cssi/SciSciGPT-SciSciNet huggingface dataset:
Incorporation of Anatomical MR Data for Improved Dunctional Imaging with PET

A statistical approach to PET image reconstruction offers several potential advantages over the filtered backprojection method currently employed in most clinical PET systems: (1) the true data formation process may be modeled accurately to include the Poisson nature of the observation process and factors such as attenuation, scatter, detector efficiency and randoms; and (2) an a priori statistical model for the image may be employed to model the generally smooth nature of the desired spatial distribution and to include information such as the presence of anatomical boundaries, and hence potential discontinuities, in the image. In this paper we develop a Bayesian algorithm for PET image reconstruction in which a magnetic resonance image is used to provide information about the location of potential discontinuities in the PET image. This is achieved through the use of a Markov random field model for the image which incorporates a “line process” to model the presence of discontinuities. In the case where no a priori edge information is available, this line process may be estimated directly from the data. When edges are available from MR images, this information is introduced as a set of known a priori line sites in the image. It is demonstrated through computer simulation, that the use of a line process in the reconstruction process has the potential for significant improvements in reconstructed image quality, particularly when prior MR edge information is available.
A Review of “Challenging Silence, Challenging Censorship”

School and public library services are gatekeepers to information. While libraries are ethically bound to protect intellectual freedom and provide inclusive services to all, the actual state of bisexual, gay, lesbian, trans-identified, and two-spirited (BGLTT) collections in many libraries is limited or nonexistent. This review essay examines Challenging Silence, Challenging Censorship, a book of resources for public and school librarians on resisting censorship, creating inclusive collections, and introducing strategic policy initiatives to enhance patron access to BGLTT-themed materials and services.
Quantitative assessment of amide proton transfer (APT) and nuclear overhauser enhancement (NOE) imaging with extrapolated semisolid magnetization transfer reference (EMR) signals: II. Comparison of three EMR models and application to human brain glioma at 3 Tesla

Purpose To evaluate the use of three extrapolated semisolid magnetization transfer reference (EMR) methods to quantify amide proton transfer (APT) and nuclear Overhauser enhancement (NOE) signals in human glioma. Methods Eleven patients with high-grade glioma were scanned at 3 Tesla. aEMR2 (asymmetric magnetization-transfer or MT model to fit two-sided, wide-offset data), sEMR2 (symmetric MT model to fit two-sided, wide-offset data), and sEMR1 (symmetric MT model to fit one-sided, wide-offset data) were assessed. ZEMR and experimental data at 3.5 ppm and −3.5 ppm were subtracted to calculate the APT and NOE signals (APT# and NOE#), respectively. Results The aEMR2 and sEMR1 models provided quite similar APT# signals, while the sEMR2 provided somewhat lower APT# signals. The aEMR2 had an erroneous NOE# quantification. Calculated APT# signal intensities of glioma (∼4%), much larger than the values reported previously, were significantly higher than those of edema and normal tissue. Compared with normal tissue, gadolinium-enhancing tumor cores were consistently hyperintense on the APT# maps and slightly hypointense on the NOE# maps. Conclusion The sEMR1 model is the best choice for accurately quantifying APT and NOE signals. The APT-weighted hyperintensity in the tumor was dominated by the APT effect, and the MT asymmetry at 3.5 ppm is a reliable and valid metric for APT imaging of gliomas at 3T.Magn Reson Med 75:1630–1639, 2016. © 2015 Wiley Periodicals, Inc.
RF link power control with field test data

Associated with the rapid concentration of forces there is the issue of EMC/EMI problems among various radios in a theater. The general issue is about how various narrow band radios can be brought to use in a battle field with automated RF power management. The study in this paper is restricted to point to point link power control. The concept of power management should also be applied to a number of radios in a network structure. In order to achieve minimum possible cochannel interference a party at the link ends should radiate minimum power. It should be only enough to establish an adequate service (BER) for that particular distance and no more. In an ideal situation the path loss is proportional to the logarithm of the distance and transmission frequency. In a real situation the path loss is also affected by the terrain features. Radio links in battle field are fading limited and interference limited from all sources. Channel fading has been attributed to multipath, scattering, and shading. In this study an UHF link with 19.2 kilo baud modems were setup between a base node and a mobile node. The goal is to study possible power control algorithms that can track a minimal RF power for a particular BER. Output RF power is attenuated at increments in the algorithm. A range of RF power is allowed to change until a preset BER is achieved. The field tested data and the simulation results are presented.
Chronic Obstructive Pulmonary Disease (COPD): Biological Mechanisms

Airway obstruction in chronic obstructive pulmonary disease (COPD) is caused by narrowing of small airways as a result of inflammation and fibrosis and the disruption of their alveolar attachments as a result of emphysema. COPD is characterized by a complex inflammatory disease process that increases as the disease progresses, which leads to increasing airflow limitation. Many inflammatory cells and mediators have now been implicated in the pathogenesis of COPD. Increased numbers of macrophages, neutrophils, T-lymphocytes (particularly CD8+ cells) and B-lymphocytes have been observed, as well as the release of multiple inflammatory mediators (lipids, chemokines, cytokines, growth factors). Macrophages seem to play an important role in orchestrating the inflammatory process, which includes the recruitment of neutrophils and T-cells into small airways and lung parenchyma and the secretion of proteinases that lead to emphysema. A high level of oxidative and nitrative stress may amplify this inflammation through the reduction in histone deacetylase-2, which also results in corticosteroid resistance.
Can the iPhone Generation Reform the CCP

China is now praised as the land of opportunities. Its economy is booming and every entrepreneur or transnational corporation wants to open and expand its business in China. Over the last three decades the country has sustained growth rates at levelsthat exceed previous trajectories of the ‘Asian Tigers’, the last generation of countries to join the ‘developed world.’ Yet, China remains the world’s largest developing country. The question is: Can China sustain this rate of growth? And, if it does, what does this mean for the world order—both economic and political?
Liftings of tree-structured Markov chains

A "lifting" of a Markov chain is a larger chain obtained by replacing each state of the original chain by a set of states, with transition probabilities defined in such a way that the lifted chain projects down exactly to the original one. It is well known that lifting can potentially speed up the mixing time substantially. Essentially all known examples of efficiently implementable liftings have required a high degree of symmetry in the original chain. Addressing an open question of Chen, Lovasz and Pak, we present the first example of a successful lifting for a complex Markov chain that has been used in sampling algorithms. This chain, first introduced by Sinclair and Jerrum, samples a leaf uniformly at random in a large tree, given approximate information about the number of leaves in any subtree, and has applications to the theory of approximate counting and to importance sampling in Statistics. Our lifted version of the chain (which, unlike the original one, is non-reversible) gives a significant speedup over the original version whenever the error in the leaf counting estimates is o(1). Our lifting construction, based on flows, is systematic, and we conjecture that it may be applicable to other Markov chains used in sampling algorithms.
Hybrid DC Power System for Pulse Load Application: Design, Modeling and Operation

In this work, the design of a hybrid DC power system for pulse load applications is considered. In micro grid power systems, pulse loads are particularly problematic since the load short-time power demands are very high and the total system inertia is finite. The requirements of the system in terms of power and energy were described. Also, the design aspects of the two commonly used configurations of the hybrid energy storage system, passive hybrid and active hybrid, are explained in detail. A 320-V laboratory scale hybrid DC micro grid incorporating different types of loads is developed for this study. This micro grid is controlled through a three level control and energy management system. A detailed model of the hybrid dc micro grid including different energy storage systems for transient and dynamic study is presented. The micro grid is experimentally tested and its performances are compared with the simulation model under normal and transient fault conditions. The results successfully validate both the experimental design of the system and the accuracy of the grid simulation model.
Increasing Rb and decreasing Rc with new heavy quarks.

If the b and c quarks mix with new heavy quarks of weak isospin I_3 = -1 and 0 respectively, then the Z -> b b(bar) (c c(bar)) rate is necessarily greater (smaller) than that of the standard model. This may be the reason for the R_b excess and R_c deficit observed at LEP. A possible consequence of this scenario is the prospective discovery of a new quark x with the dominant decay x -> c h, then h -> b b(bar), where h is a neutral Higgs boson.
Fetal responses to maternal exercise in the sheep

Abstract Fetal responses to maternal exercise were studied in twelve long-term sheep preparations. After hysterotomy, a polyvinyl catheter was inserted into the fetal aorta via the femoral artery (11 fetuses) or via a ligated umbilical artery (4 fetuses) and exteriorized. Seven to ten days later, the ewes were exercised on a treadmill (2.0 to 2.5 miles per hour) for 30 to 60 min. Maternal and fetal arterial pressures, heart rates, and blood pH, Po 2 , and Pco 2 were monitored before exercise, at the end of exercise, and after a 30 min. recovery period. The results indicate that fetal responses to maternal exercise generally follow those of the mother. A significant increase in fetal pH and decrease in fetal Pco 2 were observed at the end of exercise, and these were associated with maternal hyperventilation and respiratory alkalosis. Moreover, a significant reduction in fetal Po 2 was noted with maternal exercise. A moderate increase in fetal heart rate was also observed with insignificant change in mean arterial blood pressure. The responses were similar in both fetuses with intact umbilical circulation and those with a ligated umbilical artery. However, the latter fetuses had a lower pre-exercise Po 2 level and had greater decreases of oxygen tension with maternal exercise. The observed changes were reversible after 30 min. of recovery. These observations suggest that moderately severe maternal exercise may be detrimental to fetuses with some compromise of the umbilical circulation but that the normal fetus tolerates maternal exercise well. It is suggested that the decrease in fetal Po 2 is due primarily to reduction in uterine flow during exercise and partially to changes of the oxygen affinities of maternal and fetal hemoglobins consequent to respiratory alkalosis.
Explorer at Los Alamos: a library for the future

Since 1993, Los Alamos National Laboratory has been developing World Wide Web (WWW) applications to facilitate access to vast quantities of information critical to the successful operation of a nuclear weapons facility. Explorer is a Web based tool that integrates full text search and retrieval technology, custom user interfaces, user friendly navigation tools, extremely large document collections, and data collection and workflow applications. Explorer's first major thrust was to enable quick access to regulatory and policy information used by Department of Energy facilities throughout the country. Today, Explorer users can easily search document collections containing millions of pages of information, scattered across Web sites around the country. Over fifteen large applications containing multiple collections are searchable through Explorer, and the subject areas range from DOE regulations to quality management related resources to technology transfer opportunities. Explorer has succeeded because it provides quick and easy access to stored data across the Web; it saves time and reduces costs in comparison with traditional information distribution, access, and retrieval methods.
Formulation, Uniqueness, and Solution Strategies

The essential equations of the linear theory of elasticity have been derived. Restated concisely are the equilibrium conditions, the kinematic relations with the compatibility constraints, and the constitutive law for isotropic materials. These equations are combined in force, displacement, and mixed formulations. Also the necessary and sufficient conditions governing the uniqueness of a solution are established, and some fundamental approaches to the solution of an elasticity problem are introduced.
Ratio of prey to predators in community food webs

WHETHER the diversity of resources limits the diversity of consumers, and specifically, whether the number of kinds of prey limits the number of kinds of predators, has been of continuing interest in theoretical ecology and wildlife management1–3. Food webs from the ecological literature were collected in machine readable form to study this question empirically. We report here that in community food webs, the ratio of the number of kinds of prey to the number of kinds of predators seems to be constant, near 3/4. This invariance has not been noticed in earlier studies of individual cases.
Lifecourse Socioeconomic Position and Weight Change among Blacks: The Pitt County Study

Objective: The elevated prevalence of obesity among U.S. blacks has been attributed to low socioeconomic position (SEP), despite inconsistent empirical findings. It is unclear whether low SEP at various lifecourse stages differentially influences adulthood BMI and BMI change. Research Methods and Procedures: Among 1167 black adults in the Pitt County Study, we examined independent cross-sectional and longitudinal associations between SEP, measured in childhood and adulthood, and BMI and 13-year BMI change. Low vs. high childhood SEP was measured by parental occupation and childhood household deprivation; low vs. high adulthood SEP was assessed by employment status, education, and occupation. Using childhood and adulthood SEP, four lifecourse SEP categories were created: low-low, low-high, high-low, high-high. Results: We found no consistent associations between SEP and BMI or BMI change among men. Among women, we observed the expected inverse association between SEP and BMI at baseline. In multivariable-adjusted analyses, socioeconomically advantaged women demonstrated larger 13-year increases in BMI: skilled vs. unskilled parental occupation (6.1 vs. 4.8 kg/m2, p = 0.04); college-educated vs. < high school (6.2 vs. 4.5 kg/m2, p = 0.04); white-collar vs. blue-collar job (5.8 vs. 4.8 kg/m2, p = 0.05); and high-high vs. low-low lifecourse SEP (6.5 vs. 4.6 kg/m2, p = 0.02). Discussion: For women in this black cohort, lower SEP predicted earlier onset of obesity; however, low SEP was less predictive of BMI increases over time. Our findings demonstrate complex patterns of association between SEP and BMI change among black women.
A Thrombospondin-1 Antagonist of Transforming Growth Factor-β Activation Blocks Cardiomyopathy in Rats with Diabetes and Elevated Angiotensin II

In diabetes and hypertension, the induction of increased transforming growth factor-β (TGF-β) activity due to glucose and angiotensin II is a significant factor in the development of fibrosis and organ failure. We showed previously that glucose and angiotensin II induce the latent TGF-β activator thrombospondin-1 (TSP1). Because activation of latent TGF-β is a major means of regulating TGF-β, we addressed the role of TSP1-mediated TGF-β activation in the development of diabetic cardiomyopathy exacerbated by abdominal aortic coarctation in a rat model of type 1 diabetes using a peptide antagonist of TSP1-dependent TGF-β activation. This surgical manipulation elevates initial blood pressure and angiotensin II. The hearts of these rats had increased TSP1, collagen, and TGF-β activity, and cardiac function was diminished. A peptide antagonist of TSP1-dependent TGF-β activation prevented progression of cardiac fibrosis and improved cardiac function by reducing TGF-β activity. These data suggest that TSP1 is a significant mediator of fibrotic complications of diabetes associated with stimulation of the renin-angiotensin system, and further studies to assess the blockade of TSP1-dependent TGF-β activation as a potential antifibrotic therapeutic strategy are warranted.
Electrocardiographic artifacts simulating atrial flutter.

To the Editor.— Proper interpretation of an electrocardiogram (ECG) depends upon the competence of the equipment, the technician, and the electrocardiographer. We have recently observed an unusual electrocardiogram in which a broken wire caused simulation of atrial flutter. The ECG (Figure) performed on a 10-year-old Cambridge ECG recorder, was initially interpreted as demonstrating an unusual flutter mechanism. However, this was only evident in leads II, III, and aV F . The remaining leads, although demonstrating 60 cycles interference, showed sinus rhythm and were otherwise normal. The technician alertly switched the channel selector from lead V 1 to standard lead II and the flutter mechanism was again seen. At this point an artifact was suspected and verified to be a broken wire in the left leg electrode. Although the artifact in this particular case was rather easy to detect because the arrhythmia seemed to occur only in the inferior leads, had this
Ferromanganese Deposits in the Saranac Lake System New York

Abstract In situ observations of ferromanganese deposits have been made in the Saranac lake system, New York. The ferromanganese occurs on shallow, sandy bottoms as rims and coatings on cobbles and exposed bedrock. The deposits have a rather high Fe: Mn ratio, averaging 4, and are otherwise chemically similar to freshwater ferromanganese reported in the literature. In cross-section, the rims exhibit a layered structure resulting from alternating periods of high and low Mn deposition at the leading edge of the rims, presumably in response to changing physical or biological conditions in the environment.
The effect of β-subunit assembly on function and localization of the colonic H+,K+-ATPase α-subunit

The effect of β-subunit assembly on function and localization of the colonic H + ,K + -ATPase α-subunit. Background Previous experiments from our laboratory have demonstrated that HKα 2 coimmunoprecipitated with β 1 -Na + ,K + -ATPase. Although HKα 2 is expressed abundantly in the apical membrane of distal colon, the demonstration that β 1 localizes to this same membrane in distal colon has not been demonstrated previously. Methods Immunolocalization was performed in distal colon using a polyclonal antibody against HKα 2 and a monoclonal antibody against β 1 . Results The results demonstrate that HKα 2 localizes to the apical membrane. Two pools of β 1 -Na + ,K + -ATPase were detected. The first localized to the apical membrane. The second pool was detected in the basolateral membrane when distal colon sections were deglycosylated with glycosidase F. Therefore, our results demonstrate that β 1 localizes to the apical membrane with HKα 2 , and supports the view that β 1 is the physiologic β-subunit for HKα 2 . We tested, therefore, the efficiency of the two β-subunits expressed in distal colon (β 1 and β 3 ) to support the activity of HKα 2 . Human embryonic kidney HEK-293 cells were transiently cotransfected with HKα 2 plus β 1 or HKα 2 plus β 3 . Subsequently, 86 Rb + -uptake and plasma membrane localization were evaluated. The results demonstrate that both HKα 2 /β 1 and HKα 2 /β 3 support 86 Rb + -uptake. However, 86 Rb + -uptake measured in the cells cotransfected with HKα 2 plus β 1 exceeded that measured in cells expressing HKα 2 /β 3 . Fluorescence microscopy using enhanced green fluorescent protein cloned at the amino-terminus of HKα 2 demonstrated protein migration to the plasma membrane in cells cotransfected with EGFP-HKα 2 plus β 1 . In contrast, in cells cotransfected with EGFP-HKα 2 plus β 3 , the vast majority of the protein remained confined to intracellular compartments. The significantly higher 86 Rb + -uptake corresponded to additional localization of HKα 2 to the plasma membrane when coexpressed with β 1 compared to β 3 . Conclusion Taken together, these and previous results from our laboratory indicate that β 1 -Na + ,K + -ATPase is likely to represent the most physiologic and efficient subunit for HKα 2 assembly in distal colon.
Mutagenesis by AID, a molecule critical to immunoglobulin hypermutation, is not caused by an alteration of the precursor nucleotide pool.

Abstract The novel cytidine deaminase, AID, plays a critical role in immunoglobulin (Ig) hypermutation. Its possible modes of action include deamination of an RNA transcript that encodes a molecule involved in these processes, deamination of the DNA encoding the variable regions of immunoglobulin genes, or deamination of monomeric cytidine or deoxycytidine (dC) nucleotide generating a mutagenic imbalanced nucleotide pool. We transformed AID into Escherichia coli cells and measured the nucleotide pools at 2 and 6 h following induction of expression. Although the majority of the cells expressed AID at the relevant time points, the nucleotide pools were unaltered. In addition, mutagenesis by AID expression in E. coli was not synergistically enhanced in a bacterial strain defective in dUTPase, an enzyme that prevents accumulation of dUTP in the nucleotide pool. Finally, while some AID-GFP fused molecules localized to nucleoids, and a significant portion appears to be distributed throughout the bacterial cell, the highest concentration seemed to localize to the cell poles. Chloramphenicol treatment, which detaches the nucleoids from the membrane, caused a further disassociation of AID-GFP from nucleoids suggesting that AID does not intrinsically bind DNA. These results strongly argue against a role for AID in mutagenesis by deamination of cytosine in the nucleotide pool, and suggest that while AID probably acts by deaminating cytosine in the DNA, it requires a protein partner for efficient localization to DNA.
Resonant extraction from three-sector low-spiral cyclotrons

Results of MSU studies of resonant extraction systems for a 40 MeV variable energy, multi-particle cyclotron are reviewed. Initial sections give a qualitative account of extraction principles. Following this, results of numerical studies of both radial and axial motion under many varying resonant conditions are considered and, for comparison, also a corresponding non-resonant condition. Final sections briefly review (a) initial design studies relative to deflector hardware, (b) performance estimates for the system, and (c) preliminary studies of techniques for achieving improved duty cycle.
How microcomputers and electronic spreadsheets can be used to educate industrial engineering students

Abstract This paper describes how microcomputers and electronic spreadsheets can be used to educate industrial engineering students in areas such as engineering economy, quality control, and operations management. The advantages and disadvantages of this technology are discussed, and sample problems from various industrial engineering subject areas are solved using the electronic spreadsheet approach proposed in this paper.
Considerations Regarding Antiplatelet Therapy in the Elderly

Adults over the age of 65 years represent more than half of the patients living with heart disease in the United States. However, the majority of the large, multi-center, randomized clinical trials that have led to the creation of the guidelines for antiplatelet therapy have enrolled only a small number of elderly patients. This article reviews the published data on antiplatelet therapy for coronary artery and cerebrovascular disease, focusing on elderly patients. We found evidence to support the use of aspirin for both primary and secondary prevention of ischemic heart disease, and of aspirin and clopidogrel in the setting of acute coronary syndromes and for stroke prevention in patients with atrial fibrillation not on anticoagulation. Further studies are needed to characterize the benefits and risks in the elderly of prasugrel, ticagrelor and the glycoprotein IIb/IIIa inhibitors.
Intracellular Cl − accumulation reduces Cl − conductance in inhibitory synaptic channels

Glycine increases Cl− conductance in neurones of the lamprey central nervous system and mimics the natural inhibitory transmitter pharmacologically1,2. We have used current noise produced by glycine to examine in more detail the characteristics of inhibitory channels in Muller cells in the brain stem reticular formation. The channels have large conductances and mean open times consistent with large amplitudes and long durations of spontaneously occurring inhibitory synaptic currents3. We now show that, unlike any post-junctional channels reported so far, their conductance decreases rapidly with increasing intracellular concentration of the permeant ion. This surprising behaviour is inconsistent with constant field theory4,5 and also with a single-site pore model such as proposed for cationic channels at the motor endplate6, both of which predict an increase in conductance with concentration. In addition, the decrease in conductance cannot be explained quantitatively by a two-site, single-file pore model such as proposed for K+ channels7 and Na+ channels8 in nerve and for gramicidin channels9. This property of the inhibitory channel may be functionally important in preventing intracellular Cl− accumulation during periods of intense synaptic activity when inhibition might otherwise convert progressively to excitation as the Cl− equilibrium potential became more and more positive.
An Automatic System for Processing Microelectrode Data

A data processing system has been designed and built which converts single unit microelectrode recordings obtained on analog magnetic tape into a punched paper tape record. The conversion process preserves the exact time sequence in which the neurological events occur. The punched paper tape record can be used to obtain hard copy via a "Flexowriter" and to punch IBM cards for computation on any one of a number of digital computing machines. It thereby permits detailed study by digital computers of such phenomena as spontaneous activity and adaptive cell processes during and after periods of stimulation. The basic method for obtaining the paper tape record is to slow down the playback of the original tape record by a factor of 50 or l00. This permits continuous analog to digital conversion of the intervals by a compact digital subsystem designed for this purpose. The measurements are encoded and presented to a tape perforator operating at 110 characters per second. A code character is inserted at the end of each interval measurement to identify the intervals as: stimulus-response, response-response, response-stimulus, stimulus-stimulus. Other uses of this coding symbol are possible.
Fatal refractory hyperkalemia due to tumor lysis during primary resection for hepatoblastoma

Infants with large, rapidly growing tumors of the liver who exhibit preoperative signs of tumor necrosis (elevated uric acid or K+), having received no prior chemotherapy or radiation therapy, may be at risk for acute hyperkalemia during operative manipulation of the mass. In these patients, consideration should be given to careful monitoring of serum potassium throughout operative manipulation; cardiopulmonary bypass, to protect the heart from acute hyperkalemia; or to primary biopsy of the tumor with resection planned after chemotherapy. A case of fatal refractory hyperkalemia due to tumor lysis during a trisegmentectomy for hepatoblastoma in a 7-month-old girl who presented with a large, rapidly growing tumor and hyperuricemia is described.
Experimental tests of water quality trading markets

Abstract Many watersheds in the U.S. have established water quality trading programs to help realize cost-effective reductions in water pollution; however, the success of these programs has been limited. This study highlights some of the unique features of water-based credit trading markets that may explain the lack of success, and uses laboratory experiments to isolate their effects. In particular, we compare two forms of a baseline-and-credit institution, a Pigouvian tax/subsidy regulation, and – characteristic of air quality programs – a textbook cap-and-trade regulation. Across these institutions we examine the effects of abatement technology adoption. We find that a baseline-and-credit program, when it requires firms to make upfront investments to generate tradable credits, is less efficient than cap-and-trade and tax/subsidy institutions. Furthermore, we find that when efficient trading requires costly technology adoption, institutions that involve inter-firm trading, including cap-and-trade, are less efficient than the tax/subsidy.
The effects of aging on hippocampal and cortical projections of the forebrain cholinergic system

It has been proposed that disruption of cholinergic input to the hippocampus and cortex contributes to the learning and memory deficits associated with aging. The data reviewed here, however, suggest that the oft-stated generalization that normal aging is characterized by disruption of cholinergic input to the hippocampus and cortex is not entirely correct. Instead it appears that age-related changes are not consistently found on measures such as the activity of ChAT or the content of ACh in these regions, basal levels of ACh release in cortex, and the number of cholinergic neurons in the basal forebrain (source of cholinergic input to the hippocampus and cortex). These observations suggest that unlike Alzheimer's disease, normal aging does not reliably produce a degeneration of the cholinergic innervation of the hippocampus and cortex. The responsivity of the cholinergic system, however, is altered during normal aging. ACh synthesis and stimulation-induced release of ACh are diminished in aged animals. Further, the electrophysiological response of postsynaptic neurons to ACh is reduced during aging. Although some regional differences in these age-related changes may be present, the generalization that the functioning of the cholinergic system is impaired during aging is probably accurate. Thus, investigation of these changes in the dynamic properties of cholinergic input to the hippocampus and cortex during aging may provide clarification of the relationship between cholinergic dysfunction and age-related decline in learning and memory and may also provide a more reasonable rationale for treatment approaches.
Experimental and simulated tunneling spectra of the polar ZnO surfaces

Abstract Scanning tunneling microscopy was used to study the geometric and electronic structure of the two polar surfaces of zinc oxide in ultra-high vacuum. Even though the topographies of the surfaces are similar, the tunneling spectra differ on each surface plane (Zn-terminated or O-terminated), differ depending on the proximity to mesas, and are affected by the adsorption of O2. Calculations of tunneling spectra allow these data to be interpreted within the framework of established models for tunneling to semiconductor surfaces. These calculations demonstrate that changes in the spectra are due to changes in the local electronic properties of the surface. For example, features in tunneling spectra recorded at the edge of mesas can be related to spatially localized electronic states in the band-gap region, and changes induced by the adsorption of O2 can be explained by a reduction in the surface charge density. Negative differential conductance (NDC) was observed and a model which uses a varying density of states combined with tip-induced band bending is presented.
Population structure, growth rates, and seasonal abundance of two Syngnathus pipefish species

Northern pipefish,Syngnathus fuscus, and dusky pipefish,Syngnathus floridae, are among the most abundant ichthyofauna components of the Chesapeake Bay, USA, eelgrass beds,Zostera marina, but population structure and many life history traits remain uncharacterized. We conducted monthly collections from May through September 2003–2005 in Chincoteague Bay, Virginia, to investigate seasonal migration and spawning, sex ratios, size at maturity, sexual dimorphism in length, and growth rates. BothS. fuscus andS. floridae spawned from May through September. Water temperature was significantly correlated withS. fuscus catches, whereasS. floridae abundance peaked after maximum water temperatures. Sex ratio data indicatedS. floridae populations are balanced, whileS. fuscus populations are strongly female-biased. Both species can quickly reach reproductive maturity, potentially within one season, becauseS. fuscus andS. floridae population growth rates average 1.0 mm d−1 and minimum standard length at maturity measures 125 and 103 mm, respectively, for females and 99 and 91 mm, respectively, for males. ForS. fuscus, females were significantly longer than conspecific males during time periods when juveniles were not rapidly maturing. Size sexual dimorphism in this species coincides with reports of extensive paternal care and supports the hypothesis that the strength of sexual selection differs in these species.
Seafloor Habitat Mapping on the Oregon Continental Margin: A Spatially Nested GIS Approach to Mapping Scale, Mapping Methods, and Accuracy Quantification

We implement a geographic information system (GIS) to map surficial geologic habitats (SGH) with varying scales at Nehalem Bank, Oregon, USA. Geologic interpretation was first used to produce a regional-scale SGH map of mega habitats. Local-scale algorithmic classification techniques were then implemented where data density and richness permitted the mapping of meso (10 m-1 km) macro scale (1–10 m) habitat features. We use a ranked-(data) density approach to assess the distribution and quality of input data for the regional SGH map. We then apply a virtual reference dataset and error matrix technique to assess the thematic accuracy of local-scale maps.
Pulsatile motion of the trabecular meshwork in healthy human subjects quantified by phase-sensitive optical coherence tomography

Aqueous leaves the anterior chamber of eye by passing through the trabecular meshwork (TM), a tissue thought to be responsible for increased outflow resistance in glaucoma. Motion assessment could permit characterization of TM biomechanical properties necessary to maintain intra-ocular pressure (IOP) within a narrow homeostatic range. In this paper, we report the first in vivo identification of TM motion in humans. We use a phase-sensitive optical coherence tomography (PhS-OCT) system with sub-nanometer sensitivity to detect and image dynamic pulse-induced TM motion. To permit quantification of TM motion and relationships we develop and apply a phase compensation algorithm permitting removal of the otherwise evitable confounding effects of bulk motion. Twenty healthy human eyes from 10 subjects are imaged. The results permit visualization of pulsatile TM motion visualization by PhS-OCT; correlation with the digital/cardiac pulse is highly significant. The correlation permits assessment of the phase lag and time delay between TM motion and the cardiac pulse. In this study, we find that the digital pulse leads the pulsatile TM motion by a mean phase of 3.53 ± 0.48 rad and a mean time of 0.5 ± 0.14 s in the fundamental frequency. A significant linear relationship is present between the TM phase lag and the heart rate (p value < 0.05). The TM phase lag is also affected by age, the relationship not quite reaching significance in the current study. PhS-OCT reveals pulse-induced motion of the TM that may provide insights into the biomechanics of the tissues involved in the regulation of IOP.
ASTER Land Surface Emissivity Database of California and Nevada

[1] Land surface temperature and emissivity (LST&E) are essential parameters for a wide range of studies undertaken at a variety of spatial scales. LST&E products are generated by a number of spaceborne sensors such as ASTER, MODIS, and AIRS at varying spatial, spectral and temporal resolutions. We have developed an approach for producing gridded, mean, seasonal ASTER LST&E Datasets at a spatial resolution of 100 m at nadir. This paper shows a mean wintertime and summertime emissivity dataset for California and Nevada, USA using all available data since mission launch (2000). Comparison of the two seasonal datasets indicates the greatest variability occurs in areas affected by snow such as the Sierra Nevada Mountains, and in agricultural regions. Comparisons of the new emissivity dataset with laboratory measurements of geologic samples show emissivity differences of less than 0.5%, while 1–3% differences were found for water and vegetation using spectra from the MODIS UCSB library.
Understanding Wi-Fi 2.0: from the economical perspective of wireless service providers [Dynamic Spectrum Management]

Wi-Fi 2.0 refers to Wi-Fi-like Internet access operating on whitespaces in the licensed spectrum using cognitive radio technology. Wi-Fi 2.0 is expected to provide better performance and larger coverage than today's Wi-Fi, thanks to the good propagation characteristics of the legacy spectrum such as TV bands. Wi-Fi 2.0 is modeled as a network consisting of an access point (called CR hotspot) and end-user terminals (CR devices) operated by a CR wireless service provider. In this article we focus on the economical perspective of Wi-Fi 2.0 and discuss various aspects in profit management of Wi-Fi 2.0 WSPs. In particular, we consider profit-maximizing optimal strategies in terms of customer admission/eviction control and inter-WSP market competition. We first show that Wi-Fi 2.0 operates on time-varying spectrum availability due to the ON-OFF channel usage of legacy users, and advocate the necessity of customer eviction control upon appearance of legacy users. We also identify two types of WSP-WSP market competition in leasing the limited spectrum resources from the licensees and in enticing end customers with a competitive price. Then we enumerate the key factors affecting the profit of collocated WSPs, such as channel leasing cost, service tariff, QoS provisioning, and coexistence with legacy services. By examining Wi-Fi 2.0 from an economic point of view, we show its commercial value in developing next-generation CR applications that benefit both legacy and CR users.
Matrix factorization in a real field

Abstract The feasibility of factorizing non-negative definite matrices with elements that are rational functions of several real variables and having real coefficients is discussed. Polynomial matrices are then considered briefly.
Residual toxicity of acaricides to Galendromus occidentalis and Phytoseiulus persimilis reproductive potential

Abstract Understanding the effects of pesticide residues on leaf surfaces through time on phytoseiid mites is important to their successful integration into augmentation and/or conservation programs. The residual toxicities of fenpyroximate (Fujimite ® ), acequinocyl (Kanemite ® ), etoxazole (Zeal ® ), spiromesifen (Oberon ® ), bifenazate (Acramite ® ) and abamectin (Agri-mek ® ) on leaflets to Galendromus occidentalis (Nesbitt) and Phytoseiulus persimilis Athias-Henriot (Acari:Phytoseiidae) were assessed 3, 6, 10, 14, 17, 24, 30 and 37 days post treatment. Impacts on mortality, fecundity and fertility were determined following 3 days of exposure to each leaf surface residue interval. Percent mortality and total effects ( E ) on adult female reproductive potential thus measured were used to assess each acaricide’s persistence. Based on mortality, fenpyroximate was considered slightly (from 5 to 15 days) persistent for both species by IOBC standards, while abamectin was also slightly persistent for P. persimilis only. The remaining acaricides would be classified as short lived (less than 5 days) for both species. Persistence classified by considering E suggest that fenpyroximate and etoxazole would be the least compatible with G. occidentalis and P. persimilis . Both were persistent (longer than 30 days). Bifenazate and spiromesifen were slightly persistent to both predators. Acequinocyl was slightly persistent to G. occidentalis , but short lived to P. persimilis . Abamectin was slightly persistent to P. persimilis , but short lived to G. occidentalis . Consideration of both direct and side effects of these acaricides will improve pesticide selection, anabling better conditions for Phytoseiid conservation and augmentation.
The role of N2 fixation in alleviating N limitation in wetland metaphyton: enzymatic, isotopic, and elemental evidence

The role of nitrogen (N2) fixation in balancing N supply to wetland metaphyton was assessed by comparing primary production with enzymatic, isotopic, and elemental correlates. Primary production, N2 fixation (acetylene reduction, AR), phosphatase activity, C:N:P ratio, and N isotopic composition of metaphyton were measured along a nutrient gradient in a freshwater marsh during May through September 2004. N2 fixation and phosphatase activity in metaphyton were negatively correlated with inorganic N and P concentrations, respectively. Although metaphyton N2 fixation demonstrated a clear spatial pattern along the nutrient gradient, N2 fixation rates varied monthly and decreased sharply in September. However, the percent contribution of N2 fixation to N uptake by metaphyton consistently decreased throughout the summer. Furthermore, the decreased contribution of N2 fixation to N uptake corresponded with an increase in metaphyton N content during the growing season. Nitrogen isotopic data suggested the sustained importance of an atmospheric N2 source through September at the most downstream (nutrient poor) site even though the percent contribution of N2 fixition to N uptake was lowest in that month. This suggests that metaphyton were efficiently accumulating and recycling fixed N2 in support of primary production. Over the course of the summer, metaphyton primary production showed a weak inverse correlation with metaphyton phosphatase activity (r 2 = 0.58). The largest residuals in this regression corresponded to the largest vartiation in metaphyton N content. When metaphyton primary production was normalized to metaphyton N content, production rates for the entire growing season were more strongly inversely correlated with metaphyton phosphatase activity (r 2 = 0.78). Results of the study suggest that N2 fixation in N poor areas may adequately supplement community N requirements in metaphyton, thereby causing limitation by other elemental resources such as P.
On the dislocation density in aluminum during Harper-Dorn creep

Abstract In research on high temperature, low stress, creep in aluminum, Lacombe and Beaujard's etchant has been used to determine dislocation densities. This work has led to the suggestions that the density is about 108 m−2 or less and independent of stress and that for Harper-Dorn creep the density must be below a critical value of about 2×109 m−2. Here, the characteristics of the etchant have been reviewed and it has been shown that they are complex and that pit densities are generally unreliable measures of dislocation populations. The purpose of this note is to point this out and to suggest that further work on dislocation populations during Harper-Dorn creep is warranted.
High-capacity pressurized continuous chromatograph

Abstract Multicomponent liquid chromatographic separations have been achieved by using a slowly rotating annular bed of sorbent material. The feed material is continuously introduced at a stationary point at the top of the bed, and eluent is allowed to flow everywhere else around the annulus. The rotation of the sorbent bed causes the separated components to appear as helical bands, each of which has a characteristic, stationary exit point; hence the separation process is truly continuous. The concept has been developed primarily on a 279-mm-diam by 0.6-m-long device with a 12.7-mm-wide annulus. The effects of annulus width and diameter have been studied using the same device with annulus widths up to 114.3 mm. With this largest width, approximately 96% of the area available within the outer cylinder is devoted to the rotating sorbent bed. Further annulus-width studies have been pursued on units with 89- and 445-mm diameters. These geometric extensions to the basic concept allow extremely large capacity i...
The Effect of Head Start on Parenting Outcomes for Children Living in Non-parental Care

We examined the effect of Head Start on parenting outcomes for children living in nonparental care, or living with someone other than biological, adoptive, or step-parent. Data came from the Head Start Impact Study, a nationally representative and randomized controlled trial of Head Start-eligible children and families. Parenting outcomes included receipt of supportive services, receipt of home visiting, parental involvement at home and at school, and frequency of spanking. Regression analyses indicated positive effects of Head Start on receipt of supportive services and home visiting, and on decreases in spanking, as well as marginal effects on greater preschool-based parent involvement (e.g., attending conferences and workshops and classroom volunteering). No effect was detected of Head Start on home-based involvement (i.e., frequency parent–child book reading and enrichment activities). These findings add to an emerging line of research suggesting that early childhood programs, such as Head Start, may be an effective and practical way of supporting non-parental families with preschool-aged children. Findings also identify potential areas for improvement in supporting non-parental families and the need for more research to further understand the role of early care and education in the lives of nonparental families.
Thermodynamic analysis and phase equilibria calculations for the In-Sb and Ga—Sb systems

A quasi sub-subregular solution model is used to describe the thermodynamic properties of the liquid phase in the In-Sb and Ga-Sb systems. The In-Sb and Ga-Sb phase diagrams are, then, calculated from the optimized model parameters for the liquid phases and the Gibbs energies of formation of the InSb and GaSb phases obtained from the literature. The calculated phase diagrams and thermodynamic properties are in reasonable agreement with the experimental data. Our calculations are also compared with those reported in the literature using associated solution models for the liquid phases.
Relative Deprivation and Palestinian Suicide Bombings

This paper applies the concept of relative deprivation to the study of Palestinian suicide bombings. While earlier work by Krueger and Maleckova (2003) indicates that the absolute well-being of those who support terrorism is higher than the general population in the West Bank and Gaza Strip, it is not clear if changes in the relative well-being of Palestinians could have influenced suicide bombings. This paper uses three reference groups, namely earlier generations of youth, as well as Israelis and Palestinians residing in different areas, to understand whether relative deprivation helps explain the phenomenon of suicide bombings. This paper finds some support for relative deprivation influencing the rate and timing of suicide bombings.