cssi/SciSciGPT-SciSciNet huggingface dataset:
Role of commissural projections in the representation of bilateral auditory space in the barn owl's inferior colliculus.

The central nucleus of the barn owl's inferior colliculus (ICc) contains a representation of both the ipsilateral and contralateral auditory hemifields. The representation of ipsilateral space is found in the “core” of the ICc, a subdivision defined by the terminal field of nucleus laminaris, the avian analogue of the medial superior olivary nucleus. The representation of contralateral space is found in the lateral portion of the “shell” of the ICc. The shell surrounds the core and is defined by the terminal field of the nucleus angularis, one of the cochlear nuclei. The representation of ipsilateral space in the core of the ICc may be accounted for by the crossed projection from the nucleus laminaris because most of the nucleus laminaris is devoted to a representation of contralateral space. We present evidence to suggest that the representation of contralateral space is due to a commissural projection from the core of one side to the lateral shell of the opposite side. Injection of horseradish peroxidase (HRP) into the lateral portion of the ICc shell produced retrogradely labeled somata in the core of the opposite side. Injection of tritiated proline into the core produced anterograde label confined to the lateral shell, thus confirming the observations made with HRP. Thus, for example, the left ICc core, which contains predominantly a representation of the left hemifield, innervates the right lateral shell, endowing it with a representation of the left, or contralateral hemifield. The representation of contralateral space in the lateral shell is ultimately conveyed to the external nucleus of the inferior colliculus where it contributes the horizontal axis to a two-dimensional map of space.
Kinematics of many-particle processes in invariant variables: Physical regions, phase space and all that

Abstract The kinematics of processes involving N spinless particles, in terms of invariant variables, are studied by means of Gram determinants. It is proposed that the Gram determinant method may provide a convenient unified treatment for general kinematical purposes. Using this approach, we first obtain the necessary and sufficient conditions for describing the physical regions; their solutions produce a systematic, practical scheme for constructing the physical regions explicitly. Secondly, a simple way of obtaining relations between geometrical and invariant quantities is described; some such relations are exhibited. The application of the Gram-determinant method is illustrated mainly with a discussion on the Toller angle dependence of the reggeon-reggeon-particle vertex function; in particular, we find a certain form of such dependence, in the asymptotic Regge limit, that arises naturally from the internal consistency of multi-Reggeism. Finally, the phase-space factor for many-particle productions is discussed.
SCRATCHPAD/360: reflections on a language design

The key concepts of the SCRATCHPAD language are described, assessed, and illustrated by an example. The language was originally intended as an interactive problem solving language for symbolic mathematics. Nevertheless, as this paper intends to show, it can be used as a programming language as well.
Far-ultraviolet observations of BW Vulpeculae with Voyager 2

BW Vul has been the subject of numerous ground-based spectroscopic and photometric studies. However, observations in the ultraviolet have been limited. The Voyager 2 observations presented in the current study include the first observations of BW Vul shortward of 1200 A. Voyager 2 observations in the 912-1700 A region are employed to investigate the variations in the temperature, radius, and luminosity of BW Vul during a pulsation cycle. Attention is given to details regarding the observations, the light curves representing the variation of BW Vul at effective wavelengths of 1050 A and 1395 A, the UV spectra, comparisons with other stars, comparisons with models, and the amplitude-wavelength relation.
Effects of neurotoxic destruction of descending noradrenergic pathways on cannabinoid antinociception in models of acute and tonic nociception.

The effects of neurotoxic destruction of catecholaminergic projections to the spinal cord on cannabinoid antinociception were examined in models of acute and tonic nociception. High performance liquid chromatography was used to quantify monoamine levels in sham-operated and lesioned rats. Intrathecal administration of the catecholamine neurotoxin 6-hydroxydopamine (6-OHDA) induced a selective depletion of norepinephrine (by approximately 85% of control) in rat lumbar spinal cord without altering levels of dopamine or serotonin. By contrast, brain levels of monoamines did not differ in sham-operated and lesioned rats. Pain behavior was similar in sham-operated and lesioned rats receiving vehicle in models of both acute and tonic nociception. The cannabinoid agonist WIN55,212-2 (5 or 10 mg/kg, i.p.) produced antinociception in the tail-flick test in sham-operated rats. The antinociceptive effect of WIN55,212-2 was attenuated relative to control conditions in rats depleted of spinal norepinephrine. WIN55,212-2 suppressed tonic pain behavior in the formalin test in sham-operated rats during phase 2 (15-60 min post formalin) of nociceptive responding. By contrast, in lesioned rats, WIN55,212-2 suppressed pain behavior during phase 1 (0-9.9 min) and phase 2A (10-39.9 min), but not during phase 2B (40-60 min). The cannabinoid agonist suppressed formalin-evoked Fos protein expression, a marker of neuronal activity, in the lumbar dorsal horn of sham-operated rats, but no suppression was observed in lesioned rats. The number of formalin-evoked Fos-like immunoreactive (FLI) cells was greater in lamina I and II of lesioned rats relative to sham-operated rats. These data indicate that the suppressive effect of the cannabinoid on formalin-evoked Fos protein expression in the superficial dorsal horn was attenuated following destruction of descending noradrenergic pathways. Our data are consistent with the hypothesis that cannabinoids produce antinociception, in part, by modulating descending noradrenergic systems and support a differential involvement of noradrenergic projections to the spinal cord in cannabinoid modulation of acute versus tonic nociception.
Microwave spectrum, diple moment, and low-frequency vibration of bicyclo[2. 1. 1]hexan-2-one

Abstract The microwave spectrum of bicyclo[2.1.1]hexan-2-one has been analyzed, resulting in a dipole moment of 3.35 ± 0.02 D and components along the principle axes of μ a = 3.32 ± 0.02 D and μ b = 0.40 ± 0.02 D . This dipole moment is much larger than that for other ketones, with the exception of cyclopentanone for which a value of 3.25 ± 0.02 D was reported. Rotational constants were determined for the ground state and the first three excited states of the lowest frequency vibrational mode. The variation of I a + I b − I c with vibrational quantum number indicates that the lowest frequency mode is predominately motion perpendicular to the plane of symmetry. The potential-energy function for this motion is close to harmonic and it has no barrier at the symmetry position, as indicated by the smooth and almost linear variation of the rotational constants with the vibrational quantum number. Relative intensity measurements for the first four vibrational states suggest that the potential is slightly steeper than harmonic with a v = 0 to 1 separation of 144 ± 15 cm −1 . The experimental moments of inertia are consistent with a structure having carbon and hydrogen positions very similar to those of the parent hydrocarbon and having reasonable carbonyl group parameters.
INTERACTING CATALYST PELLETS IN A TUBULAR REACTOR STEADY-STATE MULTIPLICITY IN SIMPLIFIED MODELS

Presented here are the results of a theoretical study aimed at investigating the effects of interactions between individual catalyst particles in a fixed-bed reactor. For tractability of the mathematical description and of the results, the model is based on a simplified picture in which spherical catalyst pellets are aligned in a single column along the axis of a tubular reactor. Further, the model is based on a first-order exothermic reaction and a mixing-cell description of the fluid flow. Numerical solutions are presented for cases of two and four active pellets Among the results are complex bifurcation diagrams and large steady-state multiplicities attributable to the discrete particle model. These features are strongly dependent on parameter values—most importantly on the distribution of catalytic activities when there are slight variations from a mean activity level. The results, though based on an idealized study model of the catalyst arrangement, apply conceptually to more realistic situations, an...
Processing and properties of some II–IV–V 2 amorphous and crystalline semiconductors

Experimental investigations on the preparation, characterization, and properties of several bulk and thin-film ternary alloys based on the chalcopyrite II–IV–V2 semiconductors are presented. Rapid melt solidification in vacuum-sealed fused-silica tubes resulted in amorphous alloy formation in almost all compositions in the system CdGeAs2-CdSiAs2. ZnGeAs2-CdGeAs2 alloys showed very limited tendency toward amorphous phase formation. Phase separation, crystallization and electrical properties were studied for amorphous Cd-Ge-Si-As alloys by thermal analysis, transmission electron microscopy, X-ray diffraction, and Hall measurements. Rapid crystallization resulted in a reversal of conductivity type (p-to-n or vice versa). Crystallized glassy alloys showed room-temperature mobility of 64 cm2/V s, and a hole concentration of 1020 cm−3. The p-to-n change in conductivity type upon amorphous-to-crystal transformation suggests that these alloys can be used to fabricate p-n junction devices by surface crystallization of the amorphous phase.
Synthesis of internal re-initiation fragments of beta-galactosidase in vitro and in vivo.

Internal re-initiation polypeptides which are products of the lacZ gene of Escherichia coli have been synthesized in a DNA-directed cell-free protein synthesis system. Some of the properties of these protein fragments have been characterized. The de novo synthesized re-initiation proteins, unlike both in vitro synthesized wild-type β-galactosidase and nonsense termination fragments, are insoluble when synthesized at 37 °C, but soluble if synthesis takes place at 25 °C. The same re-initiation proteins which are made in vivo have been detected in vitro. Unlike their in vivo counterparts, which are degraded rapidly, the in vitro synthesized restart proteins are completely stable for at least one hour following their synthesis. Both in vivo and in vitro, the re-initiation proteins are not synthesized from DNA containing a wild-type Z gene, but require a specific nonsense mutation in order to be expressed. Furthermore, the location of the mutation within the Z gene is very important in determining whether or not re-initiation will occur at a given site. Several nonsense mutations which do not result in the synthesis of detectable amounts of restart protein in vivo produce specific re-initiation polypeptides in vitro. These restart proteins display many of the same properties as do those which are made both in vivo and in vitro: they are not made from wild-type DNA, and they are only made from DNA containing a specific nonsense mutation. One of these mutations is 118, which is an extreme polar mutation in vivo. Another is 545, which synthesizes a restart protein in vivo if, and only if, it is coupled with a secondary mutation, π(1). π(1) thus appears to be necessary for the synthesis of a particular re-initiation protein in vivo but unnecessary for the synthesis of the same protein in vitro. The efficiencies of re-initiation vary at the different sites, but in all cases are less than the initiation frequency at the start of the gene. The experiments thus show that when complicating factors, such as polarity and protein degradation, are eliminated, translational re-initiation can be detected at many sites in the lacZ gene.
A systematic review of body fat distribution and mortality in older people.

We conducted a systematic review investigating body fat distribution in older adults and its association with morbidity and mortality. Our search yielded 2,702 citations. Following three levels of screening, 25 studies were selected to evaluate the association between body fat distribution and comorbidity, and 17 studies were used in the mortality analysis. Most of the selected studies in our analyses used anthropometric measures, e.g., body mass index (BMI), waist circumference, and waist-hip ratio; relatively few studies used direct measures, such as body fat/lean mass, and percentage body fat. Studies reported inconsistent findings regarding the strongest predictor(s) of morbidity and mortality. However, the majority of studies suggested that BMI per se was not the most appropriate predictor of morbidity and mortality in the elderly because of its inability to discern or detect age-related body fat redistribution. In addition, studies using BMI found that the optimal BMI range for the lowest mortality in the elderly was overweight (25 kg/m 2 ≤ BMI < 30 kg/m 2 ) or mildly obese (30 kg/m 2 ≤ BMI < 35 kg/m 2 ). Our findings suggest that the current clinical guidelines, recommending that overweight and obesity are major risk factors for increased morbidity and mortality are not applicable to this population. Therefore, the central message of this review is to admonish the government to establish new guidelines specifically for this population, using a combination of body fat distribution measurements, and to certify that these guidelines will not be applied to inappropriate populations.
Altered AMP deaminase activity may extend postmortem glycolysis

Abstract Postmortem energy metabolism drives hydrogen accumulation in muscle and results in a fairly constant ultimate pH. Extended glycolysis results in adverse pork quality and may be possible with greater adenonucleotide availability postmortem. We hypothesized that slowing adenonucleotide removal by reducing AMP deaminase activity would extend glycolysis and lower the ultimate pH of muscle. Longissimus muscle samples were incorporated into an in vitro system that mimics postmortem glycolysis with or without pentostatin, an AMP deaminase inhibitor. Pentostatin lowered ultimate pH and increased lactate and glucose 6-phosphate with time. Based on these results and that AMPK γ3 R200Q mutated pigs (RN − ) produce low ultimate pH pork, we hypothesized AMP deaminase abundance and activity would be lower in RN − muscle than wild-type. RN − muscle contained lower AMP deaminase abundance and activity. These data show that altering adenonucleotide availability postmortem can extend postmortem pH decline and suggest that AMP deaminase activity may, in part, contribute to the low ultimate pH observed in RN − pork.
Closed-form mapping conditions for the synthesis of linear processor arrays

This paper addresses the problem of mapping algorithms with constant data dependences to linear processor arrays. The closed-form necessary and sufficient mapping conditions are derived to identify mappings without computational conflicts and data link collisions. These mapping conditions depend on the space-time mapping matrix and the problem size parameters only. Their correctness can be verified in constant time that is independent of problem size. The design of optimal linear processor arrays is formulated as a mathematic programming problem, which can be solved efficiently by a systematic enumeration of a polynomial search space.
Hetastarch and Bleeding Complications After Coronary Artery Surgery

Study objectives Controversy persists concerning the potential association between intraoperative use of hetastarch (ie, hydroxyethyl starch [HES]) and postoperative bleeding in patients undergoing surgery. To determine whether intraoperative HES use is associated with an increased risk of postoperative bleeding following coronary artery bypass graft (CABG) surgery. Design Case-control study. Setting A large academic medical center in the northeastern United States. Participants A consecutive sample of 238 patients undergoing CABG surgery. Main outcome measures Cases consisted of patients who had received either ≥ 3 U packed RBCs, ≥ 3 U platelets, ≥ 3 U fresh frozen plasma, or any cryoprecipitate within 72 h after undergoing a CABG procedure, or who had undergone surgical revision for bleeding. All other CABG surgery patients served as control subjects. Results In multivariate models that controlled for a wide variety of demographic and clinical characteristics, we found that, compared to patients who did not receive any HES during surgery, those who received 1 U intraoperative HES had more than twice the risk of a bleeding outcome (odds ratio [OR], 2.32; 95% confidence interval [CI], 1.10 to 4.91), and those who received 2 or 3 U HES had more than four times the risk of postoperative bleeding (OR, 4.57; 95% CI, 1.74 to 12.00). Conclusions HES use in patients undergoing CABG surgery may be associated with a significant risk of postoperative bleeding. A double-blinded, randomized, controlled trial will be necessary to confirm this finding.
Pain is associated with prospective memory dysfunction in multiple sclerosis

Prospective memory (PM) pertains to the execution of a future goal or behavior. Initial research implies that people with multiple sclerosis (MS) are apt to show impaired prospective memory for activities of daily living. Yet, PM impairment does not occur in all people with MS. Thus, some other variable besides disease status alone may contribute to PM dysfunction in people with MS. Chronic pain may be such a variable. Approximately 50–70% of people with MS experience significant pain, and such pain has been thought to diminish memory function. To investigate this possibility, 96 patients with MS and 29 healthy subjects were administered the Memory for Intentions Screening Test (MIST; Woods, S. P., Iudicello, J. E., Moran, L. M, Carey, C. L., Dawson, M. S., & Grant, I. (2008). HIV-associated prospective memory impairment increases risk of dependence in everyday functioning. Neuropsychology, 22, 110–117.), a well-validated measure of prospective memory, and the Medical Outcomes Study Pain Effects Scale (PE...
In vitro Maintenance of the Trophonts and Sporozoites of Pyxinia crystalligera

SYNOPSIS. In a study of in vitro maintenance of the trophonts and sporozoites of the cephaline gregarine, Pyxinia crystalligera, a basal medium consisting of salts, reducing agents, and antibiotics was supplemented by fetal bovine serum, serum protein fraction IV-4, or protein hydrolysates. Motility was used as the viability criterion. The tests were terminated when viability was ∼30% of the original inoculum. Two-week survival of trophonts was observed with 0.75% protein fraction, 80% of organisms remaining viable at the end of 1 week. Similar results were noted with 2% casein hydrolysate. With lactalbumin hydrolysate and Casamino acids trophonts remained viable for 6 days, and with fetal bovine serum the results were similar to those obtained with lower concentrations of protein fraction IV-4. Sporozoites remained motile for up to 5 days in the basal medium supplemented by both protein fraction IV-4 and diluted haemocoelic contents of the host, Dermestes vulpinus, but only for 3 days or less in that supplemented by the protein fraction alone. The characteristic crystals of trophonts were dissolved or possibly utilized during in vitro maintenance. A new type of crystal, however, was observed in forms kept in the presence of higher protein hydrolysate concentrations. Smaller trophonts were more adaptable to maintenance than larger ones, for rapid depletion of paraglycogen and resorption of the deutomerite often was observed in the latter. Results of cytochemical tests for carbohydrates, neutral lipids, and proteins indicated that the trophonts were capable of paraglycogen synthesis in vitro.
Conducting an editing workshop

A guided workshop in editing can give students and report writers an objective means of evaluating their drafts to improve the quality of writing. In each of four steps, the workshop uses three processes (identification, analysis, rewriting) to examine overall logic, verb usage, sentence openings, and conjunctions. Practical tips for objectively examining drafts provide the greatest improvement in editing one's own work.
Magma mixing in the Aleutian arc: evidence from cognate inclusions and composite xenoliths

Abstract The complexity of igneous processes in the Aleutian calc-alkaline magma series can be inferred from study of xenolithic fragments. Composite xenoliths and cognate inclusions provide direct evidence for magma—magma and wall-rock—magma mixing processes. Using distributions of Cr in clinopyroxene, compositional endmembers involved in mixing are identified within the xenoliths. The basaltic mixing endmember is more mafic than calc-alkaline lavas in the arc. Magma mixing and wall-rock assimilation within calc-alkaline basaltic to andesitic magmas is identified in phenocrystic assemblages as well as in xenoliths, and appears to be a widespread phenomenon in Aleutian calc-alkaline magmas.
Longitudinal changes in the relationship between body mass index and percent body fat in pregnancy.

Objective: To determine the longitudinal relationship between body mass index (BMI) and percent body fat in women before and during pregnancy. Methods: Twenty-seven healthy, monobese women were evaluated before conception, in early gestation (12–17 weeks), and in late gestation (33–36 weeks). Height and weight were measured and BMI was calculated. Percent body fat was estimated using hydrodensitometry with correction for residual lung volume. Results: The correlation between BMI and percent body fat before conception was r = 0.693 ( P r = 0.723 ( P r = 0.633 ( P Conclusion: In nonobese women the correlation between BMI and percent body fat remains significant during pregnancy, although the 95% CI for predicting percent body fat from the mean BMI ranges widely.
Evolution of microstructure during shape memory cycling of a main-chain liquid crystalline elastomer

Abstract The field of shape memory polymers (SMPs) has been dominated by polymeric systems whose fixing mechanism is based on crystallization or vitrification of the constituent chains, rendering such systems stiff in comparison to elastomers, gels, and living tissues. Previously, we reported the synthesis and characterization of main-chain, segmented liquid crystalline elastomers (LCEs) that exhibit both bulk and surface shape memory effects. These LCEs have excellent shape fixing and recovery characteristics with compositionally-dependent transition temperatures that determine the fixing and recovery critical temperatures. Synthesis of the soft shape memory LCEs proceeded by hydrosilylation-linking of poly(dimethylsiloxane) oligomers with mesogenic dienes of two compositions and a tetravinyl crosslinker. The present report describes microstructural changes during ex situ shape memory deformation and recovery of one such LCE. Wide-angle x-ray scattering showed that, once a critical deformation stress was reached, the microstructure of the fixed, oriented LCEs was independent of the stress applied above the clearing (isotropization) transition. Stepped recovery of the fixed, oriented LCE showed additional intermediate microstructures, however. Recovery was shown to proceed through changes in both the smectic layer thickness and chevron architecture, while mesogen tilt angle remained unchanged. The mechanical and microstructural studies described herein give deeper insight to shape memory fixing and recovery mechanisms of these unique materials, which offer potential for exploitation in areas such as cell and tissue culture, microcontact printing, and microfluidics.
Distribution of red king crabs and Tanner crabs in the summer by habitat and depth in an Alaskan fjord

A manned submersible was used in a fjord in southeastern Alaska to study the distributional patterns of the red king crab (Paralithodes camtschaticus) and the Tanner crab (Chionoecetes bairdi) in summer. The cove was divided into three zones: inner, middle, and outer. Six types of habitats, including sand-mud, rock, shell, debris, rock wall, and algae, were identified from video tapes. A relatively flat sand-mud habitat located at the center of the cove occupied 60% of the sea bottom. This large habitat was bordered by steep rocky walls on both sides in most parts of the fjord except in the inner zone. The density of red king crab decreased from the inner zone to the outer zone, while the density of the Tanner crab was more uniform throughout the cove. Highest crab density was found in the sand-mud habitat with an overall density of 51 crabs ha -1 for the red king crab and 41 crabs ha -1 for the Tanner crab. No crabs were found in rock wall and algae habitats. Both crab species displayed a dome-shaped distribution with depth with maximum density at intermediate depths. Red king crabs had a maximum density (86 crabs ha -1 ) at 70-80 m while the maximum density of Tanner crabs (105 crabs ha -1 ) was at 140-150 m of depth. Dense aggregations of juvenile red king crabs were observed in the inner cover, but no aggregations of mature red king and Tanner crabs were observed.
Monitoring large areas for forest change using Landsat: Generalization across space, time and Landsat sensors

Landsat 7 ETM+ provides an opportunity to extend the area and frequency with which we are able to monitor the Earth's surface with fine spatial resolution data. To take advantage of this opportunity it is necessary to move beyond the traditional image-by-image approach to data analysis. A new approach to monitoring large areas is to extend the application of a trained image classifier to data beyond its original temporal, spatial, and sensor domains. A map of forest change in the Cascade Range of Oregon developed with methods based on such generalization shows accuracies comparable to a map produced with current state-of-the-art methods. A test of generalization across sensors to monitor forest change in the Rocky Mountains indicates that Landsat 7 ETM+ data can be combined with earlier Landsat 5 TM data without retraining the classifier. Methods based on generalization require less time and effort than conventional methods and as a result may allow monitoring of larger areas or more frequent monitoring at reduced cost. One key component to achieving this goal is the improved availability and affordability of Landsat 7 imagery. These results highlight the value of the existing Landsat archive and the importance for continuity in the Landsat Program.
Constrained optimization for validation-guided conditional random field learning

Conditional random fields(CRFs) are a class of undirected graphical models which have been widely used for classifying and labeling sequence data. The training of CRFs is typically formulated as an unconstrained optimization problem that maximizes the conditional likelihood. However, maximum likelihood training is prone to overfitting. To address this issue, we propose a novel constrained nonlinear optimization formulation in which the prediction accuracy of cross-validation sets are included as constraints. Instead of requiring multiple passes of training, the constrained formulation allows the cross-validation be handled in one pass of constrained optimization.The new formulation is discontinuous, and classical Lagrangian based constraint handling methods are not applicable. A new constrained optimization algorithm based on the recently proposed extended saddle point theory is developed to learn the constrained CRF model. Experimental results on gene and stock-price prediction tasks show that the constrained formulation is able to significantly improve the generalization ability of CRF training.
Detection of random signals by integrated polyspectral analysis

We consider the problem of detecting an unknown, random, stationary signal (Gaussian or non-Gaussian) in Gaussian noise of known correlation structure. No other assumptions are made about the signal to be detected. We suggest two approaches utilizing both the power spectrum and the third- and fourth-order integrated polyspectra for the detection of random signals. The detector structures of the proposed approaches are derived, and their performance is evaluated via simulations and comparisons with the classical energy detector involving both Gaussian and non-Gaussian signals. It is shown that the power of one of the proposed tests is competitive with that of the energy detector for Gaussian signals, and it outperforms the energy detector for the non-Gaussian signals tested.
From a pump handle to oral rehydration therapy: a model of translational research.

Few afflictions have attracted as much attention and impacted on as many societal and biomedical areas as cholera. Dr. John Snow's studies launched the field of epidemiology, were early application...
Estrogen Receptor in Rat Adrenal Gland

Specific binding of [3H]estradiol by the cytoplasmic fraction of rat adrenal gland was studied at 0 C. The [3H]estradiol-binding component sedimented at 7 S on 5 to 20% sucrose gradients. Scatchard analysis of the cytosol binding reaction, measured by a charcoal-dextran assay, indicated a single class of estradiol binding sites of high affinity (Kd = 2.2 - 4.5 × 10-10 M) and limited number (5-22 fmol/mg cytosol protein) (n = 7). Competition studies indicated specificity of the binding reaction for the biologically active estrogens, estradiol, estrone, estriol, and diethylstilbestrol; binding of [3H]estradiol was unaffected by a 1000- fold excess of androgens, glucocorticoids, mineralocorticoids, or progesterone. The binding activity was temperature dependent (no binding was observed when incubations were performed at 25 C or above) and appeared to be by a protein since binding was destroyed by trypsin and sulfhydryl reagents, but not by ribonuclease or deoxyribonuclease. Kinetic studies indicated an appar...
The molecular basis of lung morphogenesis

To form a diffusible interface large enough to conduct respiratory gas exchange with the circulation, the lung endoderm undergoes extensive branching morphogenesis and alveolization, coupled with angiogenesis and vasculogenesis. It is becoming clear that many of the key factors determining the process of branching morphogenesis, particularly of the respiratory organs, are highly conserved through evolution. Synthesis of information from null mutations in Drosophila and mouse indicates that members of the sonic hedgehog/patched/smoothened/Gli/FGF/FGFR/sprouty pathway are functionally conserved and extremely important in determining respiratory organogenesis through mesenchymal-epithelial inductive signaling, which induces epithelial proliferation, chemotaxis and organ-specific gene expression. Transcriptional factors including Nkx2.1, HNF family forkhead homologues, GATA family zinc finger factors, pou and hox, helix-loop-helix (HLH) factors, Id factors, glucocorticoid and retinoic acid receptors mediate and integrate the developmental genetic instruction of lung morphogenesis and cell lineage determination. Signaling by the IGF, EGF and TGF-beta/BMP pathways, extracellular matrix components and integrin signaling pathways also directs lung morphogenesis as well as proximo-distal lung epithelial cell lineage differentiation. Soluble factors secreted by lung mesenchyme comprise a 'compleat' inducer of lung morphogenesis. In general, peptide growth factors signaling through cognate receptors with tyrosine kinase intracellular signaling domains such as FGFR, EGFR, IGFR, PDGFR and c-met stimulate lung morphogenesis. On the other hand, cognate receptors with serine/threonine kinase intracellular signaling domains, such as the TGF-beta receptor family are inhibitory, although BMP4 and BMPR also play key inductive roles. Pulmonary neuroendocrine cells differentiate earliest in gestation from among multipotential lung epithelial cells. MASH1 null mutant mice do not develop PNE cells. Proximal and distal airway epithelial phenotypes differentiate under distinct transcriptional control mechanisms. It is becoming clear that angiogenesis and vasculogenesis of the pulmonary circulation and capillary network are closely linked with and may be necessary for lung epithelial morphogenesis. Like epithelial morphogenesis, pulmonary vascularization is subject to a fine balance between positive and negative factors. Angiogenic and vasculogenic factors include VEGF, which signals through cognate receptors flk and flt, while novel anti-angiogenic factors include EMAP II.
First-price path auctions

We study first-price auction mechanisms for auctioning flow between given nodes in a graph. A first-price auction is any auction in which links on winning paths are paid their bid amount; the designer has flexibility in specifying remaining details. We assume edges are independent agents with fixed capacities and costs, and their objective is to maximize their profit. We characterize all strong e-Nash equilibria of a first-price auction, and show that the total payment is never significantly more than, and often less than, the well known dominant strategy Vickrey-Clark-Groves mechanism. We then present a randomized version of the first-price auction for which the equilibrium condition can be relaxed to e-Nash equilibrium. We next consider a model in which the amount of demand is uncertain, but its probability distribution is known. For this model, we show that a simple ex ante first-price auction may not have any e-Nash equilibria. We then present a modified mechanism with 2-parameter bids which does have an e-Nash equilibrium. For a randomized version of this 2-parameter mechanism we characterize the set of all eNEs and prove a bound on the total payment in any eNE.
Prediction of the Retention Behavior of lonizable Compounds in Reversed-Phase LC Using Factor- Analytical Modeling

Principal component factor analysis (PCFA) and target transformation factor analysis (TTFA) are used to examine the reversed-phase high-performance liquid chromatographic retention behavior of some neutral, basic, and acidic organic compounds in water-methanol-acetonitrile solvent systems at pH 7, 5, and 3. The ratios of the pairs of HA/A – (acid) or B/BH + (base) are controlled by the buffered mobile phases, and this permits the factor analytical model to be extended to ionic compounds. Four factors are sufficient to reproduce the data within an error margin of 3%.
Enhanced Ca2+-Activated Na+-Ca2+ Exchange Activity in Canine Pacing-Induced Heart Failure

Defective excitation-contraction coupling in heart failure is generally associated with both a reduction in sarcoplasmic reticulum (SR) Ca(2+) uptake and a greater dependence on transsarcolemmal Na(+)-Ca(2+) exchange (NCX) for Ca(2+) removal. Although a relative increase in NCX is expected when SR function is impaired, few and contradictory studies have addressed whether there is an absolute increase in NCX activity. The present study examines in detail NCX density and function in left ventricular midmyocardial myocytes isolated from normal or tachycardic pacing-induced failing canine hearts. No change of NCX current density was evident in myocytes from failing hearts when intracellular Ca(2+) ([Ca(2+)](i)) was buffered to 200 nmol/L. However, when [Ca(2+)](i) was minimally buffered with 50 micromol/L indo-1, Ca(2+) extrusion via NCX during caffeine application was doubled in failing versus normal cells. In other voltage-clamp experiments in which SR uptake was blocked with thapsigargin, both reverse-mode and forward-mode NCX currents and Ca(2+) transport were increased >2-fold in failing cells. These results suggest that, in addition to a relative increase in NCX function as a consequence of defective SR Ca(2+) uptake, there is an absolute increase in NCX function that depends on [Ca(2+)](i) in the failing heart.
Generation of telecom-band indistinguishable photon pairs in dispersion-shifted fiber

We use a 50/50 Sagnac-loop configuration to spatially separate degenerate photon pairs created via four-photon scattering in dispersion-shifted fiber, A Hong-Ou-Mandel dip with visibility > 94% is observed.
A Model for Peer and Student Involvement in Formative Course Assessment

This paper discusses a protocol and rationale for peer and student involvement in the assessment of courses in Mechanical Engineering at Stanford University. The protocol is based upon elements of good teaching practice, and on standards for peer review as used in journal publication. It has been “prototyped” in nine engineering courses over the past two years and has generally been found to be a good mechanism for near real-time monitoring that creates constructive feedback for teaching and learning quality control. Major features of this ongoing project will be summarized, including faculty attitudes and required time commitment.
Phenotypic Analysis of Random hns Mutations Differentiate DNA-Binding Activity from Properties of fimA Promoter Inversion Modulation and Bacterial Motility

H-NS is a major Escherichia coli nucleoid-associated protein involved in bacterial DNA condensation and global modulation of gene expression. This protein exists in cells as at least two different isoforms separable by isoelectric focusing. Among other phenotypes, mutations in hns result in constitutive expression of the proU and fimB genes, increased fimA promoter inversion rates, and repression of the flhCD master operon required for flagellum biosynthesis. To understand the relationship between H-NS structure and function, we transformed a cloned hns gene into a mutator strain and collected a series of mutant alleles that failed to repress proU expression. Each of these isolated hns mutant alleles also failed to repress fimB expression, suggesting that H-NS-specific repression of proU and fimB occurs by similar mechanisms. Conversely, alleles encoding single amino acid substitutions in the C-terminal DNA-binding domain of H-NS resulted in significantly reduced affinity for DNA yet conferred a wild-type fimA promoter inversion frequency, indicating that the mechanism of H-NS activity in modulating promoter inversion is independent of DNA binding. Furthermore, two specific H-NS amino acid substitutions resulted in hypermotile bacteria, while C-terminal H-NS truncations exhibited reduced motility. We also analyzed H-NS isoform composition expressed by various hns mutations and found that the N-terminal 67 amino acids were sufficient to support posttranslational modification and that substitutions at positions 18 and 26 resulted in the expression of a single H-NS isoform. These results are discussed in terms of H-NS domain organization and implications for biological activity.
Ninety-day mortality after total elbow arthroplasty.

Background: Perioperative mortality, although seldom mentioned and rare after upper-extremity surgery, is one of the potential complications of total elbow arthroplasty. The purpose of this study was to determine the prevalence and risk factors associated with perioperative mortality after elbow arthroplasty. Methods: The records of 1117 consecutive patients who had undergone 1441 total elbow arthroplasties at our institution between 1970 and 2002 were reviewed to identify patients who had died within ninety days after the procedure. A detailed analysis of the medical, surgical, anesthetic, and pathologic records of these patients was performed. Results: The ninety-day mortality rate was 0.62% (nine of 1441 cases). Seven of the patients who died were female and two were male; their mean age at the time of surgery was sixty-six years. An underlying diagnosis of distal humeral fracture (including pathologic fracture) or nonunion was associated with an increased risk of death (p < 0.001). Seven patients died after primary arthroplasty and two, after revision arthroplasty. The average time from surgery to death was forty-five days. The causes of death were congestive heart failure (three patients) and myocardial infarction, acute heart embolus, respiratory failure, pneumonia, renal failure, and bleeding secondary to gastric stress ulcer (one patient each). All patients had substantial comorbidities. Conclusions: The rate of perioperative mortality after total elbow arthroplasty is low. Most patients who die after this procedure are elderly, have substantial comorbidities, and underwent the total elbow arthroplasty for the treatment of a traumatic or pathologic distal humeral fracture or nonunion. Level of Evidence: Prognostic Level II. See Instructions to Authors for a complete description of levels of evidence.
Diabetic Retinopathy and Neuropathy

This is the seventh in a series of articles on presentations at the American Diabetes Association Annual Meeting, Orlando, Florida, 4–8 June 2004. Holger Gerhardt (Goteborg, Sweden) discussed pericytes and vascular stability in the diabetic retina, noting that these cells cover most of the endothelium and are present during the development of normal new blood vessels, while proliferative retinopathy classically shows “pericyte drop out” as an early pathological marker. It has been hypothesized that endothelial dysfunction leads to capillary occlusion and regression, causing ischemia, to which neovascularization with subsequent proliferative retinopathy is a response. In this schema, pericyte drop out may occur either before or after the stage of endothelial dysfunction. A number of markers can be used for characterizing pericytes. Mice that do not express platelet-derived growth factor (PDGF)-β have severe diffuse bleeding and die early in the neonatal period. There is diffuse pericyte loss in these mice, suggesting PDGF-β to be an important growth factor for the cells. An endothelium-specific PDGF-β knockout displays a variety of phenotypes with variable degrees of pericyte loss, with areas of pericyte-covered vessels and areas lacking pericytes and with severe retinopathy localized to the areas lacking pericytes. Gerhardt suggested that pericyte drop out is therefore sufficient to cause capillary occlusion and regression, leading to retinal ischemia. Why, though, he asked, is there a proliferative response rather than normal development of well-behaved new vessels repairing the region of ischemia, and how does retinal normal vascular development differ from that seen in neovascularization? The normal advancing vascular sprout extends “tip cells,” which appear to guide the development of the vasculature, following paths produced by astrocytes, which produce vascular endothelial growth factor (VEGF)-α in areas of hypoxia, with astrocyte VEGF-α downregulated after it becomes covered by new vessels. In the developing retina, the VEGF receptor (R)2 …
Long-term risks of bladder augmentation in pediatric patients.

Purpose of reviewBladder augmentation is still a commonly performed reconstructive procedure for pediatric patients with severe bladder dysfunction. Recent developments in the long-term risks associated with this procedure are reviewed.Recent findingsThere are metabolic changes in these patients aft
Laboratory adaptations--changing expectations.

There is a favorite aphorism attributed to Charles Mayo that states, “In the study of some apparently new problems we often make progress by reading the work of great people of the past … ” (1). Similarly, insight for the future can be gained by reflecting on the example of Dr. Arnold O. Beckman, who celebrated his 101st birthday on April 10, 2001. From his invention of the “acidimeter” (patent no. 2,058,761) to his introduction in 1940 of the DU Spectrophotometer through Beckman Instruments, which redefined “accuracy” in clinical chemistry measurements, Dr. Beckman “walked his talk”, having posited that “There is no satisfactory substitute for excellence” (2) and “When you’re faced with the necessity to do something, that’s a stimulus to invention. If (my classmate) hadn’t come in with his lemon juice problem, chances are I never in the world would have thought about making a pH meter”(2). If laboratory professionals are to heed Dr. Beckman’s call to excellence, we must first acknowledge, together with members of the diagnostics industry he helped create, a great obstacle to achieving a level of performance commensurate with patients’ needs. This challenge resides in continuing failure, individually and collectively, to define quality objectives in terms of laboratories’ clinical objectives. Although much needs to be said, has been said, and will be said relative to preanalytical and postanalytical phases of quality assurance, much too little has been said of analytical quality. Little effort has been made toward dispelling the body of collective fiction that suggests that “The quality’s the same everywhere”. Dr. N.W. Tietz has expressed concern for the degree to which we have strayed from a laboratorian’s fundamental concern with the need that procedures be accurate, precise, specific, and comparable among laboratories (3). Rudyard Kipling’s The Village That Voted the …
The enabling role of decision support systems in organizational learning

Organizations routinely process information, make decisions, and implement them. Recent advances in computer and communications technologies have changed the way in which organizations perform these functions. Decision support systems (DSSs) are a major category of tools that an organization utilizes to support and enhance its decision-making activities. Traditionally, organizations are considered to have a predefined and static set of goals. However, in order to stay competitive and survive in today's dynamic environment, organizations must be able to quickly respond and adapt to changes in their business settings. Such changes could be due to technological advances, growing and changing customer demands, competitive forces, changes in the labor force, environmental and political concerns, societal impacts, security concerns, and others. In recent years, the field of DSS has become more sophisticated to encompass such paradigms as expert systems (ESs), intelligent DSSs, active DSSs, and adaptive DSSs. Artificial intelligence (AI)-based techniques are being embedded in many DSS applications, thus enhancing the support capabilities of the DSS. Such paradigms have application potential in both individual and organizational learning contexts. However, the degree to which current DSSs can support organizational learning has yet to be investigated in depth. This paper examines the learning strategies employed by organizations and DSSs and provides a framework to demonstrate how a DSS can enhance organizational learning.
Neural Network Recognition of Spelling Errors

One area in which artificial neural networks (ANNs) may strengthen NLP systems is in the identification of words under noisy conditions. In order to achieve this benefit when spelling errors or spelling variants are present, variable-length strings of symbols must be converted to ANN input/output form---fixed-length arrays of numbers. A common view in the neural network community has been that different forms of input/output representations have negligible effect on ANN performance. This paper, however, shows that input/output representations can in fact affect the performance of ANNs in the case of natural language words. Minimum properties for an adequate word representation are proposed, as well as new methods of word representation.To test the hypothesis that word representations significantly affect ANN performance, traditional and new word representations are evaluated for their ability to recognize words in the presence of four types of typographical noise: substitutions, insertions, deletions and reversals of letters. The results indicate that word representations have a significant effect on ANN performance. Additionally, different types of word representation are shown to perform better on different types of error.