Miracle-dz/UniFAR-FTUs huggingface dataset:
Regulation of Escherichia coli aspartate transcarbamylase synthesis by guanosine tetraphosphate and pyrimidine ribonucleoside triphosphates

The effects of guanosine tetraphosphate (ppGpp) and pyrimidine ribonucleoside triphosphates on Escherichia coli aspartate transcarbamylase (ATCase) synthesis were examined. To determine the effect of ppGpp, a stringent (relA+) and relaxed (relA) isogenic pair of E. coli K-12 strains was starved for isoleucine, and the residual rate of synthesis of this enzyme was measured. It was necessary to starve the strains for uracil before the isoleucine limitation to maintain similar, low levels of UTP, the putative pyrimidine effector of ATCase synthesis. The isoleucine starvation of the stringent strain caused an immediate 10-fold increase in the intracellular concentration of ppGpp, which was coincident with the cessation of the synthesis of the enzyme. The elevated level of ppGpp then decayed until it reached an intracellular concentration similar to that found in unstarved cells. Enzyme synthesis resumed at this time. In the relaxed strain, the intracellular concentration of ppGpp did not increase upon isoleucine starvation and synthesis of the enzyme was not repressed. These experiments strongly indicated that ppGpp acts as a negative effector of ATCase synthesis. The repression of ATCase synthesis by ppGpp was demonstrated directly by using a Salmonella typhimurium (relA) in vitro coupled transcription-translation system with a lambda specialized transducing phage carrying the E. coli K-12 operon encoding the subunits of this enzyme (pyrBI) as a source of DNA. This in vitro system was also used to measure the effects of UTP and CTP on ATCase synthesis. Increasing the concentration of UTP in the in vitro reaction mixture resulted in strong repression of this synthesis, whereas increasing the CTP concentration did not affect synthesis significantly. Possible mechanisms for the regulation of pyr gene expression, including attenuation control, are discussed.
The renal clearance of cefuroxime and ceftazidime and the effect of probenecid on their tubular excretion.

1. The renal tubular excretion of cefuroxime and ceftazidime in relation to the coadministration of probenecid was investigated in eight and two healthy subjects, respectively. 2. Cefuroxime or ceftazidime were administered by i.v. infusion and 1 g probenecid was administered orally after steady state plasma concentrations of the cephalosporin were reached. 3. In a second session the same antibiotic was administered at increasing infusion rates such that three different levels of plasma drug concentration were achieved. 4. The renal clearance of antibiotic was calculated based upon unbound plasma concentration, and tubular clearance was estimated by subtracting inulin clearance from the renal clearance of the antibiotic. 5. Non-linear regression analysis was used to estimate parameters describing the saturability of tubular excretion and the effect of probenecid inhibition, i.e. EC50 and Rtub,max, could be established for cefuroxime: EC50 was 248 (s.d. 130) mg l-1 and Rtub,max was 1.852 (s.d. 0.577) mg h-1. Tubular excretion of ceftazidime was practically zero. The EC50 of probenecid for inhibition of the tubular excretion of cefuroxime was 0.80 (s.d. 0.31) mg l-1. 6. The results indicate that in the therapeutic plasma concentration range of cefuroxime its renal clearance is not saturated. Probenecid at therapeutic doses will block tubular excretion of cefuroxime almost completely.
The Feasibility of Inserting Atlas Lateral Mass Screws via the Posterior Arch

Study Design. A total of 709 skeletally mature atlas specimens were obtained from the Hamann Todd Collection at the Cleveland Museum of Natural History. Using digital caliper, the thickness of the vertebral artery groove was measured to determine the feasibility of potential screw placement. Objective. To determine the feasibility of screw insertion into the atlas lateral mass via the posterior arch. Summary of Background Data. The originally described starting point for atlas lateral mass screws, at the base of the lateral mass, can be associated with excessive bleeding and irritation of the greater occipital nerve. In order to avoid such problems, we routinely start the screw at a more cranial location on the dorsal, posterior-lateral arch of the atlas, when the anatomy permits. In cases where the arch is too small, we notch the undersurface of the arch so as to recess the screw into the notch. We undertook this cadaveric morphometric study to determine the feasibility of using such techniques in the general population. Methods. A total of 709 atlas specimens were measured bilaterally to determine the thickness of the posterior-lateral arch at the level of the lateral mass. The presence of the ponticulus posticus was recorded as well. Results. The average minimal thickness of the posterior-lateral atlas was 3.95 mm. There was a total of 157 complete and 34 incomplete ponticuli posticus. Overall, 85.2% of the specimens had a thickness greater than 3 mm, 654 (46.2%) greater than 4 mm, and 194 (13.7%) greater than 5 mm. Conclusions. Our results suggest that although only a small percentage of patients can accept a screw that is directly inserted via the posterior-lateral arch into the lateral mass, the notching technique is possible in the vast majority of patients. To our knowledge, this is the largest study to examine the possibility of using the posterior-lateral arch as the starting point for these screws. Our results suggest that alternative starting points for these screws are possible in a large percentage of the cases.
Donor Site Morbidity and Return to the Preinjury Activity Level after Anterior Cruciate Ligament Reconstruction Using Ipsilateral and Contralateral Patellar Tendon Autograft

Aim To compare the donor site morbidity after anterior cruciate ligament reconstruction using ipsilateral and contralateral bone–patellar tendon autograft. Study Design Cohort study; Level of evidence, 2 Patients and Method Between 1997 and 1999, 100 patients underwent anterior cruciate ligament reconstruction with autologous bone–patellar tendon graft. The reconstructions were performed using ipsilateral bone–patellar tendon graft in 52 patients (group Ip) and contralateral bone–patellar tendon graft in 48 patients (group Co). Group Co consisted of 2 subgroups: group Co-D consisted of the donor knees (n = 48) and group Co-ACL consisted of the anterior cruciate ligament–reconstructed knees (n = 48). Mean follow-up was 39.2 months. Donor site morbidity was evaluated with a questionnaire, computerized historical data, KT-2000 arthrometer measurements, the Cincinnati score, and the Tegner score. Results KT-2000 arthrometer evaluation showed a mean side-to-side difference of 0.6 mm in both groups. There were no significant differences between the 2 groups concerning the Cincinnati and Tegner scores. With regard to local tenderness, a significantly higher rate was found in group Ip (59.6%) and group Co-D (58.3%) compared with group Co-ACL (6.3%). In groups Ip and Co-D, high statistically significant differences were also found according to kneeling pain (69.2% and 70.8%, respectively) and knee-walking pain (76.9% and 70.8%, respectively) compared with group Co-ACL (6.3% and 10.4%, respectively). With regard to numbness, there was no statistical significance between the rates of all 3 groups: group Ip = 75%, group Co-D = 85.4%, and group Co-ACL = 64.6%. There was one rupture of the patellar tendon and one patient with chronic patellar tendinitis, both in the donor knee of group Co-D. Conclusion The contralateral bone–patellar tendon graft appears to present no advantage over the ipsilateral graft, as all symptoms concerning donor site morbidity are shifted from the injured into the healthy knee, and return to activity is not more rapid.
Can Investors Anticipate Post-IPO Mergers and Acquisitions?

Given the frequency and value implications of post-IPO merger and acquisition activity, we investigate empirically whether investors can utilize information based on IPO deal structure to predict merger and acquisition activity among newly public firms. Consistent with the hypothesis that some firms conduct IPOs to facilitate future M&A activity, we find that aspects of IPO deal structure predict whether a newly public firm subsequently becomes a bidder or target. These characteristics include underwriter quality, promotional activity, pricing, proceeds, ownership structure, and issuance activity suggestive of market timing. Investors appear to rely on these observable aspects of a firm's going public process to anticipate the implications of M&A activity for security valuation. Specifically, when newly public firms with IPO deal structures predictive of acquisition activity announce an acquisition their stock returns are indistinguishable from zero. In contrast, abnormal returns to acquisition announcements by unlikely or surprise bidders are positive on average. These results suggest that the going public process has important implications for future M&A activity and valuation.
Preparation and characterization of nanosized ZnGa/sub 2-x/Cr/sub x/O4 phosphors

Cr-doped zinc gallate phosphors were prepared via citric gel route and their luminous properties were characterized by photoluminescence in this study. From the results of XRD studies, it was found that spinel phase formed exclusively in the ZnGa/sub 2-x/Cr/sub x/O/sub 4/ phosphors (O /spl les/ x /spl les/ 0.010) prepared by heat-treatment at 700/spl deg/C for 5 hours and the lattice constant increased linearly from 8.36 to 8.38 /spl Aring/ with the amount of Cr/sup 3+/-doping. The photoluminescence studies manifested that the absorbance at wavelengths of 437 and 580 nm. All of the prepared phosphors exhibit the characteristic emission peaks at wavelengths of 669, 680, 688, 694, 708, and 713 nm independent of the amount of Cr/sup 3+/-doping as they were excited with lights of wavelengths of 437 and 580 nm.
European report on preventing child maltreatment.

child maltreatment is a leading cause of health inequality, with the socioeconomically disadvantaged more at risk. It worsens inequity and perpetuates social injustice because of its far-reaching health and development consequences. In spite of child maltreatment being a priority in most countries in the WHO European Region, few have devoted adequate resources and attention to its prevention. this report outlines the high burden of child maltreatment, its causes and consequences and the cost−effectiveness of prevention programmes. It makes compelling arguments for increased investment in prevention and for mainstreaming prevention objectives into other areas of health and social policy, reflecting the whole-of-society approach promoted by Health 2020 and the need for increased intersectoral working and coordination. the report offers policy-makers a preventive approach based on strong evidence and shared experience to support them in responding to increased demands from the public to tackle child maltreatment. Prevention programmes that stop maltreatment from occurring in the first place and reduce children’s exposure to adversity have wide-ranging public health and societal benefits.
Reflecting on the Challenges of Informal Contexts: Early Field Experiences With Technology in Teacher Education

Early field experiences, or those that come early in a teacher’s preparation before more formalized opportunities like practicum and student teaching, can provide a venue for pre service teachers to practice technology-specific instructional decision-making and reflective practice. Although research exists on the potential roles of field experiences in teacher education, little research exists on early field experiences, especially those taking place in informal contexts. Moreover, little research exists examining how those early field experiences in informal spaces might shape preservice teachers’ use of digital learning tools. To address this gap, an inquiry was conducted to better understand teachers’ early field work experiences in informal science contexts and the use of formative assessment technologies. Researchers used a mixed methods design to examine how early field experiences might support authentic and robust opportunities for teachers in training. Results suggested that technology-focused early field experiences can serve as confirmatory events for preservice teachers, afford them opportunities to apply theory and content knowledge to practice, and contend with issues related to technology integration, instructional planning, classroom management, and even attendance within an informal context. Findings could be used to improve the design of early field experiences for preservice teachers, and facilitate the scaffolding of the opportunities to help them better integrate technologies into those experiences.
Structure of Income Inequality and Household Leverage: Theory and Cross-Country Evidence

How does income inequality and its structure affect credit? We extend the theoretical framework by Kumhof et al. (2015) to distinguish between upper, middle and low-income classes, and show that most of the positive impact of inequality on credit predicted by Kumhof et al. (2015) should be driven by the share of total output owned by the middle classes. Consistently, this impact should weaken in countries where financial markets are insufficiently developed. These theoretical predictions are empirically confirmed by a study based on a 41-country dataset over the period 1970-2014, where exogenous variations of inequality are identified with a new instrument variable, the total number of ILO conventions signed at the country-level.
The Distributional Hypothesis

Distributional approaches to meaning acquisition utilize distributional properties of linguistic entities as the building blocks of semantics. In doing so, they rely fundamentally on a set of assumptions about the nature of language and meaning referred to as the distributional hypothesis. This hypothesis is often stated in terms like “words which are similar in meaning occur in similar contexts” (Rubenstein & Goodenough, 1965); “words with similar meanings will occur with similar neighbors if enough text material is available” (Schutze & Pedersen, 1995); “a representation that captures much of how words are used in natural context will capture much of what we mean by meaning” (Landauer & Dumais, 1997); and “words that occur in the same contexts tend to have similar meanings” (Pantel, 2005), just to quote a few representative examples. The general idea behind the distributional hypothesis seems clear enough: there is a correlation between distributional similarity and meaning similarity, which allows us to utilize the former in order to estimate the latter. However, one can pose two very basic questions concerning the distributional hypothesis. The first is what kind of distributional properties we should look for, and what — if any — the differences are between different kinds of distributional properties. Looking at algorithms for distributional meaning acquisition we can discern two distinct approaches. The first is to build distributional profiles for words based on which other words surround them, as exemplified by Schutze (1992) and the Hyperspace Analogue to Language (HAL) model (Lund, Burgess, & Atchley, 1995). The second is to build distributional profiles based on in which text regions words occur, as exemplified by the Latent Semantic Analysis (LSA) model (Landauer & Dumais, 1997). These approaches are often treated as functionally equivalent when it comes to representing meaning similarities, despite the fact that they are based on different types of distributional raw materials. The second question is in what sense it is meaning that is conveyed by distributional patterns. Proponents of distributional methods often seem comfortable to ascribe meaning to distributional representations without explaining
The Roles of ROS and ABA in Systemic Acquired Acclimation[OPEN]

Systemic responses to environmental stimuli are essential for the survival of multicellular organisms. In plants, they are initiated in response to many different signals including pathogens, wounding, and abiotic stresses. Recent studies highlighted the importance of systemic acquired acclimation to abiotic stresses in plants and identified several different signals involved in this response. These included reactive oxygen species (ROS) and calcium waves, hydraulic waves, electric signals, and abscisic acid (ABA). Here, we address the interactions between ROS and ABA at the local and systemic tissues of plants subjected to abiotic stress and attempt to propose a model for the involvement of ROS, ABA, and stomata in systemic signaling leading to systemic acquired acclimation.
GABAB receptor‐mediated inhibition of the neurogenic vasopressor response in the pithed rat 1

1 The effects of γ‐aminobutyric acid (GABA) and related drugs on the vasopressor response induced by electrical stimulation (single pulse of 30 V and 1 ms) of the preganglionic sympathetic nerve fibres or by injection of noradrenaline 0.3 nmol kg−1 were studied in the pithed rat. 2 The electrically‐induced increase in diastolic blood pressure was inhibited by GABA and the GABAB‐receptor agonist R‐(−)−baclofen but was not affected by its S‐(+)‐enantiomer and by the GABAA‐receptor agonists muscimol and 3‐aminopropane sulphonic acid. 3 The dose‐response curve of R‐(−)−baclofen for its inhibitory effect on the electrically‐induced vasopressor response was shifted to the right by the GABAB‐receptor antagonist 2‐hydroxysaclofen, but was not affected by the GABAA‐receptor antagonist bicuculline. 2‐Hydroxysaclofen and bicuculline by themselves did not affect the electrically‐induced vasopressor response. 4 The increase in diastolic blood pressure induced by exogenous noradrenaline was not affected by the GABA‐related drugs, which also had no (or very slight) effects on the basal diastolic blood pressure. 5 It is concluded that GABA inhibits catecholamine release in the resistance vessels of the rat via GABAB‐receptors, probably located presynaptically on the postganglionic sympathetic nerve fibres.
Breaking the silence and saving lives: young peoples sexual and reproductive health in the Arab States and Iran.

This review of young peoples sexual and reproductive health (YPSRH) and gender issues affecting young people ages 10--24 in 19 Arab States and the Islamic Republic of Iran (hereafter referred to as Iran) was undertaken to: 1) strengthen the knowledge base on YPSRH including gender issues and on the regional programme and policy context; 2) provide recommendations for national YPSRH and gender policies and programmes based on evidence from international programmes and regional data; and 3) identify gaps in the knowledge base on YPSRH and gender issues in the region and recommend research priorities. The authors and three research assistants conducted: 1) a YPSRH literature review globally and from the 20 specified countries; 2) policy analyses related to the countries compliance with international human rights treaties and agreements on issues related to YPSRH and gender; 3) interviews with international and regional experts; 4) interviews with and email surveys of national programme professionals. (excerpt)
Performance Degradation of High-Brightness Light Emitting Diodes Under DC and Pulsed Bias

This paper presents the results of an experimental investigation of the performance of commercially available high-brightness light emitting diodes (HBLEDs). Three different families of white HBLEDs from three different manufacturers are considered. The main issues taken into account and reported in detail are the following: quality of the emitted light, impact of the driving strategy on the expected device lifetime, thermal management and related aging effects. The execution of a large number of accelerated stress tests reveals the weaknesses of the technology with respect to thermal degradation and the sensitivity of the device performance degradation to the adopted driving strategy. Furthermore, square-wave driving has been compared to conventional dc driving in terms of device performance and reliability. Comparison has been carried out for the same average current value of the driving waveforms. It has been found that square-wave driving can be an effective alternative to dc driving in terms of device efficiency only for high duty cycles. For low duty cycles, worse performance was detected due to the saturation of efficiency at high peak current levels. Reliability tests did not univocally indicate whether the use of pulsed bias can be more convenient than dc driving in terms of lumen maintenance. The three families of devices submitted to dc and pulsed stresses showed different behaviors, indicating that stress kinetics strongly depends on the LED technological structure and package thermal design.
The Inhibitor Ko143 Is Not Specific for ABCG2

Imaging ATP-binding cassette (ABC) transporter activity in vivo with positron emission tomography requires both a substrate and a transporter inhibitor. However, for ABCG2, there is no inhibitor proven to be specific to that transporter alone at the blood-brain barrier. Ko143 [[(3S,6S,12aS)-1,2,3,4,6,7,12,12a-octahydro-9-methoxy-6-(2-methylpropyl)-1,4-dioxopyrazino[1′,2′:1,6]pyrido[3,4- b]indole-3-propanoic acid 1,1-dimethylethyl ester], a nontoxic analog of fungal toxin fumitremorgin C, is a potent inhibitor of ABCG2, although its specificity in mouse and human systems is unclear. This study examined the selectivity of Ko143 using human embryonic kidney cell lines transfected with ABCG2, ABCB1, or ABCC1 in several in vitro assays. The stability of Ko143 in rat plasma was measured using high performance liquid chromatography. Our results show that, in addition to being a potent inhibitor of ABCG2, at higher concentrations (≥1 μM) Ko143 also has an effect on the transport activity of both ABCB1 and ABCC1. Furthermore, Ko143 was found to be unstable in rat plasma. These findings indicate that Ko143 lacks specificity for ABCG2 and this should be taken into consideration when using Ko143 for both in vitro and in vivo experiments.
China Trade Expansion: A Case Study of Vietnam

Vietnam encountered the unexpected trade deficit with China in the recent years. Upon establishment of the ASEAN Economic Community on December 31st, 2015, the import tax rates of the regional countries have been reduced significantly. This facilitates the quality goods from the ASEAN countries overflowing into Vietnam. Nevertheless, a few research and analysis on the challenge of importing goods from China under the regional economic integration. To settle these issues, this paper analyzes the China’s market expansion into Vietnam. In addition, it also compares the Vietnam’s import structure from China and other countries in ASEAN. The results showed that China is always the top export partner of Vietnam, particularly, machinery and raw materials
Vagal stimulation for heart failure

Purpose of review On the very solid background of experimental and clinical studies pointing to the cardiovascular risks associated with depressed vagal reflexes and supported by specific experiments in animal models of heart failure, we are witnessing a rapidly growing interest in the very untraditional approach to the management of heart failure represented by chronic vagal stimulation. Recent findings Additional studies have been performed using vagal stimulation in animal models of heart failure showing that benefit can occur even in the absence of heart rate changes. The first in-man studies of chronic vagal stimulation have been performed, first as a single center and then as a small multicenter study with favorable results in terms of feasibility, safety, and efficacy. Summary The initial observations with chronic vagal stimulation in man, though limited by very small numbers, are very encouraging and seem to open new paths, or perhaps avenues, for the management of symptomatic heart failure. This transition between experimental and clinical approaches represents an exciting example of translational research.