bluuebunny/crossref_metadata_2025 huggingface dataset:
Nanotech for Fertilizers and Nutrients-Improving Nutrient use Efficiency with Nano-Enabled Fertilizers
Authors: Singh Manish , Goswami Suhana Puri , Ranjitha G.  , Sachan Prashun , Sahu Devid Kumar , Beese Shreedhar , Pandey Shivam Kumar
Published: March 2024

The development of nano-enabled fertilizers presents new opportunities to improve crop nutrient use efficiency and reduce environmental impacts of agriculture. Nanoparticles, nano capsules, and nano clays can be engineered to control the release rate of nutrients to better match crop demands over time. Slow-release nano fertilizers may enhance nutrient absorption by plants while mitigating nutrient losses to the environment. Additionally, nano fertilizers can facilitate co-delivery of nutrients, growth regulators, and pesticides, allowing for more precise crop management practices. This review synthesizes current research on synthesis techniques, characterization methods, and agronomic testing results for a range of nano fertilizer products. Key nutrient carriers reviewed include mesoporous silica nanoparticles, layered double hydroxides, cellulose nanocrystals, and halloysite nanotubes loaded with nitrogen, phosphorus, potassium, and micronutrients. Release kinetics depend on nano fertilizer composition, size, and shape, as well as environmental conditions. Field studies indicate positive impacts of nano fertilizers on crop yield, nutrient use efficiency, and pest resistance compared to conventional fertilizer formulations. However, questions remain regarding large-scale feasibility, economic viability, environmental fate, and biological impacts of nano-enabled fertilizers. Ongoing interdisciplinary research across the domains of materials science, agronomy, ecology, and economics is required to develop nano fertilizers that maximize production efficiency while minimizing risks.
The fatty acid amide hydrolase C385A (P129T) missense variant in cannabis users: Studies of drug use and dependence in caucasians
Authors: Tyndale Rachel F. , Payne Jennifer I. , Gerber Alexandra L. , Sipe Jack C.
Published: February 2007

A genetic variation in fatty acid amide hydrolase (FAAH), C385A (P129T), has been previously associated with risk for problem street drug use. FAAH is a mammalian enzyme that inactivates neuromodulatory‐signaling lipids including the endogenous cannabinoid 1 receptor agonist anandamide. We investigated in adult Caucasians (N = 749) whether this FAAH variant altered the risk for trying, regular use of or dependence on cannabis, alcohol or nicotine, traditional “gateway” drugs. Consistent with our knowledge that the A/A genotype results in reduced FAAH expression and activity in humans, subjects with the A/A genotype were less likely to be THC dependent than subjects with either a C/C or C/A genotype (11% vs. 26%, P < 0.05). No association was observed between the A/A genotype and risk for alcohol or tobacco regular use, or DSM IV dependence. Controlling for regular use of nicotine and sedatives, both identified as confounders, those with the A/A genotype were at significantly reduced risk for being THC dependent (OR 0.25, 95% CI: 0.07–0.88) as compared with those with the C/A or C/C genotype, supporting a link between alterations in the endocannabinoid system and THC dependence. Unexpectedly, we found an increased risk for regular use of sedatives among the A/A genotype group. The relationship between the FAAH A/A genotype and risk for drug dependence in this study was drug class specific, suggesting it is not part of a more general drug abuse effect. These results, particularly the observation of altered risk for sedative drug use, should be investigated further in multiple ethnic populations. © 2007 Wiley‐Liss, Inc.
Assessment of menstruation in the vervet (Cercopithecus aethiops)
Authors: Carroll Rebecca L. , Mah Kunie , Fanton John W. , Maginnis Gwendalyn N. , Brenner Robert M , Slayden Ov D.
Published: February 2007

Vervet monkeys (Chlorocebus aethiops) are Old World nonhumans that display attenuated menstruation that requires detection by vaginal swab. The physiology underlying attenuated menstruation in this species has not been previously studied. To fill this gap, we evaluated endometrial cell proliferation, steroid receptor localization and expression of menstruation‐associated matrix metalloproteinase (MMP) enzymes in vervets during natural and artificial menstrual cycles. The artificial cycles were induced by sequentially treating ovariectomized animals with estradiol (E2) and progesterone (P). Because menstrual flow is exceptionally light in this species, menses was detected by vaginal swab. We found that both natural and artificially cycled animals menstruated 3–5 days after the decline of P at the end of the cycle. As in other primates, P withdrawal at the end of artificial cycles triggered endometrial expression of MMPs, including MMP‐1, 2, 3, 7, 10, 11, 13 and 26 transcripts. In both the natural and artificial menstrual cycle, menstrual sloughing was restricted to the upper one‐fourth of the endometrium, and MMP‐1 and 2 were strongly expressed by the stroma of the sloughing zone. MMP‐7 was localized in the endometrial glands during late menses. As in macaques, epithelial cell proliferation was localized to the functionalis zone during the estrogen‐dominated proliferative phase and to the basalis zone glands during the P‐dominated secretory phase. Regulation of estrogen and progestin (or estradiol and progesterone) receptors was similar to that reported for macaques. Because strong similarities exist between the endometrium of vervets, macaques and women, we conclude that vervets can provide a useful animal model for studies on hormone regulation of menstruation. Am. J. Primatol. 69:901–916, 2007. © 2007 Wiley‐Liss, Inc.
Habitat use and social structure of a brown lemur hybrid population in the Berenty Reserve, Madagascar
Authors: Tanaka Mikiko
Published: February 2007

The population of brown lemurs has rapidly grown since their founders were introduced to the Berenty Reserve. The founders consist of two species (Eulemur fulvus rufus and E. collaris). To characterize the behavior of the population and to examine whether these characteristics affect population growth, I investigated the habitat use and social structure of the population of brown lemurs at Berenty (Berenty Eulemur). Behavior data were collected focusing on horizontal and vertical habitat use, activity rhythms, and intergroup relationships. These data were compared with the data of E. fulvus in other areas, with the previous studies done at Berenty, and with data on Berenty Lemur catta. Berenty Eulemur maintained a home range size comparable to E. f. rufus in the western deciduous dry forest, but was found at a lower level of the forest and had larger overlapping home ranges. Berenty Eulemur use food resources earlier in the morning than L. catta, intergroup conflict was avoided by vocal communication, and Berenty Eulemur made suitable use of their limited habitat. I suggest that a number of behavioral characteristics of Berenty Eulemur may contribute to their population growth. Am. J. Primatol. 69:1189–1194, 2007. © 2007 Wiley‐Liss, Inc.
First evidence for relocation of stationary food resources during foraging in a strepsirhine primate (Microcebus murinus)
Authors: Joly Marine , Zimmermann Elke
Published: February 2007

Field observations suggest that the diet of the Malagasy gray mouse lemur consists not only of non‐stationary animal prey (invertebrates or small vertebrates), but also of stationary food resources such as gum or homopteran larvae secretions (HLS). We studied the foraging behavior of five mouse lemurs radiotelemetrically, each during six consecutive nights in the dry season, to explore to which extent they use these food resources and whether there is evidence for their relocation. We found that animals used all three different food categories. Mouse lemurs fed on gums and spent 68.5% (range 20.1–99.7%) of their feeding time eating this item. They were observed eating HLS in 8.4% (range 0–71.5%) of the feeding time and consuming small animals in 8.4% (range 0.3–26%) of their feeding time. The animals relocated stationary feeding sites significantly more frequently than non‐stationary ones. They revisited the relocated stationary food sites about five times over the six nights. Furthermore, departure directions when leaving the sleeping site at dusk were not randomly distributed but showed a preferred orientation. Altogether, we provided first evidence for the relocation of stationary food resources in nature and thereby for the potential significance of spatial memory during foraging in a strepsirhine primate. Am. J. Primatol. 69:1045–1052, 2007. © 2007 Wiley‐Liss, Inc.
Die Woodward‐Doering‐/Rabe‐Kindler‐Totalsynthese von Chinin: ein Mythos?
Authors: Seeman Jeffrey I.
Published: February 2007

1918 beschrieben Paul Rabe und Karl Kindler die dreistufige Umwandlung von d‐Chinotoxin in Chinin. Robert B. Woodward und William von Eggers Doering veröffentlichten 1944 die Totalsynthese von Homomerochinen und d‐Chinotoxin aus 7‐Hydroxyisochinolin. Auf der Grundlage der Umsetzungen von Rabe und Kindler beanspruchten Woodward und Doering im Titel zweier Arbeiten von 1944 und 1945 die “Total Synthesis of Quinine”. In den Jahren 2000 und 2001 stempelte Gilbert Stork Woodwards und Doerings Anspruch aber als ungültig, weil sie in Cambridge nur Homomerochinen und d‐Chinotoxin, nicht aber synthetisches Chinin hergestellt hatten. Tatsächlich haben Rabe und Kindler die experimentellen Einzelheiten ihrer Umwandlung von d‐Chinotoxin in Chinin nie veröffentlicht. Dieser Aufsatz stellt die Ergebnisse einer detaillierten Untersuchung der Synthesechemie von Cinchona‐Alkaloiden vor und gibt anhand von bisher unveröffentlichtem Material sowie zahlreichen Interviews einen Einblick in das Leben der Hauptpersonen dieser fast 100 Jahre währenden Geschichte.
Titelbild: Cross‐Linked Layered Structure of Magnetically Ordered [Fe(TCNE)2]⋅z CH2Cl2 Determined by Rietveld Refinement of Synchrotron Powder Diffraction Data (Angew. Chem. 9/2007)
Authors: Her Jae‐Hyuk , Stephens Peter W. , Pokhodnya Konstantin I. , Bonner Michael , Miller Joel S.
Published: February 2007

Ein Schichtmagnet entsteht bei der Reaktion von Tetracyanethylen (TCNE; linker Schenkel) mit [Fe(CO)5] (rechter Schenkel). Die von P. W. Stephens, J. S. Miller et al. in ihrer Zuschrift auf S. 1543 ff. beschriebene Strukturanalyse ergab, dass magnetische Schichten aus [TCNE].−, die an vier High‐Spin‐FeII‐Ionen binden, durch [C4(CN)8]2−–das diamagnetische σ‐Dimer von [TCNE].−–verknüpft sind. Diese Struktur erklärt die unerwartet hohe Magnetisierung dieses Ferrimagneten.
Cover Picture: Cross‐Linked Layered Structure of Magnetically Ordered [Fe(TCNE)2]⋅z CH2Cl2 Determined by Rietveld Refinement of Synchrotron Powder Diffraction Data (Angew. Chem. Int. Ed. 9/2007)
Authors: Her Jae‐Hyuk , Stephens Peter W. , Pokhodnya Konstantin I. , Bonner Michael , Miller Joel S.
Published: February 2007

A layered magnet is formed from the reaction (see H‐tube apparatus; bottom) of tetracyanoethylene (TCNE; left) and [Fe(CO)5] (right). The structural elucidation described by P. W. Stephens, J. S. Miller, and co‐workers in their Communication on page 1521 ff. reveals that magnetic layers of [TCNE].− bonded to four high‐spin FeII ions are connected by [C4(CN)8]2−, the diamagnetic σ dimer of [TCNE].−, which explains the higher than expected magnetization for this ferrimagnet.
Evidence for two‐step regulation of pheromone biosynthesis by the pheromone biosynthesis‐activating neuropeptide in the moth Heliothis virescens
Authors: Eltahlawy H. , Buckner J.S. , Foster S.P.
Published: February 2007

The control of pheromone biosynthesis by the neuropeptide PBAN was investigated in the moth Heliothis virescens. When decapitated females were injected with [2‐14C] acetate, females co‐injected with PBAN produced significantly greater quantities of radiolabeled fatty acids in their pheromone gland than females co‐injected with saline. This indicates that PBAN controls an enzyme involved in the synthesis of fatty acids, probably acetyl CoA carboxylase. Decapitated females injected with PBAN showed a rapid increase in native pheromone, and a slower increase in the pheromone precursor, (Z)‐11‐hexadecenoate. Total native palmitate and stearate (both pheromone intermediates) showed a significant decrease after PBAN injection, before their titers were later restored to initial levels. In contrast, the acyl‐CoA thioesters of these two saturated fatty acids increased during the period when their total titers decreased. When a mixture of labeled palmitic and heptadecanoic (an acid that cannot be converted to pheromone) acids was applied to the gland, PBAN‐injected females produced greater quantities of labeled pheromone and precursor than did saline‐injected ones. The two acids showed similar time‐course patterns, with no difference in total titers of each of the respective acids between saline‐ and PBAN‐injected females. When labeled heptadecanoic acid was applied to the gland alone, there was no difference in titers of either total heptadecanoate or of heptadecanoyl‐CoA between PBAN‐ and saline‐injected females, suggesting that PBAN does not directly control the storage or liberation of fatty acids in the gland, at least for this fatty acid. Overall, these data indicate that PBAN also controls a later step involved in pheromone biosynthesis, perhaps the reduction of acyl‐CoA moieties. The control by PBAN of two enzymes, near the beginning and end of the pheromone biosynthetic process, would seem to allow for more efficient utilization of fatty acids and pheromone than control of only one enzyme. Arch. Insect Biochem. Physiol. 64:120–130, 2007. Published 2007 Wiley‐Liss, Inc.
Gonadoinhibitory effects of Neb‐colloostatin and Neb‐TMOF on ovarian development in the mealworm, Tenebrio molitor L.
Authors: Wasielewski O. , Rosiński G.
Published: February 2007

The gonadostatic action of the peptides Neb‐colloostatin (SIVPLGLPVPIGPIVVGPR) and Neb‐TMOF (NPTNLH) from Neobellieria bullata was studied in female mealworm Tenebrio molitor. Both peptides potently inhibit ovarian development and terminal oocyte maturation of mated females during their first reproductive cycle. Injection of 4 μg of Neb‐colloostatin or Neb‐TMOFNeb‐TMOF reduced, at day 4 of the cycle, the size of the terminal oocytes to about half or one third of the normal size in saline‐injected controls. In addition, follicular patency was arrested. The injections of Neb‐colloostatin and Neb‐TMOF also caused a delay to the first ovulation and oviposition as well as a reduction of the number of eggs by about 50% in the first 3 days of the oviposition period. At 4 days after adult emergence, none of the peptides had caused significant changes in protein concentration or composition of the haemolymph. However, both peptides reduced total protein content in ovaries and induced qualitative changes in ovarian protein patterns. Electrophoretic analyses indicated that Neb‐colloostatin and Neb‐TMOF caused a loss of two proteins (150, 180 kDa) and a drastic reduction of 4 others (39, 43, 47, 130 kDa), which are the most abundant ones in ovaries of control females. On the other hand, they increased the concentration of 2 other polypeptides (65, 70 kDa), which normally occur in insignificant quantities in ovaries. Our results indicate that both peptides have a very similar mode of action despite the differences in their amino acid sequence. They seem to interfere with vitellogenin production by the fat body as well as with vitellogen uptake by the oocytes through modification of patency. Arch. Insect Biochem. Physiol. 64:131–141, 2007. © 2007 Wiley‐Liss, Inc.
Synthesis of New 2‐Phenyladenines and 2‐Phenylpteridines and Biological Evaluation as Adenosine Receptor Ligands
Authors: Giorgi Irene , Biagi Giuliana , Livi Oreste , Leonardi Michele , Scartoni Valerio , Pietra Daniele
Published: February 2007

Synthesis and biological assays of a series of 2‐phenylpteridine derivatives are described to compare their affinities to adenosine receptors with those of the corresponding adenines, purposely prepared, and 8‐azaadenines previously described. This study demonstrates that the enlargement of the five‐membered ring of the adenine nucleus to a six‐membered one is a modification that does not allow the molecules to maintain high activity towards adenosine receptors; in fact, pteridine derivatives did not show themselves to be good adenosine receptor ligands. On the contrary, N6‐cycloalkyl‐ or N6‐alkyl‐2‐phenyladenines showed a very high affinity and selectivity for A1 adenosine receptors. We demonstrate also that the 9‐benzyl substituent is crucial for conferring high affinity for A3 receptors to molecules having a 2‐phenyladenine‐like nucleus.
Ethnomethodological architectures: Information systems driven by cultural and community visions
Authors: Srinivasan Ramesh
Published: February 2007

As networked digital systems are rapidly created and deployed, social, cultural, and community‐focused issues are often neglected. Indeed much research has focused on the “effects” these systems hold rather than viewing systems as tools to be designed given an understanding of sociocultural context. Acknowledging the cultural practices and belief systems of a set of users may allow systems to be more effectively created and deployed into particular contexts. Emerging research in community information systems and archives has highlighted possible interactions between system design and ethnographic research. These bridges include understanding how communities can begin (1) to create content for their own information systems, (2) to design the database architectures, and (3) to integrate systems within community infrastructures. In this article, I allude to several cultural criticisms that accompany the global proliferation of information technologies. These criticisms can be answered by research that focuses on developing systems based on ethnographic insights. Specifically, I present the research example of Tribal Peace, a cultural information system designed for and by community members of the 19 Native American reservations of San Diego County (California, United States). This case has demonstrated the potential for a community to create an information system that satisfies its own priorities. This precedent points to the need for further research that investigates this convergence.
Production of axial skeletal malformations with the nitric oxide synthesis inhibitor NG‐nitro‐L‐arginine methyl ester (L‐NAME) in the mouse
Authors: Tiboni Gian Mario , Marotta Francesca , Barbacane Lisa
Published: February 2007

BACKGROUND:To test whether the differentiating embryo is susceptible to the teratogenic effects of the nitric oxide (NO) synthesis inhibitor NG‐nitro‐L‐arginine methyl ester (L‐NAME).METHODS:ICR‐(CD‐1) mice received a single intraperitoneal injection ofL‐NAME at 90, 150, or 300 mg/kg on Gestation Day (GD) 8 or 9. Controls were treated with vehicle on GD 8 and 9. Teratological assessments were carried out near term (GD 18).RESULTS:Maternal treatment with a single dose ofL‐NAME at 150 or 300 mg/kg on either GD 8 or 9 produced axial skeletal defects in the ICR (CD‐1) mouse fetuses. Other treatment‐related effects included increased embryo lethality and fetal growth restriction.CONCLUSIONS:This study provides evidence that in utero exposure toL‐NAME can affect organogenesis of the axial skeleton.Birth Defects Res (Part B)80:28–33, 2007. © 2007 Wiley‐Liss, Inc.
Landmark discoveries in the trail from chemistry to cellular biochemistry, with particular reference to mileposts in research on bioenergetics
Authors: Gest Howard
Published: February 2007

Molecular oxygen was discovered in 1775 by Joseph Priestley. He also made the important observations that oxygen is produced by plants and that gases (O2 and CO2) mediate the interdependence of plant and animal life. The biological experiments of Priestley dealt with aerobes, the most advanced forms of life. It was the research of Louis Pasteur, however, on fermentation of sugar by anaerobic microbes that provided a system that was the first to reveal significant clues to the biochemistry of bioenergetics. Analysis of the detailed mechanism of anaerobic sugar fermentation by yeast during the first third of the 20th century and the later study of energy‐yielding aerobic respiration and energy conversion in photosynthesis required development of many new techniques. These became the tools that were exploited to yield the basic outlines of cell biochemistry. Included were chromatography, metabolic gas manometry, spectrophotometry, the use of stable and radioactive isotopes as tracers of intermediary metabolism, and procedures for purification of proteins and other macromolecules. Noteworthy advances included discovery and characterization of the (Krebs) tricarboxylic acid cycle, “activated” intermediates such as acetyl coenzyme A, electron carriers and coenzymes necessary for energy conversion and reductive biosynthesis, ATP (the universal energy “currency”) and a multitude of enzymes involved in catabolic and biosynthetic metabolism.
On the error of the dixon plot for estimating the inhibition constant between enzyme and inhibitor
Authors: Fukushima Yoshihiro , Ushimaru Makoto , Takahara Satoshi
Published: February 2007

In textbook treatments of enzyme inhibition kinetics, adjustment of the initial inhibitor concentration for inhibitor bound to enzyme is often neglected. For example, in graphical plots such as the Dixon plot for estimation of an inhibition constant, the initial concentration of inhibitor is usually plotted instead of the true inhibitor concentration. Justification for this approximation should be presented to students, because in certain conditions it can be inaccurate.
Using a homemade spectrophotometer in teaching biosciences
Authors: Lema Martín A. , Aljinovic Ernesto M. , Lozano Mario E.
Published: February 2007

In this article a homemade spectrophotometer that can be made of inexpensive components available to everyone is presented. This apparatus can be used to implement several low cost standard biochemical and biological experiences like quantitation of biomolecules, the study of biological pigments, and following the time plot of an enzymatic reaction or the growing kinetics of microorganisms.
Student difficulties with the interpretation of a textbook diagram of immunoglobulin G (IgG)*
Authors: Schönborn Konrad J. , Anderson Trevor R. , Grayson Diane J.
Published: February 2007

Diagrams are considered to be invaluable teaching and learning tools in biochemistry, because they help learners build mental models of phenomena, which allows for comprehension and integration of scientific concepts. Sometimes, however, students experience difficulties with the interpretation of diagrams, which may have a negative effect on their learning of science. This paper reports on three categories of difficulties encountered by students with the interpretation of a stylized textbook diagram of the structure of immunoglobulin G (IgG). The difficulties were identified and classified using the four‐level framework of Grayson et al. [1]. Possible factors affecting the ability of students to interpret the diagram, and various teaching and learning strategies that might remediate the difficulties are also discussed.
The molecular pathomechanism of tay‐sachs disease
Authors: Szeberényi József
Published: February 2007

Terms to be familiar with before you start to solve the test: lysosomes, lysosomal storage diseases, Tay‐Sachs disease, insertion, frame‐shift mutation, stop‐codon, U4 snRNA, Northern blot analysis, cell fractionation, RNA splicing, hypopycnic gradient centrifugation, polysomes, nucleosomes, protein synthesis.

This paper is available on line at http://www.bambed.org
A modeling and simulation approach to the study of metabolic control analysis
Authors: Rodríguez‐Caso Carlos , Sánchez‐Jiménez Francisca , Medina Miguel Ángel
Published: February 2007

Metabolic control analysis has contributed to the rapid advance in our understanding of metabolic regulation. However, up to now this topic has not been covered properly in biochemistry courses. This work reports the development and implementation of a practical lesson on metabolic control analysis using modeling and simulation.

The abbreviation used is: MCA, metabolic control analysis.
Optimization of kinetic parameters of enzymes
Authors: Heinrich Reinhart , Meléndez‐Hevia Enrique , Cabezas Héctor
Published: February 2007

Enzymes are a product of evolution, having achieved a high specificity and catalytic performance by means of natural selection. Because catalytic mechanisms are very complex, a detailed and rigorous analysis of their optimization functions, as it has been developed in our previous work, is rather difficult for teaching purposes. In this paper we present a summarized and simplified view of our results by means of analyzing the optimization of kinetic parameters of a two‐step enzyme mechanism under a set of several constraints. This analysis is presented in a way that makes it useful for teaching, as students can understand it easily, make the calculations, and even develop it by exploring new environmental conditions. The analysis of the optimization processes is presented through two calculation tools, analysis and computer programming.
Bridging the gap in biochemistry between secondary school and university
Authors: Fernàndez‐Novell Josep M. , Gomis Roger R. , Cid Emili , Barberà Albert , Guinovart Joan J.
Published: February 2007

This manuscript describes a new strategy for introducing secondary school students to biochemistry. To bridge the gap between secondary education and the university, the Department of Biochemistry and Molecular Biology of the University of Barcelona, in collaboration with the SEBBM (The Spanish Society for Biochemistry and Molecular Biology), designed a course with lectures and practical classes for students in their last year of secondary school. The impact of this course on society has been considerable, and it is now a reference model for other disciplines.
Using three‐dimensional imaging of proteins: Examples of class activities and subsequent assessments
Authors: Willian Kyle R.
Published: February 2007

This paper discusses the development of a new biochemistry course, “Biochemistry of Cellular Regulation,” which is taught at the 300 level at Tuskegee University. The chemistry of cellular signaling and the subsequent cell regulation are discussed from a molecular viewpoint with emphasis on chemical structure, reactivity, and thermodynamics. Classroom lectures are composed almost entirely of PowerPoint lectures whereby figures from the textbook and figures from current research articles are incorporated directly into the lecture notes. The incorporation of supplemental materials from the textbook, i.e. the CD‐ROM and websites from the CD‐ROM was especially important. Three‐dimensional images of proteins can be viewed and manipulated at these websites, which is critical for understanding the structural basis of protein function. Specific examples of class activities and subsequent assessments will be presented.
Redox‐active disulfides in a plant light switch: A Pbl problem*
Authors: Offmann Bernard , Cadet Frédéric
Published: February 2007

A problem for students on the mode of activation of light‐regulated NADP‐dependent malate dehydrogenase is presented here as a series of questions requiring the interpretation of experimental data.
The free energy of denaturation of lysozyme: An undergraduate experiment in biophysical chemistry*
Authors: Kurtin William E. , Lee John M.
Published: February 2007

An undergraduate laboratory experiment to measure the free energy of denaturation of the enzyme lysozyme is described. The fluorescence of the protein in solutions of varying concentrations of urea and guanidine hydrochloride is measured. The data are analyzed graphically assuming a two‐state model for the denaturation.
Effectiveness of conceptual change text‐oriented instruction on students' understanding of cellular respiration concepts
Authors: Çakir Özlem S. , Geban Ömer , Yürük Nejla
Published: February 2007

This study investigated the effect of conceptual change text‐oriented instruction over traditional instruction on students' understanding of cellular respiration concepts and their attitudes toward biology as a school subject. The sample of this study consisted of 84 eleventh‐grade students from four classes of a high school. Two of the classes were assigned randomly to the control group, and the other two classes were assigned randomly to the experimental group. During teaching the topic of cellular respiration concepts in biology curriculum, the experimental group was taught with the conceptual change text‐oriented instruction whereas the control group was taught with the traditional instruction. The results showed that the students in the experimental group performed better with respect to cellular respiration concepts. In addition, it has been found that there was no significant difference between the attitudes of students in the experimental and control groups toward biology as a school subject.
Plants versus animals in the dining hall: A problem‐based learning problem
Authors: White Harold B.
Published: February 2007

This five‐stage problem explores amino acid metabolism in the context of a story about a college student who chooses to become a vegetarian against the best wishes of her mother. It requires students to analyze isotopic data from classic experiments in nutritional biochemistry and explain the results in terms of now known metabolic pathways. It provides an evolutionary perspective on the meaning of essential and nonessential amino acids and on the production of secondary metabolites from amino acids by plants. Groups of students working in a problem‐based learning environment integrate these ideas into concept map to complete the problem.
Oxidation numbers in the study of metabolism
Authors: Bentley Ronald , Franzen James , Chasteen Thomas G.
Published: February 2007

The calculation and use of oxidation numbers in the study of metabolic reactions are discussed for normal oxidations (alcohol dehydrogenase and the NAD+/NADH couple, propanediol dehydratase) and for enzymatic reactions with a “hidden” redox component (transamination, the coupled conversion of ethylamine to ethanol, and the biomethylation of arsenic and selenium).
Turning biochemistry inside out: A new approach to teaching metabolism in the post‐genomic era
Authors: Gerrard Juliet A. , Sparrow Ashley D.
Published: February 2007

This article describes a new approach to teaching metabolic pathways, designed to engage students with the material, and its complexities. Based on a novel way of presenting metabolic pathways, in which the focus is placed on proteins rather than metabolites [1], simple tutorial‐based exercises and mini‐projects are described, bringing metabolism to life, yet requiring very few resources.
Promotion of photodynamic therapy‐induced death: Laboratory experimental methodology
Authors: Vittar Natalia Belén Rumie , Galetto Román , Yslas Edith Inés , Durantini Edgardo Néstor , Rivarola Viviana
Published: February 2007

Photodynamic therapy, a cancer treatment using a photosensitizer and visible light, has been shown to induce apoptosis or necrosis. In the present paper we recommend the use of a phthalocyanine derivative in an experimental class with the purpose of introducing students to photodynamic treatment of cultured cells, morphological observation of cell death, and viability assays. We consider that this activity might help students trained previously in tissue culture handling to experience a richer way of learning concepts and techniques.
Isolation and visualization of nucleic acid with homemade apparatus: Practical activities for secondary schools
Authors: Sepel Lenira M. N. , Loreto Elgion L. S.
Published: February 2007

In many developing countries one of the major problems in the teaching science is the lack of adequate equipment and reagents. One way to solve the problem of the absence of laboratory equipment is to develop practical classes in which students construct some of the equipment needed for the students to understand abstract topics in molecular biology. In this article we describe how students can be motivated to construct a microcentrifuge and electrophoresis apparatus with simple materials. We also give details of two practical activities (nucleic acid extraction and the separation of DNA and RNA by agarose gel electrophoresis) that use common non‐hazardous household substances and only a few laboratory reagents. Some questions for the students to answer after the practical activities are also presented.
Coming to terms with biocapitalism: Norms and idiosyncrasies of a molecular biology patent
Authors: Candlish John
Published: February 2007

It is pointed out that biochemists and molecular biologists embarking on full time research should be able to respond constructively to the current pressure for commercial exploitation of their achievements, in the form of patents. Learning to do an adequate search and draft an application will save time and money. The requirements of novelty, inventive step, and usefulness are explained briefly. Priority in the event of dispute will hinge on either being first to file or first to invent, with the latter depending on the integrity of the laboratory notebook. Safeguards against premature disclosure are explained. Some idiosyncrasies of biotechnology patents are discussed, as is the importance of identifying a licensee.
Transcriptional and posttranslational regulation of a membrane nutrient transporter
Authors: Stambuk Boris U.
Published: February 2007

A laboratory exercise illustrating the metabolic regulation of a plasma membrane transporter was devised. A simple colorimetric assay allows the determination of the yeast maltose permease activity under different conditions, and thus the induction of the transporter by maltose and its repression by glucose can be easily demonstrated. The laboratory exercise also shows that glucose regulates the expression of the transporter at the plasma membrane by promoting its inactivation and endocytosis. The intracellular trafficking of the transporter under these conditions can be further illustrated using a maltose permease tagged with the green fluorescent protein.

The abbreviations used are: 2‐dGlu, 2‐deoxy‐D‐glucose, GFP, green fluorescent protein; pNPαG, p‐nitrophenyl‐α‐D‐glucopyranoside; YNB, yeast nitrogen base without amino acids and ammonium sulfate.
Biochemistry of neuromuscular diseases: A course for undergraduate students*
Authors: Ohlendieck Kay
Published: February 2007

This article outlines an undergraduate course focusing on supramolecular membrane protein complexes involved in the molecular pathogenesis of neuromuscular disorders. The emphasis of this course is to introduce students to the key elements involved in the ion regulation and membrane stabilization during muscle contraction and the role of these proteins in the pathobiochemistry of selected muscle diseases. Individual sections of the course involve the detailed analysis of the molecular mechanisms underlying disorders related to myasthenia gravis, malignant hyperthermia, and dystrophinopathies. An introduction into modern biochemical, molecular biological, and pharmacological methodology used in the study of neuromuscular diseases is also provided. The potential sites for genetic, cell biological, and pharmacological interventions at different steps of the disease process are discussed. Experimental approaches to designing new therapeutic strategies such as gene and myoblast transfer therapy are evaluated using Duchenne muscular dystrophy and its related disorders as an example. The course emphasizes the need for understanding the cause and molecular mechanisms involved in specific muscle diseases to exploit this knowledge in developing more accurate diagnostic tests and most importantly to evaluate novel attempts at treating devastating muscular disorders.
Use of a chloroplast rRNA gene to introduce basic molecular biology techniques
Authors: Nielsen Brent L. , Echols Sean D.
Published: February 2007

We report a set of experiments that has been used for 14 years in an upper division undergraduate molecular biology laboratory course to introduce basic molecular biology techniques including DNA isolation, gene subcloning, restriction mapping, plant genomic DNA isolation, Southern blot hybridization, and DNA sequence analysis. This set of experiments is very useful for students who have limited or no previous experience with these techniques. A single gene, the 23S rRNA gene from tobacco chloroplast DNA, is used throughout these experiments. This allows for integration of the techniques and illustrates to students a natural progression of experiments to use in analyzing a new gene. The entire sequence of laboratory exercises spans 10–12 laboratory periods of 2.5–3 h each.
Using the cell signaling literature to teach molecular biology to undergraduates
Authors: Smith Catherine Novotny
Published: February 2007

Molecular biology concepts can be quite abstract and difficult to grasp for even the most talented student. Reducing potential frustration in the learning process, allowing students to take ownership of the course material, and training students to think critically and analytically are common objectives for educators. In this article, pedagogical methods that incorporate the scientific literature to achieve these objectives are described.
A simple way to visualize fibrinolysis in the classroom*
Authors: Nurachman Zeily , Hermawan Jatnika , Rachmayanti Yanti , Baradja Lubna
Published: February 2007

Laboratory demonstration, as well as biochemistry lecture, has been used to complement explanation of biochemical processes. The laboratory demonstration is very useful in teaching biochemistry to students who lack background in biology. The experimental model of fibrinolysis described here presents a complex biological reaction in simplified manner, emphasizing specific terms related to enzymes, and triggers student interest in biochemistry.
The problem with problem‐based medical education: Promises not kept
Authors: Glew Robert H.
Published: February 2007

More than a decade after a student‐centered, problem‐based learning (PBL) was implemented at many medical schools in the United States and other countries world wide, the debate about the merits of PBL medical education continues to embroil its proponents and those who favor the more traditional lecture‐based approach to learning. The author, while believing that the premise of PBL medical education is still valid, is disappointed that poor implementation of PBL has compromised its potential. Several reasons that may explain why PBL has failed to live up to its promises and expectations include: first, inadequate support of the curriculum from basic scientists who either do not support the concept itself or who place much greater value on research than on teaching; second, poor oversight and inadequate assessment of the PBL curriculum on the part of administrators and faculty charged with its implementation; and third, excessive reliance on insufficiently knowledgeable or motivated clinician educators to teach basic science information and principles in the latter years of the curriculum. This essay is intended to stimulate discussion and analysis of the extent to which PBL medical education has failed to deliver on its promises.
A novel, rapid, inexpensive, and highly sensitive experiment for demonstration of DNA damage in human leukocytes by single cell gel electrophoresis
Authors: Manjunatha B. R. , Manjunatha G. T. S. , Sarika Christina , Roopa Katti M. , Naik G. R.
Published: February 2007

The single cell gel electrophoresis technique (comet assay) has been adopted to demonstrate the DNA damage in human leukocytes of individuals who are habitual smokers. This technique allows the detection of single strand and double strand DNA breaks, which are indicative of the risk of cancer. The method followed is rapid, inexpensive, and a highly sensitive technique for the evaluation of DNA damage and risk assessment in smokers. This experiment should help students understand the effect of cigarette smoking.
The S‐star trial bioinformatics course: An on‐line learning success*
Authors: Lim Yun Ping , Höög Jan‐Olov , Gardner Phyllis , Ranganathan Shoba , Andersson Siv , Subbiah Subramanian , Tan Tin Wee , Hide Winston , Weiss Anthony S.
Published: February 2007

The S‐Star Trial Bioinformatics on‐line course (www.s‐star.org) is a global experiment in bioinformatics distance education. Six universities from five continents have participated in this project. One hundred and fifty students participated in the first trial course of which 96 followed through the entire course and 70 fulfilled the overall course requirements. The course was built up of 12 lectures covering different basic and advanced topics within bioinformatics. The lectures consist of streaming video and synchronized slides with follow‐up discussion forums and a final assessment. It draws on experts from diverse institutions to share their teaching expertise and resources via distance learning. A major goal of S‐Star is to provide free introductory web‐based education. Here we present the outline of the course, experiences from a global collaboration, and feedback from the first trial of the on‐line S‐Star course.
“Link rot” limits the usefulness of web‐based educational materials in biochemistry and molecular biology*
Authors: Markwell John , Brooks David W.
Published: February 2007

The differential stability of biochemistry and molecular biology Web page resources based on their domain designation is described. Many teachers have been excited by the potential enrichment of placing hyperlinks to Internet distributed educational resources within the class materials available to their students. However, there seems to be a belated realization that such hyperlinked resources are not necessarily stable and often disappear, causing frustration for both instructor and students. We recently developed three graduate‐level biochemistry and molecular biology courses for distance delivery to high school teachers that relied heavily on such Web‐based distributed resources. The 515 hyperlinked Web pages in these courses represent a set of authentic science education resources that were monitored for 24 months since their creation (August 2000). During this time, over 20% of the URLs have been victims of “link rot,” becoming nonviable, moving without automatic forwarding, or having their content changed.
Biopolymers, enzyme activity, and biotechnology in an introductory laboratory class experience*
Authors: Vullo Diana L.
Published: February 2007

This work introduces aspects of Biological Chemistry to students of non‐related careers and, in some way, tries to develop abilities that have remained unexplored up to the moment the students face this subject. This aim was successfully achieved as shown in the results obtained with the biological model of invertase activity in immobilized Saccharomyces cerevisiae. By optimizing time and temperature and understanding the hydrolysis yield, we managed to introduce sugar and biopolymer chemistry concepts.
Bringing proteomics into the lab: Proteomics lab 101
Authors: Carvalho Felicia , Gillespie Marc E.
Published: February 2007

With the increasing importance and visibility of proteomics there is a notable lack of teaching tools that can be used for “hands on” proteomic experience. Here we describe a simple lab for teaching proteomics that is based on the two‐hybrid system. Using only simple modifications of a commercial system, an experiment set is described that takes the student from the identification of potential protein:protein interactors from a large set of proteins through the classification of the disruption of these interactions in response to the presence of a neurotoxin, in this case lead. The lab uses a prokaryotic two‐hybrid system and two human neuronal cDNA libraries as the pool from which the initial interactors are drawn. The prokaryotic system provides increased transformation efficiencies, which translate into better cDNA library representation. The lab concludes with the identification of protein:protein interactions that are affected by increasing amounts of neurotoxin and the sequencing of the cDNA‐encoded genes. Students not only gain hands on proteomic experience but also then relate their sequence to an entry in one of the burgeoning sequence databases to glean information about the identified molecular target. The experiment set is flexible and could be adapted for use with any compound that affects protein complex formation.
Student use of computer‐assisted learning (CAL) and effects on learning outcomes
Authors: Zimitat Craig , McAlpine Iain
Published: February 2007

This article reports on a qualitative evaluation of student use of a computer‐assisted learning (CAL) program and associated learning outcomes. Learning outcomes were classified by analysis of examination scripts using the Structure of Observed Learning Outcomes (SOLO) taxonomy, and individuals were interviewed to uncover aspects of their learning processes while using the CAL program. All students were aware of the “design for learning” features of the CAL program, although not all students were able to take advantage of these because of their own note‐taking practices. Verbatim or excessive note‐taking was associated with surface learning outcomes, while summarizing or personal note‐taking and engagement with the program was associated with deep learning outcomes. Other factors affecting learning outcomes included students' perceptions of the role of the program, social elements of the learning environment, and a lack of distinction between major and minor issues in the content.
The role of a chaperone in protein synthesis
Authors: Szeberényi József
Published: February 2007

Terms to be familiar with before you start to solve the test: chaperones, sucrose density gradient centrifugation, SDS‐polyacrylamide gel electrophoresis, Western blotting, translation, ribosomes, polysomes.
Advanced instrumentation projects for first‐year biochemistry laboratory
Authors: Hall Mona L. , Guth Christine A. , Kohler Susan J. , Wolfson Adele J.
Published: February 2007

Our first‐semester biochemistry course is accompanied by a project‐based laboratory with a focus on the enzyme lysozyme. The first half of the semester involves purification of the enzyme. In the second half, students learn to work with advanced instrumentation techniques, specifically fluorescence spectroscopy and isothermal titration calorimetry. These methods are linked, as much as possible, to the theme of lysozyme: its structure, stability, or binding of ligand. As a final project, students design an experiment involving one of these methods. Examples are determination of the pKa of the catalytic residue and the binding affinity for an inhibitor under different conditions of pH and temperature. Four weeks of laboratory are sufficient for students to learn how to use the instruments and to develop a short project. At the end of the project, students give an oral presentation on the theory of the method and their results and prepare a paper that undergoes peer review. Hands‐on experience with these methods reinforces theoretical concepts taught in the lecture portion of the course.
Titrant standardizations: A research‐oriented laboratory practice
Authors: Günther Tânia M. F. , da Silva Fabiana C. M , Günther Arno R.
Published: February 2007

The quantitative character of biochemistry imposes some familiarization of the student with analytical practice in laboratory work and data analysis. This article describes the application of an inexpensive home‐made precision titrator for titrant standardizations, introducing the students to amino acid and protein pH titrations and data analysis.