cssi/SciSciGPT-SciSciNet huggingface dataset:
Adults Hospitalized With Coronavirus Disease 2019 (COVID-19)-United States, March-June and October-December 2020: Implications for the Potential Effects of COVID-19 Tier-1 Vaccination on Future Hospitalizations and Outcomes.

BACKGROUND: Because of the increased risk for severe coronavirus disease 2019 (COVID-19), the Advisory Committee on Immunization Practices (ACIP) initially prioritized COVID-19 vaccination for persons in long-term care facilities (LTCF), persons aged ≥65 years, and persons aged 16-64 years with high-risk medical conditions when there is limited vaccine supply. We compared characteristics and severe outcomes of hospitalized patients with COVID-19 in the United States between early and later in the pandemic categorized by groups at higher risk of severe COVID-19. METHODS: Observational study of sampled patients aged ≥18 years who tested positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and admitted to one of 14 academic hospitals in the United States during March-June and October-December 2020. Demographic and clinical information were gathered from electronic health record data. RESULTS: Among 647 patients, 91% met ≥1 of the following risk factors for severe COVID-19 [91% March-June (nâ =â 434); 90% October-December (nâ =â 213)]; 19% were LTCF residents, 45% were aged ≥65-years, and 84% had ≥1 high-risk condition. The proportion of patients who resided in a LTCF declined significantly (25% vs 6%) from early to later pandemic periods. Compared with patients at lower risk for severe COVID-19, in-hospital mortality was higher among patients at high risk for severe COVID-19 (20% vs 7%); these differences were consistently observed between March-June and October-December. CONCLUSIONS: Most adults hospitalized with COVID-19 were those recommended to be prioritized for vaccination based on risk for developing severe COVID-19. These findings highlight the continued urgency to vaccinate patients at high risk for severe COVID-19 and monitor vaccination impact on hospitalizations and outcomes.
Crystal structure of the Thr316Ala mutant of a yeast JAMM deubiquitinase: implication of active-site loop dynamics in catalysis

AMSH, an endosome-associated deubiquitinase (DUB) with a high specificity for Lys63-linked polyubiquitin chains, plays an important role in endosomal–lysosomal sorting and down-regulation of cell-surface receptors. AMSH belongs to the JAMM family of DUBs that contain two insertion segments, Ins-1 and Ins-2, in the catalytic domain relative to the JAMM core found in the archaebacterial AfJAMM. Structural analyses of the AMSH homologs human AMSH-LP and fission yeast Sst2 reveal a flap-like structure formed by Ins-2 near the active site that appears to open and close during its catalytic cycle. A conserved phenylalanine residue of the flap interacts with a conserved aspartate residue of the Ins-1 β-turn to form a closed `lid' over the active site in the substrate-bound state. Analyses of these two residues (Phe403 and Asp315) in Sst2 showed that their interaction plays an important role in controlling the flexibility of Ins-2. The Lys63-linked diubiquitin substrate-bound form of Sst2 showed that the conserved phenylalanine also interacts with Thr316 of Ins-1, which is substituted by tyrosine in other AMSH orthologs. Although Thr316 makes no direct interaction with the substrate, its mutation to alanine resulted in a significant loss of activity. In order to understand the contribution of Thr316 to catalysis, the crystal structure of this mutant was determined. In spite of the effect of the mutation on catalytic activity, the structure of the Sst2 Thr316Ala mutant did not reveal significant changes in either the overall structure or the active-site arrangement relative to the wild type. The Phe403–Thr316 van der Waals interaction is impaired by the Thr316Ala mutation, abrogating the adoption of the closed active-site conformation required for catalysis. Since van der Waals interactions with phenylalanine are conserved across substrate-bound forms of AMSH-LP and Sst2, these interactions may be critical for loop immobilization and the positioning of the isopeptide bond of Lys63-linked polyubiquitin-chain substrates.
Dual Neurostimulant Therapy May Optimize Acute Neurorecovery for Severe Traumatic Brain Injuries.

Abstract Background Neurostimulants (NS) can be used to treat patients with a traumatic brain injury (TBI) with altered levels of consciousness. We sought to determine if amantadine alone (monotherapy) versus amantadine + methylphenidate (dual therapy) would correlate with better neurorecovery (NR) among acutely hospitalized patients with a severe TBI. Methods We performed a retrospective review of adult patients admitted to our level I trauma center from 2016-2019 with a severe TBI. NR was calculated by dividing the difference between admission and discharge Glasgow Coma Scale (GCS) scores by 12. Resulting ratios were used to divide the cohort into two groups: excellent NR (1) and non–excellent NR ( Results A total of 76 patients comprised the cohort; 19.7% (n = 15) had excellent NR. The excellent NR group had a larger proportion of patients receiving dual therapy compared to the non–excellent group (86.7% versus 59%, P = 0.04). In monotherapy (n = 27), amantadine was initiated 13 (8-20) d following injury and treatment lasted 7 (2-16) d. In dual therapy (n = 49), amantadine was initiated 12 (6-19) d following injury and continued for 9 (4-25.5) d. Methylphenidate was initiated 15 (7-20.5) d following injury and continued for 5 (2-13.5) d. After adjusting for confounders, dual versus monotherapy predicted excellent NR (OR 5.4, 95% CI 1.2 - 38.9, P = 0.03). Conclusions During the acute hospitalization for a severe TBI, dual NS therapy compared to monotherapy is associated with an increased likelihood of excellent NR. Larger prospective trials are warranted to validate these findings.
PuzzleMe: Leveraging Peer Assessment for In-Class Programming Exercises

Peer assessment, as a form of collaborative learning, can engage students in active learning and improve their learning gains. However, current teaching platforms and programming environments provide little support to integrate peer assessment for in-class programming exercises. We identified challenges in conducting such exercises and adopting peer assessment through formative interviews with instructors of introductory programming courses. To address these challenges, we introduce PuzzleMe, a tool to help Computer Science instructors to conduct engaging in-class programming exercises. PuzzleMe leverages peer assessment to support a collaboration model where students provide timely feedback on their peers' work. We propose two assessment techniques tailored to in-class programming exercises: live peer testing and live peer code review. Live peer testing can improve students' code robustness by allowing them to create and share lightweight tests with peers. Live peer code review can improve code understanding by intelligently grouping students to maximize meaningful code reviews. A two-week deployment study revealed that PuzzleMe encourages students to write useful test cases, identify code problems, correct misunderstandings, and learn a diverse set of problem-solving approaches from peers.
Transient solution of 3D free surface flows using large time steps

The solution of three-dimensional unsteady Newtonian flows with free surfaces is considered.An Arbitrary Lagrangian Eulerian (ALE) formulation is derived from the Reynolds transport theorem.A 'flow condition based interpolation' (FCBI) scheme for a tetrahedral element is used.The proposed method conserves mass accurately and obtains stable and accurate results with large time steps.Various example solutions are given to show the effectiveness of the solution schemes. This paper presents an Arbitrary Lagrangian Eulerian (ALE) formulation derived from the Reynolds transport theorem to accurately solve certain problems of three-dimensional unsteady Newtonian flows with free surfaces. The analysis problems addressed are those without breaking waves or waves spilling over obstructions. The proposed method conserves mass very accurately and obtains stable and accurate results with large time steps, and even when using rather coarse meshes. The continuum mechanics equations are formulated and the three-dimensional Navier-Stokes equations are solved using a 'flow condition based interpolation' (FCBI) scheme for a tetrahedral finite element using finite volume concepts. Various example solutions are given to indicate the effectiveness of the solution schemes.
The Human CD34 Hematopoietic Stem Cell Antigen Promoter and a 3′ Enhancer Direct Hematopoietic Expression in Tissue Culture

The human CD34 hematopoietic stem cell antigen is a highly glycosylated type 1 membrane protein of unknown function. CD34 is expressed on 1% to 4% of bone marrow cells, including pluripotent stem cells and committed progenitors of each hematopoietic lineage. CD34 has also been shown to be expressed on the small vessel endothelium of a variety of tissues and on a subset of bone marrow stromal cells. We have chosen to use the human CD34 gene as model to examine the transcription factors and cis-elements required for stem cell/progenitor cell-specific gene regulation. We show here that the CD34 gene is transcriptionally regulated in tissue culture cells. Using a luciferase reporter gene, we have isolated and characterized an active CD34 promoter. A CD34-luciferase construct, containing 4.5 kb of 5' flanking DNA from a CD34 genomic clone, was 30-fold more active in CD34+ tissue culture cells than in HeLa cells. Sequences from the 3' end of the CD34 gene were shown to have enhancing activity in CD34+ T-lymphoblastic RPMI-8402 cells and not in CD34- U937 cells or in nonhematopoietic HeLa cells. We also show that a cytidine-guanosine island in the 5' end of the CD34 gene is heavily methylated in two CD34- hematopoietic cell lines and demethylated in two CD34+ cell lines. Analysis of the CD34 promoter should result in the identification of stem cell/progenitor cell-specific transcription factors and should provide a means to direct the expression of heterologous genes in hematopoietic stem cells and progenitors.
The Effects of Tire Inflation Pressure on Passenger Car Fuel Consumption

Measurements of passenger car fuel consumption at different tire inflation pressures were recently conducted. These measurements were obtained from a vehicle operated on a test track using transient driving cycles and over a range of ambient conditions. The observed changes in fuel consumption, 0.33 percent/psi, should therefore be representative of actual driving conditions. Subsequently, tire inflation data from 2000 vehicles in six cites were analyzed to determine the extent of passenger car tire underinflation. These data sources were then combined to estimate the nationwide excess fuel consumption, about 600 million gallons per year, due to tire underinflation.
Simulation of switched-current systems

Recent technological advances have made switched current (SI) circuit technologies a viable means for implementing analog signal processing circuits. The development of accurate modeling and verification procedures is important. Simulation and modeling issues in SI circuits are explored. These procedures are successfully implemented in the new SI simulation tool, the extracted data simulator (EDSIM). >
Emerging Market Real Estate Investment: Investing in China, India, and Brazil by David J. Lynn, with Tim Wang

In the aftermath of the recent financial crisis, books focusing on the probable causes of the crisis quickly replaced those concerned with explaining the benefits or pitfalls of globalization at th...
I Have Seen the Future! Ethics, Progress, and the Grand Challenges for Engineering

This article is a critique of the U.S. National Academy of Engineering’s report, Grand Challenges for Engineering , based upon the “technocratic view” of progress as defined by historian Leo Marx and as exemplified by the public works of Robert Moses, including the 1964 World’s Fair, as well as technological determinist narratives on the digital age drawn from contemporary culture. While the so-called Grand Challenges purport to have social aims, a close reading of the document’s overview essay suggests that the technocratic view of progress—which views technology primarily as an end in itself rather than as a means to social progress and fails to explicitly account for engineers’ social and ethical responsibilities—still dominates the thinking of at least some leaders of the engineering profession. This technocratic thinking presents a critical barrier to achieving social justice both within engineering and in the larger world.
Conversation about Software Requirements with Prototypes and Scenarios

Determining the functional requirements for new software is a significant problem because it is dependent upon effective conversation between software designers and users. Prototypes and scenarios are two key techniques that have been advocated to improve the specification and communication of software requirements. This paper describes experimental research examining the utilization of prototypes and scenarios during designer-user conversation to determine and validate software requirements. This study is among the first to empirically test the effectiveness of employing scenarios in requirements determination. The results indicate that scenarios can affect user feedback in conversation about software requirements. The results also suggest that software designers should present users with a combination of software prototypes alongside abstract, diagrammatic models when discussing software requirements.
Patterns of reinvention: The nature of evolution during policy diffusion

This study considers how states change policy innovations as they diffuse. This process of policy evolution during diffusion, known as reinvention, has been the focus of recent work on innovation diffusion in the states (Clark, 1985; Glick, 1992; Glick & Hays, 1991; Mooney & Lee, 1995). This manuscript focuses on differences in the patterns of reinvention for three different policy innovations with different rates of diffusion: child abuse reporting laws, crime victim compensation laws, and public campaign funding laws. Moreover, how the pattern changes after states amend their initial laws is examined. The data show evidence of reinvention during diffusion but provide only limited support for the first hypothesis that the pattern of reinvention is one of increasing comprehensiveness over time. Consistent with expectations, the data reveal little relationship between the date of adoption and the current law's comprehensiveness, including amendment.
Mandated reporting of suspected child abuse : ethics, law & policy

Mandated Child Abuse Reporting Laws - Origins and Evolution Mandated Reporting as an Ethical Dilemma When Professional Hunches Become Reasonable Suspicions Therapeutic Jurisprudence and Mandated Reporting Unreported Cases of Suspected Child Abuse Reported Cases of Suspected Child Abuse Guidelines for Reporting Suspected Child Abuse Professional Practice and Research Child Protection Policy.
How the ratio of meridional flux of fresh‐water to flux of heat fixes the latitude where low salinity intermediate water sinks

Prescription of the meridional fluxes of fresh-water and heat fixes lower limits on the magnitude of meridional volume fluxes, the direction and relative depths at which they occur, and the latitude at which low salinity intermediate water converges and sinks. It also reveals that the main transport occurs in two separate meridional cells with opposing sense of rotation, and determines the latitude of the boundary between them.
Note on the Symposium on the Use of Models in Geophysical Fluid Dynamics

A symposium was held September 1-4, 1953 at The Johns Hopkins University, Baltimore, Maryland to discuss the problems and potentialities of models in investigations of geophysical phenomena. About zs research workers in the fields of oceanography, meteorology, aeronautics, geo-magnetism, civil engineering, and applied mathematics attended the conference. Fifteen papers were presented followed by discussions. DOI: 10.1111/j.2153-3490.1954.tb01098.x
A Technique for Studying Sperm Maturation in vitro

IN mammals spermatozoa mature while passing through the epididymis. In the rabbit there are virtually no fertile spermatozoa in the caput epididymidis and fertilizing ability is acquired when, the spermatozoa pass through the corpus epididymidis1,2. Spermatozoa retained by ligatures, in the proximal corpus develop a normal fertilizing ability in 24 h, but never become fertile when retained for 1 to 12 days in the proximal caput epididymidis3,4. These results strongly suggest that the factors governing the maturation process are not intrinsic to the spermatozoa. To determine whether the development of the fertilizing ability can be achieved similarly when the proximal corpus is maintained 24 h in vitro in organ culture, we used the technique described below. Testes were reached aseptically by means of an abdominal incision, and connective tissue and fat were gently peeled from the epididymis of the anaesthetized animal. The tissue was then removed; the proximal corpus and distal corpus were separated and each placed in 1 ml. of a solution of 0.05% pronase or of 0.5% clostridium peptidase for 30 to 60 min at 31° C. The epididymal tubule was gently unconvoluted and placed unbroken on an agar strip. Trowell's5 organ culture technique was used with Steinberger's6 modification. The medium was Eagle's7 minimal medium with 15% foetal calf serum and 100 I.U. penicillin-streptomycin mixture. The gas phase was air containing 5% CO2, and the cultures were incubated at 31° C, pH 7.0±0.2. A 2 mm segment from the epididymis just distal to the distal corpus was cut up in 0.5 ml. of the same tissue culture medium. The sperm suspension was incubated in a test-tube for 24 h under the same conditions. After 24 h the epididymal tubule placed in organ culture was removed, cut up in 1 ml. Hank's solution and the debris removed. The two sperm suspensions were injected through both uterine walls of one or two does, which were injected with an ovulatory dose of 50 I.U. of human chorionic gonadotrophin (HCG) at the time of insemination. Females were killed 26 h after injection of HCG. The oviducts were flushed and the eggs recovered were examined for the presence of pronuclei or of cleavage, taken as evidence of fertilization. Nuclear details were clarified with acetocarmine staining after fixation in 1:3 acetic alcohol8. The male was then killed, the contralateral testis and epididymis removed and the proximal corpus and distal corpus were separated, cut up in 0.5 ml Hank's solution and the debris removed. Sperm suspensions were inseminated in 1 or 2 does as described above. A total of 13 males and 58 females were used.
Mars secular obliquity change due to water ice caps

Mars may have substantially changed its average axial tilt over geologic time due to the waxing and waning of water ice caps. Depending upon Mars' climate and internal structure, the average obliquity could have increased or decreased through climate friction by tens of degrees. A decrease could account for the apparent youthfulness of the polar layered terrain. Alternatively, Mars' average obliquity may have changed until it became "stuck" at its present value of 24.4 deg.
Determination of methyl radical concentrations in a methane/air flame by infrared cavity ringdown laser absorption spectroscopy

Infrared cavity ringdown laser absorption spectroscopy (IR-CRLAS) is employed to determine absolute methyl radical concentrations in a 37.5 Torr laminar methane/air flame. IR-CRLAS rovibrational absorption spectra of the ν3 fundamental band system near 3200 cm−1 are combined with N2-CARS temperature measurements to obtain methyl radical concentrations as a function of height above the burner surface. These data are compared with flame chemistry simulations under both stoichiometric and rich flame conditions. Issues regarding the applicability of IR-CRLAS for combustion studies are discussed, including the uncertainties present for the specific case of methyl radical. These IR-CRLAS measurements indicate the ability to monitor reactants, intermediates, and products within a narrow spectral window, and, to our knowledge, constitute the first infrared detection of a polyatomic radical in a flame.
Effective-modulus approximation for surface-vibration modes

The effective-mass approximation enables one to obtain the energies and wave functions of impurity levels, in a slowly varying perturbing potential, associated with extrema in the electronic band structure of the unperturbed crystal. We have developed an analogous method for obtaining the dispersion relation and displacement field of acoustical or optical surface vibration modes associated with extremal points in the surfaces of constant frequency of the corresponding, infinitely extended crystal. By factoring out the rapidly varying part of the displacement field corresponding to each of the normal modes associated with such an extremal point, a set of partial difference equations is obtained for the slowly varying amplitudes. These equations are converted into a set of coupled partial differential equations which explicitly incorporate the stress-free boundary conditions at the crystal surface. The solution of these equations yields the surface-mode dispersion relation and displacement field. The method is illustrated by applying it to one- and three-dimensional semi-infinite models.
Laser Process Effects on Physical Texture and Wetting in Implantable Ti-Alloys

Wetting is an important aspect for implantable biomaterials, as it affects the initial interaction with physiological fluids, which in turn dictates the protein adsorption, cell attachment, and tissue integration at the interface. In light of this in the present overview, surface engineering techniques based on laser processing of implantable titanium alloys for improved wettability and cell compatibility is discussed. Here three different laser processing techniques, laser interference patterning, continuous wave laser direct melting, and pulsed laser direct melting and the influence of each type of processing on the micro-texture evolution are studied Finally, the effect of micro-textures on the wettability and thereby its in vitro bioactivity and in vitro biocompatibility is systematically discussed.
Two perspectives on consensus for (Bayesian) inference and decisions

Questions of consensus among Bayesian investigators are discussed with regard to: (1) inference and (2) decisions. Concerning topic (1), results about asymptotic consensus and certainty with increasing evidence are reported. The findings deal with extending a conclusion of D. Blackwell and L. Dubins (1962) from pairs of agents to larger communities. Increasing evidence creates (almost sure) certainty of the truth and, depending upon the size of the community, it leads to varieties of consensus for conditional (posterior) distributions. Concerning topic (2), results are reported on the shared agreements of two Bayesian decision makers who have some differences in their probabilities for events and some differences in their utilities for outcomes. The results are couched in a setting where acts are so-called horse lotteries, with coherence defined by axiomatic restrictions on preferences over such acts. Subject to a weak Pareto condition, it is established that the only coherent preference schemes are the two agents' preferences themselves. Moreover, stronger Pareto conditions exclude even these extreme solutions. >
Sulfur 2p ionization energies of H2S, OCS, SO2, and CS2

Abstract The 2p 1 2 and 2p 3 2 ionization energies of H2S, OCS, SO2, CS2, and Ar have been measured and are compared with existing values in the literature.
Evoked Potentials and Auditory Reaction Time in Monkeys

Monkeys with bipolar stimulating and recording electrodes in primary auditory cortex were trained to release a key to the onset of a pure tone. Substitution of direct cortical stimulation for the pure tone resulted in a reduction of 15 milliseconds In the latency of the behavioral response. This changed latency agreed with the latency of the primary evoked potential recorded from the animals. Systematic related changes in the amplitude of the central response and in the latency of the behavioral response followed changes in the intensity and frequency of the acoustic stimulus.
Effects of cobalt (III) complexes on growth and metabolism of Escherichia coli

Abstract Inhibition of cell division of E. coli—with the production of elongated cells—was accomplished by incorporating various cobalt(III) complexes, such as chloropentaamminecobalt(III) chloride or nitropentaamminecobalt(III) chloride in a defined growth medium. Studies of cell metabolism and growth rates were undertaken in an attempt to elucidate this phenomenon. Treated cells exhibited stimulated oxygen uptake, but the growth, as reflected by light scattering at 540 nm, was slightly repressed. The results of C-14 glucose tracer studies indicate an enhanced turnover of substrate but do not reflect major shifts in cell biochemistry. Tritiated precursors were used to examine the influence of these compounds on nucleic acid synthesis, and a depression in the incorporation of thymidine-methyl-H-3 into DNA was noted. In contrast to the behavior of the active cobalt (III) complexes, typical cobalt(II) salts, such as cobaltous sulfate, caused complete inhibition of biological activity.
Rates and Success Rates of Trial of Labor After Cesarean Delivery in the United States, 1990–2009

This study compares rates of trial of labor after Cesarean delivery (TOLAC) and rates of successful TOLAC between 1990 and 2009. Serial cross-sectional analyses were performed using the National Hospital Discharge Survey data to compare rates of TOLAC and TOLAC success between 1990 and 2009. Joinpoint regression was used to assess trends over time, and logistic regression with marginal effects was used to examine the unadjusted and adjusted significance and magnitude of trends. The rate of TOLAC reached a high of 51.8 % (95 % CI 47.8–55.8 %) in 1995 and a low of 15.9 % (95 % CI 13.8–18.0 %) in 2006, declined, on average, 4.2 (95 % CI −4.8 to −3.9) percentage points per year between 1996 and 2005. Rates increased significantly from 1990 to 1996 and 2005 to 2009. TOLAC success was at its highest rate in 2000, 69.8 % (95 % CI 65.2–74.3 %) and its lowest in 2008, 38.5 % (95 % CI 28.1–48.8 %). The rate of TOLAC success increased significantly between 1990 and 2000, but declined thereafter an average of 3.4 % points per year (95 % CI −4.3 to −2.5). The rate of TOLAC in the US decreased between 1996 and 2005 and the rate of successful TOLAC has declined from 2000 to 2009.
Mucocutaneous manifestations of HIV infection.

Abstract The acquired immunodeficiency syndrome (AIDS) has been associated with mucocutaneous eruptions since it was first described with Kaposi's sarcoma as a diagnostic criterion. 1 Human immunodeficiency virus (HIV), the etiologic agent of AIDS, is associated with a wide spectrum of clinical disorders. These conditions range from asymptomatic infection to AIDS-related complex or AIDS. 2 Mucocutaneous eruptions associated with HIV infection are common and frequently occur before the development of AIDS. 3–5 Although cutaneous manifestations are not the direct result of HIV infection, the majority of these eruptions are associated with immunosuppression. The common denominator of the immunosuppressed state resulting from infection with HIV is the infection and destruction of the helper/inducer subset of T-lymphocytes that express the CD4 receptor. 6 As immune function progressively deteriorates, opportunistic infections and malignancies evade immune surveillance resulting in clinical disease. Eruptions occurring in atypical distributions or in severe or chronic forms should alert the physician to the possibility of underlying HIV infection. In many instances, these eruptions are very difficult to manage and are frequently resistant to standard medical therapy. The mucocutaneous manifestations associated with HIV infection can be divided into three categories: (1) infections, (2) neoplasms, and (3) miscellaneous (Table 7-1).
Multiscale aggregating discontinuities method for micro–macro failure of composites

The application of a multiscale method, called the multiscale aggregating discontinuities (MAD) method, to the failure analysis of composites is described. Two distinct features of the MAD method are the use of perforated unit cells, and the extraction of coarse-grained failure information. In the perforated unit cell, all subdomains of the unit cell that are not strictly elliptic are excluded, which enables the decomposition of its stable and unstable material. By means of these concepts, it is possible to compute an equivalent discontinuity at the macroscale, including both the direction and the magnitude of the discontinuity. This equivalent discontinuity is then passed to the macroscale along with the computed stress from the unit cell. The macroscale discontinuity is injected into the macro model by the extended finite element method (XFEM) procedure. In this paper, the method is improved by adding hourglass modes to the unit cell deformations, which better model growing cracks. Several examples comparing the MAD method with direct numerical simulations are presented.
Green nanocomposites from cellulose acetate bioplastic and clay: Effect of eco-friendly triethyl citrate plasticizer

“Green” nanocomposites have been successfully fabricated from cellulose acetate (CA) powder, eco-friendly triethyl citrate (TEC) plasticizer and organically modified clay. The effect of the amount of plasticizer varying from 15 to 40 wt % on the performance of the nanocomposites has been evaluated. The morphologies of these nanocomposites were evaluated through X-ray diffraction (XRD), atomic force microscopy (AFM), and transmission electron microscopy (TEM) studies. The mechanical properties of nanocomposites are correlated with the XRD and TEM observations. Cellulosic plastic-based nanocomposites with 20 wt % TEC plasticizer and 5 wt % organoclay showed better intercalation and an exfoliated structure than the counterpart having 30/40 wt % plasticizers. The tensile strength, modulus and thermal stability of cellulosic plastic reinforced with organoclay showed a decreasing trend with an increase of plasticizer content from 20 to 40 wt %. The nano-reinforcement at the lower volume fractions (φ ≤ 0.02) red...
Democratic consolidation and failure: Lessons from Bangladesh and Pakistan

The long transitions from military rule in Pakistan (1977–88) and Bangladesh (1975–90) have been almost completely ignored in studies of democratization. They deserve more attention, partly because, from the methodological point of view, the many similarities between them help us to isolate the most important factors that lead to successful transitions and democratic consolidation. The contrast between Bangladesh, which successfully consolidated its democracy in the 1990s, and Pakistan, which did not, demonsrates the general importance of three factors. First, it lends support to Alfred Stepan's argument in Rethinking Military Politics: Brazil and the Southern Cone (1988), that cases where the ‘military as institution’ is threatened by continuing in power ‐ as in Bangladesh ‐ will be more likely to make a successful transition. Second, the contrast between Bangladesh and Pakistan brings out the critical importance of an autonomous civil society ‐ which exists in Bangladesh but not Pakistan ‐ during a tran...
The far infrared spectrum of methyl mercaptan from 15 cm−1 to 45 cm−1

Abstract The infrared absorption spectrum of methyl mercaptan is measured between 17 cm −1 and 44 cm −1 . Theoretical analysis shows that the absorption spectrum in this range is associated with end-over-end rotation (parallel transitions) of the molecule as well as with internal rotation transitions (perpendicular transitions). Calculating both of these contributions to the absorptions, the infrared spectrum is identified. A value is deduced for the rotational constant and for the centrifugal stretching constant. Internal rotation energy levels and wave functions for methyl mercaptan are tabulated.
Diet and acne

Acne is a common dermatologic condition that affects many individuals in different decades of life. The specifi c role of diet in the development of acne has been a topic of debate for many decades, but this controversy has come to the forefront in recent years with new studies indicating the potential role of diet, contradicting historical studies. This article reviews past and more recent data regarding the link between diet and acne, commenting on areas where new investigations many help to elucidate the true contribution of diet to the pathogenesis of acne.
Chemisorption of hydrogen sulfide on nickel and ruthenium catalysts: I. Desorption isotherms

Abstract Desorption isotherms for H2S on unsupported nickel and alumina-supported nickel, nickel-platinum, nickel-cobalt, and ruthenium were calculated from elution curves of H2S from a packed bed of each catalyst. All elution experiments were run initially at 450 °C and at H2S concentrations in the exiting hydrogen stream from 30 to 0.1 ppm. Elution curves and isotherms for supported nickel-platinum were also obtained at 450 and 520 °C from which an estimate of the heat of H2S chemisorption was calculated. The heat of H2S adsorption on nickel is estimated to be 30–40 kcal/mole at 450 °C and high coverage (50–90%). The stoichiometry of sulfur adsorption was determined by comparing the total quantity of sulfur adsorbed at 450 °C with the corresponding quantity of hydrogen chemisorbed at 25 °C for each catalyst. The data suggest that H2S chemisorption is strong and dissociative at low coverage and nondissociative at high coverages. Ruthenium apparently has a lower capacity for sulfur adsorption than nickel or nickel alloys.
Second-order pion-nucleus optical potential

The second-order pion-nucleus optical potential is expressed in momentum space in terms of the $\ensuremath{\pi}N$ off-shell $t$ matrix and the $\mathrm{NN}$ correlation function. The dependence of the $\ensuremath{\pi}N t$ matrix on the total $\ensuremath{\pi}N$ momentum is determined within the framework of relativistic particle quantum mechanics. Numerical results are presented for $\ensuremath{\pi}\ensuremath{-}^{4}\mathrm{He}$ scattering. It is found that the $\mathrm{NN}$ correlations tend to decrease the forward elastic cross sections by a factor of about 1.5 at low energy, ${E}_{\ensuremath{\pi}}\ensuremath{\simeq}60$ MeV. At higher energies the main effect of the $\mathrm{NN}$ correlations is to increase the differential cross section at large angles. The effect of $\mathrm{NN}$ correlations on the total cross section and the pion wave function is also found to be important. A study of the dependence of the calculated cross sections on the range parameters of the $\ensuremath{\pi}N t$ matrix and of the $\mathrm{NN}$ correlations suggests that the $\mathrm{low}$-energy pion-nucleus scattering data cannot be adequately described by an optical model constructed from the first- and second-order terms in an expansion in terms of the $\ensuremath{\pi}N t$ matrix.[NUCLEAR REACTIONS Second-order $\ensuremath{\pi}$-nucleus optical potential studied in the multiple-scattering theory.]
Neural Network Strategy for Sampling of Particle Filters on the Tracking Problem

Sequential Monte Carlo methods, namely particle filters, are popular statistic techniques for sampling sequentially from a complex probability distribution. Sampling is a key step for particle filters and has vital effects on simulation results. Since degeneracy of particles in samples sometimes is very severe, there exist only a few particles with significant weights. Thus the sample diversity is reduced significantly so that only a few particles are used to represent the corresponding probability distribution. Therefore, resampling has to be used very often during the whole procedure. This paper addresses a new method which can avoid the phenomenon of particle degeneracy. A backpropagation neural network is used to adjust low weight particles in order to increase their weights and particles with high weights may be split into two small ones if needed. Our simulation results on a typical tracking problem show that not only the phenomenon of particle degeneracy is effectively avoided but also tracking results are much better than those of the traditional particle filter.
Circulation and distribution of oceanographic properties near the Filchner Ice Shelf

Abstract During February, 1973, a hydrographic survey of the continental shelf zone adjacent to the Filchner Ice Shelf in Antartica was carried out by the Scripps Institution of Oceanography aboard the USCGC Glacier . The distributions of temperature and salinity indicate a cyclonic circulation of the subsurface water masses. From its source beneath the Filchner Ice Shelf, Ice Shelf Water, characterized by temperatures below the freezing point at 1 atm pressure, flows northward along the western bank of the Filchner Depression. At about 75°S, the Ice Shelf Water overrides the high salinity Western Shelf Water derived from the broad continental shelf in the southwestern Weddell Sea. Subsequently, both water masses move in a cyclonic direction following the contours of the depression.
Some Information Theoretic Optimality Criteria for General Classification

Central to the various purposes for which general classification is practiced is the preservation, or summarizing, of information (Michener, 1963; Sneath, 1957; Sokal, 1962; Farris, 1967; Johnson, 1968; Rogers, 1961; Wirth, Estabrook, and Rogers, 1966). This discussion will present one method in which this fundamental concept can be made more precise and, within that context, suggest possible logical formulations for preservation or summarization of information.
Variational functional for transition amplitudes: Improving the time-dependent Hartree-Fock method.

A variational expression is introduced for transition amplitudes, that is invariant under time reversal and is independent of the phases of trial states. With the use of time-dependent Hartree-Fock (TDHF) wave functions and a linear combination of atomic orbitals, exact numerical results for He+He/sup 2 +/..-->..He/sup +/+He/sup +/ obtained within a small basis set, are compared with results from the variational functional. The variational procedure leads to a very substantial improvement over the standard TDHF results.
Combined Effects of Surfactant Substitution and Prolongation of Inspiration Phase in Artificially Ventilated Premature Newborn Rabbits

Premature newborn rabbits, delivered by hysterotomy on day 27 of gestation, were tracheotomized at birth, kept in body plethysmographs, and subjected to pressure-generated ventilation at a working pressure of 25 cm H2O, 100% O2, and frequency 40/min. Thirty-seven animals received 50 microliters of heterologous surfactant (phospholipid content 40 mg/ml) via the tracheal cannula before onset of artificial ventilation, eight were ventilated with a positive end-expiratory pressure (PEEP) of 6 cm H2O, and 44 served as controls. All animals were ventilated in a randomized sequence of 2-min periods with 20, 40, 60, or 80% inspiration time. After the experiment the trachea was clamped at end-inspiration and the lungs fixed by immersion in formalin. Plethysmograph recordings of tidal volume revealed that lung-thorax compliance was low in control animals, even at inspiration time 80% (mean +/- S.E. = 0.17 +/- 0.03 ml/cm H2O X kg). In animals treated with surfactant or PEEP, compliance was significantly improved at all ventilator settings. The highest mean compliance values, obtained at 60% inspiration time were 0.91 +/- 0.07 and 0.73 +/- 0.14 ml/cm H2O X kg in surfactant- and PEEP-treated animals, respectively. Compliance of surfactant-treated animals was significantly higher than that of PEEP-treated animals at inspiration time 40% (0.85 +/- 0.07 versus 0.52 +/- 0.13 ml/cm H2O X kg; P less than 0.05). The relative volume of the alveolar compartment, determined morphometrically in histologic sections and expressed as the alveolar expansion index (Ia), was significantly higher in surfactant-treated animals than in controls (1.60 +/- 0.12 versus 0.74 +/- 0.06; P less than 0.005), but not improved in animals ventilated with PEEP. In animals receiving surfactant, Ia increased with the duration of the inspiration phase, from 0.99 +/- 0.10 at 20% to 1.95 +/- 0.22 at 80% inspiration time. There was also histologic evidence of enhanced recruitment of aerated alveoli in surfactant-treated animals ventilated with prolonged inspiration time.
Oxygen Cost of Electrical Activation of the Heart

The present study was undertaken to define the O2 requirements of electrical activation of the heart. Thirteen isolated canine hearts were perfused with whole blood from which calcium had been removed with an exchange resin and to which the disodium salt of ethylenediaminetetraacetic acid had been added. Spontaneous depolarizations were suppressed by raising the plasma potassium to an average concentration of 7.5 mEq/liter, and the right ventricle was stimulated electrically at controlled frequencies. Although the stimuli produced propagated depolarizations, neither high-sensitivity strain gauge arches sutured to both ventricles, nor careful visual observation, showed any evidence of associated contractile activity. Ten of the hearts were studied with repetitive single stimuli applied in the conventional fashion, while the remaining three hearts were subjected to paired electrical stimulation. Changes of myocardial O2 consumption (MV·O2) were measured at a constant coronary blood flow and arterial O2 content by determining changes of venous O2 content from a continuous recording of venous PO2. Increases of the frequency of depolarization were uniformly accompanied by small increases of MV·O2, averaging 0.40 ± 0.04 (SEM) µliter/activation/100 g. The increases were of the same order of magnitude in the hearts subjected to paired electrical stimulation as in the hearts studied with single stimulation, suggesting that the altered frequency and rhythm of depolarization in paired electrical stimulation cannot account for the marked increase of MV·O2 which this intervention produces in the intact heart. It is concluded that the amount of O2 required for electrical activation of the heart is less than 1% of the total O2 consumption of the normally working heart.
Xenon-enhanced CT imaging of local pulmonary ventilation

We are using the unique features of electron beam CT (EBCT) in conjunction with respiratory and cardiac gating to explore the use of non-radioactive xenon gas as a pulmonary ventilation contrast agent. The goal is to construct accurate and quantitative high-resolution maps of local pulmonary ventilation in humans. We are evaluating xenon-enhanced computed tomography in the pig model with dynamic tracer washout/dilution and single breath inhalation imaging protocols. Scanning is done via an EBCT scanner which offers 50 msec scan aperture speeds. CT attenuation coefficients (image gray scale value) show a linear increase with xenon concentration (r equals 0.99). We measure a 1.55 Hounsfield Unit (HU) enhancement (kV equals 130, mA equals 623) per percentage increase in xenon gas concentration giving an approximately 155 HU enhancement with 100% xenon gas concentration as measured in a plexiglass super-syringe. Early results indicate that a single breath (from functional residual capacity to total lung capacity) of 100% xenon gas provides an average 32 +/- 1.85 (SE) HU enhancement in the lung parenchyma (maximum 50 HU) and should not encounter unwanted xenon side effects. However, changes in lung density occurring during even short breath holds (as short as 10 seconds) may limit using a single breath technique to synchronous volumetric scanning, currently possible only with EBCT. Preliminary results indicate close agreement between measured regional xenon concentration-time curves and theoretical predictions for the same sample. More than 10 breaths with inspirations to as high as 25 cmH2O airway pressure were needed to clear tracer from all lung regions and some regions had nearly linear rather than mono-exponential clearance curves. When regional parenchymal xenon concentration-time curves were analyzed, vertical gradients in ventilation and redistribution of ventilation at higher inspiratory flow rates were consistent with known pulmonary physiology. We present here a works in progress, showing results from two pigs illustrating the high resolution and detailed regional information obtainable with careful attention to cardiac and respiratory gating during a multi-breath washout period.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Minority Stress Theory: An Examination of Factors Surrounding Sexual Risk Behavior Among Gay and Bisexual Men Who Use Club Drugs

Background: Few studies have examined the impact of minority stress theory (MST) upon sexual risk behavior among gay and bisexual men using club drugs. Similar studies have focused on ethnic minorities and women; however, gay and bisexual men demonstrate greater likelihood for risk behaviors leading to HIV/AIDS. Objective: This study examines sexual risk behavior from the perspective of minority stress theory upon substance-using gay and bisexual men and their partners. Methods: Multivariable logistic regression analysis examined minority stress associations with participant sexual risk behaviors, drug use, and partner type, controlling for demographics. Results: 396 gay and 54 bisexual respondents, ages 18–67, reported at least one-time drug use while engaging in sexual risk behavior. In the adjusted model, expectations of rejection associated with lower odds of sexual risk behavior, while older age approached significance. Conclusions: Theoretical origins for examining risk behavior among gay and bisexu...
Comparison of M-Side Electron Transfer in Rb. sphaeroides and Rb. capsulatus Reaction Centers

Subpicosecond time-resolved absorption and steady-state resonance Raman studies are reported for Rhodobacter sphaeroides reaction centers (RCs) that incorporate the G(M203)D/L(M214)H double mutatio...
Water-wire catalysis in photoinduced acid–base reactions

The pronounced ability of water to form a hyperdense hydrogen (H)-bond network among itself is at the heart of its exceptional properties. Due to the unique H-bonding capability and amphoteric nature, water is not only a passive medium, but also behaves as an active participant in many chemical and biological reactions. Here, we reveal the catalytic role of a short water wire, composed of two (or three) water molecules, in model aqueous acid–base reactions synthesizing 7-hydroxyquinoline derivatives. Utilizing femtosecond-resolved fluorescence spectroscopy, we tracked the trajectories of excited-state proton transfer and discovered that proton hopping along the water wire accomplishes the reaction more efficiently compared to the transfer occurring with bulk water clusters. Our finding suggests that the directionality of the proton movements along the charge-gradient H-bond network may be a key element for long-distance proton translocation in biological systems, as the H-bond networks wiring acidic and basic sites distal to each other can provide a shortcut for a proton in searching a global minimum on a complex energy landscape to its destination.