cssi/SciSciGPT-SciSciNet huggingface dataset:
The Kerr space-time near the ring singularity

We investigate the geometry of the Kerr space-time near the ring singularity. A systematic study of the mathematical and physical structure of this region reveals that the singularity in the Kerr space-time is naturally understood in terms of a subset of the immersion of the set defined byr=0 (in Boyer-Lindquist coordinates) in the Kerr space-time. It is well known that the Kerr space-time is not a differentiable manifold (due to the curvature singularity) or a topological manifold, but a well defined topological space with a structure that is manifested by the constrast in taking limits along the hypersurface atr=0 and the equatorial plane which approach singularity. We find that the ring singularity is either an edge or a self-intersection of the topological space depending on which extension of the metric throughr=0 is implemented. A major result of this analysis is the extrapolation to the general accelerating case of Carter's proof that the only nonspacelike geodesics which can reach the ring singularity are restricted to the equatorial plane. For finite magnitudes of proper acceleration, it is shown that only lightlike trajectories that asymptotically approach the null generator of the ring singularity can reach it from above or below the equatorial plane.
Astrometric calibration of array detectors

The high level of spatial uniformity in modern CCDs and other array detectors make them excellent devices for astrometric and navigational systems. However, at the level of accuracy envisioned by the more ambitious projects, current technology produces devices with significant pixel registration errors. This paper describes a technique for measuring relative pixel positions to an accuracy approaching 0.001 pixel. The technique has been applied to WF/PC II CCDs which are shown to have 500 nm step-and-repeat errors.
Sequential Modeling of White Wheat Marketing Strategies

A discrete stochastic progamming model is developed to directly maximize expected utility resulting from alternative white wheat marketing strategies. Time-series and regression techniques are used to simulate post-harvest price events. Farm characteristics and risk attitudes of a small group of Pacific Northwest wheat producers define the constraints and the objective functions for the model. The sequential formulation of the model, in which price uncertainty is continuously resolved, results in more flexible sales patterns over the marketing year than a nonsequential formulation of the problem. Alternative utility functional forms have little influence on optimal marketing plans.
Technical communique: Optimally switched linear systems

In this paper we address the problem of optimal switching for switched linear systems. The uniqueness of our approach lies in describing the switching action by multiple control inputs. This allows us to embed the switched system in a larger family of systems and apply Pontryagin's Minimum Principle for solving the optimal control problem. This approach imposes no restriction on the switching sequence or the number of switchings. This is in contrast to search based algorithms where a fixed number of switchings is set a priori. In our approach, the optimal solution can be determined by solving the ensuing two-point boundary value problem. Results of numerical simulations are provided to support the proposed method.
PASS—a multiuser parallel file system based on microcomputers

Abstract As computer applications have become more sophisticated, they have become data intensive. Such applications suffer from inadequate use of parallelism for processing data stored on secondary storage devices. Devices such as data base machines are useful in some applications, but many applications are too small or specialized to use data base machine technology. To bridge this gap, we have introduced the parallel secondary storage (PASS) system. PASS is based on a network of microcomputers. The individual microcomputers are assigned to a unit of secondary storage and the operations of the microcomputers are initiated and monitored by a control processor. The file system is capable of acting as either an SIMD or an MIMD machine depending, on the file type. Communication between the individual microcomputers and the control processor is described. The integration of the multiple microcomputers into the primitive operations on a file is examined. Finally, the strategies employed to enhance performance in the multiprogramming environment are discussed.
An improved method of encapsulation of doxorubicin in liposomes: pharmacological, toxicological and therapeutic evaluation.

We describe here an improved method of encapsulating doxorubicin in liposomes using phosphatidylcholine, cholesterol and synthetic tetramyristoyl cardiolipin. With this new composition of lipids the entrapment of doxorubicin was found to be > 90%. Cytotoxicity studies using vincristine-resistant HL-60/VCR leukaemia cells showed that liposome-encapsulated doxorubicin reverses multidrug resistance 5-fold compared with conventional doxorubicin and at levels equivalent to that obtained using liposomes with natural cardiolipin. In normal mice, liposome-encapsulated doxorubicin was much less toxic than the conventional drug. A dose of 25 mg kg-1 i.v. of conventional doxorubicin produced 100% mortality in mice by day 14, whereas liposomal doxorubicin exhibited only 10% mortality by day 60. Liposomal doxorubicin demonstrated enhanced anti-tumour activity against murine ascitic L1210 leukaemia compared with conventional doxorubicin. At a dose of 15 mg kg-1, liposomal doxorubicin increased the median life span with 12 of 18 long-term (60 days) survivors compared with only 3 of 18 with conventional drug. Mice injected i.v. with liposomal doxorubicin had plasma levels 44-fold higher than conventional doxorubicin, producing significantly higher (P < 0.02) area under the plasma concentration curve. An altered tissue distribution was also observed with liposomal doxorubicin; cardiac tissue demonstrating at least 2-fold lower levels with liposomal doxorubicin probably accounting for its lower toxicity. This altered pharmacokinetics of liposome-encapsulated doxorubicin, providing enhanced therapeutic advantage and the ability to modulate multidrug resistance, could be useful in a clinical setting.
Kinetics of Pb-rich phase particle coarsening in Sn–Pb solder under isothermal annealing–cooling rate dependence

The coarsening behavior of the Pb-rich phase particles in 63Sn–37Pb (wt%) solder was investigated following isothermal annealing treatments. Samples were exposed to cooling rates of 0.1, 1.0, 10, and 100 °C/min. Annealing temperatures were 25, 55, 70, 85, and 100 °C, and times were 2–100 days. The mean particle diameter decreased from 1.8 × 10−3 to 0.8 × 10−3 mm with increased cooling rate, indicating two solidification regimes: one for cooling rates ⩽1 °C/min and the other for cooling rates of ⩾10 °C/min. The Pb-rich phase particles coarsened more quickly in samples made at the two fastest cooling rates. There was little Pb-rich phase particle coarsening at 25 and 55 °C for all annealing times. Coarsening rate kinetics were examined specifically for the 10 and 100 °C/min data using the expression Atnexp[−ΔH/RT]. The values of n were 0.23 ± 0.11 and 0.36 ± 0.13, respectively; n was not sensitive to annealing temperature. The corresponding 1/n values indicated that the coarsening mechanism changed from a fast diffusion to a bulk diffusion controlled process with a faster cooling rate. The apparent activation energy ΔH ranged from 16 ± 8 to 41 ± 8 kJ/mol; the values increased with cooling rate from 10 to 100 °C/min. The ΔH value was sensitive to annealing temperature only for the faster cooling rate of 100 °C/min. Together, the n and ΔH values indicated that an accelerated, fast diffusion mechanism with low activation barriers characterized the Pb-rich phase coarsening in samples exposed to a slower cooling rate, greater annealing, or a combination of the two conditions. That mechanism likely originated from the in situ development of recover/recrystallization microstructures in the Sn-rich phase. At faster cooling rates, those microstructures were not as well developed, so coarsening was controlled more by the higher activation barriers of bulk diffusion processes.
Tolosa-Hunt syndrome masquerading as Gradenigo syndrome in a teenager.

Abstract Tolosa-Hunt syndrome is an idiopathic chronic granulomatous inflammatory process commonly involving the cavernous sinus and the orbit [1] . Symptoms include unilateral eye pain, ophthalmoplegia, headache, and facial pain in the distribution of the upper divisions of the trigeminal nerve and are highly responsive to steroid therapy. Gradenigo syndrome describes extension of a middle ear infection to the petrous apex, with trigeminal pain and ophthalmoplegia, typically responsive to antibiotics and often surgical drainage. We report a case of a 17 year-old girl with apparent Gradenigo syndrome, presenting with unilateral eye pain, abducens palsy, headache, hearing loss and serous otitis media, who was ultimately diagnosed with Tolosa-Hunt syndrome.
Ab initio theoretical and matrix isolation experimental studies of hydrogen bonding. IV. The HBr:pyridine complex

Abstract Experimental matrix isolation studies have been performed for the HBr/pyridine/argon system at 10 K to obtain the infrared spectrum of the isolated one-to-one HBr:pyridine complex. The experimental spectrum is consistent with those for complexes with proton-shared hydrogen bonds. Details of the experimental procedure and the analysis of the experimental spectrum are presented. Comparison of the experimental IR spectrum of the complex with the harmonic spectrum computed at MP2/6–31+G(d,p) shows that both theory and experiment agree that this complex is stabilized by a proton-shared hydrogen bond. However, discrepancies exist between computed and experimental frequency and intensity patterns. Single point calculations at MP2/6–31+G(d,p) for displacements along the normal coordinate for proton stretching produced a potential energy curve which is strongly anharmonic. The anharmonic frequency for the proton stretching mode was estimated from this curve. The ratio of the anharmonic to harmonic frequency yielded an effective force constant. The re-computed spectrum obtained with this constant is in excellent agreement with experiment.
Detecting Damage in Graphite/Epoxy Composites Using Impedance-Based Structural Health Monitoring

The impedance-based structural health monitoring method is used to successfully detect different damage mechanisms in composites and to correlate the changes in impedance measurements with the changes in the structure. Specifically, graphite/epoxy composite samples are manufactured and tested. Piezoceramic (PZT) patches are attached to the composite coupons to actuate the structure with high-frequency excitations. Bonding the patches to the sample allows changes in the structural mechanical impedance to be monitored with the electrical impedance of the PZT. Samples are tested using quasi-static tensile loading to introduce damage. To determine the extent of damage incurred, impedance signatures are acquired before and after the tensile load is applied. A change in impedance from the baseline shows the presence of damage. The amount of damage is characterized using a damage metric. Radiography is used to verify the extent of damage.
Fat-soluble vitamin levels in patients with primary biliary cirrhosis.

Abstract OBJECTIVE: To determine the occurrence of fat-soluble vitamin deficiencies and to identify clinical factors that may predict vitamin deficiency in patients with primary biliary cirrhosis (PBC). METHODS: Review of our data from a randomized, placebo-controlled trial that evaluated the efficacy of UDCA in 180 patients with PBC. We use the first available measurements of vitamin levels in each study participant. Vitamin levels for A, D, and E were measured in serum. The prothrombin time (PT) was used as a surrogate marker for vitamin K. RESULTS: The proportion of patients with fat-soluble vitamin deficiencies in the treatment and placebo groups was similar and the data sets were combined. The proportion with vitamin A, D, E or K deficiency was 33.5%, 13.2%, 1.9%, and 7.8%, respectively. In multivariate analysis, the Mayo risk score, advanced histological stage, and total cholesterol were independently associated with vitamin A deficiency whereas serum albumin levels was independently associated with vitamin D deficiency. No factors were associated with vitamin E or K deficiency in multivariate analysis owing to the few vitamin E and K deficient patients. Factors predictive of vitamin K deficiency by univariate analysis included Mayo risk score, advanced histological stage, HDL, total bilirubin, AST, and albumin. The cut-off value of the Mayo risk score with the highest sensitivity and specificity for vitamin A deficiency was 5.0. CONCLUSION: Other than deficiency of vitamin A, deficiency of fat-soluble vitamins occurs uncommonly in patients with PBC. A Mayo risk score ≥ 5 helps in selecting patients with PBC for surveillance for vitamin A deficiency.
OBSERVABILITY AND REDUNDANCY IN PROCESS DATA ESTIMATION

By analogy to the development for dynamic systems, concepts of observability and redundancy may be developed with respect to a steady state system. These concepts differ from their counterparts for dynamic systems in that they can be used to characterize individual variables and local behavior as well as system and global behavior. Relations between local observability, global observability, calculability and redundancy are established and explored in this paper. It is shown that these concepts are useful in characterizing the performance of process data estimators with regard to bias and uniqueness of an estimate, convergence of estimation procedures and the feasibility and implications of problem decomposition.
Identification of Undecane as an Alarm Pheromone of the Ant Formica argentea

We investigated the chemistry of Dufour’s gland secretions in Formica argentea Wheeler (Hymenoptera: Formicidae: Formicinae), an understudied species common in the Western and Midwestern United States and Canada. Gas chromatography–mass spectrometry reveals that undecane is the most prominent component in this ant’s Dufour’s gland extracts. Behavioral bioassays show that exposure to the compound significantly increases activity level in workers but does not act as a trail pheromone. This suggests an alarm function for undecane, which is consistent with other species of Formica. Taken with previous research, these findings provide evidence for evolutionary analyses of this character in this family of insects.
6π-Photocyclization of O-tert-butylacrylanilides. N-substitution dictates the regiochemistry of cyclization

O-tert-Butylacrylanilides with N–H substitution undergo 6π-photocyclization at the unsubstituted ortho carbon, whereas the corresponding N-methyl derivatives cyclize at the ortho carbon bearing the tert-butyl with the eventual loss of 2-methylpropene.
The effect of pickup-stripping contributions on the selection of a unique 3He optical potential

Abstract The coupling of pickup-stripping channels in 3 He elastic scattering has been shown to have a large effect on the elastic cross section at back angles for higher projectile energies. Quantitative treatment of these effects leads to the conclusion that the “deep” family of mass-3 optical potentials is selected by fitting to high energy, back angle elastic scattering data. This is in contrast to recent optical model studies which have concluded that such data can be fit only by using a “shallow” potential. Consistency is now found between those mass-3 potential families required in certain reaction studies and those indicated for elastic scattering.
1379 RATES AND ASSOCIATED RISK FACTORS FOR DLOW INDUCED HYPERGLYCEMIA (HG) IN NEONATES

We have identified rates and associated risk factors for D10W-induced HG among 636 newborns exposed to IV D10W in 2 neonatal ICU's monitored by an intensive Pediatric Drug Surveillance (PeDS) Program. DIOW-induced HG (range 110-774 mg %) was observed in 23 exposed infants (3.6%). There was a highly significant trend (X2=52.5) toward an increasing risk of HG with decreasing admission weight: Infants ≥ 1000 gm who were under stress (ie., asphyxia, sepsis, RDS and/or pneumonia) were 7 times more likely to have HG than non-stressed infants of similar weight (2.7% vs 0.4% respectively); however, stress did not appear to increase the risk of HG among infants ≥ 1000 gm. Similarly, among infants ≥ 1000 gm, increases in the average daily dextrose dose/kg of all dextrose-containing infusions increased the risk of HG, but this effect was not observed among the smaller (< 1000 gm) infants. Since HG may alter fluid balance and cerebral blood flow, it may also affect the risk of CNS bleeding or infarct. Admission weight and stress are risk factors for HG which cannot be altered; to reduce the risk of HG in very low birth weight infants or in larger infants who are under stress, physicians should carefully consider the total amount of dextrose administered (independent of fluids and electrolytes) and carefully monitor the neonate's blood glucose.
Teratogenicity and neonatal toxicity of ifosfamide in mice.

SummaryIfosfamide (IFA) is a structural analog of cyclophosphamide (CP), an alkylating agent which causes perinatal toxicity in mice. The purpose of this study was to examine the teratogenicity and neonatal toxicity of IFA in Swiss Webster mice. IFA, 0, 5, 10 and 20 mg/kg ip, was given to pregnant mice on Day 11 of gestation and teratogenic effects were determined on Day 19. In other experiments, IFA, 45 mg/kg sc, was given to 1 day old mice and growth and development were followed for 49 days. Plasma levels of IFA and CP alkylating metabolites were determined in adult mice given doses of 100 mg/kg ip. IFA, 20 mg/kg, significantly increased resorption rate to 81.2 ± 5.6% and 10 and 20 mg/kg IFA significantly reduced fetal body weight to 82.5 and 48.6% of controls, respectively. IFA, 20 mg/kg, significantly increased the incidence of open eyes, internal and external hydrocephalus, micro-melia, adactyly, syndactyly, microcaudate, kinky tail, microphakia, kidney ectopia, hydronephrosis, missing or non-ossifi...
A METHOD FOR MONITORING THE IMPACT OF SEX-ROLE STEREOTYPES ON THE THERAPEUTIC BEHAVIOR OF BEGINNING PSYCHOTHERAPISTS

A methodology for assessing the therapeutic behavior of trainees is described, and results of a pilot study are presented. Findings suggest that female therapists are likely at the outset to be less confident, directive, and interpretive and more inclined to conform to stereotypic feminine traits of passivity, warmth, and nurturance; males displayed no such clear pattern, and used both active and passive styles in therapy.
The simplest treatment alternative: the law of parsimony applied to choosing appropriate instructional control and errorless-learning procedures for the difficult-to-teach child

A method for choosing effective teaching procedures for difficult-to-teach children is proposed. Assessment of child responses duringteaching that involves gradually increasing environmental support in the learning setting is the basis for choice. The levels of environmental support in which child responses are assessed are (1) trial-and-error procedures; (2) increased environmental support involving analyses of reinforcement systems, incompatible responses, and prerequisite skills, as well as the most effective use of instructional control; and (3) errorless-learning procedures. Effects of instructions upon learning are discussed in terms of instructional detail and pacing, as well as with respect to the role of instructions in feedback and progressively delayed cue procedures. Stimulus shaping and stimulus fading are discussed in terms of the effectiveness of each for teaching children who have difficulty learning with more traditional procedures. The importance of the incorporation of criterion-related cues when utilizing stimulus shaping or fading is emphasized. It is proposed that an assessment of child responses should be made with respect to the three general levels of environmental support, as well as from sublevels within these, in order to choose the simplest but still effective alternative procedure for teaching difficult-to-teach children.
Biosynthesis of very long-chain methyl-branched alcohols during pupal development in the cabbage looper, Trichoplusia ni

Abstract Internal long-chain methyl-branched alcohols and their esters in the cabbage looper, Trichoplusia ni, were synthesized exclusively during the first half of the pupal stage. Esters were synthesized beginning on day 2 post-pupation while synthesis of free alcohols reached a maximum on days 3 and 4 post-pupation. Up to 10% of the injected [1-14C]acetate and 8% of the injected [1-14C]propionate were incorporated into esters and free alcohols, while only 2% of the injected acetate and essentially no propionate were incorporated into polar lipids. Only trace amounts of labeled acetate were incorporated into acylglycerols. Upon saponification, 98% of the radioactivity incorporated into esters was found in the alcohol fraction. Both esters and alcohols were synthesized by the tissue associated with the pupal cuticle but remained internal at all times and were not deposited on the cuticle. Very low levels of fatty acid synthetase activity were found throughout pupal development.
Simulation study of spatial resolution and sensitivity for the tapered depth of interaction PET detectors for small animal imaging

Improvements to current small animal PET scanners can be made by improving the sensitivity and the spatial resolution of the scanner. In the past, efforts have been made to minimize the crystal dimensions in the axial and transaxial directions to improve the spatial resolution and to increase the crystal length to improve the sensitivity of the scanner. We have designed tapered PET detectors with the purpose of reducing the gaps between detector modules and optimizing the sensitivity of a future-generation small animal PET scanner. In this work, we investigate spatial resolution and sensitivity of a scanner based on tapered detector elements using Monte Carlo simulations. For tapered detector elements more scintillation material is used per detector resulting in a higher sensitivity of the scanner. However, since the detector elements are not uniform in size, degradation in spatial resolution is also expected. To investigate characteristics of tapered PET detectors, the spatial resolution and sensitivity of a one-ring scanner were simulated for a system based on traditional cuboid detectors and a scanner based on tapered detectors. Additionally, the effect of depth of interaction (DOI) resolution on the spatial resolution for the traditional and tapered detectors was evaluated. All simulations were performed using the Monte Carlo simulation package GATE. Using the tapered arrays, a 64% improvement in the sensitivity across the field of view was found compared with traditional detectors for the same ring diameter. The level of DOI encoding was found to be the dominating factor in determining the radial spatial resolution and not the detector shape. For all levels of DOI encoding, no significant difference was found for the spatial resolution when comparing the tapered and the cuboid detectors. Detectors employing the tapered crystal design along with excellent DOI resolution will lead to PET scanners with higher sensitivity and uniform spatial resolution across the field of view.
An impedance index in normal subjects and in subarachnoid hemorrhage

The impedance of a hemodynamic system is defined as the ratio of each harmonic component of blood pressure to that of flow. Calculation of impedance curves has been extensively performed in the systemic circulation, leading to the recognition of reflected pressure and flow waves and clarifying the shape of ultrasound waveforms. Impedance in the human cerebral circulation has not been measured primarily because of the relative inaccessibility of simultaneous flow and pressure data in the human cerebral circulation. We defined an impedance index using the transcranial Doppler waveform for that of flow and a noninvasive applanation measure of the carotid artery pressure waveform. Middle cerebral artery velocities and carotid artery pressure waveforms were simultaneously recorded in 16 vessels from 10 normal volunteers, 42 vessels in 14 patients with aneurysmal subarachnoid hemorrhage, and 14 vessels in 7 subjects during conditions of hypocapnia, normocapnia and hypercapnia. Impedance was calculated by dividing the harmonic associated with pressure divided by that of flow, and averaging 10 to 20 such calculations. Relative impedance curves were calculated by dividing by the impedance at the first harmonic. Impedance was also studied in an electrical model consisting of a Windkessel element containing inductance in series with a second Windkessel to model the large vessel and vascular bed, respectively. Model parameters were taken from the literature for these calculations. For the normal subjects, the shape of the impedance index curve was similar to those found in the systemic circulation. The impedance index curves for patients in vasospasm (middle cerebral velocity greater than 180) showed a peak at the second or third harmonic, which appeared more frequently than the nonspasm group (p 1.0 in the spasm group but significantly <1.0 in the normal group (p < 0.05). Calculations from the electrical model replicated the appearance of these peaks at the second or third harmonic for vasospasm parameters. A statistically significant peak appeared at the second or third harmonic in the impedance index curves for patients in vasospasm, which was replicated quantitatively by our electrical model. Although such peaks can be explained in the systemic circulation by the presence of reflected waves, the distance to the reflection site is larger than expected for the cerebral circulation. This suggests the importance of the inertia of blood as a stenosis worsens and as the origin for the observed changes in the impedance index curves.
Histologically pure seminoma with elevated alpha-fetoprotein: a clinicopathologic study of ten cases.

Seminomas account for 50% of testicular germ-cell tumors, and more than 90% of these are classic seminomas. When patients with a histologically pure testicular seminoma show an elevated level of serum a-fetoprotein (AFP), it is generally assumed that an undetected focus of yolk sac tumor (YST) is present and the patient is managed with a treatment regimen for non-seminomatous tumor. We studied 10 cases of histologically pure seminoma with elevated levels of serum AFP in an attempt to identify any distinctive clinical, histopathologic, or immunohistochemical features. The patients ranged in age from 27 to 48 years (mean, 31 years). Eight patients had primary tumors of the testis, and two presented with supraclavicular and ileal tumors. The clinical stage at presentation varied: four tumors were stage I, four were stage II, and two were stage III. Serum levels of AFP were elevated in all patients at ranges of 10.4 to 16 ng/ml (mean, 12.0 ng/ml). In all patients, the primary tumors and metastases when present exhibited classic seminoma histology without other germ-cell components. The tumor cells expressed keratin in seven cases. The pattern of keratin immunoreactivity ranged from focal staining in five cases to moderate staining in two cases. All cases were negative for AFP, and the nine cases in which staining for CD30 (Ki-1) was performed were also negative. All four patients with stage I tumors underwent the conventional therapy for pure seminoma, i.e., orchiectomy and subsequent radiation therapy. Five patients received treatment for non-seminomatous tumors, i.e., chemotherapy after orchiectomy. Extensive work-up failed to detect the primary tumor in one patient, and he was treated for a non-seminomatous tumor, undergoing chemotherapy and irradiation. All patients are alive and well, and none has developed evidence of YST at a mean follow-up of 6 years (range, 6 months to 10 years). However, one patient who presented with an ileal metastasis recently developed a second primary extragonadal mediastinal mixed germ-cell tumor with YST and embryonal carcinoma components and an elevated serum level of AFP (27,000 ng/ml) after a 10-year disease-free follow-up. This study strongly suggests that minor elevations (</= 16 ng/ml) of AFP in patients with an otherwise pure seminoma may not indicate that there is a hidden focus of YST and that such patients should be treated with standard therapy for seminoma. Because this study includes very few patients, further studies are required to better understand the significance of borderline elevations of AFP in cases of histologically pure seminoma.
On a theorem of Hochstadt

In fact, Hochstadt gives an explicit formula for the discriminant which will be reproduced below. Since Hochstadt’s work there has been a considerable interest in finite-band potentials, i.e., potentials q such that the spectrum of the operator associated with d2/dx 2 + q consists of finitely many regular analytic arcs, due to their close relationship with the Korteweg-de Vries hierarchy and hence with integrable systems. However, the interest is not restricted to real-valued potentials. For instance,
Surgical Correction of Congenital Tricuspid Stenosis

Abstract The case of an adult patient with congenital tricuspid stenosis is presented. The lesion was successfully corrected with valvular commissurotomy and repair of atrial septal defect. Use of two-dimensional echocardiography in diagnosis of congenital tricuspid stenosis is discussed.
Magnetic properties of metastable fcc Fe-Cu alloys prepared by high energy ball milling

Abstract Metastable Fe-Cu alloys have been produced using a high energy ball mill. We have studied the magnetic properties of both mechanically alloyed Fe-Cu and the nanocomposite phase produced at intermediate ball milling times. The mechanically alloyed solid solutions have magnetic properties similar to those of Fe-Cu films prepared by vapor-quenching. Upon annealing at high temperatures, the metastable Fe-Cu alloys recrystallize and phase separate into Fe and Cu.
Continuous infusion fluorouracil/leucovorin and bolus mitomycin‐C as a salvage regimen for patients with advanced colorectal cancer

Background. No effective systemic salvage therapy exists for patients with advanced colorectal cancer who progress after receiving bolus fluorouracil (FU) and leucovorin (LV) chemotherapy. In vitro data suggest that bolus FU resistance can be overcome by continuous infusion (CI) FU, and that the cytotoxic effects of Mitomycin-C (MMC) and FU are synergistic. Based on this data, a Phase II trial of CI FU and LV with bolus MMC in patients with advanced colorectal carcinoma who progressed on only one previous chemotherapy regimen was performed. Methods. Twenty-eight patients with advanced colorectal carcinoma who had progressed after one previous chemotherapy regimen of bolus FU/LV were treated with bolus MMC 10 mg/m2 every 6 weeks and CI FU 200 mg/m2/day admixed with LV 10 mg/m2/day given 14 days on/7 days off. Results. The partial response rate in 24 evaluable patients was 17% (95% confidence interval, 2-32%) with a median response duration of 9.5 months (range, 4.2-12.0 months). Twelve (50%) additional patients achieved disease stabilization. Median survival was 9.9 months in the whole group (28 patients) and 11.5 months in the 24 evaluable patients. The major toxicities were grade 4 diarrhea occurring in two patients and grade 3 mucositis occurring in five patients. There was minimal myelosuppression (grade 3 thrombocytopenia in one patient) and no occurrences of hand-foot syndrome or cardiotoxicity. Conclusions. This regimen demonstrates modest activity with acceptable toxicity in colorectal cancer patients who have failed a single-bolus FU/LV regimen. Modifications of this and other infusional FU-based chemotherapy regimens should be explored as potential salvage chemotherapy regimens in advanced colorectal cancer. Cancer 1995;75:769-74.
Identification of DNMT1 (DNA methyltransferase 1) hypomorphs in somatic knockouts suggests an essential role for DNMT1 in cell survival

Previous studies have shown that DNA methyltransferase (Dnmt) 1 is required for maintenance of bulk DNA methylation and is essential for mouse development. However, somatic disruption of DNMT1 in the human cancer cell line HCT116 was not lethal and caused only minor decreases in methylation. Here, we report the identification of a truncated DNMT1 protein, which was generated by the disruption of DNMT1 in HCT116 cells. The truncated protein, which had parts of the regulatory N-terminal domain deleted but preserved the catalytic C-terminal domain, was present at different levels in all DNMT1 single-knockout and DNMT1/DNMT3b double-knockout cell lines tested and retained hemimethylase activity. DNMT1 RNAi resulted in decreased cell viability in WT and knockout cells and further loss of DNA methylation in DNMT1 knockout cells. Furthermore, we observed a delay in methylation after replication and an increase in hemimethylation of specific CpG sites in cells expressing the truncated protein. Remethylation studies after drug-induced hypomethylation suggest a putative role of DNMT1 in the de novo methylation of a subtelomeric repeat, D4Z4, which is lost in cells lacking full-length DNMT1. Our data suggest that DNMT1 might be essential for maintenance of DNA methylation, proliferation, and survival of cancer cells.
Burrowing ecology of the rare and elusive Louisiana pine snake, Pituophis ruthveni (Serpentes: Colubridae)

The burrowing ecology of 12 adult and nine juvenile Louisiana pine snakes, Pituophis ruthveni , was studied during 1995-1997 in north-central Louisiana, U.S.A. Significantly more adult burrows connected to pocket gopher ( Geomys breviceps ) tunnels than did juvenile burrows, although a relatively high number of adult and juvenile snake burrows were blind-ended. Significantly more adult snake burrows were located in pine plantations and grasslands and significantly less were located in clearcuts than expected. Significantly more juvenile snake burrows were located in pine plantations than expected. Adult and juvenile snake burrows were located in areas that had relatively less leaf litter and canopy closure than expected. Excavation behavior by P. ruthveni was stereotyped and similar to excavation behavior by the bullsnake, Pituophis catenifer sayi and the northern pine snake, Pituophis melanoleucus melanoleucus .
How Pediatric Urology Fellowships in the United States are Funded.

Background: We desired to discover how pediatric urology fellowship positions in the United States were funded. Methods: Approved pediatric urology fellowship directors (25) were contacted by email and asked how the 2 years of fellowship were funded at their institutions. Results: The response rate of the email questions was 100%. The clinical year of the fellowship was 100% hospital-funded in 88% of the 25 fellowships. The second, ABU-required year was 100% hospital-funded in only 44% of the fellowships. Clinical funds generated by pediatric urology faculty provided funding for 24% of the fellows and institutes and grants funded 20% of the fellowship positions for the second year. Thirty two percent of the fellowship positions have supplemental funding through charges generated from the fellow's clinical activities in patient care. Conclusion: All but 3 hospitals fund 100% of the clinical year of pediatric urology fellowship. Sources of funding for the second, ABU-required year vary widely among fellowship programs in the U.S.
Microfluorometric detection of asymmetry in the centromeric region of mouse chromosomes.

Abstract A lateral asymmetry in the centromeric region of mouse chromosomes is revealed in studies involving the BUdR quenching of 33258 Hoechst fluorescence. This cytologically detected asymmetry may reflect the unequal distribution of thymidine between the two chains of mouse satellite DNA.
The Pruritus Receptor Unit: A Target for Novel Therapies

Although the role of prostanoids in itch was actively studied a decade ago, interest in this area has waned in recent years. Andoh et al. (2007, this issue) demonstrate that the prostanoid thromboxane A2 elicits scratching through its TP receptor. Identification of new itch mediators and their respective receptors within the skin will undoubtedly be the focus of future drug development for this distressing symptom.
Reconfigurable microstrip antennas with dynamic radiation patterns

Reconfigurable beam antenna systems are capable of changing their radiation pattern characteristics in real time, such as beam direction, beam shape, beamwidth, etc. Such antenna system is desired for various wireless applications because it helps to enhance signal strength received from an intended target, mitigates interference, and accommodates sudden changes in traffic demand. It might also help to reduce the deployment cost of a wireless networks infrastructure.
Theory of thermo-microstretch fluids and bubbly liquids

Abstract Equations of motions, constitutive equations and boundary conditions are derived for a class of thermo-micropolar fluids whose micro-elements can undergo dynamical expansions and contractions. These fluids can have translatory and rotory motions with spin inertia and therefore can support surface tractions and couples. In addition, microelements of these fluids can stretch and contract. These degrees of freedom are reminicent of the motions of bubbly fluids where bubbles can not only move and rotate with the fluid but they can also oscillate in the manner of expansions and contractions. Thermodynamical restrictions are studied. The theory is illustrated with the solution of the problem of acoustical waves in bubbly liquids. The dispersion relations are in complete agreement with the celebrated result of Van Vijngaarden.
A MORE ECONOMICAL AND EFFECTIVE BLOOD PRODUCT FOR CHRONIC TRANSFUSIONS

Frozen red blood cells (RBCs) are commonly used in chronic transfusion programs for patients with homozygous β -thalassemia, sickle cell anemia after stroke, etc., to avoid the severe transfusion reactions due to sensitization to WBCs. An alternative technique for removal of WBCs consists of filtration on cotton wool. We have used or transfusion RBCs first filtered on cotton wool filters (Imugard IG500, Terumo Corp., Tokyo, Japan) and then washed with a solution containing NaCl 0.8%, Dextrose 0.2%, buffered with phosphate to pH 7.4. These cells appear superior to frozen RBCs, as they are less expensive to prepare ($55 vs. $119), equally free of WBCs (200/μl vs. 300/ μl), and yield an equal volume of RBCs per unit (180 vs. 170 ml). In seven splenectomized patients with homozygous β-thalassemia, we compared one year of filtered RBCs to the previous year of frozen RBCs. The transfusion interval remained unchanged (19.5 vs. 20.5 days) as did the transfusion requirement (118 vs. 125 ml/kg/yr). We noticed an improvement in p50 with the change to filtered RBCs. All of our patients with homozygous β-thalassemia have been switched to filtered RBCs: there has been no reaction in over 1500 transfusions. Filtered RBCs appear to be the product of choice for chronic transfusion programs, as they are cheaper and easier to prepare than frozen RBCs, using ordinary blood bank equipment, and probably also more effective in oxygen delivery. We recommend that all patients on chronic transfusion be switched to filtered RBCs.
A class of Loewner chain preserving extension operators

Abstract We consider operators that extend locally univalent mappings of the unit disk Δ in C to locally biholomorphic mappings of the Euclidean unit ball B of C n . For such an operator Φ , we seek conditions under which e t Φ ( e − t f ( ⋅ , t ) ) , t ⩾ 0 , is a Loewner chain on B whenever f ( ⋅ , t ) , t ⩾ 0 , is a Loewner chain on Δ . We primarily study operators of the form [ Φ G , β ( f ) ] ( z ) = ( f ( z 1 ) + G ( [ f ′ ( z 1 ) ] β z ˆ ) , [ f ′ ( z 1 ) ] β z ˆ ) , z ˆ = ( z 2 , … , z n ) , where β ∈ [ 0 , 1 / 2 ] and G : C n − 1 → C is holomorphic, finding that, for Φ G , β to preserve Loewner chains, the maximum degree of terms appearing in the expansion of G is a function of β . Further applications involving Bloch mappings and radius of starlikeness are given, as are elementary results concerning extreme points and support points.
Investigation of high-alpha lateral-directional control power requirements for high-performance aircraft

Designers of the next-generation fighter and attack airplanes are faced with the requirements of good high-angle-of-attack maneuverability as well as efficient high speed cruise capability with low radar cross section (RCS) characteristics. As a result, they are challenged with the task of making critical design trades to achieve the desired levels of maneuverability and performance. This task has highlighted the need for comprehensive, flight-validated lateral-directional control power design guidelines for high angles of attack. A joint NASA/U.S. Navy study has been initiated to address this need and to investigate the complex flight dynamics characteristics and controls requirements for high-angle-of-attack lateral-directional maneuvering. A multi-year research program is underway which includes ground-based piloted simulation and flight validation. This paper will give a status update of this program that will include a program overview, description of test methodology and preliminary results.
The content of noradrenaline and adrenaline in the rat heart after administration of Rauwolfia alkaloids.

Die chemisch verwandten Rauwolfia-Alkaloide Raunescin, Isoraunescin, Deserpidin, Rescinnamin und Reserpin verursachen einen starken Abfall des Noradrenalingehaltes des Rattenherzens, wenn sie intraperitoneal in einer Dosis von 5 mg/kg gegeben werden. Der Adrenalingehalt wird nicht deutlich oder einheitlich verandert. α-Yohimbin, das chemisch zu einer andern Gruppe gehort, hat keine Wirkung auf den Noradrenalingehalt des Herzens.
PATTERNS OF CIRCULATORY RESPONSE TO THE USE OF RESPIRATORS.

Serial determinations of the cardiac output, blood gas, and electrolyte values have revealed three basic patterns of circulatory response in 42 patients whose respiratory tidal gas exchange was assumed by a volume displacement respirator for periods up to 12 days: 1. In 15 patients with severe chest and pulmonary injuries, the cardiac indices increased from very low levels (average 1.7±0.3 L/m2/min) to 2.8±0.7 L/m2/min as profound hypoxia and acidosis were corrected. 2. Eight patients with severe bronchial obstruction or respiratory insufficiency (emphysema or pulmonary fibrosis accompanied by pneumonitis) responded by a decrease of the cardiac output from an average of 3.3 L/m2/min to 2.4±0.7 L/m2/min. Usually, in a state of combined respiratory and metabolic acidosis (pCO2 81 mm Hg, pO2 47 mm Hg), these patients became alkalotic as the arterial pCO2 approached 40 mm Hg. 3. Nine patients with low cardiac outputs (average 1.4±0.4 L/m2/min) following cardiac operations were markedly improved by use of a respirator. Although there was little change in the cardiac output (average 1.4±0.3 L/m2/min) for one or two days, metabolic acidosis was dramatically reduced (–7.4 to –1.3 mEq/L). A circulatory output previously inadequate for body perfusion became adequate when the work of respiration was removed. Ten patients with combined respiratory and cardiac dysfunction exhibited mixed circulatory reactions to the use of a respirator. From these data, it is concluded that mechanical ventilation can improve an abnormal metabolic status due to cardiac or pulmonary dysfunction by increasing blood gas exchange. When a normal cardiovascular system is present and capable of responding, cardiac output rises to a value sufficient to satisfy the total body requirements for circulation. By decreasing the perfusion requirements of the respiratory muscles, the total demand for circulation is reduced, and perfusion to other parts of the body is improved in patients incapable of elevating the cardiac output.
Nanotribology and nanomechanics of MEMS devices

MEMS devices are made of single-crystal silicon, LPCVD polysilicon films and other ceramic films. Very little is understood about tribology and mechanical characterization of these materials on micro- to nanoscales. Atomic force microscopy/friction force microscopy (AFM/FFM) techniques are increasingly used for tribological studies of engineering surfaces at scales, ranging from atomic and molecular to microscales. These techniques have been used to study surface roughness, adhesion, friction, scratching/wear, indentation, and boundary lubrication of bulk and treated silicon. Commonly measured roughness parameters are found to be scale dependent, requiring the need of scale-independent fractal parameters to characterize surface roughness. Measurements of micro-scale friction and macroscale friction show that friction values both on micro- and macroscales of all samples are about the same. The microscale values are lower than the macrovalues as there is less ploughing contribution in microscale measurements. Local variation in microscale friction is found to correspond to the local slope. Directionality in the friction is observed on microscale which results from the surface preparation and anisotropy in surface roughness. Microscratching/microwear and nanoindentation studies indicate that coated/treated silicon is superior to bare silicon. Chemically bonded lubricants appear to be suitable for MEMS devices. Finally, ultrasmooth surfaces under extremely lightly loaded conditions are required for ultralow friction and near-zero wear.
Marketing amid the Uncertainty of the Social Sector: Do Social Entrepreneurs Follow Best Marketing Practices?:

Abstract In a recent study in Journal of Marketing, Read et al. (2009) conduct an experiment to identify how experts approach marketing in uncertain, entrepreneurial contexts. In response, the current study adapts Read et al.'s model slightly to make it relevant to practicing entrepreneurs and tests it on a randomized database of experts and novices in the process of creating for-profit organizations in the United States. The results suggest that these best marketing practices are largely reflective of those employed by practitioners. The author then conducts tests to determine the degree to which social entrepreneurs employ these best marketing practices. The results suggest that social entrepreneurs are less likely than commercial entrepreneurs to implement several best marketing practices.
Observations on Eating Patterns and Rate of Food Passage of Birds Fed Pelleted and Unpelleted Diets

Abstract INCREASING the density of diets by pelleting has long been known to result in an increased growth rate and feed efficiency in birds. Experiments have been conducted in our laboratory in an attempt to determine the basis for the growth response. Allred et al. (1957a, b) concluded, that part of the response to pelleting was due to factors other than physical form, because significant growth responses were still obtained after regrinding the pellets. Subsequent studies have shown that even though small significant responses were obtained by feeding ground pellets, a much greater response was obtained by feeding whole pellets. Therefore, the greater portion of the growth response obtained by pelleting feeds apparently is accounted for by increased density. It has been a general observation that birds fed pellets can eat a given quantity of feed in a much shorter time than those fed mash. Burmeister and Card (as quoted by …