cssi/SciSciGPT-SciSciNet huggingface dataset:
Visco-plastic response of deep tunnels based on a fractional damage creep constitutive model

Hard rock tunnels under high geo-stresses, and weak, soft rock tunnels show evident continued deformation after excavation, which is closely associated with the time-dependent behavior of rocks. In this paper, a novel fractional damage visco-plastic model was put forward to describe the creep response of rocks with the following elements: (1) an Abel dashpot, (2) a damaged Abel dashpot coupled with damage formulation that is based on a statistical distribution of microfractures, (3) elastic spring, and (4) Hoek–Brown plastic element. Firstly, the creep equation of the visco-plastic model was derived and validated against experimental data. Secondly, a closed-form analytical solution for the creep deformation of the surrounding rock around deep, circular tunnels was obtained by adopting the proposed model. Then, parametric studies were conducted to reveal the influence of the time-dependent parameters on the deformation of surrounding rocks. Finally, laboratory tests were conducted to provide data to validate the model. The auxiliary tunnel of the Jinping II hydropower station was chosen to demonstrate the analytical solution’s applicability to real-world problems. The results showed that: (1) the proposed constitutive model can adequately reflect the primary, secondary and tertiary creep stages of rocks; (2) the tunnel deformation increases as the Geological Strength Index (GSI) value in the Hoek–Brown model decreases, and for each time-dependent parameter, its influence on the tunnel deformation is more evident in weak rock mass than that in rock mass with higher GSI; (3) all features regarding the relationship between the tunnel deformation and the parameters of surrounding rocks agree well with physical meanings of each parameter; and (4) the deformation curves of the analytical solution and laboratory and field tests are consistent with each other with respect to curve shape and the magnitude, indicating that the proposed analytical solution can be reliably used to predict and study the creep deformation of tunnels.
Introduction to Corporate Governance

This note provides an introduction to corporate governance from a managerial perspective, covering key aspects of board responsibilities and board composition, the regulatory environment and legal duties of directors, and changes in governance systems over time, with a focus on publicly traded firms in the United States. Excerpt UVA-S-0356 Rev. Jul. 27, 2021 Introduction to Corporate Governance Boards of directors represent the highest echelons of the business world and oversee the overall direction of firms and their strategies. Boards are often lauded for being essential advisers to corporate America's most successful and admired companies, but on the other side of the coin, following almost every major business scandal, blame is placed on the board and questions arise about lapses in governance. What is the role of boards of directors and corporate governance systems? And, more importantly, what constitutes good governance? This note will provide an introduction to corporate governance from a managerial perspective, covering key aspects of board responsibilities and board composition, the regulatory environment and legal duties of directors, and changes in governance systems over time, with a focus on publicly traded firms in the United States. This note will provide only a general overview of the legal aspects of corporate governance and the legal duties of directors. What Is Corporate Governance? . . .
Stock Return Dynamics Under Earnings Management

This paper explores how earnings management influences asset returns and return volatility via real economic activity. In the model, firms smooth earnings via the costly and economically suboptimal intertemporal transfer of assets and liabilities. As a result, the firm's stock return follows a process that conforms to an EGARCH-like statistical model. The key idea is that real earnings management generates an unobservable cost, and the market has to infer the underlying wealth of the firm from the smoothed reported earnings series. This framework may help explain why asset returns underreact to good news and overreact to bad news, while no news is always good news to the market. Empirical evidence that earnings innovations impact future return volatility, in line with the model's predictions, is found in the data.
X-Ray Emission Following Ion Beam and Plasma Excitations

The hallmark of much recent work in x-ray spectroscopy is the study of emission from high ionization states. Such states can be produced by heavy-ion impact or in very hot plasmas. Ion excitation is a flexible way to produce spectra similar to and intermediate between those resulting from electron beam and plasma excitation. Ion excited x-ray spectra are useful in atomic and collision physics research. High temperature plasmas occurring in fusion power devices emit intense x radiation which provides a useful diagnostic of conditions within such plasmas. X-ray spectra from ion impact and hot plasmas are compared in this paper. They are shown to be complementary in some cases and very similar in others.
Focusing Problem Solving in Design-Centered Learning Environments

Design-centered learning environments offer great promise for providing effective, grounded learning experiences. Learners are given a set of design criteria and a library of components which they use to design artifacts that will satisfy the specified criteria. Despite their appeal, design-centered learning environments are plagued with complexities that can overwhelm learners. To address this problem, we have developed a proactive problem-solving focus mechanism that helps learners cope with the complexities inherent in design-centered learning. By exploiting a rich model of the design context, the focus mechanism selects design problems and intervenes with multimedia advice. The mechanism has been implemented in Design-A-Plant, a design-centered learning environment for botanical anatomy and physiology. Formative evaluations with middle school students are encouraging.
The development of surfactant synthesis in fetal rabbit lung organ culture exhibits a sex dimorphism

Abstract Sex differences in amniotic fluid and lung lavage surfacant have been found. Although these studies suggest that augmented fetal surfactant synthesis occurs earlier in the female fetus, there is little direct evidence for a sex difference in fetal surfactant synthesis. We studied the synthesis of surfactant by evaluating the appearance of labelled phospholipids in lamellar bodies recovered from sex-specific organ culture of fetal rabbit lungs. Furthermore, we studied the ability of dexamethasone to stimulate surfactant synthesis in male and female fetal lungs. Organ culture was begun on day 21 gestation. After 5 days the incorporation of [1,3-14C]glycerol into phosphatidylcholine (PC), disaturated phosphatidylcholine, phosphatidylinositol (PI), and phosphatidylglycerol was studied. Female lungs in organ culture synthesized more disaturated PC per milligram protein than male lungs. In the presence of dexamethasone (10−8 M) and dihydrotestosterone (10−8 M) an increased synthesis was noted in the female cultures of PC (270%), disaturated PC (234%), PI (281%), and phosphatidylglycerol (754%). No significant increase in the synthesis of PC or disaturated PC was observed in the male cultures. However in the male cultures smaller increases in the synthesis of PI (193%) and of phosphatidylglycerol (360%) were observed. Overall, dexamethasone stimulated synthesis in females but not in males such that significant differences in the synthesis of all phospholipids were found in the presence of 10−8 M dexamethasone. These studies show that the synthesis of surfactant in the fetal lung is sexually dimorphic, as is the ability of dexamethasone to regulate synthesis. An understanding of the mechanism which causes these differences may provide important insight into the control of the developmental clock which regulates the orderly progression of development.
Neonatal myocardium resists reperfusion injury

The response of neonatal myocardium to ischemia and reperfusion was observed in an isolated working heart model using neonatal rabbits and compared to that of the adult rabbit heart. Lipid peroxidation occurring during ischemia and that occurring during reperfusion were evaluated separately. Malondialdehyde (MDA) in heart tissue was measured as an index of lipid peroxidation, and the occurrence of oxygen free radical damage was assessed by the effects of the scavengers, superoxide dismutase and catalase, on MDA production. Baseline MDA levels were similar in neonatal and adult hearts, were changed little by treatment with normoxic cardioplegia, and were elevated in both groups by treatment with hyperoxic cardioplegia. Thus, the degree of lipid peroxidation during ischemia is similar in neonatal and adult hearts. After 10 min of retrograde reperfusion subsequent to treatment with anoxic cardioplegia, the MDA content of adult hearts was significantly greater than that of similarly treated neonatal hearts. Addition of free radical scavengers to the reperfusion medium lowered the MDA content of adult hearts significantly, but not to the level of neonatal hearts. After 60 min of reperfusion subsequent to hyperoxic cardioplegia, adult hearts had higher MDA than neonates; addition of scavengers to the cardioplegia did not lower the MDA significantly in either group. Only 5 of 12 adult hearts recovered function after hyperoxic cardioplegia, while all 12 neonatal hearts recovered. Our results indicate that neonatal myocardium suffers less damage from oxygen-centered free radicals during reperfusion than does adult myocardium.
A rapid isotope dilution method for analysis of indole-3-acetic acid and indoleacetyl aspartic acid from small amounts of plant tissue.

A method is described for analysis of indole-3-acetic acid and indoleacetyl aspartic acid in plant tissue. Methanolic extracts are purified on two small columns prior to HPLC using an electrochemical detector. In,vivo amounts are calculated by isotope-dilution analysis. The method requires only 1 g of tissue, results in relative high recoveries, and is sensitive to the 20 pmol range or below. Typical results using light-grown Pisum,sativum cv. Little Marvel tissue are given. This report is the first determination of the natural level of the aspartate derivative in growing plant tissues.
Web Development Simplified

In the late 1980s and early 1990s, an Alabama library school professor by the name of S. Michael Malinconico wrote several papers discussing the technological future of academic libraries. He predi...
Analysis of Beam-Beam Interactions with a Large Crossing Angle

The beam-beam interaction for a flat beam with a large horizontal crossing angle is studied for the case in which the vertical betatron function at the interaction point is comparable to the bunch length. It is shown that crossing with a large angle has less serious detrimental effects than is usually believed. A large crossing angle might have several merits for future high-luminosity colliding rings.
Replacing square roots by Pythagorean sums

An algorithm is presented for computing a "Pythagorean sum" a ⊕ b = √a2 + b2 directly from a and b without computing their squares or takinga square root. No destructive floating point overflows or underflows are possible. The algorithm can be extended to computet he Euclidean norm of a vector. The resulting subroutine is short, portable, robust, and accurate, but not as efficient as some other possibilities. The algorithm is particularly attractive for computers where space and reliability are more important than speed.
An improved method for the determination of trace levels of arsenic and antimony in geological materials by automated hydride generation—atomic absorption spectroscopy

Abstract An improved, automated method for the determination of arsenic and antimony in geological materials is described. After digestion of the material in sulfuric, nitric, hydrofluoric and perchloric acids, a hydrochloric acid solution of the sample is automatically mixed with reducing agents, acidified with additional hydrochloric acid, and treated with a sodium tetrahydroborate solution to form arsine and stibine. The hydrides are decomposed in a heated quartz tube in the optical path of an atomic absorption spectrometer. The absorbance peak height for arsenic or antimony is measured. Interferences that exist are minimized to the point where most geological materials including coals, soils, coal ashes, rocks and sediments can be analyzed directly without use of standard additions. The relative standard deviation of the digestion and the instrumental procedure is less than 2% at the 50 μg l -1 As or Sb level. The reagent-blank detection limit is 0.2 μg l -1 As or Sb.
XML and style sheets promise to make the web more accesible

The theme of the Sixth World Wide Web Conference, held in Santa Clara, April 6-11, was accessibility. Today's Hypertext Markup Language documents, with all the graphical bells and whistles added by Netscape and Microsoft, are biased toward a rich graphical user interface provided by the two most popular Web browsers running on desktop machines.
Temperature field in a moving semi-infinite region with a prescribed wall heat flux

Abstract Steady state conduction of heat from a stationary wall to a medium moving at a uniform velocity is the subject herein. This medium can be a solid or a fluid moving at a constant velocity. The surface of this medium is insulated until a change in the surface heat flux occurs. The determination of temperature field is the main objective herein. The results show that the surface temperature begins to increase before its arrival to the heater’s location where there is an abrupt change in the surface heat flux. The application of this phenomenon to a moving wall with frictional heating at its surface and to classical heat transfer in ducts can lead to new information.
Universal scaling relations in compressibility of solids

A particularly simple two-parameter scaling relation for the variation of the bulk modulus of solids with changing density has been found. The relation, although empirical, fits all metals and metal alloys tested, and also fits semiconductors, ionic crystals, and, with a lesser degree of success, organic compounds. The two parameters seem to be related to the rupture strength and the electronegativity of the solid.
Estrogen and progesterone activate spinal kappa-opiate receptor analgesic mechanisms

Rats and humans manifest elevated response thresholds to aversive stimuli during gestation and parturition. This pregnancy-associated antinociception is mediated, in part, by a spinal cord dynorphin/kappa antinociceptive system. Simulating the maternal pregnancy blood concentration profile (in non-pregnant animals) of 17-beta-estradiol (E2) and progesterone (P) produces an opioid antinociception which closely approximates that of actual pregnancy. The current study was initiated in order to determine whether sex steroid-induced antinociception involves a spinal cord kappa-opiate receptor-coupled system (as does the antinociception of actual gestation). Additionally, sex steroid modulation of the intrathecal (i.t.) antinociceptive effectiveness of a kappa agonist was investigated. The opioid antinociception associated with simulating the pregnancy blood concentration profile of E2 and P (hormone-stimulated pregnancy, HSP) is significantly antagonized by i.t. administration of nor-binaltorphimine, an antagonist highly specific for the kappa-opiate receptor. This indicates that exposure (of non-pregnant animals) to the pregnancy blood profile of E2 and P activates a spinal cord kappa-opiate receptor analgesic system, as occurs during actual gestation. Furthermore, during HSP, antinociceptive responsiveness to i.t. U50,488H (kappa-selective) is significantly enhanced (approximately 40%). This effect is abolished in animals treated concomitantly with steroid hormones and systemic naltrexone or i.t. nor-binaltorphimine. In contrast to the effects of steroid treatment on antinociceptive responsiveness to i.t. U50,488H, no alteration in antinociceptive responsiveness to i.t. sufentanil was observed on day 19 of HSP over all doses tested (0.1-1 nmol). Thus, during HSP (and actual gestation), a less robust constituent of intrinsic opioid pain-attenuating systems in the spinal cord is recruited. pF to mediate, at least in part, the maternal antinociception of gestation. pF, positive modulation of the spinal cord kappa analgesic system occurs post-synaptically. This laboratory previously reported that simulating the pregnancy blood concentration profile of E2 and P also positively modulates spinal dynorphin content and the processing of its precursor, suggesting a presynaptic loci of action. Thus, female rats possess a spinal dynorphin/kappa analgesic system that can be positively modulated, pre-synaptically as well as post-synaptically, by circulating sex steroids.
Hierarchical wavelet-based image model for pattern analysis and synthesis

Despite their success in other areas of statistical signal processing, current wavelet-based image models are inadequate for modeling patterns in images, due to the presence of unknown transformations inherent in most pattern observations. In this paper we introduce a hierarchical wavelet-based framework for modeling patterns in digital images. This framework takes advantage of the efficient image representations afforded by wavelets, while accounting for unknown pattern transformations. Given a trained model, we can use this framework to synthesize pattern observations. If the model parameters are unknown, we can infer them from labeled training data using TEMPLAR, a novel template learning algorithm with linear complexity. TEMPLAR employs minimum description length complexity regularization to learn a template with a sparse representation in the wavelet domain. We illustrate template learning with examples, and discuss how TEMPLAR applies to pattern classification and denoising from multiple, unaligned observations.© (2000) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
281 Leflunomide: A Novel Therapeutic Agent for Ganciclovir-Resistant Cytomegalovirus in Kidney Transplant Recipients

LEFLUNOMIDE: A NOVEL THERAPEUTIC AGENT FOR GANCICLOVIRRESISTANT CYTOMEGALOVIRUS IN KIDNEY TRANSPLANT RECIPIENTS Eram Shahira, Beje Thomas, Manish Talwar, Maria Salazar, Takamitsu Saigusa, Sarat Kuppachi, M. Francesca Egidi Medical University Of South Carolina, Charleston, South Carolina. Cytomegalovirus (CMV) is the most common viral infec on in solid organ transplant; 20%-60% of transplanted pa ents develop symptoma c CMV infec on despite specific prophylaxis. First line treatment for CMV reac va on and disease presently includes ganciclovir or valganciclovir. Cidofovir and foscarnet because of their nephrotoxicity should be considered in case of failure of the tradi onal treatment. Leflunomide is a drug approved for the treatment of rheumatoid arthri s that has been shown to have an CMV ac vity without nephrotoxicity. We report our experience with four pa ents who developed CMV reac va on and subsequent disease and failed treatment with ganciclovir and immunosuppression (IS) reduc on. Leflunomide (LF) was ini ated at the dose of 40 mg PO/daily. All of the pa ents received cadaveric renal transplants, had T-cell deple ng agent induc on (Thymoglobulin) and maintenance IS consis ng in prednisone, cellcept and tacrolimus. The viremia was monitored and detected with rou ne CMV/PCR screening. The pa ents’ characteris cs and results are shown in the table. Age at the Transplant Race/Gender CMV status (IgG) D/R Diagnosis from transplant (Months) Time to response to Leflunomide (Weeks) Pt.LB 49 C/F +/6 4 Pt.CB 38 AA/M +/2 4 Pt.CH 41 C/M +/6 5 Pt .SA 51 C/M +/+ 24 3 In conclusion our preliminary results show that LF offers an alterna ve to tradi onal an -CMV therapies for the transplant recipient with an viral resistance.
Some observations on the ultrastructure of the oocyte of Thyone briareus with special reference to the relationship of the Golgi complex and endoplasmic reticulum in the formation of yolk.

Electron microscope studies on developing oocytes of Thyone briareus reveal the proteinaceous yolk granules to first appear within components of the Golgi complex. The special association between the Golgi complexes and endoplasmic reticulum observed and described during vitellogenesi suggests an interrelationship of these two membrane systems in yolk formation. Changes in the disposition and organization of the endoplasmic reticulum as well as the transfer of nucleoli from the nucleus to the cytoplasm are also described.
SEEDLING DENSITY DEPENDENCE PROMOTES COEXISTENCE OF BORNEAN RAIN FOREST TREES

Density-dependent processes may occur at various spatial scales and may be generated by, and influence, various life stages in a population. When evaluating evidence for density dependence relevant to species coexistence, the nature of forest communities leads logically to a focus on particular scales and life stages. We assessed evidence for the dependence of seedling survival on the abundance of conspecific trees and seedlings over both wide (150-ha) and local (0.16-ha and 1-m 2 ) scales, in a species-rich Bornean rain forest. At the 150-ha scale, we identified a community-level compensatory trend in seedling survival (i.e., more abundant species had higher seedling mortality). There were parallel trends at the population level and on a local scale; seedling survival was inversely related to conspecific seedling density (in 1-m 2 quadrats) and tree basal area (in the surrounding 0.16 ha), for five out of 15 abundant species and for all species combined. As expected, seedlings of species with the highest adult abundance in 150 ha experienced the highest local densities of both conspecific seedlings and trees. Local density dependence in single- species analyses confirmed a dynamic interpretation of the community compensatory trend, i.e., that wide-scale seedling survival tends to decrease as a species' adult abundance increases. Taken together, our findings constitute strong evidence that density-dependent processes contribute to coexistence in this diverse rain forest community.
ABNORMAL MAMMOGRAM AS THE PRESENTING SIGN OF RENAL CELL CARCINOMA

About a third of all newly diagnosed cases of renal cell carcinoma have metastatic disease at presentation. 1 The most common sites are lung, bone, liver, adrenal glands and brain. We report a case of an incidentally discovered solitary focus of metastatic renal cell carcinoma following an abnormal mammogram. CASE REPORT A 77-year-old white woman without significant medical history had a 2.5 3 1.5 3 1.0 cm. right breast lesion on routine screening mammography (fig. 1, A). A mammogram 2 years earlier had been normal. There was no palpable mass and the patient was completely asymptomatic. She underwent an excisional biopsy of the breast lesion. Pathological examination was consistent with clear cell renal cell carcinoma (fig. 1, B). Computerized tomography of the abdomen revealed an 8 cm. right renal tumor with perihilar adenopathy and compression of the inferior vena cava (fig. 2). On physical examination this mass was nonpalpable. Abdominal magnetic resonance imaging confirmed the perirenal adenopathy as well as inferior vena caval compression but failed to show any evidence of tumor thrombus extending into the vena cava. Urinalysis revealed only 3 to 6 red blood cells per high power field. Right radical nephrectomy was performed. Pathological diagnosis was Fuhrman nuclear grade III/IV clear cell renal cell carcinoma, which was similar to that of the breast lesion. Tumor extended through the renal capsule into perinephric fat, and 2 lymph nodes were positive for metastatic renal cell carcinoma. Convalescence was uneventful, and the patient returned to baseline activity level. DISCUSSION
High Power and High External Efficiency m-Plane InGaN LEDs

In this paper, we report on the growth and fabrication of high power and high efficiency nonpolar m-plane (11 macr00) nitride light emitting diodes (LEDs) on low defect density bulk m-plane GaN substrates. The LEDs were grown by MOCVD on free-standing bulk m -plane GaN. All MOCVD growth was performed at atmospheric pressure, at typical V/III ratios (>3000), and at typical temperature ranges (875 to 1185degC). Standard processing was used to fabricate the LEDs. After device fabrication, the LEDs were diced and packaged using standard die and wire bonding techniques and then molded with epoxy.
A patient mobility framework that travels: European and United States-Mexican comparisons

Abstract Objectives To develop a framework that parsimoniously explains divergent patient mobility in the United States and Europe. Method Review of studies of patient mobility; data from the 2007 Flash Eurobarometer and the 2001 California Health Interview Survey was analyzed; and we reviewed government policies and documents in the United States and Europe. Results Four types of patient mobility are defined: primary, complementary, duplicative, and institutionalized. Primary exit occurs when people without comprehensive insurance travel because they cannot afford to pay for health insurance or directly finance care, as in the United States and Mexico. Second, people will exit to buy complementary services not covered, or partially covered by domestic health insurance, in both the United States and Europe. Third, in Europe, patient mobility for duplicative services provides faster or better quality treatment. Finally, governments and insurers can encourage institutionalized exit through expanded delivery options and financing. Institutionalized exit is developing in Europe, but uncoordinated and geographically limited in the United States. Conclusions This parsimonious framework explains patient mobility by considering domestic health system characteristics relating to cost and quality.
Trans content in atactic polystyrene estimated by double-quantum solid-state NMR.

Abstract The conformational statistics of atactic polystyrene have been investigated by solid-state NMR, on a sample labeled with 25% 13 CH 2 groups. Double-quantum pulse sequences are used to select statistically formed 13 C – 13 C spin pairs. An experiment correlating the 13 C – 13 C internuclear vector with the 13 C chemical-shift anisotropy determines the conformational statistics of a single backbone torsion angle. Double-quantum experiments correlating the 13 CH 2 chemical-shift anisotropies of two adjacent segments provide information on two consecutive torsion angles. The analysis of the spectra yields a trans content of 68% (±10%). This represents the first direct experimental estimate of the trans/gauche ratio in atactic polystyrene. The trans content found here agrees well with rotational-isomeric-state models but is inconsistent with results from more elaborate atomistic models that take packing effects into account.
Time Series Analysis of 20 Years of Hourly Precipitation in Southwest Michigan

Abstract Hourly precipitation data from Oshtemo Township, Michigan, located approximately 55 km east of the lee shore of Lake Michigan, for the period of April 1980 through March 2000 were examined. Diurnal analysis of precipitation as well as time series analysis of precipitation were performed on the study period. An overall nocturnal maximum in the mean accumulation of precipitation was detected during the 2-hour periods before 2000 LST and 2200 LST. Elevated spring and fall accumulations were responsible for this evening maximum. Elevated summer and winter accumulations were responsible for a weak secondary morning maximum. An overall morning maximum in the mean precipitation hours was detected during the 2-hour period before 1000 LST. ARIMA modeling verified that both precipitation accumulations and counts, for all times of the day, were significant at the 5% level. A storm event model was developed from the time series, the resulting values of which can be used as input in mesoscale climate, hydrological, and agricultural computer models: the mean pulse duration was 2.44 hours; the mean interlude between pulses was 37.64 hours; the mean event accumulation was 4.1 mm; and the mean rate was 1.8 mm / hr. Finally, inter-annual analysis performed for the period of 1981 to 1999 showed that there was no statistically significant change in precipitation over the period.
TEM study of crystalline structures of Cr–N thin films

Cr-N films were grown on Si (001) substrates by reactive magnetron sputtering under an N 2 /Ar atmosphere at room temperature. The composition of the films, expressed as Cr 1-x N x , can be varied by changing the N 2 /Ar pressure ratio during the synthesis process. Crystalline states of Cr-N films have been studied using electron diffraction. It is well known that two intermediate phases, Cr 2 N (hexagonal) and CrN (cubic), exist in the Cr-N system, and small variations around the ideal stoichiometry are tolerated. The present study shows that cubic CrN with vacancies rather than hexagonal Cr 2 N may exist in a Cr-N film with a thickness of about 50 nm produced under a low N 2 partial pressure.
Overcoming intra-cavity nonlinear phase limitations in cavity-enhanced optical parametric chirped pulse amplification through cavity-locking

In cavity-enhanced OPCPA, nonlinear phase shifts imparted on the intracavity pump pulse limit pump power loading and degrade system performance. We show that cavity-locking offsets these effects, maintaining dramatic bandwidth extension and high conversion efficiency.
Mating system and reproductive skew in a communally breeding cuckoo: hard-working males do not sire more young

In communally breeding animal societies, theory predicts that a male's investment in parental care should be correlated with his share of paternity in the mixed brood. Here I test this hypothesis in the greater ani, Crotophaga major, a Neotropical cuckoo that nests in groups composed of two to three unrelated, behaviourally monogamous pairs. Each group constructs a single nest in which all of the females lay eggs, and all group members participate in rearing the joint clutch. Previous work has shown that parental investment among males is unequal: just one male in the group performs all nocturnal incubation, and the same male also plays a greater role in diurnal incubation and nest defence. I used parentage and sibling analysis of 357 greater ani nestlings in 53 clutches to investigate genetic mating patterns and the distribution of reproduction within communal groups. Contrary to predictions, male reproductive skew was negligible and nocturnally incubating males did not sire significantly more nestlings than did non-nocturnal incubators. Approximately 75–80% of nestlings were produced by socially monogamous pairs, 12–18% by extrapair fertilizations within the same breeding group, and 3–5% by extrapair fertilizations outside the breeding group. There was no difference in the frequency of extrapair paternity between nocturnally incubating and non-nocturnally incubating males. Compared to other cooperative avian societies, the division of reproduction in greater ani breeding groups is unusually egalitarian, despite marked inequalities in male parental care.
Can a weak retailer benefit from manufacturer-dominant retailer alliance?

Abstract The paper provides a framework to help the weak retailer delineate the circumstances that allow him to benefit from an alliance between the dominant retailer and the common manufacturer. We use a game-theoretic model to determine the optimal pricing and service strategies when channel members act independently then when the dominant retailer forms an alliance with the manufacturer. We find that: (i) the alliance is formed only if the market is not strongly competitive in terms of price, (ii) differentiation in terms of price and service is beneficial to all channel members under alliance, (iii) an interaction between spillover and service effects plays a crucial role to make the weak retailer gain or lose from the alliance.
Applications of the random phase approximation with the INDO/S Hamiltonian: UVVIS spectra of free base porphin

Abstract The nature of the Soret bands and higher excitation in the UV spectroscopy of porphines has been a source of interest for many years. Theoretical studies at a singles only level of configuration interaction (CIS) succeed for visible excitation energies but fail to unambiguously predict the disposition of the Soret and higher excitations. The random phase approximation (RPA) through the inclusion of doubles and maintaining a formal equivalence between length and velocity oscillator strengths, predicts both visible and Soret bands that conform to experiment. A comparison is made between CIS and RPA for the INDO/S level of approximation.
Compact and subelliptic estimates for the \({\overline{\partial}}\)-Neumann operator on C2 pseudoconvex domains

In this paper, we will show that Catlin’s property (P) implies regularity for the \({\overline{\partial}}\)-Neumann operator in W 1 on C 2 domains. We will also look at the subelliptic case and derive the natural generalization to C k domains when k ≥ 2.
The Movement We Make is the Community We Become: On Being an Activist in the Academy

As social justice educators we operate within an academy that often denies the necessity of activism in our work. In this article the author explores, through one person's story, how hierarchies of knowledge and status work within neoliberal paradigms to marginalize scholar–activists and embodied knowledge, and offers possible paths toward scholar-activism.
Nursing diagnoses and construct validity of pain, self-care deficit and impaired mobility.

Abstract Construct validity of the concepts of pain, self-care deficit and impaired mobility was examined in a study of 120 medical—surgical patients. Factors derived from a factor analysis of the empirical signs and symptoms were: pain-factor and self-care deficit/impaired mobility-factor. The pain-factor clearly showed discriminant validity by differentiating between those with and without Clinical Nurse Specialist (CNS)-identified diagnosis of pain. An overlap between the defining characteristics of the diagnoses of self-care deficit and impaired mobility has been suggested in the present sample of patients. Limitations of the study and recommendations for further research are described.
THE DEVELOPMENT OF SCHOOLED NARRATIVE COMPETENCE AMONG SECOND GRADERS

The ability to produce schooled narrative is closely related to students' literacy development and school success. This study examined young children's communicative competence in schooled narrative and the nature of its development. Participants were 21 second graders in a literature-based classroom. Four stories were collected from each child at equal intervals of the school year through a dictation procedure that taps their discursive knowledge of schooled narrative. These stories were analyzed for inclusion of a variety of linguistic markers that embody three essential features of schooled narrative - autonomy, conventionality, and specialized grammar. Results showed that participants demonstrated more familiarity with conventionality than with the other two features of schooled narrative. Their understanding of specialized grammar was particularly nascent. There was also considerable variation in their discursive competence in schooled narrative. Further, significant changes were observed during the ...
Identification of rate-limiting steps in cephalosporin C biosynthesis in Cephalosporium acremonium: a theoretical analysis

A kinetic model describing the biosynthesis of cephalosporin C in Cephalosporium acremonium has been developed to identify the rate-limiting step(s). Using this model and in-vitro kinetic data of the biosynthetic enzymes, the production kinetics of cephalosporin C were examined theoretically. The predicted time profile of the specific production rate during batch culture is in good agreement with that of experimental results published previously. Sensitivity analysis indicates that delta-(L-alpha-aminoadipyl)-L-cysteinyl-D-valine (ACV) synthetase is the rate-limiting enzyme. Our analysis also predicts that increasing ACV synthetase enhances the production rate initially until expandase/hydroxylase becomes rate-limiting. Furthermore, increasing expandase/hydroxylase reduces the accumulation of penicillin N, and thus, enhances the production of cephalosporin C. Based on our analysis, amplifying both ACV synthetase and expandase/hydroxylase concurrently should enhance the production rate to a great extent.
Electronic Reference Works and Library Budgeting Dilemma

SUMMARY The number of electronic resources has climbed up steadily in recent times. Some of these e-resources are reference sources, mostly in Science, Technology and Medicine (STM), which publishers convert to electronic for obvious reasons. The library budgets for materials usually have two main lines, budget for one time purchase (monographs) and budget for ongoing subscriptions (serials). It therefore becomes an issue when pricing model is not stable and this balance cannot be maintained. In understanding the importance of reference sources, this article examines the following: origin of reference service, information-seeking behavior of scientists and engineers, print versus online and user preference and expectations, nature accessibility and use of science reference texts, budgeting for and acquisitions of electronic science reference works. Do we have to adjust the budgets to accommodate the new trend or should publishers work within the framework of the library budgets? Some science librarians we...
A note on rearing juvenile chum salmon, Oncorhynchus keta, in an artificial upwelling system

Abstract Fry of chum salmon, Oncorhynchus keta , were reared in an artificial upwelling pond at a stocking density of one fry per cubic meter of water. Diatoms, primarily Chaetoceros sp., and a copepod, Acartia clausi , composed the food web in the pond. Fry averaging 0.6 g (wet weight) at introduction increased 1.9 g in the first 28 days, and 1.4 g in the second 28 days of the experiment. Mortality during the 56 days was less than 1%.
Pulmonary thromboembolism in childhood: a single-center experience from Turkey.

Objective This study was designed to evaluate the clinical characteristics, acquired and congenital risk factors, treatment strategies, and long-term outcome in pediatric pulmonary thromboembolism (PTE) cases followed in our center in Turkey. Subjects Of the total 470 pediatric patients with thrombosis referred to our center, 16 (3.4%) had PTE. The mean age of the children with PTE was 10.3 ± 6.8 years (range: 1.5–20.0, median: 10.5), and 12 (75.0%) were boys. Results The mean follow-up period was 28.9 ± 21.0 months (range: 3–66, median: 22). During the follow-up period, recurrence was observed in three children (18.8%). The mean time from the appearance of symptoms to accurate diagnosis was 6.4 ± 4.0 days (range: 2–10). Six patients (37.5%) were initially diagnosed as having pneumonia. After they were hospitalized and showed no clinical improvement with broad-spectrum antibiotic treatment, the accurate diagnosis of PTE was established. Of these 16 patients with PTE, 8 (50%) had associated thrombosis and 6 (37.5%) had congenital heart diseases. Infections including septic arthritis and osteomyelitis (n = 1), cytomegalovirus infection (n = 1), and infective endocarditis (n = 2) were detected in our patient group. In addition, two patients had a central venous line and one patient had obesity associated with malignancy. Other underlying diseases included thalassemia major, Behcet disease, antiphospholipid antibody syndrome, and autoimmune lymphoproliferative disorder in one patient each. Factor V G1691A heterozygous mutation was detected in two children, and methylene tetrahydrofolate reductase C677T homozygous mutation was detected in one child. A high level of factor VIII was the most common (8/16, 50%) laboratory risk factor in our patient group, and 12 children (75.0%) had a high D-dimer level. Among 16 children with PTE, one child had one, three children had two, five children had three, three children had four, and four children had five laboratory and/or clinical risk factors. Therefore, all children with PTE had at least one laboratory and/or clinical risk factor that facilitated development of thrombosis. In addition, according to the risk assessment for persistence or recurrence of venous thrombosis in children conducted by Manco-Johnson, 12 children (75%) with PTE in the present study had high-risk criteria. Conclusion When a child with thrombosis at any site of the body develops unexpected respiratory symptoms or pneumonia unresponsive to antibiotic treatment, imaging studies should be performed for diagnosis of PTE. Furthermore, thrombotic children with high-risk criteria should be followed closely for the development of PTE.
Understanding chromate reaction kinetics with corroding iron media using Tafel analysis and electrochemical impedance spectroscopy.

The kinetics of chromate removal from contaminated water by zerovalent iron media are not well understood. This study investigated the reactions occurring on iron surfaces in chromate solutions in order to understand the removal kinetics and to assess the long-term ability of zerovalent iron for removing Cr(VI) from contaminated water. Tafel polarization analysis and electrochemical impedance spectroscopy were used to determine the corrosion rates and charge-transfer resistances associated with Cr(VI) removal by iron wires suspended in electrolyte solutions with initial Cr(VI) concentrations of 10 000 μg/L. The condition of the iron surfaces at the time of their exposure to chromate determined the effectiveness of the iron for chromate removal. Both iron coated with a water-formed oxide and initially oxide-free iron were effective for chromate removal. However, iron coated with an air-formed oxide was an order of magnitude less effective for removing soluble chromium. Although iron with the air-formed oxi...
Visible surface reconstruction via local minimax approximation

Abstract Visible surface reconstruction is an important early stage in the processing and analysis of 3-D imagery, as it provides a compact and manipulable representation of the 3-D structure of perceived objects in a scene. In this paper, we describe an algorithm for reconstructing visible surfaces from scattered surface depth/orientation data using approximation methods. The basic unit of the proposed algorithm is a minimax approximation routine which operates over regions of local surface support. The minimax approach is attractive for several reasons and the computational cost is not high using fast algorithms. A window-based scheme is used to achieve a smooth surface reconstruction while maintaining discontinuities arising from object occlusions or sudden changes in surface orientation; the discontinuities are detected as part of the algorithm. Results of the technique as applied to several test objects are provided.
The Dynamical Consequences of Spontaneous Current Sheets in Quiescent Prominences

The solar corona is continually being injected with magnetic flux from the solar interior, flux that cannot be annihilated in bulk by the electrically highly conducting corona. Observations have shown that mass loss through downflows within solar prominences may be responsible for the ascent and eventual eruption of these prominences. Ascending small-scale structures as well as large-scale eruptions of prominences may both serve to carry excess magnetic flux out of the corona. We investigate the dissipation and field reconnection across the tangential discontinuities that form spontaneously in the supporting magnetic field of a prominence. Our analysis of a variety of postdissipation, nonequilibrium states provides instructive insights into the observable motions in prominences. The net effect of the magnetic reconnection is a downflow of mass accompanied by an upward transport of magnetic flux. This effect may play an important, direct and indirect, role in ejecting magnetic flux from the corona into interplanetary space. Shock waves are a natural consequence of this dissipative process, and their detection may serve as a diagnostic observational tool. Thin counterstreaming layers of prominence plasma predicted by this work have already been observed.
Copepod and chlorophyll a concentrations in receiving waters of a nuclear power station and problems associated with their measurement

Copepod and chlorophyll a concentrations were measured in the sea-water mixing zone of cooling water from a nuclear power plant and in a control area (containing no cooling water). No significant differences (P < 0.05) were observed between the two areas for these parameters; however, it is known that about 70% of the copepods and 80–100% of the phytoplanktonic photosynthesis are eliminated in the 95 000 m3/h of sea water entrained through the power plant. From the data collected, which consisted of five replicate plankton tows or chlorophyll measurements at each of four stations on five dates, we calculated that our sampling program was not able to detect the ca. 5% reduction that occurred in the population size. In fact, we calculate that about 300 plankton tows are required per station to measure a ±5% change in copepod concentrations, 75 tows for a ±10% change and 20 for a ±20% change. For chlorophyll a an average of 88 samples are needed per station to measure a ±5% change, 22 for a ±10% change and 6 for a ±20% change. Considering this, because of tidal currents in coastal areas and the difficulty of repeatedly sampling the same water mass, we feel that it is virtually impossible to measure relatively small (<±20%) changes in plankton densities. The number of chlorophyll a samples needed for a ±20% change is not prohibitive. These data indicate the importance of determining the ability of a sampling program to measure a population change before concluding that a suspected pollutant has not affected the population. The study also shows the inability of conventional methods of measuring plankton densities to detect relatively small changes.
Mg2+ modulates membrane sphingolipid and lipid second messenger levels in vascular smooth muscle cells

Abstract In vitro studies with smooth muscle cells from rat aorta and dog cerebral blood vessels indicate that variation in free Mg 2+ , within the pathophysiological range of Mg 2+ concentrations, found in human serum, causes sustained changes in membrane phospholipids and lipid second messengers. Incorporation of [ 3 H]palmitic acid into phosphatidylcholine (PC) and sphingomyelin (SM) was altered within 15–30 min after modifying the extracellular Mg 2+ ion level ([Mg 2+ ] o ). Decreased Mg 2+ produced a fall in both [ 3 H]SM and [ 3 H]PC over the first 2 h. After an 18-h incubation, the [ 3 H]PC/[ 3 H]SM ratio changed from about 20:1 to about 50:1. Increased [Mg 2+ ] o resulted in a 2- to 3-fold increase in [ 3 H]SM compared to only a small increase in [ 3 H]PC over the same period. There was a reciprocal relationship between [ 3 H]ceramide and [ 3 H]1,2-DAG levels with highest [ 3 H]ceramide and lowest [ 3 H]-1,2-DAG levels seen at lowest [Mg 2+ ] o . The results indicate that a fall in extracellular ionized Mg 2+ concentration produces a rapid and sustained decrease in membrane sphingomyelin and a moderate rise in intracellular ceramide. A major effect of lowering [Mg 2+ ] o appears to be a down-regulation of SM synthase. The increased membrane SM content and a concomitant decrease in cell ceramide, in the presence of elevated [Mg 2+ ] o , may be relevant to the apparent protective role of adequate Mg intake on vascular function in humans.