cssi/SciSciGPT-SciSciNet huggingface dataset:
Application of trained Deep BCD-Net to iterative low-count PET image reconstruction

Image reconstruction in low-count PET is challenging because gammas from natural radioactivity in Lu-based crystals cause high random fractions that lower the measurement signal-to-noise-ratio (SNR). In model-based image reconstruction, using more iterations of an unregularized method may increase the noise, so incorporating regularization into the image reconstruction is desirable to control the noise. New regularization methods based on learned convolutional operators are emerging in iterative reconstruction. We apply the newly developed block coordinate descent network (BCD-Net) to PET reconstruction by modifying the image reconstruction module to incorporate PET physics. Using the XCAT phantom we simulated the low true coincidence count-rates with high random fractions typical for Y-90 PET patient imaging after Y-90 microsphere radioembolization. We trained a 10 layer BCD-Net where each layer has 200 convolutional filters that encode/decode an input image. Numerical results show that deep BCD-Net significantly improves PET reconstruction performance compared to iterative image reconstruction using non-trained regularizers (total variation (TV) and non-local means (NLM)). We selected the regularization parameter for each method to obtain the highest contrast to noise ratio (CNR). BCD-Net improved activity recovery for a hot sphere significantly and reduced noise, whereas non-trained regularizers had a tradeoff between noise and quantification. BCD-Net improved CNR and activity recovery by 96.6% (150.0%) and 41.5% (35.9%) compared to TV (NLM) regularized reconstruction.
ACM SIGGRAPH 2006 Special sessions

Intermixtures of advanced design, engineering breakthroughs, and deep interactivity. In Special Sessions, leading explorers demonstrate recent achievements in ocean exploration, vehicle performance and marketing, interactive performance, and character animation.
Geovisual Analytics and Interactive Machine Learning for Situational Awareness.

The first responder community has traditionally relied on calls from the public, officially-provided geographic information and maps for coordinating actions on the ground. The ubiquity of social media platforms created an opportunity for near real-time sensing of the situation (e.g. unfolding weather events or crises) through volunteered geographic information. In this article, we provide an overview of the design process and features of the Social Media Analytics Reporting Toolkit (SMART), a visual analytics platform developed at Purdue University for providing first responders with real-time situational awareness. We attribute its successful adoption by many first responders to its user-centered design, interactive (geo)visualizations and interactive machine learning, giving users control over analysis.
Nickel-zinc hydroxy salts with varying amounts of octahedral Zn 2+ : trends in stability and selectivity in anion exchange reaction

Nickel-zinc hydroxy acetates with varying amounts of octahedral zinc, Ni(3-x)Zn(2+x)(OH)8(OAc)2·mH2O, with x varying from 0 to 2, have been synthesized. The crystallographic ‘a’ parameter increases linearly with octahedral zinc content in the series. While the thermal stability is almost the same for the entire series of compounds, the stability of the compound in the alkaline medium increases with a decrease in octahedral zinc content. The selectivity for chloride ion from a mixture of chloride and bromide ions increases linearly with an increase in octahedral zinc content. The stability of Ni-Zn hydroxy acetate in alkaline medium decreases with increased octahedral substitution of Zn2+, while its selectivity for chloride in anion exchange increases.
Item development, internal consistency, and known-groups validity of the Self-Directed Mobility Scale

Purpose: The aims of the current study include to: (1) describe the item development; and (2) begin the process of establishing the internal consistency and known-groups validity of the Self-Directed Mobility Scale. The purpose of the scale is to assess paediatric physical and occupational therapists' views towards self-directed mobility and their perceived ability and intentions to advocate for children's access to self-directed mobility.Methods: Three individuals with expertise in kinesiology, psychology, paediatric rehabilitation, and disability studies served as the expert panel for item development. Four samples were included to determine internal consistency and known-groups validity: 350 physical therapists, 89 occupational therapists, 279 kinesiology undergraduate students, and 528 health and wellness undergraduate students.Results: The internal consistency was above the acceptable level of 0.70 (range = 0.72-0.77) for all samples when two items regarding promoting other motor skills prior to powered mobility use and the temporary use of a mobility device were removed. Known-groups validity was established between all samples.Conclusions: The Self-Directed Mobility Scale appears to be a valid tool for assessing views of self-directed mobility and mobility advocacy intentions in paediatric physical and occupational therapists, as well as undergraduate students. Future work should examine the internal consistency based on study sample to ensure the (> 0.70) acceptable Cronbach's alpha level is met.Implications for rehabilitationThe Self-Directed Mobility Scale is a viable measurement tool to assess views of self-directed mobility and mobility advocacy intentions of pediatric physical and occupational therapists.In combination with other measures, the Self-Directed Mobility Scale may be used in future rehabilitation research to evaluate factors associated with provision of mobility technology to children with disabilities.
Choline Content of Term and Preterm Infant Formulae Compared to Expressed Breast Milk-How Do We Justify the Discrepancies?

Choline/phosphatidylcholine concentrations are tightly regulated in all organs and secretions. During rapid organ growth in the third trimester, choline requirement is particularly high. Adequate choline intake is 17-18 mg/kg/day in term infants, whereas ~50-60 mg/kg/day is required to achieve fetal plasma concentrations in preterm infants. Whereas free choline is supplied via the placenta, other choline carriers characterize enteral feeding. We therefore quantified the concentrations and types of choline carriers and choline-related components in various infant formulae and fortifiers compared to breast milk, and calculated the supply at full feeds (150 mL/kg/day) using tandem mass spectrometry. Choline concentration in formula ranged from values below to far above that of breastmilk. Humana 0-VLB (2015: 60.7 mg/150 mL; 2020: 27.3 mg/150 mL), Aptamil-Prematil (2020: 34.7 mg/150 mL), Aptamil-Prematil HA (2020: 37.6 mg/150 mL) for preterm infants with weights 1800 g, comprised the highest values in formulae studied. Formulae mostly were rich in free choline or phosphatidylcholine rather than glycerophosphocholine and phosphocholine (predominating in human milk). Most formulae (150 mL/kg/day) do not supply the amounts and physiologic components of choline required to achieve fetal plasma choline concentrations. A revision of choline content in formulae and breast milk fortifiers and a clear declaration of the choline components in formulae is required to enable informed choices.
Tackling Indeterminacy in Overlapping Generations Model

The overlapping generations economy may have a continuum of equilibria. Previous studies have been largely confined to the local analysis that linearizes the model around the steady state. However, what is true of the linearized system only applies for an unknown-sized open neighborhood of the steady state. In this paper I develop a method to diagnose the indeterminacy in overlapping generations models by computing the set of all equilibria. I also provide a procedure to simulate the economy with indeterminate equilibrium.
Natural information, factivity and nomicity

Biological and cognitive sciences rely heavily on the idea of information transmitted between natural events or processes. This paper critically assesses some current philosophical views of natural information and defends a view of natural information as Nomic and Factive. Dretske (Knowledge the flow of information/Fred Dretske, MIT Press Cambridge, Mass, 1981) offered a Factive view of information, and recent work on the topic has tended to reject this aspect of his view in favor of a non-Factive, probabilistic approach. This paper argues that the reasoning behind this move to non-Factivity is flawed and mixes up different problems with Dretske’s original view. I show that one of these problems—strictness—has to do with Nomicity rather than Factivity. The other problem—reference class ambiguity—is not solvable just in terms of a theory of natural information. On the Dretske-inspired view I defend, natural information is Factive and Nomic but is insufficient to determine the cognitive or biological content of a natural process. In sum I present an examination what natural information is and what role it can (and cannot) play in our understanding of living and thinking things.
Risk factors for postdischarge venous thromboembolism among bariatric surgery patients and the evolving approach to extended thromboprophylaxis with enoxaparin.

Abstract Background Venous thromboembolism (VTE) is one of the most common causes of postoperative mortality following bariatric surgery. The majority of VTE events occur after discharge from the hospital. Little consensus exists regarding who should receive extended enoxaparin thromboprophylaxis or how they should be dosed, namely whether to use weight-based or BMI-stratified dosing strategies. Objectives Provide an overview of the risk factors associated with VTE in procedures among bariatric patients including the use of predictive tools to stratify risk and the various approaches to enoxaparin chemoprophylaxis in obesity. Setting Multiple centers. Methods A review of the literature identified studies evaluating risk factors for VTE including demographic characteristics, co-morbidities, and operative factors. The use of calculators to stratify patients by risk and approaches to extended thromboprophylaxis in obesity were evaluated as well. Results VTE was associated with increased age, weight, male sex, and prior history of VTE, all frequently included in risk calculators. Outside of those major risk factors, there is little consensus about the importance of patient diagnoses. Weight-based dosing was often superior to standardized dosing in studies across disciplines in generating target anti-Xa levels however there is no consistent association of reduced risk of VTE with therapeutic anti-Xa levels. Conclusions Risk calculators may be a valuable tool for identifying patients at high-risk for VTE, but their efficacy depends on the rating algorithm and inclusion of various risk factors and is methodologically limited by prophylactic interventions. Future work should consider if biochemical factors should be included in patient stratification approaches in particular when defining the ideal chemoprophylaxis approach. Transparency and consistency in data collection and reporting is needed to better assess and inform the ideal dosing strategy to prevent VTE following bariatric surgery.
Immunomodulatory Contribution of Mast Cells to the Regenerative Biomaterial Microenvironment

Bioactive immunomodulatory biomaterials have shown promise for influencing the immune response to promote tissue repair and regeneration. Macrophages and T cells have been associated with this response; however, other immune cell types have been traditionally overlooked. In this study, we investigated the role of mast cells in the regulation of the immune response to decellularized biomaterial scaffolds using a subcutaneous implant model. In mast cell-deficient mice, there was dysregulation of the expected M1 to M2 macrophage transition typically induced by the biomaterial scaffold. Polarization progression deviated in a sex specific manner with an early transition to an M2 profile in female mice, while the male response was unable to properly transition past a pro-inflammatory M1 state. Both were reversed with adoptive mast cell transfer. Further investigation of the later stage immune response in male mice determined a greater sustained pro-inflammatory gene expression profile including the IL-1 cytokine family, IL-6, alarmins, and chemokines. These results highlight mast cells as another important cell type that influences the immune response to pro-regenerative biomaterials.
Using Coherence Analysis to Characterize Self-Regulated Learning Behaviours in Open-Ended Learning Environments

Researchers have long recognized the potential benefits of using open-ended computer-based learning environments (OELEs) to study aspects of students’ self-regulated learning behaviours. However, measuring self-regulation in these environments is a difficult task. In this paper, we present our work in developing and evaluating coherence analysis (CA), a novel approach to interpreting students’ learning behaviours in OELEs. CA focuses on the learner’s ability to interpret and apply information encountered while working in the OELE. By characterizing behaviours in this manner, CA provides insight into students’ open-ended problem-solving strategies as well as the extent to which they understand the nuances of their current learning task. To validate our approach, we applied CA to data from a recent classroom study with Betty’s Brain . Results demonstrated relationships between CA-derived metrics, prior skill levels, task performance, and learning. Taken together, these results provide insight into students’ SRL processes and suggest targets for adaptive scaffolds to support students’ development of science understanding and open-ended problem solving skills.
Short-term policy in open semi-industrialized economies: The narrow limits of the possible

Abstract This paper develops a model to analyze short-term policy alternatives in semi-industrialized countries. The major points raised are the following: (i) There are two sectors, producing traded and non-traded goods. The latter is characterized by a fairly low elasticity of substitution and a high relative labor share. If the elasticity of substitution in the traded goods sector has an econometrically reasonable value, then short-run improvements in both the labor share and real income may well call for revaluation of the exchange rate and an increase in home good's price (prices of both goods being measured in wage units). (ii) If excess supply functions have Walrasian stability, such price changes will lead to deterioration in the balance of payments: On the other hand, devaluation-induced improvement in the balance of payments (with constant government expenditure) can lead to an improvement in real income, but reduces the labor share. (iii) If the economy is formally unstable, due to capitalists and laborers concentrating their expenditure demands respectively on the goods intensive in factor payments to themselves, then balance of payments improvement in a comparative static analysis may entail reductions in both real income and the labor share. (iv) If the additional realistic assumption is made that elasticities of excess supply functions for the two goods with respect to the interest rate are quite low, then in general improvement of all three targets (real income, balance of payments, and income distribution) will be unattainable. If in addition the government cannot finance expenditure changes by anything but money supply changes, then in general only one target variable can be attained. (v) Numerical sensitivity analysis based on Chilean data indicates that these (and other) rather pessimistic results hold for fairly wide ranges of ‘plausible’ parameter values, as long as the model's short-run Keynesian assumptions are maintained.
A novel geometric multiscale approach to structured dictionary learning on high dimensional data

Adaptive dictionary learning has become a hot-topic research field during the past decade. Though several algorithms have been proposed and achieved impressive results, they are all computationally intensive due to the lack of structure in their output dictionaries. In this paper we build upon our previous work and take a geometric approach to develop better, more efficient algorithms that can learn adaptive structured dictionaries. While inheriting many of the advantages in the previous construction, the new algorithm better utilizes the geometry of data and effectively removes translational invariances from the data, thus able to produce smaller, more robust dictionaries. We demonstrate the performance of the new algorithm on two data sets, and conclude the paper by a discussion of future work.
The Emergence of Thought

A phenomenon “emerges” when a concept is instantiated for the first time: hence emergence is relative to a set of concepts. Propositional thought and language emerge together. It is proposed that the degree of complexity of an object language relative to a given metalanguage can be gauged by the number of ways it can be translated into that metalanguage: in analogy with other forms of measurement, the more ways the object language can be translated into the metalanguage, the less powerful the conceptual resources of the object language.
Comparison of TRMM precipitation radar and microwave imager rainfall retrievals in tropical cyclone inner cores and rainbands

[1] Tropical Rainfall Measuring Mission (TRMM) rainfall retrieval algorithms are evaluated in tropical cyclone (TC) inner cores (IC), inner bands (IB), and outer rainbands (OB). In total, 1329 IC, 2149 IB, and 4627 OB storm regions are analyzed using data from a 12-year TRMM Tropical Cyclone Precipitation Feature (TCPF) database containing 1013 TCs viewed from December 1997 to December 2009. Attention is focused on the difference between the Precipitation Radar (PR) 2A25 and the TRMM Microwave Imager (TMI) 2A12 rainfall algorithms. The PR 2A25 produces larger mean rain rates than the TMI 2A12 in inner cores and inner bands, with the greatest difference occurring in hurricanes. This discrepancy is caused mostly by the TMI 2A12 significantly underestimating regions of moderate to heavy rain >15 mm hour−1 or when the PR reflectivity is greater than 30 dBZ. The TMI 2A12 rain rates are most closely related to the percentage coverage of 85 GHz polarization-corrected brightness temperature (PCT) <225 K in the IC and 85 GHz PCT <250 K in the IB and OB. These convective parameters are good predictors of the mean TMI 2A12 rain rate, but significant ice scattering is not always present in areas of heavy rain that are often widespread in TC inner regions. As a result, the TMI 2A12 algorithm may poorly measure the rain rate, particularly in the inner core of hurricanes.
A nanoparticle depot formulation of 4-(N)-stearoyl gemcitabine shows a strong anti-tumour activity.

Depot formulation as a carrier for cytotoxic chemotherapeutic drugs is not well studied. The objective of this study is to test the feasibility of using a subcutaneous depot formulation to administer a cytotoxic anti-cancer drug for systemic therapy.A fatty-acid amide prodrug of the nucleoside analogue gemcitabine (4-(N)-stearoyl gemcitabine (GemC18)) was incorporated into poly(lactic-co-glycolic acid) (PLGA) nanoparticles or microspheres. A GemC18 solution was used as a control. The anti-tumour activity was evaluated after subcutaneous injection of the different formulations in C57BL/6 mice with pre-established model tumours. The clearance of GemC18 from the injection site was determined by measuring the percentage of GemC18 remaining at the injection site at different times after the injection.The depot formulation based on the GemC18-loaded PLGA nanoparticles showed the strongest anti-tumour effect, likely due to the proper 'release' of GemC18 from the injection site.It is feasible to dose cytotoxic anti-cancer drugs as a nanoparticle-based depot formulation, especially when combined with an advanced prodrug strategy.
Multicast Extensions to the Location-Prediction Based Routing Protocol for Mobile Ad Hoc Networks

We propose multicast extensions to the location prediction-based routing protocol (NR-MLPBR and R-MLPBR) for mobile ad hoc networks to simultaneously reduce the number of tree discoveries, number of links and the hop count per path from the source to the multicast group. The multicast extensions work as follows: Upon failure of a path to the source, a receiver node attempts to locally construct a global topology using the location and mobility information collected during the latest global broadcast tree discovery. NR-MLPBR predicts a path that has the minimum number of hops to the source and R-MLPBR predicts a path to the source that has the minimum number of non-receiver nodes. If the predicted path exists in reality, the source accommodates the path as part of the multicast tree and continues to send the multicast packets in the modified tree. Otherwise, the source initiates another global broadcast tree discovery.
Robust packet image transmission by wavelet coefficient dispersement

We present a packetization method for robust image transmission over packet erasure channels. The packets are formed in such a way that the image information is spread over different frequency bands and spatial locations to avoid complete disruption of certain image blocks in case of a packet loss. Experimental results are provided to demonstrate the performance of this method.
Cardiolipin-Specific Phospholipase D Activity in Haemophilus parainfluenzae

A highly active phospholipase D that is specific for cardiolipin was detected in the gram-negative bacterium Haemophilus parainfluenzae. Previously reported phospholipase D preparations have come exclusively from higher plants. The bacterial enzyme hydrolyzed cardiolipin to phosphatidyl glycerol and phosphatidic acid. During the incubation, phosphatidic acid disappeared. Phosphatidyl ethanolamine, methylated phosphatidyl ethanolamines, phosphatidyl choline, and phosphatidyl glycerol were not hydrolyzed when cardiolipin was rapidly hydrolyzed.
Spatial relationship between the intrinsic metal in the β subunit and cysteine-132 in the σ subunit of Escherichia coli RNA polymerase: A resonance energy transfer study

Abstract Fluorescence excited-state energy transfer measurements were carried out between the N-(1-pyrene)maleimide (PM)-labeled σ subunit and Co in the β subunit of Co-Zn RNA polymerase (RPase). σ subunit with or without PM labeling was cleaved with 2-nitro-5-thiocyanobenzoic acid, and the reaction products were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. One molecule of the fluorescent probe (PM) was found to be attached to the cysteine-132 residue of the σ subunit. When excited at 340 nm, the fluorescence emission bands from 380 to 420 nm of PM-labeled σ overlap with the charge transfer absorption band of Co-Zn RPase around 400 nm. Based on Forster's equation, the R0 values for the donor-acceptor pair were calculated to be 21.5 and 22 A in the absence and presence of template analog (dA-dT)60, respectively. Using these R0 values and the observed energy transfer efficiencies, the distance between the cysteine-132 of the σ subunit and Co located at the initiation site of the β subunit was calculated to be 22 A with or without the template present, indicating that no major conformational change of the enzyme was induced upon template binding. However, a small but significant change in the above distance was observed upon the addition of ATP to RPase in the presence (dA-dT)60 but not in the absence of (dA-dT)60 template. The biological implications of these observations are discussed.
Depressives syndromes in a primary care setting: Evaluation, classification, and outcome

Abstract Fifteen percent of the general population may experience a major disorder of mood during their lives. 1 Their care falls to the greatest degree upon the primary physician. 2 A general practitioner may be chosen for the first contact by an estimated 88% of individuals fearing an experiencing psychologic disturbance. 3 As many as 63% of community based mentally ill ( n = 490,000) may receive their psychiatric treatment from a general practitioner. 4 This prevalence is further enhanced by the observation that psychiatric patients represents a high medical utilization group when contrasted with nonpsychiatric controls. 5 Since the depressive syndrome is of diverse etiology, and may present under the guise of a physical complaint, a comprehensive evaluation should include a personal and family history, physical and mental status examination, and appropriate laboratory tests. While family practitioners may spend from 17% to 27% of patients care time dealing with emotionally related problems, 6 some 60% of the American Academy of Family Physicians reported “insufficient training in medical school” to deal with their patients' emotional problems. A comprehensive data base (Table 1) was contrasted with the practices of second and third year family practice residents by a prospective study of recently diagnosed “depression” at a community primary care center.
Lead analysis by anti-chelate fluorescence polarization immunoassay.

Lead concentrations were determined by a fluorescence polarization immunoassay (FPIA) method that uses polyclonal antibodies raised against the lead(II) chelate of ethylenediamine-N,N,N‘,N‘-tetraacetic acid (EDTA). The technique is based on competition for a fixed concentration of antibody binding sites between Pb−EDTA, formed by treating the sample with excess EDTA, and a fixed concentration of a fluorescent analogue of the Pb−EDTA complex. The objective was to correlate results obtained by FPIA with those produced by conventional atomic spectroscopy analysis of soils, solid waste leachates (produced by the Toxicity Characteristic Leachate Procedure; TCLP), airborne dust, and drinking water. Linear regression analysis of FPIA results for 138 soil samples containing 0−3094 ppm Pb(II) by flame atomic absorption spectroscopy and 40 TCLP extracts containing 0−668 ppm Pb(II) by inductively coupled plasma atomic emission spectroscopy produced correlation coefficients (r2) of 0.96 and 0.93, respectively. Pilot ...
Minimax Estimation of a Mean Vector for Distributions on a Compact Set

Minimax estimation procedures for the mean vector of a distribution on a compact set under squared error type loss functions are considered. In particular, a Dirichlet process prior is used to show that a linear function of is a minimax estimator in the class of all measurable estimators and all possible distributions. This effort extends some earlier work of Buhlmann to a more general setting.
Species-level phylogenetic revision of the Ordovician orthide brachiopod Glyptorthis from North America

Species of the orthide brachiopod genus Glyptorthis occur as common constituents of Late Ordovician benthic marine faunas, particularly in Laurentia. A phylogenetic analysis of 23 North American species of Glyptorthis was conducted to inform a systematic revision and ascertain evolutionary relationships amongst species. Both discrete and continuous characters, from which character states were determined using statistical methods, were utilized within a maximum parsimony approach. Glyptorthis maquoketensis is recognized as a distinct species of Glyptorthis rather than a subspecies of G. insculpta. Glyptorthis virginica is herein synonymized with G. uniformis. Several species of Glyptorthis became widely distributed via dispersal events during the evolution of the clade. The revised phylogenetic topology provides structure to interpret biogeographical patterns within the genus. For example, Glyptorthis insculpta participated in the Late Ordovician Richmondian Invasion into the Cincinnati Basin. The recovere...
An ocean bottom, microprocessor based seismometer

We describe the design and construction of an ocean bottom seismometer configured as a computer, based on an Intersil IM6100 microprocessor plus appropriate peripheral devices. The sensors consist of triaxial 1 Hz seismometers and a hydrophone, each sensor channel being filtered prior to digitizing so that typical noise spectra are whitened. Digital data are recorded serially on magnetic tape. The instrument is placed on the ocean bottom by allowing it to fall freely from just below the surface. An acoustic system allows precise determination of instrument position, acoustic recall, and transmission of operational information to the surface. Release from an expendable anchor is accomplished by redundant pyrotechnic bolts which can be fired by acoustic command or by precision timers.
Promoting interdisciplinarity through climate change education

Climate change is a complex scientific and social problem. Effectively dealing with it presents an immense challenge, yet educating students about it offers educators in science, technology, engineering and mathematics (STEM) fruitful opportuni - ties for promoting interdisciplinarity, retaining talented young people in STEM fields and enhancing multiple literacies of all students. We offer three illustrative examples of interdisciplinary climate change-related STEM education projects. Each of these models is designed deliberately for implementation in the first two years of collegiate-level STEM courses; thus, they may be employed in both four- and two-year institutions. The scientific community can use climate change education opportunities to help further transform STEM education in the US and increase production of high-quality STEM graduates.
The relationship between peripapillary crescent and axial length: implications for differential eye growth

We evaluated the relationship between the size of the peripapillary crescent and the axial length (AL) of the eye as well as the fine structure of the peripapillary crescent in selected eyes. Infrared fundus imaging and spectral domain optical coherence tomography (SDOCT) (Spectralis HRA + OCT, Heidelberg Engineering, Germany) centered at the fovea were performed on 72 healthy adults. On the infrared fundus images, we measured (a) the distance between the foveola and the temporal edge of the optic disc (FOD) and (b) the distance between the foveola and the temporal edge of the peripapillary crescent (FOC) (if present). A peripapillary crescent presented at the nasal margin of the disc in 64% of the subjects. The FOD and FOC were 4.22 mm ± 0.46 and 3.97 mm ± 0.25, respectively. Only the FOD was significantly correlated with axial length. As AL increased by 10%, the FOD increased by 13%, the outer neural retina only expanded by 4% (as indicated by the FOC). This result emphasizes that retinal stretching may not mirror scleral growth, and the existence in some eyes of a difference between the photoreceptor margin and retinal pigment epithelium (RPE) margin suggests that within the retina there could be slippage during eye growth.
Evidence for Photorespiration in Tropical Grasses

Sugarcane leaves respired in full light and the CO2 evolved could be detected in sorghum or miaze photosynthesizing in the same closed system. A combination of radiometric and infra-red gas analysis techniques allowed the estimation of photorespiration (total CO2 evolution in light) and photosynthesis at increasing light intensities and of dark respiration. Rates of CO2 evolution approaching those of temperate zone plants occurred at lower light intensities but rapidly decreased with higher light. Smaller but significant quantities of 14CO2 were released even at intensities approximating full sunlight in leaves of maize, sorghum and sugarcane. Highly efficient CO2 capture may explain the low rates of photorespiration at high light intensities.
Long-term variations of Western Sahelian monsoon rainfall and intense U.S. landfalling hurricanes

Abstract Western Sahelian rainfall during the primary rainy season of June through September is shown to he significantly associated with concurrent intense U.S. landfalling hurricanes during the last 92 years. The meet intense hurricanes (i.e., Saffir–Simpson Scale Category 3, 4, or 5) have an especially strong relationship with Sahelian rainfall, whereas weaker hurricanes show little or no association. The hurricane-Sahelian rainfall association is most evident along the U.S. East Coast but is negligible in the U.S. Gulf Coast region.
Angular distribution of decay electrons from the 6p resonance excitations in xenon

Angular distributions for the electrons produced by the decay of the 4d\ensuremath{\rightarrow}6p excitations in xenon have been measured using an undulator radiation source. The resolution employed in the experiment has allowed us to derive separate \ensuremath{\beta} values for features which had not been isolated previously, as well as to determine \ensuremath{\beta} values for previously unreported lines. Comparison is made between existing experimental and theoretical results. \textcopyright{} 1996 The American Physical Society.
Monoacylglycerol accumulation in low and high density lipoproteins during the hydrolysis of very low density lipoprotein triacylglycerol by lipoprotein lipase.

Abstract We have demonstrated that low and high density lipoproteins from monkey plasma are capable of accepting and accumulating monoacylglycerol that is formed by the action of lipoprotein lipase on monkey lymph very low density lipoproteins. Furthermore, the monoacylglycerol that accumulates in both low and high density lipoproteins is not susceptible to further hydrolysis by lipoprotein lipase but is readily degraded by the monoacylglycerol acyltransferase of monkey liver plasma membranes. These observations suggest a new mechanism for monoacylglycerol transfer from triacylglycerol rich lipoproteins to other lipoproteins. In addition, the finding that monoacylglycerol bound to low and high density lipoprotein is degraded by the liver enzyme but not lipoprotein lipase lends support to the hypothesis that there are distinct and consecutive extrahepatic and hepatic stages in the metabolism of triacylglycerol in plasma lipoproteins.
Rate Constants for D + C2H2 → C2HD + H at High Temperature: Implications to the High Pressure Rate Constant for H + C2H2 → C2H3

The reflected shock tube technique with D atom atomic resonance absorption spectrometry (ARAS) detection has been used to study the bimolecular reaction, D + C{sub 2}H{sub 2} {yields} C{sub 2}HD + H. D atoms were produced from the thermal decomposition of C{sub 2}D{sub 5}I above {approx}1150 K. The initially formed C{sub 2}D{sub 5} radicals rapidly decompose to give D + C{sub 2}D{sub 4}. Rate constant values were obtained from both reactant and product hydrogen atom measurements, and these were found to be identical within experimental error. The title reaction proceeds through a vibrationally excited vinyl radical, and the equivalence of results based on reactant and product measurements suggests that radical stabilization is negligible over the temperature and pressure ranges of the experiments. For 1100 {<=} T {<=} 1630 K, the results can be described by the linear-least-squares Arrhenius expression: k = (2.77 {+-} 0.45) x 10{sup -10} exp(-3051 {+-} 210 K/T) in units of cm{sup 3} molecule{sup -1} s{sup -1}, with the one standard deviation of the values from the equation being {+-}10.7%. Application of RRKM theory with negligible stabilization shows that k = k{sub D{infinity}}{l_angle}k{sub f{var_epsilon}}/(k{sub f{var_epsilon}}+ k{sub b{var_epsilon}}){r_angle} where the k{sub i{var_epsilon}}'s refer to RRKM evaluated specific ratemore » constants for forward and backward dissociations, and k{sub D{infinity}} is the high-pressure limiting rate constant for D addition to acetylene. Hence, the present measurements coupled with earlier measurements and modern ab initio potential energy determinations allow for specification of the high-pressure limiting rate constants. The same model can then be used for the protonated reaction, H + C{sub 2}H{sub 2}, where a considerable ambiguity has existed for about 30 years.« less
Enterobactin synthetase-catalyzed formation of P(1),P(3)-diadenosine-5'-tetraphosphate.

The EntE enzyme, involved in the synthesis of the iron siderophore enterobactin, catalyzes the adenylation of 2,3-dihydroxybenzoic acid, followed by its transfer to the phosphopantetheine arm of holo-EntB, an aryl carrier protein. In the absence of EntB, EntE catalyzes the formation of Ap4A, a molecule that is implicated in regulating cell division during oxidative stress. We propose that the expression of EntE during iron starvation produces Ap4A to slow growth until intracellular iron stores can be restored.
A methodology to investigate size scale effects in crystalline plasticity using uniaxial compression testing

Abstract A methodology for performing uniaxial compression tests on samples having micron-size dimensions is presented. Sample fabrication is accomplished using focused ion beam milling to create cylindrical samples of uniform cross-section that remain attached to the bulk substrate at one end. Once fabricated, samples are tested in uniaxial compression using a nanoindentation device outfitted with a flat tip, and a stress–strain curve is obtained. The methodology can be used to examine the plastic response of samples of different sizes that are from the same bulk material. In this manner, dimensional size effects at the micron scale can be explored for single crystals, using a readily interpretable test that minimizes imposed stretch and bending gradients. The methodology was applied to a single-crystal Ni superalloy and a transition from bulk-like to size-affected behavior was observed for samples 5 μm in diameter and smaller.
Electron transfer between a tyrosyl radical and a cysteine residue in hemoproteins: spin trapping analysis.

We investigated electron transfer between a tyrosyl radical and cysteine residue in two systems, oxyhemoglobin (oxyHb)/peroxynitrite/5,5-dimethyl-1-pyrroline N-oxide (DMPO) and myoglobin (Mb)/hydrogen peroxide/DMPO, using a combination of techniques including ESR, immuno-spin trapping (IST), and ESI/MS. These techniques show that the nitrone spin trap DMPO covalently binds to one or more amino acid radicals in the protein. Treating oxyHb with peroxynitrite and Mb with H2O2 in the presence of a low DMPO concentration yielded secondary Cys-DMPO radical adduct exclusively, whereas in the presence of high DMPO, more of the primary Tyr-DMPO radical adduct was detected. In both systems studied, we found that, at high DMPO concentrations, mainly tyrosyl radicals (Hb-Tyr42/Tyr24 and Mb-Tyr103) are trapped and the secondary electron-transfer reaction does not compete, whereas in the presence of low concentrations of DMPO, the secondary reaction predominates over tyrosyl trapping, and a thiyl radical is formed and ...
Nitrogenase II. Changes in the EPR signal of Component I (iron-molybdenum protein) of Azotobacter vinelandii nitrogenase during repression and derepression

Abstract The purified, native iron-molybdenum protein (Component I) of Azotobacter vinelandii nitrogenase shows EPR signals at g values of 4.32, 3.65, and 2.01, when observed below 40° K. The resonances near g = 4.32 and 3.65 are unobscured when whole nitrogen-fixing cells are observed, and we have compared the appearance and disappearance of these resonances with nitrogenase activity as well as Component I protein determined immunochemically, during derepression and repression of nitrogenase. The characteristic resonances are absent in cells grown on ammonium salts. During derepression the activity, EPR signal, and cross-reacting material appear and pass through a maximum in parallel. During repression the immunochemically-detectable protein decays inversely with cell growth, while the activity and signal are depressed considerably more rapidly. This suggests that a short-term control mechanism, including the substantial alteration of the paramagnetic center of Component I without elimination of the antigenic moiety, is responsible for rapid repression of nitrogenase by ammonia. EPR signals similar to those of Component I in Azotobacter were also observed at low temperatures in nitrogen-fixing cells of Clostridium pasteurianum, Klebsiella pneumoniae, and Bacillus polymyxa, suggesting that in vivo studies of Component I of nitrogenase may be feasible generally.
Biomechanical evaluation of the ligamentous stabilizers of the scaphoid and lunate: part III.

Purpose This study continued our previous investigations of the ligaments stabilizing the scaphoid and lunate in which we examined the scapholunate interosseous ligament, the radioscaphocapitate, and the scaphotrapezial ligament. In this current study, we examined the effects of sectioning the dorsal radiocarpal ligament, dorsal intercarpal ligament, scapholunate interosseous ligament, radioscaphocapitate, and scaphotrapezial ligaments. In the current study, the scapholunate interosseous ligament, radioscaphocapitate, and scaphotrapezial ligaments were sectioned in a different order than performed previously. Methods Three sets of 8 cadaver wrists were tested in a wrist joint motion simulator. In each set of wrists, only 3 of the 5 ligaments were cut in specific sequences. Each wrist was moved in continuous cycles of flexion-extension and radial-ulnar deviation. Kinematic data for the scaphoid and lunate were recorded for each wrist in the intact state, after the 3 ligaments were sectioned in various sequences and after the wrist was moved through 1,000 cycles of motion. Results Dividing the dorsal intercarpal or scaphotrapezial ligaments did not alter the motion of the scaphoid or lunate. Dividing the dorsal radiocarpal ligament alone caused a slight statistical increase in lunate radial deviation. Dividing the scapholunate interosseous ligament after first dividing the dorsal intercarpal, dorsal radiocarpal, or scaphotrapezial ligaments caused large increases in scaphoid flexion and lunate extension. Conclusions Based on these findings, we concluded that the scapholunate interosseous ligament is the primary stabilizer and that the other ligaments are secondary stabilizers of the scapholunate articulation. Dividing the dorsal radiocarpal, dorsal intercarpal, or scaphotrapezial ligaments after cutting the scapholunate interosseous ligament produces further changes in scapholunate instability or results in changes in the kinematics for a larger portion of the wrist motion cycle.
Regulation of Territorial Behavior in the Sedentary Song Sparrow, Melospiza melodia morphna

Male song sparrows (Melospiza melodia morphna) of western Washington State show year-round territoriality. Although territorial aggression during the breeding season was accompanied by high circulating levels of luteinizing hormone (LH) and testosterone (T), similar aggression in the non-breeding season occurred when gonadal hormone levels were basal. Experimental removal of territorial males in autumn resulted in new males taking over the territory within a few days. These males had basal levels of LH and T despite establishing a new territory and the accompanying high level of aggression. There was also no difference in plasma levels of corticosterone in replacement versus established territorial males suggesting that social stress was not a factor. To test the possibility that low levels of gonadal steroids, or potentially some gonadal hormone not measured here, might regulate territorial aggression in the non-breeding season, free-living male song sparrows were castrated in early autumn and their aggressive territorial behavior was quantified by a simulated territorial intrusion (STI). Castrates showed the same aggressive responses to STI as controls indicating that establishment and maintenance of a territory was not dependent upon hormones of gonadal origin. Castrated males retained territories throughout the autumn and winter and even into the following breeding season. Further experiments were conducted to establish a role, if any, for T in territorial behavior in this species. During the breeding season when males had high levels of T, the responses to STI continued after the stimuli (caged conspecific male and tape-recorded songs) were withdrawn. Some males continued to patrol the territory and sang for long periods after STI. In contrast, males exposed to STI in autumn showed a strong aggressive response during the challenge, but then territorial aggression abated rapidly when the stimuli were withdrawn. Implants of T into males in autumn reinstated the high level of aggression after withdrawal of STI in a manner similar to that seen during the breeding season. These data suggest that in M. m. morphna T does not activate territorial aggression per se, but may increase the intensity of an aggressive response to STI, and persistence of the behavior after STI is withdrawn.
Approximate selections for upper semicontinuous convex valued multifunctions

Soit X un expace metrique et soit Y un espace lineaire norme. Soit Γ:X→CL(Y) une multifonction u.s.c. munie des proprietes suivantes: 1) Γ applique des points isoles de X sur des singletons; 2) pour chaque x∈X, Γ(x) est un ensemble convexe separable. Alors il existe une 1-fonction de classe de Baire f:X→Y dont la multifonction ensemble limite est u.s.c. et a valeur convexe telle que δ[f,Γ]≤e. Si les valeurs de Γ sont chacunes totalement bornees, alors f peut etre choisie continue
Use of propranolol to treat multicentric airway haemangioma.

Objective To report our experience of using propranolol to treat an infantile airway haemangioma. Methods A five-week-old girl presented with upper airway obstruction. Having started systemic steroids, concurrent propranolol therapy was commenced. Propranolol was given with close monitoring of the blood pressure, pulse and capillary glucose level. The dose of propranolol was gradually increased to 2 mg/kg total daily dose, with simultaneous reduction and withdrawal of steroids. Results Prior to propranolol treatment, laryngotracheobronchoscopy revealed an extensive haemangioma extending from the posterior pharyngeal wall to the subglottis. Following initiation of propranolol, a dramatic reduction in tumour bulk was seen on repeated laryngotracheobronchoscopy within 10 days of treatment. Eight months on, the patient remained asymptomatic on propranolol, with no endoscopic evidence of disease apart from mild telangiectasia. Conclusion Haemangiomas of the airway can cause obstruction which may potentially be life-threatening. This case demonstrates the potential of propranolol to become a valuable therapeutic option in such clinical situations.
Early forest dynamics in stand-replacing fire patches in the northern Sierra Nevada, California, USA

There is considerable concern over the occurrence of stand-replacing fire in forest types historically associated with low- to moderate-severity fire. The concern is largely over whether contemporary levels of stand-replacing fire are outside the historical range of variability, and what natural forest recovery is in these forest types following stand-replacing fire. In this study we quantified shrub characteristics and tree regeneration patterns in stand-replacing patches for five fires in the northern Sierra Nevada. These fires occurred between 1999 and 2008, and our field measurements were conducted in 2010. We analyzed tree regeneration patterns at two scales: patch level, in which field observations and spatial data were aggregated for a given stand-replacing patch, and plot level. Although tree regeneration densities varied considerably across sampled fires, over 50 % of the patches and approximately 80 % all plots had no tree regeneration. The percentage of patches, and to a greater extent plots, without pine regeneration was even higher, 72 and 87 %, respectively. Hardwood regeneration was present on a higher proportion of plots than either the pine or non-pine conifer groups. Shrub cover was generally high, with approximately 60 % of both patches and individual plots exceeding 60 % cover. Patch characteristics (size, perimeter-to-area ratio, distance-to-edge) appeared to have little effect on observed tree regeneration patterns. Conifer regeneration was higher in areas with post-fire management activities (salvage harvesting, planting). Our results indicate that the natural return of pine/mixed-conifer forests is uncertain in many areas affected by stand-replacing fire.