cssi/SciSciGPT-SciSciNet huggingface dataset:
Calcium sparks in smooth muscle

Local intracellular Ca(2+) transients, termed Ca(2+) sparks, are caused by the coordinated opening of a cluster of ryanodine-sensitive Ca(2+) release channels in the sarcoplasmic reticulum of smooth muscle cells. Ca(2+) sparks are activated by Ca(2+) entry through dihydropyridine-sensitive voltage-dependent Ca(2+) channels, although the precise mechanisms of communication of Ca(2+) entry to Ca(2+) spark activation are not clear in smooth muscle. Ca(2+) sparks act as a positive-feedback element to increase smooth muscle contractility, directly by contributing to the global cytoplasmic Ca(2+) concentration ([Ca(2+)]) and indirectly by increasing Ca(2+) entry through membrane potential depolarization, caused by activation of Ca(2+) spark-activated Cl(-) channels. Ca(2+) sparks also have a profound negative-feedback effect on contractility by decreasing Ca(2+) entry through membrane potential hyperpolarization, caused by activation of large-conductance, Ca(2+)-sensitive K(+) channels. In this review, the roles of Ca(2+) sparks in positive- and negative-feedback regulation of smooth muscle function are explored. We also propose that frequency and amplitude modulation of Ca(2+) sparks by contractile and relaxant agents is an important mechanism to regulate smooth muscle function.
Lactation and weight retention

The effect of lactation on weight retention was investigated longitudinally, with data collected at 0.5, 2, 4, 6, 12, and 18 mo after parturition in 110 women aged 20-40 y who had been nulliparous or primiparous. At each evaluation women were categorized as fully breast-feeding, partly breast-feeding, or bottle-feeding including infants weaned to a bottle (bottle feeding/weaned). Postpartum weight retention was calculated by subtracting weight before pregnancy from weight at each evaluation. Lactation practices were found to be significantly associated (P < 0.05) with postpartum weight retention by longitudinal regression analysis. Women who bottle-fed their infants retained more weight over time than women who breast-fed their infants. Significantly slower rates of weight loss were observed when women ceased breast-feeding or switched from fully to partly breast-feeding. Weight retention over time was greater in women who were older, unmarried, or had greater weight gain during pregnancy (P < 0.05). A pattern of weight gain rather than weight loss was observed in unmarried women. Our findings suggest that lactation influences the pattern of postpartum weight retention; however, the effect of lactation on weight retention was sufficiently limited to warrant minimal emphasis on lactation as a means of minimizing postpartum weight retention.
Suspended sediment and carbonate transport in the Yukon River Basin, Alaska: Fluxes and potential future responses to climate change

[1] Loads and yields of suspended sediment and carbonate were measured and modeled at three locations on the Yukon, Tanana, and Porcupine Rivers in Alaska during water years 2001–2005 (1 October 2000 to 30 September 2005). Annual export of suspended sediment and carbonate upstream from the Yukon Delta averaged 68 Mt a−1 and 387 Gg a−1, respectively, with 50% of the suspended sediment load originating in the Tanana River Basin and 88% of the carbonate load originating in the White River Basin. About half the annual suspended sediment export occurred during spring, and half occurred during summer-autumn, with very little export in winter. On average, a minimum of 11 Mt a−1 of suspended sediment is deposited in floodplains between Eagle, Alaska, and Pilot Station, Alaska, on an annual basis, mostly in the Yukon Flats. There is about a 27% loss in the carbonate load between Eagle and Yukon River near Stevens Village, with an additional loss of about 29% between Stevens Village and Pilot Station, owing to a combination of deposition and dissolution. Comparison of current and historical suspended sediment loads for Tanana River suggests a possible link between suspended sediment yield and the Pacific decadal oscillation.
Monitoring oxygen levels in orthotopic human glioma xenograft following carbogen inhalation and chemotherapy by implantable resonator-based oximetry

Hypoxia is a critical hallmark of glioma, and significantly compromises treatment efficacy. Unfortunately, techniques for monitoring glioma pO2 to facilitate translational research are lacking. Furthermore, poor prognoses of patients with malignant glioma, in particular glioblastoma multiforme, warrant effective strategies that can inhibit hypoxia and improve treatment outcome. EPR oximetry using implantable resonators was implemented for monitoring pO2 in normal cerebral tissue and U251 glioma in mice. Breathing carbogen (95% O2 + 5% CO2) was tested for hyperoxia in the normal brain and glioma xenografts. A new strategy to inhibit glioma growth by rationally combining gemcitabine and MK-8776, a cell cycle checkpoint inhibitor, was also investigated. The mean pO2 of left and right hemisphere were approximately 56 – 69 mmHg in the normal cerebral tissue of mice. The mean baseline pO2 of U251 glioma on the first and fifth day of measurement was 21.9 ± 3.7 and 14.1 ± 2.4 mmHg, respectively. The mean brain pO2 including glioma increased by at least 100% on carbogen inhalation, although the response varied between the animals over days. Treatment with gemcitabine + MK-8776 significantly increased pO2 and inhibited glioma growth assessed by MRI. In conclusion, EPR oximetry with implantable resonators can be used to monitor the efficacy of carbogen inhalation and chemotherapy on orthotopic glioma in mice. The increase in glioma pO2 of mice breathing carbogen can be used to improve treatment outcome. The treatment with gemcitabine + MK-8776 is a promising strategy that warrants further investigation.
Desmopressin (DDAVP) acts on platelets to generate platelet microparticles and enhanced procoagulant activity

Desmopressin (DDAVP), an analog of vasopressin (AVP), has wide clinical application as an anti-hemorrhagic (AH) agent. DDAVP in vivo releases vWF from endothelial cells but is reported to have little action on platelets. However, DDAVP is often used to improve hemostasis in platelet dysfunctions. We examined the effect of DDAVP on platelet microparticle (PMP) formation and procoagulant activity in vitro using platelets from normal volunteers and in vivo in six patients receiving DDAVP therapy. In the former, platelets were incubated with DDAVP (0.5 to 25 nM) and PMP released were stained with FITC-labeled MAb alpha-GP IIb/IIIa for flow cytometry. Procoagulant activity was measured in a clot-based assay using Russel's viper venom (RVV) calibrated with cephalin. A mean increase of 2-3 fold was observed in both PMP and procoagulant activity. Parallel to these observations was a dose-dependent rise in organelle-associated Ca2+. The assays were also performed on six patients prior to and at one hour after infusion of DDAVP, and similar but lesser effects were observed. We conclude that DDAVP acts on platelets in vitro, and that these effects may contribute to the hemostatic action of DDAVP in platelet dysfunctions in vivo.
Estimating growth kinetics of Penicillium chrysogenum through the use of respirometry

The applicability of respirometry to characterize fungal growth kinetics was studied using Penicillium chrysogenum as the model microorganism. Oxygen uptake data were used in conjunction with a nonlinear parameter estimation technique to determine the kinetic parameters associated with microbial growth. The theoretical model that used the Contois equation for microbial growth was able to accurately describe experimental oxygen uptake data. Penicillium chrysogenum was characterized by average values of 0·195 h−1 and 4·13 for the maximum specific growth rate, μmax, and the Contois saturation coefficient, Kc, respectively. The average true growth yield was 0·405 mg mg−1. As only oxygen uptake information is required for biokinetic parameter estimation, respirometry is a very convenient tool for studying microbial growth as high quality experimental data can be obtained with relatively little experimental effort. © 1998 SCI
Time series analysis of morbidity data for assessment of acute environmental health effects

We present a method we developed to overcome some of the problems that are encountered in the attempts to identify acute health effects of environmental stimuli such as air pollution. To illustrate this method we have used daily records of asthmatic attacks in New York City. We also review some of the shortcomings of the presently used regression techniques, where a health variable is regressed on one or more environmental variables.
Human Exposure to PBDEs: Associations of PBDE Body Burdens with Food Consumption and House Dust Concentrations

This study was designed to determine the body burden of polybrominated diphenyl ethers (PBDEs) among first-time mothers in the Greater Boston, Massachusetts area and to explore key routes of exposure. We collected breast milk samples from 46 first-time mothers, 2-8 weeks after birth. We also sampled house dust from the homes of a subset of participants by vacuuming commonly used areas. Data on personal characteristics, diet, home furniture, and electrical devices were gathered from each participant using a questionnaire. Breast milk and dust samples were analyzed for PBDEs using gas chromatography/ mass spectrometry. PBDE concentrations were log-normally distributed in breast milk and dust. We found statistically significant, positive associations between PBDE concentrations in breast milk and house dust (r = 0.76, p = 0.003, not including BDE-209), as well as with reported dietary habits, particularly the consumption of dairy products (r = 0.41, p = 0.005) and meat (r = 0.37, p = 0.01). Due to low detection rates, it was not possible to draw conclusions about the association between BDE-209 in milk and dust. Our results support the hypothesis that the indoor environment and diet both play prominent roles in adult human exposure to PBDEs.
Near-field measurements of optical channel waveguides

Near field microscopy has been used to investigate the guided mode intensity distribution in a variety of optical channel waveguide structures. We have studied the optical field intensity distribution in channel waveguides, directional couplers, and Y-branches above the surface of the structures scanning transverse to the waveguide propagation direction. Single mode channel waveguides are formed by etching a ridge in Si3N4/SiO2 structures and excited at a wavelength of 833 nm. Measurements of the intensity distribution transverse to a channel waveguide reveal a cosine squared variation of intensity above the ridge region and an exponential decay away from the ridge region, in agreement with theoretical expectations. For more complicated structures, for instance the directional coupler, measurements along the two waveguides of the coupler provide a detailed view of optical power transfer from one waveguide to the other. Measurements also provide a detailed view of the evolution of the optical power in the Y-junction.© (1995) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Charge exchange ρ 0 π + photoproduction and implications for searches for exotic mesons

We analyze the processes $\stackrel{\ensuremath{\rightarrow}}{\ensuremath{\gamma}}+\stackrel{\ensuremath{\rightarrow}}{p}{\ensuremath{\rho}}^{0}{\ensuremath{\pi}}^{+}n$ at low momentum transfer focusing on the possibility of the production of an exotic ${J}^{\mathrm{PC}}{=1}^{\ensuremath{-}+}$ meson state. In particular we discuss polarization observables and conclude that linear photon polarization is instrumental for separating the exotic wave.
Explaining Populist Party Adaptation in Latin America Environmental and Organizational Determinants of Party Change in Argentina, Mexico, Peru, and Venezuela

This article uses a two-level framework to explain variation in Latin American populist parties' responses to the neoliberal challenge of the 1980s and 1990s. First, it examines the incentives for ...
Progressive recovery of learning during regeneration of a single synapse in the medicinal leech.

The leech escape reflex—shortening of the body—can change with nonassociative conditioning, including sensitization, habituation, and dishabituation. Capacity for sensitization, which is an enhancement of the reflex, is lost when a single S-interneuron is ablated, but the reflex response itself remains. In the present experiments, the S-interneuron's axon in the living leech was filled with 6-carboxyfluorescein (6-CF) dye and cut with an argon laser microbeam (λ = 488 nm). In contrast to sham-operated animals, axotomized preparations did not sensitize, reflecting the key role of the S-cell. By 2 weeks or more, S-cell axons had regenerated and reestablished synapses at their usual locations with neighboring S-cells. By 4 weeks, this restored the ability to sensitize to a level indistinguishable from that of controls, but an intermediate state of recovery was seen from 2–3 weeks after injury—a period not previously examined. The small capacity for sensitization among newly regenerated preparations was significantly lower than in sham controls but appeared higher than in animals whose cut S-cell axon had not regenerated its synapse. The results confirm the crucial role of the S-cell in sensitization. Moreover, full sensitization does not occur immediately upon synapse regeneration. J. Comp. Neurol. 457:67–74, 2003. © 2003 Wiley-Liss, Inc.
Knowledge flow with information assurance track

A master program at KSU was started three years ago, and one of the tracks, which has been offered now for a year is "Information Assurance". The major problem with the courses in this track is there is a weakness in the flow of information and knowledge delivery comparing with other universities (with longer experiences). This paper, therefore, looks at the existing knowledge flow, extracting the weaknesses and suggesting a better knowledge flow to enhance the curriculum and student performance. This paper will also justify the change need to be made and look at advance levels of education, such as a Ph.D. in information security.
The Effect of Chronic Atropine Treatment on Salivary Composition and Caries in Rats

Many instances of salivary dysfunction in humans can be traced to the use of medications that have hyposalivary side-effects. In this study, atropine, a cholinergic antagonist, was administered chronically to rats by use of osmotic mini-pumps. Steady-state blood levels, similar to levels obtained in human multiple oral dosing, were thus maintained. Atropine delivered in this manner for 24 days was found to decrease protein concentration of parotid saliva (p less than 0.05) elicited by pilocarpine, and to increase smooth-surface caries scores (p less than 0.05) in rats fed a cariogenic diet. Parotid saliva collected via ductal cannulation from rats subjected to chronic atropine administration (and stimulated to secrete by pilocarpine) exhibited increased levels of two basic proline-rich proteins (Peak A and SP-3), as evaluated by SDS-PAGE, compared with those observed in saliva from controls. Cannulation of sublingual glands in animals receiving high doses of atropine produced no measurable secretion upon pilocarpine stimulation. Carbachol stimulation of dispersed cell aggregates of sublingual glands from sham-operated and high-dose atropine groups indicated that the glands responded similarly once the antagonist was washed from the system, implying that the lack of secretion in vivo was caused by antagonism of the cholinergic receptor by atropine. Our observations suggest that this model system can be exploited for determination of the effects of chronic administration of hyposalivary drugs on salivary composition and caries rates.
Vesicular stomatitis epidemic in colorado: Clinical observations and financial losses reported by dairymen

Abstract The financial impact and clinical expression of vesicular stomatitis in Colorado dairy herds was studied during the 1982 epidemic. A non-random sample of 15 dairy herds was surveyed, 13 of which had clinical cases in lactating cows. These 13 herds represented 2404 cows among which were 378 clinical cases. The dairymen reported a distribution of lesions among the cases as follows: 262 (69.3%) oral only; 87 (23.0%) teat only; 22 (5.8%) both oral and teat and 7 (1.9%) with foot lesions. Herds experiencing primarily oral lesions had an attack rate of 19.8% with an average clinical course of 23.8 days. The attack rate in 2 of the 4 herds with teat lesions was 55.8% and 1.6% in the other 2 herds. Mastitis complicated 72% of the cases with teat lesions. The direct costs resulting from 378 cases of vesticular stomatitis reported by 13 dairymen totaled $95 752, which is an average cost of $253.31 per clinical case. The average cost per case with oral lesions is estimated to be $174.06 in contrast to $568.22 average for cases with teat lesions. The greatest loss was due to cows culled, 36.6% of the total direct costs. Decreased milk production was second with 30.3% of the total.The average decrease in milk production per clinical case was 261.3 kg (576 lbs). Deaths accounted for 11.3% of the loss and the combined costs of drugs, extra labour, veterinary service, weight loss and extra ectoparasite control accounted for 11.9% of the $95 752 total.
Parathyroid hormone stimulates growth of embryonic chick pelvic cartilage in vitro.

Addition of N6-monobutyryl cyclic AMP (BtcAMP) or methylisobutylxanthine to embryonic chick pelvic cartilages incubated in a serum-free medium for 3 days stimulates the cartilages to grow predominately through increasing cellular hyperplasia [1]. The present study investigated whether parathyroid hormone (PTH) added to the serum-free organ culture system would mimic the growth-promoting effects of BtcAMP through increasing endogenous cartilage cyclic AMP content. Parathyroid hormone 10 nM stimulatesin vitro pelvic cartilage growth as compared with cartilage grown in medium alone, as estimated by increases in wet weight (64%), dry weight (91%), total soluble protein (19%), and deoxyribo-nucleic acid (DNA) content (51%). Parathyroid hormone (0.1–10nM) in a concentration-dependent manner produces increases in wet weight and radiolabeled precursor incorporation of [3H]thymidine and [14C]-L-leucine over cartilage incubated in medium alone. Both PTH-treated and BtcAMP-treated cartilage show histological changes of increased cellularity as well as raised DNA content and elevated DNA/protein ratios. PTH increases cartilage cyclic AMP content, with the maximum rise occurring after 30 min incubation, and a return to levels found in pelvic cartilages incubated in medium alone by 4 hours. Consequently, cartilages incubated in medium containing PTH for 4 hours and then incubated in medium alone for the remaining 3 days, grew as well as cartilages that had been incubated in medium containing PTH for the entire 72-hour period. Thus, PTH, by raising intracellular cyclic AMP, triggers cartilage growthin vitro.
Genome-wide analysis and expression profiling of the small heat shock proteins in zebrafish.

Small Heat Shock Proteins (sHSPs) have important roles in preventing disease and promoting resistance to environmental stressors. Mutations in any one of a number of sHSPs, including HSP27 (HSPB1), HSP22 (HSPB8), αA-crystallin (HSPB4), or αB-crystallin (HSPB5) can result in neuronal degeneration, myopathy, and/or cataract in humans. Ten sHSPs are known in humans, and thirteen have been identified in teleost fish. Here we report the identification of thirteen zebrafish sHSPs. Using a combination of phylogenetic analysis and analysis of synteny, we have determined that ten are likely orthologs of human sHSPs. We have used quantitative RT-PCR to determine the relative expression levels of all thirteen sHSPs during development and in response to heat shock. Our findings indicate that most of the zebrafish sHSPs are expressed during development, and five of these genes are transcriptionally upregulated by heat shock at one or more stages of development.
Viscoelastic properties of polyamic acid solutions—precursors of polyimides

The rheology of polyamic acid (PAA) solutions, precursors of polyimides used in microelectronic device applications, has been investigated by dynamic (oscillatory) shear flow measurements. Frequency dependent storage and loss moduli and dynamic viscosity were measured in the frequency range 10−1 to 103 rad/s at 23°C. The storage modulus G′ (ω) and loss modulus G″ (ω) exhibited quadratic and linear dependence in frequency at low frequencies respectively, the viscoelastic fluid behavior commonly predicted for polymer solutions from many molecular theories. At high frequencies both dynamic moduli become proportional to ω2/3. The results show that PAA solutions are very high loss viscoelastic fluids, judging from the loss tangent values which far exceed unity. It is suggested that dynamic viscoelastic properties could be used to monitor the degree of imidization since there is a gradual change from viscoelastic fluids to soft viscoelastic solids to hard viscoelastic solids as PAA is converted to polyimides. Onset of non-Newtonian flow as shown on the frequency dependent dynamic viscosity was in the range 30 to 200 rad/s. The viscoelastic constants, zero-shear rate viscosity ηo and steady-state compliance Je0, where also determined from the dynamic data and compared to previous steady shear flow results.
On Scroll-Making in Ancient Jerusalem

This paper, read to an Association of Bible collectors, considers the way in which a small scroll-making community constituted by a prophet, scribes, and political operators formed a community with an alternative vision of social reality in opposition to the dominant vision and the dominant power structure of ancient Jerusalem. It is proposed that this oppositional community that produced its subversive scroll began the scroll movement that eventuated in "canon," a text production that was characteristically subversive of established social vision.
Reproductive memory for diagonal and nondiagonal patterns in chimpanzees

Two male juvenile chimpanzees were trained to reproduce from memory geometric patterns composed of lighted cells in a 3 x 3 matrix. In Experiment I, subjects reproduced 3-cell horizontal, vertical and diagonal patterns with either 0- or 5-second delay between stimulus offset and response. Diagonals were more difficult and were more affected by delay than were nondiagonal patterns. The sequence of response to diagonals was less structured than to nondiagonals. In Experiment II, more complex 4-cell patterns were used and, following training, subjects were tested for transfer to new patterns. Again, diagonals were more difficult to reproduce than nondiagonals. Transfer of training to new patterns requiring different motoric responses was successful. Similar to Experiment I, organization of responding was greater for nondiagonals than for diagonals. These results are discussed with regard to the presence of internal representation of visual information in nonhuman primates.
Evaluating Capacity to Live Independently and Safely in the Community: Performance Assessment of Self-Care Skills

To determine clients' capacity for community living, occupational therapists must use measures that capture the person-task-environment transaction and compare clients' task performance to a performance standard. The Performance Assessment of Self-care Skills, a performance-based, criterion-referenced, observational tool, fulfills this purpose. In this practice analysis, using data from this tool from multiple clinical studies (N = 941), the authors describe tasks that clients from various diagnostic populations could and could not perform independently and safely. For clinicians, the Performance Assessment of Self-care Skills can be used to identify which daily tasks are compromised and the point of task breakdown, as well as to provide guidance about potential interventions.
Symmetries and states of Ps2

Abstract The particle interchange symmetry and spin problem for Ps 2 are worked out for the ground and singly excited states of zero orbital angular momentum. The general form of the wave function for each state is given, parities for inversion and charge conjugation are deduced, and annihilation rates are discussed.
Spaced serial section analysis of the avian muscle spindle

Muscle spindle ultrastructure of the extensor digitorum communis of pigeons was studied using spaced serial sections. The intrafusal fibers extended well beyond the ensheathing capsule, after which they became disoriented and often fused with each other before terminating on the connective tissue of extrafusal fibers. Several extracapsular fibers contained macrofibrils which were about 0.1 μm in diameter and contained several dozen smaller (10 nm) subunits. Intrafusal fibers commonly formed close attachments with one another for short or extended (240 μm) lengths. A basal lamina was absent between regions of pairing, and a myosatellite cell lay at the border of the coupled region. Several fibers could be coupled together in a single cross section; fibers coupled together, separated, and either recoupled or became associated with other fibers along the length of a spindle. Profiles of sensory terminals and sensory satellite cells alternated to form a smooth-contoured surface over most of the fiber cross section in the equatorial region. The sensory terminals contained many mitochondria, lysosomes, and clear and dense core microvesicles. Both the terminals and sensory satellite cells formed desmosomelike junctions with the intrafusal fiber. A crescentic collagen sheath covered that portion of the fiber cross section containing the sensory terminal-satellite cell complex. Inner capsule cells surrounded the entire assembly in the equatorial region. The basal lamina thicknesses differed over the naked intrafusal fiber compared to that portion covered by the sensory terminal or sensory satellite cell. The thickness was more than doubled over the latter regions, indicating that the basal lamina over these areas was a product of the fused intrafusal fiber and sensory terminal and/or sensory satellite cell basal laminae. These are discussed in terms of intrafusal fiber degeneration and regeneration.
Some carbonyl compounds and free fatty acid composition of Afyon Kaymagı (clotted cream) and their effects on aroma and flavor

Some carbonyl compounds (acetaldeyhde, acetone, butanone-2 and diacetyl), the lactic acid and free fatty acid compositions of Afyon kaymagi, produced from pure buffalo milk obtained from seven different farms, and their effects on aroma and flavor were investigated. Acetone was found in the highest amount of carbonyl compounds. Butyric, stearic, oleic, linoleic and linolenic acids were characteristic free fatty acids for Afyon Kaymagi. The effect of the investigated compounds on the aroma and flavor scores (AFS) of Afyon Kaymagi was found to be 93.3%. Lactic acid was negatively correlated but was the second most important compound for the aroma and flavor of Afyon Kaymagi (R 2 = 40%). The investigated carbonyl compounds explained only 3.2% of the variation in aroma and flavor of Afyon Kaymagi. Lactic acid, acetone, diacetyl, C 4:0 , C 8:0 , C 12:0 and C 18:0 had negative effects on the AFS, but acetaldehyde, butanone-2, C 6:0 , C 10:0 , C 14:0 , C 16:0 , C 18:1 , C 18:2 and C 18:3 were positively related to the AFS.
Adaptive algebraic smoothers

This paper will present a new method of adaptively constructing block iterative methods based on Local Sensitivity Analysis (LSA). The method can be used in the context of geometric and algebraic multigrid methods for constructing smoothers, and in the context of Krylov methods for constructing block preconditioners. It is suitable for both constant and variable coefficient problems. Furthermore, the method can be applied to systems arising from both scalar and coupled system partial differential equations (PDEs), as well as linear systems that do not arise from PDEs. The simplicity of the method will allow it to be easily incorporated into existing multigrid and Krylov solvers while providing a powerful tool for adaptively constructing methods tuned to a problem.
The Balassa-Samuelson Model: an Overview*

This paper introduces a special issue marking the thirtieth anniversary of the publication of two classic papers in international economics, Balassa (1964) and Samuelson (1964). We provide a brief analytical treatment of the basic model and an overview of the contributions in this special issue. the special issue includes novel empirical and theoretical approaches related to the Balassa-Samuelson model. Theoretical models include dynamic two-sector growth models, two-country general-equilibrium models, and openeconomy models with imperfectly competitive nontraded-goods sectors. Several papers exploit new sources of data or datasets constructed in new ways from traditional sources. “Under the skin of any international economist lies a deep-seated belief in some variant of the PPP theory of exchange rates.” (Rudiger Dornbusch and Paul Krugman, 1976, p. 540)
Analytical radiography for planar radiographic images implemented with a multi-modal system

A radiographic system is optimized for the contrast inherent to small animals and is developed for a multi-modal imaging system devised for in-vivo studies. The range of X-ray energies utilized (generally considered ''soft X-rays'') enables enhanced spatial resolution and superior contrast for detailed study of the mouse anatomy and smaller specimens. Despite the difficulties presented by the complicated energy spectrum of soft X-rays, relevant system calibrations for bone measures are described in detail and applied to the mouse. Further, long-bone symmetry modeling using a cylindrical projection is applied to the planar density image, providing convenient bone density estimates that are consistent with other methodologies.
Functional redundancy of octamer elements in the mouse mammary tumor virus promoter

The promoter of mouse mammary tumor virus contains three overlapping sequence elements related to the octamer consensus (ATGCAAAT) that are largely contained within two 10 bp direct repeats (CTTATGTAAA) separated by a 2 bp spacer between 60 and 39 relative to the start of transcription. Gel electrophoresis mobility shift competition assays demonstrate that the most distal of these octamer-related elements is recognized by a protein that also binds to the most proximal element, while the central octamer-related element is not efficiently recognized. Transient transfection assays with altered promoters reveal that the portion of the 10 bp repeat that is not related to the octamer consensus appears not to be important for transcription. The distal and proximal octamer-related elements are, at least to some extent, functionally redundant. Complete deletion of one element has little or no effect on promoter activity so long as certain spacing constraints among remaining promoter elements are maintained. Systematic variation of such spacing reveals a cyclic effect on promoter activity corresponding to the periodicity of Bform DNA, suggesting functional interactions between proteins bound to adjacent sites.
On the state of Egypt: what made the revolution inevitable

On the state of Egypt: what made the revolution inevitable, by Alaa Al Aswany, New York, Vintage, 2011, 208 pp., £7.90 (paperback), ISBN 978-0-30794698-0 Alaa Al Aswany's newly published collection...
Self-assembled FUS binds active chromatin and regulates gene transcription

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease. Fused in sarcoma (FUS) is a DNA/RNA binding protein and mutations in FUS cause a subset of familial ALS. Most ALS mutations are clustered in the C-terminal nuclear localization sequence of FUS and consequently lead to the accumulation of protein inclusions in the cytoplasm. It remains debatable whether loss of FUS normal function in the nucleus or gain of toxic function in the cytoplasm plays a more critical role in the ALS etiology. Moreover, the physiological function of FUS in the nucleus remains to be fully understood. In this study, we found that a significant portion of nuclear FUS was bound to active chromatin and that the ALS mutations dramatically decreased FUS chromatin binding ability. Functionally, the chromatin binding is required for FUS transcription activation, but not for alternative splicing regulation. The N-terminal QGSY (glutamine-glycine-serine-tyrosine)-rich region (amino acids 1–164) mediates FUS self-assembly in the nucleus of mammalian cells and the self-assembly is essential for its chromatin binding and transcription activation. In addition, RNA binding is also required for FUS self-assembly and chromatin binding. Together, our results suggest a functional assembly of FUS in the nucleus under physiological conditions, which is different from the cytoplasmic inclusions. The ALS mutations can cause loss of function in the nucleus by disrupting this assembly and chromatin binding.
Methyl palmitate: Inhibitor of phagocytosis in primary rat Kupffer cells

Abstract Kupffer cells are involved in phagocytosis and known to release biologically active mediators during early events of liver injury. Such functional properties of Kupffer cells can be modulated by methyl palmitate (MP). Therefore, efficacy of MP to modulate Kupffer cell function was evaluated in cultured primary Kupffer cells from rat liver. Phagocytic activity of Kupffer cells was measured by their capacity to phagocytize latex beads and the release of TNF-α, IL-10, IL-6, nitric oxide, and PGE2 was determined in cell culture medium after incubating the cells with various concentrations of MP for 24 h followed stimulation with lipopolysaccharide (LPS) for 6 h. To understand the mechanism of phagocytosis, we investigated the hydrolysis of MP, and determine ATP levels and activity of NF-κB in MP-inhibited Kupffer cells. A significant decrease was observed in phagocytosis. Phagocytosis evaluated at 0.5 mM MP was found to be time-dependent with a maximum decrease of 49% at 6 h. Exposure of Kupffer cells to MP followed by LPS stimulation showed a dose-dependent decrease in phagocytosis and reduced the release of TNF-α, IL-10, nitric oxide, and PGE2 but not of IL-6 levels in the supernatant as compared to the control. While ATP levels were unchanged, the nuclear factor NF-κB (p65) activity was inhibited in Kupffer cells treated with MP after LPS stimulation (35.6 RLU versus 49.6 RLU in control). Hydrolysis of MP was found to be time-dependent; maximum concentration of MP and palmitic acid (hydrolysis products) in the cell being at 3 and 6 h, respectively. In general, MP appears to reduce phagocytosis and levels of TNF-α, IL-10, nitric oxide, and PGE2 without affecting ATP levels and is probably mediated by NF-κB. This in vitro model is useful for detailed mechanistic studies of inhibition of phagocytosis by MP and other fatty acid esters.
Turbulent sediment transport using momentum balance — The strong turbulence approximation

The turbulent flow of a sediment-fluid mixture near a flat bottom is studied. An equation is derived expressing the balance between the gravitational force on the sediment and the turbulent sediment momentum flux. A mixing length theory is used to model the turbulent momentum flux, with the mixing lengths assumed proportional to the distance from the bottom. The ratio of the sediment momentum mixing length to the mixture momentum mixing length is assumed to be a universal constant. An approximate solution for the mean sediment flux profile is derived for situations where the turbulent strength near the bottom dominates the gravitational effects there. The resulting concentration profile is constant near the bottom and drops off rapidly above a certain predicted depth.
Regulation of chromosome replication in Escherichia coli: Alternate replication of two chromosomes at slow growth rates

Escherichia coli 15 T − , arginine − , methionine − , tryptophan − , grows exponentially with a 40-minute generation period in M9-glucose medium and a 70-minute generation period in M9-succinate medium. The DNA content per cell in these two media is 8·4 and 7·0 × 10 9 daltons, respectively, corresponding to about two chromosomes per cell. Autoradiographic studies demonstrate that, at any instant, cells in glucose cultures are synthesizing about twice as many conserved DNA units as cells in succinate cultures. When starved of amino acids, cells growing in glucose synthesize about 2·5 times as much DNA as cells growing in succinate. Experiments combining a density and a radioactive label demonstrated that in succinate the two chromosomes per cell are synthesized alternately and in sequence. In the absence of amino acids, replication of one chromosome is completed. Replication of the second is initiated upon re-addition of amino acids. Thymine starvation initiates replication prematurely on only those chromosomes which are already in the process of replication. A model for alternate chromosome replication is discussed.
Abstract 1933: Ellagic acid induces apoptosis and cell cycle arrest in HeLa cells and inhibits HPV oncogene expression

Proceedings: AACR 103rd Annual Meeting 2012‐‐ Mar 31‐Apr 4, 2012; Chicago, IL Ellagic Acid is a naturally occurring compound that demonstrated anti cancer activity in vitro and in vivo. Ellagic acid inhibits protein kinase CK2, which has been identified as a promoter of tumorogenesis. Blocking CK2 activity can reactivate dormant cellular defensive mechanism and further block signaling pathways that induce cancer. In this study, we are testing HPV 18 positive cervical cancer cells (HeLa) to investigate the effect of ellagic acid on CK2 kinase activity, HPV oncogenes E6 and E7 expression and downstream targets leading to cell death in vitro and in vivo. Treating HeLa cells with ellagic acid induced in vitro cell cycle arrest and caspase mediated apoptosis in both time and dose dependent manner. Ellagic acid inhibited CK2 phosphorylation activity, as well as the expression of viral oncogenes E6 and E7. Inhibition of HPV oncogene expression was accompanied by an increase in P53 and a decrease in cyclin A expression. Ellagic acid treatment induced cytochrome c release in the cytosol and subsequent activation of caspase 3, which led to the fragmentation of Poly (ADP) RibosePolymerase (PARP) at the end of the caspase cascade. Finally, mice treated with ellagic acid demonstrated inhibition of cervical cancer xenograft growth and longer survival compared to vehicle-treated mice confirming the potent anti-tumor activity of ellagic acid. Our results suggest that ellagic acid has anti-tumor and anti-viral properties which could make it suitable for the prevention of HPV induced cervical carcinoma. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1933. doi:1538-7445.AM2012-1933
El concurso del Faro de Colón: Un reencuentro con el monumento olvidado de la arquitectura panamericana

The vision of Pan-Americanism as a expression of the unity of America is peoples inspired one of the most singular competitions in the history of the hemisph...
PRC2 binds active promoters and contacts nascent RNAs in embryonic stem cells

Polycomb repressive complex 2 (PRC2) acts as an epigenetic repressor by depositing repressive H3K27me3 marks, but how it is regulated and directed to specific genes remains unknown. PRC2 is now found to bind at low levels to many gene promoters, including active ones devoid of H3K27me3, and the EZH2 catalytic subunit binds directly to nascent transcripts.
Observations concerning topology and locations of helix ends of membrane proteins of known structure.

Hydropathy plots of amino acid sequences reveal the approximate locations of the transbilayer helices of membrane proteins of known structure and are thus used to predict the helices of proteins of unknown structure. Because the three-dimensional structures of membrane proteins are difficult to obtain, it is important to be able to extract as much information as possible from hydropathy plots. We describe an “augmented” hydropathy plot analysis of the three membrane proteins of known structure, which should be useful for the systematic examination and comparison of membrane proteins of unknown structure. The sliding-window analysis utilizes the floating interfacial hydrophobicity scale [IFH(h)] of Jacobs and White (Jacobs, R.E., White, S.H., 1989. Biochemistry 28:3421–3437) and the reverse-turn (RT) frequencies of Levitt (Levitt, M., 1977, Biochemistry 17:4277–4285). The IFH(h) scale allows one to examine the consequences of different assumptions about the average hydrogen bond status (h=0 to 1) of polar side chains. Hydrophobicity plots of the three proteins show that (i) the intracellular helix-connecting links and chain ends can be distinguished from the extracellular ones and (ii) the main peaks of hydrophobicity are bounded by minor ones which bracket the helix ends. RT frequency plots show that (iii) the centers of helices are usually very close to wide-window minima of average RT frequency and (iv) helices are always bounded by narrow window maxima of average RT frequency. The analysis suggests that side-chain hydrogen bonding with membrane components during folding may play a key role in insertion.
Spinal immobilization on a flat backboard: does it result in neutral position of the cervical spine?

Study objectives: To determine the amount of occipital padding required to achieve neutral position of the cervical spine when a patient is immobilized on a fiat backboard. Neutral position was defined as the normal anatomic position of the head and torso that one assumes when standing looking straight ahead. Design: Descriptive with hypothesis testing of selected descriptive elements. Setting: University campus and hospital. Subjects: One hundred healthy young adults with no history of back disease. Interventions: Volunteers were measured in standing and supine positions. Measurements: Occipital offset; height; weight; and head, neck, and chest circumferences were measured for each subject. Main results: The amount of occipital offset required to achieve neutral position varied from 0 to 3.75 in. (mean, 1.5 in.). Mean occipital offset for men (1.67 in.) was significantly greater than that for women (1.31 in.) Easily obtained body measurements did not accurately predict occipital offset. Conclusion: Immobilization on a fiat backboard would place 98% of our study subjects in relative cervical extension. Occipital padding would place a greater percentage of patients in neutral position and increase patient comfort during transport. [Schriger DL, Larmon B, LeGassick T, Blinman T: Spinal immobilization on a fiat backboard: Does it result in neutral position of the cervical spine? Ann Emerg Med August 1991;20: 878-881.]
Synthesis and SAR studies of 1,4-benzoxazine MenB inhibitors: Novel antibacterial agents against Mycobacterium tuberculosis

Abstract Menaquinone is an essential component of the electron transport chain in many pathogens and consequently enzymes in the menaquinone biosynthesis pathway are potential drug targets for the development of novel antibacterial agents. In order to identify leads that target MenB, the 1,4-dihydroxy-2-naphthoyl-CoA synthase from Mycobacterium tuberculosis, a high-throughput screen was performed. Several 1,4-benzoxazines were identified in this screen and subsequent SAR studies resulted in the discovery of compounds with excellent antibacterial activity against M. tuberculosis H37Rv with MIC values as low as 0.6 μg/ml. The 1,4-benzoxazine scaffold is thus a promising foundation for the development of antitubercular agents.
Fertility-mortality variations across LDCs: women's education, labor force participation, and contraceptive-use.

UN and World Bank data on developing countries were used to examine variations across countries in child mortality and fertility patterns and to determine the impact of literacy and schooling labor force participation of women contraceptive use availability of health services and households headed by women on fertility rates and child mortality. The Schultz-Becker theoretical framework formed the basis of the analysis with ordinary least squares methods and extreme bounds analysis (EBA) used to test for robustness. The findings were that fertility was decreased due to womens human capital womens labor force participation and married womens use of contraception. The most powerful effect on fertility was contraceptive use followed by womens labor force participation. Without contraceptive use in the model womens literacy and school enrollments were negative and statistically significant. 66-81% of the variation in fertility rates was explained. EBA results showed the main variables as stable and consistent and consequently robust. Child mortality was strongly affected by womens schooling and labor force participation. Child mortality was negatively affected by availability of trained health services personnel at birth. Households headed by women had higher child mortality but the association was weak. The main variables explained 84-89% of the variation in child mortality and EBA results confirmed robustness. Socioeconomic improvement without attention to the health and educational needs of women would be counterproductive. Unfortunately the structural adjustment program has resulted in the decline in health and educational services in developing countries which severely affects low income women and households headed by women.
Effect of production site and storage on antioxidant levels in specialty potato (Solanum tuberosum L.) tubers

BACKGROUND: The potato can make a significant contribution of antioxidants to the human diet. In this study, antioxidant levels in tubers of 14 specialty potato clones grown at four production sites (two conventional, two organic), both fresh and stored, were examined across 2 years. RESULTS: Antioxidant activity of fresh tubers at all locations was higher in 2006 than in 2005. Cooler late-season temperatures in 2006 may have been responsible for the increased levels of antioxidants. Stored tubers had higher levels of antioxidant activity than fresh tubers, with a larger storage effect in 2005, when antioxidant levels in fresh tubers were lower. There was no consistent effect of production system (organic versus conventional) on antioxidant activity in tubers. CONCLUSION: For the specialty potato clones we evaluated, antioxidant levels were generally highest in potatoes grown in high-yielding production environments, and they increased during storage. Therefore, potatoes with high nutritional value, in terms of antioxidant activity, can be produced using conventional production and storage systems. Copyright © 2008 Society of Chemical Industry