cssi/SciSciGPT-SciSciNet huggingface dataset:
Teaching Statistics to Engineers: Learning from Experiential Data

The purpose of the work is to claim that engineers can be motivated to study statistical concepts by using the applications in their experience connected with Statistical ideas. The main idea is to choose a data from the manufacturing factility (for example, output from CMM machine) and explain that even if the parts used do not meet exact specifications they are used in production. By graphing the data one can show that the error is random but follows a distribution, that is, there is regularily in the data in statistical sense. As the error distribution is continuous, we advocate that the concept of randomness be introducted starting with continuous random variables with probabilities connected with areas under the density. The discrete random variables are then introduced in terms of decision connected with size of the errors before generalizing to abstract concept of probability. Using software, they can then be motivated to study statistical analysis of the data they encounter and the use of this analysis to make engineering and management decisions.
Cardiovascular studies on copper-deficient swine. XI. Mucopolysaccharides and the mechanical properties of the aorta.

Abstract The effects of incubating thoracic aorta from control and copper-deficient swine with mucopolysaccharides were studied. Although the enzymes removed alcian blue staining material from the tissues, there was no effect on aortic tensile strength and the amounts of polysaccharides liberated into the incubating medium were not significantly higher than those present in the buffer controls. There were no behavioral differences between aortas from copper-deficient and control animals. The relationship between acid mucopolysaccharides do not contribute significantly to the tensile strength of aorta, and are not directly involved in the aortic fragility of copper deficiency.
3D-mapping of phosphocreatine concentration in the human calf muscle at 7 T: comparison to 3 T.

Purpose The development and implementation of a spectrally selective 3D-Turbo Spin Echo sequence for quantitative mapping of phosphocreatine (PCr) concentration in different muscles of the lower leg of healthy volunteers both at 3 T and 7 T. Methods Nine healthy volunteers were recruited, all of whom where scanned at 3 T and 7 T. Three dimensional PCr concentration maps were obtained after images were corrected for B1 inhomogeneities, T1 relaxation weighting, and partial volume of fatty tissue in the muscles. Two volunteers performed plantar flexions inside the magnet, and the oxidative capacity of their muscles was estimated. Results Three dimensional PCr concentration maps were obtained, with full muscle coverage and nominal voxel size of 0.52 mL at both fields. At 7 T a 2.7-fold increase of signal-to-noise ratio was achieved compared to 3 T. Conclusion Imaging 31P metabolites at 7 T allowed for significant increase in signal to noise ratio compared to imaging at 3 T, while quantification of the PCr concentration remained unaffected. The importance of such an increase in signal-to-noise ratio is 2-fold, first higher resolution images with reduced partial volume effects can be acquired, and second multiple measurements such as dynamic imaging of PCr post-exercise, 31P magnetization transfer, or other 1H measurements, can be acquired in a single imaging session. Magn Reson Med 70:1619–1625, 2013. © 2013 Wiley Periodicals, Inc.
Enhancing concept learning: the simulation design experience

Druckman and Ebner carefully review a large number of studies which conclude that simulations (in all fields, not just negotiation) typically fail to live up to their promise. One quirk of the studies, however, drew their particular interest and inspired their own research: it seemed that students who designed simulations learned more than those who participated in them. Druckman and Ebner use this clue to develop a different kind of negotiation simulation – one in which the student plays the role of a teacher, and designs an exercise.
Decriminalizing Hacktivism: Finding Space for Free Speech Protests on the Internet

Over the last decade there has been a large increase in the number of cyber attacks on U.S. companies and all trends indicate that these attacks will only increase in number and severity over the next several years. These attacks cost the U.S. economy billions of dollars and thousands of jobs annually. However, there are many types of cyber attacks. Some attacks are cyber terrorism and are done solely to destroy or impede U.S. infrastructure. Some attacks are espionage oriented and are more concerned with quietly stealing lots of secret and proprietary information rather than public disruptions of and damage to U.S. infrastructure. However, there are also a number of cyber attacks that are designed solely to send public messages as forms of political and social protest rather than cause lasting damage to the targets of the attack. All of these attacks have vastly different motivations and purposes. Yet U.S. policymakers, in their rush to address these serious threats to the U.S. economy, have often crafted legislation that sweeps too broadly and criminalizes modern protests movements that are analogous to protest activities that have traditionally received protection under the first amendment of the constitution. This paper surveys several of the major federal laws governing cyber crimes and argues that online hacker protests, known as “hacktivism”, should be recognized as different from other types of cyber attacks and given the protections they deserve under the First Amendment because the internet is the modern equivalent of public forums where protest activities have generally received the highest protections. The data also suggest that given the ever growing number of cyber attacks in spite of severe criminal penalties federal cybercrime laws are ineffective at preventing this type of cyber protest anyway. The paper further argues that granting hacktivism protection from criminal prosecution is acceptable because targets of these cyber attacks are still free to pursue redress on their own under tort remedies. The evidence also shows that responsible firms can greatly reduce their losses from any potential attack simply by taking common sense cybersecurity measures. Additionally, the growth of firms specializing in cyber forensics makes this a more realistic option for victims than it was even a few years ago. The paper concludes by arguing that because of the First Amendment the character of U.S. law has always been willing to accept higher levels of risk and economic disruption due to protest activities and it should do again in the new public commons of cyberspace.
Time Course of Purine Nucleoside Phosphorylase Occurrence in Sporulation of Bacillus cereus

Purine nucleoside phosphorylase (EC 2.4.2.1) from Bacillus cereus T was examined at hourly intervals during growth and sporulation. The enzyme has maximal activity in extracts prepared from cells during stages I and II. The activity during exponential growth is only 6.6% of the maximum and that in free spores is only 3.3%. Conservation of the purine nucleoside phosphorylase during sporulation is apparent as shown by the gradual increase in heat resistance.
The Connection Between Parallel Electric Fields and Ion Acceleration in Astrophysical Plasmas

It is now well-established that magnetic field-aligned electric fields play a significant role in particle dynamics in the auroral region, and strong evidence for similar electric fields exists in other astrophysical plasmas. However, ionospheric ion outflow in the auroral region is primarily associated with downward or oscillating parallel electric fields rather than upward electric fields. The reason for the discrepancy is that waves which produce transverse ion heating are found in regions of parallel electric fields, and downward electric fields enhance the heating by trapping ions. We discuss a model for the distribution of parallel electric fields along auroral flux tubes, as well as implications for ion heating in other astrophysical plasmas including the solar corona.
Impact response and injury of the pelvis

On presente la reponse cinematique du pelvis pendant et apres l'impact pour indiquer les similarites et les differences de reponse du pelvis pour divers niveaux de charge. Alors que les donnees de reponse de l'impact ne peuvent pas prescrire un niveau de tolerance pour le pelvis, ils indiquent tout de meme des variables qui peuvent etre considerees et quelques problemes potentiels en developpant un critere de blessures precis
Model-Free Search for Extra-Framework Cations in Zeolites Using Powder Diffraction

The crystal framework of zeolites can usually be determined using prior chemical knowledge and traditional crystallographic techniques using direct methods or Patterson syntheses. However, a more difficult problem often occurs in the structure refinement stage, namely the location of extra-framework cations, a key-feature of any zeolite catalyst. To find these, the methods currently in use rely heavily on educated guesses, constrained Rietveld refinements and Fourier syntheses. Here, we demonstrate a more objective way of locating these cations from powder diffraction data using a maximum-entropy approach. We have successfully applied this procedure to synchrotron x-ray powder data pertaining to Na-A and Y aluminosilicate zeolites.
Short-living excited states in pristine and C60-doped disubstituted polyacetylene

Abstract We study the primary photoexcitations in pristine and C 60 -doped doubly phenyl-substituted polyacetylene films using femtosecond pump–probe spectroscopy. We show that the ultrafast relaxation occurs via branching between two different relaxation pathways. In pristine films mobile emissive odd-parity (1B u ) excitons radiatively recombine in the ionic relaxation channel. In C 60 -doped films 1B u excitons dissociate and give rise to polarons on 10-ps time scale. Non-emissive even-parity excitons, which are primary excitations in the covalent relaxation channel, give rise to immobile topological solitons. The dynamics of photoexcitations in covalent channel are almost unaffected by C 60 doping.
Visualization of drug-nucleic acid interactions at atomic resolution. IV. Structure of an aminoacridine--dinucleoside monophosphate crystalline complex, 9-aminoacridine--5-iodocytidylyl (3'--5') guanosine.

9-Aminoacridine forms a crystalline complex with the dinucleoside monophosphate, 5-iodocytidylyl(3′–5′)guanosine (iodoCpG). These crystals are monoclinic, space group P21 with a = 13.98 A, b = 30.58 A, c = 22.47 A and β = 113.9 °. The structure has been solved to atomic resolution by Patterson and Fourier methods, and refined by a combination of Fourier and sum-function Fourier methods. The asymmetric unit contains four 9-aminoacridine molecules, four iodoCpG molecules and 21 water molecules, a total of 245 atoms. 9-Aminoacridine demonstrates two different intercalative binding modes and, along with these, two slightly different intercalative geometries in this model system. The first of these is very nearly symmetric, the 9-amino group lying in the narrow groove of the intercalated base-paired nucleotide structure. The second shows grossly asymmetric binding to the dinucleotide, the 9-amino group lying in the wide groove of the structure. Associated with these two different intercalative binding modes is a difference in geometries in the structures. Although both structures demonstrate C3′ endo (3′–5′) C2′ endo mixed sugar puckering patterns (i.e. both cytidine residues have C3′ endo sugar conformations, while both guanosine residues have C2′ endo sugar conformations), with corresponding twist angles between base-pairs of about 10 °, they differ in the magnitude of the helical screw axis dislocation accompanying intercalation (Sobell et al., 1977a,b). In the pseudosymmetric intercalative structure, this value is about +0.5 A, whereas in the asymmetric intercalative structure this value is about +2.7 A. These conformational differences can be best described as a “sliding” of base-pairs on the intercalated acridine molecule. Although the pseudosymmetric intercalative structure can be used in 9-aminoacridine-DNA binding, the asymmetric intercalative structure cannot since this poses stereochemical difficulties in connecting neighboring sugar-phosphate chains to the intercalated dinucleotide. It is possible, however, that the asymmetric binding mode is related to the mechanism of 9-aminoacridine-induced frameshift mutagenesis (Sakore et al., 1977), and we discuss this possibility here in further detail.
Opening minds: cultural change with the introduction of open-source collaboration methods

As open-source software becomes accepted worldwide, open-source collaboration and development methods are also gaining greater momentum. Collaboration based on the open-source paradigm is increasingly being used to improve multisite development and teamwork inside companies. Drawing on experience in projects for improving multisite collaboration, this paper explains how we evaluate communication and collaboration problems, assess obstacles to change, and facilitate the change by introducing employees to the benefits of the collaborative model over traditional development projects in a workshop setting. This method has proven to be a valuable “mind-opener” and helps identify specific obstacles that need to be addressed as part of the introduction of open-source development and collaboration methods. The paper concludes with lessons learned for facilitating the introduction of these methods in an organization.
"So-called Orthodoxy": The History of an Unwanted Label

One of the stranger aspects of the polemical arguments between German-Jewish reformers and traditionalists that took place in the middle of the nineteenth century is their odd agreement on the singular inappropriateness of the term ‘‘orthodox’’—literally, ‘‘right believing’’—to describe traditional Jews. Instead, they disagreed about who was to blame for the use of this label, with each group attributing its origin to the other. German-Jewish reformers regularly referred to their traditionalist opponents not merely as orthodox, but as ‘‘der sogenannte Orthodoxen’’ (‘‘the so-called orthodox’’), or ‘‘die vorgebliche Orthodoxie’’ (‘‘the ostensibly orthodox’’), or ‘‘die erheuchelte Orthodoxdie (‘‘the sham orthodox’’). In this way, reformers both disparaged the legitimacy of the description of traditionalists as right believing, as well as at the same time implying that this was how traditionalists referred to themselves. The leading spokesman for the traditionalists in Germany, Rabbi Samson Raphael Hirsch, responded to these attacks in 1854, stating that ‘‘it is not ‘orthodox’ Jews who first introduced the term ‘orthodoxy’ into Judaism,’’ but, in fact, ‘‘it was the modern ‘progressive’ Jews who first applied the epithet to their ‘old-style’ backward brethren to distinguish them in a derogatory sense.’’ Hirsch noted that traditionalists resented the use of the term ‘‘orthodox,’’ and ‘‘rightly so.’’ Yet, Hirsch himself used the term ‘‘orthodox’’ to describe traditional Jews, though he preferred the label ‘‘gesetztreu’’ (literally ‘‘true to the law’’ or ‘‘Torah true’’). Perhaps the oddest aspect of this debate was over whether the great German-Jewish philosopher and advocate of the Enlightenment, Moses Mendelssohn, was really orthodox. Rabbi Leopold Stein, the leader of the Franfurt reform community, argued that Mendelssohn opposed and was opposed by orthodox Jews, and that therefore by implication he really was a reformer, but Hirsch, quoting passages from Mendelssohn’s Jerusalem, showed he had remained committed to the observance of traditional Jewish law, and that therefore by implication he really was orthodox.
Observed and Reported Supportive Coparenting as Predictors of Infant-Mother and Infant-Father Attachment Security

This study examined associations between supportive coparenting and infant-mother and infant-father attachment security. Observed and parent-reported coparenting, and observed maternal and paternal sensitivity were assessed in a sample of 68 families with 3.5-month-old infants. Infant-mother and infant-father attachment security were assessed in the Strange Situation Procedure (Ainsworth, Blehar, Waters, & Wall, 1978) at 12 and 13 months of age, respectively. Observed and reported supportive coparenting were associated with greater attachment security in the infant-father, but not the infant-mother, attachment relationship. The link between observed coparenting and infant-father attachment remained after accounting for paternal sensitivity. Furthermore, child gender moderated some associations between coparenting and infant-parent attachment security. Among families with boys, observed and reported supportive coparenting was related to greater infant-mother and infant-father attachment security, respectively. Coparenting was unrelated to infant-mother or infant-father attachment security among families with girls. Results highlight a possible link between the coparental and father-child relationships and the need to consider both parent and child gender when examining associations between family functioning and attachment.
Comparison of Risk-Adjusted 30-Day Postoperative Mortality and Morbidity in Department of Veterans Affairs Hospitals and Selected University Medical Centers: General Surgical Operations in Men

Background We used data from the Patient Safety in Surgery Study to compare patient populations, operative characteristics, and unadjusted and risk-adjusted 30-day postoperative mortality and morbidity between the Veterans Affairs (VA) (n = 94,098) and private (n = 18,399) sectors for general surgery operations in men. Study Design This is a prospective cohort study. Trained nurses collected preoperative risk factors, operative variables, and 30-day postoperative mortality and morbidity outcomes in male patients undergoing major general surgery operations at 128 VA medical centers and 14 university medical centers from October 1, 2001, to September 30, 2004. Multiple logistic regression analysis was used to identify preoperative predictors of postoperative mortality and morbidity. An indicator variable for VA versus private-sector medical center was added to the model to determine if risk-adjusted outcomes were significantly different in the two systems. Results The unadjusted 30-day mortality rate was higher in the VA compared with the private sector (2.62% versus 2.03%, p=0.0002); unadjusted morbidity rate was lower in the VA compared with the private sector (12.24% versus 13.99%, p Conclusions In general surgery operations in men, the VA appeared to have a higher risk-adjusted mortality rate compared with the private sector, but differences in mortality ascertainment in the two sectors might account for some of this effect. The higher mortality in the VA could be the result of higher mortality in the less common, more complex operations. There is a trend toward lower risk-adjusted morbidity in the VA compared with the private sector.
The theoretical model for the annular jet instability—Revisited

The theoretical model of Lee and Wang (1986) for the instability of an annular jet, in which the jet's liquid layer is treated as a thin liquid sheet, is examined. It is suggested that the model should be altered so that when the envelope is closing its bottleneck during collapse, the new envelope experiences a sharp pressure pulse from its gaseous core, reversing the normal velocity of the sheet enough to maintain continuous constant gas flow. Using this improved version of the model, it is shown that if the liquid velocity is high enough and the gas velocity is greater than the liquid velocity, the bubble-formation frequency varies linearly with the difference between the two velocities, but not with their individual values.
Coiled-coil packing in spermine-induced tropomyosin crystals a comparative study of three forms

Abstract Electron microscope images of highly ordered spermine-induced microcrystals of tropomyosin have been analyzed to determine the packing of the molecular filaments. Negatively stained microcrystals terminate in a distinctive “double fringe”, which reveals the location of the molecular ends. This information, together with the symmetry of the structure in projection, shows that the microcrystals can be accounted for by a packing scheme of four layers of molecules in the unit cell. Knowing the position of the symmetry elements relating the layers then allows the three-dimensional space group of the microcrystals to be established as C2221. Using cryo-electron microscopy and simulation studies, the run of the filaments and their packing in the C2221 form have been shown to be related to those in the spermine-induced C2 crystal of tropomyosin whose structure has been solved to 9 A by X-ray crystallography. This result allows us to infer the location of the molecular ends in the C2 crystal as well, and this inference has been confirmed by analysis of thin sections of the C2 crystal. The C2221 microcrystal has also been shown to be closely related to the classical divalent cation tropomyosin paracystal. Based on knowledge of the molecular packing in the divalent cation paracrystal, the polarity of the molecules has been deduced in the other two crystal forms. The tropomyosin filament packing in all these forms may be accounted for by coiled-coil close packing and specific cationic bridging of negatively charged zones on the molecule. Taken together the results reveal a hierarchy of interactions in these close-packed crystalline forms, whose principles may apply to the packing in other fibrous proteins. This study also shows the usefulness of co-ordinating results from cryoelectron microscopy with negative staining in the structure analysis of such ordered arrays, and how these findings can complement the results of low resolution X-ray crystallographic studies.
Appropriation possibilities in a simple exchange economy

Abstract Appropriation possibilities cause relative price, trade volume, and welfare to vary considerably from the predictions of the standard Edgeworth box. When attack effectiveness is low, a tariff designed to punish a nation’s piracy effort expands trade volume, welfare, and security of property. When attack effectiveness is high, the anti-piracy tariff causes the piracy rate to increase and the security of property to fall.
A Capacity Building Program to Promote CBPR Partnerships between Academic Researchers and Community Members

Introduction: Community-based participatory research (CBPR) adds community perspectives to research and aids translational research aims. There is a need for increased capacity in CBPR but few models exist for how to support the development of community/university partnerships. Objective: Evaluate an approach to promote nascent CBPR partnerships. Methods: Design was a mixed–methods evaluation using interviews, process notes, and open- and close-ended survey questions. We trained 10 community scholars, matched them with prepared researchers to form seven partnerships, and supported their developing partnerships. Sequential mixed–methods analysis assessed research and partnership processes and identified integrated themes. Results: Four of seven partnerships were funded within 15 months; all self-reported their partnerships as successful. Themes were: (1) motivators contributed to partnership development and resiliency; (2) partners took on responsibilities that used individuals’ strengths; (3) partners grappled with communication, decision making, and power dynamics; and (4) community–university infrastructure was essential to partnership development. Conclusions: This program for developing nascent partnerships between academicians and community members may guide others in increasing capacity for CBPR. Clin Trans Sci 2011; Volume 4: 428–433
Magnetic properties of rare earth-cobalt phases R 5 Co 19

Phases with the stoichiometry R 5 Co 19 have been observed in the rare earth-cobalt systems with R = La, Ce, Pr, and Nd. These phases may play a significant role in the development of coercive force in RCo 5 -based permanent magnets containing the light rare earths, particularly mischmetal. The present paper reports Curie temperatures, saturation magnetizations, and the results of anisotropy field measurements made on alloy powders of these phases.
BLUP Genotype Imputation for Case-Control Association Testing with Related Individuals and Missing Data

We consider the problem of case-control association testing in samples that contain related individuals, where we assume the pedigree structure is known. Typically, for each marker tested, some individuals will have missing genotype data. The MQLS method has been proposed for association testing in this situation. We show that the MQLS method is equivalent to an approach in which missing genotypes are imputed using the best linear unbiased predictor (BLUP) based on relatives' genotype data. Viewed this way, the MQLS exactly corrects for the imputation error and for the extra correlation due to imputation. We also investigate the amount of additional power for detecting association that is provided by this BLUP imputation approach.
Effects of the addition of potassium or sodium, but not calcium, to prepartum rations on milk fever in dairy cows

The effects of prepartum dietary concentrations of K, Na, and Ca on the incidence of periparturient hypocalcemia or milk fever was determined for older (> or = 4th lactation) Jersey cows. Cows were fed one of six diets differing in K and Ca contents. In addition, the effect of dietary Na (tested only at the high concentration of dietary Ca, and low concentration of dietary K) was examined. Treatments were arranged in an incomplete 2 x 4 factorial design; dietary Ca (0.5 or 1.5%) and dietary strong cations (1.1, 2.1, and 3.1% K or 1.3% Na) were the main effects. Dietary Ca did not significantly affect the incidence of milk fever of the degree of hypocalcemia experienced by the cows. Milk fever occurred in 2 of 20 cows that were fed the prepartum diet containing 1.1% K and 0.12% Na. Increasing dietary K to 2.1 or 3.1% increased the incidence of milk fever to 10 of 20 cows and 11 of 23 cows, respectively. Increasing dietary Na to 1.3% in the diet containing 1.5% Ca induced milk fever in 5 of 8 cows. Addition of strong cations to the prepartum diet increased blood and urine pH and reduced plasma hydroxyproline concentrations, suggesting that bone resorption of Ca is inhibited in cows fed high K or high Na diets as a result of metabolic alkalosis. These data demonstrated that dietary Ca concentration is not a major risk factor for milk fever and that dietary strong cations, especially K, induce metabolic alkalosis in the prepartum dairy cow, which reduces the ability of the cow to maintain Ca homeostasis.
Longitudinal data model selection

In longitudinal data with correlated errors, we apply the likelihood and residual likelihood approaches to obtain the corrected Akaike information criterion (AICc) and the residual information criterion (RIC), respectively. Simulation studies show that AICc outperforms the Akaike information criterion (AIC) when the numbers of subjects and repeated observations are small, and RIC is superior to the Bayesian information criterion (BIC) when the signal-to-noise ratio is moderate to large. We illustrate the practical use of these selection criteria with an empirical example for modeling the serum cholesterol measured at six time occasions.
Determination of amniotic fluid volume in twin pregnancies: ultrasonographic evaluation versus operator estimation.

Abstract Objective: We sought to determine the accuracy of amniotic fluid volume estimation (visually) in diamniotic twin pregnancy versus ultrasonography techniques. Study Design: In this prospective study the volume of each sac in 23 sets of diamniotic twin pregnancies was subjectively and objectively estimated by a second-year obstetric resident, nurse sonographer, maternal-fetal medicine fellow, and maternal-fetal medicine staff. The actual volume was confirmed by amniocentesis and a dye-dilution technique. Results: There was no difference in the total number of correct estimates of volume by level of operator experience ( P =.98), ultrasonography technique ( P =.87), or combined subjective versus objective correct estimates ( P =.87). Identification of low volume was not different among the four evaluators ( P =.48), but the percentage of correct estimates was poor (7%-29%). The 2-diameter pocket was a better predictor of oligohydramnios (57%) than the amniotic fluid index or the largest vertical pocket (12.5%; P =.002). Conclusion: The extremes of volume (low or high) are poorly identified by the subjective or objective assessment of volume. (Am J Obstet Gynecol 2000;182:1606-9.)
Early-Life Exposure to Testosterone Programs the Hypothalamic Melanocortin System

In mammals, males consume more food, which is considered a masculinized behavior, but the underlying mechanism of this sex-specific feeding behavior is unknown. In mice, neonatal testosterone (NT) is critical to masculinize the developing brain, leading to sex differences in reproductive physiology. The proopiomelanocortin (POMC) neurons of the hypothalamic arcuate nucleus (ARC) are critical to suppress energy intake and POMC innervation of hypothalamic feeding circuits develops to a large extent neonatally. We hypothesized that NT programs the masculinization of energy intake by programming POMC neurons. We tested this hypothesis by comparing control females and control males (CMs) with female mice neonatally androgenized with testosterone (NTFs). We show that increased food intake in CMs is associated with reduced POMC expression and decreased intensity of neuronal projections from POMC neurons within the ARC compared with control females. We found that NTFs display a masculinized energy intake and ARC POMC expression and innervation as observed in CMs, which can be mimicked by neonatal exposure to the androgen receptor agonist dihydrotestosterone (DHT). NTFs also exhibit hyperleptinemia and a decreased ability of leptin to up-regulate POMC, suppress food intake, and prevent adipose tissue accumulation, independent of signal transducer and activator of transcription 3. However, this leptin resistance is specific to NTFs, is not a consequence of masculinization, and is reproduced by neonatal exposure to estrogen but not DHT. Thus, NT programs a sexual differentiation of POMC neurons in female mice via DHT but also predisposes to leptin resistance and obesity in an estrogen-dependent manner.
Damage-tolerant laminated composites in thermal shock

Alumina is very susceptible to thermal shock which often leads to catastrophic failure. The addition of tape-cast nickel layers to laminated alumina can increase its tolerance to damage induced during thermal shock. The fracture behaviour after thermal shock of laminated composites showed non-catastrophic failure during loading at room temperature. The retained strength of the laminates was determined for a wide range of quenching-temperature differences (δT= 150–1200‡C). The retained strength and critical quenching-temperature difference, δT c, of the laminated composites were a significant improvement over the values for the respective monolithic alumina. This improvement in behaviour can be related to the compressive residual stress in the alumina layers and ductile-layer crack blunting.
Timing of appearance of late oligodendrocyte progenitors coincides with enhanced susceptibility of preterm rabbit cerebral white matter to hypoxia-ischemia

Emerging evidence supports that premature infants are susceptible to both cerebral white and gray matter injury. In a fetal rabbit model of placental insufficiency, preterm rabbits at embryonic day 22 (E22) exhibited histologic evidence of gray matter injury but minimal white matter injury after global hypoxia-ischemia (H-I). We hypothesized that the dissociation between susceptibility to gray and white matter injury at E22 was related to the timing of appearance of late oligodendrocyte progenitors (preOLs) that are particularly vulnerable in preterm human white matter lesions. During normal rabbit oligodendrocyte (OL) lineage progression, early OL progenitors predominated at E22. PreOL density increased between E24 and E25 in major forebrain white matter tracts. After H-I at E22 and E25, we observed a similar magnitude of cerebral H-I, assessed by cortical microvascular blood flow, and gray matter injury, assessed by caspase activation. However, the increased preOL density at E25 was accompanied by a significant increase in acute white matter injury after H-I that coincided with enhanced preOL degeneration. At E29, significant white matter atrophy developed after H-I at E25 but not E22. Thus, the timing of appearance of preOLs coincided with onset of a developmental window of enhanced white but not gray matter susceptibility to H-I.
Comparison of surface mechanical properties among linear and star polystyrenes: Surface softening and stiffening at different temperatures

Abstract In a previous study, we reported both surface softening and stiffening for poly(α-methylstyrene) (PαMS) over a temperature range from room temperature to 21 °C above the glass transition temperature ( T g ) using the spontaneous particle embedment technique. In the present study, we have explored the surface mechanical responses of a linear polystyrene (PS), a 3-arm star PS, and an 8-arm star PS emphasizing the range of temperature from T g −10 °C to T g +10 °C, similar to that in which the prior study had shown a transition from surface softening (increased mobility) to stiffening (decreased mobility). We used atomic force microscopy for particle embedment depth estimation and the isochronal form of the Lee and Radok (LR) model for surface compliance determination. We observed both surface softening and stiffening for the linear PS and 3-arm star PS for the studied temperature range. However, surface softening was observed at all temperatures in this study for the 8-arm star PS. The surface compliance results for the different PS molecular architectures are compared with those for the linear PαMS from the previous study.
A Continuum Approach to Permeation With Interfacial Leakage: A Space Seal Approach

Prior analyses in elastomer space-seals thrived on the assumption that mass flow over/through a seal was due to permeation. In fact, the state-of-the-art space-seal leakage prediction method relies on this assumption. Well-documented efforts have shown that the aforementioned prediction method is versatile in its ability to predict leak rates in nominal operational conditions. Its merits, however, fall short in the application of low seal contact loading and in applications with substantial space environmental exposure (e.g., ultraviolet radiation, atomic oxygen). In response to this shortfall, a unique method and analysis was recently developed to parse total leakage into interfacial leakage and permeation, with the intent of capturing the effects of surficial degradation; results highlighted that while permeation dominated interfacial leakage for high contact seal loading, the interfacial component was not negligible. Furthermore, the interfacial component was shown to dominate permeation for low contact pressure, as would be the case with a faulty docking mechanism. Presented herein is a novel continuum approach to seal leakage that retains the compressible permeation approach previously developed and enhances the overall fidelity by incorporating interfacial leakage with entrainment terms which describe the movement of mass orthogonal to the seal-counter face boundary (i.e., mass transfer from the elastomer to the interfacial zone). Integral to the proposed model, the interfacial leakage component is a function of seal contact pressure, pressure gradient, and, ultimately, space environmental exposure. Also presented is an application of the model to a candidate, elastomer space seal. Results showed an improved prediction and provide a measure of verification and validation to the proposed seal leakage model.Copyright © 2014 by ASME
Voltage tunable two-color superlattice infrared photodetectors

We present the design and fabrication of voltage tunable two-color superlattice infrared photodetectors (SLIPs), where the detection wavelength switches from the long-wavelength infrared (LWIR) range to the mid-wavelength infrared (MWIR) range upon reversing the polarity of applied bias. The photoactive region of these detectors contains multiple periods of two distinct short-period SLs that are designed for MWIR and LWIR detection. The voltage tunable operation is achieved by using two types of thick blocking barriers between adjacent SLs - undoped barriers on one side for low energy electrons and heavily-doped layers on the other side for high energy electrons. We grew two SLIP structures by molecular beam epitaxy. The first one consists of two AlGaAs/GaAs SLs with the detection range switching from the 7-11 μm band to the 4-7 μm range on reversing the bias polarity. The background-limited temperature is 55 and 80 K for LWIR and MWIR detection, respectively. The second structure comprises of strained InGaAs/GaAs/AlGaAs SLs and AlGaAs/GaAs SLs. The detection range of this SLIP changes from the 8-12 μm band to the 3-5 μm band on switching the bias polarity. The background-limited temperature is 70 and 110 K for LWIR and MWIR detection, respectively. This SLIP is the first ever voltage tunable MWIR/LWIR detector with performance comparable to those of one-color quantum-well infrared detectors designed for the respective wavelength ranges. We also demonstrate that the corrugated light coupling scheme, which enables normal-incidence absorption, is suitable for the two-color SLIPs. Since these SLIPs are two-terminal devices, they can be used with the corrugated geometry for the production of low-cost large-area two-color focal plane arrays.
Onset of quantized thermal fluctuations in one-dimensional superconductors

Measurements of the onset of the resistive transition and the current-voltage characteristics of "one-dimensional" single-crystal tin whiskers have been extended to a sensitivity of ${10}^{\ensuremath{-}15}$ V. The thermally activated quantum phase slips proposed by Langer and Ambegaokar have been observed directly and their theory for the voltage, determined by the rate of phase slippage, has been verified together with the modification of the attempt frequency proposed by McCumber and Halperin.
Reactivity of penicillin-induced epileptogenic foci to selective blockade of membrane sodium-potassium ATPase via ouabain.

Abstract Factors governing the onset of cell discharge at experimental seizure foci have received detailed study, but less is known about the basis for slow, spontaneous cyclic seizure activity of experimental and clinical foci. This problem was here approached by studying the reactivity of penicillin-induced interictal discharge to blockade of sodium-potassium-coupled transport. Perfusion of hippocampal foci with ouabain in artificial cerebrospinal fluid yielded a generally triphasic effect on the rate of spontaneous interictal discharge: an initial deceleration or temporary suspension; acute acceleration; then terminal slowing and cessation. The latency of onset of acute acceleration was inversely related to ouabain concentration in the perfusate. An immediate effect of the neuromuscular blocking agents gallamine and tubocurarine on interictal discharge rate was noted with high intravenous doses, as was a long-term effect of smaller doses (typical for experimental immobilization) on the subsequent response to ouabain. The relation of these interictal spike-interval data to transmembrane NaK exchange is discussed, including ion accumulation and electrogenic transport factors. The analogy with cortical spreading depression is considered.
An Undesired Effect of Chemotherapy: GEMCITABINE PROMOTES PANCREATIC CANCER CELL INVASIVENESS THROUGH REACTIVE OXYGEN SPECIES-DEPENDENT, NUCLEAR FACTOR κB- AND HYPOXIA-INDUCIBLE FACTOR 1α-MEDIATED UP-REGULATION OF CXCR4*

Recently, we have shown that CXCL12/CXCR4 signaling plays an important role in gemcitabine resistance of pancreatic cancer (PC) cells. Here, we explored the effect of gemcitabine on this resistance mechanism. Our data demonstrate that gemcitabine induces CXCR4 expression in two PC cell lines (MiaPaCa and Colo357) in a dose- and time-dependent manner. Gemcitabine-induced CXCR4 expression is dependent on reactive oxygen species (ROS) generation because it is abrogated by pretreatment of PC cells with the free radical scavenger N-acetyl-L-cysteine. CXCR4 up-regulation by gemcitabine correlates with time-dependent accumulation of NF-κB and HIF-1α in the nucleus. Enhanced binding of NF-κB and HIF-1α to the CXCR4 promoter is observed in gemcitabine-treated PC cells, whereas their silencing by RNA interference causes suppression of gemcitabine-induced CXCR4 expression. ROS induction upon gemcitabine treatment precedes the nuclear accumulation of NF-κB and HIF-1α, and suppression of ROS diminishes these effects. The effect of ROS on NF-κB and HIF-1α is mediated through activation of ERK1/2 and Akt, and their pharmacological inhibition also suppresses gemcitabine-induced CXCR4 up-regulation. Interestingly, our data demonstrate that nuclear accumulation of NF-κB results from phosphorylation-induced degradation of IκBα, whereas HIF-1α up-regulation is NF-κB-dependent. Lastly, our data demonstrate that gemcitabine-treated PC cells are more motile and exhibit significantly greater invasiveness against a CXCL12 gradient. Together, these findings reinforce the role of CXCL12/CXCR4 signaling in gemcitabine resistance and point toward an unintended and undesired effect of chemotherapy.
A thermal-ablation bioheat model including liquid-to-vapor phase change, pressure- and necrosis-dependent perfusion, and moisture-dependent properties

A new bioheat model is applied to evaluate the use of elevated-temperature thermal therapies for the non-surgical ablation of diseased tissue. The new model is based on the use of the enthalpy method to account for liquid-to-vapor phase change. In addition, the model includes thermophysical property dependence on liquid content and variations of blood perfusion rates dependent on the local necrotic state of the tissue or external pressure applied by the therapy-delivering device. This model is applied here specifically to endometrial ablation for the treatment of menorrhagia. The results of the implementation of the model yielded the depth of tissue necrosis corresponding to a given application of heat at the exposed inner surface of the uterine tissue. These results definitively establish the occurrence of phase change and the complete suppression of perfusion as the major factors governing the necrosis depth. The accounting of moisture-dependent properties had a negligible effect on necrosis.
Clinical prediction rules to optimize cytotoxin testing for Clostridium difficile in hospitalized patients with diarrhea

Background Although routine testing of hospitalized patients with diarrhea for Clostridium difficile cytotoxin has been advocated as a high-yield procedure, the rationale for this practice has been questioned. To target a low-yield subgroup for whom routine testing could be deferred, we derived a clinical decision rule for predicting results of the C difficile cytotoxin assay in hospitalized adults with diarrhea. Methods We hypothesized a priori that two variables, antibiotic use (within 30 days prior to testing) and history of significant diarrhea (new onset of >3 partially formed or watery stools per 24 hour period), would be highly predictive of cytotoxin results, and obtained these data on 480 consecutive patients who underwent diagnostic testing for C difficile at a university hospital and affiliated Veterans Affairs medical center. For more detailed modelling, we recorded symptoms, signs, comorbidity, and other potential causes of diarrhea for 68 test positive patients (cases) and 265 randomly selected test negative patients (controls) within the study cohort. Results The overall prevalence of positive cytotoxin assays was 14%. Prior antibiotic therapy (OR = 9.0, 95% CI 2.1-38.4), significant diarrhea (OR = 2.2, 95% CI 1.1-4.7), and abdominal pain (OR = 1.9, 95% CI 0.96-3.7) were independent predictors of cytotoxin assay results. The model discriminated patients with positive and negative assays with a receiver operating characteristic (ROC) area of 0.68; observed and predicted probabilities of a positive cytotoxin assay were well correlated over the entire range of observed probabilities (r 2 = 0.86). A decision rule (defined as positive if prior antibiotic use and either significant diarrhea or abdominal pain are present) demonstrated sensitivity and specificity of 86 and 45%. When applied to the entire dataset (N = 480), a simplified a priori rule, defined as positive if both prior antibiotic use and history of significant diarrhea are present, demonstrated sensitivity, specificity, positive and negative predictive value of 80, 45, 18 and 94%, respectively (6% of those predicted to be cytotoxin-negative actually tested positive). Use of this rule would have averted 39% of cytotoxin assays in our study population. Conclusions Patients without prior antibiotic use and either significant diarrhea or abdominal pain are unlikely to have positive C difficile cytotoxin assay results, and may not routinely require cytotoxin testing.
Piezoelectric vibration energy harvesting system with an adaptive frequency tuning mechanism for intelligent tires

Abstract The high vibration levels inside a tire have the potential to generate electrical power using vibration based energy harvesting techniques. In this paper, the feasibility of using an inertial vibrating energy harvester unit to power a sensor module inside the tire is assessed. The harvester unit is adapted to the tire vibration spectra and the superimposed acceleration signal. First prototypes demonstrate power generation capabilities sufficient enough to transmit tire sensor data multiple times per minute. To optimize the harvester performance with changing dominant tire vibration frequencies, a novel artificial neural network (ANN) based closed loop system capable of ensuring broad band operations has been proposed. By presenting a batteryless power supply unit, the proposed system addresses one of the key challenges in the realization of the intelligent tire concept.
Antibiotic resistance of Pseudomonas species

Pseudomonas species are highly versatile organisms with genetic and physiologic capabilities that allow them to flourish in environments hostile to most pathogenic bacteria. Within the lung of the patient with cystic fibrosis, exposed to a number of antimicrobial agents, highly resistant clones of Pseudomonas are selected. These may have acquired plasmid-mediated genes encoding a variety of β -lactamases or aminoglycoside modifying enzymes. Frequently these resistance determinants are on transposable elements, facilitating their dissemination among the population of bacteria. Mutations in chromosomal genes can also occur, resulting in constitutive expression of normally repressed enzymes, such as the chromosomal cephalosporinase of Pseudomonas aeruginosa or Pseudomonas cepacia . These enzymes may confer resistance to the expanded-spectrum β -lactam drugs. Decreased cellular permeability to the β -lactams and the aminoglycosides also results in clinically significant antibiotic resistance. The development of new drugs with anti- Pseudomonas activity, β -lactam agents and the quinolones, has improved the potential for effective chemotherapy but has not surpassed the potential of the organisms to develop resistance.