cssi/SciSciGPT-SciSciNet huggingface dataset:
The Extension of Crack Tip Damage Zones in Fiber Reinforced Plastic Laminates

The size and character of the damage zone at the tip of sharp notches in fiber reinforced plastic laminates have been investigated. The variables studied were the stress intensity factor, specimen size, laminate thickness, ply thickness, ply orientation, and fiber properties. The damage zone consists of subcracks parallel to the fibers of each ply, in some cases accompanied by delamination between plies. The damage zone is found to increase in extent approximately in proportion to K2I up to fracture for notch-sensitive laminates. For notch-insensitive laminates, a point is reached where the zone spreads rapidly across the entire specimen prior to fracture. A strong dependence of damage zone size and fracture toughness on ply thickness, fiber orientation, and fiber properties is demonstrated and discussed.
How Teachers Respond to Children’s Inquiry:

This study examined how teachers respond when children engage in inquiry-based deviations from a planned task. Thirty-one teachers each completed a brief science activity and accompanying worksheet with a student confederate. Teachers were given one of two goals for the study: help the students complete a worksheet or help the students learn more about science. The instructions had a significant effect on the teachers’ responses to students’ deviations. Teachers in the worksheet condition tended to discourage deviation and draw the students back to the task at hand, whereas teachers in the learn more condition were more likely to encourage and expand on the deviation. Apart from their responses to students’ deviations, nearly all teachers were classified as encouraging, suggesting that an articulated goal for the activity has a particular effect on the response to deviations. Implications for the role of teachers in the development of children’s curiosity are considered.
Exotic nucleus helium 9 and its excited states.

The ground state and several excited states of $^{9}\mathrm{He}$, the most neutron-rich nucleus to date, have been identified by means of the reaction $^{9}\mathrm{Be}({\ensuremath{\pi}}^{\ensuremath{-}}, {\ensuremath{\pi}}^{+})^{9}\mathrm{He}$. The mass excess of the ground state has been measured and it is found that the nucleus is unbound against single-neutron decay by 1.13\ifmmode\pm\else\textpm\fi{}0.10 MeV only. It is found that the excited-state spectrum of this nucleus, which is very far from the valley of stability, is in good agreement with the predictions of "no-core" shell-model calculations whose parameters were optimized for the stable nuclei in the valley.
Microfracture for osteochondral lesions of the ankle: outcome analysis and outcome predictors of 105 cases.

Purpose: The purpose of this study was to identify outcomes and outcome predictors of arthroscopic debridement with osteochondral bone stimulation (microfracture) for osteochondral lesions of the ankle. Methods: One hundred five consecutive patients with osteochondral lesions of the ankle who underwent ankle arthroscopy with microfracture were prospectively followed up for a mean of 31.6 ± 12.1 months. Study patients were evaluated at 6 weeks, 3 months, 6 months, 12 months, and annually after surgery. Assessments via a visual analog scale for pain during daily activities and sport activity, the Roles and Maudsley score, and the American Orthopaedic Foot & Ankle Society ankle and hindfoot scoring system were obtained at each visit. Outcome predictors were analyzed by logistic regression model. Results: There were no failures of treatment with lesions smaller than 15 mm. In contrast, only 1 patient met the criteria for success in the group of lesions greater than 15 mm. Statistical analysis revealed that increasing age, higher body mass index, history of trauma, and presence of osteophytes negatively affected outcome. The presence of instability and the presence of anterolateral soft-tissue scar were correlated with a successful outcome. Conclusions: This study found a strong correlation between lesion size and success across its entire population. For lesions smaller than 15 mm, regardless of location, excellent results were obtained. In addition, increasing age, higher body mass index, history of trauma, and presence of osteophytes negatively affect outcome. The presence of instability and anterolateral soft-tissue scar correlated with a successful outcome. Level of Evidence: Level IV, prognostic case series, prognostic study.
Proteomic analysis of laser microdissected melanoma cells from skin organ cultures.

Gaining insights into the molecular events that govern the progression from melanoma in situ to advanced melanoma and understanding how the local microenvironment at the melanoma site influences this progression are two clinically pivotal aspects that to date are largely unexplored. In an effort to identify key regulators of the crosstalk between melanoma cells and the melanoma-skin microenvironment, primary and metastatic human melanoma cells were seeded into skin organ cultures (SOCs) and grown for two weeks. Melanoma cells were recovered from SOCs by laser microdissection and whole-cell tryptic digests were analyzed by nanoflow liquid chromatography-tandem mass spectrometry. The differential protein abundances were calculated by spectral counting, the results of which provides evidence that cell-matrix and cell-adhesion molecules that are upregulated in the presence of these melanoma cells recapitulate proteomic data obtained from comparative analysis of human biopsies of invasive melanoma and a tissue...
An empirical model of aeolian dune lee-face airflow

Airflow data, gathered over dunes ranging from 60-m tall complex-crescentic dunes to 2-m tall simplecrescentic dunes, were used to develop an empirical model of dune lee-face airflow for straight-crested dunes. The nature of lee-face flow varies and was found to be controlled by the interaction of at least three factors (dune shape, the incidence angle between the primary wind direction and the dune brinkline and atmospheric thermal stability). Three types of lee-face flow (separated, attached and deflected along slope, or attached and undeflected) were found to occur. Separated flows, characterized by a zone of low-speed (0–3O% of crestal speed) back-eddy flow, typically occur leeward of steep-sided dunes in transverse flow conditions. Unstable atmospheric thermal stability also favours flow separation. Attached flows, characterized by higher flow speeds (up to 84% of crestal speed) that are a cosine function of the incidence angle, typically occur leeward of dunes that have a lower average lee slope and are subject to oblique flow conditions. Depending on the slope of the lee face, attached flow may be either deflected along slope (lee slopes greater than about 20°), or have the same direction as the primary flow (lee slopes less than about 20°). Neutral atmospheric thermal stability also favours flow attachment. As each of the three types of lee-face flow is defined by a range of wind speeds and directions, the nature of lee-face flow is intimately tied to the type of aeolian depositional process (i.e. wind ripple or superimposed dune migration, grainflow, or grainfall) that occurs on the lee slope and the resulting pattern of dune deposits. Therefore, the model presented in this paper can be used to enhance the interpretation of palaeowind regime and dune type from aeolian cross-strata.
A Calibration Procedure for the Assessment of Thresholds above 8000 Hz

A technique is described to estimate the sound pressure level developed by a broad frequency response transducer at the tympanic membrane. Real-ear probe tube measurements near the tympanic membran...
ALVEOLAR CAPILLARY DYSPLASIA WITH AND WITHOUT MISALIGNMENT OF THE VEINS. 1604

Alveolar capillary dysplasia (ACD) has assumed clinical importance because of the associated pulmonary hypertension that fails to respond to ECMO. We present two term infants with ACD and congenital heart disease who both failed ECMO therapy. The lungs were filled and fixed postmortem with 10% formalin at 24 cm H2O pressure. Tissue blocks from the left lung were later fixed with glutaraldehyde, cut 1 mm thick and stained with toluidine blue to assess alveolar capillary density. Regular 5-μm sections were stained with hematoxylin and eosin for lung histology. The two infants had pulmonary lobules with round, immature air spaces, lined by cuboidal epithelium separated by hypocapillarized thickened walls (ACD). One infant also had small malpositioned veins accompanying small pulmonary arteries (misalignment of the pulmonary veins; MPV), cortriatrium, and a hypoplastic left heart. The other had no MPV, pulmonary lymphangiectasia, right lung isomerism, and double outlet right ventricle. In conclusion, ACD may occur with and without MPV, possibly depending upon the stage of development during which the abnormality occurs. Eighty-five percent of infants with ACD have additional congenital abnormalities. ACD with and without MPV should be suspected in those newborns with persistent pulmonary hypertension, especially when congenital abnormalities are present.
A study of the rare-earth metal complexes

The solid rare-earth chelates of ethylenediaminetetraacetic acid were examined using thermobalance, infrared and x-ray-diffraction techniques. The lighter members are monohydrates while the heavier members are anhydrous after drying for 12 hours at 110 deg C. Infrared studies indicated that the light- member chelates have a pentadentate EDTA structure while the remaining rare earths assume a hexadentate configuration. The transition occurs with europium. X-ray-diffraction studies substantiated this structural change. Ionization constant determinations of these acids indicated that a corresponding change does not occur in solution. Examination of the alkali metal salts of these acids indicated that these rare-earth compounds are probably mutually isomorphous. The complex formation constants of the rare earths with the acetate, methoxyacetate, thioglycolate and alpha -hydroxyisobutyrate ligands were determined at 20 deg C. An ionic strength of 0.10 was used in the solutions with sodium perchlorate as the supporting electrolyte. A glass electrode was used for the potentiometric determination of the hydrogen ion concentrations. The acetate constants were found to be ln an inverted order from that predicted by ionic radii considerations. The heavier m~mbers of the rare-earth series had lower complex formation constants than the lighter members. Similar trends were noted with the methoxyacetate and thioglycolate ligands.more » The methoxy group and the sulfhydryl group contribute little if any to chelate formation with the rare-earth ions. The values of the first complex formation constant of these ligands with the rare earths are all in the range of 100 to 200 at an ionic strength of 0.10. The alpha -hydroxyisobutyrate anion formed quite stable complexes with the trivalent rare-earth ions. The formation constants found were greater than the corresponding constants of the glycolate and lactate ligands. The increase in stability is attributed to the inductive effect of the methyl group. The magnitude of the observed constants supported the postulation of a bidentate chelating action of these ligands on the rare earths. The differences in the magnitudes of the individual constants for the various rare earths confirmed previously reported data which showed that alpha -hydroxyisobutyric acid was an exceptionally good eluting agent for the rare earths in ion exchange systems.« less
Curcumin improves the therapeutic efficacy of Listeriaat-Mage-b vaccine in correlation with improved T-cell responses in blood of a triple-negative breast cancer model 4T1

Success of cancer vaccination is strongly hampered by immune suppression in the tumor microenvironment (TME). Interleukin (IL)-6 is particularly and highly produced by triple-negative breast cancer (TNBC) cells, and has been considered as an important contributor to immune suppression in the TME. Therefore, we hypothesized that IL-6 reduction may improve efficacy of vaccination against TNBC cancer through improved T-cell responses. To prove this hypothesis, we investigated the effect of curcumin, an inhibitor of IL-6 production, on vaccination of a highly attenuated Listeria monocytogenes (Listeria(at)), encoding tumor-associated antigens (TAA) Mage-b in a TNBC model 4T1. Two therapeutic vaccination strategies with Listeria(at)-Mage-b and curcumin were tested. The first immunization strategy involved all Listeria(at)-Mage-b vaccinations and curcumin after tumor development. As curcumin has been consumed all over the world, the second immunization strategy involved curcumin before and all therapeutic vaccinations with Listeria(at)-Mage-b after tumor development. Here, we demonstrate that curcumin significantly improves therapeutic efficacy of Listeria(at)-Mage-b with both immunization strategies particularly against metastases in a TNBC model (4T1). The combination therapy was slightly but significantly more effective against the metastases when curcumin was administered before compared to after tumor development. With curcumin before tumor development in the combination therapy, the production of IL-6 was significantly decreased and IL-12 increased by myeloid-derived suppressor cells (MDSC), in correlation with improved CD4 and CD8 T-cell responses in blood. Our study suggests that curcumin improves the efficacy of Listeria(at)-Mage-b vaccine against metastases in TNBC model 4T1 through reversal of tumor-induced immune suppression.
Some new variational resonating-valence-bond-type wave functions for the spin-1/2 antiferromagnetic Heisenberg model on a square lattice.

We consider a class of singlet resonanting-valence-bond wave functions on a square lattice, with the bond-length distribution as a variational parameter. This class contains the two limiting cases of the dimer wave function and of the N\'eel state. We present numerical calculations of the energy and the spin-spin correlation functions up to very large lattice sizes (180\ifmmode\times\else\texttimes\fi{}180) both for disordered states with exponentially decaying correlation functions and for ordered states. The energy of a disordered state can be within 0.1% of our best ordered state ($\frac{\ensuremath{-}0.3344J}{\mathrm{bond}}$).
Reconfigurable microstrip antenna with two-dimensional scannable beam

This paper proposes a reconfigurable microstrip antenna with two-dimensional beam scanning feature. The antenna geometry consists of two parasitic patches placed along the E and H-planes of a probe-fed patch. Each parasitic patch is loaded with a lumped varactor and DC biasing network, to effectively change its electrical size. Because the main beam direction is determined by the electrical size of the parasitic patches, electronic beam scanning is allowed by changing the capacitance value through the applied DC voltage. Consequently, Two DC control signals are used for the two-dimensional beam scanning. Operating at 2.5 GHz, the antenna shows a beam scanning that ranges from 0°to 32° in the elevation plane and from 0° to 90° in the azimuth plane. The attained peak gain value is 8.51 dBi with 0.8 dB gain variation across the entire scanning range.
Late Hemodynamic Complications of Anastomotic Surgery for Treatment of the Tetralogy of Fallot

Seventeen patients with late hemodynamic complications of anastomotic surgery for the tetralogy of Fallot have been studied. Two syndromes have been noted and both seem related to shunts of greater than ideal size. The clinical characteristics of these syndromes are delineated.
Sylvian Lipoma Causing Auditory Hallucinations: Case Report

A sylvian fissure lipoma that caused auditory hallucinations, frequent olfactory auras, and occasional visual hallucinations is reported. The patient had been diagnosed as suffering from a functional psychosis for more than a decade, with symptoms severe enough to warrant frequent psychiatric attention, including institutional care. The computed tomographic findings are discussed. The literature is reviewed and therapeutic options are proposed.
Instrument calibration of ocean bottom seismographs

To increase the accuracy of measuring sea floor motion with ocean bottom seismometers, we calibrate the seismometer system on the ocean floor. Data from the sea floor calibration, augmented with electronic and land calibration data, enables us to find the OBS transfer function to an accuracy of 0.5% in the frequency range of 0.1 to 32 Hz. We are able to distinguish between temperature, instrument and OBS ground coupling effects, all of which alter the transfer function. This paper reviews our method of calibration and discusses the effects of temperature and some of the instrument design features on the vertical seismometer transfer function.
Slit proteins: molecular guidance cues for cells ranging from neurons to leukocytes

Recent studies of molecular guidance cues including the Slit family of secreted proteins have provided new insights into the mechanisms of cell migration. Initially discovered in the nervous system, Slit functions through its receptor, Roundabout, and an intracellular signal transduction pathway that includes the Abelson kinase, the Enabled protein, GTPase activating proteins and the Rho family of small GTPases. Interestingly, Slit also appears to use Roundabout to control leukocyte chemotaxis, which occurs in contexts different from neuronal migration, suggesting a fundamental conservation of mechanisms guiding the migration of distinct types of somatic cells.
Reasons for Changes in Commitment: Variations by Courtship Type

The aim of this study was to compare partners in different types of courtship on the reasons they gave for changes in commitment. In previous research four courtship types (accelerated, accelerated-arrested, intermediate and prolonged) were identified from differences in newly weds' graphs of changes in the chance of marriage during courtship. In this study respondents' explanations for each turning point in the graph were coded as: intrapersonal/normative, dyadic, social network, or circumstantial. Significant differences among the types were found for the number of dyadic and circumstantial reasons and the proportions of intrapersonal/normative and circumstantial reasons. The types also tended to differ on the proportions of intrapersonal/normative and dyadic reasons for downturns. The results, combined with previously identified differences on partners' performance of activities together and with the social network, indicate that the types reflect distinct developmental patterns.
Effects from angle of incidence on reflection properties of reflectarray elements

Floquet analysis is applied to study the effects of incident angle on the reflection properties of unit cells. The performance of reflectarray unit cells is evaluated in terms of reflection loss and phase sensitivity. The analysis is demonstrated in three planes of interest, where extremes in performance are likely to occur. Unit cell illuminated by an incident wave with varying angles of arrival is shown to have different coupling conditions and reflection properties. Anomalous phase responses are observed for particular incident angle and polarization of the incident wave. The presented analysis showcases the sensitiveness of the reflectarray element to incident angles.
Elucidation of the Bioactive Conformation of the N-Substituted trans-3,4-Dimethyl-4-(3-hydroxyphenyl)piperidine Class of μ-Opioid Receptor Antagonists

The series of trans-3,4-dimethyl-4-(3-hydroxyphenyl)piperidines have been widely investigated as opioid receptor antagonists. One of our research goals was to explore the bioactive conformation of the N-phenethyl trans-3,4-dimethyl-4-(3-hydroxyphenyl)piperidine derivative 3, prototypical mu-opioid antagonist in this series. In this effort, the rotational degrees of freedom of the N-substituent of 3 were limited by incorporation of an ethylene bridge between the piperidine 2- or 6-position of 3 and the benzylic position of the N-phenethyl moiety. The overall modification led to a novel series of fused bicyclic derivatives of the octahydroquinolizine chemical class, conformationally restricted analogue of 3. The constrained analogues 6 and 9 showed high affinity toward the mu-opioid receptor. Compound 6 was found to be a mu-opioid antagonist, whereas the constrained analogue 9 displayed potent mu-agonist activity in vitro. This study provides additional information about the molecular determinants for mu recognition, the structural features affecting ligand binding, and the structure function relationships.
NADH:hydroxypyruvate reductase and NADPH:glyoxylate reductase in algae: partial purification and characterization from Chlamydomonas reinhardtii.

Abstract Hydroxypyruvate and glyoxylate reductase activities were measured in extracts from the unicellular green algae, Chlamydomonas reinhardtii, Chlorella vulgaris, Chlorella miniata , and Dunaliella tertiolecta . Only trace levels of these activities were detectable in the blue-green algae, Anabaena variabilis and Synechococcus leopoliensis . A NADH-dependent hydroxypyruvate reductase was purified 130-fold from Chlamydomonas to a specific activity of 18 μmol NADH oxidized · min −1 · mg protein −1 . The pH optimum was 5.0 to 7.0 in the presence of phosphate and the K m (hydroxypyruvate) was 0.05 m m . Substrate inhibition by hydroxypyruvate could be partially relieved by phosphate. The molecular weight, estimated by gel filtration, was 96,000. NADH-dependent glyoxylate reductase activity copurified with the hydroxypyruvate reductase. The K m (glyoxylate) was 10 m m , and the pH optimum was 4.5 to 8.5. A specific NADPH:glyoxylate reductase was also partially purified which did not reduce hydroxypyruvate or pyruvate. The NADPH:glyoxylate reductase had a K m (glyoxylate) of 0.1 m m and a pH optimum of 5.0 to 9.5. These reductases were compared with the pyruvate reductase of Chlamydomonas which also catalyzes the reduction of both hydroxypyruvate and glyoxylate.
Reactions of alkoxy radicals with O2. I. C2H5O radicals

C2H5ONO was photolyzed with 366 nm radiation at −48, −22, −2.5, 23, 55, 88, and 120°C in a static system in the presence of NO, O2, and N2. The quantum yield of CH3CHO, Φ{CH3CHO}, was measured as a function of reaction conditions. The primary photochemical act is and it proceeds with a quantum yield ϕ1a = 0.29 ± 0.03 independent of temperature. The C2H5O radicals can react with NO by two routes The C2H5O radical can also react with O2 via Values of k6/k2 were determined at each temperature. They fit the Arrhenius expression: Log(k6/k2) = −2.17 ± 0.14 − (924 ± 94)/2.303 T. For k2 ≃ 4.4 × 10−11 cm3/s, k6 becomes (3.0 ± 1.0) × 10−13 exp{−(924 ± 94)/T} cm3/s. The reaction scheme also provides k8a/k8 = 0.43 ± 0.13, where
MR evaluation of solid renal masses

After diagnosis of a suspicious renal mass on ultrasound or CT, renal MR imaging typically is ordered to characterize the mass further, stage the mass, or resolve discordant ultrasound and CT results. MR imaging may also be ordered in cases in which ultrasound is poor or in instances in which contrast-enhanced CT may be ill advised.
Exploring the Utility of Advanced Placement Participation and Performance in College Admission Decisions.

The current study evaluated the relationship between various operationalizations of the Advanced Placement® (AP) exam and course information with first-year grade point average (FYGPA) in college to better understand the role of AP in college admission decisions. In particular, the incremental validity of the different AP variables, above relevant demographic and academic variables, in predicting FYGPA was explored using hierarchical linear modeling. The AP variables of interest included the following: the number of AP exams the student took, the number of AP exams the student took and received a score of 3 or higher, the proportion of the number AP exams the student took out of the number AP courses offered at his or her high school, and his or her average AP score, highest AP score, and lowest AP score. Results showed that the AP predictor that most improved model fit was the average AP exam score. The final model that included multiple AP variables and most improved model fit included the average AP sc...
Water vapor permeability of mammalian and fish gelatin films

Water vapor permeability of cold- and warm-water fish skin gelatins films was evaluated and compared with different types of mammalian gelatins. Alaskan pollock and salmon gelatins were extracted from frozen skins, others were obtained from commercial sources. Water vapor permeability of gelatin films was determined considering differences on percent relative humidity (%RH) at the film underside. Molecular weight distribution, amino acid composition, gel strength, viscoelastic properties, pH, and clarity were also determined for each gelatin. Water vapor permeability of cold-water fish gelatin films (0.93 gmm/m2hkPa) was significantly lower than warm-water fish and mammalian gelatin films (1.31 and 1.88 gmm/m2hkPa, respectively) at 25 °C, 0/80 %RH through 0.05-mm thickness films. This was related to increased hydrophobicity due to reduced amounts of proline and hydroxyproline in cold-water fish gelatins. As expected, gel strength and gel setting temperatures were lower for cold-water fish gelatin than either warm-water fish gelatins or mammalian gelatins. This study demonstrated significant differences in physical, chemical, and rheological properties between mammalian and fish gelatins. Lower water vapor permeability of fish gelatin films can be useful particularly for applications related to reducing water loss from encapsulated drugs and refrigerated or frozen food systems.
"Properly disposed of": a history of embryo disposal and the changing claims on fetal remains

This paper explores recent controversies concerning the disposal of embryonic and fetal remains in order to ask how such remains came to be classified as "medical waste." Based on archival research into the social history of human embryo collecting in Baltimore, Maryland, in the early 20th century, I argue that the classification of embryos and fetal remains as medical waste can be traced to a pragmatic alliance between embryologists and state functionaries. Embryologists relied on the state to assist them in acquiring thousands of human embryo remains for scientific study, while state authorities relied on embryologists to provide authoritative knowledge that could be used to facilitate state control over nascent citizens. This alliance contributed to the development of an "embryological worldview," in which human embryos were cast as objective biological "specimens" of use only to embryologists. This exclusive view of the social value of embryos and fetal tissue is now being challenged as other constituencies claim jurisdiction over the remains in order to advance diverse social agendas.
Plasmonic field and efficiency enhancement in crystalline thin film photovoltaics

We report the design and optimization of plasmonic thin film photovoltaics (TFPV) based on single crystalline Si nanomembranes, transferred onto ITO/plastic solar cells. Due to the presence of Fabry-Perot (FP) interferences, both near and far field plasmonic field enhancements are modulated by thin film thicknesses. The placement of absorption region (junction location and/or quantum well location) is critical in TFPV efficiency improvement. For TFPV thin film thickness between 200-500 nm, we obtained field enhancement up to 100%, and cell efficiency improvement up to 35%, assuming the standard test one sun AM1.5 radiation conditions. The efficiency enhancement for 200 nm silver particles decreases rapidly with the increase of thin film thicknesses, while we observed less change in cell efficiency enhancement for smaller 100 nm silver particles. Additionally, we observed a relatively large process tolerance window for the size, shape, and placement of Ag nanoparticles, formed by the annealing of ultra-thin Ag thin films.
A Collaborative Longitudinal Study of Aging with Spinal Cord Injury: Overview of the Background and Methodology

Changes associated with aging in people living with spinal cord injury (SCI) may adversely affect both physical and psychosocial functioning. This article describes a 15-year multicenter collaborative study exploring the incidence and prevalence of health and psychosocial conditions that accompany living many years with SCI. Three episodes of data collection occurred over this time span, and the study design and methodology are described in detail.
Two Photon Spectroscopy of Dithienyl Polyenes

To understand the properties of light-sensitive compounds used in optical limiters having photoinduced charge transfer mechanisms, we have investigated the photophysics of a series of di(2-thienyl-3,3'-butyl)polyenes. Spectroscopic measurements, including UV/Vis, fluorescence, fluorescence lifetimes, fluorescence quantum yields, triplet state lifetime, solvent effects and two-photon absorption coefficient were obtained as a function of the number of double bonds(n = 1-5). Trends in the data reflected the ordering, energy gap between and mixing of 1 B u * and 1 A g * excited state configurations.
Left ventricular assist devices: an ethical analysis.

United States statistics continue to indicate that the human donor heart pool does not and will not meet the great demand for hearts. For those patients unresponsive to maximal medical therapy (approximately 60,000 patients per year), cardiac transplantation is currently their best hope for increased survival. To address the need for additional end-stage congestive heart failure (CHF) therapy options, three medical device manufacturers have developed implantable left ventricular assist devices (LVAD) which act as a pump for hemodynamic support of the patient’s diseased heart. Although LVADs have been shown to improve patient disease state prior to organ transplantation. LVADs do nothing to increase the pool of human donor hearts, and they negatively impact the United Network for Organ Sharing (UNOS) waiting list by increasing the size of the waiting pool. This paper identifies and explores the ethical challenges presented by the use of LVADs as a bridging technology for heart transplant candidates. Although LVADs raise some ethical concerns, these concerns are outweighed by the proven medical efficacy of these devices. Thus, this technology should continue to be used and further developed.
A model of convection and corotation in Jupiter's magnetosphere: Ulysses predictions

The Ulysses Jupiter encounter will include the first spacecraft pass through the dusk magnetosphere and will allow new tests of Jovian convection and corotation models. The Cheng and Krimigis (1989) model is extended to suggest that corotation lag occurs principally within the magnetodisk proper, which extends out to about 60-70 Rj. It is predicted that outside this radius, in the premidnight sector, spin-up to near corotation may occur owing to a local reduction in the outward mass transport rate. The mass loss may occur mainly in the dawn sector, to the magnetospheric wind and the dawn magnetosheath.
Contact angles during monolayer deposition

Abstract Preliminary results are reported in a study of the contact angles and adhesional energy changes during the transfer of monolayers from the air-water interface to solid (hydrophobic glass) supports. The technique used is the vertical-plate method of Neumann, as modified for this application by Clint and Walker. In building up cadmium arachidate layers, it is found that the hydrophobic (immersion) adhesion energy depends slightly on pH and concomitant extent of soap formation in the film, suggesting that polar group interactions, while small, are not negligible. (The narrow pH range of condensation for cadmium arachidate requires the use of a stable buffer system such as acetate, rather than bicarbonate, for adequate pH control.) The acute contact angles observed during the withdrawal step in layer buildup change slowly after motion is stopped. While no quantitative interpretation is yet possible, it is suggested that this may reflect water and ion redistribution in the interfacial region; such redistribution would also contribute previously ignored surface excess terms to the interfacial energies involved.
Understanding Contracting Performance An Empirical Analysis

This study explores the outcomes of contractual relationships between American local governments and private service providers. Researchers have approached the issue of contract administration and performance from a variety of theoretical perspectives, each providing its own insight into how to manage contractual relationships effectively. The analysis, which is based on a unique data set of more than 400 contractual relationships, focuses on the effects of contract monitoring, competition, and trust on contracting performance. The results of the analysis indicate that trust has an independent positive effect on overall contracting performance, as well as on eight specific dimensions of performance. In most of the models tested, monitoring and competition were not related to contracting performance. The relationship between monitoring and contracting performance appears to be more complex than previously thought, involving interactions with moderating variables.
Hybrid Shoot Formation from Fused Daucus carota and D. capillifolius Protoplasts

Summary Protoplasts from line C123, a 5-methyltryptophan (5MT) and azetidine-2-carboxylate (A2C) resistant cell line of Daucus carota that has lost the ability to regenerate whole plants, were fused using dextran with protoplasts of suspension cultured D. capillifolius. Somatic hybrids were selected initially by culture in 5MT levels which inhibit the growth of D. capillifolius and then for green pigmentation and embryoid formation. The fusion and selection produced plants, lacking roots, with leaves showing intermediate morphology between those of the parents. The chromosome numbers of embryoid root tips and suspension cultures were near 36 which is the sum of the parents. Analysis of four isozymes following electrophoresis showed that malate dehydrogenase and peroxidase resembled the carrot parent while leucine aminopeptidase was like D. capillifolius. The superoxide dismutase pattern was like that expected from a hybrid. Callus initiated from the hybrid plants showed resistance to both 5MT and A2C with the resistance being expressed as semi-dominant and dominant characters, respectively. The feedback control characteristics of anthranilate synthase correlate with the 5MT resistance in the parental and hybrid lines. These results demonstrate that amino acid analog resistance and plant regeneration ability can be used as complementing markers to select for fusion hybrids since both can be expressed in the hybrids.
Ligand-Independent Androgen Receptor Variants Derived from Splicing of Cryptic Exons Signify Hormone-Refractory Prostate Cancer

Suppression of androgen production and function provides palliation but not cure in men with prostate cancer (PCa). Therapeutic failure and progression to hormone-refractory PCa (HRPC) are often accompanied by molecular alterations involving the androgen receptor (AR). In this study, we report novel forms of AR alteration that are prevalent in HRPC. Through in silico sequence analysis and subsequent experimental validation studies, we uncovered seven AR variant transcripts lacking the reading frames for the ligand-binding domain due to splicing of "intronic" cryptic exons to the upstream exons encoding the AR DNA-binding domain. We focused on the two most abundantly expressed variants, AR-V1 and AR-V7, for more detailed analysis. AR-V1 and AR-V7 mRNA showed an average 20-fold higher expression in HRPC (n = 25) when compared with hormone-naive PCa (n = 82; P < 0.0001). Among the hormone-naive PCa, higher expression of AR-V7 predicted biochemical recurrence following surgical treatment (P = 0.012). Polyclonal antibodies specific to AR-V7 detected the AR-V7 protein frequently in HRPC specimens but rarely in hormone-naive PCa specimens. AR-V7 was localized in the nuclei of cultured PCa cells under androgen-depleted conditions, and constitutively active in driving the expression of canonical androgen-responsive genes, as revealed by both AR reporter assays and expression microarray analysis. These results suggest a novel mechanism for the development of HRPC that warrants further investigation. In addition, as expression markers for lethal PCa, these novel AR variants may be explored as potential biomarkers and therapeutic targets for advanced PCa.
A criterion for craze formation

A general criterion for craze formation is presented. Crazes are deformation zones that are common to both glassy and semicrystalline polymers. Crazes are composed primarily of fibrils. This paper attempts to describe the process that transforms unoriented glassy and semicrystalline polymeric solids into a fibrous state. The criterion for crazing discussed is a local phase transition. The transition occurs at the draw temperature. Unoriented solid-phase macromolecules, at local high-stress regions, undergo a transition to the elastomeric phase. Rapid extension and accompanying resolidification produce the fibrous morphology of craze fibrils. Cavitation of the deforming rubber phase ocurs because the local length increase is riot compensated for by an overall area decrease. Craze formation in glassy polymers has long been suspected to involve a local solid-to-rubber phase change. To relate crazes in glassy and semicrystalline polymers, one can assume that a solid-to-rubber phase change is required to produce craze fibrils in semicrystalline polymers. The transient melt phase would undergo rapid elongation, causing the formation of extended chain crystallites. These subsequently nucleate the remaining melt, which then crystallizes epitaxially as lamellae. Crystallization during flow would, therefore, be the mechanism of fiber formation.
EFFECTS OF TEMPERATURE AND PO2 ON THE HEART RATE OF JUVENILE AND ADULT FRESHWATER MUSSELS (BIVALVIA: UNIONIDAE)

Abstract The heart rate of juvenile and adult Utterbackia imbecillis and Pyganodon cataracta was monitored during experimental manipulation of temperature and pO 2 . Animals that had been acclimated to 15 and 25°C for 1 week were exposed to an ascending series of temperatures (10, 15, 20, 25 and 30°C). The effects of oxygen tension on heart rate were assessed by subjecting mussels to a descending series of oxygen tensions (100, 75, 50, 25, 5 and 0% air saturation). Results indicated that the heart rates of juvenile and adult mussels are markedly affected by experimental temperature, with Q 10 's approaching 4.5. Acclimation had no effect on adult mussels. However, juvenile U. imbecillis exhibited inverse acclimation; whereas, juvenile P. cataracta fit a typical pattern of acclimation (Prosser's Type IVA). When exposed to a descending series of oxygen tensions, adult U. imbecillis maintained a constant heart rate until a significant increase occurred at 25% air saturation, followed by a significant decrease at 5 and 0%. Juvenile U. imbecillis maintained a constant rate until bradycardia occurred at pO 2 's of 5 and 0% air saturation. Juvenile and adult P. cataracta exhibited similar patterns, with sustained rates until a significant decrease occurred at 0% air saturation. The differences in acclimation patterns exhibited by juvenile and adult mussels may reflect differences in the thermal conditions experienced by these two life-history stages; however, there are no data available that characterize the microhabitat of juvenile freshwater mussels. Utterbackia imbecillis appears to be more sensitive to low oxygen levels than P. cataracta , and the heart rate of juveniles of both species is more responsive to hypoxia than that of adults.
Visual and Digital Texts

This column provides reviews of adolescent and adult visual and digital texts and provides a valuable resource for visual and digital text selection in- and outside the classroom.
Online Education from the Perspective of Community College Students within the Community of Inquiry Paradigm

This article describes a qualitative inquiry that explored the phenomenon of online learning on a community college campus within the paradigm of Community of Inquiry (CoI). The learning experience of 15 community college students taking fully online courses was examined in-depth for evidence of social, cognitive, and instructional domains identified by CoI as critical components for the facilitation of a meaningful learning experience in computer-mediated environments. Findings conveyed suppressed social, cognitive, and teaching presence; and as a result, a meaningful learning experience was not achieved for the participants. Additionally, first-time online learners manifested a unique learning experience that warrants further investigation. Findings from this study raise questions about the pedagogical soundness of fully online courses for community college students. Future research should examine online learning as a distinct pedagogy and focus more intently on the teaching and learning process.
POPULATION DYNAMICS OF SEX-DETERMINING ALLELES IN HONEY BEES AND SELF-INCOMPATIBILITY ALLELES IN PLANTS

Mathematical theories of the population dynamics of sex-determining alleles in honey bees are developed. It is shown that in an infinitely large population the equilibrium frequency of a sex allele is 1/n, where n is the number of alleles in the population, and the asymptotic rate of approach to this equilibrium is 2/(3n) per generation. Formulae for the distribution of allele frequencies and the effective and actual numbers of alleles that can be maintained in a finite population are derived by taking into account the population size and mutation rate. It is shown that the allele frequencies in a finite population may deviate considerably from 1/n. Using these results, available data on the number of sex alleles in honey bee populations are discussed. It is also shown that the number of self-incompatibility alleles in plants can be studied in a much simpler way by the method used in this paper. A brief discussion about general overdominant selection is presented.
Nonlinear and Isothermal Neural-Based Modeling of the Dual Gate MESFET

In this paper, the authors present neural-based large-signal and isothermal models for the dual gate MESFET as efficient alternatives to existing nonlinear models for such a complex device. The neural model is a combination of two submodels, namely, a static model represented by dc I-V characteristics and a dynamic model represented by pulsed I-V characteristics. The isothermal model is based on pulsed I-V measurements to better represent the RF device behavior and to neutralize the effect of channel self-heating on model accuracy. Insights on the discrepancy between model parameter values extracted from pulse and from dc measurements are also discussed. The measurement and model data are in very good agreement with global model errors of less than 1%.
Anticancer Effects of Combined Î³-Tocotrienol and PPARÎ³ Antagonist Treatment are Associated with a Suppression in Adipogenic Factor Expression

Cancer cells reprogram their metabolism to meet the demands of accelerated growth. Glucose is the primary source of energy for cancer cells, but under conditions of high-energy demand lipids and free fatty acids become increasingly important. PPAR I³ is a member of the nuclear receptor superfamily and acts to regulate adipocyte differentiation and lipid metabolism. However, in many types of cancer, PPAR I³ activity is elevated in order to increase production of adipogenic factors [1, 2]. I³ -Tocotrienol is an isoform of vitamin E that displays potent anticancer activity [3]. Previous studies have shown that the antiproliferative effects of combined treatment of A£ -tocotrienol with PPAR I³ antagonists was associated with a reduction in PPAR I³ activity, expression of PPAR I³ and RXR, and suppression in Akt activation in MCF-7 and MBA-MB-231 human breast cancer cells [4]. The present study was conducted to determine the effects of combination treatment with these agents on adipogenic factor levels in rapidly proliferating human breast cancer cells. Western blot and qRT-PCR studies showed that combined treatment of I³ -tocotrienol with PPAR I³ antagonists not only suppressed the adipogenic proteins, C/EBPI² and SREBP-1c, but also decreased their target lipogenic enzymes, ap2, FAS, and HMGCoR. However, treatment effects were also observed in PPAR I³ silenced breast cancer cells, indicating that these effects are mediated through PPAR I³ -independent mechanism. These findings suggest the combined treatment of A£ -tocotrienol with PPAR I³ antagonist may have potential as a therapeutic strategy in the treatment of breast cancer.
Isolated short-wavelength sensitive cones can mediate a reflex accommodation response

Both long- and middle-wavelength sensitive cones mediate the reflex accommodation signal but the contribution from the short-wavelength sensitive cones is unknown. A short-wavelength sensitive cone contribution could extend the range of the signed defocus signal from chromatic aberration. The aim was to determine whether isolated short-wavelength sensitive cones mediate reflex accommodation independently of long- and middle-wavelength sensitive cones. Accommodation was monitored continuously (eight subjects) to a sine-wave grating (3 cpd; 0.53 contrast) moving with a sum of sines motion in a Badal optometer. Two illumination conditions were used: a 'blue' condition that isolated short-wavelength sensitive cones, and a 'white' control condition that stimulated all three cone types. Of the eight subjects, two responded equally in the 'white' and 'blue' condition, four gave reduced responses in the 'blue' condition and two failed to respond in both conditions. The mean response in the 'blue' condition was reduced by 50% compared to the 'white' condition. Further analysis indicated that four of the eight subjects gave responses that were considerably greater than noise (S.D.>1.82) when short-wavelength sensitive cones were isolated. Some subjects can accommodate using only S-cones.
HAMILTONIAN SQUARE ROOTS OF SKEW HAMILTONIAN QUATERNIONIC MATRICES

Criteria for existence of Hamiltonian quaternionic matrices that are square roots of a given skewHamiltonian quaternionic matrix are developed. The criteria are formulated in terms of respective canonical forms of skewHamiltonian quaternionic matrices. The Hamiltonian property is understood with respect to either the quaternionic conjugation, or an involutory antiautomorphism of the quaternions which is different from the quaternionic conjugation. Many results are stated and proved in a more general framework of symmetric and skewsymmetric matrices with respect to an invertible matrix which is skewsymmetric relative to an involutory antiautomorphism.
Raw (unpasteurized) milk: are health-conscious consumers making an unhealthy choice?

An increasing number of health-conscious consumers are seeking natural, unprocessed foods, including fresh, locally grown produce, eggs, poultry, and meats. Concomitant with this consumer interest, the US Department of Agriculture created Know Your Farmer, Know Your Food and the Farmers Market Promotion Program [1, 2]. These governmental programs seek to improve nutritional choices made by Americans with the goal to reduce the incidence of obesity, diabetes mellitus, and other chronic illnesses [3]. However, in the midst of trends toward choosing less processed foods is a growing consumer demand for raw (unpasteurized) dairy products. Advocates promote raw milk for its better taste and purported health benefits and as a way for consumers to support small dairies and local agriculture. At the same time, the public health community speaks in a nearly unanimous voice to warn consumers, farmers, and retail stores that sell the products about the