cssi/SciSciGPT-SciSciNet huggingface dataset:
Ten-year experience with aortic valve replacement in 482 patients 70 years of age or older: Operative risk and long-term results☆

Abstract A retrospective analysis of an institutional experience with aortic valve replacement (AVR) in patients 70 years of age or older during 1976 to 1987 was performed. The study was prompted in part by the current interest in palliative aortic valvoplasty, an interest based to a certain extent on the impression that AVR in the elderly has a high mortality. The mean age of the patients was 75.0 ± 4.0 years (± the standard deviation) (range, 70 to 89 years). Eighty-three percent of patients received porcine valves and 17%, mechanical valves. Preoperatively 32% were in New York Heart Association class III, and 59% were in class IV. Operative mortality was 5.6% for elective isolated AVR for aortic stenosis (19% of all patients), 8.2% for all isolated AVR (38%), and 12.4% overall. Concomitant operative procedures were done in 62.0%; AVR with coronary artery bypass grafting (42%) had an operative mortality of 14.3%. Multivariate analysis showed significant predictors of operative mortality to be emergency operation ( p p = 0.01), and previous cardiac operation ( p = 0.02). Follow-up (34 ± 27 months) was 94% complete. Five-year survival from late cardiac-related death was 81.0%. The constant yearly hazard rate for late death for patients 70 year of age or older who underwent AVR was 5.42% per year, which is similar to the 5.77% per year rate calculated for age-matched and sex-matched controls. Five-year freedom from reoperation was 99%; from late thromboembolic complications, 91%; and from late anticoagulant-related complications, 94%. Freedom from all valve-related morbidity and mortality was 61% at 5 years. At follow-up, 80% of patients reported symptomatic improvement, and 76% were in New York Heart Association class I or II. These results show that AVR in the elderly is safe and effective, with late survival rates similar to those of the general population. Thus AVR remains the procedure of choice in patients 70 years of age or older with substantial aortic valve disease.
Effects of glucose and glutamine concentration in the formulation of the artificial cerebrospinal fluid (ACSF)

Abstract The composition of the ACSF is fundamental in controlling the extracellular environment of the brain slice preparation. ‘Typical’ formulations lack amino acids and contain a higher concentration of glucose (10 mM) than in the cerebrospinal fluid (0.47 – 4.4 mM). We examined the effects of different concentrations of glutamine, the most abundant amino acid in the CSF, and glucose on rat hippocampal slice physiology. Bipolar paired-pulse stimulation was applied to the Schaffer collaterals and population spikes were monitored in the CA1 pyramidal layer for ~1 hour. Addition of glutamine (0.5 mM) to slices superfused with 10 mM of glucose did not enhance population spike amplitude. Higher concentration of glutamine (2-5 mM) resulted in spreading-depression. Decreasing glucose concentration from 10 mM to 5 mM, in the absence of glutamine, attenuated population spikes. Decreasing glucose to 2 mM, in the absence of glutamine, suppressed evoked population spikes. Superfusing brain slices with ACSF containing ‘physiological’ concentrations of both glucose (2 mM) and glutamine (0.5 mM) similarly suppressed population spikes. In separate experiments, during high-K+ induced epileptiform activity, glutamine (0.5 mM) did not affect the burst duration, frequency or waveform. These results suggest that the concentration of glucose in ACSF should conservatively be 10 mM in order to maximize paired-pulse population responses while the presence of physiological concentration of glutamine (0.5 mM) has minimal effects on paired-pulse responses and high-K+ induced epileptiform activity. These results are discussed in the context of fundamental differences between in vitro brain slice superfusion and in vivo brain perfusion.
Empathy from a nursing perspective: Moving beyond borrowed theory

Empathy is a concept deeply rooted in and central to professional nursing. Although viewed as an important concept, little consensus exists in the professional literature about either the definition or the application of the concept to nursing practice. This article will compare two theories of empathy, one borrowed from Kohut's self-psychology model and one derived from King's Interacting Systems nursing framework. The two theories are examined to clarify issues pertaining to the concept of empathy and to identify the contributions and limitations of borrowed theory as the basis for nursing practice. The article explores similarities and difference in the two views of empathy and highlights the necessity of developing nursing science from theory based in nursing which reflects the very unique nature of nursing practice. Nursing as a profession is distinct and unique, and borrowed theory must be questioned for its fit and applicability to the profession. The article concludes that empathy is a nursing phenomenon needing to be studied from a nursing perspective. The results of continued use of borrowed theory pertaining to empathy is discussed including the delay and misdirection of ongoing activity to develop the concept of empathy.
Dactylis glomerata Growing Along a Light Gradient in the Central Appalachian Region of the Eastern USA: III. Nonstructural Carbohydrates and Nutritive Value

Microsite conditions influence plant development and resource allocation of Dactylis glomerata L. (orchardgrass), a traditional pasture species with potential as an understory crop in woodlots. A field experiment was conducted to determine how open (O), shaded woodland (W) and open-to-shaded woodland transition zone (EO, EW) microsites influenced the quantity and distribution of nonstructural carbohydrate (TNC) and crude protein (CP) among plant parts of defoliated orchardgrass. Plants established in spring (SP) or late summer (LS) were clipped each time mean sward height reached 20 cm. Microsite conditions influenced nutritive value of herbage. Nutritive value was acceptable when not more than 45–50% light attenuation (as a function of shading by nearby trees) occurred relative to open pasture. Twice as much TNC accumulated in stembases of LS compared to SP plants. Concentrations of TNC were least in plants growing at W, regardless of planting time. Stembase TNC depletion occurred in SP plants, regardless of microsite, and LS plants growing at W. CP concentrations were greater in herbage from W compared to O sites, suggesting the N needs of the plant were met with minimal fertilizer N inputs. The ratio of C:N and thus herbage energy expressed as total digestible nutrients (TDN), relative to CP declined as shade increased. Increased protein content is offset by lower fiber, lower nonstructural carbohydrate and the possibility of reduced preference by grazers. Nutritive value is improved by modest amounts of shade relative to plants growing in full sunlight, and allowing cool temperate origin grasses to vernalize is beneficial in terms of productivity, nutritive value, and persistence.
Context-aware recommendation algorithms for the percepolis personalized education platform

This paper describes Pervasive Cyberinfrastructure for Personalized Learning and Instructional Support (PERCEPOLIS), where context-aware recommendation algorithms facilitate personalized learning and instruction. Fundamental to PERCEPOLIS are (a) modular course development and offering, which increase the resolution of the curriculum and allow for finer-grained personalization of learning artifacts and associated data collection; (b) blended learning, which allows class time to be used for active learning, interactive problem solving and reflective instructional tasks; and (c) networked curricula, in which the components form a cohesive and strongly interconnected whole where learning in one area reinforces and supports learning in other areas. Intelligent software agents customize the content of a course for each learner, based on his or her academic profile and interests, aided by context-based recommendation algorithms. This paper provides an introduction to the PERCEPOLIS platform, with focus on these algorithms; and describes the educational research that underpins its design.
Bartering Globalization: China's Commodity‐backed Finance in Africa and Latin America

In just over a decade, China has become a source of finance for emerging market and developing country governments. Recipient governments and the Chinese have been less than transparent with respect to the scale, terms and composition of this finance, engendering a great deal of speculation about its nature. This article provides preliminary estimates of Chinese finance to both Africa and Latin America since the turn of the century, with a specific focus on ‘commodity-backed’ or ‘resource-secured’ loans. We estimate that Chinese banks have provided approximately $132 billion in financing to African and Latin American governments and state-owned firms since 2003. Just over half of these, or $75 billion, are in the form of resource-secured finance. Contrary to many of the claims in the popular press, we found that Chinese finance is generally not out of line with interest rates found in global capital markets, does not bring windfall commodity profits to China, and does not mandate the use of Chinese workers.
Developmental distribution of reelin-positive cells and their secreted product in the rodent spinal cord.

To date, only sympathetic and parasympathetic preganglionic neurons are known to migrate abnormally in reeler mutant spinal cord. Reelin, the large extracellular matrix protein absent in reeler, is found in wild-type neurons bordering both groups of preganglionic neurons. To understand better Reelin’s function in the spinal cord, we studied its developmental expression in both mice and rats. A remarkable conservation was found in the spatiotemporal pattern of Reelin in both species. Numerous Reelin-expressing cells were found in the intermediate zone, except for regions containing somatic and autonomic motor neurons. A band of Reelin-positive cells filled the superficial dorsal horn, whereas only a few immunoreactive cells populated the deep dorsal horn and dorsal commissure. High levels of diffuse Reelin product were detected in the lateral marginal and ventral ventricular zones in both rodent species. This expression pattern was detected at all segmental spinal cord levels during embryonic development and remained detectable at lower levels throughout the first postnatal month. To discriminate between the cellular and secreted forms of Reelin, brefeldin A was used to block secretion in organotypic cultures. Such perturbations revealed that the high levels of secreted Reelin in the lateral marginal zone were derived from varicose axons of more medially located Reelin-positive cells. Thus, the laterally located secreted Reelin product may normally prevent the preganglionic neurons from migrating too far medially. Based on the strong evolutionary conservation of Reelin expression and its postnatal detection, Reelin may have other important functions in addition to its role in neuronal migration. J. Comp. Neurol. 468:165–178, 2004. © 2003 Wiley-Liss, Inc.
Business Technology Strategy for an Energy Management Company

This paper focuses on the development of a business technology strategy for an energy management company. EnDis1 manages the distribution of electric power to a specific geographic region, and is a regional transmission organization RTO.2 The primary mission of EnDis is reliability and security. The case describes the process of developing a technology strategy for the company recognizing the unique mission the company has in maintaining electric power for their customers.
Fibrocartilaginous embolism of the spinal cord in dogs: review of 36 histologically confirmed cases and retrospective study of 26 suspected cases.

Clinical features of 36 dogs with histologically confirmed fibrocartilaginous embolism (FCE) were contrasted with those of 26 dogs in which FCE was suspected based on characteristic clinical findings and the absence of compressive spinal cord disease on myelography. Dogs with confirmed and suspected FCE were of similar signalment, and had acute, nonprogressive dysfunction, often associated with trauma or exercise. The “suspected” group included fewer giant breeds and more often had asymmetric lesions, intact nociception, and upper motor neuron involvement. Dog size and severity of clinical signs probably contributed to owners choosing euthanasia in dogs with confirmed lesions. Accordingly, data from such patients may be skewed relative to these clinical features. J Vet Intern Med 1996;10:241–245. Copyright©1996 by the American College of Veterinary Internal Medicine.
A test for ectopic exchange catalyzed by Cre recombinase in maize

A maize line expressing Cre recombinase as well as the recipient line without the transgene were assayed for evidence of ectopic recombination within the maize genome. Such a test is valuable for understanding the action of Cre as well as for its use to recombine two target lox sites present in the chromosomes. Pollen examination and seed set tests of material expressing Cre provided no evidence of ectopic recombination, which would be manifested in the production of translocations or inversions and result in pollen abortion and reduced seed set. Root-tip chromosome karyotype analysis was also performed on material with and without Cre expression. Chromosomal aberrations in Cre+ material were not observed above the background level.
Exploiting Channel Fragmentation and Aggregation/Bonding to Create Security Vulnerabilities

We address a unique security vulnerability due to spectrum fragmentation, aggregation, and bonding in IEEE 802.22-based dynamic spectrum access (DSA) networks and in Long-Term Evolution (LTE) and Evolved High-Speed Packet Access (HSPA+) networks. Typically, channel fragmentation, aggregation, and bonding have been perceived as a means of enhancing the bandwidth and throughput for the users. However, this could also result in losing orthogonality between the bonded or fragmented spectrum bands. We show this leads to a security vulnerability that can be exploited by an attacker to cause service disruptions. We present an analysis of two types of attacks, i.e., the MAXimum IMPact (MAXIMP) attack, wherein the attackers try to cause maximum service disruptions by transmitting at maximum power, and the MINPOW attack, wherein the attackers transmit at minimum power just to create a targeted level of service disruption. Results indicate that, although the MAXIMP attack can cause up to about 16% loss in the capacity of the system, the MINimum POWer (MINPOW) attack, which is more difficult to detect than the MAXIMP attack, can cause 11%-15% loss in throughput.
Nitration of tyrosine by hydrogen peroxide and nitrite

Peroxynitrite anion is a powerful oxidant which can initiate nitration and hydroxylation of aromatic rings. Peroxynitrite can be formed in several ways, e.g. from the reaction of nitric oxide with superoxide or from hydrogen peroxide and nitrite at acidic pH. We investigated pH dependent nitration and hydroxylation resulting from the reaction of hydrogen peroxide and nitrite to determine if this reaction proceeds at pH values which are known to occur in vivo. Nitration and hydroxylation products of tyrosine and salicyclic acid were separated with an HPLC column and measured using ultraviolet and electrochemical detectors. These studies revealed that this reaction favored hydroxylation between pH 2 and pH 4, while nitration was predominant between pH 5 and pH 6. Peroxynitrite is presumed to be an intermediate in this reaction as the hydroxylation and nitration profiles of authentic peroxynitrite showed similar pH dependence. These findings indicate that hydrogen peroxide and nitrite interact at hydrogen ion concentrations present under some physiologic conditions. This interaction can initiate nitration and hydroxylation of aromatic molecules such as tyrosine residues and may thereby contribute to the biochemical and toxic effects of the molecules.
Wallace Stegner's Arabian Discovery: Imperial Blind Spots in a Continental Vision

In 1956 Wallace Stegner wrote a history of the Arabian American Oil Company (Aramco), but it was only published fifteen years later——in Beirut. The book complicates the view of Stegner as a destroyer of American western myths and a forerunner of the social and environmental turn in western history. Stegner shared with those who bought his services some problematic ideas about American identity and history in the context of the Cold War. His forgotten history of oil exploration in Saudi Arabia reveals the blind spots in his ““continental vision,”” an inability or unwillingness to see the moment as part of the long, unbroken past of the U.S. West. Stegner9s journey, from chronicler of the despoiling of the West by eastern oil and copper barons to defender of cultural diversity and the collective commons, stopped, as it has for many other Americanists, at the water9s edge.
Incidence of fecal contamination within a public drinking water supply in Ratta Amral, Rawalpindi

The aim of this study was to monitor microbial water quality and residual chlorine in drinking water supplies at the treatment plant and in the water distribution network of Ratta Amral, Rawalpindi, Pakistan. The drinking water quality in the distribution network was performed by collecting samples from water source, over head reservoir and residential taps and for analyzing chemical and microbial parameters. The samples were analyzed for physico-chemical indicators (total chlorine, free chlorine residual, turbidity, total dissolved solids and conductivity) and bacterial indicators (total and fecal coliforms). The average value of total chlorine at filtration plant was found to be ranging between 0.0 to1.3 mg/l. Chlorine residue via distribution network available at consumer end was below detectable level at all sampling sites. The study is in progress to monitor the drinking water quality in the twin cities of Rawalpindi and Islamabad.
A novel human fibroblast growth factor treats experimental intestinal inflammation

Abstract Background & Aims: We recently identified a novel member of the human fibroblast growth factor (FGF) family of signaling molecules, designated FGF-20. In the present study, we examined the activity of this protein in 2 animal models of acute intestinal inflammation and in mechanistic studies in vitro. Methods: In vivo experiments consisted of a murine dextran sulfate sodium (DSS) model of colitis and a rat indomethacin model of small intestinal ulceration/inflammation. Cell growth, restitution, gene expression (cyclooxygenase-2 [COX-2] and intestinal trefoil factor [ITF]), and prostaglandin E 2 (PGE 2 ) levels were examined in vitro. Results: In the DSS-colitis model, prophylactic administration of FGF-20 significantly reduced the severity and extent of mucosal damage as indicated by a 55%–93% reduction in luminal blood loss, distal colonic edema, histologic inflammation, and epithelial cell loss relative to animals administered vehicle control. No toxicity was noted during administration of FGF-20 to normal controls. In addition, therapeutic administration of FGF-20 enhanced survival in this model. In the indomethacin–small bowel ulceration/inflammation model, administration of FGF-20 reduced small intestinal weight gain, necrosis, inflammation, and weight loss (36%–53% relative to vehicle control). In vitro studies demonstrated that FGF-20 stimulates growth, restitution, mRNA expression of COX-2 and ITF, and PGE 2 levels in human intestinal epithelial cells and enhances the growth of human intestinal fibroblasts. Conclusions: FGF-20, having demonstrated therapeutic activity in 2 experimental models of intestinal inflammation, represents a promising new candidate for the treatment of human inflammatory bowel disease. GASTROENTEROLOGY 2002;123:1151-1162
Isolated lung transplantation in children: Pathological diagnosis and incidence of pulmonary complications

The pathological findings in the allografts of 14 children who underwent lung transplantation (LT) at St. Louis Children's Hospital, St. Louis, MO, in the period between July 1990 and May 1992 were reviewed. The study is based on histological analysis of 63 transbronchial biopsy (TBB) specimens, eight open lung biopsy specimens, and three pneumonectomy specimens. The mean age at transplantation was 10.5 years (range, 1 to 17 years) and the average follow-up period was 5.7 months. Sufficient tissue for an adequate pathological examination was obtained in 58 (92%) TBB specimens. Each specimen consisted of a mean of 6.12 tissue fragments, but only 4.79 fragments contained actual lung parenchyma for suitable examination. Ten patients (71%) had 23 biopsy-proven episodes of acute rejection with a frequency of 1.64 episodes per patient. The first episode was documented at a mean of 19 days after transplantation. Six patients (42.8%) developed bronchiolitis obliterans (BO). The definitive diagnosis of this condition was made either by open lung biopsy (n = 3) or on allograft pneumonectomy (n = 1), and it was infrequently recognized by TBB. Four of the six patients died less than 9 months after the diagnosis of BO was made, indicating the grave consequences of this complication. Two other deaths were attributed to the development of posttransplantation lymphoproliferative disorders.
Acrylamide and carbon disulfide treatments increase the rate of rat brain tubulin polymerization

Acrylamide and carbon disulfide produce central-peripheral distal axonopathy in experimental animals and humans. The main feature of this disease is the focal swellings containing neurofilaments in distal axons, followed by nerve degeneration beyond these swellings. We studied the possible role of tubulin assembly kinetics in this disease. The rats were either administered acrylamide (50 mg/kg, ip, saline) or exposed to carbon disulfide (700 ppm, 9 h) via inhalation for 12 and 15 d, respectively. Tubulin, purified from both acrylamide-(10.37 +/- 0.3 vs 11.3 +/- 0.15) and carbon disulfide-treated (9.72 +/- 0.5 vs 11.18 +/- 0.25) rat brains showed increase in Vmax (OD/min x 10(3)) of its polymerization. However, only acrylamide treatment showed a decrease in time to Vmax, when brain supernatant was used for tubulin polymerization. In vitro addition of acrylamide (0.1-1 mM) to bovine brain tubulin also showed a decrease in time to Vmax (16-21%) of its polymerization. Carbon disulfide treatment of rats, on the other hand, showed a decrease in MAP-2 and an increase in a 120-kDa peptide concentration. The latter showed immunoreactivity with anti-MAP-2. The increase in the rate of tubulin polymerization by acrylamide and carbon disulfide treatment may alter the rate of transport of axonal constituents, including neurofilament, and contribute toward their accumulation in the focal swellings observed in this neuropathy.
Leachability of lead from solidified cement-fly ash binders

Potential of partly replacing cement with class C fly ash to immobilize lead was investigated. Lead nitrate up to a concentrations of 10% (by weight of binder) was solidified with binders such as Type I Portland cement and a cement-fly ash (equal proportion) mixture. Pore fluid analyses indicated that lead increased the calcium and silicon concentration in the pore fluid during the initial period of hydration of cement and cement-fly ash mixtures. Addition of fly ash to cement reduced the initial and final setting times, but with the addition of lead nitrate setting times were increased. The compressive strength of the solidified cement decreased with the addition of fly ash and lead nitrate. Lead leachability from the solidified binder matrix was studied using the Toxicity Characteristic Leaching Procedure (TCLP) recommended by the U. S. Environmental Protection Agency (EPA). The quantity of Pb(II) leached was dependent on the initial lead nitrate concentration and the binder systems adopted. Lead solidified with cement-fly ash mixture showed a slightly less leaching compared to the cement binder. A simple model has been proposed to predict the leachability of Pb(II) from the binder matrix.
The Relationship of Self-Reported Pain and Functional Impairment to Gait Mechanics in Overweight and Obese Persons with Knee Osteoarthritis

Abstract Nebel MB, Sims EL, Keefe FJ, Kraus VB, Guilak F, Caldwell DS, Pells JJ, Queen R, Schmitt D. The relationship of self-reported pain and functional impairment to gait mechanics in overweight and obese persons with knee osteoarthritis. Objective To examine the degree to which 2 commonly used measures of pain and disability, the Arthritis Impact Measurement Scales (AIMS) and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), relate to objective gait measurements. Design A descriptive study of the influence of self-reported pain and perceived functional impairment on gait mechanics in osteoarthritic adults. Setting A university clinical research laboratory. Participants Overweight/obese adults with radiographic knee osteoarthritis (OA) as well as pain and disability associated with the disease (N=179). Interventions Not applicable. Main Outcome Measures The AIMS and WOMAC were administered to determine self-report measures of pain and disability. Speed, stride length, support time, knee angle, and peak vertical force (PVF) were determined from 3-dimensional kinematic and kinetic data collected on subjects walking at self-selected normal and fast speeds. Anthropometric data and radiographic levels of OA were also collected. Results Pearson correlation analysis showed that the AIMS physical disability score was inversely correlated with speed, stride length, and knee range of motion at both speeds and PVF at the fast speed. The WOMAC function score was inversely correlated with speed and stride length at both speeds and with PVF at fast speed. The WOMAC pain score was inversely correlated with speed and PVF at the fast speed. Regression analysis revealed that the AIMS physical disability score and body mass index accounted for the greatest variation in speed at the normal speed. Overall, AIMS physical disability and WOMAC function explained a larger proportion of variance in gait mechanics than radiographic measures of OA disease severity. Conclusions Taken together, the results suggest that the AIMS physical disability and WOMAC function scores are associated with some important measures of gait impairment.
Barrett’s esophagus in the patients with familial adenomatous polyposis

Familial adenomatous polyposis (FAP) is caused by germ line mutations in the APC gene. Barrett's esophagus (BE) and Barrett's adenocarcinoma are intestinal type lesions of the esophagus characterized by an early loss of heterozygosity at the APC locus. We hypothesized that patients with FAP are at risk for the early development of BE due to the inherited mutations in the APC gene (haploinsufficiency). Upper gastrointestinal (UGI) tract biopsies from 36 patients with FAP were reviewed to determine the incidence and characteristics of BE in these patients. Twenty-four patients were confirmed carriers of a deleterious germline APC mutation. The other 12 patients were from FAP families with known APC gene mutations and had clinical manifestations of FAP. The control group consisted of patients who did not have a personal or family history of FAP undergoing UGI endoscopic examination in our institution over a 30 month period of time. The difference in expression of Wnt pathway proteins (APC, β-catenin, E-cadherin and cyclin D1) in BE between BE(+)/FAP(+), BE(-)/FAP(+) and age-matched BE(+)/FAP(-) groups was studied using immunohistochemistry. BE was found in 6 of 36 (6/36 or 16%) patients with FAP and in 266 of 1662 patients (16%) in the control group of symptomatic patients. The average age at the first diagnosis of BE in FAP patients was 37.8 versus 57.5 years in the control group (sporadic BE). When compared to age matched BE(+)/FAP- group (7/334), patients with FAP had a significantly (p = 0.005843, odds ratio 9.2; Fisher exact test) higher incidence of BE. Both classic FAP and attenuated FAP phenotypes were associated with BE .Two types of germ line mutations in APC gene were identified in BE(+)/FAP(+) patients: Five patients had 2-base deletion in exon 4 (426delAT) and one patient had 4-base deletion in exon 15 (3202del4). No difference in Wnt signaling pathway proteins expression was detected between BE(+)/FAP(+) and the age matched group of patients with sporadic BE (BE(+)/FAP(-)). Patients with FAP appear to have increased risk for the development of BE, which on average develops some 20 years earlier than in patients without FAP. This association needs to be taken in account when caring for the patients with FAP.
Synthesis of the C21–C34-segment of the aplyronines using the dimer of methylketene

Abstract This report describes a convergent synthesis of the C 21 –C 34 -segment of aplyronine. The starting point for both halves of this segment was the dimer of methylketene, readily available in either enantiomeric form by asymmetric catalysis. Diastereoselective reduction and functional group manipulation afforded the partners for a Wittig coupling reaction. The appropriate choice of oxygen protecting groups allowed the Wittig reaction to proceed, and hydrogenation of the resulting olefin afforded the C 21 –C 34 -synthon.
A lower bound to the complexity of Euclidean and rectilinear matching algorithms

Abstract The worst-case time complexity of any exact algorithm for the Euclidean or rectilinear minimum-weight perfect matching problem, which takes as input the list of coordinates of n points in R k, is shown to be bounded below by the infimum of the worst-case time complexities of all algorithms which sort n real numbers. This result also applies to any heuristic algorithm for which the worst-case ratio of the weight of the approximate matching it produces to the weight of the optimal matching only depends upon n.
Approximate closed-form solutions to finite-horizon optimal control of nonlinear systems

The Hamilton-Jacobi-Bellman partial differential equation, which is needed to be solved for finite-horizon optimal control of nonlinear systems, is reduced to a state-dependent differential Riccati equation subject to a final condition through some approximations. Afterward, a method, called Finite-SDRE, is developed for finite-horizon near-optimal control synthesis. This technique allows for easier online implementation and its global stability is proved. Finally an approximate solution to the differential equation is given. Performance of the proposed controller in representative numerical examples demonstrates its excellent potential for use in nonlinear finite-horizon problems.
Early removal of urinary catheter after radical retropubic prostatectomy is both feasible and desirable.

Abstract Objectives. To determine the feasibility and desirability of removing the urinary catheter 7 days after radical retropubic prostatectomy. Methods. Between February 28, 2000 and October 5, 2000, 184 men underwent radical retropubic prostatectomy by a single surgeon. Of these men, 97% underwent gravity cystography under fluoroscopic control on postoperative day (POD) 7. The indwelling urinary catheter was removed on POD 7 if no evidence of extravasation was observed on cystography. Patients completed a self-administered questionnaire at the time of catheter removal to capture the degree of bother from incisional pain and the indwelling urinary catheter during the recovery period. The level of urinary continence was determined at 3 months after radical retropubic prostatectomy. Results. One hundred thirty-five of the cystograms (75%) had no evidence of extravasation. The indwelling catheters were removed in 130 (97%) of 135 cases. The body weight, surgical specimen weight, presence or absence of intraoperative anastomotic extravasation, volume of pelvic drainage recorded from the Hemovac drain, and creatinine level of the pelvic drainage fluids did not predict the finding of extravasation on the POD 7 cystogram. Fifteen percent of the men whose catheters were removed on POD 7 developed acute urinary retention. At 3 months, 72% of men required no or a single protective pad, and 87% indicated they experienced no or slight bother from incontinence. These continence outcomes are comparable with a historical control group by the same surgeon who underwent catheter removal on POD 14. Forty-five percent of the men reported the catheter caused moderate to severe bother, compared with only 19% of men who indicated moderate to severe bother from incisional pain. In retrospect, 95.6% of men indicated willingness to undergo cystography on POD 7 with the intent of early catheter removal. Conclusions. The results of our study suggest that most men will have no extravasation on a cystogram performed on POD 7 and that removing the catheter at this time in these cases does not increase the risk of complications or compromise overall urinary continence. The urinary catheter is a significant bother and limits physical activity during the postoperative period. Cystography and early removal of the catheter is both feasible and desirable and should be offered to men after radical retropubic prostatectomy.
Safe adaptive switching control with no SCLI assumption

A new approach is proposed to dismiss the SCLI assumption in the safe adaptive control [1]. Fictitious signals and cost functions that are newly developed in this paper achieve the cost-detectability without imposing the SCLI assumption unlike [1] and [2] where the SCLI assumption is imposed on candidate controllers and on matrix fraction description forms of candidate controllers, respectively. Since this approach has virtually no assumption on candidate controllers, the safe adaptive control with this approach is able to contain virtually any controller in a candidate controller set.
Contact of Rough Surfaces: Combined Elastic and Rate-Dependent Effects

Approximate closed form equations are found for normal and tangential contact forces of rough surfaces in dry friction. Using a viscoelastic asperity behavior, mathematical formulae are derived for normal and tangential components of the contact force that depend not only on the separation of the two surfaces but also the rate of approach and relative sliding. The tangential force over a half-plane, corresponding to the moving direction, is found accounting for the directionality of the tangential component of asperity forces. A statistical approach is forwarded in which dependence of the asperity normal and tangential contact force on relative tangential velocity of two asperities can presented as corrective factors in the mathematical description of normal and tangential force components. These are force directionality corrective coefficient and force-velocity directionality corrective coefficient. Two sets of approximate equations are found for each of the normal and half-plane tangential force components. The simplest forms of the approximate equations achieve accuracy to within five (5) percent error, while other forms yield approximation error within 0.2 percent.Copyright © 2008 by ASME
Mutual subordination of multivariate stationary processes over any locally compact abelian group

Our purpose is to extend Kolmogorov's theorem [5, Th. 10] on mutual subordination for univariate weakly stationary stochastic processes over the (discrete) group of integers to multivariate processes over any (Hausdorff) locally compact abelian (lca) group. This extension is given in Theorems (1.12) and (3.4) below. We shall lean heavily on the joint paper [10] on the decomposition of matricial measures, to which the present paper may be regarded as a sequel.
Pollen nutrition affects honey bee stress resistance

The honey bee, Apis, is perhaps the most beneficial insect to humans because most of our fruits and vegetables depend on them for pollination. Yet these iconic insects have been plagued by many types of stresses. This paper reviews many lines of evidence pointing to the importance of pollen nutrition in honey bee health. In laboratory studies that used caged honey bees, poor pollen nutrition led to a reduction of worker bees’ resistance to the microsporidian, Nosema apis, an increase of bee’s sensitivity to pesticides, and an increased titer of bee virus. On the other hand, polyfloral pollen made bees more resistant to stresses by enhancing their immune related enzyme activities. At the colony level, good pollen nutrition increased honey bee’s resistance to Nosema ceranae or the ectoparasitic mite, Varroa destructor. The effects of both transportation and habitat changes on honey bees seem most likely mediated via decreased diversity, or amount, of pollen to the colonies. Pollen nutrition, therefore, might work together with other factors in reducing the bees’ resistance and exacerbate the effects of viruses, pesticides, or parasites, eventually resulting in Colony Collapse Disorder. Besides paying attention to all of these other factors, pollen nutrition should be an important focus in the future for maintaining healthy bee colonies.
Skin conductance, reaction time, and observational ratings in learning-disabled children

Rates of GSR habituation, reactiontime responses, and observational ratings in normal and learningdisabled children were evaluated. Compared to normals, children with learning disabilities demonstrated faster rates of GSR habituation in a task involving active attention, slower reactiontime responses, and more characteristics of “minimal brain dysfunction” on a rating scale. Within the learningdisability group those subjects with a family history of reading problems showed fewer GSR, reactiontime, and rating responses characteristic of “minimal brain dysfunction.”
Mapping the Protein Phosphatase-2B Anchoring Site on AKAP79 BINDING AND INHIBITION OF PHOSPHATASE ACTIVITY ARE MEDIATED BY RESIDUES 315–360

Compartmentalization of protein kinases and phosphatases with substrates is a means to increase the efficacy of signal transduction events. The A-kinase anchoring protein, AKAP79, is a multivalent anchoring protein that maintains the cAMP-dependent protein kinase, protein kinase C, and protein phosphatase-2B (PP2B/calcineurin) at the postsynaptic membrane of excitatory synapses where it is recruited into complexes with N-methyl-d-aspartic acid or alpha-amino-3-hydroxy-5-methyl-isoxazole-4-propionic acid (AMPA)-subtype glutamate receptors. We have used cellular targeting of AKAP79 truncation and deletion mutants as an assay to map the PP2B-binding site on AKAP79. We demonstrate that residues 315-360 are necessary and sufficient for AKAP79-PP2B anchoring in cells. Multiple determinants contained within this region bind directly to the A subunit of PP2B and inhibit phosphatase activity. Peptides spanning the 315-360 region of AKAP79 can antagonize PP2B anchoring in vitro and targeting in transfected cells. Electrophysiological experiments further emphasize this point by demonstrating that a peptide encompassing residues 330-357 of AKAP79 attenuates PP2B-dependent down-regulation of GluR1 receptor currents when perfused into HEK293 cells. We propose that the structural features of this AKAP79-PP2B-binding domain may share similarities with other proteins that serve to coordinate PP2B localization and activity.
An assay for albumin messenger RNA in an vitro protein synthesizing system from wheat germ

The synthesis of serum albumin in an in vitro protein-synthesizing system from wheat germ stimulated with rat liver polysomal RNA is demonstrated by immunoprecipitation. The newly synthesized albumin has the same electrophoretic mobility as rat serum albumin. There is a linear increase in precursor incorporation into total protein and albumin with increasing RNA concentration. Potassium and magnesium optima for albumin synthesis are different from those for total protein synthesis.
Russellian Facts About the Slingshot

The so-called “Slingshot” argument purports to show that an ontology of facts is untenable. In this paper, we address a minimal slingshot restricted to an ontology of physical facts as truth-makers for empirical physical statements. Accepting that logical matters have no bearing on the physical facts that are truth-makers for empirical physical statements and that objects are themselves constituents of such facts, our minimal slingshot argument purportedly shows that any two physical statements with empirical content are made true by one and the same fact. It is well-known that Russell’s theory of descriptions may be employed to reveal a scope fallacy in the slingshot argument. This paper reveals that there is a quite independent Russellian criticism of the slingshot argument based on the thesis that facts are structured entities.
Tapping into Active Learning and Multiple Intelligences With Interactive Multimedia: A Low-Threshold Classroom Approach.

Educational technology is seldom used to facilitate more active student learning in the classroom. Instructors who have mastered PowerPoint, however, could just as easily learn to create simple pieces of interactive multimedia that encourage student participation in learning tasks and that appeal to multiple intelligences and learning styles. Macromedia Flash animation projects can be used to increase student engagement and to activate peer learning. New multimedia authoring software can create opportunities for effective student-centered learning that were not previously possible.
Role and Optimal Dosing of Angiotensin-Converting Enzyme Inhibitors in Heart Failure

Based on overwhelming data demonstrating reduced morbidity and mortality, ACE inhibitors form a mainstay of therapy in all patients with symptomatic left ventricular systolic dysfunction. Furthermore, ACE inhibitors may be beneficial in the prevention of heart failure in patients with high-risk cardiovascular profiles. However, definite benefit from the use of ACE inhibitors in all patients with heart failure and preserved ejection fraction has not been demonstrated. Even though ACE inhibitors probably have a class effect in patients who have heart failure, it is recommended that ACE inhibitors that have been shown to reduce morbidity and mortality in clinical trials (captopril, enalapril, lisinopril, and ramipril) be used because studies have clearly defined a dose for these agents that is effective in modifying the natural history of the disease. Attempts should be made to up titrate patients to target doses of ACE inhibitors that have been used in clinical trials, if tolerated.
Possible effects of anisotropy ofG on celestial orbits

Will (1971) has discussed a possible anisotropy in the gravitational constantG. Suppose that the attractive gravitational force between two particles of massesm1 andm2 is given by the usual expressionF=−Gm1m2r/r3, wherer is the separation vector. Ifc is the velocity of light in vacuo and if 1r≡r/r, he expresses the anisotropy byG=G∞[1+e(v·1r/c)2], whereG∞ is a constant,v is identified practically as the velocity of the Sun around the galaxy, and e≈1. Will's suggestion is to look for such an effect in the laboratory.
Geochemistry analysis and evolution of a bolson aquifer, basin and range province in the southwestern united states

This paper expands significantly on the major-ion geochemical characterization, evolution, and differentiation of groundwater in the Presidio-Redford Bolson (PRB) Aquifer of Texas as presented in Chowdhury et al. (2008). For 19 groundwater samples from the PRB Aquifer, the author calculated major cation–anion balance errors, equilibrium carbon dioxide partial pressure values and saturation indices for selected minerals. Comparison of major-ion analyses for groundwater from basin margin wells with those for basin center wells is documented and illustrated with ion-concentration maps and Piper and Stiff diagrams and reveals significant increases in concentrations of chloride, sulfate and sodium coupled with notable decrease of calcium in bolson-center well samples. These geochemical changes suggest dissolution of aquifer minerals and cation exchange as groundwater migrates downgradient to the bolson center. The US Geological Survey (USGS) computer code, NETPATH, was used to interpret probable net geochemical mass-balance reactions that potentially have occurred within the PRB Aquifer along groundwater flowpaths from bolson margin to bolson center. For all four upgradient–downgradient well pairs studied, at least three NETPATH models contain cation exchange values; calcium is being exchanged for sodium. The Rio Grande Alluvium Aquifer and Rio Grande River are notably minor sources of recharge to the PRB Aquifer, based on Chowdhury et al. (2008) and geochemical evaluations of this study.
SI-Traceable Spring Constant Calibration of Microfabricated Cantilevers for Small Force Measurement

A variety of methods exist to measure the stiffness of microfabricated cantilever beams such as those used as mechanical sensors in atomic force microscopy (AFM). In order for AFM to be used as a quantitative small force measurement tool, these methods must be validated within the International System of Units (SI). To this end, two different contact techniques were used to calibrate the spring constant of a cantilever beam. First, a dynamic indentation-based method was used to measure the spring constant of a rectangular cantilever beam. These results were then compared against an SI-traceable spring constant measurement from an electrostatic force balance (EFB). The measurements agree within experimental uncertainty and within 2% for spring constants greater than 2 N/m. The use of this cantilever beam as a transfer artifact for in situ AFM cantilever calibration was then evaluated in comparison to the thermal calibration method. Excellent agreement is seen between these techniques, establishing the consistency of the thermal and dynamic indentation methods with SI-traceable contact cantilever calibration for the rectangular cantilever geometry tested.
Peer Participation in Local Government Employee Appraisal

Despite the importance of employee performance appraisal and the generally low regard in which the process is held in local government, there has been little municipal experimentation with peer appraisal—a technique demonstrated elsewhere to be reliable and valid. In this paper previous research on peer rating is reviewed, common reasons for hesitancy in adoption enumerated, and the validity of some of the principal reasons for hesitancy examined in light of the experience of a city which adopted a peer-supplemented system for recognizing outstanding employees. Based upon an analysis of 1,452 appraisals, no evidence was found to support apprehensions that employees deemed outstanding under the peer-supplemented system would be less qualified than their predecessors who were rated by their supervisors. Some evidence to the contrary was found.
Liquid rocket propellant feedline dynamics

An analytical and experimental study of liquid rocket propellant feedline dynamics has been performed. The analytical model, which includes the effects of turbulent flow, distributed and local compliances, bellows, side branches, and structural mounting stiffness, was verified by an experimental program. Water was used as the internal fluid and the dynamic perturbations in pressure and flow were created by a piston pulser. Measurements were made to determine the pressure perturbation amplitude and phase at the line terminal due to a sinusoidal pulser excitation. The frequency response of the various line configurations tested were compared with the computed theoretical results.