cssi/SciSciGPT-SciSciNet huggingface dataset:
Electrical engineering education for the future

THE ULTIMATE DESTINY of Western Civilization, indeed its very survival, is now in direct ratio to the quality and quantity of its technology. This, in turn, is measurably related to engineering education in general, and to electrical engineering education in particular, by reason of the central role of electricity in the modern world. These are historic realities of the present day, acknowledged by all thoughtful leaders in and out of Government.
Surgery for small cell lung cancer

The role of surgery for small cell lung cancer (SCLC) has been hotly contested over the past 20 years. Despite misgivings promoted by the failure of surgery to control disease as documented by a report of the British Medical Research Council in 1969 [1], surgeons continued to operate on SCLC. It soon became apparent that in stage I (T1N0, T2N0) disease, surgical therapy alone can provide curative treatment in up to 50% of patients. With the addition of postoperative chemotherapy, it appears that in this early stage of disease, even better long-term survival may be possible [2].
Neurochemical hypothesis: participation by aluminum in producing critical mass of colocalized errors in brain leads to neurological disease.

Abstract 1. 1. Aluminum is an established neurotoxin. Prolonged exposure to even low levels of aluminum permit its chelation and subsequent transport to brain where it is non-uniformly distributed. 2. 2. Available evidence suggests that (i) aluminum interferes with glucose metabolism by inhibiting hexokinase and glucose-6-phosphate dehydrogenase; (ii) it binds to calmodulin and affects numerous phosphorylation-dephosphorylation reactions; (iii) it binds to transferrin and ferritin, affects the function of these proteins which in turn affect iron metabolism. 3. 3. Thus accumulation of aluminum-induced metabolic errors colocalized in specific areas of the brain may lead to neurological disorders.
On Some Ridge Regression Estimators: An Empirical Comparisons

In ridge regression analysis, the estimation of the ridge parameter k is an important problem. Many methods are available for estimating such a parameter. This article reviewed and proposed some estimators based on Kibria (2003) and Khalaf and Shukur (2005). A simulation study has been made and mean squared error (MSE) criteria are used to compare the performances of the estimators. We observed that under certain conditions some of the proposed estimators performed well compared to the ordinary least squared (OLS) estimator and some existing popular estimators. Finally, a numerical example has been considered to illustrate the performance of the estimators.
Temperature-pressure studies on magnesium-activated adenosinetriphosphatase from skeletal muscle.

Abstract The effects of pressure, temperature, and pH on the activity of purified rabbit skeletal muscle magnesium-activated ATPase were measured. The enzyme is rapidly and irreversibly inactivated by both temperature and pressure and shows no evidence of reversible denaturation. The extent of irreversible inactivation depends on the amount of pressure applied and is largest at the optimum pH of the enzyme.
Molecular Structure and Dynamics in Thin Water Films at Metal Oxide Surfaces: Magnesium, Aluminum, and Silicon Oxide Surfaces

All-atom equilibrium molecular dynamics simulations were employed to investigate the structural and dynamical properties of interfacial water on the magnesium oxide surface. The solid support was modeled utilizing two different formalisms, both based on the CLAYFF force field. In one case, the atoms in the MgO substrate are allowed to vibrate, whereas in the other they are maintained rigid. The properties of water within the thin film are assessed in terms of density profiles in the direction perpendicular to the substrate as well as along planes parallel to the substrate, in-plane radial distribution functions, density of hydrogen bonds, residence times in contact with the substrate, and orientation distribution of interfacial water molecules. The contact angle for a small droplet on various substrates (MgO, SiO2, Al2O3) was also calculated and compared with experimental observations. On MgO, the substrate in which the atoms are maintained fixed is the one that most closely reproduces experimental contac...
The auction algorithm: a distributed relaxation method for the assignment problem

We propose a massively parallelizable algorithm for the classical assignment problem. The algorithm operates like an auction whereby unassigned persons bid simultaneously for objects thereby raising their prices. Once all bids are in, objects are awarded to the highest bidder. The algorithm can also be interpreted as a Jacobi — like relaxation method for solving a dual problem. Its (sequential) worst — case complexity, for a particular implementation that uses scaling, is O(NAlog(NC)), where N is the number of persons, A is the number of pairs of persons and objects that can be assigned to each other, and C is the maximum absolute object value. Computational results show that, for large problems, the algorithm is competitive with existing methods even without the benefit of parallelism. When executed on a parallel machine, the algorithm exhibits substantial speedup.
Computing complete answers to queries in the presence of limited access patterns

Abstract.In data applications such as information integration, there can be limited access patterns to relations, i.e., binding patterns require values to be specified for certain attributes in order to retrieve data from a relation. As a consequence, we cannot retrieve all tuples from these relations. In this article we study the problem of computing the complete answer to a query, i.e., the answer that could be computed if all the tuples could be retrieved. A query is stable if for any instance of the relations in the query, its complete answer can be computed using the access patterns permitted by the relations. We study the problem of testing stability of various classes of queries, including conjunctive queries, unions of conjunctive queries, and conjunctive queries with arithmetic comparisons. We give algorithms and complexity results for these classes of queries. We show that stability of datalog programs is undecidable, and give a sufficient condition for stability of datalog queries. Finally, we study data-dependent computability of the complete answer to a nonstable query, and propose a decision tree for guiding the process to compute the complete answer.
Membrane effects of imidoesters in hereditary stomatocytosis

The marked increase in cation (Na+, K+) permeability that results in swollen, cup-shaped red cells in the hereditary stomatocytosis syndrome can be corrected in vitro with a bifunctional crosslinking reagent, dimethyl adipimidate (DMA). 45Ca influx in intact RBC, 45Ca efflux in red ghosts, and 45Ca retention in red ghosts are normal and not influenced by DMA. Endocytosis in resealed red ghosts is strikingly impaired but becomes normal if cells are first treated with 2 mM DMA. Protein kinase mediated phosphorylation of membrane proteins by AT32P--only 20--40% of normal control values in both shortterm (5 min) and more extended (60 min) incubations--is not improved by DMA. After reaction of 14C-DMA with stomatocytes, radiolabel is found associated with phosphatidyl serine and phosphatidyl ethanolamine and is also widely distributed among membrane proteins. Cation permeability of stomatocytes in corrected at DMA concentrations (1 mM) that result in barely detectable crosslinking of aminophospholipids or proteins, suggesting that either crosslinking of a minor component present in only small quantities or intramolecular (rather than intermolecular) crosslinking is responsible for the permeability effects. DMA, whose maximal crosslinking dimension is 7.3--9 A, is the most effective bifunctional imidoester of those tested. Shorter (dimethyl malonimidate) or longer (dimethylsuberimidate) reagents are either less effective than DMA or totally without effect.
Analysis of suspected trace human remains from an indoor concrete surface.

: This paper describes the sequence of analyses used to determine the nature of a stain located on the floor of room in the former Athens Mental Health and Retardation Hospital in Athens, OH. The location of the stain was reported to be the position in which a decomposing body was discovered on January 11, 1979. The current stain is found to contain strong evidence for both natural decomposition products and deliberate adulteration. Microscopic analyses, solubility tests, FTIR, ICP-OES, pyrolysis-MS, and derivatization GC-MS were consistent in determining the removable parts of the stain to be composed mostly of calcium and sodium salts of free fatty acids, such as palmitic acid, consistent with previous descriptions of adipocere. The free fatty acids could have been formed via known bacterial degradation pathways or via saponification through the basic environment caused through contact with the concrete. To our knowledge, adipocere formation on an exposed indoor environment has not been described before. The stain and concrete also show signs of being chemically modified with an acidic reagent, such as Blu-Lite—a phosphoric acid-based cleaner that was a commonly used cleaner in the building from the time of discovery to the present day. The chemical etching appears to have been restricted to an area resembling the shape of a human body, which is consistent with deliberate adulteration of the appearance of the stain.
Antecedents of Tips and Servers' Ability to Predict Tips in a Restaurant Setting

Abstract This paper reports the results of an exploratory field study on servers' use of categories to predict customers' tipping behavior. The study found that servers employ various customer demographic characteristics to predict tipping, but they were accurate only in part. Managerial implications and future research directions are discussed.
Histomorphologic and immunophenotypic analysis of fibrofolliculomas and trichodiscomas in Birt-Hogg-Dube syndrome and sporadic disease.

Background: Fibrofolliculomas and trichodiscomas are benign dermal neoplasms that likely derive from the mantle of the hair follicle and can occur sporadically or in association with Birt–Hogg–Dube syndrome (BHDS). Little is known about the pathogenesis and immunophenotypic properties of these entities. Methods: We investigated the histomorphologic and immnophenotypic properties of 15 fibrofolliculomas and trichodiscomas in two patients with BHDS and eight with sporadic disease. Results: We found the following: (1) fibrofolliculomas and trichodiscomas occurring in the setting of BHDS show microscopically contiguous histomorphologic features as compared to those occurring sporadically; (2) the immunophenotypic characteristics of syndromic-associated and sporadic types are identical and consist of (3) perifollicular vimentin (+), CD34 (+) and Factor XIII (–) spindle cells. Conclusions: Despite subtle histomorphologic differences, trichodiscomas and fibrofolliculomas are immunophenotypically similar, and are thus likely derived from a similar histogenic precursor. Given the previously reported CD34 (+) immunophenotype of the hair mantle, our findings would support an origin of these lesions from the mantle of the hair follicle. The proliferation of CD34 (+) spindle cells seen in conjunction with these lesions should not be confused with other CD34 (+) dermal entities.
Computer supported novice group critique

Groups of novice critiquers can sometimes provide feedback of the same quality as a single expert. Unfortunately, we do not know how to create systems for novice group critique in design education. We tested whether 4 principles: write-first scripts, critique prompts, interactive critiquing & formative framing, allow us to create systems that combine the advantages of face-to-face and computer-mediated critique. We collected observations and 48 interviews with 12 undergraduate design students who used a computer supported group critique system over 5 critique sessions, analyzed using grounded theory. We found that: (a) the write-first script helped overcome initial learning costs; (b) the interactive critique features created a dual-channel critique that increased the number of critiquers, duration of critique and interactivity; and (c) the system produced a greater volume of useful critique and promoted reciprocity among critiquers. The study provides improved principles for developing computer supported novice group critique systems in design.
A temporal study at the ultrastructural level of the developing pro-oocyte of Drosophila melanogaster

The first pro-oocyte in developing pupal germaria of females grown at 25 ° has been followed at 6 h intervals from its formation at ∼129 h post-ovipostion until Stage 1, to provide an unambiguous temporal order. EM autoradiographs were made of sectioned germaria, scanned at lower magnification for location of the pro-oocyte(s) within the most posterior 16-cell cyst and photographed at higher magnification to show the presence of label indicating DNA replication and synaptonemal complex indicating synapsis in the same pro-oocyte nucleus. Label, detected at 132 h and at all subsequent intervals up to and including 162 h, delimited an S-phase of 30 h and identified this period as premeiotic interphase. Extensive SCs (av. length 50 μm/genome) measured in serial sections at 132 h provide irrefutable evidence that synapsis in Drosophila begins close to both pro-oocyte formation and initiation of premeiotic interphase. Measurements of SCs at 6 h intervals during interphase reveal a sharp increase between 132 and 138 h, a peak length (∼75 μm/genome) at 144 h, a decrease and subsequent plateau (∼ 60 μm/genome) from 150–162 h and a further drop (R~50 μm/genome) at Stage 1. Maximal extension of SC at 144 h coincides with maximal genome response to heat (Grell and Day, 1974) and with midpremeiotic-S. Spherical nodules, detected at ∼ 1/genome between 138 and 150 h would, on the questionable assumption that they are the sites of recombination, provide proof of recombination during early interphase, as genetic evidence strongly implies. Evidence contrary to interpretations of fibrillar material within the nucleus as either precursor of the central region of the SC or sagittal sections of the central element of the SC, is presented. No structure corresponding to the polytene chromocenter was observed.
Inter- and intraobserver reliability of computed tomography in assessment of thoracic pedicle screw placement.

STUDY DESIGN Reliability study of computed tomography imaging in 12 cadaver specimens instrumented with titanium or stainless steel thoracic pedicle screws. OBJECTIVE To evaluate inter- and intraobserver reliability of computed tomography scan in determining the accuracy of thoracic pedicle screw placement and to identify the differences in observers' agreement when viewing stainless steel versus titanium screws. SUMMARY OF BACKGROUND DATA Computed tomography is often used to assess the accuracy of pedicle screw placement. Accuracy of screw placement is important in the thoracic spine where pedicle morphometry increases the difficulty of screw placement (vital structures are at increased risk). The current literature lacks a critical evaluation of computed tomography reliability among observers. METHODS Twelve adult cadavers were instrumented with thoracic pedicle screws. Nine cadavers were instrumented with titanium screws and three with stainless steel screws. The spines were imaged with computed tomography. Three observers used a grading scale to score the extent of pedicle violation and independently scored the placement of each pedicle screw on three separate occasions. Interobserver and intraobserver agreement were determined by using the kappa statistic. RESULTS The mean kappa score for interobserver agreement for all 12 specimens (including titanium and stainless steel screws) was 0.51, which correlates with a moderate degree of agreement. Although the interobserver kappa statistics for titanium (kappa = 0.53) and stainless screws (kappa = 0.44) showed a moderate degree of agreement, the intraobserver reliability was substantial (kappa = 0.63). The mean intraobserver kappa for titanium screws was 0.63 and for stainless steel screws was 0.62. CONCLUSIONS Our data show that interobserver agreement is moderate and intraobserver agreement is substantial when computed tomography is used to assess placement of thoracic pedicle screws. We conclude that computed tomography is reliable for evaluating thoracic pedicle screw placement throughout the thoracic spine.
Epidermotropic Merkel cell carcinoma: a case series with histopathologic examination.

Background Merkel cell carcinoma (MCC), an aggressive malignancy that has been increasing in incidence, rarely presents with an epidermotropic pattern. Objective We conducted an immunohistochemical evaluation of 6 previously unpublished cases of epidermotropic MCC, focusing particularly on the staining characteristics of epithelial membrane antigen and cytokeratin-20 in the hope of providing insight into the mechanism of epidermotropism in MCC. Methods This study is a retrospective evaluation using light microscopy and immunohistochemistry. Results Forty cases of MCC with pathology at Rhode Island Hospital and the Miriam Hospital in Providence, RI, from 1983 through 2009 were reviewed. Following exclusion criteria, 6 patients (5 men, 1 woman) with a mean age of 82.5 years (range, 72-92) demonstrated epidermotropism. Three of 6 patients had MCC of the eyelid. In cases 1, 3, and 6, the perinuclear dot pattern observed with cytokeratin-20 in the epidermotropic MCC cells was less pronounced than the pattern observed in the dermis, and in all 6 of the tumors, the epidermal staining pattern observed with epithelial membrane antigen was not more or less prominent than the staining observed in the dermis. Limitations The small total number of cases of epidermotropic MCC is a limitation. Conclusion The data presented reinforce the differential diagnosis of tumors with an epidermotropic growth pattern and the importance of immunohistochemical staining in the histologic workup of such tumors: squamous cell carcinoma in situ, melanoma, mycosis fungoides, eccrine porocarcinoma, sebaceous carcinoma of the eyelid, mammary and extramammary Paget disease, MCC, and epidermotropic metastases. It is notable that 3 of 6 identified tumors were located on the eyelid; further study of epidermotropic MCC may shed more light on this finding, either as an unusual coincidence or a finding with unexplained significance.
Study of Hierarchical Categorization Using Nonsense Syllables

Most studies examining longer-term memory have used words and concepts without question. Because words and concepts have many previous associations, nonsense syllables were used to ascertain more clearly whether categories in longer-term memory exist independently of an associative base.
High Performances in Continuous-Wave and Q-switch Operation of a Narrow Linewidth Nd:YVO4 Oscillator Using a Volume Bragg Grating

A quasi-single-longitudinal mode Nd:YVO4 oscillator providing up to 11 W CW is presented. In Q-switched regime, up to 1.2 mJ output energy with spectral linewidth narrower than 20 pm at 1kHz repetition rate were obtained.
On a result of Osborn

The structure of certain semiprimitive rings with involution * is determined by imposing conditions on the set of *-symmetric elements and limiting the number of orthogonal *-symmetric idempotents. An associative ring R with unit such that 1/2 E R satisfies condition C (n) if (i) R has an involution * such that each *-symmetric element s of R is nilpotent or some (right) multiple of s is a nonzero *-symmetric idempotent and (ii) R has a set of n nonzero, pairwise orthogonal, *-symmetric idempotents whose sum is one and if { e1)7=I is any set of such idempotents whose sum is one, then m < n. We will determine the structure of all rings with condition C (n). A ring satisfying C(l) has exactly one nonzero *-symmetric idempotent, the one of that ring. Hence each *-symmetric element is either nilpotent or invertible. Osborn [4] catalogued these rings and showed that a semiprimitive ring has C(1) iff R is one of (i) a division ring, (ii) a direct sum of two anti-isomorphic division rings with involution interchanging the summands, (iii) the 2 x 2 matrices over a field with the involution fixing only the scalar matrices. First we reduce to the case where R is semiprimitive. Then we collect some of the facts to be used for our main result (Theorem 4). Since the results of Lemma 1 and Lemma 2 are well known, their proofs are omitted. LEMMA 1. If each *-symmetric element s of R is either nilpotent or some (right) multiple of s is a nonzero *-symmetric idempotent, then the Jacobson radical of R, J(R), is a *-invariant ideal in which every *-symmetric element is nilpotent. LEMMA 2. If each *-symmetric element s of R is either nilpotent or some (right) multiple of s is a nonzero *-symmetric idempotent, and uE R/J(R) is a symmetric element under the induced involution *', then uis either nilpotent or some (right) multiple of uis a nonzero *'-symmetric idempotent. REMARK 1. Suppose R is a ring and for some a E R, a2 _ a is nilpotent. Then either a is nilpotent or for some polynomial q(x) with integer Received by the editors May 11, 1977 and, in revised form, July 20, 1977. AMS (MOS) subject classifications (1970). Primary 16A28. ? American Mathematical Society 1978
The Second Creation: Makers of the Revolution in 20th‐Century Physics

Probably the most remarkable aspect of 20th century physics is that it has made possible the rational investigation of the ultimate structure of matter and the origin of the universe. When a number of prominent physicists before the turn of the century thought that fundamental physics was essentially over, their conception of the scope of the field hardly included the structure of ordinary matter, much less the exotic forms dealt with routinely today. The often halting progress through this century in understanding the nature of matter was punctuated by three periods of synthesis. The first of these produced the quantum mechanical theory of atomic structure, the second successfully merged this theory with special relativity to form quantum electrodynamics, and the third resulted in the “standard” gage quantum field theory of elementary particles.
Delayed Effects of Whole Brain Radiotherapy in Germ Cell Tumor Patients With Central Nervous System Metastases

Purpose Central nervous system (CNS) metastases are uncommon in patients with germ cell tumors, with an incidence of 2–3%. CNS metastases have been managed with whole brain radiotherapy (WBRT) and concomitant cisplatin-based combination chemotherapy. Our previous study did not observe serious CNS toxicity (Int J Radiat Oncol Biol Phys 1991;22:17–22). We now report on 5 patients who developed delayed significant CNS toxicity. Patients and Methods We observed 5 patients with delayed CNS toxicity. The initial diagnosis was between 1981 and 2003. All patients had poor-risk disease according to the International Germ Cell Consensus Collaborative Group criteria. Of the 5 patients, 3 had CNS metastases at diagnosis and 2 developed relapses with CNS metastases. These 5 patients underwent WBRT to 4,000–5,000 cGy in 18–28 fractions concurrently with cisplatin-based chemotherapy. Results All 5 patients developed delayed symptoms consistent with progressive multifocal leukoencephalopathy. The symptoms included seizures, hemiparesis, cranial neuropathy, headaches, blindness, dementia, and ataxia. The median time from WBRT to CNS symptoms was 72 months (range, 9–228). Head imaging revealed multiple abnormalities consistent with gliosis and diffuse cerebral atrophy. Of the 5 patients, 3 had progressive and 2 stable symptoms. Treatment with surgery and/or steroids had modest benefit. The progressive multifocal leukoencephalopathy resulted in significant debility in all 5 patients, resulting in death (3 patients), loss of work, steroid-induced morbidity, and recurrent hospitalizations. Conclusion Whole brain radiotherapy is not innocuous in young patients with germ cell tumors and can cause late CNS toxicity.
Cellular aspects of Burkholderia cepacia infection

The Gram-negative bacterium Burkholderia cepacia has recently emerged as an important opportunistic pathogen in humans. This review focuses on the cellular aspects of B. cepacia infection and the dynamics of the B. cepacia-host cell interaction, including recent advances in our understanding of the ability of B. cepacia to adhere to, enter, and survive intracellularly within human cells.
The Velopharyngeally Inadequate Child: Phonologic Change with Intervention

Abstract Diagnostic therapy is often recommended for children before physical management of the velopharyngeal structures. There is, however, limited information about the effectiveness of such intervention programs. This study describes the changes that occurred in a 3-year-old child's production of speech during a period of diagnostic therapy, and the changes that occurred following the fitting of a prosthesis. The mother served as the primary intervener, guided by a speech-language pathologist. The mother wss able to change the child's speech so that more of her productions were at a correct place of articulation. After structural management, nasal and glottalized productions disappeared from the child's speech, but glottal stops did not.
Stress evolution following the 1811–1812 large earthquakes in the New Madrid Seismic Zone

[1] Following a series of large (Mw = 7.0–7.5) earthquakes in the New Madrid Seismic Zone (NMSZ) in the central US during 1811 and 1812, more than a dozen moderate-size (M > 5) earthquakes occurred in this region, but mostly outside of the NMSZ fault zone. We have simulated the evolution of Coulomb stress and strain energy in the NMSZ and surrounding regions following the large 1811–1812 events in a three-dimensional viscoelastic finite element model. The results show that much of the stress and strain energy released by the large 1811–1812 events has migrated to southern Illinois and eastern Arkansas, consistent with the seismicity distribution. This inherited strain energy in these areas is capable of producing damaging (M = 6–7) earthquakes today.
Lability of single-stranded deoxyribonucleic acid to hydrodynamic shear

Denatured bacteriophage DNA in alkaline solutions, or native DNA in neutral solutions were stirred at various speeds to compare their sensitivity to shear. DNA from phages T2, λ b + and λ b 2 b 5 is more sensitive to shear in the denatured than in the native state. The sensitivity to shear of T2 DNA is so great that great care must be taken in handling the solutions. A former estimate of the percentage of strands in T2 DNA with pre-existing single-strand breaks has been revised downward to 30%.
Atomic size effects in pressure-induced amorphization of a binary covalent lattice.

Applying a bond-order potential model to describe a binary covalent solid (SiC) in a molecular dynamics simulation, we show that under hydrostatic compression the homogeneous lattice undergoes an amorphous transition triggered by an elastic shear instability, with the critical pressure agreeing well with that determined from finite-load stability criteria. By modifying the potential model to suppress either atomic size difference or mixed bond preference, we demonstrate that the former effect can be dominant in favoring amorphization over polymorphic transition.
Norepinephrine Controls Both Torpor Initiation and Emergence via Distinct Mechanisms in the Mouse

Some mammals, including laboratory mice, enter torpor in response to food deprivation, and leptin can attenuate these bouts of torpor. We previously showed that dopamine beta-hydroxylase knockout (Dbh -/-) mice, which lack norepinephrine (NE), do not reduce circulating leptin upon fasting nor do they enter torpor. To test whether the onset of torpor in mice during a fast requires a NE-mediated reduction in circulating leptin, double mutant mice deficient in both leptin (ob/ob) and DBH (DBL MUT) were generated. Upon fasting, control and ob/ob mice entered torpor as assessed by telemetric core T(b) acquisition. While fasting failed to induce torpor in Dbh -/- mice, leptin deficiency bypassed the requirement for NE, as DBL MUT mice readily entered torpor upon fasting. These data indicate that sympathetic activation of white fat and suppression of leptin is required for the onset of torpor in the mouse. Emergence from torpor was severely retarded in DBL MUT mice, revealing a novel, leptin-independent role for NE in torpor recovery. This phenotype was mimicked by administration of a beta(3) adrenergic receptor antagonist to control mice during a torpor bout. Hence, NE signaling via beta(3) adrenergic receptors presumably in brown fat is the first neurotransmitter-receptor system identified that is required for normal recovery from torpor.
Structure-based discovery of a pore-binding ligand: towards assembly inhibitors for cholera and related AB5 toxins.

Cholera toxin (CT) and Escherichia coli heat-labile enterotoxin (LT) are two closely related multi-subunit AB5 proteins responsible for significant morbidity and mortality worldwide. An attractive strategy to prevent disease by these organisms is to interfere with the assembly process of these toxins, since prevention of toxin formation is better than preventing the effects of a toxin which is already formed. The B subunits form a ring with a central pore which surrounds the C-terminal residues of the A subunit. Low molecular mass compounds which would bind in the pore are likely to inhibit proper assembly of the AB5 toxins. In a pharmacophore search based on two side-chains of the A subunit, 3-methylthio-1,4-diphenyl-1H-1, 3,4-triazolium (MDT) was identified as a candidate ligand which might "plug" the pore. A 2.0 A co-crystal structure revealed that a triplet of MDTs indeed bound to the targeted region in two independent LT B pentamers in a remarkably similar manner. Clearly, MDT is a lead for developing assembly antagonists of CT and LT.
The Role of Cationic Polypeptides in Modulating HIV-1 Infection of the Cervicovaginal Mucosa

The mucosa and overlying fluid of the female reproductive tract (FRT) are portals for the heterosexual transmission of HIV-1. Toward the ongoing development of topically applied microbicides and mucosal vaccines against HIV-1, it is evermore important to understand how the dynamic FRT mucosa is involved in controlling transmission and infection of HIV-1. Cationic peptides and proteins are the principal innate immune effector molecules of mucosal surfaces, and interact in a combinatorial fashion to modulate HIV-1 infection of the cervix and vagina. While cationic peptides and proteins have historically been categorized as antimicrobial or have other host-benefitting roles, an increasing number of these molecules have been found to augment HIV-1 infection and potentially antagonize host defense. Complex environmental factors such as hormonal fluctuations and/or bacterial and viral co-infections provide additional challenges to both experimentation and interpretation of results. In the context of heterosexual transmission of HIV-1, this review explores how various cationic peptides and proteins participate in modulating host defense against HIV-1 of the cervicovaginal mucosa.
Natural hazards: Triggered mud eruption?

The Indonesian government ruled that the Lusi mud eruption was triggered by drilling and held an oil company responsible. Instead, a curved rock layer capping the mud reservoir may have amplified passing seismic waves and the trigger may have been natural.
A new method for estimating hand internal loads from external force measurements

This study examines using force vectors measured using a directional strain gauge grip dynamometer for estimating finger flexor tendon tension. Fifty-three right-handed participants (25 males and 28 females) grasped varying-sized instrumented cylinders (2.54, 3.81, 5.08, 6.35 and 7.62 cm diameter) using a maximal voluntary power grip. The grip force vector magnitude and direction, referenced to the third metacarpal, was resolved by taking two orthogonal grip force measurements. A simple biomechanical model incorporating the flexor tendons was used to estimate long finger tendon tension during power grip. The flexor digitorum superficialis and the flexor digitorum profundus were assumed to create a moment about the metacarpal phalange (MCP) joint that equals and counteracts a moment around the MCP joint measured externally by the dynamometer. The model revealed that tendon tension increased by 130% from the smallest size handle to the largest, even though grip force magnitude decreased 36% for the same handles. The study demonstrates that grip force vectors may be useful for estimating internal hand forces.
Oxygen consumption of Amphiuma means during forced activity and recovery

Abstract 1. 1. The rate of oxygen consumption of Amphiuma means , increased 3.5 fold during 30 min of forced activity, in a bi-phasic environment. There was no significant increase in cutaneous oxygen uptake, from the water, during activity or recovery after activity, whereas pulmonary oxygen uptake increased about 3.5 fold. A similar increase in oxygen uptake was observed for Amphiuma during forced activity in an aerial environment. 2. 2. Oxygen consumption wss greatest during activity and declined to within pre-exercise levels by 1 hr at most after cessation of activity (bi-phasic environment) and by 30 min in the aerial environment. 3. 3. The aerobic contribution to activity metabolism is estimated to be greater than 33% for Amphiuma . 4. 4. These data for oxygen consumption during activity and recovery, and the aerobic contribution to activity metabolism, are in marked contrast to previous studies of Amphiuma during and after activity. 5. 5. The aerobic metabolic rate of salamanders during forced activity is less than that of anuran amphibians of comparable mass, both in absolute units (ml O 2 g −1 hr −1 ) and factorial units (. VO 2, activity /. VO 2, rest ).
Existence and stability of stationary profiles of the lw scheme

In this paper we study the behavior of difference schemes approximating solutions with shocks of scalar conservation laws When a difference scheme introduces artificial numerical diffusion, for example the Lax-Friedrichs scheme, we experience smearing of the shocks, whereas when a scheme introduces numerical dispersion, for example the Lax-Wendroff scheme, we experience oscillations which decay exponentially fast on both sides of the shock. In his dissertation. Gray Jennings studied approximation by monotone schemes. These contain artificial viscosity and are first-order accurate; they are known to be contractive in the sense of any lp norm. Jennings showed existence and l1 stability of traveling discrete smeared shocks for such schemes. Here we study similar questions for the Lax-Wendroff scheme without artificial viscosity; this is a nonmonotone, second-order accurate scheme. We prove existence of a one-parameter family of stationary profiles. We also prove stability of these profiles for small perturbations in the sense of a suitably weighted l2 norm. The proof relies on studying the linearized Lax-Wendroff scheme.
Effects of input shaping on manual tracking with oscillatory controlled-element dynamics

This paper examines the manual control of mechanical systems with oscillatory dynamics, and the effects of adding input shaping to suppress command-induced vibration. Behavior of the system is analyzed using concepts from manual control theory. A series of operator experiments tested tracking behavior using elements with a low-frequency (1.25 rad/s) and a high-frequency (5 rad/s) oscillatory mode. After each experimental trial, measures of subjective task difficulty and tracking performance were recorded, and frequency-domain control characteristics were computed. Results showed that the higher-frequency oscillatory mode did not significantly decrease tracking performance from the non-oscillatory case, so input shaping did not cause a significant improvement in tracking performance. However, input shaping did cause a decrease in average subjective task difficulty, and made the system closely resemble McRuer's “crossover model.” For the lower-frequency case, the addition of input shaping significantly improved the tracking performance and reduced the tracking difficulty. These results demonstrate that input shaping can greatly improve the continuous tracking ability of a human-machine system in the presence of oscillatory modes.
Signaling pathway adaptations and novel protein kinase A substrates related to behavioral sensitization to cocaine.

Behavioral sensitization is an animal model for aspects of cocaine addiction. Cocaine-sensitized rats exhibit increased AMPA receptor (AMPAR) surface expression in the nucleus accumbens (NAc) which may in turn enhance drug seeking. To identify signaling pathways contributing to AMPAR up-regulation, we measured AMPAR surface expression and signaling pathway activation in the NAc of cocaine-sensitized rats, cocaine-exposed rats that failed to sensitize and saline controls on withdrawal days (WD) 1, 7, and 21. We focused on calcium/calmodulin-dependent protein kinase II (CaMKII), extracellular signal-regulated protein kinase (ERK), and protein kinase A (PKA). In sensitized rats, AMPAR surface expression was elevated on WD7 and WD21 but not WD1. ERK2 activation followed a parallel time-course, suggesting a role in AMPAR up-regulation. Both sensitized and non-sensitized rats exhibited CaMKII activation on WD7, suggesting that CaMKII activation is not sufficient for AMPAR up-regulation. PKA phosphorylation, measured using an antibody recognizing phosphorylated PKA substrates, increased gradually over withdrawal in sensitized rats, from below control levels on WD1 to significantly greater than controls on WD21. Using proteomics, novel sensitization-related PKA substrates were identified, including two structural proteins (CRMP-2 and α-tubulin) that we speculate may link PKA signaling to previously reported dendritic remodeling in NAc neurons of cocaine-sensitized rats.
Elevation of rhesus monkey plasma luteinizing hormone levels in response to E series prostaglandins

Abstract Experiments were carried out to assess the influence of prostaglandins (viz. PGE 1 , PGE 2 and PGF 2α ) on plasma concentrations of FSH and LH in the female rhesus monkey. Monkeys were ovariectomized and treated with estradiol benzoate to suppress endogenous gonadotropin levels prior to these experiments. Femoral venous blood was taken at intervals following a single carotid arterial injection of the PG in anesthetized monkeys. FSH and LH concentrations, determined by radioimmunoassay, were not significantly altered in 4 control animals receiving saline (2) or ethanol-saline (2), the vehicles for PGF 2α and for the E series PGs, respectively. PGE 1 (5mg) effected dramatic elevations of LH within 5 min in 3 animals and the high plasma concentrations were maintained at least for 60 min. Similarly, 5.0 mg of PGE 2 effected rapid elevation of LH concentrations, from 2- to 7-fold pre-injection levels in 3 animals. In contrast, FSH levels were not so markedly altered by PGE 1 and PGE 2 , but in general, appeared to be somewhat decreased by these treatments. PGF 2α had no effect on plasma FSH and LH concentrations. These data demonstrate the ability of PGs of the E series to elevate plasma LH concentrations in the rhesus monkey and support studies in other species suggesting a modulating role for PGs on gonadotropin secretion or release.
The possibility of informationally efficient markets

Abstract A rational expectations equilibrium with positive demand for financial information does exist under fully revealing asset price—contrary to a wide-held conjecture. Whereas a continuum of investors is inconsistent with fully revealing equilibrium, finitely many investors with average portfolios demand information in equilibrium if they can adjust portfolio size in an additive signal-return model. More information diminishes the expected excess return of a risky asset so that investors who only have a choice of portfolio composition or whose asset endowments strongly differ from the average portfolio are worse off. Under fully revealing price, information market equilibria both with and without information acquisition are Pareto efficient.
The lumbar supraspinous ligament demonstrates increased material stiffness and strength on its ventral aspect

The present work represents the first reported quantified anisotropic, inhomogeneous material constitutive data for the human supraspinous ligament (SSL). Multi-axial material data from 30 human cadaveric SSL samples was collected from distinct locations (dorsal, midsection, and ventral). A structurally motivated strain-energy based continuum model was employed to characterize anisotropic constitutive parameters for each sample. The anisotropic constitutive response correlated well with the reported experimental data (R2>0.97). Results show that in the lumbar spine both the material stiffness and stress at failure were significantly higher in the ventral region of the SSL as compared with the dorsal region (p<0.05). In the along fiber direction a higher stiffness and stress at failure were observed when compared to the transverse direction. These results indicate that modeling spinal ligaments using the hyperelastic line elements that have typically been used may be insufficient to capture their complex material response.
Using Values in Operations Research

Values pervade the field of operations research. Expressed as objectives, goals, criteria, performance measures, and/or objective functions, they are necessary in theoretical operations research models and in applications. Because of their critical role, it is useful to develop these expressions of values from basic principles. This paper outlines how to identify values for a specific decision problem, how to structure these values to facilitate thinking and analysis, and how to quantify values. Since values provide the basis for interest in a problem, these same values should guide all of our effort on that problem. Two important uses of values are to create better alternatives for decision problems and to define decision problems that are more appealing than those that confront us. On another level, the operations researcher's values are crucial in selecting the research and applications that he or she pursues. I illustrate this with a brief summary of a few projects concerning both life-threatening risks and the storage of nuclear waste. The presentation concludes with a challenge to operations researchers to consider devoting some effort and talent to what I think of as the mega-risks facing our country.
El auge económico latinoamericano

Este ensayo argumenta que el auge latinoamericano reciente tiene su origen en la coincidencia de una bonanza de precios de materias primas (mas de productos mineros que agricolas) con condiciones de financiamiento externo excepcionales. Se ha reflejado en una reduccion del endeudamiento externo y una acumulacion de reservas internacionales, pero no en austeridad fiscal, y ha reforzado la especializacion tradicional de la region en exportaciones basadas en recursos naturales. Junto con el menor crecimiento de la oferta laboral, ha facilitado el aumento de la tasa de ocupacion y la difusion de los beneficios del auge a un conjunto mas amplio de la poblacion, pero no ha logrado revertir el deterioro acumulado en la calidad de los puestos de trabajo.
Clinical Acumen: Brief Report: Therapeutic Manipulations in Severe Nocturnal Asthma. A Nonconventional Approach in a Severe High-Risk Asthmatic

A patient with severe nocturnal asthma of multifactorial pathogenesis with high-risk features leading to several episodes of nocturnal respiratory arrests is described. Despite aggressive conventional therapy with broncho-dilators and glucocorticoid agents, the patient had progressive worsening within the year prior to admission. After a nonconventional approach consisting of: high-dose inhaled steroids, afternoon dose of prednisone, addition of troleandomycin therapy, high-dose inhaled ipratropium at bedtime, maximizing serum theophylline concentrations in the early morning, and nasal CPAP through the night; the patient's pulmonary functions were optimized with minimal or no reduction in morning FEV1, and decreased airways hyperresponsiveness to methacholine.
Coupled steam and oxidative reforming for hydrogen production in a novel membrane circulating fluidized-bed reformer

A novel circulating fluidized-bed membrane reactor employing a reactor-regenerator type of configuration is proposed for hydrogen production by the steam reforming of natural gas. The removal of hydrogen through hydrogen-permeable membranes pushes the equilibrium toward higher production of hydrogen. In the present paper, modeling studies are carried out on the reactor section of this configuration. Cases with and without hydrogen-selective membranes (cocurrent and countercurrent) are considered and compared. The model results show the great advantages associated with the breaking of the thermodynamic limitations coupled to the hydrodynamic limitations associated with the previous generations of bubbling fluidized-bed reformers. It is shown that autothermal operation can be achieved through simultaneous oxidative reforming, giving high hydrogen yields and productivities with low net consumption of energy.
Germinal centres in the spleens of neonates and stillbirths

Abstract Sections of spleens from 235 stillbirths and 227 babies who died between the ages of 1 and 35 days were examined. None of the stillbirths showed any germinal centres, neither did the spleens of any of the babies who died between the ages of 1 and 14 days. From the age of 15 days onwards, the germinal centres started to appear in varying numbers. The appearance of germinal centres in the spleen is further delayed in infants born before 37 wk gestation. Germinal centres in the spleen in neonates do not appear to be related to the presence of inflammatory changes elsewhere in the infant.
Transverse stimulated Raman scattering in KDP

Optical components of large-aperture, high irradiance and high fluence lasers can experience significant levels of stimulated scattering along their transverse dimensions. The authors have observed transverse stimulated Raman scattering in large aperture KDP crystals, and have measured the stimulated gain coefficient. With sufficiently high gain, transverse stimulated scattering can lead to energy loss from the main beam and, more importantly, optical damage in the components in which this scattering occurs. Thus transverse stimulated,scattering is of concern in large aperture fusion lasers such as Nova and Beamlet, which is a single-aperture, full-scale scientific prototype of the laser driver for the proposed National Ignition Facility.
Patterns in Potential Impacts Associated with Contamination Events in Water Distribution Systems

Properly designing contamination warning systems requires an understanding of potential public health impacts for a range of contaminated water systems and a wide range of contaminants. To address this need, we determined potential impacts for 12 actual systems serving populations ranging from ∼ 104 to over 106 persons by simulating contamination events for the systems. We found several consistent patterns in the estimated impacts (defined as the size of the population receiving an ingestion dose above a given level). Significant impacts, those similar to worst-case impacts, result from injections of contaminants at only a minority of nodes. For contaminants with high thresholds for adverse effects, significant exposures are concentrated near the injection location, and impacts are not sensitive to population served. However, for contaminants with low thresholds, significant exposures are present over a significant fraction of the system, and impacts are sensitive to population. When exposures are concent...