cssi/SciSciGPT-SciSciNet huggingface dataset:
Improving transport layer performance by using A novel medium access control protocol with fast collision resolution in wireless LANs

Development of efficient medium access control (MAC) protocols is a fundamental research issue in high-speed wireless local area networks (LANs). In this paper, we focus on the performance improvement both of MAC layer and transport layer by using a novel medium access control protocol in high-speed wireless LANs which use carrier sense multiple access/collision avoidance(CSMA/CA). We propose an efficient distributed contention-based MAC protocol, namely, the Fast Collision Resolution (FCR) algorithm, and show that the proposed FCR algorithm provides high throughput and low latency while improving the fairness performance for serving users in wireless LANs. The performance of the FCR algorithm is compared with that of the IEEE 802.11 MAC algorithm via extensive simulation studies both in MAC layer and transport layer. The results show that the FCR algorithm achieves a significantly higher efficiency than the IEEE 802.11 MAC algorithm and is well suited for transport layer protocols such as transmission control protocol (TCP) and user datagram protocol (UDP).
The effects of ethanol on the structural stability of acetylcholine receptor and the activity of various molecular forms of acetylcholinesterase.

Abstract The actions of ethanol on the structural stability of acetylcholine receptor (AchR)-enriched membrane vesicles and the activity of various molecular forms of acetylcholinesterase (AchE) were investigated, using the receptor and the enzyme isolated from the electric organ of Torpedo californica . In the presence of ethanol up to 200 mM, the thermogram of AchR-enriched membranes exhibited no significant decrease in the temperature ( t d ) of receptor transition at 57°C, but a decrease in the enthalpy change ( ΔH d ) indicated a slight ethanol-induced structural perturbation. The presence of 12.5 nmol α-bungarotoxin also caused a decrease in ΔH d . A complete loss of the receptor transition was observed at a higher concentration 500 nmol of α-bungarotoxin and no recovery of the transition was found with the addition of 200 mM ethanol. The results suggested a noncompetitive interaction of ethanol with the receptor. In the presence of 200–1000 mM ethanol, the activity of two soluble forms of AchE, a higher (117 S) aggregate and a lower (10 S) aggregate was not significantly affected. Comparing the activity of these two aggregates over a wide concentration range of ethanol (200–2000 mM) revealed no obvious difference in the level of ethanol effect between them. However, after removal of ethanol, the higher aggregate form of AchE exhibited a greater recoverability of the activity, suggesting a possible slightly greater structure-functional stability for it. Studies of soluble AchE and membrane-bound AchE showed that the presence of 200 or 600 mM ethanol caused a greater level of inhibition in membrane-bound enzyme than in soluble enzyme, possible due to a disruption of protein-lipid interaction needed to maintain the conformation of membrane-bound AchE. Interestingly, at a much higher concentration of ethanol (2.0 M), membrane-bound AchE became more resistant to ethanol than did the soluble forms of AchE. In this case, the effective concentration of ethanol felt by the enzyme was expected to be less for membrane-bound AchE, owing to ethanol's solubility in lipids.
Rapid, permanent, loss of memory for absolute intensity of taste and smell

Memory formation for the absolute intensity of taste and smell was investigated in a series of experiments. In Experiment 1, 336 subjects tasted 10 ml of 15% sucrose and were asked to remember the strength of the solution. They were retested with 5%, 10%, 15%, or 20% sucrose, at one of four delay intervals (1, 5, or 15 min, or 72 h). They compared the second stimulus with the first stimulus and reported whether the second was “less sweet, ” “the same, ” or “sweeter. ” Subjects reliably reported that 5% sucrose was less sweet and that 20% sucrose was sweeter. However, when the second stimulus was 15% sucrose (i.e., was equal to the standard), approximately 60% of the subjects reported that it was sweeter, regardless of the delay interval between the two stimuli. About 2/3 of those tasting 10% sucrose reported that it was as sweet as or sweeter than the 15% standard. A similar finding from a procedure using magnitude estimation was reported in Experiment 2. The same pattern of results was also found for an olfactory memory test (Experiment 3). When asked to match either a 1.33- or a 5.0-ppm pyridine olfactory stimulus, subjects consistently picked a concentration weaker than the standard. Apparently, olfactory and taste stimuli are remembered as being substantially weaker as soon as the memory for these stimuli can be tested. A memory model that posits a sensory store within which a taste or smell stimulus of a given intensity rapidly fades to a lower level of intensity is suggested. The new memory is then relatively unchanged for at least 3 days.
Are we selecting the right patients for treatment of localized prostate cancer? Results of an actuarial analysis

Abstract Ojectives. To determine our accuracy in selecting patients with at least a 10-year life expectancy for aggressive treatment of localized prostate cancer. Methods. The medical records of 261 consecutive patients who underwent radical retropubic prostatectomy were submitted to the actuarial division of American General Life and Accident Insurance Company (AGLA) for estimation of life expectancy, excluding the diagnosis of prostate cancer. Survival curves were generated from predicted individual survivals. In patients with less than a 10-year life expectancy, AGLA provided us with the basis for assigning suboptimal survival rates. Results. The mean life expectancy for the group was 15.2 years. Two hundred ten men (80%) were projected to have a life expectancy of more than 10 years, including 27 of 55 (49%) and 4 of 8 (50%) men who were older than or equal to 70 and 75 years of age, respectively. Coronary artery disease and diabetes mellitus were the most common coexisting medical conditions that adversely affected risk as single disease entities. Conclusions. Although clinicians do not estimate life expectancy with the scientific exactitude of an actuary, the ability to assess the patient in person and assimilate pertinent medical information in a less rigid format yields similar results. Selection of men for definitive treatment of localized prostate cancer should be based on the inherent aggressiveness of the disease and the health of the individual and should not be limited by specific age cutoffs. Populations of men undergoing radical prostatectomy are younger and healthier than those in reported series of watchful waiting for prostate cancer.
Responses of tree populations to climatic change

The influence of climate on the population dynamics of trees must be inferred from indirect sources of information because the long lifespans of trees preclude direct observation of population growth and decline. Important insights about these processes come from 1) observations of the life histories and ecologies of trees in contemporary forests, 2) evidence of recent treeline movements in remote areas unaffected by human disturbance, and 3) results of experiments performed on forest simulation models. Each line of evidence indicates that tree population responses are influenced by many factors: including lifespans, seed productivity and dispersibility, phenotypic plasticity, genetic variability, competition, and disturbance. Some population characteristics should allow rapid changes in population sizes, while others should confer stability in times of environmental fluctuation. Interactions between controlling factors should result in a wide array of possible responses to climatic change. Interpretations of late-Quaternary forest dynamics must be based on an understanding of the biological processes involved in population responses to environmental variations.
Taking the temperature of slabs

Subduction zones are places where slabs of ocean crust dive deep into the Earth's mantle — as, for instance, beneath Japan. New studies provide insight into the influence that a slab's thermal structure, cold or warm, may have on the seismic and volcanic activity associated with subduction.
Alcohol Dependence in Adult Children of Alcoholics: Longitudinal Evidence of Early Risk:

This study investigates familial alcoholism effects and the comparative probability of risk for alcohol dependence in adult children of alcoholics (ACAs) with a control group of non-ACAs. A cohort of 12,686 young adults from the National Longitudinal Survey of Youth (NLSY) is examined over a five-year period and conventional and lineal intergenerational models of alcoholism transmission are assessed. The results of multivariate logistic regression analyses indicate that the risk is relatively greater for male ACAs; sons of alcoholics drink significantly more heavily, experience problems earlier, and develop alcohol dependence more extensively than female ACAs or non-ACAs of either gender. The extent of dependence found in subjects with a lineal history of alcoholism on the father's side of the family, as well as heavy drinking, cigarette smoking and drinking onset in adolescence should be considered as critical predisposing factors of high risk for dependence at later ages. These observations corroborate clinical studies and support a growing body of biopsychosocial research literature.
The role of the human thalamus in language and memory: evidence from electrophysiological studies

The data reviewed here indicate that electrical stimulation of the dominant ventrolateral thalamus can produce deficits in language processing that are not seen after similar stimulation of the nondominant ventrolateral thalamus. The nature of the language deficit produced varies, depending upon the rostrocaudal location of the stimulation site. Stimulation of the anterior left ventrolateral thalamus in right-handed patients resulted in production of a repeated erroneous word, stimulation of the medial ventrolateral thalamus evoked perseveration, and stimulation of the posterior ventrolateral thalamus and anterior pulvinar resulted in misnaming and omissions. Additional studies have examined the effect of electrical thalamic stimulation on verbal and nonverbal short-term memory. Left (but not right) ventrolateral thalamic stimulation during verbal memory input greatly decreased subsequent recall errors, while stimulation during verbal memory retrieval increased recall errors. This finding contrasted with those obtained from studies on nonverbal memory, in which right ventrolateral stimulation during memory input decreased recall errors, while left thalamic stimulation at the same stage increased recall errors. Left pulvinar stimulation disrupted verbal memory processing, while right pulvinar stimulation disrupted nonverbal memory processing. Limited evidence suggests that the effects of thalamic electrical stimulation on verbal memory may persist for several days after the stimulation has ended. The lateralization of thalamic functions also affects the motoric aspects of speech production. Left (but not right) ventrolateral thalamic stimulation disrupted speech articulation and increased the expiratory phase of respiration. The fact that these motor effects were evoked from the same general area of the thalamus that produced the language deficits discussed above raises the possibility that the thalamus is involved in coordinating the cognitive and motoric aspects of language production. A model of thalamic function is discussed in which defined regions of the thalamus operate as a "specific alerting response," increasing the input to memory of category-specific material while simultaneously inhibiting retrieval from memory.
Factors affecting formation of cluster roots in Myrica gale seedlings in water culture

The effect of nutrient deficiency, aeration, phosphorus supply, and nitrogen source on the formation of cluster (proteoid) roots was examined in Myrica gale seedlings growing in water culture. Only the omission of phosphorus resulted in the formation of significant numbers to cluster roots when plants were grown in a number of 1/4 strength Hoagland's solutions, each lacking one mineral nutrient. Aeration shortened the time required for cluster root formation and increased the percentage of plants forming cluster roots. The proportion of the root system comprised of cluster roots decreased as the phosphorus concentration in the solution increased and no cluster roots formed in solutions containing 8 mg P/L. Phosphorus supply also affected total plant biomass, proportion of biomass comprising nitrogen-fixing nodules, shoot:root ratio, phosphorus concentration in the leaves and phosphorus content of the plants. The plants showed luxury consumption of phosphorus and were able to produce large amounts of biomass utilizing only stored phosphorus. Nitrogen source also affected cluster root formation. Urea-fed plants produced cluster roots more quickly and devoted a substantially larger proportion of root growth to cluster roots than did nitrate-fed plants. The longest cluster root axes were produced in nitrate-fed plants supplied with no phosphorus and the shortest were in urea-fed plants at 4 mg P L−1. Four methods for expressing the extent of cluster root formation were examined and it was concluded that cluster roots as a proportion of total fine root dry weight is preferable in many cases. Formation of cluster roots in response to phosphorus deficiency coupled with previously demonstrated traits allows Myrica gale to adapt to a wide range of soil conditions.
Identification and sequence analysis of the genes encoding a polyketide synthase required for pyoluteorin biosynthesis in Pseudomonas fluorescens Pf-5.

Abstract Pyoluteorin is a chlorinated antifungal metabolite of mixed polyketide/amino-acid origin produced by certain strains of Pseudomonas spp., including the soil bacterium Pseudomonas fluorescens Pf-5. Sequence analysis of a gene cluster required for pyoluteorin biosynthesis by Pf-5 (Kraus, J., Loper, J., 1995. Appl. Environ. Microbiol. 61, 849–854) has identified two genes whose deduced peptide sequences exhibit characteristics of both fungal and bacterial Type I polyketide synthases (PKSs). The pyoluteorin PKS does not contain a loading domain that is typically present in bacterial Type I PKSs. Furthermore, this PKS possesses an acyltransferase domain that does not contain the conserved residues surrounding the active-site motif typically found in domains of similar function. Based on the organization of the functional domains within the pyoluteorin PKS, we propose a biosynthetic pathway analogous to non-aromatic polyketide biosynthesis within the Actinomycete bacteria that is responsible for the formation of the resorcinol moiety of pyoluteorin.
Displacement chromatography on packed capillary columns

Abstract A displacement chromatographic microsystem was constructed using packed fused-silica capillary columns and commercially available micro-liquid chromatographic elements. The feasibility of displacement chromatographic separations on the microscale was demonstrated with a reversed-phase system using alkylphenols as test solutes. Successful separations were achieved even with samples as large as 0.1 mg on 200 μm I.D. capillary columns packed with 5-μm particles. UV detection of the separated bands was facile, as sample concentrations in the detector cell reached millimolar levels. Separation conditions were optimized to allow the direct injection of up to 10-μl sample volumes, equivalent to half of the total column volume, without deterioration of the quality of the separation.
Complexity in Science and Technology Policy... Symptoms or Disease? [Commentary]

For many years I have questioned how democracies decide, enact, and carry out Science and Technology (S&T) Policy. Around the world, most Congressional and parliamentary leaders tend to be lawyers who have no formal education in S&T Yet the decisions that these leaders make affect among other things, our education, our healthcare, and our national defense. It is in our best interest then to provide lawmakers with the best information available so that good decisions can be made. The reality is that most of the time events that happen within or outside a country can contribute to major errors in how we act. In other words we (may) think we know what we are trying to correct, when in reality the problem was never well defined, and therefore the solution that we seek may be for the wrong question. We encounter problems that on the surface seem like discrete pieces and where if a single piece breaks it can be replaced by a new part of the same type, but then we find that we have encountered a complex system that is dynamic, and where the solution also changes with time.
Critical role of CFTR-dependent lipid rafts in cigarette smoke-induced lung epithelial injury.

Apoptosis of lung epithelial and endothelial cells by exposure to cigarette smoke (CS) severely damages the lung tissue, leading to the pathogenesis of emphysema, but the underlying mechanisms are ...
Separation and characterization of the two high density lipoproteins of egg yolk, α- and β-lipovitellin☆

Abstract 1. 1. The electrophoretic components of lipovitellin (α- and β-) have been separated from each other, and from the livetins and phosvitin in the high density fraction of egg yolk, by chromatography on hydroxyapatite columns. 2. 2. Both α- and β-lipovitellin have the same lipid content, nitrogen content, amino acid composition, and molecular weight (4.0 · 10 5 ). They differ in their protein phosphorus content, electrophoretic mobility, absorption on hydroxyapatite, ultracentrifugal behaviour in alkaline media, and in solubility.
The fly can discriminate movement at signal/noise ratios as low as one-eighth.

Abstract Measurements are made of the optomotor response of tethered, flying flies to stimuli that contain a signal component and a noise component, displayed on a computer-driven CRT. The signal consists of a moving grating; the noise consists of variations of optical intensity that are random in space and time. Threshold signal-to-noise ratio (S/N) for the optomotor response is about 1/8. Discrimination by the fly's visual system rivals and sometimes surpasses that of the human. Results are analyzed in terms of the Reichardt correlation model of movement detection to highlight two mechanisms that could contribute to noise rejection: (a) movement detection via multiplicative processing, (b) spatial summation of responses of small-field movement-detector units by a large-field optomotor neuron. Movement discrimination at low S/N could have adaptive value at low light levels, when quantum noise is appreciable.
Early development of Rhizobium -induced root nodules of Parasponia rigida . I. Infection and early nodule initiation

The first of two major steps in the infection process in roots ofParasponia rigida (Ulmaceae) following inoculation byRhizobium strain RP501 involves the invasion ofRhizobium into the intercellular space system of the root cortex. The earliest sign of root nodule initiation is the presence of clumps of multicellular root hairs (MCRH), a response apparently unique amongRhizobium-root associations. At the same time or shortly after MCRH are first visible, cell divisions are initiated in the outer root cortex of the host plant, always subjacent to the MCRH. No infection threads were observed in root hairs or cortical cells in early stages. Rhizobial entry through the epidermis and into the root cortex was shown to occur via intercellular invasion at the bases of MCRH. The second major step in the infection process is the actual infectionper se of host cells by the rhizobia and formation of typical intracellular infection threads with host cell accommodation. This infection step is probably the beginning of the truly symbiotic relationship in these nodules. Rhizobial invasion and infection are accompanied by host cortical cell divisions which result in a callus-like mass of cortical cells. In addition to infection thread formation in some of these host cortical cells, another type of rhizobial proliferation was observed in which large accumulations of rhizobia in intercellular spaces are associated with host cell wall distortion, deposition of electron-dense material in the walls, and occasional deleterious effects on host cell cytoplasm.
Effects of cingulate cortical lesions on avoidance learning and training-induced unit activity in rabbits

This study extends an ongoing analysis of the neural mediation of discriminative avoidance learning in rabbits. Electrolytic lesions encompassing anterior and posterior cingulate cortex (area 24 and 29) or ibotenic acid lesions in area 24 only were made prior to avoidance conditioning wherein rabbits learned to step in response to a tone conditional stimulus (CS+) in order to avoid a brief, response-terminated 1.5 mA. foot-shock unconditional stimulus (US). The US was presented 5 s after CS+ onset, in the absence of a prior stepping response. The rabbits also learned to ignore a different tone (CS-) not followed by the US. Multi-unit activity of the caudate and medial dorsal (MD) thalamic nuclei, projection targets of the cingulate cortex, was recorded during learning in all rabbits. Activity was also recorded in area 29 in the rabbits with area 24 lesions. Learning in rabbits with combined lesions was severely impaired and it was moderately retarded after lesions in area 24. MD thalamic and caudate training-induced neuronal discharge increments elicited by the CS+ were enhanced in rabbits with lesions, suggesting a suppressive influence of cingulate cortical projections on this activity. Early-, but not late-developing training-induced unit activity in area 29c/d was absent in rabbits with area 24 lesions, indicating that area 24 is a source of early-developing area 29 plasticity. These results are consistent with hypotheses of a theoretical working model, stating that: a) learning depends on the integrity of two functional systems, a mnemonic recency system comprised by circuitry involving area 24 and the MD nucleus and a mnemonic primacy system comprised by circuitry involving area 29 and the anterior thalamic nuclei; b) corticothalamic information flow in these systems suppresses thalamic CS elicited activity in trained rabbits; c) corticostriatal information flow is involved in avoidance response initiation. An absence of rhythmic theta-like neuronal bursts in area 29b in rabbits with area 24 lesions is attributable to passing fiber damage.
Cationic polymerization of 4-methyl-1,3-dioxene-4 and copolymerization with tetrahydrofuran

A new monomer, 4-methyl-1,3-dioxene-4 was synthesized from allyl chloride and paraformaldehyde. The monomer was polymerized at room temperature or −78°C. by boron trifluoride etherate catalyst, and the structure of the obtained polymer was determined by infrared, nuclear magnetic resonance spectra, and chemical analysis. It was ascertained that the polymerization process proceeded through a ring-opening mechanism at the dioxane ring. In the presence of tetrahydrofuran, the polymerization of 4-methyl-1–1,3-dioxene-4 led to copolymer. The mechanism of the copolymerization is described in detail.
Hegel, Humour, and the Ends of Art

Art plays a fundamental role in Hegel's mature systematic philosophy, one of three principal forms of what Hegel terms ‘absolute spirit’, that is, a primary way in which humans cognize their nature and its role in the world (HW 10: 366-67). Notwithstanding this, Hegel's philosophy of art has received less attention than have his philosophy of religion, political philosophy, or philosophy of history, all of which were mainstays in the debates between the rival schools of Hegelianism directly after Hegel's death, and each of which exercised considerable authority in the nineteenth and twentieth centuries. There were no Right or Left Hegelians on questions of art. Of course, this is not to say that Hegel's philosophy of history and conception of dialectical reason did not have decisive impact on the founding of systematic art history and on the philosophy of art in the humanistic Marxism of Lukacs, Adorno and Marcuse, but his specific views on aesthetics and the nature and history of the various arts were much less influential. If one were to broaden the scope of influence to include artists, Hegel is hardly worth mentioning next to figures like Schopenhauer and Nietzsche.Do Hegel's specific views on art have purchase nowadays? One set of doctrines has received a good deal of attention, at least among philosophers of art: Hegel's claim that art has ‘ended’. Much commentary focuses on Hegel's contentions that (A) the art of Attic Greece was the primary way for that culture to experience their form of life as binding, and that (B) art after a point in that culture can never play that role again, at least not progressively.
Assessing the transportation consequences of land use transformation in urban China

Abstract This paper assesses the accessibility and mobility consequences of urban land transformation in expanding Chinese cities. It defines transportation–land use connections in China's context and analyzes the accessibility and mobility uncertainties associated with current urban development themes, including the formulation of CBD, the development of satellite communities, and the evolution toward multi-center layout. This article points out that appropriate accessibility and mobility objectives are not well considered in land development, and current development themes tend to lengthen trips and lead to increased congestion in the context of growth and motorization. A strong national leadership is needed to help city governments integrate accessibility and mobility objectives into urban development.
Globalization, the Class Relation and Democracy

to the detriment of those thought to be advantaged by democracy: i.e., that vast majority that obtains its living not from returns on property in their various forms but from wages. Globalization, it is asserted, has made it harder for the vast majority of the population to impose their will regarding redistribution through the democratic process. Capital has gained in power relative to labor. The most obvious way in which this is supposed to have happened is through the ability that capital has acquired to shift its money around. This, it is argued, has allowed it to elude, or resist in situ through the threat of relocation, the demands of workers for enhanced wages, improved benefits and the like. Rather workers in different countries
Elastic-plastic torsion as a problem in non-linear programming

Abstract For a simply connected region, it is shown that the problem of determining the elastic-plastic stress function is equivalent to that of minimizing the complementary energy subject to the inequality constraints required by the yield condition. A method is proposed for approximating this minimum in which the cross section is approximated by a finite number of triangles and a linear stress function is assumed for each triangle. This approximate problem is then solved by means of a recently available computer program for solving nonlinear constrained minimization problems.
The hazards of thinking about moral hazard

Some scholars have argued that expectations of humanitarian military intervention might actually increase the incidence of intrastate violence, and have invoked the concept of moral hazard from the economics literature on insurance and government regulation to explain why. However, the term ‘moral hazard’ is no substitute for a careful analysis of how expectations of intervention might influence the decisions made by participants in intrastate conflicts. I argue that an analysis of those decisions implies that the prospect of intervention might indeed make violence more likely, but for reasons that have little to do with what is commonly called moral hazard.
Aligning coordinate frames in multi-robot systems with relative sensing information

In this paper, we present both centralized and distributed algorithms for aligning coordinate frames in multirobot systems based on inter-robot relative position measurements. Robot orientations are not measured, but are computed by our algorithms. Our algorithms are robust to measurement error and are useful in applications where a group of robots need to establish a common coordinate frame based on relative sensing information. The problem of establishing a common coordinate frame is formulated in a least squares error framework minimizing the total inconsistency of the measurements. We assume that robots that can sense each other can also communicate with each other. In this paper, our key contribution is a novel asynchronous distributed algorithm for multi-robot coordinate frame alignment that does not make any assumptions about the sensor noise model. After minimizing the least squares error (LSE) objective for coordinate frame alignment of two robots, we develop a novel algorithm that outperforms state-of-the-art centralized optimization algorithms for minimizing the LSE objective. Furthermore, we prove that for multi-robot systems (a) with redundant noiseless relative sensing information, we will achieve the globally optimal solution (this is non-trivial because the LSE objective is nonconvex for our problem), (b) with noisy information but no redundant sensing (e.g. sensing graph has a tree topology), our algorithm will optimally minimize the LSE objective. We also present preliminary results of the real-world performance of our algorithm on TurtleBots equipped with Kinect sensors.
Critical factors in information system development for a flexible manufacturing system

Abstract The successful implementation of a flexible manufacturing system (FMS) is highly dependent upon the design and development of the system for information flow and control. The literature indicates that information systems are the primary source of problems in an FMS, but are the least studied subsystem within an FMS. Based upon the case study of a successful implementation of a fully automated FMS, six critical success factors (CSFs) were identified for information system development within an FMS. These CSFs point to the importance of four issues: (1) simplification and standardization, (2) communication, (3) team building, and (4) resource allocation. The FMS development process is described, and the six CSFs are compared to related findings in the literature on FMS implementation, project management, software design and factory automation. The paper concludes by stating the implications for management, system design and future research.
Characterizing bias matroids

Abstract del Greco, J.G., Characterizing bias matroids, Discrete Mathematics 103 (1992) 153–159. In this paper, a set of necessary and sufficient conditions for a matroid to be the bias matroid of a given biased graph is obtained. These conditions are reminiscent of a 1981 result of Seymour that characterized when a matroid is the polygon matroid of a graph.
Issues and Recent Advances in Soil Respiration

The terrestrial carbon cycle is intrinsically tied to climate, hydrology, nutrient cycles, and the production of biomass through photosynthesis. Over two-thirds of terrestrial carbon is stored below ground in soils, and a significant amount of atmospheric CO2 is processed by soils every year.Thus, soil respiration is a key process that underlies our understanding of the carbon cycle. Soil CO2 fluxes are the sum of root (autotrophic) and microbial (heterotrophic) respiration. Several factors contribute to soil respiration, including photosynthetic supply to roots, substrate quality and availability, temperature, and moisture.
Discrimination of aerial deposition sources of polychlorinated dibenzo-p-dioxin and polychlorinated dibenzofuran downwind from a pulp mill near Ketchikan, Alaska.

Drinking water is supplied by individual roof−catchment systems for homes and businesses near a dissolving sulfite pulp mill (now closed) located just north of Ketchikan in southeast Alaska. This study was conducted to determine if polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDDs/Fs) found in the sediments of the roof−catchment cisterns resulted from historical deposition of stack emissions from the pulp mill's multi-fuel power boilers. Fly ash from the power boilers had maximum total PCDD/F concentrations of 3.08 × 105−3.10 × 106 ng/kg, which resulted from combustion of bleach plant wastewater sludge and saltwater-soaked wood waste. Cistern sediments had maximum total PCDD/F concentrations of 7.71 × 104 ng/kg. Potential sources of PCDDs/Fs in the cistern sediments were considered to be automobile exhaust, heating oil combustion, and private trash burning as well as pulp mill boiler emissions. Discriminant analysis was used to analyze differences between profiles of tetra through...
A unified statistical rain-attenuation model for communication link fade predictions and optimal stochastic fade control design using a location-dependent rain-statistics database

A static and dynamic rain-attenuation model is presented which describes the statistics of attenuation on an arbitrarily specified satellite link for any location for which there are long-term rainfall statistics. The model may be used in the design of the optimal stochastic control algorithms to mitigate the effects of attenuation and maintain link reliability. A rain-statistics data base is compiled, which makes it possible to apply the model to any location in the continental U.S. with a resolution of 0-5 degrees in latitude and longitude. The model predictions are compared with experimental observations, showing good agreement.
Funny Women: Social Change and Audience Response to Female Comedians

It is generally acknowledged that gender stereotypes have hindered the development and recognition of women's humor. In the face of rapid expansion of opportunities for women in the comedy field, p...
Operation or Indomethacin for the Premature Ductus

Abstract Indomethacin constricts the patent ductus arteriosus in approximately 70% of premature infants, but temporarily inhibits synthesis of all prostaglandins. Early toxicity of indomethacin is not prohibitive, but the possibility of Iate neurological deficits is raised by results of laboratory experiments. As yet, no late toxic effects of indomethacin have been observed. However, this possibility and the low morbidity (
Emergencies in and out of the dental office: a pilot study in the State of Texas

A survey conducted in the State of Texas indicated that dentists need more instruction on the treatment of emergencies in and out of the dental office.
Dispersion Cancellation and Precise Measurement with Quantum Interferometry

We demonstrate a technique allowing for simultaneous even and odd-order spectral dispersion cancellation in a single experiment. We discuss advantages quantum interference offers for ultra-precise measurement in telecommunication.
Modulation of glucocorticoid receptor function by protein kinase A

Protein kinase A (PKA) has been shown to modulate the pattern of gene expression via transcription factors such as cAMP response element binding protein. However, in F9 embryonal carcinoma cells which lack endogenous functional cAMP response element binding protein, we have found that PKA is still able to control gene transcription through the glucocorticoid receptor (GR) by up-regulating its hormone-dependent trans-activation. Dose-response analysis indicates that PKA does not alter the ligand binding affinity of GR. PKA seems to act through the DNA binding domain of GR, since GR mutants which lack either the amino-terminal or the ligand binding domain are still able to be up-regulated by PKA. In support of this proposal, we demonstrate that PKA can enhance the DNA binding activity of GR. Our results suggest a novel mechanism by which PKA modulates the steroid sensitivity of a target cell by enhancing the DNA binding activity of GR for its cognate hormone response elements.
Fluorescent dye penetrants applied to rock fractures

Abstract Under ultraviolet illumination, non-particulate fluorescent dye penetrants clearly mark the surface traces of fractures in minerals and rocks. The use of fluorescent penetrants has been effective in studying the development of fractures in rock specimens deformed in the laboratory. This paper outlines the fluorescent penetrant method as used in a series of experiments concerned with studying the generation and propagation of extension fractures in flexed specimens of a porphyritic granite. Photographs taken before and after deformation are presented and from these the pattern of fracture development can be studied. Fracture traces down to 0·05 mm wide have been observed and photographed. This technique is applicable to other rock types in a variety of laboratory situations and its possible use in in situ studies is now being investigated.
Impact of Error in Pavement Condition Data on the Output of Network-Level Pavement Management Systems

The quality of pavement condition data is important not only in assessing the current condition of the network but also in predicting its future condition and planning future maintenance and rehabilitation (M&R) activities. This paper provides a quantitative assessment of the impact of error magnitude and type (systematic and random) in pavement condition data on the accuracy of pavement management system (PMS) outputs (i.e., forecasted needed budget and M&R activities in a multiyear planning period). The process developed to simulate the propagation of pavement condition errors to PMS output consisted of five components: condition data generation, error perturbation, condition prediction, M&R prioritization, and output generation. This process was applied to the 2011 pavement condition data set of the Bryan District of the Texas Department of Transportation. In 2011, the roadway network of the Bryan District consisted of approximately 3,200 roadbed centerline miles. The study results show that both syste...
Influence of nanotube characteristics on electrical and thermal properties of MWCNT/polyamide 6,6 composites prepared by melt mixing

Abstract Differential scanning calorimetry (DSC), X-ray diffraction, dynamic mechanical analysis (DMA) and electrical conductivity measurements were performed on multiwalled carbon nanotube/polyamide 6,6 composites with four different types of well-characterized tubes manufactured using fixed-bed catalytic processes. The tubes differed in diameter, number of walls and surface chemistry. Except for one very poorly formed set of tubes, there were not large differences in behavior with respect to modulus, maximum electrical conductivity and percolation threshold; none of which differed by more than a factor of 2 for the three types of tubes. However, the shape of the percolation region was very different for the larger diameter tubes in that the percolation region occurred over a much wider concentration. Glass transition and crystallization/melting characteristics also showed very small differences between the three types of tubes. One unique observation made in this work was that the glass transition temperature (Tg) showed a qualitatively different behavior depending on what was used to measure the transition: DSC indicated an increase in Tg with added nanotubes while DMA showed a decrease in Tg. Other than the difference being related to how the Tg was measured, it is not clear what caused the qualitatively different behavior.
Influences on Students’ Decisions to Report Cheating: A Laboratory Experiment

We use a controlled laboratory experiment design to test rational choice theory on student whistleblowing. We examine reporting costs by comparing actual reporting behavior under anonymous and non-anonymous reporting channels. Reporting benefits are explored by considering the influence on reporting of group versus individual reward systems. We find that the type of reporting channel does not significantly influence student reporting behavior. Rewarding students based on group test scores results in significantly higher reporting rates compared to a system rewarding students based on individual test scores. Our laboratory research design allows for the measurement of actual reporting. The high reporting rates in this study emphasize the importance of clearly stating what is considered to be unethical behavior and directly asking students about their ethical environment.
Mechanistic Studies of Formate Oxidation on Platinum in Alkaline Medium

The electro-oxidation of formate (HCOO–) on polycrystalline Pt in highly basic medium (pH = 14) has been investigated by cyclic voltammetry, differential electrochemical mass spectrometry, potential step-linear sweep voltammetry, and adsorbate stripping experiments. Low oxidation currents were observed for HCOO– oxidation indicating that HCOO– is only weakly active under these conditions. The activity of HCOO– is confined to low potentials (0.2 V < E < 0.7 V vs RHE). Our results suggest a dual pathway mechanism for HCOO– oxidation, analogous to HCOOH oxidation in acid. In the case of HCOO– oxidation, the direct and indirect pathway analogues are referred to as the primary and secondary pathways, respectively. Formation of COads from HCOO– was observed to be slow. We also find that oxidation of COads (the secondary pathway) is strongly coupled to the oxidation of HCOO– through the primary pathway. Moreover, the oxidation of COads did not appreciably enhance HCOO– oxidation through the primary pathway, sign...
Microcomputer based algorithms for large scale shortest path problems

Abstract This paper reports on the implementation and computational testing in the microcomputer environment of several versions of a threshold-based in-core/out-of-core shortest path algorithm for finding the shortest path from one node to all other nodes in a network. These variants were compared to the best in-core/out-of-core label-correcting code, C5V7, developed in the 1970's. All codes were written in Pascal and tested on an 8088 microprocessor-based computer with a hard disk unit (IBM PC/XT) under the MS-DOS operating system. The results of the empirical study on a diverse set of medium and large-scale random and city transit grid networks provide new insights for the design of in-core/out-of-core shortest path algorithms and demonstrate the remarkable capability of a threshold-based algorithm to be fine tuned to a particular problem topology, processing environment, or computer configuration. In addition these results demonstrate the feasibility and computational tractability of solving large scale shortest path problems with microcomputers. The best approach solved a variety of problems ranging in size up to 15,000 nodes and 600,000 arcs in 10 minutes or less of wall clock time.
Nonbanking Performance of Bank Holding Companies: An Update from 1986–1990

There is an ongoing controversy over whether or not to extend commercial banks' nonbanking powers. Although the Glass‐Steagall Act of 1933 and the McFadden‐Pepper Act of 1927 restrict commercial banks' activities, the technological and financial innovations of the last several years have raised new questions. Whether banks should be allowed to undertake nonbanking activities? How profitable are these businesses? Whether banks will gain monopolistic powers? Will they increase FDIC's liabilities? And several other related questions. This study looks at the nonbanking activities of bank holding companies using a relatively new data source, i.e. FR‐Y11AS reports for the years 1989 and 1990. The performance of nonbanking subsidiaries is then compared with that of commercial banks and bank holding companies. Some meaningful inferences are drawn on issues such as market concentration, profitability, capitalization, and level of problem‐loans of nonbanking and banking subsidiaries, as well as, consolidated bank holding companies. Results from two prior studies are further utilized to look for possible trends. Since these studies have used the same data source (FR‐Y11Q and FR‐ Yl1AS) for the years 1986 through 1988, this facilitates a trend analysis over a five year period 1986–90. The main conclusions are that the BHC's nonbanking activities are heavily concentrated among the top five or ten firms within each activity. However, both the number of firms as well as total assets held in most nonbanking subsidiaries have declined over the five year period. Activities considered traditional, e.g. commercial and consumer finance and mortgage banking have suffered significant losses in terms of total assets and number of firms. Some interesting conclusions can be drawn from these results. First, due to the growing liberalization in interstate banking laws, BHCs can now carry on these activities in their bank subsidiaries and do not have to acquire a nonbanking subsidiary in order to capture business across state lines. Second, the glass walls separating banking from commerce may be cracking. Several states have started allowing banks to carry out some of the nonbanking activities, hence, considerably neutralizing the Glass‐Steagall Act. Insurance agencies and underwriting business of BHCs show the most significant growth over the five years, 1986–1990. Securities brokerage has held constant. Another finding is that the return on equity (ROE) for nonbanking firms has been lower than both the banking firms as well as the BHCs. However, this is mainly due to the relatively low equity capital levels for banks and BHCs. The nonbanking subsidiaries show fairly stable and relatively high capital ratios. Finally, for most part, nonbanking subsidiaries have a higher rate of problem‐loans.
Treefall gap size effects on above‐ and below‐ground processes in a tropical wet forest

1 We examined the effects of variation in gap size on above- and below-ground light and nutrient processes in a tropical wet forest in Costa Rica. 2 Trees were felled to create canopy openings ranging in size from 65 to 611 m2. Following treefall, we measured initial litter mass in the crown zone of six gaps. During the subsequent year, we measured litter decomposition rate and light levels as well as NH4-N, NO3-N and PO4-P levels in surface soils, soil moisture and fine root mass. We also measured growth rates of fertilized and non-fertilized plants of four species of Miconia (Melastomataceae) to assess nutrient limitation to plant growth in large gaps. 3 Light levels in the centres of gaps were significantly related to size of the canopy opening. After 1 year, light levels near the ground in larger openings (35–40% full sunlight immediately after treefall) declined to levels similar to those in smaller gaps (10–20%). 4 Although canopy opening had only slight effects on soil NH4-N, NO3-N pools were significantly greater in gaps than in understorey at both sites. The effect was positively correlated with gap size. Extractable PO4-P was also greater in gaps than in adjacent understorey, although the difference did not vary as a function of gap size. In three of six gaps, fine root biomass was less in gaps than in adjacent understorey. 5 Of four species of Miconia, only M. affinis, a small tree common in early secondary forests, grew significantly faster in fertilized than in non-fertilized treatments in three large gaps. 6 Our data suggest that higher nutrient pools in surface soils of treefall gaps may result from decomposition and mineralization of the large mass of fresh litter from the fallen tree. While growth rates of shade-tolerant rain forest trees and shrubs are not much affected by the increased nutrient availability even at high light levels, growth rates of pioneer or high-light demanding species may be enhanced by increased above- and below-ground resources.