cssi/SciSciGPT-SciSciNet huggingface dataset:
The extrasplanchnic origin of blood dihydrotestosterone in elderly men

Abstract The splanchnic extraction and interconversion of testosterone (T) and dihydrotestosterone (DHT) were studied in 5 elderly men undergoing cardiac catheterization using a constant Infusion of [1,2-3H] testosterone and [4-14C] DHT. Metabolic clearance rate (MCR), splanchnic extraction (SE), splanchnic clearance (SC), extrasplanchnic clearance (ESC), transfer constant In blood ([P]BBT-DHT) and transfer constant across the liver ([P]BBT-DHT) were calculated. The MCRT was 675 ± 108 (mean ± SC) L/day and MCRDHT was 409 ± 68 L/day. SET was 45.9 ± 7.0% and SEDHT was 18.5 ± 5.4%. When these values are compared with those recently reported by us for normal men, there is a 1 3 reduction in SET and 1 2 reduction for SEDHT in elderly men. The calculated SCT and ESCT were 355 ± 72 L/day and 320 ± 86 L/day, respectively. SCDHT and ESCDHT were 145 + 48 L/day and 263 ± 77 L/day respectively, suggesting that a major fraction of DHT is metabolized in extrasplanchnic organs. No evidence for a net appearance of DHT by either mass or specific activity analysis in hepatic vein blood was observed indicating that the splanchnic compartment does not contribute DHT into the circulation either by de novp synthesis or via conversion from testosterone. This work indicates that conversion of testosterone to DHT in elderly men occurs entirely in extrasplanchnic tissue.
Relative preference for starch and sugar in rats

When given a choice between fluids containing equal amounts of corn starch or glucose, Fischer rats preferred the fluid containing starch when the fluids contained 0.5%, 1%, 5%, or 20% carbohydrate, but not when the fluids contained 10% carbohydrate. Fischer rats preferred 0.5% sucrose over 0.5% starch on the first day of testing, but then switched to preferring starch. Rats of the CD strain also preferred 0.5% starch over 0.5% sucrose or 0.5% glucose, but showed no reliable preference when offered a choice of 5% starch vs. 5% sucrose or 5% glucose. Most experiments used corn starch, but rats prefer 1% rice, wheat, and tapioca starch over 1% glucose. Rats given only one substance to drink, drank more fluid if the fluid contained 1% starch than if it contained 1% glucose. Preexposing rats to either glucose or starch for 3 days did not influence subsequent preference for starch over glucose. Since the starch and glucose mixtures used in the present work had the same number of calories, preference for starch over glucose must be attributed to the hedonic effects of starch flavor rather than to the postingestive effects of starch.
Temporal changes in the hydrography and chemistry of the Cariaco Trench

The Cariaco Trench has been considered a classic example of a marine anoxic basin for nearly 30 years. Although most workers assume that the chemistry of the basin is at steady-state, detailed data sets collected for hydrographic and nutrient parameters in 1973 and 1982 indicate strong temporal variations on a decadal time scale. Over this 8 year period deep-water temperature increased by 0.06°C, salinity by 0.01%, and hydrogen sulfide by 14 μM. Silica concentrations may also have increased by up to 14 μM. We can explain most of the temporal variability of these parameters in the Cariaco Trench deep waters using a time-dependent box model that includes the effects of vertical eddy diffusion and flux of the chemical species from the sediments. Deep-water temperature and salinity increases are primarily the result of downward diffusion of heat and salt, while geothermal heat flux seems to be responsible for only a small fraction of the observed temperature increase. Hydrogen sulfide profiles can be predicted fairly well by the model if a sediment-water flux of 2.7 × 10−6 μmol cm−2 s−1 (measured using pore waters collected with the Woods Hole Insitu Marine Probe) is used. For hydrogen sulfide, in situ production seems to be much less important than diffusion on sulfide from the pore waters. On the other hand, silica profiles cannot be adequately modeled unless an in situ production term is included.
The Basque Country: the heart of Spain, a part of Spain, or Somewhere Else Altogether

The Basque Country exhibits contradictory symptoms of good health and chronic internal rupture. A flexible and robust economy and a vibrant cultural life are undermined by opposed senses of identity, which make almost any statement about the region deeply contentious. The verifiability—or otherwise—of Basque nationalist and Spanish nationalist readings of Basque history and culture matter less today than the fact that they are held with genuine conviction by big sectors of Basque society. Both traditions have their own legitimacy, but neither has been capable of fully acknowledging or including the other. Paradoxically, Francoism reinforced Basque nationalist identity, and anxieties about the survival of the Basque language stimulated radical Basque nationalism, with enduring consequences. An accommodation might be found in acceptance by both sides that Basque identities are multiple, and through recognition that there are several ways of being Basque, none of which need negate any of the others. The recent Irish settlement offers some pointers, though no rigid templates. Bernardo Atxaga’s declaration that Euskera is not the Basque language, but a Basque language, is an indication that this process of respecting multiple identities is already underway, though the obstacles to a resolution remain formidable. This article is available in Studies in 20th & 21st Century Literature: http://newprairiepress.org/sttcl/vol33/iss2/5 The Basque Country: the heart of Spain, a part of Spain, or Somewhere Else Altogether
Initial-value methods in the theory of Fredholm integral equations: II

It is established that a recently developed initial-value method for solving a family of Fredholm integral equations is equivalent to an initial-value version of a classical method based on solving a set of linear equations. This enables the establishment of the convergence of the numerical method.
Methodical Design Approaches to Radiation Effects Analysis and Mitigation in Flip-Flop Circuits

With transistor dimensions shrinking due to continued scaling, integrated circuits are increasingly susceptible to radiation upset. This paper presents a systematic methodology for evaluating circuit hardness, as well as graph clustering approaches to determine effective node separation to protect against upset due to multiple node charge collection. The methodology is circuit simulation based, making it efficient and usable by circuit designers. Example designs are presented to demonstrate the analysis and clustering for real flip-flop designs. Finally, the methodology is utilized to provide critical node separation for a new hardened flip-flop design that reduces the power and area by 27% and 19.5% respectively.
Defective Activation of the Third Component of Complement in the Sera of Newborn Infants

Summary: The activation of the terminal complement components, C3–9, plays an important role in the host's defense against infection. In the present study, the ability of bacteria to activate the third component of complement (C3) in newborn serum was examined. A variety of bacteria were incubated in test sera at 37°C for 30 min and the percent of available C3 that was activated was measured. Using one strain of Escherchia coli(#3), 32% (mean) of the available C3 was activated in sera from 18 newborns, as compared to 85% in sera from their mothers and 79% in sera from 13 normal adults (P<0.005). In contrast, using another strain of E. coli (N70), the percent of C3 activated in newborn sera (83%) was the same as in sera from their mothers (81%) or in sera from normal adults (73%). The defective activation of C3 in newborn sera by E. coli was not related to the presence of the K1 antigen. Newborn sera were also challenged with other bacterial species and the activation of C3 was deficient when tested with klebsiellae, but not with staphylococci or streptococci. The defect in newborn sera appeared to be due to a deficiency of a serum factor rather than to the presence of an inhibitor. Speculation: The defective activation of C3–9 in newborn sera by some bacteria may be, in part, responsible for the neonate's increased susceptibility to infection.
Isotope effects on the carbon-hydrogen bond orientation of methyl iodide in nematic phase

Abstract Deuterium substitution which results in no change in molecular symmetry is demonstrated to produce negligible change in the orientation parameter (SCD) of methyl iodide dissolved in nematic phase. Previous indirect estimates of quadrupolar coupling constants (QD), which have assumed SCD = SCH, are high in relation to those obtained by a direct method. This discrepancy is attributed to geometric distortion caused by dissolution of the probe molecule in nematic phase and not to the inequality of orientation parameters.
The evolution of primary progressive apraxia of speech

Primary progressive apraxia of speech is a recently described neurodegenerative disorder in which patients present with an isolated apraxia of speech and show focal degeneration of superior premotor cortex. Little is known about how these individuals progress over time, making it difficult to provide prognostic estimates. Thirteen subjects with primary progressive apraxia of speech underwent two serial comprehensive clinical and neuroimaging evaluations 2.4 years apart [median age of onset = 67 years (range: 49‐76), seven females]. All underwent detailed speech and language, neurological and neuropsychological assessments, and magnetic resonance imaging, diffusion tensor imaging and 18 F-fluorodeoxyglucose positron emission tomography at both baseline and follow-up. Rates of change of whole brain, ventricle, and midbrain volumes were calculated using the boundary-shift integral and atlas-based parcellation, and rates of regional grey matter atrophy were assessed using tensor-based morphometry. White matter tract degeneration was assessed on diffusion-tensor imaging at each time-point. Patterns of hypometabolism were assessed at the single subject-level. Neuroimaging findings were compared with a cohort of 20 age, gender, and scan-interval matched healthy controls. All subjects developed extrapyramidal signs. In eight subjects the apraxia of speech remained the predominant feature. In the other five there was a striking progression of symptoms that had evolved into a progressive supranuclear palsy-like syndrome; they showed a combination of severe parkinsonism, near mutism, dysphagia with choking, vertical supranuclear gaze palsy or slowing, balance difficulties with falls and urinary incontinence, and one was wheelchair bound. Rates of whole brain atrophy (1.5% per year; controls = 0.4% per year), ventricular expansion (8.0% per year; controls = 3.3% per year) and midbrain atrophy (1.5% per year; controls = 0.1% per year) were elevated (P4 0.001) in all 13, compared to controls. Increased rates of brain atrophy over time were observed throughout the premotor cortex, as well as prefrontal cortex, motor cortex, basal ganglia and midbrain, while white matter tract degeneration spread into the splenium of the corpus callosum and motor cortex white matter. Hypometabolism progressed over time in almost all subjects. These findings demonstrate that some subjects with primary progressive apraxia of speech will rapidly evolve and develop a devastating progressive supranuclear palsy-like syndrome � 5 years after onset, perhaps related to progressive involvement of neocortex, basal ganglia and midbrain. These findings help improve our understanding of primary progressive apraxia of speech and provide some important prognostic guidelines.
Aerosol behavior in the continuous stirred tank reactor

The basic features of aerosol behavior in the CSTR are examined. Solutions are obtained for the steady state aerosol size distribution during simultaneous coagulation, particle growth by vapor condensation and new particle formation by nucleation. Explicit distributions are shown for the case of a monodisperse feed aerosol.
A micro power sigma-delta A/D converter in 0.35-μM CMOS for low frequency applications

A very low-power single loop second order 12-bit sigma- delta (SigmaDelta) A/D converter in 0.35-mum triple metal, double poly CMOS technology has been designed for low frequency applications. The A/D converter includes a second-order SigmaDelta modulator together with a DSP circuit comprising of a cascade of CIC and FIR digital filters. The design was focused on the minimization of power dissipation of the modulator that operates from a single 2-4 V power supply. A reduction of the power dissipation is obtained through the optimization of modulator coefficients, switched-capacitor (SC) integrators, particularly the optimal design of two-stage fully differential Class AB operational transconductance (OTA) amplifiers, which employ circuits for higher noise rejection and control of common mode levels. Local bootstrapping circuits are used for switches in order to facilitate the appropriate signal switching in low-voltage region of operation. Unit capacitors are created using poly-poly structure available in 0.35-mum CMOS technology and employed in SC circuits. The design was simulated in all process corners for active and passive devices considering a -40degC to +120degC temperature range and plusmn10% supply voltage variation. The modulator achieves a dynamic range of 77 dB at a Nyquist conversion rate of 2.5 kHz with an oversampling ratio of 128. The modulator occupies an active area of 0.9 mm dissipating only 120 muW from 2-V supply. The entire A/D converter occupies a die are of 2.4 2 mm2.
Cell kinetics in mouse lung following administration of carcinogens and butylated hydroxytoluene

A series of experiments is described which was designed to test the hypothesis that, in mouse lung, enhancement of tumor development could occur independently of overall alveolar cell hyperplasia. Male A/J mice were given 1000 mg/kg of urethan or 10 mg/kg of 3-methylcholanthrene (MCA). Alveolar cells were labeled through continuous infusion of [3H]thymidine for 6 weeks after administration of the carcinogen. Urethan produced a significant hyperplasia of the type II alveolar cell population, whereas MCA had no such effect. Five repeated injections of 300 mg/kg of butylated hydroxytoluene (BHT), a procedure known to enhance lung tumor development, produced cell hyperplasia only during the first 2 weeks; later the mice became resistant to the action of BHT. In animals treated with piperonyl butoxide prior to BHT, cell proliferation was abolished. BHT still had a small but significant enhancing effect on tumor development. However, this effect was dwarfed by the observation that piperonyl butoxide alone greatly inhibited tumor development. The data do not allow exclusion of alveolar cell hyperplasia as a mechanism in BHT-mediated enhancement of mouse lung tumor development.
Effects of non-native plants on the native insect community of Delaware

Due to the lack of a co-evolutionary history, the novel defenses presented by introduced plants may be insurmountable to many native insects. Accordingly, non-native plants are expected to support less insect biomass than native plants. Further, native insect specialists may be more affected by introduced plants than native generalist herbivores, resulting in decreased insect diversity on non-native plants due to the loss of specialists. To test these hypotheses, we used a common garden experiment to compare native insect biomass, species richness, and the proportion of native specialist to native generalist insects supported by 45 species of woody plants. Plants were classified into three groupings, with 10 replicates of each species: 15 species native to Delaware (Natives), 15 non-native species that were congeneric with a member of the Native group (Non-native Congeners), and 15 non-native species that did not have a congener present in the United States (Aliens). Native herbivorous insects were sampled in May, June, and July of 2004 and 2005. Overall, insect biomass was greater on Natives than Non-native Congeners and Aliens, but insect biomass varied unpredictably between congeneric pair members. Counter to expectations, Aliens held more insect biomass than did Non-native Congeners. There was no difference in species richness or the number of specialist and generalist species collected among the three plant groupings in either year, although our protocol was biased against sampling specialists. If these results generalize to other studies, loss of native insect biomass due to introduced plants may negatively affect higher trophic levels of the ecosystem.
Evaluation of the effectiveness of a teratogen information service: a survey of patient and professional satisfaction.

We have evaluated the effectiveness of the Wisconsin Teratogen Project (WTP), a teratogen information service, using two retrospective surveys. We surveyed medical professionals who utilized the WTP and patients who had received teratogen counseling in a clinic setting. The results from the medical professional survey indicated that medical professionals rely on the WTP for accurate and convenient teratogen information. A tendency to rely on the Physician's Desk Reference as an alternative resource was noted, reinforcing the need to encourage professionals to use teratogen information service projects. Major findings and conclusions from the patient survey included: patients found counseling to be most helpful if, whenever possible, numeric risks were provided; recommendations made in the absence of known risk were not considered by patients to be helpful for providing reassurance; overall compliance with recommendations was high but behavioral recommendations seemed to reduce reassurance and increase dissatisfaction with the service for some patients; and pregnant women exposed to low-dose ionizing radiation were more likely to have considered termination of pregnancy prior to referral but were not more likely to terminate following counseling. Our findings suggest that although the WTP is considered an effective service overall, teratogen counselors should give special consideration to patient and counseling characteristics as these can significantly influence the perception of the risk counseling provided. Particular attention should be given to patients with low-dose ionizing radiation exposure, since misperception of its teratogenic risk is extremely common. © 1993 Wiley-Liss, Inc.
A characterization of the moon radiation environment for radiation analysis

Abstract The radiation environment found on the surface of the Moon is shown and applied to different possible lunar mission scenarios. Models for the primary particle environment to be found on the Moon due to galactic cosmic rays (GCR) and solar particle events (SPE) have been used, with solar modulation and surface backscattering patterns taken into account. The surface itself has been modeled as regolith and bedrock. Particle transport has been performed with both deterministic and Monte Carlo approaches. A good agreement is found between the two methods.
Dark-pause measurements in a high-pressure arc discharge

Dwell or dark pause measurements of shock tube driver high pressure arc discharge for various gases
An approach to developing an alternative hot work die steel

This paper evaluates an approach to developing a steel which combines resistance to softening on tempering with an economical use of alloy elements. To obtain the desired tempering behavior advantage has been taken of the ability of non-carbide forming elements to enhance the secondary hardening response and the tendency of vanadium additions to reduce the coarsening rate of Mo2C. Five alloys were investigated; these were a base secondary hardening steel, that base steel modified by the addition of 2 wt pct silicon and by the combined addition of 1 wt pct silicon and 1 wt pct aluminum. To these two modified alloys were made additions of 0.4 wt pct vanadium. It was found that both types of additions without vanadium enhance the secondary hardening response to the same significant degree. Both of these alloys soften rapidly as the tempering temperature is increased above 600 °C. However, with the addition of vanadium, hardnesses over RgC 50 are obtained after tempering at 650 °C. While silicon additions appear indispensable to this resistance to softening on tempering, silicon also favors the retention of primary carbides after austenitizing and, if present in sufficient amounts, can cause brittle intergranular fracture after tempering at high temperatures.
Eolian sediment responses to late Quaternary climate changes: Temporal and spatial patterns in the Sahara

Abstract This paper presents a compilation of eolian-based records of late Quaternary climate changes in the Sahara. Although the data are relatively sparse, when viewed as a whole, they reveal a general pattern of widespread eolian sediment mobilization prior to 11,000 cal. years bp , eolian sediment stabilization from 11,000 to 5000 cal. years bp , and a return to widespread eolian sediment mobilization after 5000 cal. years bp . Furthermore, an eolian-based record from southern Tunisia reveals the existence of millennial-scale changes in eolian sediment behavior. These millennial-scale variations provide examples of eolian sediment responses to climate changes at a scale intermediate between seasonal and orbital (‘Milankovitch’) changes, and they are also coincident with abrupt atmospheric and oceanic changes. The general synchroneity of the eolian stratigraphic records and their coincidence with various oceanic and atmospheric changes suggest that global forcing mechanisms have influenced late Quaternary eolian sediment behavior in the Sahara.
Social Concerns of Post‐Mastectomy Women: Stigmata and Clothing

This paper explains post-mastectomy women's use of clothing as a method of coping with the negative social connotations of malignancy and disfigurement. We suggest that to avoid being stigmatized, post-mastectomy women employ techniques of “covering/passing” as described by Goffman (1963). The data on clothing concerns and strategies were obtained from post-mastectomy women using mail questionnaires and personal interviews. Attributes of clothing that were problematic included bust emphasis, shoulder bareness, and lack of sleeves. Respondents also reported difficulties with back closures. Attitudes to ward sexuality and concealment were examined along with attitudes toward ap pearance satisfaction as related to the most problematic garments-swimwear and nightwear. Attitudes toward sexuality were significantly related to concerns about presenting a good appearance in both swimwear and nightwear, whereas atti tudes toward concealment were only significantly related to concerns about nightwear.
Size dependence of the kinetic rate constant for phase transformation in TiO2 nanoparticles

The temperature dependence of a kinetic rate constant for a phase transformation is usually described by the Arrhenius equation, which comprises a preexponential factor multiplied by an exponential...
World wide study of the performance of a sodium guidestar

This study quantifies the feasibility for a mobile sodium guidestar system. Simulations are run using the High Energy Laser End-to-End Operational Simulation (HELEEOS) software package with global sodium layer climatology data. Sodium layer data used was collected from the Optical Spectrograph and Infrared Imaging System (OSIRIS) sensor package on board the Odin satellite from 2005 through 2011 and provides a detailed global representation of the variable sodium layer occurring at an altitude of approximately 90 km in the atmosphere. This data is used in conjunction with the HELEEOS atmospheric propagation modeling to create realistic sodium guidestar models. The atmospheric effects for the laser propagation scattering model and creation of the sodium guidestar are defined in the worldwide probabilistic climatic database available in the HELEEOS software package. The simulations run evaluated the performance of a guidestar as viewed from along the propagation path and from non-propagation path viewing angles for engagement scenarios in various locations on earth. HELEEOS includes a fast-calculating, first principles, worldwide surface to 100 km, with extensions above 100 km to account for the sodium layer, atmospheric propagation and characterization package. This package enables the creation of profiles of temperature, pressure, water vapor content, optical turbulence, atmospheric particulates and hydrometeors as they relate to line-by-line layer transmission, path and background radiance at wavelengths from the ultraviolet to radio frequencies. HELEEOS is able to produce realistic evaluations of laser propagation, imaging, and adaptive optics systems by use of an end to end directed energy propagation model that incorporates probabilistic, climatological data from temporally and spatially variable meteorological, aerosol, and turbulence profiles. Specifically, HELEEOS performs its propagation calculations utilizing the following algorithms, models and datasets: the Scaling for HEL and Relay Systems (SHaRE) scaling law algorithms, High Resolution Transmission (HITRAN) database for molecular absorption, Global Aerosol Dataset (GADS), Advanced Navy Aerosol Model (ANAM), the Adaptive Optical Compensation of Thermal Blooming (AOTB) model, various turbulence models, and other physics based atmospheric propagation algorithms. HELEEOS was developed by the United States Air Force Institute of Technology (AFIT) under the sponsorship of the High Energy Laser Joint Technology Office.
Two different complement receptors on human lymphocytes. One specific for C3b and one specific for C3b inactivator-cleaved C3b.

In the present study it was shown that normal peripheral lymphocytes have two different complement receptors: one for C3b (the immune adherence receptor) and one for C3b subsequent to its cleavage by C3b inactivator. The two receptors are not cross-reactive and were shown by tests with various antisera to be antigenically distinct. Both the immune adherence receptor and the receptor for C3b inactivator-cleaved C3b were found on normal peripheral lymphocytes and on cultured lymphoblastoid cells. In 15 out of 18 chronic lymphatic leukemia patients, the immune adherence receptor was either partially or completely missing from the peripheral lymphocytes, while the lymphocyte receptor for C3b inactivator-cleaved C3b was retained. Normal erythrocytes, on the other hand, were found to have only the immune adherence receptor. Granulocytes from normal peripheral blood appeared to have only a receptor for C3b and did not have a receptor for C3b inactivator-cleaved C3b.
MIRSI: a Mid-InfraRed Spectrometer and Imager

MIRSI (Mid-InfraRed Spectrometer and Imager) is a mid-infrared camera system recently completed at Boston University that has both spectroscopic and imaging capabilities. MIRSI is uniquely suited for studies of young stellar objects and star formation, planetary and protoplanetary nebulae, starburst galaxies, and solar system objects such as planets, asteroids, and comets. The camera utilizes a 320 x 240 Si:As Impurity Band Conduction (IBC) array developed for ground-based astronomy by Raytheon/SBRC. For observations at the Infrared Telescope Facility (IRTF), MIRSI offers a large field of view (1.6 arcmin x 1.2 arcmin) with a pixel scale of 0.3 arcsec, diffraction-limited spatial resolution, complete spectral coverage over the 8-14 μm and 17-26 μm atmospheric windows for both imaging (discrete filters and circular variable filter) and spectroscopy (10 and 20 μm grisms), and high sensitivity (expected one-sigma point source sensitivities of 5 and 20 mJy at 10 and 20 μm, respectively, for on-source integration time of 30 seconds). MIRSI successfully achieved first light at the Mt. Lemmon Observing Facility (MLOF) in December 2001, and will have its first observing run at the IRTF in November 2002. We present details of the system hardware and software and results from first light observations.
A MULTILEVEL APPROACH TO SOLVING THE BLACK–SCHOLES EQUATION

In this manuscript, we develop a multilevel framework for the pricing of a European call option based on multiresolution techniques. In this approach, the Black–Scholes equation is transformed via finite differences into a system of linear equations, where the form of the implicit operator is used to construct coarse grid projectors. The reduction of the computational resource is achieved by truncating small wavelet coefficients. However, because traditional wavelets fail to prevent oscillations from developing in the Greeks, a multilevel approach is used to retain smoothness in Gamma by incorporating derivative information into the multiresolution analysis.
Neuropsychological presentation of ganser symptoms

We describe a patient with memory complaints whose history of head injury, polysubstance abuse and positive neurological findings suggested the presence of dementia. Neuropsychological testing revealed inconsistent performance plus multiple verbal and visuospatial approximate answers leading to the diagnosis of a Ganser episode. This case illustrates the importance of neuropsychological assessment in diagnosing Ganser symptoms and in differentiating this disorder from organic conditions and malingering.
The effects of cholinergic agents upon fixated behavior.

A group of male albino rats were subjected to the Maier paradigm (insoluble problem followed by a soluble problem) using the Lashley jumping stand. Forty-two animals which failed the soluble problem by adopting a position stereotype were then randomly assigned to eight drug groups in a 2×2 design. Animals were guided to the correct window on odd days but received no guidance on even days. Animals received either pilocarpine nitrate (5.0 mg/kg) or scopolamine hydrobromide (1.0 mg/kg) in one of three different sequences. These sequences included drug on both odd and even days (drug-drug), only on the odd day (drug-no drug), or only on the even day (no drug-drug). One other drug group received scopolamine methylbromide (1.0 mg/kg) in a drug-no drug sequence, while the control group received saline on both days. Results indicated that animals receiving pilocarpine in the drug-drug and no drug-drug sequence solved significantly faster than the controls, while all the drugno drug groups showed significantly poorer solution rates. It was concluded that pilocarpine may enable animals to inhibit punished behavior patterns and thus hasten the extinction of fixated responses, but that due to the inconclusive scopolamine data this pilocarpine effect may not be due to its cholinomimetic properties.
The influence of autocorrelation in signature extraction: An example from a geobotanical investigation of Cotter Basin, Montana

The presence of positive serial correlation (autocorrelation) in remotely sensed data results in an underestimate of the variance-covariance matrix when calculated using contiguous pixels. This underestimate produces an inflation in F statistics. For a set of Thematic Mapper Simulator data (TMS), used to test the ability to discriminate a known geobotanical anomaly from its background, the inflation in F statistics related to serial correlation is between 7 and 70 times. This means that significance tests of means of the spectral bands initially appear to suggest that the anomalous site is very different in spectral reflectance and emittance from its background sites. However, this difference often disappears and is always dramatically reduced when compared to frequency distributions of test statistics produced by the comparison of simulated training sets possessing equal means, but which are composed of autocorrelated observations.
The influence of winter severity, predation and senescence on moose habitat use.

Summary 1. Habitat use is widely known to be influenced by abiotic and biotic factors, such as climate, population density, foraging opportunity and predation risk. The influence of the life-history state of an individual organism on habitat use is less well understood, especially for terrestrial mammals. 2. There is good reason to expect that life-history state would affect habitat use. For example, organisms exhibiting poor condition associated with senescence have an increased vulnerability to predation and that vulnerability is known to alter habitat use strategies. 3. We assessed the influence of life-history stage on habitat use for 732 moose (Alces alces) killed by wolves (Canis lupus) over a 50-year period in Isle Royale National Park, an island ecosystem in Lake Superior, USA. We developed regression models to assess how location of death was associated with a moose’s life-history stage (prime-aged or senescent), presence or absence of senescent-associated pathology (osteoarthritis and jaw necrosis), and annual variation in winter severity, moose density and ratio of moose to wolves, which is an index of predation risk. 4. Compared to senescent moose, prime-aged moose tend to make greater use of habitat farther from the shoreline of Isle Royale. That result is ecologically relevant because shoreline habitat on Isle Royale tends to provide better foraging opportunities for moose but is also associated with increased predation risk. During severe winters prime-aged moose tend to make greater use of habitat that is closer to shore in relation to senescent-aged moose. Furthermore, moose of both age classes were more likely to die in riskier, shoreline habitat during years when predation risk was lower in the preceding year. 5. Our results highlight a complicated connection between life history, age-structured population dynamics and habitat-related behaviour. Our analysis also illustrates why intraspecific competition should not be the presumed mechanism underlying density-dependent habitat use, if predation risk is related to density, as it is expected to be in many systems.
Identification of Residues Surrounding the Active Site of Type A Botulinum Neurotoxin Important for Substrate Recognition and Catalytic Activity

Type A botulinum neurotoxin is one of the most lethal of the seven serotypes and is increasingly used as a therapeutic agent in neuromuscular dysfunctions. Its toxic function is related to zinc-endopeptidase activity of the N-terminal light chain (LC) on synaptosome-associated protein-25 kDa (SNAP-25) of the SNARE complex. To understand the determinants of substrate specificity and assist the development of strategies for effective inhibitors, we used site-directed mutagenesis to investigate the effects of 13 polar residues of the LC on substrate binding and catalysis. Selection of the residues for mutation was based on a computational analysis of the three-dimensional structure of the LC modeled with a 17-residue substrate fragment of SNAP-25. Steady-state kinetic parameters for proteolysis of the substrate fragment were determined for a set of 16 single mutants. Of the mutated residues non-conserved among the serotypes, replacement of Arg-230 and Asp-369 by polar or apolar residues resulted in drastic lowering of the catalytic rate constant (k(ca)), but had less effect on substrate affinity (K(m)). Substitution of Arg-230 with Lys decreased the catalytic efficiency (k(cat)/K(m)) by 50-fold, whereas replacement by Leu yielded an inactive protein. Removal of the electrostatic charge at Asp-369 by mutation to Asn resulted in 140-fold decrease in k(cat)/K(m). Replacement of other variable residues surrounding the catalytic cleft (Glu-54, Glu-63, Asn-66, Asp-130, Asn-161, Glu-163, Glu-170, Glu-256), had only marginal effect on decreasing the catalytic efficiency, but unexpectedly the substitution of Lys-165 with Leu resulted in fourfold increase in k(cat)/K(m). For comparison purposes, two conserved residues Arg-362 and Tyr-365 were investigated with substitutions of Leu and Phe, respectively, and their catalytic efficiency decreased 140- and 10-fold, respectively, whereas substitution of the tyrosine ring with Asn abolished activity. The altered catalytic efficiencies of the mutants were not due to any significant changes in secondary or tertiary structures, or in zinc content and thermal stability. We suggest that, despite the large minimal substrate size for catalysis, only a few non-conserved residues surrounding the active site are important to render the LC competent for catalysis or provide conformational selection of the substrate.
Normal and disordered reticulocyte maturation.

Purpose of review Reticulocyte remodeling has emerged as an important model for the understanding of vesicular trafficking and selective autophagy in mammalian cells. This review covers recent advances in our understanding of these processes in reticulocytes and the implications for erythroid development.
Picard sequences with every orbit containing infinitely many perfect n-powers

Abstract Text Finding a function which generates a sequence via iteration whose values at one or many points in its domain satisfy certain prescribed properties, i.e., finding a function such that the Picard orbit(s) of one or many points in its domain which possess some given properties, is an interesting problem. Given any positive integer n greater than one, we construct in this paper families of functions on the natural numbers such that the sequence of the iterations of each of these functions at any positive integer s contains infinitely many perfect n-powers. In terms of Picard sequences, this amounts to constructing a function whose Picard orbit at every point in its domain contains infinitely many perfect n-powers. Video For a video summary of this paper, please visit http://www.youtube.com/watch?v=wJqaXyB2pdo .
The continuous countercurrent moving bed chromatographic reactor

Abstract The physical basis upon which the continuous countercurrent moving bed chromatographic reactor is able to shift chemical equilibrium to favor a reaction product, and to give the product in a highly purified state, is discussed. Preliminary experimental results for the hydrogenation of 1,3,5-trimethyl benzene are given. The design and construction of an improved countercurrent moving bed reactor is presented.
SREX: A NEWPROCESS FOR THE EXTRACTION AND RECOVERY OF STRONTIUM FROM ACIDIC NUCLEAR WASTE STREAMS

ABSTRACT A new process for the extraction and recovery of strontium from acidic waste streams is described. In this process, called SREX (for Strontium Extraction), strontium is extracted from acidic ( ≥ 1 M HNO3) solution using a 0.20M solution of di-t-butylcyclohexano-18-crown-6 in 1-octanol. Extracted strontium is readily stripped from the organic phase using either water or dilute (<0.05 M) HNO3. Tests of the process on a synthetic dissolved sludge waste solution show that only strontium, barium, and technetium are appreciably extracted by the crown ether. Prolonged exposure of the process solvent to nitric acid at elevated temperatures or to ≤ 50 Wh/L γ radiation from a 60Co source produces essentially no deterioration in its performance. Benchtop batch countercurrent extraction experiments show that 99.7% of the strontium initially present in a feed solution can be removed in only three extraction stages.
Some Physical Properties of Electrical Discharges on Contaminated-Surfaces

The various discharge phenomena caused by contamination of insulator surfaces were investigated by means of slow and fast oscillographic recordings of the discharge current. It was found that the surface discharges have distinct stages of development. The visual manifestations were recorded simultaneously with the current pulses, providing a good correlation and an exact physical interpretation. It was found that contaminated surface discharges can be classified in three main types: the arc, streamer, and glow. The arc discharge has a highly ionized plasma channel with a small voltage drop while the other two are of low ionization density and carry a relatively high voltage. The ignition mechanism was also investigated and explained. Both streamer and glow discharges are accompanied by steep current pulses and are believed to be responsible for the high-intensity radio noise associated with contaminated surface currents. The use of such pulses or bursts of current to evaluate insulator performance is critically discussed.
On the Direct Estimation of the Fundamental Matrix

The fundamental matrix is a central construct in the analysis of images captured from a pair of cameras and many feature-based methods have been proposed for its computation. In this paper, we propose a direct method for estimating the fundamental matrix where the motion between the frames is small (e.g. between successive frames of a video). To achieve this, a warping function is presented for the fundamental matrix by using the brightness constancy constraint in conjunction with geometric constraints. Using this warping function, an iterative hierarchical algorithm is described to recover accurate estimates of the fundamental matrix. We present results of experimentation to evaluate the performance of the proposed approach and demonstrate improved accuracy in the computation of the fundamental matrix.
Estrous correlated modulations of circadian and ultradian wheel-running activity rhythms in LEW/Ztm rats

Estrogen treatment alters the expression of ultradian activity rhythms in male and female LEW/Ztm rats. This finding raises the possibility that the expression of ultradian rhythms may vary on different days of the estrous cycle. To test this hypothesis, we recorded the circadian and ultradian wheel-running activity rhythms of entrained (LD 12:12) and free-running sexually mature LEW/Ztm females during their 4- or 5-day estrous cycle. The mean daily activity, the duration of activity, the circadian period of activity, and the occurrence of ultradian rhythms differed significantly among the days of the estrous cycle. In LD 12:12, the phase angle difference between the beginning of activity and light offset varied reliably in 5-day cycling animals. The highest daily mean of activity, the longest duration, and the shortest circadian period length were observed on the day of estrus in both entrained and free-running animals. The day of estrus was characterized by a constant high level of activity throughout the activity phase, while the days following ovulation showed a bi- or trimodal activity pattern. Power spectrum analysis revealed significant ultradian components for the days of metestrus and diestrus, but only circadian components for the days of proestrus and estrus. These results were interpreted as indicating that endogenous changes in circulating hormone levels can induce changes in the ultradian and circadian patterns of wheel-running activity in LEW/Ztm rats.
Stratigraphy and correlation of the Late Wisconsinan glacial events in the Lake Michigan basin

Meaningful correlations of late glacial events between areas as distant as the Great Lakes and southern Quebec depend on the establishment of detailed local chronologies, mostly from studies in the Lake Michigan basin and the St. Lawrence lowland now holding the most promise for a radiometrically controlled record of the late glacial (ca. 14,000-8000). Based on recent investigations in the Lake Michigan region, we propose a revision in the deglaciation pattern and stratigraphie nomenclature. Although oscillatory glacial retreat began to dominate over readvance about 17,000 years BP, we define late Wisconsinan as beginning at ca. 14,000 when the ice withdrew from the Lake Border Morainic system. Following the Cary-Port Huron retreat, the ice read-vanced (350 km) depositing the red Shorewood Till. This was followed by a minor retreat and then by deposition of the Manitowoc Till. Continued retreat eventually uncovered an eastward outlet and Lake Chicago dropped to the Two Creeks low-water level. This deglaciation was not as extensive as previously assumed. The post-Twocreekan readvance (125 km) to the Two Rivers moraine oc-cured around 11,850 years BP. This sequence argues for a normal, climatically controlled progressive deglaciation rather than one interrupted by a major post-Twocreekan (formally Valderan) surge. Based on the knowledge that the Valders Till is late Woodfordian in age we have proposed the time-stratigraphic term "Greatlakean" as a substitute for the now misleading term "Valderan".
Selective prey avoidance learning in the predatory sea slug pleurobranchaea californica

Predator–prey interactions involving aposematic signaling, where predators learn the warning cues of well-defended prey, are clear examples of cost–benefit decisions in foraging animals. However, knowledge of the selectivity of predator learning and the natural conditions where it occurs is lacking for those foragers simpler in brain and body plan. We pursued the question in the sea slug Pleurobranchaea californica , a generalist forager of marked simplicity of body form, nervous system and behavior. This predator exploits many different types of prey, some of which are costly to attack. When offered Flabellina iodinea , an aeolid nudibranch with a stinging defense, biting attack was followed by rapid rejection and aversive turns. The predatory sea slug rapidly learned avoidance. Notable exceptions were animals with extremely high or low feeding thresholds that either ignored F. iodinea or completely consumed it, respectively. Experienced slugs showed strong avoidance of F. iodinea for days after exposure. Aposematic odor learning was selective: avoidance was not linked to change in feeding thresholds, and trained animals readily attacked and consumed a related aeolid, Hermissenda crassicornis . For P. californica , aposematic learning is a cognitive adaptation in which sensation, motivation and memory are integrated to direct cost–benefit choice, and thereby lend flexibility to the generalist's foraging strategy.
Performance analysis for M-ary orthogonal FSK with hybrid selection/equal-gain combining over Nakagami fading channels

In this paper, we consider a diversity system with M-ary orthogonal FSK and hybrid selection/equal-gain combining (HS/EGC) which combines, per the EGC rule, the L/sub c/ strongest diversity branches out of the L available ones. We assume independent Nakagami fading on the diversity branches with unequal fading parameters and unequal signal-to-noise ratios (SNRs) and derive different closed-form expressions for the average symbol error probability (SEP). The closed-form expressions are in canonical form as a weighted sum of elementary closed-form expressions, which are the closed-form expressions for a diversity system with EGC in various Nakagami fading environments.
Reflective Teaching: A Process for Analyzing Journals of Preservice Educators

Researchers are attempting to establish the importance of reflection within the teaching profession. As teacher educators more frequently require journal writing as one form of reflective practice in preservice teacher preparation, it becomes important that a process be established for analyzing this type of reflective thought. In this study, a content and descriptive analysis of reflective journal entries was conducted to define operational categories of reflective thought. Six CRT students maintained weekly journals in which they were required to reflect upon their instruction in their student teaching on a daily basis. Data then were analyzed in four stages: (a) classifying entries as problems, successes, or general issues, (b) reclassifying problem and success entries into teaching categories (behavior, planning, instruction, and learning environment), (c) identifying the levels of reflective thought used in addressing a problem, and (d) identifying components of successful entries. The final outcome ...