cssi/SciSciGPT-SciSciNet huggingface dataset:
Compensatory brainstem functional and structural connectivity in patients with degenerative cervical myelopathy by probabilistic tractography and functional MRI.

Degenerative cervical myelopathy (DCM) is the most common cause of spinal cord impairment in adults. Previous supraspinal investigations have primarily focused on cortical changes in this patient population. As the nexus between the brain and the spinal cord, the brainstem has been understudied in patients with DCM. The current study examined the structural and functional connectivity between the brainstem and cortex in DCM patients using probabilistic tractography and resting-state functional MRI. A total of 26 study patients and 32 neurologically intact, healthy volunteers (HCs) participated in this prospective analysis. The study cohort included DCM patients (n = 18), as well as neurologically asymptomatic patients with evidence of cervical spine degenerative changes and spinal cord compression (n = 8). Results of the study demonstrated significant differences in fiber density (FD), fiber cross-section (FDC), and the functional connectivity (FC) between the study cohort and HCs. Through seeding the brainstem, the study cohort showed reductions in FD and FDC along the corticospinal tract, including regions extending through the corona radiata and internal capsule. By correlating FD and FDC with the Neck Disability Index (NDI), and the modified Japanese Orthopaedic Association (mJOA), we identified increasing total volume of projections to the thalamus, basal ganglia, and internal capsule, and increased functional connectivity to visual network and the posterior parietal cortices. These results support our hypothesis that DCM patients tend to have long-term FC reorganization not only localized to sensorimotor regions, but also to regulatory and visual processing regions, designed to ultimately preserve neurological function.
Scleraxis-lineage cell depletion improves tendon healing and disrupts adult tendon homeostasis

Despite the requirement for Scleraxis-lineage (ScxLin) cells during tendon development, the function of ScxLin cells during adult tendon repair, post-natal growth, and adult homeostasis have not been defined. Therefore, we inducibly depleted ScxLin cells (ScxLinDTR) prior to tendon injury and repair surgery and hypothesized that ScxLinDTR mice would exhibit functionally deficient healing compared to wild-type littermates. Surprisingly, depletion of ScxLin cells resulted in increased biomechanical properties without impairments in gliding function at 28 days post-repair, indicative of regeneration. RNA sequencing of day 28 post-repair tendons highlighted differences in matrix-related genes, cell motility, cytoskeletal organization, and metabolism. We also utilized ScxLinDTR mice to define the effects on post-natal tendon growth and adult tendon homeostasis and discovered that adult ScxLin cell depletion resulted in altered tendon collagen fibril diameter, density, and dispersion. Collectively, these findings enhance our fundamental understanding of tendon cell localization, function, and fate during healing, growth, and homeostasis.
Characteristics and Outcome in Non-Puerperal Uterine Inversion.

Chronic non-puerperal uterine inversion is rare and usually associated with uterine pathology with a diagnosis that is challenging. We present the case of a 47-year-old para 4 Caucasian woman with a history of polyfibromatous uterus who was admitted for severe vaginal bleeding for the past 48 hours associated with hemodynamical instability and was refusing any surgery. Pelvic MRI showed the uterus presenting an unusual appearance with a highly vascularized intracavitary leiomyoma protruding through the cervix. Upon deterioration of her status despite an optimal blood transfusion, resuscitation and anti-fibrinolytic treatment, she accepted total abdominal hysterectomy. The diagnosis of uterine inversion was made intraoperatively and confirmed on histopathologic examination. It revealed two side-by-side benign fundal leiomyomas which had collapsed the fundus and protruded partly from the cervix. Non-puerperal chronic inversion of the uterus is rare, and its diagnosis should be based on ultrasound, pelvic MRI and a high index of suspicion, allowing rapid diagnosis and treatment and thus decreasing patient morbidity and mortality.
The impact of family physicians in rural maternity care.

Background Reduced access to maternity care in rural areas of the United States presents a significant burden to pregnant persons and infants. The objective of this study was to estimate the impact of family physicians (FPs) on access to maternity care in rural United States hospitals, especially where other providers may not be available. Methods We administered a survey to 216 rural hospitals in 10 US states inquiring about the number of babies delivered from 2013 to 2017, the types of delivering physicians, and the maternity services offered. We calculated the percentage of rural hospitals in our sample where FPs performed vaginal deliveries, cesareans, and vaginal births after cesarean (VBACs), and the percentage of all babies delivered by FPs. We estimated the distance patients would have to travel for care if FPs were not providing care locally. Results The final study population consisted of 185 rural hospitals. FPs delivered babies in 67% of these hospitals and were the only physicians who delivered babies in 27% of these hospitals. FPs provided VBAC at 18% and cesarean birth services at 46% of the rural hospitals, but with wide geographic differences. Many patients would have to drive an average of 86 miles round-trip to access care if those FPs were to stop delivering. Conclusions Family physicians are essential providers of maternity care in the rural United States. Family Medicine residency programs should ensure that trainees who intend to practice in rural locations have adequate maternity care training to maintain and expand access to maternity care for rural patients and their families.
Hypnotherapy for Esophageal Disorders

Hypnotherapy is an evidence based intervention for the treatment of functional bowel disorders, particularly irritable bowel syndrome. While similar in pathophysiology, less is known about the utility of hypnotherapy in the upper gastrointestinal tract. Esophageal disorders, most of which are functional in nature, cause painful and uncomfortable symptoms that impact patient quality of life and are difficult to treat from a medical perspective. After a thorough medical workup and a failed trial of proton pump inhibitor therapy, options for treatment are significantly limited. While the pathophysiology is likely multifactorial, two critical factors are believed to drive esophageal symptoms--visceral hypersensitivity and symptom hypervigilance. The goal of esophageal directed hypnotherapy is to promote a deep state of relaxation with focused attention allowing the patient to learn to modulate physiological sensations and symptoms that are not easily addressed with conventional medical intervention. Currently, the use of hypnosis is suitable for dysphagia, globus, functional chest pain/non-cardiac chest pain, dyspepsia, and functional heartburn. In this article the authors will provide a rationale for the use of hypnosis in these disorders, presenting the science whenever available, describing their approach with these patients, and sharing a case study representing a successful outcome.
Cytokeratin expression in normal human bulbar conjunctiva obtained by impression cytology.

Purpose To document the cytokeratin expression patterns in the normal human conjunctival epithelium obtained directly from patients using impression cytology. Methods Impression cytology specimens were obtained from normal volunteers using pure nitrocellulose membranes rather than cellulose acetate. The 31 volunteers of both sexes ranged in age from 18 to 79 years. Impression cytology specimens were analyzed for individual cytokeratins by either immunocytochemistry or electrophoresis with immunoblotting using a defined panel of monoclonal antibodies. Results Using the corroborative methods of immunocytochemistry and electrophoresis with immunoblotting, cytokeratins characteristic of nonkeratinized, stratified (K4 and K13), simple (K8 and K19), and glandular epithelia (K7) were present in the superficial layer (s) of normal human conjunctiva. Cytokeratins typical of keratinized epithelia (K1, K2, and K10) and the keratinization-related proteins filaggrin and involucrin were not expressed in normal conjunctival epithelium. Conclusions The normal human conjunctiva demonstrates a unique cytokeratin expression pattern containing cytokeratins characteristic of nonkeratinized, stratified epithelia, as well as others more typical of a simple differentiation pattern, a glandular differentiation pattern, or both. These findings provide a foundation for examining changes in the cytokeratin expression pattern in diseased human conjunctival epithelium using impression cytology.
Type Ia supernovae: observational overview

It is a pleasure to give the opening lecture of this NATO Advanced Study Institute on Thermonuclear Supernovae (SNe). I have been asked to provide a broad overview of the observations, primarily optical, as a preface to the many subsequent detailed presentations and as a guide for theorists.
A descriptive study of youth risk behavior in urban and rural secondary school students in El Salvador

Background Adolescence is an important stage of life for establishing healthy behaviors, attitudes, and lifestyles that contribute to current and future health. Health risk behavior is one indicator of health of young people that may serve both as a measure of health over time as well as a target for health policies and programs. This study examined the prevalence and distribution of youth health risk behaviors from five risk behavior domains–aggression, victimization, depression and suicidal ideation, substance use, and sexual behaviors–among public secondary school students in central El Salvador.
Phosphine‐Catalyzed [3 + 2] Annulation: Synthesis of Ethyl 5‐(tert‐Butyl)‐2‐Phenyl‐1‐Tosyl‐3‐Pyrroline‐3‐Carboxylate

Ethyl 5,5-dimethylhexa-2,3-dienoate Ethyl (triphenylphosphoranylidene)acetate 3,3-Dimethylbutyryl chloride Triethylamine Ethyl 5-(tert-butyl)-2-phenyl-1-tosyl-3-pyrroline-3-carboxylate (E)-N-Benzylidene-4-methylbenzenesulfonamide Tributylphosphine Keywords: phosphine-catalyzed [3 + 2] annulation; ethyl 5-(tert-butyl)-2-phenyl-1-tosyl-3-pyrroline-3- carboxylate; nucleophilic tertiary phosphines; geranylgeranyltransferase type-I (GGTase-1) inhibitors (GGTIs)
Effects of loaded breathing and hypoxia on diaphragm metabolism as measured by 31P-NMR spectroscopy

Diaphragm fatigue may contribute to respiratory failure.31P-nuclear magnetic resonance spectroscopy is a useful tool to assess energetic changes within the diaphragm during fatigue, as indicated by...
Inductive contamination analysis (ICA) with SRAM application

This paper proposes a new simulation-based fault modeling methodology. The methodology-an extension of Inductive Fault Analysis-uses the contamination-defect-fault simulator CODEF to directly relate effects of process-induced contamination to circuit-level malfunctions. The application of this methodology (called Inductive Contamination Analysis) is demonstrated by development of SRAM fault models.
‘The canary in the coalmine’: The nonaccommodation cycle in the gendered workplace

In this paper, we look at workplace communication nonaccommodation between men and women coworkers and its role in the persistence of organizational gender inequality. We contend that the principles of Communication Accommodation Theory (CAT) explain the dynamics of intergroup psychological processes underlying gender-based workplace communication breakdowns, which contribute to the development and maintenance of separate gender group workplace social identities. Drawing upon prior research and theory, especially Coupland, Wiemann & Giles’(1991) miscommunication model and Dube-Simard's model of intergroup communication breakdown, we develop a model of the workplace gender nonaccommodation cycle and its effects upon men's and women's workplace linguistic practices. We also suggest that recognition of the intergroup nature of gender-based workplace conflicts can point the way to finding solutions that reduce the incidence of these communication breakdowns or, at the least, mitigate their worst effects.
Estimation of cancer risks and benefits associated with a potential increased consumption of fruits and vegetables

The current paper provides an analysis of the potential number of cancer cases that might be prevented if half the U.S. population increased its fruit and vegetable consumption by one serving each per day. This number is contrasted with an upper-bound estimate of concomitant cancer cases that might be theoretically attributed to the intake of pesticide residues arising from the same additional fruit and vegetable consumption. The cancer prevention estimates were derived using a published meta-analysis of nutritional epidemiology studies. The cancer risks were estimated using U.S. Environmental Protection Agency (EPA) methods, cancer potency estimates from rodent bioassays, and pesticide residue sampling data from the U.S. Department of Agriculture (USDA). The resulting estimates are that approximately 20,000 cancer cases per year could be prevented by increasing fruit and vegetable consumption, while up to 10 cancer cases per year could be caused by the added pesticide consumption. These estimates have significant uncertainties (e.g., potential residual confounding in the fruit and vegetable epidemiologic studies and reliance on rodent bioassays for cancer risk). However, the overwhelming difference between benefit and risk estimates provides confidence that consumers should not be concerned about cancer risks from consuming conventionally-grown fruits and vegetables.
Single-node cuttings as a new method of mint propagation

Abstract Single-node cuttings of stem tissue, green stolons and etiolated rhizomes were used to propagate several Mentha species ( M. piperita L., M. spicata Hunds., M. rotundifolia L. and M. rotundifolia var. variegata ) under controlled conditions. Rooting percentage was maximal for etiolated rhizomes and decreased in order for green stolons, sprouted mid-stem, basal and apical cuttings. Rooting of stem tissue was dramatically increased for all species by pre-treatment of cuttings with indole-3-butyric acid and α-naphthylacetic acid. No significant differences were observed between the different Mentha species with regard to rooting percentage, length of resulting roots or fresh weight of developing tissue. However, both root length and fresh weight were also highly dependent on the type of cutting, with etiolated rhizomes providing maximum values and the lower values of stem cuttings decreasing in the order: sprouted mid-stem → basal → apical.
An atomistic study of the abrasive wear and failure of graphene sheets when used as a solid lubricant and a comparison to diamond-like-carbon coatings

Abstract The failure mechanisms of graphene under nanoscale sliding conditions are examined using atomistic simulations to evaluate its use as a solid lubricant and to simultaneously answer principal questions regarding wear of lamellar films comprised of atomically-thin sheets. To determine the failure behavior of graphene and the impact of adhesion on wear and failure, an asperity is slid over a substrate-supported graphene film with various adhesion strengths. For a purely-repulsive asperity, the graphene never delaminates and lower substrate-membrane adhesion appears to reduce the overall damage to the graphene layer and permits the recovery of more of the load-bearing capability of the graphene post-tearing. When tri-layer graphene is benchmarked with a 2 nm repulsive asperity against an 86% sp3 content diamond-like-carbon (DLC) coating of the same thickness (1.0 nm), the graphene supports up to 8.5 times the normal load of DLC during indentation, and up to twice the normal load of DLC during sliding even after failure of one or more layers. The preliminary results indicate that graphene has promise as a solid lubricant with thickness on the order of nanometers due to its atomically-thin configuration and high load carrying capacity.
From damnation to redemption: Judgments on the late victorian entrepreneur☆

In the 1890’s it became clear that Britain had lost the industrial leadership of the world to Germany and the United States. Each year the statistics of trade and output brought fresh evidence that the trend established in the 1870’s of slower industrial growth in Britain than in the new industrial nations was continuing. New products and new markets were being developed by German chemists and salesmen and by American engineers and plant managers while British businessmen fought a rearguard action on economic battlefields where they had once stood unchallenged. Such military metaphors as this last flowed naturally from the pens of journalists and scholars describing this humbling experience, and there was much talk of commercial “invasion” and industrial “defeat.” Anthropomorphic metaphors, as well, of “youthful” foreign nations usurping the place of “old” Britain, were called on to bolster the frail illusion of understanding the turn of events. And when metaphor proved unsatisfying, it was natural that attention should turn to the men at the top. When an army is outmaneuvered, who is to blame for its defeat but its incompetent generals? When an economy grows old, who is to blame for its decrepitude but its aging businessmen? increasingly after the 1890’s in the editorial columns of trade journals and in the pages of government reports, for one industry after another, blame for the British lag behind Germany and America was put on British management. On the level of journalism and schoolbook history there is no difficulty in meting out praise or blame: if great entrepreneurs, independent 01 circumstances, were responsible for Britain’s relative rise before 18 70, then surely bad entrepreneurs must have been responsible for her relative decline after 1870. The reasoning involved is the same as that underlying the
The premelting of ice and its environmental consequences

Several mechanisms can extend the equilibrium domain of a liquid phase into the solid region of the normal phase diagram. The causes of premelting, which include surface melting, interface curvature and substrate disorder, occur in all types of substances, including H2O. In the case of H2O, premelting can have important environmental consequences, among which are the heaving of frozen ground, breakdown of rock and concrete, sintering of snow, flow of glaciers, scavenging of atmospheric trace gases by snow and ice, and the electrification of thunderclouds. The article reviews the basic mechanisms of premelting and discusses their roles in the environmental phenomena. The principal results of numerous studies are reviewed, and trends in current research are outlined.
The effect of L1 use on pronunciation in Quichua–Spanish bilinguals

Abstract This study investigated the interaction of the L1 and L2 systems in bilinguals by assessing the effect of L1 use on L1 and L2 production accuracy. A novel design feature of this study is that it examined bilinguals who used their L1 on a regular basis in a bilingual setting: Otavalo, Ecuador. Thirty native Quichua speakers who were matched for age of Spanish acquisition were recruited to form three groups differing in self-reported L1 use. The three groups repeated aurally presented sentences from their L1 and L2. Monolingual listeners from each language rated the blocked, randomly presented sentences for degree of foreign accent. For the Spanish sentences, the group with the highest L1 use had stronger Quichua accents than the group with the lowest L1 use. On the other hand, L1 use had no effect on the ratings of the Quichua sentences. Results from an analysis of Korean–English bilinguals are also reported. These results replicate the finding that L1 use affects L2, but not L1 production. These findings indicate that the interaction of the L1 and L2 systems affects the success of L2 acquisition, providing evidence that factors other than neurological maturation influence L2 acquisition.
Ab initio studies of structural features not easily amenable to experiment. 25. Conformational analysis of methyl propanoate and comparison with the methyl ester of glycine

The molecular geometries of three conformations of methyl propanoate (MEP) (CCCO torsions of 0°, 120°, and 180°) and the potential-energy surfaces of MEP (CCCO torsions) and of the methyl ester of glycine (MEG) (NCCO torsions) have been determined by ab initio gradient calculations at the 4-21G level. MEP has conformational energy minima at 0° and 120° of the CCCO torsion, while the 60–90° range and 180° are energy maxima. For MEG there are two minima (at 0° and 180°) and one barrier to NCCO rotation in the 60–90° range. The NCCO barrier height is about twice as high (4 kcal/mol) as the CCCO barrier. The 180° NCCO minimum is characteristically wide and flat allowing for considerable flexibility of the NCCO torsion in the 150–210° range. This flexibility could be of potential importance for polypeptide systems, since the NCCO angles of helical forms are usually found in this region. The molecular structures of the methyl ester group CH3OC(O)CHRR′ in several systems are compared and found to be rather constant when R H and R′ H, CH3, CH3CH2; or when R NH2 and R′ H, CH3, or CH(CH3)2.
Rapid virulence test in diagnosis of diphtheria.

SummaryThe mixed growth from 266 original Loeffler slants submitted for diagnosis of suspected diphtheria was streaked directly onto tellurite-agar plates prepared for the in vitro toxigenicity test (I.V.T.T.). Of 196 such diagnostic specimens later shown, by pure culture isolations and animal tests, to contain virulent C. diphtheriae, 130 (66.3%) yielded positive results; 63 (48%) in 24 hours, 53 (40%) in 48 hours and 14 (11%) in 72 hours. Nine of the original 266 cultures were later shown by pure culture isolations and animal tests to contain non-toxigenic C. diphtheriae. These yielded negative I.V.T.T. Preliminary tests with prepared swabs indicate that positive I.V.T.T. frequently may be obtained directly from them in 24 hours. The I.V.T.T. plate, with K Te, offers a rapid and simple method of detecting virulent C. diphtheriae in a useful percentage of original diagnostic specimens.
The role of HOX genes in the development and function of the female reproductive tract.

HOX genes are a family of regulatory genes that encode transcription factors and are essential during embryonic development. These genes are highly conserved between species such that all metazoans possess a common genetic system for embryonic patterning. This system is conserved in the reproductive tract, where HOX genes are involved in the development of the mullerian system. The reproductive tract is unusual in that HOX genes continue to be expressed in the adult. HOX genes are essential both for appropriate reproductive tract development and for adult function. This article reviews the role of HOX genes in the development of the reproductive tract and the effect of HOX gene mutations on the development of the reproductive tract in both mice and humans. It then reviews the role and regulation of HOX genes in the adult function of the reproductive tract, specifically evidence that HOX genes are important for human endometrial development and receptivity.
Left atrial volumetric remodeling is predictive of functional capacity in nonobstructive hypertrophic cardiomyopathy.

Background The left atrium is afterload sensitive, responding to immediate changes in left ventricular (LV) diastolic pressure, and left atrial volumetric remodeling has been reported in conditions associated with abnormal diastolic function. We examined the relationship between left atrial volumetric remodeling and objective measures of exercise capacity in patients with nonobstructive hypertrophic cardiomyopathy (HCM). Methods We compared LA volume indices, other 2-dimensional and Doppler echocardiographic parameters, invasive hemodynamic measures, and magnetic resonance imaging (MRI)–derived LV mass with exercise duration, maximal oxygen uptake (MV˙o 2 ), anaerobic threshold (AT), and ventilatory efficiency (VE/V˙co 2 slope) in 43 patients with nonobstructive HCM. Patients underwent cardiac catheterization within 48 hours and metabolic stress testing within 1 week of their echocardiogram and MRI examinations. Results Left atrial volume at end-ventricular systole (LA max ) and end-atrial emptying (LA min ) correlated with MV˙o 2 ( r = −0.39, P r = −0.42, r = −0.39, respectively, P 2 slope ( r = 0.45, P = .003; r = 0.41, P = .008). Patients with an LA max ≥33 mL/m 2 had significantly lower MV˙o 2 ( P = .025) and AT levels ( P = .017) and higher VE/V˙co 2 slope levels ( P = .004) as compared with patients with a smaller LA size. In multivariate analysis, MRI-determined LV mass, which was not a univariate correlate of exercise tolerance, provided additional effect when combined with LA volume index. Conclusions Left atrial volumetric remodeling predicts exercise capacity in nonobstructive HCM and may reflect chronic LV diastolic burden. This simple noninvasive measure of LA size may provide a long-term indication of the effects of chronically elevated filling pressures in patients with HCM and further studies testing its prognostic value are necessary.
A Thermodynamically Based and Definitive Demonstration of the Inadequacy of the ECW Model for Phosphorus(III) Ligands

Isoequilibrium behavior arising from the temperature dependence of ΔG° of families of complexes containing phosphorus(III) ligands provides a diagnostic method for evaluating a model (used to describe ligand effects) and the associated set of stereoelectronic parameters. This evaluation is based not on the quality of a linear free energy relationship, but rather on the results of a thermodynamic argument. Studies of the temperature dependence of E°/T values for the η-Cp(CO)(L)Fe(COMe)+/η-Cp(CO)(L)Fe(COMe)0 couple, where L is a phosphorus(III) ligand, provide isoequilibrium data to test the ECW model for analysis of ligand effects. The ECW model fails this test. Therefore, we conclude that the ECW model is, in general, inadequate to describe the stereoelectronic properties of phosphorus(III) ligands.
On the design of command and stability augmentation systems for advanced technology aeroplanes

There exists an enormous wealth of published material describing the application of so called, 'modern control methods' to the design of fliglat control systems for piloted aeroplanes. It is also evident, with the exception of a very small number of recent applications, that there is a conspicuous lack of enthusiasm on the part of the airframe manufacturers to adopt this design technology, especially for the design of command and stability augmentation systems for piloted aeroplanes. It is possible to speculate on the reasons for this apparent lack of interest, but to do so might well result in a misplaced condemnation of modern control methods. Since evidence exists to suggest that some modern control system design strategies have overlooked important flight dynamics considerations, the discussion is turned around here by drawing attention to some of the more important considerations in command and stability augmentation system design. The object is, therefore, to inform the designer, of whatever persuas...
Poincaré and gauge invariances in the constituent-string model

Abstract The constituent-string model developed in earlier work provides an alternative to the usual description of asymptotic states as direct products of single-particle states, and may be more appropriate for the strong interactions. Here, the simple but nonlinear N-body harmonic-oscillator Lagrangian is modified to include gauge symmetries in analogy to electrodynamics. Gauge conditions then lead to a set of “orthonormal” conditions equivalent to the invariant supplementary conditions used in earlier work to suppress time oscillations.
The characterization of Mode I delamination failure in non-woven, multidirectional laminates

The uniform double cantilever beam test and SEM are presently used for the characterization of Mode I delamination behavior in fiber-reinforced epoxy laminates. Delamination failure assumes forms that depend on ply orientation, test specimen geometry, and matrix toughness, but the calculated fracture energy is noted to be heavily dependent on fracture surface morphology. A material property concept that is independent of both test specimen geometry and the orientation of the plies constituting the delaminating interface is elucidated, through the definition of interlaminar fracture solely in terms of an interlaminar separation that includes no fiber breakage or pull-out. This value, which dissipates the lowest possible amount of energy during crack growth, is the controlling factor for laminate toughness.
The dynamics of nitric acid production and the fate of nitrogen oxides

A mathematical model is used to study the fate of nitrogen oxides (NO_x) emissions and the reactions responsible for the formation of nitric acid (HNO_3). Model results indicate that the majority of the NO_x inserted into an air parcel in the Los Angeles basin is removed by dry deposition at the ground during the first 24 h of travel, and that HNO_3 is the largest single contributor to this deposition flux. A significant amount of the nitric acid is produced at night by N_2O_5 hydrolysis. Perturbation of the N_2O_5 hydrolysis rate constant within the chemical mechanism results in redistribution of the pathway by which HNO_3 is formed, but does not greatly affect the total amount of HNO_3 produced. Inclusion of NO_3-aerosol and N_2O_5-aerosol reactions does not affect the system greatly at collision efficiencies, α, of 0.001, but at α = 0.1 or α = 1.0, a great deal of nitric acid could be produced by heterogeneous chemical processes. Ability to account for the observed nitrate radical (NO_3) concentrations in the atmosphere provides a key test of the air quality modeling procedure. Predicted NO_3 concentrations compare well with those measured by Platt et al. (Geophys. Res. Lett.7, 89–92, 1980). Analysis shows that transport, deposition and emissions, as well as chemistry, are important in explaining the behavior of NO_3 in the atmosphere.
Generation of clonal zebrafish lines and transplantable hepatic tumors

Transplantable tumors are an accepted gold standard in cancer studies in rodents. The progress of this model in zebrafish has long been constrained by the lack of true inbred lines in zebrafish. We have generated several lines of homozygous diploid clonal zebrafish lines, which allow serial transplantations of tumor cells from one fish to another without sublethal gamma-irradiation. The spectrum of transplantable tumors that were initially induced and maintained in inbred clonal zebrafish lines was limited to different types of spontaneous and diethylnitrosamine-induced hepatic tumors. However, this model can readily be extended to a broad range of extrahepatic tumors, transgenic tumors with defined mechanisms of induction and fluorescence-tagged tumor lines. These models will further facilitate in-depth analysis of invasive tumor growth, angiogenesis, metastasis and tumor-initiating cells by in vivo imaging and provide a cost-effective system for high-throughput (HTP) screening of anticancer therapeutics, including biological response modifiers. In addition, homozygous zebrafish lines are an indispensable tool for immunogenetics, mapping of quantitative trait loci and other genetic applications. The whole procedure, from generation of a gynogenetic female homozygous fish (a founder) to obtaining 3-4 consecutive passages of a syngeneic tumor, takes approximately 12-18 months. This time-frame largely depends on methods of tumor induction, tumor type and tumor growth rate.
The effects of retinoic acid on immunoglobulin synthesis by human cord blood mononuclear cells

Derivatives of vitamin A have attracted considerable attention as agents which have immune potentiating properties and possibly tumor-suppressive effects. Recent investigations have shown that retinoic acid (RA) can augment immunoglobulin production of B-cell hybridomas from patients with immune deficiency. In this study we examined the ability of RA to modify the mitogen-induced polyclonal immunoglobulin synthesis of cord blood mononuclear cells (CBMC). RA in concentrations ranging from 10(-5) to 10(-7) M augmented IgM synthesis of CBMC in response to formalinized Cowans I strain Staphylococcus aureus (SAC) up to 45.6-fold which was greater at suboptimal responses to SAC. There were no changes in IgG or IgA synthesis and minimal effects on SAC-induced proliferative responses. RA did not produce similar changes in IgM synthesis of SAC-stimulated adult peripheral blood mononuclear cells (PBMC), and RA had no effect on the immunoglobulin synthesis of Epstein-Barr virus (EBV)-stimulated CBMC or adult PBMC. Time course studies showed that peak enhancement occurred when RA was added between 4 and 24 hr after culture initiation and required prior activation by SAC for augmentation of IgM synthesis. Cell separation experiments showed that prior incubation (18 hr) of an enriched T-cell fraction with RA enhanced the IgM synthesis of a T-cell-depleted B-cell fraction. These experiments and the findings that RA-induced augmentation of IgM production in response to SAC, but not to EBV suggest that the immunoregulatory effects of RA may be mediated by either T cells or T-cell products. Further studies will be necessary to understand the mechanism by which RA augments IgM synthesis of CBMC.
Downscale linkage of global model output for regional chemical transport modeling: Method and general performance

[1] The goal of this study is to assess the impact of the downscale linkage of global chemistry model output on the simulated regional scale O3 concentration and its vertical and horizontal structure over the continental US. For the global chemistry model, the NASA LaRC-University of Wisconsin Real-time Air Quality Modeling System (RAQMS) with a global ozone assimilation framework was used. RAQMS simulation results were downscaled with a RAQMS-CMAQ linkage tool (RAQ2CMAQ) to provide dynamic lateral boundary conditions for regional air quality simulations with the EPA Models-3 Community Multiscale Air Quality (CMAQ) Model. We performed two sets of CMAQ simulations; (1) with the predefined lateral boundary condition profile representing relatively clean air conditions in the eastern-half of the United States, and (2) with the lateral boundary conditions generated from RAQMS 6 hourly analyses, for the 1999 Southern Oxidant Study (SOS-99) period (15 June–14 July 1999). When compared and evaluated with available ozone soundings and nation wide surface observations (AIRS/EPA) in U.S., CMAQ simulations with the lateral boundary condition from the predefined profile failed to simulate the so-called “chemical tropopause” above which O3 concentration rapidly increases with height. On the other hand, the simulations with the lateral boundary condition provided with the global RAQMS output not only improved diurnal variations and daily maxima of surface O3 concentrations, but also produced better agreement with the vertical structure of O3 measured in the middle and upper troposphere. The tracer mode CMAQ simulations showed that, at the upper troposphere, more than 85% of the O3 concentration difference associated with the lateral BCs was caused by the transport and diffusion processes.
General covariance and harmonic maps

Abstract The principle of general covariance is used to derive the conditions for a map to be harmonic. Modification to the harmonic map equations due to the presence of a Yang–Mills field is described.
Differential response of ducks and chicks to dietary sorghum tannins

White Pekin ducklings were reared in floor pens and given access to nipple-type waterers in order to eliminate a feeding behaviour previously observed in battery brooder-raised ducks in which sorghum tannins were possibly detoxicated by exposure of the ground grain to water. High-tannin sorghum (HTS)—soya bean meal and low-tannin sorghum (LTS)—soya bean meal diets, suboptimal in protein, with or without supplemental methionine, and either in dry mash or pellet form, were fed to both day-old ducks and chicks for either 14 or 17 days, respectively. The chicks were reared in battery brooders. In contrast to previous findings with ducks raised in battery brooders, HTS-fed ducks reared in floor pens exhibited reduced weight gain and feed efficiency values compared with LTS-fed ducks. However, the magnitude of the growth depression caused by feeding ducks HTS versus LTS was much less than that observed in chicks fed the identical diets (17 versus 33%, respectively). Methionine supplementation of the HTS diets completely overcame the reduced weight gain in ducks, but feed efficiency values were still significantly poorer than those of ducks fed methionine-supplemented LTS diets. In contrast, although HTS-fed chicks responded to dietary methionine supplementation, they still exhibited poorer weight gain and feed eficiency values compared with birds fed LTS diets similarly supplemneted. Increasing the dietary level of supplemental methionine did not result in any further improvement in performance of chicks fed either LTS- or HTS-based diets. It was concluded that, compared with chicken, ducks are less affected by dietary sorghum tannins.
Behavioral and reproductive responses of female opossums to volatile and nonvolatile components of male suprasternal gland secretion

Abstract Female gray short-tailed opossums ( Monodelphis domestica ) lack an estrous cycle and are induced into estrus by exposure to a pheromone in male scent marks. Behavioral and physiological responses of females to the volatile and nonvolatile components of scent marks were examined in two experiments. Young females ( n = 9) were tested prior to and during their first estrus for behavioral responses to scent marks, collected on a 7-ml glass vial rubbed over the suprasternal gland of a mature male. The response to volatile components of the scent mark, recorded when marked and unmarked vials were covered with a perforated shield, was compared to the response to these vials when unshielded. Estrous females nuzzled the shields over marked vials (55.8 ± 8.5 nuzzles/10 min) more than the shielded clean vial (10.9 ± 2.4) ( P P n = 11) exposed for up to 14 days to a shielded, marked vial or to an unshielded, marked vial in a crossover design. All females exposed to unshielded vials expressed estrus, and 10 copulated. Only 2 females expressed estrus (significantly fewer, P
Discovery of beta-delayed two-proton radioactivity: /sup 22/Al

A proton-proton coincidence experiment has shown that, following the superallowed beta decay of the odd-odd, ${T}_{z}=\ensuremath{-}2$ nuclide, $^{22}\mathrm{Al}$, two protons are emitted with a summed energy spectrum (5.636, 4.139 MeV) characteristic of decay to the ground and first excited states of $^{20}\mathrm{Ne}$, respectively.
The cinnamon-derived Michael acceptor cinnamic aldehyde impairs melanoma cell proliferation, invasiveness, and tumor growth

Redox dysregulation in cancer cells represents a chemical vulnerability that can be targeted by pro-oxidant redox intervention. Dietary constituents that contain an electrophilic Michael acceptor pharmacophore may therefore display promising chemopreventive and chemotherapeutic anti-cancer activity. Here, we demonstrate that the cinnamon-derived dietary Michael acceptor trans-cinnamic aldehyde (CA) impairs melanoma cell proliferation and tumor growth. Feasibility of therapeutic intervention using high doses of CA (120 mg/kg, po, daily, 10 days) was demonstrated in a human A375 melanoma SCID mouse xenograft model. Low-micromolar concentrations (IC(50)< 10 microM) of CA, but not closely related CA derivatives devoid of Michael acceptor activity, suppressed proliferation of human metastatic melanoma cell lines (A375, G361, LOX) with G1 cell-cycle arrest, elevated intracellular ROS, and impaired invasiveness. Expression array analysis revealed that CA induced an oxidative stress response in A375 cells, up-regulating heme oxygenase 1, sulfiredoxin 1 homolog, thioredoxin reductase 1, and other genes, including the cell-cycle regulator and stress-responsive tumor suppressor gene cyclin-dependent kinase inhibitor 1A, a key mediator of G1-phase arrest. CA, but not Michael-inactive derivatives, inhibited NF-kappaB transcriptional activity and TNFalpha-induced IL-8 production in A375 cells. These findings support a previously unrecognized role of CA as a dietary Michael acceptor with potential anti-cancer activity.
2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) inhibits growth factor withdrawal-induced apoptosis in the human mammary epithelial cell line, MCF-10A

Previous studies have demonstrated that 2,3,7, 8-tetrachlorodibenzo-p-dioxin (TCDD) increases cell recovery in the human mammary epithelial cell line MCF-10A grown under growth factor-restricted conditions. TCDD was also found to mimic growth factor signaling pathways by stimulating the tyrosine phosphorylation of numerous effector molecules, and increased phosphatidylinositol 3-kinase (PI3K) activity in the absence of exogenously added growth factors. In the present studies, we have expanded on these initial results to show that TCDD (3-30 nM) increases cell recovery on days 2-6 by as much as 80% when insulin or epidermal growth factor (EGF) was removed from the media. The mechanism for this effect appears to be complex as TCDD inhibited apoptosis stimulated by EGF, or EGF and insulin, withdrawal by almost 80% as determined by Annexin V binding. However, withdrawal of insulin alone did not induce apoptosis even though TCDD did increase cell number in its absence. These results were corroborated by immunoblot analysis of poly(ADP-ribose) polymerase cleavage. Since TCDD stimulates PI3K activity, the phosphorylation status of Akt, a serine/threonine kinase that mediates PI3K-dependent inhibition of apoptosis, was examined. Immunoblot analysis revealed that TCDD causes a transient increase in the phosphorylated form of Akt that peaks at 6 h and disappears by 12 h. It appears that EGF stimulates an anti-apoptotic pathway, while insulin signals a pro-mitogenic pathway. By stimulating or mimicking one or both of these pathways TCDD may alter tightly regulated growth pathways in the MCF-10A cell line.
Water Quality in Walnut Creek Watershed: Nitrate-Nitrogen in Soils, Subsurface Drainage Water, and Shallow Groundwater

Nonpoint source contamination of surface and groundwater resources with nitrate-N (NO 3 -N) has been linked to agriculture across the midwestern USA. A 4-yr study was conducted to assess the extent of NO 3 -N leaching in a central Iowa field. Water flow rate was monitored continuously and data were stored on an internal datalogger. Water samples for chemical analysis were collected weekly provided there was sufficient flow. Twelve soil cores were collected in spring, early summer, mid-summer, and after harvest for each of the 4 yr. Nitrate-N concentrations in shallow groundwater exhibited temporal trends and were higher under Clarion soil than under Okoboji or Canisteo soil. Denitrification rates were two times higher in Okoboji surface soil than in Clarion surface soil and the highest denitrification potential among subsurface sediments was observed for deep unoxidized loess. Soil profile NO 3 -N concentrations decreased with depth and were the same below 30 cm for fertilized corn (Zea mays L.) and soybean (Glycine max L. Merr.). Nitrate-N concentrations in subsurface drainage water exceeded 10 mg L -1 for 12 mo and were between 6 and 9 mg L -1 for 32 mo during the 4-yr study. The temporal pattern of NO 3 -N concentrations in subsurface drainage water was not related to the timing of fertilizer N application or the amount of fertilizer N applied. Total NO 3 -N losses to subsurface drains were greatest in 1993 (51.3 kg ha 1 ) and least in 1994 (4.9 kg ha -1 ). Most of the subsurface drainage water NO 3 -N was lost when crop plants were not present (November-May), except in 1993. Our results indicate that NO 3 -N losses to subsurface drainage water occur primarily as a result of asynchronous production and uptake of NO 3 -N in the soil and the presence of large quantities of potentially mineralizable N in the soil organic matter.
Babesia bigemina: Host Factors Affecting the Invasion of Erythrocytes

Babesia bigemina merozoites enter their host's erythrocytes by an unknown mechanism that likely involves parasite surface components. Identification of the parasite ligands involved in invasion is hampered by a lack of basic information about the invasion characteristics of Babesia bigemina. Therefore, restrictions on the species of red blood cells (RBC) that are susceptible to invasion were examined as well as the roles of erythrocyte ligands. An invasion assay and a proliferation assay were developed for this study. Unlike some other species of Babesia that infect cattle, B. bigemina failed to enter RBC from most animals that are not natural hosts, suggesting that a species restricted receptor mechanism mediates invasion. Two carbohydrates which are prominent on the surface of bovine erythrocytes, N-acetylglucosamine and N-acetylgalactosamine, when added to cultures, reduced the ability of B. bigemina merozoites to invade erythrocytes. Neuraminidase or trypsin treatment of bovine erythrocytes significantly decreased their susceptibility to invasion whereas chymotrypsin had little effect. These data imply that proteinaceous erythrocyte ligands and carbohydrate residues may be involved in the invasion process. Identification of a species-specific pattern of invasion and RBC treatments that render cells refractory to invasion may provide the basis for the characterization of B. bigemina erythrocyte binding molecules based on their differential binding to invasion competent and refractory cells.
Further investigations on colonization of Poncirus trifoliata by the Asian citrus psyllid

The Asian citrus psyllid (ACP), Diaphorina citri Kuwayama (Hemiptera: Liviidae) vectors a bacterium, ‘Candidatus Liberibacter asiaticus’ (CLas), associated with one of the world's most serious diseases of citrus, huanglongbing (HLB) (also known as citrus greening disease). There is no known cure for this disease, which severely reduces tree productivity and fruit quality and promotes tree decline and death. Most growers apply insecticides to control ACP as a tactic to prevent or reduce the incidence of HLB. Plant resistance to ACP may be a viable tactic for managing ACP and CLas. Resistance to colonization by ACP populations has been reported in the genotype Poncirus trifoliata L., which is cross compatible with citrus. The Citrus Research Center (CRC) in Riverside, California, maintains a large number of accessions of P. trifoliata. We conducted four free-choice experiments with 29 CRC accessions of P. trifoliata and found that ACP deposited fewer eggs on 19 of those accessions compared with susceptible sweet orange, Citrus sinensis (L.) Osbeck. Subsequent infestation densities of nymphs generally reflected reductions in oviposition but there were notable exceptions. Some accessions may be susceptible to oviposition but contain traits that confer antibiosis to nymphs. In no-choice experiments with seedling plants representing eight P. trifoliata accessions, oviposition rates were reduced compared with sweet orange and it appeared that factors associated with mature leaves were involved. In no-choice experiments with adult ACP confined to flush cuttings, large reductions were observed in the number of eggs and nymphs on each of five P. trifoliata accessions compared with sweet orange. Based on these results in conjunction with published reports, accessions were identified that consistently showed resistance to oviposition. However, the level of resistance in these accessions has been variable possibly due to environmental conditions, plant age, proximity of plants to susceptible germplasm, and other factors. Published by Elsevier Ltd.