cssi/SciSciGPT-SciSciNet huggingface dataset:
Senescence Factor & Abscission of Coleus Leaves

In 1955 Osborne reported that petiole sections cut from senescent leaves of any one of many species could speed the abscission of excised and debladed bean petioles (5). The sections from senescent leaves speeded abscission if directly attached or if one attacheed an agar block on which they had stood for 24 hours. She "proposed that leaf abscissions may be controlled not only by endogenous auxins but also by some substance or substances which are produced as the leaf matures, and which reach a maximum at senescence." Similar effects were later obtained with tropical species (6). Coleus has had its normal auxin-abscission relations worked out more exactly than has any other genus, and on the basis of current information the normal abscission pattern of the clone of Coleus blumxei used by Jacobs and co-workers seems to be fully explained in terms of auxin alone (1-4, 7, 8). The evidence for auxin being the normal limiting factor for the inhibition of abscission is as follows (8). Leaves on the intact plant abscise at intervals directly related to their age. Diffusible auxin is produced by leaf blades of different ages in amounts which are significantly correlated with the normal pre-abscission intervals of the leaves. If the leaf blade is excised, the remaining petiole abscises in 4 to 6 days, irrespective of its age. And if auxin in the form of synthetic indole-acetic acid (IAA) is substitute(l for the leaf blade, then the abscission interval is restored to that of the intact leaf. Similar evidence has been obtained for the role of auxin in speeding the abscission of leaves which are either naturally aged (3), or artificially aged by deblading (1,7). Despite the evidence cited above, however, there are a number of unclarified points. Chief among them is the fact that we do not know the chemical nature of the native auxin in Coleus. When we determined the amount of diffusible auxin coming from Coleus leaves (8), operationally what we did was to find the amount of curvature obtained in the standard Avena curvature bioassay from our so called unknown blocks of agar, calibrated the assay with known amounts of synthetic IAA, and then expressed the unknown curves as if they were due to IAA alone. It is obvious that the observed decline in auxin activity per leaf could be due to a steadily increasing amount of senescence factor. This would be the more likely if senescence factor acted through interfering with the auxin metabolism of the leaf. This interpretation is supported by Osborne's data showing that senescence factor counteracted the abscission-inhibiting action of synthetic IAA on bean abscission (table 3, 5). Accordingly, the purpose of the present paper is to try to get evidence as to whether Osborne's senescence factor is present in Coleus leaves, and if so whether it increases in amount with age as auxin activity decreases. An allied interest is to see if senescence factor normally causes senescence of intact Coleus leaves, or whether it has the more restricted role of being produced in a leaf after senescence starts.
Genetic and molecular analysis of tissue-culture-derived Ac elements

Our previous experiments on maize (Zea mays L.) plants regenerated from tissue culture revealed genetic activity characteristic of the transposable element Activator (Ac) in the progeny of 2–3% of the plants tested, despite the lack of Ac activity in the progenitor plants. The objective of the present study was to determine whether the presence of Ac activity in tissue-culture-derived plants was associated with changes in the number or structure of Ac-homologous DNA sequences. Families segregating for Ac activity were obtained by crossing plants heterozygous for Ac activity onto Ac-responsive tester plants. A DNA probe derived from a previously isolated Ac sequence was used to examine the Ac-homologous sequences within individual progeny seedlings of segregating families and noncultured control materials. All plants tested had six or more Ac-homologous DNA sequences, regardless of whether Ac activity was present. In the segregating progeny of one tissue-culturederived plant, a 30-kb Ac-homologous SstI restriction fragment and a 10-kb Ac-homologous BglII restriction fragment were found to cosegregate with Ac activity. We propose that these fragments contained a previously silent Ac sequence that had been activated during tissue culture. Although one or more Ac sequences were often hypomethylated at internal PvuII and HpaII sites in plants with Ac activity, hypomethylation was not a prerequisite for activity. Reduced methylation at these sites may have been a result rather than a cause of Ac activity.
Fine structure of two-photon absorption in CdS

Abstract We have observed the fine structure of the P -excitons ( A , n = 2) in Cds through two-photon absorption. The strengths of absorption peaks of P -excitons and their dependence on the polarization of the light agree with predictions of a four-band model of two-photon absorption. Additional two-photon absorption peaks were identified as phasematched two-step two-photon processes involving second harmonic polarizations.
Increased growth produced by gelatin in trout fed meatless diets.

SummaryIt has been shown that growing trout require a diet containing fresh meat. Mixed diets devoid of fresh meat did not produce any increase in the growth of trout, Varying the nature of the dried liver fractions used did not stimulate growth. When these diets were enclosed in gelatin capsules and force fed to the fish, a marked gain in weight was obtained. Supplementing the meatless diets with gelatin resulted in satisfactory initial growth. The supplemented diets did not sustain continuing growth beyond 7 weeks suggesting that further deficiencies exist in these rations.
Anthropology as an Applied Science

Readers of this journal do not need to be reminded that social scientists and policy makers rarely agree on definitions of public welfare or on the means of achieving it. This has been especially true when there have been marked cultural differences between welfare planners and those for whom they plan; and the more so the less the beneficiaries of the planning have had to say about their future. Insofar as anthropology is concerned, this has usually meant that anthropologists who have interested themselves in applying their knowledge very often disagree with the objectives and procedures of those who are entrusted to administer the affairs of dependent peoples. There have been many attempts at collaboration, but the record of successful cooperation between specialists on human behavior and agents of government is not a lengthy one.
What the Deflationist May Say About Truthmaking

The correspondence theory of truth is often thought to be supported by the intuition that if a proposition (sentence, belief) is true, then something makes it true. I argue that this appearance is illusory and is sustained only by a conflation of two distinct notions of truthmaking, existential and non-existential. Once the conflation is exposed, I maintain, deflationism is seen to be adequate for accommodating truthmaking intuitions.
Prospective evaluation of the relationship between C-reactive protein, D-dimer and progression of peripheral arterial disease

Objective Elevated levels of C-reactive protein (CRP) and D-dimer (DD) have been associated with the presence and progression of various forms of atherosclerotic disease, particularly coronary heart disease. We hypothesize that there is a relationship between elevated levels of baseline CRP and DD and progression of peripheral arterial disease (PAD) in patients with symptomatic PAD. The current study is a prospective evaluation of this hypothesis. Methods Between 1996 and 2003, 384 subjects were enrolled in a National Institutes of Health-sponsored blinded, prospective trial evaluating the effects of multiple atherosclerotic risk factors on progression of symptomatic PAD. Baseline levels of CRP and D-dimer were obtained in 332 subjects. Subjects were followed every 6 months with clinical history and exam, ankle-brachial pressure index (ABI), and carotid artery duplex scanning (CDS). The primary study end point was a composite of ABI progression, CDS progression, stroke, myocardial infarction, amputation, and death from cardiovascular disease. Secondary end points included each of the components of the primary end point. The relationship between time to the various endpoints and baseline CRP and DD levels was examined by life-table analysis and Cox proportional hazards analysis. Results Adequate baseline samples for CRP and DD were available in 332 subjects (mean age, 67 years; 57.8% men) with mean follow-up of 38.4 months (range, 1 to 99 months). Mean baseline levels (± SD) for CRP were 0.8 ± 1.14 (range, 0.03 to 13.0), and mean DD levels were 227.4 ± 303.3 (range, 1.9 to 2744.8). Progression, as defined by the primary end point, occurred in 48.5% of subjects. Subjects with elevated CRP (highest tertile) were no more likely to have any of the progression end points than those with the lowest values (lowest tertile) ( P = NS, log-rank test, for all comparisons). By univariate analysis, subjects with elevated DD (highest tertile) were significantly more likely to die from any cause compared with subjects with the lowest DD values (lowest tertile) ( P = .03, log-rank test). They were, however, no more likely to reach any of the other progression end points, including the primary end point ( P = NS, log-rank test for all other comparisons). Multivariate analysis showed that DD level was a significant independent variable associated with occurrence of myocardial infarction (hazard ratio, 2.3; P = .02). Conclusions In subjects with symptomatic PAD, elevated baseline DD, a marker of thrombotic activity, was significantly associated with the occurrence of myocardial infarction. This study did not confirm a relationship between progression of PAD and baseline DD or CRP during the first 3 years. Baseline DD and CRP do not provide useful risk stratification in patients at high risk for progression of symptomatic PAD. Future studies should evaluate serial levels of these markers to assess their utility in predicting progression of symptomatic PAD.
The Journal of Kitchen Chemistry: A Tool for Instructing the Preparation of a Chemistry Journal Article

Writing assignments are typically incorporated into chemistry courses in an attempt to enhance the learning of chemistry or to teach technical writing to chemistry majors. This work addresses the development of chemistry-major writing skills by focusing on the rigorous guidelines and conventions associated with the preparation of a journal article. In an attempt to reproduce the entire process associated with the writing of a peer-reviewed journal article (i.e., designing an experiment, collecting data, modifying an experiment, evaluating and interpreting data, and communicating results) kitchen chemistry projects were employed. These projects facilitated the development of student work ownership and better simulated a journal-article writing experience in comparison to laboratory reports and other conventional options. Student written work was submitted to the in-house journal The Journal of Kitchen Chemistry for publication. Students responded favorably to the course structure and the kitchen chemistry ...
Effects of vitamin D3, 25-hydroxyvitamin D3, and 24,25-dihydroxyvitamin D3 on parathyroid hormone secretion.

The active vitamin D metabolite 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] causes marked suppression of both pre-proparathyroid hormone messenger RNA (pre-proPTH mRNA) and parathyroid hormone (PTH) secretion. These effects are dose dependent and reversible when tested in an in vitro primary tissue culture cell system using normal bovine parathyroid cells. In the current studies, the precursors of 1,25(OH)2D3 and the related metabolite 24,25-dihydroxyvitamin D3 [24,25(OH)2D3], were used in the same culture system to test for possible regulatory effects. The results were compared with identically prepared cells exposed to 1,25(OH)2D3. In short-term studies (30-120 minutes), none of the vitamin D-related compounds produced any effect on PTH secretion. In long-term studies (24-48 hours, using primary tissue culture in the presence of test agents), neither vitamin D3 nor 25(OH)D3 affected PTH secretion or pre-proPTH mRNA over the concentration range 10(-11)-10(-7) M. On the other hand, 24,25(OH)2D3 produced significant suppression of both pre-proPTH mRNA (77% of control, P less than .01) and PTH secretion (75% of control, P less than .005) at 10(-7) M. By comparison, 10(-11) M 1,25(OH)2D3 produced levels of suppression (25-30%) of both pre-proPTH mRNA and PTH secretion comparable to 10(-7) M 24,25(OH)2D3, while even greater suppression (40-50%) occurred at 10(-9)-10(-7) M 1,25(OH)2D3. From these studies, we conclude that vitamin D3 and 25(OH)D3 do not have significant effects on PTH synthesis and secretion over the range of doses tested.(ABSTRACT TRUNCATED AT 250 WORDS)
Endogenous estrogen receptor β is transcriptionally active in primary ovarian cells from estrogen receptor knockout mice

The estrogen receptor (ER) alpha is a hormone-inducible transcription factor that has a pivotal physiological role. Intriguingly, a clear and undisputed physiological function of the recently described ERbeta remains elusive, with the exception of the ovary where a cooperative role of ERalpha and ERbeta has been demonstrated. We have, therefore, investigated whether endogenous ERs, in particular ERbeta, act as ligand-inducible transcription factors in primary ovarian cells derived from wild-type, ERalpha or ERbeta knockout mice. Granulosa-enriched cell fractions naturally expressing ERbeta and thecal cell fractions that express ERalpha were analyzed in transactivation assays using the vitellogenin A2 consensus estrogen response element and potent ER agonists diethylstilbestrol and S-indenestrol A. We studied also the potency-selective ERbeta agonist R-indenestrol A, the pure ERalpha agonist and ERbeta antagonist R,R-diethyl-tetrahydrochrysene and the pure ERalpha agonist propylpyrazole-triol. Using ER subtype-specific physiological cell models and these ER subtype-specific structural probes, we analyzed trans-activation of ERalpha and ERbeta. This analysis revealed that endogenously expressed ERbeta is indeed functional as a transcription factor, that it responds to estrogens appropriately, and that the ligands used are true ER subtype-specific probes in primary ovarian cells. In conclusion, this study demonstrates that endogenously expressed ERbeta is capable of regulating gene transcription independent of ERalpha.
A plastic-softening model for concrete materials

Abstract A simple plasticity-based constitutive model for compressive softening of concrete materials is proposed. In this formulation, a damage parameter expressed in terms of the hydrostatic pressure is used to reflect the steep change of the stress-strain response under a low confining pressure and the gentler change of the responses under a high confining pressure. The necessary restriction required to avoid the possible contradiction between the loading criterion proposed for the softening behavior and the second law of thermodynamics for plastic deformation in the softening range is discussed.
Interdependence in the technology adoption decision among municipalities

This study examines the interdependence among municipalities in the discrete decision to adopt internet technology. Results from probit specifications with interaction effects suggest that cities are influenced by nearby neighbours with similar population size in developing a website. Evidence is also presented indicating interaction among municipalities in the decision to use internet technology to facilitate financial transactions.
Orientational dependent sensitivities of T2 and T1ρ towards trypsin degradation and Gd-DTPA2− presence in bovine nasal cartilage

To study the orientational dependencies of T2 and T1ρ in native and trypsin-degraded bovine nasal cartilage, with and without the presence of 1 mM Gd-DTPA2−. Sixteen specimens were prepared in two orthogonal fibril directions (parallel and perpendicular), treated using different protocols (native, Gd treated, trypsin-treated, and combination), and imaged using μMRI at 0° and 55° (the magic angle) fibril orientations with respect to the magnetic field B0. Two-dimensional (2D) T2 and T1ρ images were then calculated quantitatively. Without Gd, native perpendicular tissues demonstrated significant T1ρ dispersion (including T2 at the zero spin-lock field) at 0° and less dispersion at 55°, while native parallel specimens exhibited smaller T1ρ dispersion at both 0° and 55°. Trypsin degradation caused a minimum 50% increase in T1ρ. With Gd, trypsin degradation caused significant reduction in T1ρ values up to 60%. The collagen orientation in nasal cartilage can influence T2 and T1ρ MRI of cartilage. Without Gd, T1ρ was sensitive to the proteoglycan content and its sensitivity was nearly constant regardless of fibril orientation. In comparison, the T2 sensitivity to proteoglycan was dependant upon fibril orientation, i.e., more sensitive at 55° than 0°. When Gd ions were present, both T2 and T1ρ became insensitive to the proteoglycan content.
Development of a combined intravascular ultrasound and photoacoustic imaging system

Intravascular ultrasound (IVUS) imaging has emerged as an imaging technique to evaluate coronary artery diseases including vulnerable plaques. However, in addition to the morphological characteristics provided by IVUS imaging, there is a need for functional imaging capability that could identify the composition of vulnerable plaques. Intravascular photoacoustic (IVPA) imaging, in conjunction with clinically available IVUS imaging, may be such a technique allowing vulnerable plaque characterization and differentiation. We have developed an integrated intravascular ultrasound and photoacoustic imaging system to visualize clinically relevant structural and functional properties of the coronary arteries. The performance of the combined IVUS and IVPA imaging system was evaluated through images of arterial phantoms. Experiments were performed using high frequency IVUS imaging catheters operating at 20 MHz, 30 MHz and 40 MHz. The IVPA imaging was successful in highlighting inclusions based on differential optical absorption while these lesions did not have sufficient contrast in the IVUS images. Finally, initial IVUS and IVPA imaging studies were performed on ex vivo samples of a rabbit artery using the 40 MHz IVUS imaging catheter. Results of the above studies demonstrate the feasibility of combining intravascular ultrasound and photoacoustic imaging and suggest clinical utility of the developed imaging system in interventional cardiology.
Enhancing availability of the electronic image record for patients and caregivers during follow-up care.

To develop a personal computer (PC)-based software package that allows portability of the electronic imaging record. To create custom software that enhances the transfer of images in two fashions. Firstly, to an end user, whether physician or patient, provide a browser capable of viewing digital images on a conventional personal computer. Second, to provide the ability to transfer the archived Digital Imaging and Communications in Medicine (DICOM) images to other institutional picture archiving and communications systems (PACS) through a transfer engine.Method/materials: Radiologic studies are provided on a CD-ROM. This CD-ROM contains a copy of the browser to view images, a DICOM-based engine to transfer images to the receiving institutional PACS, and copies of all pertinent imaging studies for the particular patient. The host computer system in an Intel based Pentium 90 MHz PC with Microsoft Windows 95 software (Microsoft Inc, Seattle, WA). The system has 48 MB of random access memory, a 3.0 GB hard disk, and a Smart and Friendly CD-R 2006 CD-ROM recorder (Smart and Friendly Inc, Chatsworth, CA).Results: Each CD-ROM disc can hold 640 MB of data. In our experience, this houses anywhere from, based on Table 1, 12 to 30 computed tomography (CT) examinations, 24 to 80 magnetic resonance (MR) examinations, 60 to 128 ultrasound examinations, 32 to 64 computed radiographic examinations, 80 digitized x-rays, or five digitized mammography examinations. We have been able to successfully transfer DICOM images from one DICOM-based PACS to another DICOM-based PACS. This is accomplished by inserting the created CD-ROM onto a CD drive attached to the receiving PACS and running the transfer engine application.Conclusions: Providing copies of radiologic studies performed to the patient is a necessity in every radiology department. Conventionally, film libraries have provided copies to the patient generating issues of cost of loss of film, as well as mailing costs. This software package saves costs and loss of studies, as well as improving patient care by enabling the patient to maintain an archive of their electronic imaging record.
Seismic Waves in the Core of the Earth

The velocity of longitudinal waves in the earth increases with depth down to the core, at a depth of about 2,900 km., where there is a discontinuous drop from 13·7 km. to about 8 km. per sec. Within the core, the velocity has usually been calculated as increasing gradually to about 11·5 km. per sec. at the centre.
Comparative Clinical Pharmacology of Amoxicillin and Ampicillin Administered Orally

Ampicillin and amoxicillin (alpha-amino-p-hydroxybenzyl penicillin) were administered orally in 500-mg doses to eight fasting volunteers in a comparative study in which pharmacokinetic techniques were used. The absorption of amoxicillin was significantly better, as demonstrated by a higher mean peak serum concentration of 7.6 mug/ml as compared to 3.2 mug/ml for ampicillin, an average "area under the curve" that was approximately double that of ampicillin, and an 8-hr urinary recovery for amoxicillin of 60% as compared to 34% for ampicillin. Serum half-lives were the same for the two antibiotics, with values of 60.3 (+/-3.3) min for ampicillin and 61.3 (+/-5.6) min for amoxicillin. The latter drug gave measurable concentrations in the blood at 8 hr in all of eight volunteers, as compared to only three of eight with ampicillin.
Model Study of VDC ELlectric Field Effect

Energized scale models of HVDC transmission lines and converter stations can be used as design tools to determine the electric field distribution in their vicinity. To prove the method, energized scale models of a ±400-kV HVDC test line and of the Arrowhead ±250-kV converter station have been designed and built in order to compare the electric field distribution of the full-scale facilities with that of the models. Linear scale factors were 1/50 for the line and 1/33.33 for the station. The paper reviews instrumentation, modeling and scaling problems and their solutions: calibration and verification test; and discusses the accuracy of the model measurements. Comparison of corresponding ground level electric field strength test ranges shows that the agreement between full-scale and model measurements is good. Techniques were developed for full- scale and model conductor tests in laboratories, and for field and model experiments. An experimental method (the method of images) of determining the corona onset voltage of actual bipolar HVDC transmission lines with single conductors was developed. Additional experiments were conducted in various areas of the model converter station. Features studied were: electric field and ion current profiles under energized and partially deenergized conditions, effects of ground wires, and effects of shielding. The feasibility of worst case open-circuit voltage and short-circuit current measurements on model objects and vehicles was demonstrated.
Response to comment on "Iodine-129 and iodine-127 speciation in groundwater at Hanford Site, U.S.: iodate incorporation into calcite".

In his comment on our paper “Iodine-129 and Iodine-127 Speciation in Groundwater at Hanford Site, U.S.: Iodate Incorporation into Calcite”, Lu specified three concerns for Zhang et al’s study,1 including (1) precipitation mechanism (degassing vs freezing), (2) analytical methods, and (3) mass balance control. In response, comparative and comprehensive discussions on the precipitation mechanisms and iodine incorporation can be found in the paper, as well as below. This includes additional experiments of iodine distribution and speciation in calcite precipitates. In addition, the measurements of total iodine in soils/sediment were clarified below as well. The calculations on mass balance in this comment were clarified by using correct data sets. Lu proposed that freezing samples
The derived category of an exact category

There is some confusion in the literature regarding the derived category of an exact category 8. Thomason gives a satisfactory treatment of the bounded derived category in CT, 1.11.6 (see also Appendix A)]. The result is that provided all weakly split epimorphisms in 8 are admissible, the bounded derived category may be defined as usual. Although Thomason does not say it, the categories D+(6), D-(d) may also be defined in the same way. The definition of the unbounded derived category is more difficult, and is very poorly treated in the literature. For instance, in [BBD] this derived category is only defined provided every morphism in 6 admits a kernel. (See [BBD, 1.1.41; this is very unsatisfactory since very few exact categories satisfy the condition.) In this article we will show that D(B) may be defined whenever 6 is saturated (“Karoubian” in Thomason’s terminology). An exact category is saturated if every idempotent splits; i.e., 6 contains all direct summands of its objects. For the purpose of comparing with Thomason’s result, the bounded derived category is defined for more 8’s. All that is required to define Db(&) is that whenever an idempotent e: A + A factors as A f, BA A with fog=lB, then e is split. Thomason calls such idempotents weakly split, and we will honor his notation. We will show here that these constructions are in some sense best possible (Remark 1.8 for D(6), Remarks 1.9 and 1.10 for D+(d), D-(b), Db(6)). There are two reasons why I wrote this note. One is to correct the misconceptions in the literature. But, more importantly, the proof of the key result, Lemma 1.2, depends on an important characterization of tpaisse subcategories due to Rickard, and this article is intended to highlight Rickard’s criterion: a full triangulated subcategory Y of a triangulated
Anion and electron solvation in alcohols

Pulse radiolytic techniques have been used to measure the solvation of anions and electrons in alcohols. The results have shown the importance of the microscopic liquid structure in the solvation process. The activation energy for benzophenone solvation is equal to the hydrogen-bond energy for the liquids, which shows that the solvent reorganization requires the breaking of the hydrogen bonds between solvent molecules. For electron solvation, primary alcohols have a lower activation energy because the initial hydrogen-bonded structure of the liquid is amenable to solvation. The solvation of an electron in a secondary alcohol requires require hydrogen-bond breakage.
Teacher Collaboration across and within Schools: Supporting Individual Change in Elementary Science Teaching

The purpose of this study was to develop an understanding of how collabora- tion among teachers from several schools, and with university researchers, facilitated these el- ementary teachers as they attempted change in their practices. The collaboration effort was built into an in-service project for elementary teachers that focused on assisting teachers to implement a curriculum emphasizing problem-centered learning in science. The project in- volved 24 teachers in a 3-week summer workshop and an intensive follow-up research pro- gram during the following school semester. Our understanding of the relationship between change and the collaborative experience was developed from multiple data sources, including transcripts of interviews and group meetings, lesson plans and other teacher produced arti- facts, and field notes from classroom observations. Our analysis of the data indicates that col- laboration facilitates change because it provides opportunities for teachers to learn both content and pedagogical knowledge from one another, encourages teachers to be risk takers in implementing new ideas, and supports and sustains the processes of individual change in sci- ence teaching. © 1997 John Wiley & Sons, Inc. Sci Ed 81:51 - 65, 1997.
LibQUAL+™ and the small academic library

Washburn is a Carnegie Master’s University I with an enrollment of only 6,200 students. Unlike most of the 43 participating libraries in LibQUAL+™ 2001, Washburn University’s Mabee Library is not a large, academic research library. The paper describes Washburn’s experience with the 2001 LibQUAL+™ pilot project. The application of the survey at a small institution and the global nature of trends shown by the responses will be discussed. LibQUAL+™’s place within the strategic planning and assessment program at Washburn’s Mabee Library is also reviewed.
The suprachiasmatic nuclei: circadian phase-shifts induced at the time of hypothalamic slice preparation are preserved in vitro

Neurons of the suprachiasmatic nuclei (SCN) of the hypothalamus compose a primary oscillator which organizes circadian rhythms in mammals. In cultured hypothalamic slices from rat brain, the SCN diurnal oscillation in neuronal firing rate continued unperturbed when slices were prepared during the light phase of the donor's light/dark cycle. However, when slices were prepared during the donor's dark period, the rhythm was phase-shifted. The sign and shape of the phase-response relationship for resetting in the isolated oscillator is very similar to that for intact animals, except that in isolation the SCN oscillator undergoes large shifts during the first cycle. The finding that a phase-shifting stimulus at the time of brain slice preparation causes normal phase readjustment in vitro demonstrates that the underlying mechanism is endogenous to the SCN and can be probed in the brain slice.
Two-step optimal thermal generation scheduling

Abstract A new approach to the solution of the optimal thermal generation scheduling problem is presented. The problem is solved in two steps. As a first step, the optimal production schedule for the next day is obtained based on a daily load forecast, reserve capacity requirements, and present status of generating units. The second-step algorithm uses the results of the first step and adjusts the previous schedule to meet new constraints developed during the course of the day. Variable truncation dynamic programming is proposed as a new method to reduce computation effort. To eliminate the need for solving the entire problem again in the second step, a new technique that limits the solution space to be searched is presented. Use of approach is illustrated via examples.
Surgical treatment of right atrial focal tachycardia in adults

Abstract Although successful operative treatment of atrial focal tachycardia has been reported in children, there are only isolated reports of surgical treatment of this arrhythmia in adults. In this case series of eight patients (aged 10 to 53 years) with drug-resistant right atrial focal tachycardia, results of electrophysiologic studies, surgical techniques and long-term follow-up are described. Atrial focai tachycardia was reproduced during etectrophysiologic study, and endocardial mapping localized the earliest onset of atrial activation in the right atrium in all patients. Epicardial mapping confirmed the location of atrial tachycardia foci in seven of eight patients whose tachycardia was inducible intraoperatively. Of four patients treated with epicardial cryoablation alone, two had recurrent tachycardia and required a second procedure. None have had arrhythmia recurrence, in all four patients aftar right atrial excision (two of whom had intraoperative recurrence of atrial focal tachycardia alter epicardial cryoablation alone), there has been no recurrence during a clinical follow-up period of 11 to 67 mouths (mean 30). It is concluded that in adult patients 1) electrophysiologic study with endocardial and epicardial mapping permits successful surgical treatment of atrial focal tachycardia; 2) epicardial cryoablation alone may be associated with recurrence of atrial focal tachycardia either intraoperatively or postoperatively; and 3) subtotal right atrial resection appears to be a well tolerated procedure with no long-term recurrence of atrial focal tachycardia.
The effect of surface species on the photoluminescence of porous silicon

The photoluminescence of porous Si immersed in alcohol exhibits a blue shift and a marked decrease in intensity relatively to dry, as-anodized wafers. However, when the immersed samples are treated with ultraviolet (UV) light for a few minutes, the photoluminescence (PL) peak shifts to longer wavelength. Fourier transform infrared spectroscopy reveals that alkoxy surface species and silicon hydride species backbonded to oxygen atoms appear on the UV-treated samples. Furthermore, the PL characteristics and surface species of the UV-treated samples can be recovered to those of as-anodized wafers by dipping in hydrofluoric acid. These results point out the importance of surface chemistry in the luminescence process of porous Si.
Role of chemotaxis in the transport of bacteria through saturated porous media

Populations of chemotactic bacteria are able to sense and respond to chemical gradients in their surroundings and direct their migration toward increasing concentrations of chemicals that they perceive to be beneficial to their survival. It has been suggested that this phenomenon may facilitate bioremediation processes by bringing bacteria into closer proximity to the chemical contaminants that they degrade. To determine the significance of chemotaxis in these processes it is necessary to quantify the magnitude of the response and compare it to other groundwater processes that affect the fate and transport of bacteria. We present a systematic approach toward quantifying the chemotactic response of bacteria in laboratory scale experiments by starting with simple, well-defined systems and gradually increasing their complexity. Swimming properties of individual cells were assessed from trajectories recorded by a tracking microscope. These properties were used to calculate motility and chemotaxis coefficients of bacterial populations in bulk aqueous media which were compared to experimental results of diffusion studies. Then effective values of motility and chemotaxis coefficients in single pores, pore networks and packed columns were analyzed. These were used to estimate the magnitude of the chemotactic response in porous media and to compare with dispersion coefficients reported in the field. This represents a compilation of many studies over a number of years. While there are certainly limitations with this approach for ultimately quantifying motility and chemotaxis in granular aquifer media, it does provide insight into what order of magnitude responses are possible and which characteristics of the bacteria and media are expected to be important.
The Impact of Exchange Lineage on Customers' Responses to Service Debacles and Subsequent Recovery

Established relationships between marketers and their clients are highly valuable to firms because they lead to customers' repeat purchase behavior and also lower the firms' operating costs. Additionally, existing relationships may cause consumers to disregard negative experiences with marketers. In this study, consumers experience an incident of poor product performance for which blame is attributable to the seller. The findings demonstrate that customers who had prior relationships with a seller will be less dissatisfied, more loyal, less likely to terminate doing business with that seller, and unlikely to spread negative word-of-mouth than patrons who did not have prior relationships with the seller. These findings have strategic implications for maintaining customer relationships and designing service recovery measures.
First-Principles Interatomic Potentials for Transition Metals and Their Surfaces

For bulk transition metals, a first-principles generalized pseudopotential theory (GPT) of interatomic potentials has been developed in which the cohesive-energy functional takes form of a volume term plus sums over widely transferable two-, three-, and four-ion potentials. The GPT has been further extended to surfaces by making an internal transformation of this functional to an embedded-atom-like format in which the embedding function is identified as the bulk volume term and the atomic volume is replaced by an average electron density. Applications of the bulk and surface GPT to the calculation of structural, vacancy-formation, and surface energies in Cu and Mo, and to the investigation of surface relaxation and reconstruction in Mo are discussed. 26 refs., 2 figs., 4 tabs.
Optimum Grain Size in the Christiansen Filter

The width at half-maximum of the band transmitted by a Christiansen filter has been measured for ten wave-lengths, and for glass grains of six sizes in ethyl salicylate. With a cell 7.5 mm thick, the grain size affording the narrowest bands was found to be about 0.7 mm, depending somewhat upon wave-length. Bands have been observed in the violet, having a width at half-maximum as narrow as 8 to 10A, the transmission at peak being about 40 percent.
A three-axis micromachined accelerometer with a CMOS position-sense interface and digital offset-trim electronics

This paper describes a three-axis accelerometer implemented in a surface-micromachining technology with integrated CMOS. The accelerometer measures changes in a capacitive half-bridge to detect deflections of a proof mass, which result from acceleration input. The half-bridge is connected to a fully differential position-sense interface, the output of which is used for one-bit force feedback. By enclosing the proof mass in a one-bit feedback loop, simultaneous force balancing and analog-to-digital conversion are achieved. On-chip digital offset-trim electronics enable compensation of random offset in the electronic interface. Analytical performance calculations are shown to accurately model device behaviour. The fabricated single-chip accelerometer measures 4/spl times/4 mm/sup 2/, draws 27 mA from a 5-V supply, and has a dynamic range of 84, 81, and 70 dB along the x-, y-, and z-axes, respectively.
The View from an Elder: Closing Essay

The author explores the shapeshifting of Wart, the young King Arthur in T.H. White's The Once and Future King, as a metaphor for professional and personal transformation as a librarian. The shape shift has been an attitude shift, a mental reshaping, of a librarian come lately to the field. Concerns about the staying power of new technology coexist with the magical gift of connection from tools like Google.
Familial Hypercholesterolemia: new therapeutic approaches

Familial Hypercholesterolemia (FH) is caused by a mutation in the gene that encodes the low-density lipoprotein (LDL) receptor, resulting in very high levels of circulating LDL-cholesterol and endothelial damage during time. Apoprotein B, activated by LDL receptor, and PCSK9 (proprotein convertase subtilisin / kexin type 9 serine Protease), that impairs the clearance of LDL receptors, are important additional mechanisms that lead to increase LDL-cholesterol. The prevalence of Homozigous form (HoFH) is estimated to be 1 per 1 million individuals and, if untreated, proximal coronary disease or aortic valve disease frequently occurs during childhood and most affected patients suffer from fatal coronary disease before the age of 30. Heterozygous condition (HeFH) occurs in about 1/380-500 individuals. The levels of LDL-cholesterol in this form may greatly vary but the disease is always asymptomatic until adult age when there is a high risk of early cardiovascular disease. Lifestyle intervention and maximal statin therapy are the mainstays of treatment. In patients that not achieve LDL-C targets, primarly HoFH patients, adjunctive lipoprotein apheresis is recommended where available. Biological agents represents to date a new therapeutic approach for this not so rare condition. The PCSK9 pathway is one of the best examples of how genetics has led to identification of a new target for cholesterol management. Different PCSK9 inhibitors (alirocumab, evolocumab) are now available [1]. Mipomersen is an antisense oligonucleotide (ASO) that targets apoliporotein B-100 mRNA and disrupts its function: it is distributed mainly to the liver where it silences apoB mRNA, thereby reducing hepatic apoB-100 and giving rise to reductions in plasma total cholesterol, LDL-cholesterol, and apoB concentrations [2]. Lomitapide is a microsomal triglyceride transfer protein (MTP) inhibitor. MTP resides in the lumen of the endoplasmic reticulum, thereby preventing the assembly of apo B–containing lipoproteins in enterocytes and hepatocytes. This inhibition leads to a reduction in the synthesis of chylomicrons and very low–density lipoprotein, resulting in a reduction in plasma LDL levels [3].
Dispersion-relation-preserving FDTD algorithms for large-scale three-dimensional problems

We introduce dispersion-relation-preserving (DRP) algorithms to minimize the numerical dispersion error in large-scale three-dimensional (3D) finite-difference time-domain (FDTD) simulations. The dispersion error is first expanded in spherical harmonics in terms of the propagation angle and the leading order terms of the series are made equal to zero. Frequency-dependent FDTD coefficients are then obtained and subsequently expanded in a polynomial (Taylor) series in the frequency variable. An inverse Fourier transformation is used to allow for the incorporation of the new coefficients into the FDTD updates. Butterworth or Chebyshev filters are subsequently employed to fine-tune the FDTD coefficients for a given narrowband or broadband range of frequencies of interest. Numerical results are used to compare the proposed 3D DRP-FDTD schemes against traditional high-order FDTD schemes.
Regulation of differentiation and polarized secretion in mammary epithelial cells maintained in culture: extracellular matrix and membrane polarity influences

Several previous studies have demonstrated that mammary epithelial cells from pregnant mice retain their differentiated characteristics and their secretory potential in culture only when maintained on stromal collagen gels floated in the culture medium. The cellular basis for these culture requirements was investigated by the monitoring of milk protein synthesis and polarized secretion from the mouse mammary epithelial cell line, COMMA-1-D. Experiments were directed towards gaining an understanding of the possible roles of cell-extracellular matrix interactions and the requirements for meeting polarity needs of the epithelium. When cells are cultured on floating collagen gels they assemble a basal lamina-like structure composed of laminin, collagen (IV), and heparan sulfate proteoglycan at the interface of the cells with the stromal collagen. To assess the role of these components, an exogenous basement membrane containing these molecules was generated using the mouse endodermal cell line, PFHR-9. This matrix was isolated as a thin sheet attached to the culture dish, and mammary cells were then plated onto it. It was found that cultures on attached PFHR-9 matrices expressed slightly higher levels of beta-casein than did cells on plastic tissue culture dishes, and also accumulated a large number of fat droplets. However, the level of beta-casein was approximately fourfold lower than that in cultures on floating collagen gels. Moreover, the beta-casein made in cells on attached matrices was not secreted but was instead rapidly degraded intracellularly. If, however, the PFHR-9 matrices with attached cells were floated in the culture medium, beta-casein expression became equivalent to that in cells cultured on floating stromal collagen gels, and the casein was also secreted into the medium. The possibility that floatation of the cultures was necessary to allow access to the basolateral surface of cells was tested by culturing cells on nitrocellulose filters in Millicell (Millipore Corp., Bedford, MA) chambers. These chambers permit the monolayers to interact with the medium and its complement of hormones and growth factors through the basal cell surface. Significantly, under these conditions alpha 1-, alpha 2-, and beta-casein synthesis was equivalent to that in cells on floating gels and matrices, and, additionally, the caseins were actively secreted. Similar results were obtained independently of whether or not the filters were coated with matrices.(ABSTRACT TRUNCATED AT 400 WORDS)
Survival of Verapamil-Poisoned Rats Treated with Triiodothyronine

Life-threatening toxicity due to calcium channel blocker ingestion is commonly encountered by emergency medicine physicians and toxicologists. Despite a vast array of research on its treatment, results have proven inconsistent. The goal of this study is to evaluate potential vasopressor effects of triiodothyronine (T3) in rats poisoned with verapamil. Following anesthesia and intubation, ten Sprague–Dawley rats were given intravenous verapamil infusion of 10 mg/kg/h. This dose was titrated until a mean arterial pressure (MAP) of 50–55 mmHg was achieved and maintained for a period of at least 5 min. The verapamil infusion was then maintained at that rate. Five rats were randomized to receive a T3 bolus of 0.4 mcg/kg preceding an infusion of 1.5 mcg/kg/day which was doubled every 2 min until any of the following endpoints: systolic blood pressure of 100 mmHg, an elapsed time of 60 min, or death. The other five received an equal volume of normal saline solution. The primary outcome measure was survival with secondary outcomes of MAP and heart rate. The T3 group did have a slightly longer, yet not statistically significant, average time to cessation of electrical activity—30.0 ± 14.4 min versus 23.8 ± 9.5 min in the placebo group. Average MAP decreased nearly identically in the two groups. Heart rates were not reliable indicators of toxicity in this rat model as there was little decrease until immediately prior to death in most animals. Despite significant variability in toxicity among individual animals, no statistically significant difference in survival time, heart rate, or MAP was found between groups treated with T3 and those receiving saline.
Effects of Different Antibiotics on Performance, Processing Characteristics, and Parts Yield of Broiler Chickens

Abstract Broilers were grown to 49 days of age on diets supplemented with bambermycins (BAM, 2.2 ppm), bacitracin methylene disalicylate (BMD, 27.5 ppm), virginiamycin (VM, 11 ppm), or an unmedicated control. Samples of birds were processed for dressing percentage and parts yield. There were no significant (P>.05) effects of antibiotics on final body weight, feed conversion, or mortality. In male broilers, BMD and VM significantly (P≤.05) increased dressing percentage and percentage yield and reduced the skeletal rack as a percentage of postchill weight compared to those fed the nonmedicated control. All antibiotics significantly increased breast skin weight and breast skin as a percentage of postchill weight of as compared with those fed the unmedicated control. In female broilers, BAM and BMD significantly increased dressing percentage and percentage yield and increased breast weight and breast as percentage of postchill weight as compared with those fed the unmedicated control diet. Females fed BMD also had significantly heavier leg quarters and breast skin than those fed the unmediated control. Females fed VM had increased breast skin weight and breast skin as a percentage of postchill weight than those fed the unmedicated control. The results of the present study indicate that antibiotics may influence dressing percentage and parts yield in the absence of improvements in body weight gain or feed utilization.