cssi/SciSciGPT-SciSciNet huggingface dataset:
Concepts of oxygen transport at the microcirculatory level

This article compares and contrasts the classic paradigms underlying the development of chronic and acute hypoxia in tumors. The classic theory of Thomlinson and Gray suggested that chronic hypoxia is the result of large intravascular distances. Newer evidence suggests that a multiplicity of effects contribute to this process, including steep longitudinal gradients of partial pressure of oxygen (Po 2 ) along the vascular tree before arteriolar entry into tumor, rheologic effects on red cell deformability brought on by intravascular hypoxia, uneven distribution of red cell fluxes in microvessels leading to plasma channels, irregular vascular geometry, and oxygen demand that is out of balance with the supply. The most common theories have suggested that vascular statsis is the most common source of acute hypoxia. If this were true, the incidence of this form of hypoxia would be relatively rare because most studies indicate that total stasis probably occurs less than 5% of the time. Studies have suggested, however, that spontaneous fluctuation in tumor blood flow, on the microregional level, can lead to tissue hypoxia, and total vascular stasis is not required. Spontaneous fluctuations in flow and Po 2 appear to occur commonly. Thus, the most current evidence suggests that tumor oxygenation is in a continuous state of flux. Collectively, this new information has important implications for therapy resistance and gene expression.
Effects of serotonin and serotonin analogs on posture and agonistic behavior in crayfish

Exogenous serotonin has been shown to induce an elevated, flexed posture in crustaceans and has also been hypothesized to enhance aggressive behavior. We conducted three experiments to further investigate the effects of serotonin and serotonin analogs on posture and agonistic behavior in the crayfish Procambarus clarkii. In the first experiment, we recorded behavioral responses to five different concentrations of serotonin injected into the ventral hemolymph sinus. The amine elicited a series of behaviors including the characteristic high, flexed posture, but none were clearly associated with aggression. In our second experiment, we tested serotonin and four serotonin receptor agonists [1-(3-chlorophenyl)piperazine dihydrochloride, 2-methyl-5-hydroxytryptamine maleate, 5-carboxamidotryptamine maleate and α-methyl-5-hydroxytryptamine maleate] and measured the ability of each agonist to mimic the actions of the amine. High concentrations of 1-(3-chlorophenyl)piperazine dihydrochloride most closely mimicked the actions of serotonin; 5-carboxamidotryptamine maleate induced a high stance, but did not otherwise induce effects similar to serotonin. In our third experiment, we conducted an analysis of fighting behavior between pairs of crayfish that had received injections of control saline, serotonin, or 5-carboxamidotryptamine maleate. Serotonin generally reduced the level of aggression between opponents, whereas 5-carboxamidotryptamine maleate enhanced the performance of several agonistic behaviors.
Stress measurements in drifting pack ice

Abstract Accurate measurements of in-situ pack ice forces are necessary to improve ice forecasting models and to estimate loads on offshore structures. Two months of in-situ ice stress measurements were obtained in the pack ice of the eastern Arctic during the fall of 1988. Sensors were placed to examine both the horizontal and vertical distributions of ice stresses in multiyear ice. Stresses in the multiyear ice 200 m from the edge of the floe reached 150 kPa during extreme deformation events. Within a few meters of the edge and in adjacent first-year ice, they exceeded 350 kPa on several occasions (400 kPa in one instance) during local ice failure events. Thermally induced stresses at shallow depths in the multiyear ice were caused by rapid temperature changes and could be nearly as large as stresses observed during deformation. The vertical distribution of stresses varied with the type of deformation event, but the largest values were always observed in the upper half of the ice sheet. Stresses due to deformation were rapidly attenuated away from the edge of the floe. Near the edge, however, recorded stresses agreed well with those observed in the adjacent first-year ice. These two locations also experienced twice daily oscillations of about 50 kPa which are apparently tidal or inertially induced.
The Human Genome and Public Policy: A Nursing Perspective

The Human Genome Project has completed a rough draft of the sequence that comprises human DNA. For the first time, the scientific discoveries have been conducted in tandem with research exploring the social, legal, and ethical implications of the research. Several committees have studied the policy implications of the genetics information explosion. The Secretary's Advisory Committee on Genetic Testing's report was received by the Secretary of the U.S. Department of Health and Human Services in November 2000 and contains recommendations for the oversight of genetic testing. Public policy issues that affect nursing practice in the area of genetics must be explored by individual nurses and professional nursing organizations.
Disruptive Behavior in Young Children: What Does It Mean?

ABSTRACT Objective To examine how the Diagnostic Classification of Mental Health and Developmental Disorders of Infancy and Early Childhood (DC 0–3) primary diagnoses, Parent–Infant Relationship Global Assessment Scale, and Child Behavior Checklist/2–3 (CBCL/2–3) externalizing and internalizing symptoms augment the DSM-III-R/IV and guide treatment. Method 82 children aged 18 to 47 months, who presented with disruptive behavior to an early childhood psychiatry clinic, were diagnosed using DSM-III-R/IV, DC 0–3, and the CBCL/2–3. Results Children with DSM-III-R/IV disruptive disorders or attention-deficit/hyperactivity disorder were diagnosed with DC 0–3 regulatory disorders, disorders of affect, and traumatic stress disorder. Clinically significant externalizing and internalizing symptoms co-presented in 45.1% of the children. Of children with disorders of affect, 41.2% had relationships categorized as disordered, contrasting with 21.1% of those with traumatic stress disorder and 10.3% of those with regulatory disorders. Increasingly disordered relationships were significantly correlated with externalizing and internalizing symptoms, and children with disordered relationships were 3.6 times more likely to have clinically significant levels of internalizing symptoms. Conclusion In these children with disruptive behaviors, co-presentation of externalizing and internalizing symptoms is most common. Those with increased relational risk had more externalizing and internalizing symptoms and more disorders of affect.
SIBLING EFFECTS ON SUBSTANCE USE AND DELINQUENCY

Sibling effects refer to the immediate influence one sibling may have on another or to indirect influences through their embeddedness in a common friendship network We used three aspects of sibling mutual interaction—warmth, conflict, and frequency of contact with mutual friends—to evaluate sibling effects on delinquency and substance use in 135 brother pairs, 142 sister pairs, and 141 mixed-sex pairs in the Arizona Sibling Study (primarily aged 10–16 years). We hypothesized that sibling relationship variables would condition the behavioral resemblance of the younger and older sibling. For both substance use and delinquency, this prediction was confirmed for warmth and mutual friends: Sibling pairs who reported warmer mutual relationships or greater contact with mutual friends were more alike behaviorally. The statistical sibling effects were not explained by social class, parental substance use, or rearing styles. We interpret them as the influence of one sibling on the other and as the influence arising from sharing common friends. Given the existence of sibling effects, the strength of shared familial influences of other origins must be revised downward.
CF carrier testing in a high risk population: anxiety, risk perceptions, and reproductive plans of carrier by "non-carrier" couples.

Purpose: The risk perceptions, psychological status and reproductive plans of 52 carrier by “noncarrier” (mutation screen negative) couples is the subject of this report. Methods: Cystic fibrosis (CF) carrier testing was offered to relatives of individuals with CF. Results: In this population testing was not associated with any significant adverse psychological effects, reproductive uncertainty, or inaccurate risk perceptions. Conclusions: The results of this study have important implications in light of the recent NIH CF Consensus Panel recommendations that CF carrier testing be offered to all high risk adults and all couples planning a pregnancy or seeking prenatal testing.
The Relaxation of Stress in Wool Fibers

A study of the decay of tension of Columbia 56's wool fibers maintained at constant tem perature and extension has been carried out in water, in solutions of sodium bisulfite of various concentrations, and in neutral salt solutions.The experimental results obtained in water are similar although not identical to the results previously found by Speakman and Shah for human hair. The rapid stress decay of stretched wool which occurs when sodium bisulfite is added appears to be due to a chemical reaction involving the cystine linkages. The rate becomes independent of bisulfite concentration at sufficiently high concentrations. A much slower but unexpectedly large stress decay occurs in the presence of neutral salts such as sodium chloride.
Recipe for making a thin film detector

Abstract The thin film detector consists of a thin scintillator film placed perpendicular to the parallel faces of two opposing photo-multiplier tubes and uniquely is capable of responding to the differential energy loss of transiting heavy mass ions (e.g., fission fragments). A step-by-step procedure for fabricating a thin film detector is presented. Testing routines are described and typical results are shown for comparing the relative performance of the finished product with regard to light and heavy ion energy loss response.
Treatment of scaphoid nonunion with casting and pulsed electromagnetic fields: A study continuation

This article presents a continuation of a study of the treatment of scaphoid nonunion with pulsed electromagnetic fields (PEMF) and cast immobilization. Fifty-four patients were reviewed. The overall success rate for healing has decreased since the previous review from 80% to 69%. Proximal pole fractures healed in 50%. Success in nonunions with associated radiographic evidence of avascular necrosis decreased from 89% to 73%. Although we believe that the indications for use of PEMF have not changed significantly, this study suggests that a successful outcome with PEMF and casting is less likely than previously reported. We believe that until additional clinical studies have further defined the indications, treatment protocol, and efficacy of this method PEMF treatment should be a secondary alternative to bone-grafting procedures.
Achieving Sustainability in World Bank Energy Efficiency Projects: Lessons Learned Developing ESCOs in China

ABSTRACT This article considers why some energy efficiency investment projects in developing countries may yield more sustainable results than others. The author concludes that systematic attention to institutional development is of prime importance. The story behind successful development of energy service companies (ESCOs) in China with World Bank support is cited as an illustrative example. Annual energy performance contracting investment by China's ESCOs topped USD 1 billion in 2007 and continues to grow.
Synthesis and molecular structures of nitrosoarene metalloporphyrin complexes of ruthenium.

Several new ruthenium porphyrins containing nitrosoarene ligands have been synthesized and characterized by IR and 1H NMR spectroscopy, and by single-crystal X-ray crystallography. Bis-nitrosoarene complexes of the form (por)Ru(ArNO)2 (Ar = aryl group; por = TPP, TTP; TPP = tetraphenylporphyrinato dianion, TTP = tetratolylporphyrinato dianion) were prepared in good yields from the reaction of the nitrosoarenes with (por)Ru(CO). The IR spectra of the complexes (as KBr pellets) display new bands in the 1346–1350 cm−1 region due to νNO. Reactions of the (por)Ru(ArNO)2 complexes with excess pyridine and 1-methylimidazole produce the mono-nitrosoarene complexes (por)Ru(ArNO)(py) and (por)Ru(ArNO)(1-MeIm), respectively. The IR spectra of these mono-nitrosoarene complexes reveal a lowering of νNO by 14–44 cm−1, a feature consistent with the replacement of one of the π-acid ArNO ligands with the more basic pyridine and 1-MeIm ligands. The solid-state molecular structures of two members of each of the three classes of compounds, namely (por)Ru(ArNO)2, (por)Ru(ArNO)(py) and (por)Ru(ArNO)(1-MeIm) were determined by single-crystal X-ray diffraction, and reveal the N-binding mode of the ArNO ligands.
The poverty of culture: notes toward a theory

This article seeks to demythologize the culture of poverty as theorized and practiced by social scientists, policy-makers and social welfare/work practitioners during the past five decades. Poverty is a product of systemic inequalities sustained by a predatory culture. As argued, it is poverty of culture that retards progress even in the advanced states of social development.
Tú velas por los tuyos: Weak Labor Markets and the Importance of Social Networks

Literature on the economic incorporation of immigrants to new destinations has been missing a discussion on how the strength of the local economy affects immigrants’ need for social networks and how it might also affect the relative importance of strong versus weak ties for immigrant job seekers. Through the use of in-depth interviews, the role and importance of social networks in the labor market incorporation of Hispanic immigrants in economically weak cities is examined, as well as the consequences to those immigrants who are unable to command or lack access to social networks and/or ethnic resources. This paper contextualizes the importance of strong ties for immigrants in economically weak new destinations and argues that in places with such a constricted labor market and stagnant economies, it is imperative for recent arrivals to access and/or construct these strong ties in order to more effectively gain entry into the host society’s labor market.
Ejection of atoms from rare-gas solids by low energy cascades

Abstract The results of a molecular dynamics calculation are presented for collisional ejection of atoms from excited low temperature rare-gas solids. An atom in the solid is assumed to receive an amount of kinetic energy consistent with an energetic, non-radiative decay of an excited dimer and the number, energy and direction of ejected atoms are calculated as functions of depth in the solid of the initially energized atom. The results are compared to the standard binary-collision cascade model and to a thermal-spike model for ejection. The yields integrated over depth are found to depend nearly linearly on energy deposition as in the collision cascade model. They also scale with the surface number density and the surface binding energy. The calculated angular and energy distributions are relatively insensitive to the exciting energies and exhibit distinct differences from the cascade and thermal models. However, the peak position in the energy spectra is consistent with the cascade model if the surface binding energy, which is about two thirds the cohesive energy for these solids, is used. Experimental results on the electronic sputtering of solid argon are briefly considered.
Dramatic increase in late Cenozoic alpine erosion rates recorded by cave sediment in the southern Rocky Mountains

Abstract Apparent increases in sedimentation rates during the past 5 Ma have been inferred at sites around the globe to document increased terrestrial erosion rates, but direct erosion rate records spanning this period are sparse. Modern and paleo-erosion rates for a small alpine catchment (3108 m above sea level) in the Southern Rocky Mountains are measured using the cosmogenic radionuclides (CRNs) 10Be and 26Al in cave sediment, bedrock on the overlying landscape surface, and coarse bedload in a modern fluvial drainage. The unique setting of the Marble Mountain cave system allows the inherited erosion rates to be interpreted as basin-averaged erosion rates, resulting in the first CRN-based erosion rate record from the Rocky Mountains spanning 5 Myr. Pliocene erosion rates, derived from the oldest cave sample (4.9 ± 0.4 Ma), for the landscape above the cave are 4.9 ± 1.1 m Myr− 1. Mid Pleistocene erosion rates are nearly an order of magnitude higher (33.1 ± 2.7 to 41.3 ± 3.9 m Myr− 1), and modern erosion rates are similar; due to the effects of snow shielding, these erosion rate estimates are likely higher than actual rates by 10–15%. The most likely explanation for this dramatic increase in erosion rates, which likely occurred shortly before 1.2 Ma, is an increase in the effectiveness of periglacial weathering processes at high elevations related to a cooler and wetter climate during the Pleistocene, providing support for the hypothesis that changes in late Cenozoic climate are responsible for increased continental erosion.
Constraints on the metathesis of sonorant consonants in Judeo-Spanish

Judeo-Spanish denotes those varieties of Spanish preserved by the Sephardic Jews who were expelled from Spain in 1492 and have emigrated throughout Europe, North Africa, the Middle East, and the United States. This paper examines three types of consonant metathesis in Judeo-Spanish: daldo < dadlo ‘give it’, terne ‘I will have’ < tener ‘to have’, and tadre < tarde ‘late, afternoon’. The first two types are analyzed in terms of syllable contact optimization, following Holt’s (2004) Optimality-theoretic analysis of dl and dn metathesis in Old Spanish. Heteromorphemic dm clusters were immune from metathesis in Old Spanish, and the same restriction is found in modern-day Judeo-Spanish: dadme vs. *damde/dande ‘give me’. A novel analysis is proposed in which nasal place assimilation and positional faithfulness constraints block dm metathesis across morpheme boundaries. Unlike dl and nr metathesis, transposition of rd clusters in Judeo-Spanish does not result from syllable contact optimization. This innovation is analyzed as an effect of the Obligatory Contour Principle, whereby adjacent segments identical in place, manner, and voicing specifications are prohibited. The analyses developed in this paper highlight the role of constraints on segmental features, which interact with sonority constraints to generate the attested patterns of consonant metathesis. The paper also considers additional metathesis patterns from other languages in light of the proposed analyses, as well as some of the difficulties posed by the Hispano-Romance data with respect to perceptually-based alternative approaches.
The large GTPase dynamin is required for hepatitis B virus protein secretion from hepatocytes.

Abstract Background/Aims : The hepatocellular transport pathways and cellular proteins utilized during the packaging and secretion of hepatitis B virus are poorly understood. In this study, we tested if the large GTPase dynamin, a protein involved in vesicle formation and secretion at the trans-Golgi network in hepatocytes, is also used by hepatitis B virus (HBV) in secreting viral proteins. Methods : Using HepG2.2.15 cells expressing the full-length HBV genome, we tested the effects of wild-type and mutant dynamin on the localization and secretion of two hepatitis B antigens, hepatitis B surface antigen (HBsAg) and hepatitis B e antigen (HBeAg). Distribution of these two antigens was analyzed morphologically in cells transiently transfected with wild-type or mutant dynamin constructs, whereas secretion of the antigens was measured by testing for antigen levels in the media of transfected cells. Results : Mutant dynamin was found to induce a striking redistribution of HBsAg and HBeAg to a perinuclear compartment, as well as a decrease in the levels of HBsAg and HBeAg present in cell culture media indicating a reduction in viral protein secretion. At the electron microscopy level, cells expressing the mutant dynamin showed a marked accumulation of viral particles in dilated cisternae of an uncharacterized cellular compartment. Conclusions : Intact dynamin function is required for secretion of HBV proteins from hepatocytes through an uncharacterized cellular compartment.
Novel curve fitting design methodology for carbon nanotube SRAM cell optimization

Unlike CMOS circuit design, even though there are promising advantages to use carbon nanotubes for digital circuits in terms of power, delay, temperature, and area, one of the critical issues to design by using carbon nanotubes is optimization of additional design parameters such as number of nanotubes and pitch size. To reduce the optimization complexity of the increased technology parameters, in this paper, we proposed a novel curve fitting design methodology for carbon-nanotube circuits. The proposed curve fitting methodology can guarantee from 90% to 100% correlation accuracy comparing with SPICE simulation and it can find optimal CNFET SRAM cell parameters without exhaustive simulation time and large memory space. The optimized CNFET SRAM cell by the proposed methodology shows that total power consumption including static power is reduced by 83.14% and the total PDP (product of delay and power) is reduced by 83.39%, comparing with CMOS SRAM cell design. The total runtime is reduced by 96.9% compared with conventional Monte Carlo simulation method in SPICE.
VR 2 interresponse times

Rats with a short VR 2 reinforcement history bar press at a moderate but very steady rate. Individual interresponse time distributions are compact with 2 or 3 sec modes.
Relationship between California Mastitis Test reaction and production and composition of milk from opposite quarters.

Abstract The relationship between the California Mastitis Test (CMT) reaction of milk from individual quarters and production was determined by comparing the production at a single milking, of opposite quarters of the same udder which differed in CMT reaction. Comparisons were obtained for 1,258 opposite-quarter milkings from 763 cows in 30 dairy herds. These opposite-quarter comparisons were well distributed over the lactation period, season of year, and between front and rear halves of the udder. Test reactions (on total quarter milk) of trace, 1, 2, and 3 were associated with average decreases in milk production of 0.42 (9.0%), 0.95 (19.5%), 1.72 (31.8%), and 2.33 (43.4%) kg per quarter per day, respectively. Test reactions of foremilk from 6,600 quarters were distributed as follows: Negative, 36.7%; trace, 14.4%; 1, 27.8%; 2, 10.9%; and 3, 9.6%. Only 0.6% of the quarters were blind or dry at the time of examination. A comparison of the CMT reaction of foremilk and total quarter milk from 3,047 quarters revealed that the two CMT readings were in agreement for 82.5% of the comparisons.
Assessing the factors related to microcomputer usage by middle managers

Although microcomputers have proliferated rapidly within organizations, many microcomputers are acquired and subsequently either under-utilized or not used at all. The variation in usage is especially true of users such as managers, who enjoy a high level of discretion in their use. In this research, drawing upon the innovation literature, we examined the influence of the individual middle manager's characteristics, the characteristics of his or her superior, and organizational facilitation on the variation in microcomputer usage by middle managers. Data was collected from middle managers and their superiors at eight organizations and analysed using path analysis. The analysis revealed that usage is strongly influenced by organizational facilitation and the manager's prior experience with computing, with moderate effects from his or her attitude towards microcomputers. The managers' superiors, on the other hand, were found to have almost no influence. Within facilitation, the influence of consultation was found to be far greater and significant than the influence of training. These findings suggest that as organizations attempt to diffuse microcomputers through the managerial level, individuals in positional power roles cannot be counted on to play the role of change agents. However, policies and initiatives emphasizing consultation could be potential aids.
Science education reform: Building on the research base

Those concerned with science education are united in calling for reform, yet divided in specifying the nature of this reform. Several recent conferences (Gardner et al., 1990; Linn, 1987b; Shymansky & Kyle, 1992) have focused on reform as a joint collaborative process involving experts in cognition, science education, precollege teaching, the subject matter disciplines, teacher preparation, and curriculum design. This article (a) contrasts several perspectives on science education reform by examining recommendations for introductory science courses, (b) identifies research findings that can guide reform, (c) discusses the impact of research on national precollege curriculum reform, and (d) offers a set of recommendations to guide research and practice concerned with science education reform.
Comparison of Maximal Oxygen Consumption Between Black and White Prepubertal and Pubertal Children

The purpose of this investigation was to determine whether maximal oxygen consumption (VO2max) differed between two selected groups of black and white children and whether a difference existed to determine whether it was related to hematologic profiles, body composition, and/or physical activity/inactivity level. Forty-five prepubertal and 42 pubertal, clinically normal black and white children participated. Dual-energy x-ray absorptiometry was used to determine body composition. A computed tomography scan of the abdomen was used to determine visceral adipose tissue and s.c. adipose tissue. Daily physical activity/inactivity was assessed by questionnaire. Black prepubertal and pubertal children had lower VO2max values when compared with white children (28.8 +/- 7.8 versus 35.0 +/- 6.5 mL . kg(-1) . min(-1), p < 0.01; 33.7 +/- 6.4 versus 40.4 +/- 10.2 mL . kg(-1) . min(-1), p < 0.05; respectively). Black prepubertal and pubertal children had lower Hb concentrations ([Hb]) and hematocrits than white children (prepubertal: 12.1 +/- 0.5 versus 12.8 +/- 0.9 g/dL, p < 0.001; 35.6 +/- 1.4 versus 37.4 +/- 2.3%, p < 0.01, respectively; pubertal: 13.0 +/- 0.9 versus 13.6 +/- 0.7 g/dL, p < 0.05; 37.7 +/- 2.5 versus 39.5 +/- 2.1%, p < 0.05, respectively). In conclusion, these findings indicate that black prepubertal and pubertal children had lower VO2max when compared with their white peers matched for age, pubertal stage, and body mass index. This difference in VO2max could be attributed at least in part to comparatively lower [Hb] and more sedentary lifestyle in the black children. Further investigations should study Hb flow rate (a function of [Hb] x maximal cardiac output) in black and white children as it relates to VO2max.
A constrained minimum power adaptive beamformer with time-varying adaptation rate

A linear adaptive algorithm was developed for array beamforming purposes. The design goal for the algorithm is to minimize the squared filter output subject to filter constraints which allow energy propagating from the array steering direction to pass without being distorted. The adaptive filter coefficients were initialized to satisfy the constraints which were preserved during the iterations. The adaptation rate is inversely varied with filter output and total input channel power. Performance of the algorithm was studied using the recorded short‐period array data from the Korean Seismic Research Station. Processed were a high‐amplitude signal from Kamchatka, a medium‐amplitude signal from eastern Kazakh, and a number of low‐amplitude signals from central Eurasia. Results of signal‐to‐noise ratio gain relative to a conventional beamformer among the events tested were consistent and were in the range of 4.5 to 6.5 dB in the wide passband. Much better signal‐to‐noise ratio improvement was obtained in the l...
Determination of mercury by radiorelease of109Cd from a diethyldithiocarbamate chelate and liquid scintillation counting

A radioanalytical procedure is described in which Hg2+, in an aqueous solution, is brought into contact with109Cd-radiolabeled diethyldithiocarbamate (DDTC), in an organic phase. Because Hg2+ forms a much more stable chelate with DDTC than does Cd2+, it displaces (radioreleases)109Cd into the aqueous phase. This latter activity is, linearly related to the concentration of Hg(II) in the sample solution, with excellent linearity down to ≈5ppb. Response factors are reported for a number of ions which may interfere with the determination. Major interferents include Cu2+, Ag+, and Pb2+.
Hox3 genes coordinate mechanisms of genetic suppression and activation in the generation of branchial and somatic motoneurons

In the developing hindbrain, the functional loss of individual Hox genes has revealed some of their roles in specifying rhombomere (r) identity. However, it is unclear how Hox genes act in concert to confer the unique identity to multiple rhombomeres. Moreover, it remains to be elucidated how these genes interact with other transcriptional programs to specify distinct neuronal lineages within each rhombomere. We demonstrate that in r5, the combined mutation of Hoxa3 and Hoxb3 result in a loss of Pax6- and Olig2 -expressing progenitors that give rise to somatic motoneurons of the abducens nucleus. In r6, the absence of any combination of the Hox3 paralogous genes results in ectopic expression of the r4-specific determinant Hoxb1 . This ectopic expression in turn results in the differentiation of r4-like facial branchiomotoneurons within this rhombomere. These studies reveal that members of the Hox1 and Hox3 paralogous groups participate in a `Hox code' that is necessary for coordinating both suppression and activation mechanisms that ensure distinction between the multiple rhombomeres in the developing hindbrain.
High-Resolution Fluid–Structure Interaction Simulations of Flow Through a Bi-Leaflet Mechanical Heart Valve in an Anatomic Aorta

We have performed high-resolution fluid–structure interaction simulations of physiologic pulsatile flow through a bi-leaflet mechanical heart valve (BMHV) in an anatomically realistic aorta. The results are compared with numerical simulations of the flow through an identical BMHV implanted in a straight aorta. The comparisons show that although some of the salient features of the flow remain the same, the aorta geometry can have a major effect on both the flow patterns and the motion of the valve leaflets. For the studied configuration, for instance, the BMHV leaflets in the anatomic aorta open much faster and undergo a greater rebound during closing than the same valve in the straight axisymmetric aorta. Even though the characteristic triple-jet structure does emerge downstream of the leaflets for both cases, for the anatomic case the leaflet jets spread laterally and diffuse much faster than in the straight aorta due to the aortic curvature and complex shape of the anatomic sinus. Consequently the leaflet shear layers in the anatomic case remain laminar and organized for a larger portion of the accelerating phase as compared to the shear layers in the straight aorta, which begin to undergo laminar instabilities well before peak systole is reached. For both cases, however, the flow undergoes a very similar explosive transition to the small-scale, turbulent-like state just prior to reaching peak systole. The local maximum shear stress is used as a metric to characterize the mechanical environment experienced by blood cells. Pockets of high local maximum shear are found to be significantly more widespread in the anatomic aorta than in the straight aorta throughout the cardiac cycle. Pockets of high local maximum shear were located near the leaflets and in the aortic arc region. This work clearly demonstrates the importance of the aortic geometry on the flow phenomena in a BMHV and demonstrates the potential of our computational method to carry out image-based patient-specific simulations for clinically relevant studies of heart valve hemodynamics.
THE GooseMan: a simulator for transhiatal esophagectomy.

Esophageal cancer is the fastest growing cancer in the United States and the seventh leading cause of cancerrelated death worldwide. The gold standard therapy is surgical resection commonly performed as a transhiatal esophagectomy (THE), which involves blindly dissecting the esophagus in the mediastinum through abdominal and cervical neck incisions. Compared with transthoracic esophagectomy, which requires creating a direct thoracic incision, THE has similar long-term survival but is less invasive and has fewer complications, a shorter recovery time, and decreased in-hospital mortality. Yet, morbidity and mortality from THE remain high compared with other thoracic procedures, largely a result of complications that arise during the blind mobilization process, such as injury to blood vessels, pleural entry, tracheobronchial injury, and hypotension and arrhythmia from compression of the heart. Although THE is difficult to perform, it is also difficult to teach because limited space and lack of visualization in the mediastinum minimize opportunities for careful supervision. In addition, learning opportunities are limited because many surgeons perform transthoracic esophagectomy or laparoscopic esophagectomy instead. Surgical simulation may provide a safe and accessible alternative for THE training; however, there are currently no simulators that can be adapted for this operation. Thus, we developed THE GooseMan, a simple bench model for THE simulation training made of synthetic materials along with porcine organs that costs<$200 to build. It includes a plastic torso, artificial diaphragm, large foam lungs, an artificial pressure-detecting heart, aortic and azygous circulation, and a porcine organ block. The model facilitates practice of esophageal mobilization and gastric tubularization while simulating the complications of hypotension as well as aortic and azygous bleeding.
Acyclic diene metathesis (ADMET) polymerization. Synthesis of an unsaturated polyester

La polymerisation par metathese du diundec-10-enoate de l'ethyleneglycol catalysee par un carbene donne le polymere [COOCH 2 CH 2 OCO(CH 2 ) 8 CH=CH(CH 2 ) 8 ] n de masse moleculaire Mn=5400 contenant 80% de liaisons trans et ayant une polydispersion M w /M n de 1,84
Linear filtering of singularly perturbed systems

This short paper considers the properties of singularly perturbed systems with white noise input. The theory of singular perturbations is then applied to the filtering problem for such systems. The resulting filter may be approximately decomposed into two filters in different time scales yielding the estimates of the slow-mode and the fast-mode states.
Medionecrosis aortae idiopathica cystica

Abstract Cystic necrosis of the aortic media is a rarely recognized disease which was first described in 1929 by Erdheim. 1, 2 The cystic degeneration develops in focal accumulations of chromatrophic or mucoid material, with tearing of the elastic laminae of the media and with some evidence of reparatory proliferation of connective tissues. The only thorough review of the pathology of the condition which has been published in English is that of Moritz. 3 He found only twelve cases, 4–9 up to 1932, including three of his own. Glendy, Castleman, and White 10 described typical cystic medionecrosis in eight of their nineteen cases of ruptured dissecting aneurysm; in the others, adequate histologic study had not been made. The condition was present in all five of the cases of "spontaneous" rupture of the aorta due to dissecting aneurysm reported by Klotz and Simpson. 11 Gobel 25 and Milew 26 have reported single cases. Thus, twenty-seven cases of cystic medionecrosis have been found in the literature. All of the patients died from rupture of a dissecting aneurysm. It is evident, therefore, that the condition is of great pathogenic or etiologic significance in dissecting aneurysms. This pathogenic relationship has been overlooked in the otherwise thorough recent reviews of dissecting aneurysm. 12, 13, 14 The purpose of this paper is to report a case of "healed" dissecting aneurysm due to idiopathic cystic medionecrosis of the aorta, in which the clinical and pathologic features were sufficiently distinctive to suggest the possibility of making the diagnosis during life.
Concealed weapons: erectile claws in African frogs

Vertebrate claws are used in a variety of important behaviours and are typically composed of a keratinous sheath overlying the terminal phalanx of a digit. Keratinous claws, however, are rare in living amphibians; their microstructure and other features indicate that they probably originated independently from those in amniotes. Here we show that certain African frogs have a different type of claw, used in defence, that is unique in design among living vertebrates and lacks a keratinous covering. These frogs have sectorial terminal phalanges on their hind feet that become functional by cutting through the skin. In the resting state, the phalanx is subdermal and attached to a distal bony nodule, a neomorphic skeletal element, via collagen-rich connective tissue. When erected, the claw breaks free from the nodule and pierces the ventral skin. The nodule, suspended by a sheath attached to the terminal phalanx and supported by collagenous connections to the dermis, remains fixed in place. While superficially resembling the shape of claws in other tetrapods, these are the only vertebrate claws known to pierce their way to functionality.
The impact of ethnic-religious identification on buyer-seller behaviour: a study of two enclaves

This study examines the behaviour of buyers and sellers in two ethnic enclaves, Catholic Hispanics and Muslim Arabs, within a US metropolitan area. Based upon a sample of 42 small ethnic businesses, a rudimentary activity matrix is constructed for each enclave to reveal the purchases of materials, services, and labour and the sales of finished and semi-finished goods and services. Results suggest that ethnic firms are dependent on co-ethnic business in their enclave, tend to rely more upon the ethnic enclave for labour inputs than for other resources, and that start-up firms rely more on intra-enclave economic exchange than do more mature ethnic firms. The perceived advantage of intra-enclave buying and selling is argued to lie in a sense of ethnic identification that comes primarily from a religion, either Catholic or Muslim, common to each enclave. The dependence on religious organisations for services by new ventures is seen to lessen as the venture matures.
A Trajectory Model for Understanding and Assessing Health Disparities in Immigrant/Refugee Communities

While numerous factors contributing to racial/ethnic health disparities have been identified, the clustering and interaction of these factors as a syndemic or trajectory has not been well-studied (Starfield in Soc Sci Med 64:1355–1362, 2007; Singer in Soc Sci Med 39(7):931–948, 1994). More importantly, for immigrant/refugee populations, the interaction of contributing factors is not documented adequately enough to provide a solid framework for planning, implementation and evaluation of interventions aimed at reducing disparities. In this paper, the authors draw from the literatures on health disparities and immigrant/refugee health, as well as direct program and research experience, to propose an approach for assessment of the diachronic interaction of ecological factors (a trajectory, or “diachronic ecology”) contributing to health disparities among immigrant/refugee populations. It is our hope that this approach will contribute to the important effort to collect data supporting the development of interventions and policies that effectively address the dynamic processes through which health disparities are created, maintained, and changed.
IL-4-independent inhibition of IL-12 responsiveness during Leishmania amazonensis infection

Leishmania amazonensis induces a nonhealing infection in C3H mice, whereas infection with Leishmania major is self-healing. We found that C3H mice infected with L. amazonensis exhibited decreased IL-12 production, which could account for the susceptibility to this organism. However, exogenous IL-12 administration failed to induce a healing immune response. The failure of L. amazonensis-infected C3H mice to respond to IL-12 was associated with a specific defect in IL-12 receptor beta2 (IL-12Rbeta2) mRNA expression by CD4+ T cells. Furthermore, decreased IL-12Rbeta2 mRNA expression correlated with a decrease in the IL-12-signaling capacity of the lymph node (LN) cells. IL-4 did not contribute to susceptibility or down-regulation of the IL-12Rbeta2 subunit, because IL-4-/- mice remained susceptible to L. amazonensis infection, even after IL-12 administration, and CD4+ cells from infected IL-4-/- mice also had reduced expression of IL-12Rbeta2 mRNA. These results demonstrate that regulation of the IL-12 receptor, independent of IL-4, is a point of control for the immune response to leishmaniasis. In contrast to experimental L. major infections, where host genetics control susceptibility, these studies demonstrate that the lack of IL-12 responsiveness may be dictated by the pathogen, rather than the host.
Ferromagnetism of magnetically doped topological insulators in CrxBi2−xTe3 thin films

We investigated the effect of magnetic doping on magnetic and transport properties of Bi2Te3 thin films. CrxBi2−xTe3 thin films with x = 0.03, 0.14, and 0.29 were grown epitaxially on mica substrate with low surface roughness (∼0.4 nm). It is found that Cr is an electron acceptor in Bi2Te3 and increases the magnetization of CrxBi2−xTe3. When x = 0.14 and 0.29, ferromagnetism appears in CrxBi2−xTe3 thin films, where anomalous Hall effect and weak localization of magnetoconductance were observed. The Curie temperature, coercivity, and remnant Hall resistance of thin films increase with increasing Cr concentration. The Arrott-Noakes plot demonstrates that the critical mechanism of the ferromagnetism can be described better with 3D-Heisenberg model than with mean field model. Our work may benefit for the practical applications of magnetic topological insulators in spintronics and magnetoelectric devices.
Pax6−/− Mice Have a Cell Nonautonomous Defect in Nonradial Interneuron Migration

The mammalian neocortex comprises two major neuronal subtypes; interneurons derived from the ganglionic eminence (GE) and projection neurons from the cortical ventricular zone (VZ). These separate origins necessitate distinct pathways of migration. Using mouse genetics and embryonic forebrain slice culture assays, we sought to identify substrates and/or guidance molecules for nonradial cell migration (NRCM). Mice carrying a mutation in Pax6 (Sey −/− ), a paired domain transcription factor, are reported to have increased numbers of cortical inhibitory interneurons, suggesting that Pax6 could induce inhibitors of interneuron development or alternatively play a repressive role in guiding NRCM and/or specifying interneurons. Unexpectedly, we found a cell nonautonomous reduction in the distance Sey −/− neurons migrated, reflecting a disorganized migration, with frequent changes in direction. In contrast, no difference in the number of nonradially migrating GE cells was observed in Sey −/− mice. Our data indicate that the increased numbers of interneurons observed in Sey −/− do not result from an increased rate or number of nonradially migrating cells; instead, loss of Pax6 results in the ectopic specification of interneurons in the cortical VZ. Further, our data indicate that the known axonal disorganization in Sey −/− mice contributes to the observed reduced distance of NRCM.
The variety of relations between spatial frequency and reaction time

While stimuli of lower spatial frequency often result in faster responses, this is not invariably the case. Some individuals respond faster to high frequency stimuli on tasks for which most others respond faster to low frequency stimuli. Past experience can also determine the degree to which a low frequency stimulus will mask a high frequency stimulus. These observations suggest that the effects of spatial frequency on visual information processing are under the control of higher level cognitive operations.
The Evolution of Innovation Across Web 2.0 Platforms Through Mutation, Natural Selection, and Reuse

This paper examines the question of how innovations diffuse across web 2.0 business designs and affect change at the industry level. We apply evolutionary theory as a theoretical lens and conceptualize the adoption and diffusion of innovations as a dynamic process where innovations propagate vertically within firms via successive product releases as well as horizontally across firms via imitation and replication. We develop a formal stochastic process model that allows us to design a multi-level study that examines which innovations survive in the market and which do not and if and under what conditions industry standardization is achieved.
Developing norms for cyber conflict

The prospect of cyber war has evolved from science fiction and doomsday depictions on television, films, and novels to reality and front page news. As early as 1982, a little-noticed but massive explosion of the trans-Siberian pipeline was caused by malware apparently inserted into Canadian software by the CIA. The CIA and Canadians knew that the software would be illegally acquired by Soviet agents. Although the incident greatly embarrassed the KGB, the Soviets never disclosed the incident or accused the United States of causing it. If a U.S. missile had struck the pipeline, the Soviets would have expressed their outrage publicly and almost surely would have retaliated.
Er/Yb glass laser with compact mechanical Q-switch

We describe a compact, side-pumped, Er/Yb glass laser with a low cost mechanical Q-switch. The Q-switch uses a mirror or reflecting prism mounted on a cantilever resonant spring that is driven by a small electromagnetic coil. The demonstrated laser used a 5 mm long Er/Yb glass gain element, and was side-pumped by a 940 nm, 5 mm wide diode bar generating up to 100 W peak power. Target energies of 3mJ have been realized in a near-diffraction limited mode, with pulse widths of 15-25ns, and an optical-to-optical efficiency of greater than 2%. The mechanical Q-switch assembly was fully athermalized via mounting a displacing porro reflector to the cantilever spring, where a 2.5mJ laser was observed to operate with less than 5% variance over -35°C to+60°C.
Inheritance of Permethrin Resistance in the Tobacco Budworm (Lepidoptera: Noctuidae)

Permethrin resistance in the tobacco budworm, Heliothis virescens (F.), was inherited as a single, major, incompletely recessive, autosomal factor. In each of two parental resistant strains, backcrosses to their respective hybrids demonstrated segregation. A distinct plateau in mortality from 50 to 500 µg/g larva was observed. High, stable permethrin resistance (ca. 540-fold) was observed only after outcrossing to a susceptible strain and selecting for the most resistant inbred lines. The single, segregating factor observed probably conferred insensitivity of the target site in the nervous system. Evidence for the existence of this major resistance mechanism and other minor resistance factors in these H. virescens strains will be published elsewhere. These observations, coupled with the apparent lack of reproductive disadvantage among resistant individuals, suggest that stable pyrethroid resistance may develop and threaten resistance management.