Maximum likelihood Linear Programming Data Fusion for Speaker Recognition

Biometric system performance can be improved by means of data fusion. Several kinds of information can be fused in order to obtain a more accurate classification (identification or verification) of an input sample. In this paper we present a method for computing the weights in a weighted sum fusion for score combinations, by means of a likelihood model. The maximum likelihood estimation is set as a linear programming problem. The scores are derived from a GMM classifier working on a different feature extractor. Our experimental results assesed the robustness of the system in front a changes on time (different sessions) and robustness in front a change of microphone. The improvements obtained were significantly better (error bars of two standard deviations) than a uniform weighted sum or a uniform weighted product or the best single classifier. The proposed method scales computationaly with the number of scores to be fussioned as the simplex method for linear programming.

Influence of the diketonato ligand on the cytotoxicities of [Ru(eta(6)-p-cymene)-(R(2)acac)(PTA)](+) complexes (PTA=1,3,5-triaza-7-phosphaadamantane)

A series of compounds of general formula [Ru(eta(6)-p-cymene) (R(2)acac)(PTA)][X] (R(2)acac = Me(2)acac, tBu(2)acac, Ph(2)acac, Me(2)acac-Cl; PTA = 1,3,5-triaza-7-phosphaadamantane; X = BPh4, BF4), and the precursor to the Me2acac-Cl derivative [Ru(eta(6)-p-cymene)(Me(2)acac-Cl)Cl], have been prepared and characterised spectroscopically. Five of the compounds have also been characterised in the solid state by X-ray crystallography. The tetrafluoroborate salts are water-soluble, quite resistant to hydrolysis, and have been evaluated for cytotoxicity against A549 lung carcinoma and A2780 human ovarian cancer cells. The compounds are cytotoxic towards the latter cell line, and relative activities are discussed in terms of hydrolysis (less important) and lipophilicity, which appears to exert the dominating influence.

Investigation of Rapid Thermal Analysis Procedures for Prediction of the Service Life of PCCP Carbonate Coarse Aggregate, HR-337, 1993

The major objective of this research project was to use thermal analysis techniques in conjunction with x-ray analysis methods to identify and explain chemical reactions that promote aggregate related deterioration in portland cement concrete. Twenty-two different carbonate aggregate samples were subjected to a chemical testing scheme that included: • bulk chemistry (major, minor and selected trace elements) • bulk mineralogy (minor phases concentrated by acid extraction) • solid-solution in the major carbonate phases • crystallite size determinations for the major carbonate phases • a salt treatment study to evaluate the impact of deicer salts Test results from these different studies were then compared to information that had been obtained using thermogravimetric analysis techniques. Since many of the limestones and dolomites that were used in the study had extensive field service records it was possible to correlate many of the variables with service life. The results of this study have indicated that thermogravimetric analysis can play an important role in categorizing carbonate aggregates. In fact, with modern automated thermal analysis systems it should be possible to utilize such methods on a quality control basis. Strong correlations were found between several of the variables that were monitored in this study. In fact, several of the variables exhibited significant correlations to concrete service life. When the full data set was utilized (n = 18), the significant correlations to service life can be summarized as follows ( a = 5% level): • Correlation coefficient, r, = -0.73 for premature TG loss versus service life. • Correlation coefficient, r, = 0.74 for relative crystallite size versus service life. • Correlation coefficient, r, = 0.53 for ASTM C666 durability factor versus service life. • Correlation coefficient, r, = -0.52 for acid-insoluble residue versus service life. Separation of the carbonate aggregates into their mineralogical categories (i.e., calcites and dolomites) tended to increase the correlation coefficients for some specific variables (r sometimes approached 0.90); however, the reliability of such correlations was questionable because of the small number of samples that were present in this study.

Demonstration and Field Evaluation of Alternative Portland Cement Concrete Pavement Reinforcement Materials, HR-1069, 2003

Transverse joints are placed in portland cement concrete pavements to control the development of random cracking due to stresses induced by moisture and thermal gradients and restrained slab movement. These joints are strengthened through the use of load transfer devices, typically dowel bars, designed to transfer load across the joint from one pavement slab to the next. Epoxy coated steel bars are the materials of choice at the present time, but have experienced some difficulties with resistance to corrosion from deicing salts. The research project investigated the use of alternative materials, dowel size and spacing to determine the benefits and limitations of each material. In this project two types of fiber composite materials, stainless steel solid dowels and epoxy coated dowels were tested for five years in side by side installation in a portion of U.S. 65 near Des Moines, Iowa, between 1997 and 2002. The work was directed at analyzing the load transfer characteristics of 8-in. vs. 12-in. spacing of the dowels and the alternative dowel materials, fiber composite (1.5- and 1.88-in. diameter) and stainless steel (1.5-in. diameter), compared to typical 1.5-in. diameter epoxy-coated steel dowels placed on 12-in. spacing. Data were collected biannually within each series of joints and variables in terms of load transfer in each lane (outer wheel path), visual distress, joint openings, and faulting in each wheel path. After five years of performance the following observations were made from the data collected. Each of the dowel materials is performing equally in terms of load transfer, joint movement and faulting. Stainless steel dowels are providing load transfer performance equal to or greater than epoxy-coated steel dowels at the end of five years. Fiber reinforced polymer (FRP) dowels of the sizes and materials tested should be spaced no greater than 8 in. apart to achieve comparable performance to epoxy coated dowels. No evidence of deterioration due to road salts was identified on any of the products tested. The relatively high cost of stainless steel solid and FRP dowels was a limitation at the time of this study conclusion. Work is continuing with the subject materials in laboratory studies to determine the proper shape, spacing, chemical composition and testing specification to make the FRP and stainless (clad or solid) dowels a viable alternative joint load transfer material for long lasting portland cement concrete pavements.

Air Content and Permeability of PCC Pavements: 1909 to 2006, MLR-05-02, 2007

Portland cement concrete pavements have given excellent service history for Iowa. Many of these pavements placed during the 1920’s and 1930’s are still in service today. Many factors go in to achieve a long term durable concrete pavement. Probably the most important is the durability of the aggregate. Until the 1930’s, pit run gravel was the most predominant aggregate used. Many of these gravels provided long term performance and their durability is dependent upon the carbonate fraction of the gravel. Later, limestone (calcium carbonate) and dolomite (calcium, magnesium carbonate) sources were mined across Iowa. The durability of these carbonate aggregates is largely dependent upon the pore system which can cause freeze thaw problems known as D-cracking, which was a problem with some sources during the 1960’s. Also, some of these carbonate aggregates are also susceptible to deterioration from deicing salts. Geologists have identified the major components that affect the durability of these carbonate aggregates and sources are tested to ensure long term performance in Portland cement concrete. Air entrainment was originally put in concrete to improve scaling resistance. It is well known that air entrainment is required to provide freeze thaw protection in concrete pavements today. In Iowa, air entrainment was not introduced in concrete pavements until 1952. This research investigates properties that made older concrete pavements durable without air entrainment.

Landmark detection for fusion of fundus and MRI toward a patient-specific multimodal eye model.

Ophthalmologists typically acquire different image modalities to diagnose eye pathologies. They comprise, e.g., Fundus photography, optical coherence tomography, computed tomography, and magnetic resonance imaging (MRI). Yet, these images are often complementary and do express the same pathologies in a different way. Some pathologies are only visible in a particular modality. Thus, it is beneficial for the ophthalmologist to have these modalities fused into a single patient-specific model. The goal of this paper is a fusion of Fundus photography with segmented MRI volumes. This adds information to MRI that was not visible before like vessels and the macula. This paper contributions include automatic detection of the optic disc, the fovea, the optic axis, and an automatic segmentation of the vitreous humor of the eye.

Post-traumatic overload or acute syndrome of the os trigonum: a possible cause of posterior ankle impingement.

The purpose of this paper is to discuss the post-traumatic overload syndrome of the os trigonum as a possible cause of posterior ankle impingement and hindfoot pain. We have reviewed 19 athletes who were referred to our foot unit between 1995 and 2001 because of posterior ankle pain, and in whom a post-traumatic overload syndrome of os trigonum was diagnosed. All these patients were followed up over a period of 2 years. In 11 cases a chronic repetitive movements in forced plantar flexion was found. In the other eight cases the pain appeared to persist after a standard treatment of an ankle sprain in inversion plantar flexion. The diagnosis was based on clinical history, physical examination and X-rays that revealed a non-fused os trigonum. The confirmation of diagnosis was carried-out injecting local anaesthetic under fluoroscopic control. In all cases a corticosteroid injection as first line treatment was performed. In 6 cases a second injection was necessary to alleviate pain because incomplete recovery with the first injection. Three cases (16%) were recalcitrant to this treatment and in these three cases a surgical excision of the os trigonum was carried out. Our conclusion is that after some chronic athletic activity or an acute ankle sprain the os trigonum, if present, may undergo mechanical overload, remain undisrupted and become painful. Treatment by corticosteroid injection often resolves the problem.

Application of 1-methylcyclopropene, calcium chloride and calcium amino acid chelate on fresh-cut cantaloupe muskmelon

The objective of this work was to determine the effects of postharvest application of 1-methylcyclopropene (1-MCP) and two calcium salts, applied individually or combined, on firmness and visual quality of fresh-cut muskmelon stored in air, for 18 days. Two sets of fruits, one of them exposed to 1-MCP at 300 nL L-1, were cut into cubes, dipped in deionized water, or in 1% Ca solutions as CaCl2, or in calcium amino acid chelate (Ca-chelate), placed in clamshell containers, and stored in air at 5±1ºC and 90±5% RH, for 18 days. The assay was conducted using an entirely randomized design, with three replications, in a split plot array. Evaluation of visual appearance, color, flesh firmness, total soluble solids, titratable acidity, and pH was performed right after treatments, and every period of three days, up to eighteen days. Application of 1-MCP at 300 nL L-1, calcium chloride or Ca-chelate, or the combination 1-MCP and calcium, preserved initial freshness and reduced softening of the samples. Ca-chelate synergistically enhanced the effect of 1-MCP on firmness after nine days of storage, while calcium chloride improved firmness of the samples throughout storage. Ca-chelate may serve as an alternative for shelf life extension of cantaloupe fresh-cut muskmelon.

Historia de Vida de Andrés Díaz de Rábago S.J. (1947-1957): O cómo la Guerra Civil China cambió la estructura de la Compañía de Jesús en Asia.

Peer-reviewed

Dual inhibitors of beta-amyloid aggregation and acetylcholinesterase as multi-target anti-Alzheimer drug candidates

Notwithstanding the functional role that the aggregates of some amyloidogenic proteins can play in different organisms, protein aggregation plays a pivotal role in the pathogenesis of a large number of human diseases. One of such diseases is Alzheimer"s disease (AD), where the overproduction and aggregation of the β-amyloid peptide (Aβ) are regarded as early critical factors. Another protein that seems to occupy a prominent position within the complex pathological network of AD is the enzyme acetylcholinesterase (AChE), with classical and non-classical activities involved at the late (cholinergic deficit) and early (Aβ aggregation) phases of the disease. Dual inhibitors of Aβ aggregation and AChE are thus emerging as promising multi-target agents with potential to efficiently modify the natural course of AD. In the initial phases of the drug discovery process of such compounds, in vitro evaluation of the inhibition of Aβ aggregation is rather troublesome, as it is very sensitive to experimental assay conditions, and requires expensive synthetic Aβ peptides, which makes cost-prohibitive the screening of large compound libraries. Herein, we review recently developed multi-target anti-Alzheimer compounds that exhibit both Aβ aggregation and AChE inhibitory activities, and, in some cases also additional valuable activities such as BACE-1 inhibition or antioxidant properties. We also discuss the development of simplified in vivo methods for the rapid, simple, reliable, unexpensive, and high-throughput amenable screening of Aβ aggregation inhibitors that rely on the overexpression of Aβ42 alone or fused with reporter proteins in Escherichia coli.

Citrus asymmetric somatic hybrids produced via fusion of gamma-irradiated and iodoacetamide-treated protoplasts

The objective of this study was to produce citrus somatic asymmetric hybrids by fusing gamma-irradiated protoplasts with iodoacetamide-treated protoplasts. Protoplasts were isolated from embryogenic suspension cells of grapefruit (Citrus paradisi Macfad.) cultivars Ruby Red and Flame, sweet oranges (C. sinensis Osbeck) 'Itaboraí', 'Natal', Valencia', and 'Succari', from 'Satsuma' (C. unshiu Marcow.) and 'Changsha' mandarin (C. reticulata Blanco) and 'Murcott' tangor (C. reticulata x C. sinensis). Donor protoplasts were exposed to gamma rays and receptor protoplasts were treated with 3 mmol L-1 iodoacetamide (IOA), and then they were fused for asymmetric hybridization. Asymmetric embryos were germinated, and the resulting shoots were either grafted onto sour orange, rough lemon or 'Swingle' (C. paradisi x Poncirus trifoliata) x 'Sunki' mandarin rootstock seedlings, or rooted after dipping their bases in indol-butyric acid (IBA) solution. The products were later acclimatized to greenhouse conditions. Ploidy was analyzed by flow cytometry, and hybridity was confirmed by amplified fragment length polymorphism (AFLP) analysis of plantlet DNAsamples. The best treatment was the donor-recipient fusion combination of 80 Gy-irradiated 'Ruby Red' protoplasts with 20 min IOA-treated 'Succari' protoplasts. Tetraploid and aneuploid plants were produced. Rooting recalcitrance was solved by dipping shoots' stems in 3,000 mg L-1 IBA solution for 10 min.

Field Evaluation of Elliptical Steel Dowel Performance, 2006

Joints are always a concern in the construction and long-term performance of concrete pavements. Research has shown that we need some type of positive load transfer across transverse joints. The same research has directed pavement designers to use round dowels spaced at regular intervals across the transverse joint to distribute the vehicle loads both longitudinally and transversely across the joint. The goal is to reduce bearing stresses on the dowels and the two pavement slab edges and erosion of the underlying surface, hence improved long-term joint and pavement structure performance. Road salts cause metal corrosion in doweled joints, excessive bearing stresses hollow dowel ends, and construction processes are associated with cracking pavement at the end of dowels. Dowels are also a cost factor in the pavement costs when joint spacing is reduced to control curling and warping distress in pavements. Designers desire to place adequate numbers of dowels spaced at the proper locations to handle the anticipated loads and bearing stresses for the design life of the pavement. This interim report is the second of three reports on the evaluation of elliptical steel dowels. This report consists of an update on the testing and performance of the various shapes and sizes of dowels. It also documents the results of the first series of performance surveys and draws interim conclusions about the performance of various bar shapes, sizes, spacings, and basket configurations. In addition to the study of elliptical steel dowel performance, fiber reinforced polymers (FRP) are also tested as elliptical dowel material (in contrast to steel) on a section of the highway construction north of the elliptical steel test sections.

Fusion of protoplasts with irradiated microprotoplasts as a tool for radiation hybrid panel in citrus

The objective of this work was to combine asymmetric somatic hybridization (donor-recipient fusion or gamma fusion) to microprotoplast-mediated chromosome transfer, as a tool to be used for chromosome mapping in Citrus. Swinglea glutinosa microprotoplasts were irradiated either with 50, 70, 100 or 200 gamma rays and fused to cv. Ruby Red grapefruit or Murcott tangor protoplasts. Cell colonies were successfully formed and AFLP analyses confirmed presence of S. glutinosa in both 'Murcott' tangor and 'Ruby Red' grapefruit genomes.

Elastic properties and secondary structure formation of single-stranded DNA at monovalent and divalent salt conditions

Single-stranded DNA (ssDNA) plays a major role in several biological processes. It is therefore of fundamental interest to understand how the elastic response and the formation of secondary structures are modulated by the interplay between base pairing and electrostatic interactions. Here we measure force-extension curves (FECs) of ssDNA molecules in optical tweezers set up over two orders of magnitude of monovalent and divalent salt conditions, and obtain its elastic parameters by fitting the FECs to semiflexible models of polymers. For both monovalent and divalent salts, we find that the electrostatic contribution to the persistence length is proportional to the Debye screening length, varying as the inverse of the square root of cation concentration. The intrinsic persistence length is equal to 0.7 nm for both types of salts, and the effectivity of divalent cations in screening electrostatic interactions appears to be 100-fold as compared with monovalent salt, in line with what has been recently reported for single-stranded RNA. Finally, we propose an analysis of the FECs using a model that accounts for the effective thickness of the filament at low salt condition and a simple phenomenological description that quantifies the formation of non-specific secondary structure at low forces.

Nuclear translocation and DNA recognition signals colocalized within the bZIP domain of cyclic adenosine 3',5'-monophosphate response element-binding protein CREB.

CREB is a cAMP-responsive nuclear DNA-binding protein that binds to cAMP response elements and stimulates gene transcription upon activation of the cAMP signalling pathway. The protein consists of an amino-terminal transcriptional transactivation domain and a carboxyl-terminal DNA-binding domain (bZIP domain) comprised of a basic region and a leucine zipper involved in DNA recognition and dimerization, respectively. Recently, we discovered a testis-specific transcript of CREB that contains an alternatively spliced exon encoding multiple stop codons. CREB encoded by this transcript is a truncated protein lacking the bZIP domain. We postulated that the antigen detected by CREB antiserum in the cytoplasm of germinal cells is the truncated CREB that must also lack its nuclear translocation signal (NTS). To test this hypothesis we prepared multiple expression plasmids encoding carboxyl-terminal deletions of CREB and transiently expressed them in COS-1 cells. By Western immunoblot analysis as well as immunocytochemistry of transfected cells, we show that CREB proteins truncated to amino acid 286 or shorter are sequestered in the cytoplasm, whereas a CREB of 295 amino acids is translocated into the nucleus. Chimeric CREBs containing a heterologous NTS fused to the first 248 or 261 amino acids of CREB are able to drive the translocation of the protein into the nucleus. Thus, the nine amino acids in the basic region involved in DNA recognition between positions 287 and 295 (RRKKKEYVK) of CREB contain the NTS. Further, mutation of the lysine at position 290 in CREB to an asparagine diminishes nuclear translocation of the protein.(ABSTRACT TRUNCATED AT 250 WORDS)