cssi/SciSciGPT-SciSciNet huggingface dataset:
Three-dimensional MEMS devices with functionalized carbon nanotubes

Carbon Nano Tubes (CNT) with their unique structure, have already proven to be valuable in their application as tips for scanning probe microscopy, field emission devices, nanoelectronics, H2- storage, electromagnetic absorbers, ESD, EMI films and coatings and structural composites. For many of these applications, highly purified and functionalized CNT which are compatible with many host polymers are needed. A novel microwave CVD processing technique to meet these requirements has been developed at Penn State Center for the Engineering and Acoustic Materials and Devices (CEEAMD). This method enables the production of highly purified carbon nano tubes with variable size (from 5-40 nm) at lost cost (per gram) and high yield. Whereas, carbon nano tubes synthesized using the laser ablation or arc discharge evaporation method always include impurity due to catalyst or catalyst support. The Penn State research is based on the use of zeolites over other metal/metal oxides in the microwave field for a high production and uniformity of the product. An extended conventional purification method has been employed to purify our products in order to remove left over impurity. A novel composite structure can be tailored by functionalizing carbon nano tubes and chemically bonding them with the polymer matrix e.g. block or graft copolymer, or even cross-linked copolymer, to impart exceptional structural, electronic and surface properties. Bio- and Mechanical-MEMS devices derived from this hybrid composite are presented.© (2001) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Resource Structure of Agriculture: An Economic Analysis

Resource structure of agriculture: an economic analysis , Resource structure of agriculture: an economic analysis , مرکز فناوری اطلاعات و اطلاع رسانی کشاورزی
Wavelength dependence of aerosol extinction coefficient for stratospheric aerosols

A simple empirical formula for the wavelength dependence of the aerosol extinction coefficient is proposed. The relationship between the constants in the formula and the variable parameter in the aerosol size distribution is explicitly expressed. Good agreement is found between the extinction coefficients calculated from the proposed formula and that calculated from Mie theory. The proposed expression is shown to be better than the Angstroem formula commonly used by atmospheric scientists.
Repression of the high‐methionine zein gene in the maize inbred line Mo17

Summary The methionine content in maize kernels is largely determined by the level of a methionine-rich 10 kDa protein, encoded by the gene Zps10/(22). In the maize inbred BSSS53 this gene is over-expressed compared with its normal expression in inbred lines like W64A and W22. This is in part due to the trans-acting factor Zpr10/(22). However, compared with the normal level of expression, this gene is under-expressed in the inbred Mo17 and the high-methionine zein accumulates to very low levels. Therefore, differential expression of this gene between BSSS53 and Mo17 is even larger than in other inbred lines of maize. Repression of 10 kDa zein expression in Mo17 is not due to the translatability of 10 kDa zein mRNA or a cis-acting mutation in the mRNA and neither is it due to a change in the transcription rate per se. However, steady state levels of mRNA appear to be controlled in trans by narrowing the developmental time frame of mRNA accumulation.
Kinetics of chlorination of niobium pentoxide by carbon tetrachloride

Kinetics of the chlorination of Nb2O5 powder by CCl4 vapor in mixture with N2 in a static bed in the temperature range of 698 to 853 K were carried out at different partial pressures of CCl4 (p CCl 4), varying from 0.10 to 0.75 atm. The fraction of Nb2O5 chlorinated R at p CCl 4 of 0.6 atm in the temperature range of 698 to 773 K was found to be proportional to time t, and the activation energy E is calculated to be 112 kJ/mole. Results on the effect of p CCl 4 (0.4, 0.6, and 0.75 atm) at 723 K suggest that the rate v (R/min) is proportional to p CCl 4 1.5. However, at p CCl 4 of 0.2 atm, R is not linear with t, rather, R 1/2 is linear with t. Based on these results, two mechanisms, one at low p CCl 4 (0.2 atm) and another at higher p CCl 4 values, in the temperature range of 698 to 773 K have been suggested. Similar studies in the higher temperature range (793 to 853 K), where p CCl 4 used to decompose to elemental chlorine and carbon, were also carried out. At all temperatures and p CCl 4 values, R is found to be directly proportional to t. At two higher p CCl 4 (0.4 and 0.6 atm), v is proportional to p CCl 4 1.5, whereas at two lower p CCl 4 (0.1 and 0.2 atm) it is proportional to p CCl 4 1.5. The E values obtained in the temperature range of 793 to 853 K at p CCl 4 of 0.6 and 0.2 atm are found to be 57 and 115 kJ/mole, respectively. In this higher temperature range, two different reaction mechanisms have been proposed.
Attending to the relational aspects of the faculty citation search

Faculty often request that academic librarians conduct online searches for citations to their publications. This article identifies challenges in the search process (e.g., the psychological stress of the faculty and role reversal) and offers recommendations for responding to these challenges and enhancing relationships with the faculty.
Late-Holocene teleconnections between tropical Pacific climatic variability and precipitation in the western USA: evidence from proxy records:

Decadal to multidecadal fluctuations between drought and relatively more moist conditions are a defining characteristic of precipitation variability in the western USA. In an attempt to better understand the forcing mechanisms responsible for producing this variability, relationships between proxy indices of tropical climatic variability and precipitation-related reconstructions in the western USA are examined. The tropical proxies include the δ¹⁸O record from the Quelccaya ice cap (southern subtropical Andes) and the lacustrine sedimentation record from Laguna Pallcacocha (near-equatorial Andes). The precipi tation-related records are tree-ring reconstructions of river flow, drought severity and precipitation over the contiguo USA. One new finding is a consistent relation between decadal variability in El Ninno activity and precipitation-related proxies through much of the western USA during the past 1200 years. Surpris ingly, the proxy records do not show a systematic link between inferred El Ninno activity and precipitation in the interior Southwest USA. A second new result is the existence of relationships at decadal to multidecadal timescales between fluctuations in Quelccaya δ¹⁸O, precipitation-related proxies from the western USA, and proxy records from the Pacific Basin. This finding links the Quelccaya record to the transhemi spheric Pacific decadal-scale climatic variability documented from proxy records by Villalba et al. (2001), and suggests that similar changes in the large-scale circulation changes accompany both the decadal and multidecadal signals. A composite constructed using gridded proxy precipitation constructed on the basis of decadal-scale fluctuations in inferred-El Ninno activity shows a pattern rather different to Ninno-based teleconnection maps for the instrumental record. In the proxy-based composite, positive values cover much of the extreme western, west central and southeastern USA, with negative values in the central Mis sissippi Valley. The interior Southwest shows essentially no response. A second composite based on multi decadal variability in Quelccayaδ¹⁸O shows a well-developed dipole pattern across the western USA with opposing centres in the interior Southwest and Northwest. It is suggested that this dipole pattern results from multidecadal variability in tropical Pacific SSTs and resulting changes in the strength of the Northeast Pacific High and the latitudinal distribution of cool season westerlies across the eastern North Pacific and western USA.
Contraction with and without demonstrable splitting of energy-rich phosphate in turtle muscle.

Abstract In a reinvestigation, the finding that turtle muscles can contract without demonstrably splitting phosphocreatine has been confirmed, specifically for the sartorius muscle. Even during a recovery period of about 10 sec after contraction, no phosphocreatine utilization could be demonstrated. However, a second period of contractile activity showed a formation of creatine, although not of phosphate. By contrast, the rectus femoris muscle was found to split creatine phosphate, and was quantitatively comparable in this regard to the frog sartorius.
A Link-Node Discrete-Time Dynamic Second Best Toll Pricing Model with a Relaxation Solution Algorithm

Dynamic congestion pricing has become an important research topic because of its practical implications. In this paper, we formulate dynamic second-best toll pricing (DSBTP) on general networks as a bilevel problem: the upper level is to minimize the total weighted system travel time and the lower level is to capture motorists’ route choice behavior. Different from most of existing DSBTP models, our formulation is in discrete-time, which has very distinct properties comparing with its continuous-time counterpart. Solution existence condition of the proposed model is established independent of the actual formulation of the underlying dynamic user equilibrium (DUE). To solve the bilevel DSBTP model, we adopt a relaxation scheme. For this purpose, we convert the bilevel formulation into a single level nonlinear programming problem by applying a link-node based nonlinear complementarity formulation for DUE. The single level problem is solved iteratively by first relaxing the strick complementarity by a relaxation parameter, which is then progressively reduced. Numerical results are also provided in this paper to illustrate the proposed model and algorithm. In particular, we show that by varying travel time weights on different links, DSBTP can help traffic management agencies better achieve certain system objectives. Examples are given on how changes of the weights impact the optimal tolls and associated objective function values.
Agrobacterium: nature’s genetic engineer

Agrobacterium was identified as the agent causing the plant tumor, crown gall over 100 years ago.Since then, studies have resulted in many surprising observations. Armin Braun demonstrated that Agrobacterium infected cells had unusual nutritional properties, and that the bacterium was necessary to start the infection but not for continued tumor development. He developed the concept of a tumor inducing principle or TIP, the factor that actually caused the disease. Thirty years later the TIP was shown to be a piece of a tumor inducing (Ti) plasmid excised by an endonuclease. In the next 20 years, most of the key features of the disease were described. The single stranded DNA (T-DNA) with the endonuclease attached is transferred through a type IV secretion system into the host cell where it is coated and protected from nucleases by a bacterial secreted protein,VirE2. A nuclear localization signal in the endonuclease guides the T-strand into the nucleus where it is integrated randomly into the host chromosome. Other secreted proteins likely aid in uncoating the T-complex. The genes associated with T-strand formation and transfer (vir) map to the Ti plasmid and are only expressed when the bacteria are at a plant’s wound site. Plant signals are recognized by a two-component system which activates vir genes. However, chromosomal genes with pleiotrophic functions also play important roles in plant transformation. The T-DNA encodes enzymes of auxin, cytokinin and opine synthesis, the latter a food source for Agrobacterium. The data now explain Braun’s observations made 75 years ago and also explain why Agrobacterium is Nature’s Genetic Engineer. Since any DNA inserted between the border sequences which define the T-DNA will be transferred and integrated into host cells, Agrobacterium has become the major vector in plant genetic engineering.
An examination of associations between social norms and risky alcohol use among African American men who have sex with men

Abstract Background Research has indicated associations between risky alcohol consumption and sexual risk behavior, which may in turn present risk of HIV acquisition or transmission. Little is known about social determinants of problematic alcohol use among African American MSM (AA MSM), a risk group disproportionately affected by HIV. The present study sought to explore associations between risky alcohol use and perceived peer norms of alcohol use among a sample of urban African American men who have sex with men (AA MSM). Methods A cross-sectional survey was administered to 142 AA MSM in Baltimore, Maryland, recruited using active and passive methods. Risky and hazardous alcohol use was assessed using the Alcohol Use Disorders Identification Test (AUDIT) and participants self-reported descriptive and injunctive peer norms regarding frequency and quantity of alcohol consumption. Results Nearly half reported hazardous or high risk consumption of alcohol. Perceived peer alcohol norms, both descriptive and injunctive, were associated with alcohol use, including hazardous use. Conclusions The findings highlight the role of social factors on problematic alcohol use among AA MSM. Results indicate that AA MSM's use of alcohol is associated with their perceptions of peer alcohol use. Potential interventions could include norms-based campaigns that seek to reduce risky alcohol consumption among AA MSM as well as programs to screen and identify individuals with problematic alcohol use.
Aspects of canine distemper virus and measles virus encephalomyelitis

Canine distemper (CD) is a frequently fatal, systemic morbillivirus infection in the dog and other carnivores: encephalomyelitis is the common cause of death. Susceptibility to canine distemper virus (CDV) is now recognized in a wide range of non-domestic animals, most recently in captive lions, tigers and leopards. Furthermore, closely related viruses have produced CD-like diseases in marine mammals. CDV induces an inclusion-body encephalomyelitis in the dog and demyelination is often a conspicuous feature. Myelin injury is associated with the presence of virus but the mechanism of demyelination remains incompletely understood. Oligodendrocyte infection may be defective, as has been shown in vitro. CDV and measles virus (MV) produce similar systemic disorders in their respective hosts but differ markedly in the frequency of central nervous system (CNS) involvement, and in the pathogenesis of the more common neurological sequelae. Both CDV and MV have been considered as multiple sclerosis agents, and the association of CDV with other human disease has been suggested.
Structural effects of the lone pair on lead(II), and parallels with the coordination geometry of mercury(II). Does the lone pair on lead(II) form H-bonds? Structures of the lead(II) and mercury(II) complexes of the pendant-donor macrocycle DOTAM (1,4,7,10-tetrakis(carbamoylmethyl)-1,4,7,10-tetraazacyclododecane).

The synthesis and structures of [Pb(DOTAM)](ClO4)2·4.5H2O (1) and [Hg(DOTAM)](ClO4)2·0.5CH3OH·1.5H2O (2) are reported, where DOTAM is 1,4,7,10-tetrakis(carbamoylmethyl)-1,4,7,10-tetraazacyclododecane. Compound 1 is triclinic, space group P1, a = 12.767(3) A, b = 13.528(2) A, c = 18.385(3) A, α = 101.45(2)°, β = 93.32(2)°, γ = 90.53(2)°, Z = 4, R = 0.0500. Compound 2 is monoclinic, space group Cc, a = 12.767(3) A, b = 13.528(2) A, c = 18.385(3) A, β = 101.91(2)°, Z = 4, R = 0.0381. The Pb(II) ion in 1 has an average Pb−N = 2.63 A to four N-donors from the macrocyclic ring, and four O-donors (average Pb−O = 2.77 A) from the amide pendant donors of the macrocycle, with a water molecule placed with Pb−O = 3.52 A above the proposed site of the lone pair (Lp) on Pb. The Hg(II) in 2 appears to be only six-coordinate, with four Hg−N bond lengths averaging 2.44 A, and two Hg−O from pendant amide donors at 2.41 A. The other two amide donors appear to be noncoordinating, with Hg−O distances of 2.74 and 2.82 A. A wa...
Locating the minimum of a function when the errors of observation have unknown density

In considering the problem of locating the point θ at which a functionf achieves its minimum (or maximum) using the Kiefer-Wolfowitz (KW) stochastic approximation procedure, Abdelhamid [1] has shown that if the densityg of the errors obtained in estimating functional values is known, then a transformation of observations leads to methods which under mild conditions have desirable asymptotic properties. We address the more general problem of locating the point of minimum of a function wheng is unknown to the experimenter. In the procedure given in Theorem 4.1 we obtain the same asymptotic results as Abdelhamid in his version of the KW procedure.
Computer Analysis Of Computed Tomographic (CT) Scan Images For Tissue Densitometry

A software system has been developed to support analysis of CT images for tissue densitometry. Analysis can be done on either whole organ areas in a slice open subregions of these areas. CT numbers can he calibrated to absolute density. The system has been used to analyze lung and liver density in animal studies and lung density in a limited number of patients.
Atlas of the Spectrum of a Platinum/Neon Hollow-Cathode Reference Lamp in the Region 1130-4330 a

The spectrum of a platinum hollow-cathode lamp containing neon carrier gas was recorded photographically and photoelectrically with a 10.7 m normal-incidence vacuum spectrograph. Wavelengths and intensities were determined for about 5600 lines in the region 1130-4330 A. An atlas of the spectrum is given, with the spectral lines marked and their intensities, wavelengths, and classifications listed. Lines of impurity species are also identified. The uncertainty of the photographically measured wavelengths is estimated to be ± 0.0020 A. The uncertainty of lines measured in the photoelectric scans is 0.01 A for wavelengths shorter than 2030 A and 0.02 A for longer wavelengths. Ritz-type wavelengths are given for many of the classified lines of Pt II with uncertainties varying from ±0.0004 to ± 0.0025 A. The uncertainty of the relative intensities is estimated to be about 20%.
Programmable applications for the arts: computational tools for hand, eye and mind

Abstract Commercial applications for the arts tend to enforce a division between the use of learnable direct manipulation interfaces and the use of powerful, well supported programming environments. In contrast, programmable applications integrate these two software-design paradigms (i.e. direct manipulation and programming languages) and thereby attempt to exploit the strengths of both. A sample graphics application, SchemePaint, is outlined, and some of the issues related to the creation of programmable applications for the arts are discussed.
Efficient line search algorithm for unconstrained optimization

A new line search algorithm for smooth unconstrained optimization is presented that requires only one gradient evaluation with an inaccurate line search and at most two gradient evaluations with an accurate line search. It terminates in finitely many operations and shares the same theoretical properties as the standard line search rules like the Armijo-Goldstein-Wolfe-Powell rules. This algorithm is especially appropriate for the situation when gradient evaluations are very expensive relative to function evaluations.
Activation of actin polymerization by phosphatidic acid derived from phosphatidylcholine in IIC9 fibroblasts.

alpha-Thrombin induced a change in the cell morphology of IIC9 fibroblasts from a semiround to an elongated form, accompanied by an increase in stress fibers. Incubation of the cells with phospholipase D (PLD) from Streptomyces chromofuscus and exogenous phosphatidic acid (PA) caused similar morphological changes, whereas platelet-derived growth factor (PDGF) and phorbol 12-myristate 13-acetate (PMA) induced different changes, e.g., disruption of stress fibers and cell rounding. alpha-Thrombin, PDGF, and exogenous PLD increased PA by 20-40%, and PMA produced a smaller increase. alpha-Thrombin and exogenous PLD produced rapid increases in the amount of filamentous actin (F-actin) that were sustained for at least 60 min. However, PDGF produced a transient increase of F-actin at 1 min and PMA caused no significant change. Dioctanoylglycerol was ineffective except at 50 micrograms/ml. Phospholipase C from Bacillus cereus, which increased diacylglycerol (DAG) but not PA, did not change F-actin content. Down-regulation of protein kinase C (PKC) did not block actin polymerization induced by alpha-thrombin. H-7 was also ineffective. Exogenous PA activated actin polymerization with a significant effect at 0.01 microgram/ml and a maximal increase at 1 microgram/ml. No other phospholipids tested, including polyphosphoinositides, significantly activated actin polymerization. PDGF partially inhibited PA-induced actin polymerization after an initial increase at 1 min. PMA completely or largely blocked actin polymerization induced by PA or PLD. These results show that PC-derived PA, but not DAG or PKC, activates actin polymerization in IIC9 fibroblasts, and indicate that PDGF and PMA have inhibitory effects on PA-induced actin polymerization.
Numerical Simulation of Transient Thermoreflectance of Thin Films in The Picosecond Regime

internal reflections caused by the spatial temperature field significantly affect the accuracy ofthe methodin some materials. The internal reflection mechanism alters the temperature field as compared to thatpredicted without it. Criteria to define the range ofimportance ofthe internal reflection mechanism havebeen developed based on these assumptions. These results are extended using numerical analysis toinvestigate the effects ofan incident Guassian beam instead ofuniform irradiation. The code includesmechanisms to describe the temperature and intensity dependent absorption coefficients and index ofrefraction. It is found that the two-dimensional effects decrease the one dimensional normalizedreflectance change by 24%. A technique for the incorporating the code into the analysis ofthe PTTR is
President's Budget Proposal Favors NSF, Though Congress Could Push for Reductions

[1] The U.S. National Science Foundation (NSF) is one of the winners in the Obama administration's proposed budget for fiscal year (FY) 2012, which begins on 1 October, with a proposed funding level of $7.767 billion; this would be an increase of 13% above the congressionally enacted FY 2010 budget level. However, the administration's proposed budget is just a starting point for discussions. Congress has approved a 2-week budget continuing resolution (CR) for the current fiscal year, 2011. A longer-term CR passed by the House of Representatives (HR 1) could dramatically cut this year's funding for some federal agencies and also affect budget discussions for FY 2012.
Why Does My Patient Have Erythrocytosis

The term polycythemia comes from the Greek, meaning too many cells in the blood, and refers to an increase in the red cell mass; it is frequently used interchangeably with the term erythrocytosis. Polycythemia may have several causes, and can be classified as relative or absolute. 1 Relative polycythemia occurs when the patient has a modest increase of the hematocrit level without an increased red cell mass caused by contraction of the plasma volume. Absolute polycythemia is accompanied by an increase in the circulating red cell mass. Red cell production can be influenced by numerous factors including nutrients, growth factors, numbers, and function of marrow progenitor and precursor cells, as well as cellular receptors and transcription factors. 2 The hematopoietic growth factor erythropoietin (EPO) is considered to be the physiologic regulator of the terminal phases of erythropoiesis. 3 Alterations in its production are followed by adjustments in the rate of formation of red blood cells. Hematocrit values more than 52% in men and more than 48% in women are abnormal and require further investigation into their causes. Polycythemic states can also be divided into primary or secondary polycythemias (Box 1). Primary polycythemias are the result of intrinsic abnormalities of the hematopoietic progenitors and stem cells that lead to constitutive overproduction of red cells accompanied by low EPO levels. Secondary polycythemias can be a result of several conditions causing increased EPO production, which acts on normal progenitors to increase the red cell production. These conditions can usually be distinguished by in vitro assays of erythroidprogenitor cells,measurementofserumEPOlevels, anddetectionof somatic JAK2 mutations. In a small number of patients, the cause of eythrocytosis cannot be determined, and these patients are classified as having idiopathic erythrocytosis.
Distribution, host specificity, and overwintering of Celatoria bosqi Blanchard (Diptera: Tachinidae), a South American parasitoid of Diabrotica spp. (Coleoptera: Chrysomelidae: Galerucinae)

The genus Diabrotica (Coleoptera: Chrysomelidae) includes a great number of pest species, including some of the most important crops pests of the Americas. However, only five parasitoid species have been recorded for it. The parasitoid Celatoria bosqi Blanchard was the first parasitoid described from Diabrotica spp. in South America, where substantial parasitism has been observed. C. bosqi has been collected almost throughout the South American distribution of its main host, Diabrotica speciosa (Germar), in an area that includes temperate and tropical lowlands, and semiarid to humid highlands. Three Diabrotica species were found to host the parasitoid, D. speciosa (Germar), Hystiopsis sp., and Diabrotica viridula (F.), with a total parasitism of 2.60, 5.55, and <0.02%, respectively. Laboratory experiments with field beetles and puparia, reared in the laboratory, indicate that C. bosqi overwinters obligatorily in overwintering adult host beetles, remaining quiescent in its live host below developmental temperatures. Based on the known climatic range of C. bosqi, and its requirement of adult overwintering hosts, a potential distribution in North America is projected.
A Sweep Algorithm and its Implementation: The All-Nearest-Neighbors Problem Revisited

The 2-dimensional all-nearest-neighbors problem is solved directly in asymptotically optimal time O(n*log n) using a simple plane-sweep algorithm. We present the algorithm, its analysis, an optimization based on the concept of a clipped computation, and describe two robust realizations: a "foolproof" implementation which guarantees an exact result at the cost of using five-fold-precision rational arithmetic, and a robust floating point version.
A Low-Power Fully Implantable 15-Channel Retinal Stimulator Chip

Retinal prostheses are being developed around the world in hopes of restoring useful vision for patients suffering from certain types of diseases like age-related macular degeneration (AMD) and retinitis pigmentosa. The central component of an electrical retinal prosthesis is a wirelessly powered and driven stimulator chip. The chip receives commands from the outside and outputs biphasic current pulses to an electrode array placed in the retina that stimulate the remaining retinal neurons. The chip contains 30\thinspace000 transistors in a 0.5 mum technology (two-poly three-metal, 2P3M), occupies an area of 2.3 mm x 2.3 mm, and excluding the current sources consumes less than 2 mW of power. The chip is powered inductively via a 125 kHz power signal which is rectified to generate a plusmn2.5nV supply. The data signal is transmitted as an amplitude shift keyed (ASK) signal on a 13.56 MHz carrier. The data rate can be varied from 25 to 714 kHz and the symbol (0 or 1) is encoded as the pulse width of the data signal. A self-biased feedback-loop-based single-to-differential converter restores the signal to full rail levels. Clock and data recovery is performed by a self-biased low-power inverter-based delay-locked loop (DLL). The chip can receive four commands, and each command is 16 bits long. The current amplitude, pulse duration, and inter-pulse duration can be programmed by using the four commands.
The Eastern City Gun Project: Exploring Contextual and Operational Variables

To maintain public safety and improve system response, a strong need exists for understanding the contexts of and police response to weapon-related incidents as well as socio-economic variables of individuals involved. This paper was focused on exploring these contexts and routine police activities by creating and analyzing a weapon-related database at the local level. The findings, although limited due to the explorative nature of the study and the quality of case files, shed some interesting light on the effects of environmental and operational variables on gun incidents and expose certain issues that need to be resolved before further and more accurate understanding of gun crimes at the local level can be achieved.
Stored light in optical fibers via stimulated Brillouin scattering

We report a new method for storing and retrieving sequences of optical data pulses via induced acoustic excitations in an optical fiber through the process of stimulated Brillouin scattering.
Simulation of five large round bale harvesting systems for biomass

Abstract The production of herbaceous biomass as a feedstock for fiber conversion is an equipment-based enterprise, meaning that, above some yield threshold, harvest/handling/hauling equipment productivity has more impact on delivered cost than land productivity. Performance of five large round bale harvest systems was simulated assuming an idealized harvest opportunity (field efficiency 80%, no weather delays, no maintenance delays). Round balers produce a lower density bale when baling a heavier windrow, and this factor had a significant effect on harvest cost. Baler achieved capacity is maximized when hay (15% M.C.) in the windrow is between 2.2 and 3.6 kg/m. At higher windrow densities, the bales produced have a lower density (mass) and total wrap-eject time as a percentage of field time increases; consequently, baler productivity (Mg/h) decreases and cost per bale increases. A raking strategy was selected to produce a windrow with a material density of at least 2.2 kg/m. If one rake swath produced a windrow with less than 2.2 kg/m, two rake swaths were combined and so forth until the 2.2 kg/m density was reached. Using this strategy, total harvest cost was kept almost constant as yield increased up to 12 dry Mg/ha. As yield increased from 12 to 18 dry Mg/ha, total harvest cost increased from $16.65 to $20.00/dry Mg, or 20%. (Only in-field costs were computed, therefore the simulation costs are lower than current commercial practice.) Increases in yield above some optimum (12 dry Mg/h based on simulation results) will not reduce per-Mg harvest cost, and there is strong evidence to suggest cost will increase. A second factor significantly affecting harvest cost was annual operating hours. Suppose two grass species are planted and these species are harvested at different times. If the two-grass strategy allows an operator to double productive machine hours from 200 to 400 h/yr, per-Mg harvest cost is reduced 10%. Production management decisions, e.g. selection of grass species and management for multi-cut harvests, can increase potential harvest days during the season. An increase in harvest days reduces per-Mg harvest costs, but more importantly, increases Mg/yr/machine. The simulations showed that return on equipment investment increased 174% when annual operating hours increased from 200 to 400 h/yr.
Risk factors for restenosis after carotid artery angioplasty and stenting.

Objectives With carotid artery stenting (CAS) becoming an ever-increasing procedure, we sought to determine risk factors for in-stent restenosis after CAS. Methods Consecutive patients undergoing CAS between January 2002 and October 2004 at a tertiary care hospital were retrospectively reviewed. Patient, filter, and stent selection were left to the discretion of the attending surgeon. High-risk patients were defined by significant comorbidities or a hostile neck (prior surgery or radiation, or both), and risk factor analysis was performed. In-stent restenosis was defined as >60%, and selective angiography was performed on patients with an in-stent restenosis >80% by duplex ultrasound imaging. Results Reviewed were 101 patients (55 men, 46 women) who underwent 109 CAS procedures. Comorbidities were typical for patients with atherosclerosis. In addition, 38% (n = 41) of procedures were performed in patients who had prior neck surgery, of which 29% (n = 32) had previous ipsilateral carotid endarterectomy. Seventeen patients (16%) had a history of neck cancer, and all had prior neck radiation. Median follow-up was 5 months (range, 0 to 30 months). Neurologic complications included three transient ischemic attacks (2.8%) and one nondisabling stroke (0.9%). There were two myocardial infarctions (1.9%) and no periprocedural deaths (30 days), for a combined stroke, myocardial infarction, and death rate of 2.9%. Asymptomatic in-stent restenosis developed in 12 carotids (11%), five of which required endovascular intervention, with a mean of 6 months to restenosis. Univariate Cox proportional hazard regression models were used to determine risk factors for the development of restenosis. Prior stroke, transient ischemic attack, amaurosis fugax, and prior neck cancer were all significant risk factors. When these significant risk factors from univariate analysis were put into multivariate analysis, however, the only marginally significant risk factor was prior neck cancer ( P = .06). Kaplan-Meier analysis revealed a cumulative freedom from in-stent restenosis at 24 months of 88% ± 6% in patients without neck cancer compared with 27% ± 17% ( P = .02) in patients with neck cancer. Conclusions CAS has been shown to be safe and effective in high-risk patients, with minimal adverse events.
Chemotherapy-induced cognitive impairment is associated with decreases in cell proliferation and histone modifications

In this study, we examined the effects of cyclophosphamide, methothrexate, and 5-Fluorouracil (CMF) drug combination on various aspects of learning and memory. We also examined the effects of CMF on cell proliferation and chromatin remodeling as possible underlying mechanisms to explain chemotherapy-associated cognitive dysfunction. Twenty-four adult female Wistar rats were included in the study and had minimitter implantation for continuous activity monitoring two weeks before the chemotherapy regimen was started. Once baseline activity data were collected, rats were randomly assigned to receive either CMF or saline injections given intraperitoneally. Treatments were given once a week for a total of 4 weeks. Two weeks after the last injection, rats were tested in the water maze for spatial learning and memory ability as well as discrimination learning. Bromodeoxyuridine (BrdU) injection was given at 100 mg/Kg intraperitoneally 4 hours prior to euthanasia to determine hippocampal cell proliferation while histone acetylation and histone deacetylase activity was measured to determine CMF effects on chromatin remodeling. Our data showed learning and memory impairment following CMF administration independent of the drug effects on physical activity. In addition, CMF-treated rats showed decreased hippocampal cell proliferation, associated with increased histone acetylation and decreased histone deacetylase activity. These results suggest the negative consequences of chemotherapy on brain function and that anti-cancer drugs can adversely affect the self-renewal potential of neural progenitor cells and also chromatin remodeling in the hippocampus. The significance of our findings lie on the possible usefulness of animal models in addressing the clinical phenomenon of 'chemobrain.'
Medical school and the process of disillusionment

Summary A pilot study of the 1970 graduating class of Yale Medical School revealed that a group of medical students could be defined who seemed particularly dissatisfied with themselves and their profession (Schwartz & Slaby, 1971). For the most part, these medical students differed from their peers in that they contemplated an alternative career in the arts or letters and, while they retained many of the values of their colleagues, they differed from them in such a way as to convey the impression that they were more uncertain about their identity. The study dealt with these medical students at the point in their career at which they were about to become doctors. It seemed appropriate, as part of our larger study, in which we are attempting to follow changing values and patterns of behaviour among various groups of professionals and professional students (Slaby & Schwartz, 1971), to collect data on medical students during each of the 4 years of medical school. It was our purpose to determine whether the group of uncertain students comprised those students who had been in conflict about being at medical school and about their future role in medicine since their entrance into medical school, or whether the process of disenchantment evolved during the course of medical training. We explored if this process affected susceptible students during their clinical or pre-clinical years, and report some of the manifestations of this disaffection.
Alternative Approaches to Incorporating the Opportunity Cost of Time in Recreation Demand Models

The importance of accounting for a respondent’s travel time in recreation demand models is well established. In practice, most analysts use a fixed fraction of the respondent’s wage rate to value travel time. However, other approaches have been suggested in the literature. In this paper revealed and stated preference data on Iowa wetland usage is used to explore various specifications of travel time. It is shown that the choice of a particular specification has a direct impact on welfare estimates as well as the consistency between revealed and stated preference data.
The "random-coil" state of proteins: comparison of database statistics and molecular simulations.

This study presents a comparison of two models of the random-coil state, one based on statistical distributions from the structural database and the other based on molecular dynamics simulations. The database model relies on the assumption that the random- or statistical-coil state of a particular residue can be described by its conformational distribution in a sufficiently diverse subset of protein structures. The molecular dynamics model is based on distributions from molecular simulations carried out on “dipeptide” models (single residues with N-terminal acetyl and C-terminal N′-methyl amide blocking groups). A comparison of the two models for the residues Ala, Asn, Asp, Gly, and Val indicates that the database distributions are greatly influenced by long-range interactions and dominated by specific recognizable elements of protein structure. In contrast, the limited structural scope of the dipeptide models presents the extreme case of a peptide under the influence of only short-range interactions. The models were evaluated by a comparison of scalar coupling constants calculated from the conformational distributions and compared with experimentally values determined for unstructured peptides. Although the models gave different distributions, there was similar agreement with experiment. This comparison emphasizes the differences and limitations in each model and highlights the difficulty in presenting an accurate picture of the random-coil state. Proteins 1999;36:407– 418. © 1999 Wiley-Liss, Inc.
Transient Flow to a Horizontal Water Well

Equations that approximately relate the transient head in a horizontal well to a constant well discharge are selected from the petroleum literature and converted from the notation and eclectic system of units used in the oil industry to ground water notation with consistent units. A homogeneous but not necessarily isotropic aquifer is assumed. Depending on the time since the start of discharge, the equations are basically the same in form as for flow to either a fully penetrating channel or to a vertical well, but they contain an additional term accounting for vertical flow. A modification is introduced to make the equations, which were derived for confined flow, approximately applicable to unconfined ground water conditions. The simple form of the equations makes their use practical.
Particulate arsenic and iron during anoxia in a eutrophic, urban lake.

The bioavailability and transport of particle-reactive pollutants are influenced by their partitioning between dissolved and particulate phases. We explored the importance of particle complexation to the arsenic cycle in an urban lake (Upper Mystic Lake, eastern MA, USA) that experiences arsenic remobilization from contaminated sediments during seasonal hypolimnetic anoxia. Particle size distributions were measured using a new in situ serial filtration system that excludes oxygen and filters at low flow rates to minimize filtration artifacts. Despite anoxia, the majority of remobilized As was present as As(V), and typically 85 to 95% of total As was particle complexed, with 25 to 50% found in the size fraction between 0.4 and 0.05 μm. Iron was distributed similarly among these size classes (>95% of total Fe associated with particles larger than 0.05 μm, 30 to 50% between 0.4 μm and 0.05 μm), contrary to conventional expectation that the majority of Fe should be present as soluble Fe(II) in anoxic waters. By classical filtration (i.e., through a 0.4-μm filter), the colloidal fractions of both Fe and As would have been inaccurately classified as dissolved. Correlations between depth profiles of total As and particulate Fe as well as comparisons of measured arsenic sorption (i.e., total As > 0.05 μm) against predictions by surface complexation modeling of As on amorphous Fe(III) oxides argue that arsenic sorbed on Fe(III) oxides was the major As species present in this lake's hypolimnion throughout several months of anoxia.
TERRITORY SIZE AND SHAPE IN FIRE ANTS: A MODEL BASED ON NEIGHBORHOOD INTERACTIONS

Many aggressive animals form territory mosaics marked by distinct boundaries. This paper describes an approach to modeling territory size and shape within mosaics based on boundary disputes among neighboring animals. The model assumes that each resident applies pressure against its neighbors, as a result of aggression and display, and that boundaries form curves along which the pressure exerted by adjacent residents is equal. To illustrate, I predicted territory boundaries for populations of the fire ant Solenopsis invicta using several alternative mathematical descriptions of territorial fighting. According to the most successful formula, the aggressive pressure applied at any point on the territory perimeter increases linearly with the biomass of the defending colony but decreases with territory area and with the square of the distance to the colony’s nest. An iterative algorithm predicts the size and location of boundary segments given the positions and sizes of colonies. By all measured criteria, this...
Resonance Raman spectroscopy as a probe of the bis(μ-oxo)dicopper core

Resonance Raman spectra of dicopper complexes [L2Cu2(μ-O)2]2+ contain a number of resonance-enhanced features between 500 and 900 cm-1, with L = R3TACN and various bidentate ligands (TACN = 1,4,7-triazacyclononane). Most importantly, there is a vibration near 600 cm-1 in all [L2Cu2(μ-O)2]2+ compounds that is polarized, shifts by 19−27 cm-1 upon 18O2 substitution, and gives a new peak with 16O18O substitution, identifying it as a totally symmetric Ag vibration of the bis(μ-oxo)dicopper(III) core. Changing the pendant groups on R3TACN causes shifts in the frequency of the Cu2(μ-O)2 vibration, but the direction of these shifts depends on the details of the organic fragment. A substantial shift to higher frequency is evident when bidentate ligands are used in place of TACN. Importantly, bidentate ligands with two different types of nitrogen donors show two independent core vibrations; these are assigned as “breathing” and “pairwise” modes through simple group theory considerations as well as by calculations u...
“Bag of keypoints”-based biomedical image search with affine covariant region detection and correlation-enhanced similarity matching

This paper presents a “bag of keypoints” based biomed-ical image retrieval approach by detecting affine covariant regions. These regions refers to a set of pixels or interest points which are invariant to affine transformations, as well as occlusion, lighting and intra-class variations. The interest points are described with the Scale-Invariant Feature Transform (SIFT) and vector quantized to build a visual vocabulary of keypoints. By mapping the interest points extracted from one image to the keypoints in the vocabulary, their occurrences are counted and the resulting histogram is called the “bag of keypoints” for that image similar to the “bag of words” based representation of documents in text retrieval. To exploit the correlations between the keypoints in the collection, a global similarity matrix is constructed to be utilized in a distance measure function to compare the query and database images. A systematic evaluation retrieval results on a biomedical image collection demonstrates around 10–15% improvement in precision at different recall levels for the keypoint-based representation along with the correlation-enhanced distance measure when compared to individual color, texture, edge-related features.
Melatonin induction of filamentous structures in non-neuronal cells that is dependent on expression of the human mt1 melatonin receptor.

Melatonin has gained recent popularity as a treatment for insomnia and other sleep disorders; however, its cellular effects are unknown. We report the effects of melatonin on the cellular morphology of Chinese hamster ovary (CHO) cells transformed to express the human melatonin receptors, mt1 and MT2. Our results show that melatonin exerts a strong influence on cellular shape and cytoskeletal organization in a receptor-dependent and possibly subtype-selective manner. The cell shape change that we see after a 5-h treatment of these non-neuronal cells with a pharmacological concentration of melatonin consists of the formation of long filamentous outgrowths that are reminiscent of the neurite processes produced by differentiating nerve cells. This morphological change occurs exclusively in cells expressing the mt1 receptor. We find that the microtubule and microfilament organization within these outgrowths is similar to that of neurites. Microtubules are required for the shape change to occur as Colcemid added in combination with melatonin completely blocks outgrowth formation. We demonstrate that the number of cells showing the altered cell shape is dependent on melatonin concentration, constant exposure to melatonin and that outgrowth frequencies increase when protein kinase A (PKA) is inhibited. Concomitant melatonin-dependent increases in MEK 1/2 and ERK 1/2 phosphorylation are noted in mt1-CHO cells only. The production of filamentous outgrowths is dependent on the translation of new protein but not the transcription of new mRNA. Outgrowth number is not controlled by centrosomes but is instead controlled by the polymerization state of the actin cytoskeleton. The results of this work show that the organization of the cytoskeleton is affected by processes specifically mediated or regulated by the mt1 receptor and may represent a novel alternative mechanism for the stimulation of process formation.