Modelling and Thermographic Measurements of LED Optical Power.

This paper presents a simple engineering method for evaluating the optical power emitted by light-emitting diodes (LEDs) using infrared thermography. The method is based on the simultaneous measurement of the electrical power and temperature of an LED and a heat source (resistor) that are enclosed in the same plastic packaging under the same cooling conditions. This ensures the calculation of the optical power emitted by the LED regardless of the value of the heat transfer coefficient.

Respiration is essential for aerobic growth of ZM4.

A key to producing next-generation biofuels is to engineer microbes that efficiently convert non-food materials into drop-in fuels, and to engineer microbes effectively, we must understand their metabolism thoroughly. is a bacterium that is a promising candidate biofuel producer, but its metabolism remains poorly understood, especially its metabolism when exposed to oxygen. Although respires with oxygen, its aerobic growth is poor, and disruption of genes related to respiration counterintuitively improves aerobic growth.

The genetics of aerotolerant growth in an alphaproteobacterium with a naturally reduced genome.

The inherent complexity of biological systems is a major barrier to our understanding of cellular physiology. Bacteria with markedly fewer genes than their close relatives, or reduced genome bacteria, are promising biological models with less complexity. Reduced genome bacteria can also have superior properties for industrial use, provided the reduction does not overly restrict strain robustness.

Zymomonas mobilis ZM4 Utilizes an NADP-Dependent Acetaldehyde Dehydrogenase To Produce Acetate.

Zymomonas mobilis is a promising bacterial host for biofuel production, but further improvement has been hindered because some aspects of its metabolism remain poorly understood. For example, one of the main by-products generated by Z. mobilis is acetate, but the pathway for acetate production is unknown.

Zymomonas diversity and potential for biofuel production.

Background: Zymomonas mobilis is an aerotolerant α-proteobacterium, which has been genetically engineered for industrial purposes for decades. However, a comprehensive comparison of existing strains on the genomic level in conjunction with phenotype analysis has yet to be carried out. We here performed whole-genome comparison of 17 strains including nine that were sequenced in this study.

Expression of Phosphofructokinase Is Not Sufficient to Enable Embden-Meyerhof-Parnas Glycolysis in ZM4.

is a bacterium that produces ethanol from glucose at up to 97% of theoretical efficiency on a carbon basis. One factor contributing to the high efficiency of ethanol production is that has a low biomass yield. The low biomass yield may be caused partly by the low ATP yield of the Entner-Doudoroff (ED) glycolytic pathway used by , which produces only one ATP per glucose consumed.

Traditional matriculation vs an early assurance program: Effect on elected student leadership positions and academic performance.

Introduction: The objective of this study was to compare leadership and academic performance among students admitted by traditional pathways vs. a dual acceptance program (DAP).

Methods: A list of students admitted to the Midwestern University Chicago College of Pharmacy (MWUCCP) DAP was cross-checked with students elected to serve in leadership positions and students on the MWUCCP Dean's List for their first professional year from 2010 to 2015.

DnaC, the indispensable companion of DnaB helicase, controls the accessibility of DnaB helicase by primase.

Former studies relying on hydrogen/deuterium exchange analysis suggest that DnaC bound to DnaB alters the conformation of the N-terminal domain (NTD) of DnaB to impair the ability of this DNA helicase to interact with primase. Supporting this idea, the work described herein based on biosensor experiments and enzyme-linked immunosorbent assays shows that the DnaB-DnaC complex binds poorly to primase in comparison with DnaB alone. Using a structural model of DnaB complexed with the C-terminal domain of primase, we found that Ile-85 is located at the interface in the NTD of DnaB that contacts primase.

Transition of stable patients from traditional anticoagulation clinic services to telephonic management.

Background Outpatient warfarin dosing and monitoring with telephonic anticoagulation management (TAM) could be an effective alternative to other more labor intensive management models. Objectives To evaluate the time in therapeutic range (TTR) and number of extreme INR values (<1.5 or >4.

Substitutions of Conserved Residues in the C-terminal Region of DnaC Cause Thermolability in Helicase Loading.

The DnaB-DnaC complex binds to the unwound DNA within the Escherichia coli replication origin in the helicase loading process, but the biochemical events that lead to its stable binding are uncertain. This study characterizes the function of specific C-terminal residues of DnaC. Genetic and biochemical characterization of proteins bearing F231S and W233L substitutions of DnaC reveals that their activity is thermolabile.

Mutant DnaAs of Escherichia coli that are refractory to negative control.

DnaA is the initiator of DNA replication in bacteria. A mutant DnaA named DnaAcos is unusual because it is refractory to negative regulation. We developed a genetic method to isolate other mutant DnaAs that circumvent regulation to extend our understanding of mechanisms that control replication initiation.

The rcbA gene product reduces spontaneous and induced chromosome breaks in Escherichia coli.

Elevated levels of DnaA cause excessive initiation, which leads to an increased level of double-strand breaks that are proposed to arise when newly formed replication forks collide from behind with stalled or collapsed forks. These double-strand breaks are toxic in mutants that are unable to repair them. Using a multicopy suppressor assay to identify genes that suppress this toxicity, we isolated a plasmid carrying a gene whose function had been unknown.

Two forms of ribosomal protein L2 of Escherichia coli that inhibit DnaA in DNA replication.

We purified an inhibitor of oriC plasmid replication and determined that it is a truncated form of ribosomal protein L2 evidently lacking 59 amino acid residues from the C-terminal region encoded by rplB. We show that this truncated form of L2 or mature L2 physically interacts with the N-terminal region of DnaA to inhibit initiation from oriC by apparently interfering with DnaA oligomer formation, and the subsequent assembly of the prepriming complex on an oriC plasmid. Both forms of L2 also inhibit the unwinding of oriC by DnaA.

Prevalent aetiologies of non-therapeutic warfarin anticoagulation in a network of pharmacist-managed anticoagulation clinics.

What Is Known And Objective: There is wide inter-patient and intra-patient variability in the pharmacodynamic profile of warfarin. To determine the prevailing aetiologies of non-therapeutic warfarin anticoagulation episodes among patients currently enrolled in an outpatient anticoagulation clinic and compare the relative frequency in which they occur compared to therapeutic anticoagulation regimens.

Methods: Prospective, observational cohort study set within three pharmacist-managed anticoagulation clinics in a community outpatient health system.

DnaAcos hyperinitiates by circumventing regulatory pathways that control the frequency of initiation in Escherichia coli.

Mutants of dnaAcos are inviable at 30 degrees C because DnaAcos hyperinitiates, leading to new replication forks that apparently collide from behind with stalled forks, thereby generating lethal double-strand breaks. By comparison, an elevated level of DnaA also induces extra initiations, but lethality occurs only in strains defective in repairing double-strand breaks. To explore the model that the chromosomal level of DnaAcos, or the increased abundance of DnaA, increases initiation frequency by, escaping or overcoming pathways that control initiation, respectively, we developed a genetic selection and identified seqA, datA, dnaN and hda, which function in pathways that either act at oriC or modulate DnaA activity.

A new case of DOOR syndrome.

We present the case of a 9-year-old boy with DOOR syndrome recognized in the first year of his life because of a delayed development of speech. The diagnosis was based on characteristic abnormalities, including congenital deafness, nail and bone abnormalities, and mild mental retardation.

Escherichia coli DnaA interacts with HU in initiation at the E. coli replication origin.

Escherichia coli HU protein is a dimer encoded by two closely related genes whose expression is growth phase-dependent. As a major component of the bacterial nucleoid, HU binds to DNA non-specifically, but acts at the chromosomal origin (oriC) during initiation by stimulating strand opening in vitro. We show that the alpha dimer of HU is more active than other forms of HU in initiation of an oriC-containing plasmid because it more effectively promotes strand opening of oriC.

An essential tryptophan of Escherichia coli DnaA protein functions in oligomerization at the E. coli replication origin.

In the initiation of bacterial DNA replication, DnaA protein recruits DnaB helicase to the chromosomal origin, oriC, leading to the assemble of the replication fork machinery at this site. Because a region near the N terminus of DnaA is required for self-oligomerization and the loading of DnaB helicase at oriC, we asked if these functions are separable or interdependent by substituting many conserved amino acids in this region with alanine to identify essential residues. We show that alanine substitutions of leucine 3, phenylalanine 46, and leucine 62 do not affect DnaA function in initiation.

The box VII motif of Escherichia coli DnaA protein is required for DnaA oligomerization at the E. coli replication origin.

Escherichia coli DnaA protein initiates DNA replication from the chromosomal origin, oriC, and regulates the frequency of this process. Structure-function studies indicate that the replication initiator comprises four domains. Based on the structural similarity of Aquifex aeolicus DnaA to other AAA+ proteins that are oligomeric, it was proposed that Domain III functions in oligomerization at oriC (Erzberger, J.

UV- and MMS-induced mutagenesis of lambdaO(am)8 phage under nonpermissive conditions for phage DNA replication.

Mutagenesis in Escherichia coli, a subject of many years of study is considered to be related to DNA replication. DNA lesions nonrepaired by the error-free nucleotide excision repair (NER), base excision repair (BER) and recombination repair (RR), stop replication at the fork. Reinitiation needs translesion synthesis (TLS) by DNA polymerase V (UmuC), which in the presence of accessory proteins, UmuD', RecA and ssDNA-binding protein (SSB), has an ability to bypass the lesion with high mutagenicity.

DnaA Protein of Escherichia coli: oligomerization at the E. coli chromosomal origin is required for initiation and involves specific N-terminal amino acids.

Iterated DnaA box sequences within the replication origins of bacteria and prokaryotic plasmids are recognized by the replication initiator, DnaA protein. At the E. coli chromosomal origin, oriC, DnaA is speculated to oligomerize to initiate DNA replication.

The isfA mutation specifically inhibits the SOS-dependent mutagenic pathway and does not selectively affect any particular base substitution.

We have previously described a new mutation in Escherichia coli, isfA, which causes inhibition of SOS mutagenesis (UV-induced in rec+ and spontaneous in recA730 strains) and several SOS-dependent phenomena. Antimutagenic activity of the isfA mutation in the recA730 strain was shown to be related to inhibition of processing of UmuD to UmuD' by RecA* coprotease. In the present study we have analysed the specificity of the antimutagenic activity of the isfA mutation by employing F' plasmids carrying a set of mutant lacZ genes that can individually detect two types of transitions and four types of transversions.