cssi/SciSciGPT-SciSciNet huggingface dataset:
Climate Change, Land‐Use Change, and Floods: Toward an Integrated Assessment

Floods occur from a combination of various hydrological, climatological, and land-use conditions. In this article, we review recent studies to identify primary causes of floods in different regions. These studies suggest that changes in precipitation intensity or amount are responsible for increasing floods in coastal cities, which may also be impacted by sea-level rise and an increase in the incidence of tropical storms due to global warming and land modifications at different scales enhance vulnerability to flood risks. They indicate the current challenges in flood research include: (i) the integration of data collected at various scales; (ii) the quantification of various feedbacks and uncertainty between climatic and hydrologic systems; (iii) the combination of climate and land-use models for flood assessment; and (iv) linking flood damage caused by changing climate or land use with spatially explicit socioeconomic data. Specifically, an integrated assessment method is needed to unravel the complex interactions among human systems, terrestrial systems, and climate systems that result in flood risks at multiple scales.
Negative oxygen ions in the upper atmosphere: The affinity and radiative attachment coefficient of atomic oxygen

The influence of negative ions of atomic oxygen on the physics of the ionosphere and night airglow is re-examined in the light of new experimental determinations of the oxygen affinity (1.48 ± 0.10 ev) and photodetachment cross section. The radiative attachment coefficient is calculated from the photodetachment cross section. There is no evidence of a resonance at the threshold, where the attachment coefficient is approximately 1.2 × 10−15 cm3/ sec.
SIRTF: an overview

This paper reports on the status of SIRTF--the Space Infrared Telescope Facility. SIRTF will be a cryogenically- cooled space telescope instrumented with large-format, state of the art infrared detector arrays. SIRTF will complete NASA's family of Great Observatories and also serve as a cornerstone of the Origins program. SIRTF will be launched in 2001, carrying a complement of imaging and spectroscopic instrumentation, for a mission approximately 5 yr in duration. SIRTF will be placed in an earth-trailing heliocentric orbit; the very favorable thermal environment of this orbit has enabled a novel warm-launch architecture for the cryogenic system. More than 75% of the observing time on SIRTF will be available to the general scientific community. The community involvement in SIRTF began in June of 2000 with the formal release of the call for Legacy Science proposals.
Stability of forest biodiversity.

Two hypotheses to explain potentially high forest biodiversity have different implications for the number and kinds of species that can coexist and the potential loss of biodiversity in the absence of speciation. The first hypothesis involves stabilizing mechanisms, which include tradeoffs between species in terms of their capacities to disperse to sites where competition is weak1,2,3,4, to exploit abundant resources effectively5,6 and to compete for scarce resources7. Stabilization results because competitors thrive at different times and places. An alternative, ‘neutral model’ suggests that stabilizing mechanisms may be superfluous. This explanation emphasizes ‘equalizing’ mechanisms8, because competitive exclusion of similar species is slow. Lack of ecologically relevant differences means that abundances experience random ‘neutral drift’, with slow extinction9,10,11. The relative importance of these two mechanisms is unknown, because assumptions and predictions involve broad temporal and spatial scales. Here we demonstrate that predictions of neutral drift are testable using palaeodata. The results demonstrate strong stabilizing forces. By contrast with the neutral prediction of increasing variance among sites over time, we show that variances in post-Glacial tree abundances among sites stabilize rapidly, and abundances remain coherent over broad geographical scales.
Largest Molecular Clusters in the Supertetrahedral Tn Series

Supertetrahedral Tn clusters are exact fragments of cubic ZnS-type lattice and are often formed in situ as building units for the construction of 3-D open-framework chalcogenide materials. Small Tn clusters can also be synthesized in discrete forms, allowing them to exist as soluble species in solution. In addition to their tunable electronic and optical properties, these soluble clusters can be used as precursors for the synthesis of porous semiconducting and optical materials. However, the synthesis of large Tn clusters is a significant challenge, and for several decades prior to this work, the size of the discrete Tn cluster remained at T3, with only 10 metal sites (e.g., [Cd10S4(SPh)16]4− and [M5Sn5S20]10−, M = Zn, Co). Here we report a family of discrete chalcogenide T4 clusters ([MxGa18−xSn2Q35]12−, x = 2 or 4; M = Mn, Cu, Zn; Q = S, Se) whose discovery resulted from an unusual phase transformation from a 3-D T4 covalent framework into 0-D T4 molecular clusters. The driving force for such a transfor...
Growth and Characterization of Gan Bulk Crystals Via Vapor Phase Transport

Free-standing single crystals of bulk GaN were grown via unseeded vapor phase transport at 1130°C on hexagonal BN surfaces via direct reaction of Ga with ammonia. The number of nucleation events was reduced and the crystal size increased by introducing the ammonia at high temperatures. The resulting crystals were either needles or platelets depending on the process variables employed. Low V/III ratios achieved via ammonia flow rates ≤ 75sccm and/or ammonia total pressures ≤ 430Torr favored lateral growth. The average lateral growth rate for the platelets was ∼50μm/hr; the average vertical growth rate for the needles was ∼500μm/hr. Growth rates in all other directions for each of these two morphologies were very low. Seeded growth of both needle and platelet crystals was also achieved; however, the growth rate decreased at longer times and higher pressures due to reaction with H2 from the increased decomposition of ammonia. Nitrogen dilution suppressed this decomposition. A 2mm × 1.5mm GaN crystal was grown with minimal decomposition in a 66.7%NH3 and 33.3%N2 gas mixture.
Measurement of dilute 29Si species in solution using a large volume coil and DEFT NMR

A large-sample-volume nuclear magnetic resonance (NMR) spectroscopy probehead has been developed for the detection and characterization of low concentrations of 29Si species in aqueous solution. Th...
Using a Common Model: Mapping VRA Core 4.0 Into an RDF Ontology

Linked Data has become a very important way to share information on the Web. The Visual Resource Association (VRA) Core 4 eXtensible Markup Language (XML) schema was used as a basis for developing a new VRA ontology that was highly interoperable across the Web. Once the model was developed, an eXtensible Stylesheet Language Transformation (XSLT) style sheet was created to test the model against an actual VRA Core 4 data set. The study successfully demonstrated how popular and widely consumed vocabularies can be used to form the basis for more granular vocabularies. The study also demonstrated how existing data can be successfully converted into Resource Description Framework (RDF) using an XSLT style sheet.
Failure to produce response variability with reinforcement

Two experiments attempted to train pigeons to produce variable response sequences. In the first, naive pigeons were exposed to a procedure requiring four pecks on each of two keys in any order, with a reinforcer delivered only if a given sequence was different from the preceding one. In the second experiment, the same pigeons were exposed to this procedure after having been trained successfully to alternate between two specific response sequences. In neither case did any pigeon produce more than a few different sequences or obtain more than 50% of the possible reinforcers. Stereotyped sequences developed even though stereotypy was not reinforced. It is suggested that reinforcers have both hedonic and informative properties and that the hedonic properties are responsible for sterotyped repetition of reinforced responses, even when stereotypy is negatively related to reinforcer delivery.
The evolution of thunniform locomotion and heat conservation in scombrid fishes: New insights based on the morphology of Allothunnus fallai

Two significant functional differences—a more anterior and internally positioned red myoItomal muscle mass and modification of the red-muscle vascular supply to form counter-current heat exchangers—distinguish the tunas (tribe Thunnini) from other species in the teleost family Scombridae. Neither of these characteristics is found in the bonitos (tribe Sardini), the sister group to the Thunnini. The most recent scombrid classification places the slender tuna, Allothunnus fallai, in the tribe Sardini, but some earlier studies suggested that this species should be a member of the Thunnini. Allothunnus fallai does not possess the lateral subcutaneous arteries and veins or the lateral heat-exchanging retia typical of tunas. However, we have found that this species has a highly modified central circulation (dorsal aorta, post cardinal vein, and associated branch vessels) similar to the central heat-exchanging retia of certain tunas, an enlarged haemal arch to accommodate this structure, and the anterior, internal placement of red muscle characteristic of tunas. With these new characters, phylogenetic reconstructions based on parsimony place A. fallai as the sister taxon to the tunas, establish that it is the most basal tuna species, and support the hypothesis that the derivation of tunas from a bonito-like ancestor occurred through selection for an integrated set of characteristics affecting locomotion and endothermy. The major features of this hypothesis are as follows. (1) Selection for continuous, steady, and efficient swimming resulted in changes in body shape (the result of enlargement of the anterior myotomes, the anterior and internal shift of red muscle, and a narrowing of the caudal peduncle) which increased streamlining and led to the adoption of the thunniform swimming mode unique to the tunas. (2) Alterations in blood supply necessitated by the anterior shift in red muscle led to the interdigitation of numerous arterial and venous branches which set the stage for heat conservation. (3) The evolution of endothermy, together with thunniform swimming, contributed significantly to the ecological radiation and diversification of tunas during the Early Tertiary Period. Our studies of A. fallai thus suggest that the shift in red muscle position and changes in central circulation preceded the evolution of red-muscle endothermy. Co-evolutionary changes in red muscle quantity and distribution and in vascular specializations for heat conservation have led to different macroevolutionary trajectories among the now five genera and 14 tuna species of tunas and appear to reflect the influence of changing paleocological and paleoceanographic conditions, including cooling, that occurred in the Tertiary.
Autism Severity as a Predictor of Comorbid Conditions

The relationship between autism spectrum disorders (ASD) and comorbid disorders has become an increasingly popular area of study. This trend has been spurred by the recognition that many physical and psychological problems are present when a diagnosis of ASD has been confirmed. This paper studied comorbid psychopathology and challenging behaviors of 207 individuals diagnosed with ASD between 2 and 16 years of age. More severe symptoms of ASD resulted in more symptoms on multiple comorbidities. The implications of these data are discussed.
Organic carbon concentrations and transport in small mountain rivers, Panama

Abstract Tropical small mountainous rivers (SMRs) are increasingly recognized for their role in the global export of dissolved organic carbon (DOC) to the oceans. Here we utilize the Isthmus of Panama as an ideal place to provide first-order estimates of DOC yields across a wide assemblage of bedrock lithologies and land cover practices. Samples for dissolved organic carbon (DOC) analysis were collected across Panama along an E–W transect from the central Panama area to the Costa Rican border for 24 mainstem rivers, 3 large tributary rivers, and one headwater stream. Sampling occurred during both the wet and the dry seasons. DOC concentrations during the wet season are higher than during the dry season in all but three of the rivers. Concentrations vary greatly from river to river and from season to season, with values as low as 0.64 mg l −1 to greater than >25 mg l −1 with the highest concentrations observed for the rivers draining Tertiary marine sedimentary rocks in the Burica and Azuero peninsulas. DOC yields from Panamanian rivers (2.29–7.97 tons/km 2 /y) are similar to or slightly lower than those determined for other tropical SMR systems. Areas underlain by Tertiary aged sediments exhibited significantly higher mean DOC yields compared to their igneous counterparts, despite maintaining substantially lower aboveground carbon densities, suggesting the important influence of lithology. Finally, regression analyses between DOC yields and select watershed parameters revealed a negative and statistically significant relationship with maximum and mean gradient suggesting lower soil retention times may be linked to lower DOC yields.
Heavy‐metal toxicity in plants 1. A crisis in embryo

Abstract Heavy metals are often added indiscriminantly to soils in pesticides, fertilizers, manures, sewage sludges, and mine wastes, causing an imbalance in nutrient elements in soils. Heavy‐metal toxicity causes plant stress in various degrees dependent on the tolerance of the plant to a specific heavy metal. The objectives of this study were (i) to show that plant species and soils respond differently to heavy metals and (ii) to show the necessity for proper quantity and balance of heavy metals in soils for plant growth. Three Fe‐inefficient and three Fe‐efficient selections of soybean, corn, and tomato were grown on two alkaline soils with Cu and Zn ranging from 14 to 340 and Mn from 20 to 480 kg/ha. Heavy‐metal toxicity caused Fe deficiency to develop in these plants. The Fe‐inefficient T3238fer tomato and ys1/ys1 corn developed Fe deficiency on all treatments and both soils. T3238FER tomato (Fe‐efficient) did not develop heavy metal toxicity symptoms on any treatment or soil. The soybean varieties a...
WE‐C‐I‐609‐07: On Constructing Priors and Likelihoods for Deformable Shape Models

Purpose: Explicit deformable shape models (DSMs) can be used in a Bayesian statistical framework to provide a prioriinformation for posterior optimization to match the DSM against a target image for automatic segmentation. In this approach a DSM is initialized in the target image and undergoes a series of deformations to closely match the target object. Deformation is driven by optimizing an objective function with terms for geometric typicality (prior) and model‐to‐image match (likelihood). The purpose of this work was to develop strategy, methodology, and tools for constructing the geometric prior and intensity likelihood for a particular form of DSM called m‐reps. Method and Materials: Geometric truth is defined for an object of interest by a statistically significant collection of expert human segmentations of training images. M‐reps are fit to the human drawn contours by minimizing the distance between the surfaces of the m‐rep and the contours under added conditions that lead to positional correspondence across training cases. The geometry of the resulting set of training m‐reps is analyzed in non‐Euclidean space using an approach called principal geodesic analysis (PGA) to yield a set of eigenmodes that define the geometric prior. The intensity likelihood is constructed by registering each training m‐rep with the corresponding gray scale image and collecting regional intensity information that is statistically characterized over all training cases. The intensity information can be in several forms including linear profiles and regional histograms. Results: PGA produces modes that include natural deformations such as local twisting, bending, bulging, and constricting. Unlike analysis in Euclidean space, improper shapes are avoided. The form of the intensity prior can be customized to each object of interest for optimal performance. Conclusion: These methods are powerful, robust and generalizable to other DSMs. Conflict of Interest: The presenting author has a financial interest in Morphormics, Inc.
Neutrophils are resistant to Yersinia YopJ/P-induced apoptosis and are protected from ROS-mediated cell death by the type III secretion system.

Background The human innate immune system relies on the coordinated activity of macrophages and polymorphonuclear leukocytes (neutrophils or PMNs) for defense against bacterial pathogens. Yersinia spp. subvert the innate immune response to cause disease in humans. In particular, the Yersinia outer protein YopJ (Y. pestis and Y. pseudotuberculosis) and YopP (Y. enterocolitica) rapidly induce apoptosis in murine macrophages and dendritic cells. However, the effects of Yersinia Yop J/P on neutrophil fate are not clearly defined. Methodology/Principal Findings In this study, we utilized wild-type and mutant strains of Yersinia to test the contribution of YopJ and YopP on induction of apoptosis in human monocyte-derived macrophages (HMDM) and neutrophils. Whereas YopJ and YopP similarly induced apoptosis in HMDMs, interaction of human neutrophils with virulence plasmid-containing Yersinia did not result in PMN caspase activation, release of LDH, or loss of membrane integrity greater than PMN controls. In contrast, interaction of human PMNs with the virulence plasmid-deficient Y. pestis strain KIM6 resulted in increased surface exposure of phosphatidylserine (PS) and cell death. PMN reactive oxygen species (ROS) production was inhibited in a virulence plasmid-dependent but YopJ/YopP-independent manner. Following phagocytic interaction with Y. pestis strain KIM6, inhibition of PMN ROS production with diphenyleneiodonium chloride resulted in a reduction of PMN cell death similar to that induced by the virulence plasmid-containing strain Y. pestis KIM5. Conclusions Our findings showed that Yersinia YopJ and/or YopP did not induce pronounced apoptosis in human neutrophils. Furthermore, robust PMN ROS production in response to virulence plasmid-deficient Yersinia was associated with increased PMN cell death, suggesting that Yersinia inhibition of PMN ROS production plays a role in evasion of the human innate immune response in part by limiting PMN apoptosis.
Gastrin and EGF synergistically induce cyclooxygenase-2 expression in Swiss 3T3 fibroblasts that express the CCK2 receptor.

Over-expression of cyclooxygenase-2 (COX-2) has been demonstrated to be tumorigenic in transgenic mice. Chronic treatment with NSAIDs is chemoprotective for colorectal cancer. Gastrin is a growth factor for gastric mucosa and has been shown to promote proliferation of colorectal cells. Recent studies suggest that COX-2 expression levels could mediate the growth effects of gastrin. Here, we report that gastrin increased PGE2 secretion in Swiss 3T3 cells expressing the CCK2 receptor. Gastrin dose dependently induced COX-2 protein levels in a time dependent manner. COX-2 mRNA levels were rapidly induced by a dose dependent increase in gastrin. Prior treatment of the cells with the CCK2 receptor specific antagonist, L365,260, inhibited gastrin-induced COX-2 protein and mRNA expression. Pretreatment with L364,714, the CCK1 receptor specific antagonist did not block COX-2 induction by gastrin. Inhibition of de novo protein synthesis by cycloheximide did not block COX-2 mRNA induction by gastrin. Also, gastrin-dependent COX-2 expression did not require PKC activity, activation of ERK, or transactivation of EGFR. However, co-stimulation with EGF and gastrin synergistically induced COX-2 protein and mRNA expression and PGE2 secretion. Measurements of COX-2 mRNA stability and COX-2 gene transcription reveal that EGF significantly increased the half-life of COX-2 mRNA with only a slight increase in the COX-2 transcription rate. Conversely, gastrin significantly increased COX-2 gene transcription rates but did not enhance COX-2 mRNA stability. J. Cell. Physiol. 196: 454–463, 2003. © 2003 Wiley-Liss, Inc.
Diagnostic microsatellite markers for the detection of stem rust resistance gene Sr36 in diverse genetic backgrounds of wheat

The wheat stem rust resistance gene Sr36, derived from Triticum timopheevi, confers a high level of resistance against a new race (TTKS, or commonly known as Ug99) and many other races of Puccinia graminis f. sp. tritici. Because Sr36-virulent races exist, breeding for durable resistance would require pyramiding Sr36 with other genes, a process that can be facilitated by DNA markers. The aim of this study was to identify and validate microsatellite markers for the detection of Sr36 in wheat breeding programs. Two populations of 122 F 2 (LMPG × Sr36/9*LMPG) and 112 F 2 (‘Chinese Spring’ × W2691Sr36-1) were evaluated for stem rust reaction. Both populations exhibited distorted segregation with a preferential transmission of the Sr36-carrying segment. Three markers, Xstm773-2, Xgwm319, and Xwmc477, were in complete linkage with Sr36 in the LMPG × Sr36/9*LMPG population. In the Chinese Spring × W2691Sr36-1 population, Xgwm319 was 0.9 cM away from Xstm773-2, Xwmc477, and Sr36. These codominant markers were easy to score and diagnostic for Sr36 in a set of 76 wheat cultivars and breeding lines developed in 12 countries. Together, these markers can be used in marker-assisted selection of Sr36.
Potentiation of Tumor Radioresponse by Combination of Indomethacin with the Hypoxic Cell Radiosensitizer Misonidazole

Our recent investigations have revealed that inhibition of prostaglandins (PGs) in malignant murine tumors by indomethacin (INDO), an inhibitor of PG synthesis, can increase tumor radioresponse (1-3). The increase was manifested in the prolongation of radiation-produced tumor growth delay, increased proportion of mice cured, and delay of onset of postirradiation recurrence. The degree of INDO-induced augmentation of tumor radioresponse ranged from a factor of 1.3 to > 2, which depended on a number of factors including tumor type, choice of fractionation in radiation treatment, timing in INDO administration in relation to tumor irradiation, and the endpoint of tumor response. Our most recent studies (3) showed that this radiopotentiating action is mediated mainly via the antitumor immune mechanisms elicited or augmented by INDO, and not through the elimination or reduction of the hypothetical radioprotective activities of PGs as initially hypothesized (2). In many normal tissues, INDO either has no effect on radioresponse, (2) or it is radioprotective (2,4).
The Modernity of Tradition: The Democratic Incarnation of Caste in India

Marx's century-old socio-political analysis of peasant nations and of India's traditional village and caste society, because it captures so much of contemporary social and political analysis, provides a convenient framework for critical discussion and evaluation of the relationship between traditional society and modern politics in India. Peasant nations such as mid-nineteenth century France, Marx observed in the The Eighteenth Brumaire of Louis Napoleon, are formed “by simple addition of homologous magnitudes, much as potatoes in a sack form a sackful of potatoes.” Objectively, peasants form a class; the mode of life, interests and culture which flow from their productive circumstances separate peasants from other classes and place their class in opposition to other classes. But subjectively and practically, peasants form a vast mass, “the members of which live in similar conditions, but without entering into manifold relations with one another.”
Covert Neurological Symptoms Associated With Silent Infarcts From Midlife to Older Age: The Atherosclerosis Risk in Communities Study

Background and Purpose—Unrecognized or unreported stroke-like symptoms, called covert symptoms, occur in persons free of clinical stroke. Whether covert symptoms are associated with subclinical brain infarcts (SBIs) is unknown. This study examined the association between covert stroke-like symptoms and SBI/stroke in persons with no history of stroke or transient ischemic attack. Methods—A total of 1881 Atherosclerosis Risk in Communities (ARIC) participants free of clinical stroke or transient ischemic attack (40% male, 50% black, 47–70 years) were queried for covert symptoms and underwent cerebral MRI during the baseline MRI visit. Symptoms were reassessed after 3 years at Visit 4 (n=1001; 39% male, 50% black) and approximately 10 years with a follow-up MRI (n=1006; 40% male, 50% black, 61–83 years). Results—Covert symptoms were associated with prevalent SBI (OR, 1.94; 95% CI, 1.21–3.11; P=0.006). No support was found for associations between baseline MRI symptoms and SBI at the follow up MRI visit. In p...
Characterization of complement activity in turkeys: evidence for classical and alternative complement pathways.

Abstract Complement activity in turkey serum was examined by using inhibitors or activators of mammalian complement. Hemolytic test systems using sheep red blood cells sensitized with specific antibody (SSRBC) and horse red blood cells (HRBC) were developed to measure residual complement activity of turkey sera treated with the various inhibitors or activators. Lysis of SSRBC was blocked by treatment with 6-mM EDTA, 10-mM ethylene glycol-bis-βaminoethylether N,N,N′,N′ tetraacetic acid (EGTA), and carrageenan. In contrast, lysis of HRBC was blocked by 6-mM EDTA, but not by 10-mM EGTA or carrageenan. Addition of magnesium to EGTA-chelated serum facilitated the lysis of HRBC but not the lysis of SSRBC. Treatment of serum with zymosan at 1 mg/mL and inulin at 5 mg/mL depleted hemolytic activity against both SSRBC and HRBC, suggesting depletion of components common to both pathways. Differences in the hemolytic activities of sera against SSRBC and HRBC after treatment with the various complement inhibitors and activators demonstrate the presence of two complement pathways in turkeys.
Sensitivity analysis to hardware Trojans using power supply transient signals

Trust in reference to integrated circuits addresses the concern that the design and/or fabrication of the IC may be purposely altered by an adversary. The insertion of a hardware Trojan involves a deliberate and malicious change to an IC that adds or removes functionality or reduces its reliability. Trojans are designed to disable and/or destroy the IC at some future time or they may serve to leak confidential information covertly to the adversary. Trojans are cleverly hidden by the adversary to make it extremely difficult for chip validation processes, such as manufacturing test, to accidentally discover them. This paper investigates a power supply transient signal analysis method for detecting Trojans that is based on the analysis of multiple power port signals. In particular, we focus on determining the smallest detectable Trojan in a set of process simulation models that characterize a TSMC 0.18 um process.
Towards a framework for group-centric secure collaboration

The concept of groups is a natural aspect of most collaboration scenarios. Group-Centric Secure Information Sharing models (g-SIS) have been recently proposed in which users and objects are brought together to promote sharing and collaboration. Users may join, leave and re-join and objects may be added, removed and re-added. Furthermore, objects embodying new intellectual property may be created in the group during collaboration, some of which may flow back to the participating entities. Authorizations may depend on various aspects including time of join and add, the user's role, etc. In this paper, we outline three example scenarios of inter-organizational collaboration. We develop a complete authorization model for one of these scenarios comprising administrative and operational components. We conclude the paper by proposing an initial framework for developing more sophisticated models for inter-organizational collaboration.
Somatosensory cortical mechanisms of feature detection in tactile and kinesthetic discrimination

Neurons in somatosensory cortex of primates process sensory information from the hand by integrating information from large populations of receptors to extract specific features. Tactile neurons in areas 1 and 2 are shown to select features such as contact area, edge orientation, motion across the skin, or direction of movement. Features coded by kinesthetic neurons in areas 3a and 2 relate to joint movement, the joint angle around which the movement occurs, or coordinated postures of the hand and arm. An even higher order cortical cell integrates tactile and kinesthetic information; these "haptic neurons" respond optimally to contact of objects actively grasped in the hand. These global features are coded at the expense of loss of information concerning fine-grained spatial detail.
Class Attendance in College A Meta-Analytic Review of the Relationship of Class Attendance With Grades and Student Characteristics

>> A meta-analysis of the relationship between class attendance in college and college grades reveals that attendance has strong relationships with both class grades (k = 69, N = 21,195, r = .44) and GPA (k = 33, N = 9,243, r = .41). These relationships make class attendance a better predictor of college grades than any other known predictor of academic performance, including scores on standardized admissions tests such as the SAT, high school GPA, study habits, and study skills. Results also show that class attendance explains large amounts of unique variance in college grades because of its relative independence from SAT scores and high school GPA and weak relationship with student characteristics such as conscientiousness and motivation. Mandatory attendance policies appear to have a small positive impact on average grades (k = 3, N = 1,421, d = .21). Implications for theoretical frameworks of student academic performance and educational policy are discussed.
Digital receiver phase meter for LISA

A study of a commercially available digital receiver configured as a phase meter has been performed. The effort was part of the technology development phase of the Laser Interferometer Space Antenna (LISA) mission. LISA requires that phase measurements on the metrology signals be made at a rate of 10 Hz with root power spectral density of 5 /spl mu/cycle//spl radic/Hz over the gravitational wave detection band from 1 mHz to 1 Hz. The phase meter must also contend with heterodyne interferometric signals having superposed Doppler shifts as high as 15 MHz. It is found that the off-the-shelf prototype can fulfil these requirements.
The Role of Tourism in Sustainable Communities

This chapter develops a model through which a dynamic analysis of tourism sustainability can be implemented within the context of broader community development goals. The model focuses on the relationship between tourism and quality-of-life as influenced by impacts on economic, sociocultural, and environmental outcomes. This perspective is similar to triple bottom line (TBL) assessments that add sociocultural and environmental dimensions to the traditional economic bottom line. The role of tourism is first analyzed in a stylized but formal dynamic model that equates the quest for sustainability with the quest for an optimal path to long-term stability where a visitation variable is used to control a single community quality-of-life asset. Principle results of this analysis are then further explored using mathematical planning exercise for a community with explicit sustainability goals and the recognition of its triple bottom line of environmental, social, and economic assets. By combining a TBL approach with a formal dynamic approach toward tourism sustainability, the model provides insights into trade-offs implied in sustainable tourism and suggests general principles for tourism planning.
Yeast cap binding complex impedes recruitment of cleavage factor IA to weak termination sites

Nuclear cap binding complex (CBC) is recruited cotranscriptionally and stimulates spliceosome assembly on nascent mRNAs; however, its possible functions in regulating transcription elongation or termination were not well understood. We show that, while CBC appears to be dispensable for normal rates and processivity of elongation by RNA polymerase II (Pol II), it plays a direct role in preventing polyadenylation at weak termination sites. Similarly to Npl3p, with which it interacts, CBC suppresses the weak terminator of the gal10-Delta56 mutant allele by impeding recruitment of termination factors Pcf11p and Rna15p (subunits of cleavage factor IA [CF IA]) and does so without influencing Npl3p occupancy at the termination site. Importantly, deletion of CBC subunits or NPL3 also increases termination at a naturally occurring weak poly(A) site in the RNA14 coding sequences. We also show that CBC is most likely recruited directly to the cap of nascent transcripts rather than interacting first with transcriptional activators or the phosphorylated C-terminal domain of Pol II. Thus, our findings illuminate the mechanism of CBC recruitment and extend its function in Saccharomyces cerevisiae beyond mRNA splicing and degradation of aberrant nuclear mRNAs to include regulation of CF IA recruitment at poly(A) selection sites.
Issues of causality in the history of occupational epidemiology

Occupational epidemiology has its roots in classical medicine. However, it became a quantitative discipline only in the 20th century, through the pioneering work of individuals such as Case, Lloyd, and Selikoff and organizations such as the Division of Occupational Health of the U.S. Public Health Service. Studies of chemical dye workers, bituminous coal miners, smelting workers, and uranium miners have been especially important sources of innovations in methodology and in development of logical reasoning leading to acceptance of causal relationships of occupational exposures that lead to respiratory diseases and cancer. The cooperation of labor unions, such as those of steel and asbestos workers, has often been a crucial factor in providing essential data.
Rarefied Gas Dynamics

The current state of those aspects of rarefied gas dynamics research that appear to be most important to research planned over the next decade is evaluated. These aspects encompass assessments of computational rarefied-gas dynamics (CRGD) that will allows their use as surrogates for experiments, the development of hybris-flowfield computational techniques matching continuum computations with particle computations, and the validation of CRGD through the results of experimental studies of Knudsen layers in simple flows. The design of surfaces for the achievement of stable, low-momentum and thermal accommodation coefficients will be a major priority, together with theorization and experimentation on evaporation and condensation effects close to surfaces.
Potential role of surface wettability on the long-term stability of dentin bonds after surface biomodification

Degradation of the adhesive interface contributes to the failure of resin composite restorations. The hydrophilicity of the dentin matrix during and after bonding procedures may result in an adhesive interface that is more prone to degradation over time. This study assessed the effect of chemical modification of the dentin matrix on the wettability and the long-term reduced modulus of elasticity (Er) of adhesive interfaces. Human molars were divided into groups according to the priming solutions: distilled water (control), 6.5% Proanthocyanidin-rich grape seed extract (PACs), 5.75% 1-ethyl-3-[3-dimethylaminopropyl] carbodiimide hydrochloride/1.4% n-hydroxysuccinimide (EDC/NHS) and 5% Glutaraldehyde (GA). The water-surface contact angle was assessed before and after chemical modification of the dentin matrix. The demineralized dentin surface was treated with the priming solutions and restored with One Step Plus (OS) and Single Bond Plus (SB) and resin composite. Er of the adhesive, hybrid layer and underlying dentin was evaluated after 24h and 30 months in artificial saliva. The dentin hydrophilicity significantly decreased after application of the priming solutions. Aging significantly decreased Er in the hybrid layer and underlying dentin of control groups. Er of GA groups remained stable over time at the hybrid layer and underlying dentin. Significant higher Er was observed for PACs and EDC/NHS groups at the hybrid layer after 24h. The decreased hydrophilicity of the modified dentin matrix likely influence the immediate mechanical properties of the hybrid layer. Dentin biomodification prevented substantial aging at the hybrid layer and underlying dentin after 30 months storage.
Scientific Skateboarding and Mathematical Music: Edutainment that Actively Engages Middle School Students

Edutainment has recently been a major growing area of education, showing great promise to motivate students with relevant activities. The authors are among innovators who have developed cutting-edge fusions of popular culture and STEM concepts to engage and to motivate middle school students, using vehicles such as music/song and skateboarding. The importance of using relevant and practical methods of instruction and curriculum delivery that build on student interests and increase enjoyment in the learning process are critical at the middle school level, especially in the STEM fields. The use of edutainment in this manner is meant to inspire broader interest in mathematics and science for middle school students and to develop a culture of education that makes learning more accessible to all students. This paper surveys and illustrates the use of such immersive modalities to involve middle school students actively with concepts and suggests further directions for the use of demonstrations and videos in educational settings.
Effect of spatial configuration on motion aftereffects

Sensitivity to motion was measured by the percentage of trials on which an observer reported seeing motion of briefly presented high-contrast sinusoidal gratings moving over a range of velocities. The psychometric curve was remeasured following adaptation to a grating moving in one direction for an extended period of time. Adaptation shifted the minimum of the psychometric curve toward the direction of the adapting stimulus. The shift was smaller when the adapting field was larger than the test. In a second set of experiments we measured the effect of motion adaptation on contrast thresholds for moving gratings of different sizes. Threshold elevation was maximal when adapting and test sizes matched. We present a mechanistic model of the motion aftereffect that consists of independent multiplicative gain controls in motion-sensing mechanisms tuned to different rates of motion. In addition, we discuss a model of size effects in motion adaptation that invokes diffuse inhibitory connections among motion-sensing mechanisms.
Experimental prediction of the natural evolution of antibiotic resistance.

The TEM family of β-lactamases has evolved to confer resistance to most of the β-lactam antibiotics, but not to cefepime. To determine whether the TEM β-lactamases have the potential to evolve cefepime resistance, we evolved the ancestral TEM allele, TEM-1, in vitro and selected for cefepime resistance. After four rounds of mutagenesis and selection for increased cefepime resistance each of eight independent populations reached a level equivalent to clinical resistance. All eight evolved alleles increased the level of cefepime resistance by a factor of at least 32, and the best allele improved by a factor of 512. Sequencing showed that alleles contained from two to six amino acid substitutions, many of which were shared among alleles, and that the best allele contained only three substitutions.
Factors associated with failure-to-rescue in patients undergoing trauma laparotomy

Introduction Quality improvement initiatives have focused primarily on preventing in-hospital complications. Patients developing complications are at a greater risk of mortality; however, factors associated with failure-to-rescue (death after major complication) in trauma patients remain undefined. The aim of this study was to identify risk factors associated with failure-to-rescue in patients undergoing trauma laparotomy. Methods An -8-year, retrospective analysis of patients undergoing trauma laparotomy was performed. Patients who developed major in-hospital complications were included. Major complications were defined as respiratory, infectious, cardiac, renal, or development of compartment syndrome. Regression analysis was performed to identify independent factors associated with failure-to-rescue after we adjusted for demographics, mechanism of injury, abdominal abbreviated injury scale, initial vital signs, damage control laparotomy, and volume of crystalloids and blood products administered. Results A total of 1,029 patients were reviewed, of which 21% (n = 217) patients who developed major complications were included. The mean age was 39 ± 18 years, 82% were male, 61% had blunt trauma, and median abdominal abbreviated injury scale was 25 [16–34, interquartile range]. Respiratory complications (n = 77) followed by infectious complications (n = 75) were the most common complications. The failure-to-rescue rate was 15.7% (n = 34/217). Age, blunt trauma, severe head injury, uninsured status, and blood products administered on the second day were independent predictor for failure-to-rescue. Conclusion When major complications develop, age, uninsured status, severity of head injury, and prolonged resuscitation are associated independently with failure-to-rescue, whereas initial resuscitation, coagulopathy, and acidosis did not predict failure to rescue. Quality-of-care programs focus in patient level should be on improving the patient's insurance status, preventing secondary brain injury, and further development of resuscitation guidelines.
Iterafive Nonlinear Inversion Methods for Tomographic Problems

Abstract The application of nonlinear iterafive algorithms to two-dimensional tomographic reconstructions is discttszed and a number of numerical examples are given, using as an illustrative basis reconstruction of the spatial distribution of liquid water in clouds from measurements of microwave attenuation. (The method, however, is not restricted to that specific problem and appears to be especially suitable for inversions involving a large number of unknowns.)
Quantum States of an Electron Interacting with Various Dielectric Plate Geometries

The tunability of binding energies is explored by modulating a finite dielectric slab width in a planar, three dielectric system. After verifying the equivalence of the field method and method of images, three different configurations are explored for possible control of electronic binding energy: A vacuum gap between a Schottky diode, noble gas layers on a metal wall, and an electron confined between two metal plates. In each, varying the width of the finite, middle dielectric was shown to provide control over the binding energy and Bohr radius of the electron. In the case of an electron confined between two plates, it was found that the bound states smoothly connect to the box states as the gap separation was varied. Lastly, forces on the two parallel plates were examined for a possible source of significant repulsion. All numerical calculations were done in MATLAB.
Using regression for spectral estimation of HMMs

Hidden Markov Models (HMMs) are widely used to model discrete time series data, but the EM and Gibbs sampling methods used to estimate them are often slow or prone to get stuck in local minima. A more recent class of reduced-dimension spectral methods for estimating HMMs has attractive theoretical properties, but their finite sample size behavior has not been well characterized. We introduce a new spectral model for HMM estimation, a corresponding spectral bilinear regression model, and systematically compare them with a variety of competing simplified models, explaining when and why each method gives superior performance. Using regression to estimate HMMs has a number of advantages, allowing more powerful and flexible modeling.
Late Results after Meniscectomy

Two hundred thirteen patients with uncomplicated meniscus injuries were studied from ten to thirty years after their meniscectomy in order to determine the late effects of surgery. Delay of operation after injury did not affect the ultimate result. Patients less than twenty years old at the time of operation had fewer excellent and good results. The diagnosis is more difficult, and the benefit of meniscectomy is less certain, in women than in men. There was no difference in results between total and partial meniscectomy except in bucket-handle tears. Leaving the peripheral rim intact in uncomplicated bucket-handle tears produced the most excellent results. Persistence in a physical occupation or participation in non-contact sports seems not to alter the course after meniscectomy. It was usually, but not invariably, possible to correlate roentgenographic appearance with the clinical result. The meniscectomy site was readily apparent in ninety-four of 110 patients (85 per cent). Sixty-eight per cent of patients in our series had satisfactory clinical results, but only 45 per cent of men and 10 per cent of women had symptom-free knees.
Farmer Ted Goes 3D

In his recent paper entitled "Farmer Ted Goes Natural" [2], Greg Martin discusses the plight of Farmer Ted, who wants to minimize the cost of chicken wire to enclose a rectangular coop with a base of 190 square feet. However, Farmer Ted has difficulty purchasing 4,j56 feet of chicken wire because he is only able to purchase wire in integer lengths. After much deliberation, he decides to build an 11 foot x 17 foot coop (187 square feet), which has the best cost-efficiency of any possible coop with integer side lengths and area 190 square feet. Here we add another dimension to the story of Farmer Ted. In recent years, Farmer Ted has helped numerous neighbors efficiently build chicken coops. Then one local farmer asked a question that intrigued him: The farmer wants to build an animal cage with a volume of up to 50 cubic feet. What is the most cost-effective way to do this with integer side lengths? Farmer Ted had begun to think in 3D. Before analyzing the three-dimensional problem, we should briefly review some of Martin's work. He starts with the basic calculus optimization problem of finding the minimum perimeter of a rectangle given a fixed area. As many students know, the optimal shape is a square. Martin then offers this variation: Given a positive integer N, what are the dimensions of the rectangle with integer side lengths and area at most N whose area-to-perimeter ratio is largest among all such rectangles? In order to solve this problem, Martin makes the following definitions: Let s(n) = min (c d) where cd =n and c, d E N. Equivalently, s(n) = min (d nld) where d I n. This gives the minimum semiperimeter, or half of the actual perimeter, of a rectangle with area n with integer sides. Define F (n) = n /s (n), which is the maximum ratio of area to semiperimeter for a given n. (Using this expression, which is twice as large as the maximum ratio of area to perimeter, is more aesthetically pleasing and does not change the analysis.) Farmer Ted prefers to enclose 187 ft.2 rather than 190 ft.2 because F(187) = 187/28 > F(190) = 190/29. This leads Martin to identify the set