bluuebunny/crossref_metadata_2025_split huggingface dataset:
Targeting π‐Conjugated Multiple Donor–Acceptor Motifs Exemplified by Tetrathiafulvalene‐Linked Quinoxalines and Tetrabenz[bc,ef,hi,uv]ovalenes: Synthesis, Spectroscopic, Electrochemical, and Theoretical Characterization
Authors: Jia Hong‐Peng , Ding Jie , Ran Ying‐Fen , Liu Shi‐Xia , Blum Carmen , Petkova Irina , Hauser Andreas , Decurtins Silvio 
Published: September 2011

AbstractAn efficient synthetic approach to a symmetrically functionalized tetrathiafulvalene (TTF) derivative with two diamine moieties, 2‐[5,6‐diamino‐4,7‐bis(4‐pentylphenoxy)‐1,3‐benzodithiol‐2‐ylidene]‐4,7‐bis(4‐pentylphenoxy)‐1,3‐benzodithiole‐5,6‐diamine (2), is reported. The subsequent Schiff‐base reactions of 2 afford large π‐conjugated multiple donor–acceptor (D–A) arrays, for example, the triad 2‐[4,9‐bis(4‐pentylphenoxy)‐1,3‐dithiolo[4,5‐g]quinoxalin‐2‐ylidene]‐4,9‐bis(4‐pentylphenoxy)‐1,3‐dithiolo[4,5‐g]quinoxaline (8) and the corresponding tetrabenz[bc,ef,hi,uv]ovalene‐fused pentad 1, in good yields and high purity. The novel redox‐active nanographene 1 is so far the largest known TTF‐functionalized polycyclic aromatic hydrocarbon (PAH) with a well‐resolved 1H NMR spectrum. The electrochemically highly amphoteric pentad 1 and triad 8 exhibit various electronically excited charge‐transfer states in different oxidation states, thus leading to intense optical intramolecular charge‐transfer (ICT) absorbances over a wide spectral range. The chemical and electrochemical oxidations of 1 result in an unprecedented TTF⋅+ radical cation dimerization, thereby leading to the formation of [1⋅+]2 at room temperature in solution due to the stabilizing effect, which arises from strong π–π interactions. Moreover, ICT fluorescence is observed with large solvent‐dependent Stokes shifts and quantum efficiencies of 0.05 for 1 and 0.035 for 8 in dichloromethane.
Mapping maize genes: A series of research‐based laboratory exercises
Authors: Makarevitch Irina , Kralich Elizabeth 
Published: September 2011

AbstractOpen‐ended, inquiry‐based multiweek laboratory exercises are the key elements to increasing students' understanding and retention of the major biological concepts. Including original research into undergraduate teaching laboratories has also been shown to motivate students and improve their learning. Here, we present a series of original laboratory exercises on fine mapping novel maize mutations producing interesting phenotypes. In this 4‐week lab series, students get involved in the whole process of identifying novel genes controlling specific phenotypes, from phenotype characterization and choosing appropriate molecular markers to calculating the genetic distance between the mutation and the marker and finding possible candidate genes using a complete genome sequence. We chose to use maize mutant lines produced by TILLING project. These lines have been partially mapped to a chromosomal bin by a high‐throughput bulk segregant analysis; however, the exact map positions for these mutations have never been determined. Mapping these novel maize mutations provides students with the opportunity to conduct original research as a part of their classroom experience and to contribute to the field of maize genetics. The laboratory series was well received by the students, and the assessment results demonstrated an improvement of student learning of gene mapping, molecular marker analysis, and positional cloning concepts. Biochemistry and Molecular Biology Education Vol. 39, No. 5, pp. 375–383, 2011
A participatory learning approach to biochemistry using student authored and evaluated multiple‐choice questions
Authors: Bottomley Steven , Denny Paul 
Published: September 2011

AbstractA participatory learning approach, combined with both a traditional and a competitive assessment, was used to motivate students and promote a deep approach to learning biochemistry. Students were challenged to research, author, and explain their own multiple‐choice questions (MCQs). They were also required to answer, evaluate, and discuss MCQs written by their peers. The technology used to support this activity was PeerWise—a freely available, innovative web‐based system that supports students in the creation of an annotated question repository. In this case study, we describe students' contributions to, and perceptions of, the PeerWise system for a cohort of 107 second‐year biomedical science students from three degree streams studying a core biochemistry subject. Our study suggests that the students are eager participants and produce a large repository of relevant, good quality MCQs. In addition, they rate the PeerWise system highly and use higher order thinking skills while taking an active role in their learning. We also discuss potential issues and future work using PeerWise for biomedical students. Biochemistry and Molecular Biology Education Vol. 39, No. 5, pp. 352–361, 2011
Long‐lasting neuroprotective effect of sildenafil against 3,4‐methylenedioxymethamphetamine‐ induced 5‐hydroxytryptamine deficits in the rat brain
Authors: Puerta Elena , Barros‐Miñones Lucia , Hervias Isabel , Gomez‐Rodriguez Violeta , Orejana Lourdes , Pizarro Neus , de la Torre Rafael , Jordán Joaquín , Aguirre Norberto 
Published: September 2011

AbstractSildenafil, given shortly before 3,4‐methylenedioxymethamphetamine (MDMA), affords protection against 5‐hydroxytryptamine (5‐HT) depletions caused by this amphetamine derivative by an acute preconditioning‐like mechanism. Because acute and delayed preconditionings do not share the same mechanisms, we investigated whether sildenafil would also protect the 5‐HT system of the rat if given 24 hr before MDMA. For this, MDMA (3 × 5 mg/kg i.p., every 2 hr) was administered to rats previously treated with sildenafil (8 mg/kg p.o.). One week later, 5‐HT content and 5‐HT transporter density were measured in the striatum, frontal cortex, and hippocampus of the rats. Our findings indicate that sildenafil afforded significant protection against MDMA‐induced 5‐HT deficits without altering the acute hyperthermic response to MDMA or its metabolic disposition. Sildenafil promoted ERK1/2 activation an effect that was paralleled by an increase in MnSOD expression that persisted 24 hr later. In addition, superoxide and superoxide‐derived oxidants, shown by ethidium fluorescence, increased after the last MDMA injection, an effect that was prevented by sildenafil pretreatment. Similarly, MDMA increased nitrotyrosine concentration in the hippocampus, an effect not shown by sildenafil‐pretreated rats. In conclusion, our data demonstrate that sildenafil produces a significant, long‐lasting neuroprotective effect against MDMA‐induced 5‐HT deficits. This effect is apparently mediated by an increased expression of MnSOD and a subsequent reduced susceptibility to the oxidative stress caused by MDMA. © 2011 Wiley Periodicals, Inc.
Decrease in the expression of N‐methyl‐D‐aspartate receptors in the nucleus tractus solitarii induces antinociception and increases blood pressure
Authors: Marques‐Lopes J. , Martins I. , Pinho D. , Morato M. , Wilson S.P. , Albino‐Teixeira A. , Tavares I. 
Published: September 2011

AbstractN‐methyl‐D‐aspartate receptors (NMDAR) have a role in cardiovascular control at the nucleus tractus solitarii (NTS), eliciting increases or decreases in blood pressure (BP), depending on the area injected with the agonists. In spite of the association between cardiovascular control and pain modulation, the effects of manipulating NMDAR in pain responses have never been evaluated. In this study, we decreased the expression of NMDAR in the NTS using gene transfer to target receptor subunits and evaluate long‐term effects. Seven days after the injection of lentiviral vectors containing the NR1a subunit cDNA of NMDAR, in antisense orientation, into the intermediate NTS of Wistar rats, BP was measured, and the formalin test of nociception was performed. The antisense vector induced a decrease of NR1 expression in the NTS and elicited BP rises and hypoalgesia. Antisense vectors inhibited formalin‐evoked c‐Fos expression in the spinal cord, indicating decreased nociceptive activity of spinal neurons. Using a time‐course approach, we verified that the onset of both the increases in BP and the hypoalgesia was at 4 days after vector injection into the NTS. The injection of NMDA into the NTS reversed the effects of antisense vectors in pain behavioral responses and spinal neuronal activation and decreased BP and heart rate. The present study shows that the NR1 subunit of the NMDAR at the NTS is critical in the regulation of tonic cardiovascular and nociceptive control and shows an involvement of the nucleus in the modulation of sustained pain. © 2011Wiley Periodicals, Inc.
Microtubule‐associated protein 2, an early blood marker of ischemic brain injury
Authors: Park Dongsun , Joo Seong S. , Lee Hong J. , Choi Kyung‐Chul , Kim Seung U. , Kim Yun‐Bae 
Published: September 2011

AbstractThe aim of this study was to develop a sensitive and rapid blood marker to detect ischemic brain injury, because imaging techniques have a limited capacity to identify lesions during the first crucial hours without massive tissue destruction. Rats were subjected to middle cerebral artery occlusion for various durations (0.5–3 hr), followed by reperfusion. At different time points after ischemia and/or ischemia‐reperfusion, the amounts of glial fibrillary acidic protein (GFAP) and microtubule‐associated protein 2 (MAP2) in the cerebrospinal fluid (CSF) and serum were analyzed by Western blotting. Brain infarction was observed in an ischemia‐duration‐dependent manner. GFAP was drastically increased in the CSF 24 and 48 hr after reperfusion, without change in the serum level. Serum levels of MAP2 remarkably increased as early as 0.5 hr of ischemia, much earlier than the observation of minimal tissue injury 3 hr following occlusion. The serum MAP2 level was further increased by a short period (2 hr) of reperfusion, even in 0.5‐ and 1‐hr ischemic rats, despite not observing any typical tissue injuries 24 hr after reperfusion. These results indicate that the MAP2 protein may be able to detect early neuronal injuries, because the level of this protein in the blood spikes before the appearance of visible macrolesions. Therefore, MAP2 could potentially be used as a novel early marker for the detection of a neurotoxic insult. © 2011 Wiley Periodicals, Inc.
Seasonal habitat use and selection by grizzly bears in Northern British Columbia
Authors: Milakovic Brian , Parker Katherine L. , Gustine David D. , Lay Roberta J. , Walker Andrew B. D. , Gillingham Michael P. 
Published: September 2011

AbstractWe defined patterns of habitat use and selection by female grizzly bears (Ursus arctos) in the Besa‐Prophet watershed of northern British Columbia. We fitted 13 adult females with Geographic Positioning System (GPS) radio‐collars and monitored them between 2001 and 2004. We examined patterns of habitat selection by grizzly bears relative to topographical attributes and 3 potential surrogates of food availability: land‐cover class, vegetation biomass or quality (as measured by the Normalized Difference Vegetation Index), and selection value for prey species themselves (moose [Alces alces], elk [Cervus elaphus], woodland caribou [Rangifer tarandus], Stone's sheep [Ovis dalli stonei]). Although vegetation biomass and quality, and selection values for prey were important in seasonal selection by some individual bears, land‐cover class, elevation, aspect, and vegetation diversity most influenced patterns of habitat selection across grizzly bears, which rely on availability of plant foods and encounters with ungulate prey. Grizzly bears as a group avoided conifer stands and areas of low vegetation diversity, and selected for burned land‐cover classes and high vegetation diversity across seasons. They also selected mid elevations from what was available within seasonal ranges. Quantifying relative use of different attributes helped place selection patterns within the context of the landscape. Grizzly bears used higher elevations (1,595 ± 31 m SE) in spring and lower elevations (1,436 ± 27 m) in fall; the range of average elevations used among individuals was highest (500 m) during the summer. During all seasons, grizzly bears most frequented aspects with high solar gain. Use was distributed across 10 land‐cover classes and depended on season. Management and conservation actions must maintain a diverse habitat matrix distributed across a large elevational gradient to ensure persistence of grizzly bears as levels of human access increase in the northern Rocky Mountains. © 2011 The Wildlife Society.
Efficient multiple‐collision trapdoor hash family
Authors: Aboud Sattar J. , Al Ajeeli Abid T. 
Published: September 2011

ABSTRACTIn this paper, we suggest a multiple‐collision trapdoor hash family under both integer factoring and discrete logarithm problems, and we present their security proofs. In multiple‐collision trapdoor hash family, exposing multiple collisions of similar hash functions will not disclose the private key of trapdoor hash value. In the proposed multiple‐collision trapdoor hash family, a pair of secret keys is employed for generating digital signature. Under the suggested trapdoor hash family, we present competitive online and off‐line signature schemes that can considerably enhance the efficiency of online and off‐line signature schemes. Moreover, in the proposed signature scheme, a trapdoor hash function can be employed for signing multiple documents. When a signer embraces this approach in the public‐key digital certificate, there is no need to include an ordinary digital signature scheme to sign the hash function in the off‐line part. Copyright © 2011 John Wiley & Sons, Ltd.
Analysis of the Inter- and Intra-Observer Agreement in Radiographic Evaluation of Wrist Fractures Using the Multimedia Messaging Service
Authors: Ferrero Andrea , Garavaglia Guido , Gehri Roland , Maenza Ferruccio , Petri Gianfranco John , Fusetti Cesare 
Published: September 2011

Background Orthopaedic surgeons are often asked to evaluate X-rays of patients admitted to the Accident and Emergency Department with the suspicion of a wrist fracture or, in the case of an evident fracture, to decide the correct treatment. The aim of this study was to evaluate the feasibility of a correct interpretation of the images of injured wrists on the screen of a last generation mobile phone, in order to evaluate if the specialist could make the right diagnosis and choose the correct treatment. Methods Five orthopaedic and one hand surgeons have evaluate the X-rays of 67 patients who sustained an injury to their wrist. In the case of fracture, they were asked to classify it according to the AO and Mayo classification systems. The evaluation of the images was accomplished through the PACS and using a mobile phone, at a different time. In order to check the inter- and intra-observer reliability, the same pattern was followed after a few months. Results The mobile phone showed basically the same agreement between the observers highlighting the worsening of the inter- and intra-observer reliability with the increment of the variables considered by a classification system. Conclusions The present paper confirms that a last generation mobile phone can already be used in the clinical practise of orthopaedic surgeons on call who could use it as a useful device in remote or poorly served areas for a rapid and economic consultation Level of Evidence The level of evidence of this case is economic and decision analysis, level 2
Frontal instabilities and waves in a differentially rotating fluid
Authors: Flór J.-B. , Scolan H. , Gula J. 
Published: September 2011

AbstractWe present an experimental investigation of the stability of a baroclinic front in a rotating two-layer salt-stratified fluid. A front is generated by the spin-up of a differentially rotating lid at the fluid surface. In the parameter space set by rotational Froude number, $F$, dissipation number, $d$ (i.e. the ratio between disk rotation time and Ekman spin-down time) and flow Rossby number, a new instability is observed that occurs for Burger numbers larger than the critical Burger number for baroclinic instability. This instability has a much smaller wavelength than the baroclinic instability, and saturates at a relatively small amplitude. The experimental results for the instability regime and the phase speed show overall a reasonable agreement with the numerical results of Gula, Zeitlin & Plougonven (J. Fluid Mech., vol. 638, 2009, pp. 27–47), suggesting that this instability is the Rossby–Kelvin instability that is due to the resonance between Rossby and Kelvin waves. Comparison with the results of Williams, Haines & Read (J. Fluid Mech., vol. 528, 2005, pp. 1–22) and Hart (Geophys. Fluid Dyn., vol. 3, 1972, pp. 181–209) for immiscible fluid layers in a small experimental configuration shows continuity in stability regimes in $(F, d)$ space, but the baroclinic instability occurs at a higher Burger number than predicted according to linear theory. Small-scale perturbations are observed in almost all regimes, either locally or globally. Their non-zero phase speed with respect to the mean flow, cusped-shaped appearance in the density field and the high values of the Richardson number for the observed wavelengths suggest that these perturbations are in many cases due to Hölmböe instability.
Digital Divide and Social Cleavage: Case Studies of ICT Usage among Peasants in Contemporary China
Authors: Guo Yuhua , Chen Peng 
Published: September 2011

AbstractDuring its structural transformation, rural China witnessed the emergence of four types of village: traditional, industrialized, commercial and villages in cities. Information Communication Technologies (ICTs), including fixed phones, cell phones, television sets and the internet (with personal computers), are now commonly used in Chinese villages but in ways that differentiate villagers according to variables such as occupation, villager membership and social status. The adoption of ICTs by peasants not only represents but also accelerates growing peasant differentiation; in other words, the function of ICTs could not penetrate the barrier of social structure. Meanwhile, structural transformation in China has been an activator to shaping peasants' diversified ideas about information, and the demand for and usage of ICTs. An analysis of peasants' ICT adoption thus enables us to identify the basic trends and characteristics of social transformation in contemporary China.
Mg2+ as an indicator of nutritional status in marine bacteria
Authors: Heldal Mikal , Norland Svein , Erichsen Egil Severin , Sandaa Ruth-Anne , Larsen Aud , Thingstad Frede , Bratbak Gunnar 
Published: September 2011

Abstract
Cells maintain an osmotic pressure essential for growth and division, using organic compatible solutes and inorganic ions. Mg2+, which is the most abundant divalent cation in living cells, has not been considered an osmotically important solute. Here we show that under carbon limitation or dormancy native marine bacterial communities have a high cellular concentration of Mg2+ (370–940 mm) and a low cellular concentration of Na+ (50–170 mm). With input of organic carbon, the average cellular concentration of Mg2+ decreased 6–12-fold, whereas that of Na+ increased ca 3–4-fold. The concentration of chlorine, which was in the range of 330–1200 mm, and was the only inorganic counterion of quantitative significance, balanced and followed changes in the concentration of Mg2++Na+. In an osmotically stable environment, like seawater, any major shift in bacterial osmolyte composition should be related to shifts in growth conditions, and replacing organic compatible solutes with inorganic solutes is presumably a favorable strategy when growing in carbon-limited condition. A high concentration of Mg2+ in cells may also serve to protect and stabilize macromolecules during periods of non-growth and dormancy. Our results suggest that Mg2+ has a major role as osmolyte in marine bacteria, and that the [Mg2+]/[Na+] ratio is related to its physiological condition and nutritional status. Bacterial degradation is a main sink for dissolved organic carbon in the ocean, and understanding the mechanisms limiting bacterial activity is therefore essential for understanding the oceanic C-cycle. The [Mg2+]/[Na+]-ratio in cells may provide a physiological proxy for the transitions between C-limited and mineral nutrient-limited bacterial growth in the ocean's surface layer.
Cytoskeletal rearrangements in human red blood cells induced by snake venoms: light microscopy of shapes and NMR studies of membrane function
Authors: Yau Tsz Wai , Kuchel Rhiannon P. , Koh Jennifer M. S. , Szekely David , Mirtschin Peter J. , Kuchel Philip W. 
Published: September 2011

AbstractRBCs (red blood cells) circulating through narrow blood capillaries withstand major deformation. The mechanical and chemical stresses commonly exerted on RBCs continue to attract interest for the study of membrane structure and function. Snake venoms are lethal biochemical ‘cocktails’ that often contain haemotoxins, metalloproteinases, myotoxins, neurotoxins, phosphodiesterases, phospholipases and proteases. We have monitored the effects of 4 snake venoms (Pseudechis guttatus, Oxyuranus scutellatus, Notechis scutatus and Naja kaouthia) on human RBCs using NMR spectroscopy, DIC (differential interference contrast) and confocal light microscopy. RBCs underwent reproducible stomatocytosis, with unusual geographical‐like indentations, spherocytosis, followed by rapid lysis. Confocal micrographs using a fluorescent dye linked to phalloidin showed that the change in morphology was associated with the aggregation of actin in the cytoskeleton. 31P NMR saturation transfer experiments recorded transport of the univalent anion HPA (hypophosphite) on a subsecond time scale, thereby reporting on the function of capnophorin or Band 3 linked to the cytoskeleton; anion‐exchange activity was substantially reduced by venom treatment. We propose a molecular‐cytological hypothesis for the shape and functional changes that is different from, or supplementary to, the more ‘traditional’ bilayer‐couple hypothesis more often used to account for similar morphological changes invoked by other reagents.
Women's Employment Issues in Contemporary Iran: Problems and Prospects in the 1990s
Authors: Moghadam Valentine M. 
Published: September 2011

Patterns of Women's Employment in Iran have been Influenced BY the oil-based nature of the economy; by the policy of import-substitution industrialization which has favored capital-intensive, male-intensive industries; by cultural attitudes and gender bias which render many occupations inappropriate or off-limits to women; by women's low level of literacy, educational attainment, and skills relative to men; and by high rates of fertility. These factors have affected, and indeed limited, the supply of and demand for female labor, especially in the 1980s.The results of the 1986 census, which came to light in 1988, seem to have prompted a number of significant policy shifts on the part of the government of President Rafsanjani and sparked debates, studies, and research projects concerning population issues, women's economic and social roles, and development strategies.