cssi/SciSciGPT-SciSciNet huggingface dataset:
Nitric oxide-releasing xerogel microarrays prepared with surface-tailored poly(dimethylsiloxane) templates

Surface graft polymerization with poly(ethylene glycol) acrylate is reported as an effective method for modifying the surface of poly(dimethylsiloxane) array templates thus enabling the preparation of nitric oxide (NO)-releasing xerogel micropatterns. The surface wettability of PEGA-grafted templates was sufficient to overcome the flow resistance of ethyltrimethoxysilane (ETMOS) sol solutions and allow the formation of xerogel microarrays via capillary action of sol through the template channels. Due to the combined versatility of both sol−gel chemistry and micropatterning, substrates were modified with a range of aminosilane-doped xerogel microarrays with variable NO release properties. Several parameters were studied including (1) NO surface flux as a function of type and concentration of aminosilane NO-donor precursor; (2) micropattern dimensions for maximizing surface flux and duration of NO release; and (3) the effect of microstructure separation on localized NO surface concentration as determined wi...
Breaking Literacy Boundaries through Critical Service-Learning: Education for the Silenced and Marginalized.

Originating as counter normative pedagogies, both service‐learning and critical pedagogies hold a common commitment to subvert and transform facets of school life that may alienate and oppress students. This article explores how critical pedagogies and service‐learning might provide complementary benefits and become a more compelling emancipatory pedagogy of ‘critical service‐learning’ for K‐12 educational contexts. This work proposes that these pedagogies of civic literacy and critical literacy can break their boundaries to intersect and provide a form of education for those students most marginalized and alienated by oppressive features of traditional instruction.
Are short, low-barrier hydrogen bonds unusually strong?

In a symmetric hydrogen bond (H-bond), the hydrogen atom is perfectly centered between the two donor atoms. The energy diagram for hydrogen motion is thus a single-well potential, rather than the double-well potential of a more typical H-bond, in which the hydrogen is covalently bonded to one atom and H-bonded to the other. Examples of symmetric H-bonds are often found in crystal structures, and they exhibit the distinctive feature of unusually short length: for example, the O−O distance in symmetric OHO H-bonds is found to be less than 2.5 A. In comparison, the O−O distance in a typical asymmetric H-bond, such as ROH···OR2, ranges from about 2.7 to 3.0 A. In this Account, we briefly review and update our use of the method of isotopic perturbation to search for a symmetric, centered, or single-well-potential H-bond in solution. Such low-barrier H-bonds are thought to be unusually strong, owing perhaps to the resonance stabilization of two identical resonance forms [A−H···B ↔ A···H−B]. This presumptive bon...
Isolation and identification of a wheat flour compound causing sticky dough

ABSTRACT Fractionation and reconstitution studies of a flour from 1B/1R wheat showed that the factor causing sticky dough was water soluble. In addition, these studies showed that enzymes and lipids in the flour were not responsible for producing sticky dough. Dialysis experiments showed that the active component was nondialyzable. Gel-filtration chromatography of the retentate fraction showed that the substance causing sticky dough contained both a carbohydrate and a UV-absorbing material. Treatment of the active fraction with base caused the fraction to lose its ability to cause stickiness. The UV-absorbing material and the carbohydrate fraction had to be covalently linked for the compound to be active. Gas chromatography-mass spectrometry and HPLC analysis showed that the UV-absorbing moiety was predominantly trans-ferulic acid, and the carbohydrate part was a glucose polymer. The glucose polymer was not degraded by α-amylase but was degraded by lichenase, suggesting that the glucose polymer was a mixe...
Emergency Department Thoracotomy: Survival of the Least Expected

Although emergency department thoracotomy (EDT) is often considered a controversial “last chance” method of resuscitation, we hypothesized that EDT performed in a busy urban Level I trauma center has significant salvage rates despite the absence of traditional survival predictors. A retrospective review revealed that 180 patients underwent EDT after traumatic arrest for penetrating injury between 2000 and 2005. All were deemed nonsalvageable by other resuscitation methods. Injury mechanism and location, signs of life (SOLs), initial cardiac rhythm, and presence of vital signs were analyzed. In total, 23 patients survived hospitalization neurologically intact. Compared to nonsurvivors, survivors more often suffered multiple stab wounds (21.7% vs. 1.9%, p = 0.001), presented with field (95.7% vs. 72.6%, p = 0.016) and ED (87.0% vs. 60.5%, p = 0.014) SOLs, had sustainable cardiac rhythms (sinus tachycardia, 43.5% vs. 10.2%, p = 0.001; normal sinus rhythm, 17.4% vs. 4.5%, p = 0.037), and had measurable vital signs (65.2% vs. 25.5%; p = 0.001). However, only 3 of 23 (13.0%) survivors had all survival predictors, and one survivor had none. Frequent predictors in survivors were field SOLs (95.7%), ED SOLs (87.0%), salvageable initial cardiac rhythms (78.3%), and obtainable vital signs (65.2%). Stabbing mechanism (30.4%) and cardiac injury location (30.4%) were least common. Had a strict policy of EDT performance based solely on the presence of survival predictors been followed and EDT withheld, several patients who ultimately survived would have died. Our study suggests that EDT is a technique that should be utilized for patients with critical penetrating injuries even in the absence of many traditional survival predictors.
Training needs of pediatric occupational therapists in assistive technology

The training of providers working with children who need assistive technology devices or services has not kept pace with the explosion of new, more sophisticated assistive technology devices now available. This article reports on a national survey of 272 pediatric occupational therapists, who responded to questions about their training needs in the area of assistive technology and delivering assistive technology services. A sizable percentage of these therapists reported less-than-adequate training in policies governing assistive technology services and the organization and function of the service system. The therapists would like training that is accessible and affordable in the areas of funding of technology and services; collaborating with families and other service providers; and accessing reliable, knowledgeable vendors. These findings underscore the need to develop pre-service and in-service training in assistive technology for providers who work with children who have disabilities.
Nucleophilic addition to the η6-iridathiabenzene ligand in [η6-Cp*Ir(C,S-2,5-Me2T)]FeCp+

Abstract The η6-iridathiabenzene ring coordinated to CpFe+ in [η6-Cp*Ir(C,S-2,5-Me2T)]FeCp+ (2) undergoes attack by nucleophiles. Phosphorus-donors, C N–Bun, and CN− add to the Ir to give products with an η5-coordinated iridathiabenzene ligand. Hydride (Et3BH−, HFe ( CO ) 4 - ) and Ph− nucleophiles attack at the sulfur to give products with Ir–SH and Ir–SPh groups and an iridacyclopentadiene unit. Other reactions of 2 are described together with structure determinations of key compounds.
Integrated organic and nitrogen removal with electricity generation in a tubular dual-cathode microbial fuel cell

Abstract This study presented a dual-cathode microbial fuel cell (MFC) that was designed to accomplish nitrification in its outer cathode and denitrification in the inner cathode. The MFC was continuously operated for more than 150 days and achieved organic removal of 85–99% in the anode, depending on the initial organic loading rates. More than 96% of the ammonium was removed, while the total nitrogen removal was between 66.7 and 89.6%, largely affected by the remaining nitrate in the effluent of the inner cathode. The coulombic efficiency suggested that the nitrate was primarily removed by bioelectrochemcial denitrification in the inner cathode, especially at the low nitrogen loading rates. However, a higher nitrogen loading rate encouraged nitrate migration through the anion exchange membrane, thereby being removed by conventional denitrification. The preliminary energy analysis suggested that the energy production in the dual-cathode MFC could potentially support its pumping system. To achieve an energy-neutral system, aeration must be omitted in the future design and passive oxygen supply should be considered with a proper design of the outer cathode. Those results demonstrated the feasibility of using a tubular dual-cathode MFC to remove both organics and nitrogen while producing electricity.
The Contributions of School Desegregation to Housing Integration: Case Studies in Two Large Urban Areas:

This article examines a half century of housing and school segregation data in two large California school districts. Based on a review of both the methods and the substantive data available tracking the relationship between school and housing integration, the study reported here shows that very substantial school-level integration in these two districts was followed by equally substantial housing desegregation. The study relies on Theil’s H as the most appropriate measure of social segregation because this measure can be used to study the integration of multiple groups and can be decomposed to document where the most severe isolation of particular subgroups is occurring.
Cover Picture: Fabrication of Stable Low‐Density Silica Aerogels Containing Luminescent ZnS Capped CdSe Quantum Dots (Adv. Mater. 15/2006)

Luminescent CdSe quantum dots 2.5 and 6.0 nm in diameter can be incorporated into low-density silica aerogel matrices. In work reported by Stiegmann and co-workers on p. 1965, aerogels are formed from the supercritical CO2 extraction of an alcogel containing quantum dots surface passivated with 3-aminopropyltriethoxysilane. The resulting aerogels, shown on the cover, are low scattering and display intense, stable luminescence.
The Oddono's sulcus and its relation to the renal junctional parenchymal defect and the interrenicular septum

The anatomy responsible for the sonographic diagnosis of the renal “junctional parenchymal defect” and “interrenicular septum” is caused by perirenal fat along a line of incomplete fusion of two primary renal lobes. Studies using CT, MRI and cadaver observations are presented. “Oddono's sulcus” is suggested as a name for the changes in honor of the author who first described these anatomic findings.
Characterization of the tryptophan tryptophyl-semiquinone catalytic intermediate of methylamine dehydrogenase by electron spin-echo envelope modulation spectroscopy

The electronic structure of the tryptophan tryptophyl-semiquinone (TTQ•) cofactor generated by addition of the substrate, methylamine, to methylamine dehydrogenase (MADH) from Paracoccus denitrificans has been studied by continuous-wave electron paramagnetic resonance (cw-EPR) and electron spin−echo envelope modulation (ESEEM) spectroscopy. The cw-EPR spectrum of TTQ semiquinone prepared by substrate addition (N-form) was found to differ substantially from that observed when the semiquinone was generated by dithionite reduction of the enzyme (O-form). These differences prompted a detailed study of hyperfine and nuclear quadrupole interactions of the three 14N atoms of the semiquinone species using ESEEM. Two of these heteroatoms are derived from the indole and indole−quinone side chains that comprise TTQ, while the third 14N originates from substrate methylamine. Three-pulse ESEEM spectra of the CH314NH2-reduced sample showed three isolated features at 1.0, 1.5, and 4.3 MHz, which were absent in the MADH ...
Knowledge Structures and Linear Separability: Integrating Information in Object and Social Categorization

These experiments were designed to determine if the naturalness of abstract category structures varies with content domain. Specifically, the degree to which linear separability constrains categorization was investigated in object and social domains. Linearly separable (LS) categories are categories that can be perfectly partitioned on the basis of a weighted, additive combination of component information. Across a wide variety of stimulus materials and classification tasks LS structures were found to be more compatible with social than object materials. In sorting tasks, participants were more likely to sum characteristic features and form LS categories with social materials. In learning tasks, LS structures were easier to learn with social materials but nonlinearly separable structures were easier to learn with object materials. This interaction between category structure and content domain was attributed to differences in the types of knowledge and integration strategies that were activated. In object conditions, strategies that were inconsistent with adding independent features were observed (e.g., focusing on single dimensions, using configural properties, and relying on analogy). In social conditions, however, summing the evidence and learning LS structures appeared to be a natural strategy. It was concluded that the structure of knowledge varies with domain, and consequently it will be difficult to formulate domain general constraints in terms of abstract structural properties such as linear separability. Differences between object and social categorization systems are discussed.
An RNA tertiary structure of the hepatitis delta agent contains UV-sensitive bases U-712 and U-865 and can form in a bimolecular complex

Genomic RNA of the hepatitis delta agent has a highly conserved element of local tertiary structure. This element contains two nucleotides which become covalently crosslinked to each other upon irradiation with UV light. Using direct RNA analysis, we now identify the two nucleotides as U-712 and U-865 and show that the UV-induced crosslink can be broken by re-exposure to a 254 nm peak UV light source. In the rod-like secondary structural model of delta RNA, nucleotides U-712 and U-865 are off-set from each other by 5-6 bases, a distance too great to permit crosslinking. This model needs to be modified. Our data indicate that bases U-712 and U-865 closely approximate each other and suggest that the smooth helical contour proposed for delta RNA is interrupted by the UV-sensitive element. The nucleotide sequence shows that the UV-sensitive site does not have a particularly high density of conventional Watson-Crick base pairs compared to the rest of the genome. However, this element may have a number of non-Watson-Crick bonds which confer stability. Following UV-crosslinking and digestion with 1 mg/ml of RNase T1 at 37 degrees C for 45 min in 10 mM Tris-HCl, 1 mM EDTA (conditions expected to give complete digestion), this element can be isolated as part of a 54 nucleotide long partial digestion product containing at least 16 internal G residues. UV-crosslinking analysis shows that this unusual tertiary structural element can form in a bimolecular complex.
Organometallic enantiomeric scaffolding: organometallic chirons. Total synthesis of (-)-Bao Gong Teng A by a molybdenum-mediated [5 + 2] cycloaddition.

Bao Gong Teng A, an optically active tropane alkaloid with hypotensive and miotic activity isolated from the Chinese herb Erycibe obtusifolia Benth, was synthesized by an “organometallic chiron” strategy in which single enantiomers of TpMo(CO)2(η3-pyridinyl) complexes are produced in quantity and then elaborated easily and efficiently to generate, after demetalation, highly enantiopure advanced synthetic intermediates possessing the tropane core.
Domain wall mobility in rare earth-transition metal alloys

The domain-wall mobility of amorphous alloys of rare-earth-transition-metal thin films has been measured at high temperatures (50 to 200 degrees C) by means of the dynamic bubble collapse method for TbCo, GdCo, GdTbCo, TbFeCo, GdTbFe, and GdTbFeCo. It is found that the domain-wall velocity is linearly proportional to the applied field if the field is significantly larger than the coercivity. The values of the mobilities range from 0.9 to 29 cm/s-Oe. The mobility increases slightly with temperature in the range of 50-200 degrees C. These data are in agreement with the fact that mobility is linearly related to the domain-wall width, which in turn increases in this temperature range because of the rapidly decreasing anisotropy. It is also found that mobility depends on the composition. Increasing the ratio of Gd to Tb significantly raises the value of the mobility. >
Cinephotomicrographic observations on intracellular bubble formation in Tetrahymena

A miniature cuvette pressure chamber for microscopy and highspeed (400 frames per second) cinephotographic recordings was developed to study intracellular bubble formation in Tetrahymena. The investigations show, for the first time, that intracellular bubble formation can occur, but only when the nitrogen gas supersaturations are higher than 150 atm. However, substantial fractions of the cell populations remain unaffected by exposures to gas supersaturations as high as 200 atm.
Putative superoxide dismutase activity of iron-EDTA: A reexamination

It has been reported that iron-EDTA complexes mimic the action of superoxide dismutase, displaying 0.01% of the activity of the enzyme (Halliwell, B., 1975, FEBS Lett., 56, 34–38). This was purportedly directly confirmed by J. G. McClune, J. A. Fee, G. A. McCluskey, and J. T. Groves, 1977, J. Amer. Chem. Soc., 99, 5220–5222. A reexamination of the behavior of this compound has demonstrated that it does not catalyze the dismutation of O2−, but rather inferferes with assays for superoxide dismutation activity, which are based on the reductions of nitroblue tetrazolium or of cytochrome c. The sources of this interference have been examined. Investigators engaged in searching for mimics of superoxide dismutase are urged to be wary of similar artifacts.
Pump-probe reflectivity study of ultrafast dynamics of strongly correlated 5f electrons in UO2

5f electrons in the Mott insulator UO2 produce intriguing electronic states and dynamics, such as strong correlation and f-f excitations. We have performed femtosecond pump-probe reflectivity measurements on a single crystal UO2 at temperatures of 5-300 K to study the ultrafast dynamics of photoexcited 5f electrons. Laser pulses at 400 nm pump 5f electrons across the Mott gap, while those at 800 nm probe the pump-induced change of reflectivity. We find temperature-dependent excitation and relaxation processes and long-lived acoustic phonons, and extract picosecond risetimes and microsecond relaxation times at low temperatures. The observed slow relaxation is ascribed to the decay of Hubbard excitons formed by U3+-U5+ pairs.
RFID tag antenna based temperature sensing

Temperature monitoring is important in a number of fields, particularly cold supply chain applications. Most commercial wireless temperature sensors consist of transceivers, memory and batteries to maintain a temperature time history but this is expensive and allows for limited sensor deployment. In this paper, we propose a low cost temperature sensor based on the paradigm of passive RFID tag antenna based sensing. A simple mechanical method to permanently induce changes in RFID tag power characteristics upon exposure to temperatures greater than a threshold is presented. Critical temperature threshold violations can then be detected by monitoring received backscatter signal strength at a reader. The feasibility of the proposed hypothesis is examined via theoretical and experimental means. It will be shown that this sensing paradigm has the potential to greatly increase the pervasiveness of temperature sensing nodes and improve supply chain visibility and performance.
Intracellular Neural Recording with Pure Carbon Nanotube Probes

The computational complexity of the brain depends in part on a neuron’s capacity to integrate electrochemical information from vast numbers of synaptic inputs. The measurements of synaptic activity that are crucial for mechanistic understanding of brain function are also challenging, because they require intracellular recording methods to detect and resolve millivolt- scale synaptic potentials. Although glass electrodes are widely used for intracellular recordings, novel electrodes with superior mechanical and electrical properties are desirable, because they could extend intracellular recording methods to challenging environments, including long term recordings in freely behaving animals. Carbon nanotubes (CNTs) can theoretically deliver this advance, but the difficulty of assembling CNTs has limited their application to a coating layer or assembly on a planar substrate, resulting in electrodes that are more suitable for in vivo extracellular recording or extracellular recording from isolated cells. Here we show that a novel, yet remarkably simple, millimeter-long electrode with a sub-micron tip, fabricated from self-entangled pure CNTs can be used to obtain intracellular and extracellular recordings from vertebrate neurons in vitro and in vivo. This fabrication technology provides a new method for assembling intracellular electrodes from CNTs, affording a promising opportunity to harness nanotechnology for neuroscience applications.
Body Art: Prevalence, Search and Evaluation Among University Business Students

ABSTRACT Although adorning the body by means of tattoos and body piercings is an ancient practice, it has become increasing popular as of late in Western cultures including the United States (U.S.A.). The increasing popularity of body art has been most apparent among young adults and has given rise to a growth industry catering to these consumers. Little attention has been paid to the increasing popularity of body art from the marketing perspective. The purposes of this study were to explore the prevalence of body art among college students and to gain an appreciation of the nature of the consumer decision-making process with respect to body art. Data were collected by means of a survey from 496 respondents at 14 geographically diverse colleges and universities in the U.S.A. The results include overall prevalence rates for tattoos and body piercings as well as relationships between prevalence of both forms of body art and key demographic variables including gender. Also included are results concerning the...
Optically programming DNA computing in microflow reactors.

Abstract The programmability and the integration of biochemical processing protocols are addressed for DNA computing using photochemical and microsystem techniques. A magnetically switchable selective transfer module (STM) is presented which implements the basic sequence-specific DNA filtering operation under constant flow. Secondly, a single steady flow system of STMs is presented which solves an arbitrary instance of the maximal clique problem of given maximum size N. Values of N up to about 100 should be achievable with current lithographic techniques. The specific problem is encoded in an initial labeling pattern of each module with one of 2N DNA oligonucleotides, identical for all instances of maximal clique. Thirdly, a method for optically programming the DNA labeling process via photochemical lithography is proposed, allowing different problem instances to be specified. No hydrodynamic switching of flows is required during operation — the STMs are synchronously clocked by an external magnet. An experimental implementation of this architecture is under construction and will be reported elsewhere.
Tunneling conductivity of one- and two-component alkanethiol bilayers in Hg–Hg junctions

Abstract Electron tunneling (ET) through alkanethiol bilayers trapped between two small mercury drops (Hg–Hg tunneling junction, geometric area: 8×10−4 cm2) was investigated. Self-assembled monolayers were formed on Hg drops using one- or two-component solutions of n-alkanethiols (ranging from nonanethiol to hexadecanethiol) in hexadecane. Mercury drops covered by monolayers were brought into contact using micromanipulators. Current–voltage cyclic curves were used to measure the capacitance and tunneling current for the alkanethiol bilayer. The experimental current–voltage curves were compared with the following theoretical models: classical Simmons theory, Simmons theory modified by including effective electron mass (Lindsay's model), and a model for off-resonance tunneling through a molecular bridge (Ratner's model). The classical Simmons theory does not fit our tunneling data while Lindsay's and Ratner's models agree reasonably well with the tunneling characteristics of Hg–Hg junctions. The electrical properties of two-component bilayers, containing a mixture of hexadecanethiol and nonanethiol deposited on each Hg drop, were studied as a function of a monolayer composition. The thickness of the two-component monolayer on each Hg drop depends linearly on the mole-fraction of nonanethiol. ET through a two-component system is less efficient than ET through single-component bilayers. This result is rationalized in terms of diminished electronic coupling through van der Waals contacts.
Hole structures of polymers and zeolites probed by two-dimensional angular correlation of annihilation radiation

The two-dimensional angular correlation of annihilation radiation (2D-ACAR) technique has been developed to measure the hole structure of stretched and oriented polymers. The determination of polymer hole structure is demonstrated in a stretched semi-crystalline polyaryl-ether-ether-ketone (PEEK) sample. The atomic scale anisotropy is found to be consistent with the macroscopic scale stretch ratio. Applications of the 2D-ACAR method to image the three-dimensional hole, free-volume, and cavity structures of molecular systems are discussed.
The osmotic response of the isolated tectorial membrane of the chick to isosmotic solutions: effect of Na+, K+, and Ca2+ concentration.

Changes in the size, shape, and structure of the isolated tectorial membrane of the chick were measured in response to isosmotic changes in the ionic composition of the perfusion solution. Substitution of artificial perilymph (AP) for artificial endolymph (AE) caused a small (~ 15%), slow (time constants τ ~ 12 min) shrinkage of the thickness of the tectorial membrane that was largely reversed on return to AE. Substitution of AP for AE alters not only the predominate cation (from K+ to Na t) but also the Ca2+ concentration (from < 7 μmol/1 to 2 mmol/1). Additional experiments were performed to separate effects of each of these changes. When a high-Na +, low-Ca2+ solution was substituted for a high-Kt, low-Ca2+ solution (AE), the tectorial membrane swelled significantly, often to more than twice its original thickness (the largest swelling was 337%), with a slow time course (τ ~ 23 min). Addition of Ca2+ to either high-K+ or high-Na + solutions caused rapid shrinkage of the tectorial membrane (τ ~ 2–3 min). Addition of the Ca2+ chelator EGTA caused rapid swelling (τ ~ 4 min). Large osmotic responses were only partially reversible and caused long-lasting changes. For example, long-duration solution changes that produced large, rapid osmotic responses early in an experiment tended to produce smaller and slower responses later in the experiment. In contrast, the small osmotic responses to short-duration solution changes were repcatable for tens of hours. Changes in ionic composition of the bath affected not only the thickness of the tectorial membrane but also its other dimensions. Responses were not generally isotropic; both the size and shape of the tectorial membrane generally changed. Consistent changes in microstructure accompanied the osmotic changes.
Extending visual languages for multimedia

Visual languages, which let users customize iconic sentences, can be extended to accommodate multimedia objects, letting users access media dynamically. Teleaction objects, or multimedia objects with knowledge structures, can be designed using visual languages to automatically respond to events and perform tasks like "find related books" in a virtual library.
Distinguishing N- and C-terminus ions for mass spectrometry sequencing of proteins without prior degradation

Identifying complementary pairs of fragment ions, b-type vs y-type, is a key step in mass spectral sequencing of proteins without degradation prior to ionization. Observations that b-type ions tend to be less stable than y-type have been extended to carbonic anhydrase (29 kDa) as a model protein. Infrared multiphoton dissociation (IRMPD) of 24+, 27+, 30+ molecular ions shows y-type ions from complementary pairs require, on average, 27% longer irradiation times for onset of abundance decrease, while in nozzle/skimmer dissociation of all charge states, y-type ions require a 20% higher potential difference. In some cases, b-ion dissociation appears to accompany its formation, as its rate of increase with increasing energy deposition is far less than that of its y-complement.
Optimal supply and threshold scaling for subthreshold CMOS circuits

With technology scaling, power supply and threshold voltage continue to decrease to satisfy high performance and low power requirements. In the past, subthreshold CMOS circuits have been inadequate for high performance applications, but have been used in applications that require ultra low power dissipation. Many applications including medical and wireless applications, require ultra low power dissipation with low-to-moderate performance (10kHz-100MHz). In this work, using BSIM3 models, the performance and energy dissipation of 0.18-/spl mu/m CMOS circuits for the range of V/sub dd/ = 0.1-0.6V and V/sub th/ = 0-0.6V are analyzed to show that subthreshold CMOS circuits can be used in low performance applications. A simple characterization circuit is introduced which can be used to evaluate the performance and energy dissipation for a given process under varying activity. These results are useful in circuit design by giving insight into optimal voltage supply and threshold voltage operation for a given application specification.
Divide-and-conquer quantum mechanical material simulations with exascale supercomputers

Recent developments in large-scale materials science simulations, especially under the divide-andconquer method, are reviewed. The pros and cons of the divide-and-conquer method are discussed. It is argued that the divide-and-conquer method, such as the linear-scaling three-dimensional fragment method, is an ideal approach to take advantage of the heterogeneous architectures of modern-day supercomputers despite their relatively large prefactors among linear-scaling methods. Some developments in GPU electronic structure calculations are also reviewed. The accelerators like GPU could be an essential part for the future exascale supercomputing.
Oligomeric dithienopyrrole-thienopyrroledione (DTP-TPD) donor-acceptor copolymer for organic photovoltaics

A new donor-acceptor copolymer system based upon a dithienopyrrole (DTP) donor moiety and a thienopyrrolodione (TPD) accepting moiety has been designed and synthesized for organic photovoltaic (OPV) applications. The TPD accepting moiety has recently gained significant attention in the OPV community and is being incorporated into a number of different polymer systems. In contrast, the DTP donor moiety has received only limited attention, likely due in part to synthetic difficulties relating to the monomer. In our hands, the bis(trimethyltin)-DTP monomer was indelibly contaminated with ∼5% of the mono-destannylated DTP, which limited the Stille polymerization with the dibromo-TPD monomer (>99% pure) to produce material with M n ∼ 4130 g/mol (PDI = 1.10), corresponding to around eight repeat units. Despite this limitation, UV-visible absorption spectroscopy demonstrates strong absorption for this material with a band gap of ∼1.6 eV. Cyclic voltammetry indicates a highest occupied molecular orbital (HOMO) energy level of −5.3 eV, which is much lower than calculations predicted. Initial bulk heterojunction OPV devices fabricated with the fullerene acceptor phenyl C 61 butyric acid methyl ester (PCBM) exhibit V oc ∼ 700 mV, which supports the deep HOMO value obtained from CV. These results suggest the promise of this copolymer system.
Reducing Maximum Stretch in Compact Routing

It is important in communication networks to use routes that are as short as possible (i.e have low stretch) while keeping routing tables small. Recent advances in compact routing show that a stretch of 3 can be achieved while maintaining a sub- linear (in the size of the network) space at each node [14]. It is also known that no routing scheme can achieve stretch less than 3 with sub-linear space for arbitrary networks. In contrast, simulations on real-life networks have indicated that stretch less than 3 can indeed be obtained using sub-linear sized routing tables[6]. In this paper, we further investigate the space-stretch tradeoffs for compact routing by analyzing a specific class of graphs and by presenting an efficient algorithm that (approximately) finds the optimum space-stretch tradeoff for any given network. We first study a popular model of random graphs, known as Bernoulli random graphs or Erds-Renyi graphs, and prove that stretch less than 3 can be obtained in conjunction with sub- linear routing tables. In particular, stretch 2 can be obtained using routing tables that grow roughly as n3/4 where n is the number of nodes in the network. Compact routing schemes often involve the selection of landmarks. We present a simple greedy scheme for landmark selection that takes a desired stretch s and a budget L on the number of landmarks as input, and produces a set of at most 0(L logn) landmarks that achieve stretch s. Our scheme produces routing tables that use no more than O(logn) more space than the optimum scheme for achieving stretch s with L landmarks. This may be a valuable tool for obtaining near-optimum stretch-space tradeoffs for specific graphs. We simulate this greedy scheme (and other heuristics) on multiple classes of random graphs as well as on Internet like graphs.
A Preliminary Experimental Examination of the Effect of Emotion Dysregulation and Impulsivity on Risky Behaviors Among Women With Sexual Assault–Related Posttraumatic Stress Disorder

Posttraumatic stress disorder (PTSD) is associated with a wide range of risky behaviors (e.g., substance use and risky sexual behaviors); however, few studies have examined mechanisms that may underlie risky behaviors in this population. The present study utilized a prospective experimental design to examine the effects of emotion dysregulation and impulsivity on risky behaviors across time. Thirty women with sexual assault-related PTSD were randomly assigned to receive emotion modulation (EM), impulsivity reduction (IR), or healthy living (HL; comparison condition) skills trainings. Participants completed measures of emotion dysregulation, impulsivity, and risky behaviors pre-manipulation and 1-month post-manipulation. Participants in the EM and IR conditions reported a significant reduction in risky behaviors from pre- to post-manipulation relative to the HL condition. Changes in emotion dysregulation from pre- to post-manipulation fully accounted for reductions in risky behaviors over time. RESULTS provide preliminary experimental support for the role of emotion dysregulation in risky behaviors. Language: en
Parallel Fourier Path-Integral Monte Carlo calculations of absolute free energies and chemical equilibria ✩

We present a parallel implementation of the Fourier Path Integral Monte Carlo method for calculating the absolute free energies of many-body systems. The implementation adopts the message-passing paradigm for parallelization, with the use of the Message Passing Interface (MPI) libraries. A portable computer program, written using Fortran 90, has been developed and tested on a variety of platforms such as the SGI Origin, the IBM SP, and the Cray T3D and T3E. We have used the program to demonstrate the efficacy of importance sampling in configuration space. We have also used the program to calculate the partition function, and hence the absolute free energies, of triatomic molecules and four-body systems.
Non-invasive in vivo determination of UVA efficacy of sunscreens using diffuse reflectance spectroscopy.

Background: Evaluation of sunscreen efficacy is most relevant when measured on the surface it is meant to protect, namely on human skin in vivo. Application of any material to the surface of the skin alters its optical properties. Diffuse reflectance spectroscopy (DRS) is a non-invasive technique to measure changes in the optical properties of the skin decoupled from its biological responses following sunscreen application. Methods: This study compared measurements of UVA efficacy of oxybenzone and avobenzone at different concentrations (0–5%) using DRS, human phototest and an in vitro technique. Twenty subjects were enrolled for each product measured by DRS and 10 different subjects were enrolled for each product measured by human phototest. Six areas 5 cm × 10 cm were outlined on each subject's back. DRS measurements were performed on four subsites within each area before and 20 min after sunscreen application. UVA efficacy for each concentration of product was calculated from the measured transmission spectrum of a given product convoluted with the spectrum of a Xenon light source adequately filtered to obtain the UVA spectrum from 320 to 400 nm and the erythema action spectrum. Phototesting was performed using the same light source and persistent pigment darkening as the biological endpoint. Measurements were made with sunscreen coverage of 2 mg/cm2. In vitro measurements were performed using an Optometrics instrument. Results: All three techniques showed a linear response between calculated UVA efficacy and product concentration. Conclusions: This study showed that DRS is a rapid and reproducible method to calculate UVA efficacy of sunscreen materials and that its results correlate closely with those obtained by human phototesting.
Disparate In Vitro and In Vivo Antileukemic Effects of Resveratrol, a Natural Polyphenolic Compound Found in Grapes

Resveratrol (trans-3,4,5-trihydroxystilbene), a polyphenol found in grapes and grape wine, has been reported to exhibit cardioprotective and chemopreventive activity against chemical carcinogenesis. It has also been shown to have growth inhibitory activity toward solid tumors in vivo. However, the antitumor activity of resveratrol against hematologic tumors in vivo has not been examined. In this study, the antileukemic activity of resveratrol in vitro and in vivo was examined using a mouse myeloid leukemia cell line (32Dp210). Treatment of 32Dp210 leukemia cells with resveratrol at micromolar concentrations (25-50 mol/L) significantly and irreversibly inhibited their clonal growth in vitro. The clonal growth inhibition by resveratrol was associated with extensive cell death and an increase in hypodiploid (sub-G1) cells. Resveratol caused internucleosomal DNA fragmentation, suggesting apoptosis as the mode of cell death in 32Dp210 cells. DNA fragmentation was associated with activation of caspase-3, because cleavage of procaspase-3 was detected in resveratrol-treated cells. Although 32Dp210 cells treated with resveratrol in vitro did not produce leukemia in vivo, only a weak antileukemic effect of resveratrol was observed when administered orally. At doses of 8 mg or 40 mg/kg body daily, five times/wk, resveratrol did not affect the survival of mice injected with leukemia cells. Weak potential antileukemic activity of resveratrol was suggested only at a dose of 80 mg/kg body (2 survivors of 14 mice treated). Thus, despite strong antiproliferative and proapoptotic activities of resveratrol against 32Dp210 cells in vitro, a potential antileukemia effect in vivo, if present, occurs only in a small fraction of mice. J. Nutr. 132: 2076-2081, 2002.
Context Preserving Maps of Tubular Structures

When visualizing tubular 3D structures, external representations are often used for guidance and display, and such views in 2D can often contain occlusions. Virtual dissection methods have been proposed where the entire 3D structure can be mapped to the 2D plane, though these will lose context by straightening curved sections. We present a new method of creating maps of 3D tubular structures that yield a succinct view while preserving the overall geometric structure. Given a dominant view plane for the structure, its curve skeleton is first projected to a 2D skeleton. This 2D skeleton is adjusted to account for distortions in length, modified to remove intersections, and optimized to preserve the shape of the original 3D skeleton. Based on this shaped 2D skeleton, a boundary for the map of the object is obtained based on a slicing path through the structure and the radius around the skeleton. The sliced structure is conformally mapped to a rectangle and then deformed via harmonic mapping to match the boundary placement. This flattened map preserves the general geometric context of a 3D object in a 2D display, and rendering of this flattened map can be accomplished using volumetric ray casting. We have evaluated our method on real datasets of human colon models.
Identification in Face-to-Face, Hybrid, and Pure Virtual Teams: Untangling the Contradictions

Identification is a person's sense of belonging with a social category. Identification in virtual organizational teams is thought to be especially desirable because it provides the glue that can promote group cohesion despite the relative lack of face-to-face interaction. Though research on virtual teams is exploding, it has not systematically identified the antecedents or moderators of the process by which identification develops, leaving a number of gaps and apparent contradictions. The purpose of this paper is to begin to untangle the contradictions and address some of the gaps by tracing the mechanisms and moderating processes through which identification develops in hybrid and pure virtual settings, and the ways that these processes differ from face-to-face settings.
The P-M hybrid dysgenesis cline in Eastern Australian Drosophila melanogaster: discrete P, Q and M regions are nearly contiguous.

The dramatic latitudinal cline in P-M hybrid dysgenesis characteristics along the east coast of Australia is not smooth. Tests of recent collections of Drosophila melanogaster from the southeastern coast define the previously described cline as comprising three discrete, apparently contiguous regions of P, Q and M phenotypes, respectively. Northern populations from Cairns (16.9°SLat) to Ourimbah (33.4°SLat) are phenotypically P; populations from Wollongong (34.4°SLat) to Eden (37.1°SLat) are Q; and populations from Genoa (37.5°SLat) to Cygnet (43.2°SLat) are M. The decline in P activity from northern Queensland (55-60% gonadal dysgenesis (GD) in cross A) to mid-New South Wales (20-30% GD in cross A) is gradual; proceeding south, there then is a sharp drop to Q populations (<10% GD in crosses A and A*). This drop in P activity occurs in only 150 km, across the urban and suburban area of Sydney. Q populations are then found south to Eden, but Genoa, only about 50 km further southeast, is clearly M (48% GD in cross A*), as are two populations further south. The two discontinuities in the P-M cline do not correspond to obvious climatic differences along the coast, nor to obvious barriers to dispersal of D. melanogaster . The cline has apparently not moved between 1983 and 1985-1986.
Genital Human Papillomavirus Infection: Incidence and Risk Factors in a Cohort of Female University Students

Incidence data on human papillomavirus (HPV) infection are limited, and risk factors for transmission are largely unknown. The authors followed 603 female university students in Washington State at 4-month intervals between 1990 and 2000. At each visit, a sexual and health questionnaire was completed and cervical and vulvovaginal samples were collected to detect HPV DNA. At 24 months, the cumulative incidence of first-time infection was 32.3% (95% confidence interval: 28.0, 37.1). Incidences calculated from time of new-partner acquisition were comparable for enrolled virgins and nonvirgins. Smoking, oral contraceptive use, and report of a new male sex partner--in particular, one known for less than 8 months before sex occurred or one reporting other partners--were predictive of incident infection. Always using male condoms with a new partner was not protective. Infection in virgins was rare, but any type of nonpenetrative sexual contact was associated with an increased risk. Detection of oral HPV was rare and was not associated with oral-penile contact. The data show that the incidence of HPV associated with acquisition of a new sex partner is high and that nonpenetrative sexual contact is a plausible route of transmission in virgins.
IPO Returns: Pre And Post Dotcom Bubble

This study inspects the relative first-day returns of tech/internet IPOs before, during, and after the 1999-2000 dotcom “bubble” to investigate whether market inefficiency and agency conflicts were resolved. Using IPOs during the 1990 to 2004 period, we discover significant reversals in underpricing of internet IPOs following the large-scale investigation of IPO valuation practices led by New York State Attorney General Elliot Spitzer.
QSTEM-based HAADF-STEM image analysis of Mo/V distribution in MoVTeTaO M1 phase and their correlations with surface reactivity

Abstract Three probability models (Model 1–3) were advanced and investigated in this study based on metal distributions determined by the QSTEM-based HAADF-STEM image analysis. The correlations between the Mo/V distributions in MoVTeTaO M1 phase catalysts and their catalytic behavior in propane ammoxidation were proposed for Model 1 (based on the probability of finding 1–2 V5+ cations in the proposed S3-S4-S4-S7-S7 catalytic center), Model 2 (based on the total V content in the S2-S4-S4-S7-S7 catalytic center), and Model 3 (based on the probability of finding more than 2 V cations in the S2-S4-S4-S7-S7 catalytic center). Model 1 suggested V5+ in S3 may activate propane. Model 2 and Model 3 emphasized the importance of total V content and multiple VOx sites in the S2-S4-S4-S7-S7 catalytic center for catalytic reactivity in propane ammoxidation, respectively.
Un fragmento de la historia contemporánea. La bomba atómica y los físicos de Los Álamos

This article is a piece of contemporary history which shows the relationship between the odyssey of an immigrant Asturian, the Great Depression in America, the Spanish Civil War, some physicists at Los Alamos, the first atomic bomb and the nuclear test North Korea's October 2006. The bombs dropped on Hiroshima and Nagasaki in early August 1945 were developed in the laboratory at Los Alamos (New Mexico). The Manhattan Project brought together the best American and European scientists, including J. Robert Oppenheimer.