Global Gene Expression Analysis of the Reversed Gravitropic Response of the lazy-2 Mutation in Tomato (Solanum lycopersicum)

The lazy-2 mutation (lz-2) in tomato plants (Solanum lycopersicum) is exhibited as a phenotype of light-dependent reversed-gravitropism. The mutation’s centromeric location has only allowed for speculation on the identity of the lz-2 gene. In order to investigate the relationship and affect of thelz-2 mutation on signaling pathways linked to auxin growth hormone regulation, global gene activity was assessed. Modern molecular biology tools including microarray technology and various PCR techniques were utilized to generate a list of significantly differentially regulated genes in lz-2 mutant plants compared to wild-type plants. Gene ontology functional analysis indicated that genes involved in protein ubiquitination constituted the largest percentage of differentially expressed genes, while signal transduction genes were also a significant fraction of all genes studied. Top gene candidates were tested by qPCR to verify statistically significant up- or down-regulation in lz-2 mutant plants. Two such candidates, a gene encoding an f-box family protein and the ATCUL1 gene encoding a cullin protein have been implicated as major components of the SCF ubiquitin-ligase complex, which degrades auxin repressor proteins. This study suggests a potential relationship between differential expression of ubiquitin-ligase proteins causing altered auxin signaling and the downward growth of lz-2 mutant tomato plants in response to gravity

Lessons Learned from the Implementation of a Medically Enhanced Residential Treatment (Mert) Model Integrating Intravenous Antibiotics and Residential Addiction Treatment

BACKGROUND: Hospitalizations for severe infections associated with substance use disorder (SUD) are increasing. People with SUD often remain hospitalized for many weeks instead of completing intravenous antibiotics at home; often, they are denied skilled nursing facility admission. Residential SUD treatment facilities are not equipped to administer intravenous antibiotics. We developed a medically enhanced residential treatment (MERT) model integrating residential SUD treatment and long-term IV antibiotics as part of a broader hospital-based addiction medicine service. MERT had low recruitment and retention, and ended after six months. The goal of this study was to describe the feasibility and acceptability of MERT, to understand implementation factors, and explore lessons learned. METHODS: We conducted a mixed-methods evaluation. We included all potentially eligible MERT patients, defined by those needing ≥2 weeks of intravenous antibiotics discharged from February 1 to August 1, 2016. We used chart review to identify diagnoses, antibiotic treatment location, and number of recommended and actual IV antibiotic-days completed. We audiorecorded and transcribed key informant interviews with patients and staff. We conducted an ethnographic analysis of interview transcripts and implementation field notes. RESULTS: Of the 45 patients needing long-term intravenous antibiotics, 18 were ineligible and 20 declined MERT. 7 enrolled in MERT and three completed their recommended intravenous antibiotic course. MERT recruitment barriers included patient ambivalence towards residential treatment, wanting to prioritize physical health needs, and fears of untreated pain in residential. MERT retention barriers included high demands of residential treatment, restrictive practices due to PICC lines, and perceptions by staff and other residents that MERT patients “stood out” as “different.” Despite the challenges, key informants felt MERT was a positive construct. CONCLUSIONS: Though MERT had many possible advantages; it proved more challenging to implement than anticipated. Our lessons may be applicable to future models integrating posthospital intravenous antibiotics and SUD care

Reaction of the C2H radical with 1-Butyne (C4H6): Low Temperature Kinetics and Isomer-Specific Product Detection

The rate coefficient for the reaction of the ethynyl radical (C{sub 2}H) with 1-butyne (H-C{triple_bond}C-CH{sub 2}-CH{sub 3}) is measured in a pulsed Laval nozzle apparatus. Ethynyl radicals are formed by laser photolysis of acetylene (C{sub 2}H{sub 2}) at 193 nm and detected via chemiluminescence (C{sub 2}H + O{sub 2} {yields} CH (A{sup 2}{Delta}) + CO{sub 2}). The rate coefficients are measured over the temperature range of 74-295 K. The C{sub 2}H + 1-butyne reaction exhibits no barrier and occurs with rate constants close to the collision limit. The temperature dependent rate coefficients can be fit within experimental uncertainties by the expression k = (2.4 {+-} 0.5) x 10{sup -10} (T/295 K)-(0.04 {+-} 0.03) cm{sup 3} molecule{sup -1}s{sup -1}. Reaction products are detected at room temperature (295 K) and 533 Pa using a Multiplexed Photoionization Mass Spectrometer (MPIMS) coupled to the tunable VUV synchrotron radiation from the Advanced Light Source at the Lawrence Berkeley National Laboratory. Two product channels are identified for this reaction: m/z = 64 (C{sub 5}H{sub 4}) and m/z = 78 (C{sub 6}H{sub 6}) corresponding to the CH{sub 3}- and H-loss channels, respectively. Photoionization efficiency (PIE) curves are used to analyze the isomeric composition of both product channels. The C{sub 5}H{sub 4} products are found to be exclusively linear isomers composed of ethynylallene and methyldiacetylene in a 4:1 ratio. In contrast, the C{sub 6}H{sub 6} product channel includes two cyclic isomers, fulvene 18({+-}5)% and 3,4-dimethylenecyclobut-1-ene 32({+-}8)%, as well as three linear isomers, 2-ethynyl-1,3-butadiene 8({+-}5)%, 3,4-hexadiene-1-yne 28({+-}8)% and 1,3-hexadiyne 14({+-}5)%. Within experimental uncertainties, we do not see appreciable amounts of benzene and an upper limit of 10% is estimated. Diacetylene (C{sub 4}H{sub 2}) formation via the C{sub 2}H{sub 5}-loss channel is also thermodynamically possible but cannot be observed due to experimental limitations. The implications of these results for modeling of planetary atmospheres, especially of Saturn's largest moon Titan, are discussed

Annales des sciences forestières

The reaction of the ground state methylidyne radical CH (X2Pi) with pyrrole (C4H5N) has been studied in a slow flow tube reactor using Multiplexed Photoionization Mass Spectrometry coupled to quasi-continuous tunable VUV synchrotron radiation at room temperature (295 K) and 90 oC (363 K), at 4 Torr (533 Pa). Laser photolysis of bromoform (CHBr3) at 248 nm (KrF excimer laser) is used to produce CH radicals that are free to react with pyrrole molecules in the gaseous mixture. A signal at m/z = 79 (C5H5N) is identified as the product of the reaction and resolved from 79Br atoms, and the result is consistent with CH addition to pyrrole followed by Helimination. The Photoionization Efficiency curve unambiguously identifies m/z = 79 as pyridine. With deuterated methylidyne radicals (CD), the product mass peak is shifted by +1 mass unit, consistent with the formation of C5H4DN and identified as deuterated pyridine (dpyridine). Within detection limits, there is no evidence that the addition intermediate complex undergoes hydrogen scrambling. The results are consistent with a reaction mechanism that proceeds via the direct CH (CD) cycloaddition or insertion into the five-member pyrrole ring, giving rise to ring expansion, followed by H atom elimination from the nitrogen atom in the intermediate to form the resonance stabilized pyridine (d-pyridine) molecule. Implications to interstellar chemistry and planetary atmospheres, in particular Titan, as well as in gas-phase combustion processes, are discussed

Reaction of the C2H radical with 1-butyne (C4H6): Low Temperature Kinetics and Isomer-Specific Product Detection

The rate coefficient for the reaction of the ethynyl radical (C{sub 2}H) with 1-butyne (H-C{triple_bond}C-CH{sub 2}-CH{sub 3}) is measured in a pulsed Laval nozzle apparatus. Ethynyl radicals are formed by laser photolysis of acetylene (C{sub 2}H{sub 2}) at 193 nm and detected via chemiluminescence (C{sub 2}H + O{sub 2} {yields} CH (A{sup 2}{Delta}) + CO{sub 2}). The rate coefficients are measured over the temperature range of 74-295 K. The C{sub 2}H + 1-butyne reaction exhibits no barrier and occurs with rate constants close to the collision limit. The temperature dependent rate coefficients can be fit within experimental uncertainties by the expression k = (2.4 {+-} 0.5) x 10{sup -10} (T/295 K)-(0.04 {+-} 0.03) cm{sup 3} molecule{sup -1}s{sup -1}. Reaction products are detected at room temperature (295 K) and 533 Pa using a Multiplexed Photoionization Mass Spectrometer (MPIMS) coupled to the tunable VUV synchrotron radiation from the Advanced Light Source at the Lawrence Berkeley National Laboratory. Two product channels are identified for this reaction: m/z = 64 (C{sub 5}H{sub 4}) and m/z = 78 (C{sub 6}H{sub 6}) corresponding to the CH{sub 3}- and H-loss channels, respectively. Photoionization efficiency (PIE) curves are used to analyze the isomeric composition of both product channels. The C{sub 5}H{sub 4} products are found to be exclusively linear isomers composed of ethynylallene and methyldiacetylene in a 4:1 ratio. In contrast, the C{sub 6}H{sub 6} product channel includes two cyclic isomers, fulvene 18({+-}5)% and 3,4-dimethylenecyclobut-1-ene 32({+-}8)%, as well as three linear isomers, 2-ethynyl-1,3-butadiene 8({+-}5)%, 3,4-hexadiene-1-yne 28({+-}8)% and 1,3-hexadiyne 14({+-}5)%. Within experimental uncertainties, we do not see appreciable amounts of benzene and an upper limit of 10% is estimated. Diacetylene (C{sub 4}H{sub 2}) formation via the C{sub 2}H{sub 5}-loss channel is also thermodynamically possible but cannot be observed due to experimental limitations. The implications of these results for modeling of planetary atmospheres, especially of Saturn's largest moon Titan, are discussed

Thyroid Progenitors Are Robustly Derived from Embryonic Stem Cells through Transient, Developmental Stage-Specific Overexpression of Nkx2-1

Summary The clinical importance of anterior foregut endoderm (AFE) derivatives, such as thyrocytes, has led to intense research efforts for their derivation through directed differentiation of pluripotent stem cells (PSCs). Here, we identify transient overexpression of the transcription factor (TF) NKX2-1 as a powerful inductive signal for the robust derivation of thyrocyte-like cells from mouse PSC-derived AFE. This effect is highly developmental stage specific and dependent on FOXA2 expression levels and precise modulation of BMP and FGF signaling. The majority of the resulting cells express thyroid TFs (Nkx2-1, Pax8, Foxe1, Hhex) and thyroid hormone synthesis-related genes (Tg, Tpo, Nis, Iyd) at levels similar to adult mouse thyroid and give rise to functional follicle-like epithelial structures in Matrigel culture. Our findings demonstrate that NKX2-1 overexpression converts AFE to thyroid epithelium in a developmental time-sensitive manner and suggest a general methodology for manipulation of cell-fate decisions of developmental intermediates