bluuebunny/crossref_metadata_2025 huggingface dataset:
Giardiasis and Poor Vitamin A Status among Aboriginal School Children in Rural Malaysia
Authors: Al-Mekhlafi Hesham M. , Surin Johari , Sallam Atiya A. , Abdullah Ariffin W. , Mahdy Mohammed A. K.
Published: September 2010

A cross-sectional study was carried out on 241 primary schoolchildren in Pahang, Malaysia to update their vitamin A status and to investigate the association of poor vitamin A status with their health and socioeconomic factors. All children were screened for intestinal parasitic infections. Blood samples were collected and vitamin A status was assessed. Socioeconomic data were collected by using pre-tested questionnaires. The results showed that 66 (27.4%) children had low serum retinol levels (< 0.70 μmol/L). Giardiasis and severe ascariasis were significantly associated with low serum retinol levels (P = 0.004 and P = 0.018, respectively). Logistic regression confirmed the significant association of giardiasis with low serum retinol (odds ratio = 2.7, 95% confidence interval = 1.3–5.5). In conclusion, vitamin A deficiency is still a public health problem in rural Malaysia. Vitamin A supplementation and treatment of intestinal parasitic infections should be distributed periodically to these children to improve their health and nutritional status.
Nutritional Status of Children after a Food-Supplementation Program Integrated with Routine Health Care through Mobile Clinics in Migrant Communities in the Dominican Republic
Authors: Parikh Kavita , Marein-Efron Gabriela , Huang Shirley , O'Hare Geraldine , Finalle Rodney , Shah Samir S.
Published: September 2010

The objective of this study was to compare acute and chronic undernutrition rates before and after the introduction of a food-supplementation program as an adjunct to routine health care for children of migrant workers in the Dominican Republic. The cross-sectional study was conducted in five rural communities in the Dominican Republic. Children 18 years and younger were eligible if they received routine health care from local mobile clinics. Data were obtained before (2005) and after (2006) initiation of a food-supplementation program. χ2 or Fisher exact tests were used for analysis. Among 175 children in 2005, 52% were female, and 59% were < 5 years of age (mean age = 5.3 years). Among 148 children in 2006, 48% were female, and 57% were < 5 years of age (mean age = 5.6 years). Acute undernutrition rates decreased from 40% to 23% (P = 0.001) after initiation of the food-supplementation program. Rates of chronic undernutrition decreased from 33% to 18% after the initiation of the food-supplementation program (P = 0.003). Food supplementation in the context of routine health-care visits improved the nutritional status of children, and it warrants further exploration as a way to reduce childhood undernutrition in resource-scarce areas.
Implementation of a Validated Peripheral Neuropathy Screening Tool in Patients Receiving Antiretroviral Therapy in Mombasa, Kenya
Authors: Mehta Sapna A. , Ahmed Aabid , Kariuki Beatrice W. , Said Swaleh , Omasete Fanuel , Mendillo Megan , Laverty Maura , Holzman Robert , Valentine Fred , Sivapalasingam Sumathi
Published: September 2010

Limited objective data are available for the prevalence of peripheral neuropathy (PN) among antiretroviral (ART)–treated human immunodeficiency virus (HIV)–infected patients in resource-limited settings. A validated neuropathy-screening tool was integrated into routine ART visits at an HIV clinic in Mombasa, Kenya. Diagnosis of PN required at least one symptom and either abnormal vibratory sensation or deep tendon reflex bilaterally. Among 102 consecutively screened patients, 63% were women, 62% were receiving ART for ≤ 1 year, and 86% were receiving a stavudine (D4T)–based regimen. Thirty-seven (36%) had PN. Univariate analysis showed that current D4T use was protective against PN (P = 0.03) and older age was a marginal risk factor (P = 0.05). Multivariate analysis showed that older age was a risk factor for neuropathy (P = 0.04). Peripheral neuropathy was common, particularly among older HIV-infected adults in Kenya. The protective association with current D4T use likely represents survivor effect bias. Longitudinal studies using this screen will help further characterize PN in resource-limited settings.
Infectivity, Pathogenicity, and Virulence of Trypanosoma cruzi Isolates from Sylvatic Animals and Vectors, and Domestic Dogs from the United States in ICR Strain Mice and SD Strain Rats
Authors: Roellig Dawn M. , Yabsley Michael J.
Published: September 2010

Trypanosoma cruzi, the causative agent of Chagas disease, is widespread in the southern United States. In addition to detection in numerous wildlife host species, cases have been diagnosed in domestic dogs and humans. In the current investigation, groups of laboratory mice [Crl:CD1 (ICR)] were inoculated with one of 18 United States T. cruzi isolates obtained from a wide host range to elucidate their infectivity, pathogenicity, and virulence. In addition, laboratory rats (SD strain) were inoculated with four isolates. Mice and rats were susceptible to infection with all strains, but no morbidity or mortality was noted, which indicates that these T. cruzi isolates from the United States had low virulence for laboratory mice and rats.
Interannual Variability of Human Plague Occurrence in the Western United States Explained by Tropical and North Pacific Ocean Climate Variability
Authors: Ari Tamara Ben , Gershunov Alexander , Tristan Rouyer , Cazelles Bernard , Gage Kenneth , Stenseth Nils C.
Published: September 2010

Plague is a vector-borne, highly virulent zoonotic disease caused by the bacterium Yersinia pestis. It persists in nature through transmission between its hosts (wild rodents) and vectors (fleas). During epizootics, the disease expands and spills over to other host species such as humans living in or close to affected areas. Here, we investigate the effect of large-scale climate variability on the dynamics of human plague in the western United States using a 56-year time series of plague reports (1950–2005). We found that El Niño Southern Oscillation and Pacific Decadal Oscillation in combination affect the dynamics of human plague over the western United States. The underlying mechanism could involve changes in precipitation and temperatures that impact both hosts and vectors. It is suggested that snow also may play a key role, possibly through its effects on summer soil moisture, which is known to be instrumental for flea survival and development and sustained growth of vegetation for rodents.
Scaling Up Malaria Control in Zambia: Progress and Impact 2005–2008
Authors: Chizema-Kawesha Elizabeth , Miller John M. , Steketee Richard W. , Mukonka Victor M. , Mukuka Chilandu , Mohamed Abdirahman D. , Miti Simon K. , Campbell Carlos C.
Published: September 2010

Zambia national survey, administrative, health facility, and special study data were used to assess progress and impact in national malaria control between 2000 and 2008. Zambia malaria financial support expanded from US$9 million in 2003 to US$ ~40 million in 2008. High malaria prevention coverage was achieved and extended to poor and rural areas. Increasing coverage was consistent in time and location with reductions in child (age 6–59 months) parasitemia and severe anemia (53% and 68% reductions, respectively, from 2006 to 2008) and with lower post-neonatal infant and 1–4 years of age child mortality (38% and 36% reductions between 2001/2 and 2007 survey estimates). Zambia has dramatically reduced malaria transmission, disease, and child mortality burden through rapid national scale-up of effective interventions. Sustained progress toward malaria elimination will require maintaining high prevention coverage and further reducing transmission by actively searching for and treating infected people who harbor malaria parasites.
The Current Availability of Antiepileptic Drugs in Zambia: Implications for the ILAE/WHO “Out of the Shadows” Campaign
Authors: Chomba Elwyn Nachanya , Haworth Alan , Mbewe Edward , Atadzhanov Masharip , Ndubani Philimon , Kansembe Henry , Birbeck Gretchen Lano
Published: September 2010

Recent concerns regarding antiepileptic drug (AED) availability in Zambia led us to conduct a study in the Lusaka and Southern Provinces to quantify the availability and cost of AEDs and assess determinants. Among 111 pharmacies, almost one-half did not carry AEDs (N = 54; 49.1%). Available AEDs were phenobarbitone (21; 18.9%), carbamazepine (27; 24.3%), valproic acid (4; 3.6%), and phenytoin (3; 2.7%). Adult out-of-pocket monthly costs ranged from US $7 to $30. Pediatric syrups were universally unavailable. Interviews revealed several barriers to AED provision, including that handling phenobarbitone (historically the most affordable AED) has become increasingly difficult because of newly enforced regulatory requirements. Personal communications with epilepsy-care providers in other low income countries suggest that this problem may be widespread. Improved enforcement of existing drug regulations may be contributing to the AED shortage. Social programs aimed at encouraging people with epilepsy to come “out of the shadows” must be preceded by improved AED access.
A Survey of the Management, Control, and Complications of Diabetes Mellitus in Patients Attending a Diabetes Clinic in Blantyre, Malawi, an Area of High HIV Prevalence
Authors: Cohen Danielle B. , Allain Theresa J. , Glover Simon , Chimbayo Daniel , Dzamalala Helen , Hofland Helma W. C. , Banda Ndaziona P. K. , Zijlstra Eduard E.
Published: September 2010

The aim of this study was to describe the current status of diabetes care in an urban diabetes clinic in Malawi and the prevalence of human immunodeficiency virus (HIV) in this population, investigating possible associations between HIV and diabetes. A systematic prospective survey of patients attending the diabetes clinic at a teaching hospital in Blantyre, Malawi was conducted. Six hundred twenty patients were assessed. Seventy-four percent had glycosylated hemoglobin (HbA1C) > 7.5%. Systolic blood pressure was > 140 mm Hg in 52% of patients. Hypertension was more common in patients with raised creatinine (P < 0.003), retinopathy (P = 0.01), and stroke (P < 0.0002). Microvascular complication rates were high, specifically nephropathy (34.7%), retinopathy (34.7%), and neuropathy (46.4%). HIV seroprevalence was 13.7%. HIV-positive subjects had a lower body mass index (BMI) and lower fasting blood sugar, and they were more likely to have albuminuria (48.0% versus 33.3%; P < 0.05). Control of glycemia and hypertension were poor, and microvascular complications were common. Nephropathy in diabetic patients may be affected by HIV status.
Transmission Dynamics of Francisella tularensis Subspecies and Clades by Nymphal Dermacentor variabilis (Acari: Ixodidae)
Authors: Reese Sara M. , Dietrich Gabrielle , Dolan Marc C. , Sheldon Sarah W. , Piesman Joseph , Petersen Jeannine M. , Eisen Rebecca J.
Published: September 2010

In the United States, the American dog tick, Dermacentor variabilis (Say) is considered an important biological vector of Francisella tularensis, the etiologic agent of tularemia. In this study, we evaluated the vector efficiency of nymphal D. variabilis infected as larvae with differing clades and subspecies (A1b, A2, and type B) of F. tularensis. In all cases, D. variabilis larvae were able to acquire, maintain, and transstadially transmit F. tularensis. Significant replication of the bacteria also occurred in infected nymphs. Transmission of F. tularensis to Swiss Webster mice was not observed with A1b, and low rates were observed with A2 (8.0%) and type B (13.5%). Negative effects on tick survivorship were also observed for A1b, A2, and type B infections. Our results provide evidence of a high fitness cost and low transmission rates during the immature stages, suggesting that D. variabilis may play a limited role in enzootic maintenance of F. tularensis.
Relationship between Nonstructural Protein 1 Detection and Plasma Virus Load in Dengue Patients
Authors: Thomas Laurent , Najioullah Fatiha , Verlaeten Olivier , Martial Jenny , Brichler Ségolène , Kaidomar Stéphane , Moravie Victor , Cabié André , Césaire Raymond
Published: September 2010

We report data from a prospective observational study performed in Martinique during a co-epidemic of dengue virus serotype 2 (DENV-2) and serotype 4 (DENV-4). Among 70 serum samples from patients with DENV-2 (n = 21) or DENV-4 (n = 49) infections, 47 (67.1%) were positive for dengue nonstructural protein 1 (NS1). Antigenemia correlated with plasma virus load and was independent of immune status and the time of sampling. Increased viremia 4–6 days after onset of illness was associated with NS1 positivity, secondary infection, and severe disease. Testing for NS1 could help identify the potentially most severely ill patients during the critical phase of dengue.
The Worksite Supportive Environments for Active Living Survey: Development and Psychometric Properties
Authors: Blunt Gina H. , Hallam Jeffrey S.
Published: September 2010

Purpose.

The purpose of this study was to develop a self-report instrument to measure perceived physical and social environmental factors in the worksite setting that are shown to influence physical activity.

Design.

Initial items were generated from a review of the literature and were sent out for peer and expert panel review. A revised questionnaire was sent to 1250 participants to determine and test the emerging factor structure.

Setting.

The instrument was tested at two worksites in the mid-South.

Participants.

Participants consisted of a random sample of regular full-time employees at the two worksites.

Measures.

Principal axis factoring with a varimax rotation was used to explore the data in the first group of participants. Confirmatory factor analysis was used to test the fit of the final model in the second group of participants. Measures used included the comparative fit index, parsimony goodness of fit index, root mean square error of approximation, and the root mean square residual.

Results.

The final analysis showed an adequate fit of the data to the hypothesized factor structure (n = 683). The instrument showed good internal consistency, temporal stability, construct reliability, and discriminant validity.

Conclusion.

The Worksite Supportive Environments for Active Living Survey is a reliable and valid tool for investigating perception of the worksite environment related to physical activity.
Particle size distributions from laboratory-scale biomass fires using fast response instruments
Authors: Hosseini S. , Li Q. , Cocker D. , Weise D. , Miller A. , Shrivastava M. , Miller J. W. , Mahalingam S. , Princevac M. , Jung H.
Published: September 2010

Abstract. Particle size distribution from biomass combustion is an important parameter as it affects air quality, climate modelling and health effects. To date, particle size distributions reported from prior studies vary not only due to difference in fuels but also difference in experimental conditions. This study aims to report characteristics of particle size distributions in well controlled repeatable lab scale biomass fires for southwestern United States fuels with focus on chaparral. The combustion laboratory at the United States Department of Agriculture-Forest Service's Fire Science Laboratory (USDA-FSL), Missoula, MT provided a repeatable combustion and dilution environment ideal for measurements. For a variety of fuels tested the major mode of particle size distribution was in the range of 29 to 52 nm, which is attributable to dilution of the fresh smoke. Comparing mass size distribution from FMPS and APS measurement 51–68% of particle mass was attributable to the particles ranging from 0.5 to 10 μm for PM10. Geometric mean diameter rapidly increased during flaming and gradually decreased during mixed and smoldering phase combustion. Most fuels produced a unimodal distribution during flaming phase and strong biomodal distribution during smoldering phase. The mode of combustion (flaming, mixed and smoldering) could be better distinguished using the slopes in MCE (Modified Combustion Efficiency) vs. geometric mean diameter than only using MCE values.
Chemical composition of ambient aerosol, ice residues and cloud droplet residues in mixed-phase clouds: single particle analysis during the Cloud and Aerosol Characterization Experiment (CLACE 6)
Authors: Kamphus M. , Ettner-Mahl M. , Klimach T. , Drewnick F. , Keller L. , Cziczo D. J. , Mertes S. , Borrmann S. , Curtius J.
Published: September 2010

Abstract. Two different single particle mass spectrometers were operated in parallel at the Swiss High Alpine Research Station Jungfraujoch (JFJ, 3580 m a.s.l.) during the Cloud and Aerosol Characterization Experiment (CLACE 6) in February and March 2007. During mixed phase cloud events ice crystals from 5–20 μm were separated from larger ice aggregates, non-activated, interstitial aerosol particles and supercooled droplets using an Ice-Counterflow Virtual Impactor (Ice-CVI). During one cloud period supercooled droplets were additionally sampled and analyzed by changing the Ice-CVI setup. The small ice particles and droplets were evaporated by injection into dry air inside the Ice-CVI. The resulting ice and droplet residues (IR and DR) were analyzed for size and composition by the two single particle mass spectrometers: a custom-built Single Particle Laser-Ablation Time-of-Flight Mass Spectrometer (SPLAT) and a commercial Aerosol Time-of-Flight Mass Spectrometer (ATOFMS, TSI Model 3800). During CLACE 6 the SPLAT instrument characterized 355 individual IR that produced a mass spectrum for at least one polarity and the ATOFMS measured 152 IR. The mass spectra were binned in classes, based on the combination of dominating substances, such as mineral dust, sulfate, potassium and elemental carbon or organic material. The derived chemical information from the ice residues is compared to the JFJ ambient aerosol that was sampled while the measurement station was out of clouds (several thousand particles analyzed by SPLAT and ATOFMS) and to the composition of the residues of supercooled cloud droplets (SPLAT: 162 cloud droplet residues analyzed, ATOFMS: 1094). The measurements showed that mineral dust was strongly enhanced in the ice particle residues. Close to all of the SPLAT spectra from ice residues did contain signatures from mineral compounds, albeit connected with varying amounts of soluble compounds. Similarly, close to all of the ATOFMS IR spectra show a mineral or metallic component. Pure sulfate and nitrate containing particles were depleted in the ice residues. Sulfate and nitrate was found to dominate the droplet residues (~90% of the particles). The results from the two different single particle mass spectrometers were generally in agreement. Differences in the results originate from several causes, such as the different wavelength of the desorption and ionisation lasers and different size-dependent particle detection efficiencies.
Near-infrared laser desorption/ionization aerosol mass spectrometry for measuring organic aerosol at atmospherically relevant aerosol mass loadings
Authors: Geddes S. , Nichols B. , Todd K. , Zahardis J. , Petrucci G. A.
Published: September 2010

Abstract. A new method, near-infrared laser desorption/ionization aerosol mass spectrometry (NIR-LDI-AMS), is described for the real time analysis of organic aerosols at atmospherically relevant total mass loadings. Particles are sampled with an aerodynamic lens onto an aluminum probe. A moderate energy NIR laser pulse at 1064 nm is directed onto the probe to vaporize and ionize particle components. Delayed pulse extraction is then used to sample the ions into a reflectron time of flight mass spectrometer for chemical analysis. The soft ionization afforded by the NIR photons results in minimal fragmentation (loss of a hydrogen atom) producing intact pseudo-molecular anions at [M-H]−. The limit of detection measured for pure oleic acid particles (geometric mean diameter and standard deviation of 180 nm and 1.3, respectively) was 140 fg (or 1.7 ng m−3 per minute sampling time). As an example of the utility of NIR-LDI-AMS to measurements of atmospheric importance, the method was applied to laboratory chamber measurements of the secondary organic aerosol formation from ozonolysis of α-pinene. High quality mass spectra were recorded with a 2-min time resolution for total aerosol mass loadings ranging from 1.5 to 8.7 μg m−3. These results demonstrate the potential of NIR-LDI-AMS to allow for more accurate measurements of the organic fraction of atmospheric particulate at realistic mass loadings. Measurements at ambient-levels of SOA mass loading are important to improve parameterizations of chamber-based SOA formation for modeling regional and global SOA fluxes and to aid in remediating the discrepancy between modeled and observed atmospheric total SOA production rates and concentrations.
Airborne DOAS limb measurements of tropospheric trace gas profiles: case study on the profile retrieval of O4 and BrO
Authors: Prados-Roman C. , Butz A. , Deutschmann T. , Dorf M. , Kritten L. , Minikin A. , Platt U. , Schlager H. , Sihler H. , Theys N. , Van Roozendael M. , Wagner T. , Pfeilsticker K.
Published: September 2010

Abstract. A novel limb scanning mini-DOAS spectrometer for the detection of UV/vis absorbing radicals (e.g., O3, BrO, IO, HONO) was deployed on the DLR-Falcon (Deutsches Zentrum für Luft- und Raumfahrt) aircraft and tested during the ASTAR 2007 campaign (Arctic Study of Tropospheric Aerosol, Clouds and Radiation) that took place at Svalbard (78° N) in spring 2007. Our main objectives during this campaign were to test the instrument, and to perform spectral and profile retrievals of tropospheric trace gases, with particular interest on investigating the distribution of halogen compounds (e.g., BrO) during the so-called ozone depletion events (ODEs). In the present work, a new method for the retrieval of vertical profiles of tropospheric trace gases from tropospheric DOAS limb observations is presented. Major challenges arise from modeling the radiative transfer in an aerosol and cloud particle loaded atmosphere, and from overcoming the lack of a priori knowledge of the targeted trace gas vertical distribution (e.g., unknown tropospheric BrO vertical distribution). Here, those challenges are tackled by a mathematical inversion of tropospheric trace gas profiles using a regularization approach constrained by a retrieved vertical profile of the aerosols extinction coefficient εM. The validity and limitations of the algorithm are tested with in situ measured εM, and with an absorber of known vertical profile (O4). The method is then used for retrieving vertical profiles of tropospheric BrO. Results indicate that, for aircraft ascent/descent observations, the limit for the BrO detection is roughly 1.5 pptv (pmol/mol), and the BrO profiles inferred from the boundary layer up to the upper troposphere and lower stratosphere have around 10 degrees of freedom. For the ASTAR 2007 deployments during ODEs, the retrieved BrO vertical profiles consistently indicate high BrO mixing ratios (~15 pptv) within the boundary layer, low BrO mixing ratios (≤1.5 pptv) in the free troposphere, occasionally enhanced BrO mixing ratios (~1.5 pptv) in the upper troposphere, and increasing BrO mixing ratios with altitude in the lowermost stratosphere. These findings are well in agreement with satellite and balloon-borne soundings of total and partial BrO atmospheric column densities.
Estimating the seismotelluric current required for observable electromagnetic ground signals
Authors: Bortnik J. , Bleier T. E. , Dunson C. , Freund F.
Published: September 2010

Abstract. We use a relatively simple model of an underground current source co-located with the earthquake hypocenter to estimate the magnitude of the seismotelluric current required to produce observable ground signatures. The Alum Rock earthquake of 31 October 2007, is used as an archetype of a typical California earthquake, and the effects of varying the ground conductivity and length of the current element are examined. Results show that for an observed 30 nT pulse at 1 Hz, the expected seismotelluric current magnitudes fall in the range ~10–100 kA. By setting the detectability threshold to 1 pT, we show that even when large values of ground conductivity are assumed, magnetic signals are readily detectable within a range of 30 km from the epicenter. When typical values of ground conductivity are assumed, the minimum current required to produce an observable signal within a 30 km range was found to be ~1 kA, which is a surprisingly low value. Furthermore, we show that deep nulls in the signal power develop in the non-cardinal directions relative to the orientation of the source current, indicating that a magnetometer station located in those regions may not observe a signal even though it is well within the detectable range. This result underscores the importance of using a network of magnetometers when searching for preseismic electromagnetic signals.
Experimental nitrogen, phosphorus, and potassium deposition decreases summer soil temperatures, water contents, and soil CO2 concentrations in a northern bog
Authors: Wendel S. , Moore T. , Bubier J. , Blodau C.
Published: September 2010

Abstract. Ombrotrophic peatlands depend on airborne nitrogen (N), whose deposition has increased in the past and lead to disappearance of mosses and increased shrub biomass in fertilization experiments. The response of soil water content, temperature, and carbon gas concentrations to increased nutrient loading is poorly known and we thus determined these data at the long-term N fertilization site Mer Bleue bog, Ontario, during a two month period in summer. Soil temperatures decreased with NPK addition in shallow peat soil primarily during the daytime (t-test, p<0.05) owing to increased shading, whereas they increased in deeper peat soil (t-test, p<0.05), probably by enhanced thermal conductivity. RMANOVA suggested interactions between N and PK addition in particular soil layers and strong interactions between soil temperatures and volumetric water contents (p<0.05). Averaged over all fertilized treatments, the mean soil temperatures at 5 cm depth decreased by 1.3 °C and by 4.7 °C (standard deviation 0.9 °C) at noon. Water content was most strongly affected by within-plot spatial heterogeneity but also responded to both N and PK load according to RMANOVA (p<0.05). Overall, water content and CO2 concentrations in the near-surface peat (t-test, p<0.05) were lower with increasing N load, suggesting more rapid soil gas exchange. The results thus suggest that changes in bog ecosystem structure with N deposition have significant ramifications for physical parameters that in turn control biogeochemical processes.
Variations in mid-latitude North Atlantic surface water properties during the mid-Brunhes (MIS 9–14) and their implications for the thermohaline circulation
Authors: Voelker A. H. L. , Rodrigues T. , Billups K. , Oppo D. , McManus J. , Stein R. , Hefter J. , Grimalt J. O.
Published: September 2010

Abstract. Stable isotope and ice-rafted debris records from three core sites in the mid-latitude North Atlantic (IODP Site U1313, MD01-2446, MD03-2699) are combined with records of ODP Sites 1056/1058 and 980 to reconstruct hydrographic conditions during the middle Pleistocene spanning Marine Isotope Stages (MIS) 9–14 (300–540 ka). Core MD03-2699 is the first high-resolution mid-Brunhes record from the North Atlantic's eastern boundary upwelling system covering the complete MIS 11c interval and MIS 13. The array of sites reflect western and eastern basin boundary current as well as north to south transect sampling of subpolar and transitional water masses and allow the reconstruction of transport pathways in the upper limb of the North Atlantic's circulation. Hydrographic conditions in the surface and deep ocean during peak interglacial MIS 9 and 11 were similar among all the sites with relative stable conditions and confirm prolonged warmth during MIS 11c also for the mid-latitudes. Sea surface temperature (SST) reconstructions further reveal that in the mid-latitude North Atlantic MIS 11c is associated with two plateaus, the younger one of which is slightly warmer. Enhanced subsurface northward heat transport in the eastern boundary current system, especially during early MIS 11c, is denoted by the presence of tropical planktic foraminifer species and raises the question how strongly it impacted the Portuguese upwelling system. Deep water ventilation at the onset of MIS 11c significantly preceded surface water ventilation. Although MIS 13 was generally colder and more variable than the younger interglacials the surface water circulation scheme was the same. The greatest differences between the sites existed during the glacial inceptions and glacials. Then a north – south trending hydrographic front separated the nearshore and offshore waters off Portugal. While offshore waters originated from the North Atlantic Current as indicated by the similarities between the records of IODP Site U1313, ODP Site 980 and MD01-2446, nearshore waters as recorded in core MD03-2699 derived from the Azores Current and thus the subtropical gyre. Except for MIS 12, Azores Current influence seems to be related to eastern boundary system dynamics and not to changes in the Atlantic overturning circulation.
A geophysical analysis of hydro-geomorphic controls within a headwater wetland in a granitic landscape, through ERI and IP
Authors: Riddell E. S. , Lorentz S. A. , Kotze D. C.
Published: September 2010

Abstract. Wetlands are undergoing considerable degradation in South Africa. As interventions are often technical and costly, there is a requirement to develop conceptual process models for these wetland systems so that rehabilitation attempts will be successful. This paper presents an approach using the geophysical methods of Electrical Resistivity Imaging (ERI) and Induced Polarization (IP) to delineate sub-surface hydro-geomorphic controls that maintain equilibrium disconnectivity of wetland-catchment processes, which through gully erosion are increasing the catchments connectivity through loss of water and sediment. The findings presented here give insight into the geomorphic processes that maintain the wetland in an un-degraded state, this allows for the development of a conceptual model outlining the wetland forming processes. The analysis suggests that sub-surface clay-plugs, within an otherwise sandy substrate are created by illuviation of clays from the surrounding hillslopes particularly at zones of valley confinement.
Interrill erosion, runoff and sediment size distribution as affected by slope steepness and antecedent moisture content
Authors: Defersha M. B. , Quraishi S. , Melesse A.
Published: September 2010

Abstract. Soil erosion is a two-phase process consisting of the detachment of individual particles and their transport by erosive agents such as flowing water. The rate at which erosion occurs depends upon the individual as well as interactive effects of different parameters responsible for soil erosion. The study discusses results of a laboratory analysis and evaluates the effect of slope steepness and antecedent moisture content on sediment yield (wash) and runoff rate. Interrill sediment yield, splash detachment, runoff, and sediment size distribution were measured in laboratory erosion pans under simulated total duration of 90 min. Rainfall intensity at 120 mm/hr, 70 mm/hr, and 55 mm/hr were applied sequentially at 9, 25, and 45% slope steepness for three soils (Alemaya Black soil, Regosols, and Cambisols) varied from clay to sandy clay loam in texture with wet and dry antecedent water contents. As slope steepness increased from 9 to 25% splash increased for five treatments and decreased for the remaining treatment; washed sediment increased for all treatments. As slope increased from 25 to 45% splash decreased for five treatments but increased for one treatment, and washed sediment increased for three treatments but decreased for the other three treatments. Pre-wetting decreased splash detachment for all soil treatments and rate of reduction was high for the highly aggregated soil, Alemaya Black soil and low for the less aggregated soil Regosols. Splash sediment and sediment yield was not correlated. Change in splash with increase in slope steepness was also not correlated with change in sediment yield. Change in runoff rate with increase in slope steepness was correlated (r=0.66) with change in sediment yield. For Alemaya Black soil and Regosols, splashed sediment size distribution was correlated with washed sediment size distribution. Interrill erosion models that include runoff and rainfall intensity parameters were a better fit for these data than the rainfall intensity based model. The exponent term, b, values in (E=a Ib) model did not approach 2.00 for all treatments. For the same slope steepness factor, both rainfall and rainfall-runoff based models provided different erodibility coefficients at different levels of slope and moisture contents.
State-space approach to evaluate spatial variability of field measured soil water status along a line transect in a volcanic-vesuvian soil
Authors: Comegna A. , Coppola A. , Comegna V. , Severino G. , Sommella A. , Vitale C.
Published: September 2010

Abstract. The spatial structures of soil water status, in terms of soil water content θ and tension h, had been examined on a bare volcanic soil in Ponticelli, Naples (Italy). Measurements were made in situ at 0.3 m depth on two transects consisting of 50 positions 1 m apart. The ACF and the PACF were used to identify the univariate ARMA(1,1) model for the analyzed series and the AR(1) model for the extracted signals. Relations with a state-space model are investigated and a bivariate AR(1) model fitted. The simultaneous relations between θ and h are considered and estimated.
Large-scale runoff generation – parsimonious parameterisation using high-resolution topography
Authors: Gong L. , Halldin S. , Xu C.-Y.
Published: September 2010

Abstract. World water resources have primarily been analysed by global-scale hydrological models in the last decades. Runoff generation in many of these models are based on process formulations developed at catchments scales. The division between slow runoff (baseflow) and fast runoff is primarily governed by slope and spatial distribution of effective water storage capacity, both acting a very small scales. Many hydrological models, e.g. VIC, account for the spatial storage variability in terms of statistical distributions; such models are generally proven to perform well. The statistical approaches, however, use the same runoff-generation parameters everywhere in a basin. The TOPMODEL concept, on the other hand, links the effective maximum storage capacity with real-world topography. Recent availability of global high-quality, high-resolution topographic data makes TOPMODEL attractive as a basis for a physically-based runoff-generation algorithm at large scales, even if its assumptions are not valid in flat terrain or for deep groundwater systems. We present a new runoff-generation algorithm for large-scale hydrology based on TOPMODEL concepts intended to overcome these problems. The TRG (topography-derived runoff generation) algorithm relaxes the TOPMODEL equilibrium assumption so baseflow generation is not tied to topography. TGR only uses the topographic index to distribute average storage to each topographic index class. The maximum storage capacity is proportional to the range of topographic index and is scaled by one parameter. The distribution of storage capacity within large-scale grid cells is obtained numerically through topographic analysis. The new topography-derived distribution function is then inserted into a runoff-generation framework similar VIC's. Different basin parts are parameterised by different storage capacities, and different shapes of the storage-distribution curves depend on their topographic characteristics. The TRG algorithm is driven by the HydroSHEDS dataset with a resolution of 3'' (around 90 m at the equator). The TRG algorithm was validated against the VIC algorithm in a common model framework in 3 river basins in different climates. The TRG algorithm performed equally well or marginally better than the VIC algorithm with one less parameter to be calibrated. The TRG algorithm also lacked equifinality problems and offered a realistic spatial pattern for runoff generation and evaporation.
Modeling the Nd isotopic composition in the North Atlantic basin using an eddy-permitting model
Authors: Arsouze T. , Treguier A. M. , Peronne S. , Dutay J.-C. , Lacan F. , Jeandel C.
Published: September 2010

Abstract. Boundary Exchange (BE – exchange of elements between continental margins and the open ocean) has been emphasized as a key process in the oceanic cycle of neodymium (Nd) (Lacan and Jeandel, 2005a). Here, we use a regional eddy-permitting resolution Ocean General Circulation Model (1/4°) of the North Atlantic basin to simulate the distribution of the Nd isotopic composition, considering BE as the only source. Results show good agreement with the data, confirming previous results obtained using the same parameterization of the source in a coarse resolution global model (Arsouze et al., 2007), and therefore the major control played by the BE processes in the Nd cycle on the regional scale. We quantified the exchange rate of the BE, and found that the time needed for the continental margins to significantly imprint the chemical composition of the surrounding seawater (further referred as characteristic exchange time) is of the order of 0.2 years. However, the timescale of the BE may be subject to large variations as a very short exchange time (a few days) is needed to reproduce the highly negative values of surface waters in the Labrador Sea, whereas a longer one (up to 0.5 years) is required to simulate the radiogenic influence of basaltic margins and distinguish the negative isotopic signatures of North Atlantic Deep Water from the more radiogenic southern origin water masses. This likely represents geographical variations in erosion fluxes and the subsequent particle load onto the continental margins. Although the parameterization of the BE is the same in both configurations of the model, the characteristic exchange time in the eddy-permitting configuration is significantly lower than the previous evaluations using a low resolution configuration (6 months to 10 years), but however in agreement with the available seawater Nd isotope data. This results highlights the importance of the model dynamics in simulating the BE process.
First investigations of an ice core from Eisriesenwelt cave (Austria)
Authors: May B. , Spötl C. , Wagenbach D. , Dublyansky Y. , Liebl J.
Published: September 2010

Abstract. Investigations into the genesis and dynamical properties of cave ice are essential for assessing the climate significance of these underground glaciers. We drilled an ice core through a 7.1 m thick ice body filling a large cavern of the dynamic ice cave Eisenriesenwelt (Austria). In addition to visual core inspections, quasi-continuous measurements at 2 cm resolution comprised particulate matter, stable water isotope (δ18O, δD) and electrolytic conductivity profiles supplemented by specifically selected samples analysed for tritium and radiocarbon. We found that recent ablation led to an almost complete loss of bomb derived tritium removing any ice accumulated, since at least, the early fifties leaving the actual ice surface even below the natural tritium level. The small particulate organic masses made radiocarbon dating inconclusive, though a crude estimate gave a maximum ice age in the order of several thousand years. The visual stratigraphy and all investigated parameters showed a clear dichotomy between the upper 4 m and the bottom 3 m of the core, which points to a substantial change in the ice formation process. Main features of the core comprise the changing appearance and composition of distinct cyro-calcite layers, a extremely low total ion content and a surprisingly high variability of the isotope signature. Co-isotope evaluation (δD versus δ18O) of the core in comparison with data from precipitation and karst spring water clearly indicate that ice formation is governed by (slow) freezing of dripping water.
Human Cytomegalovirus: Propagation, Quantification, and Storage
Authors: Britt William J.
Published: September 2010

Human cytomegalovirus (HCMV) is the largest and perhaps the most structurally complex member of the family of human herpesviruses. It is the prototypic virus of the β‐herpesvirus subfamily. As with other cytomegaloviruses, HCMV is exquisitely species specific and undergoes lytic replication only in cells of human origin. In addition, its replication is limited almost entirely to primary cells and a limited number of transformed cell lines. Together with its prolonged replicative cycle of ∼48 hr, the propagation and quantification of HCMV can present technical challenges. In this brief set of protocols, the propagation of laboratory strains of HCMV and their quantitation is described. In a third series of protocols, the concentration and gradient purification of HCMV for more specialized downstream applications is described. Curr. Protoc. Microbiol. 18:14E.3.1‐14E.3.17. © 2010 by John Wiley & Sons, Inc.
Thermodynamic analysis of combustion processes and pollutants emission using nonlinear optimization approach
Authors: Farshchi Tabrizi Farshad , Zolfaghari Sharak Ashkan , Zolfaghari Shahrak Arsalan
Published: September 2010

Mathematical formulation and modeling of combustion processes is an important tool in the understanding of this phenomenon. Determination of equilibrium temperature and composition is often the first stage in calculation of combustion characteristics. There are number of different techniques for simulation of combustion process. In this study a basic model has been developed based on the minimization of Gibb's free energy to simulate the combustion processes. A nonlinear mathematical optimization has been developed based on Lagrange multipliers and solved using Quasi‐Newton method written in MathCAD environment. The effect of various parameters such as initial temperature, pressure, and equivalence ratio on the equilibrium temperature and composition has been investigated. In contrast with the equilibrium constant method, obtained results out of this work show that the maximum flame temperature for normal paraffins occurs around the equivalence ratio of 1.05. In addition, from environmental point of view, effects of different conditions on the emission of pollutants in a combustion process have been studied. The simulation results showed that the NO and NO2 emission rates pass through a maximum point and there is an optimum point where the NOCO emission could be minimized. Copyright © 2010 Curtin University of Technology and John Wiley & Sons, Ltd.
Metabonomic study on women of reproductive age treated with nutritional intervention: screening potential biomarkers related to neural tube defects occurrence
Authors: Jiang Zhiting , Liang Qionglin , Wang Yong , Zheng Xiaoying , Pei Lijun , Zhang Ting , Wang Yiming , Luo Guoan
Published: September 2010

Nutritional intervention is effective in reducing the risk of neural tube defects (NTDs). To determine the effects of nutritional supplementation on human metabolism, a metabonomic study was carried out on 96 women of reproductive age. Subjects with nutritional intervention were given fortified wheat flour (containing folic acid, vitamin B1, vitamin B2, ferric sodium edetate and zinc oxide) for 8 months. Serum metabolic fingerprinting was detected via ultraperformance liquid chromatography in tandem with time‐of‐flight mass spectrometry (UPLC‐TOF MS), and data acquired was processed by multivariate statistical analysis. The result revealed a significant difference between the control and intervention group. Twenty potential biomarkers, including fructose 6‐phosphate, sphingosine 1‐phosphate, docosahexaenoic acid and hexadecanoic acid, were located and identified by the accurate mass measurement of TOF MS. These compounds are believed to be functionally related to anti‐oxidative competence in vivo. In conclusion, metabonomics study is a valuable approach in exploring the effect mechanism of nutritional intervention on NTD prevention. Copyright © 2010 John Wiley & Sons, Ltd.
Transport and binding characterization of a novel hybrid particle impregnated membrane material for bioseparations
Authors: Herigstad M. Omon , Gurgel Patrick V. , Carbonell Ruben G.
Published: September 2010

The transport and binding properties of a novel hybrid particle‐nonwoven membrane medium are described. In this construct, a polymeric chromatographic resin is entrapped between two layers of a nonwoven polypropylene membrane. The membrane‐supported resin medium offers the advantage of increased interstitial pore diameter to allow passage of cells and other debris in the feed, while providing sufficiently high surface area for product capture within the resin particles. Columns packed with PIM displayed excellent flow distribution and had interstitial porosities of 0.48 ± 0.01, 25–60% larger than those typical of a packed bed. These columns were able to pass over 95% of E. coli cells and human red blood cell concentrate in 30 column volumes while maintaining a pressure drop significantly lower than that of a packed bed with a similar amount of resin. The dynamic binding capacity of bovine serum albumin (BSA) to the chromatographic resin entrapped in the PIM packed column was essentially the same as that observed with the same volume of resin in a packed bed. The General Rate (GR) model of chromatography was used to analyze experiments indicating the breakthrough behavior of the PIM columns is predictable, and very similar to those of a normal packed bed. These results suggest that PIM constructs can be designed to process viscous mobile phases containing particulates while retaining the desirable binding characteristics of the embedded chromatographic resin and could find uses in adsorption separation processes from complex feed streams such as whole blood, cell culture, and food processing. © 2010 American Institute of Chemical Engineers Biotechnol. Prog., 2011
Nucleating the Assembly of Macromolecular Complexes
Authors: Peterson‐Kaufman Kimberly J. , Carlson Clayton D. , Rodríguez‐Martínez José A. , Ansari Aseem Z.
Published: September 2010

Nature constructs intricate complexes containing numerous binding partners in order to direct a variety of cellular processes. Researchers have taken a cue from these events to develop synthetic molecules that can nucleate natural and unnatural interactions for a diverse set of applications. These molecules can be designed to drive protein dimerization or to modulate the interactions between proteins, lipids, DNA, or RNA and thereby alter cellular pathways. A variety of components within the cellular machinery can be recruited with or replaced by synthetic compounds. Directing the formation of multicomponent complexes with new synthetic molecules can allow unprecedented control over the cellular machinery.