cssi/SciSciGPT-SciSciNet huggingface dataset:
Evaluation of radioactive background rejection in 76Ge neutrino-less double-beta decay experiments using a highly segmented HPGe detector

Abstract A highly segmented coaxial HPGe detector was operated in a low background counting facility for over 1 year to experimentally evaluate possible segmentation strategies for the proposed Majorana neutrino-less double-beta decay experiment. Segmentation schemes were evaluated on their ability to reject multi-segment events while retaining single-segment events. To quantify a segmentation scheme's acceptance efficiency the percentage of peak area due to single segment events was calculated for peaks located in the energy region 911–2614 keV. Single interaction site events were represented by the double-escape peak from the 2614 keV decay in 208 Tl located at 1592 keV. In spite of its prototypical nature, the detector performed well under realistic operating conditions and required only minimal human interaction. Though the energy resolution for events with interactions in multiple segments was impacted by inter-segment cross-talk, the implementation of a cross-talk correlation matrix restored acceptable resolution. Additionally, simulations utilizing the MaGe simulation package were performed and found to be in good agreement with experimental observations verifying the external nature of the background radiation.
Assessment of EGFR Mutation Status in Lung Adenocarcinoma by Immunohistochemistry Using Antibodies Specific to the Two Major Forms of Mutant EGFR

EGFR mutations are the best predictors of response to EGFR kinase inhibitors in lung adenocarcinoma. We evaluated two mutation-specific monoclonal antibodies for the detection of EGFR mutations by immunohistochemistry (IHC), generated respectively against the L858R mutant and the exon 19 mutant with the common 15bp/5AA deletion. These two mutations account for approximately 90% of all EGFR mutations. IHC staining performed on 218 paraffin-embedded lung adenocarcinomas was assessed on a 0 to 3+ scale, and positivity cutoffs of 1+ and 2+ were compared. All cases were studied by standard molecular methods for these two mutations, and selected cases were also studied using higher sensitivity molecular assays. The EGFR L858R mutant antibody showed a sensitivity of 95% and a positive predictive value (PPV) of 99% with a positivity cutoff of 1+ and a sensitivity of 76% and a PPV of 100% with a positivity cutoff of 2+. The EGFR exon 19 mutant–specific antibody showed reduced sensitivity for exon 19 deletions other than 15bp. A positivity cutoff of 1+ resulted in a sensitivity of 85% and a PPV of 99%, whereas a 2+ cutoff gave a sensitivity of 67% and a PPV of 100%. IHC with EGFR mutant–specific antibodies could be used as a screen to identify most candidates for EGFR inhibitors.
Solvothermal synthesis and mechanical characterization of single crystalline copper nanorings

Single crystalline copper nanorings were synthesized through the solvothermal process. The N-methyl-2-pyrrolidone (NMP)/water system is thought to be the key factor to form the novel structure, and a growth-stress induced bending mechanism is proposed to explain the formation mechanism. Micro-manipulation experiments revealed excellent mechanical properties of these copper nanorings.
The Comparative Safety of Intravenous Iron Dextran, Iron Saccharate, and Sodium Ferric Gluconate

Intravenous iron treatment is an important component of anemia therapy for patients on dialysis. Until recently iron dextran was the only parenteral form of iron available in the United States. This drug has been associated with occasional serious adverse reactions, including full-blown anaphylaxis. In 1999 the Food and Drug Administration approved a second form of iron for intravenous administration, sodium ferric gluconate in sucrose. It is expected that by the time of this publication, a third agent, iron saccharate will also be approved. In this review the comparative safety of these three agents is critically evaluated.
Evaluation of five commercial broiler crosses. 1. Grow-out performance

Abstract A total of 21,000 broilers was used in four experiments (one experiment per season) to evaluate the grow-out performance and carcass quality of five commercially available broiler crosses. The crosses were Hubbard × Hubbard, Hubbard × H&N, Hubbard × Shaver, Ross × Hubbard and Ross × Arbor Acre. Each experiment consisted of three replicate pens (175 birds/pen) per sex per cross. Egg weight differences for the combined experiments were nonsignificant. However, a summary of the four experiments revealed significant broiler cross differences in both day-old male and female chick weights. Both Hubbard × Shaver and Ross × Arbor Acre crosses had lower percentages of saleable chicks. At 28 days of age, male progeny differed statistically in both body weight and feed conversion. At 56 days, Hubbard × Hubbard and Ross × Hubbard females were significantly heavier than other crosses. Numerically, the combined sexes weighed 2063, 2053, 2019, 2013, and 2003 g for Hubbard × Hubbard, Ross × Hubbard, Hubbard × Shaver, Hubbard × H&N, and Ross × Arbor Acre, respectively. Male and combined sex feed utilization differed statistically at this age. No significant broiler cross differences were found in 28 or 56 day mortality or disease condemnations. Carcass quality, as determined by causes of downgrading, revealed Ross sired male progeny had fewer downgrades due to conformation, breast blisters and breast bruises than did Hubbard paternal crosses. In females, statistical paternal cross differences were found only in conformation downgrades. No significant differences were recorded in fleshing, leg bruises and broken or dislocated bones downgrades.
Gas molecule scattering & ion mobility measurements for organic macro-ions in He versus N2 environments

A pending issue in linking ion mobility measurements to ion structures is that the collisional cross section (CCS, the measured structural parameter in ion mobility spectrometry) of an ion is strongly dependent upon the manner in which gas molecules effectively impinge on and are reemitted from ion surfaces (when modeling ions as fixed structures). To directly examine the gas molecule impingement and reemission processes and their influence, we measured the CCSs of positively charged ions of room temperature ionic liquids 1-ethyl-3-methylimidazolium dicyanamide (EMIM-N(CN)2) and 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIM-BF4) in N2 using a differential mobility analyzer-mass spectrometer (DMA-MS) and in He using a drift tube mobility spectrometer-mass spectrometer (DT-MS). Cluster ions, generated via electrosprays, took the form (AB)N(A)z, spanning up to z = 20 and with masses greater than 100 kDa. As confirmed by molecular dynamics simulations, at the measurement temperature (∼300 K), such cluster ions took on globular conformations in the gas phase. Based upon their attained charge levels, in neither He nor N2 did the ion-induced dipole potential significantly influence gas molecule–ion collisions. Therefore, differences in the CCSs measured for ions in the two different gases could be primarily attributed to differences in gas molecule behavior upon collision with ions. Overwhelmingly, by comparison of predicted CCSs with selected input impingement–reemission laws to measurements, we find that in N2, gas molecules collide with ions diffusely – they are reemitted at random angles relative to the gas molecule incoming angle – and inelastically. Meanwhile, in He, gas molecules collide specularly and elastically and are emitted from ion surfaces at determined angles. The results can be rationalized on the basis of the momentum transferred per collision; in the case of He, individual gas molecule collisions minimally perturb the atoms within a cluster ion (internal motion), while in the case of N2, individual gas molecules have sufficiently large momentum to alter the internal motion in organic ions.
A semi-rational nucleate boiling heat flux correlation

Abstract Tien's model for nucleate boiling heat transfer is re-examined in the light of a recent experiment by Benjamin and Westwater. The study leads to a semi-rational modification of his prediction, which gives better correlation of available data.
Appendix C—Ground-water investigations in the southwest

During the past three years the Division of Irrigation, Soil Conservation Service of the United States Department of Agriculture, has been conducting drainage studies of irrigated lands in Imperial Valley, California, in cooperation with the Imperial Irrigation District and other agencies. Ground-water fluctuations in observation-wells and flow of water from tile drains were measured in problem areas. In 1943–44 the permeability of representative subsoils was measured by field and laboratory methods for the purpose of obtaining data for determining proper spacing and depth of subsurface drains. The Division, in connection with irrigation and consumptive use of water-studies, continued measurement of ground-water fluctuations in the San Luis Rey Valley, San Diego County, in cooperation with the California State Division of Water Resources and the United States Geological Survey. Early in 1944 investigations on evapotranspiration losses and ground-water fluctuations along the Santa Ana River for several miles below Prado Dam were started in cooperation with the United States Geological Survey and the Orange County Water District for the purpose of determining the quantity of water that might be conserved for irrigation.
Composite risk factors predict survival after transplantation for congenital heart disease.

Objective(s) Previous studies have shown that individual risk factors are poor predictors of mortality after heart transplantation in patients with congenital heart disease. We developed composite risk factor groups to better predict mortality after cardiac transplantation. Methods We conducted a cross-sectional retrospective analysis of all heart transplants performed for congenital heart disease at a single congenital heart transplant center between 1996 and 2011. Patient, procedural, and hospital course data were obtained through a review of medical records. Univariate analyses were performed using the Fisher exact test for categorical data and the Mann-Whitney U test for continuous variables. Overall mortality was examined using Kaplan-Meier estimates for univariate analysis and Cox regression analysis for multivariate analysis. A comparison of patients with functional single ventricles (SVs) versus biventricular (BV) hearts was performed. Mean follow-up duration for the whole group was 51 ± 43 months (median, 43 months). Results Forty-six patients underwent heart transplantation during the study period. Mean age at transplant was 9.0 ± 9.1 years; 45% (n = 21) were in the SV group and 55% (n = 25) were in the BV group. The SV group had significantly more previous sternotomies ( P = .006) and longer bypass times (266 ± 78 vs 207 ± 64 minutes; P = .001). High panel-reactive antibody levels (>10%) were also more common in the SV group (38% vs 13%; P = .08). Overall hospital mortality was 4.3% (n = 2, both SVs). There was no significant difference in operative mortality (10% SV vs 0% BV; P = .20) or major morbidity (33% SV vs 44% BV; P = .51) between the 2 groups. High-risk groups identified by univariate analysis were patients with an SV diagnosis + dialysis ( P P = .026), or VAD/ECMO + renal insufficiency ( P = .006)/VAD/ECMO + dialysis ( P P = .016). By multivariate analysis, preoperative renal insufficiency ( P = .038) and the composite SV + dialysis ( P = .005) were predictors of overall mortality. Although survival at 2 years was lower in the SV cohort (73% vs 96%; P = .16), this benefit was not apparent (63% vs 69%) at late follow-up. Conclusions Preoperative renal insufficiency and SV + dialysis are strong predictors of overall mortality and identify high-risk congenital heart transplant recipients. Although individual risk factors may not predict survival, a composite of factors may be more useful in identifying the high-risk recipient.
Silicon's usefulness in photovoltaics

Today, more than ever, photovoltaic energy seems to be on its way to becoming a leading source of electrical power. Prices are dropping and photovoltaic power systems are improving in quality, reliability, and capacity to convert sunlight directly into electricity. One large purchaser of photovoltaics are electric utilities. Here, the author examines the prospects of PV power generation and outlines the economic, as well as environmental, benefits of using this technology. >
Classifying relative equilibria. II

We announce several theorems on the evolution of relative equilibria classes in the planar n-body problem. In an earlier paper [1] we announced a partial classification of relative equilibria of four equal masses. In [2] we described these new relative equilibria classes and showed the way in which a degeneracy arose in the four body problem. These results point the way toward classifying relative equilibria for any n > 4.
Respiratory muscle weakness in peripheral neuropathies

Common peripheral neuropathies do not usually cause diaphragmatic weakness and subsequent respiratory compromise. However, respiratory involvement is relatively common in Guillain-Barre syndrome (GBS). Experience in GBS has led to a standardized approach to manage respiratory problems in peripheral neuropathies. Diaphragmatic weakness is not common in chronic inflammatory demyelinating polyneuropathy and extremely rare in multifocal motor neuropathy. The linkage has been described between certain subtypes of Charcot-Marie-Tooth (CMT) disease such as CMT2C and CMT4B1 and diaphragmatic weakness. A correlation usually has not been found between electrophysiologic findings and clinical respiratory signs or spirometric abnormalities in peripheral neuropathies except in amplitudes of evoked phrenic nerve responses. Careful and frequent assessment of respiratory function by a qualified team of healthcare professionals and physicians is essential. Criteria established for mechanical ventilation in GBS cases may be applied to other peripheral neuropathies with respiratory compromise as necessary.
Terahertz space-charge interactions in a semiconductor nanoplate

To properly account for space-charge effects, transport models can be employed in the analysis of charge motions within semiconductor nanostructures. In this paper, we present the analysis and computations of internal charge and field distributions in a semiconductor nanoplate. Analytical and numerical simulation results reveal space-charge waves excited in the plate as the bulk plasma frequency is approached, which is in the terahertz band. A lumped equivalent circuit is developed to characterize the dispersion properties and to facilitate the consideration of more complex structures based on aggregates of nanoplates for potential circuit and waveguide applications in the terahertz frequency range.
VOLUNTARY TURNOVER RELATED TO INFORMATION TECHNOLOGY PROFESSIONALS: A REVIEW OF RATIONAL AND INSTINCTUAL MODELS

Traditionally, models of voluntary turnover assume that a rational actor follows a series of linear steps leading towards turnover. In regards to the construct of voluntary turnover, information technology professionals represent a unique phenomenon that may not adhere to traditional models. A new instinctual model of voluntary turnover provides an alternative method of understanding the processes involved when information technology professionals contemplate turnover.
The influence of oxygen tension on the induction of nitric oxide and prostaglandin E2 by mechanical stress in articular cartilage

Summary Objectives Articular cartilage is an avascular tissue that exists at low oxygen tension. Oxygen tension can influence the production of the pro-inflammatory mediators nitric oxide (NO) and prostaglandin E2 (PGE 2 ) in cartilage, which are increased in osteoarthritis (OA). The synthesis of these molecules can be stimulated by mechanical stress, which is an important risk factor for OA. The objective of this study was to determine the influence of oxygen tension on the induction of NO and PGE 2 production in articular cartilage in response to mechanical stress. Design Intermittent mechanical compression (0.05MPa, 0.5Hz for 24h) was applied to full thickness skeletally mature porcine articular cartilage explants at either 20%, 5%, or 1% O 2 . NO, PGE 2 and peroxynitrite formation were measured, and the effect of the selective nitric oxide synthase 2 inhibitor 1400W was tested. Results Incubating articular cartilage at 5% O 2 significantly increased ( P 2 . Peroxynitrite formation was lower at reduced oxygen tension. Mechanical compression significantly increased ( P 2 but not at 5% or 1% O 2 , and significantly increased ( P 2 production at 20% O 2 (50 fold) and 5% O 2 (4 fold) but not at 1% O 2 . 1400W blocked mechanically induced NO production and further increased PGE 2 production at 5% O 2 ( P Conclusions Oxygen tension influences the endogenous production of NO and PGE 2 in cartilage and can have a significant effect on the induction of these inflammatory mediators in response to mechanical compression.
Vascular endothelial growth factor enhances migration of astroglial cells in subventricular zone neurosphere cultures

Vascular endothelial growth factor (VEGF) is an endothelial and neuronal survival factor and a mitogen for endothelial cells and astrocytes in both explant and in vivo injury models. In the CNS, interplay between the vasculature and neural stem progenitor (NSP) cells is required for the maintenance of angiogenic/neurogenic coordination in the germinal niche in the subventricular zone (SVZ) of the lateral ventricle. Using an in vitro SVZ neurosphere (NS) model, this study aimed to understand the direct effects of VEGF and its receptor signaling on neonatal NSP cell growth and migration. Our data indicate that VEGF administration, compared with untreated or brain-derived neurotrophic factor-treated NS, significantly increased growth and migratory capacity of glial fibrillary acidic protein (GFAP)+ and nestin+ NSP cells and in secondary cultures induced a stellate astrocyte morphology. Blockade of both VEGF, which is normally expressed in some NS cells, and its flt-1 receptor signaling by neutralizing antibodies caused morphological changes specifically in GFAP+ cells and disrupted sphere formation and outward migration. These cells did not appear as conventional polygonal astrocytes; their process growth was severely restricted, and overall migration was reduced by up to 76% of control cultures. Blockade of VEGF's flk-1 receptor reduced VEGF expression and caused a lesser, though significant, decrease (29%) in NSP (GFAP+) cell migration. The results show that both VEGF and, in particular, flt-1 receptor signaling are critical to the proper configuration of the NS and its subsequent development. VEGF is also an important growth and migratory factor particularly for GFAP+ cells developing in SVZ-derived NS in culture. © 2009 Wiley-Liss, Inc.
EARLY STAGES OF METAL-Si (Ge) COUMPOUND FORMATION : A FIM STUDY OF INTERFACIAL ATOMIC STRUCTURES

Early stages of metal-Si (Ge) compounds growth and the interface atomic structures have been studied with FIM. Single crystal NiSi2 and CoSi2 films can be grown on the [111] oriented Si tip in UHV. From the axial symmetry change, either identical or 180° change, the interfaces are identified to be either A-type or B-type. Atomic structures of silicide overlayers grown on either metal or silicon tip surfaces have also been studied. Very well developed silicide overlayer structures have been observed for RhSi (RhGe) grown on Rh(001), or RhSi(RhGe)/Rh(001), and other systems such as IrSi(IrGe)/Ir(001), RhSi/Si(120), PtSi/Si(120) and IrSi/Si(120). In almost every case, two different types of interface, or overlayer, structure have been observed.
Omnidirectional Position Location For Mobile Robots

Autonomous, self-guiding mobile robots require special sensors that are not necessary for stationary robots. The purpose of this paper is to describe the design, construction and initial testing of an omnidirectional vision system used to control a mobile robot. A unique sensor and algorithm have been developed to calculate the distance from the center of the vision system to fixed position targets. The system provides an absolute global positioning system for the mobile robot. The guidance and position determination algorithm are described and some experimental results are given. The sensor has been developed for a prototype mobile robot for lawn mowing. However, the method appears to have several other applications. Some of these include industrial carts for material transport, military sentry duties and mobile tanks, medical patient care transport systems, as well as domestic applications such as vacuum cleaning.
Correlation of Relative Afferent Pupillary Defect and Retinal Nerve Fiber Layer Loss in Unilateral or Asymmetric Demyelinating Optic Neuropathy

PURPOSE To investigate the relationship between relative afferent pupillary defect (RAPD) and retinal nerve fiber layer (RNFL) thickness assessed by optical coherence tomography (OCT) in patients with unilateral or asymmetric demyelinating optic neuropathy. METHODS Seventy-two patients with unilateral or asymmetric demyelinating optic neuropathy were retrospectively evaluated. RAPD was measured by the swinging flashlight method using neutral density filters, and RNFL thickness was measured with the OCT. Relationships between RAPD and RNFL thickness difference/ratio between the two eyes (in superior, inferior, temporal, nasal quadrants and total thickness) were evaluated by linear regression. Coefficients of determination (R(2)) were calculated using a multivariate model. RESULTS The mean RNFL thickness in the more affected eyes was 82.7 +/- 18.7 microm, and in the fellow eyes it was 88.9 +/- 13.97 microm (R(2) = 0.406; P < 0.0001). RAPD size correlated significantly with both RNFL thickness difference (total: R(2) = 0.191, P < 0.0001; superior: R(2) = 0.203, P < 0.0001; inferior: R(2) = 0.126, P = 0.002; temporal: R(2) = 0.059, P = 0.040; nasal: R(2) = 0.062, P = 0.035) and RNFL thickness ratio (total: R(2) = 0.325, P = 0.0001; superior: R(2) = 0.339, P < 0.0001; inferior: R(2) = 0.256, P < 0.0001; temporal: R(2) = 0.151, P = 0.0001; nasal: R(2) = 0.156, P = 0.001). CONCLUSIONS RAPD as measured in log units significantly correlated with total and quadrantic RNFL thickness differences and ratios. Total, superior, and inferior quadrant data produced the strongest correlations.
Methylene as a possible universal footprinting reagent that will include hydrophobic surface areas: overview and feasibility: properties of diazirine as a precursor.

Methylene is one of, if not the, most reactive organic chemical known. It has a very low specificity, which makes it essentially useless for synthesis, but suggests a possible role in protein footprinting with special importance in labeling solvent accessible nonpolar areas, identifying ligand binding sites, and outlining interaction areas on protomers that form homo or hetero oligomers in cellular assemblies. The singlet species is easily and conveniently formed by photolysis of diazirine. The reactions of interest are insertion into C-H bonds and addition to multiple bonds, both forming strong covalent bonds and stable compounds. Reaction with proteins and peptides is reported even in aqueous solutions where the vast majority of the reagent is used up in forming methanol. Species containing up to 5 to 10 extra :CH2 groups are easily detected by electrospray mass spectroscopy. In a mixture of a 14 Kd protein and a noninteracting 1.7 Kd peptide, the distribution of mass peaks in the electrospray spectra was close to that expected from random modification of the estimated solvent accessible area for the two molecules. For analysis at the single residue level, quantitation at labeling levels of one 13CH2 group per 10 to 20 kDa of protein appears to be possible with isotope ratio mass spectroscopy. In the absence of reactive solvents, photolysis of diazirine produces oily polymeric species that contain one or two nitrogen atoms, but not more, and are water soluble.
Geometric constraints within feature hierarchies

We study the problem of enabling general 2D and 3D variational constraint representation to be used in conjunction with a feature hierarchy representation, where some of the features may use procedural or other non-constraint based representations. We trace the challenge to a requirement on constraint decomposition algorithms or decomposition-recombination (DR) planners used by most variational constraint solvers, formalize the feature hierarchy incorporation problem for DR-planners, clarify its relationship to other problems, and provide an efficient algorithmic solution. The new algorithms have been implemented in the general, 2D and 3D opensource geometric constraint solver FRONTIER developed at the University of Florida.
Gene Expression in Uterine Leiomyoma from Tumors Likely to Be Growing (from Black Women over 35) and Tumors Likely to Be Non-Growing (from White Women over 35)

The study of uterine leiomyomata (fibroids) provides a unique opportunity to investigate the physiological and molecular determinants of hormone dependent tumor growth and spontaneous tumor regression. We conducted a longitudinal clinical study of premenopausal women with leiomyoma that showed significantly different growth rates between white and black women depending on their age. Growth rates for leiomyoma were on average much higher from older black women than for older white women, and we now report gene expression pattern differences in tumors from these two groups of study participants. Total RNA from 52 leiomyoma and 8 myometrial samples were analyzed using Affymetrix Gene Chip expression arrays. Gene expression data was first compared between all leiomyoma and normal myometrium and then between leiomyoma from older black women (age 35 or older) and from older white women. Genes that were found significant in pairwise comparisons were further analyzed for canonical pathways, networks and biological functions using the Ingenuity Pathway Analysis (IPA) software. Whereas our comparison of leiomyoma to myometrium produced a very large list of genes highly similar to numerous previous studies, distinct sets of genes and signaling pathways were identified in comparisons of older black and white women whose tumors were likely to be growing and non-growing, respectively. Key among these were genes associated with regulation of apoptosis. To our knowledge, this is the first study to compare two groups of tumors that are likely to have different growth rates in order to reveal molecular signals likely to be influential in tumor growth.
The isolation of 4-methylimidazole from caramel color and its determination by thin-layer and gas-liquid chromatography

Abstract The presence of small quantities of 4-methylimidazole (4-MeI) in caramel color has been confirmed by retention time data, and infrared and mass spectroscopy. This paper describes a method for the quantitative extraction of 4-MeI from caramel color, and two chromatographic procedures—thin-layer (TLC) and gas-liquid (GLC) chromatography—for the quantitative determination of 4-MeI in the extracts. The accuracy and precision of the extraction and the chromatographic procedures were tested by analysis of: (a) model caramel color systems; (b) samples of experimental caramel colors of low 4-MeI content; and (c) duplicate samples of caramel color by two participating laboratories. The extraction procedure permits the quantitative recovery of 4-MeI from samples of caramel color; the TLC and GLC analysis procedures provide approximately equal accuracy, with somewhat greater precision afforded by the GLC procedure. The GLC procedure is therefore recommended when precise determinations of 4-MeI concentrations are required; the TLC procedure is recommended for screening studies where a rough estimation of 4-MeI is sufficient.
A second peak in uptake of gentamicin by rat kidney after cessation of treatment.

Gentamicin was administered s.c. to rats once daily for 7 days at 5 mg kg−1. At the end of this period renal concentrations of gentamicin declined from day 1 to day 5 post-dosing, but showed a second peak on day 8, after which they declined again through days 16 and 22. This second peak coincided with a peak of mitotic activity in the kidney, suggesting that this organ, while recovering from gentamicin-induced damage, passes through a temporary phase during which it has increased affinity for gentamicin.
AN EMPIRICAL TEST OF LORD'S THEORETICAL RESULTS REGARDING FORMULA SCORING OF MULTIPLE-CHOICE TESTS

In a recent article, Lord (1975) demonstrated that the conventional correction-forguessing formula2 is superior to number-right scoring as an estimator of true examinee performance on multiple-choice tests, when examinees respond according to specified rules. The explicit assumption made by Lord is that, when appropriate instructions are provided, the only difference between an answer sheet obtained under formula-scoring directions and the same answer sheet obtained under number-right scoring directions would be that omitted responses (if any) on the former answer sheet are replaced by random guesses on the latter. While this assumption is far more tenable than the usual assumption associated with formula scoring,-that examinees either know the answer and mark it, or guess randomly among all item choices-it does not avoid the possibility that the admonition against wild guessing may cause examinees in general, or examinees with certain personality characteristics, to refrain from providing answers to questions which they have better than a chance probability of marking correctly. This possibility has been suggested by several investigators (Votaw, 1936; Sheriffs and Boomer, 1954; Slakter, 1968b). However, Lord noted that in each of these studies, the reported directions to examinees were inappropriate for an adequate test of his assumption. In addition, he faulted the study by Slakter (1968a) because the examinees had an opportunity to discuss or look up answers to questions omitted under formula-scoring directions. Both of these limitations are avoided in the present study. Another factor that may result in differential compliance with formula-scoring directions is that some examinees may correctly judge that their expected score will not be adequate in a competitive examination, and may therefore choose to answer all or nearly all questions in the hope that luck, in the short run, will be on their side. To the extent that such examinees are present, Lord's assumption would be less tenable. Since there are at least two a priori reasons to suspect that certain students either cannot or will not comply with directions appropriate for formula scoring, this study was designed to test the validity of Lord's assumption in a typical test-taking situation.
Lysates of two established human tumor lines contain heparin-binding growth factors related to bovine acidic brain fibroblast growth factor

Cell lysates of two established human tumor lines, a medulloblastoma (TE671), and a rhabdomyosarcoma (RD), contain mitogenic activity which elutes from heparin-Sepharose under conditions typical of class 1 heparin-binding growth factors, such as acidic brain fibroblast growth factor. The presence of this class of mitogen in both cell lines was confirmed by their chromatographic behavior on reversed-phase C3 columns, and by the ability of heparin to enhance their mitogenic activity. Using a specific synthetic DNA probe, RNA's were isolated from both cell lines by hybridization-selection, translated in vitro , and translated proteins affinity fractionated on heparin-Sepharose. The results demonstrate that TE671 and RD cell lysates contain mRNA's for mitogens related to acidic brain fibroblast growth factor, and also suggest that high molecular weight proteins exist that are closely related to, or are precursor forms of, the class 1 mitogens.
Cooperative Multicast Strategies under Heterogeneous Link Loss Rates

We consider wireless multicasting over lossy links and explore the benefit of cooperative strategies in which multicast receivers exchange messages. A key feature of the problem considered here is that the source downlink channel has a higher loss rate than the channels between pairs of receivers; this feature implies that completion time may be reduced by offloading transmissions to receiver-receiver links and taking advantage of their higher reliability. Three strategies are analyzed and compared: a strategy in which all transmissions are carried out by the original source node; a strategy in which the original source transmits until it is able to designate a proxy-source among the receiver nodes to complete the multicast; and a strategy in which the original source transmits the minimal number of packets possible and cooperative transmissions among receivers are used to complete the multicast. These strategies are compared in terms of the number of packet transmissions needed to complete the multicast.
An input-capacity-insensitive, charge-sensitive preamplifier for simultaneous use in vacuum with fast amplifiers for charged-particle studies with semiconductor detectors

Abstract A low-noise, charge-sensitive preamplifier was designed for service in a system used for experimental studies of charged particles with the Oak Ridge Isochronous Cyclotron 60-MeV proton beam1). In these studies all charged particles from 1 to 60 MeV produced in targets bombarded by 60-MeV protons were examined and identified by an on-line computer using two methods simultaneously: time-of-flight mass identification, and E by dE/dx mass and charge identification. The first method requires a detector and preamplifier system that can resolve the ∼3-nsec flight-time difference between 10-MeV 3He and alpha particles. The second method requires a system with an energy resolution of 100 keV for 60-MeV protons. The charge-sensitive preamplifier described herein meets these requirements with good versatility and without sacrificing other performance characteristics. The preamplifier consists of a charge-sensitive loop only. Its charge sensitivity is from 54 mV/MeV (in Ge) to as much as 2 V/MeV with from one to three FET's in parallel at the input without the addition of parasitic suppressors. For 1.6-μsec RC-RC pulse shaping, the measured noise of this preamplifier at room temperature is 1.1 keV fwhm (referred to Ge), measured with zero detector capacity but with all other connections made, including a 1-pF test pulse capacity. An input pulse of either polarity is accepted; the maximum output is either ±3.0 V into 93 ω with better than 0.05% linearity. The temperature stability is better than 0.05% from −10° to 50°C, and as measured is determined by the temperature stability of both the charge injection capacitor and the feedback capacitor. The gain stability under prolonged vacuum operation inside a scattering chamber is better than 0.05% for 5 h. To increase the signal received by the fast amplifiers used simultaneously with this charge-sensitive preamplifier and to minimize the loop closure time, no bandwidth suppression is used even for the larger feedback ratios with three FET's. Under these conditions the preamplifier is stable against parasitic oscillations with input cable impedances from 50 to 125 ω, cable lengths continuously variable from 0 to 4 ft, and input capacities at the ends of these cables from zero to several hundred picofarad. One of the necessary design considerations achieved with this preamplifier is that the dc bias conditions are adequate to ensure linear operation over the large dynamic range of energies expected. This includes energy depositions of ∼16 MeV in a 100-μ diode, whose collection time is faster than the response time of the charge-sensitive loop. The design also includes an internal feedback network which when adjusted permits the preamplifier to operate with a detector capacitance from 0 to 100-pF with no detectable change in the output pulse amplitude.
A Reputation-Based Mechanism for Dynamic Virtual Organization Formation in Grids

In order to execute large scale applications programs in grids, several Grid Service Providers (GSPs) pool their resources together by forming Virtual Organizations (VOs). Forming such VOs is a challenging problem especially when the trust relationships among GSPs have to be considered. In this paper, we model the formation of VOs in grids by considering the trust and reputation of the participating GSPs. We design a mechanism for VO formation that enables the GSPs with high reputation to organize into a VO reducing the cost of execution and guaranteeing the maximum profit for the participating GSPs. Furthermore, the mechanism guarantees that the formed VO is stable, that is, the GSPs that are part of the VO do not have incentives to break away from it. We perform extensive simulation experiments using real workload traces to characterize the properties of the proposed mechanism. The results show that the mechanism produces stable VOs composed of GSPs with high reputation that obtain high individual profits.
Complementary MS Methods Assist Conformational Characterization of Antibodies with Altered S–S Bonding Networks

As therapeutic monoclonal antibodies (mAbs) become a major focus in biotechnology and a source of the next-generation drugs, new analytical methods or combination methods are needed for monitoring changes in higher order structure and effects of post-translational modifications. The complexity of these molecules and their vulnerability to structural change provide a serious challenge. We describe here the use of complementary mass spectrometry methods that not only characterize mutant mAbs but also may provide a general framework for characterizing higher order structure of other protein therapeutics and biosimilars. To frame the challenge, we selected members of the IgG2 subclass that have distinct disulfide isomeric structures as a model to evaluate an overall approach that uses ion mobility, top-down MS sequencing, and protein footprinting in the form of fast photochemical oxidation of proteins (FPOP). These three methods are rapid, sensitive, respond to subtle changes in conformation of Cys → Ser mutants of an IgG2, each representing a single disulfide isoform, and may be used in series to probe higher order structure. The outcome suggests that this approach of using various methods in combination can assist the development and quality control of protein therapeutics.
The Global Lysine Price-Fixing Conspiracy of 1992–1995

Market structure and the corporate decision-making practices of several multinational corn refiners fostered implementation of the largest price-fixing conspiracies in modern times. These events have renewed the attention of U.S. antitrust authorities in prosecuting international cartels. Archer Daniels Midland (ADM) and its co-conspirators' direct overcharges to lysine buyers during 1992 through 1995 amounted to at least $70 million, and the total public penalties, private damages, and legal costs exceed $200 million. Price-fixing perpetrators now face monetary exposures five times the amount of the harm imposed on buyers.
Production and characterization of two ependymoma xenografts.

Childhood ependymomas exhibit epidemiologic, anatomic, histologic, and biologic features that distinguish them from other gliomas. Because of their propensity to grow in functionally sensitive regions of the brain, adequate tumor sampling for basic and therapeutic research is limited. We have established xenografts in both subcutaneous and intracranial nude mouse systems (D528 EP-X, D612 EP-X) from the ependymomas of two nonrelated children. Median subcutaneous growth rates (reported in days to grow from 200 mm 3 to 1000 mm 3 ) are 82 days for D528 EP-X (n=10) and 50 days for D612 EP-X (n=10). D528 EP-X grows intracranially with a median postimplantation survival of 85 days (n=10) ; D612 EP produces a median postimplantation survival of 72.5 days (n=10). Both xenografts grow as well-formed masses with no evidence of infiltration into either brain or subcutaneous tissues. While perivascular pseudopalisading is found in both xenografts, true ependymal rosette formation is absent. Ultrastructurally, neither xenograft exhibits cilia, but both produce abundant intermediate filaments. By light microscopy, the neoplastic cells are immunoreactive for the intermediate filaments glial fibrillary acidic protein, vimentin, and nestin. Karyotypically D528 EP exhibits 46,XX,del(6)(q22q26)/46,XX while D612 EP exhibits 50,XX,+X,t(1 ;8)(p11 ;q11),t(1 ;8)(p11 ;q11),+1,-4,der(5)t(4 ;5)(q12 ;q35),+der(5)t(4 ;5)(q12 ;q35),-6,+9, +9,-16,+der(17)t(6 ;17)(p11 ;p11),+mar. Restriction fragment length polymorphism studies comparing the primary brain tumor tissue from each patient against multiple passages of the resulting xenografts confirm the origin of both xenografts. These xenografts represent models on which future studies into the oncogenesis, progression and therapy of ependymomas can be performed.
Identification of a region in the N-terminus of Escherichia coli Lon that affects ATPase, substrate translocation and proteolytic activity.

Abstract Lon, also known as protease La, is an AAA+ protease machine that contains the ATPase and proteolytic domain within each enzyme subunit. Three truncated Escherichia coli Lon (ELon) mutants were generated based on a previous limited tryptic digestion result and hydrogen–deuterium exchange mass spectrometry analyses performed in this study. Using methods developed for characterizing wild-type (WT) Lon, we compared the ATPase, ATP-dependent protein degradation and ATP-dependent peptidase activities. With the exception of not degrading a putative structured substrate known as CcrM (cell-cycle-regulated DNA methyltransferase), the mutant lacking the first 239 residues behaved like WT ELon. Comparing the activity data of WT and ELon mutants reveals that the first 239 residues are not needed for minimal enzyme catalysis. The mutants lacking the first 252 residues or residues 232–252 displayed compromised ATPase, protein degradation and ATP-dependent peptide translocation abilities but retained WT-like steady-state peptidase activity. The binding affinities of WT and Lon mutants were evaluated by determining the concentration of λ N (KλN) needed to achieve 50% maximal ATPase stimulation. Comparing the KλN values reveals that the region encompassing 232–252 of ELon could contribute to λ N binding, but the effect is modest. Taken together, results generated from this study reveal that the region constituting residues 240–252 of ELon is important for ATPase activity, substrate translocation and protein degradation.
Penetration Routes of Topically Applied Eye Medications

Tritium-labeled hydrocortisone acetate and pilcarpine hydrochloride solutions were topically applied to the eyes of rabbits. In one group of animals, the drugs were excluded from contact with the cornea by a cylindrical well glued to the eye surface. In another group, the drug solutions were allowed contact with the entire anterior surface of the eye. Total application time in all cases was five minutes, then the eyes were flushed with saline. Samples of aqueous humor, stroma, and iris-ciliary body were taken after five, 20, 35, 65, and 125 minutes and counted in a liquid scintillation counter. With hydrocortisone, up to 70 times more drug reached the stroma when the cornea was exposed; 40 times more reached the iris. Peak stromal levels occurred by 20 minutes, dropping to one third of peak value by two hours. With pilocarpine, about five times more drug reached the iris-ciliary body when corneal access was allowed; the level peaked in about five minutes. These results illustrate the important role of tear film distribution and blinking in delivering remotely applied drugs over the cornea with subsequent entry to interior sites.
Liquid-Phase Sintering in Thick-Film Resistor Processing

Equations are derived to express the initial-stage neck growth in liquid-phase sintering of particles completely immersed in a liquid. Sintering kinetics are calculated for RuOl neck growth in a lead borosilicate glass, taking into account the effect of the dissolved alumina content of the glass phase. Sintered contacts are shown to be possible under favorable processing conditions and materials and reaction parameters during thick-film resistor processing.
MODELING THE EFFECTS OF RACIAL THREAT ON PUNITIVE AND RESTORATIVE SCHOOL DISCIPLINE PRACTICES

It is clear that schools are mirroring the criminal justice system by becoming harsher toward student misbehavior despite decreases in delinquency. Moreover, Black students consistently are disciplined more frequently and more severely than others for the same behaviors, much in the same way that Black criminals are subjected to harsher criminal punishments than other offenders. Research has found that the racial composition of schools is partially responsible for harsher school discipline just as the racial composition of areas has been associated with punitive criminal justice measures. Yet, no research has explored comprehensively the dynamics involved in how racial threat and other factors influence discipline policies that ultimately punish Black students disproportionately. In this study (N = 294 public schools), structural equation models assess how school racial composition affects school disciplinary policies in light of other influences on discipline and gauge how other possible predictors of school disciplinary policies relate to racial composition of schools, to various school disciplinary policies, and to one another. Findings indicate that schools responding to student misbehavior with one type of discipline tend to use other types of responses as well and that many factors predict the type of disciplinary response used by schools. However, disadvantaged, urban schools with a greater Black, poor, and Hispanic student population are more likely to respond to misbehavior in a punitive manner and less likely to respond in a restorative manner.