cssi/SciSciGPT-SciSciNet huggingface dataset:
Single-stranded RNA Recognition by the Bacteriophage T4 Translational Repressor, RegA

The T4 protein, RegA, is a translational repressor that blocks ribosome binding to multiple T4 messages by interacting with the mRNAs near their respective AUG start codons. Other than the AUG, there are no obvious similarities between the affected mRNAs. High affinity RNA ligands to RegA were isolated using SELEX (systematic evolution of ligands by exponential enrichment). The selected RNAs exhibited the consensus sequence 5'-AAAAUUGUUAUGUAA-3'. The AUG was invariant, suggesting that it is the primary effector of binding specificity. The UU immediately 5' to the AUG and the upstream poly(A) tract were highly conserved among the selected RNAs. Boundary and footprinting experiments are consistent with the consensus sequence defining the RegA-binding site. Interestingly, chemical modification and nuclease digestion data indicate that the RNA-binding site is single-stranded, as if RegA discriminates between targets based on their primary sequence, not their secondary structure. Minor variations from the consensus at positions other than the universally conserved AUG have little effect on RegA binding, but accumulation of mutations has a profound effect on the interaction. Comparison of the in vivo targets for RegA to the SELEX-generated consensus suggests a repression pattern whereby the translation of individual messages is sequentially halted until the least similarly affected message, the regA gene itself, is repressed.
River runoff effect on the suspended sediment property in the upper Chesapeake Bay using MODIS observations and ROMS simulations

Ocean color data derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) on the satellite Aqua from 2002 to 2012 and simulations from the Regional Ocean Modeling System (ROMS) are used to study the impact of the Susquehanna River discharge on the total suspended sediment (TSS) concentration in the upper Chesapeake Bay. Since the water in the upper Chesapeake Bay is highly turbid, the shortwave infrared (SWIR)-based atmospheric correction algorithm is used for deriving the normalized water-leaving radiance nLw(λ) spectra from MODIS-Aqua measurements. nLw(λ) spectra are further processed into the diffuse attenuation coefficient at the wavelength of 490 nm Kd(490) and TSS. MODIS-Aqua-derived monthly TSS concentration in the upper Chesapeake Bay and in situ Susquehanna River discharge data show similar patterns in seasonal variations. The TSS monthly temporal variation in the upper Chesapeake Bay is also found in phase with the monthly averaged river discharge data. Since the Susquehanna River discharge is mainly dominated by a few high discharge events due to winter-spring freshets or tropical storms in each year, the impact of these high discharge events on the upper Chesapeake Bay TSS is investigated. Both MODIS-measured daily TSS images and sediment data derived from ROMS simulations show that the Susquehanna River discharge is the dominant factor for the variations of TSS concentration in the upper Chesapeake Bay. Although the high river discharge event usually lasts for only a few days, its induced high TSS concentration in the upper Chesapeake Bay can sustain for ∼10–20 days. The elongated TSS rebounding stage is attributed to horizontal advection of slowly settling fine sediment from the Susquehanna River.
A biomechanical study of the static stabilizing effect of knee braces on medial stability

The purpose of this project was to determine if com mercially available braces could be shown to produce objective evidence of medial stabilization of the knee. Commercially available athletic braces were evaluated for their effect on abduction forces applied to a cadaver knee with no instability and with experimentally created medial instability. Under computer control, abduction forces were applied while simultaneous data were ob tained from an electrogoniometer and transducers ap plied to the anterior cruciate ligament and the superficial medial collateral ligament at 0°, 15°, and 30° of flexion. Our results showed a reduction in abduction angle using functional braces, whereas prophylactic braces demonstrated little or no protective effect.
Laser workshops in neurological surgery.

With the recent increased popularity of laser use in neurosurgery, there arises the question of the value and necessity of a “hands-on” laser workshop in preparing the surgeon for clinical use of the instrument. To find an answer, a questionnaire was recently circulated to those who had participated in such a workshop. Participants were asked whether they were actually using the laser clinically since attending the workshop and, if so, the type of laser they were using. Whether the course was influential in their decision to use a laser and whether they felt they could have used the instrument without such a course was also asked. In addition, the surgeons were asked how long it took them to become comfortable using the laser. The types of procedures, the percentage of operative cases and the mode (freehand or microlinked) in which the laser was used was also investigated. Finally, absolute indications for laser use in neurosurgery and methods to improve laser education were sought. The answers were varied and interesting, but it is our conclusion that a “hands-on” workshop is both a valuable and necessary means of preparing a neurosurgeon for clinical use of a laser, and participation in such a course should be encouraged.
Treatment with the Non-ionic Surfactant Poloxamer P188 Reduces DNA Fragmentation in Cells from Bovine Chondral Explants Exposed to Injurious Unconfined Compression

Excessive mechanical loading to a joint has been linked with the development of post-traumatic osteoarthritis (OA). Among the suspected links between impact trauma to a joint and associated degeneration of articular cartilage is an acute reduction in chondrocyte viability. Recently, the non-ionic surfactant poloxamer 188 (P188) has been shown to reduce by approximately 50% the percentage of non-viable chondrocytes 24 h post-injury in chondral explants exposed to 25 MPa of unconfined compression. There is a question whether these acutely 'saved' chondrocytes will continue to degrade over time, as P188 is only thought to act by acute repair of damaged cell membranes. In order to investigate the degradation of traumatized chondrocytes in the longer term, the current study utilized TUNEL staining to document the percentage of cells suffering DNA fragmentation with and without an immediate 24 h period of exposure of the explants to P188 surfactant. In the current study, as in the previous study by this laboratory, chondral explants were excised from bovine metacarpophalangeal joints and subjected to 25 MPa of unconfined compression. TUNEL staining was performed at 1 h, 4 days, and 7 days post-impact. The current study found that P188 was effective in reducing the percentage of cells with DNA fragmentation in impacted explants by approximately 45% at 4 and 7 days post-impact. These data suggest that early P188 intervention was effective in preventing DNA fragmentation of injured chondrocytes. The current hypothesis is that this process was mitigated by the acute repair of damaged plasma membranes by the non-ionic surfactant P188, and that most repaired cells did not continue to degrade as measured by the fragmentation of their DNA.
The TonE/TonEBP Pathway Mediates Tonicity-responsive Regulation of UT-A Urea Transporter Expression

The rat renal urea transporter UT-A includes four isoforms. UT-A1, UT-A3, and UT-A4 are transcribed from a single initiation site at the 5′-end of the gene; a distinct internal initiation site is used for UT-A2 transcription. We cloned 1.3 kilobases (kb) of the 5′-flanking region upstream of the transcription start site of UT-A1, UT-A3, and UT-A4. This region contains three CCAAT sequences but lacks a TATA motif. A tonicity-responsive enhancer (TonE) was identified at −377bp. The 1.3-kb full fragment subcloned into pGL3 vector induced luciferase activity in Madin-Darby canine kidney cells and in mouse inner medullary collecting duct cells in isotonic medium. Luciferase activity was increased significantly in hypertonic medium, whereas deletion or mutation of the TonE sequence abolished this response. Electrophoretic mobility shift assay using the 5′ UT-A TonE sequence as DNA probe showed formation of a specific DNA-protein complex with nuclear extracts from cells exposed to hypertonic medium and was weakly detectable in isotonic controls. A supershift in the mobility of the DNA-protein complex was observed with antiserum targeted to the TonE-binding protein (TonEBP). Co-transfection with dominant-negative TonEBP abolished the luciferase activity induced by the UT-A 1.3-kb construct under hypertonic and isotonic conditions. These data suggest that the TonE/TonEBP pathway mediates tonicity-responsive transcriptional regulation of UT-A1, UT-A3, and UT-A4 expression.
Effect of maximal work load on cardiac function.

The time course and mode of deterioration of the heart under prolonged maximal work load were studied in open-chest dogs, the hearts of which were loaded at maximal cardiac output while the aortic pressure was kept constant. During the period of loading, the maximal level of cardiac output that could be attained was relatively stable for 30min to 1 hour and then began to fall suddenly and rapidly. This terminal deterioration appeared to be caused by mechanical factors, possibly over-distention of the heart, rather than by fatigue of the muscle per se.
Meeting national cholesterol education goals in clinical practice : A comparison of lovastatin and fluvastatin in primary prevention$

The available clinical data for 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors demonstrate their efficacy and safety in treating hypercholesterolemia and improving long-term morbidity and mortality related to coronary artery disease. Comparative studies among agents in this class support the general perception that, at the most commonly prescribed doses, all these drugs reduce low-density lipoprotein (LDL) cholesterol levels by about 20-30%. The primary measure of efficacy in the current study was the percentage of patients achieving goal levels for LDL cholesterol of < 160 mg/dL, as proposed by the National Cholesterol Education Program (NCEP). This study compares the most widely prescribed agent in this class, lovastatin, with the newest agent, fluvastatin. Patients enrolled had previously been satisfactorily treated with lovastatin 20 mg every evening. Following a placebo washout period, patients were randomized to receive lovastatin 20 mg with the evening meal (69 patients) or fluvastatin 20 mg at bedtime (68 patients) for 4 weeks of open-label therapy. In a second 4-week period, patients on lovastatin continued on the initial dosage while patients receiving fluvastatin had their daily dosage increased to 40 mg at bedtime to evaluate the range of efficacy from 20-40 mg/day. In both treatment arms, the majority of patients achieved the goal lipid level. Approximately 85% of patients on fluvastatin 20 mg and 90% of patients on lovastatin 20 mg achieved the goal within 4 weeks. This small difference was not statistically significant. Increasing the dosage to 40 mg at bedtime in the fluvastatin arm produced goal LDL cholesterol levels in about 90% of patients. Both agents were well tolerated; no patients discontinued therapy because of adverse events.
Identification of Biofilm Matrix-Associated Proteins from an Acid Mine Drainage Microbial Community

In microbial communities, extracellular polymeric substances (EPS), also called the extracellular matrix, provide the spatial organization and structural stability during biofilm development. One of the major components of EPS is protein, but it is not clear what specific functions these proteins contribute to the extracellular matrix or to microbial physiology. To investigate this in biofilms from an extremely acidic environment, we used shotgun proteomics analyses to identify proteins associated with EPS in biofilms at two developmental stages, designated DS1 and DS2. The proteome composition of the EPS was significantly different from that of the cell fraction, with more than 80% of the cellular proteins underrepresented or undetectable in EPS. In contrast, predicted periplasmic, outer membrane, and extracellular proteins were overrepresented by 3- to 7-fold in EPS. Also, EPS proteins were more basic by ∼2 pH units on average and about half the length. When categorized by predicted function, proteins involved in motility, defense, cell envelope, and unknown functions were enriched in EPS. Chaperones, such as histone-like DNA binding protein and cold shock protein, were overrepresented in EPS. Enzymes, such as protein peptidases, disulfide-isomerases, and those associated with cell wall and polysaccharide metabolism, were also detected. Two of these enzymes, identified as β-N-acetylhexosaminidase and cellulase, were confirmed in the EPS fraction by enzymatic activity assays. Compared to the differences between EPS and cellular fractions, the relative differences in the EPS proteomes between DS1 and DS2 were smaller and consistent with expected physiological changes during biofilm development.
Antigen-driven T cell expansion: affinity rules.

TCR affinity and ligand off-rate have both been found to influence the degree of T cell activation by peptide-MHC. A report in this issue of Immunity (Malherbe et al., 2004) finds that ligand off-rate does not correlate with antigen-specific peripheral T cell expansion. Moreover, the data point to the surprising notion that there exist TCR affinity thresholds and, once attained, T cells with higher affinity receptors have no competitive advantage.
Programming language support for multicast communication in distributed systems

A spectrum of abstractions for multicast communications is introduced in increasing order of both desirability and semantic level: functional mapping, iterators, and streams. Examples of distributed algorithms from the literature are used to illustrate the expressive power of each mechanism. Streams, in particular, provide first-class status for multicast communication in progress and can be implemented efficiently in typical multicast communication architectures. Related work and the criteria for multicast support are discussed. The layers of a typical distributed system that are relevant to language support for multicast communication are discussed. >
Committed To Peace: Liberal Institutions and the Termination of Rivalry

Rivalry is characterized by mutual mistrust, anger and fear, and becomes increasingly intractable as confrontations between rivals militarize. The empirical record confirms that rivalries account for the vast number of militarized interstate disputes and wars in the international system. Although considerable attention has been spent on the initiation, duration or termination of rivalries, to date no comprehensive theoretical framework for their persistence or failure exists. Following Fearon, a rationalist explanation of rivalry termination is developed. It is argued here that the adoption of liberal institutions helps alleviate the commitment problems arising in rivalry. Free-market reform, democratic institutions and membership in international organizations all build trust and increase defection costs among rival states, and therefore help to shorten the duration of rivalry. Using a Cox proportional hazard model and Thompson's data on rivalries, it is shown that change towards democracy, as well as the joint effect of democracy and economic development increase the likelihood of rivalry termination. Also, joint membership in international organizations with mechanisms for dispute settlement reduces the duration of rivalry.Arobustness check using Diehl and Goertz's list of rivalries produces similar results.
Model and controller selection policies based on output prediction errors

Based on observations of the past inputs and outputs of an unknown system /spl Sigma/, a countable set of predictors, O/sub p/, p/spl isin/P, is used to predict the system output sequence. Using performance measures derived from the resultant prediction errors, a decision rule is to be designed to select a p/spl isin/P at each time /spl kappa/. We study the structure and memory requirements of decision rules that converge to some q/spl isin/P such that the qth prediction error sequence has desirable properties. In a very general setting we give a positive result that there exist stationary derision rules with countable memory that converge to a "good" predictor. These decision rules are robust in a sense made precise in the paper. In addition, we demonstrate that there does not exist a decision rule with finite memory that has this property. Based on the decision rule's selection at time /spl kappa/, a controller for the system /spl Sigma/ is chosen from a family /spl Gamma//sub p//spl isin/P of predesigned control systems. We show that for certain multi-input/multi-output linear systems the resultant closed-loop controlled system is stable and can asymptotically track an exogenous reference input.
Of passwords and people: measuring the effect of password-composition policies

Text-based passwords are the most common mechanism for authenticating humans to computer systems. To prevent users from picking passwords that are too easy for an adversary to guess, system administrators adopt password-composition policies (e.g., requiring passwords to contain symbols and numbers). Unfortunately, little is known about the relationship between password-composition policies and the strength of the resulting passwords, or about the behavior of users (e.g., writing down passwords) in response to different policies. We present a large-scale study that investigates password strength, user behavior, and user sentiment across four password-composition policies. We characterize the predictability of passwords by calculating their entropy, and find that a number of commonly held beliefs about password composition and strength are inaccurate. We correlate our results with user behavior and sentiment to produce several recommendations for password-composition policies that result in strong passwords without unduly burdening users.
Biographical Sketch: Royal Whitman, 1857–1946

This biographical sketch of Royal Whitman corresponds to the historic text, The Classic: A Study of the Weak Foot, with Reference to its Causes, its Diagnosis, and its Cure; with an Analysis of a Thousand Cases of So-Called Flat-Foot, available at DOI 10.1007/s11999-009-1130-1.
Towards natural polyploid model organisms.

Populations of natural allopolyploids with available and well-developed genomic resources are currently hard to come by. These are needed because whole genome duplication and hybridization — both combined in allopolyploids — are significant processes in evolution, especially the evolution of plants. The new characterization of a naturally occurring allopolyploid in the genus Mimulus by Sweigart et al. in this issue of Molecular Ecology is therefore to be welcomed. Mimulus is rapidly emerging as a model system for evolutionary functional genomics. Sequences of the whole genome and 200 000 expressed sequence tags of diploid M. guttatus, a putative parent of the polyploid described in this issue, will soon be available. These will facilitate investigation of the fates of genes duplicated by whole genome duplication, and their effects on morphology, mating system and ecology in natural populations.
Equilibrium water sorption characteristics of the human nail

The physical and transport properties of keratinized tissues are closely related to their water content. This report presents water uptake and desorption isotherms for the human nail and compares them with those of wool, horn, hair, and stratum corneum. Nail absorbed a maximum of approximately 0.3 g H(2)O/g dry tissue, with the shape and magnitude of the isotherm most closely resembling horn. Hysteresis between uptake and desorption was observed, similar to that of other keratins. The shape of the isotherms was adequately described by both the D'Arcy-Watt and Guggenheim-Anderson-deBoer (GAB) models; however, small positive deviations from both models were found in the relative humidity range, 30-60%. Directionally better fits to the data were found with the D'Arcy-Watt model. This analysis suggests that most of the water in the tissue was in a strongly bound state, consistent with observations made by other techniques.
Theory of pth-order inverses of nonlinear systems

The concept and theory of the p th-order inverse of a nonlinear system es developed in this article. The p th-order inverse, K_{(p)}^{-1} , of a system H is defined as a system for which the Volterra series of the system Q formed by the tandem connection of K_{(p)}^{-1} and H is Q[x]= x+ \Sigma_{n=p+1}^{\infty} Q_{n}[x] so that the 2nd through the p th-order Volterra operators of Q are zero. The necessary and sufficient conditions for the existence of K_{(p)}^{-1} are determined. It is shown that the p th-order pre-inverse of a system H is identical to its p th-order post-inverse. In addition, a synthesis of K_{(p)}^{-1} is obtained. The p th-order inverse offers an approach to the study of the system inverse, H^{-1} , since, as p \rightarrow \infty , K_{(p)}^{-1} becomes the Volterra series of H^{-1} . This approach is discussed and some applications with regard to nonlinear differential equations and nonlinear feedback systems are presented.
Interferometric Noise Characterization and Suppression in Optical CDMA Networks

A solution for suppressing multiple-access interference and incoherent interferometric noise in 2-D optical code-division multiple access (CDMA) networks is demonstrated using a dispersion-imbalanced loop mirror containing a 15-m heavily GeO2-doped fiber. From the experimental study of the degradation caused by noise, bit-error-rate (BER) measurements in a two-user system having coherent, partially coherent, and incoherent interferometric noise without the dispersion-imbalanced loop mirror exhibit error floors above BER = 10-6. Including the dispersion-imbalanced loop mirror before the receiver allows error-free transmission, and reduces the power penalty from the noise by 7 dB. The solution presented increases the receiver sensitivity and accentuates the flexibility of the optical CDMA networks.
Long Pulse Laser-Plasma Interactions

The absorption of intense laser light in plasmas with a long density scale length can be influenced by many different processes, ranging from collisional absorption to laser-driven instabilities. The mix of these coupling processes depends strongly on the collisionality of the plasma. Optimum coupling is obtained by the use of short wavelength laser light.
Influence of a neutral surface on polymer molecules in the vicinity of the surface

Monte Carlo simulations based on the rotational isomeric model are used to investigate the influence of a neutral surface on the structural and thermodynamic descriptors of polymethylene chains on and in the vicinity of the surface. For large chains, the results of the simulations are replicated by a properly scaled distribution based on a random walk with absorbing barriers. Accordingly, the affects noted for the trial polymethylene system may be extended to other molecules. The perturbations in the geometry of the chain were confined to the components of the various descriptors perpendicular to the surface; the radial components were unaffected by the neutral surfaces. The perturbations induced by the neutral surfaces extend to chains whose origins were within about , where is the perpendicular component of the mean square radius of gyration of an unperturbed chain. In contrast, the average bond conformation, the associated internal energy, and the variance of the internal energy distribution are unaffected by a neutral surface. The major thermodynamic effect is manifest through the entropy arising from the reductions in accessible chain configurations due to the neutral barrier.
Zero-voltage-switching (ZVS) two-stage approaches with output current sharing for 48 V input DC-DC converter

Low-voltage on-board DC-DC converters are increasingly required to have high efficiency and fast transient response. In this paper, two-stage DC-DC converter architecture is proposed to achieve fast transient response while operating at high efficiencies, which feature soft switching, self-current-sharing capability and simplified self-driven techniques for the synchronous rectifiers.
Partial Gene Deletion of Heart-Type Fatty Acid–Binding Protein Limits the Severity of Dietary-Induced Insulin Resistance

The aim of this study was to determine the contribution of heart-type fatty acid-binding protein (H-FABP) to glucose and long-chain fatty acid (LCFA) utilization in dietary-induced insulin resistance. We tested the hypothesis that H-FABP facilitates increases in LCFA flux present in glucose-intolerant states and that a partial reduction in the amount of this protein would compensate for all or part of the impairment. Transgenic H-FABP heterozygotes (HET) and wild-type (WT) littermates were studied following chow diet (CHD) or high-fat diet (HFD) for 12 weeks. Catheters were surgically implanted in the carotid artery and jugular vein for sampling and infusions, respectively. Following 5 days of recovery, mice received either a saline infusion or underwent a euglycemic insulin clamp (4 mU x kg(-1) x min(-1)) for 120 min. At 90 min, a bolus of 2-deoxyglucose and [125I]-15-(rho-iodophenyl)-3-R,S-methylpentadecanoic acid were administered to obtain indexes of glucose and LCFA utilization. At 120 min, skeletal muscles were excised for tracer determination. All HFD mice were obese and hyperinsulinemic; however, only HFD-WT mice were hyperglycemic. Glucose infusion rates during insulin clamps were 49 +/- 4, 59 +/- 4, 16 +/- 4, and 33 +/- 4 mg x kg(-1) x min(-1) for CHD-WT, CHD-HET, HFD-WT, and HFD-HET mice, respectively, showing that HET limited the severity of whole-body insulin resistance with HFD. Insulin-stimulated muscle glucose utilization was attenuated in HFD-WT but unaffected in HFD-HET mice. Conversely, rates of LCFA clearance were increased with HFD feeding in HFD-WT but not in HFD-HET mice. In conclusion, a partial reduction in H-FABP protein normalizes fasting glucose levels and improves whole-body insulin sensitivity in HFD-fed mice despite obesity.
Gangliosides depleted in plasma membrane are directed to internal membranes of rat hepatomas : evidence for a glycolipid sorting defect in hepatocarcinogenesis

Ganglioside compositions of plasma membrane fractions highly purified from rat liver and hepatomas by phase partitioning were compared with those of fractions composed of internal membranes, free of plasma membrane. With liver, 70-80% of the the lipid bound sialic acid were accounted for by a plasma membrane location. In hepatomas this percentage was reduced to 50-65%. More pronounced was the distribution of the simple monosialoganglioside GM3. In the hepatomas, 60-80% of the GM3 was found associated with internal membranes as compared to liver where only 35% of the GM3 was present in internal membranes. The findings suggest a glycolipid sorting defect in hepatocarcinogenesis where gangliosides, and especially monosialogangliosides, are diverted to internal membranes rather than being correctly transported to the cell surface. Since GM3 is synthesized exclusively in the Golgi apparatus of both liver and hepatomas, the basis for the sorting defect may reside in a functionally altered Golgi apparatus.
Fall risk in older adults: roles of self-rated vision, home modifications, and limb function.

Objectives: To assess direct effects of self-rated vision, home modifications, and limb functioning, and moderating effects of self-rated vision on change in functioning of upper and lower limbs on fall risk in older adults. Method: Logistic regression was used to analyze 2004 and 2006 waves of the Health and Retirement Study. Results: Effects of self-rated vision and home modifications in predicting falls decreased after controlling functioning in upper and lower extremities. Declines/gains in functioning across short periods of time superseded self-rated vision in predicting falls. No evidence was found for a moderating effect of vision status on limb functioning. Discussion: Poor self-rated vision may not be a good indicator of fall risk in older adults. Thus, for older adults with visual impairments, preserving residual limb functioning through exercise and activity has the important potential to reduce fall risk in addition to improving muscle and bone strength as well as improving balance and gait.
Emerging ethical issues in instructions to authors of high-impact biomedical journals

Public interest in issues concerning the maintenance of high ethical standards in the conduct of scientific research and its publication has been increasing. Some of the developments in these issues as reflected in the publication of the medical literature are traced here. This paper attempts to determine whether public interest is reflected in the specific requirements for authors for manuscript preparation as stated in the “Instructions to Authors” for articles being prepared for submission to 124 “high- impact” journals. The instructions to authors of these journals were read on the Web for references to ethical standards or requirements. The ethical issues that the instructions most often covered were specifically related to the individual journal's publication requirements. The results suggest that while the editors and publishers of the biomedical literature are concerned with promoting and protecting the rights of the subjects of the experiments in the articles they publish, and while these concerns are not yet paramount, they are evolving and growing.
Achieving Proposed Federal Concentrations using Reduced Specimen Volume for the Extraction of Amphetamines from Oral Fluid

This article details the rapid extraction of amphetamines from oral fluid using low specimen volume, low sorbent bed mass, and fast gas chromatography with mass selective detection. The collection of a known amount of sample volume coupled with high percentage recovery of drug from the collection pad has allowed oral fluid to be increasingly employed as the specimen of choice for the detection of drug use in various applications. Additionally, low specimen volume for confirmation is required, so that adequate test volume remains for second analysis in case of batch failure or for testing at a different laboratory facility. The extracts were prepared using low bed mass sorbent, so less conditioning, washing, and elution solvent further reduced the overall cost of sample preparation. The limits of quantitation for the assay were 25 ng/mL; the intraday precision of the assays (n = 5) ranged from 0.3 to 3.99%; interday precision ranged from 0.72 to 4.6% for the amphetamine class. The percentage recovery of the drugs from the collection pads ranged from 85.4 to 89.1% (n = 6). The process lends itself to widely available automated processing instrumentation and significantly increases the efficiency of laboratories providing high-volume oral fluid analysis for drugs of abuse.
Shortest path optimization under limited information

The problem of finding an optimal path in an uncertain graph arises in numerous applications, including network routing, path-planning for vehicles, and the control of finite-state systems. While techniques in robust and stochastic programming can be employed to compute, respectively, worst-case and average-optimal solutions to the shortest-path problem, we consider an alternative problem where the agent that traverses the graph can request limited information about the graph before choosing a path to traverse. In this paper, we define and quantify a notion of information that is compatible to this performance-based framework, bound the performance of the agent subject to a bound on the capacity of the information it can request, and present algorithms for optimizing information.
Activities of three quinolones, alone and in combination with extended-spectrum cephalosporins or gentamicin, against Stenotrophomonas maltophilia.

The present study examined the activities of trovafloxacin, levofloxacin, and ciprofloxacin, alone and in combination with cefoperazone, ceftazidime, cefpirome, and gentamicin, against 100 strains of Stenotrophomonas maltophilia by the MIC determination method and by synergy testing of the combinations by the time-kill and checkerboard titration methods for 20 strains. The respective MICs at which 50% and 90% of isolates were inhibited for the drugs used alone were as follows: trovafloxacin, 0.5 and 2.0 mg/ml; levofloxacin, 2.0 and 4.0 mg/ml; ciprofloxacin, 4.0 and 16.0 mg/ml; cefoperazone, >128.0 and >128.0 mg/ml; ceftazidime, 32.0 and >128.0 mg/ml; cefpirome, >128.0 and >128.0 mg/ml; and gentamicin, 128.0 and >128.0 mg/ml. Synergistic fractional inhibitory concentration indices ( 50% of strains for trovafloxacin-cefoperazone, trovafloxacin-ceftazidime, levofloxacin-cefoperazone, levofloxacin-ceftazidime, ciprofloxacin-cefoperazone, and ciprofloxacin-ceftazidime, with other combinations affecting fewer strains. For 20 strains tested by the checkerboard titration and time-kill methods, synergy (>100-fold drop in count compared to the count achieved with the more active compound) was more pronounced after 12 h due to regrowth after 24 h. At 12 h, trovafloxacin at 0.004 to 0.5 mg/ml showed synergy with cefoperazone for 90% of strains, with ceftazidime for 95% of strains with cefpirome for 95% of strains, and with gentamicin for 65% of strains. Levofloxacin at 0.03 to 0.5 mg/ml and ciprofloxacin at 0.5 to 2.0 mg/ml showed synergy with cefoperazone for 80% of strains, with ceftazidime for 90 and 85% of strains, respectively, with cefpirome for 85 and 75% of strains, respectively, and with gentamicin for 65 and 75% of strains, respectively. Time-kill assays were more discriminatory than checkerboard titration assays in demonstrating synergy for all combinations.
Methods of Studying Higher Mental Functions

The methodology of the contemporary psychological experiment is closely tied to the general major problems of psychological theory and, in the last analysis, is always only a reflection of how the most important problems of psychology were solved. Specifically for this reason, criticism of the basic views of the essence and development of mental processes must of necessity also involve a review of the basic positions related to research methodology.
Challenges for conservation and sustainable use in North America

Conservation will only increase as a focus for governments in the 21st century. Canada and the United States have been successful in conserving wildlife and habitats over the past 100 years through the North American Model of Wildlife Conservation. This approach is not universally accepted, however, and there are challenges to sustainable use practices such as hunting and fishing. Herein, we discuss seven of the biggest challenges to conservation worldwide: an increasing human population; globalization; urbanization and the human-nature divide; novel ecosystems; connectivity; funding, fragility and resilience; and abundance and superabundance. We then relate these to the North American context.
Medical treatment of aortic stenosis: promising, or wishful thinking?

Valvular aortic stenosis (AS) is a prevalent condition and one of the most common indications for valve replacement surgery. Although AS can be congenital in etiology or a consequence of rheumatic fever, the most common form is “calcific” AS. Calcific AS is usually seen in patients over the age
Singular behavior of jet substructure observables

Jet substructure observables play a central role at the Large Hadron Collider for identifying the boosted hadronic decay products of electroweak scale resonances. The complete description of these observables requires understanding both the limit in which hard substructure is resolved, as well as the limit of a jet with a single hard core. In this paper we study in detail the perturbative structure of two prominent jet substructure observables, $N$-subjettiness and the energy correlation functions, as measured on background QCD jets. In particular, we focus on the distinction between the limits in which two-prong structure is resolved or unresolved. Depending on the choice of subjet axes, we demonstrate that at fixed order, $N$-subjettiness can manifest myriad behaviors in the unresolved region: smooth tails, end point singularities, or singularities in the physical region. The energy correlation functions, by contrast, only have nonsingular perturbative tails extending to the end point. We discuss the effect of hadronization on the various observables with Monte Carlo simulation and demonstrate that the modeling of these effects with nonperturbative shape functions is highly dependent on the $N$-subjettiness axes definitions. Our study illustrates those regions of phase space that must be controlled for high-precision jet substructure calculations, and emphasizes how such calculations can be facilitated by designing substructure observables with simple singular structures.
Detection of circulating hypoxia-regulated miR-210 in pancreatic adenocarcinoma patients

4624 Background: MicroRNAs (miRs) are small non-coding transcripts involved in many cellular mechanisms, including tumorigenesis. miR-210, in particular, has been shown to be induced by hypoxia, ov...
Human calcitonin receptor is directly targeted to and retained in the basolateral surface of MDCK cells

The human calcitonin receptor (hCTR) is expressed in polarized cells of the kidney, bone, and nervous system. In the kidney, hCTRs are found in cells of the distal nephron to which blood-borne calcitonin has access only at the basolateral surface. We expressed hCTR subtypes 1 and 2 in Madin-Darby canine kidney (MDCK) cells to establish a cell model useful for delineating the molecular mechanisms underlying hCTR polarity. Selective cell surface incubation demonstrated functional polarity of hCTRs by equilibrium binding or cross-linking of radioiodinated salmon calcitonin (125I-sCT) and cAMP accumulation stimulated by sCT. We estimated that at the steady state there are 40-fold more hCTRs on the basolateral than on the apical side. Domain-selective cell surface biotinylation followed by immunoblotting of streptavidin-agarose-fractionated biotinylated glycoproteins independently confirmed the polarized distribution of FLAG epitope-tagged hCTR-2 in the basolateral domain. Confocal microscopy of immunostained receptors revealed that hCTRs are concentrated on a lateral subdomain of the basolateral membrane. Cell surface arrival assay of newly formed receptors demonstrated that direct delivery to the basolateral domain is the mechanism by which hCTRs become polarized. Measurement of receptor turnover on the basolateral surface showed that retention contributes to hCTR distribution at the steady state.
Giant-cell tumors treated by cryosurgery. A report of twenty-five cases.

Cryosurgery combined with a routine "second look" biopsy is a promising modality of treating giant-cell tumors of bone. Clearly malignant tumors are not considered suitable for this treatment. While complications such as infection, fracture, and delayed union occurred, it was possible to eradicate tumors while preserving joint motion and avoiding amputations in a far greater percentage of cases than has been possible with former methods.
Measured operating characteristics of a rectangular combustor/inlet isolator

Data characterizing the performance of a rectangular constant area combustor/inlet isolator duct were obtained in semifreejet tests of a scramjet engine model. Isolators ducts have been previously demonstrated to be an effective mechanism for stabilizing combustion induced disturbances and preventing combustor/inlet interactions. The current database for shock structures in rectangular ducts, however, is insufficient for designing isolators for high speed (Mach 4-10) propulsion systems. This report is intended to contribute to that database and discuss the shortcomings of acquiring isolator data in a multi-component engine test. A comparison is made with an empirical correlation that characterizes shocks in cylindrical ducts to determine its applicability to this rectangular isolator. Measurements used to make this comparison include boundary layer and core flow pitot pressures, total temperature, wall heat transfer, air flow rate, and axial pressure distributions.
Tearing Down the Fetal Tissue Smokescreen

Although congressional investigations have found no evidence of wrongdoing by Planned Parenthood, to continue to advance women's health, the organization will no longer accept any reimbursement for expenses involved in donating fetal tissue for research.
Neuromodulation in intractable pain management: outcomes and predictors of revisions of spinal cord stimulators

OBJECTIVE Spinal cord stimulators (SCSs) appear to be safe and efficacious for chronic intractable back pain. Although there are many reports on percutaneous SCSs, there are very few studies on outcomes of paddle lead SCSs. In addition, the predictors of requirement for SCS revision have not been well established. Here, the authors review the outcome of a case series and attempt to identify the predictors of SCS revisions. METHODS The clinical and radiological information of 141 patients with intractable chronic pain who underwent SCS implantation within the past 20 years was retrospectively reviewed. Paddle lead SCSs were used in this series. Statistical analysis was conducted using Kaplan-Meier curves and Cox proportional-hazards regression. RESULTS Among 141 cases, 90 (64%) did not require any revision after SCS implantations. Removal of the SCS was required in 14 patients. The average pain score was significantly reduced (preimplantation score of 8 vs postimplantation score of 1.38; p < 0.0001). Younger age, male sex, obesity, a preimplantation pain score ≥ 8, and the presence of neuromuscular pain were identified as predictors of the overall requirement for SCS revision. However, only a preimplantation pain score ≥ 8 was identified as a predictor of early failure of the SCS. CONCLUSIONS Implantation of a paddle lead SCS is a relatively less invasive, safe, and effective procedure for patients with intractable back pain. Revision of the procedure depends on many factors, including younger age, male sex, associated neuromuscular pain, and severity of the pain. Therefore, patients with these factors, for whom implantation of an SCS is planned, should be closely followed for the possible requirement for revision.
Structure and Dynamics of Branched (Epoxy) Polymers and Kinetics of Its Polymerization Process

Laser light scattering (LLS) and small-angle x-ray scattering (SAXS) studies have been made of the curing of epoxy resins from 1,4-butanediol diglycidyl ether with cis-1,2-cyclohexanedicarboxylic anhydride. The epoxy resin before its gelation threshold is soluble in methyl ethyl ketone, and scattering techniques can be used to determine the weight-average molecular weight (Mw), the fractal dimension (df), and the molecular weight distribution (MWD) of the branched epoxy polymer during each stage of the initial polymerization process. The MWDs obtained from LLS were compared with those determined by conventional size exclusion chromatography (SEC). From the comparison, we were able to develop a new absolute calibration procedure for SEC of specific branched polymers. By investigating the LLS envelope of the three-dimensional crosslinking process near and pass the gelation threshold and by applying the Debye-Bueche theory of light scattering for inhomogeneous solids, the structural changes of the branched epoxy polymer during the curing process could be evaluated. The change in the correlation length (a) and the mean squared average of local dielectric constant fluctuations (η −2) could be divided into four main stages. Finally, The branching kinetics of the copolymerization reaction could be approximated by using Smoluchowski’s coagulation equation.
Bacon's Rebellion: Mere Insurrection or Abortive Revolution?

Students of history often think of the American Revolution in terms of the causes of the outbreak of war in 1775: the Stamp, Sugar and Quartering Acts, the Boston Tea party, and the Intolerable Acts of 1774. The ideas of oppressive taxation, taxation without representation, restraints on trade and limited freedoms, all factors which precipitated important political reforms, were surely on the minds of colonial revolutionaries at the time.However, a small but heated debate has transpired over a series of events that took place in 1676 referred to as Bacon’s Rebellion. Taking its name from its leader Nathaniel Bacon, the rebellion is usually considered the first popular uprising of organized resistance in colonial America. The debate continues over whether Bacon’s Rebellion had democratic aims or was simply an illegal attempt to seize land and power in Virginia. Quite possibly, the American Revolution may not have started in Concord and Lexington in 1775, but almost one hundred years earlier in Virginia, by Nathaniel Bacon. The political reforms of Bacon’s Rebellion, as those of the American Revolution, laid the groundwork for democracy.
Comparison of three methods for determination of N-nitrosopyrrolidine in fried dry-cured bacon

The recently developed Eastern Regional Research Center ( ERRC ) dry column chromatographic procedure for determining N-nitrosopyrrolidine (NPYR) in fried cure-pumped bacon was evaluated for its applicability to fried dry-cured bacon. The method was then compared with 2 established procedures for volatile nitrosamine analysis in cured meat products: the multidetection thermal energy analyzer (MD) method and the mineral oil distillation (MOD) screening procedure. No significant difference (P less than 0.05) in NPYR values was found between the ERRC and MD procedures, but significant differences were found between the ERRC and MOD procedures and between the MOD and MD procedures. No artifactual nitrosamine formation was found in the ERRC procedure, but significant amounts were found in samples analyzed by the MOD procedure. The ERRC method was demonstrated to be rugged and very rapid. It is proposed that the ERRC method replace the MOD method as the official screening procedure for NPYR in fried bacon.
In Patients with Celiac Artery Compression Syndrome, Does Surgery Improve Quality of Life?

Symptomatic celiac artery compression is a controversial diagnosis that should be considered in patients with chronic abdominal pain of unknown etiology despite an extensive medical evaluation. Once suspected, patients should undergo screening mesenteric duplex. Diagnosis is confirmed with the findings of elevated celiac artery velocities which normalize with respiration followed by CT angiogram showing the typical “J-hook” conformation of the celiac artery. Patients should then undergo evaluation by a multi-disciplinary team to appropriately select patients for surgical treatment. Surgical options include release of the median arcuate ligament, with or without neurolysis of the celiac nerve plexus, and with or without concomitant revascularization procedures. Approaches can be open, laparoscopic, robotic, or retroperitoneal. Surgical treatment has an overall success rate with 70–80 % patients reporting improved abdominal pain and quality of life. Post-operatively, patients can have persistent or recurrent abdominal pain and should undergo re-evaluation for possible need for revascularization procedure for stenosis of the celiac artery or celiac plexus block if the celiac artery is normalized. Additionally, some of these patients will have persistent pain consistent with a functional gastrointestinal disorder that will then require medical management.