cssi/SciSciGPT-SciSciNet huggingface dataset:
Best Approaches to Evaluation and Feedback in Post-Graduate Medical Education.

The objectives of this literature review are to appraise current approaches and assess new technologies that have been utilized for evaluation and feedback of residents, with focus on surgical trainees. In 1999, the Accreditation Council for Graduate Medical Education introduced the Milestone system as a tool for summative evaluation. The organization allows individual program autonomy on how evaluation and feedback are performed. In the past, questionnaire evaluations and informal verbal feedback were employed. However, with the advent of technology, they have taken a different shape in the form of crowdsourcing, mobile platforms, and simulation. Limited data is available on new methods but studies show promise citing low cost and positive impact on resident education. No one “best approach” exists for evaluation and feedback. However, it is apparent that a multimodal approach that is based on the ACGME Milestones can be effective and aid in guiding programs.
A Precise Performance Analysis of Learning with Random Features.

We study the problem of learning an unknown function using random feature models. Our main contribution is an exact asymptotic analysis of such learning problems with Gaussian data. Under mild regularity conditions for the feature matrix, we provide an exact characterization of the asymptotic training and generalization errors, valid in both the under-parameterized and over-parameterized regimes. The analysis presented in this paper holds for general families of feature matrices, activation functions, and convex loss functions. Numerical results validate our theoretical predictions, showing that our asymptotic findings are in excellent agreement with the actual performance of the considered learning problem, even in moderate dimensions. Moreover, they reveal an important role played by the regularization, the loss function and the activation function in the mitigation of the "double descent phenomenon" in learning.
E-cigarette sharing behavior among college students: An exploratory study.

The purpose of this study was to explore sharing behavior among college students who use e-cigarettes. A convenience sample of current e-cigarette users answered questionnaire items regarding shari...
COVID-19 Death Rates Are Higher in Rural Counties With Larger Shares of Blacks and Hispanics.

Purpose This study compared the average daily increase in COVID-19 mortality rates by county racial/ethnic composition (percent non-Hispanic Black and percent Hispanic) among US rural counties. Methods COVID-19 daily death counts for 1,976 US nonmetropolitan counties for the period March 2-July 26, 2020, were extracted from USAFacts and merged with county-level American Community Survey and Area Health Resource File data. Covariates included county percent poverty, age composition, adjacency to a metropolitan county, health care supply, and state fixed effects. Mixed-effects negative binomial regression with random intercepts to account for repeated observations within counties were used to predict differences in the average daily increase in the COVID-19 mortality rate across quartiles of percent Black and percent Hispanic. Findings Since early March, the average daily increase in the COVID-19 mortality rate has been significantly higher in rural counties with the highest percent Black and percent Hispanic populations. Compared to counties in the bottom quartile, counties in the top quartile of percent Black have an average daily increase that is 70% higher (IRR = 1.70, CI: 1.48-1.95, P Conclusion COVID-19 mortality risk is not distributed equally across the rural United States, and the COVID-19 race penalty is not restricted to cities. Among rural counties, the average daily increase in COVID-19 mortality rates has been significantly higher in counties with the largest shares of Black and Hispanic residents.
Dissection and physical mapping of wheat chromosome 7B by inducing meiotic recombination with its homoeologues in Aegilops speltoides and Thinopyrum elongatum.

We constructed a homoeologous recombination-based bin map of wheat chromosome 7B, providing a unique physical framework for further study of chromosome 7B and its homoeologues in wheat and its relatives. Homoeologous recombination leads to the dissection and diversification of the wheat genome. Advances in genome sequencing and genotyping have dramatically improved the efficacy and throughput of homoeologous recombination-based genome studies and alien introgression in wheat and its relatives. In this study, we aimed to physically dissect and map wheat chromosome 7B by inducing meiotic recombination of chromosome 7B with its homoeologues 7E in Thinopyrum elongatum and 7S in Aegilops speltoides. The special genotypes, which were double monosomic for chromosomes 7B’ + 7E’ or 7B’ + 7S’ and homozygous for the ph1b mutant, were produced to enhance 7B − 7E and 7B − 7S recombination. Chromosome-specific DNA markers were developed and used to pre-screen the large recombination populations for 7B − 7E and 7B − 7S recombinants. The DNA marker-mediated preselections were verified by fluorescent genomic in situ hybridization (GISH). In total, 29 7B − 7E and 61 7B − 7S recombinants and multiple chromosome aberrations were recovered and delineated by GISH and the wheat 90 K SNP assay. Integrated GISH and SNP analysis of the recombinants physically mapped the recombination breakpoints and partitioned wheat chromosome 7B into 44 bins with 523 SNPs assigned within. A composite bin map was constructed for chromosome 7B, showing the bin size and physical distribution of SNPs. This provides a unique physical framework for further study of chromosome 7B and its homoeologues. In addition, the 7B − 7E and 7B − 7S recombinants extend the genetic variability of wheat chromosome 7B and represent useful germplasm for wheat breeding. Thereby, this genomics-enabled chromosome engineering approach facilitates wheat genome study and enriches the gene pool of wheat improvement.
Clinical Characteristics and Outcome of Pneumomediastinum in Patients with COVID-19 Pneumonia.

Introduction: Pneumomediastinum (PM) is characterized by the presence of air within the mediastinum. The association between PM and coronavirus 2019 (COVID-19) has not been well established in the current literature. We sought to summarize the limited body of literature regarding PM in patients with COVID-19 and characterize the presentation and clinical outcomes of PM in patients with severe acute respiratory syndrome (SARS)-COV-2 pneumonia at our institution to better define the incidence, prognosis, and available treatment for this condition. Materials and Methods: All patients with a proven diagnosis of COVID-19 and PM between March 18, 2020 and May 5, 2020 were identified through hospital records. Retrospective analysis of radiology records and chart review were conducted. Clinical characteristics and outcomes were collected and descriptive statistics was analyzed. Results: Thirty-six patients met inclusion criteria. Out of the 346 intubated COVID-19 patients, 34 (10%) had PM. The incidence of PM increased for the first 4 weeks of the pandemic, and then began to decrease by week 5. At the endpoint of the study, 12 (33.33%) patients were alive and 24 patients (66.67%) had died. Conclusion: PM, although a rare phenomenon, was more prevalent in COVID-19 patients compared with historical patients with adult respiratory distress syndrome. The etiology of this condition may be attributed to higher susceptibility of patients infected with SARS-CoV-2 to a combination of barotrauma and airway injury.
Simultaneous needle catheter selection and dwell time optimization for preplanning of high-dose-rate brachytherapy of prostate cancer

Purpose Needle catheter positions critically affect the quality of treatment plans in prostate cancer high-dose-rate (HDR) brachytherapy. The current standard needle positioning approach is based on human intuition, which cannot guarantee a high-quality plan. This study proposed a method to simultaneously select needle catheter positions and determine dwell time for preplanning of HDR brachytherapy of prostate cancer. Methods We formulated the needle catheter selection problem and inverse dwell time optimization problem in a unified framework. In addition to the dose objectives of the planning target volume (PTV) and organs at risk (OARs), the objective function incorporated a group-sparsity term with a needle-specific adaptive weighting scheme to generate high-quality plans with the minimal number of needle catheters. The optimization problem was solved by a fast-iterative shrinkage-thresholding algorithm. For validation purposes, we tested the proposed algorithm on 10 patient cases previously treated at our institution and compared the resulting plans with plans generated using needle catheters selected manually. Results Compared to the plan with manually selected needle catheters, when normalizing both plans to the same PTV coverage V100% = 95%, the plans generated by the proposed algorithm reduced median V125% from 65% to 64%, but increased median V150% from 35% to 38%, and V200% from 14% to 16%. All planning objectives were met. All clinically important dosimetric parameters of OARs were reduced. D1cc of bladder and rectum were reduced from 8.57 Gy to 8.50 Gy and from 7.24 Gy to 6.80 Gy, respectively. Dmax of urethra was reduced from 15.85 Gy to 15.77 Gy. The median number of selected needle catheters was reduced by two. The computational time for solving the proposed optimization problem was ~90 seconds using MATLAB. Conclusion The proposed algorithm was able to generate plans for prostate cancer HDR brachytherapy preplanning with increased median conformity index (0.73 to 0.77) and slightly lower median homogeneity index (0.64 to 0.62) with the number of selected needles reduced by two compared to the manual needle selection approach.
Influence of Inverter-Based Resources on Microgrid Protection: Part 1: Microgrids in Radial Distribution Systems

Microgrids are being deployed at a rising rate, primarily as a means of increasing power system resilience. Commonly, a microgrid today includes at least some inverter-based resources (IBRs), and many microgrids have modes or conditions under which they are entirely energized by IBRs. Most microgrids today are deployed on radial distribution circuits, but it is conceivable that they could also be considered for deployment on secondary network systems.
Check-in Phone Calls Six Weeks and Six Months After Musculoskeletal Specialty Care

Health organizations want to measure patient-reported outcome measures (PROMs) longitudinally. Two medical assistants called people selectively at 6 weeks and routinely at 6 months to obtain PROMs ...
Child abuse laws: past, present, and future.

In 1970, a five-month-old baby was admitted to a California hospital. The X-rays showed that his skull was fractured from ear to ear. His mother explained that the baby had fallen off a bed. The child was returned to the mother three days later. Twice within the next four weeks further medical treatment was required for injuries which included whip welts on the back, puncture wounds in the neck, and burned fingertips. The last time he was brought in he had strangulation marks and no respiration. Spontaneous respiration was restored but the baby suffered extensive brain damage. As a result, this small child will be confined in a home for the mentally retarded for the rest of his life. Time reported that The mother's boyfriend was convicted of child beating and sentenced to from one to ten years in prison (the mother.., was not charged ...). Meanwhile, the child's father brought a $5,000,000 suit against four doctors, for failing to report the attacks, and against the city and police chief ... for failing to investigate when another doctor did make charges.[1]
ORIGINAL RESEARCH: Comparative constraint-based model development for thermophilic hydrogen production

Abstract A method for comparative constraint-based model development is presented; the constraint-based model for one organism is modified to create a model for a second organism based on synteny between the two annotated genome sequences. With this method a model was created for Thermotoga neapolitana, using the model for T. maritima as a template. Twenty-five of the 479 genes in the T. maritima model did not have orthologs in T. neapolitana, and the reactions associated with these genes were removed from the model. The T. neapolitana model was verified with flux balance analysis (FBA) and dynamic FBA. Sixteen carbon sources that supported FBA growth simulations for the T. maritima model did not support growth for the T. neapolitana model. Based on the simulations, glycerol and L-rhamnose were tested as T. neapolitana growth substrates, and experimental results confirmed the model prediction that these substrates are not metabolized by T. neapolitana. In addition to the generation of carbon source utiliz...
Prevalence of Chronic Gastritis or Helicobacter pylori Infection in Adolescent Sleeve Gastrectomy Patients Does Not Correlate with Symptoms or Surgical Outcomes.

Abstract Background: In adults undergoing gastric bypass surgery, it is routine practice to perform pre-operative testing for Helicobacter pylori infection. Evidence suggests that infection impairs anastomotic healing and contributes to complications. There currently are no data for adolescents undergoing bariatric procedures. Despite few patients with pre-operative symptoms, we noted occasional patients with H. pylori detected after sleeve gastrectomy. We reviewed our experience with our adolescent sleeve gastrectomy cohort to determine the prevalence of H. pylori infection, its predictive factors, and association with outcomes. We hypothesized that H. pylori infection would be associated with pre-operative symptoms, but not surgical outcomes. Methods: All patients undergoing sleeve gastrectomy at our hospital were included. We conducted a chart review to determine pre- or post-operative symptoms of gastroesophageal reflux disease GERD or gastritis, operative complications, and long-term anti-reflux ther...
Abnormal splice variants of SIVA in Waldenstrom’s macroglobulinemia (WM).

AACR Annual Meeting-- Apr 12-16, 2008; San Diego, CA 2695 Waldenstrom’s macroglobulinemia (WM) is an incurable B cell malignancy characterized by the accumulation of IgM secreting lymphoplasmacytic cells (LPC). Despite intense research efforts, the mechanism(s) by which WM LPC fail to undergo apoptosis remain to be defined. One potential mechanism for B-cell homeostasis is signaling of CD70 through CD27, which induces apoptosis in normal B-cells including CD27+ memory B-cells from which WM LPC are thought to derive. WM cells often show no or diminished expression of CD27, or secrete high levels of soluble CD27 which may lead to CD70 signaling blockade (Ho et al, Blood 2008). As part of these effort we sought to elaborate on intracellular mechanisms for CD70-CD27 signaling, by focusing on SIVA, a pro -apoptotic proteincontaining a death domain which interacts with the cytoplasmic tail of CD27. Two splice variants of SIVA ( SIVA1 and SIVA2) have so far been identified in humans . We therefore evaluated the expression patterns of SIVA in 25 WM patients and 6 healthy donors (HD). Through gene profiling, we detected the constitutive expression of SIVA 1 and its variant SIVA2 , which results from deletion of exon 2. However, in contrast to previous findings, we detected three novel aberrant splice variants of SIVA , which we have designated as SIVA-Va, -Vb, and -Vc, at least one of which alone or combination with each other were present in 25/25 patients with WM versus 1/6 HD (p=0.00004). The breakdown for the frequency of expression for these variants in WM patients was as follows: SIVA -Va (10/25); -Vb (6/25); -Vc (13/25), whereas in HD only SIVA-Vc was present in one individual. Cloning, sequencing and alignment analysis of SIVA variants from 4 WM patients revealed that SIVA-Va and SIVA-Vb resulted from partial intron retention, while SIVA-Vc was derived from the deletion of two exons. DNA alignment and bioinformatics analysis demonstrated that all splice variants of SIVA encoded for novel proteins. This prediction was verified by transient tranfection of GFP-SIVA-FL and DsRed-SIVA variant constructs into HeLa cells. As expected, SIVA-FL protein was expressed in the nucleus and transported to the membrane, while splice variants were localized on the membrane. Co-transfection analysis of SIVA-FL and splice variants verified their co-localization at the membrane 6 hours after proteins production. The results of these studies suggest that SIVA variants compete for CD27 binding and may therefore interfere with B-cell homeostasis regulated by CD70-CD27 interactions.
Alternative worlds as teaching and learning environments

The educational community has traditionally been among the first to evaluate and adopt interactive innovations in information technology. These innovations often provide test beds for educational theorists to explore new methodologies for computer-based instruction. "Alternative worlds" is an exciting new research area for computer scientists specializing in human-computer interaction, social networking, and virtual reality. This paper speculates about how alternative world technologies might affect the future of online instruction.
The Prevalence and Inaccessibility of Internet References in the Biomedical Literature at the Time of Publication

Objectives: To determine the prevalence and inaccessibility of Internet references in the bibliography of biomedical publications when first released in PubMed®. Methods: During a one-month observational study period (Feb 21 to Mar 21, 2006) the Internet citations from a 20% random sample of all forthcoming publications released in PubMed during the previous day were identified. Attempts to access the referenced Internet citations were completed within one day and inaccessible Internet citations were recorded. Results: The study included 4,699 publications from 844 different journals. Among the 141,845 references there were 840 (0.6%) Internet citations. One or more Internet references were cited in 403 (8.6%) articles. From the 840 Internet references, 11.9% were already inaccessible within two days after an article's release to the public. Conclusion: The prevalence of Internet citations in journals included in PubMed is small (<1%); however, the inaccessibility rate at the time of publication is considered substantial. Authors, editors, and publishers need to take responsibility for providing accurate and accessible Internet references.
Cervical radiculopathy, entrapment neuropathy, and thoracic outlet syndrome: how to differentiate?: Invited submission from the Joint Section Meeting on Disorders of the Spine and Peripheral Nerves, March 2004

The common diagnoses of cervical radiculopathy and upper-extremity entrapment neuropathies can at times be difficult to differentiate. Additionally, thoracic outlet syndrome is often diagnosed when, in fact, the problem is radiculopathy or neuropathy. Another source of confusion, especially in older patients, is neuralgic amyotrophy, brachial plexitis, or the Parsonage-Turner syndrome. The differential diagnosis of unilateral arm pain, weakness, and/or sensory loss includes all of these problems. The clinical and electrodiagnostic features of each are discussed as an aid to distinguishing between these common and similar entities.
Constructing Involutive Tableaux with Guillemin Normal Form

Involutivity is the algebraic property that guarantees solutions to an analytic and torsion-free exterior differential system or partial differential equation via the Cartan{Kahler theorem. Guillemin normal form establishes that the prolonged symbol of an involutive system admits a commutativity property on certain subspaces of the prolonged tableau. This article examines Guillemin normal form in detail, aiming at a more systematic approach to classifying involutive systems. The main result is an explicit quadratic condition for involutivity of the type suggested but not completed in Chapter IV,x 5 of the book Exterior Dierential Systems by Bryant, Chern, Gardner, Goldschmidt, and Griffiths. This condition enhances Guillemin normal form and characterizes involutive tableaux.
High-fidelity ac gate operations of a three-electron double quantum dot qubit

Semiconductor quantum dots in silicon are promising qubits because of long spin coherence times and their potential for scalability. However, such qubits with complete electrical control and fidelities above the threshold for quantum error correction have not yet been achieved. We show theoretically that the threshold fidelity can be achieved with ac gate operation of the quantum dot hybrid qubit. Formed by three electrons in a double dot, this qubit is electrically controlled, does not require magnetic fields, and runs at gigahertz (GHz) gate speeds. We analyze the decoherence caused by $1/f$ charge noise in this qubit, find parameters that minimize the charge noise dependence in the qubit frequency, and determine the optimal working points for ac gate operations that drive the detuning and tunnel coupling.
Recent speciation between sympatric Tanganyikan cichlid colour morphs

Lake Tanganyika, Africa's oldest lake, harbours an impressive diversity of cichlid fishes. Although diversification in its radiating groups is thought to have been initially rapid, cichlids from Lake Tanganyika show little evidence for ongoing speciation. In contrast, examples of recent divergence among sympatric colour morphs are well known in haplochromine cichlids from Lakes Malawi and Victoria. Here, we report genetic evidence for recent divergence between two sympatric Tanganyikan cichlid colour morphs. These Petrochromis morphs share mitochondrial haplotypes, yet microsatellite loci reveal that their sympatric populations form distinct genetic groups. Nuclear divergence between the two morphs is equivalent to that which arises geographically within one of the morphs over short distances and is substantially smaller than that among other sympatric species in this genus. These patterns suggest that these morphs diverged only recently, yet that barriers to gene flow exist which prevent extensive admixture despite their sympatric distribution. The morphs studied here provide an unusual example of active diversification in Lake Tanganyika's generally ancient cichlid fauna and enable comparisons of speciation processes between Lake Tanganyika and other African lakes.
Physics of Membrane-Based Desorption Process From LiBr Solution Flow in Microchannels

This study investigates the physics of water desorption from a lithium bromide (LiBr) solution film. The study was conducted on a membrane-based desorber in which the solution flows through an array of microchannels capped by a porous membrane. The membrane allows the vapor to exit the flow and retains the liquid. The solution film velocity and thickness as well as the solution and vapor pressures are independently controlled. Effects of different parameters such as wall temperature, solution and vapor pressures, solution flow velocity, and the solution inlet temperature on desorption rate were studied. Two different mechanisms of desorption are observed and analyzed. These mechanisms consisted of: (1) direct diffusion of water molecules out of the solution and their subsequent flow through the membrane and (2) formation of water vapor bubbles within the solution and their exit through the membrane. Direct diffusion was the dominant desorption mode at low surface temperatures and its magnitude was directly related to the vapor pressure, the solution concentration, and the heated wall temperature. Desorption at the boiling regime was predominantly controlled by the solution flow pressure. Overall, an order of magnitude higher desorption rate compare to a previous study on a membrane-based desorber was achieved.Copyright © 2013 by ASME
The Self-Drawing as an Expression of Perceptual-Motor Dysfunction

Summary A battery of perceptual-motor tests including a self-drawing, was administered to 100 children 6 and 7 years of age with suspected perceptual dysfunction and to 50 children selected without reference to perceptual ability. The difference in mean scores between the two groups on the self-drawing reached statistical significance well beyond the .01 level, favoring the sample of 50. Among the scores of the subjects with dysfunction, correlations between self-drawings and other perceptual tasks were highest with tests involving visual perception and use of a pencil. Associations with tests of somatic perception were also significant but smaller in magnitude. When the contribution of graphic skill to the self-drawing was removed through computation of partial correlations, coefficients between self-drawings and kinesthesia, two-point tactile discrimination, and gross motor planning lost statistical significance but the relationship between self-drawing ability and a visual spatial relations test maintained statistical certitude. It was concluded that, in so far as the construct of a body scheme consists of a neurological model of the sensorimotor aspects of the body, the self-drawing provides a highly limited indication of that status. It is a more effective index of visual perception and the ability to draw lines or forms with a pencil.
Thalamic deep brain stimulation: effects on the nontarget limbs.

Unilateral thalamic ventral intermediate (VIM) deep brain stimulation (DBS) is now accepted as an effective treatment for essential tremor (ET) and tremor related to Parkinson's disease (PD). The effects of unilateral placement on the side ipsilateral to the surgical site have not been carefully evaluated. To systematically assess the effects ipsilateral to the surgical side and to determine the effects of device inactivation on the baseline tremor, we evaluated tremor in 73 patients approximately 3 months after their unilateral thalamic placement. Assessment included blinded and unblinded ratings using the Unified Parkinson's Disease Rating Scale for PD patients and a modified Tremor Rating Scale in ET patients. All measures of tremor contralateral to the implantation site improved significantly and robustly in both PD and ET. Implantation did not worsen tremor by any measure on the ipsilateral side. There was mild ipsilateral improvement as measured by lower observed tremor scores in ET (6.0 +/- 1.8 to 5.0 +/- 1.9, P < 0.005), but not PD. There was no rebound augmentation of tremor in either hand after the devices were deactivated in either group. We conclude that VIM DBS may mildly improve ipsilateral ET, and that concerns about meaningful ipsilateral tremor augmentation after device deactivation are not warranted.
Lipschitz continuity of H ∞ sensitivity optimization for continuous-time systems

Subject to certain high frequency attenuation conditions on weighting functions and plants, a suboptimal sensitivity function can be constructed which satisfies certain Lipschitz continuity conditions. The Lipschitz conditions accommodate possible perturbations in system delay terms and those causing plant zeros cross the imaginary axis.
Intestinal permeability in newborns with necrotizing enterocolitis and controls: Does the sugar absorption test provide guidelines for the time to (re-)introduce enteral nutrition?

Abstract Background: In necrotizing enterocolitis (NEC), (sub)mucosal edema, hemorrhage, ulceration, or necrosis will disturb intestinal integrity, as reflected by an increased intestinal permeability. Enteral substrate is therefore withheld for a variable period up to 3 weeks (in many clinics). The authors used the sugar absorption test to measure intestinal permeability changes in surgically treated necrotizing enterocolitis patients and surgical controls to evaluate the usefulness of this test in timing the (re-)introduction of enteral feeding in NEC patients as intestinal integrity recovers. Methods: Changes in intestinal permeability to lactulose and rhamnose were evaluated prospectively in 13 children with NEC and 10 operated control patients. The patients were given 1 mL/kg body weight lactulose/rhamnose solution at different time intervals after admission. The lactulose to rhamnose (L/R) ratio was determined by gaschromatography in 4-hour urine samples. Results: The L/R ratios in NEC patients were increased for prolonged periods of time with a tendency to decrease in the third week after the start of NEC. However, in some cases, the increased L/R ratios even exceeded the 3-week period of starvation. High peaks in the L/R ratio were seen in patients suffering from bowel perforation or sepsis. Compared with necrotizing enterocolitis patients, L/R ratios of control patients were increased only in the first days after surgery and normalized more rapidly. The results of the L/R tests in this study corroborated the clinical condition of the patients. Conclusions: The sugar absorption test shows an individual variability in the recovery of intestinal permeability in a group of seriously ill newborns with advanced stages of NEC. An individual approach in restarting enteral nutrition seems to be justified; however, the optimal time-point to restart enteral nutrition cannot be determined by the sugar absorption test alone. Combining parameters of intestinal integrity and function could enable a more accurate determination of this optimal timepoint. J Pediatr Surg 36:587-592. Copyright © 2001 by W.B. Saunders Company.
Degradation and solubilization of pectin by β‐galactosidases purified from avocado mesocarp

Three β-galactosidase (EC 3. 2. 1. 23) isozymes were purified from the mesocarp of ripe fruit of Persea americana Mill. cv. Lula. and their effects on pectin derived from mature-green tomato fruit were investigated. The β-galactosidases had pl values of 5. 0,5. 1 and 5. 2. and molecular weights of 41. 49 and 54 KDa. respectively. There was a partial degradation of pectin resulting in the release of monomeric galactose upon treatment with avocado β-galactosidase. This degradation resulted in increased pectin solubility and decreased apparent average molecular size as determined by microfiltration and gel permeation by high-performance liquid chromatography. The increase in solubility was due. in part. to an apparent decrease in the ability of pectin molecules to aggregate together.
PHOTOSENSITIZED LYSIS OF LIPOSOMES BY HEMATOPORPHYRIN DERIVATIVE

The spectral properties and efficiency for photosensitizing the lysis of phosphatidylcholine liposomes have been measured for the components of hematoporphyrin derivative (Hpd) after alkaline hydrolysis and fractionation by polyacrylamidc gel chromatography. Two major and two minor Hpd fractions have been identified whose spectral properties correlate with the anoxic sensitizing efficiency and the oxygen enhancement ratio (OER). The fastest moving fraction, which is the putative biologically active component, comprised one-third of the starting material and had OER = 2.7. Liposome lysis by this fraction was inhibited in the presence of human serum albumin at concentration ratios comparable to those employed for photoradiation therapy. The present results show that Hpd can act as an oxic and anoxic photosensitizer of a model biomembrane and suggest that separation from serum proteins is required for in vivo photosensitization.
Parenting behaviours among low‐income mothers of preschool age children in the USA: implications for parenting programmes

This study examines the overall quality of parenting behaviours among low‐income mothers in the USA and the extent to which they are influenced by risk factors within the family environment, maternal well‐being and maternal risk characteristics associated with socio‐economic status. Participants consisted of 1070 low‐income mothers of three‐year‐old children who were enrolled in the Early Head Start (EHS) Research and Evaluation Project. Data were collected using structured interviews with the mothers and from videotaped mother–child interactions during play activities when children were age three. Findings indicated that less‐positive parenting behaviours and fewer supports for language and learning were predicted by higher family conflict, higher parental distress and maternal social risk factors including younger age, less education and a history of public assistance. Fewer household resources also predicted fewer supports for language and learning, but not positive parenting. Negative parenting behavi...
Nonparametric linkage analysis using person-specific covariates.

Linkage analysis provides an important tool for mapping genes for complex disease. However its usefulness has been limited by inadequate marker density, inadequate sample sizes and the possibility that different genes account for different subtypes of the disease (phenotypic heterogeneity). The first two limitations can be addressed by high-density single nucleotide polymorphism (SNP) genotyping and the pooling of large sets of multiple-case families. Phenotypic heterogeneity can be addressed by analyses that weigh the contributions of affected family members according to characteristics of their disease phenotypes. Here we introduce a method for including such person-specific weights in nonparametric linkage analysis. We show with simulations that such weighting can provide stronger linkage signals when a causal polymorphism affects some manifestations of the disease more than others. We applied the method to prostate cancer linkage data in a region on chromosome 19p, and obtained higher lod scores by assigning weights of one to men with early-onset aggressive cancers, weights of zero to those with late-onset nonaggressive cancers, and intermediate weights to all other affected men. We have developed a modified version of GENEHUNTER that allows inclusion of person-specific weights in the nonparametric analyses. This program is freely available at http://med.stanford.edu/epidemiology/statisticalSoftware/weightedKAC. Genet. Epidemiol. 2006. © 2006 Wiley-Liss, Inc.
Hopf-algebraic structure of families of trees

In this paper we describe Hopf algebras which are associated with certain families of trees. These Hopf algebras originally arose in a natural fashion: one of the authors [5] was investigating data structures based on trees, which could be used to efficiently compute certain differential operators. Given data structures such as trees which can be multiplied, and which act as higherorder derivations on an algebra, one expects to find a Hopf algebra of some sort. We were pleased to find that not only was there a Hopf algebra associated with these data structures, but that it could be used to give new proofs of enumerations of such objects as rooted trees and ordered rooted trees. Previous work applying Hopf algebras to combinatorial objects (such as [10], [13] or [14]) has concerned itself with algebraic structures on polynomial algebras and on partially ordered sets, rather than on trees themselves.
Design and Testing of the American Airlines Prototype B-747 AIDS System

American is currently entering the evaluation phase of its B-747 AIDS (Aircraft Integrated Data System) Program. Prior experience focused attention upon the number of engine parameters to be monitored including parameter accuracy and repeatability. The B-747 prototype system design utilizes increased sampling rates, improved sensors and transducers, and solid state electronics. Analysis of AIDS engine data indicates that the increased sampling rates are required for engine pressure measurements but that the high sampling rates for engine speed are not required. Preliminary results indicate that the increased number of engine parameters will allow isolation of faults to particular engine components such as the high compressor, low turbine, etc. The experience gained to date from this program is portrayed including the status of the B-747 AIDS program objectives. Data utilization is briefly discussed.
The current state of antiplatelet therapy in acute coronary syndromes: The data and the real world

Managing antiplatelet therapy for patients with acute coronary syndromes (ACS) is complex, and current therapy options and approaches for these patients are suboptimal. Despite the use of available antiplatelet therapies--aspirin, clopidogrel, and the parenteral glycoprotein IIb/IIIa inhibitors--recurrence of ischemic events in patients with ACS continues to rise over time. Moreover, bleeding remains an important--and often underappreciated--risk with these therapies, and national registries demonstrate that dosing of antiplatelet therapies frequently strays from evidence-based guidelines. Recent quality-improvement initiatives developed in conjunction with national registries of patients with ACS promise to improve adherence to guidelines through hospital-specific performance reports. More evidence-based use of existing and emerging antiplatelet agents has the potential to improve both ischemic and bleeding outcomes in patients with ACS.
Biological markers in Lower Jurassic synrift lacustrine black shales, Hartford basin, Connecticut, U.S.A.

Abstract The East Berlin Formation (Lower Jurassic, Hartford basin, Connecticut, U.S.A.) is distinctive for its six cyclic units of lacustrine black shale and gray mudstone, separated by playa and fluvial redbeds. The black shales are each about a meter thick and were deposited in subtropical, thermally strastified, oligomictic lakes, the youngest of which (lakes 3 through 6) were large enough to flood most of the basin and attained depths of several tens of meters. The saturate fractions of solvent extracts of organic-rich black shales from each of the six lakes, collected at fresh roadcuts near East Berlin, are dominated by extended homologous series of n-alkanes, alkylcyclohexanes, and branched chain alkanes. A striking feature of the black shales is the presence of a series of extended tricyclic terpanes from C20 to at least C41. Hopanes are either not detectable or present only in subordinate quantities relative to the tricyclic terpanes. The samples are depleted in hopanes in part because of the elevated maturity level (mid to late oil window). Tricyclic terpane concentrations may also have been enhanced by fractionation effects related to oil expulsion out of the black shales. In addition, the original organic matter may have been exceptionally rich in tricyclic terpane precursors, i.e. fossil lipids of prokaryotes present in anoxic, moderately saline, alkaline lakes.
Direct observations of the deuterium-induced surface reconstruction of the Ni(110) plane

The reconstruction of the Ni(110) plane induced by the adsorption of deuterium has been investigated in atomic detail with the field ion microscope. Small clusters of Ni atoms were observed to rearrange from a bulk-terminated structure to a ''missing-row'' structure upon exposure to 10/sup -8/-Torr deuterium at 165--175 K. The observed structure is inconsistent with the ''paired-row'' structure deduced from low-energy electron diffraction and ion-scattering measurements
Interactions of Dimethyl Sulfoxide with Lipid and Protein Monolayers

Phospholipids, cholesterol, protein, and mixed phos-pholipid-protein monolayers were used as models to study interactions between dimethyl sulfoxide and cell membranes. Surface pressure measurements were used to study these dimethyl sulf-oxide-film interactions. While films of dipalmitoyl lecithin, egg lecithin, and cholesterol showed no interaction with dimethyl sulfoxide, films of bovine serum albumin exhibited a significant condensation effect. The degree of film condensation was found to be a function of pH and dimethyl sulfoxide concentration in the subphase. It was postulated that the observed effect of dimethyl sulfoxide on albumin films is due to the loss of protein from the surface. Lipid-protein films showed only small condensation effects in the presence of dimethyl sulfoxide, indicating that the phospholipids protect the protein from attack by dimethyl sulfoxide. These studies indicate that the remarkable penetration abilities of dimethyl sulfoxide may be due to some alteration of protein structure as a result of dehydration at the biomembrane.
Memento: unifying content and context to aid webpage re-visitation

While users often revisit pages on the Web, tool support for such re-visitation is still lacking. Current tools (such as browser histories) only provide users with basic information such as the date of the last visit and title of the page visited. In this paper, we describe a system that provides users with descriptive topic-phrases that aid re-finding. Unlike prior work, our system considers both the content of a webpage and the context in which the page was visited. Preliminary evaluation of this system suggests users find this approach of combining content with context useful.
NSCLC in the Elderly—The Legacy of Therapeutic Neglect

Although the majority of patients diagnosed with non-small cell lung cancer (NSCLC) are elderly, most clinical trials available to guide care either exclude the elderly or underrepresent them. This disregard for the elderly lung cancer patient extends to the clinical realm, where the elderly with lung cancer are less likely to be treated with either curative, or life-extending, palliative therapy. Few elderly-specific phase III trials are available to provide level I evidence. However, subgroup analyses and meta-analyses of large clinical trials enrolling substantial numbers of elderly patients are available to guide care, although these are potentially subject to selection bias. These trials suggest that the fit elderly derive as much benefit from surgery, chemoradiation, and platinum-based doublet chemotherapy as younger patients across all stages of disease. For the less fit elderly, in particular those with limited performance status or significant co-morbidities, less aggressive regimens are likely preferred, with the goal of extending life and delaying or suppressing cancer symptoms. Ultimately, care decisions must incorporate knowledge of the literature, evaluation of the patient's clinical characteristics, and patient priorities. The elderly should be aggressively recruited to clinical trials, including elderly-specific trials and trials of patients with limited performance status and co-morbidities.
Open-mindedness and muddled minds: Fusion in confusion

During one of the few classic moments in my teaching career, several students accused me of being narrow-minded. Always suspicious that my mind was more narrow than broad, I admitted to the class that I may be narrow-minded. Not about to end the discussion on such a low note (at least for me), I asked each of these students to describe their thinking. "I am open-minded," each said, almost before I could finish the question. "Is it possible," I continued, "that you are narrow-minded? .... No," they replied one after the other, "I am openminded." Few students admit that they are narrow-minded or closed-minded. Their minds are flung open, like the gates of heaven to saints. Narrow-mindedness or closed-mindedness is a lapse in character or at best uncomely. One of the educator's fundamental tasks is to make students aware of their narrowmindedness and to have them aspire to the ideal of the open mind. What this open mind is and how it is to be realized within our students is my chief concern as an educator. The Pythian goddess at the oracle of Delphi pronounced Socrates as the wisest of all human beings. Socrates discovered that his wisdom consisted of knowing his ignorance. A corollary to this lesson is that open-mindedness is contingent upon realizing the real possibility of slipping into narrowmindedness or closed-mindedness. This point is illustrated in the Meno, as the slave boy discovers that doubling the side of square will not create double the space:
Embeddedness, Milieu, and Innovation among High-Technology Firms: A Richardson, Texas, Case Study

The author seeks to contribute to the debate on embeddedness, milieu, and innovation in industrial districts through a case study of high-technology firms in Richardson, an inner-ring suburban city of the Dallas–Fort Worth Metropolitan area. Richardson is important because it can be clearly defined as an industrial district, with over 600 high-technology firms and 70 000 employees. The results suggest that the district is robust and highly innovative with considerable capacity for self-sustaining growth. The firms are well integrated, locally and nationally. Despite extensive formal connections, firms' relationships are not very embedded locally. The link between embeddedness and innovation is subtle at best, and is confined to a small set of the most highly innovative firms. Similarly, evidence of a well-established industrial milieu was not forthcoming, although it may be emerging. The relationship between milieu and innovation was vague and was confined to the most innovative firms. The long-term viabi...
Hemoglobin AIc as a model for the development of the sequelae of diabetes mellitus

Hemoglobin A Ic is a glycosylated form of hemoglobin A, the level of which is an integrated index of a person's blood-sugar concentration over the previous several weeks. Measurement of the level of hemoglobin A Ic offers a new means of assessing the degree of carbohydrate control in diabetic patients.
Ca segregation and step modifications on cleaved and annealed MgO(100) surfaces

Abstract Cleaved MgO(100) surfaces were annealed in situ, in a UHV electron microscope, and ex situ, in alumina furnaces, to study changes in surface topography and composition. Steps on surfaces cleaved in air were imaged directly by reflection electron microscopy. They were shown to remain unchanged by in situ annealing procedures used for surface cleaning in contrast to previous studies with indirect decoration imaging which had not revealed steps on cleaned air-cleaved MgO(100) surfaces. The surface steps were found to be predominantly parallel to the MgO〈010〉 crystallographic directions with average terrace lengths of about 80 nm, in agreement with previous studies of in situ cleaved surfaces. Segregation of Ca to the surface was confirmed in annealing experiments between 1000–1700°C and was found to change the step directions and distribution. Straight steps in 〈011〉 directions and curved steps separated by larger terraces were observed. Ca-rich line structures with typical lengths of about 100 and periodicity of 0.3 nm were found commensurately aligned with the MgO〈011〉 direction on the terraces and around the steps of crystals with 270 ppm Ca.
2011 Vascular Research Initiatives Conference: basic foundations of translational research in vascular disease

The Vascular Research Initiatives Conference (VRIC) is an annual conference organized by the Society for Vascular Surgery (SVS). The 2011 VRIC was held in Chicago (IL, USA) to precede and coincide with the first day of the meeting of the Council on Arteriosclerosis, Thrombosis and Vascular Biology (ATVB) of the American Heart Association. The event is designed to present world class vascular research results, encourage collaboration between vascular surgeons and basic scientists in related disciplines, as well as to stimulate interest in research among aspiring academic vascular surgeons. The 2011 VRIC featured plenary sessions addressing peripheral arterial disease, vascular endothelium and thrombosis, aneurysms, and stem cells and tissue engineering. Recipients of the SVS partner grants with the National Institutes of Health K08 awardees presented their progress reports, and keynote addresses were given by Linda Graham and Frank LoGerfo.