cssi/SciSciGPT-SciSciNet huggingface dataset:
Opposing JAK-STAT and Wnt signaling gradients define a stem cell domain by regulating differentiation at two borders.

Adult organisms contain a variety of cells that are routinely replaced using adult stem cells which can generate the cells of a specific tissue. These stem cells are often clustered into small groups, where combinations of chemical signals from nearby cells can encourage each stem cell to divide or ‘differentiate’ into another type of cell. These different signals must somehow balance stem cell division and differentiation to maintain the size and shape of the community. The ovary of an adult fruit fly contains a group of adult stem cells called follicle stem cells, or FSCs for short. FSCs support the continual production of eggs by supplying two types of cell from opposite faces of the stem cell cluster: dividing follicle cells emerge from the back of the cluster and guide late egg development, while non-dividing escort cells come from the front and guide early egg development. Two of the signals that control FSCs are graded over the cluster. JAK-STAT signaling is strongest in the follicle cell territory and gradually declines towards the front, while Wnt signaling is strongest in escort cells and absent from early follicle cells. However, it was unclear how the gradients of these two signals maintain the FSC population and control the formation of follicle and escort cells. To answer this question, Melamed and Kalderon used genetic engineering to modify the strength of these two signals. The experiments measured how this affected the rate at which FSCs divide and are converted into follicle or escort cells. Melamed and Kalderon found that the strength of JAK-STAT signaling dictated division rates, which may explain why the rate cells divide varies across the FSC cluster and escort cells do not divide at all. JAK-STAT signaling also stimulated FSCs to become follicle cells and opposed their conversion to escort cells. Conversely, stronger Wnt signaling favored the production of escort cells and inhibited FSCs from transitioning to follicle cells. This suggests that the relative strength of these two opposing signals helps maintain thecorrect number of FSCs while also balancing the formation of follicle and escort cells. JAK-STAT, Wnt and other signals guide the development of many organisms, including humans, and have also been linked to cancer. Therefore, the principles and mechanisms uncovered may apply to other types of stem cells. Furthermore, this work highlights genetic changes that can allow a mutant stem cell to amplify and take over an entire stem cell community, which may play a role in cancer and other illnesses.
Expanding the thiol–X toolbox: photoinitiation and materials application of the acid-catalyzed thiol–ene (ACT) reaction

The acid-catalyzed thiol–ene reaction (ACT) is a unique thiol–X conjugation strategy that produces S,X-acetal conjugates. Unlike the well-known radical-mediated thiol–ene and anion-mediated thiol-Michael reactions that produce static thioether bonds, acetals provide unique function for various fields such as drug delivery and protecting group chemistries; however, this reaction is relatively underutilized for creating new and unique materials owing to the unexplored reactivity over a broad set of substrates and potential side reactions. Solution-phase studies using a range of thiol and alkene substrates were conducted to evaluate the ACT reaction as a conjugation strategy. Substrates that efficiently undergo cationic polymerizations, such as those containing vinyl functional groups, were found to be highly reactive to thiols in the presence of catalytic amounts of acid. Additionally, sequential initiation of three separate thiol–X reactions (thiol-Michael, ACT, and thiol–ene) was achieved in a one-pot scheme simply by the addition of the appropriate catalyst demonstrating substrate selectivity. Furthermore, photoinitiation of the ACT reaction was achieved for the first time under 470 nm blue light using a novel photochromic photoacid. Finally, using multifunctional monomers, solid-state polymer networks were formed using the ACT reaction producing acetal crosslinks. The presence of S,X-acetal bonds results in an increased glass transition temperature of 20 °C as compared with the same polymeric film polymerized through the radical thiol–ene mechanism. This investigation demonstrates the broad impact of the ACT reaction and expands upon the diverse thiol–X library of conjugation strategies towards the development of novel materials systems.
Tandem aza-Heck Suzuki and carbonylation reactions of O-phenyl hydroxamic ethers: complex lactams via carboamination.

The palladium-catalysed tandem aza-Heck–Suzuki and aza-Heck–carbonylation reactions of O-phenyl hydroxamic ethers are reported. These formal alkene carboamination reactions provide highly versatile access to wide range complex, stereogenic secondary lactams and exhibit outstanding functional group tolerance and high diastereoselectivity.
The transcriptomic signature of obligate parthenogenesis

Investigating the origin of parthenogenesis through interspecific hybridization can provide insight into how meiosis may be altered by genetic incompatibilities, which is fundamental for our understanding of the formation of reproductive barriers. Yet the genetic mechanisms giving rise to obligate parthenogenesis in eukaryotes remain understudied. In the microcrustacean Daphnia pulex species complex, obligately parthenogenetic (OP) isolates emerged as backcrosses of two cyclically parthenogenetic (CP) parental species, D. pulex and D. pulicaria, two closely related but ecologically distinct species. We examine the genome-wide expression in OP females at the early resting egg production stage, a life-history stage distinguishing OP and CP reproductive strategies, in comparison to CP females of the same stage from the two parental species. Our analyses of the expression data reveal that misregulated genes (underdominant and overdominant genes) are abundant in OP isolates, suggesting widespread regulatory incompatibilities between the parental species. More importantly, underdominant genes (i.e., genes with expression lower than both parentals) in the OP isolates are enriched in meiosis and cell-cycle pathways, indicating an important role of underdominance in the origin of obligate parthenogenesis. Furthermore, metabolic and biosynthesis pathways enriched with overdominant genes (i.e., expression higher than both parentals) are another genomic signature of OP isolates.
Optimizing Free-to-Play Multiplayer Games with Premium Subscription

We consider the optimal operating policies of a free-to-play online multiplayer game with premium sub- scription to maximize its lifetime operating profit. Accounting for social-comparison effects between free and premium players, we model the game attracting or losing players with a hybrid of the Bass diffusion model and the replicator equation in evolutionary game theory. Leveraging optimal control theory, we characterize optimal dynamic pricing and advertising policies and show that the developer should prioritize initial growth by aggressively advertising while postponing the introduction of premium subscription, and surprisingly the subscription price may start high and gradually decrease. We further show that in general the developer should foster stronger social-comparison effects, that player matching can be an efficient and effective operational lever to facilitate monetization without inhibiting growth, and that our main findings remain robust when either the developer or players are financially constrained. These findings are potentially instructive for game developers adopting the premium subscription model.
Kinetics and mechanisms of the oxidation of rhenium(V) oxo and thiolato complexes by alkyl hydroperoxides and orthoquinones

12 Introduction 13 Experimental Section 18 Results 19 Discussion 29 Acknowledgment 37 Supporting Liformation 37 References 53
Mixed infections of Bacillus subtilis involving bacteriophage SPO2c 1 .

Abstract The synthesis of ribonucleic acid (RNA) and deoxyribonucleic acid (DNA) was studied in Bacillus subtilis cells mixedly infected with phages SPO2c1 and either SP82 or β22. It was found that cells preinfected 5 min with either β22 or SP82 could not support significant amounts of RNA or DNA synthesis from the genome of superinfecting SPO2c1. Conversely, cells preinfected with SPO2c1 remained susceptible to superinfection even at the midpoint of the latent period. When SP82 was added to cells preinfected 5 min with SPO2c1, the former greatly inhibited the replication and transcription of the SPO2c1, DNA, but if superinfection with SP82 was delayed until the 15th min of the SPO2c1 latent period, RNA and DNA specific for both phages were synthesized. Both viral genomes were transcribed throughout the remainder of the lytic cycle when β22 was added to cells preinfected either 5 or 15 min with SPO2c1. In both the SPO2c1-SP82 and the SPO2c1-β22 mixed infections, the types of phage-specific RNAs synthesized at a given time in the latent period were similar to those synthesized in single infections with each phage. The association of SPO2c1 DNA with the host cell membrane in certain of the doubly infected cells was different from that observed in singly infected cells. In the SPO2c1-SP82 infection, SPO2c1 DNA was not released from the membrane; in the SPO2c1-β22 mixed infections, significantly less SPO2c1 DNA was membrane-bound when β22 was added before SPO2c1. However, binding and release of SPO2c1 DNA was normal in cells infected first with SPO2c1 and then with β22. The synthesis of phage-specific nucleic acids and the binding of phage DNA to the membrane are discussed with respect to dominance relationships among these phages.
Design of an Emotion Profiler Using SNePS

SNePS is being used to implement an emotion profiler which is based on a new emotion theory. The system is designed to read a transcript of an actual doctor/patient conversation and produce a profile of the patient's emotional state. Because conversations are not restricted in topic and patients use words idiosyncratically, the emotion profiler's use of knowledge is limited. This paper describes a design and SNePS implementation which uses domain-independent knowledge to effectively parse and process transcripts.
Chapter 2 Comparative anatomy and physiology of the corticospinal system

Summary The corticospinal tract provides the most direct pathway over which the cerebral cortex controls movement. In rodents and marsupials this influence is exerted largely upon interneurons in the dorsal horn of the spinal gray matter. However, ascending the phylogenetic scale through carnivores and primates, the number of corticospinal axons grows and corticospinal terminations shift progressively toward the interneurons of the intermediate zone and ventral horn, ultimately forming increasing numbers of synaptic terminations directly on the motoneurons themselves. Based on this phylogenetic trend, humans are believed to have more direct corticomotoneuronal synapses than any other species, consistent with observations that humans suffer more extensive loss of motility from lesions of the corticospinal tract than do other mammals. Beyond this phylogenetic trend, studies of the corticospinal system in animals have provided insight into the motor abnormalities that result from corticospinal lesions in humans. Corticospinal lesions impair many functionally related muscles and movements in parallel, both because of the divergent output from single corticomotoneuronal cells to multiple motoneuron pools, and because of the convergent input to different motoneuron pools from large, overlapping cortical territories. Furthermore, the weakness, slowness and inflexible, stereotyped movements that remain after corticospinal lesions reflect the loss of input to spinal interneurons and motoneurons from corticospinal neurons, the discharge frequency of which varies with the force, direction and speed of both gross and fine movements. That these deficits resulting from corticospinal lesions are more prominent in humans than in animals indicates, moreover, that animals make greater use of additional descending pathways to control movement. Animal studies have shown that although the bulk of the corticospinal tract arises from the primary motor cortex, this projection is not the only route via which the brain controls movement. Adjacent areas in the frontal and parietal lobes also contribute axons to the corticospinal tract, as well as having corticocortical connections with the motor cortex. Furthermore, the motor cortex and premotor cortex both project to the red nucleus and to the pontomedullary reticular formation, from which the rubrospinal and reticulospinal tracts arise. However, given the limitations on experimental studies in humans, comparative animal studies of the distributed descending system through which the brain controls movement continue to provide deeper understanding and insight into the deficits resulting from human corticospinal lesions, whether caused by stroke, tumor, multiple sclerosis, trauma or ALS.
The influence of inclusion spacing and microstructure on the

An approach to the ductile fracture of ultra high strength steels has been evaluated. According to this approach the critical crack tip opening displaceent, δ IC , will scale withX 0(R V/R I)| R 0.X 0 is an average inclusion spacing and (R V/R I)| R 0 is the void radius divided by the radius of the inclusion nucleating the void evaluated at the average inclusion size. AF1410 was selected to test this approach because it has exceptionally high fracture toughness on aging at 510 °C and because its toughness varies markedly with aging temperature. The results from this and earlier work showed a linear relationship exists between δ IC andX 0(R V/R I)| R 0 for values of δ IC ranging from about 8 μm to 60 μm. The values of (R V/R I)| R 0 for AF1410 aged at 425 °C and 510 °C differed by a factor of two. Because the yield strengths and work hardening exponents were similar for the two aging temperatures, the difference in (R V/R I)| R 0 was attributed to changes in microstructure. The microstructures at the two aging temperatures differed in type and size of intra-lath carbides. Both the microstructure and inclusion spacing were found to influence the fracture toughness of AF1410. The average inclusion spacing for this heat of AF1410 was the largest of the six steels evaluated with this model. The model suggests that the large inclusion spacing is critical to the high toughness of AF1410 on aging at 510 °C. This large inclusion spacing results not from an unusually low inclusion volume fraction but from a large average inclusion size.
Virtual states and transitions, virtual sessions and collaboration

A key feature of collaboration is having a log of what and how is being done – for private use/reuse and for sharing selected parts with collaborators in today’s complex, large scale scientific/software environments. Even better if this log is automatic, created on the fly while a scientist or software developer is working in a habitual way, without the need for extra efforts. The CAVES (Collaborative Analysis Versioning Environment System) and CODESH (COllaborative DEvelopment SHell) projects address this problem in a novel way, building on the concepts of virtual state and virtual transition to provide an automatic persistent logbook for sessions of data analysis or software development in a collaborating group. Repositories of sessions can be configured dynamically to record and make available in a controlled way the knowledge accumulated in the course of a scientific or software endeavor.
Nasal Anatomy and the Sense of Smell

As a result of the relative sizes of the various compartments in the nasal cavity, the bulk of the airflow is along the floor of the nasal cavity. The percent of airflow directed to the olfactory region (the superior region of the nasal cavity) is about 10%. Structural changes in the nasal cavity can alter airflow pathways and the characteristics of the airflow (e.g. laminar, mixed or turbulent) within nasal compartments. The relationship between the olfactory response and the stimulus is complex and may vary depending on the physiochemical properties of the odor and the rate at which odorants are delivered to the olfactory receptors. Changes in nasal airflow may impact the various olfactory functions (e.g. identification, differentiation) differently. When there is a nasal obstruction, a decline in olfactory ability may not simply be an access problem, since nasal disease can affect olfactory processing at many levels.
Ouabain Reaction with Microsomal (Sodium-plus-Potassium)-Activated Adenosinetriphosphatase

Microsomal (Na++ K+)-activated adenosinetriphosphatase from eel electroplax binds ouabain in a slow reaction. The rate of binding is modified by enzyme ligands, including nucleotides, orthosphosphate, p-nitrophenylphosphate, carbamylphosphate, Mg2+, Na+, and K+. The actions of these ligands on the enzyme were studied by measuring their effects on the initial rate of ouabain binding. The stimulatory actions ATP, ADP, and Pi depend on the formation of enzyme · Mg · phospholigand complexes. Free nucleotides and Pi are inhibitory. Two alternative pathways for ouabain binding are confirmed: (a) Na+-stimulated, ATP-dependent, and (b) Na+-inhibited, Pi-dependent. In addition, it is shown that the Na+-stimulated path may depend on any of the organic phosphate ligands, including p-nitrophenylphosphate, carbamylphosphate and ADP. In contrast, the Na+-inbibited path is supported only by MgHPO4 or free Mg2+. There is evidence for non-identical Na+-binding sites: the [Na]0.5 value for stimulation is 20 mM while that for inhibition is 4 mM. In the presence of both ATP and P1, the Na+-potentiated-ATP path is favored. K+ inhibits both pathways reversibly and exhibits competition with Na+ and with MgHPO4. ATP decreases the enzyme affinity for K+ while Na+ plus ATP increase the affinity for K+. Since the Pi· enzyme complex is observed only in the absence of both Na+ and K+, it is considered a side path not related to the catalytic cycle. The influences of the ligands on ouabain binding may be related to their effects on the enzyme catalytic cycle. There are two general hypotheses for the ligand effects on ouabain reactivity of (Na++ K+)-ATPase. One, proposed by Sen et al. in 1969, is based on the formation of phosphorylenzyme. The observations are also consistent with an alternative hypothesis which is proposed as follows: (a) the enzyme reactivity with ouabain is increased by the formation of an enzyme · Mg · phospholigand complex regardless of whether the enzyme is also phosphorylated, (b) Na+-activated enzyme has increased affinity for the organic phosphates, which may be considered as substrates, and decreased affinity for Pi and free Mg2+, and (c) K+-activated enzyme has decreased affinity for all the ligands.
Spatial temporal and histogram video registration for digital watermark detection

In this paper, we propose a spatial, temporal and histogram (STH) registration algorithm for video sequences. This algorithm is developed based on a frame-level model of the misalignments often introduced by video processing algorithms, such as compression, frame rate conversion or by video capturing. With this model, the STH registration is formulated as a constrained minimization of a matching cost, and it is solved using dynamic programming. In addition, prior information about the application is incorporated in the form of contextual cost. Experimental results on both synthetic and real processed video sequences have shown that the proposed algorithm is effective and robust to a wide range of noises. In addition, we successfully applied this algorithm to digital forensic watermark detection.
Pancreatic Exocrine Dysfunction

The pancreas is a retroperitoneal gland with both endocrine and exocrine functions. Pancreatic endocrine hormones are released by the islets into the circulation where they are essential for the regulation of intermediary metabolism (see Chapter 47). Pancreatic exocrine secretions (pancreatic juice), produced by the concerted action of pancreatic acinar and ductal cells, are delivered into the duodenum where they are essential for normal digestion. Different pancreatic enzymes promote the efficient digestion of complex carbohydrates, lipids, proteins, and other nutrients (Table 44-1). It is noteworthy that many of these digestive enzymes have the potential to digest components of the pancreas itself. Such autodigestion is normally prevented by several mechanisms. For example, many digestive enzymes exist in an inactive (proenzyme) form until they reach the duodenum. Other mechanisms either prevent activation of proenzymes inside the pancreas or inhibit the enzymes if they are inadvertently activated prematurely.
Psychology in Ghana

This article presents a brief overview of the emergence, education and practice of psychology as a profession and academic discipline in Ghana. We begin with a short history about psychology education in Ghana, which could be traced to the offering of courses in counseling and educational psychology in departments of education at the colleges of education. Because the classroom has been used mainly to train psychologists in Ghana, we provide relevant information about how and where to get psychology education in that country. We also highlight the practice of psychology as a formal discipline in Ghana, including specific challenges that are encountered. Psychology has the potential to be more relevant to Ghanaian people if we demonstrate the importance of the application of its principles in their everyday life.
Early organogenesis of the embryonic chick thyroid. I. Morphology and biochemistry.

Abstract Early organogenesis of the embryonic chick thyroid can be separated into five distinct phases. (1) A placode is first recognized at 48 hr in the midventral pharynx. Its cells are compact, undergo extensive blebbing, and possess apical microfilaments. (2) Vesicle formation coincides with the organization of the microfilaments into pronounced bundles with dense midbodies along their lengths. (3) The vesicle detaches from the pharynx, and as the lumen disappears the band of microfilaments dissipates. The primordium now consists of a loose mass of interior cells with a compact surface cell layer. (4) The primordium elongates laterally and divides to form the bilateral glands. (5) After division, mesenchymal and vascular invasion occur constructing the cords which will give rise to follicles. Thyroxine accumulation is first detected with the recognition of the primordium and increases logarithmically until the vesicle begins to detach from the pharynx. Accumulation of hormone then plateaus until invasion occurs and again increases until after hatching. DNA analyses describe a similar profile for cell numbers with a concomitant plateau. Thus, synthesis of thyroid hormones coincides with the appearance of the primordium, is restricted to the primordium, and describes a concerted profile similar to that found in the pancreas (Rutter et al., 1968).
Controls on nitric oxide emissions from tropical pasture and rain forest soils

In field studies, forest soils in the Atlantic Lowlands of Costa Rica emitted greater amounts of nitric oxide (NO) than soils from pastures that had been actively grazed for over 20 years following their conversion from forest. We measured NO production from intact soil cores from these land uses. Laboratory tests using ammonium(NH 4 + ), nitrate (NO 3 − ), nitrite (NO 2 − ), water, and acetylene (C2H2) additions demonstrate a response consistent with field studies.Forest soil cores produced more NO than pasture cores regardless of treatment. In forest soil the response toNH 4 + solution was significantly greater than response to water or an ambient moisture control. Addition of 10 kPa C2H2 caused a marked decrease in NO production in forest soil cores. These responses suggest a nitrification-linked control over NO production. Large and rapid responses toNO 2 − additions suggest that chemical decomposition of this ion may contribute to NO production. Pasture soil cores did not show a significant response to any of the treatments including NO 2 − . Low porosity in the pasture soils may restrict emission of NO produced therein.
Producing Social Capital National Social Movements and Civil Society

This article analyzes the conceptual treatment of national social movement organizations (SMOs) in current debates over civil society and the decline of social capital in the United States. Despite the rapid growth of national organizations since the 1960s, civil society proponents systematically dismiss their relevance. The author argues instead that national SMOs play a critical role in civil society and the production of social capital by providing an infrastructure for collective action, facilitating the development of mediated collective identities that link otherwise marginalized members of society, and shaping public discourse and debate. Theories that exclude this form of citizen participation not only overlook the important ways that social capital and collective identity are constructed by national organizations, but they ultimately promote the continued marginalization of less powerful social groups.
In vitro activity studies of hyperthermal near-infrared nanoGUMBOS in MDA-MB-231 breast cancer cells

A new kind of material called nanoGUMBOS, comprised entirely of cations and anions, has been developed by pairing various functional ions that exhibit fluorescence activity with biocompatible ions, in a process very much akin to that employed in ionic liquid chemistry. In the present study, spectral and biological properties of NIR absorbing nanoGUMBOS were evaluated using electron microscopy, dynamic light scattering, absorbance, thermal imaging, and live/dead fluorescence assays in conjunction with malignant MDA-MB-231 and non-malignant HS-578-BST epithelial human breast cells. The primary focus of this study was to maximize heat generation using NIR laser irradiation and minimize non-specific cytotoxicity using biocompatible constituent ions (e.g. amino acids, vitamins, or organic acids). Concurrently, in order to generate highly responsive nanomaterials for NIR-laser-triggered hyperthermia, optimization of the nanoparticle size, shape, and uniformity was carried out. Evaluation of data from hyperthermal studies of NIR absorbing nanoGUMBOS shows that these materials can achieve temperatures above the threshold for killing cancerous cells. Additionally, in vitro cell based assays demonstrated their promising hyperthermal effects on cancer derived epithelial cells.
Nonionic polysaccharides as calibration standards for aqueous size exclusion chromatography

Abstract Size exclusion chromatography may be used to determine molecular size or mass of solutes. The validity of the method depends on the correct choice of macromolecular standards used to calibrate the chromatographic column. This calibration is an experimental determination of the relationship between the molecular dimensions and the peak migration velocity of the solute, in practice often presented as a semi-logarithmic plot of log(MW) vs elution volume, but more fundamentally expressed as the dependence of for example, the Stokes radius (RS), or the viscosity radius (Rη) on the chromatographic partition coefficient, KSEC. The validity of this calibration rests on the absence of enthalpic interactions between the standards and the stationary phase and the ability to determine the standards' molecular dimensions and/or mass in a nonambiguous way. Nonionic polysaccharides are ideal for this purpose, and furthermore provide an excellent paradigm for studying the role of molecular architecture in the relationship between KSEC and Rη or RS.
Some Input on Input: Two Analyses of Student Response to Expert Feedback in L2 Writing

Despite high interest in second language writers' revision processes, few studies have examined how learners perceive or incorporate expert feedback into their revisions. Combining quantitative and qualitative analyses, this study profiles students' awareness of the functions and influences of expert input in their writing. Data include results of a survey of foreign language and English as a second language writers' beliefs about feedback behaviors known to interact with revision processes. Factor analytic results show that, whereas writers in both groups share certain beliefs about feedback and revision, each group perceives expert response as serving distinct functions. Interview data reveal that instructional practices largely shape learners' expectations concerning the pedagogical goals of written feedback. Although tentative, evidence from these complementary studies supports the claim that insights in foreign and second writing research can be enhanced by a reasoned pairing of methodologies and that such tools can supply teachers with meaningful information.
Patch tests in Sézary syndrome and mycosis fungoides

A retrospective series of 34 patients with the diagnoses of Sezary syndrome, pre-Sezary syndrome, or mycosis fungoides had had patch testing. Of these, 27 had at least 1 positive reaction (11 of 12 with pre-Sezary syndrome, 6 of 10 with Sezary syndrome, and 10 of 12 with mycosis fungoides). The highest average number of positive reactions was observed in patients with pre-Sezary syndrome (4.7 per patient). There was no predominance of positive reactions to any one allergen, but 13 of the 27 patients reacted to a metal allergen. Only 1 of 5 patients who had photopatch testing had a positive result. This retrospective study revealed delayed contact hypersensitivity responses in this group of patients and should serve as a basis for prospective consideration of contact dermatitis factors in patients with mycosis fungoides and Sezary states.
Gaussian light beams in inhomogeneous media.

Vector wave solutions are obtained for the propagation of beams of light in media having slow spatial variations of the gain, loss, or index of refraction. The formalism developed here is applicable to a wide range of problems, and an example considered in detail is the propagation of off-axis beams in lenslike laser materials and optical waveguides. A procedure is also described for the diagnosis of localized dielectric inhomogeneities such as plasmas by means of Gaussian laser beams.
Preferential attack of mitochondrial DNA by aflatoxin B1 during hepatocarcinogenesis

Administration of the hepatic carcinogen aflatoxin B1 to experimental animals results in covalent binding to liver mitochondrial DNA at concentrations three to four times higher than nuclear DNA. The concentration of carcinogen adducts in mitochondrial DNA remains unchanged even after 24 hours, possible because of lack of excision repair. Similarly, mitochondrial transcription and translation remain inhibited up to 24 hours suggesting long-term effects of aflatoxin B1 on the mitochondrial genetic system.
Block Copolymer Nanoparticles as Nanobeads for the Polymerase Chain Reaction

New sequencing technologies based on massively parallel signature sequencing (MPSS) have been developed to reduce the cost of genome sequencing. In some current MPSS platforms, DNA-modified micrometer-scale beads are used to template the polymerase chain reaction (PCR). Reducing the size of the beads to nanoscale can lead to significant improvements in sequencing throughput. To this end, we have assembled polymeric nanobeads that efficiently template PCR, resulting in DNA-decorated "nanobeads" with a high extent of functionalization.
The Mass Media as Political Actors

Television News Coverage of Congress, 1972-92." In Congress, the Press, and the Public, ed. Thomas E. Mann and Norman J. Ornstein. Washington, D.C.: American Enterprise Institute and Brookings Institution. Mann, Thomas E., and Norman J. Ornstein, 1994. "Introduction." In Congress, the Press, and the Public, ed. Thomas E. Mann and Norman J. Ornstein. Washington, D.C.; American Enterprise Institute and Brookings Institution. Miller, Warren, Edie N. Goldenberg, and Lutz Erbring. 1979. "Type-Set Politics: Impact of Newspapers on Public Confidence." American Political Science Review 7:67-84.
LYMPHOCYTOTOXIC ANTIBODIES IN FAMILY MEMBERS OF PATIENTS WITH MULTIPLE SCLEROSIS

Abstract Cold-reactive lymphocytotoxic antibodies were found in sera from 14 of 21 (67%) patients with multiple sclerosis. A significantly (P
Dynamic mechanical properties of poly(vinyl chloride)–xonotlite composite system

The filler effect of xonotlite (6CaO.6SiO2.H2O; needle-shaped) on dynamic mechanical properties, such as storage modulus (E′), loss modulus (E″), and tan δ was studied for the PVC—xonotlite composite system. And the properties of the system containing mechanically or chemically disaggregated particle of xonotlite were compared with those of the system-filled aggregates. The dynamic mechanical properties obviously depends on the dispersion condition of xonotlite particle. The aggregates of xonotlite produces a remarkably high modulus, an increase in Tg, and a decrease in mechanical damping near Tg in the system. On the other hand, the disaggregates, especially the chemical disaggregate one, bring softer or more rubbery properties in these systems. The interaction between matrix and filler was the strongest in the aggregates system and decreases in the order, mechanical disaggregates system, chemical disaggregates system.
The complexity of alcohol drinking: Studies in rodent genetic models

Risk for alcohol dependence in humans has substantial genetic contributions. Successful rodent models generally attempt to address only selected features of the human diagnosis. Most such models target the phenotype of oral administration of alcohol solutions, usually consumption of or preference for an alcohol solution versus water. Data from rats and mice for more than 50 years have shown genetic influences on preference drinking and related phenotypes. This paper summarizes some key findings from that extensive literature. Much has been learned, including the genomic location and possible identity of several genes influencing preference drinking. We report new information from congenic lines confirming QTLs for drinking on mouse chromosomes 2 and 9. There are many strengths of the various phenotypic assays used to study drinking, but there are also some weaknesses. One major weakness, the lack of drinking excessively enough to become intoxicated, has recently been addressed with a new genetic animal model, mouse lines selectively bred for their high and intoxicating blood alcohol levels after a limited period of drinking in the circadian dark. We report here results from a second replicate of that selection and compare them with the first replicate.
A planar reconfigurable polarization antenna

A planar antenna with microsecond-reconfigurable polarization is described. The antenna consists of a sub-array of dual orthogonally fed elements, each rotated with respect to the other. The unique design improves circular polarization (CP) axial ratio and linear polarization (LP) performance. The antenna was fabricated and the measured results are presented, showing good LP (> 15dB) but poor CP (>0.3dB) rejection.
Positron emission tomography of the brain

Positron emission tomography (PET) is a technique of transverse tomographic imaging in which detection of two photons emitted from the annihilation of a positron and an electron is used to reconstruct the distribution of a positron emitting isotope within an object. PET provides the capacity to quantitatively measure the local tissue distribution of a variety of radionuclides that are attached to compounds that distribute according to function. Although this technique has been used to measure multiple functions and receptors within the brain, one of the most widespread uses is the measurement of local cerebral glucose metabolism based on the deoxyglucose method. In this article, the application of PET to clinical disorders such as dementia, brain tumors, psychiatric disease, epilepsy, movement disorders, and stroke as well as to normal states such as aging are examined.
A Case of Disassociation of a Modular Femoral Neck Trunion After Total Hip Arthroplasty

Modular femoral heads offer the advantages of increased intraoperative flexibility through the adjustment of leg length and offset, whereas a modular femoral neck can also allow independent adjustment of femoral anteversion. Despite the potential advantages of hip systems using increased modularity, these component designs also offer a greater number of junctions through which problems may occur. This case demonstrates the potential for dissociation of a Morse taper between a modular femoral neck and stem.
Market Information Processing and Organizational Learning

Our understanding of how organizations process market information can be advanced substantially on the basis of principles derived from models of organizational learning. Accordingly, the author ex...
Antagonism of Apomorphine by Chlorinated Phenothiazines

Induction of the pecking syndrome with apomorphine was attempted in pigeons premedicated with a variety of central nervous system depressants and ataraxics. Of the agents employed, the chlorinated phenothiazines (chlorpromazine, prochlorperazine, and perphenazine) proved most effective in inhibiting the apomorphine-induced response. Hydroxyzine exhibited a lesser but significant degree of inhibition while pentobarbital, morphine, nalorphine, promazine, mepazine, and meprobamate were ineffective in modifying the syndrome. Several of the premedicants (nalorphine, meprobamate, mepazine, and hydroxyzine) were observed to potentiate the ordinarily trivial emesis provoked in pigeons by apomorphine.
Empathy as a cognitive inhibitor of interpersonal aggression

The studies presented in this paper examined empathy, especially perspective taking, as a potential inhibitor of interpersonal aggression. The theoretical rationale for these investigations derived from Zillmann's [(1988): Aggressive Behavior 14: 51–64] cognitive excitation model. Study 1 revealed that dispositional empathy correlates negatively with self-reported aggression and with conflict responses that reflect little concern for the needs of the other party. Empathy also was positively related to constructive responses to interpersonal conflict (i. e., those that do involve concern for the needs of the other party). In Study 2, perspective taking was manipulated with instructions to subjects prior to participation in a reaction-time task designed to measure aggression. When threat was relatively low, subjects who were instructed to take the perspective of the target responded less aggressively than did those who had been instructed to focus on the task. Study 3 examined the effect of dispositional perspective taking on verbal aggression. Threat was manipulated in terms of the combination of provocation and gender of the interactants. As predicted, perspective taking related to aggression inhibition under conditions of moderate threat–for males under low provocation and females under high provocation. These effects were predicted and explained in the context of the cognitive-excitation model. © 1994 Wiley-Liss, Inc.
Catalyst temperature oscillations during partial oxidation of methane

During the partial oxidation of methane over Ni-supported catalysts, oscillations of the catalyst temperature were detected over NiO/SiO2, but not over NiO/Al2O3 and NiO/MgO. Hot spots were observed for all the three Ni-based catalysts, but only for the NiO/SiO2 catalyst were they moving down and up. This movement causes the oscillation of the catalyst temperature and is probably due to the reduction and oxidation of the catalyst by the reactants.
Dynamic Forcing and Mesoscale Variability of Heavy Precipitation Events over the Sierra Nevada Mountains

Abstract The aim of this research is to investigate the causes for an isolated maximum in precipitation that is typically found along the northern half of the Sierra Nevada mountains of California, in the vicinity of Plumas National Forest (PNF), during moderate to heavy precipitation events. Particular attention was paid to the role various mesoscale (i.e., <200 km) terrain features may have played in localizing the precipitation at PNF. Numerical simulations and sensitivity experiments for two cases of heavy precipitation at PNF reveal that the extent to which terrain acts to focus precipitation is case sensitive. In the first case, the upstream flow was characterized by a strong horizontal gradient in wind speed and moisture. This gradient led to differential deflection of airstreams incident to the range and, consequently, localized convergence and enhanced rain rates at PNF. This localized enhancement occurred regardless of whether any terrain variations were present in the simulations or not. The se...
Altered Response of a Human Squamous Cell Carcinoma Cell Line to 1,25-Dihydroxyvitamin D3 after Transfer of a Normal Chromosome 11

Abstract Previous work in our laboratory using functional assays for tumorigenicity identified a tumor suppressor element on human chromosome 11q for the cutaneous squamous cell carcinoma cell line A388.6TG.c2. In this report, we screened a variety of agents for differential effects on A388.6TG.c2 compared to a growth-suppressed chromosome 11 microcell hybrid of A388.6TG.c2. One of the agents, 1,25-dihydroxyvitamin D 3 (1,25(OH) 2 D 3 ; calcitriol), exerted a growth-altering effect on A388.6TG.c2, which formed rounded cell clusters across the surface of the raft by Day 6 of treatment. In contrast, full-length chromosome 11 hybrids of A388.6TG.c2, as well as two other squamous cell carcinoma cell lines (FaDu and A431), when treated with 1,25(OH) 2 D 3 , failed to demonstrate this cell-clumping phenotype. To pursue the hypothesis that the growth suppressor element is involved in altering the response to 1,25(OH) 2 D 3 , we tested microcell hybrids carrying t(X;11) chromosomes lacking large portions of 11q. Although these hybrids, like the parent A388.6TG.c2 cells, demonstrated extensive growth in organotypic cultures, they failed to form cell clusters with 1,25(OH) 2 D 3 treatment. These results suggest that the chromosome 11 element that alters the response to 1,25(OH) 2 D 3 is distinct from the growth-suppressing element. An examination of differentiation marker expression revealed identical patterns of basal and suprabasal markers for A388.6TG.c2 and for a chromosome 11 hybrid with or without treatment with 1,25(OH) 2 D 3 . Finally, characterization of candidate tumor suppressor gene PPP2R1B, which encodes for a subunit of protein phosphatase 2A (PP2A), showed seemingly insignificant alterations by cDNA sequence analysis. Collectively, the data suggest that human chromosome 11 contains two different tumor suppressor elements that may account for the two areas of loss of heterozygosity observed on the long arm of this chromosome.
Stimulation of Kv1.3 Potassium Channels by Death Receptors during Apoptosis in Jurkat T Lymphocytes

Abstract The loss of intracellular potassium is a pivotal step in the induction of apoptosis but the mechanisms underlying this response are poorly understood. Here we report caspase-dependent stimulation of potassium channels by the Fas receptor in a human Jurkat T cell line. Receptor activation with Fas ligand for 30 min increased the amplitude of voltage-activated potassium currents 2-fold on average. This produces a sustained outward current, ∼10 pA, at physiological membrane potentials during Fas ligand-induced apoptosis. Both basal and Fas ligand-induced currents were blocked completely by toxins that selectively inhibit Kv1.3 potassium channels. Kv1.3 stimulation required the expression of Fas-associated death domain protein and activation of caspase 8, but did not require activation of caspase 3 or protein synthesis. Furthermore, Kv1.3 stimulation by Fas ligand was prevented by chronic stimulation of protein kinase C with 20 nm phorbol 12-myristate 13-acetate during Fas ligand treatment, which also blocks apoptosis. Thus, Fas ligand increases Kv1.3 channel activity through the same canonical apoptotic signaling cascade that is required for potassium efflux, cell shrinkage, and apoptosis.
Negative Judgments in and about Semantic Memory.

In the past five years or so, the topic of semantic memory has become a very active area of experimental research. This paper presents a relatively different approach in trying to understand subjects' performance in semantic memory tasks. Several of the major theoretical analyses in this field are discussed first. We raise some interpretive problems with earlier studies, and with these considerations in mind, offer our own method for investigating the semantic memory paradigm and analyzing its data. The study of Collins and Quillian (1969) was instrumental in stirring interest in semantic memory. They proposed that our categorical knowledge was stored in a strict hierarchical fashion. They claimed, for instance, that we have directly stored Collies are dogs and Dogs are mammals but not Collies are mammals. To verify this last fact, a subject would have to retrieve the first two and with these infer the truth of the third. This proposal has been called the cognitive economy hypothesis because it reduces memory requirements to a logical minimum. The
Long-wavelength infrared surface plasmons on Ga-doped ZnO films excited via 2D hole arrays for extraordinary optical transmission

Extraordinary optical transmission (EOT) through highly conductive ZnO films with sub-wavelength hole arrays is investigated in the long-wavelength infrared regime. EOT is facilitated by the excitation of surface plasmon polaritons (SPPs) and can be tuned utilizing the physical structure size such as period. Pulse laser deposited Ga-doped ZnO has been shown to have fluctuations in optical and electrical parameters based on fabrication techniques, providing a complimentary tuning means. The sub-wavelength 2D hole arrays are fabricated in the Ga-doped ZnO films via standard lithography and etching processes. Optical reflection measurements completed with a microscope coupled FTIR system contain absorption resonances that are in agreement with analytical theories for excitation of SPPs on 2D structures. EOT through Ga-doped ZnO is numerically demonstrated at wavelengths where SPPs are excited. This highly conductive ZnO EOT structure may prove useful in novel integrated components such as tunable biosensors or surface plasmon coupling mechanisms.
Multiobjective Evolutionary Computation Approach for Redesigning Water Distribution Systems to Provide Fire Flows

One of the critical public safety roles for water distribution systems (WDS) is suppression of urban fire events. Previous studies have investigated WDS rehabilitation with a major focus on improving reliability by pipe enlargement. However, pipe enlargement can cause water quality problems and place public health at risk during normal operational periods. Thus, a novel approach is required to effectively address the conflicting goals of the WDS: reliable delivery of water during normal and emergency conditions, meeting water quality standards, and finding cost-effective design and rehabilitation options. In this study an evolutionary computation-based multiobjective optimization-simulation framework is developed to design effective mitigation strategies for urban fire events for water distribution systems with three objectives: (1) minimizing potential fire damages, (2) minimizing water quality deficiencies, and (3) minimizing the cost of mitigation. An elitist nondominated sorting genetic algorithm (NSG...
A lunar effect on fertility.

Abstract Analysis of 1968 New York City birth records supports folklore that the moon influences human reproduction. Births vary systematically over a period of 29.53 days, the length of the lunar cycle, with peak fertility at third quarter. The effect is small, but is present in four independent time series of births (male, female, black, white) and remains when weekly variation has been removed. A photic explanation is developed which links rhythmic variation in lunar illumination to the timing of ovulation.