bluuebunny/crossref_metadata_2025 huggingface dataset:
Profiles of Dental Caries and Periodontal Disease in Individuals With or Without Psoriasis
Authors: Fadel Hani T. , Flytström Ingela , Calander Ann‐Marie , Bergbrant Ing‐Marie , Heijl Lars , Birkhed Dowen
Published: May 2012

Background: Psoriasis is a chronic inflammatory disease that is manifested on the skin. Studies of oral health in psoriasis patients are limited. The aim of this study is to assess the experience and risk of caries and periodontal disease in individuals with and without psoriasis.

Methods: The material consisted of 89 individuals with mild‐to‐moderate chronic plaque psoriasis and 54 without psoriasis, recruited at the University Hospital in Gothenburg, Gothenburg, Sweden. Psoriatic arthritis (PsoA) was diagnosed in 25 of the individuals with psoriasis. All participants answered questionnaires and were subjected to saliva sampling and oral radiologic and clinical examinations. Two computer applications were used for illustration of oral disease risk profiles.

Results: Individuals with psoriasis had lower salivary pH, fewer remaining teeth, fewer sites with probing depth ≤4 mm, and a lower radiographic alveolar bone level than individuals without psoriasis (P <0.05). Most of the differences remained significant after controlling for confounders. Differences in alveolar bone levels were no longer significant, particularly after introducing the confounder sex into the regression model. Similar numbers of decayed and filled teeth, sites with deep pockets, sites that bled on probing, and risk profiles were observed. Individuals with PsoA exhibited a lower stimulated salivary secretion rate than those without psoriasis (P <0.05).

Conclusions: There were no differences in profiles of caries and periodontal disease experience and risk between individuals with and without psoriasis. Fewer remaining teeth were observed in individuals with psoriasis. However, the exact reason for tooth loss could not be identified. Meanwhile, the reduced salivary pH in individuals with psoriasis and salivary secretion in individuals with PsoA may pose some risk for future caries.
Comparing Mandated Health Care Reforms
Authors: Watnick Suzanne , Weiner Daniel E. , Shaffer Rachel , Inrig Jula , Moe Sharon , Mehrotra Rajnish
Published: May 2012

In addition to extending health insurance coverage, the Affordable Care Act of 2010 aims to improve quality of care and contain costs. To this end, the act allowed introduction of bundled payments for a range of services, proposed the creation of accountable care organizations (ACOs), and established the Centers for Medicare and Medicaid Innovation to test new care delivery and payment models. The ACO program began April 1, 2012, along with demonstration projects for bundled payments for episodes of care in Medicaid. Yet even before many components of the Affordable Care Act are fully in place, the Medicare ESRD Program has instituted legislatively mandated changes for dialysis services that resemble many of these care delivery reform proposals. The ESRD program now operates under a fully bundled, case-mix adjusted prospective payment system and has implemented Medicare’s first-ever mandatory pay-for-performance program: the ESRD Quality Incentive Program. As ACOs are developed, they may benefit from the nephrology community’s experience with these relatively novel models of health care payment and delivery reform. Nephrologists are in a position to assure that the ACO development will benefit from the ESRD experience. This article reviews the new ESRD payment system and the Quality Incentive Program, comparing and contrasting them with ACOs. Better understanding of similarities and differences between the ESRD program and the ACO program will allow the nephrology community to have a more influential voice in shaping the future of health care delivery in the United States.
Habitual Physical Activity After Total Knee Replacement
Authors: Kersten Roel F.M.R. , Stevens Martin , van Raay Jos J.A.M. , Bulstra Sjoerd K. , van den Akker-Scheek Inge
Published: May 2012

Background

Previous studies on physical activity after total knee arthroplasty (TKA) concentrated mainly on a return to sports activities.

Objective

The objectives of this study were to determine the habitual physical activity behavior of people who had undergone TKA (TKA group) 1 to 5 years after surgery and to examine to what extent they adhered to international guidelines for health-enhancing physical activity. Additional aims were to compare younger (<65 years old) and older (≥65 years old) people as well as men and women in the TKA group and to compare the results for the TKA group with those for a sex- and age-matched normative population (normative group).

Design

This investigation was a cohort study.

Methods

All people who had a primary TKA at 1 of 2 participating hospitals between 2002 and 2006 were sent the Short Questionnaire to Assess Health-Enhancing Physical Activity at least 1 year after surgery.

Results

The TKA group spent, on average, 1,347 minutes per week on physical activity, most of which was light-intensity activity (780 minutes per week). Participants younger than 65 years of age spent significantly more time on physical activity than participants 65 years of age or older. There was no significant difference between male and female participants. Compared with the sex- and age-matched normative group, the TKA group spent significantly less time on the total amount of physical activity per week and met the guidelines for health-enhancing physical activity less often (55% versus 64%).

Limitations

A self-administered questionnaire was used to assess habitual physical activity, and presurgery data on physical activity were not available.

Conclusions

Almost half of the TKA group did not meet the health-enhancing physical activity guidelines, and the TKA group was not as physically active as the normative group. People who have undergone TKA should be encouraged to be more physically active.
Influence of Fear-Avoidance Beliefs on Functional Status Outcomes for People With Musculoskeletal Conditions of the Shoulder
Authors: Sindhu Bhagwant S. , Lehman Leigh A. , Tarima Sergey , Bishop Mark D. , Hart Dennis L. , Klein Matthew R. , Shivakoti Mikesh , Wang Ying-Chih
Published: May 2012

Background

The influence of elevated fear-avoidance beliefs on change in functional status is unclear.

Objective

The purpose of this study was to determine the influence of fear-avoidance on recovery of functional status during rehabilitation for people with shoulder impairments.

Design

A retrospective longitudinal cohort study was conducted.

Methods

Data were collected from 3,362 people with musculoskeletal conditions of the shoulder receiving rehabilitation. At intake and discharge, upper-extremity function was measured using the shoulder Computerized Adaptive Test. Pain intensity was measured using an 11-point numerical rating scale. Completion rate at discharge was 57% for function and 47% for pain intensity. A single-item screen was used to classify patients into groups with low versus elevated fear-avoidance beliefs at intake. A general linear model (GLM) was used to describe how change in function is affected by fear avoidance in 8 disease categories. This study also accounted for within-clinic correlation and controlled for other important predictors of functional change in functional status, including various demographic and health-related variables. The parameters of the GLM and their standard errors were estimated with the weighted generalized estimating equations method.

Results

Functional change was predicted by the interaction between fear and disease categories. On further examination of 8 disease categories using GLM adjusted for other confounders, improvement in function was greater for the low fear group than for the elevated fear group among people with muscle, tendon, and soft tissue disorders (Δ=1.37, P<.01) and those with osteopathies, chondropathies, and acquired musculoskeletal deformities (Δ=5.52, P<.02). These differences were below the minimal detectable change.

Limitations

Information was not available on whether therapists used information on level of fear to implement treatment plans.

Conclusions

The influence of fear-avoidance beliefs on change in functional status varies among specific shoulder impairments.
A Cane Improves Postural Recovery From an Unpracticed Slip During Walking in People With Parkinson Disease
Authors: Boonsinsukh Rumpa , Saengsirisuwan Vitoon , Carlson-Kuhta Patricia , Horak Fay B.
Published: May 2012

Background

Little is known about the effects of use of a cane on balance during perturbed gait or whether people with Parkinson disease (PD) benefit from using a cane.

Objectives

The purpose of this study was to evaluate the effects of cane use on postural recovery from a slip due to repeated surface perturbations in individuals with PD compared with age- and sex-matched individuals who were healthy.

Design

This was a prospective study with 2 groups of participants.

Methods

Fourteen individuals with PD (PD group) and 11 individuals without PD (control group) walked across a platform that translated 15 cm rightward at 30 cm/s during the single-limb support phase of the right foot. Data from 15 trials in 2 conditions (ie, with and without an instrumented cane in the right hand) were collected in random order. Outcome measures included lateral displacement of body center of mass (COM) due to the slip and compensatory step width and length after the perturbation.

Results

Cane use improved postural recovery from the first untrained slip, characterized by smaller lateral COM displacement, in the PD group but not in the control group. The beneficial effect of cane use, however, occurred only during the first perturbation, and those individuals in the PD group who demonstrated the largest COM displacement without a cane benefited the most from use of a cane. Both PD and control groups gradually decreased lateral COM displacement across slip exposures, but a slower learning rate was evident in the PD group participants, who required 6, rather than 3, trials for adapting balance recovery.

Limitations

Future studies are needed to examine the long-term effects of repeated slip training in people with PD.

Conclusions

Use of a cane improved postural recovery from an unpracticed slip in individuals with PD. Balance in people with PD can be improved by training with repeated exposures to perturbations.
Suppression of thalamocortical oscillations following traumatic brain injury in rats
Authors: Kao Chris , Forbes Jonathan A. , Jermakowicz Walter J. , Sun David A. , Davis Brandon , Zhu Jiepei , Lagrange Andre H. , Konrad Peter E.
Published: May 2012

Object

Traumatic brain injury (TBI) often causes an encephalopathic state, corresponding amplitude suppression, and disorganization of electroencephalographic activity. Clinical recovery in patients who have suffered TBI varies, and identification of patients with a poor likelihood of functional recovery is not always straightforward. The authors sought to investigate temporal patterns of electrophysiological recovery of neuronal networks in an animal model of TBI. Because thalamocortical circuit function is a critical determinant of arousal state, as well as electroencephalography organization, these studies were performed using a thalamocortical brain slice preparation.

Methods

Adult rats received a moderate parietal fluid-percussion injury and were allowed to survive for 1 hour, 2 days, 7 days, or 15 days prior to in vitro electrophysiological recording. Thalamocortical brain slices, 450-μm thick, were prepared using a cutting angle that preserved reciprocal connections between the somatosensory cortex and the ventrobasal thalamic complex.

Results

Extracellular recordings in the cortex of uninjured control brain slices revealed spontaneous slow cortical oscillations (SCOs) that are blocked by (2R)-amino-5-phosphonovaleric acid (50 μM) and augmented in low [Mg2+]o. These oscillations have been shown to involve simultaneous bursts of activity in both the cortex and thalamus and are used here as a metric of thalamocortical circuit integrity. They were absent in 84% of slices recorded at 1 hour postinjury, and activity slowly recovered to approximate control levels by Day 15. The authors next used electrically evoked SCO-like potentials to determine neuronal excitability and found that the maximum depression occurred slightly later, on Day 2 following TBI, with only 28% of slices showing evoked activity. In addition, stimulus intensities needed to create evoked SCO activity were elevated at 1 hour, 2 days, and 7 days following TBI, and eventually returned to control levels by Day 15. The SCO frequency remained low throughout the 15 days following TBI (40% of control by Day 15).

Conclusions

The suppression of cortical oscillatory activity following TBI observed in the rat model suggests an injury-induced functional disruption of thalamocortical networks that gradually recovers to baseline at approximately 15 days postinjury. The authors speculate that understanding the processes underlying disrupted thalamocortical circuit function may provide important insights into the biological basis of altered consciousness following severe head injury. Moreover, understanding the physiological basis for this process may allow us to develop new therapies to enhance the rate and extent of neurological recovery following TBI.
Vibrations of Mertz Glacier ice tongue, East Antarctica
Authors: Lescarmontier L. , Legrésy B. , Coleman R. , Perosanz F. , Mayet C. , Testut L.
Published: May 2012

At the time of its calving in February 2010, Mertz Glacier, East Antarctica, was characterized by a 145 km long, 35 km wide floating tongue. In this paper, we use GPS data from the Collaborative Research into Antarctic Calving and Iceberg Evolution (CRAC-ICE) 2007/08 and 2009/10 field seasons to investigate the dynamics of Mertz Glacier. Two months of data were collected at the end of the 2007/08 field season from two kinematic GPS stations situated on each side of the main rift of the glacier tongue and from rock stations located around the ice tongue during 2008/09. Using Precise Point Positioning with integer ambiguity fixing, we observe that the two GPS stations recorded vibrations of the ice tongue with several dominant periods. We compare these results with a simple elastic model of the ice tongue and find that the natural vibration frequencies are similar to those observed. This information provides a better understanding of their possible effects on rift propagation and hence on the glacier calving processes.
A physically based method for estimating supraglacial debris thickness from thermal band remote-sensing data
Authors: Foster L.A. , Brock B.W. , Cutler M.E.J. , Diotri F.
Published: May 2012

In order to account for the effects of debris cover in model scenarios of the response of glaciers to climate change and water resource planning, it is important to know the distribution and thickness of supraglacial debris and to monitor its change over time. Previous attempts to map surface debris thickness using thermal band remote sensing have relied upon time-specific empirical relationships between surface temperature and thickness, limiting their general applicability. In this paper, we develop a physically based model that utilizes Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) thermal band remotely sensed imagery and is based on a solution of the energy balance at the debris surface. The model is used to estimate debris thickness on Miage glacier, Italy, and is validated using field debris-thickness measurements and a previously published debris-thickness map. The temporal transferability of the model is demonstrated through successful application to a separate ASTER image from a different year using reanalysis meteorological input data. This model has the potential to be used for regional-scale supraglacial debris-thickness mapping and monitoring for debris up to at least 0.50 m thickness, but improved understanding of the spatial patterns of air temperature, aerodynamic roughness length and thermal properties across debris-covered glaciers is needed.
Geospatial Analysis Application to Forecast Wildfire Occurrences in South Carolina
Authors: Feltman Joel A. , Straka Thomas J. , Post Christopher J. , Sperry Stephen L.
Published: May 2012

Wildfire occurrence and intensity have increased over the last few decades and, at times, have been national news. Wildfire occurrence is somewhat predictable based on physical factors like meteorological conditions, fuel loads, and vegetation dynamics. Socioeconomic factors have been not been widely used in wildfire occurrence models. We used a geospatial (or geographical information system) analysis approach to identify socioeconomic variables that contribute to wildfire occurrence. Key variables considered were population change, population density, poverty rate, educational level, geographic mobility, and road density (transportation network). Hot spot analysis was the primary research tool. Wildfire occurrence seemed to be positively related to low population densities, low levels of population change, high poverty rate, low educational attainment level, and low road density. Obviously, some of these variables are correlated and this is a complex problem. However, socioeconomic variables appeared to contribute to wildfire occurrence and should be considered in development of wildfire occurrence forecasting models.
A Novel Preparation Method for 5-Aminosalicylic Acid Loaded Eudragit S100 Nanoparticles
Authors: Hu Daode , Liu Liang , Chen Wenjuan , Li Sining , Zhao Yaping
Published: May 2012

In this study, solution enhanced dispersion by supercritical fluids (SEDS) technique was applied for the preparation of 5-aminosalicylic acid (5-ASA) loaded Eudragit S100 (EU S100) nanoparticles. The effects of various process variables including pressure, temperature, 5-ASA concentration and solution flow rate on morphology, particle size, 5-ASA loading and entrapment efficiency of nanoparticles were investigated. Under the appropriate conditions, drug-loaded nanoparticles exhibited a spherical shape and small particle size with narrow particle size distribution. In addition, the nanoparticles prepared were characterized by X-ray diffraction, Differential scanning calorimetry and Fourier transform infrared spectroscopy analyses. The results showed that 5-ASA was imbedded into EU S100 in an amorphous state after SEDS processing and the SEDS process did not induce degradation of 5-ASA.
Anti-Proliferation and Anti-Invasion Effects of Diosgenin on Gastric Cancer BGC-823 Cells with HIF-1α shRNAs
Authors: Mao Zhu-Jun , Tang Qian-Jue , Zhang Ci-An , Qin Zhi-Feng , Pang Bin , Wei Pin-kang , Liu Bo , Chou Yuan-Neng
Published: May 2012

Drug resistance is a major factor for the limited efficacy of chemotherapy in gastric cancer treatment. Hypoxia-inducible factor-1α (HIF-1α), a central transcriptional factor in hypoxia, is suggested to participate in the resistance. Here, we identified a hypoxia-mimic (cobalt chloride) sensitive gastric cell line BGC-823 to explore whether diosgenin, an aglycone of steroidal saponins, can inhibit cancer cell invasion and survival of solid tumor in a hypoxic mimic microenvironment. We have shown that diosgenin is a potent candidate for decreasing the ability of invasion and survival in cobalt chloride treated BGC-823 cells. In addition, when combined with HIF-1α specific short hairpin RNA (shRNA), diosgenin can inhibit BGC-823 cells more effectively. The anti-invasion role of diosgenin may be related to E-cadherin, integrinα5 and integrinβ6. These results suggest that diosgenin may be a useful compound in controlling gastric cancer cells in hypoxia condition, especially when combined with down-regulated HIF-1α.
Heavy Ion Characterization of a Radiation Hardened Flip-Flop Optimized for Subthreshold Operation
Authors: Chavan Ameet , Palakurthi Praveen , MacDonald Eric , Neff Joseph , Bozeman Eric
Published: May 2012

A novel Single Event Upset (SEU) tolerant flip-flop design is proposed, which is well suited for very-low power electronics that operate in subthreshold ( < Vt ≈ 500 mV). The proposed flip-flop along with a traditional (unprotected) flip-flop, a Sense-Amplifier-based Rad-hard Flip-Flop (RSAFF) and a Dual Interlocked storage Cell (DICE) flip-flop were all fabricated in MIT Lincoln Lab’s XLP 0.15 μm fully-depleted SOI CMOS technology—a process optimized for subthreshold operation. At the Cyclotron Institute at Texas A&M University, all four cells were subjected to heavy ion characterization in which the circuits were dynamically updated with alternating data and then checked for SEUs at both subthreshold (450 mV) and superthreshold (1.5 V) levels. The proposed flip-flop never failed, while the traditional and DICE designs did demonstrate faulty behavior. Simulations were conducted with the XLP process and the proposed flip-flop provided an improved energy delay product relative to the other non-faulty rad-hard flip-flop at subthreshold voltage operation. According to the XLP models operating in subthreshold at 250 mV, performance was improved by 31% and energy consumption was reduced by 27%.
Chiral Bis(Imidazolidine)Pyridine-Cu Complex-Catalyzed Enantioselective [3+2]-Cycloaddition of Azomethine Imines with Propiolates
Authors: Arai Takayoshi , Ogino Yuta
Published: May 2012

[3+2] Cycloaddition of azomethine imines with electron-deficient terminal alkynes was smoothly catalyzed by a chiral bis(imidazolidine)pyridine-CuOAc complex to give bicyclic pyrazolo[1,2-a]pyrazolone derivatives with up to 74% ee.
Antiatherogenic Properties of Acetone Extract of Alpinia zerumbet Seeds
Authors: Chompoo Jamnian , Upadhyay Atul , Gima Shinichi , Fukuta Masakazu , Tawata Shinkichi
Published: May 2012

Oxidation of low-density lipoprotein (LDL) is the principal risk factor for the development of atherosclerosis. In this study, we used several methods to investigate the ability of the acetone extract from rhizomes, stems, leaves, flowers, pericarps and seeds of Alpinia zerumbet to inhibit atherosclerosis in vitro. The seed extract had the strongest activity against tyrosinase, pancreatic lipase (PL), 15-lipoxygenase (15-LO) and LDL oxidation activities (IC50 = 2.30 ± 0.02, 5.00 ± 0.07, 1.29 ± 0.07 and 15.40 ± 0.86 µg/mL, respectively), amongst all different parts. It also had similar effects to the positive controls. Most of the extracts showed partial agonistic properties towards estrogenic activity. Cholest-4-ene-3,6-dione, a steroid present only in the seed extract seems to be the compound responsible for these activities. The results showed that cholest-4-ene-3,6-dione had similar ability to curcumin and quercetin against PL and LDL oxidation (IC50 = 19.50 ± 1.17 and 16.12 ± 1.43 µg/mL, respectively). Furthermore, cholest-4-ene-3,6-dione (IC50 = 34.21 ± 1.31 µg/mL) had higher inhibition against 15-LO than quercetin (IC50 = 54.79 ± 1.12 µg/mL).
Synthesis and Biological Evaluation of Novel N-Methyl-picolinamide-4-thiol Derivatives as Potential Antitumor Agents
Authors: Huang Ting-Ting , Huang Yun-Chuang , Qing Xiao-Yu , Xia Yong , Luo Xun , Ye Ting-Hong , Yu Luo-Ting
Published: May 2012

A novel series of N-methylpicolinamide-4-thiol derivatives were synthesized and evaluated on human cancer cell lines. Among them, compound 6p displayed potent and broad-spectrum anti-proliferative activities in vitro on some human cancer cell lines, even better than sorafenib. The advanced kinase inhibitory assays showed that compound 6p could selectively inhibit Aurora-B kinase. The biological results were rationalized by the molecular docking study, which indicated the stable interactions of 6p with the Aurora-B kinase.
Phenolics and Flavonoids Compounds, Phenylanine Ammonia Lyase and Antioxidant Activity Responses to Elevated CO2 in Labisia pumila (Myrisinaceae)
Authors: Jaafar Hawa Z.E. , Ibrahim Mohd Hafiz , Karimi Ehsan
Published: May 2012

A split plot 3 × 3 experiment was designed to examine the impact of three concentrations of CO2 (400, 800 and 1,200 µmol·mol−1) on the phenolic and flavonoid compound profiles, phenylalanine ammonia lyase (PAL) and antioxidant activity in three varieties of Labisia pumila Benth. (var. alata, pumila and lanceolata) after 15 weeks of exposure. HPLC analysis revealed a strong influence of increased CO2 concentration on the modification of phenolic and flavonoid profiles, whose intensity depended on the interaction between CO2 levels and L. pumila varieties. Gallic acid and quercetin were the most abundant phenolics and flavonoids commonly present in all the varieties. With elevated CO2 (1,200 µmol·mol−1) exposure, gallic acid increased tremendously, especially in var. alata and pumila (101–111%), whilst a large quercetin increase was noted in var. lanceolata (260%), followed closely by alata (201%). Kaempferol, although detected under ambient CO2 conditions, was undetected in all varieties after exposure. Instead, caffeic acid was enhanced tremendously in var. alata (338~1,100%) and pumila (298~433%). Meanwhile, pyragallol and rutin were only seen in var. alata (810 µg·g−1 DW) and pumila (25 µg·g−1 DW), respectively, under ambient conditions; but the former compound went undetected in all varieties while rutin continued to increase by 262% after CO2 enrichment. Interestingly, naringenin that was present in all varieties under ambient conditions went undetected under enrichment, except for var. pumila where it was enhanced by 1,100%. PAL activity, DPPH and FRAP also increased with increasing CO2 levels implying the possible improvement of health-promoting quality of Malaysian L. pumila under high CO2 enrichment conditions.
Joint Torque Reduction of a Three Dimensional Redundant Planar Manipulator
Authors: Yahya Samer , Moghavvemi Mahmoud , Almurib Haider Abbas F.
Published: May 2012

Research on joint torque reduction in robot manipulators has received considerable attention in recent years. Minimizing the computational complexity of torque optimization and the ability to calculate the magnitude of the joint torque accurately will result in a safe operation without overloading the joint actuators. This paper presents a mechanical design for a three dimensional planar redundant manipulator with the advantage of the reduction in the number of motors needed to control the joint angle, leading to a decrease in the weight of the manipulator. Many efforts have been focused on decreasing the weight of manipulators, such as using lightweight joints design or setting the actuators at the base of the manipulator and using tendons for the transmission of power to these joints. By using the design of this paper, only three motors are needed to control any n degrees of freedom in a three dimensional planar redundant manipulator instead of n motors. Therefore this design is very effective to decrease the weight of the manipulator as well as the number of motors needed to control the manipulator. In this paper, the torque of all the joints are calculated for the proposed manipulator (with three motors) and the conventional three dimensional planar manipulator (with one motor for each degree of freedom) to show the effectiveness of the proposed manipulator for decreasing the weight of the manipulator and minimizing driving joint torques.
Effects of Two Varieties of Bacillus thuringiensis Maize on the Biology of Plodia interpunctella
Authors: Gryspeirt Aiko , Grégoire Jean-Claude
Published: May 2012

On the market since 1996, genetically modified plants expressing an insecticidal toxin (Cry toxin stemmed from Bacillus thuringiensis) target several lepidopteran and coleopteran pests. In this study, we assessed the impact of two varieties of Bt maize producing different toxins (Cry1Ab or Cry1Fa, respectively) on the biology of a storage pest: Plodia interpunctella (Hübner) (Lepidoptera: Pyralidae). The Indianmeal moths were susceptible to both toxins but showed an escape behavior only from Cry1Fa. The weight of females issued from larvae reared on Cry1Ab increased with increasing toxin concentration, but adults of both sexes reared on Cry1Fa had decreased weight. Both toxins increased development time from egg to adult regardless of sex and had no impact on the male adult lifespan. Finally, we recorded a time lag between metamorphosis from the non-Bt and the Bt diets, which increased proportionally to Cry concentration in the Bt diet.
EXISTENCE OF MULTIPLE POSITIVE SOLUTIONS FOR QUASILINEAR ELLIPTIC SYSTEMS INVOLVING CRITICAL HARDY–SOBOLEV EXPONENTS AND SIGN-CHANGING WEIGHT FUNCTION
Authors: Nyamoradi Nemat
Published: May 2012

In this paper, we consider a class of quasilinear elliptic systems with weights and the nonlinearity involving the critical Hardy–Sobolev exponent and one sign-changing function. The existence and multiplicity results of positive solutions are obtained by variational methods.
INVOLVING FUZZY ORDERS FOR MULTI-OBJECTIVE LINEAR PROGRAMMING
Authors: Grigorenko Olga
Published: May 2012

This paper presents a solution approach for multi-objective linear programming problem. We propose to involve fuzzy order relations to describe the objective functions where in ”classical” fuzzy approach the membership functions which illustrate how far the concrete point is from the solution of individual problem are studied. Further the global fuzzy order relation is constructed by aggregating the individual fuzzy order relations. Thus the global fuzzy relation contains the information about all objective functions and in the last step we find a maximum in the set of constrains with respect to the global fuzzy order relation. We illustrate this approach by an example.
Le commis voyageur allemand : une image mythifiée dans la France de 1900
Authors: Marin Séverine Antigone
Published: May 2012

Résumé Le commis voyageur allemand, lancé à la conquête de marchés lointains, est une figure récurrente dans la littérature économique française au début du XX e siècle. S’appuyant sur de nombreux témoignages de consuls français mais aussi anglais, les auteurs en firent un symbole du succès commercial allemand et le modèle à imiter – au moins en partie. Or, dans le même temps, en Allemagne le commis voyageur voyait son rôle remis en cause par la multiplication des instruments de commerce qui permettait au fabricant de contrôler plus directement la conquête de nouveaux marchés. C’est ce paradoxe que l’article examine, en montrant les enjeux de la modernisation du commerce de l’époque.
Transcriptional profiling of differentially expressed genes (DEGs) in Arabidopsis thaliana following ergosterol elicitation, using ACP-DDRT-PCR
Authors: Sherwood John S. , Piater L.A.
Published: May 2012

Plante word voortdurend blootgestel aan menigte fitopatogeniese mikro-organismes wat in hulonmiddellike omgewing voorkom en het dus met die verloop van tyd ‘n komplekse ingebore immuniteitstelsel ontwikkel om hierdie patogene te herken en te bestry.
The response of the community structured diatome on endosulfan exposure: a Mesocosm approach
Authors: Osmond Steven
Published: May 2012

Diatoms in South Africa are well studied, with a substantial species databaseavailable for use in identification of species. Biomonitoring and water quality analysis using such algae is a useful tool in aquatic health research.
AMS and LC/MS analyses of SOA from the photooxidation of benzene and 1,3,5-trimethylbenzene in the presence of NOx: effects of chemical structure on SOA aging
Authors: Sato K. , Takami A. , Kato Y. , Seta T. , Fujitani Y. , Hikida T. , Shimono A. , Imamura T.
Published: May 2012

Abstract. Oxygenated organic aerosol (OOA) observed in remote areas is believed to comprise aged secondary organic aerosol (SOA); however, the reaction processes relevant to SOA chemical aging have hitherto been unclear. We recently measured the mass spectra of SOA formed from the photooxidation of aromatic hydrocarbons using an Aerodyne aerosol mass spectrometer (AMS) and reported that SOA aging is slowed with increasing number of alkyl groups in the precursor molecule. In this study, we selected benzene and 1,3,5-trimethylbenzene (TMB) as precursors to analyze SOA formed from the photooxidation of aromatic hydrocarbons in the presence of NOx using high-resolution time-of-flight AMS (H-ToF-AMS) and liquid chromatography/time-of-flight mass spectrometry (LC/TOF-MS). A van Krevelen diagram was studied using the O/C and H/C ratios obtained by H-ToF-AMS for organics present in SOA. The results showed these organics to be rich in carboxylic acids or hydroxycarbonyls and the O/C ratio of SOA formed by the reaction of 1,3,5-TMB to be lower than that for benzene. Analytical results from LC/TOF-MS showed the particulate products formed by the reaction of 1,3,5-TMB to be richer in ketocarboxylic acids than for benzene. These results indicate that SOA aging proceeds mainly by formation of carboxylic acids and that the rate of SOA aging in laboratory chambers is limited by the oxidation of ketone groups. SOA formed in laboratory chamber experiments is less oxidized than for ambient OOA, not only because the experimental duration is insufficient or the SOA mass loading in the chamber is higher than that of the atmosphere. The laboratory chamber experiments under dry conditions are not able to simulate ketocarboxylic acid photochemical oxidation in the aqueous phase. The fractions of organic peroxides to the total SOA mass were determined by iodometric spectrophotometry to be 12 ± 8% (1,3,5-TMB) and <39% (benzene). Further, it was newly found that, unlike the reaction of benzene, only very small amounts of nitrophenols are produced by the reaction of 1,3,5-TMB.
Sensitivity studies of dust ice nuclei effect on cirrus clouds with the Community Atmosphere Model CAM5
Authors: Liu X. , Shi X. , Zhang K. , Jensen E. J. , Gettelman A. , Barahona D. , Nenes A. , Lawson P.
Published: May 2012

Abstract. In this study the effect of dust aerosol on upper tropospheric cirrus clouds through heterogeneous ice nucleation is investigated in the Community Atmospheric Model version 5 (CAM5) with two ice nucleation parameterizations. Both parameterizations consider homogeneous and heterogeneous nucleation and the competition between the two mechanisms in cirrus clouds, but differ significantly in the number concentration of heterogeneous ice nuclei (IN) from dust. Heterogeneous nucleation on dust aerosol reduces the occurrence frequency of homogeneous nucleation and thus the ice crystal number concentration in the Northern Hemisphere (NH) cirrus clouds compared to simulations with pure homogeneous nucleation. Global and annual mean shortwave and longwave cloud forcing are reduced by up to 2 W m−2 due to the presence of dust IN, with the net cloud forcing change of −0.2 to −0.4 W m−2 (cooling). Comparison of model simulations with in situ aircraft data obtained in NH mid-latitudes suggests that homogeneous ice nucleation may play an important role in the ice nucleation at these regions with temperatures of 205–230 K. However, simulations overestimate observed ice crystal number concentrations in the tropical tropopause regions with temperatures of 190–205 K, and overestimate the frequency of occurrence of high ice crystal number concentration (>200 l−1) and underestimate the frequency of low ice crystal number concentration (<30 l−1) at NH mid-latitudes. These results highlight the importance of quantifying the number concentrations and properties of heterogeneous IN (including dust aerosol) in the upper troposphere from the global perspective.
On the relationship between total ozone and atmospheric dynamics and chemistry at mid-latitudes – Part 1: Statistical models and spatial fingerprints of atmospheric dynamics and chemistry
Authors: Frossard L. , Rieder H. E. , Ribatet M. , Staehelin J. , Maeder J. A. , Di Rocco S. , Davison A. C. , Peter T.
Published: May 2012

Abstract. We use models for mean and extreme values of total column ozone on spatial scales to analyze "fingerprints" of atmospheric dynamics and chemistry on long-term ozone changes at northern and southern mid-latitudes. The r-largest order statistics method is used for pointwise analysis of extreme events in low and high total ozone (termed ELOs and EHOs, respectively). For the corresponding mean value analysis a pointwise autoregressive moving average model (ARMA) is used. The statistical models include important atmospheric covariates to describe the dynamical and chemical state of the atmosphere: the solar cycle, the Quasi-Biennial Oscillation (QBO), ozone depleting substances (ODS) in terms of equivalent effective stratospheric chlorine (EESC), the North Atlantic Oscillation (NAO), the Antarctic Oscillation (AAO), the El~Niño/Southern Oscillation (ENSO), and aerosol load after the volcanic eruptions of El Chichón and Mt. Pinatubo. The influence of the individual covariates on mean and extreme levels in total column ozone is derived on a grid cell basis. The results show that "fingerprints", i.e., significant influence, of dynamical and chemical features are captured in both the "bulk" and the tails of the ozone distribution, respectively described by means and EHOs/ELOs. While results for the solar cycle, QBO and EESC are in good agreement with findings of earlier studies, unprecedented spatial fingerprints are retrieved for the dynamical covariates.
On the relationship between total ozone and atmospheric dynamics and chemistry at mid-latitudes – Part 2: The effects of the El Niño/Southern Oscillation, volcanic eruptions and contributions of atmospheric dynamics and chemistry to long-term total ozone changes
Authors: Rieder H. E. , Frossard L. , Ribatet M. , Staehelin J. , Maeder J. A. , Di Rocco S. , Davison A. C. , Peter T. , Weihs P. , Holawe F.
Published: May 2012

Abstract. We present the first spatial analysis of "fingerprints" of the El Niño/Southern Oscillation (ENSO) and atmospheric aerosol load after major volcanic eruptions (El Chichón and Mt. Pinatubo) in extreme low and high (termed ELOs and EHOs, respectively) and mean values of total ozone for the northern and southern mid-latitudes (defined as the region between 30° and 60° north and south, respectively). Significant influence on ozone extremes was found for the warm ENSO phase in both hemispheres during spring, especially towards low latitudes, indicating the enhanced ozone transport from the tropics to the extra-tropics. Further, the results confirm findings of recent work on the connection between the ENSO phase and the strength and extent of the southern ozone "collar". For the volcanic eruptions the analysis confirms findings of earlier studies for the northern mid-latitudes and gives new insights for the Southern Hemisphere. The results provide evidence that the negative effect of the eruption of El Chichón might be partly compensated by a strong warm ENSO phase in 1982–83 at southern mid-latitudes. The strong west-east gradient in the coefficient estimates for the Mt. Pinatubo eruption and the analysis of the relationship between the AAO and ENSO phase, the extent and the position of the southern ozone "collar" and the polar vortex structure provide clear evidence for a dynamical "masking" of the volcanic signal at southern mid-latitudes. The paper also analyses the contribution of atmospheric dynamics and chemistry to long-term total ozone changes. Here, quite heterogeneous results have been found on spatial scales. In general the results show that EESC and the 11-yr solar cycle can be identified as major contributors to long-term ozone changes. However, a strong contribution of dynamical features (El Niño/Southern Oscillation (ENSO), North Atlantic Oscillation (NAO), Antarctic Oscillation (AAO), Quasi-Biennial Oscillation (QBO)) to ozone variability and trends is found at a regional level. For the QBO (at 30 and 50 hPa), strong influence on total ozone variability and trends is found over large parts of the northern and southern mid-latitudes, especially towards equatorial latitudes. Strong influence of ENSO is found over the Northern and Southern Pacific, Central Europe and central southern mid-latitudes. For the NAO, strong influence on column ozone is found over Labrador/Greenland, the Eastern United States, the Euro-Atlantic Sector and Central Europe. For the NAO's southern counterpart, the AAO, strong influence on ozone variability and long-term changes is found at lower southern mid-latitudes, including the southern parts of South America and the Antarctic Peninsula, and central southern mid-latitudes.
New parameterization of dust emissions in the global atmospheric chemistry-climate model EMAC
Authors: Astitha M. , Lelieveld J. , Abdel Kader M. , Pozzer A. , de Meij A.
Published: May 2012

Abstract. Airborne desert dust influences radiative transfer, atmospheric chemistry and dynamics, as well as nutrient transport and deposition. It directly and indirectly affects climate on regional and global scales. We present two versions of a parameterization scheme to compute desert dust emissions, incorporated into the atmospheric chemistry general circulation model EMAC (ECHAM5/MESSy2.41 Atmospheric Chemistry). One uses a globally uniform soil particle size distribution, whereas the other explicitly accounts for different soil textures worldwide. We have tested these schemes and investigated the sensitivity to input parameters, using remote sensing data from the Aerosol Robotic Network (AERONET) and dust concentrations and deposition measurements from the AeroCom dust benchmark database (and others). The two schemes are shown to produce similar atmospheric dust loads in the N-African region, while they deviate in the Asian, Middle Eastern and S-American regions. The dust outflow from Africa over the Atlantic Ocean is accurately simulated by both schemes, in magnitude, location and seasonality. The modelled dust concentrations and deposition fluxes compare well with observations at (island) stations in the Atlantic Ocean and Asia, and are underestimated in the Pacific Ocean where annual means are relatively low (<1 μg m−3). The two schemes perform similarly well, even though the total annual source differs by ~50%, indicating the importance of transport and deposition processes (being the same for the two schemes). Our results emphasize the need to represent arid regions individually and explicitly in global models according to their unique land characteristics and meteorological conditions.
Carbon fluxes in the Canadian Arctic: patterns and drivers of bacterial abundance, production and respiration on the Beaufort Sea margin
Authors: Ortega-Retuerta E. , Jeffrey W. H. , Babin M. , Bélanger S. , Benner R. , Marie D. , Matsuoka A. , Raimbault P. , Joux F.
Published: May 2012

Abstract. During August 2009, measurements of bacterial abundance and nucleic acid content were made along with production and respiration in coastal waters of the Beaufort Sea (Arctic Ocean), an area influenced by the Mackenzie River inflow. The main purpose was to evaluate bacterial organic carbon processing with respect to local sources, mainly primary production and river inputs. Bacterial production and abundance generally decreased from river to offshore waters and from surface to deep waters. In contrast, the percentage of high nucleic acid bacteria was higher in deep waters rather than in surface or river waters. Statistical analyses indicated that bacterial production was primarily controlled by temperature and the availability of labile organic matter, as indicated by total dissolved amino acid concentrations. Direct comparisons of bacterial carbon demand and primary production indicated net heterotrophy was common in shelf waters. Net autotrophy was observed at stations in the Mackenzie River plume, suggesting that the carbon fixed in plume waters helped fuel net heterotrophy in the Beaufort Sea margin.
Mid-Pliocene global climate simulation with MRI-CGCM2.3: set-up and initial results of PlioMIP Experiments 1 and 2
Authors: Kamae Y. , Ueda H.
Published: May 2012

Abstract. The mid-Pliocene (3.3 to 3.0 million yr ago), a globally warm period before the Quaternary, is recently attracting attention as a new target for paleoclimate modelling and data-model synthesis. This paper reports set-ups and results of experiments proposed in Pliocene Model Intercomparison Project (PlioMIP) using a global climate model, MRI-CGCM2.3. We conducted pre-industrial and mid-Pliocene runs by using the coupled atmosphere-ocean general circulation model (AOGCM) and its atmospheric component (AGCM) for the PlioMIP Experiments 2 and 1, respectively. In addition, we conducted two types of integrations in AOGCM simulation, with and without flux adjustments on sea surface. General characteristics of differences in the simulated mid-Pliocene climate relative to the pre-industrial in the three integrations are compared. In addition, patterns of predicted mid-Pliocene biomes resulting from the three climate simulations are compared in this study. Generally, difference of simulated surface climate between AGCM and AOGCM is larger than that between the two AOGCM runs, with and without flux adjustments. The simulated climate shows different pattern between AGCM and AOGCM particularly over low latitude oceans, subtropical land regions and high latitude oceans. The AOGCM simulations do not reproduce wetter environment in the subtropics relative to the present-day, which is suggested by terrestrial proxy data. The differences between the two types of AOGCM runs are small over the land, but evident over the ocean particularly in the North Atlantic and polar regions.
Future changes in Mekong River hydrology: impact of climate change and reservoir operation on discharge
Authors: Lauri H. , de Moel H. , Ward P. J. , Räsänen T. A. , Keskinen M. , Kummu M.
Published: May 2012

Abstract. The transboundary Mekong River is facing two on-going changes that are estimated to significantly impact its hydrology and the characteristics of its exceptional flood pulse. The rapid economic development of the riparian countries has led to massive plans for hydropower construction, and the projected climate change is expected to alter the monsoon patterns and increase temperature in the basin. The aim of this study is to assess the cumulative impact of these factors on the hydrology of the Mekong within next 20–30 yr. We downscaled output of five General Circulation Models (GCMs) that were found to perform well in the Mekong region. For the simulation of reservoir operation, we used an optimisation approach to estimate the operation of multiple reservoirs, including both existing and planned hydropower reservoirs. For hydrological assessment, we used a distributed hydrological model, VMod, with a grid resolution of 5 km × 5 km. In terms of climate change's impact to hydrology, we found a high variation in the discharge results depending on which of the GCMs is used as input. The simulated change in discharge at Kratie (Cambodia) between the baseline (1982–1992) and projected time period (2032–2042) ranges from −11% to +15% for the wet season and −10% to +13% for the dry season. Our analysis also shows that the changes in discharge due to planned reservoir operations are clearly larger than those simulated due to climate change: 25–160% higher dry season flows and 5–24% lower flood peaks in Kratie. The projected cumulative impacts follow rather closely the reservoir operation impacts, with an envelope around them induced by the different GCMs. Our results thus indicate that within the coming 20–30 yr, the operation of planned hydropower reservoirs is likely to have a larger impact on the Mekong hydrograph than the impacts of climate change, particularly during the dry season. On the other hand, climate change will increase the uncertainty of the estimated hydropower impacts. Consequently, both dam planners and dam operators should pay better attention to the cumulative impacts of climate change and reservoir operation to the aquatic ecosystems, including the multibillion-dollar Mekong fisheries.