cssi/SciSciGPT-SciSciNet huggingface dataset:
Shedding light on plant litter decomposition: advances, implications and new directions in understanding the role of photodegradation

Litter decomposition contributes to one of the largest fluxes of carbon (C) in the terrestrial biosphere and is a primary control on nutrient cycling. The inability of models using climate and litter chemistry to predict decomposition in dry environments has stimulated investigation of non-traditional drivers of decomposition, including photodegradation, the abiotic decomposition of organic matter via exposure to solar radiation. Recent work in this developing field shows that photodegradation may substantially influence terrestrial C fluxes, including abiotic production of carbon dioxide, carbon monoxide and methane, especially in arid and semi-arid regions. Research has also produced contradictory results regarding controls on photodegradation. Here we summarize the state of knowledge about the role of photodegradation in litter decomposition and C cycling and investigate drivers of photodegradation across experiments using a meta-analysis. Overall, increasing litter exposure to solar radiation increased mass loss by 23% with large variation in photodegradation rates among and within ecosystems. This variation was tied to both litter and environmental characteristics. Photodegradation increased with litter C to nitrogen (N) ratio, but not with lignin content, suggesting that we do not yet fully understand the underlying mechanisms. Photodegradation also increased with factors that increased solar radiation exposure (latitude and litter area to mass ratio) and decreased with mean annual precipitation. The impact of photodegradation on C (and potentially N) cycling fundamentally reshapes our thinking of decomposition as a solely biological process and requires that we define the mechanisms driving photodegradation before we can accurately represent photodegradation in global C and N models.
Elimination of the fibre chromatic dispersion penalty on 1550 nm millimetre-wave optical transmission

Dispersion causes a power penalty at certain fibre distances and frequencies in conventional millimetre-wave intensity modulation. Single sideband optical modulation at millimetre-wave frequencies using a fibre Bragg grating eliminates the dispersion-induced penalty over modulation frequency and fibre length.
Application of quality assurance practices in processing cells and tissues for transplantation

Attention to issues of quality assurance from the early stages of development of experimental cell therapies provides a margin of safety for recipients. Adherence to minimum standards of practice at acquisition, processing, storage, and implantation ensures not only this baseline safety factor for patients, but also provides a baseline for comparative evaluations between different studies or different banks. This paper describes the basic components of a quality assurance program tailored to laboratories and facilities that collect, process, or distribute human cells and tissues for transplantation. These components include policy and procedure manuals, donor screening practices, processing procedures evaluation and control, training and education programs, auditing and investigation roles, responsibility for release of grafts, and recordkeeping and traceability requirements. References and resources for detailed information related to good manufacturing practices and good clinical and laboratory practices are provided. Standards, regulations, and current legislation specifically related to human cells and tissues intended for transplantation are also discussed.
Wurfelspiel-based training data methods for ATR

ABSTRACT A data object is constructed from a P × M W¨ urfelspiel matrix W by choosing an entry from each column toconstruct a sequence A 0 A 1 ·A M  1 . Each of the P M possibilities are designed to correspond to the same categoryaccording to some chosen measure. This matrix could encode many types of data.1. Musical fragments, all of which evoke sadness; each column entry is a 4 beat sequence with a chosenA 0 A 1 A 2 thus 16 beats long ( W is P × 3).2. Paintings, all of which evoke happiness; each column entry is a layer and a given A 0 A 1 A 2 is a paintingconstructed using these layers ( W is P × 3).3. abstract feature vectors corresponding to action potentials evoked from a biological cells exposure to atoxin. The action potential is divided into four relevant regions and each column entry represents thefeature vector of a region. A given A 0 A 1 A 2 A 3 is then an abstraction of the excitable cells output ( W isP × 4).4. abstract feature vectors corresponding to an object such as a face or vehicle. The object is divided intofour categories each assigned an abstract feature vector with the resulting concatenation an abstract rep-resentation of the object ( W is P × 4)..All of the examples above correspond to one particular measure (sad music, happy paintings, an introducedtoxin, an object to recognize) and hence, when a W¨ urfelspiel matrix is constructed, relevant training informationfor recognition is encoded that can be used in many algorithms. The focus of this paper is on the application ofthese ideas to automatic target recognition (ATR). In addition, we discuss a larger biologically based model oftemporal cortex polymodal sensor fusion which can use the feature vectors extracted from the ATR W¨ urfelspieldata.Keywords: W¨ urfelspiel Matrices, Target Recognition, Sensor Fusion
Thermal Chemistry of Dihalopropanes on Ni(100) Single-Crystal Surfaces: Formation of Cyclopropane, Propene, and Propane

The thermal chemistry of 1,3-diiodopropane, 1-chloro-3-iodopropane, 1-iodopropane, 1-chloropropane, 3-chloropropene, propene, and cyclopropane on Ni(100) surfaces has been studied under ultrahigh vacuum conditions by using temperature-programmed desorption (TPD) and X-ray photoelectron spectroscopy (XPS). Cyclopropane, propene, propane, and hydrogen are all produced by thermal activation of the diiodopropane at low coverages, and iodopropane and molecular desorption are also seen at higher coverages. In contrast with this, only cyclopropane, propene, and chloropropanebut no propanewere observed after thermal activation of 1-chloro-3-iodopropane. Both I 3d and Cl 2p XPS spectra suggest that the adsorption of the dihaloalkanes is molecular below 100 K and that at low coverages both halogen atoms interact directly with the surface. They also point to the fact that the C−I (C−Cl) bonds break between 140 and 180 K in steps that most likely lead to the generation of a three-carbon metallacycle on the surface. T...
Efficient estimation of hybrid systems with applications to tracking

Particle filtering has been recognised as a superior alternative to the traditional estimation methods as it is applicable to nonlinear/non-Gaussian system. A central issue in real-time applications of particle filtering is its high computational cost. This problem is compounded when it is used in hybrid system estimation. A new particle filtering method for nonlinear/non-Gaussian hybrid system estimation is proposed in this article. The new method integrates the high-accuracy interacting multiple model particle filtering algorithm with the computationally efficient observation and transition-based most likely modes tracking particle filtering algorithm to get high-accuracy estimation with reduced computational load. The algorithm is applied to a manoeuvring target tracking application to demonstrate its efficiency.
Managing depressive and anxiety disorders with escitalopram.

This article reviews escitalopram, the S-stereoisomer of the racemic compound citalopram, and a highly selective and potent member of the selective serotonin re-uptake inhibitor class of antidepressants. Escitalopram has a straightforward pharmacokinetic profile, little effect on hepatic metabolism, and is relatively safe in overdose. Similar to other members of the selective serotonin re-uptake inhibitor class, escitalopram (10 – 20 mg/day) is a well-tolerated and effective treatment of major depressive disorder. Although relatively few head-to-head comparative studies with other antidepressants have been published, pooled analyses of studies using citalopram as the active comparator suggest a modest advantage for the stereoisomer. This advantage, which is more apparent among patients with greater symptom levels, may be attributable to a greater than predicted potency compared with citalopram, presumably as a result of the greater effect of escitalopram at the allosteric binding site of the serotonin tra...
Representation issues in information retrieval system design

The representation problem confronting information retrieval system designers is outlined in terms of three issues: what to represent, forms of representation, and functions of representation. Questions raised by each of these issues are identified and selected research projects which have begun to explore these questions are described.
Exponential intravenous infusions in toxicological studies: achieving identical serum drug concentration profiles in individuals with altered pharmacokinetic states.

It is common practice in the clinical setting to adjust the dosage of a drug administered to a patient with altered pharmacokinetic characteristics, e.g., renal impairment, in such a way that the steady-state level of the drug is the same as that which would be observed in normal patients. This may also be done in experimental studies of the interaction of drug toxicity and a disease state. Dosage adjustment does alter average steady-state serum concentrations but the resulting concentration-time profiles of the normal and the diseased groups will be of entirely different shapes due to differences in elimination. In a toxicological study, this would lead to a confounding of the disease state and the difference in exposure. In this paper, model-independent deconvolution analysis is applied to derive the infusion schedule needed to achieve a constant serum concentration followed by a predetermined monoexponential decline in concentration. The resulting exponential infusion is applied to attain identical serum gentamicin concentration-time profiles in five pairs of subtotally nephrectomized and normal dogs during a 12-h infusion.
Acoustic emission study of phase relations in low-Y2O3 portion of ZrO2-Y2O3 system

The (metastable) tetragonal phase in 3–4 mol% Y2O3-ZrO2 alloys undergoes a transition to the monoclinic form in the 200–300 °C temperature range. Microcracking due to the volume change at this transition has been detected in these compositions by sharp acoustic emission during heating. The phase change was confirmed by X-ray diffraction, dilatometry and scanning electron microscopy. The monoclinic ⇌ tetragonal transition in ZrO2-1 mol% Y2O3 alloy at 850–750 °C and the same phase change in 2, 3, 4 and 6 mol% Y2O3 compositions at the eutectoid temperature of about 560 °C was also clearly signalled by the acoustic emission counts during heating and cooling. There was no significant acoustic emission activity on heating and cooling the 9 and 12 mol% Y2O3 compositions, which are cubic. The acoustic emission data thus confirm the phase relations in the 1–12 mol% Y2O3 region, established by conventional methods such as differential thermal analysis, dilatometry and X-ray diffraction.
MOLECULAR DEFECTS IN HÆMOPHILIA A AND VON WILLEBRAND'S DISEASE

A model is proposed for the synthesis of the factor VII/von Willebrand factor protein. The defect(s) in von Willebrand's disease are related to abnormalities of the protein subunit and/or its carbohydrate content, while in haemophilia the abnormality is related to a deficiency or abnormality of the X-dependent enzyme or protein which is involved in the generation of procoagulant activity of the factor VII/von Willebrand factor multimer.
Get em while they last! Effects of scarcity information in job advertisements.

Participants in Study 1 (N= 172) were presented with a restaurant server advertisement differing by vacancy availability (scarce vs. plentiful) and scarcity type (number of vacancies vs. time to apply). Companies advertising only a few vacancies available were perceived as paying a significantly higher hourly wage than companies advertising many vacancies available. Also, both vacancy scarcity and time scarcity had positive effects on various company-image perceptions. Study 2 (N= 181) replicated most of the findings in Study 1 using a different entry-level job advertisement. However, although presentation mode (i.e., advertisement vs. factual) had a main effect on intention to apply, it did not interact with vacancy scarcity.
Anisotropy of the chemical shift tensor for solid carbon monoxide

Abstract The chemical shift anisotropy Δσ = σ|| − σ⊥ of the CO molecule has been measured by 13C NMR in the solid α phase of carbon monoxide. A polycrystalline sample, enriched to 93.7% in 13C, was used and Δσ was deduced from computer simulation of the experimental powder-pattern lineshape. A small amount of anomalous structure appears in the lineshape, which may be due either to preferred orientation of crystallites or to slow reorientational motion that is possibly associated with molecular ordering in the solid. The measured chemical shift anisotropy is 365 ± 20 ppm at 4.2 K, decreasing to 335 ± 20 ppm at 46 K. Rapid librational motion of the molecules produces motional averaging responsible for the temperature dependence. The averaging factor was estimated in the harmonic approximation using published Raman frequencies to be 0.90 ± 0.02 at 4.2 K and 0.83 ± 0.02 at 46 K, in excellent accord with the observed temperature dependence of Δσ. The chemical shift anisotropy for a static molecule is 406 ± 30 ppm. This value is in good agreement with theoretical estimations based on a molecular beam measurement of the spin-rotational interaction and ab initio calculations of the diamagnetic shielding.
Caffeine and diazepam: separate and combined effects on mood, memory, and psychomotor performance

The effects of caffeine and diazepam on several mood, cognitive, learning, memory, and psychomotor tasks were investigated in a double-blind study of 108 young healthy adults who were randomly assigned to nine treatments; oral administration of caffeine (0, 3 and 6 mg/kg), diazepam (0, 0.15, and 0.30 mg/kg) and their combinations. Subjects completed a battery of tasks once before and twice after administration of the drugs. Caffeine alone showed no effects on cognitive, learning, and memory performance, but impaired fine motor coordination and increased anxiety and tenseness. Diazepam alone produced sedation, lowered other ratings of subjective moods, and impaired cognitive, learning, and memory performance. The two drugs did not antagonize the effects of each other, except in the symbol cancellation task.
The Arf invariants of Brieskorn-Pham singularities

In particular B(x, x) = 0 and B( y, x) = B(x, y) for all x, y E V. Two such triples (V, B, Q) and (V’, B’, Q’) are called isometric, denoted by =, if there exists a linear isomorphism A: V+ v’ such that Q’(Ax) = Q(x) and so B’(Ax, Ay) = B(x, y) for all x, y E V. From two such triples (V,, B,, Q,) and (V,, B,, Q,) a third one (V,, B,, Q3) can be constructed by taking V, = V, x V,, B,( (x1, x,), (Y,, .d)=B,(xl, Y~)+BA%~ ~4, Q,(b,, xz))=Ql(xl)+ Qh). This construction is called orthogonal sum and denoted by 1. Any quadratic form (V, B, Q) is isometric to a repeated orthogonal sum of the following four types:
A Two Surface Model for Transient Nonproportional Cyclic Plasticity, Part 1: Development of Appropriate Equations

A two surface stress space model is introduced with internal state variable repositories for fading memory of maximum plastic strain range and non-proportionality of loading. Evolution equations for isotropic hardening variables are prescribed as a function of these internal variables and accumulated plastic strain, and reflect dislocation interactions that occur in real materials. The hardening modulus is made a function of prior plastic deformation and the distance of the current stress point from the limit surface. The kinematic hardening rules of Mroz and Prager are used for the yield and limit surfaces, respectively. The structure of the model is capable of representing essential aspects of complex nonproportional deformation behavior, including direction of the plastic strain rate vector, memory of plastic strain range, cross-hardening effects, variation of hardening modulus, cyclic hardening or softening, cyclic racheting, and mean stress relaxation.
On the Calculation of Rotational Line Strength Factors for Doublet Transitions

Abstract The calculation of rotational line strength factors S (J) for doublet-doublet transitions is useful in many aspects of quantitative spectroscopy, since many free radical spectra involve such transitions. The important situation in which the angular momentum coupling is intermediate between Hund's cases (a) and (b) has been treated by Hill and Van Vleck1. Their equations for S (J) form the basis of this note. The simplest type of doublet transition is 2σ(b) → 2σ(b), and these S(J) factors are given by Herzberg2. Earls3 has given S(J) in simplified algebraic forms for the 2σ(b) ↔ 2π transition with intermediate coupling in the 2π state. A more modern derivation of the doublet S(J) factors has been given by Rubin4 in terms of Wigner j symbols, but it is only derived for transitions between either pure case (a) or pure case (b). The S(J) factors for transitions of higher electronic angular momentum states (Δ, φ[ldot][ldot][ldot]) with intermediate coupling, while algebraically complex, can be express...
Constructing Death: Three Pathographies about Dying.

Ours is a culture in search of an ars moriendi. Today's popular narratives about illness and dying propose a variety of models for “the good death.” Three such pathographies are discussed as examples. In each, the author organizes the phenomena associated with the illness and death of a spouse from cancer into a coherent pattern and gives them a specific meaning. The result is three very different paradigms of the experience of dying-“ritual death,” “victorious death,” and “one's own death”-three potential versions of an art of dying for our time.
The effects of an unpredictable precipitation regime on vernal pool hydrology

SUMMARY 1. Vernal pools are small precipitation-fed temporary wetlands once common in California. They are known for their numerous narrowly endemic plant and animal species, many of which are endangered. These pools experience the typical wet season/ dry season regime of Mediterranean climates. Their hydrological characteristics are determined by a complex interaction between the highly variable climate and topographic relief. 2. Hypotheses regarding the effects on ponding of total precipitation, storm intensity and pattern were examined using long-term weather records combined with two decades of data on the length and depth of inundation in 10 individual pools. Similarly, data on pool landscape position and microtopography allowed examination of the interactions between topography and rainfall amount and pattern. 3. The total amount of precipitation and length of inundation were strongly correlated. Landscape position affected ponding duration, with collector pools holding water longer than headwater pools. Basin microtopography interacted with climatic variability to determine the nature and extent of within-basin microhabitats sufficiently different in hydrological and/or soil conditions to support or exclude individual species. The effect on hydroperiod of precipitation concentrated in a few months rather than spread more evenly over the season depended on total precipitation. 4. Changes in climate, the mound-and-depression landscape or pool microtopography could have profound impacts on the hydrology of individual pools as well as the array of hydrological conditions in the system. Given the individualistic responses of the numerous endemic species supported by vernal pools, any of these environmental changes could diminish their sustainability and increase the risk of species extinction. Conservation, restoration and management decisions should take these factors into account.
Deep-water benthic algae of the Florida Middle Ground

The composition and seasonality of the benthic algae of the Florida Middle Ground, an offshore area of extensive reef outcroppings, 25 to 60 m deep in the eastern Gulf of Mexico, are described. Collections and observations were made by SCUBA diving during June, July, and September, 1971, and January 1972. Ninety-one algal species (92 taxa) were obtained, including 6 species newly reported for Florida and the eastern Gulf of Mexico. The flora is predominantly tropical, with Caribbean affinities. Marked seasonal differences in species diversity and abundance were present. An extensive or well-anchored holdfast system was a common feature of those species which appeared to be perennial.
Reduced chemotactic peptide binding in juvenile periodontitis: A model for neutrophil function

Abstract Chemotactic peptide binding sites from peripheral blood neutrophils of Localized Juvenile Periodontitis patients and normal controls were quantitated using tritiated N-formylmethionylleucyl-phenylalanine and a rapid filtration assay. It was found that there is a significant reduction in the number of binding sites per cell on neutrophils from the patient group whereas binding affinity remained the same as control values. A direct correlation between in vitro neutrophil chemotactic response and density of binding sites was found. Since these patients present little clinical illness, localized juvenile periodontitis can be a valuable model for the study of human neutrophil function.
Making Historical Connections: Galton's Problem and Opportunity

Galton's problem, the issue of the effects of historical connections between societies based on their characteristics, has received much attention from cross-culturalists. The author reviews the three major responses to Galton's problem and points out that each response treats it as a methodological difficulty. I argue that it would be more fruitful to reframe Galton's problem as a substantive issue, for then cross-culturalists could develop a better under standing of the different kinds of connections among societies and their effects. Links between societies are important forces helping to shape life within each society. I support this argument with exam ples on intersocietal trading ofgoods, labor exchanges, warfare, and interbreeding.
Studies in Clinical Shock and Hypotension IV. Variations in Reflex Vasoconstriction and Cardiac Stimulation

Renal blood flow was measured by the indicator-dilution technic in 17 patients with shock related to sepsis, myocardial infarction, pulmonary embolism, or pancreatitis. Renal blood flow averaged 225 ml/min/kidney, the renal plasma transit time was prolonged to an average of nearly three times normal, and the renal fraction of cardiac output was reduced to an average of 10.6%. A direct relationship between renal vascular resistance and systematic nonrenal vascular resistance suggested that renal vasocontriction was a manifestation of a more generalized vasoconstrictor process. Since rapid infusion of dextran in patients with normal central venous pressure relaxed renal vasoconstriction and tended to increase the renal fraction, inadequate venous return apparently is an important factor in the reduced renal blood flow in shock. None of the vasoactive drugs used were effective in restoring normal renal perfusion. The vasoconstrictor drugs (norepinephrine, metaraminol, and angiotensin) increased arterial pres...
Empirical investigation of the impact of extreme programming practices on software projects

Extreme Programming (XP) is an agile software development methodology composed of several practices that purportedly yield high quality and high customer satisfaction. However, there has been little formal investigation of these claims. We conduct empirical, industrial case studies to evaluate XP. Results from two case studies are presented.
Double distribution of dark matter halos with respect to mass and local overdensity

We present a double distribution function of dark matter halos, with respect to both object mass and local over- (or under-) density. This analytical tool provides a statistical treatment of the properties of matter surrounding collapsed objects, and can be used to study environmental effects on hierarchical structure formation. The size of the ``local environment'' of a collapsed object is defined to depend on the mass of the object. The Press-Schechter mass function is recovered by integration of our double distribution over the density contrast. We also present a detailed treatment of the evolution of overdensities and underdensities in ${\ensuremath{\Omega}}_{\mathrm{m}}+{\ensuremath{\Omega}}_{\ensuremath{\Lambda}}=1$ and ${\ensuremath{\Omega}}_{\mathrm{m}}=1$ universes according to the spherical evolution model. We explicitly distinguish between true and linearly extrapolated overdensities and provide conversion relations between the two quantities.
TBBT: scalable and accurate trace replay for file server evaluation

This paper describes the design, implementation, and evaluation of TBBT, the first comprehensive NFS trace replay tool. Given an NFS trace, TBBT automatically detects and repairs missing operations in the trace, derives a file system image required to successfully replay the trace, ages the file system image appropriately, initializes the file server under test with that image, and finally drives the file server with a workload that is derived from replaying the trace according to user-specified parameters. TBBT can scale a trace temporally or spatially to meet the need of a simulation run without violating dependencies among file system operations in the trace.
Adhesive grass spikelet with mammalian hair in Dominican amber: first fossil evidence of epizoochory.

Discovery of a female spikelet of the grass genusPharus (Gramineae: Bambusoideae: Phareae) in association with mammalian hair in Dominican Republic amber provides the first fossil evidence of epizoochory. Hooked macrohairs on the lemma of the spikelet show that morphological modifications in grasses for dispersal by attachment to the surface of animals were present in the Late Eocene. The fossil also represents 1) the second-oldest undoubted macrofossil record of the Gramineae, 2) the earliest record of a fossil grass that can be assigned to an extant genus, 3) the earliest undoubted record of a member of the bamboo subfamily and 4) the only known fossil ofPharus.
Process and economic evaluation for monoclonal antibody purification using a membrane-only process

In recent years, the market for therapeutic monoclonal antibodies (mAb) has grown exponentially, and with this there has been a desire to reduce the costs associated with production and purification of these high-value biological products. A typical mAb purification process involves three adsorption/chromatography steps [protein A, ion exchange (IEX), and hydrophobic interaction (HIC)], along with ultrafiltration, nanofiltration, and microfiltration. With the development of membrane adsorption/chromatography as a viable alternative to traditional pack bed systems, the opportunity exists to complete the entire downstream purification process using only membrane operations. In this study, the process simulation tool SuperPro Designer was used to evaluate the application of recently developed ultra-high capacity electrospun nanofibrous adsorption membranes as a replacement for conventional chromatographic media in the downstream mAb production process. The simulation showed that nanofibrous adsorption membranes in place of the three packed bed chromatography steps reduced the required volume of protein A, IEX, and HIC adsorptive medium by 25, 80, and 80%, respectively. In addition, the membrane-only process reduced the downstream processing time by 50%, decreased the number of labor hours associated with the purification steps by 40%, generated 40% less aqueous waste, and reduced the overall downstream process operating expenses per unit product by 23%. There were also significant savings in facility construction costs and the price of fixed equipment required for separations. With these savings not only is the membrane-only process economically competitive with the traditional packed bed operations, but it offers the possibility of moving toward more disposable process.
Are acquisitions by utility firms beneficial

Utility firms are subject to peculiar regulatory characteristics that may allow for unique wealth effects resulting from acquisitions. The wealth effects derived from acquisitions of utility firms is measured and the analysis reveals negative wealth effects for acquirers and positive wealth effects for targets. However, the wealth effects are generally less favorable for utility firm acquirers than other acquirer firms because of the regulatory barriers that prevent them from pursuing attractive targets.
The current need for “theological counsel”

“Pastoral psychology” was an answer to pre-World War II problems in counseling, such as arbitrary prescription without psychological diagnosis, the confusion of morality with morals, the dominance of pastor over parishioner, appeals to the will without a recognition of deeper emotional motivations. The solutions of pastoral psychology, as seen in early issues ofPastoral Psychology magazine, were to assume a “non-directive” approach without prescription or diagnosis, to center attention on the deeper needs of a parishioner and abandon any preoccupation with cultural taboos, to stress independence from others rather than an infantile conscience, to shift responsibility for change from counselor to counselee and to relate the will to unconscious centers of the affection. By the 1980s several deficiencies had appeared in the solutions of pastoral psychology, namely an incipient humanism that grew out of the optimistic assertion of self realization and a lack of attention to worship, a sense of the holy and spiritual resources. Various authorities recommend theological systems building as an answer to these deficiencies.
Effectiveness of laparoscopic varicocelectomy

Abstract Laparoscopic varicocelectomy is a new technique which has been described in a limited number of clinical reports. We reviewed the results of 46 patients undergoing laparoscopic repair of 75 varicoceles over a two-year period to assess the effectiveness of this operative technique. The internal spermatic artery was preserved in 80 percent of the varicoceles and two arteries were present in 5 percent. Our ability to preserve the internal spermatic artery improved significantly with the use of the intraoperative Doppler probe after the first six months of performing this operation (p
The effect of chewing gum on learning as measured by test performance

Summary This research project investigated the relationship between chewing gum and short-term learning, as prior studies had reported conflicting results. Incoming first-year dental students were assigned by stratified randomisation to either a group who chewed gum during lectures and examinations or a group that did not chew gum. The research subjects listened to a taped lecture on dental anatomy and then completed two examinations: (1) a test of specific knowledge which was a multiple-choice test on the dental anatomy lecture material; and (2) a test of generalised knowledge which was a standardised reading comprehension exam. Statistical analysis of the results showed that in a group of graduate students with a history of high academic performance, there was no difference in learning between research subjects who chewed gum compared with those who did not chew gum, as measured by performance on either test.
Robot motion planning with uncertainty in control and sensing

Abstract Most of the research in robot motion planning has focused on finding a collision-free path connecting two configurations of the robot among obstacles, under the assumptions that geometric models are complete and accurate and that robot control is perfect. In this paper we consider the problem of planning motion strategies in the presence of uncertainty in both control and sensing, using the preimage backchaining approach. Though attractive, this approach raises difficult computational issues. One of them, preimage computation, is the main topic of this paper. We describe two practical methods for computing preimages for a robot having a two-dimensional Euclidean configuration space. We also propose a combination of these two methods which yields the most powerful practical method devised so far for computing preimages. A motion planner based on these methods has been implemented and experimental results are given in this paper. We discuss non-implemented improvements of this planner, including a new way to embed knowledge in a motion command in order to produce larger preimages.
Use of radiographs to measure outcome in rheumatoid arthritis.

Abstract Currently, radiographic analysis of the hands and wrists provides the most practical, useful, and objective biologic endpoint for measurement of outcome in rheumatoid arthritis. Semiquantitative scoring methods for cartilage loss and osseous erosions developed by Sharp (Arthritis Rheum 1971; 14: 706–720) and Larsen (Scand J Rheum 1973; 2: 136–138) have established standards for sensitivity and interobserver reliability. Sharp (Arthritis Rheum 1985; 28: 16–24) has shown that in order to reliably measure change in erosion score, a certain degree of worsening (i.e., progression) must take place. At least one year is necessary, preferably two. Others have shown that rheumatoid arthritis erosions take place and progress early (Years 1 to 3) in most patients, and once destruction is established it may not be possible to adequately assess further change radiographically. Therefore, in order to perform a clinical trial of "disease modifying" agents with radiographic analysis as endpoint, the selections of a proper study population and time interval are most critical. Although it may be difficult to perform, an ideal clinical study for a therapeutic intervention would use patients with rheumatoid arthritis of less than five years' disease duration and perform radiographic analysis at a 24-month minimum interval. The selection of a proper control group may be a near impossibility under these circumstances.
Fuzzy system models combined with nonlinear regression for daily ground-level ozone predictions

Abstract This study focuses on applying a Takagi–Sugeno fuzzy system and a nonlinear regression (NLR) model for ozone predictions in six Kentucky metropolitan areas. The fuzzy “c-means” clustering technique coupled with an optimal output predefuzzification approach (least square method) was used to train the Takagi–Sugeno fuzzy system. The fuzzy system was tuned by specifying the number of rules and the fuzziness factor. The NLR models were based in part on a previously reported, trajectory-based hybrid NLR model that has been used for years for forecasting ground-level ozone in Louisville, KY. The NLR models were each composed of an interactive nonlinear term and several linear terms. Using a common meteorological parameter set as input variables, the NLR models and the Takagi–Sugeno fuzzy systems model exhibited equivalent forecasting performance on test data from 2004. For all 2004 ozone season forecasts for the six metropolitan areas, the mean absolute error was 8.1 ppb for the NLR model and 8.0 ppb for the Takagi–Sugeno fuzzy model. When a nonlinear term (which was part of the NLR model) was included in the fuzzy model, the combined NLR–fuzzy model had slightly better performance than the original NLR model. For all 2004 metropolitan area forecasts, the mean absolute error of the NLR–fuzzy model forecasts was 7.7 ppb. These small differences may be statistically significant, but for practical purposes the performance of the fuzzy models was equivalent to that of the NLR models.
Simultaneous events and lookahead in simulation protocols

A discrete event simulation model may contain several events that have the same timestamp, referred to as simultaneous events. In general, the results of a simulation depend on the order in which simultaneous events are executed. Simulation languages and protocols use different, sometimes ad hoc, tie-breaking mechanisms to order simulataneous events. As a result, it may be impossible to reproduce the results of a simulation model across different simulators. This article presents a systematic analysis of the lookahead requirements for sequential and parallel simulation protocols, utilizing the process-oriented world view, with respect to their abililty to execute models with simultaneous events in a deterministic order. In particular, the article shows that most protocols, including the global event list protocol and commonly used parallel conservative and optimistic protocols, require that the simulation model provide some form of lookahead guarantee to enforce deterministc ordering of simultaneous events. The article also shows that the lookahead requirements for many protocols can be weakened if the model allows simultaneous events to be processed in a nondeterministic order. Finally, the lookahead properties that must be satisfied by a model in order for its execution to make guaranteed progress are derived using various simulation protocols.
A cumulative ecological–transactional risk model of child maltreatment and behavioral outcomes: Reconceptualizing early maltreatment report as risk factor

Abstract The current analysis was designed to critically examine the tendency to focus on child maltreatment as a unique risk factor and test the resulting assumption of a direct causal relationship between early maltreatment and later behavioral problems. The variation seen in behavioral outcomes among children reported for maltreatment early in life led us to hypothesize that the cumulative level of risk facing children and their families can, at least in part, account for that variation in outcome. Participants were 242 mothers of predominantly at-risk newborn infants who were interviewed shortly after giving birth. The State Central Registry of Maltreatment was then reviewed over each child's first four years of life to assess for early maltreatment. Following the neonatal interviews, mothers completed the Child Behavior Checklist when their children were 4, 6, 8, 10 and 12 years-of-age. Although early maltreatment report does appear to be important to early child functioning, the cumulative level of risk more strongly predicts long-term clinical behavioral difficulty. High-risk children who were not reported for maltreatment by age 4 demonstrate greater behavioral problem trajectories than did low-risk children with a maltreatment report. Maltreatment itself may be best conceptualized as an important, but not singularly so, risk factor for later behavioral problems. In focusing directly on reported maltreatment, our child protective systems may be paying too little attention to what else is going wrong in the lives of children and targeting intervention efforts in the wrong direction. When it comes to early maltreatment our child protective policy and practice need to broaden their lenses to include greater emphasis on overall family functioning, stress and well-being. Early maltreatment, it seems, may be a symptom of more profound problems in the early environments of our most vulnerable children, rather than the problem itself.
The development of a three-frame timeline for clinical concepts extracted from discharge summaries

Materials and methods Utilizing Knowtator, a schema was designed to relate clinical concepts within discharge summary sections, including disease states, procedures, lab results, and medications, to a timeline. The timeline was defined by three frames: PreAdmission, Hospital Stay, and Post-Discharge. Fifty-five discharge summaries from the i2b2 NLP Challenge were randomly selected for review. Clinical concepts were manually extracted, categorized within the appropriate frame, and compared to the MetaMAP and YTEx systems to establish a gold standard. It was observed that concepts in the same section correlated to the same frame in the timeline. Additionally, the frame was determined through the classification of section titles. The same method could be further refined to associate clinical concepts with more specific date and time markers, leading to a comprehensive view of the medical timeline.
INTRANUCLEAR AND CYTOPLASMIC ANNULATE LAMELLAE IN TUNICATE OOCYTES

Electron microscope studies were made on various tunicate oocytes at different stages of growth and development. Both the inner and outer lamellae of the perforated nuclear envelope demonstrate considerable blebbing activity. The blebs of the inner lamella detach into the nucleoplasm where they undergo a special type of fusion process resulting in the formation of numerous, usually single, differentiated annulate lamellae of various lengths. The blebbing of the outer layer of the nuclear envelope contributes to the vesicular and granular endoplasmic reticulum characteristically present in the ooplasm and perhaps to the differentiation of cytoplasmic annulate lamellae as well. Cytoplasmic stacks of annulate lamellae frequently have ribosomes associated with them. In addition, granular accumulations are sometimes observed around or between the annuli. The morphological evidence suggests that, at least in many cases, the annuli in the annulate lamellae are patent.
Removing unimportant computations in interprocedural program analysis

Existing solutions to program analysis problems often trade between scalability and precision. We propose new techniques to improve scalability of interprocedural high-precision program analyses without sacrificing precision. The key insight is that there is a high volume of unimportant computations in these analyses. Our way to improve analysis time is by identifying and reducing these computations. We identify unimportant work in three classes of program analyses: flow-sensitive dataflow analysis, context-sensitive dataflow analysis, and reachability-based analysis. We propose new algorithms to reduce this inefficiency. We are interested in analysis problems and programs that involve pointers, because they are used in many modern languages. Their presence sometimes complicates the analysis problems, and they sometimes raise the problem size due to large points-to sets in the program. Our solutions include an improved worklist management algorithm used in flow-sensitive interprocedural analysis that drastically reduces the amount of work placed on the worklist. We introduce Relevance-Based Context Partitioning, a new algorithm that groups contexts together in a way such that only important information will be computed precisely, and that the number of contexts to analyze is considerably smaller. For the class of reachability-based analysis, the way to improve scalability is to reduce the graph used in the analysis. The nodes in the graph represent dataflow facts, while the edges represent flow functions. The analysis problem is then reduced to a reachability problem. Compared to existing efficient algorithms, we present two new algorithms that significantly reduce the size of the graphs. The first idea uses the graph to represent data dependences instead of the more indirect control dependences that are typically used. The second idea identifies nodes that can be eliminated, because they do not contribute to solving the analysis problem. We evaluate our ideas by applying our algorithms to five error-checking analyses and by comparing results against state-of-the-art algorithms, using a large suite of 19 open-source programs. We are able to improve performance significantly. Our new algorithms for flow-sensitive analysis achieve approximately 2× speedup, on average. For context-sensitive analysis, our technique sometimes also allows the new algorithm to solve cases that previously could not be solved due to run out of memory. For other cases, the average speedup is 7.0× and can be more than 200× in some cases. Finally, our new algorithms for reachability-based analysis can produce graphs that are just 6% the size of the original graphs. Consequently, more benchmarks can be analyzed successfully, and the average analysis time speedup is as high as 5.5× faster.
Quantifying the impact of groundwater depth on evapotranspiration in a semi-arid grassland region

Abstract. Interactions between shallow groundwater and land surface processes play an important role in the ecohydrology of riparian zones. Some recent land surface models (LSMs) incorporate groundwater-land surface interactions using parameterizations at varying levels of detail. In this paper, we examine the sensitivity of land surface evapotranspiration (ET) to water table depth, soil texture, and two commonly used soil hydraulic parameter datasets using four models with varying levels of complexity. The selected models are Hydrus-1D, which solves the pressure-based Richards equation, the Integrated Biosphere Simulator (IBIS), which simulates interactions among multiple soil layers using a (water-content) variant of the Richards equation, and two forms of a steady-state capillary flux model coupled with a single-bucket soil moisture model. These models are first evaluated using field observations of climate, soil moisture, and groundwater levels at a semi-arid site in south-central Nebraska, USA. All four models are found to compare reasonably well with observations, particularly when the effects of groundwater are included. We then examine the sensitivity of modelled ET to water table depth for various model formulations, node spacings, and soil textures (using soil hydraulic parameter values from two different sources, namely Rawls and Clapp-Hornberger). The results indicate a strong influence of soil texture and water table depth on groundwater contributions to ET. Furthermore, differences in texture-specific, class-averaged soil parameters obtained from the two literature sources lead to large differences in the simulated depth and thickness of the "critical zone" (i.e., the zone within which variations in water table depth strongly impact surface ET). Depending on the depth-to-groundwater, this can also lead to large discrepancies in simulated ET (in some cases by more than a factor of two). When the Clapp-Hornberger soil parameter dataset is used, the critical zone becomes significantly deeper, and surface ET rates become much higher, resulting in a stronger influence of deep groundwater on the land surface energy and water balance. In general, we find that the simulated sensitivity of ET to the choice of soil hydraulic parameter dataset is greater than the sensitivity to soil texture defined within each dataset, or even to the choice of model formulation. Thus, our findings underscore the need for future modelling and field-based studies to improve the predictability of groundwater-land surface interactions in numerical models, particularly as it relates to the parameterization of soil hydraulic properties.
Recombination and the power of statistical tests of neutrality

Two new test statistics were constructed to detect departures from the equilibrium neutral theory that tend to produce genealogies with longer internal branches (e.g. population subdivision or balancing selection). The new statistics are based on a measure of linkage disequilibrium between adjacent pairs of segregating sites. Simulations were run to determine the power of these and previously proposed test statistics to reject an island model of geographic subdivision. Unlike previous power studies, this one uses a coalescent model with recombination. It is found that recombination rates on the order of the mutation rate substantially reduce the power of most test statistics, and that one of the new test statistics is generally more powerful than the others. Two suggestions are made for increasing the power of the statistical tests examined here. First, they can be made more powerful if critical values are obtained from simulations that condition on a lower bound for the population recombination rate. Secondly, for the same total length sequenced, power is increased if independent loci are considered instead of a single contiguous stretch.