cssi/SciSciGPT-SciSciNet huggingface dataset:
The comparative effectiveness of systematic desensitization and implosive therapy in the treatment of snake phobia.

Abstract Systematic desensitization (SD) and implosive therapy (IT) were compared for their effectiveness in modifying snake phobic behavior. SD differed significantly from IT and all control procedures at posttreatment, showing the greatest decrease in snake phobic behavior. IT did not differ from any of the control procedures. One-month follow-up indicated that SD continued to exhibit the greatest decrease in phobic behavior. IT continued to show the least amount of change. The results support a counterconditioning view of SD and indicate that further research must be conducted before any conclusions can be made concerning IT's efficacy.
Costly Signaling and the Origin of Religion

Costly signaling theories of religion contend that religious belief and behaviors function as costly signals of cooperative intent. Such signals are evolvable because they allow likely cooperators to find one another, while excluding potential cheats or free riders that would be unwilling (or unable) to pay the price associated with sending the signal. As a result, under the right conditions, religious costly signaling can emerge as an evolutionary stable strategy. However, reliability certifying costly signaling can evolve and stabilize only when certain necessary conditions are satisfied. In this paper we argue that current versions of the theory do not adequately demonstrate that these conditions are met.
Comparison between spontaneous gonadotropin concentration profiles and gonadotropin response to low-dose gonadotropin-releasing hormone in prepubertal and early pubertal boys and patients with hypogonadotropic hypogonadism: assessment by using ultrasensitive, time-resolved immunofluorometric assay.

ABSTRACT: To assess whether nocturnal gonadotropin concentration profiles in children could be predicted by measurement of peak gonadotropin levels after gonadotro-pin-releasing hormone (GnRH) administration, we measured spontaneous gonadotropin levels every 20 min and the gonadotropin responses to tow-dose GnRH using an ultrasensitive, time-resolved immunofluorometric assay in 61 boys with short stature and/or delayed puberty. Spontaneous nocturnal LH pulses were observed in 58 out of 61 patients. After GnRH administration in a dose of 25 ng/ kg, all of the 61 patients had significant LH and FSH responses, and GnRH-stimulated peak LH and FSH levels were highly correlated with maximal spontaneous nocturnal LH and FSH levels, respectively (r = 0.83 for LH and r = 0.91 for FSH; p < 0.00001). Analysis of individual subjects revealed that GnRH-stimulated peak LH levels were almost identical to maximal nocturnal LH levels in the subjects whose GnRH-stimulated peak LH levels were between 5 and 10 IU/L, whereas GnRH-stimulated peak LH levels tended to be higher than maximal nocturnal levels in the subjects whose GnRH-stimulated peak LH levels were 5 IU/L or lower. To determine if there were any parameters in the gonadotropin response to GnRH that might be useful in distinguishing early pubertal boys from prepvbertal boys, we evaluated the gonadotropin response to GnRH in 44 prepubertal and 10 early pubertal normal short boys. Although maximal nocturnal LH levels did not overlap between prepubertal and pubertal groups, GnRH-stimulated LH peak levels overlapped considerably between the two groups. Even the GnRH-stimulated peak LH to peak FSH ratio overlapped between the two groans. In conclusion, although the use of an ultrasensitive assay enabled as to detect goaadotropin response to GnRH stimulation in a dose of 25 ng/kg in all of the subjects, it was difficult to predict the precise changes in spontaneous circulating gonadotropin concentrations around the onset of puberty simply by measurement of gonadotropin peak levels after GnRH administration.
Quantitative comparison and evaluation of software packages for assessment of abdominal adipose tissue distribution by magnetic resonance imaging

To examine five available software packages for the assessment of abdominal adipose tissue with magnetic resonance imaging, compare their features and assess the reliability of measurement results. Feature evaluation and test–retest reliability of softwares (NIHImage, SliceOmatic, Analyze, HippoFat and EasyVision) used in manual, semi-automated or automated segmentation of abdominal adipose tissue. A random sample of 15 obese adults with type 2 diabetes. Axial T1-weighted spin echo images centered at vertebral bodies of L2–L3 were acquired at 1.5 T. Five software packages were evaluated (NIHImage, SliceOmatic, Analyze, HippoFat and EasyVision), comparing manual, semi-automated and automated segmentation approaches. Images were segmented into cross-sectional area (CSA), and the areas of visceral (VAT) and subcutaneous adipose tissue (SAT). Ease of learning and use and the design of the graphical user interface (GUI) were rated. Intra-observer accuracy and agreement between the software packages were calculated using intra-class correlation. Intra-class correlation coefficient was used to obtain test–retest reliability. Three of the five evaluated programs offered a semi-automated technique to segment the images based on histogram values or a user-defined threshold. One software package allowed manual delineation only. One fully automated program demonstrated the drawbacks of uncritical automated processing. The semi-automated approaches reduced variability and measurement error, and improved reproducibility. There was no significant difference in the intra-observer agreement in SAT and CSA. The VAT measurements showed significantly lower test–retest reliability. There were some differences between the software packages in qualitative aspects, such as user friendliness. Four out of five packages provided essentially the same results with respect to the inter- and intra-rater reproducibility. Our results using SliceOmatic, Analyze or NIHImage were comparable and could be used interchangeably. Newly developed fully automated approaches should be compared to one of the examined software packages.
Optimal order multilevel preconditioners for regularized ill-posed problems

In this article we design and analyze multilevel preconditioners for linear systems arising from regularized inverse problems. Using a scale-independent distance function that measures spectral equivalence of operators, it is shown that these preconditioners approximate the inverse of the operator to optimal order with respect to the spatial discretization parameter h. As a consequence, the number of preconditioned conjugate gradient iterations needed for solving the system will decrease when increasing the number of levels, with the possibility of performing only one fine-level residual computation if h is small enough. The results are based on the previously known two-level preconditioners of Rieder (1997) (see also Hanke and Vogel (1999)), and on applying Newton-like methods to the operator equation X -1 - A = 0. We require that the associated forward problem has certain smoothing properties; however, only natural stability and approximation properties are assumed for the discrete operators. The algorithm is applied to a reverse-time parabolic equation, that is, the problem of finding the initial value leading to a given final state. We also present some results on constructing restriction operators with preassigned approximating properties that are of independent interest.
Enhanced preservation of acutely ischemic myocardium with transseptal left ventricular assist

Abstract Mechanical support for acute regional ischemia without hemodynamic collapse may be achieved percutaneously with an intraaortic balloon pump (IABP) or with transseptal left ventricular assist (TLVA) while awaiting revascularization. The relative benefits of these two percutaneous transfemoral techniques for the treatment of ischemia were compared in a representative animal model. During 90 minutes of regional coronary occlusion, four groups of 8 pigs were treated with either no support (control), IABP, TLVA, or both IABP and TLVA. Cardioplegic arrest for 30 minutes to simulate coronary grafting was followed by 180 minutes of global reperfusion on bypass. In all groups regional wall motion and interstitial pH in the area at risk were significantly depressed with ischemia, but wall motion fully recovered after reperfusion. However, histochemical staining of the area of necrosis/area at risk was significantly reduced with IABP versus control (20.2% versus 34.1%; p p
Trends and random walks in macroeconmic time series: Some evidence and implications

Abstract This paper investigates whether macroeconomic time series are better characterized as stationary fluctuations around a deterministic trend or as non-stationary processes that have no tendency to return to a deterministic path. Using long historical time series for the U.S. we are unable to reject the hypothesis that these series are non-stationary stochastic processes with no tendency to return to a trend line. Based on these findings and an unobserved components model for output that decomposes fluctuations into a secular or growth component and a cyclical component we infer that shocks to the former, which we associate with real disturbances, contribute substantially to the variation in observed output. We conclude that macroeconomic models that focus on monetary disturbances as a source of purely transitory fluctuations may never be successful in explaining a large fraction of output variation and that stochastic variation due to real factors is an essential element of any model of macroeconomic fluctuations.
Semi-interpenetrating polymer networks composed of poly(ethylene terephthalate) and vernonia oil

Semi-interpenetrating networks have been synthesized from vernonia oil-sebacic acid polyester network and poly(ethylene terephthalate) (PET). Bond interchange reactions during mixing of the two materials led to the formation of a miscible copolymer mixture, in which the vernonia oil was then cross-linked with sebacic acid. The materials were phase-separated, exhibiting two glass transitions, when the network was synthesized at 160°C, below the crystallization temperature of PET: however, a single stable glass transition (Tg) results after the material is heated to above the melting temperature of PET and cooled. When the vernonia polyester network was completely formed at 250°C, above the crystallization temperature of PET, noncrystalline, single-Tg material was created. The two-phase semi-IPNs were much tougher than were their constituent materials, with the 50% semi-IPN over 15 times tougher than the PET from which it was made and over 50 times tougher than the neat vernonia oil elastomer, with tensile energy to break of 1780 kJ/m3. The single-Tg material was nearly 2.5 times as tough as the two-phase material, with energy to break of 4400 kJ/m3. The microstructure of the two-phase 50% semi-IPN was investigated by transmission electron microscopy, which showed regularly shaped spherulites of 10–20 μm in diameter, as compared to irregularly shaped spherulites observed in a similar 50/50 castor oil urethane/PET semi-IPN, in which the network formed simultaneously with PET crystallization. Scanning electron microscopy of the semi-IPN fracture surfaces showed microscopic fibrils several hundred nanometers in diameter in both the two-phase and single-Tg materials, although only the two-phase semi-IPN had a macroscopically rough surface. © 1993 John Wiley & Sons, Inc.
Alternate certification in Connecticut: Reshaping the profession

(1990). Alternate certification in Connecticut: Reshaping the profession. Peabody Journal of Education: Vol. 67, The Alternative Certification of Teachers, pp. 35-54.
Influence of Geographical Area of Production on Response of Different Barley Samples to Enzyme Supplements or Water Treatment

Abstract ALTHOUGH several workers have shown that the nutritional value of barley for poultry can be improved by enzyme supplementation or water treatment, other investigators (Hamm, 1958; and Gerry, 1959) have failed to improve the nutritional value of barley by addition of enzyme supplements to the feed or water treating the grain. Hamm (1958) obtained a growth depression when barley was water treated and incorporated into diets for chicks. He also failed to obtain a response when Clarase 300 was added to diets containing barley. However, others (Dobson and Anderson, 1958; Arscott, 1958; Fry: et al, 1958; Wharton et al., 1958; and Willingham et al., 1958) have shown marked improvements in barley by additions of enzymes or by water treating the barley. In order to obtain information on factors contributing to this apparent discrepancy, samples of barley grown in eleven different areas of the United States and Canada were obtained and…
BCG vaccination in Virginia.

Summary One thousand five hundred and thirty-three infants, predominantly Negro, formed the basis for this study. Effectiveness of BCG vaccine was not conclusively demonstrated. A high degree of tuberculous infection among a group of young clinic patients was noted. Evidence is presented to show that the multiple puncture technique of BCG vaccination is a safe procedure.
Enzymatic oligomerization of vanillic acid

Abstract When vanillic acid was incubated with an extracellular laccase from the fungus Rhizoctonia praticola, the formation of various oligomeric products was observed ranging from dimers to pentamers. The three dimers isolated by thin-layer chromatography had molecular ions of 304, 304 and 334, respectively, which corresponded to two dimers (methoxy-p-benzoquinone-vanillic acid) with C-O (2-methoxy-6-(2'-methoxy-4'-carboxyphenoxy)-1,4-benzoquinone) and C-C (2-methoxy-6-(2'-hydroxy-3'-methoxy-5'-carboxyphenyl)-1,4-benzoquinone) coupling, and dehydrodivanillic acid (m/z 334) (2,2'-dihydroxy-3, 3'-dimethoxy-5,5'-dicarboxybiphenyl). The identity of these compounds and their methylated derivatives was confirmed by mass and NMR spectrometric analysis. The oxidative coupling of vanillic acid is also catalyzed by peroxidase but not by tyrosinase.
Semidiurnal Amphidrome of the North East Pacific: Where?

The degree to which satellite altimetry may extend its contributions to geophysics will depend on the accuracy of corrected altitudes, on the precision of orbit corrections, on exact geoid representation and on our ability to separate independent oceanic processes affecting sea surface elevations. The barotropic tide — namely the oceanic response to gravitational driving which maintains its phase lock with gravitational forces and which is always exactly predictable — constitutes a fundamental phenomenon in itself. Indirectly it tends to obscure in altimetric data other processes such as solid earth tides, large scale ocean circulation and climatic response of the ocean.
Indirect Laser-Induced Temperature Jump Study of the Chain-Length Dependence of the pKa's of ω-Mercaptoalkanoic Acid Monolayers Self-Assembled on Gold

The indirect laser-induced temperature-jump (ILIT) technique is used to measure the pKa's of self-assembled monolayers (SAMs on gold electrodes) composed of dibutanoic acid disulfide (DBAD) and 6-mercaptohexanoic acid (MHA) in contact with 1.00 M ionic strength NaClO4 electrolyte solutions. The ILIT technique may be used to determine the pKa of a surface-attached acid because the size of the ILIT response is related to the potential drop across the electrode/electrolyte interface that is, in turn, related to the extent of ionization of the acid. The pertinent data are the potentials of zero ILIT response (Epzr) versus pH. It is found that the measured Epzr versus pH data set for the DBAD monolayers is (within experimental error) the same as that measured for the MHA monolayers. Additionally, an analysis of the combined DBAD/MHA data set gives a pKa (4.5 ± 0.2) and a total concentration (ΓT) of either DBAD or MHA comprising the SAM (ΓT = (5.4 ± 0.3) × 10-10 mol/cm2) that (again within experimental error) a...
Improving forecasting through textbooks — A 25 year review

Abstract In celebration of the International Institute of Forecasters' 25th anniversary, this paper reviews the improvement in forecasting by looking at changes in forecasting textbooks over the last 25 years. Today, more texts are available than ever before to both introductory students and seasoned forecasters and many of these are increasingly specialized. Today's textbook authors are standing on the shoulders of the previous authors while adding original ideas and discussing innovations contained in the more recent forecasting literature. This paper reviews books that should be considered milestones within the forecasting profession. This paper also details changes in the length, presentation, organization, content and pedagogy of forecasting textbooks during the past 25 years. In addition, we review the changes due to the diffusion of forecasting literature into textbooks.
Transport and elimination of recombinant human NGF during long-term delivery to the brain.

The gene for human nerve growth factor (NGF) has been cloned into a mammalian cell line and large quantities of recombinant human NGF (rhNGF) can now be produced for clinical use, but little is known about the fate of rhNGF following delivery to the brain. In this study, we implanted polymer matrices containing 125I-labeled rhNGF into the brains of adult rats and measured spatial distributions of the released protein for 8 weeks after implantation. NGF content in the tissue was determined by counting gamma radiation in thick (1 mm) sections and by autoradiography of thin (20 microns) sections. For the first several days, the rate of NGF release from the polymer matrix was high (approximately 100 ng/day); maximal NGF concentrations, measured at the polymer-tissue interface, were correspondingly high (> 20 micrograms/ml) though day 4. At later times, the release rate decreased (2-10 ng/day) and lower maximal concentrations were observed (1-10 micrograms/ml). NGF levels were always highest in the tissue sections closest to the polymer; during the 8 weeks of the experiment, NGF levels measured in thick sections decreased 100-fold, from 30 ng/section at day 2 to 0.3 ng/section at day 54. The first 10-fold decrease occurred during the first 10 days of the study; a further 6 weeks was required to achieve the second 10-fold decrease. Throughout the experiment, the majority of NGF remained within a restricted zone around the polymer at all times; the mass of NGF decreased to 10% of the maximal level within 2-3 mm of the polymer matrix. At early times ( 20 pg of NGF was also detected in regions of the brain further removed from the polymer. Comparison of local rhNGF concentration profiles with a simple mathematical model indicated that rhNGF diffuses through the brain interstitial space and is eliminated with a half-life of approximately 45 min, although elimination appears to be substantially slower in white matter regions. This limited ability of NGF to penetrate and be retained within the brain tissue indicates that NGF will need to be delivered almost directly to the target tissue for efficacy.
Kinematical parameters of nuclear reactions

Title of program:NUCLEAR SPECTRA Catalogue number: ABOM Program obtainable from: CPC Program Library, Queen’s University of Belfast, N, Ireland (see application form in this issue) Computer for which the program is designed and others upon which it is operable Computer: CDC 6600. Installation: The University of Texas Computer Center Operating system or monitor under which the program is executed:UT-2 Programming languages used: FORTRAN High speed store required: 77 777 words. No. of bits in a word: 60 Is the program overlaid?No
Symptom Burden, Depression, and Spiritual Well-Being: A Comparison of Heart Failure and Advanced Cancer Patients

BACKGROUND A lower proportion of patients with chronic heart failure receive palliative care compared to patients with advanced cancer.
Irritant dermatitis among workers cleaning up a pesticide spill: California 1991

An outbreak of dermatitis occurred among county jail inmates who removed dead fish from the Sacramento River in California after a spill of metam sodium. The spilled chemical decomposes to methylisothiocyanate (MITC), a known skin irritant. A retrospective cohort study was conducted among the inmates and their crew leaders. Among 42 jail group members, 27 had dermatitis involving the feet and ankles; dermatitis was associated with lower extremity water contact (RR = 3.4, 95% CI 1.0-11.8); the attack rate increased with length of time spent in the water. For comparison, other state and federal employees who worked in the river at the same time were also interviewed. None reported dermatitis. Over three-quarters (24/31) of these other clean-up workers whose feet became wet changed to dry clothing immediately; none of the jail group changed immediately. The river concentration of MITC measured 20-40 ppb at the time of exposure. We speculate that prolonged wetness, occlusive boots, friction, and heat contributed to chemical irritation at this low concentration; the experience of the other clean-up workers suggests that this outbreak could have been prevented.
Inhibition of neuronal surface proteases decreases the requirement for GAP-43 in neurite outgrowth

Abstract Intracellular delivery of anti-GAP IgG inhibits the elaboration of neurites by NB2a/d1 cells. However, recent studies indicate that the extent of inhibition is minimized when cells were cultured on poly- l -lysine-coated or laminin-coated versus uncoated plates, suggesting that the role of GAP-43 in neuritogenesis may be specifically related to membrane adhesiveness. We therefore examined the influence of inhibition of thrombin, the neuronal surface protease that restricts neurite outgrowth, on GAP-43-dependent neurite outgrowth. Treatment of cells with the specific thrombin inhibitor hirudin in the presence of serum induced a similar percentage of neurite outgrowth as was observed following serum withdrawal. However, while neurite outgrowth induced by serum deprivation of cells was reduced following intracellular delivery of anti-GAP IgG, neurite outgrowth induced by hirudin treatment of cells was not. That inhibition of neuronal surface protease activity overcomes the inhibition of neurite outgrowth following intracellular delivery of anti-GAP IgG provides further evidence that the role that GAP-43 plays in neuritogenesis is related to membrane adhesiveness.
Marginal Mandibulectomy vs Segmental Mandibulectomy: Indications and Controversies

Hypothesis: When resecting a floorof-mouth (FOM) squamous cell carcinoma that abuts a nonirradiated mandible, if neither clinical examination nor preoperative studies have shown evidence of bony tumor invasion and if the periosteum is histologically positive for cancer on frozen section and the underlying bone is grossly normal, a segmental resection of the mandible is required. A marginal resection is never appropriate.
Logit and Multilevel Logit Modeling of College Graduation for 1984-1985 Freshman Student-Athletes

Abstract This article describes statistical research on the academic performance of student-athletes in college sports programs. We describe several statistical models used in the prediction of academic success defined by college persistence and graduation. Using longitudinal data on the academic performances of about 3,000 student-athletes in NCAA Division I collegiate sports programs, we formulate logit and multilevel logit statistical models for the prediction of graduation rates. These prediction models are based on academic, demographic, and athletic variables, and are used to account for differences in both the students and the colleges. These results show (1) moderate but significant relationships between precollege academic characteristics and college graduation, (2) small but significant differential validity of prediction between major student-athlete groups, (3) notable college-level variance in the average graduation rate, (4) small but significant within-college relationships between precolle...
Pathologic extracardiac uptake of Tc-99m tetrofosmin identified in the chest during myocardial perfusion imaging

Viewing projection images should be an integral part of interpreting MPI studies. This practice enables the reader to diagnose important extracardiac pathologies. Although physiologic and benign conditions may merely be an academic exercise, malignant conditions that require immediate intervention may be incidentally found. Even though MPI is performed for cardiac evaluation, cardiologists or nuclear radiologists interpreting the study should be watchful for noncardiac uptake of the radiotracer.
Cadmium telluride for low energy gamma-ray and X-ray spectrometers

Abstract Cadmium telluride detectors have been fabricated which are useable as low energy gamma and X-ray spectrometers. A threshold energy of 10 keV and a resolution of 9.8 keV (fwhm) were obtained for the 59 keV line from 241 Am. K X-ray escape peaks for Cd and Te have been observed.
Risk-taking and the adolescent hemophiliac.

To evaluate the clinical impression that hemophiliacs express a high level of interest in physical activities associated with a significant risk of major bleeding, a self-administered questionnaire was given to the 17 hemophilic adolescents 11–19 years of age in a state hemophilia program, and to 17 age-matched non-hemophilic adolescents. Scores for risk-taking attitudes, anticipated risk-taking behavior and their apparent likelihood of carrying out the behaviors were calculated for 23 activities. Compared with controls, hemophiliacs neither express greater risk-taking attitudes, anticipate greater risk-taking behavior, nor appear more likely to carry out the behavior. Hemophiliacs 15–19 years of age appear more likely to carry out the stated risk-taking behaviors when compared with younger (11–14-year-old) hemophiliacs but not when compared with matched older non-hemophiliacs. Risk-taking activites selected by hemophiliacs tend to be adaptive for the limitations imposed by their illness. The conclusion that hemophiliacs appear more likely to engage in risk-taking behavior as they get older, although they express no greater overall interest in risk-taking than do non-hemophilic adolescents, needs to be confirmed by behavioral observations as home care programs improve the activity potential of young hemophiliacs.
The ionization potential of 7Li2 and bond energy of 7Li2

Abstract Details of an OODR study of the Rydberg states of the lithium dimer are presented which were used to arrive at a value of T O (∞) = 41496 ± 4 cm −1 for the ionization potential of 7 Li 2 . Using a more recent value for the dissociation energy of the 7 Li 2 ground electronic state, a value of D e = 10464 ± 6 cm −1 is derived for the dissociation energy of the X 2≤ g + ground state of 7 Li 2 + . These results are in serious disagreement with a recent determination in which an incorrect spectral assignment is believed to have been made.
Multiple-quantum filters of spin-3/2 with pulses of arbitrary flip angle

The influence of inhomogeneous RF fields on the double- and triple-quantum filtering of spin-3/2 nuclei in the presence of biexponential relaxation is analyzed. In this analysis, spherical tensor operators have been used for density-matrix calculations. In the presence of inhomogeneous RF fields, it is shown that the three-pulse triple-quantum filter (TQF) without a refocusing 2 theta pulse (with delta omega = 0) is on average about 100% more sensitive than the corresponding double-quantum filter (DQF), and in the case of four-pulse DQF and TQF with a refocusing 2 theta pulse (with delta omega not equal to 0), two relaxation coefficients f(1)11(tau) and f(1)33(tau) also contribute to the observed DQ and TQ coherences. It is also shown that the three-pulse filters are more sensitive than the corresponding four-pulse filters. In both three- and four-pulse cases, when used with surface coils, these filters act as depth pulses and thus yield spatial localization. The experimental results obtained with homogeneous RF coils are in excellent agreement with the theoretical results.
Damage to the default mode network disrupts autobiographical memory retrieval

Functional neuroimaging studies have implicated the default mode network (DMN) in autobiographical memory (AM). Convergent evidence from a lesion approach would help clarify the role of the DMN in AM. In this study, we used a voxelwise lesion-deficit approach to test the hypothesis that regions of the DMN are necessary for AM. We also explored whether the neural correlates of semantic AM (SAM) and episodic AM (EAM) were overlapping or distinct. Using the Iowa Autobiographical Memory Questionnaire, we tested AM retrieval in 92 patients with focal, stable brain lesions. In support of our hypothesis, damage to regions within the DMN (medial prefrontal cortex, mPFC; posterior cingulate cortex, PCC; inferior parietal lobule, IPL; medial temporal lobe, MTL) was associated with AM impairments. Within areas of effective lesion coverage, the neural correlates of SAM and EAM were largely distinct, with limited areas of overlap in right IPL. Whereas SAM deficits were associated with left mPFC and MTL damage, EAM deficits were associated with right mPFC and MTL damage. These results provide novel neuropsychological evidence for the necessary role of parts of the DMN in AM. More broadly, the findings shed new light on how the DMN participates in self-referential processing.
Polarity-Coincidence-Array Based Spectrum Sensing for Multiple Antenna Cognitive Radios in the Presence of Non-Gaussian Noise

One of the main requirements of cognitive radio (CR) systems is the ability to perform spectrum sensing in a reliable manner in challenging environments that arise due to propagation channels which undergo multipath fading and non-Gaussian noise. While most existing literature on spectrum sensing has focused on impairments introduced by additive white Gaussian noise (AWGN), this assumption fails to model the behavior of certain types of noise found in practice. In this paper, the use of a non-parametric and easily implementable detection device, namely the polarity-coincidence-array (PCA) detector, is proposed for the detection of weak primary signals with a cognitive radio equipped with multiple antennas. Its performance is evaluated in the presence of heavy-tailed noise. The detector performance in terms of the probabilities of detection and false alarm is derived when the communication channels between the primary user transmitter and the multiple antennas at the cognitive radio are AWGN as well as when they undergo Rayleigh fading. From the numerical results, it is observed that a significant performance enhancement is achieved by the PCA detector compared to that of the energy detector with AWGN as well as fading channels as the heaviness of the tail of the non-Gaussian noise increases.
Improved perceptually inspired speech enhancement using a psychoacoustic model

A speech enhancement algorithm is described that uses a psychoacoustic model to estimate speech cues in the presence of low SNRs. The motivation of the proposed algorithm is to model the peripheral of human auditory system and derive a perceptually improved solution for noise suppression. In the model, a detector for speech saliency is derived to measure the degree of conspicuousness of "significant" speech signals with the presence of background noise. Three biological correlates are exploited, including a spectral saliency determining the speech cues by frequency sensitivity of human auditory system in cochlear, a phoneme saliency indicating the perception discrimination of phonemes and an audibility saliency illuminating psychoacoustic masking properties by the frequency-to-place transformation of basilar membrane. The detector generates frequency-based soft-decisions that are used in determining the presence of speech cues and controlling the parameters of speech enhancement to preserve interested components.
The Length of Stream to Sample with a Towed Electrofishing Unit When Fish Species Richness is Estimated

Abstract Meaningful estimates of fish species richness in streams for assessments of environmental quality or community-level ecological analyses can be achieved only if the length of each stream segment sampled approaches or exceeds the length at which the cumulative species number becomes asymptotic. I used data from 10 representative sites on nine southern Wisconsin warm-water streams to determine the length of stream that should be sampled when species richness is estimated with a type of towed electrofishing unit commonly used in the midwestern USA. The estimated length of stream necessary to reach an asymptotic species number varied among sites; it was not related to estimated species richness, and it was only weakly and nonsignificantly correlated (positively) with stream size, Although much shorter distances were sufficient at some sites, a stream length of 35 times the mean stream width (at normal base flow), or a length equal to three complete riffle-pool sequences, ensured that the cumulative n...
Magnified and Squared VSWR Responses for Microwave Reflection Coefficient Measurements

In conventional microwave impedance measuring the measured ratio of maximum to minimum detector signal level is ideally equal to the voltage standing-wave ratio (VSWR) of the termination. In this paper, it is shown how radically types of response are obtainable in which the observed ratio may approximately equal the square of the VSWR or may be magnified any desired amount. Theory k given enabling accurate ments by interesting techniques. Accuracies of 0.1 per cent in VSWR to 2.0 have been achieved using magnitied response techniques.
The Autism Treatment Network and Autism Intervention Research Network on Physical Health: Future Directions

* Abbreviations: AIR-P — : Autism Intervention Research Network on Physical Health ASD — : autism spectrum disorder ATN — : Autism Treatment Network CER — : comparative effectiveness research CTSAs — : Clinical Translational Science programs Autism spectrum disorders (ASDs) represent complex neurodevelopmental disorders with multiple etiologies.1 The resulting variability of behavioral, medical, and developmental concerns that affect individuals with ASDs has made it extremely difficult to predict which treatments work best for which individuals. Developing effective treatments and improving care for individuals with ASDs throughout the life span remain urgent priorities. Comprehensive coordinated care for individuals with ASDs will require further advances in our knowledge of medical and behavioral interventions and a health care system that can deliver them consistently. Over the past 7 years, the Autism Speaks Autism Treatment Network (ATN) and more recently the Autism Intervention Research Network on Physical Health (AIR-P) have significantly increased understanding of the prevalence, nature, and treatment of medical conditions in children with ASDs, such as gastrointestinal conditions, sleep disorders, metabolic disorders, and seizures. The network has pioneered in standardizing the clinical evaluation of children with ASDs, based on a comprehensive, multidisciplinary model of care. The network has also developed key partnerships that have helped the field move from limited consensus toward evidence-based autism-specific guidelines in key areas of medical concern, and has acquired the infrastructure and expertise to develop more targeted treatment studies that can help move the most effective therapies through the research pipeline and into the hands of consumers. The ATN has led in the application of quality improvement methods to autism care and in systematic efforts to bring the experience and lessons of the network to broader communities of professionals and parents. This effort, led by Autism Speaks, has allowed strong synergy among research, clinical, and family communities. Key areas of continued growth for the research activities of network include (1) on-going enhancement of research infrastructure, including increased availability of biological samples; (2) expansion of the research agenda to include more focused research … Address correspondence to James M. Perrin, MD, Department of Pediatrics, Harvard Medical School, MassGeneral Hospital for Children, 100 Cambridge St, #1542, Boston, MA 02114. E-mail: jperrin{at}partners.org
Structure, Mechanical Properties, and Thermal Transport in Microporous Silicon Nitride Via Parallel Molecular Dynamics

Molecular dynamics simulations are performed to investigate structure, mechanical properties, and thermal transport in amorphous silicon nitride under uniform dilation. As the density is lowered, we observe the formation of pores below ρ = 2.6 g/cc and at 2.0 g/cc the largest pore percolates through the entire system. Effects of porosity on elastic constants, phonons and thermal conductivity are investigated. Thermal conductivity and Young’s modulus are found to scale as ρ1–5 and ρ3–6, respectively.
The effect of Fucus vesiculosus , an edible brown seaweed, upon menstrual cycle length and hormonal status in three pre-menopausal women: a case report

Rates of estrogen-dependent cancers are among the highest in Western countries and lower in the East. These variations may be attributable to differences in dietary exposures such as higher seaweed consumption among Asian populations. The edible brown kelp, Fucus vesiculosus (bladderwrack), as well as other brown kelp species, lower plasma cholesterol levels. Since cholesterol is a precursor to sex hormone biosynthesis, kelp consumption may alter circulating sex hormone levels and menstrual cycling patterns. In particular, dietary kelp may be beneficial to women with or at high risk for estrogen-dependent diseases. To test this, bladderwrack was administered to three pre-menopausal women with abnormal menstrual cycling patterns and/or menstrual-related disease histories. Intake of bladderwrack was associated with significant increases in menstrual cycle lengths, ranging from an increase of 5.5 to 14 days. In addition, hormone measurements ascertained for one woman revealed significant anti-estrogenic and progestagenic effects following kelp administration. Mean baseline 17β-estradiol levels were reduced from 626 ± 91 to 164 ± 30 pg/ml (P = 0.04) following 700 mg/d, which decreased further to 92.5.0 ± 3.5pg/ml (P = 0.03) with the1.4 g/d dose. Mean baseline progesterone levels rose from 0.58 ± 0.14 to 8.4 ± 2.6 ng/ml with the 700 mg/d dose (P = 0.1), which increased further to 16.8 ± 0.7 ng/ml with the 1.4 g/d dose (P = 0.002). These pilot data suggest that dietary bladderwrack may prolong the length of the menstrual cycle and exert anti-estrogenic effects in pre-menopausal women. Further, these studies also suggest that seaweed may be another important dietary component apart from soy that is responsible for the reduced risk of estrogen-related cancers observed in Japanese populations. However, these studies will need to be performed in well-controlled clinical trials to confirm these preliminary findings.
Intraocular Pressure and Glaucoma

Thomas M. Aaberg, Atlanta Douglas R. Anderson, Miami Jules Baum, Boston William M. Bourrre, Rochester Ronald M. Burde, New York Fred Ederer, Bethesda Frederick T. Fraunfelder, Portland Frederick A. [akobiec, New York Michael A. Kass, St. Louis Steven G. Kramer, San Francisco Irving H. Leopold, Irvine EDITORIAL BOARD Robert Machemer, Durham A. Edward Maumenee, Baltimore Irene H. Maumenee, Baltimore Nancy M. Newman, San Francisco Don H. Nicholson, Miami Edward W. D. Norton, Miami Arnall Patz, Baltimore Deborah Pavan-Langston, Boston Allen M. Putterman, Chicago Dennis Robertson, Rochester Merlyn M. Rodrigues, Baltimore Stephen J. Ryan, Los Angeles Jerry A. Shields, Philadelphia M. Bruce Shields, Durham David Shoch, Chicago Ronald E. Smith, Los Angeles Bruce E. Spivey, San Francisco Bradley R. Straatsma, Los Angeles H. Stanley Thompson, Iowa City E. Michael Van Buskirk, Portland Gunter K. von Noorden, Houston
Expression Level of Bacillus subtilis Germinant Receptors Determines the Average Rate but Not the Heterogeneity of Spore Germination

Germination of Bacillus subtilis spores can be triggered by the binding of specific nutrients, called germinants, to germinant receptors (GRs) in the spore's inner membrane. This interaction eventually initiates, with variable time delays, the release of dipicolinic acid and cations from the spore core—a key step in spore germination. The kinetics of this process are highly heterogeneous for individual spores. In this work, we sought to investigate how the germination heterogeneity was controlled. In particular, we tested whether the rates of germination were determined by GR levels, which vary from spore to spore due to stochastic gene expression. Both the expression levels of GRs and the germination rate were measured in single spores, and the experimental results were compared to theoretical predictions. Our results indicated that the variation in the expression levels of GRs was not the primary factor that controls spore germination heterogeneity. Two alternative hypotheses are discussed in light of this experimental discovery.
The molecular perspective: alcohol.

Alcohol is a substance fraught with contradictions. It is a dangerously toxic solvent, yet it has been produced and consumed since the dawn of civilization. A glass of wine or a cocktail will complement any meal and smooth out the tensions of the day, but a few more drinks will inhibit reaction times, making the consumer the major threat currently on the road. A drink or two each day will reduce the risk for heart disease, a fact vividly shown in the unexpectedly low incidence of heart disease in the French in spite of a steady diet of rich foods. More heavy drinking, however, leads to myriad and widespread health problems, including cancer. Alcohol is detoxified in the human body in two enzymatic steps (Fig. 1). First, alcohol is oxidized to acetaldehyde by the enzyme alcohol dehydrogenase. However, acetaldehyde is even more toxic than alcohol, so it is quickly oxidized to acetate by a second enzyme, aldehyde dehydrogenase. Both of these enzymes use the cofactor nicotinamide adenine dinucleotide (NAD) to provide the oxidizing power needed for these transformations. The need for the special redox talents of NAD places an important limit on the amount of alcohol that may be detoxified. Liver cells contain a limited supply of NAD, so these enzymes can act only as fast as it is recycled. This typically limits the detoxification rate to about one drink per hour—any additional alcohol stays in the circulation until the enzymes can get around to it. Human cells build a collection of variants of these two enzymes. Six separate genes for alcohol dehydrogenase are found in the human genome, and several of these show multiple alleles. To further complicate the matter, active complexes may be formed in many cases by mixing two different types into one dimeric structure. This leads to a wide range of activities of the different forms, both in their detoxification of alcohol and their transformations of similar substrates. For instance, a particularly active form of alcohol dehydrogenase is common in people from the Pacific Rim. This might be a good thing, except that many of these individuals also carry an inactive form of aldehyde dehydrogenase, and thus they cannot metabolize the acetaldehyde that is so efficiently formed. These people are highly sensitive to alcohol, suffering from severe side effects of acetaldehyde poisoning when they drink alcoholic beverages. The strongest linkage of alcohol consumption with cancer is, quite expectedly, with cancers of the mouth, pharynx, larynx, and esophagus. The mechanisms of carcinogenesis are still a matter of study and debate, but two probable mechanisms involve the enzymes of alcohol detoxification. The acetaldehyde formed in the first step may be a major culprit. Acetaldehyde is a reactive compound that forms covalent complexes with proteins and DNA, and thus may act as a mutagen. Alcohol abuse also
On the Modern Meaning of Philanthropy

The academic study of philanthropy presupposes a comprehensive definition that guides inquiry into what, exactly, philanthropy is and why it matters. At present, though, no such well-thought-out de...
The Effect of Wind-Wave-Current Interaction on Air-Sea Momentum Fluxes and Ocean Response in Tropical Cyclones

Abstract In this paper, the wind–wave–current interaction mechanisms in tropical cyclones and their effect on the surface wave and ocean responses are investigated through a set of numerical experiments. The key element of the authors’ modeling approach is the air–sea interface model, which consists of a wave boundary layer model and an air–sea momentum flux budget model. The results show that the time and spatial variations in the surface wave field, as well as the wave–current interaction, significantly reduce momentum flux into the currents in the right rear quadrant of the hurricane. The reduction of the momentum flux into the ocean consequently reduces the magnitude of the subsurface current and sea surface temperature cooling to the right of the hurricane track and the rate of upwelling/downwelling in the thermocline. During wind–wave–current interaction, the momentum flux into the ocean is mainly affected by reducing the wind speed relative to currents, whereas the wave field is mostly affected by ...
Computing Homomorphisms Between HolonomicD-modules

Let K?C be a subfield of the complex numbers, and let D be the ring of K -linear differential operators on R=Kx1, . . . , xn. If M and N are holonomic left D -modules we present an algorithm that computes explicit generators for the finite dimensional vector spaceHomD(M, N). This enables us to answer algorithmically whether two given holonomic modules are isomorphic. More generally, our algorithm can be used to get explicit generators forExtDi(M, N) for any i in the sense of Yoneda.
A 0.5 V bulk-input OTA with improved common-mode feedback for low-frequency filtering applications

This paper presents the design of a two-stage pseudo-differential operational transconductance amplifier (OTA) and its application in low-frequency continuous time filters. The OTA was designed in a 0.18 μm, 0.45 V V T CMOS process. An improved bulk-mode common-mode feedback (CMFB) circuit has been designed which does not load the OTA compared to prior art. A self cascode load structure and partial positive feedback provide higher gain. The bulk terminals of all transistors have been biased to lower their threshold voltages (VT) and maximize signal swing. The OTA operates at a supply voltage of 0.5 V and consumes only 28 μW of power. Rail-to-rail input is made possible by using the transistor's bulk terminal as the input. For a load of 20 pF the OTA has a measured DC gain of 63 dB and a gain-bandwidth product of 570 kHz. To demonstrate the use of the OTA in practical circuits, three active RC filters were designed: a 10 kHz Butterworth filter, a 10 kHz Bessel filter, and a 2.5 kHz Tschebycheff filter.