cssi/SciSciGPT-SciSciNet huggingface dataset:
Light saturation response of inactive photosystem II reaction centers in spinach.

The effective absorption cross section of inactive photosystem II (PS II) centers, which is the product of the effective antenna size and the quantum yield for photochemistry, was investigated by comparing the light saturation curves of inactive PS II and active reaction centers in intact chloroplasts and thylakoid membranes of spinach (Spinacia oleracea). Inactive PS II centers are defined as the impaired PS II reaction centers that require greater than 50 ms for the reoxidation of QA− subsequent to a single turnover flash. Active reaction centers are defined as the rapidly turning over PS II centers (recovery time less than 50 ms) and all of the PS I centers. The electrochromic shift, measured by the flash-induced absorbance increase at 518 nm, was used to probe the activity of the reaction centers. Light saturation curves were generated for inactive PS II centers and active reaction centers by measuring the extent of the absorbance increase at 518 nm induced by red actinic flashes of variable energy. The light saturation curves show that inactive PS II centers required over twice as many photons as active reaction centers to achieve the same yield. The ratio of the flash energy required for 50% saturation for active reaction centers (PS II active + PS I) compared to inactive PS II centers was 0.45±0.04 in intact chloroplasts, and 0.54±0.11 in thylakoid membranes. Analysis of the light saturation curves using a Poisson statistical model in which the ratio of the antenna size of active PS II centers to that of PS I is considered to range from 1 to 1.5, indicates that the effective absorption cross section of inactive PS II centers was 0.54–0.37 times that of active PS II centers. If the quantum yield for photochemistry is assumed to be one, we estimate that the antenna system serving the inactive PS II centers contains approx. 110 chlorophyll molecules.
Three-dimensional cell cycle model with distributed transcription and translation

A computational cell cycle model that can describe three state properties, cell maturation age, specific mRNA and protein content, has been developed. Cell cycle propression is monitored by maturation age, and population heterogeneity is generated by the introduction of a probable random event embedded in the G1 phase. Specific mRNA is generated with a constant transcription rate at the single-cell level, and its turnover is governed by a first-order decay. Translation is modelled as a first-order dependence on the transcripts, and the protein product is subsequently exported. Dynamic chemostat simulations are used to demonstrate the ability of the model to track evolving parent and daughter subpopulations in maturation and cellular contents. The cell subpopulations eventually converge to an equilibrium distribution corresponding to the steady state of a chemostat, and halving of cellular content at cell division is the dominant driving force leading towards the population equilibrium state.
Infrequent reward facilitates observing responses in rats

Rats had the option of pressing either of two stimulus levers to gain access to a third lever which produced food reinforcement on 20%, 50%, or 80% of the trials for different groups. One stimulus lever led to stimuli correlated with reward and no reward; the other lever always led to the same stimulus. Delay of reward facilitated choice of the correlated stimuli, while increasing deprivation time had equivocal effects. Ss rewarded on 20% and 50% of the trials increased their frequency of choice of the correlated stimuli, while the 80% group showed a decrease with respect to baseline responding.
Kinetics of the Alfin polymerization of styrene and isoprene

The overall rate of polymerization of styrene and isoprene with the heterogeneous allylsodium–sodium isopropoxide–sodium chloride (Alfin PP) system as initiator is reaction-controlled and is first order with respect to monomer and proportional to the amount of initiator present. The intrinsic viscosity of the product is independent of the monomer and initiator concentrations. The rate of styrene polymerization is independent of alkoxide concentration over a certain range, while the intrinsic viscosity increases with increasing alkoxide concentration. The activation energy of the overall rate is about 12 kcal./mole for styrene and 10 kcal./mole for isoprene. The simplest explanation of the kinetic results assumes initiation and termination steps involving the monomer. The distribution of molecular weights in Alfin polystyrene appears very broad. The kinetic features of this reaction bear a strong resemblance to those of the formation of isotactic polymers from the alkyl aluminum–titanium chloride system (Ziegler catalyst.)
Submucosal Collagen in Experimental Gastroschisis

Gastroschisis is a congenital anomaly in which the intestines are exposed to amniotic fluid throughout fetal life. Previous studies in animal models have demonstrated smooth muscle thickening and decreased contractility, epithelial dysfunction, and submucosal thickening. The present studies were done to further define the mechanism of submucosal changes by investigating collagen deposition and gene expression in a rabbit model. Gastroschisis was surgically created in fetal rabbits at 24 days gestation (term is 31 days). Sham-operated and unoperated fetuses served as controls. Fetuses were sacrificed and bowels were harvested at 26, 28, and 31 days gestation. Animal weight and gross and histologic appearance were assessed. Submucosal collagen content was measured using the van Geison stain. In situ hybridization of the expression of alpha (1) procollagen RNA was done to determine the distribution and source of submucosal collagen. At term, submucosal thickening was present in animals with gastroschisis, associated with a significantly increased collagen content. Collagen distribution was also more diffuse in the gastroschisis animals than in controls. In situ hybridization revealed procollagen expression in round cells located in the submucosa and not in smooth muscle. These cells did not resemble fibroblasts, and their identity is uncertain. Experimental gastroschisis is characterized by submucosal thickening which is associated with changes in collagen, including increased deposition and more diffuse distribution in the submucosa. The cells responsible for production of procollagen are round, nonfibroblast cells which are located in the submucosa and not in the smooth muscle layer. These findings may have some importance in understanding the mechanisms responsible for intestinal malfunction in infants with gastroschisis.
Select Pathways to Carbon Nanotube Film Growth

When such superstructures begin to take the role of basic building blocks, the symmetry of these structures assumes importance in deciding the final film structure and morphology. These superstructures can be found during the growth of organic and inorganic systems, playing an important role in structural evolution during growth, e.g., spherulites during the growth of semi-crystalline polymers. [2] When the fundamental building blocks involved in growth are complex macromolecules or rigid nanostructure units, rather than simple atomic species, the structural evolution of the films will depend on how the units are able to self-organize, attach, and space-fill the substrate surface. The build up of carbon nanotube films on substrates by chemical vapor deposition (CVD) is a striking example of this phenomenon, and has received much attention due to its practical applications. We show in this letter that the film growth of nanotubes occurs via select pathways that involve the nucleation and growth of self-assembled nanotube domains having different shapes and symmetries. Moreover, this process can be controlled by changing the rates of nucleation and growth of the nanotubes on the substrates, leading to domains that are distinctly different in morphology, and leading to nanotube films with a characteristic alignment of individual nanotubes. Individual carbon nanotubes are macromolecular structures with nanosize diameters and micrometer lengths. [3] It has been shown that packed films of nanotubes can be grown on substrates by catalytic CVD of hydrocarbon gases. [4‐10] Although
A self-paired comparison of perioperative outcomes before and after implementation of a clinical pathway in patients undergoing total knee arthroplasty.

Background and Objectives Clinical pathways commonly modify multiple variables and deviate from long-established clinical practices. Therefore, it is difficult to perform prospective, randomized clinical trials comparing “standard care” to the “new clinical pathway.” The goal of this investigation was to examine the impact of clinical pathways implementation on perioperative outcomes and institutional costs in patients undergoing total knee arthroplasty (TKA). Methods This before-and-after study evaluated patient clinical outcomes and economic costs after the implementation of institutional clinical pathway. The primary outcome was hospital length of stay (LOS). Clinical and economic outcomes were analyzed as continuous variables using paired t test. Results Fifty-four patients were identified for study inclusion. Patients undergoing their TKA after implementation of the clinical pathway had a significantly shorter hospital LOS (3.4 vs 4.4 days; P Conclusions Our findings demonstrated that the use of a standardized clinical pathway reduced hospital LOS, improved clinical outcomes and patient satisfaction while reducing costs for identical surgical procedures.
Trading in ancillary services

This paper describes the current arrangements for the procurement of ancillary services and how these services may be procured under NETA. The paper is separated into five sections. The first section outlines the categories of ancillary services that currently exist, the current procurement procedures. The second section outlines recent developments. Section three briefly describes the new market arrangements. Section four summarises Ofgem's views on the procurement of ancillary services under NETA as set out in the recent consultation. Finally, section five outlines the authors' views on the procurement of ancillary services in the future.
The nature of myocardial Z line ridges seen with the scanning electron microscope

Abstract Transverse elevated ridges of the myocardial cell were studied with the scanning electron microscope equipped with a backscattered electron detector and energy dispersive spectrometer to determine their structure. Prominent transverse ridges were observed over the Z lines of the sarcomeres in the secondary electron emission mode of the SEM. These ridges have been interpreted before as either a part of the T tubular system of cardiac muscle or an artifactual manifestation of Z material. Since it is impossible to visualize the lumen of intact tubules with secondary electrons, we infiltrated the heart tissue with extracellular metal tracers and then localized their distribution with the backscattered electron imaging technique (BSE). When examined in the BSE mode, the tissue injected with silver displayed prominent T tubules which contained the metal and otherwise appeared to the ridges in the secondary electron mode. Though lanthanum was present in the interstitial spaces, intercalated disc and T tubules of sectioned cardiac tissue, it formed only faint BSE images over the interstitial spaces. Failure of lanthanum to elicit a strong BSE signal from the tissue was pressumably due to the low concentration of the tracer used. X-ray microanalysis of the cardiac tissue treated with silver revealed the presence of characteristic silver emission over the T tubules. These findings indicate that Z line ridges are T tubules of the myocardial cell and are in direct communication with the extracellular environment.
Management of uveitic glaucoma with Ahmed glaucoma valve implantation

Abstract Objective To evaluate the safety and efficacy of Ahmed glaucoma valve implantation for the management of glaucoma associated with chronic uveitis. Design Retrospective, noncomparative case series. Participants Nineteen patients (21 eyes) with chronic uveitis underwent Ahmed glaucoma valve implantation for uncontrolled glaucoma between 1995 and 1998. Intervention All patients had their uveitis controlled before surgery via immunomodulatory therapy. Ahmed glaucoma valve implantation was performed. Immunosuppression was continued in the early postoperative period for strict control of inflammation. Main outcome measures Control of intraocular pressure (IOP). A secondary outcome measure was the number of antiglaucoma medications required to achieve the desired IOP. Visual acuity and complications associated with the surgery were monitored. Results The postoperative follow-up averaged 24.5 months. At the most recent visit, all 21 eyes had IOPs between 5 and 18 mmHg. The average pressure reduction after Ahmed glaucoma valve implantation was 23.7 mmHg. The average number of antiglaucoma medicines required to achieve the desired IOP was reduced from 3.5 before surgery to 0.6 after surgery. No eye lost even a single line of Snellen acuity at the most recent postoperative visit. Two eyes developed hypotony in the course of follow-up. One resolved without specific intervention, and the other eye required two autologous blood injections and tube ligature to correct the hypotony. One eye underwent Ahmed glaucoma valve replacement for abrupt valve failure. Two eyes underwent penetrating keratoplasty for reasons believed to be unrelated to the glaucoma surgery. Kaplan-Meier life-table analysis showed a cumulative probability of success after Ahmed glaucoma valve implantation of 94% at 1 year. Conclusions Ahmed glaucoma valve implantation can be an effective and safe method in the management of uveitic glaucoma. The authors hypothesize that control of the patients’ uveitis, through preoperative and long-term postoperative immunomodulatory therapy, may have contributed to the success rate reported herein.
Intelligent image processing for machine safety

This paper describes the use of intelligent image processing as a machine guarding technology. One or more color, linear array cameras are positioned to view the critical region(s) around a machine tool or other piece of manufacturing equipment. The image data is processed to provide indicators of conditions dangerous to the equipment via color content, shape content, and motion content. The data from these analyses is then sent to a threat evaluator. The purpose of the evaluator is to determine if a potentially machine-damaging condition exists based on the analyses of color, shape, and motion, and on `knowledge' of the specific environment of the machine. The threat evaluator employs fuzzy logic as a means of dealing with uncertainty in the vision data.© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
SUPERSYMMETRIC SKYRMIONS IN FOUR DIMENSIONS

Abstract Possible topological solitons (skyrmions) of four-dimensional supersymmetric nonlinear σ-models are investigated. The requirements of supersymmetry limit our study to the CP 1 model. A stable soliton seems possible, but in the absence of a demonstrated lower-bound for the mass, the stability of the soliton is unproved. The semi-classical spectrum of the CP 1 skyrmion, as well as its supersymmetric extension, is studied.
Biological electron transfer

Many oxidoreductases are constructed from (a) local sites of strongly coupled substrate-redox cofactor partners participating in exchange of electron pairs, (b) electron pair/single electron transducing redox centers, and (c) nonadiabatic, long-distance, single-electron tunneling between weakly coupled redox centers. The latter is the subject of an expanding experimental program that seeks to manipulate, test, and apply the parameters of theory. New results from the photosynthetic reaction center protein confirm that the electronic-tunneling medium appears relatively homogeneous, with any variances evident having no impact on function, and that control of intraprotein rates and directional specificity rests on a combination of distance, free energy, and reorganization energy. Interprotein electron transfer between cytochromec and the reaction center and in lactate dehydrogenase, a typical oxidoreductase from yeast, are examined. Rates of interprotein electron transfer appear to follow intraprotein guidelines with the added essential provision of binding forces to bring the cofactors of the reacting proteins into proximity.
A systematic approach to the design of secondary school lessons in Guyana

Selected physics and geography classes in Guyanan secondary schools received four different instructional treatments. Three experimental groups received (A) a systematically designed curriculum unit implemented by the designer of the unit (B) the same unit implemented by another teacher and (C) a lesson utilising the aims and objectives defined in the curriculum unit. A fourth (control) group received the conventional lesson for this aspect of the curriculum. Pre- and post-test data revealed significant learning gains in experimental groups. The implications of these results are considered for curriculum development and the training of teachers in Guyana.
Engineering Dense Connective Tissues via Anisotropic Nanofibrous Scaffolds With High Sacrificial Fiber Content

Given their ability to dictate initial cell alignment and subsequent matrix organization, aligned electrospun scaffolds are a fitting means for engineering fiber-reinforced, anisotropic tissues such as tendon, ligament, the knee meniscus, and the annulus fibrosus [1–4]. However, one commonly observed limitation of such scaffolds is the relatively slow infiltration rates of surface-seeded cells, where the central thicknesses of constructs cultured for 10 weeks remain devoid of cells [3]. This limitation arises from the tight packing of fibers which yields small pore sizes, thereby hampering cell migration. Towards accelerating cell ingress, we have recently reported on two-polymer composite scaffolds containing both slow eroding poly(e-caprolactone) (PCL) fibers as well as water-soluble poly(ethylene oxide) (PEO) fibers that serve as space holders during scaffold formation [5]. Removal of these PEO fibers prior to seeding resulted in improved cell infiltration after 3 weeks, but the long-term maturation of such constructs has yet to be characterized. To assess the effect of sacrificial PEO fiber content on construct growth, a triple-jet electrospinning device was employed to generate PCL/PEO scaffolds with PEO fiber fractions ranging from 0 to 60%. After seeding with human meniscus fibrochondrocytes (hMFCs), constructs were clamped in custom grips to maintain strip morphology. The mechanical and biochemical maturation of constructs was assessed over 12 weeks of free swelling culture in a chemically defined medium (CDM), along with cell infiltration and matrix distribution. We hypothesized that enhanced pore size in dual-fiber constructs would lead to not only to a better distribution of cells, but also to larger increases in stiffness resulting from enhanced matrix production and distribution.Copyright © 2010 by ASME
Immunocytochemical localization of an insulin-like substance in the synganglion of the tick Ornithodoros parkeri (Acari: Argasidae).

Immunocytochemical staining based on the peroxidase-antiperoxidase method has shown that some neurosecretory cells (NSC) in the synganglion of the adult female tickOrnithodoros parkeri react with an antibody to bovine insulin. There are 18 regions of paraldehyde fuchsin-positive NSC of which three regions showed specific insulin-like immunoreactivity: anterolateral cheliceral, anteromedial stomodeal and posterior opisthosomal. Immunoreactivity can also be found in the extracellular surface of the neurilemma of the synganglion. This suggests a possible neurohemal site and release of neurohormone in a diffuse manner.
Cross-Country Nonparametric Analysis of Bahrains Banking System

Bahrains financial sector development strategy succeeded in building a leading regional banking center, which has become one of the main engines of growth and sources of employment. Based on bank- level productivity estimates obtained using non-parametric estimation, the paper concludes that Bahrain continues to occupy a front-runner position among sample GCC countries. Results also reveal that: (i) banks in Bahrain still lag behind their Singaporean counterparts (included in the study as a benchmark), and (ii) there is strong competition from other countries in the region. The results appear to be robust with respect to changes in the sample size and model specifications.
Association of Duchenne Muscular Dystrophy With Autism Spectrum Disorder

We hypothesize that Duchenne muscular dystrophy and autism spectrum disorder/pervasive developmental disorder co-occur with a greater than random frequency. In this study, we set out to reject the hypothesis that Duchenne muscular dystrophy and autism spectrum disorder/pervasive developmental disorder co-occur no more often than expected by chance. Two index cases and six additional boys with concomitant Duchenne muscular dystrophy and autism spectrum disorder were identified in a muscular dystrophy clinic that approximates the total number of Duchenne muscular dystrophy boys (158) in the state of Massachusetts. The rate of prevalence (6 of 158) was compared with the prevalence rate of autism spectrum disorder in boys in the general population (1.6 in 1,000). We rejected the hypothesis that Duchenne muscular dystrophy and autism spectrum disorder co-occurrence was likely to be explained by chance (P = .006). We identify a previously unrecognized association of Duchenne muscular dystrophy with autism spectrum disorder. Further work might elucidate the level of association between these two conditions, either at the genetic or at the protein level, and might clarify, at least partially, the neurobiologic mechanisms associated with autism spectrum disorder.
Comparison of aircraft, ground-rig and center pivot irrigation systems for application of pesticides to potatoes

Studies were conducted from 1979 to 1983 in central Wisconsin to investigate the utilization of center pivot irrigation systems for the application of pesticides to potatoes. Fungicides, herbicides and insecticides were applied with a conventional tractor-mounted boom sprayer, a boom mounted beneath the center pivot (underslung boom), direct injection into the center pivot irrigation water and by aircraft. In comparisons between irrigation system application and tractor-mounted boom application, materials through both the underslung boom and center pivot system provided comparable pest control to the tractor-mounted boom, with the exception of water soluble insecticides which were ineffective when applied through the irrigation system. In addition, under intense disease pressure a somewhat reduced efficacy was associated with fungicides applied through the center pivot system compared to tractor-mounted boom applications. Comparison of center pivot pesticide applications with aerial and tractor-mounted boom applications in 65 ha commercial fields in 1982 and 1983, showed that all application methods provided acceptable levels of pest control, and comparable tuber yields.
Protein kinase C and A sites on troponin I regulate myofilament Ca2+ sensitivity and ATPase activity in the mouse myocardium.

Cardiac troponin I (cTnI) is a phosphoprotein subunit of the troponin-tropomyosin complex that is thought to inhibit cardiac muscle contraction during diastole. To investigate the contributions of cTnI phosphorylation to cardiac regulation, transgenic mice were created with the phosphorylation sites of cTnI mutated to alanine. Activation of protein kinase C (PKC) by perfusion of hearts with phorbol-12-myristate-13-acetate (PMA) or endothelin-1 (ET-1) inhibited the maximum ATPase rate by up to 25 % and increased the Ca2+ sensitivity of ATPase activity and of isometric tension by up to 0.15 pCa units. PKC activation no longer altered cTnI phosphorylation, depressed ATPase rates or enhanced myofilament Ca2+ sensitivity in transgenic mice expressing cTnI that could not be phosphorylated on serines43/45 and threonine144 (PKC sites). Modest changes in myosin regulatory light chain phosphorylation occurred in all mouse lines, but increases in myofilament Ca2+ sensitivity required the presence of phosphorylatable cTnI. For comparison, the β-adrenergic agonist isoproterenol caused a 38 % increase in maximum ATPase rate and a 0.12 pCa unit decrease in myofilament Ca2+ sensitivity. These β-adrenergic effects were absent in transgenic mice expressing cTnI that could not be phosphorylated on serines23/24 (protein kinase A, PKA, sites). Overall, the results indicate that PKC and PKA exert opposing effects on actomyosin function by phosphorylating cTnI on distinct sites. A primary role of PKC phosphorylation of cTnI may be to reduce the requirements of the contractile apparatus for both Ca2+ and ATP, thereby promoting efficient ATP utilisation during contraction.
Impact Ionization Can Explain Carrier Multiplication in PbSe Quantum Dots

The efficiency of conventional solar cells is limited because the excess energy of absorbed photons converts to heat instead of producing electron-hole pairs. Recently, efficient carrier multiplication has been observed in semiconductor quantum dots. In this process, a single, high-energy photon generates multiple electron-hole pairs. Rather exotic mechanisms have been proposed to explain the efficiency of carrier multiplication in PbSe quantum dots. Using atomistic pseudopotential calculations, we show here that the more conventional impact ionization mechanism, whereby a photogenerated electron-hole pair decays into a biexciton in a process driven by Coulomb interactions between the carriers, can explain both the rate (<<1 ps) and the energy threshold ( approximately 2.2 times the band gap) of carrier multiplication, without the need to invoke alternative mechanisms.
On the structures, stabilities and fragmentation patterns of carbon clusters including Buckminsterfullerene

Abstract The heats of formation and optimum structures of various neutral C n clusters ( n s ⩽∼60) and linear C3 n + cations ( n ⩽40) were determined by quantum chemical calculations. Buckminsterfullerene is thermodynamically more stable than the next stable form of C 60 by about 600 kcal/mol. C 60 and C 70 fullerenes belong to a series of fullerenes C 10 m +40 ( m ⩾2) that are derived from C 10 m cylinders and C 20 capping units. In the fragmentation of C n and C n + clusters, the preference for the C 2 or C 3 loss is predicted to depend upon whether the clusters have structures with mainly two- or three-coordinate carbon atoms.
The use of air abrasion for successful adhesive prosthodontics.

E .M. Forster stated in 1937 that, faced with a choice between betraying his friend and betraying his country, he hoped he would have the guts to betray his country. Since then, in the minds of a certain number of American and British intellectuals, friendship, courage ("guts"), and treason have had a certain connection--a potential connection if not an actual one. Once as black a crime as there was in the normal scheme of things, treason has become somehow more "forgivable" under a wider set of circumstances than it was earlier. Among some intellectuals, a small but not insignificant number, the climate of thinking about treason and traitors has changed dramatically since the end of World War II, even more particularly since the end of the 1960s. There is, and there has been, a lot of muddled thought and misguided sentimentality regarding treason. What is most needed is clear thought and a certain kind of moral courage in confronting the implications of treason. There is no denying the fascination of treason as an object of intellectual inquiry and contemplation. What makes people betray their country? When is treason justified? What is treason? What are the limits of the claim the state is entitled to make on a citizen's allegiance? There is a lot of philosophy lurking in such questions, and only fanatics can find easy answers. There are legal definitions of treason, but these interest lawyers more than the rest of us. A more important observation is that there has never been a clear line telling us when treason is wrong and when it is not wrong. A little reflection and a knowledge of history tell us that there can never be one. Some cases are clear--and then there are all the others. Rebecca West wrestled with the problem directly after World War II, using the trial of the fascist William Joyce ("Lord Haw-Haw") as her springboard, and she extended the analysis as the British traitors in the Communis t cause (Klaus Fuchs, Bruno Pontecorvo, Alan Nunn May, Burgess, Maclean) came on line in the fifties and sixties. Her agreeably tough-minded and commonsens ica l opinion was that treason is usually very wrong but not always; it depends, among other things, on how bad is the regime against which treason is committed. West wrote in The New Meaning of Treason:
Carcinoid tumors of the rectum: effect of size, histopathology, and surgical treatment on metastasis free survival.

BACKGROUND The purpose of this study was to determine the clinical course, effects of specific tumor histopathologic characteristics, and extent of surgical treatment on the metastatic rate in patients with rectal carcinoids. METHODS Medical records of 44 patients who presented with rectal carcinoids were retrospectively reviewed. Primary tumors were classified by size ( 2 cm), and tumor histopathologic features (atypical or typical). Extensive surgery was defined as abdominoperineal or low anterior resection of the rectum or laparotomy with intent of curative resection. RESULTS Median follow-up for patients who presented without metastasis was 84 months. Thirteen of the 44 patients (30%) presented with metastatic disease. The 5-year metastasis free survival rates for those patients presenting without metastatic disease were 100% for patients with tumors 2 cm (n = 4) (P = 0.04 comparing 2 cm); tumor size data were not available for 3 patients. The 5-year metastasis free survival rate for patients presenting without metastatic disease with typical histology (n = 20), regardless of size, was 100%, compared with 50% for patients with tumors with atypical histology (n = 11) (P = 0.001). Nine patients underwent extensive surgery for rectal carcinoid tumors but no survival benefit was demonstrated. CONCLUSIONS Atypical histopathologic features and a tumor size > 1 cm are associated with aggressive behavior of rectal carcinoid tumors. Extensive surgery offers no survival advantage over local excision for patients with rectal carcinoid tumors. Cancer 1997; 79:1294-8. © 1997 American Cancer Society.
Tissue Drug Residue Extraction and Monitoring by Matrix Solid Phase Dispersion (MSPD)-HPLC Analysis

Abstract The increasing implementation of immuno-, receptor and microbial inhibition screening tests for the monitoring of drug residues in foods of animal origin also requires that we be capable of confirming and validating the results of such tests in a timely manner. Methodology for the isolation and analysis of “detected” substances must be capable of performing rapid and efficient extractions that are amenable to instrumental determinations for the presence, level and, where possible, identity of the substance in question. We present here a summary of such methodolgy utilizing matrix solid phase dispersion (MSPD) as the isolation method and several simple isocratic HPLC/UV diode array and florescence methods developed for extracts so obtained for several drug classes as well as individual drugs. The application of these methods for a variety of purposes in drug residue monitoring programs is discussed.
Prehistoric settlement and landscape change on alluvial fans in the upper Mississippi river valley

Geoarchaeological studies of alluvial fans in the northern Sny Bottom (Upper Mississippi River valley) focused on distal fan lobe processes, the effects of small-scale landscape change on prehistoric locational decisions, and the resulting structure of the archaeological record. Aerial imagery together with coring and trenching of paleochannels on distal lobes found that frequent channel avulsion (1) produced abrupt landform/habitat changes and (2) shifted the primary loci of sediment deposition on fans through time. Analysis of wood charcoal from prehistoric occupations indicates that vegetation succession during post-avulsion overbank aggradation along a new channel was characterized by a shift from Fraxinus-dominated to mesophytic forest. Results also indicate that use of fans by Early Woodland (ca. 2550–2100 B.P.) and other foragers centered on portions along active channels. Shifting depositional loci on fans led to surfaces and depositional units of varying age, and hence a complex stratigraphic record of Holocene occupations.
Thyroid al Synthesis of Phosphatidic Acid

The enzymatic formation of phosphatidic acid from l-α-glycerophosphate and fatty acid was studied in cell free systems of calf and guinea pig thyroid. Phosphatidic acid formation was assayed by measuring the conversion of water-soluble l-α-glycerophosphate to the lipid which is extractable by organic solvents. Palmitate or endogenous fatty acids could serve as cosubstrate in the presence of coenzyme A (CoA) and adenosine triphosphate (ATP). Palmityl-CoA served as cosubstrate in the absence of CoA or ATP. The synthetic system was found in highest concentration in the particulate fraction of ruptured thyroid cells which sedimented between 8500 and 100,000 ×g. The system has a pH optimum of 7.5, has an absolute Mg requirement, is not inhibited by Ca, and does not require sulfhydryl groups (aside from reduced CoA). This system is essentially similar to that known to exist in liver and involves 2 enzymes: the first, acyl-CoA synthetase, forms the CoA derivative of long chain fatty acids in the presence of ATP,...
Angiotensin II induces membrane trafficking of natively expressed transient receptor potential vanilloid type 4 channels in hypothalamic 4B cells

Transient receptor potential vanilloid family type 4 (TRPV4) channels are expressed in central neuroendocrine neurons and have been shown to be polymodal in other systems. We previously reported that in the rodent, a model of dilutional hyponatremia associated with hepatic cirrhosis, TRPV4 expression is increased in lipid rafts from the hypothalamus and that this effect may be angiotensin dependent. In this study, we utilized the immortalized neuroendocrine rat hypothalamic 4B cell line to more directly test the effects of angiotensin II (ANG II) on TRPV4 expression and function. Our results demonstrate the expression of corticotropin-releasing factor (CRF) transcripts, for sex-determining region Y (SRY) (male genotype), arginine vasopressin (AVP), TRPV4, and ANG II type 1a and 1b receptor in 4B cells. After a 1-h incubation in ANG II (100 nM), 4B cells showed increased TRPV4 abundance in the plasma membrane fraction, and this effect was prevented by the ANG II type 1 receptor antagonist losartan (1 μM) and by a Src kinase inhibitor PP2 (10 μM). Ratiometric calcium imaging experiments demonstrated that ANG II incubation potentiated TRPV4 agonist (GSK 1016790A, 20 nM)-induced calcium influx (control 18.4 ± 2.8% n = 5 and ANG II 80.5 ± 2.4% n = 5). This ANG II-induced increase in calcium influx was also blocked by 1 μM losartan and 10 μM PP2 (losartan 26.4 ± 3.8% n = 5 and PP2 19.7 ± 3.9% n = 5). Our data suggests that ANG II can increase TRPV4 channel membrane expression in 4B cells through its action on AT1R involving a Src kinase pathway.
Current Trends in Streptococcus pneumoniae Infections and Their Treatment

Invasive pneumococcal disease (IPD) is a major cause of pediatric morbidity and mortality in resource-rich and low and middle-income countries (LMICs). Streptococcus pneumoniae can cause a wide spectrum of invasive and non-invasive disease. In resource-rich countries, implementation of 7-valent pneumococcal conjugate vaccine (PCV7) has been a significant public health achievement. Dramatic decrease in pediatric IPD incidence occurred after PCV7 implementation, but emergence of multi-drug-resistant non-vaccine serotypes (especially 19A) remains a concern. The recently introduced 13-valent PCV (PCV13) has the potential to further reduce the burden of IPD due to serotypes not contained in PCV7. Given the diversity of pneumococcal serotypes and the possibility of serotype replacement disease, innovative approaches to development of pneumococcal vaccines are needed. Continued surveillance of pneumococcal serotypes and antimicrobial resistance is crucial to evaluate the impact of PCV13 vaccine. Improved access to PCVs is crucial to reduce morbidity and mortality related to IPD in LMIC.
Two-dimensional simulation of Far-Ultraviolet Spectroscopic Explorer (FUSE) spectra

The FUSE satellite will make high spectral resolving power measurements of astrophysical objects in the 905-1187 angstrom wavelength region from low-earth orbit. Its high effective area and low background will permit observations of solar system, galactic, and extragalactic targets that have been too faint for previous instruments at this high resolution. The spectra produced by the FUSE instrument are complex, 2D images which must be transformed into simple 1D spectra for analysis. In anticipation of the complications involved in this conversion, and because calibration spectra taken on the ground imperfectly represent the results expected on orbit, a detailed computer model of the instrument and satellite has been developed. This model includes the expected performance and alignment of the optical elements and detectors, in addition to other factors such as the spacecraft pointing stability. Using this model, realistic simulated spectra can be generated in order to exercise the processing pipeline and develop data extraction techniques. A description of the computer model is presented, and sample spectra are shown.
Frequency-agile hyper-Rayleigh scattering studies of electro-optic chromophores

Hyper-Rayleigh scattering (HRS) is used to measure the first-hyperpolarizability (β) of electro-optic (EO) chromophores. One of the inherent concerns in any HRS measurement is the extent to which resonant enhancement contributes to the observed intensity thereby leading to inaccuracies when evaluating chromophore potential for application in electro-optical devices. One way to address this concern is to employ increasingly longer excitation wavelengths far from resonance. However, in charge-transfer-based non-linear optical chromophores, enhanced β generally correlates with a red-shift of the charge transfer absorption band so that even at the longest excitation wavelengths generally employed in HRS studies, resonant enhancement remains an issue. We have adopted an alternative approach in which the wavelength dispersion of the HRS intensity is determined by performing measurements at a variety of excitation wavelengths. This approach allows one to ascertain the role of resonance enhancement thereby allowing for more accurate correlation of improved β with molecular architecture. We report the results of our HRS studies for nine chromophores employing excitation wavelengths ranging from 780 to 1907 nm. Our HRS results demonstrate good agreement with the predictions of density functional theory. This synthesis of experimental and theoretical techniques has resulted in more effective designs for the next generations of electro-optical chromophores.
B vitamins, methionine and alcohol intake and risk of colon cancer in relation to BRAF mutation and CpG island methylator phenotype (CIMP).

Background: One-carbon metabolism appears to play an important role in DNA methylation reaction. Evidence suggests that a low intake of B vitamins or high alcohol consumption increases colorectal cancer risk. How one-carbon nutrients affect the CpG island methylator phenotype (CIMP) or BRAF mutation status in colon cancer remains uncertain. Methods: Utilizing incident colon cancers in a large prospective cohort of women (the Nurses’ Health Study), we determined BRAF status (N=386) and CIMP status (N=375) by 8 CIMP-specific markers [CACNA1G, CDKN2A (p16), CRABP1, IGF2, MLH1, NEUROG1, RUNX3, and SOCS1], and 8 other CpG islands (CHFR, HIC1, IGFBP3, MGMT, MINT-1, MINT-31, p14, and WRN). We examined the relationship between intake of one-carbon nutrients and alcohol and colon cancer risk, by BRAF mutation or CIMP status. Results: Higher folate intake was associated with a trend towards low risk of CIMP-low/0 tumors [total folate intake $400 mg/day vs. ,200 mg/day; the multivariate relative risk=0.73; 95% CI=0.53–1.02], whereas total folate intake had no influence on CIMP-high tumor risks (Pheterogeneity=0.73). Neither vitamin B6, methionine or alcohol intake appeared to differentially influence risks for CIMP-high and CIMP-low/0 tumors. Using the 16-marker CIMP panel did not substantially alter our results. B vitamins, methionine or alcohol intake did not affect colon cancer risk differentially by BRAF status. Conclusions: This molecular pathological epidemiology study suggests that low level intake of folate may be associated with an increased risk of CIMP-low/0 colon tumors, but not that of CIMP-high tumors. However, the difference between CIMP-high and CIMP-low/0 cancer risks was not statistically significant, and additional studies are necessary to confirm these observations.
Quiero Hablar Con Usted en Espanol, Juez: The Importance of Spanish at a Majority Hispanic Drug Court

We modified the participant perception survey utilized in the Multi-Site Adult Drug Court Evaluation and administered it to participants at a majority Hispanic drug court in south Texas. Results re...
Singular limits of quasilinear hyperbolic systems with large parameters and the incompressible limit of compressible fluids

Many interesting problems in classical physics involve the limiting behavior of quasilinear hyperbolic systems as certain coefficients become infinite. Using classical methods, the authors develop a general theory of such problems. This theory is broad enough to study a wide variety of interesting singular limits in compressible fluid flow and magneto-fluid dynamics including new constructive local existence theorems for the time-singular limit equations. In particular, the authors give an entirely self-contained classical proof of the convergence of solutions of the compressible fluid equations to their incompressible limits as the Mach number becomes small. The theory depends upon a balance between certain inherently nonlinear structural conditions on the matrix coefficients of the system together with appropriate initialization procedures. Similar results are developed also for the compressible and incompressible Navier-Stokes equations with periodic initial data independent of the viscosity coefficients as they tend to zero.
Linear r-Mode Oscillations in a Differentially Rotating Star

Differential rotation of a stellar envelope lifts the degeneracy of r-mode rotation rates and can prohibit some modes. It also reduces the physical distinction between the two branches of r-modes: slow (retrograde) and fast (geostrophic). One mode in each branch is dominated by a given spherical harmonic (l, m), and, for increasing rotational shear in the star, their characteristics approach each other until both modes simultaneously cease to exist. Only about half of the 60 r-modes with l ≤ 5 and a given radial harmonic can survive as global, linear modes in the Sun. Each of these has at least 70%, and typically 90%, of its energy in a single toroidal component of motion. Among solar survivors are all modes where | m | = l > 1. All results apply to linear, adiabatic oscillations of a spherical fluid shell exhibiting steady, axisymmetric rotation, Ω(r, θ). Since terms ~Ω2 are small in the Sun, spheroidal motions are neglected. A generalization of classical perturbation theory was used to treat "perturbations" of large size and to avoid the need for special treatment of oscillation frequencies that are zero or degenerate.
Financing democracy in Japan: The allocation and consequences of government subsidies to political parties

In 1994, the Japanese Diet implemented a system of public assistance for political parties which many hoped would encourage party-centred rather than candidate-centred campaigns. This study examines some of the consequences of this system for party organizations and politicians. Using data culled from official subsidy and campaign finance reports, two empirical questions are addressed: first, how has the advent of the subsidy affected the funds available to national party organizations and to individual politicians? Second, what are the factors that shape the allocation of the subsidy from national party organizations to party branches? It is argued that the subsidy has made it easier for party organizations to access funds but that the amounts of subsidies received by individual politicians are generally too small to alleviate much of their fund-raising pressures. In addition, party leaders have allocated the subsidy largely by following a principle of equality.
Influence of the Pineal Gland on Gonadal Maturation in the Japanese Quail

Pinealectomy resulted in decreased ovarian weight, decreased oviducal and adenohypophyseal weights and delayed onset of oviposition in birds exposed to a stimulatory 16-hr photoperiod (16L:8D). This delay in maturation occurred only in females and was transient. The effects of pinealectomy were reversed by multiple pineal implants. Pinealectomized females exposed to continuous light (24LL) showed a similar delay in maturation. Hence, the pineal gland in female Coturnix has a stimulatory influence on the time of ovarian maturation. When ovarian growth rate was markedly reduced by treatment with a nonstimulatory photoperiod (8L:16D), pinealectomy was without effect. Exogenous doses of melatonin did not alter gonadal growth in intact females or males, both juvenile and adult. (Endocrinology 83: 1237, 1968)
Genetics and community health nursing

Genetic discoveries affect the practice of community health nurses. These nurses identify groups at risk for genetic diseases and participate in newborn screening, carrier detection testing, and presymptomatic genetic testing programs. Community health nurses also provide direct nursing care to individuals with genetic disorders. Protecting clients from harmful use of genetic information, planning and implementing genetic screening programs, and identifying genetic resources are essential components of the community health nurse's role.
Clinical and pathologic studies in the hereditary syndrome of a long QT interval, syncopal spells and sudden death.

Clinical and pathologic investigations of a family whose members suffered from a heritable syndrome of syncopal spells, sudden death, and QT interval prolongation on the electrocardiogram are reported. All members had normal hearing. The mode of inheritance appeared to be autosomal dominance. The syndrome is very similar to one first reported in 1957 by Jervell and Lange-Nielsen except in the latter disorder, nerve-deafness is present and the mode of inheritance is autosomal recessive. In the syndromes reported, attacks of syncope and sudden death are usually due to ventricular fibrillation and this is frequently triggered by physical or acute emotional stress. Of importance and as illustrated by the propositus of this study, the electrocardiogram may be normal at rest only to show the characteristic bizarre QT prolongation after exercise. Pathologic study of the heart of one of the family members who died suddenly revealed diffuse and extensive fibrosis of the conducting system along with abnormal changes in the small arterial vessels in this area. The part these lesions play in the pathogenesis of the clinical syndrome is not entirely clear. The syndrome is probably more unrecognized than rare and may explain a number of instances of “atypical seizures.” Any individual with such seizures should have an electrocardiogram, preferably after exercise, as an integral part of the diagnostic evaluation.