cssi/SciSciGPT-SciSciNet huggingface dataset:
Geometric mapping properties of semipositive matrices

Abstract Semipositive matrices map a positive vector to a positive vector and as such they are a very broad generalization of the irreducible nonnegative matrices. Nevertheless, the ensuing geometric mapping properties of semipositive matrices result in several parallels to the theory of cone preserving and cone mapping matrices. It is shown that for a semipositive matrix A , there exist a proper polyhedral cone K 1 of nonnegative vectors and a polyhedral cone K 2 of nonnegative vectors such that A K 1 = K 2 . The set of all nonnegative vectors mapped by A to the nonnegative orthant is a proper polyhedral cone; as a consequence, A belongs to a proper polyhedral cone comprising semipositive matrices. When the powers A k ( k = 0 , 1 , … ) have a common semipositivity vector, then A has a positive eigenvalue. If A has a sole peripheral eigenvalue λ and the powers of A have a common semipositivity vector with a non-vanishing term in the direction of the left eigenspace of λ , then A leaves a proper cone invariant.
Ultrasonic Welding of Bulk Carbon Nanotube Conductors

Incorporation of bulk carbon nanotube (CNT) conductors into energy and data systems can require new methods of making a functional interface with low electrical contact resistance and high mechanical strength. Ultrasonic welding has been shown as a viable technique for mechanically and electrically bonding commercial CNT materials (CVD) to copper foil. The mechanical strength across the ultrasonic welds was measured via dynamic mechanical analysis with single lap welds exceeding 350 kPa. The electrical properties of the ultrasonically welded bulk CNT conductors (chemically doped with KAuBr4) to Cu were measured via 4-point probe and show specific contact resistance between the CNTs and copper as low as 4.3 mΩ cm2. Thus, ultrasonic welding represents a mechanically robust method for making functional contacts between bulk CNTs and metallic interconnects with a low contact resistance. In addition, ultrasonic welding was successfully used to join two CNT ribbons end-to-end (breaking strength of single lap welds exceeding 200 kPa) demonstrating that it is also a viable technique for making larger dimension CNT materials from smaller components.
Reductions in Costly Healthcare Service Utilization: Findings from the Care Advocate Program

OBJECTIVES: To determine whether a telephone care-management intervention for high-risk Medicare health maintenance organization (HMO) health plan enrollees can reduce costly medical service utilization. DESIGN: Randomized, controlled trial measuring healthcare services utilization over three 12-month periods (pre-, during, and postintervention). SETTING: Two social service organizations partnered with a Medicare HMO and four contracted medical groups in southern California. PARTICIPANTS: Eight hundred twenty-three patients aged 65 and older; eligibility was determined using an algorithm to target older adults with high use of insured healthcare services. INTERVENTION: After assessment, members in the intervention group were offered mutually agreed upon referrals to home- and community-based services (HCBS), medical groups, or Medicare HMO health plan and followed monthly for 1 year. MEASUREMENTS: Insured medical service utilization was measured across three 12-month periods. Acceptance and utilization of Care Advocate (CA) referrals were measured during the 12-month intervention period. RESULTS: CA intervention members were significantly more likely than controls to use primary care physician services (odds ratio (OR)=2.05, P<.001), and number of hospital admissions (OR=0.43, P<.01) and hospital days (OR=0.39, P<.05) were significantly more stable for CA group members than for controls. CONCLUSION: Results suggest that a modest intervention linking older adults to HCBS may have important cost-saving implications for HMOs serving community-dwelling older adults with high healthcare service utilization. Future studies, using a national sample, should verify the role of telephone care management in reducing the use of costly medical services.
Substrate-induced conformational changes of liver fructose 1,6-diphosphatase studied with the hydrophobic probe, 1-anilinonaphthalene-8-sulfonate.

Abstract The fluorescence emission of the hydrophobic probe, 1-anilinonaphthalene-8-sulfonate, was markedly increased in the presence of rabbit liver fructose 1,6-diphosphatase. Substrate produced a specific and reversible decrease in the fluorescence yield, which was linearly related to the amount of bound fructose-1,6-di-P. The fluorophore was very weakly bound to the phosphatase (Kdiss = 1.5 x 10-4 m). Addition of substrate did not change this binding constant but lowered the maximum emission yield. A very close agreement was found among the following constants for enzyme-substrate interaction: Km, Kdiss, and the substrate concentrations needed for half-maximal binding of AMP and for half-maximal fluorescence quenching. The fluorescence quenching of the enzyme-dye complex is further evidence for a substrate-induced change in protein conformation.
Neoplastic transformation of porcine mammary epithelial cells in vitro and tumor formation in vivo

The mammary glands of pigs share many functional and morphological similarities with the breasts of humans, raising the potential of their utility for research into the mechanisms underlying normal mammary function and breast carcinogenesis. Here we sought to establish a model for the efficient manipulation and transformation of porcine mammary epithelial cells (pMEC) in vitro and tumor growth in vivo. We utilized a vector encoding the red florescent protein tdTomato to transduce populations of pMEC from Yorkshire –Hampshire crossbred female pigs in vitro and in vivo. Populations of primary pMEC were then separated by FACS using markers to distinguish epithelial cells (CD140a-) from stromal cells (CD140a+), with or without further enrichment for basal and luminal progenitor cells (CD49f+). These separated pMEC populations were transduced by lentivirus encoding murine polyomavirus T antigens (Tag) and tdTomato and engrafted to orthotopic or ectopic sites in immunodeficient NOD.Cg-Prkdc scid Il2rg tm1Wjl /SzJ (NSG) mice. We demonstrated that lentivirus effectively transduces pMEC in vitro and in vivo. We further established that lentivirus can be used for oncogenic-transformation of pMEC ex vivo for generating mammary tumors in vivo. Oncogenic transformation was confirmed in vitro by anchorage-independent growth, increased cell proliferation, and expression of CDKN2A, cyclin A2 and p53 alongside decreased phosphorylation of Rb. Moreover, Tag-transformed CD140a- and CD140a-CD49f + pMECs developed site-specific tumors of differing histopathologies in vivo. Herein we establish a model for the transduction and oncogenic transformation of pMEC. This is the first report describing a porcine model of mammary epithelial cell tumorigenesis that can be applied to the study of human breast cancers.
Development of the Polipo Pressure Sensing System for Dynamic Space-Suited Motion

Working inside the space suit causes injury and discomfort, but suit assessment techniques such as measuring joint torques and ranges of motion fail to evaluate injury because they fail to distinguish interactions between the human and the space suit. Contact pressure sensing would allow a quantitative assessment of the nature and location of suit-body contact where injuries occur. However, commercially available systems are not well suited for measurement inside the confined environment of the space suit during movement. We report on the design of a wearable pressure sensing system, the Polipo. The Polipo dynamically measures between 5 and 60 kPa of pressure with $\sim 1$ kPa sensitivity, is within 10% root mean square error from a known loading profile during dynamic movement, and is a standalone system able to accommodate a 50th percentile female to a 95th percentile male upper body dimensions with near shirt-sleeve mobility. This paper focuses on the upper body, but the methods may be extended to the full body as future work. It provides a pressure sensing system that could be applied beyond the field of aerospace to assess human–garment interactions, for example recommending armor protection for defense applications or to alleviate fall impacts for medical applications.
Model for the Intrusion of Batholiths Associated with the Eruption of Large-Volume Ash-Flow Tuffs

Pyroclastic eruption and the intrusion of batholiths associated with large-volume ash-flow tuffs may be driven by a decrease in reservoir pressure caused by the low density of the magma column due to vesiculation. Batholithic intrusion would then be accomplished by the subsidence and settling of kilometer-sized crustal blocks through the magma chamber, resulting in eventual collapse to form large caldera structures at the surface. Such a model does not require the formation of a large, laterally extensive, shallow magma chamber before the onset of large-volume ash-flow eruptions. Eruption could commence directly from a deeper reservoir, with only a small channelway being opened to the surface before the onset of catastrophic ash-flow eruptions of the scale of Yellowstone or Long Valley. Such a model has wide-ranging implications, and explains many of the problems inherent in the simple collapse model involving shallow magna chambers as well as the process and timing of batholith intrusion in such cases.
Characterization of a large gene family in Schistosoma japonicum that encodes an immunogenic miracidial antigen

Three of eleven clones isolated from a genomic expression library of Schistosoma japonicum DNA using chronically infected human sera also react with chronically infected mouse sera. Characterization of these three clones showed that they contain different members of the same gene family. One clone contains two members of the gene family approximately 2 kb apart and in opposite orientation to each other. DNA sequence homologies between pairs of genes range from 98% to 99.5%. Southern hybridization results indicate there are approximately 40 copies of these genes per haploid genome. Sera from mice immunized with purified fusion protein detected immunoreactive products in the central ganglion and ciliated epidermal cells of miracidia.
Parallel Implementation of a Low Order Algorithm for Dynamics of Multibody Systems on a Distributed Memory Computing System

In this paper, a new hybrid parallelisable low order algorithm, developed by the authors for multibody dynamics analysis, is implemented numerically on a distributed memory parallel computing system. The presented implementation can currently accommodate the general spatial motion of chain systems, but key issues for its extension to general tree and closed loop systems are discussed. Explicit algebraic constraints are used to increase coarse grain parallelism, and to study the influence of the dimension of system constraint load equations on the computational efficiency of the algorithm for real parallel implementation using the Message Passing Interface (MPI). The equation formulation parallelism and linear system solution strategies which are used to reduce communication overhead are addressed. Numerical results indicate that the algorithm is scalable, that significant speed-up can be obtained, and that a quasi-logarithmic relation exists between time needed for a function call and numbers of processors used. This result agrees well with theoretical performance predictions. Numerical comparisons with results obtained from independently developed analysis codes have validated the correctness of the new hybrid parallelisable low order algorithm, and demonstrated certain computational advantages.
Effects of Contaminants on Toxicity of the Lampricides TFM and Bayer 73 to Three Species of Fish

Waters in the Great Lakes basin contain more than 400 contaminant chemicals that potentially affect fishery resources, commerce, and human inhabitants. We determined in the laboratory the effects of selected contaminants on the toxicity of the widely used lampricides TFM (3-trifluoromethyl-4-nitrophenol) and Bayer 73 (2′,5-dichloro-4′-nitrosalicylanilide) to three species of fish—rainbow trout (Salmo gairdneri), white sucker (Catostomus commersoni), and fathead minnow (Pimephales promelas). The fish were exposed to paired mixtures of lampricides and selected contaminants in standardized, acute static toxicity tests to determine the resulting type of response—less than additive, additive, or greater than additive (synergistic). As expected, the toxicities of combinations of lampricides with organic pesticides, metal, industrial or municipal pollutants, and tannic acid were mostly additive. However, the toxicity of a combination of TFM, Delnav, and malathion was synergistic, and extremely small quantities of each chemical became lethal when mixed. The concentration that produced 50% mortality was 1.64 mg/L for TFM alone but only 0.041 mg/L for TFM with the pesticides. Toxicities of the pesticides in the combination also increased commensurately. The triple combination of chemicals produced extraordinary synergism and effectively demonstrated the hazards that may result if certain chemical combinations occur in the aquatic environment. However, synergism is not the only kind of toxic action that produces hazards to aquatic organisms. All three types of toxic action are of concern because toxic units produced by contaminant chemicals add to the toxic units of applied management chemicals. Since the toxicity of the majority of chemical combinations is simply additive, this cumulative toxic action contributes more total units to aquatic environments than the extreme actions of less than additive and synergism. The toxicity of the lampricide TFM, as well as other management chemicals, is reinforced by the presence of any contaminant that contributes additional units of toxicity. Therefore, all types of cumulative toxic action should be of concern to people and agencies involved with protecting the environment.
Effects of calcitonin on electrolyte excretion in the lizard Dipsosaurus dorsalis

Abstract The effects of salmon calcitonin (sCT) on nasal salt gland secretion and on the renal excretion of Ca, inorganic phosphate (P), Na, and K were investigated in the lizard Dipsosaurus dorsalis . Intact lizards were given either 10 units sCT/kg body mass, ip, or vehicle ( n = 8). Ureteral urine was collected continuously for a 2-hr control period prior to administration of treatments, and then for two 2-hr periods thereafter. Blood was collected prior to dosing and at the end of each urine collection period. sCT had no effect on plasma Ca, P, Na, or K. Renal function parameters (including urinary excretion of Ca, P, Na, and K) were not significantly altered by the administration of sCT. sCT caused no change in electrolyte composition of secretions from the nasal salt gland. In summary, calcitonin does not appear to have a major role in kidney and salt gland mediated regulation of Ca, P, Na, or K in this species.
Pericarp Thickness and Other Kernel Physical Characteristics Relate to Microwave Popping Quality of Popcorn

The popping performance of 18 popcorn hybrids was studied using 2 microwave treatments, with and without salt, and 1 conventional method. Differences in popping quality indices between the 2 microwave treatments, indicated a negative effect of salt on popping for the majority of hybrids. Pericarp thickness, kernel volume, sphericity, diameter ratio, thousand kernel weight, hardness, and density were investigated. Pericarp thickness gave highest correlation with expansion volume in microwave and conventional popping while sphericity correlated slightly better in unsalted microwave popping. Regression models, which predict expansion volume in terms of pericarp thickness and kernel shape and size, were developed for both microwave and conventional popping.
Pitfalls in Clinical Recognition and a Novel Operative Approach for Hypertrophic Cardiomyopathy With Severe Outflow Obstruction Due to Anomalous Papillary Muscle

Background—Ventricular septal myotomy/myectomy (Morrow procedure) is the standard surgical option for severely symptomatic patients with hypertrophic cardiomyopathy (HCM) and marked basal obstructi...
Anisotropic surface meshing with conformal embedding

This paper introduces a parameterization-based approach for anisotropic surface meshing. Given an input surface equipped with an arbitrary Riemannian metric, this method generates a metric-adapted mesh with user-specified number of vertices. In the proposed method, the edge length of the input surface is directly adjusted according to the given Riemannian metric at first. Then the adjusted surface is conformally embedded into a parametric 2D domain and a weighted Centroidal Voronoi Tessellation and its dual Delaunay triangulation are computed on the parametric domain. Finally the generated Delaunay triangulation can be mapped from the parametric domain to the original space, and the triangulation exhibits the desired anisotropic property. We compute the high-quality remeshing results for surfaces with different types of topologies and compare our method with several state-of-the-art approaches in anisotropic surface meshing by using the standard measurement criteria.
Think Globally, Act Locally

ThisspecialissueoftheJournalofClinicalOncologyisdevoted not to the elimination of global warming, but to advances in the local therapy of cancer. There are a number of reasons for us to be concerned about local control. The simplest is surgical resection alone cures many thousands of patients with early-stage cancers each year. In addition, there is now strong evidence from randomized trials that demonstrate that other local therapies (especially when combined with chemotherapeutic agents used as sensitizers) can lead to long-term survival for patients with locally advanced cancers, including gliomas, head and neck, lung, cervix, and prostate (in the case of radiation therapy), and liver (in the case of chemoembolization or radiofrequency ablation). In other instances, improvements in local therapy permit healthy tissue to be spared, such as avoiding xerostomia in the treatment of head and neck cancer, breast conservation in the treatment of breast cancer, andsphinctersparingsurgeryforrectalcancer.Thus,althoughitis truethatmanypatientswillsuccumbtosystemicdisease,improvementsinlocaltherapyhavethepotentialtoimproveboththesurvival and quality of life of many patients who develop malignancies. This special issue begins with a series of articles on how state-ofthe-artradiationtherapyandinterventionalradiologyisadministered in 2007. Our goal in soliciting these articles was to describe the key principles of these approaches, so as to better appreciate the framework of these fields. The last set of articles focuses on specific disease sites so as to illustrate how these principles of local therapy have been applied to improve the outcome of treatment. TheissuebeginswithadiscussionbyDrsGalvinandDeNeve 1
Monoclonal antibodies to the cockroach nervous system.

In the cockroach nervous system individual motor neurons may be identified with respect to their position. in the thoracic ganglia and to the muscles they innervate. When their axons are cut they have the ability to regrow such that when regeneration is completed they have specifically reinnervated their normal target muscles. This suggests the existence of a specific intercellular recognition process between motor neurons and muscles, and that neurons innervating different muscles are biochemically distinct from one another. The goal of this study was to use hybridoma techniques to obtain monoclonal antibodies that bind to some motor neurons and not others. Mice were injected with whole nerve cord and hybridoma supernatants were screened immunohistochemically on sections of ganglion and leg muscle. The monoclonal antibodies were categorized according to four types of specificity: tissue, regional, cell-type, and neuron-subset specificities. Antibodies expressing neuron-subset specificity were obtained very rarely. The probability of their occurrence could be increased by treating the mice with immunosuppressant drugs after initial administration of immunogen or by fixing the immunogen with paraformaldehyde in a manner similar to that of the tissue sections used in the screening process. Two of the neuron-subset specific monoclonal antibodies (MAbs) are of particular interest with respect to the goals of this study. They bind to axon terminals in the muscles of some neurons and not others. They do not bind to neuronal cell bodies in the ganglion, which makes identification of the neurons difficult. However, from the known innervation pattern of the coxal depressor muscles it appears that one of these MAbs selectively binds to axon terminals from either the inhibitory motor neurons or the dorsal unpaired median cells. Other antibodies of interest bind selectively to the synapse-rich neuropile in the ganglia or to peripheral parts of the nervous system like the nerve roots.
Molecular characterization of pdc2 and mapping of three pdc genes from rice

The anaerobic fermentation pathway is thought to play an important role under flooding conditions. The pyruvate decarboxylase 2 (pdc2) gene that encodes the first enzyme of this pathway has been cloned and characterized from rice. This gene has an open reading frame that putatively encodes a 603 amino-acid-residue protein with a molecular mass of 64 kDa. pdc2 has five introns dispersed throughout the coding region, which is also true for rice pdc1. Although the length of these introns in rice pdc2 are different from those in rice pdc1, they are located in exactly the same positions based on the deduced amino-acid sequences. The temporal and spatial expression patterns of pdc1 and pdc2 show that pdc2 is induced to a higher level during the early period (1.5–12 h) of anoxia than pdc1, which is induced more after longer time periods (24–72 h) of anoxia in both shoots and roots. The map positions of the three pdc genes have also been determined. Rice pdc1 is located on chromosome 5 between BCD454A and RZ67, pdc2 is located on chromosome 3 between RZ329 and RZ313, and pdc3 is mapped on chromosome 7 distal to RG351.
Facing Kenya's energy predicament

Abstract Kenya's economic future looks bleak - and it is not helped by its dependence on foreign oil and lack of fossil fuel reserves. At a conference on Kenya's energy needs, held in May 1979, options for averting a fuel—food crisis were considered. Here Philip O'Keefe and Don Shakow describe the main themes of that conference and discuss the basis for a Kenyan energy policy.
Effect of Indomethacin on the Hypothalamic-Pituitary-Adrenal Axis in Man

The effect of the cyclo-oxygenase inhibitor, indomethacin, on hypothalamic-pituitary-adrenal function was investigated in five normal males. Baseline 0800 and 1600 h plasma ACTH and cortisol, plasma ACTH and 11-deoxycortisol responses to metyrapone, and plasma cortisol responses to dexamethasone and exogenous ACTH were not affected by indomethacin. However, the area under the curve for plasma ACTH after iv injection of regular insulin (0.1 U/kg) was significantly decreased during indomethacin administration (control, 88.0 ± 32.6 cm2, mean ± SD; indomethacin, 47.6 ± 23.1, P < 0.01). Plasma cortisol levels were decreased only at 30 min. Our results support the hypothesis that prostaglandins or any of their precursors play a role in the hypothalamic control of ACTH secretion and indicate that evaluation of hypophyseal ACTH secretory capacity by means of insulin-induced hypoglycemia may yield abnormal results in patients receiving indomethacin.
SU-8 Processing on a Variety of Substrates

SU-8 has become a popular material for micromachining high aspect ratio structures. Typically, SU-8 is spun on a polished silicon wafer for processing. After patterning, the SU-8 is used for micromachined structures directly (such as fluidic channels) or as a mold for electroforming. Non-silicon substrates offer the possibility of cheaper processing, improved mold designs, and multi-material devices. Successful SU-8 processing depends strongly on surface properties of the substrate itself as well as environmental conditions during the processing. We explore the issues involved in transferring SU-8 technology to non-silicon substrates such as glass, plastics and metals. Issues such as wettability, adhesion, and surface tension are explored in this study. The findings indicate the merits of non-spinning approaches, such as dipping, spraying, and brushing and point to new SU-8 processes.
Duration of Preventive Antibiotic Administration for Penetrating Abdominal Trauma

• Eighty-two patients with penetrating abdominal trauma and visceral injuries requiring laparotomy were prospectively randomized to receive either 12 hours or five days of penicillin G potassium and doxycycline hyclate beginning before operation. Distribution between groups was equivalent for all risk factors except shock, which was more prevalent in the 12-hour group. Antibiotics were first administered an average of 64 minutes following injury, and 90% of all patients had received antibiotics and were being operated on within 3 hours 15 minutes. Overall infection rates were 17% in patients with colon penetration, 14% in patients without colon penetration but with other intestinal penetration, and 0% in patients without intestinal penetration. Twelve-hour and five-day antibiotic regimens were comparable in the prevention of postoperative infectious complications following penetrating abdominal injuries. Intestinal penetration was the most important risk factor for development of infectious complications in this patient population. ( Arch Surg 1982;117:200-205)
Underwater Acoustic Navigation Using a Beacon With a Spiral Wave Front

In this paper, a method for performing underwater acoustic navigation using a spiral wave-front beacon is examined. A transducer designed to emit a signal whose phase changes by 360 $^{\circ}$ in one revolution can be used in conjunction with a reference signal to determine the aspect of a remote receiver relative to the beacon. Experiments are conducted comparing spiral wave-front beacon navigation to Global Positioning System (GPS) onboard an unmanned surface vehicle. The advantages and disadvantages of several outgoing signals and processing techniques are compared. The most successful technique involves the use of a phased array projector utilizing a broadband signal. Aspect is determined by using a weighted mean over frequencies. Sources of error for each of the techniques are also examined.
Restoration of spermatogenesis and male fertility using an androgen receptor transgene.

Androgens signal through the androgen receptor (AR) to regulate male secondary sexual characteristics, reproductive tract development, prostate function, sperm production, bone and muscle mass as well as body hair growth among other functions. We developed a transgenic mouse model in which endogenous AR expression was replaced by a functionally modified AR transgene. A bacterial artificial chromosome (BAC) was constructed containing all AR exons and introns plus 40 kb each of 5' and 3' regulatory sequence. Insertion of an internal ribosome entry site and the EGFP gene 3’ to AR allowed co-expression of AR and EGFP. Pronuclear injection of the BAC resulted in six founder mice that displayed EGFP production in appropriate AR expressing tissues. The six founder mice were mated into a Sertoli cell specific AR knockout (SCARKO) background in which spermatogenesis is blocked at the meiosis stage of germ cell development. The AR-EGFP transgene was expressed in a cyclical manner similar to that of endogenous AR in Sertoli cells and fertility was restored as offspring were produced in the absence of Sertoli cell AR. Thus, the AR-EGFP transgene under the control of AR regulatory elements is capable of rescuing AR function in a cell selective, AR-null background. These initial studies provide proof of principle that a strategy employing the AR-EGFP transgene can be used to understand AR functions. Transgenic mice expressing selective modifications of the AR-EGFP transgene may provide crucial information needed to elicit the molecular mechanisms by which AR acts in the testis and other androgen responsive tissues.
N-port synthesis of N-order positive entry resistance matrices

Abstract New relationships between n-order positive entry resistance matrices of graphs of nullity n and network topology are established. A method of decomposition of positive entry resistance matrices into a sum of simple resistance matrices is given, and a number of necessary conditions for synthesis as a transformerless n-port are proven. A procedure to synthesize symmetric, positive entry matrices of order n as resistance matrices of graphs of nullity n is developed and illustrated.
EFFECT OF LIPASE SPECIFICITY ON TRIGLYCERIDE SYNTHESIS

Enzymatic triglyceride synthesis from free fatty acid and glycerol is shown to be catalysed by both 1,3-specific lipase and non-specific lipase. This paper elucidates the mechanism of the reaction, showing that, with a 1,3-specific lipase, the 1,3-diolein enzymatically formed has to isomerise spontaneously to 1,2-diolein in presence of oleic acid, before being transformed to triolein by the enzyme.
The movement and decay of ice edge bands in the winter Bering Sea

A study of the movement and decay of ice bands in the Bering Sea carried out in March 1981 is described. A pair of radio transponders mounted on ice floes within a band was tracked and the band motion was compared with that of a satellite-tracked buoy deployed in the ice interior. The results show that the bands moved away from the interior pack ice at a speed 30 percent greater than that of the interior ice, that the cause of this band acceleration was very likely the wind-wave radiation stress on the upwind side of the band, and that as the bands moved into warmer water, they decayed both by wind-wave erosion of the upwind edge and by bottom melting. The working of the buoys and the method of deployment are described, as are the band shape, trajectory, and decay. By a calculation of the steady state stress balance on the band, it is shown that the radiation stress can account for the velocity increase of the band relative to the ice interior.
Lesbians in (cyber)space: the politics of the internet in Latin American on- and off-line communities

Living in societies that use law, mainstream media and social opprobrium to deny their enjoyment of basic rights – and sometimes their very existence – Latin American lesbians have long relied on alternative ways of expressing and associating themselves. In the late 1990s, they adopted a powerful new tool that is also a'virtual' space: the internet, or cyberspace. This article argues that cyberspace – the dense web of information and communication created by email, chat, distribution lists and websites – is a virtual public sphere especially useful for Latin American lesbian communities. The internet addresses the central problems impeding the effectiveness of lesbian organizing: isolation, repression, resource restriction and lack of community cohesion. Despite the opportunities cyberspace offers, it presents new challenges for organizers, from an increase in responsibilities to an erosion of political accountability. Nevertheless, the contributions of the internet far outweigh the complications it brings.
An experimental investigation of efficient rent-seeking*

The debate about the measurement of the amount of rent dissipated in rent-seeking activities is unable to be answered by observations from the naturally occurring environment. Current theoretical investigations have indicated that a number of factors will affect the amount of rent that can be assumed to be dissipated by rent-seeking. The theory of efficient rent-seeking predicts that the number of rent-seekers, their risk posture, their ability to enter and exit the rent-seeking process, and the manner in which the probability of receiving a rent is determined will affect the amount of rent that is dissipated.
Effect of Different Cooking Methods on Vegetable Oxalate Content

Approximately 75% of all kidney stones are composed primarily of calcium oxalate, and hyperoxaluria is a primary risk factor for this disorder. Nine types of raw and cooked vegetables were analyzed for oxalate using an enzymatic method. There was a high proportion of water-soluble oxalate in most of the tested raw vegetables. Boiling markedly reduced soluble oxalate content by 30-87% and was more effective than steaming (5-53%) and baking (used only for potatoes, no oxalate loss). An assessment of the oxalate content of cooking water used for boiling and steaming revealed an approximately 100% recovery of oxalate losses. The losses of insoluble oxalate during cooking varied greatly, ranging from 0 to 74%. Because soluble sources of oxalate appear to be better absorbed than insoluble sources, employing cooking methods that significantly reduce soluble oxalate may be an effective strategy for decreasing oxaluria in individuals predisposed to the development of kidney stones.
AREDS Formula, Warfarin, and Bleeding: A Case Report from the Michigan Anticoagulation Quality Improvement Initiative

Importance. The anticoagulant warfarin has been shown to interact with other medications, vitamin K containing foods, and over-the-counter products. These interactions may inhibit or potentiate the effect of warfarin, resulting in serious clotting or bleeding events. Observations. We report the case of an 84-year-old woman with atrial fibrillation, prescribed warfarin in May 2010 for stroke prevention. Her international normalized ratio (INR) was stable until April 2013, when she was prescribed AREDS (Age Related Eye Disease Study) formula pills, an eye vitamin compound, to slow the progression of age-related macular degeneration. This change was not reported to the Anticoagulation Service. Eighteen days later, she presented to the ED with groin and back pain and an INR of 10.4. An abdominal CT revealed a retroperitoneal hemorrhage with extension in multiple muscles. Both warfarin and AREDS were discontinued and the patient was discharged to subacute rehabilitation. This case was reviewed by the Anticoagulation Service and actions were taken to prevent similar adverse events. Conclusions. This report provides an example of the potential danger of supplement use, in this case, AREDS formula, in patients prescribed warfarin, and the importance of communicating medication changes to the providers responsible for warfarin management.
Recognition of the highly conserved GTPase center of 23 S ribosomal RNA by ribosomal protein L11 and the antibiotic thiostrepton

The antibiotic thiostrepton, a thiazole-containing peptide, inhibits translation and ribosomal GTPase activity by binding directly to a limited and highly conserved region of the large subunit ribosomal RNA termed the GTPase center. We have previously used a filter binding assay to examine the binding of ribosomal protein L11 to a set of ribosomal RNA fragments encompassing the Escherichia coli GTPase center sequence. We show here that thiostrepton binding to the same RNA fragments can also be detected in a filter binding assay. Binding is relatively independent of monovalent salt concentration and temperature but requires a minimum Mg2+ concentration of about 0.5 mM. To help determine the RNA features recognized by L11 and thiostrepton, a set of over 40 RNA sequence variants was prepared which, taken together, change every nucleotide within the 1051 to 1108 recognition domain while preserving the known secondary structure of the RNA. Binding constants for L11 and thiostrepton interaction with these RNAs were measured. Only a small number of sequence variants had more than fivefold effects on L11 binding affinities, and most of these were clustered around a junction of helical segments. These same mutants had similar effects on thiostrepton binding, but more than half of the other sequence changes substantially reduced thiostrepton binding. On the basis of these data and chemical modification studies of this RNA domain in the literature, we propose that L11 makes few, if any, contacts with RNA bases, but recognizes the three-dimensional conformation of the RNA backbone. We also argue from the data that thiostrepton is probably sensitive to small changes in RNA conformation. The results are discussed in terms of a model in which conformational flexibility of the GTPase center RNA is functionally important during the ribosome elongation cycle.
Effects of estradiol-17β, para-chlorophenylalanine and quipazine on tonic and LHRH-induced secretion of luteinizing hormone in ovariectomized ewes

Abstract Changes in metabolism of serotonin (5-HT) might mediate the reduced tonic luteinizing hormone (LH) and increased pituitary responsiveness to luteinizing hormone releasing hormone (LHRH) caused by estradiol-17β (estradiol). Two experiments were conducted to determine effects of estradiol, para-chlorophenylalanine (PCPA), an inhibitor of synthesis of 5-HT, and quipazine, an agonist of 5-HT, on tonic and LHRH-induced secretion of LH in ovariectomized ewes during the summer. Tonic levels of LH were reduced, the interval from LHRH to peak of the induced surge was longer and the magnitude of release of LH was greater in ovariectomized ewes treated with estradiol than in controls. Neither PCPA nor quipazine affected tonic secretion of LH. In ovariectomized ewes not receiving estradiol, PCPA and quipazine increased the magnitude of the LHRH-induced release of LH. However, PCPA reduced pituitary sensitivity to LHRH when administered concomitantly with estradiol; treatment with quipazine attenuated this effect of PCPA. The interval to the peak of the induced surge of LH was not affected by PCPA or quipazine in estradiol-treated or control ovariectomized ewes. Based on these results it appears that 5-HT mediates or is required for estradiol to increase pituitary responsiveness to LHRH.
Lessons Learned From the Evacuation of an Urban Teaching Hospital

Hypothesis Valuable lessons can be learned from the emergent evacuation of a large urban teaching hospital because of flooding. Design Case report. Setting Four hundred fifty–bed adult and 150-bed children's tertiary referral teaching hospital. Case Summary Massive rainfall from tropical storm Allison caused extensive flooding. Emergency power came on at 1:40 AM. Complete power loss occurred at 3:30 AM. The decision to begin evacuation of patients was made at approximately 10:30 AM. All 575 patients were either discharged from the hospital (169 patients) or evacuated (406 patients) to 29 other facilities by both ambulance and helicopter by 3 PM the next day. Six deaths occurred, none of which could be attributed to the conditions created by the flooding. Conclusions The lessons learned from this experience included the following: (1) flooding will occur in a flood plain; (2) electrical power outages are not necessarily temporary—begin evacuation; (3) appoint a triage officer from those available; (4) have a reliable in-house communication system not dependent on telephone lines or electricity; (5) have a reliable telephone system for contacting outside facilities; (6) have flashlights available on all units; (7) have battery-operated exit signs and stairway lights; (8) maximize use of volunteers when they are available and fresh; (9) maintain a paper record of all patient transfers; (10) coordinate loading of ambulances and helicopters for patient transfer; and (11) reassign staff as necessary to care for transferred patients. Emergent evacuation of a large, tertiary hospital requires extensive effort from both the hospital staff and the community.
Comprehensive Evaluation of Feedback-Based Freeway Ramp-Metering Strategy by Using Microscopic Simulation: Taking Ramp Queues into Account

One of the major criticisms of ramp metering has been delay caused on the ramps because of the queues created by ramp control strategies. Recently, several researchers proposed strategies that explicitly consider ramp queues when metering rates are determined. An isolated "feedback"-based ramp-metering strategy (mixed control) is presented. In addition to regulation of ramp input from the freeway, the strategy calls for regulation of ramp queues by explicitly incorporating them into the model. Mixed control is tested using PARAMICS, a microscopic traffic simulation package, on a calibrated test network located in Hayward, California. In addition to mixed control, ALINEA and new control are implemented. Because the focus here is on evaluation of isolated ramp control strategies, change in demand caused by ramp metering is not considered. The system is defined as the upstream, downstream, and ramp links around the metered ramp. The performance of two freeway demand patterns (congested and overcongested) is ...
The modulation of coupled relaxation in porous media.

Abstract This work investigates the effects of modulation of the transverse and longitudinal relaxation of the surface-fluid/pore-fluid spin system in porous media. Important new NMR well logging applications identify pore fluids by varying the CPMG T 2 pulse spacing to discriminate on the basis of fluid diffusivities in applied and local static magnetic field gradients. However, anomalous laboratory CPMG T 2 results have been reported repeatedly over 25 years for various porous media filled with a single fluid. In relatively large pores, at near bulk conditions, the transverse relaxation of diffusing molecular spins should be proportional to the square of the CPMG pulse spacing τ, the susceptibility contrast at the pore wall and the applied gradient. Observed is a markedly linear τ dependence that saturates at a plateau for large τ. The effect is not quadratic in applied gradient or susceptibility. For large pores, the τ dependence and the saturation value are proportional to the surface-to-volume ratio of the pores. This is in distinct contrast to the behavior observed by Borgia, Brown and Fantazzini for systems with much smaller pores at higher magnetic fields. The large-pore anomalous behaviors can be explained as a modulation of the exchange between surface-fluid and pore-fluid spins, such as observed by Luz and Meiboom in 1963 for water enriched with quadrupolar 17 O. Scalar coupling of the solid-surface spins to the fluid-surface spins was postulated by Kleinberg, Kenyon and Mitra as a dominant relaxation mechanism for the surface fluid. The CPMG τ effect can be described as the modulation of the exchange coupling by the CPMG π pulses, which mix the magnetizations between the exchanging, strongly coupled spin systems of the pore-fluid and the surface-fluid, which is, in turn, weakly coupled by scalar or pseudo-scalar interactions to the fast-relaxing solid surface.
The design and implementation of a SOA-based educational resource services system

With the rapid development of information technology, educational resource systems are in widespread use. For the reuse and sharing of resources and function modules, this paper designs the framework of a SOA-Based Educational Resource Services System, and presents its implementation. Besides the common characteristics of SOA, the system is flexible and scalable.
The highly damped quasinormal modes of extremal Reissner–Nordström and Reissner–Nordström–de Sitter black holes

We analyze in detail the highly damped quasinormal modes of D-dimensional extremal Reissner–Nordstrom and Reissner–Nordstrom–de Sitter black holes. We only consider the extremal case where the event horizon and the Cauchy inner horizon coincide. We show that, even though the topology of the Stokes/anti-Stokes lines in the extremal case is different than the non-extremal case, the highly damped quasinormal mode frequencies of extremal black holes match exactly with the extremal limit of the non-extremal black hole quasinormal mode frequencies.
Zar1 represses translation in Xenopus oocytes and binds to the TCS in maternal mRNAs with different characteristics than Zar2.

Maternal mRNAs are translationally regulated during early development. Zar1 and its closely related homolog, Zar2, are both crucial in early development. Xenopus laevis Zygote arrest 2 (Zar2) binds to the Translational Control Sequence (TCS) in maternal mRNAs and regulates translation. The molecular mechanism of Zar1 has not been described. Here we report similarities and differences between Xenopus Zar1 and Zar2. Analysis of Zar sequences in vertebrates revealed two Zar family members with conserved, characteristic amino acid differences in the C-terminal domain. The presence of only two vertebrate Zar proteins was supported by analyzing Zar1 synteny. We propose that the criteria for naming Zar sequences are based on the characteristic amino acids and the chromosomal context. We also propose reclassification of some Zar sequences. We found that Zar1 is expressed throughout oogenesis and is stable during oocyte maturation. The N-terminal domain of Zar1 repressed translation of a reporter construct in immature oocytes. Both Zar1 and Zar2 bound to the TCS in the Wee1 and Mos 3′ UTRs using a zinc finger in the C-terminal domain. However, Zar1 had much higher affinity for RNA than Zar2. To show the functional significance of the conserved amino acid substitutions, these residues in Zar2 were mutated to those found in Zar1. We show that these residues contributed to the different RNA binding characteristics of Zar1 compared to Zar2. Our study shows that Zar proteins have generally similar molecular functions in the translational regulation of maternal mRNAs, but they may have different roles in early development.
A simple micro infrared technique

With the aid of a beam condenser, a method was developed yielding full scale deflexion curves of micro samples. A commercially available steel disk which supported the prepared sample matrix was pressed between two steel cylinders. Best results were obtained from crystalline samples.
Accurate simplified dynamic model of a metal hydride tank

Abstract As proton exchange membrane fuel cell technology advances, the need for hydrogen storage intensifies. Metal hydride alloys offer one potential solution. However, for metal hydride tanks to become a viable hydrogen storage option, the dynamic performance of practical tank geometries and configurations must be understood and incorporated into fuel cell system analyses. A dynamic, axially-symmetric, multi-nodal metal hydride tank model has been created in Matlab–Simulink ® as an initial means of providing insight and analysis capabilities for the dynamic performance of commercially available metal hydride systems. Following the original work of Mayer et al. [Mayer U, Groll M, Supper W. Heat and mass transfer in metal hydride reaction beds: experimental and theoretical results. Journal of the Less-Common Metals 1987;131:235–44], this model employs first principles heat transfer and fluid flow mechanisms together with empirically derived reaction kinetics. Energy and mass balances are solved in cylindrical polar coordinates for a cylindrically shaped tank. The model tank temperature, heat release, and storage volume have been correlated to an actual metal hydride tank for static and transient absorption and desorption processes. A sensitivity analysis of the model was accomplished to identify governing physics and to identify techniques to lessen the computational burden for ease of use in a larger system model. The sensitivity analysis reveals the basis and justification for model simplifications that are selected. Results show that the detailed and simplified models both well predict observed stand-alone metal hydride tank dynamics, and an example of a reversible fuel cell system model incorporating each tank demonstrates the need for model simplification.
An Unusual Cause for Mitral Valve Fluttering

A 23-year-old patient with patent ductus arteriosus had coarse diastolic fluttering of the mitral valve leaflets on the echocardiogram in the absence of usual causes.