cssi/SciSciGPT-SciSciNet huggingface dataset:
BIOCHEMICAL ANALYSIS OF THE N-GLYCOSYLATION PATHWAY IN BACULOVIRUS-INFECTED LEPIDOPTERAN INSECT CELLS

Abstract The baculovirus—insect cell system is used routinely for foreign glycoprotein production, but the precise nature of the N-glycosylation pathway in this system remains unclear. Some studies indicate that these cells cannot process N-linked oligosaccharides to complex forms containing outer-chain galactose and sialic acid, while others indicate that they can. In this study, we used the major virion envelope glycoprotein of the baculovirus Autograpba californica multicapsid nuclear polyhedrosis virus (AcMNPV) to probe the N-glycosylation pathway in baculovirus-infected lepidopteran insect cells. The results showed that gp64 contained mannose, fucose, and probably N -acetylglucosamine, but no detectable galactose or sialic acid. These same results were observed with gp64 produced in any one of three different lepidopteran insect cell lines derived from Spodoptera frugiperda , Trichoplusia ni , or Estigmene acrea , whether it was produced at relatively earlier or later times after infection. These results indicated that the gp64 produced in AcMNPV-infected lepidopteran insect cells lacks complex N-linked oligosaccharides containing outer-chain galactose and sialic acid. By contrast, gp64 produced in mammalian cells contained both galaclose and sialic acid, and endoglycosidase digestions revealed that these sugars were constituents of N-linked, not O-linked, oligosaccharides. This showed that at least one N-linked side chain on gp64 has the potential to be processed to a complex form. Together, these results suggest either that AcMNPV-infected lepidopteran insect cells are unable to convert any of the N-linked side chains on gp64 to complex structures or that outer-chain galactose and sialic acid residues are added to gp64 and then removed by cellular or viral exoglycosidases.
Frequency shifts in the spectral distribution of the reflectivity from a resonant medium with spatially modulated density

We show that in reflection from a periodic density-modulated homogeneously broadened resonant medium, the maximum of the reflectivity spectral distribution can be substantially shifted from the resonant frequency. This shift takes opposite signs depending on whether the wavevector of the density distribution is smaller or larger than the Bragg condition value.
Clathrin-coated vesicles from human placenta contain GTP-binding proteins

Biochemical and morphological techniques were used to investigate the GTP-binding proteins of clathrin-coated vesicles. Binding of [3H]GTP to clathrin coats was demonstrated by electron microscopic autoradiography. Purified coated vesicles bound 5.2 pmol [35S]GTP gamma S/mg protein. Addition of GTP or GTP gamma S, but not ATP nor GMP, inhibited binding of [35S]GTP gamma S to intact coated vesicles and Triton X-100-extracted coats. A series of 23-24 kDa GTP-binding proteins with isoelectric points between pH 5-8 were detected in coated vesicles. We suggest that the low molecular weight ras-like GTP-binding protein(s) play a role in regulating vesicle-mediated protein transport or signal transduction within intracellular organelles.
Numeracy and the institution: mapping factors of cultural change

This paper outlines some of the factors that must be considered when attempting systemic institutional change in the educational setting. Understanding systemic change is critical to effective educational reform, promoting quantitative literacy, and successful curriculum development.
Efficient OFDM Denial in the Absence of Channel Information

Many modern communications systems use Orthogonal Frequency Division Modulation (OFDM). These systems need to synchronize the receiver and equalize the channel to achieve good performance. The algorithms used to perform timing synchronization and channel estimation/equalization typically are designed without considering whether an adversarial signal could disrupt these subsystems. In typical scenarios, a jammer would not have reliable (or any) knowledge of the channels filtering the target or jamming signals. Thus, in this paper, we consider attack strategies that do not require channel knowledge. We study the efficiency of several jamming strategies targeting each subsystem as measured by the peak and average signal-to-jamming ratio (SJR) required to achieve signal denial for each method and find that jamming the timing can be substantially more efficient than other jamming strategies. We also discuss modifications to the jamming strategies that might be necessary for real-world operation.
Shifts of bacteriochlorophyll and carotenoid absorption bands linked to cytochrome c-555 photooxidation in Chromatium.

Shifts in the absorption bands of bacteriochlorophyll and carotenoids in Chromatium vinosum chromatophores were measured after short actinic flashes, under various conditions. The amplitude of the bacteriochlorophyll band shift correlated well with the amount of cytochrome c-555 that was oxidized by P870+ after a flash. No bacteriochlorophyll band shift appeared to accompany the photooxidation of P870 itself, nor the oxidation of cytochrome c-552 by P870+. The carotenoid band shift also correlated with cytochrome c-555 photooxidation, although a comparatively small carotenoid shift did occur at high redox potentials that permitted only P870 oxidation. The results explain earlier observations on infrared absorbance changes that had suggested the existence of two different photochemical systems in Chromatium. A single photochemical system accounts for all of the absorbance changes. Previous work has shown that the photooxidations of P870 and cytochrome c-555 cause similar changes in the electrical charge on the chromatophore membrane. The specific association of the band shifts with cytochrome c-555 photooxidation therefore argues against interpretations of the band shifts based on a light-induced membrane potential.
Jam Processing Effect on Phenolics and Antioxidant Capacity in Anthocyanin-rich Fruits: Cherry, Plum, and Raspberry

ABSTRACT: Four cultivars of sour cherries (Balaton, Karneol, Kroeker and Northstar), 2 cultivars of plums (BY 8158.50 and Methley), and 1 red raspberry cv. Prelude were analyzed for total phenolics, antioxidant capacity, and total anthocyanins before and after jam production to evaluate their changes after thermal processing. Fruits had total phenolics ranging from 245.7 to 398.5 mg gallic acid equivalent (GAE)/100 g. Antioxidant capacity of fruits ranged from 354.8 to 692.3 mg/100 g, expressed as vitamin C equivalent antioxidant capacity (VCEAC). Total anthocyanins of fruits ranged from 30.9 to 67.1 mg cyanidin 3-glucoside equivalent (CGE)/100 g. In 100 g of jam, total phenolics varied from 132.9 to 218.9 mg GAE, while antioxidant capacity ranged from 205.6 to 373.5 mg/100 g VCEAC. Jams had total anthocyanins of 5.4 to 30.4 mg CGE/100 g. On the basis of fresh fruit (100 g), the processing and heating during jam making generally decreased the contents of total phenolics, VCEAC, and total anthocyanins. Major losses occurred in anthocyanin content where overall retention varied from 89% to 21%. HPLC analysis of individual anthocyanins from cherry cv. Balaton to its jam showed that processing caused 90% decrease in anthocyanins. The results indicated that more than 73% total phenolics and more than 65% antioxidant capacity were retained after processing fruits into jams. Optimization of food processing would help to conserve the bioactive phenolic compounds in fruits.
Processing open and closed class-headed nonwords: Left hemisphere support for separate vocabularies ☆

Evidence from studies of sentence production and comprehension points to a distinction between the open and closed class vocabularies. Data from the neurologically impaired suggest the left hemisphere selectively supports this distinction. This study further examines the vocabulary distinction by presenting to the different visual hemifields nonwords embedded with open or closed class portions, and asking normal subjects to make lexical decisions. Results indicate the vocabulary distinction is evident with RVF, but not LVF, presentations. This is discussed in terms of the use to which open and closed class words are put in sentence processing and also bears on the issue of the distinct cognitive styles associated with the different cerebral hemispheres.
Effects of time-varying haze production on Titan's geometric albedo

Abstract Two versions of the Toon et al. (1992, Icarus 95, 24-53) Titan haze model were used to simulate the observed blue and yellow geometric albedo variations using a time-dependent haze production. Steady-state calculations were used to suggest that the range of production rate changes necessary to explain the observations was a factor of between 2 and 4. However, the blue and yellow geometric albedo variations were about 10 times smaller than the observations, when computed with a time-varying production rate with this same range. Long haze residence times were the cause of this decreased response. This result was insensitive to the details of the functional representation of the production. In addition to the amplitude of the geometric albedo, we found that the phase between albedo response and the production forcing is a critical discriminate when comparing model results to the observations. Long haze time scales also produced a phase delay in the albedo response to seasonal solar forcing which can agree with the observations (Sromovsky et al. 1981, Nature 292, 698-702). Unfortunately, the size of the phase delay was dependent on model parameters. We found that raising the level of rainout well into the stratosphere (90 km) decreased the residence time of the haze and allowed us to fit the magnitude of the albedo variation. However, the resulting phase delay (-60°) was not in agreement with observations (+90°) and such a high altitude for rainout is probably un-physical. Our results suggest that a time-varying mass production cannot explain Titan's geometric albedo variations.
Formation of New Intermetallic Phases in Binary Eutectic Systems by Drastic Undercooling of the Melt

IT has earlier been reported1–3 from our Laboratory that some eutectic binary alloys solidify in an amorphous condition on rapid cooling from the liquid state. The present communication deals with new crystalline phases obtained by subjecting liquid alloys of eutectic systems to severe undercooling during solidification.
Optimal cooling system design for multi-cavity injection molding

Abstract The objective of this paper is to present a methodology for optimal design of cooling systems for multi-cavity injection mold tooling. After the part layout and the injection mold are designed, the methodology optimizes cooling system layout in terms of cooling channel size, locations, and coolant flow rate. The mold cooling design is modeled as a non-linear constrained optimization problem. The objective function for the constrained optimization problem is stated as minimization of both a function related to part average temperature and temperature gradients throughout all the cavities. The constrained optimal design problem is solved using Powell's conjugate direction with the penalty function method. The objective function is evaluated using finite element analysis solving the transient heat conduction problem. A matrix-free Jacobi conjugate gradient algorithm of Galerkin finite element method is utilized to simulate transient heat conduction.
On stability independent of delay for linear systems

A new criterion for asymptotic stability of solutions of certain linear differential-difference equations (independent of the delay duration) is given in terms of solutions of a complex Lyapunov matrix equation.
Gold sorption onto pyrite and goethite: A radiotracer study

The sorption of gold onto pyrite and goethite in deionized water and seawater containing 510 pg L−1 Au has been determined using radiotracer techniques. Most of the gold is removed from solution in the first two days. Gold colloids, present in solution along with dissolved gold [predominantly Au(OH)H2O0], are rapidly removed upon addition of the substrates. The removal of gold colloids is due either to direct uptake of the Au colloids or to dissolution and subsequent adsorption. Dissolution of gold colloids is to be expected if equilibrium is maintained between colloids and aqueous gold species. Pyrite is a much more efficient scavenger of gold than is goethite. The surface-normalized partition coefficients, Ksd's, for pyrite range from 2.9–5.6 · 102 [Lm−2] in deionized water to 0.7–1.1 · 102 [Lm−2] in seawater. The Ksd for goethite in deionized water is 5.1–0.53 [L m−2]; its Ksd in seawater is >3.7 · 10−2 [L m−2], but probably lower than in deionized water. The difference in sorption efficiency between the pyrite surface and goethite surface reflects either: 1. (1) the lack of oxidizable groups on the goethite surface which could reduce dissolved Au(I) species to elemental gold; or 2. (2) the stability of the Au-S bond formed on the sulfide surface compared to the Au-O bond formed on the oxide surface. Based on the results of this study, it is predicted that fine-grained pyrite particles may reach ore-grade Au concentrations (i.e., 1–10 μg g−1 Au) if they are continuously exposed to a gold-bearing solution containing at least 2 ng L−1 gold. Growth of pyrite during gold sorption may explain the common occurrence of invisible gold in pyrite. Goethite, on the other hand, cannot reach ore-grade Au concentrations unless the gold concentration in the gold-bearing solution is higher than 2 μg L−1, which is higher than gold concentrations in natural solutions.
Local Effects on of Solid Rocket Motor Exhaust on Stratospheric Ozone

Solid rocket motor (SRM) exhaust contains chlorine, an important stratospheric constituent that plays a crucial role in the chemistry of ozone. Models of SRM plume combustion and chemistry suggest that a significant fraction of SRM exhaust chlorine might be in an active form as a result of afterburning reactions and be available for immediate ozone destruction as the plume mixes with the ambient stratosphere. If afterburning does produce free chlorine, the SRMs used by the Titan IV and Space Shuttle have the potential to cause nearly complete ozone loss in regions up to several tens of kilometers in radius, depending on altitude. We present a simulation of SRM exhaust mixing and chemistry that predicts the three-dimensional structure of the prompt local ozone loss during the 8 h following a daytime Titan IV launch. Maps of the loss of the total column ozone abundance show that the maximum loss of about 30% occurs about one hour after launch. Four hours after launch the area of column ozone loss exceeding 8% covers up to 2000 km. The shape and severity of the ozone-depleted region depends only slightly on the interaction between launch trajectory and stratospheric winds. Solar ultraviolet flux on the ground beneath the plume changes in response to decreased ozone absorption, alumina scattering, and absorption by chlorine oxide compounds. The ultraviolet flux increases by 100% at 295 nm, shows no change near 300 nm, and decreases by 30% longward of 310 nm. Existing space instrumentation does not possess the spatial resolution required to measure ozone depletion of the size and magnitude predicted following launches involving large SRMs.
Weak interactions of ultra heavy fermions

Abstract We study the weak interactions of ultra heavy fermions, their scattering at high energies and the renormalization corrections they induce at low energies.
The effect of antimycin on the b-cytochromes of plant mitochondria. Oxidation-reduction behavior of cytochrome b-566

Abstract Antimycin plus O 2 increases the reducibility of cytochrome b -566 in plant mitochondria to an extent consistent with an increase of over 110 mv in the apparent midpoint potential of b -566. Enhanced reduction of b -566 is relaxed following consumption of O 2 , but contrary to previous reports this relaxation does not show a close kinetic correlation with reduction of cytochrome c 1 . Experiments with cyanide-inhibited mitochondria demonstrate that neither active cytochrome oxidase nor extensive oxidation of cytochrome c 1 is required for enhancement of b -566 reduction.
Selected contribution: Effects of aging on cerebrovascular tone and [Ca2+]i.

The lower limits of cerebral blood flow autoregulation shift toward high pressures in aged compared with young rats. Intraluminal pressure stimulates contractile mechanisms in cerebral arteries tha...
Astrophysical Exclusion of Photon-Neutrino Weak Coupling

The photon-neutrino coupling theory of weak interactions as presented by Bandyopadhyay is definitely excluded by the astrophysical data for white dwarfs. Furthermore, it is impossible to adjust the photon-neutrino coupling constant so as to reproduce simultaneously the pertinent astrophysical data for white dwarfs and red supergiants.
ESTIMATING CAPACITY LOADINGS FROM WORKCENTER ARRIVAL AND DEPARTURE EVENTS

Abstract Manufacturing firms rely on automatic data collection systems to replace labor-intensive data collection methods. Most systems concentrate on locating and counting parts without regard to transaction times; however, by capturing and processing event times, additional system characteristics can be inferred. Using product arrival and departure event transactions based on bar code technology, this research develops a methodology for estimating the amount of workload in a workcenter with a parallel server structure commonly found in practice. This paper presents an evaluation of the accuracy and precision of the resulting workload estimators under conditions of varying product mix. It was found that the relative proportion of products in the production mix can have a significant effect on estimator performance. For production mixes that change infrequently, the estimator was within 5% of the true workcenter load in 98% of the experiments. The estimator is simple and can be continually updated as new data are collected. This research illustrates the value-added benefits to be gained in utilizing bar code timing information for developing estimates of workcenter load especially within computer-automated shop floor control systems.
INSTRUMENTALITY THEORY AND EQUITY THEORY AS COMPLEMENTARY APPROACHES IN PREDICTING THE RELATIONSHIP OF LEADERSHIP AND TURNOVER AMONG MANAGERS

Abstract Traditional approaches to the investigation of leadership within formal organizations have employed an Average Leadership Style (ALS) model. This model views the behavior of the person in the formally designated position of leader toward the members of his unit in general as the critical input determining the organizational effectiveness of his unit. An alternative to this average leadership style approach called the Vertical Dyad Linkage (VDL) model was presented and investigated. Employing this VDL model, it was found that Equity Theory and Instrumentality Theory, though often presented as alternative approaches to the explanation of human behavior in organizations, may be quite complementary in their predictive capabilities. The key role of the leader in working through the vertical dyad linkages to establish the necessary conditions for instrumentality theory or equity theory is suggested and discussed.
Effects of an intervention to improve communication about end-of-life care among African Americans with chronic kidney disease

Abstract The prevalence of and mortality from chronic kidney disease (CKD) are high among African Americans. Interventions to improve knowledge of the likely illness course and the benefits and risks of life-sustaining treatment at the end-of-life are needed for African Americans with CKD and their surrogate decision makers. Nineteen African Americans with stage 5 CKD and their surrogates were randomized to either patient-centered advance care planning (PC-ACP) or usual care. PC-ACP dyads showed greater improvement in congruence in end-of-life treatment preferences ( p p
A new species of Tychobythinus Ganglbauer, 1896 (Coleoptera: Staphylinidae: Pselaphinae) from Turkey.

A new species of the genus Tychobythinus Ganglbauer, 1896, Tychobythinus oculatus sp. n., is described from near Koycegiz, Mugla Province, in southwestern Turkey. The new species is morphologically closely related to Tychobythinus abnormipes Reitter, 1910, and Tychobythinus pauper Kiesenwetter, 1858, but can be readily distinguished from both by having very simplified internal armature of the aedeagus, and by the specific shape of the gular depression.
Evolution of Process Safety Management

AbstractA process is any activity or combination of activities including any use, storage, manufacturing, handling or on-site movement of hazardous chemicals. Hazards include toxic, reactive, flammable or explosive properties of chemicals which are absolutely inherent. It has been observed that the majority of process safety incidents could have been avoided by practising strong and proper management controls such as: imparting adequate training and job knowledge to new staff under the supervision of experienced staff; adequate understanding of safety information, up-to-date operating conditions, emergency response and control plans; adequate inspection and maintenance programmes; and well supervised and adequately designed modification(s) of equipment(s). Process safety, however, needs strong integration with general safety principles which include influencing behaviour. By describing the evolution of process safety management (PSM) in industry over a period of time, this paper provides an insight into i...
Near-ML multiuser detection

The prohibitive -exponential in the number of users- computational complexity of the maximum likelihood (ML) multiuser detector for direct-sequence code-division-multiple-access (DS/CDMA) communications has fueled an extensive research effort for the development of low complexity multiuser detection alternatives. Notable examples are the zero-forcing (``decorrelating'') and minimum-mean-square-error (MMSE) linear filter receivers. In this paper, we show that we can efficiently and effectively approach the error rate performance of the optimum multiuser detector as follows. We utilize a multiuser zero-forcing or MMSE filter as a pre-processor whose output magnitude provides a reliability measure for each user bit decision. An ordered reliability-based error search sequence of length linear to the number of users returns the most likely user bit vector among all visited options. Numerical and simulation studies for moderately loaded systems that permit the exact implementation of the optimum detector indicate that the error rate performance of the optimum and the proposed detector are nearly indistinguishable. Similar studies for higher user loads (that prohibit comparisons with the optimum detector) demonstrate error rate performance gains of orders of magnitude in comparison with straight decorrelating or MMSE multiuser detection.© (2001) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Polyanhydrides: the effects of ring substitution changes on polymer properties

We synthesized polymers that overcome the processing problems associated with aromatic polyanhydrides. In this paper, we focus on the synthesis and characterization of ortho-substituted polyanhydrides, poly[1,3-bis(o-carboxyphenoxy)propane anhydride] (o-CPP) and poly[1,6-bis(o-carboxyphenoxy)hexane anhydride] (p-CPH). By lengthening the alkyl chain between aryl groups (from propane to hexane) and changing the ring substitution pattern from para- to ortho-, we observed enhanced solubility of aromatic polyanhydrides. Ultimately, these polyanhydrides may be useful as polymer scaffolds for use as functional soft tissue substitutes.
Renal injury during shock wave lithotripsy is significantly reduced by slowing the rate of shock wave delivery.

OBJECTIVE To assess the tissue protection afforded by simply reducing the rate of shock wave (SW) delivery, compared with studies in the pig in which SW lithotripsy (SWL)-induced vascular damage was significantly reduced by initiating treatment using low-amplitude SWs. MATERIALS AND METHODS Juvenile pigs (6–7 weeks old) were treated with an unmodified lithotripter (HM3, Dornier Medical Systems, Kennesaw, GA) at either 120 or 30 SW/min. Treatment was to one kidney per pig, with SWs (2000, 24 kV) directed to a lower-pole calyx. After treatment, parenchymal haemorrhage was determined morphometrically and expressed as percentage of functional renal volume (%FRV). RESULTS Kidneys treated at 120 SW/min had focal to extensive subcapsular haematomas. Parenchymal lesions were found only at the lower pole, but included regions within renal papillae and the cortex. Occasionally, damage extended across the full thickness of the kidney. The lesion in the pigs treated at 120 SW/min occupied a mean (sd) of 4.6 (1.7) %FRV. Kidneys of pigs treated at 30 SW/min showed no surface bleeding. Parenchymal haemorrhage was limited to papillae within the focal volume, and measured 0.08 (0.02) %FRV, a significant (P < 0.005) reduction in injury. CONCLUSIONS Slowing the rate of delivery to 30 SW/min has a dramatic protective effect on the integrity of the kidney vasculature. This finding in our established pig model suggests a potential strategy to improve the safety of lithotripsy. As it was shown that a reduced SW rate also improves the efficiency of stone fragmentation, a slow rate appears to be a means to improve both the safety and efficacy of SWL.
From protectionism to free trade fever? Recent reforms in developing countries

During the 1980s, increasing numbers of developing countries unilaterally liberalized their trade regimes. This paper presents an overview of this dramatic shift from protectionism toward freer trade. South Asia, Latin America, and East Asia have implemented extensive reforms, yet each region has shown a distinct difference in approach and in the degree of liberalization actually achieved. Latin America stands out as moving sharply toward the level of openness of the East Asian Newly Industrialized Countries (NICs). Only in Africa is there little progress toward freer trade.
Parathyroid adenomas: Identified by ct scan

Abstract Parathyroid adenomas in the neck and mediastinum can be identified by computed tomography. Case material has been presented to document this and to further illustrate the usefulness of CT selected problem patients. CT is recommended for precise localization of these adenomas in individuals who are greater operative risks than normal and in patients who have recurrence of disease following subtotal parathyroidectomy.
A study of lifting tasks performed on laterally slanted ground surfaces

Lifting in most industrial environments is performed on a smooth, level ground surface. There are, however, many outdoor work environments (e.g. agriculture and construction) that require manual material handling activities on variable grade ground surfaces. Quantifying the biomechanical response while lifting under these conditions may provide insight into the aetiology of lifting-related injury. The aim of the current study was to quantify the effect of laterally slanted ground surfaces on the biomechanical response. Ten subjects performed both isometric weight-holding tasks and dynamic lifting exertions (both using a 40% of max load) while standing on a platform that was laterally tilted at 0, 10, 20 and 30° from horizontal. As the subject performed the isometric exertions, the electromyographic (EMG) activity of trunk extensors and knee extensors were collected and during the dynamic lifting tasks the whole body kinematics were collected. The whole body kinematics data were used in a dynamic biomechan...
Revisiting First-Year College Students' Mattering: Social Support, Academic Stress, and the Mattering Experience

In this study, Nancy Schlossberg's (1989) theory of college students' mattering to others was revisited. Mattering is the experience of others depending on us, being interested in us, and being concerned with our fate. The relationships of gender, mattering to college friends and the college environment, and friend and family social support with academic stress of 533 first-year undergraduates were examined. Female students reported higher levels of family support, mattering to friends, mattering to their college, and academic stress. Regardless of gender, college friend social support was the most powerful predictor of mattering; mattering to the college was the most powerful predictor of academic stress levels. Research-informed implications for reducing first-year students' academic stress and enforcing their social support and experiences of mattering are discussed.
Introducing Life Science Doctoral Students in Oz to the Wizardry of Computational Modeling: Introducing Computational Thinking with CellDesigner™

Abstract A five-day, hands-on workshop was held at Monash University to introduce doctoral students in the life sciences to computational applications for research. Although three software tools were employed (CellDesigner™, MATLAB™ including the Parallel Computing Toolbox, and Nimrod), this paper reports on the use of CellDesigner in teaching computational thinking and modeling, including system dynamics and regulatory networks. Each session included a series of brief orientations to the tool, followed with illustrative, practical projects for participants to implement. From written evaluations and various forms of anecdotal evidence (e.g., oral communications, participation, project/assignment performance), we conclude CellDesigner to be a suitable tool for use in such a workshop.
Comparative studies on the proteolysis of fixed gelatin membranes by mammalian sperm acrosomes.

The acrosomes of mammalian spermatozoa contain a proteolytic enzyme which may be of importance for fertilization. The release and activity of the enzyme can be visualized directly when the spermatozoa are applied to fixed gelatin membranes. The purpose of this study was to determine the pattern of enzyme release from the spermatozoa of a variety of mammalian species. Thin, transparent membranes of pure gelatin were prepared on microscope slides and fixed in glutaraldehyde. Spermatozoa were applied to the membranes and their proteolytic behavior observed under dark-medium phase objectives at 37°C. In all the species examined (rabbit, bull, hamster, rat, guinea pig and man) extensive depolymerization of the gelatin substrate occurred around the sperm heads. With the exception of human spermatozoa, the onset of proteolysis was clearly identified with the posterior half of the acrosome. In the case of human spermatozoa, no such distinction could be made. It is suggested that the proteolytic enzyme of most mammalian spermatozoa is located in the posterior segment of the acrosome.
Ecto-5′-nucleotidase (CD73) regulation by hypoxia-inducible factor-1 mediates permeability changes in intestinal epithelia

Under conditions of limited oxygen availability (hypoxia), multiple cell types release adenine nucleotides in the form of ATP, ADP, and AMP. Extracellular AMP is metabolized to adenosine by surface-expressed ecto-5′-nucleotidase (CD73) and subsequently activates surface adenosine receptors regulating endothelial and epithelial barrier function. Therefore, we hypothesized that hypoxia transcriptionally regulates CD73 expression. Microarray RNA analysis revealed an increase in CD73 and ecto-apyrase CD39 in hypoxic epithelial cells. Metabolic studies of CD39/CD73 function in intact epithelia revealed that hypoxia enhances CD39/CD73 function as much as 6 ± 0.5‐fold over normoxia. Examination of the CD73 gene promoter identified at least one binding site for hypoxia-inducible factor-1 (HIF-1) and inhibition of HIF-1α expression by antisense oligonucleotides resulted in significant inhibition of hypoxia-inducible CD73 expression. Studies using luciferase reporter constructs revealed a significant increase in activity in cells subjected to hypoxia, which was lost in truncated constructs lacking the HIF-1 site. Mutagenesis of the HIF-1α binding site resulted in a nearly complete loss of hypoxia-inducibility. In vivo studies in a murine hypoxia model revealed that hypoxia-induced CD73 may serve to protect the epithelial barrier, since the CD73 inhibitor α,β-methylene ADP promotes increased intestinal permeability . These results identify an HIF-1‐dependent regulatory pathway for CD73 and indicate the likelihood that CD39/CD73 protects the epithelial barrier during hypoxia.
Monte carlo simulations of a semi-flexible polymer chain : A first glance

We present preliminary results for Monte Carlo simulations of a three dimensional semi-flexible polymer chain with continuous monomer positions. In these simulations, standard Metropolis Monte Carlo methods are used to examine the basic properties of the model, such as equilibration configurations, overall size, and transition temperatures.
Some Perspectives on the Study on Time Use

Over the last several decades, social scientists have begun to pay much more attention to the amounts and patterns of time use among households. What is probably the most important objective is to supplement our measures of overall well-being by adding to the conventional GNP measures of market produced goods and services the well-being associated with household produced goods and services, as well as the well-being asso ciated with the intrinsic satisfactions associated with all of the activities that the household is involved in. It is widely agreed by economists that the standard measure of well-being (the value of market work plus the value of leisure) is seriously deficient, but there is much less agreement about the best way to measure intrinsic satisfactions. Although there are some conceptual problems with the valuation of market goods and services, the main measurement issues have to do with the valuation of the intrinsic satisfactions from both market and non-market activities. Some studies have called these satisfactions "process benefits" and measured them by the set of survey questions shown below:
Histogram refinement for content-based image retrieval

Color histograms are widely used for content-based image retrieval. Their advantages are efficiency, and insensitivity to small changes in camera viewpoint. However, a histogram is a coarse characterization of an image, and so images with very different appearances can have similar histograms. We describe a technique for comparing images called histogram refinement, which imposes additional constraints on histogram based matching. Histogram refinement splits the pixels in a given bucket into several classes, based upon some local property. Within a given bucket, only pixels in the same class are compared. We describe a split histogram called a color coherence vector (CCV), which partitions each histogram bucket based on spatial coherence. CCVs can be computed at over 5 images per second on a standard workstation. A database with 15,000 images can be queried using CCVs in under 2 seconds. We demonstrate that histogram refinement can be used to distinguish images whose color histograms are indistinguishable.
Advances in standardization of laboratory measurement procedures: implications for measuring biomarkers of folate and vitamin B-12 status in NHANES

Population studies such as NHANES analyze large numbers of laboratory measurements and are often performed in different laboratories using different measurement procedures and over an extended period of time. Correct clinical and epidemiologic interpretations of the results depend on the accuracy of those measurements. Unfortunately, considerable variability has been observed among assays for folate, vitamin B-12, and related biomarkers. In the past few decades, the science of metrology has advanced considerably, with the development of improved primary reference measurement procedures and high-level reference materials, which can serve as the basis for accurate measurement. A rigorous approach has been established for making field methods traceable to the highest-level reference measurement procedures and reference materials. This article reviews some basic principles of metrology and describes their recent application to measurements of folate and vitamin B-12.
Sequence mining and transcript profiling to explore cyst nematode parasitism

Cyst nematodes are devastating plant parasites that become sedentary within plant roots and induce the transformation of normal plant cells into elaborate feeding cells with the help of secreted effectors, the parasitism proteins. These proteins are the translation products of parasitism genes and are secreted molecular tools that allow cyst nematodes to infect plants. We present here the expression patterns of all previously described parasitism genes of the soybean cyst nematode, Heterodera glycines, in all major life stages except the adult male. These insights were gained by analyzing our gene expression dataset from experiments using the Affymetrix Soybean Genome Array GeneChip, which contains probeset sequences for 6,860 genes derived from preparasitic and parasitic H. glycines life stages. Targeting the identification of additional H. glycines parasitism-associated genes, we isolated 633 genes encoding secretory proteins using algorithms to predict secretory signal peptides. Furthermore, because some of the known H. glycines parasitism proteins have strongest similarity to proteins of plants and microbes, we searched for predicted protein sequences that showed their highest similarities to plant or microbial proteins and identified 156 H. glycines genes, some of which also contained a signal peptide. Analyses of the expression profiles of these genes allowed the formulation of hypotheses about potential roles in parasitism. This is the first study combining sequence analyses of a substantial EST dataset with microarray expression data of all major life stages (except adult males) for the identification and characterization of putative parasitism-associated proteins in any parasitic nematode. We have established an expression atlas for all known H. glycines parasitism genes. Furthermore, in an effort to identify additional H. glycines genes with putative functions in parasitism, we have reduced the currently known 6,860 H. glycines genes to a pool of 788 most promising candidate genes (including known parasitism genes) and documented their expression profiles. Using our approach to pre-select genes likely involved in parasitism now allows detailed functional analyses in a manner not feasible for larger numbers of genes. The generation of the candidate pool described here is an important enabling advance because it will significantly facilitate the unraveling of fascinating plant-animal interactions and deliver knowledge that can be transferred to other pathogen-host systems. Ultimately, the exploration of true parasitism genes verified from the gene pool delineated here will identify weaknesses in the nematode life cycle that can be exploited by novel anti-nematode efforts.
Genetic Influences on Physiological and Subjective Responses to an Aerobic Exercise Session among Sedentary Adults

Objective. To determine whether genetic variants suggested by the literature to be associated with physiology and fitness phenotypes predicted differential physiological and subjective responses to a bout of aerobic exercise among inactive but otherwise healthy adults. Method. Participants completed a 30-minute submaximal aerobic exercise session. Measures of physiological and subjective responding were taken before, during, and after exercise. 14 single nucleotide polymorphisms (SNPs) that have been previously associated with various exercise phenotypes were tested for associations with physiological and subjective response to exercise phenotypes. Results. We found that two SNPs in the FTO gene (rs8044769 and rs3751812) were related to positive affect change during exercise. Two SNPs in the CREB1 gene (rs2253206 and 2360969) were related to change in temperature during exercise and with maximal oxygen capacity (VO2 max). The SLIT2 SNP rs1379659 and the FAM5C SNP rs1935881 were associated with norepinephrine change during exercise. Finally, the OPRM1 SNP rs1799971 was related to changes in norepinephrine, lactate, and rate of perceived exertion (RPE) during exercise. Conclusion. Genetic factors influence both physiological and subjective responses to exercise. A better understanding of genetic factors underlying physiological and subjective responses to aerobic exercise has implications for development and potential tailoring of exercise interventions.
Complexities in transplant revenue management.

Numerous payment methodologies, contract types, and income reimbursement methods exist in the highly complex environment of transplantation. A fundamental understanding of the transplant environmen...
Endothelin-1 and Vascular Tone in Subjects With Atherogenic Risk Factors

Endothelin-1 (ET-1) is a potent vasoconstrictor that increases vascular tone in the resistance vessels of subjects with hypertension. It is unclear whether endogenous ET-1 affects resistance-vessel function equally in patients with other cardiovascular risk factors. Vasoconstriction to ET-1 is mediated principally via the endothelin-A (ET A ) receptor on vascular smooth muscle cells. Accordingly, we used an ET A -specific antagonist, BQ-123, to test the hypothesis that endogenous ET-1 increases vascular resistance selectively in subjects with hypertension compared with other risk factors. BQ-123 was infused at 100 nmol/min for 80 minutes into the brachial artery of 10 subjects with hypertension (mean±SEM arterial pressure, 106±5 mm Hg), 12 subjects with hypercholesterolemia (mean±SEM total cholesterol, 7.1±0.2 mmol/L), 10 active smokers (mean±SEM, 42±11 pack-years), and 11 healthy, age-matched individuals. Forearm blood flow (FBF) was measured by venous occlusion plethysmography. BQ-123 dilated resistance arterioles in hypertensive subjects, with FBF’s increasing by 46±7% from baseline ( P P P =0.007) individuals but did not affect FBF significantly in smokers (10±8%, P =0.185). The vasodilator response in hypertensive subjects, but not in hypercholesterolemic patients or smokers, was significantly greater than that in healthy individuals ( P =0.012). Endogenous ET-1, acting via the ET A receptor, increases resistance-vessel tone in subjects with hypertension more than in subjects with hypercholesterolemia or in smokers. These results indicate that ET-1 contributes more to the pathophysiology of hypertension than of other risk factors in subjects without overt atherosclerosis.
The preterm prediction study: elevated cervical ferritin levels at 22 to 24 weeks of gestation are associated with spontaneous preterm delivery in asymptomatic women.

Abstract OBJECTIVE: Low serum ferritin levels correlate with low iron stores, whereas high levels are associated with an acute-phase reaction. Our objective was to determine whether elevated levels of ferritin in the genital tract may be a potent marker to identify patients at risk for spontaneous preterm delivery. STUDY DESIGN: We performed a nested case-control study involving 182 women who had spontaneous preterm delivery and 182 term control subjects matched for race, parity, and recruitment center, and selected from 2929 women enrolled in the Preterm Prediction Study of the National Institute of Child Health and Development Maternal-Fetal Medicine Units Network. Cervical fluid ferritin was measured by use of radioimmunoassay. RESULTS: Cervical ferritin levels were significantly higher in women who subsequently had spontaneous early preterm delivery ( P =.002; and P =.004) than in term controls. A cervical ferritin of >75th percentile in the controls (>35.5 ng/mL) was found in 52.9% (9/17) of the women delivered CONCLUSIONS: Elevated cervical ferritin levels at 22 to 24 weeks of gestation in asymptomatic women are associated with subsequent spontaneous preterm birth. The strong correlation of cervical ferritin with other inflammatory markers provides support for the hypothesis of infection as a mediator of preterm delivery. (Am J Obstet Gynecol 2002;186:458-63.)
Morphology of the ring current derived from magnetic field observations

Abstract. Our examination of the 20 years of magnetospheric magnetic field data from ISEE, AMPTE/CCE and Polar missions has allowed us to quantify how the ring current flows and closes in the magnetosphere at a variety of disturbance levels. Using intercalibrated magnetic field data from the three spacecraft, we are able to construct the statistical magnetic field maps and derive 3-dimensional current density by the simple device of taking the curl of the statistically determined magnetic field. The results show that there are two ring currents, an inner one that flows eastward at ~3 RE and a main westward ring current at ~4–7 RE for all levels of geomagnetic disturbances. In general, the in-situ observations show that the ring current varies as the Dst index decreases, as we would expect it to change. An unexpected result is how asymmetric it is in local time. Some current clearly circles the magnetosphere but much of the energetic plasma stays in the night hemisphere. These energetic particles appear not to be able to readily convect into the dayside magnetosphere. During quiet times, the symmetric and partial ring currents are similar in strength (~0.5MA) and the peak of the westward ring current is close to local midnight. It is the partial ring current that exhibits most drastic intensification as the level of disturbances increases. Under the condition of moderate magnetic storms, the total partial ring current reaches ~3MA, whereas the total symmetric ring current is ~1MA. Thus, the partial ring current contributes dominantly to the decrease in the Dst index. As the ring current strengthens the peak of the partial ring current shifts duskward to the pre-midnight sector. The partial ring current is closed by a meridional current system through the ionosphere, mainly the field-aligned current, which maximizes at local times near the dawn and dusk. The closure currents flow in the sense of region-2 field-aligned currents, downward into the ionosphere near the dusk and upward out of the ionosphere near the dawn. Key words. Magnetospheric physics (current systems; storms and substorms; magnetospheric configuration and dynamics)
Biomarker discovery using targeted maximum-likelihood estimation: application to the treatment of antiretroviral-resistant HIV infection.

SUMMARY Researchers in clinical science and bioinformatics frequently aim to learn which of a set of candidate biomarkers is important in determining a given outcome, and to rank the contributions of the candidates accordingly. This article introduces a new approach to research questions of this type, based on targeted maximum-likelihood estimation of variable importance measures. The methodology is illustrated using an example drawn from the treatment of HIV infection. Specifically, given a list of candidate mutations in the protease enzyme of HIV, we aim to discover mutations that reduce clinical virologic response to antiretroviral regimens containing the protease inhibitor lopinavir. In the context of this data example, the article reviews the motivation for covariate adjustment in the biomarker discovery process. A standard maximum-likelihood approach to this adjustment is compared with the targeted approach introduced here. Implementation of targeted maximum-likelihood estimation in the context of biomarker discovery is discussed, and the advantages of this approach are highlighted. Results of applying targeted maximum-likelihood estimation to identify lopinavir resistance mutations are presented and compared with results based on unadjusted mutation‐outcome associations as well as results of a standard maximum-likelihood approach to adjustment. The subset of mutations identified by targeted maximum likelihood as significant contributors to lopinavir resistance is found to be in better agreement with the current understanding of HIV antiretroviral resistance than the corresponding subsets identified by the other two approaches. This finding suggests that targeted estimation of variable importance represents a promising approach to biomarker discovery. Copyright q 2008 John Wiley & Sons, Ltd.