cssi/SciSciGPT-SciSciNet huggingface dataset:
Late Palaeozoic cyclothems – A review of their stratigraphy and sedimentology

Abstract The term “cyclothem” was coined by Wanless and Weller (1932) to characterize a repetitive stratigraphic motif in the Pennsylvanian succession of the Illinois Basin, central USA, and it subsequently became popular among geologists as a general term for similarly repetitive successions worldwide. Although use of the term has become somewhat indiscriminate in the interim, it is here considered best reserved for the distinctive stratal rhythms characteristic of the late Palaeozoic in the palaeotropical realm of Laurussia, recording repeated alternation of marine and nonmarine depositional conditions. Cyclothems comprise arrays of terrigenous clastic, organic, and chemical/biochemical lithologies that record accumulation mainly on slowly-subsiding platforms and ramps, under limited accommodation and limited sediment supply, often strongly seasonal tropical and subtropical climates, and forcing by repeated, large-magnitude excursions of sea level. A spectrum of variation is recognized, from carbonate-mudrock-dominated variants at one extreme to coarse clastic-dominated styles at the other. Cyclothems can be rationalized as depositional sequences which are thin (metres to a few tens of metres), condensed, incomplete in terms of systems tracts, and top-truncated. Given their demonstrated widespread extent, cyclothems have been attributed by many researchers to forcing by eustatic sea-level fluctuations, and a variety of evidence suggests they correlate to 100 kyr glacial cycles on Gondwana. By analogy with Quaternary 100 kyr glacial cycles, much of the time in a cycle was taken up by a protracted, complex drawdown of sea-level, during which valleys and channels were excavated and interfluves were pedogenically modified. Most of the depositional record of cyclothems probably formed in the relatively short interval following lowstand/glacial maximum when sea-level rose to its interglacial maximum. Analysis of cyclothemic successions can contribute to a fuller understanding of the magnitude of sea-level excursions and palaeoclimatic changes during the late Palaeozoic, and can help to pinpoint the timing of key events such as the main onset of the late Palaeozoic Ice Age.
Volume measurement and biophysical characterization of mounds in epithelial monolayers after intracellular bacterial infection.

Summary Mechanical forces are important in (patho)physiological processes, including how host epithelial cells interact with intracellular bacterial pathogens. As these pathogens disseminate within host epithelial monolayers, large mounds of infected cells are formed due to the forceful action of surrounding uninfected cells, limiting bacterial spread across the basal cell monolayer. Here, we present a protocol for mound volume measurement and biophysical characterization of mound formation. Modifications to this protocol may be necessary for studying different host cell types or pathogenic organisms. For complete details on the use and execution of this protocol, please refer to Bastounis et al. (2021) .
Dermal Lymphatic Invasion, Survival, and Time to Recurrence or Progression in Inflammatory Breast Cancer.

OBJECTIVES Dermal lymphatic invasion (DLI) with tumor emboli is a common pathologic characteristic of inflammatory breast cancer (IBC), although its presence is not required for diagnosis. We examined whether documented DLI on skin biopsy was associated with survival and time to recurrence or progression in IBC. MATERIALS AND METHODS A total of 340 women enrolled in the IBC Registry at Dana-Farber Cancer Institute between 1997 and 2019 were included in this study. Kaplan-Meier curves and multivariable Cox proportional hazards models were used to estimate hazard ratios and 95% confidence intervals for associations of DLI and overall survival, time to locoregional recurrence/progression, and distant metastasis by stage at presentation. RESULTS DLI was detected in 215 (63.2%) of IBC cases overall. At disease presentation, IBC with DLI had a higher prevalence of de novo metastases (37.7% vs. 26.4%), breast skin ulceration (6.1% vs. 2.4%), and lymphovascular invasion within the breast parenchyma (52.9% vs. 25.5%) and a lower prevalence of palpable breast mass (48.2% vs. 70.6%) than IBC without DLI. Over a median follow-up of 2.0 years, 147 deaths occurred. DLI was not associated with survival or recurrence in multivariable models (all P ≥0.10). For example, among women with stage III disease, hazard ratios (95% confidence intervals) for DLI presence was 1.29 (0.77-2.15) for overall survival, 1.29 (0.56-3.00) for locoregional recurrence, and 1.71 (0.97-3.02) for distant metastasis. CONCLUSION Although the extent of tumor emboli in dermal lymphatics may be associated with biological features of IBC, DLI was not an independent prognostic marker of clinical outcomes in this study.
Financial and Work-flow Benefits of Reducing Avoidable Hospitalizations of Nursing Home Residents.

1) Explain the financial benefit of potential revenue recapture (PRR) for non-billable days due to hospitalizations of nursing home (NH) residents using a six-year longitudinal analysis of 11 of 16 NHs participating in the Missouri Quality Initiative (MOQI); and 2) Discuss the work-flow benefits of early detection of changes in health status using qualitative data from all MOQI homes. A CMS funded demonstration project with full-time advanced practice registered nurses (APRN) and operations support team focused on reducing avoidable hospitalizations for long stay NH residents (2012–2020). Setting was a sample of 11 of 16 US NHs participating in the CMS project. The NHs ranged in size between 121 and 321 beds located in urban and rural areas in one midwestern geographic region. Financial and occupancy data were analyzed using descriptive methods. Data are readily available from most NH financial systems and include information about short and long stay residents to calculate non-billable days due to hospitalizations. Average hospital transfer rates per 1000 resident days were used. Qualitative data collected in MOQI informed the work-flow benefits analysis. There was over $2.6 million in actual revenue recapture due to hospitalization of long stay residents in the 11 participating NHs during five years, 2015–2019, with 2014 as baseline; savings to payers was more than $31 million during those same years. The PRR for both short and long stay residents combined totaled $32.5 million for six years (2014–2019); for each NH this ranged from $590,000 to over $5 million. On average, an additional $500,000 of revenue each year per 200 beds could have been recaptured by further reducing hospitalizations. Workflow improved for nurses and nursing assistants using INTERACT and focusing on early detection of health changes. Reducing avoidable hospitalizations reduces costs to payers and increases revenue by substantially recapturing revenue lost each day of hospitalization. Focusing nursing staff on early illness recognition and management of condition changes within NHs has benefits for residents as the stress of hospital transfer and resulting functional decline is avoided. Nurses and nursing assistants benefit from workflow improvements by focusing on early illness detection, managing most condition changes within NHs. NHs benefit financially from increased revenue by reducing empty bed days.
Importance and prospects of bioinspired and biomimetic materials for drug delivery

Abstract This chapter summarizes the discoveries and inventions in the field of bioinspired and biomimetic materials over the last 30 years and sheds light on important areas with therapeutic application. Materials such as biopolymers, bio-macromolecules, silica, biomimetic nanonetworks as well as diverse cell-inspired nanoinventions have been discussed to elucidate their feasibility in drug-delivery mechanism.
Behavioural patterns among female African savannah elephants: the role of age, lactational status, and sex of the nursing calf

For social mammals, phenotypic factors, such as age and reproductive state, and environmental factors, such as competition and requirements for offspring, shape individual resource needs and cause animals to display behavioural patterns most useful in resource acquisition. Female mammals trade off investment in growth and survival against complex and resource-intensive reproductive challenges; thus, they alter behaviours according to changing priorities. To maximize net gain females increase resource intake or limit its expenditure. Behaviours that involve resource acquisition, such as foraging, are potentially rewarding, yet lead to competition, especially in group-living species; whereas behaviours that do not provide resources, such as resting or grooming, encourage sharing and buffer competition. In cooperative species with linear dominance hierarchies such as female African elephants ( Loxodonta africana africana), rank is often determined by age and size, which are highly correlated. When compared with younger, competitively disadvantaged individuals, higher ranked animals attain greater access to resources, but other phenotypic and environmental factors may influence their needs. Hence, we examined how lactational status and sex of the nursing offspring influenced time spent on resource acquisition, and we assessed how these factors affect rates of aggression related to age. We conducted the study at Addo Elephant National Park in South Africa from June to December 2010, using 20 min focal animal sampling on reproductively mature females ( N = 109 ). Adult females ( N = 64 ) exhibited aggression more frequently and socialized in a non-aggressive manner less frequently than subadult females ( N = 45 ). Lactating females ( N = 75 ) spent more time foraging, displayed aggression more frequently, socialized in a non-aggressive manner less frequently, and exhibited chemosensory behaviours less frequently than non-lactating conspecifics ( N = 34 ). Mothers of female calves ( N = 39 ) spent more time foraging than mothers of male calves ( N = 36 ). The latter spent more time nursing and resting. We show how behavioural patterns, permitted or limited by age (correlated with size and rank) and reproductive condition, pertain to resource needs in female elephants, in contexts not directly related to survival or starvation avoidance. We discuss our findings in the context of female social relationships, for a long-lived, cooperative species.
Chapter 7 Simulation experiments

Publisher Summary This chapter focuses on digital-computer modeling and on the analysis of stochastic systems to estimate performance measures. Both dynamic-system simulation and Monte Carlo simulation of models having no time component are considered in the chapter. Simulation is a method of modeling and analyzing stochastic systems using digital computers. A simulation model is an expression of the logical relationships that cause the system to change from one state to another. Given a simulation model,five steps are required to perform a simulation experiment: (1) select a source of randomness; (2) obtain basic observations from the source; (3) transform the basic observations to input observations having known distributions; (4) transform the input observations, via the model, to output observations; and (5) calculate statistics from the output observations to estimate the performance measures. The chapter discusses the issues that an analyst faces in each step of a simulation experiment. Output analysis is concerned with estimating the sampling properties of the point estimator. The prototype problem considers estimating the standard error of the sample mean of stationary autocorrelated data, an estimate of the population mean. Variations include nonstationary data and/or other properties, such as variance, higher-order moments and cross moments, quantiles, and percentiles. The use of the estimate of standard error in a variety of analysis procedures, such as for confidence intervals and for ranking and selection, also falls within the topic of output analysis.
Poly[4,4'-imino-dipyridinium [tetra-μ(3)-oxido-tetra-oxido-di-μ(4)-phosphato-κO:O':O'':O'''-tetra-vanadium(V)]].

In the title salt, {(C10H11N3)[V4O8(PO4)2]}n, cubane-like [V4O8]4+ clusters are connected by phosphate anions into anionic [V4P2O16]n2n− layers. These aggregate into the three-dimensional structure via N—H⋯O hydrogen-bonding mechanisms imparted by 4,4′-imino­dipyridinium dications situated between the layers.
The cognitive and neural basis of autism: A disorder of complex information processing and dysfunction of neocortical systems

Summary The findings of the neuropsychologic studies provide evidence of the selective involvement of higher order cognitive and neurologic abilities, suggesting that autism is a disorder of complex information processing. The saccadic eye movement studies provide evidence of a comparable selective pattern of dysfunction in the higher order circuitry of the brain, suggesting that the cognitive and behavioral abnormalities in autism are the result of the failure of the more advanced levels of neural systems development to evolve in autism. A great deal more research is needed to better understand the cognitive components of higher order cognitive abilities and their relationship to behavior in real life, the neural systems and neural connectivity that subserve them, and the course of development of these cognitive abilities and circuitry in autism and in normal individuals. Further understanding of these issues and of the genetic regulation of these brain developmental events will contribute significantly to the development of neurobiologically based interventions for autism and to the broader understanding of these issues relevant to many disorders of the central nervous system.
Modifier theory and meiotic drive

Abstract The evolutionary fate of rare modifiers of recessive lethal segregation distorters has been studied. Suppressors or partial suppressors will always increase in frequency. Enhancers will increase in frequency if linkage is sufficiently tight and be lost if linkage is sufficiently loose.
Intraband spectroscopy and photophysics in GaSe nanoparticles

The spectroscopic and dynamical characteristics of electron and hole intraband transitions in small $(2.7\phantom{\rule{0.3em}{0ex}}\mathrm{nm})$, mid-sized $(4.9\phantom{\rule{0.3em}{0ex}}\mathrm{nm})$, and large $(12\phantom{\rule{0.3em}{0ex}}\mathrm{nm})$ $\mathrm{GaSe}$ nanoparticles have been studied using polarized femtosecond transient absorption spectroscopy. Assignments of the observed absorptions are made in terms of the known band structure and an effective mass model in which the electron and hole states are described by particle-in-a-cylinder states. The energies and relative intensities of the optical transitions are calculated. Assignments of the dynamical aspects of the spectra are facilitated by comparison with time-resolved polarized fluorescence results. The results on the large particles indicate that the transient absorption spectrum is dominated by a size-independent, $z$-polarized hole intraband transition having an absorption maximum at about $600--650\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$. In addition, there is a smaller contribution from a broad $x,y$-polarized transition. The small particle spectra exhibit the same $z$-polarized hole transition and a much more intense $x,y$-polarized transition. The $x,y$-polarized absorption is assigned to an electron charge transfer transition from the conduction band to particle surface (edge) states. The intensity of this transition depends on the particle size and the momentum state ($\ensuremath{\Gamma}$ or $M$) of the electron. $\ensuremath{\Gamma}$ to $M$ electron momentum relaxation is responsible for the fast decay of the $x,y$-polarized electron transition in the small particles. This fast decay is not present in the large particles because the relative energetics of the $M$ to $\ensuremath{\Gamma}$ states are size dependent and are in reverse order, compared to the small particles. Relative intensities of the $x,y$-polarized electron transition may be semiquantitatively understood in terms of overlap considerations calculated from a simple two-dimensional, particle in a nonrigid box model.
Locating the rate-determining step(s) for three-step hydrolase-catalyzed reactions with DYNAFIT.

Abstract Hydrolytic reactions of oligopeptide 4-nitroanilides catalyzed by human-α-thrombin, human activated protein C and human factor Xa were studied at pH 8.0–8.4 and 25.0 ± 0.1 °C by the progress curve method and individual rate constants were calculated mostly within 10% internal error using DYNAFITV. A systematic strategy has been developed for fitting a three-step consecutive mechanism to eighteen hundred to six thousand time-course data points polled from two to four independent kinetic experiments. Enzyme and substrate concentrations were also calculated. Individual rate constants well reproduce published values obtained under comparable conditions and the Michaelis–Menten kinetic parameters calculated from these elementary rate constants are also within reasonable limits of published values. For comparison, the integrated Michaelis–Menten equation was also fitted to data from twelve sets. Both the k cat and k cat / K m values are within 15% agreement with those calculated using the elementary rate constants obtained with DYNAFITV. Rate constants for the second and third consecutive steps are within 3–4 fold indicating that both determine the overall rate. The Factor Xa-catalyzed hydrolysis of N -α-Z- d -Arg-Gly-Arg-pNA · 2HCl at pH 8.4 in a series of buffers containing increasing fractions of deuterium at 25.0 ± 0.1 °C shows a very strong dependence of k 3 and a moderate dependence of k 2 on D content in the buffer: the fractionation factors are: 0.49 ± 0.03 for K 1, 0.70 ± 0.05 for k 2 , and (0.32 ± 0.03) 2 for k 3.
Sensitivity Analysis of Quality Assurance Using the Spatial Regression Approach—A Case Study of the Maximum/Minimum Air Temperature

Abstract Both the spatial regression test (SRT) and inverse distance weighting (IDW) methods have been applied to provide estimates for the maximum air temperature (Tmax) and the minimum air temperature (Tmin) in the Applied Climate Information System (ACIS). This is critical to the processes of estimating missing data and identifying suspect data and is undertaken here to ensure quality data in ACIS. The SRT method was previously found to be superior to the IDW method; however, the sensitivity of the performance of both methods to input parameters has not been evaluated. A set of analyses is presented for both methods whereby the sensitivity to the radius of inclusion, the regression time window, the regression time offset, and the number of stations used to make the estimates are examined. Comparisons were also conducted between the SRT and the IDW methods. The performance of the SRT method stabilized when 10 or more stations were applied in the estimates. The optimal number of stations for the IDW meth...
Preimplantation embryology The molecular genetics of the zona pellucida: mouse mutations and infertility

The zona pellucida is an extracellular matrix surrounding growing oocytes, ovulated eggs and the preimplantation embryo. After mediating the relatively species-specific events of fertilization, the zona pellucida provides a post-fertilization block to polyspermy and protects the growing embryo as it passes down the oviduct. The genes that encode the three zona pellucida proteins (ZP1, ZP2, ZP3) have been characterized in mouse and human. The ability to genetically manipulate the zona pellucida genes in mouse models has enhanced our knowledge of zona pellucida structure and function in vivo and may translate into a better understanding of human fertility.
Slavery to freedom in sub‐Saharan Africa: Expectations and reality

(2000). Slavery to freedom in sub‐Saharan Africa: Expectations and reality. Slavery & Abolition: Vol. 21, After Slavery: Emancipation and its Discontents, pp. 237-264.
Visual communication technologies for computer graphics

Methods of displaying computer-generated graphic images are examined. Several alternative technologies are evaluated. Principles of operation are given for each of these advanced technologies. These color display technologies include screen cameras, film recorders, LCD projection devices, and RGB projectors. A brief survey of commercially available devices is presented. >
Automated visual inspection: 1981 to 1987

Abstract This bibliography lists journal publications, conference papers, research technical reports, and articles from trade journals on automated visual inspection for industry which were published during the years from 1981 to 1987. More than 600 references are included. References are organized into 13 categories according to subject matter. The categories are (1) books, (2) conferences and workshops, (3) general discussions and surveys, (4) inspection of printed circuit patterns, (5) inspection of solder joints, (6) inspection of microcircuit photomasks, (7) inspection of integrated circuits and hybrids, (8) inspection of other electrical and electronics components, (9) surface inspection, (10) X-ray inspection, (11) other inspection applications, (12) system components, and (13) inspection algorithms. References listed in each category are arranged in chronological order. The purpose is primarily to provide a complete bibliography for those interested in automated visual inspection. Some general observations have been made for the above areas of activity summarizing the advances that have taken place and the problems that remain to be solved.
Tissue iron distribution and urinary mineral excretion vary depending on the form of iron (FeSO4 or NaFeEDTA) and the route of administration (oral or subcutaneous) in rats given high doses of iron.

Sodium iron ethylenediaminetetraacetate (NaFeEDTA) has considerable promise as an iron fortificant in food. However, effects of administering high levels of NaFeEDTA on tissue iron distribution and mineral excretion are not well understood. The objectives of this study were to assess nonheme iron distribution in the body and urinary excretion of Ca, Mg, Cu, Fe, and Zn after daily administration of high levels of iron to rats over 21 days. Iron was either given orally with food or injected subcutaneously, as either FeSO4 or NaFeEDTA. Selected tissues were collected for nonheme iron analysis. Estimated total body nonheme iron levels were similar in rats fed NaFeEDTA or FeSO4, but the tissue distribution was different: it was 53% lower in the liver and 86% higher in the kidneys among rats fed NaFeEDTA than among those fed FeSO4. In contrast, body nonheme iron was 3.2-fold higher in rats injected with FeSO4 than in rats injected with NaFeEDTA. Administering NaFeEDTA orally elevated urinary Cu, Fe, and Zn excr...
Randomized comparison of rapid ambulation using radial, 4 French femoral access, or femoral access with AngioSeal closure.

Radial access and closure devices are associated with improved quality of life (QOL) after cardiac catheterization. Whether this is related to the access site or time to ambulation is unknown. Seventy-five patients undergoing cardiac catheterization were randomized to femoral 6 Fr with AngioSeal closure (F+C), femoral 4 Fr without closure, and radial (R) access. All patients were ambulated at 1 hr. QOL was measured utilizing visual analogue scales and Short Form-36 at baseline, 1 day, and 1 week. Time to ambulation and discharge were equivalent, as was postprocedure QOL. However, angiographic quality was lower in the 4 Fr group (P < 0.0001) and catheterization costs were higher in the F+C group (P < 0.0001). Ambulation 1 hr after catheterization can be accomplished utilizing radial, femoral 6 Fr with closure device, or femoral 4 Fr access with equivalent outcomes and QOL. However, this is achieved at a higher cost with a closure device, or lesser angiographic quality with 4 Fr catheters. Catheter Cardiovasc Interv 2004;62:143–149. © 2004 Wiley-Liss, Inc.
Global mapping of nucleic acid conformational space: dinucleoside monophosphate conformations and transition pathways among conformational classes

A global conformational space of 6253 dinucleoside monophosphate (DMP) units consisting of RNA and DNA (free and protein/drug-bound) was ‘mapped’ using high resolution crystal structures cataloged in the Nucleic Acid Database (NDB). The torsion angles of each DMP were clustered in a reduced three-dimensional space using a classical multi-dimensional scaling method. The mapping of the conformational space reveals nine primary clusters which distinguish among the common A-, B- and Z-forms and their various substates, plus five secondary clusters for kinked or bent structures. Conformational relationships and possible transitional pathways among the substates are also examined using the conformational states of DNA and RNA bound with proteins or drugs as potential pathway intermediates.
Undular hydraulic jumps and the formation of backlash ripples on beaches

Field observations are made of the formation of backwash ripples on the beach face, formed by undular hydraulic jumps generated by backwash down the beach face colliding with wave bores. Measured ripple wavelengths range from set averages of 48 to 70 cm. Within a particular set of ripples the spacing tends to decrease in the offshore direction. These observations are compared with laboratory experiments where undular jumps are generated in a flume, and with a computer simulation model which calculates both the flow within an undular hydraulic jump and the resulting sediment transport which gives rise to the backwash ripples. The computer model involves a numerical solution of the Bousssinesq equations which govern the fluid flow, and sediment transport equations which relate the sand transport rate to the local mean flow velocity. The model permits a study of the detailed time-history of the undular jump development and the formation of the backwash ripples and shows good agreement with the field observations of backwash ripples, predicting an offshore decrease in their spacings. The laboratory experiments showed a similar result so long as the Froude number of the supercritical flow before the jump occurs is small (c. 1–4). Small differences between the computer model and experiments arose principally from the neglect of internal friction and surface tension in the model.
The relationship between human resource development and corporate creativity in Japan

This article reports the results of a two-year study of the development and expression of creativity in Japanese companies and describes the relationship between human resource development (HRD) and corporate creativity. The distinction between individual and corporate creativity is discussed, and a definition of corporate creativity is proposed. The results of this study indicate that HRD policy, and in particular education and training, can influence corporate creativity through the promotion of information movement within the company and the selective acquisition of diverse stimuli. Implications for HRD policy and practice are described.
A Weekly Group Meeting for Children on a Pediatric Ward: Therapeutic and Practical Functions

The multiple sources of psychological stress to the hospitalized child are reviewed with references to the literature. The Hahnemann Pediatric Ward and patient population are described as are the f...
The Craft of Emotion in Isabel Allende's Paula

Isabel Allende's narrative, from her first novel The House of the Spirits (1982) through the most recent works, has often been branded as "sentimental..." This article is available in Studies in 20th Century Literature: http://newprairiepress.org/sttcl/vol27/iss2/2 The Craft of Emotion in Isabel Allende's Paula
Training for flexible sigmoidoscopy

Three hundred twenty-six participants of five 1-day continuing medical education courses on flexible sigmoidoscopy were surveyed to determine their use of lower intestinal endoscopes and to identify how well the education trained them to use the flexible sigmoidoscope. The number of participants using a flexible sigmoidoscope and/or colonoscope increased after the course. About one half of the respondents went from no use of the flexible sigmoidoscope to using it. About one fifth of the respondents were not using a flexible sigmoidoscope after the course for various reasons. Most respondents used more than one instrument after the course, with the combination of the 60-cm flexible sigmoidoscope and the rigid sigmoidoscope being most popular. The overwhelming majority found the flexible sigmoidoscope to be either very easy to use or reasonably easy to use. Only one complication was reported. Most of the respondents had attended only this 1-day course, but one third had taken either other courses or had been supervised for several procedures.
Peptides of human immunodeficiency virus (HIV) evoke rat colonic electrolyte secretion inhibitable by the somatostatin analog octreotide.

Abstract An integral transmembrane glycoprotein of the Human Immunodeficiency Virus (HIV) is gp 41. Five peptides (P1, P2, P3, P4, and P5) containing a conserved region of the gp 41 molecule have been synthesized. We tested P3, P4 and P5 for their effects on short-circuit current (Isc) across rat colonic mucosa. All three peptides increased the Isc; P5 was the most potent agonist. Serosal pretreatment of tissues with the chloride transport inhibitor, bumetanide (0.1 mM) or chloride replacement with gluconate, inhibited the response, suggesting that the increase in Isc was due to stimulation of active chloride secretion. The synthetic somatostatin analog octreotide (0.1 mM) also inhibited (P
[11C]Tropanyl Benzilate-Binding to Muscarinic Cholinergic Receptors: Methodology and Kinetic Modeling Alternatives

Quantitative estimation of cerebral muscarinic receptors was investigated with the use of the antagonist [11C]tropanyl benzilate ([11C]TRB) and positron emission tomography (PET). Kinetic modeling alternatives were examined with the goal of identifying an analysis method providing stable receptor measures, yet avoiding biases from inappropriate reductions in model complexity. Dynamic PET scans were performed on six young normal volunteers. Several modeling approaches yielding relative receptor density measures were evaluated: (a) a single “late” scan using relative tracer concentration values; (b) a slope estimate from graphic analysis (Patlak plot); (c) a two-compartment, two-parameter model (transport and total ligand distribution volume); (d) a three-compartment, two-parameter model using the free + nonspecific distribution volume, DV‘, fixed to the cerebellar value; (e) an early scan for transport, a fixed value for DV’, and a single late scan for the binding rate constant; and (f) a three-compartment...
Meal patterns and foraging in melanocortin receptor knockout mice.

Abstract We report the meal patterns of mice with the deletion of either the melanocortin type 3 or 4 receptors (MC3RKO or MC4RKO) compared with that of the wild type (WT) under conditions of varying foraging costs. Mice lived in two-lever operant chambers; the completion of a designated number of responses (termed procurement fixed ratio or PFR) on the “foraging” lever activated the other lever. On this second lever, the completion of a designated number of responses (termed consumatory fixed ratio or CFR) caused the delivery of a 20-mg food pellet. Animals could complete as many CFRs as they wished to constitute a meal, but whenever 10 min elapsed without pressing on this second lever, the meal was terminated and pressing on the “foraging” lever was again required to initiate a new meal. At lower PFRs, mice of all three genotypes took 5–7 well-defined meals per day of ∼35 pellets/meal. At the highest PFR, mice of all three groups took about half this number of meals, with some increase in meal size, and total intake was slightly reduced. MC4RKO mice were obese compared with WT or MC3RKO but failed to eat more food in the operant chambers and, as a consequence, lost weight, regardless of PFR. Thus, changes in meal-taking strategies as a function of imposed foraging cost are not critically dependent on either MC3 or MC4 receptors, but these conditions did not allow us to study meal patterns in MC4RKO mice that are hyperphagic.
Holey Coronas A Solution of the Grünbaum-Shephard Conjecture on Convex Isohedral Tilings

In an article published recently in the section of Unsolved Problems of this MONTHLY, Branko Griunbaum [1] proposes the following conjecture: If S9 is an isohedral tiling of the Euclidean d-dimensional space by copies of a convex tile, then the corona of each tile is topological ball. The same conjecture is discussed as an open question in the article of Geoffrey C. Shephard [3], in which the author proves its stronger version for d = 2. We shall therefore refer to it as the Griinbaum-Shephard Conjecture. A tiling S9' is a collection of closed topological balls (disks, for d = 2) with mutually disjoint interiors (the tiles of S) such that the union of all tiles is the whole space. If all tiles are congruent, then S9 is monohedral, and their common shape is said to be the prototile of Y A tiling is isohedral provided its symmetry group acts transitively on the tiles; it is convex provided each of its tiles is convex. A lattice (of vectors) in R d is the collection of linear combinations with integer coefficients of a basis for R d. A typical example of a lattice is the collection of all vectors with integer coordinates, called the integer lattice (every lattice is affinely equivalent to the integer lattice). A monohedral tiling consisting of translates of the prototile by the vectors of a lattice is called a lattice tiling. Obviously, every lattice tiling is isohedral, while the converse is not true even in the plane. The corona of a tile T of S is the union of all tiles that meet T, including T itself. For example, in the usual (face-to-face) integer-lattice tiling of d-dimensional space by unit cubes, the corona of each tile is a cube of edge-length 3. Obviously, in an isohedral tiling, the coronas of any two tiles are congruent. See Griinbaum and Shephard [2] for a nearly encyclopedic survey of the theory of plane tilings; also see Schulte [4] and Schattschneider and Senechal [5], which deal with tilings in higher dimensional spaces. Grunbaum [1] observes that a confirmation of his conjecture for d = 2 (even without the assumption of convexity) can be established by inspection, since all types of isohedral tilings of the plane are known [2, Chapter 6]. He also conjectures that in the plane even more is true, namely that in every monohedral tiling of the plane the corona of every tile is simple (meaning simply-connected, hence homeomorphic to a disk). Shephard [3] found a non-convex counterexample, but also proved that in convex monohedral plane tilings every corona is simple [3, p. 358].
Lp-norms of periodizations over integer lattices

Abstract We show the boundedness of the mixed L p , p ′ ( [ 0 , 1 ] d × SO ( d ) ) norm of periodizations of a function f from L p ( R d ) ∩ L q ( R d ) where 1 ⩽ p ⩽ 2 and 1 ⩽ q q ( p ) and d ⩾ 5 .
Enzyme-Based Fiber Optic Sensors

Fiber optic chemical sensors capable of detecting glucose and penicillin were developed. Each consists of a polymer membrane that is covalently attached to the tip of a glass optical fiber. The membrane contains the enzyme and a pH-sensitive fluorescent dye (fluorescein). A signal is produced when the enzyme catalyzes the conversion of the analyte (glucose or penicillin) into a product (gluconic or penicilloic acid, respectively) that lowers the microenvironmental pH of the membrane and, consequently, lowers the fluorescence intensity of the dye. Each sensor is capable of responding to analyte concentrations in the range of ~0.1 to 100 mM. The penicillin optrode response time is 40 to 60 s while that for glucose is ~5 to 12 min.
Preparation of Native Oxide and Carbon-Minimized Ge Surface by NH4OH -Based Cleaning for High-k ∕ Ge MOS Gate Stacks

The native oxide and carbon-contaminant-minimized Ge surface with ammonium hydroxide (NH 4 0H)-based cleaning for high-k/Ge metal-oxide-semiconductor (MOS) gate stack application is reported. Furthermore, the carbon-free interfacial Ge-oxide layer preparation on the cleaned Ge surfaces was also studied. The thickness of GeO 2 on Ge surface before, during, and after different cleaning processes was evaluated by the spectroscopic ellipsometry measurements. The HF rinsing step in the cyclic HF/deionized water cleaning was not effective for a removal of native GeO 2 because it cannot form the soluble species by a chemical reaction in the low pH HF solution. A cyclic NH 4 OH-based cleaning results in a minimum residual GeO 2 at 3 and 8 A on Ge(111) and (100), respectively. The fast regrowth of GeO 2 on cleaned Ge surfaces under air exposure was observed, regardless of the cleaning methods. However, Auger electron spectroscopy spectra showed less amount of carbon on Ge surfaces with NH 4 OH-based cleaning than HF-based cleaning. The small amount of residual carbon after NH 4 OH-based wet cleaning was completely removed by O 2 plasma for a very thin ( ∼10 A) surface oxidation in the remote plasma-enhanced chemical vapor deposition chamber.
Relationship of hemodialysis access to finger gangrene in patients with end-stage renal disease.

Abstract Objective: We report a comprehensive review of our patients on hemodialysis with end-stage renal disease (ESRD) with finger gangrene to determine etiology, natural history, and prognosis of this condition. Methods: Patients with ESRD with finger gangrene were identified from our computerized vascular registry. Presence of an ipsilateral arteriovenous fistula was determined, and patients were compared with a group of patients with ESRD without finger gangrene. Management consisted of arteriography, selective arteriovenous fistula management, and finger amputation. A multivariate analysis to determine risk factors associated with finger gangrene was performed. Repeat finger amputation and survival rates were determined with life-table analysis. Results: Twenty-three patients (mean age at start of dialysis, 53 years) with finger gangrene were identified, with 48% (n = 11) having a functional ipsilateral arteriovenous fistula. Arteriography was consistent with diffuse atherosclerosis involving the radial, ulnar, palmar, and digital arteries precluding attempts at distal arterial bypass. Repeat finger amputations were necessitated in 52% of patients (n = 12), and bilateral finger gangrene developed in 61% of patients (n = 14). Starting dialysis at age less than 55 years ( P = .0004), diabetes ( P = .001), coronary artery disease ( P = .0212), and lower extremity arterial occlusive disease ( P Conclusion: The young diabetic patient with diffuse vascular disease and ESRD is at high risk for the development of finger gangrene on chronic hemodialysis. Finger gangrene is the result of distal atherosclerosis and is not primarily related to dialysis access. (J Vasc Surg 2002;36:245-9.)
Mach wave emission from a high-temperature supersonic jet

The paper considers the compressible Rayleigh equation as a model for the Mach wave emission mechanism associated with high temperature supersonic jets. Solutions to the compressible Rayleigh equation reveal the existence of several families of supersonically convecting instability waves. These waves directly radiate noise to the jet far field. The predicted noise characteristics are compared to previously acquired experimental data for an axisymmetric Mach 2 fully pressure balanced jet operating over a range of jet operating total temperatures from ambient to 1370 K. The results of this comparison show that the first order supersonic instability wave and the Kelvin-Helmholtz first, second, and third order modes have directional radiation characteristics that are in agreement with observed data. The assumption of equal initial amplitudes for all of the waves leads to the conclusion that the flapping mode of instability dominates the noise radiation process of supersonic jets. At a jet temperature of 1370 K, supersonic instability waves are predicted to dominate the noise radiated at high frequency at narrow angles to the jet axis.
Analysis of gastroschisis case series for geographic clustering

ALEXANDER FRIEDMAN, JENNIFER BALLARD DWAN, STEPHEN CARR, Brown University, Women & Infants’ Hospital of RI, Maternal-Fetal Medicine, Providence, Rhode Island OBJECTIVE: Clinical experience suggests a cluster of gastroschisis cases occurring in 2005. We aimed to determine if a geographic clustering of cases existed and to identify possible factors playing a role in gastroschisis cases. STUDY DESIGN: We performed a retrospective chart review of gastroschisis cases between 2001 and 2005. Women who delivered an infant with gastroschisis at Women and Infants’ Hospital during this period were identified using hospital discharge codes and records from our Prenatal Diagnostic Center. Each chart was reviewed for medical and demographic information including geographic location, smoking status, age, and race. RESULTS: 29 women living in Rhode Island were identified for inclusion in the study. Median age for the cohort was 23 years old (IQR 20-25). 43% of women reported using tobacco. 46% of cases were white, 36% were Latina, 11% were Asian, 3.5% were African-American, and 3.5% of other or unspecified race. Incidence of gastroschisis averaged 3.68/10,000 births in 2001-2004 and 6.67/10,000 births in 2005, an increase of 51% between 2004 and 2005. In 2005, 8 cases delivered within 4 months from 4 proximal zip codes. CONCLUSION: The temporal and geographic cluster of cases we experienced in 2005 suggests an environmental etiologic agent may play a role in the occurrence of gastroschisis. Rhode Island Department of Health is currently investigating possible etiologies for this cluster of cases.
Developmental Regulation of β1 Integrins during Angiogenesis in the Central Nervous System

Abstract We examined β1 integrin expression during angiogenesis in the developing mouse CNS. Maturation of blood vessels was accompanied by three main events: (1) marked upregulation of β1 integrin expression; (2) a switch in β1 integrin expression, from α4 and α5 at postnatal day 1 to α1 and α6 in the adult; and (3) downregulation of fibronectin and upregulation of laminin expression. Thus, blood vessel maturation was associated with a developmental switch, from fibronectin-mediated signaling early in angiogenesis, to laminin-mediated signaling at later stages. To investigate the potential role of α4 and α5 integrins in angiogenesis, we developed a novel approach to purify endothelial cells from the CNS by selective adhesion to fibronectin. BrdU incorporation showed that fibronectin induced more endothelial cell proliferation than laminin, and antibody-blocking studies revealed that fibronectin mediated its effect via both α4 and α5 integrins. This work provides the first evidence that there is a developmental switch in the use of β1 integrins during angiogenesis. Furthermore, it suggests that regulation of β1 integrin and ECM expression by endothelial cells are important factors influencing vascular development in the CNS.
An Integrated Process Model of Stereotype Threat Effects on Performance

Research showing that activation of negative stereotypes can impair the performance of stigmatized individuals on a wide variety of tasks has proliferated. However, a complete understanding of the processes underlying these stereotype threat effects on behavior is still lacking. The authors examine stereotype threat in the context of research on stress arousal, vigilance, working memory, and self-regulation to develop a process model of how negative stereotypes impair performance on cognitive and social tasks that require controlled processing, as well as sensorimotor tasks that require automatic processing. The authors argue that stereotype threat disrupts performance via 3 distinct, yet interrelated, mechanisms: (a) a physiological stress response that directly impairs prefrontal processing, (b) a tendency to actively monitor performance, and (c) efforts to suppress negative thoughts and emotions in the service of self-regulation. These mechanisms combine to consume executive resources needed to perform well on cognitive and social tasks. The active monitoring mechanism disrupts performance on sensorimotor tasks directly. Empirical evidence for these assertions is reviewed, and implications for interventions designed to alleviate stereotype threat are discussed.
Heterodyne detected nonlinear optical imaging in a lock‐in free manner

We report a compact, cost-effective tuned amplifier for frequency-selective amplification of the modulated signal in heterodyne detected nonlinear optical microscopy. Our method improved the signal to noise ratio by an order of magnitude compared to conventional lock-in detection, as demonstrated through stimulated Raman scattering imaging of live cells and tissues at the speed of 2 μsec/pixel. Application of the tuned amplifier to transient absorption microscopy is also demonstrated. The increased signal to noise ratio allowed epi-detected in vivo imaging of myelin and blood in rat spinal cord with high spatial resolution.
Role of defects in laser damage of multilayer coatings

Laser induced damage to optical coatings is generally a localized phenomenon associated with coating defects. The most common of the defect types are the well-known nodule defect. This paper reviews the use of experiments and modeling to understand the formation of these defects and their interaction with laser light. Of particular interest are efforts to identify which defects are most susceptible to laser damage. Also discussed are possible methods for stabilizing these defects (laser conditioning) or preventing their initiation (source stabilization, spatter particle trapping).
Detection of Clavibacter michiganensis subsp. sepedonicus in Potato Tubers by BIO-PCR and an Automated Real-Time Fluorescence Detection System

Ring rot of potato, caused by Clavibacter michiganensis subsp. sepedonicus, is one of the most regulated diseases of potatoes world wide. The organism is often difficult to detect in symptomless tubers because of low populations and slow competitive growth on available media. Polymerase chain reaction (PCR) primers and a fluorescent probe for use in the Perkin Elmer 7700 automated real time PCR detection system (TaqMan) were designed from a C. michiganensis subsp. sepedonicus-specific genomic DNA fragment for development of a BIO-PCR assay for C. michiganensis subsp. sepedonicus in potato tubers. Results of screening the primers with strains of C. michiganensis subsp. sepedonicus and other bacteria showed the primers to be specific. A total of 30 naturally infected ring rot suspect tubers were sampled by the core extract, shaker incubation procedure and assayed by (i) plating aliquots onto agar media, (ii) classical PCR, and (iii) BIO-PCR. In all, 4 tubers were positive by agar plating and pathogenicity tests, 8 by classical TaqMan PCR, and 26 by TaqMan BIO-PCR. We conclude that BIO-PCR combined with the TaqMan automated closed detection system is a rapid, reliable method of assaying large numbers of potato tuber extracts for C. michiganensis subsp. sepedonicus. Furthermore, for a large central laboratory running large numbers of PCR assays, the high-throughput TaqMan system can reduce costs per sample over the more labor-intensive classical PCR.
Cystic fibrosis as a disease of misprocessing of the cystic fibrosis transmembrane conductance regulator glycoprotein.

This work was supported by the National Institute of Diabetes and Digestive and Kidney diseases of the National Institute of Health. The author is the Richard O. Jacobson Professor in Molecular Medicine at the Mayo Foundation.
Ultrafast X-ray Diffraction and Absorption: New Light on Phase Transition Dynamics.

I will discuss recent and current applications of femtosecond x-rays to studies of phase transitions in condensed matter. I will describe diffraction with Ka bursts from femtosecond-laser plasmas, as well as progress in ultrafast x-ray absorption spectroscopy of strongly correlated solids at the Advanced Light Source in Berkeley.