cssi/SciSciGPT-SciSciNet huggingface dataset:
Reaffirmation That Metabolism of Polyamines by Bovine Plasma Amine Oxidase Occurs Strictly at the Primary Amino Termini

Abstract Oxidation of the biologically important polyamines spermine and spermidine by plasma amine oxidase (PAO) was specified many years ago to occur at the terminal primary rather than internal secondary amine positions. However, the finding of sequential enzymatic conversion of spermine to spermidine and then to putrescine (1,4-butanediamine) is superficially suggestive of metabolism at the secondary amine positions, and a recent publication (Houen, G., Bock, K., and Jensen, A. L. (1994) Acta Chem. Scand. 48, 52–60) claimed that the original interpretation of preferential “terminal” deamination does not stand up to scrutiny with modern methods of analysis. We herein demonstrate that the findings cited in support of secondary amine deamination can arise artifactually from spontaneous elimination/addition reactions following initial metabolism at the terminal positions of 3-(aminopropyl)amines. We further find no evidence for the ability of PAO to metabolize the secondary amine position in homospermidine, which is devoid of such complicating side reactions. Our results support the original claimed specificity of PAO for the primary amino termini of polyamines, all of which are consistent with the general finding that the quinone-dependent copper amine oxidases specifically metabolize primary amines.
Oxidative Stress and Cancer: A β-Catenin Convergence

The multifunctional protein-catenin is a critical component of the widely conserved Wnt signaling pathway. Misregulation of this important protein is a causative factor in some human cancers. A Perspective by [Bowerman][1] discusses new findings that-catenin can act through the FOXO family of transcription factors to promote survival of mammalian cells under stressful conditions and increase the life span of C. elegans . These intriguing results have interesting implications for tumorigenesis, cancer therapy, and aging. [1]: http://www.sciencemag.org/cgi/content/full/308/5725/1119
Fluvial disturbance patches and cottonwood recruitment along the Upper Missouri River, Montana

The disturbance patches most suitable for seedling establishment of pioneer riparian trees are also subject to future disturbances that produce high seedling mortality. We are monitoring plains cottonwood seedling establishment and mortality along the Wild and Scenic reach of the Missouri River upstream of Fort Peck Reservoir, Montana at four sites subject to livestock grazing and four paired, ungrazed exclosures. New seedlings at these sites were largely restricted to surfaces inundated by spring and summer flows. Winter ice drives and livestock grazing are important mortality factors along the study reach. Livestock grazing reduced seedling densities, although the position of these seeclings in normal flow years means it is unlikely that they will survive future disturbance. Average values of the maximum density parameter of a Gaussian curve of seedling distribution along a hydraulic gradient of inundating discharge were 30 and 114 seedlings/m2 on ungrazed sites in 1996 and 1997, compared to 19 and 18 seedlings/m2 for grazed sites. Water-surface elevations produced, by ice drives and damming in the severe winter of 1995–1996 corresponded to inundating discharges of 1,670 to 4,580 m3/s. No existing trees at the study sites occurred at inundating discharges below 1,625 m3/s. Seedlings established as a result of maximum summer flows of 827 and 1,201 m3/s in 1996 and 1997 were all below the elevation of the 10-year return flow of 1,495 m3/s. Recruitment of plains cottonwood trees along this reach of the Missouri River is strongly dependent on infrequent high flows that position moist, bare disturbed patches high enough for seedlings to establish and survive subsequent flooding and ice scour, in contrast to other reaches and streams where hydrogeomophic processes of channel meandering and narrowing produce different patterns of disturbance patches.
Cadmium levels in a North Carolina cohort: Identifying risk factors for elevated levels during pregnancy.

Cadmium levels in a North Carolina cohort: Identifying risk factors for elevated levels during pregnancy
Band-limited random waveforms in compressive radar imaging

Compressive sensing makes it possible to recover sparse target scenes from under-sampled measurements when uncorrelated random-noise waveforms are used as probing signals. The mathematical theory behind this assertion is based on the fact that Toeplitz and circulant random matrices generated from independent identically distributed (i.i.d) Gaussian random sequences satisfy the restricted isometry property. In real systems, waveforms have smooth, non-ideal autocorrelation functions, thereby degrading the performance of compressive sensing algorithms. In this paper, we extend the existing theory to incorporate such non-idealities into the analysis of compressive recovery. The presence of extended scatterers also causes distortions due to the correlation between different cells of the target scene. Extended targets make the target scene more dense, causing random transmit waveforms to be sub-optimal for recovery. We propose to incorporate extended targets by considering them to be sparsely representable in redundant dictionaries. We demonstrate that a low complexity algorithm to optimize the transmit waveform leads to improved performance.
On (ab)normality: Einstein's fusiform gyrus.

Recently, Hines (2014) wrote an evocative paper challenging findings from both histological and morphological studies of Einstein’s brain. In this discussion paper, I extend Hines’ theoretical point and further discuss how best to determine ‘abnormal’ morphology. To do so, I assess the sulcal patterning of Einstein’s fusiform gyrus (FG) for the first time. The sulcal patterning of the FG was unconsidered in prior studies because the morphological features of the mid-fusiform sulcus have only been clarified recently. On the one hand, the sulcal patterning of Einstein’s FG is abnormal relative to averages of ‘normal’ brains generated from two independent datasets (N = 39 and N = 15, respectively). On the other hand, within the 108 hemispheres used to make these average brains, it is not impossible to find FG sulcal patterns that resemble those of Einstein. Thus, concluding whether a morphological pattern is normal or abnormal heavily depends on the chosen analysis method (e.g. group average vs. individual). Such findings question the functional meaning of morphological ‘abnormalities’ when determined by comparing an individual to an average brain or average frequency characteristics. These observations are not only important for analyzing a rare brain such as that of Einstein, but also for comparing macroanatomical features between typical and atypical populations.
Image understanding algorithms for segmentation evaluation and region-of-interest identification using Bayesian networks

A two-fold image understanding algorithm based on Bayesian networks is introduced. The methodology has modules for image segmentation evaluation and region of interest (ROI) identification. The former uses a set of segmentation maps (SMs) of a target image to identify the optimal one. These SMs could be generated from the same segmentation algorithm at different thresholds or from different segmentation techniques. Global and regional low-level image features are extracted from the optimal SM and used along with the original image to identify the ROI. The proposed algorithm was tested on a set of 4000 color images that are publicly available and compared favorably to the state-of-the-art techniques. Applications of the proposed framework include image compression, image summarization, mobile phone imagery, digital photo cropping, and image thumb-nailing.
Characterization of cellular accumulation and toxicity of illudin S in sensitive and nonsensitive tumor cells

Illudins are novel low molecular weight natural products cytotoxic to human tumor cells in vitro. Illudin-derived analogs are effective against experimental human cancers nonresponsive to conventional anticancer agents. It is not known why some illudin analogs are more efficacious in vitro and in vivo than other analogs. Therefore, the in vitro cytotoxicity of the parent compound illudin S towards tumor cells was characterized using radiolabeled drug. Two cell lines sensitive at nanomolar concentrations using only a 15-min exposure period displayed a saturable, energydependent accumulation of illudins with relatively low Km and high Vmax values. A nonsensitive cell line, requiring millimolar concentrations to achieve in vitro toxicity, showed minimal illudin uptake with higher Km and lower Vmax values. No release of radioactivity could be demonstrated from tumor cells, indicating that there was no efflux of illudin S (or metabolites) from these cells. The number of intracellular illudin S molecules required to kill 50% of cells of different tumor cell lines varied from 78 000 to 1 114 000 molecules per cell and was correlated with the 2-h IC50 value determined using a colony-forming assay. Illudin S was cytotoxic to a variety of multidrug-resistant tumor cell lines regardless of whether resistance was mediated by gp170/mdrl, gp180/MRP, GSHTR-pi, topoisomerase I,topoisomerase II, increased DNA repair capacity, or alterations in intracellular thiol content. Information obtained in this study could be used to design clinical phase I trials and to develop analogs with improved therapeutic indexes.
(Ca-Mg)ATPase activity of human erythrocyte membranes: influence of incubation buffer.

Activity of the (Ca−Mg) ATPase of human red blood cell membranes is highly dependent on the specific buffer used in the ATPase assay. Activity is highest in histidine and/or imidazole buffers and is lowest in HEPES buffer.
Changes in pressing for intracranial stimulation (ICS) after prolonged ICS

Rats, fixed with two chronically indwelling electrodes, pressed daily for fixed intensities of ICS while press rates were tabulated. As daily testing for press rates continued, there were sessions in which 20-sec trains of low-intensity (20 μA or less of 60-Hz sine waves) were imposed at some electrode sites. These trains of ICS led to reduced pressing rates for the fixed ICS, but 20 sec of intermittent ICS (.25 sec on,.25 sec off) or zero ICS did not. It was concluded that 20 sec ICS of low intensity, an ICS frequently used in studies of motivation, reduced the capacity of ICS to sustain pressing, probably by disrupting the tissue of ICS.
Melatonin effects on sleep, mood, and cognition in elderly with mild cognitive impairment

The effects of immediate-release melatonin on circadian rest-activity profiles, cognition, and mood were investigated in ten elderly individuals with self-reported sleep-wake disturbances. Melatonin (6 mg), administered 2 hr before habitual bedtime, enhanced the rest-activity rhythm and improved sleep quality as observed in a reduction in sleep onset latency and in the number of transitions from sleep to wakefulness. However, total sleep time was not significantly increased nor was wake within sleep significantly reduced. The ability to remember previously learned items improved along with a significant reduction in depressed moods. No side effects or contraindications were reported by any of our participants during the 10 day trials. These data suggest that melatonin can safely improve some aspects of sleep, memory, and mood in the elderly in short-term use.
A casting based process to fabricate 3D alginate scaffolds and to investigate the influence of heat transfer on pore architecture during fabrication

Abstract The fabrication of 3-dimensional (3D) tissue scaffolds is a competitive approach to engineered tissues. An ideal tissue scaffold must be highly porous, biocompatible, biodegradable, easily processed and cost-effective, and have adequate mechanical properties. A casting based process has been developed in this study to fabricate 3D alginate tissue scaffolds. The alginate/calcium gluconate hydrogel was quenched in a glass mold and freeze dried to form a highly porous tissue scaffold whose tiny pores retain the shape of the ice crystals during quenching. Knowing that the water in the alginate hydrogel would form ice crystals if frozen and that different cooling conditions may dramatically influence the pore architecture, the speed and direction of the heat transfer in freeze drying hydrogel were examined with regard to pore size and orientation. The pore architecture at the different locations of the fabricated scaffolds was characterized using scanning electron microscopy. The fabricated scaffolds consist of pores that are highly interconnected, with a diameter about 200 µm (average diameter of a capillary) to permit blood vessel penetration. It also has been found that the pore size, orientation, and uniformity are significantly affected by the condition of heat transfer during freeze drying. Tailoring the pore architecture of the scaffolds is feasible by controlling heat transfer. This study provides an insight on pore architecture formation and control by altered process parameters.
Rapamune (Sirolimus, Rapamycin): An Overview and Mechanism of Action

Rapamycin (Sirolimus, Rapamune), a potent immunosuppressive agent, has been demonstrated to have remarkable activity in inhibiting allograft rejection in animal models of transplantation. It is currently in phase II clinical trials. Rapamycin belongs to the class of macrocyclic immunosuppressive drugs that are bioactive only when bound to immunophilins. Cyclosporin A and FK506, two other members of this class, selectively block the transcriptional activation of several cytokine genes, thereby inhibiting cytokine production. Although rapamycin and its structural analog FK506 bind to the same immunophilin (FKBP), rapamycin acts at a later stage in T-cell cycle progression by blocking cytokine-mediated signal transduction pathways. This inhibition is the consequence of modulation of activity of a target protein by the rapamycin: FKBP complex [sirolimus effector protein (SEP)]. Although the identification of SEP has recently been reported, its function in cell-cycle progression is not known. The biochemical events that rapamycin has been shown to inhibit are (a) activation of p70S6 kinase, (b) activation of cdk2/cyclin E complex, (c) phosphorylation of retinoblastoma protein, and (d) suppression of cdc2 and cyclin A transcription.
COPOLYMER-MEDIATED FABRICATION OF VERSATILE ELECTRO-ACTIVE AND INFLAMMATION ATTENUATING SUBSTRATES FOR BIOLOGICAL INTERROGATION

Serving as platforms for both cellular interrogation as well as biomembrane mimicry, biotic–abiotic functionalized materials, such as block copolymeric membranes, offer the opportunity for tailored biology, where specific embedded functionalities can be rapidly engineered, on demand, without the need for genetic processing. These versatile materials enable rapid, thin film deposition of a plethora of biologically-relevant materials at the air–water interface given their amphiphilic properties, meaning that they possess alternating hydrophilic and hydrophobic components. This property confers to these materials the ability to be transferred to a wide range of substrates and materials, further enhancing their interfacial versatility. In addition, their biologically-inert, and tunable, thickness-dependent insulating properties serve as ideal bio-active substrates while maintaining the functionality of the integrated molecule (e.g., protein, effector molecule, etc.). Here, we report the application of a polyethyleneoxide–polymethylmethacrylate (PEO–PMMA) diblock and polymethyloxazoline–polydimethylsiloxane–polymethyloxazoline (PMOXA–PDMS–PMOXA) triblock copolymers as molecular anchors for tethering a broad spectrum of materials. These include carbon nanotubes for the fabrication of bioelectrodes to measure cytochrome c-mediated oxidation-reduction, as well as the anti-inflammatory molecule, dexamethasone, for the suppression of lipopolysaccharide (LPS)-induced inflammation in murine macrophages. As such, this work demonstrates the versatility, and broad applicability and impact of this platform approach towards the fabrication of multifunctional arrays of biologically-active surfaces for experimentation ranging from bio-electroactivity to studies of cellular immunity.
Cellulitis after axillary lymph node dissection for carcinoma of the breast

We present a series of patients who developed cellulitis following axillary lymph node dissection for carcinoma of the breast. Bacterial cultures were not helpful in making a diagnosis for the majority of the cases. The clinical scenario of upper extremity cellulitis after axillary dissection mimics the presentation of cellulitis in the lower extremity. Until diagnostic methods or treatment advances can eliminate the indications for axillary lymphadenectomy, many women treated for breast cancer will be at long-term risk for the development of cellulitis due to localized immune impairment. Patient and physician awareness of this syndrome is the best available tool to prevent secondary exacerbation of lymphedema. Prompt treatment with appropriate antibiotics appears universally successful. Antistreptococcal antibiotics should not be withheld pending results of blood or tissue cultures, since in only a few cases will a pathogen be isolated. Although there are no studies confirming the concept, it is likely that appropriate treatment for lymphedema may reduce the risk of infection.
Experimental Human Infection with Norwalk Virus Elicits a Surrogate Neutralizing Antibody Response with Cross-Genogroup Activity

The human noroviruses (NoVs) are genetically diverse, rapidly evolving RNA viruses and are the major cause of epidemic gastroenteritis of humans. Serum antibodies that block the interaction of NoVs and NoV viruslike particles (VLPs) with host attachment factors are considered surrogate neutralizing antibodies in the absence of cell culture and small-animal replication models for the human NoVs. A serological assay for NoV-blocking antibodies was used to assess the breadth of the heterotypic antibody response in the context of an experimental challenge study with a human NoV. Heterotypic histo-blood group antigen (HBGA)-blocking activity against GI.4, GI.7, and GII.4 NoVs increased significantly in the serum of individuals (n = 18) infected with Norwalk virus (GI.1). Although the fold increases and peak titers of heterotypic antibody were more modest than titers of antibody reactive with the challenge antigen, Norwalk virus infection elicited a serological rise even against the novel Sydney variant of GII.4 NoVs. These observations indicate that the development of a broadly cross-protective NoV vaccine containing a limited number of genotypes may be possible.
A balanced tree storage and retrieval algorithm

A storage and retrieval scheme which places items to be stored at the nodes of a binary tree is discussed. The tree is always balanced in a certain sense thus insuring that no excessively long search paths can exist. In addition to presenting the storage and retrieval algorithms, the deletion problem is also solved. The programming approaches involved yield a non-trivial case study of list-processing techniques. Finally, a cost analysis is given.
Abductive Thinking and Sensemaking: The Drivers of Design Synthesis

Overview: Making Sense of Chaos Designers, as well as those who research and describe the process of design, continually describe design as a way of organizing complexity or finding clarity in chaos. Jeff Veen, founder of Adaptive Path, has noted that “Good designers can create normalcy out of chaos.”1 Jim Wicks, Vice President and Director of Motorola’s Consumer Experience Design group explains that “design is always about synthesis—synthesis of market needs, technology trends, and business needs.”2 During synthesis, designers attempt “to organize, manipulate, prune, and filter gathered data into a cohesive structure for information building.”3 Synthesis reveals a cohesion and sense of continuity; synthesis indicates a push towards organization, reduction, and clarity. Yet despite the acknowledged importance of this phase of the design process, there continues to appear something magical about synthesis when encountered in professional practice: because synthesis is frequently performed privately (“in the head” or “on scratch paper”), the outcome is all that is observed, and this only after the designer has explicitly begun the form-making portion of the design process. While other aspects of the design process are visible to non-designers (such as drawing, which can be observed and generally grasped even by a naive and detached audience), synthesis is often a more insular activity, one that is less obviously understood, or even completely hidden from view. Designers may follow a user-centered discovery process to immerse themselves in a particular subject or discipline, and then go “incubate” that material. After a period of reflection, they will produce a tangible artifact as a visual representation of the reflection. When synthesis is conducted as a private exercise, there is no visible connection between the input and the output; often, even the designers themselves are unable to articulate exactly why their design insights are valuable. Clients are left to trust the designer, and more often than not, the clients simply reject the insight as being “blue sky” or simply too risky. For example, a designer developing a new digital device might study the use of digital devices used in the workplace. Typically, a designer will observe four or five users as those individuals conduct their work. The designer will ask questions of
Calcium transient alternans in blood-perfused ischemic hearts: observations with fluorescent indicator fura red.

Ischemia produces striking electrophysiological abnormalities in blood-perfused hearts that may be caused, in part, by effects of ischemia on intracellular calcium. To test this hypothesis, intrace...
Insulin and igfs enhance hepatocyte differentiation from human embryonic stem cells via the PI3K/AKT pathway

Human embryonic stem cells (hESCs) can be progressively differentiated into definitive endoderm (DE), hepatic progenitors, and hepatocytes, and thus provide an excellent model system for the mechanistic study of hepatocyte differentiation, which is currently poorly understood. Here, we found that insulin enhanced hepatocyte differentiation from hESC-derived DE. Insulin activated the PI3K/AKT pathway, but not the mitogen-activated protein kinase pathway in the DE cells, and inhibition of the PI3K/AKT pathways by inhibitors markedly inhibited hepatocyte differentiation. In addition, insulin-like growth factor 1 (IGF1) and IGF2 also activated the PI3K/AKT pathway in DE cells and their expression was robustly upregulated during hepatocyte differentiation from DE. Furthermore, inhibition of IGF receptor 1 (IGF1R) by a small molecule inhibitor PPP or knockdown of the IGF1R by shRNA attenuated hepatocyte differentiation. Moreover, simultaneous knockdown of the IGF1R and the insulin receptor with shRNAs markedly reduced the activation of AKT and substantially impaired hepatocyte differentiation. The PI3K pathway specifically enhanced the expression of HNF1 and HNF4 to regulate hepatocyte differentiation from DE. Although inhibition of the PI3K pathway was previously shown to be required for the induction of DE from hESCs, our study revealed a positive role of the PI3K pathway in hepatocyte differentiation after the DE stage, and has advanced our understanding of hepatocyte cell fate determination.
Friction in turbulent flow of solids‐gas systems

Two-phase solids-in-air flow was experimentally studied in a once-through circular tube flow system using nominal 25μ and 50μ spherical glass beads. At mass flow ratios up to 1.6, the friction factor was found to be generally higher than that for air flow alone but considerably less than that for a single-phase fluid having a density the same as that of the mixture. The pressure drop experienced by the 2 phase system of 25μ beads and air was found to show true drag reduction. A continuum mechanics analysis showed the viscous stresses and Reynolds stresses to be significantly affected by solid particle addition. On a etudie experimentalement un ecoulement, en deux phases, de matieres solides dans l'air en utilisant un systeme d'ecoulement dans un tube circulaire ainsi que des perles de verre nominales de 25μ et spheriques de 50μ. Pour des rapports d'ecoulement de masse allant jusqu'a 1.6, on a trouve que le coefficient de frottement etait en general plus eleve que dans le cas de l'ecoulement d'air seul, mais bien moindre que lorsqu'il s'agissait d'un fluide en phase simple et ayant la měme densite que celle du melange. On a demontre, au moyen d'une analyse mecanique continue, a deux phases forme d'air et de perles de verre de 25μ produisait une diminution reelle de la force de traǐnee. que les contraintes de viscosite et de Reynolds etaient affectees d'une maniere appreciable par l'addition de particules solides.
Optimal control of infinite horizon partially observable decision processes modelled as generators of probabilistic regular languages

Decision processes with incomplete state feedback have been traditionally modelled as partially observable Markov decision processes. In this article, we present an alternative formulation based on probabilistic regular languages. The proposed approach generalises the recently reported work on language measure theoretic optimal control for perfectly observable situations and shows that such a framework is far more computationally tractable to the classical alternative. In particular, we show that the infinite horizon decision problem under partial observation, modelled in the proposed framework, is λ-approximable and, in general, is not harder to solve compared to the fully observable case. The approach is illustrated via two simple examples.
Improving online incremental speaker adaptation with eigen feature space MLLR

This paper investigates an eigen feature space maximum likelihood linear regression (fMLLR) scheme to improve the performance of online speaker adaptation in automatic speech recognition systems. In this stochastic-approximation-like framework, the traditional incremental fMLLR estimation is considered as a slowly changing mean of the eigen fMLLR. It helps the adaptation when only a limited amount of data is available at the beginning of the conversation. The scheme is shown to be able to balance the transformation estimation given the data and yields reasonable improvements for online systems.
Chronic effects of atrazine on tolerance of a benthic diatom

The effects of prior chronic exposure to atrazine on responses to subsequent acute exposures were investigated using a common benthic diatom. Clonal, axenic cultures of Craticula cuspidata were established from the Platte River (Nebraska) and obtained from a culture collection (unlikely prior exposure to atrazine). All cultures received a chronic 67-d treatment of 1 μg/L atrazine, and growth was monitored using fluorometric detection of chlorophyll a. Chronic atrazine exposure significantly reduced growth rate only during the first day of treatment (p = 0.0001); no significant effect was detected throughout the remainder of the 67-d period. Following the chronic treatment, clones were exposed to six atrazine concentrations (83, 188, 402, 860, 1,782, and 3,250 μg/L) to ascertain whether prior exposure influenced the tolerance of this diatom. Prior chronic exposure had a negative effect on growth following subsequent exposures to higher concentrations. A significant decline in growth was detected on days 7, 9, and 12 between previously exposed and control clones at 83 μg/L of atrazine. The lack of increased tolerance in C. cuspidata after a realistic chronic exposure indicates that the levels of atrazine presently found in many lotic systems may inhibit the growth of periphyton during periods of higher pulses of atrazine characteristic of spring runoff events.
The roles of thermalized and hot carrier diffusion in determining light yield and proportionality of scintillators

Numerical modeling and comparison to experiment in the materials for which suitable parameters have been measured confirm that three of the most important material parameters for predicting proportionality and the related host-dependent light yield (LY) of scintillators are (i) the carrier diffusion coefficients (including hole self-trapping if present, and hot-electron diffusion if unthermalized), (ii) the kinetic order and associated rate constant of nonlinear quenching, and (iii) deep-trapping probability. Thermalized carrier diffusion appears sufficient to describe the main trends in oxides and semiconductors. For heavier halide hosts, it appears necessary to take account of hot-electron diffusion to explain several important host-dependent trends.
Estimates of utility weights in hemophilia: implications for cost-utility analysis of clotting factor prophylaxis

Estimates of preference-weighted health outcomes or health state utilities are needed to assess improvements in health in terms of quality-adjusted life-years. Gains in quality-adjusted life-years are used to assess the cost–effectiveness of prophylactic use of clotting factor compared with on-demand treatment among people with hemophilia, a congenital bleeding disorder. Published estimates of health utilities for people with hemophilia vary, contributing to uncertainty in the estimates of cost–effectiveness of prophylaxis. Challenges in estimating utility weights for the purpose of evaluating hemophilia treatment include selection bias in observational data, difficulty in adjusting for predictors of health-related quality of life and lack of preference-based data comparing adults with lifetime or primary prophylaxis versus no prophylaxis living within the same country and healthcare system.
An action spectrum for phototaxis by pseudoplasmodia of Dictyostelium discoideum

— The sensitivity of phototactic orientation of pseudoplasmodia (slugs) of the cellular slime mold Dictyosrelium discoideum has been measured for white light and monochromatic light using computer aided directional statistics. The zero threshold for white light was found at about 10-5 Ix. An action spectrum for positive phototaxis has been calculated from fluence rate-response curves; it shows two major maxima at about 420 and 440 nm and secondary peaks at 560 and 610 nm. This action spectrum is significantly different from the one for phototactic orientation in Dictyostelium amoebae.
Using artificial anomalies to detect unknown and known network intrusions

Intrusion detection systems (IDSs) must be capable of detecting new and unknown attacks, or anomalies. We study the problem of building detection models for both pure anomaly detection and combined misuse and anomaly detection (i.e., detection of both known and unknown intrusions). We propose an algorithm to generate artificial anomalies to coerce the inductive learner into discovering an accurate boundary between known classes (normal connections and known intrusions) and anomalies. Empirical studies show that our pure anomaly detection model trained using normal and artificial anomalies is capable of detecting more than 77% of all unknown intrusion classes with more than. 50% accuracy per intrusion class. The combined misuse and anomaly detection models are as accurate as a pure misuse detection model in detecting known intrusions and are capable of detecting at least 50% of unknown intrusion classes with accuracy measurements between 75% and 100% per class.
Insomnia in central Pennsylvania.

Objective: Establish the association between insomnia and various physical and mental health symptoms as well as objective measures of sleep disturbance while controlling for age, gender and BMI in a large random sample of the general public. Methods: A subsample (N=1741) was selected for a single-night sleep laboratory evaluation from a larger random sample (N=16,583) of the general public (20–100 years old). Results: The prevalence of insomnia was 7.5% and difficulty sleeping an additional 22.4%. The complaints were more frequent in women and in non-Caucasian minorities. A multivariate logistic regression analysis indicated that depression was the single strongest factor followed by female gender associated with either insomnia or difficulty sleeping. Minority status and a history of colitis, hypertension and anemia were also associated, but to a lesser degree. The final model did not include age, BMI as well as any of the sleep laboratory findings. Conclusion: These findings support the conclusion that mental health variables have the primary independent association with a complaint of insomnia. Other factors including minorities and hypertension are also independently associated, though to a lesser degree. Other primary sleep disorders, e.g., sleep apnea, do not seem to play a major role in insomnia. These findings underscore the fact that insomnia is a symptom associated with a wide variety of mental and physical health problems requiring a proper psychiatric and medical management.
X-linked immunodeficiencies

In the past year, researchers have identified the genes responsible for X-linked severe combined immunodeficiency (encoding a cytokine receptor protein), X-linked agammaglobulinemia (encoding a cytoplasmic tyrosine kinase) and X-linked hyper IgM syndrome (encoding the ligand for CD40). Although these three genes are completely unrelated, it is of interest that all are lineage-specific genes that are involved in the control of lymphocyte proliferation or differentiation.
The neuroendocrinology of primate maternal behavior

In nonhuman primates and humans, similar to other mammals, hormones are not strictly necessary for the expression of maternal behavior, but nevertheless influence variation in maternal responsiveness and parental behavior both within and between individuals. A growing number of correlational and experimental studies have indicated that high circulating estrogen concentrations during pregnancy increase maternal motivation and responsiveness to infant stimuli, while effects of prepartum or postpartum estrogens and progestogens on maternal behavior are less clear. Prolactin is thought to play a role in promoting paternal and alloparental care in primates, but little is known about the relationship between this hormone and maternal behavior. High circulating cortisol levels appear to enhance arousal and responsiveness to infant stimuli in young, relatively inexperienced female primates, but interfere with the expression of maternal behavior in older and more experienced mothers. Among neuropeptides and neurotransmitters, preliminary evidence indicates that oxytocin and endogenous opioids affect maternal attachment to infants, including maintenance of contact, grooming, and responses to separation. Brain serotonin affects anxiety and impulsivity, which in turn may affect maternal behaviors such as infant retrieval or rejection of infants' attempts to make contact with the mother. Although our understanding of the neuroendocrine correlates of primate maternal behavior has grown substantially in the last two decades, very little is known about the mechanisms underlying these effects, e.g., the extent to which these mechanisms may involve changes in perception, emotion, or cognition.
Better Late Than Never? Delayed Enrollment in the High School to College Transition

In this paper, we examine the antecedents and consequences of timing in the transition from high school to college. Using the National Education Longitudinal Study of 1988 (NELS:88), we find that 16 percent of high school graduates postpone enrollment by seven months or more after completing high school. Delayers tend to have some common characteristics: they come from families with few socioeconomic resources, they have performed poorly on standardized tests, they have dropped out of school, and they have exited high school with a GED. We find that even after controlling for these academic and socioeconomic characteristics, students who delay postsecondary enrollment have lower odds of bachelor degree completion. Additionally, we find that delayers are more likely than on-time enrollees to attend less than four-year institutions and to transition to other roles such as spouses or parents before entering college. Controlling for institutional context and life course contingencies, however, does not completely explain the negative relationship between delayed enrollment and degree completion.
Mobile robot obstacle avoidance in a computerized travel aid for the blind

A blind traveler walking through an unfamiliar environment and a mobile robot navigating through a cluttered environment have an important feature in common: both have the kinematic ability to perform the motion, but are depended on a sensory system to detect and avoid obstacles. This paper describes the use of a mobile robot obstacle avoidance system as a guidance device for blind and visually impaired people. Just like electronic signals are sent to a mobile robot's motor controllers, auditory signals can guide the blind traveler around obstacles, or alternatively, they can provide an "acoustic image" of the surroundings. The concept has been implemented and tested in a new traveling aid for the blind, called the Navbelt. Experimental results of subjects traveling with the Navbelt in different surroundings are presented. >
Construction and Characterization of a Lactose-Inducible Promoter System for Controlled Gene Expression in Clostridium perfringens

Clostridium perfringens is a Gram-positive anaerobic pathogen which causes many diseases in humans and animals. While some genetic tools exist for working with C. perfringens, a tightly regulated, inducible promoter system is currently lacking. Therefore, we constructed a plasmid-based promoter system that provided regulated expression when lactose was added. This plasmid (pKRAH1) is an Escherichia coli-C. perfringens shuttle vector containing the gene encoding a transcriptional regulator, BgaR, and a divergent promoter upstream of gene bgaL (bgaR-P(bgaL)). To measure transcription at the bgaL promoter in pKRAH1, the E. coli reporter gene gusA, encoding β-glucuronidase, was placed downstream of the P(bgaL) promoter to make plasmid pAH2. When transformed into three strains of C. perfringens, pAH2 exhibited lactose-inducible expression. C. perfringens strain 13, a commonly studied strain, has endogenous β-glucuronidase activity. We mutated gene bglR, encoding a putative β-glucuronidase, and observed an 89% decrease in endogenous activity with no lactose. This combination of a system for regulated gene expression and a mutant of strain 13 with low β-glucuronidase activity are useful tools for studying gene regulation and protein expression in an important pathogenic bacterium. We used this system to express the yfp-pilB gene, comprised of a yellow fluorescent protein (YFP)-encoding gene fused to an assembly ATPase gene involved in type IV pilus-dependent gliding motility in C. perfringens. Expression in the wild-type strain showed that YFP-PilB localized mostly to the poles of cells, but in a pilC mutant it localized throughout the cell, demonstrating that the membrane protein PilC is required for polar localization of PilB.
Field of View and Target Uncertainty in Visual Search and Inspection

This study is aimed at an improved understanding of the inspection of miniature computer components. It was found, for complex stimuli simulating integrated circuit chips, that subjects failed to detect over half of the targets in a 15- or 16-sec. visual-scan interval. Defects were usually detected quickly or not at all. Removing the time constraint by extending the visual scan interval to 2 min. did not substantially improve detection performance. The elimination of target uncertainty, by placing targets on all stimuli and informing subjects of this fact prior to search, had no apparent effect on inspection errors. Restricting the field of view of subjects to a series of small areas of the stimulus did not enhance the detection of the targets used in this study.
CELLULAR STRESS RESPONSE PATHWAY SYSTEM AS A SENTINEL ENSEMBLE IN TOXICOLOGICAL SCREENING

High costs, long test times, and societal concerns related to animal use have required the development of in vitro assays for the rapid and cost-effective toxicological evaluation and characterization of compounds in both the pharmaceutical and environmental arenas. Although the pharmaceutical industry has developed very effective, high-throughput in vitro assays for determining the therapeutic potential of compounds, the application of this approach to toxicological screening has been limited. A primary reason for this is that while drug candidate screens are directed to a specific target/mechanism, xenobiotics can cause toxicity through any of a myriad of undefined interactions with cellular components and processes. Given that it is not practical to design assays that can interrogate each potential toxicological target, an integrative approach is required if there is to be a rapid and low-cost toxicological evaluation of chemicals. Cellular stress response pathways offer a viable solution to the creation of a set of integrative assays as there is a limited and hence manageable set (a small ensemble of 10 or less) of major cellular stress response pathways through which cells mount a homoeostatic response to toxicants and which also participate in cell fate/death decisions. Further, over the past decades, these pathways have been well characterized at a molecular level thereby enabling the development of high-throughput cell-based assays using the components of the pathways. Utilization of the set of cellular stress response pathway-based assays as indicators of toxic interactions of chemicals with basic cellular machinery will potentially permit the clustering of chemicals based on biological response profiles of common mode of action (MOA) and also the inference of the specific MOA of a toxicant. This article reviews the biochemical characteristics of the stress response pathways, their common architecture that enables rapid activation during stress, their participation in cell fate decisions, the essential nature of these pathways to the organism, and the biochemical basis of their cross-talk that permits an assay ensemble screening approach. Subsequent sections describe how the stress pathway ensemble assay approach could be applied to screening potentially toxic compounds and discuss how this approach may be used to derive toxicant MOA from the biological activity profiles that the ensemble strategy provides. The article concludes with a review of the application of the stress assay concept to noninvasive in vivo assessments of chemical toxicants.
The Caenorhabditis elegans NK-2 class homeoprotein CEH-22 is involved in combinatorial activation of gene expression in pharyngeal muscle

The pharyngeal muscles of Caenorhabditis elegans are single sarcomere muscles used for feeding. Like vertebrate cardiac and smooth muscles, C. elegans pharyngeal muscle does not express any of the known members of the MyoD family of myogenic factors. To identify mechanisms regulating gene expression in this tissue, we have characterized a pharyngeal muscle-specific enhancer from myo-2, a myosin heavy chain gene expressed exclusively in pharyngeal muscle. Assaying enhancer function in transgenic animals, we identified three subelements, designated A, B and C, that contribute to myo-2 enhancer activity. These subelements are individually inactive; however, any combination of two or more subelements forms a functional enhancer. The B and C subelements have distinct cell type specificities. A duplication of B activates transcription in a subset of pharyngeal muscles (m3, m4, m5 and m7). A duplication of C activates transcription in all pharyngeal cells, muscle and non-muscle. Thus, the activity of the myo-2 enhancer is regulated by a combination of pharyngeal muscle-type-specific and organ-specific signals. Screening a cDNA expression library, we identified a gene encoding an NK-2 class homeodomain protein, CEH-22, that specifically binds a site necessary for activity of the B subelement. CEH-22 protein is first expressed prior to myogenic differentiation and is present in the same subset of pharyngeal muscles in which B is active. Expression continues throughout embryonic and larval development. This expression pattern suggests CEH-22 plays a key role in pharyngeal muscle-specific activity of the myo-2 enhancer.
Clues for understanding hospital variation among obstetric services.

any reports have chronicled the large variation in US in performance and outcomes? The authors address this in a 6 M obstetric care with total cesarean rates ranging from 6.1% to 69.9%; hospital rates of early elective delivery rates varying from 0% to 83%; and thirdand fourth-degree laceration rates swinging from 0.5% to 9.5% among delivery services. In California, we also see significant variation within all levels of care, among university hospitals, among large urban facilities, and even among small rural facilities, for morbidity indicators as well as for process indicators such as failed labor induction. If we could only understand what drives such variation, we would be well on our way toward improving care for our entire birthing population and not just facility by facility, or so quality improvement science would suggest. There must be some objective criteria that establish a recipe for success. Would that it be so easy. In this issue, Korst et al present a series of well-designed and carefully executed studies to search for this elusive goal. They first describe a comprehensive survey with 185 questions that covered hospital staffing (eg, all types of direct and support providers), clinical resources (eg, pharmacy and blood bank 24 hours a day 7 days a week, resources for severe obese patients), and patient care activities (eg, protocols for emergencies, drills, and educational programs). The surveyors were persistent and they achieved a remarkable response rate of > 96%. Not surprisingly, they found that the 26 staff-model health maintenance organization facilities had 100% in-house obstetricians and 24 hours a day 7 days a week availability of specialists. The 26 teaching facilities were more varied, but the 187 community facilities with private practice providers showed great variation for most of the services. Clearly there is more opportunity for investigation among subdivisions of this population of hospitals that accounts for the large majority of maternity care in the United States. But the overarching question remains: does the variation in maternity services and capabilities help explain the variation
Streamlining Appointment, Promotion, and Tenure Procedures to Promote Early-Career Faculty Success

A critical component of the progression of a successful academic career is being promoted in rank. Early-career faculty are required to have an understanding of appointment, promotion, and tenure (APT) guidelines, but many factors often impede this understanding, thwarting a smooth and planned promotion pathway for professional advancement. This article outlines the steps taken by an APT committee to improve the promotion process from instructor to assistant professor. Six sigma's DMAIC improvement model was selected as the guiding operational framework to remove variation in the promotion process. After faculty handbook revisions were made, several checklists developed, and a process review rubric was implemented; recently promoted faculty were surveyed on satisfaction with the process. Faculty opinions captured in the survey suggest increased transparency in the process and perceived support offered by the APT committee. Positive outcomes include a strengthened faculty support framework, streamlined promotion processes, and improved faculty satisfaction. Changes to the APT processes resulted in an unambiguous and standardized pathway for successful promotion.