cssi/SciSciGPT-SciSciNet huggingface dataset:
Rapid Activation of Transducin by Mutations Distant From the Nucleotide-Binding Site: Evidence for a Mechanistic Model of Receptor-Catalyzed Nucleotide Exchange by G Proteins

Abstract G proteins act as molecular switches in which information flow depends on whether the bound nucleotide is GDP (“off”) or GTP (“on”). We studied the basal and receptor-catalyzed nucleotide exchange rates of site-directed mutants of the α subunit of transducin. We identified three amino acid residues (Thr-325, Val-328, and Phe-332) in which mutation resulted in dramatic increases (up to 165-fold) in basal nucleotide exchange rates in addition to enhanced receptor-catalyzed nucleotide exchange rates. These three residues are located on the inward facing surface of the α5 helix, which lies between the carboxyl-terminal tail and a loop contacting the nucleotide-binding pocket. Mutation of amino acid residues on the outward facing surface of the same α5 helix caused a decrease in receptor-catalyzed nucleotide exchange. We propose that the α5 helix comprises a functional microdomain in G proteins that affects basal nucleotide release rates and mediates receptor-catalyzed nucleotide exchange at a distance from the nucleotide-binding pocket.
Column chromatograpy of nucleotides on QAE-Sephadex

Abstract Chromatographic separation of mixtures of nucleoside mono-, di-, and triphosphates is readily accomplished on columns of QAE-Sephadex by elution with a gradient of 0–0.4 M NaCl at pH 9.7.
Prolotherapy: A Clinical Review of Its Role in Treating Chronic Musculoskeletal Pain

Prolotherapy is a technique that involves the injection of an irritant, usually a hyperosmolar dextrose solution, typically in the treatment of chronic painful musculoskeletal conditions. Despite its long history and widespread use as a form of complementary therapy, there still are disparities over its optimal indications and injection preparations. There are, however, numerous studies available regarding the use and efficacy of prolotherapy for various musculoskeletal conditions. The most frequently published indication is in the treatment of chronic low back pain, but there are recent studies that examined its use in the management of refractory tendinopathies as well as osteoarthritis. There is growing evidence to suggest that prolotherapy may be helpful in treating chronic low back pain when coupled with adjunctive therapies, such as spinal manipulation or corticosteroid injections. There is also evidence to suggest that prolotherapy is effective in treating refractory tendinopathies, particularly for lateral epicondylosis and Achilles tendinopathy. Additional larger, randomized controlled trials are needed to make specific recommendations regarding ideal protocols and indications. There is emerging evidence for the use of prolotherapy as a treatment option for osteoarthritis; however, further studies are needed to conclusively demonstrate its efficacy. Overall, prolotherapy remains a promising option for the treatment of painful musculoskeletal conditions, particularly when other standard treatments have proved ineffective.
Lutheran antigens, CD44-related antigens, and Lutheran regulatory genes

Summary The Lutheran (Lu) blood group antigens are a family of human erythrocyte antigens which reside on two closely related erythrocyte integral membrane proteins. Sixteen Lutheran or so-called para-Lutheran antigens have thus far been described, and human antisera to many of them have been shown to immunoblot two proteins, of 78 and 85 kDa. Lu cDNA encodes an integral membrane protein of 597 amino acids that is a member of the Ig superfamily. Lu proteins comprise five Ig superfamily domains, along with a single transmembrane domain and a cytoplasmic domain of about 60 amino acids. The two proteins seen in biochemical studies of red cell membranes appear to be derived from 2 mRNA species that differ only in their 3′ ends, suggesting that they arise from alternate splicing of a single preRNA. Three genetic backgrounds for the Lu(a-b-) [Lu null]phenotype have been described. A recessive Lu null phenotype is rarely observed as a result of homozygosity for two amorphic LU alleles. However, the most common Lu(a-b-) phenotype appears to be caused by an independently segregating, dominant gene, designated In (Lu) , which inhibits expression of all Lutheran antigens to nearly undetectable levels. This gene also affects the expression of other cell surface proteins and blood group antigens that are genetically unlinked to the Lutheran locus, including CD44 and MER2. CD44, a member of the cartilage link family of proteins, bears the In and AnWj blood group antigens. A widely distributed protein CD44 is expressed at normal levels on all tissues except erythrocytes in the presence of the In (Lu) gene. A second Lutheran regulatory gene, XS2 , is responsible for the third Lu(a-b-) phenotype, which exhibits an X-linked inheritance pattern. The XS2 gene down-regulates but does not abolish expression of LU genes and does not affect expression of CD44.
Thermal expansion op NbSe2 and TaS2

Abstract The lattice parameters a 0 and c 0 of the hexagonal 2H polytype of NbSe 2 ; have been measured over the temperature range 156–478 K for a 0 , and 138–482 K for c 0 . The lattice parameter c 0 of the hexagonal 2 H polytype of TaS 2 has been measured between 151 and 472 K. The lattice parameters a 0 and c 0 for the octahedral 1 T polytype of TaS 2 been measured between 165 and 488 K. Over these temperature ranges, the following average coefficients of thermal expansion have been measured; 2 H -NbSe 2 , 6.6 × 10 −6 K −1 along the a-axis, 19.9 × 10 −6 K −1 along the c-axis; 2 H -TaS 2 , 15.6 × 10 −6 K −1 along the c-axis; I T -TaS 2 , 12.7 × 10 −6 K −1 along the c-axis. The parameter c 0 of 1 T -TaS 2 undergoes two transitions which may be explained in terms of charge density waves.
Functional replacement of a retroviral late domain by ubiquitin fusion.

Retroviral Gag polyprotein precursors are both necessary and sufficient for the assembly and release of virus-like particles (VLPs) from infected cells. It is well established that small Gag-encoded motifs, known as late domains, promote particle release by interacting with components of the cellular endosomal sorting and ubiquitination machinery. The Gag proteins of a number of different retroviruses are ubiquitinated; however, the role of Gag ubiquitination in particle egress remains undefined. In this study, we investigated this question by using a panel of equine infectious anemia virus (EIAV) Gag derivatives bearing the wild-type EIAV late domain, heterologous retroviral late domains or no late domain. Ubiquitin was fused in cis to the C-termini of these Gag polyproteins, and the effects on VLP budding were measured. Remarkably, fusion of ubiquitin to EIAV Gag lacking a late domain (EIAV/ΔYPDL-Ub) largely rescued VLP release. We also determined the effects of ubiquitin fusion on the sensitivity of particle release to budding inhibitors and to depletion of key endosomal sorting factors. Ubiquitin fusion rendered EIAV/ΔYPDL-Ub sensitive to depletion of cellular endosomal sorting factors Tsg101 and Alix and to overexpression of dominant-negative fragments of Tsg101 and Alix. These findings demonstrate that ubiquitin can functionally compensate for the absence of a retroviral late domain and provide insights into the host-cell machinery engaged by ubiquitin during particle egress.
Warm and hot carriers in silicon surface-inversion layers

A study of the hot-carrier effects for electrons in silicon inversion layers is reported. Measurements of the warm-electron coefficient $\ensuremath{\beta}$ at 77 \ifmmode^\circ\else\textdegree\fi{}K give - 2 \ifmmode\times\else\texttimes\fi{} ${10}^{\ensuremath{-}8}$ ${\mathrm{cm}}^{2}$/${\mathrm{V}}^{2}$ in the 〈110〉 and - 5 \ifmmode\times\else\texttimes\fi{} ${10}^{\ensuremath{-}8}$ ${\mathrm{cm}}^{2}$/${\mathrm{V}}^{2}$ in the 〈100〉 direction on a (110) silicon surface. A theory of $\ensuremath{\beta}$ is given for the two-dimensional carrier gas model. The two-dimensional Boltzmann equation is solved in the diffusion approximation. Explicit results for the distribution function are given for scattering of the electrons by acoustic phonons, surface roughness, and optical phonons as well as for scattering by combined acoustic phonons and surface charges. The current-voltage characteristics is also calculated for high electric fields using a Maxwellian distribution with electron temperature ${T}_{e}$. These results are compared with experimental values obtained in this paper and those given by Fang and Fowler.
Effects of organophosphates on the visual system of rats

The possibility that exposure to organophosphate insecticides can lead to ocular damage is suggested by Japanese studies from the 1960s and 1970s indicating that exposed humans developed chronic ocular degeneration, in addition to showing more commonly accepted effects of cholinesterase-inhibiting compounds. Other papers reported ocular lesions in laboratory animals treated with organophosphates. More recently, retinal degeneration following chronic organophosphate treatment has been reported to the Environmental Protection Agency by pesticide manufacturers in studies conducted in compliance with good laboratory practice regulations. Several factors, however, have prompted scepticism regarding organophosphate-induced ocular toxicity, including the widespread use of organophosphate compounds for both agricultural and ophthalmological practices without numerous additional reports of comparable ocular toxicity. We are developing a research program to address these issues involving electrophysiological, biochemical and histological investigations of rats treated with organophosphate insecticides. The research program is young, but early results are available. Notably, retinas from rats treated with a single subcutaneous injection of 100 mg kg-1 fenthion showed decreases in carbachol-stimulated release of inositol phosphate, an indicator of cholinergically-mediated intracellular second messenger systems. These effects persisted at least 56 days after fenthion administration. This could indicate several different toxicological actions, which are currently under investigation. It is concluded that the possible association between exposure to organophosphates and ocular toxicity cannot be dismissed, and that several important research issues need to be resolved.
Binding of the non‐typeable Haemophilus influenzae lipooligosaccharide to the PAF receptor initiates host cell signalling

Non-typeable Haemophilus influenzae (NTHi) invades host cells by binding of the platelet-activating factor (PAF) receptor via lipooligosaccharide (LOS) glycoforms containing phosphorylcholine (ChoP). The effect of NTHi infection on host cell signalling and its role in NTHi invasion was examined. The infection of human bronchial epithelial cells with NTHi 2019 increased cytosolic Ca2+ levels, and the invasion of bronchial cells by NTHi 2019 was inhibited by pretreatment with the cell-permeant intracellular Ca2+ chelator BAPTA-AM (P = 0.022) or thapsigargin (P = 0.016). Cytosolic inositol phosphate (IP) levels were also increased after infection with NTHi 2019 (P < 0.001), but not after infection with isogenic mutants expressing altered LOS glycoforms lacking ChoP. PAF receptor antagonist reduced NTHi 2019-stimulated IP production in a dose-dependent manner. NTHi 2019 invasion was inhibited by pertussis toxin (PTX) and the phosphatidylinositol-3-kinase inhibitors wortmannin and LY294002. The less invasive strain NTHi 7502 also initiated IP production, but was unaffected by PAF receptor antagonist or PTX. These data demonstrate that the binding of the PAF receptor by NTHi initiates receptor coupling to a PTX-sensitive heterotrimeric G protein complex, resulting in a multifactorial host cell signal cascade and bacterial invasion. Moreover, the data suggest that NTHi strains initiate cell signalling and invade by different mechanisms, and that invasion mediated by PAF receptor activation is more efficient than macropinocytosis.
Infrared-divergence problem: Relation of the Zwanziger ansatz to the Dollard-Kulish-Fadde'ev approach

A simple relation is derived between the ansatz for the asymptotic distorted electron field recently suggested by Zwanziger and the electron field associated with a suitable asymptotic Hamiltonian as required by Dollard and by Kulish and Fadde'ev for an infrared-divergence-free quantum electrodynamics. (AIP)
The cost allocation issue in joint replenishment

Abstract Joint replenishment for several products to achieve a lower inventory logistics cost has been a topic of extensive studies. Less attention has been paid to the issue of deciding how the joint replenishment costs should be allocated across the individual products. Ideally, when items are ordered together one would require a stable cost allocation, such that no subset of products subsidizes another subset. When part of each product's ordering cost is product specific and part can be shared with other products (like in a 3PL setting of Anily and Haviv), it has been shown that even when a stable allocation exists, such an allocation might be difficult to compute. In addition, usually the components of ordering costs are partially determined using estimates and accounting discretion. This paper provides two main insights for determining an appropriate cost allocation. It provides the means to test how sensitive a stable cost allocation is to a range of cost parameter values. Then, in a computational study, it is shown how to obtain a stable cost allocation without excessive computation.
Utility theory with probability-dependent outcome valuation

This paper provides an axiomatic characterization of a class of nonexpected utility models of decision making under risk. It formalizes the notion that the valuation of outcomes may depend on the probability measure in whose support the outcomes are contained and defines a transformation of the space of risky prospects taking account of these probability-dependent valuations. The von Neumann-Morgenstern axioms are imposed on the preference relation among the transformed risky prospects to obtain a representation that is nonlinear in the probabilities. Some implications of the resulting models are pointed out using local expected utility analysis.
Market structure and incomplete information: Price formation in a real-world repeated English auction

Abstract This paper examines the effect of buyer size on price formation in an English auction of used state police cars. While open auctions generally favor competitive pricing, Bikhchandani (1988) develops a model of a second-price, common value auction in which bidders can use strategic behavior based on repeated sales to develop an aggressive reputation and, as a result, pay lower prices in equilibrium. The paper tests this hypothesis by examining sales of 340 used automobiles sold at 13 public auctions conditional on the volume of purchases made by the three largest buyers at the auctions. The empirical results show that the number of buyers plays a stronger role in price formation than does buyer size.
Influence of ocean heat transport on the climate of the Last Glacial Maximum

A series of climate simulations using an atmospheric general circulation model shows that maintaining ocean heat transport at close to present-day values, but with otherwise glacial boundary conditions, leads to an enhanced cooling, particularly in the tropics. This is in agreement with recent geochemical evidence from fossil corals, ground waters, and ice. Near-modern ocean heat transport may have been sustained in all ocean basins during the Last Glacial Maximum in order to balance the formation and export of Glacial North Atlantic Intermediate Water.
PURIFICATION AND PROPERTIES OF DIHYDROFOLATE REDUCTASE OF SHEEP LIVER.

Abstract 1. 1. Dihydrofolate reductase (5,6,7,8-tetrahydrofolate: NAD (P) oxidoreductase, EC 1.5.1.3) of sheep liver has been purified over 400 fold to a specific activity of about 65 mμmoles of dihydrofolate reduced per ml per min per mg of protein. 2. 2. The optimum activity of the enzyme is at pH 5.5 with either NADPH or NADH. NADPH is the more effective electron donor. Contamination with a transhydrogenase has been excluded as the explanation for the participation of NADH. The relative ineffectiveness of NADH appears to be related to its slower rate of association with the enzyme. The Km values for NADPH and NADH were estimated to be 1.7 · 10−6 M and 0.8 · 10−4 M, respectively, at pH 7.0. 3. 3. The purified dihydrofolate reductase catalyzes the reduction of folic acid with a pH optimum with NADPH at 4.5. No reduction was measurable with NADH. The enzymic reduction of dihydrofolate is competitively inhibited by folate, with an estimated Kj of 4.2 · 10−8 M. Suggesteve evidence is presented that a single enzyme reacts with both dihydrofolate and folate. 4. 4. The product of the enzymic reduction has been shown to be the L -(−)diastereoisomer of tetrahydrofolate by its reactivity in the thymidylate synthetase system. 5. 5. The enzyme catalyzes the reduction of various pteroyl and dihydropteroyl derivatives and also of certain dihydropteridines. Activity decreases as the length of the non-pteridine side chain is decreased. 6. 6. The purified enzyme has been employed as a means of distinguishing between several possible tautomeric forms of the pyrazine ring of dihydropteridine derivates. 6-Methyl-7,8-dihydropteridine, prepared by a presumably authentic method of synthesis is reduced in the enzyme system. Dihydrofolate prepared by oxidation of tetrahydrofolate with 2,6-dichlorophenolindophenol is not a substrate for the enzyme. 7. 7. The temperature characteristics of the enzyme have been investigated.
Up-regulation of guinea pig myometrial β-adrenoreceptors by systemic estradiol and progesterone

The effects of systemic administration of 17 beta-estradiol (E2) and progesterone (P) on the concentration and affinity of myometrial beta-adrenoreceptors were studied in non-pregnant, previously oophorectomized guinea pigs receiving a continuous infusion of E2, P, a combination of the two hormones, or placebo for 7 days. Myometrial beta-adrenoreceptors were characterized by using (-)-[125I-cyanopindolol as the specific beta-adrenoreceptor ligand. Compared to that in the control group, E2 administration resulted in a 7-fold increase in the density of myometrial beta-adrenoreceptors. Administration of P alone resulted in a significant increase in both beta-adrenergic receptor concentration and the receptor dissociation constant (Kd). Finally, a combination of E2 and P treatment did not result in any synergistic or additive effect for the beta-adrenergic receptors, while the Kd was twice that of the control or E2-treated animals. We conclude that systemic administration of these sex steroid hormones, directly or indirectly, modulates myometrial beta-adrenergic receptor concentrations and their ligand affinity.
Two-Dimensional Measurements of Ocean Microstructure: The Role of Double Diffusion

Abstract Two-dimensional measurements of ocean microstructure are reported from four cruises to the Atlantic and Pacific. A Neil Brown Instrument Systems CTD has been modified to enhance its capability in the microstructure regime by replacing the standard thermistor with a Thermometrics FP07 “7-ms” thermisor, by separately digitizing the temperature channels at 50 Hz, and by using a unique passive-motion compensation device to obtain a uniform descent rate. The resulting instrumentation system measures the centimeter-scale temperature and conductivity signature of microstructure and the salinity structure over scales of a few tens of centimeters. Numerous observations of flat patches of microstructure of order several meters in the vertical and hundreds of meters in the herizontal are reported at sites of temperature-stabilized salinity inversions and salinity-stabilized temperature inversions, indicating active double-diffusive mixing. Finescale computation of the density ratio (Rρ = αTz/βSz) over verti...
Solar wind contribution to surficial lunar water: Laboratory investigations

Remote infrared spectroscopic measurements have recently re-opened the possibility that water is present on the surface of the Moon. Analyses of infrared absorption spectra obtained by three independent space instruments have identified water and hydroxyl (–OH) absorption bands at � 3 lm within the lunar surface. These reports are surprising since there are many mechanisms that can remove water but no clear mechanism for replenishment. One hypothesis, based on the spatial distribution of the –OH signal, is that water is formed by the interaction of the solar wind with silicates and other oxides in the lunar basalt. To test this hypothesis, we have performed a series of laboratory simulations that examine the effect of proton irradiation on two minerals: anorthite and ilmenite. Bi-directional infrared reflection absorption spectra do not show any discernable enhancement of infrared absorption in the 3 lm spectral region following 1 or 100 keV proton irradiation at fluences between 10 16 and 10 18 ions cm � 2 . In fact, the
Elucidation of post-PKS tailoring steps involved in landomycin biosynthesis.

The functional roles of all proposed enzymes involved in the post-PKS redox reactions of the biosynthesis of various landomycin aglycones were thoroughly studied, both in vivo and in vitro. The results revealed that LanM2 acts as a dehydratase and is responsible for concomitant release of the last PKS-tethered intermediate to yield prejadomycin (10). Prejadomycin (10) was confirmed to be a general pathway intermediate of the biosynthesis. Oxygenase LanE and the reductase LanV are sufficient to convert 10 into 11-deoxylandomycinone (5) in the presence of NADH. LanZ4 is a reductase providing reduced flavin (FMNH) co-factor to the partner enzyme LanZ5, which controls all remaining steps. LanZ5, a bifunctional oxygenase–dehydratase, is a key enzyme directing landomycin biosynthesis. It catalyzes hydroxylation at the 11-position preferentially only after the first glycosylation step, and requires the presence of LanZ4. In the absence of such a glycosylation, LanZ5 catalyzes C5,6-dehydration, leading to the production of anhydrolandomycinone (8) or tetrangulol (9). The overall results provided a revised pathway for the biosynthesis of the four aglycones that are found in various congeners of the landomycin group.
Detection prospects for GeV neutrinos from collisionally heated gamma-ray bursts with IceCube/DeepCore.

Jet reheating via nuclear collisions has recently been proposed as the main mechanism for gamma-ray burst (GRB) emission. In addition to producing the observed gamma rays, collisional heating must generate 10--100 GeV neutrinos, implying a close relation between the neutrino and gamma-ray luminosities. We exploit this theoretical relation to make predictions for possible GRB detections by $\mathrm{\text{IceCube}}+\mathrm{\text{DeepCore}}$. To estimate the expected neutrino signal, we use the largest sample of bursts observed by the Burst and Transient Source Experiment in 1991--2000. GRB neutrinos could have been detected if $\mathrm{\text{IceCube}}+\mathrm{\text{DeepCore}}$ operated at that time. Detection of 10--100 GeV neutrinos would have significant implications, shedding light on the composition of GRB jets and their Lorentz factors. This could be an important target in designing future upgrades of the $\mathrm{\text{IceCube}}+\mathrm{\text{DeepCore}}$ observatory.
Network sharing fairness function with consideration of priority levels

An important issue of computer network management is to distribute network resource fairly to its users. The first quantitative fairness score function F(x"1,x"2,...,x"n) was proposed in 1984 by Jain et al. [1] for evaluating network resource sharing fairness. Chen and Zhang (2005) [6] proposed another fairness score function G(x"1,x"2,...,x"n) which better fits the real world situation in some cases. This paper considers the situation that the users can have different priority levels. A modified fairness score function G^*(x"1,x"2,...,x"n;w"1,w"2,...,w"n) is proposed. The proposed fairness score function can deal with the situation that the network resource users have different priority levels, and can keep all the nice properties of G(x"1,x"2,...,x"n).
The Prandtl number effect in porous layer convection

A Prandtl number effect for natural convection in a horizontal porous layer is demonstrated to be an explanation for the difference in heat transfer between different porous systems. A Prandtl number trend in experimental data is identified and arguments are presented to substantiate a Prandtl number dependence. Finally, Nusselt number correlations of experimental data at different Prandtl numbers have been developed.
Mode of cholesterol ingestion and atherosclerosis in the young bovine

SUMMARY Varying degrees of atherosclerosis were noted in aortas and coronary arteries of calves fed high-cholesterol diets for 25 weeks. Intimal lipid was more extensive in aortas and circumflex coronary arteries from nonruminating calves fed cholesterol in a highfat, liquid (milk) diet than in arteries from ruminating calves fed cholesterol in low-fat (grain) diet. Cholesterol deposition was coextensive with the intimal lipid. Plasma and liver cholesterol levels were higher in calves fed cholesterol in the high-fat, liquid diet but variation in animal response was substantial. Digestibility data indicated that the low amount of fat in the diet of the calves receiving primarily grain depressed absorption of cholesterol. Moreover, exposure of cholesterol to digesta of the ruminoreticulum, as would occur in grain feeding, was shown by in vitro and in vivo observations to enhance degradation of cholesterol.
Validation and Uncertainty Analysis of Satellite Rainfall Algorithms

Satellites, while offering excellent spatial coverage, determine precipitation indirectly, using algorithms that transform satellite-sensed radiance (either emitted or scattered) from clouds or raindrops into precipitation. A large uncertainty is associated with satellite precipitation estimates, stemming from unknown variation in space and time of the physical and statistical relationships between precipitation and satellite-sensed radiance. To mitigate this, satellite algorithms must be calibrated and verified using surface precipitation sampled from different climate regimes and seasons. Recently developed statistical techniques have been used effectively to reduce spatial sampling error associated with sparsely distributed raingages and thereby improve our understanding of satellite algorithm quality. This paper provides an example of satellite precipitation validation, including a description of the types of satellite data used to estimate precipitation, as well as the results from a major project (the Global Precipitation Climatology Project [GPCP]), to estimate global precipitation through a combination of satellite and raingage products. In addition, a recently developed procedure to investigate spatial averaging, scaling, and uncertainty analysis will be used to examine the GPCP product. Specifically, uncertainty analysis applied to comparisons between satellite monthly rainfall estimates and rainfall estimates constructed from Pacific atoll-sited raingauge sites will be discussed.
Extending Limits on Neutral Heavy Leptons

Neutral leptons corresponding to "right-handed neutrinos" are expected in many grand unified theories of the electroweak strong interactions. At present, the experimental limits on the masses and mixings with ordinary neutrinos of these leptons are very poor for masses above about 1 GeV. Suggestions are made for extending these limits, in experiments involving the production of $b$ quarks, $W$ and $Z$ bosons, and any heavier gauge bosons that might exist, and via high-statistics studies of neutral-current neutrino interactions.
The recoil-free fraction for 182W in a sodium tungsten bronze

Abstract The recoil-free fraction ƒa of the 100.1-keV line of 182W was measured with the Mossbauer effect in an absorber of a tungsten bronze Na0.8WO3 at 4.2°K by the variation of line width thickness. The result is ƒ a = 0.18 ± 0.01 corresponding to θM = 298°K and rms zero-point motional amplitude R = 0.044 A . The amplitude is almost as small as that in tungsten itself and considerably smaller than the amplitudes in beryllium or diamond.
Riparian soil response to surface nitrogen input: Temporal changes in denitrification, labile and microbial C and N pools, and bacterial and fungal respiration.

Abstract To investigate potential changes in soil microbial characteristics of riparian zones subject to chronic nitrogen influx, we conducted an N-addition experiment in a riparian forest in the Coastal Plain of Georgia, USA. During 6 months, we quantified temporal changes in denitrification and respiration rates, microbial biomass, and bacterial and fungal activity, following single and repeated inorganic N additions to the near-stream zone (‘zone 1’) and the upslope area (‘zone 2’) within the riparian site. Zone 1 soil had significantly higher soil moisture, larger labile and microbial C and N pools, higher denitrification, bacterial and fungal respiration rates, and a lower pH than zone 2 soil. Over time, all added N was effectively removed from zone 1 soil by denitrification, regardless of whether N was added in a single large pulse or multiple small pulses. In contrast, added N did not significantly stimulate denitrification in zone 2 soil, which lacked sufficient anaerobicity and had lower labile C levels. In neither zone did N addition result in net N immobilization into microbial biomass, suggesting that microbial storage is not a major N-removal mechanism in this riparian forest. In both zones N additions slightly reduced microbial C and basal respiration, and increased fungal activity. Although bacterial activity was not significantly affected, the observation of increased bacterivorous nematode populations in N-amended soils suggests that bacterial production had been temporarily stimulated by N addition. However, it may be expected that long-term effects of chronic N influx mostly negatively affect microbial biomass and activity, which could threaten the seemingly indefinite N-removal potential of denitrifiers in N-loaded riparian systems.
Mechanism of the coagulopathy associated with acute promyelocytic leukemia

Robert Kaplan, Hematology Fellow, Department ofMedicine and Sol Sherry Thrombosis Research Center,Temple University School of Medicine: The patient is a64-year-old Caucasian female with a history of hyper-tension and diabetes mellitus who presented with a four-month history of weight loss and fatigue. Laboratoryevaluation revealed a pancytopenia initially suspected tobe related to her multiple medications. Despite changesin her therapeutic regimen, there was no significant im-provement in her blood cell counts. A subsequent bonemarrow aspirate revealed atypical promyelocytes withabundant Auer rods accounting for 35% of the marrowcells. Cytogenetic studies detected the t(15,17)(q
Testicular teratoma with nephroblastoma component.

We report the development of Wilms’ tumor in an atrophic testis and review the potential molecular pathogenesis. An 18-year-old man presented with 2 days of right testicular pain and growth in his atrophic testis. Ultrasonography revealed a heterogeneous mass. The chest radiographic findings and testicular tumor marker levels were normal. He underwent radical orchiectomy, with the pathologic examination showing teratoma with a nephroblastoma component, focal embryonal carcinoma, and minute yolk sac tumor. The development of Wilms’ tumor in the testis is rare and can be explained by the activation of the WT1 gene during embryogenesis.
Cobalamin and Thiamine in Long Island Sound: Patterns of Distribution and Ecological SIGNIFICANCE1

Cobalamin occurs in surface waters of Long Island Sound at high levels (to 16 µµg/ml) during the winter, falling markedly with the late winter diatom bloom and rising during the summer with temperature. The pattern of cobalamin and PO4-P concentrations are similar, both nutrients reflecting but not limiting phytoplankton growth. Thiamine is present only in barely detectable amounts in the main body of the Sound. Data suggest that thiamine, but not cobalamin, may be mainly derived from land drainage.
“Inappropriate” Physician Habits in Prescribing Oral Nifedipine Capsules in Hospitalized Patients *

Despite the absence of an approved Food and Drug Administration (FDA) indication, the use of oral or "sublingual" nifedipine for hypertension in the hospitalized patient has become an increasingly common practice. The purpose of the study was to assess the clinical circumstances for which the drug was being prescribed and the practices of attending and resident physicians. Dosing of oral nifedipine capsules in medical and surgical inpatients was studied prospectively in three central Connecticut hospitals (University, community-teaching, and private nonteaching) during a 60-day period from January to March, 1994. Through evaluation of computerized pharmacy and medical records, data were collected on diagnostic reasons for ordering nifedipine, pre- and posttreatment blood pressures, dosing frequency, clinical documentation associated with drug prescription, and adverse events. Physicians and nurses at the respective hospitals were unaware of the conduct of the study. The incidence of nifedipine capsule administration at all three hospitals was 3.4% (152 dosings in 83 patients/4489 hospitalized patients/ 60 days). Practice habits and blood pressure changes differed minimally among hospitals and physicians. Sixty-three percent of nifedipine orders were given over the telephone for arbitrary and asymptomatic blood pressure elevations and 98% of the orders lacked bedside patient evaluation. Follow-up of the blood pressure was performed within 1 h in 51% of patients and within 2 h in 24%, while in 25% there was no documentation of follow-up until 2 to 6 h after nifedipine dosing. Mean pretreatment blood pressure was 186/94 +/- 20/16 mm Hg (range: 150 to 260 mm Hg systolic and 50 to 125 mm Hg diastolic). Blood pressure fell 32/16 +/- 22/16 mm Hg (range: -92 to +8 mm Hg systolic and -90 to +28 mm Hg diastolic) and was related to the level of pretreatment blood pressure (r = 0.53 for systolic blood pressure, and r = 0.49 for diastolic blood pressure, P < .001 for both). Large, asymptomatic blood pressure reductions were common. One hypertensive patient experienced severe hypotension accompanied by an anterior wall myocardial infarction. These data demonstrate inappropriate physician prescribing of oral nifedipine in hospitalized patients characterized by a lack of proper assessment prior to drug dosing, highly arbitrary treatment parameters that were written without regard for symptoms or underlying illnesses, and slow follow-up for evaluation of the clinical response to therapy.
Interdiffusion Behavior in γ-Phase U-Mo Alloy versus Al-6061 Alloy Couples Fabricated by Friction Stir Welding

To better understand interactions between fuel and cladding in research reactor fuels, diffusion couples between γ-phase U-7 wt% Mo and U-10 wt% Mo alloy fuels and a Si-bearing, Al alloy were fabricated using a friction stir welding technique. The advantage of such a fabrication technique is that it can potentially reduce the amount of aluminum-oxide that might be present at the diffusion couple interface. The presence of oxides at the interface can affect the interdiffusion process. These couples were annealed and characterized using a scanning electron microscope equipped with energy-dispersive and wavelength-dispersive spectrometers. Images were taken of the developed diffusion structures; x-ray maps were generated to identify partitioning behavior of the various components; and, point-to-point analysis was employed to generate composition profiles and to determine phase compositions. To try and determine how the presence of Si in an Al alloy affects the interdiffusion behavior of fuel and cladding components in research reactor nuclear fuels, the results from this study were compared to those from earlier diffusion studies using U-Mo alloys and Al. The formed diffusion zones in some samples annealed for 30 minutes are comprised of Si-rich aluminide phases that appear to be (U,Mo)0.9(Al,Si)4 and (U,Mo)(Si,Al)2, based on composition. The diffusion rates observed and the types of phases that form can be correlated to the stability of the γ-U phase, which is a metastable phase. For a sample annealed for a much longer time, large diffusion structures formed and no Si-rich phases were observed.
Limitations imposed by ionospheric turbulence on satellite-to-satellite Doppler measurement accuracy

For some time the possibility has been considered to perform an accurate survey from orbit of the earth gravity field by making use of low-low, satellite-to-satellite Doppler tracking with a radio link which operates in the frequency band in the range from 50 to 100 GHz. It is, therefore, of interest to discuss the upper bound in Doppler measurement accuracy imposed by the effects of ionospheric turbulence. The present investigation is concerned with the measurement error induced by ionospheric turbulence. The assumptin is made that the so-called ionospheric refractive 'bias' can be removed with one of the multifrequency methods of the current practice.
A New Operative Procedure for Correction of Kinked Carotid Artery

The historical development of sur gical correction of the kinked carotid artery is traced. A new procedure for the straightening of the kinked ca rotid artery with atheromatous plaque and cannulation of the vessel to ensure cerebral perfusion during arteriotomy is presented.
Self-locked He-Ne ring laser

Experimental conditions necessary for self-pulsing to occur in a He-Ne ring laser are reported. These results are compared with predictions that are based upon theoretical models that have been presented in the literature. Good qualitative agreement is found in that theory and experiment both show that self-pulsing will only occur over a range of excitation. Quantitative results differed enough to indicate that additional refinement is needed even though the models have identified many of the important parameters involved.
Evaluation of a uniaxial, nonlinear, second-order differential overstress model for rate-dependence, creep and relaxation

Abstract The properties of a second-order differential equation linear in the first and second time derivatives of stress and strain but nonlinear in the overstress are investigated. The overstress is the difference between the stress and an equilibrium stress which corresponds to the limiting response in infinitely slow loading. The extension to second-order time derivatives in this nonlinear constitutive equations follows similar methods in linear viscoelasticity. The nonlinear overstress dependence of the coefficient functions is, however, maintained. The behavior of the second-order equation is compared with that of the first-order equation. Phaseplane analysis and Poincare-linearization are used to show that the first and second-order equations exhibit the same long time limits for constant stress(strain)-rate loading. Numerical integration involving strain(stress)-rates differing by four orders of magnitude and strain(stress)-rate jumps demonstrates that the limits are rapidly attained and that the transient behavior of the second-order equation can be different from that of the first-order equation. Strong and mild oscillatory behavior as well as monotonic behavior is possible in strain control. Stress control always results in monotonic behavior. For creep and relaxation the inelastic strain is a functional of the overstress history and the large time limit corresponds to that of the first-order equation. Unless very strong emphasis is placed on modeling unusual transient behavior, this second-order model does not appear to be more advantageous than the first-order model.
A formal description of users' knowledge of how to operate a device and user complexity

The terms "user friendliness," user complexity, and their numerous synonyms appear frequently in the popular press and the technical literature on human­ computer interaction. The claim that a particular system is user friendly makes nice advertising copy, but this term has not been adequately defmed in terms of more basic psychological constructs (Dehning, Essig, & Maass, 1981). Kieras and Polson (in press) developed a formal theory of user complexity that is the complement of user friendliness. They assumed that user complexity is a function of the amount and structure of the new knowl­ edge that a subject must acquire in order to learn to operate a new system or device, and they argued that an adequate theory of user complexity should incorporate a formal description of this knowledge. Furthermore, an investigator should be able to derive predictions of observed learning times and performance from the theory. This paper summarizes the theory of user complexity developed by Kieras and Polson (in press) and presents new experimental results that support the theory's pre­ dictions of learning times. The paper begins with a sum­ mary of previous relevant work. The next section describes the various components of a user's knowledge of how to operate a device. Two components of a user's knowledge, formalized as a production system, are described in the next three sections. Finally, the results of a study that shows that learning time is a linear func
Mozzarella cheese: impact of nonfat dry milk fortification on composition, proteolysis, and functional properties

Abstract The effects of fortifying milk with low heat NDM on the composition, proteolysis, and functional properties of Mozzarella cheese during 50 d of storage at 4°C were determined. Three vats (180kg of milk per vat) of cheese fortified at 0, 1.5, and 3% of NDM were made using a stirred-curd, no-brine method. The ratio of casein to fat was held constant by adjusting the fat content of the milk. The cheese making was replicated on 3 different d using a 3 × 3 Latin square design. Total N content in whey and stretching water increased as NDM fortification increased. The calcium content of the cheese increased as NDM fortification increased, and cheese moisture tended to decrease as fortification increased. Nitrogen that was soluble in 12% TCA and acetate buffer at pH 4.6 increased during storage for all cheeses. Fortification with 3% NDM decreased the rate of increase in both types of soluble N during refrigerated storage. Cheese made with 3% NDM fortification had a tendency toward firmer texture of unmelted cheese and higher apparent viscosity of melted cheese. Meltability and free oil formation were not affected by the fortification. As NDM fortification increased, cheese tended to show a slight increase in browning.
Comparison of survival among eligible patients not enrolled versus enrolled in the Collaborative Ocular Melanoma Study (COMS) randomized trial of pre-enucleation radiation of large choroidal melanoma.

Purpose: To compare survival between patients enrolled in the Collaborative Ocular Melanoma Study (COMS) randomized trial of pre-enucleation radiation therapy (PERT) for large choroidal melanoma and eligible patients who did not enroll. Methods: COMS clinical center personnel prospectively reported to the COMS Coordinating Center all patients with choroidal melanoma examined between November 1986 and December 1994. Deaths of enrolled patients were reported prospectively by clinical center personnel. In a COMS ancillary study, we retrospectively searched medical records of participating clinical centers, the Social Security Death Index, and the National Death Index to determine vital status of eligible patients not enrolled. Cox proportional hazards analysis was used to compare survival within 10 years of baseline reporting and before July 31, 2000, of enrolled patients versus eligible patients not enrolled. Results: Clinical centers that received local institutional review board approval to participate in...
Gender, sexual orientation, and romantic partner influence on body image An examination of heterosexual and lesbian women and their partners

Although social influences are implicated in the development of body image, research has yet to address the roles of women’s sexual orientation and romantic partners’ weight statuses in predicting women’s body image. This study examines both heterosexual (n = 104) and lesbian (n = 144) women and their partners’ body mass indexes and body image using actor–partner interdependence models. The results indicated that lesbian women preferred larger body ideals than heterosexual women and that women’s ideal body preferences were not related to their partners’ weight status. However, both lesbian and heterosexual women’s perceptions of their actual body size were related to their partners’ weight status such that heavier women who had relatively thin partners were most at risk of perceiving themselves as overweight.
A simple autoradiographic method for investigating long range chromosome substructure: size and number of DNA molecules in isolated nucleoids of Escherichia coli.

Abstract A method is described for gently dissociating large DNA-protein complexes and for visualizing and quantitating the substructures by autoradiography. Using this technique, it is shown that nucleoids isolated from exponentially growing Escherichia coli (mean generation time = 35 min) contain on average 2.8 genome equivalents of DNA and that this nucleoid can be dissociated by deproteinization into two substructures having on average 1.4 genome equivalents. This result is correlated with previous sedimentation studies on the unfolded nucleoid DNA to explain prior inconsistencies. Scanning electron microscopy studies demonstrate that the shape and size of the isolated nucleoid is consistent with the proposed subunit structure of the in vivo nucleoid.
Comparison of taxon calibrations, modern analogue techniques, and forest-stand simulation models for the quantitative reconstruction of past vegetation

We compared results of three quantitative methods for reconstructing past vegetation, including (1) calibrations of per cent dominance vs. per cent pollen for individual tree taxa; (2) coefficients of dissimilarity between fossil and modern pollen assemblages; and (3) simulation modelling of long-term forest succession. For calibration, we used 1684 modern pollen samples and 1742 forest-inventory summaries from eastern North America. We applied the calibrations at 1 000-year intervals to the 19000-year pollen record from Anderson Pond, Tennessee. Dominance values reconstructed using taxon calibrations typically paralleled the changes in percentages of arboreal pollen. Dissimilarity values between fossil and modern pollen assemblages were lowest from 19 000 yr BP to 15 000 yr BP and from 9 000 yr BP to the present, indicating good modern analogues for both full-glacial and Holocene time periods. During times of good analogue, forest composition estimated from forest inventories at the locations of best pollen analogues was similar to that reconstructed using taxon calibrations. Relatively poor modern analogues exist for late glacial and early Holocene pollen spectra from Anderson Pond. During times of poor analogues, forest composition reconstructed from taxon calibrations differed from that derived from analogue methods. FORET-model simulations of forest-stand biomass differed markedly from palaeovegetation estimates made from the other two methods. This is primarily because the FORET model is scaled to forest succession on 1/12-ha forest plots rather than forest dynamics integrated over a broad landscape mosaic. Because they are based upon fundamental relationships of pollen production and dispersal, taxon calibrations provide the best available means for reconstructing forest history both during times of good and of poor analogues.
An analysis of broad-spectrum pulse amplification from mixed Nd:glass amplifiers

We present results in a comprehensive analysis of gain shaping from Nd:glass amplifiers in an effort to generate near 100 fs pulses in chirped pulse amplification. We discuss relative gain balance between the two media.