cssi/SciSciGPT-SciSciNet huggingface dataset:
Intracellular Transport of Low Density Lipoprotein Derived Free Cholesterol Begins at Clathrin-Coated Pits and Terminates at Cell Surface Caveolae†

Free cholesterol (FC) is selectively internalized from low-density lipoprotein (LDL) by confluent fibroblast monolayers (Fielding & Fielding (1995) Biochemistry 34, 14237-14244). The kinetics of transport of LDL-derived 3H-FC within the cell were studied by density-gradient ultracentrifugal fractionation and in terms of the effects of inhibitors of endocytosis and intracellular transport. By these criteria, the initial uptake of LDL-FC was mediated by the cell-surface clathrin-coated pits. FC label then appeared in clathrin-coated dense vesicles. Uncoating of clathrin from these vesicles led to the appearance of label in a light density fraction and, subsequently, in an intermediate density fraction coincident with protein markers of the trans-Golgi network in these cells. 3H-FC was finally transported to the plasma membrane via a temperature-sensitive, probably microtubule-dependent pathway. These data are consistent with a role for the trans-Golgi network as an intermediate compartment in intracellular FC transport. They provide further evidence of a role for cell-surface caveolae in FC efflux.
Usefulness of nifedipine for myocardial ischemia and the nifedipine gastrointestinal therapeutic system.

Abstract Although conventional treatment of angina pectoris with nifedipine capsules involves frequent daily dosing, a new vehicle for the once-daily delivery of this potent but insoluble calcium channel blocking agent has been developed. With the gastrointestinal therapeutic system (GITS) formulation, constant effective drug levels of nifedipine are delivered for a full 24-hour period. When nifedipine GITS 30, 60 or 90 mg was administered once daily to patients with stable angina pectoris taking β blockers, clinical effectiveness was demonstrated both by an increase in time to angina and by exercise time compared with placebo. Improvement was noted to be more significant with the higher doses of nifedipine administered once daily. This study indicates that nifedipine GITS provides additional antianginal protection in patients with exercise-induced angina secondary to coronary artery disease who are receiving a fixed dose of β blocker.
Noise analysis for complex field estimation using a self-referencing interferometer wave front sensor

A noise analysis is presented for complex field estimation using a self-referencing interferometer wave front sensor with an amplified reference. The wave front sensor is constructed from a phase-shifting, point diffraction interferometer. The reference field is created by coupling a part of the incident wave front into a single mode fiber where it is optically amplified. The noise characteristics of this wave front sensor are examined in terms of the field estimation Strehl. The effects of several system parameters are examined\nobreak—shot noise, read noise, quantization noise, spontaneous emission from the amplifier, the relative intensities of the signal and reference fields, and temporal phase shifting.
Dynamic Response of a Supported Beam to Oscillatory Moving Masses

The dynamic response of an elastically supported infinite beam to oscillatory moving masses has been investigated. The moving velocity and distance between the masses was assumed to be constant. Th...
Stellar occultation experiment with the CASSINI VIMS instrument

The VIMS instrument (Visible and Infrared Mapping Spectrometer) will be flown in the late 1990s on the CASSINI mission to Saturn and its moons. VIMS is designed to generate two-dimensional multispectral images of planetary surfaces and their features in the visible and infrared spectra. Compared to earth-based instruments, the stellar occultation experiment will provide unprecedented thickness resolution and chemical composition of planetary atmospheres. It will also gather high SNR optical depth profiles and particle size distribution of the Saturnian rings. The stellar occultation mode ideally requires continuous data acquisition for periods of up to several hours as the instrument stares at a star. This presents a sizeable challenge to the instrument's operational mode: processes that normally occur during mirror retrace must be shifted to data acquisition cycles, thereby creating timing difficulties in the sequencing of these cycles. The presentation focuses on the analysis of the stellar occultation mode and presents solutions to the challenge of an uninterrupted data stream. Several options will be presented that minimize any possible degradation of the experiment's science content.
A numerical comparison of spherical, spheroidal and ellipsoidal harmonic gravitational field models for small non-spherical bodies: examples for the Martian moons

We present a comprehensive numerical analysis of spherical, spheroidal, and ellipsoidal harmonic series for gravitational field modeling near small moderately irregular bodies, such as the Martian moons. The comparison of model performances for these bodies is less intuitive and distinct than for a highly irregular object, such as Eros. The harmonic series models are each associated with a distinct surface, i.e., the Brillouin sphere, spheroid, or ellipsoid, which separates the regions of convergence and possible divergence for the parent infinite series. In their convergence regions, the models are subject only to omission errors representing the residual field variations not accounted for by the finite degree expansions. In the regions inside their respective Brillouin surfaces, the models are susceptible to amplification of omission errors and possible divergence effects, where the latter can be discerned if the error increases with an increase in the maximum degree of the model. We test the harmonic series models on the Martian moons, Phobos and Deimos, with moderate oblateness of $$<$$ 0.4. The possible divergence effects and amplified omission errors of the models are illustrated and quantified. The three models yield consistent results on a bounding sphere of Phobos in their common convergence region, with relative errors in potential of $$\sim $$ 0.01 and $$\sim $$ 0.001 % for expansions up to degree 10 and degree 20 respectively. On the surface of Phobos, the spherical and spheroidal models up to degree 10 both have maximum relative errors of $$\sim $$ 1 % in potential and $$\sim $$ 100 % in acceleration due ostensibly to divergence effect. Their performances deteriorate more severely on the more irregular Deimos. The ellipsoidal model exhibits much less distinct divergence behavior and proves more reliable in modeling both potential and acceleration, with respective maximum relative errors of $$\sim $$ 1 and $$\sim $$ 10 %, on both bodies. Our results show that for the Martian moons and other such moderately irregular bodies, the ellipsoidal harmonic series should be considered preferentially for gravitational field modeling.
Chronic diseases and non-melanoma skin cancer: is there an association?

Non-melanoma skin cancer (NMSC) has been associated with several other conditions, including melanoma and non-Hodgkin's lymphoma (Hjalgri et al., 2000; Hu et al., 2005). In addition, the risk of NMSC has been found to be greater in various chronic disease groups (Frisch and Melbye, 1995; Frisch et al., 1996). It is uncertain whether this association is related to the treatments for those chronic diseases (such as radiation therapy or immunosuppressant therapy) rather than the disease itself (Karagas et al., 2001; Saladi and Persaud, 2005). Moreover, using a Danish nationwide cohort of patients with NMSC, Jensen et al. (2006) found a lower mortality in basal cell carcinoma (BCC) patients compared with the general population, reflecting what the authors suggested to be a selection bias to that data set.
Reflections on Scholarship Reconsidered

Ernest Boyer's Scholarship Reconsidered recognizes and redefines three forms of scholarship (discovery, integration, and application) and acknowledges that the scholarship of discovery has maintained a central place in major research universities. Boyer's fourth form of scholarship, teaching, and its role in the modem university are challenges that the field of physical education must accept. It is incumbent on physical education professionals to reconsider the value we place on teaching and the manner in which institutional values, expectations, and practices impact the retention and promotion of faculty.
Relationship among adolescent reports of social anxiety, anxiety, and depressive symptoms

Abstract The present study examines the relationship among self-reported symptoms of social anxiety, anxiety, and depression in the context of Clark and Watson's tripartite theory of anxiety and depression for a sample of adolescents. Four hundred and twentyeight 10th-grade students completed three measures: the Social Anxiety Scale for Children-Revised, the Revised Children's Manifest Anxiety Scale, and the Children's Depression Inventory. Results suggest that symptoms of social anxiety are distinct from symptoms of depression and unspecified anxiety. In addition, results indicate that in comparison to males, adolescent females report higher levels of social anxiety, anxiety, and depressive symptoms. Conceptual and methodological implications are discussed.
An Illumination of the Roles of Hands‐On Activities, Discussion, Text Reading, and Writing in Constructing Biology Knowledge in Seventh Grade

A previous study (Wallace, Yang, Hand, & Hohenshell, 2001) indicated that seventh-grade life science students using a learning tool known as the Science Writing Heuristic (SWH) performed significantly better on conceptual test questions than did a control group. In the present study, the researcher studied more deeply how students utilized a variety of knowledge sources while engaged in the SWH, including textbook, teacher-led discussions, laboratory activities, peer group discussion, and writing (including their cognitive mechanisms and the nature of their written explanations). Six case students were selected based on a range of high to low achievement according to grades. An interpretive analysis of interview and document data was conducted. Of the 6 students, 3 relied on firsthand observations from laboratory activities as their major source of understanding; these students used listening, explaining, and writing most frequently. One student relied solely on textbook and teacher statements and actively rejected laboratory observations, relying primarily on reading and synthesis. Two students integrated laboratory observations with canonical information found in the textbook and other reading sources. They were able to bridge between the different epistemological bases for firsthand observations and authoritative text and blended these into rich and detailed explanations for biology concepts.
Distal realignment for recurrent patellar instability

Abstract There are multiple approaches to treating the patient presenting with recurrent patellar instability. Current thought emphasizes identifying the specific pathology allowing the instability, and then seeking to address that specific problem. Patients who show lateral positioning of the tibial tubercle as their isolated source of pathology may have improved outcomes if that particular problem is corrected through distal tibial tubercle medialization realignment. If these patients have patellar chondrosis, in addition to medialization, anteriorization is added in the manner of anteromedialization.
Philosophical problems, cluster concepts, and the many lives of Molyneux’s question

Molyneux’s question, whether the newly sighted might immediately recognize tactilely familiar shapes by sight alone, has produced an array of answers over three centuries of debate and discussion. I propose the first pluralist response: many different answers, both yes and no, are individually sufficient as an answer to the question as a whole. I argue that this is possible if we take the question to be cluster concept of sub-problems. This response opposes traditional answers that isolate specific perceptual features as uniquely applicable to Molyneux’s question and grant viability to only one reply. Answering Molyneux’s question as a cluster concept may also serve as a methodology for resolving other philosophical problems.
Mutations of endo-beta-N-acetylglucosaminidase H active site residues Asp130 and Glu132: activities and conformations.

Endo-beta-N-acetylglucosaminidase H hydrolyzes the beta-(1-4)-glycosidic link of the N,N'-diacetylchitobiose core of high-mannose and hybrid asparagine-linked oligosaccharides. Seven mutants of the active site residues, Asp130 and Glu132, have been prepared, assayed, and crystallized. They include single site mutants of each residue to the corresponding amide, to Ala and to the alternate acidic residue, and to the double amide mutant. The mutants of Asp130 are more active than the corresponding Glu132 mutants, consistent with the assignment of the latter residue as the primary catalytic residue. The amide mutants are more active than the alternate acidic residue mutants, which in turn are more active than the Ala mutants. The structures of the Asn mutant of Asp130 and the double mutant are very similar to that of the wild-type enzyme. Several residues surrounding the mutated residues, including some that form part of the core of the beta-barrel and especially Tyr168 and Tyr244, adopt a very different conformation in the structures of the other two mutants of Asp130 and in the Asp mutant of Glu132. The results show that the residues in the upper layers of the beta-barrel can organize into two very distinct packing arrangements that depend on subtle electrostatic and steric differences and that greatly affect the geometry of the substrate-binding cleft. Consequently, the relative activities of several of the mutants are defined by structural changes, leading to impaired substrate binding, in addition to changes in functionality.
A high-silica zeolite with a 14-tetrahedral-atom pore opening

Zeolites (microporous aluminosilicates) and related molecular sieves have found wide application as catalysts, sorbents and ion-exchange materials. New zeolites with large pores are much in demand, and have been sought for several decades. All known zeolites, both natural and synthetic, contain pores comprised of 12 or fewer tetrahedrally coordinated silicon or aluminium atoms (T-atoms), but several microporous aluminophosphates with wider pores are now known. The practical value of these large-pore phosphate-based materials is limited, however, by their poor thermal and hydrothermal stability. Here we report the synthesis of a high-silica zeolite with pores comprised of 14 T-atoms. Preliminary data indicate that this thermally stable large-pore material exhibits the kind of strong acidity that makes other zeolites useful catalysts.
Production of Hexagenia limbata nymphs in contaminated sediments in the Upper Great Lakes Connecting Channels

In April through October 1986, we sampled sediments and populations of nymphs of the burrowing mayfly, Hexagenia limbata (Serville), at 11 locations throughout the connecting channels of the upper Great Lakes, to determine if sediment contaminants adversely affected nymph production. Production over this period was high (980 to 9231 mg dry wt m-2) at the five locations where measured sediment levels of oil, cyanide, and six metals were below the threshold criteria of the U.S. Environmental Protection Agency and the Ontario Ministry of Environment for contaminated or polluted sediments, and also where the criterion for visible oil given in the Water Quality Agreement between the U.S.A. and Canada for connecting waters of the Great Lakes was not exceeded. At the other six locations where sediments were polluted, production was markedly lower (359 to 872 mg dry wt m-2). This finding is significant because it indicates that existing sediment quality criteria can be applied to protect H. limbata from oil, cyanide, and metals in the Great Lakes and connecting channels where the species fulfills a major role in secondary production and trophic transfer of energy.
Effects of IUU fishing and stock enhancement on and restoration strategies for the stellate sturgeon fishery in the Caspian Sea

Abstract Sturgeon is the most valuable fish species because of the high demand for their roe. The sturgeon fishery was historically the most important fishery in the Caspian Sea, but the major sturgeon species have now been classified as “critically endangered” by the International Union for Conservation of Nature. Considering commercial importance and data availability, we focus this study on stellate sturgeon. By applying a Depletion-Based Stock Reduction Analysis to model the population dynamics of the stellate sturgeon in the Caspian Sea, we estimate that the current stock is only 16% of the biomass (BMSY) that can produce the maximum sustainable yield (MSY). If all fish removals are stopped and no more stock enhancement takes place in the future, the stock would recover to BMSY by 2035 on average, with a 50% probability of it occurring between 2029 and 2058. If stock enhancement continues at the 2010 level, the rebuilding process will be 5 years faster, reaching BMSY by 2030. In contrast, if IUU fishing continues at the current level and only legal fishing is stopped, the stellate sturgeon will fail to recover and become extinct by 2042 without stock enhancement. Therefore, the priority of conserving the stellate sturgeon stock in the Caspian Sea is to eliminate IUU fishing. Practical rebuilding plans need also to include a combination of reducing fishing removals and restoring the spawning potential of the stock that has been lost by human interruptions in the ecosystem such as destruction of spawning grounds and overfishing.
Mapping information delivery networks: the objectives, the methods, the benefits, and the model

In response to the need to summarize the use of information/telecommunications technologies, to understand these technologies, and to comprehend the extent of public information delivery systems in use or in place in a region of the Pacific Northwest, the authors have designed a compact atlas. This atlas combines data and information blocks with information technology graphics blocks and maps showing the actual locations of information delivery systems. The atlas, entitled “Information Highways: Mapping Information Delivery Networks in the Pacific North west,” provides a model for assimilating large volumes of information dealing with generic topics. This model utilizes maps of text and graphics to create a pictorial context for conceptualizing what exists and what might exist.
Physical therapy versus heparin for prevention of deep venous thrombosis.

Agarwal and Mathur1 have shown that administration of heparin fails to improve on the low incidence of clinically detectable deep venous thrombosis (DVT) in their acute spinal cord injury (SCI) cohort. They suggest that physical therapy, genetics or life style may have preempted the need for heparin. I write to suggest that physical therapy in the form of range of motion (ROM) to the paralyzed extremities is the explanation. In the cited Todd study,2 in which the prevalence of DVT was 100%, the frequency of ROM was nil to no more than once a day. This is in contrast to the 6% prevalence of DVT in the subsequent Frisbie3 study—at the same institution and using the same sensitive radioiodinated fibrinogen leg scanning technique—in which ROM was given 2–3 times a day and the addition of heparin in a randomized group failed to further reduce the prevalence of DVT.2
A preliminary investigation of powered prostheses for improved walking biomechanics in bilateral transfemoral amputees

The authors conducted a preliminary investigation of the extent to which a pair of powered prostheses can provide improved gait biomechanics in bilateral transfemoral amputee walking. Specifically, a finite state-based impedance controller for level ground walking was implemented in a pair of powered knee and ankle prostheses. The efficacy of the powered prostheses and impedance-based controllers was tested on a healthy subject using able-body adapters. Motion capture data was collected while the subject performed treadmill walking with the powered prostheses. This kinematic data is compared to that of healthy subjects, and also to previously published data for bilateral transfemoral amputee gait with passive prostheses. The comparison indicates that the powered prostheses are able to provide a walking gait that is considerably more representative of healthy biomechanical gait relative to passive prostheses.
Sex differences in biochemical manifestations of selenium deficiency in rat liver with special reference to heme metabolism

Abstract In addition to its well-known effect on glutathione peroxidase, selenium deficiency causes: (1) a defect in hepatic heme metabolism characterized by a phenobarbital-mediated increase in microsomal heme oxygenase activity, and (2) an increase in hepatic glutathione S -transferase activity. Since these effects were reported in selenium-deficient male rats, and since female rats have a lower selenium requirement than males, we examined whether these effects were sex-dependent. Weanling male rats, female rats, castrated male rats, and testosterone-treated female rats were fed either a selenium-deficient or a control diet. After 8 weeks, selenium-dependent hepatic glutathione peroxidase activity was 1 per cent of respective control values in each of the selenium-deficient groups. Hepatic glutathione, S -transferase activity was doubled by selenium deficiency in normal, unoperated males but was unaffected in the other groups. In control diet fed rats phenobarbital given as a single injection caused either no significant change or a decrease in the activity of hepatic microsomal heme oxygenase, the rate-limiting enzyme in heme degradation. In contrast, microsomal heme oxygenase activity was stimulated by phenobarbital in all selenium-deficient rats. The stimulation was greatest in males and least in females with intermediate values in castrated males and testosterone-treated females. These results demonstrate a marked effect of sex, castration of males, and testosterone treatment of females on the response of hepatic heme metabolism to phenobarbital and on glutathione S -transferase activity in selenium deficiency even though glutathione peroxidase was reduced to the same extent by selenium deficiency in all groups.
Transport of Carbon and Nitrogen Between Litter and Soil Organic Matter in a Northern Hardwood Forest

We used sugar maple litter double-labeled with 13C and 15N to quantify fluxes of carbon (C) and nitrogen (N) between litter and soil in a northern hardwood forest and the retention of litter C and N in soil. Two cohorts of litter were compared, one in which the label was preferentially incorporated into non-structural tissue and the other structural tissue. Loss of 13C from this litter generally followed dry mass and total C loss whereas loss of 15N (20–30% in 1 year) was accompanied by large increases of total N content of this decaying litter (26–32%). Enrichment of 13C and 15N was detected in soil down to 10–15 cm depth. After 6 months of decay (November–May) 36–43% of the 13C released from the litter was recovered in the soil, with no differences between the structural and non-structural labeled litter. By October the percentage recovery of litter 13C in soil was much lower (16%). The C released from litter and remaining in soil organic matter (SOM) after 1 year represented over 30 g C m−2 y−1 of SOM accumulation. Recovery of litter 15N in soil was much higher than for C (over 90%) and in May 15N was mostly in organic horizons whereas by October it was mostly in 0–10 cm mineral soil. A small proportion of this N was recovered as inorganic N (2–6%). Recovery of 15N in microbial biomass was higher in May (13–15%) than in October (about 5%). The C:N ratio of the SOM and microbial biomass derived from the labeled litter was much higher for the structural than the non-structural litter and for the forest floor than mineral SOM, illustrating the interactive role of substrates and microbial activity in regulating the C:N stoichiometry of forest SOM formation. These results for a forest ecosystem long exposed to chronically high atmospheric N deposition (ca. 10 kg N ha−1 y−1) suggest possible mechanisms of N retention in soil: increased organic N leaching from fresh litter and reduced fungal transport of N from soil to decaying litter may promote N stabilization in mineral SOM even at a relatively low C:N ratio.
Primary aberrations of Fresnel lenses

Mathematical expressions derived for the primary aberrations of a thin, flat Fresnel lens (grooved on both surfaces, in general) as functions of the constructional parameters are convenient for the analytic design of optical systems containing one or more Fresnel lenses. In general. such systems have five primary monochromatic aberrations of the Seidel type plus a sixth that is identically zero for ordinary lenses. The new aberration (called line coma to distinguish it from ordinary circular coma) bears the same relation to sagittal and tangential coma that Petzval curvature bears to sagittal and tangential astigmatism. Moreover line coma is independent of stop position, whereas Petzval curvature varies with stop position unless the line coma is corrected. The primary chromatic aberrations and the aberration contributions of Fresnel aspherics are the same as for ordinary lenses. Specific applications of the theory are discussed.
Autoradiographic localization of calcium in the mucosal cells of the avian oviduct.

The cellular location of calcium in the mucosa of the avian oviduct has been studied by45Ca autoradiography in tissue prepared either by incubation with45Ca or by intravenous injection of45Ca. Freeze-substitution was used to retain easily diffusible calcium in the tissue.In vitro, columnar epithelium of the shell gland acquired significantly more45Ca as the length of incubation time was increased from one to ten minutes and/or when the temperature was raised from 0° to 42°. These effects were diminished by the addition of dinitrophenol to the incubation medium. The tubular glands of this tissue responded minimally. Genrally, after intravenous injection of45Ca, the shell gland sequestered, more radionuclide than the other regions of the oviduct. When an egg shell was being calcified, the columnar epithelium of the shell gland revealed a higher grain count than the tubular glands, but when a shell was not forming, grain counts were similar over the two types of cells.
Glassy Carbon low-temperature thermodynamic properties

The heat capacity of Glassy Carbon was measured by adiabatic calorimetry from 5 to 350 K and has no transitions or thermal anomalies. It parallels that of pyrolytic graphite annealed at 2600 °C in showing an approximate T2 dependence up to 30 K suggesting that the structure of this material may involve microdomains of lamellar graphite. At 298.15 K, the measured heat capacity at constant pressure (Cp), the entropy (So − S0o), and the enthalpy function }(Ho − H0o)T{ are 2.055, 1.406, and 0.857 cal K−1 mol−1.
Pump-probe optical coherence microscopy

High-resolution optical molecular imaging has become a vital tool for understanding and measuring physiologically important biometrics on the cellular and subcellular level. In spite of significant recent advances in microscopy, molecular imaging of most endogenous biomolecular species remains elusive. Directly imaging endogenous biomolecules without the aid of exogenous tags is highly desirable. We developed pump-probe optical coherence microscopy (PPOCM) based on our previous success in integrating pump-probe absorption spectroscopy with optical coherence tomography. A fixed human skin tissue with melanoma was imaged by the PPOCM system. The preliminary results show that PPOCM can provide better can clear contrast between normal tissue and melanoma than OCM. This system also can be used to image other chromophores.
145 CHARACTERIZATION OF THE PROTEIN ARGININE METHYLTRANSFERASE-DIMETHYLARGININE DIMETHYLAMINOHYDROLASE-NITRIC OXIDE AXIS DURING PORCINE EMBRYO DEVELOPMENT

Transcriptional deep sequencing analysis by Bauer et al. (2010) revealed a significant increase in expression of the arginine transporter SLC7A1 in in vitro–cultured porcine blastocysts compared with those cultured in vivo and this was corrected through supplemental arginine. This indicates an important role for arginine during porcine embryo development. Arginine is the precursor for nitric oxide (NO) production and previous work in mice and cattle has shown decreased development when embryos were cultured with a nitric oxide synthase (NOS) inhibitor. The NOS activity is inhibited by monomethylarginine (MMA) and asymmetric dimethylarginine (ADMA) that are released during degradation of proteins methylated by protein arginine methyltransferases (PRMT). The enzyme dimethylarginine dimethylaminohydrolase (DDAH) is responsible for degrading MMA and ADMA in the cell. Therefore, the goal of this study was to investigate whether this PRMT-DDAH-NO axis exists in pre-implantation porcine embryos. To this end, expression of PRMT1, PRMT3, PRMT5, DDAH1 and endothelial NOS (NOS3) was analysed at different stages of embryonic development using real-time quantitative RT-PCR. In addition, the effect of supplemental arginine (1.69 mM) on the expression of the aforementioned genes was investigated. Production of NO in porcine embryos was also visualised using 4-amino-5-methylamino-2,7-difluorofluorescein diacetate (DAF-FM-DA). In vitro–fertilized porcine embryos were collected at the 4-cell and blastocyst stages. The RNA was isolated from pools of 18 to 20 embryos and cDNA, was synthesised using Superscript III (Invitrogen, Carlsbad, CA, USA). Real-time PCR analysis was performed and the mean fold change in gene expression from the reference gene YWHAG was analysed by t-test after a log transformation. Expression of PRMT3 and PRMT5 was significantly higher (P < 0.05) in blastocysts versus 4-cell embryos. Expression of PRMT1, however, was higher in 4-cell embryos (P < 0.05). The expression of DDAH1 was detected in 4-cell embryos, but DDAH1 became undetectable by the blastocyst stage. Previous microarray analysis in our laboratory by Whitworth et al. (2005 Biol. Reprod. 72(6), 1437–1451) also revealed a significant up-regulation of DDAH2 expression at the 4-cell stage versus blastocysts. Expression of NOS3 was undetectable in the 4-cell and blastocyst; however, NO was detected in 4-cell and blastocyst stage embryos by using DAF-FM-DA. This suggests that a different NOS may be acting in the porcine embryo. Addition of arginine did not have a significant effect on expression of the analysed genes. These results suggest that PRMT-DDAH regulated NO production may play a role during porcine embryo development. Understanding the PRMT-DDAH-NO axis and its regulation during embryonic development will further our ability to tailor in vitro culture so that it more appropriately mimics that of an in vivo environment. Funding was provided by NIH U42 RR18877.
A Stages of Change Approach to Understanding College Students' Physical Activity

This study examined self-reports of physical activity behavior among college students from a stages of change perspective. A questionnaire on health needs was administered to a random sample of 800 students at a private university; 217 completed questionnaires were analyzed, using chi-square statistics. In addition to examining activity behavior from a stages of change approach, the authors explored the relationship of demographic variables to activity behavior. Forty-six percent of the students were inactive or were exercising irregularly. Gender and year in school were unrelated to stage of exercise adoption. Results from this pilot study indicate the need for stage-matched interventions to increase activity levels in young adults.
Understanding the surface orientation of liquids

Abstract Numerous studies have found that approximately 40% of the adult population behave as if they do not know that water remains horizontal, regardless of the orientation of its container. In the present set of experiments, it was shown that subjects who perform inaccurately do so because they have misrepresented the problem. These individuals are not answering the environment-relative question, “What should the water's surface orientation be relative to the environment?” Instead, they attempt to solve an object-relative problem, “How should water incline relative to its tilted container?” It was shown that subjects' problem representations can be influenced by manipulating the manner in which the problem is presented, and that performance is affected accordingly. Experiment 1 was a pretest, designed primarily to identify individuals who perform correctly or incorrectly on the traditional paper-and-pencil task. Experiment 1 also demonstrated that by promoting an object-relative perspective, a majority of subjects can be induced into performing incorrectly on the water level problem. Experiment 2 found that when individuals were led to evaluate the problem from an environment-relative perspective, they performed accurately, regardless of their performance in Experiment 1. Experiment 3 found that subjects who performed incorrectly on the paper-and-pencil problem are not simply more variable than those who are accurate, but rather that the object-relative perspective creates a bias toward drawing liquid surface orientations that incline in the same direction as the tilt of the container. Experiment 4 found that the response bias observed in Experiment 3 is the result of a frame of reference perceptual influence. The orientation of the surrounding container affects the apparent tilt of the liquid surface. In summary, it was shown that people fail on the water level problem, not because they are lacking the relevant knowledge, but rather because they are attempting to solve a different problem—a problem represented in an objectrelative, as opposed to an environment-relative coordinate system. Moreover, object-relative solutions manifest a perceptual bias that is inherent in all people.
Clinical trials: to terminate or not to terminate.

Excerpt To the Editors:Laupacis and colleagues (1) are to be commended on their excellent analysis of the influence of completed studies on ongoing clinical trials. Their decision to stop the trial...
Application of modulation spectrum for iEEG seizure analysis

Millions of people worldwide suffer with recurrent epileptic seizures that often require hospitalized intracranial electroencephalography (iEEG) for diagnosing their seizure onset zone (SOZ) for surgical therapy. The standard diagnostic procedures for the brain signals rely on time-consuming human review of data via visual analysis. This study investigates whether modulation spectrum measures, with further study, could provide a quantitative algorithmic approach to reliably identify the SOZ for a patient and reduce or eliminate the burden of manual iEEG review. In a pilot dataset of four patients (one seizure per person), we analyzed human iEEG before, during, and after their seizure from signals inside and outside their clinically annotated SOZ to observe changes in 49 modulation spectrum measures. Regarding electrode location effects (i.e., inside vs. outside SOZ), we observed statistically significant differences (p <; 0.001) in modulation measures at certain cross-frequency bins (e.g., δ:γ bandwidths) with high effect size (g ≥ 0.80) for some patients. For seizure state effects, we observed significant differences with high effect size in many measures across almost all cross-frequency bins between various pairings of seizure states (e.g., during vs. before) for all patients. We concluded that the modulation spectrum had potential in quantifying SOZ and seizure states for diagnostic purposes and in understanding the effect of seizures on brain networks.
Exchange rate volatility and demand for money in Iran

In 1963, Nobel Laureate, Robert Mundell (1963) argued that the demand for money could depend on the exchange rate, in addition to income and interest rate. In this paper, we argue that, in addition to the exchange rate itself, its volatility could also serve as another determinant of the demand for money. We demonstrate our conjecture by using data from post–revolutionary Iran and the bounds testing approach. Our results reveal that indeed, exchange rate volatility has short–run as well as long–run effects on the demand for real M2 monetary aggregate in Iran.
Studies on the Limulus coagulation system: inhibition of activation of the proclotting enzyme, by dimethyl sulfoxide.

Abstract Dimethyl sulfoxide inhibits the endotoxin-induced clotting activity of Limulus amoebocyte lysate. The inhibition is dependent upon the concentration of dimethyl sulfoxide and is competitive with endotoxin. Further studies showed that dimethyl sulfoxide inhibited the clot formation by reversibly inhibiting the activation of the proclotting enzyme to the clotting enzyme. Dimethyl sulfoxide had no effect on the active form of the clotting enzyme. Based on these findings, a procedure has been developed for the isolation of the proclotting enzyme from Limulus amoebocyte in the presence of dimethyl sulfoxide.
Acute Effects of Nalmefene on LH, Prolactin, and Testosterone in Male Rhesus Monkeys

Abstract The effects of the long-acting opioid antagonist, nalmefene [17-N-cyclopropylmethyl-3,14-β-dihydroxy-4,5-α-epoxy-6-methylene morphinan hydrochloride] on LH, T, and prolactin release in rhesus monkeys are unknown. The acute effects of nalmefene (0.01 and 0.10 mg/kg, IV) or placebo on LH, PRL, and T were studied, and samples were collected at 10-min intervals for 360 min to permit cluster analysis of pulsatile release patterns. LH increased significantly within 30 min after nalmefene, and remained significantly above baseline levels for 50 to 60 min ( p p
Divalent cations and cytochalasin B-sensitive processes in activation, synthesis, and release of mixed leukocyte reaction suppressor factor

Abstract We have examined the possible rotes of divalent cations and of cytochalasin B-sensitive processes in the production of mixed leukocyte reaction suppressor factor (MLR-TsF). Ca but not Mg was strictly required for MLR-TsF production. A requirement for Mg could be demonstrated only under conditions of Ca depletion, suggesting an intimate linkage in divalent cation requirements. Ca was required for synthesis as well as release of the suppressor factor. Cytochalasin B inhibited MLR-TsF production only when present during the first 4 hr of culture; such inhibition was reversible with incubations of up to 16 hr. This indicated that cytochalasin B inhibited early events of activation, rather than synthesis or release of MLR-TsF. It was found that both Ca and Mg were required either before or during the cytochalasin-sensitive steps in the activation sequence. The relationship of cytochalasin B-sensitive events in early activation to the antigenic stimulus per se was established by limited exposure of suppressor cells to allogeneic stimulators fixed to poly- l -lysine (PLL)-coated plates. Maximal stimulation was observed with a 4-hr exposure, and this antigen-dependent commitment was cytochalasin B sensitive.
Semiclassical fifth virial coefficients for improved ab initio helium-4 standards

For helium-4, we present ab initio, semiclassical calculations of virial coefficients Bn for n = 2, 3, 4, and 5 from 50 to 1000 K. Using our values of B4 and B5 and the more accurate literature values of B2 and B3, we argue that the ab initio virial equation of state is more accurate than recent, high-quality, densimeter measurements spanning the range {223 K < T < 500 K, p < 38 MPa}. Thus, the present values of B4 and B5 extend the useful temperature and density range of ab initio helium standards.
HORMONAL CONTROL OF CHLORIDE SECRETION BY CANINE TRACHEAL EPITHELIUM: AN ELECTROPHYSIOLOGIC ANALYSIS*

A principal event in the stimulation of cyclic AMP-induced active C1 secretion across canine tracheal epithelium is an increase in the C1 permeability of the apical cell membrane. This permits C1 to leave the cell down its electrochemical potential difference across this barrier. C1 transport across the basolateral membrane appears to be nonconductive and may be mediated by NaC1 cotransport. Increased C1 entry across the basolateral membrane would enhance Na entry into the cell and secondarily stimulate Na extrusion from cell to submucosal solution. Increased Na-K-pump activity or an increase in the K permeability of the basolateral membrane may be responsible for the (Formula in text) reduction in basolateral membrane resistance that accompanies stimulation of C1 secretion. Analysis of the electromotive force across the apical cell membrane under conditions where C1 secretion is inhibited or stimulated provides reasonable estimates of intracellular Na and C1 activities for these conditions.
THE BIOLOGICAL DECOMPOSITION OF PLANT NATERIALS: PART IX. THE AEROBIC DECOMPOSITION OF HEMICELLULOSES

SUMMARY. 1. The decomposition of the hemicelluloses of plant materials occurs rapidly under normal aerobic conditions. Since a number of fungi have been shown by analyses of pure culture rots to be active in fermenting this group, as well as cellulose, some seventy common fungi, mostly Aspergilli and Penicillia, were tested as to their ability to utilise on agar plates the crude hemicellulose from oat straw. 2. All of the fungi tested grew reasonably well on the hemicellulose medium, the majority at least as well as on glucose, and a number better than on that sugar. In some cases there was production of a cleared zone round the colony due to an exo-enzyme. It is likely that ability to ferment hemicelluloses will be found to be a general property of common fungi. 3. From soil, manure, and straw, twenty aerobic bacteria were isolated capable of utilising hemicelluloses. Three of these were thermophilic forms. Their morphological characters and biochemical reactions were determined. 4. All the organisms utilised a very wide range of sugars and poly-saccharides; one group produced some acid and gas, the remainder little. Differentiation was obtained on saccharic acid and certain disaccharide acids. 5. Five of the mesophilic organisms agreed closely with the description of Achromobacter ubiquitum (Jordan). The remainder were aerobic spore-formers, though not all Gram-positive. The negative forms may represent new species. 6. None of the organisms in pure culture could validly be described as active in decomposing the isolated hemicellulose, or that in situ in straw. 7. Fungi seem to be more active and important in the natural decomposition of hemicelluloses than bacteria, unless when working in association the rather restricted individual fermentative powers of the latter are considerably enhanced.
Hydroxyl radicals in indoor environments

Abstract Indoor hydroxyl radical concentrations were estimated using a new indoor air quality model which employs the SAPRC-99 atmospheric chemistry model to simulate indoor homogenous reactions. Model results indicate that typical indoor hydroxyl radical concentrations are lower than typical outdoor summertime urban hydroxyl radical levels of 5–10×106 molecules cm−3; however, indoor levels can be similar to or greater than typical nighttime outdoor hydroxyl radical levels of approximately 5×104 molecules cm−3. Effects of selected parameters on indoor hydroxyl radical concentrations are presented herein. Indoor hydroxyl radical concentrations are predicted to increase non-linearly with increasing outdoor ozone concentrations, indoor alkene emission rates, and air exchange rates. Indoor hydroxyl radical concentrations decrease with increasing outdoor nitric oxide concentrations. Indoor temperature and indoor light intensity have moderate impacts on indoor hydroxyl radical concentrations. Outdoor hydroxyl radical concentrations, outdoor nitrate (NO3 ) radical concentrations, outdoor hydroperoxy radical concentrations, and hydroxyl radical removal by indoor surfaces are predicted to have no appreciable impact on indoor hydroxyl radical concentrations. Production of hydroxyl radicals in indoor environments appears to be controlled primarily by reactions of alkenes with ozone, and nitric oxide with hydroperoxy radical. Estimated indoor hydroxyl radical levels may potentially affect indoor air quality. Two examples are presented in which reactions of d-limonene and α-pinene with indoor hydroxyl radicals produce aldehydes, which may be of greater concern than the original compounds.
SU-E-QI-04: Curve Fitting of Time-Density Data From CT Circulation Timing Scans for Estimation of Cardiac Output

Purpose: To develop a robust algorithm for fitting gamma variate functions to time-density data acquired during a circulation time scan in preparation for a CT pulmonary angiogram (CTPA). Methods: Timedensity information in the main pulmonary artery (MPA), ascending aorta (AA), and descending aorta (DA) was retrospectively collected for 10 patients undergoing CTPA. Measurements prior to the arrival of contrast were used to estimate the baseline (blood) density value. The estimated contrast arrival delay time was varied over a range of values and the maximum correlation coefficient was used to estimate the delay time. In a second approach, an additional step was performed by shifting the data in time relative to the best-fit gamma variate and calculating a mean-squared difference (MSD). The minimum MSD was used to find a new estimate of the delay time, after which a new gamma variate fit was performed. This process was iterated five times. The final gamma variate fit was used to estimate the cardiac output (CO). Results: The mean CO for all patients and all vessels was 6.8 l/min for both methods. To compare the robustness of the two methods, coefficient of variation (CV) of CO for the three vessels was computed for each patient. For method 1, the average CV was 0.054, for method 2 it was 0.023. Using method 2, the CV decreased for all but one patient, for whom it increased from 0.01 to 0.02. On average the CV was reduced by 57% using method 2. Conclusion: Cardiac output may be estimated by using the time-dilution data collected during a circulation timing scan acquired at CTPA. Care must be taken in fitting a model to the data to ensure robust results. The method described has proven to reduce the variability in CO values estimated for different vessels in a single scan.