bluuebunny/crossref_metadata_2025_split huggingface dataset:
Habitat use and social structure of a brown lemur hybrid population in the Berenty Reserve, Madagascar
Authors: Tanaka Mikiko 
Published: February 2007

AbstractThe 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

AbstractField 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

Abstract1918 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.
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

AbstractThe 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

AbstractThe 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

AbstractSynthesis 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

AbstractAs 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

AbstractBACKGROUND: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

AbstractMolecular 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

AbstractIn 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

AbstractIn 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

AbstractDiagrams 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

AbstractTerms 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

AbstractMetabolic 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

AbstractEnzymes 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

AbstractThis 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

AbstractThis 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.
The free energy of denaturation of lysozyme: An undergraduate experiment in biophysical chemistry*
Authors: Kurtin William E. , Lee John M. 
Published: February 2007

AbstractAn 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

AbstractThis 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

AbstractThis 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

AbstractThe 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

AbstractThis 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.