cssi/SciSciGPT-SciSciNet huggingface dataset:
Mapping urban forest tree species using IKONOS imagery: preliminary results.

A stepwise masking system with high-resolution IKONOS imagery was developed to identify and map urban forest tree species/groups in the City of Tampa, Florida, USA. The eight species/groups consist of sand live oak (Quercus geminata), laurel oak (Quercus laurifolia), live oak (Quercus virginiana), magnolia (Magnolia grandiflora), pine (species group), palm (species group), camphor (Cinnamomum camphora), and red maple (Acer rubrum). The system was implemented with soil-adjusted vegetation index (SAVI) threshold, textural information after running a low-pass filter, and brightness threshold of NIR band to separate tree canopies from non-vegetated areas from other vegetation types (e.g., grass/lawn) and to separate the tree canopies into sunlit and shadow areas. A maximum likelihood classifier was used to identify and map forest type and species. After IKONOS imagery was preprocessed, a total of nine spectral features were generated, including four spectral bands, three hue–intensity–saturation indices, one SAVI, and one texture image. The identified and mapped results were examined with independent ground survey data. The experimental results indicate that when classifying all the eight tree species/ groups with the high-resolution IKONOS image data, the identifying accuracy was very low and could not satisfy a practical application level, and when merging the eight species/groups into four major species/groups, the average accuracy is still low (average accuracy = 73%, overall accuracy = 86%, and κ = 0.76 with sunlit test samples). Such a low accuracy of identifying and mapping the urban tree species/groups is attributable to low spatial resolution IKONOS image data relative to tree crown size, to complex and variable background spectrum impact on crown spectra, and to shadow/shaded impact. The preliminary results imply that to improve the tree species identification accuracy and achieve a practical application level in urban area, multi-temporal (multi-seasonal) or hyperspectral data image data should be considered for use in the future.
Vertex-Function Poles and the Bootstrap Condition in Field Theory

We discuss the implications of maintaining finite mass renormalization when the wave-function renormalization constant ${Z}_{3}$ of an elementary particle is set equal to zero, making only the approximations of two-particle unitarity. We show that this defines a field-theory bootstrap for the elementary particle which is completely equivalent to the usual type of bootstrap based on the $\frac{N}{D}$ method. As ${Z}_{3}$ goes to zero the vertex function and inverse propagator develop poles which move to ${\ensuremath{\mu}}^{2}$, the elementary-particle mass, in the limit. For nonzero ${Z}_{3}$ this pole does not contribute to the scattering amplitude, but at ${Z}_{3}=0$ it cancels the elementary-particle pole in the single-particle reducible part, leaving the dynamical pole in the irreducible part. We suggest, further, that in this limit the bootstrapped state is a Regge pole.
The economic factor in environmental studies

Our environmental options are limited. We must, therefore, choose between desirable alternatives, and the cost of what we choose to do is measured by the alternative we have decided to forego. Choice requires that we openly identify and rank our feasible alternatives in terms of some common denominator. All the available common denominators are imperfect measures of some more fundamental unit, but money is familiar and widely used by individuals to indicate their preferences. Economists have the tools to rank alternatives in money terms, the agony is that we must be prepared for conclusions which conflict with our cherished preconceptions.
Taste bud development in the channel catfish

Taste bud formation in channel catfish is first seen to occur in stage 39 embryos, when taste bud primordia (stage 1), consisting of three to five cells, including a single calretinin-positive cell, can be recognized within the oropharyngeal cavity and maxillary barbels. Within a short time (stage 40), stage 2 taste bud primordia are apparent and include two or three calretinin-positive cells. The number of calretinin-positive cells continues to increase (stage 3), and the primordia begin to erupt as mature taste buds (stage 4) by embryonic stage 48. This same pattern of taste bud development characterizes other regions of the head, with calretinin-positive cells first detected around the mouth and on the other barbels by stage 41 and on the rest of the head by stage 48. The development of trunk taste buds lags far behind that of the head, with the first calretinin-positive cells occurring on the lobes of the caudal fin by stage 48 and on the remaining fins by stage 50. Taste bud primordia on the trunk proper do not begin to appear until stage 53, when the larvae begin to feed, and these receptors begin to erupt only in 1-week-old larvae. Fibers of the facial nerve, which innervate all external taste buds, ramify within the ectoderm prior to the first appearance of taste bud primordia or their precursors. J. Comp. Neurol. 482:1–16, 2005. © 2004 Wiley-Liss, Inc.
Cortical Spreading Depression and Migraine

Cortical spreading depression, a slowly propagating wave of transient neuronal and glial depolarization, is widely accepted as the electrophysiologic substrate of migraine aura and a trigger for headache. Recent clinical and experimental evidence reinforces the putative role of cortical spreading depression in migraine pathophysiology. Imaging studies in migraineurs demonstrated hemodynamic changes consistent with cortical spreading depression during aura, whereas recent animal studies helped unravel pathophysiologic aspects such as the triggering mechanisms, genetic and hormonal modulation, and potential therapeutic targets. Here, we provide an overview of recent advances in our understanding of migraine pathophysiology and treatment.
Olfactory Coding: Random Scents Make Sense

Stimulating arbitrary collections of as few as 300 neurons in the primary olfactory cortex of mice suffices for associative learning independent of any odor stimulation. Thus, programmed spatial relationships may not exist in piriform cortex, making flexible random associations the rule.
American foulbrood incidence in some US and Canadian honeys

On a teste a l'aide de la methode de Hansen la presence de spores de Bacillus larvae (BL), agent de la loque americaine (AFB), dans 82 echantillons de miel. Sept analyses se sont revelees positives. Le miel est etale sur une surface de gelose. Description de la methode de culture, des caracteres culturaux et biochimiques des colonies isolees
Lysosomal stabilizing effect of chlorphentermine in the rabbit alveolar macrophage.

Abstract 1. Rabbits were injected (i.p.) daily with chlorphentermine (30 mg/kg), 5 days a week for 7 weeks. 2. Alveolar macrophages were collected from the lungs of control and treated rabbits by pulmonary lavage. 3. When compared to controls, the latencies of the lysosomal acid hydrolases, acid phosphatase and β-N-acetyl glucosaminidase were increased in lysosome-containing fractions from alveolar macrophages of treated rabbits. The same results were obtained when chlorphentermine was incubated in vitro with a lysosomal fraction from macrophages of normal rabbits. 4. The increased latency of lysosomal enzymes following chlorphentermine treatment can be explained by the drug's ability to stabilize lysosomal membranes.
Is Social Media Too Social for Class? A Case Study of Twitter Use

This qualitative case study examined Twitter use by undergraduate and graduate students in three classes. Previous studies have shown that while some faculty use Twitter, few are incorporating it into classes despite many recommendations for such use. This study examined how students perceived Twitter as a classroom tool. As an optional activity, many started with Twitter but fewer continued through the semester. The study reports on content and counts of tweets as well as student self-reports on usage and interest. The researchers found students enjoyed being consumers of tweets but seldom retweeted or replied. Incorporating Twitter in courses will require careful consideration of scaffolding, modeling, privacy and course design. Questions remain as to whether the informal social focus of Twitter may overwhelm attempts to use it in more structured educational settings.
Tissue-specific mutagenesis by N-butyl-N-(4-hydroxybutyl)nitrosamine as the basis for urothelial carcinogenesis

Bladder cancer is one of the few cancers that have been linked to carcinogens in the environment and tobacco smoke. Of the carcinogens tested in mouse chemical carcinogenesis models, N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN) is one that reproducibly causes high-grade, invasive cancers in the urinary bladder, but not in any other tissues. However, the basis for such a high-level tissue-specificity has not been explored. Using mutagenesis in lacI (Big Blue™) mice, we show here that BBN is a potent mutagen and it causes high-level of mutagenesis specifically in the epithelial cells (urothelial) of the urinary bladder. After a 2-6-week treatment of 0.05% BBN in the drinking water, mutagenesis in urothelial cells of male and female mice was about two orders of magnitude greater than the spontaneous mutation background. In contrast, mutagenesis in smooth muscle cells of the urinary bladder was about five times lower than in urothelial tissue. No appreciable increase in mutagenesis was observed in kidney, ureter, liver or forestomach. In lacI (Big Blue™) rats, BBN mutagenesis was also elevated in urothelial cells, albeit not nearly as profoundly as in mice. This provides a potential explanation as to why rats are less prone than mice to the formation of aggressive form of bladder cancer induced by BBN. Our results suggest that the propensity to BBN-triggered mutagenesis of urothelial cells underlies its heightened susceptibility to this carcinogen and that mutagenesis induced by BBN represents a novel model for initiation of bladder carcinogenesis.
Staged repair of extensive aortic aneurysms

Background. We adopted a two-stage approach (elephant trunk procedure) in the repair of extensive aortic aneurysms in 1991, performing 241 procedures in 155 patients. Methods. Reversed elephant trunk (graft replacement of the descending thoracic aorta followed by ascending/ arch replacement) was performed in 18 patients. All other patients underwent conventional staged repair. The first stage was performed in 137 patients, with 86 patients returning for the second stage. Results. First stage 30-day mortality was 9.5% (13 of 137). There was no second stage immediate neurologic deficit. Second stage mortality was 7.0% (6 of 86). During the interval of 31 days to 6 weeks after stage one, mortality was 10 of 124 (8%). Seven of the 10 interval deaths (70%) were due to rupture of the untreated aortic segment. The mortality rate was 32.1% (18 of 56) in the group of patients who did not return for the second stage repair. Conclusions. Extensive aortic aneurysms can be repaired with acceptable morbidity and mortality using the elephant trunk technique. After stage one, prompt treatment of the remaining aneurysm is crucial to success.
Isolation and characterization of 21 microsatellite loci for the federally threatened yellowfin madtom ( Noturus flavipinnis ) with cross species amplification in N. baileyi

We isolated 21 microsatellite loci from Noturus flavipinnis, a federally threatened freshwater fish. Nine loci were polymorphic with an average of 1.48 alleles and an average observed and expected heterozygosity of 0.092 and 0.096, respectively. All loci conformed to Hardy–Weinberg expectations, and all pairs of loci showed no signs of genotypic disequilibrium. Three of these loci were found to cross amplify in N. baileyi. These markers should prove useful in the conservation efforts and genetic monitoring of these rare fish species.
Language Placement Exams for Heritage Speakers of Spanish: Learning from Students' Mistakes

Student admission into heritage language programs is usually determined by locally designed placement exams. Howevel; there are no norms to guide language teaching professionals in the assessment of this student population. This study looks at placement exams completed by heritage learners of Spanish at the University of Houston. The quantijication and analysis of the verb morphology section from this archival data describe the variation present in the linguistic systems of these learners, making it possible (1) to recognize gaps in the learners' linguistic systems and (2) to identijy major differences between academic Spanish and the students' home-variety language. This information may be useful in the design of a placement exam based on empirical research, and may also serve as a guide for syllabi design and teaching practice.
Sex differences in the uptake of orthodontic services among adolescents in the United States.

Introduction The purpose of this study was to test whether girls are treated orthodontically for milder occlusal issues than are boys, thus accounting for the greater uptake of orthodontic services among girls compared with boys. Methods The dental aesthetic index (DAI) was used to score the severity of esthetic occlusal issues in 357 white adolescents. Half of the subjects were from private practices; the others were from a university specialty clinic. Results Average DAI scores were statistically significantly lower (milder) in girls than boys in both venues; this confirms the assumption that the actual uptake of services is greater in girls because of heightened concern for their esthetic occlusal issues. Average DAI scores predictably were higher in the teaching setting because of selection for more complex cases, but the sex difference was still evident statistically. There was no association between DAI score and age at the start of treatment among these adolescents. Spacing and incisor irregularity showed the greatest sex differences among the DAI variables, possibly because girls are more attuned to these esthetic issues. Conclusions These results complement studies that have recorded adolescents' perceptions of orthodontic need. The actual uptake of orthodontic treatment is greater in girls because they (and their parents) seek treatment for milder occlusal issues.
Expanded secondary craters in the Arcadia Planitia region, Mars: Evidence for tens of Myr-old shallow subsurface ice

Abstract A range of observations indicates widespread subsurface ice throughout the mid and high latitudes of Mars in the form of both pore-filling and excess ice. It is generally thought that this ice was recently emplaced and is not older than a hundred thousand to a few millions of years old based on ice stability and orbital-induced climate change. We analyze the distribution of subsurface ice in Arcadia Planitia, located in the northern mid latitudes, by mapping thermokarstically expanded secondary craters, providing additional evidence for extensive excess ice down to fairly low latitudes (less than 40°N). We further infer the minimum age of this subsurface ice based on the ages of the four primary craters that are thought to be the source of a large portion of these secondaries, which yields estimates on the order of tens of millions of years old – much more ancient than anticipated. This estimated ancient age suggests that ice can be preserved in the shallow subsurface for long periods of time, at least in some parts of Arcadia Planitia where expanded secondary craters are especially abundant. We estimate the amount of ice lost to sublimation during crater expansion based on measurements of expanded secondary craters in HiRISE Digital Terrain Models. The loss is equivalent to a volume of ice between ∼140 and 360 km 3 , which would correspond to a global layer of 1–2.5 mm thick. We further argue that much more ice (at least 6000 km 3 ) is likely preserved beneath the un-cratered regions of Arcadia Planitia since significant loss of this excess ice would have caused extensive terrain dissection and the removal of the expanded secondary craters. Both the loss of ice due to secondary crater expansion and the presence of this ice today have implications for the martian climate.
The identification of an asymmetric complex of nicotinamide adenine dinucleotide and pig heart cytoplasmic malate dehydrogenase

Summary Examination of the two major crystalline forms, type A and type C, of pig heart cytoplasmic malate dehydrogenase (s-MDH) has revealed that type C crystals are composed of enzyme molecules with one mole of nicotinamide adenine denucleotide bound per mole of enzyme, Type A crystals are devoid of bound coenzyme. The NAD+ can be readily removed by dialysis or gel filtration after type C crystals have been dissolved. The binding of 1 mole of NAD+ results in the formation of an asymmetric complex in which one of the two identical polypeptide chains composing native s-MDH undergoes a small but definitive conformational change. These data are consistent with observed difference in crystallographic properties of the s-MDH subunits.
Atomic flame reactions involving N atoms, H atoms and ozone

Atomic recombinations involving nitrogen atoms, hydrogen atoms and ozone - emission spectrum - absorption studies
Tail negative dependence and its applications for aggregate loss modeling

Abstract Tail order of copulas can be used to describe the strength of dependence in the tails of a joint distribution. When the value of tail order is larger than the dimension, it may lead to tail negative dependence. First, we prove results on conditions that lead to tail negative dependence for Archimedean copulas. Using the conditions, we construct new parametric copula families that possess upper tail negative dependence. Among them, a copula based on a scale mixture with a generalized gamma random variable (GGS copula) is useful for modeling asymmetric tail negative dependence. We propose mixed copula regression based on the GGS copula for aggregate loss modeling of a medical expenditure panel survey dataset. For this dataset, we find that there exists upper tail negative dependence between loss frequency and loss severity, and the introduction of tail negative dependence structures significantly improves the aggregate loss modeling.
FATIGUE CRACK CLOSURE AND RESIDUAL DISPLACEMENT MEASUREMENTS ON ALUMINUM ALLOYS

—Ultrasonic bulk measurement technique was used to measure crack closure and a clip-on gage surface measurement technique was used to measure residual displacement at the crack tip of a propagating fatigue crack in 2219 and 7075 aluminum alloys. Experiments were carried out in vacuum, humid air, dry O2 gas, N2 gas, and deuteriated water vapor environments to evaluate effects of environments on residual strain and crack closure loads. It was observed that the closure load detected by ultrasonics decreased with introduction of humidity while the residual strain parameter dincreased with the humidity. The results are modeled as a build-up of oxide layer in addition to strengthening of asperities on the fracture surface. In the light of these observations, the effectiveness of surface and bulk measurements is evaluated. The results demonstrate that surface measurements are not always representative of the bulk behavior and use of such measurements in predictive analysis for fatigue can be misleading.
Hydrocarbon chain packing and the effect of ethanol on the thermotropic phase behavior of mixed-chain phosphatidylglycerols.

Abstract Previous studies in this laboratory have delineated the relationship between the acyl chain asymmetry of mixed-chain phosphatidylcholines and the effect of ethanol concentration ([EtOH]) on their melting behavior (Li et al., Biophys J., 70 (1996) 2784–2794). This present investigation extends these findings to another phospholipid family by using high-resolution differential scanning calorimetry (DSC) to characterize the effect of ethanol concentration on the main phase transition temperature (Tm) of five molecular species of mixed-chain phosphatidylglycerol (PG). For C(14):C(18)PG, C(15):C(17)PG, C(16):C(16)PG, and C(17):C(15)PG, a biphasic profile in the Tm versus [EtOH] plot was observed, and the minimum in the plot for each PG occurred at 33, 15, 19, and 36 mg/ml, respectively. This biphasic behavior is typical of phospholipids whose acyl chain asymmetry is fairly small. For C(18):C(14)PG, only a linear decrease in the Tm was observed as a function of ethanol concentration; this effect is characteristic of highly asymmetric phospholipids. Our DSC results obtained with mixed-chain PG in the presence of ethanol demonstrate that the acyl chain asymmetry of the five lipids studied can be ranked as follows: C(15):C(17)PG
Detection of Particle-Associated Enteroviruses from Raw and Treated Sewage and Lake Michigan Harbor Water

Abstract Suspended solids from raw sewage, various stages of wastewater treatment, and Milwaukee Harbor water were examined for associated enteroviruses. The solids were sedimented by centrifugation, and enteroviruses associated with them were eluted by homogenization in fetal bovine serum, analyzed quantitatively by plaque assay on Buffalo green monkey kidney cells, and identified by neutralization with Lim Benyesh-Melnick pooled antisera. Viruses were found at concentrations within approximately one order of magnitude in sediments from all samples. Nine different enteroviruses were identified. All three types of poliovirus were detected in terminally treated (chlorinated) sewage, but the temperature-sensitive marker was not detected in the poliovirus strains isolated from chlorinated samples. Together these data indicate that exploitation of the association of viruses with suspended particles leads to a simple rapid means of monitoring virus distribution in sewage and natural waters.
Effect of dynorphin-(1–13) and related peptides on respiratory rate and morphine-induced respiratory rate depression

Abstract Previous studies from our laboratory have shown that the opioid peptide dynorphin-(1–13), although not analgesic when given by itself, can inhibit morphine-induced analgesia in naive mice and potentiate it in morphine tolerant mice. In the present study, we examined the effect of dynorphin-(1–13) with two other dynorphin-like peptides, α-neoendorphin and dynorphin-(1–10) amide, on respiration. Our results show that none of the peptides studied had any significant activity on the respiratory rate in mice when given alone. However, in the presence of morphine, dynorphin-(1–13) antagonized the morphine-induced respiratory rate depression in morphine-tolerant animals; α-neoendorphin enhanced the morphine-induced respiratory rate depression in naive but had no effect in morphine-tolerant animals and dynorphin-(1–10) amide had no modulatory effect on the morphine-induced respiratory rate depression in either group of animals.
Introduction to the Issue: Tools That Support Literacy Education

Students need to be able to understand and use technologies as part of learning (ISTE Technology Foundation Standards for All Students, n.d.). Conversations about technology in education often focu...
Incorporation of labeled precursors into proteins and nucleic acids of nuclei of regenerating liver.

Abstract The incorporation of glycine-1- 14 C and adenine-8- 14 C into nuclear proteins and nucleic acids, respectively, of regenerating liver has been determined at various intervals following partial hepatectomy of rats. The specific activities of acid-insoluble nuclear proteins reached peaks at 19 hr and 37 to 43 hr after partial hepatectomy. Initial peaks for nuclear histones were broader and reached maxima at 22 hr. Relative to unoperated controls, the accentuation of incorporation of labeled glycine into histones of regenerating liver nuclei was greater than the accentuation of incorporation into other nuclear proteins. Peaks of specific activities for nuclear RNA adenine were reached at 19 and 42.5 hr while peaks for DNA adenine were found at 26 and 42.5 hr. Mitotic peaks were observed at 31 and 42.5 hr. Histone synthesis appears to proceed during a longer portion of the pre-mitotic cycle than does DNA synthesis. However, at the peaks of incorporation of labeled precursors, there is a much greater proportionate rise above normal for DNA than for histones.
The state-owned enterprise as an entrepreneurial substitute in developing countries: the case of nitrogen fertilizer.

Abstract Variations in the conditions of entry across different sectors of industry suggest a role for state-owned enterprises in developing countries as entrepreneurial substitutes. This role is explored in a case study of the nitrogen fertilizer industry. Limited access to capital by private local firms and the limited incentive of multinationals to invest where control of technology is separate from control over production explain why ammonia plants are state-owned in most developing countries. The evolution of the industry in India and elsewhere is examined. The implications of entrepreneurial substitution for existing theories of state ownership are laid out.
Social phobia and separation anxiety symptoms in community and clinical samples of children and adolescents

ABSTRACT Objective To examine the developmental progression and pattern of self-reported symptoms of social phobia (SP) and separation anxiety (SA) in community ( n = 2,384) and clinical ( n = 217) samples of children and adolescents, using a cross-sectional method. Method Subjects were cross-classified by age, gender, and race. Using mean scores on the SP and SA subscales of the Multidimensional Anxiety Scale for Children, 4 categories of children were established: HighSP/HighSA, HighSP/LowSA, LowSP/HighSA, and LowSP/LowSA. Data were analyzed using a generalized logit model. Results Community sample: Preadolescents and females reported more symptoms of HighSP/HighSA and LowSP/HighSA than adolescents and males. White children reported more symptoms of HighSP/LowSA, while the opposite pattern was found among African-American children. Clinical sample: Similar to the community sample, preadolescents reported more symptoms of HighSP/HighSA. However, clinical males reported more symptoms of LowSP/HighSA than clinical females. Conclusions In general, adolescents endorsed more symptoms of SP and fewer symptoms of SA than preadolescent children. Irrespective of age, white children endorsed more symptoms of SP and fewer symptoms of SA than African-American children. In the community sample, preadolescent boys endorsed more symptoms of SA and fewer symptoms of SP, suggesting a possible referral bias.
Integral Equations for Electrostatics Problems with Thin Dielectric or Conducting Layers

Integral equations for the electric charge on continuous, arbitrarily thin, dielectric or conducting layers in axially symmetric geometries have been derived. When discretized, these equations become Boundary Element Method (BEM) equations for the charge. While the only boundary conditions enforced are continuity of potential and normal electrical displacement, the result is shown to be consistent with the boundary conditions used in the Charge Simulation Method (CSM) and the Finite Element Method (FEM) formulations of the problem. The method has the advantages over CSM that it requires only half the number of unknowns and it can be used to model the fields near the thin layer without using large numbers of unknowns. It has the advantage over FEM that only the thin layer surface need be discretized rather than the entire volume.
Effect of human corneal fibroblasts on lymphocyte proliferation in vitro.

Abstract Cocultivation of human corneal fibroblasts (CFB) with allogeneic peripheral blood mononuclear cells (PBL) induced a minimal lymphocyte proliferative response, even when the fibroblasts had been pre-treated with interferon-gamma (IFN-γ) and were HLA-DR positive. IFN-γ-treated CFB did not express detectable HLA-DQ alloantigens. Cocultivation of CFB with PBL in the presence of Concanavalin A (Con A) or Phytohemagglutinin inhibited mitogen-induced lymphocyte proliferation by 40–90% relative to PBL cultured without CFB. Induction of HLA-DR expression on the CFB did not alter their inhibitory properties. Addition of indomethacin to cultures reversed the effect of CFB on Con A responses. However, no difference between proliferative responses to HLA-DR positive or negative CFB was seen in the presence of indomethacin. This weak response to induced Class II alloantigens on CFB suggests that induction of Class II alloantigens on corneal stroma alone may be insufficient to sensitize a recipient for Class II alloantigen-driven corneal graft rejection.
Teaching error disclosure: Advanced communication skills training for residents

AbstractDisclosing errors to patients is an advanced communication skill necessary in clinical practice but traditionally not taught during residency training. We developed an educational seminar for senior residents utilizing didactic, small group discussion, and role play that incorporates principles of error disclosure. Our objectives were to improve resident's knowledge of the key components of disclosing medical errors to patients and to provide opportunity to practice communicating medical error in a safe environment. We assessed whether residents are participating in error disclosure and compared self-rated preparedness to disclose an error before and after the teaching session. Nearly all residents (94%) reported that learning about disclosure of medical errors is a very important part of residency training and 58% of residents had already participated in a disclosure discussion. Residents reported they were significantly more prepared to disclose medical errors to patients after participating in ...
Science linking environmental contaminant exposures with fertility and reproductive health impacts in the adult male

In the field of reproductive environmental health there remain many unanswered questions regarding the impact of the environment on male reproductive health. Suggested needs include studies that target populations with high exposure to chemicals, including phthalates and bisphenol A. We also need to identify susceptibility factors and critical exposure windows (life stages) that may increase a man's risk of infertility. Finally, we need to develop methods to better study mixtures of chemicals and develop methods to assess clinical reproductive outcomes of human exposure to the ever-growing list of chemicals.
Choreographing the Fly's Danse Macabre

In several species, immune signaling networks are emerging as critical modulators of disease resistance, energy metabolism, and aging. In this issue of Cell Metabolism, Ren et al. (2007) lay the groundwork for dissecting the mechanisms of this coordination by characterizing the interplay between microbial pathogens and aging in the fly.
Synaptosomal calcium influx is activated by sodium fluoride

Neuronal calcium channels can be modulated by changes in membrane potential or by activation of channel-associated receptors. The latter may be modulated by guanine nucleotide binding proteins. NaF, which activates guanine nucleotide binding proteins, caused a large stimulation of 45Ca2+ uptake by synaptosomes prepared from rat brain. Stimulation of 45Ca2+ influx by NaF (i) was apparent in media containing either 5 mM-K+ or 50 mM-K+, (ii) was slower than the fast-phase of voltage-dependent 45Ca2+ influx but continued for a longer period of time than did depolarization-induced 45Ca2+ influx, and (iii) was not mimicked or modified by a number of drugs, including ouabain, dinitrophenol, sodium azide or sodium vanadate. These results are consistent with the hypothesis that NaF activates a guanine nucleotide binding protein associated with receptor-coupled calcium channels, resulting in stimulation of calcium influx.
Mutations of the S4‐S5 linker alter activation properties of HERG potassium channels expressed in Xenopus oocytes

Voltage-sensitive K+ channels open in response to membrane depolarization and permit the transmembrane movement of K+ in proportion to its electrochemical driving force. These channels are formed from the co-assembly of four subunits that each contain six (S1-S6) transmembrane domains. Transition of a channel from a non-conducting closed state to a conductive open state in response to membrane depolarization is preceded by outward movement of the positively charged S4 transmembrane domain (Papazian et al. 1991; Aggarwal & MacKinnon, 1996; Larsson et al. 1996) that produces the bulk of the on-gating current (Stuhmer et al. 1991; Perozo et al. 1992). The reversal of this process by membrane hyperpolarization produces an off-gating current and channel closure (deactivation). It is not known what couples the movement of the S4 domain to channel opening. However, it is likely that movement of this domain is physically linked to movement of a ‘gate’ that otherwise occludes the channel pore in a closed state. Mutations in the intracellular region that links transmembrane domains S4 and S5, the S4-S5 linker, of Shaker K+ channels alter ion selectivity and single channel conductance (Slesinger et al. 1993). Based on these and other findings, Durell & Guy (1992) proposed that the S4-S5 linker is the activation gate of voltage-activated K+ channels. More recently, it was reported that the activation gating properties of chimeric channels made from Kv2.1 and Kv3.1 K+ channels are determined by the S4-S5 linker (Shieh et al. 1997). In addition, state-dependent modification of residues in the S4-S5 linker of Shaker K+ channels by thiol reactive chemicals suggests that this region moves in concert with the S4 transmembrane domain (Holmgren et al. 1996). HERG (human ether-a-go-go-related gene) channel subunits co-assemble to form channels that conduct a delayed rectifier K+ current (IKr) important for repolarization of cardiac myocytes (Sanguinetti et al. 1995; Trudeau et al. 1995). To further explore the role of the S4-S5 linker in the activation of K+ channels, we studied the functional effects of charge-altering mutations in this region of HERG (Warmke & Ganetzky, 1994) channels expressed in Xenopus oocytes.
An experimental test for lineage-specific position effects on alcohol dehydrogenase (Adh) genes in Drosophila

Independent transgene insertions differ in expression based on their location in the genome; these position effects are of interest because they reflect the influence of genome organization on gene regulation. Position effects also represent potentially insurmountable obstacles to the rigorous functional comparison of homologous genes from different species because (i) quantitative variation in expression of each gene across genomic positions (generalized position effects, or GPEs) may overwhelm differences between the genes of interest, or (ii) divergent genes may be differentially sensitive to position effects, reflecting unique interactions between each gene and its genomic milieu (lineage-specific position effects, or LSPEs). We have investigated both types of position-effect variation by applying our method of transgene coplacement, which allows comparisons of transgenes in the same position in the genome of Drosophila melanogaster. Here we report an experimental test for LSPE in Drosophila. The alcohol dehydrogenase (Adh) genes of D. melanogaster and Drosophila affinidisjuncta differ in both tissue distribution and amounts of ADH activity. Despite this striking regulatory divergence, we found a very high correlation in overall ADH activity between the genes of the two species when placed in the same genomic position as assayed in otherwise Adh-null adults and larvae. These results argue against the influence of LSPE for these sequences, although the effects of GPE are significant. Our new findings validate the coplacement approach and show that it greatly magnifies the power to detect differences in expression between transgenes. Transgene coplacement thus dramatically extends the range of functional and evolutionary questions that can be addressed by transgenic technology.
Triage: Performance differentiation for storage systems using adaptive control

Ensuring performance isolation and differentiation among workloads that share a storage infrastructure is a basic requirement in consolidated data centers. Existing management tools rely on resource provisioning to meet performance goals; they require detailed knowledge of the system characteristics and the workloads. Provisioning is inherently slow to react to system and workload dynamics and, in the general case, it is not practical to provision for the worst case.We propose a software-only solution that ensures predictable performance for storage access. It is applicable to a wide range of storage systems and makes no assumptions about workload characteristics. We use an online feedback loop with an adaptive controller that throttles storage access requests to ensure that the available system throughput is shared among workloads according to their performance goals and their relative importance. The controller considers the system as a “black box” and adapts automatically to system and workload changes. The controller is distributed to ensure high availability under overload conditions, and it can be used for both block and file access protocols. The evaluation of Triage, our experimental prototype, demonstrates workload isolation and differentiation in an overloaded cluster file-system where workloads and system components are changing.
Synaptic transmission in a sodium-free medium.

THE observation of Lorente de No1, that small frog axons (“Et fibres”) are excitable in media where the sodium is totally replaced by certain quaternary ammonium, ions, has since been extended to crustacean muscle fibres2, frog A-fibres3,4, frog spinal ganglion cell-bodies5 and mammalian striated muscle6,7 and nerve8 fibres. Such findings suggested that the membrane of muscle fibres and neurones in different species was capable of maintaining excitability when the external sodium was replaced by a favourable cation possessing a tetracovalent nitrogen atom. The purpose of the present study was to determine whether synaptic transmission could also be maintained in sodium-free media. It is well known that the membrane characteristics of the junctional region are somewhat different from those possessing the conductile activity, since the post-synaptic membrane produces graded responses by the action of the transmitter released from the pre-synaptic membrane. It was previously reported9 that in the frog spinal ganglion cell-bodies hydrazinium ion was the most favourable substitute for sodium ion; the action potentials of cell-bodies being very similar to those observed in normal Ringer. An attempt to replace sodium ion by hydrazinium ion was quite successful; the neuromuscular transmission was restored in the sodium-free hydrazinium solution.
Fast correspondence-based system for shape retrieval

Several recently published shape retrieval systems have achieved high accuracy on a benchmark 1400-shape dataset. However, some of these systems have high pairwise shape matching costs due to their use of structural matching or flexible correspondence. The purpose of this paper is to demonstrate that a relatively simple shape retrieval system based on fixed point correspondences can achieve accuracy comparable with the two most accurate prior systems, at significantly higher speed. High accuracy is achieved by using a stable curve normalization procedure and example-based retrieval. High speed is achieved by three techniques: single key-point alignment, fixed correspondences, and PCA-based dimensionality reduction. The system is completely automatic and does not require that the database shapes have class labels.
Decrease in serum alkaline phosphatase activity produced by magnesium depletion in rats.

SummaryThirty-day-old rats were fed a magnesium-deficient diet for up to 34 days. There was a decrease in serum alkaline phos-phatase activity which was reversed by adding magnesium chloride to the diet. The rats also developed hypophosphatemia and were mildly hypercalcemic for 14 days. Approximately one-third of the rats had phosphoethanolamin-uria. These changes are similar to those seen in infantile hypophosphatasia in man. Magnesium deficiency in rats may induce a biochemical lesion similar to that of hypophosphatasia in man.
Wnt, Hedgehog and Junctional Armadillo/β-Catenin Establish Planar Polarity in the Drosophila Embryo

To generate specialized structures, cells must obtain positional and directional information. In multi-cellular organisms, cells use the non-canonical Wnt or planar cell polarity (PCP) signaling pathway to establish directionality within a cell. In vertebrates, several Wnt molecules have been proposed as permissible polarity signals, but none has been shown to provide a directional cue. While PCP signaling components are conserved from human to fly, no PCP ligands have been reported in Drosophila. Here we report that in the epidermis of the Drosophila embryo two signaling molecules, Hedgehog (Hh) and Wingless (Wg or Wnt1), provide directional cues that induce the proper orientation of Actin-rich structures in the larval cuticle. We further find that proper polarity in the late embryo also involves the asymmetric distribution and phosphorylation of Armadillo (Arm or β-catenin) at the membrane and that interference with this Arm phosphorylation leads to polarity defects. Our results suggest new roles for Hh and Wg as instructive polarizing cues that help establish directionality within a cell sheet, and a new polarity-signaling role for the membrane fraction of the oncoprotein Arm.
Application of high-throughput screening to identify a novel αIIb-specific small- molecule inhibitor of αIIbβ3-mediated platelet interaction with fibrinogen

Small-molecule αIIbβ3 antagonists competitively block ligand binding by spanning between the D224 in αIIb and the MIDAS metal ion in β3. They variably induce conformational changes in the receptor, which may have undesirable consequences. To identify αIIbβ3 antagonists with novel structures, we tested 33 264 small molecules for their ability to inhibit the adhesion of washed platelets to immobilized fibrinogen at 16 μM. A total of 102 compounds demonstrated 50% or more inhibition, and one of these (compound 1, 265 g/mol) inhibited ADP-induced platelet aggregation (IC50: 13± 5 μM), the binding of soluble fibrinogen to platelets induced by mAb AP5, and the binding of soluble fibrinogen and a cyclic RGD peptide to purified αIIbβ3. Compound 1 did not affect the function of GPIb, α2β1, or the other β3 family receptor αVβ3. Molecular docking simulations suggest that compound 1 interacts with αIIb but not β3. Compound 1 induced partial exposure of an αIIb ligand-induced binding site (LIBS), but did not induce exposure of 2 β3 LIBS. Transient exposure of purified αIIbβ3 to eptifibatide, but not compound 1, enhanced fibrinogen binding (“priming”). Compound 1 provides a prototype for small molecule selective inhibition of αIIbβ3, without receptor priming, via targeting αIIb.
Low loss conductors for CMOS and through glass/silicon via (TGV/TSV) structures using eddy current cancelling superlattice structure

Superlattice structures consisting of non-ferromagnetic/ferromagnetic metals have been used to create high performance conductors for radio frequency (RF) transmission lines and low loss vias in CMOS and through silicon/glass via (TSV/TGV) structures, whose ohmic resistance and RC delays have been greatly reduced. Two permalloys of Ni 80 Fe 20 and FeCo are studied as the ferromagnetic materials with low and high magnetization saturation that can be used for designing superlattice structures with low and high GHz frequency ranges, respectively. The effects of design parameters including the number of layers and thickness ratio of the superlattice structures have been studied. Full wave simulations have been used to verify them. Finally, a radial superlattice structure consisting of Cu/NiFe layers has been implemented and its resistance has been compared with the control solid-core devices made of copper; proving the effectiveness of the proposed radial superlattice structure for reducing the RF loss.
The democratic elite: America's movie stars

This study presents a collective portrait of movie stars, an American artistic elite. It examines the social backgrounds and recruitment patterns of top movie stars in the United States from 1932 to 1984.
Identifying image structures for content-based retrieval of digitized spine x rays

We present ongoing work for the computer-assisted indexing of biomedical images at the Lister Hill National Center for Biomedical Communications, a research and development division of the National Library of Medicine (NLM). For any class of biomedical images, a problem confronting the researcher in image indexing is developing robust algorithms for localizing and identifying anatomy relevant for that image class and relevant to the indexing goals. This problem is particularly acute in the case of digitized spine x-rays, due to the projective nature of the data, which results in overlapping boundaries with possibly ambiguous interpretations; the highly irregular shapes of the vertebral bodies, sometimes additionally distorted by pathology; and possible occlusions of the vertebral anatomy due to subject positioning. We present algorithms that we have developed for the localization and identification of vertebral structure and show how these algorithms fit into the family of algorithms that we continue to develop for our general indexing problem. We also review the indexing goals for this particular collection of digitized spine x-rays and discuss the use of the indexed images in a content-based image retrieval system.
Parallel processing of signals in neural sets as manifested in the EEG

Summary An approach suggested by von Neumann (1958) to understanding brain function emphasizes (a) that operations on neural information are in both analog and digital modes; (b) that neural information is carried in statistical regularities over pulse trains on groups of axons rather than in pulse intervals of single axons; (c) that processing is predominantly in parallel rather than in series; and (d) that the “language” of the brain is not “absolutely relevant” to our mathematics. An experimental basis for realizing this approach is constructed from measurements on the electroencephalographic (EEG) waves, evoked potentials, and unit activity of the olfactory system of cats and rabbits. Dynamic models are constructed from nonlinear differential equations, and the solutions are fitted to the electrophysiological data in testing the models. A hypothesis is presented on the neural sensory coding of odors in a parallel processing mode. The basis for the models is the concept that locally dense interactions among large numbers of neurons in masses give rise to active states, which are continuous in time and in the spatial dimensions of the neural masses. The interactions are described topologically as occurring within and between interactive sets of neurons. The strengths of interactions are represented by feedback gain coefficients in linearized dynamic equations. The gains are treated as the principle variable parameters in relation to behavior. When the gains are sufficiently high, instabilities arise that may take the form of limit cycle activity. A form of limit cycle activity is postulated to occur at a crucial step in sensory coding.
Chemie des Schwefeltetrafluorids

In dieser Arbeit wird ein Uberblick uber die chemischen und physikalischen Eigenschaften des Schwefeltetrafluorids gegeben. Die Struktur der Verbindung wird diskutiert und die toxikologischen Eigenschaften werden mitgeteilt. Besonders eingehend werden die Reaktionen des SF4 als Fluorierungsmittel behandelt.
Teacher Education Reform: Implications for Minorities

(1991). Teacher Education Reform: Implications for Minorities. Journal of Early Childhood Teacher Education: Vol. 12, No. 2, pp. 11-15.