Miracle-dz/UniFAR-FTUs huggingface dataset:
Efficient Production of Active Polyhydroxyalkanoate Synthase in Escherichia coli by Coexpression of Molecular Chaperones

ABSTRACT The type I polyhydroxyalkanoate synthase from Cupriavidus necator was heterologously expressed in Escherichia coli with simultaneous overexpression of chaperone proteins. Compared to expression of synthase alone (14.55 mg liter−1), coexpression with chaperones resulted in the production of larger total quantities of enzyme, including a larger proportion in the soluble fraction. The largest increase was seen when the GroEL/GroES system was coexpressed, resulting in approximately 6-fold-greater enzyme yields (82.37 mg liter−1) than in the absence of coexpressed chaperones. The specific activity of the purified enzyme was unaffected by coexpression with chaperones. Therefore, the increase in yield was attributed to an enhanced soluble fraction of synthase. Chaperones were also coexpressed with a polyhydroxyalkanoate production operon, resulting in the production of polymers with generally reduced molecular weights. This suggests a potential use for chaperones to control the physical properties of the polymer.
Curricular Reforms in Latin America with Special Emphasis on the Argentine Case

The purpose of this article is to describe the effect of the curricular reforms introduced in Latin America in the 1990s. Special emphasis is placed on the Argentine case. Therefore, this work initially makes a historical synthesis of the curricular policies in the region, from the creation of modern education systems by the end of the nineteenth century, up to the present. Secondly, the proposals for education reforms during the 1990s are put forward, with an emphasis on the Argentine experience. The search for some degree of decentralisation of the curricular policies and, at the same time, the emergence of centralised systems of educational assessment, are the issues treated in this section. Lastly, the work discusses the concrete effects that the reform policies have had in the Argentine case. The central hypothesis is that far from a decentralisation of decision-making responsibilities in terms of curriculum, the system is hyper-regulated as a consequence of the interaction of several factors, many of which are related to the centralised tradition which has characterised the development and management of curriculum in most countries in the region.
Racial Differences in Eighth Grade Students’ Identification With Academics

Having a positive attitude about school, valuing school, and being intrinsically motivated is associated with higher grades, graduation, and college attendance. However, the literature reveals that these characteristics and attitudes are not uniform across race, class, and gender. The purpose of the current study was to examine racial differences in student identification with middle school. Specifically the study looked at the ways in which African American and White students described abstract and concrete components of identification. A total of 256 African American and 208 White eighth grade students from four middle schools in the Midwest completed a 13-item Identification with Academics survey as part of a large study of the transition from middle school to high school. Results show that African American students held higher abstract identification with academics than White students. Step-wise linear regression analysis demonstrates that the abstract identification is associated with academic achievement controlling for demographic characteristics. The findings of the study have implications for developing and assessing programs that help students to think about their identification with academics.
Stress-Testing Financial Systems: An Overview of Current Methodologies

This paper reviews the state-of-the-art of macro stress-testing methodologies. Substantial progress has been made both in the econometric analysis of financial soundness indicators and in the simulation of value-at-risk measures to assess system-wide vulnerabilities. However, a number of methodological challenges still remain concerning the correlation of market and credit risks over time and across institutions, the limited time horizon generally used for the analysis and the potential instability of reduced-form parameter estimates because of feedback effects. Further research in this area might also focus on how to use macro stress-testing techniques as an operational tool to incorporate financial stability considerations into monetary policy decision-making.
When the atmosphere warms it rains and ice melts: seventh grade students’ conceptions of a climate system

Although many environmental and science educators have explored students’ conceptual understandings, misconceptions, and knowledge of the greenhouse effect, global warming, and climate change, few have investigated the ways students conceptualize climate as a system or how components of the system influence climate. Therefore, the purpose of this study was to begin the process of understanding how US students conceptualize a climate system. A total of 42 seventh grade students (ages 12–13) from the Midwest completed an open-response task. From the inductive analysis of student written responses, 22 codes emerged that reflected students’ conceptions of the climate system. From these codes, three path diagrams were constructed that illustrate these students’ conceptions about how a climate system influences climate and how greenhouse gases and global warming impact the climate system. A generalized model of students’ conception of a climate system was generated. Students in this study conceptualized a climate system in a unidirectional, linear, cause and effect relationship that emphasized the atmospheric component of the climate system.
Behavioral consequences of dopamine deficiency in the Drosophila central nervous system

The neuromodulatory function of dopamine (DA) is an inherent feature of nervous systems of all animals. To learn more about the function of neural DA in Drosophila, we generated mutant flies that lack tyrosine hydroxylase, and thus DA biosynthesis, selectively in the nervous system. We found that DA is absent or below detection limits in the adult brain of these flies. Despite this, they have a lifespan similar to WT flies. These mutants show reduced activity, extended sleep time, locomotor deficits that increase with age, and they are hypophagic. Whereas odor and electrical shock avoidance are not affected, aversive olfactory learning is abolished. Instead, DA-deficient flies have an apparently “masochistic” tendency to prefer the shock-associated odor 2 h after conditioning. Similarly, sugar preference is absent, whereas sugar stimulation of foreleg taste neurons induces normal proboscis extension. Feeding the DA precursor l-DOPA to adults substantially rescues the learning deficit as well as other impaired behaviors that were tested. DA-deficient flies are also defective in positive phototaxis, without alteration in visual perception and optomotor response. Surprisingly, visual tracking is largely maintained, and these mutants still possess an efficient spatial orientation memory. Our findings show that flies can perform complex brain functions in the absence of neural DA, whereas specific behaviors involving, in particular, arousal and choice require normal levels of this neuromodulator.
Dynamic Spectrum Management for Standardized VDSL

Dynamic spectrum management (DSM) improves the capacity utilization of twisted-pair cables by adapting the transmit power spectral density (PSD) of modems to the actual noise environment and channel conditions. Earlier proposed DSM algorithms do not take into account the standardized very high speed digital subscriber line (VDSL) constraints on the allowable transmit PSDs. However, VDSL modems support only restricted transmit PSD shapes resulting from the standardized power back-off (PBO) method, which is controlled by a small set of parameters. Furthermore, since all modems are currently using the same PBO parameters their bit rate performance is severely limited. In this paper, we show how to effectively exploit the standardized PBO concept for DSM to significantly boost bit rates. We also present a low complex DSM algorithm, the user unique PBO (UUPBO) algorithm, for calculating PBO parameters that are uniquely optimized for each modem.
On Perceptual Metaphors

Metaphors reflect processes of thinking and, consequently, appear not just in language but in perception as well. A notable example of metaphorical perception is synesthesia, in which music or voices may be perceived to have shapes, textures, or colors. Another example is physiognomic perception, in which dark objects may be perceived as gloomy or bright ones may be perceived as happy. Synesthetic perception and physiognomic perception alike reveal the presence of deep similarities across different sense modalities, and many of these similarities appear to be inherent to perception. In this regard, intersensory and physiognomic metaphors reflect "natural" rather than "conventional" symbols or signs. Despite their perceptual origin, however, metaphorical relations evident in synesthetic and physiognomic perception are also represented in and accessible through language. Consequently, in information processing tasks requiring people to identify or categorize perceptual stimuli, linguistic or abstract proces.
Temporal logic motion control using actor–critic methods

This paper considers the problem of deploying a robot from a specification given as a temporal logic statement about some properties satisfied by the regions of a large, partitioned environment. We assume that the robot has noisy sensors and actuators and model its motion through the regions of the environment as a Markov decision process (MDP). The robot control problem becomes finding the control policy which maximizes the probability of satisfying the temporal logic task on the MDP. For a large environment, obtaining transition probabilities for each state–action pair, as well as solving the necessary optimization problem for the optimal policy, are computationally intensive. To address these issues, we propose an approximate dynamic programming framework based on a least-squares temporal difference learning method of the actor–critic type. This framework operates on sample paths of the robot and optimizes a randomized control policy with respect to a small set of parameters. The transition probabilities are obtained only when needed. Simulations confirm that convergence of the parameters translates to an approximately optimal policy.
Click on a Cluster: A Viable Approach to Scale Software-Based Routers

Extensible software-based routers running on commodity off-the-shelf hardware and open-source operating systems have been motivated by the progress in hardware technologies and by the demand for routers with new capabilities. The Click modular router is one such software system. Click provides a mechanism to extend packet processing functions while supporting higher packet forwarding performance compared with other software-based routers. However the limitation of executing on a PC is in tension with the requirement for higher performance. In this paper, we explore the scalability of an extended version of Click that runs on a cluster of PCs connected by a high-speed/low latency InfiniBand interconnection network. We present the implementation and evaluation of our prototype. Our measurements show that the performance of this router can be scaled nearly linearly with increasing cluster size.
Book Reviews: The State of Research on Literacy

Research in a variety of fields has demonstrated that literacy is inextricably bound with economic, political, and religious issues and that societies (or groups within societies) become literate when the individual's or group's motivation to use literacy for some meaningful purpose intersects with society's willingness to facilitate related instruction. In other words, the context of literacy use plays a major role in shaping how literacy learning proceeds. Research in education, on the other hand, has often treated literacy primarily as a set of skills to be learned rather than as activities in which to engage. A separation of literacy skills from the societal uses to which they might conceivably be put has resulted. This has been accompanied by a pattern of research that focuses on the individual as literacy learner, rather than on the individual as a member of a discourse community with its own set of values, constraints, and knowledge that affects literacy learning. Attention to such social and communicative issues is, however, the driving force behind much current work in literacy in education, marking it as qualitatively different from the work of the past. JUDITH A. LANGER
Contemporary Issues in Sexual Orientation and Identity Development in Emerging Adulthood

Emerging adulthood presents a unique developmental milieu for sexual orientation and identity development. Over the past 10 years, a body of research has begun delineating contemporary emerging adults’ understandings of their sexual orientation and processes of sexual identity development. This scholarship has increasingly recognized the complexity and multidimensional nature of sexual identity development among both heterosexual and sexual-minority individuals. This review covers current conceptualizations of sexual orientation and identity, traditional and contemporary models of sexual identity development, and recent empirical literature assessing developmental trajectories, consistency between and within dimensions of sexual orientation and identity, stability of these dimensions, and issues of sexual identity labeling and categorization. This scholarship suggests that increased attention to diversity within and between sexual identity groups is warranted but also reveals notable patterns and categories that should be considered as the field moves forward.
Protein-DNA interactions at the major and minor promoters of the divergently transcribed dhfr and rep3 genes during the Chinese hamster ovary cell cycle

In mammals, two TATA-less bidirectional promoters regulate expression of the divergently transcribed dihydrofolate reductase (dhfr) and rep3 genes. In CHOC 400 cells, dhfr mRNA levels increase about fourfold during the G1-to-S phase transition of the cell cycle, whereas the levels of rep3 transcripts vary less than twofold during this time. To assess the role of DNA-binding proteins in transcriptional regulation of the dhfr and rep3 genes, the major and minor dhfr-rep3 promoter regions were analyzed by high-resolution genomic footprinting during the cell cycle. At the major dhfr promoter, prominent DNase I footprints over four upstream Sp1 binding sites did not vary throughout G1 and entry into the S phase. Genomic footprinting revealed that a protein is constitutively bound to the overlapping E2F sites throughout the G1-to-S phase transition, an interaction that is most evident on the transcribed template strand. On the nontranscribed strand, multiple changes in the DNase I cleavage pattern are observed during transit through G1 and entry into the S phase. By using gel mobility shift assays and a series of sequence-specific probes, two different species of E2F were shown to interact with the dhfr promoter during the cell cycle. The DNA binding activity of one E2F species, which preferentially recognizes the sequence TTTGGCGC, did not vary significantly during the cell cycle. The DNA binding activity of the second E2F species, which preferentially recognizes the sequence TTTCGCGC, increased during the G1-to-S phase transition. Together, these results indicate that Sp1 and the species of E2F that binds TTTGGCGC participate in the formation of a basal transcription complex, while the species of E2F that binds TTTCGCGC regulates dhfr gene expression during the G1-to-S phase transition. At the minor promoter, DNase I footprints at a consensus c-Myc binding site and three Sp1 binding sites showed little variation during the G1-to-S phase transition. In addition to protein binding at sequences known to be involved in the regulation of transcription, genomic footprinting of the entire promoter region also showed that a protein factor is constitutively bound to the first intron of the rep3 gene.
Triglycerides: a case for treatment?

Purpose of review To discuss the relevance of triglycerides to cardiovascular disease (CVD) risk. Recent findings Triglycerides are a commonly measured component of lipid profiles. Raised triglycerides are a component of the metabolic syndrome and are strongly associated with future risk of diabetes as well as cardiovascular disease. Triglyceride-rich particles form a component of cardiovascular risk above that delineated by low density lipoprotein (LDL) cholesterol. Elevated triglycerides are a marker of atherogenic small dense LDL, excess baseline and residual CVD risk even after statin therapy. Additional methods to lower triglycerides include niacin, fibrates and omega-3 fatty acids. Trials in monotherapy with both niacin and fibrates suggest some benefit in reducing CVD events based on evidence mostly derived from older studies. However, endpoint trials of adding either niacin or fenofibrate to statins have not shown any benefit, except possibly in patients with an increased atherogenic index (triglyceride : HDL-C ratio), or have been underpowered. Trials of omega-3 fatty acids have been performed at doses insufficient to affect lipid profiles in populations with inadequate control of LDL-C but did reduce CVD events. Summary Further trials of lipid-lowering agents beyond statins will be required in patients with LDL-C adequately controlled on statin therapy.
A process analysis of linguistic change

In this paper a process analysis of linguistic change is shown through the methodology of task analysis. From the linguistic therapy of evaluation will be shown the relevance of an intensional orientation for human evaluation problems and the relevance of an extensional orientation for more proper evaluations, along with some other therapeutic operations which represent how human beings use language and how language's use is modified with one of the main techniques of the linguistic therapy of evaluation: the abstraction orders. Also the relevance for the evolvement of cognitive psychotherapy of following a process research methodology will be discussed and addressed. The state of the art of cognitive psychotherapy will be greatly influenced by process research methodology which helps us to delineate the process of change and that combined with outcome research will improve our cognitive theories and methods.
Ras-dependent Mitogen-activated Protein Kinase Activation by G Protein-coupled Receptors

Many receptors that couple to heterotrimeric guanine-nucleotide binding proteins (G proteins) have been shown to mediate rapid activation of the mitogen-activated protein kinases Erk1 and Erk2. In different cell types, the signaling pathways employed appear to be a function of the available repertoire of receptors, G proteins, and effectors. In HEK-293 cells, stimulation of either α1B- or α2A-adrenergic receptors (ARs) leads to rapid 5–10-fold increases in Erk1/2 phosphorylation. Phosphorylation of Erk1/2 in response to stimulation of the α2A-AR is effectively attenuated by pretreatment with pertussis toxin or by coexpression of a Gβγ subunit complex sequestrant peptide (βARK1ct) and dominant-negative mutants of Ras (N17-Ras), mSOS1 (SOS-Pro), and Raf (ΔN-Raf). Erk1/2 phosphorylation in response to α1B-AR stimulation is also attenuated by coexpression of N17-Ras, SOS-Pro, or ΔN-Raf, but not by coexpression of βARK1ct or by pretreatment with pertussis toxin. The α1B- and α2A-AR signals are both blocked by phospholipase C inhibition, intracellular Ca2+chelation, and inhibitors of protein-tyrosine kinases. Overexpression of a dominant-negative mutant of c-Src or of the negative regulator of c-Src function, Csk, results in attenuation of the α1B-AR- and α2A-AR-mediated Erk1/2 signals. Chemical inhibitors of calmodulin, but not of PKC, and overexpression of a dominant-negative mutant of the protein-tyrosine kinase Pyk2 also attenuate mitogen-activated protein kinase phosphorylation after both α1B- and α2A-AR stimulation. Erk1/2 activation, then, proceeds via a common Ras-, calcium-, and tyrosine kinase-dependent pathway for both Gi- and Gq/11-coupled receptors. These results indicate that in HEK-293 cells, the Gβγ subunit-mediated α2A-AR- and the Gαq/11-mediated α1B-AR-coupled Erk1/2 activation pathways converge at the level of phospholipase C. These data suggest that calcium-calmodulin plays a central role in the calcium-dependent regulation of tyrosine phosphorylation by G protein-coupled receptors in some systems.
Evaluation of the Cytogenetic Status of Human Lymphocytes After Exposure to a High Concentration of Bee Venom In Vitro

Evaluation of the Cytogenetic Status of Human Lymphocytes After Exposure to a High Concentration of Bee Venom In Vitro Several studies have reported radioprotective, antimutagenic, anti-inflammatory, antinociceptive, and anticancer effects of bee venom both in the cell and the whole organism. The aim of this study was to assess the effects of a single high dose of 100 μg mL-1 of whole bee venom in human lymphocytes in vitro over a variety of time spans (from 10 min to 24 h). After the treatment, we used the comet assay and micronucleus test to see the effect of bee venom on the cell. The comet assay confirmed that the venom damaged the DNA molecule. Tail length, tail intensity, tail moment showed a significant increase (P<0.05). The percentage of long-tailed nuclei (LTN) with the tail length exceeding the 95th percentile also increased in a time-dependent manner. The micronucleus parameters (number of micronuclei, nucleoplasmic bridges, and nuclear buds) also showed a significant time-dependent increase (P<0.05). This research indicates that high concentrations of bee venom can lead to cellular instability. Further research is needed to understand the mechanism of action of bee venom and its components in human cells and to see if this natural product may find application in medicine. Procjena citogenetičkog statusa u ljudskim limfocitima nakon izloženosti visokim koncentracijama pčelinjeg otrova u uvjetima in vitro Cilj ovog istraživanja je procjena staničnog statusa ljudskih limfocita periferne krvi nakon tretmana visokom koncentracijom pčelinjeg otrova u in vitro uvjetima primjenom alkalnog kometnog testa i mikronukleusnog testa. Limfociti su bili izloženi pčelinjem otrovu u koncentraciji od 100 μg mL-1 u različitom vremenu (od 10 min do 24 h). Rezultati kometnog testa upućuju na oštećenje molekule DNA povećanjem parametara kometnog testa (dužina repa, intenzitet repa i repni moment) te prisutnost limfocita s visokom učestalosti kometa s dugim repovima (LTN). U tim stanicama učestalost LTN premašuje 95% ukupne raspodjele vrijednosti LTN dobivene za sve stanice kontrolnog uzorka. Parametri mikronukleusnog testa (broj mikronukleusa, nukleoplazmatski mostovi i nuklearni pupovi) također pokazuju značajan porast u odnosu na odgovarajući kontrolni uzorak (P<0,05). Rezultati dobiveni ovim tehnikama upućuju na to da pčelinji otrov u visokoj koncentraciji uzrokuje staničnu nestabilnost te na potrebu daljnjih istraživanja mehanizama djelovanja pčelinjeg otrova i njegovih sastavnica na ljudske stanice u svrhu primjene prirodnih spojeva posebice u medicinskoj praksi.
Voices of Dissent in the Iraq War: Moving from Deviance to Legitimacy?

Using indexing theory as a framework, this content analysis of 2003–2007 Time coverage explores the range of dissenting voices of the war in news dialogue. Findings show that war criticism remained constant throughout the years and was largely targeted toward the Bush administration. While most dissent originated from official sources, American and Iraqi civilians did have space to voice their dissatisfaction. Journalists themselves became increasingly vocal in their condemnation of the war. These results suggest that clashes between public opinion and official perspectives have implications in news coverage and promotion of debate about current affairs.