bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fight or flight: antipredator strategies of baleen whales
Authors: FORD JOHN K. B. , REEVES RANDALL R. 
Published: March 2008

ABSTRACTThe significance of killer whaleOrcinus orcapredation on baleen whales (Mysticeti) has been a topic of considerable discussion and debate in recent years. Discourse has been constrained by poor understanding of predator‐prey dynamics, including the relative vulnerability of different mysticete species and age classes to killer whales and how these prey animals avoid predation. Here we provide an overview and analysis of predatory interactions between killer whales and mysticetes, with an emphasis on patterns of antipredator responses.Responses of baleen whales to predatory advances and attacks by killer whales appear to fall into two distinct categories, which we term thefightandflightstrategies. Thefightstrategy consists of active physical defence, including self‐defence by single individuals, defence of calves by their mothers and coordinated defence by groups of whales. It is documented for five mysticetes: southern right whaleEubalaena australis, North Atlantic right whaleEubalaena glacialis, bowhead whaleBalaena mysticetus, humpback whaleMegaptera novaeangliaeand grey whaleEschrichtius robustus. Theflightstrategy consists of rapid (20–40 km/h) directional swimming away from killer whales and, if overtaken and attacked, individuals do little to defend themselves. This strategy is documented for six species in the genusBalaenoptera.Many aspects of the life history, behaviour and morphology of mysticetes are consistent with their antipredator strategy, and we propose that evolution of these traits has been shaped by selection for reduced predation.Fightspecies tend to have robust body shapes and are slow but relatively manoeuvrable swimmers. They often calve or migrate in coastal areas where proximity to shallow water provides refuge and an advantage in defence. Mostfightspecies have either callosities (rough and hardened patches of skin) or encrustations of barnacles on their bodies, which may serve (either primarily or secondarily) as weapons or armour for defence.Flightspecies have streamlined body shapes for high‐speed swimming and they can sustain speeds necessary to outrun pursuing killer whales (>15–20 km/h). These species tend to favour pelagic habitats and calving grounds where prolonged escape sprints from killer whales are possible.The rarity of observed successful attacks by killer whales on baleen whales, especially adults, may be an indication of the effectiveness of these antipredator strategies. Baleen whales likely offer low profitability to killer whales, relative to some other marine mammal prey. High‐speed pursuit offlightspecies has a high energetic cost and a low probability of success while attacks onfightspecies can involve prolonged handling times and a risk of serious injury.
Anthropogenic causes of the western Steller sea lion Eumetopias jubatus population decline and their threat to recovery
Authors: ATKINSON SHANNON , DEMASTER DOUGLAS P. , CALKINS DONALD G. 
Published: March 2008

ABSTRACT

The western Steller sea lion Eumetopias jubatus population has experienced a chronic decline since the 1960s. The causes are likely multifactorial and a combination of anthropogenic and natural factors. A draft revised recovery plan for the Steller sea lion has been published by the US National Marine Fisheries Service, listing both anthropogenic and natural factors that may have contributed to the observed decline or which may be a threat to the recovery of the western Steller sea lion population. The purpose of this review is to consider the anthropogenic threats to this stock.
Anthropogenic sources of mortality include fisheries competition resulting in nutritional stress, mortality incidental to commercial fisheries (i.e. fisheries by‐catch), subsistence hunts, legal and illegal shooting, commercial hunts, anthropogenic‐related contamination, and research‐induced mortalities.
We present evidence that the following anthropogenic factors likely contributed to the decline of the western Steller sea lion population over the last 40 years: (i) mortality incidental to commercial fisheries (i.e. by‐catch); (ii) commercial hunting of western Steller sea lions; and (iii) legal and illegal shooting; whereas the subsistence hunts for western Steller sea lions and mortality incidental to research were not likely to be contributors to the observed decline.
Further, we present evidence that the following can be excluded as significant anthropogenic threats to the recovery of the western Steller sea lion population: (i) mortality incidental to commercial fishing; (ii) legal and illegal shooting; (iii) commercial hunts of Steller sea lions; (iv) subsistence hunting; and (v) mortality incidental to research.
Competition with fisheries resulting in nutritional stress, and the potential impacts of contaminants, are two anthropogenic factors that should continue to be a priority for the various organizations currently doing research on this population.
A widespread riboswitch candidate that controls bacterial genes involved in molybdenum cofactor and tungsten cofactor metabolism
Authors: Regulski Elizabeth E. , Moy Ryan H. , Weinberg Zasha , Barrick Jeffrey E. , Yao Zizhen , Ruzzo Walter L. , Breaker Ronald R. 
Published: March 2008

SummaryWe have identified a highly conserved RNA motif located upstream of genes encoding molybdate transporters, molybdenum cofactor (Moco) biosynthesis enzymes, and proteins that utilize Moco as a coenzyme. Bioinformatics searches have identified 176 representatives in γ‐Proteobacteria, δ‐Proteobacteria, Clostridia, Actinobacteria, Deinococcus‐Thermus species and DNAs from environmental samples. Using genetic assays, we demonstrate that a Moco RNA in Escherichia coli associated with the Moco biosynthetic operon controls gene expression in response to Moco production. In addition, we provide evidence indicating that this conserved RNA discriminates against closely related analogues of Moco. These results, together with extensive phylogenetic conservation and typical gene control structures near some examples, indicate that representatives of this structured RNA represent a novel class of riboswitches that sense Moco. Furthermore, we identify variants of this RNA that are likely to be triggered by the related tungsten cofactor (Tuco), which carries tungsten in place of molybdenum as the metal constituent.
Hysteretic and graded responses in bacterial two‐component signal transduction
Authors: Igoshin Oleg A. , Alves Rui , Savageau Michael A. 
Published: March 2008

SummaryBacterial two‐component systems (TCS) are key signal transduction networks regulating global responses to environmental change. Environmental signals may modulate the phosphorylation state of sensor kinases (SK). The phosphorylated SK transfers the phosphate to its cognate response regulator (RR), which causes physiological response to the signal. Frequently, the SK is bifunctional and, when unphosphorylated, it is also capable of dephosphorylating the RR. The phosphatase activity may also be modulated by environmental signals. Using the EnvZ/OmpR system as an example, we constructed mathematical models to examine the steady‐state and kinetic properties of the network. Mathematical modelling reveals that the TCS can show bistable behaviour for a given range of parameter values if unphosphorylated SK and RR form a dead‐end complex that prevents SK autophosphorylation. Additionally, for bistability to exist the major dephosphorylation flux of the RR must not depend on the unphosphorylated SK. Structural modelling and published affinity studies suggest that the unphosphorylated SK EnvZ and the RR OmpR form a dead‐end complex. However, bistability is not possible because the dephosphorylation of OmpR∼P is mainly done by unphosphorylated EnvZ. The implications of this potential bistability in the design of the EnvZ/OmpR network and other TCS are discussed.
Ferritin is required for rapid remodeling of the photosynthetic apparatus and minimizes photo‐oxidative stress in response to iron availability in Chlamydomonas reinhardtii
Authors: Busch Andreas , Rimbauld Blandine , Naumann Bianca , Rensch Stefan , Hippler Michael 
Published: March 2008

SummaryFerritin is a key player in the iron homeostasis due to its ability to store large quantities of iron. Chlamydomonas reinhardtii contains two nuclear genes for ferritin (ferr1 and ferr2) that are induced when Chlamydomonas cells are shifted to iron‐deficient conditions. In response to the reduced iron availability, degradation of photosystem I (PSI) and remodeling of its light‐harvesting complex occur. This active PSI degradation slows down under photo‐autotrophic conditions where photosynthesis is indispensable. We observed a strong induction of ferritin correlated with the degree of PSI degradation during iron deficiency. The PSI level can be restored to normal within 24 h after iron repletion at the expense of the accumulated ferritin, indicating that the ferritin‐stored iron allows fast adjustment of the photosynthetic apparatus with respect to iron availability. RNAi strains that are significantly reduced in the amount of ferritin show a striking delay in the degradation of PSI under iron deficiency. Furthermore, these strains are more susceptible to photo‐oxidative stress under high‐light conditions. We conclude that (i) ferritin is used to buffer the iron released by degradation of the photosynthetic complexes, (ii) the physiological status of the cell determines the strategy used to overcome the impact of iron deficiency, (iii) the availability of ferritin is important for rapid degradation of PSI under iron deficiency, and (iv) ferritin plays a protective role under photo‐oxidative stress conditions.
Structural analysis and haplotype diversity in swine LEP and MC4R genes
Authors: D'Andrea M. , Pilla F. , Giuffra E. , Waddington D. , Archibald A.L. 
Published: March 2008

SummaryKnowledge about structural variation of candidate genes could be important to improve breeding selection scheme and preserve genetic variability in livestock species. Leptin (LEP) and melanocortin‐4 receptor (MC4R) genes are involved in the energetic pathway and are obvious candidate genes for fatness. By sequencing LEP and MC4R genes in 72 pigs belonging to lean (Large White and Duroc), fat (Meishan and Casertana) breeds and also Wild Boar, 98 polymorphic sites, of which 91 were novel, were found in the Leptin sequence while only the previously described mutation was found in the MC4R gene. A total of 18 LEP haplotypes were observed and their distribution was unequal among the breeds. The phylogenetic analysis showed two haplotype branches distinguishing between lean and fat breeds.
Effect of parental genotypes and paternal heterosis on litter traits in crossbred goats
Authors: Tsukahara Y. , Choumei Y. , Oishi K. , Kumagai H. , Kahi A.K. , Panandam J.M. , Mukherjee T.K. , Hirooka H. 
Published: March 2008

SummaryThe effect of parental genotype and paternal heterosis on litter size (LS), total litter birth weight (TLW) and average litter birth weight (ALW) was analysed utilizing data from a crossbreeding programme involving the exotic German Fawn goats and local Katjang goats in Malaysia. In this study, these traits were regarded as traits of the litter to consider the effect of service sire genotype. The results revealed that LS was significantly influenced by the genotype of sire. The genotypes of sire and dam had significant effects on TLW and ALW. Estimates of crossbreeding parameter showed significant and negative influence of paternal heterosis on TLW and ALW while there was no significant effect of paternal heterosis on LS. The results of this study stress the need to reconsider the use of local males in the tropics.
Association analysis of the constructed linkage maps covering TLR2 and TLR4 with clinical mastitis in Norwegian Red cattle
Authors: Opsal M.A. , Lien S. , Brenna‐Hansen S. , Olsen H.G. , Våge D.I. 
Published: March 2008

SummaryToll‐like receptors (TLR) are important cell‐surface molecules mediating immune responses. Previous studies have identified TLR2 and TLR4 as potential candidate genes for disease resistance. In this study, dense linkage maps comprising single nucleotide polymorphisms (SNPs) have been constructed for the chromosomal regions harbouring TLR2 and TLR4 on bovine chromosome 17 and 8. The most likely marker orders for both regions were compared with the corresponding human map positions and used to reorder bovine scaffolds available from the bovine genome sequence assembly (Btau_3.1). A combined linkage and linkage disequilibrium method was used to investigate possible associations between the TLR genes and mastitis susceptibility recorded in the Norwegian Red cattle population. The analysis did not detect any significant association between the chromosomal regions surrounding TLR2 and TLR4 and mastitis in Norwegian Red cattle.
In vivo confocal microscopy in a patient with conjunctival amyloidosis
Authors: Bozkurt Banu , Kiratli Hayyam , Soylemezoglu Figen , Irkec Murat 
Published: March 2008

AbstractConjunctival amyloidosis is a rare clinical entity. We herein reported in vivo confocal microscopic features of conjunctival amyloidosis and correlated the results with the histopathological findings. Histopathological examination of the biopsy specimen revealed acellular, amorphous, eosinophilic material in the substantia propria of the conjunctiva and positive staining with Congo red confirmed that the material was amyloid. Confocal microscopy with Heidelberg Retina Tomograph II Rostock Cornea Module showed hyporeflective material deposited in a lobular pattern in the substantia propria and around the blood vessels. The material seemed acellular and no inflammatory or dendriform cell accumulation was noted within or around the lesion. Further studies should be done to understand the confocal characteristics of the conjunctival diseases and find specific clues for the diagnosis.
The one‐eye trial and fellow eye response to prostaglandin analogues
Authors: Dayanir Volkan , Cakmak Harun , Berkit Ilker 
Published: March 2008

AbstractBackground:  To determine if the intraocular pressure (IOP) reduction in one‐eye trial correlates with the IOP reduction in the fellow eye when IOP variability during office hours is taken into account.Methods:  This retrospective observational case series includes 50 high tension (primary open‐angle glaucoma, exfoliative glaucoma and ocular hypertension; Group 1) and 21 normal tension (Group 2) glaucoma patients. Charts of bilateral open‐angle glaucoma patients at Glaucoma Unit, School of Medicine, Adnan Menderes University who had pretreatment baseline office IOP measurements at 9:30, 11:30 and 15:30; were put on a one‐eye trial with prostaglandin analogues, and then subsequently received the same medication in the fellow eye were reviewed. Pretreatment baseline office IOP measurements and reductions in the first and second eyes were compared to determine variability and correlation, respectively.Results:  Both groups showed significant variability in pretreatment baseline office IOP measurements. Peak IOP level was before noon in at least 70% of eyes in Group 1, 50% in Group 2. IOP dropped a mean of 8.8 ± 4.8 mmHg (34%, P = < 0.0001) in Group 1 and 4.9 ± 2.4 mmHg (30%, P = < 0.0001) in Group 2 during the one‐eye trial. Following bilateral use of the medication a mean drop of 7.5 ± 4.0 mmHg (31%, P = < 0.0001) in Group 1 and 2.9 ± 1.9 mmHg (18%, P = < 0.0001) in Group 2 were obtained. The IOP reduction between fellow‐eye pairs were significantly correlated in Group 1 (r = 0.541, P = < 0.0001) but not Group 2 (r =−0.310, P = 0.171).Conclusions:  One‐eye trial is a feasible method to determine the effectiveness of prostaglandin analogues and to predict the amount of IOP reduction in the fellow eye in patients with high tension glaucoma.
Documentation of corneal epithelial defects with fluorescein‐enhanced digital fundus camera photography
Authors: Dean Simon J , Novitskaya Elena S , Moore Tara CB , Moore Johnny E , Sharma Anant 
Published: March 2008

AbstractThe advent of digital photography in the ophthalmic setting has provided not only a means of documenting pathology, but with instantaneous results, it is possible to aid clinical diagnosis and management. This study was designed to demonstrate the ability to image corneal epithelial lesions stained with fluorescein, with a digital fundus camera set on fluorescein angiography settings. The contrast of this technique demonstrated both gross and subtle corneal epithelial lesions better than traditional methods. The results obtained demonstrated the high sensitivity and high contrast images this technique can facilitate in every ophthalmic practice equipped with a fundus camera with digital fluorescein angiography capability.
Joint capsule treatment with enkephalin‐encoding HSV‐1 recombinant vector reduces inflammatory damage and behavioural sequelae in rat CFA monoarthritis
Authors: Lu Ying , McNearney Terry A. , Wilson Steven. P. , Yeomans David C. , Westlund Karin N. 
Published: March 2008

AbstractThis study assessed enkephalin expression induced by intra‐articular application of recombinant, enkephalin‐encoding herpes virus (HSV‐1) and the impact of expression on nociceptive behaviours and synovial lining inflammation in arthritic rats. Replication‐conditional HSV‐1 recombinant vectors with cDNA encoding preproenkephalin (HSV‐ENK), or control transgene β‐galactosidase cDNA (HSV‐β‐gal; control) were injected into knee joints with complete Freund's adjuvant (CFA). Joint temperatures, circumferences and nociceptive behaviours were monitored on days 0, 7, 14 and 21 post CFA and vector treatments. Lumbar (L4–6) dorsal root ganglia (DRG) and spinal cords were immunostained for met‐enkephalin (met‐ENK), β‐gal, HSV‐1 proteins and Fos. Joint tissues were immunostained for met‐ENK, HSV‐1 proteins, and inflammatory mediators Regulated on Activation, Normal T‐cell Expressed and Secreted (RANTES) and cyclo‐oxygenase‐2, or stained with haematoxylin and eosin for histopathology. Compared to exuberant synovial hypertrophy and inflammatory cell infiltration seen in arthritic rats treated with CFA only or CFA and HSV‐β‐gal, the CFA‐ and HSV‐ENK‐treated arthritic rats had: (i) striking preservation of synovial membrane cytoarchitecture with minimal inflammatory cell infiltrates; (ii) significantly improved nociceptive behavioural responses to mechanical and thermal stimuli; (iii) normalized Fos staining in lumbar dorsal horn; and (iv) significantly increased met‐ENK staining in ipsilateral synovial tissue, lumbar DRG and spinal cord. The HSV‐1 and transgene product expression were confined to ipsilateral lumbar DRG (HSV‐1, met‐ENK, β‐gal). Only transgene product (met‐ENK and β‐gal) was seen in lumbar spinal cord sections. Targeted delivery of enkephalin‐encoding HSV‐1 vector generated safe, sustained opioid‐induced analgesia with protective anti‐inflammatory blunting in rat inflammatory arthritis.
Auditory Scene Analysis: the interaction of stimulation rate and frequency separation on pre‐attentive grouping
Authors: De Sanctis Pierfilippo , Ritter Walter , Molholm Sophie , Kelly Simon P. , Foxe John J. 
Published: March 2008

AbstractSegregation of auditory inputs into meaningful acoustic groups is a key element of auditory scene analysis. Previously, we showed that two interwoven sets of tones differing widely along multiple feature dimensions (duration, pitch and location) were pre‐attentively separated into different groups, and that tones separated in this manner did not elicit the mismatch negativity component with respect to each other. Grouping was studied with human subjects using a stimulus rate too slow to induce streaming. Here, we varied the separation of tone sequences along a single feature dimension, i.e. frequency. Frequency differences were either 24 Hz (small) or 1054 Hz (large). Two relatively slow stimulus rates were used (2.7 or 1 tone/s) to explicitly investigate grouping outside the so‐called ‘streaming effect’, which requires rates of about 4 tones/s or faster. Two tones were presented in a quasi‐random manner with embedded trains of one to four identical tones in a row. Deviants were defined as frequency switches after trains of four identical tones. Mismatch negativity was only elicited for small frequency switches at the slower stimulation rate. The data indicate that pre‐attentive grouping of tones occurred when the frequency difference that separated them was large, regardless of stimulation rate. For small frequency differences, inputs were only grouped separately when the stimulation rate was relatively fast.
Cytoplasmic calcium mediates oxidative damage in an excitotoxic /energetic deficit synergic model in rats
Authors: Pérez‐De La Cruz Verónica , Konigsberg Mina , Pedraza‐Chaverri José , Herrera‐Mundo Nieves , Díaz‐Muñoz Mauricio , Morán Julio , Fortoul‐van der Goes Teresa , Rondán‐Zárate Adrián , Maldonado Perla D. , Ali Syed F. , Santamaría Abel 
Published: March 2008

AbstractExcessive calcium is responsible for triggering different potentially fatal metabolic pathways during neurodegeneration. In this study, we evaluated the role of calcium on the oxidative damage produced in an in vitro combined model of excitotoxicity/energy deficit produced by the co‐administration of quinolinate and 3‐nitropropionate to brain synaptosomal membranes. Synaptosomal fractions were incubated in the presence of subtoxic concentrations of these agents (21 and 166 µm, respectively). In order further to characterize possible toxic mechanisms involved in oxidative damage in this experimental paradigm, agents with different properties – dizocilpine, acetyl l‐carnitine, iron porphyrinate and S‐allylcysteine – were tested at increasing concentrations (10–1000 µm). Lipid peroxidation was assessed by the formation of thiobarbituric acid‐reactive substances. For confirmatory purposes, additional fractions were incubated in parallel in the presence of the intracellular calcium chelator 1,2‐bis(2‐aminophenoxy)ethane‐N,N,N′,N′‐tetraacetic acid‐acetoxymethyl ester (BAPTA‐AM). Under physiological conditions of extracellular calcium availability, synaptomes exposed to both toxins displayed an increased lipoperoxidation (76% above controls), and this effect was partially attenuated by the tested agents as follows: dizocilpine = iron porphyrinate > acetyl l‐carnitine > S‐allylcysteine. When the incubation medium was deprived of calcium, the lipoperoxidative effect achieved in this experimental paradigm was still high (49% above the control), and the order of attenuation was: iron porphyrinate > S‐allylcysteine > acetyl l‐carnitine > dizocilpine. BAPTA‐AM was effective in preventing the pro‐oxidant action of both toxins, promoting even lower peroxidative levels than those quantified under basal conditions. Our results suggest that the lipid peroxidation induced in synaptosomal fractions by quinolinate plus 3‐nitropropionate is largely dependent on the cytoplasmic concentrations of calcium.