cssi/SciSciGPT-SciSciNet huggingface dataset:
Surface Acetylation of Polyamidoamine (PAMAM) Dendrimers Decreases Cytotoxicity while Maintaining Membrane Permeability

Improving the oral bioavailability of therapeutic compounds remains a challenging area of research. Polyamidoamine (PAMAM) dendrimers are promising candidates for oral drug delivery due to their well-defined compact structure, versatility of surface functionalities, low polydispersity, and ability to enhance transepithelial transport. However, potential cytotoxicity has hampered the development of PAMAM dendrimers for in vivo applications. In this article, we have systematically modified the surface groups of amine-terminated PAMAM dendrimers with acetyl groups. The effect of this modification on cytotoxicity, permeability, and cellular uptake was investigated on Caco-2 cell monolayers. Cytotoxicity was reduced by more than 10-fold as the number of surface acetyl groups increased while maintaining permeability across the cell monolayers. Furthermore, a decrease in nonspecific binding was evident for surface-modified dendrimers compared to their unmodified counterparts. These studies point to novel strategies for minimizing PAMAM dendrimer toxicity while maximizing their transepithelial permeability.
Experimental models for cellular radiation targets: LET, RBE and radioprotectors.

The topics of this presentation are: a brief review of the early research, the ideas it stimulated and the ways they are used in current efforts to explain cellular radiosensitivity; an analysis of the strengths and weaknesses of two experimental models used in vitro for simulating the induction of double strand breaks (DSB) and single strand breaks (SSB) in situ. Note that when alkali is used to denature cellular DNA for the determination of strand breaks, both overt SSB and the SSB that result from DSB in the denaturation process are recorded as total strand breaks (TSB). All information is taken from published literature.
A vector form of compensation theorem and its application to boundary-value problems

The paper presents the vector form of the Compensation Theorem and illustrates its application to the formulation of a class of boundary value problems. The above theorem originally stated for electrical networks has previously been extended to electromagnetic problems by Monteath, but only in a scalar form. The subject of discussion of this paper is the generalization of his approach to the vector case.
Relational messages associated with persona‐sharing

This study investigated the assumption that conversations incorporating persona‐sharing would be associated with changes in perceptions of relational messages. Two‐hundred and one participants watched videotapes of male interactants either engaging or not engaging in conversation incorporating persona‐sharing. Results showed that persona‐sharing was associated with increased perceptions of immediacy, intimacy / similarity, and dominance. When an interactant was excluded from persona‐sharing conversation, perceived relational messages directed toward him were seen as less immediate, less intimate, and less dominant relative to being excluded from non‐persona‐sharing conversation.
The damping performance of aluminum-based composites

Metal-matrix composites may offer better damping properties than unreinforced alloys. Because damping properties (and metal-matrix composites) are becoming important in airframe design, the damping capabilities of a number of aluminum-matrix composites were measured over a wide range of frequencies at low strain amplitudes, using a new laser vibrometer technique. Silicon carbide and alumina reinforcements resulted in a material with damping properties similar to that of unreinforced aluminum 6061-T6, but unidirectional and planar-random graphite continuous-fiber reinforcements increased the damping by 5 and 14 times, respectively. The increased damping of the continuous fiber composites is attributed to the absence of interfacial reaction resulting from the high-pressure infiltration method used for their manufacture.
Dispersion in trickle-bed reactors with pulsing gas-liquid down-flow

Abstract Pulsing flow in trickle-bed reactors occurs at high gas and liquid input flow rates. It refers to the periodic passage of liquid rich slug and gas rich pulse down the column. A model based on the combination of the method of characteristics and Monte Carlo simulation of liquid phase dispersion in the slug and the pulse is developed to predict liquid dispersion in a pulsing column packed with non-porous, spherical particles. The predicted Peclet number as a function of Reynolds number shows good agreement with experimental data. In addition, it is found that the pulsing phenomenon does not contribute significantly to dispersion.
After the Glow: Race ambivalence and other educational prognoses

The Right has a long history of questioning the importance of race analysis. Recently, the conceptual and political status of race has come under increased scrutiny from the Left. Bracketing the language of ‘race’ has meant that the discourse of skin groups remains at the level of abstraction and does not speak to real groups as such. As a descriptor, race essentializes identity as if skin color were a reliable way to perceive one's self and group as well as others, and questions the viability of a social struggle based on race. In other words, race is not real and discourses that insist on its objective status are ensnared in reification. The response—equally from the Left—has been to reassert the centrality and changing dynamics of race in education and society. They argue that we need to develop more, rather than less, complex discourses on race. Orientations that attempt to discredit race analysis are therefore unable to dismantle the racial system because they refuse its significance as an autonomous...
Subtractive hybridization identifies chick-cripto, a novel EGF-CFC ortholog expressed during gastrulation, neurulation and early cardiogenesis.

EGF–CFC genes encode a novel class of extracellular, membrane-associated proteins that notably play an important role during vertebrate gastrulation. Whereas the two cysteine-rich domains that characterize these proteins, namely the extracellular EGF-like and the CFC domain, are known to be encoded by two evolutionarily conserved exons, it is generally assumed, based on weak primary sequence identity, that the remaining parts of the protein differ among vertebrates, suggesting that known members of the EGF–CFC family do not represent true orthologs. Here, by characterizing the full cDNA and genomic sequences of a new EGF–CFC gene in chick, and by comparing them with their counterparts in human (CRIPTO), mouse (cripto and cryptic), Xenopus (FRL-1) and zebrafish (one-eyed pinhead), we show that all EGF–CFC genes share an identical genomic organization over the entire coding region. Not only are the central two exons (coding for the EGF-like and CFC motifs) conserved, but also conserved are the total number of exons, their size, their intron phase and their correlation with discrete protein modules, in particular those modules that allow the EGF–CFC motif to become membrane-associated. Therefore, despite apparent divergence between their 5′ and 3′-terminal exons, all known CRIPTO-related genes are structurally orthologous. We named this novel ortholog in bird, chick-cripto. We report the mRNA distribution of chick-cripto, which begins in the epiblast of the gastrula, with a pattern similar to EGF–CFC genes of other vertebrates.
Ventilator-associated infection: the role for inhaled antibiotics.

Purpose of review Despite multiple protocols for the prevention of ventilator-associated pneumonia (VAP), respiratory infections have not been eliminated in the ICU. The profound disruption in both airway integrity and mucociliary clearance caused by the endotracheal tube makes it unlikely there will ever be a zero rate of respiratory infection in critically ill ventilated patients or a 100% cure rate when infection is present. In fact, options for treatment are diminishing as bacteria resistant to most, or in some hospitals all, systemic antibiotics increase in prevalence from our liberal use of systemic antibiotics. Inhaled therapy with proper delivery will result in the high concentrations of antibiotics needed in the treatment of increasingly resistant organisms. Recent findings Data from many recent investigations have focused on inhaled antibiotics as: adjunctive therapy to systemic antibiotic for VAP, monotherapy for VAP, and as monotherapy for ventilator-associated tracheobronchitis. The clinical outcomes of these studies will be reviewed as well as their effect on multidrug-resistant organisms. Summary The present review will focus on the rationale for inhaled therapy, the current studies examining the delivery and clinical efficacy of inhaled antibiotics, and the potential role for this mode of delivery actually decreasing antibiotic resistance in the respiratory tract.
Role of Ca2+ in the regulation of hormone receptor exposure during lymphocyte activation.

Abstract Ca2+ is known to be required for mitogen-mediated lymphocyte activation. In order to further define the regulatory role of Ca2+, we have examined the activation events which occur following treatment with ionomycin (a Ca2+ ionophore), as compared to those occurring following concanavalin A (Con A) treatment of mouse splenic T-lymphocytes. Our results indicate that ionomycin and Con A induce the exposure of both interleukin-2 (IL-2) and insulin receptors on the surface of the lymphocytes within the first 5 min of treatment. The exposed insulin and IL-2 receptors have the following properties: (1) they consists of both high- and low-affinity receptors; and (2) they appear on the cell surface in small clusters (i.e., patches) or, occasionally, a large aggregate (i.e., cap). c-myc gene expression and DNA synthesis occur in both the ionomycin and Con A-treated lymphocytes when either IL-2 or insulin is present in the culture medium. Furthermore, the exposure of both hormone receptors can be inhibited by either EGTA (a Ca2+ chelator), bepridil (a Ca2+ channel blocker), W-7 (a calmodulin antagonist) or cytochalasin D (a microfilament inhibitor). Treatment with these inhibitors also blocks the expression of c-myc gene and DNA synthesis which occur at later times during IL-2 and insulin-induced activation of ionomycin- and Con A-treated lymphocytes. These findings suggest that a Ca2+ and calmodulin-mediated contractile system is involved in the exposure of certain hormone receptors which appear to be required for complete lymphocyte activation.
Crude Protein, Minerals, and Total Carotenoids in Sweet Potatoes

Crude protein and mineral content in six sweet potato cultivars and total carotenoids in four orange-flesh cultivars after different storage treatments were determined. On a fresh weight basis, crude protein between cultivars ranged from 1.36-2.13 g/100g, phosphorus from 38-64 mg/100g, potassium from 245-403 mg/100g, calcium from 20-41 mg/100g, magnesium from 13-22 mg/100g and total carotenoids from 5-11.5 mg/100g. Carotenoids slightly increased after curing and short term storage at either 7o, 15.6o, or 26.6oC. Centennial contained the most protein, phosphorus, magnesium, and carotenoids of all cultivars. Travis contained the lowest amount of protein, phosphorus and potassium, but more carotenoids than Jewel or Jasper.
Forming effective worker teams with multi-functional skill requirements

Throughout much of the past century, manufacturing efficiencies were gained by constructing systems from independently designed and optimized tasks. Recent theories and practice have extolled the virtues of team-based practices that rely on human flexibility and empowerment to improve integrated system performance. The formation of teams requires consideration of innate tendencies and interpersonal skills as well as technical skills. In this project we develop and test mathematical models for formation of effective human teams. Team membership is selected to ensure sufficient breadth and depth of technical skills. In addition, measures of worker conative tendencies are used along with empirical results on desirable team mix to form maximally effective teams. A mathematical programming formulation for the team selection problem is presented. A heuristic solution is proposed and evaluated.
Differential contribution of GTPase activation and effector antagonism to the inhibitory effect of RGS proteins on Gq-mediated signaling in vivo.

RGS proteins act as negative regulators of G protein signaling by serving as GTPase-activating proteins (GAP) for α subunits of heterotrimeric G proteins (Gα), thereby accelerating G protein inactivation. RGS proteins can also block Gα-mediated signal production by competing with downstream effectors for Gα binding. Little is known about the relative contribution of GAP and effector antagonism to the inhibitory effect of RGS proteins on G protein-mediated signaling. By comparing the inhibitory effect of RGS2, RGS3, RGS5, and RGS16 on Gαq-mediated phospholipase Cβ (PLCβ) activation under conditions where GTPase activation is possible versus nonexistent, we demonstrate that members of the R4 RGS subfamily differ significantly in their dependence on GTPase acceleration. COS-7 cells were transiently transfected with either muscarinic M3 receptors, which couple to endogenous Gq protein and mediate a stimulatory effect of carbachol on PLCβ, or constitutively active Gαq*, which is inert to GTP hydrolysis and activates PLCβ independent of receptor activation. In M3-expressing cells, all of the RGS proteins significantly blunted the efficacy and potency of carbachol. In contrast, Gαq* -induced PLCβ activation was inhibited by RGS2 and RGS3 but not RGS5 and RGS16. The observed differential effects were not due to changes in M3, Gαq/Gαq*, PLCβ, or RGS expression, as shown by receptor binding assays and Western blots. We conclude that closely related R4 RGS family members differ in their mechanism of action. RGS5 and RGS16 appear to depend on G protein inactivation, whereas GAP-independent mechanisms (such as effector antagonism) are sufficient to mediate the inhibitory effect of RGS2 and RGS3.
The bicuspid aortic valve aortopathy mystery continues: Are we that mediocre?

Although the bicuspid aortic valve (BAV) was described over 500 years ago by Leonardo da Vinci [1], its association with clinical aortopathy was not recognized until 1928 when Canadian physician Maude Abbott [2] reported on 200 patients with untreated aortic coarctation. In that seminal work, Dr. Maude Abbott [2] found that BAV was associated with aortopathy in 2 ways: as a risk for infective endocarditis in these patients and as a common congenital feature in patients with coarctation and ascending aorta rupture, which led her to argue “for a congenital weakness of the [aortic]wall just above the cusps, as the probable cause of rupture”. Indeed, contemporary studies demonstrate that coarctation of the aorta is more frequent in BAV patients with aortic dissection than in BAV patients without it [3,4]. Similarly, aortic dissection risk is significantly increased in syndromic conditions associated with BAV, including Turner and Loeys– Dietz syndromes [5,6]. Thus, it would seem reasonable to view BAV disease as “complex” with high aortic risk when it is associated with the aforementioned conditions. However, the more common BAV disease is the one diagnosed in adults consisting of a valvulo-aortopathy, with aortic valve dysfunction and dilatation of the aorta as main features. This “simple” form of BAV disease carries a lower risk of dissection estimated from 0.03% to 0.1% per patient-year [7,8]. This low dissection risk is nonetheless at least 8 times that of the
Fracture Behavior of Prestressed Composites Subjected to Shock Loading: A DIC-Based Study

The dynamic fracture behavior of a prestressed orthogonally woven glass fiber-reinforced composite material was experimentally investigated. A shock tube apparatus was used in conjunction with a tensile pre-loading device to apply nominally Mode-I dynamic loading to pre-tensioned, single edge notched specimens. The specimen response was observed with a stereo high speed camera arrangement, and the full-field displacement and strain distributions near the crack tip were extracted using the 3D digital image correlation technique. Critical stress intensity factors for each specimen were determined from the displacement and strain fields using an over-deterministic approach. The magnitude of the pre-load applied to the specimens was shown to influence the crack tip velocity as well as the dynamic stress intensity factor up to the onset of crack propagation. The effect of fiber orientation on both crack tip velocity and dynamic stress intensity factor was also observed.
Reducing the Threat of Rater Nonparticipation in 360-Degree Feedback Systems An Exploratory Examination of Antecedents to Participation in Upward Ratings

An advantage of 360-degree feedback systems is the removal of idiosyncratic single-source bias inherent in traditional top-down performance appraisal systems. Three-hundred-and-sixty-degree feedbac...
Coulomb blockade oscillations of conductance in the regime of strong tunneling.

We study the transport through a quantum dot coupled to two leads by single-mode point contacts. The linear conductance is calculated analytically as a function of gate voltage and temperature $T$ in the case when transmission coefficients of the contacts are close to unity. As a function of the gate voltage, the conductance shows Coulomb blockade oscillations. At low temperatures, the off-resonance conductance vanishes as ${T}^{2}$, in agreement with the theory of inelastic cotunneling. Near a resonance, the low-energy physics is governed by a multichannel Kondo fixed point.
Real life soilers: Holding on and giving up encopresis

Negative public attitudes towards faecal soiling in an English town were revealed as a by-product of a proposed research study. But they are also evident in the language of everyday life. Such entrenched beliefs will also affect soilers and their families. Although encopresis is a medical-sounding word which might form a part of a classificatory system, it is probably just another genteel euphemism for a state of affairs, the mechanics and dynamics of which are so diverse that classification is meaningless. Real life stories show this. Changing behaviours is probably best done by behavioural methods.
Feeding a Premature Infant with Hydranencephaly - Does Development Have a Role in Decision Making? 152

Feeding a Premature Infant with Hydranencephaly - Does Development Have a Role in Decision Making? 152
Children exposed to war in Afghanistan

(2005). Children exposed to war in Afghanistan. Bereavement Care: Vol. 24, No. 2, pp. 31-34.
Pathophysiologic basis for normouricosuric uric acid nephrolithiasis

Pathophysiologic basis for normouricosuric uric acid nephrolithiasis. Background: Low urinary pH is the commonest and by far the most important factor in uric acid nephrolithiasis but the reason(s) for this defect is (are) unknown. Patients with uric acid nephrolithaisis have normal acid-base parameters according conventional clinical tests. Methods: We studied steady-state plasma and urinary parameters of acid-base balance in subjects with normouricosuric pure uric acid stones. We also tested the ability of these subjects to excrete ammonium in response to an acute acid load. We compared these parameters in patients with pure uric acid stones to patients with mixed uric acid/calcium oxalate stones, pure calcium stones, and normal volunteers. Results: Pure uric acid stone formers have a much higher incidence of either diabetes or glucose intolerance. After equilibration to a control diet, patients with uric acid stones have lower urinary pH and they excrete less of their acid as ammonium. This is compensated by higher titratable acidity and hypocitraturia. Despite their low baseline urinary pH, uric acid stone formers further acidify their urine after an acid load because of a severely impaired ammonia excretory response. Their characteristics are significantly different from normal volunteers and pure calcium stone formers. Patients with mixed uric acid/calcium stones exhibit intermediate characteristics. Conclusion: We propose that certain patients with normouricosuric uric acid nephrolithiasis have a renal acidification disease. The primary defect lies in renal ammonium excretion, which may be linked to the insulin-resistant state. Although net acid excretion is maintained at the expense of increased titratable acidity and to some degree hypocitraturia, the compromise is acid urine pH and may result in uric acid nephrolithiasis.
Adsorption of Salivary Proteins by Hydroxyapatite: Effects of Phosphate Ions and Interdependence of the Effects of Phosphate and Hydrogen Ions:

Phosphate ions at physiological concentrations in saliva inhibited adsorption of salivary proteins by hydroxyapatite. Adsorption was related inversely to the concentration of phosphate. Removal of phosphate from saliva abolished or decidedly lowered the stimulating effect of hydrogen ions on adsorption of salivary proteins. Lowering the pH decreased, abolished, or reversed the adsorption inhibitory effect of phosphate.
MODIS Solar Reflective Calibration Traceability

Long-term climate data records often consist of observations made by multiple sensors. It is, therefore, extremely important to have instrument overlap, to be able to track instrument stability, to quantify, measurement uncertainties, and to establish absolute scale traceable to the International System of Units (SI). The Moderate Resolution Imaging Spectroradiometer (MODIS) is a key instrument for both the Terra and Aqua missions, which were launched in December 1999 and May 2002, respectively. It has 20 reflective solar bands (RSB) with wavelengths from 0.41 to 2.2 micrometers and observes the Earth at three nadir spatial resolutions: 0.25km, 0.5km, and 1km. MODIS RSB on-orbit calibration is reflectance based with reference to the bidirectional reflectance factor (BRF) of its on-board solar diffuser (SD). The SD BRF characterization was made pre-launch by the instrument vendor using reference samples traceable directly to the National Institute of Standards and Technology (NIST). On-orbit SD reflectance degradation is tracked by an on-board solar diffuser monitor (SDSM). This paper provides details of this calibration chain, from prelaunch to on-orbit operation, and associated uncertainty assessments. Using MODIS as an example, this paper also discusses challenges and key design requirements for future missions developed for accurate climate studies.
An Autocorrelation Term Method for Curve Fitting

The least-squares method is the most popular method for fitting a polynomial curve to data. It is based on minimizing the total squared error between a polynomial model and the data. In this paper we develop a different approach that exploits the autocorrelation function. In particular, we use the nonzero lag autocorrelation terms to produce a system of quadratic equations that can be solved together with a linear equation derived from summing the data. There is a maximum of solutions when the polynomial is of degree . For the linear case, there are generally two solutions. Each solution is consistent with a total error of zero. Either visual examination or measurement of the total squared error is required to determine which solution fits the data. A comparison between the comparable autocorrelation term solution and linear least squares shows negligible difference.
A novel MINLP-based representation of the original complex model for predicting gasoline emissions

Abstract The Environmental Protection Agency (EPA) introduced Reformulated Gasoline (RFG) requirements as a measure to reduce emissions from gasoline-powered vehicles in certain geographic areas. As part of this effort, the EPA developed empirical models for predicting emissions as a function of gasoline properties and established statutory baseline emissions from a representative set of gasolines. All reformulated gasoline requires certification via this model, known as the Complex Model, and all refiners and importers calculate emissions performance reductions from the statutory baseline gasoline. The current representation of the Complex Model is extremely difficult to implement within refinery operations models or to use in combination with models for designer gasoline. RFG and boutique fuels are key driving forces in the North American refining industry. The RFG models introduce increasingly complex constraints with the major limitation that they are implicitly defined through a series of complicated disjunctions assembled by the EPA in the form of spreadsheets. This implicit and cumbersome representation of the emissions predictive models renders rigorous optimization and sensitivity analysis very difficult to address directly. In this paper, we discuss how the federal government requirements for reformulated gasoline can be restated as a set of mixed-integer nonlinear programming (MINLP) constraints with the aid of disjunctive programming techniques. We illustrate the use of this model with two simple example fuel blending problems.
Potent anti-HIV activity of scytovirin domain 1 peptide.

Abstract Scytovirin (SVN) is a novel anti-HIV protein isolated from aqueous extracts of the cultured cyanobacterium Scytonema varium. SVN contains two apparent domains, one comprising amino acids 1–48 and the second stretching from amino acids 49 to 95. These two domains display significant homology to each other and a similar pattern of disulfide bonds. Two DNA constructs encoding scytovirin 1–48 (Cys7Ser) (SD1) and 49–95 (Cys55Ser) (SD2) were constructed, and expressed in E. coli, with thioredoxin fused to their N-terminus. Purified recombinant products were tested for binding activities with the HIV surface envelope glycoproteins gp120 and gp41. Whole cell anti-HIV data showed that SD1 had similar anti-HIV activity to the full-length SVN, whereas SD2 had significantly less anti-HIV activity. Further deletion mutants of the SD1 domain (SVN(3–45)Cys7Ser, SVN(6–45)Cys7Ser, SVN(11–45)Cys7Ser) showed that the N-terminal residues are necessary for full anti-HIV activity of SD1 and that an eight amino acid deletion from the C-terminus (SVN(1–40)Cys7Ser) had a significant effect, decreasing the anti-HIV activity of SD1 by approximately five-fold.
Report on a new technological community: The making of a technopolis in an international context

Abstract In 1980 the Japanese government conceptualized technopolises. Nine technopolises are already in operation in 1984, and several more will follow. A technopolis is a healthy living environment with cultural amenities combined with high technology industries, away from the existing overcrowded industrial centers and adapted to local characteristics. This article focuses on the most advanced technopolis on the “Silicon Island” Kyushu, describes its process of development, and its future advantages and disadvantages compared to other technopolises.
''How To Do Things with Words'': Role of Motor Cortex in Semantic Representation of Action Words.

Language, believed to have originated from actions, not only functions as a medium to access other minds, but it also helps us commit actions and enriches our social life. This fMRI study investigated the semantic and neural representations of actions and mental states. We focused mainly on language semantics (comprehending sentences with action words versus those with mental state words). While in an fMRI scanner, twenty-four healthy, right-handed adult volunteers read a series of sentences with a verb depicting either a mental state (e.g., deceive, persuade) or an action (e.g., punch, kick), and answered a comprehension question that followed. Overall, this task showed brain activation in the left inferior frontal gyrus and in the left posterior superior temporal sulci. While comprehending sentences with mental state terms, participants showed greater activation in left orbitofrontal, and in left precuneus areas. On the other hand, the action sentences recruited more primary motor, left inferior parietal, bilateral occipital, right superior temporal, and right inferior frontal areas. The findings of this study underscore the role of motor and visuospatial involvement in action word representation in the human brain.
Uptake of 14C-ascorbic acid by the adrenal and pituitary glands and effect of ACTH or dexamethasone administration.

Abstract The distribution of intravenously administered 14C-ascorbic acid (14C-AA) among various tissues of the rabbit and the dog and the effects of dexamethasone or ACTH administration on the distribution were studied. Two hours after the i.v. dose the concentration of 14C-AA was higher in the adrenal than in any other tissue examined. As a function of time, the difference of 14C-AA concentration between adrenal and surrounding organs became greater and 24 hr after the dose the adrenal: liver ratio became 5:1 in dogs. The concentration of 14C-AA in the pituitary gland gradually increased, reaching a peak at 24 hr and exceeding the adrenal concentration at 48 hr and thereafter. After suppression by dexamethasone the concentration of 14C-AA in the adrenal gland was significantly lower than the control value, although the hormone had no detectable effect on the concentration in other tissues. Injection of ACTH for three days before administration of the 14C-AA produced no significant effect on the accumulation of 14C-AA in the adrenal. A single dose of ACTH given 1 hr prior to the 14C-AA, however, significantly increased the accumulation in the adrenal. These results suggest that accumulation of AA in the adrenal occurs through mechanisms that are more complex than those proposed in the literature. The results also suggest that AA may be an effective pituitary scanning agent if it can be labeled with a suitable radionuclide.
Electrical charge measurements on ejecta from impact loading of explosive crystals

Measurements of the properties of the small, macroscopic particles (ejecta) that are released from the impact loading of single crystals of pentaerythritol tetranitrate are presented. Total mass of the ejecta, total electrical charge on the ejecta, and approximate size distributions are also given. A few measurements were also performed on crystals of cyclotrimethylenetrinitramine and cyclotetramethylene tetranitramine.
Why are there so many species in the tropics

Known for centuries, the geographical pattern of increasing biodiversity from the poles to the equator is one of the most pervasive features of life on Earth. A longstanding goal of biogeographers has been to understand the primary factors that generate and maintain high diversity in the tropics. Many ‘historical’ and ‘ecological’ hypotheses have been proposed and debated, but there is still little consensus. Recent discussions have centred around two main phenomena: phylogenetic niche conservatism and ecological productivity. These two factors play important roles, but accumulating theoretical and empirical studies suggest that the single most important factor is kinetics: the temperature dependence of ecological and evolutionary rates. The relatively high temperatures in the tropics generate and maintain high diversity because ‘the Red Queen runs faster when she is hot’.
Leaf phosphate status and photosynthesis in vivo: Changes in light scattering and chlorophyll fluorescence during photosynthetic induction in sugar beet leaves

Abstract Light scattering and chlorophyll fluorescence were measured in vivo for leaves of sugar beet plants cultured with low levels of phosphate (P). Light scattering during photosynthetic induction was markedly increased in low-P compared to control leaves. This effect was reversible, disappearing within 24 h after the P supply was increased. The fluorescence induction curves also exhibited significant and reversible differences between low-P and control leaves. The changes in light scattering and chlorophyll fluorescence correlated well with changes in the rate of photosynthesis in vivo. We suggest that the increase in light scattering during induction in low-P plants may be due to a decreased ability of the Calvin cycle to utilize assimilatory power generated photochemically.
Computed Tomography Screening for Lung Cancer

Importance Low-dose computed tomography (CT) screening was shown to reduce lung cancer–specific mortality in a large randomized trial of a high-risk population. The decision to pursue CT screening for lung cancer is a timely question raised by individuals at risk of lung cancer and by their health care practitioners. Objectives To discuss the evidence for use of chest x-rays and low-dose CT in screening for lung cancer; to describe potential benefits, harms, and uncertainties of CT screening; and to review current guidelines for CT screening. Evidence Review MEDLINE and the Cochrane Library were searched from 1984 to 2012. Additional citations were obtained from lists of references from select research and review articles on this topic. Evidence was graded using the American Hospital Association level of evidence guidelines. Findings Low-dose CT screening has been associated with a 20% reduction in lung cancer mortality in a large randomized controlled trial (National Lung Screening Trial [NLST]) of a high-risk population. Mortality data have not yet been reported for 5 other randomized controlled trials, and the sample sizes were too small to detect a meaningful difference in 2 other completed trials. A major risk of CT screening is a high false-positive rate, with associated risks and costs associated with follow-up CT scans and the potential for more invasive diagnostic procedures. Published guidelines for screening indicate a consensus that screening may be indicated for individuals who meet entry criteria for the NLST, but some guidelines expand their recommendations for screening beyond these criteria. Conclusions and Relevance Individuals at high risk of lung cancer who meet the criteria for CT screening in published guidelines should participate in an informed and shared decision-making process by discussing the potential benefits, harms, and uncertainties of screening with their physicians.
Modeling energy transport through the hot-electron microcalorimeter

Abstract We present numerical simulations of the diffusion of energy through the hot-electron microcalorimeter. This detector uses a normal-insulator-superconductor tunnel junction to measure the energy deposited by X-ray photons in the normal electrode. The photon energy is converted into heat stored by electrons and is detected as a change in the current flowing through the junction. We show that a measurement of only the pulse height can cause errors in the deduced photon energy, and that a numerical correction based on either the fall or rise time of the pulses can be used to deduce both the original photon energy and the location of the absorbed photon.
Tunicamycin--an inhibitor of yeast glycoprotein synthesis.

Tunicamycin, a glucosamine-containing antibiotic, halted synthesis of the external glycoproteins invertase, acid phosphatase and mannan by yeast protoplasts within 30 min; formation of two intracellular proteins, alpha-glucosidase and alkaline phosphatase, and of glucan continued at the control rate for at least 60–80 min. No accumulation of mannan-free acid phosphatase or invertase was evident in treated cells. Utilization of hexoses and incorporation of 14C-amino acids into protein were not affected. Incorporation of 3H-glucosamine into trichloroacetic acid-insoluble products was only partially reduced. In yeast tunicamycin acts primarily as an inhibitor of glycoprotein synthesis and not of general glucosamine metabolism.
The Experience and Expression of Stepchildren's Emotions at Critical Events in Stepfamily Life

This study explored the experience and expression of emotions of adult stepchildren during four critical events in stepfamily life. During semistructured, in-depth interviews, 57 adult stepchildren shared stories about four critical events: the parental divorce, remarriage of one of the parents, an event in the stepfamily that generated feeling more like a family, and an event in the stepfamily that generated feeling less like a family. A total of 402 pages of single-spaced transcripts were coded for emotion, target, and expression of emotion resulting in positive and negative emotion categories and subcategories for all four critical events. Five research questions centered on the emotions commonly experienced during the four aforementioned critical events, the targets of disclosure, and the patterns that indicate a tendency to manage emotion expression.
High sensitivity detection of naturally occurring radiocarbon—I Chemistry of the counting sample

Abstract The production of C14 on the earth by cosmic rays has received wide attention as a means of determining the ages of archeological and geological samples. However, the low activities that must be measured necessitate devising special sensitive counting arrangements. This is particularly true if it is desired to extend the usefulness of the technique to materials several tens of thousands of years old or at the other end of the time scale, for samples only a few hundred years old. The most promising method of increasing the sensitivity of radiocarbon dating is the use of radiation detection techniques that are capable of counting large quantities of carbon. The liquid scintillation spectrometer is an instrument that has been applied in several cases to increase the efficiency of C14 dating. This paper presents a means by which the entire counting solution (not including the small amounts of phosphors) can be synthesized from the sample to be dated. The solvent used is benzene, which is one of the most suitable materials for liquid scintillation counting since it contains 92 per cent carbon and shows no scintillation quenching properties. The chemistry involved in the complete synthesis of benzene is described in detail. The sample to be dated is burned and carbon dioxide collected in ammonium hydroxide solution. Strontium carbonate is precipitated upon the addition of strontium chloride. The dried carbonate is mixed with magnesium powder and strontium carbide is produced by ignition of the mixture in an evacuated stainless steel tube. Reaction of the carbide with water generates acetylene which is led into a circuit containing dry ice-cooled traps and a pyrolysis tube at 600°C. The acetylene polymerizes to benzene. This is collected in the cooled traps and then purified by distillation. The overall yield in the synthesis is 30 per cent. The chemical steps involve no special equipment or training. A 20-ml sample can be produced by two man-days of work and the entire procedure completed in less than a week.
Incomplete and inevitable abortion: Treatment by suction curettage in the emergency department

Suction curettage for inevitable and incomplete spontaneous abortion has been performed by emergency physicians in the emergency department of the Central Group Health Hospital in Seattle for more than seven years. The equipment and techniques used in our practice are described, and guidelines for treatment are presented. Also presented is an analysis of 111 consecutive patients treated with suction curettage during an 18-month period with a minimum follow up of six months. The complication rate was minimal (4.5%), and compares favorably with previously published results of inpatient treatment. Several significant advantages of treating incomplete and inevitable abortion with suction curettage in the emergency department are described.
The "dis-location" of U.S. medicine--the implications of medical outsourcing.

When a patient in Altoona, Pa., needs an emergency brain scan in the middle of the night, a doctor in Bangalore, India, is asked to interpret the results. Spurred by a shortage of U.S. radiologists and an exploding demand for more sophisticated scans to diagnose scores of ailments, doctors at Altoona Hospital and dozens of other American hospitals are finding that offshore outsourcing works even in medicine. . . . Most of the doctors are U.S.-trained and licensed — although there is at least one experiment using radiologists without U.S. training. —Associated Press, December 6, 2004 Until recently, the need . . .
Genetic variation within maize population GT-MAS:gk and the relationship with resistance to Aspergillus flavus and aflatoxin production

Aspergillus flavus (Link:Fr.) infection and aflatoxin contamination of maize (Zea mays L.) grain are an extremely serious problem. Maize genotypes resistant to A. flavus attack are needed. Maize breeders and plant pathologists must identify resistance sources and incorporate resistance into adapted breeding material. Maize population GT-MAS:gk has been released for use as a resistance source. In this study, we surveyed the genetic variation in this population and made the breeders/plant pathologists aware of the heterogeneous nature in this maize population by using RAPD analysis and correlated the RAPD marker association with the resistance to A. flavus and aflatoxin production. Of 40 RAPD primers, only 15 gave sufficient numbers of reproducible and readily scored polymorphic bands suggesting that this population was highly homogeneous. However, genetic distances, ranging from 0.08 to 0.28 and averaging 0.17, suggest that there is variation within the population. Cluster analysis distinguished three major polymorphic groups. Laboratory bioassay revealed that group I contained the most resistant individuals, i.e., those with less aflatoxin production. Group II had the least resistance, and group III was intermediate. This study showed that the maize population GT-MAS:gk is heterogeneous and individuals are different in resistance to A. flavus and aflatoxin production. Resistance should be confirmed through progeny testing before further development. The RAPD marker OPX-04, which may be associated with the resistance trait, has been cloned and further characterization will be pursued.
Man‐made earthquakes and earthquake prediction

Convincing evidence that man can trigger earthquakes has been developed since the 1963–1967 report. The fact that man can start earthquakes has increased our understanding of earthquake mechanisms and reinforced our judgment that we are approaching the possibility of earthquake prediction. Traditionally, seismologists have avoided the subject of earthquake prediction because of its distasteful association with people who claim to be able to predict earthquakes by mystical nonscientific methods. Research on prediction has been intensified since the reports of the Panel on Earthquake Prediction [Press, 1965] and the Interagency Working Group for Earthquake Research [Pecora, 1968],. however, and it is appropriate to assess our progress toward that goal. Pakiser et al. [1969] and Oliver [1970] have also summarized recent U.S. progress toward earthquake prediction.
Scotus on the Consistency of the Incarnation and the Trinity

Etude de l'effort de demonstration de la consistance des doctrines theologiques de l'Incarnation et de la Trinite entrepris par Duns Scot a partir de la logique des propositions redoublantes ou qua introduites par la formule dans la mesure ou. Soulevant le paradoxe de l'unite et de la trinite de Dieu, de la creation et de la non creation de Jesus-Christ, de la separation du Pere et du Fils, l'A. montre que l'analyse specificative et abstractive de Duns Scot offre une solution plus plausible du point de vue de la scientificite aristotelicenne que celle proposee par Saint Thomas d'Aquin
Midcourse Space Experiment Spectra of the Orion Nebula and the Implications for Abundances in the Interstellar Medium

Spectra of the Orion Nebula were obtained with the Midcourse Space Experiment Spirit 3 interferometer from 370 to 2000 cm(exp -1) with 2 cm(exp -1) resolution in a 6' x 9' field of view (FOV) in 1996 November. Lines were detected of [S III] 534.4 cm(exp -1), [Ne III] 642.9 cm(exp -1), [Ne II] 780.4 cm(exp -1), [S IV] 951.4 cm(exp -1), [Ar III] 1112.2 cm(exp -1), [Ar II] 1431.6 cm(exp -1), H (7-6) 808.3 cm(exp -1), H (8-6) 1332.9 cm(exp -1), H (6-5) 1340.5 cm(exp -1), H2(S1) 587.0 cm(exp -1), H2(S2) 814.4 cm(exp -1), H2(S3) 1034.7 cm(exp -1), H2(S4) 1246.1 cm(exp -1), and H2(S5) 1447.3 cm(exp -1). The following abundances were determined from these lines: Ne/H = 9.9 +/- 1.1 x 10(exp -5), S/H = 8.1 +/- 1.1 x 10(exp -6), and Ar/H = 2.5 +/- 0.2 x 10(exp -6). These abundances are all less than solar and confirm that the Sun is overabundant in heavy elements without the need for correction for the composition of interstellar dust. The low sulfur abundance compared with solar is an indication that a significant amount of the sulfur in Orion is in dust grains. The FOV-averaged molecular hydrogen column density is approximately 1.6 x 10(exp 20) cm(exp -2) for an excitation temperature of approximately 670 K and an extinction correction corresponding to an optical depth of 1.5 at 9.7 micrometers. The unidentified infrared emission features at 6.2, 7.7, 8.6, 11.3, and 12.7 micrometers, attributable to polycyclic aromatic hydrocarbons, were also detected. A prominent, broad silicate feature centered near 18 micrometer and additional weak features were detected and are discussed.
A two-way enriched clinical trial design: combining advantages of placebo lead-in and randomized withdrawal

A new clinical trial design, designated the two-way enriched design (TED), is introduced, which augments the standard randomized placebo-controlled trial with second-stage enrichment designs in placebo non-responders and drug responders. The trial is run in two stages. In the first stage, patients are randomized between drug and placebo. In the second stage, placebo non-responders are re-randomized between drug and placebo and drug responders are re-randomized between drug and placebo. All first-stage data, and second-stage data from first-stage placebo non-responders and first-stage drug responders, are utilized in the efficacy analysis. The authors developed one, two and three degrees of freedom score tests for treatment effect in the TED and give formulae for asymptotic power and for sample size computations. The authors compute the optimal allocation ratio between drug and placebo in the first stage for the TED and compare the operating characteristics of the design to the standard parallel clinical trial, placebo lead-in and randomized withdrawal designs. Two motivating examples from different disease areas are presented to illustrate the possible design considerations.
Transneuronal effects on amphibian limb regeneration.

This investigation has demonstrated that in both the newt and axolotl the simultaneous removal of a second limb brings about a significantly slower linear regeneration rate, but only if the second limb removed is directly contralateral to the first one removed. Both morphologic and autoradiographic data point to a more prolonged chromatolysis in the brachial neurons following contralateral forelimb removal. This is thought to bring about the slower regeneration rate seen. Further evidence for this contention is the fact that just the severance of the brachial nerves of one forelimb of an animal will bring about a significantly slower regeneration rate of the contralateral forelimb. In salamanders without intervening nervous connections or CNS tissue between the limbs, i. e., the aneurogenic larvae, no effect on regeneration rate is seen following contralateral double limb removal. Autoradiographs using 3H thymidine as a precursor point to an early effect on growth as being the means that contralateral denervation or limb removal brings about a slower regeneration rate. This is thought to be due to a decrease in the trophic ability of the brachial innervation following the more profound disruption of the brachial neurons that accompanies double limb removal.