Temperature profile in a reverse flow reactor for catalytic partial oxidation of methane by fast IR imaging

Catalytic partial oxidation of methane with air was investigated in a reverse flow reactor with commercial Rh/A1(2)O(3) catalyst in pellets. Temperature profile of the catalyst bed was measured by fast IR thermography and product composition was measured with a continuous gas analyzer. The effect of internal heat recovery on reactor performance and catalyst thermal stress is presented and compared with steady state operation. Feed direction switching time, total flow rate, and methane to oxygen ratio were investigated as process operating parameters. Data of catalyst bed temperature evolution during the flow cycle are presented and discussed. Comparison of dynamic heat integration with external feed preheating in terms of product composition and catalyst temperature profile is also presented. (C) 2008 American Institute of Chemical Engineers

First beam test of Laser Engineered Surface Structures (LESS) at cryogenic temperature in CERN SPS accelerator

Electron cloud mitigation is an essential requirement for accelerators of positive particles with high intensity beams to guarantee beam stability and limited heat load in cryogenic systems. Laser Engineered Surface Structures (LESS) are being considered, within the High Luminosity upgrade of the LHC collider at CERN (HL-LHC), as an option to reduce the Secondary Electron Yield (SEY) of the surfaces facing the beam, thus suppressing the elec-tron cloud phenomenon. As part of this study, a 2.2 m long Beam Screen (BS) with LESS has been tested at cryogenic temperature in the COLD bore EXperiment (COLDEX) facility in the SPS accelerator at CERN. In this paper, we describe the manufacturing procedure of the beam screen, the employed laser treatment technique and discuss our first observations in COLDEX confirming electron cloud suppression.Electron cloud mitigation is an essential requirement for accelerators of positive particles with high intensity beams to guarantee beam stability and limited heat load in cryogenic systems. Laser Engineered Surface Structures (LESS) are being considered, within the High Luminosity upgrade of the LHC collider at CERN (HL-LHC), as an option to reduce the Secondary Electron Yield (SEY) of the surfaces facing the beam, thus suppressing the electron cloud phenomenon. As part of this study, a 2.2 m long Beam Screen (BS) with LESS has been tested at cryogenic temperature in the COLD bore EXperiment (COLDEX) facility in the SPS accelerator at CERN. In this paper, we describe the manufacturing procedure of the beam screen, the employed laser treatment technique and discuss our first observations in COLDEX confirming electron cloud suppression

Structures performance, benefit, cost-study

New technology concepts and structural analysis development needs which could lead to improved life cycle cost for future high-bypass turbofans were studied. The NASA-GE energy efficient engine technology is used as a base to assess the concept benefits. Recommended programs are identified for attaining these generic structural and other beneficial technologies

Anosognosia in Early- and Late-Onset Dementia and Its Association With Neuropsychiatric Symptoms

Background: The symptom anosognosia or unawareness of disease in dementia has mainly been studied in patients with late-onset dementia (LOD, ≥65 years), whereas little is known on whether it is also present in patients with early-onset dementia (EOD, <65 years). We aimed at investigating differences in anosognosia between LOD and EOD, by also studying its association with different clinical variants of EOD and the presence of neuropsychiatric symptoms. Methods: A total of 148 patients, 91 EOD and 57 LOD, were recruited and underwent extended clinical assessment and caregiver interview that included questionnaires aimed at measuring anosognosia and neuropsychiatric symptoms. Differences in anosognosia between EOD and LOD and between subgroups with different clinical variants were investigated, as well as correlation between anosognosia and neuropsychiatric symptoms. A regression analysis was applied to explore the association between anosognosia and development of neuropsychiatric symptoms during disease progression. Results: Median levels of anosognosia were not significantly different between EOD and LOD. Anosognosia increased overtime with disease progression and was higher in frontotemporal dementia patients or, more precisely, in frontotemporal dementia and Alzheimer's disease variants associated with involvement of the frontal lobes. Higher levels of early anosognosia were associated with higher frequency and severity of subsequent neuropsychiatric symptoms, in particular apathy, later in the course of the disease. Conclusion: Anosognosia is a frequent symptom of EOD, occurring in 94.5% of all-cause EOD, and it is associated with higher risk of developing neuropsychiatric symptoms during disease progression. Recognising anosognosia may be helpful for clinicians and families to reduce diagnostic delay and improve disease managment

Tecnología ósea en la Depresión del Río Salado (provincia de Buenos Aires)

Hunter-gatherer-fishers inhabited the wetlands of the Río Salado Depression (Argentine Pampas) during the Late Holocene (ca. 2400 to 400 years BP); they manufactured pottery and developed different strategies of acquisition and manufacture of bones and teeth for use as tools. The economy of these societies was based mainly on exploiting small-sized species, such as coypu (a rodent), fishes, as well as continental and aquatic birds. Two species of deer were complementary resources. Twenty-five bones from the sites LG1 (n= 4) and LG5 (n= 21) that show indications of human manipulation were subjected to a techno-morphological analysis. The following parameters were considered: material, type of fracture, dimensions and presence/absence of marks; the effects of taphonomic agents and processes on bone surfaces are evaluated as well. Human modification on the bones of several taxa were identified: Aves (n= 4), Rallidae (n= 1), Mammalia (n= 2), Cervidae (n=4), Ozotoceros bezoarticus (n=8), Blastoceros dichotomus (n= 1), Rodentia (n= 1), Rodentia cf. Caviinae (n= 3) and Myocastor coypus (n= 1). On this basis, we characterized the Morphological Groups as, tubes, bevelled tools, points (channelled, semi-channeled, blunt-ended), and those tools not allocated to these groups, were designated as Undetermined. The potential function of these tools is discussed, we propose that bone technology was part of the integral use of faunal resources in the area.En el humedal de la Depresión del Río Salado –habitado durante el Holoceno tardío (entre 2400 y 400 años AP) por grupos de expertos alfareros– los recursos faunísticos más explotados fueron especies de porte menor como coipo, peces, aves terrestres y acuáticas. Los cérvidos fueron recursos complementarios. Estos grupos desarrollaron estrategias de aprovisionamiento y manufactura de huesos, además de incisivos de coipo, para utilizar como instrumentos. Se analizaron tecno-morfológicamente 25 piezas óseas provenientes de los sitios LG1 (n= 4) y LG5 (n= 21) con evidencias de formatización antrópica. Se tomaron los siguientes parámetros: elemento, tipo de fractura, dimensiones y presencia/ausencia de huellas; asimismo se registró la incidencia de agentes y procesos tafonómicos sobre los elementos. Se identificaron varios taxa: Aves (= 4), Rallidae (n= 1), Mammalia (n= 2), Cervidae (n= 4), Ozotoceros bezoarticus (n= 8), Blastoceros dichotomus (n=1), Rodentia (n= 1), Rodentia cf. Caviinae (n= 3) y Myocastor coypus (n= 1). Se definieron los Grupos Morfológicos: tubos, biseles, puntas (acanalada, semiacanalada, roma) y aquellos que no pudieron asignarse a los ya definidos, se indicaron como indeterminados. Se discuten posibles funciones y se propone que esta tecnología ósea es parte del uso integral de los recursos faunísticos del área

Age-specific prevalence of the different clinical presentations of AD and FTD in young-onset dementia

Background Studies have shown that the prevalence of all-variants Alzheimer's disease (AD) and frontotemporal dementia (FTD) both increase with age, even before the age of 65. However, it is not known whether their different clinical presentations all increase in prevalence with age in the same way.Methods We studied the prevalence of the different clinical presentations of young-onset AD and FTD by 5-year age groups in a population-based study identifying all dementia patients with a diagnosis of AD and FTD and symptoms onset before age 65 in the Modena province, Italy. By using regression models of cumulative occurrences, we also estimated age-specific prevalence and compared the growth curves of the clinical presentations.Results The prevalence of all-variants AD increased with age, from 18/1,000,000 in the 40-44 age group to 1411/1,000,000 in the 60-64 age group. The prevalence of all-variants FTD also increased with age, from 18/1,000,000 to 866/1,000,000. An estimation of age-specific prevalence functions of each clinical presentation showed that atypical non-amnestic AD and aphasic FTD grew the most in early ages, followed by the behavioural variant of FTD (bvFTD). Then, around the age of 60, amnestic AD took over and its age-specific prevalence continued to increase disproportionally compared to all the other clinical variants of AD and FTD, which, instead, started to decrease in prevalence.Conclusions Amnestic AD is the clinical presentation that increases the most with advancing age, followed by bvFTD, suggesting that there is a differential vulnerability to the effect of ageing within the same neurodegenerative disease

Atrial Fibrillation and Other Cardiovascular Factors and the Risk of Dementia: An Italian Case–Control Study

: Dementia is a major neurologic syndrome characterized by severe cognitive decline, and it has a detrimental impact on overall physical health, leading to conditions such as frailty, changes in gait, and fall risk. Depending on whether symptoms occur before or after the age of 65, it can be classified as early-onset (EOD) or late-onset (LOD) dementia. The present study is aimed at investigating the role of cardiovascular factors on EOD and LOD risk in an Italian population. Using a case-control study design, EOD and LOD cases were recruited at the Modena Cognitive Neurology Centers in 2016-2019. Controls were recruited among caregivers of all the dementia cases. Information about their demographics, lifestyles, and medical history were collected through a tailored questionnaire. We used the odds ratio (OR) and 95% confidence interval (CI) to estimate the EOD and LOD risk associated with the investigated factors after adjusting for potential confounders. Of the final 146 participants, 58 were diagnosed with EOD, 34 with LOD, and 54 were controls. According to their medical history, atrial fibrillation was associated with increased disease risk (ORs 1.90; 95% CI 0.32-11.28, and 3.64; 95% CI 0.32-41.39 for EOD and LOD, respectively). Dyslipidemia and diabetes showed a positive association with EOD, while the association was negative for LOD. We could not evaluate the association between myocardial infarction and EOD, while increased risk was observed for LOD. No clear association emerged for carotid artery stenosis or valvular heart disease. In this study, despite the limited number of exposed subjects and the high imprecision of the estimates, we found positive associations between cardiovascular disease, particularly dyslipidemia, diabetes, and atrial fibrillation, and EOD

Outdoor artificial light at night and risk of early-onset dementia: A case-control study in the Modena population, Northern Italy

Background Dementia is a neurological syndrome characterized by severe cognitive impairment with functional impact on everyday life. It can be classified as young onset dementia (EOD) in case of symptom onset before 65, and late onset dementia (LOD). The purpose of this study is to assess the risk of dementia due to light pollution, and specifically outdoor artificial light at night (LAN). Methods Using a case-control design, we enrolled dementia patients newly-diagnosed in the province of Modena in the period 2017–2019 and a referent population from their caregivers. We geo-referenced the address of residence on the date of recruitment, provided it was stable for the previous five years. We assessed LAN exposure through 2015 nighttime luminance satellite images from the Visible Infrared Imaging Radiometer Suite (VIIRS). Using a logistic regression model adjusted for age, sex, and education, we calculated the risk of dementia associated with increasing LAN exposure, namely using <10 nW/cm2/sr as reference and considering ≥10-<40 nW/cm2/sr intermediate and ≥40 nW/cm2/sr high exposure, respectively We also implemented non-linear assessment using a spline regression model. Results We recruited 58 EOD cases, 34 LOD cases and 54 controls. Average LAN exposure levels overlapped for EOD cases and controls, while LOD cases showed higher levels. Compared with the lowest exposure, the risk of EOD associated with LAN was higher in the intermediate exposure (OR = 1.36, 95% CI 0.54–3.39), but not in the high exposure category (OR = 1.04, 95% CI 0.32–3.34). In contrast, the risk of LOD was positively associated with LAN exposure, with ORs of 2.58 (95% CI 0.26–25.97) and 3.50 (95% CI 0.32–38.87) in the intermediate and high exposure categories, respectively. The spline regression analysis showed substantial lack of association between LAN and EOD, while almost linear although highly imprecise association emerged for LOD. Conclusions Although the precision of the estimates was affected by the limited sample size and the study design did not allow us to exclude the presence of residual confounding, these results suggest a possible role of LAN in the etiology of dementia, particularly of its late-onset form

7.000 AÑOS DE HISTORIA EN EL FIN DEL MUNDO

Se ha propuesto que las migraciones podrían expli-car cambios culturales identificados en el registro ar-queológico de Patagonia Austral, como el desarrollo de estrategias de aprovechamiento de recursos marinos y modificaciones en las herramientas utilizadas. El análisis del genoma de individuos de origen arqueológico revela una continuidad genética durante 6.600 años y sugiere que los movimientos poblacionales no explican la apari-ción de la adaptación marina, adquirida por desarrollo local o por transmisión cultural. Sin embargo, dos even-tos de migración posteriores estarían correlacionados con cambios vinculados a tecnologías líticas. Además, se observa que ocurrieron procesos de mestizaje entre grupos vecinos hace 1.500 años

Two-Dimensional Infrared Spectroscopy of Antiparallel β-Sheet Secondary Structure

We investigate the sensitivity of femtosecond Fourier transform two-dimensional infrared spectroscopy to protein secondary structure with a study of antiparallel β-sheets. The results show that 2D IR spectroscopy is more sensitive to structural differences between proteins than traditional infrared spectroscopy, providing an observable that allows comparison to quantitative models of protein vibrational spectroscopy. 2D IR correlation spectra of the amide I region of poly-L-lysine, concanavalin A, ribonuclease A, and lysozyme show cross-peaks between the IR-active transitions that are characteristic of amide I couplings for polypeptides in antiparallel hydrogen-bonding registry. For poly-L-lysine, the 2D IR spectrum contains the eight-peak structure expected for two dominant vibrations of an extended, ordered antiparallel β-sheet. In the proteins with antiparallel β-sheets, interference effects between the diagonal and cross-peaks arising from the sheets, combined with diagonally elongated resonances from additional amide transitions, lead to a characteristic “Z”-shaped pattern for the amide I region in the 2D IR spectrum. We discuss in detail how the number of strands in the sheet, the local configurational disorder in the sheet, the delocalization of the vibrational excitation, and the angle between transition dipole moments affect the position, splitting, amplitude, and line shape of the cross-peaks and diagonal peaks.