ABSTRACT
The shoots of cultivated tomato (Lycopersicon esculentum cv. T5) wilt if their roots are exposed to chilling temperatures of around 5 °C. Under the same treatment, a chilling‐tolerant ...congener (Lycopersicon hirsutum LA 1778) maintains shoot turgor. To determine the physiological basis of this differential response, the effect of chilling on both excised roots and roots of intact plants in pressure chambers were investigated. In excised roots and intact plants, root hydraulic conductance declined with temperature to nearly twice the extent expected from the temperature dependence of the viscosity of water, but the response was similar in both species. The species differed markedly, however, in stomatal behaviour: in L. hirsutum, stomatal conductance declined as root temperatures were lowered, whereas the stomata of L. esculentum remained open until the roots reached 5 °C, and the plants became flaccid and suffered damage. Grafted plants with the shoots of one genotype and roots of another indicated that the differential stomatal behaviour during root chilling has distinct shoot and root components.
The safety of selective cyclooxygenase-2 inhibitors in patients with ulcerative colitis in remission is unknown.
We performed a placebo-controlled pilot trial to evaluate the safety of celecoxib in ...patients with ulcerative colitis in remission who had a present or past history of nonspecific arthritis, arthralgia, or other condition amenable to nonsteroidal anti-inflammatory drug therapy. A total of 222 patients with ulcerative colitis in remission were randomized to receive oral celecoxib 200 mg or placebo twice daily for 14 days. Remission was defined as a total Mayo Clinic score of 2 points or less and an endoscopic score of 1 point or less. Disease exacerbation was defined as a total Mayo Clinic score of 5 points or more and an increase in the endoscopic score of 1 point or more. The primary analysis was disease exacerbation through day 14 among patients who underwent randomization, had at least 1 dose of study drug, and had both endoscopy and Mayo Clinic disease activity index scores at the baseline and final assessments.
Three percent of patients in the celecoxib group experienced disease exacerbation through day 14, as compared with 4% in the placebo group (P = .719). Eleven percent of patients in each group experienced a bowel-related adverse event (P > .20).
Therapy with celecoxib for up to 14 days did not have a greater relapse rate than placebo in patients with ulcerative colitis in remission who had a present or past history of nonspecific arthritis, arthralgia, or other condition amenable to nonsteroidal anti-inflammatory drug therapy.
We present the Fermi Large Area Telescope (LAT) observations of the binary neutron star merger event GW170817 and the associated short gamma-ray burst (SGRB) GRB 170817A detected by the Fermi ...Gamma-ray Burst Monitor. The LAT was entering the South Atlantic Anomaly at the time of the LIGO/Virgo trigger (tGW) and therefore cannot place constraints on the existence of high-energy (E > 100 MeV) emission associated with the moment of binary coalescence. We focus instead on constraining high-energy emission on longer timescales. No candidate electromagnetic counterpart was detected by the LAT on timescales of minutes, hours, or days after the LIGO/Virgo detection. The resulting flux upper bound (at 95% C.L.) from the LAT is 4.5 × 10−10 erg cm−2 s−1 in the 0.1-1 GeV range covering a period from tGW + 1153 s to tGW + 2027 s. At the distance of GRB 170817A, this flux upper bound corresponds to a luminosity upper bound of 9.7 × 1043 erg s−1, which is five orders of magnitude less luminous than the only other LAT SGRB with known redshift, GRB 090510. We also discuss the prospects for LAT detection of electromagnetic counterparts to future gravitational-wave events from Advanced LIGO/Virgo in the context of GW170817/GRB 170817A.
A polymerase chain reaction (PCR) assay that detects Borrelia burgdorferi DNA in cerebrospinal fluid (CSF) was evaluated as a diagnostic test for acute or chronic Lyme neuroborreliosis. In one ...laboratory, 102 samples were tested blindly, and 40 samples were retested in a second laboratory. In the first laboratory, B. burgdorferi DNA was detected in CSF samples in 6 (38%) of 16 patients with acute neuroborreliosis, 11 (25%) of 44 with chronic neuroborreliosis, and none of 42 samples from patients with other illnesses. There was a significant correlation between PCR results and the duration of previous intravenous antibiotic therapy. The overall frequency of positive results was similar in the second laboratory, but concordance between the laboratories and among primer-probe sets was limited because many samples were positive with only one primer-probe set. Thus, PCR testing can sometimes detect B. burgdorferi DNA in CSF in patients with acute or chronic neuroborreliosis, but with current methods, the sensitivity of the test is limited.
We present the fourth Fermi Large Area Telescope catalog (4FGL) of γ-ray sources. Based on the first eight years of science data from the Fermi Gamma-ray Space Telescope mission in the energy range ...from 50 MeV to 1 TeV, it is the deepest yet in this energy range. Relative to the 3FGL catalog, the 4FGL catalog has twice as much exposure as well as a number of analysis improvements, including an updated model for the Galactic diffuse γ-ray emission, and two sets of light curves (one-year and two-month intervals). The 4FGL catalog includes 5064 sources above 4 significance, for which we provide localization and spectral properties. Seventy-five sources are modeled explicitly as spatially extended, and overall, 358 sources are considered as identified based on angular extent, periodicity, or correlated variability observed at other wavelengths. For 1336 sources, we have not found plausible counterparts at other wavelengths. More than 3130 of the identified or associated sources are active galaxies of the blazar class, and 239 are pulsars.
The inducible costimulatory molecule (ICOS) is expressed on activated T cells and participates in a variety of important immunoregulatory functions. After the induction of experimental allergic ...encephalomyelitis in SJL mice with proteolipid protein (PLP), brain ICOS mRNA and protein were up-regulated on infiltrating CD3+ T cells before disease onset. ICOS blockade during the efferent immune response (9-20 days after immunization) abrogated disease, but blockade during antigen priming (1-10 days after immunization) exacerbated disease. Upon culture with PLP and compared with immunized controls, splenocytes produced either decreased interferon-gamma (IFN-gamma, in efferent blockade) or excessive IFN-gamma (in priming blockade). PLP-specific immunoglobulin G1 was decreased in animals treated with anti-ICOS during antigen priming, but not in other groups.
Energetic young pulsars and expanding blast waves supernova remnants (SNRs) are the most visible remains after massive stars, ending their lives, explode in core-collapse supernovae. The Fermi ...Gamma-Ray Space Telescope has unveiled a radio quiet pulsar located near the center of the compact synchrotron nebula inside the supernova remnant CTA 1. The pulsar, discovered through its gamma-ray pulsations, has a period of 316.86 milliseconds and a period derivative of 3.614 x 10⁻¹³ seconds per second. Its characteristic age of 10⁴ years is comparable to that estimated for the SNR. We speculate that most unidentified Galactic gamma-ray sources associated with star-forming regions and SNRs are such young pulsars.
Atlantic salmon Salmo salar smolts (n = 181) from two rivers were surgically implanted with acoustic transmitters and released to determine migration route, residency time and survival in a 50 km ...long estuarine fjord located on the south coast of Newfoundland, Canada. Data obtained from automated receivers placed throughout the Bay d’Espoir fjord indicated that migrating smolts used different routes to reach the outer areas of the fjord. The duration of time that smolts spent in the immediate estuary zone also differed between the two localities (7 and 17 days) although the total time smolts were resident in the fjord was similar and extensive (40 days). Many smolts were resident for periods of 4–8 weeks moving back and forth in the outer part of the fjord where maximum water depths range from 300 to 700 m. Survival in the estuary zone was greater for smolts with prolonged residency in estuarine habitat. Overall smolt survival to the fjord exit was moderately high (54–85%), indicating that the initial phase of migration did not coincide with a period of unusually high mortality.
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