cssi/SciSciGPT-SciSciNet huggingface dataset:
Racial Position Segregation in Intercollegiate Football: Do Players become more Racially Segregated as they Transition from High School to College?

This study revisits the issue of racial position segregation or racial “stacking” in intercollegiate football. Estimating a probit model, we examine the impact that a player’s race has on the probability of him changing positions when he moves from high school to the collegiate ranks. Descriptive statistics of our data reveal significant evidence that racial position segregation is widespread in high school football. The data also offers much information about which players are likely to change positions and the positions that they are likely to switch to when transitioning from high school to college. Most notably, our probit results reveal that African American high school quarterbacks and white high school running backs are significantly more likely to change positions in college than their white and African American counterparts, respectively. Thus, while other positions do not appear to become more racially segregated as players transition from high school to college, the quarterback and running back positions do appear to become significantly more racially segregated.
Staging of esophageal cancer by EUS: staging accuracy revisited.

Background EUS plays an important role in the preoperative staging of esophageal cancer. Recent data have called into question the staging accuracy of EUS, particularly in patients with early disease. Objective Our goals were to assess our institution's EUS staging accuracy by experienced endosonographers in a contemporary cohort of patients encompassing a wide range of disease stages and to assess staging accuracy after dilation of malignant strictures. Design Retrospective data review. Setting Single tertiary care center. Patients and Interventions A total of 42 patients with esophageal cancer undergoing preoperative EUS staging without neoadjuvant chemoradiotherapy between December 1999 and December 2004 were evaluated. Main Outcome Measurements EUS T and N stage sensitivity, specificity, positive predictive value, negative predictive value, and accuracy. Results EUS accurately predicted T stage in 76% of cases and N stage in 89% of cases. Staging accuracy for T3 versus T1 and T2 disease and for N0 versus N1 disease was not significantly different. In 11 cases, malignant strictures required dilation, with 6 tumors being passable post dilation. Post dilation, T staging accuracy was 80% in impassable tumors and 100% in passable tumors, and N staging accuracy was 100% in the passable tumors. Limitations Relatively small number of patients. Conclusions EUS accurately predicts T and N stage in patients with a range of disease stages. EUS provides good staging accuracy after dilation of malignant strictures regardless of whether full tumor traversal post dilation is possible.
The Importance of Mentoring Programs to Women’s Career Advancement in Biotechnology

Mentoring programs provide benefits to mentors, proteges, and organizations, but not all organizations have such programs in place. In those that do, women’s exclusion from informal networks limits their visibility and, in turn, their chances of acquiring a mentor. This poses a barrier to women’s career advancement, as does the absence of female role models at senior executive levels. The biotechnology industry provides a context in which many women have penetrated the glass ceiling and reached the upper echelons of their organizations. The unstructured and dynamic nature of most biotechnology companies, along with the presence of women at the top levels of the organization, make an appropriate context for the implementation of formal mentoring programs to facilitate women’s upward mobility.
Direct evaluation of aeroacoustic theory in a jet

Aeroacoustic theory is applied to low-Mach (M = 0.08) cold jets, focusing on motion at scales which allow the assumption that the entire jet diameter is acoustically compact. The primary result is that the measured sound field directivity of vortex ring pairing in circular jets is similar to that predicted by the theory: a stationary axisymmetric lateral quadrupole. It is also shown that pairing of purely axisymmetric coherent structures is not the dominant sound source in low-Mach-number jets and that vortex asymmetry must be an essential aspect of the vortex motions which produce noise in such jets.
THE DEATH OF READING

Not, you will note, The Death of the Book, The Demise of the Novel, or The End of Western Civilisation As We Know It, or any of the other apocalyptic forecasts that have accompanied the onset of the Digital Revolution. I simply want to say that while all of those other forecasts may (or may not) be true, the central change that this new industrial revolution will bring is a radical alteration in the relationship between the Reader and the Word. If we define the business of reading as the ability to absorb argument or narrative developed serially through the interlinking of sentences, paragraphs and pages of text clothed in the authority of being gathered together in a single binding called a book, then this form of reading will become an arcane pursuit (addicts will doubtless form private clubs to pursue the hobby by 2050: ScreenRead will have arrived).
Understanding the link between moisture dynamics and microbial activity in mobile dunes

Barchan dunes in southeastern Qatar are relentlessly pushed by northwesterly, shamal, winds. This research aims to understand whether a synergy between moisture retention and microbial growth could be exploited to stop them from upsetting natural habitat as they pass. These mobile dunes in Qatar also constitute a unique test area in which to study mechanisms of desertification. After characterizing the behavior and shape of the dune field west of Umm Said, we developed unique instruments for detecting humidity in hyper-arid environments. Using those, we measured diurnal variations in temperature and humidity beneath the dune, as well as fluxes of carbon dioxide through the surface. We also recorded temperature and humidity from a probe initially buried on the dune's avalanche face, emerging 15 months later on its windward face. In the laboratory, we measured effective diffusion, permeability and activity of its sands. By inserting an artificial rippled porous surface in our wind tunnel, we recorded how winds can induce a flow of air within porous sands, thus facilitating moisture and dust intake. Metagenomic analysis of DNA extracted from two dunes revealed that the dune microbial communities were dominated by bacteria from the actinobacteria and firmicutes phyla. Consistent with the known metabolic capacity of these phyla, in silico assessment of the metabolic potential of the dune microbial community suggests that is dominated by heterotrophic bacteria, with surprising few genes for photosynthesis being detected. Other genes, however, were detected that may prove useful in dune stabilization efforts such as urease, and in biotechnology applications such as antibiotic biosynthesis. We succeeded in adapting cultivation independent methods for quantifying viable microbes directly from the sand and in culturing microbes found on individual sand grains. Analysis of the metabolic potential of these isolates is ongoing.
Residual stress model for CaF2

Nanoindentation tests and finite element analysis that considers elastic-mesoplastic deformation for single crystals were used to investigate the mechanical properties of CaF2 under spherical indentation. The goal was to gain a better understanding of microfractures and crystalline anisotropy and their effect on the surface quality of CaF2 during manufacturing. In this analysis, indentations of the three main crystallographic planes (100), (110), and (111) were studied and compared to examine the effects of crystalline anisotropy on the load–displacement curves, surface profiles, contact radius, spherical hardness, stress distributions, and cleavage at two stages, namely at the maximum indentation load and after the load had been removed. Our model results were compared with experimental observation of surface microroughness, subsurface damage, and material removal rate in grinding of CaF2.
Public Discourses About Teenage Pregnancy: Disruption, Restoration, and Ideology

Two recent incidents in the United States generated a wealth of public discourses about a particular reproductive health issue: adolescent childbearing. As the media, political pundits, and private citizens pondered the meaning of these events, they expressed viewpoints, explanations, and possible solutions in mass-mediated outlets. We examined the discourses communicated in such outlets to understand how public discussion of teenage pregnancy reveals ideological assumptions about reproductive health, ideal family forms, and the expected life course.
Ventral tegmental oxytocin induces grooming.

Bilateral microinjection of oxytocin (OXY) into the ventral tegmental area (VTA) of rat brain produced a significant increase in grooming behaviors at doses from 100 pg to 400 ng. Sites in the caudal region of the VTA were sensitive to lower doses of OXY than sites in the rostral region of the VTA. The time course of action of OXY in the grooming paradigm indicated onset beginning immediately after injection, and termination at 60–75 minutes after injection. Comparison of OXY-induced grooming in male, female, and ovariectomized, estrogen-treated female rats showed no differences in potency for OXY among these groups, suggesting that the grooming effects of OXY are not regulated by sex steroids. Analysis of locomotor activity in rats microinjected with OXY 200 ng bilaterally into the caudal VTA revealed that OXY had no effect on ambulatory locomotion, suggesting that this peptide may activate neurons within the VTA which mediate grooming but not locomotion. The OXY receptor antagonist, [Pen1, pMePhe2, Thr4, Orn8]-OT, blocked OXY-induced grooming when both were simultaneously microinjected into the VTA. The dopamine D-2 receptor antagonist, haloperidol, and the D-1 receptor antagonist, SCH 23390, when microinjected into the VTA five minutes before microinjection of OXY into the VTA, did not block OXY-induced grooming, suggesting that OXY is not working through a dopamine autoreceptor on the VTA neurons. Systemic pretreatment with haloperidol and SCH 23390 effectively blocked grooming induced by OXY in the VTA, suggesting that OXY is directly stimulating OXY receptors on VTA neurons to release dopamine at postsynaptic sites regulating grooming behaviors.
Correlation between NMR spectral parameters of nucleosides and its implication to the conformation about the glycosyl bond

Analyses of high resolution proton and carbon NMR spectra of a series of guanine nucleosides in DMSO have revealed a near linear correlation between the chemical shift of the H2, atom of the sugar moiety and the vicinal coupling constant 3JC4-H1'. This unexpected result provides evidence that the variations in the glycosyl torsion angle between nucleosides in solution are less that those which have previously been reported in crystals and it is an experimental basis for analyzing the syn and anti populations from chemical shift and coupling constant data.
Scripture as Guru in the Sikh Tradition

The study of the Sikh scripture, the Adi Granth, is quite useful in understanding the general notion of ‘scripture’ as a cross-cultural phenomenon. In fact, the study of a text as scripture is not only concerned with its textual problems, the reconstruction of its history, the formation of the canon, and its contextual meaning, but also with its ongoing role in the cumulative tradition of a religious community, both as a normative source of authority and as a prodigious living force. Perceived from this angle the reception of the Adi Granth as Guru by the Sikh community is highly significant.
Lamb-Mössbauer factors as a local probe of floppy modes in network glasses

Abstract The temperature dependence of the Lamb-Mossbauer factor, f(T), in a solid provides the first inverse, 〈 1 ω 〉 , and second inverse, 〈 1 ω 2 〉 , moments of the vibrational density of states. In network glasses, these moments serve as local probes of low-frequency vibrational excitations, such as floppy modes, and provide a means to establish the rigidity percolation threshold. Lamb-Mossbauer results on prototypical chalcogenide glasses (GexSe1−x) correlate well with those of Raman scattering, inelastic neutron scattering and Mossbauer hyperfine structure experiments in indicating that the rigidity percolation threshold occurs near 〈r〉c = 2.46(4). These observations provide experimental support for predictions of the Phillips-Thorpe constraint theory, when provision is made for a small but finite concentration of broken bond-bending constraints around chalcogen sites.
The 3′ terminus of the large ribosomal subunit (“17S”) RNA from hamster mitochondria is ragged and oligoadenylated

The 3'-terminal sequence of the large ribosomal subunit ("17S") RNA of hamster mitochondria has been examined by means of oligonucleotide fingerprint analysis of 3' end-labeled samples. Patterns from partial acid or alkaline hydrolysates indicated marked heterogeneity and suggested an array of termini that included GGUUAOH, AnAOH and AnGOH (where n is about 10). Patterns from samples subjected to exhaustive digestion with ribonucleases T1 plus A, or with each separately, confirmed these inferences, and strikingly demonstrated the existence of oligoadenylated families of 3'-terminal sequences. Under the assumption that the oligoadenylate was added posttranscriptionally, these results indicated that the 3'-terminal transcribed moieties consist of variants of YAGGUUOH. Counting from the last U, we inferred that many such sequences end at U1 and G4, while smaller numbers end at G3 and A5; and that major sites of oligoadenylation occur at U1 and G4, and a minor site occurs at A5. This novel combination of imprecise termination of transcription or "sizing" of transcripts, and variable addition of adenylate residues, is discussed with regard to the mechanism of expression of the mammalian mitochondrial ribosomal RNA genes.
Uniform Temperature Cylindrical Furnace

A method of calculating the variation in temperature along the axis of a uniformly wound cylindrical furnace is given. Methods have been suggested for obtaining a predetermined field of temperature, including uniform temperature in a furnace. The following has been shown.
Creep resistance of the directionally solidified ceramic eutectic of Al2O3/c-ZrO2(Y2O3): experiments and models

The creep resistance of the directionally solidified ceramic eutectic of Al 2 O 3 /c-ZrO 2 (Y 2 O 3 ) was studied in the temperature range of 1200-1520 °C both exprimentally and by mechanistic dislocation models. The topologically continuous majority phase of Al 2 O 3 , has a nearly perfect growth texture in the [0001] direction and encapsulates the minority c-ZrO 2 (Y 2 O 3 ) phase in a variety of morphologies. This encapsulated minority phase too has a close to <1 1 2) growth texture, regardless of morphology. The two phases are separated by close to coherent and well structured interfaces. The creep of the eutectic in its growth direction exhibits an initial transient that is attributed to stress relaxation in the c-ZrO 2 (Y 2 O 3 ) phase, but otherwise in steady state shows many of the same characteristics of creep in sapphire single crystals with c-axis orientation. The creep strain rate of the eutectic has stress exponents in the range of 4.5-5.0 and a temperature dependence suggesting a rate mechanism governed by oxygen ion diffusion in the Al 2 O 3 . While required TEM evidence is still incomplete, finite element analysis of stress distribution in the two phases and a detailed dislocation model of the creep rate indicate that much of the nano-scale encapsulated c-ZrO 2 (Y 2 O 3 ) is too small to deform by creep so that the major contribution to the recorded creep strain is derived from the diffusion-controlled climb of pyramidal edge dislocations in the Al 2 O 3 phase. The evidence suggests that the climbing dislocations in Al 2 O 3 must repeatly circumvent the c-ZrO 2 (Y 2 O 3 ) domains acting as dispersoids resulting in the stress exponents larger than 3. The creep model is in very good agreement with the experiments.
Globalization and deregulation of legal services

Abstract In a series of influential papers, Ribstein, 2010 , Ribstein, 2011 delivered his vision about the future of the market of legal services, including legal education and the structure of law firms. In this paper, I review current trends at the global level and discuss the extent to which globalization of legal services has in fact promoted or induced deregulation.
Physiological regulation of acute inflammation by A2A adenosine receptor

The activation of Gs-coupled A2A adenosine receptor on the surface of immune cells increases levels of immunosuppressive cyclic AMP and leads to inhibition of secretion of proinflammatory cytokines, which, in turn, results in downregulation of acute inflammation. The role of A2A receptors in the regulation of inflammation appears to be non-redundant. Small doses of inflammatory stimulus induce high levels of proinflammatory cytokines and extensive tissue injury in A2A receptor-deficient (Adora2a−/−) mice leading to death due to unregulated inflammatory damage. The gene-dose effect of A2A receptor expression in T cells suggests that there are no spare A2A receptors and that the final outcome of immune cell activation may be dependent on the number of these receptors on the individual immune cells. Heterozygous (Adora2a+/−) mice express decreased levels of A2A receptor on the surface and adenosine-induced cAMP-accumulation of immune cells was lower than in wild-type. Thus, the number of A2A receptors determines cAMP response to adenosine and may pre-determine the immunosuppressive role of adenosine. Drug Dev Res 64:172–177, 2005. © 2005 Wiley-Liss, Inc.
Generation of Propagating Bessel Beams Using Leaky-Wave Modes

The generation of Bessel beams using a leaky radial waveguide is presented. The radial waveguide consists of a capacitive sheet over a ground plane. It supports an azimuthally invariant leaky-wave mode whose normal electric-field component is a truncated, zeroth-order Bessel function. The annular spectrum and nondiffractive extent of the Bessel beam is clearly linked to the complex wavenumber of the leaky-wave mode. The fields inside the radial waveguide are derived using classical vector potential techniques. A vector approach is employed to avoid paraxial approximations of earlier works and the associated limitations on shaping the Bessel beam. Design rules are provided to synthesize a desired propagating Bessel beam. A simple coaxial feed is proposed for the radial waveguide and its input impedance is derived analytically. The analytical results are also validated numerically. The proposed structure and design procedure can be used for generating arbitrary zeroth-order propagating Bessel beams at microwave and millimeter-wave frequencies.
LCAT DNA Shearing

We present a novel method to fragment DNA by using lateral cavity acoustic transducers (LCATs). DNA solution is placed within a microfluidic device containing LCATs. The LCATs cause microstreaming, which fragments DNA within the solution without any need for purification or downstream processing. The LCAT-based DNA fragmentation method offers an easy-to-use, low-cost, low-energy way to fragment DNA that is amenable to integration on microfluidic platforms to further automate DNA processing. Furthermore, the LCAT microdevice requires less than 10 µL of sample, and no external equipment is needed besides a piezoelectric transducer.
UL54-Null Pseudorabies Virus Is Attenuated in Mice but Productively Infects Cells in Culture

The pseudorabies virus (PRV) UL54 homologs are important multifunctional proteins with roles in shutoff of host protein synthesis, transactivation of virus and cellular genes, and regulation of splicing and translation. Here we describe the first genetic characterization of UL54. We constructed UL54 null mutations in a PRV bacterial artificial chromosome using sugar suicide and lambdaRed allele exchange systems. Surprisingly, UL54 is dispensable for growth in tissue culture but exhibits a small-plaque phenotype that can be complemented in trans by both the herpes simplex virus type 1 ICP27 and varicella-zoster virus open reading frame 4 proteins. Deletion of UL54 in the virus vJSdelta54 had no effect on the ability of the virus to shut off host cell protein synthesis but did affect virus gene expression. The glycoprotein gC accumulated to lower levels in cells infected with vJSdelta54 compared to those infected with wild-type virus, while gK levels were undetectable. Other late gene products, gB, gE, and Us9, accumulated to higher levels than those seen in cells infected with wild-type virus in a multiplicity-dependent manner. DNA replication is also reduced in cells infected with vJSdelta54. UL54 appears to regulate UL53 and UL52 at the transcriptional level as their respective RNAs are decreased in cells infected with vJSdelta54. Interestingly, vJSdelta54 is highly attenuated in a mouse model of PRV infection. Animals infected with vJSdelta54 survive twice as long as animals infected with wild-type virus, and this results in delayed accumulation of virus-specific antigens in skin, dorsal root ganglia, and spinal cord tissues.
Assessing motor function in young children with transcranial magnetic stimulation.

Abstract Objective Accurate noninvasive assessment of motor function using functional MRI (fMRI) and magnetoencephalography (MEG) is a challenge in patients who are very young or who are developmentally delayed. In such cases, passive mapping of the sensorimotor cortex is performed under sedation. We examined the feasibility of using transcranial magnetic stimulation (TMS) as a motor mapping tool in awake children younger than 3 years of age. Methods Six children underwent motor mapping with TMS while awake as well as passive sensorimotor mapping under conscious sedation with MEG during tactile stimulation (n = 5) and fMRI during passive hand movements (n = 4). Results Stimulation of the motor cortex via TMS successfully elicited evoked responses in contralateral hand muscles in 5 patients. The location of primary motor cortex in the precentral gyrus identified by TMS corresponded with the postcentral location of the primary sensory cortex identified by MEG in 2 patients and to the sensorimotor cortex identified by fMRI in 3 children. In this cohort, we demonstrate that TMS can illuminate abnormalities in motor physiology including motor reorganization. We also demonstrate the feasibility of using TMS-derived contralateral silent periods to approximate the location of motor cortex in the absence of an evoked response. When compared to chronological age, performance functioning level appears to be better in predicting successful mapping outcome with TMS. Conclusions Our findings indicate that awake TMS is a safe alternative to MEG and fMRI performed under sedation to localize the motor cortex and provides additional insight into the underlying pathophysiology and motor plasticity in toddlers.
Mental health services: use and disparity among diverse college students

Objective: In this empirical study, the authors examined (1) actual use of counseling for emotional problems and (2) the assumptions that ethnicity, sex, social class, and psychological distress are associated with disparities in use of counseling. Participants: Participants were 1,773 diverse undergraduate students at an urban university. Methods: The authors collected data via self-administered questionnaires between 1999 and 2005; they used a cross-sectional correlational research design, including analysis of variance statistical procedures. Results: Students' level of counseling use (10%) was similar to that estimated for a national college sample. Students reporting higher levels of distress were more likely to use counseling; however, more than three-fourths of students who reported clinically significant levels of distress had not received counseling. Conclusions: The authors observed no disparities in use of mental health services in terms of sex, ethnicity, and socioeconomic status.
Interfacial friction of thin PDMS network films

This study focuses on developing dry, surface-tethered polymeric lubricant coatings capable of significantly decreasing friction and wear of nano- and micrometer scale machines. Vinyl-terminated polydimethylsiloxane chains are spin-coated with a crosslinking agent and platinum catalyst onto silicon wafers functionalized with a self-assembling monolayer containing reactive vinyl groups. Lateral force microscopy (LFM) measurements employing a bead probe are used to quantify the coefficient of friction (COF) and adhesion characteristics of the PDMS-SAM surface tethered networks. The combined polymer network and SAM layer manifest extremely low friction coefficients, μ = 4 × 10−3, which is nearly one order of magnitude lower than the friction coefficient of the bare silicon substrate. The lowest friction forces are measured using silicon substrates covered with nanometer thick, peroxide crosslinked PDMS networks; though poorly crosslinked, these networks display COFs as much as ten-times lower than a solitary SAM coating layer. Micrometer thick end-linked optimal networks also manifest attractive interfacial friction properties, with COFs approximately three times larger than the thinner, imperfect networks. These observations are discussed in terms of the structure of the polymer networks and the role of adhesion forces on interfacial friction. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 1773–1787, 2008
The therapeutic potential of class I selective histone deacetylase inhibitors in ovarian cancer

Epithelial ovarian cancer remains the deadliest gynecologic malignancy. Despite advances in treatment, new approaches are needed. Histone deacetylases (HDACs) are a family of enzymes that regulate gene expression by removing acetyl groups from lysine residues on histones and non-histone proteins. Inhibition of HDACs with small molecules has led to the development of HDAC inhibitors (HDACi) that are in clinical use, primarily for hematologic malignancies. Although clinical trials with HDACi as single agents in solid tumors have been disappointing, data from independent labs and recent work by our group show that class I selective HDACi have potent anti-tumor effects in preclinical models of ovarian cancer. This review summarizes the role of HDACs in ovarian cancer and the potential niche for selective class I HDACi, particularly HDAC3 in ovarian cancer therapy.
Landscape context matters: local habitat and landscape effects on the abundance and patch occupancy of collared lizards in managed grasslands

The distribution and abundance of a species may be simultaneously influenced by both local-scale habitat features and the broader patch and landscape contexts in which these populations occur. Different factors may influence patch occupancy (presence–absence) versus local abundance (number of individuals within patches), and at different scales, and thus ideally both occupancy and abundance should be investigated, especially in studies that seek to understand the consequences of land management on species persistence. Our study evaluated the relative influences of variables associated with the local habitat patch, hillside (patch context), and landscape context on patch occupancy and abundance of the collared lizard (Crotaphytus collaris) within tallgrass prairie managed under different fire and grazing regimes in the northern Flint Hills of Kansas, USA. Using a multi-model information-theoretic approach that accounted for detection bias, we found that collared lizard abundance and occupancy was influenced by factors measured at both the local habitat and landscape scales. At a local scale, collared lizard abundance was greatest on large rock ledges that had lots of crevices, high vegetation complexity, and were located higher up on the hillslope. At the landscape scale, collared lizard abundance and occupancy were both higher in watersheds that were burned frequently (1–2 year intervals). Interestingly, grazing only had a significant effect on occupancy and abundance within less frequently burned (4-year burn interval) watersheds. Our results suggest that, in addition to the obvious habitat needs of this species (availability of suitable rock habitat), land-management practices have the potential to influence collared lizard presence and abundance in the grasslands of the Flint Hills. Thus, mapping the availability of suitable habitat is unlikely to be sufficient for evaluating species distributions and persistence in such cases without consideration of landscape management and disturbance history.
Community's Response to Substance Misuse The East Los Angeles Halfway House for Felon Addicts

This is a report on some salient findings regarding the establishment and operation of an experimental Halfway House program for persons with a history of narcotic usage who had been released on parole from prison. The halfway house program concentrated its treatment regimen upon a therapeutic community model which placed considerable emphasis upon group therapy and counseling. Increased arrest rates for narcotics use, possession, and sale in California following World War 11, as well as a dramatic rise in drug-related crime, led to the innovation of a series of state programs, one of which was the NarcoticTreatment Control program for felon addicts. The program provided for reduced caseloads of 15, 30, and 45 men, with Nalline testing to detect usage, plus a short-term reconfinement unit for persons discovered to be using drugs. The latter two conditions were instituted for the Halfway House as well, with the caseload size stabilized at 30 men for each parole agent.
Evidence for equilibrium gels of valence-limited particles

We explore the formation and structure of gels produced from solutions of the aromatic dipeptide derivative molecule fluorenylmethoxycarbonyl–diphenylalanine (Fmoc–FF) in dimethyl sulfoxide (DMSO). Mixing these solutions with water results in the self-assembly of Fmoc–FF molecules into space-filling fibrous networks, exhibiting mechanical properties characteristic of gels. Using confocal fluorescence microscopy, we observe the gel transition in situ and find that, upon the addition of water, the solution undergoes a rapid transition to a non-equilibrium state forming ∼2 μm spheres, followed by the formation of fibers 5–10 nm in diameter, nucleating at a sphere surface and expanding into the solution as the remaining spheres dissolve, extending the network. The gel aging process is associated with the network becoming increasingly uniform through apparent redissolution/reaggregation of the Fmoc–FF molecules, corresponding to the observed increase in the elastic modulus to a plateau value. We demonstrate that this increase in uniformity and elastic modulus can be expedited by controlling the temperature of the system, as well as that these gels are thermally reversible, further indicating that the system is in equilibrium in its fibrous network state. X-ray scattering information suggests that the packing of the molecules within a fiber is based on π–π stacking of β-sheets, consistent with models proposed in the literature for similar systems, implying that each particle (molecule) possesses a limited number of interaction sites. These observations provide experimental evidence that these low molecular weight gelator molecules can be considered valence-limited “patchy” particles, which associate at low enough temperature to form equilibrium gels.
Power comparison of throughput optimized IC busses

Globally asynchronous bus designs are considered theoretically attractive for saving power. In this work we design and compare asynchronous and synchronous busses in 0.13um and 0.10um technologies based on bus-wires that are optimized for throughput per unit channel area. At high frequency the synchronous data bus wire power exceeds that for the asynchronous design due to the higher latch-repeater power. In contrast, the asynchronous bus control power is greater than the local synchronous clock power until a sufficient number of bus lines share the control line. Based on a reasonable switching activity factor for the lines (e.g. /spl sim/15%), however, a shared control line can be considered as switching continuously for 32 bits or more, while the bus is being utilized. The power benefits of asynchronous, therefore, are questionable for applications such as globally asynchronous locally synchronous (GALS) methodologies. Moreover, the distinction between asynchronous and synchronous is marginal if we further consider a synchronous control line with a local pulse-generation circuit to drive half-latch repeaters in the data bus path.
Prediction-error driven learning: the engine of change in cognitive development

Summary form only given. Since the introduction of powerful connectionist learning procedures such as back propagation, our group has been studying the use of such procedures as a mechanism for cognitive development. The models can be viewed as capturing Piaget's idea that development is essentially an experience driven process, dependent of the adjustment of schemas to assimilate disparities between expectations and observations. Among the issues that have been addressed with these models are the following: (1) Is an initial naive domain theory required to allow a learner to interpret experience in a given domain? (2) Why does learning appear to occur in stages, punctuated by plateaus? (3) what does it mean to be 'ready to learn'? (4) Is it necessary to start small in learning, and if so when and why? (5) Why are there critical or sensitive periods in learning; why is it sometimes easier to learn when a system is 'young' or inexperienced?.
The embedded discontinuous Galerkin method : Application to linear shell problems

A new discontinuous Galerkin method for elliptic problems which is capable of rendering the same set of unknowns in the final system of equations as for the continuous displacement-based Galerkin method is presented. Those equations are obtained by the assembly of element matrices whose structure in particular cases is also identical to that of the continuous displacement approach. This makes the present formulation easily implementable within the existing commercial computer codes. The proposed approach is named the embedded discontinuous Galerkin method. It is applicable to any system of linear partial differential equations but it is presented here in the context of linear elasticity. An application of the method to linear shell problems is then outlined and numerical results are presented.
Parallel simulated annealing by generalized speculative computation

Simulated annealing is known to be highly sequential due to loop carried dependencies. This report present a new approach to parallel simulated annealing, called generalized speculative computation (GSC). The GSC can execute n iterations in parallel while maintaining the same decision sequence as a sequential version. To demonstrate the performance of GSC, we implement 100 to 500 city Traveling Salesman Problem on the AP1000 massively parallel machine. Actual experimental results demonstrate that the GSC is highly effective for the given problem as we obtain a nearly 20-fold speedup for the initial temperature of 1 on 100 processors. >
Rolling Out Zotero Across Campus as a Part of a Science Librarian's Outreach Efforts

As more information proliferates online, researchers often struggle to find an efficient way of managing their bibliographic data. Zotero presents an attractive alternative to proprietary citation tools as it is free, user-friendly, Web 2.0-compatible, and can be easily integrated with websites, online databases, catalogs, and repositories. Besides a brief review and comparative analysis of Zotero, the article highlights the science librarian's efforts to promote Zotero to students and faculty members in the College of Natural Sciences and Mathematics. While his initial outreach attempt was to target the scientific community on campus, the author found other library advocates within other campus units. Training writing tutors at the Learning Assistance Center turned out to be a very effective means of creating more library advocates and Zotero evangelists across campus.
Lighting the world's treasures: Approaches to safer museum lighting

A strategy is reported to optimize lighting to reduce photochemical degradation of works of art and archival documents. The strategy revolves around improving luminous efficiency of the spectral profile to exclude light which doesn't contribute to brightness or color perception, while also trying to maintain color rendering. The work focuses on Old Master Drawings and designing filters for illuminants, but is applicable to the broad range of art and archival documents and the direct design of lighting without filters such as LED. A filter profile is identified which seems to be beneficial, or at worst neutral for all pigments measured. Underlying principles are identified: (1) The best luminous efficiencies arise from multiple band illuminants, and also improves as color rendering is sacrificed. (2) Protection of an object even late in its damage life can significantly extend its remaining life. (3) Protection of an object early in its life can possibly abate some of the light induced damage it may experience across its life, so early intervention in light protection may be advised. This report further goes on to suggest approaches to further enhance the protection, including tailoring the spectral dependence of appearance change. © 2010 Wiley Periodicals, Inc. Col Res Appl, 2010
A numerical solution of laminar forced convection in a heated pipe subjected to a reciprocating flow

Abstract A numerical solution is presented for laminar forced convection of an incompressible periodically reversing flow in a pipe of finite length at constant wall temperature. It is found that the four parameters that govern the heat transfer characteristics for the problem under consideration are the kinetic Reynolds number Reω, the dimensionless oscillation amplitude Ao, the length to diameter ratio LID, and the Prandtl number of the fluid. The numerical results show that annular effects also exist in the temperature profiles near the entrance and the exit of the pipe during each half cycle at high kinectic Reynolds numbers. Typical phase shifts between temperature and axial velocity at selected locations are illustrated. The averaged heat transfer rate is found to increase with both the kinetic Reynolds number and the dimensionless oscillation amplitude but decrease with the length to diameter ratio. A correlation equation of the space time averaged Nusselt number for air in terms of the three similarity parameters, Reω, Ao and LID is obtained.
Dynamic speculative precomputation

A large number of memory accesses in memory-bound applications are irregular, such as pointer dereferences, and can be effectively targeted by thread-based prefetching techniques like Speculative Precomputation. These techniques execute instructions, for example on an available SMT thread context, that have been extracted directly from the program they are trying to accelerate. Proposed techniques typically require manual user intervention to extract and optimize instruction sequences. This paper proposes Dynamic Speculative Precomputation, which performs all necessary instruction analysis, extraction, and optimization through the use of back-end instruction analysis hardware, located off the processor's critical path. For a set of memory limited benchmarks an average speedup of 14% is achieved when constructing simple p-slices, and this gain grows to 33% when making use of aggressive optimizations.
Shortest Rectilinear Paths among Weighted Obstacles

We consider a rectilinear shortest path problem among weighted obstacles. Instead of restricting a path to totally avoid obstacles we allow a path to pass through them at extra costs. The extra costs are represented by the weights of the obstacles. We aim to find a shortest rectilinear path between two distinguished points among a set of weighted obstacles. The unweighted case is a special case of this problem when the weight of each obstacle is +∞. By using a graph-theoretical approach, we obtain two algorithms which run in O(n log2 n) time and O(n log n) space and in O(n log3/2 n) time and space, respectively, where n is the number of the vertices of the obstacles.
Parameter estimation and segmentation of noisy or textured images using the EM algorithm and MPM estimation

Presents a new algorithm for segmentation of noisy or textured images using the expectation-maximization (EM) algorithm for estimating parameters of the probability mass function of the pixel class labels and the maximization of the posterior marginals (MPM) criterion for the segmentation operation. A Markov random field (MRF) model is used for the pixel class labels. The authors present experimental results demonstrating the use of the new algorithm on synthetic images and medical imagery. >
A Self-Biased Operational Transconductance Amplifier in 0.18 micron 3D SOI-CMOS

We report on the design fabrication and testing of a wide range transconductance amplifier fabricated in the 0.18 mum MIT Lincoln Labs 3D SOI-CMOS process. The amplifier is designed to operate in subthreshold and employs self-biased cascode transistors to minimize the bias lines transversing the 3 tiers in the technology
Selective enhancement of associative learning by microstimulation of the anterior caudate

Primates have the remarkable ability to rapidly adjust or modify associations between visual cues and specific motor responses. Whereas little is known as to how such adjustments in behavioral policy are implemented, recent learning models suggest that the anterior striatum is optimally positioned to have a role in this process. We recorded from single units and delivered microstimulation in the striatum of rhesus monkeys performing an associative learning task. Caudate activity during reinforcement was closely correlated with the rate of learning and peaked during the steepest portion of the learning curve when new associations were being acquired. Moreover, delivering microstimulation in the caudate during the reinforcement period significantly increased the rate of learning without altering the monkeys' ultimate performance. These findings suggest that the caudate is responsible for implementing selective adjustments to the 'associative weights' between sensory cues and motor responses during learning, thus enhancing the likelihood of selecting profitable actions.
Demonstration of a universal surface DNA computer

A fundamental concept in computer science is that of the universal Turing machine, which is an abstract definition of a general purpose computer. A general purpose (universal) computer is defined as one which can compute anything that is computable. It has been shown that any computer which is able to simulate Boolean logic circuits of any complexity is such a general purpose computer. The field of DNA computing was founded in 1994 by Adleman's solution of a 7-bit instance of the Hamiltonian path problem. This work, as well as most of the subsequent experimental and theoretical investigations in the area, focused primarily upon the solution of NP-complete problems, which are a subset of the larger universal class of problems. In the present work a surface DNA computer capable of simulating Boolean logic circuits is demonstrated. This was done by constructing NOR and OR gates and combining them into a simple logic circuit. The NOR gate is one of the universal gates in Boolean logic, meaning that any other logic gate can be built from it alone. The circuit was solved using DNA-based operations, demonstrating the universal nature of this surface DNA computing model.
Appendix B: Backprojection and Filtered Backprojection

This chapter contains sections titled: Introduction Backprojection Filtered Backprojection ]]>
The evolutionary turnover of recombination hot spots contributes to speciation in mice

Meiotic recombination is required for the segregation of homologous chromosomes and is essential for fertility. In most mammals, the DNA double-strand breaks (DSBs) that initiate meiotic recombination are directed to a subset of genomic loci (hot spots) by sequence-specific binding of the PRDM9 protein. Rapid evolution of the DNA-binding specificity of PRDM9 and gradual erosion of PRDM9-binding sites by gene conversion will alter the recombination landscape over time. To better understand the evolutionary turnover of recombination hot spots and its consequences, we mapped DSB hot spots in four major subspecies of Mus musculus with different Prdm9 alleles and in their F1 hybrids. We found that hot spot erosion governs the preferential usage of some Prdm9 alleles over others in hybrid mice and increases sequence diversity specifically at hot spots that become active in the hybrids. As crossovers are disfavored at such hot spots, we propose that sequence divergence generated by hot spot turnover may create an impediment for recombination in hybrids, potentially leading to reduced fertility and, eventually, speciation.
“Mechanical” Metaphors and Theory Formation: a Cognitive-Historical Analysis of Economic Discourse

Metaphors and categories are an inalienable part of any science. For centuries, mechanical metaphors have been active in shaping economic thought performing their cognitive function. Economists as different as A. Smith and J. Hicks resorted to metaphors not only to name new phenomena (filling vocabulary lacuna), but, what is more important, to make sense of ontologically given parts of economic reality (a heuristic function) and create a cognitive conceptual system, which served as a basis for economic theories (a theory-constructive function). In this article, I will endeavor to analyze why the way of thinking based on mechanical analogies has proved so fruitful in the history of economics. For this purpose, a cognitive-historical model of analysis is used, which allows one to place the emergence of concepts in the 'context of discovery'. I will undertake to examine the ideology underlying mechanical metaphors, their epistemology and interpretative capacity, as well as their theory generating power. One more aspect of research is to see how the development of a science enriches the language itself. The subject matter of the current research is the focal concepts of modern economics such as 'the market', 'the economy', 'the business cycle', etc. Their analysis is based on the works of the leading economists, starting from the the 17 th century. Belonging to different schools of thought, addressing different economic phenomena, they have one thing in common – reliance on mechanical metaphors. DOI: http://dx.doi.org/10.5755/j01.sal.0.27.13744
Localization of Nitrogenase Using Monoclonal Antibodies

At present there exist two theories on the location of nitrogenase in the bacterial cell. The first, reported by Reed et al. (1974), suggested that nitrogenase is associated with a vesicular membrane system called an “azotophore”. More recent research by Haaker and Veeger (1977) suggested no membrane involvement by nitrogenase based on rates of sedimentation. Our approach was to physically localize nitrogenase in the bacterial cell by using monoclonal antibodies and a protein A-gold EM labelling procedure.