cssi/SciSciGPT-SciSciNet huggingface dataset:
Genotoxic evaluation of chronic fluoride exposure: sister-chromatid exchange study

Abstract As part of a continuing investigation, this study was conducted to examine the genotoxic effects of chronic exposure to sodium fluoride (NaF) in drinking water on the frequency of sister-chromatid exchange (SCE) in the bone-marrow cells of male Chinese hamsters. Animals at about 3 weeks of age were randomly assigned to 6 groups, each with at least 3 hamsters, and were maintained on a low fluoride diet (
Simvastatin inhibits expression of tissue factor in advanced atherosclerotic lesions of apolipoprotein E deficient mice independently of lipid lowering: potential role of simvastatin-mediated inhibition of Egr-1 expression and activation

Recent studies suggest that the beneficial effects of 3-hydroxy-3-methylglutaryl coenzyme A (HMG CoA) reductase inhibitors (statins) in reducing cardiovascular events may in part, be independent of their capacity to lower plasma lipids. To test this hypothesis, simvastatin (50 mg/kg/d) was administered to 30-week-old apolipoprotein E deficient mice (apo E-/-) for 12, 18 and 24 weeks. In contrast to other experimental models and humans, simvastatin treatment increases plasma cholesterol levels in apo E-/- mice. Quantitative real-time polymerase chain reaction was used to quantify expression of tissue factor (TF) and monocyte chemoattractant protein-1 (MCP-1) in the aorta of each mouse. Expression of TF was reduced to 34, 24, and 13% of control levels at 12, 18 and 24 weeks, respectively, of simvastatin administration. Advanced lesions in the innominate arteries of the simvastatin treated mice had reduced levels of TF, fewer macrophages and reduced expression of early growth response-1 (Egr-1). In vitro studies in mouse macrophages demonstrated decreased lipopolysaccharide induced binding of nuclear proteins to the Egr-1 consensus DNA sequence following pretreatment with simvastatin. RNA levels for MCP-1 were reduced to 30% of control values following 24 weeks of simvastatin treatment. In conclusion, these data suggest that chronic administration of simvastatin to older apo E-/- mice can inhibit the expression of pro-thrombotic/pro-inflammatory genes within established atherosclerotic lesions via mechanisms that are independent of reductions in plasma lipids.
The co-occurrence and systematic significance of pregeijerene B and 8-alpha-acetoxyelemol in Juniperus

The identity of a major unknown component in Juniperus volatile leaf oils has recently been determined as pregeijerene B. The occurrence of pregeijerene B in Juniperus is shown to be highly correlated with 8-α-acetoxyelemol. These compounds are shown to be present in section Sabina, but absent in sections Caryocedrus and Juniperus. In section Sabina, these compounds are very common among the smooth leaf margined, one seeded junipers of the eastern hemisphere and the smooth leaf margined junipers of the western hemisphere. Pregeijerene B and 8-α-acetoxyelemol are thought to arise from 8-α-acetoxyhedycaryol, accounting for their co-occurrence.
A Whole Body Thenmal Model of Man During Hyperthermia

A whole body thermal model of man has been developed to predict the changes in regional temperatures and blood flows during hyperthermia treatments with the miniannular phased array (MAPA) and annular phased array (APA) applicators. A model of the thermo-regulatory response to regional heating based on the experimental and numerical studies of others has been incorporated into this study. Experimentally obtained energy deposition patterns within a human leg exposed to the MAPA were input into the model and the results were compared to those based upon a theoretical deposition pattern. Exposure of the abdomen to the APA was modeled with and without the aberrant energy deposition that has been described previously. Results of the model reveal that therapeutic heating (42°C) of extremity soft tissue sarcomas is possible without significant systemic heating. Very high bone temperatures (50°C) were obtained when the experimental absorption pattern was used. Calculations show that systemic heating due to APA exposure is reduced via evaporative spray cooling techniques coupled with high-velocity ambient air flow.
The long and short of it: The unpredictability of late deciding voters

We examine the long- and short-campaign forces and their effects on the error variance in models of presidential voting decisions. Using a heteroskedastic probit allows a separate equation for the error variance and thus insight into campaign effects on voter uncertainty. Controlling for political sophistication, partisan strength and ambivalence, the choices of voters deciding later in the campaign are consistently less predictable. This is important because the number of late deciders has increased in recent elections. Furthermore, ambivalence and residing in a battleground state are stronger sources of error variance among late deciders.
Phytoplankton growth in the Ohio, Cumberland and Tennessee Rivers, USA: inter-site differences in light and nutrient limitation

Seasonal patterns in resource limitation of phytoplankton growth were assessed monthly within three large rivers with differing extents of water regulation. The Ohio River is regulated by low dams that do not substantially modify discharge, while the Cumberland and Tennessee Rivers are impounded by a series of high dams to enhance water storage for downstream flood control. Laboratory dilution assays with light and nutrient manipulations indicated that light was the main factor limiting phytoplankton growth at irradiances below 7 E m−2 d−1. Light limited growth was frequent in the turbid, higher discharge of the Ohio River, but was rare in the heavily regulated Tennessee and Cumberland Rivers. When irradiance exceeded 7 E m−2 d−1, phytoplankton were either P-limited (Cumberland River), co-limited by P and N (Tennessee River), or Si limited (Ohio River). Site-specific differences in nutrient limitation were consistent with differences in ambient nutrient levels, with the Tennessee and Cumberland Rivers characterized by lower N and P concentrations, and the Ohio River by lower Si. Downstream nutrient depletion was evident in the Ohio River through comparison of an upstream and a downstream site, with nutrient limitation (Si) occurring more frequently downstream. Phytoplankton growth rates at ambient light and nutrient levels ranged from 0.1 to 1.5 d−1 in the Ohio River and 0.2 to 0.6 d−1 in the Tennessee and Cumberland Rivers. Growth rates were greatest at the onset of the summer base pool, as light intensities increased and nutrient levels were maximal. Our findings indicate that multiple factors regulate phytoplankton growth in regulated rivers and that spatial complexity may arise from differences in discharge and water aging.
A Destructive Sampling Method Designed for Outsourcing Situations Involving High Quality Production Processes

In outsourcing situations involving manufacturing and assembly, the sampling of units produced is important since in many situations not all of the units can be tested. Destructive sampling, which commonly occurs in the assembly and manufacturing industry, is a form of sampling where all units produced cannot be tested since the parts are destructively tested. In this situation, sampling techniques are used to determine if an entire lot should be accepted or rejected based on the sampling results. The traditional sampling techniques include single or classical sampling, double sampling, multiple sampling, skip-lot sampling, chain sampling and MIL-STD-105E. The purpose of this paper is to develop a sophisticated technique that monitors quality at a lower cost than traditional methods yet has similar monitoring characteristics in situations where quality is high and tests are destructive. The proposed technique, Destructive Sampling Method for High Quality production processes (DSM-HQ), is based on a cost function, which balances the costs of sampling versus the costs of finding a defect on the field. DSM-HQ assumes to have a Poisson process defect pattern and uses an Empirical Bayesian analysis to allow the researcher to include prior knowledge.
Breast cancer detection using neutron stimulated emission computed tomography: prominent elements and dose requirements.

Neutron stimulated emission computed tomography (NSECT) is being developed to noninvasively determine concentrations of trace elements in biological tissue. Studies have shown prominent differences in the trace element concentration of normal and malignant breast tissue. NSECT has the potential to detect these differences and diagnose malignancy with high accuracy with dose comparable to that of a single mammogram. In this study, NSECT imaging was simulated for normal and malignant human breast tissue samples to determine the significance of individual elements in determining malignancy. The normal and malignant models were designed with different elemental compositions, and each was scanned spectroscopically using a simulated 2.5 MeV neutron beam. The number of incident neutrons was varied from 0.5 million to 10 million neutrons. The resulting gamma spectra were evaluated through receiver operating characteristic (ROC) analysis to determine which trace elements were prominent enough to be considered markers for breast cancer detection. Four elemental isotopes ({sup 133}Cs, {sup 81}Br, {sup 79}Br, and {sup 87}Rb) at five energy levels were shown to be promising features for breast cancer detection with an area under the ROC curve (A{sub Z}) above 0.85. One of these elements - {sup 87}Rb at 1338 keV - achieved perfect classification atmore » 10 million incident neutrons and could be detected with as low as 3 million incident neutrons. Patient dose was calculated for each gamma spectrum obtained and was found to range from between 0.05 and 0.112 mSv depending on the number of neutrons. This simulation demonstrates that NSECT has the potential to noninvasively detect breast cancer through five prominent trace element energy levels, at dose levels comparable to other breast cancer screening techniques.« less
Sensitivity of top-down estimates of CO sources to GCTM transport

[1] Estimates of CO sources derived from inversions using satellite observations still exhibit discrepancies. Here, we conduct controlled inverse analyses to elucidate the influence of model transport on the robustness of regional CO source estimates. We utilized Model of Ozone and Related chemical Tracers global chemical transport models (GCTM) driven by National Centers for Environmental Prediction and European Centre for Medium-Range Weather Forecast reanalyses, and GEOS-Chem GCTM driven by Global Modeling and Assimilation Office assimilated meteorology to generate response functions for prescribed regional CO sources. We find that inter-model differences in CO due to differences in transport are within 10–30% of inter-model mean CO concentration. However, these differences can translate to regionally significant spread in source estimates. While we find that CO source estimates for East Asia and North Africa are reasonably robust, we find inconsistencies and inter-model spread of greater than 40% in our source estimates for Indonesia, South America, Europe and Russia. This indicates the need for rigorous assessment on uncertainties in top-down source estimates through model inter-comparisons and ensemble approaches.
The recognition of sentences in noise by normal-hearing listeners using simulations of cochlear-implant signal processors with 6–20 channels

Sentences were processed through simulations of cochlear-implant signal processors with 6, 8, 12, 16, and 20 channels and were presented to normal-hearing listeners at +2 db S/N and at −2 db S/N. The signal-processing operations included bandpass filtering, rectification, and smoothing of the signal in each band, estimation of the rms energy of the signal in each band (computed every 4 ms), and generation of sinusoids with frequencies equal to the center frequencies of the bands and amplitudes equal to the rms levels in each band. The sinusoids were summed and presented to listeners for identification. At issue was the number of channels necessary to reach maximum performance on tests of sentence understanding. At +2 dB S/N, the performance maximum was reached with 12 channels of stimulation. At −2 dB S/N, the performance maximum was reached with 20 channels of stimulation. These results, in combination with the outcome that in quiet, asymptotic performance is reached with five channels of stimulation, demonstrate that more channels are needed in noise than in quiet to reach a high level of sentence understanding and that, as the S/N becomes poorer, more channels are needed to achieve a given level of performance.
Accurate measurement of heteronuclear dipolar couplings by phase-alternating R-symmetry (PARS) sequences in magic angle spinning NMR spectroscopy.

We report a Phase-Alternating R-Symmetry (PARS) dipolar recoupling scheme for accurate measurement of heteronuclear 1H-X (X = 13C, 15N, 31P, etc.) dipolar couplings in MAS NMR experiments. It is an improvement of conventional C- and R-symmetry type DIPSHIFT experiments where, in addition to the dipolar interaction, the 1H CSA interaction persists and thereby introduces considerable errors in the dipolar measurements. In PARS, phase-shifted RN symmetry pulse blocks applied on the 1H spins combined with π pulses applied on the X spins at the end of each RN block efficiently suppress the effect from 1H chemical shift anisotropy, while keeping the 1H-X dipolar couplings intact. Another advantage over conventional DIPSHIFT experiments, which require the signal to be detected in the form of a reduced-intensity Hahn echo, is that the series of π pulses refocuses the X chemical shift and avoids the necessity of echo formation. PARS permits determination of accurate dipolar couplings in a single experiment; it is suitable for a wide range of MAS conditions including both slow and fast MAS frequencies; and it assures dipolar truncation from the remote protons. The performance of PARS is tested on two model systems, [15N]-N-acetyl-valine and [U-13C,15N]-N-formyl-Met-Leu-Phe tripeptide. The application of PARS for site-resolved measurement of accurate 1H-15N dipolar couplings in the context of 3D experiments is presented on U-13C,15N-enriched dynein light chain protein LC8.
Long-term follow-up of extracapsular cataract extraction and posterior chamber intraocular lens implantation in patients with uveitis

Abstract Objective The objective of the study was to determine the long-term outcome of patients with uveitis who underwent extracapsular cataract extraction (ECCE) and posterior chamber intraocular lens (PCIOL) implantation. Design Retrospective review. Participants Twenty-eight patients (36 eyes). Intervention Extracapsular cataract extraction and PCIOL implantation. Main outcome measures Level of best-corrected Snellen visual acuity, change in visual acuity, length of follow-up, long-term findings, and complications. Results In long-term follow-up (mean, 81.4 months), 94% of eyes had visual acuity improvement compared with preoperative levels. Average change in visual acuity for all eyes was an improvement of 6.4 Snellen lines; 75% of eyes were 20/40 or better. The prevalences of cystoid macular edema (CME), epiretinal membrane (ERM), and posterior capsule opacification (PCO) were 56%, 56%, and 58%, respectively. Conclusions Patients with uveitis who are treated with ECCE with PCIOL implantation can have successful visual results in long-term follow-up despite the prevalence of PCO or macular abnormalities such as CME and ERM.
S100β expression in Alzheimer's disease: Relation to neuropathology in brain regions

Abstract S100β levels in tissue homogenates and distribution of S100β-containing activated astrocytes were examined by S100β-specific ELISA and immunohistochemistry, respectively, in brain regions exhibiting many, some, few, or no neuritic plaques in Alzheimer's disease (AD). Compared to samples collected at similar postmortem intervals from control patients of similar ages, S100β levels were elevated in specific brain regions from AD patients, and the overexpression of S100β correlated relatively well with the pattern of regional involvement by neuritic plaques. The largest increases in S100β levels were in hippocampus and temporal lobe, followed by frontal lobe and pons, with no elevation in occipital lobe or cerebellum. Immunohistochemical analysis showed S100β localization primarily in activated astrocytes surrounding neuritic plaques. These results demonstrate that S100β overexpression is brain region-specific and related to astrocyte activation and suggest that elevation of S100β above some threshold is related to the degree of neuropathological involvement of different brain regions in AD.
Simple preparation and stabilization of nickel nanocrystals on cellulose nanocrystal

Abstract Nickel nanocrystals were simply prepared on carbon through a thermal reduction process at 400–500 °C under N 2 after Ni(II) ions were deposited and stabilized on cellulose nanocrystal (CNXL) surface. Hydroxyl groups on the CNXL anchor and stabilize Ni(II) ions. Well-dispersed Ni nanocrystals on the carbonized CNXL were about 5–12 nm in size. XRD, FE-SEM, and TEM were employed to characterize the products.
STRUCTURE AND STABILITY OF γ‐CRYSTALLINS‐V. COVALENT AND NONCOVALENT PROTEIN‐PROTEIN INTERACTIONS IN PHOTOSENSITIZED REACTIONS

— Irradiation of γ-crystallins with 300 nm light or with the photosensitizers riboflavin or methylene blue (MB) leads to intermolecular cross-linking and insolubilization. Sodium dodecyl sulfate polyacrylamide gel electrophoresis studies reveal that these cross-links are composed of nondisulfide covalent bonds. The water-insoluble phase is stabilized by noncovalent forces, as denaturants readily dissolve it. High-performance liquid chromatography and electrophoresis results further indicate that the higher multimers are part of this water-insoluble fraction only, with the exception of MB-sensitized reactions, which are also able to produce a water-soluble, high-molecular-weight protein of at least 1 million. Labeling the external sulfhydryl groups with iodoacetamide does not prevent the photoreac-tions; however, a reducing agent such as dithiothreitol does. A mechanism involving initial oxidation and interaction of sulfhydryl groups (forming an intramolecular disulfide) buried within the protein as a necessary precursor to polymerization and precipitation has been proposed in the preceding paper. The present study provides support for this mechanism.
Thyroid and pituitary gland activity during compensatory renal hypertrophy

Des etudes autoradiographiques avec la thymidine tritiee ont mis en evidence l'augmentation de la synthese de l'acide deribonucleique et la proliferation cellulaire de la thyroide et de la pituitaire pendant l'hypertrophie compensatoire renale.
Deterrence and the death penalty: Why the statistics should be ignored

Is the death penalty a deterrent? Does it dissuade potential murders from killing? Many studies say it does, many studies say it does not; but “all of the research about deterrence and the death penalty done in the past generation … should be ignored” said a recent headline summarising a report from the National Research Council. Daniel Nagin co-edited the report. He explains why the statistics are no guide.
Regulation of human COL9A1 gene expression. Activation of the proximal promoter region by SOX9.

The COL9A1 gene contains two promoter regions, one driving expression of a long α1(IX) chain in cartilage (upstream) and one driving expression of a shorter chain in the cornea and vitreous (downstream). To determine how the chondrocyte-specific expression of the COL9A1 gene is regulated, we have begun to characterize the upstream chondrocyte-specific promoter region of the human COL9A1 gene. Transient-transfection analyses performed in rat chondrosarcoma (RCS) cells, human chondrosarcoma (HTB) cells, and NIH/3T3 cells showed that the COL9A1 promoter was active in RCS cells but not HTB or NIH/3T3 cells. Inclusion of the first intron had no effect on promoter activity. In transient-transfection analyses with promoter deletion constructs, it was found that full promoter activity in RCS cells depended on the region from −560 bp to +130 bp relative to the transcriptional start site (+1). Sequence analysis of the region from −890 bp to the transcriptional start predicted five putative SOX/Sry-binding sites. Mutation analysis revealed that two of three putative SOX/Sry binding sites within the −560 to +130 bp region are responsible for most of the COL9A1 promoter activity in RCS cells. Co-transfection experiments with a SOX9 expression plasmid revealed that a construct containing the five putative SOX/Sry-binding sites was transactivated 20- to 30-fold in both HTB and NIH/3T3 cells. Further co-transfection experiments showed that two of the SOX/Sry-binding sites located within the −560 to +130 bp region were required for full transactivation. However, mutation and deletion analyses indicated that a region from −560 to −357 bp, which does not contain any other conspicuous SOX9 sites, is also important for full promoter activity. DNA-protein binding assays and super-shift analysis revealed that SOX9 can form a specific complex with one of the SOX/Sry-binding sites with in the −560 to +130 region.
Prosthetic management of edentulous mandibulectomy patients. Part II. Clinical procedures

Abstract This article is concerned with prosthetic principles relevant to the postsurgical conditions of radical mandibular surgery, and it demonstrates clinical procedures designed especially for these problems. Clinical observations concerning the value of this prosthetic technique have been made. A controlled clinical study of 30 mandibulectomy patients was undertaken in order to make an objective assessment of the procedures. The results will be discussed in Part III of this series.
Trends in adoption of Wingspan stents

Two recent BMJ articles have criticised the US Food and Drug Administration for approving the Wingspan stent used for intracranial stenting (ICS) to prevent recurrent stroke despite insufficient evidence of its effectiveness.1 2 They also draw attention to the FDA’s inadequate response to recent evidence from the SAMMPRIS randomised controlled trial against the use of ICS in these patients. We share …
Even parity states in O16

Abstract Even parity states in O 16 are studied using the shell model in the jj coupling scheme with a zero-range, spin-dependent residual interaction. This necessitates consideration of both one particle-one hole excitations through two oscillators shells and two particle-two hole excitations. The unperturbed energy spectrum is taken from data of the single particle levels in O 15 and O 17 . Energy eigenvalues and eigenfunctions have been obtained for spin and isospin values J π ( T ) = 0 + (0, 1, 2), 1 + (0, 1), 2 + (0, 2), 3 + (0), 4 + (0, 1). Transition matrix elements for photo and electro-excitation are computed. An extensive comparison of these results with experimental data on energy levels below 20 MeV has been carried out. Reasonable agreement is obtained for those levels with well-established spin and isospin assignments. In addition, some support is provided for tentative assignments drawn from nuclear reaction data. Comparison above 20 MeV, where there is a high density of predicted even parity levels, is made difficult by the dearth of experimental data. In contrast to the rather satisfactory results for energy values, electron scattering from factors as well as the pair emission rate from the lowest 0 + level are generally much smaller than the observed values, although form factor shapes appear to agree with the limited available data.
Mural endocarditis caused by Corynebacterium mustelae in a dog with a VSD.

A 6 yr old female spayed large Munsterlander was evaluated following a 3 wk history of lethargy, inappetence, intermittent fever, and a recent change to the timing of her previously diagnosed heart murmur. Physical examination revealed marked dehydration, lethargy, and a grade 5/6 to-and-fro heart murmur that was auscultated best at the right sternal border. The dog was febrile, and echocardiography revealed a large, mobile, vegetative lesion in the right ventricular outflow tract associated with a ventricular septal defect (VSD). Mild aortic insufficiency was present. Corynebacterium mustelae (C. mustelae) was isolated from a pooled blood culture. Treatment of infective endocarditis (IE) was initiated along with supportive care, and the patient was discharged 9 days later. The dog remained without clinical signs 132 days after discharge. VSD is rarely mentioned as a predisposing factor for development of IE in veterinary literature; however, this report highlights that dogs with a VSD may be at risk for ...
The leidenfrost reactor: a new general purpose direct-cooled reactor and its use for low temperature polymerizations

Inspired by the Leidenfrost phenomenon a direct-cooled general purpose low-temperature reactor has been developed and its applicability for polymerizations was demonstrated. The Leidenfrost reactor is efficiently cooled by introducing relatively inexpensive liquid N2 (LN2) directly into the bulk of polymerization charges and the rapid evaporation of the coolant chills the system. The gaseous N2 generated provides an inert gas blanket that protects moisture and/or air sensitive charges. The installation of expensive cooling jackets or coils is superfluous and stirring is optional. The virtually complete recovery of cooling energy is possible. In the Leidenfrost reactor the LN2 heat sink is virtually in contact with the heat source so that the path of heat transfer is practically nil. Reactor fouling is eliminated which is of particular interest in butyl rubber manufacture. Constant temperature control is readily accomplished by regulating the input rate of the coolant and undesirable temperature jumps are suppressed. Continuous operation is possible. The operation of the Leidenfrost reactor is illustrated by the polymerization of isobutylene at −60°C.
A case of sickle‐cell anaemia: A commentary

on 'Abnormal human haemoglobins. I. The comparison of normal human and sickle-cell haemoglobins by ' f ingerpr int ing" by V.M. Ingrain Biochim. Biophys Acta 28 (1958) 539-545 with 'II. The chymotryptic digestion of the trypsin-resistant 'core' of haemoglobins A and S' by J.A. Hunt and V.M. Ingram Biochim. Biophys. Acta 28 (1958) 546-549 (summary) and 'III. The chemical difference between normal and sickle cell haemoglobins' by V.M. Ingram Biochim. Biophys Acta 36 (1959) 402-411 (summary)
An impact plume model for atmospheric holes in the FUV dayglow

A transient decrease in FUV dayglow emission from a ∼ 10 3 km 2 region of Earth's upper atmosphere is one expected outcome of the collision of a stony meteoroid as small as 50 cm in diameter. Computational models of the entry of projectiles between 210 and 21,000 kg predict the ejection of low-density plumes of air from the stratosphere and mesosphere at velocities of up to 5 km/s. The plumes reach an altitude of over 1000 km, displacing the atomic O-rich thermosphere, and replacing it with photoelectron- and O-poor air from beneath 80 km. The FUV dayglow is normally dominated by O emissions so the plume appears as a dark spot when viewed from above. FUV dayglow holes are reported at rates ∼ 10 4 -10 6 larger than the impact flux of objects in the size range modeled here, suggesting either 1) the observed rate is greatly overestimated, 2) there is an additional mechanism, or 3) much smaller impactors (which we have not modeled) can also generate FUV darkening plumes.
Pediatric turbinate reduction by coblation

Enlargement of the inferior turbinates is a common cause of nasal obstruction in children. Inferior turbinate reduction by coblation is an effective, safe, and minimally invasive surgical procedure in children. The indications for this surgery are being evaluated and expanded. It can be performed in addition to an adenoidectomy, adenotonsillectomy, functional endoscopic sinus surgery, or septoplasty. It can also be performed as an isolated procedure for nasal obstruction due to chronic rhinitis after medical treatment has failed to provide adequate relief. This article will provide the reader with a detailed description of the current indications and the technique of inferior turbinate reduction by coblation.
Some reflections on the international waste trade and emerging nations

Recent years have seen the emergence of a new industry dealing in the international disposal of garbage and various forms of waste. Emerging nations have become disposal sites for materials emanating from the developed world. Attempts to explain the rationale behind the international waste trade. Discusses the acceptance of garbage and waste by poorer nations as a public policy issue. Attempts to balance the economic logic of the acceptance decision with various ethical considerations. Concludes that waste should never be accepted but rather that the advisability of such a practice is destination‐specific and must be assessed on a case by case basis.
Spermidine, a sensor for antizyme 1 expression regulates intracellular polyamine homeostasis

Although intracellular polyamine levels are highly regulated, it is unclear whether intracellular putrescine (PUT), spermidine (SPD), or spermine (SPM) levels act as a sensor to regulate their synthesis or uptake. Polyamines have been shown to induce AZ1 expression through a unique +1 frameshifting mechanism. However, under physiological conditions which particular polyamine induces AZ1, and thereby ODC activity, is unknown due to their inter-conversion. In this study we demonstrate that SPD regulates AZ1 expression under physiological conditions in IEC-6 cells. PUT and SPD showed potent induction of AZ1 within 4 h in serum-starved confluent cells grown in DMEM (control) medium. Unlike control cells, PUT failed to induce AZ1 in cells grown in DFMO containing medium; however, SPD caused a robust AZ1 induction in these cells. SPM showed very little effect on AZ1 expression in both the control and polyamine-depleted cells. Only SPD induced AZ1 when S-adenosylmethionine decarboxylase (SAMDC) and/or ODC were inhibited. Surprisingly, addition of DENSpm along with DFMO restored AZ1 induction by putrescine in polyamine-depleted cells suggesting that the increased SSAT activity in response to DENSpm converted SPM to SPD, leading to the expression of AZ1. This study shows that intracellular SPD levels controls AZ1 synthesis.
Organic geochemistry of sediments from chemosynthetic communities, Gulf of Mexico slope

We used a research submersible to obtain 33 sediment samples from chemosynthetic communities at 541–650 m water depths in the Green Canyon (GC) area of the Gulf of Mexico slope. Sediment samples from beneath an isolated mat of H2S-oxidizing bacteria at GC 234 contain oil (mean = 5650 ppm) and C1–C5 hydrocarbons (mean = 12,979 ppm) that are altered by bacterial oxidation. Control cores away from the mat contain lower concentrations of oil (mean = 2966 ppm) and C1–C5 hydrocarbons (mean = 83.6 ppm). Bacterial oxidation of hydrocarbons depletes O2 in sediments and triggers bacterial sulfate reduction to produce the H2S required by the mats. Sediment samples from GC 185 (Bush Hill) contain high concentrations of oil (mean = 24,775 ppm) and C1–C5 hydrocarbons (mean = 11,037 ppm) that are altered by bacterial oxidation. Tube worm communities requiring H2S occur at GC 185 where the sea floor has been greatly modified since the Pleistocene by accumulation of oil, thermogenic gas hydrates, and authigenic carbonate rock. Venting to the water column is suppressed by this sea-floor modification, enhancing bacterial activity in sediments. Sediments from an area with vesicomyid clams (GC 272) contain lower concentrations of oil altered by bacterial oxidation (mean = 1716 ppm) but C1–C5 concentrations are high (mean = 28,766 ppm). In contrast to other sampling areas, a sediment associated with the methanotrophic Seep Mytilid I (GC 233) is characterized by low concentration of oil (82 ppm) but biogenic methane (C1) is present (8829 ppm).
Characterization of an Estrogen Receptor in the Testis of the Urodele Amphibian Necturus maculosus

The exceptionally high rate of aromatization previously demonstrated in the testis of the urodele amphibian Necturus maculosus prompted us to investigate estrogen binding activity in this tissue. When crude cytosolic extracts were incubated with (3 HI estradiol prior to DNA-cellulose affinity chromatography or sucrose gradient centrifugation, no estrogen binding was detected. Under these conditions, the presence of an endogenous estrogen-conjugating system in the crude cytosol resulted in extensive conversion of radiolabeled tracer to sulfoconjugates which presumably were poor receptor ligands; however, when this enzyme was first removed from the crude cytosol by fractionation through DNA-cellulose columns, DNA-adhering components could then be labeled with radioactive estradiol. This post-labeling method revealed an estrogen binding component with the physicochemical properties of a classical estrogen receptor: high affinity (Kd”�10’’#{176});low capacity (2-5 fmol/mg protein); and affinity for estrogenic steroids only. On sucrose gradients the estrogen receptor complex eluted from DNA-cellulose had a sedimentation coefficient of 4.7-5S. Estrogen receptors having properties similar to the cytosolic form were also demonstrated in nuclear extracts prepared from testes of untreated animals, suggesting that translocation of estrogen synthesized from endogenous precursors is a normal in vivo occurrence in this species. Preliminary measurements indicate that both cytoplasmic and nuclear estrogen receptors may show seasonal changes keyed to the annual reproductive cycle. We reported earlier that estrogen binding activity in the crude cytosol of Necturus testis is located mainly in regions comprised of differentiating or fully differentiated Leydig cells. Further studies of aromatization, the estrogen receptor system, and the estrogen-conjugating enzyme in Necturus testis may provide new insights into the role of intratesticular estrogen in male reproduction.
Community Service‐Learning: A Model for Teaching and Activism

A pedagogical movement of sorts has been developing over the past several years whereby college students engage in off-campus and out-of-classroom activities for a particular kind of learning experience. This approach, here referred to as community service-learning, has captured the attention of academics throughout the U.S. who believe that service-learning experiences should be added to the more traditional classroom teaching ubiquitous in colleges and universities. This essay reviews the basic philosophy behind service-learning and traces its emergence as a particular kind of pedagogical approach in service of civic engagement and social responsibility. The article also describes the service-learning program developed by Cornell University whereby college students learn by coming to know and by working in low-income neighborhoods that includes interning at a model public school in Brooklyn, New York.
Format in Instruction Manuals: Applications of Existing Research:

Research in cognitive psychology, instructional technology, and human fac tors applies to formatting complex instructions for equipment and procedures. Formatting includes typographic cueing of pro...
Angular Dependence of Scattering from Escherichia coli Cells

The scattering of visible light from randomly oriented systems of heterogeneous E. coli cells in water was measured as a function of angle for 10–90°. The cells are assumed to be prolate ellipsoids of revolution whose dimensions are independently measured. For these cultures the average cell volume and axial ratio is 0.6 μ3 and 2.81, respectively. Using the measured dimensions, the Rayleigh-Debye approximation for the homogeneous ellipsoid was used to calculate theoretical scattering. A newly developed Rayleigh-Debye equation for a coated ellipsoid was also used. Both cell models lead to good theory–experiment agreement, especially the coated ellipsoid model. The absolute position of the two observed scattering minima and the wavelength dependence of these positions is in excellent agreement with the theoretical predictions. The existence of the scattering minima in randomly oriented heterogeneous cultures of E. coli is attributed to the uniformity of their minor axes.
Girls' Doll Play in Educational, Virtual, Ideological and Market Contexts: a case analysis of controversy

The purpose of this study was to explore an example of girls' doll play in contemporary US culture, including its virtual, political, marketing, and other contextual meanings. The narrative that provoked the analysis was a brief news report about a controversial school function - a school fund-raiser fashion show featuring American Girl doll costumes. The show was cancelled when advocacy groups asserted connections between American Girl dolls and pro-abortion, pro-lesbian groups. The textual analysis of this case found complicated interconnections between the education and the culture and politics of doll play, Web support for that culture, the role of merchandizing related to doll play, assumptions about the relationship of play to schooling, morality, and Web communications that seem to enable communities with diverse perspectives on girls and their doll play. The evolution of play's meanings for child development appears to be complicated by connections to the Web, politics ascribed to toys and toy manufacturers, and the web of connections between toys and the larger economic context.
Informal repression, zero-sum politics and late third wave transitions

Transitions to multiparty politics occurred throughout Sub-Saharan Africa with remarkable speed in the early 1990s, linking the region to the broader ‘third wave of democratisation’ which, from 1974, progressively marked many areas of southern Europe, Latin America and post-communist Europe. Unlike most earlier cases of political reform, however, the changes in Sub-Saharan Africa demonstrated a strong external orientation. A unique combination of donor pressure, internal opposition and ‘snowballing’ led regimes to rapidly introduce multiparty politics regardless of whether ruling elites in fact supported democratisation. The particular constraints surrounding these transitions place much of Sub-Saharan Africa at high risk of civil violence. Drawing on the cases of Cameroon, Rwanda and Kenya, this article argues that, during transitional periods, the greater the conflict between ruling elites and opposition forces, and the greater the pressure which regimes face to proceed with reform, the greater the likelihood that states will sponsor ‘informal repression’, covert violations by third parties, to regain political control.
Fault-Tolerant Consensus in Directed Graphs

Consider a point-to-point network in which nodes are connected by directed links. This paper proves tight necessary and sufficient conditions on the underlying communication graphs for solving the following fault-tolerant consensus problems: Exact crash-tolerant consensus in synchronous systems, Approximate crash-tolerant consensus in asynchronous systems, and Exact Byzantine consensus in synchronous systems.The problem of asynchronous Byzantine consensus in directed graphs remains open. Prior work has developed analogous necessary and sufficient conditions for undirected graphs [11,3,9]. However, the conditions for undirected graphs are not adequate to completely characterize these consensus problems in directed graphs. Moreover, the algorithms for directed graphs presented in this paper are substantially different from those previously developed for undirected graphs. Other prior work on directed graphs has explored somewhat different problems than those solved in this paper.
Bis(tert-butylamido)- and bis(arylamido)cyclodiphosph(III)azane complexes of Ti, V, Zr and Hf: ligand substituent effects and coordination number

Syntheses and structures of [{(ButNP)2(ButN)2}MCl2], M = Zr, Hf, [{(ButNP)2(ArN)2}TiCl2], Ar = Ph, m-Tol, p-Tol, and of [{(ButNP)2(PhN)2}VCl·THF], are reported. In the solid-state these compounds are seco-heterocubic metal complexes featuring one η3-coordinated bis(amido)cyclodiphosphazane ligand. When ZrCl4 and HfCl4 are treated with {(ButNP)2(PhNLi·THF)2}, however, the diligand complexes [{(ButNP)2(PhN)2}2M], M = Zr, Hf are isolated.
Challenges of Work Voices of Persons With HIV Disease

Because of recent advances in medications and treatment regimens, persons with HIV disease are maintaining better health status and living longer. Thus, greater opportunities exist for these individuals to either continue their current employment or return to the world of work. The purpose of this qualitative study was to provide in-depth descriptions of related vocational experiences of persons with HIV. Data were collected from eight focus groups consisting of a diverse sample of people living with HIV (N = 93). Results support the need for counseling psychologists and other mental health professionals to address real and perceived barriers, both internal and contextual, while also becoming advocates for persons with HIV who want to work. A model derived from qualitative data analysis provides visual representation of the work experiences of people living with HIV, for potential application in assessment and treatment.
Proportional odds ratio model for comparison of diagnostic tests in meta-analysis

Consider a meta-analysis where a 'head-to-head' comparison of diagnostic tests for a disease of interest is intended. Assume there are two or more tests available for the disease, where each test has been studied in one or more papers. Some of the papers may have studied more than one test, hence the results are not independent. Also the collection of tests studied may change from one paper to the other, hence incomplete matched groups. We propose a model, the proportional odds ratio (POR) model, which makes no assumptions about the shape of OR p , a baseline function capturing the way OR changes across papers. The POR model does not assume homogeneity of ORs, but merely specifies a relationship between the ORs of the two tests. One may expand the domain of the POR model to cover dependent studies, multiple outcomes, multiple thresholds, multi-category or continuous tests, and individual-level data. In the paper we demonstrate how to formulate the model for a few real examples, and how to use widely available or popular statistical software (like SAS, R or S-Plus, and Stata) to fit the models, and estimate the discrimination accuracy of tests. Furthermore, we provide code for converting ORs into other measures of test performance like predictive values, post-test probabilities, and likelihood ratios, under mild conditions. Also we provide code to convert numerical results into graphical ones, like forest plots, heterogeneous ROC curves, and post test probability difference graphs. The flexibility of POR model, coupled with ease with which it can be estimated in familiar software, suits the daily practice of meta-analysis and improves clinical decision-making.
Tracking lysozyme unfolding during salt-induced precipitation with hydrogen exchange and mass spectrometry

We utilized electrospray ionization mass spectrometry (ESI-MS) and hydrogen-deuterium exchange (HX) to detect unfolding of hen egg white lysozyme during salt-induced precipitation. Deuterated lysozyme was dissolved in protonated buffer at pH 2.16 and precipitated with ammonium sulfate, sodium chloride, and potassium thiocyanate. ESI-MS was used to detect mass differences in lysozyme due to the loss of deuterons for solvent protons, providing insight on the conformational history of the protein during the labeling experiment. Precipitation with ammonium sulfate and sodium chloride did not unfold lysozyme, consistent with the known stabilizing effects of kosmotropic salts. Potassium thiocyanate, an aggressive chaotrope, was an effective precipitant at 0.2 M, but also disrupted lysozyme structure and caused the formation of precipitate fractions that did not readily redissolve into aqueous solution without the use of a chemical denaturant. Precipitation with 1.0 M thiocyanate resulted in faster rates of unfolding and larger amounts of the insoluble precipitate. The unfolding kinetics were biphasic, exhibiting a slow phase after a few hours that presumably reflected a smaller propensity for lysozyme to unfold in the precipitated state. Bimodal mass distributions in the ESI-MS spectra for the thiocyanate precipitates indicate two states for lysozyme in this system, a native and a molten globule-like partially unfolded state. ESI-MS analysis of the insoluble precipitates indicated that they consisted primarily of protein molecules that had unfolded. Investigation of the HX behavior of lysozyme in a KSCN solution at low protein concentrations confirmed the destabilizing effect of the salt on the protein structure, even when there was almost no solid phase present. The HX/ESI-MS results provide insight into the mechanism combining precipitation and denaturation for such a system, both in terms of obtaining quantitative kinetic and stability information and the identification of the conformers present. © 2001 John Wiley & Sons, Inc. Biotechnol Bioeng 71: 194–207, 2000/2001.
Frameworks of desire

search of newspaper stories covering scienti1⁄2c research on homosexuality shows that the popular press has settled on this analytic framework to explain homosexuality: either genes cause homosexuality, or homosexuals choose their lifestyle.1 The mischief that follows such a formulation is broad-based and more than a little pernicious. Religious fundamentalists and gay activists alike use the genes-choice opposition to argue their case either for or against full citizenship for homosexuals. Biological research now arbitrates civil legal proceedings, and the idea that moral status depends on the state of our genes overrides the historical and well-argued view that we are “endowed by [our] Creator with certain unalienable Rights . . . . ” Moreover, rather than framing research projects in terms of the whole of human desire, we neglect to examine one form, heterosexuality, in favor of uncovering the causes of the ‘deviant’ other, homosexuality. Intellectually, this is just the tip of the iceberg. When we invoke formulae such as oppositional rather than developmental, innate versus learned, genetic versus chosen, early-onset versus adolescent experience, a gay gene versus a straight gene, hardwired versus flexible, nature versus nurture, normal versus deviant, the subtleties of human behavior disappear. Linear though it is, even Kinsey’s scale has six gradations of sexual expression; and Kinsey understood the importance of the life cycle as a proper framework for analyzing human desire. Academics –be they biologists, social scientists,2 or cultural theorists–have become locked into an oppositional framework. As a result, they are asking the wrong questions
Boundary element method for analysis of holey optical fibers

By using a full-vector boundary element method (BEM) based on a formulation in terms of transverse magnetic field components, holey fibers (HFs) are numerically analyzed. The BEM provides very accurate solutions with an extremely small number of unknowns. Not only the characteristics of all-silica HFs, but also those of hole-assisted lightguide fibers and field-confined HFs, are investigated and compared with each other.
Distribution and origin of authigenic smectite clays in Cape Roberts Project Core 3, Victoria Land Basin, Antarctica

Of some 800 m of lower Oligocene marine sediments cored continuously from the seafloor in the Victoria Land Basin of Antarctica at Cape Roberts Site CRP-3, the lower 500 m exhibit authigenic smectite clay coats on shallow-water sandstone grains. A scanning electron microscope/EDS study of 46 fracture sections confirms that the distribution of the clay coats through the unit is not uniform or evenly distributed, but rather varies with depth, original porosity, and the kinds and abundance of source materials. Our results suggest that smectite emplacement resulted from in-situ, low-temperature burial diagenesis rather than hydrothermal or fault-focused thermobaric fluids.