cssi/SciSciGPT-SciSciNet huggingface dataset:
The Mount Edgecumbe tephra deposits, a marker horizon in southeastern Alaska near the Pleistocene-Holocene boundary

Late Pleistocene tephra deposits found from Sitka to Juneau and Lituya Bay are assigned to a source at the Mount Edgecumbe volcanic field, based on similarity of glass compositions to nearvent deposits and on thinning away from Kruzof Island. The sequence of near-vent layers is basaltic andesite and andesite at the base, rhyolite, and mixed dacite and rhyolite on top. The only breaks in the tephra sequence are two 1-mm-thick silt partings in a lake-sediment core, indicating a depositional interval from basaltic andesite to dacite of no more than about a millennium. Tephra deposits at sites >30 km from the vent are solely dacite and rhyolite and are 10,600 to 11,400 14C yr old based on interpretation of 18 radiocarbon ages, including 5 by accelerator mass spectrometry (AMS). Basaltic andesite and andesite deposits nearer the vent are as much as 12,000 yr old. Discrepancy among radiocarbon ages of upland tephra deposits provisionally correlated as the same grainfall is resolvable within ±2 σ of analytical uncertainty. Comparison of bulk and AMS ages in one sediment core indicates a systematic bias of +600 to +1100 yr for the bulk ages; correlation of tephra deposits among upland and lacustrine sites implies an additional discrepancy of 200–400 yr between upland (relatively too young) and lacustrine ages. In any case, the Mount Edgecumbe tephra deposits are a widespread, latest Pleistocene stratigraphic marker that serves to emphasize the uncertainty in dating biogenic material from southeastern Alaska.
Drug-drug interactions and acute kidney injury: caveat prescriptor.

Nephrologists are by necessity practicing pharmacologists. The kidneys play a central role in the metabolism and excretion of many drugs and are uniquely susceptible to toxic and ischemic injury from a number of drugs.1 Nephrologists therefore must be aware of how kidney disease alters drug disposition and clearance and how drugs may cause kidney toxicity. The knowledge domain is complex: estimated glomerular filtration rate dictates drug dosing for many drugs in use that are excreted primarily by glomerular filtration. In addition, chronic kidney disease (CKD) and acute kidney injury (AKI) influence drug dosing for drugs that are not excreted by the kidney due to alterations in hepatic drug metabolism and transport.2 Nephrotoxicity can arise from a variety of mechanisms, including tubular injury, intratubular obstruction/crystallization, glomerular injury, and vascular injury.3 KDIGO (Kidney Disease: Improving Global Outcomes) conducted a conference titled “Drug Prescribing in Kidney Disease: Initiative for Improved Dosing” to address the complex issues related to drug dosing in patients with decreased kidney function and shed light on this important patient safety issue.4 In an article recently published in the Journal of the American Medical Association, Gandhi et al5 have brought needed attention to under-recognized drug-drug interactions that increase the risk of AKI.5 As the number of prescribed medications increases (poly-pharmacy), so does the risk of drug-drug interactions.6 Nearly one-third of adults 60 years or older take 5–9 medications daily, and 12% take 10 or more. Within the field of nephrology, dialysis patients may take more than 19 pills per day,7 and transplant recipients typically require 5–6 medications or more per day.8 As a result, knowledge of clinically relevant drug-drug interactions and implementation of strategies to avoid them are important public health and safety challenges.
COMPUTATION OF THE HEATS OF FORMATION OF CYCLOPROPANE AND CYCLOBUTANE DERIVATIVES USING DENSITY FUNCTIONAL THEORY METHODS

Abstract A systematic study of the heats of formation (HOF) for cyclopropane and cyclobutane derivatives was performed using Density Functional Theory (DFT) methods. Five groups of computational methods were employed: hybrid, exchange functionals only, Becke's 88, Xα, and Slater's exchange functional based DFT methods. The isodesmic approach to compute the energy of a bond separation reaction was applied. In all calculations, the 6-31G(d,p) Gaussian-type basis set was used. The computed HOFs were compared with experimental data and the DFT methods most appropriate for these types of calculations are proposed.
Hepatitis C in Transplant Recipients of Solid Organs, Other than Liver

Hepatitis C virus (HCV) infection is prevalent in candidates for, and recipients of, solid organ transplants. HCV infection can lead to diminished patient and allograft survival in the long-term in recipients of kidney transplants. Outcomes in recipients of other solid organ transplants (lung, heart, small bowel, pancreas, pancreas-kidney) are not well established. Large, well-designed, prospective studies are needed to answer these questions. Interferon therapy for HCV before transplantation can lead to improved outcomes. Therefore, transplant candidates should be considered for and offered interferon therapy before embarking on organ transplantation. Posttransplant interferon therapy can be complicated by acute allograft rejection and is not recommended, except with advanced liver disease.
Immunohistochemical localization of PDE10A in the rat brain.

PDE10A is a newly identified cAMP/cGMP phosphodiesterase for which mRNA is highly expressed in the mammalian striatum. In the present study, PDE10A protein and mRNA expression throughout the rat brain were determined, using a monoclonal antibody (24F3.F11) for Western blot and immunohistochemical analyses and an antisense riboprobe for in situ hybridization. High levels of mRNA are observed in most of the neuronal cell bodies of striatal complex (caudate n, n. accumbens and olfactory tubercle), indicating that PDE10A is expressed by the striatal medium spiny neurons. PDE10A-like immunoreactivity is dense throughout the striatal neuropil, as well as in the internal capsule, globus pallidus, and substantia nigra. These latter regions lack significant expression of PDE10A mRNA. Thus, PDE10A is transported throughout the dendritic tree and down the axons to the terminals of the medium spiny neurons. These data suggest a role for PDE10A in regulating activity within both the striatonigral and striatopallidal pathways. In addition, PDE10A immunoreactivity and mRNA are found at lower levels in the hippocampal pyramidal cell layer, dentate granule cell layer and throughout the cortex and cerebellar granule cell layer. Immunoreactivity is detected only in cell bodies in these latter regions. This more restricted subcellular localization of PDE10A outside the striatum suggests a second, distinct function for the enzyme in these regions.
Kinetic model of fluoride metabolism in the rabbit

Abstract Sodium fluoride, in small doses, was given to rabbits intravenously or by stomach tube, and the appearance of fluoride in the blood and urine was then monitored frequently over the next 10 hours. Compartmental analysis of the data yielded a kinetic model of fluoride metabolism comprising gut, extracellular fluid (including plasma), urine, short term nonexchangeable bone, exchangeable bone, and intracellular fluid. Fractional transfer rates and the content curve were obtained for each compartment. The results indicated that under steady state conditions approximately 15% of fluoride ingested in food and water was absorbed by the rabbit. The absorbed fluoride entered the extracellular fluid pool, where portions exchanged with fluoride in the tissues and bone. An equivalent amount, i.e., 15% of the intake, was then excreted in the urine. It is interesting to note that in this species a store of fluoride was required in the gut to sustain the steady state. Fecal excretion of fluoride was equivalent to 85% of that ingested. Rate constants calculated for the various transfers indicated that removal of fluoride from the extracellular pool into the nonexchangeable bone compartment was approximately three times more rapid than was removal by excretion into urine. Results of a study with a tracer dose of fluoride, 3 pg of F, gave results in good agreement with those predicted by the model, which was derived from experiments utilizing doses of about 1.5 mg. This suggested that the response is linear over a large dose range.
Optimal and sublogarithmic time randomized parallel sorting algorithms

This paper assumes a parallel RAM (random access machine) model which allows both concurrent reads and concurrent writes of a global memory.The main result is an optimal randomized parallel algorithm for INTEGER_SORT (i.e., for sorting n integers in the range $[1,n]$). This algorithm costs only logarithmic time and is the first known that is optimal: the product of its time and processor bounds is upper bounded by a linear function of the input size. Also given is a deterministic sublogarithmic time algorithm for prefix sum. In addition this paper presents a sublogarithmic time algorithm for obtaining a random permutation of n elements in parallel. And finally, sublogarithmic time algorithms for GENERAL_SORT and INTEGER_SORT are presented. Our sub-logarithmic GENERAL_SORT algorithm is also optimal.
RELATIONSHIP BETWEEN INCENTIVE AND EXPECTATIONS OF SUCCESS

Some theorists have assumed that there is a negative relationship between the probability of success and the incentive of success. This paper presents arguments and some research which suggests that, depending upon conditions, the relationship may be either positive or negative. Possible effects of this finding upon the Atkinson model were discussed.
Ependymal cells of the filum terminale in fish (Poecilia sphenops) adapted to freshwater and saltwater: electron microscopic study.

The ependymal lining of the central canal of the filum terminale and spinal cord in the vicinity of the caudal neurosecretory system in P. sphenops was examined in this study. Two general cell types based on shape and location were observed in the ependymal lining: cuboidal ependyma located in dorsal aspects of the filum terminal and columnar to pseudostratified ependymal cells found in ventrolateral and ventral aspects of the filum terminale. Comparison of the ependymal lining was made in animals adapted to saltwater and freshwater. In animals adapted to saltwater there was an increase in the basal infoldings of the cell membrane of the dorsal cuboidal ependyma. Infolding of the basal cell membrane is a phenomenon shared by cells known to participate in transport of electrolytes. Since a possible functional relationship between the ependyma of the third ventricle and median eminence has been shown, in future studies on the osmoregulatory function of the caudal neurosecretory system the ependymal lining of the central canal in this region should be considered.
Permeability of Thermally Damaged Skin: I. Immediate Influences of 60°C Scalding on Hairless Mouse Skin

Freshly sacrificed hairless mice were burned dorsally by direct contact with 60 °C water for periods ranging from 15 seconds to 8 min. Wounds ranging in degree from superficial epidermis damage to injury penetrating well into subcutaneous musculature were inflicted. Burned skin sections and reference abdominal skin sections were excised, placed in diffusion cells and investigated with regards to their permeabilities to water, methanol, ethanol, n-butanol and n-octanol. The data were couched in terms of ratios of permeability coefficients of burned skin to normal skin (scalding coefficients) for the same animal. Scalding increased permeability of skin to all compounds studied but the effects leveled out by 60 seconds. Protracted scalding was without great effect despite progressively increased depth of damage to the tissue as noted in histological sections. The degree of lost barrier competency attributable to 60°C scalding was not marked for any compound but was definitely different for different alkanols. An approximately 3-fold permeability increase was noted with n-butanol, the most affected compound. The data demonstrate that near instantaneous alterations in permeability of skin accompany scalding, that decreased barrier competency does not correlate with the severity of a burn as measured in depth of the burn, and that thermal alteration of permeabilities is dependent on the physicochemical characteristics of the permeants.
Changing Child Neurology Training Evolution or Revolution

Child neurology training must change as our understanding of the diseases of the developing nervous system increases. A proposed child neurology training path leading to certification in child neurology would eliminate all but 3 months of adult neurology training; however gaining approval for a new Accreditation Council for Graduate Medical Education (ACGME) training program would be an arduous task. I review why this change would add significant administrative and financial burdens and how this change in training could negatively affect the education of child neurology residents. I believe that modifications of the current training requirements already underway could achieve the same aims with fewer losses.
Nr4a1-eGFP Is a Marker of Striosome-Matrix Architecture, Development and Activity in the Extended Striatum

Transgenic mice expressing eGFP under population specific promoters are widely used in neuroscience to identify specific subsets of neurons in situ and as sensors of neuronal activity in vivo. Mice expressing eGFP from a bacterial artificial chromosome under the Nr4a1 promoter have high expression within the basal ganglia, particularly within the striosome compartments and striatal-like regions of the extended amygdala (bed nucleus of the stria terminalis, striatal fundus, central amygdaloid nucleus and intercalated cells). Grossly, eGFP expression is inverse to the matrix marker calbindin 28K and overlaps with mu-opioid receptor immunoreactivity in the striatum. This pattern of expression is similar to Drd1, but not Drd2, dopamine receptor driven eGFP expression in structures targeted by medium spiny neuron afferents. Striosomal expression is strong developmentally where Nr4a1-eGFP expression overlaps with Drd1, TrkB, tyrosine hydroxylase and phospho-ERK, but not phospho-CREB, immunoreactivity in “dopamine islands”. Exposure of adolescent mice to methylphenidate resulted in an increase in eGFP in both compartments in the dorsolateral striatum but eGFP expression remained brighter in the striosomes. To address the role of activity in Nr4a1-eGFP expression, primary striatal cultures were prepared from neonatal mice and treated with forskolin, BDNF, SKF-83822 or high extracellular potassium and eGFP was measured fluorometrically in lysates. eGFP was induced in both neurons and contaminating glia in response to forskolin but SKF-83822, brain derived neurotrophic factor and depolarization increased eGFP in neuronal-like cells selectively. High levels of eGFP were primarily associated with Drd1+ neurons in vitro detected by immunofluorescence; however ∼15% of the brightly expressing cells contained punctate met-enkephalin immunoreactivity. The Nr4a1-GFP mouse strain will be a useful model for examining the connectivity, physiology, activity and development of the striosome system.
Change in Job Values During the Transition to Adulthood

This panel study of young people in the United States addresses a set of interrelated questions on how job values change during the transition to adulthood, including whether the gender differences in job values apparent in adolescence persist across the transition to adulthood, and whether young men's and women's job values change in similar ways. The findings indicate that there is a good deal of instability in job values during this stage of the life course, as young people make the transition from student to adult worker. Gender differences in job values narrow in the process, though do not disappear. For both males and females, job values change in response to the attainment of valued rewards, and not in response to their family roles.
Stingers, the Torg Ratio, and the Cervical Spine

We prospectively determined the risk of initial stinger experience in a group of college football players while considering the presence of cervical canal stenosis and each player's position, playing time, and body type. Prospective analysis revealed a 7.7% incidence of initial stinger experience. The average Torg ratio for all players was 0.924 +/- 0.122, with the seventh cervical level being the narrowest. Initial stinger experience depended on position played and body type. The Torg ratio did not influence initial stinger occurrence. Players who experienced multiple stingers, however, had significantly smaller Torg ratios than players experiencing only one stinger (0.75 versus 0.87). A Torg ratio of 0.70 may be a more statistically and clinically appropriate threshold for determining significant cervical stenosis and advising collegiate athletes of their risk of experiencing recurrent stingers.
Matrix elements of the Coulomb Green function between Slater orbitals

Analytic expressions are given for integrals of the Coulomb Green function with Slater type atomic orbitals. The results involve hypergeometric functions.
A primer on standards setting as it applies to surgical education and credentialing

Surgical technological advances in the past three decades have led to dramatic reductions in the morbidity associated with abdominal procedures and permanently altered the surgical practice landscape. Significant changes continue apace including surgical robotics, natural orifice-based surgery, and single-incision approaches. These disruptive technologies have on occasion been injurious to patients, and high-stakes assessment before adoption of new technologies would be reasonable. We reviewed the drivers for well-established psychometric techniques available for the standards-setting process. We present a series of examples that are relevant in the surgical domain including standards setting for knowledge and skills assessments. Defensible standards for knowledge and procedural skills will likely become part of surgical clinical practice. Understanding the methodology for determining standards should position the surgical community to assist in the process and lead within their clinical settings as standards are considered that may affect patient safety and physician credentialing.
High temperature oxidation of fuel cladding candidate materials in steam–hydrogen environments

Abstract Alternative fuel cladding materials to Zr alloys are being investigated for enhanced accident tolerance, which specifically involves oxidation resistance to steam or steam–H2 environments at ⩾1200 °C for short times. Based on a comparison of a range of commercial and model alloys, conventional austenitic steels do not have sufficient oxidation resistance with only ∼18Cr–10Ni. Higher alloyed type 310 stainless steel is protective but Ni is not a desirable alloy addition for this application. Results at 1350 °C indicated that FeCrAl alloys and CVD SiC remain oxidation resistant in steam. At 1200 °C, high (⩾25% Cr) ferritic alloys appear to be good candidates for this application. Higher pressures (up to 20.7 bar) and H2 additions appeared to have a limited effect on the oxidation behavior of the most oxidation resistant alloys, but higher pressures accelerated the maximum metal loss for less oxidation resistant steels and less metal loss was observed for type 317 L tubing in a H2–50%H2O environment at 10.3 bar compared to 100% H2O.
Impact of uncertainty, social support, and prenatal coping on the psychological well-being of high-risk pregnant women.

BACKGROUND: The effects of uncertainty and social support on the psychological well-being of high-risk pregnant women may be influenced by their prenatal coping strategies. OBJECTIVE: The purpose of this study was to investigate whether prenatal coping strategies (preparation for motherhood, avoidance, positive interpretation of events, and prayer) mediate the effects of uncertainty and social support on the psychological well-being of high-risk pregnant women. METHODS: A cross-sectional, descriptive, correlational design was used. The convenience sample consisted of 105 high-risk pregnant women 18-34 years of age and at 24-36 weeks gestation. The main measures were Mishel Uncertainty in Illness Scale, Medical Outcomes Study Social Support Survey, Prenatal Coping Inventory, and Psychological General Well-Being Index. Data analysis included descriptive statistics, correlational techniques, and path analyses. RESULTS: The women reported low levels of uncertainty, moderate levels of distress, and high levels of social support. Prayer was the most frequently used prenatal coping strategy, whereas avoidance was used least often. Women who reported higher levels of uncertainty also reported less social support (r = -.45, p < .01), less psychological well-being (r = -.48, p < .01), less positive interpretation (r = -.30, p < .01), and more use of avoidance (r = .43, p < .01). The modified path analysis showed good fit with the data. Avoidance significantly mediated the effects of uncertainty on psychological well-being (z = -2.74, p < .01). Social support had a significant direct effect on preparation for motherhood (beta = .43, z = 3.94, p < .001). DISCUSSION: Avoidance mediated the effect of uncertainty on psychological well-being for the high-risk pregnant women in this sample. The results of the study may help perinatal nurses to better understand how high-risk pregnancy affects these women.
Experimental progress in quantum-dot cellular automata

An overview is given of the quantum-dot cellular automata (QCA) architecture, along with a summary of experimental demonstrations of QCA devices. QCA is a transistorless computation paradigm that can provide a solution to such challenging issues as device and power density. The basic building blocks of the QCA architecture, such logic gates and clocked cells have been demonstrated. The experiments to date have used QCA cells composed of metallic islands, and operate only at low temperatures. For QCA to be practical, the operating temperature must be raised, and molecular implementations are being investigated that should yield room temperature operation.
Zinc′s Exclusive Tetrahedral Coordination Governed by Its Electronic Structure

Zinc is a critical component of more than 300 proteins including farnesyltransferase, matrix metalloproteinases and endostatin that are involved in the front-line cancer research, and a host of proteins termed zinc fingers that mediate protein-protein and protein-nucleic acid interactions. Despite the growing appreciation of zinc in modern biology, the knowledge of zinc′s coordination nature in proteins remains controversial. It is typically assumed that Zn2+ coordinates to four to six ligands, which led to intensive debates about whether the catalysis of some zinc proteins is regulated by zinc′s four- or five-coordinate complex. Here we report the inherent uncertainty, due to the experimental resolution, in classifying zinc′s five- and six-coordinate complexes in protein crystal structures, and put forward a tetrahedral coordination concept that Zn2+ coordinates to only four ligands mainly because of its electronic structure that accommodates four pairs of electrons in its vacant 4s4p 3 orbitals. Experimental observations of five- and six-coordinate complexes were due to one or two pairs of ambidentate coordinates that exchanged over time and were averaged as bidentate coordinates. This concept advances understanding of zinc′s coordination nature in proteins and the means to study zinc proteins to unlock the secrets of Zn2+ in human biology. In particular, according to this concept, it is questionable to study zinc′s coordination in proteins with Co2+ as a surrogate of Zn2+ for spectroscopic measurements, since the former is a d7 unclosed shell divalent cation whereas the latter is a d10 closed shell divalent cation.
A modified suture technique produces consistent cerebral infarction in rats.

Abstract Intraluminal occlusion of the middle cerebral artery (MCA) is used extensively in cerebral ischemia research. We tested a modified nylon suture in a rat model of middle cerebral artery occlusion (MCAO) under two anesthesia regimens. Sprague–Dawley rats were divided into six groups (Group 1, Poly- l -lysine-coated suture under ketamine/xylazine anesthesia; Group 2, modified suture under ketamine/xylazine anesthesia; Group 3, Poly- l -lysine-coated suture under ketamine/xylazine anesthesia with mechanical ventilation; Group 4, modified suture under ketamine/xylazine anesthesia with mechanical ventilation; Group 5, Poly- l -lysine-coated suture under isoflurane anesthesia; Group 6, modified suture under isoflurane anesthesia) and subjected to 2-hour MCAO. Regional cerebral blood flow (rCBF) was monitored by Laser-Doppler flowmetry. Neurological evaluation and ischemic lesion (TTC stain) were assessed at 24 hours of reperfusion. The total ischemic lesion (sum of areas with lacking and intermediate TTC staining) was similar among all six groups. Compared with a Poly- l -lysine-coated suture technique, the modified suture technique produced a lower rCBF, larger infarct size, smaller variance of infarct size, and greater neurological deficit. In addition, isoflurane significantly reduced infarct size. We conclude that the use of this modified suture technique with ketamine/xylazine anesthesia and mechanical ventilation produces a more consistent change in cerebral ischemic damage following MCAO in rats.
The kinome of Phytophthora infestans reveals oomycete-specific innovations and links to other taxonomic groups

Oomycetes are a large group of economically and ecologically important species. Its most notorious member is Phytophthora infestans, the cause of the devastating potato late blight disease. The life cycle of P. infestans involves hyphae which differentiate into spores used for dispersal and host infection. Protein phosphorylation likely plays crucial roles in these stages, and to help understand this we present here a genome-wide analysis of the protein kinases of P. infestans and several relatives. The study also provides new insight into kinase evolution since oomycetes are taxonomically distant from organisms with well-characterized kinomes. Bioinformatic searches of the genomes of P. infestans, P. ramorum, and P. sojae reveal they have similar kinomes, which for P. infestans contains 354 eukaryotic protein kinases (ePKs) and 18 atypical kinases (aPKs), equaling 2% of total genes. After refining gene models, most were classifiable into families seen in other eukaryotes. Some ePK families are nevertheless unusual, especially the tyrosine kinase-like (TKL) group which includes large oomycete-specific subfamilies. Also identified were two tyrosine kinases, which are rare in non-metazoans. Several ePKs bear accessory domains not identified previously on kinases, such as cyclin-dependent kinases with integral cyclin domains. Most ePKs lack accessory domains, implying that many are regulated transcriptionally. This was confirmed by mRNA expression-profiling studies that showed that two-thirds vary significantly between hyphae, sporangia, and zoospores. Comparisons to neighboring taxa (apicomplexans, ciliates, diatoms) revealed both clade-specific and conserved features, and multiple connections to plant kinases were observed. The kinome of Hyaloperonospora arabidopsidis, an oomycete with a simpler life cycle than P. infestans, was found to be one-third smaller. Some differences may be attributable to gene clustering, which facilitates subfamily expansion (or loss) through unequal crossing-over. The large sizes of the Phytophthora kinomes imply that phosphorylation plays major roles in their life cycles. Their kinomes also include many novel ePKs, some specific to oomycetes or shared with neighboring groups. Little experimentation to date has addressed the biological functions of oomycete kinases, but this should be stimulated by the structural, evolutionary, and expression data presented here. This may lead to targets for disease control.
An evaluation of shape indices as palaeoenvironmental indicators using quartzite and metavolcanic clasts in Upper Cretaceous to Palaeogene beach, river and submarine fan conglomerates

The feasibility of using quantitative shape measurements to discriminate between clast populations from different depositional settings was evaluated using samples from 11 fluvial, six submarine fan and four beach conglomerates from south-west California; these origins had been established previously by facies analysis. Quartzite and metavolcanic clasts were characterized by the following indices: modified Wentworth roundness (Rw), maximum projection sphericity (δp), oblate-prolate index (OPI) and long (L), intermediate (I) and short (S) axial ratios. These indices were compared with those documented previously for modern gravels. The results show that certain indices are useful palaeoenvironmental indicators, despite inherited differences in shape due to texture, provided that multiple sites are sampled and a statistical approach is used. Statistically, the most effective shape indices are δp and S/L which give good results with the Zingg classification (I/L vs. S/I); better results are also obtained using quartzite clasts. The OPI is useful for discriminating between beach and river conglomerates, which consist largely of oblate and prolate clasts, respectively. The relative abundance of blade-shaped clasts is a useful index of sediment maturity, being greatest for river clast samples and smallest for submarine fan clast samples. The latter are dominated by spherical particles. No correlation between palaeoenvironment and Rw is observed, hence the abundance of disc-shaped clasts in the beach conglomerates studied is attributed to selective transport in suspension and sediment by passing during fluvial transport prior to deposition in the surf zone. Selective transport of rollers (spheres and rods) by traction in a shallow marine setting, prior to redeposition by mass transport, may be responsible for the dominance of spherical particles in submarine fan conglomerates.
Soil-geomorphology relations in mountains of Oregon, U.S.A.

Abstract The development and distribution of soils in the Coast Range and Klamath Mountains are related to geomorphic surfaces and slope gradients. Soils over basalt, studied in the Coast Range, were formed in transported materials and include examples of more than a half dozen great groups of the Alfisol, Inceptisol, Mollisol, and Ultisol orders. Distribution patterns of the soils can be related to active slopes, metastable slopes, pediments, ridge tops, flood plains, and alluvial fans. Variables among the factors of soil formation in the Coast Range are chiefly geomorphic surfaces and parent materials. Soils of a lithosequence of pyroclastics, granite and schist in the Klamath Mountains include examples of great groups in the Entisol, Inceptisol, and Mollisol orders. All soils from pyroclastics have argillic horizons, those from granite lack argillic horizons, and those from schist lack argillic horizons except on relatively stable surfaces. Average thicknesses of soils over saprolite range from 76 cm over granite and schist to 150 cm over pyroclastics. Lithologic discontinuities are common in both mountain areas. Field techniques for identification, described briefly, include stone lines, irregular distribution of rock fragments with depth, thicknesses of weathering rinds on rock fragments, and the lateral extensions of soil horizons.
Thermodynamic properties of two alternative refrigerants : 1,1-dichloro-2,2,2-trifluoroethane (R123) and 1,1,1,2-tetrafluoroethane (R134a)

Abstract This paper describes two different sets of measurements of the properties of two proposed alternative refrigerants, 1,1,1,2-tetrafluoroethane (R134a) 1 and 1,1-dichloro-2,2,2-trifluoroethane (R123) 1 . The first are vapor—liquid equilibrium measurements made in a simple variable-volume sapphire cell. The vapor pressures and saturation liquid densities were determined for both materials, between 268 K and the critical temperature for R134a and between 303 K and 373 K for R123. The saturation vapor density was also determined for R134a from 298 K to the critical point, where the critical conditions were measured. The second set of measurements were made with a vibrating tube densimeter from the saturation pressure to 5500 kPa for R134a and to 3500 kPa for R123 in the temperature range 278 K–368 K. These data are then compared with other determinations of similar properties.
The exanthem of dengue fever: Clinical features of two US tourists traveling abroad.

Background Dengue fever is the most common identifiable cause of acute febrile illness among travelers returning from South America, South Central Asia, Southeast Asia, and the Caribbean. Although the characteristic exanthem of dengue fever occurs in up to 50% of patients, few descriptions of it are found in the dermatology literature, and discussions of how to distinguish the dengue exanthem from other infectious disease entities are rare. Chikungunya fever is an emerging infectious disease now seen in returning US tourists and should be considered in the differential diagnosis of dengue fever in the appropriate patient. Objective The purpose of our study was to report two cases of dengue fever among returning US tourists, provide a review of dengue fever, offer an extensive differential diagnosis of dengue fever, and raise awareness among dermatologists of chikungunya fever. Methods This study includes clinical findings of two returning travelers, one who traveled to Mexico and the other to Thailand, complemented by a discussion of both dengue fever and its differential diagnosis. Limitations Limited to 2 case reports. Conclusion Dengue fever should be considered in the differential diagnosis of fever and rash in the returning traveler. Dermatologists should be aware of the distinctive exanthem of dengue fever. Recognition of the dengue fever rash permits a rapid and early diagnosis, which is critical, as dengue fever can progress to life-threatening dengue hemorrhagic fever or dengue shock syndrome.
Surface free energy as the potential in oligomeric equilibria: Prediction of hemoglobin disaggregation constant

Abstract The disaggregation of hemoglobin tetramers into dimers as a function of pH has been measured osmotically, and the equilibrium constant calculated. The equilibrium constant varies with the pH, and at low degrees of charging, its logarithm is a linear function of the surface charge density of the molecule. These properties were predicted from a model that evaluates the free energy change of such reactions in terms of the surface area and surface charge density. The surface free energy model of oligomer association appears to be useful in accounting for the opening and closing of oligomeric channel structures in membranes.
The effect of carotid artery ligation on aqueous humor formation in the rhesus monkey (Macaca mulatta).

Abstract Ligation of one common carotid artery in the rhesus monkey ( Macaca mulatta ) resulted in an immediate decrease in aqueous humor formation rate in the ipsilateral eye. Over a period of four weeks, this affect became less marked. The findings of a decrease in aqueous humor formation indicates its dependence on plasma flow of the ciliary body.
Some aspects of substrate specificity in biological demethylation at C4 of steroids

Abstract In order to ascertain some of the structural requirements for substrate activity in the oxidative demethylation at C4 of steroids by rat liver enzymes, several steroids have been synthesized, labeled with tritium, and incubated with rat liver enzyme preparations. These include 4α-formyl-4β-methylcholestan-3β-ol ( 4 ), 4-methylcholest-3-ene ( 14 ), 3β,4β-epoxy-4α-methylcholestane ( 20 ), 3α,4α-epoxy-4β-methylcholestane ( 18 ), 4α-ethyl-4β-methylcholestan-3β-ol ( 21 ), and 4β-ethyl-4α-methylcholestan-3β-ol ( 22 ). Enzymic incubation demethylates 4 with an efficiency consistent with its being an intermediate in the biological demethylation of 4,4-dimethyl sterols, but all of the other substrates are recovered unchanged.
The Search for Employment: Motivation to Engage in a Coping Behavior1

The search for employment was examined as coping through engagement in motivated behavior. A model predicting social networking and employer contact behavior was tested with a sample of persons anticipating college graduation. Proposed relations among behavioral antecedents were primarily drawn from Ajzen's (1985) theory of planned behavior, with the addition of cognitively appraised challenge. Structural equations analysis revealed general support for hypothesized relations among attitude, norms, perceived behavioral control, intentions, and behaviors. Cognitively appraised challenge partially mediated the effects of perceived behavioral control on job search intentions. Significant variance in job search attitude was attributed to a valence by outcome expectancy interaction. Findings may be useful in promoting job search efforts, as well as furthering theoretical delineation of the search process.
Reflectivity, Ice Scattering, and Lightning Characteristics of Hurricane Eyewalls and Rainbands. Part II: Intercomparison of Observations

Abstract Part I of this two-part paper treats Tropical Rainfall Measuring Mission (TRMM) radar, passive microwave, and lightning observations in hurricanes individually. This paper (Part II) examines relationships between these parameters (and implications of the relationships). Quantitative relationships between lightning occurrence and 85-GHz brightness temperature, 37-GHz brightness temperature, and radar reflectivity in the mixed phase region are established separately for hurricane eyewall regions, inner rainband regions, and outer rainband regions; other tropical oceanic regions; and tropical continental regions. When any of the brightness temperature or radar parameters are held constant as controls, lightning is more frequent in hurricane outer rainbands than elsewhere over tropical oceans, and more frequent over continents than even in the outer rainbands. Reflectivity profiles associated with specific brightness temperatures are presented, demonstrating a link between high-altitude ice phase pre...
Reading for a Multiple-Choice Test: Headings as Schema Activators

This experiment investigated the effect of headings on memory as a function of the reader's preexisting knowledge about the passage topic. Fifty-five of the 116 college student subjects read a 1,760-word passage on human sexuality with headings present, and the other 61 subjects read the passage with the headings removed. An analysis of the scores on the multiple-choice retention test revealed that the only significant facilitative effect of the headings was in the answering of main-idea retention test questions by subjects with high preexisting knowledge about the topic, as assessed by a pretest, p<.05. Thus, the results suggest that headings facilitate recognition memory by activating schemas and that such an organizational effect of headings is more likely to benefit main-idea information than detail information. Several recent studies have reported facilitative effects of headings on various types of recall performance (e.g., Dee-Lucas & Di Vesta, 1980; Hartley, Kenely, Owen, & Trueman, 1980; Hartley, Morris, & Trueman, 1981; Hartley & Trueman, 1983, 1985; Holley, Dansereau, Evans, Collins, Brooks, & Larson, 1981). These findings have in turn been complemented by results showing a significant positive effect of headings on multiple-choice test performance (Brooks, Dansereau, Spurlin, & Holley, 1983, exp. 1; Wilhite, 1986), suggesting that headings can have a general facilitative effect on memory for expository prose. In their study, Brooks et al. (1983) suggested that headings may facilitate memory by activating schemas relevant to the passage topic, by encouraging the interrelating of concepts in the text, and by providing cues for subsequent retrieval. The present study was designed to investigate to what extent schema activation is in fact involved in any facilitative effect that headings may have on multiple-choi ce test performance following the reading of a passage.
Glycosylation at Asn91 of H1N1 haemagglutinin affects binding to glycan receptors

The glycoprotein HA (haemagglutinin) on the surface of influenza A virus plays a central role in recognition and binding to specific host cell-surface glycan receptors and in fusion of viral membrane to the host nuclear membrane during viral replication. Given the abundance of HA on the viral surface, this protein is also the primary target for host innate and adaptive immune responses. Although addition of glycosylation sites on HA are a part of viral evolution to evade the host immune responses, there are specific glycosylation sites that are conserved during most of the evolution of the virus. In the present study, it was demonstrated that one such conserved glycosylation site at Asn91 in H1N1 HA critically governs the glycan receptor-binding specificity and hence would potentially impinge on the host adaptation of the virus.
A Ras by Any Other Name

Ras proteins are now well recognized for their essential function in transducing extracellular signals that regulate cell growth, survival, and differentiation. Although ras genes were originally identified in the mid-1960s as the transforming elements of the Harvey and Kirsten strains of rat sarcoma viruses, investigation of the biological properties of their protein products did not gain momentum until the early 1980s, when mutated alleles of cellular ras genes were identified as dominant oncogenes in various types of human tumors. The mammalian ras gene family consists of three members: H-ras, K-ras, and N-ras, which are located on different chromosomes. The H-ras and K-ras genes are the cellular counterparts of the viral Harvey and Kirsten genes, respectively, and the N-ras gene is derived from a human neuroblastoma cell line. Are the different ras genes functionally redundant or does each ras gene have a specific role? This review briefly recounts results from biochemical and genetic studies supporting the unanticipated possibility that the answer to both questions may be yes.
Synthetic aperture radar imaging of ocean-bottom topography via tidal-current interactions: Theory and observations

Abstract A numerical model has been developed for the purpose of explaining and quantifying the relationship between the SEASAT synthetic aperture radar (SAR)signatures and the bottom topography of the ocean in the Southern Bight of the North Sea and Nantucket Shoals. The model uses environmental data (wind, current and depth changes)and radar system parameters (frequency, polarization, incidence angle and resolution cell size)as inputs and predicts SAR-observed backscatter changes over topographic changes in the ocean floor. The model results compare favourably with the actual SEASAT SAR-observed backscatter values. The comparisons between the model and the actual data are all within 1·5 dB except for one limiting geometry. The model suggests that for bottom features to be visible on SAR imagery, a moderate to high current velocity (0·4 m/s or greater) and a low to moderate wind (between 1·5 and 7·5 m/s) must be present.
Polarimetric Radar Observations of Hail Formation

Analyses are made of the evolution of selected polarimetric radar data fields during periods immediately preceding the onset of near-surface hail indicators [high reflectivity and low differential reflectivity ( Zdr)] in two nonsupercellular northeastern Colorado hailstorms. The primary data were obtained from the 11-cm-wavelength, dual-polarization Colorado State University (CSU)‐University of Chicago and Illinois State Water Survey radar. In one of the storms, dual-Doppler wind field syntheses were available using additional velocity data collected by the CSU Pawnee S-band radar. In both events, linear depolarization ratio (LDR) values exceeding 225 dB began to appear in the right flank of the 50-dB Z echo core region, within the 08 to 2208C environmental temperature range, approximately 10 minutes prior to the onset of hail at the surface. Scattering calculations suggest that the LDR enhancement may have been caused by an increasing water fraction within the growing hailstones (spongy hail), or the development of a liquid water coat under wet growth conditions. Vertical structure of the Zdr fields was also examined. As hypothesized by Conway and Zrnic ´, it was found that the distinctness of the positive Zdr column associated with supercooled raindrops and incompletely frozen particles above the 08C height varies from storm to storm.
Newcomb's Problem and Prisoners' Dilemma:

The relationship between Newcomb's problem, which involves an apparent paradox of prediction, and Prisoners' Dilemma is explicated. After describing a resolution to Newcomb's problem, due to John A. Ferejohn, that renders the two contradictory principles of choice in Newcomb's problem (dominance and expected utility) consistent, I show Prisoners' Dilemma to be a “symmetricized” version of Newcomb's problem in its payoff structure. The assumption about predictability of choice made for one player in Newcomb's problem, when applied to both players in Prisoners' Dilemma–one considered as a leader and the other as a follower–offers a resolution to this dilemma that, while consistent with the resolution offered by metagame theory, rationalizes the existence of a metagame solution within a probabilistic, rational-choice framework. The relevance of the mutual-predictability assumption to the solution of arms races, and tragedy-of-commons situations generally, is discussed.
Clinical and Diagnostic Evaluation of Low Back Pain

The clinical and diagnostic evaluation of patients with low back pain can be an extremely challenging and frustrating task. Fortunately, most episodes of low back pain are self-limiting and do not require extensive evaluation or treatment. Clinicians must search for “red flags,” which may indicate more serious pathology, during their evaluation. The presence of one of these may trigger a more extensive work-up. Physical examiniation, imaging modalities, including plain radiographs, bone scans, and magnetic resonance imaging, diagnostic injections, and provocative discography, can all be utilized in the evaluation of low back pain. Unfortunately, no one test or any combination of these tests can pinpoint the exact anatomic source of pain in each patient. Therefore, clinicians formulating treatment plans based upon these tests should do so with caution.
TNF signaling inhibition in the CNS: implications for normal brain function and neurodegenerative disease

The role of tumor necrosis factor (TNF) as an immune mediator has long been appreciated but its function in the brain is still unclear. TNF receptor 1 (TNFR1) is expressed in most cell types, and can be activated by binding of either soluble TNF (solTNF) or transmembrane TNF (tmTNF), with a preference for solTNF; whereas TNFR2 is expressed primarily by microglia and endothelial cells and is preferentially activated by tmTNF. Elevation of solTNF is a hallmark of acute and chronic neuroinflammation as well as a number of neurodegenerative conditions including ischemic stroke, Alzheimer's (AD), Parkinson's (PD), amyotrophic lateral sclerosis (ALS), and multiple sclerosis (MS). The presence of this potent inflammatory factor at sites of injury implicates it as a mediator of neuronal damage and disease pathogenesis, making TNF an attractive target for therapeutic development to treat acute and chronic neurodegenerative conditions. However, new and old observations from animal models and clinical trials reviewed here suggest solTNF and tmTNF exert different functions under normal and pathological conditions in the CNS. A potential role for TNF in synaptic scaling and hippocampal neurogenesis demonstrated by recent studies suggest additional in-depth mechanistic studies are warranted to delineate the distinct functions of the two TNF ligands in different parts of the brain prior to large-scale development of anti-TNF therapies in the CNS. If inactivation of TNF-dependent inflammation in the brain is warranted by additional pre-clinical studies, selective targeting of TNFR1-mediated signaling while sparing TNFR2 activation may lessen adverse effects of anti-TNF therapies in the CNS.