cssi/SciSciGPT-SciSciNet huggingface dataset:
Diastolic myocardial vibrations caused by poststenotic coronary flow instabilities

It has been previously reported in the literature that high-frequency diastolic heart murmurs in the myocardium occur in patients with coronary artery stenoses. It has also long been hypothesized that these murmurs are caused by flow instabilities downstream of the stenosis; the most obvious mechanism for this phenomenon is that pressure fluctuations due to the flow transition excite vibrations in the coronary artery wall which then radiate into the myocardium. A prior pilot study [1], utilizing Doppler vibrometry, an ultrasound based technique, was able to measure high frequency (100–1000Hz) but low amplitude (1–10μm) left ventricular wall vibrations in patients with coronary artery stenosis. Furthermore, the intensity of the wall vibrations was shown to significantly correlate with the percent stenosis (as determined by quantitative coronary angiography). This evidence suggests that ultrasound doppler vibrometry offers the possibility to detect coronary artery stenosis with a low-cost, relatively cheap, and non-invasive modality [2]. This particular study, therefore, seeks to quantify the relationship between the poststenotic flow instabilities and wall vibrations in order to optimize the vibrometry measurements.Copyright © 2012 by ASME
A Novel Inorganic Aqueous Solution and its Effect on Liquid Spreading and Freeze/Thaw Processes

Frozen startup of phase change heat transfer devices is a complex problem that can have a large impact on heat transfer systems. A patented novel working fluid developed at UCLA comprised of an inorganic aqueous solution (IAS) was investigated for potential effects on the freeze/thaw capabilities in phase change heat transfer devices by examining the melting process of droplets. Preliminary visual tests were conducted to gain insight into any physical processes that surface augmentation created by this fluid may have on the freezing and melting process. These tests demonstrated significant differences in liquid spreading, the melting process, and the melting rate of droplets on surfaces pre-treated with IAS. Contact angle measurements exhibited enhanced wetting properties. SEM images of frozen droplets showed that liquid freezes in the small capillary wick formed by the initial evaporation of IAS. Video of melting droplets showed a significant increase in melting rate when the surface was first treated with IAS due to superior liquid spreading.© 2013 ASME
The evaluation of quantitative autoradiogram processing systems for cerebrovascular research.

Abstract The development of an image processing system for quantitative autoradiography (QAR) is described, with emphasis on the evaluation of image digitization systems independent of hardware or software design. Each step of converting the autoradiographic image to a functional image of a physiological variable such as local cerebral blood flow (LCBF) or local cerebral glucose utilization rate (LCGU) is evaluated. The autoradiograms are digitized, aligned, transformed to a tissue tracer concentration image based on the gray value (GV) of calibrated 14C standards, subtracted from each other as required in double tracer QAR, and converted to an LCBF or LCGU image using the proper tracer kinetic model. Geometric size, mean and standard deviation of the LCBF, LCGU, and tracer concentration can be measured in regions of interest. These steps are evaluated separately for their contribution to the accuracy and precision of the final, functional image. The qualities important in the final image are spatial resolution, intensity linearity, and intensity sensitivity, as well as the noise level. Techniques for evaluating the LCBF image include: (1) optimization of the input linearity and dynamic range of the video camera to maximize relative intensity sensitivity of the final functional image; (2) visual inspection of the curves used to fit various functions that are important in the conversion of the GV image to an image of physiological interest; (3) consideration of the noise introduced by the input devices and during the image conversion; and (4) above all, the integration of the various parts of the system to produce an accurate image useful in cerebrovascular research.
What does a clinical competency curriculum look like

This article describes how a competency-based curriculum is implemented at the Warren Alpert Medical School of Brown University. A competency-based curriculum can be implemented in either a traditional discipline-oriented curriculum or an integrated, case-based curriculum. Restructuring learning activities, assuring adequate numbers of faculty, and training faculty to assess competencies are essential for success. Schools of veterinary medicine must ensure that their graduates possess a wide range of abilities, in additional to scientific knowledge, if they are to practice successfully. A competency-based curriculum is the best means to do so.
Synthesis and Properties of F-Containing Poly(diphenylacetylene) Membranes

The polymerization of various silyl- and F-containing diphenylacetylenes (1a−k) with TaCl5−n-Bu4Sn provided high-molecular-weight polymers. Most polymers (2a−d, 2g, and 2h) were totally soluble in common organic solvents and afforded tough free-standing membranes by casting from toluene solution, while some polymers (2e, 2f, and 2i−k) were insoluble in any organic solvents. The onset temperatures of weight loss of polymers 2a−d in air were over 400 °C, indicating very high thermal stability. The membranes of 2a−d were desilylated with trifluoroacetic acid to give desilylated polymer membranes 3a−d, which were insoluble in any solvents. The fractional free volumes (FFV) of the present membrane-forming trimethylsilyl and/or F-bearing polymers (2a−d and 3a−d) were ca. 0.28−0.31 and appreciably large, and they showed very high permeability (ca. 1400−14 000 barrers) to the six gases examined. The oxygen permeability coefficient (PO2) of 2a was as high as 2900 barrers, which is about twice that of poly[1-(p-tri...
Where Has All the Road Kill Gone

Summary An estimated 80 million birds are killed by colliding with vehicles on U. S. roads each year [1], and millions more die annually in Europe [2] and elsewhere. Losses to vehicles are a serious problem for which various changes in roadway design and maintenance have been proposed [3]. Yet, given the magnitude of the mortality reported for some species [4], we might expect natural selection to favor individuals that either learn to avoid cars or that have other traits making them less likely to collide with vehicles. If so, the frequency of road kill should decline over time. No information is available for any species on whether the extent of road-associated mortality has changed [2]. During a 30-year study on social behavior and coloniality of cliff swallows ( Petrochelidon pyrrhonota ) in southwestern Nebraska, we found that the frequency of road-killed swallows declined sharply over the 30 years following the birds' occupancy of roadside nesting sites and that birds killed on roads had longer wings than the population at large.
MULTIPLY CONNECTED BOSE-EINSTEIN-CONDENSED ALKALI-METAL GASES: CURRENT-CARRYING STATES AND THEIR DECAY

The ability to support metastable current-carrying states in multiply connected settings is one of the prime signatures of superfluidity. Such states are investigated theoretically for the case of trapped Bose condensed alkali-metal gases, particularly with regard to the rate at which they decay via thermal fluctuations. The lifetimes of metastable currents can be either longer or shorter than experimental time scales. A scheme for the experimental detection of metastable states is sketched.
Positive Illusions: Positively Correlated with Subjective Well-Being, Negatively Correlated with a Measure of Personal Growth:

Psychologists have long debated the benefits and costs of self-deceptive enhancement or positive illusions. Accurate perception of reality is central to the definitions of mental health proposed by many personality and clinical psychologists, but Taylor and Brown have suggested that having positive illusions is associated with increased happiness and satisfaction with life. One explanation for the conflicting assertions is that mental health, broadly defined, includes both subjective well-being and personal growth, distinguishable factors which are differentially related to positive illusions. For this study, 81 college students completed measures of positive illusions (Balanced Inventory of Desirable Responding Self-deceptive Positivity and How I See Myself Questionnaire), subjective well-being (Satisfaction With Life Scale and Existential Anxiety Scale), and moral reasoning (Defining Issues Test) as an index of personal growth. As predicted, positive illusion composite scores were positively correlated ...
Confirmation of ovulation and characterization of luteinizing hormone and progesterone secretory patterns in cycling, isosexually housed Bolivian squirrel monkeys (Saimiri boliviensis boliviensis).

In the female Bolivian squirrel monkey a much greater elevation of serum estradiol (E2) was measured after mating than that observed in similary cycling monkeys that did not mate. This raised the possibility that cycling squirrel monkeys may not ovulate during nonmated cycles To test this hypothesis, we performed laparoscopies on nine isosexually housed, cycling monkeys to observe the ovaries after the luteinizing hormone (LH) surge, which was measured by mouse interstitial cell bioassay using LER 1909-2 as the standard. Single ovulatory stigmas were identified as well demarcated, red, punctate depressions at the center of dome-shaped elevations on the ovarian surface in eight monkeys, when laparoscopically examined 9-56 hr after the LH peak. One monkey examined laparoscopically prior to the LH surge had a large translucent cystic follicle, confirming the morphology of the mature prevulatory follicle. Mean progesterone (P) concentrations fell to a nadir 1 day prior to the LH surge and then began to rise on the LH surge. Peak P levels were found 2 days after the LH surge. In the ovulating animals in which periovulatory E2 levels were measured, no value was greater than 800 pg/ml, indicating that the presence of follicular rupture was not sufficient to account for the elevated E2 levels observed after mating. These data confirm ovulation and follicular rupture in the absence of mating and delineate the relationship between periovulatory LH, P, and E2 secretory patterns in cycling squirrel monkeys.
ENDOR study of pentaphenylcyclopentadienyl radicals in solution. Lifting of orbital degeneracy by methyl substitution

An electron-nuclear-double-resonance (ENDOR) study has been made of pentaphenylcyclopentadienyl (PPCPD) and a series of para-methylated PPCPD radicals in liquid solution. The hyperfine splitting (hfs) constants in PPCPD and pentamethyl PPCPD (MPPCPD) do not show a significant π-σ spin delocalization effect. This indicates that the phenyl substituents are twisted less than 60° out of the plane of the five-membered ring. A MO calculation based on σ-π separability using the McLachlan approximation gives good agreement between experimental and theoretical hfs constants for a twist angle of 40°. The ring proton hfs constants in PPCPD and MPPCPD are practically identical, indicating a negligible effect of the methyl groups on the spin density distribution. Moreover, the hfs constants in both radicals are not affected noticeably by temperature variations. The ring proton splittings in the partially methylated PPCPD radicals, on the other hand, vary widely and show a marked temperature dependence. The same is tru...
Bayesian knowledge base tuning

Abstract For a knowledge-based system that fails to provide the correct answer, it is important to be able to tune the system while minimizing overall change in the knowledge-base. There are a variety of reasons why the answer is incorrect ranging from incorrect knowledge to information vagueness to incompleteness. Still, in all these situations, it is typically the case that most of the knowledge in the system is likely to be correct as specified by the expert (s) and/or knowledge engineer (s). In this paper, we propose a method to identify the possible changes by understanding the contribution of parameters on the outputs of concern. Our approach is based on Bayesian Knowledge Bases for modeling uncertainties. We start with single parameter changes and then extend to multiple parameters. In order to identify the optimal solution that can minimize the change to the model as specified by the domain experts, we define and evaluate the sensitivity values of the results with respect to the parameters. We discuss the computational complexities of determining the solution and show that the problem of multiple parameters changes can be transformed into Linear Programming problems, and thus, efficiently solvable. Our work can also be applied towards validating the knowledge base such that the updated model can satisfy all test-cases collected from the domain experts.
Performance analysis of real-time software supporting fault-tolerant operation

Analyzing the performance of real-time control systems featuring mechanisms for online recovery from software faults is discussed. The application is assumed to consist of a number of interacting cyclic processes. The underlying hardware is assumed to be a multiprocessor, possibly with a separate control processor. The software structure is assumed to use design diversity along with forward and/or backward recovery. A detailed but efficiently solvable model for predicting various performance and reliability characteristics is developed. One of the key ideas used in modeling is hierarchical decomposition, which enables computation of level-oriented performance parameters in an efficient manner. The model is general, and adaptable for a number of useful special cases. >
Fluctuation of incoming flux with multiplicative noise on a scale-free network

We study the influence of topology on the dynamical properties of a diffusion process which can be described by a diffusion equation with multiplicative noise on a complex network. From numerical simulations we find that the fluctuation of the incoming mass on a given node of network scales with the average incoming mass, or flux, in a topology-dependent fashion. By combining numerical results with the Langevin equation of the associated process, we show that inhomogeneity of the underlying structure leads to the appearance of distinct dynamical regions in the system and a crossover behavior in the scaling of fluctuations with average flux.
Mapping spin-orbit splitting in strained (In,Ga)As epilayers

Time-resolved and spatially resolved Faraday rotation spectroscopy is used to measure the magnitude and direction of the momentum-dependent spin splitting in strained InGaAs epilayers. The epilayers are coherently strained and therefore designed to reduce inhomogeneous effects related to strain relaxation. Measurements of momentum-dependent spin splitting as a function of electron spin drift velocity along [100], [010], [110], and $[1\overline{1}0]$ directions enable separation of isotropic and anisotropic effective magnetic fields that arise from uniaxial and biaxial strain along $⟨110⟩$. We find that the anisotropic and isotropic strain-induced effective magnetic fields are comparable in magnitude, contrary to previous predictions.
Impact of diet quality on demographic attributes in adult grasshoppers and the nitrogen limitation hypothesis

Various formulations of the nutrient stress hypothesis predict that insect herbivore populations will respond positively to increased nutrient quality of host plants, especially dietary nitrogen. Survival and reproduction by adult females of two grasshopper species (Acrididae; Melanoplus sanguinipes(Fabricius) and Phoetaliotes nebrascensis (Thomas)) were evaluated in response to defined diets that varied factorially in both total nitrogen (1-7%) and total soluble carbohydrate (4.3-26.7%). These grasshopper species coexist naturally but are typically shifted phenologically so that specific developmental stages normally encounter host plants of different nutritional quality under natural conditions. 2. Demographic responses by adult females of both species varied according to diet quality, but not in the same fashion. Diet quality affected survival significantly in P. nebrascensis but not in M. sanguinipes. Survival in P. nebrascensis was greatest on diets containing the lowest nitrogen concentrations; carbohydrate level had no effect. 3. Diet quality influenced reproduction significantly in both species. Egg production rate (eggs/day) in M. sanguinipes exhibited a negative linear response to increased carbohydrate, coupled with a significant quadratic response to nitrogen that reached a maximum at an intermediate level of about 4% total N. A significant quadratic response to total N for pod production rate (indicating the timing of reproduction) was also observed. Clutch size in M. sanguinipes exhibited a negative relationship with total carbohydrate in the diet, but no response to nitrogen. No interaction was observed between nitrogen and carbohydrate levels. For P. nebrascensis, response to diet quality was much weaker, with only a suggestive maximum at 4% total-N for both egg production rate (eggs/day) and clutch size (eggs/pod) and a suggestive linear response for pod production rate as carbohydrate level increased. Female body weight did not contribute to any reproductive response as a covariate variable. 4. Combined with a similar, previous analysis of demographic responses by the grass-feeding grasshopper, Ageneotettix deorum, these results challenge the ability to draw generalizations about host plant nutritional quality and grasshopper demographic responses. These three grasshopper species respond quite differently to defined diets that vary in total nitrogen and carbohydrate levels. Thus, although host plant quality can contribute significantly to grasshopper population responses, a uniform explanation is not likely.
World genera of the leaf-mining sawfly tribe Fenusini (Hymenoptera: Tenthredinidae)

A key is given to the 19 genera of Fenusini, and synonymies and discussions are given for each genus. The tribe Cacosyndiini is synonymized with Fenusini, and Afusa Malaise is a new synonym of Nefusa Ross. The larvae of Fenusini are leaf miners, and species are found throughout the northern hemisphere south to Burma and Nepal in Asia, and in southern South America. Several species have been accidentally introduced to areas outside their native ranges; at least 5 species are adventives in North America.
20-Hydroxyecdysone stimulates RNA polymerase I activity in silkmoth wing epidermis by increased synthesis and phosphorylation.

Abstract The activities of RNA polymerases I and II in the wing epidermis of dispausing silkmoth pupae increased about tenfold during the first day after administration of either 20-hydroxyecdysone (20E) or 20E plus juvenile hormone (Katula et al., 1981a). The aim of these studies was to correlate these increases in RNA polymerase I and II activities to their amounts in hormone stimulated wing epidermis. The enzyme activities were measured by standard procedures while their amounts were determined by the application of a modified ELISA with subunit-specific monoclonal antibodies. Results showed that the increase in the amount of RNA polymerase I during the first 24 h accounted for only about 60% of the increase in activity. Alkaline phosphatase decreased the activity of the newly synthesized enzyme by 40–50%. These results indicate that hormone-stimulation of RNA polymerase I activity is due to a combination of synthesis of the enzyme and phosphorylation of the enzyme and/or tightly associated factors. RNA polymerases II and III determined by differential ELISA using a monoclonal antibody specific to a common subunit followed developmental changes similar to those of RNA polymerase I. The amounts and activity of the enzymes during the first 48 h were similar in wing tissue that followed the second pupal development (20E + juvenile hormone) compared to tissue that developed into adult wings (20E).
Why not routinely use best linear unbiased predictors (BLUPs) as estimates of cholesterol, per cent fat from kcal and physical activity?

Measures of biologic and behavioural variables on a patient often estimate longer term latent values, with the two connected by a simple response error model. For example, a subject's measured total cholesterol is an estimate (equal to the best linear unbiased estimate (BLUE)) of a subject's latent total cholesterol. With known (or estimated) variances, an alternative estimate is the best linear unbiased predictor (BLUP). We illustrate and discuss when the BLUE or BLUP will be a better estimate of a subject's latent value given a single measure on a subject, concluding that the BLUP estimator should be routinely used for total cholesterol and per cent kcal from fat, with a modified BLUP estimator used for large observed values of leisure time activity. Data from a large longitudinal study of seasonal variation in serum cholesterol forms the backdrop for the illustrations. Simulations which mimic the empirical and response error distributions are used to guide choice of an estimator. We use the simulations to describe criteria for estimator choice, to identify parameter ranges where BLUE or BLUP estimates are superior, and discuss key ideas that underlie the results.
Feeding and Nutrition of Lygus hesperus (Hemiptera: Miridae). II. An Estimation of Normal Feeding Rates

Four methods were employed to determine the amounts of food ingested by Lygus hesperus Knight. Three of the methods were satisfactory. (1) By weighing the food source before and after being fed upon, adult males were found to consume an amount equal to 112% of their body weight per 24 hr. (2) When P32 was utilized as a tracer, third-instar nymphs were found to ingest an amount equal to 283% of their initial weight in 24 hr. Expressed as a percentage of body weights, the amounts ingested per unit time decreased as the nymphs matured. (3) A direct estimate of food consumption was obtained when bugs were fed through a Parafilm membrane which sealed the end of a food tube connected to a capillary. By this method, females were found to ingest an amount equal to 169% of their body weight in 24 hr, while males ingested only 98% of theirs.
Patterns of floristic richness in vegetation communities of California: regional scale analysis with multi‐temporal NDVI

Aim Applying water-energy dynamics and heterogeneity theory to explain species richness via remote sensing could allow for the regional characterization and monitoring of vegetation community assemblages and their environment. We assess the relationship of multi-temporal normalized difference vegetation index (NDVI) to plant species richness in vegetation communities. Location California, USA. Methods Sub-regions containing species inventories for chaparral, coastal sage scrub, foothill woodland, and yellow pine forest communities were intersected with a vegetation community map and an AVHRR NDVI time series for 1990, 1991, 1992, 1995 and 1996. Principal components analysis reduced the AVHRR data to three variables representing the sum and temporal trajectories of NDVI within each community. A fourth variable representing heterogeneity was tested using the standard deviation of the first component. Quadratic forms of these variables were also tested. Species richness was analysed by stepwise regression. Results Chaparral, coastal sage scrub, and yellow pine forest had the best relationships between species richness and NDVI. Richness of chaparral was related to NDVI heterogeneity and spring greenness (r2 varied between 0.26 and 0.62 depending on year of NDVI data). Richness of coastal sage scrub was nonlinearly related to annual NDVI and heterogeneity (r2 0.63–0.81), with peak richness at intermediate values. Foothill woodland richness was related to heterogeneity in a monotonic curvilinear fashion (r2 0.28–0.35). Yellow pine forest richness was negatively related to spring greenness and positively related to heterogeneity (r2 0.40–0.46). Main Conclusions While NDVI's relationship to species richness varied, the selection of NDVI variables was generally consistent across years and indicated that spatial variability in NDVI may reflect important patterns in water-energy use that affect plant species richness. The principal component axis that should correspond closely with annual mean NPP showed a less prominent role. We conclude that plant species richness for coarse vegetation associations can be characterized and monitored at a regional scale and over long periods of time using relatively coarse resolution NDVI data.
Enzymatic Modification of Fish Frame Protein Isolate

Protein isolate was hydrolyzed with pepsin yielding an approximate degree of hydrolysis of 80%. Frame protein hydrolysates were then employed for plastein synthesis. Enzyme induced plastein was optimized at: (1) pH 5 for pepsin and pH 7 for alpha-chymotrypsin; (2) substrate concentration, 40% w/v; (3) time of incubation, 24 hr; (4) enzyme/substrate ratio, 1:100 w/w. Percent plastein yields of 33.8 and 27.3 were found for pepsin and alpha-chymotrypsin, respectively, when trichloracetic acid was used as the precipitating agent. However, when plastein was precipitated by ethanol, the percent yield was found to be 46 and 40.5 for pepsin and alpha-chymotrypsin, respectively.
Data clustering by minimizing disconnectivity

Identifying clusters of arbitrary shapes remains a challenge in the field of data clustering. We propose a new measure of cluster quality based on minimizing the penalty of disconnection between objects that would be ideally clustered together. This disconnectivity is based on analysis of nearest neighbors and the principle that an object should be in the same cluster as its nearest neighbors. An algorithm called MinDisconnect is proposed that heuristically minimizes disconnectivity and numerical results are presented that indicate that the new algorithm can effectively identify clusters of complex shapes and is robust in finding clusters of arbitrary shapes.
Acid phosphatase activity in Golgi apparatus and related structures in pars recta of rat kidney studied by thin and semi-thin section cytochemistry.

Using 0.5 μ thick (i.e., semi-thin) and conventional thin sections, observations have been made on the localization of acid phosphatase in the Golgi apparatus and related structures in the pars recta of rat kidney. In thin sections one or two Golgi cisternae located at the concave (basilar) aspect of the stack had enzymic activity. The periphery of these cisternae may be fenestrated. Coated vesicles were seen apparently free in the cytoplasm and in continuity with both reactive Golgi cisternae and smooth tubular elements. Smooth vesicular profiles with electron-lucent matrices and low enzymic activity were seen, apparently free, in the central Golgi zone. Semi-thin sections demonstrated more fully the extent of the reactive Golgi elements, their architecture and their relationships with other organelles. Within a stack the reactive Golgi cisternae were continuous with one another. A network of anastomosing tubular elements formed the periphery of the cisternae and linked some adjacent cisternae. Tubules extended considerable distances from this network in apical and lateral directions. Vesicular protuberances formed ends to the tubular extensions but free vesicles were not obvious. Apparent continuity was seen between reactive tubules and dense bodies (secondary lysosomes). Vesicular profiles with electron-lucent matrices andlow enzymic activity appeared to be continuous with the periphery of reactive Golgi cisternae and may represent the formation of primary lysosomes. This study demonstrates that semi-thin sections could be used to great advantage in the study of organelle interactions in both normal and pathological states.
Abstract A206: Chk1 protects normal cells from HDAC inhibitor-induced cell death.

Histone deacetylase inhibitors (HDACi) are a new class of selective anti-cancer agents that inhibit zinc-dependent histone deacetylases. HDACi in clinical trials have shown anti-cancer activity at well-tolerated doses. The mechanisms of resistance to HDACi are important in developing these agents for cancer therapy. We previously showed that vorinostat induces DNA damage in both transformed and normal cells. Normal cells can repair the DNA damage, while transformed cells cannot and undergo apoptosis and death. This study found Chk1, a component of the G2 checkpoint, protects normal cells from HDACi-induced cell death. Culture with HDAC inhibitor plus Chk1 inhibitor (UCN-01, AZD7762 or CHIR124) killed normal cells, while there was no cell death in culture of normal cells with HDAC inhibitor alone. Chk1 inhibitor also increased cell death of transformed cells cultured with HDACi. In culture with both HDACi and Chk1 inhibitor, mitotic abnormalities which included loss of sister chromatid cohesion and chromosomal disruption were observed in normal and transformed cells. These findings show that intact Chk1 is important for the resistence of normal cells to HDACi and suggest that combined treatment of HDACi with Chk1 inhibitor may cause substantial toxicity. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr A206.
Mechanosensation and transduction in osteocytes

There may be no single mechanoreceptor in osteocytes, but instead a combination of events that has to be triggered for mechanosensation and transduction of signal to occur. Possibilities include shear stress along dendritic processes and/or the cell body, cell deformation in response to strain, and primary cilia. These events could occur independently or simultaneously to activate mechanotransduction. Signal initiators include calcium channel activation and ATP, nitric oxide, and prostaglandin release. Means of signal transfer include gap junctions and hemichannels, and the release of signaling molecules into the bone fluid. Questions remain regarding the magnitude of strain necessary to induce an osteocyte response, how the response propagates within the osteocyte network, and the timing involved in the initiation of bone resorption and/or formation on the bone surface. Mechanical loading in the form of shear stress is clearly involved not only in mechanosensation and transduction, but also in osteocyte viability. It remains to be determined if mechanical loading can also affect mineral homeostasis and mineralization, which are newly recognized functions of osteocytes.
Conditioning of odors in compound with taste: A failure to observe potentiation

In three experiments, rats were presented with odor-alone and compound odor-taste solutions, followed by lithium-chloride-induced illness. Subsequently, aversions to the odor stimuli were assessed. The results do not replicate earlier reports of potentiation of conditioning to odors by taste; greater aversion to the odor conditioned in compound, relative to that conditioned in isolation, was not evidenced for all the conditioned stimuli (CSs) employed. Instead, the outcome appeared to be odor-specific. This was consistently the case, despite manipulations of preexposure, type of taste CS employed, and intensity of odor CSs employed. These results suggest that the odor-taste potentiation phenomenon is more fragile than previously reported.
On combination rules for molecular van der waals potential-well parameters

Combination rules are proposed for the depth and position parameters of the effective potential well for interactions between molecules. They are an extension, by the introduction of a rigid-core parameter that can be determined independently from known dispersion coefficients, of the Tang-Toennies rules for interactions between noble-gas atoms. Such rules permit the calculation of many mixture properties of molecular gases via known correlation equations, without involving any attempt to predict the entire anisotropic intermolecular potential. The rules are tested with the few known potentials, and with more extensive experimental data on mixture properties, and appear to work satisfactorily.
Renal function tests in nonacute recurrent urinary tract infections in children.

Summary The clinical value of various renal function tests in recurrent urinary tract infections in children has been examined. The study also includes an evaluation of glomerular capacity versus tubular capacity in recurrent urinary tract infections. There was no good correlation between blood urea nitrogen concentration and serum creatinine concentration within the normal limits for these two parameters. When blood urea nitrogen concentration and/or serum creatinine concentration were elevated, a highly significant correlation between the two parameters was found. When relating blood urea nitrogen concentration to the clearance of inulin an elevation of blood urea nitrogen concentration was not found until the filtration rate was below 50 ml/min/1.73 m2 b.s. The tubular functions were examined by studies of (a) the concentrating capacity, (b) the diluting capacity, (c) sodium reabsorption and id) renal acid-base regulation. The concentrating capacity was determined by two screening tests, maximal urine osmolality after 19 hours of fluid and food deprivation with or without injection of pitressin tannate, and by free water reabsorption. The administration of exogenous pitressin had no significant effect on maximal urine osmolality. There was a highly significant correlation between free water reabsorption and maximal urine osmolality. A highly significant correlation was also found between free water reabsorption and glomerular filtration rate. Diluting capacity was evaluated by determining minimum urine osmolality and free water clearance. A highly significant correlation between minimum urine osmolality and free water clearance was obtained. There was a good correlation between free water clearance and glomerular filtration rate. When sodium reabsorption is depressed below normal, urine sodium concentration during hydropenia is abnormally low. A normal standard bicarbonate level does not exclude a defect in renal acidifying mechanisms. A defect renal acidifying capacity could be found even in patients with normal filtration rates indicating that renal acidifying capacity might be the first sign of renal damage in children with recurrent urinary tract infections.
Electron paramagnetic resonance of multistable interstitial-carbon-substitutional-group-V-atom pairs in silicon.

A total of five new electron paramagnetic resonance (EPR) centers are observed in electron-irradiated P-, As-, and Sb-doped silicon. Three are identified as arising from the neutral charge state of the stable configuration and two of the four metastable configurations of an interstitial-carbon--substitutional-phosphorus (${\mathrm{C}}_{\mathit{i}}$-${\mathrm{P}}_{\mathit{s}}$) pair, recently discovered by deep level transient capacitance spectroscopy. The other two are identified as arising from the corresponding stable configurations of ${\mathrm{C}}_{\mathit{i}}$-${\mathrm{As}}_{\mathit{s}}$ and ${\mathrm{C}}_{\mathit{i}}$-${\mathrm{Sb}}_{\mathit{s}}$ pairs. Combining unusual uniaxial-stress-alignment results with analysis of the EPR spectra allows detailed models to be proposed for the different defect configurations and for the mechanism of conversion between them. We conclude that the stable state consists of a 〈100〉-split-C--group-V-atom interstitialcy which converts under electronic excitation to the metastable configurations by ejecting the carbon backward toward the nearest ${\mathit{T}}_{\mathit{d}}$ interstitial site from which it forms similar C-Si interstitialcies with its surrounding Si atoms.
A Simplified Combustion Analysis System

Knowledge of the chemical composition of the inlet and exhaust gases of combustion engines aids in evaluating engine performance. Jet engine research requires rapid gas analysis unobtainable by conventional analytical methods. A convenient and rapid gas analysis system which combines thermal conductivity measurements with a chemical analytic scheme and which has been employed extensively on ramjet engines is described. Gases are analyzed for fuel-oxidizer ratio and for chemical composition. With simplifying assumptions, this analysis permits the calculation of other performance data such as combustion efficiency, flame temperature, Mach number, etc.
The rate of growth in progeria, with a report of two cases.

Summary Two children with typical progeria were reported with a brief description of the salient clinical and pathological features of the condition and its progress from all cases described in the literature. All available data from the twenty-two reported cases with regard to growth have been collected, tabulated, and reproduced as graphs. After only slight decreased rate of weight gain during the first year of life, the weight remains almost stationary during the first decade and eventually may reach that of the normal two-to three-year level during the second decade. The height is slightly less retarded and gradually reaches a maximum during the first decade to the normal level of four to five years. Degenerative changes in the vascular system cause death from coronary disease or cerebral infarction in the first or second decades, although two patients have lived a few years longer. Although the etiology of progeria is unknown, the suggestion is made that the unknown factors which produce arrest of growth at normal maturity may be brought into play prematurely from some congenital defect.
An electrophysiological study of descending projections to the lumbar spinal cord in adult male rats

Recent anatomical evidence suggests that descending projections from the lateral vestibular nucleus (LVe) and gigantocellular reticular nucleus (Gi) innervate areas of the lumbar spinal cord near the spinal nucleus of the bulbocavernosus (SNB). To confirm this finding electrophysiologically, we recorded and mapped averaged field potentials within the lumbar spinal cord of male rats in response to electrical stimulation of the LVe or Gi and compared these with the location of averaged field potentials evoked at the same levels by stimulation of SNB axons in the bulbocavernosus (BC) nerve. Stimulation of the LVe or the Gi produced negative field potentials that were largest at sites 200–450 μm dorsolateral to SNB somata. In an attempt to verify that this region innervates SNB motoneurons, the BC motor nerve volley was recorded in response to microstimulation at various depths within the spinal cord. Stimulation of sites dorsolateral and lateral to the SNB somata elicited volleys in the BC nerve that had two components. The onset latency of the earlier component was similar to the antidromic latency of SNB motoneurons to BC nerve stimulation, and the threshold for eliciting this component was lowest at sites in the electrode track near SNB somata. Thus, the earlier component may be evoked by direct stimulation of the SNB motoneurons. The threshold for evoking the later component was lowest at the sites 230–380 μm dorsolateral to SNB somata, suggesting that this component involves activation of other neurons. These results indicate that the LVe and Gi may modulate the activity of SNB motoneurons through interneurons located in a region several hundred microns away from SNB somata.
Radiation Damage in Type II Superlattice Infrared Detectors

The effects of 2 MeV proton irradiation on a set of four long-wave infrared type II superlattice photodiodes with various structures were studied. Changes were monitored in operating bias, quantum efficiency (QE), and dark current. Shifts in operating bias indicate that irradiation causes the superlattices to become more p-type, and decreases in QE are found to be consistent with a reduction in carrier lifetime. Leakage currents remain lower in graded-gap diodes at all fluences.
A New, simple atom reservoir for atomic fluorescence spectrometry

Abstract The disadvantages of flames as atomizers are summarized, and a new, simple and efficient means of atomization of samples is proposed. The solution on a platinum loop is vaporized by electrical heating into an argon stream. Limits of detection were 10-14 g for cadmium, 10-8 g for mercury, and 10-7 g for gallium. Linear calibration graphs were obtained over 3 or 4 orders of magnitude. Of the various sheathing gases studied, argon was most efficient. The method is relatively insensitive to matrix effects.
Screening for family violence: what's an evidence-based doctor to do?

In this issue, Nelson and colleagues found essentially no studies of reasonable quality supporting specific effective intervention for family violence. In light of the evidence, why should clinicia...
The Friction Reduction With a New Two-Piece Spring Retainer Design and Light Weight Valve Train Components in SI Engines

The reduction of friction in the valve train of four-stroke combustion engines is a promising opportunity to decrease fuel consumption and to improve pollutant emissions. The possibilities are reviewed by comparing light weight and newly developed components. The friction in the valve train causes a loss from the BMEP by about 0.2 to 0.4 bar. To measure friction forces in this range requires constant and well maintained environmental conditions. The viscosity as well as the pressure and temperature of the lubricating oil have a big influence on the friction. Due to the valve spring forces a strong fluctuation of the cam torque appears. This makes it very demanding to set up the measurement equipment in a correct way. Measurement equipment which is able to gauge with sufficient accuracy may be overloaded by the effects caused by the spring forces. Based on this special care is necessary during the first ramp up of the cylinder head. It has to be modified to avoid overloading the measurement equipment. One possibility to achieve lower friction between the valve stem and the valve guide is the reduction of the lateral forces which are caused by the asymmetry of the valve spring. Using recently new developed components these detrimental forces within a valve train can be reduced which leads to lower friction losses. In addition the wear between the valve train components can be reduced. In detail this can be accomplished by using two-piece spring retainer which allows a tilted position of the spring end during the valve lift and by this only allow axial forces to act onto the valve. The friction in a valve train using a direct acting mechanical tappet is mainly caused by the sliding contact of the cam on the tappet face. To lower the friction in this area the spring forces have to be reduced. This requires valve train components with lower masses and weaker springs. Therefore valves, spring retainers and tappets made from light weight alloys where developed. The mass of these light weight components could be reduced by more than 50%. Detailed measurements are performed and the results will be presented. As a conclusion it can be seen, what light weight components in the valve train of four stroke engines can contribute to a torque reduction in innovative valve trains.Copyright © 2004 by ASME
Further biochemical characterization of [3H]dihydroazapetine binding to α-adrenoceptor — related proteins from the rat vas deferens

The binding of [3H]dihydroazapetine, a reversible blocker of the α-adrenoceptor, has been characterized in a membrane preparation from the rat vas deferens. Binding is rapid, reversible and shows evidence of saturation. Postganglionic sympathetic denervation of the tissue does not decrease binding to the subcellular fraction. Drugs known to act on the α-adrenoceptor are specific inhibitors of [3H]dihydroazapetine binding while those acting on other receptors are without effect. Scatchard plot analysis suggests that two specific binding components are present, one of which has a similar dissociation constant for [3H]dihydro-azapetine to that determined pharmacologically. [3H]Dihydroazapetine binding is lowest in the physiological pH range and tends to decrease with increasing temperature in the range of 25 to 60°. Calcium, magnesium, sodium and potassium inhibit binding of [3H]dihydroazapetine with the divalent ions being approximately 100 times more potent. Studies with group selective reagents indicate that a disulphide bridge, and sulphydryl and carbonyl groups, are at or near the binding site and are necessary for binding. The site is protein possibly with involvement of phospholipids. Specific binding of [3H]dihydroazapetine is inhibited by low concentrations of local anaesthetics suggesting that the binding site of the antagonist may be related to the ‘calcium mobilization’ site of the α-adrenoceptor.
Studies of lesions induced in the testis and epididymis of F-344 rats by inhaled methyl chloride

Abstract Experiments were carried out in rats to characterize the development of the testicular and epididymal lesions and any associated effects on reproductive hormones. Adult F-344 rats were exposed to 3500 ppm methyl chloride (MeCl) 6 hr/day for 5 days, not exposed for 3 days, and exposed agin for 4 days. The first consistent testicular lesion was a delay in spermiation which appeared on Day 9. Subsequently, germinal epithelial vacuolation and cellular exfoliation became widespread as exposure continued. All animals killed after 19 days also displayed bilateral epididymal granulomas in regions 5 or 6 of the cauda epididymis. The nature and distribution of inflammatory cells indicated that the primary neutrophilic response may be against the tubular epithelium and not extravasated sperm. After 5 days of exposure, circulating testosterone was below 6 ng/ml (control: 120 ± 31 ng/ml). Both MeCl exposed and control animals responded similarly to challenge with hCG and LHRH ethylamide, suggesting that Leydig cell and gonadotrope function was unaffected. It is proposed that MeCl acts centrally to lower circulating testosterone. Nonprotein sulfhydryls were depleted in liver, testis, and epididymis after MeCl exposure, but not in whole blood. This finding indicates that sulfhydryl depletion is not due to direct alkylation, but is enzymatically mediated. Sulfhydryl depletion did not correlate with lesion development. It was concluded that the initial testicular effects of MeCl are directed at either the late stage spermatids or the Sertoli cells with a resultant delay in spermiation.