant effect on the percolation of the porosity in the hydrating systems, as assessed using the LTC technique. At equivalent degrees of hydration, the capillary pores in cement pastes with sufficient added alkalis may depercolate while those in lower alkali cement pastes remain percolated. A simple dissolution/precipitation three-dimensional microstructural model is applied to examine the potential effects of hydration product morphology (random, needles, and plates or laths) on pore space percolation. The model suggests that the observed experimental results could be consistent with the higher alkali levels modifying the morphology of the C–S–H gel to produce more lath-like hydration products, as has been observed by others previously using electron microscopy. Potential implications for the transport properties and durability of these materials are discussed. 2006 Elsevier Ltd. All rights reserved.
Controlled Fabrication of Colloidal Semiconductor-Metal Hybrid Heterostructures: Site Selective Metal Photo Deposition

Reliable synthesis of semiconductor–metal heterostructures would increase their availability for fundamental studies and applications in catalytic, magnetic, and opto-electronic devices. Here, we demonstrate there are three main pathways for the formation of Pt and Pd nanoparticles on CdS and CdS0.4Se0.6 nanorods. A thermal pathway and photochemical pathway occur when the metal precursor is heated or irradiated directly in the presence of an electron donor, leading to homogeneous nucleation and formation of freestanding metal nanoparticles. A separate photochemical pathway occurs in the presence of semiconductor nanorods, leading to exciton formation and quenching by electron trapping at surface defect sites. The localized electrons act as seeding points, leading to heterogeneous nucleation and formation of surface-bound metal nanoparticles. Careful selection of synthetic conditions allows deposition of Pt and Pd particles on CdS and CdS0.4Se0.6 nanorods with a high degree of selectivity (90–95% surface-b...