cssi/SciSciGPT-SciSciNet huggingface dataset:
Mapping the Active Site Helix-to-Strand Conversion of CxxxxC Peroxiredoxin Q Enzymes

Peroxiredoxins (Prx) make up a family of enzymes that reduce peroxides using a peroxidatic cysteine residue; among these, members of the PrxQ subfamily are proposed to be the most ancestral-like yet are among the least characterized. In many PrxQ enzymes, a second “resolving” cysteine is located five residues downstream from the peroxidatic Cys, and these residues form a disulfide during the catalytic cycle. Here, we describe three hyperthermophilic PrxQ crystal structures originally determined by the RIKEN structural genomics group. We reprocessed the diffraction data and conducted further refinement to yield models with Rfree values lowered by 2.3–7.2% and resolution extended by 0.2–0.3 A, making one, at 1.4 A, one of the best resolved peroxiredoxins to date. Comparisons of two matched thiol and disulfide forms reveal that the active site conformational change required for disulfide formation involves a transition of ∼20 residues from a pair of α-helices to a β-hairpin and 310-helix. Each conformation h...
Alkynlphosphazenes : synthesis, reactions and incorporation into polymers

Abstract The regio- and stereochemical pathways followed in the reactions of the lithioacetylenes, LiC=CR (R=Ph31 Me, n-19Bu), with N3P3F6 have been examined by 31P and 19F NMR spectrscopy. Mixed propenylphenyl, phenylacetylene derivatives were also prepared. The products formed in these reactions demonstrate substituent control of the reaction pathway. Copolymerization of propenylphenyl alkynlphosphazenes with styrene gives polymers which add dicolbalt hexacarbonyl and undergo a one electron, chemical reversible reduction.
Underestimating the impact of ventilator-associated pneumonia by use of surveillance data.

We calculated rates of ventilator-associated pneumonia (VAP) by using surveillance data, clinical data, and coding data. Compared with the VAP rates calculated on the basis of surveillance data, the VAP rates calculated on the basis of coding data were significantly overestimated in 4 of 5 intensive, care units. Efforts to improve coding and clinical documentation will address much but not all of this discrepancy between surveillance and administrative data.
Immunological-chromatographic analysis.

Abstract Tandem immunoaffinity and conventional high-performance liquid chromatography columns, coupled with a switching valve, were used for the analysis of single and multicomponent antigen samples. Immunoaffinity columns were prepared by hydrophobic adsorption or covalent immobilization of poly- or monoclonal anti-bodies on macroporous poly(styrene-divinylbenzene) packing materials. Capacities of these columns were constant through at least 77 cycles. Macromolecular antigens were analyzed at submicrogram levels. Antigens bound to be immunoaffinity column were desorbed and concentrated on a conventional analytical column. Gradient elution on the analytical column separated the desorbed antigen(s) from interfering species and permitted the analysis of all species which bound to the immunoaffinity column. Immunological-chromatographic analysis was useful for purification and discrimination of polypeptides of similar three dimensional structures, such as several lysozyme variants.
Long-PCR based next generation sequencing of the whole mitochondrial genome of the peacock skate Pavoraja nitida (Elasmobranchii: Arhynchobatidae)

We determined the complete mitochondrial genome sequence (16,760 bp) of the peacock skate Pavoraja nitida using a long-PCR based next generation sequencing method. It has 13 protein-coding genes, 22 tRNA genes, 2 rRNA genes, and 1 control region in the typical vertebrate arrangement. Primers, protocols, and procedures used to obtain this mitogenome are provided. We anticipate that this approach will facilitate rapid collection of mitogenome sequences for studies on phylogenetic relationships, population genetics, and conservation of cartilaginous fishes.
Analysis of errors associated with passive ventilation measurement techniques

Abstract In small building where ventilation is the primary mechanism for removing indoor air pollutants, interest in converting the resulting energy load on the heating or cooling system of the building is significant. The desire of making field measurements of this time-varying quantity has led to the development of many approaches. The simplest one is called the passive ventilation measurement technique which typically measures the average concentration of a constantly emitted tracer gas from which the average ventilation rate can be estimated. This study relied on mathematical models combined with typical wheather data to calculate how an ideal passive ventilation measurement would perform; simulations were then conducted based on two house types in four seasons and six climates. It was found that the passive technique significantly underpredicted the average ventilation and that the use of multiple tracers accomplished marginal improvement. Inadequate mixing was found to be a major impediment to the interpretation of the results and could completely invalidate the measurement. Not covered in this report are the additional errors associated with measurement uncertainty, instrumentation limitations and non-ideal experimental conditions.
Surface modification of a perfluorinated ionomer using a glow discharge deposition method to control protein adsorption

Nafion™ is the membrane material preferred for in situ glucose sensors. Unfortunately, surface properties of Nafion promote random protein adsorption and eventual foreign body encapsulation thus leading to loss of glucose signal over time. Here we detail surface modifications made by RF plasma deposition to Nafion with the intent to prevent random protein adsorption while providing enough functional sites (hydroxyl groups) to bind a biologically active peptide known to induce cellular adhesion (YRGDS). Nafion surfaces were modified by RF plasma polymerizing five different combinations of (1) tetraethylene glycol dimethyl ether (tetraglyme) and (2) 2-hydroxyethyl methacrylate (HEMA): pure tetraglyme, 2.5% HEMA with 97.5% tetraglyme, 5% HEMA with 95% tetraglyme, 10% HEMA with 90% tetraglyme, and pure HEMA. Resultant surfaces were characterized by XPS (low and high resolution), dynamic contact angle, and atomic force microscopy. Protein adsorption and retention was determined and correlated to surface layer composition. The ability to bind a cell adhesion peptide was also determined and correlated well with surface layer composition.
The role of systemic chemotherapy in the management of granulosa cell tumors

Objective Granulosa cell tumors (GCTs) are rare, and the role of chemotherapy in their management is not clearly defined.
Approximations for weakly nonlinear evolution equations

Convergence of approximations for a large class of weakly nonlinear parabolic and hyperbolic equations is proven. The main emphasis is on proving convergence of finite element and spectral Galerkin approximations of solutions to the weakly nonlinear wave equation u"(t) + Au(t) = F(t, u(t), u'(t)), u(0) = xo, u'(0) = yo, under minimal assumptions on the linear operator A and on the approximation spaces. A can be a very general elliptic operator (not just of 2nd order and not necessarily in a bounded domain); A can also be very singular and degenerate. The results apply also to systems of equations. Verification of the hypotheses is completely elementary for a large class of problems. 1. Overview. Approximations of solutions to initial value problems of the form (1) u'(t) + Au(t) = F(t, u), u(O) = xo, are studied. The basic results, in rather abstract form, are presented in Section 2. They can be used to prove convergence of finite difference, finite element, spectral, etc., approximations of weakly nonlinear hyperbolic and parabolic equations. Throughout the paper it is assumed that the nonlinear operator F is Lipschitz continuous in u, and for this reason, (1) is said to be weakly nonlinear (-A is the generator of a strongly continuous semigroup). The approach used to prove these results has origins in works of Kato [17], Trotter [29], Segal [27]. Section 3 contains a version of the results of Section 2 that is suitable for proving convergence of finite element approximations of solutions to the weakly nonlinear wave equation u"(t) + Au(t) = F(t, u(t), u'(t)), u(O) = xo, u'(O) = yo (Theorem 3.5) and to weakly nonlinear parabolic problems (Theorem 3.3). Theorem 3.5 is new. The main emphasis is on requiring as little as possible on the linear operator A and on the approximation spaces. A can be a very general elliptic operator (not just of 2nd order and not necessarily in a bounded domain); A can also be very singular and degenerate. Theorem 4.2 of Section 4 is perhaps the most interesting new result. It is a consequence of Theorem 3.5 and of the remarkable fact that sectorial operators have Friedrichs extensions. By using the Friedrichs extension one can bypass the "energy space" that is used in variational methods and this makes it possible to state the assumptions of Theorem 4.2 in a form that can be verified in a completely elementary way for a very general wave equation. Received July 11, 1988. 1980 Mathematics Subject Classification (1985 Revision). Primary 65M60, 65J15, 35L70, 35L80, 47B44. ? 1989 American Mathematical Society 0025-5718/89 $1.00 + $.25 per page
A modified epon embedding and counterstaining procedure for light microscopic examination of Golgi impregnated neurons in vertebrates

Abstract Tissue blocks impregnated with the Golgi-Kopsch method were embedded in a modified Epon formulation (1.5 parts DDSA, 1 part Epon 812, 1.9% DMP-30). Sections 150 μm thick were cut with a steel knife on a sliding microtome. The surface of the sections were counterstained with basic dyes to localize Golgi-impregnated neurons within cyto-architectonically defined areas. Neither the embedding nor counterstaining procedure appeared to adversely affect the quality of the Golgi preparation.
Development of a method for the purification and culture of rodent astrocytes

The inability to purify and culture astrocytes has long hindered studies of their function. Whereas astrocyte progenitor cells can be cultured from neonatal brain, culture of mature astrocytes from postnatal brain has not been possible. Here, we report a new method to prospectively purify astrocytes by immunopanning. These astrocytes undergo apoptosis in culture, but vascular cells and HBEGF promote their survival in serum-free culture. We found that some developing astrocytes normally undergo apoptosis in vivo and that the vast majority of astrocytes contact blood vessels, suggesting that astrocytes are matched to blood vessels by competing for vascular-derived trophic factors such as HBEGF. Compared to traditional astrocyte cultures, the gene profiles of the cultured purified postnatal astrocytes much more closely resemble those of in vivo astrocytes. Although these astrocytes strongly promote synapse formation and function, they do not secrete glutamate in response to stimulation.
Enhancing molecular discovery using descriptor‐free rearrangement clustering techniques for sparse data sets

This article presents a descriptor-free method for estimating library compounds with desired properties from synthesizing and assaying minimal library space. The method works by identifying the optimal substituent ordering (i.e., the optimal encoding integer assignment to each functional group on every substituent site of molecular scaffold) based on a global pairwise difference metric intended to capture smoothness of the compound library. The reordering can be accomplished via a (i) mixed-integer linear programming (MILP) model, (ii) genetic algorithm based approach, or (iii) heuristic approach. We present performance comparisons between these techniques as well as an independent analysis of characteristics of the MILP model. Two sparsely sampled data matrices provided by Pfizer are analyzed to validate the proposed approach and we show that the rearrangement of these matrices leads to regular property landscapes which enable reliable property estimation/interpolation over the full library space. An iterative strategy for compound synthesis is also introduced that utilizes the results of the reordered data to direct the synthesis toward desirable compounds. We demonstrate in a simulated experiment using held out subsets of the data that the proposed iterative technique is effective in identifying compounds with desired physical properties. © 2009 American Institute of Chemical Engineers AIChE J, 2010
Applications of a commercially available current conveyor

It is demonstrated that a commercially available integrated circuit, the AD844 from Analog Devices, implements a current conveyor.
Identification of communicating branches among the dorsal, perineal and cavernous nerves of the penis.

ABSTRACTPurpose: The mechanism of human erection requires the coordination of an intact neuronal system that includes the cavernous, perineal, and dorsal nerves of the penis. We defined the communication of these 3 nerves that travel under the pubic arch using specific neuronal immunohistochemical staining and 3-dimensional reconstruction imaging technique.Materials and Methods: A total of 18 normal human fetal penile specimens at 17.5 to 32 weeks of gestation were studied by immunohistochemical techniques. Serial sections were stained with antibodies raised against the neuronal markers S-100, and neuronal nitric oxide synthase (nNOS), vesicular acetylcholine transporter (VAChT), calcitonin gene-related peptide and substance P.Results: The continuation of the dorsal neurovascular bundle of the prostate was documented under the pubic arch. Two distinct nerve bundles were identified superior to the urethra and medial to the origin of the crural bodies. Nerve bundles were observed to join the corporeal bodie...
Dispersion of initially compact dense gas clouds

Abstract Many field and laboratory experiments on the dispersion of isothermal dense gas clouds use initial cloud shapes having nearly equal vertical and horizontal dimensions, termed initially compact clouds. The earliest stage of mixing, dominated by the initial spreading motion of the cloud, is modeled in this paper as one having a constant global entrainment rate, the empirical value of which is obtained from comparisons with dense gas cloud releases in still air. By adding to this initial entrainment that due to wind turbulence (as modified by cloud stratification), a good correlation is found for dispersion in wind tunnel tests of initially compact dense gas clouds. This initial high rate of entrainment was found to be missing in wind tunnel experiments using non-compact clouds. Although no quantitative criterion is available to distinguish among these initial shapes, their effects are eventually erased by the wind driven mixing.
Interaction of age, cognitive function, and gait performance in 50–80-year-olds

The variability of walking gait timing increases with age and is strongly related to fall risk. The purpose of the study was to examine the interaction of age, cognitive function, and gait performance during dual-task walking. Forty-two, healthy men and women, 50–80 years old, completed the Mini-Mental State Exam (MMSE) and Trail Making Test (TMT) to assess cognitive performance and were separated into groups by decade of life. They then performed dual-task walking, at a self-selected pace, on an instrumented treadmill during three cognitive loading conditions: (1) no cognitive load, (2) subtraction from 100 by 1s, and (3) subtraction from 100 by 3s. The treadmill recorded spatiotemporal gait parameters that were used to calculate the mean and coefficient of variation for each variable over ten strides. Time to complete the TMT was positively correlated with age, stride time, double-limb support time, and mediolateral instability and was inversely correlated with single-limb support time. Subjects in their 70s increased their stride time and double-limb support time during the most challenging dual-task condition (subtraction by 3s), whereas subjects in their 50s and 60s did not. Across conditions, the variability of stride length, stride time, and single-limb support time was greatest in the 70s. Mediolateral instability increased only for subjects in their 70s in the subtraction by 3s condition. Reduced cognitive function with age makes it difficult for older adults to maintain a normal, rhythmical gait pattern while performing a cognitive task, which may place them at greater risk for falling.
MARINE TURTLE CULTURE - AN OVERVIEW

The general background and present status of this new branch of maricultural science are briefly surveyed, with a description of the only large industrial complex now in existence. Progress in turtle mariculture to the present is summarized and some outstanding scientific problems requiring solution are delineated. The new industry's interface with problems of conservation of wild stocks is discussed.
Plasmonic protection of the hot‐electron energy

In the Letter by K. Kempa, the definitions of two auxiliary constants in Eqs. (10) and (11) were incorrectly given by the author. He now wishes to correct these equations. (© 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
A near-bottom magnetic survey of the Mid-Atlantic Ridge axis at 26°N: Implications for the tectonic evolution of the TAG segment

[1] An extensive deep-tow magnetic survey of the TAG ridge segment on the Mid-Atlantic Ridge reveals new information about the relationship between the magnetic anomaly field and the TAG hydrothermal deposits. Results show the strongest magnetization is located over the neovolcanic axis and asymmetrically toward the western side of the central Brunhes anomaly. A well-defined linear magnetization low is located over the eastern rift valley wall of the TAG segment. The near-bottom data show no direct correlation between this crustal magnetization low and the hydrothermal deposits. The magnetization low is explained by crustal thinning caused by 4 km of horizontal extension along a normal fault. Previous observations and sampling indicate exposures of gabbros and dikes in the eastern rift valley wall, suggesting slip along a normal fault has revealed this crust. Modeling suggests the fault has been active since 0.35 ± 0.1 Ma at a horizontal slip rate of roughly half the spreading rate of 22 km/Myr. The TAG hydrothermal system is located on the hanging wall of this fault within 3 km of its termination. Over the past several hundred thousand years, movement on the detachment fault may have episodically increased the permeability of the hanging wall reactivating the overlying hydrothermal systems. Significant vents like TAG may be typically associated with hanging walls of long-term detachment faults near seafloor spreading centers. This would imply that it is the reactivation of permeability in the hanging wall related to repeated fault movement that controls the longevity of these hydrothermal systems.
Space and the Sea: Strategic Considerations for the Commons

The mediums of space and the sea have many common characteristics. They are both common zones upon which armed forces cannot subsist. Due to their nature, these environments cannot be rendered into national possession. The inherent value of both mediums is to transmit communications. In particular, communications enabled by space-based assets are vital for digital societies. As such, these assets must be protected. However, using weapons to protect them is fraught with political peril. In this regard, it would be wise for spacepower strategists to consult the strategies of classical sea power theory to find important insights. There is a wealth of strategic knowledge to be considered here that would shed light on how to deal with threats in space, including the issue of orbital debris.
Plants Used for Reproductive Health by Nahua Women in Northern Veracruz, Mexico

Plants Used for Reproductive Health by Nahua Women in Northern Veracruz, Mexico. This paper reports the use of medicinal plants by Nahua women in the state of Veracruz, Mexico. It documents the women’s plant knowledge for reproductive purposes, which includes uses such as conception, pregnancy, birth, contraception, menstruation, post-partum, and general reproductive health. The concept of equilibrium is very important in regaining health among the Nahua; consequently, many of the medicinal plants have this as their primary purpose. The introduction of biomedical clinics and hospitals in the region has had a significant effect on the loss of knowledge about medicinal plants. Additionally, the midwives are not taking any new apprentices and laywomen are not passing on their knowledge to future generations. This generational gap contributes to the loss of knowledge about medicinal plants. This research contributes to the study of indigenous ethnobotany by (a) creating a record of the plant knowledge possessed by indigenous women, (b) giving voice to some of their health concerns, (c) indicating how the introduction of biomedicine has affected their plant use, and (d) providing a framework for understanding how marginal peoples around the world respond to the impact that globalization and change has on their health needs and local ethnobotanical knowledge.
Spectrum and stability of compactifications on product manifolds

We study the spectrum and perturbative stability of Freund-Rubin compactifications on M p × M N q , where M N q is itself a product of N q -dimensional Einstein manifolds. The higher-dimensional action has a cosmological term Λ and a q -form flux, which individually wraps each element of the product; the extended dimensions M p can be anti-de Sitter, Minkowski, or de Sitter. We find the masses of every excitation around this background, as well as the conditions under which these solutions are stable. This generalizes previous work on Freund-Rubin vacua, which focused on the N = 1 case, in which a q -form flux wraps a single q -dimensional Einstein manifold. The N = 1 case can have a classical instability when the q -dimensional internal manifold is a product—one of the members of the product wants to shrink while the rest of the manifold expands. Here, we will see that individually wrapping each element of the product with a lower-form flux cures this cycle-collapse instability. The N = 1 case can also have an instability when Λ > 0 and q ≥ 4 to shape-mode perturbations; we find the same instability in compactifications with general N , and show that it even extends to cases where Λ ≤ 0 . On the other hand, when q = 2 or 3, the shape modes are always stable and there is a broad class of AdS and de Sitter vacua that are perturbatively stable to all fluctuations.
Bilateral movement therapy post-stroke: underlying mechanisms and review

Aims Up to 66% of individuals with stroke never regain functional use of their upper extremities. Bilateral movement training (BMT) is a task-specific rehabilitation technique that has recently been investigated for its influence on upper extremity recovery in individuals post-stroke. BMT is thought to affect the hemiparetic upper extremity by a phenomenon referred to as cross education, or the cross transfer effect. Methods This article reviews the theoretical accounts underlying the cross transfer effect and explain the means by which BMT may facilitate recovery of function in the hemiparetic arm. The current research evidence supporting the use of BMT as a therapeutic approach to stroke rehabilitation is discussed, and implications for clinical practice and recommendations for further research are presented. Findings Evidence is emerging that BMT improves impairments and function in people with hemiparesis after stroke. The main limitations of existing research on BMT include small sample sizes, varyin...
The costs and benefits of outpatient surveillance of congenital heart disease after repair

Abstract Regular outpatient re-evaluation in hopes of recognizing treatable post-operative problems is common practice after repair of congenital heart disease. The purpose of this investigation is to audit resource utilization in the care of outpatients after repair of congenital heart disease and to determine what relationship, if any, this utilization may have to active medical management. A chart review of a population of outpatients after surgical repair of secundum or sinus venosus atrial septal defect, surgical or catheter mediated relief of pulmonic stenosis, surgical repair of coarctation of the aorta, repair of tetralogy of Fallot, and Mustard operation for transposition of the great arteries yielded 1252 patient-years of follow-up between 1987 and 1993. Each patient-year was analyzed for management changes and for utilization of outpatient services. Cost of these services was translated to 1994 dollars. More complicated forms of congenital heart disease were associated with more management changes and more outpatient services. Atrial septal defect had no management changes in 254 patient-years of follow-up. Costs per patient-year varied over 6-fold ($237 for atrial septal defect to $1485 for tetralogy of Fallot). Lesion by lesion variation in types of resources utilized in surveillance of repaired congenital heart disease reflected the variation in lesion-specific anticipated late complications. Distribution of costs and management changes were highly skewed within individual forms of repaired heart disease, concentrating 44% of cost and 45% of management changes in the costliest 10% of patient-years within each diagnosis. Outpatient surveillance of repaired congenital heart disease is presently a high technology undertaking, with large expenditures for echocardiography and 24-h ambulatory electrocardiography. Resource allocation decisions that may be mandated in times of austerity must be made in light of the heterogeneity of risk for late complications across and within forms of repaired congenital heart disease.
A comparison of microseismicity induced by gel-proppant-and water-injected hydraulic fractures, Carthage Cotton Valley gas field, East Texas

In May and July, 1997, a consortia of operators and service companies conducted a series of hydraulic fracture imaging tests in the Carthage Cotton Valley gas field of East Texas (Walker, 1997). Microseismic data were collected and processed for six hydraulic fracture treatments in two wells (3 completion intervals per well) (Mayerhofer et al., 2000). One well was completed with gel-proppant treatments in which a viscous crosslink gel was injected to entrain high concentrations of sand proppant into formation. The second well was completed using treated water and very low proppant concentrations (waterfracs). Waterfracs have been shown to be just as effective as the conventional gel-proppant treatments in Cotton Valley reservoirs, but at greatly reduced cost. Mayerhofer and Meehan (1998) suggest two possible reasons why waterfracs are successful: (1) Induced shear displacement along natural and hydraulic fractures results in self-propping (shear dilation enhanced by fracture branching, proppant and spalled rock fragments), and (2) Fracture extension and cleanup is easier to achieve with low-viscosity fluids. With improved source location precision and focal mechanism determination (fracture plane orientation and sense of slip), we have reexamined the Cotton Valley data, comparing the seismicity induced by water and gel-proppant treatments at common depth intervals.more » We have improved the location precision and computed focal mechanism of microearthquakes induced during a series of hydraulic fracture completions within the Cotton Valley formation of East Texas. Conventional gel-proppant treatments and treatments using treated water and very low proppant concentrations (waterfracs) were monitored. Waterfracs have been shown to be just as effective as the conventional gel-proppant treatments in Cotton Valley reservoirs, but at greatly reduced cost (Mayerhofer and Meehan, 1998). Comparison of the seismicity induced by the two treatment types show similar distributions of event locations and focal mechanisms for common depth intervals. We interpret the induced seismicity to be primarily controlled by the natural fracture geometry and independent of treatment design. By implication, we expect the effectiveness of shear-induced fracture propping to be independent of the treatment fluid in Cotton Valley reservoirs.« less
The predoctoral internship: Is current training anachronistic?

The historical context of the predoctoral internship system is contrasted with the current state of graduate training. The internship system emerged because psychology students often acquired insufficient clinical experience during graduate training in the mid-20th century. However, modern graduate training typically involves extensive supervised clinical contact prior to internship. Moreover, traditional internships exact significant financial, psychological, and personal costs from students. The authors conclude with a discussion of recent progress in the internship process, promising alternatives to traditional internship training (i.e., elective internship training, distributed clinical training, and the affiliated internship model), and implications for the profession.
Urethral sleeve sensor: a non-withdrawal method to measure maximum urethral pressure

Introduction and hypothesis This study seeks to evaluate axial variation, comparisons with current technology, performance during dynamic conditions, and patient tolerability of the urethral sleeve sensor (USS) for maximal urethral closure pressure (MUCP) measurements.
Mapping nanoscale wear field by combined atomic force microscopy and digital image correlation techniques

Surface wear of coatings occurring at extremely low loads and in nanocontacts is of great importance for the development and the reliability of structural/functional nanocomponents in micro/nanoelectromechanical systems. To date, appropriate tools for mapping the nanoscale wear of thin coatings are still lacking. In this study, a new method combining atomic force microscopy (AFM) and digital image correlation (DIC) techniques has been developed and applied for the determination and visualization of the nanoscale wear of a gold coating. It has been shown that the initiation and development of nanowear, which is usually difficult to detect directly from AFM topographical images, can be efficiently revealed by monitoring the correlation coefficient change in DIC analysis. A linear relation between the correlation coefficient and the wear depth is found and may be used to quantify the nanowear. The nanowear of gold coating is dominated by material removal without any plastic deformation.
Improved micellar dispersal of dietary lipid by bile acids during replacement therapy in growth hormone-deficient children.

Summary: To date, no information is available on whether human growth hormone (hGH) exerts an influence on digestive processes in man. To test this, we studied the composition of the aqueous (micellar) phase during the digestion of two consecutive meals in growth hormone-deficient individuals and in control subjects, before and after replacement therapy with hGH. Before treatment, the average micellar bile acid concentration was 5.0 ± 0.6 mM (normal adults and controls subjects: 6–15 mM) during the first meal, and 3.5 ± 0.9 mM (normal adults and control subjects 5–10 mM) during the second meal. After 1 year of treatment, the mean micellar bile acid concentration increased to 9.7 ± 1.0 mM (P < 0.02) during the First, and to 7.1 ± 0.3 mM (P < 0.01) during the second meal. Concomitantly with an increased micellar bile acid concentration, micellar lipid increased as well (effect of treatment: (1) fatty acid, first meal 6.3 ± 0.6 mM to 13.0 ± 0.7 mM, P < 0.001; second meal 4.5 ± 1.5 mM to 8.5 ± 0.3 mM, P < 0.05; (2) monoglyceride, as percentage of total fatty acids: first meal 25 ± 10 to 53 ± 7, P < 0.02; second meal 31 ± 7 to 62 ± 6, P 0.02). Short term treatment (10 days) did not have an effect on the concentration of micellar bile acids and lipids in the control subjects. There was no significant difference in the physical state of bile acids and lipids between patients and control subjects before and after treatment. Speculation: The digestion of dietary lipid involves a sequence of important steps: after emulsification, lipolysis generates fatty acids and monoglyceride, which require dispersal by bile acids (above their critical micellar concentration) for transport through the aqueous milieu to the membrane of the enterocyte. The “physiologic micellar concentration” of bile acids in the intestine during a meal for the efficient micellar dispersal of lipid is between 3 and 4 mM. The increase of the intestinal micellar bile acid concentration from borderline to normal adult levels after replacement therapy with growth hormone could be explained as follows. The increased concentrations of bile acids in the intestine after treatment was the result of an increased hepatobiliary secretion of bile acids. This could have been effected by a growth hormone-mediated increase of hepatic bile acid synthesis, or through increased storage capacity of the gallbladder. The latter is probably best explained by a growth hormone-stimulated secretin effect, rather than an effect of gallbladder emptying. Further, increased availability of bile acids for lipid digestion could also result from their improved intestinal conservation (absorption). The clinical implications of the results reported in this study are indirect, but may point towards an interrelationship between hormonal stimulation and certain aspects of hepatobiliary function, which influence digestive processes.
Phytanic acid storage disease (Refsum's disease): Clinical characteristics, pathophysiology and the role of therapeutic apheresis in its management

Phytanic acid storage disease (known also as Refsum's Disease) is caused by inherited defects in the metabolic pathway for phytanic acid, a dietary branched-chain fatty acid. Poorly metabolized phytanic acid accumulates in fatty tissues, including myelin sheaths, and in organs including the liver and kidneys. Over time, affected individuals may develop classical diagnostic features of retinitis pigmentosa, cerebellar ataxia, peripheral polyneuropathy and an elevated protein content in the cerebrospinal fluid. Liver, kidney, and heart disease may also develop. Dietary restriction of phytanic acid is useful in preventing acute attacks and arresting the progression of organ impairment, especially in the peripheral nervous system. Therapeutic plasma exchange has been shown to be particularly useful for rapidly lowering plasma phytanic acid levels during acute attacks and may play a significant role as maintenance therapy as well.
Diamond-Blackfan anemia: “novel” mechanisms—ribosomes and the erythron

[Comment on Flygare et al, page 980, and][1][comment on Choesmel et al, page 1275][2]Important studies by 2 groups have each independently provided compelling evidence implicating impaired ribosome biogenesis in the molecular pathophysiology of the dominantly inherited pure red cell aplasia, Diamond
Myocardial infarction associated with myocardial bridging: case history and review of the literature

A 38-year-old male presented with an acute anterior myocardial infarction. Immediate cardiac catheterization revealed no evidence of angiographically significant atherosclerotic coronary artery disease, but there was a subtotal occlusion of the mid-left anterior descending coronary artery from myocardial muscle bridging. The patient did well with medical management. This review details myocardial bridging and its treatment.
Numerical solution of nonlinear diffraction problems

An adaptive finite element method is developed for solving Maxwell's equations in a nonlinear periodic structure. The medium or computational domain is truncated by a perfect matched layer (PML) technique. Error estimates are established. Numerical examples are provided, which illustrate the efficiency of the method.
Non‐native Ants Are Smaller than Related Native Ants

abstract: I compare the sizes of non‐native and native ants to evaluate how worker size may be related to the ability of a species to invade new habitats. I compare the size of 78 non‐native ant species belonging to 26 genera with the size of native congeneric species; native ants are larger than non‐native ants in 22 of 26 genera. Ants were sorted by genera into fighting and nonfighting groups, based on observations of interspecific interactions with other ant species. In all of the genera with monomorphic worker castes that fight during competition, the non‐native species were smaller than the native species. The genera that engage in combat had a higher frequency of significantly smaller size in non‐native ants. I selected Wasmannia auropunctata for further studies, to compare native and non‐native populations. Specimens of W. auropunctata from non‐native populations were smaller than conspecific counterparts from its native habitat. I consider hypotheses to explain why non‐native ants are smaller in s...
EFFICIENCY WAGES WITH HETEROGENEOUS AGENTS

This paper builds a model of efficiency wages with heterogeneous workers in the economy who differ with respect to their disutility of labor effort. In such an economy, two types of pure strategy symmetric Nash equilibria in firm wage offers can exist: a no-shirking equilibrium in which all workers exert effort while employed and a shirking equilibrium in which within each firm some workers exert effort while others shirk. The type of equilibrium that prevails in the economy depends crucially on the extent of heterogeneity among the workers and the equilibrium rate at which workers join firms from the unemployment pool.
An initial experience and evolution of laparoscopic hepatic resectional surgery

Background The use of minimally invasive procedures has revolutionized modern surgery. Only recently has laparoscopy been introduced for use in hepatic surgery. Methods Patient demographics, tumor characteristics, and outcomes were evaluated for all initial cases of laparoscopic hepatic resection. Results Twenty-one resections were performed in 17 patients; 5 were performed for malignancy, of which 3 had underlying cirrhosis, and the remaining 12 for benign symptomatic disease. Mean patient age was 55.4 (range, 24-82 years). The mean number of lesions was 1.4 (range, 1-5), having an average size of 7.6 cm (range, 2-30 cm). Mean operative time was 2.8 hours (range, 2-5 hours) hours. Most resections involved 1 or more Couinaud segments. Mean blood loss was 288 cc (range, 50-150 cc). Complications included re-operation for hemorrhage (n = 2), biliary leakage (n = 1), and death from hepatic failure (n = 1). Mean length of stay was 2.9 days (range, 1-14). When compared with our series of 100 patients who underwent open hepatic resection for benign tumors, significantly greater means (P Conclusions Laparoscopic hepatic surgery, though complex, can be performed safely and efficaciously. Minimally invasive surgery appears to provide several distinct advantages over traditional open hepatic surgery. However, techniques for the laparoscopic control of bleeding and bile leak remain in their infancy.
The gay bowel syndrome: a common problem of homosexual patients in the Emergency Department.

Sexually transmitted bowel and rectal diseases are common in gay men and are caused by a wide variety of infectious agents. Each of the entities implicated in the gay bowel syndrome is considered separately and epidemiologic considerations responsible for the appearance of such a syndrome are examined. The emergency physician should be prepared to diagnose and initiate treatment of these disorders on a rational basis. Specific practical guidelines for the workup and management of these patients are suggested.
Exponential Energy Decay of the Euler-Bernoulli Beam with Shear Diffusion/Thermal Dissipation

Abstract In this paper, we study the asymptotic behavior of the Euler-Bernoulli elastic beam model coupled a diffusion and/or a dissipation process. We then use a necessary and sufficient condition for a C0-semigroup being exponential stable to show that the energy associated with these models decays exponentially. A remarkable feature of the proof is that the argument does not need a positive gap of eigenvalues of the related operator as before. Therefore, it throws light on the problems in higher space dimensions.
Expression of the 1B isoforms of divalent metal transporter (DMT1) is regulated by interaction of NF-Y with a CCAAT-box element near the transcription start site.

The 1B isoforms of the divalent metal transporter (DMT1) have recently been shown to be regulated transcriptionally via NF-κB but whether other regulatory elements are present on this promoter, however, have not been determined. Accordingly, studies were performed to delineate a minimal promoter region responsible for basal expression of these isoforms of DMT1. Promoter analysis has established that the 1B promoter is a TATA-less promoter containing a common CCAAT-box element conserved in mouse, rat, and human. Using luciferase reporter assays, it was found that mutation of this sequence leads to more than 95% reduction in the basal activity in mouse P19 cells. Using EMSA and ChIP assay, it was confirmed that NF-YA protein subunit can bind specifically to this site. Transfecting these cells with a dominant negative (DN) form of NF-YA leads to ∼60% decrease in luciferase activity and ∼65% decrease in 1B form of mRNA. To determine the location of the CCAAT-box in relation to the transcription start site, 5′ RACE was performed. Results of these studies reveal that the CCAAT-box resides at position −6 to −2 upstream from the transcriptional start site. These data demonstrate that binding of NF-Y to this CCAAT-box domain is responsible for the basal regulation of 1B isoforms of DMT1 mRNA. J. Cell. Physiol. 211: 183–188, 2007. © 2007 Wiley-Liss, Inc.
Regulation of immune reactivity and tolerance by antigen migration and localization: With particular reference to allo- and xenotransplantation

The Specific immunologic non-reactivity to allografts that was first produced in fetal or neonatal mice by Billingham, Brent, and Medawar,1 and, ultimately, in human bone marrow recipients2–5 has remained enigmatic for nearly a half century. Without first understanding this “acquired tolerance,” and, especially, the “acceptance” of organ allografts it is folly to dream of a future that includes xenotransplantation. Beginning in 1992,6 we have developed an explanation for successful transplantation of allografts that, if valid, could guide investigators directly to the objective of clinical xenotransplantation. A central tenet of our proposal is that immune reactivity or non-reactivity (tolerance) to transplanted tissues and organs, to microorganisms, and to all other antigens (including self), is governed by the migration and localization of the antigen.7 Evidence supporting the latter conclusion has been obtained from investigations of the previously unsuspected chimerism that occurs after organ transplantation6,8,9 and from observations following experimental and clinical infections.10–12
Ideal orifice pulse tube refrigerator performance

The recent development of orifice pulse tube refrigerators has raised questions as to what limits their ultimate performance. Using an analogy to the Stirling cycle refrigerator, the efficiency (cooling power per unit input power) of an ideal orifice pulse tube refrigerator is shown to be T1/T0, the ratio of the cold temperature to the hot temperature.
Quantitative Magnetohydrodynamic Modeling of the Solar Transition Region

The transition region (TR) is assumed to be a collision-dominated plasma. The dissipation and transport of energy in such a plasma is accurately described by the classical transport coefficients, which include the electrical and thermal conductivity, viscosity, and thermoelectric tensors. These tensors are anisotropic and are functions of local values of temperature, density, and magnetic field strength. The transport coefficients are valid for all magnetic field strengths and so may be used to study the physics of weakly as well as strongly magnetized regions of the TR. They may be used in an MHD model to obtain a self-consistent, realistic description of the TR. The physics of kinetic processes is included in the MHD model through the transport coefficients. As a first step in studying heating and cooling processes in the TR in a realistic, quantitative manner, a 1.5 dimensional, steady state MHD model with a specified temperature profile is developed. The momentum equation includes the inertial, pressure, magnetic, and gravitational forces. Ohm's law includes the exact expressions for the electrical conductivity and thermoelectric tensors. It is found that the contribution of the dissipation of large-scale electric currents to in situ heating of the TR is negligible, but that thermal energy flowing into the TR from the corona can provide the energy required to heat the TR. The possibility that significant in situ heating of the TR takes place through viscous dissipation or small-scale electric current dissipation such as may occur in current sheets or filaments is discussed, although these processes are not described by the model. The importance of thermoelectric and electron pressure gradient effects in Ohm's law, and in determining the electron heat flux, is demonstrated. Results of the model suggest that the force-free approximation is not valid over most of the TR. Justification for assuming that the TR is collision dominated is presented. In particular, a self-consistent calculation of the ratio of the electric field parallel to the magnetic field to the Dreicer electric field yields a value 10-3, which suggests that anomalous transport processes are not important. The necessity of using a realistic description of transport processes in modeling heating mechanisms in the solar atmosphere is stressed.
Combinatorial screening of osteoblast response to 3D calcium phosphate/poly(ε-caprolactone) scaffolds using gradients and arrays.

There is a need for combinatorial and high-throughput methods for screening cell–biomaterial interactions to maximize tissue generation in scaffolds. Current methods employ a flat two-dimensional (2D) format even though three-dimensional (3D) scaffolds are more representative of the tissue environment in vivo and cells are responsive to topographical differences of 2D substrates and 3D scaffolds. Thus, combinatorial libraries of 3D porous scaffolds were developed and used to screen the effect of nano-amorphous calcium phosphate (nACP) particles on osteoblast response. Increasing nACP content in poly(e-caprolactone) (PCL) scaffolds promoted osteoblast adhesion and proliferation. The nACP-containing scaffolds released calcium and phosphate ions which are known to activate osteoblast function. Scaffold libraries were fabricated in two formats, gradients and arrays, and the magnitude of the effect of nACP on osteoblast proliferation was greater for arrays than gradients. The enhanced response in arrays can be explained by differences in cell culture designs, diffusional effects and differences in the ratio of “scaffold mass to culture medium”. These results introduce a gradient library approach for screening large pore 3D scaffolds and demonstrate that inclusion of the nACP particles enhances osteoblast proliferation in 3D scaffolds. Further, comparison of gradients and arrays suggests that gradients were more sensitive for detecting effects of scaffold composition on cell adhesion (short time points, 1 day) whereas arrays were more sensitive at detecting effects on cell proliferation (longer time points, 14 day).