cssi/SciSciGPT-SciSciNet huggingface dataset:
Scattering theory for quantum electrodynamics. II. Reduction and cross-section formulas

The quantum-electrodynamical $S$ matrix is obtained as the set of on-mass-shell values of the renormalized momentum-space Green's functions multiplied by ${C}_{i}{({{m}_{i}}^{2}\ensuremath{-}{{p}_{i}}^{2})}^{1+{\ensuremath{\zeta}}_{i}}$ for each particle $i$, where ${\ensuremath{\zeta}}_{i}$ is proportional to the fine-structure constant and ${C}_{i}$ is a constant. A photon mass is not needed to eliminate virtual infrared divergences. Instead the parameters ${\ensuremath{\delta}}_{i}={{m}_{i}}^{2}\ensuremath{-}{{p}_{i}}^{2}$ regularize Feynman integrals in the infrared region, and the dependence on the ${\ensuremath{\delta}}_{i}$ is canceled against the expansion of ${({{m}_{i}}^{2}\ensuremath{-}{{p}_{i}}^{2})}^{{\ensuremath{\zeta}}_{i}}$ multiplying lower-order Green's functions. Exact cross-section formulas are developed which express transition rates in terms of this $S$ matrix. They account for radiation damping nonperturbatively, whereas the $S$ matrix must be calculated perturbatively as a power series in $\ensuremath{\alpha}$. It is seen that in processes with very small energy loss to unobserved photons individual elements of the quantum-electrodynamical $S$ matrix are directly observable. Rules for practical calculations are summarized.
Is magnetic resonance imaging assessment of the size of articular cartilage defects accurate

The purpose of this study was to systematically review the literature relative to the following question: Is preoperative magnetic resonance imaging (MRI) an accurate instrument for the assessment of the size of knee articular cartilage defects compared with arthroscopy? A systematic search was performed in September 2011 using PubMed MEDLINE (from 1966), CINAHL (from 1982), SPORTDiscus (from 1985), SCOPUS (from 1996), and EMBASE (from 1974) databases. Four studies (one study of Level II and three studies of Level III) were identified that met the predetermined inclusion and exclusion criteria. The ability of MRI to preoperatively assess the size of cartilage lesions was highly variable. As a result of inconsistencies between imaging techniques, the methodological variability and shortcomings of the studies, and the limited amount of data available, a meta-analysis was not performed. There is some evidence that MRI is an accurate tool for preoperatively assessing the dimensions of articular cartilage defects. However, because of the heterogeneity of MRI sequences and the paucity of literature related to preoperative sizing, it is not possible to make definitive conclusions regarding the global clinical utility of MRI for guiding the selection of therapeutic strategies.
ACTIVE ACCUMULATION OF SR2+ BY RAT-LIVER MITOCHONDRIA. II. COMPETITION BETWEEN CA2+ AND SR2+.

Abstract Ca2+ inhibits the respiration-linked accumulation of Sr2+ in a competitive manner. Both ions may be accumulated simultaneously from the medium, the relative amounts of each being determined by the competition. The inhibiting action of Ca2+ is primarily on the rapid phase of Sr2+ uptake. When the ion accumulation is supported by adenosine 5′-triphosphate instead of respiration, the inhibiting effect of Ca2+ on Sr2+ uptake is much less pronounced. The release of both Sr2+ and Ca2+ from “loaded” mitochondria is promoted by 2,4-dinitrophenol.
Returns to Local-Area Healthcare Spending: Evidence from Health Shocks to Patients Far From Home

Healthcare spending varies widely across markets, and previous empirical studies find little evidence that higher spending translates into better health outcomes. The main innovation in this paper exploits this cross-sectional variation in hospital spending in a new way by considering patients who are exposed to healthcare systems not designed for them: patients far from home when a health emergency strikes. Visitors to Florida who become ill in high-spending areas have significantly lower mortality rates compared to visitors in lower-spending areas. The results are robust within groups of similar visitors and within groups of destinations that appear to be close demand substitutes-areas that likely attract similar visitors.
Death Receptor 5, a New Member of the TNFR Family, and DR4 Induce FADD-Dependent Apoptosis and Activate the NF-κB Pathway

Death receptor 4 (DR4) is a recently described receptor for the cytotoxic ligand TRAIL that reportedly uses a FADD-independent pathway to induce apoptosis and does not activate the NF-kappaB pathway. We have isolated a new member of the tumor necrosis factor receptor (TNFR) family, designated DR5, which bears a high degree of sequence homology to DR4. However, contrary to the previous reports, both DR4- and DR5-induced apoptosis can be blocked by dominant-negative FADD, and both receptors can activate NF-kappaB using a TRADD-dependent pathway. Finally, both receptors can interact with FADD, TRADD, and RIP. Thus, both DR5 and DR4 use FADD, TRADD, and RIP in their signal transduction pathways, and FADD is the common mediator of apoptosis by all known death domain-containing receptors.
Can emergency medical services personnel identify pneumothorax on focused ultrasound examinations

Ultrasound is of proven accuracy in the diagnosis of pneumothorax. In certain locations, pre-hospital providers are adopting its use for the management of critically ill patients. To determine the sensitivity and specificity of emergency medical service (EMS) providers in identifying pneumothorax on ultrasound examinations. This was an educational study evaluating 33 EMS providers. Each subject went through a brief didactic session covering the use of ultrasound in diagnosis of pneumothorax. They were then given an examination consisting of 20 individual ultrasound real-time video cases depicting either a pneumothorax or normal lung sliding. Sensitivities and specificities with 95% confidence intervals (95% CIs) were calculated for recognition of pneumothorax. The 33 study participants were able to identify pneumothorax with a sensitivity of 82% (95% CI 77–86%), specificity of 94% (95% CI 90–96%), positive predictive value of 93% (95% CI 89–95%), and negative predictive value of 84% (95% CI 80–87%). Emergency medical service providers were able to identify pneumothorax at a relatively high rate. Real-time scanning by the study subjects might lead to even better results.
Ecological Correlates of Effective Foster Care.

ABSTRACT Providing effective foster care is a major undertaking that continues to plague this country. The ultimate goal of substitute care is to provide child victims of maltreatment with a safe and nurturing home environment. The goal of this theory driven research project was to identify ecological factors correlated with effective non-kin family foster care. Various levels of analysis were considered including individual, family and community. The findings of this study identified three factors as significant predictors of effective foster care. Included are implications for social work in the areas of practice, policy, and research.
How frequently does head CT affect decision making in the emergency setting

Objective: To determine the overall frequency with which head computed tomography (HCT) affects decision-making in emergency department (ED) patients overall and on the basis of specific clinical findings and indications. Methods: Staff requesting HCT scans from the ED prospectively completed a form detailing patient complaints, selected history and physical findings, and likely disposition based upon clinical findings. After completion of the HCT, the clinician reported whether the HCT scan affected therapy and in what way. Results: Of a total 567 patient-visits from June 9, 1999 through September 7, 2000, HCT altered therapy 22 % of the time. The most frequent alterations in care as a result of the CT were: medications withheld or given, indwelling shunt adjustment, and alteration in stroke protocol. A significant number of patients in all risk categories had their care altered. There was a correlation between physicians' pre-HCT assessment of the likelihood that HCT would affect emergency care and the frequency that HCT did alter care. Conclusions: A high rate of unexpected therapy and disposition changes occurred on the basis of HCT in all risk categories of ED patients. History and physical data were good predictors of the utility of this study.
Misguided multiplication: creating false memories with numbers rather than words.

We built Deese (1959)/Roediger and McDermott (1995) (DRM) false memory lists composed of multiplication problems rather than words. Half these lists contained table-related, near neighbors (e.g., 3 × 7 = ??, 3 × 9 = ??) of a missing multiplication answer lure (e.g., 24). The other half contained problems unrelated to the lure (e.g., 5 × 5 = ??, 11 × 3 = ??). Participants solved each problem in a single list and then took immediate recognition (Experiment 1) or recall and then recognition tests (Experiment 2) for the answers. Many people misremembered that the lure was an answer to a study-phase problem, but only when solving the study list that contained the lure’s neighbors. False memory was also greater for some list-lure combinations than others, as seen previously with words. We have thus demonstrated that numbers can also produce false memory, and we use the mental math and DRM task literatures to explain these results.
Reference scenarios for deforestation and forest degradation in support of REDD: a review of data and methods

Global climate policy initiatives are now being proposed to compensate tropical forest nations for reducing carbon emissions from deforestation and forest degradation (REDD). These proposals have the potential to include developing countries more actively in international greenhouse gas mitigation and to address a substantial share of the world's emissions which come from tropical deforestation. For such a policy to be viable it must have a credible benchmark against which emissions reduction can be calculated. This benchmark, sometimes termed a baseline or reference emissions scenario, can be based directly on historical emissions or can use historical emissions as input for business as usual projections. Here, we review existing data and methods that could be used to measure historical deforestation and forest degradation reference scenarios including FAO (Food and Agricultural Organization of the United Nations) national statistics and various remote sensing sources. The freely available and corrected global Landsat imagery for 1990, 2000 and soon to come for 2005 may be the best primary data source for most developing countries with other coarser resolution high frequency or radar data as a valuable complement for addressing problems with cloud cover and for distinguishing larger scale degradation. While sampling of imagery has been effectively useful for pan-tropical and continental estimates of deforestation, wall-to-wall (or full coverage) allows more detailed assessments for measuring national-level reference emissions. It is possible to measure historical deforestation with sufficient certainty for determining reference emissions, but there must be continued calls at the international level for making high-resolution imagery available, and for financial and technical assistance to help countries determine credible reference scenarios. The data available for past years may not be sufficient for assessing all forms of forest degradation, but new data sources will have greater potential in 2007 and after. This paper focuses only on the methods for measuring changes in forest area, but this information must be coupled with estimates of change in forest carbon stocks in order to quantify emissions from deforestation and forest degradation.
Incorporating writing techniques in the accounting classroom: Experience in financial, managerial and cost courses

Abstract The importance of incorporating writing within the classroom is increasingly asserted by practitioners and professional organizations. This paper reports on the use of specific types of writing techniques (viz., freewrites, course logs, and letters) which were employed by the authors (at two different institutions) in three different undergraduate courses: financial, managerial and cost accounting. The techniques were informal in nature and were designed to introduce writing requirements to the student within an accounting setting in a nonthreatening fashion. Experience with these techniques indicates that they were useful in developing communications channels between students and instructor and among students (peer review). Furthermore, a common characteristic of the three courses was a student perception of an enhanced learning environment in the classroom.
Stabilization of PCBM domains in bulk heterojunctions using polystyrene-tethered fullerene

Abstract The domain size of [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) in the bulk heterojunction (BHJ) of organic photovoltaic (OPV) devices is of great importance to the performance and lifetime of a device. This study focuses on the use of polystyrene-tethered fullerenes (PTFs) as an additive to reduce the initial domain size of PCBM as well as to mitigate the growth of these domains over time that typically results in decreased device efficiency. Films were prepared from a 1:1 mixture of P3HT:PCBM on silicon wafers to approximate a BHJ system. PTFs were added in concentrations ranging from 0 to 20%. The samples were then annealed at 150 °C for varying times ranging from 5 to 60 min and examined by SEM to determine the average PCBM domain sizes for each sample. As expected, the control sample containing no additive showed significant growth in the PCBM domains as the sample was annealed with a final average domain size of 290 μm 2 . However, addition of as little as 5% PTFs produced average PCBM domain sizes after 60 min of annealing of 28 μm 2 . Addition of 20% PTF resulted in an average PCBM domain size of 2 μm 2 . Photoluminescence spectroscopy (PL) studies were performed on the films to study their electrical properties and based on these encouraging results; devices containing these architectures were prepared. OPVs with PTFs showed an increased lifetime, and in some cases, an increase in efficiency over devices containing no PTF.
Interpretation of measured variations of the eddy conductivity

Abstract An interpretation is given of the observed variation of eddy conductivities, e h , in a heated channel. A homogeneous model which assumes constant turbulence properties and a plug flow explains the gross features of the eddy conductivity profile. The large variation of e k close to the wall is explained as mainly due to the time dependency of the turbulent diffusion process. In order to get closer agreement with measurements, the homogeneous model has to be modified to account for the variation of average velocity and turbulence intensity. This is done and values of the von Karman constant for heat transfer are calculated which are in good agreement with experiment.
Should I follow my feelings? How individual differences in following feelings influence affective well-being, experience, and responsiveness

Abstract Individuals high in the propensity to follow their feelings notice their feelings and use the information provided by their feelings. We investigate the hypothesis that following feelings is a multidimensional, rather than a unidimensional, construct. We reasoned that people follow their positive feelings because these feelings signal the presence of rewards that should be approached and follow their negative feelings because these feelings signal the presence of threats that should be avoided. Because approach and avoidance stem from independent motivational systems, we hypothesized and found that following positive feelings and following negative feelings are separable dimensions. In part 1, we developed a measure, called the Following Affective States Test (FAST), to assess these dimensions and provided psychometric data supporting its adequacy. In part 2, we continued to validate the scale and found that this new conceptualization clarifies the debate concerning whether following feelings is psychologically beneficial. In part 3, we tested the utility of the FAST by demonstrating that it predicts the degree to which individuals notice, react to, and use positive and negative affective information.
Mechanisms of toxic action and structure-activity relationships for organochlorine and synthetic pyrethroid insecticides.

The mechanisms and sites of action of organochlorine (DDT-types and chlorinated alicyclics) and synthetic pyrethroid insecticides are presented with discussion of symptoms, physiological effects, a...
Integration of nanostructured materials with MEMS microhotplate platforms to enhance chemical sensor performance

The development of miniaturized chemical sensors is an increasingly active area of research. Such devices, particularly when they feature low mass and low power budgets, can impact a broad range of applications including industrial process monitoring, building security and extraterrestrial exploration. Nanostructured materials, because of their high surface area, can provide critical enhancements in the performance of chemical microsensors. We have worked to integrate nanomaterial films with MEMS (microelectromechanical systems) microhotplate platforms developed at the National Institute of Standards and Technology in order to gain the benefits of both the materials and the platforms in high-performance chemical sensor arrays. Here, we describe our success in overcoming the challenges of integration and the benefits that we have achieved with regard to the critical sensor performance characteristics of sensor response, speed, stability and selectivity. Nanostructured metal oxide sensing films were locally deposited onto microhotplates via chemical vapor deposition and microcapillary pipetting, and conductive polymer nanoparticle films were deposited via electrophoretic patterning. All films were characterized by scanning electron microscopy and evaluated as conductometric gas sensors.
47. Differing trafficking and TNF-alpha production by monocyte subsets under adrenergic activation: Blunted mobilization of “pro-inflammatory” monocytes in individuals with elevated blood pressure

Elevated blood pressure (BP) and infiltration of the vasculature by monocytes contribute to vascular pathology; but, monocyte migratory characteristics based on differing inflammatory potential under adrenergic activation remains unclear. We compared “non-classical” (CD16++CD14+), “intermediate” (CD16+CD14++), and “classical” (CD16-CD14++) monocyte trafficking and their LPS-stimulated TNF-alpha production in response to a physical stressor (20-min treadmill exercise at 65–70% VO2peak) in participants (n = 77) with high pre-hypertension (PHT), mild PHT or normal BP (NBP). To determine adrenergic receptor sensitivity, pre-exercise cells were also treated with isoproterenol (Iso) before LPS stimulation. Monocyte subpopulations and intracellular TNF-alpha production were evaluated by flow cytometry. Epinephrine and norepinephrine levels were significantly elevated during exercise. Overall, % non-classical monocytes increased, % intermediate did not change, whereas % classical decreased post-exercise (p < .001). However, the % increase in non-classical monocytes under adrenergic activation was blunted in PHT individuals (p < .05). TNF-alpha production in all subsets decreased post-exercise and with in-vitro Iso treatment, irrespective of BP (p < .001), with nonclassical and intermediate monocytes being a major source of TNF-alpha production. These findings extend our previous reports by showing that the mobilization of “pro-inflammatory” monocytes under sympathoadrenal activation is attenuated with even mild BP elevation. This may be indicative of monocytic adrenergic receptor desensitization and/or greater adhesion of “pro-inflammatory” monocytes to the vascular endothelium in hypertension with clinical implications of vascular pathology.
Self-Assembly of Supramolecular Light-Harvesting Arrays from Covalent Multi-Chromophore Perylene-3,4:9,10-bis(dicarboximide) Building Blocks

We report on two multi-chromophore building blocks that self-assemble in solution and on surfaces into supramolecular light-harvesting arrays. Each building block is based on perylene-3,4:9,10-bis(dicarboximide) (PDI) chromophores. In one building block, N-phenyl PDI chromophores are attached at their para positions to both nitrogens and the 3 and 6 carbons of pyromellitimide to form a cross-shaped molecule (PI-PDI4). In the second building block, N-phenyl PDI chromophores are attached at their para positions to both nitrogens and the 1 and 7 carbons of a fifth PDI to produce a saddle-shaped molecule (PDI5). These molecules self-assemble into partially ordered dimeric structures (PI-PDI4)2 and (PDI5)2 in toluene and 2-methyltetrahydrofuran solutions with the PDI molecules approximately parallel to one another primarily due to π−π interactions between adjacent PDI chromophores. On hydrophobic surfaces, PDI5 grows into rod-shaped nanostructures of average length 130 nm as revealed by atomic force microscopy...
High Rate Response and Dynamic Failure of Structural Ceramics

The process of dynamic failure of four structural ceramics subjected to unconfined uniaxial dynamic compression is investigated. The four materials examined are α-SiC, AD995 Al2O3, β-Si3N4, and SiAlON. In each case, the dynamic failure process is studied through dynamic loading of cylindrical specimens within a compression Kolsky bar combined with high-speed photography. Strain rates in the range of 103 s−1 are achieved (the corresponding loading rates are on the order of 200 MPa/us). The dynamic failure process for all four ceramics consists of the development and propagation of axial splitting cracks followed by columnar fragmentation. Macroscopic cracks (propagating with crack velocities of several hundred meters per second) and substantial volumetric strains are observed well before the peak strength is attained.
Properties of voltage-gated ion channels formed by syringomycin E in planar lipid bilayers.

Using the planar lipid bilayer technique we demonstrate that the lipodepsipeptide antibiotic, syringomycin E, forms voltage-sensitive ion channels of weak anion selectivity. The formation of channels in bilayers made from dioleoylglycerophosphatidylserine doped with syringomycin E at one side (1–40 μg/ml) was greatly affected by cis-positive voltage. A change of voltage from a positive to a negative value resulted in (i) an abrupt increase in the single channel conductance (the rate of increase was voltage dependent) simultaneous with (ii) a closing of these channels and an exponential decrease in macroscopic conductance over time. The strong voltage dependence of multichannel steady state conductance, the single channel conductance, the rate of opening of channels at positive voltages and closing them at negative voltages, as well as the observed abrupt increase of single channel conductance after voltage sign reversal suggest that the change of the transmembrane field induces a significant rearrangement of syringomycin E channels, including a change in the spacing of charged groups that function as voltage sensors. The conductance induced by syringomycin E increased with the sixth power of syringomycin E concentration suggesting that at least six monomers are required for channel formation.
Computing models of CDF and DØ in Run II

The next collider run of the Fermilab Tevatron, Run II, is scheduled for autumn of 1999. Both experiments, the Collider Detector at Fermilab (CDF) and the DO experiment are being modified to cope with the higher luminosity and shorter bunchspacing of the Tevatron. New detector components, higher event complexity, and an increased data volume require changes from the data acquisition systems up to the analysis systems. In this paper we present a summary of the computing models of the two experiments for Run II.
Alexithymia and Pathological Gambling

Alexithymia is increased in addictive disorders such as alcoholism, cocaine abuse, and binge eating. Pathological gambling is a form of addictive disorder and may be influenced by alexithymia. We examined the association of alexithymia (Toronto Alexithymia Scale) and pathological gambling (South Oaks Gambling Screen) in 1,147 young adults; 3.1% were classified as pathological gamblers. Alexithymia was found in 31.4% of pathological gamblers, compared to 11.1% of controls; both affective and cognitive aspects of alexithymia were associated with gambling problems. The relationship was independent of depression and physical illness, and was found for both sexes, but only for Caucasians. Alexithymia may be a risk factor for pathological gambling in some populations.
Serial analysis of gene expression during elongation of the peri-implantation porcine trophectoderm (conceptus)

Conceptus loss during the preimplantation and early postimplantation period hinders the efficiency of swine reproduction. Significant conceptus loss occurs during trophectoderm elongation between g...
Relative Inhalation Toxicity in Rats of Pyrolysis Products from Polymeric Materials

Twenty-eight polymeric materials used in the manufacture of transit equipment were evaluated for relative inhalation toxicity. 10 g of each were pyrolysed at 450, 550, 650, 750, and 850°C and the pyrolysis products were allowed to enter a 225 L cylindrical plexiglass chamber containing a cir cular, chambered unit rotating at 3 rpm. The system was semi-closed with con stant fresh air intake and recirculation of pyrolysis products. From initial py rolysis experiments without rats, using gas chromatographic analysis at 2, 4, 6, 8, 12, 16, 20, and 30 minutes, toxicity experiments were carried out at three temperatures for all the polymeric materials. For each toxicity study, four S/D rats, two males and two females, weighing 150 ± 15 g were used. 10 g of test material were used and chamber air analysed for toxic gases at 2, 4, 6, 8, 12, 16, 20, and 30 minutes of the exposure period. Amber fog lights enabled obser vation of time to incapacitation (Ti). The number of animals dying in the cham ber, or within the...
Potential North American Vectors of West Nile Virus

The outbreak of disease in the New York area in 1999 due to West Nile (WN) virus was the first evidence of the occurrence of this virus in the Americas. To determine potential vectors, more than 15 mosquito species (including Culex pipiens, Cx. nigripalpus, Cx. quinquefasciatus, Cx. salinarius, Aedes albopictus, Ae. vexans, Ochlerotatus japonicus, Oc. sollicitans, Oc. taeniorhynchus, and Oc. triseriatus) from the eastern United States were evaluated for their ability to serve as vectors for the virus isolated from birds collected during the 1999 outbreak in New York. Mosquitoes were allowed to feed on one- to four-day old chickens that had been inoculated with WN virus 1-3 days previously. The mosquitoes were incubated for 12-15 days at 26 degrees C and then allowed to refeed on susceptible chickens and assayed to determine transmission and infection rates. Several container-breeding species (e.g., Ae. albopictus, Oc. atropalpus, and Oc. japonicus) were highly efficient laboratory vectors of WN virus. The Culex species were intermediate in their susceptibility. However, if a disseminated infection developed, all species were able to transmit WN virus by bite. Factors such as population density, feeding preference, longevity, and season of activity also need to be considered in determining the role these species could play in the transmission of WN virus.
A história da publicação do mapa da América do Norte de John Mitchell de 1755

This article analyses the John Mitchell's eight-sheet, Map of the British and French Dominions in North America, first published in 1755. This map poses a significant challenge to the traditional approaches to the History of Cartography in which maps are studied according to the regions they depict rather than the contexts within which they were made and used. In particular, we must organize our historical narratives and cartobibliographies around not the regions and places mapped, but rather the contexts within which maps were made and used.
Identification and characterization of a macrophage-tropic SIV envelope glycoprotein variant in blood from early infection in SIVmac251-infected macaques

Macrophages play an important role in HIV/SIV pathogenesis by serving as a reservoir for viral persistence in brain and other tissues. Infected macrophages have been detected in brain early after infection, but macrophage-tropic viruses are rarely isolated until late-stage infection. Little is known about early variants that establish persistent infection in brain. Here, we characterize a unique macrophage-tropic SIV envelope glycoprotein (Env) variant from two weeks post-infection in blood of an SIVmac251-infected macaque that is closely related to sequences in brain from animals with neurological disease. SIVmac251 clones expressing this Env are highly fusogenic, and replicate efficiently in T cells and macrophages. N173 and N481 were identified as novel determinants of macrophage tropism and neutralization sensitivity. These results imply that macrophage-tropic SIV capable of establishing viral reservoirs in brain can be present in blood during early infection. Furthermore, these SIVmac251 clones will be useful for studies on pathogenesis, eradication, and vaccines.
Energy transfer from cyclohexane to benzene in their irradiated mixtures

Abstract The fluorescence of both cyclohexane and benzene in their irradiated mixtures has been studied as a function of benzene concentration from ∼ 0.005 to 0.1 M. The quenchi by benzene is found to be significantly greater than obtained under optical excitation conditions suggesting an important role for benzene as a scavenger of the geminate ion-pair precursor of the fluorescing state of cyclohexane. From diffusion models, a lower bound is established for the scavenging rate constant. An examination of the fluorescence from benzene leads to the conclusion that although the majority of benzene fluorescence drives from electronic energy transfer from excited cyclohexane, a large fraction (from 20 to 50% over the concentration range studied) is generated by recombining molecular ions. The intrinsic efficiency with which the recombining ions generate fluorescent states of benzene, however, appears to be peculiarly low.
The siderophore yersiniabactin binds copper to protect pathogens during infection

Bacterial pathogens secrete chemically diverse iron chelators called siderophores, which may exert additional distinctive functions in vivo. Among these, uropathogenic Escherichia coli often coexpress the virulence-associated siderophore yersiniabactin (Ybt) with catecholate siderophores. Here we used a new MS screening approach to reveal that Ybt is also a physiologically favorable Cu(II) ligand. Direct MS detection of the resulting Cu(II)-Ybt complex in mice and humans with E. coli urinary tract infections demonstrates copper binding to be a physiologically relevant in vivo interaction during infection. Ybt expression corresponded to higher copper resistance among human urinary tract isolates, suggesting a protective role for this interaction. Chemical and genetic characterization showed that Ybt helps bacteria resist copper toxicity by sequestering host-derived Cu(II) and preventing its catechol-mediated reduction to Cu(I). Together, these studies reveal a new virulence-associated function for Ybt that is distinct from iron binding.
The connections of the medial preoptic region and maternal behavior in the rat

Abstract Female rats which are hysterectomized and ovariectomized on Day 16 of pregnancy and injected with estrogen show a short latency to onset of maternal behavior when presented with test pups 48 hrs later. In the present experiment, female rats were treated similarly except that on Day 16 of pregnancy they received knife cuts which severed either the lateral, anterior, dorsal, or posterior connections of the medial preoptic area (MPOA), or sham knife cuts. Severing the lateral connections of the MPOA severely disrupted materal behavior, while severing the dorsal or posterior connections of the MPOA produced either minor deficits or no deficits. Severing the anterior connections of the MPOA did produce large deficits in maternal behavior, but this was associated with hypoactivity and loss of body weight. Therefore, the maternal behavior deficits observed in the anterior cut group may have been a secondary effect of the knife cut. The results emphasize the importance of the lateral connections of the MPOA for maternal behavior.
Etching of high-reflecting thin-film assemblies using ion-beam-figuring techniques

Ion-beam-figuring techniques have been applied to fabricate high-power transmission gratings for use in photo-acoustic spectroscopy. A thin-film assembly of SiO2 and TiO2 layers on an SiO2 substrate provides a high-reflecting characteristic at a desired wavelength. With standard photolithographic techniques a grating pattern is developed on the surface of the assembly then ion etched with ion-beam-figuring techniques. These gratings exhibit an increased factor of 25 in acoustic signal levels when compared with previously used chemical-etched silicon gratings. This increase was obtained owing to higher transmission, less thermal distortion, and the ability to withstand higher incident power levels.
Response to Letter by Bath et al

Response: We read with interest the comments of Dr Bath and his associates related to our article. The focus of our report was the persistence of the effect of chlorthalidone-based therapy in significantly decreasing cardiovascular mortality up to 14.3 years after randomization in spite of the advice to all SHEP participants to receive …
Notch to remember

Some of the signaling molecules required for formation of long-term memories are involved primarily in adult brain function, but others participate in a variety of other biological processes. The Notch signaling pathway, which is important for cell fate specification and differentiation in various systems, is also active in the mature brain. Here, we review evidence from recent studies indicating that Notch signaling is required for formation of long-term memories, and discuss possible memory processes modulated by this pathway. We also consider the possible involvement of Notch signaling in cognitive disorders.
Association and Distribution of Meiotic Chromosomes in a Haploid of Ricinus communis L

In a haploid of Ricinus communis L., the ten chromosomes are unpaired at pachytene but they frequently display end-to-end association. This kind of association is also common in diplotene.At diakinesis, there is considerable variation among PMC's in number of chromosomes involved and in frequency of different associations in each association. Associations involving only two chromosomes do not appear as genuine bivalents and associations of more than two chromosomes often resemble chains.Chromosome distribution at metaphase I is as follows: in 78.2% of the PMC's (N=238), all ten univalents are scattered haphazardly; in 16% of the PMC's, some or all of the univalents are oriented at the equatorial plate; and in 5.8% of the PMC's, the univalents are found in 2 polar groupings.This study does not support the hypothesis of polyploid origin of Ricinus as proposed by Narain and Singh (1968).
Petrochemistry of the Fish Cove rhyolite, Keweenaw peninsula, Michigan, U.S.A.

Abstract A small (360 × 180 m) rhyolitic intrusive body in the lower portion of the Portage Lake Lava Series of Michigan's Keweenaw peninsula was mapped and sampled in detail. The rhyolite is one of a number of similar bodies which make up less than 1% of the total volume of this thick Late-Precambrian plateau basalt pile. The rock is a low-calcium rhyolite with fine-grained homogeneous texture and sparse phenocrysts of plagioclase and quartz. Analyses of selected trace and major elements for 21 samples taken from the body reveal a chemical zonation consisting of a core zone enriched in K, Rb and Ba, and a border zone relatively poor in these elements. Little areal difference is found with respect to other elements tested (Mn, Sr, Zr, Ca, Ti, and Fe). This apparently primary zonation seems to result from the migration of K, Rb and Ba during crystallization of the shallow intrusive. Though zoned, the trace-element chemistry of the Fish Cove body is distinct from that of eight other rhyolites in the Portage Lake Lava Series, and suggests that fingerprinting by trace elements might be a fruitful method for identifying and correlating the sources of numerous rhyolitic pebbles in conglomerates interbedded with the basaltlava flows of the Portage Lake Series.
Composition of the atmosphere at the surface of Mars: detection of argon-36 and preliminary analysis.

The composition of the Martian atmosphere was determined by the mass spectrometer in the molecular analysis experiment. The presence of argon and nitrogen was confirmed and a value of 1 to 2750 plus or minus 500 for the ratio of argon-36 to argon-40 was established. A preliminary interpretation of these results suggests that Mars had a slightly more massive atmosphere in the past, but that much less total outgassing has occurred on Mars than on earth.
Tuning the erosion rate of artificial protein hydrogels through control of network topology

Erosion behaviour governs the use of physical hydrogels in biomedical applications ranging from controlled release to cell encapsulation. Genetically engineered protein hydrogels offer unique means of controlling the erosion rate by engineering their amino acid sequences and network topology. Here, we show that the erosion rate of such materials can be tuned by harnessing selective molecular recognition, discrete aggregation number and orientational discrimination of coiled-coil protein domains. Hydrogels formed from a triblock artificial protein bearing dissimilar helical coiled-coil end domains (P and A) erode more than one hundredfold slower than hydrogels formed from those bearing the same end domains (either P or A). The reduced erosion rate is a consequence of the fact that looped chains are suppressed because P and A tend not to associate with each other. Thus, the erosion rate can be tuned over several orders of magnitude in artificial protein hydrogels, opening the door to diverse biomedical applications.
Digestive gland and integument lesions associated with malnutrition in a ghost shrimp, Callianassa affinis☆

Abstract A ghost shrimp, Callianassa affinis , maintained alone in an aerated seawater aquarium, refused food for 2 months. During this time it developed grossly visible lesions in the integument, became progressively more listless, and finally died. Histologic study of selected tissues revealed an abnormal accumulation of fat and a marked blood-cell response in the digestive gland (“liver”). The integument lesions consisted primarily of fragmented cuticle underlain by blood cells in various stages of necrosis. Blood cells further from the surface were healthier and were frequently seen in whorls of one or more cell layers around pigmented material. A likely cause of death was digestive gland failure due to a lack of dietary lipotropic factors that, in mammals at least, normally prevent excessive fat accumulation in the liver. The integument lesions may represent pathological changes that are part of a syndrome of malnutrition.
A high-stiffness axial resonant probe for atomic force microscopy

A high-stiffness, (>500 N/m) resonant atomic force microscope probe was constructed to allow force measurements in the presence of large force gradients. The probe employs a piezoresistively detected, electrostatically driven resonant beam sensor oriented perpendicularly to the sample surface. This probe is distinguished from shear force microscopy and noncontact atomic force microscopy in that the design allows for a stationary probe tip for improved spatial resolution and measures forces rather than force gradients. Measured results show a force resolution of 9 nN in a 1-kHz bandwidth in air with an oscillation amplitude of 36 nm and a resonance quality of 20. In a 1-mtorr vacuum the force resolution in the same bandwidth improves to 200 pN with a resonance quality of 450 and oscillation amplitude of 53 nm. This resolution is limited by white noise of the piezoresistor, and scales as expected with amplitude and resonance quality.
Shallow subsurface structure of the Wasatch fault, Provo segment, Utah, from integrated compressional and shear-wave seismic reflection profiles with implications for fault structure and development

Integrated vibroseis compressional and experimental hammer-source, shear-wave, seismic reflection profiles across the Provo segment of the Wasatch fault zone in Utah reveal near-surface and shallow bedrock structures caused by geologically recent deformation. Combining information from the seismic surveys, geologic mapping, terrain analysis, and previous seismic first-arrival modeling provides a well-constrained cross section of the upper ∼500 m of the subsurface. Faults are mapped from the surface, through shallow, poorly consolidated deltaic sediments, and cutting through a rigid bedrock surface. The new seismic data are used to test hypotheses on changing fault orientation with depth, the number of subsidiary faults within the fault zone and the width of the fault zone, and the utility of integrating separate elastic methods to provide information on a complex structural zone. Although previous surface mapping has indicated only a few faults, the seismic section shows a wider and more complex deformation zone with both synthetic and antithetic normal faults. Our study demonstrates the usefulness of a combined shallow and deeper penetrating geophysical survey, integrated with detailed geologic mapping to constrain subsurface fault structure. Due to the complexity of the fault zone, accurate seismic velocity information is essential and was obtained from a first-break tomography model. The new constraints on fault geometry can be used to refine estimates of vertical versus lateral tectonic movements and to improve seismic hazard assessment along the Wasatch fault through an urban area. We suggest that earthquake-hazard assessments made without seismic reflection imaging may be biased by the previous mapping of too few faults.
System test of dynamic gain equalizer in long haul transmission

We tested a dynamic gain equalizer (DGE) in a 6 /spl times/ 100 km transmission system setting with 7 amplifiers, and we evaluated the performance of the transmission link with the DGE at different locations.
Inherited Bone Marrow Failure Syndromes: Molecular Features

Recent advances resulting from the identification of the genes responsible for four inherited marrow failure syndromes, Fanconi anemia, dyskeratosis congenita, Diamond-Blackfan anemia, and Shwachman-Diamond syndrome, are reviewed. The interpretation of genetic testing should be guided by an understanding of the limitations of such testing for each disorder. The possibility of an inherited basis for marrow failure must be considered for adults as well as children with aplastic anemia. Shared molecular themes are emerging from functional studies of the genes underlying the different inherited disorders. Genomic instability may result from impaired DNA repair in Fanconi anemia or telomere dysregulation in dyskeratosis congenita. Mutations affecting ribosome assembly or function are associated with Diamond-Blackfan anemia, dyskeratosis congenita, and Shwachman-Diamond syndrome. These findings raise new questions about the molecular mechanisms regulating hematopoiesis and leukemogenesis. Clinical implications arising from these molecular studies are explored.
FK506 vs. cyclosporin

Abstract Introduction: Whether FK506 or cyclosporin is better for chronic immunosuppression in heart transplant patients has been debated. We examined endomyocardial biopsies from patients treated with these two drugs to determine if there was a difference in frequency of histologic cellular rejection episodes and Quilty lesions. The Quilty lesion (AKA cyclosporin effect) may be an atypical form of rejection, and is thought to be related to the use of cyclosporin immunosuppression. Methods: We reviewed 1067 endomyocardial biopsies from 65 patients who were assigned FK506 or cyclosporin after heart transplantation. Results: The number of episodes of rejection (162 FK506 vs. 145 cyclosporin) was the same. However, when compared to cyclosporin treatment, FK506 was associated with significantly more Quilty A lesions and fewer Quilty B lesions. Conclusion: FK506 appears to prevent some Quilty A lesions from progressing to Quilty B lesions. Since Quilty B lesion is associated with myocyte injury and Quilty A is not, this effect of FK506 could be associated with improved long-term graft function.
The treatment of epilepsy by cortical excision.

Summary 1. Surgical treatment for focal epilepsy should be considered when medical management has failed. 2. The focal nature of an epilepsy may be suggested by the clinical history, the electroencephalogram, pneumoencephalogram, and angiogram, but only established by the critical examination of the entire clinical picture colored by the results of the various diagnostic tests. 3. Three cases are presented illustratingthe various types of cortical resections for focal epilepsy. 4. Depending upon the extent of thefocus, subpial resection, partial lobectomy, or hemispherectomy may be necessary to eliminate the abnormal activity. 5. The results offer promise to agroup of focal epilepsies otherwise considered incurable.
Endothelial Cells Derived From Nuclear Reprogramming

The endothelium plays a pivotal role in vascular homeostasis, regulating the tone of the vascular wall, and its interaction with circulating blood elements. Alterations in endothelial functions facilitate the infiltration of inflammatory cells and permit vascular smooth muscle proliferation and platelet aggregation. Therefore, endothelial dysfunction is an early event in disease processes including atherosclerosis, and because of its critical role in vascular health, the endothelium is worthy of the intense focus it has received. However, there are limitations to studying human endothelial function in vivo, or human vascular segments ex vivo. Thus, methods for endothelial cell (EC) culture have been developed and refined. Recently, methods to derive ECs from pluripotent cells have extended the scientific range of human EC studies. Pluripotent stem cells may be generated, expanded, and then differentiated into ECs for in vitro studies. Constructs for molecular imaging can also be employed to facilitate tracking these cells in vivo. Furthermore, one can generate patient-specific ECs to study the effects of genetic or epigenetic alterations on endothelial behavior. Finally, there is the opportunity to apply these cells for vascular therapy. This review focuses on the generation of ECs from stem cells; their characterization by genetic, histological, and functional studies; and their translational applications.