cssi/SciSciGPT-SciSciNet huggingface dataset:
Chromosome preparations of opossum leucocytes

C'est la premiere fois que l'on decrit une technique pour la preparation des chromosomes de leucocytes d'opossum. Cette technique a l'avantage d'etre simple et elle permet en outre de preciser les details morphologiques de certains chromosomes de l'opossum. Par exemple, les chromosomesX de la femelle de l'opossum laineux (Caluromys derbianus) sont aisement identifies comme etant la plus petite paire submetacentrique du complement.
The Longevity of Estrogen Pellets

Abstract Lorenz (1943) found that the fat content of cockerels could be increased substantially by subcutaneous implantation of diethylstilbestrol pellets. The general practice has been to implant the pellets about four to six weeks before killing. This time-period has been considered sufficient for maximum fat deposition. Implanting the pellet under the skin at the base of the skull allows for the discarding of any unabsorbed pellet residue with the head, “if” the pellet is not entirely absorbed. Opinions vary concerning the life of the pellets. EXPERIMENTAL Examination of a group of Barred Rock cockerels, fourteen weeks old, that had been implanted with one pellet six weeks before killing revealed pellet residue one-third to one-half of the original pellet size. In order to test the potency of the unabsorbed pellets they were removed and re-implanted in a test with New Hampshire cockerels. One lot was implanted with one unabsorbed pellet, another with . . .
Clarification on the Categorization of Comorbidities

Comorbidities are coexisting diseases that are distinct from the primary illness for which a patient seeks health care services 1. Comorbidity may affect detection, prognosis, therapy, and outcome of the primary disease. We recently published a paper evaluating the role of comorbidities in the survival of patients with myelodysplastic syndromes, in which Charlson index was utilized as the measure of comorbidities 2. Charlson et al. developed a weighted index measure of comorbidities based on medical records review and identified a total of 19 conditions that influence mortality 3. Both the number and the seriousness of comorbid conditions were taken into account. Each of the 19 conditions was assigned a weight (0 - 6) according to its potential for influencing mortality. A patient's comorbidity index would be the sum of all weighted comorbidities. A higher score on the Charlson index indicates a greater burden of comorbid conditions. Later, Deyo et al. adapted the Charlson index for use with the ICD-9-CM diagnostic and procedure codes available in administrative datasets 4. Researchers at the National Cancer Institute subsequently developed a SAS macro to calculate Charlson index for linked SEER*Medicare data (http://healthservices.cancer.gov/seermedicare/program/comorbidity.html). We adopted this method to calculate Charlson index for the more than 2,000 patients included in our study.
Elevated 12-lipoxygenase mRNA expression correlates with advanced stage and poor differentiation of human prostate cancer

Abstract Objectives Prostate cancer is the most frequently diagnosed cancer and the second leading cause of cancer death in males in the United States. The mortality is due mainly to distant metastasis. Therefore, predicting the prognosis of prostate cancer patients is an important clinical problem. Previously, we demonstrated that a 12-lipoxygenase (12-LOX) metabolite of arachidonic acid, 12(S)-hydroxyeicosatetraenoic acid, enhances the invasiveness of prostate cancer cells and that a 12-LOX-selective inhibitor (N-benzyl-N-hydroxy-5-phenylpentanamide) reduces experimental metastasis in animal model systems. In this study, we investigated the potential of 12-LOX as a predictor for the aggressiveness of prostate cancer. Methods The mRNA expression levels of 12-LOX in 122 matching prostate normal and cancerous tissues were measured by quantitative reverse transcription-polymerase chain reaction. Possible association between 12-LOX expression and histologic grade, pathologic and clinical stage, margin positivity, age, and race was analyzed. Results 12-LOX mRNA levels were elevated in cancer cells and the expression associated with poor differentiation and invasiveness of prostate cancer. Overall, 46 (38%) of 122 evaluable patients showed elevated levels of 12-LOX mRNA in prostate cancer tissues compared with the matching normal tissues. A statistically significantly greater number of cases were found to have an elevated level of 12-LOX among T3, high grade, and surgical margin-positive than T2, intermediate, and low grade, and surgical margin-negative prostatic adenocarcinomas. Conclusions Our data suggest that elevation of 12-LOX mRNA expression occurs more frequently in advanced stage, high-grade prostate cancer and that 12-LOX may serve as an indicator for progression and prognosis of prostate cancer. This enzyme also may be a novel target for the development of anti-invasive and antimetastatic agents.
Characterization of solar cells in transportation

Breakages of solar cells mostly depend on the stresses induced in the process, handling and transportation, and also rely on the presence of defect such as crack or micro-crack. Upon transportation, vibration caused by truck (or airplane) typically induces solar cell has crack propagation and performance degradation gradually, but current research still lacks the obvious evidences of characterization to address solar cell performance during shipping. This work proposed to evaluate the performance and defect coherently in solar cell caused by vibration during truck and air transportation, and observed the abnormal electrical data (P mpp , R s , R sh ) and defects such as micro-crack (> 50µm) or breakage. Experimental data showed the breakage rate (breakage cell/ total cell) is 2% only, but degradation rate (abnormal cell / total cell) is accumulated to 6% eventually, that exposed the high potential failure for shipping cells themselves. Consequently, degradation rate is more robust than breakage rate to qualify the quality of cells. In addition, this paper has proposed a new test method to alleviate the reliability obstacles of solar cells, and accelerate the development of cells protection design for transportation.
A new type of high-resolution neutron spectrometer

Abstract The movement of a neutron interferometer transverse to the incoming beam produces an interference pattern in velocity space. A change of the neutron velocity due to the scattering in the sample leads to an observable change in the interference pattern. Such a spectrometer has an extremely high-energy resolution approaching the picoelectronvolt region that is a few orders of magnitude higher than the resolution achievable by neutron spin-echo (NSE) spectrometers. Similar to NSE spectrometers, the resolution is not connected with the monochromatization of the incoming beam. However, in contrast to NSE spectrometers the operation of the proposed spectrometer does not necessarily require a polarized neutron beam. By decoupling the polarization and the resolution new possibilities are opened for the study of magnetic phenomena in solids, where the NSE method is principally not applicable because of neutron precession in the sample. The use of the proposed technique in a low-resolution mode can be useful in combination with triple-axis spectrometers allowing a dramatic improvement in their energy resolution without the use of polarized neutrons, and hence avoiding the problem of parasitic magnetic fields.
On an application of dynamical systems theory to determine all the zeros of a vector function

Abstract A continuous-time dynamical system is constructed and analyzed in this paper to help locate all the zeros of nonlinear vector functions. Lyapunov stability technique is used to show that the zeros of the vector function become asymptotically stable equilibria for this dynamical system. A strict Lyapunov function is constructed to indicate local stability and to estimate the domains of attraction of all equilibria. Manifolds on which the Jacobian of the vector field is singular play a significant role in characterizing the global behavior of the system. Examples are provided to illustrate the extent of the theory. New computational techniques to determine all the zeros of a vector function can be developed based on the dynamical aspects of the theory given in this paper.
AlF/sub 3/-based glass fibres with enhanced optical transmission

A significant reduction in the optical losses of AIF3-based, infrared transmitting fibres has been achieved for the first time. A minimum loss of 0.05dB/m at 2.65μm coupled with extended transparency beyond 4μm and excellent chemical durability makes these fibres excellent candidates for infrared sensing, remote spectroscopy, laser power delivery and active fibre research.
Measurement of bone mineral density: current status.

0 steoporosis has been traditionally defined as a condition of low bone mass accompanied by atraumatic fractures. Recently, more emphasis has been placed on patient bone mineral density in the attempt to identify those at high risk for osteoporotic fracture before these fractures have occurred. As a result, bone densitometry techniques have become increasingly important. Four general methods have been developed and are currently being used for noninvasively measuring bone mineral density at various anatomic sites, both in the axial and in the peripheral skeleton (Table I). While differing in the particular anatomic sites they measure and in their precision, accuracy, and fracture discrimination, all of these methods provide clinically useful measurements of skeletal status and represent major advances in our ability to noninvasively measure bone mass.
Quantitative growth measurement of lesions in hepatic interval CT exams

Standard clinical radiological techniques for determining lesion volume changes in interval exams are, as far as we know, quantitatively non-descriptive or approximate at best. We investigate two new registration based methods that help sketch an improved quantitative picture of lesion volume changes in hepatic interval CT exams. The first method, Jacobian Integration, employs a constrained Thin Plate Spline warp to compute the deformation of the lesion of interest over the intervals. The resulting jacobian map of the deformation is integrated to yield the net lesion volume change. The technique is fast, accurate and requires no segmentation, but is sensitive to misregistration. The second scheme uses a Weighted Gray Value Difference image of two registered interval exams to estimate the change in lesion volume. A linear weighting and trimming curve is used to accurately account for the contribution of partial voxels. This technique is insensitive to slight misregistration and useful in analyzing simple lesions with uniform contrast or lesions with insufficient mutual information to allow the computation of an accurate warp. The methods are tested on both synthetic and in vivo liver lesions and results are evaluated against estimates obtained through careful manual segmentation of the lesions. Our findings so far have given us reason to believe that the estimators are reliable. Further experiments on numerous in vivo lesions will probably establish the improved efficacy of these methods in supporting earlier detection of new disease or conversion from stable to progressive disease in comparison to existing clinical estimation techniques.
Expression of rat hepatic glucokinase in Escherichia coli.

Summary Rat Liver glucokinase was expressed in Escherichia coli by using an expression system based on bacteriophage T7 RNA polymerase. The expressed protein starts with the predicted initiator methionine residue and ends at the appropriate carboxyl terminal residue. It was partially purified by ammonium sulfate precipitation and gel filtration and had kinetic and physical properties similar to the purified rat liver enzyme. The efficient expression of this low abundance hepatic protein in bacteria provides a system for in vitro analysis of mutations of the enzyme.
The Type A Behavior Pattern and Attributions for Success and Failure

This study examined the relationship between the Type A behavior pattern, as defined by both the Structured Interview and the Jenkins Activity Survey, to attributions for success and failure on a challenging performance task. Results revealed that JAS-defined Type A's and Type B's did not differ in their attributions for success, but Type A's made more internal attributions for failure than did Type Bs. This attributional difference was due to the Type A's tendency to attribute failure to a lack of ability. SI-defined Type A had no effect on attributions. These results are discussed in terms of the importance of failure for the JA S-defined Type A. Differences between various operational definitions of Type A and their relevance for coronary heart disease are also discussed.
Removal of triclosan in nitrifying activated sludge: effects of ammonia amendment and bioaugmentation.

Abstract This study investigated two possible strategies, increasing ammonia oxidation activity and bioaugmenting with triclosan-degrader Sphingopyxis strain KCY1, to enhance triclosan removal in nitrifying activated sludge (NAS). Triclosan (2 mg L−1) was removed within 96-h in NAS bioreactors amended with 5, 25 and 75 mg L−1 of ammonium (NH4–N). The fastest triclosan removal was observed in 25 mg NH4–N L−1 amended-bioreactors where high ammonia oxidation occurred. Inhibition of ammonia oxidation and slower triclosan removal were observed in 75 mg NH4–N L−1 amended-bioreactors. Triclosan removal was correlated to the molar ratio of the amount of nitrate produced to the amount of ammonium removed. Bioaugmentation with strain KCY1 did not enhance triclosan removal in the bioreactors with active ammonia oxidation. Approximately 36–42% and 59% of triclosan added were removed within 24-h by ammonia-oxidizing bacteria and unknown triclosan-degrading heterotrophs, respectively. The results suggested that increasing ammonia oxidation activity can be an effective strategy to enhance triclosan removal in NAS.
Pressure drop and heat transfer characteristics for air flow through spirally fluted tubes

Abstract An experimental investigation was carried out to determine the pressure drop and heat transfer characteristics for spirally fluted tubes in laminarm transitional and turbulent flow of air. In the laminar, transitional and turbulent regimes, the friction factor for the spirally fluted tube is generally higher than that for a smooth tube. The experimentally determined Nusselt numbers are generally higher than the smooth tube values.
Analysis of AAV serotypes 1-9 mediated gene expression and tropism in mice after systemic injection.

This study examines transgene expression and biodistribution of adeno-associated virus (AAV) pseudotyped 1–9 after tail vein (TV) injection in male mice. Using a cytomegalovirus (CMV)-luciferase transgene, the time-course of expression in each animal was tracked throughout the experiment. The animals were imaged at 7, 14, 29, 56, and 100 days after the TV injection. The total number of photons emitted from each animal was recorded, allowing examination of expression level and kinetics for each pseudotyped virus. The bioluminescence imaging revealed three expression levels (i) low-expression group, AAV2, 3, 4, and 5; (ii) moderate-expression group, AAV1, 6, and 8; and (iii) high-expression group, AAV7 and 9. In addition, imaging revealed two classes of kinetics (i) rapid-onset, for AAV1, 6, 7, 8, and 9; and (ii) slow-onset, for AAV2, 3, 4, and 5. We next evaluated protein expression and viral genome copy numbers in dissected tissues. AAV9 had the best viral genome distribution and highest protein levels. The AAV7 protein and genome copy numbers were comparable to those of AAV9 in the liver. Most surprisingly, AAV4 showed the greatest number of genome copies in lung and kidney, and a high copy number in the heart. AAV6 expression was observed in the heart, liver, and skeletal muscle, and the genome distribution corroborated these observations.
Soil thermal properties and heat transfer processes near Ny-Alesund, northwestern Spitsbergen, Svalbard

The annually thawing active layer of permafrost is central to considerations of climate change consequences in arctic areas and interpretations of deep permafrost temperatures that constitute and exceptional archive of past climate change. Moreover, a sound understanding of the thermal regime of the active layer is of great interest, because all chemical, biological and physical processes are concentrated there. The author studied this layer by examining the soil physical properties and heat transfer processes that dictate soil temperatures for an arctic desert site in northwestern Spitsbergen. A wide array of soil physical properties based on field observations and laboratory measurements were defined. These include mineralogy, grain size distribution, local regolith thickness, porosity, density, typical soil moisture profile, heat capacity and thermal conductivity. Heat transfer processes were studied through modeling of soil temperatures. The heat transfer model accounted for much of the observed soil thermal regime. It was found that thermal conduction, phase change of soil water at 0°C, and changes in unfrozen water content are the primary thermal processes that explain the observed soil temperatures in this field site. Melt-water infiltration, which is often overlooked in the energy budget, causes abrupt warming events and delivers considerable energy to the soil in late spring. An increase in frequency or magnitude of infiltration events could mimic simple spring time surface warming. Advection of ground water and soil internal evaporation were found to be generally unimportant at the site studied.
The utility of 1-[18F]fluoro-3-iodopropane for the synthesis of certain dopamine D-1 and benzodiazepine receptor radioligands

Abstract No-carrier-added (NCA) R(+)-7-chloro-8-hydroxy-3-(3′-[ 18 F]fluoropropyl)-1-phenyl-2,3,4,5-tetrahydro-3-benzazepine ( 2b ) (an analog of dopamine D-1 receptor ligand SCH 23390), ethyl 8-fluoro-5,6-dihydro-5-(3′-fluoropropyl)-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylate ( 4b ) and 3′-[ 18 F]fluoropropyl 8-fluoro-5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylate ( 6b ) (analogs of the benzodiazepine RO 15-1788) were synthesized by alkylation of the corresponding nor-compound with NCA 1-[ 18 F]fluoro-3-iodopropane in 10–15% yield (EOB) in ~110min and with a mass of 2–3nmol. Compound 2 is less potent (~ 12–14 times) than SCH 23390 in binding to rat striatal membranes in vitro . Compounds 2b, 4b and 6b exhibit no specific anatomical distribution to mouse brain. These results suggest that the substituent at position 3 of SCH 23390, and position 5 and carboxylate group of RO 15-1788 are critical determinants both of affinity and selectivity for receptor binding, and underscores the evaluation necessary when even minor changes (C1 to C3) are made in bioactive compounds.
The potential role of cardiac resynchronization therapy in acute heart failure syndromes

Cardiac resynchronization therapy (CRT) has been demonstrated to improve mortality and morbidity in patients with chronic, stable heart failure who have reduced left ventricular ejection fraction and prolonged QRS duration. Patients with acute heart failure syndromes (AHFS) have been excluded from major CRT trials. The potential benefits and risks of implementation of these devices in the AHFS setting are largely unknown. In this review, we discuss the role that early implementation of CRT may have in improving postdischarge outcomes. In addition, we also discuss the potential adverse consequences of inserting these devices in patients who are in the tenuous clinical state of AHFS.
Using smart devices to provide distributed reactive power support

Smart devices are becoming more common. Many of them already possess the hardware and software capabilities to implement the reactive power injection control as discussed in this paper. In the near future, such devices would be dispersed over a large portion of the electric distribution network, thus making distributed reactive voltage support feasible. This paper presents network-level benefits of such a scheme using a PowerWorld simulation. Applications are discussed, a proposed control framework is simulated in Simulink for a single smart device and future work is outlined.
A new look at yield of integrated circuits

Expressions are derived for integrated-circuit yield as a function of active circuit area, using as a model random distributions of indistinguishable spot defects. Previous attempts to calculate integrated-circuit yield have used a nonrandom distribution of distinguishable spot defects as their model.
Mediators and vascular effects in response toendotoxin

Recent experimental findings indicate that endotoxin (i.e. lipopolysaccharide) interacts with specific membrane receptors localized to mononuclear phagocytic cells and neutrophils. Binding of endotoxin to these cells, together with endotoxin-induced activation of host vascular endothelium, initiates a series of signal transduction events that culminate in release of numerous biochemical mediators. The latter include cytokines, platelet-activating factor, thromboxane A2, prostaglandins, leukotrienes, nitric oxide, proteases, toxic O2 radicals, and vasoactive amines. These mediators orchestrate complex biological interactions and amplification signals that lead to cardiopulmonary dysfunction and multi-organ failure within 4-6 h of experimental infusion of endotoxin into animals. The pathophysiological changes include decreased cardiac output, systemic hypotension, decreased blood flow and O2 delivery to tissues, intense pulmonary vasoconstriction and hypertension, bronchoconstriction, increased permeability, pulmonary oedema, ventilation-to-perfusion inequalities, hypoxaemia, and haemoconcentration. Metabolic alterations include increased blood lactate and pyruvate, metabolic acidosis, hyperkalaemia and hypoglycaemia. Potential therapeutic modalities for treatment of endotoxaemia/septic shock include specific antagonists directed against lipopolysaccharide, cytokine, and platelet-activating factor receptors, monoclonal antibodies directed against cytokines and lipid A/core polysaccharides of endotoxin, antiproteases, and agents that block release of toxic O2 and arachidonic acid metabolites.
Environmental Risk, Biological Risk, and Developmental Outcome.

The impact of 2 environmental and 2 biological risk measures was studied in 175 preterm children. Levels of family risk, which included family composition, support, and interaction variables, and social class, as well as increases or decreases in family risk over the 1st year of life, were examined with intraventricular hemorrhage (IVH) and other neonatal medical complications as predictors of cognitive and motor outcomes in the 2nd year of life. Family risk, early medical risk, and the Family Risk × IVH interaction emerged as significant predictors of later development. Family risk had less impact on subjects at highest medical risk. Different regression equations for each outcome underscored the specificity of environmental effects on developmental outcomes
Interactions between the egg and larval parasitoids of a gall‐forming midge and their impact on the host

Summary 1. The gall-forming midge Rhopalomyia californica was exposed experimentally to parasitism and predation during only the egg stage, during only the larval stage, during neither stage, or during both stages. 2. The combined action of natural enemies that attack during both the egg stage and the larval stage led to the lowest number of midges and total insects (midges + parasitoids) in the next generation, and the highest percentage parasitism. 3. The larval parasitoid killed a large fraction of hosts without producing new parasitoid offspring, while there is some indication that the egg parasitoid on its own tended to produce the most parasitoid offspring. The contrasting implications of host mortality versus parasitoid production for biological control are discussed. 4. Exposure to larval parasitoids resulted in a reduction in the number of egg parasitoid offspring produced, but exposure to the egg parasitoid did not affect the number of larval parasitoid offspring produced significantly.
Effects of Functional Mobility Skills Training for Young Students with Physical Disabilities

The Mobility Opportunities Via Education (MOVE®) Curriculum is a functional mobility curriculum for individuals with severe disabilities. This study investigated the effects of the MOVE Curriculum on the functional walking skills of five elementary-aged students with severe, multiple disabilities. The MOVE Curriculum was implemented using a multiple-baseline across subjects design. Repeated measures were taken during baseline, intervention, and maintenance phases for each participant. All students demonstrated progress in taking reciprocal steps during either intervention or maintenance. Results for each participant are discussed as well as implications and future directions for research.
Research Advances: Nanotechnology Research Attacks Cancer, Offers Big Development in Light Harvesting, and Addresses the 3Rs: Recover, Recycle, and Reuse

This installment of Research Advances describes how breakthrough research in nanotechnology affords educators a big opportunity for stimulating the minds of their students.
Chemotherapy Regimens in Advanced Non-Small-Cell Lung Cancer: Implications and Future Perspectives

Abstract The four chemotherapy regimens evaluated in Eastern Cooperative Oncology Group study 1594 (paclitaxel/cisplatin, gemcitabine/cisplatin, docetaxel/cisplatin, and paclitaxel/carboplatin) are effective treatment options for the therapy of advanced non–small-cell lung cancer (NSCLC). Only numerical differences have been noted in overall survival with these regimens, probably due to the fact that total therapy received by these patients was the same. There was an improved median time to progression with the gemcitabine/cisplatin doublet. Choice of a chemotherapy regimen in practice is being based on the tolerability and sideeffect profile of these doublets. In the foreseeable future, we will see the use of selective and individualized therapy in addition to chemotherapy in the management of advanced NSCLC.
Application of polarography for monitoring the fish postmortem metabolite transformation

Abstract Based on the principle of polarography, a new technique has been developed for monitoring the degradation of adenosine triphosphate (ATP) in fish muscles. The technique consisted of a polarographic electrode attached to a temperature-controlled reaction chamber where the metabolites in fish muscles were enzymatically degraded to uric acid and hydrogen peroxide. If the electrode was polarized at +0.7 volts with respect to a silver cathode and a platinum anode, the electrode response to uric acid and hydrogen peroxide was found to be of an additive manner. Consequently, the newly proposed technique offered a simple and rapid determination of inosine, hypoxanthine, and inosine monophosphate in fish homogenates. Excellent agreement was observed between the results obtained by the new technique and those of a new commercial freshness meter, where oxygen consumption was followed during the enzymic reactions.
The ship as laboratory: making space for field science at sea.

Expanding upon the model of vessels of exploration as scientific instruments first proposed by Richard Sorrenson, this essay examines the changing nature of the ship as scientific space on expedition vessels during the late nineteenth century. Particular attention is paid to the expedition of H.M.S. Challenger (1872–1876) as a turning point in the design of shipboard spaces that established a place for scientists at sea and gave scientific legitimacy to the new science of oceanography. There was a progressive development in research vessel design from “ship as instrument” to “ship as laboratory” and changing spatial practices aboard these vessels were paralleled by changes in shipboard culture. I suggest that the “ship as laboratory” has now in turn been supplanted by a new model, the “ship as invisible technician”, as oceanographic research vessels deploy remote-sensing equipment and gather data that are no longer analyzed on board.
Thermal Tolerance of Diploid Versus Triploid Rainbow Trout and Brook Trout Assessed by Time to Chronic Lethal Maximum

An effect of ploidy on thermal tolerance in juvenile trout was assessed in a series of tests comparing time to chronic lethal maximum (CLMax). Diploid and triploid fish were produced from a common spawn for three different groups each of brook trout Salvelinus fontinalis and of rainbow trout Oncorhynchus mykiss. One or two CLMax tests were performed per group, on between 15 and 50 individuals per ploidy within groups. The tests involved exposure of fish to a progressive 2°C day−1 water temperature increase and recording of the time at which each individual fish reached loss of equilibrium (LE). The time to LE data were rank transformed and analyzed as a randomized complete block design. Although relative performance varied among trials, the analysis indicated overall differences due to ploidy were small and nonsignificant among both brook trout and rainbow trout. Size proved to be significantly correlated with time to LE in the brook trout trials, but not in the rainbow trout trials. Two of the six groups included a large proportion of fish which had received a heat shock following fertilization, but were not successfully triploidized. In both cases, thermal tolerance of the heat-shocked diploids was similar to that of the non-heat shocked control diploids, indicating no persistent effect of the heat shock on thermal tolerance.
Transmission zeros and the two-port parameters

Abstract This paper presents relationships between the transmission zeros of an impedance and the two-port impedance parameters zij(s) (i, j = 1, 2) or the chain parameters of its Darlington equivalent. The odd and even properties of the two-port parameters are investigated. It is shown that z12(s) and z21(s) of a lossless two-port network need not be odd functions. A general relationship between the complex-normalized scattering matrix of a two-port network with complex load impedances and the unit-normalized scattering matrix of its augmented two-port network, when the complex load impedances are represented by their Darlington equivalents, is given.
Quantitative MR relaxometry study of muscle composition and function in duchenne muscular dystrophy

Magnetic resonance imaging and maps of T1 and T2 values were used to study muscle composition in Duchenne muscular dystrophy (DMD). The mean T2 of anterior tibial muscle was 27 msec in healthy control subjects and 43 msec with increased fatty infiltration in DMD patients. In stronger DMD patients, the distribution of muscle T2 values was narrow, centered at 27 msec as in the controls, with a nonoverlapping fat peak centered at 49 msec. In weaker DMD patients, the width of the muscle T2 peak increased and the peak shifted toward the fat peak. Mean muscle T1 decreased from 1.7 to 0.6 second with increasing fatty infiltration. These results show that quantitative T1 and T2 maps may be used to assess muscle status and monitor DMD progression.
And what of human musicality

This target article presents a plausible evolutionary scenario for the emergence of the neural preconditions for language in the hominid lineage. In pleistocene primate lineages there was a paired evolutionary expansion of frontal and parietal neocortex (through certain well-documented adaptive changes associated with manipulative behaviors) resulting, in ancestral hominids, in an incipient Broca's region and in a configurationally unique junction of the parietal, occipital, and temporal lobes of the brain (the POT). In our view, the development of the POT in our ancestors resulted in the neuroanatomical substrate consistent with the ability for representations in modality-neutral association cortex and, as a result of structure-imposing interaction with Broca's area, the hierarchically structured conceptual structure. Evidence from paleoneurology and comparative primate neuroanatomy is used to argue that Homo habilis (2.5-2 million years ago) was the first hominid to have the appropriate gross neuroanatomical configuration to support conceptual structure. We thus suggest that the neural preconditions for language are met in H. habilis. Finally, we advocate a theory of language acquisition that uses conceptual structure as input to the learning procedures, thus bridging the gap between it and language.
Recent Results concerning Interplanetary Plasma

The MIT plasma probe, installed aboard the first IMP, has shown that the space around the earth is sharply divided into three regions. At large distances from the earth, we find a region (region 1) occupied by a plasma moving with a velocity from about 300 to 400 km/sec, in a direction nearly radial away from the sun; its thermal energy density is small compared with its kinetic energy density of bulk motion. Presumably we see in this region the "solar wind," unperturbed by the presence of the earth. As we approach the earth, we pass from region 1 to region 2 where the velocity of the plasma is often below the limit of detectability and in any case much smaller than in region 1. The thermal energy density is large, corresponding to temperatures of the order of millions of degrees, but a rigorous definition of the temperature is impossible because the velocity distribution does not appear to be Maxwellian. Approaching the earth further, we meet a second boundary, separating region 2 from region 3, where the plasma probe does not detect any plasma. Both boundaries have a characteristic comet-like shape, with a blunt nose facing the sun and a long diverging tail in the opposite direction. Presumably the boundary between regions 1 and 2 represents a shock front, across which the plasma flow changes from supersonic to subsonic.
A Novel Technique for Distal Shunt Revision: Retrospective Analysis of Guidewire-Assisted Distal Catheter Replacement.

Background Ventriculoperitoneal shunt revision is a common procedure. Disconnection and fracture of the distal catheter remain a common cause of ventriculoperitoneal shunt malfunction. Objective To describe a novel procedure for peritoneal replacement of the distal catheter by using a guidewire and a modified Seldinger technique (guidewire-assisted distal catheter replacement) and retrospectively evaluate the results of the surgical procedure. Methods Between September 2005 and December 2013, 68 patients were treated by a single surgeon (DMW) with distal catheter replacement using our technique. In brief, the previously placed distal catheter was exposed at its entry site into the abdomen. A soft guidewire with hydrophilic coating was inserted down the distal catheter into the peritoneum. The distal catheter was then removed over the guidewire, leaving the guidewire in place. A peel-away sheath and dilator were then inserted over the guidewire, and the dilator and guidewire were removed. The new distal catheter was then passed from the valve to the abdomen and was then fed through the peel-away sheath into the peritoneum. Charts were retrospectively reviewed for preoperative presentation, operative technique, and postoperative outcome. Records were specifically examined for any early or late complications. Results The mean patient age at surgery was 13 years. No immediate acute complications were noted. Of the 68 total patients, 45 patients had more than 6 months of follow-up. Of the 68 patients, 7 patients required another distal revision after guidewire-assisted distal catheter replacement. Conclusion Distal shunt malfunction due to a mechanical failure is a common reason for shunt revision. We describe a technique for guidewire-assisted distal catheter replacement.
Culture characteristics of cells derived from type II pneumocyte enriched fractions from rabbit and rat

Type II cell enriched fractions were isolated from rabbit and rat lungs using density gradient centrifugation. Cultures established from these fractions contained predominantly cells similar in most morphological respects to type II pneumocytes. These were in continuous replicating culture for 1 year and still exhibited contact inhibition. Membrane-bound structures reminiscent of, but no longer strictly identical to, type II cell lamellar cytosomes were seen in cells from these long-term cultures although their numbers were reduced in comparison to lamellar bodies in freshly isolated cells. Mitochondrial numbers and sizes, determined morphometrically, were reduced after culture in comparison to freshly isolated type II cells and those in situ. Phosphatidylcholine was synthesized by these cells and released into the extracellular medium. Application of laser activated electronic sizing data, confirmed by direct micrometry, demonstrated a significant increase in cell size as a function of culture. This sizing data, after prior confirmation by electron microscopy, was used as an aid in identifying type II cells and macrophages in dispersion, especially with those cells derived from rabbit lungs.
Diagnosing the bladder as the source of pelvic pain: successful treatment for adults and children

SUMMARY The key to successful therapy of interstitial cystitis (IC) is to correctly diagnose it. The significant majority of patients with IC have a dysfunctional bladder epithelium that allows urinary solutes (primarily potassium) to leak into the bladder wall, causing symptoms and tissue damage. Drugs that correct this dysfunction and suppress symptoms are important to achieve successful outcomes in patients. Today over 95% of females with IC are misdiagnosed as having gynecologic chronic pelvic pain, vulvodynia, vaginitis, endometriosis, overactive bladder or urinary tract infection. Men are misdiagnosed as having prostatitis. Often children are not diagnosed at all. Multimodal drug therapy may be required and can achieve successful resolution of IC in over 90% of patients. IC in children can be treated successfully with pentosan polysulfate.
Crystallographic coincidence of two bridging species in a dinuclear CoIII ethynyl­benzene complex

In the title compound, trans,trans-[μ-(m-phenyl­ene)bis­(ethyne-1,2-di­yl)]bis­[chlorido(1,4,8,11-tetra­aza­cyclo­tetra­deca­ne)cobalt(III)]–trans,trans-[μ-(5-bromo-m-phenyl­ene)bis­(ethyne-1,2-di­yl)]bis­[chlorido(1,4,8,11-tetra­aza­cyclo­tetra­deca­ne)cobalt(III)]–tetra­phenyl­borate–acetone (0.88/0.12/2/4), [Co2(C12H4)Cl2(C10H24N4)2]0.88[Co2(C10H3Br)Cl2(C10H24N4)2]0.12(C24H20B)2·4C3H6O, with the exception of the acetyl­ene and bromine groups, all atomic postitions are the same in the two compounds and are modeled at full occupancy. The CoIII ions are six-coordinate with acetyl­ide and chloride ligands bound to the axial sites and the N atoms from the cyclam rings coordinated at the equatorial positions. N—H⋯O and N—H⋯Cl hydrogen-bonding interactions help to consolidate the crystal packing.
Inhibition by wheat bran cereals of the development of aberrant crypt foci and colon tumours

Abstract As variation in both type of fibre and its physical properties can influence physiological effects, the efects of different dietary levels (1, 4, 8%, w/w) of unprocessed wheat bran (WB) were compared with those of two of its processed commercial formulations used in breakfast cereals, on the formation of aberrant crypt foci (ACF) and colon tumours in Fischer 344 rats following azoxymethane (AOM) administration. All diets were high in fat (20 g/100 g) and low in calcium (0.2%, w/w). The rats were fed the experimental diets for 2 wk before receiving two sc injections of AOM (15 mg/kg body weight/wk). 8 wk following the first injection of AOM, five rats per group were killed and the formation of ACF was measured. 23 wk following the first injection of AOM, 12 rats per group were killed and the colon tumour incidence in different dietary groups was measured. The results showed that increasing the dietary concentration of fibre from 1 to 8% (w/w), using all the wheat bran formulations, significantly reduced the number of ACF per rat. None of the diets showed any significant effect on the normal growth of rats. No statistically significant differences were observed between the protective properties of WB and the two commercial formulations under investigation in terms of the reduction of the number of ACF, or in terms of the reduction of the colon adenocarcinoma incidence. The results suggest that wheat bran and its two commercial formulations can offer protection against colon cancer even when they are consumed with a high-fat/low-calcium diet. The addition of any of these formulations of wheat bran fibre is likely to be equally effective in the prevention of colon cancer in human populations that habitually consume high-fat/low-fibre Western-style diets.
Penile plethysmography on impotent men using vacuum constrictor devices

Vacuum constrictor devices achieve an erection-like state of the penis by means of a clear plastic cylinder, a vacuum pump, and a constrictor ring. Although these devices are noninvasive compared with penile injections and implants, they have been used less often in clinical practice. Part of the hesitancy to prescribe these devices has been related to the lack of published data concerning the effects of constriction on penile blood flow. In this report, we utilized penile plethysmography to estimate penile blood flow on 51 men before, during, and after the use of the constrictor ring. All patients demonstrated a 70-75 percent decline in the amplitude of the pulse-volume curve during constriction, but continuous blood flow was maintained in each case. Within sixty seconds after removal of the ring, the amplitude returned to baseline values for all men, including 12 patients with a penile brachial index of less than 0.7. Among 33 patients, there was evidence of a transient increase of amplitude following constriction, which was consistent with a postischemic hyperemia. These findings suggest normal penile blood flow, and indicate that the use of constrictor rings may be safe for patients with these tracings. Penile plethysmography appears to be a useful technique to help with patient selection and constrictor ring fit. Follow-up tracings probably should be scheduled at periodic intervals for men utilizing these rings and devices.
Perioperative management of patients with poorly functioning ventricles in the setting of the functionally univentricular heart.

The patient with a functionally univentricular heart is at increased risk for ventricular dysfunction for a variety of reasons. At birth, the pulmonary and systemic circulations are in parallel, leading to pulmonary overcirculation and a volume-loaded functional ventricle. Significant atrioventricular valvar regurgitation, abnormal ventriculoarterial coupling, diastolic dysfunction, and altered ventricular geometry can also contribute to long-term ventricular dysfunction. These collected circumstances place the patient at increased risk for perioperative morbidity and mortality. We will discuss in this review the pathophysiology that leads to ventricular dysfunction at each stage of surgical palliation, as well as the strategies for perioperative management. In addition, we will highlight novel strategies for management of ventricular dysfunction.
Illusory conjunctions in simultanagnosia: Coarse coding of visual feature location?

Simultanagnosia is a disorder characterized by an inability to see more than one object at a time. We report a simultanagnosic patient (ED) with bilateral posterior infarctions who produced frequent illusory conjunctions on tasks involving form and surface features (e.g., a red T) and form alone. ED also produced "blend" errors in which features of one familiar perceptual unit appeared to migrate to another familiar perceptual unit (e.g., "RO" read as "PQ"). ED often misread scrambled letter strings as a familiar word (e.g., "hmoe" read as "home"). Finally, ED's success in reporting two letters in an array was inversely related to the distance between the letters. These findings are consistent with the hypothesis that ED's illusory reflect coarse coding of visual feature location that is ameliorated in part by top-down information from object and word recognition systems; the findings are also consistent, however, with Treisman's Feature Integration Theory. Finally, the data provide additional support for the claim that the dorsal parieto-occipital cortex is implicated in the binding of visual feature information.
Er3+ Electronic Energy Levels in GaN

The 4f11 4I13/2 → 4I15/2 emission of Er3+ at 1.54 μm, particularly in a GaN host crystal, has been of interest in optical communications for some time because of its transmission efficiency and temperature stability. Theoretical treatments of this transition are complicated by the large number of open-shell electrons, moderate relativistic effects, and splittings due to the crystalline field. We have modeled the system as a cluster of ions centered on an Er3+ ion and have used spin−orbit configuration interaction to study the electronic states involved. It is an unusual quantum theory problem in that single-excitation terms in the wave functions are of central importance.
Strain-rate estimates for crevasse formation at an alpine ice divide: Mount Hunter, Alaska

Crevasse initiation is linked to strain rates that range over three orders of magnitude (0.001 and 0.163 a -1 ) as a result of the temperature-dependent nonlinear rheological properties of ice and from water and debris inclusions. Here we discuss a small cold glacier that contains buried crevasses at and near an ice divide. Surface-conformable stratigraphy, the glacier's small size, and cold temperatures argue for limited rheological variability at this site. Surface ice-flow velocities of (1.2-15.5) � 0.472 m a -1 imply classic saddle flow surrounding the ice divide. Numerical models that incorporate field-observed boundary conditions suggest extensional strain rates of 0.003-0.015 a -1 , which fall within the published estimates required for crevasse initiation. The occurrence of one crevasse beginning at 50 m depth that appears to penetrate close to the bed suggests that it formed at depth. Field data and numerical models indicate that a higher interior stress at this crevasse location may be associated with steep convex bed topography; however, the dynamics that caused its formation are not entirely clear.
Separate neural substrates of the locomotor-activating properties of amphetamine, heroin, caffeine and Corticotropin Releasing Factor (CRF) in the rat

Abstract Destruction of dopamine terminals within the nucleus accumbens (N.Acc.) with 6-hydroxydopamine blocked the locomotor activating properties of d-amphetamine, but not caffeine or corticotropin-releasing factor (CRF). Infusion of muscimol into the region of nucleus accumbens efferent terminals in the substantia innominata and lateral preotic region (SI/LPO) blocked amphetamine-, but not caffeine- or CRF-stimulated locomotion. These muscimol infusions also blocked heroin-stimulated locomotion. These results suggest that amphetamine, acting through a process dependent on N.Acc. dopamine transmission, stimulates locomotion by decreasing GABAergic activity within this N.Acc.-SI/LPO projection; heroin, known to act through a process dependent on N.Acc. opiate receptor activation, also stimulates locomotion by decreasing GABAergic activity within the SI/LPO; caffeine and CRF produce their activation through different neural substrates.
Separation thresholds for bar targets presented with color contrast only

Separation threshold scores for rectangular bar targets with combination of red, yellow, green and blue targets and grounds were obtained. Threshold scores were low, with small differences between scores obtained with the different color combinations.