cssi/SciSciGPT-SciSciNet huggingface dataset:
Adolescents' differential responses to social media browsing

Browsing Instagram is a daily practice for many teens, yet the relationship between social browsing and psychological well-being remains controversial. Recent research finds that negative social comparisons mediate the relationship between social browsing and ill-being outcomes, such as depression. The current study systematically examined the role of negative comparisons in the relationship between Instagram browsing and affective well-being immediately post-browsing. Teens (n=507) participated in an online survey that included an Instagram browsing experience. Participants were randomly assigned to a highlight reel condition or to one of two browsing interventions designed to reduce affective consequences of comparison. Participants completed the Positive and Negative Affect Scales (PANAS) pre- and post-browsing and reported social comparisons in response to the featured accounts. Regression analyses controlling for baseline emotions indicate that regardless of browsing condition, teens who reported higher levels of negative social comparison had significantly worse post-browsing affect than peers who reported less negative comparison to the stimuli. No main effects of browsing condition were found. However, browsing condition moderated the relationship between social comparison and affective well-being: the interventions reduced post-browsing negative affect for those at higher levels of negative comparison. Results suggest differential responses to both social browsing and social media interventions. Mixed methods study with an experimental design.Negative comparison predicts immediate influence of social browsing on emotions.Adolescents are differentially affected by browsing others' highlight reels.Two interventions reduce the relationship between comparison and negative affect.Awareness of the curated nature of SNSs varies and may serve a protective function.
Safety related label changes for new drugs after approval in the US through expedited regulatory pathways: retrospective cohort study.

Objective To determine if drugs approved through the Food and Drug Administration’s expedited development and review pathways have different rates of safety related label changes after approval compared with drugs approved through standard non-expedited pathways. Design Retrospective cohort study. Setting FDA public records, January 1997 to April 2016. Participants 382 FDA approved drugs. Main outcome measures The number of times a particular safety section of a label (boxed warning, contraindication, warning, precaution, or adverse reaction) was changed during a drug’s time on the market. The relative rate of safety related label changes per year for expedited pathway and non-expedited pathway drugs was compared by forming matched pairs of drugs in the same therapeutic class that were approved within three years of each other. Results Among the 382 eligible new drugs, 135 (35%) were associated with an expedited development or review pathway, and matches were available for 96 (71%). The matched pairs were associated with a total of 1710 safety related label changes during the study period. Expedited pathway drugs were characterized by a rate of 0.94 safety related label changes for each drug per year, compared with 0.68 safety related label changes per year for non-expedited pathway drugs (rate ratio 1.38, 95% confidence interval 1.25 to 1.52). Compared with non-expedited pathway drugs, expedited pathway drugs had a 48% higher rate of changes to boxed warnings and contraindications, the two most clinically important categories of safety warnings (1.48, 95% confidence interval 1.07 to 2.06). A qualitative review of changes to the boxed warning sections revealed that less than 5% (3/67) were changed to describe reduced risks for patients. Conclusions Expedited development and regulatory review pathways can accelerate the availability of new drugs, but drugs approved through these pathways are associated with increased safety related label changes after approval, particularly for the types of changes representing the highest risk warnings. To inform appropriate policy interventions, additional research should explore the causal factors contributing to these different rates.
Nearshore ocean surface current estimation comparison in C-band and KA-band

Remote sensing techniques for estimation of high-resolution (sub-mesoscale) ocean surface currents have been of interest to science community for many years. Different radar techniques have been tried, with the most popular being along track interferometry and direct Doppler analysis measurements. Jet Propulsion laboratory (JPL) has recently developed a new airborne Ka-band Doppler scatterometer (DopplerScatt), designed to simultaneously measure ocean surface vector currents and winds. The first validation of DopplerScatt's surface current measurements was performed by the Applied Physics Laboratory (APL) at University of Washington using the C-band airborne ATI SAR collocated measurements during a joint campaign in September 2016. In this paper, we compare the two radial velocity measurements and use a numerical scattering model to aid in understanding the differences.
Technoference: longitudinal associations between parent technology use, parenting stress, and child behavior problems

Heavy parent digital technology use has been associated with suboptimal parent–child interactions and internalizing/externalizing child behavior, but directionality of associations is unclear. This study aims to investigate longitudinal bidirectional associations between parent technology use and child behavior, and understand whether this is mediated by parenting stress. Participants included 183 couples with a young child (age 0–5 years, mean = 3.0 years) who completed surveys at baseline, 1, 3 and 6 months. Cross-lagged structural equation models of parent technology interference during parent–child activities, parenting stress, and child externalizing and internalizing behavior were tested. Controlling for potential confounders, we found that across all time points (1) greater child externalizing behavior predicted greater technology interference, via greater parenting stress; and (2) technology interference often predicted greater externalizing behavior. Although associations between child internalizing behavior and technology interference were relatively weaker, bidirectional associations were more consistent for child withdrawal behaviors. Our results suggest bidirectional dynamics in which (a) parents, stressed by their child’s difficult behavior, may then withdraw from parent–child interactions with technology and (b) this higher technology use during parent–child interactions may influence externalizing and withdrawal behaviors over time.
USE OF STAPHYLOCOCCUS AUREUS COATED WITH INVASIN DERIVATIVES TO ASSAY INVASIN FUNCTION

Publisher Summary This chapter reveals that the genetic analysis of outer membrane protein function in gram-negative bacteria may be hampered by the inability to achieve proper localization of potentially informative mutant proteins. The technique described allows functional analysis of an outer membrane protein with mutant derivatives, which cannot be properly expressed on the cell surface. The proteins are purified and subsequently attached to the bacterial cell surface, which allows easy manipulation of the final protein coating concentration. The technique is therefore particularly useful in studying the relative ability of a surface-exposed protein that mediates binding to and uptake by eukaryotic cells. The apparent obstacles to this genetic analysis, and the availability of the maltose-binding protein (MBP)-invasin hybrid proteins, led to the design of a new protocol for the analysis of invasin function. By attaching MBP-Inv hybrid proteins to the surface of Staphylococcus aureus , an organism that is not ordinarily able to enter mammalian cells, it is possible to test various C-terminal fragments of invasin for their ability to mediate bacterial uptake using the previously standardized gentamicin protection assay. This approach could be broadly applicable in the analysis of potential adhesins or invasins from a wide range of unrelated organisms.
Elliptic Curve Factorization Using a “Partially Oblivious” Function

Let N = P · R where P is a prime not dividing R. We show how a special class of functions f : Z N → Z can be used to help obtain P given N. The requirements of f are that it be non-trivial and that f (x) = f (x mod P). Such a function does not “see” R. Hence the name partially oblivious.
Education of the physician in child abuse

Child abuse training often mirrors the development of the field of child abuse by focusing on identification and reporting at the expense of other topics. Physical abuse, and recently sexual abuse, have been emphasized, although neglect is more often reported. The training approach should also include information on epidemiologies, treatment, and prevention. A high index of suspicion can be taught by learning to identify specific physical and behavioral patterns of abuse, and discrepancies between history and the child's condition, and developing better interview skills. Physicians need to know reporting laws, what happens to reports in their community, and how to challenge adverse decisions. Characteristics of child abuse treatment and prevention programs should be taught to residents and physicians providing primary care to children. Principles of learning can be used with various methods to present child abuse information and skills. Whether educating medical students, general physicians, or child abuse experts, their level of involvement with child abuse and the key concepts appropriate for that level should be identified before training methods can be selected. Pediatricians can play an active role in assuring that education in child abuse occurs for all physicians. Answers to first set of questions: STEP 1. Probably middle class or higher. 2. Probably at least 5 years old. 3. Children should have at least average verbal and intellectual skills; they may need to be formally tested. 4. Parents should have at least average verbal and intellectual skills. Answers to second set of questions: Childhood Comes First 1. Approximately 1 year in many cases. 2. It should not; it is an individualized program. 3. No, but it should be an emotionally stable individual with good interactive skills and willing to make a substantial time commitment. 4. A wide range can be tolerated, but the coach will have to read if the consumer cannot. Language: en
Flame speed characteristics of turbulent expanding flames in a rectangular channel

Abstract We present results from studies of freely expanding flames in a unique small-scale convective facility for different free-stream initial conditions, characterized by Taylor-Reynolds numbers in the range of R e λ g = 179 − 395 (using the streamwise RMS velocity component and the lateral Taylor-microscale) and an inertial subrange over two decades of wavenumbers. The isotropic, decaying turbulence is generated by an active vane grid. Adding natural gas far upstream, the premixed flow is ignited using Laser Induced Breakdown (LIB) ignition. The evolution of the resulting spherically expanding flames is investigated using qualitative OH-Planar Laser Induced Fluorescence (PLIF). It is shown that trends of flame speeds derived from mean flame radius growth agree well with results from different experimental setups, using a recently developed scaling based on a spectral closure of a thin flame model (Chaudhuri et al., Phys. Rev. E (2011)). Reliable computation of the flame surface density and turbulent flame brush thickness is enabled by the large number of ensembles that can be collected in this type of facility. Trends of these instantaneous statistical quantities are presented and used to further assess the results of time-dependent mean quantities.
Efficient Cytoplasmic Delivery of Antisense Probes Assisted by Cyclized‐Peptide‐Mediated Photoinduced Endosomal Escape

Intracellular delivery and endosomal release of antisense oligonucleotides remain a significant challenge in the development of gene-targeted therapeutics. Previously, noncovalently cyclized TAT peptide (Cyc-TAT), in which the final ring-closing step is accomplished by hybridization of two short complementary γPNA segments, has been proven more efficient than its linear analogues at entering cells. As Cyc-TAT also readily accommodates a binding site, that is, an overhanging γPNA sequence, for codelivery of functional nucleic acid probes into cells, we were able to demonstrate that the overhang-Cyc-TAT penetrated into A549 cells when carrying an anti-telomerase γPNA that specifically reduced telomerase activity by over 97 %. Herein, we report that the cyclized TAT(FAM) can escape endosomes much more efficiently than the linear TAT(FAM) after LED illumination (490 nm). Based on this observation, the endosomal release of overhang-Cyc-TAT(FAM)/anti-telomerase γPNA complex can be greatly enhanced by photoactivation, thus shortening cell treatment time from 60 to 3 h, while keeping the same high efficiency in inhibiting telomerase activity inside A549 cells.
Trajectory-based training enables protein simulations with accurate folding and Boltzmann ensembles in cpu-hours

An ongoing challenge in protein chemistry is to identify the underlying interaction energies that capture protein dynamics. The traditional trade-off in biomolecular simulation between accuracy and computational efficiency is predicated on the assumption that detailed force fields are typically well-parameterized, obtaining a significant fraction of possible accuracy. We re-examine this trade-off in the more realistic regime in which parameterization is a greater source of error than the level of detail in the force field. To address parameterization of coarse-grained force fields, we use the contrastive divergence technique from machine learning to train from simulations of 450 proteins. In our procedure, the computational efficiency of the model enables high accuracy through the precise tuning of the Boltzmann ensemble. This method is applied to our recently developed Upside model, where the free energy for side chains is rapidly calculated at every time-step, allowing for a smooth energy landscape without steric rattling of the side chains. After this contrastive divergence training, the model is able to de novo fold proteins up to 100 residues on a single core in days. This improved Upside model provides a starting point both for investigation of folding dynamics and as an inexpensive Bayesian prior for protein physics that can be integrated with additional experimental or bioinformatic data.
Local Excision: Indications and Techniques

The treatment for rectal cancer continues to evolve. Advances in surgical technique and chemoradiation are decreasing local recurrence and downstaging the disease enough to impact treatment plans. Surgical excision of the primary tumor remains essential for eradication of disease. Local excision is increasing in popularity for its low morbidity and excellent functional results. However, its use is limited by the inability to assess regional lymph nodes and uncertainty of oncologic outcome [1]. Questions remain on who is a candidate, if there is a need for adjuvant treatment in addition to local excision, and how to handle failures of local excision. Careful preoperative staging, patient selection, and multidisciplinary team and patient input is vital for using local excision as curative therapy in appropriate patients.
Scaffolding Applied Learning and Sustainable Development Goals in the Furman University Sustainability Science Program

Abstract The Furman University (Greenville, SC) Sustainability Science Bachelor of Science degree curriculum requires two introductory courses (Environmental Science, Sustainability Science), three...
Review: The Single Life in the Roman and Later Roman World, edited by Sabine R. Huebner and Christian Laes

Sabine R. Huebner and Christian Laes, ed., The Single Life in the Roman and Later Roman World . Cambridge: Cambridge University Press, 2019. 434 pp. ISBN 9781108470170. $130.00. “All the single ladies” will not be surprised nor will their male and gender fluid counterparts: there was never a time in history without persons who lived the single life, however defined. What is surprising is that the single life has received comparatively scant scholarly attention, especially in the premodern period. Indeed, as Christian Laes observes, “sociocultural research on the single life in the Roman empire has been virtually absent so far” (21). Once one considers how to define “the single life,” however, the relative scarcity of scholarly investigation becomes easier to fathom. What is “the single life?” In his detailed and sophisticated introduction to this important volume Christian Laes makes it clear that Christian asceticism is not what is primarily at issue (though it does of course play a role), but rather something akin to “not married and not in a sexual partnership” without a religious motivation to forgo either and while of an age at that allows for both. In other words, many human beings experience such a situation at some point in the course of their life, for example while not yet married or no longer married because of being widowed or divorced. But does that mean they live a single life? After all, they could be part of an extended family; does that count? In short, analyzing the single life in premodern societies such as the Roman and Later Roman world poses significant conceptual and methodological challenges. As Laes points out, even in today's Western industrialized societies that form the basis of his comparative analysis (3–5), the single life encompasses such potentially contradictory elements as “the legal fact of not being married or not being in an exclusive relationship” (whereby being in an exclusive relationship is only sometimes a legal fact); “living alone and the possible …
Erosive Twiddler’s Syndrome: A Severe Case with Externalization of the Pacemaker

Implantable pacemakers have been the mainstay of therapy for patients with severely decreased left ventricular ejection fractions and recurrent arrhythmias, among other cardiac pathology. Twiddler's syndrome (TS) is an uncommon but potentially life-threatening complication of pacemaker therapy, defined as pacemaker malfunction in the setting of device lead dislodgment due to physical manipulation. Traditionally, there are three distinct TS variants (reeling, ratchet and coiling). This case offers evidence of a unique and new variant of TS, severe recurrent erosive subtype with pacemaker externalization.
Transport theory within a generalized Boltzmann equation for multiband wave packets

The authors present a multiband transport theory of thermoelectric currents that relies on a density operator for multiband wave packets, whose dynamics is captured in a generalized equation of motion.
Quantification of High-Temperature Transition Al 2 O 3 and Their Phase Transformations*

High-temperature treatment of γ-Al2 O3 can lead to a series of polymorphic transformations, including the formation of δ-Al2 O3 and θ-Al2 O3 . Quantification of the microstructure in the range where δ- and θ-Al2 O3 are formed represents a formidable challenge, as both phases accommodate a high degree of structural disorder. In this work, we explore the use of an XRD recursive-stacking formalism for the quantification of high-temperature transition aluminas. We formulate the recursive-stacking methodology for modelling of disorder in δ-Al2 O3 and twinning in θ-Al2 O3 and show that explicitly accounting for the disorder is necessary to reliably model the XRD patterns of high-temperature transition alumina. We also use the recursive stacking approach to study phase transformation during high-temperature (1050 °C) treatment. We show that the two different intergrowth modes of δ-Al2 O3 have different transformation characteristics and that a significant portion of δ-Al2 O3 is stabilized with θ-Al2 O3 even after prolonged high-temperature exposures.
RNA-mediated toxicity in C9orf72 ALS and FTD

A GGGGCC hexanucleotide repeat expansion in the first intron of C9orf72 is the most common genetic cause of amyotrophic lateral sclerosis and frontotemporal dementia. Compelling evidence suggests that gain of toxicity from the bidirectionally transcribed repeat expanded RNAs plays a central role in disease pathogenesis. Two potential mechanisms have been proposed including RNA-mediated toxicity and/or the production of toxic dipeptide repeat proteins. In this review, we focus on the role of RNA mediated toxicity in ALS/FTD caused by the C9orf72 mutation and discuss arguments for and against this mechanism. In addition, we summarize how G4C2 repeat RNAs can elicit toxicity and potential therapeutic strategies to mitigate RNA-mediated toxicity.
Joint Scheduling and Power Control for Delay Guarantees in Heterogeneous Cognitive Radios

An uplink multisecondary user (SU) cognitive radio system having average delay constraints as well as an interference constraint to the primary user (PU) is considered. If the interference channels between the SUs and the PU are statistically heterogeneous due to the different physical locations of the different SUs, the SUs will experience different delay performances. This is because SUs located closer to the PU transmit with lower power levels. Two dynamic scheduling-and-power-allocation policies that can provide the required average delay guarantees to all SUs irrespective of their locations are proposed. The first policy solves the problem when the interference constraint is an instantaneous one, while the second is for problems with long-term average interference constraints. We show that although the average interference problem is an extension to the instantaneous interference one, the solution is totally different. The two policies, derived using the Lyapunov optimization technique, are shown to be asymptotically delay optimal while satisfying the delay and interference constraints. Our findings are supported by extensive system simulations and shown to outperform the existing policies as well as shown to be robust to channel estimation errors.
Management of the posterior wall fracture in associated both column fractures of the acetabulum

The primary aim of this study was to compare clinical outcomes in patients with associated both column (ABC) acetabular fractures with fracture of the posterior wall (PW), in which the PW underwent reduction and fragment-specific fixation versus those that were treated with column fixation alone. Secondary aims were to assess PW fracture incidence and morphology, as well as to compare radiographic outcomes including fracture healing and interval displacement of the PW in those that did and did not undergo fragment-specific fixation of the PW. This was a retrospective series of ABC acetabular fractures treated at a single Level I trauma center. Separate fractures of the PW were identified, and associated features were assessed. Associated both column fractures that underwent reduction and fragment-specific fixation of the PW where then compared to ABC fractures with PW involvement that underwent column reconstruction alone. Radiographic and clinical outcomes were compared. Fractures of the PW occurred in 55.7% of ABC fractures and were associated with central displacement of the femoral head. The majority of PW fractures were large and involved the acetabular roof. All PW fractures healed without displacement by 3 months, regardless of whether or not reduction and stabilization was performed. Mid-term outcomes at 1-year were similar regardless of whether or not the PW was reduced and stabilized, with regards to Tonnis grade, Merle d'Aubigne-Postel score, and conversion to total hip arthroplasty. Reduction and fragment-specific fixation of the PW component of ABC acetabular fractures did not improve outcomes in this small comparative study. Posterior wall fractures associated with ABC patterns are frequently large-sized fragments that involve the acetabular roof and are rendered stable after reconstruction of the columns.
Evaluating the effect of a post-processing algorithm in detection of annular fissure on MR imaging

Visualization of annular fissures on MRI is becoming increasingly important but remains challenging. Our purpose was to test whether an image processing algorithm could improve detection of annular fissures. In this retrospective study, two neuroradiologists identified 56 IVDs with annular fissures and 97 IVDs with normal annulus fibrosus in lumbar spine MRIs of 101 patients (58 M, 43 F; age ± SD 15.1 ± 3.0 years). Signal intensities of diseased and normal annulus fibrosus, and contrast-to-noise ratio between them on sagittal T2-weighted images were calculated before and after processing with a proprietary software. Effect of processing on detection of annular fissures by two masked neuroradiologists was also studied for IVDs with Pfirrmann grades of ≤ 2 and > 2. Mean (SD) signal baseline intensities of diseased and normal annulus fibrosus were 57.6 (23.3) and 24.4 (7.8), respectively (p 2, with an apparent increased sensitivity and decreased specificity using predefined image-based human categorization as a reference standard. Image processing improved CNR of annular fissures and detection rate of annular fissures. However, further studies with a more stringent reference standard are needed to assess its effect on sensitivity and specificity.
Large-$N_c$ constraints for elastic dark matter-light nucleus scattering in pionless effective field theory

Recent proposals for the use of light nuclei as dark matter direct detection targets necessitate a strong theoretical understanding of the nuclear physics involved. We perform relevant calculations for dark matter-light nucleus scattering in a combined pionless effective field theory and large-$N_c$ expansion, where $N_c$ is the number of quark colors. We include a general set of one-nucleon currents that have been used in other effective theories, as well as novel two-nucleon contact currents. First, we obtain constraints for the relative sizes of the dark matter couplings to the one- and two-nucleon currents through the large-\Nc expansion. Then, we use these constraints to make predictions for the relative sizes of spin-dependent and spin-independent cross sections for dark matter scattering off of a nucleon, a deuteron, a triton, and helium-3.
Millon Behavioral Health Inventory: Its utility in predicting physical function in patients with low back pain

The present study evaluated the use of psychologic measures, in particular, the relatively new Million Behavioral Health Inventory (MBHI), in predicting change in physical function of chronic low back pain patients undergoing a functional restoration program. The first 134 consecutive patients completing this program were assessed. Results demonstrated that various clinical scales of the MBHI were predictive of improvement in physical function. In addition, various scales enabled discrimination between patients who completed the program and those who prematurely dropped out. Although this inventory shows promise in helping to predict response to treatment, no single psychologic test can reliably be used as the sole predictor in clinical cases.
Jackpot Justice and the American Tort System: Thinking Beyond Junk Science

In 2007 the Pacific Research Institute released a report, "Jackpot Justice: The True Cost of America's Tort System," that is widely available on the internet. The conclusion of the report is that America's tort system costs $865.37 billion annually, amounting to an "annual price tag, or 'tort tax' for a family of four in terms of costs and foregone benefits" of $9,827. As our report will demonstrate, the conclusions of Jackpot Justice are without scientific merit and present a very misleading picture of the American tort system and its costs.Research on the tort system's efficiency, its fairness and other issues are legitimate topics of empirical inquiry and are to be encouraged. Indeed, the three authors of this report have collectively devoted many years to empirical investigation of the tort system. (Summary biographies of the authors appear at the end of this report.) However, when research findings, such as those in Jackpot Justice, are disseminated to the public and are intended to have effects on legislative and other public policy institutions, they deserve careful scrutiny, including close examination of the validity of the theoretical underpinnings, the methodologies used, the quality of the data reported, and the conclusions that are drawn from the analyses. Scrutiny of Jackpot Justice in this way reveals many flaws that strongly contradict the conclusions that the Pacific Research Institute authors have made.Our report has four sections. In Section I we draw attention to Jackpot Justice's misleading claims about its scientific approach to the data and the claimed scholarly consensus that underlies their research. In section II we present a detailed critique of their analyses and conclusions. In Section III we address a missing part of the equation that Jackpot Justice uses to speculate about the "tort tax": the cost of torts to victims. The analyses we present in this section are simply illustrative of the kind of data that would be needed to assess the costs and benefits of the tort system. We do not claim that our rough estimates are accurate, but they help to point to the reasoning flaws in Jackpot Justice. In section IV we offer examples that are intended to counter general public misperceptions of three topics that are central targets of those who argue the tort system is unfair: medical malpractice litigation, products liability, and punitive damages. These examples are intended to put a concrete face on some of the technical issues discussed in the preceding sections of our report.A central message of our report is that the tort system needs to be viewed in terms of its benefits as well as its costs. Moreover, our report draws attention to the social and political choices involved in policies directed toward the goals of promoting responsibility, preventing injuries and compensating victims of negligence. We do not contend that the American tort system is flawless. But it is important to be aware that the corporate critics of the tort system frequently use the same tort system in their disputes with other businesses.
Invariants of conformal Laplacians

The conformal Laplacian D = d*d + (n - 2)s/4(n - 1), acting on functions on a Riemannian manifold Mn with scalar curvature s, is a conformally invariant operator. In this paper we will use D to construct new conformal invariants: one of these is a pointwise invariant, one is the integral of a local expression, and one is a nonlocal spectral invariant derived from functional determinants. We begin in §1 by describing the Laplacian D and its Green function in the context of conformal geometry. We then derive a basic formula giving the variation in the heat kernel of D. This formula is strikingly simpler than the corresponding formula for the ordinary Laplacian given by Ray and Singer [15]. The heat kernel of D has an asymptotic expansion k(t, x, x) ~ (4πt)~n/2Σak(x)tk. In §2 we prove that a(n_2)/2 is a pointwise conformal invariant of weight -2, i.e. it satisfies a(n_2)/2(x; λ2g) = λ2a(n_2)/2(x\ g), where g is the metric and λ is any smooth positive function. In particular, this shows the existence of a nontrivial locally computable conformally invariant density naturally associated to the conformal structure of an even dimensional manifold. The key to the proof is to consider the parametrix of the Green's function, which is obtained from the heat kernel by an integral transform. One finds that a(n_2)/2 occurs as the coefficient of the first log term in this parametrix, and its conformal invariance then follows directly from the conformal invariance of the Green's function. In §3 we show that / an/2 is a global conformal invariant (the calculations in §4 show that it is not a pointwise invariant). The proof is a direct calculation of the invariant of / an/2 using equation (1.10).
Dangers of Brain-o-vision

Does Consciousness Cause Behavior? . Susan Pockett, William P. Banks, and Shaun Gallagher, Eds. . MIT Press, Cambridge, MA, 2006. 372 pp. $50, £32.95. ISBN 9780262162371. Approaching the link between consciousness and behavior from a variety of perspectives, the contributors consider recent findings from psychology and neuroscience, philosophical suppositions, and legal, social, and moral implications.
A regional metabolic contrast method for the study of brain pathology

The use of 2-deoxyglucose for the measurement of regional cerebral glucose utilization in both animals and humans has gained widespread application. An attractive aspect of regional brain glucose metabolism is its apparent correlation with functional activity in neurons. Animal experiments suggest that this relationship is altered in brain lesions and that barbiturate anesthesia may be employed in the detection of brain regions where uncoupling of metabolism and neuronal function has occurred. A functional metabolic contrast technique is described that will permit determination of regional metabolism that is specifically attributable to neuronal activity. Areas of potential clinical application are discussed.
Microfluidic devices for culturing primary mammalian neurons at low densities

Microfluidic devices have been used to study high-density cultures of many cell types. Because cell-to-cell signaling is local, however, there exists a need to develop culture systems that sustain small numbers of neurons and enable analyses of the microenvironments. Such cultures are hard to maintain in stable form, and it is difficult to prevent cell death when using primary mammalian neurons. We demonstrate that postnatal primary hippocampal neurons from rat can be cultured at low densities within nanoliter-volume microdevices fabricated using polydimethylsiloxane (PDMS). Doing so requires an additional fabrication step, serial extractions/washes of PDMS with several solvents, which removes uncrosslinked oligomers, solvent and residues of the platinum catalyst used to cure the polymer. We found this step improves the biocompatibility of the PDMS devices significantly. Whereas neurons survive for ≥ 7 days in open channel microdevices, the ability to culture neurons in closed-channel devices made of untreated, native PDMS is limited to ≤ 2 days. When the closed-channel PDMS devices are extracted, biocompatibility improves allowing for reliable neuron cultures at low densities for ≥ 7 days. Comparisons made to autoclaved PDMS and native, untreated PDMS reveal that the solvent-treated polymer is superior in sustaining low densities of primary neurons in culture. When neuronal affinity for local substrates is observed directly, we find that axons localize to channel corners and prefer PDMS surfaces to glass in hybrid devices. When perfusing the channels with media by gravity flow, cultured hippocampal neurons survive for ≥ 11 days. Extracting PDMS improves biocompatibility of microfluidic devices and thus enables the study of differentiation of identifiable neurons and the characterization of local extracellular signals.
TechWare: Spoken Language Understanding Resources [Best of the Web]

In this issue, "Best of the Web" focuses on spoken language understanding (SLU), an emerging field in between the areas of speech processing and natural language processing. Since SLU is not a single stand-alone technology, unlike speech recognition or synthesis, it is hard to present a single application. The term spoken language understanding has largely been coined for targeted understanding of human speech directed at machines, although understanding human/human conversations or even human/human/machine interactions are vibrant areas of research. For a more comprehensive survey of SLU tasks, readers are referred to [1].
Carbon dioxide uptake, water relations and drought survival for Dudleya saxosa, the ‘rock live-forever’, growing in small soil volumes

Summary 1 Although many plants grow in rock crevices and other regions of small soil volume, including over 20 000 epiphytic and hemi-epiphytic species, analyses of the actual soil volume occupied, the water availability in that soil, the water-storage capacity in the shoots and underground organs, and the photosynthetic pathway utilized have rarely been combined. 2 Dudleya saxosa (M.F. Jones) Britton and Rose (Crassulaceae), growing in the Sonoran Desert, has very shallow roots that occupied soil volumes averaging only 43 × 10−6 m3 per medium-sized plant. This volume of soil can hold about the same amount of water (10 g) as can be stored in the leaves, corm and roots combined (11 g), but at a sufficiently high water potential for transfer to the plant for less than 1 week after a substantial rainfall. 3 About 80% of the net carbon dioxide uptake by D. saxosa over a 24-h period occurred during the daytime (C3) under wet conditions, the daily total decreasing by 34% and the pattern shifting to nocturnal net CO2 uptake (CAM) after 46 days’ drought. Seventy-seven days’ drought eliminated its daily net CO2 uptake. 4 Stomatal frequency was only 67 mm−2 on the adaxial (upper) surface and twofold lower on the abaxial surface. The cuticle was thick, 34 µm for the adaxial surface. Leaves had 24 mesophyll cell layers, leading to a high mesophyll cell surface area per unit leaf area of 142. 5 The three leaf anatomical features plus utilization of CAM increased net CO2 uptake per unit of water transpired, and helped D. saxosa thrive in a small soil volume, with the underground corm being a major supplier of water to the succulent leaves during 2.5 months of drought. The maximum water-holding capacity of the soil explored by the roots closely matched the maximum water-holding capacity of the plant, reflecting the conservative strategy used by D. saxosa in a stressful semi-arid environment.
Signaling analysis for an all-optical network that uses burst switching

Three signaling schemes are analyzed for an all-optical multiswitch high-speed network implementation that uses burst switching (i.e., connections are established only for the duration of a data burst). Figure 1 shows a representative three-switch network. The throughput and the delay are determined for each scheme, and comparisons are made. This investigation is of interest because important characteristics of all-optical very-high-speed networks were not considered in the design of many existing signaling protocols: the propagation delay is comparable to or may exceed the burst transmission time, and optical buffers are not currently practical.
The regeneration of brachial nerves of contralateral origin into denervated fused newt forelimbs

Previous studies involving the end-to-end fusion of the forelimbs of the adult newt have demonstrated that new limbs can regenerate from the transected ends of proximo-distally reversed limb segments. The limb regeneration could only have been initiated by nerve fibers of contralateral origin. The purpose of the present study is to describe histologically the manner in which nerve fibers of contralateral origin regenerate through the junction of fused limbs into the opposite limb. The first sign of nerve regeneration into the opposite limb was observed at eight days post fusion. The nerves crossed over into the opposite, originally denervated limb in a highly dispersed manner. These nerve fibers eventually aggregated, however, either under the skin or within persisting nerve trunks. By 19 days post fusion the nerve fibers had reached the elbow region of the originally denervated limb and by 25 days they were seen at the most proximal extent of the limb. The diameters of the axons seemed smaller than the diameters of regenerating axons observed in non-fused newt forelimbs.
Fabrication of a novel micron scale Y-structure-based chiral metamaterial: Simulation and experimental analysis of its chiral and negative index properties in the terahertz and microwave regimes.

In this report, we describe the fabrication of a chiral metamaterial based on a periodic array of Y-shaped Al structures on a dielectric Mylar substrate. The unit cell dimensions of the Y-structure are ∼100 μm on a side with 8 μm linewidths. The fabricated Y-structure elements are characterized using scanning electron microscopy (SEM) and atomic force microscopy (AFM). Quantitative elemental analyses were carried out on both the Y-structure, comprised of Al and its oxide, as well as adjacent regions of the underlying mylar substrate using the energy dispersive X-ray spectroscopy (EDS) capability of the SEM. Finite-Difference Time-Domain (FDTD) calculations of the negative index of refraction for a 3D wedge of multiple layers of the 2D metamaterials showed that these metamaterials possess double negative (−μ,−ϵ) electromagnetic bulk properties at THz frequencies. The same negative index of refraction was determined for a wedge comprised of appropriately scaled larger Y-structures simulated in the microwave region. This double negative property was confirmed experimentally by microwave measurements on a 3D wedge comprised of stacked and registered Y-structure sheets. Microsc. Res. Tech., 2007. © 2007 Wiley-Liss, Inc.
Can LCF be topped? Flat lattice models of typed lambda calculus

G. Plotkin (1977) examined the denotational semantics of LCF (essentially typed lambda calculus with arithmetic and looping). He showed that the standard Scott semantics is computationally adequate but not fully abstract; with the addition of some parallel facilities, it becomes fully abstract, and with the addition of an extential operator, denotationally universal. This treatment is extended to Scott models built from flat lattices rather than flat cpo's. It is found that no extension of LCF can be denotationally universal. A fully abstract extension based on Godel numbering and synthetic analysis is the best that can be achieved. Operators defined by LCF-style rules cannot give fully abstract language. It is shown that Plotkin's program can be carried out for a nonconfluent evaluator. >
Dynamic docking of cytochrome b5 with myoglobin and alpha-hemoglobin: heme-neutralization "squares" and the binding of electron-transfer-reactive configurations.

Intracomplex electron transfer (ET) occurs most often in intrinsically transient, low affinity complexes. As a result, the means by which adequate specificity and reactivity are obtained to support effective ET is still poorly understood. We report here on two such ET complexes: cytochrome b5 (cyt b5) in reaction with its physiological partners, myoglobin (Mb) and hemoglobin (Hb). These complexes obey the Dynamic Docking (DD) paradigm: a large ensemble of weakly bound protein−protein configurations contribute to binding in the rapid-exchange limit, but only a few are ET-active. We report the ionic-strength dependence of the second-order rate constant, k2, for photoinitiated ET from within all four combinations of heme-neutralized Zn deuteroporphyrin-substituted Mb/αHb undergoing ET with cyt b5, the four “corners” of a “heme-neutralization square”. These experiments provide insights into the relative importance of both global and local electrostatic contributions to the binding of reactive configurations...
A system for ultrasonically imaging the human heart in three dimensions.

Abstract A hardware and software system capable of collecting and storing three-dimensional time-varying ultrasonic data is described. Display capabilities consist of two dimensional cross-sectional views at selected points, orientations, and times. The accuracy of the system was verified by imaging stationary objects of known shape. An in vivo human heart was then isonified. Adjacent cross sections were viewed to find a cross section containing heart structures. This cross section was then viewed throughout the heart cycle. Important structures can be clearly identified and their anatomical relationship observed during all phases of the heart cycle.
Incorporating Lesbian and Gay Issues Into Counselor Training: A Resource Guide

In order for counselors to facilitate the growth of their lesbian and gay clients, they must be familiar with and become sensitive to the special needs of this population. However, most counselors and counselor trainees have had little exposure to these needs. One way of increasing their awareness and sensitivity is to incorporate lesbian and gay issues into counselor training programs. The focus of this article is to present a limited list of strategies and resources that can be used to supplement materials in traditional courses in counselor training so as to better prepare counselors for dealing with lesbian and gay clients.
Informing the Patient and the Community About the Implications of Primary Cesarean

Education of patients and the community should begin with an acknowledgment of the increase in primary and secondary morbidity and mortality associated with the initial cesarean delivery. Women with cesarean birth have a higher rate of rehospitalization for various indications, including surgical site infections. The direct cost for cesarean-related surgical site infection alone is in the tens of millions of dollars. It is important for patients to appreciate risk factors that lead to an increase the risk for primary cesarean, such as obesity, and medical comorbidities. Education on these factors allows in some instances for preconception interventions that can potentially lower the risk for primary cesarean. The obstetrician and the maternal fetal medicine subspecialist have an obligation to focus on evidence-based obstetrical practices that can lead to a more acceptable primary cesarean rate for the obstetrical population. Patient and community awareness can contribute to the promotion of this expectation in obstetrical practice.
The pharmacology of seizures induced by sensitization with low intensity brain stimulation.

Abstract Daily low-intensity electrical stimulation of selected brain sites causes seizures to gradually develop. Because the limbic area is particularly susceptible to both the sensitization phenomenon and psychotropic drugs, we evaluated several classes of centrally-active agents for activity against these seizures. For comparative purposes, seizures elicited from the amygdala and a nonlimbic site, the sensorimotor cortex, were tested. Rats with chronically-implanted electrodes were stimulated for one min each day with a 50-μA, 60-Hz current. Initially, no overt effects occurred; but eventually seizures wereestablished. Once the seizures stabilized, drug effects on seizure duration were measured. Antidepressive drugs were more potent in suppressing amygdaloid-elicited seizures than cortically-evoked seizures. Both antianxiety and antiepileptic drugs exerted nonselective blockade but the antianxiety agents were extremely potent in comparison to the antiepileptics. Representative neuroleptic drugs failed to block the seizures, even at doses completely debilitating the animals. Stimulants prolonged the seizures but the activity was weak. Thus, the low-intensity brain stimulation (LIBS) procedure has proved to be not only an interesting phenomenon, but one that responds differentially to various classes of CNS drugs.
Approximating the minimum strongly connected subgraph via a matching lower bound

We present a 3/2-approximation algorithm for the problem of finding a minimum strongly connected spanning subgraph in a given directed graph. As a corollary we obtain a 3/2-approximation algorithm for the more general minimum equivalent digraph problem. The performance of our algorithm is measured against a lower bound obtained from a simple matching problem. The performance guarantee is optimal with respect to the lower bound.