cssi/SciSciGPT-SciSciNet huggingface dataset:
Atomic force microscopy and modeling of fatigue crack initiation in metals

Abstract We have obtained the first atomic force microscope (AFM) images of cell like boundaries and slip band emergence of fatigued metals surfaces (titanium and high strength-low alloy steel). The AFM has been used to obtain quantitative information about slip spacings and slip height displacements. Using these measurements we have determined the fraction of plastic strain that contributes to surface displacement upset. Values of 1.6% for Ti and 0.9% for HSLA resulted for completely reversed plastic strain cycling. We introduce a model for fatigue crack initiation based on slip band spacings, slip height displacement, and cumulative plastic strain. To first order these compare well with experimental initiation data obtained by other investigators. The relative ease of sample preparation for AFM, along with its outstanding height resolution, offers a higher degree of simplicity and precision in fatigue crack initiation studies compared to more conventional techniques.
Media Use of the Freedom of Information Act.

“Be liberal, be liberal, be not too damn liberal.” This Walt Whitman quote, once used on the Masthead of Newsday, suggests the difference between freedom and license and reflects the ethical duality of all human endeavor. The news media is a traditional institution in our society and is subject to all the pluses and minuses of the other of our democratic institutions. The fundamental issues and the controverted practices resulting from implementation of the Freedom of Information Act have been treated extensively in other places, by other writers, for other purposes. It is the aim of this article simply to convey a sense of how one institution, the news media, uses one law, the Freedom of Information Act. The article makes no attempt to be judgmental in the descriptions of how individual journalists use the Act and the extent to which they are supported by various organizations in such use. While it is clear that journalists are not the principal users of the F.O.I.A., it is equally clear that they have obtained information through explicit and implicit F.O.I.A. use, and have used this information in news stories. It is also true that some F.O.I.A. obtained information is provided to the news media by third parties and that such information has appeared in news stories although mention of the F.O.I.A. has not been included. Journalism practices regarding use of the F.O.I.A. run from the non-users, through periodic users, to extreme users. These practices continue to reflect differing.views on newsgathering methods, through people or documents, or both, and the debate over the sufficiency of the First and Fourteenth Amendments which, for some journalists, make necessary envoking Freedom of Information legislation, essentially moot.
Determining the Conformations of Porphyrin Dimers and Dinucleotide-Substituted DNA Constructs by 2-Dimensional Fluorescence Spectroscopy

Exciton-coupled dimers exhibit spectroscopic properties that are very sensitive to dimer conformation, making them useful probes of local structure when incorporated into systems of biological interest. Numerous spectroscopic techniques can be used to study such dimers, including linear absorption spectroscopy and circular dichroism. 2-Dimensional Fluorescence Spectroscopy (2D FS) is a technique that involves exciting a sample with a series of four ultrafast laser pulses and measuring fluorescence as a function of the time delays between pulses, yielding spectra that sensitively reflect the conformations of exciton-coupled dimers. I will describe studies in which 2D FS was combined with linear absorption spectroscopy to “solve the structure” of a dimer of zinc tetraphenylporphyrin embedded in a phospholipid bilayer membrane. It was found that the dimer adopts a mixture of folded and extended conformations in the membrane and that higher temperatures favor the folded conformation. A thermodynamic analysis revealed that this temperature-dependent conformational shift is driven by the increase in entropy of the lipid side chains upon folding of the porphyrin dimer, analogous to the hydrophobic effect that drives the folding of many proteins. I will also describe experiments in which 2D FS was used to study nucleic acid constructs substituted with two adjacent fluorescent base analogues. In a similar manner to the porphyrins, the exciton coupling between base analogues allows 2D FS signals to be combined with other spectroscopic signals to determine the local conformation of the nucleic acid. Ongoing experiments aim to use this technique to study the local structure and “real-time” dynamics of the nucleic acid components of DNA-protein complexes in solution.
Willingness to pay for ozone control: Inferences from the demand for medical care

Abstract The paper applies a discrete choice version of the household production approach to the valuation of nonmarket goods. Willingness to pay for tropospheric ozone control is estimated using medical care demand under assumptions of input necessity and weak complementarity. In example calculations, individuals living in high ozone areas are willing to pay over $170 annually for an environment in which ozone concentrations never exceed 12 pphm. Willingness to pay figures are two to four times larger than medical expense savings caused by the same ozone reductions. Estimates obtained are compared with results of previous studies, and proposed ozone control measures are discussed.
Elemental composition of the colloidal phase isolated by cross-flow filtration from coastal seawater samples

Abstract The colloidal fraction was isolated to a solid using cross-flow filtration from 165 1 of Massachusetts coastal seawater taken as part of the WHOI Intercomparison exercise in August 1994. The elemental composition of this sample was determined by ICP-MS. Comparisons to analyses made part way through the isolation process as part of the colloid intercomparison exercise, indicate that loss due to break-through and/or adsorption occurred primarily when the 1-kD Millipore membranes were used to concentrate the colloidal fraction. Retention of the colloidal material was relatively high when the Desalinization membranes were used to concentrate the colloidal material. Overall loss for the complete isolation of the colloidal phase to a solid is estimated to be ~ 90%. Despite, this high degree of loss, it is still possible to measure a large suite of elements using ICP-MS because of the removal of interfering sea salts. Elemental concentrations in the colloidal isolate are generally similar to those found previously in isolates from coastal waters off southern California except for elements such as U, I, Mo, and As which are greatly enriched, possibly due to the longer processing time of the WHOI sample or higher organic content of the colloidal material. Elements presumed to exist as neutral or positively charged hydroxy species and those known to be complexed with organic ligands have the highest relative concentrations when compared to seawater values in the colloidal phase. Reducible elements which are normally present largely as oxyanions, such as Mo, As, V, W, U and I, have high colloidal concentrations but small enrichments. These elements are enriched in the WHOI sample compared to SIO samples. When normalized to average shale, rare-earth elements (REE) in the colloidal material exhibit a pattern similar to that of Buzzards Bay seawater with a flat light REE (LREE) pattern and an enrichment in heavy REE (HREE). When normalized to this seawater, there is an enrichment in the HREE and a negative Gd anomaly characteristic of uptake on organic material.
In Vitro and in Vivo Comparison of Single‐Donor Platelets and Multiple‐Donor Pooled Platelets Transfusions in Leukemic Patients

In vitro and in vivo studies were done to evaluate efficacy of fresh, single donor platelets (SDP) obtained by Latham-bowl plateletpheresis and multiple donor, pooled platelets (MDPP) obtained by conventional centrifugation for transfusion of leukemic patients. Results indicate increased effectiveness, both in vitro and in vivo, of single donor platelets as compared to multiple donor pooled platelets.
Effects of dissipation on a superconducting single electron transistor.

We measure the effect of dissipation on the minimum zero-bias conductance, G{sup min}{sub 0} , of a superconducting single electron transistor (sSET) capacitively coupled to a two-dimensional electron gas (2DEG) in a GaAs/AlGaAs heterostructure. Depleting the 2DEG with a back gate voltage decreases the dissipation experienced by the sSET in situ. We find that G{sup min}{sub 0} increases as the dissipation is increased or the temperature is reduced; the functional forms of these dependences are compared with the model of Wilhelm etal.in which the leads coupled to the sSET are represented by lossy transmission lines.
Uncovering pH-Dependent Transient States of Proteins with Buried Ionizable Residues

The role of pH in regulating biological activity is ubiquitous, and understanding pH-mediated activity has traditionally relied on analyzing static biomolecular structures of highly populated ground states solved near physiological pH. However, recent advances have shown the increasing importance of transiently populated states, the characterization of which is extremely challenging but made plausible with the development of techniques such as relaxation dispersion NMR spectroscopy. To unlock the pH dependence of these transient states with atomistic-level details, we applied the recently developed explicit solvent constant pH molecular dynamics (CPHMDMSλD) framework to a series of staphylococcal nuclease (SNase) mutants with buried ionizable residues and probed their dynamics in different pH environments. Among our key findings is the existence of open states in all SNase mutants containing “buried” residues with highly shifted pKa’s, where local solvation around the protonation site was observed. The ca...
Erp Implementation Failure: A Case Study

Abstract While it is true that successful implementation of an enterprise resource planning (ERP) system is a task of Herculean proportions, it is not impossible. If your organization is to reap the benefits of ERP, it must first develop a plan for success. But “prepare to see your organization reengineered, your staff disrupted, and your productivity drop before the payoff is realized.” Implementing ERP must be viewed and undertaken as a new business endeavor and a team mission, not just a software installation. Companies must involve all employees, and unconditionally and completely sell them on the concept of ERP for it to be a success. A successful implementation means involving, supervising, recognizing, and retaining those who have worked or will work closely with the system. Without a team attitude and total backing by everyone involved, an ERP implementation will end in less than an ideal situation. This was the situation for a soft drink bottler that tried to cut corners and did not recognize the...
Haemodynamic consequences of recurrent insulin-induced hypoglycaemia

Summary Recurring insulin-induced hypoglycaemia (RIIH) often occurs during the therapeutic management of insulin-dependent diabetes mellitus. Controversy currently exists in the literature as to the ability of insulin and/or hypoglycaemia to promote hypertension. Could insulin and/or hypoglycaemia promote adverse pressor effects? If so, under what conditions and through what mechanism? Thus, the present study was performed to evaluate the hypothesis that RIIH produces hypertension via induction of heme oxygenase (HO)-1, promoting a significant increase in endogenous carbon monoxide (CO). Male Sprague-Dawley rats were treated for 2 weeks with varying doses of insulin (1, 3, 5, 7 and 9 U/kg, s.c.) or vehicle and fed normal rat chow or a zinc diet (1 mmol/L) for 2 weeks. Tail-cuff blood pressure, food intake and blood glucose states were monitored daily. A dose-dependent decrease in blood glucose was observed in insulin-treated rats. Blood pressure was significantly elevated in rats treated with 9 and 7 U/kg insulin compared with those treated with other doses of insulin. However, there was no change in urine output among the groups. Feeding of a high-zinc diet to rats treated with 7 U/kg insulin and treatment with the HO-1 inhibitor zinc deuteroporphyrin 2,4-bis glycol (ZnDPBG; 20 mg/kg) after insulin injection resulted in a significant reduction in blood pressure compared with 7 U/kg insulin injection alone. In addition, HO-1 protein levels in the heart and kidney and endogenous CO levels were reduced in 7 U/kg insulin-treated rats fed the high-zinc diet compared with those treated with the same dose of insulin alone. The results of the present study demonstrate that RIIH promotes hypertension and that restoration of normal CO levels with a high-zinc diet and ZnDPBG reduces blood pressure.
Streaking and Wigner time delays in photoemission from atoms and surfaces

Streaked photoemission metrology allows the observation of an apparent relative time delay between the detection of photoelectrons from different initial electronic states. This relative delay is obtained by recording the photoelectron yield as a function of the delay between an ionizing ultrashort extended ultraviolet pulse and a streaking infrared (IR) pulse. Theoretically, photoemission delays can be defined based on (i) the phase shift the photoelectron wave function accumulates during the release and propagation of the photoelectron (``Wigner delay'') and, alternatively, (ii) the streaking trace in the calculated photoemission spectrum (``streaking delay''). We investigate the relation between Wigner and streaking delays in the photoemission from atomic and solid-surface targets. For solid targets and assuming a vanishing IR skin depth, both Wigner and streaking delays can be interpreted as an average propagation time needed by photoelectrons to reach the surface, while the two delays differ for nonvanishing skin depths. For atomic targets, the difference between Wigner and streaking delays depends on the range of the ionic potential.
POVERTY, POLITICS, AND A “CIRCLE OF PROMISE”: HOLISTIC EDUCATION POLICY IN BOSTON AND THE CHALLENGE OF INSTITUTIONAL ENTRENCHMENT

ABSTRACT:Cash-strapped municipalities throughout the United States are increasingly proposing innovative education policies linking school-based reforms with neighborhood-level interventions. Bosto...
Long-range correlated percolation

This paper is a study of the percolation problem with long-range correlations in the site or bond occupations. An extension of the Harris criterion for the relevance of the correlations is derived for the case that the correlations decay as ${x}^{\ensuremath{-}a}$ for large distances $x$.. For $ald$ the correlations are relevant if $a\ensuremath{\nu}\ensuremath{-}2l0$ (where $\ensuremath{\nu}$ is the percolation correlation-length exponent), while for $agd$ the correlations are relevant if $d\ensuremath{\nu}\ensuremath{-}2l0$.. Applying this criterion to the behavior that results when the correlations are relevant, we argue that the new behavior will have ${\ensuremath{\nu}}_{\mathrm{long}}=\frac{2}{a}$.. It is shown that the correlated bond percolation problem is equivalent to a $q$-state Potts model with quenched disorder in the limit $q\ensuremath{\rightarrow}1$.. With the use of this result, a renormalization-group study of the problem is presented, expanding in $\ensuremath{\epsilon}=6\ensuremath{-}d$ and in $\ensuremath{\delta}=4\ensuremath{-}a$.. In addition to the normal percolation fixed point, we find a new long-range fixed point. The crossover to this new fixed point follows the extended Harris criterion, and the fixed point has exponents ${\ensuremath{\nu}}_{\mathrm{long}}=\frac{2}{a}$ (as predicted) and ${\ensuremath{\eta}}_{\mathrm{long}}=\frac{1}{11}(\ensuremath{\delta}\ensuremath{-}\ensuremath{\epsilon})$. Finally, several results on the percolation properties of the Ising model at its critical point are shown to be in agreement with the predictions of this paper.
How much peritoneal dialysis does your patient need? Parameters and goals

Peritoneal dialysis adequacy is most commonly assessed by indices of small solute clearance (Kt/Vurea and creatinine clearance [Ccr], for example). Once a threshold of small solute clearance has been obtained, however, further increases in small solute clearance do not result in improved long-term outcomes of peritoneal dialysis (PD) patients. In addition to small solute clearance, there are several other factors that may affect optimal dialysis outcomes. These include, but are not limited to: volume homeostasis, infiammation, malnutrition, and mineral/bone metabolism. This article will briefiy review data regarding the relationships between these various factors and survival on PD.
The World Bank's ECB Experience.

The author presents in this case study an overview of The World Bank’s ECB work with national governments and with national-level ministries.
WE-C-214-02: Six-Sigma Tools for a ``No-Fly''Patient Safety Oriented, Quality-Checklist Driven, Paperless Multi-Center Radiation Medicine Department

Purpose: The purpose of this study was to develop six‐sigma practices towards the enhancement of patient safety in an electronic, quality checklist (QCL) driven, multi‐center, paperless radiation medicine department. Methods:A baseline QCL process map (QPM), stratified into consultation through treatment‐completion stages was incorporated into the Mosaiq Oncology‐Information‐Systems platform. A cross‐functional quality management team conducted Quality‐Function‐Deployment (QFD) and DMAIC [Define/Measure/Analyze/Improve/Control] six‐sigma exercises with a focus on patient safety. QPM procedures were ranked in order of patient‐safety risk with Failure‐Modes‐and‐Effects‐Analysis (FMEA). Quantitative metrics for a grouped set of nine highest‐risk procedures were established. These included procedural delays, associated standard deviations and Z‐scores. Custom Crystal reports to extract QCL procedural data from Mosaiq were created. Baseline performance of the QPM was established over the previous year of usage. Data driven analysis led to simplification, standardization and refinement of the QPM with standard deviation, slip‐day reduction and Z‐score enhancement goals. In addition to standard‐deviation reduction, a No‐Fly‐Policy (NFP) for patient safety was introduced at the control DMAIC phase, with a process‐map interlock imposed on treatment initiation in the event of FMEA‐identified high risk tasks being delayed or not completed. The NFP was introduced in a pilot study with specific stopping rules and the same metrics used for performance assessments. A custom root‐cause‐analysis (RCA) database was deployed to monitor patient safety events. Results: Relative to the baseline phase, average slip days and standard deviations for the risk‐enhanced QPM procedures improved by over three‐fold factors in the NFP phase. Z‐scores improved by 25%. A trend for proactive delays instead of reactive hard stops was observed with no adverse effects of the NFP. Conclusions: With complex technologies, resource‐compromised staff and pressures to hasten treatment initiation, the use of six‐sigma driven process interlocks may mitigate patient safety risks as demonstrated in this study.
Quantitative imaging in breast tomosynthesis and CT: comparison of detection and estimation task performance.

PURPOSE This work investigates a framework for modeling volumetric breast imaging to compare detection and estimation task performance and optimize quantitative breast imaging. METHODS Volumetric reconstructions of a breast phantom, which incorporated electronic, quantum, and anatomical noise with embedded spherical lesions, were simulated over a range of acquisition angles varying from 4 degrees to 204 degrees with a constant total acquisition dose of 1.5 mGy. A maximum likelihood estimator was derived in terms of the noise power spectrum, which yielded figures of merit for quantitative imaging performance in terms of accuracy and precision. These metrics were computed for estimation of lesion area, volume, and location. Estimation task performance was optimized as a function of acquisition angle and compared to the performance of a more conventional lesion detection task. RESULTS Results revealed tradeoffs between electronic, quantum, and anatomical noise. The detection of a 4 mm sphere was optimal at an acquisition angle of 84 degrees, where reconstructed images using a smaller acquisition angle exhibited increased anatomical noise and reconstructed images using a larger acquisition angle exhibited increased quantum and electronic noise. For all estimation tasks, accuracy was found to be fairly constant as a function acquisition angle indicating adequate system calibration, whereas a more significant dependence on acquisition angle was observed for precision performance. Precision for the 2D area estimation task was optimal at approximately 104 degrees, while precision of the 3D volume estimation task was optimal at larger angles (approximately 124 degrees). Precision for the localization task showed orientation dependence where localization was significantly inferior in the depth direction. Overall, precision for localization was optimal at larger angles (i.e., > 125 degrees) compared to the size estimation tasks. Results suggested that for quantitative imaging tasks, the acquisition angle should be larger than currently used in conventional breast tomosynthesis for lesion detection. CONCLUSIONS Analysis of quantitative imaging performance using Fourier-based metrics highlights the difference between estimation and detection task in volumetric breast imaging and provides a meaningful framework for optimizing the performance of breast imaging systems for quantitative imaging applications.
Laser inactivation of fasciclin I disrupts axon adhesion of grasshopper pioneer neurons

A MOLECULAR mechanism for selective axonal adhesion is a central question of neural development. Cell adhesion molecules have been identified1, but it has been difficult to ascribe functions for these proteins in vivo. Here we show that the neuronal membrane glycoprotein fasciclin I has a role in the adhesion of sister axons during the development of the grasshopper limb bud. To do this we used a new technique, chromophore-assisted laser inactivation (CALI), which causes the precisely timed thermal denaturation of specific proteins by laser light targeted through a dye-labelled antibody, without any other observable damage to living cells2. This can be achieved by relaxation of the laser-excited dye which releases heat to denature the bound protein; the rapid dissipation of heat with distance insulates unbound proteins from damage. CALI is a molecular analogue of cellular laser ablation and provides an unprecedented level of spatial and temporal resolution. Using dye-labelled antibodies that recognize fasciclin I, CALI disrupts fasciculation of the pioneer neurons without affecting their growth or guidance.
Diamond Burr Treatment of Poor Vision From Anterior Basement Membrane Dystrophy

Purpose To etermine the outcome of patients with decreased vision associated with anterior basement membrane dystrophy (ABMD) managed with diamond burr (DB) polishing. Design Retrospective nonrandomized case series. Methods A chart review of all patients with ABMD who underwent epithelial debridement and DB polishing to treat visual disturbances resulting from corneal epithelial irregularity was performed. Results Ten patients’ charts were analyzed. The mean age was 57.4 years. DB treatment was performed in 13 eyes. The average preoperative BCVA was 0.40 (20/50). At the last follow-up (mean 21.8 months) the average visual acuity of these patients was 0.88 (20/23), significantly better than pre-operative readings (P Conclusions In this study, DB polishing was shown to be an effective and safe treatment for decreased vision caused by to ABMD over an average follow-up of 21.8 months.
A review of the relationship between sociocultural factors and juvenile psychopathy

Juvenile psychopathy is becoming an increasingly important construct for clinicians and those in the judicial system alike. The importance of understanding not only the concept of juvenile psychopathy, but also the sociocultural determinants and risk factors is important for treatment and predictive purposes. A literature review of several social, demographic, and cultural factors that may contribute to the development of juvenile psychopathy was conducted. These factors are race, culture and ethnicity, gender, trauma, family, community influence, and peer influence. Limitations and directions for future research are discussed.
Measurement and analysis of small-scale convective storm rainfall variability

Abstract For large-scale catchment hydrology, the crucial importance of a good estimate of spatial rainfall variability is generally admitted. However, the assumption of uniform rainfall is still applied for small areas, whether they are studied as individual catchments or represent an elementary area in a distributed model. To investigate the validity of this assumption, an experiment was conducted in a small catchment (4.4 ha) in the semiarid USDA-ARS Walnut Gulch Experimental Watershed. Measurements were made with recording and non-recording raingages as well as vectopluviometers for a range of events during the 1990 monsoon season (July–September). Geostatistical analysis of the data indicated the presence of first-order drift with corresponding rainfall gradients ranging from 0.28 to 2.48 mm per 100 m with an average of 1.2 mm per 100 m. These gradients represent a 4–14% variation of the mean rainfall depth over a 100 m distance. Given these observations, the assumption of spatial rainfall uniformity in this and similar convective environments at the small watershed scale of 5 ha appears to be invalid.
The new agricultural research and technology transfer policy agenda

Abstract The paper draws upon a national study to analyze two issues relevant to the future effectiveness of the American agricultural technology system: (1) linkages between research and technology transfer activities; and (2) relationships between the public and private sectors. Increased commitments to basic research by the US Department of Agriculture and the state agricultural experiment stations have served to exacerbate existing strains between research and technology transfer functions and units. Both the feasibility and desirability of having USDA's Agricultural Research Service simultaneously seek to strengthen its basic research capabilities and its commitment to technology transfer have been questioned. Within the landgrant universities, multiple pressures have served to attenuate traditional ties among agricultural researchers, extension specialists, and county extension agents. Private sector activity in agricultural research and the provision of technical information has increased following the expansion in the domains of knowledge over which firms can establish property rights and the concentration of production in a smaller number of economic units. Adjustments in the activities of the public sector in response to these changes can be seen. Still, the optimal mix of public-private sector activities in both research and technology transfer has yet to be fully analyzed. Current analyses (and public policy) are excessively constrained by the “property rights” approach to technological change.
Optically reconfigurable color change in chiral nematic liquid crystals based on indolylfulgide chiral dopants

Stimuli-directed changes in the coloration of chiral nematic liquid crystal devices are in nearly all cases color-restoring upon removal of the input stimulus. This work employs photoresponsive indolylfulgide chiral dopants to generate optically reconfigurable but color-stable reflectivity when formulated with a nematic liquid crystal host to form a chiral nematic mesophase. The optically-directed color change of the chiral nematic material system to UV and blue irradiation is examined as a function of concentration and light intensity. The temporal stability of the reflection notch at arbitrary spectral positions is presented – confirming that long-lasting, optically reconfigurable color changes are obtainable in this material system. The optically reconfigurable color-stable changes in reflection color could be useful as optical filters, smart textiles, or active camouflage.
A generalization of the alias matrix

Abstract The investigation of aliases or biases is important for the interpretation of the results from factorial experiments. For two-level fractional factorials this can be facilitated through their group structure. For more general arrays the alias matrix can be used. This tool is traditionally based on the assumption that the error structure is that associated with ordinary least squares. For situations where that is not the case, we provide in this article a generalization of the alias matrix applicable under the generalized least squares assumptions. We also show that for the special case of split plot error structure, the generalized alias matrix simplifies to the ordinary alias matrix.
Chiral lagrangian for deep mine physics

Abstract The chiral lagrangian for baryon number violating nucleon decay is derived and applied to nucleon decays into strange and non-strange final states. The uncertainties in our predictions are discussed.
Effects of different levels of sensory contact upon reproductive activity of adult male and female Sarotherodon (Tilapia) mossambicus (Peters); Pisces: Cichlidae

Abstract Social control of reproduction in the cichlid fish Sarotherodon mossambicus was studied in visually isolated (low-contact) males and females; male-female, male-male, and female-female pairs in adjacent aquaria with visual contact (medium-contact), and in the same aquarium (unlimited-contact). Variables included interspawning interval (ISI), gonosomic index, and gonadal histology. Results indicated that unlimited-contact fish showed enhanced reproductive activity compared with low-contact animals. Medium-contact groups were intermediate, but with the exception of ISI, not significantly different from either low- or unlimited-contact fish. Findings were discussed within the framework of the maternal mouth-brooding system.
Delaying the initiation of progesterone supplementation results in decreased pregnancy rates after in vitro fertilization: a randomized, prospective study.

Abstract Objective: To compare IVF outcome between two protocols for luteal phase supplementation, one beginning on day 3 after oocyte retrieval and the other beginning on day 6 after retrieval. Design: Prospective, randomized study. Setting: University-based assisted reproductive technology center. Patient(s): One hundred twenty-six consecutive patients undergoing IVF between January and July 2000. Intervention(s): Patients were randomized to begin luteal phase support using vaginal progesterone beginning either on day 3 after oocyte retrieval or on day 6 after oocyte retrieval. Main Outcome Measure(s): Clinical pregnancy rates and implantation rates. Result(s): All patients randomized underwent transfer. There were no differences in age, oocytes retrieved, or embryos transferred between the two groups. Those patients receiving luteal phase support with progesterone beginning on day 6 after retrieval had a significantly lower clinical pregnancy rate per transfer compared with those beginning support on day 3 after retrieval (44.8% vs. 61.0%, respectively). This difference in pregnancy rates was greater in those patients undergoing a luteal gonadotropin releasing hormone (GnRH) agonist down-regulation protocol (47.5% vs. 71.4%, day 6 vs. day 3, respectively). Beginning support on day 6 also significantly decreased implantation rates in the GnRH agonist group (21.0% vs. 34.0%, day 6 vs. day 3, respectively). Conclusion(s): Pregnancy rates are significantly decreased by initiating luteal-phase progesterone supplementation on day 6 after oocyte retrieval during in vitro fertilization cycles.
Small RNA ArrF Regulates the Expression of sodB and feSII Genes in Azotobacter vinelandii

Azotobacter vinelandii contains a prrF-like sequence in a noncoding region of the chromosome. Like the Pseudomonas aeruginosa PrrF small RNA-encoding genes, the expression of the sequence, herein named arrF (Azotobacter regulatory RNA involving Fe), was increased 100-fold in wild-type cells in response to iron depletion. The level of ArrF was also increased to the same degree in the iron-replete fur mutant, but down back to a wild-type level when this fur mutant was complemented with the wild-type fur gene. These results, with the location of arrF gene in a noncoding region, suggest that this gene encodes an iron-responsive small RNA whose expression is negatively regulated by the Fur–Fe2+ complex. Disruption of this arrF gene upregulated the expression of iron-containing superoxide dismutase and FeSII protein, whereas fur mutation or iron depletion decreased the level of their transcript. A short region in the 5′-untranslated region of each transcript was predicted to be quite complementary to the core sequence of ArrF, assuming that ArrF represses the expression of the genes under Fur control by an antisense RNA mechanism. However, unlike the P. aeruginosa PrrF that has extensive targets in the tricarboxylic acid cycle and glyoxylate cycle, ArrF had little effect on those genes. The findings that there is a poor overlap between ArrF and PrrF targets and that the FeSII gene, which is present only in the chromosome of nitrogen-fixing bacterial species, is controlled by ArrF suggest that ArrF might have unique targets, some of which are involved in N2 fixation.
Factors affecting recurrence following resection for Crohn's disease.

The records of 187 patients with Crohn's disease who underwent resectional surgery were analyzed to evaluate the effect of several clinical and histologic features on the recurrence rate. Recurrence was defined as the need for re-resection. The data were analyzed by the life-table method. Age, sex, age at onset of disease and at time of resection, family history, presence of granuloma, and microscopic involvement at the line of resection did not affect the recurrence rate. The distribution of the disease and duration of symptoms before primary resection did influence the rate of re-resection. Patients with predominantly large bowel disease (N=56) were found to have a higher rate of re-resection (45 percent) when compared with 32 percent in patients with small bowel involvement (N=94) and with 35 percent in patients with both small and large bowel involvement (N=37) (P=0.04). a detailed review, an analysis of the literature, and a comparison with our results are made.
NEUROMUSCULAR TRANSMISSION IN A SPIDER AND THE EFFECT OF CALCIUM.

Abstract 1. 1. Investigations on the neuromuscular transmission of a spider, Eurypelma hentzi Girard, were performed for the first time. The composition of an artificial saline solution is given. The membrane of the fibers of the musculus flexor metatarsi bilobatus (MFMB) behaves as a K + -electrode. Each fiber receives three motoraxons. 2. 2. Efferent stimulation of motoraxons produces small excitatory junction potentials (EJPs) of three types, which are very similar in height and rise time, nevertheless the contraction evoked is quite different. The EJPs show summation and facilitation; no inhibition was found. 3. 3. An increase in the external Ca 2+ concentration from 2 to 12 mM/l increases the amplitude of all junction potentials significantly; above that there is a decline in the height of the EJPs. The membrane potential is not affected. 4. 4. In high Ca 2+ concentrations the EJPs usually reach the critical depolarization (30 mV) for spike discharge. Action potentials vary in amplitude; sometimes there is a positive overshoot. They make the membrane partly inactive for a closely following second action potential, but not for a junction potential. 5. 5. The contraction is always augmented in higher Ca 2+ concentrations. Both action potentials and junction potentials can elicit twitches of the muscle with single shocks, the ones produced by action potentials are always much more powerful.
Management of a tracheal bronchus in a pediatric lung transplant recipient

Successful pediatric lung transplantation requires intraoperative identification and management of unforeseen anomalies in the recipient. Effective technical improvisation combines awareness of bronchial anatomic anomalies with experience in recent modifications in airway anastomotic techniques. We report a case of successful bilateral sequential double-lung transplantation in a child with the right upper lobe bronchus arising from the trachea.
The reflective mentor: charting undergraduates' responses to computer science service learning (abstract only)

Community service courses are often where undergraduates make connections between academic content and practical computer science applications, build bridges between the university and the community, and ultimately increase access to technology in such communities. In this poster we report on our efforts-supported by a NSF Broadening Participation in Computing grant-to design, implement, and evaluate a service-learning course based on a "cascading mentoring" model linking together the faculty, administration, and undergraduates of an urban university's computer science department with area high school students. The poster presents the cascading model and through a series of post-interviews offers preliminary data charting undergraduates' experiences as both mentees and mentors.
Acute and chronic effects of oestrogen on endothelial tissue-type plasminogen activator release in postmenopausal women

The capacity of vascular endothelium to locally release tissue-type plasminogen activator (t-PA) represents an important endogenous defence mechanism against intravascular fibrin deposition and thrombosis. We determined the influence of chronic and acute oestrogen administration on endothelial t-PA release in postmenopausal women. Sixty-three healthy postmenopausal women were studied: 31 non-users (age 58 +/- 1 years) and 32 users of hormone replacement therapy, including oestrogen alone (ORT: 62 +/- 2 years; n = 15) and in combination with progesterone (HRT: 57 +/- 1 years; n = 17). Net endothelial t-PA release was determined in vivo, in response to intrabrachial infusions of bradykinin and sodium nitroprusside. To examine the acute effects of oestrogen on endothelial t-PA release, bradykinin and sodium nitroprusside dose-response curves were repeated in the presence of 17 beta-oestradiol in 20 of the 31 non-users. Net endothelial release of t-PA was ~30 % higher (P < 0.01) in women taking ORT (from 2.0 +/- 1.0 to 83.6 +/- 9.2 ng (100 ml tissue)-1 min-1) compared with those taking HRT (from 1.4 +/- 0.4 to 63.5 +/- 5.6 ng (100 ml tissue)-1 min-1) and those not taking supplementation (1.0 +/- 0.7 to 63.0 +/- 4.7 ng (100 ml tissue)-1 min-1). Intra-arterial infusion of 17 beta-oestradiol significantly potentiated bradykinin-induced t-PA release. Net endothelial release of t-PA was approximately 45 % higher (P < 0.01) after (from 1.0 +/- 0.8 to 87.4 +/- 9.9 ng (100 ml tissue)-1 min-1) versus before (1.2 +/- 0.6 to 60.8 +/- 5.6 ng (100 ml tissue)-1 min-1) acute 17 beta-oestradiol administration. Our results suggest that oestrogen has a direct modulatory effect on the capacity of the endothelium to release t-PA in healthy postmenopausal women. However, progesterone appears to oppose the favourable influence of oestrogen on endothelial fibrinolytic capacity.
Early gene expression profile of human skin to injury using high-density cDNA microarrays.

Disturbances in normal wound healing may be traced to perturbations in gene expression following injury. To decipher normal and abnormal genetic responses to cutaneous injury, baseline gene expression of uninjured skin and injured skin must be better defined. Our aim for this study was to determine the gene expression profile of human skin immediately following injury using cDNA microarrays. Samples of normal and injured skin were obtained from 5 healthy females undergoing breast reduction surgery. Specimens of the epidermis and dermis were obtained at 30 minutes and 1 hour after the initial injury. RNA was extracted, reverse transcribed into cDNA and hybridized onto high-density cDNA microarray membranes of 4,000 genes. At 30 minutes, injury resulted in a consistent increase (> 2×) in gene expression of 124 out of 4,000 genes (3%). These genes were primarily involved in transcription and signaling. None of the 4,000 genes were decreased (< 2×) at 30 minutes. At 1 hour only 46 out of the 4,000 genes were increased in expression (1.15%) but 264 out of 4,000 (6.6%) genes were decreased greater than 2 fold, indicating a silencing of many structural genes. We have identified several genes, namely, suppressor of cytokine signaling-1, rho HP1, and BB1, that are highly expressed after injury and may have an unappreciated role in regulating the initial inflammatory response. These data provide an initial high-throughput analysis of gene expression immediately following human skin injury and show the utility and future importance of high-throughput analysis in skin biology and wound repair.
Nonlinear Bayesian estimation using Gaussian sum approximations

Knowledge of the probability density function of the state conditioned on all available measurement data provides the most complete possible description of the state, and from this density any of the common types of estimates (e.g., minimum variance or maximum a posteriori) can be determined. Except in the linear Gaussian case, it is extremely difficult to determine this density function. In this paper an approximation that permits the explicit calculation of the a posteriori density from the Bayesian recursion relations is discussed and applied to the solution of the nonlinear filtering problem. In particular, it is noted that a weighted sum of Gaussian probability density functions can be used to approximate arbitrarily closely another density function. This representation provides the basis for procedure that is developed and discussed.
Efficient analog-to-residue conversion schemes

The real-time requirements of residue number system (RNS) processing are considered. In conventional real-time systems, one input conversion is performed from analog to binary using commercially available analog/digital converters. In RNS systems, however, a second conversion is required from binary to residue. The elimination of this problem is proposed through the design of high-speed direct analog-to-residue converters. These converters use the principle of binary conversion, but can achieve more throughput because of their simplicity. This technique, based on flash conversion principles, requires a converter for each modulus channel consisting of a simple programmable logic array function at the final stage. For architectures requiring a binary host machine interface, simple input conversion techniques are developed using ROMs and adders. The input binary word is partitioned to suit the ROM input size, resulting in uniform conversion delays throughout the data flow path. >
Nonmetropolitan Elderly Women: A Portrait of Economic Vulnerability:

Women are a majority of elders in America, and they face a greater risk of being poor. This article examines the poverty status of elders, paying special attention to the circumstances of elderly women in nonmetropolitan areas. The oldest women, minorities, divorced or separated women, and widows are particularly likely to be or become poor in old age in both metropolitan and nonmetropolitan areas. Nonmetropolitan women, however, report higher poverty rates and have lower incomes, placing them at greater risk offalling into poverty should unexpected events occur. By examining various levels and sources of income available to metropolitan and nonmetropolitan women the authors found that nonmetropolitan women have lower wage and salary income, receive less Social Security, and have lower total own income than do metropolitan women. It is suggested that higher poverty incidence among nonmetropolitan than among metropolitan women is linked to a legacy of poorer economic opportunities in nonmetropolitan areas ...
IMMUNITY AND TOLERANCE TO A HAPTEN (NIP) COUPLED TO AN ISOLOGOUS CARRIER (MOUSE GAMMA GLOBULIN)

A hapten, 4-hydroxy-3-iodo-5-nitrophenylacetic acid (NIP) when coupled to isologous mouse gamma globulin (MγG) elicits a hapten-specific immune response in mice if administered in Freund's complete adjuvant. This response is measurable by the capacity of the sera to bind N125IP, by detection of NIP-specific plaque-forming cells (B cells), and by in vitro secondary type antigen-driven DNA synthesis (T cells and probably B cells). The in vitro response requires both the hapten and carrier since neither by itself is capable of stimulating the spleen cells. This same antigen gives rise to hapten-specific tolerance when given in the soluble form. Mice pretreated with soluble NIP-MγG and challenged with NIP coupled to a heterologous carrier give a normal antibody response to the carrier but have barely detectable levels of antibody to NIP. Spleen cells from mice made tolerant to NIP-MγG do not respond in vitro with increased DNA synthesis. This implies that thymus-derived cells as well as bone marrow-derived cells are involved in hapten-specific tolerance.
Cell Division: Kinetochores SKAdaddle

Summary Accurate chromosome segregation during cell division requires that kinetochores couple microtubule dynamics to chromosome movement. New research reveals that the kinetochore-associated Ska1 complex hangs on to depolymerizing microtubules and brings some important friends along for the ride.
Male Student-Athletes and Violence Against Women: A Survey of Campus Judicial Affairs Offices

This article examines the relationship between collegiate athletic participation and reported violence against women at Division I institutions. The research is based on the records of 10 judicial affairs offices over a 3-year period from 1991 through 1993. The findings indicate an over-representation of male student-athletes in reports of violence against women (battering and sexual assault). In total, 20 cases of battering and 69 cases of sexual assault are examined. The findings are statistically significant (from p ≤ .05).
IS SPIZELLA TAVERNERI A SPECIES OR A SUBSPECIES

Abstract Based on distributional, ecologic, morphologic, and vocal data, Klicka et al. (1999) argued in favor of species status for the form taverneri, long regarded as a subspecies of the Brewer's Sparrow (Spizella breweri). For several reasons we disagree with their conclusion: lack of evidence for the reproductive isolation of taverneri from breweri, loss of information on the close relationship and allopatric distribution of the two taxa that would accompany their elevation to species, and violation of the principle of taxonomic balance. Until the demonstration of vocal or display differences relevant to pair formation and maintenance, taverneri and breweri are best regarded as reproductively compatible subspecies.
Leprosy as a model of immunity

ABSTRACT: Leprosy displays a spectrum of clinical manifestations, such as lepromatous and tuberculoid leprosy, and type I and II lepra reactions, which are thought to be a reflection of the host’s immunological response against Mycobacterium leprae. Therefore, differential recognition of M. leprae, as well as its degraded components, and subsequent activation of cellular immunity will be an important factor for the clinical manifestation of leprosy. Although M. leprae mainly parasitizes tissue macrophages in the dermis and the Schwann cells of peripheral nerves, the presence of M. leprae in other organs, such as the liver, may also play important roles in the further modification of seesaw-like bipolar phenotypes of leprosy. Thus, leprosy is an exciting model for investigating the role of the human immune system in host defense and susceptibility to infection.