A multisession, undergraduate molecular biology lab experiment using Green Fluorescent Protein including subcloning and color changing mutagenesis.

This paper describes a series of experiments involving handling and manipulating the DNA coding for Green Fluorescent Protein (GFP) including the subcloning of this gene, and mutating the DNA so that Cyan Fluorescent Protein (CFP) or Blue Fluorescent protein (BFP) are expressed. The primers needed for the PCR based subcloning of GFP are presented, as are those needed to mutate the GFP to either CFP or BFP

The Identification of Amino Acids by Interpretation of Titration Curves: An Undergraduate Experiment for Biochemistry

Undergraduate biochemistry students should have great familiarity with titration curves. These curves allow the prediction of protonation states, charges, and isoelectric points. Here we describe an experiment in which students identify four amino acids based on their titration behavior. Students make solutions of each unknown amino acid and monitor the change in pH upon adding aliquots of a strong base. They identify the amino acids based on the shapes of the curves. They annotate the plots with isoelectric points, pKas, buffering regions and the structures of the amino acids

The Amazon Echo: Usability Evaluation

Background: The Amazon Echo is a home assistant device which allows people to interact verbally with online software tools or smart home devices and electronics. The purpose of this study was to test the usability of the device by conducting a variety of user-centered analyses. Method: Researchers performed a usability heuristics evaluation to gain an understanding of the system’s features and functions from a top-down perspective. An Out of Box Experience (OOBE) was conducted to capture users’ attitude of the device. Next, several tasks were performed which represent users\u27 everyday interactions with these devices. Participants then completed the system usability scale (SUS) to rate their experience. Results: Time on task was measured to analyze quantitative data and participants were asked to rate the difficulty of each task. Preliminary results indicate a setup time of approximately five minutes. Microsoft product reaction cards were used to capture initial and post-trial reactions to the device. Easy to use and efficient are two common terms appearing in the participant\u27s explanation of their feeling towards using the device. Conclusions: By collecting this information, our research team can paint an entire picture explaining benefits and flaws encountered by users and experts alike

Why People Are Not Willing to Let Their Children Ride in Driverless School Buses: A Gender and Nationality Comparison

As driverless vehicles proliferate, it is possible that this technology will be applied in mass transport vehicles. School buses may be suited for autonomous operations as they follow set routes and schedules. However, a research gap exists in whether or not parents would be willing to have their children ride in autonomously operated school buses. The purpose of this study was to examine parents’ willingness to allow their child to ride in an autonomous school bus. Participant gender and nationality were also two independent variables, along with affect measures as a possible mediating variable. The research used a two-study approach. In study one, it was found that participants were less willing to have their child ride in a driverless school bus than a traditional human-operated vehicle. In study two, findings suggest a significant interaction between the type of driver, participant gender, and nationality. In general, American females were less willing than Indian females and overall, Americans were less willing than Indians in the driverless conditions. Affect was found to be a mediating variable, which suggests that emotions were playing a role in the responses of participants. The paper concludes with theoretical contributions, practical applications, and suggestions for future research

Bacterial Growth Kinetics under a Novel Flexible Methacrylate Dressing Serving as a Drug Delivery Vehicle for Antiseptics

A flexible methacrylate powder dressing (Altrazeal®) transforms into a wound contour conforming matrix once in contact with wound exudate. We hypothesised that it may also serve as a drug delivery vehicle for antiseptics. The antimicrobial efficacy and influence on bacterial growth kinetics in combination with three antiseptics was investigated in an in vitro porcine wound model. Standardized in vitro wounds were contaminated with Staphylococcus aureus (MRSA; ATCC 33591) and divided into six groups: no dressing (negative control), methacrylate dressing alone, and combinations with application of 0.02% Polyhexamethylene Biguanide (PHMB), 0.4% PHMB, 0.1% PHMB + 0.1% betaine, 7.7 mg/mL Povidone-iodine (PVP-iodine), and 0.1% Octenidine-dihydrochloride (OCT) + 2% phenoxyethanol. Bacterial load per gram tissue was measured over five days. The highest reduction was observed with PVP-iodine at 24 h to log10 1.43 cfu/g, followed by OCT at 48 h to log10 2.41 cfu/g. Whilst 0.02% PHMB resulted in a stable bacterial load over 120 h to log10 4.00 cfu/g over 120 h, 0.1% PHMB + 0.1% betaine inhibited growth during the first 48 h, with slightly increasing bacterial numbers up to log10 5.38 cfu/g at 120 h. These results indicate that this flexible methacrylate dressing can be loaded with various antiseptics serving as drug delivery system. Depending on the selected combination, an individually shaped and controlled antibacterial effect may be achieved using the same type of wound dressing

A Preliminary Comparison of Pilots\u27 Weather Minimums and Actual Decision-Making

Adverse weather conditions remain a leading contributing factor in general aviation accidents. In compromising situations, such as severe weather, pilots continue to make decisions, which endanger themselves, passengers, and the aircraft. Although technology and training have lowered the risks associated with poor decision making by aviators, they are often still faced with scenarios requiring split second judgments. A countermeasure to these risks is the use of personal weather minimums by pilots. The purpose of this study was to examine pilot’s decision-making and performance, while flying an instrument approach, under extreme conditions of low visibility and ceiling as based on their stated personal minimums. A sample of 35 flight students with instrument ratings was recruited from a large university flight program located in the southeastern part of the United States. Participants were asked a series of pre-test questions, including their personal weather minimums, and then flew an ILS instrument approach on an Elite-1000 flight simulator at the subject university. The findings indicate approximately eighty percent of participants, on average, descended nearly two-hundred feet below their stated personal minimums before aborting the approach. Furthermore, forty percent of them also flew twenty-five feet below the federal requirement (200 feet above ground level) before aborting the approach. These results are pertinent to advance our understanding of the many different variables affecting pilot’s decision making. Understanding these outcomes will progress our initiatives to ensure safer air travel, while improving pilot’s competence and their passenger’s confidence

The role of social networks in students’ learning experiences

The aim of this research is to investigate the role of social networks in computer science education. The Internet shows great potential for enhancing collaboration between people and the role of social software has become increasingly relevant in recent years. This research focuses on analyzing the role that social networks play in students’ learning experiences. The construction of students’ social networks, the evolution of these networks, and their effects on the students’ learning experience in a university environment are examined

Incidence of Bladder Cancer in Sri Lanka: Analysis of the Cancer Registry Data and Review of the Incidence of Bladder Cancer in the South Asian Population

PurposeTo investigate the incidence of bladder cancer (BC) in Sri Lanka and to compare risk factors and outcomes with those of other South Asian nations and South Asian migrants to the United Kingdom (UK) and the United States (US).Materials and MethodsThe incidence of BC in Sri Lanka was examined by using two separate cancer registry databases over a 5-year period. Smoking rates were compiled by using a population-based survey from 2001 to 2009 and the relative risk was calculated by using published data.ResultsA total of 637 new cases of BC were diagnosed over the 5-year period. Sri Lankan BC incidence increased from 1985 but remained low (1.36 and 0.3 per 100,000 in males and females) and was similar to the incidence in other South Asian countries. The incidence was lower, however, than in migrant populations in the US and the UK. In densely populated districts of Sri Lanka, these rates almost doubled. Urothelial carcinoma accounted for 72%. The prevalence of male smokers in Sri Lanka was 39%, whereas Pakistan had higher smoking rates with a 6-fold increase in BC.ConclusionsSri Lankan BC incidence was low, similar to other South Asian countries (apart from Pakistan), but the actual incidence is likely higher than the cancer registry rates. Smoking is likely to be the main risk factor for BC. Possible under-reporting in rural areas could account for the low rates of BC in Sri Lanka. Any genetic or environmental protective effects of BC in South Asians seem to be lost on migration to the UK or the US and with higher levels of smoking, as seen in Pakistan

Mechanistic insight into proton-coupled mixed valency

Stabilisation of the mixed-valence state in [Mo2(TiPB)3(HDOP)]2+ (HTiPB = 2,4,6-triisopropylbenzoic acid, H2DOP = 3,6-dihydroxypyridazine) by electron transfer (ET) is related to the proton coordinate of the bridging ligands. Spectroelectrochemical studies suggest that ET is slower than 109 s−1. The mechanism has been probed using DFT calculations, which show that proton transfer induces a larger dipole in the molecule resulting in ET