cssi/SciSciGPT-SciSciNet huggingface dataset:
Hereditary hemochromatosis since discovery of the HFE gene.

Background: Hereditary hemochromatosis is an inherited disorder of iron metabolism that is characterized by excessive iron deposition in major organs of the body. Chronic increased iron absorption leads to multiorgan dysfunction. Since the discovery of the gene responsible for the majority of cases, research has progressed rapidly to identify the gene product, the effects of mutations, and the implications for different populations. The protein product of the HFE gene is a transmembrane glycoprotein, termed HFE, that modulates iron uptake. Mutations in the HFE protein compromise its function and produce disease symptoms. Two mutations, C282Y and H63D, have been linked to the majority of disease cases. Approach: We reviewed the recent literature for the molecular basis of hereditary hemochromatosis. Genotypic information was combined with biochemical and clinical phenotypic information to achieve a better understanding of the disease mechanism. Content: This review provides a comprehensive discussion of known mutations in the HFE gene and their phenotypic expression. Diagnostic criteria using molecular genetic techniques in conjunction with traditional biochemical tests are provided. Current methods and limitations of molecular testing are examined in detail. A strategy for population screening and an algorithm for diagnosis that incorporates molecular testing are presented. Treatment by therapeutic phlebotomy and the use of blood obtained from hemochromatosis patients are discussed. Summary: Although the disease mechanism has not been completely elucidated, phenotypic and penetrance data are becoming available. Controversy still exists concerning the role of genetic testing in diagnosis and population screening.
Evaluating Proportions of Undetected Geological Events in the Case of Erroneous Identifications

Some geological events occur infrequently but still have a significant impact upon reservoir characteristics. By their very nature, however, it can be difficult to properly estimate the proportions of uncommon events because they may not appear during limited sampling. For example, even with 40 observations and an event proportion of 0.05, there is a 0.13 chance that no events will be observed. We provide some results and guidance concerning methods to estimate proportions when such events are not detected. Two cases are discussed, estimating proportions without errors in identification and estimating proportions when errors may arise. It is well-known that the distribution of possible proportions in the error-free case can be calculated using Bayesian analysis. If one assumes a standard uniform distribution as the prior for the proportion, Bayesian analysis gives a Beta distribution for the posterior. The situation becomes more complicated, however, when detection errors are included; the true proportion has a distribution consisting of several Beta distributions. The difference in results between the error-free and with-error situations can be considerable. For example, when 10 error-free observations are made and no uncommon events are detected, there is a 0.50 chance that the true proportion exceeds 0.06 and a 0.10 chance that it exceeds 0.19. Including the effects of erroneous identifications, however, increases the median proportion to 0.09 and the upper decile to 0.27. We also examine the case where there may be prior geological information, which can be incorporated by amending the prior distribution of the proportion. We find that the use of such a prior makes little difference unless there are very few observations or there are major differences between the anticipated and the observed proportions.
A systems science approach to fatigue management in research and health care

The purpose of this article was to highlight innovative analytic approaches in symptom science. Complex systems modeling is discussed using fatigue as an example. Fatigue is a common symptom among individuals of any age. It can be acute or chronic, and it can vary across the day and on weekends compared with weekdays. Fatigue can overlap with other symptoms, has many dimensions, and impacts daily function as well as society at large. With the complexities surrounding symptom science, innovative models are needed to advance our understanding of factors within the person, contextual and situational factors, and workplace or health care system factors that impact the symptom experience. Advances in methodologies, such as complex systems modeling, allow for more innovative methods to study the complexities of the symptom experience, design better ways to intervene and manage symptoms, and ultimately improve outcomes related to symptom management, quality of life, and health care utilization.
On the long-run outcome of the Lewis-Nurkse international growth process

Abstract This essay formalizes the model of international growth advanced by W. Arthur Lewis in his 1979 Nobel Prize address and by Ragnar Nurkse in the 1950's. Both of them employed the model to support their respective cases for pursuit of a ‘balanced growth’ strategy by the LDC's. The purpose of the formalization undertaken here is to examine the theoretical consequences for the secular ratio of LDC to MDC incomes as the Lewis-Nurkse growth process unfolds. The paper explores whether or not growth in Lewis-Nurkse fashion must mean persistent poverty for the LDC's. In addition, the formalization provides an explicit characterization of economic ‘dependence’.
Viewpoint: International Traffic in Arms Regulations—Controversy and Reform

The International Trade in Arms Regulations (ITAR) have, for decades, played a crucial role in shaping the movement of sensitive technology from the United States to the world. Originally intended to ensure military dominance, the ITAR regime is seen by some as stifling the competitiveness of American industry. A list known as the United States Munitions List (USML) contains the items subject to the ITAR export controls. This list includes clearly dangerous military technology such as missile navigation systems and fighter jet avionics but also includes seemingly benign items, such as coolant hoses or tape recorders for spacecraft. Among the items considered controversial are a number related to the space industry. An incident in the early 1990s began a jurisdictional tug of war. The United States strengthened its grip on the export of space technology. In the last two decades, some have observed a decline in the competitiveness of American industry. The content of the USML should be reviewed based not on...
Transumbilical single‐port laparoscopic partial nephrectomy in a pig model

Study Type – Therapy (case series) Level of Evidence 4 OBJECTIVE To determine the feasibility, instrumentation, and learning curve for single-port laparoscopic partial nephrectomy (SPLPN) in a pig model. MATERIALS AND METHODS Ten transumbilical SPLPN were performed using the R-Port (Advanced Surgical Concepts, Wicklow, Ireland) multi-instrument port, a 5-mm flexible laparoscope (Olympus Surgical, Orangeburg, NY, USA), and custom-engineered articulating needle drivers, graspers, and scissors (Cambridge Endo, Framingham, MA, USA). After general anaesthesia, the pig was placed in the flank position. After umbilical placement of the R-Port, Gerota’s fascia was incised and hilar dissection performed with the newly engineered articulating instruments. Either the upper or lower pole of the kidney was scored and excised after placing a bulldog clamp on the renal pedicle. The bolsters were prepared with absorbable haemostat, placed at the site of excision, and secured with polyglactin sutures. RESULTS A fascial incision of ≥2.5 cm should be made to allow adequate room for passing the instruments. Also, use of the 5 mm flexible laparoscope minimizes instrument crowding and allows for optimal visualization. The mean (sd, range) time for hilum dissection was 12.2 (4.3, 7–20) min, while that for total excision was 9.8 (1.7, 8–12) min. Modified suturing techniques were developed to achieve reconstruction in a small working space. Specialized instrumentation is essential for a successful SPLPN with no need for an additional port for triangulation. The mean duration of intracorporeal suturing was 27.7 min (declining from 40 to 15 min). The total ischaemia time decreased from 50 min in the first case to 27 min in the last (mean 37.4 min). The mean estimated blood loss was 81.1 (31.7, 50–150) mL. CONCLUSIONS SPLPN is technically feasible but further refinement of instrumentation and techniques is needed to decrease the ischaemia time and optimize the procedure.
Precipitation over South America during the Last Glacial Maximum: An analysis of the “amount effect” with a water isotope-enabled general circulation model

Low latitude paleoclimate records from speleothem δ 18O measurements are often considered to reflect variations in precipitation amounts. Here we test this interpretation with a water isotope enabled atmospheric general circulation model, comparing modern and Last Glacial Maximum (LGM) controls on the δ 18Op in Brazil. We argue that the δ 18Op is determined by the contributions from local evaporation (high δ 18O) versus water vapor convergence to the region (low δ 18O). Our analysis indicates that the amount effect, commonly used to infer precipitation amount from δ 18Op in low latitude regions, works only where the isotopic composition of incoming vapor stays relatively constant such as in coastal regions of the subtropics. If the isotopic composition of incoming vapor has changed as a result of the variations in the upstream rainout, δ 18Op cannot be used to estimate local precipitation. Our analysis supports the increase of precipitation over northeastern Brazil region during the LGM.
Epileptiform activity in hippocampal slice cultures with normal inhibitory synaptic drive

The synaptic events responsible for epileptiform burst discharge are often difficult to define. Blockade of inhibition has been used to produce epileptiform events, but it is unclear whether increased excitatory activity in the presence of normal inhibition can also result in burst discharge. In the hippocampal slice culture preparation, a small percentage of cultures exhibit spontaneous bursts. To determine whether the absence of inhibitory postsynaptic potentials (IPSPs) is responsible for these spontaneous bursts, we applied the glutamate antagonist, kynurenic acid (KYN) to block burst activity, and unmask any underlying IPSPs. KYN (10 mM) quickly reduced synaptic activity with concomitant loss of burst discharge. Washout of KYN resulted in a gradual return of synaptic activity, during which time both fast and slow IPSPs were clearly observed. As burst activity returned to control levels, excitatory postsynaptic potentials (EPSPs) were increasingly superimposed within the inhibitory events, obscuring (but not eliminating) the IPSPs. In these hippocampal slice cultures, therefore, epileptiform bursts appear to be the result of an abnormally high level of excitatory synaptic drive, not a reduction in inhibition.
Treatment of Helicobacter pylori infection.

Summary Helicobacter pylori infects the human stomach and is associated with chronic gastritis, peptic ulcer disease and gastric cancer. Most patients with peptic ulcers are infected with H pylori . These patients suffer a high relapse rate following initial healing of the ulcer with anti-secretory agents. The rate of relapse can be greatly diminished following successful eradication of the organism. Although experience is still being accumulated, it is reasonable to use eradication therapy in any patient with H pylori positive active peptic ulcer disease. Combination triple and dual therapy regimens are effective but the search continues for better therapies. This review outlines the current evidence regarding which, when, how and with what H pylori infected patients should be treated.
Preventing Hepatitis B Transmission in the Perioperative Environment: Focus on Policies and Procedures

Health care workers can become infected with the hepatitis B virus through direct contact with blood or other potentially infectious materials during the performance of their duties. Vaccination is the best way to prevent transmission of hepatitis B in the perioperative setting. The next best thing is to have rational policies that are followed by all and are based on the Occupational Safety and Health Administration Bloodborne Pathogen Exposure Standard. Other measures can include modifying work practices, reengineering needed sharps, and eliminating unsafe sharps in the health care environment. All levels of staff, including physicians, registered nurses, and surgical technicians, must be involved in the development of the policy, compliance with procedures and policies, and periodic review.
Suboptimal reporting of adverse medical events to the FDA Adverse Events Reporting System by nurse practitioners and physician assistants

Objectives: The Adverse Events Reporting System (AERS) of the FDA is used to identify toxicities of drugs that are on the market. Nurse practitioners (NP) and physician assistants (PA), having an increasing role in the delivery of medical care, are also needed to participate in post-marketing pharmacovigilance. This study was performed to assess awareness and use of the AERS in voluntary reporting of drug toxicities by NPs and PAs. Methods: A cluster sample survey was issued at the Principles of Gastroenterology for the Nurse Practitioner and Physician Assistant course in August 2010. The survey assessed familiarity with the AERS, the number of adverse events seen and the frequency of reports sent to the AERS. NP and PA responses were compared using the two-tailed Fisher's exact. Results: Of the 92 respondents, 67 (72%) were NPs and 24 (26%) PAs. Of the 50 (54%) respondents that reported being familiar with the AERS system, 20 (40%) incorrectly identified the methods to report using the AERS. Overall repo...
Reactivity of Magnesium Surfaces during the Formation of Grignard Reagents

A reaction cell which allows for photomicrographic observation of magnesium surfaces during formation of Grignard reagents is described. As the reaction proceeds, a finite number of discrete sites initiate relatively rapidly. Following this stage, the reactive area increases by the growth of sites rather than by the initiation of new sites. Sites are randomly located across the magnesium surface (neither clustered nor dispersed) consistent with their formation at crystalline defects or metallic impurities. Various methods of magnesium surface activation are tested. For example, iodine and ferric chloride increase reactivity by increasing the density of reactive sites and by increasing the rate at which individual sites react. Scratching the magnesium surface increases reactivity by decreasing the time required for initiation of reactive sites. A mercury/magnesium amalgam provides a uniformly reactive surface, but the reaction rate is very slow.
J‐wire Facilitates Retrograde Manipulation of Ureteric Calculi Prior to Extracorporeal Shock Wave Lithotripsy

Summary— During a 13-month period, 55 patients underwent attempted retrograde manipulation for ureteric lying above the pelvic brim. The mean stone burden was 11 mm (range 5–21); 41 stones (75%) were primary ureteric calculi and 14 (25%) were fragments resulting from extracorporeal shock wave lithotripsy to renal calculi. The method of retrograde manipulation was recorded prospectively. Retrograde flushing through an 8F angiography catheter with a mixture of saline and lignocaine gel was successful in 27 patients (49%). The insertion of a J-wire through the angiocath allowed for successful manipulation in a further 17 patients (31%). Retrograde manipulation was impossible in 11 patients (20%). There were 4 complications (7%), none attributable to the use of a J-wire.
Gender, sex-type and cognitive distortion: Self-perceptions of social competence among mild depressives

In this study we investigated the relationship of gender and sex-type to the accuracy of self-perceptions of social competence in depressed and nondepressed college students. Three hundred and eighty students were initially screened and based on their diagnostic category, 82 participants (40 depressed; 42 nondepressed) were selected and randomly assigned to small discussion groups. Participants rated themselves and were rated by group peers and trained observers on a measure of social competence. Analyses of the social competence ratings by sex, sex-type, and diagnostic category revealed that the peer and self-ratings of the nondepressed participants were significantly higher than those ratings of the depressed participants. Observers failed to differentiate between the depressed and nondepressed participants on the measure of social competence; all observers’ ratings were significantly lower than peer of self-ratings. These anomalous results were explored further via post-hoc analyses. No significant gender differences or differences due to the participants’ sex-types emerged. The implications of these results for the cognitive distortion and social skills deficits theories of depression were discussed.
Ferromagnetism induced by planar nanoscale CuO inclusions in Cu-doped ZnO thin films

We report ferromagnetism above $300\phantom{\rule{0.3em}{0ex}}\mathrm{K}$ in $\mathrm{Zn}\mathrm{O}:x\mathrm{Cu}$ ($x$ in at. %) sputtered thin films. For $xl1$, a large magnetic moment of $1.6\phantom{\rule{0.3em}{0ex}}{\ensuremath{\mu}}_{B}∕\mathrm{Cu}$ was observed, which decreases monotonically with increasing $x$. We find evidence that the ferromagnetic moment is due to Cu-O planar nanophase inclusions in ZnO basal planes. The presence of CuO nanophase is confirmed by transmission electron microscopy, x-ray diffraction, and Raman spectroscopy studies. These inclusions are present even for $xl3$, where Cu-O structures of a few nanometers in size are observed. Field-cooled and zero-field-cooled magnetization measurements show a bifurcation for temperatures below $300\phantom{\rule{0.3em}{0ex}}\mathrm{K}$.
Unsupervised Learning with Mini Free Energy

In this paper, we present an unsupervised learning with mini free energy for early breast cancer detection. Although an early malignant tumor must be small in size, the abnormal cells reveal themselves physiologically by emitting spontaneously thermal radiation due to the rapid cell growth, the so-called angiogenesis effect. This forms the underlying principle of Thermal Infrared (TIR) imaging in breast cancer study. Thermal breast scanning has been employed for a number of years, which however is limited to a single infrared band. In this research, we deploy two satellite-grade dual-color (at middle wavelength IR (3 − 5µm) and long wavelength IR (8−12µm)) IR imaging cameras equipped with smart subpixel automatic target detection algorithms. According to physics, the radiation of high/low temperature bodies will shift toward a shorter/longer IR wavelength band. Thus, the measured vector data x per pixel can be used to invert the matrix-vector equation x=As pixel-by-pixel independently, known as a single pixel blind sources separation (BSS). We impose the universal constraint of equilibrium physics governing the blackbody Planck radiation distribution, i.e., the minimum Helmholtz free energy, H = E − ToS. To stabilize the solution of Lagrange constrained neural network (LCNN) proposed by Szu et al., we incorporate the second order approximation of free energy, which corresponds to the second order constraint in the method of multipliers. For the subpixel target, we assume the constant ground state energy Eo can be determined by those normal neighborhood tissue, and then the excited state can be computed by means of Taylor series expansion in terms of the pixel I/O data. We propose an adaptive method to determine the neighborhood to find the free energy locally. The proposed methods enhance both the sensitivity and the accuracy of traditional breast cancer diagnosis techniques. It can be used as a first line supplement to traditional mammography to reduce the unwanted X-rays during the chemotherapy recovery. More important, the single pixel BSS method renders information on the tumor stage and tumor degree during the recovery process, which is not available using the popular independent component analysis (ICA) techniques.
Global Leadership Theory: Theoretical Roots, Principles and Possibilities for the Future:

This article presents a brief critical overview of leadership theory and curriculum and suggests alternatives to meet the challenges of a changing global society. Its main purposes are twofold: 1) to provide a rationale for, and propose the inclusion of paradigms and perspectives that have been absent from traditional leadership theories and programs; and 2) to initiate a theoretical discussion on democratic leadership theories on a global scale in gifted education. The author does not intend to present the ideas set forth in this article as the final version of a global leadership theory, but as a working model that is more inclusive than the models presently in use in the field.
SU-FF-J-02: Impact of Cross Scatter On CNR in Fluoroscopic Images Taken with a Dual Flat Panel X-Ray Imaging System

Purpose: To examine the impact of cross scatter on contrast‐to‐noise ratio (CNR) in fluoroscopic images acquired with a dual flat‐panel x‐ray imagingsystem.Method and Materials: An x‐ray imagingsystem has been developed consisting of two tube/detector pairs mounted orthogonally; each chain includes a 40×30 cm amorphous silicon flat panel detector. A timing system was developed to offset the exposures of each imaging chain relative to the detector cycle which remained synchronous for both imagers. The amount of cross scatter present is dependent on several factors: kVp, mAs, time between exposures, detector lag, and object size. Several cylindrical phantoms that incorporate areas of varying contrast were used to perform CNR measurements. CNR was taken as the relative contrast between two ROIs divided by the noise, the average of the standard deviation of the contrast measured in 15 images. Effects of cross‐scatter were determined by comparing CNR when both tubes were fired to CNR when only one tube was fired. Additionally, the dependence of CNR on kVp and the number of scrub frames was measured. Since cross scatter is non‐uniform across the imaging plane, CNR was measured using ROIs in various regions of scatter intensity across the detector.Results: Preliminary results show that contrast and CNR can be reduced by up to factors of approximately 10 when cross scatter is present. Contrast reductions are greater at lower kVp. CNR reductions are greater at higher kVp. By inserting scrub frames and time delays, contrast and CNR can be restored to near the values observed without cross scatter. Conclusion: Cross scatter can be substantial in dual x‐ray projection imaging. It's effects vary with kVp and can be alleviated by scrub frames and tube timing. Conflict of Interest: This research is supported in part by Varian collaboration.
Universal transition between Hamiltonian and dissipative chaos

The inverse bifurcation sequence in one-dimensional maps is modified in two-dimensional ones in a universal way. Two-piece, four-piece, etc., strange attractors are eliminated one by one as the Jacobian approaches one. Renormalization theory around the Hamiltonian ${T}^{\mathrm{*}}$ leads to universal behavior including universal strange attractors.
N-acetyl-L-tryptophan in Claviceps purpurea PRL 1980

Abstract Claviceps purpurpea PRL 1980 converts L -tryptophan to N -acetyl- L -trytophan. There is little acetylation of D -tryptophan. Added N -acetyl- L -trypotophan. has no effect on alkaloid production. L -Tyrosine addition results in production of a compound which is probably N -acetyltyrosine and also causes accumulation of 4-γ,γ-dimethylally-tryptophan.
Local signaling within stem cell niches: insights from Drosophila

Tissue stem cells are found in specialized microenvironments (niches) where they are exposed to diverse systemic and local signals that are integrated with cell intrinsic factors to regulate stem cell behavior. In general, systemic signals are utilized to coordinate the response of tissues to acute or long-term changes that affect the whole organism, such as variations in nutrient availability or aging. In contrast, local signaling regulates tissue maintenance by balancing stem cell self-renewal with differentiation under homeostatic conditions and in response to local damage. In this review, we highlight the role of the JAK–STAT pathway in two Drosophila stem cell systems, the testis and intestine, and compare and contrast how activation of this pathway leads to tissue maintenance under both homeostatic conditions and in response to stress or injury.
Effects of acute and chronic imipramine administration on conflict behavior in the rat: a potential "animal model" for the study of panic disorder?

Although numerous animal procedures have been employed in the study of generalized anxiety and agents effective in treating generalized anxiety, an analogous “behavioral model” for the study of panic disorder does not exist. In the present study, the effects of imipramine were examined in a potential “animal model” for panic disorder, the conditioned suppression of drinking (CSD) paradigm. In daily 10-min sessions, water-deprived rats were trained to drink from a tube that was occasionally electrified (0.5 mA). Electrification was signalled by a tone. Imipramine was administered both in an acute (3.5–20 mg/kg, IP) and a chronic (2.5 mg/kg, IP, twice daily for 5 weeks) regimen. Acute administration of imipramine resulted in a decrease in the number of shocks accepted and a decrease in water intake. In contrast, chronic administration of imipramine resulted in a gradual increase in the number of shocks received in CSD sessions over the course of several weeks of testing. This time-dependent increase in punished responding in the CSD observed during chronic imipramine treatment parallels the time-dependent reduction in the severity and frequency of panic attacks in panic disorder patients receiving chronic imipramine. Thus, the CSD paradigm might serve as an “animal model” for the study of panic disorder and potential anti-panic agents.
Thermochemistry of the gadolinium-copper interface.

We have characterized the thermochemistry of the gadolinium-copper interface using valence-band photoemission. We find that the copper substrate binds strongly with the gadolinium overlayer, based upon valence-band binding-energy shifts that occur with increasing gadolinium coverages on Cu(100). The net potential for copper at the interface is 3.82 eV/atom which is some 0.51 eV/atom greater than the heat of sublimation for copper. The strong bonds formed between copper and gadolinium provide a thermochemical driving force for copper gadolinium-alloy formation. We observed a surface-to-bulk core-level shift for gadolinium of 0.3--0.4 eV. We also observed a Cu 3d binding-energy increase of 0.73 eV with increasing coverage.
How Does the Brain Sense Osmolality

For nearly 60 years, we have known that the brain plays a pivotal role in regulating the osmolality of body fluids. Over this time period, scientists have determined the structure and function of arginine vasopressin and its receptors, the role of the posterior pituitary as a storage site, and the determinants of vasopressin release. The cellular mechanisms by which the kidney responds to vasopressin are also well understood. One area that remains unclear is the neural mechanisms underlying osmoreception. New findings have implicated the TRPV family of cation channels as osmo-mechanoreceptors that may mediate the neuronal responses to changes in systemic tonicity. This topic is reviewed here.
Electron nuclear double resonance evidence for bifurcated hydrogen bonds in KH2PO4: Possible role in the ferroelectric transition

Abstract Electron nuclear double resonance measurements on OH⋯O protons in KH2PO4, using SeO3−4 as a probe, demonstrate that the superhyperfine tensor for the “far” (O⋯H) proton is dominated by dipolar interaction with the unpaired electron in the 2pz orbital of an oxygen to which a “close”, i.e., O-H, proton is attached. This result implies that each hydrogen is involved in a bifurcated hydrogen bond. This conclusion was supported by a reanalysis of the earlier reported ENDOR data that was obtained using the AsO4−4 radical as a probe in KH2AsO4, in particular, by the fact the isotropic part of the tensor for the “far” protons is sizable (2.8 MHz) and has same sign (negative) as that of the “close” proton. Moreover, the various O⋯H distances and bond angles for the proposed bifurcated hydrogen bonding are comparable to the literature values for these parameters for carbohydrates. These findings provide the basis for a new contribution toward the role of hydrogens in the mechanism of phase transition in the KDP-type ferroelectrics.
Smile: a computer program for partitioning of programmed logic arrays

Abstract This paper presents a new approach to optimal topological design of PLAs (programmed logic arrays). In particular we address the array partitioning problem and the implementation of partitioned arrays as block folded or parallel connected PLAs. We present a graph theoretic interpretation of the problem and an efficient heuristic algorithm. A computer program, Smile, is described and experimental results are reported.
Convergent extension by intercalation without mediolaterally fixed cell motion

We construct and implement a stochastic model of convergent extension, using a minimal set of assumptions on cell behavior. In addition to the basic assumptions of volume conservation, random cell motion, and cell-cell and cell-ECM adhesion, and a non-standard assumption that cytoskeletal polymerization generates an internal pressure tending to keep cells convex, we find that we need only two conditions for convergent extension. (1) Each cell type has a particular aspect ratio towards which it regulates its geometry. We do not require that cells align in a specific orientation, e.g. to be oriented mediolaterally. (2) The elongating tissue is composed of cells that prefer to be elongated, and these cells must be accompanied by cells which prefer to be round. The latter effectively provide a boundary to capture. In simulations, our model tissue extends and converges to a stacked arrangement of elongated cells one cell wide, an arrangement which is seen in ascidian notochords, but which has not been observed in other models. This arrangement is achieved without any direct mediolateral bias other than that which is provided by the physical edge of the adjacent tissue.
Effect of high-energy X-ray irradiation on creep mechanisms in bone and dentin

Abstract Under long-term loading creep conditions, mineralized biological tissues like bone are expected to behave in a similar manner to synthetic composites where the creeping matrix sheds load to the elastic reinforcement as creep deformation progresses. To study this mechanism in biological composites, creep experiments were performed at 37 °C on bovine compact bone and dentin. Static compressive stresses were applied to the samples, while wide- and small-angle scattering patterns from high energy synchrotron X-rays were used to determine, respectively, the elastic strain in the hydroxyapatite (HAP) platelets and the strain in the mineralized collagen fibril, as a function of creep time. In these highly irradiated biological composites, the reinforcing hydroxyapatite platelets progressively transfer some of their stress back to the softer protein matrix during creep. While such behavior can be explained by damage at the interface between the two phases, it is not consistent with measurements of the apparent moduli – the ratio of applied stress to elastic HAP strain measured throughout the creep experiments by elastic unload/load segments – which remained constant throughout the experiment and thus indicated good HAP/protein bonding. A possible explanation is a combination of X-ray and load induced interfacial damage explaining the shedding of load from the HAP during long term creep, coupled with interfacial re-bonding of the load-disrupted reversible bonds upon unloading, explaining the unaffected elastic load partitioning during unload/load segments. This hypothesis is further supported by finite element modeling which shows results mirroring the experimental strain measurements when considering interfacial delamination and a compliant interstitial space at the ends of the HAP platelets.
Endogenous inhibitor of cyclic nucleotide phosphodiesterase in cultured human epithelial cells

Abstract We have identified an endogenous inhibitor of cyclic nucleotide phosphodiesterase (PDE) activity in cultured human epithelial cells. The inhibitor was non-dialyzable, inactivated by trypsin and boiling, but stable to a 60° C, 30 min. treatment. Separation of inhibitor from PDE was achieved by blue dextran affinity chromatography. PDE was eluted from this column by EDTA, while the inhibitor remained bound and was subsequently eluted with buffer containing cyclic GMP. The inhibitor was active against PDE from several sources including both Ca++ dependent and Ca++ independent forms from bovine brain and retina respectively. These characteristics differentiate the PDE inhibitor from human epithelial cells from those previously described from various bovine tissues.
Preparation for Birth into an O2-Rich Environment: the Antioxidant Enzymes in the Developing Rabbit Lung

To determine if some specific "preparation for birth" occurs in the developing lung to help assure its successful adaptation to a comparatively O2-rich world at birth, we measured the activities of the antioxidant enzymes in the developing lungs of rabbit fetuses from 10 d before parturition to several days after birth. Superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GP) activities showed similar maturational patterns with significant increases in activity, compared with earlier gestational levels, during the last 3-5 d before birth. During the final days in utero, SOD and CAT activities increased by approximately 110% and lung GP activity by approximately 200%. There were no parallel changes in lung O2 consumption demonstrable over this same prenatal period.
When Toxic Chemicals Pollute Residential Environments: The Cultural Meanings of Home and Homeownership

Perceptions of environmental pollution are affected by attitudes about the particular environment being polluted. When toxic chemicals invade residential environments, Americans perceive multiple threats. Besides possible health risks and financial losses, such pollution represents an attack on the important cultural institutions of home and homeownership. Research in several communities where toxics have affected household drinking water illuminates specific meanings of home in American culture, and demonstrates that these ideas shape perceptions of pollution that occurs where people live. Personnel from government environmental agencies, public health officials, and engineers who work with communities experiencing pollution problems need to be more sensitive to the cultural assumptions and values that shape people's perceptions of pollution. Greater attention to cultural attributes of home and homeownership would enhance efforts at prevention and resolution of toxic problems in residential environments.
Modifications of the Euclidean algorithm for isolating periodicities from a sparse set of noisy measurements

Modifications of the Euclidean algorithm are presented for determining the period from a sparse set of noisy measurements. The elements of the set are the noisy occurrence times of a periodic event with (perhaps very many) missing measurements. This problem arises in radar pulse repetition interval (PRI) analysis, in bit synchronization in communications, and in other scenarios. The proposed algorithms are computationally straightforward and converge quickly. A robust version is developed that is stable despite the presence of arbitrary outliers. The Euclidean algorithm approach is justified by a theorem that shows that, for a set of randomly chosen positive integers, the probability that they do not all share a common prime factor approaches one quickly as the cardinality of the set increases. In the noise-free case, this implies that the algorithm produces the correct answer with only 10 data samples, independent of the percentage of missing measurements. In the case of noisy data, simulation results show, for example, good estimation of the period from 100 data samples with 50% of the measurements missing and 25% of the data samples being arbitrary outliers.
Doppler-derived deformation imaging in unsedated healthy adult dogs.

Abstract Objectives To evaluate feasibility, repeatability and reproducibility (R&R) of Doppler-derived deformation imaging (DI) in healthy adult dogs. Animals, materials and methods Forty-nine dogs underwent physical examination, ECG, blood pressure measurement and echocardiography. Doppler-derived DI parameters obtained from six selected Regions of Interest (ROI) within the left ventricle (LV) were: strain (S), systolic strain rate (SSR), strain rate E wave (SRE), and strain rate A wave (SRA). The averages of the six ROIs were calculated and labeled avS, avSSR, avSRE, and avSRA. Randomly selected dogs underwent two echocardiographic studies to evaluate intraoperator (n = 14) and interoperator (n = 17) variability. Results DI data were obtained in 87.2% of dogs and 77.2% of ROIs. Compared to controls, avSSR was significantly reduced in Doberman Pinchers (DP) and it was increased in dogs 30 kg. The intraoperator Coefficient of Variability (CV) for some ROIs was greater than 15% but for averaged measurements it was ≤ 5.0%. Interoperator CV varied widely but were all Conclusions The CV for Doppler-derived DI varied widely. Averaging values from multiple ROIs improved R&R. DI may help elucidate differences in LV mechanics between canine breeds.
A comparative study of the influence of dimethyl sulfoxide on iodine metabolism in male Long-Evans rats and male CF1 mice.

Young adult, male, Long-Evans rats 60–70 days of age, and young adult, male CF1 mice, 90–100 days of age were injected with 85% dimethyl sulfoxide (DMSO). Several indices of thyroid function were examined in both mice and rats: iodide transport (T/S ratio), the response of the thyroid gland to injection of an acute substantial iodide load such as organification of the trapped iodide, and thyroidal 131I uptake as a function of time both in vivo and in vitro. There was no significant difference between saline-injected and DMSO-injected groups in thyroid: serum radioiodide concentration ratios (T/S) in either rats or mice. The injection of 200 μg carrier iodide elicited the acute Wolff-Chaikoff block in thyroid hormone synthesis in rats and mice and was not influenced by prior injection of 85% DMSO. Chromatographic analyses of thyroid Pronase hydrolysates in saline-injected and DMSO-injected groups of rats and mice revealed a pattern of distribution in thyroid labeling which was similar: a marked reduction in the percentage of labeled iodotyrosines and iodothyronines, an increased percentage of 131I-labeled iodide, and elevated monoiodotyrosine: diiodotyrosine ratios. DMSO did not influence thyroidal 131I uptake either in mice or rats. These findings indicate that 85% DMSO did not exert any significant influence on thyroid function either in the rat or mouse.
Ureogenesis in elasmobranch fishes

Abstract 1. (1) The following reactions have been directly demonstrated in extracts from acetone powders prepared from the livers of several species of elasmobranch fishes: (i) carbamyl phosphate+ornithine → citrulline (ii) citrulline+aspartate → urea. 2. (2) There is strong circumstantial evidence that reaction (ii) proceeds by way of argininosuccinate and arginine. 3. (3) Attempts to demonstrate a synthesis of carbamyl phosphate were unsuccessful.
Nucleic acid aptamers for clinical diagnosis: cell detection and molecular imaging

Nucleic acid aptamers have recently attracted significant attention in the field of clinical diagnosis because they have numerous merits, such as high affinity, high specificity, small size, little immunogenicity, stable structures, and ease of synthesis. This review focuses on discussing the potential applications of aptamers in cell detection and molecular imaging. For the ex vivo cell detection, this review discusses the status of five strategies: endogenous nucleic acid analysis, flow cytometry analysis, nanoparticle-based cell sensing, microfluidic cell separation, and histological examination. This review also discusses in vivo molecular and cell imaging by introducing aptamer-based molecular imaging, cell imaging, and integrated imaging and therapy. On the basis of the status of these promising studies, this review summarizes several challenging issues and unmet needs that may require more effort or attention in the future.
Stimulation of tracheal slowly adapting stretch receptors by hypercapnia and hypoxia

Abstract We studied the response of tracheal slowly adapting stretch receptors (SARs), whose activity was recorded from the peripheral cut end of the right vagus nerve, in newborn and adult dogs during hyperoxic hypercapnia and isocapnic hypoxia. Tracheal receptors only were studied since it was possible to maintain the parasympathetic efferent supply partially intact (contralateral vagus nerve and superior laryngeal nerve). The animals were anesthetized and passively ventilated with the chest open. A stimulatory effect was found in 9 out of 20 puppies for hypercapnia and in 3 out of 10 for hypoxia. The maximum amount of stimulation ranged from 114 to 556% of the control discharge for hypercapnia and from 110 to 387% for hypoxia. In the adult dog CO2 stimulated tracheal SARs in 11 out of 16 dogs (103–404% control) while hypoxia stimulated SARs in 9 out of 13 animals (109–268% control). The stimulatory effect was greater during expiration and for hypercapnia, decreased in intensity with time. This excitatory action was eliminated by cold block of the contralateral vagus nerve or atropine administration, suggesting that the stimulation was mediated by smooth muscle contraction. These findings support the notion that airway stretch receptors are activated not only by passive distension of the airways, but also by an active contraction of the tracheobronchial smooth muscle.
Sorafenib inhibits cAMP-dependent ERK activation, cell proliferation, and in vitro cyst growth of human ADPKD cyst epithelial cells

In autosomal dominant polycystic kidney disease (ADPKD), aberrant proliferation of the renal epithelial cells is responsible for the formation of numerable fluid-filled cysts, massively enlarged kidneys, and progressive loss of renal function. cAMP agonists, including arginine vasopressin, accelerate cyst epithelial cell proliferation through protein kinase A activation of the B-Raf/MEK/extracellular signal-regulated kinase (ERK) signaling pathway. The mitogenic effect of cAMP is equally potent and additive to growth factor stimulation. Here, we determined whether Sorafenib (BAY 43–9006), a small molecule Raf inhibitor, inhibits proliferation of cells derived from the cysts of human ADPKD kidneys. We found that nanomolar concentrations of Sorafenib reduced the basal activity of ERK, inhibited cAMP-dependent activation of B-Raf and MEK/ERK signaling, and caused a concentration-dependent inhibition of cell proliferation induced by cAMP, epidermal growth factor, or the combination of the two agonists. Sorafenib completely blocked in vitro cyst growth of human ADPKD cystic cells cultured within a three-dimensional collagen gel. These data demonstrate that cAMP-dependent proliferation of human ADPKD cyst epithelial cells is blocked by Sorafenib and suggest that small molecule B-Raf inhibitors may be a therapeutic option to reduce the mitogenic effects of cAMP on cyst expansion.
Prospective comparison of R-mix shell vial system with direct antigen tests and conventional cell culture for respiratory virus detection.

Abstract Background and objectives Conventional cell culture (CC) has limited clinical utility as a result of the extended incubation period often required for virus isolation. Alternative methodologies have been introduced in an effort to improve turnaround times. One such system, the R-mix™ shell vial is discussed herein. The study objectives were: (a) to establish R-mix™ testing parameters as compared to direct antigen testing (DAT) and CC, and (b) to assess technical aspects and cost of R-mix™ in a high volume clinical virology laboratory. Study design A prospective analysis of respiratory samples submitted to the clinical virology laboratory between November 2004 and April 2005 was performed. All specimens were inoculated onto R-mix™ shell vials (SV) and CC tubes; and a subset also underwent DAT for influenza A and B and/or RSV. A retrospective estimated cost analysis was made. Results A total of 563 samples were included in the study, which collectively revealed a total of 207 viruses. Sensitivity of R-mix™ for seven major respiratory viruses ranged from 45% to 83% compared to CC and DAT, while mean time to detection (TTD) varied from 1.1 to 1.4 days. In addition to these viruses, 23 picornaviruses, 11 CMV isolates and 5 HSV isolates were detected by CC alone. Conclusions The R-mix™ system has similar sensitivity as CC for the detection of parainfluenza 1–3 and influenza A/B while dramatically reducing the TTD. Furthermore, it is significantly more sensitive and produces more timely results for RSV than CC; yet, neither method offers a diagnostic benefit over rapid DAT for RSV detection. The sensitivity of R-mix™ for adenovirus appears to be significantly lower than that of CC. Lastly, methodologies other than R-mix™ must remain in place under circumstances where identification of other potential viral respiratory pathogens, including herpesviruses and picornaviruses, is desired.
Initial conditions and temporal delays influence preference for foods high in tannins and for foraging locations with and without foods high in tannins by sheep

Abstract Preference for foods is influenced by experience, which in variable environments changes as animals eat foods that differ temporally and spatially in nutrients and toxins. We hypothesized that variability can affect preferences by influencing the contiguity of food ingestion as young animals learn to forage. To test this hypothesis, we fed lambs two biochemically different foods, one with tannins (T—55.5% beet pulp, 30% grape pomace, 4.5% soybean meal, 10% quebracho tannin; 2.4 Mcal, 8% CP) and one without tannins (NT—35% barley grain, 62% alfalfa hay, 3% soybean meal; 3.0 Mcal, 15% CP) in two temporal arrangements: (1) dissociated in two separate feeding bouts (Group 1; Delayed arrangement) or (2) associated in a sequence in the same feeding bout (Group 2; Sequential arrangement). We then determined if these different associations influenced choice of foods and foraging locations. In Trials 1 and 2, NT and T were both at location 1, whereas either NT or T, respectively, was at location 2. In Trials 3 and 4, the choices were similar, but the NT offered was reduced to half the average intake in Trials 1 and 2. Throughout the trials, both groups of lambs preferred NT to T and they spent more time at locations where NT was present. However, lambs conditioned under the sequential arrangement always ate more T than lambs conditioned under the delayed arrangement, even when NT was available ad libitum at both locations. When the amount of NT offered decreased, lambs conditioned under the sequential arrangement foraged longer at locations with both NT and T or with just T. Even when both groups spent similar time at locations with NT and T, lambs conditioned in the sequential arrangement ate more T than lambs conditioned in the delayed arrangement. Thus, conditioning during initial exposure influenced preferences for foods and foraging locations. Our results help explain why the same food may be perceived differently by different animals, and suggest it may be possible to train animals either to use more diverse arrays of foods or, conversely, to be more selective.