bluuebunny/crossref_metadata_2025 huggingface dataset:
Post‐fire regeneration in alpine heathland: Does fire severity matter?
Authors: CAMAC JAMES S. , WILLIAMS RICHARD J. , WAHREN CARL‐HENRIK , MORRIS WILLIAM K. , MORGAN JOHN W.
Published: April 2012

Fire severity is thought to be an important determinant of landscape patterns of post‐fire regeneration, yet there have been few studies of the effects of variation in fire severity at landscape scales on floristic diversity and composition, and none within alpine vegetation. Understanding how fire severity affects alpine vegetation is important because fire is relatively infrequent in alpine environments. Globally, alpine ecosystems are at risk from climate change, which, in addition to warming, is likely to increase the severity and frequency of fire in south‐eastern Australia. Here we examine the effects of variation in fire severity on plant diversity and vegetation composition, 5 years after the widespread fires of 2003. We used floristic data from two wide‐spread vegetation types on the Bogong High Plains: open heathland and closed heathland. Three alternative models were tested relating variation in plant community attributes (e.g. diversity, ground cover of dominant species, amount of bare ground) to variation in fire severity. The models were (i) ‘linear’, attributes vary linearly with fire severity; (ii) ‘intermediate disturbance’, attributes are highest at intermediate fire severity and lowest at both low‐ and high‐severity; and (iii) ‘null’, attributes are unaffected by fire severity. In both heathlands, there were few differences in floristic diversity, cover of dominant species and community composition, across the strong fire severity gradient. The null model was most supported in the vast majority of cases, with only limited support for either the linear and intermediate disturbance models. Our data indicate that in both heathlands, vegetation attributes in burnt vegetation were converging towards that of the unburnt state. We conclude that fire severity had little impact on post‐fire regeneration, and that both closed and open alpine heathlands are resilient to variation in fire severity during landscape scale fires.
Comparison of recommendations for radiotherapy from two contemporaneous thoracic multidisciplinary meeting formats: co‐located and video conference
Authors: Stevens G. , Loh J. , Kolbe J. , Stevens W. , Elder C.
Published: April 2012

Background

Thoracic multidisciplinary meetings (TMDM) are a key component of lung cancer patient management. The optimal design, organisation and function of TMDM are uncertain, and different models may serve different purposes. In the Auckland/Northland region, there are two contemporaneous weekly TMDM using different formats; one is a co‐located TMDM (C‐TMDM), and the other is a video conference TMDM (V‐TMDM) connecting different locations.

Aims

To determine whether the rates of referral for radiotherapy (RT) and concordance between recommendations for RT and actual treatment received differed between the two TMDM formats.

Method

A retrospective review of demographical and clinical data for cases referred for RT from both TMDM between January–June 2009 and the actual RT delivered.

Results

Seventy‐nine and 31 lung cancers were referred for RT from the co‐located TMDM and the video conference TMDM respectively. While there were significant differences in demographics related to areas of domicile, there were no significant differences between the TMDM in (i) the proportion of cases referred for RT that received RT, (ii) the intent of treatment recommended by the TMDM and the intent of RT delivered, or (iii) transit times to commencement of RT between cases referred from the different TMDM.

Conclusion

The similar results from the different formats of TMDM indicate that cases discussed with the use of e‐health technologies are not disadvantaged with respect to recommended therapy nor in the appropriateness of decisions of the TMDM. Use of such technology may reduce the existing disparities in health outcomes between urban and rural patients.
Mini Nutritional Assessment and functional capacity in community‐dwelling elderly in Rural Luozi, Democratic Republic of Congo
Authors: Andre Muzembo Basilua , Dumavibhat Narongpon , Ngatu N'landu Roger , Eitoku Masamitsu , Hirota Ryoji , Suganuma Narufumi
Published: April 2012

Aim:  Good nutrition is beneficial both for the health and the functional capacity of the elderly. However, malnutrition is a serious health problem among the elderly, particularly the elderly living in rural areas in many developing countries. The aim of the present study was to carry out a cross‐sectional study of the elderly in the city of Luozi, Democratic Republic of Congo, through the use of the long and the short forms of the Mini Nutritional Assessment (MNA) scale.

Methods:  We carried out a cross‐sectional study in the city of Luozi, a city facing serious socioeconomic problems as a result of wartime conditions in the country. The study included 370 volunteer community‐dwelling elderly people aged 65–88 years, both male and female. Investigations took into account the MNA, the activities of daily living, and the instrumental activities of daily living, falls, current diseases and lifestyle.

Results:  Approximately 57.8% of the participants were at risk of malnutrition, whereas 28.4% were malnourished according to the MNA scale. MNA scores were significantly lower (Student's t‐test, P = 0.03) in those with a fall history (MNA score 18.3 ± 4.0) compared with those who did not (MNA score, 21.0 ± 2.7). All the participants with malnutrition suffered from at least one chronic disease. The percentage of participants with dependency was significantly higher in the malnourished participants (87.6%) than in well‐nourished participants (50.9%).

Conclusion:  These findings provide information that malnutrition is a serious health concern among elderly people in the city of Luozi, and shows the need for adequate nutrition and social programs for the elderly. Geriatr Gerontol Int 2013; 13: 35–42.
Patterns of elevational beta diversity in micro‐ and macroorganisms
Authors: Wang Jianjun , Soininen Janne , Zhang Yong , Wang Beixin , Yang Xiangdong , Shen Ji
Published: April 2012

Aim  While ecologists have long been interested in diversity in mountain regions, elevational patterns in beta diversity are still rarely studied across different life forms ranging from micro‐ to macroorganisms. Also, it is not known whether the patterns in turnover among organism groups are affected by the degree to which the environment is modified by human activities.

Location  Laojun Mountain, Yunnan Province, China.

Methods  The beta diversity patterns of benthic microorganisms (i.e. diatoms and bacteria) and macroorganisms (i.e. macroinvertebrates) in a stony stream were simultaneously investigated between elevations of 1820 and 4050 m. Data were analysed by using a distance‐based approach and variation partitioning based on canonical redundancy analysis.

Results  Analyses of community dissimilarities between adjacent sampling sites showed comparable small‐scale beta diversity along the elevational gradient for the organism groups. However, bacteria clearly showed the lowest elevational turnover when analyses were conducted simultaneously for all pairwise sites. Variation partitioning indicated that species turnover was mostly related to environmental heterogeneity and spatial gradients including horizontal distance and elevation, while purely human impacts were shown to be less important.

Main conclusions  The elevational beta diversity at large scales was lower for bacteria than for eukaryotic microorganisms or macroorganisms, perhaps indicative of high dispersal ability and good adaptability of bacteria to harsh environmental conditions. However, the small‐scale beta diversity did not differ among the groups. Elevation was the major driver for the turnover of eukaryotic organisms, while the turnover of bacteria was correlated more with environmental variation.
Loss of small glaciers will diminish beta diversity in Pyrenean streams at two levels of biological organization
Authors: Finn Debra S. , Khamis Kieran , Milner Alexander M.
Published: April 2012

Aim  Small (< 1 km2) alpine glaciers are likely to disappear in this century, resulting in decreased regional habitat heterogeneity in associated streams. Both heterogeneity within and spatial isolation among glacier‐influenced streams can enhance beta diversity of stream‐dwelling organisms. We measured beta at both community and population‐genetic levels within and among streams currently influenced by small Pyrenean glaciers. We aimed to evaluate whether patterns are analogous between the two levels, to apply various approaches for characterizing beta, and to infer the outcome of future glacier loss on regional biodiversity.

Location  Four glacier‐fed basins in the Parc National des Pyrénées, France.

Methods  We classified each of 18 stream reaches across the basins into either high‐, mid‐ or low‐‘glaciality’ (glacial influence) groups according to four physicochemical characteristics. At each reach, we collected macroinvertebrate communities and evaluated mitochondrial DNA haplotypes for 11–13 individuals of Baetis alpinus Pictet. Using taxa/haplotypes as basic units, we evaluated community and population‐genetic beta diversity simultaneously. We measured beta diversity in three major ways: as multivariate (Sørensen's dissimilarity, Jost D) and ‘classical’ (gamma/alpha) variation to compare among glaciality groups, and as turnover along the glaciality gradient within each basin.

Results  For most approaches at both organizational levels, beta was greatest among high‐glaciality reaches, absolute values of variation of beta in high‐glaciality streams were strikingly similar between levels, and the steepest turnover within basins occurred between high‐ and mid‐glaciality reaches. Therefore, high‐glaciality reaches contained assemblages and populations that were unique both within that stream type (among basins) and compared with other stream types within basins.

Main conclusions  Parallel beta diversity patterns at population‐genetic and community levels suggested that environmental drivers influence these levels analogously. Extreme conditions (e.g. low temperature, high instability, isolation) in high‐glaciality streams probably enhance beta at both levels. Stream beta diversity is likely to decrease substantially with continued glacial reduction in this system.
Separating the Fish From the Sharks: A Longitudinal Study of Preschool Response Inhibition
Authors: Wiebe Sandra A. , Sheffield Tiffany D. , Espy Kimberly Andrews
Published: April 2012

The development of response inhibition was investigated using a computerized go/no‐go task, in a lagged sequential design where 376 preschool children were assessed repeatedly between 3.0 and 5.25 years of age. Growth curve modeling was used to examine change in performance and predictors of individual differences. The most pronounced change was observed between 3 and 3.75 years. Better working memory and general cognitive ability were related to more accurate performance at all ages, but relations with speed changed with age, where better cognitive skills were initially related to slower responding, but faster responding at later ages. Boys responded more quickly and were more accurate on go trials, whereas girls were better able to withhold responding on no‐go trials.
Using Saliency Maps to Separate Competing Processes in Infant Visual Cognition
Authors: Althaus Nadja , Mareschal Denis
Published: April 2012

This article presents an eye‐tracking study using a novel combination of visual saliency maps and “area‐of‐interest” analyses to explore online feature extraction during category learning in infants. Category learning in 12‐month‐olds (N = 22) involved a transition from looking at high‐saliency image regions to looking at more informative, highly variable object parts. In contrast, 4‐month‐olds (N = 27) exhibited a different pattern displaying a similar decreasing impact of saliency accompanied by a steady focus on the object’s center, indicating that targeted feature extraction during category learning develops across the 1st year of life. These results illustrate how the effects of lower and higher level processes may be disentangled using a combined saliency map and area‐of‐interest analysis.
Anotherpolitical ecology of civil society reflexiveness against urban industrial risks for environmental justice: The case of the Bisasar landfill, Durban, South Africa
Authors: Leonard Llewellyn
Published: April 2012

The concerns of political ecology since its beginnings as a field have been predominantly set in rural areas with limited focus on urban industrial risks. Further, debates on the global South (often from Anglo‐American perspectives) have not fully appreciated the divergent and differentiated perceptions of urban risks and, therefore, everyday forms of resistance within civil society. Instead, work has mainly focused on civil society power relations against the state and industry that are driven by coherent populist political agendas. Against this setting, this paper's contribution aims to better contextualize ‘other’ third world localities in political ecology through a case study of urban industrial risks in the upper/middle income (as opposed to rural, low/lower middle income) country, South Africa. In doing so, the paper sheds light on the derelict aspect of civil society contestation, especially along class and ethnic lines, over urban landfill infrastructure as a livelihood resource or a health hazard. The paper draws upon frameworks of self‐reflexivity and reflexive localism as complementary to the mainstream political ecology to illuminate differentiated civil society reflexiveness and therefore, aims to advance the discussion of other political ecologies. The case study of the largest formal landfill site in Africa, the Bisasar landfill situated in Durban, highlights differences underlying power relations and constraints within civil society (in leadership, social networking, resources and mistrust) that have implications for mainstream political ecology notions of civil society coherence.
Competing rationalities in water conflict: Mining and the indigenous community in Chiu Chiu, El Loa Province, northern Chile
Authors: Camacho Francisco Molina
Published: April 2012

Conflict over water is a significant phenomenon in many parts of the world where globally linked neoliberal economic activities encroach on the lands of indigenous peoples. This case study from Chile examines how water scarcity affecting indigenous agricultural communities in the Chilean Altiplano has been exacerbated by legally sanctioned mining‐related practices. Notably, the legal framing of the 1981 Water Code promotes private ownership of water rights and enhanced mining activity usually at the expense of the ancestral territorial rights of indigenous communities. In the case of the Atacameño community of Chiu Chiu, a serious decrease in subsistence and agriculture production has been suffered as a consequence of reduced flow in the Loa River, resulting from the water intensive needs and extraction practices of the nearby Chuquicamata mine owned by Codelco, the National Copper Corporation of Chile. Via an analysis of the political ecology of competing rationalities this paper explores how an economic rationality based on utilitarian and reductionist thinking manifested by Codelco has taken precedence locally over a socionatural rationality grounded in holistic thinking and sustainability concerns as articulated by the Chiu Chiu community.
Bringing the other into political ecology: Reflecting on preoccupations in a research field
Authors: Kim Soyeun , Ojo Godwin Uyi , Zaidi Rukhe Zehra , Bryant Raymond L.
Published: April 2012

For all its vitality political ecology often appears to be a project in which work by Anglo‐Americans in particular, if it is not privileged, certainly predominates. This trend reflects wider language and intellectual tendencies in human geography and the social sciences that distort the development of the field by downplaying or obscuring the contributions of many non‐Anglo‐Americans and by naturalizing Anglo‐American assumptions at the heart of research. The latter in turn determine what constitutes ‘good’ work – even as there is no single definition of political ecology. Arguing against this tendency, this paper draws on postcolonial thinking to emphasize the need to reassess and reorient the field as ‘other’ political ecologies are feasible and desirable.
Entering the field: Examining the relevance of political ecology to the agrarian struggle of Anjuman Muzareen Punjab in Pakistan
Authors: Zaidi Rukhe Zehra
Published: April 2012

The widening empirical and theoretical scope of political ecology has been accompanied by discussions on the coherence and content of the field. While these evaluations necessarily focus on what is included in the conceptual boundaries of political ecology, little is said about what is left out. This paper considers the struggle for land rights by Anjuman Muzareen Punjab, a movement of tenant farmers in Pakistan, to illustrate how changing research priorities, difficulties in crossing theoretical and conceptual boundaries, and geopolitics and research access can hinder the visibility of particular forms of socioenvironmental events in mainstream political ecology scholarship.
Social Goals and Youth Aggression: Meta‐analysis of Prosocial and Antisocial Goals
Authors: Samson Jennifer E. , Ojanen Tiina , Hollo Alexandra
Published: April 2012

To advance research evaluating the relationship between social information processing (Crick & Dodge) and youth aggression, this meta‐analytic study examined associations between social goals and aggression in children in 21 separate research reports. Eligible studies provided descriptive or preintervention measurement of children's aggression and social goals, and were reported in English by March 1, 2010. Findings from two random‐effects meta‐analyses utilizing clustered data analysis techniques (i.e., effect sizes nested within samples) supported an expected (1) negative association between prosocial goals and aggression, and (2) positive association between antisocial goals and aggression. Little heterogeneity in these associations was observed across studies, and no moderating variables were revealed. The findings extend existing meta‐analytic research on social information processing and aggression to include social goals as meaningful correlates of youth aggression.
Episodes of Large Capital Inflows, Banking and Currency Crises, and Sudden Stops
Authors: Furceri Davide , Guichard Stéphanie , Rusticelli Elena
Published: April 2012

This paper empirically investigates the relationship between surges in capital inflows and the probability of subsequent banking, currency and balance‐of‐payment crises. Using a panel of developed and emerging economies from 1970 to 2007, it shows that a large capital inflow episode increases substantially the probability of having a banking or a currency crisis in the two following years. The effect is especially large for the case of balance‐of‐payment crises. The paper also finds that the effect of large capital inflows is different depending on the type of flows characterizing the episode. In particular, large capital inflows that are debt driven significantly increase the probability of banking, currency and balance‐of‐payment crises, whereas inflows that are driven by equity portfolio investment or foreign direct investment have a negligible effect.
Spillovers of Domestic Shocks: Will They Counteract the ‘Great Moderation’?
Authors: Carare Alina , Mody Ashoka
Published: April 2012

The protracted decline in output volatility – the Great Moderation – began to reach its limits by the mid‐1990s, and volatility even showed a mild rise in some countries. Domestic shocks did not typically rise but we find that they did spread more rapidly across borders. One reason for the faster transmission of domestic shocks was the increased fragmentation of production across multiple global locations that increasingly included the more volatile emerging markets. Although this development was generally benign, it had latent implications for triggering spikes in volatility since domestic stresses could rapidly spillover across borders. The cascading effects of such spillovers were vividly demonstrated by the trade collapse during the Great Recession of 2008–09.
Instrument versus Target Rules As Specifications of Optimal Monetary Policy
Authors: Froyen Richard T. , Guender Alfred V.
Published: April 2012

Central banks frequently apply target rules or instrument rules in the conduct of monetary policy. For a central bank with multiple target variables such as the Federal Reserve's ‘dual mandate’, a target rule expresses the desired values for each target and the relative weight given to each. The so‐called Taylor rule, in which the central bank chooses how to respond to the output gap and inflation, is an example of an instrument rule. This paper sets out the parameters of ‘optimal’ target and instrument rules and analyses their relative merits. In contrast to Svensson and Woodford, we find that target rules offer no clear advantages over optimal instrument rules. From a policy perspective, this suggests that the case for target rules has been overstated. The use of optimal instrument rules accords with current Federal Reserve practice whereby the federal funds rate responds to optimal forecasts – those using all available information.
Direct Marketing in Oligopoly
Authors: Mizuno Tomomichi
Published: April 2012

We consider a game in which symmetric manufacturers decide whether to set up sites (e.g., web sites) where consumers can buy their products directly. Following this decision, the manufacturers choose quantities to sell to the retailers, and then the manufacturers with direct‐sales sites and retailers choose quantities to sell to the consumers. We show that since an increase in the number of retailers may drive the direct‐selling manufacturers from the retail market, it may raise the retailers’ profit and reduce social welfare. Finally, we discuss two cases: an oligopolistic wholesale market and a market with price competition and differentiated products.
PZT‐Based Piezoelectric MEMS Technology
Authors: Smith Gabriel L. , Pulskamp Jeffrey S. , Sanchez Luz M. , Potrepka Daniel M. , Proie Robert M. , Ivanov Tony G. , Rudy Ryan Q. , Nothwang William D. , Bedair Sarah S. , Meyer Christopher D. , Polcawich Ronald G.
Published: April 2012

This review article presents recent advancements in the design and fabrication of thin‐film (<3 μm) lead zirconate titanate (PZT) microelectromechanical system (MEMS) devices. The article covers techniques for optimizing highly (001)/(100) oriented chemical solution deposited PZT films to achieve improved piezoelectric coefficients. These PZT films combined with surface and bulk micromachining techniques are fabricated into actuators and transducers for radio frequency (RF) switches, nanomechanical logic, resonators, and power transformers for use in communication systems and phased‐array radar. In addition, the large relative displacements generated by PZT thin films have been used to demonstrate mechanical mobility in MEMS devices, including insect‐inspired flight actuators and ultrasonic traveling wave motors. In conjunction with actuation, PZT films are being developed for feedback sensors for the integrated control of insect‐inspired robots.
Peri‐implantitis susceptibility as it relates to periodontal therapy and supportive care
Authors: Pjetursson Bjarni E. , Helbling Christoph , Weber Hans‐Peter , Matuliene Giedre , Salvi Giovanni E. , Brägger Urs , Schmidlin Kurt , Zwahlen Marcel , Lang Niklaus P.
Published: April 2012

Objective

To assess the long‐term survival of implants inserted in periodontally susceptible patients and to investigate the influence of residual pockets on the incidence of peri‐implantitis and implant loss.

Materials and methods

For 70 patients, comprehensive periodontal treatment was followed by installation of 165 Straumann® Dental implants. Subsequently, 58 patients entered a University supportive periodontal therapy (SPT) program and 12 had SPT in a private practice. The follow‐up time ranged from 3 to 23 years (mean 7.9 years). Bleeding on probing (BOP), clinical attachment level (CAL), and peri‐implant probing depths (PPD) were evaluated at baseline (T0), completion of active treatment (T1), and at follow‐up (T2). Peri‐implant bone levels were assessed on radiographs at T2. Patients were categorized as having implants not affected by peri‐implantitis (non‐PIP), or affected by peri‐implantitis (PIP).

Results

From 165 implants inserted, six implants were lost, translating into a cumulative survival rate of 95.8%. Solid screw implants yielded significantly higher survival rates than the hollow cylinder and hollow screw implants (99.1% vs. 89.7%). Implants lost due to peri‐implant infection were included in the PIP groups. When peri‐implantitis (PPD≥ 5 mm, BOP+) was analyzed, 22.2% of the implants and 38.6% of patients had one or more implants affected by peri‐implantitis. Using the peri‐implantitis definition (PPD≥6 mm, BOP+), the prevalence was reduced to 8.8% and 17.1%, respectively. Moreover, all these implants demonstrated significant (≥2 mm) bone loss at T2.

At T1, the non‐PIP group had significantly (P = 0.011) fewer residual pockets (≥5 mm) per patient than the PIP group (1.9 vs. 4.1). At T2, the PIP group displayed an increased number of residual pockets compared to T1, whereas in the non‐PIP group, the number remained similar to T1. At T2, mean PPD, mean CAL and BOP were significantly higher in the PIP group compared with the non‐PIP group. The prevalence of peri‐implantitis was lower in the group that was in a well organized SPT at the University.

Conclusions

In periodontitis susceptible patients, residual pockets (PPD ≥5 mm) at the end of active periodontal therapy represent a significant risk for the development of peri‐implantitis and implant loss. Moreover, patients in SPT developing re‐infections are at greater risk for peri‐implantitis and implant loss than periodontally stable patients.
Key Cellular Components and Interactive Histocompatibility Molecules Regulating Tolerance to the Fetal Allograft
Authors: Spencer Patrick S. , Hakam Soukaina M. , Laissue Phillipe P. , Jabeen Asma , Jain Pallavi , Hayrabedyan Soren , Todorova Krassimira , Blanch Alyssa , McElhinney James M.W.R. , Muhandiram Niwedhie , Alkhatib Shaza , Dealtry Gill B. , Miranda‐Sayago Jose M. , Fernández Nelson
Published: April 2012

Implantation is a major landmark in life. It involves the correct apposition of the embryo in the maternal endometrium. The cellular environment influences placenta development, and direct contact of the fetus with maternal tissues is achieved through decidual cells. At the decidua, and at systemic level, the correct balance of cells potentially acting as antigen‐presenting cells and histocompatibility products play a pivotal role in achieving feto–maternal tolerance. Here, we review some of the current issues associated with the interplay between cells and molecules needed for pregnancy development.
Improvement and validation of the method to determine neutral detergent fiber in feed
Authors: HIRAOKA Hisaaki , FUKUNAKA Rie , ISHIKURO Eiichi , ENISHI Osamu , GOTO Tetsuhisa
Published: April 2012

To improve the performance of the analytical method for neutral detergent fiber in feed with heat‐stable α‐amylase treatment (aNDFom), the process of adding heat‐stable α‐amylase, as well as other analytical conditions, were examined. In this new process, the starch in the samples was removed by adding amylase to neutral detergent (ND) solution twice, just after the start of heating and immediately after refluxing. We also examined the effects of the use of sodium sulfite, and drying and ashing conditions for aNDFom analysis by this modified amylase addition method. A collaborative study to validate this new method was carried out with 15 laboratories. These laboratories analyzed two samples, alfalfa pellet and dairy mixed feed, with blind duplicates. Ten laboratories used a conventional apparatus and five used a Fibertec® type apparatus. There were no significant differences in aNDFom values between these two refluxing apparatuses. The aNDFom values in alfalfa pellet and dairy mixed feed were 388 g/kg and 145 g/kg, the coefficients of variation for the repeatability and reproducibility (CVr and CVR) were 1.3% and 2.9%, and the HorRat values were 0.8 and 1.1, respectively. This new method was validated with 5.8% uncertainty (k = 2) from the collaborative study.
Regulation NMS and Market Quality
Authors: Chung Kee H. , Chuwonganant Chairat
Published: April 2012

We show that both the quoted and effective spreads increased, the quoted depth decreased, and the market quality index decreased after the implementation of Regulation National Market System (NMS) (Reg NMS). We also find an increase in the price impact of trades and the dispersion of the pricing error after Reg NMS. The order execution speed is slower, the order fill rate is lower, and the order cancellation rate is higher for most trades after Reg NMS. Hence, contrary to the Securities and Exchange Commission's belief, Reg NMS has proven to be detrimental to most traders. NASDAQ provided faster and more reliable executions than the NYSE/AMEX, and NASDAQ gained market shares from the NYSE/AMEX and other trading venues after Reg NMS.
Cerebrospinal Fluid Biomarkers in Alzheimer's Disease and Geriatric Depression: Preliminary Findings from Brazil
Authors: Reis Taylor , Brandão Carlos Otavio , Freire Coutinho Evandro Silva , Engelhardt Eliasz , Laks Jerson
Published: April 2012

Aims

Depression is a highly prevalent disorder in the elderly and one of the risk factors for developing dementia. The present study involves patients with Alzheimer's disease (AD), geriatric major depressive disorder (MDD) and cognitively healthy controls aiming to compare baseline cerebrospinal fluid (CSF) biomarkers.

Methods

The study included 52 patients with more than 60 years of age with a diagnosis of MDD, AD, and healthy controls. All individuals underwent a medical history, physical, and neurologic examination, laboratory tests and neuropsychological assessment to rule out any clinical diseases or disorders. Measurement of CSF P‐tau181, T‐tau, and Aβ42 was performed using commercial assays (ELISA).

Results

CSF Aβ42 levels of depressed patients and normal controls were significantly higher than in AD. There was not any significant difference in measures of P‐tau among the groups. T‐tau, however, showed to be significantly different among the groups, with higher measures in AD group. Higher levels of P‐tau were observed in four MDD patients compared with controls.

Conclusion

CSF Aβ42, T‐tau, and P‐tau levels may differentiate between AD and depression in a Brazilian sample.
Agglomeration, Related Variety, and Vertical Integration
Authors: Cainelli Giulio , Iacobucci Donato
Published: April 2012

abstract

Several recent studies have investigated the relationship between the geographic concentration of production and vertical integration, based on the hypothesis that the spatial agglomeration of firms in the same industry facilitates input procurement, thereby reducing the degree of vertical integration. This article contributes to this debate in two ways: first, we focus on interindustry vertical integration, and second, we consider the effects on vertical integration of unrelated and vertically related variety at the local level. The latter was measured using information from input‐output tables and captured the opportunities for outsourcing within the local system. A data set of 24,663 Italian business groups in 2001 was used to estimate Tobit models to investigate the influence of vertically related variety and other agglomeration forces on the degree of vertical integration of groups. We found that vertical integration is influenced by industry specialization at the local level and that higher vertically related variety reduces the need for firms to integrate activities, since they have more opportunities to acquire intermediate goods and services within the local system. We analyze the manufacturing and different macroareas and show that this relationship is also influenced by technology and differences in the organization of economic activities at the local level.
Assessing the Influence of Fourier Analysis Parameters on Short-Time Modal Parameter Extraction
Authors: Lamb Matthew , Rouillard Vincent
Published: April 2012

It is sometimes necessary to determine the manner in which materials and structures deteriorate with respect to time when subjected to sustained random dynamic loads. In such cases a system’s fatigue characteristics can be obtained by continuously monitoring its modal parameters. This allows for any structural deterioration, often manifested as a loss in stiffness, to be detected. Many common structural integrity assessment techniques make use of Fourier analysis for modal parameter extraction. For continual modal parameter extraction, the Fourier transform requires that a compromise be made between the accuracy of the estimates and how frequently they can be obtained. The limitations brought forth by this compromise can be significantly reduced by selecting suitable values for the analysis parameters, mainly subrecord length and number of averages. Further improvements may also be possible by making use of spectral enhancement techniques, specifically overlapped averaging and zero padding. This paper uses the statistical analysis of results obtained from numerous physical and numerical experiments to evaluate the influence of the analysis parameters and spectral enhancement techniques on modal estimates obtained from limited data sets. This evaluation will assist analysts in selecting the most suitable inputs for parameter extraction purposes. The results presented in this paper show that when using the Fourier transform to extract modal characteristics, any variation in the parameters used for analysis can have a significant influence on the extraction of natural frequency estimates from systems subjected to random excitation. It was found that for records containing up to 10% noise, subrecord length; hence spectral resolution, has a more pronounced influence on the accuracy of modal estimates than the level of spectral averaging; therefore spectral uncertainty. It was also found that while zero padding may not increase the actual spectral resolution, it does allow for improved natural frequency estimates with the introduction of interpolated estimates at the nondescribed frequencies. Finally, it was found that for modal parameter extraction purposes (in this case natural frequency), increased amounts of overlapped averaging can significantly reduce the variance of the estimates obtained. This is particularly useful as it allows for increased precision without compromising temporal resolution.
Estimation of Milling Tool Temperature Considering Coolant and Wear
Authors: Kuo Hsin-Yu , Meyer Kevin , Lindle Roger , Ni Jun
Published: April 2012

This paper presents a novel technique to estimate the temperature distribution of a milling tool during machining. In this study, heat generation during the machining process is estimated using cutting forces. We consider the heat to be time-dependent heat flux into the tool. In the proposed model, we discretize each rake face on a mill into several elements; each experiences time-dependent heat flux. Second, we calculate the time-dependent heat flux as several constant heat input starts at different time. Finally, we sum the temperature rise from each heat flux to obtain the overall temperature change. A similar concept is applied on the flank surface, where the flank wear area is modeled as an additional heat generation zone. Experimental results are presented to validate the developed model.
An Equivalent Plate Model for Sandwiched Panels With Thermoviscous
Fluid Core
Authors: Inayat Hussain Husnain , Guyader Jean-Louis
Published: April 2012

A method has been developed to predict the damping behavior of an equivalent plate formed from sandwich panels with a thermoviscous fluid core, which is based on an asymptotic approach. The technique works on the break-up of the basic physical quantities such as pressure, temperature, and particle velocities as constants and linear functions of the z coordinate, which signifies the perpendicular direction from the plate mid-surface. The asymptotic modeling is performed in a very thin and highly thermoviscous fluid layer on the full set of linearized Navier Stokes equations. The use of highly viscous fluid layers such as Rhodorsil® 47 oils, yields high damping loss factors, which are of the order of 10−1. The effects of the panel thickness and the fluid core thickness are also studied. It is shown that the damping loss factor of the equivalent plate is independent of the frequency. Experimental validation provides a good agreement with the theoretical results.
An Experimental and Numerical Investigation on Polymer Melt Injected Sheet Metal Forming
Authors: Hussain Muhammad Masood , Trompeter Michael , Witulski Jörg , Tekkaya A. Erman
Published: April 2012

Polymer injection forming (PIF) is a recent advancement in manufacturing of plastic– metal hybrid products. It is a combination of injection molding and sheet metal forming in which the molten polymer additionally serves as a pressure medium. This paper presents fundamental investigations on the use of polymer melt as a pressure medium in sheet metal forming. The development of forming pressure and localized blank temperature as a result of polymer injection is analyzed. The experiments are performed using aluminum alloy. The experiments comprise the bulging of a (free form) dome and stretch forming of a cup using thermoplastic polypropylene as a pressure medium. A simple approach is presented to model a combined process. An incremental lagrangian formulation is used to describe the polymer flow and sheet metal deformation. The Newtonian behavior of the polymer melt is modeled as rigid-viscoplastic medium. Standard finite element coupling is used to model the mutual metal–polymer interaction. The simulation results in the form of forming pressure profile, localized blank temperature profile, formed shape, and strain distribution are presented and validated with experimentally obtained results.
Performance Analysis of Finite Element and Energy Based Analytical Methods for Modeling of PCLD Treated Beams
Authors: Kumar Sanjiv , Kumar Rajiv , Sehgal Rakesh
Published: April 2012

For active/passive vibration control applications, low order models of flexible structures are always preferable. Mathematical models of passive constrained layer damping (PCLD)/active constrained layer damping (ACLD) treatment generated by energy based analytical methods are of much smaller orders as compared to finite element methods (FEM). Using these analytical methods, one can get rid of complex model reduction techniques, since these model reduction techniques are subjected to errors if applied directly to PCLD or ACLD systems. However, analytical techniques cannot be applied blindly to any PCLD system. There is significant error in loss factor prediction for certain boundary conditions. This error is also dependent on the relative thicknesses of Viscoelastic material layer, constraining layer and base beam. For certain combination of the above thicknesses and under certain boundary conditions, the models generated are useless for controller design purposes. On the other hand, FEM are highly robust and can be applied easily to any set of boundary conditions with guaranteed accuracy. Also, results predicted by this method are of high accuracy for any combinations of thicknesses of different layers. The only disadvantage of this technique is the high order of the developed model. Detailed performance comparison of both the techniques to predict the modal parameters of the PCLD treated beam is presented.
Optimal Compliant Flapping Mechanism Topologies With Multiple Load Cases
Authors: Stanford Bret , Beran Philip
Published: April 2012

The conceptual design of effective actuation mechanisms for flapping wing micro air vehicles presents considerable challenges, with competing weight, power, authority, and life cycle requirements. This work utilizes topology optimization to obtain compliant flapping mechanisms; this is a well-known tool, but the method is rarely extended to incorporate unsteady nonlinear aeroelastic physics, which must be accounted for in the design of flapping wing vehicles. Compliant mechanism topologies are specifically desired to perform two tasks: (1) propulsive thrust generation (symmetric motions of a left and a right wing) and (2) lateral roll moment generation (asymmetric motions). From an optimization standpoint, these two tasks are considered multiple load cases, implemented by scheduling the actuation applied to the mechanism’s design domain. Mechanism topologies obtained with various actuation-scheduling assumptions are provided, along with the resulting flapping wing motions and aerodynamic force/moment generation. Furthermore, it is demonstrated that both load cases may be used simultaneously for future vehicle control studies: gradual transition from forward flight into a turning maneuver, for example.
Pumpless Fuel Supply Using Pressurized Fuel Regulated by Autonomous Flow-Rate Regulation Valves
Authors: Doh Il , Cho Young-Ho
Published: April 2012

A pumpless fuel supply using pressurized fuel with autonomous flow regulation valves is presented. Since micropumps and their control circuitry consume a portion of the electrical power generated in fuel cells, fuel supply without micropumps makes it possible to provide more efficient and inexpensive fuel cells than conventional ones. The flow regulation valves in the present system maintain the constant fuel flow rate from the pressurized fuel chamber even though the fuel pressure decreases. They autonomously adjust fluidic resistance of the channel according to fuel pressure so as to maintain constant flow rate. Compared to previous pumpless fuel supply methods, the present method offers more uniform fuel flow without any fluctuation using a simple structure. The prototypes were fabricated by a polymer micromolding process. In the experimental study using the pressurized deionized water, prototypes with pressure regulation valves showed constant flow rate of 5.38 ± 0.52 μl/s over 80 min and 5.89 ± 0.62 μl/s over 134 min, for the initial pressure in the fuel chamber of 50 and 100 kPa, respectively, while the other prototypes having the same fluidic geometry without flow regulation valves showed higher and gradually decreasing flow rate. The present pumpless fuel supply method providing constant flow rate with autonomous valve operation will be beneficial for the development of next-generation fuel cells.
Graphical Facial
Expression Analysis and Design Method: An Approach to Determine Humanoid Skin
Deformation
Authors: Tadesse Yonas , Priya Shashank
Published: April 2012

The architecture of human face is complex consisting of 268 voluntary muscles that perform coordinated action to create real-time facial expression. In order to replicate facial expression on humanoid face by utilizing discrete actuators, the first and foremost step is the identification of a pair of origin and sinking points (SPs). In this paper, we address this issue and present a graphical analysis technique that could be used to design expressive robotic faces. The underlying criterion in the design of faces being deformation of a soft elastomeric skin through tension in anchoring wires attached on one end to the skin through the sinking point and the other end to the actuator. The paper also addresses the singularity problem of facial control points and important phenomena such as slacking of actuators. Experimental characterization on a prototype humanoid face was performed to validate the model and demonstrate the applicability on a generic platform.
Electrochemical properties of sputter-deposited MoO3 films in lithium microbatteries
Authors: Ramana C. V. , Atuchin V. V. , Groult H. , Julien C. M.
Published: April 2012

Molybdenum oxide (MoO3) films were prepared by magnetron sputtering using an Mo target. The films were sputtered in the reactive atmosphere of an argon–oxygen gas mixture under various substrate temperatures, Ts, and oxygen partial pressures, p(O2). The effects of the growth conditions on the microstructure were examined using reflection high-energy electron diffraction and x-ray photoelectron spectroscopy. The analyses indicate that stoichiometric and polycrystalline MoO3 films were obtained at Ts = 445 °C and p(O2) = 61%. The applicability of the sputtered MoO3 films for lithium microbattery application has been demonstrated. The discharge–charge profiles, the kinetics of lithium intercalation process in the film, and the cycling behavior have been investigated in detail to understand the effect of microstructure on the electrochemical performance.
Valley and spin polarization from graphene line defect scattering
Authors: Gunlycke Daniel , White Carter T.
Published: April 2012

Quantum transport calculations describing electron scattering off an extended line defect in graphene are presented. The calculations include potentials from local magnetic moments recently predicted to exist on sites adjacent to the line defect. The transmission probability is derived and expressed as a function of valley, spin, and angle of incidence of an electron at the Fermi level being scattered. It is shown that the previously predicted valley polarization in a beam of transmitted electrons is not significantly influenced by the presence of the magnetic moments. These moments, however, do introduce some spin polarization, in addition to the valley polarization, albeit no more than about 20%.