Miracle-dz/UniFAR-FTUs huggingface dataset:
Fatty acids in arbuscular mycorrhizal fungi are synthesized by the host plant

Lipid transfer provides symbiotic fungi associated with plant roots with a source of carbon. Food for fungi A wide variety of plants form symbiotic relationships in their roots with arbuscular mycorrhizal fungi. The fungi channel inorganic and micronutrients from soil to the plant, and the plant supplies the fungi with organic nutrients. Jiang et al. and Luginbuehl et al. found that as part of this exchange, the plant supplies lipids to its symbiotic fungi, thus providing the fungi with a robust source of carbon for their metabolic needs. Science, this issue p. 1172; p. 1175 Plants form beneficial associations with arbuscular mycorrhizal fungi, which facilitate nutrient acquisition from the soil. In return, the fungi receive organic carbon from the plants. The transcription factor RAM1 (REQUIRED FOR ARBUSCULAR MYCORRHIZATION 1) is crucial for this symbiosis, and we demonstrate that it is required and sufficient for the induction of a lipid biosynthetic pathway that is expressed in plant cells accommodating fungal arbuscules. Lipids are transferred from the plant to mycorrhizal fungi, which are fatty acid auxotrophs, and this lipid export requires the glycerol-3-phosphate acyltransferase RAM2, a direct target of RAM1. Our work shows that in addition to sugars, lipids are a major source of organic carbon delivered to the fungus, and this is necessary for the production of fungal lipids.
An excess of massive stars in the local 30 Doradus starburst

Observing more massive stars The number of stars that form at each mass is known as the initial mass function (IMF). For most masses, the IMF follows a power-law distribution, first determined by Edwin Salpeter in 1955. Schneider et al. used observations of the nearby star-forming region 30 Doradus (also known as the Tarantula Nebula) and combined these with stellar modeling to determine its IMF. They found more stars above 30 solar masses than predicted by the Salpeter distribution. Because the most massive stars also have the biggest influence on their surroundings—for instance, through ultraviolet radiation, stellar winds, supernova explosions, and production of heavy elements—this excess will have wide-ranging implications. Science, this issue p. 69 Observations of a star-forming region show that more stars form in excess of 30 solar masses than predicted by standard models. The 30 Doradus star-forming region in the Large Magellanic Cloud is a nearby analog of large star-formation events in the distant universe. We determined the recent formation history and the initial mass function (IMF) of massive stars in 30 Doradus on the basis of spectroscopic observations of 247 stars more massive than 15 solar masses (M☉). The main episode of massive star formation began about 8 million years (My) ago, and the star-formation rate seems to have declined in the last 1 My. The IMF is densely sampled up to 200 M☉ and contains 32 ± 12% more stars above 30 M☉ than predicted by a standard Salpeter IMF. In the mass range of 15 to 200 M☉, the IMF power-law exponent is 1.90−0.26+0.37, shallower than the Salpeter value of 2.35.
Double-trap measurement of the proton magnetic moment at 0.3 parts per billion precision

Nailing down the proton magnetic moment Fundamental physical laws are believed to remain the same if subjected to three simultaneous transformations: flipping the sign of electric charge, taking a mirror image, and running time backward. To test this charge, parity, and time-reversal (CPT) symmetry, it is desirable to know the fundamental properties of particles such as the proton to high precision. Schneider et al. used a double ion trap to determine the magnetic moment of a single trapped proton to a precision of 0.3 parts per billion. Comparatively precise measurements of the same quantity in the antiproton are now needed for a rigorous test of CPT symmetry. Science, this issue p. 1081 An optimized double–Penning trap technique improves the precision measurement of the proton magnetic moment by a factor of 11. Precise knowledge of the fundamental properties of the proton is essential for our understanding of atomic structure as well as for precise tests of fundamental symmetries. We report on a direct high-precision measurement of the magnetic moment μp of the proton in units of the nuclear magneton μN. The result, μp = 2.79284734462 (±0.00000000082) μN, has a fractional precision of 0.3 parts per billion, improves the previous best measurement by a factor of 11, and is consistent with the currently accepted value. This was achieved with the use of an optimized double–Penning trap technique. Provided a similar measurement of the antiproton magnetic moment can be performed, this result will enable a test of the fundamental symmetry between matter and antimatter in the baryonic sector at the 10−10 level.
Reducing the parallel complexity of certain linear programming problems

The parallel complexity of solving linear programming problems is studied in the context of interior point methods. If n and m, respectively, denote the number of variables and the number of constraints in the given problem, an algorithm that solves linear programming problems in O((mn)/sup 1/4/ (log 1 n)/sup 3/L) time using O(M(n)m/n+1n/sup 3/) processors is given. (M(n) is the number of operations for multiplying two n*n matrices). This gives an improvement in the parallel running time for n=o(m). A typical case in which n=o(m) is the dual of the uncapacitated transportation problem. The algorithm solves the uncapacitated transportation problem in O((VE)/sup 1/4/(log V)/sup 3/ (log V gamma )) time using O(V/sup 3/) processors, where V (E) is the number of nodes (edges) and gamma is the largest magnitude of an edge cost or a demand at a node. As a by-product, a better parallel algorithm for the assignment problem for graphs of moderate density is obtained. <<ETX>>
An AI stereotype catcher

An artificial intelligence method identifies implicit human biases such as gender stereotypes Those who converse regularly with their smartphones know that the language skills of computing devices have emerged from a lengthy childhood. On page 183 of this issue, Caliskan et al. unveil a new language achievement of artificial intelligence (AI) (1). In large bodies of English-language text, they decipher content corresponding to human attitudes (likes and dislikes) and stereotypes. In addition to revealing a new comprehension skill for machines, the work raises the specter that this machine ability may become an instrument of unintended discrimination based on gender, race, age, or ethnicity.
Emission of volatile organic compounds from petunia flowers is facilitated by an ABC transporter

Active transport of aromas Volatile organic compounds (VOCs) serve as invisible lines of communication among host plants, pathogens, commensals, community groups, and, with flowers, their pollinators. Studying petunia flowers, Adebesin et al. show that VOCs do not passively diffuse out of the cells but are actively shuttled across the plasma membrane by an ABC (ATP-binding cassette) transporter (see the Perspective by Eberl and Gershenzon). Disabling the transporter results in damage to the cell's membranes by intracellular accumulation of VOCs. Science, this issue p. 1386; see also p. 1334 Rather than simply diffusing out of cells, volatile organic compounds in petunias require an active transporter. Plants synthesize a diversity of volatile molecules that are important for reproduction and defense, serve as practical products for humans, and influence atmospheric chemistry and climate. Despite progress in deciphering plant volatile biosynthesis, their release from the cell has been poorly understood. The default assumption has been that volatiles passively diffuse out of cells. By characterization of a Petunia hybrida adenosine triphosphate–binding cassette (ABC) transporter, PhABCG1, we demonstrate that passage of volatiles across the plasma membrane relies on active transport. PhABCG1 down-regulation by RNA interference results in decreased emission of volatiles, which accumulate to toxic levels in the plasma membrane. This study provides direct proof of a biologically mediated mechanism of volatile emission.
11β-Hydroxysteroid dehydrogenase Type 1 activity in lean and obese males with Type 2 diabetes mellitus

Glucocorticoids play an important role in the pathogenesis of obesity and insulin resistance. Impaired conversion of cortisone (E) to cortisol (F) by the type 1 isoenzyme of 11β-hydroxysteroid dehydrogenase (11β-HSD) in obesity may represent a protective mechanism preventing ongoing weight gain and glucose intolerance. We have studied glucocorticoid metabolism in 33 male subjects with type 2 diabetes mellitus [age, 44.2 ± 13 yr; body mass index (BMI), 31.1 ± 7.5 kg/m2 (mean ± sd)] and 38 normal controls (age, 41.4 ± 14 yr; BMI, 38.2 ± 12.8 kg/m2). Circulating F:E ratios were elevated in the diabetic group and correlated with serum cholesterol and homeostasis model assessment-S. There was no difference in 11β-HSD1 activity between diabetic subjects and controls. In addition, 11β-HSD1 activity was unaffected by BMI in diabetic subjects. However, in control subjects, increasing BMI was associated with a reduction in the urinary tetrahydrocortisol+5α-tetrahydrocortisol:tetrahydrocortisone ratio (P < 0.05) ind.
Lovastatin Inhibits Gap Junctional Communication in Cultured Aortic Smooth Muscle Cells

Background: Gap junctions, which serve as intercellular channels that allow the passage of ions and other small molecules between neighboring cells, play an important role in vital functions, including the regulation of cell growth, differentiation, and development. Statins, the 3-hydroxy-3-methylglutaryl-coenzymeA (HMG-CoA) reductase inhibitors, have been shown to inhibit the migration and proliferation of smooth muscle cells (SMCs) leading to an antiproliferative effect. Recent studies have shown that statins can reduce gap junction protein connexin43 (Cx43) expression both in vivo and in vitro. However, little work has been done on the effects of statins on gap junctional intercellular communication (GJIC). We hypothesized in this study that lovastatin inhibits vascular smooth muscle cells (VSMCs) migration through the inhibition of the GJIC. Methods: Rat aortic SMCs (RASMCs) were exposed to lovastatin. Vascular smooth muscle cells migration was then assessed with a Transwell migration assay. Gap junctional intercellular communication was determined by using fluorescence recovery after photobleaching (FRAP) analysis, which was performed with a laser-scanning confocal microscope. Results: The migration of the cultured RASMCs were detected by Transwell system. Cell migration was dose-dependently inhibited with lovastatin. Compared with that in the control (110 ± 26), the number of migrated SMCs was significantly reduced to 72 ± 24 (P < .05), 62 ± 18 (P < .01), and 58 ± 19 (P < .01) at the concentration of 0.4, 2, and 10 umol/L, per field. The rate of fluorescence recovery (R) at 5 minutes after photobleaching was adopted as the functional index of GJIC. The R- value of cells exposed to lovastatin 10 umol/L for 48 hours was 24.38% ± 4.84%, whereas the cells in the control group had an R- value of 36.11% ± 10.53%, demonstrating that the GJIC of RASMCs was significantly inhibited by lovastatin (P < .01). Smaller concentrations of lovastatin 0.08 umol/L did not change gap junction coupling (P > .05). Conclusions: These results suggest that lovastatin inhibits migration in a dose-dependent manner by attenuating JIC. Suppression of gap junction function could add another explanation of statin-induced antiproliferative effect.
Impact of Angiotensin-Converting Enzyme Inhibitors Administration Prior to Acute Ischemic Stroke Onset on In-Hospital Mortality

Introduction: Angiotensin-converting enzyme inhibitors (ACEIs) have shown promising results in decreasing the incidence and the severity of ischemic stroke in populations at risk and in improving ischemic stroke outcomes. Objectives: The objectives of this study were to investigate the impact of ACEI use before ischemic stroke onset on in-hospital mortality and to identify the independent predictors of in-hospital mortality among patients with ischemic stroke. Methods and Materials: A retrospective cohort study of all patients with acute ischemic stroke attending the hospital from June 1, 2008 to November 30, 2008 was performed. Data were collected from medical records and included demographic information, diagnostic information, risk factors, previous ACEI use, and vital discharge status. Statistical Package for Social Sciences (SPSS) version 15 was used for data analysis. Results: A total of 327 patients with acute ischemic stroke were studied, of which 119 (36.4%) had documented previous ACEI use. During the study period, 52 (15.9%) of the patients with acute ischemic stroke died in hospital. In-hospital mortality was significantly lower among patients who were on ACEI before the attack (P = 0.002). The independent predictors for in-hospital mortality among patients with ischemic stroke were age ≥65 years (P < .001), the presence of diabetes mellitus (P = .012), renal impairment (P = .002), and heart failure (P = .001). Moreover, prior use of ACEI was an independent predictor for survival after ischemic stroke attack (P < .001). Conclusion: This study provides evidence that the prophylactic administration of ACEI before ischemic stroke may be a potential life-saving strategy. Furthermore, knowledge of in-hospital mortality predictors is necessary to improve survival rate after acute stroke.
Failure of the Adipocytokine, Resistin, to Protect the Heart From Ischemia-Reperfusion Injury

Experimental studies have linked the adipocytokines with acute cardioprotection. Whether the adipocytokine, resistin, confers protection is, however, debatable. In the current study, the actions of resistin, administered at reperfusion, were investigated in in vivo and in vitro rodent and in vitro human models of myocardial ischemia-reperfusion (I/R) injury. Resistin did not reduce infarct size in Langendorff-perfused rat hearts or murine hearts perfused in vivo. Resistin also did not protect human atrial muscle subjected to hypoxia-reoxygenation. Although cyclosporin A delayed mitochondrial permeability transition pore (MPTP) opening in murine cardiomyocytes, resistin was ineffective. Western blot analysis revealed that resistin treatment was associated with enhanced phosphorylation of Akt, at both the serine-473 (+ 51.9%, P = .01) and threonine-308 (+107%, P < .01) phosphorylation sites, although not to the extent seen with ischemic preconditioning (+132.5%, P = .002 and +389.1%, P < .01, respectively). We conclude that resistin administered at reperfusion at concentrations/doses equivalent to normal (upper end) and pathological serum levels does not protect against I/R injury or inhibit MPTP opening.
Enhanced water permeability and tunable ion selectivity in subnanometer carbon nanotube porins

Go with the flow Enhanced water transport occurs in a number of narrow pore channels, such as biological aquaporins. Tunuguntla et al. thoroughly characterized molecular transport through narrow carbon nanotubes (CNTs) (see the Perspective by Siwy and Fornasiero). In contrast to previous studies, the authors focused on water and ion transport through relatively short (∼10-nm) fragments of CNTs embedded in lipid bilayer membranes. Strong confinement generated highly accelerated water flow compared with that observed in biological water transporters. A key factor in the transport rate was the tunable rearrangement of intermolecular hydrogen bonding. Furthermore, by changing the charges at the mouth of the nanotube, the authors were able to alter the ion selectivity. Science, this issue p. 792; see also p. 753 Small-diameter carbon nanotubes show promising transport properties and selectivity for water purification applications. Fast water transport through carbon nanotube pores has raised the possibility to use them in the next generation of water treatment technologies. We report that water permeability in 0.8-nanometer-diameter carbon nanotube porins (CNTPs), which confine water down to a single-file chain, exceeds that of biological water transporters and of wider CNT pores by an order of magnitude. Intermolecular hydrogen-bond rearrangement, required for entry into the nanotube, dominates the energy barrier and can be manipulated to enhance water transport rates. CNTPs block anion transport, even at salinities that exceed seawater levels, and their ion selectivity can be tuned to configure them into switchable ionic diodes. These properties make CNTPs a promising material for developing membrane separation technologies.
Curcumin Protects Against Regional Myocardial Ischemia/Reperfusion Injury Through Activation of RISK/GSK-3β and Inhibition of p38 MAPK and JNK

Background: Curcumin, the active ingredient of turmeric (Curcuma longa), is known to have anti-inflammatory and antioxidative properties. The present study was aimed to determine the effect of curcumin in regional myocardial ischemia/reperfusion (I/R) injury and its underlying mechanisms involving the role of prosurvival kinases and apoptotic kinases. Methods: Sprague-Dawley rats (n = 109) subjected to a 30-minute left anterior descending coronary artery (LAD) occlusion followed by reperfusion were assigned to receive saline (control), curcumin (100 mg/kg), wortmannin (inhibitor of phosphatidylinositol-3-OH kinase [PI3K]-Akt), wortmannin + curcumin, U0126 (inhibitor of extracellular signal-regulated kinase [ERK1/2]), U0126 + curcumin, SB216763 (inhibitor of glycogen synthase kinase [GSK-3β]), and SB216763 + curcumin 20 minutes before LAD occlusion. Infarct size was measured after 2 hours of reperfusion by triphenyl tetrazolium chloride staining. The phosphorylation of Akt, ERK1/2, GSK-3β, p38, and c-Jun N-terminal kinases (JNK) was determined by immunoblotting after 10 minutes of reperfusion. Results: Curcumin significantly reduced the infarct size compared with the control (33.1% ± 6.2% vs 50.1% ± 3.9%; P < .05). Wortmannin or U0126 alone did not affect the infarct size but abolished the curcumin-induced cardioprotective effect. Curcumin significantly enhanced the phosphorylation of Akt, ERK1/2, and GSK-3β, while it reduced that of p38 and JNK. Wortmannin or U0126 abolished enhanced phosphorylation of GSK-3β induced by curcumin. SB216763 alone or combined with curcumin reduced the infarct size and enhanced phosphorylation of GSK-3β compared with the control. Conclusions: Preconditioning by curcumin effectively protects against regional myocardial I/R injury through the activation of prosurvival kinases involving PI3K-Akt, ERK1/2, and GSK-3β, and attenuation of p38 and JNK.
Monitoring and manipulating Higgs and Goldstone modes in a supersolid quantum gas

Breaking the symmetry in a supersolid The concept of broken symmetry has relevance across all branches of physics, including particle and condensed matter physics. In many cases, the shape of the potential energy resembles a Mexican hat, and the symmetry of the system is broken when it chooses a particular spot along the “trough” of the hat. Out of this minimum-energy state, the system can undergo collective excitations either along the trough or perpendicular to it. Léonard et al. detected these so-called Goldstone and Higgs modes in a supersolid Bose-condensed atomic gas held in two crossed optical cavities. By monitoring the dynamics of the light field in each cavity, the oscillations of the order parameter associated with both modes were observed in real time. Science, this issue p. 1415 Oscillations associated with collective modes in a broken symmetry state are measured in real time. Higgs and Goldstone modes are collective excitations of the amplitude and phase of an order parameter that is related to the breaking of a continuous symmetry. We directly studied these modes in a supersolid quantum gas created by coupling a Bose-Einstein condensate to two optical cavities, whose field amplitudes form the real and imaginary parts of a U(1)-symmetric order parameter. Monitoring the cavity fields in real time allowed us to observe the dynamics of the associated Higgs and Goldstone modes and revealed their amplitude and phase nature. We used a spectroscopic method to measure their frequencies, and we gave a tunable mass to the Goldstone mode by exploring the crossover between continuous and discrete symmetry. Our experiments link spectroscopic measurements to the theoretical concept of Higgs and Goldstone modes.
Desensitization of myocardial β‐adrenergic receptors in cirrhotic rats

Cardiac responses to catecholamines are known to be attenuated in chronic liver disease. To elucidate the role of β‐adrenergic receptor alteration in this phenomenon, we measured heart rate responsiveness to isoprenaline and myocardial β‐adrenergic receptor–binding characteristics in three groups of rats: those that were sham operated, those that had portal vein stenosis and those that were cirrhotic because of bile duct ligation. Responsiveness to isoprenaline was evaluated in conscious rats by the dose of isoprenaline needed to increase basal heart rate by 50 beats/min and by the maximal heart rate response. β‐Receptor characteristics in heart membranes were derived from 125I‐iodocyanopindolol binding data. Compared with sham‐operated controls, cirrhotic rats needed a significantly higher dose of isoprenaline to raise basal heart rate by (50 beats/min). (102.3 ± 19.1 vs. 28.3 ± 11.3 ng/kg) and lower maximal heart rate response (104 ± 29 vs. 158 ± 61 beats/min). In addition, myocardial β‐receptor density was significantly lower in cirrhotic rats (26.5 ± 4.6 vs. 37.5 ± 10.3 fmol/mg protein) and the dissociation constant was higher (31.6 ± 17.0 vs. 14.0 ± 2.5 pmol/L). Analysis of β1/β2 subpopulations revealed that the decreased total β‐receptor density was entirely due to selective β1‐receptor down‐regulation. β‐Receptor affinity for agonist was not altered in cirrhotic rats. Rats with portal vein stenosis showed no significant differences in either isoprenaline responsiveness or β‐receptor characteristics when compared with controls. These results indicate that β‐adrenergic receptor down‐regulation may be responsible for the myocardial hyporesponsiveness to catecholamines observed in cirrhosis. (HEPATOLOGY 1990;12:481–485).
Long-term pattern and magnitude of soil carbon feedback to the climate system in a warming world

Climate and the carbon cycle It is still not clear how global warming will affect the global carbon cycle, either in terms of the magnitude of the effect or even its sign. Help in answering that question will come from long-term field-based experiments designed to explore carbon cycle-climate feedbacks in an ecosystem context. Melillo et al. performed a 26-year soil-warming experiment in a mid-latitude hardwood forest (see the Perspective by Metcalfe). Warming has resulted in a complex pattern of net carbon loss from the soil. These results support projections of a long-term, positive carbon feedback from similar ecosystems as the world warms. Science, this issue p. 101; See also p. 41 Mid-latitude hardwood forests will be a carbon source as climate warms. In a 26-year soil warming experiment in a mid-latitude hardwood forest, we documented changes in soil carbon cycling to investigate the potential consequences for the climate system. We found that soil warming results in a four-phase pattern of soil organic matter decay and carbon dioxide fluxes to the atmosphere, with phases of substantial soil carbon loss alternating with phases of no detectable loss. Several factors combine to affect the timing, magnitude, and thermal acclimation of soil carbon loss. These include depletion of microbially accessible carbon pools, reductions in microbial biomass, a shift in microbial carbon use efficiency, and changes in microbial community composition. Our results support projections of a long-term, self-reinforcing carbon feedback from mid-latitude forests to the climate system as the world warms.