cssi/SciSciGPT-SciSciNet huggingface dataset:
Modelling oblique hypervelocity impact phenomena using elementary shock physics

Summary During their missions in space, spacecraft are subjected to high velocity impacts by orbital debris particles. Such impacts are expected to occur at non-normal incidence angles and can cause severe damage to the spacecraft as well as to its external flight-critical components. In order to ensure crew safety as well as the proper function of internal and external spacecraft systems, the characteristics of debris clouds generated by such impacts must be known. In this paper, a first-principles-based analytical model is developed for the characterization of the penetration and ricochet debris clouds created by the hypervelocity impact of a spherical projectile on a thin aluminum plate. This model employs normal and oblique shock wave theory to characterize the penetration and ricochet processes. The predictions of the model are compared against numerical and experimental results.
Comparative Evaluation Between N-Acetyl Cysteine and N-Acetyl Cysteine Amide in Acetaminophen-Induced Oxidative Stress

Acetaminophen (APAP) is the most widely used pharmaceutical analgesicantipyretic agent in the world, but its toxicity is a common cause of drug-induced hepatotoxicity. With APAP toxicity, cellular glutathione (GSH) is depleted. This results in the availability of N-acetyl-p-benzoquinone imine (NAPQI), is a toxic metabolite of APAP that binds to cellular macromolecules, which leads to cell necrosis. N-acetyl cysteine (NAC), a GSH precursor, is the only approved antidote for an acetaminophen overdose. It is a negatively charged molecule that diminishes its penetration into the cells, thereby requiring fairly high doses that increase the severity of side effects. In addition, oral and I.V. administration of NAC in a hospital setting is laborious and costly. Recently, NACA, an amide form of NAC, which is neutral at physiological pH has been developed to improve NAC’s bioavailability. Therefore, in this study, we conducted an investigation to determine the mechanism of APAP-induced hepatotoxicity. We also evaluated the hepatoprotective effectiveness of NACA and compared it with NAC in the hepatic cell line, HepaRG. This comparison was based on several oxidative stress parameters, including the levels of intracellular reactive oxygen species, GSH, various antioxidant enzyme activities, and lactate dehydrogenase levels. In conclusion, NACA protected HepaRG cells against damage induced by acetaminophen toxicity and may, therefore, be a more useful antidote than NAC (the only approved antidote).
A review of models for heterojunction band offsets

Abstract A description and analysis is given of the theories governing the nature and magnitude of the conduction and valence band discontinuities in heterojunctions. These range from the original Anderson model of 1962[1] to the recently published position-dependent calculations of the present authors[2,3].
Dehydrogenation of propane over Pt/KL catalyst: Investigating the role of L-zeolite structure on catalyst performance using isotope labeling

Abstract Dehydrogenation of propane using an equimolar mixture of propane-d0 and propane-d8 was investigated over 1%Pt/KL and 1%Pt/SiO2 at atmospheric pressure and different reaction temperatures. A normal kinetic isotope effect exists (kH/kD = 1.4–1.5) when the reaction is conducted on Pt/KL at different temperatures (400, 500, and 600 °C), suggesting that C–H bond activation is involved in the kinetically relevant steps. Furtheremore, there is hardly any H–D exchange in the recovered propane during dehydrogenation at temperatures above 400 °C, suggesting that adsorption and subsequent dehydrogenation of propane are essentially irreversible and that C–H bond activation is the rate determining step. Unlike the case of hexane aromatization, the unique structure of L-zeolite does not help in controlling the entry of propane molecules into the lobes of the L-zeolite containing the active sites; hence, bimolecular reactions do occur, leading to coke formation and catalyst deactivation.
Status of neoadjuvant therapy for resectable pancreatic cancer.

Neoadjuvant therapy for patients with localized pancreatic adenocarcinomas was first reported in 1980, in a series of patients treated with radiation therapy alone. 1 Of the 17 tumors treated, 15 were declared to be either unresectable or of borderline resectability by the surgeon who performed the initial exploratory celiotomy. The intent of the radiation therapy was to increase the resectability rate and to decrease the incidence of local and systemic recurrence. Six of the 17 patients underwent resection, and 2 of those lived for more than 5 years. Conclusions from the results of radiotherapy were that (1) preoperative radiation therapy is feasible and safe, (2) a thorough look for metastatic disease should be undertaken after completion of radiation therapy (because one-third of the patients demonstrated metastases after radiation treatment), and (3) response to radiation therapy should be an important parameter for selecting candidates for resectional surgery. It was also suggested that chemotherapy be tried as a radiation sensitizer. The first report of neoadjuvant radiation therapy combined with chemotherapy was published 10 years later. 2 Fourteen patients were treated; 10 underwent resection, many with excellent histologic responses to treatment. The emphasis here was on increased resectability of locally advanced cancers and increased histopathologic response to the chemoradiation. Two years later, Evans and colleagues 3 reported their experience at the MD Anderson Cancer Center (MDACC) with patients who had potentially resectable disease. Contained within that publication was a grading scale for measuring the histologic response of pancreatic cancer to neoadjuvant treatment, which is still used today. Of the 28 patients treated, 5 developed metastatic disease during the period of neoadjuvant therapy. In every subsequent report of neoadjuvant therapy, at least 15% of
Effect of epidermal growth factor on cultured adult rat hepatocytes.

Abstract When adult rat hepatocytes were cultured in plastic Petri dishes in a medium containing insulin and glucagon, supplementation with epidermal growth factor (EGF) had a pronounced effect on their viability, morphology, and biochemical integrity. Transmission and scanning electron microscopic studies showed that after 1 week cells denied EGF accumulated numerous non-electron-dense bodies and filamentous whorls, had irregular nuclei, and exhibited atypical cell surfaces. In contrast, cells grown for 2–3 weeks in the presence of EGF had well-preserved cellular organelles and remained as an epithelial-like monolayer. After 3 weeks EGF-exposed cultures were still inducible for liver-specific tyrosine aminotransferase, and both rat albumin and rat transferrin were recoverable from the culture medium. Virtually no viable cells were present at 3 weeks in EGF-deprived cultures.
Differentiation and magma mixing on Kilauea's east rift zone: A further look at the eruptions of 1955 and 1960. Part II. The 1960 lavas

New and detailed petrographic observations, mineral compositional data, and whole-rock vs glass compositional trends document magma mixing in lavas erupted from Kilauea's lower east rift zone in 1960. Evidence includes the occurrence of heterogeneous phenocryst assemblages, including resorbed and reversely zoned minerals in the lavas inferred to be hybrids. Calculations suggest that this mixing, which is shown to have taken place within magma reservoirs recharged at the end of the 1955 eruption, involved introduction of four different magmas. These magmas originated beneath Kilauea's summit and moved into the rift reservoirs beginning 10 days after the eruption began. We used microprobe analyses of glass to calculate temperatures of liquids erupted in 1955 and 1960. We then used the calculated proportions of stored and recharge components to estimate the temperature of the recharge components, and found those temperatures to be consistent with the temperature of the same magmas as they appeared at Kilauea's summit. Our studies reinforce conclusions reached in previous studies of Kilauea's magmatic plumbing. We infer that magma enters shallow storage beneath Kilauea's summit and also moves laterally into the fluid core of the East rift zone. During this process, if magmas of distinctive chemistry are present, they retain their chemical identity and the amount of cooling is comparable for magma transported either upward or laterally to eruption sites. Intrusions within a few kilometers of the surface cool and crystallize to produce fractionated magma. Magma mixing occurs both within bodies of previously fractionated magma and when new magma intersects a preexisting reservoir. Magma is otherwise prevented from mixing, either by wall-rock septa or by differing thermal and density characteristics of the successive magma batches.
Taenia crassiceps: effect of normal and immune serum on metacestodes in vitro.

Abstract The effect of normal and immune serum on Taenia crassiceps larvae in vitro was assessed by Evans blue dye uptake and electron microscopy. Normal guinea pig, rabbit, goat, and fetal calf serum did not have any significant detrimental effects upon the larvae after 7 days of culture in vitro . Culture for 7 days in normal mouse serum resulted in some loss of tegumental microtriches but the tegument itself remained intact. Culture in hyperimmune rabbit serum resulted in complete loss of the tegument and disruption of subtegumental structures within 48 hr. The effects of immune mouse serum in vitro closely paralleled those previously seen during early immune damage in vivo . Immune serum taken 2 to 4 weeks after secondary intraperitoneal infection with T. crassiceps metacestodes caused loss of the larval tegument and degeneration of the subtegumental tissues after 7 days in culture, whereas immune mouse serum taken 6 weeks after secondary infection caused only minor ultrastructural changes and appeared to be less toxic to larvae than normal mouse serum. Although complement appeared to increase the number and severity of the tegumental lesions, the presence of heat-labile components of complement was not essential for mediation of tegumental damage by immune mouse serum.
Chemical and electrical receptors on the surface of squid giant axons.

3. Dude& J. Voltage dependence of amplitude and time course of inhibitory synaptic current in crayfish muscle. f’fli&ws Arch. ges. Physiol. 371: 167-174, 1977. 4. Fatt, P. and B. Katz. The effect of inhibitory nerve impulses on a crustacean muscle fibre. 1. Ph,vsio/. 121: 37&388, 1953. 5. Gage, P. W. Generation of end-plate potentials. Ph,ssio!. Rev. 56: 177-247, 1976. 6. Onodera, K. and A. Takeuchi. Inhibitor postsynaptic current in voltage-clamped crayfish muscle. Ntrtrtr~ 263: 153-154, 1976. 7. Onodera, K. and A. Takeuchi. Effects of membrane potential and temperature on the excitatory post-synaptic current in the crayfish muscle. J. Physiol. 276: 183-192, 1978. 8. Onodera, K. and A. Takeuchi. An analysis of the inhibitory post-synaptic current in the voltage-clamped crayfish muscle. .i. Physiol. In press, 1978. 9. Takeuchi, A. and N. Takeuchi. Localized action of gammaamino-butyric acid on the crayfish muscle. J. Physiol. 177: 22S238, 1968. 10. Takeuchi, A. and N. Takeuchi. Variations in the permeability properties of the inhibitory post-synaptic membrane of the crayfish neuromuscular junction when activated by different concentrations of GABA. .I. Physiol. 217: 341-358, 1971.
A tool supporting query optimization and program transformation techniques

In this paper we propose the integration of query optimization and program transformation technologies in a second generation optimizer generator called OG. The input to OG is a high-level specification of the strategy transformations done by each module of a query optimizer. OG's design is intended to support the specification and automatic implementation of extensions to data-access languages.
Precipitation strengthening in nanocomposite Cr/Cu–Cr multilayer films

Precipitation strengthening in nanostructured metallic multilayer (NMM) films of Cr/Cu–Cr was studied using nanoindentation and electron microscopy. Magnetron-sputtered NMM films having layer thicknesses of 10, 20 and 30 nm were prepared at room temperature (RT) and 100 °C. Some of the RT-deposited films were annealed at 100 °C for 30 min. Cr was introduced in the Cu–Cr layers by using a Cu–Cr target (95 at.% – 5 at.%) target. A significant increase in nanoindentation hardness was observed in the Cr/Cu–Cr. A reduction of hardness dependence on layer thickness was also observed in the Cr/Cu–Cr, such that sample having a layer thickness of 30 nm provides the equivalent strength of a 10/10 nm Cr/Cu. Uniformly distributed Cr particles in the Cu–Cr layers are key strengthening features in these new Cr/Cu–Cr NMM films. A single dislocation-based model was used to correlate the observed mechanical behaviours and microstructure. The model predicts similar trend observed from the experimental results, suggesting t...
Analytic and numerical methods for cosmic string evolution

Abstract We provide a short overview of our recent work on the evolution of cosmic string networks, discuss both the analytic and numerical approaches to the problem. We briefly discuss some cosmological consequences of both Goto-Nambu and superconducting strings.
The effect of occlusal discrepancies on periodontitis. II. Relationship of occlusal treatment to the progression of periodontal disease.

Background: A causal relationship between occlusal discrepancies and periodontal disease has been postulated in the past. However, minimal data are available concerning the effect of treatment of occlusal discrepancies on periodontitis. Methods: The records from a private practice limited to periodontics were reviewed to find patients who had complete periodontal examination records, including occlusal analysis, that were recorded at least 1 year apart. Patients who fit these criteria were divided into a group that had none of the recommended treatment (untreated n = 30), those who had only nonsurgical treatment (partially treated n = 18), and a control group that had completed all recommended treatment (surgically treated n = 41). The data for each tooth of each patient, including occlusal status, were placed in a database and analyzed using the generalized estimating equations method. Results: Worsening in overall clinical condition, as measured by worsening in prognosis, indicated that teeth with no in...
Identification of protein coding regions in the human genome by quadratic discriminant analysis

A new method for predicting internal coding exons in genomic DNA sequences has been developed. This method is based on a prediction algorithm that uses the quadratic discriminant function for multivariate statistical pattern recognition. Substantial improvements have been made (with only 9 discriminant variables) when compared with existing methods: hexon [Solovyev, V. V., Salamov, A. A. & Lawrence, C. B. (1994) Nucleic Acids Res. 22, 5156–5163] (based on linear discriminant analysis) and grail2 [Uberbacher, E. C. & Mural, R. J. (1991) Proc. Natl. Acad. Sci. USA 88, 11261–11265] (based on neural networks). A computer program called mzef is freely available to the genome community and allows users to adjust prior probability and to output alternative overlapping exons.
Evolving ideas about the male refractory period

The male refractory period (MRP) continues to be a topic of discussion and debate within the field of sexual medicine. To date explanations rely on central descending (efferent) influences involving specific neurotransmitter systems. Herein we explore the issue of the male refractory period, identifying problems with current explanations, specifying the parameters of an adequate model, and suggesting possible mechanisms mediating this phenomenon. We review the literature regarding existing explanations for the MRP and look to other systems of physiological regulation that might provide a model for the conceptualization of the MRP. Our approach differs from traditional explanations in that it emphasizes the possible roles of various peripheral, rather than central, feedback (afferent) systems that affect peripheral autonomic functioning and response. Yet our approach is consistent with other peripheral regulatory feedback systems controlling autonomic response related to such processes as heart rate, respiration, and gut motility. Although direct empirical research supporting our approach is lacking, sufficient evidence exists to support the idea that such processes are not only possible but likely with respect to the male refractory period. We suggest several lines of research that might provide empirical support for this approach.
COPASutils: An R Package for Reading, Processing, and Visualizing Data from COPAS Large-Particle Flow Cytometers

The R package COPASutils provides a logical workflow for the reading, processing, and visualization of data obtained from the Union Biometrica Complex Object Parametric Analyzer and Sorter (COPAS) or the BioSorter large-particle flow cytometers. Data obtained from these powerful experimental platforms can be unwieldy, leading to difficulties in the ability to process and visualize the data using existing tools. Researchers studying small organisms, such as Caenorhabditis elegans, Anopheles gambiae, and Danio rerio, and using these devices will benefit from this streamlined and extensible R package. COPASutils offers a powerful suite of functions for the rapid processing and analysis of large high-throughput screening data sets.
Power earth auger modification for waste extraction from pit latrines

The extraction auger was developed to meet the need for a low cost, effective method to empty pit latrines in difficult to access locations. The basic design consists of a motor that rotates an auger inside a pipe, lifting waste from a pit and depositing it into containers through a wye fitting at the top of the device. Laboratory testing of the auger showed increases in flow rates with increasing auger rotational speed and waste viscosity. An auger with an external hydraulic drive was capable of lifting dairy waste over 2.5 m, at flow rates of over 125 liters per minute. Field-testing showed the equipment was effective at lifting medium viscosity wastes containing a mixture of liquid and solid material. However, the auger was not effective in removing low viscosity, liquid waste that would flow backward down the auger reducing lifting efficiency. The auger was capable of drilling into dense solid waste, forming a ‘posthole’ in the waste. However, since the dense solid waste would not flow towards the auger intake, actual waste removal from the pit was limited. Improved methods are needed to mix liquid and solid waste in pits prior to removal with the extraction auger or other technologies.
Oxygen Effects in Mechanically Alloyed Si80 Ge20 Doped with GaP and P

A neutron activation study was performed to follow the total oxygen content during the preparation sequence of mechanically alloyed Si-20 at.% Ge n-type alloys using both elemental powders and chunk starting materials. The Si-20 at. % Ge alloys were doped with 1.6 at. % GaP and 3.4.at. % P and the total oxygen concentration was measured in the starting materials, after six hours of mechanical alloying in a helium environment, after hot pressing, and after a short 1100°C soak in fused silica ampoules. The alloys containing high oxygen levels showed low carrier mobility and low thermal conductivity whereas those containing low oxygen showed high mobility and thermal conductivity. The microstructure, as observed by optical metallography and SEM, was found to differ greatly with oxygen content as the low oxygen alloys showed relatively large, well defined grains and the high oxygen alloys showed evidence of poor sintering and limited grain growth.
Function of a Mycobacterial Major Facilitator Superfamily Pump Requires a Membrane-Associated Lipoprotein

The lprG-Rv1410c operon is critical for the survival of Mycobacterium tuberculosis during infection, but very little is known about the functions of its proteins. LprG is a lipoprotein, and Rv1410c encodes the major facilitator superfamily small molecule transporter P55. P55 likely exports small molecules outside of the bacterial cell, but the function of LprG is unclear. A deletion of the homologous operon in Mycobacterium smegmatis is more susceptible to ethidium bromide, and drug resistance is restored by the intact operon from M. tuberculosis. The multidrug resistance pump inhibitor reserpine inhibits resistance to ethidium bromide in both wild-type M. smegmatis and the complemented mutant, suggesting that P55-mediated transport is responsible for drug resistance and that ethidium bromide is a novel substrate for P55. In addition to hypersensitivity to ethidium bromide, cells that lack the lprG-Rv1410c operon display abnormal colony morphology and are defective for sliding motility, properties that suggest an alteration of cell wall composition. Strikingly, both ethidium bromide transport and normal cell surface properties require functional P55 and LprG, as neither alone is sufficient to restore function to the deletion mutant. Thus, P55 requires the cell surface lipoprotein for normal function.
Superconducting states of pure and doped graphene.

We study the superconducting phases of the two-dimensional honeycomb lattice of graphene. We find two spin singlet pairing states; $s$ wave and an exotic $p+ip$ that is possible because of the special structure of the honeycomb lattice. At half filling, the $p+ip$ phase is gapless and superconductivity is a hidden order. We discuss the possibility of a superconducting state in metal coated graphene.
Phosphoinositide signaling and turnover: PtdIns(3)P, a regulator of membrane traffic, is transported to the vacuole and degraded by a process that requires lumenal vacuolar hydrolase activities

The Golgi/endosome-associated Vps34 phosphatidylinositol 3-kinase is essential for the sorting of hydrolases from the Golgi to the vacuole/lysosome. Upon inactivation of a temperature-conditional Vps34 kinase, cellular levels of PtdIns(3)P rapidly decrease and it has been proposed that this decrease is due to the continued turnover of PtdIns(3)P by cytoplasmic phosphatases. Here we show that mutations in VAM3 (vacuolar t-SNARE) and YPT7 (rab GTPase), which are required to direct protein and membrane delivery from prevacuolar endosomal compartments to the vacuole, dramatically increase/stabilize PtdIns(3)P levels in vivo by disrupting its turnover. We find that the majority of the total pool of PtdIns(3)P which has been synthesized, but not PtdIns(4)P, requires transport to the vacuole in order to be turned over. Unexpectedly, strains with impaired vacuolar hydrolase activity accumulate 4- to 5-fold higher PtdIns(3)P levels than wild-type cells, suggesting that lumenal vacuolar lipase and/or phosphatase activities degrade PtdIns(3)P. Because vacuolar hydrolases act in the lumen, PtdIns(3)P is likely to be transferred from the cytoplasmic membrane leaflet where it is synthesized, to the lumen of the vacuole. Interestingly, mutants that stabilize PtdIns(3)P accumulate small uniformly-sized vesicles (40-50 nm) within prevacuolar endosomes (multivesicular bodies) or the vacuole lumen. Based on these and other observations, we propose that PtdIns(3)P is degraded by an unexpected mechanism which involves the sorting of PtdIns(3)P into vesicles generated by invagination of the limiting membrane of the endosome or vacuole, ultimately delivering the phosphoinositide into the lumen of the compartment where it can be degraded by the resident hydrolases.
Laparoscopic ventral hernia repair: primary versus secondary hernias.

Abstract Background Most studies regarding laparoscopic ventral hernia repair (LVHR) have merged primary hernias (PHs) and secondary (incisional) hernias (SHs) into one group of ventral hernias. This grouping could produce falsely favorable results for LVHR. Our objective was to review and compare the outcomes of laparoscopic repair of PHs and SHs. Methods A retrospective chart review of patients from 2000 to 2010 identified the cases of LVHR at two affiliated institutions. The demographics, comorbidities, type of hernia (PH versus SH), and short- and long-term complications were analyzed. The postoperative pain, cosmetic satisfaction, and Activities Assessment Scale scores were assessed by telephone survey. Results A total of 201 cases of LVHR were identified: 73 PHs (36%) and 128 SHs (64%). No difference was found in the mean age between the two groups. The PH group had a greater percentage of black patients (34% versus 14%; P versus 65%; P versus 14%; P versus 66%; P versus 7%; P versus 9%; P 2 versus 11.5 ± 1.9 cm 2 ; P versus 5%; P versus 0%; P versus 1.8 ± 0.4; P versus 5%; P = 0.0003) and had lower satisfaction scores (7.5 ± 0.3 versus 8.6 ± 0.3; P Conclusions Our data have demonstrated that PHs and SHs are different. LVHR of SHs is associated with increased recurrence, greater postoperative pain scores, chronic pain issues, and lower patient satisfaction scores. We recommend that future studies evaluate LVHR for PHs separate from those for SHs.
Might a vanguard of mRNAs prepare cells for the arrival of herpes simplex virus

Sciortino et al. (1) report in a previous issue of PNAS that herpes simplex virus 1 (HSV1) particles contain three RNA-binding proteins. They searched for these proteins to probe the mechanism by which mRNAs are incorporated into herpes virus particles (2–4). As yet, it is not clear whether one of more of these RNA-binding proteins deliver mRNAs to virions, but the identity of one of them led Sciortino et al. to an experiment with an intriguing result. VP22 is the HSV1 RNA-binding protein at issue. It is a major component (≈2,000 copies per virion) of the tegument, a structure residing between the capsid and envelope of herpes virus particles. VP22 has been reported to traffic between cells, transiting the plasma membrane of target cells (5). Sciortino et al. show that VP22 can bind and ferry an mRNA encoding a green fluorescent fusion protein between cells in an RNase-sensitive state, and, importantly, their assay demonstrates that the mRNA is translated within the recipient cell. Directed intercellular transfer of naked mRNA is a new concept in virology. Directed intercellular transfer of naked mRNA is a new concept in virology.
Shift+Design: Scripts and other Design Artifacts

Beyond the debate about the possible advantages of the automation of time-consuming drafting tasks, or of the expressive qualities that emerge from the use of scripts in architectural design, this article posits the idea that scripts constitute a new kind of "design artifact", reconfiguring a designer's engagement with a design problem. By examining how scripts destabilize dominant conceptions of architectural representations as figural descriptions the article delineates the ongoing emergence of a performative and computational epistemology of architectural design.
Constitutive Mutations in the Escherichia coli AraC Protein

The Escherichia coli AraC protein represses and induces the araBAD operon in response to the absence or presence of l-arabinose. Constitutive mutations in the AraC gene no longer require the presence of l-arabinose to convert AraC from its repressing to its inducing state. Such mutations were isolated directly by virtue of their constitutivity or by their resistance to the nonmetabolizable arabinose analog, d-fucose. The majority of the constitutive mutations lie within the same residues of the N-terminal regulatory arm of AraC. Two, however, were found in the core of the dimerization domain. As predicted by the light switch mechanism of AraC, constitutive mutations increase the susceptibility of the N-terminal arms to digestion by trypsin or chymotrypsin, suggesting that these mutations weaken or disrupt the arm structure required for repression by AraC. Fluorescence, circular dichroism, and cysteine reactivity measurements show that the constitutive mutations in the core of the dimerization domain lead to a weakening of the support for the arms and reduce the stability of the minus-arabinose arm structure. These mutations also weaken the interaction between the two-helix bundle and the β-barrel subdomains of the dimerization domain and reduce the structural stability of the β-barrels.
Crystal Structure of Unliganded Influenza B Virus Hemagglutinin

Here we report the crystal structure of hemagglutinin (HA) from influenza B/Hong Kong/8/73 (B/HK) virus determined to 2.8 A. At a sequence identity of ∼25% to influenza A virus HAs, B/HK HA shares a similar overall structure and domain organization. More than two dozen amino acid substitutions on influenza B virus HAs have been identified to cause antigenicity alteration in site-specific mutants, monoclonal antibody escape mutants, or field isolates. Mapping these substitutions on the structure of B/HK HA reveals four major epitopes, the 120 loop, the 150 loop, the 160 loop, and the 190 helix, that are located close in space to form a large, continuous antigenic site. Moreover, a systematic comparison of known HA structures across the entire influenza virus family reveals evolutionarily conserved ionizable residues at all regions along the chain and subunit interfaces. These ionizable residues are likely the structural basis for the pH dependence and sensitivity to ionic strength of influenza HA and hemagglutinin-esterase fusion proteins.
Can Hand‐Carried Ultrasound Devices be Extended for Use by the Noncardiology Medical Community?

Echocardiography (echo) is a powerful, noninvasive, inexpensive diagnostic imaging technique that provides important information in a variety of cardiovascular diseases. Echo provides rapid information regarding ventricular and valvular function in the clinical management of patients. Smaller, relatively inexpensive hand-carried cardiac ultrasound (HCU) devices have become commercially available, which can be used for diagnostic cardiac imaging. Because of their relative ease of use, portability, and affordable cost, these new hand-held systems have made point-of-care (bedside) echocardiography available to all medical personnel. The rate-limiting step to the widespread use of this technology is the lack of personnel with echo training at the immediate contact point with patients. Although extensive training and experience are needed to acquire and interpret a complete echo, training medical personnel to perform and interpret a limited echo (defined as a brief, diagnosis focused exam) may fully exploit the potential of echo as a point-of-care diagnostic tool and may be accomplished in a short period of time. Presently there are guidelines for independent competency in echocardiography and HCU echo established by several professional organizations and as a result of these rigorous guidelines, other noncardiology medical professionals who could practically derive the greatest benefit are discouraged and virtually precluded from utilizing echo during the initial encounter with the patient. However, there is now a growing body of literature in a diverse group of noncardiology medical personnel that demonstrates that it is possible to quickly and effectively train them to perform and interpret limited echocardiograms. Medical students, medical residents, cardiology fellows with limited experience, emergency department physicians, and surgical intensive care unit staff have all been evaluated after only brief, focused training periods, and investigators found that HCU echo provided important new information, changed therapeutic management, and was vastly superior to the physical exam alone with an acceptable overall level of accuracy. The contribution of echocardiography to the field of cardiovascular disease since its invention has been significant and the newer compact, portable, ultrasound systems have the potential to revolutionize the utilization and availability of echocardiography. To maximize integration of echo into medical practice, physicians and physician extenders could be trained to perform and interpret limited echo to complement their clinical examination and improve their diagnostic skills. The challenge is to provide practical training programs to assure competency in performing point of care echocardiograms.
Path-dependent variational effects and multidimensional tunneling in multi-path variational transition state theory: rate constants calculated for the reactions of HO2 with tert-butanol by including all 46 paths for abstraction at C and all six paths for abstraction at O

Multi-path variational transition state theory (MP-VTST) provides a conformationally complete framework for calculating gas-phase rate constants. For reactions in which the transition state has distinguishable torsional minima (which include most reactions), there are multiple possible reaction paths. In principle MP-VTST includes the contributions from all the reaction paths, and it should explicitly treat the variational and tunneling effects of each path, but in practice one may need to truncate the number of paths included in MP-VTST calculations in order to achieve a balance between computational cost and accuracy. In this work, we present calculations including all paths for two prototype combustion reactions, namely the two hydrogen abstraction reactions from tert-butanol by HO2 radical. For both reactions we included all the reaction paths. Since abstraction at C has 46 paths, it provided a good opportunity to carry out a case study in which we investigated the errors introduced by truncating the number of paths. For the reaction studied, we found that the variational and multidimensional tunneling transmission coefficients are very different for different reaction paths, which provides new evidence that MP-VTST is necessary for treating path-dependent variational effects and multidimensional tunneling. We found that tunneling transmission coefficients can be much larger for higher-energy paths than for lower-energy ones. Interestingly, the simple hypothesis that higher barriers are narrower does not explain this finding in the present case; we found instead that the effect is due to higher-energy barriers having the possibility of tunneling at energies farther below the barrier top. We also show that a previously applied criterion for judging convergence with respect to the number of paths may not be reliable at low temperature.
Habitat Associations of Ixodes scapularis (Acari: Ixodidae) in Maine

The habitat associations of Ixodes scapularis Say (=I. dammini Spielman, Clifford, Piesman, and Corwin) were examined at the northern edge of its range. We assessed the association of habitat features with the abundance of ticks by flagging for questing adult I. scapularis at three sites in coastal Maine from 1998 to 2000 along 27 305-m transects. Multivariable logistic regression indicated that probability of tick abundance was greater in the presence of shrub layer, canopy closure >50%, deciduous litter, forest grasses, and moist-soil ferns. In a second model that related I. scapularis abundance to canopy- and shrub-layer species, probability of tick abundance was greater in the presence of Japanese barberry Berberis thunbergii DC, winterberry holly Ilex verticillata L. (Gray), and Eurasian honeysuckle Lonicera spp., and less with the presence of eastern hemlock saplings Tsuga canadensis L. (Carr.). These associations were true despite variation in deer abundance as indicated by deer pellet group counts. Natural resource managers should be aware that landscape changes, including the invasion by exotic vegetation, might create favorable tick habitat. These findings could prove helpful in assessing local risk of exposure to this vector tick.
Fields of Hope, Fields of Despair: Legisprudential and Historic Perspectives on the Agjobs Bill of 2003

In this Article, Professor Lauren Gilbert examines the unique story of the Agricultural Job Opportunity, Benefits and Security Act of 2003 (AgJobs), first in its historical context and then as a case study for applying various legisprudential theories. Professor Gilbert first provides an historic overview of guest-worker programs in America, a detailed analysis of the history of the AgJobs negotiations, and a study of Congressional developments following the bill's introduction in two different Congresses. She follows this with a review of legisprudence literature and a discussion on how the various theories, including pluralism, public choice theory, institutionalist theory, and critical legal theory, while helpful in understanding why AgJobs failed, are each inadequate in explaining the whole story. She then proposes a framework of analysis entitled 'biennial factionalism' to explain how a bill based on an historic alliance between traditional adversaries that enjoyed broad support among legislators in the Senate was still unable to achieve enactment. Professor Gilbert concludes that biennial factionalism, which depends on the dynamic interplay among political and non-governmental actors and the cyclical nature of the legislative process, should give AgJobs advocates reason to be optimistic for eventual success.
Modeling of Fracture in Nano-Particle Reinforced Polymers using the Atomistic J-Integral

In order to better understand the local influence of nano-particle on the mechanical properties of the polymer, nano-scale analysis is necessary. In that context, this paper is directed towards understanding damage initiation and failure progression in advanced nanostructured composite materials using molecular dynamics. The critical value of the Jintegral (JIC) at crack initiation is related to the fracture toughness of the material, where the subscript I denotes the fracture mode (I=1, 2, 3). Therefore, the J-integral could be used as a suitable metric for estimating the crack driving force as well as the fracture toughness of the material as the crack begins to initiate. Further, the conventional isothermal definition of Jintegral does not take into account the entropic contribution to the free energy, and consequently, may lead to significant over-estimation of the J-integral at the atomistic level, especially at finite temperatures. As a case study, the feasibility of computing the dynamic atomistic J-integral over the molecular dynamics (MD) domain at finite temperature is evaluated for a graphene nano-platelet and the values are compared with results from linear elastic fracture mechanics (LEFM) for isothermal crack initiation at 0 K and at 300 K. Jintegral computations are also done using ReaxFF force field in order to simulate bond breakage during crack propagation. Good agreement is observed between the atomistic J and the LEFM results at 0 K, with predictable discrepancies at 300 K due to entropic effects. A novel cohesive-contour based methodology for computing J-integral is discussed and successfully applied to a graphene nano-platelet. Work is currently underway to compute Jintegral for nanographene modified EPON 862 at 0.1 K and 300 K using the cohesive-contour based procedure and to be able to computationally predict fracture toughness. In order to account for the high strain-rates encountered in MD simulations, scaling laws will be developed to correlate fracture toughness predicted by the MD simulations to the toughness data obtained from compact tension fracture experiments.
Separation and Solubility of Cis and Trans Isomers in Nanostructured Double-Decker Silsequioxanes

A fractional crystallization method was used to separate the cis and trans isomers of three double-decker silsesquioxanes (DDSQs) with an aminophenyl moiety in a THF + hexanes solvent mixture. The experimental solubilities were fitted to the Schroder–van Laar equation with activity coefficients determined using the NRTL model by adjusting the binary interaction parameters. The ability to separate these cis and trans isomers was affected by the regioisomer (m- or p-aminophenyl) and the R moiety (cyclohexyl or methyl) coupled via silicon. For a given DDSQ compound, the variances between the solubilities of the cis and trans isomers depend on differences in thermal properties (Schroder–van Laar). Cis isomers were 33 times more soluble than trans isomers for p-aminophenyl (R = methyl) and 22 times more soluble for the analogous m-aminophenyl in a solution of THF and hexanes. For a more sterically hindered m-aminophenyl (R = cyclohexyl), the cis isomers were only 3.5 times more soluble, and the overall solubil...
Experimental Validation of a FEA-Based Model Used for Buckling Analysis of Load Stiffening Bendable UAV Wings

The bendable UAV wing developed by researchers at the University of Florida, is a thin shell structure that has the ability to load stiffen in the positive flight load direction; at the same time being compliant in the opposite direction. Such a unique wing design enables UAV storage in smaller packing volumes. The objective of the research is to develop a buckling prediction model/tool that can numerically model and predict the maximum load carrying capacity of a bendable wing. The paper covers briefly the development of an arc length based finite element routine for modeling the wing in ABAQUS and predicting its load carrying capacity using the snap through buckling under aggressive flight loads as a limit state. For validating buckling prediction model, tests are performed on a range of unswept singly curved composite shell structures and the model predictions are compared with the experimental results obtained by performing three point bend tests on the singly curved wings. A visual image correlation technique is used for full field basis displacement measurement of the singly curved wings. Excellent agreement is found between the experimental buckling load results and the corresponding numerical model predictions. Developed buckling prediction tool can be conveniently used for numerical modeling and buckling velocity prediction for different load stiffening bendable UAV wings.
Three-dimensional vibrations of doubly-skewed, helicoidal, cantilevered thick shells

Riu's first method is applied herein to evaluate the natural frequencies of three-dimensional cantilevered thick shells. Specifically, a generalized geometric transformation is employed for the first time which enables solution for shells having geometric skew about M inplane axes and a helicoidal rotation, or twist, about the longitudinal axis. Including skew about both inplane axes is essential in order to fully capture the dynamic response characteristics of many important cantilevered engineering structures, most notably turbomachinery blades. Model cantilevered thick shell structures are then studied to determine the effects of varying skew and twist angles on their frequencies. Results of numerical studies are compared with finite element analysis results for verification of the method.
Model Based Systems Engineering (MBSE) for Low Cost Spacecraft Operations on IRIS

The Interface Region Imaging Spectrograph (IRIS) mission is a small spacecraft mission currently flying and studying the Sun. The IRIS Mission Operations Team applied Model Based Systems Engineering to the design, development, verification, and validation of the ground systems used to support the testing and operation of the mission. This application of MBSE to mission operations and ground systems for spacecraft was carried through to operations. While MBSE was not used throughout all systems of the IRIS mission, even its application to this one system provided identifiable benefits. Applying the techniques within IRIS mission operations and ground systems was driven by the limited resources of the development phase, both in dollars and in time. The successful launch and operations of the IRIS mission within these constraints demonstrates the benefits in cost and schedule. The MBSE approach provided a mechanism to capture and share designs and interfaces from experienced team members and enable newer team members to become productive more quickly. The resulting system enables operations of this mission with a relatively small team. This paper will describe the approach taken, the benefits realized, and lessons learned within the IRIS mission. Further discussion will include the application of the IRIS mission ground system models to provide similar benefits to future missions.
Assessment of species distributions in Pleurotus based on trapping of airborne basidiospores

A species-specific spore trapping method was employed to detect different species of the oyster mushroom genus Pleurotus from different geographic regions. Monokaryotic tester strains representing five intersterility groups in the P. ostreatus complex were used as spore trap baits. Colonies of each strain were exposed to the outside environment from 24 to 48 hours. Afterward, explants taken from the plates were transferred to fresh media and observed for evidence of dikaryotization. Sets of petri dishes containing all five species were distributed by mail to mycologists at diverse locations in the Northern Hemisphere, where they were placed out for sampling and later returned by mail for scoring. In spite of a relatively high level of contamination, dikaryotization was observed for all five species. The results suggest that spore trapping in this manner can be an effective method for sampling
Secretion of cholesterol by intestinal mucosa in patients with complete common bile duct obstruction.

SummaryIn 3 patients with complete obstruction of biliary and pancreatic ducts cholesterol “secretion” by intestinal mucosa was 250–400 mg/day. Quantification of this function in either man or animals has not been reported previously.
Couching Politics: Zizek's Rules for Radicals

Lacan's theory of the four discourses and recent work by Slavoj Žižek indicate interesting new approaches to integrating politics and psychoanalytic theory. In the end, however, both of these approaches raise more questions than they answer. In particular, Žižek's political strategies fail at crucial points to differentiate themselves from the existentialist ethic of authentic gratuitous acts, from which they derive much of their inspiration as well as rhetorical force. In this paper, I turn to the neglected work of Saul Alinsky for help in adapting the work of Lacan and Žižek in formulating an alternative psychopolitics, which grounds its practices in “Real” political struggles. In particular, abstracting from Alinsky's case studies, I argue that publicity provides the engine that multiplies the effects of individual acts to the point that they take on social effects.