cssi/SciSciGPT-SciSciNet huggingface dataset:
Molecular basis of isoform-specific μ-conotoxin block of cardiac, skeletal muscle, and brain Na+ channels

Abstract μ-Conotoxins (μ-CTXs) block skeletal muscle Na+ channels with an affinity 1–2 orders of magnitude higher than cardiac and brain Na+ channels. Although a number of conserved pore residues are recognized as critical determinants of μ-CTX block, the molecular basis of isoform-specific toxin sensitivity remains unresolved. Sequence comparison of the domain II (DII) S5-S6 loops of rat skeletal muscle (μ1, Nav1.4), human heart (hh1, Nav1.5), and rat brain (rb1, Nav1.1) Na+ channels reveals substantial divergence in their N-terminal S5-P linkers even though the P-S6 and C-terminal P segments are almost identical. We used Nav1.4 as the backbone and systematically converted these DII S5-P isoform variants to the corresponding residues in Nav1.1 and Nav1.5. The Nav1.4→Nav1.5 variant substitutions V724R, C725S, A728S, D730S, and C731S (Nav1.4 numbering) reduced block of Nav1.4 by 4-, 86-, 12-, 185-, and 55-fold respectively, rendering the skeletal muscle isoform more “cardiac-like.” Conversely, an Nav1.5→ Nav1.4 chimeric construct in which the Nav1.4 DII S5-P linker replaces the analogous segment in Nav1.5 showed enhanced μ-CTX block. However, these variant determinants are conserved between Nav1.1 and Nav1.4 and thus cannot explain their different sensitivities to μ-CTX. Comparison of their sequences reveals two variants at Nav1.4 positions 729 and 732: Ser and Asn in Nav1.4 compared with Thr and Lys in Nav1.1, respectively. The double mutation S729T/N732K rendered Nav1.4 more “brain-like” (30-fold↓ in block), and the converse mutation T925S/K928N in Nav1.1 reproduced the high affinity blocking phenotype of Nav1.4. We conclude that the DII S5-P linker, although lying outside the conventional ion-conducting pore, plays a prominent role in μ-CTX binding, thus shaping isoform-specific toxin sensitivity.
Orexin/Hypocretin: Wired for Wakefulness

Orexin neurons play a crucial role in regulating wakefulness and energy metabolism, but until recently, little was known about the factors that influence the activity of these essential cells. Electrophysiological studies have now identified positive and negative feedback signals that allow the orexin neurons to help maintain wakefulness.
The optical absorption edge of brookite TiO2

Abstract The optical absorption edge of brookite TiO2 was measured at room temperature, using natural crystals. The measurements extend up to 3.54 eV in photon energy and 2000 cm−1 in absorption coefficient. The observed absorption edge is broad and extends throughout the visible, quite different from the steep edges of rutile and anatase. No evidence of a direct gap is seen in the range measured. The spectral dependence of the absorption strongly suggests that the brookite form of TiO2 is an indirect-gap semiconductor with a bandgap of about 1.9 eV.
Effects of unilateral prepartum milking on concentrations of immunoglobulin G1 and prolactin in colostrum

Abstract Concentration of IgG 1 in colostrum of Holstein cows is often low at calving. Unilateral prepartum millung was applied twice daily beginning 10 d prepartum to seven dry cows to determine whether premature lactogenesis caused cessation of IgG 1 transfer into secretion. All four quarters were milked twice daily for 3 d postpartum. Samples of blood sera and mammary secretion were collected at each milking and analyzed for IgG 1 , progesterone, and prolactin. Four cows that produced >4 L/d of milk by 4 d prepartum were retrospectively designated as responders. Three cows produced less and were designated as nonresponders. Milk volume was greater for responders than nonresponders from 6 d prepartum through parturition. Concentrations of prolactin and IgG 1 in secretion were lower for responders than nonresponders and for milked than unmilked sides by 6 d prepartum. For responders, cumulative secretions of IgG 1 , milk, and prolactin were higher for milked than unmilked sides. For nonresponders, the trend was similar, but differences were not significant. Cumulative secretion of IgG 1 was higher for nonresponders. Differences between sides indicate that local control is important to the regulation of colostrogenesis. Differences in IgG 1 between response groups indicate that maintenance of transport and dilution are important determinants of IgG 1 concentration in colostrum.
Impact of Canadian wildfire smoke on air quality at two rural sites in NY State

Abstract We report high concentrations of black carbon aerosols (BC), present at two rural sites in New York during the last week in May 2010, that are linked to wildfire activity. At Mayville BC from wood smoke was recorded for a total of 20 h from three separate episodes, mean concentration was 1400 ng m−3. These three short events contributed 13% of the BC burden during the month of May. At Whiteface Mountain high concentrations of BC, carbon monoxide gas (CO), and fine particulate matter mass (PM2.5) are reported from a heavy smoke event that impacted the Adirondack region of the State on May 31, 2010. PM2.5 mass recorded at the Lodge site (600 m above mean sea level) was 150 μg m−3 at 8:30 am EST and the 24-h mean was almost twice the USEPA limits while CO concentration exceeded 1000 ppb and BC concentration reached 9600 ng m−3. The event was delayed several hours at the Summit site (1500 m above mean sea level) but at 5:45 pm BC concentration reached 1600 ng m−3 and CO was 317 ppbv. Detailed temporal profiles and correlations are presented.
How habitat affects the benefits of communication in collectively foraging honey bees

Honey bees (Apis mellifera) use the dance language to symbolically convey information about the location of floral resources from within the nest. To figure out why this unique ability evolved, we need to understand the benefits it offers to the colony. Previous studies have shown that, in fact, the location information in the dance is not always beneficial. We ask, in which ecological habitats do honey bee colonies actually benefit from the dance language, and what is it about those habitats that makes communication useful? In this study, we examine the effects of floral distribution patterns on the benefits of dance communication across five different habitats. In each habitat, we manipulated colonies' ability to communicate and measured their foraging success, while simultaneously characterizing the naturally occurring floral distribution. We find that communication is most beneficial when floral species richness is high and patches contain many flowers. These are ecological features that could have helped shape the evolution of the honey bee dance language.
Uncertainty of Preloads in Closure Bolts for Transportation Casks for Hazardous and Radioactive Materials

Maintaining closure bolting integrity under normal and accident conditions is essential for the safe transportation of shipping casks bearing hazardous and radioactive materials. Bolt preload introduces a clamping force in the joint that plays a critical role in ensuring a less-than-specified rates of leakage from such casks. Precise control over bolt preload is essential to introduce adequate clamping force in the joint. Uncertainty is introduced in the closure bolt preloads when an individual bolt is tightened and then when the other bolts are tightened in a specified sequence. Tightening an individual bolt can introduce uncertainty as high as ±35% mainly because of the variation in the coefficient of friction. Tightening the subsequent bolts in a specified sequence introduces uncertainty because the elastic interactions between bolts reduce the preloads already installed. This paper reviews the literature related to the methods employed for installing the preloads, factors introducing uncertainty in the preloads, methods for reducing the uncertainty, and the techniques available for measuring the preloads. It is concluded that the use of an elastic interaction matrix has a potential for providing the specified preload in the bolted joint and that ultrasonic measurements can be used to monitor the preload with ±10% or less uncertainty.Copyright © 2008 by UChicago Argonne LLC, Operator of Argonne National Laboratory
Devices for sharing thoughts and affection at a distance

Interpersonal communication involves more than just words. Many forms of communication involve physical acts showing warm thoughts and affection, such as giving flowers or displaying photos. Yet these forms of personal communication are difficult at a distance. In this paper, we describe the concept of devices for communicating affection and thoughts from a distance. We detail two devices that we are exploring to support many of these physical interpersonal interactions-an augmented candy dispenser and a digital picture frame-and discuss design issues we have encountered as we investigate this interesting application space.
Four Varieties of Character-Based Virtue Epistemology

The terrain of character-based or “responsibilist” virtue epistemology has evolved dramatically over the last decade — so much so that it is far from clear what, if anything, unifies the various views put forth in this area. In an attempt to bring some clarity to the overall thrust and structure of this movement, I develop a fourfold classification of character-based virtue epistemologies. I also offer a qualified assessment of each approach, defending a certain account of the probable future of this burgeoning subfield.
Dislocation structures of monocrystalline copper in cyclic latent hardening

The dislocation structures of monocrystalline copper, which had first been cycled in single slip and, subsequently, deformed monotonically on another slip system, were studied by transmission electron microscopy (TEM). The purpose of the research was to study the interactions of dislocations on different slip systems with reference to cyclic latent hardening. A special effort was made to observe and analyze the activity of the secondary dislocations and the interaction between the secondary dislocations and preformed structures, such as persistent slip bands (PSBs) walls, loop patches, and labyrinth structures. It was confirmed that the operation of secondary dislocations is a necessary condition for the formation of a persistent slip band from a preexisting loop patch. “Cord” structures were found to result from non-coplanar slip behavior, and their directions were always along the intersecting trace of the active non-coplanar slip plane on the photograph plane. Labyrinth wall structures were found to form only in cyclic deformation by multislip, and the geometry of labyrinth walls was confirmed to be in accordance with the “sweep theory” of Dicksonet al. The magnitude of the plastic strain amplitude applied during the previous cyclic deformation did not affect the latent hardening ratio but was found to strongly affect the strain hardening rate on the latent slip system, consistent with the observation of higher densities of secondary dislocations produced by cycling at amplitudes greater than 2×10–3.
Broad Dissemination of Plasmid-Mediated Quinolone Resistance Genes in Sediments of Two Urban Coastal Wetlands

Contamination of soil and water with antibiotic-resistant bacteria may create reservoirs of antibiotic resistance genes that have the potential to negatively impact future public health through hor...
Hypotension and bradycardia associated with airblock in the neonate: Preliminary report

The hospital courses of 19 infants were analyzed retrospectively to determine if there was a relationship between hypotension and extra-alveolar air: interstitial emphysema, pneumomediastinum, and pneumothorax. Of the 16 infants who subsequently developed PT, 12 had hypotension with IE/PM from one to 86 hours prior to the onset of PT (median 6.5 hours). When compared to blood pressure values obtained before the development of IE/PM, the decrease was statistically significant (p
Megalourethra and urethral diverticula

Megalourethra and urethral diverticula encompass a diverse group of congenital and acquired urethral defects. The appropriate management of these anomalies relies on a keen appreciation of phallic anatomy and an understanding of urethral embryology. A thorough history and physical examination--including a careful evaluation of the urinary tract--is necessary to identify associated congenital anomalies. Finally, satisfactory surgical management demands meticulous attention to surgical technique.
A Newtonian rheological model for the interface of microbubble contrast agents.

Abstract A quantitative model of the dynamics of an encapsulated microbubble contrast agent will be a valuable tool in contrast ultrasound (US). Such a model must have predictive ability for widely varying frequencies and pressure amplitudes. We have developed a new model for contrast agents, and successfully investigated its applicability for a wide range of operating parameters. The encapsulation is modeled as a complex interface of an infinitesimal thickness. A Newtonian rheology with surface viscosities and interfacial tension is assumed for the interface, and a modified Rayleigh–Plesset equation is derived. The rheological parameters (surface tension and surface dilatational viscosity) for a number of contrast agents (Albunex®, Optison® and Quantison®) are determined by matching the linearized model dynamics with experimentally obtained attenuation data. The model behavior for Optison® (surface tension 0.9 N/m and surface dilatational viscosity 0.08 msP) was investigated in detail. Specifically, we have carried out a detailed interrogation of the model, fitted in the linear regime, for its nonlinear prediction. In contrast to existing models, the new model is found to capture the characteristic subharmonic emission of Optison® observed by Shi et al. (1999) . A detailed parametric study of the bubble behavior was executed using the ratio of scattering to attenuation (STAR). It shows that the encapsulation drastically reduces the influence of resonance frequency on scattering cross-section, suggesting possible means of improvement in imaging at off-resonant frequencies. The predictive capability of the present model indicates that it can be used for characterizing different agents and designing new ones. (E-mail: sarkar@me.udel.edu)
Conformation change of cytochrome c. I. Ferrocytochrome c structure refined at 1.5 A resolution.

Abstract Tuna ferrocytochrome c has been crystallographically refined at a resolution of 1.5 A using the Diamond real-space method followed by Jack-Levitt restrained energy and reciprocal space refinement, monitoring progress continuously with superimposed Fourier and difference Fourier maps: The final R factor for cytochrome plus 53 solvent molecules, using 13,840 reflections with intensities greater than 2 σ, is 17·3%. The overall structure remains as described earlier (Takano et al., 1977), but structural details have been clarified to the point where meaningful comparison can be made with the oxidized molecule (following paper). Main and side-chain flexibility as judged by isotropic temperature parameters correlate with position in the molecule, with greatest flexibility at external chain loops. The haem group is held tightly in place by its attachments and neighbours, and is deformed slightly into a saddle shape. The iron does not deviate significantly from the best mean plane of the haem, and bond lengths to ligands are as expected from model compounds. A water molecule buried in the haem crevice is bonded to Asn52, Tyr67 and Thr78, the latter two being bonded also to Met80 and the outer haem propionate. It is proposed that this buried water molecule is involved in the reduction of ferricytochrome c by chromous ion, and the reactions of Tyr67 with KI3 and tetranitromethane. Two other buried water molecules occur beneath the 20's loop at the right, and within the 40's loop at the bottom. Reasonable if tentative functional assignments can be made for all 24 of the evolutionarily invariant residues in the cytochrome molecule.
A flexible tri-axis contact force sensor for tubular medical device applications

A capacitive, tube-shaped tri-axis contact force sensor is fabricated and characterized in this paper. The sensor is inserted into a tubular medical device just like a small section of tube in order to sense the applied contact force on the tip of this tubular device. It comprises two SU-8 plates, wherein the outer and inner rims of the plates with diameters of 2.3 and 1.1 mm, respectively, are assembled together. Three proof masses were hinged to the outer and inner rims of the first plate by membranes. The different signals received from the three electrodes provide collective information indicating the precision and accurate direction of contact forces exerted on the tip of the tubular medical device. In the test, applied force range from 10 mN to 1.0 N was detected, the performance of the sensor is stable from 25 to 65 °C, and the device was functional under a shock of 2.0 N for 10 s in a shock test. In addition, a two-wire readout approach was also developed to minimize the lead wires.
Are attentional dwell times inconsistent with serial visual search

Duncan, Ward, and Shapiro (1994) estimated that attention must remain focused on an object for several hundred milliseconds before being shifted to another object, and they referred to this period as theattentional dwell time. An important implication of these long estimates of the dwell time for models of visual search is that the search process must not involve an item-by-item serial scanning mechanism. If it did, then searching through an array of items would require enormous amounts of time, which—based on data from visual search experiments—it does not. The present report, however, provides evidence that the long estimates of attentional dwell time were caused, at least in part, by the use of masked targets. Implications of these variable estimates of the attentional dwell time for models of visual search are discussed.
The Ext-Algebra of a Representation-Finite Biserial Algebra

Abstract Let Λ be a basic representation-finite biserial finite-dimensional k-algebra. We describe a method for constructing a multiplicative basis and the bound quiver of the Ext-algebra E(Λ) = ∐m ≥ 0 ExtmΛ(Λ/ r , Λ/ r ) of Λ using the Auslander-Reiten quiver of Λ.
Rapid Corticosterone-lnduced Changes in Gene Expression in Rat Hippocampus Display Type II Glucocorticoid Receptor Specificity

Corticosteroids influence a wide range of neuronal activities by binding to either of two different glucocorticoid receptors found in rat brain. To investigate genomic responses in brain to stress levels of circulating corticosterone (CORT), we isolated hippocampal total RNA and poly(A)-containing RNA from rats treated with 10 mg/day CORT or vehicle. RNA translation products were resolved by 2-dimensional gel electrophoresis and fluorography. Select changes in four translation products after acute CORT treatment were inferred from up to 100-fold increases in three polypeptides and a 2-fold decrease in another. While adrenalectomy decreased levels of the inducible RNA sequences (adrenalectomized vs. intact controls), CORT increased the inducible sequences above their levels in intact controls. Rapid increases within 2 h of CORT treatment were seen for RNAs coding for 35, 33, and 20 kilodalton polypeptides. However, RNA coding for a 50 kilodalton polypeptide had a delayed decrease, first seen after 32 h COR...
Effect of the chest wall on breast lesion reconstruction

The chest wall underneath the breast tissue affects near-infrared (NIR) diffusive waves measured with reflection geometry. With the assistance of a co-registered ultrasound, the depth and the tilting angle of the chest wall can be determined and are used to model the breast as a two-layer medium. Finite element method (FEM) is suitable for modeling complex boundary conditions and is adapted to model the breast tissue and chest wall. Four parameters of bulk absorption and reduced scattering coefficients of these two layers are estimated and used for imaging reconstruction. Using a two-layer model, we have systematically investigated the effect of the chest wall on breast lesion reconstruction. Results have shown that chest-wall depth, titling angle, and difference between optical properties of two layers of lesion and reference sites affect the lesion reconstruction differently. Our analysis will be valuable and informative to researchers who are using reflectance geometry for breast imaging. The analysis can also provide guidelines for imaging operators to minimize image artifacts and to produce the best reconstruction results.
Raising Awareness of Assistive Technology in Older Adults Through a Community-Based, Cooperative Extension Program

The Fashion an Easier Lifestyle with Assistive Technology (FELAT) curriculum was developed as a needs-based, community educational program provided through a state Cooperative Extension Service. The overall goal for participants was to raise awareness of assistive technology. Program evaluation included a postassessment and subsequent interview to determine short-term knowledge gain and longer term behavior change. The sample consisted of mainly older, married females. The FELAT program was effective at raising awareness and increasing knowledge of assistive technology, and for many participants, the program acted as a catalyst for planning to or taking action related to assistive technology.
Leg Stiffness and Articulated Leg Design for Dynamic Locomotion

A number of legged robots capable of dynamic running have been constructed, although, in most cases, very little explanation has been given for how the stiffness of the legs was selected. This paper proposes that a reasonable design value for a robot’s leg stiffness is the effective leg stiffness of an animal having the same mass. It further details a simple, kinetostatic analysis of articulated legs that can be used to determine the leg design geometry for a desired stiffness. The technique allows the designer to exploit the non-linearities in the leg mechanism to achieve an advantageous non-linear leg stiffness. An example of the method is given, and preliminary experimental results with the corresponding prototype leg are presented.Copyright © 2002 by ASME
Encouraging teachers to encourage children's curiosity a pivotal competence

Abstract Cowen (1977) advocates that we select primary preventa‐tive interventions which either modify “impactful”; social systems and/or provide training in “pivotal”; competencies. He specifically notes that “the area of children's question‐asking behavior in class holds special interest because it can potentially wed the social systems and competence approaches … there is evidence linking curiosity behavior directly to good adjustment”; (p. 14). This paper describes an approach to foster children's competency in question‐asking by providing competence training in questioning to their teachers. Previous research had indicated that children rarely ask questions in school, whereas teachers typically emit predominantly rote memory questions, at rates of 1–3 questions per minute (see Gall, 1971, and Susskind, 1969).
67 Patterns of reproduction and morphological variation in southern california populations of the lower intertidal kelp egregia menziesii (turner) areschoug

Egregia menziesii is a complex kelp with an adult morphology that varies considerably across its geographic range. Fertility in Egregia also varies geographically. We studied intertidal populations of Egregia at three southern California sites to determine spatial and temporal patterns of reproduction, recruit-qment, and morphology. Growing axes of Egregia were collected monthly to quantify sporophyll production and lateral blade morphology. Band transects were surveyed quarterly (2001) and monthly (2002) to determine temporal patterns of sporophyte recruitment. Sporophylls were found throughout the year, but sporophyll densities showed a strong peak during winter periods of colder seawater temperatures and shorter daylengths. Sporophytes recruited almost exclusively from March to July, suggesting a gametophyte period of <5 months. Lateral blade morphologies varied in a consistent pattern; thalli initially developed spatulate blades but then produced increasing numbers of filiform laterals as axes grew. Thalli in habitats populated by higher grazer densities had shorter axes, dominated by spatulate blades, while those growing under low grazing pressure exhibited longer fronds and more filiform laterals. Differences in lateral morphology had effects on thallus productivity and susceptibility to grazers. Filiform laterals had higher light-saturated photosynthetic rates than spatulate laterals and a 1-m long frond with filiform laterals was estimated to be 12% more productive than one with spatulate laterals. Kelp snails, but not urchins, consistently chose spatulate over filiform laterals, this suggests that Egregia thalli dominated by spatulate laterals are more susceptible to grazing molluscs, while lateral morphology has no effect on Egregia's susceptibility to urchins.
Isolation and characterization of the recA gene of Bordetella pertussis.

Summary This report describes the detection and cloning of the Bordetella pertussis recA gene. Escherichia coli clones having recombinant plasmids containing the B. pertussis recA gene were isolated by complementing an E. coli RecA− mutant's inability to survive in the presence of methylmethanesulphonate (MMS). This gene was shown to complement the deficiency of E. coli RecA− strains to tolerate the DNA-damaging effects of both a chemical agent and ultraviolet light (u.v.). Deletion mapping experiments localized the gene to a 2.5kb Stul-EcoRI fragment, and expression of the gene in E. coli resulted in the production of a 40kD protein. These data strongly suggest that a region of the B. pertussis chromosome that encodes RecA-like activity has been isolated and cloned.
Cascade Semiconductor Lasers for Telecommunications

This paper explores the development of cascade semiconductor lasers for communications applications. Both interband and intersubband cascade emission devices are examined theoretically and experimentally. The motivation for cascade sources in both high fidelity and high bandwidth applications is presented. The ability to transmit signals with lower signal loss and improved noise performance is verified by measurements on a model systems consisting of series coupled DFB lasers.
Utility of the Lateral Chest Radiograph in the Evaluation of Patients With a Positive Tuberculin Skin Test Result

Study objectives In the United States, chest radiographs are performed on patients with positive tuberculin skin test (TST) results. It is not known whether, in addition to a single posteroanterior radiograph, a lateral chest radiograph is clinically indicated or cost-effective. We sought to determine the utility of the lateral chest radiograph in evaluating TST-positive adults. Design Cross-sectional study. Setting Tertiary-care hospital. Patients Adults with positive TST results. Mreasurements Findings on posteroanterior radiographs alone were compared to posteroanterior and lateral chest radiographs. Results In 2 of 535 cases (0.4%), lateral chest radiographs revealed a calcified granuloma not visible on posteroanterior radiographs. This finding did not alter patient management. In all other cases, lateral radiographs only confirmed findings seen on posteroanterior chest radiographs. Conclusion Treatment altering findings were always visible on posteroanterior radiographs alone. These results suggest that lateral chest radiographs are not useful in evaluating adults with positive TST results.
Evidence for a preferential loss of enkephalin immunoreactivity in the external globus pallidus in low grade Huntington's disease using high resolution image analysis

Abstract Previous studies have shown that in advanced cases of Huntington's disease, enkephalin-immunoreactive striatal projections to the external globus pallidus may be more affected than substance P-containing striatal projections to the inner segment of the pallidum [Reiner A. et al. (1988) Proc. natn. Acad. Sci. U.S.A. , 85 , 5733–5737]. Other immunohistochemical [Ferrante R. J. et al. (1990) Soc. Neurosci. Abstr. , 16 , 1120] and neurochemical observations [Storey E. and Beal M. F. (1993) Brain , 116 , 1201–1222] suggest no difference in the loss of these peptide-containing pathways in Huntington's disease. In view of the potential significance of this issue for understanding the neuropathological process in Huntington's diseasem we examined the globus pallidus in control and Huntington's disease brains, using a quantitative approach which involved high resolution image analysis of 7 μm frozen sections to determine the overall density of peptide-immunoreactive terminals. Results showed that in the controls there was no significant difference between the density of enkephalin- and substance P-immunoreactive terminals in the external and internal globus pallidus, respectively. In all Huntington's disease brains, including grade 1 cases, enkephalin-immunoreactive terminals in the external globus pallidus were significantly reduced compared to substance P-positive boutons in the internal segment of the adjacent section. In comparison to controls, enkephalin immunoreactivity in all Huntington's disease cases was significantly lower; substance P-immunoreactive terminals in the internal globus pallidus were significantly lower than controls in some of the grade 2 cases and in the grade 3 cases. Our results using a method of analysis different from previous studies support the earlier findings of Reiner et al. , that in Huntington's disease the striatopallidal pathway containing immunoreactive enkephalin is affected to a greater extent than the projection containing substance P. Moreover, the additional finding in this study that enekephalin and substance P projections differ markedly in the grade 1 cases strongly suggests that the alterations in the enkephalin pathway signal a relatively early event in the neuropathological process in Huntington's disease.
Atomically thin optoelectronics: the ideal semi-metal and the insurmountable insulator (presentation video)

Graphene, an atomically thin sheet of hexagonally oriented carbon, is a zero band gap semi-metal that exhibits extraordinary electronic and optical behavior. Hexagonal boron nitride, which shares a similar structure to that of graphene, is an insulator that does not absorb any light in the visible spectrum. By combining graphene and boron nitride into ultrathin vertical stacks, we fabricated new optoelectronic devices that demonstrate highly sensitive optical response, yet are only several nanometers thick. In this talk, I will discuss how stacking these atomically thin materials allows us to explore new types of optoelectronic devices that reveal a novel hot carrier transport regime, which may lead to more efficient energy harvesting technologies.
A test for measuring recognition and naming of landmarks.

There have been considerable gains in recent years in understanding cognitive and neural correlates for retrieval of various types of knowledge, such as the meanings and lexical forms for categories such as familiar faces, animals and tools, and actions. An important category that has been largely neglected so far is landmarks, and one likely reason for this is a lack of suitable stimulus materials. Here, we report a study in which we designed a Landmark Recognition and Naming Test. The test contains 65 natural (e.g., “Old Faithful”) and artifactual (e.g., “U.S. Capitol”) landmarks from around the world. Preliminary recognition and naming data were collected from 68 normal participants (37 female). We also obtained data about the participants (e.g., educational level, participants’ experience traveling to national parks), the stimuli (e.g., visual complexity, image agreement), and participant-stimulus interactions (e.g., familiarity, age of acquisition), and analyzed how such factors influenced landmark r...
Protocol for Acute and Chronic Sinusitis

Abstract Formal protocols for nurse practitioners are mandated by many states. Protocols are of two types-processoriented, which describe the steps used in treating patients, and disease-oriented, which define disease, explain etiology, and describe the plan of care, among other things. The sinus protocol outlined in this article is used in the UCLA student health service. It is disease oriented and focuses on college students, but it can also be adapted to use in a different setting.
Is the Higgs(INO) color triplet light

Abstract We explore the possibility that the Higgs triplet partners of the electroweak breaking doublets might be light (≲TeV), and show how this idea might be implemented. We conclude that supersymmetry is essential and that some Yukawa couplings and Higgs masses must be equal at or near unification. These identities are guaranteed in theories where each family has its own gauge group.
Doxorubicin physical state in solution and inside liposomes loaded via a pH gradient

We have examined doxorubicin's (DOX) physical state in solution and inside EPC/cholesterol liposomes that were loaded via a transmembrane pH gradient. Using cryogenic electron microscopy (cryo-EM) we noted that DOX loaded to 200-300 mM internal concentrations in citrate containing liposomes formed linear, curved, and circular bundles of fibers with no significant interaction/perturbation of the vesicle membrane. The individual DOX fibers are putatively comprised of stacked DOX molecules. From end-on views of bundles of fibers it appeared that they are aligned longitudinally in a hexagonal array with a separation between fibers of approx. 3-3.5 nm. Two distinct small angle X-ray diffraction patterns (oblique and simple hexagonal) were observed for DOX-citrate fiber aggregates that had been concentrated from solution at either pH 4 or 5. The doxorubicin fibers were also present in citrate liposomes loaded with only one-tenth the amount of doxorubicin used above (approx. 20 mM internal DOX concentration) indicating that the threshold concentration at which these structures form is relatively low. In fact, from cryo-EM and circular dichroism spectra, we estimate that the DOX-citrate fiber bundles can account for the vast majority (>99%) of DOX loaded via a pH gradient into citrate buffered liposomes. DOX loaded into liposomes containing lactobionic acid (LBA), a monoanionic buffer to control the internal pH, remained disaggregated at internal DOX concentrations of approx. 20 mM but formed uncondensed fibers (no bundles) when the internal DOX concentration was approx. 200 mM. This finding suggests that in the citrate containing liposomes the citrate multianion electrostatically bridged adjacent fibers to form the observed bundles. 13C-NMR measurements of [1,5-13C]citrate inside liposomes suggested that citrate 'bound' to the DOX complex and 'free' citrate rapidly exchange indicating that the citrate-DOX interaction is quite dynamic. DOX release into buffer was relatively slow (<4% at 1 h) from liposomes containing DOX fibers (in citrate loaded to a low or high DOX concentration or in LBA liposomes loaded to a high internal DOX concentration). LBA containing liposomes loaded with disaggregated DOX, where the internal DOX concentration was only approx. 20 mM, experienced an osmotic stress induced vesicle rupture with as much as 18% DOX leakage in less than 10 min. The possible implications for this in vivo are discussed.
Imagining risk, care and security: Insurance and fantasy

This article envisions insurance through the ways in which it comes to inhabit the dailiness of people's lives. Insurance is usually constituted as a technology of risk. Rather than holding risk and insurance to the bare provisions of finance and financial forms, this article tangles with the affective attachments that grow out of insurance technologies. It investigates the place of these attachments (insurance fantasies) and the intimacies that effloresce from these attachments.
Syntheses, structures, physical properties, and electronic structures of KLn2CuS4 (Ln=Y, Nd, Sm, Tb, Ho) and K2Ln4Cu4S9 (Ln=Dy, Ho)

Abstract Seven new quaternary metal sulfides, KY 2 CuS 4 , KNd 2 CuS 4 , KSm 2 CuS 4 , KTb 2 CuS 4 , KHo 2 CuS 4 , K 2 Dy 4 Cu 4 S 9 , and K 2 Ho 4 Cu 4 S 9 , were prepared by the reactive flux method. All crystallographic data were collected at 153 K. The isostructural compounds K Ln 2 CuS 4 ( Ln =Y, Nd, Sm, Tb, Ho) crystallize in space group Cmcm of the orthorhombic system with four formula units in cells of dimensions ( Ln , a , b , c (A)): Y, 3.9475(9), 13.345(3), 13.668(3); Nd, 4.0577(3), 13.7442(10), 13.9265(10); Sm, 4.0218(4), 13.6074(14), 13.8264(14); Tb, 3.9679(5), 13.4243(17), 13.7102(18); Ho, 3.9378(3), 13.3330(11), 13.6487(11). The corresponding R 1 indices for the refined structures are 0.0197, 0.0153, 0.0158, 0.0181, and 0.0178. The isostructural compounds K 2 Dy 4 Cu 4 S 9 and K 2 Ho 4 Cu 4 S 9 crystallize in space group C 2/ m of the monoclinic system with two formula units in cells of dimensions ( Ln , a , b , c (A), β (°)): Dy, 13.7061(13), 3.9482(4), 15.8111(15), 109.723(1); Ho, 13.6760(14), 3.9360(4), 15.7950 (16), 109.666(2). The corresponding R 1 indices are 0.0312 and 0.0207. Both structure types are closely related three-dimensional tunnel structures. The tunnels are filled with bicapped trigonal-prismatically coordinated K atoms. Their anionic frameworks are built from Ln S 6 octahedra and CuS 4 tetrahedra. K Ln 2 CuS 4 contains ∞ 1 [CuS 3 5− ] chains of vertex-sharing tetrahedra and K 2 Ln 4 Cu 4 S 9 contains ∞ 1 [Cu 4 S 8 12− ] chains of tetrahedra. K 2 Ho 4 Cu 4 S 9 shows Curie–Weiss paramagnetic behavior between 5 and 300 K, and has an effective magnetic moment of 10.71 μ B for Ho 3+ at 293 K. Optical band gaps of 2.17 eV for KSm 2 CuS 4 and 2.43 eV for K 2 Ho 4 Cu 4 S 9 were deduced from diffuse reflectance spectra. A first-principles calculation of the density of states and the frequency-dependent optical conductivity was performed on KSm 2 CuS 4 . The calculated band gap of 2.1 eV is in good agreement with the experimental value.
Risky Rivers: The Economics and Politics of Floodplain Farming in Amazonia

Risky Rivers: The Economics and Politics of Floodplain Farming in Amazonia. MICHAEL CHIBNIK. Tucson: University of Arizona Press, 1994. xx + 267 pp., figures, tables, appendix, glossary, references, index.
Glycine prevents the phenotypic expression of streptococcal glucan-binding lectin.

Abstract Glycine has been used extensively in bacterial cell surface research. Some researchers employ glycine in growth media so as to increase the transformability of streptococci during electroporation. Others have found that glycine, similar to wall antibiotics, ‘weakens’ peptidoglycan. It is now shown that when glycine is incorporated into the growth medium, Streptococcus sobrinus exhibits a diminished ability to aggregate with high molecular weight α-1,6-glucan. Growth of the bacteria in either a rich or a chemically defined medium results in a cell population with full lectin (glucan-binding) fidelity. Incorporation of glycine, but not serine or other amino acids, at concentrations of 100–200 mM gives rise to bacteria with lowered lectin activities. Bacteriolytic enzymes were able to lyse bacteria from glycine-grown cultures more readily than from cultures without the glycine supplement. The bacteria produce glucan-binding proteins, including glucosyltransferases, but they do not readily aggregate with added dextran. Furthermore, SDS-PAGE gels of supernatants of growth media (±glycine) are similar, suggesting the bacteria do not produce a unique set of proteins. Western blotting with a fluorescein isothiocyanate-labeled dextran probe reveals normal amounts of glucan-binding proteins in glycine-grown streptococci. Glycine may be acting as a type of antibiotic, reducing wall integrity upon which glucan promoted cellular aggregation depends.
Evidence for a catalytic role for thyroid peroxidase in the conversion of diiodotyrosine to thyroxine.

When thyroglobulin and other proteins are incubated with iodide in the presence of purified thyroid peroxidase and glucose plus glucose oxidase, the iodotyrosines MIT and DIT are formed by iodination of tyrosyl residues, and significant amounts of T4 are also produced. Formation of T4 is greatest when goiter thyroglobulin is the iodine acceptor. The present study was designed to determine whether thyroid peroxidase plays a catalytic role in the coupling reaction to form T4, or whether it serves only to form the precursor of T4, diiodotyrosine, which might then couple non-enzymatically to form T4. Two lines of evidence are presented in support of the view that thyroid peroxidase plays a role in T4 formation beyond that of simply providing the DIT precursor for the coupling reaction. In one group of experiments, thyroglobulin, casein, and fibrinogen were iodinated chemically with molecular iodine and enzymatically with thyroid peroxidase. At any given level of iodination the number of DIT and MIT residues p...
Steric Exclusion of Salts by Polyethylene Glycol

Abstract The solubility of salt in water decreases in the presence of a water soluble polymer, polyethylene glycol (PEG), and could be expressed by a linear relationship between the logarithm of the solubility of salt (M) and the concentration of PEG (M). The slope of the solubility lines was in agreement with the excluded volume of PEG calculated with the rod-like model of PEG. The solubility limit of each salt in the PEG-free solvent (solvent unoccupied by PEG) remained constant regardless of the concentration of PEG. Therefore, the solubility of salt in PEG solutions may be described by the excluded volume effects of PEG. This suggests that PEG sterically excludes salt, thus salt is concentrated in the accessible solvent up to the solubility limit.
The Envelope Proteins from Purified Respiratory Syncytial Virus Protect Mice from Intranasal Virus Challenge

AbstractA lyophilized subunit vaccine prepared from purified respiratory syncytial virus, which contained the envelope glycoproteins F and G and the nonglycosylated matrix protein VPM, was tested in SJL mice for its ability to protect the lungs of mice from intranasal viral challenge. Initially, the mice were injected subcutaneously with one, two, or three doses of 5 or 25 μg of vaccine in 50% complete Freund's adjuvant or with complete Freund's adjuvant or phosphate-buffered saline only. Although none of the mice produced neutralizing serum antibody, three doses of 25 μg elicited antibodies to F, G, and VPM. Despite the absence of detectable neutralizing antibodies, the lungs of 93% of the vaccinated mice were protected from intranasal viral challenge. Because the initial protocol did not elicit neutralizing antibodies and a few single-dose animals were not protected, a second vaccine trial was carried out. For these studies the priming dose was increased to 50 μg, which was followed, in half the vaccine...
Sinus Surgery: Does Mitomycin C Reduce Stenosis?

This experimental study investigates the effect of mitomycin C (MMC) on sinus mucosal healing. MMC has an antiproliferative action on fibroblasts. It is used in glaucoma surgery to prevent restenosis of fistulas. Antrostomies were drilled in rabbit maxillary sinuses. One side was used as a control and the other treated with MMC at a concentration of 0.04, 0.4, or 1 mg/mL. Two animals from each group were sacrificed at 1, 2, 4, and 12 weeks. The antrostomies in the control and 0.04-mg/mL groups had closed by 1 week; in the 0.4-mg/mL group by 4 weeks, and in the 1.0-mg/mL group by 12 weeks. Ciliary function was initially impaired but normalized within 1 week. Both light and scanning electron microscopy showed no permanent damage to the cilia. These results suggest that MMC can be used to delay closure of antrostomies in sinus surgery.
Parameterization and analysis of the optical absorption and scattering coefficients in a western Norwegian fjord: a case II water study

Based on statistical analyses of optical properties measured during a whole year of monthly cruises in a Norwegian fjord, we constructed a two-component model for the absorption and scattering coefficients for visible light. The input to the model is the concentrations of yellow substance and chlorophyll a. Because of the presence of a significant amount of nonalgal particles in coastal water, we assume that the absorption and scattering coefficients approach constant background values when the concentration of chlorophyll a approaches zero. The model works reasonably for a variety of optical conditions encountered throughout the year, with a possible exception during a bloom of the Emiliania huxleyi algae in June.
The Effects of Various Ions on Enamel Solubility

Several reports in the literature indicate that the solubility of enamel in acids can be changed by the action of various ions. Miller (1) using silver nitrate was unable to show retardation in enamel decalcification. The research work of Rickert (2) contradicted this and led him to believe that increased resistance to decalcification of silver nitrate-treated enamel was due to the clogging of tooth substance with reduced silver which prevented the penetration of acids. Hill and Arnold (3) studied the effects of silver nitrate on powdered enamel and found that after treatment, the solubility of enamel was significantly reduced. Difference in enamel solubility in acetate and maleate buffers was attributed by Benedict and Kanthak (4) to the formation of calcium maleate which acted as a protective coating over the enamel particles. Volker (5) and Bibby (6) investigated the effect of fluorides on enamel and concluded that the fluorine ion produced marked reduction in solubility. Because little or no consideration has been given to the effects of other ions on the solubility of enamel, it seemed to us worthwhile to investigate the matter. The choice of the ions used in the experiments was determined by a consideration of the mechanisms whereby the phenomenon of reduced solubility might occur. In order to better understand these, an examination of the chemical nature of enamel is necessary. This will be limited to facts relevant to the adequate understanding of certain assumptions which are made in this paper. Tooth enamel is a crystalline substance showing a characteristic x-ray diffraction pattern. Moreover, this pattern is practically identical with that given by bone, dentin and certain synthetic or natural inorganic materials, such as fluorapatite. On the basis of these x-ray findings these substances have been included in the general class of apatites. It should be remembered that this apatite classification refers only to a particular atomic pattern or arrangement in the crystal lattice and not to any constancy of chemical composition. For instance, McConnell (7, 8) has pointed out that a large number of substitutions are possible in the general apatite pattern. If X10(ZO4)6. (F20H2C12) represents the general formula for the apatites, then X may be calcium, lead, manganese, potassium, strontium and cesium or in lesser amounts yttrium, lanthanum, titanium, iron, aluminum and magnesium; Z may be chromium, phosphorous, arsenic, vanadium, silicon, and carbon. Further evidence of the complex and variable nature of the apatites is obtained from the work of Eisenberger, Lehrman and Turner (9). In their critical review of the literature on the system
Effect of castration on the induction of epidermal neoplasms in male mice by topical methylcholanthrene.

Fifty normal (sham operated) and 48 castrated male Swiss mice were painted with methylcholanthrene solution for 16 weeks resulting in warty papules and squamous cell carcinomas. A comparison was made between the two groups as to the median neoplastic surface area involved, the number of mice developing papules of at least 2mm in diameter, and the mean number of tumors per mouse. The castrated group had lower values for all three comparisons, although only the comparison of numbers of mice developing papules was statistically significant (P