cssi/SciSciGPT-SciSciNet huggingface dataset:
Enhanced energy transfer by near-field coupling of a nanostructured metamaterial with a graphene-covered plate

Abstract Coupled surface plasmon/phonon polaritons and hyperbolic modes are known to enhance radiative transfer across nanometer vacuum gaps but usually require identical materials. It becomes crucial to achieve strong near-field energy transfer between dissimilar materials for applications like near-field thermophotovoltaic and thermal rectification. In this work, we theoretically demonstrate enhanced near-field radiative transfer between a nanostructured metamaterial emitter and a graphene-covered planar receiver. Strong near-field coupling with two orders of magnitude enhancement in the spectral heat flux is achieved at the gap distance of 20 nm. By carefully selecting the graphene chemical potential and doping levels of silicon nanohole emitter and silicon plate receiver, the total near-field radiative heat flux can reach about 500 times higher than the far-field blackbody limit between 400 K and 300 K. The physical mechanism is elucidated by the near-field surface plasmon coupling with fluctuational electrodynamics and dispersion relations. The effects of graphene chemical potential, emitter and receiver doping levels, and vacuum gap distance on the near-field coupling and radiative energy transfer are analyzed in detail.
The interpretation of pictures of freeze-fractured biological material.

Knowing the location of the fracture planes when applying the freeze-fracture technique is of paramount importance when making use of the observations made to deduce the structure of cellular membranes. Freeze-fracture analysis of a number of membranes with very different functions that was performed in our laboratory, had led to the conclusion that there was no unique location of the fracture plane relative to the membranes. The most common type of fracture face appeared to expose the surfaces of membranes and not their interior. This made it justified to subject to a critical examination the commonly accepted concept of a splitting of membranes through their middle during fracturing. This examination led to the conclusion that the experiments that have been referred to as proving the intramembrane splitting can be severely criticized, and in fact can be used to prove that intramembrane splitting has not occurred. The layer that appears after etching can be identified as a layer of contamination formed by solutes that are freed by the sublimation of water. It can be ruled out as being a layer belonging to the membrane. An approach to the problem of locating the fracture faces is described which is based on a refusal to accept any preconceived attitude. Instead, the location of fracture planes should be determined individually in each case on the basis of observations pertaining to that case. Certain rules are presented for locating the fracture faces. Furthermore, the experimental conditions for freeze-fracturing, the interpretation of the topography of the fracture faces, the problem of complementarity, and the limitations of the method with respect to resolution are discussed briefly. The conclusion is that the freeze-fracture technique makes use of only a fraction of the resolving power of the electron microscope and that it is pertinent that other preparatory methods are worked out with the aim of making a further use of the performance of the electron microscope.
Examination of pigments on Thai manuscripts: the first identification of copper citrate

Samples from Thai manuscripts dated to the 18th to 20th century were analyzed by Raman spectroscopy and Fourier-transform infrared spectroscopy (FTIR) to determine the pigments used. This suggested a change in palette from the 18th to 20th century, with use of imported pigments in the later manuscripts. In the 18th century, the main green used was an organic copper salt, which was replaced by emerald green and mixtures of Prussian blue with gamboge, chrome yellow and zinc yellow (zinc potassium chromate). Chrome yellow was used in addition to gamboge in one later 19th century manuscript. Similarly, indigo in the 18th century manuscripts was replaced by Prussian blue and then synthetic ultramarine in the 19th century manuscripts. Lead white was the main white pigment in all but one manuscript, which contained huntite, a magnesium calcium carbonate. Huntite also occurred in mixtures with other pigments in two other manuscripts. In all the works studied, red lead, vermilion and red earth were used for red, orange and pink shades and red earth in brown areas. The organic copper salt used in the 18th century gave good FTIR spectra but could not initially be matched with any published compound. X-ray diffraction (XRD) suggested this was a copper citrate phase, and examination of the literature showed that the FTIR spectra matched those published for a hydrated copper citrate. Raman spectra were obtained from this organic copper salt, which showed close agreement with those obtained from synthetic copper citrate. Copper citrate has not been identified previously as an artist's material, although its use has been postulated on the basis of historical texts. Minor copper formate and/or copper chloride were also identified by XRD and scanning electron microscopy (SEM) in some green samples containing copper citrate. Copyright © 2008 John Wiley & Sons, Ltd.
Casting Light on Cube Dissections

(2009). Casting Light on Cube Dissections. Mathematics Magazine: Vol. 82, No. 5, pp. 323-331.
Becoming ‘100% American’: negotiating ethnic identities through nativist discourse1

This study traced the negotiation of national and ethnic identities in the USA in the early twentieth century – a time of intense anti-immigrant and anti-German war sentiment. The public discourse analyzed centered around a particularly infamous ban on all non-English languages in the state of Iowa. This ban symbolized the hegemonic definition of national identity at the time, one that implicitly equated national identity to Anglo ethnicity. Alternatively, non-Anglos re-positioned ethnic differences through a discourse of patriotism (e.g., praying in a ‘foreign’ language for US victory in the war was an innocent practice of ethnic difference in the service of the nation). Equating ethnic differences to patriotism, however, resulted in the de-legitimization and erasure of non-Anglo ethnic identities. By pointing to past discursive struggles to define national identity featuring ethnic groups who are today readily accepted as ‘American’ (e.g., German-Americans), we can recast today's predominant and highly ...
Gastric secretion of acid in response to right and left atrial infusion of gastrin

The purpose of this study was to evaluate the possible role of the lung as an organ for inactivation of exogenous gastrin. Human synthetic gastrin was infused into the right and left atria of 4 mongrel dogs with Heidenhain pouches. The mean rate of acid secretion in response to right atrial gastrin infusion was 0.39 mEq/15 min, as compared to the mean rate of 0.36 mEq/15 min when the gastrin was infused via the left atrium. The difference in gastric acid secretory response to infusion of gastrin into the right or left atrium was not statistically significant.
Postoperative wound infection: Prediction of some responsible organisms*

Summary A long, carefully controlled study of the efficacy of a systemic antibiotic (cephaloridine) in the prevention of wound infection after elective gastrointestinal operations allowed some detailed microbiologic study of the patients and their wounds. Routine culture of subcutaneous tissue after fascial closure in such operations is valuable in predicting some of the organisms that will be present if clinical sepsis develops after operation. Such cultures are likely to be available to the clinician when clinical sepsis is first suspected, and he may well make the selection of the antibiotic more intelligently pending the ultimate diagnosis of the illness and the determination of its causes. Infection as seen in this study was regularly associated with multiple strains of bacteria. No conclusions can be drawn regarding the significance of anaerobic sepsis.
Ultrastructural, histochemical, and freeze-fracture evaluation of multilamellated structures in human pulmonary alveolar proteinosis.

Ultrastructural, histochemical, and freeze-fracture studies of material recovered by bron-choalveolar lavage from patients with pulmonary alveolar proteinosis revealed four types (A, B, C, and D) of multilamellated structures (MS). Type A, the major component, consisted of concentric, trilaminar structures which were composed of two electron-dense layers and a central lucent layer (5.7–7.5 nm in overall width) alternating with wider (25–30 nm) electron-lucent intervening layers. Type B MS were formed by concentric lamellae with a 5–5.3-nm periodicity. Type C MS were composed of wavy, electron-dense lamellae with a 4–4.5-nm periodicity. Type D MS were conglomerated masses of intricately arranged double or triple electron-dense layers (7.5–13.5 nm wide) alternating with wider (30–40-nm) electron-lucent layers. The electron-dense lamellae of type A, type C, and type D MS were stained with ruthenium red, the Thiery method, and concanavalin A, indicating the presence of carbohydrate components. Freeze-fracture studies revealed smooth inner and outer surfaces in type A MS, with the fracture planes passing through the central parts of the trilaminar structures; the intervening layers contained 10-nm particles, which probably are proteins. Type B MS had smooth surfaces, and type C MS had slightly particulate surfaces; while type D MS showed tubular or polygonal structures, 350 nm wide, with rows of particles 7–8 nm in diameter. It is concluded that type A and type D MS contain proteins and carbohydrates, probably in the form of glycoproteins, as well as phos-pholipids, and are related to tubular myelin. Type B and type C MS are considered to contain mainly phos-pholipids; type C MS are also considered to contain carbohydrates and to be related to lamellar bodies of type II alveolar epithelial cells.
Behavior of unacquaintedSaimiri troops upon encounter: A suggestive case study

When primate societies merge, the probabilities of genetic combinations are altered. What occurs when previously unacquainted groups meet is a product of the social organization of the species and a major contributor to genetic variance. Two colonies ofSaimiri sciureus that had lived independently for five to seven years were permitted to meet. One colony was subjected to injurious aggression by a second colony. We suggest that the demographic characteristics of the groups are suggestive determinants of the acceptance or rejection of unfamiliarSaimiri.
Positioning Library Data for the Semantic Web: Recent Developments in Resource Description

Recent developments in resource description standards and technologies have aimed at moving cataloging practice to the Web environment and making library data available for exchange and reuse on the Semantic Web. As the library community looks outward and forward, library standards and technologies are converging with Web practices in three areas: content description, data models, and data exchange. This article captures the essence of the core standards and technologies that underlie the daily work of practitioners of library service, including Resource Description and Access, Functional Requirements for Bibliographic Records, the Linked Data environment, Resource Description Framework, and the Bibliographic Framework Transition Initiative. The article will discuss their intersections with existing practice during this period of transition as well as their potential impacts on the future cataloging practice.
The Prognostic Importance of the Number of Dissected Lymph Nodes After Induction Chemoradiotherapy for Esophageal Cancer

Background Analyses of adequacy of lymph node dissection during resection of esophageal cancer are based on patients who have not undergone induction chemoradiotherapy. We sought to determine the minimum number of dissected lymph nodes necessary to ensure adequate staging after induction chemoradiotherapy. Methods A prospectively maintained thoracic surgery database was queried to identify consecutive patients undergoing postinduction esophagectomy from 1996 to 2010. Cox proportional hazard and recursive partitioning survival analyses were performed. Results Complete lymph node data were available for 395 patients. Mean age was 59.5 years, and 64 patients (16%) were female. The median number of dissected lymph nodes was 8 (range, 0 to 63). When pathologic (p)T stage, pN stage, and the number of dissected lymph nodes were used as predictors, only pN stage (odds ratio, 1.3; 95% confidence interval, 1.2 to 1.7) and age (odds ratio, 1.03; 95% confidence interval, 1.01 to 1.04) independently predicted survival. Recursive partitioning was performed on 262 pN0 patients using T stage and the number of dissected lymph nodes as predictors. No pN0 patient with 28 lymph nodes dissected died during follow-up. For patients with fewer than 28 lymph nodes dissected, the next prognostic factor was T stage. For pT1-2 N0 patients, the number of lymph nodes dissected did not affect survival. For pT3-4 N0 patients, a significant survival decrement was noted for patients with fewer than 7 lymph nodes dissected compared with those with more than 7 lymph nodes dissected. Conclusions T stage determines prognosis in postinduction pN0 patients with fewer than 28 lymph nodes evaluated. Postinduction pT3N0 patients with fewer than 7 lymph nodes evaluated are understaged.
Including technical and security risks in the management of information systems: A programmatic risk management model

Developing and managing information systems have always been challenging, but increased security concerns and tighter budget resources have made these tasks even more difficult in recent years. Increased networking, mobility, and telecommuting, while beneficial to business productivity, have introduced serious technical issues and potential security problems. The software risk assessment literature has focused primarily on managerial risks, while security risk models have generally excluded these risks and the associated implementation costs. In addition, the social components of decision-making under risk (e.g., a corporate culture that rewards only on-time, on-budget software delivery) have proven to be a primary risk driver in many environments. On the basis of a high-level risk analysis model, this paper provides a framework that permits assessment and management of the critical risks of technical failures and security breaches of information systems, in conjunction with the managerial risks of exceeding the levels of resources allocated to their development. To do so, we consider explicitly the tradeoffs involved and the effects of resource constraints on system reliability and security. © 2004 Wiley Periodicals, Inc. Syst Eng 8: 15–28, 2005
High temperature limits in vivo pollen tube growth rates by altering diurnal carbohydrate balance in field-grown Gossypium hirsutum pistils.

Abstract It has recently been reported that high temperature slows in vivo pollen tube growth rates in Gossypium hirsutum pistils under field conditions. Although numerous physical and biochemical pollen–pistil interactions are necessary for in vivo pollen tube growth to occur, studies investigating the influence of heat-induced changes in pistil biochemistry on in vivo pollen tube growth rates are lacking. We hypothesized that high temperature would alter diurnal pistil biochemistry and that pollen tube growth rates would be dependent upon the soluble carbohydrate content of the pistil during pollen tube growth. G. hirsutum seeds were sown on different dates to obtain flowers exposed to contrasting ambient temperatures but at the same developmental stage. Diurnal pistil measurements included carbohydrate balance, glutathione reductase (GR; EC 1.8.1.7), soluble protein, superoxide dismutase (SOD; EC 1.15.1.1), NADPH oxidase (NOX; EC 1.6.3.1), adenosine triphosphate (ATP), and water-soluble calcium. Soluble carbohydrate levels in cotton pistils were as much as 67.5% lower under high temperature conditions (34.6 °C maximum air temperature; August 4, 2009) than under cooler conditions (29.9 °C maximum air temperature; August 14, 2009). Regression analysis revealed that pollen tube growth rates were highly correlated with the soluble carbohydrate content of the pistil during pollen tube growth ( r 2 = 0.932). Higher ambient temperature conditions on August 4 increased GR activity in the pistil only during periods not associated with in vivo pollen tube growth; pistil protein content declined earlier in the day under high temperatures; SOD and NOX were unaffected by either sample date or time of day; pistil ATP and water soluble calcium were unaffected by the warmer temperatures. We conclude that moderate heat stress significantly alters diurnal carbohydrate balance in the pistil and suggest that pollen tube growth rate through the style may be limited by soluble carbohydrate supply in the pistil.
Peptidomimetic Probes and Molecular Modeling Suggest That Alzheimer's γ-Secretase Is an Intramembrane-Cleaving Aspartyl Protease†

The amyloid β-protein (Aβ), implicated in the pathogenesis of Alzheimer's disease (AD), is a proteolytic metabolite generated by the sequential action of β- and γ-secretases on the amyloid precursor protein (APP). The two main forms of Aβ are 40- and 42-amino acid C-terminal variants, Aβ40 and Aβ42. We recently described a difluoro ketone peptidomimetic (1) that blocks Aβ production at the γ-secretase level [Wolfe, M. S., et al. (1998) J. Med. Chem. 41, 6−9]. Although designed to inhibit Aβ42 production, 1 also effectively blocked Aβ40 formation. Various amino acid changes in 1 still resulted in inhibition of Aβ40 and Aβ42 production, suggesting relatively loose sequence specificity by γ-secretase. The alcohol counterparts of selected difluoro ketones also lowered Aβ levels, indicating that the ketone carbonyl is not essential for activity and suggesting that these compounds inhibit an aspartyl protease. Selected compounds inhibited the aspartyl protease cathepsin D but not the cysteine protease calpain, ...
Livedo reticularis and related disorders.

Livedo reticularis is a violaceous mottling of the skin with a “fishnet” reticular appearance. Primary and secondary etiologies exist, including a pathologic variant termed livedo racemosa. No evidence-based medicine exists to guide therapy for this disorder, but most patients with primary and secondary livedo reticularis are asymptomatic and do not require treatment. In the rare instance that a patient with primary livedo reticularis experiences mild symptoms such as episodic numbness and tingling, avoidance of cold and vasoconstricting substances should be encouraged. Lastly, judicious dosing of a vasodilator such as a calcium channel blocker can be prescribed. Patients with secondary livedo reticularis or livedo racemosa may benefit from these same therapeutic suggestions; however, treating the proximate cause of livedo with a systemic association is encouraged and is most likely to yield cutaneous improvement. Although antiplatelet and/or anticoagulant therapy is often required when treating a patient with the antiphospholipid antibody syndrome or Sneddon’s syndrome, the attendant livedo racemosa typically remains unchanged or progresses despite this treatment.
Hepatitis E virus infection prevalence among selected populations in Iowa.

Abstract Background: HEV causes an enteric infectious disease endemic in developing areas with hot climate. A case of endogenous HEV infection has been reported in the US. Recently, HEV-like virus was isolated from swine in Iowa. Swine production is a major industry in Iowa with the potential for human exposure to swine in and around industrial and family farm operations. Objective: The study objective was to determine whether individuals in Iowa are exposed to HEV. Study design: Anti-HEV antibody prevalence in four selected Iowa populations was determined. Sera were collected from 204 patients with non-A, non-B, non-C hepatitis (non-A–C); 87 staff members of the Department of Natural Resources (DRN); 332 volunteer blood donors in 1989; and 111 volunteer blood donors in 1998. All sera were tested for anti-human HEV IgM and IgG by ELISA with confirmation of positivity by a peptide neutralization test. Results: Both the patients with non-A, non-B, non-C hepatitis (4.9%) and the healthy field workers from the Iowa DNR (5.7%) showed significantly higher prevalence of anti-HEV IgG antibodies compared to normal blood donor sera collected in 1998 ( P Conclusions: Human HEV or a HEV-like agent circulates in the Iowa geographical area. At-risk human populations with occupational exposure to wild animals and environmental sources of domestic animal wastes or with unexplained hepatitis have increased seroprevalence of HEV antibodies.
Extracellular bone matrix-derived growth factor

Abstract Demineralized extracellular bone matrix, when implanted subcutaneously into allogeneic rats, induces an invariant sequence of events resulting in de novo cartilage, bone and bone marrow formation. We have recently demonstrated the dissociative extraction and successful biological reconstitution of boneinducing molecule(s) in demineralized bone matrix. As mesenchymal cell proliferation precedes differentiation of endochondral bone, we have examined the bone-inductive molecules for mitogenic activity on human and rat fibroblasts and bovine endothelial cells. The results revealed that the molecular fraction obtained by molecular sieve chromatography on Sepharose CL-6B responsible for endochondral bone induction is capable of stimulating human and rat fibroblasts proliferation by 2500 and 300 % respectively, as compared to cells grown in a serum-free medium. Endothelial cells do not seem to share this response. This factor exhibits a significant effect on growth-promoting activity for both human and rat fibroblasts at a dose of 0.5 ng protein/ml of culture medium. These results demonstrate the presence of a tightly bound growth factor in the extracellular bone matrix.
A cryptanalytic time-memory trade-off

A probabilistic method is presented which cryptanalyzes any N key cryptosystem in N^{2/3} operational with N^{2/3} words of memory (average values) after a precomputation which requires N operations. If the precomputation can be performed in a reasonable time period (e.g, several years), the additional computation required to recover each key compares very favorably with the N operations required by an exhaustive search and the N words of memory required by table lookup. When applied to the Data Encryption Standard (DES) used in block mode, it indicates that solutions should cost between 1 and 100 each. The method works in a chosen plaintext attack and, if cipher block chaining is not used, can also be used in a ciphertext-only attack.
Secondary dissociation pathways of ethylsilylene radical on ground and excited state potential energy surfaces

Decomposition pathways of ethylsilylene intermediate are examined with the aim of understanding what are dissociation pathways for the formation of silylene and silicon atoms. Implications for the interpretation of decomposition mechanisms for ethylsilane from experimental studies are discussed.
Histologic responses in human skin test reactions to ragweed: IV. Effects of a single intravenous injection of steroids

Abstract A controlled study has been carried out dealing with the early effects of a single intravenous dose of either methylprednisolone or placebo on newly developed and ongoing cellular inflammatory responses in immediate hypersensitivity skin test reactions. There was no significant difference in the tissue eosinophil responses to ragweed injected 2 hr before and 2 hr after placebo; there was a significant rise (101% ± 39) from the second to fourth hour after antigen injection. By contrast, there was a marked decrease in the tissue eosinophil response to antigen injected 2 hr after steroids as compared to the pattern seen in the presteroid reaction. In addition, the eosinophil numbers not only did not increase from the second to fourth hour when steroids were injected at the second hour but decreased markedly. These findings suggest early suppressive effects on tissue eosinophil responses within 2 hr after steroid were administered intravenously. Also, there may be trafficking of eosinophils both into and out of these inflammatory sites during the first hours after intradermal antigen injection.
Renewal-Reward Process Formulation of Motor Protein Dynamics

Renewal-reward processes are used to provide a framework for the mathematical description of single-molecule bead-motor assays for processive motor proteins. The formulation provides a more powerful, general approach to the fluctuation analysis of bead-motor assays begun by Svoboda et al. (Proc. Natl. Acad. Sci. USA 91(25):11782, 1994). Fluctuation analysis allows one to gain insight into the mechanochemical cycle of motor proteins purely by measuring the statistics of the displacement of the cargo (e.g., bead) the protein transports. The statistical parameters of interest are shown to be the steady-state slopes (in time) of the cumulants of the bead (the cumulant rates). The first two cumulant rates are the steady-state velocity and slope of the variance. The cumulant rates are shown to be insensitive to experimental disturbances such as the initial state of the enzyme and from the viewpoint of modeling, unaffected by substeps. Two existing models—Elston (J. Math. Biol. 41(3):189–206, 2000) and Peskin and Oster (Biophys. J. 68(4):202S–211S, 1995)—are formulated as renewal-reward processes to demonstrate the insight that the formulation affords. A key contribution of the approach is the possibility of accounting for wasted hydrolyses and backward steps in the fluctuation analysis. For example, the randomness parameter defined in the first fluctuation analysis of optical trap based bead-motor assays (Svoboda et al. in Proc. Natl. Acad. Sci. USA 91(25):11782, 1994), loses its original purpose of estimating the number of rate-determining steps in the chemical cycle when backward steps and wasted hydrolyses are present. As a simple application of our formulation, we extend the randomness parameter’s scope by showing how it can be used to infer the presence of wasted hydrolyses and backward steps with certainty. A more powerful fluctuation analysis using higher cumulant rate measurements is proposed: the method allows one to estimates the number of intermediate reactions, the average chemical rate, and the probability of stepping backward or forward. The stability of the method in the presence of measurement errors is demonstrated numerically to encourage its use in experiments.
Dual activation of PPARα and PPARγ by mono-(2-ethylhexyl) phthalate in rat ovarian granulosa cells

Abstract Peroxisome proliferator-activated receptors (PPARs) are key regulators of lipid metabolism and cell differentiation. The plasticizer di-(2-ethylhexyl) phthalate is a peroxisome proliferator, and its active metabolite mono-(2-ethylhexyl) phthalate (MEHP) activates PPARα and PPARγ in cell transactivation assays. MEHP is a female reproductive toxicant and decreases activity, mRNA, and protein levels of aromatase, the rate-limiting enzyme that converts testosterone to estradiol in ovarian granulosa cells. To test the hypothesis that MEHP suppresses aromatase through PPAR pathways, granulosa cells were cultured with MEHP (50 μM) or selective activators of PPARγ or PPARα for 48 h and gene expression was analyzed by real time RT-PCR. Both PPARα and PPARγ activators significantly decreased aromatase mRNA and estradiol production like MEHP. The PPARγ-selective antagonist GR 259662 partially blocked the suppression of aromatase by MEHP, suggesting that MEHP acts through PPARγ, but not exclusively. MEHP and the PPARα-selective agonist GW 327647 induced expression of 17β-hydroxysteroid dehydrogenase IV, a known PPARα-regulated gene, and induction was maintained with addition of the PPARγ-selective antagonist. PPARα-selective activation also induced expression of aryl hydrocarbon receptor (AhR), CYP1B1, and epoxide hydrolase in the granulosa cell. These data support a model in which MEHP activates both PPARα and PPARγ to suppress aromatase and alter other genes related to metabolism and differentiation in the granulosa cell.
Effect of dehydroepiandrosterone (DHEA) on intestinal mucosal immunity in young adult and aging rats

The present study assesses the effectiveness of oral DHEA on the intestinal mucosal immune response in aging rats. Young adult (6 months) and aging (21 months) female rats received powdered rat chow with or without 0.2% DHEA for 23 days. The animals were immunized intraduodenally with either cholera toxin (CTx) or vehicle alone and boosted two weeks later. Seven days after boosting, serum, bile, small intestinal tissue, and liver were collected for analysis. Anti-CTx IgA antibody titers were measured in serum and bile and the concentration of anti-CTx antibody containing cells (ACCs) in the small intestinal lamina propria and liver were determined by quantitative immunohistochemistry. Intergroup comparisons indicated that there was only one significant difference in serum and none in bile anti-CTx IgA titers between CTx-immunized animals fed DHEA or the diet alone. Immunohistochemical analysis determined that the density and distribution patterns of ACCs within the lamina propria were unaffected by DHEA. Both DHEA-treated and control young immunized animals exhibited similar numbers of ACCs. Only 40% of the aging rats responded to intraduodenal immunization with CTx, as determined by the presence of ACCs in the intestine, regardless of the presence or absence of DHEA in the diet. These data suggest that DHEA in the diet does not enhance the intestinal mucosal immune response to intraduodenal CTx in either young adult or aging rats.
Patterns of Dental Caries in Osborne-Mendel and NIH Black Rats in Relation to Length of the Caries Test Period

Both Osborne-Mendel and NIH Black rats developed carious lesions on the smooth surfaces and in the sulci during the first week on an intensive caries-test challenge. The number and size of lesions continued to increase throughout a ten week experiment. Progression on different surfaces varied with the strain, but final levels were not significantly different.
To reconstruct or not to reconstruct

In the opening scene of the movie “Dances with Wolves,” dazed Union Army soldiers with mangled limbs are laid out, resigned to their turn at the surgeon's cleaver. This scene is typical of health c...
Two Instructional Models That Teachers Can use to Promote & Support Scientific Argumentation in the Biology Classroom

We describe two instructional techniques that science teachers can use to promote and support scientific argumentation inside the classroom. These techniques are designed to give students an opportunity to establish or validate a claim on the basis of reasons or to propose, support, evaluate, and refine a claim as part of a group. The description of the techniques includes two example lessons and suggestions for teachers.
Neocarzinostatin abstracts a hydrogen during formation of nucleotide 5′-aldehyde on DNA

The oxidative reaction of polydeoxyadenylic-deoxythymidylic acid [poly(dA-dT)] with neocarzinostatin that produces 5'-thymidine aldehyde esterified to the 5'-end of strand breaks proceeds with hydrogen abstraction. The abstracted hydrogen is covalently bound to the non-protein component of neocarzinostatin; only a small amount (5%) is washed out into solvent. These data rule out a peroxyl radical as the primary DNA damaging species involved in the production of the 5'-aldehyde group. In contrast to earlier reports, it is demonstrated that alpha-tocopherol is not an inhibitor of the reaction.
Acute appendicitis: An analysis of 417 consecutive cases

Abstract A statistical analysis of 417 consecutive cases of proved acute appendicitis is made. The distribution in sex, color and age groups is stated. An outline of the usual method of treatment is given. The signs, symptoms, temperature, pulse, respiration, duration of symptoms and use of cathartics are analyzed. At operation the McBurney incision is used almost exclusively when the diagnosis is certain. When drainage is employed, the tendency is to suture the peritoneum only. Wound infections, bacteriology and complications are presented. There were fourteen deaths or an incidence of 3.3 per cent in the entire series. There were no deaths in 300 unruptured cases; ten deaths out of seventy or an incidence of 14.2 per cent in the group with spreading peritonitis and four out of fortyseven or an incidence of 8.5 per cent in the group with abscess. A brief report of each case in which death occurred is given.
The Status of Computer Use in Business Commu nication Instruction

The results of an ABC Undergraduate Studies Committee survey of members to determine the status of computer use in business communication courses are presented in this article. The majority of business communication instructors require students to complete all assignments on the com puter, and some instructors provide software training. Stu dents predominantly are using WordPerfect on networked IBM or IBM-compatible computers in labs managed by the college.
Textmasters: Bringing Literature Circles to Textbook Reading Across the Curriculum

A fifth-grade science teacher and university researcher challenged the notion that textbook reading follows the same archaic formula: read the textbook and answer the questions at the end of the section. Together, they adapted literature circle roles to fit textbook structures, resulting in the strategy they call Textmasters. This article describes the strategy, along with the action research project that proves its efficacy in the content area middle school classroom. تلخيص البحث: لقد تحدى معلم صف خامس علمي وباحث جامعي المفهوم بأن قراءة كتابة الصف تتبع نفس المعادلة القديمة: إقرأ الكتاب وأجب عن الأسئلة في نهاية القسم. وكيفا المعلمان أدوار حلقات أدبية لتناسب تراكيب كتابة الصف الأمر الذي أدى إلى إستراتيجية تمت تسميتها بـ((تكست ماسترز)) أي خبراء النصوص. إذ تصف هذه المقالة الإستراتيجية علاوة على مشروع البحث المنشط الذي يثبت فعاليته في سياق مجال المحتوى في صفوف المدرسة الإعدادية. 一位任教小学五年级科学科的教师与一位大学研究员，质疑课本阅读教学遵循同一陈旧公式这观念：首先阅读课本，然后回答章节末尾的问题。他们为切合课本结构所需，参照进行文学圈教学法时学生所分担的任务，一起编成了他们称之为「科学科文本阅读讨论主持人」这阅读教学策略。本文旨在描述该教学策略，并报告一项行动研究，以验证该教学策略在中学学科内容教室里所产生的效能。 Un professeur de sciences de cinquieme annee et un chercheur a l'universite ont fait le pari que la lecture des livres de textes choisis suit une meme formule archaique: lire le manuel et repondre aux questions a la fin du passage. Ensemble, ils ont adapte les roles des cercles de lecture pour s'ajuster a la structure du manuel, d'ou a resulte une strategie qu'ils ont appele les maitres textes. Cet article decrit cette strategie, ainsi qu'un projet de recherche action qui met en evidence son efficacite pour les disciplines enseignees au college. Учитель естествознания, работающий с пятиклассниками, и ученый, работающий в университете, бросили вызов многовековому алгоритму: “прочитай учебник и ответь на вопросы по прочитанному”. Их ученики начали читать предметные тексты так, как это обычно делается в литературных кружках, и в результате возникла стратегия под названием “текст-мастер”. B статье разъясняется сама стратегия и описано практическое исследование, подтверждающее ее эффективность для обучения различным предметам в средних классах школы. Un maestro de ciencias de quinto grado y un investigador universitario ponen en tela de juicio la idea que la lectura de textos sigue la misma formula arcaica: Leer el texto y contestar preguntas al final de la seccion. Juntos, ellos adaptaron los roles de circulos de lectura para conformarlos a la estructura del texto, resultando en una estrategia que denominaron Textmasters. Este articulo describe la estrategia junto con el proyecto de investigacion que prueba su eficacia en el area de contenido del salon de clase a nivel intermedio.
Philpapers Breaks New Ground for Discipline Based Repositories

This is the first in a series of columns intended to report on the progress of the Open Access (OA) movement in scholarly communication, chart the changes OA brings to the methods libraries and library users employ to acquire information, and estimate the value of OA materials for undergraduate library collections. At this point, it is not clear how long commercially published academic journals will be a sine qua non for college libraries. However, it is already obvious that undergraduate instruction can benefit from the scholarship available through Open Access at the same time that our libraries need the budget relief such resources offer. Librarians who work with undergraduates have very good reasons to stay current with the range and quality of OA content as well as with the best means of providing access to that body of scholarship. In addition, faculty teaching undergraduates depend upon librarians to keep them informed about changes in the information environment. With that in mind, “Out in the Ope...
Heat resistance of Clostridium perfringens vegetative cells as affected by prior heat shock.

This study quantified the heat resistance and the effects of heat shock on the subsequent heat resistance of 10 strains of Clostridium perfringens. Beef gravy samples inoculated with vegetative cells of the pathogen were subjected to sublethal heating at 48Cfor 10 min, and then heated to a final temperature of 58C using a submerged-coil heating apparatus. Heat-treated samples were spiral plated on Shahidi-Ferguson Perfringens agar to determine surviving bacterial population. No correlation between the heat resistance and the origin of the C. perfringens could be established due to significant variations in the heat resistance among strains. Inactivation kinetics of both heat-shocked and nonheat-shocked samples exhibited log-linear decline in the number of surviving cells with time. D-values at 58C for C. perfringens vegetative cells ranged from 1.21 to 1.60 min. Heat shocking allowed the organism to survive longer and the increase in heat resistance was as high as 1.5 fold. Also, heat shock resulted in the overexpression of proteins exhibiting epitopic and size similarity to E. coli GroEL and B. subtilis small acid soluble proteins. Increased heat resistance due to heat shock must be considered while designing cooking/reheating regimes that ensure safety of ready-to-eat foods contaminated with high numbers of C. perfringens vegetative cells. Les effets du choc thermique sur la resistance thermique de Clostridium perfringens est etudiee. De la sauce a subi un traitement a 48° pendant 10 min, puis a ete chauffe a 58°. La survie des C.perfringens est testee. Le choc thermique ameliore la survie et provoque une augmentation de la resistance thermique des bacteries. Le mecanisme fait intervenir la surexpression des chaperones similaires a GroEL de E.coli.
Association of fibrin and interleukin 8 in human oral squamous cell carcinoma

Abstract Objective. We have recently demonstrated that fibrin induces a specific, dose- and time-dependent upregulation of the angiogenic factor interleukin 8 (IL-8) from human oral squamous cell carcinoma (OSCC) cells in vitro. In this study we begin to test the hypothesis that fibrin induces IL-8 expression from tumor cells in vivo by studying their in vivo association in OSCC. Study design. The presence of fibrin(ogen) was initially evaluated in 20 archival human OSCCs by means of immunohistochemistry with a polyclonal antibody. The presence of fibrin and IL-8 was then studied in 19 sections from 8 different patients' head and neck tumors (including 6 OSCCs) by means of immunohistochemistry with a monoclonal antibody against fibrin. These 8 tumors had been treated with inhibitors of new fibrin formation and degradation immediately after surgical removal. Results. Fibrin staining was found in 100% of the tumor sections tested. IL-8 staining was found in the cytoplasm of tumor cells in 100% of the studied tumors, including areas adjacent to fibrin. Conclusions. These data demonstrate an in vivo association between fibrin and IL-8 in OSCC. These studies support our hypothesis that fibrin induces expression of protumorigenic factors such as IL-8 from tumor cells in vivo. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2003;95:452-7)
GABAergic and glycinergic presympathetic neurons of rat medulla oblongata identified by retrograde transport of pseudorabies virus and in situ hybridization.

Electron microscopy suggests that up to half the synaptic input to sympathetic preganglionic neurons (SPGNs) is GABAergic or glycinergic. A proportion of this input is suspected to originate from neurons located within the medulla oblongata. The present study provides definitive evidence for the existence of these supraspinal presympathetic (PS) neurons with inhibitory phenotypes. PS neurons were identified by retrograde trans-synaptic migration of pseudorabies virus (PRV) injected into the adrenal gland. GABAergic or glycinergic cell bodies were identified by the presence of glutamate decarboxylase (GAD)-67 mRNA or glycine transporter (GlyT)-2 mRNA detected with in situ hybridization (ISH). Neither GABAergic nor glycinergic PS neurons were tyrosine hydroxylase (TH)-immunoreactive (ir). GABAergic PS neurons were located within the ventral gigantocellular nucleus, gigantocellular nucleus alpha, and medial reticular formation, mostly medial to the TH-ir PS neurons. About 30% of GABAergic PS neurons were serotonergic cells located in the raphe pallidus (RPa) and parapyramidal region (PPyr). Glycinergic PS neurons had the same general distribution as the GABAergic cells, except that no glycinergic neurons were located in the RPa or PPyr and none were serotonergic. PRV immunohistochemistry combined with ISH for both GlyT2 and GAD-67 mRNAs showed that at least 63% of midline medulla GABAergic PS neurons were also glycinergic and 76% of glycinergic PS neurons were GABAergic. In conclusion, the rostral ventromedial medulla contains large numbers of GABAergic and glycinergic neurons that innervate adrenal gland SPGNs. Over half of these PS neurons may release both transmitters. The physiological role of this medullary inhibitory input remains to be explored. J. Comp. Neurol. 479:257–270, 2004. © 2004 Wiley-Liss, Inc.
Predictions of crack propagation using a variational multiscale approach and its application to fracture in laminated fiber reinforced composites

Abstract Predictions of crack propagation is a valuable resource for ensuring structural integrity and damage tolerance of aerospace structures. Towards that end, a variational multiscale approach to predict mixed mode in-plane cohesive crack propagation is presented here. To demonstrate applicability and to provide validation of the finite element based predictive methodology, a comparative study of the numerical results with the corresponding experimental observations of crack propagation in laminated fiber reinforced composite panels is presented.
Van Hove excitons and high-Tc superconductivity VIIIB. vHs - Jahn-Teller effect

Abstract This paper considers the structurak phase transitions of La 2− x Ba x CuO 4 in a detailed model describing the tilting of the O octahedra (optical modes), strains (acoustic modes), and electrons near the two saddle points ( X, Y ) of the Brillouin zone. The model contains nonlinear terms in the tilting part, strain-tilting coupling, and electron-tilting coupling, which is new and important in discussing the various phases. The variables are divided into static and dynamic parts, and their equations of motion are linearized to give self-consistent solutions for the optical phonon frequencies. The above model and procedure are extension of previous works for structural phase transitions in A15 and Perovskite-type compounds. But a relation between the structural phase transitions and the van Hove singularity is newly discussed. The model is found to be a natural generalization to two dimensions of the Peierls transition of a one-dimensional metal. The resulting equations are used to fit the temperature (and wave number) dependence of the optical phonon frequencies as measured by neutron and Raman scattering. It is concluded that phonon softening associated with the low-temperature orthorhombic (LTO) transition can be described equally well either by a pure phonon model with anharmonicity or by an electron-phonon model reflecting the van Hove singularity. It is suggested that the latter model is relevant in describing the doping dependence of the structure as well as superconducting and magnetic transitions. The results suggest that the LTO phase may be a dynamic Jahn-Teller (JT) phase, involving tunneling among local quasi-static JT distortions, with the low-temperature tetragonal phase being a static JT phase.
Hyperons at FERMILAB

Magnetic moment measurement of the baryon octet and decouplet have recently been measurements illustrated the success as well as the limitations of the simpple qazrk model. Measurements of hyperon production polarizations have shown this to be a rich and complex process. It has forced us to reconsider our basic understanding of hyperon polarization processes.
Will they stay?: turnover intentions of future federal cyber corps members

ABSTRACTAlthough significant research has been conducted on the turnover intentions of IT professionals once they are engaged in an employment relationship, not much is known about the ex-ante turnover intentions of future IT professionals. This is particularly true for the professional sub-population of cyber security workers. In this study we propose a model based on Agarwal et al. (2007) that examines the factors that influence turnover intentions of future IT professionals who have made the commitment to work for the federal government as members of the federal cyber corps. As Argawal et al. (2007) point out, although researchers are able to identify factors that drive turnover intentions once an individual is already engaged in an employment relationship, little is known about the ex-ante intentions of new IT workforce entrants. Our model takes affective commitment, public service motivation, role stressors (role ambiguity, role conflict), and preferred variety as antecedents of turnover intention.In addition to the contribution to the turnover intention literature, this study will add to the emerging body of knowledge on service corps programs. Given the increasing prominence of these programs (e.g. AmeriCorps) a thoughtful examination of the potential short- and long-term impact is warranted.We expect to present empirical results during the conference.
Crowding out Citizenship

The currently accepted theory of collective action presumes that individuals are helplessly trapped in social dilemmas. This has led to a form of policy analysis that presumes external authorities must solve all collective-action problems. The presumed universal need for externally implemented incentives is based, however, on a single model of rational behavior. This model has been shown to be an inadequate foundation to explain extensive empirical findings from the field and the experimental laboratory related to nonmarket settings. Thus, it is necessary to adopt a broader theory of human behavior that posits multiple types of individuals – including rational egoists as well as conditional cooperators – and examines how the contexts of collective action affect the mix of individuals involved. I will briefly review the empirical evidence related to intrinsic motivations and how external incentives may crowd out or crowd in behaviors that are based on intrinsic preferences. I then discuss the delicate problem of designing institutions that enhance citizenship rather than crowding it out. The penchant for neat, orderly hierarchical systems needs to be replaced with a recognition that complex, polycentric systems are needed to cope effectively with complex problems of modern life and to give all citizens a more effective role in the governance of democratic societies.