cssi/SciSciGPT-SciSciNet huggingface dataset:
From Jebel Marra to Blue Nile: Violence in Darfur and Oromia

The underlying cause for the Gumuz militia attacks on Oromo villages in western Oromia and the loss of thousands of lives and properties was political rather than economic. Never before such organized attacks ever occurred between the two friendly communities. Since the formation of the regional states, disputes and tensions had been on the rise. In various districts, there were sporadic clashes between Gumuz and Oromo, the two friendly communities who had a history of peace for a long time. The boundary tensions, lack of cooperation, and mistrust between the two regional states had contributed to full-blown armed violence in 2007 and 2008. The chapter also addresses the countdown to the 2003 Darfur rebellion including the Arab-Fur war (1987–1989).
Disparities Based on Race, Ethnicity, and Socioeconomic Status Over the Transition to Adulthood Among Adolescents and Young Adults on the Autism Spectrum: a Systematic Review

Few studies have examined disparities in autism services and functional outcomes over the life course. Transition to adulthood is an especially important developmental period, as it sets up trajectories of adult functioning. This systematic review summarizes patterns of service use and transition outcomes according to race, ethnicity, and socioeconomic characteristics over the transition to adulthood. Forty studies were included. Low-income and racial/ethnic minority youth on the autism spectrum were less likely to participate in transition planning meetings, enroll in postsecondary education, find competitive employment after high school, live independently, participate in social activities, and receive health care transition services than their White and higher income peers on the autism spectrum. Racial/ethnic minority and low-income youth on the autism spectrum were more likely to be disconnected from educational, occupational, and social activities upon entering adulthood. Future research should explore the mechanisms underlying these disparities as a first step to addressing them.
Participation differences by age and depression 5 years after moderate-to-severe traumatic brain injury

Participation restrictions, including restrictions in employment, recreational activities, and social interactions, and depression are common after traumatic brain injury (TBI) and can profoundly a...
Antibiotic prescribing without documented indication in ambulatory care clinics: national cross sectional study

Abstract Objectives To identify the frequency with which antibiotics are prescribed in the absence of a documented indication in the ambulatory care setting, to quantify the potential effect on assessments of appropriateness of antibiotics, and to understand patient, provider, and visit level characteristics associated with antibiotic prescribing without a documented indication. Design Cross sectional study. Setting 2015 National Ambulatory Medical Care Survey. Participants 28 332 sample visits representing 990.9 million ambulatory care visits nationwide. Main outcome measures Overall antibiotic prescribing and whether each antibiotic prescription was accompanied by appropriate, inappropriate, or no documented indication as identified through ICD-9-CM (international classification of diseases, 9th revision, clinical modification) codes. Survey weighted multivariable logistic regression was used to evaluate potential risk factors for receipt of an antibiotic prescription without a documented indication. Results Antibiotics were prescribed during 13.2% (95% confidence interval 11.6% to 13.7%) of the estimated 990.8 million ambulatory care visits in 2015. According to the criteria, 57% (52% to 62%) of the 130.5 million prescriptions were for appropriate indications, 25% (21% to 29%) were inappropriate, and 18% (15% to 22%) had no documented indication. This corresponds to an estimated 24 million prescriptions without a documented indication. Being an adult male, spending more time with the provider, and seeing a non-primary care specialist were significantly positively associated with antibiotic prescribing without an indication. Sulfonamides and urinary anti-infective agents were the antibiotic classes most likely to be prescribed without documentation. Conclusions This nationally representative study of ambulatory visits identified a large number of prescriptions for antibiotics without a documented indication. Antibiotic prescribing in the absence of a documented indication may severely bias national estimates of appropriate antibiotic use in this setting. This study identified a wide range of factors associated with antibiotic prescribing without a documented indication, which may be useful in directing initiatives aimed at supporting better documentation.
Cold Nights, City Lights: Artificial Light at Night Reduces Photoperiodically Induced Diapause in Urban and Rural Populations of Aedes albopictus (Diptera: Culicidae)

As the planet becomes increasingly urbanized, it is imperative that we understand the ecological and evolutionary consequences of urbanization on species. One common attribute of urbanization that differs from rural areas is the prevalence of artificial light at night (ALAN). For many species, light is one of the most important and reliable environmental cues, largely governing the timing of daily and seasonal activity patterns. Recently, it has been shown that ALAN can alter behavioral, phenological, and physiological traits in diverse taxa. For temperate insects, diapause is an essential trait for winter survival and commences in response to declining daylight hours in the fall. Diapause is under strong selection pressure in the mosquito, Aedes albopictus (Skuse); local adaptation and rapid evolution has been observed along a latitudinal cline. It is unknown how ALAN affects this photosensitive trait or if local adaptation has occurred along an urbanization gradient. Using a common garden experiment, we experimentally demonstrated that simulated ALAN reduces diapause incidence in this species by as much as 40%. There was no difference, however, between urban and rural demes. We also calculated diapause incidence from wild demes in urban areas to determine whether wild populations exhibited lower than predicted incidence compared to estimates from total nocturnal darkness. In early fall, lower than predicted diapause incidence was recorded, but all demes reached nearly 100% diapause before terminating egg laying. It is possible that nocturnal resting behavior in vegetation limits the amount of ALAN exposure this species experiences potentially limiting local adaptation.
Genetic Variability in Cholesterol Metabolism

Cholesterol biosynthesis is a highly conserved metabolic process. However, genetic variability in cholesterol metabolism contributes to both rare congenital disorders and common chronic conditions. In the post-lanosterol cholesterol biosynthesis pathway, ten enzymes are associated with rare disorders including Greenberg skeletal dysplasia, Pelger–Huet anomaly, CHILD syndrome, Conradi–Hunermann syndrome, lathosterolosis, Smith–Lemli–Opitz syndrome, and desmosterolosis. In addition to these profound dominant and recessive congenital disorders, common genetic variability, in particular, single nucleotide polymorphisms (SNPs), in the genes encoding these enzymes is associated with common chronic diseases such as cancer, diabetes, blood pressure, hepatitis C progression, and Alzheimer’s disease. We will discuss the genetic causes of rare disorders in the post-squalene cholesterol biosynthesis pathway and the chronic disease effects of common genetic variability in this pathway.
COVID-TRACK: world and USA SARS-COV-2 testing and COVID-19 tracking

The COVID-19 pandemic has caused major health and socio-economic disruptions worldwide. Accurate investigation of emerging data is crucial to inform policy makers as they construct viral mitigation strategies. Complications such as variable testing rates and time lags in counting cases, hospitalizations and deaths make it challenging to accurately track and identify true infectious surges from available data, and requires a multi-modal approach that simultaneously considers testing, incidence, hospitalizations, and deaths. Although many websites and applications report a subset of these data, none of them provide graphical displays capable of comparing different states or countries on all these measures as well as various useful quantities derived from them. Here we introduce a freely available dynamic representation tool, COVID-TRACK, that allows the user to simultaneously assess time trends in these measures and compare various states or countries, equipping them with a tool to investigate the potential effects of the different mitigation strategies and timelines used by various jurisdictions. COVID-TRACK is a Python based web-application that provides a platform for tracking testing, incidence, hospitalizations, and deaths related to COVID-19 along with various derived quantities. Our application makes the comparison across states in the USA and countries in the world easy to explore, with useful transformation options including per capita, log scale, and/or moving averages. We illustrate its use by assessing various viral trends in the USA and Europe. The COVID-TRACK web-application is a user-friendly analytical tool to compare data and trends related to the COVID-19 pandemic across areas in the United States and worldwide. Our tracking tool provides a unique platform where trends can be monitored across geographical areas in the coming months to watch how the pandemic waxes and wanes over time at different locations around the USA and the globe.
Modifiable Comorbidities Associated with Cognitive Decline in Parkinson's Disease

Background Cognitive impairment (CI) is one of the most feared and debilitating complications of PD. No therapy has been shown to slow or prevent CI in PD. Objective To determine associations between modifiable comorbidities, including cardiovascular disease risk factors, mood disorders, and sleep characteristics, and rate of cognitive decline in Parkinson's disease (PD). Methods Data from the Parkinson's Progression Markers Initiative (PPMI) cohort was queried for baseline cardiovascular disease risk factors, mood disorders, and sleep characteristics. Linear mixed- effects models (LME) were used to examine the association between baseline factors and change in cognition, evaluated by the Montreal Cognitive Assessment (MoCA) over time. Baseline comorbidities found to affect MoCA decline were assessed for an association with focal cognitive domains using LME. Results Higher Body Mass Index (BMI) (β = -0.009, P = 0.039), State Trait Anxiety Inventory (STAI) (β = -0.005, P < 0.001), Geriatric Depression Scale (GDS) (β = -0.034, P < 0.001), Epworth Sleepiness Scale (ESS) (β = -0.017, P = 0.003), and REM Sleep Behavior Disorder Screening Questionnaire (RBDSQ) (β = -0.037, P < 0.001) were associated with faster rates of MoCA decline. Using established cut-offs for clinically significant symptoms, being overweight, or the presence of depression, excessive day time sleepiness (EDS), and possible REM sleep behavior disorder (pRBD), were all associated with faster rate of cognitive decline. Conclusion Several modifiable baseline comorbidities are associated with faster rate of CI over time in patients with PD. These associations identify potential opportunities for early intervention that could influence CI in PD.
Cross-Feeding of a Toxic Metabolite in a Synthetic Lignocellulose-Degrading Microbial Community.

The recalcitrance of complex organic polymers such as lignocellulose is one of the major obstacles to sustainable energy production from plant biomass, and the generation of toxic intermediates can negatively impact the efficiency of microbial lignocellulose degradation. Here, we describe the development of a model microbial consortium for studying lignocellulose degradation, with the specific goal of mitigating the production of the toxin formaldehyde during the breakdown of methoxylated aromatic compounds. Included are Pseudomonas putida, a lignin degrader; Cellulomonas fimi, a cellulose degrader; and sometimes Yarrowia lipolytica, an oleaginous yeast. Unique to our system is the inclusion of Methylorubrum extorquens, a methylotroph capable of using formaldehyde for growth. We developed a defined minimal “Model Lignocellulose” growth medium for reproducible coculture experiments. We demonstrated that the formaldehyde produced by P. putida growing on vanillic acid can exceed the minimum inhibitory concentration for C. fimi, and, furthermore, that the presence of M. extorquens lowers those concentrations. We also uncovered unexpected ecological dynamics, including resource competition, and interspecies differences in growth requirements and toxin sensitivities. Finally, we introduced the possibility for a mutualistic interaction between C. fimi and M. extorquens through metabolite exchange. This study lays the foundation to enable future work incorporating metabolomic analysis and modeling, genetic engineering, and laboratory evolution, on a model system that is appropriate both for fundamental eco-evolutionary studies and for the optimization of efficiency and yield in microbially-mediated biomass transformation.
Design of Arch Dams

The purpose of this paper is to present a comprehensive series of tables to facilitate the computation of forces, moments, and radial deflections in the design of arch dams. Seven basic load condit...
Teaching Future School Personnel to Train Parents to Implement Explicit Instruction Interventions

Students with disabilities are less likely to be proficient with basic academic skills compared to peers, indicating a need for more quality instructional time. Parent tutoring has been identified as a promising practice for supplementing instruction to improve child outcomes. However, educators are not sufficiently prepared to collaborate with and provide guidance to parents in how to support academic goals at home. We describe how an academic assessment and intervention clinic trains future school personnel to work with families to develop and implement explicit instruction parent tutoring interventions. A case example illustrates the process.
Twice exploration of tRNA +1 frameshifting in an elongation cycle of protein synthesis.

Inducing tRNA +1 frameshifting to read a quadruplet codon has the potential to incorporate a non-natural amino acid into the polypeptide chain. While this strategy is being considered for genome expansion in biotechnology and bioengineering endeavors, a major limitation is a lack of understanding of where the shift occurs in an elongation cycle of protein synthesis. Here, we use the high-efficiency +1-frameshifting SufB2 tRNA, containing an extra nucleotide in the anticodon loop, to address this question. Physical and kinetic measurements of the ribosome reading frame of SufB2 identify twice exploration of +1 frameshifting in one elongation cycle, with the major fraction making the shift during translocation from the aminoacyl-tRNA binding (A) site to the peptidyl-tRNA binding (P) site and the remaining fraction making the shift within the P site upon occupancy of the A site in the +1-frame. We demonstrate that the twice exploration of +1 frameshifting occurs during active protein synthesis and that each exploration is consistent with ribosomal conformational dynamics that permits changes of the reading frame. This work indicates that the ribosome itself is a determinant of changes of the reading frame and reveals a mechanistic parallel of +1 frameshifting with -1 frameshifting.
Ethanol purification with ozonation, activated carbon adsorption, and gas stripping

Abstract Fermentation of sugar to produce ethanol also produces volatile byproducts. This study was aimed at purifying corn-based ethanol for industrial and pharmaceutical use. The research was on treatment for 10 impurities removal after distillation. The ethanol headspace was sampled with solid-phase microextraction and analyzed with gas chromatography–mass spectrometry. A 40 mg/L ozone treatment resulted in >56% and >36% removal of styrene and 2-pentylfuran, respectively, without significant generation of byproducts. A 60 g/L activated carbon (AC) treatment with 270 min adsorption time resulted in 84%, >72%, and >78% removal of ethyl hexanoate, ethyl octanoate, and ethyl decanoate respectively. CO2-based stripping, at 675 LStripping gas/LSample, removed 65%, >82%, and >83% acetaldehyde, ethyl vinyl ether, and 1,1-diethoxyethane respectively. A combination of three approaches effectively removes these 8 impurities.
A formal model of a large memory that supports efficient execution

The validation and application of formal processor models benefits fundamentally from both efficient execution and automated reasoning about the models. We present a memory model written in the ACL2 logic, with both reasoning support and a runtime environment, that accomplishes these objectives. Our memory model provides a space-efficient implementation for an address space of 248 bytes, and is used in our development of an ISA model for x86 instructions. We define and prove invariants, and we use them to prove useful lemmas and to formally verify absence of run-time simulator errors. Our memory model also supports efficient execution through constant-time read and write access in an applicative setting.
Expression of the CD8αβ-Heterodimer on CD8+ T Lymphocytes in Peripheral Blood Lymphocytes of Human Immunodeficiency Virus− and Human Immunodeficiency Virus+Individuals

CD8+ T lymphocytes play a pivotal role in controlling human immunodeficiency virus (HIV)-1 replication in vivo. We have performed four-color flow cytometric analysis of CD8+peripheral blood lymphocytes (PBL) from 21 HIV-1 seronegative and 103 seropositive individuals to explore the phenotypic heterogeneity of CD8β-chain expression on CD8+ T lymphocytes and to clarify how its expression on CD8+ T lymphocytes may relate to acquired immunodeficiency syndrome (AIDS) clinical progression. We showed that the single monoclonal antibody (MoAb) 2ST8-5H7, directed against the CD8αβ-heterodimer, identifies CD8+ T lymphocytes as effectively as the conventional combination of anti-CD3 and anti-CD8α antibodies. However, we detected a significantly lower mean fluorescence (MF) of anti-CD8αβ staining on PBL from HIV-1 seropositive donors as compared with seronegative donors. In fact, CD8+ T lymphocytes from HIV-1–infected individuals with the lowest CD4 counts showed the lowest levels of CD8αβ MF. To explore further this change in CD8αβ expression, we assessed the expression of 14 different cell surface molecules on CD8αβ+ T lymphocytes of PBL from 11 HIV-1 seronegative and 22 HIV-1 seropositive individuals. The MF of anti-CD8αβ staining was significantly reduced on CD8+T lymphocyte subsets that showed immunophenotypic evidence of activation. The subset of lymphocytes expressing low levels of CD8αβ expressed higher levels of activation, adhesion, and cytotoxic-associated molecules and was predominantly CD45RO+ and CD28−. Finally, we monitored the expression of the CD8αβ-heterodimer on PBL of eight HIV-1–infected individuals over a 16-week period after the initiation of highly active antiretroviral therapy (HAART), including zidovudine (ZDV), lamivudine (3TC), and indinavir (IDV), and found a significant increase in the expression of the CD8αβ-heterodimer. These results suggest that antibodies recognizing the CD8αβ-heterodimer are useful tools to specifically identify CD8+ T lymphocytes. Moreover, the quantitative monitoring of CD8αβ expression allows the detection of discrete CD8+ T lymphocyte subsets and may be useful for assessing the immune status of individuals infected with HIV-1.
Creep of ceramics

This review analyses a wide range of experimental data on the creep of ceramic materials and reveals many similarities with the creep of metals. It is demonstrated that there are two important differences in the creep behaviour of ceramics: (1) there is an enhanced role of diffusion creep, and (2) in the power-law regime, ceramics divide into two categories with stress exponents of ∼ 5 and ∼ 3, respectively. It is concluded that the behaviour with an exponent of ∼ 5 represents fully ductile behaviour as in f cc metals, whereas the behaviour with an exponent of ∼ 3 is due to dislocation climb from Bardeen-Herring sources under conditions where there is either a lack of five independent slip systems or, if five independent slip systems are available, a lack of interpenetration of these systems.
Non-destructive characterization techniques for SOI substrates

Silicon-on-insulator (SOI) is very promising for submicron CMOS due to low parasitic capacitance, higher potential speed, and ease of isolation. The major requirements for the starting material are: 1) thin Si layers, 2) low active defect densities, 3) highly uniform layers, and 4) good crystalline and electrical quality. Since the variation in these parameters from wafer-to-wafer and run-to-run can be substantial, it is beneficial to qualify the starting wafers as much as possible before using them in circuit runs. An arsenal of characterization techniques has been developed to do this, emphasizing non-contact, non-destructive methods as much as possible. The methods discussed include: spectroscopic ellipsometry, automatic defect counting, photoluminescence scanning, and surface photovoltage response measurement. >
The “other factors”: using individual and relationship characteristics to predict sexual and emotional jealousy

The current study examined the effects of individual and situational variables on sexual versus emotional jealousy. One hundred and forty-two college students in romantic relationships rated how jealous they would be if they witnessed their partner in a situation evoking sexual or emotional jealousy with either a good friend or a stranger. They also completed measures of love, sociosexual orientation, egalitarian attitudes, and general levels of jealousy in their relationship. Both men and women reported that they would be more upset in response to the sexual scenario than the emotional scenario and when the rival was a stranger rather than a good friend. General emotional jealousy also contributed to the prediction of anticipated jealousy. Results are discussed in terms of evolutionary and cultural views of jealousy.
Mughal historians and the memory of the Islamic conquest of India

The Mughal historian ‘Abd al-Qadir Badauni wrote his work of history Muntakhab al-Tavarikh in the last decades of the sixteenth century. This work has been closely read only in its latter parts, and the resulting image of the author, as derived from the text, is one of a venomous and fundamentalist theologian who had opposed the conciliatory policies of the emperor Akbar towards his Hindu subjects. However, by analysing the first volume of this work, which deals with the pre-Mughal history of India, and comparing it with the work of the contemporary historian, Nizam al-Din Ahmad, one can detect a systematic pattern of editing by Badauni with far-reaching implications. Badauni was staunchly anti-absolutist and had displayed a kind of identification with India and its population from diverse status and persuasions that superceded dynastic and even strictly religious affiliation. To properly evaluate Badauni's contribution to Mughal intellectual and cultural history, we need to heed the older intellectual tr...
Malformations persist after metamorphosis of Xenopus laevis tadpoles exposed to Ni2+, Co2+, or Cd2+ in FETAX assays

This study was performed to determine whether malformations induced in Xenopus laevis embryos by exposures to divalent nickel, cobalt, or cadmium chlorides in FETAX assays persist after the tadpoles undergo metamorphosis to juvenile frogs. Embryos were exposed for four days to EC50 concentrations of Ni2+, Co2+, or Cd2+ under the standard conditions of FETAX assays; thereafter, the exposures were discontinued and the tadpoles were kept in aquaria through metamorphosis. Controls were treated similarly, without exposure to metals. At 13 weeks of age, surviving frogs were killed and examined for malformations. Control and metal-exposed groups of Xenopus did not differ significantly in their median ages at metamorphosis, mean body weights, or survival at 13 weeks. Overall incidences of malformations found in Ni(2+)-, Co(2+)-, or Cd(2+)-exposed frogs at 13 weeks of age were 55, 40, and 51%, respectively (P < 0.01 vs. 3% in controls). The malformations of metal-exposed frogs included retinal depigmentation, diastematomyelia, scoliosis, kyphosis, phocomelia, sacro-pelvic and hind-limb deformities, and dysplasia of the heart, kidney, ovary and gut.
Human responses to encounters with wildlife in urban parks.

Abstract A total of 3,697 subjects at seven study sites were observed directly, and 246 were interviewed on site, to determine human responses to wildlife encounters in five urban or suburban parks in Seattle, Washington, and Denver, Colorado. Fifty‐five percent of the park visitors studied made an observable, spontaneous response to the wildlife present; 74% of these persons made a perceptible orientation to the wildlife, 20% followed up with investigation, and 6% made deliberate contact with the wildlife. More than 90% said the wildlife encounters enhanced their park visit that day. These data on responses to wildlife and the conditions associated with them provide basic information about how wildlife enhances urban park visitation.
Prior Product Knowledge and Its Influence on the Traveler's Information Search Behavior

ABSTRACT The purpose of this study is to expand the concept of tourist information search by examining the concept of prior product knowledge and its influence on the traveler's information search behavior. Prior product knowledge is examined as having two components: expertise and familiarity. Familiarity is examined as having three levels: low, medium and high. Findings indicate that expert travelers and familiar travelers are likely to utilize different sources of information for trip planning. Findings also indicate that the level of familiarity is likely to influence travelers' information search behavior.
The politics of protest in hybrid regimes: managing dissent in post-communist Russia

The Politics of Protest in Hybrid Regimes: Managing Dissent in Post-Communist Russia is a research volume. There are perhaps just a few works of its kind. Most works on this topic are scholarly, in...
The Large srh Family of Chemoreceptor Genes in Caenorhabditis Nematodes Reveals Processes of Genome Evolution Involving Large Duplications and Deletions and Intron Gains and Losses

The srh family of chemoreceptors in the nematode Caenorhabditis elegans is very large, containing 214 genes and 90 pseudogenes. It is related to the str, stl, and srd families of seven-transmembrane or serpentine receptors. Like these three families, most srh genes are concentrated on chromosome V, and mapping of their chromosomal locations on a phylogenetic tree reveals 27 different movements of genes to other chromosomes. Mapping of intron gains and losses onto the phylogenetic tree reveals that the last common ancestral gene of the family had five introns, which are inferred to have been lost 70 times independently during evolution of the family. In addition, seven intron gains are revealed, three of which are fairly recent. Comparisons with 20 family members in the C. briggsae genome confirms these patterns, including two intron losses in C. briggsae since the species split. There are 14 clear C. elegans orthologs for these 20 genes, whose average amino acid divergence of 68% allows estimation of 85 gene duplications in the C. elegans lineage since the species split. The absence of six orthologs in C. elegans also indicates that gene loss occurs; consideration of all deletions and terminal truncations of srh pseudogenes reveals that large deletions are common. Together these observations provide insight into the evolutionary dynamics of this compact animal genome.
The Value of Frame-Delays in the Sequential Coding of Correlated Sources

The problem of sequential coding of correlated sources with causal encoding and noncausal decoding frame- delays is studied. The fundamental tradeoffs between individual frame rates, individual frame distortions, and decoding frame-delays are stated in terms of a single-letter information-theoretic characterization of the rate-distortion region for general inter- frame source correlations and certain types of (potentially frame- specific and coupled) single-letter fidelity criteria. For sources which are spatially stationary memoryless and temporally Gauss-Markov, mean squared error (MSE) frame distortions, and a sum-rate constraint, it is shown that causal sequential encoding with one-step delayed noncausal sequential decoding exactly matches the sum-rate-MSE performance of joint coding for all nontrivial MSE-tuples satisfying certain positive semi-definiteness conditions. Generalizations to multiple frames and arbitrary frame-delays are also presented and discussed.
Seasonal variations in dissolved organic carbon concentrations and characteristics in a shallow coastal bay

Abstract Dissolved organic matter (DOM) composition and dynamics in temperate shallow coastal bays are not well described although these bays may be important as local sources of organic carbon to ocean waters and are often sites of economically-important fisheries and aquaculture. In this study surface water samples were collected on a monthly to bi-monthly basis over two years from a mid-Atlantic coastal bay (Chincoteague Bay, Virginia and Maryland, USA). Dissolved organic carbon (DOC) concentrations and light absorbance characteristics were measured on sterile-filtered water, and high-molecular weight (> 1 kDa) dissolved OM (DOM) was isolated to determine stable isotope composition and molecular-level characteristics. Our time series encompassed both a drought year (2002) and a year of above-average rainfall (2003). During the dry year, one of our sites developed a very intense bloom of the brown tide organism Aureococcus anophagefferens while during the wet year there were brown tide bloom events at both of our sampling sites. During early spring of the wet year, there were higher concentrations of > 1 kDa DOC; this fraction represented a larger proportion of overall DOC and appeared considerably more allochthonous. Based upon colored dissolved organic matter (CDOM) and high-molecular weight DOM analyses, the development of extensive phytoplankton blooms during our sampling period significantly altered the quality of the DOM. Throughout both years Chincoteague Bay had high DOC concentrations relative to values reported for the coastal ocean. This observation, in conjunction with the observed effects of phytoplankton blooms on DOM composition, indicates that Chincoteague Bay may be a significant local source of “recently-fixed” organic carbon to shelf waters. Estimating inputs of DOC from Chincoteague Bay to the Mid-Atlantic Bight suggests that shallow productive bays should be considered in studies of organic carbon on continental shelves.
Room temperature cw and pulsed nearinfrared tunable laser operation of Cr/sup 4+/: Ca/sup 2/GeO/sup 4/

The demonstration of laser operation1 of chromium-doped forsterite (Cr:Mg2SiO4) has led to interest in other Cr4+-doped crystals suitable for laser operation in the 1.2-1.6 μm wavelength region.
Field investigation and performance of bridge approach slabs

Bridge approach slabs are designed to function as a transitional roadway to the bridge deck, spanning the distance between the abutment and the road pavement. However, the number of rough riding approaches with heavy maintenance requirements is sufficient to convince highway agencies that a serious problem exists. The complaints usually describe a ‘bump’ that motorists feel when they approach or leave bridges. This bump results in reduction of steering response, distraction to the driver, amplified truck impact and dynamic response in bridge decks, and expense to maintenance operations. Approach slabs can lose their contact supports due to various reasons, including the settlement of soil and the bulging of embankments. The objective of this paper is to present results from a study to evaluate the analytical behaviour and the field performance of new design alternatives that could reduce or eliminate this problem. The new designs were analysed using comprehensive finite element (FE) models and were also b...
Role of dipolar and exchange interactions in the positions and widths of EPR transitions for the single-molecule magnets Fe 8 and Mn 12

We examine quantitatively the temperature dependence of the linewidths and line shifts in electron paramagnetic resonance experiments on single crystals of the single-molecule magnets ${\mathrm{Fe}}_{8}$ and ${\mathrm{Mn}}_{12},$ at fixed frequency, with an applied magnetic field along the easy axis. We include intermolecular spin-spin interactions (dipolar and exchange) and distributions in both the uniaxial anisotropy parameter D and the Land\'e g factor. The temperature dependence of the linewidths and the line shifts are mainly caused by the spin-spin interactions. For both ${\mathrm{Fe}}_{8}$ and ${\mathrm{Mn}}_{12},$ the temperature dependence of the calculated line shifts and linewidths agrees well with the trends of the experimental data. The linewidths for ${\mathrm{Fe}}_{8}$ reveal a stronger temperature dependence than those for ${\mathrm{Mn}}_{12},$ because for ${\mathrm{Mn}}_{12}$ a much wider distribution in D overshadows the temperature dependence of the spin-spin interactions. For ${\mathrm{Fe}}_{8},$ the line-shift analysis suggests two competing interactions: a weak ferromagnetic exchange coupling between neighboring molecules and a longer-ranged dipolar interaction. This result could have implications for ordering in ${\mathrm{Fe}}_{8}$ at low temperatures.
CLIENTS ROLE CHOICES: UNEXPLORED FACTORS IN INTERVENTION DECISIONS

The role of the client in social work interventions has not been extensively explored in the professional literature. However, the client role varies significantly in different models of care and carries vast differences in the expectations and behaviors required of clients in the process. Clients’ individual characteristics, preferences, and expectations make them better suited to some approaches than others. This paper explores the change in perspectives on consumers emerging in the field and analyzes client role factors in four intervention models. It will also discuss the “fit” between the client and the particular approach as well as implications for outcomes and evidence-based practice.
Non-Destructive Evaluation of Carbon Fiber Composite Reinforcement Content

The use of light-weight, high-strength composite materials in motors, generators, and energy storage devices has become common as a means to maximize energy density. To ensure reliability, non-destructive and destructive evaluation techniques have been employed to measure the mechanical properties of fabricated components. In carbon fiber-reinforced, polymer matrix composites, mechanical strength is primarily derived from the fiber volume fraction. Due to the lack of a nondestructive method, common techniques for fiber volume determination are currently destructive. In this investigation, a non-destructive method for the measurement of the fiber volume fraction of carbon fiber-reinforced, polymer matrix composites has been developed using cold neutron prompt gamma activation analysis (PGAA). Fiber volume determination is accomplished in this technique by measuring and comparing the carbon and hydrogen content in a given sample (or samples). PGAA is a nuclear analytical technique performed by exposing a sa...
Orientation specificity in spatial memory: what makes a path different from a map of the path?

Three studies investigated the factors that lead spatial information to be stored in an orientation-specific versus orientation-free manner. In Experiment 1, we replicated the findings of Presson and Hazelrigg (1984) that learning paths from a small map versus learning the paths directly from viewing a world leads to different functional characteristics of spatial memory. Whether the route display was presented as the path itself or as a large map of the path did not affect how the information was stored. In Experiment 2, we examined the effects of size of stimulus display, size of world, and scale transformations on how spatial information in maps is stored and available for use in later judgments. In Experiment 3, we examined the effect of size on the orientation specificity of the spatial coding of paths that are viewed directly. The major determinant of whether spatial information was stored and used in an orientation-specific or an orientation-free manner was the size of the display. Small displays were coded in an orientation-specific way, whereas very large displays were coded in a more orientation-free manner. These data support the view that there are distinct spatial representations, one more perceptual and episodic and one more integrated and model-like, that have developed to meet different demands faced by mobile organisms. Language: en
Melting thermodynamics of reversible DNA/ligand complexes at interfaces.

A variety of solution methods exist for analysis of interactions between small molecule ligands and nucleic acids; however, accomplishing this task economically at the scale of hundreds to thousands of sequences remains challenging. Surface assays offer a prospective solution through array-based multiplexing, capable of mapping out the full sequence context of a DNA/ligand interaction in a single experiment. However, relative to solution assays, accurate quantification of DNA/ligand interactions in a surface format must contend with limited understanding of molecular activities and interactions at a solid–liquid interface. We report a surface adaptation of a solution method in which shifts in duplex stability, induced by ligand binding and quantified from melting transitions, are used for thermodynamic analysis of DNA/ligand interactions. The results are benchmarked against solution calorimetric data. Equilibrium operation is confirmed through superposition of denaturation/hybridization transitions trigge...
The Effect of Effort Grading on Learning.

Abstract In the fall of 2004, Benedict College – a Historically Black College in Columbia, SC – began enforcing a new grading policy called Success Equals Effort (SE 2 ). Under this policy, students taking freshman and sophomore level courses were assigned grades that explicitly rewarded not only content learning (“knowledge” grade) but also measures of effort (“effort” grade). This paper examines the effects of effort grading using two stage least squares and fixed effect estimates. I find evidence of a strong positive correlation between “effort” grades and “knowledge” grades. Under some restrictions this relationship can be interpreted as “effort” producing “knowledge”.
Escherichia coli QueD Is a 6-Carboxy-5,6,7,8-tetrahydropterin Synthase†

To elucidate the early steps required during biosynthesis of a broad class of 7-deazapurine-containing natural products, we have studied the reaction catalyzed by Escherichia coli QueD, a 6-pyruvoyl-5,6,7,8-tetrahydropterin synthase (PTPS) homologue possibly involved in queuosine biosynthesis. While mammalian PTPS homologues convert 7,8-dihydroneopterin triphosphate (H2NTP) to 6-pyruvoyltetrahydropterin (PPH4) in biopterin biosynthesis, E. coli QueD catalyzes the conversion of H2NTP to 6-carboxy-5,6,7,8-tetrahydropterin (CPH4). E. coli QueD can also convert PPH4 and sepiapterin to CPH4, allowing a mechanism to be proposed.
Molecular organization of the bacteriophage P22 coat protein shell

Abstract P22 is a moderately large double-stranded DNA-containing bacteriophage. The mature virion contains several minor protein species and a single major coat protein species. Freeze-etch electron microscopic evidence is presented here to show that the coat protein is present on the exterior of the virion in a T = 7 levo type lattice with icosahedral symmetry. Each of the coat protein subunits participates in the formation of two morphological units visible in the electron microscope, one at a local 3-fold axis of symmetry, and one at a 5-fold or local 6-fold axis of symmetry, thus giving the appearance of a T = 21 dextro surface lattice. The fact that the precursor particles (proheads) have previously been shown to have a surface structure similar to phage (Earnshaw et al. , 1976) suggests a model for the coat protein shell expansion during DNA encapsidation.
USE OF CHEMICAL SENSOR ARRAYS FOR FOOD AND FRAGRANCE ANALYSIS

. Many workers have recently developed and demonstrated the use of gas sensor arrays to detect and recognize a variety of compounds. In general, a pattern recognition approach is used in which the signature of an unknown sample is compared to a library of signatures of known substances. All of these efforts have shown varying degrees of success when applied to pure compounds. Unfortunately, flavors and fragrances are never pure compounds. A prototype gas sensor array has been constructed and tested with various mixtures of interest. The results are discussed in terms of their implication to the food and fragrance industry. Early experiments on gasoline-alcohol mixtures demonstrated that the signatures do not follow a rule of mixing, but were more strongly influenced by the more volatile and/or more reactive component. This led us to examine the behavior of alcohol-water mixtures for possible quality control in the distilling industry. We discovered that the signature of alcohol dominated even at concentrations as low as ten percent. Preliminary experiments were also performed to see if the prototype sensor array could be used to automatically detect rancidity in dairy products. Flavorings and essential oils are in many cases even more complex mixtures. The behavior of representative classes of these substances were characterized in an attempt to understand their signatures on the basis of their constituents.
Large aperture “photon bucket” optical receiver performance in high background environments

The potential development of large aperture ground-based “photon bucket” optical receivers for deep space communications is receiving considerable attention1. However, high quality optical apertures in the 10–30 meter range are costly and difficult to build with accurate surfaces to ensure narrow fields-of-view (FOV). One approach currently under consideration is to polish the aluminum reflector panels of large 34-meter microwave antennas to high reflectance, and accept the relatively large FOV generated by state-of-the-art polished aluminum panels with surface accuracies on the order of a few microns, corresponding to several-hundred micro-radians FOV. Sunlight scattered by the atmosphere becomes significant at micron wavelengths when pointing to within a few degrees of the sun, even with narrow bandwidth optical filters2. Assuming pulse-position modulation (PPM) and Poisson-distributed photon-counting detection, a “polished panel” photon-bucket receiver with large FOV will collect hundreds of background photons per PPM slot, along with comparable signal photons due to its large aperture. Here we demonstrate that communications performance in high-background high-signal environments depends more strongly on signal photons than on background photons, implying that large increases in background energy can be compensated by a relatively small increase in signal energy, which in turn can be accomplished by a modest increase in receiver aperture.
Origins and Virulence Mechanisms of Uropathogenic Escherichia coli

Strains of uropathogenic E. coli (UPEC) are the primary cause of urinary tract infections, including both cystitis and pyelonephritis. These bacteria have evolved a multitude of virulence factors and strategies that facilitate bacterial growth and persistence within the adverse settings of the host urinary tract. Expression of adhesive organelles like type 1 and P pili allow UPEC to bind and invade host cells and tissues within the urinary tract while expression of iron-chelating factors (siderophores) enable UPEC to pilfer host iron stores. Deployment of an array of toxins, including hemolysin and cytotoxic necrotizing factor 1, provide UPEC with the means to inflict extensive tissue damage, facilitating bacterial dissemination as well as releasing host nutrients and disabling immune effector cells. These toxins also have the capacity to modulate, in more subtle ways, host signaling pathways affecting myriad processes, including inflammatory responses, host cell survival, and cytoskeletal dynamics. Here, we discuss the mechanisms by which these and other virulence factors promote UPEC survival and growth within the urinary tract. Comparisons are also made between UPEC and other strains of extraintestinal pathogenic E. coli that, although closely related to UPEC, are distinct in their abilities to colonize the host and cause disease.
Louann salt geochemistry (Gulf of Mexico sedimentary basin, U.S.A.): A preliminary synthesis

Abstract Samples of Jurassic salt and anhydrite were obtained from throughout the Gulf of Mexico sedimentary basin. Salt samples have been analyzed for bromide content and 87 Sr 86 Sr of anhydrite inclusions, and anhydrite for 87 Sr 86 Sr . Most samples of diapiric salt contain 87 Sr 86 Sr ratios are commonly radiogenic relative to the ratio in presumed coeval Jurassic (Callovian) seawater. Both these observations suggest that during deformation, salt undergoes extensive rock-water interaction, losing bromide to the reacting brines, and incorporating radiogenic Sr. Similar behavior of anhydrite during deformation with respect to Sr is also observed. Samples of deeply buried salt exhibit bromide concentrations consistent with the precipitation of marine halite, but include several samples with extremely high values. Few 87 Sr 86 Sr ratios, however, seem to be characteristic of coeval Callovian seawater. Samples with normal bromide content but radiogenic Sr suggest primary deposition from, or recrystallization in the presence of radiogenic fluids with marine-like bromide content. Samples with extremely high bromide content and radiogenic Sr values suggest recrystallization in fluids with elevated bromide content due to loss of bittern phases or extensive rock-water interaction of bedded salt during deep burial. The data suggest a dynamic system in which physical modification of evaporites during deformation and deep burial is accompanied by chemical modification.