Showing papers by "University of Freiburg published in 2003"
TL;DR: The importance of zircon in crustal evolution studies is underscored by its predominant use in U-Th-Pb geochronology and investigations of the temporal evolution of both the crust and lithospheric mantle as discussed by the authors.
Abstract: Zircon is the main mineral in the majority of igneous and metamorphic rocks with Zr as an essential structural constituent. It is a host for significant fractions of the whole-rock abundance of U, Th, Hf, and the REE (Sawka 1988, Bea 1996, O’Hara et al. 2001). These elements are important geochemically as process indicators or parent isotopes for age determination. The importance of zircon in crustal evolution studies is underscored by its predominant use in U-Th-Pb geochronology and investigations of the temporal evolution of both the crust and lithospheric mantle. In the past decade an increasing interest in the composition of zircon, trace-elements in particular, has been motivated by the effort to better constrain in situ microprobe-acquired isotopic ages. Electron-beam compositional imaging and isotope-ratio measurement by in situ beam techniques—and the micrometer-scale spatial resolution that is possible—has revealed in many cases that single zircon crystals contain a record of multiple geologic events. Such events can either be zircon-consuming, alteration, or zircon-forming and may be separated in time by millions or billions of years. In many cases, calculated zircon isotopic ages do not coincide with ages of geologic events determined from other minerals or from whole-rock analysis. To interpret the geologic validity and significance of multiple ages, and ages unsupported by independent analysis of other isotopic systems, has been the impetus for most past investigations of zircon composition. Some recent compositional investigations of zircon have not been directly related to geochronology, but to the ability of zircon to influence or record petrogenetic processes in igneous and metamorphic systems.
Sedimentary rocks may also contain a significant fraction of zircon. Although authigenic zircon has been reported (Saxena 1966, Baruah et al. 1995, Hower et al. 1999), it appears to be very rare and may in fact be related to …
3,777 citations
French Institute of Health and Medical Research1, University of Freiburg2, Hospital Research Foundation3, Medical Research Council4, Utrecht University5, Harvard University6, Pasteur Institute7, Babraham Institute8, University of Paris9, Curie Institute10, National Institutes of Health11, University of Sydney12, Ludwig Maximilian University of Munich13, LSU Health Sciences Center New Orleans14
TL;DR: Retrovirus vector insertion can trigger deregulated premalignant cell proliferation with unexpected frequency, most likely driven by retrovirus enhancer activity on the LMO2 gene promoter.
Abstract: We have previously shown correction of X-linked severe combined immunodeficiency [SCID-X1, also known as gamma chain (gamma(c)) deficiency] in 9 out of 10 patients by retrovirus-mediated gamma(c) gene transfer into autologous CD34 bone marrow cells. However, almost 3 years after gene therapy, uncontrolled exponential clonal proliferation of mature T cells (with gammadelta+ or alphabeta+ T cell receptors) has occurred in the two youngest patients. Both patients' clones showed retrovirus vector integration in proximity to the LMO2 proto-oncogene promoter, leading to aberrant transcription and expression of LMO2. Thus, retrovirus vector insertion can trigger deregulated premalignant cell proliferation with unexpected frequency, most likely driven by retrovirus enhancer activity on the LMO2 gene promoter.
3,514 citations
TL;DR: In this paper, the development in the field of coordination polymers or metal-organic coordination networks, MOCNs (metal-organic frameworks, MOFs) is assessed in terms of property investigations in the areas of catalysis, chirality, conductivity, luminescence, magnetism, spin-transition (spin-crossover), nonlinear optics (NLO) and porosity or zeolitic behavior upon which potential applications could be based.
Abstract: The development in the field of coordination polymers or metal-organic coordination networks, MOCNs (metal-organic frameworks, MOFs) is assessed in terms of property investigations in the areas of catalysis, chirality, conductivity, luminescence, magnetism, spin-transition (spin-crossover), non-linear optics (NLO) and porosity or zeolitic behavior upon which potential applications could be based.
3,117 citations
TL;DR: In this paper, a selection of both the most typical, but also of the less common, features seen in zircon, categorized according to the different geological processes responsible for their formation are presented.
Abstract: The mineral zircon is extremely variable both in terms of external morphology and internal textures. These features reflect the geologic history of the mineral, especially the relevant episode(s) of magmatic or metamorphic crystallization (and recrystallization), strain imposed both by external forces and by internal volume expansion caused by metamictization, and chemical alteration. The paper presents a selection of both the most typical, but also of the less common, features seen in zircon, categorized according to the different geological processes responsible for their formation. The atlas is intended as a general guide for the interpretation of zircon characteristics, and of related isotopic data.
Zircon has become one of the most widely used minerals for the extraction of information on the prehistory and genesis of magmatic, metamorphic and sedimentary rocks. Much of the geological usefulness of zircon stems from its suitability as a geochronometer based on the decay of U (and Th) to Pb, but in addition it is also the major host of the radiogenic isotopic tracer Hf, and it is used to determine oxygen isotopic compositions and REE and other trace element abundances, all of which yield useful clues concerning the history of the host rock, and in some case, the parent rock in which the precursor zircon crystallized.
One of the major advantages of zircon is its ability to survive magmatic, metamorphic and erosional processes that destroy most other common minerals. Zircon-forming events tend to be preserved as distinct structural entities on a pre-existing zircon grain. Because of this ability, quite commonly zircon consists of distinct segments, each preserving a particular period of zircon-formation (or consumption). A long experience and modern instrumentation and techniques have provided the “zircon community” the means to image and interpret preserved textures, and hence to decipher the history and evolution of a rock. One …
3,069 citations
TL;DR: The sustained correction of X-linked severe combined immunodeficiency disease by ex vivo, retrovirally mediated transfer of the γc gene into CD34+ cells in four of five patients with the disease has been reported.
Abstract: To the Editor: We recently reported (April 18 issue)1 the sustained correction of X-linked severe combined immunodeficiency disease by ex vivo, retrovirally mediated transfer of the γc gene into CD34+ cells in four of five patients with the disease. These results have since been confirmed in four additional patients with typical X-linked severe combined immunodeficiency. Of the first four successfully treated patients, three continue to do well up to 3.6 years after gene therapy, whereas a serious adverse event occurred in the fourth patient. At a routine checkup 30 months after gene therapy, lymphocytosis consisting of a monoclonal population . . .
1,869 citations
Shimane University1, University of Freiburg2, University of Manitoba3, University of Kentucky4, University of Marburg5, St. Michael's Hospital6, Baylor College of Medicine7, University of Illinois at Urbana–Champaign8, Scripps Health9, Oregon Health & Science University10, Tulane University11, Mayo Clinic12, Michigan State University13, Max Planck Society14, University of Göttingen15, University of California, Los Angeles16, Rutgers University17, Seton Hall University18
TL;DR: This scale meets performance criteria for a brief, patient completed instrument that can be used to assess RLS severity for purposes of clinical assessment, research, or therapeutic trials and supports a finding that RLS is a relatively uniform disorder in which the severity of the basic symptoms is strongly related to their impact on the patient's life.
1,439 citations
TL;DR: This review integrates recent physiological and molecular understanding of the role of podocytes during the maintenance and failure of the glomerular filtration barrier with hereditary nephrotic syndromes identified over the last 2 years.
Abstract: Glomerular podocytes are highly specialized cells with a complex cytoarchitecture. Their most prominent features are interdigitated foot processes with filtration slits in between. These are bridged by the slit diaphragm, which plays a major role in establishing the selective permeability of the glomerular filtration barrier. Injury to podocytes leads to proteinuria, a hallmark of most glomerular diseases. New technical approaches have led to a considerable increase in our understanding of podocyte biology including protein inventory, composition and arrangement of the cytoskeleton, receptor equipment, and signaling pathways involved in the control of ultrafiltration. Moreover, disturbances of podocyte architecture resulting in the retraction of foot processes and proteinuria appear to be a common theme in the progression of acquired glomerular disease. In hereditary nephrotic syndromes identified over the last 2 years, all mutated gene products were localized in podocytes. This review integrates our recent physiological and molecular understanding of the role of podocytes during the maintenance and failure of the glomerular filtration barrier.
1,358 citations
TL;DR: It is indicated that eNOS expressed by bone marrow stromal cells influences recruitment of stem and progenitor cells, which may contribute to impaired regeneration processes in ischemic heart disease patients, who are characterized by a reduced systemic NO bioactivity.
Abstract: Endothelial nitric oxide synthase (eNOS) is essential for neovascularization. Here we show that the impaired neovascularization in mice lacking eNOS is related to a defect in progenitor cell mobilization. Mice deficient in eNOS (Nos3(-/-)) show reduced vascular endothelial growth factor (VEGF)-induced mobilization of endothelial progenitor cells (EPCs) and increased mortality after myelosuppression. Intravenous infusion of wild-type progenitor cells, but not bone marrow transplantation, rescued the defective neovascularization of Nos3(-/-) mice in a model of hind-limb ischemia, suggesting that progenitor mobilization from the bone marrow is impaired in Nos3(-/-) mice. Mechanistically, matrix metalloproteinase-9 (MMP-9), which is required for stem cell mobilization, was reduced in the bone marrow of Nos3(-/-) mice. These findings indicate that eNOS expressed by bone marrow stromal cells influences recruitment of stem and progenitor cells. This may contribute to impaired regeneration processes in ischemic heart disease patients, who are characterized by a reduced systemic NO bioactivity.
1,352 citations
TL;DR: It is reported that individuals with Noonan syndrome and juvenile myelomonocytic leukemia have germline mutations in PTPN11 and that somatic mutations in MDS and AML account for 34% of non-syndromic JMML.
Abstract: We report here that individuals with Noonan syndrome and juvenile myelomonocytic leukemia (JMML) have germline mutations in PTPN11 and that somatic mutations in PTPN11 account for 34% of non-syndromic JMML. Furthermore, we found mutations in PTPN11 in a small percentage of individuals with myelodysplastic syndrome (MDS) and de novo acute myeloid leukemia (AML). Functional analyses documented that the two most common mutations in PTPN11 associated with JMML caused a gain of function.
966 citations
University of Western Australia1, University of Yamanashi2, University of Newcastle3, National Oceanic and Atmospheric Administration4, University of South Carolina5, University of California, Berkeley6, Oregon State University7, University of São Paulo8, Newcastle University9, University of Saskatchewan10, University of Freiburg11
TL;DR: The IAHS Decade on Predictions in Ungauged Basins (PUB) as discussed by the authors is a new initiative launched by the International Association of Hydrological Sciences (IAHS) aimed at formulating and implementing appropriate science programmes to engage and energize the scientific community, in a coordinated manner, towards achieving major advances in the capacity to make predictions in ungauged basins.
Abstract: Drainage basins in many parts of the world are ungauged or poorly gauged, and in some cases existing measurement networks are declining. The problem is compounded by the impacts of human-induced changes to the land surface and climate, occur-ring at the local, regional and global scales. Predictions of ungauged or poorly gauged basins under these conditions are highly uncertain. The IAHS Decade on Predictions in Ungauged Basins, or PUB, is a new initiative launched by the International Association of Hydrological Sciences (IAHS), aimed at formulating and implementing appropriate science programmes to engage and energize the scientific community, in a coordinated manner, towards achieving major advances in the capacity to make predictions in ungauged basins. The PUB scientific programme focuses on the estimation of predictive uncertainty, and its subsequent reduction, as its central theme. A general hydrological prediction system contains three components: (a) a model that describes the key processes of interest, (b) a set of parameters that represent those landscape properties that govern critical processes, and (c) appropriate meteorological inputs (where needed) that drive the basin response. Each of these three components of the prediction system, is either not known at all, or at best known imperfectly, due to the inherent multi-scale space-time heterogeneity of the hydrological system, especially in ungauged basins. PUB will therefore include a set of targeted scientific programmes that attempt to make inferences about climatic inputs, parameters and model structures from available but inadequate data and process knowledge, at the basin of interest and/or from other similar basins, with robust measures of the uncertainties involved, and their impacts on predictive uncertainty. Through generation of improved understanding, and methods for the efficient quantification of the underlying multi-scale heterogeneity of the basin and its response, PUB will inexorably lead to new, innovative methods for hydrological predictions in ungauged basins in different parts of the world, combined with significant reductions of predictive uncertainty. In this way, PUB will demonstrate the value of data, as well as provide the information needed to make predictions in ungauged basins, and assist in capacity building in the use of new technologies. This paper presents a summary of the science and implementation plan of PUB, with a call to the hydrological community to participate actively in the realization of these goals.
938 citations
TL;DR: The International Ascites Club, representing the spectrum of clinical practice from North America to Europe, have developed guidelines by consensus in the management of cirrhotic ascites from the early ascitic stage to the stage of refractory ascites.
TL;DR: This document is intended to be used for educational purposes only and should not be relied on as a guide for making decisions about major decisions about copyrighted material.
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TL;DR: The phenotype of human ICOS deficiency, which differs in key aspects from that of the ICOS−/− mouse, suggests a critical involvement of ICOS in T cell help for late B cell differentiation, class-switching and memory B cell generation.
Abstract: No genetic defect is known to cause common variable immunodeficiency (CVID), a heterogeneous human disorder leading to adult-onset panhypogammaglobulinemia. In a search for CVID candidate proteins, we found four of 32 patients to lack ICOS, the "inducible costimulator" on activated T cells, due to an inherited homozygous deletion in the ICOS gene. T cells from these individuals were normal with regard to subset distribution, activation, cytokine production and proliferation. In contrast, naive, switched and memory B cells were reduced. The phenotype of human ICOS deficiency, which differs in key aspects from that of the ICOS-/- mouse, suggests a critical involvement of ICOS in T cell help for late B cell differentiation, class-switching and memory B cell generation.
TL;DR: A snapshot on where knowledge on the Bcl-2 family is on this journey and how it may be exploited to unveil the mysteries of immune regulation is provided.
TL;DR: Metabolic labeling with 5-bromouridine 5′-triphosphate in the presence of actinomycin D revealed that the membranous web is the site of viral RNA synthesis and therefore represents the replication complex of HCV.
Abstract: Formation of a membrane-associated replication complex, composed of viral proteins, replicating RNA, and altered cellular membranes, is a characteristic feature of plus-strand RNA viruses. Here, we demonstrate the presence of a specific membrane alteration, designated the membranous web, that contains hepatitis C virus (HCV) nonstructural proteins, as well as viral plus-strand RNA, in Huh-7 cells harboring autonomously replicating subgenomic HCV RNAs. Metabolic labeling with 5-bromouridine 5'-triphosphate in the presence of actinomycin D revealed that the membranous web is the site of viral RNA synthesis and therefore represents the replication complex of HCV.
08 Dec 2003
TL;DR: In this paper a novel algorithm that combines Rao-Blackwellized particle filtering and scan matching is presented, which reduces the particle depletion problem that typically prevents the robot from closing large loops.
Abstract: The ability to learn a consistent model of its environment is a prerequisite for autonomous mobile robots. A particularly challenging problem in acquiring environment maps is that of closing loops; loops in the environment create challenging data association problems [J.-S. Gutman et al., 1999]. This paper presents a novel algorithm that combines Rao-Blackwellized particle filtering and scan matching. In our approach scan matching is used for minimizing odometric errors during mapping. A probabilistic model of the residual errors of scan matching process is then used for the resampling steps. This way the number of samples required is seriously reduced. Simultaneously we reduce the particle depletion problem that typically prevents the robot from closing large loops. We present extensive experiments that illustrate the superior performance of our approach compared to previous approaches.
TL;DR: The interaction and colocalization in cilia of inversin, nephrocystin and β-tubulin connect pathogenetic aspects of NPHP to PKD, to primary cilia function and to left-right axis determination.
Abstract: Nephronophthisis (NPHP), an autosomal recessive cystic kidney disease, leads to chronic renal failure in children. The genes mutated in NPHP1 and NPHP4 have been identified, and a gene locus associated with infantile nephronophthisis (NPHP2) was mapped. The kidney phenotype of NPHP2 combines clinical features of NPHP and polycystic kidney disease (PKD). Here, we identify inversin (INVS) as the gene mutated in NPHP2 with and without situs inversus. We show molecular interaction of inversin with nephrocystin, the product of the gene mutated in NPHP1 and interaction of nephrocystin with β-tubulin, a main component of primary cilia. We show that nephrocystin, inversin and β-tubulin colocalize to primary cilia of renal tubular cells. Furthermore, we produce a PKD-like renal cystic phenotype and randomization of heart looping by knockdown of invs expression in zebrafish. The interaction and colocalization in cilia of inversin, nephrocystin and β-tubulin connect pathogenetic aspects of NPHP to PKD, to primary cilia function and to left-right axis determination.
TL;DR: Seven percent of the electromagnetic radiation emitted from the sun is in the UV range (200–400 nm).
Abstract: Seven percent of the electromagnetic radiation emitted from the sun is in the UV range (200–400 nm). As it passes through the atmosphere, the total flux transmitted is greatly reduced, and the composition of the UV radiation is modified. Shortwave UV-C radiation (200–280 nm) is completely
TL;DR: It would be worthwhile to investigate if early adequate treatment is able to prevent psychiatric sequelae of primary insomnia, as insomniac symptoms alone seem to be of predictive value for the development of depression in the succeeding years.
TL;DR: The volume of antibiotics used in hospitals and private households and released into effluent and municipal sewage indicates a selection pressure on bacteria.
TL;DR: Live-cell auxin imaging provides unprecedented insights into gravity-regulated auxin flux at cellular resolution, and strongly suggests that this flux is a prerequisite for root gravitropism.
Abstract: Gravity-induced root curvature has long been considered to be regulated by differential distribution of the plant hormone auxin. However, the cells establishing these gradients, and the transport mechanisms involved, remain to be identified. Here, we describe a GFP-based auxin biosensor to monitor auxin during Arabidopsis root gravitropism at cellular resolution. We identify elevated auxin levels at the root apex in columella cells, the site of gravity perception, and an asymmetric auxin flux from these cells to the lateral root cap (LRC) and toward the elongation zone after gravistimulation. We differentiate between an efflux-dependent lateral auxin transport from columella to LRC cells, and an efflux- and influx-dependent basipetal transport from the LRC to the elongation zone. We further demonstrate that endogenous gravitropic auxin gradients develop even in the presence of an exogenous source of auxin. Live-cell auxin imaging provides unprecedented insights into gravity-regulated auxin flux at cellular resolution, and strongly suggests that this flux is a prerequisite for root gravitropism.
TL;DR: It is demonstrated for the first time that cellular binding of HCV envelope requires E2-HSPG interaction, and docking of E2 to cellular HSPG may be the initial step in the interaction between HCV and the cell surface resulting in receptor-mediated entry and initiation of infection.
TL;DR: In this paper, whether judicial independence affects economic growth is tested for a cross section of 57 countries and the authors find that while de facto JI does not have an impact on real GDP growth per capita, de iure JI positively influences it.
Abstract: Rational politicians are interested in judicial independence (JI) in order to make their promises credible. But if politicians' preferences deviate from the dicta of the judiciary, they also have incentives to renege on judicial independence. These two conflicting aspects are measured by two indicators: (i) de iure JI focusing on its legal foundations and (ii) a de facto JI focusing on countries' actual experience. Whether JI affects economic growth is tested for a cross section of 57 countries. While de iure JI does not have an impact on real GDP growth per capita, de facto JI positively influences it.
TL;DR: It is concluded that Rac plays a dominant role in the PI(3,4,5)P3-dependent positive feedback loop required for forming a leading edge, whereas location and stability of the leading edge are regulated by Cdc42.
Abstract: Neutrophils exposed to chemoattractants polarize and accumulate polymerized actin at the leading edge. In neutrophil-like HL-60 cells, this asymmetry depends on a positive feedback loop in which accumulation of a membrane lipid, phosphatidylinositol (PI) 3,4,5-trisphosphate (PI[3,4,5]P3), leads to activation of Rac and/or Cdc42, and vice versa. We now report that Rac and Cdc42 play distinct roles in regulating this asymmetry. In the absence of chemoattractant, expression of constitutively active Rac stimulates accumulation at the plasma membrane of actin polymers and of GFP-tagged fluorescent probes for PI(3,4,5)P3 (the PH domain of Akt) and activated Rac (the p21-binding domain of p21-activated kinase). Dominant negative Rac inhibits chemoattractant-stimulated accumulation of actin polymers and membrane translocation of both fluorescent probes and attainment of morphologic polarity. Expression of constitutively active Cdc42 or of two different protein inhibitors of Cdc42 fails to mimic effects of the Rac mutants on actin or PI(3,4,5)P3. Instead, Cdc42 inhibitors prevent cells from maintaining a persistent leading edge and frequently induce formation of multiple, short lived leading edges containing actin polymers, PI(3,4,5)P3, and activated Rac. We conclude that Rac plays a dominant role in the PI(3,4,5)P3-dependent positive feedback loop required for forming a leading edge, whereas location and stability of the leading edge are regulated by Cdc42.
TL;DR: In this article, a selective review examines theoretical perspectives on the role of on-demand help in interactive learning environments, reviews literature on the relations between help seeking and learning in ILEs, and identifies reasons for the lack of effective help use.
Abstract: Many interactive learning environments (ILEs) offer on-demand help, intended to positively influence learning. Recent studies report evidence that although effective help-seeking behavior in ILEs is related to better learning outcomes, learners are not using help facilities effectively. This selective review (a) examines theoretical perspectives on the role of on-demand help in ILEs, (b) reviews literature on the relations between help seeking and learning in ILEs, and (c) identifies reasons for the lack of effective help use. We review the effect of system-related factors, of student-related factors, and of interactions between these factors. The interaction between metacognitive skills and cognitive factors is important for appropriate help seeking, as are a potentially large space of system-related factors as well as interactions among learner- and system-related factors. We suggest directions for future research.
TL;DR: In this paper, theoretical analyses of different types of cognitive load and their changes over the stages of skill acquisition are presented, and a fading procedure is proposed to integrate problem-solving elements into example study until the learners are expected to solve problems on their own.
Abstract: Cognitive load research has shown that learning from worked-out examples, in comparison to problem solving, is very effective during the initial stages of cognitive skill acquisition In later stages, however, solving problems is superior In this contribution, theoretical analyses of different types of cognitive load and their changes over the stages of skill acquisition are presented Two basic arguments are put forth: (a) Intrinsic cognitive load gradually decreases so that a gradual increase of problem-solving demands is possible without inducing cognitive overload (b) In contrast to the earlier stages, different learner activities during the later stages constitute either germane or extraneous load, because different instructional goals are to be achieved Based on these analyses, we propose a fading procedure in which problem-solving elements are successively integrated into example study until the learners are expected to solve problems on their own Empirical evidence supporting this fading proce
TL;DR: This paper introduces sample-based joint probabilistic data association filters as a new algorithm to track multiple moving objects using Bayesian filtering to adapt the tracking process to the number of objects in the perceptual range of the robot.
Abstract: One of the goals in the field of mobile robotics is the development of mobile platforms which operate in populated environments. For many tasks it is therefore highly desirable that a robot can track the positions of the humans in its surrounding. In this paper we introduce sample-based joint probabilistic data association filters as a new algorithm to track multiple moving objects. Our method applies Bayesian filtering to adapt the tracking process to the number of objects in the perceptual range of the robot. The approach has been implemented and tested on a real robot using laser-range data. We present experiments illustrating that our algorithm is able to robustly keep track of multiple people. The experiments furthermore show that the approach outperforms other techniques developed so far.
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TL;DR: This paper uses a stagewise fitting process to construct the logistic regression models that can select relevant attributes in the data in a natural way, and shows how this approach can be used to build the logistics regression models at the leaves by incrementally refining those constructed at higher levels in the tree.
Abstract: Tree induction methods and linear models are popular techniques for supervised learning tasks, both for the prediction of nominal classes and continuous numeric values. For predicting numeric quantities, there has been work on combining these two schemes into 'model trees', i.e. trees that contain linear regression functions at the leaves. In this paper, we present an algorithm that adapts this idea for classification problems, using logistic regression instead of linear regression. We use a stagewise fitting process to construct the logistic regression models that can select relevant attributes in the data in a natural way, and show how this approach can be used to build the logistic regression models at the leaves by incrementally refining those constructed at higher levels in the tree. We compare the performance of our algorithm against that of decision trees and logistic regression on 32 benchmark UCI datasets, and show that it achieves a higher classification accuracy on average than the other two methods.
TL;DR: This paper combined fading with the introduction of prompts designed to encourage learners to identify the underlying principle illustrated in each worked-out solution step and found that this combination produced medium to large effects on near and far transfer without requiring additional time on task.
Abstract: Although research has demonstrated that successively fading or successively removing more and more worked-out solution steps as learners transition from relying on examples to independent problem solving reliably fosters performance on near-transfer tasks—relative to example–problem pairs—this effect is not reliable on far-transfer tasks. To address this, the authors combined fading with the introduction of prompts designed to encourage learners to identify the underlying principle illustrated in each worked-out solution step. Across 2 experiments, this combination produced medium to large effects on near and far transfer without requiring additional time on task. Thus, the instructional procedure is highly recommendable because it (a) is relatively straightforward to implement, (b) does not prolong learning time, and (c) fosters both near- and far-transfer performance. Worked-out examples typically consist of a problem formulation, solution steps, and the final answer itself. Research indicates that exposure to worked-out examples is critical when learners are in the initial stages of learning a new cognitive skill in wellstructured domains such as mathematics, physics, and computer programming (Anderson, Fincham, & Douglass, 1997). Moreover, studies performed by Sweller and his colleagues (e.g., Sweller &
TL;DR: Extent of resection and surgical technique had a greater impact on the rates of permanent postoperative hypoparathyroidism than thyroid pathologic condition.