cssi/SciSciGPT-SciSciNet huggingface dataset:
Site-specific drug delivery and penetration enhancement in the gastrointestinal tract

Abstract New types of biodegradable and pH-sensitive hydrogels were synthesized by the crosslinking of polymeric precursors. They contained both acidic comonomer and enzymatically degradable azoaromatic crosslinks. Such hydrogels are suitable for colon-specific drug delivery. In the low pH range of the stomach, the swelling of the gel is low and the drug is protected against digestion by enzymes. In the small intestine, the swelling increases. Upon arrival in the colon, a degree of swelling is reached that makes the crosslinks accessible to azoreductase activity. The gel is degraded and drug released. The hydrogels were characterized by the network structure (i.e., content of crosslinks, unreacted pendent groups, and cycles), the equilibrium and dynamic swelling as a function of pH, modulus of elasticity, and in vitro/in vivo degradation. The results indicated that the hydrogel network structure strongly depends on the reaction conditions such as polymer concentration, and the ratio of the reactive groups during the crosslinking reaction. The swelling and mechanical properties of hydrogels can be controlled by the modification of polymer backbone structure and/or the crosslinking density. Depending on the network structure, the degradation of hydrogels followed either a surface erosion or a bulk-degradation-like process. In vivo degradation rate of hydrogels was three to five times faster than that in vitro. The effect of a penetration enhancer, CapMul MCM (a medium chain glyceride), on physiological properties of rabbit intestinal epithelium was investigated in vitro using the Ussing chamber technique. It was shown that CapMul MCM affected tissue ion transport, permeability, and morphology in a concentration- and time-dependent manner. It was found that with minimal epithelial disruption and moderate change in ion transport in the colon, the increase in marker molecule permeabilities ranged between 7 and 25 times depending upon their molecular weight.
A counterexample to the Alexopoulos-Griffin path planning algorithm

The planar stationary-obstacle path-planning problem for polygonal obstacles has been correctly and completely solved by T. Lozano-Perez and M. Wesley (1979), i.e., a global, optimal algorithm was provided which requires O(/spl mu//sup 2/log/spl mu/) computation time, where /spl mu/ is the number of obstacle-faces in the scene. That algorithm is known as the VGRAPH algorithm. Two variants of VGRAPH have been developed to solve the same problem in O(/spl mu//sup 2/) computation time. Our paper discusses a recent algorithm proposed by C. Alexopoulos and P.M. Griffin (1992), called V*GRAPH, which also claims to provide an optimal solution. We demonstrate by counter-example that V*GRAPH is neither global nor optimal.
Assessing accuracy of manually-mapped wildfire perimeters in topographically dissected areas

Accurate mapping of wildfires is critical to fire management. Technological advances in remote sensing and Geographic Information Systems (GIS) over the last decade have been widely incorporated into wildfire mapping and management, but neither have been assessed for accuracy nor compared to established manual methods. Since Landsat-based mapping of wildfires will soon replace manual mapping methods, this type of comparison is critical to understanding the strengths of each method. Landsat ETM+ imagery was classified to create fire perimeter maps for 53 fires in Nevada, USA. These maps were then assessed for agreement with published, manually mapped fire perimeters. Published perimeters were found to correlate poorly to remotely sensed fire perimeters, and significantly overestimated area burned (p ≤ 0.05) by an average of 18 percent. Mapping disagreement was then correlated to a measure of topographic roughness at four spatial scales to determine whether increasing terrain complexity was a factor in increased disagreement. Mapping disagreement showed a significant positive correlation (r = 0.57) to topographic roughness. For fire research spanning multiple decades, these results indicate that it may be difficult to utilize fire perimeter data sets comprising both satellite-derived and manually mapped perimeters because the two data sets are significantly different.
Care and competence in medical practice: Francis Peabody confronts Jason Posner

In this paper, I discuss the role of care and competence, as well as their relationship to one another, in contemporary medical practice. I distinguish between two types of care. The first type, care1, represents a natural concern that motivates physicians to help or to act on the behalf of patients, i.e. to care about them. However, this care cannot guarantee the correct technical or right ethical action of physicians to meet the bodily and existential needs of patients, i.e. to take care of them—care2. To that end, physicians must be competent in the practice of medicine both as evidence—based science (technical competence) and as patient—centered art (ethical competence). Only then, I argue, can physicians take care of (care2) patients’ bodily and existential needs in a compassionate and comprehensive manner. Importantly, although care1 precedes competence, competence—both technical and ethical—is required for genuine care2, which in turn reinforces an authentic care1. I utilize the play Wit, especially the character Jason Posner, and Francis Peabody’s exposition on caring for patients, to illustrate the role of care and competence in contemporary medical practice.
Sensitivity of Modeled C- and L-Band Radar Backscatter to Ground Surface Parameters in Loblolly Pine Forest

Abstract Variations and fluctuations of forest floor scattering properties can lead to variability in radar backscatter from forest, thereby interfering with SAR backscatter-based estimation of forest biophysical characteristics. Understanding how forest backscatter varies over the range of probable surface conditions is important in the selection of appropriate radar bands and incidence angles for forest sensing applications and for quantifying uncertainty of the derived forest characteristics. Using a canopy backscatter model, we examined the sensitivity of modeled C- and L-band backscatter to five surface parameters in three loblolly pine stands representing different stages of development in Duke Forest (NC). The parameters were litter depth and moisture content, soil rms height and correlation length, and soil moisture content. Of the bands considered, L-HH backscatter had the highest sensitivity to the surface parameters, followed by L-VV. In the incidence angle range of 20°–40°, L-HH varied by 5.3–9.6 dB as the surface parameters changed over their range, whereas L-VV varied by 3.7–4.5 dB. At shallower incidence angles, the sensitivities were lower but probably not negligible. C-HH and C-VV were sensitive only at steep incidence θ 0 =20°–30° for the lowest biomass stand studied. C-HH and C-VV sensitivity fell off with increasing incidence angle and stand maturity. L-HV showed slight sensitivity for the low-biomass stand and at θ0=20°–30° but was otherwise insensitive. C-HV was insensitive to the surface for all stands and angles. At L-band, the most influential of the five parameters was soil rms height, whereas, at C-band, all parameters were about equal in influence. The modeled sensitivities suggested that the surface-related uncertainty in forest backscatter at L-HH and L-VV, and at C-HH and C-VV at steep incidence angles, may be unacceptably large for many applications.
RABIES ANTIBODY PREVALENCE AND VIRUS TISSUE TROPISM IN WILD CARNIVORES IN VIRGINIA

Carnivores trapped in a rabies control program in Virginia were examined for rabies virus and serum neutralizing antibody. Local antibody prevalence ranged from 0% to 29% in gray foxes (Urocyon cinereoargenteus). Rabies virus was pantropic in naturally infected gray foxes and a bobcat (Lynx rufus).
SU-FF-I-74: Comparison of Image Quality in Contact and Magnification Modes in Digital Mammography

Purpose: To compare image quality in contact and magnification modes in digital mammography.Method and Materials:Images of three anthropomorphic breast phantoms were acquired using a Hologic FFDM system. First, images were acquired in contact mode with grid. The exposure parameters were determined by AEC. Second, images were acquired in 1.5x magnification mode without grid. The exposure parameters were selected such that the detector entrance exposures were the same as those in the first experiment. The third, images were acquired in contact mode with grid and with the same patient doses in magnification mode. Image quality was analyzed using MIPAV software. Results: 9lp/mm and 6lp/mm were resolved in the magnification mode and in the contact mode respectively. However, the smallest specks group in the phantoms (0.13 mm) could be detected in all modes. For masses and fibers, more features were detected in the magnification mode when the detector entrance exposures were fixed at those determined in the contact mode. More masses and fibers were detected in contact mode when the breast skin entrance exposures were the same as those in the magnification mode. Conclusion: At the same patient dose, the contact mode provides better detectability of masses and fibers. The detectability of microcalcification above 0.13 mm is not improved by using the magnification mode. The detectability of smaller microcalcifications (<0.13 mm) needs further investigation.
Creating Empathy Through Use of a Hearing Voices Simulation

Abstract Background It is estimated that approximately 75% of patients with schizophrenia have auditory hallucinations. Nursing students may read about the symptom of auditory hallucinations yet may not fully appreciate how it interferes with the patient's concentration or simple dialogue with others. Students may become impatient with slow responses, and not appreciate that the patient is having two conversations: one with the student and another with the voices. Without understanding, students may lack empathy for psychiatric patients. A study was conducted to determine whether students' empathy increased after a simulation that used a learning tool called Simulated Experience of Hearing Voices That Are Distressing. Method The study used mixed methods to gather data from Likert-type scale measures of students' self-rated empathy pre- and postsimulation and their written reflections after the simulation experience. A t-test analysis was conducted on pre–post empathy ratings, and content theme analysis was performed on students' reflections. Results Analysis of pre- and postsimulation measures found significant differences in students' empathy. Content theme analysis showed students were transformed by the experience. After the simulation, they acknowledged more understanding of psychiatric patients and more empathy for the challenges patients faced. Students wanted to show more patience during interactions. Conclusions Results supported an increase in students' empathy after the simulation, and reflective statements showed they were changed by the experience. As a result of the Hearing Voices simulation, students intended to demonstrate more understanding, patience, and kindness toward patients in general.
Enzymatic evidence for the presence of a critical terminal hexa-arabinoside in the cell walls of Mycobacterium tuberculosis

A species of Cellulomonas was isolated from soil by enrichment culture and shown to secrete enzymes capable of degrading mycobacterial cell wall arabinogalactan, both the insoluble peptidoglycan-bound and base-solubilized forms. The major degradation product was purified and characterized as a hexa-arabinofuranoside, [beta-D-Araf-(1-->2)-alpha-Araf-(1-->]2-->3,5-alpha-D-Ara f-(1-->5)-D-Araf. The non-reducing ends of this unit are the sites of mycolic acid attachment and, as they also appear in lipoarabinomannan (LAM), the point of mannose capping in some mycobacteria. Thus, elaboration of the structure of this focal hexasaccharide is critical to our understanding of much of the physiology and pathogenesis of mycobacteria. The extracellular enzymes of Cellulomonas sp. also released the disaccharide, alpha-D-Araf-(1-->5)-D-Araf, from internal linear regions of arabinan and, surprisingly, convert the linear galactan backbone into cyclic oligosaccharides of the structure [-->5-D-Galf-(1-->6)-beta-D-Galf-(1-->]n where n is 2, 3 or 4. Thus, the preparation contains Schardinger-like enzyme activity. This group of enzymes are powerful tools for the dissection of the mycolylarabino-galactan-peptidoglycan (mAGP) complex of mycobacteria towards understanding its role in drug resistance, disease processes and mycobacterial physiology.
Death depression and death anxiety in HIV-infected males

Abstract The death anxiety and death depression of 94 HIV-infected gay men in Southern California were determined as a function of subjective state, medical status, and psychosocial variables. They were administered the Death Anxiety Scale, Death Depression Scale, Beck Depression Inventory, State-Trait Anxiety Scale, and a questionnaire assessing demographic and life-situation variables. Higher death anxiety and death depression were most highly correlated with state anxiety, trait anxiety, depression, severity of medical status, and severity of disability.
Direct in situ measurements of Li transport in Li-ion battery negative electrodes

Abstract We describe the first direct in situ measurements of Li transport in an operating cell. Motion of the lithiation front in the graphite electrode suggests that transport could be controlled by liquid-phase diffusion. The electrochemical (current–voltage) data are successfully modeled with a diffusion equation that contains no material or microstructural information. The model is only qualitatively successful in predicting observed Li transport rate data, suggesting that microstructural information is required and that the actual process is more complex than simply diffusion. The technique can provide data for studying Li plating and Li dendrite growth, both of which can cause battery degradation.
Transforming growth factor beta1 modulates extracellular matrix organization and cell‐cell junctional complex formation during in vitro angiogenesis

Transforming growth factor-beta 1 (TGF-beta 1) is angiogenic in vivo. In two-dimensional (2-D) culture systems microvascular endothelial cell proliferation is inhibited up to 80% by TGF-beta 1; however, in three-dimensional (3-D) collagen gels TGF-beta 1 is found to have no effect on proliferation while eliciting the formation of calcium and magnesium dependent tube-like structures mimicking angiogenesis. DNA analyses performed on 3-D cell cultures reveal no significant difference in the amount of DNA or cell number in control versus TGF-beta 1 treated cultures. In 2-D cultures TGF-beta 1 is known to increase cellular fibronectin accumulation; however, in 3-D cultures no difference is seen between control and TGF-beta 1 treated cells as established by ELISA testing for type IV collagen, fibronectin, and laminin. In 3-D cultures there is increased synthesis and secretion of type V collagen in both control and TGF-beta 1 treated cultures over 2-D cultures. Even though an equal amount of type V collagen is seen in both 3-D conditions, there is a reorganization of the protein with concentration along an organizing basal lamina in TGF-beta 1 treated cultures. EM morphological analyses on 3-D cultures illustrate quiescent, control cells lacking cell contacts. In contrast, TGF-beta 1 treated cells show increased pseudopod formation, cell-cell contact, and organized basal lamina-like material closely apposed to the "abluminal" plasma membranes. TGF-beta 1 treated cells also appear to form junctional complexes between adjoining cells. Immunofluorescence using specific antibodies to the tight junction protein ZO-1 results in staining at apparent cell-cell junctions in the 3-D cultures. Northern blots of freshly isolated microvascular endothelium, 2-D and 3-D cultures, using cDNA and cRNA probes specific for the ZO-1 tight junction protein, reveal the presence of the 7.8 kb mRNA. Western blots of rat epididymal fat pad endothelial cells (RFC) monolayer lysates probed with anti-ZO-1 label a 220 kd band which co-migrates with the bonafide ZO-1 protein. These data confirm and support the hypothesis that TGF-beta 1 is angiogenic in vitro, eliciting microvascular endothelial cells to form tube-like structures with apparent tight junctions and abluminal basal lamina deposition in three-dimensional cultures.
Purdue pegboard performance of disabled and normal readers: unimanual versus bimanual differences.

Abstract Differences between dyslexics and controls in the unimanual and bimanual conditions of the peg placement section of the Purdue Pegboard Test were examined. Twenty-three disabled and twenty-three normal readers were studied. The groups were carefully screened on a neuropsychological battery. The disabled readers were comprised of a relatively homogeneous language-disordered subgroup exhibiting deficits in naming. Significant Group × Condition interactions were obtained for both raw and percentile scores and indicated that disabled readers performed worse than controls in the unimanual compared to bimanual conditions. The dyslexics performed particularly poorly compared with controls on the left hand condition. The implications of these data for hypotheses which argue for left hemisphere dysfunction, as well as those which posit interhemispheric transfer deficits in reading disabled children, are discussed.
Interaction of the protonated Schiff base with the peptide backbone of valine 49 and the intervening water molecule in the N photointermediate of bacteriorhodopsin.

The effects of replacing Val49, Thr46, Asp96, and Phe219 in the cytoplasmic domain of bacteriorhodopsin on water O−H stretching vibrational bands and the amide I and imide II bands of the peptide b...
The future of the Arctic: cauldron of conflict or zone of peace?

The forces of climate change and globalization are transforming the Arctic, tightening the links between this seemingly remote region and the world at large with regard to matters of environmental protection, sustainable development, and the pursuit of peace. This has triggered an explosion of both popular and scholarly interest in the far north. Much of the resultant literature is marked by persistent expectations that the Arctic will become the scene of escalating jurisdictional conflicts, resource wars, a new great game and even armed clashes during the coming years. Yet as the books considered in this review article make clear, these expectations are greatly exaggerated; there is much to be said for the proposition that armed conflict is less likely to occur in the Arctic than in most other parts of the world anytime soon. What is needed is an alternative paradigm to provide a basis for understanding the significance of the profound changes now eroding the old order in the Arctic and establishing a basis for framing innovative governance arrangements capable of ensuring the future of the Arctic as a zone of peace.
Increased left ventricular mass in patients with lateral low-voltage electrocardiograms

Abstract High R or S voltage is a relatively specific electrocardiographic indicator of left ventricular (LV) hypertrophy. Low voltages are common in hospital patients, frequently interfering with electrocardiographic sensitivity for LV hypertrophy. The R voltage ratio between leads V 5 and V 6 (RV 6 :RV 5 ) is a relatively good indicator of LV hypertrophy, 1 and sometimes identifies increased LV mass when other criteria fail. 2 Thus, we investigated RV 6 :RV 5 to see if it was independent of absolute voltages. Because RV 6 >RV 5 in a consecutive unselected echocardiographic laboratory population had a 57% sensitivity and a 91% specificity for LV hypertrophy, and compared well with Cornell voltage (41%, 100%) and Romhilt-Estes point score (39%, 97%), 1 we investigated whether RV 6 :RV 5 would also apply at low voltages in leads V 5 and V 6 (which excludes criteria highly dependent on voltages in these leads). We examined a new series of 50 consecutive, but this time selected, patients studied in the echocardiography laboratory who had low QRS voltage in V 5 and V 6 , and again compared performance of the ratio with other standard criteria in identifying increased LV mass. Loss of electrocardiographic voltage occurs relatively often in seriously ill patients and is frequently associated with metabolic abnormalities and other factors like pleural effusion and pulmonary emphysema 3 that diminish total and especially lateral precordial voltage. Since such patients would not acutely lose hypertrophic cardiac mass, we reexamined the ratio in 2 groups selected for low absolute voltage.
Orientation effects in electron transfer collisions

Abstract … these atoms move in the infinite void, separate one from another and differing in shapes, sizes, position and arrangement; overtaking each other they collided, and some are shaken away in any chance direction, while others, becoming intertwined one with another according to the congruity of their shapes, sizes, positions, and arrangements, stay together and so effect the coming into being of compound bodies. (Simplicius) The influence of molecular orientation upon electron transfer has been probed with oriented target molecules in crossed molecular beams. Electron transfer frequently occurs in thermal energy reactive collisions, but at thermal energies charged species can rarely escape their mutual Coulomb attraction, and only neutral products are formed. By increasing the collisional energy to a few eV, the charged species can be separated, and the role of orientation on the electron transfer process can be probed. Collisional ionization of fast (= 3-20 eV) neutralK atoms has been observed for...
Offense and defense: microbial membrane vesicles play both ways.

Microbes have evolved over millennia to become adapted and specialized to the environments that they occupy. These environments may include water or soil, extreme environments such as hydrothermal vents, and can even include a host organism. To become adapted to these locations, microbes have evolved specific tools to mediate interactions with the environment. One such tool that prokaryotes have evolved includes the production of membrane vesicles (MVs). MVs are 10–300 nm spherical blebs derived from the outermost membrane and have known functions in protein secretion, immune activation and suppression, stress response, attachment, internalization and virulence. In this review, we consider the highly conserved role of membrane vesicles derived from Gram-negative, Gram-positive and archaeal species as a mechanism to facilitate intermicrobial and microbe-host interaction. We examine both the offensive and defensive capabilities of MVs in regard to the interaction of MVs with both host and microbial cells in their environment.
junD mRNA expression differs from c-jun and junB mRNA expression during male germinal cell differentiation.

The members of the jun family of protooncogenes (junB, c-jun, and junD) share a high degree of sequence homology and function as transcriptional regulators. Here we compare the pattern of junD mRNA expression during spermatogenesis to that of junB and c-jun (Alcivar et al.: J Biol Chem 265:20160–20165, 1990). junD transcripts are present at high levels in total RNA obtained from both prepuberal and adult intact testes, with the highest levels at stages containing predominantly premeiotic and postmeiotic germ cells. Analyses of cells isolated from testes of 8-day-old mice indicate that the level of the 1.8 kb junD mRNA is higher in type B spermatogonia than in type A spermatogonia. In testes of 17-day-old mice, the highest junD mRNA levels are detected in preleptotene spermatocytes compared to leptotene/zygotene and prepuberal pachytene spermatocytes. In cells from adult testes, the junD mRNA levels are higher in postmeiotic round spermatids and residual bodies/cytoplasts than in meiotic pachytene spermatocytes. An additional junD transcript of about 1.6 kb is detected in postmeiotic cells. Analyses of polysomal and nonpolysomal RNAs prepared from isolated testicular cells indicate that in early meiotic cell types the junD transcript is more efficiently loaded onto polysomes than in later cell types. In summary, the pattern of expression of junD differs from that of junB and c-jun during spermatogenesis most notably in that 1) junD mRNA levels do not increase following dissociation of testicular cells and 2) in contrast to the nearly undetectable levels of junB and c-jun mRNAs in adult postmeiotic testicular cells, high levels of junD mRNAs are seen. The differential expression of these three jun transcripts during development of the male gonad suggests a complex transcriptional regulatory role for the jun family of protooncogenes during spermatogenesis.
Effects of micro-structure on the stress concentration at a spherical cavity

Abstract In this paper the boundary-value problem for the stress concentration at a spherical cavity in a field of isotropic tension is solved within the framework of Mindlin's theory of an elastic continuum with a deformable micro-structure. It is found that the stress concentration factor is moderately larger than the 3/2 of classical elasticity for a wide range of material properties and ratios of radius of cavity to a length parameter of the material—with a critical ratio, nearly independent of the remaining material properties, for which the stress concentration factor is a maximum.
A Review of “They Saved the Crops: Labor, Landscape, and the Struggle Over Industrial Farming in Bracero-Era California”

With They Saved the Crops, Don Mitchell, historical geographer from Syracuse University, has produced a thoroughly researched and clearly written book about California's agricultural landscape duri...
Human germline gene therapy reconsidered.

This paper reevaluates the notion of human germline gene therapy (HGLGT) in light of developments in biomedicine, biotechnology, and ethical and policy analysis. The essay makes the following key points. First, because the distinction among "therapy," "prevention," and "enhancement" is not clear in human genetics, "gene therapy" is an inadequate descriptor of the process and goals of germline genetic alterations. The alternate use of the phrase "human germline genome modification" (HGLGM) could avoid a misleading label. Second, procedures that could be construed as genetic "enhancement" may not be as morally problematic as some have supposed, once one understands that the boundaries between therapy, prevention, and enhancement are not obvious in genetic medicine. Third, HGLGM might be the medically and morally most appropriate way of avoiding the birth of a child with a genetic disease in only a small range of cases. Fourth, there are still many ethical and scientific problems relating to the safety and e...
A simple and efficient bus management scheme that supports continuous streams

An efficient bandwidth management and access arbitration scheme for an I/O bus in a multimedia workstation is presented. It assumes that a multimedia workstation consists of a number of processing modules which are interconnected by a packet bus. The scheme is efficient in the sense that it allows the bus to support both continuous media transfers and regular random transactions in such a way that continuous streams can meet their real-time constraints independently of random traffic, and random traffic is not delayed significantly by continuous traffic except when traffic load is very high. Implementation guidelines are provided to show that the scheme is practical. Finally, the performance of this scheme is compared with alternative solutions through simulation.
Characterization of allergen-induced bronchial hyperresponsiveness and airway inflammation in actively sensitized Brown-Norway rats

Abstract Bronchial responsiveness to inhaled acetylcholine (ACh) and inflammatory cell recruitment in bronchoalveolar lavage fluid (BALF) were studied in inbred Brown-Norway rats actively sensitized to, and later exposed to, ovalbumin (OA). We examined animals 21 days after initial sensitization at 18 to 24 hours, or 5 days after a single challenge, or after the last of seven repeated exposures administered every 3 days. BALF was examined as an index of inflammatory changes within the lung. Animals repeatedly exposed to OA aerosols had an increased baseline lung resistance and a significant increase in bronchial responsiveness to inhaled ACh compared to control animals at both 18 to 24 hours and 5 days after the last OA exposure. Sensitized animals receiving a single OA aerosol also demonstrated bronchial hyperresponsiveness (BHR) to inhaled ACh ( p R 5 = 0.68; p
A universal DNA extraction and PCR amplification method for fungal rDNA sequence‐based identification

Accurate identification of fungal pathogens using a sequence-based approach requires an extraction method that yields template DNA pure enough for polymerase chain reaction (PCR) or other types of amplification. Therefore, the objective of this study was to develop and standardise a rapid, inexpensive DNA extraction protocol applicable to the major fungal phyla, which would yield sufficient template DNA pure enough for PCR and sequencing. A total of 519 clinical and culture collection strains, comprised of both yeast and filamentous fungi, were prepared using our extraction method to determine its applicability for PCR, which targeted the ITS and D1/D2 regions in a single PCR amplicon. All templates were successfully amplified and found to yield the correct strain identification when sequenced. This protocol could be completed in approximately 30 min and utilised a combination of physical and chemical extraction methods but did not require organic solvents nor ethanol precipitation. The method reduces the number of tube manipulations and yielded suitable template DNA for PCR amplification from all phyla that were tested.
Laser Radar Receiver Using A Digicon Detector

The features of the Digicon detector concept are described and related to the requirements for a direct-imaging laser radar receiver. Recent experimental results on sensitivity and time resolution of a prototype detector are reported. The status of an integrated receiver experiment based on a prototype Digicon detector is reported. Laboratory experiments on the magnification of the electron image to improve the spatial resolution of advanced Digicon detectors are also described.
Characteristics of thermal and flow behavior in the vicinity of discontinuities

Abstract An asymptotic analysis is applied in this work to study the fundamental behavior of thermal and flow fields in the vicinity of a wedge tip. The emphasis is placed on the physical conditions under which the temperature gradient of the flow field becomes singular at the wedge tip. These conditions are found to be sensitive to the thermal conditions imposed on the wedge surfaces. For natural convection problems, it is found that the r -dependencies of the field quantities in the near-tip region are determined by the eigenvalue problem for the temperature field, while the eigen-states for the flow velocities are determined by a boundary value problem. The reverse situation exists for forced convection problems. A detailed discussion is also provided for the extension of the near-tip solutions to more complicated problems in conjunction with the use of finite element methods.
Analysis, Design and Simulation of Capacitive Load Balanced Rotary Oscillatory Array

The high frequency of the rotary clocking technology is often susceptible to implementation parameters such as the variation in the total capacitive load distribution between the rings. SPICE simulations performed on the rotary rings with unbalanced capacitive load distribution show a 30.31% variation in the simulated frequencies across the rings. To address this problem, two novel methodologies called OCLB and SOCLB, are formulated for the optimal capacitive load balancing and sub-optimal capacitive load balancing with minimized wirelength, respectively. SPICE simulations performed with OCLB show 0.30% variation in the simulated frequencies across the rings. Further, SOCLB results in an average wirelength improvement of 69.24% over OCLB with a relatively balanced capacitive load distribution. SPICE simulations performed with SOCLB show 2.40% variation in the simulated frequencies across the rings, improved significantly over the 30.31% variation of the unbalanced case.
Depolarization of white light by a birefringent crystal. II. The Lyot depolarizer

An earlier paper [ S. Lu A. P. Loeber , J. Opt. Soc. Am.65, 248– 251 ( 1975)] investigated the depolarization of white light on passage through a birefringent crystal because of the unequal phase retardation of different wavelengths. Assuming the incident light to be completely polarized with the spectral-power distribution of a blackbody, the degree of polarization remaining after passage through various crystal thicknesses was determined. This paper extends the result of the earlier study to an analysis of the Lyot depolarizer. Earlier work by Billings [ J. Opt. Soc. Am.41, 966– 975 ( 1941)] considered the general case of two crystal retardation plates of different retardances and orientations to determine what requirements the plates must meet in order to act as a depolarizer. Billings assumed the intensity of the incident light to be independent of wavelength. Despite the different assumptions regarding the spectral-power distribution of the incident light, our investigation agrees with Billings’s conclusions that (1) the crystal retardances of both crystals must be large, (2) the crystal retardances cannot be equal, and (3) the angle between the crystal axes must be 45° for the combination of plates to act as a depolarizer. An additional conclusion by Billings, that the ratio of the two retardances must be an integral, is not indicated by our analysis. Results of our analysis are in qualitative agreement with the experimental work carried out by Billings on several modifications of the usual Lyot depolarizer configuration.
Accelerated chromatin biochemistry using DNA-barcoded nucleosome libraries

A synthetic library of nucleosomes, each with a DNA-barcode characteristic for a defined post-translational modification (PTM), is used to probe PTM-based recruitment and modulation of histone mark readers and writers.
Inhibition of Flavin Adenine Dinucleotide Pyrophosphorylase by Isoriboflavin

RIBOFLAVIN antagonism by some analogues of the vitamin may be attributable to inhibition of one or more of the following : the flavokinase-catalysed conversion of riboflavin to flavin mononucleotide (PMN), the pyrophosphorylase-catalysed conversion of FMN to flavin adenine dinucleotide (FAD), and the coenzymatic activities of FMN and FAD. Isoriboflavin (5,6-dimethyl-9-(1′D-ribityl)isoalloxazine) has been shown to be an effective antagonist to riboflavin in the growing organism1. This analogue has no reactivity in the flavokinase system where it acts neither to inhibit the normal conversion of riboflavin to FMN nor as an artificial substrate to produce an analogue of FMN2,3. However, it was noted that isoriboflavin inhibits the coenzymatic function of FMN with triphosphopyridine nucleotide–cytochrome c reductase from yeast4. More recently, chemically synthesized isoriboflavin-5′-phosphate was shown to be a substrate in lieu of FMN with FAD pyrophosphorylase5 ; a finding which suggested that isoriboflavin might act as an inhibitor to the normal substrate function of FMN with the pyrophosphorylase. This communication presents direct evidence for the inhibition of FAD pyrophosphorylase by isoriboflavin.
Benefit of Constant Momentum Propulsion for Large Delta V Missions -- Applications in Laser Propulsion

Abstract : The authors show that perfect propulsion requires a constant momentum mission as a consequence of Newton's second law. Perfect propulsion occurs when the velocity of the propelled mass in the inertial frame of reference matches the velocity of the propellant jet in the rocket frame of reference. They compare constant momentum propulsion to constant specific impulse propulsion, which, for a given specification of the mission Delta V, has an optimum specific impulse that maximizes the propelled mass per unit jet kinetic energy investment. They also describe findings of more than 50% efficiency for conversion of laser energy into jet kinetic energy by ablation of solids.
Drop testing and finite element simulation of stacked chip scale packages with and without underfill

Drop testing is performed on stacked chip scale packages in eight configurations, including the use of two types of commercially available underfills. Full failure analysis using techniques such as dye penetrant and scanning electron microscopy (SEM) is performed. Corresponding explicit finite element simulations are performed using ANSYSreg LS-DYNA. These simulations are used to determine a suitable damage parameter and consequently, drop test life correlations are constructed. Considerable differences in drop impact reliability between Sn63Pb37 and SAC305 solder are observed.
Genetics of carbohydrate metabolism and growth in Eisenia foetida (Oligochaeta: Lumbricidae)

The heterozygosity of 13 polymorphic loci, encoding 10 enzymes from several pathways in carbohydrate metabolism, was tested for its effect on growth in juvenile manure worms Eisenia foetida (n = 169), raised under stressful (limited food, low moisture) followed by non-stressful (abundant food, high moisture) conditions. The predictive value of heterozygosity on growth was greatly improved by treating each locus separately rather than summing heterozygosity across all loci (multilocus heterozygosity). Under non-stressful conditions, heterozygosity among loci treated separately had no effect on growth rate (F = 1·60; df = 13, 155; NS); whereas under stressful conditions, heterozygosity among loci treated separately had significant and differential effects on growth rate (F = 2·34; df = 13, 155; P< 0·01) with 7 loci contributing to a positive heterozygosity-growth rate correlation (r = 0·235; P< 0·005) and 6 loci contributing to a negative heterozygosity-growth rate correlation (r = −0·202, P < 0·01). Implicated loci could not be easily grouped into specific metabolic pathways. The negative contribution by some loci may arise as a consequence of heterozygote inferiority, linkage disequilibria with positively-contributing loci, or strong selection at that locus.
Journals should lead the way in improving medical press releases.

News stories about medical research influence patients’ beliefs, behaviours and use of healthcare services.1 Yet the quality of news coverage of medical studies is often poor.2 ,3 Many news stories about medical research exaggerate the clinical significance of the findings, fail to report potential harms of new interventions or overlook important study limitations.2 While it is tempting to blame journalists for shoddy medical news coverage, academic researchers, their institutions and journals must share the blame. For scientists, news coverage is an opportunity to frame their research in a favourable light for the public and colleagues. Meanwhile, development and fund-raising exigencies demand that institutions generate public enthusiasm about scientific accomplishments, and medical editors are motivated to maximise the impact of the research published in their journals. Thus, researchers, institutions and journal editors share a common motivation to maximise press coverage of new medical research. Not surprisingly researchers and their institutions commonly collaborate on press releases to promote news coverage of new medical studies, and many journals issue press releases independently.4 Press releases increase the odds that a study will receive news coverage5 and influence the content of eventual press coverage.6 Alarmingly, in the guise of original reporting, many press releases issued by academic institutions appear verbatim on newspapers and websites with nothing to notify readers that the text is …
Structural and functional characterization of a winter malting barley.

The development of winter malting barley (Hordeum vulgare L.) varieties is emerging as a worldwide priority due to the numerous advantages of these varieties over spring types. However, the complexity of both malting quality and winter hardiness phenotypes makes simultaneous improvement a challenge. To obtain an understanding of the relationship between loci controlling winter hardiness and malt quality and to assess the potential for breeding winter malting barley varieties, we structurally and functionally characterized the six-row accession “88Ab536”, a cold-tolerant line with superior malting quality characteristics that derives from the cross of NE76129/Morex//Morex. We used 4,596 SNPs to construct the haplotype structure of 88Ab536 on which malting quality and winter hardiness loci reported in the literature were aligned. The genomic regions determining malting quality and winter hardiness traits have been defined in this founder germplasm, which will assist breeders in targeting regions for marker-assisted selection. The Barley1 GeneChip array was used to functionally characterize 88Ab536 during malting. Its gene expression profile was similar to that of the archetypical malting variety Morex, which is consistent with their similar malting quality characteristics. The characterization of 88Ab536 has increased our understanding of the genetic relationships of malting quality and winter hardiness, and will provide a genetic foundation for further development of more cold-tolerant varieties that have malt quality characteristics that meet or exceed current benchmarks.
Induced pluripotent stem cells: a new revolution for clinical neurology?

Summary Why specific neuronal populations are uniquely susceptible in neurodegenerative diseases remains a mystery. Brain tissue samples from patients are rarely available for testing, and animal models frequently do not recapitulate all features of a specific disorder; therefore, pathophysiological investigations are difficult. An exciting new avenue for neurological research and drug development is the discovery that patients' somatic cells can be reprogrammed to a pluripotent state; these cells are known as induced pluripotent stem cells. Once pluripotency is reinstated, cell colonies can be expanded and differentiated into specific neural populations. The availability of these cells enables the monitoring in vitro of temporal features of disease initiation and progression, and testing of new drug treatments on the patient's own cells. Hence, this swiftly growing area of research has the potential to contribute greatly to our understanding of the pathophysiology of neurodegenerative and neurodevelopmental diseases.
Experimental and raytrace results for throat-to-throat compound parabolic concentrators

Compound parabolic concentrators are nonimaging cone-shaped optics with useful angular transmission characteristics. Two cones used throat-to-throat accept radiant flux within one well-defined acceptance angle and redistribute it into another. If the entrance cone is fed with Lambertian flux, the exit cone produces a beam whose half-angle is the exit cone's acceptance angle and whose cross section shows uniform irradiance from near the exit mouth to infinity. (The pair is a beam angle transformer). The design of one pair of cones is discussed, also an experiment to map the irradiance of the emergent beam, and a raytracing program which models the cones fed by Lambertian flux. Experimental results compare favorably with raytrace results.
Photo-Assisted Wet-Etched III–V Heterostructure Laser Mirrors

We demonstrate the first photo-assisted wet-etched flat-surface mirrors in III-V laser heterostructure having an average reflectance of 0.87 of the ideal cleaved facet reflectance R c independent of crystal orientation. The largest observed reflectance was 0.93R c. These lasers were fabricated using a 532-nm laser source, sulfuric acid, and exposed-metal mask. The lateral waveguiding formed from air-semiconductor interfaces produced an average internal loss of 28/cm (smallest of 14/cm) compared with similar cleaved-mirror dark-etched lasers having 46/cm.
Adaptive Gabor image transformation: application in scientific visualization

This paper addresses the issues of compression and computation efficiency of transform-based image compression methods. Most transform-based compression systems operate based on the assumption that the input images are mostly conventional types of images. We argue that these systems will not perform efficiently in some image domains in which the aforementioned assumption does not hold. We believe an image encoding system must take into consideration the directional and frequency attributes in the input images in order to achieve high encoding quality. We present a novel adaptive approach for image transformation. Experimental results show that for an "unconventional" image, the proposed system produces better image quality than the JPEG at the same bit-rates.
Factors contributing to an increase in duplicate medication order errors after CPOE implementation

Objective To evaluate the incidence of duplicate medication orders before and after computerized provider order entry (CPOE) with clinical decision support (CDS) implementation and identify contributing factors. Design CPOE with duplicate medication order alerts was implemented in a 400-bed Northeastern US community tertiary care teaching hospital. In a pre-implementation post-implementation design, trained nurses used chart review, computer-generated reports of medication orders, provider alerts, and staff reports to identify medication errors in two intensive care units (ICUs). Measurement Medication error data were adjudicated by a physician and a human factors engineer for error stage and type. A qualitative analysis of duplicate medication ordering errors was performed to identify contributing factors. Results Data were collected for 4147 patient-days pre-implementation and 4013 patient-days
Cross-linked forms of the isolated N-terminal domain of the lethal factor are potent inhibitors of anthrax toxin.

The proteins that comprise anthrax toxin self-assemble at the mammalian cell surface into a series of toxic complexes, each containing a heptameric form of protective antigen (PA) plus up to a total of three molecules of the enzymatic moieties of the toxin (lethal factor [LF] and edema factor [EF]). These complexes are trafficked to the endosome, where the PA heptamer forms a pore in the membrane under the influence of low pH, and bound LF and EF unfold and translocate through the pore to the cytosol. To explore the hypothesis that the PA pore can translocate multiple, cross-linked polypeptides simultaneously, we cross-linked LF N , the N-terminal domain of LF, via an introduced cysteine at its N or C terminus and characterized the products. Both dimers and trimers of LF N retained the ability to bind to PA pores and block ion conductance, but they were unable to translocate across the membrane, even at high voltages or with a transmembrane pH gradient. The multimers were remarkably potent inhibitors of toxin action in mammalian cells (20- to 50-fold more potent than monomeric LF N ) and in a zebrafish model system. These findings show that the PA pore cannot translocate multimeric, cross-linked polypeptides and demonstrate a new approach to generating potent inhibitors of anthrax toxin.