cssi/SciSciGPT-SciSciNet huggingface dataset:
Sensitivity of simulated CFC‐11 distributions in a global ocean model to the treatment of salt rejected during sea‐ice formation

We show that simulated oceanic absorption of an atmospheric gas is very sensitive to the representation of a process that occurs beneath sea ice. As sea ice forms, salt is rejected, locally increasing surface sea-water density. This dense water can sink to the pycnocline at the base of the mixed-layer. Previous studies have not considered the impact of this subgrid-scale process on transient tracers in the ocean. To assess the potential importance of this process to the oceanic absorption of atmospheric gases, we performed two idealized simulations: a Control simulation in which salt rejected during sea-ice formation is placed in the model's 25 m thick surface layer; and a Test simulation in which salt rejected during sea-ice formation is distributed uniformly through the upper 160 m beneath the forming sea ice. Our treatment of rejected salt is highly idealized, and is intended to demonstrate the need for a physically-based parameterization of subgrid-scale convection for use in ocean general circulation models that takes into account the subgrid-scale heterogeneity of surface buoyancy forcing. Distributing rejected salt more deeply during periods of ice formation helps to maintain vertical density gradients, inhibiting grid-scale convection, especially in the Southern Ocean. This greatly diminishes simulated ocean uptake of CFC-11, and generally improves simulated CFC-11 and salinity fields. The modeled global ocean inventory of CFC-11 for year 1990 is about 30% lower, and modeled column inventories in the Southern Ocean are up to 90% lower, in our Test simulation relative to our Control simulation. We infer that a more detailed treatment of subgrid-scale processes occurring beneath sea ice may diminish simulated oceanic absorption of anthropogenic CO2, especially in the Southern Ocean.
Binocular fusion inferences in a log-polar decision space

In the technical discipline of computer vision, the concept of using stereo cameras for depth perception has been motivated by the fact that, in human vision, one percept can arise from two retinal images as a result of the process of “fusion” in the visual cortex. If mankind wants to apply this concept to computer controlled machines it must be inferred that knowledge of the psychological process is sufficient to emulate, at least in a weak sense, the human sensory phenomena called vision. Typically, models for this emulation process have been computationally intensive. They contained or required massive amounts of data and thus resulted in very time consuming analytic solutions for depth or range information. The visual process, however complex, does not operate independently of other brain functions. For instance, the superior colliculus of the brain is used to generate information about visual field motion and many visual reflexes. The superior colliculus is also a multi-modal sensory area which includes auditory and somaethetic information [1]. This visual system-brain function connection must be kept in mind when one is attempting to utilize general visual system models to control manipulative processes in order to accomplish a task. In this paper we investigate the utilization of binocular fusion to determine range and heading angle for the specialized control task of guidance for an autonomous vehicle in a convoy following application. It is therefore necessary to develop the vision model, to define the decision space and to use multi-modal information when appropriate. Both parallel and convergent vision models have been utilized for this task. A comparison of calibration results, the mathematical advantages of a log-polar decision space and the resulting real-time structure for controlling a vehicle in a convoy mode are given from actual experimental evaluation.
Combination of Adhesive-tape-based Sampling and Fluorescence in situ Hybridization for Rapid Detection of Salmonella on Fresh Produce

This protocol describes a simple approach for adhesive-tape-based sampling of tomato and other fresh produce surfaces, followed by on-tape fluorescence in situ hybridization (FISH) for rapid culture-independent detection of Salmonella spp. Cell-charged tapes can also be placed face-down on selective agar for solid-phase enrichment prior to detection. Alternatively, low-volume liquid enrichments (liquid surface miniculture) can be performed on the surface of the tape in non-selective broth, followed by FISH and analysis via flow cytometry. To begin, sterile adhesive tape is brought into contact with fresh produce, gentle pressure is applied, and the tape is removed, physically extracting microbes present on these surfaces. Tapes are mounted sticky-side up onto glass microscope slides and the sampled cells are fixed with 10% formalin (30 min) and dehydrated using a graded ethanol series (50, 80, and 95%; 3 min each concentration). Next, cell-charged tapes are spotted with buffer containing a Salmonella-targeted DNA probe cocktail and hybridized for 15 - 30 min at 55°C, followed by a brief rinse in a washing buffer to remove unbound probe. Adherent, FISH-labeled cells are then counterstained with the DNA dye 4',6-diamidino-2-phenylindole (DAPI) and results are viewed using fluorescence microscopy. For solid-phase enrichment, cell-charged tapes are placed face-down on a suitable selective agar surface and incubated to allow in situ growth of Salmonella microcolonies, followed by FISH and microscopy as described above. For liquid surface miniculture, cell-charged tapes are placed sticky side up and a silicone perfusion chamber is applied so that the tape and microscope slide form the bottom of a water-tight chamber into which a small volume (≤ 500 μL) of Trypticase Soy Broth (TSB) is introduced. The inlet ports are sealed and the chambers are incubated at 35 - 37°C, allowing growth-based amplification of tape-extracted microbes. Following incubation, inlet ports are unsealed, cells are detached and mixed with vigorous back and forth pipetting, harvested via centrifugation and fixed in 10% neutral buffered formalin. Finally, samples are hybridized and examined via flow cytometry to reveal the presence of Salmonella spp. As described here, our "tape-FISH" approach can provide simple and rapid sampling and detection of Salmonella on tomato surfaces. We have also used this approach for sampling other types of fresh produce, including spinach and jalapeno peppers.
Single-walled carbon nanotube nanoring induces polymer crystallization at liquid/liquid interface

Abstract Polymer crystallization confined at liquid/liquid (L/L) interface has attracted increasing attention during the past decade. In this study, we show that single-walled carbon nanotubes (SWCNTs) can be bent into ring-shaped structure via a Pickering emulsion method. These SWCNT rings are pinned at L/L interface of nanosized oil droplets suspended in water. When dilute crystalline polymer solution was used as the oil phase, upon cooling, these polymers crystallize onto the SWCNT nanorings. This system thus provides a unique platform to investigate heterogeneous nucleation and crystal growth at L/L interface. Polyethylene, poly( l -lactic acid), and poly(3-hexylthiophene) are used as the crystalline homopolymers. Our results show that heterogeneous nucleation dominates the crystallization process, and nano hybrid shish kebab nanorings have been formed. Despite small diameters of the rings, the previously reported soft epitaxy mechanism still holds. Polyethylene-b-poly(ethylene oxide) has also been patterned onto the SWCNT nanorings, leading to hierarchically ordered nanostructures. The block copolymer-decorated SWCNTs have been used to direct nanoparticle assembly. Our work therefore shows a promising means to produce complex, hierarchical, and functional hybrid materials.
A 2D Bristle Friction Force Model for Contact Dynamics Simulation

This paper describes a 2D bristle contact friction model which is capable of modeling and simulating frictional behavior in both sliding and sticking regimes occurring in general 3D rigid-body contact. The model extends the 1D integrated bristle friction model to a 2D space by allowing the “bristle spring” to not only stretch along the direction of the relative velocity but also rotate due to the direction change of the velocity or motion trend in the common tangential plane of the contacting surfaces involved at the contact point of interest. With such an extension, the resulting friction model can be readily used to compute 3D contact friction forces in both sticking and sliding regimes for a general 3D contact dynamics model working with a multibody dynamics simulation application. Several simulation examples are provided to demonstrate the effectiveness of the model for predicting the experimentally seen frictional behavior such as sticking, stickslip, and sliding.Copyright © 2009 by ASME
Verification of a Byzantine-Fault-Tolerant Self-Stabilizing Protocol for Clock Synchronization

This paper presents the mechanical verification of a simplified model of a rapid byzantine-fault-tolerant self-stabilizing protocol for distributed clock synchronization systems. This protocol does not rely on any assumptions about the initial state of the system except for the presence of sufficient good nodes, thus making the weakest possible assumptions and producing the strongest results. This protocol tolerates bursts of transient failures, and deterministically converges within a time bound that is a linear function of the self-stabilization period. A simplified model of the protocol is verified using the symbolic model verifier (SMV). The system under study consists of 4 nodes, where at most one of the nodes is assumed to be Byzantine faulty. The model checking effort is focused on verifying correctness of the simplified model of the protocol in the presence of a permanent byzantine fault as well as confirmation of claims of determinism and linear convergence with respect to the self-stabilization period. Although model checking results of the simplified model of the protocol confirm the theoretical predictions, these results do not necessarily confirm that the protocol solves the general case of this problem. Modeling challenges of the protocol and the system are addressed. A number of abstractions are utilized in order to reduce the state space.
Inhibition of Inflammatory Mediators Role of Statins in Airway Inflammation

Objective. To determine if statins induce anti-inflammatory effects in upper airway inflammation. Mediators of innate and adaptive immunity regulate airway inflammation. Release of these mediators involves enzymatic conversion of polyunsaturated fatty acids into biologically active mediators, which can be blocked by statins. Although upper airway inflammation and chronic sinusitis occur in millions of patients with asthma worldwide, the anti-inflammatory effects of statins in upper airway inflammation have not been previously studied.Study Design. Laboratory research.Setting. Tertiary referral center.Subjects and Methods. Analysis of sinus tissues collected from patients with chronic rhinosinusitis revealed suppression of highly expressed inflammatory mediators in patients who were found to be on statins, suggesting that statins may induce anti-inflammatory effects. Therefore, the authors performed an in vitro study to determine if these anti-inflammatory effects were induced by statins. Cultured primary ...
Tiers of Intervention in Responsiveness to Intervention Prevention Outcomes and Learning Disabilities Identification Patterns

Response to Intervention (RTI) models have attracted great attention as an alternative to traditional methods used for identifying students with learning disabilities. A major feature of this approach is the implementation of academic interventions in general education and measuring the student's response to those interventions. A common question that needs to be addressed is the number of stages or tiers of intervention necessary in the Response to Intervention model. This article reviews three studies of RTI that investigate the RTI tiers. Sharon Vaughn and Rollanda O'Connor report on studies using the Standard Protocol approach to RTI. David Tilly reports on using the Problem Solving Model as an RTI model. This article summarizes the results of these three investigations.
Structurally characterized luminescent lanthanide zinc carboxylate precursors for Ln-Zn-O nanomaterials.

A novel family of lanthanide zinc carboxylate compounds was synthesized, characterized (structural determination and luminescent behavior), and investigated for utility as single-source precursors to Ln–Zn–O nanoparticles. Carboxylic acids [H–ORc = H–OPc (H–O2CCH(CH3)2, H–OBc (H–O2CC(CH3)3, H–ONc (H–O2CCH2C(CH3)3)] were individually reacted with diethyl zinc (ZnEt2) to yield a set of previously unidentified zinc carboxylates: (i) [Zn(μ-ORc)3Zn(μ-ORc)]n [ORc = OPc (1), ONc (2)], (ii) [(py)Zn]2(μ-ORc)4 [ORc = OBc (3), ONc (4), and py = pyridine], or (iii) Zn(ORc)2(solv)2 [ORc/solv = OPc/py (5), OcNc/H2O (6) (OcRc = chelating)]. Introduction of lanthanide cation [Ln[N(SiMe3)2]3, ZnEt2, and HOBc in py] yielded the mixed cationic species structurally characterized as: (i) (OcBc)Ln[(μ-OBc)3Zn(py)]2 [Ln = Pr (7), Nd (8), Sm (9)] or (ii) (py)2Zn(μ-OBc)3Ln(OcBc)2(py) [Ln = Tb (10), Dy (11), Er (12), Y (13), Yb (14)]. Exploration of alternative starting materials [Ln(NO3)3·nH2O, Zn(O2CCH3)2, HOBc in py] led to the isolation of (NO3c)Ln[(μ-OBc)3Zn(py)]2 [Ln = La (15), Ce (16), Pr (17), Nd (18), Sm (19), Eu (20), Gd (21), Tb (22) Dy (23), and Er (24); NO3c = chelating]. The UV-vis spectra of 7–24 revealed standard absorption spectra for the Ln cations. Representative compounds were used to generate nanoparticles from an established 1,4-butanediol-based solution precipitation route. The nanoproducts isolated adopted either a mixed zincite/lanthanum oxide (18n or 22n) or pure zincite (8n or 10n) phase dependent on NO3 or OBc moiety. Fluorescence was not observed for any of these nanomaterials possibly due to phase separation, low crystallinity, surface traps, and/or quenching based on elevated Ln cation content.
An Alternative Method for Determining the Neutral Zone of Spinal Motion Segment Units

In-vitro mechanical testing of spinal motion segments has the potential to provide insight into mechanisms of intervertebral disc degeneration as well as a means for evaluating treatments. We describe a novel tri-linear method for quantifying the non-linear load-displacement behavior which is robust across different spinal levels, and quantifies stiffness at low-loads, which has not been included by previous threshold based methods. Mechanical data from in-vitro compression/tension testing of rodent motion segments is used to compare our tri-linear method with a threshold based method, and demonstrates that our method is insensitive to spinal level as well as provides constitutive information for low-load behavior.Copyright © 2003 by ASME
The Rationality Crisis in US Higher Education

Over the course of the last century, many of the stresses and contradictions of advanced capitalism have been displaced onto colleges and universities, which are now directly attached to the state—whether legally, politically, or financially—as an important component of the ideological and economic state apparatuses. As a component of the ideological and economic state apparatuses, the university is implicated in the state's ongoing fiscal crisis as both a cause of the crisis and a solution to the crisis. The author argues that the possibilities for crisis management within the existing corporate model of higher education have been exhausted in a rationality crisis that threatens to implode the administrative apparatus in higher education. The author calls for a radical reconstruction of power relationships within the university and in its relationships to capital and the state.
Mycobactin-mediated iron acquisition within macrophages

Restricting the availability of iron is an important strategy for defense against bacterial infection1,2,3. Mycobacterium tuberculosis survives within the phagosomes of macrophages; consequently, iron acquisition is particularly difficult for M. tuberculosis, because the phagosomal membrane is an additional barrier for its iron access4,5. However, little is known about the iron transport and acquisition pathways adapted by this microbe in vivo6. Extracellular iron sources are usually mobilized by hydrophilic siderophores7,8. Here, we describe direct evidence that mycobactins, the lipophilic siderophores of mycobacteria, efficiently extract intracellular macrophage iron. The metal-free siderophore is diffusely associated with the macrophage membrane, ready for iron chelation. Notably, the mycobactin-metal complex accumulates with high selectivity in macrophage lipid droplets, intracellular domains for lipid storage and sorting9,10. In our experiments, these mycobactin-targeted lipid droplets were found in direct contact with phagosomes, poised for iron delivery. The existence of this previously undescribed iron acquisition pathway indicates that mycobacteria have taken advantage of endogenous macrophage mechanisms for iron mobilization and lipid sorting for iron acquisition during infection. The pathway could represent a new target for the control of mycobacterial infection.
Taylor series direct method for variational problems

Abstract A direct method for solving variational problems using Taylor series is discussed. Properties of Taylor series are briefly presented and an operational matrix is utilized to solve the variational problems by means of a direct method. An illustrative example is given.
Shared Leadership in Teams: An Investigation of Conflict and Task Performance

Shared leadership posits that multiple leaders within a team can exist simultaneously, and that each member can assume a complimentary leadership role. This study examines the relationship between ...
Consumer Welfare Implications of Changes in Interstate Telephone Pricing

Past practice in regulating telephone prices has encouraged telephone companies to incur excessive costs. The Federal Communications Commission has recently changed some of these practices. In this paper the consumer welfare implications of some of these changes are examined, primarily the institution of interstate subscriber line charges and changes in the procedures for allocating costs among jurisdictions. The conclusion is that these changes serve consumer interests.
Absorption coefficients for the infrared vibration-rotation spectrum of FeO

Abstract Relative absorption coefficients have been calculated for the infrared vibration-rotation spectrum of FeO using the smeared-line model. Band-heads occur in the R -branch. Line-by-line calculations show that errors incurred through the use of the just-overlapping-line model are small at least up to temperatures of 3500°K. Numerical calculations reveal the expected spectral structure. Measurements of emission just beyond the head of the band corresponding to the → 1 transition should allow determination of an average line-broadening parameter.
Effect of nitrate infusions on the systemic and coronary circulations following acute experimental myocardial infarction in the intact dog.

Abstract To determine the systemic and the coronary effects of nitrates in acute myocardial infarction, 3 groups of anesthetized closed chest dogs were studied. In a group of normal dogs an hour-long intravenous infusion of isosorbide dinitrate was administered. In a second group a small infarct of the myocardium was produced by catheter wedging in a small coronary side branch. In the third group occlusion of a branch of the main left coronary artery was produced by a thrombus-forming catheter electrode. Isosorbide dinitrate infusion in normal dogs caused reductions in aortic pressure, left ventricular end-diastolic pressure and cardiac output and work. Coronary resistance was reduced only at 5 minutes of infusion. Systemic effects of isosorbide dinitrate were similar in the 2 groups with infarction. Mild hypotension (average 10 mm Hg) did not provoke ventricular arrhythmias. Unlike the cardiac output in normal dogs, this value tended to rise rather than fall and left ventricular work was unchanged. The dogs with catheter wedging showed a significant increase in coronary collateral flow and a decrease in resistance. Narrowing of the coronary arteriovenous oxygen difference occurred in the dogs with wedging and thrombus formation. In the absence of cardiogenic shock nitrates may be safely administered to dogs with acute experimental myocardial infarction and may result in enhanced collateral coronary flow and reduction in oxygen requirements of the heart.
XPS studies of the valence electron levels of metalloporphyrins

Abstract We have studied the valence electron spectra of several tetraphenylmetalloporphyrins by XPS. The most striking features of the spectra are those derived from the metal d levels. These reveal that the metal and porphine levels are nearly uncoupled in the copper and zinc porphyrins but that the two kinds of levels interact more extensively in the cobalt compound.
The cyclical sensitivity of white-collar skill margins

In this paper the authors assess the extent to which white-collar skill margins (SMs) fluctuate over the business cycle. Whether the SM increases (decreases) during economic expansion (recession) or moves in an opposite direction depends on the elasticity of supply of highly skilled and entry level workers and, according to Oi's model of labor as a quasi-fixed factor, the fixed employment costs incurred by firms in hiring each of these categories of labor. Since the effects of supply elasticity and fixed employment costs tend to offset each other, the cyclical sensitivity of the white-collar SM can only be ascertained by recourse to empirical data. Bureau of Labor Statistics data from the Professional, Administrative, Technical, and Clerical Survey covering the period 1962–85 are used for this purpose.
Negative appendectomy in pregnant women is associated with a substantial risk of fetal loss.

Background The preoperative diagnosis of acute appendicitis is often inaccurate in pregnant women, and complicated appendicitis is associated with a high rate of fetal loss. The study objective was to evaluate rates of fetal loss and early delivery in pregnant patients undergoing appendectomy, using a large population-based database. Study Design Using the California Inpatient File, we retrospectively analyzed all women undergoing appendectomy between 1995 and 2002 for pregnancy, diagnosis, operative technique, fetal loss, and early delivery during the same hospitalization as appendectomy. Results Of 94,789 women who underwent appendectomy, 3,133 were pregnant. Complicated appendicitis was found in 30% of pregnant women and 29% of nonpregnant women (p=NS). The rate of negative appendectomy was considerably higher in pregnant compared with nonpregnant women (23% versus 18%, p Conclusions The current approach to possible acute appendicitis in pregnant women puts 23% at risk for fetal loss, even though they have a normal appendix. These data indicate that reducing fetal loss in pregnant women suspected of having acute appendicitis will require more accurate diagnosis to avoid unnecessary operation.
Testing candidate genes for non-syndromic oral clefts using a case-parent trio design.

Markers in five candidate genes were examined on 269 case-parent trios ascertained through a child with an isolated, non-syndromic oral cleft (cleft lip, CL; cleft palate, CP; or cleft lip and palate, CLP). Cases and their parents were ascertained through treatment centers in Maryland. Markers at two of the five candidate genes, transforming growth factor beta3 (TGFbeta3) and MSX1, showed consistent evidence of linkage and disequilibrium due to linkage using several statistical tests (e.g., the global chi-square for TGFbeta3 was 21.1 with 12 df, P = 0.03; that for MSX1 was 8.7 with 3 df, P = 0.03). There was little evidence of heterogeneity in the role of TGFbeta3 between different types of oral clefts, but MSX1 did yield marginal evidence for such heterogeneity. MSX1 also showed evidence for interaction between infant's genotype and maternal smoking, giving a likelihood ratio test for heterogeneity between smoker and non-smoker mothers of 7.16 (2 df, P = 0.03). Using a conditional logistic model to test for gene-gene interaction showed no evidence of interaction between TGFbeta3 and MSX1, with both seeming to contribute independently to risk of isolated, non-syndromic oral clefts.
Management and treatment outcomes of marginal ulcers after Roux-en-Y gastric bypass at a single high volume bariatric center

Abstract Background Marginal ulceration (MU) is one of the most common complications after Roux-en-Y gastric bypass (RYGB). However, the rate of MU varies from 1% to 16% of RYGB patients and predisposing factors remain unclear. The aim of this study is to describe frequency, management, and outcomes of treatment in patients with MU after laparoscopic RYGB. Methods Between January 2004 and December 2012, a total of 2,535 patients underwent laparoscopic RYGB at our institution. Patients were routinely placed on proton pump inhibitors (PPI) for 90 days after the procedure. A total of 59 (2.3%) patients presented with MU. A retrospective review of a prospectively collected database was performed for all patients. Results Patients with MU presented with abdominal pain (n = 35), nausea/vomiting (n = 9), anemia (n = 5), hematemesis (n = 5), and dysphagia (n = 5) as chief complaints. Diagnosis was made at a mean period of 15.2±17.4 months (range, 1–64) after the laparoscopic RYGB. Of these patients, 26 (44.1%) required reoperations including 12 (20.3%) with perforated ulcers. Urgent operation was required in 14 (23.7%) patients due to perforation or active bleeding, and elective operation was performed in 10 (16.9%) patients for chronic and refractory MU or gastrogastric fistula. One (1.7%) patient developed recurrent MU after the revision and had another revision of the anastomosis. One (1.7%) patient underwent reversal of gastric bypass after the revision due to malnutrition and recurrent ulcers. All patients did well at a mean follow up of 28.9±21.7 months (range, 1–78 mo). Conclusion Despite the use of routine PPI, the incidence of MU was not insignificant. A significant portion of patients required surgical treatment. Perforations can be effectively managed by oversewing of the ulcer.
Precision extruding deposition and characterization of cellular poly‐ε‐caprolactone tissue scaffolds

Successes in scaffold guided tissue engineering require scaffolds to have specific macroscopic geometries and internal architectures to provide the needed biological and biophysical functions. Freeform fabrication provides an effective process tool to manufacture many advanced scaffolds with designed properties. This paper reports our recent study on using a novel precision extruding deposition (PED) process technique to directly fabricate cellular poly‐e_rm;‐caprolactone (PCL) scaffolds. Scaffolds with a controlled pore size of 250 μm and designed structural orientations were fabricated.
Where was the wall then? Where is it now?

This article investigates the power of ‘walls’ to constrain thought and silence diverse voices of reason within planning. Using die Mauer (The Berlin Wall) as a linking metaphor, this article juxtaposes mid‐1950s planning in a spatially‐ and ideologically‐divided Berlin (Germany) against Harland Bartholomew's mid‐1950s planning in a racially‐divided Louisville, Kentucky (USA). It then juxtaposes the latter against a mid‐1950s narrative about efforts to desegregate housing in Louisville. This juxtaposition reveals that some people in Louisville used the Cold War divide between East and West to reinforce the long‐standing racial divide between blacks and whites. Moreover, it reveals that, by deferring to Cold War‐related racial politics that could not be questioned, Bartholomew's technical approach to planning silenced other voices of reason and thereby reflected and reproduced the race‐inflected politics of the Cold War divide. The article concludes by briefly considering what Bartholomew might have done d...
Role of multiple ArcA recognition sites in anaerobic regulation of succinate dehydrogenase (sdhCDAB ) gene expression in Escherichia coli

Succinate dehydrogenase (sdhCDAB) gene expression in Escherichia coli is negatively regulated by the arcA and fnr gene products during anaerobic cell growth conditions. The controlled synthesis of this sole membrane-bound enzyme of the tricarboxylic acid cycle allows optimal participation in the aerobic electron transport pathway for the generation of energy via oxidative phosphorylation reactions. To understand how ArcA participates in the anaerobic repression of sdhCDAB expression, a family of sdhC-lacZ fusions was constructed and analysed in vivo. DNase I footprint and gel shift assays using purified ArcA protein revealed the location of four distinct and independent ArcA binding sites in the sdhC promoter region. ArcA sites, designated sites 1 and 2, are centred at -205 bp and -119 bp upstream of the sdhC promoter, respectively, whereas ArcA site 3 overlaps the -35 and -10 regions of the sdhC promoter. A fourth ArcA site is centred at +257 bp downstream of the sdhC promoter. They are bound with differing affinity by ArcA and ArcA phosphate. The in vivo studies, in combination with the in vitro studies, indicate that ArcA site 3 is necessary and sufficient for the ArcA-dependent repression of sdhC gene expression, while the DNA region containing ArcA site 2 contributes to maximal gene expression. The DNA-containing ArcA sites 1 and 4 provide minor roles in the ArcA regulation of sdhC expression. Lastly, the Fnr-dependent control of sdhCDAB gene expression was shown to occur independently of the ArcA and to require DNA sequences near the start of sdhC transcription.
Serial measurement of nonspecific immune parameters in chronically hemodialyzed renal failure patients

Nonspecific immune monitoring of the percentage active T (A-T) rosette-forming cells (RFC) and spontaneous blastogenesis (SB) appear to be useful indexes of host reaction toward allografts. In order to assess the significance of the observed changes, renal failure patients were serially evaluated before and after hemodialysis for the percentage of total T (T-T) and A-T RFC and for peripheral blood leukocyte metabolic activity measured by a whole blood spontaneous blastogenesis (SB) assay. Renal failure patients had a significantly lower (P<0.05) percentage of T-T RFC than normal persons, while the percentage A-T RFC and SB remained stable. A hemodialysis treatment did not change the mean values of any of the three parameters. On the other hand, serial patient evaluation over 3 months revealed significant fluctuations in the percentage T-T RFC, but not the percentage A-T RFC and SB. Since the percentage A-T RFC and SB are relatively constant measures of immune status in ungrafted patients, significant changes in these nonspecific immune probes may reflect allograft rejection.
Three hundred years of forest and land‐use change in Massachusetts, USA

Aim The aim of this study was to document changes in forest composition, structure and distribution across Massachusetts, USA, from the time of European settlement (seventeenth century) to the present, and to investigate environmental and historical influences on regional patterns of variation. Location The study area encompasses the State of Massachusetts (69.9–73.5°E, 41.3–42.9°N), a 21,000-km2 area in the north-eastern United States. Methods A wide range of historical sources was used to document changes in land use and land cover for the historical period. Witness trees from early land surveys enabled us to evaluate vegetation patterns prior to widespread European settlement, and to compare historical and modern species composition. Nineteenth century maps of forest cover and contemporary agricultural censuses documented forest patterns during the peak agricultural period. Geographic Information System analyses were used to relate variation in climate, geology and land-use history to historical and modern forest composition. Results Massachusetts has a complex east-to-west environmental gradient involving changes in physiography, climate, geology and natural disturbance. Until the middle of the twentieth century, agriculture was the most important land-use across the region; although the percentage of land in agriculture and the timing of major land-use changes were remarkably consistent across the state, historical forest patch sizes varied locally and regionally in relation to physiography. Forest composition of both early historical and modern forests is most strongly related to environmental conditions, especially variation in climate. Historical land-use resulted in a state-wide increase in early successional tree species and a dramatic, although recovering, change in forest structure. Main conclusions At a regional scale, environmental conditions apparently control broad patterns of variation in vegetation composition. Historical land-use practices were relatively homogenous across Massachusetts and local variation was reduced through data averaging at broad spatial scales. At finer spatial scales, historical land-use has strong and persistent impacts on vegetation composition and structure.
Effects of diuretics and papaverine during hand-assisted, laparoscopic, donor nephrectomy

Abstract Introduction: Our study purpose was to quantify the effects of diuretics and vasodilators on renal function during hand-assisted laparoscopic donor nephrectomy (HALDN) in a porcine model. Methods: Animals undergoing left HALDN had urine output (UO,mL/Kg/min) and creatinine clearance (CrCl,mL/min) values of each kidney serially measured, independently. Measurements were obtained after 30 minutes of baseline pneumoperitoneum, after renal vessel isolation, after 15 minutes of desufflation, and after 30 minutes of desufflation, following left nephrectomy. Swine (n = 28) were divided into: Group I:no medications. Group II:intravenous mannitol prior to, and furosemide after vessel isolation. Group III:perihilar papaverine-soaked gauze placed for 15 minutes prior to vascular dissection/isolation. Group IV:mannitol, furosemide, and papaverine gauze. Standard statistical methods determined intragroup differences (p Results: Bilateral CrCl decreased during surgery, with no differences between the groups. Only the right kidneys recovered to baseline CrCl after release of pneumoperitoneum. Total UO was lower in the left compared to the right, non-operated kidney in Groups I (0.20 vs 0.31, p=0.003), II (0.65 vs 1.26, p=0.007), III (0.45 vs 0.82, p=0.01), and IV (0.87 vs 1.38, p=0.01). Total UO from the left kidney was greater in the diuretics plus papaverine (0.87) and diuretics alone groups (0.65) compared to papaverine alone (0.45) or control (0.20) (p = 0.0001). A similar observation occurred in the right kidney. Conclusions: Pneumoperitoneum with renal and vascular manipulation impacts renal function of both kidneys during HALDN. Mannitol and furosemide alone, or in combination with papaverine, attenuates these adverse effects, possibly preserving the renal function of both the allograft and contralateral kidney during HALDN.
Economic rationality and social development: An iranian case study

T. B. BOTTOMORE 1 AND REINHARD BENDIX 2 have recently appealed for the use of the comparative sociological method in order to better understand the social processes of our time. In using this method, Bendix in particular has stated that, first, the formulation of abstract, ideal-types (and I would here add, abstract, symbolic, or cultural systems) should be supplemented by concrete cases specifically describing how such ideal constructs work empirically; second, that limited generalizations (typologies) may be more fruitful than universals in formulating comparative constructs; and third, that variations in time in the constructs are significant. I should like to take advantage of all three observations in presenting a case history of the trials and tribulations of an Iranian textile plant, and in interpreting the significance of this case history in the light of the comparative sociological method. Because the existing Iranian political situation demands that I protect my sources, the case study has had to be a composite of three specific cases in two Iranian urban centers. However, even though I have had to use the composite technique in this presentation, that composite is not an abstract ideal-type, and so does not violate Bendix's first requisite. At the same time, however, I must admit that I selected this case study because I am convinced that the study is not an isolated instance of Iranian economic behavior, but is common enough to impair-more than that, to block--economic development in Iranian society.
Informal learning: Student achievement and motivation in science through museum-based learning

This study examined changes in student motivation and achievement in science during a visit to a university children’s science museum. The study was based on the pretest–posttest control comparison group design with four treatment groups: control, exhibit, lesson and exhibit/lesson. The sample consisted of 228 sixth-grade students from a Louisiana public school who were randomly assigned to one of the four experimental groups. Pretest, posttest and delayed posttest measures of intrinsic motivation and achievement in science were obtained using the Children’s Academic Intrinsic Motivation Inventory and an achievement test written to measure areas of science incorporated in the museum exhibits. The data were analysed using a one-way ANOVA, dependent t tests and Pearson r. Significant differences were found within groups for (1) the lesson group in motivation and (2) the exhibit group in achievement from pretest to posttest and from posttest to delayed posttest. A significant relationship between level of motivation and science achievement was revealed for the exhibit group on the delayed posttest. There were no other significant findings to support that the treatment led to any long-term effects on motivation or achievement within any of the four experimental groups.
Assembly of Ligand-Stripped Nanocrystals into Precisely Controlled Mesoporous Architectures

The properties of mesoporous materials hinge on control of their composition, pore dimensions, wall thickness, and the size and shape of the crystallite building units. We create ordered mesoporous materials in which all of these parameters are independently controlled. Different sizes (from 4.5 to 8 nm) and shapes (spheres and rods) of ligand-stripped nanocrystals are assembled using the same structure-directing block copolymers, which contain a tethering domain designed to adsorb to their naked surfaces. Material compositions range from metal oxides (Sn-doped In2O3 or ITO, CeO2, TiO2) to metal fluorides (Yb,Er-doped NaYF4) and metals (FePt). The incorporation of new types of nanocrystals into mesoporous architectures can lead to enhanced performance. For example, TiO2 nanorod-based materials withstand >1000 electrochemical cycles without significant degradation.
Solid-State Nanopore Detection of Epigenetic DNA Modifications

We describe protein-facilitated solid-state nanopore detection of dsDNA containing single modified nucleotides. We first use model mono-biotinylated oligonucleotides to determine the detection limits of the assay by systematically studying the effect of DNA length and biotin position to better understand the detection process. We then investigate epigenetic modifications by combining selective biotinylation of target modified bases and a charged, high-affinity protein tag to induce translocation events. We use this approach to resolve two major epigenetic modifications: methylcytosine (5mC) and hydroxymethylcytosine (5hmC).
Characterization of hydrophobicity gradients prepared by means of radio frequency plasma discharge

Abstract A hydrophobicity gradient was created by gradually exposing a polydimethylsiloxane film to a radio frequency glow discharge in an oxygen atmosphere. A change in contact angle from 100 to 0° was measured along the gradient surface by means of the Wilhelmy balance technique. The gradient surface was characterized by studying the adsorption from single protein solutions of human albumin, IgG and fibrinogen using total internal reflectance fluorescence (TIRF). Generally, adsorption values similar to monolayer capacities were measured on the hydrophobic side. The adsorption decreased towards the hydrophilic end in correspondence with the change in contact angle. The displacement of proteins with a ethylene oxide-propylene oxide copolymer (EO70PO100EO70) was higher on the hydrophobic side than on the hydrophilic side. Albumin showed an adsorption peak in the wetting transition region, indicating a very strong affinity.
Simulated diffusion dynamics in river networks

Abstract River networks and the associated riparian zones are important landscape elements. The movement of organisms within river or riparian networks can be regarded as a diffusion process. The dynamics of diffusion in such networks will depend upon an interplay of (1) the geometry of the network, (2) the movement behavior of individual organisms, and (3) the spatiotemporal scale of observation. We examine the interplay of these factors by simulating unbiased and biased random walks on two types of artificial river networks. The resulting diffusion dynamics often depart strongly, both quantitatively and qualitatively, from classical (Fickian) dynamics. Measures of diffusive behavior, such as mean squared displacement and mean number of sites visited, can typically be described as power-law functions of time. However, the exponents of power laws often have non-classical values, and crossovers between different power-law behaviors at different temporal scales are common. Many qualitative features of the simulated diffusion dynamics are explicable in terms of network geometry; the potential role of tributaries in impeding diffusion is particularly apparent. An understanding of diffusion dynamics is likely to be a key factor in predicting rates of gene flow, spread of diseases or invading species, predator-prey interactions, and other ecological processes in river networks.
Evaluation of the MagNA Pure LC used with the TRUGENE™ HBV Genotyping Kit

Abstract Background: The current manual sample processing method recommended for use with the TRUGENE™ HBV Genotyping Kit (TRUGENE HBV; Bayer HealthCare LLC, Tarrytown, NY) is labor-intensive and may be prone to specimen cross-contamination. Recent evaluations of the MagNA Pure LC (MP; Roche Applied Science, Indianapolis, IN) suggest that it is suitable for automated, contamination-free extraction and purification of viral nucleic acids from large-volume (1.0 mL) serum or plasma specimens. Objectives: We evaluated the MP Total Nucleic Acid Isolation Kit—Large Volume (Roche Applied Science) in conjunction with TRUGENE HBV to establish the analytical sensitivity (threshold titer) of the assay, in HBV DNA International Units (IU)/mL, for obtaining consistent, interpretable sequence data from TRUGENE HBV. Study design: HBV analytical standards, prepared as 10 replicates (1.0 mL each) at each of the following concentrations: 200, 1000, 5000, and 10,000 IU/mL, were processed by MP and analyzed by TRUGENE HBV according to manufacturer's instructions. Performance of TRUGENE HBV used in conjunction with MP sample processing was evaluated further using 22 clinical serum specimens containing low titers of HBV DNA. Results: All replicates of HBV analytical standards at 1000, 5000, and 10,000 IU/mL yielded interpretable TRUGENE HBV sequences, whereas interpretable sequences were obtained in 90% (9 of 10) of the replicates at 200 IU/mL. TRUGENE HBV sequences were interpretable in 86% (19 of 22) of the clinical specimens studied. Conclusions: MP sample processing is efficient and suitable for use with TRUGENE HBV. When combined with MP sample processing, TRUGENE HBV yielded interpretable sequences from HBV analytical standards and clinical serum specimens with HBV DNA titers of ≥200 IU/mL.
Stochastic modeling of autoignition in turbulent non-homogeneous hydrogen–air mixtures

The autoignition of turbulent non-homogeneous hydrogen–air mixtures is studied using the linear-eddy model (LEM). The initial solution consists of fully segregated regions of fuel and oxidizer mixtures. The relative size of these regions represents a measure of mixture heterogeneity, while the specified turbulence conditions determine the subsequent evolution of the dissipation rate field. Chemistry and transport are described accurately using a detailed mechanism for hydrogen–air chemistry and the CHEMKIN libraries. The simulations are implemented for a range of pressures and initial mixing conditions to identify the effects of mixing on the dominant autoignition chemistry. The simulations show that some of the salient features of the coupling between autoignition chemistry and mixing may adequately be captured by the LEM. This coupling includes the competing roles of mixing on this chemistry. Mixing can increase the volumetric rate of reaction and heat release by increasing the interface between ignition fronts and unburnt gases; it also contributes to homogenizing the mixture. & 2008 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.
Trends in Tariff Reforms and in the Structure of Wages

Abstract This paper provides new evidence on the impacts of trade reforms on wages. We first introduce a model of trade that combines a noncompetitive wage-setting mechanism due to unions with a factor abundance hypothesis. The predictions of the model are then econometrically investigated using Argentine data. Instead of achieving identification by comparing industrial wages before and after one episode of trade liberalization, our strategy exploits the recent historical record of policy changes adopted by Argentina: from significant protection in the early 1970s, to the first episode of liberalization during the late 1970s, then back to a slowdown of reforms during the 1980s, and finally to the second episode of liberalization in the 1990s. These swings in trade policy represent broken trends in trade reforms that we can compare with observed trends in wages and wage inequality. We use unusual historical data sets of trends in tariffs, wages, and wage inequality to examine the structure of wages in Arge...