cssi/SciSciGPT-SciSciNet huggingface dataset:
The Human Cervical Spine in Tension: Effects of Frame and Fixation Compliance on Structural Responses

There is little data available on the responses of the human cervical spine to tensile loading. Such tests are mechanistically and technically challenging due to the variety of end conditions that need to be imposed and the difficulty of strong specimen fixation. As a result, spine specimens need to be tested using fairly complex, and potentially compliant, apparati in order to fully characterize the mechanical responses of each specimen. This, combined with the relatively high stiffness of human spine specimens, can result in errors in stiffness calculations. In this study, 18 specimen preparations were tested in tension. Tests were performed on whole cervical spines and on spine segments. On average, the linear stiffness of the segment preparations was 257 N/mm, and the stiffness of the whole cervical spine was 48 N/mm. The test frame was found to have a stiffness of 933 N/mm. Assembling a whole spine from a series combination of eight segments with a stiffness of 257 N/mm results in an estimated whole spine stiffness of 32.1 N/mm (32% error). The segment stiffnesses were corrected by assuming that the segment preparation stiffness is a series combination of the stiffnesses of the segment and the frame. This resulted in an average corrected segment stiffness of 356 N/mm. Taking the frame compliance into account, the whole spine stiffness is 51 N/mm. A series combination of eight segments using the corrected stiffnesses results in an estimated whole spine stiffness of 45.0 N/mm (12% error). We report both linear and nonlinear stiffness models for male spines and conclude that the compliance of the frame and the fixation must be quantified in all tension studies of spinal segments. Further, reported stiffness should be adjusted to account for frame and fixation compliance.
Poor survival after liver retransplantation: Is hepatitis C to blame?

Data from 1990 to 1996 suggest that the prevalence of hepatitis C virus (HCV) infection in repeated orthotopic liver transplantation (re-OLT) is increasing, and patient survival may be worse. Aims of the study are to: (1) assess the prevalence of HCV in re-OLT, (2) compare survival between primary OLT and re-OLT for HCV versus non-HCV diseases, and (3) evaluate Model for End-Stage Liver Disease (MELD) scores in re-OLT. The United Network for Organ Sharing database for adult patients undergoing primary OLT or re-OLT from January 1996 to June 2002 was analyzed. Patients with malignancy or those who underwent re-OLT within 30 days of primary OLT were excluded. A total of 22,120 primary OLTs and 2,129 re-OLTs were performed. HCV was noted in 9,564 primary OLTs (43.2%) and 899 re-OLTs (42.2%). Overall 1, 3, and 5-year patient survival rates were 86%, 79%, and 73% for primary OLT, but 67%, 56%, and 52% for re-OLT (P <.001). Survival rates of patients with HCV at 1, 3, and 5 years were 86%, 76%, and 68% for primary OLT and 61%, 50%, and 45% for re-OLT (P <.001). Survival was less for patients with HCV compared with those with autoimmune hepatitis (AIH) and hepatitis B for re-OLT (P <.01). However, survival after re-OLT was no different for those with HCV than for those with all other causes. MELD scores between 11 and 20 were the most common for re-OLT. A marked decreased in survival was noted in all patients who underwent re-OLT with MELD scores greater than 25. HCV prevalence in OLT has reached a plateau in recent years. Survival after re-OLT is inferior to that for primary OLT, but re-OLT survival appears to have improved. Survival after re-OLT is lower in patients with HCV compared with those with AIH and hepatitis B, but no different than for those with most other liver diseases. Survival appeared worse in patients who underwent re-OLT with a MELD score greater than 25.
An electron microscopic study of the epidermal infiltrate in recurrent herpes simplex.

Summary Host immunity has been suspected of playing a role in recurrent herpes simplex. In this preliminary ultrastructural study of two patients with acute herpetic eruption, it was noted that the keratinocytes exhibiting the most severe damage are those adjacent to large granular lymphocytes. In contrast, many keratinocytes filled with viral particles of herpes simplex show little or no signs of keratinocyte damage. These observations suggest that in recurrent herpes simplex the epidermal damage may be due, at least in part, to cell-mediated host immunity as well as to the viral infection.
Opportunistic scheduling with limited channel state information: A rate distortion approach

We consider an opportunistic communication system in which a transmitter selects one of multiple channels over which to schedule a transmission, based on partial knowledge of the network state. We characterize a fundamental limit on the rate that channel state information must be conveyed to the transmitter in order to meet a constraint on expected throughput. This problem is modeled as a causal rate distortion optimization of a Markov source. We introduce a novel distortion metric capturing the impact of imperfect channel state information on throughput. We compute a closed-form expression for the causal information rate distortion function for the case of two channels, as well as an algorithmic upper bound on the causal rate distortion function. Finally, we characterize the gap between the causal information rate distortion and the causal entropic ratedistortion functions.
Graph-based detection of shilling attacks in recommender systems

Collaborative filtering has been widely used in recommender systems as a method to recommend items to users. However, by using knowledge of the recommendation algorithm, shilling attackers can generate fake profiles to increase or decrease the popularity of a targeted set of items. In this paper, we present a method to make recommender systems resistant to these attacks in the case that the attack profiles are highly correlated with each other. We formulate the problem as finding a maximum submatrix in the similarity matrix. We search for the maximum submatrix by transforming the problem into a graph and merging nodes by heuristic functions or finding the largest component. Experimental results show that the proposed approach can improve detection precision compared to state of art methods.
The vectorcardiographic QRSsÊ-loop findings in inferoposterior myocardial infarction

Abstract 1.1. The QRSsE-loop findings have been described in vectorcardiograms recorded with the Frank lead system from 100 subjects without clinically detectable heart disease and from 153 patients with inferoposterior myocardial infarction. 2.2. In the vectorcardiograms of cases of diaphragmatic (inferior), posterolateral, and diaphragmatic-posterolateral infarction, the abnormality most consistently observed was deviation of the mean 0.02-second instantaneous vector, and, to a lesser extent, the maximal or mean 0.04-second instantaneous vector, of the planar QRS loops away from the effective electrical site of the infarction. 3.3. In cases of strictly posterior infarction the QRSsE loop displayed an anterior deviation of the maximal or mean 0.04-second and subsequent instantaneous QRS vectors.
Drosophila Sld5 is essential for normal cell cycle progression and maintenance of genomic integrity.

Research highlights: {yields} Drosophila Sld5 interacts with Psf1, PPsf2, and Mcm10. {yields} Haploinsufficiency of Sld5 leads to M-phase delay and genomic instability. {yields} Sld5 is also required for normal S phase progression. -- Abstract: Essential for the normal functioning of a cell is the maintenance of genomic integrity. Failure in this process is often catastrophic for the organism, leading to cell death or mis-proliferation. Central to genomic integrity is the faithful replication of DNA during S phase. The GINS complex has recently come to light as a critical player in DNA replication through stabilization of MCM2-7 and Cdc45 as a member of the CMG complex which is likely responsible for the processivity of helicase activity during S phase. The GINS complex is made up of 4 members in a 1:1:1:1 ratio: Psf1, Psf2, Psf3, And Sld5. Here we present the first analysis of the function of the Sld5 subunit in a multicellular organism. We show that Drosophila Sld5 interacts with Psf1, Psf2, and Mcm10 and that mutations in Sld5 lead to M and S phase delays with chromosomes exhibiting hallmarks of genomic instability.
Java programming and Internet technologies for undergraduate education

Although it is somewhat of a cliche that computers are revolutionizing education, it is still not common to find computer-based interactive curricular material. Internet technologies are likely to change this situation by providing standards based on virtual machines and meta-languages. Adopting these technologies may improve the teaching of the underlying physics. This paper describes a set of Java applets, known as Physlets, that make use of these technologies. Physlets are designed to communicate with browsers by employing a scripting language such as JavaScript, thereby allowing one applet to be used in many different contexts.
When a single custodial father receives child support

Abstract A recent survey of single fathers with custody provides one of the first explorations of the characteristics of those situations wherein the father receives child support. Fathers are more apt to be recipients if the noncustodial mother's income is known, if all the children are living with the father, if the mother earns more than the father, if the father was involved in childcare during the marriage, and if the children are younger. The amount of the support is discussed, as are implications for family therapists.
Inheritance of Premeal Stomach Content Influences on Food Intake in Free Living Humans

The heritability of the before-meal stomach content effects on food intake was investigated with 110 identical and 102 fraternal same-sex and 53 fraternal mixed-gender adult twin pairs who were paid to maintain 7-day food intake diaries. From the diary reports, the total and meal intakes of food energy and the amounts of the macronutrients ingested were estimated. A simple computer model of stomach emptying was used to estimate the contents of the stomach at the beginning and end of the meals. Linear structural modeling was applied to investigate the nature and degree of genetic and environmental influences and revealed significant genetic influences on the amount of food energy and macronutrients estimated to be present in the stomach at the beginning and end of meals. However, these influences were found to be secondary to genetic influences on overall intake and meal size such that when these were considered in the model the heritabilities for stomach contents vanished. The genes were also found to affect the magnitude of the negative correlations between the before meal stomach contents and the amounts of nutrients ingested, and the magnitude of the negative slope of the best-fitting regression line between before meal stomach contents and meal size. These results suggest that although the amount in the stomach found at meal time is only affected indirectly by the genes, the impact of the content of the stomach on the amount ingested is to some extent inherited. This suggests that responses to internal stimuli are influenced by the genes and become part of the total package of genetically determined physiological and psychological processes that regulate energy balance.
Toward systematic design of fault-tolerant systems

After 30 years of study and practice in fault tolerance, high-confidence computing remains a costly privilege of several critical applications. It is time to explore ways to deliver high-confidence computing to all users. The speed of computing will ultimately be limited by the laws of physics, but the demand for affordable high-confidence computing will continue as long as people use computers to enhance the quality of their lives. Eventually, one enterprising chip builder will deliver the first fault-tolerant microprocessor at a competitive price, and soon thereafter fault tolerance will be considered as indispensable to computers as immunity is to humans. The remaining manufacturers will follow suit or go the way of the dinosaurs. Once again, Darwin will be proven right.
Numerical modeling of three-dimensional two-phase gas–liquid flow in the flow field plate of a PEM electrolysis cell

Numerical simulations were performed for three-dimensional two-phase water/oxygen flow in the flow field plate at the anode side of a PEM electrolysis cell. The mixture model was used to simulate two phases for the purpose of examining flow features in the flow field plate in order to effectively guide the design of electrolysis cells. The water flow rate was maintained as a constant of 260 mL/min, while the flow rate of oxygen generation was assumed to change from 0 to 14 mg/s. The obtained results including the velocity, pressure, and volume fraction distributions are presented and discussed. It is found that the obtained results for single-phase flow cases cannot be linearly extrapolated into the two-phase flow cases. The irregular velocity profile (locally low velocity magnitude near the exit port section) is not observed when the flow rate of oxygen generation is relatively low. As the mass flow rate of oxygen generation increases, reverse flow develops inside the flow channels.
Recent advances in capillary electrophoretic analysis of individual cells

Because variability exists within populations of cells, single-cell analysis has become increasingly important for probing complex cellular environments. Capillary electrophoresis (CE) is an excellent technique for identifying and quantifying the contents of single cells owing to its small volume requirements and fast, efficient separations with highly sensitive detection. Recent progress in both whole-cell and subcellular sampling has allowed researchers to study cellular function in the areas of neuroscience, oncology, enzymology, immunology, and gene expression.
Chemotherapeutic Agents Increase the Risk for Pulmonary Function Test Abnormalities in Patients With Multiple Myeloma

Abstract Background Multiple myeloma is a common malignancy accounting for approximately 1% of all malignancies worldwide. Bortezomib, lenalidomide, and thalidomide are immunomodulatory derivatives that are used in the treatment of multiple myeloma (MM). There have been case reports of pulmonary disease associated with these agents, but the effect of these agents on pulmonary function test (PFT) results is unknown. Patients and Methods We reviewed the records of 343 patients with MM who underwent PFTs before autologous stem cell transplantation. One hundred nine patients had not received any of the 3 medications, whereas 234 had received 1 or more of these agents. Results Patients exposed to bortezomib were more likely to have obstructive PFT results ( P = .015) when compared with patients not exposed to this medication. Restrictive PFT results were more likely after exposure to thalidomide ( P = .017). A logistic regression model was performed and when adjusted for age, sex, Durie-Salmon (DS) stage, body mass index (BMI), time from diagnosis to transplantation in days, and smoking history, the odds of obstruction were 1.96 times higher for patients who received bortezomib. The odds of restriction were 1.97 times higher after exposure to thalidomide. Conclusion There appears to be a risk of PFT abnormalities developing in patients treated with bortezomib and thalidomide.
Functional map of human cytomegalovirus AD169 defined by global mutational analysis.

Human cytomegalovirus has a complex double-stranded DNA genome of ≈240,000 bp that contains ≈150 ORFs likely to encode proteins, most of whose functions are not well understood. We have used an infectious bacterial artificial chromosome to introduce 413 defined insertion and substitution mutations into the human cytomegalovirus AD169 genome by random and site-directed transposon mutagenesis. Mutations were produced in all unique ORFs with a high probability of encoding proteins for which mutants have not been previously documented and in many previously characterized ORFs. The growth of selected mutants was assayed in cultured human fibroblasts, and we now recognize 41 essential, 88 nonessential, and 27 augmenting ORFs. Most essential and augmenting genes are located in the central region, and nonessential genes generally cluster near the ends of the viral genome.
Influence of dibutyl phthalate on the mechanical, thermal, and relaxation behaviour of poly (methyl methacrylate) for denture-base soft liners

Methyl methacrylate and six solutions of methyl methacrylate/dibutyl phthalate (nominally 5 to 30% v/v) were polymerized into thin sheets using gamma radiation. Dynamic mechanical spectra of the storage modulus, loss modulus and loss tangent, as well as changes in length, were investigated as a function of temperature. From these measurements, the depression of the storage modulus and glass-transition temperature were obtained. Subsequently, differential scanning calorimetry (DSC) and cross-polarization-magic-angle-spinning NMR were used to obtain additional glass-transition and relaxation-time measurements. Based upon these experiments, a specific form of the rule of mixtures described the depression of the glass-transition temperature. From storage-modulus measurements, antiplasticization was evidenced at very low temperatures and at compositions greater than 25% v/v. Solid-state NMR confirmed that plasticization causes an increase in polymer main-chain motion via the physical loosening of secondary bonds between polymer chains.
In-situ observations of ion implanted surfaces

Abstract A scanning electron microscope facility is described which enables direct observations of sample surfaces during implantation. This technique enables measurements of the growth rates of surface features caused by He implantation of metals. Results from 300 keV He + implantation of Ti samples indicate that exfoliation or flaking of the sample surface is a distinctly different process from blistering, and proceeds at radically different rates. In addition, it was observed that exfoliation could be significantly reduced by cold-working.
Prochondrogenic signals induce a competence for Runx2 to activate hypertrophic chondrocyte gene expression

Whereas Runx2 is necessary for bone formation and cartilage hypertrophy, it is unclear why Runx2 induces markers of chondrocyte hypertrophy only in chondrocytes. We document that chondrocytes either contain a cofactor, which can be induced in somitic cells by prochondrogenic signals, that is necessary for Runx2 to induce chondrocyte hypertrophy or, alternatively, lack a repressor of this maturation program. Sequential Shh and bone morphogenetic protein (BMP) signals or forced expression of either Nkx3.2 or Sox9 (plus BMP signals) induces chondrogenesis in presomitic mesoderm and simultaneously induces a competence for Runx2 to activate the chondrocyte maturation program. The ability of either sequential Shh and BMP signals or retrovirus-encoded Nkx3.2 or Sox9 to induce this competence correlates with their ability to activate chondrogenesis in various embryonic tissues. Consistent with these findings in embryonic tissues, we have found that cotransfected Runx2 and Smad1 are able to induce the expression of a reporter construct driven by the collagen X regulatory sequences in chondrocytes but not in fibroblasts. In contrast, both Runx2 and Smad1 are competent to activate reporters driven by either reiterated Runx or Smad binding sites, respectively, in both cell types. As Sox9 and Nkx3.2 have previously been shown to block chondrocyte maturation in vivo, our findings suggest that these transcription factors can, in addition, either induce the expression or activity of a factor in chondrocytes that is required for Runx2 to activate the chondrocyte maturation program, or alternatively that these transcription factors block the expression or activity of a repressor of this maturation program.
A Truncated Maximum Likelihood Estimator of a Constrained Bivariate Linear Regression Coefficient

Abstract In a bivariate linear regression model, the constrained maximum likelihood estimator (MLE) of a regression coefficient usually has smaller variance than the unconstrained MLE. This situation can be reversed if both the sample size n and the correlation coefficient ρ of disturbances between two regression equations are small. That is, when both n and ρ are small, the variance of the unconstrained MLE is smaller than the constrained MLE. In this article, a truncated MLE is considered for the justification of using either the constrained or the unconstrained MLE as an appropriate estimator for the regression coefficient.
An interpretation of galactic observations of CNO isotopes

Nuclear network calculations are used to interpret observations of N-15/N-14 and O-17/O-18 abundance ratios in interstellar clouds. Recent observations of the N-15/N-14 abundance ratio in the galactic disk and the galactic center are consistent with the idea that N-15 is produced in intermediate-mass stars by means of the hot CNO tri-cycle. It is suggested that low-mass stars in the glactic center could be responsible for producing the local enhancement of O-17 by low-temperature (below 100 million K) CNO burning.
Kinetics of Hydrogen Desorption in NaAlH4 and Ti-Containing NaAlH4

Understanding the fundamental reaction path and identifying the rate-limiting steps in the decomposition of materials evolving hydrogen are two challenging tasks when studying complex metal hydrides as viable onboard hydrogen storage materials. In this work, we use computational techniques to study the free-energy barriers associated with the reactions involved in the evolution of hydrogen via the first step of sodium alanate decomposition (NaAlH4 → 1/3Na3AlH6 + 2/3Al + H2). Results from our calculations suggest a four-step reaction that includes the transition from AlH4− to AlH63− anions, Al clustering, and H2 evolution. The calculated free-energy barrier and enthalpy of activation associated with one molecule of H2 release are on the order of 80 and 82 kJ/mol H2, respectively. The rate-determining step for this mechanism is found to be the hydrogen evolution from associated AlH3 species. The role of titanium in the improved kinetics of Ti-containing sodium alanates is elucidated from our coupled density...
Supplementary report: Transfer as a function of the similarity between first-list stimuli and second-list responses

According to a transfer surface previously described, transfer should shift from positive to negative as the similarity between first-list stimuli and second-list responses (S1-R2) decreases. This study attempted to substantiate this prediction by measuring transfer effects for six degrees of S1-R2 similarity. The results supported the hypothesis; second-list performance decreased as S1-R2 similarity decreased.
PreproThyrotropin-releasing hormone 178-199 affects tyrosine hydroxylase biosynthesis in hypothalamic neurons: a possible role for pituitary prolactin regulation.

ProThyrotropin-releasing hormone (proTRH) is a prohormone widely distributed in many areas of the brain. After biosynthesis, proTRH is subjected to post-translational processing to generate TRH and seven non-TRH peptides. Among these non-TRH sequences, we found previously that preproTRH178–199 could regulate the secretion of prolactin in suckled rats by their pups. Dopamine (DA), the main regulator of prolactin secretion, is produced in dopaminergic tyrosine hydroxylase (TH)-positive neurons in the hypothalamic arcuate nucleus (ARC). In this study we investigated whether prolactin release during the estrous sexual cycle is regulated by prepro TRH178–199 through its effecton DA neurons of the ARC. We observed that biotinylated prepro TRH178–199 bound to neurons in the ARC; this was higher during proestrus than during diestrus. Binding of preproTRH178–199 to DA neurons was seen only during proestrus in the ARC. Using primary neuronal hypothalamic cultures we found that preproTRH178–199peptide decreased TH levels in a dose-responsive manner, whereas intra-ARC administration of preproTRH178–199 induced a 20-fold increase in plasma prolactin levels. Together, these results suggest a potential role for preproTRH178–199 in regulating dopaminergic neurons involved in the inhibition of pituitary prolactin release.
Evaluation by thoracic impedance cardiography of diazepam, placebo, and two drug combinations for intravenous sedation of dental outpatients

The cardiovascular and respiratory effects of three common intravenous premedicants were examined noninvasively in a population of 20 dental outpatients scheduled for surgical removal of third-molars. Two third molars from one side of the mouth were removed at each appointment. Group 1 received a diazepam titration (mean dose = 25.6 mgs) at one appointment and placebo at the other appointment. Group 2 received a combination of diazepam (12.5 mg), fentanyl (0.1 mg), and methohexital (mean dose = 18.0 mg) at one appointment and the combination of diazepam (15.0 mg) and methohexital (mean dose = 27.0 mg) at the other appointment. Noninvasive measurement of cardiac output revealed little change during intravenous drug administration, but a significant increase was seen in all groups following local anesthesia and during surgery. Heart rate was elevated and stroke volume decreased during administration of the two-drug combinations. Oxygen saturation was greatly decreased following the combination of diazepam, fentanyl, and methohexital. These findings indicate that the combination of diazepam, fentanyl, and methohexital results in decreased oxygen saturation, a transient decrease in stroke volume, and an elevated heart rate when used as an intravenous premedicant for dental outpatients.
Esthetic placement of bar-clasp direct retainers.

Abstract A technique has been described that will allow for the esthetic placement of artificial teeth by precisely controlling the location of the approach arm of the I-bar clasp.
Hybrid Rank and Variance of Corn at Sites with Contrasting Humic Matter Content

Widely adapted, high-yielding genotypes are most easily detected at sites in which differences among hybrids are large and where rankings are similar to the target environment. The objectives of this study were to determine if the relative yields, hybrid variances, and correlations with state-wide means for corn (Zea mays L.) hybrids differed among sites with low and high humic matter (HM) content. Five years of corn yield data from sites with contrasting HM content (0.032 vs. 0.059 g cm -3 ) located near Plymouth, NC, were collected. An analysis was performed for each year and maturity group which contained 12 to 48 hybrids. Mean yields averaged 12% (0.91 Mg ha -1 ) less at the high than low HM sites. Hybrid x HM interactions were significant (P < 0.05) in about half of all trials but rarely involved changes in the rank order among hybrids, indicating that duplicating trials on the two soil types was not warranted. Despite lower yields at the high HM sites, ranges and hybrid variances were larger in these sites. Maximum yields were less affected by soil type than minimum yields, indicating greater stress tolerance in high-yielding hybrids. A differential response among hybrids to some additional stress appeared to account for greater hybrid variances observed at the high HM sites. Correlations with state-wide mean performance were greater for high than low HM sites. Locating test sites on soils with high HM content may be an efficient way to detect hybrids capable of producing high yields under a range of soil and climatic conditions.
Hook immanants and symmetry-antisymmetry modules

We generalize the inequalities for the normalized hook immanants outside the set of class functions. To obtain our inequalities we analyse the restriction of the quadratic forms associated with the Schur power matrices to certain left ideals in the group algebra . We call these ideals symmetry-antisymmetry modules.
Model for a two‐cavity coating die with pressure and temperature deformation

Coating dies uniformly distribute liquid for application as a film to moving substrates using one or two cavities spanning the coating width and adjoining precision narrow slots of much higher resistance to flow. If the slots are deformed by the pressure of the liquid or by temperature gradients in the die bars, degradation in flow distribution can result. Consequently, dies are designed to be sufficiently stiff and are thermally jacketed to keep slot deformations within fabrication tolerances. To aid in design and operation, a model of low computational load is developed in which the flow and deformation analyses are directly coupled. Die deformation is modeled using classical beam theory taking account of the varying thickness of the bars due to cavity geometry. Two-dimensional finite element analysis of die deformation gives marginally higher slot deformation. Three-dimensional finite element analysis agrees with the two-dimensional analysis except near the center of the die where the symmetry boundary condition reduces deformation. The effects of die geometry on deformation and flow distribution are illustrated. POLYM. ENG. SCI., 2012. © 2011 Society of Plastics Engineers
Calculating the Phonon Modes of Graphene Using the 4th Nearest Neighbor Force Constant Method

Graphite has always been a very important material both industrially and academically due to its physical structure. But ever since the isolation of Graphene (a single sheet of Graphite) a few years ago, it’s been one of the most widely studied molecular systems for its potential applications in nano-electronics and other break-through areas. Some of the desirable traits of Graphene are its high thermal and electronic mobility, and its low noise properties. This paper outlines a standard method for calculating phonon dispersion curves in Graphene by making use of force constant measurements. This information is usually obtained from approximations of inter-atomic potentials, which involve derivatives of simplified potential approximations between every atom in Graphene to get the force constant tensors. In this paper, the measured values for the force constants are used in a mathematically rigorous way to calculate the Graphene phonon dispersion curves.Copyright © 2008 by ASME
Intersection problems and integral equivalence

Abstract Let A and B be matrices over a principal ideal domain, Π. Necessary conditions, involving the invariant factors of A and B , are given for B to be a submatrix of A or a principal submatrix of A . If a given nonnegative integral matrix, B , is the intersection matrix of a pair of families of subsets of an n -set, and n is the smallest integer for which this is true, we say that the content of B is n . In that event, B is a submatrix of K ( n ), the intersection matrix of all subsets of an n -set. More refined results are obtained in certain cases by considering S ( n , k , l ), the intersection matrix of the k -subsets of an n -set versus its l -subsets. The invariant factors of K ( n ) and S ( n , k , l ) are calculated and it is shown how this information may be used to get lower bounds for the content of B . In the more widely studied symmetric version of the content problem, B must be a principal submatrix of K ( n ) or, possibly, S ( n , k ) = S ( n , k , k ). In this case, the invariant factors of K ( n ) − xI or S ( n , k ) − xI also provide relevant information.
The role of pain behaviors in the modulation of marital conflict in chronic pain couples.

Sixty-one married male chronic benign back pain patients and their spouses were recruited in order to examine the relationship between marital conflict/stress and patient pain behaviors. The results suggest that marital conflict in pain couples is associated with increases in subsequent display of pain behaviors which, in turn, are associated with greater negative affective responses and more punitive behaviors by the spouse. A positive association was found between punitive spouse behaviors and patient physical and psychosocial impairment. The findings are discussed in terms of their clinical implications and the need for further experimental study of these relationships.
Tearing at the dayside magnetopause

Initial observations of the dayside magnetopause thickness using magnetometers on board ISEE 1 (International Sun-Earth Explorer) and ISEE 2 indicate that this boundary may only be a few ion gyro-radii thick during periods of observed southward interplanetary magnetic field (IMF). Such a thin current layer can destabilize the collisionless tearing mode, a probable first step in the reconnection sequence. The linear growth rate is calculated assuming typical magnetopause parameters and it is found that it is a sensitive function of IMF orientation, magnetopause thickness, and electron number density. It is also shown that the finite size of the dayside magnetopause necessitates the existence of a two-dimensional tearing mode wave vector spectrum, a consequence of the inability of a thermal electron to maintain Landau resonance with the wave for a growth period. Implications regarding reconnection are discussed.
Exploring subcultural differences in hofstede's value survey: The case of the Chinese

Hofstede's Value Survey Module (VSM) identifies fundamental differences in the way people in various countries perceive and interpret their worlds. After adjusting value scores on the basis of demographic features of samples in the present study, values between subcultural groupings in four Chinese-populated regions (Taiwan, Beijing, Hong Kong, and Wuhan) were compared, and strong subcultural differences revealed. A methodology is proposed to facilitate VSM comparisons using limited, secondary data sources. Propositions concerning subcultural differences are suggested on the basis of the findings.
Pharmacology Review: Drug Therapy and Breastfeeding: Pharmacokinetics, Risk Factors, and Effects on Milk Production

After completing this article, readers should be able to: 1. Describe the pharmacology of drug transfer into human milk. 2. Delineate the tools that the neonatologist can use to evaluate the relative risk for a breastfeeding infant if certain medications are used by his or her mother. 3. Describe the effects of various medications on the production of milk. 4. Characterize drug pharmacokinetics that can be used to reduce transfer of medications to milk and reduce the infant’s exposure. 5. Provide a method for evaluating the relative risk to an infant and those at low and high risk following exposure to various medications. New data continue to be published almost monthly that support human milk as the finest source of nutrition and the only source of exogenous immunoglobulins and protection against infections available to the newborn. During the first postnatal week, human milk is filled with immunoglobulins (IgG, IgA, and IgM), interferons, and other antibacterial substances, which results in colonization of the gastrointestinal (GI) tract of the newborn with benign bacterial flora. The presence of numerous growth factors (IgF-1), cytokines, and gastric hormones enhance development of protective barriers in the GI tract and stimulate elimination of the meconium that is present during gestation. Other key benefits to the infant include perfect nutrition, enhanced neurocognitive development, stronger immune function, and at least a threefold reduction in the incidence of infectious diseases such as upper respiratory tract infections, otitis media, and necrotizing enterocolitis. Although recent studies have suggested that the number of women who choose to breastfeed their infants is 72% and rising in the United States, the number of women who discontinue breastfeeding to take a medication is very high. Surveys in many countries indicate that 90% to 99% of women who breastfeed receive a medication during the first week postpartum. Another study of Scandinavian women …
Prevention of cardiomyopathy in mouse models lacking the smooth muscle sarcoglycan-sarcospan complex

Cardiomyopathy is a multifactorial disease, and the dystrophin-glycoprotein complex has been implicated in the pathogenesis of both hereditary and acquired forms of the disease. Using mouse models of cardiomyopathy made by ablating genes for components of the sarcoglycan complex, we show that long-term treatment with verapamil, a calcium channel blocker with vasodilator properties, can alleviate the severe cardiomyopathic phenotype, restoring normal serum levels for cardiac troponin I and normal cardiac muscle morphology. Interruption of verapamil treatment leads again to vascular dysfunction and acute myocardial necrosis, indicating that predilection for cardiomyopathy is a continuing process. In contrast, verapamil did not prevent cardiac muscle pathology in dystrophin-deficient mdx mice, which neither show a disruption of the sarcoglycan complex in vascular smooth muscle nor vascular dysfunction. Hence, our data strongly suggest that pharmacological intervention with verapamil merits investigation as a potential therapeutic option not only for patients with sarcoglycan mutations, but also for patients with idiopathic cardiomyopathy associated with myocardial ischemia not related to atherosclerotic coronary artery disease.
Abortion Politics, Mass Media, and Social Movements in America

Introduction: dilemmas, choices, and consequences 1. Constraints of strategic choice 2. The mass media field 3. Abortion, social movements, and mass media 4. Media, politics, and the National Right to Life Committee 5. Reputation, political change, and the National Organization for Women 6. Branding and the success of Planned Parenthood 7. Concerned Women for America and sympathetic media 8. Conclusion Afterword: abortion politics in the twenty-first century.
Hydrogen-acceptor pairs in silicon: Pairing effect on the hydrogen vibrational frequency.

We calculate the electronic structures of the hydrogen-boron and hydrogen-aluminum pairs in silicon which are believed to form when the corresponding shallow acceptor activity is neutralized by hydrogen. In particular, computed infrared vibrational frequencies are reported for the first time and compared with recent experimental measurements. Both theory and experiment reveal an interesting reduction in the vibrational frequency for hydrogen in the H-B pair with respect to the isolated monohydride. This we analyze in terms of two- and three-body interactions involving the hydrogen, the acceptor impurity, and the nearby silicon atoms.
Insight into the Mechanism of the Influenza A Proton Channel from a Structure in a Lipid Bilayer

The M2 protein from the influenza A virus, an acid-activated proton-selective channel, has been the subject of numerous conductance, structural, and computational studies. However, little is known at the atomic level about the heart of the functional mechanism for this tetrameric protein, a His37-Trp41 cluster. We report the structure of the M2 conductance domain (residues 22 to 62) in a lipid bilayer, which displays the defining features of the native protein that have not been attainable from structures solubilized by detergents. We propose that the tetrameric His37-Trp41 cluster guides protons through the channel by forming and breaking hydrogen bonds between adjacent pairs of histidines and through specific interactions of the histidines with the tryptophan gate. This mechanism explains the main observations on M2 proton conductance.
A quality based routing protocol for wireless mesh networks

Abstract Wireless mesh networks can provide low-cost solutions for extending the reach of wireless access points by using multi-hop routing over a set of stationary wireless routers. The routing protocol for these networks may need to address quality considerations to meet the requirements of the user. In this paper, we present a quality based routing protocol for wireless mesh networks that tries to maximize the probability of successful transmissions while minimizing the end-to-end delay. The proposed routing protocol uses reactive route discoveries to collect key parameters from candidate routes to estimate the probability of success and delay of data packets transmitted over them. To achieve accurate route quality assessments, a new route quality metric is proposed that uses performance models of data packet transmissions as opposed to estimating route quality from the transmission of control packets, which have different transmission characteristics. These models are developed after careful evaluations of multi-hop wireless transmissions and validated by computer simulations. Relevant parameters that can be used to assess the route quality metric using these models are explained. Extensive performance evaluations of the proposed quality based routing protocol are presented and its benefits in comparison to some other known routing protocols are discussed.
ESTIMATION IN LONG‐MEMORY TIME SERIES MODEL

This study deals with the parameter estimation in long-memory time series models. An unbiased and consistent estimator is proposed. The proposed estimator is based on a least-squares method in the frequency domain, and it is computationally simple. Also, the Cramer–Rao lower bound is derived. The mean-square error of the proposed estimator is order of O(1/N), where N is the number of samples. The accuracy of the estimates is verified using synthetic long-memory time series data.
Autonomous CaMKII Mediates Both LTP and LTD Using a Mechanism for Differential Substrate Site Selection

Traditionally, hippocampal long-term potentiation (LTP) of synaptic strength requires Ca(2+)/calmodulin (CaM)-dependent protein kinase II (CaMKII) and other kinases, whereas long-term depression (LTD) requires phosphatases. Here, we found that LTD also requires CaMKII and its phospho-T286-induced "autonomous" (Ca(2+)-independent) activity. However, whereas LTP is known to induce phosphorylation of the AMPA-type glutamate receptor (AMPAR) subunit GluA1 at S831, LTD instead induced CaMKII-mediated phosphorylation at S567, a site known to reduce synaptic GluA1 localization. GluA1 S831 phosphorylation by "autonomous" CaMKII was further stimulated by Ca(2+)/CaM, as expected for traditional substrates. By contrast, GluA1 S567 represents a distinct substrate class that is unaffected by such stimulation. This differential regulation caused GluA1 S831 to be favored by LTP-type stimuli (strong but brief), whereas GluA1 S567 was favored by LTD-type stimuli (weak but prolonged). Thus, requirement of autonomous CaMKII in opposing forms of plasticity involves distinct substrate classes that are differentially regulated to enable stimulus-dependent substrate-site preference.
You got a problem with that? Exploring evaluators' disagreements about ethics.

A random sample of American Evaluation Association (AEA) members were surveyed for their reactions to three case scenarios—informed consent, impartial reporting, and stakeholder involvement—in which an evaluator acts in a way that could be deemed ethically problematic. Significant disagreement among respondents was found for each of the scenarios, in terms of respondents' views of whether the evaluator had behaved unethically. Respondents' explanations of their judgments support the notion that general guidelines for professional behavior (such as AEA's Guiding Principles for Evaluators) can encompass sharply conflicting interpretations of how evaluators should behave in specific situations. Respondents employed in private business/consulting were less likely than those in other settings to believe that the scenarios portrayed unethical behavior by the evaluator, a finding that underscores the importance of taking contextual variables into account when analyzing evaluators' ethical perceptions. The need f...
Meniscal flounce MR imaging.

PURPOSE: To determine the prevalence of a meniscal flounce, the magnetic resonance (MR) imaging characteristics, and whether the flounce is associated with a meniscal tear. MATERIALS AND METHODS: Knee MR images obtained in 3,159 examinations over 2 years were prospectively evaluated. Ten adult patients (six with true flounces, four with flouncelike folds associated with meniscal tears) with an S-shaped fold in the free edge of a meniscus on sagittal images were included. Five underwent arthroscopic surgery. RESULTS: The prevalence of a flounce was 0.2% (six of 3,159 examinations). Five occurred in the medial meniscus (MM) and one occurred in the lateral meniscus (LM). All appeared truncated in the coronal plane. Four meniscal tears also demonstrated flouncelike folds. Three were confirmed with surgery and one was confirmed with clinical findings. Of the 3,159 MR examinations, 1,151 demonstrated an MM tear, 832 an LM tear, 542 MM degeneration, and 270 LM degeneration. CONCLUSION: A meniscal flounce is a fo...
Nest-site selection and nest depredation of semi-aquatic turtles on golf courses

Urban landscapes present various challenges to semi-aquatic turtle reproduction. In developed regions, golf courses may provide some of the best remaining habitat for turtle populations. We explored nest-site selection of eastern painted turtles (Chrysemys picta) at a golf course pond in Davidson, North Carolina, USA, and modeled nest-site preference using Akaike Information Criterion, with the best supported model favoring nests surrounded by mulch and mowed grass. Additionally, we evaluated nest depredation rates using simulated turtle nests and found that golf course ponds did not have significantly greater nest depredation compared to urban and rural ponds. Our results suggest that golf courses may offer suitable habitat for turtle reproduction in developed areas.
Use of Buccal Mucosa in Hypospadias Repair

Hypospadias is an embryological disorder that results in an abnormal ventral positioning of the urethral meatus. Among multiple surgical techniques described to correct this anomaly, the use of buccal mucosa grafts has gained popularity among pediatric urologists, pediatric surgeons and plastic surgeons. Buccal mucosa grafts have shown favorable histological changes that result in an excellent scaffold for urethral reconstructive surgery. This review describes the evolution of the use of buccal mucosa grafts in hypospadias repair.
Type III Secretion Is Essential for the Rapidly Fatal Diarrheal Disease Caused by Non-O1, Non-O139 Vibrio cholerae

Cholera is a severe diarrheal disease typically caused by O1 serogroup strains of Vibrio cholerae. The pathogenicity of all pandemic V. cholerae O1 strains relies on two critical virulence factors: cholera toxin, a potent enterotoxin, and toxin coregulated pilus (TCP), an intestinal colonization factor. However, certain non-O1, non-O139 V. cholerae strains, such as AM-19226, do not produce cholera toxin or TCP, yet they still cause severe diarrhea. The molecular basis for the pathogenicity of non-O1, non-O139 V. cholerae has not been extensively characterized, but many of these strains encode related type III secretion systems (TTSSs). Here, we used infant rabbits to assess the contribution of the TTSS to non-O1, non-O139 V. cholerae pathogenicity. We found that all animals infected with wild-type AM-19226 developed severe diarrhea even more rapidly than rabbits infected with V. cholerae O1. Unlike V. cholerae O1 strains, which do not damage the intestinal epithelium in rabbits or humans, AM-19226 caused marked disruptions of the epithelial surface in the rabbit small intestine. TTSS proved to be essential for AM-19226 virulence in infant rabbits; an AM-19226 derivative deficient for TTSS did not elicit diarrhea, colonize the intestine, or induce pathological changes in the intestine. Deletion of either one of the two previously identified or two newly identified AM-19226 TTSS effectors reduced but did not eliminate AM-19226 pathogenicity, suggesting that at least four effectors contribute to this strain's virulence. In aggregate, our results suggest that the TTSS-dependent virulence in non-O1, non-O139 V. cholerae represents a new type of diarrheagenic mechanism.