cssi/SciSciGPT-SciSciNet huggingface dataset:
Ultrastructural evidence for prominent postsynaptic localization of alpha2C-adrenergic receptors in catecholaminergic dendrites in the rat nucleus locus coeruleus.

Alpha-2-adrenergic receptor (α2-AR) agonists potently inhibit the activity of noradrenergic neurons of the locus coeruleus (LC), an effect that may be mediated by the A- and/ or C-subtypes of α2-AR (α2A- and α2C-AR). To gain insight into the functional significance of these α2-AR subtypes in the LC, we have examined their ultrastructural localization by using subtype-specific antibodies. We recently demonstrated that α2A-ARs are localized prominently in axon terminals and catecholaminergic dendrites in the LC. In the present study, we sought to identify the subcellular substrates underlying α2C-AR actions in the LC by analyzing the ultrastructural distribution of α2C-AR immunoreactivity (α2C-AR-IR) in sections that were dually labeled for the catecholamine-synthesizing enzyme tyrosine hydroxylase (TH). Alpha-2C-AR-IR was predominantly localized in dendrites, most of which also contained immunolabeling for TH. Within such dendrites, α2C-AR-IR was associated with the plasma membrane and occasionally Golgi cisternae and tubulovesicles. The vast majority of dendrites containing α2C-AR-IR received asymmetric (excitatory) contacts from unlabeled axon terminals that often contained dense core vesicles. Alpha-2C-AR-IR was observed in some unmyelinated axons and astrocytic processes that were apposed to TH-immunoreactive dendrites but was rarely associated with axon terminals. These results provide the first ultrastructural evidence that α2C-ARs (1) are localized postsynaptically in catecholaminergic neurons of the LC and (2) may be strategically situated to modulate the activation of LC neurons by excitatory inputs. J. Comp. Neurol. 394:218–229, 1998. © 1998 Wiley-Liss, Inc.
TWISTED POINCARE GROUP AND SPIN-STATISTICS

Recently it has been shown that it is possible to retain the Lorentz-invariant interpretation of the non-commutative field theory.1,2,3 This was achieved by the means of the twisted action of the Poincare group on the tensor product of the fields. We investigate the consequences of this approach for the quantized fields.
Progress toward Rapid and Accurate Staphylococcus aureus Strain Typing

Staphylococcus aureus , especially methicillin-resistant S. aureus (MRSA),1 continues to be one of the most important bacterial pathogens in humans and is responsible for a constantly increasing number of nosocomial and community-acquired infections. Bacterial strain typing, or subspecies identification, has become an important clinical tool for investigating suspected outbreaks and evaluating nosocomial transmission. Adequate and precise typing of S. aureus isolates that permits the monitoring of local outbreaks and wider-scale dissemination of specific dangerous clones is of great concern (1)(2)(3). Similar to typing in other microbial organisms, S. aureus typing has been greatly influenced and improved by molecular techniques. Differences in the various molecular methods used to define different genomic characteristics greatly affect their essential parameters, including discriminatory power and test turnaround time (1)(2)(3). The most important methods currently used for MRSA typing are pulsed-field gel electrophoresis (PFGE) (4)(5)(6)(7), multilocus sequence typing (MLST) (8)(9), spa (staphylococcal surface protein A) typing (1)(6)(10)(11), multilocus variable tandem repeat analysis (MLVA) (12)(13), and repeat-element PCR (rep-PCR) typing (7)(14)(15). These methods have been used to investigate the evolution of the MRSA clones that have emerged since the 1960s and to study their worldwide dissemination. Tremendous progress in molecular-typing methods has been made, with optimization and standardization of sequence-based technologies offering broad applicability and high throughput; however, no single S. aureus typing method has yet provided rapid and reliable information that is sufficient to permit prompt action to control infections. Because S. aureus has a highly clonal population structure, many different chromosomal markers indexing polymorphisms …
Multidimensional MDCT Angiography in the Context of Transcatheter Aortic Valve Implantation

OBJECTIVE. Transcatheter aortic valve implantation has emerged as a viable treatment alternative for patients with severe aortic stenosis who are not surgical candidates. Multidimensional (3D and 4D) MDCT angiography plays a critical role in the safety, success, and outcome of an institutional transcatheter aortic valve implantation program. CONCLUSION. Given the increasing therapeutic role of this innovative technique, an understanding of essential imaging concepts in its context is critical for appropriate image acquisition and interpretation.
The role of inclusion and pore content on the fracture toughness of powder-processed blended elemental titanium alloys

This study examined the effect of the inherent microstructural defects of inclusions and pores on the fracture toughness of powder-processed, blended elemental Ti-6Al-2Sn-4Zr-2Mo, Ti-6A1-4V, Ti-6Al-6V-2Sn, and Ti-10V-2Fe-3Al. These materials had been processed to contain either chloride inclusions or pores or a combination of both types of defects. The fracture toughness values for all of the samples were inversely dependent on the volume fraction of defects. These values also depended on defect type, with toughness values that were significantly higher in material containing only pores than in material containing inclusions or inclusions and pores. In all samples, fracture occurred by microvoid coalescence which initiated at these defects. Quantitative fractography and a ductile fracture toughness model were then combined to further define the relationship between defects, fracture mode, and fracture toughness. This approach showed that the smallest inclusions did not participate in the fracture process. Of the defects that did participate, the approach showed that both chloride inclusions and pores control fracture toughness in all alloys studied through their effects on defect spacing and the amount of void growth to failure. Furthermore, it demonstrated that the only alloy in which the pores and chloride inclusions combined to control fracture toughness was Ti-10V-2Fe-3Al.
Hybridization within the species complex of the scleractinan coral Montastraea annularis

The morphologically variable reef coral previously known as Montastraea annularis (Ellis and Solander, 1786) has recently been separated into three species based on differences in morphology, behavior, allele frequencies and some life-history traits of Panamanian specimens. To further investigate the proposed reclassification and its conformity to the biological species concept we conducted reciprocal intra- and inter- specific fertilization experiments with gametes from each of the three species on Florida reefs. With one exception, self-fertilization rates were very low or zero. Within-species crosses resulted in production of planulae, as did all inter-species (hybrid) crosses, but there was much variation in fertilization success within each type of cross. In an experiment with separated gametes, hybrid crosses between M. annularis and M. franksi produced more larvae than within-species crosses for each species. Hybridization crosses between M. faveolata and the other two species produced fewer larvae than did within- M. faveolata crosses in the experiment with separated gametes, but many larvae resulted when the hybridizations were performed by mixing entire gamete bundles. Additional observations showed that M. franksi had 20% larger eggs and fewer eggs per gamete bundle than did the other two species and that it consistently spawned 1 to 1.5 h before the others, a potential temporal barrier to hybridization. These results indicate that there is no inherent pre-zygotic barrier to cross-fertilization among the three morphological species, although post-zygotic survival and fertility remain to be determined. The adherence of the proposed reclassification to the biological species concept requires further examination.
HMDSO-plasma modification of polypropylene fabrics

Abstract A hexamethyldisiloxane (HMDSO)-RF plasma was used to treat polypropylene (PP) fabrics to achieve an inorganic type surface. The properties of the plasma modified PP were investigated through demand wettability and contact angle techniques. ESCA and ATR-IR spectroscopy indicated the presence of SiOSi and SiOC based structures. The influence of treatment time on the level of deposition and surface atomic composition was established. Plasma induced molecular fragmentation of HMDSO was determined through GC-MS and high resolution MS analyses of the molecular structures produced from recombination of active species, in the cold trap.
Understanding and Manipulating Inorganic Materials with Scanning Probe Microscopes

Scanning probe microscopies, such as scanning tunneling microscopy and atomic force microscopy, are uniquely powerful tools for probing the microscopic properties of surfaces. If these microscopies are used to study low-dimensional materials, from two-dimensional solids such as graphite to zero-dimensional nanostructures, it is possible to elucidate atomic-scale structural and electronic properties characteristic of the bulk of a material and not simply the surface. By combining such measurements with chemical synthesis or direct manipulation it is further possible to elucidate relationships between composition, structure, and physical properties, thus promoting an understanding of the chemical basis of material properties. This article illustrates that the combination of scanning probe microscopies and chemical synthesis has advanced our understanding of charge density waves, high-temperature superconductivity, and nanofabrication in low-dimensional materials. This new approach to studying materials has directly contributed to our knowledge of how metal dopants interact with charge density waves and elucidated the local crystal chemistry of complex copper oxides, microscopic details of the superconducting states in materials with a high superconducting transition Ic, and new approaches to the fabrication of multi-component nanostructures. Coupling scanning probe microscopy measurement and manipulation with chemical synthesis should provide an approach to understanding material properties and creating complex nanostructures in general.
Field Observations of Longitudinal Dispersion in a Run-Of-The-River Impoundment

Abstract Dye studies were conducted on a run-of-the-river impoundment to observe longitudinal dispersion in a lacustrine/riverine environment. Field data were analyzed in the context of a streamtube model which accounts for dispersion by the lateral distribution of longitudinal velocity. The differential advection associated with the vertical distribution of longitudinal velocity [i.e. Elder's equation ( D x = α x u ∗ h )] is incorporated in this stream-tube model providing longitudinal dispersion within each tube. Model calibration attempts required α values on the order of 100, greatly in excess values expected from fluvial experience. A diffusive stall was observed twice when the dye plume moved into a sudden expansion of channel width. The stall is predicted by Fischer's K x equation. The stream-tube model reasonably reproduced the field data in a variety of initial-period conditions, caused by the highly variable geometry of Coralville Reservoir.
Concentration of Inosine 5′‐Monophosphate in Meat

SUMMARY Concentrations of inosine 5′-monophosphate (IMP) were not significantly different in the longissimus dorsi, biceps femoris, and semimembranosus muscles of six pork carcasses sampled 48 hr post-mortem. On aging beef for 28 days at 0.1–1.5°C (33–35°F) the peak concentration of IMP (5.4 μM/g) occurred at 12.hr post-mortem. Other values through the 4th day of post-mortem aging were approximately the same. Following the 4th day, a gradual but steady decline in IMP content was observed until a value of only 0.75 μM/g or less than 15% of the peak IMP concentration remained after 28 days storage. A wide range of IMP concentration was observed between muscles obtained from different species, with beef sampled at 0 hr containing the highest amounts (4.71 μM/g) and pork heart muscle sampled at 0 hr containing the least (0.13 μM/g).
Expression and activity of osteoblast-targeted Cre recombinase transgenes in murine skeletal tissues.

The Cre/loxP recombination system can be used to circumvent many of the limitations of generalized gene ablation in mice. Here we present the development and characterization of transgenic mice in which Cre recombinase has been targeted to cells of the osteoblast lineage with 2.3 kb (Col 2.3-Cre) and 3.6 kb (Col 3.6-Cre) fragments of the rat Col1a1 promoter. Cre mRNA was detected in calvaria and long bone of adult Col 2.3-Cre and Col 3.6-Cre mice, as well as in tendon and skin of Col 3.6-Cre mice. To obtain a historical marking of the temporal and spatial pattern of Cre-mediated gene rearrangement, Col-Cre mice were bred with ROSA26 (R26R) mice in which Cre-mediated excision of a floxed cassette results in LacZ expression. In Col 2.3-Cre;R26R and Col 3.6-Cre;R26R progeny, calvarial and long bone osteoblasts showed intense β-gal staining at embryonic day 18 and postnatal day 5. The spatial pattern of β-gal staining was more restricted in bone and in bone marrow stromal cultures established from Col 2.3-Cre;R26R mice. Similar differences in the spatial patterns of expression were seen in transgenic bone carrying Col1a1-GFP visual reporters. Our data suggest that Col 2.3-Cre and Col 3.6-Cre transgenic mice may be useful for conditional gene targeting in vivo or for obtaining osteoblast populations for in vitro culture in which a gene of interest has been inactivated.
Assessing Usability of Human–Machine Interfaces for Life Science Automation Using Computational Cognitive Models

The objective of this study was to assess the plausibility of using computational cognitive models for evaluating the usability of human–machine interfaces in supervisory control of high-throughput (biological) screening (HTS) operations. Usability evaluations of new interface prototypes were conducted by comparisons with existing technologies. Model assessment occurred through comparison with human test results. Task completion times and the number of errors were recorded during human performance trials, and task time was predicted in cognitive model trials in tests with two HTS interfaces. Computational GOMSL (Goals, Operators, Methods, and Selection rules Language) models were constructed based on a combination of cognitive task analyses (abstraction hierarchy modeling and goal-directed task analysis). The usability tests revealed improvements in task performance with the new prototypes. The cognitive model outputs were correlated with actual human performance, and the approach was considered useful fo...
Polymeric Sulfated Amino Acid Surfactants: A Class of Versatile Chiral Selectors for Micellar Electrokinetic Chromatography (MEKC) and MEKC-MS

In this work, three amino acid-derived (l-leucinol, l-isoleucinol, l-valinol) sulfated chiral surfactants are synthesized and polymerized. These chiral sulfated surfactants are thoroughly characterized to determine critical micelle concentration, aggregation number, polarity, optical rotation, and partial specific volume. For the first time the morphological behavior of polymeric sulfated surfactants is revealed using cryogenic high-resolution electron microscopy. The polysodium N-undecenoyl-l-leucine sulfate shows distinct tubular structure, while polysodium N-undecenoyl-l-valine sulfate also shows tubular morphology but without any distinct order of the tubes. On the other hand, polysodium N-undecenoyl-l-isoleucine sulfate (poly-l-SUCILS) displays random distribution of coiled/curved filaments with heavy association of tightly and loosely bound water. All three polymeric sulfated surfactants are compared for enantioseparation of a broad range of structurally diverse racemic compounds at very acidic, neu...
Attention in performance of a complex skill by retarded children.

Stcmmary.--Try materials were used to train 9 retarded children to attend to differences in colors and shapes of objects, and Frostig worksheets were used to train the children to attend to left-to-right directionality. Evidence suggests Ss' ability to attend to these character~st~cs was generalized to a complex bead-stringing task on which significant gains in performance were found immediately after 15 days of practice with tralnlng materials and after a 6-rno. interval of no further training or practice. Gold and Barclay (1973) have argued persuasively that in tasks involving visual discriminations, intelligence is not related to the ability to make discriminations but rather to the amount of time required in order to identify the problem. Retarded individuals can make the same kinds of visual discriminations as normal individuals; only they have more difficulty in identifying and attending to the relevant aspects of the task. Using principles of attention theory (Zeaman & House, 1963), the difference in lengths of bolts presented in pairs to a group of retarded Ss was gradually reduced until Ss learned to sort accurately bolts differing by only one-eighth of an inch. Ss did not acquire the ability to discriminate on the basis of length; they learned instead that successful mastery of the task required them to attend to these differences. he possibility arises that principles of attention theory might be profitably applied to more complex tasks, and the question is raised as to whether the ability to attend to aspects of a task is generalizable to tasks with similar aspects. The present study was designed to examine both issues.
Effect of verbal aggressiveness on the perceived importance of secondary goals in messages

In face‐to‐face interaction, speakers often pursue secondary goals such as not hurting the other's feelings. Two studies investigated the effect of trait verbal aggressiveness (VA) on the importance of such goals. In both studies, persons higher in VA were relatively less likely to judge messages unacceptable for the reason that the message would offend or hurt the hearer. Study 1 also found that high VAs are less likely to consider messages unacceptable because the message conflicts with their principles and less likely to report chronic secondary goals to be supportive or maintain a positive relationship. In Study 2, the effect of VA on the situated importance of a goal to not offend or hurt the other depended on the situation. The implications for the manner in which high VAs anticipate the outcomes of message are considered.
TCP Nice: a mechanism for background transfers

Many distributed applications can make use of large background transfers - transfers of data that humans are not waiting for -- to improve availability, reliability, latency or consistency. However, given the rapid fluctuations of available network bandwidth and changing resource costs due to technology trends, hand tuning the aggressiveness of background transfers risks (1) complicating applications, (2) being too aggressive and interfering with other applications, and (3) being too timid and not gaining the benefits of background transfers. Our goal is for the operating system to manage network resources in order to provide a simple abstraction of near zero-cost background transfers. Our system, TCP Nice, can provably bound the interference inflicted by background flows on foreground flows in a restricted network model. And our microbenchmarks and case study applications suggest that in practice it interferes little with foreground flows, reaps a large fraction of spare network bandwidth, and simplifies application construction and deployment. For example, in our prefetching case study application, aggressive prefetching improves demand performance by a factor of three when Nice manages resources; but the same prefetching hurts demand performance by a factor of six under standard network congestion control.
Diagnosis and Management of Pleural Effusions: A Practical Approach

Pleural effusion is defined as an abnormal amount of pleural fluid accumulation in the pleural space and is the result of an imbalance between excessive pleural fluid formation and pleural fluid absorption. Although the list of causes of pleural effusions is extensive, the great majority of the cases are caused by pneumonia, congestive heart failure, and malignancy. In this article, we provide an overview of the most common causes of pleural effusions likely to be encountered by the general practitioner, and a practical approach to the diagnosis and management of this common condition.
The last few American Indian treaties¿An extension of the Charles J. Kappler Indian Affairs: Laws and Treaties Internet site at the Oklahoma State University

Abstract In a previous discussion [Bernholz, C.D., & Holcombe, S.L. (2005). The Charles J. Kappler Indian Affairs: Laws and Treaties Internet Site at the Oklahoma State University [The url for this resource is http://www.digital.library.okstate.edu/kappler/]. Library Collections, Acquisitions, and Technical Services; 29, 82–89. An electronic collation of documents created by American Indian tribes and the federal government was presented as an effective collection development resource. That digital work provides the final text of 366 of the 375 American Indian treaties recognized by the United States Department of State. This research note describes an electronic suite that supplies access to the texts of the remaining nine treaties, so that its use – in combination with the Oklahoma State University materials – will furnish an avenue to all of these historical instruments. Research examples, for this document set and in comparison to the Kappler collation, are provided.
A Review of the EDUG Software for Generalizability Analysis

EDUG (Swiss Society for Research in Education Working Group, 2006) is a software package designed to perform generalizability analysis. It was designed by Jean Cardinet, with input from Richard Ber...
Energy migration alters the fluorescence lifetime of Cerulean: implications for fluorescence lifetime imaging Forster resonance energy transfer measurements

Forster resonance energy transfer (FRET) is a physical phenomenon used to study molecular interactions in living cells. Changes in the fluorescence lifetime of proteins genetically tagged with a donor fluorophore, such as cyan fluorescent protein or Cerulean, are used to measure energy transfer to a protein tagged with an acceptor fluorophore (yellow fluorescent protein or Venus). Increased transfer efficiency is usually interpreted as closer proximity. Resonance energy transfer is also possible between identical fluorophores. This form of FRET is called energy migration resonance energy transfer (EM-RET). Theoretically, EM-RET should not alter the lifetime or emission spectrum measured from a population of fluorophores. We find a change in the fluorescent lifetime of Cerulean that correlates with energy migration and can result in significant errors when using Cerulean as a donor to measure fluorescence lifetime imaging (FLIM)-FRET efficiencies.
Pancreatic endocrine tumor EUS-guided FNA DNA microsatellite loss and mortality.

Background The clinical course of pancreatic endocrine tumors (PET) depends on tumor size, the presence of invasion or metastasis, the Ki-67 index, mitoses per high power field, and mutational damage. Most of this information is not available before surgery for clinical decision making or prognostication. Objective To evaluate PET EUS-guided FNA (EUS-FNA) microsatellite loss analysis in the context of PET-related mortality. Design A single institution retrospective cohort. Patients Patients with PET diagnosed by EUS-FNA who underwent DNA microsatellite loss analysis and at least 1 year of follow-up or subsequent death. Intervention PET microsatellite loss analysis results and current clinical status were compared. Results Twenty-nine patients were included in the final analysis; the mean age of the patients was 57 years, and 10 were women (35%). The mean follow-up was 33.7 months (median 30 months, range 2-66 months). Twelve patients had disease progression, and 8 died, all from disease-specific causes. Malignant PET contained multiple microsatellite losses, with a median fractional allelic loss (FAL) of 0.37 (range 0.12-0.69, interquartile range [IQR] 0.23-0.42), significantly different from benign PET, median FAL 0 (range 0-0.18, IQR 0-0.08, P P 0.2 ( P 0.2 and disease status or mortality. Limitations Retrospective design, referral bias, and DNA analysis availability. Conclusions PET EUS-FNA microsatellite loss analysis provides preoperative prognostic information. An FAL >0.2 is not only associated with disease progression but also with mortality.
Initial presentation and recurrence of metastatic rhabdomyosarcoma as breast mass

Rhabdomyosarcoma rarely metastasizes to the breast. We report a case of a pediatric patient who initially presented with a right breast mass and pancytopenia, which was subsequently diagnosed as alveolar rhabdomyosarcoma. Despite initial favorable response to chemotherapy, a new metastatic focus was found in the contralateral breast 10 months later.
DECAY OF 209At TO LEVELS IN 209Po

Abstract The electron-capture decay of 209At has been investigated and present data define twenty-one levels in 209Po. The multipolarities of thirty-six transitions have been deduced and combined with data from recent reaction studies to assign spins and parities to levels. Evidence is presented to identify seniority one and seniority three states below 2.3 MeV which arise from couplings of the one-neutron hole with two-proton configurations. A calculation using experimental data from neighboring isotopes in the lead region to approximate residual interactions was found to give remarkable agreement with the experimental level structure below 1.6 MeV. First-forbidden electron-capture transition rates to even parity levels at 2.3 and 2.9 MeV in 209Po are discussed with reference to the g 9 2 and i 11 2 . seniority one neutron states.
Evaluation of low-phytate corn and barley on broiler chick performance

Grains produced by low-phytate barley and corn isolines homozygous for each species' respective low phytic acid 1-1 allele were compared to grain produced by near-isogenic normal or wild-type barley and corn in broiler chick feeds. Cobb x Cobb (384) chicks were used in a 10-d study. A randomized complete block design with a factorial arrangement of 2 x 2 x 3 was used with 4 replicates (8 chicks / replicate) per treatment. Twelve isocaloric and isonitrogenous treatment diets were formulated to contain 2 types of grain (barley and corn), 2 levels of grain (40% and 60%), and 3 sources of available P (wild-type grain, wild-type P-supplemented grain, and low-phytate grain). Growth parameters, bone parameters, total bone mineral, and apparent digestibilities were measured. The mean growth and bone responses were 1) higher for barley diets compared to corn diets, 2) higher for 60% grain inclusion compared to 40%, 3) higher for low-phytate compared to wild-type grains, and 4) not different for low-phytate compared to P-supplemented wild-type grain diets. Chicks fed low-phytate-based diets excreted 33 and 43% less P than chicks fed wild-type and P-supplemented wild-type diets, respectively. Correlations between percentage bone ash, total bone ash, and bone strength indicated a strong relationship and appear to support the use of bone strength analysis as a simpler method than ash content determination as an indication of P status. Feeding low-phytate grains will reduce the need for supplemental P in chick diets.
Utilization of Dual Phase Gas Diffusion FIA with a Mass Spectrometer as a Detector

Abstract The coupling of dual phase gas diffusion flow injection analysis with mass spectrometry has been shown to be feasible. This combined technique offers a high degree of selectivity and sensitivity. This technique was developed to determine whether volatile mixed arsenic selenium hydrides are formed in dual phase gas diffusion flow injection analysis hydride generation.
Formation and regeneration of protoplasts of wild-typeNeurospora crassa

Trichoderma reesei was grown using purified cell walls ofNeurospora crassa as a primary source of carbon. The resulting culture medium contained an undefined mixture ofN. crassa cell-wall digesting enzymes. Protoplasts (cell lacking wall) were formed when youngN. crassa hyphae were treated withTrichoderma mixture. The vast majority of protoplasts resynthesized cell-wall material when washed free of cell-wall digesting enzyme; of these, about 40% regenerated a mycelium.
Calcium and hydrogen ion concentrations in the parasitophorous vacuoles of epithelial cells infected with the microsporidian Encephalitozoon hellem.

Microsporidia of the genus Encephalitozoon undergo merogony and sporogony in a parasitophorous vacuole within the host cell. Cultured green monkey kidney cells infected with Encephalitozoon hellem were loaded with the fluorescent dyes fura-2 or BCECF in order to measure intracellular concentrations of calcium and hydrogen ions respectively. Both the parasitophorous vacuole calcium concentration and pH values resembled those of the host cell cytoplasm in infected cells. Calcein entered the parasitophorous vacuole but not other host cell vacuoles or parasite stages within the parasitophorous vacuole. The lack ofa pH or calcium concentration gradient across the parasitophorous vacuole membrane and the permeability of this membrane to a large anion such as calcein suggest that the vacuole membrane surrounding E. hellem resembles that surrounding some other intracellular parasites such as Toxoplasma gondii. A potential role is discussed for the parasitophorous vacuole calcium concentration in germination in situ.
The photo-peroxidation of unsaturated organic molecules. O21Δg-acceptor re-encounter probabilities

Abstract A previous report to the effect that the self-sensitised photo-peroxidation of 1,3-diphenylisobenzofuran in solution proceeds at a rate which is independent of acceptor concentration when this is very low, has been confirmed and interpreted in terms of a re-encounter of O 2 1 Δ g and ground state acceptor molecules generated in the same triplet-triplet annihilation act. The overall re-encounter probability (with or without reaction) is found to be 0.61 in agreement with theoretical predictions and with values obtained from a similar treatment of the excimer/molecular intensity ratio in the delayed fluorescence spectrum of pyrene and other organic fluors. This interpretation also affords a quantitative explanation of the failure of tetramethylethylene to inhibit the reaction completely and eliminates the necessity to invoke the spin-forbidden direct addition of O 2 3 Σ g − to the excited singlet state of the acceptor.
ON AN EFFICIENT SPARSE REPRESENTATION OF OBJECTS OF GENERAL SHAPE VIA CONTINUOUS EXTENSION AND WAVELET APPROXIMATION

In this paper, we discuss the continuous extension and wavelet approximation of the detected object on a general domain Ω of ℝ2. We first extend continuously the image to a square T such that it vanishes on the boundary ∂T. On T∖Ω, the extension has a simple and clear representation which is determined by the equation of the boundary ∂Ω. We expand the extension into wavelet series on ℝ2. Since the extension tools are polynomials, by the moment theorem, we know that the sequence of wavelet coefficients obtained by us is sparse. Therefore, we can approximate and analyze the internal information of the object very well even if we only store a few wavelet coefficients.
3 μm GaSb-based type-i quantum-well diode lasers with cascade pumping scheme

GaSb-based type-I quantum-well diode lasers with two-cascade active region were designed and fabricated. The injection is achieved by means of tunnel junction between AlGaAsSb graded composition and InAs/AlSb chirped superlattice layers. The devices operate in continuous wave regime at room temperature and demonstrate twofold improvement of injection efficiency as compared to reference single cascade lasers.
Proton electron double resonance imaging (PEDRI) of the isolated beating rat heart.

Proton electron double resonance imaging (PEDRI) is a double resonance technique where proton MRI is performed with irradiation of a paramagnetic solute. A low-field PEDRI system was developed at 20.1 mT suitable for imaging free radicals in biological samples. With a new small dual resonator, PEDRI was applied to image nitroxide free radicals in isolated beating rat hearts. Experiments with phantoms showed maximum image enhancement factors (IEF) of 42 or 28 with TEMPONE radical concentrations of 2-3 mM at EPR irradiation powers of 12W or 6W, respectively. In the latter case, image resolution better than 0.5 mm and radical sensitivity of 5 microM was obtained. For isolated heart studies, EPR irradiation power of 6W provided optimal compromise of modest sample heating with good SNR. Only a small increase in temperature of about 1 degrees C was observed, while cardiac function remained within 10% of control values. With infusion of 3 mM TEMPONE an IEF of 15 was observed enabling 2D or 3D images to be obtained in 27 sec or 4.5 min, respectively. These images visualized the change in radical distribution within the heart during infusion and clearance. Thus, PEDRI enables rapid and high-quality imaging of free radical uptake and clearance in perfused hearts and provides a useful technique for studying cardiac radical metabolism.
Highly Incident Configurations with Chiral Symmetry

A geometric $$k$$ -configuration is a collection of points and straight lines in the plane so that $$k$$ points lie on each line and $$k$$ lines pass through this point. We introduce a new construction method for constructing $$k$$ -configurations with non-trivial dihedral or chiral (i.e., purely rotational) symmetry, for any $$k \ge 3$$ ; the configurations produced have $$2^{k-2}$$ symmetry classes of points and lines. The construction method produces the only known infinite class of symmetric geometric 7-configurations, the second known infinite class of symmetric geometric 6-configurations, and the only known 6-configurations with chiral symmetry.
2,6-Bis(pyren-1-oyl)pyridine : a new fluorescent probe with a high sensitivity to hydrogen-bonding solvents for the development of selective sensors

Abstract New probes 2,6-bis(pyren-1-oyl)pyridine ( 1 ) and 1,3-bis(pyren-1-oyl)benzene ( 2 ) with pyrenoyl moieties attached to a six-membered ring spacer, were synthesized. The presence of a single nitrogen atom in the spacer of 1 seems to be responsible for the sensitivity of its fluorescence towards hydrogen-bonding solvents and quenchers. The flourescence emission maxima of 1 and 2 decrease dramatically with solvent polarity parameter E T (30), but their absorption spectra show no sensitivity. In the case of 1 , the color of fluorescence changes from blue in cyclohexane to orange—red in acetonitrile. Although the fluorescence energies of 1 and 2 decrease with increased solvent polarity, their relative fluorescence yields show a more complex dependence on solvent polarity. The fluorescence yield of 1 decreases monotonically with polarity, while 2 has a maximum value in anisole. In addition, hydrogen-bonding solvents quench the emission from 1 very strongly, whereas 2 shows no such sensitivity for protic solvents. Aniline, phenol and water quench the emission from 1 with quenching constants of 12, 4.6 and 2.2 M −1 respectively, whereas the corresponding quenching constants for 2 are 9.5, 3.5 and 0.27 M −1 . A large deuterium isotope effect was observed for the fluorescence quenching of 1 by water ( K SV H 2 O/ K SV D 2 O = 1.7). In non-polar solvents, hydrogen-bonding quenchers, such a phenol and aniline, quench the emission of 1 much more efficiently than anisole, a non-hydrogen-bonding quencher. From a comparison of the fluorescence quenching characteristics of 1 and 2 by hydrogen-bonding and non-hydrogen-bonding quenchers, it can be concluded that hydrogen bonding plays a key role in the quenching of the excited state of 1 . In contrast, the carbon analog 2 shows no such discrimination between hydrogen-bonding and non-hydrogen-bonding quenchers. Therefore, the single nitrogen atom present in 1 is important in determining the photophysical properties of 1 and perhaps provides a hydrogen-bonding acceptor site. The high sensitivity of the fluorescence of 1 towards solvent polarity, as well as the hydrogen-bonding ability of the solvents, makes 1 an attractive candidate for the design of highly selective fluorescence sensors.
Alterations in spinal cord norepinephrine levels following experimentally produced trauma in normal and adrenalectomized cats

Abstract Spinal cords of normal and adrenalectomized cats were subjected to experimentally produced blunt trauma and then analyzed for changes in concentration of norepinephrine (NE). In normal cats the NE concentrations at the lesion site rose 63% over control after one hour, and by 1 1 2 to 2 hours had returned to control level. Little change in concentration was observed in cord segments 2 cm from injury site, but segments adjacent to the injury exhibited increased levels of NE. NE concentrations one hour after trauma in adrenalectomized cats were lower than those measured in normal controls. It is postulated that the mechanism of NE accumulation involves a breakdown of the blood-spinal cord barrier thereby allowing peripherally produced NE to enter the cord parenchyma from the systemic circulation.
Quantitative comparison of dipole models for steady-state currents in excitable membranes.

The dipole models for steady-state currents in excitable membranes of Arndt, Bond and Roper and of Hamel and Zimmerman are compared by fitting the equations to the data of Gilbert and Ehrenstein. The more complex Hammel and Zimmerman model does not fit the data as well as does the simpler Arndt, Bond and Reper model. When fitting the data, the Hammel and Zimmerman current equation reduces to the Arndt, Bond and Roper current equation because of the values assumed by the parameters. An interpretation is given for the parameter values obtained with the Arndt, Bond and Roper model.
Too Much of a Good Thing: Blocking Noradrenergic Facilitation in Medial Prefrontal Cortex Prevents the Detrimental Effects of Chronic Stress on Cognition

Cognitive impairments associated with dysfunction of the medial prefrontal cortex (mPFC) are prominent in stress-related psychiatric disorders. We have shown that enhancing noradrenergic tone acutely in the rat mPFC facilitated extra-dimensional (ED) set-shifting on the attentional set-shifting test (AST), whereas chronic unpredictable stress (CUS) impaired ED. In this study, we tested the hypothesis that the acute facilitatory effect of norepinephrine (NE) in mPFC becomes detrimental when activated repeatedly during CUS. Using microdialysis, we showed that the release of NE evoked in mPFC by acute stress was unchanged at the end of CUS treatment. Thus, to then determine if repeated elicitation of this NE activity in mPFC during CUS may have contributed to the ED deficit, we infused a cocktail of α1-, β1-, and β2-adrenergic receptor antagonists into the mPFC prior to each CUS session, then tested animals drug free on the AST. Antagonist treatment prevented the CUS-induced ED deficit, suggesting that NE signaling during CUS compromised mPFC function. We confirmed that this was not attributable to sensitization of adrenergic receptor function following chronic antagonist treatment, by administering an additional microinjection into the mPFC immediately prior to ED testing. Acute antagonist treatment did not reverse the beneficial effects of chronic drug treatment during CUS, nor have any effect on baseline ED performance in chronic vehicle controls. Thus, we conclude that blockade of noradrenergic receptors in mPFC protected against the detrimental cognitive effects of CUS, and that repeated elicitation of noradrenergic facilitatory activity is one mechanism by which chronic stress may promote mPFC cognitive dysfunction.
The regulation of alcohol intake by melanin-concentrating hormone in rats.

Abstract Given into the brain, melanin-concentrating hormone (MCH) increases alcohol consumption, but the mechanism and physiological relevance of this effect are unclear. We hypothesized that endogenous MCH will enhance alcohol drinking and that MCH increases alcohol's reinforcing properties. An MCH receptor 1 (MCHR1) antagonist, or saline was administered centrally alone, or preceding MCH or saline to rats trained to drink 10% alcohol using sucrose fading. Blocking MCHR1 neither reduced alcohol intake (saline = 0.4 ± 0.1 g, 30 μg MCHR1 antagonist = 0.4 ± 0.1 g/kg alcohol), nor attenuated MCH-induced alcohol drinking (MCHR1 antagonist/saline = 0.7 ± 0.1 g/kg, MCHR1 antagonist/MCH = 0.9 ± 0.1 g/kg alcohol). Another cohort of rats was trained to lever press for alcohol on a progressive ratio schedule. MCH or saline was administered centrally and lever presses were measured. MCH had no effect prior to the break point, but increased total responding during the session (saline = 87.2 ± 32.0, MCH = 315.4 ± 61.0 presses). In conclusion, these data suggest that MCH augments alcohol drinking partly by enhancing the drug's reinforcing value. Further, endogenous MCH does not seem to regulate alcohol drinking, however because the antagonist failed to attenuate MCH-induced alcohol intake this conclusion is tentative.
Experimental verification of the shear-induced hydrodynamic diffusion model of crossflow microfiltration

Abstract Two series of experiments were conducted to determine the validity of the shear-induced diffusion model of crossflow microfiltration (Romero and Davis, 1988, 1990 ). In one series, a rectangular glass-walled crossflow microfilter was used under conditions for which a thick stagnant particle layer formed against the membrane with negligible flux decline. Measurements of the particle layer thickness profiles at steady state agree reasonably well with the predictions of the theory. In particular, the layer thickens with increased particle concentration, increased transmembrane pressure drop, and decreased shear rate. Initial rates of the particle layer buildup in the rectangular microfilter are also in good agreement with theoretical predictions, which are essentially the same as those for dead-end filtration. In the second series of experiments, a commercial tube-bundle was used under conditions for which a moderate flux decline occurred. Computer-aided data collection permitted rapid and accurate measurements of permeate flux. The transient and steady-state flux responses under varying operating conditions agree with the theoretically predicted responses, with application of the Blake—Kozeny correlation for the specific cake resistance as a function of particle size.
Circadian changes in the distribution and effects of haloperidol in the rat

Striking circadian changes in behavioral sensitivity to haloperidol were found by measurements of cataleptic responses in rats trained in a controlled lighting cycle (lights on, 7:00 a.m.–7:00 p.m.). Thus, catalepsy was maximal at about 4:00 p.m. and minimal at about 4:00 a.m., virtually the opposite of the circadian rhythm of spontaneous behavioral activity in drug-free rats. At a given dose of haloperidol, catalepsy scores differed 2- to 3-fold, and the ED50 shifted left nearly 10-fold from a.m. to p.m. After fixed doses of haloperidol, tissue levels of the drug, as determined by a sensitive and selective radioreceptor assay, differed by 2- to 6-fold through the 24 hr cycle and brain levels closely followed the circadian changes in behavior. These results suggest a pharmacokinetic contribution to the circadian changes in behavioral response, although additional pharmacodynamic factors are also considered.
Transcription of non-repeated DNA in Neurospora crassa.

Abstract Repeated and non-repeated DNAs of Neurospora crassa mycelial cells were fractionated by hydroxyapatite chromatography and characterized separately for reassociation kinetics and thermal stability profiles of reassociated DNAs. Approx. 90 % of N. crassa DNA sequences reassociated like single-copy DNA. About 35 % of these unique sequences were found to be transcribed in mid-log phase of mycelial growth when measured by DNA · RNA hybridization at a RNA C 0 t of about 90 000.
PRESENCE OF THE SRY GENE IN DISORDERS OF SEXUAL DIFFERENTIATION

Identification of Y chromosomal material is important in individuals wilh disorders of sexual differentiation because 1) an increased risk for gonadal neoplasms exists and 2) insight into the process of sexual differentiation may be augmented. To better understand the role of SRY in disorders of sexual differentiation, tissues from 4 individuals were assessed by SRY specific PCR and Southern blotting with an SRY probe. Key: TH=true hermaphroditisrn, MGD=mixed gonadal dysgenesis, ot=ovotestis, os=ovarian stroma, NA=not available, PBL=peripheral blood leukocyte The sensitivity of this probe which can easily detect 1:10,000 cells indicates that mosaictsrn for the SRY portion of the Y chromosome has occurred in patients 1 & 3. For patients with Turner's syndrome, addilional investigation of such patients is needed to determine the frequency of this mosaicism. For patient 3, the finding of SRY gene correlates with the observed testicular differentiation and virilization. For patient 2, further evaluation of the function of SRY and additional genes involved in sexual differentiation is necessary.
Non Diffusive Mobility of Solid Hydrogen Films

We have used a “hole-burning” technique to study the mobility of thin solid films of H2 and D2 for temperatures between 1.6 K and 5 K. Even at low temperatures where transport through the vapor is negligible, the solid films remain mobile. The transport is thermally activated with an activation energy of 19 K for H2 and 38 K for D2. The time dependence of the regrowth shows that surface transport is not due to simple diffusion.
Electrochemical oligonucleotide detection based on probe DNA-modified gold electrode using cobalt phenanthroline complex

Electrochemical detection of specific DNA sequence was investigated by using a gold electrode immobilized with probe DNA and tris(1, 10-phenanthroline) cobalt (II) complex (Co(phen)32+) as a hybridization indicator. 25-mer probe DNA modified with a thiol group at 5' end was immobilized on a gold electrode. After the probe DNA-modified gold electrode was hybridized with complementary target DNA, the anodic peak current of 0.1mM Co(phen)32+ increased as to the concentration of target DNA in the range from 10-7M to 10-4M. On the other hand, no current increase was observed when it was hybridized with poly-deoxy A as non-complementary DNA in the same range of concentration.
Comparison of Existing Responsiveness-To-Intervention Models to Identify and Answer Implementation Questions

Responsiveness-to-intervention (RTI) is the front-running candidate to replace current practice in diagnosing learning disabilities, but researchers have identified several questions about implementation. Specific questions include: Are there validated intervention models? Are there adequately trained personnel? What leadership is needed? When does due process protection begin? and Is RTI a defensible endpoint in the identification process? These questions were addressed by examining four existing large-scale RTI models, Heartland Model (Iowa), Intervention-Based Assessment (Ohio), Instructional Support Teams (Pennsylvania), and the ProblemSolving Model in Minneapolis (Minnesota) Public Schools. The RTI process led to positive outcomes for children with and without disabilities, but all four models were phased-in over time, relied on extensive training for a multidisciplinary team, and followed a protocol to develop data-based adaptations. Clarification about team membership, leadership, and initiation of due process is still required. Additional questions about RTI were generated regarding students in secondary grades, parental involvement, and fidelity of implementing. Recommendations for implementation are included.