cssi/SciSciGPT-SciSciNet huggingface dataset:
Loss of a right radial arterial pressure tracing during thoracic aortic aneurysm repair

C ONTINUAL measurement of the arterial blood pressure is an essential component of monitoring during anesthesia. 1 In most cardiovascular procedures, effective control of the hemodynamic state requires contmuous measurement of the arterial blood pressure by direct cannulation of a peripheral artery. In thoracic aortic surgery, the challenge is to find a peripheral artery that will provide for continuous arterial blood pressure during the period the aorta will be cross-clamped. Generally, the right radial artery is preferred during the repair of descending aortic aneurysms because it may be necessary to crossclamp the aorta above the origin of the left subclavian artery, thereby eliminating blood flow to the left radial artery. 2 The authors encountered a patient who had a right radial arterial catheter in place during a descending thoracic aortic aneurysm repair, but the pressure tracing was lost during clamping of the aorta proximal to the left subclavian artery. In this report, the possible causes of this phenomenon and the management are described.
Heparinless partial cardiopulmonary bypass for the repair of aortic trauma.

Abstract Objective: We hypothesized that partial cardiopulmonary bypass with a heparin-bonded system would be a technically simple, effective adjunct for reducing paraplegia during repair of traumatic aortic rupture. It avoids the risk of heparin, but, unlike left atrial–arterial bypass, it can heat, cool, oxygenate, and rapidly infuse volume if needed. Methods: A retrospective review was conducted of patients admitted for aortic trauma from July 1994 to December 1999. Bypass consisted of femoral venous (right atrial) cannulation, a centrifugal pump, and an oxygenator-heater/cooler. Arterial return was to the femoral artery or distal aorta. The entire system was heparin-bonded and no systemic heparin was given. Results: Heparin-bonded partial bypass was established in 50 patients (mean age 43 ± 17 years). Crossclamp time was 32 ± 11 minutes (range 14–70 minutes), mean flow 3.0 ± 0.8 L/min, and bypass time 64 ± 43 minutes. During repair, 58% of patients received volume through the system (mean 1.1 ± 1.9 L). Core temperature rose slightly (35.9°C ± 0.7°C to 36.3°C ± 0.8°C). Three of the 15 patients who underwent percutaneous femoral arterial and venous cannulation concomitant with their angiograms had vessel injury, with one limb loss, and this procedure was discontinued. Thirty-five patients underwent percutaneous femoral vein and direct distal aortic cannulation without event. The mortality rate for patients supported by bypass was 10%, and all deaths were due to other injuries. There were no new cases of paraplegia and no worsening of intracranial or pulmonary injuries. Conclusions: Heparin-bonded bypass is technically simple to use and avoids the risk of anticoagulation. Paraplegia was avoided. The ability to correct hypothermia, oxygenate, and rapidly infuse volume may simplify management and improve outcomes. (J Thorac Cardiovasc Surg 2000;120:1104-11)
1H, 15N, 13C and 13CO resonance assignments and secondary structure of villin 14T, a domain conserved among actin-severing proteins

Sequence-specific assignments have been made for the 1H, 15N, 13C and 13CO resonances of 14T, the 126-residue amino-terminal domain of the actin-severing protein villin. Villin is a member of a family of proteins that regulate cytoskeletal actin by severing, capping and nucleating actin filaments. Actin binding is dependent on calcium and disrupted by phosphatidyl inositol 4,5-bisphosphate. Actin-severing proteins are built from three or six repeats of a conserved domain, represented by 14T. Expression in Escherichia coli facilitated incorporation of 15N and 13C isotopes and application of triple-resonance, backbone-directed strategies for the sequential assignments. Elements of regular secondary structure have been identified by characteristic patterns of NOE cross peaks and values of vicinal 3JH n Hα coupling constants. Amide protons that exchange slowly (rates less than 1.0×10-4 per min) are concentrated in the central β-sheet and the second and third α-helices, suggesting that these elements of secondary structure form very stable hydrogen bonds. Assignments for the amide nitrogens and protons have been examined as a function of pH and calcium concentration. Based on the conservation of chemical shifts in the core of the domain, villin 14T maintains the same overall fold in the pH range from 4.15 to 6.91 and the calcium range from 0 to 50 mM. The calcium data indicate the presence of two calcium-binding sites and suggest their locations.
NITROGEN FLOW THROUGH THE FOOD WEB IN THE OLIGOHALINE ZONE OF A NEW ENGLAND ESTUARY

We introduced tracer levels of 15N-enriched nitrate into the oligohaline reach of the Parker River estuary (Massachusetts, USA) to study the transformation and fate of watershed-derived nitrogen during the biologically productive summer period. Intensive temporal and spatial measurements were made of the isotopic label in a wide range of organisms during the 15N amendment and for 2 mo thereafter. The tracer helped determine the relative trophic importance of three major sources of organic nitrogen supporting the food web of the upper Parker River estuary: planktonic and benthic primary producers, and detritus derived mostly from the surrounding marsh. The planktonic centric diatom Actinocyclus normanii was the primary vector of tracer nitrogen to benthic and water-column organisms. Fauna that attained the highest 15N-tracer content (planktonic copepods, planktivorous juvenile fishes, several macrofaunal crustaceans) derived a major part of their incorporated nitrogen (∼50% or more) from the bloom-forming ...
Polymeric nanofibers: isodiametric design space and methodology for depositing aligned nanofiber arrays in single and multiple layers

STEP Isodiametric design space based deposition of polymeric micro/nanofibers in hierarchical multi-layer assemblies with control on fiber diameter, spacing and orientation.
Y-90 radioembolization of primary and metastatic soft tissue sarcomas of the liver

Purpose Soft tissue sarcomas (STS) are a group of uncommon neoplasms that are difficult to treat when unresectable. We present our initial data on Y-90 radioembolization (RE) of STS, both primary and metastatic to the liver. Materials and Methods Between November 2006 and June 2012, 11 patients with primary and metastatic STS involving the liver underwent 12 Y-90 RE treatments. Nine of 11 (81.8%) patients had prior unsuccessful treatments to control tumor progression in the liver including systemic chemotherapy, surgery, and locoregional therapies such as bland embolization or RFA. Eleven treatments were with resin and 1 treatment was with glass microspheres. Eight were whole liver treatments, and 4 were single lobar treatments. Sarcomas treated were 4 metastatic leiomyosarcomas (abdominal, retroperitoneal, uterine, and lower extremity in origin), 3 metastatic hemangiopericytomas, 1 metastatic prostatic rhabdomyosarcoma, 1 metastatic pleomorphic spindle cell sarcoma, 1 primary hepatic sarcoma, and 1 primary epithelioid hemangioendothelioma. Clinical and biochemical toxicities were recorded at baseline, 2 weeks, 4 weeks, and every 4 weeks thereafter. Radiographic response was recorded every 3 months. Results The median dose delivered was 1.68 GBq. The most common toxicities encountered were self-limited grade 1 fatigue in 6/11 (54.5%) and grade 1 abdominal pain in 4/11 (36.4%) patients. Follow up imaging was available in 11 cases. Partial (PR) or complete response (CR) was seen in 8/11 (72.7%) and 9/11 (81.8%) patients at 3 and 6 month imaging, respectively, according to mRECIST criteria. CRs were seen in 2 hemangiopericytomas, 1 uterine leiomyosarcoma, and 1 primary hepatic sarcoma. Median overall survival was 261 days with 5 (45.5%) patients surviving 491 days or longer. Two patients died within 50 days of treatment, though hepatic disease was not the cause of death in either patient. Conclusion Y-90 RE of advanced primary or metastatic STS of the liver appears to be a promising treatment option for patients who are poor surgical candidates or refractory to other salvage therapies.
Imprint of sub-25 nm vias and trenches in polymers

A nanoimprint process that presses a mold into a thin thermoplastic polymer film on a substrate to create vias and trenches with a minimum size of 25 nm and a depth of 100 nm in the polymer has been demonstrated. Furthermore, the imprint process has been used as a lithography process to fabricate sub‐25 nm diameter metal dot arrays of a 100 nm period in a lift‐off process. It was found that the nanostructures imprinted in the polymers conform completely with the geometry of the mold. At present, the imprinted size is limited by the size of the mold being used; with a suitable mold, the imprint process should mold sub‐10 nm structures with a high aspect ratio in polymers. The nanoimprint process offers a low cost method for mass producing sub‐25 nm structures and has the potential to become a key nanolithography method for future manufacturing of integrated circuits and integrated optics.
The effect of general anesthetics on the proton and potassium permeabilities of liposomes

The pump-leak hypothesis of general anesthesia proposes that anesthetics act by increasing the functional proton permeability of membranes, particularly those of synaptic vesicles. Since transmembrane proton gradients are required for neurotransmitter accumulation, decay of such gradients by an uncompensated anesthetic-induced leak would result in loss of neurotransmitter from the vesicles, followed by synaptic block and anesthesia. We have tested this hypothesis by determining the effect of four different general anesthetics on the relative permeabilities of liposome membranes to protons and potassium ions. In all cases, physiologically relevant levels of anesthetics caused a 200 to 500 percent increment in ionic permeability. There was no marked preference for protons, suggesting that the anesthetics did not induce a leak specific for this ionic species. Instead the anesthetics appeared to produce a more general defect available to both protons and potassium ions which resulted in a functional increment in proton permeability. These observations were compared with available data on proton transport rates by synaptic vesicle ATPase enzymes. The magnitude of the anesthetic-induced leak could not be compensated by the ATPase, which is only capable of a 40 percent increase in rate when uncoupled. We consider these results to be consistent with the pump-leak hypothesis.
Sirolimus as primary immunosuppression is effective in attenuating progression of cardiac-allograft vasculopathy.

Sirolimus as primary immunosuppression is effective in attenuating progression of cardiac-allograft vasculopathy
37-Year-Old Woman With Progressive Fatigue, Syncope, and Chest Pain

A 37-year-old woman was referred to Hermann Hospital from a local health maintenance organization clinic for the evaluation of fatigue, chest pain, and syncope. The patient was in her normal state of health until approximately 6 months before admission, when she began suffering mild fatigue. Her fatigue initially consisted of effort intolerance. She reported having an increased amount of breathlessness when climbing the flight of stairs to her second-floor apartment. Approximately 4 months before her hospital admission, she had the first of four syncopal episodes. The first episode occurred as she proceeded to walk after a long period of standing. At that time, she sensed the onset of chest tightness and dizziness before losing consciousness. She did not initially seek medical attention for her fatigue and syncope. She reported having dizzy spells that were initially associated with chest tightness and mild breathlessness. Her dizzy spells, which initially occurred weekly, became more frequent such that they occurred daily during the month before her hospital admission. Her chest discomfort was described as a squeezing sensation that was substernal in location without radiation to any other position. It was usually associated with dizziness and breathlessness but never with nausea, vomiting, or diaphoresis. Her chest discomfort occurred at rest and with exertion. The three syncopal episodes that followed the first occurred approximately 1 month apart. Each of these episodes occurred as she proceeded to stand and walk from a sitting or lying position. Her syncope was always preceded by substernal chest pressure, dizziness, and breathlessness. The patient is employed as a school bus driver. She reported having symptoms of dizziness and near syncope frequently while driving the bus. There was a history of smoking for approximately 10 years, averaging a …
Genome-Wide Characterization of Pancreatic Adenocarcinoma Patients Using Next Generation Sequencing

Pancreatic adenocarcinoma (PAC) is among the most lethal malignancies. While research has implicated multiple genes in disease pathogenesis, identification of therapeutic leads has been difficult and the majority of currently available therapies provide only marginal benefit. To address this issue, our goal was to genomically characterize individual PAC patients to understand the range of aberrations that are occurring in each tumor. Because our understanding of PAC tumorigenesis is limited, evaluation of separate cases may reveal aberrations, that are less common but may provide relevant information on the disease, or that may represent viable therapeutic targets for the patient. We used next generation sequencing to assess global somatic events across 3 PAC patients to characterize each patient and to identify potential targets. This study is the first to report whole genome sequencing (WGS) findings in paired tumor/normal samples collected from 3 separate PAC patients. We generated on average 132 billion mappable bases across all patients using WGS, and identified 142 somatic coding events including point mutations, insertion/deletions, and chromosomal copy number variants. We did not identify any significant somatic translocation events. We also performed RNA sequencing on 2 of these patients' tumors for which tumor RNA was available to evaluate expression changes that may be associated with somatic events, and generated over 100 million mapped reads for each patient. We further performed pathway analysis of all sequencing data to identify processes that may be the most heavily impacted from somatic and expression alterations. As expected, the KRAS signaling pathway was the most heavily impacted pathway (P<0.05), along with tumor-stroma interactions and tumor suppressive pathways. While sequencing of more patients is needed, the high resolution genomic and transcriptomic information we have acquired here provides valuable information on the molecular composition of PAC and helps to establish a foundation for improved therapeutic selection.
Minimizing selection bias in randomized trials: A Nash equilibrium approach to optimal randomization☆

Abstract Randomized trials can be compromised by selection bias, particularly when enrollment is sequential and previous assignments are unmasked. In such contexts, an appropriate randomization procedure minimizes selection bias while satisfying the need for treatment balance. This paper presents optimal randomization mechanisms based on non-cooperative game theory and the statistics of selection bias. For several different clinical trial examples, we examine subgame-perfect Nash equilibrium, which dictates a probability distribution on suitable assignment sequences. We find that optimal procedures do not involve discrete uniform distributions, because minimizing predictability is not equivalent to minimizing selection bias.
The pressure dependence of creep

Abstract We have determined the rheology of polycrystalline olivine, (Mg, Fe)2SiO4, at high temperature and very high pressure. Over this interval of pressure and temperature, the activation parameters for creep change significantly. Nevertheless, at constant homologous temperature, the pressure dependence of the flow stress vanishes. We present here a generalization of previous attempts to normalize creep data to the melting curve. We conclude that ΔV ∗ need have no simple relationship to the volume of any particular atom or group of atoms and that the correlation of the pressure dependence of creep with the pressure dependence of melting need not necessarily imply diffusion control of creep.
The personalisation of the British National Health Service: empowering patients or exacerbating inequality?

In the NHS Next Stage Review, a report by Lord Ara Darzi commissioned by the Department of Health, it has been declared that, from April 2010, every healthcare provider working for or on behalf of the National Health Service (NHS) will be required to publish performance data in online 'Quality Accounts' (1,2); information relating to both clinical outcomes and patient satisfaction will be displayed on the NHS website, allowing patients to make an informed choice about where they are treated. However, not all patients are capable of exercising this choice. In the same manner as other market-based NHS reforms aimed at empowering patients, choice seems likely to exacerbate inequality and thus once again threaten the viability of the NHS as a collectivist service (3,4).
Signal-dependent and -independent Degradation of Free and NF-κB-bound IκBα

A family of inhibitory IκB molecules regulates the activation of the transcription factor NF-κB. One member of the IκB family, IκBα, plays a major role in the rapid signal-induced activation of NF-κB. IκBα itself is transcriptionally regulated by NF-κB allowing for a tight autoregulatory loop that is both sensitive to and rapidly influenced by NF-κB activating stimuli. For this pathway to remain primed both for rapid activation of NF-κB in the presence of signal and then to suppress NF-κB activation once that signal is removed, IκBα must be exquisitely regulated. The regulation of IκBα is mainly accomplished through phosphorylation, ubiquitination, and subsequent degradation. The mechanism(s) that regulate IκBα degradation needs to be able to target IκBα for degradation in both its NF-κB bound and free states in the cell. In this study, we utilize a full-length IκBα mutant that is unable to associate to RelA/p65. We show that the signal-induced IκB kinase (IKK) phosphorylation sites on IκBα can only significantly influence the regulation of signal-dependent but not signal-independent turnover of IκBα. We also demonstrate that the constitutive carboxyl-terminal casein kinase II phosphorylation sites are necessary for the proper regulation of both signal-dependent and -independent turnover of IκBα. These findings further elucidate how the phosphorylation of IκBα influences the complex regulatory mechanisms involved in maintaining a sensitive NF-κB pathway.
Localization of fodrin during fertilization and early development of sea urchins and mice.

Abstract Fodrin, a spectrin-like protein, is localized in gametes, zygotes, and embryos from sea urchins and mice. Mammalian fodrin comprises two polypeptides with molecular weights of approximately 240 kDa (alpha) and 235 kDa (beta). An antibody specific for mammalian α-fodrin cross-reacted with a 240-kDa polypeptide from sea urchin egg extracts. This indicates that sea urchins contain a protein of similar electrophoretic mobility and immunological properties to mammalian α-fodrin. When this antibody was used to stain the sea urchin gametes with indirect immunofluorescence, fodrinspecific fluorescence was localized to the acrosome of the sperm and was distributed over the entire egg near the surface in a punctate pattern similar to the distribution of polymeric actin. During sperm incorporation, the fodrin-specific fluorescence is found at the site of sperm incorporation, in the fertilization cone. After fertilization, the intensity of fodrin fluorescence increases. During mitosis and cytokinesis in sea urchins, the entire surface of the egg remains stained; the cleavage furrow also was stained but no more intensely than was the rest of the egg surface. Antibody labeling with colloidal gold followed by electron microscopy showed that fodrin was loated in the cytoplasm immediately beneath the plasma membrane. In unfertilized mouse oocytes, both actin and fodrin were stained most intensely beneath the membrane adjacent to the meiotic spindle. After insemination, the cell surfaces of the pronucleate egg and the second polar body were stained; however, the actin matrix surrounding the apposed pronuclei did not bind the fodrin antibody. During cytokinesis in the mouse, the cleavage furrow stained more intensely than did the rest of the egg cortex, and in embryos the cell borders were delineated. These results indicate that organisms as unrelated to mammals as sea urchins have fodrin-like proteins; the rearrangements of such proteins suggest that they participate in the actin-mediated events at the cell surface during fertilization and early development in both mice and sea urchins.
Vertical Ionization Potentials of Nucleobases in a Fully Solvated DNA Environment

Vertical ionization potentials (IPs) of nucleobases embedded in a fully solvated DNA fragment (12-mer B-DNA fragment + 22 sodium counterions + 5760 water molecules equilibrated to 298 K) have been calculated using a combined quantum mechanical molecular mechanics (QM/MM) approach. Calculations of the vertical IP of the anion Cl(-) are reported that support the accuracy of the application of a QM/MM method to this problem. It is shown that the pi nucleotide HOMO origin for the emitted electron is localized on the base by the hydration structure surrounding the DNA in a way similar to that recently observed for pyrimidine nucleotides in aqueous solutions (Slavicek, P.; et al. J. Am. Chem. Soc. 2009, 131, 6460). In a first step, a high level of theory, CCSD(T)/aug-cc-pVDZ, was used to calculate the vertical IP of each of the four single bases isolated in the QM region while the remaining DNA fragment, counterions, and water solvent molecules were included in the MM region. The calculated vertical IPs show a large positive shift of 3.2-3.3 eV compared to the corresponding gas-phase values. This shift is similar for all four DNA bases. The origin of the large increase in vertical IPs of nucleobases is found to be the long-range electrostatic interactions with the solvation structure outside the DNA helix. Thermal fluctuations in the fluid can result in IP changes of roughly 1 eV on a picosecond time scale. IPs of pi-stacked and H-bonded clusters of DNA bases were also calculated using the same QM/MM model but with a lower level of theory, B3LYP/6-31G(d=0.2). An IP shift of 4.02 eV relative to the gas phase is found for a four-base-pair B-DNA duplex configuration. The primary goal of this work was to estimate the influence of long-range solvation interactions on the ionization properties of DNA bases rather than provide highly precise IP evaluations. The QM/MM model presented in this work provides an attractive method to treat the difficult problem of incorporating a detailed long-range structural model of physiological conditions into investigations of the electronic processes in DNA.
Plasma progesterone in snakes.

Abstract 1. 1. Using gas-liquid chromatography and protein binding techniques, progesterone is identified and quantitated as a component of reptilian plasma for the first time. 2. 2. Values obtained by both methods of quantitation were not significantly different. 3. 3. Plasma progesterone levels reflect the reproductive stage of the animal, being lowest in non-pregnant animals, increasing to a peak during mid-pregnancy and declining towards term.
Addressing Sexual Problems in HIV Primary Care: Experiences from Patients

Evidence suggests that sexual problems are common among people living with HIV and may be related to sexual risk taking and treatment adherence. This study explored the extent to which sexual problems experienced by people with HIV are addressed in primary care as well as how primary care responses to sexual problems are experienced by patients. Structured interviews were conducted with 60 patients at an urban HIV clinic. The average age of the participants (37 male, 23 female) was 45.8 years (SD = 7.9). Sexual problems were common. The most common sexual problem experienced in the past year was a lack of interest in sex (53.3 % reported) and the least common problem was painful intercourse (reported by 20 %). There were no gender differences in reports of sexual problems, except that painful intercourse was more frequently reported by women than men. Relatively few individuals who experienced sexual problems had discussed them with their provider, but these individuals were generally pleased with the counseling they had received and could identify several factors that facilitated a positive patient-provider interaction. Those who offer primary care services to people with HIV should be aware of sexual problems their patients may be experiencing and should feel confident in their ability to successfully address these problems. Providers may need additional training in order to adequately address sexual problems among people with HIV in primary care settings.
Optimization of probe geometry for diffuse optical brain imaging based on measurement density and distribution

Optode geometry plays an important role in achieving both good spatial resolution and spatial uniformity of detection in diffuse-optical-imaging-based brain activation studies. The quality of reconstructed images for six optode geometries were studied and compared using a laboratory tissue phantom model that contained an embedded object at two separate locations. The number of overlapping measurements per pixel (i.e., the measurement density) and their spatial distributions were quantified for all six geometries and were correlated with the quality of the resulting reconstructed images. The latter were expressed by the area ratio (AR) and contrast-to-noise ratio (CNR) between reconstructed and actual objects. Our results revealed clearly that AR and CNR depended on the measurement density asymptotically, having an optimal point for measurement density beyond which more overlapping measurements would not significantly improve the quality of reconstructed images. Optimization of probe geometry based on our method demonstrated that a practical compromise can be attained between DOI spatial resolution and measurement density.
Congenital syphilis: Observations on laboratory diagnosis of intrauterine infection

Summary A fatal case of congenital syphilis is presented with extremely severe, but very sharply localized skin manifestations. The infant's VDRL titer was 2 tube dilutions higher than the mother's, even though the infant's serum showed an apparent absence of IgM. It appears that a detectable IgM elevation in the newborn infant is not a constant finding in all types of intrauterine infection.
On the ‘one and one‐half dimensional’ relativistic Vlasov–Maxwell system

The time evolution of a collisionless plasma is studied in the case when the Viasov density ƒ is a function of the time, one space variable and two velocity variables. The electromagnetic fields E, B also have a special structure, and the magnetic field B is non-trivial. It is shown that smooth, consistent initial values generate a uniquc smooth global solution.
A detailed characterization of the effects of four cannabinoid agonists on operant lever pressing

p time interval between the offset of one lever press and the onset of the next) and the response duration (the amount of time that elapses from the onset to the offset of one lever press) of each lever press. ITs were further partitioned into fast responses (IT=0.0‐1.0 s), short pauses (IT=1.0‐2.5 s), and long pauses (IT>2.5 s). Four cannabimimetic agents were assessed in this study: ( R)-methanandamide (AM 356), a hydrolytically stable analog of arachidonylethanolamide, an endogenous ligand for the CB1 receptor; CP-55,940, a potent non-classical synthetic ligand; (-)-Δ 8 -tetrahydrocannabinol (Δ 8 -THC), an isomer of the naturally occurring Δ9-THC; and WIN 55,212-2, a synthetic aminoalkylindole. All four of the cannabimimetic drugs tested significantly suppressed operant lever pressing in a dose dependent manner. The rank order of potencies observed in the present study was CP-55,940>>WIN-55,212-2>Δ8-THC>AM 356, which is consistent with the rank order of affinities for the CB1 receptor shown by these drugs. All of the cannabimimetics substantially increased average IT, and also increased duration time. There was a substantial increase in average length of long pauses, and statistically significant but very small changes in the local rate of responding as measured by the average length of fast ITs. Cannabinoidtreated rats were largely immobile during pauses in responding, and these animals showed several signs of ataxia and catalepsy at the doses that suppressed lever pressing. Together with other data, the present results suggest that CB1 stimulation leads to motor effects that are associated with a suppression of lever pressing. &kwd:words Tetrahydrocannabinol · THC · Anandamide · Catalepsy · Motor · Response initiation&bdy:
Genetic Analysis of the Methanol- and Methylamine-Specific Methyltransferase 2 Genes of Methanosarcina acetivorans C2A

The entry of methanol into the methylotrophic pathway of methanogenesis is mediated by the concerted effort of two methyltransferases, namely, methyltransferase 1 (MT1) and methyltransferase 2 (MT2). The mtaA1, mtaA2, and mtbA genes of Methanosarcina acetivorans C2A encode putative methanol- or methylamine-specific MT2 enzymes. To address the in vivo roles of these genes in growth and methanogenesis from known substrates, we constructed and characterized mutants with deletions of each of these genes. The mtaA1 gene is required for growth on methanol, whereas mtaA2 was dispensable. However, the mtaA2 mutant had a reduced rate of methane production from methanol. Surprisingly, deletion of mtaA1 in combination with deletions of the genes encoding three methanol-specific MT1 isozymes led to lack of growth on acetate, suggesting that MT1 and MT2 enzymes might play an important role during growth on this substrate. The mtbA gene was required for dimethylamine and monomethylamine (MMA) utilization and was important, but not required, for trimethylamine utilization. Analysis of reporter gene fusions revealed that both mtaA1 and mtbA were expressed on all methanogenic substrates tested. However, mtaA1 expression was induced on methanol, while mtbA expression was down-regulated on MMA and acetate. mtaA2 was expressed at very low levels on all substrates. The mtaA1 transcript had a large 5′ untranslated region (UTR) (275 bp), while the 5′ UTR of the mtbA transcript was only 28 bp long.
Adult Education in the Urban Context.

Context is vitally important for urban adult education because it tends to create physical, psychological, and sociocultural distance between and among learners and various providers of adult and continuing education programs, thereby creating barriers and the differential provision of adult learning opportunities for some urban populations.
Power leader fault detection in nonlinear leader-follower networks

This paper presents a model for fault detection of a power leader in nonlinear leader-follower networks. The fault detection method is developed for the network model proposed by Wang and Slotine. Every follower is coupled with a nonlinear, neural net based observer for fault detection. Neural net tuning algorithms are derived and fault identifiers are developed using the Lyapunov approach. We consider fault detection of the power leader, and how such fault propagates through the network. We estimate the power leader fault detectability time based on the followers? observers. The paper studies properties of the fault dynamics i.e., the dynamics of a fault evolution process through a network of interconnected dynamic elements. The approach for leader-follower fault detection can also be used with any other type of nonlinear systems observer. Simulation results are presented to illustrate the effectiveness of the proposed technique.
Postpartum depression and apical ballooning syndrome (takotsubo syndrome).

Abstract Background Acute cardiac complications occur occasionally during pregnancy and in the immediate postpartum period. Some of these cardiac scenarios are rare and provide a diagnostic challenge. We report a case of apical ballooning syndrome (ABS), also known as takotsubo cardiomyopathy or broken-heart syndrome, in a postpartum patient. Case A 32-year-old multigravid woman presented at 17 days after delivery with chest pain typical for cardiac ischemic pain. Her prior obstetrical history included two uncomplicated vaginal deliveries, and the current postpartum period had been uncomplicated until the time of presentation. Cardiac catheterization was performed and showed normal coronary blood vessels with no evidence of coronary artery occlusion. Left ventricular systolic function was moderately depressed, with an ejection fraction of 45%. The patient had full recovery of myocardial function in less than 40 days, with a subsequent echocardiogram during that time showing a normal ejection fraction of 65%. Conclusion Apical ballooning syndrome is a rare reversible cardiac condition that should be differentiated from ischemic and peripartum cardiomyopathy, especially in the immediate postpartum period.
Structure and Development of the Continental Margin of British Honduras

The continental margin of British Honduras is characterized by elongate ridges that are sub-parallel with the coast and that diverge slightly northward. Each ridge apparently is formed by aligned fault blocks composed of continental basement rock that rotated and subsided during rifting of the margin. The western part of the Cayman Ridge may be underlain by similar rock that extends southwestward into the margin. Little sediment has been trapped in the basins between the ridges, presumably as a result of long-term, low rates of sedimentation. A canyon system that is controlled by both fault-block ridges and cross faults transects the margin and opens into the Yucatan Basin. Deep-sea sediments are characterized by a succession of pelagic deposits above acoustic basement rocks; these deposits are covered by turbidites that have formed deep-sea fan deposits in some places. The change from pelagic to turbidite deposition may have occurred at the end of Cretaceous time when regional uplift provided a source for clastic materials. The principal channel for transport of sediment to the deep sea is believed to be a graben that extends northeastward from the southwest corner of the Gulf of Honduras. Development of the margin may have begun in Late Jurassic time when sphenochasmic rifting created the ancestral Gulf of Honduras. Near the end of Cretaceous time, a new set of motions began, with the Caribbean plate moving relatively eastward and slightly away from the North American plate. This new motion resulted in continued movement of basement blocks through Tertiary and Quaternary time. Although this margin is not young, it has a geomorphically youthful aspect in that the sedimentary sequences do not obscure the rift structures.
Sensitive Assay for Mitochondrial DNA Polymerase γ

Background: The mitochondrial DNA polymerase γ is the principal polymerase required for mitochondrial DNA replication. Primary or secondary deficiencies in the activity of DNA polymerase γ may lead to mitochondrial DNA depletion. We describe a sensitive and robust clinical assay for this enzyme. Methods: The assay was performed on mitochondria isolated from skeletal muscle biopsies. High-molecular weight polynucleotide reaction products were captured on ion-exchange paper, examined qualitatively by autoradiography, and quantified by scintillation counting. Results: Kinetic analysis of DNA polymerase γ by this method showed a K m for dTTP of 1.43 μmol/L and a K i for azidothymidine triphosphate of 0.861 μmol/L. The assay was linear from 0.1 to 2 μg of mitochondrial protein. The detection limit was 30 units (30 fmol dTMP incorporated in 30 min). The linear dynamic range was three orders of magnitude; 30–30 000 units. Imprecision (CV) was 6.4% within day and 12% between days. Application of this assay to a mixed population of 38 patients referred for evaluation of mitochondrial disease revealed a distribution with a range of 0–2506 U/μg, reflecting extensive biologic variation among patients with neuromuscular disease. Conclusion: This assay provides a useful adjunct to current laboratory methods for the evaluation of patients with suspected mitochondrial DNA depletion syndromes.
A Double‐Observer Method to Estimate Detection Rate During Aerial Waterfowl Surveys

We evaluated double-observer methods for aerial surveys as a means to adjust counts of waterfowl for incomplete detection. We conducted our study in eastern Canada and the northeast United States utilizing 3 aerial-survey crews flying 3 different types of fixed-wing aircraft. We reconciled counts of front- and rear-seat observers immediately following an observation by the rear-seat observer (i.e., on-the-fly reconciliation). We evaluated 6 a priori models containing a combination of several factors thought to influence detection probability including observer, seat position, aircraft type, and group size. We analyzed data for American black ducks (Anas rubripes) and mallards (A. platyrhynchos), which are among the most abundant duck species in this region. The best-supported model for both black ducks and mallards included observer effects. Sample sizes of black ducks were sufficient to estimate observer-specific detection rates for each crew. Estimated detection rates for black ducks were 0.62 (SE = 0.10), 0.63 (SE = 0.06), and 0.74 (SE = 0.07) for pilot-observers, 0.61 (SE = 0.08), 0.62 (SE = 0.06), and 0.81 (SE = 0.07) for other front-seat observers, and 0.43 (SE = 0.05), 0.58 (SE = 0.06), and 0.73 (SE = 0.04) for rear-seat observers. For mallards, sample sizes were adequate to generate stable maximum-likelihood estimates of observer-specific detection rates for only one aerial crew. Estimated observer-specific detection rates for that crew were 0.84 (SE = 0.04) for the pilot-observer, 0.74 (SE = 0.05) for the other front-seat observer, and 0.47 (SE = 0.03) for the rear-seat observer. Estimated observer detection rates were confounded by the position of the seat occupied by an observer, because observers did not switch seats, and by land-cover because vegetation and landform varied among crew areas. Double-observer methods with on-the-fly reconciliation, although not without challenges, offer one viable option to account for detection bias in aerial waterfowl surveys where birds are distributed at low density in remote areas that are inaccessible by ground crews. Double-observer methods, however, estimate only detection rate of animals that are potentially observable given the survey method applied. Auxiliary data and methods must be considered to estimate overall detection rate.
Conversion of control dependence to data dependence

Program analysis methods, especially those which support automatic vectorization, are based on the concept of interstatement dependence where a dependence holds between two statements when one of the statements computes values needed by the other. Powerful program transformation systems that convert sequential programs to a form more suitable for vector or parallel machines have been developed using this concept [AllK 82, KKLW 80].The dependence analysis in these systems is based on data dependence. In the presence of complex control flow, data dependence is not sufficient to transform programs because of the introduction of control dependences. A control dependence exists between two statements when the execution of one statement can prevent the execution of the other. Control dependences do not fit conveniently into dependence-based program translators.One solution is to convert all control dependences to data dependences by eliminating goto statements and introducing logical variables to control the execution of statements in the program. In this scheme, action statements are converted to IF statements. The variables in the conditional expression of an IF statement can be viewed as inputs to the statement being controlled. The result is that control dependences between statements become explicit data dependences expressed through the definitions and uses of the controlling logical variables.This paper presents a method for systematically converting control dependences to data dependences in this fashion. The algorithms presented here have been implemented in PFC, an experimental vectorizer written at Rice University.
Vein wall re-endothelialization after deep vein thrombosis is improved with low-molecular-weight heparin

Objective Vein wall endothelial turnover after stasis deep vein thrombosis (DVT) has not been well characterized. The purpose of this study was to quantify re-endothelialization after DVT and determine if low-molecular-weight heparin (LMWH) therapy affects this process. Methods Stasis DVT was generated in the rat by inferior vena cava ligation, with harvest at 1, 4, and 14 days. Immunohistologic quantification of vascular smooth muscle cells and luminal endothelialization was estimated by positive staining for α-smooth muscle actin and von Willebrand factor, respectively. In separate experiments, rats were treated either before or after DVT with subcutaneous LMWH (3 mg/kg daily) until harvesting at 4 and 14 days. The inferior vena cava was processed for histologic analysis or was processed for organ culture after the thrombus was gently removed. The vein wall was stimulated in vitro with interleukin-1β (1 ng/mL), and the supernatant was processed at 48 hours for nitric oxide. Cells were processed by real-time polymerase chain reaction for endothelial nitric oxide synthase, inducible nitric oxide synthase, cyclooxygenase-1 and -2, and thrombomodulin at 4 and 14 days, and collagen I and III at 14 days. Comparisons were done with analysis of variance or t test. A P Results Thrombus size peaked at 4 days, whereas luminal re-endothelialization increased over time (1 day, 11% ± 2%; 4 days, 23% ± 4%; 14 days, 64% ± 7% (+) von Willebrand factor staining; P Conclusions Venous re-endothelialization occurs progressively as the DVT resolves and can be accelerated with LMWH treatment, although this effect appears limited to the early time frame. These findings may have clinical relevance for LMWH timing and treatment compared with mechanical forms of therapy.
Serum cleaved tau does not predict postconcussion syndrome after mild traumatic brain injury

Abstract Objectives Our objective was to determine if the biomarker for axonal injury, serum cleaved tau (C-tau), predicts postconcussion syndrome (PCS) in adults after mild traumatic brain injury (mTBI). Methods C-tau was measured from blood obtained in the emergency department. Outcome was assessed at 3 months post injury using the Rivermead Postconcussion Symptoms Questionnaire and Acute Medical Outcomes SF-36v2 Health Survey (SF-36). Results Of 50 patients, there were 15 patients with detectable levels of C-tau, 10 patients with abnormal findings on initial head computed tomography (CT) and 22 patients with PCS. One-third of patients with detectable C-tau and 14.3% of patients without detectable C-tau had abnormal findings on head CT (P = .143). Serum C-tau was not detected more frequently in patients with PCS than those without, neither for all patients (P = .115) nor the subgroup with negative head CT (P = .253). Conclusions C-tau is a poor predictor of PCS after mTBI regardless of head CT result.
Multiple transcriptional regulatory domains in the human immunodeficiency virus type 1 long terminal repeat are involved in basal and E1A/E1B-induced promoter activity.

Abstract The human immunodeficiency virus (HIV) type 1 long terminal repeat (LTR) is the site of activation of the HIV tat protein. However, additional transactivators, such as the adenovirus E1A and herpesvirus ICPO proteins, have also been shown to be capable of activating the HIV LTR. Analysis of adenovirus mutants indicated that complete transactivation of the HIV LTR was dependent on both the E1A and E1B proteins. To determine which regions of the HIV LTR were important for complete E1A/E1B activation, a variety of oligonucleotide-directed mutations in HIV transcriptional regulatory domains were assayed both in vivo and in vitro. S1 nuclease analysis of RNA prepared after transfection of these HIV constructs into HeLa cells infected with wild-type adenovirus indicated that the enhancer, SP1, TATA, and a portion of the transactivation-responsive element were each required for complete E1A/E1B-mediated activation of the HIV LTR. These same promoter elements were required for both basal and E1A/E1B-induced levels of transcription in in vitro transcription reactions performed with cellular extracts prepared from cells infected with dl434, an E1A/E1B deletion mutant, or wild-type adenovirus. No mutations were found that reduced only E1A/E1B-induced expression without proportionally reducing basal levels of transcription, suggesting that E1A/E1B-mediated induction of the HIV LTR requires multiple promoter elements which are also required for basal transcriptional levels. Unlike activation by the tat protein, there was not a rigid dependence on maintenance of the transactivation-responsive stem base pairing for E1A/E1B-mediated activation either in vivo or in vitro, indicating that activation occurs by a mechanism distinct from that of tat induction.
Valvular heart disease and pregnancy. Part I: Native valves

Pregnancy in patients with valvular heart disease (VHD) continues to pose a challenge to both physicians and their patients and could be associated with an unfavorable maternal as well as fetal outcome. The purpose of this paper is to review the available clinical data and provide recommendations for the management of patients with VHD during gestation.
Nutrient subsidies from nekton in salt marsh intertidal creeks

Motile organisms are thought to play a role in biogeochemical cycles in tidal systems, but few studies have addressed links between animal activities and dissolved nutrients. Our observations and experiments indicated that movements, feeding, and excretion by fishes and shrimps resulted in subsidies of NH z and PO 3{ 4 to intertidal salt marsh creeks. During low tide, isolated pools inhabited by nekton became biogeochemical hotspots with up to fivefold increases in water column nutrient concentrations. In field experiments, simultaneous measurements in artificial pools and an adjacent natural intertidal pool demonstrated that nekton were sources of NH z during day and night, contributing 17–109% of the net increase in NH z and 3–18% of the PO 3{ 4 in the natural intertidal pool. Nekton residing in intertidal pools generated the equivalent of 5% of the total NH z imported to the creek. At night, nekton in pools contributed the equivalent of 12% of the NH z and 4% of the PO 3{ 4 imported from the subtidal channel. As the tide flooded the intertidal creek, nutrient enriched pool water was pulsed up the creek and into the intertidal basin. Tidally controlled patterns of nekton movements and feeding result in retention and reintroduction of nutrients to the upper reaches of intertidal creek basins. Accordingly, nekton contribute to the recycling of nutrients through a positive feedback loop that may enhance primary production and invertebrate prey within salt marsh creek basins. We conclude that nekton can be important and underappreciated contributors of dissolved nutrients in tidal systems.