Miracle-dz/UniFAR-FTUs huggingface dataset:
Convexities , Nonconvexities , and Firm Export Behavior ∗

Models of heterogenous firms making decisions about entering foreign markets in the face of sunk entry costs have become standard tools for understanding the firm exporting decision. These models induce a discrete choice between exporting and only serving the domestic market. In this paper we study how well these discrete choice models account for the data on new export entrants. We document the employment responses of Colombian plants that enter the export market and find that, though there is a discrete nature to employment adjustment and exports, there is also a substantial amount of adjustment that continues after entry, which is contrary to a standard model with frictionless markets. We construct a dynamic discrete choice model of exporting that includes costs of adjusting labor inputs. We use simulation based methods to structurally estimate the parameters of the model and find that convex costs of labor adjustment are crucial for replicating the observed patterns of adjustment in the data. Our estimations also recover values for the entry costs that exporters face, adding to the small amount of evidence on the scale of these costs. The estimates of export entry costs increase by 21 percent when adjustment frictions are not accounted for, suggesting that entry cost estimates are sensitive to the model environment. ∗We would like to thank Mark Roberts and Jim Tybout for allowing us access to the data used here. This work was undertaken with the support of the National Science Foundation under grant SES-0536970. †University of Texas at Austin, ruhl@eco.utexas. edu ‡Federal Reserve Bank of Kansas City, jonathan.willis@kc.frb. org
FPGA implementation of SVPWM approximation

The PWM signal generator is a key element in DC-AC conversion and AC drives. A new scheme based on the approximation of Space Vector Pulse Width Modulation is proposed to minimize the mathematical complexity involved with the SVPWM, while retaining its advantages. The proposition has been implemented on FPGA using Hardware Description Language VHDL and its co-simulation with Simulink™/Matlab®. The new implementation consumes about 30% of the resources of the conventional method for synthesis using ISE Xilinx Design software on a Spartan3 Platform.
The use of hematopoietic growth factors in treating HIV infection

&NA; Human immunodeficiency virus infection causes multilineage hematopoietic defects. Defects in the production and function of CD4+ helper cells have been the focus of the majority of HIV research, but anemia, neutropenia, and thrombocytopenia are significant clinical problems as well. Bone marrow suppression is the dose-limiting toxicity for a number of antiviral and prophylactic medications. Hematopoietic growth factors such as granulocyte colony-stimulating factor or granulocyte-macrophage colony-stimulating factor are used to optimize the delivery of antiretroviral and prophylactic therapy. Because of the expense involved, the most appropriate use of these hematopoietic growth factors remains a subject of intense investigation. This review focuses on recent experimental results.
Teacher-Student Interaction in Special Education Classrooms

Although the literature on teacher behavior in regular classrooms has grown extensively in recent years. there are considerably less data on special education teachers. For example, it is known that about 80% of the questions asked by regular teachers are either factual or procedural [Gall, 1970) and that many regular teachers fail to make extensive use of reinforcement in class (Flanders, 1970). However, little is known about these and other categories of teacher behavior pertaining to special education teachers, particularly those for the educable mentally retarded and the educationally handicapped (a term used in California for classifying learning disabled and emotionally disturbed children). This investigation attempted to answer the following questions What are the teacher-student interaction patterns in special education classrooms? Are there differences between teachers of the educable mentally retarded and the educationally handicapped in their interaction toward their students? Do special education teachers exhibit the expectancy effect by behaving differently towards select students within a classroom whom the teachers perceive as exhibiting the most or least appropriate classroom behavior, profiting most or least from the class, and achieving at the highest or lowest academic levels? The data were collected in randomly selected self contained special education classrooms in two districts. Three educable mentally retarded and four educationally handicapped classes were from an urban school district, and two educable mentally retarded and three educationally handicapped classes were from a suburban district. Six coders using <1 version of the Brophy-Good Interaction Observation System [Brophy & Good, 1970), observed each teacher for a minimum of 10 hours of codable interaction time. The coders spent three weeks practicing in a laboratory and in
Differential Time Course of Glucagon's Effect on Glycogenolysis and Gluconeogenesis in the Conscious Dog

The evanescence of glucagon's effect on glucose production (GP) is well documented, but it is unclear (1) whether this response involves both glycogenolysis and gluconeogenesis and (2) whether the liver becomes dependent on the increased glucagon level for the maintenance of a basal supply of glucose. To answer these questions, conscious overnight-fasted dogs were given somatostatin (0.8 μg/kg · min) plus basal intraportal replacement amounts of insulin (273 μU/kg min) and glucagon (0.65 ng/kg · min) for 2 h, after which the rate of glucagon infusion was increased fourfold for 3 h and then returned to basal for 1.5 h. GP was determined using a primed infusion of [3-3H[ glucose, and gluconeogenesis (GNG) was estimatedby determining the conversion rate of alanine and lactate to glucose. An increase in the plasma glucagon level from 55 to 206 pg/ml resulted in an initial 180% increase in GP, followed by a decline such that after 3 h of hyperglucagonemia GP was increased by only 41%. Contrary to overall GP, gluconeogenesis increased progressively throughout the hyperglucagonemic period, eventually reaching a rate 3 times basal. Restoration of the basal glucagon level (63 pg/ml) caused a marked decline in GP and GNG. In fact, GP fell to a level 29% below the initial control rate and consequently the plasma glucose level fell rapidly. The data suggest that (1) the downregulation of glucagonstimulated GP is attributable to a decline in glycogenolysis and not gluconeogenesis, and (2) following adaptation to the hormone, the liver becomes dependent on the elevated glucagon concentration for the maintenance of basal glucose production.
Interpretation without Semantics

I suggest that Geoffrey Nunberg's work can make two contributions to the issue of the relationship of lexical semantics to knowledge representation. The first is the claim that Lexical Semantics and Knowledge Representation are the same. The second (which is both more controversial and more difficult to implement) is that the connection between this world knowledge and lexical items must be quite flexible, if not, in fact, non-existent and constructed anew for each interpretive act. I outline several arguments for this position and present a formal method of incorporating this within a standard Montague-grammar framework.
Improved Gait Algorithm and Mobility Performance of RT-Mover Type Personal Mobility Vehicle

We have developed a personal mobility vehicle (PMV) with four driven wheels that is capable of negotiating obstacles with a leg motion mechanism. When obstacles are encountered, wheels are lifted, moved ahead in a stepping-like motion, and lowered back down, thereby allowing the PMV to advance further. In our previous paper, we discussed the principle of the gait algorithm used by our PMV, in which wheels are utilized as legs to negotiate obstacles. In the original algorithm, when the wheels encountered terrain that might require leg motion to traverse, the system determined whether such motion was applicable and, if it was, orchestrated a series of leg motions. However, there were terrains that could not be negotiated using the original algorithm. In this paper, we propose an improved gait algorithm, in which when the vehicle encounters terrain intractable by leg motion with its current posture, the vehicle changes its posture until it can traverse that terrain. We verified the effectiveness of the improved gait algorithm through a variety of mobility tests with a passenger. In addition, we present numerical data on the range of terrain topologies that could be negotiated by the proposed algorithm.
Cortical Surface Shape Analysis Based on Spherical Wavelet Transformation

Shape analysis of neuroanatomical structures has proven useful in the study of neuropathology and neurodevelopment. Advances in medical imaging have made it possible to study this shape variation in vivo. In this paper, we propose the use of a spherical wavelet transformation to extract cortical surface shape features, as wavelets can characterize the underlying functions in a local fashion in both space and frequency. Our results demonstrate the utility of the wavelet approach in both detecting the spatial scale and pattern of shape variation in synthetic data, and for quantifying and visualizing shape variations of cortical surface models in subject populations.
Acanthamoeba Myosin IC Colocalizes with Phosphatidylinositol 4,5-Bisphosphate at the Plasma Membrane Due to the High Concentration of Negative Charge*

The tail of Acanthamoeba myosin IC (AMIC) has a basic region (BR), which contains a putative pleckstrin homology (PH) domain, followed by two Gly/Pro/Ala (GPA)-rich regions separated by a Src homology 3 (SH3) domain. Cryoelectron microscopy had shown that the tail is folded back on itself at the junction of BR and GPA1, and nuclear magnetic resonance spectroscopy indicated that the SH3 domain may interact with the putative PH domain. The BR binds to acidic phospholipids, and the GPA region binds to F-actin. We now show that the folded tail does not affect the affinity of AMIC for acidic phospholipids. AMIC binds phosphatidylinositol 4,5-bisphosphate (PIP2) with high affinity (∼1 μm), but binding is not stereospecific. When normalized to net negative charge, AMIC binds with equal affinity to phosphatidylserine (PS) and PIP2. This and other data show that the putative PH domain of AMIC is not a typical PIP2-specific PH domain. We have identified a 13-residue sequence of basic-hydrophobic-basic amino acids within the putative PH domain that may be a major determinant of binding of AMIC to acidic phospholipids. Despite the lack of stereospecificity, AMIC binds 10 times more strongly to vesicles containing 5% PIP2 plus 25% PS than to vesicles containing only 25% PS, suggesting that AMIC may be targeted to PIP2-enriched regions of the plasma membrane. In agreement with this, AMIC colocalizes with PIP2 at dynamic, protrusive regions of the plasma membrane. We discuss the possibility that AMIC binding to PIP2 may initiate the formation of a multiprotein complex at the plasma membrane.
Highly Pathogenic New World and Old World Human Arenaviruses Induce Distinct Interferon Responses in Human Cells

ABSTRACT The arenavirus family includes several important pathogens that cause severe and sometimes fatal diseases in humans. The highly pathogenic Old World (OW) arenavirus Lassa fever virus (LASV) is the causative agent of Lassa fever (LF) disease in humans. LASV infections in severe cases are generally immunosuppressive without stimulating interferon (IFN) induction, a proinflammatory response, or T cell activation. However, the host innate immune responses to highly pathogenic New World (NW) arenaviruses are not well understood. We have previously shown that the highly pathogenic NW arenavirus, Junin virus (JUNV), induced an IFN response in human A549 cells. Here, we report that Machupo virus (MACV), another highly pathogenic NW arenavirus, also induces an IFN response. Importantly, both pathogenic NW arenaviruses, in contrast to the OW highly pathogenic arenavirus LASV, readily elicited an IFN response in human primary dendritic cells and A549 cells. Coinfection experiments revealed that LASV could potently inhibit MACV-activated IFN responses even at 6 h after MACV infection, while the replication levels of MACV and LASV were not affected by virus coinfection. Our results clearly demonstrated that although all viruses studied herein are highly pathogenic to humans, the host IFN responses toward infections with the NW arenaviruses JUNV and MACV are quite different from responses to infections with the OW arenavirus LASV, a discovery that needs to be further investigated in relevant animal models. This finding might help us better understand various interplays between the host immune system and highly pathogenic arenaviruses as well as distinct mechanisms underlying viral pathogenesis. IMPORTANCE Infections of humans with the highly pathogenic OW LASV are accompanied by potent suppression of interferon or proinflammatory cytokine production. In contrast, infections with the highly pathogenic NW arenavirus JUNV are associated with high levels of IFNs and cytokines in severe and fatal cases. Arenaviruses initially target macrophages and dendritic cells, which are potent IFN/cytokine-producers. In human macrophages, JUNV reportedly does not trigger IFN responses. We here demonstrated that JUNV activated IFN responses in human dendritic cells. MACV, another highly pathogenic NW arenavirus, also activated IFN responses. LASV did not induce detectable IFN responses, in spite of higher replication levels, and blocked the MACV-triggered IFN response in a coinfection assay. Although these viruses are highly pathogenic to humans, our study highlights distinct innate immune responses to infections with the NW arenaviruses JUNV and MACV and to infection with the OW arenavirus LASV and provides important insights into the virus-host interaction and pathogenesis.
Testing and classification of individual plants for fire behaviour: plant selection for the wildland-urban interface

Knowledge of how species differ in their flammability characteristics is needed to develop more reliable lists of plants recommended for landscaping homes in the wildland-urban interface (WUI). As indicated by conflicting advice in such lists, such characterisation is not without difficulties and disagreements. The flammability of vegetation is often described as having four components (ignitability, combustibility, sustainability and consumability). No standards or generally recognised test procedures exist for evaluating these components in plants. Some measurements of flammability include times for ignition, rate of flame spread, flame height and heat release rate. Often, the fire behaviour characteristics of a plant are derived from its physical and chemical characteristics. Thermogravimetric analysis and other thermal analyses of ground samples have long been used to characterise the thermal degradation of vegetation. More recently, researchers have used the oxygen consumption methodology to measure the heat released due to combustion of the vegetation. Although oxygen consumption calorimetry is an improvement in characterising plant flammability, translation of laboratory results to field conditions can be problematic and tests can be expensive.
Developing theory from practice in teacher education

A century ago teaching was mastered mainly by trial and error: the (student) teacher was an apprentice of a master teacher and usually imitated his or her teaching. Gradually teacher education was professionalized and via, among others, normal schools we have now moved in Europe and on other continents to teacher education institutes, often as part of universities, in which theory and skills are taught (Wubbels, 1992a). From the literature, we know that the quality of student teachers' learning effects in student teaching Theo Wubbels is a practice and in the first years of teaching can be professor of education questioned. Many studies in the last ten years have and chair and Fred shown that student teachers do not learn everything Korthagen and Mieke we wantthemto learn (e.g., Ashton, 1996). Training Brekelmans are associate at the preservice level has not a high impact on professors of education, attitudes and beliefs of student teachers (Richardson, all with the IVLOS 1996). Skills and theories that have been taught on Institute of Education, campus often are not used in student teaching prac Utrecht University, tice. Many teacher education students even have Utrecht, The Netherlands. negative attitudes towards theory presented to them
Referendum-led Immigration Policy in the Welfare State

Majority voting outcomes over different immigration levels of lowskilled workers are examined in a two-period overlapping-generation model in which the labour market and intra- and intergenerational transfer schemes translate the impact of immigration into preferences of heterogeneous citizens. In most of the cases being examined, the model predicts a unique policy choice. However, a voting cycle can also arise in certain circumstances, subjecting the referendum outcome to manipulation.
Cellular Mechanisms of Mainstream Cigarette Smoke-Induced Lung Epithelial Tight Junction Permeability Changes In Vitro

Mainstream cigarette smoke increases the permeability of human airways; however, the mechanism for this increased permeability is poorly defined. Tight junctions between adjacent epithelial cells constitute the physiological barrier to fluid and macromolecules in epithelium. These structures are highly regulated by phosphorylation and their association with the cytoskeleton. The goal of these studies was to identify the signal transduction pathways that regulate smoke-induced permeability. Using a physiologically relevant air–liquid interface exposure system, electrically tight monolayers of the human bronchial epithelial cell-line Calu-3 were exposed to fresh, whole mainstream cigarette smoke. This exposure results in a regulated, dose-dependent loss of epithelial barrier function in the lung epithelial monolayers. With cigarette smoke exposure, transepithelial electrical resistance (TER) is decreased and albumin flux is increased, indicating a loss in barrier function to ions and macromolecules, respectively; however, both largely recover in 30 min. Smoke-induced losses of macromolecular barrier function are the result of multicellular junctional reorganization, resulting in increased leak volume rather than leak frequency. Inhibiting Rho kinase (ROCK) significantly reduces the smoke-induced permeability to both ions and macromolecules, while inhibiting protein tyrosine kinases (PTK) only reduces smoke-induced macromolecular permeability. Interestingly, inhibiting myosin light chain kinase (MLCK) exacerbates smoke-induced permeability, indicating that MLCK and ROCK have opposing regulatory roles. Our results demonstrate that the smoke-induced loss of epithelial barrier function in human bronchial epithelium is a regulated process rather than a cytotoxic response. Additionally, our results indicate that activation of PTK and ROCK and inactivation of MLCK contribute to the increased airway permeability caused by mainstream cigarette smoke.
Repeated zero-sum games with budget

When a zero-sum game is played once, a risk-neutral player will want to maximize his expected outcome in that single play. However, if that single play instead only determines how much one player must pay to the other, and the same game must be played again, until either player runs out of money, optimal play may differ. Optimal play may require using different strategies depending on how much money has been won or lost. Computing these strategies is rarely feasible, as the state space is often large. This can be addressed by playing the same strategy in all situations, though this will in general sacrifice optimality. Purely maximizing expectation for each round in this way can be arbitrarily bad. We therefore propose a new solution concept that has guaranteed performance bounds, and we provide an efficient algorithm for computing it. The solution concept is closely related to the Aumann-Serrano index of riskiness, that is used to evaluate different gambles against each other. The primary difference is that instead of being offered fixed gambles, the game is adversarial.
The natural killer cell‐mediated killing of autologous dendritic cells is confined to a cell subset expressing CD94/NKG2A, but lacking inhibitory killer Ig‐like receptors

The cognate NK–DC interaction in inflamed tissues results in NK cell activation and acquisition of cytotoxicity against immature DC (iDC). This may represent a mechanism of DC selection required for the control of downstream adaptive immune responses. Here we show that killing of monocyte‐derived iDC is confined to the NK cell subset that expresses CD94/NKG2A, but not killer Ig‐like receptors (KIR). Consistent with these data, the expression of HLA‐E (i.e. the cellular ligand of CD94/NKG2A) was down‐regulated in iDC. On the other hand, HLA‐B and HLA‐C down‐regulation in iDC was not sufficient to induce cytotoxicity in NK cells expressing KIR3DL1 or KIR2DL. Remarkably, CD94/NKG2A+KIR– NK cells were heterogeneous in their ability to kill iDC and an inverse correlation existed between their CD94/NKG2A surface density and the magnitude of their cytolytic activity. It is conceivable that the reduced CD94/NKG2A surface density enables these cells to efficiently sense the decrease of HLA‐E surface expression in iDC. Finally, most NK cells that lysed iDC did not kill mature DC that express higher amounts of HLA class I molecules (including HLA‐E)as compared with iDC. However, a small NK cell subset was capable of killing not only iDC but also mature DC.
NetCube: A Scalable Tool for Fast Data Mining and Compression

We propose an novel method of computing and storing DataCubes. Our idea is to use Bayesian Networks, which can generate approximate counts for any query combination of attribute values and “don’t cares. ” A Bayesian network represents the underlying joint probability distribution of the data that were used to generate it. By means of such a network the proposed method, NetCube, exploits correlations among attributes. Our proposed preprocessing algorithm scales linearly on the size of the database, and is thus scalable; it is also parallelizable with a straightforward parallel implementation. Moreover, we give an algorithm to estimate counts of arbitrary queries that is fast ( constant on the database size). Experimental results show that NetCubes have fast generation and use (a few