cssi/SciSciGPT-SciSciNet huggingface dataset:
Source–receptor relationships for atmospheric mercury in urban Detroit, Michigan

Speciated hourly mercury measurements were made in Detroit, Michigan during four sampling campaigns from 2000 to 2002. In addition, other chemical and meteorological parameters were measured concurrently. These data were analyzed using principal components analysis (PCA) in order to develop source receptor relationships for mercury species in urban Detroit. Reactive gaseous mercury (RGM) was found to cluster on two main factors; photochemistry and a coal combustion factor. Particulate phase mercury, Hgp, tended to cluster with RGM on the same factor. The photochemistry factor corroborates previous observations of the presence of RGM in highly oxidizing atmospheres and does not point to a specific source emission type. Instead, it likely represents local emissions and regional transport of photochemically processed air masses. The coal combustion factor is indicative of emissions from coal-fired power plants near the receptor site. Elemental mercury was found on a factor for combustion from automobiles and points to the influence these emissions have on the receptor site, which was located proximate to two major interstate highways and the largest border crossing in the United States. This analysis reveals that the receptor site which is located in an industrialized sector of the city of Detroit experienced impacts from both stationary and point sources of mercury that are both local and regional in nature.
Auxiliary ghost fields in statistical dynamics

The path integral formulation of statistical dynamics involves a functional determinant whose role within the theory has remained somewhat unclear. This has occasionally led to incorrect generalizations of the formalism to the case of multiplicative random forces. We present a hidden symmetry of the theory and show how it can be used to clarify these issues. Important further applications are also pointed out.
The clinical response to total sleep deprivation and recovery sleep in geriatric depression: potential indicators of antidepressant treatment outcome

The clinical response to antidepressant treatment in late-life depression is often delayed and highly variable. Better indicators of antidepressant efficacy are needed early in the course of treatment, so that augmentation strategies or alternative treatments may be initiated. The goal of this study was to evaluate whether the change in the Hamilton depression rating scale (HDRS) after 36 h of total sleep deprivation (TSD) and recovery sleep predicted clinical outcome after 12 weeks of antidepressant treatment, and whether greater predictive value was observed in certain aspects of depressive symptomology. Fifteen elderly patients diagnosed with major depression underwent combined treatment with an initial 36 hours of TSD and a 12-week trial with the antidepressant paroxetine. Six HDRS subscores were evaluated with respect to how the changes after TSD and after one night of recovery sleep correlated with HDRS scores after 12 weeks of treatment. A significant correlation was obtained between the change in the core depressive symptomology subscale from baseline to recovery sleep and the HDRS score at 12 weeks, but the correlation was not significant when evaluating the change from baseline to TSD. These results indicate that the decrease in symptoms after recovery sleep compared with baseline levels (indicating the persistence of the antidepressant response), rather than the symptom reduction after TSD, has greater predictive value with respect to treatment outcome.
PROTECTION OF CHLOROPHYLL a BY CAROTENOID FROM PHOTODYNAMIC DECOMPOSITION

— The order of inhibition of the photooxidation of chlorophyll a in ethanol and ethanol-benzene is as follows: β-carotene, α-tocopherol, benzoquinone, DABCO, menadione, cholesterol and KI. The quenching of singlet oxygen by β-carotene occurs by a collisional quenching mechanism with a diffusion-controlled rate of 1.7 × 1010M-1 s-1. Photodecomposition of Chi a is faster in ethanol-D2O than in ethanol-H2O. Photoirradiation (660 nm) of the peridinin-Chl a-protein complex, a photosynthetic light-harvesting pigment isolated from marine dinoflagellates, did not show any photo-decomposition of its Chi a in H2O or D2O, even after an extended period (12 h) of irradiation. However, the carotenoid, peridinin, in the photosynthetic antenna pigment was photobleached (ca. 10%) during the irradiation. We conclude that the singlet oxygen formed as a result of the Chi photosensitization is immediately quenched by the low-lying triplet state of four peridinin molecules (per Chl a) bound within the same protein crevice. The carotenoid thus effectively protects Chl a from photodynamic damage, providing a direct proof for the protective role of carotenoids in the photosynthetic pigment complex.
Renin as a risk factor for atherogenesis. Part 2. Effects of hypercholesterolemia and hyporeninemia in the rabbit.

Four groups of New Zealand rabbits were used to study the effect of suppressed plasma renin activity (PRA) on atherogenesis. Control groups were fed normal rabbit chow (Group I) or normal chow supplemented with 0.25% cholesterol-0.75% corn oil (Group III). Group II animals were fed normal chow and received periodic injections of 11-desoxycorticosterone (DOC)pivalate and 0.5% saline to drink, while Group IV animals were treated similarly except that they were also fed the atherogenic diet. Blood pressure and blood chemistry measurements were performed monthly over a 7-month period. The blood pressure was unaffected by either the diet or the DOC-saline treatment, however, the PRA was greatly reduced in the animals receiving DOC-saline (Groups II and IV). Similarly, plasma aldosterone was significantly (P < 0.05) reduced in the DOC-saline-treated animals. No atheromata were observed in the animals consuming the regular diet, regardless of DOC-saline treatment. All of the animals fed the atherogenic diet showed extensive aortic atheromata. However, there was no difference in the lesion index between the animals with normal PRA levels (Group III) and those with suppressed PRA levels (Group IV). Likewise, microscopic evaluation of the aorta, coronary arteries, and renal arteries failed to show a consistent difference in the vascular involvement between animals of Groups III and IV. We therefore conclude that the suppression of PRA does not have a protective effect on atherogenesis in the cholesterol-fed normotensive rabbit.
Two Polo-like kinase 4 binding domains in Asterless perform distinct roles in regulating kinase stability

Plk4 (Polo-like kinase 4) and its binding partner Asterless (Asl) are essential, conserved centriole assembly factors that induce centriole amplification when overexpressed. Previous studies found that Asl acts as a scaffolding protein; its N terminus binds Plk4’s tandem Polo box cassette (PB1-PB2) and targets Plk4 to centrioles to initiate centriole duplication. However, how Asl overexpression drives centriole amplification is unknown. In this paper, we investigated the Asl–Plk4 interaction in Drosophila melanogaster cells. Surprisingly, the N-terminal region of Asl is not required for centriole duplication, but a previously unidentified Plk4-binding domain in the C terminus is required. Mechanistic analyses of the different Asl regions revealed that they act uniquely during the cell cycle: the Asl N terminus promotes Plk4 homodimerization and autophosphorylation during interphase, whereas the Asl C terminus stabilizes Plk4 during mitosis. Therefore, Asl affects Plk4 in multiple ways to regulate centriole duplication. Asl not only targets Plk4 to centrioles but also modulates Plk4 stability and activity, explaining the ability of overexpressed Asl to drive centriole amplification.
Helping the CD8 + T-cell response

Cytotoxic T lymphocytes (CTLs) that express the CD8 co-receptor are the guided missiles of the immune system. They express clonally distributed receptors for foreign antigen, undergo marked proliferation in response to infection and kill any cell that expresses their target antigen. When an infection is cleared or brought under control, the progeny of these cytolytic effectors are retained as an essential component of immunological memory. As I discuss here, similar to other aspects of immunity, their clonal expansion and survival depend on the activity of CD4+ T cells, although the mechanism(s) of 'help' for CTL responses is still debated.
Changing principals’ leadership through feedback and coaching

Purpose – In this study the authors use longitudinal data from a randomized experiment to investigate the impact of a feedback and coaching intervention on principals’ leadership behaviors. The paper aims to discuss these issues. Design/methodology/approach – In total, 52 elementary and middle school principals (26 receiving teacher feedback, 26 receiving feedback and coaching) were randomized into a year-long feedback and coaching study. Measures of leadership actions were collected from principals and teachers during the fall, winter, and spring. The authors use instrumental variables approach to examine the impact of treatment. Findings – Behavioral change may take longer than is presented in this study, which implies that these findings represent a lower-bound. As an intervention leadership coaching is costly and this research does not explore alternatives to help principals make feedback data actionable. Practical implications – It is unlikely that providing school leaders with feedback alone will in...
A New Concept of the Mechanical Behavior of Fibers

The first portion, Part I, of this paper presents a review of the various theories of mechanical behavior of fibers. It is shown that the linear three-element model gives a fairly good qualitative description of relaxation, creep, and stress-strain phenomena. With this linear model extended to give a dis tribution of relaxation times, the time scales of the relaxation and creep functions are expanded to ranges which approach those observed experimentally. However, the more compli cated linear model is cumbersome, particularly when used to explain stress-strain data, and it does not yield the proper values of the elastic and viscous constants when the rate of strain is changed by a large factor. The three-element model with Hookean springs and Eyring dashpot is discussed, and it is shown that it accomplishes the extension of the time scale for relaxation and creep, and also yields relationships involving changes in the rate of elongation of stress-strain experiments which agree quite well with data on acet...
Acoustic systems containing curved duct sections

The analysis of waves in curved ducting of rectangular cross section is extended to the study of motion near discontinuities. This includes determination of the characteristics of the tangential and radial components of the nonpropagating modes, It is established that attenuation of the nonpropagating modes strongly depends on frequency and that, in general, the sharper the bend, the less attenuation may be expected. Evaluation of a bend's impedance and of impedance‐generated reflections is also presented in detail.
A possible dual physiological role of extracellular ATP in the modulation of platelet aggregation.

Abstract ATP and ADP are simultaneously released from activated platelets in equimolar concentrations. Micromolar concentrations of ATP inhibit platelet aggregation by both competitive and non-competitive mechanisms. The current studies addressed the question of how platelets respond to agonists in the presence of nanomolar and micromolar concentrations of ATP and ADP alone or in combination. This is a significant issue since the concentration of ATP±ADP may vary widely within a microenvironment depending upon the source and cause for the release of the nucleotides. ATP (1–10 nM) was found to significantly enhance the thromboxane A 2 analog, U44619-, collagen- and thrombin-induced platelet aggregations. Conversely, ATP at 1–100 μ M inhibited these same reactions. ADP, in general, behaved exactly opposite to ATP. When equal amounts of ATP and ADP were added together the ADP response appeared to predominate. The observed ATP-induced response was not due to a hydrolytic product as evidenced by an unaltered response to ATP in the presence of adenosine deaminase or the ATP generating system, creatine phosphate plus creatine phosphokinase. Adenosine (1–10 nM), like ADP, inhibited agonist-induced platelet aggregation. The stimulation of agonist-induced platelet aggregation by 1–10 nM extracellular ATP appears to depend upon the phosphorylation of platelet membrane ecto proteins. The ATP analog, βγ -methylene ATP, that is incapable of serving as a phosphate donor for protein kinases, inhibited rather than stimulated agonist-induced platelet aggregation. The dual response of platelets to low and high concentrations of extracellular ATP±ADP may play a physiological role in hemostasis and thrombosis under normal and pathological conditions.
A scanning dual wavelength spectrophotometer: Application to the study of photosynthetic electron transport☆

Abstract A dual wavelength scanning spectrophotometric method for the analysis of small absorbance changes in turbid suspensions is presented, which improves upon the point by point method of obtaining difference spectra in terms both of accuracy and rapidity. Examples are shown of the application of this instrument, in conjunction with a computer curve-resolving routine, to problems in photosynthetic electron transport.
Augmentation of murine natural killer cell activity by manganese chloride.

Abstract Natural killer (NK) cell activity of spleen cells from male CBA J mice was augmented by a single parenteral injection of MnCl2 administered 1 day prior to testing by in vitro and in vivo isotope release assays. Increased cytotoxic activity was observed in vitro against both NK-sensitive (YAC-1) and NK-resistant (EL-4) target cells. NK activity was also enhanced in normally low ( A J ) and intermediately ( C57B1 6J ) reactive strains of mice. Augmentation of NK activity by MnCl2 was accompanied by an increase in circulating interferon (IFN) levels.
Minitack: Software Agents and Semantic Web Technologies

The Semantic Web seeks to extend the World Wide Web from a web for human users into a web for Software Agents as well, where Software Agents provide a powerful assist to the human users. Before a ubiquitous and Software Agent-enabled Semantic Web can be realized, there are a number of challenging issues in a number of divergent disciplines that must be solved. How can we better gather, fuse, interpret, analyze, and visualize information stored on the Web? How can we provide a rapid and profound understanding of the information that is available on the Web?
Gabapentin, Valproic Acid, and Ethanol Intoxication: Elevated Blood Levels with Mild Clinical Effects

Case Report: A suicidal, epileptic patient ingested ethanol, valproic acid, and gabapentin, a new antiepileptic drug. He did well clinically despite elevated blood gabapentin, valproic acid, and ethanol. Conclusions: Preliminary data from this case and one previous report indicate relatively mild clinical signs and symptoms with gabapentin poisoning.
Three-dimensional display in nuclear medicine

Several surface and volume rendering techniques are compared using nuclear medicine data including several new methods developed by the authors specifically for scintigraphic data. The techniques examined are summed projection, thresholded projection, threshold-based surface illumination, volumetric compositing, maximum-activity projection, sun-weighted maximum-activity projection, and variable attenuation. The advantages and disadvantages of each method are discussed in relation to the goals of three-dimensional display, which are defined herein. Selected images are shown to illustrate the usefulness of the methods. >
Mixed Messages: How Primary Agents of Socialization Influence Adolescent Females Who Identify as Multiracial-Bisexual.

The goals of this study were to highlight the often stigmatized and invisible identities of six female participants who identify as multiracial/biracial–bisexual/pansexual, focusing on the pre-college context. Findings, using in-depth interviews, indicated that the primary socializing agents within the pre-college context strongly influenced racial and sexual labels and whether participants integrated their identities or kept them separate. In addition, distance from significant others, in college, spurred further identity development. The findings are exploratory but highlight the relevance of socializing agents on adolescent identity development and the need for continued global support for individuals with multiple, marginal, fluid identities.
How Cyclic Loading Affects the Migration of Radio-Opaque Markers Attached to Tendon Grafts Using a New Method: A Study Using Roentgen Stereophotogrammetric Analysis (RSA)

An increase in anterior laxity following reconstruction of the anterior cruciate ligament (ACL) can result from lengthening of the graft construct in either the regions of fixation and/or the region of the graft substance between the fixations. RSA could be a useful technique to determine lengthening in these regions if a method can be devised for attaching radio-opaque markers to soft tissue grafts so that marker migration from repeated loading of the graft is limited. Therefore, the objectives of this study were 1) to develop a method for attaching radio-opaque markers to an ACL graft that limits marker migration within the graft, 2) to characterize the error of an RSA system used to study migration, and 3) to determine the maximum amount of migration and the time when it occurs during cyclic loading of ACL grafts. Tendon markers were constructed from a 0.8-mm tantalum ball and a stainless steel suture. Ten double-looped tendon grafts were passed through tibial tunnels drilled in bovine tibias and fixed with a tibial fixation device. Two tendon markers were sewn to one tendon bundle of each graft and the grafts were cyclically loaded for 225,000 cycles from 20 N to 170 N. At specified intervals, simultaneous radiographs were obtained of the tendon markers and a radiographic standard of known length. The bias and imprecision in measuring the length of the radiographic standard were 0.0 and 0.046 mm respectively. Marker migration was computed as the change in distance between the two tendon markers along the axis of the tibial tunnel. Marker migration was greatest after 225,000 cycles with a root mean square (RMS) value of less than 0.2 mm. Because the RMS value indicates the error introduced into measurements of lengthening and because this error is small, the method described for attaching markers to an ACL graft has the potential to be useful for determining lengthening of ACL graft constructs in in vivo studies in humans.
Safety Evaluation of Hybrid Main-Line Toll Plazas

Traditional main-line toll plazas on expressways may have both safety and operational challenges. Although many studies have demonstrated the operational and environmental impacts of conversion from traditional toll plazas to a barrier-free system (open road tolling), research that quantifies the safety benefits of new tolling systems is lacking. This study evaluated the safety effectiveness of the conversion from a traditional main-line toll plaza design to a hybrid main-line toll plaza (HMTP) system. An HMTP system combines both open road tolling on the main line and separate traditional toll collection to the side. Various observational before-after studies were applied on 98 main-line toll plazas (two directions) located on approximately 750 mi of toll roads in Florida; 30 of these were upgraded to the HMTP system. The multivariate empirical Bayes method produced the best crash modification factors with low standard errors, and its results indicated that the conversion from traditional main-line toll ...
Lower Pleistocene to present structural deformation and sequence stratigraphy of the continental shelf, offshore Eel River Basin, northern California

Seismic stratigraphic sequences and deformational features are mapped beneath the continental shelf of the offshore Eel River Basin of northern California, using a closely spaced, high-resolution multichannel seismic grid. Geometries of sequences and morphologies of bounding unconformities reflect competing tectonic and glacioeustatic influences, producing shifting sedimentation patterns in the offshore basin during the last V1 Myr. Estimated timing of unconformity formation correlates generally with a deep-ocean global N 18 O curve, both before and after a V500kyr transition from 41-kyr to 100-kyr dominated cycles. We suggest that glacioeustatic fluctuations are the dominant control on unconformity formation basinwide. However, regional tectonic influences on sequence development are also observed. Folding associated with Gorda^North America Plate convergence ended progressively from south to north between V1.0 Ma and V500 ka, in response to northward migration of the Mendocino Triple Junction (MTJ). Since V500 ka, continued encroachment of the MTJ produces rotation of preexisting structures, uplift of the Table Bluff Anticline (TBA), related periods of channel incision south of the TBA, and generally reduced sediment preservation across the shelf. MTJ-related uplift may also have induced formation of Eel Canyon. Over the past V1.0 Myr, a dominant northern sediment source becomes progressively less important; a southern source, probably the paleo-Eel River, has become dominant since V750 ka. Seismic unconformities fall into two categories: (1) irregular surfaces of limited mappable extent, interpreted as incision/exposure surfaces forming during relative sea-level lowstands, and (2) smooth, laterally extensive regional unconformities, interpreted as ravinement surfaces that erode lowstand surfaces in all but deeply incised areas during sea-level transgressions. A sequence stratigraphic model for sediment deposition and preservation on the Eel River shelf predicts that preserved sediment on the Eel margin is dominated by fluvially derived highstand silts and muds, deposited by longshore-directed currents and waves. Lowstand sediments are preserved only in fluvial channels infilled during late lowstand/early transgression. Preserved transgressive sediments are likely limited to a thin veneer of well-sorted coarse sediment or shell debris, deposited above the transgressive ravinement. Future deep coring will be required to confirm these predictions. ; 2002 Elsevier Science B.V. All rights reserved.
Interactions Among Drugs, Alcohol, and Violence

Prologue: Recent studies have determined that more than half of all homicides in this country involve drugs or alcohol; furthermore, alcohol and drugs are implicated in an even larger proportion of nonfatal violent acts. Given the public health community's increased interest in violence and its toll on society, the linkage between substances and violence seems a logical next step. Indeed, as Jeffrey Fagan writes in this paper, hundreds of complex interactions exist among these phenomena. While experts agree that drugs and alcohol often play a role in violent activities, their precise role is less clear. Here Fagan discusses the limitations and dilemmas of current research into interactions among drugs, alcohol, and violence, based on an expanding literature in this field. Several issues in law and social science “complicate efforts to explain the relationships between substance use and interpersonal violence,” Fagan writes. These issues include the inability to establish firm causation in substance-relate...
Tobacco industry tactics

The tobacco industry's strong-arm tactics have been used consistently over many years.These tactics include: using the industry's size, wealth, and legal resources to intimidate individuals and local governmental bodies; setting up'front groups'to make it appear that it has more allies than it really does; spending large sums of money to frame the public debate about smoking regulations around 'rights and liberty'rather than health and portraying its tobacco company adversaries as extremists; 'investing'thousands of dollars in campaign contributions to politicians; and using financial resources to influence science.These tactics are designed to produce delay, giving the nicotine cartel more time to collect even more profits at the direct expense of millions of lives around the world. In the field of public policy, the tobacco industry has a long and usually successful track record in influencing legislators and other decisionmakers. This is especially true at the national or state level; while the industry has engaged in battles in cities and towns, its rate of success is notably poorer as they go closest to the people. Thus, the tobacco industry turns to one of its favorite strategies — pre-emption. In effect, the lesson to be learned is this: if you can't win at a particular level of government, then make that level of government irrelevant by taking away its power to act. So, in 1994, after years of watching California communities pass and implement tough local laws requiring smoke-free public places, including restaurants, the tobacco industry poured over $18 million into a campaign to sponsor its pre-emption proposal and to collect the necessary signatures to put the proposal on the November ballot as a binding referendum. And in its efforts to obtain signatures for its effort to pre-empt local laws, Philip Morris falsely persuaded potential signers that its goal was to achieve a law to restrict smoking in public. California's Secretary of State, Anthony Miller, accused Philip Morris's front group — called Californians for Uniform Statewide Restrictions (CUSR) — of outright deception. CUSR made no mention of its tobacco connections. 'A great many signers have been duped, and they are furious and I don't blame them. Don't be fooled by petitions sponsored by the tobacco industry,' said Miller1.
Idiosyncratic drug-induced liver injury and the role of inflammatory stress with an emphasis on an animal model of trovafloxacin hepatotoxicity

Idiosyncratic adverse drug reactions (IADRs) occur in a minority of patients yet account for the majority of postmarketing use restrictions by the Food and Drug Administration. Despite the impact of these toxicities, the underlying mechanisms are still poorly understood. Animal models of IADRs would be beneficial in understanding mechanisms and in developing assays with predictive potential. Recent work exploring the interactions between inflammatory stress and drugs associated with human idiosyncratic drug-induced liver injury (IDILI) has led to the development of the first animal models that apply to a range of drugs. Here, we discuss hypotheses for the mechanisms of IDILI and focus on a murine model of trovafloxacin-induced hepatotoxicity as an example related to the inflammatory stress hypothesis.
Toward a test battery for differential categorization of age-related hearing loss

Age-related hearing loss (ARHL, or presbycusis) results from neural and/or cochlear degeneration. A taxonomy distinguishing presbycusis subtypes according to site of lesion was originally proposed by linking audiometric results to histopathological findings. In most cases, the pathology is complex and audiometry and word recognition scores (WRS) are insufficient to characterize pathologies of the auditory periphery. Several sophisticated tests of auditory function, with some specifically designed to inspect cochlear or neural status (e.g., distortion product otoacoustic emissions [DPOAEs] and auditory brainstem response [ABR]) are available but not in routine use to distinguish between presbycutic subtypes. There are no in vivo methods in place to identify contributing pathologies and their relative dominance in individual instances of presbycusis. However, the promise of upcoming therapies (genetic, pharmaceutical, etc.) cannot be realized without accurate identification of presbycusis subtypes. The goal of the present study was to investigate possible improvements in differential categorization of presbycutic subtypes. We explored a test battery composed of behavioral (audiometry and speech testing) and physiological (ABR, DPOAEs, and electrocochleography) assays in presbycutic ears to ask if improvements beyond the gold standard (behavioral thresholds through 8 kHz and word recognition) are possible. Data from 10 hearing impaired (HI) individuals were compared to those from 21 normal hearing (NH) adults. Exploratory factor and hierarchical cluster analyses (EFA and HCA respectively) were used to evaluate phenotyping strategies. The EFA revealed three factors (highest audible frequency (HAF), pure-tone average (PTA), and 2f 1 -f 2(High) DPOAEs) that accounted for most of the variability in hearing outcomes among the 31 participants. Hierarchical cluster analysis using the gold standard and enhanced multivariate approach revealed: (1) The clinical gold standard distinguished NH and HI participants, but failed to find commonalities among individuals with similar hearing profiles and (2) The enhanced test battery grouped participants with similar profiles, presumably indicating an underlying relationship in pathophysiology. Model data support the feasibility of a finer-grained categorization of presbycusis than is available in current practice, although more data are needed to understand the complexities of phenotyping.
ASYMPTOTICS FOR THE LOW‐FREQUENCY ORDINATES OF THE PERIODOGRAM OF A LONG‐MEMORY TIME SERIES

. We consider the asymptotic distribution of the normalized periodogram ordinates I(ωj)/f(ωj) (j= 1,2,…) of a general long-memory time series. Here, I(ω;) is the periodogram based on a sample size n, f(ω) is the spectral density and ωj= 2πj/n. We assume that n∝ with j held fixed, and so our focus is on low frequencies; these are the most important frequencies for the periodogram-based estimation of the memory parameter d. Contrary to popular belief, the normalized periodogram ordinates obtained from a Gaussian process are asymptotically neither independent identically distributed nor exponentially distributed. In fact, limn E{I(ωj)/f(ωj)} depends on both j and d and is typically greater than unity, implying a positive asymptotic relative bias in I(ωj) as an estimator of f(ωj). Tapering is found to reduce this bias dramatically, except at frequency ω1. The asymptotic distribution of I(ωj)/f(ωj) for a Gaussian process is, in general, that of an unequally weighted linear combination of two independent X21 random variables. The asymptotic mean of the log normalized periodogram depends on j and d and is not in general equal to the negative of Euler's constant, as is commonly assumed. Consequently, the regression estimator of d proposed by Geweke and Porter-Hudak will be asymptotically biased if the number of frequencies used in the regression is held fixed as n∝.
Effect of proteoglycan removal on solute mobility in articular cartilage.

Abstract Transport of nutrients, cytokines, pharmacologic agents, and matrix components through articular cartilage is critical for the viability and structural integrity of the tissue. To understand the role of the extracellular matrix in regulating this process, we measured the diffusivity of three uncharged solutes of different molecular size (glucose, MW 180; inulin, MW 5000; dextran, MW 70,000) into intact cartilage and cartilage that had its proteoglycan (PG) component removed. Solute diffusivity was measured by performing transient (nonsteady state) one-dimensional diffusion tests using radiolabelled solutes. Compared to intact cartilage, the diffusivity of glucose was unchanged after PG removal, inulin was unchanged but dextran inereased by 1.7 times after 71% PG removal, and both inulin and dextran increased by 1.6 and 2.0 times, respectively, after 93% PG removal. The diffusivities of inulin and dextran were inversely proportional to the PG content. While no change was found in the tissue's bulk fluid content. PG depletion resulted in an increase in fluid content in the upper regions of the tissue and a decrease in the lower regions. These results indicate that in intact tissue small uncharged solutes have free mobility through the inter-molecular and intra-molecular PG volumes, larger molecules have limited intra-molecular mobility, and very large molecules are excluded from the intra-molecular space.
Changing Students&#146; Perceptions: An Analysis of the Supplementary Benefits of Collaborative Software Development

Collaborative work has been in use as an instructional tool to increase student understanding through collaborative learning and to improve student performance in computer science courses. However, little work has been done to understand how the act of collaboration, through pair programming or group work, impacts a students knowledge of the benefits and difficulties of collaborative work. Experience in collaborative work is essential preparation for professional software development. A study was conducted at North Carolina State University to assess changes in advanced undergraduate students perceptions of pair programming and collaboration. Student personality types, learning styles, and other characteristics were gathered during two semesters of an undergraduate software engineering course. The study found that, after experiencing pair programming, most students indicated a stronger preference to work with another student, believed that pairing made them more organized, and believed that pairing saved time on homework assignments. Students who disliked their collaborative experiences were predominantly reflective learners, introverts, and strong coders. Those students also cited that a non-participatory partner and difficulties scheduling meeting times outside of the classroom were primary reasons for disliking pair programming. Personality type and learning style had little effect on the changes in perceptions of collaboration.
The Effects of Source Credibility and Performance Rating Discrepancy on Reactions to Multiple Raters1

Using multiple feedback sources, the present study investigated the effects of source credibility and performance rating discrepancy on recipients' reactions. Individuals performed an ambiguous group task, rated their own performance on the task, and were later provided bogus feedback ostensibly from their peers and an expert rater. Individuals reacted toward the feedback and the source of the feedback as a function of the rating discrepancy and credibility of the feedback source. Generally, more credible sources and their feedback were evaluated more favorably. However, as predicted, this effect was overcome by performance rating discrepancy in the predicted conditions. The results show the importance of studying the interactive effects of message and source characteristics on individuals' reactions.
The Power of Continuity in Graduate Teacher Education Master's Programmes.

The intentional development of continuity as it applies to programme structure, themes and outcomes is examined for their power in providing a coherent circular connection between the philosophy, operation, assessment and outcomes of a graduate teacher education programme. It is argued that the intentional development of programme continuity will address the emergence of standards as evaluative criteria and in meeting the characteristics of a constructivist learning model. The results of the specific designs of continuity provide for a meaningful learning and a true professional growth experience for the graduate student as well as a coherent programme delivery model.
MARKET MICRSOTRUCTURE CHANGES AROUND ACCELERATED SHARE REPURCHASE ANNOUNCEMENTS

I investigate the impact on trading characteristics of firms announcing share repurchases using a relatively new buyback method—accelerated share repurchases (ASRs). I find that trading costs decrease and market quality improves following an ASR announcement. The improvement in liquidity is not accompanied by significant changes in information asymmetry or price volatility. Multivariate tests show that the change in volatility and the presence of price constraints in the ASR agreement are significant in explaining the changes in spreads, but the reasons given by firms for conducting the ASRs are not. Thus, in the case of ASRs, the announced involvement of an investment bank buying shares on behalf of the firm improves liquidity without significantly affecting the level of information asymmetry.
Sensing and Responding to Hypoxia, Molecular and Physiological Mechanisms'

SYNOPSIS. In order to adapt to low oxygen it is necessary first to be able to detect hypoxia, then to initiate the appropriate defense mechanisms. There are two basic detectors: molecular sensors that are directly linked to gene regulation and metabolic indicators that are triggered when the cell goes into a state of energy imbalance. The molecular responses to oxygen deprivation are characterized in a variety of cell types and include activation of oxygen sensors, signaling through specific promoter elements and subsequent downstream adaptations. Many of the components are highly conserved across species. In the brain, the most hypoxic vulnerable of all vertebrate tissues, low oxygen quickly results in a fall in ATP and a consequent increase in adenosine. Both changes act as metabolic indicators of cellular energy crisis and effect mechanisms to reduce metabolic demand. Important lessons on the potential scope of such mechanisms can be provided by the anoxic tolerant turtle brain. Anoxia provokes an early release of adenosine which mediates channel arrest, causes a reduction in K 1 efflux and Ca 2 1 influx, and inhibits excitatory neurotransmitter release. There is a differential expression between normoxic and anoxic turtle brains of transcripts encoding the immediate early gene products c-fos and c-jun, the HSP-70 and the apoptosis regulators bcl-2 and bax. WHAT IS NORMOXIA FOR THE MITOCHONDRION? Metazoan life has evolved to take advantage of the high energy yield that can be derived from oxygenbased respiration and in all eucaryotes aerobic production of ATP by oxidative phosphorylation takes place in the mitochondria whereby each mole of glu
Normal and malignant muscle cell transplantation into immune compromised adult zebrafish.

Zebrafish have become a powerful tool for assessing development, regeneration, and cancer. More recently, allograft cell transplantation protocols have been developed that permit engraftment of normal and malignant cells into irradiated, syngeneic, and immune compromised adult zebrafish. These models when coupled with optimized cell transplantation protocols allow for the rapid assessment of stem cell function, regeneration following injury, and cancer. Here, we present a method for cell transplantation of zebrafish adult skeletal muscle and embryonal rhabdomyosarcoma (ERMS), a pediatric sarcoma that shares features with embryonic muscle, into immune compromised adult rag2E450fs homozygous mutant zebrafish. Importantly, these animals lack T cells and have reduced B cell function, facilitating engraftment of a wide range of tissues from unrelated donor animals. Our optimized protocols show that fluorescently labeled muscle cell preparations from α-actin-RFP transgenic zebrafish engraft robustly when implanted into the dorsal musculature of rag2 homozygous mutant fish. We also demonstrate engraftment of fluorescent-transgenic ERMS where fluorescence is confined to cells based on differentiation status. Specifically, ERMS were created in AB-strain myf5-GFP; mylpfa-mCherry double transgenic animals and tumors injected into the peritoneum of adult immune compromised fish. The utility of these protocols extends to engraftment of a wide range of normal and malignant donor cells that can be implanted into dorsal musculature or peritoneum of adult zebrafish.
Spatially Resolved MicroDiffraction Analysis of the Plastic Deformation in the Shock Recovered Al Single Crystaltal

A spatially resolved diffraction method with a sub micrometer-diameter beam and 3D differential aperture technique together with MD simulations, SEM and OIM analysis are applied to understand the arrangements of voids, geometrically necessary dislocations and strain gradient distribution in samples of Al (123) single crystal shocked to incipient spallation fracture. We describe how geometrically necessary dislocations and effective strain gradient alter white beam Laue patterns of the shocked materials. We show how to quantitatively determine the orientation and density of geometrically necessary dislocations in the shock recovered Al samples being initially oriented for single slip.
Expressions for the high frequency fields in the focal region of symmetrical hyperboloidal focusing lens placed in chiral medium

Abstract In this article, Geometric method (GO) and Maslov's method have been used to obtain the expressions for high frequency field refracted by a hyperboloidal focusing lens placed in homogenous and reciprocal chiral medium. High frequency focal region problems are transformed into focal free domain. The high-frequency field expressions that include the focal region obtained from GO method fail at the focal region, so Maslov's method has been used to find the field expressions which are also valid around the focal point. By using hybrid space, Maslov's method combines the simplicity of ray theory and the generality of Fourier transform method. Using the derived expressions numerical results around the focal region are plotted using MATLAB. These results show the effect of chirality parameter β on the focal region fields of hyperboloidal focusing lens placed in chiral medium.
Less peripheral fatigue after prior exercise is not evidence against the regulation of the critical peripheral fatigue threshold

to the editor: Johnson and colleagues ([2][1]) report that cycling endurance time is substantially diminished and end-exercise peripheral locomotor muscle fatigue significantly lower when preceded by fatiguing arm cranking exercise. This is certainly an interesting study, and the findings are
Geometric Representation of the Pelvic Organs

Abstract This chapter is designed to help the reader become familiar with standard methods for describing pelvic organ geometry, suitable for biomechanical computational analysis. To perform structural engineering analysis of the pelvic floor tissues, they must first be represented geometrically. This is done via a technique called segmentation, in which individual organs and/or tissue elements are outlined, and given unique labels. The interesting tissues are usually identified on standard radiologic image stacks — usually magnetic resonance imaging (MRI) or computed tomography (CT) scans. The goal of segmentation is to identify a desired tissue on the original (grayscale) image, and trace out (or label) its boundaries. For each organ or tissue of interest, the labeling is performed, either manually or semiautomatically. Because pelvic floor structures exist in a three-dimensional (3-D) space, it is necessary to represent the tissues as 3-D structures. This 3-D representation is facilitated by the method of acquiring MRI and CT image data. Both CT and MRI will produce grayscale source image data sets. Each data set consists of a “stack” of 2-D images, covering the region of the body that was scanned. The extent of the scanned region is called the field of view, and the grayscale images are sometimes referred to as the source images. This chapter will discuss the geometric representation of pelvic floor MRI grayscale data, as well as the segmentation of this data to produce labelmaps suitable for computational analysis and 3-D reconstruction of the organs and tissues of interest. Manual, semiautomatic, and automatic segmentation methods will be briefly introduced, in preparation for a more detailed discussion of automated segmentation in a later chapter. The chapter will conclude with a review of the trade-offs between the segmentation methods, and discussion of the issues with repeatability, reliability, and fidelity of these methods. The chapter focuses on MRI source data, with the understanding that the general principles will apply to CT sourced images as well.
Micromechanisms of Deformation and Fracture in Rapidly Solidified Ni3Al Alloys

Rapidly solidified Ni76 Al24 ribbons, with and without boron, have been the subject of in-situ TEM deformation studies, as well as X-ray and TEM characterization and TEM fractography. The aim has been to gain a better understanding of the influence of a reduced degree of order on grainboundary behavior and ductility. This, in turn, allows fresh insights to be gained, both into the manner in which boron additions can enhance ductility, and into the potential usefulness of sequential ordering in intermetallic alloys with a tendency to intergranular failure. Lower degrees of order are found to reduce stress concentrations at grain boundaries; this effect is due to easier generation of dislocations from boundary sources, and, to a lesser extent, the braking action of thermal APB's on dislocation motion. The beneficial effect of boron on ductility is seen to result, at least in part, from enhanced boundary cohesive strength.
ENVIRONMENTAL REVIEWS AND CASE STUDIES: Decision Making in the Environmental Impact Assessment Process

This article analyzes the decision-making processes used by government agencies when trying to decide whether to approve or reject projects that impact the environment. This article examines some o...
Electronic Structure Calculations on a Real-Space Mesh with Multigrid Acceleration

We have developed a set of techniques for performing large scale ab initio calculations using multigrid accelerations and a real-space grid as a basis. The multigrid methods permit efficient calculations on ill-conditioned systems with long length scales or high energy cutoffs. We discuss the design of pseudopotentials for real-space grids, and the computation of ionic forces. The technique has been applied to several systems, including an isolated C60 molecule, the wurtzite phase of GaN, a 64-atom cell of GaN with the Ga d-states in valence, and a 443-atom protein. The method has been implemented on both vector and parallel architectures. We also discuss ongoing work on O(N) implementations and solvated biomolecules.
Observations of Dislocation Sources in an Aluminium-Copper-Silicon Alloy

Abstract Electron microscopic evidence is presented which indicates that silicon particles in an Al-4% Cu alloy act as sources of glide dislocation loops during quenching. The Burgers vectors of the loops, identified by bright-field electron diffraction techniques, are of the type a/2 . Small prismatic loops have been observed adjacent to the screw component of the glide loops in some instances. A semi-quantitative analysis of the forces near the particles is made. A critical particle size for dislocation nucleation is predicted. Some aspects of the equilibrium diameter of the glide loop are treated. The results of the calculations are compared with the electron microscopic observations, and some speculations about dispersion strengthened materials are made.