cssi/SciSciGPT-SciSciNet huggingface dataset:
Efficient spin injection and extraction in modified reverse and forward biased ferromagnetic–semiconductor junctions and low-power ultrafast spin injection devices

This paper addresses recent theoretical and experimental advances in obtaining large spin polarization in semiconductors. In particular, we describe tunneling of electrons between nonmagnetic semiconductors (S) and ferromagnets (FM) through a Schottky barrier modified by very thin heavily doped interfacial layer. It is shown that in such reverse (forward) biased FM-S junctions electrons with a certain spin projection can be efficiently injected in (extracted from) S. This occurs due to spin filtering of electrons in a tunneling process. We find conditions for most efficient extraction and accumulation of spin and show that spin polarization of electrons near the interface can, at least in principle, be made close to 100% in nondegenerate S at room temperature and certain bias voltages. Extraction of spin can proceed in degenerate semiconductors at any (low) temperature. A new class of spin valve ultrafast devices with small dissipated power is described: a magnetic sensor, a spin transistor, an amplifier, a frequency multiplier, and a square-law detector.
Peroxidative Metabolism of β2-Agonists Salbutamol and Fenoterol and Their Analogues

Phenolic β2-adrenoreceptor agonists salbutamol, fenoterol and terbutaline relax smooth muscle cells that relieve acute airway bronchospasm associated with asthma. Why their use sometimes fails to relieve bronchospasm, and why the drugs appear to be less effective in patients with severe asthma exacerbations, remains unclear. We show that in the presence of hydrogen peroxide, both myeloperoxidase, secreted by activated neutrophils present in inflamed airways, and lactoperoxidase, which is naturally present in the respiratory system, catalyze oxidation of these β2-agonists. Azide, cyanide, thiocyanate, ascorbate, glutathione, and methimazole inhibited this process, while methionine was without effect. Inhibition by ascorbate and glutathione was associated with their oxidation to corresponding radical species by the agonists’-derived phenoxyl radicals. Using electron paramagnetic resonance (EPR), we detected free radical metabolites from β2-agonists by spin trapping with 2-methyl-2-nitrosopropane (MNP). Formation of these radicals was inhibited by pharmacologically-relevant concentrations of methimazole and dapsone. In alkaline buffers radicals from fenoterol and its structural analog, metaproteronol, were detected by direct EPR. Analysis of these spectra suggests that oxidation of fenoterol and metaproterenol, but not terbutaline, causes their transformation through intramolecular cyclization by addition of their amino nitrogen to the aromatic ring. Together, these results indicate that phenolic β2-agonists function as substrates for airway peroxidases and that the resulting products differ in their structural and functional properties from their parent compounds. They also suggest that these transformations can be modulated by pharmacological approaches using appropriate peroxidase inhibitors or alternative substrates. These processes may affect therapeutic efficacy and also play a role in adverse reactions of the β2-agonists.
Agricultural Productivity in America and Eastern Europe: A Comment

Gregory Clark compares labor productivity in America, Great Britain, and Eastern Europe and shows how much less productive East European peasants were than their counterparts in the other two countries.' He suggests that grain output per male worker in agriculture in the northeastern United States was 308 bushels per year in 1850 whereas on one Polish estate in 1825 it was only 70 bushels, and on a Bohemian estate 130 bushels in 1841. In short, labor-productivity differences in grain production were large. He goes on to argue that the difference was not caused by a higher land/labor ratio in America because this advantage was only about 22 percent. Finally, he assumes that agricultural technology and soil quality were the same in the various economies. By eliminating the factors that, in principle, could have contributed to the large differences in partial factor productivities, he is left with a residual explanation: workers must have worked much harder in North America than in Eastern Europe. According to Clark, "the greater intensity with which American and British workers performed ordinary farm labor was the major explanation of why output per worker and wages were high in America and Britain."2 In concluding he reiterates: "the people in the low-productivity areas were different from the people we are familiar with. Either they worked little or they exerted themselves little when at work (that is, they had different tastes) or their mental life is otherwise alien to us. They were not merely people like us who happened to be lacking certain pieces of knowledge."3 I shall argue that Clark failed to measure labor-productivity differences accurately, and that none of his assumptions is warranted: every single implement used in the two systems differed markedly during the period under consideration, and the difference always favored the American farmer. Moreover, the soil quality, horsepower employed, fertilizer availability, were not the same in the various countries, and the land to labor ratios were farther apart than Clark asserted. In short, technology, institutions, and incentive structure were worlds apart-everything differed. In arguing this case I leave Great Britain out of the discussion for the sake of brevity. Clark's data can be shown to be implausible if one substitutes his figures into a Cobb-Douglas production function.4 If the two agricultural systems were truly comparable, and both used about the same technology and the same amount of manure per acre, with the same horsepower, and produced the same product mix, and the American farmers with only 22 percent more land produced 2.4 to 4.4 times as much output as East European peasants, then one can calculate the efficiency of American farmers relative to that of the East European peasants. Clark's analysis implies that American farmers
Echocardiographic indexes of rejection in pediatric cardiac transplant recipients managed without maintenance steroid immunosuppression

Abstract In this investigation, of the parameters evaluated, we demonstrated that Doppler flow velocity patterns through the mitral valve may be useful for detecting cardiac allograft rejection in children. However, the findings in our investigation compared with results reported by others suggest that the use of noninvasive indexes for detection of cardiac rejection may be more discriminating in pediatric patients not receiving steroid immunosuppression therapy.
Mobile apps for pediatric obesity prevention and treatment, healthy eating, and physical activity promotion: just fun and games?

Mobile applications (apps) offer a novel way to engage children in behavior change, but little is known about content of commercially available apps for this population. We analyzed the content of apps for iPhone/iPad for pediatric weight loss, healthy eating (HE), and physical activity (PA). Fifty-seven apps were downloaded and tested by two independent raters. Apps were coded for: inclusion of the Expert Committee for Pediatric Obesity Prevention's (ECPOP) eight recommended strategies (e.g., set goals) and seven behavioral targets (e.g., do ≥1 h of PA per day), utilization of gaming elements, and general characteristics. Most apps lacked any expert recommendations (n = 35, 61.4 %). The mean number of recommendations among apps that used recommendations was 3.6 ± 2.7 out of 15, 56.1 % (n = 32) apps were classified as games, and mean price per app was $1.05 ± 1.66. Most apps reviewed lacked expert recommendations and could be strengthened by addition of comprehensive information about health behavior change and opportunities for goal setting.
The possible association of phytoalexins with resistance gene expression in flax to Melampsora lini

Two antifungal compounds, coniferyl alcohol and coniferyl aldehyde, were isolated from facilitated dilusates of flax leaves inoculated with incompatible races of Melampsora lini. The two phenylpropanoid compounds accumulated more rapidly in all incompatible reactions than in compatible. In addition, the compounds accumulated more rapidly in resistance genotypes typified by rapid restriction of fungus growth and smaller lesions than in resistance genotypes typified by later restriction of fungus growth and larger lesion areas. Phloroglucinol stained incompatible infection sites, but not those of compatible sites, thus indicating that coniferyl aldehyde accumulation and perhaps induced lignification occurred in the incompatible sites. Initial detection of phloroglucinol-staining was chronologically correlated with the cessation of fungus growth and inversely correlated with ultimate lesion size. The evidence indicated that de novo production of coniferyl alcohol and coniferyl aldehyde may be the mechanism for restriction of fungus growth in incompatible flax leaves and that the phenylpropanoid compounds may represent phytoalexins effective against M. lini.
Tsunami Produced by the Impacts of Small Asteroids

ABSTRACT: The fragmentation of a small asteroid in the atmosphere greatly increases its cross section for aerodynamic braking, so ground impact damage (craters, earthquakes, and tsunami) from a stone asteroid is nearly negligible if it is less than 200 meters in diameter. A larger one impacts the ground at nearly its velocity at the top of the atmosphere producing considerable impact damage. The protection offered by Earth's atmosphere is insidious in that smaller, more frequent impactors such as Tunguska only produce air blast damage and leave no long-term scars on the Earth's surface, while objects 2.5 times larger than it, which hit every few thousand years, cause coherent destruction over many thousands of kilometers of coast. Smaller impactors give no qualitative warning of the enormous destruction wrought when an asteroid larger than the threshold diameter of 200 meters hits an ocean. A water wave generated by an impactor has a long range because it is two-dimensional, so its height falls off inversely with distance from the impact. When the wave strikes a continental shelf, its speed decreases and its height increases to produce tsunamis. The average runup in height between a deep-water wave and its tsunami is more than an order of magnitude. Tsunamis produce most of the damage from asteroids with diameters between 200 meters and 1 km. An impact anywhere in the Atlantic by an asteroid 400 meters in diameter would devastate the coasts on both sides of the ocean by tsunami over 100 meters high. An asteroid 5 km in diameter hitting in mid Atlantic would produce tsunami that would inundate the entire upper East Coast of the United States to the Appalachian Mountains. Studies of ocean sediments may be used to determine when coastal areas have been hit by tsunamis in the past. Tsunami debris has been found to be associated with the Cretaceous-Tertiary impact and should be detectable for smaller impacts.
High-Dose Steroid Therapy Offers Improvement in Spinal Cord Injuries

A spinal-cord injury can alter every aspect of a victim's life. Despite continued improvements in mortality associated with a spinal-cord injury, until recently little progress had been made in improving neurologic function. This paper reviews the development of steroid therapy for spinal cord injuries, the mechanisms of action, and the nursing care associated with its use.
Genetic diversity of Sclerotinia species from Alaskan vegetable crops

White mold diseases are prevalent and difficult to manage on vegetable crops in the Matanuska Valley, the main agricultural region of Alaska. Prior research on Sclerotinia sclerotiorum, the primary white mold pathogen throughout the world, has shown it to be predominantly clonal in cool temperate regions, whereas sexual recombination contributes to the population structure in milder climates. We examined the population structure of the fungus in the subarctic region of Alaska to determine whether the trend towards clonality is sustained at more extreme latitudes. Microsatellite and ribosomal DNA markers revealed that S. sclerotiorum populations in Alaska comprise predominantly, if not exclusively, nonrecombining clonal lineages. Surprisingly, many diseased plants were found to be infected by the cryptic Sclerotinia sp. 1, a closely related fungus previously reported on wild plant species and cultivated potato from Norway. In some fields, Sclerotinia sp. 1 was the only pathogen involved in disease. However...
Improvement of hemostasis in open and laparoscopically performed partial nephrectomy using a gelatin matrix-thrombin tissue sealant (FloSeal).

Abstract Objectives Long-term follow-up studies have demonstrated that effective local tumor control and long-term tumor-free progression rates can be achieved by nephron-sparing surgery. However, hemostasis is a major issue, and the lack of effective means of hemostasis has limited the wider use of the laparoscopic approach to nephron-sparing surgery. Methods Between January 2001 and April 2002, 25 patients with renal cell carcinoma were treated with partial nephrectomy using a two-component tissue sealant (FloSeal). The median age was 54 years (range 42 to 71). The follow-up time was 1 to 12 months (median 3.5). The tumor diameter ranged from 2 to 5 cm (median 2.8). Fifteen cases were performed by open retroperitoneal surgery, and 10 cases were performed laparoscopically. The two-component tissue sealant (consisting of a gelatin matrix granula component and a thrombin component) was applied after resection of the tumor and before perfusion of the kidney. The following parameters were recorded: time until complete hemostasis was achieved; decrease in postoperative hemoglobin level; postoperative bleeding; and presence or absence of a perirenal hematoma 24 hours and 10 days postoperatively by ultrasonography. Results After application of the tissue sealant for 1 to 2 minutes to the moist resection site, hemostasis was immediate in all cases. During the laparoscopically performed partial nephrectomies, a laparoscopic applicator was used to avoid wasting the tissue sealant within the dead space of the instrument. When reperfusion of the kidney was established, hemostasis was maintained. The decrease in postoperative hemoglobin level ranged from 0.3 to 1.2 points (median 0.7). None of the patients required blood transfusions. No postoperative bleeding occurred. The ultrasound examination 24 hours and 10 days postoperatively demonstrated the absence of a significant perirenal hematoma. Conclusions The two-component tissue sealant FloSeal provided immediate and durable hemostasis in open and laparoscopically performed partial nephrectomies. The tissue sealant may provide a tool to expand the possibilities of laparoscopic nephron-sparing surgery.
Childhood obesity: are genetic differences involved?

This brief review focuses on the genetic contribution to childhood obesity. Evidence for a genetic component to excess body weight during growth is presented from the perspective of genetic epidemiology studies. Parental obesity is a predictor of childhood excess weight. The familial risk ratio for childhood obesity when a parent is obese reaches >2.5. Birth weight is characterized by a genetic heritability component on the order of 30%, with significant maternal and paternal effects in addition to the newborn genes. About 5% of childhood obesity cases are caused by a defect that impairs function in a gene, and ≥5 of these genes have been uncovered. However, the common forms of childhood obesity seem to result from a predisposition that primarily favors obesogenic behaviors in an obesogenic environment. Candidate gene and genomewide association studies reveal that these obesogenic genes have small effect sizes but that the risk alleles for obesity are quite common in populations. The latter may translate into a highly significant population-attributable risk of obesity. Gene-environment interaction studies suggest that the effects of predisposing genes can be enhanced or diminished by exposure to relevant behaviors. It is possible that the prevalence of childhood obesity is increasing across generations as a result of positive assortative mating with obese husbands and wives contributing more obese offspring than normal-weight parents.
Farm and Enterprise Diversification in East Europe and Central Asia

This paper presents issues and challenges for farm and enterprise diversification and integration of small scale farmers into value chains in East Europe and Central Asia (EECA). First, it discuses context and approaches to agricultural and rural income diversification. Second, it assesses the extent of agricultural diversification in EECA. Third, it identifies issues, challenges and lessons learnt of the integration of small farmers into agricultural value chains in the region. Forth, it outlines options and areas of intervention to foster diversification and market inclusion of smallholders in EECA. Finally, it concludes with recommendations for improvement of public policies and international assistance.
N-terminal domains of fibrillin 1 and fibrillin 2 direct the formation of homodimers: a possible first step in microfibril assembly

Aggregation of fibrillin molecules via disulphide bonds is postulated to be an early step in microfibril assembly. By expressing fragments of fibrillin 1 and fibrillin 2 in a mammalian expression system, we found that the N-terminal region of each protein directs the formation of homodimers and that disulphide bonds stabilize this interaction. A large fragment of fibrillin 1 containing much of the region downstream from the N-terminus remained as a monomer when expressed in the same cell system, indicating that this region of the protein lacks dimerization domains. This finding also confirms that the overexpression of fibrillin fragments does not in itself lead to spurious dimer formation. Pulse-chase analysis demonstrated that dimer formation occurred intracellularly, suggesting that the process of fibrillin aggregation is initiated early after biosynthesis of the molecules. These findings also implicate the N-terminal region of fibrillin 1 and fibrillin 2 in directing the formation of a dimer intermediate that aggregates to form the functional microfibril.
S0, Where Is It?

The era of high resolution structural analysis of K+ channels began a decade ago when Rod MacKinnon and colleagues reported the x-ray structure of KcsA, a prokaryotic channel comprising four subunits ([Doyle et al., 1998][1]). Each subunit of KcsA contains two transmembrane (TM) segments that
Mycotic pseudoaneurysm of the ascending aorta

A 49-year-old man consulted for progressive dyspnoea and bilateral lower extremity oedema. His history included a hospital admission because of a multi-resistant Escherichia coli septicaemia 3 years before. Transthoracic echocardiography revealed a calcified mass adjacent to the aortic root ( Panel A ). Transoesophageal echocardiogram showed a large ascending aorta pseudoaneurysm originating at the level of Valsalva sinuses, and communicating with the anterior aspect of the aortic …
Symmetry breaking in the spectrum generating group and its experimental tests

The theoretical assumptions of the Spectrum Generating Groups (SGG) are explained in detail and then the theory is applied to the hyperon semileptonic decays and the hyperon magnetic moments. It is shown that all experimental data can be explained in the SGG frame but there are some serious discrepancies in the stan dard Cabibbo model. It is explained how the mass splitting in the octet is taken consistently into account by the SGG.
Simulation of tendon transfer surgery.

A biomechanical model is used to simulate a tendon transfer operation. The model predicts the required forces in twelve ankle muscles during standing and walking, and also the endurance time of the (instantaneous) posture. In particular, the mechanical effect of anterior transfer of the posterior tibial tendon of a patient with muscle paralysis due to peroneal nerve injury is studied.The results show that before surgery the patient can stand normally but cannot walk normally. Normal walking is mechanically not possible because the required muscle forces in early stance cannot be produced, although the necessary forces can be realized during the remainder of stance. After surgery, both normal standing and normal walking are mechanically possible. The cost is higher forces and shorter endurance times in the healthy muscles. The results agree with clinical findings.
Obesity is Associated with Atypia in Breast Ductal Lavage of Women with Proliferative Breast Disease

Background: Benign proliferative breast disease without atypia slightly increases breast cancer risk but there are currently few clinical options for breast cancer prevention in this group of women. Methods: We conducted a pilot study of women with a past diagnosis of proliferative breast disease with a goal to determine if the characteristics of cells obtained by breast ductal lavage were related to nutritional factors. Results: There were 57 women who enrolled. A total of 39 women yielded nipple aspirate fluid (NAF) samples and 36 underwent breast ductal lavage. Five of the lavage samples were acellular and 28 had at least 200 cells. Surprisingly, atypia was present in 11 women. Presence of atypia was associated with slight changes in morphometric features of the epithelial cells such as measures of circularity as obtained by image analysis, but the only variable significantly different in women with atypia (versus no atypia) was a higher mean body mass index. Body mass index was also significantly correlated with C-reactive protein (CRP) levels in the nipple aspirate fluid, indicating that obesity might have a pro-inflammatory effect on the breast that can contribute to increased rates of atypia. Conclusions: Although the clinical significance of atypia in breast ductal lavage is uncertain, these results support further work on prevention of obesity as a strategy for reducing breast cancer risk.
Tracheal fenestration: a critical evaluation.

SUMMARY 1.Surgery plays an important but limited role in the treatment of the emphysema patient. By far, the intensity of application of medical measures is the dominant factor in determining the final outcome. 2.Tracheal fenestration yields results which in our hands are no better than standard tracheostomy. When examined critically, tracheal fenestration has the disadvantage of not fulfilling all the functions expected of a tracheal stoma.
Crystal Structures of Candida albicans Dihydrofolate Reductase Bound to Propargyl-Linked Antifolates Reveal the Flexibility of Active Site Loop Residues Critical for Ligand Potency and Selectivity.

Candida albicans and Candida glabrata cause fungal bloodstream infections that are associated with significant mortality. As part of an effort to develop potent and selective antifolates that target dihydrofolate reductase (DHFR) from Candida species, we report three ternary crystal structures of Candida albicans DHFR (CaDHFR) bound to novel propargyl-linked analogs. Consistent with earlier modeling results, these structures show that hydrophobic pockets in the binding site may be exploited to increase ligand potency. The crystal structures also confirm that loop residues Thr 58- Phe 66, which flank the active site and influence ligand potency and selectivity, adopt multiple conformations. To aid the development of a dual Candida spp. inhibitor, three new crystal structures of C. glabrata DHFR (CgDHFR) bound to similar ligands as those bound in the ternary structures of CaDHFR are also reported here. Loop residues 58-66 in CgDHFR and human DHFR are 1 A and 3 A closer to the folate binding site, respectively, than loop residues in CaDHFR, suggesting that a properly size ligand could be a potent and selective dual inhibitor of CaDHFR and CgDHFR.
Preclinical Efficacy of Novel Vesicular Monoamine Transporter 2 Inhibitors as Antagonists of d-Methamphetamine Self-Administration in Rats

A series of studies by Drs. Linda Dwoskin and Michael Bardo demonstrated the preclinical efficacy of novel vesicular monoamine transporter 2 (VMAT2) inhibitors as antagonists of d-methamphetamine self-administration in rats.
Biosocial Approaches: Crime

Over the past two decades, scholars have discovered a host of information regarding genes, brain activity, and other biological processes. Many of these biological discoveries are related to behavior. Biosocial approaches to crime examine the way that biological factors such as genes and the brain affect environmental factors and influence criminality over the life course. This article provides an overview of the evolution, main approaches, and contributions of biosocial criminology to linking the way that both nature and nurture influence criminality.
ANP-mediated volume depletion attenuates renal responses in humans.

Brief low-dose infusions of atrial natriuretic peptide (ANP) that emulate physiological plasma concentrations in humans have little if any effect on renal excretory function. This study explored the possibility that ANP-mediated reductions in cardiac filling pressures (through ANP's rapid effect on capillary dynamics) could attenuate its purported renal effects. Protocol A consisted of 16 healthy subjects (ages 19-27 yr old) who underwent three consecutive 45-min experimental sequences: 1) placebo, 2) ANP (10 ng.kg-1 x min-1), and 3) ANP alone (n = 8) or ANP with simultaneous lower body positive pressure (LBPP, n = 8). Electrocardiogram and direct measures of arterial and central venous pressures were continuously monitored. Blood was sampled at the end of each 45-min sequence before subjects stood to void. Compared with control (placebo), ANP produced a hemoconcentration and increased plasma norepinephrine, but did not change heart rate, blood pressure, plasma levels of renin, aldosterone, or vasopressin, or renal excretion of volume or sodium. In subjects receiving LBPP to maintain central venous pressure during the last 45 min of ANP infusion, norepinephrine did not increase and urine volume and sodium excretion increased (P < 0.05). In a second study (protocol B), five healthy subjects received a placebo infusion for 45 min followed by two consecutive 45-min infusions of ANP (10 ng.kg-1 x min-1). Central venous pressure was maintained (LBPP) at placebo baseline throughout the two ANP infusion periods. Urine volume and sodium excretion rates increased progressively and significantly during both ANP infusion periods (P < 0.05) without significant changes in creatinine clearance, blood pressure, or heart rate.(ABSTRACT TRUNCATED AT 250 WORDS)
Human (In)Security, Social Identity Group and Jihadi Terrorist Groups in Africa: al-Shabaab, Boko Haram and AQIM

This paper examines the link between human insecurity and social identity groups. It is argued that pervasive insecurity, necessitated by a weak and fragile state system and coupled by weak governance, encourages individuals to identify with radical Islamic groups. One way to address this problem is by promoting a stronger human security discourse in addressing the root causes of terrorism.
Well, what time is it?

Dusk, then darkness, settled over the large crowd facing the Sphinx and the Great Pyramid at Giza. Soon, only the stars dimly lit the scene. Then a powerful array of lights shone on the Sphinx and an English voice proclaimed, "I am the Pharaoh! The Pharaoh fears only time! Time fears only the Pyramid!" At that moment, other lights illuminated the Great Pyramid, Cheops (Fig. 1). I felt a slight shiver as I contemplated the centuries embodied in the panorama before me, and, as a young metrologist, I couldn?t help wondering about the possibility that time, perhaps the most relentless of life's forces, could know fear. I had no idea how my hosts, staff members of the Egyptian standards agency, perceived the sound-and-light display, but some forty years later I still remember it well.
From Demon to Darling: A Legal History of Wine in America

From Demon to Darling: A Legal History of Wine in America Richard Mendelson, 2009 Berkeley, University of California Press, 320 pp., $40.00/£27.95, hardcover ISBN 9780520259430 Anyone who has tried...
Continuum Models of Stimuli-responsive Gels

Immersed in a solution of small molecules and ions, a network of long-chain polymers may imbibe the solution and swell, resulting in a polymeric gel. Depending on the molecular structure of the polymers, the amount of swelling can be regulated by moisture, mechanical forces, ionic strength, electric field, pH value, and many other types of stimuli. Starting from the basic principles of non-equilibrium thermodynamics, this chapter formulates a field theory of the coupled large deformation and mass transportation in a neutral polymeric gel. The theory is then extended to study polyelectrolyte gels with charge-carrying networks by accounting for the electromechanical coupling and migration of solute ions. While the theoretical framework is adaptable to various types of material models, some representative ones are described through specific free-energy functions and kinetic laws. A specific material law for pH-sensitive gels—a special type of polyelectrolyte gels—is introduced as an example of incorporating chemical reactions in modeling stimuli-responsive gels. Finally, a simplified theory for the equilibrium but inhomogeneous swelling of a polymeric gel is deduced. The theory and the specific material models are illustrated through several examples.
Cytoskeletal mechanics in confluent epithelial cells probed through integrins and E-cadherins

Mechanical forces associated with the cytoskeleton (CSK) and transmitted to adjacent cells or to the extracellular matrix (ECM) influence cellular functions. We investigated the force transfer across cell-to-ECM and cell-to-cell connections using magnetic twisting cytometry. We probed the CSK through integrins and E-cadherins in confluent epithelial cell lines (MCF7). At high applied stress (> 10 dyn/cm2), stiffness (stress/strain) of the CSK coupled through integrins was greater than stiffness coupled through E-cadherins. The stiffness reduction after microfilament or microtubule disruption with cytochalasin D or colchicine was greater for integrins. At low applied stress, disruption of microfilaments had very little effect on stiffness probed through either receptor type, indicating a correspondingly small contribution of microfilaments to the CSK mechanics in these confluent cells. This differs from results in nonconfluent MCF7 cells and from predictions that are based on prestressed models in which tensile stresses presumably associated with the microfilaments are the origin of prestress and, in consequence, cell stiffness. In addition, there was substantial cell spreading on collagen I-coated dishes, in contrast to little spreading on dishes coated with E-cadherin antibody. This result, together with observations of a relatively high cell stiffness probed through integrins compared with the small stiffness probed through E-cadherins, suggests that mechanical force transmission might also be important in regulating cell spreading. We conclude that the degree of confluency may be associated with different mechanics and functions of the CSK network.
Medical Student Core Clinical Ultrasound Milestones: A Consensus Among Directors in the United States

Objectives Many medical schools are implementing point-of-care ultrasound in their curricula to help augment teaching of the physical examination, anatomy, and ultimately clinical management. However, point-of-care ultrasound milestones for medical students remain unknown. The purpose of this study was to formulate a consensus on core medical student clinical point-of-care ultrasound milestones across allopathic and osteopathic medical schools in the United States. Directors who are leading the integration of ultrasound in medical education (USMED) at their respective institutions were surveyed. Methods An initial list of 205 potential clinical ultrasound milestones was developed through a literature review. An expert panel consisting of 34 USMED directors across the United States was used to produce consensus on clinical ultrasound milestones through 2 rounds of a modified Delphi technique, an established anonymous process to obtain consensus through multiple rounds of quantitative questionnaires. Results There was a 100% response rate from the 34 USMED directors in both rounds 1 and 2 of the modified Delphi protocol. After the first round, 2 milestones were revised to improve clarity, and 9 were added on the basis of comments from the USMED directors, resulting in 214 milestones forwarded to round 2. After the second round, only 90 milestones were found to have a high level of agreement and were included in the final medical student core clinical ultrasound milestones. Conclusions This study established 90 core clinical milestones that all graduating medical students should obtain before graduation, based on consensus from 34 USMED directors. These core milestones can serve as a guide for curriculum deans who are initiating ultrasound curricula at their institutions. The exact method of implementation and competency assessment needs further investigation.
Student Movement in Social Context The Influence of Time, Peers, and Place

Higher rates of school switching by students contribute to achievement disparities and are typically theorized as driven by attributes of individual pupils or families. In contrast the neoclassical-economic account postulates that switching is necessary for competition among schools. We argue that both frames fail to capture social-referential and institutional comparisons that drive student mobility, hypothesizing that pupil mobility stems from the (a) student’s time in school and grade; (b) student’s race, class, and achievement relative to peers; (c) quality of schooling relative to nearby alternatives; and (4) proximity, abundance, and diversity of local school options. Propositions are tested with discrete-time hazard models using data from Los Angeles, including 6.5 million observations. We find the student’s position relative to peers, relative school quality, and proximity to local alternatives contribute significantly to the likelihood of switching schools, beyond the effects of individual pupil ...
Nonelastic Cross Sections of Pb 206 and Pb 208 for 14-MeV Neutrons

Measurements of the nonelastic cross sections of ${\mathrm{Pb}}^{206}$, ${\mathrm{Pb}}^{208}$, Cu, and Bi for 14-MeV neutrons by the sphere transmission technique are reported. The results are as follows: ${\mathrm{Pb}}^{206}$, 2.50\ifmmode\pm\else\textpm\fi{}0.05 b; ${\mathrm{Pb}}^{208}$, 2.58\ifmmode\pm\else\textpm\fi{}0.09 b; Bi, 2.53\ifmmode\pm\else\textpm\fi{}0.05 b; Cu, 1.44\ifmmode\pm\else\textpm\fi{}0.03 b. The values for ${\mathrm{Pb}}^{206}$ and ${\mathrm{Pb}}^{208}$ were computed from the measured nonelastic cross sections of ordinary lead, 2.53\ifmmode\pm\else\textpm\fi{}0.05 b, and of radiogenic lead, 2.50\ifmmode\pm\else\textpm\fi{}0.04 b. The difference in the cross sections of ${\mathrm{Pb}}^{206}$ and ${\mathrm{Pb}}^{208}$ is much less than that predicted from the one-body alpha decay theory.
Longstanding Design: Roman Engineering of Aqueduct Arcades

AbstractAncient Roman engineers are famous for their use of arcades, or arched bridges, to elevate roads and aqueducts across valleys. The Romans first designed and built arches using stone blocks and then later changed to special concrete construction. In this paper, we illustrate how early unmortared arches could have been built using geometric design principles. This simplified analysis is sufficient to demonstrate, via retrospective analysis, the need for reconstruction efforts for arches violating these design criteria. Well-preserved remnants at the Simian Bridge and Vallon des Arcs arcades, located in southern France near Arles, are excellent examples of Roman arch engineering and are used as case studies to understand geometric arch design in practice. These arcades are vital parts of a larger aqueduct system used to provide the water-powered industrial Barbegal Mill and city of Arles with water in the first century A.D. Analysis of currently standing arches implies that Roman engineers may have r...
An embedded FBG strain sensor used in the dry-type air-core reactor health monitoring

In order to achieve long-term health monitoring for the dry air core reactor,we propose a suitable embedded fiber Bragg grating(FBG)strain sensor used in strong electromagnetic environment.Simple structure and anti-electromagnetic interference of the strain sensor can be directly buried in the dry air core reactor encapsulation.Two FBG strain sensors and one temperature compensated FBG sensor are embedded in the dry air core reactor encapsulation at the same time in the production process of encapsulation,where two FBG strain sensors are laid in the axial and radial directions,respectively.Dry type air core reactor temperature experiment results show that the encapsulation temperature rises with the growth of power-on time and the axial strain and radial strain of 35 kV dry type air core reactor encapsulation increase in the opposite directions.About five hours later,encapsulation strain is stabilized,and at this time,the axial strain is about-3200μe,while the radial strain is about-4100μe.The embedded FBG strain sensor is stable and reliable,and the health monitoring of 35 kV dry type air core reactor under extreme environmental can be achieved.
Single-particle Cryo-EM data collected on a 300-kV liquid helium-cooled electron cryomicroscope

Both liquid nitrogen and liquid helium can be used as cryogens to keep biological specimens in their frozen hydrated state in an electron cryomicroscope.Here we have analyzed two sets of biological single-particle image data collected in a JEOL 300-kV electron cryomicroscope with the specimens kept at liquid helium temperature 4 K.The first dataset was the epsilon 15 bacteriophage recorded on a Gatan Ultrascan 4 k×4 k charged-coupled device(CCD).The second dataset was the P22 bacteriophage recorded on Kodak SO-163 photographic film.Both data contain detectable signal to at least 5～6 ! as judged from the incoherently averaged Fourier transform(FT)of the boxed-out particle images.The data quality of both datasets was further quantified by the experimental B-factor,which describes the overall Fourier amplitude decay for the FT of the boxed-out particle images from each CCD frame or electron micrograph.These analyses suggest that the liquid helium-cooled electron cryomicroscope can yield single-particle image data suitable for high resolution reconstruction.
Morphological Observations on the Epithelium of the Developing Urinary Bladder of the Mouse and Rat

Bladders from fetal and neonatal BALB/cStCrlfC3H/Nctr mice and Sprague-Dawley rats were studied to establish the sequence of events in their morphological development by using scanning electron, transmission electron and light microscopy. On fetal day 18 or 19 the epithelium from the mouse and the rat displayed 2 or 3 distinct cell layers. With transmission electron microscopy a star-like contraction of the cell surface of the mouse bladder occurred which was not seen in the developing rat bladder. In both the mouse and the rat, some of the superficial cells sloughed between fetal day 18 or 19 and the day of birth. On the day of birth, the epithelium was composed of only 2 layers. The nuclei of both the superficial and basal layers contained prominent euchromatin, and mitotic figures were often present in the basal layer. By the 5th postnatal day, some of the superficial cells contained autophagic vacuoles, and the epithelium was still 2 cell layers thick. One week after birth the epithelium consisted of 2 to 3 cell layers. Three weeks after birth the epithelium was 3 cell layers thick and appeared as the adult pattern with both transmission and scanning electron microscopy. The study demonstrated that the fetal and neonatal mouse and rat urinary bladders undergo a series of rapid developmental changes and suggest that the fetal and neonatal urinary bladder may be a target organ susceptible to toxic insult.
A Generalized Recurrent Neural Network for Matrix Inversion

Matrix inversion deals with computing the inverse matrix A-1 of a given n ×n nonsingular matrix A, which has been widely used in a variety of applications such as control, robotics, and signal processing. This paper presents a generalized recurrent neural network for matrix inversion. The generalized recurrent neural network can use any monotone nondecreasing activation functions and its steady states are guaranteed to present the inverse matrix A-1.
Inhibition of NOS enhances pulmonary vascular changes in stroke-prone spontaneously hypertensive rats.

To determine the effects of chronic nitric oxide (NO) blockade on the pulmonary vasculature, 58-day-old spontaneously hypertensive rats of the stroke-prone substrain (SHRSP) and Wistar-Kyoto rats (...
Introduction to Integral Transforms

This note is the summary of a series of lectures presented for a number of years by the author to graduate students interested in Mathematical Modeling in Biology. Its aim is essentially practical; proofs are given when they help understanding the essence of a problem, otherwise the approach is mostly intuitive. The operational calculus is presented from an algebraic point of view; starting from the convolution integral, the extension from functions to operators is defined as analogous to the extension from natural numbers to rational numbers. Laplace and Fourier transforms are presented as special cases. The note concludes showing the connection between Fourier transforms and Fourier series.
Isoniazid metabolism and hepatotoxicity

Isoniazid (INH) is highly effective for the management of tuberculosis. However, it can cause liver injury and even liver failure. INH metabolism has been thought to be associated with INH-induced liver injury. This review summarized the metabolic pathways of INH and discussed their associations with INH-induced liver injury.
The Biochemistry of Single Nerve Cell Bodies

There is no question that functional specificity in the brain is largely centered in the neuron and its processes. It is also highly probable that the structural and functional informational content of the brain resides mainly in specific chemical differences among cells. There is a considerable body of evidence that metabolic, chemical, and immunological differences exist among different neuronal types within any individual. Even superficial observations of differential susceptibility to viral invasion or to toxic or anoxic damage force one to assume such specificity. Except for rudimentary knowledge of differences in the nature of the chemical transmitters produced and the enzyme systems concerned with their metabolism, relatively little is known about the chemistry of neuronal specialization.
Changes in household food insecurity are related to changes in BMI and diet quality among Michigan Head Start preschoolers in a sex-specific manner.

Children living in households that have recently become food insecure may be particularly vulnerable to adverse weight and dietary changes, but longitudinal studies examining these associations are lacking. Using data from 501 Head Start preschoolers from Michigan (48% male) who were followed during one school year as a part of a randomized obesity prevention trial, we examined changes in children's adiposity indices and dietary quality according to changes in household food insecurity. Household food insecurity change status was categorized as persistently food secure, became food secure, persistently food insecure, or became food insecure. Linear mixed effects models were used to estimate relative changes in BMI-for-age z scores (BAZ), triceps skinfolds-for-age z scores (TAZ), or diet quality (assessed with the 2010 Healthy Eating Index) over the school year according to food insecurity category. We found that girls from households that became food insecure over the year had a 0.21 unit higher gain in BAZ than girls from households that were persistently food secure, after adjustment for potential confounders (95% CI 0.02 to 0.39, P = 0.03). Girls from households that became food secure had improvements in dietary quality over the year compared to girls from persistently food insecure households (adjusted difference in Healthy Eating Index score change = 9.1 points; 95% CI 3.0 to 15.0; p = 0.003). There were no statistically significant associations with changes in TAZ. Among boys, there were no associations between changes in household food insecurity and changes in BAZ, TAZ, or dietary quality. In summary, we found that BMI and diet quality changes of Head Start preschool girls were correlated with short-term changes in household food insecurity. Continued research efforts should focus on identifying the most effective ways to promote the health of children in food insecure households, especially those who may have recently transitioned or are transitioning into food insecurity.
Comparative study of two chemical protocols for creating white spot lesions: An in vitro FluoreCam evaluation

Aim The aim of the present study was to compare the effectiveness and practicality of two commonly-used protocols for white spot lesion creation. Methods Sound posterior human teeth were sectioned into halves and randomly allocated into two groups (n=20). Using the FluoreCam system, the enamel surfaces were imaged under standardized conditions, and baseline data (area, intensity, and impact) were recorded. Specimens were covered with an acid-resistant polish, leaving a 2×6-mm enamel window. Group 1 was immersed in Queiroz solution (64 hours/37°C/pH5 with agitation); Group 2 was immersed in Buskes solution (14 days/37°C/pH5 with agitation). The specimens then were imaged again. Within-group changes that occurred over time were evaluated using the Wilcoxon signed-rank test. Between-group differences were analyzed using the Mann-Whitney U-test. Polarized light microscopy (PLM) was used to calculate the mean lesion depth of representative specimens. Results Each protocol showed significant changes in the surface area, intensity and impact of demineralization over time (P<.05). There were no statistically-significant differences (P=.53, P=.2, P=.74) between the two groups. PLM showed that the mean lesion depths of representative specimens were 51.4 and 73.0 μm for groups 1 and 2, respectively. Conclusions While both protocols produce similar amounts of demineralization, the Queiroz solution is more practical, as it requires less time.
Phosphoranimines containing cationic N-imidazolinium moieties

Abstract Three new monomeric phosphoranimines (PAs; R′ N PR3) were synthesized by the Staudinger route using 2-azido-1,3-dimethylimidazolinium hexafluorophosphate [ADMImPF] and various phosphines to form their respective PA salts of triphenylphosphine (1), tri(n-octyl)phosphine (2), and tris(2,2,2-trifluoroethoxy)phosphite (3). These PA salts have a cationic imidazolinium moiety attached to nitrogen. Interestingly, 2 is a room temperature ionic liquid (RTIL) with a melting point around −5 °C and a viscosity of 740cP at 25.5 °C. 1 and 2 show stability to moisture exposure and atmosphere for weeks whereas 3 is not stable toward atmospheric moisture undergoing decomposition to form 2-amino-1,3-dimethylimidazolinium phosphate (4). Thermal analyses reveal that 1 and 2 are stable to 90 °C under nitrogen, but 3 undergoes degradation by exposure to moisture and/or elevated temperature. All compounds exhibit similar multinuclear NMR chemical shifts as compared to their corresponding phosphine oxide counterparts. However, their respective X-ray structure determinations indicate that 2 has an open structure with the octyl groups that avoid the ionic charges, whereas 1 and 3 have tighter structural packing of the hexafluorophosphate to their pendant groups.