bluuebunny/crossref_metadata_2025_split huggingface dataset:
The enhancement of enzymatic hydrolysis of lignocellulosic substrates by the addition of accessory enzymes such as xylanase: is it an additive or synergistic effect?
Authors: Hu Jinguang , Arantes Valdeir , Saddler Jack N 
Published: October 2011

Abstract

Background
We and other workers have shown that accessory enzymes, such as β-glucosidase, xylanase, and cellulase cofactors, such as GH61, can considerably enhance the hydrolysis effectiveness of cellulase cocktails when added to pretreated lignocellulosic substrates. It is generally acknowledged that, among the several factors that hamper our current ability to attain efficient lignocellulosic biomass conversion yields at low enzyme loadings, a major problem lies in our incomplete understanding of the cooperative action of the different enzymes acting on pretreated lignocellulosic substrates.

Results
The reported work assessed the interaction between cellulase and xylanase enzymes and their potential to improve the hydrolysis efficiency of various pretreated lignocellulosic substrates when added at low protein loadings. When xylanases were added to the minimum amount of cellulase enzymes required to achieve 70% cellulose hydrolysis of steam pretreated corn stover (SPCS), or used to partially replace the equivalent cellulase dose, both approaches resulted in enhanced enzymatic hydrolysis. However, the xylanase supplementation approach increased the total protein loading required to achieve significant improvements in hydrolysis (an additive effect), whereas the partial replacement of cellulases with xylanase resulted in similar improvements in hydrolysis without increasing enzyme loading (a synergistic effect). The enhancement resulting from xylanase-aided synergism was higher when enzymes were added simultaneously at the beginning of hydrolysis. This co-hydrolysis of the xylan also influenced the gross fiber characteristics (for example, fiber swelling) resulting in increased accessibility of the cellulose to the cellulase enzymes. These apparent increases in accessibility enhanced the steam pretreated corn stover digestibility, resulting in three times faster cellulose and xylan hydrolysis, a seven-fold decrease in cellulase loading and a significant increase in the hydrolysis performance of the optimized enzyme mixture. When a similar xylanase-aided enhancement strategy was assessed on other pretreated lignocellulosic substrates, equivalent increases in hydrolysis efficiency were also observed.

Conclusions
It was apparent that the 'blocking effect' of xylan was one of the major mechanisms that limited the accessibility of the cellulase enzymes to the cellulose. However, the synergistic interaction of the xylanase and cellulase enzymes was also shown to significantly improve cellulose accessibility through increasing fiber swelling and fiber porosity and also plays a major role in enhancing enzyme accessibility.
Global discourses and experiential speculation: Secondary and tertiary graduate Malawians dissect the HIV/AIDS epidemic
Authors: Myroniuk Tyler W 
Published: October 2011

BackgroundSince the beginning of the HIV/AIDS epidemic, the perspectives of secondary and tertiary school graduates in sub‐Saharan Africa regarding the effectiveness of government and international HIV/AIDS policies and programmes have not been thoroughly examined. When extensive monetary aid is directed toward “development” in a country like Malawi, it is the educated elites ‐ secondary and tertiary graduates who are heavily involved and influential in the domestic re‐distribution and implementation of millions of dollars worth of aid ‐ on whom international expectations fall to decrease the transmission of HIV. Many Malawian jobs related to public health and HIV/AIDS are created as a direct result of this funding and are occupied by the few secondary and tertiary graduates. Thus, it is a practical venture to understand their perspectives on highly contentious and heavily funded HIV/AIDS issues that affect their nation.MethodsQualitative data was collected in this study in efforts to discover in‐depth perspectives on the HIV/AIDS epidemic. Thirty‐eight secondary and tertiary graduate Malawians took part in semi‐structured interviews. Data was analysed using an early grounded theory approach and subsequent themes of “global discourses” and “experiential knowledge of HIV/AIDS” emerged.ResultsThis group of Malawians frequently responded to questions regarding healthcare and access to medicine, sexual behaviours and methods of reducing the spread of HIV/AIDS by citing and explaining the widespread, international and “proper” responses. The secondary and tertiary graduate Malawians also discussed these same topics in terms of what they perceive or have experienced. Experiential responses, such as the counter‐productivity of circumcision and condoms, the overestimation of HIV/AIDS prevalence, and calls for more authoritarian policing of commercial sex work, were remarkably divergent from the HIV/AIDS discourse.ConclusionsThe opinions of this group of secondary and tertiary graduate Malawians do not always coincide with the current literature and policies. They give deeper insight into what is perceived and what may be taking place, and hint at what the future holds for their people. The widespread and divergent perspectives must be seriously considered because these experiences describe the potential positive and negative consequences that occur on the ground throughout Malawi as a result of HIV/AIDS policies.
Dihedral Angle Dependence of Transfer Integrals in Organic Semiconductors with Herringbone Structures
Authors: Kojima Hirotaka , Mori Takehiko 
Published: October 2011

Abstract
The herringbone structure is a representative molecular packing in organic semiconductors, but there are some modifications with largely different dihedral angles ranging from 40 to 130°. Dihedral angle θ dependence of the transfer integrals is systematically investigated on the basis of the molecular orbital calculations for various organic semiconductors including pentacene, picene, oligothiophene, fused thiophene, tetrathiafulvalenes (TTF), and benzothienobenzothiophene (BTBT). In the conventional organic semiconductors such as pentacene and oligothiophene, the transfer integral is a monotonously decreasing function of θ starting from the stacking geometry, and smaller θ provides more two-dimensional bands. When the molecules are slipped along the molecular long axis D, these compounds show characteristic oscillating structure of the transfer integrals depending on D, which is called D-modulation. Contrarily, TTF derivatives show oscillating structure of the transfer integrals depending on θ (θ-modulation) due to interaction at the side position. BTBT exhibits a pattern much different from the conventional organic semiconductors, and a considerable magnitude of transfer integrals is expected in the large θ region. These systematic investigations demonstrate that the θ-dependence of the charge transport largely depends on the original molecular orbital symmetry.
Teaching Problem Structuring Methods: Improving Understanding Through Meaningful Learning
Authors: Carreras Ashley L. , Kaur Parmjit 
Published: October 2011

This paper examines how Novak's concept (Novak, J. D. 1998. Learning, Creating and Using Knowledge: Concept Maps as Facilitative Tools in Schools and Corporations. Lawrence Erlbaum, Mahwah, NJ) of “meaningful learning” can help teachers using an “experiential” approach to teaching problem structuring methods (PSMs) help students acquire an understanding of how these methods might aid group decision making. Experiential learning is seen as a necessary foundation for the building of a student's understanding of PSMs if they are to fully appreciate the potential of the techniques. It is argued that if the affective mode of functioning (relating to moods, feelings, and attitudes) is triggered, the student is more likely to choose to engage in meaningful learning, and thereby gain an enhanced appreciation of how the methods work. An example of a causal mapping workshop is evaluated, with the findings, although limited in their validity for generalisation, pointing to a clear and direct positive link between meaningful learning and understanding by the learner.
Combustion Chemistry of the Butane Isomers in Premixed Low-Pressure Flames
Authors: Oßwald Patrick , Kohse-Höinghaus Katharina , Struckmeier Ulf , Zeuch Thomas , Seidel Lars , Leon Larisa , Mauss Fabian 
Published: October 2011

Abstract
The combustion chemistry of the two butane isomers represents a subset in a comprehensive description of C1–C4 hydrocarbon and oxygenated fuels. A critical examination of combustion models and their capability to predict emissions from this class of fuels must rely on high-quality experimental data that address the respective chemical decomposition and oxidation pathways, including quantitative intermediate species mole fractions. Premixed flat low-pressure (40 mbar) flames of the two butane isomers were thus studied under identical, fuel-rich (φ=1.71) conditions. Two independent molecular-beam mass spectrometer (MBMS) set-ups were used to provide quantitative species profiles. Both data sets, one from electron ionization (EI)-MBMS with high mass resolution and one from photoionization (PI)-MBMS with high energy resolution, are in overall good agreement. Simulations with a flame model were used to analyze the respective reaction pathways, and differences in the combustion behavior of the two isomers are discussed.
Does Increased Leaf Appearance Rate Enhance Adaptation to Postanthesis Drought Stress in Sorghum?
Authors: van Oosterom E. J. , Borrell A. K. , Deifel K. S. , Hammer G. L. 
Published: October 2011

ABSTRACTIncreased leaf appearance rate (LAR) could reduce preanthesis water use of sorghum [Sorghum bicolor (L.) Moench] by restricting plant size via reduced tillering. The aim of this paper was to assess LAR as a potential pathway for adaptation to postanthesis drought stress. Four hybrids with different LAR were grown in four semicontrolled experiments under well‐watered conditions or postanthesis drought stress and in two irrigated field experiments. Observations included leaf area dynamics, transpiration, transpiration efficiency (TE), leaf N, biomass, and grain yield. ATx642 hybrids (0.0306 leaf °C d−1) had significantly greater LAR than AQL39 hybrids (0.0279 leaf °C d−1) and this increased early main shoot vigor. Under low plant density, this reduced tiller number and hence leaf area and biomass around anthesis. As hybrids had similar TE and differed little in phenology, this can reduce preanthesis water use. Water availability at flag leaf determined grain number per plant (adjusted R2 = 0.80, p < 0.01) and hence grain yield. However, the effect of increased LAR on reduced plant size was temperature dependent. Under high temperature, genotypic differences in tillering were reduced and main shoot leaf number increased more in hybrids with greater LAR. This increased responsiveness of leaf number could increase plant size and water use at anthesis. Hence, greater LAR may confer drought adaptation only in specific environments unless it is also associated with critical aspects of biomass partitioning.
The LiP (Lifestyle in Pregnancy) Study
Authors: Vinter Christina A. , Jensen Dorte M. , Ovesen Per , Beck-Nielsen Henning , Jørgensen Jan S. 
Published: October 2011

OBJECTIVE
To study the effects of lifestyle intervention on gestational weight gain (GWG) and obstetric outcomes.

RESEARCH DESIGN AND METHODS
The LiP (Lifestyle in Pregnancy) study was a randomized controlled trial in 360 obese women allocated in early pregnancy to lifestyle intervention or control. The intervention program included dietary guidance, free membership in fitness centers, physical training, and personal coaching.

RESULTS
A total of 360 obese pregnant women were included, and 304 (84%) were followed up until delivery. The intervention group had a significantly lower median (range) GWG compared with the control group of 7.0 (4.7–10.6) vs. 8.6 kg (5.7–11.5; P = 0.01). The Institute of Medicine (IOM) recommendations on GWG were exceeded in 35.4% of women in the intervention group compared with 46.6% in the control group (P = 0.058). Overall, the obstetric outcomes between the two groups were not significantly different.

CONCLUSIONS
Lifestyle intervention in pregnancy resulted in limited GWG in obese pregnant women. Overall obstetric outcomes were similar in the two groups. Lifestyle intervention resulted in a higher adherence to the IOM weight gain recommendations; however, a significant number of women still exceeded the upper threshold.
Association Between XRCC1 ARG399GLN and P53 ARG72PRO Polymorphisms and the Risk of Gastric and Colorectal Cancer in Turkish Population
Authors: Engin Ayse , Karahalil Bensu , Karakaya Ali , Engin Atilla 
Published: October 2011

Association Between XRCC1 ARG399GLN and P53 ARG72PRO Polymorphisms and the Risk of Gastric and Colorectal Cancer in Turkish PopulationGastric cancer is one of the most common cancers of the gastrointestinal system, and its overall five-year survival rate is still 15 % to 20 %, as it can mostly be diagnosed at an advanced stage. On the other hand, although colorectal cancer has a rather good prognosis, mortality is one half that of the incidence.As carcinogenesis is believed to involve reactive radicals that cause DNA adduct formation, impaired repair activity, and weakened tumour suppression, it would help to understand the role of the polymorphisms of nucleotide excision repair enzyme XRCC1 and of tumour suppressor gene p53 in gastric and colorectal cancers. Our study included 94 gastric cancer patients, 96 colorectal cancer patients, and 108 cancer-free individuals as control with the aim to see if there was an association between XRCC1 Arg399Gln and p53 Arg72Pro polymorphisms and cancer susceptibility. DNA was extracted from peripheral blood cells and genotypes were determined using the polymerase chain reaction-restriction fragment length polymorphism. Polymorphism p53 Arg72Pro was not associated with either gastric or colorectal carcinoma, while XRCC1 Arg399Gln was not associated with the increased risk of colorectal cancer. However, XRCC1 homozygous Gln allele at codon 399 was associated with 2.54 times higher risk of gastric cancer.
Survey of Equipment Quality Control in Radiotherapy Centres in Croatia: First Results
Authors: Jurković Slaven , Diklić Ana , Kasabašić Mladen , Radojčić Đeni , Švabić Manda , Ivković Ana , Faj Dario 
Published: October 2011

Survey of Equipment Quality Control in Radiotherapy Centres in Croatia: First ResultsImplementation of advanced radiation therapy techniques in clinical practice can greatly improve tumour control and normal tissue sparing. An important part of this implementation is quality control (QC) of every part of the radiotherapy process, as it helps to detect errors and provides instant remedy. This increases the probability of successful radiation treatment and ensures patient radiation safety. Every radiotherapy quality assurance (QA) programme is based on quality control of radiotherapy equipment. The aim of our survey was to review QC practices in a number of radiotherapy centres in Croatia. As a first step, we defined a set of tests to check different parameters of linear accelerators and simulators in these centres. The tests were defined and performed according to protocols developed at two university hospitals. Test results varied largely between the centres. This calls for harmonisation of QC protocols.
Aspects of nanometer scale imaging with extreme ultraviolet (EUV) laboratory sources
Authors: Wachulak P. , Marconi M. , Isoyan A. , Urbanski L. , Bartnik A. , Fiedorowicz H. , Bartels R. 
Published: October 2011

AbstractImaging systems with nanometer resolution are instrumental to the development of the fast evolving field of nanoscience and nanotechnology. Decreasing the wavelength of illumination is a direct way to improve the spatial resolution in photon-based imaging systems and motivated a strong interest in short wavelength imaging techniques in the extreme ultraviolet (EUV) region. In this review paper, various EUV imaging techniques, such as 2D and 3D holography, EUV microscopy using Fresnel zone plates, EUV reconstruction of computer generated hologram (CGH) and generalized Talbot self-imaging will be presented utilizing both coherent and incoherent compact laboratory EUV sources. Some of the results lead to the imaging with spatial resolution reaching 50 nm in a very short exposure time. These techniques can be used in a variety of applications from actinic mask inspection in the EUV lithography, biological imaging to mask-less lithographic processes in nanofabrication.
Polyetherols from melamine cyanurate and ethylene carbobate - synthesis and application
Authors: Kijowska Dorota , Legocka Izabella 
Published: October 2011

Polyetherols from melamine cyanurate and ethylene carbobate - synthesis and application
The results of the study on the reactions of melamine cyanurate with ethylene carbonate were presented. As a result of the reactions, polyetherols containing thermostabile 1,3,5-triazine and perhyroxo-1,3,5-triazine rings in their structure were obtained. Basic physical properties such as density, viscosity, hydroxyl number, weight changes were measured. The polyetherols were applied as a polyol component to receiving of thermoresistant polyurethane foams. Some of the properties of the obtained foams were investigated. The value of the apparent density is between 51 and 71 kg/m3, compressive strength 222-356 kPa and the content of the open pores between 14-33%. Thermal resistance was also studied by means of the TGA method. It was found that oxygen index of the selected compositions is between 20-22%.
Relationships Between Vertical Jump Strength Metrics and 5 Meters Sprint Time
Authors: Marques Mário , Gil Helena , Ramos Rui , Costa Aldo , Marinho Daniel 
Published: October 2011

Relationships Between Vertical Jump Strength Metrics and 5 Meters Sprint Time
The aim of this study was to examine the relationship between short sprint time (5 m) and strength metrics of the countermovement jump (CMJ) using a linear transducer in a group of trained athletes. Twenty-five male, trained subjects volunteered to participate in the study. Each volunteer performed 3 maximal CMJ trials on a Smith machine. Peak instantaneous power was calculated by the product of velocity taken with the linear transducer. For sprint testing, each subject performed three maximum 5 m sprints. Only the best attempt was considered in both tests. Pearson product-moment correlation coefficients between 5 m sprint performance and strength metrics of the CMJ were generally positive and of clear moderate to strong magnitude (r = -0.664 to -0.801). More noticeable was the significant predictive value of bar displacement time (r= ~0.70) to sprint performance. Nevertheless, a non-significant predictive value of peak bar velocity and rate of force development measurements was found. These results underline the important relationship between 5 m sprint and maximal lower body strength, as assessed by the force, power and bar velocity displacement. It is suggested that sprinting time performance would benefit from training regimens aimed to improve these performance qualities.
The nature of the Pleistocene-Holocene palaeosols in the Gaza Strip, Palestine
Authors: Ubeid Khalid 
Published: October 2011

The nature of the Pleistocene-Holocene palaeosols in the Gaza Strip, PalestineThe Pleistocene to Holocene succession in the Gaza Strip, Palestine, consists of an alternation of calcareous sandstones and reddish fine-grained deposits (palaeosols). The palaeosols can be subdivided into two main groups based on the sand-sized versus clay- to silt-sized grains: (1) the sandy hamra palaeosols, and (2) the loess and loess-derived palaeosols. The hamra palaeosols can, in turn, also be subdivided into two main types according to their colour and grain size: (1) light brown loamy to sandy hamra palaeosols, and (2) dark brown sandy clay hamra palaeosols. The hamra palaeosols are polygenetic and originated in humid environments. Their red colour results from ferric oxides coating the sand grains, but also by illuviation. The various pedogenitic units and their gradual transition to loess palaeosols are due to different phases of dust accretion. Both groups of palaeosols developed during the last glacial. They are considered to represent different climate environments: hamra palaeosols represent humid climates, whereas the loess and loess-derived palaeosols represent dry and semi-dry climates.
Characteristics of the flow field in the combustion chamber of the internal combustion test engine
Authors: Tutak Wojciech , Jamrozik Arkadiusz 
Published: October 2011

Characteristics of the flow field in the combustion chamber of the internal combustion test engine
Results of a research study into the velocity field in combustion chamber of internal combustion engine are presented in the paper. Measurements of fresh charge flow velocity in the cylinder axis and near the cylinder squeezing surface were performed. The hot-wire anemometer was used. The measurement results were used for analysis of turbulence field in the examined combustion chamber. It turned out that in the axis of cylinder the maximum of velocity occurs 30 deg before TDC and achieves 6 m/s. In the studied combustion chamber, the maximum value of turbulence intensity was close to 0.2 and it was achieved 35 deg BTDC. Additionally, the maximal velocity dispersion in the following cycles of the researched engine was at the level of 2 m/s, which is 35% of the maximum value of flow velocity. At a point located near the squeezing surface of the piston, a similar level of turbulence, but a the smaller value of the average velocity was achieved. The turbulence field turned out to be inhomogeneous in the combustion chamber.
Snow mold fungus, Typhula ishikariensis group III, in Arctic Norway can grow at a sub-lethal temperature after freezing stress and during flooding
Authors: Hoshino T. , Tronsmo A. , Yumoto I. 
Published: October 2011

Snow mold fungus, Typhula ishikariensis group III, in Arctic Norway can grow at a sub-lethal temperature after freezing stress and during flooding
Isolates of the snow mold fungus Typhula ishikariensis group III, which is predominant in Finnmark (northern Norway) and Svalbard, are more resistant to freezing stress than group I isolates from the southern part of Norway. Group III isolates showed irregular growth on potato dextrose agar (PDA) plates when subjected to heat stress at 10°C. However, group III isolates showed relatively good growth on PDA at 10°C after freezing treatment. The optimal temperatures for mycelial growth were 5°C on PDA and 10°C in potato dextrose broth (PDB), and group III isolates showed normal mycelial growth at 10°C in PDB. Mycelium of group III isolates cultivated in water poured into PDA plates, and normal hyphal extension was observed only in the liquid media. Hyphal growth became irregular when mycelia had extended above the surface of the liquid media. These results suggested that group III isolates can grow at a sub-lethal temperature after freezing stress and during flooding. Soil freezing and thawing occurs regularly in the Arctic, and physiological characteristics of group III isolates are well adapted to climatic conditions in the Arctic.