cssi/SciSciGPT-SciSciNet huggingface dataset:
Dislocation pile-ups as sites for formation of electromigration-induced transgranular slit-like voids in al interconnects

Electromigration-induced voiding in metal interconnects in Si integrated circuits is a serious reliability concern. The microstructure of narrow interconnects subject to post-pattern anneal is expected to be bamboo-like in character. These structures are best described as chains of single crystals, with grain boundaries perpendicular to the interconnect axis. In these microstructures, two distinct types of void morphologies have been reported in Al-alloy interconnects: large, wedge shaped erosion voids (E-voids), and narrow slit-like voids (S-voids). A summarized below, electromigration experiments conducted on single-crystal Al interconnects have clearly shown that the transition of erosion voids to slit-like voids is very strongly dependent on the crystallography of the interconnect, and also that there is some inhomogeneously distributed feature which triggers S-void formation, even in single-crystal interconnects. In summary, the authors feel that the strong crystallographic dependence of the S-voids, the possible effects of the enormous mechanical stresses (in excess of 1 GPa in some cases) which can exist in such interconnects, and the stochastic nature of the development of slit-like features, have not been adequately captured in the existing models. In what follows, the authors present a model for a role that dislocation pile-ups may play in reducing the energy of transition ofmore » E-voids to S-voids, and for controlling the location of this transition.« less
Effects of Fusarium solani naphthazarin toxins on the cytology and ultrastructure of rough lemon seedlings

Two naphthazarin phytotoxins (dihydrofusarubin and isomarticin) produced byFusarium solani were used to determine their effects on the cytology of leaves of rough lemon (Citrus jambhiri Lush) seedlings maintained in a dilute solution of the toxins. Dihydrofusarubin alone or in combination with isomarticin (80:20, v/v) caused cell necrosis above the midveins and lateral veins, plasmolysis or collapse of spongy mesophyll cells, collapse of phloem, depletion of starch, swelling of chloroplasts and disruption of cellular organization. At the ultrastructural level, the toxins affected chloroplast membranes by causing swelling, breaks in outer membranes, granal stack disorganization and swelling of intergranal membranes. The interstromal lamellae appeared as vesicles and sometimes as peripheral reticulum, with an increase in plastoglobuli. The tonoplast was broken or vesiculated. The only membranes not affected by the toxins were those of the nucleus and the mitochondria. This study establishes that the initial toxin effects of these fungal phytotoxins are on organellar membranes, primarily those of the chloroplasts, plasmalemma and tonoplast.
Optical and thermal effects in laser chemical vapor deposition

In laser chemical vapor deposition (LCVD), a laser is used to drive a deposition reaction by locally heating the substrate. Although the reactant systems used may be similar to conventional CVD, the film growth characteristics may differ in several ways. The changes in the optical properties of the film/substrate during deposition must be considered as the amount of laser energy absorbed determines the surface temperature and therefore the deposition rate. Also affecting the deposition rate is the diffusion of reactants to the reaction zone. Because of the small area heated in LCVD, higher surface temperatures can be accessed before diffusion and convection limit the deposition rate. For favorable reactant systems, very rapid deposition rates (greater than 100 ..mu..m/sec) and scan speeds for line deposition (greater than 10 cm/sec) can be achieved. 24 references, 5 figures, 2 tables.
Single-particle tracking: models of directed transport

Single-particle tracking techniques make it possible to measure motion of individual particles on the cell surface. In these experiments, individual trajectories are observed, so the data analysis must take into account the randomness of individual random walks. Methods of data analysis are discussed for models combining diffusion and directed motion. In the uniform flow model, a tracer simultaneously diffuses and undergoes directed motion. In the conveyor belt model, a tracer binds and unbinds to a uniform conveyor belt moving with constant velocity. If a tracer is bound, it moves at the velocity of the conveyor belt; if it is unbound, it diffuses freely. Trajectories are analyzed using parameters that measure the extent and asymmetry of the trajectory. A method of assessing the usefulness of such parameters is presented, and pitfalls in data analysis are discussed. Joint probability distributions of pairs of extent and asymmetry parameters are obtained for a pure random walk. These distributions can be used to show that a trajectory is not likely to have resulted from a pure random walk.
Conceptual Design of NDT Field Inspection System

Efforts to effectively determine the life of a cannon barrel have now been extended to developing a conceptual design for a nondestructive testing system to evaluate the condition of gun barrels in the field. This paper describes the development of an autonomous vehicle capable of traveling the length of a large caliber cannon barrel to scan the interior surface for cracks and flaws that would indicate that the barrel needs to be decommissioned. This robotic vehicle carries a bore scope to provide visual inspection and an ultrasonic transducer (UT) with which to examine the barrel. The UT data collected is stored on a computer for both real-time analysis and statistical computational usages. The data and images collected from the bore scope are then used to monitor and predict fatigue related stress cracks in the barrel material. The system is designed to be portable and to be capable of being used in remote locations where these weapons are deployed. The non-destructive testing capabilities of this equipment will help to make the large caliber cannon barrels both safer and more reliable. The increased number of inspections possible with this portable field system will improve the crack detection process and thereby increase the safety of the weapons for the soldier/operators, as well as efficiently and effectively monitor the usable life associated with large caliber cannons.Copyright © 2008 by ASME
On powers and centers of chordal graphs

A graph is chordal if every cycle of length strictly greater than three has a chord. A necessary and sufficient condition is given for all powers of a chordal graph to be chordal. In addition, it is shown that for connected chordal graphs the center (the set of all vertices with minimum eccentricity) always induces a connected subgraph. A relationship between the radius and diameter of chordal graphs is also established.
Bounds for the spectrum of normal matrices

Abstract Let A be a normal matrix with eigenvalues λ1, λ2,…, λn, and let Г denote the smallest disc containing these eigenvalues. We give some inequalities relating the center and radius of Г to the entries in A. When applied to Hermitian matrices our results give lower bounds on the spread maxij(λi – λj) of A. When applied to positive definite Hermitian matrices they give lower bounds on the Kantorovich ratio maxij(λi – λj)/(λi + λj).
The Physical Properties of the Bethel Sandstone of South-Central Illinois: ABSTRACT

For the past 10 months the writer has been engaged in making a detailed study of the physical properties of the Bethel sandstone as they are revealed in cores from wells drilled in south-central Illinois. The investigation has been undertaken in cooperation with the Illinois State Geological Survey. The Bethel sandstone is found to be very uniform in all of its physical properties both vertically and laterally although some gradations exist. The study has revealed that most of the sand has come from older sediments. Most of it has undergone at least one earlier period of deposition under conditions in which the cement was silica and some has undergone at least three cycles of erosion. Some of the sand has been derived from redbeds and the grains are frosted. The original source of the sand was in part from dynamically metamorphosed rocks and in part from regionally or thermally metamorphosed rocks. A large part originally came from igneous rocks, probably granites since the associated feldspar is acidic. Heavy minerals are very rare but those found constitute about thirty species. A number of varieties of tourmaline and zircon are distinguished. Ten varieties of quartz are found which are readily distinguishable and it is proposed that more data can be derived concerning the origin and history of a given deposit by a detailed study of quartz and its varieties and inclusions, than from heavy-mineral studies and without the laborious procedure of making heavy-mineral concentrates. A detailed discussion of the inter-relations of the physical properties of the sand, together with an analysis of the effect of these upon the porosity and permeability of the Bethel, is given. This together with certain detailed information concerning the pores and pore pattern, the relationship of the silica and carbonate periods of cementation, and soluble minerals are discussed in the relationship they have upon securing End_Page 913------------------------------ greater primary and secondary recovery of oil. The information cementation yields concerning the periods of folding and oil accumulation is brought out. In conclusion, the physical properties of the Bethel sandstone are compared with other sands of the Chester series, and insofar as possible the detailed data from the Bethel is applied to the other sand zones. The paleogeography and source of sediments are likewise discussed. End_of_Article - Last_Page 914------------
Effects of strains on optical mode properties in crystals of the rocksalt and zinc-blende structures

A microscopic, lattice-dynamical theory is presented of the effects of strains on the frequencies of $\stackrel{\ensuremath{\rightarrow}}{\mathrm{k}}\ensuremath{\approx}0$ optical modes and transverse effective charges in polar crystals. The general results are applied to cubic crystals of the rocksalt and zinc-blende structures. The strain dependence of the transverse effective charge and the optical-frequency dielectric constant is incorporated into the theory together with the strain dependence of the atomic force constants associated with the short-range interatomic forces. A theory of the effects of strains on polariton dispersion curves in crystals of the rocksalt and zinc-blende structures is also presented. The predictions of the theory, calculated on the basis of simple models of crystals of the rocksalt and zinc-blende structures, are compared with existing experimental data.
ON THE SEISMIC DISPLACEMENT RESPONSE OF RIGID RETAINING WALLS

ABSTRACT A finite element model capable of taking into account nonlinear hysteretic soil behavior is presented to study earthquake induced retaining wall movement. The model also accounts for increase in lateral stresses and settlement associated with grain slip caused by cyclic loads. The predictive capability of the proposed method is verified by comparing responses given by the model with those computed by another existing finite element model and also with responses recorded at the Cambridge centrifuge facility. The study reveals that the wall displacement can be substantially affected, among other factors, by the increase in lateral stresses due to grain slip and wall-soil friction. Care should be taken when selecting a constant value of wall-soil friction angle for the entire duration of excitation since structural changes can occur in the soil adjacent to the wall.
Educational Goals of Automotive Mechanics Students Attending Postsecondary Vocational Institutes in Georgia.

The importance of vocational education has long been recognized in meeting society's need for trained workers. Since the early 1960s there has been a gradual shift in emphasis of federal vocational education priorities from specific programs (e.g., agriculture) to special populations, such as minorities, women, disadvantaged or handicapped individuals, and individuals with limited English‐speaking proficiency (Ohanneson, 1982). The Vocational Education Act Amendments of 1976 reinforced this emphasis by requiring that follow‐up information be collected, not just by the vocational discipline but by special population groups as well (U.S. 94th Congress, 1976). Subsequent vocational education legislation places emphasis on providing vocational education to all individuals who can benefit from such training (U.S. 98th Congress, 1984; U.S. 101st Congress, 1990).
Potato leafroll virus spread in differentially resistant potato cultivars under varying aphid densities

An action threshold of 3-10 green peach aphid,Myzus persicae (Sulzer), apterae per 100 lower leaves is recommended for use in Minnesota to prevent further spread of potato leafroll virus (PLRV) in potato,Solarium tuberosum L. This threshold was first developed and validated using the PLRV susceptible cultivar Russet Burbank. Here we report experiments to determine if higher aphid densities could be tolerated in PLRV resistant cultivars,i.e., Kennebec (moderately resistant) or Cascade (highly resistant), without an increase in PLRV infection. Insecticidal sprays were applied to plots when predetermined target aphid densities, based on number of apterae per 100 leaves, were reached: 3, 10, 30, and 100 (Russet Burbank); 10, 30, 100, and 300 (Kennebec); and 30, 100, 300, and 1000 (Cascade). The response variable was the average percentage of PLRV infected plants. Overall mean cumulative aphid-days and percent PLRV infection were 617 and 23.5% for Russet Burbank, 1,296 and 10.2% for Kennebec, and 4,816 and 9.5% for Cascade. For each cultivar, the highest target aphid density tolerated without an increase in PLRV spread was determined by comparing PLRV infection in plots sprayed on predetermined thresholds to PLRV infection in plots where aphids were rigorously controlled. This maximum density was 10 apterae per 100 leaves for Russet Burbank and 300 apterae per 100 leaves for Cascade. Results using Kennebec were ambiguous, but Kennebec was always more resistant to PLRV than Russet Burbank. Excised leaflet tests showed that the cultivars did not differ in resistance to green peach aphid. It appears that action thresholds based on green peach aphid apterae can be different depending upon the inherent PLRV-resistance of the cultivar.
Left Ventricular Hypertrophy in a Runner Things Are Not Always What They Seem

A 63-year-old male runner presented for outpatient cardiology evaluation of decreased exercise tolerance and increased left ventricular (LV) wall thickness noted on an echocardiogram obtained by his primary care provider. The patient had been an avid runner since a young age; however, over the previous months he had noted decreased exercise tolerance prompting evaluation by his primary physician. His medical history was only significant for hypertension that had been well controlled with a single medication. ECG revealed sinus bradycardia with markedly elevated voltage in the anterolateral precordial leads (Figure 1). Echocardiography with strain imaging demonstrated increased LV wall thickness measuring 1.8 cm at the basal septum and 1.7 cm at the basal inferolateral wall (Figure 2A). Ejection fraction was noted to be normal; however, longitudinal strain imaging was markedly abnormal throughout the septum, extending into adjacent regions of the anterior and inferior walls and normalizing in the lateral wall and apex (Figure 2B and 2C). Figure 1. ECG demonstrating sinus bradycardia with increased voltage throughout the anterolateral precordial leads. Figure 2. A , Two-dimensional …
A Stress Analysis Method for Bi-axially Loaded Fastener Hole in Composite Laminate of Finite Geometry

A stress analysis method has been developed for a bi-axially loaded fastener hole in a laminated plate of finite geometry. The method is based on a variational formulation involving complex variables. In this method, the equilibrium and compatibility equations are satisfied in the domain of the plate due to the employment of the complex stress potentials and all the boundary conditions are satisfied through a variational statement. Therefore, the requirement for finite width corrections in relatively large fastener hole cases is avoided. The method has been verified through comparison with finite element results.
Leptin in Anorexia and Cachexia Syndrome

Leptin is a product of the obese (OB) gene secreted by adipocytes in proportion to fat mass. It decreases food intake and increases energy expenditure by affecting the balance between orexigenic and anorexigenic hypothalamic pathways. Low leptin levels are responsible for the compensatory increase in appetite and body weight and decreased energy expenditure (EE) following caloric deprivation. The anorexia-cachexia syndrome is a complication of many chronic conditions including cancer, chronic obstructive pulmonary disease, congestive heart failure, chronic kidney disease, and aging, where the decrease in body weight and food intake is not followed by a compensatory increase in appetite or decreased EE. Crosstalk between leptin and inflammatory signaling known to be activated in these conditions may be responsible for this paradox. This manuscript will review the evidence and potential mechanisms mediating changes in the leptin pathway in the setting of anorexia and cachexia associated with chronic diseases.
A Novel Approach to Scavenging Anesthetic Gases in Rodent Surgery

Laboratory animal procedures using gas anesthetics may amass elevated waste gas concentrations in operating rooms if controls are not implemented for capturing and removing the vapors. Area sampling using an infrared analyzer indicated isoflurane concentrations likely to exceed occupational exposure guidelines. Our study showed environmental concentrations of oxygen as high as 40% and isoflurane concentrations >100 ppm when no controls or merely passive controls were utilized. These extraneous isoflurane emissions were determined to be originating from the pre-procedural induction process as well as the gas delivery nose cone. A novel waste gas collection cylinder was designed to enclose the gas delivery nose cone and animal head during the administration of anesthetic gases. The vented cylinder utilized a house vacuum to remove the waste anesthetic gases from the surgical field. A commercially available induction chamber designed to be actively and externally exhausted was used to lower concentrations du...
Protein Hydration during Generation of Coagulation Factor Xa in Aqueous Phase and on Phospholipid Membranes

Abstract The energetic contribution of protein solvation-desolvation reactions to generation of coagulation activated factor X (FXa) by the extrinsic pathway protease complex was determined using the technique of osmotic stress. The initial rate of FXa generation by limited proteolysis of human FX was measured in reaction mixtures with human tissue factor (TF) and factor VIIa (FVIIa) assembled either in aqueous phase or on phospholipid membranes. Osmotic stress was induced on the surface of reacting proteins with either polyethylene glycol, or dextran of 6000 and 500,000 molecular weight, respectively. These inert polymers are sterically excluded from the the solvation shells of proteins and thus increase the water activity in the excluded spaces. The volume of water transferred either to or from the excluded spaces during formation of reaction intermediates was calculated from the ratio of change in free energy of activation with change in osmotic pressure, ΔG*/Δ. For aqueous phase-assembled reactions, ΔG* values decreased with Δ at ratios of −2.36 ± 0.38 and −2.26 ± 0.26 kcal/mol/atm for polyethylene glycol and dextran, respectively. These values correspond to 5488 ± 883 and 5255 ± 604 mol of water transferred from the reacting protein surfaces per mol of FXa generated. At a physiologic osmotic pressure of 7 atm the work of transfer corresponded to 16 kcal/mol, approximately 70% of ΔG*. The observed osmotic effects were independent of the viscosity, temperature, and ionic strength of solutions. For reactions assembled on phospholipid membranes, ΔG* increased with Δ at a ratio of 0.35 ± 0.05 kcal/mol/atm, corresponding to 814 ± 116 mol of water tansferred from bulk solution to protein surfaces. At physiologic osmotic pressure the work of transfer is 2.45 kcal/mol, approximately 12% of ΔG*. Results indicate that for factor Xa generation in aqueous phase the work of desolvation is a significant component of the free energy of activation. Results also suggest that phospholipid membranes catalyze the reaction by reducing the desolvation component of the free energy of activation.
Dissecting paclitaxel-microtubule association: quantitative assessment of the 2'-OH group

Paclitaxel (PTX) is a microtubule-stabilizing agent that is widely used in cancer chemotherapy. This structurally complex natural product acts by binding to β-tubulin in assembled microtubules. The 2'-hydroxyl group in the flexible side chain of PTX is an absolute requirement for activity, but its precise role in the drug-receptor interaction has not been specifically investigated. The contribution of the 2'-OH group to the affinity and tubulin-assembly efficacy of PTX has been evaluated through quantitative analysis of PTX derivatives possessing side chain deletions: 2'-deoxy-PTX, N-debenzoyl-2'-deoxy-PTX, and baccatin III. The affinity of 2'-deoxy-PTX for stabilized microtubules was more than 100-fold lower than that of PTX and only ~3-fold greater than the microtubule affinity of baccatin III. No microtubule binding activity was detected for the analogue N-debenzoyl-2'-deoxy-PTX. The tubulin-assembly efficacy of each ligand was consistent with the microtubule binding affinity, as was the trend in cytotoxicities. Molecular dynamics simulations revealed that the 2'-OH group of PTX can form a persistent hydrogen bond with D26 within the microtubule binding site. The absence of this interaction between 2'-deoxy-PTX and the receptor can account for the difference in binding free energy. Computational analyses also provide a possible explanation for why N-debenzoyl-2'-deoxy-PTX is inactive, in spite of the fact that it is essentially a substituted baccatin III. We propose that the hydrogen bonding interaction between the 2'-OH group and D26 is the most important stabilizing interaction that PTX forms with tubulin in the region of the C-13 side chain. We further hypothesize that the substituents at the 3'-position function to orient the 2'-OH group for a productive hydrogen bonding interaction with the protein.
Herceptin : mechanisms of action and resistance

HER-2 is overexpressed in 20-25% of invasive breast cancers and is associated with an aggressive tumor phenotype and reduced survival rate. The HER-2 status of a tumor is the critical determinant of response to the HER-2-targeted antibody Herceptin. Thus, accurate assessment of HER-2 expression levels is essential for identifying breast cancer patients who will benefit from HER-2-targeted therapy. Herceptin combined with chemotherapy increases response rates, time to disease progression, and survival. However, the majority of cancers that initially respond to Herceptin begin to progress again within 1 year. This review describes mechanisms by which Herceptin inhibits cell growth in breast cancers that overexpress HER-2 and highlights possible mechanisms contributing to Herceptin resistance.
An electronic blood-count meter

A direct-reading blood-count meter is described which yields results independent of particle size and coloration, rate of sampling, and quantity sampled. Errors from zeroing, changing sensitivity, and changing illumination are eliminated by a grid-current ratio amplifier.
Neural estimation and embedology for time-series prediction

Time series prediction has widespread application, ranging from predicting the stock market to trying to predict future locations of scud missiles. The embedology theorem sets forth the procedures for state space manipulation and reconstruction for time series prediction. This includes embedding the time series into a higher dimensional space in order to form an attractor, a structure defined by the embedded vectors. In this paper, embedology is combined with neural technologies in an effort to create a more accurate prediction algorithm. The algorithms tested are embedology, neural networks, and Euclidean space nearest neighbors. Local linear training methods are compared to the use of the nearest neighbors as the training set for a neural network. The results of these experiments determine that the neural algorithms have the best prediction accuracies. The performance of the nearest neighbor trained neural network validates the applicability of the local linear training set.
Injected Versus Oral Cyclosporine for Human Neural Progenitor Grafting in Rats.

Background: Neural cell transplantation is a promising therapy for stroke, but rejection of human cells in animal models is an obstacle to furthering this research. Many antirejection strategies have been reported, but few comparison data are available. We asked if human neural cell grafts would have different survival or differentiation with injected or oral cyclosporine regimens. Methods: Rats received intracerebral grafts of human embryonic stem cell-derived neural progenitors, and 6 rats each were randomized to 4 cyclosporine regimens: 1) daily injections, 2) initial injections followed by oral drug in the drinking water, 3) oral drug only, or 4) no cyclosporine. Histology was performed 14 days after grafting for quantification of markers of human cells, neural cell types, and immune cells. Results: More rats in the injection (6/6) and injection+oral (5/6) groups had surviving graft cells than in the oral (1/6) and control (3/6) groups (p<0.05), with a trend toward a greater number of surviving graft cells as well. All rats with surviving graft cells also had these cells co-label for a neural progenitor marker, and a minority of graft cells colabeled for a cell division marker and a neuronal marker. Rats with areas of dead graft cell debris were seen in all of the groups. In these areas, cells that labeled for microglial markers also contained the human nuclear marker in their cytoplasm, suggestingphagocytosis of the graft cells. Conclusions: Human neural cell survival in rat brain tissue differed between cyclosporine regimens, but microglial phagocytosis of graft cells occurred in all the groups. Frequent injection of laboratory animals is undesirable, and a compromise strategy of peritransplant injections followed by drug in the drinking water showed good results in preventing graft cell rejection. Further research is needed to optimize the antirejection approach for this application.
"STOP regain": Are there negative effects of daily weighing?

Several recent studies suggest that daily weighing is important for long-term weight control, but concerns have been raised about possible adverse psychological effects. The "STOP Regain" clinical trial provides a unique opportunity to examine this issue both cross-sectionally and prospectively. Successful weight losers (N = 314) were randomly assigned to a control or to a face-to-face or Internet intervention designed to help them maintain their weight loss and were then followed for 18 months. The intervention groups reported increases in daily self-weighing, which were associated with successful weight loss maintenance. We found no evidence that increases in frequency of weighing or daily weighing per se had any adverse effects in this study population. Rather, increases in self-weighing were associated with increases in dietary restraint (p <.001), decreases in disinhibition (p <.003), and decreases in depressive symptoms (p <.002). Moreover, those who weighed daily at 18 months were less likely to report having ≥4 binge episodes per month (p =.03). Daily weighing appears to be an important aspect of weight loss maintenance and was not associated with adverse psychological effects.
Pressure dependence of Raman scattering in AgGaSe2

Abstract The pressure dependence of several one-phonon Raman modes in AgGaSe 2 has been measured by using a dye laser tuned near the bandgap exciton at low temperatures to enhance their Raman intensities. Most of the modes exhibit large nonlinear pressure dependence. Although none of the observed modes showed any softening at pressures approaching the structural phase transition value, the Γ 5L (W 3 ) mode at 139 cm −1 was found to broaden anomalously with pressure.
Influence of Methoprene and Dietary Protein on Male Anastrepha suspensa (Diptera: Tephritidae) Lipid and Protein Content

ABSTRACT Because both the application of a juvenile hormone analog, methoprene, and the addition of protein to the adult diet increased the sexual success of male Caribbean fruit fly, Anastrepha suspensa (Loew) (Diptera: Tephritidae), it was hypothesized that both might also impact male nutritional status. Total content of lipid and of protein in A. suspensa males were measured to discover if there was an effect of these treatments alone or in combination on the content of each of these subtstances. In the first 24 hours following adult emergence, 6 different treatments were applied (all possible combinations of methoprene in acetone solution or acetone alone, and protein-diet enrichment). Adult weight was determined for all treatments at 5, 10, 15, 20, 25, 30 and 35 d post-emergence. Dietary protein had a positive effect on the weight and total lipid and protein contents during the first 35 d of adult male life. There were minimal negative impacts from methoprene applications. Even though males were more...
Verifying critical values from DRIS norms in sweet cherry and hazelnut

Abstract Previously published DRIS norms for sweet cherry and hazelnut were used to calculate DRIS indices for N, K, P, Ca, Mg, Mn, Fe, Cu, B, and Zn on over a thousand leaf sample analyses for each crop. A nutritional imbalance index (NII) was obtained by adding the values of DRIS indices irrespective of sign. The sample with the lowest NII for each crop was assumed to have “ideal”; levels of elements and these “ideal”; levels were used to create an artificial data base to determine which critical values would be most consistent with DRIS evaluations. By maintaining all but one element concentration at “ideal”; levels and artificially varying another, the concentration of a given element that was associated with the onset of severe imbalances could be identified. In addition to providing ratio‐based diagnoses, DRIS norms provide a means of independently evaluating current sufficiency ranges for elements that DRIS diagnoses as relatively deficient or excessive.
Novel stress echocardiographic model incorporating the extent and severity of wall motion abnormality for risk stratification and prognosis.

The prognostic value of stress echocardiography to predict future cardiac events using the extent and severity of wall motion abnormalities is not well defined. The objective of this study was to develop and validate a prognostic model for interpretation of stress echocardiographic studies by using the extent and severity of wall motion abnormalities. We evaluated 1,500 patients (59 ± 13 years old; 51% men) who underwent stress echocardiography (34% on the treadmill exercise and 66% on dobutamine). Left ventricular regional wall motion was assessed by consensus of 2 experienced echocardiographers. Follow-up periods (mean 2.7 ± 1.0 years) for confirmed myocardial infarction (n = 31) and cardiac death (n = 44) were identified. Multivariate regression analysis identified 2 independent predictors of cardiac events: the number of left ventricular wall segments with new wall motion abnormalities (an index of the extent of ischemia) and the maximal magnitude of new wall motion abnormalities (an index of the severity of ischemia). The ischemic extent (chi-square 48.7, p
The conceptualization and representation of total performance effectiveness

Abstract Viewing performance as a distribution of outcomes or behaviors leads to methods of assessing performance that diverge sharply from conventional rating methods. The distributional perspective also suggests flaws in the conventional assumption that only the mean conveys useful information about performance. Distributional assessments can be scored on a new index of Total Performance Effectiveness, which is constructed to be sensitive to differences on all distributional parameters. Data are presented which strongly support the comprehensive parametric sensitivity of this new index, and which show that even a well-constructed conventional rating method is insensitive to any distributional parameters other than the mean.
Intra‐arterial infusion therapy with 5‐(3,3‐dimeth yl‐1‐triazeno) imidazole‐4‐carboxamide (NSC 45388) for malignant melanoma

Seventeen patients with advanced regional malignant melanoma were treated with intra-arterial 5-(3,3-dimethyl-1-triazeno) imidazole-4-carboxamide (DTIC) in an attempt to improve the response rate to this drug. There were 6 partial objective (greater than 50% reduction) responders and one complete remission for an overall response rate of 41%. The local control of melanoma by this modality of treatment was impressive, and toxicity was less than that which is usually seen with systemic chemotherapy with DTIC. Our studies suggest intra-arterial therapy is preferrable to systemic therapy for the isolated inoperable melanoma lesion.
A comparison of techniques for assessing dispersion patterns

A series of artificial populations with different types of spatial distribution is used to test the value of a number of published indices in identifying non-randomness. Among tests based on distance measurements, that of Hopkins is generally the most powerful, through there are reasons for preferring that of Pielou where the vegetation has not been completely mapped. Among tests involving quadrat measurements, the variance/mean ratio appears to be best. Where contiguous series of quadrats are available hierarchical analysis of variance is a more powerful test than Monte-Carlo pairing of quadrats, though the latter is a more flexible technique. The value of different methods for describing pattern, once non-randomness has been established, is also discussed.
Changes in the intensity fluctuations of a class of random electromagnetic beams on propagation

We discuss fourth-order correlation properties of wide-sense statistically stationary, quasi-monochromatic, electromagnetic beams, assuming that the fluctuations in the electric field at any point are governed by Gaussian statistics. In particular, we derive expressions for the covariance function and for the contrast (scintillation index) of the fluctuating intensity of an electromagnetic Gaussian Schell-model beam, propagating in free space. For such beams we also derive expressions relating to fluctuations in the power and discuss the effects of transmitter and receiver aperture averaging. We show that the fluctuations of the intensity and of the power of the beam can be controlled by suitable choice of the states of coherence and of polarization of the source.
TU‐B‐210A‐01: Quality Assurance Testing of Gamma Camera and SPECT Systems

Routine quality control,calibration and performance testing of gamma cameras are necessary in order to consistently acquire good quality images without artifacts. This lecture will briefly cover the basics of gamma cameraimage formation and performance characteristics. The lecture will primarily focus on quality assurance tests for gamma cameras, both routine quality control and annual physics surveys. Some of the performance tests proscribed by NEMA are difficult to perform in the field so the physicist needs to know which tests are critical and practical ways to perform them in the field. It is becoming increasingly common for providers of nuclear medicine imaging services to seek accreditation, either from the American College of Radiology (ACR) or the Intersocietal Commission for Accreditation of Nuclear Medicine Laboratories (ICANL). The ACR defines a set of performance tests for the annual physics survey and these will be discussed as well as the tests required for submission for accreditation. Common problems and image artifacts will be discussed as well as how to correct these problems. Calibration procedures such as center of rotation and uniformity calibration will be discussed. Learning Objectives: 1. Learn the basics of gamma camera and SPECT performance measurements and quality assurance test procedures. 2. Become familiar with the annual physics survey performance tests defined by the ACR accreditation program. 3. Be able to identify and correct common problems and image artifacts in gamma camera and SPECTimaging.
Building a Word-Form Lexicon in the Face of Variable Input: Influences of Pitch and Amplitude on Early Spoken Word Recognition

To build their first lexicon, infants must first be able to recognize words in the input. This task is made challenging by the inherent variability of speech. Potential sources of variability include changes in speaker identity, vocal emotion, amplitude, and pitch. English-speaking adults can recognize a word regardless of these changes, and mature word recognition is not impeded by changes in amplitude or pitch. In this set of studies, we independently manipulate amplitude and pitch to examine whether infants' lexical processing is similarly invulnerable to changes in surface form. We found that 7.5-month-old infants at the earliest stages of word recognition can recognize a word if it is presented in a different amplitude but not in a different pitch. By 9 months, infants are able to recognize words independent of changes in pitch and amplitude, thus appearing to appreciate the irrelevance of both properties in determining lexical identity. Results are interpreted with respect to why infants may treat p...
Spinal accessory neuropathy, droopy shoulder, and thoracic outlet syndrome

Droopy shoulder has been proposed as a cause of thoracic outlet syndrome. Two patients developed manifestations of neurovascular compression upon arm abduction, associated with unilateral droopy shoulder and trapezius muscle weakness caused by iatrogenic spinal accessory neuropathies following cervical lymph node biopsies. The first patient developed a cold, numb hand with complete axillary artery occlusion when his arm was abducted to 90 degrees. The second patient complained of paresthesias in digits 4 and 5 of the right hand, worsened by elevation of the arm, with nerve conduction findings of right lower trunk plexopathy (low ulnar and medial antebrachial cutaneous sensory nerve action potentials). Spinal accessory nerve grafting (in the first patient) coupled with shoulder strengthening physical exercises in both patients resulted in gradual improvement of symptoms in 2 years. These two cases demonstrate that unilateral droopy shoulder secondary to trapezius muscle weakness may cause compression of the thoracic outlet structures.
Factors influencing breast milk versus formula feeding at discharge for very low birth weight infants in California.

Objective To investigate incidence and factors influencing breast milk feeding at discharge for very low birth weight infants (VLBW) in a population-based cohort. Study design We used data from the California Perinatal Quality Care Collaborative to calculate incidence of breast milk feeding at hospital discharge for 6790 VLBW infants born in 2005–2006. Multivariable logistic regression was used to examine which sociodemographic and medical factors were associated with breast milk feeding. The impact of removing risk adjustment for race was examined. Results At initial hospital discharge, 61.1% of VLBW infants were fed breast milk or breast milk supplemented with formula. Breast milk feeding was more common with higher birth weight and gestational age. After risk adjustment, multiple birth was associated with higher breast milk feeding. Factors associated with exclusive formula feeding were Hispanic ethnicity, African American race, and no prenatal care. Hospital risk-adjusted rates of breast milk feeding varied widely (range 19.7% to 100%) and differed when race was removed from adjustment. Conclusions A substantial number of VLBW infants were not fed breast milk at discharge. Specific groups may benefit from targeted interventions to promote breast milk feeding. There may be benefit to reporting risk-adjusted rates both including and excluding race in adjustment when considering quality improvement initiatives.
Hypohidrotic ectodermal dysplasia: a unique approach to esthetic and prosthetic management.

A case of hypohidrotic ectodermal dysplasia in a 9-year-old boy is presented; the problem of restoring esthetic appearance as well as dental function is discussed.
TOWARD A GENERAL THEORY OF BIODIVERSITY1

E. O. Wilson (2000) writes that ‘‘Community ecology in particular is about to emerge as one of the most significant intellectual frontiers of the 21st century.’’ If Wilson is correct, and I suspect that he is, Hubbell’s book will be viewed as the first milestone. It is a big, ambitious, creative, important book. Hubbell has set out to formulate a general synthetic theory of biological diversity. Even though his theory may ultimately be found to be partially incorrect or fatally flawed, it is a major achievement. Hubbell borrows liberally from the neutralist theory of evolutionary genetics developed by Kimura, Crow, Ewens, and others, and from the equilibrium theory of island biogeography developed by MacArthur and Wilson, to develop an unabashedly neutral theory of evolutionary ecology. Like MacArthur and Wilson (1967), he assumes that all species are, if not exactly identical in all respects, at least equivalent, so that any small differences among them do not influence the processes that determine species diversity. In Hubbell’s theory, diversity is the outcome of stochastic processes of both ecology and evolution operating on both local and regional scales. Ecological processes operate at the scale of a local community. Competition for shared, limited resources within and between species regulates the number of individuals, but deaths and births are random with respect to species. The result is a ‘‘zero sum game’’ in which the relative abundance of species is the outcome of stochastic events. Differences in diversity between local communities are attributed to random colonization and extinction processes. The local communities within a region are envisaged as forming a ‘‘metacommunity’’ whose diversity is generated and maintained by speciation. Random dispersal of propagules among the communities of a metacommunity leads to a balanced number of species. When a species goes extinct in a local community (because the last individual has died) it is on average replaced by a species that has colonized from the metacommunity. Hubbell develops mathematical models that specify the quantitative relationships among the above variables, processes, and assumptions. The theoretical development is very similar to the neutralist theory of evolutionary genetics. Indeed, Hubbell’s central model is mathematically identical to the infinite allele model of Ewens (1972), with species in a metacommunity being treated as analogous to alleles in a population. I have heard some colleagues mutter that all Hub-
Applications of redox polymers in biosensors

Abstract Polymers containing covalently attached redox molecules can be highly effective electron transfer mediators for flavin adenine dinucleotide redox centers of many oxidases. Highly flexible siloxane and ethylene oxide polymers containing covalently attached ferrocene molecules are shown to be capable of mediating electron transfer between enzymes and an electrode. The construction and response of bienzyme cholesterol biosensor, acetylcholine and glucose biosensor are described and discussed. Our data showed that the flexibility, hydrophilicity of the polymer, the density of redox centers in the polymer matrices and the self-exchange reaction rate of the redox molecules control the efficiency of the electron transfer mediation.
On the current flow for benzene-1,4-dithiol between two Au contacts

The current flow for a benzene-1,4-dithiol molecule between two Au contacts is computed. For most configurations considered, the computed current is an order of magnitude larger than experiment, as found by other groups. When the benzene-1,4-dithiol is bonded to the top of an fcc cluster of Au atoms, the current flow is significantly reduced, bringing it into better agreement with experiment. This represents an alternative to the previously proposed two molecule mechanism, as explanation of the experimental results.
Self-esteem and academic achievement: a comparative study of adolescent students in England and the United States

Utilizing mixed methodology, this paper investigates the relationship between self-esteem and academic achievement for young adolescents within two Western cultural contexts: the United States and England. Quantitative and qualitative data from 86 North American and 86 British adolescents were utilized to examine the links between self-esteem and academic achievement from the beginning to the end of their academic year during their 11th–12th year of age. For both samples, quantitative results demonstrated that fall self-esteem was related to multiple indicators of later year academic achievement. While country differences emerge by the end of the year, math appears to have a consistent relationship with self-esteem in both country contexts. Qualitative analyses found some support for British students’ self-perceptions as more accurately reflecting their academic experience than the students from the United States.
Correlation of outcomes with c4D in patients with cardiac allograft dysfunction

mean time gap between OHT to stem cell transplantation was 7.2 1.1 months. The patient with TTR amyloidosis had liver transplantation 5 years after OHT. The mean follow up period for AL amyloidosis is 15.5 7 months. The Follow up for TTR was 7 years. None of these patients had recurrence of cardiac amyloidosis in their transplanted heart during endomyocardial biopsies. There has not been signs or symptoms indicative of extra cardiac organ involvement with amyloidosis. Conclusion: Combined heart and stem cell transplantation in AL amyloidosis and combined heart and liver transplantation in transthyretin amyloidosis are successful strategies in treating cardiac amyloidosis with excellent intermediate-term survival.