bluuebunny/crossref_metadata_2025 huggingface dataset:
First results from radar profiles collected along the US-ITASE traverse from Taylor Dome to South Pole (2006–2008)
Authors: Welch Brian C. , Jacobel Robert W. , Arcone Steven A.
Published: August 2009

The 2006/07 and 2007/08 US-ITASE traverses from Taylor Dome to South Pole in East Antarctica provided opportunities to survey the subglacial and englacial environments using 3 MHz and 200MHz radar. We present first results of these new ground-based radar data. A prominent basal deformation layer indicates different ice-flow regimes for the northern and southern halves of the Byrd Glacier drainage. Buried dune stratigraphy that appears to be related to the megadunes towards the west occurs at depths of up to 1500 m. At least two new water-filled subglacial lakes were discovered, while two recently drained lakes identified from repeat ICESat surface elevation surveys appear to be devoid of water.
Spatial variation of radar-derived basal conditions on Kamb Ice Stream, West Antarctica
Authors: Jacobel Robert W. , Welch Brian C. , Osterhouse David , Pettersson Rickard , MacGregor Joseph A.
Published: August 2009

Radar profiles of bed echo intensity can survey conditions at the ice–bed interface and test for the presence or absence of water. However, extracting information about basal conditions from bed echo intensities requires an estimate of the attenuation loss through the ice. We used the relationship between bed echo intensities from constant-offset radar data and ice thickness to estimate depth-averaged attenuation rates at several locations on and near Kamb Ice Stream (KIS), West Antarctica. We found values varying from 29 dBkm–1at Siple Dome to 15 dBkm–1in the main trunk region of KIS, in agreement with a previous measurement and models. Using these attenuation-rate values, we calculated the relative bed reflectivity throughout our KIS surveys and found that most of the bed in the trunk has high basal reflectivities, similar to those obtained in the location of boreholes that found water at the bed. Areas of lower bed reflectivity are limited to the sticky spot, where a borehole found a dry bed, and along the margins of KIS. These results support previous hypotheses that the basal conditions at locations like the sticky spot on KIS control its stagnation and possible reactivation.
Past and present accumulation rate reconstruction along the Dome Fuji–Kohnen radio-echo sounding profile, Dronning Maud Land, East Antarctica
Authors: Huybrechts Philippe , Rybak Oleg , Steinhage Daniel , Pattyn Frank
Published: August 2009

We used internal ice layers from a radio-echo sounding profile between the Kohnen and Dome Fuji deep drilling sites to infer the spatio-temporal pattern of accumulation rate in this sector of Dronning Maud Land, East Antarctica. Continuous internal reflection horizons can be traced to about half of the ice thickness and have a maximum age of approximately 72.7 ka BP. To infer palaeo-accumulation rates from the dated layers, we derived the thinning functions from a flow calculation with a high-resolution higher-order model of Dronning Maud Land embedded into a three-dimensional thermomechanical model of the Antarctic ice sheet. The method takes into account complex ice-flow dynamics and advection effects that cannot be dealt with using traditional local approaches. We selected seven time intervals over which we determine the average accumulation rate and average surface temperature at the place and time of origin of the layer particles. Our results show lower accumulation rates along eastern parts of the profile for the late Holocene (0–5 ka BP) than are shown by existing maps, which had no surface control points. During the last glacial period we find a substantially lower accumulation rate than predicted by the usual approach linking palaeo-accumulation rates to the condensation temperature above the surface inversion layer. These findings were used to fine-tune the relation between accumulation rate and temperature.
Determination of total ice volume and ice-thickness distribution of two glaciers in the Hohe Tauern region, Eastern Alps, from GPR data
Authors: Binder D. , Brückl E. , Roch K.H. , Behm M. , Schöner W. , Hynek B.
Published: August 2009

Global warming is causing an apparent rapid retreat of many glaciers worldwide. In addition to mass-balance investigation, the determination and monitoring of total glacial ice volume and ice-thickness distribution are important parameters for understanding the interactions between climate and the complex glacier system. Because of spatially irregular and sparse datasets, scaling of volume and ice-thickness distribution is often a challenging problem. This study focuses on two small (<2 km2) temperate glaciers in the Hohe Tauern (Eastern Alps) region of central Austria. The period 2003–04 saw the first use of ground-penetrating radar (GPR) to determine the total ice volume and ice-thickness distribution of the two glaciers. A centre frequency of 20 MHz was used in point measuring mode. Despite variable data quality, bedrock reflections up to depths of >100m were identified in the data. The acquired GPR data are irregularly distributed and the spatial density is too low to calculate reasonable bedrock topography with standard interpolation approaches. Thus one main focus of this study was to develop an appropriate interpolation technique. Eventually, kriging technique and a glacial mechanically based interpolation parameter were used. Mean calculated ice thicknesses for the two investigated glaciers are 40–50 m, with a maximum of 150–165 m. No direct validation data are available, so different considerations support the computed bedrock topography.
GPR reflection profiles of Clark and Commonwealth Glaciers, Dry Valleys, Antarctica
Authors: Arcone Steven A. , Kreutz Karl
Published: August 2009

Englacial horizons deeper than 100m are absent within 100MHz ground-penetrating radar (GPR) surface profiles we recorded on Clark and Commonwealth Glaciers in the Antarctic Dry Valleys region. Both glaciers show continuous bottom horizons to 280 m, with bottom signal-to-noise ratios near 30 dB. Density horizons should fade below 50 m depth because impermeable ice occurred by 36 m. Folding within Commonwealth Glacier could preclude radar strata beneath about 80 m depth, but there is no significant folding within Clark Glacier. Strong sulfate concentrations and contrasts exist in our shallow ice core. However, it appears that high background concentration levels, and possible decreased concentration contrasts with depth placed their corresponding reflection coefficients at the limit of, or below, our system sensitivity by about 77m depth. Further verification of this conclusion awaits processing of our deep-core chemistry profiles.
Continuous profiles of electromagnetic wave velocity and water content in glaciers: an example from Bench Glacier, Alaska, USA
Authors: Bradford John H. , Nichols Joshua , Mikesell T. Dylan , Harper Joel T.
Published: August 2009

We conducted two-dimensional continuous multi-offset georadar surveys on Bench Glacier, south-central Alaska, USA, to measure the distribution of englacial water. We acquired data with a multichannel 25 MHz radar system using transmitter–receiver offsets ranging from 5 to 150 m. We towed the radar system at 5–10 kmh–1 with a snow machine with transmitter/receiver positions established by geodetic-grade kinematic differentially corrected GPS (nominal 0.5 m trace spacing). For radar velocity analyses, we employed reflection tomography in the pre-stack depth-migrated domain to attain an estimated 2% velocity uncertainty when averaged over three to five wavelengths. We estimated water content from the velocity structure using the complex refractive index method equation and use a three-phase model (ice, water, air) that accounts for compression of air bubbles as a function of depth. Our analysis produced laterally continuous profiles of glacier water content over several kilometers. These profiles show a laterally variable, stratified velocity structure with a low-water-content (~0–0.5%) shallow layer (~20–30 m) underlain by high-water-content (1–2.5%) ice.
Bed properties and hydrological conditions underneath McCall Glacier, Alaska, USA
Authors: Pattyn Frank , Delcourt Charlotte , Samyn Denis , de Smedt Bert , Nolan Matt
Published: August 2009

During three summer field seasons (2003, 2005 and 2006) we carried out radio-echo sounding measurements with a 5MHz (central frequency) ice-penetrating radar on McCall Glacier, Arctic Alaska, USA, along the central flowline and 17 cross-profiles. Two-way travel time was, after migration, converted to ice thickness, which, in combination with a recent digital elevation model of the surface of the glaciated area, resulted in a detailed map of the bed topography. This reveals a complex basal topography in the confluence area of the different glacial cirques. The pattern of subglacial water flow following the hydraulic potential gradient was calculated for the whole glacier area and shows a confluence of subglacial water downstream from the confluence of the glacier cirques. From the ice-thickness map the total ice volume was estimated as slightly less than 0.5 km3. Bed reflection power (BRP) was determined for the glacier after correction for ice-thickness dependence. Results reveal a clear relationship between the BRP pattern and basal sliding anomalies along the central flowline.
Structural controls on englacial esker sedimentation: Skeiðarárjökull, Iceland
Authors: Burke Matthew J. , Woodward John , Russell Andrew J. , Jay Fleisher P.
Published: August 2009

We have used ground-penetrating radar (GPR) to observe englacial structural control upon the development of an esker formed during a high-magnitude outburst flood (jökulhlaup). The surge-type Skeiðarárjökull, an outlet glacier of the Vatnajökull ice cap, Iceland, is a frequent source of jökulhlaups. The rising-stage waters of the November 1996 jökulhlaup travelled through a dense network of interconnected fractures that perforated the margin of the glacier. Subsequent discharge focused upon a small number of conduit outlets. Recent ice-marginal retreat has exposed a large englacial esker associated with one of these outlets. We investigated structural controls on esker genesis in April 2006, by collecting >2.5km of GPR profiles on the glacier surface up-glacier of where the esker ridge has been exposed by meltout. In lines closest to the exposed esker ridge, we interpret areas of englacial horizons up to ~30m wide and ~10–15m high as an up-glacier continuation of the esker sediments. High-amplitude, dipping horizons define the base of esker materials across many lines. Similar dipping surfaces deeper in the profiles suggest that: (1) the dipping surfaces beneath the esker are englacial tephera bands; (2) floodwaters were initially discharged along structurally controlled englacial surfaces (tephra bands); (3) the rapid increase in discharge resulted in hydrofracturing; (4) establishment of preferential flow paths resulted in conduit development along the tephra bands due to localized excavation of surrounding glacier ice; and (5) sedimentation took place within the new accommodation space to form the englacial structure melting out to produce the esker.
A new regional high-resolution map of basal and surface topography for the Greenland ice-sheet margin at Paakitsoq, West Greenland
Authors: Mottram Ruth , Nielsen Claus , Ahlstrøm Andreas P. , René Niels , Kristensen Steen S. , Christensen Erik L. , Forsberg Rene´ , Stenseng Lars
Published: August 2009

In 2005 an airborne survey was carried out from a Twin Otter aircraft at Pâkitsup Akuliarusersua (Paakitsoq) near Ilulissat in West Greenland. The survey aimed to measure ice thickness with a 60 MHz coherent radar and surface elevation with a scanning laser altimeter. Positioning information came from multiple on-board differential GPS units and an inertial navigation system. The region surveyed covers >80km along the ice margin and has a total area of ~2700km2 with varying density of measurements: the between-track distance was ~1 km near the margin, increasing to ~3km away from the margin. Regional high-resolution maps of basal topography under the Greenland ice sheet are useful for resolving important glaciological and hydrological questions and for enhancing related process studies, such as the influence of basal meltwater on ice dynamics. The ice-sheet margin in this region is also currently under consideration for hydropower development and has a long and continuing history of glaciological investigations, lately with emphasis on the connection between surface meltwater formation and surface velocity of the ice sheet. Here we present a new regional map of the surface and basal topography of the ice-sheet margin and discuss some of the implications for reported observations at Swiss Camp.
Flow dynamics of the Rutford Ice Stream ice-drainage basin, West Antarctica, from radar stratigraphy
Authors: King E.C.
Published: August 2009

Rutford Ice Stream, West Antarctica, drains a catchment of >45 000 km2into the Ronne Ice Shelf through a 26 km wide, 2.4 km deep subglacial trough adjacent to the Ellsworth Mountains. Forty-two per cent of its catchment boundary is common with Pine Island Glacier, where rapid change to ice dynamics is currently underway. These changes may eventually affect adjacent catchments such as Rutford. Radar sounding data were acquired over the Rutford ice-drainage basin that show the internal structure. In particular, distinctive reflector groups were identified that mark the boundaries between four different flow elements. The flow-margin reflector groups include curvilinear events that cross-cut isochrones and are therefore likely to be post-depositional. These reflections may arise from crystal orientation fabrics generated by localized strain in a flow margin. One of the sectors of the ice-drainage basin supplies the largest share (38%) of the ice volume flux through the main trunk of Rutford Ice Stream. This sector may be preferentially affected by continuing surface lowering in the Pine Island Glacier catchment.
Radar signatures beneath a surface topographic lineation near the outlet of Kamb Ice Stream and Engelhardt Ice Ridge, West Antarctica
Authors: Matsuoka Kenichi , Gades Anthony , Conway Howard , Catania Ginny , Raymond Charles F.
Published: August 2009

Visible and infrared satellite images reveal numerous lineations on the Siple Coast region of West Antarctica. We used 5 MHz ice-penetrating radar to probe the interior and the bed of the ice sheet beneath a lineation at the boundary between Engelhardt Ice Ridge and flat-ice terrain to the south of the Kamb Ice Stream (KIS) outlet. Results show curved reflectors that emerge from the bed beneath 600 m thick ice. The tops of the reflectors extend about 100m into the ice above the bed, where they become almost horizontal. Apparent reflectivity of the horizontal section is about 20 dB less than that of the bed. We conclude that the likely cause of such strong reflection is sea water that was accreted into basal crevasses when the flat-ice terrain was floating. Internal layers are warped downward just downslope from the basal reflectors. It is thought that the downwarping was caused by localized basal melting in the past. The spatial pattern of downwarping suggests that localized basal melting was stronger on the north side than on the south side of KIS; apparently ice/ocean interactions on the two sides of KIS were different.
Radioglaciological studies on Hurd Peninsula glaciers, Livingston Island, Antarctica
Authors: Navarro F.J. , Otero J. , Macheret Yu.Ya. , Vasilenko E.V. , Lapazaran J.J. , Ahlstrøm A.P. , Machío F.
Published: August 2009

We present the results of several radio-echo sounding surveys carried out on Johnsons and Hurd Glaciers, Livingston Island, Antarctica, between the 1999/2000 and 2004/05 austral summer campaigns, which included both radar profiling and common-midpoint measurements with low (20– 25 MHz)- and high (200 MHz)-frequency radars. The latter have allowed us to estimate the radio-wave velocity in ice and firn and the corresponding water contents in temperate ice, which vary between 0 and 1.6% depending on the zone. Maximum ice thickness is ~200 m, with a mean value of 93.6±2.5 m. Total ice volume is 0.968±0.026 km3, for an area of 10.34±0.03km2. The subglacial relief of Johnsons Glacier is quite smooth, while that of Hurd Glacier shows numerous overdeepenings and peaks. The radar records suggest that Hurd Glacier has a polythermal structure, contrary to the usual assumption that glaciers in Livingston Island are temperate. This is also supported by other dynamical and geomorphological evidence.
Deducing the thermal structure in the tongue of Gornergletscher, Switzerland, from radar surveys and borehole measurements
Authors: Eisen O. , Bauder A. , Lüthi M. , Riesen P. , Funk M.
Published: August 2009

We present the thermal distribution in the confluence area of Gorner- and Grenzgletscher, Valais, Switzerland. The area was mapped by ice-penetrating radar at 1–5 and 40 MHz. The higher-frequency data reveal a thick surface layer of low backscatter in the center of the Grenzgletscher branch. Based on datasets of borehole-temperature measurements and flow velocity, we interpret this as a thick layer of cold ice, advected from the accumulation region of Grenzgletscher. Along seven profiles the base of the low-backscatter zone can be found at a maximum depths between approximately 100 and 200 m. Laterally, the layer extends some 400 m, ∼1/3 of the width of the Grenzgletscher branch. The lower boundary of the low-backscatter zone is systematically higher than the cold–temperate transition surface found in the boreholes. This discrepancy is attributed to the direct sensitivity of radar backscatter to liquid-water inclusions, rather than to the temperature distributions as observed in boreholes. We present the current state of the cold layer and discuss its influence on other glacier characteristics.
Automated Identification of Diagnosis and Co-morbidity in Clinical Records
Authors: Cano C. , Blanco A. , Peshkin L.
Published: August 2009

Objectives: Automated understanding of clinical records is a challenging task involving various legal and technical difficulties. Clinical free text is inherently redundant, unstructured, and full of acronyms, abbreviations and domain-specific language which make it challenging to mine automatically. There is much effort in the field focused on creating specialized ontology, lexicons and heuristics based on expert knowledge of the domain. However, ad-hoc solutions poorly generalize across diseases or diagnoses. This paper presents a successful approach for a rapid prototyping of a diagnosis classifier based on a popular computational linguistics platform.

Methods: The corpus consists of several hundred of full length discharge summaries provided by Partners Healthcare. The goal is to identify a diagnosis and assign co-morbidity. Our approach is based on the rapid implementation of a logistic regression classifier using an existing toolkit: LingPipe (http://alias-i.com/lingpipe). We implement and compare three different classifiers. The baseline approach uses character 5-grams as features. The second approach uses a bag-of-words representation enriched with a small additional set of features. The third approach reduces a feature set to the most informative features according to the information content.

Results: The proposed systems achieve high performance (average F-micro 0.92) for the task. We discuss the relative merit of the three classifiers. Supplementary material with detailed results is available at: http://decsai.ugr.es/~ccano/LR/supplementary_material/

Conclusions: We show that our methodology for rapid prototyping of a domain-unaware system is effective for building an accurate classifier for clinical records.
Applicability of Lewin´s Change Management Model in a Hospital Setting
Authors: Prokosch H.-U. , Ganslandt T. , Šuc J.
Published: August 2009

Objectives: Today’s socio-economic developments in the healthcare area require continued optimization of processes and cost structures at hospitals, often associated with process changes for different occupational groups in the hospital. Formal methods for managing change have been established in other industries. The goal of this study was to assess the applicability of Kurt Lewin’s change management method to a health informatics-related project at a German university hospital.

Methods: A project at the University Hospital Erlangen introducing changed requirements in the documentation of costly material in the surgical area was conducted following the concept of Lewin’s approach based on field theory, group dynamics, action research and the three steps of change. A data warehouse contributed information to several steps in the change process.

Results: The model was successfully applied to the change project. Socio-dynamic forces relevant to the project goals were identified and considered in the design of the new documentation concept. The achieved documentation level met the new requirements and in some areas even exceeded them.

Conclusions: Based on the project experiences, we consider Kurt Lewin’s approach applicable to change management projects in the hospital sector without a requirement for substantial additional resources, however, specific hospital characteristics need to be taken into account. The data warehouse played an important role by providing essential contributions throughout the entire change process.
Automatic Brain Segmentation in Time-of-Flight MRA Images
Authors: Säring D. , Fiehler J. , Illies T. , Möller D. , Handels H. , Forkert N. D.
Published: August 2009

Objectives: Cerebral vascular malformations might, caused by ruptures, lead to strokes. The rupture risk depends to a great extent on the individual anatomy of the vasculature. The 3D Time-of-Flight (TOF) MRA technique is one of the most commonly used non-invasive imaging techniques to obtain knowledge about the individual vascular anatomy. Unfortunately TOF images exhibit drawbacks for segmentation and direct volume visualization of the vasculature. To overcome these drawbacks an initial segmentation of the brain tissue is required.

Methods: After preprocessing of the data is applied the low-intensity tissues surrounding the brain are segmented using region growing. In a following step this segmentation is used to extract supporting points at the border of the brain for a graph-based contour extraction. Finally a consistency check is performed to identify local outliers which are corrected using non-linear registration.

Results: A quantitative validation of the method proposed was performed on 18 clinical datasets based on manual segmentations. A mean Dice coefficient of 0.989 was achieved while in average 99.56% of all vessel voxels were included by the brain segmentation. A comparison to the results yielded by three commonly used tools for brain segmentation revealed that the method described achieves better results, using TOF images as input, which are within the inter-observer variability.

Conclusion: The method suggested allows a robust and automatic segmentation of brain tissue in TOF images. It is especially helpful to improve the automatic segmentation or direct volume rendering of the cerebral vascular system.
Physical Activity and Postmenopausal Breast Cancer
Authors: Schmidt M. E. , Chang-Claude J. , Slanger T. , Obi N. , Flesch-Janys D. , Steindorf K.
Published: August 2009

Objectives: Epidemiological evidence suggests an inverse association between physical activity (PA) and postmenopausal breast cancer risk. Breast cancer is a heterogeneous disease, influenced by reproductive factors, lifestyle pattern, and predispositions. We investigated whether these risk factors modify the effect of PA on breast cancer risk.

Methods: We analyzed data from 2004 hormone-receptor-positive postmenopausal breast cancer cases and 6569 controls from the population-based MARIE study conducted 2002–2005 in Germany. Interaction was statistically tested using adjusted unconditional logistic regression models.

Results: The inverse association between leisure-time PA and risk of postmenopausal hormone-receptor-positive breast cancer was not heterogeneous by family history of breast cancer or by hormone therapy. PA showed a significant interaction with benign breast diseases (p = 0.023) and with breastfeeding (p = 0.045) but not with parity (p = 0.94), with clear risk reductions only for women who ever had breastfed or who ever had a benign breast disease (among ever breastfed: odds ratio = 0.63; 95% confidence interval = (0.52, 0.77), highest vs. lowest PA quartile). Interaction with BMI was weak (p = 0.053).

Conclusions: Breastfeeding and benign breast diseases modified the effect of PA on postmenopausal breast cancer risk. If other studies find similar modifications, increasing knowledge about these risk factors may contribute to a better understanding of the mode of action of PA on breast cancer risk. For women who are at higher risk for breast cancer due to family history or due to hormone therapy use, it is encouraging that they might lower their risk by being physically active.
PROACTIVE CONTRACTING IN FINNISH PPP PROJECTS
Authors: Tieva Antti , Junnonen Juha-Matti
Published: August 2009

Public‐private‐partnership projects are long term, complex and very challenging contractual arrangements and relationships. They bring new roles for public sector and also for private sector in terms of construction and services. This paper will go through some features of the Finnish PPPs. Proactive law focuses in practical views as regards contract law and contractual issues. The main target is to prevent problems instead of confronting them. This paper will clarify what proactive law is about in terms of contract law and contracting especially in PPPs. For instance, 20–40 years’ partnership relation with PPPs brings up also dozens of different risks into the picture. This paper will discuss the risks and risk management in terms of proactive law and after that, focus on PPPs in Finland.

Santruka

Viešojo ir privataus sektoriu partnerystes (VPP) projektai ‐ tai ilgalaikiai, sude tin gi ir itin daug pastangu reikalaujantys sutartiniai susitarimai ir santykiai. Ne tik viešajame, bet ir privačiajame sektoriuje jie sukuria naujus, su statyba ir paslaugomis susijusius, vaidmenis. Šiame darbe apžvelgiami kai kurie Suomijos VPP bruožai. Iniciatyvi teise glaudžiai susijusi su prak ti nemis pažiūromis, sutarčiu teise ir pan. Pagrindinis tikslas ‐ išvengti problemu užuot jas sprendus. Šiame darbe paaiškinama iniciatyvios teises esme sudarant sutartis, ypač VPP. Pavyzdžiui, kai VPP trunka 20–40 metu, susiduriama su daugybe ivairiu rizikos rūšiu. Todel straipsnyje pirmiausia aptariamos rizikos rūšys ir rizikos valdymo būdai taikant iniciatyvia teise, o po to ‐ Suomijos VPP.
CAPACITY BUILDING LESSONS FROM A DECADE OF TRANSITIONAL SETTLEMENT AND SHELTER
Authors: Leon Esteban , Kelman Ilan , Kennedy James , Ashmore Joseph
Published: August 2009

This paper examines 23 recent case studies of post‐disaster settlement and shelter across Africa, Asia, and Latin America to provide examples of implementing transitional settlement and shelter as a process and how to build more capacity for such programmes. The case studies are examined by using a four‐part framework: (i) Safety, security, and livelihoods; (ii) the question “Transition to what?” in order to understand better how to connect post‐disaster programmes to permanent communities and housing; (iii) fairness and equity; and (iv) connecting relief and development, which also explores root causes of vulnerability. The main lessons identify six specific activities that should be highlighted for capacity building in transitional settlement and shelter: site selection, good governance, participatory and consultative processes, land ownership, logistics, and monitoring and evaluation. Santruka Šiame darbe analizuojami 23 neseniai atliktu nelaimes ištiktu žmoniu apgyvendinimo ir prieglaudu jiems suteikimo Afrikoje, Azijoje ir Lotynu Amerikoje tyrimu rezultatai, pateikiami efektyvaus aprūpinimo laikinosiomis gyvenamosiomis vietomis ir prieglaudomis programu igyvendinimo pavyzdžiai, patariama, kaip didinti šiu programu potenciala. Tyrimu rezultatai nagrinejami remiantis keturiu daliu struktūra: 1) saugumas, apsauga ir pragyvenimo šaltinis; 2) klausimas “Jei laikinas, tai kas po to?”, siekis ištikus nelaimei vykdomas apgyvendinimo programas susieti su pastoviomis bendruomenemis ir nuolatiniu būstu; 3) teisingumas ir lygybe; 4) paramos ir pletros sasaja, pagrindines pažeidžiamumo priežastys. Išskiriamos šešios konkrečios veiklos rūšys, kurias reiketu akcentuoti didinat aprūpinimo laikinosiomis gyvenamosiomis vietomis ir prieglaudu suteikimo potenciala: vietos parinkimas, geras valdymas, dalyvavimo ir konsultavimo procesai, žemes nuosavybe, logistika, stebejimas bei vertinimas.
A Case Study on Physiology-Based Drought Screening of Coconut with Selected Accessions
Authors: Nainanayake AD , Morison JIL
Published: August 2009

Recurrent droughts in Sri Lanka, now becoming increasingly frequent, cause substantial losses in coconut production. Consequently, the development of drought tolerant coconut varieties is an urgent need. Yield is the most reliable parameter to evaluate genotypes for drought tolerance but yield-based evaluation is a complex and time consuming exercise with a perennial tree crop like coconut. With the objective of identifying drought tolerant varieties, 40 coconut forms or accessions (forms/acc) in the germplasm collection at Coconut Research Institute of Sri Lanka (CRISL) have been screened. This ongoing investigation gathered information on different types of parameters, and data on a wide range of physiological parameters of adult coconut palms, during an 81-day natural drought was available, along with soil moisture readings in the manure circle. Five contrasting forms/acc (Clovis, Kasagala, Dwarf Green, Cameroon Red Dwarf, and Dwarf x Tall hybrid DT), out of the forty screened, were selected for the present case study to explore the behaviour of some important physiological functions during a drought, their relationships, and the possibility of developing a method for rapid selection of putative drought tolerant coconut palms, based on easily measurable physiological parameters. The response to drought, in terms of physiological parameters, varied in the forms/acc selected for the case study. Clovis was identified as a putative drought tolerant form/acc as it maintained a high rate of photosynthesis and water use efficiency even at the end of the dry spell. Cameroon Red Dwarf was the most drought sensitive. Kasagala showed a degree of drought tolerance, oriented towards survival, with conservation and efficient use of available soil water. However, Kasagala is not likely to be viable as a commercial crop as its low photosynthetic rate due to low stomatal conductance is indicative of low potential productivity. Drought sensitivity 1 of DT was at an intermediate level. The assimilation rate of DT was 20% higher than the mean rate of other forms/acc up to mild levels of water stress, but declined sharply when soil moisture content decreased below 15%. However, it recovers very quickly on rewetting of the soil with the onset of rains, which enables it to maintain a high overall yield. The drop in coconut production when soil water is deficient is mainly due to limitations at the stomatal level rather than at the non-stomatal (biochemical) level of the assimilation process, especially in mild to moderate drought conditions. Screening for drought tolerance based on physiological parameters appears to be rapid and promising. Nevertheless, these procedures should be further verified with long-term yield data of more forms/acc before they are widely applied. Key words: Coconut, drought tolerance, water use efficiency, photosynthesis, stomatal limitation  doi: 10.4038/cocos.v18i0.985 COCOS (2007), 18
Available Soil Phosphorus in Coconut Plantations in Boralu and Pallama Soil Series, under different Fertilizer Regimes, in Gampaha District of Sri Lanka
Authors: Jayakody JADSS , Tennakoon NA , Fernandopulle MND
Published: August 2009

Coconut plantations in the Gampaha District of Sri Lanka are generally under fertilized or not fertilized at all. The available soil phosphorus in the two major coconut growing soils in the district viz. Boralu and Pallama series, under three fertilizer regimes, organic manures, inorganic fertilizers, or no fertilizer, over the preceding five-year period, was determined and mapped. Some 32,400 ha were covered with 30 sampling locations. Leaf P content was also determined at selected sampling locations. Available P in the Boralu and Pallama soils was at a ‘medium' level of sufficiency, with a mean of 16 mg/kg, even in unfertilized coconut plantations. Leaf-P concentration in all the coconut plantations fertilized annually with inorganics, ranging from 0.135 to 0.196%, were higher than the critical leaf-P concentration (0.120%). These findings show that the available phosphorus in the two major soil series in the Gampaha District, were generally sufficient to support a healthy growth of coconut. Key Words: Available phosphorus, Boralu soil series, Coconut, Fertilizer, Pallama soil series.   doi: 10.4038/cocos.v18i0.987COCOS (2007), 18
Effect of Abscisic Acid on Survival and Recovery of Cryopreserved Plumule Explants of Coconut (Cocos nucifera)
Authors: Bandupriya HDD , Fernando SC , Verdeil J-L , Malaurie B
Published: August 2009

Cryopreservation has great potential for long-term storage of coconut genetic resources. The recent development of the encapsulation-dehydration cryogenic technique dramatically facilitated progress with cryopreservation. The present study tested the effect of abscisic acid in the encapsulationdehydration method for cryopreservation of coconut plumules. Plumules were excised from mature zygotic embryos of Coconut var. Sri Lanka Tall and encapsulated in calcium alginate. The alginate beads were used to test effect of different cryoprotection pretreatments (mixtures of 0.75 M sucrose and abscisic acid (ABA) at concentrations of 0, 10, 20 and 40 μM), and exposure to silica gel for 16 hours for further dehydration, prior to freezing in liquid nitrogen. Effect of the treatments without freezing was also tested. The water loss from alginate beads following sucrose incubation and dehydration was monitored, and the survival and growth of plumules assessed at different stages. Addition of ABA to the sucrose pretreatment medium increased the survival rate of unfrozen plumules from 60% to over 80%. Pretreatment with 40 μM ABA gave the highest survival rate (84%) of frozen plumules. The recovery rate of plumules (frozen and unfrozen) pretreated without ABA was very low (6-8%). The addition of ABA increased the recovery rate significantly; frozen plumules that had been treated with 40 μM ABA recorded a 39% recovery rate. The improved recovery could be ascribed to increased water loss (69%) in plumules treated with 40 μM ABA. Key words: Coconut, plumule, cryopreservation, abscisic acid   doi: 10.4038/cocos.v18i0.989COCOS (2007), 18
A Report on the Culture of Embryos of Dwarf Coconut, Cocos nucifera L var nana In vitro
Authors: Karunaratne Seetha , Kurukulaarachchi Cecily , Gamage Chandra
Published: August 2009

The possibility of culturing excised embryos of coconut, Cocos nucifera L. var. nana in vitro has been investigated. Embryos were excised from nuts harvested 10-11 months after pollination. Incubation of these embryos in a liquid medium (a modification of Y3 medium, Eeuwens, 1978) at 30-32°C and under a 12hr photoperiod of low light intensity (2.0μEm-2s-1) resulted in about 62% of the cultured embryos developing into seedlings. A high concentration of sucrose stimulated haustorium development and subsequent root initiation. A significant retardation in growth of the embryos and complete cessation of haustorium development and root initiation occured in the absence of activated charcoal. Four month old seedlings were transplanted successfully into soil. It is concluded that activated charcoal and a high concentration of sucrose are two important factors contributing to successful growth of coconut embryos in vitro. Attempts were also made to preserve the coconut embryos in culture in a dormant state. A special survival medium which suppresses the growth of the embryos has been developed. 32% of the embryos incubated in the survival medium for a period of 5 months developed into seedlings when transferred to the development medium.   COCOS, (1985) 3 01-08 doi: 10.4038/cocos.v3i0.815
Effect of Monocrotophos on the Leaf Eating Caterpillar, Opisina arenosella Walk, when Injected into the Trunk of the Coconut Palm
Authors: Kanagaratnam P , Pinto JLJG
Published: August 2009

Monocrotophos injected into the trunk of tall coconut palms (15 to 20 m) at 3.0 and 6.0g a.i. per palm, was translocated and accumulated in the leaves in quantities sufficient to kill the leaf eating caterpillar, Opisina arenosella. Monocrotophos was injected, as an undiluted 60% W S C , into freshly made holes, 15cm deep and 2cm in diameter, made at a point lm above the ground. Only one hole per palm was used for this treatment. Bioassays in the laboratory and assessments of the natural population of caterpillars on the experimental palms indicated that the insecticidal effect persisted in the leaves for about four to six months. This treatment would therefore be adequate to control a succession of larvae hatching out of eggs laid over a period of time. Although the injection technique obviates the risks of spray contamination of the environment, the question of pesticide residues in edible tissues arises and this aspect needs further study.    COCOS, (1985) 3 09-15 doi: 10.4038/cocos.v3i0.816
Ab initio energy calculations and macroscopic rate modeling of hydroformylation of higher alkenes by Rh‐based catalyst
Authors: Shaharun Maizatul S. , Dutta Binay K. , Mukhtar Hilmi
Published: August 2009

Ab initio quantum chemical computations have been done to determine the energetics and reaction pathways of hydroformylation of higher alkenes using a rhodium complex homogeneous catalyst. Calculation of fragments of the potential energy surfaces of the HRh(CO)(PPh3)3‐catalyzed hydroformylation of 1‐decene, 1‐dodecene, and styrene were performed by the restricted Hartree‐Fock method at the second‐order MØller‐Plesset (MP2) level of perturbation theory and basis set of 6‐31++G(d,p). Geometrically optimized structures of the intermediates and transition states were identified. Three generalized rate models were developed on the basis of above reaction path analysis as well as experimental findings reported in the literature. The kinetic and equilibrium parameters of the models were estimated by nonlinear least square regression of available literature data. The model based on H2‐oxidative addition fitted the data best; it predicts the conversion of all the alkenes quite satisfactorily with an average deviation of 7.6% and a maximum deviation of 13%. © 2009 American Institute of Chemical Engineers AIChE J, 2009
Large wave characteristics and their downstream evolution at high Reynolds number falling films
Authors: Kostoglou Margaritis , Samaras Konstantinos , Karapantsios Thodoris D.
Published: August 2009

There are many open questions regarding the evolution of waves, especially for the case of turbulent films. To resolve the complexity in modeling wavy turbulent films, more information needs to be derived from experimental data. On this account, a new way is proposed herein to analyze experimental film thickness traces, replacing the usual statistical analysis. Large waves are identified in experimental traces, and their shape is described by approximation with a few parameters curve. The probability density functions of these parameters are identified and the whole procedure can be considered as a compression method of the information content of experimental data series. By comparing results at several downstream locations, information on the evolution of waves along the flow is derived. This information indicates a 3D character of the flow, customary neglected in modeling efforts. In addition, the current results can be used for the numerical reconstruction of experimental film thickness traces. © 2009 American Institute of Chemical Engineers AIChE J, 2009
Condensed rotational separation of CO2 from natural gas
Authors: Willems G. P. , Golombok M. , Tesselaar G. , Brouwers J. J. H.
Published: August 2009

This article describes measurements of methane purification by condensed rotational separation. First, the separation concept is introduced. Then the test‐setup and measurements are described. The thermodynamic performance of the system is compared with thermodynamic predictions and is found to be in good agreement. The separation performance of the centrifugal separator is addressed. © 2009 American Institute of Chemical Engineers AIChE J, 2010
Understanding weathering of oil sands ores by atomic force microscopy
Authors: Ren Sili , Zhao Hongying , Long Jun , Xu Zhenghe , Masliyah Jacob
Published: August 2009

Effect of weathering on colloidal interactions between bitumen and oil sands solids was studied by atomic force microscopy (AFM). The change in bitumen chemistry due to weathering was found to have a negligible effect on the interactions of bitumen with solid particles. However, the increase in solid surface hydrophobicity due to ore weathering reversed the long‐range interaction forces between bitumen and solids from repulsive to attractive with a corresponding increase in adhesion force. The measured force profiles between bitumen and various solids can be well fitted with the extended DLVO theory by considering an additional attractive force. The attractive long‐range force and increased adhesion force make the separation of bitumen from solids more difficult and the attachment of fine solids on liberated bitumen easier, thereby leading to poor bitumen liberation and lower aeration efficiency. Such changes account for the observed poor processability of the weathered ores. © 2009 American Institute of Chemical Engineers AIChE J, 2009
Oxygen permeability and structural stability of a novel tantalum‐doped perovskite BaCo0.7Fe0.2Ta0.1O3−δ
Authors: Luo Huixia , Tian Bingbing , Wei Yanying , Wang Haihui , Jiang Heqing , Caro Jürgen
Published: August 2009

Dense BaCo0.7Fe0.2Ta0.1O3−δ (BCFT) perovskite membranes were successfully synthesized by a simple solid state reaction. In situ high‐temperature X‐ray diffraction indicated the good structure stability and phase reversibility of BCFT at high temperatures. The thermal expansion coefficient (TEC) of BCFT was determined to amount 1.02 × 10−5 K−1, which is smaller than those of Ba0.5Sr0.5Co0.8Fe0.2O3−δ (BSCF) (1.15 × 10−5 K−1), SrCo0.8Fe0.2O3−δ (SCF) (1.79 × 10−5 K−1), and BaCo0.4Fe0.4Zr0.2O3−δ (BCFZ) (1.03 × 10−5 K−1). It can be seen that the introduction of Ta ions into the perovskite framework could effectively lower the TEC. Thickness dependence studies of oxygen permeation through the BCFT membrane indicated that the oxygen permeation process was controlled by bulk diffusion. A membrane reactor made from BCFT was successfully operated for the partial oxidation of methane to syngas at 900°C for 400 h without failure and with the relatively high, stable oxygen permeation flux of about 16.8 ml/min cm2. © 2009 American Institute of Chemical Engineers AIChE J, 2010
Effects of shear and electrical properties on flow characteristics of pharmaceutical blends
Authors: Pingali Kalyana C. , Tomassone M. Silvina , Muzzio Fernando J.
Published: August 2009

This article examines the effects and interactions of shear rate, shear strain on electrical and flow properties of pharmaceutical blends. An unexpectedly strong relation between the flow and passive electrical properties of powders is observed to depend on the shear history of the powder bed. Charge density, impedance, dielectrophoresis, flow index, and dilation were measured for several pharmaceutical blends after they were subjected to a controlled shear environment. It was found that the increase in the shear strain intensified the electrical properties for blends that did not contain MgSt. The opposite effect was found in blends lubricated with MgSt. Different shear conditions resulted in different correlations between flow index and dilation. Flow properties of powders were found to improve with continuous exposure to shear strain. It was also found that flow properties correlated to charge acquisition and impedance for different shear treatments. © 2009 American Institute of Chemical Engineers AIChE J, 2010
Ecological correlates of infraorbital foramen area in primates
Authors: Muchlinski Magdalena N.
Published: August 2009

The infraorbital foramen (IOF) transmits the infraorbital nerve (ION) to specialized sensory cells (mechanoreceptors) in the maxillary region. The size of the IOF has been used in numerous paleoecological interpretations of the fossil record. However, these interpretations have been applied without an explicit analysis of the relationship between ecological variables and the IOF. ION and IOF cross‐sectional area show a strong positive correlation. As a result, IOF area can be a proxy for ION area, and it is hypothesized that IOF area may be a good measure for maxillary somatosensory acuity. Differences in diet, substrate preference, and/or activity pattern have been shown to correlate with differences in maxillary somatosensory acuity among mammals. This study examines how IOF area covaries with different ecological variables. IOF area was measured for 89 primate species. Ecological profiles were also created for each species and used to evaluate interspecific variation in relative IOF area within each ecological category. The results show a significant relationship between relative IOF area and diet, but not substrate preference or activity pattern. Frugivores have significantly larger relative IOFs than either folivores or insectivores, but the relative IOFs of folivores and insectivores do not differ significantly from one another. These results partially support the hypothesis that maxillary mechanoreception is a critical sensory cue for primates within a feeding context. Results for this study suggest the IOF can be used as an informative character in some paleoecological interpretations of the primate fossil record. Am J Phys Anthropol, 2010. © 2009 Wiley‐Liss, Inc.
Loss of hypocretin (orexin) neurons with traumatic brain injury
Authors: Baumann Christian R. , Bassetti Claudio L. , Valko Philipp O. , Haybaeck Johannes , Keller Morten , Clark Erika , Stocker Reto , Tolnay Markus , Scammell Thomas E.
Published: August 2009

Chronic, daytime sleepiness is a major, disabling symptom for many patients with traumatic brain injury (TBI), but thus far, its etiology is not well understood. Extensive loss of the hypothalamic neurons that produce the wake‐promoting neuropeptide hypocretin (orexin) causes the severe sleepiness of narcolepsy, and partial loss of these cells may contribute to the sleepiness of Parkinson disease and other disorders. We have found that the number of hypocretin neurons is significantly reduced in patients with severe TBI. This observation highlights the often overlooked hypothalamic injury in TBI and provides new insights into the causes of chronic sleepiness in patients with TBI. Ann Neurol 2009;66:555–559