cssi/SciSciGPT-SciSciNet huggingface dataset:
SLIDE-AWAY DISTRIBUTIONS AND RELEVANT COLLECTIVE MODES IN HIGH-TEMPERATURE PLASMAS

The evolution of the electron distribution function, when an electric field that is not too small in comparison with the critical electron runaway field is applied along the confining magnetic field of a high temperature plasma, is analysed. In the regimes considered, a finite fraction of the electron population has magnetically trapped orbits, and is not appreciably affected by the applied electric field, while the distribution of circulating electrons tends to "slide away" as a whole. Then the Spitzer-Harm model for the current-carrying electron distribution is inadequate, and the role that collective modes, in particular current-driven microinstabilities, and collisions can play in producing a stationary electron distribution is analysed. Modes at the ion plasma frequency, ωpi, that are driven by the positive slope of the current-carrying electron distribution, can be excited, when the average electron drift velocity is a finite fraction of the electron thermal velocity, and transfer transverse energy to the main body of the electron distribution. These features are consistent with the experimental observations performed on the Alcator device. Modes at the "reduced" electron plasma frequency (k||/k)ωpe can also be excited both in connection with the modes at ωpi and independently. Modes at the electron gyrofrequency Ωe associated with the loss-cone feature that the electron distribution tends to develop are considered, among others, as a factor for the strongly enhanced electron cyclotron emission experimentally observed in regimes where non-thermal electron distributions have been realized.
Leptonic Decays of Hyperons

Au event was found in the film taken in the course of atically seperated K- beam was passed into the Berkeley 15-inch hydrogen bubble chamber which was interpreted to be a beta decay of a lambda hyperon. It was consluded that a LAMBDA produced by the K/sup -/ decayed via the process ation for is given. (W.D.M.)
The day‐to‐day variability in ionospheric electric fields and currents

The daily variations in ionospheric drift velocities are examined from incoherent scatter measurements at Millstone Hill. The data with summed Kp greater than 24 behave differently from those with low magnetic activity and basically follow the convection pattern but have large day-to-day variations. The influence of the magnetic conjugate point is discussed, and solar cycle variations are examined in conjunction with geomagnetic variations. Ionospheric currents calculated by using a semidiurnal neutral wind model are in good agreement with ground-based magnetograms for low magnetic activity, but the E region neutral wind model appears to be applicable only to this case.
Controlled reperfusion prevents pulmonary injury after 24 hours of lung preservation

Abstract Background . Posttransplantation lung reperfusion injury continues to be a major problem. We have shown that controlling the initial period of reperfusion limits this injury after 2 hours of warm lung ischemia. The effectiveness of this modality, however, is unknown after longer periods of cold ischemia, which more closely mimics the clinical situation. Methods . After baseline measurements, 10 pigs had the left lung flushed with a modified Euro-Collins solution, explanted, stored at 4°C for 24 hours, and transplanted into 10 other pigs. Five (group 1) underwent uncontrolled reperfusion created by removal of the vascular clamps after implantation of the new left lung, mimicking the clinical situation. The other five (group 2) underwent controlled reperfusion, which we performed by taking blood from the femoral artery, mixing it with a crystalloid solution (using a mixer heater) to make the blood hyperosmolar, alkalotic, and substrate-enriched, and pumping it through a leukocyte-depleting filter into the transplanted lung for 10 minutes at a pressure of 20 to 30 mm Hg before removing the pulmonary artery clamp. The right pulmonary artery and bronchus were then ligated, and left lung function was assessed each hour for 4 hours and compared with baseline. Results . Controlled reperfusion (group 2) minimized the reperfusion injury, preserving posttransplant pulmonary compliance (92% ± 1% versus 68% ± 1%; p p 2 , 425 ± 14 versus 82 ± 11 mm Hg; p p p Conclusions . After 24 hours of cold ischemia uncontrolled reperfusion results in a severe pulmonary reperfusion injury. This injury is almost completely avoided by controlling the composition (modified solution and white blood cell filter) and conditions (pressure) of the reperfusion. Because this experiment mimics the clinical situation, it suggests surgeons should begin to use this modality to limit reperfusion injury after lung transplantation.
Inhibition of sialyltransferase activity in cultured cells by a natural inhibitor from rat brain

Brain from mature rats has been shown previously to contain a natural inhibitor of rat brain sialyltransferase I (CMP-sialic acid: lactosylceramide sialyltransferase activity). This same inhibitor preparation was effective against sialyltransferase I and a second sialyltransferase activity from different lines of cultured cells. Cardiolipin which stimulates sialyltransferase I activity in cultured cells apparently was not required for inhibition. Inhibition was specific for sialyltransferase activities while a third ganglioside biosynthetic enzyme, UDP-gal: glucosyl-ceramide galactosyltransferase activity, was not inhibited. Inhibition of sialyltransferase I was linear with time, heat-resistant, and increased with inhibitor concentration.
A NOVEL METHOD FOR PREPARING SMALL PARTICULATE RADIOACTIVE SOURCES OF HIGH INTENSITY FROM ATTAPULGITE CLAY

Abstract A novel method of preparing small, particulate, radioactive sources of high intensity from attapulgite clay is described. Non-encapsulated sources of this type would probably be suitable for flow-type reaction systems for radiation synthesis. In such systems, maximum efficiency of the radiation could be achieved and combined heterogeneous catalysis-radiation from the same material could be utilized.
Functions of Vitamin D, Retinoic Acid, and Dexamethasone in Mouse Adipose-Derived Mesenchymal Cells

Adipose-derived mesenchymal cells (AMCs) offer great promise for tissue engineering of bone. Previously, 1,25-dihydroxyvitamin D3, retinoic acid (RA), and dexamethasone had been shown to promote osteogenesis in bone marrow-derived mesenchymal cells (BMSCs). To study the osteogenic characteristics of mouse AMCs, we applied these 3 hormones alone and in combination to the AMCs and examined markers of osteogenic differentiation. Interestingly, vitamin D and RA demonstrated a consistent, dose-dependent enhancement of osteogenesis and upregulated osteoblast specific markers including osteopontin and osteocalcin. However, in AMCs, dexamethasone clearly inhibited osteogenic differentiation in a dose dependent fashion and greatly increased the adipogenic marker peroxisome proliferator activated receptor gamma (PPAgamma). In summary, we show in vitro that vitamin D and RA are potential candidates to serve as enhancers of osteogenesis of AMCs and may be incorporated into future cell-based strategies for bone tissue engineering.
HLA epitope based matching for transplantation

As important risk factors for transplant rejection and failure, HLA antibodies are now recognized as being specific for epitopes which can be defined structurally with amino acid differences between HLA alleles. Donor-recipient compatibility should therefore be assessed at the epitope rather than the antigen level. HLAMatchmaker is a computer algorithm that considers each HLA antigen as a series of small configurations of polymorphic residues referred to as eplets as essential components of HLA epitopes. It includes epitopes on antigens encoded by all HLA-A, B, C, DR, DQ and DP loci as well as MICA. HLA epitopes have two characteristics namely antigenicity, i.e. the reactivity with antibody and immunogenicity, i.e. the ability of eliciting an antibody response. This article addresses the relevance of determining epitope-specificities of HLA antibodies, the effect of epitope structure on technique-dependent antibody reactivity and the identification of acceptable mismatches for sensitized patients considered for transplantation. Permissible mismatching for non-sensitized patients aimed to prevent or reduce HLA antibody responses could consider epitope loads of mismatched antigens and the recently developed nonself-self paradigm of epitope immunogenicity.
Physical Properties of Gas Hydrates: A Review

Methane gas hydrates in sediments have been studied by several investigators as a possible future energy resource. Recent hydrate reserves have been estimated at approximately of methane gas worldwide at standard temperature and pressure conditions. In situ dissociation of natural gas hydrate is necessary in order to commercially exploit the resource from the natural-gas-hydrate-bearing sediment. The presence of gas hydrates in sediments dramatically alters some of the normal physical properties of the sediment. These changes can be detected by field measurements and by down-hole logs. An understanding of the physical properties of hydrate-bearing sediments is necessary for interpretation of geophysical data collected in field settings, borehole, and slope stability analyses; reservoir simulation; and production models. This work reviews information available in literature related to the physical properties of sediments containing gas hydrates. A brief review of the physical properties of bulk gas hydrates is included. Detection methods, morphology, and relevant physical properties of gas-hydrate-bearing sediments are also discussed.
Tidal drainage in the treatment of acute uncomplicated empyema in children

Summary A method of treatment of acute empyema is described in detail. Seven consecutive cases treated successfully by this method are reported.
Effect of surgeon training, specialization, and experience on outcomes for cancer surgery: a systematic review of the literature.

Background Outcomes after cancer resections have been shown to be better for high-volume surgeons compared with low-volume surgeons; however, reasons for this relationship have been difficult to identify. The objective of this study was to assess studies examining the effect of surgeon training and experience on outcomes in surgical oncology.
Tonic convulsions induced in mice by vaccinia virus and their prevention by heated influenza virus.

SummaryThe reported experiments have demonstrated that: (1) various strains of vaccinia virus after intracerebral injection regularly produced tonic convulsions in mice; (2) at least one of these strains (NYBH) multiplied extensively in the brains of the mice; (3) mice were protected from the tonic convulsions and death caused by intracerebral injections of vaccinia virus, if they had recived a prior injection of either heated influenza virus or heated vaccinia virus.
A self oscillating class D audio amplifier with 0.0012% THD+N and 116.5 dB dynamic range

A low distortion third-order self-oscillating class D audio amplifier is integrated in a 0.7-µm CMOS process. It can deliver 1.4 W into an 8 Ω load with 5 V power supply. The presented amplifier eliminates the requirement for a high quality carrier. It achieves a dynamic range (DR) of 116.5 dB, and a peak THD+N of 0.0012% for a 1 kHz sinusoidal input. The efficiency is 84.5%. The area of the amplifier is 6 mm2.
Conjugated Antisense Oligonucleotides

Abstract We have employed chemical modification strategies to improve cellular ahsorption of oligonucleotides. These include the conjugation of various pendant moieties to the oligonucleotide to affect its overall physical properties such as hydrophobicity, charge, and amphipathicity as well as pendants that may mediate absorption by binding to certain cellular receptors which internalize specific ligands. Our laboratory has prepared polyamines, polyethylene glycols and lipidic constituents conjugated to oligonucleotidcs in order to study their effects in enhancing absorption of antisense agents. These conjugates were targeted against human or murine Intercellular Adhesion Molecule- 1 (ICAM-1) mRNA.
The influence of some cembranolides from gorgonian corals on motility of marine flagellates

Abstract Crassin acetate, eunicin and eupalmerin acetate, three cembranolides (14-member ring diterpenoid lactones) derived from Caribbean gorgonians, were tested for their effect on a variety of marine flagellates. Included were three isolates of the genus Symbiodinium whose nonmotile forms occur as symbiotic zooxanthellae in coral reef organisms. Eunicin at a concentration of 5 ppm in seawater immobilized most of the flagellates tested. At 10 ppm eucinin immobilized in 10 min three organisms not affected within 24 h at 5 ppm. Crassin acetate and eupalmerin acetate were found active in limited testing.
Staging and Restaging of Breast Cancer Using FDG-PET and PET/CT

Since the introduction of 18 -F-fluorodeoxyglucose positron emission tomography (FDG-PET) to clinical oncologic imaging, studies have examined potential uses of the modality in the evaluation of breast cancer, including primary detection, initial staging, restaging, monitoring response to therapy, and predicting clinical prognosis. Although axillary lymph node staging using FDG-PET remains controversial, numerous studies have established a role for FDG-PET imaging in detecting locoregional recurrence and distant metastases. Furthermore, quantitative analysis of FDG uptake has been investigated as a potential tool for predicting the biological behavior of the tumor and inferring clinical prognosis. The recent introduction of combined positron emission tomography/x-ray computed tomography (PET/CT) systems has shown promise in improving the accuracy of PET imaging and potentially obviating the need for performing additional cross-sectional imaging in cases of suspected distant metastases.
A procedure for blending manual and correlation-based synoptic classifications

Manual and correlation-based (also known as Lund or Kirchhofer) classifications are important to synoptic climatology, but both have significant drawbacks. Manual classifications are inherently subjective and labour intensive, whereas correlation-based classifications give the investigator little control over the map-patterns generated by the computer. This paper develops a simple procedure that combines these two classification methods, thereby minimizing these weaknesses. The hybrid procedure utilizes a relatively short-term manual classification to generate composite pressure surfaces, which are then used as seeds in a long-term correlation-based computer classification. Overall, the results show that the hybrid classification reproduces the manual classification while optimizing speed, objectivity and investigator control, thus suggesting that the hybrid procedure is superior to the manual or correlation classifications as they are currently used. More specifically, the results demonstrate little difference between the hybrid procedure and the original manual classification at monthly and longer time-scales, with less internal variation in the hybrid types than in the subjective categories. However, the two classifications showed substantial differences at the daily level, not because of poor performance by the hybrid procedure, but because of errors introduced by the subjectivity of the manual classification. © 1997 Royal Meteorological Society. Int.J.Climatol., Vol.17, 1381-1396 (No. of Figures: 9 No. of Tables: 1 No. of References: 30)
Together yet separate: Students’ associating amounts of change in quantities involved in rate of change

This paper extends work about quantitative reasoning related to covarying quantities involved in rate of change. It reports a multiple case study of three students’ reasoning about quantities involved in rate of change when working on tasks incorporating multiple representations of covarying quantities. When interpreting relationships between associated amounts, students identified sections (e.g., an interval on a graph) in which they could make comparisons between amounts of change in quantities. Although such reasoning is useful for interpreting a Cartesian graph as a representation of covarying quantities, it does not foster attention to variation in the intensity of change in covarying quantities (e.g., a decreasing increase). Focusing on the kinds of relationships students make between amounts of change in covarying quantities might provide further insight into how students could develop a robust understanding of rate of change.
Calcium and calmodulin regulate mercury-induced phospholipase D activation in vascular endothelial cells.

Earlier, we reported that mercury, the environmental risk factor for cardiovascular diseases, activates vascular endothelial cell (EC) phospholipase D (PLD). Here, we report the novel and significant finding that calcium and calmodulin regulated mercury-induced PLD activation in bovine pulmonary artery ECs (BPAECs). Mercury (mercury chloride, 25 μM; thimerosal, 25 μM; methylmercury, 10 μM) significantly activated PLD in BPAECs. Calcium chelating agents and calcium depletion of the medium completely attenuated the mercury-induced PLD activation in ECs. Calmodulin inhibitors significantly attenuated mercury-induced PLD activation in BPAECs. Despite the absence of L-type calcium channels in ECs, nifedipine, nimodipine, and diltiazem significantly attenuated mercury-induced PLD activation and cytotoxicity in BPAECs. This study demonstrated the importance of calcium and calmodulin in the regulation of mercury-induced PLD activation and the protective action of L-type calcium channel blockers against mercury cy...
Yes-associated protein 65 (YAP) expands neural progenitors and regulates pax3 expression in the neural plate border zone

Yes-associated protein 65 (YAP) contains multiple protein-protein interaction domains and functions as both a transcriptional co-activator and as a scaffolding protein. Mouse embryos lacking YAP did not survive past embryonic day 8.5 and showed signs of defective yolk sac vasculogenesis, chorioallantoic fusion, and anterior-posterior (A-P) axis elongation. Given that the YAP knockout mouse defects might be due in part to nutritional deficiencies, we sought to better characterize a role for YAP during early development using embryos that develop externally. YAP morpholino (MO)-mediated loss-of-function in both frog and fish resulted in incomplete epiboly at gastrulation and impaired axis formation, similar to the mouse phenotype. In frog, germ layer specific genes were expressed, but they were temporally delayed. YAP MO-mediated partial knockdown in frog allowed a shortened axis to form. YAP gain-of-function in Xenopus expanded the progenitor populations in the neural plate (sox2+) and neural plate border zone (pax3+), while inhibiting the expression of later markers of tissues derived from the neural plate border zone (neural crest, pre-placodal ectoderm, hatching gland), as well as epidermis and somitic muscle. YAP directly regulates pax3 expression via association with TEAD1 (N-TEF) at a highly conserved, previously undescribed, TEAD-binding site within the 5′ regulatory region of pax3. Structure/function analyses revealed that the PDZ-binding motif of YAP contributes to the inhibition of epidermal and somitic muscle differentiation, but a complete, intact YAP protein is required for expansion of the neural plate and neural plate border zone progenitor pools. These results provide a thorough analysis of YAP mediated gene expression changes in loss- and gain-of-function experiments. Furthermore, this is the first report to use YAP structure-function analyzes to determine which portion of YAP is involved in specific gene expression changes and the first to show direct in vivo evidence of YAP's role in regulating pax3 neural crest expression.
FastAD: an authenticated directory for billions of objects

We develop techniques that make authenticated directories efficient and scalable toward the goal of managing tens of billions of objects in a single directory. Internet storage services have already realized this scale: Amazon's S3 contained more than 52 billion objects as of April 2009 [1]. Our contributions include defining on-disk, block-oriented data structures and algorithms for authenticated directories that exceed memory capacity and optimizations that reduce the I/O required to insert and access entries in the directory.
The effect of morphine on the content of serotonin, 5-hydroxyindole acetic acid and substance-P in the nuclei raphe magnus and reticularis gigantocellularis.

Abstract The content of serotonin (5-HT), 5-hydroxyindole-3-acetic acid (5-HIAA) and substance-P (SP) in nucleus raphe magnus (NRM) and nucleus reticularis gigantocellularis (NGC) was examined 60 min following the intraperitoneal administration of morphine (7.5 mg/kg as base) or saline. The content of 5-HT and 5-HIAA in tissue punches of NRM and NGC was unaltered by the morphine treatment. The content of SP, however, in tissue punches of NRM was significantly elevated 60 min following the administration of morphine.
Decreased sialyltransferase activity in the hearts of cardiomyopathic hamsters

Abstract Sialyltransferase activity was compared in homogenates and microsomal fractions from hearts of cardiomyopathic Syrian hamsters and age-matched normal controls. Decreased enzymatic activity was found in cardiomyopathic hamsters, with most of the decline occurring between the first and second month of life; it was associated with a parallel fall in mcirosomal sialic acid content. Since membrane-bound sialic acid may control Ca2+ exchangeability in cardiac muscle (and, indirectly, tension development), these results provide a biochemical basis for the development of cardiac failure in the Syrian hamster.
The ATP:Co(I)rrinoid Adenosyltransferase (CobA) Enzyme of Salmonella enterica Requires the 2’-OH Group of ATP for Function and Yields Inorganic Triphosphate as Its Reaction Byproduct

The specificity of the ATP:corrinoid adenosyltransferase (CobA) enzyme of Salmonella enterica serovar Typhimurium LT2 for its nucleotide substrate was tested using ATP analogs and alternative nucleotide donors. The enzyme showed broad specificity for the nucleotide base and required the 2'-OH group of the ribosyl moiety of ATP for activity. (31)P NMR spectroscopy was used to identify inorganic triphosphate (PPP(i)) as the byproduct of the reaction catalyzed by the CobA enzyme. Cleavage of triphosphate into pyrophosphate and orthophosphate did not occur, indicating that triphosphate cleavage was not required for release of the adenosylcorrinoid product. Triphosphate was a strong inhibitor of the reaction, with 85% of CobA activity lost when the ATP/PPP(i) ratio present in the reaction mixture was 1:2.5.
Texas A&M University/SPE On-line Electronic Publishing Activities

The Petroleum Engineering Department at Texas A & M University is working with the Society of Petroleum Engineers (SPE) Electronic Publishing Committee (EPC) to develop standards for on-line submission, review, and distribution of technical publications. Generally, electronic publishing is loosely defined as providing information in electronic form. Electronic form can include numerous types of media ranging from floppy disk, CD-ROM and magnetic tape, to delivery across electronic networks. On-line electronic publication refers specifically to delivery of information across local and wide area networks. The INTERNET now interconnects more than 50,000 networks world wide providing an ideal environment for on-line electronic publishing.
Towards balancing learner autonomy and pedagogical process in educational games

We present the preliminary work in the TAEMILE project, which aims to co-regulate the learning process in educational games by automatically balancing learners autonomy and the pedagogical processes intended by educators. We focus on our design rationale and the initial results from our user study.
Role of the adrenal in an experimental myopathy.

Abstract We studied the effect of adrenalectomy on an experimental myopathy which is characterized by subtle morphologic alteration and profound enzyme efflux in rats. Adrenalectomy greatly reduced (by > 85%) the increase in plasma creatine phosphokinase activity and myofibrillar disruption which follow treatment with phencyclidine and restraint. Adrenal demedullation had an identical effect. A single replacement dose of epinephrine in the adrenal-demedullated rat restored the myopathic response. Denervation and β-adrenergic receptor blockade similarly prevented the development of the myopathy. These findings suggest that intense muscle activity, with increased demand for oxygen, can produce extensive architectural changes and elevate plasma creatine phosphokinase activity when adrenal epinephrine is present, perhaps via the calorigenic effect, increasing the rate of oxygen utilization, or via well known effects of epinephrine on neuromuscular transmission or contraction.
Effects of nicotine infusion on the metabolism of the tobacco carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) in rats

The tobacco-specific nitrosamine, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) is a lung carcinogen in the rat and believed to be a causative agent for lung cancer in smokers. To exert its carcinogenic potential NNK is metabolically activated by cytochrome P450-catalyzed alpha-hydroxylation. Nicotine and NNK share metabolic pathways. The purpose of this study was to determine whether nicotine alters the fraction of NNK undergoing activation to carcinogenic metabolites. Rats received acute (36 h) or chronic (2 week) s.c. infusions of nicotine at rates producing serum nicotine concentrations 2-3 times the usual venous nicotine concentrations measured in smokers. A single dose of [5-3H]-NNK was administered i.p. 24 h prior to the end of each infusion. Urine was collected for 24 h thereafter and NNK metabolites quantified by radioflow HPLC. Neither acute nor chronic nicotine infusion had any effect on the extent of NNK metabolism by alpha-hydroxylation. These data suggest that nicotine infusion, at rates simulating the higher doses of nicotine replacement therapy now being studied for smoking cessation, neither induces nor inhibits NNK metabolism appreciably and therefore should not alter the formation of carcinogenic NNK metabolites.
α-Actinin 4 Potentiates Myocyte Enhancer Factor-2 Transcription Activity by Antagonizing Histone Deacetylase 7

Histone deacetylase 7 (HDAC7) is a member of class IIa HDACs that regulate myocyte enhancer factor-2 (MEF2)-mediated transcription and participate in multiple cellular processes such as T cell apoptosis. We have identified α-actinin 1 and 4 as class IIa HDAC-interacting proteins. The interaction domains are mapped to C terminus of α-actinin 4 and amino acids 72-172 of HDAC7. A point mutation in HDAC7 that disrupts its association with MEF2A also disrupts its association with α-actinin 4, indicating that MEF2A and α-actinin 4 binding sites largely overlap. We have also isolated a novel splice variant of α-actinin 4 that is predominantly localized in the nucleus, a pattern distinct from the full-length α-actinin 4, which is primarily distributed in the cytoplasm and plasma membrane. Using small interfering RNA, chromatin immunoprecipitation, and transient transfection assays, we show that α-actinin 4 potentiates expression of TAF55, a putative MEF2 target gene. Loss of MEF2A interaction correlates with loss of the ability of α-actinin 4 to potentiate TAF55 promoter activity. Ectopic expression of α-actinin 4, but not the mutant defective in MEF2A association, leads to disruption of HDAC7·MEF2A association and enhancement of MEF2-mediated transcription. Taken together, we have identified a novel mechanism by which HDAC7 activity is negatively regulated and uncovered a previously unknown function of α-actinin 4.
Mechanism of E. coli RecA protein directed strand exchanges in post-replication repair of DNA.

Escherichia coli mutants carrying recA− are both recombination deficient and unable to perform post-replication repair1,2. The product of the recA gene regulates the inducible DNA repair functions (the SOS response to DNA damage)3,4, and is directly involved in homologous pairing5–8 and strand exchange9–12, two reactions fundamental to recombination and post-replication repair. The filling of post-replication gaps is thought to occur by homologous pairing of the gapped DNA duplex with an intact duplex, followed by cutting of the intact molecule so that sister strand exchanges can take place. Using in vitro systems, we have shown previously that purified RecA protein binds cooperatively to duplex DNA that contains gaps13, and promotes joint molecule formation (synapsis) between gapped and intact duplexes7,8. Moreover, RecA protein promotes a reciprocal exchange of strands between paired DNA molecules10,12,14. Here, we investigate the mechanism of sister strand exchange thought to occur during post-replication repair. We show that RecA protein initiates strand exchange from a nicked duplex, transferring the 3′-OH terminus at the nick into the single-stranded (ss) region of the gapped molecule. In the presence of ATP, two heteroduplex molecules are formed as RecA protein drives the reciprocal exchanges in one direction starting at the site of the original crossover.
A direct GABAergic output from the basal ganglia to frontal cortex

Current models postulate that the basal ganglia nerve cells clustered in the caudate nucleus, putamen and globus pallidus at the base of the forebrain in vertebrates exert their effects on the cerebral cortex indirectly via inhibition of thalamus, and that this circuitry controls movement and reward learning. Bernardo Sabatini and colleagues now describe a previously unrecognized direct anatomical connection from the globus pallidus externus to the frontal cortex, and show that it functionally modulates cortical activity. The activity of this pathway is sensitive to dopamine receptor signalling, suggesting a potentially novel mechanism for the action of dopaminergic drugs used to treat neuropsychiatric disorders.
Characterization and follicle stimulating hormone activation of Sertoli cell cyclic AMP-dependent protein kinases.

The Sertoli cell of the rat testis contains two cytoplasmic forms of adenosine 3′,5′ monophosphate (cyclic AMP)-dependent protein kinase, designated as Peak I and Peak II, which change in relative proportion during Sertoli cell maturation. Peak I and Peak II differ in their subunit interaction. Thus, while the substrates, ATP and histone, affect cyclic AMP binding to Peak I, neither of these compounds affect the binding of cyclic AMP to the Peak II enzyme. The effects on cyclic AMP binding to Peak I appear to be due to the fact that histone and high ionic strength cause dissociation of the Peak I holoenzyme, whereas ATP stabilizes the holoenzyme complex against dissociation. The Peak II holoenzyme is not affected by either salt or histone and is only dissociated by cyclic AMP. Once dissociated, the subunits of Peak II will rapidly reassociate under low salt conditions whereas the subunits of Peak I will not reassociate. By utilizing the distinct properties of Peak I and Peak II, it is possible to demonstr...
Immune response to a murine coronavirus: identification of a homing receptor-negative CD4+ T cell subset that responds to viral glycoproteins.

Abstract The lymphocyte proliferative response to mouse hepatitis virus, strain JHM (MHV-JHM), a well-described cause of chronic and acute neurological infections, has been studied using vaccinia virus recombinants expressing individual MHV proteins. The surface (S) and transmembrane (M) glycoproteins were the most active proteins in causing proliferation of lymphocytes isolated from immunized adult mice, whereas lymphocytes from persistently infected mice proliferated only in response to the S protein. The cells from immunized mice which proliferated most actively in response to MHV were positive for the CD4 antigen and secreted interferon-γ. In addition, the most responsive subset of cells did not express gpg0 MEL-14 , the lymph node-specific homing receptor. The results identify a subpopulation of CD4 + T cells that may be an important component of the cell-mediated immune response to this virus. The data also suggest that response to the M protein is important in preventing disease progression in C57BL/6 mice since cells which recognize this protein are absent from persistently infected mice.
Best Practices for Standards Communities

The technical standards world is in danger of being broken, hijacked, and exploited by partisan legal and political maneuvering. Today we confront a pivotal moment in the world of technology standards, one that also involves the global economy and ecology. The need to rebuild our financial infrastructure and implement ways to preserve and conserve the environment has given many in the technical community a moment of clarity with regard to the role standards must play in these times. There is a growing realization that while the technical standards world has functioned well enough for decades, the system is in danger of being broken, hijacked, and exploited by partisan legal and political maneuvering. Many of us now recognize an opportunity to restore trust and implement consistent and pervasive safeguards in the standards community.
Packaging Effects of Multiple X-Band SiGe LNAs Embedded in an Organic LCP Substrate

Interconnects in radio frequency (RF) packages have a strong tendency to deteriorate RF performance, especially in high-frequency systems. In this paper, comparison is made between the wirebonded and embedded flip-chip packages. X-band silicon-germanium low-noise amplifiers are used to evaluate the performance of these interconnects. Measured results show that the embedded flip-chip packages have better RF performance than the wirebonded packages for X-band applications. At 9.5 GHz, the flip-chip interconnects contribute only 0.4 dB of insertion loss, while the wirebond interconnects contribute 2.2 dB of insertion loss. The flip-chip and wirebond interconnects are modeled and validated against measured results from 8 to 20 GHz. For the first time, multiple dies are put together in a single liquid crystal polymer package to compare the packaging effects, and to demonstrate the feasibility of embedding multiple dies within a single package for highly integrated solutions.
Putting residents in the office: an effective method to teach the systems-based practice competency.

Objectives Systems-based practice (SBP) was 1 of 6 core competencies established by the Accreditation Council for Graduate Medical Education and has proven to be one of the most difficult to effectively implement. This pilot study presents an immersion workshop as an effective tool to teach the SBP competency in a way that could easily be integrated into a residency curriculum. Design In 2006, 16 surgical residents rotated through 3 stations for 30 minutes each: coding and billing, scheduling operations and return appointments, and patient check-in. Participants were administered a pretest and posttest questionnaire evaluating their knowledge of SBP, and were asked to evaluate the workshop. Setting Outpatient clinic at MedStar Georgetown University Hospital, Washington, DC. Participants Residents in the general surgery residency training program at MedStar Georgetown University Hospital. Results Most residents (62.5%) improved their score after the workshop, whereas 31.25% showed no change and 6.25% demonstrated a decrease in score. Overall within their training levels, all groups demonstrated an increase in mean test score. Postgraduate year-2 residents demonstrated the greatest change in mean score (20%), whereas postgraduate year-4 residents demonstrated the smallest change in mean score (3.3%). Conclusions An immersion workshop where general surgery residents gained direct exposure to SBP concepts in situ was an effective and practical method of integrating this core competency into the residency curriculum. Such a workshop could complement more formal didactic teaching and be easily incorporated into the curriculum. For example, this workshop could be integrated into the ambulatory care requirement that each resident must fulfill as part of their clinical training.
In vitro stimulation of apoferritin synthesis by iron.

Abstract The apparent induction of apoferritin synthesis by iron has been examined in cell-free systems from rat and rabbit liver. Both systems allowed the complete synthesis de novo of apoferritin isolated by chromatographic or immunological means. Addition of iron at levels of 0.2–1 mM specifically stimulated incorporation of radioactive amino acids into apoferritin purified after classical heat extraction. The effect was also observed when iron was added at the end of the incubation period in the absence of continuing protein synthesis. Further, iron addition had no effect on the amount of newly synthesised apoferritin subunits as estimated by direct immunological precipitation from the reaction mixture. These results suggest that iron acts at some stage subsequent to translation in stimulating apoferritin biosynthesis.
Ethnography, Evaluation, and Design as Integrated Strategies: A Case Study from WES

The Water in the Earth System (WES) collection is a collection of the Digital Library for Earth SystemEducation. As WES relies on its user community to generate metadataresources; identification of robust user community features, and of potential user community problems, is thereforeimportant. This paper describes (a) how ethnography is being used to studythe WES community; (b) how technological frames theory and technology usemediation theory is being used to analyse this data; and (c) how researchoutcomes are being used to generate recommendations for supporting future WES development.
Autoimmune Pathology of Type 1 Diabetes

A seeming majority of research articles pertaining to Type 1 diabetes (T1D ) begin by noting that the disorder results from an autoimmune destruction of the insulin-secreting pancreatic β cells. This concept finds its basis in decades-old observations that at the symptomatic onset of T1D, a chronic inflammatory infiltrate affecting primarily the insulin-containing islets is present in most subjects. This infiltrate consists predominantly of T-lymphocytes, with lesser numbers of B-lymphocytes and macrophages. Apoptotic β cells, enhanced β cell expression of Fas, T-lymphocyte expression of Fas-L, hyperexpression of class I MHC on all endocrine cells in insulin-containing islets, and interferon α production by β cells are also noteworthy occurrences often seen with this lesion. The subsequent observation of islet cell autoantibodies in the serum of patients with T1D led to its definition as an autoimmune disease (Type 1A diabetes ). In this chapter, we will review the pathology of Type 1A diabetes and discuss its possible pathogenesis on the basis of evidence obtained from pancreatic specimens. Finally, we will briefly discuss nonautoimmune forms of T1D.
Stereotactic Body Radiation Therapy (SBRT) for lung cancer patients previously treated with conventional radiotherapy: a review

Lung cancer continues to be one of the most prevalent malignancies worldwide and is the leading cause of death in both men and women. Presently, local control rates are quite poor. Improvements in imaging and radiation treatment delivery systems however have provided radiation oncologists with new tools to better target these tumors. Stereotactic body radiation therapy (SBRT) is one such technique that has shown efficacy as upfront treatment for lung cancer. In addition, more recent studies have demonstrated some effectiveness in recurrent tumors in prior irradiated fields as well. This review summarizes seven recent studies of re-irradiation with SBRT in patients with thoracic recurrences treated previously with conventionally fractionated radiation therapy. Combined, 140 patients were included. The median initial thoracic radiation doses ranged from 50-87.5 Gy and median re-irradiation dose ranged from 40-80 Gy. Local control rates varied from 65-92%. Re-irradiation was well tolerated with few grade 4 and 5 complications (observed in one study). Currently, based on these published reports, re-irradiation with SBRT appears feasible for in-field thoracic recurrences, though caution must be taken in all cases of retreatment.
Angiogenesis in P- and E-Selectin-Deficient Mice

Objectives:Several observations reported earlier indicated that the selectins, in particular E-selectin, might be involved in angiogenesis; however, mice deficient in the endothelial selectins develop normally. To clarify the role of endothelial selectins in angiogenesis, we have studied experimentally induced angiogenesis in selectin-deficient mice. Methods:Hydron pellets containing either basic fibroblast growth factor or the inflammatory cytokine tumor necrosis factor α were implanted into the corneas of wild-type and P- and/or E-selectin-deficient mice. Results:The lengths and circumferential range of the newly formed blood vessels in the corneas of the endothelial selectin-deficient mice were similar to those of wild-type mice. Conclusion:The endothelial selectins are not essential in experimentally induced angiogenesis in vivo.
Lower limb muscle pre-motor time measures during a choice reaction task associate with knee abduction loads during dynamic single leg landings

Abstract Background Female neuromuscular control during dynamic landings is considered central to their increased ACL injury risk relative to males. There is limited insight, however, into the neuromuscular parameters governing this risk, which may hinder prevention success. This study targeted a new screenable and potentially trainable neuromuscular risk factor. Specifically, we examined whether lower limb muscle pre-motor times, being the time between stimulus presentation and initiation of the muscle EMG burst, elicited during a simple choice reaction task correlated with knee abduction loads during separate single leg landings. Methods Twenty female NCAA athletes had muscle ( n = 8) pre-motor time and knee biomechanics data recorded bilaterally during a choice reaction task. Knee biomechanics were also quantified during anticipated and unanticipated single (dominant and non-dominant) leg landings. Mean peak knee abduction loads during landings were submitted to a two-way ANOVA to test for limb and decision effects. Individual regression coefficients were initially computed between-limb-based muscle pre-motor times and peak abduction moments elicited during both the choice reaction and landing tasks. Limb-based linear stepwise regression coefficients were also computed between muscle PMT's demonstrating significant ( P Findings Peak knee abduction moments were significantly ( P = 0.0001) larger during unanticipated (51.25 (7.41) Nm) compared to anticipated (38.93 (9.32) Nm) landings. Peak abduction moments were significantly ( P r = 0.62 dominant; r = 0.63 non-dominant) and medial hamstring ( r = 0.77 dominant; r = 0.79 non-dominant) pre-motor times elicited within the choice reaction task. Peak abduction moments during anticipated landings were significantly ( P r = 0.60) and non-dominant ( r = 0.59) medial hamstring pre-motor times. For unanticipated landings, non-dominant and dominant peak knee abduction moments were significantly correlated with medial hamstring pre-motor time ( r = 0.78) and combined medial gastroc and medial hamstring pre-motor times ( r = 0.94) respectively. Interpretation Medial muscle pre-motor times during a specific choice reaction task are associated with peak knee abduction loads during separate single leg landings. These muscles appear critical in stabilizing the knee against the extreme dynamic load states associated with such tasks. Targeted screening and training of supraspinal processes governing these muscle pre-motor times may ultimately enable external knee loads associated with landings to be more effectively countered by the overarching neuromuscular strategy.
Negative pressure pulmonary edema.

Negative pressure pulmonary edema (NPPE) is a medical emergency that usually arises from attempted ventilations against an acutely obstructed upper airway, such as occurs during laryngospasm. Often this occurs in the perioperative period when general anesthesia is used. It is most important to the clinician because it must be promptly recognized and appropriately managed. The following is a review of the etiology, pathophysiology, diagnosis, treatment, and dental implications of this process.
A novel algorithm to form stable clusters in vehicular ad hoc networks on highways

Clustering in vehicular ad hoc networks (VANET) is one of the control schemes used to make VANET global topology less dynamic. Many of the VANET clustering algorithms are derived from mobile ad hoc networks (MANET). However, VANET nodes are characterized by their high mobility, and the existence of VANET nodes in the same geographic proximity does not mean that they exhibit the same mobility patterns. Therefore, VANET clustering schemes should take into consideration the degree of the speed difference among neighboring nodes to produce relatively stable clustering structure. In this paper, we introduce a new clustering technique suitable for the VANET environment on highways with the aim of enhancing the stability of the network topology. This technique takes the speed difference as a parameter to create relatively stable cluster structure. We also developed a new multi-metric algorithm for cluster-head elections. A simulation was conducted to evaluate our method and compare it with the most commonly used clustering methods. The simulation results show that our technique provides more stable cluster structure on the locale scale which results in a more stable network structure on the global scale. The proposed technique reduces the average number of clusters changed per vehicle by 34-46%, and increases the average cluster lifetime by 20-48% compared to the existing techniques.
Changing perspective within and across environments

Perspective change within a single environment is a slow and effortful process. However, little research has addressed perspective change across multiple environments. Using a task-set switching paradigm, subjects judged spatial relationships between target locations from differing perspectives. Response times were longer when successive trials probed different perspectives. However, this cost was greater when perspective was changed within a single environment compared to when it was changed across two environments. This result indicates that the processing of perspective change, and perhaps general spatial reasoning, differs in these two cases. Implications for theories of perspective change and environmental knowledge are discussed.
Cardiovascular activity during laboratory tasks in women with high and low worry.

Worry has been related to delayed stress recovery and cardiovascular disease risk. Cardiovascular responses to a range of laboratory tasks were examined in this study of high and low worriers. Undergraduate women were recruited with the Penn State Worry Questionnaire to form low (n = 19) and high (n = 22) worry groups. These individuals engaged in six laboratory tasks (orthostatic stress, supine rest, hand cold pressor, mental arithmetic, and worry and relaxation imagery) while heart rate (HR), HR spectral analysis, impedance cardiography, and blood pressure were acquired. The only significant group difference found was a consistently greater HR across tasks in high worriers (p < .05). No group by condition interactions emerged. High trait worry in healthy young women appears to be marked by elevated HR in the absence of autonomic abnormalities. These findings are discussed relative to the literature on worry, with particular reference to its health implications.