cssi/SciSciGPT-SciSciNet huggingface dataset:
The structure of the algebraic eigenspace to the spectral radius of eventually compact, nonnegative integral operators

Let K be an eventually compact linear integral operator on Lp(Ω, μ), 1 ⩽ p < ∞, with nonnegative kernel k(x, y), where the underlying measure μ is totally σ-finite on the domain set Ω when p = 1. This work extends the previous analysis of the author who characterized the distinguished eigenvalues of K and K∗, and the support sets for the eigenfunctions and generalized eigenfunctions belonging to the spectral radius of K or K∗. The characterizations of the support sets for the algebraic eigenspaces of K or K∗ are phrased in terms of significant k-components which are maximal irreducible subsets of Ω and which yield a positive spectral radius for the integral operator defined by the restriction of k(x, y) to the Cartesian product of such sets. In this paper, we show that a basis for the functions, constituting the algebraic eigenspaces of K and K∗ belonging to the spectral radius of K, can be chosen to consist of elements which are positive on their sets of support, except possibly on sets of measure less than some arbitrarily specified positive number. In addition, we present necessary and sufficient conditions, in terms of the significant k-components, for both K and K∗ to possess a positive eigenfunction (a.e. μ) corresponding to the spectral radius, as well as necessary and sufficient conditions for the sequence ∥ γnKng ∥p to converge whenever g⩾ 0, where ∥ − ∥p denotes the norm in Lp(Ω, μ), and γ1 the smallest (in modulus) characteristic value of K. This analysis is made possible by introducing the concepts of chains, lengths of chains, height, and depth of a significant k-component as was done by U. Rothblum [Lin. Alg. Appl. 12 (1975), 281–292] for the matrix setting.
Epigenetic regulation of germ cell differentiation

Germ cells and somatic cells have the identical genome. However, unlike the mortal fate of somatic cells, germ cells have the unique ability to differentiate into gametes that retain totipotency and produce an entire organism upon fertilization [1]. The processes by which germ cells differentiate into gametes, and those by which gametes become embryos, involve dramatic cellular differentiation accompanied by drastic changes in gene expression, which are tightly regulated by genetic circuitries as well as epigenetic mechanisms [2,3]. Epigenetic regulation refers to heritable changes in gene expression that are not due to changes in primary DNA sequence. The past decade has witnessed an ever-increasing understanding of epigenetic regulation in many different cell types/tissues during embryonic development and adult homeostasis. In this review, we focus on recent discoveries of epigenetic regulation of germ cell differentiation in various metazoan model organisms, including worms, flies, and mammals.
Dropsy, Dialysis, Transplant: A Short History of Failing Kidneys

Steven J. Peitzman, Dropsy, Dialysis, Transplant: A Short History of Failing Kidneys. Baltimore, MD: Johns Hopkins University Press, 2007. xvii + 213 pp. $24.95. ISBN: 9780801887345. Kidneys are wh...
The effects of ethnicity and acculturation on early adolescent delinquency.

We examined the influence of ethnicity and acculturation status on the relationship between parental monitoring, susceptibility to antisocial peer pressure, and delinquency. The sample consisted primarily of Caucasian (63%) and Mexican-American (24%) early adolescents. Self-report data were collected from 1021 sixth and seventh graders, equally divided by gender (mean age =12.7 years). The Mexican-American adolescents were categorized into one of three acculturation groups: (a) acculturated; (b) unacculturated by choice; and (c) recent immigrants. Acculturated Mexican-American early adolescents reported significantly more delinquent behaviors than the Caucasian, unacculturated by choice, and recent immigrant youth. Recent immigrant early adolescents reported more parental monitoring than the acculturated Mexican-American early adolescents. Level of perceived susceptibility to antisocial peer pressure did not differ between ethnic or acculturation groups. Regression analyses revealed that the relationship between parental monitoring and delinquency was mediated by susceptibility to antisocial peer pressure for all the groups regardless of ethnicity or level of acculturation. Findings emphasize the importance of: (a) examining level of acculturation when sampling ethnically diverse populations; and (b) comparing global mean level differences and specific relationships among independent variables.
Search for an endotherm in chloroplast lamellar membranes associated with chilling-inhibition of photosynthesis☆

Abstract The phase transition of chloroplast lamellar membrane lipids has been proposed to be the underlying cause of chilling-induced inhibition of photosynthesis in sensitive plants. Differential scanning calorimetry has been used to search for any endotherms arising from lipid state changes in chloroplast lamellar membranes of the chilling-sensitive plants cantaloupe, kidney bean, domestic tomato, and soybean. For comparison, calorimetric scans of chloroplast lamellar membranes from the chilling-insensitive plants spinach, pea, and wild tomato were made. A large reversible endotherm, extending from below 10 ° to nearly 40 °C, was observed in chloroplast membranes from tomatoes of both chilling-sensitive ( Lycopersicon esculentum Mill. cv. Floramerica) and chillinginsensitive ( L. hirsutum LA 1361) species. A much smaller endotherm, approximately 5 to 10% of the area of that seen in the two tomato species, and extending over a similar temperature range, was detected in chloroplasts from chilling-insensitive spinach and peas, and also was generally observed in chloroplasts from chilling-sensitive cantaloupe, kidney bean, and soybean. The enthalpy of these smaller endotherms indicates that, if the endotherm arose entirely from a lipid transition, then it corresponded to the melting of less than about 10% of the total membrane polar lipid. On the basis of these data it is concluded that there is no correlation between chilling sensitivity of photosynthesis and the presence or absence of a phase transition of bulk membrane lipids of the chloroplast lamellar membrane at temperatures above 5 °C.
Modular decomposition and reliability computation in stochastic transportation networks having cutnodes

Consider a flow network having random arc capacities and having associated with each node n a “supply-demand random variable” Yn whose absolute value equals the supply available at the node when Yn assumes a non-negative value and the demand required by the node when Yn assumes a nonpositive value. A fundamental problem is the computation of the reliability R, that is, the probability that the random variables will assume values that permit a feasible flow. Upon adapting the graph-theoretic concepts of “cutnode” and “block,” it is possible to identify a “block-module,” an independent, nontrivial subnetwork that has one and only one node (the “cutnode”) connected to nodes outside the subnetwork. The reliability of the network will increase by a known factor after a “block-modular decomposition” that consists of a transformation of the cutnode's supply-demand random variable and the deletion of the remainder of the block module. Provided the original network possesses at least one block module, R can be determined from a sequence of block-modular decompositions that reduce the original network to a single node whose reliability is easily computed. Computational experience with a computer implementation of such a decomposition method is reported, and the application of the method to the analysis of electrical power networks is included.
Thoracoabdominal-median sternotomy for resection of primary adrenal carcinoma extending into inferior vena cava and hepatic vein

A technique utilizing a combined thoracoabdominal-median sternotomy approach is described for stimulatenous resection of a large adrenal cancer occluding the inferior vena cava and extending into the left hepatic vein. This technique is useful in removint an extensive extension of a renal or adrenal cancer into the inferior vena cava.
The early gene E74B isoform is a transcriptional activator of the ecdysteroid regulatory hierarchy in mosquito vitellogenesis.

Abstract In the mosquito Aedes aegypti, blood feeding activates vitellogenesis that involves yolk protein precursor (YPP) genes in an insect metabolic tissue, the fat body. Vitellogenesis is regulated by the 20-hydroxyecdysone (20E) regulatory hierarchy, in which the Ets-domain protein E74 is a key transcriptional regulator. The mosquito AaE74 gene encodes two isoforms—AaE74A and AaE74B. Both AaE74 isoforms are 20E-inducible early gene products. AaE74B reaches its maximal expression at 10−7 M of 20E, while AaE74A requires 10−6 M of 20E, a concentration at which the YPP genes reach their maximal induction level. In transfection assay, AaE74B is capable of activating a reporter construct containing E74-response elements, while expression of AaE74A has no effect on the basal levels of the reporter. The AaE74B binding activity is present in the fat body nuclei only during active vitellogenesis. Taken together, our findings demonstrate that AaE74B isoform plays the role of a transcriptional activator during vitellogenesis.
Kinetics and mechanism of methane, methanol, and dimethyl ether C-H activation with electrophilic platinum complexes.

The relative rates of C−H activation of methane, methanol, and dimethyl ether by [(N-N)PtMe(TFE-d_3)]+ ((N-N) = ArN═C(Me)−C(Me)═NAr; Ar = 3,5-di-tert-butylphenyl, TFE-d_3 = CF_3CD_2OD) (2(TFE)) were determined. Methane activation kinetics were conducted by reacting 2(TFE)-^(13)C with 300−1000 psi of methane in single-crystal sapphire NMR tubes; clean second-order behavior was obtained (k = 1.6 ± 0.4 × 10^(-3) M^(-1) s^(-1) at 330 K; k = 2.7 ± 0.2 × 10^(-4) M^(-1) s^(-1) at 313 K). Addition of methanol to solutions of 2(TFE) rapidly establishes equilibrium between methanol (2(MeOD)) and trifluoroethanol (2(TFE)) adducts, with methanol binding preferentially (K_(eq) = 0.0042 ± 0.0006). C−H activation gives [(N-N)Pt(CH_2OD)(MeOD)]^+ (4), which is unstable and reacts with [(RO)B(C_6F_5)_3]^- to generate a pentafluorophenyl platinum complex. Analysis of kinetics data for reaction of 2 with methanol yields k = 2.0 ± 0.2 × 10^(-3) M^(-1) s^(-1) at 330 K, with a small kinetic isotope effect (k_H/k_D = 1.4 ± 0.1). Reaction of dimethyl ether with 2(TFE) proceeds similarly (K_(eq) = 0.023 ± 0.002, 313 K; k = 5.5 ± 0.5 × 10^(-4) M^(-1) s^(-1), k_H/k_D = 1.5 ± 0.1); the product obtained is a novel bis(alkylidene)-bridged platinum dimer, [(diimine)Pt(μ-CH_2)(μ-(CH(OCH_3))Pt(diimine)]^(2+) (5). Displacement of TFE by a C−H bond appears to be the rate-determining step for all three substrates; comparison of the second-order rate constants (k(_(methane))/k(_(methanol)) = 1/1.3, 330 K; k(_(methane))/k(_(dimethyl ether)) = 1/2.0, 313 K) shows that this step is relatively unselective for the C−H bonds of methane, methanol, or dimethyl ether. This low selectivity agrees with previous estimates for oxidations with aqueous tetrachloroplatinate(II)/hexachloroplatinate(IV), suggesting a similar rate-determining step for those reactions.
Duplicated Spot 14 genes in the chicken: characterization and identification of polymorphisms associated with abdominal fat traits.

Abstract In mammals, thyroid hormone responsive Spot 14 (THRSP) is a small acidic protein that is predominately expressed in lipogenic tissue (i.e., liver, abdominal fat and the mammary gland). This gene has been postulated to play a role in lipogenesis, since it responds to thyroid hormone stimulation, high glucose levels and it is localized to a chromosomal region implicated in obesity. In this paper, we report the identification and characterization of duplicated polymorphic paralogs of Spot 14 in the chicken, THRSPα and THRSPβ . Despite low similarity in amino acid (aa) sequence between chickens and mammals, other properties of Spot 14 (i.e., pI, subcellular localization, transcriptional control and functional domains) appear to be highly conserved. Furthermore, a synteny group of THRSP and its flanking genes [NADH dehydrogenase ( NDUFC2 ) and glucosyltransferase ( ALG8 )] appears to be conserved among chickens, humans, mice and rats. Polymorphic alleles, involving a variable number of tandem repeats (VNTR), were discovered in the putative protein coding region of the duplicated chicken THRSPα (9 bp) and THRSPβ (6 or 12 bp) genes. Our study shows that the THRSPα locus is associated with abdominal fat traits in a broiler×Leghorn resource population.
Impact of etching on doping profiles in CZ silicon photo-diodes

Abstract The technique of differential voltage contrast (DVC) measurement was developed in our laboratory several years ago. The viability of DVC measurement for determining parameters such as doping profiles has been clearly demonstrated. In this paper, we use DVC to study differences in doping profiles on CZ silicon photo-diodes using two well known surface processing methods. KOH etched wafers showed almost square pits, 100 μm in length. The presence of these etch pits caused, in spin on glass technology, a graded doping profile. On the other hand, samples etched in 5:3:1 solution (HF:HNO 3 :CH 3 COOH) had steep doping gradients. The distribution of spin on glass diffusant, deposited after the above processing, for the two groups of samples seems to be responsible for the variation in the diffusion profile.
Organizational learning: A tool for diversity and institutional effectiveness

Organizational learning, along with a framework for diversity, is an effective approach for campuses seeking sustained institutional change with regard to diversity.
Age-dependent levels of plasma neuropeptides in normal children.

Abstract Several neuropeptides are secreted in high amounts in pediatric tumors such as neuroblastoma and have been used as markers of residual or recurrent disease. Plasma levels of neuropeptides might be expected to change during development, but have not been determined in normal children. We have obtained fresh plasma from cord blood of six full-term infants and from peripheral blood in 41 healthy children, ages 1 month to 21 years. Levels of six neuropeptides, vasoactive intestinal peptide (VIP), somatostatin, gastrin releasing peptide (GRP), substance P, pancreastatin and neuropeptide Y (NPY) were measured by radioimmunoassay along with insulin-like growth factor-1 (IGF-1) whose plasma levels are known to vary during development. A child with neuroblastoma was treated with the somatostatin analogue, octreotide, and the effect on plasma neuropeptides quantified. Octreotide doses of 2–3 μg/kg daily resulted in a 40–60% decrease in plasma levels of IGF-1, pancreastatin and GRP. These results are the first publication of plasma neuropeptide levels in normal children.
Obstetric and Cryptoglandular Rectovaginal Fistulas: Long-term Surgical Outcome; Quality of Life; and Sexual Function

Purpose Rectovaginal fistula (RVF) repair can be challenging. Additionally, women may experience sexual dysfunction and psychosocial ramifications even after a successful repair. The aim of this study was to investigate variables looking for predictors of healing/failure and examine long-term quality-of-life (QOL) and sexual function in women with low RVF from obstetrical or cryptoglandular etiology
On the need to count past two in our thinking about gender and science

Abstract Recent work on the relation between gender and science brings to the fore the need to develop better ways of thinking about both gender and science than we have had in the past. Not simply determined either by anatomy or by culture, the category of gender is neither infinitely plastic nor limited to two options, male and female. Similarly the production of scientific knowledge cannot be accounted for by models of naive realism, or by total realtivism: Science is neither a mirror of culture. With this much understood, we can begin to unravel the kinds of substantive influence our conceptions of science have historically had on each other, without inviting overly simplistic notions of either a “Masculine” or a “Feminine” science.
Isotopic fractionation in the sputtering of 92Mo-100Mo targets

Collector-type experiments have been conducted using isotopically enriched Mo targets to investigate nonstoichiometric effects in sputtering induced by 5 and 10 keV Ar^+ and Xe^+ ions. Sputtered Mo was collected on carbon foils and subsequently analyzed using SIMS to quantify variations in the ^(92)Mo: ^(100)Mo ratio as a function of emission angle in the sputtering geometry and projectile fluence. In general, the sputtered material was found to be enriched in the light isotope, with the enrichment being most pronounced in near-normal emission directions. This angular dependence was clearly resolved at the lowest bombarding fluences, although it was also seen under steady-state conditions. The most extreme low-fluence angular variation was seen for 5 keV Xe^+ bombardment at a fluence of 3.0 × 10^(14) ions cm^(−2), for which the sputtered light-isotope enrichment was ∼ 30%o larger in near-normal emission directions than in oblique directions. The low-fluence angular variation was observed to have a projectile dependence. In the near-normal direction, light-isotope enrichments as large as 53 ± 5%o with respect to the steady-state ratio at the same angle were measured. Similar results were found for secondary Mo^+ ions sputtered by 14.5 keV O^−. The observed effects are generall consistent with other low-fluence measurements of sputtered neutrals and secondary ions from solid targets, and with the results of multiple-interaction computer simulations, but do not agree well with the predictions of analytic theory.
Electron stimulated desorption induced by the scanning tunneling microscope

The use of the scanning tunneling microscope (STM) as an excitation source and a probe of electron stimulated desorption on the atomic scale is reviewed. The case of H desorption from H-terminated Si(001) is examined in detail. Experimental results on excitation thresholds, desorption cross-sections, isotope effects and site-selectivities are presented. Evidence for mechanisms involving direct electronic and hot ground-state desorption, as well as a novel multiple-vibrational excitation mechanism is discussed. Using the latter mechanism, the ultimate resolution limit of selective single atom desorption is achieved. New results on desorption from Si dihydride, including a proposed mechanism for the STM-induced HSi(001)-3 × 1 to 2 × 1 conversion, are presented. Possible applications of STM-induced desorption in nanofabrication are considered.
Uncommon side effects associated with olanzapine: A case report

Olanzapine (Zyprexa) is one of the novel atypical antipsychotics that act as a serotonin-dopamine receptor antagonist. Its use is increasing in frequency among psychiatrists to treat both the positive and negative symptoms of schizophrenia. It is also becoming a commonly prescribed antipsychotic because of its low association with dystonia and other extrapyramidal side effects. More commonly, sedation, weight gain, and transient, non-dose-dependent, symptomatic elevations in liver enzymes are seen with the use of this drug [1,2,3]. This is a case of a patient who had elevation of transaminases, the appearance of dependent pitting edema of both feet, as well as transient elevations of both systolic and diastolic blood pressures following the administration of olanzapine for psychotic symptoms. This patient was also chronically on albuterol and theophylline for bronchial asthma. There was a complete resolution of edema and normalization of transaminase levels when olanzapine was discontinued.
Surface defect sites facilitate fibrillation: an insight into adsorption of gold-binding peptides on Au(111)

We report new evidence on the surface defect dependent fibrillation of cysteine-free gold-binding peptides (identified from a phage-display peptide library) upon adsorption onto the Au(111) surface revealed using atomic force microscopy (AFM). Dramatic changes in the persistence length and binding conformation of the peptide fibrils on Au(111) have been demonstrated to occur via surface reorganization of the peptide. Moreover, surface defect sites played a governing role in initiating fibrillation. These observations could provide new insight into engineering bio-nano interfaces for self-assembly, biotemplating and biotic-abiotic hybrid material systems and device platforms.
Knowing Their Space: Signs of Jim Crow in the Segregated South

”Jim Crow” was a character portrayed by the black-face minstrel, Thomas “Daddy” Rice, whose stage performances in the 1830s and 1840s typified many whites’ view of African-Americans throughout the nineteenth century. Jim Crow segregationist signs, believed to have been named for this character, are emblematic of southern white leaders’ unrelenting effort to enforce African-American subservience after slavery was outlawed.2 Spread across a vast region of the southern United States, these visual communications systems confirmed the re-marginalization of African Americans in the aftermath of the Civil War and subsequent Reconstruction. Four generations of Southern blacks endured Jim Crow laws; only now, some 50 years after the height of the Civil Rights Movement, are scholars beginning to examine the ubiquitous signage that kept this system of oppression in place.3 Although these Jim Crow signs have
HIV-1 RNA viral load monitoring in HIV-infected drug users on antiretroviral therapy: Relationship with outpatient care patterns

HIV-1 viral load (VL) testing is a standard component of HIV care. We examined the use and predictors of VL testing in drug users, a group at risk for problematic care. Using 1996 to 1998 New York State (NYS) Medicaid files, we studied drug users who had been enrolled >10 months, had been prescribed antiretroviral agents in 1997 and 1998, and who had undergone any VL testing in 1997. Our outcome was regular VL testing shown by two or more paid claims for this test in 1998. Patterns of care in 1997 were defined as: regular source of medical care (>35% of visits to one provider), and/or regular drug treatment of >6 months, or neither. We counted visits in 1997 to a provider offering HIV-focused care. Adjusted odds ratios (AORs) of VL testing were assessed. Of 3131 drug users, 73.9% had at least one VL test, whereas 56.2% had two or more VL tests in 1998. The AORs of two or more VL tests were increased for those with regular drug abuse care alone (AOR, 1.50; 95% confidence interval [CI], 1.21-1.84) or with regular medical care (AOR, 1.27; 95% CI, 1.03-1.57) versus those with neither. HIV-focused care was positively associated with two or more VL tests (AOR, 1.38; 95% CI, 1.05-1.81 for 1-3 visits; AOR, 1.94; 95% CI, 1.50-2.51 for four or more visits). We found that nearly half this cohort of drug users did not have regular VL testing. Drug users with HIV-focused care or with regular drug treatment are more likely to have regular VL testing.
The effect of corroded hydrographic wire on particulate iron concentrations in seawater

Abstract Water collected with 30-1. Niskin bottles on rusty hydrographic wire at three stations contained five times as much particulate iron as water collected with the same samplers on new, aluminized wire. Two samples of particulate matter filtered from the air in a laboratory on the oceanographic R.V. Trident had iron concentrations from 20 to 30 times that in similar samples of uncontaminated marine air. Observations of particulate iron in seawater in which rusty hydrographic wire was used may be affected by contamination. Although samples filtered on board ship may be contaminated by particles in the air, the collection of water samples in metal or even in plastic bottles attached to corroded wire seems the most likely source of the high concentrations of particulate iron that have been reported in the literature.
The effect of ascorbic acid on sodium nitrite-induced methemoglobin formation in glucose-6-phosphate dehydrogenase-deficient erythrocytes

Ascorbic acid significantly reduced the occurrence of sodium nitrite-induced methemoglobin (METHB) formation in a dose-dependent manner in erythrocytes from glucose-6-phosphate dehydrogenase (G-6-PD)-deficient humans in vitro. The ascorbic acid treatment, however, also decreased levels of reduced GSH in a dose-dependent manner, a response indicative of oxidant stress to the erythrocyte membrane. The latter findings are inconsistent with the hypothesis that ascorbic acid supplementation in G-6-PD-deficient humans may help compensate for inherently low levels of erythrocyte GSH. Finally, the ascorbic acid-induced reduction of METHB values, while of statistical significance, does not appear to be of clinical significance.
Duration and outcome in psychotherapy: An integrative review.

Research and practice trends are fueling a vigorous interest in brief therapy, highlighting the question of the relationship between treatment duration and outcome. A number of investigations have reported a weak or nonexistent relation between duration and outcome, yielding the possible conclusion that there are few differences between brief and longer term treatments. A finer-grained analysis, however, based on such methodological factors as the nature, source, and timing of outcome measures, reveals intriguing dose-effect linkages within particular helping modalities. Summarizing process and outcome research, this article identifies potential client, therapist, and contextual mediators of the brevity of treatment.
Clinical diagnosis of rheumatoid arthritis.

Rheumatoid arthritis is a common disease that is now known to progress to irreversible erosive changes in the joints much more quickly than previously recognized. Physicians thus need to identify the early symptoms and signs to make a prompt clinical diagnosis and then start earlier aggressive treatment. Critical features are morning stiffness and symmetrical inflammation involving usually small joints of the hands and feet. Soft tissue swelling is the most important sign of inflammation and begins most often at the metacarpal phalangeal or proximal interphalangeal joints. Joints are tender and warm but often not hot and red. Elevation of erythrocyte sedimentation rate can help confirm the presence of inflammation but the most important laboratory test is synovial fluid analysis which further confirms inflammation but can also help exclude many of the other potentially confusing causes of arthritis. Rheumatoid factor is present in 75% of patients but can also be seen with some other diseases.
On “Gravity anomalies of 2D bodies with variable density contrast” ().

In “Gravity anomalies of 2D bodies with variable density contrast,” Zhang et al. derive a set of equations (9 and 10 in their paper) for a gravity anomaly at the origin of the coordinate system ( x , z ) for a polygon mass body when the density contrast is a polynomial function of x and z . For convenience of discussion, I reproduce and renumber their equations 9 and 10 as, respectively
Effect of Tumor Necrosis Factor–α Inhibitors on Drug-Induced Pancreatitis in Inflammatory Bowel Disease

Background: Mesalamine and thiopurines (6-mercaptopurine and azathioprine) have been shown to increase the risk of developing acute pancreatitis in inflammatory bowel disease (IBD) patients. Tumor necrosis factor-α (TNF-α) inhibitors have been shown to protect against pancreatitis in animal models. Objective: To determine the risk of pancreatitis when comparing thiopurine monotherapy, mesalamine monotherapy, and thiopurine and mesalamine dual therapy to identical treatments but with the addition of a TNF-α inhibitor. Methods: Using a case-control design, the Food and Drug Administration Adverse Event Reporting System was queried for cases of pancreatitis and control reactions in IBD patients on a thiopurine or mesalamine. The proportional reporting ratio method was used to compare the different therapy regimens with the same regimen combined with a TNF-α inhibitor. Results: In all, 549 cases and controls were identified. When comparing thiopurine monotherapy with thiopurines combined with a TNF-α inhibito...
Content‐rich interactive online laboratory systems

Online learning environments are rapidly becoming viable options for offering students a bridge from theoretical concepts to practical engineering applications. They represent collections of integrated tools that provide a delivery mechanism for rich learning content, advanced assessment capabilities as well as affordable access to a wide range of educational resources. Such online learning environments have been used at Stevens Institute of Technology (SIT) for a number of years to provide undergraduate engineering students with a comprehensive laboratory experience based on content-rich and flexible remote and virtual laboratory experiments. These Web-based educational tools were developed using various open source programming languages and free software applications. As discussed in this article, these open source components form a powerful combination for the cost-efficient development, implementation and sharing of Web-based virtual experimentation systems. This article describes the delivery methods for online experiments and the corresponding software modules implemented, which were integrated into a comprehensive student laboratory experience currently being used at SIT in a sophomore-level core undergraduate course on solid mechanics taken by all undergraduate engineering majors as well as in a junior-level course on mechanisms and machine dynamics for mechanical engineering majors. Furthermore, some results of the learning outcomes assessment for online experiments conducted over several years at SIT are summarized. © 2008 Wiley Periodicals, Inc. Comput Appl Eng Educ 17: 61–79, 2009; Published online in Wiley InterScience (www.interscience.wiley.com); DOI 10.1002/cae20210
A cloud-based RDF policy engine for assured information sharing

In this paper, we describe a general-purpose, scalable RDF policy engine. The innovations in our work include seamless support for a diverse set of security policies enforced by a highly available and scalable policy engine designed using a cloud-based platform. Our main goal is to demonstrate how coalition agencies can share information stored in multiple formats, through the enforcement of appropriate policies.
The Kyoto Protocol: Two-Level Bargaining and European Integration

The politics of ratifying the Kyoto Protocol may suggest a two-level game; yet, our quantitative analysis shows that ratification constraints did not affect bargaining over the Protocol, nor did bargaining outcomes affect ratification. The politics of the Kyoto Protocol are best understood as an example of the ‘Europeanization’ of international politics: European countries subordinate their domestic politics to international cooperation, and the European Union emerges as a key agenda setter. We find that European countries ratified the Protocol in lock step and offered selective incentives—such as EU accession—to most of the participants. Case studies of Russia and Poland confirm our interpretation of the empirical findings.
Technical communique: Global practical tracking of a class of nonlinear systems by output feedback

In this paper we address the practical tracking problem for a class of nonlinear systems by dynamic output feedback control. Unlike most of the existing results where the unmeasurable states in the nonlinear vector field can only grow linearly, we allow higher-order growth of unmeasurable states. The proposed controller makes the tracking error arbitrarily small and demonstrates nice properties such as robustness to disturbances and universal property to reference signals.
Bladder Pain Syndrome/Interstitial Cystitis in Twin Sisters

Purpose: We determined the genetic contribution of and associated factors for bladder pain syndrome using an identical twin model.Materials and Methods: Multiple questionnaires were administered to adult identical twin sister pairs. The O'Leary-Sant Interstitial Cystitis Symptom and Problem Index was administered to identify individuals at risk for bladder pain syndrome. Potential associated factors were modeled against the bladder pain syndrome score with the twin pair as a random effect of the factor on the bladder pain syndrome score. Variables that showed a significant relationship with the bladder pain syndrome score were entered into a multivariable model.Results: In this study 246 identical twin sister pairs (total 492) participated with a mean age (± SD) of 40.3 ± 17 years. Of these women 45 (9%) were identified as having a moderate or high risk of bladder pain syndrome (index score greater than 13). There were 5 twin sets (2%) in which both twins met the criteria. Correlation of bladder pain synd...
Immune Cell Modulation of Cardiac Remodeling

Heart failure remains a critical target to improve the health of the US population. It is a major cause of morbidity and mortality in the United States.1 Heart failure is a result of acute or chronic injury followed by healing and remodeling that are insufficient to maintain or restore function. Myocardial infarction (MI) is the major cause of heart dysfunction, but other more chronic injuries, such as those caused by hypertension or genetic defects have many similarities. Article see p 1652 The response to injury in MI can be parsed into multiple overlapping phases (Figure 1). The initial phase involves an acute inflammatory response and includes recruitment of inflammatory cells and the clearance of dead tissue. A subsequent phase involves the initial reparative response replacing the lost tissue and includes immune cells that will both terminate the initial inflammatory response and begin repair.2 This repair is followed by a more prolonged phase of continued remodeling that involves both destruction and replacement of tissue. Remodeling is sensitive to the presence of continued stress, which can have adverse consequences. The innate immune system has recently been shown to be important in cardiac response to MI.2,3 However, a role for adaptive immunity responding to damage has also been suspected with protection from MI in animals treated with adoptive transfer of regulatory T cells.4 Figure 1. Phases of inflammation and healing after myocardial infarction and their alteration in transgenic models. The response to injury can be parsed into 3 phases: injury and inflammation, initial repair, and remodeling. Inflammation has associated proinflammatory leukocytes characterized by Ly-6Chi monocytes or classically activated macrophages (CAM; which would be CD206−). Healing myeloid cells include Ly-6Clo and alternatively activated macrophages (AAM; CD206+). Both monocytes and macrophages are active in the first week. …
From genetics to cellular function using computational biology.

: This article illustrates how computational biology (computer modeling) can be used to link genetic mutations to their cellular phenotypes. Examples are provided from ion channel defects that are associated with hereditary cardiac arrhythmias—that is, the long QT and Brugada syndromes. State-specific Markov models of wild-type and mutant channels are formulated and introduced into a computer model of the ventricular cardiac cell. Simulations are conducted to study the rate-dependent alterations in action potential properties caused by the mutations. Results provide insights into the cellular mechanisms of QT-interval prolongation on the ECG in the long QT syndrome and of ST-segment elevation in the right precordial leads in the Brugada syndrome.
On the (non)universality of the one-time pad

Randomization is vital in cryptography: secret keys should be randomly generated and most cryptographic primitives (e.g., encryption) must be probabilistic. We initiate the quantitative study concerning feasibility of building secure cryptographic primitives using imperfect random sources. Specifically, we concentrate on symmetric-key encryption and message authentication, where the shared secret key comes from an imperfect random source instead of being assumed truly random. In each case, we compare the class of "cryptographic" sources for the task at hand with the classes of "extractable" and "simulatable" sources, where: (1) "cryptographic" refers to sources for which the corresponding symmetric-key primitive can be built; (2) "extractable" refers to a very narrow class of sources from which one can extract nearly perfect randomness; and (3) "simulatable" refers to a very general class of weak random sources which are known to suffice for BPP simulation. For both encryption and authentication, we show that the corresponding cryptographic sources lie strictly in between extractable and simulatable sources, which implies that "cryptographic usage" of randomness is more demanding than the corresponding "algorithmic usage", but still does not require perfect randomness. Interestingly, cryptographic sources for encryption and authentication are also quite different from each other, which suggests that there might not be an elegant way to describe imperfect sources sufficient for "general cryptographic use". We believe that our initial investigation in this new area will inspire a lot of further research.
Stress proteins in aging and life span.

AbstractHeat shock proteins (HSP) are molecular chaperones and have been implicated in longevity and aging in many species. Their major functions include chaperoning misfolded or newly synthesised polypeptides, protecting cells from proteotoxic stress, and processing of immunogenic agents. These proteins are expressed constitutively and can be induced by stresses such as heat, oxidative stress and many more. The induction of HSP in aging could potentially maintain protein homeostasis and longevity by refolding the damaged proteins which accumulate during aging and are toxic to cells. HSP are shown to increase life span in model organisms such as Caenorhabditis elegans and decrease aging-related proteotoxicity. Thus, decrease in HSP in aging is associated with disruption of cellular homeostasis which causes diseases such as cancer, cell senescence and neurodegeneration. HSP levels are decreased with aging in most organs including neurons. Aging also causes attenuation or alteration of many signalling pathw...
The use and transformation of formal decision-making criteria: Sentencing guidelines, organizational contexts, and case processing strategies

Recent sociological research in organizations has emphasized the “filtering” of externally-imposed formal policies and rules through local organizational cultures and strategic interaction processes. This type of generic organizational process assumes special importance for courts and sentencing, subjects of policy-oriented and social problems discourse for over three decades. Eisenstein and associates (1977, 1988; Flemming, Nardulli and Eisenstein 1992) point out that the contexts of local “court communities” and the formal and informal case processing norms of courtroom workgroups are at least as important as formal laws and state-level policies in determining “contours” of criminal justice. Our study focuses on the use and transformation of sentencing guidelines in the interorganizational relations and workgroup case processing strategies in local courts. We draw on the organizational concepts of “embeddedness” (Perrucci 1994) and “properties in use” (Peyrot 1995) of formal decision-making tools to frame our analysis. We present qualitative interview and field data on organizational contexts and case processing strategies from three different-sized county trial courts in Pennsylvania, a state whose courts have operated under sentencing guidelines for over a decade. Among the highlights of the analysis are our findings that DA's offices can use sentencing guidelines as management tools, judges can use them to legitimate their sentencing practices in political disputes, and both prosecutors and defense attorneys use them as important tools of uncertainty reduction in their guilty plea strategies. More generally, we argue that the implimentation of externally imposed formal rules and decision-making criteria depends on local relationships, activities, and informal decision-making criteria.
The Behavioral Hierarchy of the Garden Snail Helix aspersa

It is well documented that animals exhibit “singleness of action” (Sherrington 1906) in their integrated behavior. That is, in the presence of multiple sensory stimuli, animals tend to do one thing at a time. The present study documents such a priority sequence, or behavioral hierarchy, in an herbivorous mollusk, Helix aspersa, and compares this hierarchy with that of the carnivorous marine mollusk Pleurobranchaea (Davis et al. 1974a, b, 1977). Feeding behavior is less dominant in Helix, which as an herbivore relies upon a more abundant and steadily available food supply. Thus the structure of behavioral hierarchies may be related to evolutionary forces consequent upon lifestyle. Zusammenfassung Die gegenseitigen Beeinflussungen von bestimmten Verhaltensweisen wurden quantitativ an der Gehauseschnecke Helix aspersa untersucht, indem jeweils die auslosenden Reize fur zwei verschiedene Verhaltensweisen gleichzeitig geboten wurden. Regelmasig tritt dann eine der beiden Verhaltensweisen unverandert auf, die andere wird unterdruckt. Fressen dominiert immer sowohl uber Aufrichten bei schwacher Beruhrung wie uber geotaktisch orientierte Fortbewegung und Wiederaufrichten nach Umdrehen des Tieres. Zuruckziehen nach einer starken Beruhrung dominiert immer uber Fressen. Diese Unterdruckungen sind einsinnig festgelegt und zeigen eine ahnlich feste Hierarchie der Verhaltensweisen wie fruher schon an der carnivoren Meeresschnecke Pleurobranchaea gefunden. Unterschiede zwischen beiden Schnecken werden mit unterschiedlichen Anpassungen an die herbivore oder carnivore Lebensweise gedeutet.
THE 3D/4D CONTROVERSY AND NON-PRESENT OBJECTS

L'A. propose une nouvelle formulation des positions qui animent la controverse sur l'opposition duree/persistance, ou 3D/4D, dans la metaphysique du temps. Par analogie avec le debat qui oppose le realisme modal a l'actualisme modal, l'A. developpe les notions de non-presentisme et presentisme pour deliberer du statut ontologique des objets non-presents
Screening for vestibular disorders: a study of clinicians' compliance with recommended practices.

Background Dizziness and vertigo are very common patient complaints encountered by clinicians in both primary as well as specialty care in otolaryngology and neurology. Vestibular impairment is an underlying cause in as many as 45% of people complaining of dizziness. Most causes of vestibular impairment can be effectively treated; however, the diagnosis is frequently missed. The aim of this study was to examine clinical assessments used by providers in evaluating dizzy patients in outpatient clinics and the emergency department. Material/methods Computerized medical records of all patients receiving an ICD-9 diagnosis code for dizziness, including benign paroxysmal positional vertigo, Meniere's disease, and vestibular hypofunction over a six-month period at the Atlanta VA Medical Center were reviewed. Results 476 patients were identified and of these, 157 patients were included. Over two-thirds of providers (69%) used the patient's description of the dizziness for identifying the cause; however, significant variability was evident across disciplines, ranging from 84% of audiologists asking for a description of the dizziness to only 33% of geriatricians asking. 89% of providers did not evaluate a patient for BPPV by examining for positional nystagmus. Primary care clinicians referred 22% of dizzy patients to a specialist (neurotologist), geriatricians referred 17%, and emergency physicians referred only 16%. Conclusions Dizzy patients were not routinely screened for vestibular impairment based on available recommended practices, likely contributing to underdiagnosis and treatment. Results indicate a need for effective dissemination of guidelines to improve health care quality, increase awareness of medical risks, and enhance patient access to appropriate treatment.
Germination phenology of some Great Basin native annual forb species

Great Basin native plant communities are being replaced by the annual invasive cheatgrass Bromus tectorum. Cheatgrass exhibits a germination syndrome that is characteristic of facultative winter annuals. Although perennials dominate these communities, native annuals are present at many sites. Germination timing is often an important predictor of competitive interactions, and might determine whether the use of annual species in restoration efforts will be successful. I used a laboratory experiment to determine whether a suite of native annuals exhibit winter or spring annual germination syndromes. Seeds of Amsinckia menziesii var. intermedia, Amsinckia tesselata, Blepharipappus scaber, Descurainia pinnata, Eriastrum sparsiflorum, Lappula occidentalis, Mentzelia veatchiana and Plagiobothrys tenellus were tested for dormancy, and for responsiveness to light, cold stratification and dry after-ripening. Species that would be expected to be most similar to cheatgrass are those that have no requirement for cold stratification and are therefore likely to germinate under autumn or winter conditions. The species that clearly met this criterion in this laboratory study were A. menziesii var. intermedia, A. tesselata, D. pinnata and L. occidentalis. In contrast, B. scaber, E. sparsiflorum, M. veatchiana and P. tenellus had their highest germination after cold stratification and would be expected to be spring germinators. Blepharipappus scaber was not coaxed out of dormancy to a great degree by any of the treatments I applied and may exhibit cue-non-responsive dormancy. Field seed burial experiments, as well as experiments examining the competitive ability of these annuals versus cheatgrass will further inform us about their potential for success in restoration seedings.
Home sample collection tests for HIV infection.

Context.—Home sample collection (HSC) tests allow persons to test themselves for human immunodeficiency virus (HIV) infection at home without medical supervision. Characterizing the use of such tests can help assess their potential effect on public health efforts to prevent and control HIV.Objective.—To describe use of HIV HSC tests.Design.—Retrospective descriptive analysis from data collected by test manufacturers during 1996 and 1997.Setting.—United States.Participants.—Volunteer sample of consumers who used either of 2 HSC tests.Main Outcome Measures.—Demographic and behavioral aspects of users.Results.—During the first year of availability, 174,316 HIV HSC tests were submitted to the manufacturers for analysis; 0.9% of the results were positive for HIV, and 97% of all users called to learn test results. Survey responses from 70,620 HIV-negative and 865 HIV-positive users revealed that most were men, white, and aged 25 to 34 years; HIV prevalence was highest among nonwhites, aged 35 to 44 years, men who have sex with men, and injection drug users. Bisexual men accounted for a large proportion of HIV-positive users. Nearly 60% of all users and 49% of those who tested HIV positive had never been tested before. Telephone counselors found that 23% of HIV-positive users already had a source of follow-up care, 65% accepted referrals, and 12% had tested themselves to evaluate the effects of antiretroviral therapy.Conclusions.—Home sample collection tests for HIV were used by persons who were at risk for HIV and by persons who did not use other testing. Most HIV-positive users either had a source of medical care or received referrals.