Oscar Lopez

Bimodality is observed on the size of the heaviest released fragment for semi-peripheral heavy ion induced reactions in the intermediate energy domain. From lattice-gas calculations, this signal can sign a phase transition even if the system has not reached a complete equilibrium. It is shown from the data that it is correlated with other possible phase transition signals. The two

The influence of radial flow on nuclear multifragmentation is studied using Au+Au central collisions for incident energies between 40 and 100 MeV/A. Central collisions are selected via an impact parameter estimator defined by the transverse energy of light charged particles. At all energies, the fragment size distributions are studied using the Statistical Multifragmentation Model (SMM) in order to extract thermal

The fragmentation of quasi-projectiles from the nuclear reaction $^{40}Ca$+$^{12}C$ at 25 MeV/nucleon was used to produce excited states candidates to $\alpha$-particle condensation. The methodology relies on high granularity 4$\pi$ detection coupled to correlation function techniques. Under the assumption that the equality among the kinetic energies of the emitted $\alpha$-particles and the emission simultaneity constitutes a reliable fingerprint of $\alpha$ condensation,

The fragmentation of quasi-projectiles from the nuclear reaction $^{40}Ca$ + $^{12}C$ at 25 MeV/nucleon was used to produce excited states candidates to $\alpha$-particle condensation. The experiment was performed at LNS-Catania using the CHIMERA multidetector. Accepting the emission simultaneity and equality among the $\alpha$-particle kinetic energies as experimental criteria for deciding in favor of the condensate nature of an excited state,

... 267 13. Derwin KA Soslowsky LJ A quantitative investigation of structure-function relationships in a tendon fascicle model. J. Biomech. Eng. ... 272 35. Bouwstra JA, Gooris GS, Cheng K., Weerheim A., Bras W., Ponec M. Phase behavior of isolated skin lipids. J. Lipid. ...

... Dur-(a) (b) Fig. 3. Mean signed errors (a) and mean absolute errors (b) as a function of feature subset size selected from top 50 AVR-ranked fea-tures. ... 576 – 579. [12] Yanxi Liu, Leonid Teverovskiy, Owen Carmichael, R. Kiki-nis, M. Shenton, CS Carter, VA Stenger, S. Davis ...

In order to develop systemically-active opioid peptides, the delta-selective, opioid pentapeptide [D-Pen2,D-Pen5]-enkephalin (DPDPE) was modified by esterification and by substitution of 2',6'-dimethyltyrosine for tyrosine to yield 4. Compound 4 was on the order of 8- and 800-fold more active than DPDPE in both delta and mu opioid radioligand binding assays, respectively, in rat neural membrane suspensions. Compound 4 was considerably more potent than DPDPE at inhibiting contractions of electrically-stimulated mouse vas deferens in vitro, and this effect was very sensitive to naltrindole, a delta-selective opioid antagonist. These observations can be taken as indication that 4 exerts its effects through delta opioid receptors. This interpretation is supported by the finding that the EC50 value of 4 derived in the smooth muscle assay is very similar to that derived in NG108-15 neuroblastoma cells, a preparation devoid of mu receptors. Unlike DPDPE, 4 exhibited significant, naloxone-sensitive, antinociceptive activity when administered systemically, as measured by inhibition of phenylbenzquinone-induced stretching in mice (ED50 = 2.1 mg/kg). Compound 4 also displayed significant antinociceptive activity following systemic administration as measured by its action in mice to increase latencies for tail withdrawal from radiant heat (ED50 = 50 mg/kg). Compound 4 did not produce morphine-like discriminative stimulus effects in rats trained to discriminate 3.0 mg/kg morphine from vehicle at doses ranging from 30 to 120 mg/kg. This observation can be interpreted as indication that within this dosage range there is an absence of morphine-like subjective effects. Physical dependence, however, could be induced in mice at higher doses of 4 under a progressively-graded, 4-day dose regimen. Congeners of 4 with amide bond surrogates for the Gly-Phe amide bond (oxymethylene, trans-double bond, and bismethylene isosteres) in the cyclic core of DPDPE were prepared in an attempt to increase the antinociceptive activity of 4. While some of the congeners were active in the in vitro assays, they did not display significant antinociceptive activity following systemic administration. The preparation of all the compounds was accomplished by solution-phase methods. The mechanisms which might underlie the biological and systemic activity of 4 are discussed.

Abstract Measurement of any complex, operational system is challenging due to the continuous independent evolution of the components. Security risks introduce another dimension of dynamicity, reflected to risk management and security assurance activities. ...

This paper describes the sliding mode control design of a boost high-power-factor AC/DC pre-regulator. The proposed controller operates in the continuous conduction mode and avoids the use of an analogue multiplier and line voltage sensing. Therefore, it is an interesting solution when high efficiency and a simple control circuit are required

The Old Type II are school buildings that were built more than 50 years ago, designed with less demanding standards than the current ones, similar to those that collapsed in Cariaco during the Earthquake of 1997. The structural and architectural drawings of these constructions are not available, neither the calculations used in their design. Preliminary results of the seismic evaluation

This paper introduces a new approach to interleaving parallel power converters using a multi-input sliding-mode control scheme. The control approach is based on sliding surfaces which naturally provide interleaving between cells of a modular power supply system. Moreover, the sliding surfaces provide equal current distribution among the power converter modules and a regulated voltage in the output. The technique is

This paper presents a new switch control strategy for an electronic step-down transformer, providing variable conversion ratio and zero-current switching conditions. To implement the new control technique, a closed-loop nonlinear controller is proposed, based on the sliding mode control theory. The controller provides good transient response, absence of steady-state errors in the output voltage and robust output response with respect

A unity power factor quantum series resonant buck-boost power converter is presented. An averaged model is used to design the multi-input sliding control scheme for the power converter. The proposed control provides both robustness, with regard to external disturbances, and a good dynamic response of the output voltage

A new family of single-stage unity power factor converters is proposed. Although they operate in continuous conduction mode, a single switch is able to control the line current and the output voltage at the same time. The proposed structures are based on a three-state switch whose switching and conduction losses are similar to those of a conventional device

Abstract We present the electrical and thermal performance of ultra-thin RF LDMOS devices. Following a proprietary process, we fabricated such devices with a thickness as reduced as 40μm. This results in a reduction of the operating junction temperature, as demonstrated ...

The hippocampal formation is a brain structure integrally involved in episodic memory, spatial navigation, cognition and stress responsiveness. Structural abnormalities in hippocampal volume and shape are found in several common neuropsychiatric disorders. To identify the genetic underpinnings of hippocampal structure here we perform a genome-wide association study (GWAS) of 33,536 individuals and discover six independent loci significantly associated with hippocampal volume, four of them novel. Of the novel loci, three lie within genes (ASTN2, DPP4 and MAST4) and one is found 200 kb upstream of SHH. A hippocampal subfield analysis shows that a locus within the MSRB3 gene shows evidence of a localized effect along the dentate gyrus, subiculum, CA1 and fissure. Further, we show that genetic variants associated with decreased hippocampal volume are also associated with increased risk for…

Great heterogeneity exists in survival and the interval between onset of motor symptoms and dementia symptoms across synucleinopathies. We aimed to identify genetic and pathological markers that have the strongest association with these features of clinical heterogeneity in synucleinopathies. In this retrospective study, we examined symptom onset, and genetic and neuropathological data from a cohort of patients with Lewy body disorders with autopsy-confirmed α synucleinopathy (as of Oct 1, 2015) who were previously included in other studies from five academic institutions in five cities in the USA. We used histopathology techniques and markers to assess the burden of tau neurofibrillary tangles, neuritic plaques, α-synuclein inclusions, and other pathological changes in cortical regions. These samples were graded on an ordinal scale and genotyped for variants associated with synucleinopathies. We assessed the interval from onset of motor symptoms to onset of dementia, and overall su...

ABSTRACT We present the electrical and thermal performance of ultra-thin RF LDMOS devices. Following a proprietary process, we fabricated such devices with a thickness as reduced as 40¿m. This results in a reduction of the operating junction temperature, as demonstrated by infrared imaging experiments and three-dimensional finite-element-analysis simulations. As a result, the thermal resistance of our packaged devices reaches substantially lower values than industry standard. This allows for a higher power output and improved efficiency, as demonstrated by RF measurements.

We performed an exome-wide association analysis in 1393 late-onset Alzheimer's disease (LOAD) cases and 8141 controls from the CHARGE consortium. We found that a rare variant (P155L) in TM2D3 was enriched in Icelanders (~0.5% versus <0.05% in other European populations). In 433 LOAD cases and 3903 controls from the Icelandic AGES sub-study, P155L was associated with increased risk and earlier onset of LOAD [odds ratio (95% CI) = 7.5 (3.5-15.9), p = 6.6x10-9]. Mutation in the Drosophila TM2D3 homolog, almondex, causes a phenotype similar to loss of Notch/Presenilin signaling. Human TM2D3 is capable of rescuing these phenotypes, but this activity is abolished by P155L, establishing it as a functionally damaging allele. Our results establish a rare TM2D3 variant in association with LOAD susceptibility, and together with prior work suggests possible links to the β-amyloid cascade.

... ca encaminadas al cuidado del movi-miento corporal humano. M en C. Germán Baquero. Director de Programa de Fisioterapia de la Fundación Universitaria Manuela Beltrán, Bogotá, Colombia. Correo electrónico: gbaq@umb.edu.co Lic. Oscar López. ...

Intracranial volume reflects the maximally attained brain size during development, and remains stable with loss of tissue in late life. It is highly heritable, but the underlying genes remain largely undetermined. In a genome-wide association study of 32,438 adults, we discovered five previously unknown loci for intracranial volume and confirmed two known signals. Four of the loci were also associated with adult human stature, but these remained associated with intracranial volume after adjusting for height. We found a high genetic correlation with child head circumference (ρgenetic = 0.748), which indicates a similar genetic background and allowed us to identify four additional loci through meta-analysis (Ncombined = 37,345). Variants for intracranial volume were also related to childhood and adult cognitive function, and…

Multiphase series-connected motor drives can be supplied from a two-level voltage source inverter (VSI), which has either a prime or a composite number of legs (phases). It has been shown recently that, in the case of a prime number of inverter/machine phases, limits of the linear PWM region get extended over those valid for a particular phase number due to

As members of the Lewy Body Dementia Association Scientific Advisory Council, we aim to address some of the issues raised in the article titled "Time to Redefine PD? Introductory Statement of the MDS Task Force on the Definition of Parkinson's Disease." In particular, we suggest that the 1-year rule distinguishing Parkinson's disease dementia from dementia with Lewy bodies is worth maintaining because it serves an important purpose in clinical practice and clinical and basic science research and when helping the lay community understand the complexity of these different clinical phenotypes. Furthermore, we believe that adding an additional diagnostic label, "PD (dementia with Lewy bodies…

Non-sinusoidal back electromagnetic forces cause torque ripple in permanent magnet synchronous motors. These harmonics should be reduced by means of an appropriate current control to improve performance. Good results have been obtained with linear regulators such as repetitive controllers in synchronous reference frame (SRF) and resonant controllers in stationary frame. Repetitive controllers present drawbacks such as difficult frequency adaptation, due

To examine the association between inflammatory biomarkers and global cognitive function. Case-cohort. Ginkgo Evaluation of Memory Study. Individuals aged 75 and older free of neurological or neurodegenerative conditions recruited from 2000 to 2002 (N = 1,315). Outcome was cognitive function assessed using the modified Mini-Mental State Examination (3MSE) every 6 months for up to 7 years. Exposures were 10 biomarkers measured at baseline: interleukin-2, -6, and -10 (general systemic inflammation); pentraxin 3 (PTX3) and serum amyloid P (SAP) (vascular inflammation); plasminogen activator inhibitor-1, adiponectin, and resistin (metabolic function); receptor for advanced glycation endproduct (oxidative stress); and endothelin-1 (endothelial function). Associations between biomarkers and 3MSE scores (stratified according to mild cognitive impairment (MCI) at baseline) were analyzed using Cox regression (outcome: 3MSE decline of ≥5 points) and mixed-model regression. Bonferroni correcti...

Vitamin D deficiency has been linked with an increased risk of incident all-cause dementia and Alzheimer's disease. The aim of the current study was to explore the potential mechanisms underlying these associations by determining whether low vitamin D concentrations are associated with the development of incident cerebrovascular and neurodegenerative neuroimaging abnormalities. The population consisted of 1,658 participants aged ≥65 years from the US-based Cardiovascular Health Study who were free from prevalent cardiovascular disease, stroke and dementia at baseline in 1992-93. Serum 25-hydroxyvitamin D (25(OH)D) concentrations were determined by liquid chromatography-tandem mass spectrometry from blood samples collected at baseline. The first MRI scan was conducted between 1991-1994 and the second MRI scan was conducted between 1997-1999. Change in white matter grade, ventricular grade and presence of infarcts between MRI scan one and two were used to define neuroimaging abnor...

Conventional software processes such as the Unified Process do not include reuse techniques among their disciplines. In this article, we present an extension of the Unified Process that introduces software reuse with minimal disturbance by means of the definition of a new process for product line engineering and the adaptation of standard disciplines for specific product construction. This proposal reduces

Physical activity (PA) can be neuroprotective and reduce the risk for Alzheimer's disease (AD). In assessing physical activity, caloric expenditure is a proxy marker reflecting the sum total of multiple physical activity types conducted by an individual. To assess caloric expenditure, as a proxy marker of PA, as a predictive measure of gray matter (GM) volumes in the normal and cognitively impaired elderly persons. All subjects in this study were recruited from the Institutional Review Board approved Cardiovascular Health Study (CHS), a multisite population-based longitudinal study in persons aged 65 and older. We analyzed a sub-sample of CHS participants 876 subjects (mean age 78.3, 57.5% F, 42.5% M) who had i) energy output assessed as kilocalories (kcal) per week using the standardized Minnesota Leisure-Time Activities questionnaire, ii) cognitive assessments for clinical classification of normal cognition, mild cognitive impairment (MCI), and AD, and iii) volumetric MR imagi...

The successful prevention and treatment of coronary heart disease (CHD) and stroke has resulted in a substantial increase in longevity, with subsequent growth in the population of older people at risk for dementia. The authors evaluated the relationship of coronary and other peripheral atherosclerosis to risk of death, dementia, and CHD in the very elderly. Because the extent of vascular disease differs substantially between men and women, sex- and race-specific analyses were included, with a specific focus on women with low coronary artery calcium (CAC) Agatston scores. We evaluated the relationship between measures of subclinical cardiovascular disease (CAC, carotid intimal medial thickness, stenosis, and ankle brachial index) and risk of dementia, CHD, and total mortality in 532 participants of the Cardiovascular Health Study-Cognition Study from 1998/1999 (mean age, 80 years) to 2012/2013 (mean age, 93 years). Thirty-six percent of participants had CAC scores >400. Women and ...

Vitamin D deficiency has been linked with dementia risk, cognitive decline, and executive dysfunction. However, the association with memory remains largely unknown. To investigate whether low serum 25-hydroxyvitamin D (25(OH)D) concentrations are associated with memory decline. We used data on 1,291 participants from the US Cardiovascular Health Study (CHS) and 915 participants from the Dutch Longitudinal Aging Study Amsterdam (LASA) who were dementia-free at baseline, had valid vitamin D measurements, and follow-up memory assessments. The Benton Visual Retention Test (in the CHS) and Rey's Auditory Verbal Learning Test (in the LASA) were used to assess visual and verbal memory, respectively. In the CHS, those moderately and severely deficient in serum 25(OH)D changed -0.03 SD (95% CI: -0.06 to 0.01) and -0.10 SD (95% CI: -0.19 to -0.02) per year respectively in visual memory compared to those sufficient (p = 0.02). In the LASA, moderate and severe deficiency in serum 25(OH)D wa...