cssi/SciSciGPT-SciSciNet huggingface dataset:
Schwann cells: origins and role in axonal maintenance and regeneration.

The Schwann cell plays a vital role in maintaining the peripheral nervous system (PNS). Schwann cells are derived from neural crest cells, and come in two types either myelinating or non-myelinating Schwann cells. Both play a pivotal role in the maintenance and regeneration of axons of the neurons in the PNS. The regulation of Schwann cells is mediated a number of different neurotrophic factors which signal to transcription factors such as Krox-20, Oct-6 and Sox-10. Schwann cells are affected in a number of demyelinating disorders, such as Charcot-Marie-Tooth disease and Guillain-Barre Syndrome, infected by Mycobacterium leprae to cause leprosy and are responsible for the tumors seen in patients with neurofibromatosis type 1 and neurofibromatosis type 2. The Schwann cell is under investigation as a therapeutic agent for demyelinating diseases and spinal cord injuries. Further research on Schwann cells will help understand these diseases and perhaps lead to new treatments.
Social Psychology: American Indians, science and technology

The status of technological and scientific skill attainment by American Indian individuals and the science- and technology-related issues faced by Indian communities and cultures are outlined. The ...
Self-eating with your fingers

Macroautophagy (hereafter autophagy) is a primarily degradative pathway that plays critical roles in cellular homeostasis 1. The morphological and functional hallmark of autophagy is the double-membrane autophagosome, a sequestering compartment that is derived from the phagophore. One of the key components of the protein machinery that drives autophagy is BECN1, the product of the BECN1 gene and the homolog of yeast Vps30/Atg6. There are two phosphatidylinositol 3-kinase (PtdIns3K) complexes in yeast, both of which contain the PtdIns3K Vps34, the presumed regulatory subunit Vps15, and Vps30/Atg6 2. Complex I also includes Atg14, and is specific to autophagy, whereas this component is replaced in complex II by Vps38, which functions in endosomal trafficking. BECN1 is part of at least three class III PtdIns3K complexes in mammals 3 that also include the PtdIns3K PIK3C3/VPS34, PIK3R4/VPS15, and different combinations of ATG14/ATG14L/BARKOR, UVRAG, AMBRA1 and/or KIAA0226/RUBICON. The ATG14-containing complex acts at an early stage of autophagosome formation, whereas UVRAG (which binds BECN1 at the same domain) directs the complex to act at a later stage of autophagosome maturation and also participates in endocytic trafficking. KIAA0226/RUBICON localizes the PtdIns3K complex to late endosomes/lysosomes and acts to inhibit autophagy. The PtdIns3K complex plays a critical role in autophagy by synthesizing PtdIns3P, a phosphoinositide that recruits certain autophagy-related (ATG) proteins to the site of phagophore formation. BECN1 in particular has been the subject of much research, stemming in part from its identification as a tumor suppressor that is mutated in several human cancers. In addition to its autophagic function as a component of the PtdIns3K complex, BECN1 is connected to the apoptosis pathways via its ability to bind to antiapoptotic factors such as BCL2, BCL2L1/Bcl-XL and related proteins. A critical point regarding its function is that BECN1, along with AMBRA1 4, may act as part of a balance point that controls the cellular response to stress, dictating whether the outcome is cytoprotective or results in cell death; for example, the BCL2-BECN1 complex inhibits autophagy and favors apoptosis. Accordingly, several regulatory molecules modulate autophagy through posttranslational modification of BECN1 or BCL2, including DAPK1 5 and MAPK8/JNK1 6. Furthermore, BECN1 may also contribute to apoptosis following caspase cleavage and mitochondrial translocation 7, whereas the endoplasmic reticulum-localized population of BECN1 is involved in promoting autophagy 8.
Crown ether derivatives of anthraquinone as ionophores in ion‐selective electrodes

1,8-anthraquinono-18-crown-6 and 10-[(2,4-dinitrophenyl)azo]-9-hydroxy-1,8-anthraceno-18-crown-6 were prepared from 1, 8-dichloroanthraquinone and used in the development of ion-selective electrodes. The electrodes based on 10-[(2,4-dinitrophenyl)azo]-9-hydroxy-1,8-anthraceno-18-crown-6 displayed better selectivity for potassium over sodium and had fewer interferences. The differences and similarities between the ionophores, as well as the optimum conditions for the preparation of the electrodes are discussed.
Low-loss semiconductor waveguide bends

An experimental comparison is made between the losses of waveguide bends in disorder-delineated waveguides in semiconductor superlattices composed of GaAs and AlAs layers for simple abrupt bends and abrupt bends with an additional half-angle guiding wall proposed by Shiina et al. [Opt. Lett. 11, 736 (1986)]. For light above the band gap of bulk GaAs, the abrupt and Shiina bends were found to have to 3-dB loss angles of 3 and 7 deg, respectively. This improved performance suggests that the specific geometry of the bends is yet another degree of freedom in designing guiding structure for planar routing.
The influence of hydrous Mn–Zn oxides on diel cycling of Zn in an alkaline stream draining abandoned mine lands

Abstract Many mining-impacted streams in western Montana with pH near or above neutrality display large (up to 500%) diel cycles in dissolved Zn concentrations. The streams in question typically contain boulders coated with a thin biofilm, as well as black mineral crusts composed of hydrous Mn–Zn oxides. Laboratory mesocosm experiments simulating diel behavior in High Ore Creek (one of the Montana streams with particularly high Zn concentrations) show that the Zn cycles are not caused by 24-h changes in streamflow or hyporheic exchange, but rather to reversible in-stream processes that are driven by the solar cycle and its attendant influence on pH and water temperature ( T ). Laboratory experiments using natural Mn–Zn precipitates from the creek show that the mobilities of Zn and Mn increase nearly an order of magnitude for each unit decrease in pH, and decrease 2.4-fold for an increase in T from 5 to 20 °C. The response of dissolved metal concentration to small changes in either pH or T was rapid and reversible, and dissolved Zn concentrations were roughly an order of magnitude higher than Mn. These observations are best explained by sorption of Zn 2+ and Mn 2+ onto the secondary Mn–Zn oxide surfaces. From the T -dependence of residual metal concentrations in solution, approximate adsorption enthalpies of +50 kJ/mol (Zn) and +46 kJ/mol (Mn) were obtained, which are within the range of enthalpy values reported in the literature for sorption of divalent metal cations onto hydrous metal oxides. Using the derived pH- and T -dependencies from the experiments, good agreement is shown between predicted and observed diel Zn cycles for several historical data sets collected from High Ore Creek.
Biochemical and autoradiographic analysis of regeneration in two hydroids

Podocoryne carnea and Hydractinia echinata are organisms at a similar taxonomic level with different regenerative abilities. This investigation compared biochemical events following wounding of these organisms, and additionally examined autoradiographically the incorporation of macromolecular precursors into cells in the cut, proximal area of their gastrozooids. Although the non-regenerating gastrozooids of both organisms incorporated little 3H-thymidine into cells near the proximal tip, amputation provided a stimulus for cells in this area of both organisms to incorporate greater levels of this precursor. However, the level of stimulation of total incorporation into gastrozooids was substantially greater in Podocoryne. During regeneration, Podocoryne gastrozooids were stimulated to incorporate peak levels of 3H-uridine into RNA at 6, 15 and 24 hours, whereas Hydractinia gastrozooids exhibited no peak levels of incorporation throughout the 27-hour post-wounding period. In the initial nine hours following wounding, Podocoryne gastrozooids were stimulated to much greater levels of incorporation of 3H-leucine into protein over non-regenerating gastrozooids than were Hydractinia polyps. Therefore, the results of this biochemical and autoradiographical investigation demonstrated that Podocoryne gastrozooids, which regenerate proximally, had substantially higher levels of stimulation of precursor incorporation into macromolecules during 27 hours following wounding than Hydractinia gastrozooids, which do not regenerate proximally. Additionally, when this level of incorporation was depressed by the use of inhibitors in Podocoryne polyps, they were unable to complete regeneration in the normal manner.
Investigating a possible cause of mesh migration during totally extraperitoneal (TEP) repair.

In experienced hands, laparoscopic inguinal hernia repair has a low rate of recurrence, but it still can recur, and a number of reasons for this have been identified. In published studies, the majority of such cases seem to result from inadequate dissection leading to missed hernias or suboptimal mesh placement. But even with adequate dissection and proper placement of a sufficiently large mesh, recurrence sometimes happens. A number of investigators have cited mesh migration or dislocation as a possible cause, and this study examined how hip flexion affects the position of newly placed meshes and staples in totally extraperitoneal (TEP) repair of inguinal hernia. After completion of the dissection and reduction of discovered hernias, a 15 × 15-cm polypropylene mesh was placed either unilaterally or bilaterally, as indicated. The preperitoneal space then was desufflated. The operating table, in an extended −20° position during surgery, was placed in a 90° position for approximately 15 s. After reinsufflation, the possibility of mesh migration and folding was investigated. Finally, the mesh was stapled, the table again extended and flexed, and the possibility of mesh migration and staple dislodgement investigated once more. The mesh did not migrate or become displaced from any potential hernia area, nor did any of the staples become dislodged. Concern about mesh migration attributable to patients sitting up immediately after surgery appears to be unfounded, at least according to the findings for the current, small, simulated study group.
Real-Time Experiment of Snore Active Noise Control

This paper presents real-time experiment of active noise control (ANC) algorithms for reducing nonstationary, intermittent snore. Three snore ANC algorithms have been developed and tested to evaluate their performance. The ANC system uses both finite impulse response (FIR) and infinite impulse response (IIR) adaptive filters. Acoustic feedback was minimized by using both adaptive IIR filter and FIR filter with feedback neutralization. Real-time experiments were conducted using a digital signal processor development system and recorded snore samples. An average reduction of 15-20 dB can be achieved using multi-channel ANC systems.
Structured teaching versus experiential learning of palliative care for surgical residents.

Abstract Background Previous end-of-life and palliative care curricula for surgical residents have shown improved learner confidence, but have not measured cognitive knowledge or skill acquisition. Methods A nonrandomized trial evaluated a structured palliative care curriculum for 7 postgraduate year 2 surgical residents (intervention group) compared with 6 postgraduate year 5 surgical residents (comparison group). Outcomes were measured using an 18-item knowledge test, a 20-minute objective structured clinical examination simulating an intensive care unit family conference, and a survey measuring self-confidence. Results The mean knowledge test scores for the intervention group, both before and after undergoing the structured palliative care curriculum, were no different from the comparison group. There was also no difference in objective structured clinical examination scores between the 2 groups. The intervention group felt less comfortable managing pain, breaking bad news, or addressing ethical issues. Conclusions Junior surgical residents have similar palliative care knowledge to senior residents without a palliative care curriculum. After participating in a palliative care curriculum, they have simulated skills that are similar to chief residents. However, self-confidence is lower among junior residents despite undergoing a palliative care curriculum.
Temperature dependence of electrical conductivity

Abstract It has been shown that the temperature dependence of electrical conductivity for widely different classes of materials can be reproduced by use of the derivative of the Fermi function, G (E, T); as the probability density function in place of the Fermi function, f(E, T) [1]. The G(E, T) function has been found to be applicable to low-dimensional synthetic metallic conductors, semi-conductors, and vitreous insulators. The temperature dependence of electrical conductivity is simulated by curve-fitting the G(E, T) function to experimental conductivity versus temperature data in terms of the parameter, E = E − E F is the energy of the bottom of the conduction band and EF is the Fermi energy. It is shown that E, which lies in the band gap region, corresponds to experimentally observable absorption of energy in compounds such as (TMTSF)2 PF6, and single crystalline germanium. The quantity E can be considered as a sub-band gap activation energy. The derivation of the G(E, T) function is briefly discussed. The standard derivation of the Fermi function should yield a cumulative probability function rather than the probability density function.
Variable Fresnel Zone pattern.

Among the conceivable uses of Fresnel Zone Plates (FZP) are image formation, synthesis of holograms, coherence measurements, spectrometry, optical analog computation, and optical testing. Sometimes it is desirable to change the scale of the FZP continuously, for example to give a zoom lens effect when the FZP is used for image formation. Here we describe four ways of creating a FZP pattern as a moire effect by superposing pairs of suitable masks. The relative position of the two masks determines the FZP scale. The theory presented here is sufficiently general to allow the synthesis of patterns other than the FZP by means of a variable moire effect.
Compact silicon diffractive sensor: design, fabrication, and prototype

An in-plane constant-efficiency variable-diffraction-angle grating and an in-plane high-angular-selectivity grating are combined to enable a new compact silicon diffractive sensor. This sensor is fabricated in silicon-on-insulator and uses telecommunications wavelengths. A single sensor element has a micron-scale device size and uses intensity-based (as opposed to spectral-based) detection for increased integrability. In-plane diffraction gratings provide an intrinsic splitting mechanism to enable a two-dimensional sensor array. Detection of the relative values of diffracted and transmitted intensities is independent of attenuation and is thus robust. The sensor prototype measures refractive index changes of 10−4. Simulations indicate that this sensor configuration may be capable of measuring refractive index changes three or four orders of magnitude smaller. The characteristics of this sensor type make it promising for lab-on-a-chip applications.
Cyclotron radiation in hot magnetoplasmas

The effects of thermal motions on the cyclotron radiation from test particles gyrating in a homogeneous magnetoplasma are studied. These effects take care of all singularities that exist in the theory of cyclotron radiation in cold magnetoplasma - e.g., the divergence in energy loss for small particle energies. Around the hybrid frequencies thermal corrections become of dominant importance. At these frequencies cold-plasma theory breaks down. Thermal effects arise in two ways: by modifying the wave modes known from cold plasma theory, and by the introduction of a new longitudinal wave mode, known as the Bernstein mode. All wave modes are damped (in stable plasmas).
Out-of-Plane and in-Plane Conduction in Insulating and Strongly Underdoped Cuprates

We report measurements of out-of-plane (ρc) and in-plane (ρab) normal-state resistivities of single crystals of insulating PrBa2Cu3O7-δ and strongly underdoped oxygen deficient YBa2Cu3O6.41 using a flux transformer method. In the superconducting specimens, the onset of superconductivity was suppressed by a magnetic field of 9 T. We have found that the anisotropy ρc/ρab of these samples increases monotonically at low temperatures with no signs of saturation. The temperature dependence of ρc/ρab for YBa2Cu3O6.41 is well described by ρc/ρab=a +bT-2/3, but over a smaller temperature range than for insulating PrBa2Cu3O7-δ. Both the absence of saturation of ρc/ρab and its T-2/3 dependence indicate two-dimensional conduction. This means that the average in-plane hopping distance of the localized charge carriers increases with decreasing T according to Mott's $\bar{R}\sim T^{-1/3}$ law, while the elementary step in the c-direction remains T independent, equal to the spacing between the bilayers.
Distributed packet scheduling for multihop flows in ad hoc networks

In wireless multihop ad hoc networks, nodes need to contend for the shared wireless channel with their neighbors, which could result in congestions and greatly decrease the end-to-end throughput due to severe packet loss. Several recent papers have indicated that the IEEE 802.11 fails to achieve the optimum schedule for this kind of contentions. In this paper, we present a framework of multihop packet scheduling to achieve maximum throughput for traffic flows in the shared channel environment. The key idea is based on the observation that in the IEEE 802.11 MAC protocol the maximum throughput for chain topology is 1/4 of the channel bandwidth and its optimum packet scheduling is to allow simultaneous transmissions at nodes which are four hops away. The proposed fully distributed scheme generalizes this optimum scheduling to any traffic flows which may encounter intra-flow contentions and inter-flow contentions. Extensive simulations indicate that our scheme could perform well and achieve high throughput at light to heavy traffic load while the performance of the original IEEE 802.11 MAC protocol greatly degrades when the traffic load becomes heavy. Moreover, our scheme also achieves much better and more stable performance in terms of delay, fairness and scalability with low and stable control overhead.
Institutionalized Conflict Resolution: Have We Come to Expect Too Little?

Two very different contexts of the conflict resolution field — hostage negotiation and court-connected mediation—do share many similarities, particularly with regard to roles, responsibilities, and techniques. In both contexts, the emphasis is on the short-term "fix," or solution, rather than attention to the underlying reasons for a conflict and long-term societal change. This emphasis, though perhaps changing in the international relations area, permeates much of the institutionalized conflict resolution field and bears further examination by practitioners and researchers.
Indexing mobile objects on the plane

We present a method to index objects moving on the plane in order to efficiently answer range queries about their position in the future. This problem is motivated by real-life applications, like predicting future congestion areas in a highway system, or allocating more bandwidth for areas where high concentration of mobile phones is imminent. We consider the problem in the external memory model of computation and present a dynamic technique. An experimental evaluation is included that shows the applicability of our method.
Crystal Structures of a Group II Chaperonin Reveal the Open and Closed States Associated with the Protein Folding Cycle

Chaperonins are large protein complexes consisting of two stacked multisubunit rings, which open and close in an ATP-dependent manner to create a protected environment for protein folding. Here, we describe the first crystal structure of a group II chaperonin in an open conformation. We have obtained structures of the archaeal chaperonin from Methanococcus maripaludis in both a peptide acceptor (open) state and a protein folding (closed) state. In contrast with group I chaperonins, in which the equatorial domains share a similar conformation between the open and closed states and the largest motions occurs at the intermediate and apical domains, the three domains of the archaeal chaperonin subunit reorient as a single rigid body. The large rotation observed from the open state to the closed state results in a 65% decrease of the folding chamber volume and creates a highly hydrophilic surface inside the cage. These results suggest a completely distinct closing mechanism in the group II chaperonins as compared with the group I chaperonins.
Self-sensing of flexural damage and strain in carbon fiber reinforced cement and effect of embedded steel reinforcing bars

Self-sensing of flexural damage and strain in carbon fiber reinforced cement is attained by measuring the volume or surface resistance with the four-probe method and electrical contacts on the compression and/or tension surfaces. The oblique resistance (volume resistance in a direction between the longitudinal and through-thickness directions) increases upon loading and is a good indicator of damage and strain in combination. The surface resistance on the compression side decreases upon loading and is a good indicator of strain. The surface resistance on the tension side increases upon loading and is a good indicator of damage. The effectiveness for the self-sensing of flexural strain in carbon fiber reinforced cement is enhanced by the presence of embedded steel rebars on the tension side. For the same midspan deflection, the fractional change in surface electrical resistance is increased in magnitude, whether the surface resistance is that of the tension side or the compression side. The fractional change in resistance of the tension surface is increased by 40%, while the magnitude of the fractional change in resistance of the compression surface is increased by 70%, due to the steel.
Performance of high-speed network I/O subsystems: case study of a Fibre Channel network

Emerging high-speed networks provide several hundred megabits per second to several gigabits per second of raw communication bandwidth. However, the maximum achievable throughput available to the end-user or application is quite limited. In order to fully utilize the network bandwidth and to improve the performance at the application level, a careful examination of I/O subsystems is essential. In this paper, we study one emerging high-speed network, the Fibre Channel network. The objectives of this study are: 1) to understand how the I/O subsystem relates to network operations, 2) to evaluate and analyze the performance of such a subsystem, and 3) to propose possible approaches for improving the maximum achievable bandwidth. We will show (by simply modifying device driver code) a 75% maximum achievable bandwidth improvement. Other ways of improving network performance are also discussed.
Lamb shift with circularly polarized rf-field in foil-excited H beam

Abstract Using beam-foil excited H-atoms, time- and rf-power-dependent H - ( n = 2) Lamb-shift resonance shapes are measured with a circular polarized rf-field.
Quantifying Improvements from Refinements in a VoIP Teleconference System

In a VoIP (Voice over Internet Protocol) telephone system, we face the significant challenge of providing a teleconference feature that can support a large-scale teleconference without using excessive network bandwidth. This paper examines a new, bandwidth-efficient way of implementing a real-time VoIP teleconference system, and we present measurements of the improvements that we gained by refining our original concept. Our newly refined teleconference technique provides all of the features that previous teleconference systems provide, but our new approach consumes considerably less data bandwidth than previous systems require. The new system allows a network with a given capacity to accommodate nearly double the number of conference participants that an existing system would allow.
Synaptic Organizations of the Brain

In this chapter we study the relationship between synaptic organizations and dynamical properties of networks of neural oscillators. In particular, we are interested in which synaptic organizations can memorize and reproduce phase information. Most of our results are obtained for neural oscillators near multiple Andronov-Hopf bifurcations.
A variational principle for discontinuous potentials

Let $X$ be a compact space, $f\colon X \to X$ a continuous map, and $\Lambda \subset X$ be any $f$-invariant subset. Assume that there exists a nested family of subsets $\{\Lambda_l\}_{l \geq 1}$ that exhaust $\Lambda$, that is $\Lambda_l \subset\Lambda_{l+1}$ and $\Lambda =\bigcup_{l \geq 1} \Lambda_l$. Assume that the potential $\varphi \colon X \to \mathbb{R}$ is continuous on the closure of each $\Lambda_l$ but not necessarily continuous on $\Lambda$. We define the topological pressure of $\varphi$ on $\Lambda$. This definition is shown to have a corresponding variational principle. We apply the topological pressure and variational principle to systems with non-zero Lyapunov exponents, countable Markov shifts, and unimodal maps.
Far-field contribution of evanescent modes to the electromagnetic Green tensor

Understanding the behavior of the evanescent part of the electromagnetic field has important implications in many branches of modern physics, such as near-field optics. Motivated by recent disagreement in the literature, we derive an expression for the far-field asymptotic behavior of the free-space electromagnetic Green tensor that is due to the evanescent modes.
Parallel unit tangent vector computation for homotopy curve tracking on a hypercube

Probability-one homotopy methods are a class of methods for solving nonlinear systems of equations that are globally convergent from an arbitrary starting point. The essence of all such algorithms is the construction of an appropriate homotopy map and subsequent tracking of some smooth curve in the zero set of the homotopy map. Tracking a homotopy curve involves finding the unit tangent vectors at different points along the zero curve. Because of the way a homotopy map is constructed, the unit tangent vector at each point in the zero curve of a homotopy map ra(l,k) is in the kernel of the Jacobian matrix Dra(l,k). Hence, tracking the zero curve of a homotopy map involves finding the kernel of the Jacobian matrix Dra(l,k). The Jacobian matrix Dra is a n × (n+1) matrix with full rank. Since the accuracy of the unit tangent vector is very important, an orthogonal factorization instead of an LU factorization of the Jacobian matrix is computed. Two related orthogonal factorizations, namely QR and LQ factorization, are considered here. This paper presents computational results showing the performance of several different parallel orthogonal factorization/triangular system solving algorithms on a hypercube. Since the purpose of this study is to find ways to parallelize homotopy algorithms, it is assumed that the matrices have a special structure such as that of the Jacobian matrix of a homotopy map. In particular, we are interested in relatively small and dense Jacobians.
Prolyl endopeptidase activity in bronchoalveolar lavage fluid: a novel diagnostic biomarker in a guinea pig model of invasive pulmonary aspergillosis

Improved diagnostics are needed to detect invasive pulmonary aspergillosis, a life-threatening infection caused by the pathogenic fungus Aspergillus fumigatus . We are investigating secreted fungal proteases as novel biomarkers for the diagnosis of this disease. Although the A. fumigatus genome encodes a multitude of secreted proteases, few have been experimentally characterized. Here, we employed an unbiased combinatorial library of internally quenched fl uorogenic probes to detect infection-associated proteolysis in the lungs of guinea pigs experimentally infected with A. fumigatus . Comparative protease activity profi ling revealed a prolyl endopeptidase activity that is reproducibly induced during infection but is not observed in healthy animals. This proteolytic activity was found in four independent animal experiments involving two A. fumigatus isolates. We synthesized a small, focused fl uorogenic probe library to defi ne the substrate specifi city of the prolyl endopeptidase substrate motif and to identify optimal Probe sequences. These efforts resulted in the identifi cation of a panel of six individual substrate-based fl uorescent probes capable of detecting infection in guinea pigs with high statistical signifi cance ( P 0.005 in most cases). Receiver operating characteristic analyses demonstrated that this fl uorogenic assay could detect A. fumigatus infection-associated proteolysis with comparable sensitivity and specifi city as existing diagnostic procedures, suggesting that further optimization of the methodology may lead to improved diagnostics options for invasive pulmonary aspergillosis.
Differential effects of landscape‐level environmental features on genetic structure in three codistributed tree species in Central America

Landscape genetic studies use spatially explicit population genetic information to determine the physical and environmental causes of population genetic structure on regional scales. Comparative studies that identify common barriers to gene flow across multiple species within a community are important to both understand the evolutionary trajectories of populations and prioritize habitat conservation. Here, we use a comparative landscape genetic approach to ask whether gradients in temperature or precipitation seasonality structure genetic variation across three codistributed tree species in Central America, or whether a simpler (geographic distance) or more complex, species-specific environmental niche model is necessary to individually explain population genetic structure. Using descriptive statistics and causal modelling, we find that different factors best explain genetic distance in each of the three species: environmental niche distance in Bursera simaruba, geographic distance in Ficus insipida and historical barriers to gene flow or cryptic reproductive barriers for Brosimum alicastrum. This study confirms suggestions from previous studies of Central American tree species that imply that population genetic structure of trees in this region is determined by complex interactions of both historical and current barriers to gene flow.
PiCoDes: Learning a Compact Code for Novel-Category Recognition

We introduce PICODES: a very compact image descriptor which nevertheless allows high performance on object category recognition. In particular, we address novel-category recognition: the task of defining indexing structures and image representations which enable a large collection of images to be searched for an object category that was not known when the index was built. Instead, the training images defining the category are supplied at query time. We explicitly learn descriptors of a given length (from as small as 16 bytes per image) which have good object-recognition performance. In contrast to previous work in the domain of object recognition, we do not choose an arbitrary intermediate representation, but explicitly learn short codes. In contrast to previous approaches to learn compact codes, we optimize explicitly for (an upper bound on) classification performance. Optimization directly for binary features is difficult and nonconvex, but we present an alternation scheme and convex upper bound which demonstrate excellent performance in practice. PICODES of 256 bytes match the accuracy of the current best known classifier for the Caltech256 benchmark, but they decrease the database storage size by a factor of 100 and speed-up the training and testing of novel classes by orders of magnitude.
Effects of non-uniformity on rollover phenomena in CdS/CdTe solar cells

The behavior of CdS/CdTe devices with very little Cu in the back-contact was investigated. Though the devices maintain decent voltage (V oc ∼760–780 mV), the fill factor suffers (FF ∼ 45–50%) due to a secondary curvature in the power quadrant of the J-V plane. Capacitance results indicate full depletion, and laser-beam-induced-photocurrent mapping indicates spatial QE variations of several percent at voltage-bias near that of the initial diode turn-on. Guided by the LBIC results, we have developed an expanded equivalent circuit model to approximate effects of non-uniform back-contact barrier not explained by the traditional two-diode model [1]. PSpice modeling of the new circuit model successfully accounts for the non-standard rollover in the experimental J-V behavior.
Equilibration of a warm pumped lens on a β plane

Abstract The dynamics of a warm lens created by a surface buoyancy flux and Ekman pumping in an initially homogeneous, unbounded fluid on a β plane is studied in a set of high-resolution numerical experiments. A simple analytical model for the equilibrium structure of the lens is developed that assumes that the input of vorticity and buoyancy from the Ekman layer is balanced through transfer by baroclinic eddies that carry the warm fluid laterally away from the lens. The importance of eddy-induced diapycnal flux in the western intensification region is emphasized by developing a boundary layer theory based entirely on the cross-frontal mass exchange due to eddies. The theory is successfully tested against direct numerical eddy-resolving simulations. Possible oceanographic implications of the study for understanding subtropical gyres and the Antarctic Circumpolar Current are discussed.
Spatial and Temporal Variability in Shipping Traffic Off San Francisco, California

Shipping traffic poses a worldwide threat to many large whale species. Spatially explicit risk assessments are increasingly being used as a tool to minimize ship-strike risk. These assessments often use static representations of shipping patterns. We used Automatic Identification System data to quantify variability in cargo shipping traffic entering and exiting San Francisco Bay, which contains some of the busiest ports in the United States, at three temporal resolutions: (1) before and after implementation of the California Air Resources Board's Ocean-Going Vessels Fuel Rule, (2) among seasons, and (3) day versus night. We used the nonparametric Mood's Median test to compare median daily distance traveled because the data were not normally distributed and the variance was not homogeneous. Our analyses show that shipping traffic off San Francisco is dynamic at both interannual and daily temporal resolutions, but that traffic was fairly consistent among the seasons considered. Our analyses emphasize the im...
A Comparison of Electron and Photon Beams for Obtaining Inner Shell Spectra

Recently there has been considerable interest shown in the use of synchrotron radiation as a tunable X-ray source2,3 and electron energy loss spectroscopy within the electron microscope4,5 for performing chemical and electronic spectroscopy of matter. It is worthwhile to compare these two kinds of radiation as to their sensitivity and applicability for studying different systems.
Viscoplastic Responses With Stochastic Q-Damping Or Soil

Viscoelastic responses in mechanical systems are significantly influenced by material damping losses. In time dependent steady harmonic vibration problems, energy loss per cycle generally varies with the frequency of excitation. In a large number of geophysical computations, however, frequency independent Q-models — a higher value of Q indicating less damping — are routinely chosen for convenient representation of soil damping characteristics in the visco-plastic regime dominated by nonlinear effects.
Insulin-induced anestrus in Syrian hamsters.

In Syrian hamsters, reproduction is sensitive to the availability of metabolic fuels. Estrous cycles can be interrupted by brief periods of food deprivation, by pharmacological inhibition of glycolysis and fatty acid oxidation, or by increasing energy demands for thermoregulation. We predicted that manipulations that divert an excessive portion of the metabolic fuel supply into storage also should inhibit reproduction. Redirection of metabolic fuels from oxidation to storage was accomplished by treatment with protamine zinc insulin suspension (PZI). Syrian hamsters treated with PZI and fed ad libitum increased their food intake by approximately equal to 40% and body fat stores, but there was no effect on estrous cycles. When PZI-treated hamsters were limited to approximately equal to 110% of their preinjection food intake, they still fattened, and there was a significant inhibition of estrous cyclicity. Thus, in the absence of overeating, PZI-enhanced energy storage may lead to a shortage of oxidizable metabolic fuels with the result that reproduction is inhibited in favor of processes essential for survival (e.g., cellular maintenance, thermoregulation). It is unlikely that insulin-induced anestrus is due to actions of PZI unrelated to metabolic fuel partitioning, because the hormone had no effects on estrous cyclicity in ad libitum-fed hamsters. These findings are inconsistent with the hypothesis that nutritional infertility is due to the failure to maintain a minimum body fat content and raise the possibility that the infertility associated with some types of obesity could be due in part to a disorder of macronutrient partitioning.
Design-for-Testability for Functional Broadside Tests under Primary Input Constraints

Functional broadside tests avoid overtesting of delay faults by creating functional operation conditions during the clock cycles where delay faults are detected. When a circuit is embedded in a larger design, a functional broadside test needs to take into consideration the functional constraints that the design creates for its primary input vectors. At the same time, application of primary input vectors as part of a scan-based test requires hardware support. An earlier work considered the case where a primary input vector is held constant during a test. The approach described in this article matches the hardware for applying primary input vectors to the functional constraints that the design creates. This increases the transition fault coverage that can be achieved by functional broadside tests. This article also considers the effect on the transition fault coverage achievable using close-to-functional broadside tests.
The effects of caffeine ingestion on exercise-induced hypoalgesia: A pilot study

Exercise acutely reduces pain sensitivity, termed exercise-induced hypoalgesia (EIH). The mechanisms underlying EIH remain unclear. Caffeine, a non-specific adenosine receptor antagonist has been shown to attenuate EIH in animals-suggesting the involvement of the adenosinergic system. This pilot study investigated the effects of caffeine on pain sensitivity following cycling exercise in college-aged men. Pressure pain threshold (PPT) and thermal pain threshold (TPT) were assessed in thirteen low caffeine consuming men prior to ingestion of a counter-balanced 5mg·kg(-1) dose of caffeine or a placebo (Pre), 60min following ingestion (Post-In), and then following a 15min bout of cycling exercise (Post-Ex) at an intensity eliciting a quadriceps muscle pain rating of 3 out of 10. Nine of the men completed follow-up testing which was identical except that the exercise consisted of 10min of cycling eliciting a pain rating of 5 out of 10. Caffeine had no effect compared to placebo on PPT (p≥0.15) or TPT (p≥0.41) 60min following ingestion and following exercise. PPT increased from 599±176kPa to 648±202kPa (p=0.009) and from 578±217kPa to 666±278kPa (p=0.01) following 15 and 10min of cycling, respectively. TPT increased from 46.2±2.9°C to 46.8±2.6°C (p=0.008) following the 15min exercise bout, but did not change (46.4±3.6°C vs. 46.8±3.3°C; p=0.24) following the shorter, higher intensity exercise bout. The results from this study indicate cycling exercise reduces pain sensitivity, especially to pressure stimuli. Caffeine ingestion did not alter the EIH response-suggesting adenosine may not play a prominent role in the EIH response in humans.
Development of a troponin I biosensor using a peptide obtained through phage display

A small synthetic peptide with nanomolar affinity for cardiac troponin I (TnI), previously identified from a polyvalent phage displayed library, has been immobilized on a gold surface for TnI detection. The binding affinity of gold-immobilized peptides for TnI was studied and compared with that of phage-immobilized peptides. Quartz crystal microbalance (QCM), cyclic voltammetry, and electrochemical impedance spectroscopy (EIS) were used to monitor both the immobilization and target binding processes. All three techniques show that the binding is specific for TnI as compared to a streptavidin (SA) control. The response curves obtained at TnI concentrations ranging from 0 to 10 μg/mL, using both QCM and EIS, were also compared. For the EIS measurements, the sensitivity was 0.30 ± 0.030 normalized impedance/(μg/mL) and the limit of detection (LOD) was 0.34 μg/mL. Using the QCM, a sensitivity of 18 ± 1 Hz/(μg/mL) was obtained, corresponding to an LOD of 0.11 μg/mL. Although the QCM demonstrated a lower LOD as compared to EIS, the latter technique exhibited a larger linear dynamic range than QCM. In a relevant tissue culture milieu, Minimum Essential Media (MEM), the sensitivity of the EIS measurement was greater than that obtained in a phosphate buffer system (PBS). The kinetics of target binding using QCM were analyzed by two independent methods, and the dissociation constants (K(D) = 66 ± 4 nM and 17 ± 8 nM) were an order of magnitude higher than that calculated for the polyvalent phage particles (K(D) = 2.5 ± 0.1 nM). Even though the affinity of the immobilized peptides for TnI was somewhat reduced, overall, these results demonstrate that peptides obtained from the biopanning of phage display libraries can be readily used as sensing probes in biosensor development.
Reactive synaptogenesis in the CNS. A comparison of regenerating and sprouting systems.

Lesion-induced synaptogenesis was compared in the goldfish retinotectal system, which readily regenerates after optic nerve crush, and in the cat spinal cord, in which collateral sprouting has been demonstrated after dorsal rhizotomy. Quantitative electron micro-scopic methods were used. Reinnervation of the tectum was complete, but was characterized by a prolonged time course. Reinnervation appeared to be achieved by retinal axons and not by sprouting from nonretinal axons. Reinnervation in the cat spinal cord was also virtually complete, but was very rapid and may be mediated by some axons that are similar to those destroyed and by other axons that are different.
Face fly: inhibition of hatch by diflubenzuron and related analogues.

When mixed sexes of 1-, to 2 day-old adult Musca Autumnalis De Geer were fed diflubenzuron ( N -[[ (4-chlorophenyl) amino]carbonyl]-2,6-difluorobenzamide) in a diet or were exposed to diflubenzuron by surface contact, egg hatch was severely inhibited. In 3 treatments, untreated females produced few viable eggs when crossed with treated males. Optimum inhibition of egg hatch occurred when either sex was exposed for 15 min to a surface coated with a diflubenzuron dust (25%-WP). Three closely related analogues of diflubenzuron (AI3-63219, AI3-63220, and AI3-63223) also inhibited hatch but none was significantly better than diflubenzuron.
MaterialCloning : Acquiring Elasticity Parameters from Images for Medical Applications

We present a practical approach for automatically estimating the material properties of soft bodies from two sets of images, taken before and after deformation. We reconstruct 3D geometry from the given sets of multiple-view images; we use a coupled simulation-optimization-identification framework to deform one soft body at its original, non-deformed state to match the deformed geometry of the same object in its deformed state. For shape correspondence, we use a distance-based error metric to compare the estimated deformation fields against the actual deformation field from the reconstructed geometry. The optimal set of material parameters is thereby determined by minimizing the error metric function. This method can simultaneously recover the elasticity parameters of multiple types of soft bodies using Finite Element Method-based simulation (of either linear or nonlinear materials undergoing large deformation) and particle-swarm optimization methods. We demonstrate this approach on real-time interaction with virtual organs in patient-specific surgical simulation, using parameters acquired from low-resolution medical images. We also highlight the results on physics-based animation of virtual objects using sketches from an artist's conception.
Multidrug-Resistant Bacterial Donor-Derived Infections in Solid Organ Transplantation

Although rare, donor-derived infections (DDIs) caused by multidrug-resistant (MDR) bacteria can have devastating consequences for organ transplant recipients. Recognition of MDR bacterial DDIs can be challenging, as MDR bacteria are prevalent in most hospitals and distinguishing their transmission through transplantation from other, more typical routes of acquisition are difficult. New technologies such as whole genome sequencing have recently proven to be a powerful advance in the investigation of MDR bacterial DDIs. Once recognized, the optimal treatment of MDR bacterial DDIs is not clear. Herein, we review the clinical manifestations, outcomes, and management of MDR bacterial DDIs, and identify areas of uncertainty toward which the transplant community should direct further research efforts.
Consistency between Regional and Subregional Transportation Models: a case study in Orange County and Irvine Transportation Analysis Models of Southern California

This paper introduces regional and subregional transportation models, and their interfacing methods. Taking Orange County and Irvine transportation analysis models of Southern California, U.S. as an example, the paper illustrates the detailed procedures to achieve transportation modeling consistency. First of all, it is necessary to ensure modeling input consistency through building a three-tiered Transportation Analysis Zone (TAZ) system, applying the land use/socioeconomic data conversion factors, and following the highway network coding conventions consistent with those of regional transportation models. Moreover, subregional modeling outputs need to be properly postprocessed to better match observed traffic counts. Model validation results indicated that the -4.2% error between the transportation analysis models of Irvine and Orange County confirmed the consistency between the two models.
Using Delta-Generalized Additive Models to Predict Spatial Distributions and Population Abundance of Juvenile Pink Shrimp in Tampa Bay, Florida

AbstractIn this article, we present an approach based on generalized additive models (GAMs) to predict species’ distributions and abundance in Florida estuaries with habitat suitability modeling. Environmental data gathered by fisheries-independent monitoring in Tampa Bay from 1998 to 2008 were interpolated to create seasonal habitat maps for temperature, salinity, and dissolved oxygen and annual maps for depth and bottom type. We used delta-GAM models assuming either zero-adjusted gamma or beta-inflated-at-zero distributions to predict catch per unit effort (CPUE) from five habitat variables plus gear type for each estuarine species by life stage and season. Bottom type and gear type were treated as categorical predictors with reference parameterization. Three spline-fitting procedures (the penalized B-spline, cubic smoothing spline, and restricted cubic spline) were applied to the continuous predictors. Two additive, linear submodels on the log and logistic scales were used to predict CPUEs >0 and CPUEs...