cssi/SciSciGPT-SciSciNet huggingface dataset:
Inelastic Collisions with Changes of Mass and the Problem of Nuclear Disintegration with Capture or Non-Capture of a Neutron or Another Nuclear Projectile

Relativity equations are developed for the relations involved in the disintegration of an atomic nucleus by bombardment with a nuclear projectile which is not captured in the process. Similar equations for velocities not too close to that of light are also developed; these are based on the rest-masses and the only relativity term is that involved in the change of mass produced by the collision (${E}_{m}={c}^{2}\ensuremath{\Delta}m$). The relativity equation for the velocity of the projectile is: ${V}_{A}=\frac{{({k}_{C}{m}_{C}{v}_{C}+{k}_{D}{m}_{D}{v}_{D})}^{2}\ensuremath{-}{c}^{2}{({k}_{C}{m}_{C}+{k}_{D}{m}_{D}\ensuremath{-}{m}_{B})}^{2}+2{c}^{2}{k}_{A}{m}_{A}({k}_{C}{m}_{C}+{k}_{D}{m}_{D}\ensuremath{-}{m}_{B})}{2{k}_{A}{m}_{A}({k}_{C}{m}_{C}{v}_{C}+{k}_{D}{m}_{D}{v}_{D})cos\ensuremath{\alpha}}$ while the similar equation for not too high velocities is: ${V}_{A}=\frac{{{M}^{2}+2{m}_{A}[{E}_{C}+{E}_{D}+{c}^{2}({m}_{C}+{m}_{D}\ensuremath{-}{m}_{B})]}}{2{m}_{A}Mcos\ensuremath{\alpha}}$ in which $M$ represents momentum, $E$ is kinetic energy, $m$ mass, $v$ velocity, $c$ the velocity of light, and $A$, $B$, $C$ and $D$ are the nuclei involved. If a $\ensuremath{\gamma}$-ray is emitted the expression between brackets in Eq. (16) contains in addition a term $E\ensuremath{\gamma}$. A careful analysis is made of the evidence which has formerly seemed to indicate that in the majority of disintegrations produced by neutrons the neutron is captured. The conclusion is reached that this evidence is valid. A similar analysis of the evidence for non-capture of the neutron indicates that this evidence is not valid. Thus the velocities given for the neutron as calculated by either Eq. (5\ensuremath{'}) or Eq. (16) are in general higher, when the nitrogen nucleus is disintegrated, than that of any known neutron. It is found that the curve which gives the relation between the number of disintegrations and the velocities of the neutrons which produce them, is practically the same for scattered as for non-scattered neutrons, provided both are assumed to disintegrate by capture. There seems to be no evidence which indicates that any nucleus has been disintegrated by bombardment of another nucleus without capture. Obviously this does not prove that non-capture disintegrations are non-existent.
Spinodal decomposition in a Hele-Shaw cell

As an experimentally realizable two-dimensional fluid system, we perform a cell-dynamical system simulation of a binary incompressible fluid that undergoes spinodal decomposition after a critical quench in a Hele-Shaw cell. Fluidity enhances fluctuations of interfaces, resulting in a form factor that continuously depends on the fluidity of the system. In this system, finite size coupled with the effect of incompressible flow is found to have a severe accelerating effect on the growth law.
Type 2 diabetic obese db/db mice are refractory to myocardial ischaemic post-conditioning in vivo: potential role for Hsp20, F1-ATPase δ and Echs1.

Ischaemic post-conditioning (PostC) is a clinically relevant cardioprotective modality that has been confirmed in many species including human. It remains unknown if PostC can still protect heart in Type 2 diabetes, a rapidly growing disease in the world. This study investigated the efficacy of PostC in the leptin receptor–deficient db/db mice, which possess Type 2 diabetic characteristics including obesity, hyperglycaemia and hyperleptinaemia. Adult male C57BL/6J wild-type (WT) and db/db mice were anaesthetized, mechanically ventilated and subjected to left coronary artery occlusion for 30 min. followed by 24 hrs of reperfusion. For the PostC groups, the hearts underwent six cycles of 10 sec. of reperfusion and 10 sec. of re-occlusion at the onset of reperfusion. The mice were sacrificed at the end of 24 hrs reperfusion for infarct size measurement. PostC significantly reduced infarct size in WT mice (n = 6/group; P < 0.05), but not in the db/db mice. To identify alterations in protein expression by PostC, proteomic analyses were performed in the heart samples using two-dimensional differential in-gel electrophoresis with three CyDye labelling, followed by mass spectrometry. The results show that mitochondrial proteins (F1-ATPase γ and Echs1) were down-regulated by PostC in WT heart. Such change was absent in the db/db heart. On the other hand, PostC reduced Hsp20 in the diabetic heart. In summary, PostC fails to protect Type 2 diabetic mice against ischaemia-reperfusion injury. The potential protein targets for the loss of PostC may include F1-ATPase γ, Echs1 and Hsp20 that could regulate cellular ATP consumption/production and defense response to ischaemic stress.
Electron count control of the structures of the 214 superconductors La2−xMxCuO4 (M = Sr, Ba)

Abstract A detailed series of band-structure calculations using the tight-binding method have been performed on the LTO, LTT, and HTT phases of the Sr and Ba substituted La2CuO4 systems. The effects of the subtle geometric changes that occur upon doping on the electronic band structure have been investigated. It is shown that the variable electronic occupation of the highest occupied can be used to understand the complex structural behaviors in these systems.
Analysis of outcomes for single-incision laparoscopic surgery (SILS) right colectomy reveals a minimal learning curve

Background Single-incision right colectomy has emerged as a safe and feasible alternative to standard laparoscopic resection. As with any new surgical approach, definition of the number of procedures required to optimize the technique is an important goal. Data on this learning curve for single-incision right colectomy are lacking; therefore, we report the outcomes of consecutive single-incision right colectomies to identify the procedural learning curve.
Organic Photovoltaic Cells Based on Molecular Donor-Acceptor Heterojunctions

Small molecule based organic photovoltaic cells have attracted considerable interest as a potential solution for low-cost solar energy conversion in the near future. In this review, we first discuss the operation, advantages, and limitations of three different molecular donor-acceptor heterojunction structures. We then discuss the phase separation in molecule donor-acceptor mixtures and its impact on the photovoltaic performance. Methods to achieve bulk heterojunctions with controlled nanoscale geometry are also reviewed. Finally, we provide an outlook on major remaining challenges to the further development of this photovoltaic technology.
Symmetrical refractive error elevates stereo thresholds

We measured the effects of symmetrical spectacle blur on stereo thresholds using anaglyphlc dynamic random element stereograms (ADRES) across a two octave range of hypercyclopean spatial frequencies in three subjects. Symmetrical blur elevated subjects' stereo thresholds. The absolute and relative amount of threshold elevation increased with hypercyclopean spatial frequency.
THE DIMENSIONS OF SPIRITUALITY

The purpose of the study was to identify the major dimensions of spirituality by asking 147 participants to rate 122 adjectives for how spiritual each seemed. Participants were 70% female, 30% male, with an average age of 24 yr. 66% were college undergraduates, and their ethnicities were 44% Euro-American, 20% African American, 14% Asian or Asian American, and 14% Latino. A principal components factor analysis was performed on the responses, and seven interpretable factors emerged. Four represented various dimensions of spirituality. One indicated what is not spiritual. One reflected the positive tone of many of the items. And the last represented adventurousness. The four spiritual factors were named Loving Connection to others, Self-effacing Altruism, Blissful Transcendence, and Religiosity/Sacredness. The one factor that garnered very low ratings for spirituality was named Lonely/Angry and consisted of items related to anger, pointlessness, selfishness, abandonment, and loneliness.
A Faculty–Librarian Partnership: A Unique Opportunity for Course Integration

ABSTRACT Librarians at the University of California, Berkeley have created a partnership with faculty in the teaching of a special course, “Introduction to Environmental Studies.” This class is interdisciplinary in nature, covering science and the humanities, and has offered a unique opportunity for library staff to develop a special program incorporating the teaching of analytical skills along with research skills for specific subject areas. The continuous collaboration with faculty and the challenges of working with students with very varied backgrounds and interests are the main points of discussion in this article.
Interaction between bone morphogenetic protein receptor type 2 and estrogenic compounds in pulmonary arterial hypertension

AbstractThe majority of heritable pulmonary arterial hypertension (HPAH) cases are associated with mutations in bone morphogenetic protein receptor type 2 (BMPR2). BMPR2 mutation carries about a 20% lifetime risk of PAH development, but penetrance is approximately three times higher in females. Previous studies have shown a correlation between estrogen metabolism and penetrance, with increased levels of the estrogen metabolite 16α-hydroxyestrone (16αOHE) and reduced levels of the metabolite 2-methoxyestrogen (2ME) associated with increased risk of disease. The goal of this study was to determine whether 16αOHE increased and 2ME decreased penetrance of disease in Bmpr2 mutant mice and, if so, by what mechanism. We found that 16αOHE∶2ME ratio was high in male human HPAH patients. Bmpr2 mutant male mice receiving chronic 16αOHE had doubled disease penetrance, associated with reduced cardiac output. 2ME did not have a significant protective effect, either alone or in combination with 16αOHE. In control mice b...
Identification of butyrylcholinesterase adducts after inhibition with isomalathion using mass spectrometry: difference in mechanism between (1R)- and (1S)-stereoisomers.

Previous kinetic studies found that butyrylcholinesterase (BChE) inhibited by (1R)-isomalathions readily reactivated, while enzyme inactivated by (1S)-isomers did not. This study tested the hypothesis that (1R)- and (1S)-isomers inhibit BChE by different mechanisms, yielding distinct adducts identifiable by peptide mass mapping with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI–TOF–MS). Equine BChE (EBChE) was inhibited to <10% of control activity with each isomer of isomalathion and the reference compound isoparathion methyl. Control and treated enzyme was digested with trypsin, and peptides were fractionated with HPLC. Separated and unseparated peptides were analyzed with MALDI–TOF–MS. Identity of an organophosphorus peptide adduct was confirmed by fragmentation using postsource decay analysis. EBChE inhibited by (1R)-isomalathions or (S)-isoparathion methyl readily reactivated after oxime treatment with 30–40% activity recovered. Enzyme inactivated by (1S)-isomalathions or (R)-isoparathion methyl recovered <2% and <5% activity, respectively, after oxime treatment. MALDI–TOF–MS analysis revealed that inhibition of EBChE by (1R)-isomalathions and (R)- or (S)-isoparathion methyl yielded O,S-dimethyl phosphate adducts. Enzyme inactivated by (1S)-isomalathions produced only O-methyl phosphate adduct. EBChE modified by (1R)-isomalathions or either enantiomer of isoparathion methyl yielded an O-methyl phosphate adduct as well. The results indicate that EBChE inhibition by (1R)-isomalathions proceeds with loss of diethyl thiosuccinate, but inactivation by (1S)-isomers occurs with loss of thiomethyl as the primary leaving group followed by rapid expulsion of diethyl thiosuccinate to yield an aged enzyme. Furthermore, the data suggest that aging of the O,S-dimethyl phosphate adduct occurs via an SN2 process with loss of thiomethyl.
Otherness and the rhetorical exigences of theistic religion

The emergence of the epoch of transcendence identified by John Angus Campbell can be better understood by a closer look at one of its constituting elements—the development of Hebrew monotheism. The rhetorical character of monotheism is a direct consequence of its symbolic engagement with the wholly Other. Out of this engagement emerges three distinctive rhetorical exigencies—prophecy, gospel, and praise—which call forth rhetorical acts. Rhetorical activity within monotheistic religion is continuous, since successfully addressing one exigence will typically intensify another.
An extrinsic room temperature phosphorescent probe. Remarkable shielding of benzophenone triplet at the active site of chymotrypsin

Benzophenone can be used as an extrinsic triplet state probe, as its phosphorescence, a broad band centered at 445 nm, is readily observable in aqueous solution at room temperature. When bound covalently as an acyl enzyme at the active site of chymotrypsin, the benzophenone probe produces phosphorescence which is unusually resistant to quenching by O2, trans-cinnamic acid, and H3O+. Sodium 2-naphthalenesulfonate quenches the phosphorescence, probably indirectly. The quenching data indicate that the local protein structure at the enzyme active site provides a rigid and protective substrate environment, which is not penetrated by even the smallest triplet quenchers.
Exposure history of shergottites

The cosmogenic nuclides Cl-36, Al-26, Be-10, and Mn-53 were analyzed in Shergotty, ALHA 77005, and EETA 79001 shergottites by means of accelerator mass spectrometry and neutron activation. The cosmogenic radionuclide data were combined with noble gas data and cosmic ray track data to obtain the exposure ages, terrestrial ages, preatmospheric radii, and ablation depths for the three shergottites. The results indicate that none of the three meteorites was irradiated measurably by cosmic rays on its parent body, and that all three objects were ejected from greater than a 3-m depth in their parent bodies. The EETA 79001 meteorite was ejected in an event distinct from that of ALHA 77005 and Shergotty. All three shergottites show a very small amount of ablation, suggesting low velocities on entry into the earth's atmosphere.
Generation of anti-(+)methamphetamine antibodies is not impeded by (+)methamphetamine administration during active immunization of rats.

The goal of these studies was to determine if chronic (+)methamphetamine ((+)METH) administration affects the production of anti-(+)METH antibodies during active immunization of rats. Active immunization for the treatment of chronic drug abuse has been proposed for drugs such as cocaine and nicotine. However, studies have not adequately addressed whether continual drug use during treatment would affect the development of an immune response. For the current studies, male Sprague–Dawley rats were immunized with either keyhole limpet hemocyanin (KLH; control group) or a (+)METH hapten ((+)METH with a six carbon spacer group at the para position of the ring structure)–KLH conjugate. The (+)METH–KLH animals were further divided into two groups. One group was immunized with no subsequent administration of (+)METH, while the other group was immunized and repeatedly challenged (twice a week throughout the study) with an i.p. dose of 3 mg/kg (+)METH. The results showed that the two groups of (+)METH–KLH immunized rats developed and maintained anti-(+)METH antibody titers. The anti-(+)METH immune responses of the two groups were not statistically different (P<0.05) as measured by serum titers and the relative antibody affinities. These data suggest that repeated administration of (+)METH does not affect the generation of an anti-(+)METH antibody response in actively immunized rats.
Rapid Liquid Fuel Mixing for Lean-Burning Combustors: Low-Power Performance

Designers of advanced gas turbine combustors are considering lean direct injection strategies to achieve low NO x emission levels. In the present study, the performance of a multipoint radial airblast fuel injector Lean Burn injector (LBI) is explored for various conditions that target low-power gas turbine engine operation. Reacting tests were conducted in a model can combustor at 4 and 6.6 atm, and at a dome air preheat temperature of 533 K, using Jet-A as the liquid fuel. Emissions measurements were made at equivalence ratios between 0.37 and 0.65. The pressure drop across the airblast injector holes was maintained at 3 and 7-8 percent. The results indicate that the LBI performance for the conditions considered is not sufficiently predicted by existing emissions correlations. In addition, NO x performance is impacted by atomizing air flows, suggesting that droplet size is critical even at the expense of penetration to the wall opposite the injector. The results provide a baseline from which to optimize the performance of the LBI for low-power operation.
Protein adsorption on to low-temperature isotropic carbon 4. Competitive adsorption on carbon and silica studied by two-dimensional electrophoresis

Abstract Two-dimensional polyacrylamide gel electrophoresis (2D PAGE) was applied to the study of competitive protein adsorption from diluted human plasma. We obtained the depletion (adsorption) of some 25 plasma proteins in the presence of low-temperature isotropic carbon (LTIC) or silica powders. The depletion data are used as a measure of protein adsorptivity. Generally, proteins of lowest abundance have the highest tendency to associate with the two solid surfaces studied. The adsorptivity of a protein is largely determined by its solubility. Most proteins detected exhibit similar depletion behavior on both adsorbents, suggesting a multilayer adsorption process. Three proteins, hemopexin, apolipoprotein A I, and apolipoprotein A II, are depleted differently in the presence of LTIC and silica powders.
On the observation of lattice and grain boundary dislocations in UO2 deformed at high temperatures

The microstructure of a series of deformed, polycrystalline uranium dioxide specimens has been studied by transmission electron microscopy. The lattice and grain boundary dislocation structures observed correlate with three temperature regimes of deformation. At temperatures below the brittle to ductile transition temperature, Tc, the specimen is completely brittle and all grains are essentially free of dislocations. The grain boundary structures observed in these brittle specimens are very regular in appearance. In the temperature range between the high temperature transition, Tt, and Tc, where small degrees of plastic deformation are recorded prior to fracture, the first evidence of dislocation activity within the grains is noted, while the boundary structures remain regular. Above Tt, appreciable plasticity occurs prior to fracture and extensive dislocation network formation occurs in the grains of the polycrystal. In addition, the structures in the grain boundaries become very irregular in appearance. A qualitative discussion of the deformation process in polycrystalline UO2 is derived from the observations of this study.
On the mechanism of the thermal F + C2H4 reaction. the molecular elimination of HF from chemically activated C2 H4F radicals

Abstract The moderated nuclear recoil technique has been used to investigate the gas-phase unimolecular reaction behavior of activated C2H418F radicals produced by addition of thermal 18F atoms to C2H4. At low pressures, these radicals decompose both by H-atom loss and by molecular H18F elimination.
Ventricular standstill complicating left heart catheterization in the presence of uncomplicated right bundle branch block

We report the unusual occurrence of complete heart block during attempted right coronary artery cannulation in a patient with pre-existing uncomplicated right bundle branch block (RBBB). This complication occurred due to accidental impingement of the Judkin's right coronary catheter on the left bundle when it transiently slipped across the aortic valve. The block resolved without any complication.
Exercise and well-being: a review of mental and physical health benefits associated with physical activity.

Purpose of reviewThis review highlights recent work evaluating the relationship between exercise, physical activity and physical and mental health. Both cross-sectional and longitudinal studies, as well as randomized clinical trials, are included. Special attention is given to physical conditions, i
Observation of surface-induced broken time-reversal symmetry in YBa 2 Cu 3 O 7 tunnel junctions

Data from $\mathrm{ab}$-oriented ${\mathrm{YBa}}_{2}{\mathrm{Cu}}_{3}{\mathrm{O}}_{7}/\mathrm{I}/\mathrm{Cu}$ tunnel junctions are presented. Self-assembled monolayers form the insulating tunnel barrier, I. The ${\mathrm{YBa}}_{2}{\mathrm{Cu}}_{3}{\mathrm{O}}_{7}$ features in the tunneling conductance match those of low-leakage $\mathrm{ab}$-oriented ${\mathrm{YBa}}_{2}{\mathrm{Cu}}_{3}{\mathrm{O}}_{7}/\mathrm{Pb}$ junctions. Results show that the zero-bias conductance peak is an Andreev bound state (ABS) of a $d$-wave order parameter. In zero magnetic field, the ABS splits below $\ensuremath{\sim}7\mathrm{K}$, consistent with the presence of a subdominant order parameter at the surface. An applied magnetic field induces further splitting that grows nonlinearly with increasing field.
Gas chromatography/mass spectrometry method for the determination of sulforaphane and sulforaphane nitrile in broccoli

Phytochemicals, especially the secondary metabolites synthesized by plants, play key roles in human nutrition, health, wellness, and disease prevention. Some phytochemicals may be harmful to human ...
Fermentation and nutritive value of Zea mays and lucerne forage ensiled with added rolled barley

The effect of adding rolled barley on the ensiling characteristics and nutritive value of lucerne and corn (Zea mays) forage was studied using 19-1 plastic mini-silos. Other factors evaluated with lucerne were the effect of wilting and added lactic acid bacteria. Rolled barley was added at rates of 0, 50, 100 and 150gkg−1 (wet weight) to lucerne or corn forage. Lucerne was ensiled at 170–330 g kg−1 dry matter (DM) and lactic acid bacteria were applied at 105g−1 wet forage. Addition of rolled barley consistently improved the fermentation of lucerne by lowering the pH and decreasing the concentration of acetate and ammonia nitrogen. Wilting of lucerne had variable effects on fermentation in two experiments. The addition of lactic acid bacteria improved fermentation by decreasing the concentrations of acetate and ammonia nitrogen, improved the nutritive value by increasing the in vitro dry matter digestibility (IVDMD), and was associated with decreased amounts of lactic acid. Corn was ensiled at 250 g kg−1 DM, and added rolled barley had little effect on the fermentation of corn silage. The digestibility of all silages determined in vitro was improved by the addition of rolled barley.
Pregnancy in women with pulmonary fibrosis: A case report of pregnancy in a woman with idiopathic pulmonary hemosiderosis

Pregnancy causes a profound amount of respiratory stress on the body of the normal woman. For the woman with a chronic pulmonary disease such as pulmonary fibrosis (PF), pregnancy is not only a source of respiratory stress but can also be a life-threatening condition for both her and the unborn baby. We report an older adolescent with idiopathic pulmonary hemosiderosis (IPH) and PF who became pregnant and delivered a healthy infant. She is the first documented patient with this disease to suffer no exacerbations of her IPH during pregnancy. We also review potential respiratory problems, such as respiratory insufficiency and death, of both the mother and her unborn infant, which can occur in women with PF.
Three-Body Calculations with Local Potentials

A two-term separable approximation to the two-particle $t$ matrix is developed which preserves exact behavior at each bound-state or resonance pole. While introducing no additional singularities, the approximation also produces the exact right-hand cut. This separable approximation is applied to the three-particle scattering problem with local potentials, and numerical results are obtained for the three-body binding energy in the case of the Yukawa and exponential potentials. A prescription is given for increasing the accuracy of this approach by systematically increasing the number of separable terms. This procedure is tested numerically, as is a method for estimating the error in such calculations. Binding-energy results are also presented for a modified pole approximation, and a simple explanation is given for the infinite-binding-energy phenomenon observed by Osborn for separable potentials.
Examining the long-term stability of overgeneral autobiographical memory.

Overgeneral autobiographical memory (OGM) is a proposed trait-marker for vulnerability to depression, but relatively little work has examined its long-term stability. This study investigated the stability of OGM over several years in 271 late adolescents and young adults participating in a larger longitudinal study of risk for emotional disorders. The Autobiographical Memory Test (AMT) was administered twice, with test–retest intervals ranging from approximately 3 to 6 years. There was evidence of significant but modest stability in OGM over several years. Specifically, Spearman rank correlations (ρs) between the proportions of specific and categoric memories generated on the two AMTs were .31 and .32, respectively. We did not find evidence that the stability of OGM was moderated by the length of the test–retest interval. Furthermore, the stability coefficients for OGM for individuals with and without a lifetime history of major depressive disorder (MDD) were relatively similar in magnitude and not signif...
Analysis and composition of oil of lemon by gas-liquid chromatography☆

Abstract Cold-pressed California lemon oil was examined by means of gas-liquid chromatography and a number of the constituents present was tentatively identified by means of corrected retention volume correlation employing two stationary liquid phases. The components identified by these procedures were: α-pinene, β-pinene, myrcene, d -limonene, n -heptanal, 1,8-cineole, ψ-terpinene, n -hexanol, n -octanal, methyl heptenone, n -nonanal, linalool, n -decanal, citronellyl acetate, citronellal, n -undecanal, tetrahydrogeraniol, decyl acetate, geraniol, α-terpineol, citronellol, neral, geranyl acetate, citral, and d -carvone.
Physical initialization using SSM/I rain rates

Following our recent study on physical initialization for tropical prediction using rain rates based on outgoing long-wave radiation, the present study demonstrates a major improvement from the use of microwave radiance based rain rates. A rain rate algorithm is used on the data from a special sensor microwave instrument (SSM/1). The initialization, as before, uses a reverse surface similarity theory, a reverse cumulus parameterization algorithm and a bisection method to minimize the difference between satellite-based and the model-based outgoing long-wave radiation. These are invoked within a preforecast Newtonian relaxation phase of the initialization. These tests are carried out with a high-resolution global spectral model. The impact of the initialization on forecast is tested for a complex triple typhoon scenario over the Western Pacific Ocean during September 1987. A major impact from the inclusion of the SSM/I is demonstrated. Also addressed are the spin-up issues related to the typhoon structure and the improved water budget from the physical initialization. DOI: 10.1034/j.1600-0870.1993.t01-3-00001.x
Self-aligned UMOSFET's with a specific on-resistance of 1 m&#937;.cm 2

This paper describes an improved UMOSFET with an ultralow specific on-resistance. This device utilizes a self-aligned process that permits closely spaced vertical trench gates with a unit cell of 6 µm. This allows for a remarkable increase of channel density and, therefore, reduces the on-resistance per unit area significantly. Experimental devices have been fabricated, and a specific on-resistance of 1.0 mΩ . cm2with a breakdown voltage of 30 V has been achieved. This specific on-resistance is the lowest value ever reported for FET's.
Optimal management of non-Markovian biological populations

Abstract Wildlife populations typically are described by Markovian models, with population dynamics influenced at each point in time by current but not previous population levels. Considerable work has been done on identifying optimal management strategies under the Markovian assumption. In this paper we generalize this work to non-Markovian systems, for which population responses to management are influenced by lagged as well as current status and/or controls. We use the maximum principle of optimal control theory to derive conditions for the optimal management such a system, and illustrate the effects of lags on the structure of optimal habitat strategies for a predator–prey system.
Effects of in vivo treatments on the activity of nitrogenase isolated from Rhodospirillum rubrum

Abstract Nitrogenase activities of partially purified extracts of Rhodospirillum rubrum grown on different nitrogen sources were examined. Most of the nitrogenase from cells grown on N2 or glutamate was in the inactive form. This form was also predominant in extracts from cells grown on limiting N2 or glutamate plus N2. The enzyme from cells grown with limiting NH+4 was fully active. Nitrogenase displayed varying degrees of sensitivity to in vivo inhibition by NH+4, depending on the culture conditions. However, addition of NH+4 to the cultures prior to harvest did not change the proportion of the active form of the enzyme in extracts from that found in control samples. Several of these observations are inconsistent with the three component model of nitrogenase regulation of Yoch and Cantu (Yoch, D.C. and Cantu, M. (1980) J. Bacteriol, 142, 899–907). A regulatory system controlled by products of NH+4 assimilation is suggested.
Daunomycin disrupts nuclear assembly and the coordinate initiation of DNA replication in Xenopus egg extracts

We have used Xenopus egg extracts to investigate the effects of the antitumor drug daunomycin on DNA replication in vitro. Xenopus sperm nuclei replicated nearly synchronously in our egg extracts, thereby allowing us to determine the effects of the drug on both replication initiation and elongation. Titration experiments demonstrated that daunomycin effectively inhibited replication in the extract, with 50% inhibition at a total drug concentration of 2.7 microM. However, a high concentration of daunomycin (50 microM) also inhibited nuclear envelope assembly, a prerequisite for the initiation of replication in this system. Therefore, to bypass the effects of daunomycin on nuclear envelope assembly, sperm nuclei were preassembled in extract prior to drug addition. Initiation of replication in preassembled nuclei was also inhibited by daunomycin, with 50% inhibition at a drug concentration of 3.6 microM. At low drug concentrations, where replication did occur, the synchrony of initiations within individual nuclei was lost. This drug-induced disruption of initiation events may provide important clues regarding the mechanism(s) by which these events are coordinated in eukaryotic cells. Daunomycin also inhibited replication elongation in preassembled, preinitiated nuclei. However, the concentration of drug required for 50% inhibition of elongation was nearly fourfold higher than the required for inhibition of initiation. Taken together, these data demonstrate that Xenopus egg extract can be used to investigate the effects of DNA-binding antitumor drugs on a number of interrelated cellular processes, many of which are less tractable in whole cell systems.
Pseudo-random generation from one-way functions

We show that the existence of one-way functions is necessary and sufficient for the existence of pseudo-random generators in the following sense. Let ƒ be an easily computable function such that when x is chosen randomly: (1) from ƒ(x) it is hard to recover an x1 with ƒ(x1) = ƒ(x) by a small circuit, or; (2) ƒ has small degeneracy and from ƒ(x) it is hard to recover x by a fast algorithm. From one-way functions of type (1) or (2) we show how to construct pseudo-random generators secure against small circuits or fast algorithms, respectively, and vice-versa. Previous results show how to construct pseudo-random generators from one-way functions that have special properties ([Blum, Micali 82], [Yao 82], [Levin 85], [Goldreich, Krawczyk, Luby 88]).We use the results of [Goldreich, Levin 89] in an essential way.
On the dendritic topology and activation of cockroach giant interneurons

Abstract Each cercus of Periplaneta americana has 650 to 750 sensilla. The smaller cercal nerve contains about 1000 fibres; the larger contains about 2500. Many of these are under 0·5 μm in diameter. The sensilla found to be most effective in driving the giant fibres were cercal thread hairs and cercal bristle hairs. The cercal nerve tract leads directly into the dendritic trees of the giant interneurons. The dendritic trees of two giant interneurons were filled with Procion Yellow dye. Both display very extensive ipsilateral (to axon) ramification through a large volume of neuropile of the last abdominal ganglion. The location and extent of ramification of the two dendritic trees differs markedly, indicating that the two giant interneurons probably mediate different integrative activities. One of the giant fibres is attached to a single neuron soma, demonstrating that, at least in one case, the giant interneurons are not syncitial.
Chemotherapy advances in locally advanced head and neck cancer

The management of locally advanced unresectable head and neck squamous cell cancer (HNSCC) continues to improve. One of the major advances in the treatment of HNSCC was the addition of chemotherapy to radiation in the treatment of non-surgical patients. The majority of the data regarding chemotherapy in HNSCC involve cisplatin chemotherapy with concurrent radiation. However, several new approaches have included targeted therapy against epidermal growth factor receptor and several recent studies have explored the role of induction chemotherapy in the treatment of HNSCC. The purpose of this article is to provide an overview of the role of chemotherapy in the treatment of locally advanced HNSCC.
Synthesis and characterization of extended rod thermotropic polyesters with polyoxyethylene pendant substituents

Abstract The liquid crystalline properties of a series of aromatic polyesters prepared from alkoxy and alkoxyethyleneoxy-substituted hydroquinone monomers and either terephthaloyl chloride or diphenyl terephthalate were studied by optical and thermal methods. The melting temperatures of these polymers were considerably less than the corresponding polymers with n-alkyl substituents with the same number of atoms in the pendant substituent group on the hydroquinone ring. The melting temperature decreased in an exponential manner with the increase in the number of atoms in the alkoxy substituents, and at some temperature above their melting transition, a transition from a highly threaded liquid crystalline texture to a highly birefringent schlieren liquid crystalline texture was observed to occur for all polymers. All polymers except one were also observed to become homeotropic at elevated temperatures. When cooled from the homeotropic melts, a nematic glass was observed to form for the majority of polymers. Two polymers, on cooling from homeotropic melts to room temperature, showed optical textures representative of Williams domains which formed without the application of any electrical field.
Race, populations, and genomics: Africa as laboratory

Much of the recent debate over race, genetics, and health has focused on the extent to which typological notions of race have biological meaning. Less attention, however, has been paid to the assumptions about the nature of "populations" that both inform contemporary biological and medical research and that underlie the concept of race. Focusing specifically on Africa in the 1930s and 1940s, this paper explores the history of how fluid societies were transformed into bounded units amenable to scientific analysis. In the so-called "Golden Age of Ethnography," university-trained social anthropologists, primarily from Britain and South Africa, took to the field to systematically study, organize, and order the world's diverse peoples. Intent on creating a scientific methodology of neutral observation, they replaced amateur travelers, traders, colonial administrators, and missionaries as authoritative knowledge producers about the customs, beliefs, and languages of indigenous peoples. At the same time, linguists were engaged in unifying African languages and mapping language onto primordial "tribal" territories. We argue that the notion of populations or "tribes" as discrete units suitable for scientific sampling and classification emerged in the 1930s and 1940s with the ethnographic turn in social anthropology and the professionalization and institutionalization of linguistics in Western and South African universities. Once named and entered into international atlases and databases by anthropologists in the U.S., the existence of populations as bounded entities became self-evident, thus setting the stage for their use in large-scale population genetic studies and the contemporary reinvigoration of broad claims of difference based on population identification.
Mass spectra of silicon containing industrial gases

Abstract In this work we present mass spectra of Si-containing gases which are used in electronic industry for the chemical vapor deposition of thin layers of silicon. Mass spectra of SiCl 2 H 2 , SiCl 3 H, and SiCl 2 represent new data. Mass spectra of SiH 4 , Si 2 H 6 , and SiCl 4 were also determined and compared to the literature data.
Ionic and structural effects on the thermal helix‐coil transition of DNA complexed with natural and synthetic polyamines

Polyamines are ubiquitous cellular components that interacts strongly with nucleic acids. Although many of the interactions of oligocations with DNA can be rationalized with polyelectrolyte theories that treat counterions as point charges, some structural effects are evident. We have explored the effects of polyamine structure on one important aspect of DNA behavior, its thermal melting transition, by using a series of spermidine analogs NH3(CH2)3NH2(CH2)nNH, where n varies from 2 to 8 [Jorstad et al. (1980) J. Bacteriol.141, 456–463]. For spermidine itself, n = 4. Tm for calf-thymus DNA in the presence of each of these analogs, and the other naturally occurring polyamines putrescine2+ and spermine4+, was measured over a wide range of NaCl concentrations and polyamine:DNA phosphate ratios. There are modest, but significant structural effects. particularly with the shorter n = 2 and 3 derivatives, whose geometry my not allow full electrostatic interaction with DNA. Longer analogs, on the other hand, are not much different than spermidine in their effects on Tm, though a moderate maximum occurs at n = 5. Since polyamines are important in the cellular condensation and packaging of DNA, we have also delineated the critical polyamine and salt concentrations that are required to cause DNA aggregation. Here again, there are significant structural effects, which are not easily rationalized by any simple considerations.
Effect of 1-(o-chlorophenyl)-1-(p-chlorophenyl)-2,2-dichloroethane on adrenocorticotropic hormone-induced steroidogenesis in various preparations in vitro of dog adrenal cortex

Abstract Studies in the intact dog revealed that the intravenous administration of 60 mg/kg of 1-(o-chlorophenyl)-1-(p-chlorophenyl)-2,2-dichloroethane (o,p′-DDD) inhibited ACTH-induced steroid production by greater than 90 per cent within 2 hr. Similar results were noted in perfused adrenals and adrenal slices obtained from o,p′-DDD-treated dogs in vivo. In these preparations, baseline steroid production was unaffected by o,p′-DDD treatment. Incubation of adrenal slices from control dogs in either Krebs-Ringer bicarbonate-glucose buffer (KRBG) of plasma containing o,p′-DDD for as long as 16 hr did not block the adrenal responsiveness to ACTH. Ligation of the blood supply to the liver or gastrointestinal tract had no effect on the ACTH-inhibitory actions of the drug when administered in vivo. A 2-hr retrograde perfusion of adrenals with KRBG or plasma containing o,p′-DDD almost completely abolished the response to ACTH. In adrenals perfused with plasma containing both a maximally stimulating concentration of ACTH and o,p′-DDD, steroid production fell at approximately the same rate as was observed in the intact dog. Thus, o,p′-DDD was found to be effective in an adrenal preparation in vitro. The drug is not effective in the adrenal slice, probably because it does not penetrate to the interior of the slice. These studies suggest that either o,p′-DDD per se is the active principle in inhibiting ACTH-induced steroidogenesis or the active principle is formed within the adrenal gland.
Predictive power of systolic function and congestive heart failure in patients with patients admitted for chest pain without ST elevation in the troponin era

Background Impaired systolic function and congestive heart failure (CHF) are powerful predictors of adverse outcomes in patients with myocardial infarction (MI). However, there are little data in which both of these variables were assessed in heterogenous patients admitted from the emergency department for exclusion of ischemia. Methods Consecutive patients admitted for MI exclusion who had ejection fraction (EF) measured were included. Systolic dysfunction was defined as EF Results Of the 4,343 consecutive patients admitted, 3,682 (85%) had EF assessed (including 97% of the troponin I [TnI]–positive patients) and were included. One-year unadjusted mortality was 9.5%, but in the presence of systolic dysfunction or CHF, it increased to 22% and 26%, respectively. The most important multivariate predictors of 30-day and 1-year mortality were similar and included CHF (OR for 1-year mortality 2.5, 95% CI 1.9-3.4), TnI elevations (OR 2.0, 95% CI 1.5-2.6), and severe renal failure (OR 5.2, 95% CI 3.7-7.2). Systolic dysfunction was predictive of 1 year (OR 1.9, 95% CI 1.4-2.5) but not 30-day mortality. Results were similar in the 3,018 patients who were troponin-negative. Conclusions Congestive heart failure is an independent predictor of both short- and long-term mortality in patients admitted for MI exclusion. In contrast, systolic dysfunction predicts long-term but not short-term mortality. One cannot be used as a surrogate for the other.
Consistency between maternal employment attitudes and employment status

The stability of mothers' attitudes toward employment, employment status, and consistency between employment attitudes and behavior over a 15-month period was examined. Factors such as family finances, availability of child care, and child's health status that could influence either employment attitudes or employment behavior were explored. Mothers of preterm infants (N = 98) and mothers of full-term, healthy infants (N = 101) completed questionnaires regarding home/employment orientation, choice and satisfaction with the employment decision, and employment behavior as part of a battery of instruments administered when their infants were 3, 9, and 18 months old. Analyses indicated considerable stability in attitudes, behaviors, and consistency over a 15-month period for mothers of both full-term and preterm infants. Consistency groups were created based on employment status (employed versus not employed) and consistency status (consistent versus inconsistent) at each time point. Consistency groups differed on ratings of financial need and availability of child care.
Prioritizing Infrastructure Maintenance and Rehabilitation Activities under various Budgetary Scenarios: Evaluation of Worst-First and Benefit–Cost Analysis Approaches

Infrastructure maintenance and rehabilitation (M&R) projects are commonly prioritized by using the worst-first (W-F) and benefit-cost analysis (BCA) approaches. While many acknowledge the inherent disadvantages of the W-F approach relative to that of the BCA, many transportation and public works agencies still use the W-F approach. W-F and BCA approaches were compared in regard to their impact on network condition (specifically, lane miles in good condition and backlog) under various budgetary scenarios. These comparisons were motivated by the premise that under certain budget allocation and availability scenarios, the shortcomings of the W-F approach might be abated. The analysis presented used highway pavement network data from the Bryan District of the Texas Department of Transportation. The Bryan District is located in east central Texas (wet-warm climate and generally poor subgrade). In 2011, this network consisted of approximately 3,178 roadbed centerline miles. Results suggest that when M&R share a...
Effects of molecular organization on photophysical and photochemical behavior: Quenching by subphase iodide of fluorescence in pyrene-bearing probes at the nitrogen-water interface☆

Abstract The quenching by subphase iodide of pyrene covalently bound to amphiphatic molecules in spread monolayers has been measured. The probes employed were 2-(6-pyreneylhexanoyl)-3-palmitoyl-sn-glycero-1-phosphorylcholine, 10-(6(8)-octadecylpyrenyl) decanoic acid and 1-pyrenedocosanoic acid; the host lipids utilized were dioleoylphosphatidylcholine (DOL) and dipalmitoylphosphatidylcholine (DPL). It has been observed in all cases that pyrene fluorescence is significantly quenched in the uncompressed layer and that this quenching diminishes markedly as the surface pressure is increased over the liquid expanded region. Beyond this range a plateau in the fluorescence decay is reached in DOL, while in DPL changes in quenching are related to phase transitions. These findings indicate significant probe-water interaction at low surface pressure. Residual iodide quenching in DOL above 10 dyn cm −1 indicates some continued water-probe contact which may be due to the liquid character of the host layer and the double-bond character of the lipid while the very small residual quenching in DPL suggests tight packing in the non-liquid phases.
Synthesis of a multifunctional radioiodinatable photoaffinity probe

Abstract Synthesis is described which results in an iodinatable photoaffinity probe and derivatives which are useful in the covalent coupling of the probe to amine, carboxylic acid, and alcoholic hydroxy function on specific ligands of biological importance. Specific examples of natural product derivatization from terrestrial and marine sonrces are given.
Moving beyond species-discharge relationships to a flow-mediated, macroecological theory of fish species richness

AbstractHydrologic indices can be used in macroecological models of fish species richness. I used fish distributions and river flow records from 89 river basins in the Pacific Northwest (USA) to identify robust associations between aspects of flow and fish species richness. I calculated 148 hydrologic indices for each basin, created single-predictor regression models for each hydrologic index, and tested for significant relationships between native fish species richness and specific components of flow. I used multiple regression to test the significance and fit of models that combined hydrologic indices that were not highly collinear indices. Significant linear relationships (p ≤ 0.05) were detected for 85 indices. Coefficients of determination (r2) ranged from 0.04 to 0.33 (median = 0.19, coefficient of variation [CV] = 0.55). I identified 2 multiple-regression models, each including 3 hydrologic indices, as best based on information-theoretic model comparisons. One included median large flood rise rate,...