cssi/SciSciGPT-SciSciNet huggingface dataset:
Calcium signaling mediates cold sensing in insect tissues

The ability to rapidly respond to changes in temperature is a critical adaptation for insects and other ectotherms living in thermally variable environments. In a process called rapid cold hardening (RCH), insects significantly enhance cold tolerance following brief (i.e., minutes to hours) exposure to nonlethal chilling. Although the ecological relevance of RCH is well-established, the underlying physiological mechanisms that trigger RCH are poorly understood. RCH can be elicited in isolated tissues ex vivo, suggesting cold-sensing and downstream hardening pathways are governed by brain-independent signaling mechanisms. We previously provided preliminary evidence that calcium is involved in RCH, and here we firmly establish that calcium signaling mediates cold sensing in insect tissues. In tracheal cells of the freeze-tolerant goldenrod gall fly, Eurosta solidaginis, chilling to 0 °C evoked a 40% increase in intracellular calcium concentration as determined by live-cell confocal imaging. Downstream of calcium entry, RCH conditions significantly increased the activity of calcium/calmodulin-dependent protein kinase II (CaMKII) while reducing phosphorylation of the inhibitory Thr306 residue. Pharmacological inhibitors of calcium entry, calmodulin activation, and CaMKII activity all prevented ex vivo RCH in midgut and salivary gland tissues, indicating that calcium signaling is required for RCH to occur. Similar results were obtained for a freeze-intolerant species, adults of the flesh fly, Sarcophaga bullata, suggesting that calcium-mediated cold sensing is a general feature of insects. Our results imply that insect tissues use calcium signaling to instantly detect decreases in temperature and trigger downstream cold-hardening mechanisms.
Evaluation of unconformities in upper jurassic and lower Cretaceous nonmarine deposits, Bighorn Basin, Wyoming and Montana, U.S.A.

Abstract Although unconformities are common in ancient fluvial sequences, their age significance is often difficult to determine. Where absolute age control is lacking, various physical criteria can be used to evaluate the relative duration and significance of major unconformities. In an area which encompasses over 10 6 km 2 of the west-central United States, a major unconformity is inferred to separate the Morrison Formation of Late Jurassic age from overlying Early Cretaceous conglomeratic sandstones. Previous studies have suggested that the disconformity at this contact may represent as much as 40 Ma. However, physical sedimentologic observations of the Morrison Formation and the overlying Cloverly Formation in the Bighorn Basin of Wyoming and Montana do not support this interpretation. Sandstone composition, clay mineralogy and fluvial architecture show gradational and intraformational changes upsection, rather than an abrupt change at the Morrison/Cloverly contact. In addition, scour surfaces are common within each formation and do not necessarily occur at the formation boundary. The results of this study complement recent absolute and relative age dating which suggests that the Morrison Formation is partially of Early Cretaceous (Neocomian) age, and that the overlying Lower Cretaceous conglomeratic sequence (which includes the lower part of the Cloverly Formation) may be older than Aptian and possibly of Late Neocomian age. The upper part of the Morrison Formation and the lower part of the Cloverly Formation may therefore represent continuous, although episodic, deposition of a fluvial system as it evolved through time.
Golgi Structure Correlates with Transitional Endoplasmic Reticulum Organization in Pichia pastoris and Saccharomyces cerevisiae

Golgi stacks are often located near sites of "transitional ER" (tER), where COPII transport vesicles are produced. This juxtaposition may indicate that Golgi cisternae form at tER sites. To explore this idea, we examined two budding yeasts: Pichia pastoris, which has coherent Golgi stacks, and Saccharomyces cerevisiae, which has a dispersed Golgi. tER structures in the two yeasts were visualized using fusions between green fluorescent protein and COPII coat proteins. We also determined the localization of Sec12p, an ER membrane protein that initiates the COPII vesicle assembly pathway. In P. pastoris, Golgi stacks are adjacent to discrete tER sites that contain COPII coat proteins as well as Sec12p. This arrangement of the tER-Golgi system is independent of microtubules. In S. cerevisiae, COPII vesicles appear to be present throughout the cytoplasm and Sec12p is distributed throughout the ER, indicating that COPII vesicles bud from the entire ER network. We propose that P. pastoris has discrete tER sites and therefore generates coherent Golgi stacks, whereas S. cerevisiae has a delocalized tER and therefore generates a dispersed Golgi. These findings open the way for a molecular genetic analysis of tER sites.
Effect of eye blink on the visual evoked response in children

Abstract The frequency of reflex blinking to flash and its effect on the visual evoked response (VER) were studied in thirty-one normal children, ages 5–11 years. Recordings were made from electrodes located at the orbit, the mastoid and at Fz, Cz and Oz. The scoring of reflex blink frequency, the averaging of evoked responses and the development of triggers for averaging involuntary blinks (not flash-associated) were done off-line. The average probability of reflex blinking to moderately intense flash under alert, eyes open conditions was 0.62, with a significant trend to increased blinking during continued testing. In eight subjects who blinked to approximately half the flashes, segregation and separate averaging of blink and blink-free responses demonstrated a substantial difference in the potentials recorded at all locations. Specifically, a positive component at the occiput (scalp to mastoid) occurring approximately 200 msec after flash was enhanced in trials that included reflex blinks. Averages of EEG time-locked to the peak of involuntary blink potentials (no flash) showed penetration of artifact into posterior scalp as well. These findings suggest that many children in this age group exhibit persistent reflex blinking, and that there is a high probability of artifact in the VER therefrom.
Sins of omission : Getting too little medical care may be the greatest threat to patient safety

BACKGROUND: Little is known about the relative incidence of serious errors of omission versus errors of commission.
Pervasive computing in the undergraduate curriculum

How do you prepare students today, to work on the most widely available computing platforms of tomorrow? Programmable cell phones and personal digital assistants (PDAs) have already become more numerous then PCs. With their small size and mobility, these devices present both new opportunities and unique software engineering challenges like small memory models, cross-platform development, state machines, and wireless networking. You will learn how to use the Java Micro Edition (J2ME) to easily develop labs based on arcade and logic games that will motivate and excite your students. In this session we will present the initial results of a NSF CCLI project to develop materials for Handheld and Ubiquitous Computing in the Undergraduate Curriculum.
Effects of NGF-antiserum in sympathetic neurons during early postnatal development.

Abstract Mice at birth and on days 4, 7, and 14 were injected with nerve growth factor antiserum (A-NGF) to determine any changes in the nature of lesions during the early postnatal development of the superior cervical sympathetic ganglion. Correlative light and electron microscopic studies revealed both numerical and morphological changes between the first and second weeks of life. The alterations present in the two younger groups resembled those previously described in the newborn. The three zones were seen in many of the nuclei of affected neurons, resulting from nucleolar segregation. Zones A and B contained RNA and probably represent the pars granulosa and pars fibrosa, respectively, of the nucleolus, while zone C contained DNA, initially forming from the nucleolus-associated chromatin. Lesions were fewer in number and less severe in 7- and 14-day-old mice, but still included similar nucleolar alterations. Zone C differed significantly in structure, however, in that large numbers of vacuoles, many of which contained inclusions of varying form and density, were present throughout its substance. Evidence from 3H-uridine experiments, the similarity of nucleolar alterations to those produced by agents known to block DNA-dependent nucleolar RNA synthesis, and the absence of comparable lesions in the adult strongly suggest that A-NGF produces a block in rRNA synthesis in early neuronal development.
An Examination of the Role of Race and Autonomy Level in the Moral Orientation of Male Greek Students

There are often assumptions made by those working on college campuses that differences exist to varying degrees between the operation, function, and purposes of Greek organizations. Research has concluded a difference in the moral development of Greek students and non-Greek students (Maloney, 1990; Kilgannon & Erwin, 1992; Tripp, 1997; Stanford, 1992; Maisel, 1990). Little attention has been given to factors such that may interact with perceived differences in moral development. This study seeks to examine the role of race and autonomy level as possible intervening variables in moral orientation of Greek and non-Greek members.
Mass spectrometry of self-assembled monolayers: a new tool for molecular surface science.

Most reactions can be performed in solution and on a surface, yet the challenges faced in applying known reactions or in developing entirely new reactions for modifying surfaces remain formidable. The products of many reactions performed in solution can be characterized in minutes, and even products having complex structures can be characterized in hours. When performed on surfaces, even the most basic reactions require a substantial effort—requiring several weeks—to characterize the yields and structures of the products. This contrast stems from the lack of convenient analytical tools that provide rapid information on the structures of molecules attached to a surface. This review describes recent work that has established mass spectrometry as a powerful method for developing and characterizing a broad range of chemical reactions of molecules attached to self-assembled monolayers of alkanethiolates on gold. The SAMDI-TOF mass spectrometry technique will enable a next generation of applications of molecula...
The flexion–rotation test performed actively and passively: a comparison of range of motion in patients with cervicogenic headache

Limitation in cervical spine range of motion (ROM) is one criterion for diagnosis of cervicogenic headaches (CHs). The flexion-rotation test, when performed passively (FRT-P), has been shown to be a useful test in diagnosis of CH. Few investigations have examined the flexion-rotation test when performed actively (FRT-A) by the individual, and no studies have examined the FRT-A in a symptomatic population. The purpose of this study was to compare ROM during the FRT-A and FRT-P in patients with CH and asymptomatic individuals and to compare ROM between sides for these two versions of the test. Twelve patients with CH and 10 asymptomatic participants were included in the study. An eight-camera Motion Analysis system was used to measure head motion relative to the trunk during the FRT-P and the FRT-A. Cervical rotation ROM was measured in a position of full cervical flexion for both tests. No significant difference was observed between right and left sides for cervical rotation ROM during the FRT-P nor the FRT-A when performed by asymptomatic participants. In patients with CH, a significant difference was observed between sides for the FRT-P (P = 0.014); however, the FRT-A failed to reveal bilateral descrepancy in rotation ROM.
Serum IL-6 levels are associated with significant coronary stenosis in cardiovascularly asymptomatic inner-city black adults in the US.

Objectives and design: The objective of this study was to explore whether increased levels of inflammatory cytokines are associated with the risk of clinically silent coronary artery disease.
An evaluation of systems for paper chromatography of C21 steroids.

Abstract A group of moderately polar C 21 steroids (3–5 oxygen functions) has been chromatographed in 9 solvent systems. Using the concept that standard deviation of the mean R F is an index of Chromatographic resolution, and that coefficients of correlation between sets of R F data can be used to quantify the similarities of Chromatographic systems, we have evaluated the resolving properties of the systems when used individually, and also when used in combinations of two, three and four. The discriminating powers of some of the most effective individual systems, and some of the sequences of systems which are most efficient, are shown graphically as chromatography trees. The relationship between the total effective standard deviation of a group of systems which are used in sequence and the probability that a pair of compounds will be separated by more than 0.10 R F is discussed.
Using Group Explorer in teaching abstract algebra

This study explores the use of Group Explorer in an undergraduate mathematics course in abstract algebra. The visual nature of Group Explorer in representing concepts in group theory is an attractive incentive to use this software in the classroom. However, little is known about students� perceptions on this technology in learning concepts in abstract algebra. A total of 26 participants in an undergraduate course studying group theory were surveyed regarding their experiences using Group Explorer. Findings indicate that all participants believed that the software was beneficial to their learning and described their attitudes regarding the software in terms of using the technology and its helpfulness in learning concepts. A multiple regression analysis reveals that representational fluency of concepts with the software correlated significantly with participants� understanding of group concepts yet, participants� attitudes about Group Explorer and technology in general were not significant factors.
There is no special problem with metaphysics

I argue for the claim in the title. Along the way, I also address an independently interesting question: what is metaphysics, anyway? I think that the typical characterizations of metaphysics are inadequate, that a better one is available, and that the better one helps explain why metaphysics is no more problematic than the rest of philosophy.
ERECTILE DYSFUNCTION AFTER A LONG-DISTANCE CYCLING EVENT: ASSOCIATIONS WITH BICYCLE CHARACTERISTICS

ABSTRACT Purpose: We conducted a prospective cohort study to examine the relationship between bicycle characteristics and the occurrence of erectile dysfunction. Materials and Methods: Subjects consisted of 463 cyclists completing a cycling event of at least 320 km who were free of erectile dysfunction before their event. Results: The cumulative incidence of erectile dysfunction after the ride was 4.2% (95% confidence interval [CI] 2.4%–6.8%) and 1.8% (95% CI 0.7%–3.8%) 1 week and 1 month after the event, respectively. Bicycle characteristics associated with an increased risk of erectile dysfunction included a mountain bicycle compared with a road bicycle (risk ratio [RR] 4.1, 95% CI 1.6–12.5), and the relative height of the handlebars parallel with or higher than the saddle compared with the relative handlebar height lower than the saddle (RR 3.0, 95% CI 1.1–9.3). Perineal numbness during the ride was experienced by 31% of the cyclists and was associated with erectile dysfunction (RR 4.4, 95% CI 1.6–12.7). Saddle cutouts were associated with an increased risk of erectile dysfunction among those who experienced numbness (RR 6.0, 95% CI 1.3–27.1), but the association was reversed among those who did not report numbness (RR 0.3, 95% CI 0.0–2.5). Conclusions: If the associations described are causal, then cyclists on a long-distance ride may be able to decrease the risk of erectile dysfunction by riding a road bicycle instead of a mountain bicycle, keeping handlebar height lower than saddle height and using a saddle without a cutout if perineal numbness is experienced.
Lung Cancer in Older Adults

Lung cancer is the leading cause of cancer-related mortality and is responsible for more deaths than breast cancer, prostate cancer, and colon cancer combined. The majority of patients diagnosed with lung cancer are over the age of 65. Despite the prevalence of lung cancer in older adults, they have been notoriously underrepresented in clinical trials designed to help guide clinicians in the management of treatment. In the past 15 years, there have been many improvements that collectively have extended the lives of patients with metastatic lung cancer an average of one year after diagnosis. It is now well-established that age does not diminish the benefit of cancer treatment. However, certain toxicities are more common and may be less tolerated in this age group. It is therefore of paramount importance that clinicians work together to tease out which patients will benefit the most from treatment and to minimize toxicity.
Compliance Strategies and Regulatory Effectiveness of Performance‐Based Regulation of Chemical Accident Risks

This paper investigates the role that performance-based regulations can play in linking a firm's environmental, health, and safety concerns with their corporate strategy. The specific focus is on the performance standards required by the Clean Air Act Amendments (CAAA) which require firms that store or use certain chemicals to develop a Risk Management Plan (RMP) for reducing the likelihood and impact of accidents at their plants. Data from a series of case studies and interviews of executives in chemical firms reveal that proactive companies integrated many of the requirements of the CAAA into their management systems prior to the regulatory requirements. Most of these firms tend to be large ones. Small firms often lack the resources to implement these regulations and hence have tended to have a more difficult time with compliance.
Symmetry of Excitons in Cu 2 O

The anisotropy of the absorption of the $1s$ exciton line in ${\mathrm{Cu}}_{2}$O which is observed by quadrupole radiation shows that this exciton is of type ${{\ensuremath{\Gamma}}_{25}}^{+}$. The details of the anisotropic absorption properties of the Zeeman and Stark effect are predicted and compared with experiment. The anisotropy of the indirect absorption edges allows the symmetry of the phonon involved to be determined. From this symmetry identification it is possible to speculate about the nature of the valence and conduction bands in this substance. The results appear to be in agreement with a spin-orbit split valence band of Cu $3d$ functions and a conduction band of Cu $4s$ functions. Estimates of the ortho-para exciton splitting and Stark strain splitting on this model are of the right order of magnitude but smaller than those observed.
IDENTIFICATION OF HUMAN THYMIC EPITHELIAL CELLS WITH ANTIBODIES TO THYMOSIN α1, IN MYASTHENIA GRAVIS*

Thymosin-alpha 1 (alpha 1) is a potent thymic polypeptide hormone. Using anti-alpha 1 antibodies, we applied indirect immunofluorescence to human normal thymus of different ages and to hyperplastic, thymomatous, and "involuted" thymus of myasthenia gravis (MG) patients. Alpha 1 was localized only in the epithelial cells, lying singly, grouped, in Hassell's corpuscles, and proliferated in thymomas. Whereas normal thymuses and fewer and weakly stained cells, MG thymuses had many strongly positive epithelial cells; this was more evident in thymomas. Germinal centers were unstained. "Involuted" MG thymuses had small islands of brightly stained cells lying among the fatty tissue. In cultured thymuses from three MG patients, epithelial cells but not fibroblasts were brightly stained for alpha 1. Our findings (a) demonstrate the location, and presumably the origin, of alpha 1 to be the thymic epithelial cell; (b) suggest the possibility that excess alpha 1, because of its known effect on T-lymphocyte maturation and transformation of precursors to helper T-cells, may act pathologically to facilitate and perpetuate the dysimmune mechanism in MG; (c) may partially explain the beneficial effect of thymectomy in MG patients of any age; and (d) indicate that epithelial cells may be autonomous for the production of alpha 1 as evidenced by their alpha 1 positivity in culture.
GCLgrid: A three-dimensional geographical curvilinear grid library for computational seismology

We developed a general library for handling a class of objects we call geographical curvilinear grids (GCLgrids). A GCLgrid is a distorted, uniform grid that is georeferenced. The GCLgrid library is implemented in an object oriented system with methods that relate points in the grid to a geographic reference frame. A simple example is a spherical shell divided along latitude, longitude, and depth, but more elaborate shapes can use the same interface. Scalar and vector fields are derived from the base grid through inheritance. Two algorithms are the core of this library. First, we use the Direction Set method to search for a location in space from a starting point. This algorithm converges reasonably fast if the grid is not extremely distorted. Second, we interpolate the grid using methods known from finite element analysis. A Jacobian matrix for an 8-node cube is computed to transform a distorted cube into a unit one. Shape functions for the standard cube are used to compute interpolation coefficients. Once the interpolation coefficients are computed, we can interpolate n-element vectors almost as quickly as scalar data. We show an application of the library to travel time table calculation at regional distances. Our table interpolator was found to be 10 times faster than one based on the tau-p method and is expected to be several orders of magnitude faster than 3D ray-tracing methods. Travel time interpolation errors are reduced significantly by tabulating delay times relative to a homogenous reference model instead of absolute times. This allows much coarser grids to be used at large scales comparing to one using total time.
Oxide Breakdown Model For Very Low Voltages

3 Volt MOS ICs have arrived and the need to understand low voltage Si02 breakdown has taken on new urgency. Previous gate oxide lietime modeling has been based upon empirical 1/E or E models, however they are nct known to account for low voltage breakdown in ultra-thin oxides. We demonstrate a model based upon anode hot hole injection which explains the "thin" oxide breakdown that occurs at oxide voltages as low as 2.5 Volts, while converging to the "thick" oxide (x ox ⩾ 12 nm), high-voltage breakdown of as well.
Architecture of the MEGA detector trigger

Abstract The trigger for the MEGA detector system is based on signals from single, high-energy photons interacting in one of the three MEGA pair spectrometers. The trigger is divided into a fast and a slow stage. The first stage produces a fast output if a specific pattern of detector hits is observed in the scintillators and high-speed wire chambers of a pair spectrometer. The second, slow-stage interrogates drift chamber hit patterns and provides a veto when the pattern fails a minimal requirement for reconstruction of the hits into a pair of circular orbits. The trigger interacts with the photon detector electronics by gating limited sections of the detector during the read-out of an event. This paper describes the two stage trigger system, the photon detector electronics, and the implementation of the trigger outputs to strobe the data acquisition system. The performance of the trigger is compared to Monte Carlo simulations of the photon detector response.
Ras proteins are essential and selective for the action of insulin-like growth factor 1 late in the G1 phase of the cell cycle in BALB/c murine fibroblasts.

Abstract BALB/c 3T3 cells (A31 cells) require the sequential action of growth factors in order to proliferate from a quiescent growth state. Insulin-like growth factor I (IGF-I) is needed late in the G1 phase of the cell cycle, a time at which expression of the c-Ha-ras protooncogene is near maximal. An anti-ras antibody, introduced by microinjection, specifically blocked the ability of IGF-I to stimulate initiation of DNA synthesis. The antibody was specific for IGF-I; it failed to block serum, platelet-derived growth factor, or epidermal growth factor from inducing c-fos mRNA. By contrast, an anti-G alpha-subunit antibody had no effect on IGF-I-stimulated DNA synthesis but inhibited the induction of c-fos mRNA by platelet-derived growth factor or epidermal growth factor. BPA31 cells are tumorigenic A31-derived cells that progress through G1 in the absence of IGF-I. BPA31 cells produced an autocrine IGF-I that was responsible for the loss of late G1 control; the anti-ras antibody arrested the growth of these cells in late G1. The results suggest that ras proteins are essential for an IGF-I-sensitive, G1 control point.
A Distribution-Free Comparison of Multiple Tumor Incidence in the Presence of Unrelated Censoring

SYNOPTIC ABSTRACTA method of analysis is proposed for tumorigenicity experiments in which an animal may develop more than one tumor of a given type, e.g. mammary tumors. Present methodology, both parametric and nonparametric, generally ignores all but the first of these tumors. One exception is the paper by Gail, Santner and Brown (1980), which makes somewhat different and more restrictive assumptions than are made here. It is shown in the present paper how the entire observed tumor incidence may be incorporated into the analysis despite the presence of unrelated censoring (in this case, mortality). The distribution-free test statistic for comparing tumor incidence across treatments is shown to be asymptotically distributed as chi-square, conditional on the pattern of censoring.
Activation of Hydrogen and Related Small Molecules by the Unsaturated Cluster Complex PtOs3(CO)7(PBut3)(μ-PBut2)(μ4-CHCMeCH)

Reactions of the unsaturated mixed metal cluster complex PtOs3(CO)7(PBut3)(μ-PBut2)(μ4-CHCMeCH), 1, with hydrogen, HGePh3, and PhC2H have been investigated. Compound 1 reacts reversibly with hydrog...
New aquatic and water-borne hyphomycetes from the Southern Appalachian Mountains of the United States

Four new hyphomycete taxa from North Carolina and Tennessee are described and illustrated. One previously described taxon is neotypified and one transfer is made.
Six sigma education: a critical role for academia

Applications of the six sigma methodology to quality improvement abound in various sectors. A tremendous interest and increase in such practices have been witnessed in manufacturing and non-manufacturing areas. Sound application of the six sigma methodology requires a thorough grounding in the statistical concepts and foundations, the inherent assumptions made in using the techniques, and their limitations. Academia, therefore, has an important role to play in meeting these objectives.
The current state of paclitaxel and radiation in the combined-modality therapy of non-small cell lung cancer.

Abstract The results of randomized trials have prompted an evolution in the treatment approach to inoperable locally advanced non-small cell lung cancer, from radio-therapy alone to sequential chemoradiotherapy and now to concurrent chemoradiotherapy. The improvement in outcome seen with a concurrent chemoradio-therapy approach may be because of spatial cooperation, enhanced radiosensitization, and/or enhanced cytotoxicity. The taxanes, specifically paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ), delivered in combination with radiation have been extensively examined in both preclinical and clinical studies. Several mechanisms have been suggested to explain the enhanced tumor cell kill seen with paclitaxel and radiation, and phase II studies have examined this combination in the setting of inoperable stage III non-small cell lung cancer. This review will explore some of the studies with this treatment approach in locally advanced disease. We also will briefly discuss some of the ongoing trials that are attempting to refine the delivery of concurrent thoracic radiation and paclitaxel-based chemotherapy.
The Psychology of Dilemmas and the Philosophy of Morality

We review several instances where cognitive research has identified distinct psychological mechanisms for moral judgment that yield conflicting answers to moral dilemmas. In each of these cases, the conflict between psychological mechanisms is paralleled by prominent philosophical debates between different moral theories. A parsimonious account of this data is that key claims supporting different moral theories ultimately derive from the psychological mechanisms that give rise to moral judgments. If this view is correct, it has some important implications for the practice of philosophy. We suggest several ways that moral philosophy and practical reasoning can proceed in the face of discordant theories grounded in diverse psychological mechanisms.
Self-assembly: from crystals to cells

Self-assembly (SA) is the process in which a system's components—be it molecules, polymers, colloids, or macroscopic particles—organize into ordered and/or functional structures without human intervention. The main challenge in SA research is the ability to “program” the properties of the individual pieces such that they organize into a desired structure. Although a general strategy for doing so is still elusive, heuristic rules can be formulated that guide design of SA under various conditions and thermodynamic constraints. This Review examines SA in both the equilibrium and non-equilibrium/dynamic systems and discusses different SA modalities: energy driven, entropy-driven, templated, and field-directed. Non-equilibrium SA is discussed as a route to reconfigurable (“adaptive”) materials, and its connection to biological systems is emphasized.
Light adaptation through phosphoinositide-regulated translocation of Drosophila visual arrestin.

Abstract Photoreceptor cells adapt to bright or continuous light, although the molecular mechanisms underlying this phenomenon are incompletely understood. Here, we report a mechanism of light adaptation in Drosophila , which is regulated by phosphoinositides (PIs). We found that light-dependent translocation of arrestin was defective in mutants that disrupt PI metabolism or trafficking. Arrestin bound to PIP 3 in vitro, and mutation of this site delayed arrestin shuttling and resulted in defects in the termination of the light response, which is normally accelerated by prior exposure to light. Disruption of the arrestin/PI interaction also suppressed retinal degeneration caused by excessive endocytosis of rhodopsin/arrestin complexes. These findings indicate that light-dependent trafficking of arrestin is regulated by direct interaction with PIs and is required for light adaptation. Since phospholipase C activity is required for activation of Drosophila phototransduction, these data point to a dual role of PIs in phototransduction.
Immunotherapeutic advances in the treatment of gram-negative bacterial sepsis.

Gram-negative bacterial sepsis with the frequent sequelae of shock, multi-system organ failure, and death represents one of the most severe infections that can occur in the surgical patient. Fatality in most series has paralleled the presence and severity of underlying host disease processes, polymicrobial bacteremia, shock, and lack of early appropriate antimicrobial therapy. Even patients with no underlying disease state have a significant mortality (10–20%). Therapy of gram-negative bacterial sepsis and shock at present consists of antimicrobial agents, hemodynamic monitoring, aggressive fluid resuscitation, and metabolic support. The use of these treatment modalities in concert has reduced, but not eliminated, the severe consequences that may ensue. Administration of antibody directed against the comon core lipopolysaccharide antigen of gramnegative microorganisms to patients with gram-negative sepsis represents a means by which the morbidity and mortality of this disease process may be further reduced. This is supported by a large body of experimental evidence, as well as several preliminary clinical studies. It is necessary to determine how the clinical efficacy of such antibody preparations can be maximized. This will entail rigorously controlled studies in which the timing of antibody administration and dose utilized can be correlated with clinical efficacy. Should such antibody preparations continue to prove efficacious as an additive form of therapy, it may be possible to identify high-risk groups of patients who would benefit from antibody prophylaxis.
Block-iterative finite element computations for incompressible flow problems

A block-iterative finite element procedure is presented for two-dimensional fluid dynamics computations on multiply-connected domains based on the vorticity - stream function formulation of the incompressible Navier-Stokes equations. The difficulty associated with the convection term in the vorticity transport equation is addressed by using a streamline-upwind/Petrov-Galerkin scheme.Element-by-element preconditioned iteration techniques with high degree of vectorization and high computational speed are employed to solve the linear equation system for each block. Performance evaluations show the potential of these techniques to be used for large-scale computations.
Theoretical studies in molecular recognition: Rebek's cleft†

Molecular recognition in Rebek's cleft was studied with the MM2 force field. A new computational protocol was used to determine the free energies of substrate binding to this topologically unique model receptor. The energies and structural features of substrate-receptor complexes reveal that molecular recognition involves ammonium ion binding to the interior of the cleft and aromatic π-stacking on the exterior of the cleft.
Water desalination: Graphene cleans up water

Graphene promises water desalination at throughputs much higher than state-of-the-art membranes.
Functional magnetic resonance imaging in studies of the neurobiology of suicidal behavior in adolescents with alcohol use disorders.

Functional MRI of the brain is a technique that localizes regions of activity in the brain following task activation. It is useful to neuroscientists interested in interrogating the localization of certain brain functions. Alcohol misuse is a complex, multidimensional disorder involving problematic ethanol ingestion and reflected in behavior. Genetic factors play an important role in the etiopathogenesis of alcohol abuse in adolescents. Alcohol use disorders tend to run in families with 40-60% of the variance of risk explained by genetic influences. Numerous well-designed twin, adoption, and family studies have demonstrated that genetic factors are important in determining vulnerability to alcohol use disorders. There is a tendency for people who misuse alcohol to marry individuals who also abuse alcohol (assortative mating). Thus, many adolescent alcohol misusers are from families with a high proportion of alcohol abuse or dependence. It has been shown that alcohol abusing adolescents have a number of cognitive deficits. Neuropsychological studies of adolescents with alcohol use disorders have reported decrements in language skills, problem solving, verbal and non-verbal retention, working memory, and visuospatial performance. Some cognitive deficits may be present before an adolescent starts drinking and contribute to the development of alcohol use disorders. Data suggest that neuropsychological dysfunction may play a role in determining risk for suicidal acts. Therefore, studies of cognitive impairments and the neural substrate of these impairments in alcohol abusing adolescents may help develop methods of identifying teenagers who are at increased risk for suicide and contribute to our knowledge of the neurobiology of suicidal behavior and may lead to the development of new treatment methods. Language: en
Three steps forward, two steps back in automotive supplier relations

Abstract This article analyzes data from a survey of over 600 automotive suppliers in the United States conducted for MIT's International Motor Vehicle Program. The article shows that closely-linked, ‘voice’ relationships have performance advantages for both automakers and their suppliers. While progress is being made, only 21 % of survey respondents currently have such high-performance relationships with their customers.
Permeation of oxygen, argon and nitrogen through polymer membranes

Abstract In order to screen polymer materials suitable for the separation of O 2 /Ar mixtures, gas permeability coefficients of O 2 , Ar and N 2 through a total of 19 polymers were measured at 25°C and atmospheric pressure. Diffusion coefficients and solubility coefficients were calculated from time-lag data. The gas permeabilities and diffusivities in all polymers tested are in the order of O 2 >Ar>N 2 , while the gas solubilities are in the order of Ar>O 2 >N 2 . Higher permselectivities are observed in glassy polymers than in rubbery polymers. Permeability ratios, which denote the ideal separation factors, for O 2 /Ar in glassy polymers are strongly affected by the contribution of the diffusivity ratios. The absolute diffusivities and the diffusivity ratios are correlated rather well using the free volume theory of polymers which employs the group contribution method based on the chemical structure of polymers. Slight deviations from the expected values are discussed by introducing a factor of polymer chain fluctuation speed. Poly (2,6-dimethyl-1,4-phenylene oxide) and tetramethyl bisphenol-A polycarbonate exhibit a relatively high permeability of O 2 and a high permeability ratio of O 2 /Ar. Temperature and pressure dependencies of gas permeabilities are examined with these two polymers.
No direct path from genes to phenotype

Biometrical Genetics: The Study of Continuous Variation, 3rd Edn. By Kenneth Mather and John L. Jinks. Pp.396. ISBN 0-412-22890-4. (Chapman & Hall: 1982.) £22.50, $49.95.
Niche and fitness differences relate the maintenance of diversity to ecosystem function

The frequently observed positive correlation between species diversity and community biomass is thought to depend on both the degree of resource partitioning and on competitive dominance between consumers, two properties that are also central to theories of species coexistence. To make an explicit link between theory on the causes and consequences of biodiversity, we define in a precise way two kinds of differences among species: niche differences, which promote coexistence, and relative fitness differences, which promote competitive exclusion. In a classic model of exploitative competition, promoting coexistence by increasing niche differences typically, although not universally, increases the "relative yield total", a measure of diversity's effect on the biomass of competitors. In addition, however, we show that promoting coexistence by decreasing relative fitness differences also increases the relative yield total. Thus, two fundamentally different mechanisms of species coexistence both strengthen the influence of diversity on biomass yield. The model and our analysis also yield insight on the interpretation of experimental diversity manipulations. Specifically, the frequently reported "complementarity effect" appears to give a largely skewed estimate of resource partitioning. Likewise, the "selection effect" does not seem to isolate biomass changes attributable to species composition rather than species richness, as is commonly presumed. We conclude that past inferences about the cause of observed diversity-function relationships may be unreliable, and that new empirical estimates of niche and relative fitness differences are necessary to uncover the ecological mechanisms responsible for diversity-function relationships.
Size independent implementation of matrix operations on TASA-a two-dimensional array matrix architecture

A two-dimensional-array systolic architecture (TASA) is a general-purpose parallel computer for solving a wide class of computationally intensive problems. The application of TASA to implement the Faddeev algorithm for classical matrix algebra operations has been previously shown. It is shown here that this architecture is problem size independent for the Faddeev algorithm. >
Andean Silver and the Rise of the Western World

This essay analyzes the contribution of Andean silver to the mercantile accumulation in the European core countries by tracing the flow of silver from the Andes to Asia. American Silver became the empowering currency that enabled the dynamic West European countries to dominate overseas trade. I argue that the influx of American silver into Europe over a period of three hundred years not only constituted a remarkable source of wealth, but also had systemic effects on the rise of the Western World influencing the global balance of power. I present a schematic model of the mercantile accumulation in the European hegemonic centers that explains how the external stimulus was amplified through positive feedback mechanisms.
Method of moments evaluation of the two-dimensional quasi-crystalline approximation

In remote sensing, the propagation of electromagnetic fields through random media is often of concern. We may wish to characterize the effects of clouds or water droplets along the line of sight between an airplane and a radar installation, or we may be interested in using radar to probe the random medium itself, such as in determining snow depth and particle size. In all of these problems it is necessary to predict the propagation constant in the "random" medium. The purpose of this paper is to characterize the accuracy of the quasi-crystalline approximation and other associated methods of determining the effective permittivity for two-dimensional (2-D) random media. A numerical method based on the method of moments is used as a gauge for comparison with the theoretical methods. After deriving the 2-D quasi-crystalline approximation and presenting the numerical method, the behavior of the effective permittivity is analyzed for a range of particle sizes, volume fractions and dielectric losses. From this analysis, regions of validity for the theoretical methods are determined. An investigation is also given which explores the effect of particle arrangement methods on the pair distribution function which, in turn, is shown to have a significant effect on the imaginary component of the effective permittivity.
Correlates of Sexual Behavior in Young Children

SUMMARY Sexual behavior in children ages 2–12 is related to a variety of environmental, child-specific, and reporter-related variables. This paper reviews correlational research that has examined the relationship of sexual behavior to the variables of sexual abuse, domestic violence, physical abuse, family sexuality, age and gender of the child, child behavior problems, and reporter characteristics. Sexual behavior is directly related to environmental variables that cause dysregulated behavior in children. It is also associated with child behavior problems and varies with age and gender. There are a number of reporter-specific variables, including education level, abuse history, and openness to sexuality, that are also related to the level of reported sexual behavior. The article concludes with a reminder that correlation does not mean causation.
An experimental evaluation of spam filter performance and robustness against attack

In this paper, we show experimentally that learning filters are able to classify large corpora of spam and legitimate email messages with a high degree of accuracy. The corpora in our experiments contain about half a million spam messages and a similar number of legitimate messages, making them two orders of magnitude larger than the corpora used in current research. The use of such large corpora represents a collaborative approach to spam filtering because the corpora combine spam and legitimate messages from many different sources. First, we show that this collaborative approach creates very accurate spam filters. Then, we introduce an effective attack against these filters which successfully degrades their ability to classify spam. Finally, we present an effective solution to the above attack which involves retraining the filters to accurately identify the attack messages
Transcriptional profiling of CD4 T-lymphocytes reveals abnormal gene expression in young prediabetic NOD mice

Background CD4 T-lymphocytes play a prominent role in Type 1 DM. The NOD mouse is a model for this autoimmune disease. The earliest histological signs of autoimmunity in female NOD mice occur at approximately 5 weeks of age. We hypothesized that this process may be preceded by molecular events in the CD4 T-lymphocytes. To test this hypothesis, we analyzed the transcriptomes of CD4 Tlymphocytes of young "prepathologic" NOD mice.
Detection of Lagrangian coherent structures in three-dimensional turbulence

We use direct Lyapunov exponents (DLE) to identify Lagrangian coherent structures in two different three-dimensional flows, including a single isolated hairpin vortex, and a fully developed turbulent flow. These results are compared with commonly used Eulerian criteria for coherent vortices. We find that despite additional computational cost, the DLE method has several advantages over Eulerian methods, including greater detail and the ability to define structure boundaries without relying on a preselected threshold. As a further advantage, the DLE method requires no velocity derivatives, which are often too noisy to be useful in the study of a turbulent flow. We study the evolution of a single hairpin vortex into a packet of similar structures, and show that the birth of a secondary vortex corresponds to a loss of hyperbolicity of the Lagrangian coherent structures.
Identification of Structural and Spatial Features that Influence Storm-Related Dune Erosion along a Barrier-Island Ecosystem in the Gulf of Mexico

Abstract Observations of hurricane impacts on coastal communities and predicted increases in tropical storm activity have spurred an interest in protection and restoration of coastal dunes. Dunes are valued for their role in the protection of infrastructure and aesthetic beauty. Past research on dune erosion has focused primarily on laboratory research or mathematical models. We directly assessed impacts of Hurricanes Ivan (2004) and Dennis (2005) on coastal dunes along Santa Rosa Island, a barrier island in the Gulf of Mexico. We recorded dune area for foredunes and secondary dunes, examined the spatial context of each dune, and recorded structural features of each dune before and after each hurricane. Both hurricanes severely impacted foredunes, and removal of foredune protection by Ivan led to severe impacts on secondary dunes from Dennis. Structural features of the dune, such as height and width, influenced resistance against storm-related erosion, but spatial context, such as location with respect to...
Fifty-percent probability of identification (N50) comparison for targets in the visible and infrared spectral bands

We describe a comparison of target identification performance between targets in the IR and visible bands. Increasing levels of Gaussian blur are applied to 12 varying viewpoint aspects of 12 targets in both the IR and visible spectra. Results are analyzed as a function of blur level and target size to give identification probability as a function of resolvable cycles on target. Probability curves for the IR and visible results are compared and the 50% probabilities of identification ( N 50 ) are estimated for both cases. The results show that there is a significant difference in the target acquisition characteristics in the visible and IR wavebands.