cssi/SciSciGPT-SciSciNet huggingface dataset:
Urea Synthesis and Excretion in Aedes aegypti Mosquitoes Are Regulated by a Unique Cross-Talk Mechanism

Aedes aegypti mosquitoes do not have a typical functional urea cycle for ammonia disposal such as the one present in most terrestrial vertebrates. However, they can synthesize urea by two different pathways, argininolysis and uricolysis. We investigated how formation of urea by these two pathways is regulated in females of A. aegypti. The expression of arginase (AR) and urate oxidase (UO), either separately or simultaneously (ARUO) was silenced by RNAi. The amounts of several nitrogen compounds were quantified in excreta using mass spectrometry. Injection of mosquitoes with either dsRNA-AR or dsRNA-UO significantly decreased the expressions of AR or UO in the fat body (FB) and Malpighian tubules (MT). Surprisingly, the expression level of AR was increased when UO was silenced and vice versa, suggesting a cross-talk regulation between pathways. In agreement with these data, the amount of urea measured 48 h after blood feeding remained unchanged in those mosquitoes injected with dsRNA-AR or dsRNA-UO. However, allantoin significantly increased in the excreta of dsRNA-AR-injected females. The knockdown of ARUO mainly led to a decrease in urea and allantoin excretion, and an increase in arginine excretion. In addition, dsRNA-AR-injected mosquitoes treated with a specific nitric oxide synthase inhibitor showed an increase of UO expression in FB and MT and a significant increase in the excretion of nitrogen compounds. Interestingly, both a temporary delay in the digestion of a blood meal and a significant reduction in the expression of several genes involved in ammonia metabolism were observed in dsRNA-AR, UO or ARUO-injected females. These results reveal that urea synthesis and excretion in A. aegypti are tightly regulated by a unique cross-talk signaling mechanism. This process allows blood-fed mosquitoes to regulate the synthesis and/or excretion of nitrogen waste products, and avoid toxic effects that could result from a lethal concentration of ammonia in their tissues.
A higher order finite element for laminated beams

Abstract This article presents the derivation of a new finite element model for laminated composite beams. The model includes sufficient degrees of freedom to allow the cross-sections of each lamina to deform into a shape which includes up through cubic terms in the thickness coordinate. The element does not require additional axial or transverse degrees of freedom beyond those necessary for a single lamina. The shape functions assure compatability of deformation between laminae. The element consequently admits shear deformation up through quadratic terms for each lamina but not interfacial slip or delamination. Numerical results are compared with other theoretical and experimental investigations.
Utilizing Context In Computer Vision By Confidence Modification

Abstract The analysis of images derived from a "real" scene often involves applying a rule-based structure leading to object detection, recognition and object relationships. A rule consists of a set of conditions whose satisfaction triggers the rule. These conditions are based on domain knowledge of image characteristics, inferred knowledge, and scene context. Firing a rule leads to conclusions with assigned confidences. Frequently, additional scene context knowledge can have a significant effect on the final conclusion but is excluded because its form varies from scene to scene, and its unavailability in the main rule base would prevent rule application.This paper utilizes context by altering confidences associated with conclusions of specific rules. Uncertainty computations for conclusions of rules to which the contextual information applies would be effected. For each rule, Rj, of the main rule structure, a context factor Cj with values over [-1,1], is defined. If Cj =0, no relevant context information is present; if Cj>0, there is a degree of support; if Cj<0, a conflict with the conclusion is implied. If P(THEN,j) represents the certainty in the conclusion of rule R j , then modify this as P'(THEN,j)=f'[P(THEN,j), Cj], where f is selected to satisfy conditions imposed on the confidence and context information.
Nuclear localization signal-independent and importin/karyopherin-independent nuclear import of β-catenin

Abstract Background: Control of the nuclear localization of specific proteins is an important mechanism for regulating many signal transduction pathways. Upon activation of the Wnt signaling pathway, β -catenin localizes into the nucleus and interacts with TCF/LEF-1 (T-cell factor/lymphocyte enhancer factor-1) transcription factors, triggering activation of downstream genes. The role of regulated nuclear localization in β -catenin signaling is still unclear. β -catenin has no nuclear localization sequence (NLS). Although it has been reported that β -catenin can piggyback into the nucleus by binding to TCF/LEF-1, there is evidence that its import is independent of TCF/LEF-1 in vivo . Therefore, the mechanism for β -catenin nuclear localization remains to be established. Results: We have analyzed β -catenin nuclear import in an in vitro assay using permeabilized cells. β -catenin docks specifically onto the nuclear envelope in the absence of other cytosolic factors. Docking is not inhibited by an NLS peptide and does not require importins/karyopherins, the receptors for classical NLS substrates. Rather, docking is specifically competed by importin- β / β -karyopherin, indicating that β -catenin and importin- β / β -karyopherin both interact with common nuclear pore components. Nuclear translocation of β -catenin is energy dependent and is inhibited by nonhydrolyzable GTP analogs and by a dominant-negative mutant form of the Ran GTPase. Cytosol preparations contain inhibitory activities for β -catenin import that are distinct from the competition by importin- β / β -karyopherin and may be involved in the physiological regulation of the pathway. Conclusions: β -catenin is imported into the nucleus by binding directly to the nuclear pore machinery, similar to importin- β / β -karyopherin or other importin- β -like import factors, such as transportin. These findings provide an explanation for how β -catenin localizes to the nucleus without an NLS and independently of its interaction with TCF/LEF-1. This is a new and unusual mechanism for the nuclear import of a signal transduction protein. The lack of β -catenin import activity in the presence of normal cytosol suggests that its import may be regulated by upstream events in the Wnt signaling pathway.
Primary prevention and foster care

Abstract The purpose of this paper is to develop a systematic connection between primary prevention and foster care so that foster care professionals and parents might make use of the large existing technology to facilitate the healthy development of children in the foster care system. Definitions of terms are provided; outcome research in foster care is reviewed briefly so as to identify specific locations where primary prevention methods might be most usefully employed. Then specific methods are suggested to link the primary prevention model to foster care services. Finally, a case study is given to illustrate the integration of various primary prevention methods.
Theory of the fourfold induced-torque anisotropy in potassium

Induced-torque anisotropies observed in single-crystal spheres of potassium prove that the Fermi surface is multiply connected. Cyclotron orbits which intersect heterodyne gaps created by the charge-density-wave broken symmetry lead to an anisotropic Hall effect having longitudinal components. Thereby the theoretical induced torque (in a 360\ifmmode^\circ\else\textdegree\fi{} magnet rotation) has four evenly spaced minima and four maxima with a staggered spacing. The maxima grow almost $\ensuremath{\sim}{H}^{2}$ and can be 30 times higher than the minima. All such features have been observed. (Details depend on crystal growth and orientation.) All are impossible in a spherical crystal with a simply connected Fermi surface.
The Relative Rates of Reaction of Sodium with Some Polynuclear Hydrocarbons

The Na-Hg amalgam consisting of 40 weight percent sodium which is liquid at room temperature readily metalates all polynuclear hydrocarbons in the presence of active ether solvents. This system made possible a determination of the relative rates of addition of sodium to polycyclic hydrocarbons. In the present study, various hydrocarbons reacted with decreasing rates as follows: o-terphenyl ≅ p-terphenyl ≫ anthracene > naphthalene > biphenyl > phenanthrene > m-terphenyl. At equilibrium, the gram atoms of sodium consumed per mole of hydrocarbon by the seven polycyclic compounds listed above in the order given was: 2.0; 2.0; 1.8; 1.0; 0.4; 1.24; and 1.0.
Children's strategies for coping with stress: Blunting and monitoring

The present study examined children's suggestions for coping with uncontrollable stress, from the perspective of the monitoring/blunting distinction proposed by Miller (1987). Children in the first through sixth grades heard stories depicting four stressful situations that afforded little opportunity for control. Children's coping suggestions were classified as blunting (including reappraisal, cognitive distraction, and behavioral distraction), monitoring, or seeking support. Overall, blunting strategies were mentioned most often, followed by monitoring, and seeking support. A grade-level increase in blunting suggestions was found, and this developmental pattern was identical for reappraisal, cognitive distraction, and behavioral distraction. No grade-level differences were observed for monitoring or support. Situational differences in coping suggestions were explored, and there was mixed evidence of cross-situational consistency in coping style.
Gas Chromatography Analysis of Diphenyl-Diacetylene Liquid Crystals

Abstract A gas chromatography method is used to investigate the purity of dialkyl-diphenyl-diacetylene liquid crystal components and at the same time identify the structure and concentration of the major impurities.
An asymptotic method for free convection past a vertical plate

Das Problem der freien Stromung an einer ungleichmassig erhitzten Wand wird auf die Berechnung einer Reihe von Funktionen zuruckgefuhrt, von denen jede einer linearen Differentialgleichung mit konstanten Koeffizienten genugt.
Study on Air Ingress Mitigation Methods in the Very High Temperature Gas Cooled Reactor (VHTR)

An air-ingress accident followed by a pipe break is considered as a critical event for a very high temperature gas-cooled reactor (VHTR). Following helium depressurization, it is anticipated that unless countermeasures are taken, air will enter the core through the break leading to oxidation of the in-core graphite structure. Thus, without mitigation features, this accident might lead to severe exothermic chemical reactions of graphite and oxygen. Under extreme circumstances, a loss of core structural integrity may occur along with excessive release of radiological inventory. Idaho National Laboratory under the auspices of the U.S. Department of Energy is performing research and development (RD (2) preventing local stress concentration in the supporter; (3) preventing graphite oxidation; (4) preventing air ingress; (5) preventing density gradient driven flow; (4) preventing fluid density gradient; (5) preventing fluid temperature gradient; (6) preventing high temperature. Based on the basic concepts listed above, various air-ingress mitigation methods are proposed in this study. Among them, the following two mitigation ideas are extensively investigated using computational fluid dynamic codes (CFD): (1) helium injection in the lower plenum, and (2) reactor enclosure opened at the bottom. The main idea of the helium injection method is to replace air in the core and the lower plenum upper part by buoyancy force. This method reduces graphite oxidation damage in the severe locations of the reactor inside. To validate this method, CFD simulations are addressed here. A simple 2-D CFD model is developed based on the GT-MHR 600MWt design. The simulation results showed that the helium replace the air flow into the core and significantly reduce the air concentration in the core and bottom reflector potentially protecting oxidation damage. According to the simulation results, even small helium flow was sufficient to remove air in the core, mitigating the air-ingress successfully. The idea of the reactor enclosure with an opening at the bottom changes overall air-ingress mechanism from natural convection to molecular diffusion. This method can be applied to the current system by some design modification of the reactor cavity. To validate this concept, this study also uses CFD simulations based on the simplified 2-D geometry. The simulation results showed that the enclosure open at the bottom can successfully mitigate air-ingress into the reactor even after on-set natural circulation occurs.« less
Response to Haemophilus influenzae type bconjugate vaccine in chronically ill premature infants

Twenty-two premature infants with chronic lung disease (median gestational age 28 weeks) received polyribosylribitol phosphate-outer membrane protein conjugate Haemophilus vaccine at 2 and 4 months of chronologic age. The proportions with antibodies to polyribosylribitol phosphate at levels >1 μ g/ml after doses 1 and 2 were 27% and 55%; geometric mean titers were 0.43 and 0.73 μ g/ml, significantly lower than values for term infants.
Optimizing the informed consent process with elderly people.

While the avowed purpose of informed consent is to inform, this objective has been shown not to have been met in many situations, particularly with elderly people. The assumption that a single methodology for informed consent would suffice for all people may underlie this failure. The view of consent within a simplistic paradigm of how a person seeks, obtains, and assimilates information in order to make a decision needs to be expanded. This article presents a conceptualization of the informing process and adaptations of the consent process that may help to more completely fulfill the primary goal of informed consent.
Educational preferences and outcomes from suicide prevention training in the Veterans Health Administration: one-year follow-up with healthcare employees in Upstate New York.

ABSTRACTThis study identifies training outcomes and educational preferences of employees who work within the Veterans Health Administration (VHA). Using a longitudinal pre- postsurvey design, 71 employees from one geographic region of VHA healthcare facilities participated in an evaluation of a brief standardized gatekeeper program and a needs assessment on training preferences for suicide and suicide prevention. Results indicate significant differences in knowledge and self-efficacy from pre to post (p < 0.001), although only self-efficacy remained significant at 1 year follow-up, (M = 3.01; SD = 0.87) as compared to pretraining (M = 2.50, SD = 1.05) (t = −5.64, p < 0.001). At post-training, 90% of the participants were willing to learn more about suicide, with 88% willing to spend more than 1 hour in future training activities on more advanced topics. This training program can increase the knowledge and abilities of VHA staff to engage, identify, and refer veterans at risk for suicide to appropriate care.
Comparison of indocyanine green fluorescent angiography to digital subtraction angiography in brain arteriovenous malformation surgery

The potential utility of intraoperative microscope-integrated indocyanine green (ICG) fluorescence angiography in the surgery of brain arteriovenous malformations (AVMs) and evaluation of the completeness of resection is debatable. Postoperative catheter angiography is considered the gold standard. We evaluated the value of ICG and intraoperative catheter angiography in this setting. Between January 2009 and July 2013, 37 patients with brain AVMs underwent surgical resection of their vascular lesions. ICG videoangiography and an intraoperative catheter angiography were performed in 32 cases, and a routine postoperative angiogram was performed within 48 h to 2 weeks after surgery. The usefulness of ICG findings and the ability to confirm total resection and to identify residual nidus or persistent shunt were assessed and compared to intraoperative and postoperative digital subtraction angiography, respectively. There were 7 grade 1, 11 grade 2, 11 grade 3 and 3 grade 4 Spetzler-Martin classification AVMs. ICG angiography helped to distinguish AVM vessels in 26 patients. In 31 patients, it demonstrated that there was no residual shunting. In one patient, a residual AVM was identified and further resected. Intraoperative catheter angiography detected two additional small residuals that were missed by ICG angiography, both deep in the surgical cavity. Further resection of the AVM was performed, and total resection was confirmed by a repeat intraoperative angiogram. Postoperative angiography in a patient with a grade 4 lesion revealed one additional small deep residual AVM nidus with persistent late shunting missed on both ICG and intraoperative angiography. Overall ICG angiography missed three out of four residual AVMs after initial resection, while the intraoperative angiogram missed one. Although ICG angiography is a helpful adjunct in the surgery of some brain AVMs, it’s yield in detecting residual AVM nidus or shunt is low, especially for deep-seated lesions and higher grade AVMs. ICG angiography should not be used as a sole and/or reliable technique. High-resolution postoperative angiography must be performed in brain AVM surgery and remains the best test to confidently confirm complete AVM resection.
Consuming Andean Televisions

This article follows consumers from Otavalo, Ecuador through narratives of devilish eating, jokes, and family gatherings in order to focus on a general problem: how a dispersed Andean indigenous pe...
Pathophysiology of Valvular Aortic Stenois in the Elderly

Aortic stenosis in the elderly is related to calcification of either a bicuspid valve or a morphologically normal tricuspid valve. There is increasing evidence that factors relating to atherosclerosis are involved in valvular calcification and that it is an actively regulated process rather than a degenerative one. With severe aortic stenosis left ventricular hypertrophy occurs, decreasing wall stress and supporting the left ventricular ejection fraction. However, with pathologic hypertrophy there is a dropout of myocardial cells, subendocardial ischemia, and fibrosis. Eventually, symptoms of angina, non-Q wave myocardial infarction, exertional syncope, and heart failure occur. Once symptoms begin, the prognosis is poor, with sudden death occurring in about one third of patients who die. In the elderly, symptoms can be recognized very late in the course of the disease since they can be attributed to other problems and since the elderly patient may have reduced physical activity to a minimum. The more comorbidities that exist, the greater the risk of valve replacement. Symptomatic patients with severe aortic stenosis even over age 80 can be operated upon with a relatively low mortality and morbidity. In patients over age 80, prolongation of life for any meaningful length of time is not as important as relief of symptoms and improvement in the quality of life. Thus, it is unlikely that any truly asymptomatic patient over age 80, even with severe aortic stenosis, should be sent to surgery.
Best ever athlete

Who was the best athlete the modern world has ever seen? Must we refer to ancient history to decide?Joseph Hilbe looks at the contenders.
Turnover from mollusk-dominated Depauperate Zone (late Ordovician) to brachiopod-dominated (early Silurian) faunas in central North America

The Depauperate Zone from the base of the Ordovician (Katian) Maquoketa shale in Dubuque, Iowa, features a range of diminutive infaunal, epifaunal, nektonic and planktonic members with multiple growth stages. Fossils are preserved as phosphatized internal molds. In rare cases, shell replacement conserves growth lines. Sixteen species were recovered, including three-dimensional graptolites (Rectograptus peosta). The bivalves Palaeoneilo fecunda and Nuculites neglectus are most abundant, but the orthid brachiopod Plaesiomys subquadrata also is common. Bivariate analyses were conducted on the bivalve and brachiopod species, two gastropods (Liospira micula and Cyrtolites carinatus), a reputed sponge (Hindia sphaeroidalis) and the graptolite. All mollusks follow an isometric growth pattern and the same is especially characteristic of the orthid brachiopod. Winnowing by waves or bottom currents was minimal. Pene-contemporaneous replacement of fine details was due to concentrations of P2O5 in seawater intermitte...
ADAMTS-13 Metalloprotease Interacts with the Endothelial Cell-derived Ultra-large von Willebrand Factor

Thrombotic thrombocytopenic purpura is caused by congenital or acquired deficiency of ADAMTS-13, a metalloprotease that cleaves the endothelium-derived ultra-large multimers of von Willebrand factor (ULVWF). The proteolysis converts hyper-reactive and thrombogenic ULVWF into smaller and less adhesive plasma forms. Activity of ADAMTS-13 is usually measured in a static system under non-physiological conditions that require protein denaturation and prolonged incubation. We have demonstrated previously that ULVWF multimers, upon release from endothelial cells, form plateletdecorated string-like structures that are rapidly cleaved by ADAMTS-13. Here we report the direct interaction between ADAMTS-13 and VWF under both static and flowing conditions. ADAMTS-13-coated beads adhered to both immobilized VWF and ULVWF strings presented by stimulated endothelial cells. These beads adhered to VWF under both venous (2.5 dynes/cm2) and arterial (30 dynes/cm2) shear stresses. We then demonstrated that ADAMTS-13 beads adhered to immobilized recombinant VWF-A1 and -A3 domains, but soluble metalloprotease bound preferentially to the A3 domain, suggesting that the VWF A3 domain may be the primary docking site for the metalloprotease. We suggest that tensile stresses imposed by fluid shear stretch endothelial bound ULVWF multimers to expose binding sites within the A domains for circulating ADAMTS-13. The bound enzyme then cleaves within the A2 domain that lies in close proximity and releases smaller VWF multimers into the plasma. Once released, these cleaved VWF fragments become inaccessible for the metalloprotease to prevent further cleavage.
Hf2.64Zr0.36Te4 and MIxZr3Te4 (MI = Na, K, Rb, Cs), new compounds of the Nb3Te4-structure type

Abstract The synthesis of the pseudo-binary telluride Hf2.64Zr0.36Te4 and new ternary tellurides MIx)Zr3Te4 (MIx = Na, K, Rb, Cs; 0.2 a = 10.892(1) A , c = 3.9084(5) A for Hf 2.64 Zr 0.36 Te 4 , a = 11.009(2) A , c = 3.9374(8) A for Na 0.42 Zr 3 Te 4 ; a = 11.034(2) A , c = 3.9340(6) A for K 0.25 Zr 3 Te 4 ; a = 11.061(1) A , c = 3.9278(5) A for Rb 0.29 Zr 3 Te 4 ; and a = 11.100(1) A , c = 3.9188 (5) A for Cs 0.35 Zr 3 Te 4 . All compounds adopt the Nb3Te4 structure type, which is built up by edge and face sharing of distorted MTe6 (M = Zr, Hf) octahedra. MTe6 octahedra share edges to form zigzag M-M chains running along the c-axis. Distorted MTe6 octahedra in these zigzag metal-metal chains are further condensed by sharing faces. MM bond distances in these tellurides are quite a bit longer (≈0.5 A) than those of Nb3Te4, as expected for compounds with fewer electrons for metal-metal bonding. Large hexagonal channels are partially occupied by alkali cations in the ternary zirconium tellurides. Four-probe single crystal resistivity measurements (77–300 K) show these ternary tellurides to be metallic with resistivities of 1.2 × 10 −3 Ω- cm (Na0.42Zr3Te4), 2.8 × 10 −4 Ω- cm (K0.25Zr3Te4), 4.9 × 10 −4 Ω- cm (Rb0.29Zr3Te4), and 1.7 × 10 −4 Ω- cm (Cs0.35Zr3Te4) at 273 K. Hf2.64Zr0.36Te4 also shows metallic behavior.
Percutaneous Native Renal Biopsy: Comparison of a 1.2-mm Spring-driven System With a Traditional 2-mm Hand-driven System

Over the last few years spring-driven mechanical biopsy guns have been introduced for performing renal biopsies. There has been little research done comparing these guns with traditional hand-driven needles in performing biopsies of native kidneys. We wished to compare our experience with the two needle types. We studied retrospectively the results and complication rates of 155 native kidney biopsies. Sixty-nine were performed with hand-driven 14-gauge needles and eighty-six with 18-gauge, spring-driven biopsy guns. Sufficient tissue for diagnosis was obtained in 96% of cases in the hand-driven group compared with 99% in the biopsy gun group ( P = NS). Complications occurred in six cases in the hand-driven group compared with one case in the biopsy gun group ( P = 0.02). As expected, the reported number of glomeruli per core in the 14-gauge cores was greater than in the 18-gauge cores (16.5 v 6.2, P
Invasive lobular carcinoma of the breast: local recurrence after breast-conserving therapy by subtype approximation and surgical margin

Invasive lobular carcinoma (ILC) typically presents at a later stage than invasive ductal carcinoma (IDC) and poses unique radiographic and surgical challenges. However, current principles of breast-conserving therapy (BCT) do not distinguish between histologic subtypes, raising uncertainty about the optimal approach for patients with ILC. We studied 998 BCT patients from 1998–2007, comprised 74 % IDC, 8 % ILC, and 18 % with mixed ILC/IDC. In light of recent guidelines addressing surgical margins, specimens were assessed for margin width and biologic subtype. The Kaplan–Meier method and Cox proportional hazards models were used to analyze effects of patient and disease characteristics on local recurrence (LR). At a median of 119 months, 45 patients had an isolated LR. 10-year LR was 5.5 % for patients with IDC, 4.4 % for ILC, and 1.2 % for mixed histology (p = 0.08). The majority of ILC cases had luminal A biologic subtype (91.1 %), and analysis among all luminal A cases revealed 10-year LR of 2.6 % for IDC, 3.4 % for ILC, and 0 % for mixed tumors (p = 0.12). Patients with ILC were more likely to have initially positive surgical margins (45.0 vs 17.5 %; p < 0.001) resulting in more frequent re-excision (57.1 % vs 40.4 %; p = 0.02), though final margins were similar between ILC and IDC (p = 0.88). No LR was observed among ILC or mixed histology patients with margins <2 mm (n = 28). On multivariate analysis, histologic subtype was not associated with LR (p = 0.52). Modern approaches confer similarly favorable LR rates for ILC, IDC, and mixed histology breast cancers despite inherent histologic differences. Patients with ILC did not require more extensive surgical margins than those with IDC.
PHOSPHORUS AND ARSENIC UPTAKE BY CORN, WHEAT AND SOYBEAN FROM BROILER LITTER ASH AND EGG LAYER MANURE ASH

Poultry litter is being incinerated to reduce excess litter, and the ash from incineration is being used as fertilizer. The objective of this study was to compare the availability of phosphorus (P) from broiler litter ash (BLA), egg layer manure ash (ELMA) and calcium phosphate for corn, wheat and soybean. Other elements such as arsenic are also concentrated in the ashed litter. Calcium phosphate, BLA and ELMA were mixed with soil at 40 and 80 mg P kg−1. Crops were grown for about six weeks. Biomass and phosphorus concentrations were highest for plants grown on the calcium phosphate treatments. At the highest phosphorus rate, phosphorus concentrations were 1135,963 and 939 mg kg−1 in corn shoot for calcium phosphate, ELMA and BLA, respectively. Arsenic concentrations for plants grown on ash treatment were similar to the control. Results from this study indicated that phosphorus in the ash was not readily available for crop uptake.
Analysis of Hold Time Models for Total Flooding Clean Extinguishing Agents

This study documents the experimental results of a research program designed to evaluate the validity of the widely published hold time prediction models found in NFPA 2001, Annex C and ISO 14520-1, Annex E. The models discussed in these standards obtain a measure of the equivalent leakage area, which, when coupled with ‘worst case’ assumptions, can be used to determine the minimum hold time. Three hold time prediction theories are adopted from these standards for validation; a wide descending interface model as implemented in ISO 14520-1 and two sharp descending interface models from the 2004 and 2008 publications of NFPA 2001. The experimental program is comprised of 15 tests conducted in a 103 m3 test enclosure. Three commercially available clean agents are selected to span a wide range of agent vapor densities including FK-5-1-12, HFC-125, and IG-541. A series of holes were drilled through enclosure boundaries at upper and lower elevations which were opened or closed as a means of regulating the amount of leakage area for any given test. Vertical profiles of agent concentration and ambient pressure are used to evaluate the agent concentration distribution, rates of agent draining, and the effective lower leakage fraction. A non-dimensional hold time is used to compare experimental results involving differing agent types and leakage areas. Results show that empirical values of the hold time are up to 50% longer than the theoretical hold time predictions when evaluated as the time to reduce the agent concentration to half its initial value. When evaluated as a 15% drop in concentration the model validity is significantly reduced. Under this condition, empirical hold time values are up to 50% shorter than the predictions of the sharp descending interface models and up to 100% longer than the wide descending interface model.
The cell cycle in Escherichia coli B/r☆

Abstract Cell division and DNA synthesis were measured in synchronous cultures of E. coll B/r growing in glucose minimal medium at 37 °. The kinetic curves were analysed in order to find the variability of replication initiation, termination, and cell division events during the cell cycle. It is inferred that under the conditions used, cells begin to divide 17 min ( D 0 = minimum D-period) after each termination of chromosome replication with a constant probability per unit of time (half-life = 4·5–6 min). This randomness produces an asymmetric frequency distribution of D -periods, similar but mirror-symmetric frequency distributions of initiation and termination periods, a symmetric, non-Gaussian distribution of interdivision intervals, and complex kinetic changes in the rate of DNA synthesis as a function of cell age. The results suggest that replication and division are precisely controlled with respect to mass accumulation, and the apparent variability of cell cycle events would only result from the use of the time of cell separation as a reference point for the definition of cell age rather than initiation or termination of replication.
Thermal history effects on electrical relaxation and conductivity for potassium silicate glass with low alkali concentrations

Electrical response measurements from 10 Hz to 100 kHz between 120 and 540 C were made on potassium-silicate glasses with alkali oxide contents of 2, 3, 5 and 10 mol percent. Low alkali content glasses were chosen in order to try to reduce the Coulombic interactions between alkali ions to the point that frozen structural effects from the glass could be observed. Conductivity and electrical relaxation responses for both annealed and quenched glasses of the same composition were compared. Lower DC conductivity (sigma(sub DC)) activation energies were measured for the quenched compared to the annealed glasses. The two glasses with the lowest alkali contents exhibited a non-Arrhenius concave up curvature in the log(sigma(sub DC)) against 1/T plots, which decreased upon quenching. A sharp decrease in sigma(sub DC) was observed for glasses containing K2O concentrations of 5 mol percent or less. The log modulus loss peak (M'') maximum frequency plots against 1/T all showed Arrhenius behavior for both annealed and quenched samples. The activation energies for these plots closely agreed with the sigma(sub DC) activation energies. A sharp increase in activation energy was observed for both series as the potassium oxide concentration decreased. Changes in the electrical response are attributed to structural effects due to different alkali concentrations. Differences between the annealed and quenched response are linked to a change in the distribution of activation energies (DAE).
Lessons Learned from Herbal Medicinal Products: The Example of St. John’s Wort⊥

The example of St. John’s wort offers convincing evidence for the concept that modern methods of pharmacological and phytochemical research are effective in advancing the development of traditional herbal remedies. As a consequence of these efforts, it is known today that several compounds from different structural groups and with different mechanisms of action seem to be responsible for the observed antidepressant efficacy of St. John’s Wort. Co-effectors in the extract improve the bioavailability of active constituents such as hypericin (1) (pharmacokinetic synergy). Unwanted side effects are preventable without remarkable loss of activity when the responsible constituent(s) are carefully removed during the extraction process, as demonstrated for hyperforin (3), which is responsible for the induction of cytochrome P450 (CYP)-metabolizing enzymes (CYP3A4, in particular). On the basis of our findings, it is likely that positive interactions between single compounds occur more frequently in traditionally u...
Leadership role profile and job satisfaction of restaurant general managers.

Leadership roles (using Quinn's Competing Values Framework) utilized by managers of fast-casual, casual, and quick-service restaurants were compared for differences. Fast-casual managers utilize the greatest balance of leadership roles and are the most effective according to Quinn's model. Quick-service managers have the highest level of job satisfaction but utilize a less balanced and complete leadership role profile than other managers. No relationship was found between the use of leadership roles and job satisfaction, intent to stay, or demographic characteristics. Restaurant general managers tend to use the less complex and less risky leadership roles.
Esophageal epithelial cell interaction with synthetic and natural scaffolds for tissue engineering

As an initial step towards a tissue-engineered esophagus, rat esophageal epithelial cells (REEC) were isolated and characterized for epithelial identity, adhesion protein preference, and in vitro interaction with natural and synthetic scaffolds. The scaffolds consisted of AlloDerm (LifeCell Corporation, Branchburg, NJ), poly(L-lactic acid) (PLLA), poly(lactic-co-glycolic) acid (75:25) (PLGA75), poly(lactic-co-glycolic) acid (50:50) (PLGA50), and polycaprolactone/poly(L-lactic acid) (50:50) (PCL/PLLA). Various factors-including calcium concentration, scaffold composition, and pore size--were evaluated for their influence on epithelial growth and differentiation. By day 18, keratinocytes seeded on AlloDerm cultured under high Ca(++) (1.5mm) conditions showed a proliferating basal cell layer, epithelial stratification (5--6 layers) and a thick keratin layer. The synthetic scaffolds (PLGA, PLLA, PCL/PLLA) also showed complete surface coverage, regions of proliferating basal cells, and evidence of stratification (2--3 layers) and keratinization. The highly porous nature of the synthetic scaffolds, however, limited the formation of a continuous epithelial layer and resulted in a lack of overall spatially-defined differentiation. In conclusion, rat esophageal epithelial cells were successfully isolated and characterized, with cells seeded on AlloDerm showing superior epithelial organization and stratification compared to synthetic scaffolds. Modification of the synthetic scaffold's surface properties and pore size may be necessary to mimic epithelial behavior on natural scaffolds.
Serological Evidence on the Relationships of the Musk Ox

Opinions concerning the relationships of the musk ox to other members of the family Bovidae are varied and contradictory. Flower and Lydekker (1891) stated that “this genus is generally considered to be a connecting link between the Caprine and Bovine sections, but should rather be regarded as an aberrant type of the former.” Yet the idea, suggested indeed by the very name Ovibos , that the genus forms a link betwen sheep and cattle has never completely disappeared ( cf . Glover, 1953). The genus received monographic treatment by Allen (1913) who, largely on the basis of the morphology of the Recent forms, concluded that “ Ovibos finds its nearest ally among living mammals in the genus Bison .” This view has been largely followed by mammalogists ( cf . Anthony, 1928; Seton, 1929). On the other hand, paleontologists have concluded that Ovibos is most closely allied to goats. Thus Simpson (1945) placed Ovibos in the subfamily Caprinae; Miller and Kellogg (1955) followed his usage in doing so. Seemingly paleontologists have been influenced to this view by study of related Old World genera, especially Urmiatherium, Parurmiatherium, Criotherium and Plesiaddax , which combine to bridge the gap between ovibovine and caprine characteristics (Pocock, 1918; Sickenberg, 1933; Bohlin, 1935; Schwarz, 1937; Pilgrim, 1939). That the controversy is still current is attested by Tome XVII of Grasse, Traite de Zoologie. One contributor to this volume on mammals places the musk ox in the subfamily Bovinae (Frechkop, 1955) while a few pages later another contributor classifies it in the subfamily Caprinae (Lavocat, 1955). This diversity of practice in one volume lends point to the comment by Pilgrim (1939): “ Ovibos has been bandied about like a shuttlecock between the two groups of the oxen and the sheep.” When morphology …
Results of FDA’s First Interlaboratory Computational Study of a Nozzle with a Sudden Contraction and Conical Diffuser

The U.S. Food and Drug Administration recently hosted an interlaboratory study to assess the suitability and methodology of computational fluid dynamics (CFD) for demonstrating medical device safety in regulatory submissions. The benchmark study was performed in a generic medical device consisting of a 0.012 m diameter cylindrical nozzle with a sudden contraction and 10° conical diffuser, on either side of a 0.04 m long, 0.004 m diameter throat. Results from 28 simulations from around the world were compared to planar particle image velocimetry (PIV) measurements performed at three laboratories. Five flow rates were chosen that produced laminar, transitional, and turbulent regimes. In general, the CFD results showed modest agreement in global and local flow behaviors. However, all CFD data sets contained wide degrees of velocity variation in comparison to experiment and with each other, much of which could be attributed to the turbulence models used. Some of the velocity discrepancies in the sixteen three dimensional (3D) simulations resulted from substantial flow asymmetries within and downstream of the conical diffuser. Large differences in velocity symmetry were found even when using the same code and many of the same simulation parameters. In contrast, no velocity asymmetries of the same magnitude were observed in any of the planar PIV experiments; relatively minor asymmetries in one experiment were linked to slight asymmetries in the velocity profile at the inlet to the nozzle. CFD predictions of peak wall shear stress at the sudden contraction (normalized to that 0.015 m downstream) varied over two orders of magnitude, with variations of greater than 10 times even when the same software and turbulence model were used. This degree of shear stress variation will necessarily propagate through calculations of blood damage in medical devices. We conclude that CFD simulations used in qualifying medical devices for regulatory purposes need to be conducted following the best practices available, and that targeted experimental validation is essential. The results of this interlaboratory study are freely available in an internet repository (https://fdacfd.nci.nih.gov). We encourage the use of this model in further studies, and support the development of additional benchmarks, better modeling techniques, and consensus standards and guidelines for using CFD in the evaluation of medical devices.
Enterprisewide Information Management System for Transportation Right-of-Way Activities

Given the current state of technology—with service-oriented architecture, decentralized information, and desktop access to cloud computing and data management—enterprise systems for managing the information associated with business operations are necessary for improving efficiency and quality while optimizing resources. In transportation agencies, this situation is particularly true in the data-intense real estate offices that purchase and manage right-of-way property before construction. A structure is presented for a logical model of an enterprisewide information management system for transportation right-of-way activities. The business processes are based on the federal requirements as mandated by law and outlined in the Project Development Guide of FHWA's Office of Real Estate Services for appraisal, acquisition, relocation, and property management. The logical model is developed with the use of unified modeling language, which is considered to be a standard computer system modeling language rich in w...
Structure and function of the skeletal muscle extracellular matrix

The skeletal muscle extracellular matrix (ECM) plays an important role in muscle fiber force transmission, maintenance, and repair. In both injured and diseased states, ECM adapts dramatically, a property thathas clinical manifestations and alters muscle function. Here, we review the structure, composition, and mechanical properties of skeletal muscle ECM, describe the cells that contribute to the maintenance of the ECM and, finally, overview changes that occur with pathology. New scanning electron micrographs of ECM structure are also presented with hypotheses about ECM structure-function relationships. Detailed structure-function relationships of the ECM have yet to be defined and, as a result, we propose areas for future studies.
Surface Area Effects in Hydroxyapatite/Poly(ε‐caprolactone) Nanocomposites

In order to understand the contribution of nanoparticle surface area to the properties of nanocomposite materials, hydroxyapatite nanoparticles with different specific surface areas (60 m 2 ·g -1 and 111 m 2 ·g -1 ) were synthesized using reverse microemulsion and processed into nanocomposites. Experimental results indicated that the thermomechanical reinforcement did show a dependence on nanoparticle surface area, although the transition temperatures did not. The reinforcement trends were dependent on temperature, suggesting that the nanoparticles had a greater impact on the amorphous polymer chains. The reinforcement above T g may be plotted against nanoparticle surface area to obtain a single reinforcement trend, suggesting that surface area is a general parameter for nanocomposite property control.
Quantitative electron microscopy of microtubule assembly in vitro

The kinetics of microtubule assembly from purified porcine brain tubulin were examined by quantitative electron microscopy. Assembly at 37°C was initiated by the addition of GTP to 1 m m to the protein solution at ∼1 mg/ml in ammonium acetate buffer, pH 6·4. A solution of partially polymerized protein was mixed with a suspension of tomato bushy stunt virus at known particle concentration, and spray-deposited, in negative stain, upon specimen films. The resulting drop patterns were micrographed and the percent protein seen in distinguishable polymeric forms was calculated from the numbers, lengths, and known masses and mass/unit lengths of these entities. Clumping of protein by the uranyl acetate stain was avoided by use of a dual nebulizer which mixed protein and stain only upon spray droplet formation. The micrographs displayed ring-like forms, microtubules, and aggregates of parallel protofilaments—arrayed as flat, curved, and helical ribbons. Protein found as rings rapidly decreased from an initial 30% to a negligible amount at 2 minutes; the amount as microtubules increased asymptotically to an equilibrium value of 50% by 8 minutes; the quantity of ribbons was largest at 3 minutes (∼20%), but vanishingly small by 8 minutes. The results show that the fully formed microtubules consisted of protein which was initially both in the ring form and in the tubulin-dimer (6 S) form. They also quantitatively demonstrate that the twisted ribbons are assembly intermediates, those with a full protofilament complement presumably converting to microtubules by cylindrical folding.
An equilibrium model for predicting flue‐gas composition of an incinerator

The composition of an incinerator flue gas depends characteristically on the operating parameters such as combustion temperature, fractional excess air value, and moisture content of the waste material. An a priori knowledge of the influence of these parameters on the flue-gas composition helps to carry out the combustion process efficiently by appropriately selecting their values. A simple chemical equilibrium model is proposed to predict the flue-gas composition from an incinerator at different operating temperatures, excess air values, and moisture contents of the combusting material. The predicitions are supposed to establish the upper limit of the chemical species concentrations in the flue gas and hence the model is considered as an appropriate one for selecting the pollution control equipment and in estimating the upper limit of environmental contamination. The model-based computations predict that at a given temperature and moisture content, the increase in excess air decreases the concentrations of carbon monoxide, carbon dioxide, water, and hydrogen in the flue gas while it increases that of oxygen. Similarly, the proportion of nitrogen dioxide, nitrogen, sulfur dioxide and sulfur trioxide decreases while that of nitric oxide increases. At a given excess air and moisture content, the increase in temperature decreases the concentrations of carbon monoxide and hydrogen and increases of carbon dioxide and water due to better combustion. Similarly, the increase in temperature also augments the concentrations of nitric oxide, nitrogen dioxide and sulfur dioxide while it decreases that of nitrogen and sulfur trioxide. Similar trends are observed at different levels of moisture content.
Public relations in Taiwan: roles, professionalism, and relationship to marketing

Abstract This paper describes the practice of public relations in Taiwan. Specifically, this study discusses the major roles that Taiwanese practitioners perform in their organizations and the levels of professionalism. Through the use of qualitative questionnaire, this paper reports data collected from practitioners ( N =22) about roles, practices, the current status of the field, and the future aspirations of the practitioners. The results indicate: (1) most Taiwanese practitioners act as the “windows” (communication facilitators or boundary spanners) through which their organizations interact with their environments and (2) public relations is closely linked to marketing. The implications of these findings for the development of public relations in Taiwan are discussed.
Temocapril, an angiotensin converting enzyme inhibitor, protects against diabetes-induced endothelial dysfunction

The effect of chronic treatment with the angiotensin converting enzyme inhibitor, temocapril, on prevention of endothelial dysfunction was evaluated in an experimental model of diabetes mellitus. Endothelium-dependent relaxation to acetylcholine was impaired while endothelium-independent relaxation to nitroglycerin was unaltered in diabetic aortic ring segments. Treatment of diabetic animals with temocapril prevented the impaired endothelium-dependent relaxation without altering responses to nitroglycerin. Acetylcholine-induced relaxation was largely due to nitric oxide (NO)-mediated relaxation; however, a small but significant portion of relaxation in aortic rings from temocapril-treated diabetic rats was resistant to inhibition by the nitric oxide synthase (NOS) inhibitor, L-nitroarginine.