Utilizing Instructional Consultations to Enhance the Teaching Performance of Engineering Faculty

Although many kinds of data can be used to guide instructional consultations, research comparing the efficacy of such data is scant, especially in engineering. In this study, multiple modes of assessment were used to evaluate the impact of consultations informed by different kinds of data. This study illuminates two key aspects of instructional consultations: (1) their efficacy varies depending on the kind of data used to guide them, with student feedback from a Small Group Instructional Diagnosis (SGID) having the largest positive impact, and (2) the instructional consultant plays a key role in helping both interpret the available data and identify strategies for improvement. These findings suggest three implications for practice: (1) whenever possible, SGID‐based consultations should be offered systematically and proactively for engineering faculty, (2) data for other kinds of consultations should be tailored to the needs of the individual instructor, and (3) instructional consultants should be available to collaborate with faculty to enhance their teaching, thereby building an engineering culture that actively supports teaching and learning.     

Organocatalytic Enantioselective Strecker Synthesis of α‐Quaternary α‐Trifluoromethyl Amino Acids

The first organocatalytic enantioselective Strecker synthesis of α‐quaternary α‐trifluoromethylated amino acids has been developed. Employing Takemoto’s thiourea catalyst the nucleophilic addition of trimethylsilyl cyanide to trifluoromethyl ketimines affords α‐amino nitriles in good to excellent yields (50–99%) and very good enantioselectivities (ee=83–95%). The enantiopure amino nitriles can be obtained by recrystallization. Deprotection and hydrolysis leads to the title amino acids.     

Inhibition of Eimeria tenella CDK‐Related Kinase 2: From Target Identification to Lead Compounds

Apicomplexan parasites encompass several human‐ and animal‐pathogenic protozoans such as Plasmodium falciparum, Toxoplasma gondii, and Eimeria tenella. E. tenella causes coccidiosis, a disease that afflicts chickens, leading to tremendous economic losses to the global poultry industry. The considerable increase in drug resistance makes it necessary to develop new therapeutic strategies against this parasite. Cyclin‐dependent kinases (CDKs) are key molecules in cell‐cycle regulation and are therefore prominent target proteins in parasitic diseases. Bioinformatics analysis revealed four potential CDK‐like proteins, of which one—E. tenella CDK‐related kinase 2 (EtCRK2)—has already been characterized by gene cloning and expression. 1 By using the CDK‐specific inhibitor flavopiridol in EtCRK2 enzyme assays and schizont maturation assays (SMA), we could chemically validate CDK‐like proteins as potential drug targets. An X‐ray crystal structure of human CDK2 (HsCDK2) served as a template to build protein models of EtCRK2 by comparative homology modeling. Structural differences in the ATP binding site between EtCRK2 and HsCDK2, as well as chicken CDK3, were addressed for the optimization of selective ATP‐competitive inhibitors. Virtual screening and “wet‐bench” high‐throughput screening campaigns on large compound libraries resulted in an initial set of hit compounds. These compounds were further analyzed and characterized, leading to a set of four promising lead compounds for development as EtCRK2 inhibitors.     

Linalool contents as characteristic of some flavor grade cocoas

Summary The terpenes present in cocoa flavour were analysed by means of gas chromatography-mass spectrometry. The pyranoid linalool oxides, ocimene and nerolidol, were identified for the first time as cocoa volatiles. Linalool, which is the major terpene component in cocoa contributes markedly to the flowery and tea-like flavour of some cocoa varieties. Flavour grade beans contain relatively high concentrations of linalool and basic grade cocoas possess. The isolation of linalool by means of intensive (simultaneous distillation extraction) and more gentle methods (vacuum condensation) yields similar quantitative results. The estimation of the concentration ratio of linalool/benzaldehyde within steam distillates ist suitable for the industrial quality control of unroasted cocoas.

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Linaloolgehalt als Merkmal einiger Edelkakaos

Zusammenfassung In Kakaoaroma wurden anhand GC/MS einige Terpene nachgewiesen, darunter erstmals auch die pyranoiden Linalooloxide, Ocimen und Nerolidol. Linalool als Hauptkomponente dieser Gruppe trägt wesentlich zum blumigen und tee-artigen Aroma einiger Kakaosorten bei. Edelkakaos weisen relativ hohe, Konsumkakaos niedrige Linalool-Konzentrationen auf. Die Isolierung von Linalool unter drastischen (simultane Destillation Extraktion) und milden Bedingungen (Vakuum-Kondensation) liefert ähnliche quantitative Ergebnisse. Die Bestimmung des Konzentrationsverhältnisses von Linalool/Benzaldehyd in Wasserdampfdestillaten eignet sich zur industriellen Qualitätskontrolle von Rohkakao.

     

Thickening of molten white chocolates during storage

When white chocolates are kept molten in storage tanks, problems can arise due to uncontrolled thickening and solidifying of the chocolate mass. The thickening of molten white chocolate was simulated on a laboratory scale using a rotational rheometer under static conditions, interrupted by short shear periods to measure the increasing viscosity. Several chocolates having different dairy components and fat contents were investigated for their tendency to thicken. In addition, sorption isotherms for white chocolates were obtained using dynamic vapour sorption at different temperatures. The sorption isotherms showed the presence of amorphous lactose in all the chocolates that were manufactured from milk powders. Moisture that is released during the crystallization of amorphous lactose causes stickiness and agglomeration of the neighbouring particles and starts the thickening process. This process is highly temperature-dependent. On elevating the temperature the lactose crystallization occurs at lower relative humidities. In order to reduce the tendency of white chocolate to thicken, a high free-fat level should be maintained, based on a high total fat content and on the use of high free-fat milk powders, preferably roller-dried whole milk powders or the combination of skimmed milk powder and anhydrous milk fat.     

Buchbesprechungen

Ohne Zusammenfassung     

Semantic failure [of software]

The author offers the opinion that the adoption of the terminology of hardware reliability in the context of software was a terrible, probably unavoidable, and perhaps even necessary, mistake: terrible-because the words cannot have the same meanings in both contexts; and unavoidable-because today there are few systems whose reliability can be assessed without dealing with both     

Sensitivity of computed tomography in detecting local recurrence of prostatic carcinoma following radical prostatectomy

The aim of this study was to evaluate CT imaging in the post-operative follow-up and in the detection of recurrence after radical prostatectomy in cases of prostatic carcinoma. In over 500 patients undergoing radical prostatectomy for prostatic carcinoma, 22 cases with local recurrence were found. CT examinations of the pelvis were retrospectively evaluated in these patients. Local recurrence was detected by PSA uptake and confirmed by transrectal ultrasound (TRUS) in combination with guided biopsy. In 22 cases of confirmed local recurrence, positive results on CT were found in eight patients (36%) and negative results in nine patients (41%). In the remaining five cases (23%), no distinction could be made between scar and local recurrence. All cases definitively classified as recurrent tumour disease showed a soft tissue mass of 2 cm or more. CT sensitivity in local recurrence of prostatic carcinoma after surgery is low. Even in a very careful follow-up, the understaging would be up to 41%. In comparison, PSA, TRUS and needle biopsy are the methods of choice and are superior to CT imaging. Based on these results, there would be no reason for including pelvic CT examinations in the follow-up of prostatic carcinoma after radical prostatectomy.     

Separation of stat-copoly(styrene/2-methoxyethyl methacrylate) samples according to composition by gradient high-performance liquid chromatography

Statistical copolymers of styrene (S) and 2-methoxyethyl methacrylate (MEMA) (13–87 mass % of the latter monomer) were investigated by gradient HPLC on columns with either silica or CN-bonded phase packings. The samples were injected in THF solution. The starting eluent was in each case a nonsolvent (isooctane or mixtures of isooctane with THF and methanol). Separation was achieved by increasing the concentration of THF or methanol in the eluent. A calibration mixture of four copolymers (26, 49, 62, and 87% MEMA) was investigated according to the principles of chromatographic cross-fractionation (CCF) by size exclusion chromatography and subsequent gradient HPLC. The influence of molar mass on HPLC retention was small and, for the samples investigated by CCF, independent of copolymer composition. The composition effect on detector signal was also studied. At 230 nm wavelength and with MEMA content in the range between 20 and 40%, the effect was small and caused the average composition calculated from CCF results to deviate from the directly measured value by not more than 0.2 or 0.8% for the two copolymers investigated.