cssi/SciSciGPT-SciSciNet huggingface dataset:
Strategies for the assessment of matrix effect in quantitative bioanalytical methods based on HPLC-MS/MS.

In recent years, high-performance liquid chromatography (HPLC) with tandem mass spectrometric (MS/MS) detection has been demonstrated to be a powerful technique for the quantitative determination of drugs and metabolites in biological fluids. However, the common and early perception that utilization of HPLC−MS/MS practically guarantees selectivity is being challenged by a number of reported examples of lack of selectivity due to ion suppression or enhancement caused by the sample matrix and interferences from metabolites. In light of these serious method liabilities, questions about how to develop and validate reliable HPLC−MS/MS methods, especially for supporting long-term human pharmacokinetic studies, are being raised. The central issue is what experiments, in addition to the validation data usually provided for the conventional bioanalytical methods, need to be conducted to confirm HPLC−MS/MS assay selectivity and reliability. The current regulatory requirements include the need for the assessment and...
Maternal dietary fish oil enriches docosahexaenoate levels in brain subcellular fractions of offspring.

Prompted by the speculated essentiality of docosahexaenoic acid (DHA) for neural development, this study was undertaken to investigate the incorporation of (n-3) fatty acids in the maternal diet into various phospholipids of infant rat brain subcellular fractions: microsomes (Ms), synaptosomes (Sy), myelin (My), and mitochondria (Mt). Two groups of infant rats were nourished by dams fed diets containing 20% of either corn oil (CO) or menhaden oil (MO) from 2 until 12 days of age. DHA but not eicosapen taenoic acid (EPA) was distributed to all subcellular fractions of infant rats in the CO group. The levels of DHA were higher in Ms and Mt than Sy and My, and higher in phosphatidylethanolamine (PE) and phosphatidylserine (PS) than phosphadylcholine (PC) and phosphatidylinositol (PI). The MO feeding enriched DHA in PE of all subcellular fractions, PS of all subcellular fractions, except My, PC of Sy, My and Mt, and PI of My. EPA was enriched in phospholipids in all subcellular fractions, except mitochondrial PS of the MO group. In the MO group, the ratios of EPA/ DHA, ranging from 0.01 to 0.85, in all subcellular phospholipids were markedly lower than that found in the mother-s milk (i.e., 1.5), suggesting an ability to elongate and desaturate EPA to DHA and/or disproportional uptake of the fatty acids by the brain. In PE of all subcellular fractions, the increased levels of DHA and EPA, with a concomitant reduction of arachidonic and/or linoleic acid, yielded higher ratios of total (n−3)/(n−6) fatty acids in the MO than the CO group. The inclusion of preformed DHA and EPA in the maternal diet provides an effective means to enrich these fatty acids in developing brains. © 1993 Wiley-Liss, Inc.
Indefinite Kähler submanifolds with positive index of relative nullity

We deal with complex submanifolds in indefinite space forms. In particular, submanifolds with large index of relative nullity are emphasized. In that context, we prove cylinder theorems in terms of indefinite metrics. We also give a systematic way of constructing a family of new complete and closed indefinite complex submanifolds in the projective setting. In the appendix, we show that the method used for complex cases can be applied to real indefinite geometry. We prove real cylinder theorems including B-scrolls in the general signature. We also show two decomposition lemmas which clarify the relationships between the Hartman-Nirenberg cylinder theorem and slanted cylinder theorems in indefinite geometry.
On subdivisions of simplicial complexes: Characterizing localh-vectors

A well-known combinatorial invariant of simplicial complexes is theh-vector, which has been the subject of much combinatorial research. This paper deals withlocal h-vectors, recently defined by Stanley as a tool for studyingh-vectors of simplicial subdivisions. The face-vector of any simplicial complex can only increase when the complex is subdivided; how does theh-vector change? Motivated by this question, Stanley derived certain useful properties of localh-vectors. In this paper we use mainly geometric arguments to show that these properties characterize localh-vectors, andregular localh-vectors.
Telencephalic oligodendrocytes battle it out.

The exact embryonic origins of forebrain oligodendrocytes have been unclear. A new study addresses the question with elegant genetic fate mapping, and concludes that oligodendrocytes are generated in three distinct waves. Oligodendrocytes from later waves eventually replaced those generated in earlier waves, but if one wave was lost, the other waves could compensate.
Lung cancer: retreatment of local recurrence after definitive irradiation.

Aggressive radiation therapy for the management of inoperable lung cancer has increased tumor control and survival. However, approximately 20% of patients continue to experience local recurrence as the sole manifestation of treatment failure. Seven hundred thirty-four patients were initially treated by radiation therapy for inoperable lung cancer, for recurrence after resection, or as adjunct postoperative therapy. Twenty-nine patients were referred for retreatment of cancer that recurred within the original treatment field. Following retreatment, 14 of 29 patients (48%) had a favorable subjective response, and 20 of 27 patients (74%) a favorable objective response. A favorable response was observed for all cell types and over a wide range of retreatment dosages. Symptomatic radiation pneumonitis developed in one patient, rib sclerosis and fracture developed in another. The median survival after onset of retreatment was five months with a range of one month to 54 months. The clinically determined mechanisms of death were persistent intrathoracic disease in 14 of 25 patients (56%), intrathoracic disease and distant metastasis in 7 of 25 (28%), distant metastasis in 3 of 25 (12%), and unknown in 1 of 25 (4%).
Seeking the truth in a world of chance

Abstract An object of fascination throughout history, the concept of chance has assumed a dominant role in contemporary life. Statistical inference, reaching maturity in the twentieth century, has transformed science and is at the basis of much of our modern technology. But the century just past also revealed to us the intrinsic limitations of scientific knowledge, yielding the conclusion that science will never be able to explain all of reality. There is a pervasive uncertainty concerning absolutes. Our notion of truth is that of statistical truth, derived from fallible observations. Focusing on the statistical approach as a way to seek consensus in our pluralistic culture, the author presents an “ethics of evidence” for dealing with uncertainty. The ethics of evidence poses two complementary rules: it calls for the best possible evidence in human affairs, and it urges open acceptance of uncertainty—irreducible scientific and existential uncertainty. It is not meant as an abstract theory, but as a practical inquiry into how we should live our lives in a world of uncertainty. Its aim is a synthesis that unifies the accumulating insights of diverse disciplines in the search for ultimate meaning. The theme of this essay is illustrated by reference to the integrated thought of Pascal, founder of probability theory and seminal thinker of the seventeenth century.
Mitigation of Colitis with NovaSil Clay Therapy

Five million people currently live with Crohn’s disease (CD) or ulcerative colitis, the two major forms of inflammatory bowel disease. Available treatments frequently result in side effects that compromise the immune health of the patient. Consequently, alternative therapies that cause fewer systemic effects are needed. Dioctahedral smectite clays have been utilized to treat medical conditions, including diarrheal and enteric disease. Herein, we report the ability of a refined dioctahedral smectite (NovaSil, NS) to sorb inflammatory proteins and reduce inflammation in a TNBS (2,4,6-trinitrobenzenesulfonic acid) mouse model of CD. We also investigated whether NS could rescue gut microbial diversity in TNBS-induced mice. ELISA, X-ray diffraction, and transmission electron microscopy were employed to characterize the NS–cytokine interaction in vitro. A TNBS mouse colitis model was utilized to study the efficacy of NS supplementation for 4 weeks. The three treatment groups included control, TNBS, and TNBS + NS. DNA was extracted from feces and sorted for bacterial phylogenetic analysis. Results suggest that NS binds TNFα in vitro. In TNBS-treated mice, supplementation with NS significantly reduced weight loss, and serum proinflammatory cytokine levels (IL-2, IL-6, and IL-12, TNFα, IFNγ) compared with the TNBS group. TNBS-treated mice demonstrated a significant reduction in gut microbiota species richness when compared with the TNBS + NS group and control group. NovaSil mitigated the effects of TNBS-induced colitis based on reduction in systemic markers of inflammation, significant improvement in weight gain, and intestinal microbial profile.
Synthesis of nickel nanoparticles supported on nanoporous silicon oxycarbide (SiCO) sheath-core fibers

Nickel (Ni) nanoparticles with average diameters less than 5 nm were successfully synthesized on nanoporous silicon oxycarbide (SiCO) sheath−core fibers by incipient wetness impregnation of Ni acetylacetonate precursor followed by reduction at temperatures above 250 °C. The SiCO fibers were fabricated by pyrolyzing electrospun 5/15 PUS/PMMA composite fibers at temperatures from 250 to 1000 °C to contain nanoporous cores and striated sheaths. The SiCO fibers pyrolyzed up to 600 °C were superhydrophobic and became superhydrophilic when pyrolyzed at 800 °C and above. Such a drastic switch from superhydrophobicity to superhydrophilicity coincided with the disappearance of aliphatic methyl and methylene groups. The SiCO ceramic fibers pyrolyzed at 1000 °C were highly porous with BET surface area 95.7 m2/g, pore volume 0.352 cm3/g, and average pore size 26 nm. They were thermally and chemically stable enough to support the Ni acetylacetonate precursor to be reduced to Ni nanoparticles at 250, 500, and 900 °C. S...
Direct characterization of the hydroxyl intermediate during reduction of oxygen on Pt(111) by time-resolved electron energy loss spectroscopy

Abstract The formation of hydroxyl (OH) and the subsequent production of water in the reaction of hydrogen gas with adsorbed atomic oxygen on Pt(111) at low temperatures (130⩽ T ⩽165 K) and pressures (2×10 −10 ⩽ P H 2 ⩽1×10 −9 Torr) have been studied using time-resolved electron energy loss spectroscopy (TREELS). The time evolution of the OH intermediate is found to be inadequately fit by models involving reaction of adsorbed atomic hydrogen with adsorbed oxygen. We propose a reaction which proceeds via a molecular hydrogen precursor at the boundaries of atomic oxygen islands. The activation energies for the formation of hydroxyl and water are 2.8±0.3 and 4.2±0.3 kcal mol −1 , respectively.
Syntheses That Stay Together

An old principle of macromolecular biosynthesis in bacteria is that the speed of protein synthesis (translation) matches that of messenger RNA (mRNA) synthesis (transcription), but how this integration occurs has not been clearly defined. An obvious conjecture is that ribosomes move along the emerging mRNA at whatever speed RNA polymerase goes so that translation and transcription remain coordinated, as it is known to do when conditions change ( 1 ). However, on page 504 ( 2 ) and 501 ( 3 ) of this issue, Proshkin et al. and Burmann et al. , respectively, suggest the opposite: Efficient binding and progression of ribosomes along mRNA increase the speed of RNA polymerase, whereas the absence of ribosomes allows the polymerase to slow and wait for ribosomes to catch up.
Drivers of Oxidative Stress in Acute Pancreatitis The Role of Nutrition Therapy

Severe acute pancreatitis is a disease process distinguished by increasing oxidative stress and potential destruction of the pancreatic gland. An initial injury to the acinar cell initiates a sentinel event, which leads to a vicious cycle of inflammation and cell death by either apoptosis or necrosis. Whether the acute inflammation resolves or goes on to a pattern of chronicity may be related to genetic predisposition, failure to remove injurious agents, and innate systems for antioxidant defense. The degree to which nutrition therapy can modulate oxidative stress, maintain intestinal function, and preserve the structure of the acinar cell is truly amazing. Understanding the mechanisms involved in this complex disease process and the manner in which these mechanisms are influenced by dietary agents affords new and exciting therapeutic options for the future.
Effects of Voltage and Distance on Stand-Alone Lance Electrodes During Repulsion

This paper explores the effects of two parameters—operation voltage and the distance between the lance and electrode—on the repulsion process of a Stand-Alone Lance, a second-generation Nanoinjection tool used to inject DNA into egg cells for genetic purposes. Using a mathematical computer model to simulate the motion of the DNA during repulsion from the lance and into the cell, the results are quantified by the average DNA travel time and the electric field strength, which relates to the electroporation envelope. It is found that voltage has a very strong effect, while changing distance yields much less dramatic results. Specific ideal values are recommended for the magnitude and duration of the voltage pulse to successfully repel DNA into the cell.Copyright © 2012 by ASME
UniRef: comprehensive and non-redundant UniProt reference clusters.

Motivation Redundant protein sequences in biological databases hinder sequence similarity searches and make interpretation of search results difficult. Clustering of protein sequence space based on sequence similarity helps organize all sequences into manageable datasets and reduces sampling bias and overrepresentation of sequences. Results The UniRef (UniProt Reference Clusters) provide clustered sets of sequences from the UniProt Knowledgebase (UniProtKB) and selected UniProt Archive records to obtain complete coverage of sequence space at several resolutions while hiding redundant sequences. Currently covering >4 million source sequences, the UniRef100 database combines identical sequences and subfragments from any source organism into a single UniRef entry. UniRef90 and UniRef50 are built by clustering UniRef100 sequences at the 90 or 50% sequence identity levels. UniRef100, UniRef90 and UniRef50 yield a database size reduction of approximately 10, 40 and 70%, respectively, from the source sequence set. The reduced redundancy increases the speed of similarity searches and improves detection of distant relationships. UniRef entries contain summary cluster and membership information, including the sequence of a representative protein, member count and common taxonomy of the cluster, the accession numbers of all the merged entries and links to rich functional annotation in UniProtKB to facilitate biological discovery. UniRef has already been applied to broad research areas ranging from genome annotation to proteomics data analysis. Availability UniRef is updated biweekly and is available for online search and retrieval at http://www.uniprot.org, as well as for download at ftp://ftp.uniprot.org/pub/databases/uniprot/uniref. Supplementary information Supplementary data are available at Bioinformatics online.
Direct Acylation of Carrier Proteins with Functionalized β-Lactones

As the key component of many biosynthetic assemblies, acyl-carrier proteins offer a robust entry point for introduction of small molecule probes and pathway intermediates. Current labeling strategies primarily rely on modifications to the phosphopantetheine cofactor or its biosynthetic precursors followed by attachment to the apo form of a given carrier protein. As a greatly simplified alternative, direct and selective acylation of holo-acyl-carrier proteins using readily accessible β-lactones as electrophilic partners for the phosphopantetheine-thiol has been demonstrated.
Scope and Impact of Early and Late Preterm Infants Admitted to the PICU with Respiratory Illness

Objective To determine the clinical course and outcomes of children born early preterm (EPT, Study design Retrospective chart review of patients Results Two hundred seventy-one patients met inclusion criteria: 17.3% were EPT, 12.2% were LPT, and 70.5% were FT. Lower respiratory tract infection was the most common diagnosis (55%) for all groups. Median PICU length of stay was longer for EPT (6.3 days) and LPT infants (7.1 days) compared with FT infants (3.7 days; P P P = .004, respectively). Median hospital charges were also greater for EPT ($85 151) and LPT ($83 576) groups compared with FT group ($55 122; P P Conclusions EPT and LPT infants comprise a considerable proportion of PICU admissions for respiratory illness and have greater resource utilization than FT infants.
Validation of a Frequency Weighted Filter for Repetitive Wrist Flexion Tasks against a Load

This experiment validates an instrument that implements a force and frequency weighted filter for biomechanical stress exposure assessment. This filter network was developed based on a previously established discomfort model that associated physical stress of force, posture and repetition with subjective discomfort. A simulated industrial task was used in the current study to test the instrument involving repetitively transferring a peg and inserting it into a hole against a controlled resistance. Ten subject performed the task for six conditions. Continuous wrist angular data were recorded using an electrogoniometer and processed through the filter. Subjective discomfort was reported after performing the task for one hour using a 10 cm visual analog scale. The discomfort model was shown to estimate relative discomfort for the experimental conditions tested (r2 = 0.98, p < .05). Linear regression analysis showed that the instrument aptly predicted subjective discomfort (r2 = 0.87, p < .05). Applications a...
Density functional theory and ab initio study of CH3NC and HNC isomerization

Abstract The LSDA, B3LYP, and BLYP have been evaluated as a practical tool for the theoretical study of isomerization reactions on the example of CH 3 NC → CH 3 CN and HNC → HCN isomerization. The results are compared with experimental and RHF, MP2, and QCISD(T) computed values. The study was performed by using a variety of basis sets, from small 3–21G to large 6–31l + + G(3df,3pd).
A cybernetic model of obsessive-compulsive psychopathology

Abstract Analysis of various kinds of obsessive-compulsive psychopathology (perfectionism, doubt, indecision, omnipotence, overspecification, obsessions and compulsions, tics) from a control systems standpoint reveals that all have in common persistent high error signals that cannot be eliminated by behavioral output. Possible causes include conflict, intrinsic comparator defect, and attentional disturbance. The cybernetic approach offers the possibility of eventual neuroanatomical structural correlation, and it is suggested that the limbic system and basal ganglia together form a behavioral control system, dysfunction in which may be manifest as obsessive-compulsive disorder.
Development Of Lightweight, Glass Mirror Segments For The Large Deployable Reflector

Accomplishments in the development of lightweight, honeycomb-core, sandwich mirror blanks made of borosilicate and high-silica glasses at the University of Arizona for the Large Deployable Reflector program are described. In this paper, work spanning the last 2 years is reported, highlighting a new mirror blank fabrication technique that permits the fabrication of the honeycomb core integrally with the front and back plates of the blank in a single furnace cycle. Two types of mirror blanks made by this method, an off-axis, aspheric segment and a smaller Vycor circular piece, are described. The fabrication of two off-axis, aspheric mirror segments is also described. Cryogenic test results are included on the test of a 38-cm diameter, lightweight, honeycomb core, sandwich mirror made of Pyrex.
A Comment on the Liptay Method for the Determination of the Equilibrium Constants of Complexes Using Spectrophotometric Absorption Measurements

Liptay developed a method for the determination of the equilibrium constants for complexes from spectrophotometric absorption measurements [1]. He stated that a certain set of equalities would only hold true if the extinction coefficients of the complex were independent of concentration. In this paper it is shown that this set of equalities will hold true as long as the extinction coefficients have the same concentration dependence. The set of equalities fail when a new complex peak appears and changes the shape of the absorption curve. Liptay entwickelte ein Verfahren zur Ermittlung von Komplexbildungskonstanten aus spektralphotometrischen Absorptionsmessungen [1]. Er zeigt, das ein bestimmtes Gleichungssystem nur dann erfullt ist, wenn der Extinktionskoeffizient des Komplexes konzentrationsunabhangig ist. In dieser Arbeit wird gezeigt, das dasselbe Gleichungssystem auch dann noch erfullt ist, wenn alle Extinktionskoeffizienten die gleiche Konzentrationsabhangigkeit haben. Das Gleichungssystem wird erst dann nicht mehr erfullt, wenn ein neuer Komplex auftritt und damit die Form der Absorptionskurve geandert wird.
Small Circuit Double Covers of Cubic Multigraphs

Let G be a two-connected graph. A family F of circuits of G is called a circuit double cover (CDC) if each edge of G is contained in exactly two circuits of F. In this paper, we show that if a simple cubic graph G (G ? K4) of order n has a CDC, then G has a CDC containing at most n/2 circuits. This result establishes the equivalence of the circuit double cover conjecture (due to Szekeres, Seymour) and the small circuit double cover conjecture (due to Bondy) for any cubic graph. Actually, a stronger result is obtained in this paper for all loopless cubic graphs. Another result in this paper establishes an upper bound on the size of any CDC of a cubic graph.
Inaccuracy of the x2 Test of Goodness of Fit When Expected Frequencies Are Small

Abstract In applied statistics there is an increasing tendency toward leniency regarding minimum expectation prerequisite to Pearson's X 2 test for goodness of fit, based on various empirical studies of the distribution of X2 in sampling from multinomial populations with given parameters. In this study it is shown that the chi-square probabilities of X 2 may differ markedly from the exact cumulative multinomial probabilities. Contrary to prevailing opinion, the approximation did not improve, when samples were small, as expectation increased nor as the number of categories or degrees of freedom increased.
The Effect of Kilovar Supply on the Design of Systems for Load Growth

The benefits that can be obtained by the use of shunt capacitors in electric power systems have been discussed many times in the technical literature. Their ability to improve voltage and power factor in the distribution areas, thereby reducing losses and postponing the need for additional circuit capacity by reducing loading on existing equipment, has been used many times where the economics have justified such use.
MICROTUBULE ORGANIZING CENTERS AND GAMMA -TUBULIN

Abstract The polar assembly of cellular microtubules is organized by microtubule organizing centers (MTOCs). Eukaryotic cells across different species, and different cell types within single species, have morphologically diverse MTOCs, which have the common function of organizing microtubule arrays by initiating microtubule assembly and anchoring microtubules by their slow-growing ‘minus’ ends, thus ensuring that the rapidly growing ‘plus’ ends extend distally. The past few years have witnessed a variety of approaches aimed at defining the molecular components of the MTOC that are responsible for regulating microtubule assembly by defining molecules common to all MTOCs.
Damage Induced Production of Extrafloral Nectaries in Native and Invasive Seedlings of Chinese Tallow Tree (Sapium sebiferum)

We conducted a pot experiment examining the effects of simulated leaf herbivory and supplemental soil nutrients on extrafloral nectary (EFN) glands of Sapium sebiferum seedlings derived from native Chinese and invasive Texas seed stock. We predicted that simulated herbivory and increased soil nutrients would increase EFN activity. We also predicted that Chinese genotypes would have greater EFN activity than Texas genotypes. Simulated leaf herbivory significantly stimulated effluent production on EFN glands of seedlings from both genotypes, but there were no significant differences in EFN activity between genotypes or nutrient treatments.
Comprehensive Soldier Fitness and the Future of Psychology.

Psychology responded to the national needs in World War I and World War II and was itself transformed. National need calls a third time: unprecedented levels of posttraumatic stress disorder, depression, suicide, and anxiety along with a need for a resilient Army capable of meeting the persistent warfare of the foreseeable future. As a large part of the Comprehensive Soldier Fitness program, positive psychology is meeting this need with new tests, with new fitness courses, and with resilience training. These developments may transform the practice of psychology and psychology's relation to medicine and education.
Lung infections in pediatric lung transplantation: experience in 49 cases

Objectives: Pulmonary infections, and particularly cytomegalovirus (CMV) infections, are a major cause of morbidity after lung transplantation. We report here our results in 49 pediatric lung transplantations. Methods: Between may 1988 and 1997, we have done 49 lung transplantations in 42 children (en bloc double lung transplantation (DLT):10, HLTx:7, sequential bilateral sequential-lung transplantation (BSLT):31, single-lung transplantation (SLT): 1). In seven, it was a retransplantation. Among these, 34 were cystic fibrosis (CF) patients, all with multiresistant organisms ( Pseudomonas aeruginosa, Burkholderia cepacia, Achromobacter xylososydans, Staphyloccus aureus). All patients were treated with multiantibiotic prophylaxy adapted to the preoperative cultures. Donor-recipient CMV matching was possible in only 31 cases. CMV prophylaxy and immunosuppression protocols have evolved with time, with a current protocol of IV Gancyclovir prophylaxy for 3 months and triple drug immunosuppression without post-operative rabbit anti-thymocyte globulin (RATG) induction. There was no perioperative mortality in the primary transplantations and three early deaths in the whole group (6.1%). Results: Only five patients had no pulmonary infection. The patients presented 3.2 infection episodes per year, 75% localized on the lungs, 41% during the first 3 months. Among the 13 deaths in the 1st year, 10 were directly related to infection, 60% due to CMV. After the 1st year, in all patients dying of pulmonary dysfunction or obliterative bronchiolitis (OB), bacterial infections were associated. There was no serious fungal infection. Actuarial survival at 3 months, 1, 3, 5 years were 85, 65.7, 47.5 and 28.5%, respectively. There was a significant difference in 3 year survival between patients receiving CMV negative organs (40%) and CMV positive organs (17%). Conclusion: In our experience, as in other’s, pulmonary infection risk is important in lung transplantation. Bacterial infections were mainly an aggravating factor of secondary pulmonary dysfunction or OB, and were not the primary cause of death. CMV infections have been very severe and lead us, despite the scarcity of donors, to avoid positive donors in negative recipients, this leads to disastrous mid-term results in our experience, despite prophylaxis. © 1999 Elsevier Science B.V. All rights reserved.
Systems for metadata: documenting scientific databases

The SIPP ACCESS information system was organized into a relational database. RDBMSs automatically provide system catalogs of relations and attributes, giving unique labels to every distinct measure in SIPP. Five features of additional metadata created are noteworthy. The data dictionary for all repeated measures was concatenated in a single document that could be retrieved by label, or by knowledge of naming conventions on the questionnaire. The relational calculus was used to describe the graph of the questionnaire. The third innovation consisted of a relation on relations, Tablelist, that described the content of each relation and the unit of analysis to which it referred. A bibliographic database of technical memoranda and reports derived from the data was created. The final innovation was to create a reporting system for the logged use of different parts of the database, communication with the staff, and the progress of scientific findings and errors detected through SIPP ACCESS. >
Regulation of Bcl-xl Channel Activity by Calcium

Abstract Recent studies have demonstrated that the anti-apoptotic proteins, Bcl-2 and Bcl-xl, with the carboxyl-terminal hydrophobic domain removed, form cation-selective channels in the lipid bilayer reconstitution system. However, the regulatory properties of these channels are unknown. In this study, we investigated the ion-conducting properties of full-length Bcl-xl in the lipid bilayer reconstitution system. Our findings indicate that Bcl-xl forms a cation-selective channel that conducts sodium but not calcium and that Bcl-xl channel activity is reversibly inhibited by luminal calcium with a half-dissociation constant of ∼60 μm. This calcium-dependent regulation of the Bcl-xl channel provides new insights into the roles of calcium and Bcl-2-related proteins in the programmed cell death pathway.
Optimal transmit-diversity precoders for random fading channels

Optimal transmitter-receiver designs obeying the water-filling principle are well-known and widely applied when the propagation channel is deterministically known and frequently updated at the transmitter. Because the latter may be costly or impossible to acquire in rapidly varying wireless environments, we develop in this paper statistical water-filling-like criteria for stationary random fading channels. The resulting optimal designs require only knowledge of the channel's correlation matrix that does not require frequent updates and can be easily acquired. Applied to a multiple transmit-antenna paradigm, the optimal precoder and loading algorithm outperform not only the conventional equal-power allocation across all antennas but also their deterministic water-filling counterparts in fast fading scenarios.
Parallel optical interconnect at 10 Gb/s per channel

In many high-end systems, there is a growing need to replace copper interconnects with optical interconnects for link lengths up to 600 meters. 12-channel parallel-optical interconnects with each channel operating at a data rate up to 10 Gb/s are designed, assembled, and demonstrated. This is achieved using bottom-emitting 990-nm VCSELs and bottom-illuminated photodetectors (PDs) flip-chip bonded directly to 12-channel transmitter and receiver integrated circuits, respectively. Results show a 12-channel parallel-optical transmitter module operating at a data rate of 10 Gb/s per channel with all 12 channels operating simultaneously. In addition, a 12-channel parallel-optical receiver module with each channel operating at a data rate up to 10 Gb/s with all channels operating simultaneously is demonstrated. A BER <10/sup -12/ is measured on a single channel operating at a data rate of 10 Gb/s with all 12 channels operating simultaneously after transmission over 100 meters of 50-/spl mu/m core standard multimode ribbon fiber.
Structural group classification technique based on regional fMRI BOLD responses

This paper presents a new multigroup classification method based on subtle differences in regional brain activity during the completion of a functional magnetic resonance imaging (fMRI) challenge paradigm. Classification is performed based on features derived from BOLD time intensity curves in selected regions of interest (ROI). For each ROI, a mean time intensity curve [called mean regional response (MRR)] is calculated from realigned and normalized datasets. The overall subject performance is characterized with a vector of features obtained using nonlinear modeling of all subject's MRRs with a mixture of time shifted Gaussian functions. The classification is performed in the reduced-dimension optimal discrimination space, obtained through canonical transformations of original feature space. In order to demonstrate feasibility of the proposed method, classification of three groups of subjects is presented. The three groups are defined as heavy marijuana smokers after 24 hours of abstinence, heavy marijuana smokers after 28 days of abstinence, and healthy nonusing controls. The proposed method can be useful as an analytic tool for the discrimination of different groups of subjects based on temporal features of functional magnetic resonance imaging activation.
Groundwave propagation along three-section mixed paths

Recent theoretical work on the propagation of groundwaves along 2-section mixed paths is extended to 3-section paths. A corroborating experiment was conducted at a microwave frequency of 4.29 Gc/s (λ = 7 cm), using water to simulate imperfectly conducting mediums and aluminium plates to simulate perfectly conducting mediums. The experimental results show that the theoretical solutions are accurate to within a few per cent., provided that both aerials are at least a fraction of a wavelength from the separation boundaries.
Larval sea lamprey release two unique bile acids to the water at a rate sufficient to produce detectable riverine pheromone plumes

The discovery that the olfactory system of the anadromous sea lamprey is extremely sensitive to two unique bile acids (petromyzonol sulfate [PS] and allocholic acid [ACA]) produced by stream-resident larval conspecifics has lead us to hypothesize that these compounds function as a migratory pheromone. Here, we test whether lamprey release these bile acids to the water in quantities sufficient for them to function as a long distance attractant. Five experiments were conducted. First, high performance liquid chromatography (HPLC) of liver extracts from all three life history stages of this species established that only larvae produce PS and ACA; parasites and maturing adults produced no identifiable bile acids. Large quantities of PS and ACA were found in larval gall bladders. Second, HPLC analyses of larval lamprey holding waters established that recently-fed larvae held in the laboratory release these bile acids to the water, with PS being released at a rate of approximately 16 ng h−1 animal−1 and ACA at 5 ng h−1 animal−1. Fasted animals released little bile acid. Third, an investigation of bile acid release routes demonstrated that larvae release bile acids primarily via their feces. Fourth, a study of the stability of ACA and PS in river water found both to have a half-life of a day. Finally, theoretical extrapolations using these data suggest that PS and ACA are present in picomolar concentrations in lamprey streams, a concentration within the detection range of adults. In conclusion, these data demonstrate for the first time in a fish that bile acid release rates and modes are adequate for these compounds to have pheromonal function.
Ethno-Racial Identity Displays on Facebook

The present study investigates self-presentation in a nonymous setting and explores differences in self-presentation by distinct ethno-racial groups. Based on content analysis of 83 Facebook profiles of African Americans, Latino, Indian and Vietnamese ancestry students, supplemented by 63 in-person interviews, we found that ethno-racial identities are salient and highly elaborated. The intensive investments of minorities in presenting highly social, culturally explicit and elaborated narratives of self reflect a certain resistance to the racial silencing of minorities by dominant color-blind ideologies of broader society. In the nonymous environment of Facebook, various dimensions of identity claimsappear to be grounded in offline realities as revealed in interviews and observations of campus social dynamics.
A First Study of Perfectionism and Multidimensional Life Satisfaction among Adolescents

Current conceptualizations of perfectionism view the construct as consisting of two subtypes: adaptive and maladaptive. Although research in perfectionism has investigated negative outcomes such as depression and anxiety, little research has investigated how a general sample of children identified as perfectionists differentially might perceive their quality of life. In this exploratory study, a total of 132 middle school students were administered the Almost Perfect Scale-Revised and the Multidimensional Students' Life Satisfaction Scale. Results indicated that both perfectionist subtypes reported significantly higher global satisfaction than did nonperfectionists, whereas adaptive perfectionists reported significantly higher satisfaction ratings on self-satisfaction than both maladaptive and nonperfectionists. Implications of these findings are suggested.
Protein kinase C enhances recombinant bovine α1β1γ2L GABAA receptor whole-cell currents expressed in L929 fibroblasts

Summary The β1 and γ2L subunits of the γ-aminobutyric acid type A receptor (GABAR) contain phosphorylation sites for PKC. To determine the effect of PKC on GABAR function, whole-cell recordings were obtained from mouse fibroblasts expressing recombinant α1β1γ2L receptors, and catalytically active PKC (PKM) was applied via the recording pipette. The first experiment was a population study. Intracellular application of PKM increased GABAR currents, and the enhancement was antagonized by coapplication of the PKC inhibitory peptide. No acceleration or deceleration of GABAR desensitization was observed. The second experiment was a reimpalement study in which paired recordings were made successively from individual cells. Enhancement of GABAR currents by PKM was again obtained. PKM increased GABAR currents at high (>10 μM) but not at low (>10 μM) GABA concentrations, resulting in increases in both EC 50 and maximal GABAR current. Thus, PKC phosphorylation enhanced recombinant α1β1γ2L GABAR current by increasing maximal current without increasing the affinity of GABA for the GABARs.
Penile Basal Cell Carcinoma: Two Cases Treated with Mohs Micrographic Surgery and Remarks on Pathogenesis

Huyen Nguyen, MD, Payam Saadat, MD, and Richard G. Bennett, MD, have indicated no significant interest with commercial supporters.
Minding Your Neighborhood: The Spatial Context of Local Redistribution*

Objectives. Previous research on redistribution by local governments has not accounted for spatial context. I develop a model of local own-source redistributive spending that accounts for the economic characteristics and policy decisions of geographic neighbors. Methods. I estimate a modified spatial 2SLS equation of own-source redistributive spending that accounts for endogeneity between neighboring policy decisions and own policy decisions. The data set spans the 48 contiguous states and utilizes data from the 2000 Census and the 1997 Census of Governments, among other sources. Results. I find that the policy choices and economic characteristics of jurisdictional neighbors are significantly related to own-source housing and community development spending decisions. Jurisdictions reduce their redistributive policies to prevent unwanted movers from entering and produce redistributive packages similar to surrounding jurisdictions. Conclusions. The nuances of geographic context are a critical determinant of local redistributive spending decisions.
O egregie grammatice : the vocative problems of Latin words ending in -ius

A long-lasting and sometimes acrimonious debate over the correct vocative form of second-declension Latin words in -ius began more than 800 years ago. For the past century most classicists have considered the matter to be settled, and little discussion on the subject has taken place. Yet the century-old conclusions we now so unthinkingly accept are based on very little evidence and are internally inconsistent in some of their details. The past hundred years have provided us not only with more Latin to work with, better tools for search and analysis, and a more complete knowledge of the history of the Latin language, but also with a new understanding and respect for the ancient grammarians and their views on the structure of their language. It is time to re-examine the ancient and modern views on the vocative of -ius words, to see whether any viable conclusions can be drawn and whether the ancient grammarians may have more to contribute than our predecessors believed.
Heavy quark solitons.

We investigate the heavy baryons which arise as solitonic excitations in a heavy meson'' chiral Lagrangian which includes the light vector particles. It is found that the effect of the light vectors may be substantial. We also present a simple derivation which clearly shows the connection to the Callan-Klebanov approach.
Where are They? Implications of Ancient and Future Migrations

Some of my more strident space-enthusiast friends wear T-shirts that say, “The meek shall inherit the Earth…the rest of us are going to the stars!” That may strike some as being overly optimistic at best, but I believe there is a grain of truth to it. Whenever I talk about space colonization or one-way voyages to the stars someone usually asks, “Who would want to go?” Usually someone else will the chime in, “l’ll go!” Not only do people come in various sizes and shapes and colors, they look at the world in many different ways. I grew up in the suburbs of New York and knew people who had literally never been west of the Hudson River and had no intention of ever going. New York was comfortable. There is nothing wrong with that attitude. It is just that for many people such a life is not right for them. I went west as soon as I had the chance. I do not regret having left and am much more comfortable where I am now. As I have gotten older, I have found myself settling in and, although I like to travel, I am beginning to understand how those sedentary New Yorkers felt. The only difference is that I settled down a little later in life and in a different place from where I started. But some people never lose that need for adventure, that wanderlust, that need for a radical change, and new places. These are the people who will blaze the trail to the stars.
Hysteresis affects approximate number discrimination in young children.

Perceptual decisions are often affected not only by the evidence gathered during a trial but also by the history of preceding trials. This effect—termed perceptual hysteresis—provides evidence for how perceptual information is represented and how it is used. The present research focuses on how the difficulty of preceding trials affects subsequent ones—we find that how well 5-year-old children perform in a 2-alternative forced-choice numerical discrimination task depends on whether they have had a prior history of easier discriminations or a prior history of harder discriminations. Furthermore, this effect is modulated by the feedback children receive. In 3 experiments, we demonstrate that these effects are not related to practice or loss of interest due to negative feedback, or simply to trial difficulty or discriminability. Instead, children appear to have state-dependent confidence states such that prolonged experience making low-confidence decisions degrades performance, whereas prolonged experience making high-confidence decisions improves it. These results are discussed in the context of dynamical psychophysics, representations of confidence, and work on children’s and adults’ number perception abilities.
Phenacomys longicaudus (Tree mouse)

Unpublished data collected thus far on the chromosome constitutions of Phenacomys longicaudus showed a complex situation, with diploid numbers ranging from 40 to 52, depending upon localities. M. L. Johnson separated this group of animals from Phenacomys to create the genus Aborimus. It is not known, however, how many species can be recognized within Aborimus. Johnson also hybridized individuals with 52 chromosomes (depicted here) and those with 42 chromosomes. The hybrids showed 46 chromosomes as expected with many trivalents in male meiosis.
Enrichment Seminar and the Socio-Emotional Needs of Adolescents

The purpose of this qualitative case study is to explore gifted alumni perceptions of how participating in an Enrichment Seminar course met their socio-emotional needs as they relate to identity formation, and whether or not their academic achievement was influenced. The researcher used interviews, narrative questions, and surveys to gather data. The sample consisted of 30 participants who were surveyed using The Gifted Program Evaluation survey, which included narrative questions. The interview sample came from the population of 30, and included 15 participants. The participants for this study were from both genders, between the ages of 19 and 23 years old, and were of various ethnicities. The results reflect that participants perceived the Enrichment Seminar positively influenced their identity formation through self-knowledge provided by the curriculum, and relationship building. The participants also perceived that participation in the Enrichment Seminar course positively influenced their academic achievement through college and career preparation.
The coding of literary form: Data mining and the information structure of historical texts

This working paper argues that many data-mining projects in the humanities limit themselves by choosing words as their default unit of analysis. Some authors, problems, and forms are better illuminated by analysis of individual textual symbols, others by examination of multiword constructions. Insights about the nature of code from mathematical information theory, long but perhaps prematurely rejected by humanists on theoretical grounds, may give researchers less subjective and more powerful tools by which to measure the information characteristics of texts and the innovations of specific historical writers.
Electric Discharge in Rarefied Gases: The Dominion of Experiment. Faraday. Plücker. Hittorf

The phenomena connected with the discharge of electricity through rarefied gases were observed shortly after the invention, in mid-17th century, of the air pump and the static electrical machine.1 The colourful displays usually were attributed to chemical changes occurring in the gas, but on occasion they were thought to represent the metallic spectra caused by volatilization and ignition of the electrodes.2 These phenomena often were regarded mainly as curiosities to be demonstrated in public by amateur investigators, of which there were many in England. In the late 1830s, Michael Faraday’s experiments on electrical discharge in attenuated gases gave a new prominence to the subject. Over several decades these discoveries served to stimulate critical investigations at home and on the Continent, notably in Germany.
The growing impact of the HIV/AIDS pandemic on children born to HIV-infected women.

The increasing numbers of children bom to HIV-infected women poses formidable problems for maternal and child health programs throughout the world. Between 20% and 40% of these children will be infected with HIV and most are expected to die by the age of 5 years as a result. The vast majority of the uninfected children will be orphaned before age 15 years as their mothers and fathers die of AIDS. By the late 1990s, several hundred thousand children will be bom annually to HIV-infected women in developing countries, with the majority in sub-Saharan Africa and Asia compared with a few thousand in North America.