bluuebunny/crossref_metadata_2025 huggingface dataset:
Clinical Localization of the Spasmodic Segment in Voice Limiting Pharyngoesophageal Spasm
Authors: Vishal Rao , D'Cruz Anil K , Deshpande Mandar , Chaukar Devendra , Pai Prathamesh
Published: December 2010

Background

Primary tracheoesophageal prosthetic speech is the gold standard for speech rehabilitation in patients undergoing total laryngectomy. However, despite a high success rate, the speech outcome can be suboptimal in 5-15% of these patients. The most frequent cause being hypertonicity of the pharyngoesophageal segment. We elaborate a simple clinical technique that can be performed in an outpatient clinic to identify the hypertonic pharyngoesophageal segment in patients with PES.

Methods

All these patients (13 males and 1 female) had undergone total laryngectomy and primary tracheoesophageal puncture followed by postoperative radiotherapy. Even after rigorous speech therapy, these patients had failed to develop fluent speech. The mean duration following surgery was 8 months (range 4-20 months). A simple clinical technique is elaborated utilizing the dermal ballooning effect observed in the cervical region to ascertain the site of pharyngo esophageal spasmodic segment.

Results

Using this technique we have been able to identify the hypertonic segment successfully in 13 of the 14 patients with PES. In these patients the trial lignocaine block was injected specifically at these points medial to the carotid vessels. Improvement in speech following the block was observed, and was further confirming using a videofluroscopy.

Conclusion

This technique serves as a simple and useful clinical tool to map the spasmodic segment and to guide the injection site for trial lignocaine block and as well for botulinum a toxin. In addition, it also prevents inadvertent injection to the normal segments.
CONTENT AREA READING STRATEGIES AND TEXTBOOK USE IN AGRICULTURAL EDUCATION
Authors: Park Travis D. , Osborne Ed
Published: December 2010

Increasingly, agriscience teachers are called upon to demonstrate their contributions to student achievement in math, science, and reading. This national survey of 216 agriscience teachers investigated the current attitudes and practices related to reading in agriscience. Agriscience teachers generally appreciated reading for personal development and learning, but were in less agreement about allocation of time for reading. Further, teachers agreed that reading was important in agriscience, but were in less agreement about their role in teaching content area reading strategies (CARS). Reading is a fundamental part of instruction in agriscience, with nearly 20% of class time being devoted to reading. Teachers exhibited limited knowledge of, confidence in, and frequency of CARS use. Teachers understood how to select textbooks and how to assess student comprehension. Indications suggested that teachers helped students summarize, determine important ideas, generate questions, and define unfamiliar words. However, they did not regularly help students think aloud, make predictions, use multiple strategies, activate background knowledge, preview texts, or create graphic organizers. In essence, teachers need assistance in helping students with the first two micro-periods of reading and professional development to boost knowledge, confidence, and frequency of use of content area reading strategies (CARS).
A DELPHI STUDY OF AGRICULTURAL PRACTITIONERS’ OPINIONS: NECESSARY EXPERIENCES FOR INCLUSION IN AN UNDERGRADUATE SUSTAINABLE AGRICULTURAL MAJOR
Authors: Trexler Cary J. , Parr Damian M. , Khanna Navina
Published: December 2010

This study elicited stakeholder input in the design of a University of California, Davis sustainable agriculture undergraduate major. A web-based, Delphi survey of agricultural professionals was conducted to determine what experiences practitioners thought undergraduate students should have while pursuing this degree. Through consensus, participants determined that students needed experiences in agronomic, environmental, and social aspects of agriculture. It was concluded that these students needed various skill-building experiences—both on-farm and in relationships with practitioners—to understand the agri-food system’s complexity. Practitioners suggested pedagogical approaches that challenged the status quo of single-subject, classroom-bound teaching, with holistic and interdisciplinary learning involving discussions, team projects and practical experiences. Practical experience in the field, on-farm research experiences, team projects, and guest lectures by non-faculty were among the suggested pedagogical approaches. In addition, practitioners repeatedly emphasized the need for internships, apprenticeships, student-mentor relationships, networking opportunities, and field trips that introduced students to the diversity of California agriculture. Finally, sustainable agriculture practitioners suggested that students engage in debates and discussions with stakeholders with divergent opinions about agricultural and sustainability issues. This study has implications for curriculum design in land-grant universities seeking to meaningfully engage stakeholders.
AGRISCIENCE TEACHERS’ ATTITUDES TOWARD IMPLEMENTATION OF CONTENT AREA READING STRATEGIES
Authors: Park Travis D. , Osborne Ed
Published: December 2010

As part of a larger study, four agriscience teachers were interviewed about their perceptions, attitudes, and challenges with implementing content area reading strategies (CARS) in secondary agriscience. In the larger study, two of the teachers implemented a treatment of systematic, planned, and thoughtful CARS in two agriscience courses, while the other two teachers provided the comparison of teaching their “normal” routine of instruction. Prior to the study, agriscience teachers implemented few or no CARS. They possessed limited knowledge and confidence in using CARS. However, due to pressures from administrators, the state department of education, and others, teachers in the comparison group implemented twice as many strategies as the treatment group, yet their students arrived at nearly the same level of agricultural comprehension and motivation as students in the treatment group.
FOOD LAND AND PEOPLE: CONTENT ANALYSIS AND CORRELATION TO ARKANSAS STATE STANDARDS
Authors: Powell David , Agnew David M. , McJunkin Mark
Published: December 2010

Project Food, Land, and People (FLP), is a comprehensive K-12 curriculum that teaches about the interconnectedness of the environment, food, and society. Because teachers in Arkansas need to follow state guidelines, the curriculum was correlated to the state standards, revealing a systematic, thorough integration of academic subjects with agriculture. The FLP lessons address 75% of the Student Learning Expectations (SLEs) in the Arkansas Science Framework in grades K-4 (including 100% of life science SLEs), 66% of science SLEs in grades 5-8 (including 81% of life science SLEs), and 37% of science SLEs in grades 9-12 (including 63% of life science SLEs). FLP addresses 70% of the SLEs in the Arkansas Math Frameworks in grades K4, 41% in grades 5-8, and 29% in grades 9-12. FLP addresses 69% of the SLEs in the Arkansas Social Studies Frameworks in grades K-4, 56% in grades 5-8, and 43% in grades 9-12. The FLP curriculum, consisting of 55 units, incorporates 45% of all SLEs in the Arkansas Curriculum Frameworks in all subject areas in grades K-4, 35% in grades 5-8, and 25% in grades 9-12. Documenting this connection provides justification of program appropriateness for teachers to consider in adoption and implementation of this curriculum.
THE INFLUENCE OF STUDENT LEARNING EXPERIENCE LEVEL AND LEARNING STYLE ON ACHIEVEMENT
Authors: Roberts T. Grady
Published: December 2010

An emerging trend on university campuses has been to offer courses totally online, or with a blend of online and face-to-face components. In 2002, over 80% of public universities offered both blended and online courses to their on-campus students. It is reasonable to assume that students enrolled in an online class have a different learning experience and experience the course content differently than students enrolled in a face-to-face class, recognizing that different does not necessarily imply better or worse. The purpose of this quasi-experimental study was to determine if that difference in experience with the course content affects the amount of learning for students of differing learning styles. The sample used in this study consisted of undergraduate students enrolled in an introductory food science course. The control group consisted of students enrolled in a section of the course taught with a traditional lecture (N = 253). The experimental group consisted of students enrolled in a section of the course taught asynchronously using WebCTÆ and web pages (N = 247). Results indicated no differences for Concrete Sequential, Concrete Random, and Abstract Sequential learners. A significant, but impractical difference was found for Abstract Random learners, who achieved higher in the control group.
THE INFLUENCE OF PERSONALITY TYPE ON THE EXTENT COOPERATING TEACHERS PROVIDE PSYCHOSOCIAL ASSISTANCE TO STUDENT TEACHERS
Authors: Kitchel Tracy , Torres Robert M.
Published: December 2010

The No Child Left Behind Act emphasized the need to do what university teacher preparation programs have been doing for years - look for ways to improve the development of preservice teachers. Because there are many aspects of preservice teacher preparation, research should begin at the most important aspect of such preparation. In agricultural education, literature points to student teaching being the most important aspect, particularly the student teachercooperating teacher interaction within student teaching. The purpose of the study was to determine if personality type, as measured by the Myers-Briggs Type Indicator (MBTI®), influences the psychosocial support cooperating teachers of agricultural education at the University of Missouri-Columbia and the University of Illinois at Urbana-Champaign provided their student teachers. Both student teachers and cooperating teachers are more S, T, and J, according to the MBTI®. According to both student teachers and cooperating teachers, cooperating teachers are providing psychosocial assistance to student teachers, but differently across the five psychosocial functions. Personality type was not found to be influential in predicting psychosocial assistance.
Reconciliation of measurements of hygroscopic growth and critical supersaturation of aerosol particles in central Germany
Authors: Irwin M. , Good N. , Crosier J. , Choularton T. W. , McFiggans G.
Published: December 2010

Abstract. Aerosol physical, chemical and hygroscopic properties were measured in a range of airmasses during COPS (Convective and Orographically-induced Precipitation Study) ground-based in June and July of 2007 at the Hornisgrinde mountain site in the Black Forest, Southwest Germany. Non-refractory aerosol composition was measured with an Aerosol Mass Spectrometer, simultaneous to hygroscopic growth factors at 86% relative humidity and CCN activity measurements for particles of dry (<20%) diameters 27 to 217 nm, with particle water uptake exhibiting substantial variability with time and with particle size. Variability in the measurements of hygroscopic growth factor and critical supersaturation for particles of similar sizes indicates significant compositional impact on particle water affinity. Critical supersaturation prediction using a single parameter hygroscopicity approximation derived from measured HTDMA mean growth factors deviate, beyond measurement uncertainties, from critical supersaturations derived from CCN measurements. These led to differences averaging around 35% in the number of CCN (NCCN) for the most reliable measurements depending on averaging methodology, often very much larger for individual time periods. This indicates aspects of water uptake behaviour unresolved in this experiment by the single parameter representation which, depending on its origin, may have important consequences on its generalised use.
Stratocumulus cloud thickening beneath layers of absorbing smoke aerosol
Authors: Wilcox E. M.
Published: December 2010

Abstract. Marine stratocumulus cloud properties, and the free-tropospheric environment above them, are examined in NASA A-Train satellite data for cases where smoke from seasonal burning of the West African savannah overlay the persistent southeast Atlantic stratocumulus cloud deck. CALIPSO space-borne lidar observations show that features identified as layers of aerosol occur predominantly between 2 km and 4 km. Layers identified as cloud features occur predominantly below 1.5 km altitude and beneath the layer of elevated smoke aerosol. The diurnal mean shortwave heating rates attributable to the absorption of solar energy in the aerosol layer is nearly 1.5 K d−1 for an aerosol optical thickness value of 1, and increases to 1.8 K d−1 when the smoke resides above clouds owing to the additional component of upward solar radiation reflected by the cloud. As a consequence of this heating, the 700 hPa air temperature above the cloud deck is warmer by approximately 1 K on average for cases where smoke is present above the cloud compared to cases without smoke above cloud. The warmer conditions in the free-troposphere above the cloud during smoke events coincide with cloud liquid water path values that are greater by 20 g m−2 and cloud tops that are lower for overcast conditions compared to periods with low amounts of smoke. The observed thickening and subsidence of the cloud layer are consistent with published results of large-eddy simulations showing that solar absorption by smoke above stratocumulus clouds increases the buoyancy of free-tropospheric air above the temperature inversion capping the boundary layer. Increased buoyancy inhibits the entrainment of dry air through the cloud-top, thereby helping to preserve humidity and cloud cover in the boundary layer. The direct radiative effect of absorbing aerosols residing over a bright cloud deck is a positive radiative forcing (warming) at the top of the atmosphere. However, the greater liquid water path for cases of smoke overlaying cloud contributes an additional negative semi-direct radiative forcing (cooling) of climate in locations such as the southeast Atlantic Ocean owing to the enhanced albedo of the thicker cloud.
Analysis of SAGE II ozone of the middle and upper stratosphere for its response to a decadal-scale forcing
Authors: Remsberg E. , Lingenfelser G.
Published: December 2010

Abstract. Stratospheric Aerosol and Gas Experiment (SAGE II) Version 6.2 ozone profiles are analyzed for their decadal-scale responses in the middle and upper stratosphere from September 1991 to August 2005. The profile data are averaged within twelve, 20°-wide latitude bins from 55° S to 55° N and at twelve altitudes from 27.5 to 55.0 km. The separate, 14-yr data time series are analyzed using multiple linear regression (MLR) models that include seasonal, 28 and 21-month, 11-yr sinusoid, and linear trend terms. Proxies are not used for the 28-mo (QBO-like), 11-yr solar uv-flux, or reactive chlorine terms. Instead, the present analysis focuses on the periodic 11-yr terms to see whether they are in-phase with that of a direct, uv-flux forcing or are dominated by some other decadal-scale influence. It is shown that they are in-phase over most of the latitude/altitude domain and that they have max minus min variations between 25° S and 25° N that peak near 4% between 30 and 40 km. Model simulations of the direct effects of uv-flux forcings agree with this finding. The shape of the 11-yr ozone response profile from SAGE II also agrees with that diagnosed for the stratosphere over the same time period from the HALOE data. Ozone in the middle stratosphere of the northern subtropics is perturbed during 1991−1992 following the eruption of Pinatubo, and there are pronounced decadal-scale variations in the ozone of the upper stratosphere for the northern middle latitudes presumably due to dynamical forcings. The 11-yr ozone responses of the southern hemisphere appear to be free of those extra influences. The associated linear trend terms from the SAGE II analyses are slightly negative (−2 to −4%/decade) between 35 and 45 km and nearly constant across latitude. This finding is consistent with the fact that ozone is estimated to have decreased by no more than 1.5% due to the increasing chlorine from mid-1992 to about 2000 but with little change thereafter. It is concluded that a satellite, solar occultation measurement provides both the signal sensitivity and the vertical resolution to record the stratospheric ozone response to the forcing from the solar uv-flux, as well as those due to any other long-term changes.
Influence of the calibration on experimental UV index at a midlatitude site, Granada (Spain)
Authors: Antón M. , Gil J. E. , Cazorla A. , Vilaplana J. M. , Olmo F. J. , Alados-Arboledas L.
Published: December 2010

Abstract. The ultraviolet (UV) index is the variable most commonly used to inform the general public about the levels and potential harmful effects of UV radiation incident at Earth's surface. This variable is derived from the output signal of the UV radiometers applying conversion factors obtained by calibration methods. This paper focused on the influence of the use of two of these methods (called one-step and two-steps methods) on the resulting experimental UV Index (UVI) as measured by a YES UVB-1 radiometer located in a midlatitude station, Granada (Spain) for the period 2006–2009. In addition, it is also analyzed the difference with the UVI values obtained when the calibration factors provided by the manufacturer are used. For this goal, the detailed characterization of the UVB-1 radiometer obtained in the first Spanish calibration campaign of broadband UV radiometers at the "El Arenosillo" INTA station in 2007 is used. In addition, modeled UVI data derived from the LibRadtran/UVSPEC radiative transfer code are compared with the experimental values recorded at Granada for cloud-free conditions. The absolute mean differences between the measured and modeled UVI data at Granada are around 5% using the one-step and two-steps calibration methods. This result indicates the excellent performance of these two techniques for obtaining UVI data from the UVB-1 radiometer. In contrast, the application of the calibration factor supplied by the manufacturer produces a high overestimation (~14%) of the UVI values. This fact generates unreliable alarming high UVI data in summer when the manufacturer's factor is used. Thus, days with an extreme erythemal risk (UVI higher than 10) increase up to 46% of all cases measured between May and September at Granada when the manufacturer's factor is applied. This percentage is reduced to a more reliable value of 3% when the conversion factors obtained with the two-steps calibration method are used. All these results report about the need of a sound calibration of the broadband UV instruments in order to obtain reliable measurements.
Large variability in continental shelf production of phytoplankton carbon revealed by satellite
Authors: Jönsson B. F. , Salisbury J. E. , Mahadevan A.
Published: December 2010

Abstract. We estimate the net production of phytoplankton in the Gulf of Maine (GoM) over a 3-year period using satellite ocean color data in conjunction with surface velocities from a high-resolution operational ocean circulation model. Chlorophyll (chl-a) and light attenuation (K490) products are combined with a carbon to chlorophyll model to estimate the phytoplankton carbon (PC) stock in the euphotic layer. A satellite-based productivity, termed NCPe in analogy with net community production (NCP), is derived by tracking changes in satellite-derived PC from one satellite image to the next, along water parcel trajectories calculated with surface velocities from the ocean circulation model. Such an along-trajectory analysis of satellite data discounts the effect of advection that would otherwise contribute to the temporal change between consecutive images viewed in the fixed reference frame. Our results show a high variability of up to ± 500 mg C m−2 d−1 in NCPe on spatial scales of 10–100 km. A region-wide median NCPe of 40–50 mg C m−2 d−1 is often prevalent in the Gulf, while blooms attain peak values of 400 mg C m−2 d−1 for a few days. The spatio-temporal variability of NCPe in this region, though conditioned by seasonality, is dominated by events lasting a few days, which if integrated, lead to large inter-annual variability in the annual carbon budget. This study is a step toward achieving synoptic and time-dependent estimates of oceanic productivity and NCP from satellite data.
Coupling statistically downscaled GCM outputs with a basin-lake hydrological model in subtropical South America: evaluation of the influence of large-scale precipitation changes on regional hydroclimate variability
Authors: Troin M. , Vrac M. , Khodri M. , Vallet-Coulomb C. , Piovano E. , Sylvestre F.
Published: December 2010

Abstract. We explore the reliability of large-scale climate variables, namely precipitation and temperature, as inputs for a basin-lake hydrological model in central Argentina. We used data from two regions in NCEP/NCAR reanalyses and three regions from LMDZ model simulations forced with observed sea surface temperature (HadISST) for the last 50 years. Reanalyses data cover part of the geographical area of the Sali-Dulce Basin (region A) and a zone at lower latitudes (region B). The LMDZ selected regions represent the geographical area of the Sali-Dulce Basin (box A), and two areas outside of the basin at lower latitudes (boxes B and C). A statistical downscaling method is used to connect the large-scale climate variables inferred from LMDZ and the reanalyses, with the hydrological Soil Water Assessment Tool (SWAT) model in order to simulate the Rio Sali-Dulce discharge during 1950–2005. The SWAT simulations are then used to force the water balance of Laguna Mar Chiquita, which experienced an abrupt level rise in the 1970's attributed to the increase in Rio Sali-Dulce discharge. Despite that the lowstand in the 1970's is not well reproduced in either simulation, the key hydrological cycles in the lake level are accurately captured. Even though satisfying results are obtained with the SWAT simulations using downscaled reanalyses, the lake level are more realistically simulated with the SWAT simulations using downscaled LMDZ data in boxes B and C, showing a strong climate influence from the tropics on lake level fluctuations. Our results highlight the ability of downscaled climatic data to reproduce regional climate features. Laguna Mar Chiquita can therefore be considered as an integrator of large-scale climate changes since the forcing scenarios giving best results are those relying on global climate simulations forced with observed sea surface temperature. This climate-basin-lake model is a promising approach for understanding and simulating long-term lake level variations.
The influence of changes in glacier extent and surface elevation on modeled mass balance
Authors: Paul F.
Published: December 2010

Abstract. Glaciers are widely recognized as unique demonstration objects for climate change impacts, mostly due to the strong change of glacier length in response to small climatic changes. However, glacier mass balance as the direct response to the annual atmospheric conditions can be better interpreted in meteorological terms. When the climatic signal is deduced from long-term mass balance data, changes in glacier geometry (i.e. surface extent and elevation) must be considered as such adjustments form an essential part of the glacier reaction to new climatic conditions. In this study, a set of modelling experiments is performed to assess the influence of changes in glacier geometry on mass balance for constant climatic conditions. The calculations are based on a simplified distributed energy/mass balance model in combination with information on glacier extent and surface elevation for the years 1850 and 1973/1985 for about 60 glaciers in the Swiss Alps. The results reveal that over this period about 50–70% of the glacier reaction to climate change (here a one degree increase in temperature) is "hidden" in the geometric adjustment, while only 30–50% can be measured as the long-term mean mass balance. For larger glaciers, the effect of the areal change is partly reduced by a lowered surface elevation, which results in a slightly more negative balance despite a potential increase of topographic shading. In view of several additional reinforcement feedbacks that are observed in periods of strong glacier decline, it seems that the climatic interpretation of long-term mass balance data is rather complex.
Embedding Enterprise in Biosciences
Authors: Watts Carys , Wray Katie , Kennedy Ciara , Freeman Paul , Trainer Gareth
Published: December 2010

Enterprise education at Newcastle University, UK, is embedded in the fabric of the curriculum via the Newcastle University Graduate Skills Framework. An example of this is the ‘Business for the Bioscientist’ module. The authors discuss this module with regard to good practice, enterprise development and the wider arena of graduate careers and employer expectations. The paper illustrates how a combination of academics, curriculum developers, enterprise educators and guest speakers can result in an innovative and interactive enterprise module. Feedback from employers has reinforced the importance of embedding enterprise skills in the curriculum: the authors examine the methodology used at Newcastle to achieve this, the approach adopted and responses from learners. They assess how such an initiative can establish enterprise as a norm in the skills sets of graduates. The paper proposes and highlights various factors that universities need to address if they are to realize fully the concept of entrepreneurial learning.
The Accelerating Campus Entrepreneurship (ACE) Initiative
Authors: Coleman Maébh , Hamouda Angela , Cormican Kathryn
Published: December 2010

According to the GEM Ireland Report (2009), those who have exposure to entrepreneurship education in Ireland have an increased propensity to start a new venture. The importance of entrepreneurial skills was picked up by the European Union which, in its Lisbon Strategy of March 2000, declared its objective of transforming Europe into the most competitive and dynamic knowledge-based economy in the world by 2010, and indicated that it considered entrepreneurship to be one of the ‘new basic skills’ for this knowledge-based economy. This paper examines how Irish HEIs can improve their provision of entrepreneurship education to promote positive economic growth. In particular, the authors explore the approach, process and research of the Accelerating Campus Entrepreneurship Initiative, which is a collaborative project involving five Irish HEIs aiming to produce entrepreneurial graduates in Ireland.
Delivery, Student Engagement and the Implementation of Good Practice in Entrepreneurship Education
Authors: Lam Wing
Published: December 2010

This paper presents and discusses the results of a research-informed teaching project carried out to identify key factors in the content and delivery of a successful UK government initiative, the New Entrepreneur Scholarship (NES), from 2001 to 2008. The aim of the project was to evaluate the feasibility of implementing appropriate changes to undergraduate and postgraduate entrepreneurship programmes. The findings highlight deep-rooted issues concerning entrepreneurship education and research.
What is it That Entrepreneurs Learn from Experience?
Authors: Martin Frank , Smith Ronnie
Published: December 2010

The issue of whether or not entrepreneurs really learn from experience has been one of the key themes of entrepreneurship research. If they do learn from experience, what do they learn? The importance of knowledge and learning to the performance of a business has been highlighted by many authors, who emphasize the role of life cycle, learning from mentors, experience and/or critical incidents. This paper reports on a series of interviews with mature and experienced entrepreneurs in Scotland who have been directly involved, for a substantial time, with significant business successes and failures. It is argued that prior knowledge and ongoing learning play a key role in the founder's ability to deal with the changing role they have and to acquire the necessary skills to grow the business. The crucial issue is how learning can be supported in the context of start-up and existing entrepreneurial businesses. To address this, the authors present a conceptual model made up of four elements: experience, learning, knowledge and business performance. It is concluded that entrepreneurs take time to develop their skills and need to be given the opportunity to do so if successful start-ups are to be achieved. In the main, the skills they develop in people selection and team building seem to be key determinants of their success.
Entrepreneurship Education in an Entrepreneurial Community
Authors: Hyclak Thomas , Barakat Shima
Published: December 2010

This paper examines the evolution of programmes of enterprise education and technology transfer at the University of Cambridge in response to the growth of the Cambridge Cluster and public policy programmes designed to enhance the economic impact of higher education institutions. The authors highlight the way education programmes developed by the Centre for Entrepreneurial Learning uniquely reflect the needs of nascent high-tech entrepreneurs by using local entrepreneurs, venture capitalists, angels and start-up support specialists as instructors; by gearing the curriculum to issues facing high-tech ventures; and by offering ‘extra-curricular’ programmes that fit the scheduling needs of the PhD students, post-docs and research staff who constitute the intended audience. This examination provides an interesting case study of how a mature high-tech cluster can shape university entrepreneurship programmes. It also illustrates how new educational and technology transfer programmes have pulled the university and its nascent high-tech entrepreneurs into a closer relationship with the dense network of firms and people who make up the Cambridge Cluster.
Determining Membrane Protein Topologies in Single Cells and High‐Throughput Screening Applications
Authors: Wunder Christian , Lippincott‐Schwartz Jennifer , Lorenz Holger
Published: December 2010

Correct localization and topology are crucial for a protein's cellular function. To determine topologies of membrane proteins, a new technique, called fluorescence protease protection (FPP) assay, has recently been established. The sole requirements for FPP are the expression of fluorescent‐protein fusion proteins and the selective permeabilization of the plasma membrane, permitting a wide range of cell types and organelles to be investigated. Proteins topologies in organelles like endoplasmic reticulum, Golgi apparatus, mitochondria, peroxisomes, and autophagosomes have already been determined by FPP. Here, two different step‐by‐step protocols of the FPP assay are provided. First, we describe the FPP assay using fluorescence microscopy for single adherent cells, and second, we outline the FPP assay for high‐throughput screening applications. Curr. Protoc. Cell Biol. 49:5.7.1‐5.7.12. © 2010 by John Wiley & Sons, Inc.
Measurement of Oxidatively‐Induced Clustered DNA Lesions Using a Novel Adaptation of Single Cell Gel Electrophoresis (Comet Assay)
Authors: Georgakilas Alexandros G. , Holt Stewart M. , Hair Jessica M. , Loftin Charles W.
Published: December 2010

The two basic groups of complex DNA damage are double‐strand breaks (DSBs) and non‐DSB oxidatively‐induced clustered DNA lesions (OCDLs). The single‐cell gel electrophoresis (SCGE) or comet assay has been widely used for the detection of low levels of various types of DNA lesions including single‐strand breaks (SSBs), DSBs, and oxidized bases per individual cell. There are limited data on the use of the comet assay for the detection of non‐DSB clustered DNA lesions using different repair enzymes as enzymatic probes. This unit discusses a novel adaptation of the comet assay used to measure these unique types of lesions. Until now OCDL yields have been measured using primarily pulsed‐field agarose gel electrophoresis. The advantages offered by the current approach are: (1) measurement of OCDL levels per individual cell; (2) use of a small number of cells (∼10,000) and relatively low doses of ionizing radiation (1 to 2 Gy) or low levels of oxidative stress, which are not compatible with standard agarose gel electrophoresis; and finally, (3) the assay is fast and allows direct comparison with pulsed‐field gel electrophoresis results. Curr. Protoc. Cell Biol. 47:6.11.1‐6.11.17. © 2010 by John Wiley & Sons, Inc.
Systematic Control of Nucleation Density in Poly(3‐Hexylthiophene) Thin Films
Authors: Crossland Edward J. W. , Rahimi Khosrow , Reiter Günter , Steiner Ullrich , Ludwigs Sabine
Published: December 2010

While molecular ordering via crystallization is responsible for many of the impressive optoelectronic properties of thin‐film semiconducting polymer devices, crystalline morphology and its crucial influence on performance remains poorly controlled and is usually studied as a passive result of the conditions imposed by film deposition parameters. A method for systematic control over crystalline morphology in conjugated polymer thin films by very precise control of nucleation density and crystal growth conditions is presented. A precast poly(3‐hexylthiophene) film is first swollen into a solution‐like state in well‐defined vapor pressures of a good solvent, while the physical state of the polymer chains is monitored using in situ UV–vis spectroscopy and ellipsometry. Nucleation density is selected by a controlled deswelling of the film or by a self‐seeding approach using undissolved crystalline aggregates that remain in the swollen film. Nucleation densities ranging successively over many orders of magnitude are achieved, extending into the regime of spherulitic domains 10 to 100 μm in diameter, a length scale highly relevant for typical probes of macroscopic charge transport such as field‐effect transistors. This method is presented as a tool for future systematic study of the structure‐function relation in semicrystalline semiconducting polymers in a broad range of applications.
Photoluminescence Properties of a Nearly Intrinsic Single InN Nanowire
Authors: Chang Yi‐Lu , Mi Zetian , Li Feng
Published: December 2010

In this paper, the achievement of nearly intrinsic InN nanowire is reported. With the use of an in situ deposited In seeding layer, nearly defect‐free, non‐tapered InN nanowires are grown directly on Si(111) substrates by molecular beam epitaxy. The photoluminescence emission of a single InN nanowire is analyzed, which exhibits, for the first time, a very narrow (∼13 meV) spectral linewidth, a clear band filling effect with the increase of excitation power, and a significant red shift of the peak energy with increasing temperature. Detailed analysis confirms the InN nanowire has a very low residual doping of ∼1 × 1016 cm−3, or less. It is further suggested that there is a small, or negligible level of electron accumulation at the lateral nonpolar surfaces of nearly intrinsic InN nanowires, which is in direct contrast to the commonly observed surface electron accumulation of n‐type degenerate InN.
Whole gene duplication of the PQBP1 gene in syndrome resembling Renpenning
Authors: Flynn Maureen , Zou Ying S. , Milunsky Aubrey
Published: December 2010

Renpenning syndrome is a well‐described X‐linked condition associated with multiple congenital anomalies and intellectual disability [OMIM 309500]. Typical signs include microcephaly, dysmorphic features, short stature, small testes, and lean body build. Renpenning syndrome is caused by mutations in the polyglutamine binding protein 1 (PQBP1) gene. Missense mutations, insertions, deletions, and duplications within the gene have been well‐described. We present a 47‐year‐old male with clinical features resembling Renpenning syndrome. He has moderate intellectual disability, seizures since infancy, short stature, small testes, and dysmorphic features. Of note, our patient is normocephalic. A CT scan at 14 years of age showed cerebral atrophy. He had previously been verbally communicative and had few behavioral issues. Recently, our patient has regressed and has become uncommunicative, displaying little and unclear speech. He now exhibits memory and recognition loss and is uncooperative, aggressive, self‐abusive, and incontinent. The reason for his regression within the past 4 years is unclear. SNP microarray analysis (500K) revealed a 4.7 Mb duplication at Xp11.22–p11.23. Multiple ligation probe amplification (MLPA) of the PQBP1 gene contained within this duplicated region confirmed a duplication of the entire PQBP1 gene. Multiple other genes are duplicated within this 4.7 Mb region and may contribute to his phenotype. © 2010 Wiley‐Liss, Inc.
Erzeugung sekundärer, tertiärer und quartärer Zentren durch geminale Disubstitution von Carbonyl‐Sauerstoffatomen
Authors: Seebach Dieter
Published: December 2010

Methoden zum Ersatz des Carbonylsauerstoffs durch zwei neue Substituenten (CO→CR1R2) werden beschrieben. Die Substituenten R können H, NR2, Alkyl‐, Allyl‐, Benzyl‐, Vinyl‐, Alkinyl‐, Aryl‐, Heteroaryl‐ oder Acyl‐Gruppen sein. Häufigste Ausgangsverbindungen für die geminale Disubstitution unter Bildung zweier neuer C,C‐Bindungen (R1,R2≠H, NR2) sind Amide und Thioamide, die mit metallorganischen Nucleophilen R‐M (M=Li, MgX, CeX2, TiX3, ZrX3) in tertiäre sec‐ und tert‐Alkylamine überführt werden. Mit Me3Al, MeTiCl3 oder Me2TiCl2 und Ketonen können andererseits direkt quartäre Zentren aufgebaut werden (R1R2CO→R1R2CMe2). Vor‐ und Nachteile der verschiedenen Methoden und Reaktionsmechanismen werden diskutiert. Die erstaunliche Vielfalt der so zugänglichen Strukturen wird an zahlreichen Beispielen demonstriert.
Generation of Secondary, Tertiary, and Quaternary Centers by Geminal Disubstitution of Carbonyl Oxygens
Authors: Seebach Dieter
Published: December 2010

Methods for replacing the carbonyl oxygen by two new substituents (CO→CR1R2) are discussed in this Minireview, whereby R may be H, NR2, alkyl, allyl, benzyl, vinyl, alkynyl, aryl, heteroaryl, or acyl groups. The most frequently used starting materials for geminal disubstitution with the formation of two CC bonds (R1,R2≠H, NR2) are amides and thioamides, which react with organometallic nucleophiles RM (M=Li, MgX, CeX2, TiX3, ZrX3) to give tertiary sec‐ and tert‐alkylamines. Quaternary centers can be built directly from ketones by treatment with Me3Al, MeTiCl3, or Me2TiCl2 (R1R2CO→R1R2CMe2). The scope and limitations of the various methods and mechanistic models are briefly discussed. The remarkable variety and diversity of structures thus accessible are demonstrated by numerous examples.
Neonatally measured immunoglobulins and risk of autism
Authors: Grether Judith K. , Croen Lisa A. , Anderson Meredith C. , Nelson Karin B. , Yolken Robert H.
Published: December 2010

Previous studies indicate that prenatal exposure to infections is a possible pathway through which autism spectrum disorders (ASD) could be initiated. We investigated whether immunoglobulin levels in archived specimens obtained from newborns subsequently diagnosed with ASD are different from levels in newborn specimens from controls. Children with ASD born in six California counties in 1994 were ascertained through records of the California Department of Developmental Services (DDS) and Kaiser Permanente; controls were randomly selected using birth certificates. Archived newborn blood specimens were obtained from the California Genetic Disease Screening Program (GDSP) for N = 213 cases and N = 265 controls and assayed to determine levels of total IgG, antigen‐specific IgG to selected common pathogens, total IgM, total IgA, and C‐reactive protein (CRP). We did not find measurable levels of total IgM or IgA in any neonate and measurable CRP was present in only a few. No antigen‐specific IgG antibodies were elevated in cases compared to controls and total IgG levels were lower. In adjusted models, a 10‐unit increase in total IgG yielded an OR = 0.72 (95% CI 0.56, 0.91); a significantly decreasing trend in risk of ASD was observed across increasing exposure quartiles of total IgG (P = 0.01). The finding of lower IgG in cases may indicate maternal immune dysfunction during gestation and/or impaired transplacental transfer of immunoglobulins. Further investigation of IgG levels in newborns and the mechanisms by which they might be associated with ASD are warranted.
Messtechnische Analyse flachgeneigter hölzerner Dachkonstruktionen mit Sparrenvolldämmung — Teil 2: Nicht belüftete, extensiv begrünte Dächer mit Zellulose‐ und Mineralwolledämmung
Authors: Nusser Bernd , Teibinger Martin , Bednar Thomas
Published: December 2010

Im gegenständlichen zweiten Teil dieser Aufsatzreihe werden die Messwerte aus zwei Gründachelementen, welche zum einen mit Mineralwolledämmung und feuchteadaptiver Dampfbremse und zum anderen mit Zellulosedämmung und Vliesdampfbremse ausgeführt sind, diskutiert. Dabei zeigt sich, dass die Temperatur auf der Dachabdichtung neben den Witterungsbedingungen auch vom Bewuchsgrad des Gründaches abhängt. Aufgrund der geringen sommerlichen Umkehrdiffusion der Gründächer kommt es zu erhöhten Luftfeuchten im Gefach. Dies führt beim Gründach mit Mineralwolledämmung zu erhöhten Materialfeuchten. Das Gründach mit Zellulosedämmung weist diese erhöhten Materialfeuchten hingegen weniger stark auf. Trotz der teilweise lang andauernden hohen Feuchtelast im Gefach der beiden Gründächer konnten weder Schimmel‐ noch holzzerstörende Pilze in diesen entdeckt werden.

Measuring investigations of the hygrothermal behaviour of timber flat roofs — Part 2: Non‐ventilated green roofs with cellulose and mineral wool insulation. In the second part of this article serial the measuring values of two green roof elements made of mineral wool insulation with a moisture adaptive vapour retarder and cellulose insulation with a fibrous vapour redarder are discussed. It is shown that the roof surface temperature, beside the weathering conditions, depends on the level of plant coverage. Because of very low drying potential of green roofs high air humidity occurs in the cavity. This leads to higher material moisture content in the element with mineral wool insulation. The green roof element with cellulose insulation shows this higher material moisture content less pronounced. Despite high moisture loads in the cavities of both green roof elements no mould or rot could be found in the investigated roofs.
Botanische Gärten in der Zeit des Kolonialismus. Auf der Jagd nach dem “Grünen Gold”
Authors: Schneckenburger Stefan
Published: December 2010

Eine Konstante der Geschichte ist unser Bedarf an Rohstoffen für Ernährung und Produktion von Gütern – gewandelt hat sich aber deren Natur: Anstelle zahlreicher Stoffe auf petrochemischer Basis standen früher überwiegend Rohstoffe aus der Pflanzenwelt. Oft ergab sich dabei das Problem, dass Herkunfts‐ und Abnehmerländer weit auseinander lagen, dass Monopole bestanden oder dass ein landwirtschaftlicher Anbau der entsprechenden Nutzpflanzen aus Platz‐ oder Arbeitskräftemangel in den Herkunftsländern nicht möglich oder aus Profitgründen nicht erwünscht war. An dieser Schnittstelle agierten Botanische Gärten mit Erfolg, aber den heutigen ethischen Vorstellungen wenig entsprechend. Der Beitrag veranschaulicht dies an Beispielen wie Tee, Kautschuk oder Chinarinde.
Durstige Pflanzen senden Signale. Trockenstress produziert Ultraschall
Authors: Mayr Stefan
Published: December 2010

Die Ultraschallemissionsanalyse, eine Methode aus dem Bereich der zerstörungsfreien Prüfung, kann auch zur Analyse von Schallemissionen in Pflanzen eingesetzt werden. Im Wassertransportsystem von Pflanzen treten Schallwellen im hörbaren‐ und im Ultraschallbereich auf, wenn hohe Zugspannungen zum plötzlichen Abreißen von Wasserfäden führen. Diese Kavitationen werden durch ein Übertreten von Luft aus benachbarten Leitelementen ausgelöst. Ultraschallereignisse können aber auch beim Frieren von austrocknenden Holzproben beobachtet werden. Die Ultraschallemissionsanalyse ermöglicht ein Monitoring von Kavitationen in Abhängigkeit von der Zugspannung, die Interpretation der registrierten Ereignisse ist allerdings oft schwierig. Zukünftige technische Entwicklungen und Forschungsaktivitäten werden es ermöglichen, diese pflanzlichen Schallemissionen besser zu verstehen.
Elf Millionen Jahre verschollen: die Laotische Felsenratte
Authors: Schmitz Jürgen
Published: December 2010

Als lebende Fossilien werden Arten bezeichnet, die über Jahrmillionen ihren Bauplan nur wenig geändert haben, aber auch solche, die als Überbleibsel einer einst großen Artenvielfalt heute noch existieren. Dabei ist deren Herkunft nicht immer leicht erkennbar. Die Laotische Felsenratte ist ein solches lebendes Fossil, dessen Vergangenheit nun durch viele Indizien eindeutig rekonstruiert werden konnte.
Spektakuläres Bernsteinvorkommen
Authors: Stebner Frauke , Rust Jes
Published: December 2010

In der indischen Provinz Gujarat wurde ein riesiges Bernsteinvorkommen entdeckt, welches eine Fülle pflanzlicher und tierischer Einschlüsse enthält und in vielerlei Hinsicht von großem wissenschaftlichem Interesse ist. Die in dem Bernstein enthaltenen Tiere weisen eine einzigartige Art der Erhaltung auf. Die systematische Auswertung der fossilen Einschlüsse wirft ein neues Licht auf die geologische Geschichte Indiens und seiner Flora und Fauna.
Der Freiburger Bächle‐Egel und die Alpha‐Taxonomie
Authors: Kutschera Ulrich
Published: December 2010

Neuentdeckungen und Beschreibungen relativ großer Tier‐ beziehungsweise Pflanzenarten (Makroorganismen) für Mitteleuropa sind nach 250 Jahren Biodiversitätsforschung eine Seltenheit. Mit Hilfe von DNA‐Sequenzanalysen wurde nun dennoch in Süddeutschland eine neue Egelart identifiziert, deren Beschreibung bereits vor 27 Jahren begann.
Was hat Mikroskopieren mit Köhlern zu tun?
Authors: Schrödel Andrea
Published: December 2010

Die Benutzung des Lichtmikroskops gehört zum Alltag in zytologisch und histologisch arbeitenden Laboren. Trotz täglicher Benutzung kennen viele jedoch nicht einmal die Funktionsteile eines Mikroskops. Oder wissen Sie, wie man die exakte Ausleuchtung des Sehfeldes an einem Mikroskop einstellt?
Nachrichten des Verbandes Biologie, Biowissenschaften & Biomedizin in Deutschland
Authors: Klug Jörg
Published: December 2010

Aus den Fachgesellschaften:

Gesellschaft für Versuchstierkunde

Neue Experten‐Datenbank

Ausbildung und Karriere:

BIOTECHNICA Studienpreis 2010

Wissenschaft und Gesellschaft:

Einspruch!

Aus den Landesverbänden:

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Baden‐Württemberg
Biosynthesis of the Spiroacetal Suite in Bactrocera tryoni
Authors: Booth Yvonne K. , Kitching William , De Voss James J.
Published: December 2010

In pursuit of a more environmentally benign method of controlling the highly pestiferous Queensland fruit fly, Bactrocera tryoni, the biosynthesis of the minor components in the suite of spiroacetals released by females has been investigated. This follows on the biosynthetic definition of the pathway to the major component, (E,E)‐1. The origins of the C12 and C13 spiroacetals (E,E)‐2 and (E,E)‐3, respectively, have been investigated by the administration of over 30 deuterated potential precursors. Analysis of the relative incorporation levels and identification of some of the exceptionally minor spiroacetals that were biosynthesised established that B. tryoni processes fatty acids to 2,6‐dioxygenated precursors by a modified β‐oxidation pathway, with a suite of putative cytochromes P450 employed in the crucial oxidative steps, prior to cyclisation of the proposed ketodiol.
ChemInform Abstract: Ternary Nitride GaFe3N: An Experimental and Quantum‐Theoretical Study.
Authors: Burghaus Jens , Wessel Michael , Houben Andreas , Dronskowski Richard
Published: December 2010

The thermodynamic stability of GaFe3N (space group Pm$\bar 3$m) is investigated by DFT calculations and the Vegard‐like behavior of the compound discussed earlier is resolved using Mo Kα1 XRD.